Introduction {#sec1}
============

Leber\'s hereditary optic neuropathy (LHON), a maternally inherited disease characterized by bilateral central vision loss, remains without cure.[@bib1], [@bib2], [@bib3], [@bib4] Recent in vitro studies have highlighted estrogen\'s role in preserving vision by increasing mitochondrial biogenesis.[@bib5], [@bib6] However, estrogen\'s protective role in vivo has yet to be reported.

We report a case of LHON in a menopausal woman, who experienced accelerated visual recovery following treatment with idebenone and hormone replacement therapy (HRT).

Case report {#sec2}
===========

A 48-year-old woman presented with a four-month history of painless, progressive loss of vision beginning with the left eye followed by subsequent involvement of the right eye two months later. The patient was previously treated with intravenous (IV) corticosteroids for presumed optic neuritis, however, her vision worsened. Best corrected visual acuities (BCVA) were 20/60 OD and 20/200 OS. Intraocular pressures were 13 OU. Color vision on Ishihara plate testing was 1/14 OD and 0/14 OS. Humphrey visual field (HVF) testing showed bilateral cecocentral scotomas ([Fig. 1](#fig1){ref-type="fig"}); dilated funduscopy revealed temporal pallor OU. Neurological examination of motor and sensory function, muscle bulk, tone, and gait were intact. Magnetic resonance imaging (MRI) showed a normal optic nerve appearance bilaterally without enhancement or periventricular white matter lesions. Lumbar puncture cerebrospinal fluid analysis, autoimmune panel, immunoglobulins, and complement levels were all negative. The patient\'s mother had bilateral vision loss at 58 years of age. Of note, the patient consumed more than a half-bottle of wine daily. She was previously on contraceptive hormonal therapy including etonogestrel 0.12 mg and ethinyl estradiol 0.015 mg daily. Her visual symptoms began three months after discontinuing the hormonal regimen. The patient\'s presentation was concerning for mitochondrial optic neuropathy. She began idebenone 300 mg TID with vitamin C, resumed her original hormonal regimen of etonogestrel 0.12 mg and ethinyl estradiol 0.015 mg daily and minimized alcohol consumption. Genetic testing of the patient and her mother for OPA1 and LHON mitochondrial DNA (mtDNA) mutations (11778G \> A, 14484T \> C and 3460G \> A) was negative. Intriguingly, the patient\'s vision markedly improved post-therapy, having BCVAs of 20/40 OD and 20/60 OS by one month; 20/25 OU by two months; 20/20 OD and 20/25 OS by eight months. Color vision significantly improved on Ishihara plate testing, scoring 2/14 OD and 1/14 OS by one month; 6/14 OD and 2/14 OS by six months. 30-2 HVF also markedly improved OU by two months ([Fig. 2](#fig2){ref-type="fig"}) and continued to eight months ([Fig. 3](#fig3){ref-type="fig"}). Comprehensive mitochondrial genome sequencing genetically confirmed LHON, revealing a 10197 mtDNA mutation.Fig. 1(A, B) Humphrey visual field (HVF) 24-2 maps of the visual field examination on initial presentation, revealing significant cecocentral scotomas in the left and right eye, respectively. (C, D) Depict total deviation of the visual field examination on initial presentation in the left and right eye, respectively. Mean deviation: --15.66 dB OS, --18.25 dB OD.Fig. 2(A, B) Humphrey visual field (HVF) 30-2 maps of the visual field examination at two months, revealing mild decrease in cecocentral scotomas in the left and right eye, respectively. (C, D) depict total deviation of the visual field examination on initial presentation in the left and right eye, respectively. Mean deviation: −8.11 dB OD, −13.14 dB OS.Fig. 2Fig. 3(A, B) Humphrey visual field (HVF) 30-2 maps of the visual field examination at eight months, revealing further decrease of the scotomas in the left and right eye, respectively. (C, D) depict less total deviation of the visual field examination on second visit in the left and right eye, respectively. Mean deviation: −4.56 dB OD, −6.61 dB OS.Fig. 3

Discussion {#sec3}
==========

We present a case of LHON in a menopausal woman whose vision loss began shortly after discontinuing estrogen replacement. While causality cannot be definitively proven, the patient\'s presentation in association with estrogen deficiency and the absence of alternative triggers is highly suggestive of estrogen\'s protective role in LHON. Also, LHON 10197, characterized by an ND3 subunit defect in mitochondrial complex I, has been solely identified in patients with Leigh syndrome, Leigh-like syndrome, and LHON and dystonia.[@bib7], [@bib8] Our case provides the first reporting of this mutation with isolated LHON, as the patient had no accompanying neurological deficits.

Idebenone can absorb reactive oxygen species and serve as an electron carrier in the mitochondrial respiratory chain. Visual improvement typically does not occur until two or more years post-therapy, and rarely occurs by one year.[@bib9], [@bib10] Our patient\'s vision improved shortly after one month with complete visual recovery by eight months. Therefore additional mechanisms must be considered. Recent studies have highlighted the important role of estrogen in preserving vision in LHON. This may explain not only the reduced prevalence of disease in women relative to men overall, but also the increased incidence of disease associated with a decline in estrogen as frequently seen in menopausal patients.[@bib5], [@bib6] In vitro studies have elucidated estrogen\'s mechanism of action. Through activation of the estrogen β receptor, which localizes to the mitochondrial network of retinal ganglion cells, estrogen upregulates antioxidant enzyme production of superoxide dismutase 2, increases mitochondrial biogenesis, and enhances cellular energy competence.[@bib5], [@bib6] Idebenone treatment combined with HRT may have a synergistic effect in enhancing cellular bioenergetics and may explain the patient\'s accelerated visual improvement. Nevertheless, additional studies are needed to confirm estrogen\'s protective role in vivo.

Conflicts of interest: The authors declare that there is no conflict of interest regarding the publication of this paper.

Peer review under responsibility of the Iranian Society of Ophthalmology.


#!/usr/bin/python
import numpy
from sys import argv
from keras.models import Sequential
from keras.layers import Dense
from keras.layers import Dropout
from keras.layers import LSTM
from keras.callbacks import ModelCheckpoint
from keras.utils import np_utils
#added this so i can fiddel around with the model from one place
SEQ_LEN = 12
class PasswordLSTM:
	def __init__(self,X,y):
		#pull some configs
		self.SEQ_LEN = SEQ_LEN
		self.X = X
		self.y = y
		self.input_shape = (X.shape[1],X.shape[2])
		self.filepath="seq-%d-weights-improvement-{epoch:02d}-{loss:.4f}.hdf5" % (self.SEQ_LEN)
		self.epochs = 50
		self.batch_size = 50
		self.monitor = 'loss'
		self.verbose = 1
		self.save_best_only=True
		self.mode='min'
		self.checkpoint = None
		self.model = Sequential()
		self.model_built = False

	def build_model(self):
		self.model = Sequential()
		self.model.add(LSTM(512,input_shape=self.input_shape,return_sequences=True))
		self.model.add(Dropout(0.2))
		self.model.add(LSTM(512))
		self.model.add(Dropout(0.2))

		self.model.add(Dense(self.y.shape[1],activation='softmax'))
		self.model.compile(loss='categorical_crossentropy',optimizer='adam')
		self.model_built = True
	def predict(self,x,verbose):
		return self.model.predict(x,verbose=verbose)
	def load_weights(self,filename):
		if (self.model_built != True):
			self.build_model()
		self.model.load_weights(filename)
	def fit(self):
		print "[*] training model..."
		self.checkpoint = ModelCheckpoint(filepath=self.filepath,monitor=self.monitor,verbose=self.verbose,save_best_only=self.save_best_only,mode=self.mode)
		self.model.fit(self.X,self.y,epochs=self.epochs,batch_size=self.batch_size,callbacks=[self.checkpoint])


---
abstract: 'Sr$_{2}$Cr$_{3}$As$_{2}$O$_{2}$ is composed of alternating square-lattice CrO$_2$ and Cr$_2$As$_2$ stacking layers, where CrO$_2$ is isostructural to the CuO$_2$ building-block of cuprate high-$T_c$ superconductors and Cr$_2$As$_2$ to Fe$_2$As$_2$ of Fe-based superconductors. Current interest in this material is raised by theoretic prediction of possible superconductivity. In this neutron powder diffraction study, we discovered that magnetic moments of Cr(II) ions in the Cr$_2$As$_2$ sublattice develop a C-type antiferromagnetic structure below 590 K, and the moments of Cr(I) in the CrO$_2$ sublattice form the La$_2$CuO$_4$-like antiferromagnetic order below 291 K. The staggered magnetic moment $2.19(4) \mu_{B}$/Cr(II) in the more itinerant Cr$_2$As$_2$ layer is smaller than $3.10(6) \mu_{B}$/Cr(I) in the more localized CrO$_2$ layer. Different from previous expectation, a spin-flop transition of the Cr(II) magnetic order observed at 291 K indicates a strong coupling between the CrO$_2$ and Cr$_2$As$_2$ magnetic subsystems.'
author:
- Juanjuan Liu
- Jinchen Wang
- Jieming Sheng
- Feng Ye
- 'Keith M. Taddei'
- 'J. A. Fernandez-Baca'
- Wei Luo
- 'Guang-Ai Sun'
- 'Zhi-Cheng Wang'
- Hao Jiang
- 'Guang-Han Cao'
- Wei Bao
title: 'Neutron diffraction study on magnetic structures and transitions in Sr$_{2}$Cr$_{3}$As$_{2}$O$_{2}$'
---

[^1]

[^2]

INTRODUCTION
============

It is well known that the square-lattice CuO$_2$ layer is the essential building block of cuprate superconductors [@Bednorz1986]. The antiferromagnetic order in the CuO$_2$ layer is suppressed by charge doping which gives rise to high-temperature superconductivity [@Lee2006]. For the more recently discovered iron pnictide superconductors, the common structural ingredient is the Fe$_2$As$_2$ layer [@LaOFeAs.2008], and the interplay between antiferromagnetism in the layer and superconductivity has attracted intense research interest [@rev2009H; @rev2010l; @rev2011t; @CPB2013]. The fact that unconventional superconductivity with high transition temperature ($T_c$) tends to occur in materials containing the CuO$_2$ or Fe$_2$As$_2$ structural ingredient has inspired investigation on materials of the same structural building blocks. New type of unconventional superconductivity was discovered in Sr$_2$RuO$_4$ [@214RMP] and the stripe physics, a correlated charge and antiferromagnetic order phenomenon, was uncovered in Sr$_2$NiO$_4$ [@Ni214_Sr2], when Cu in the cuprate Sr$_2$CuO$_4$ was replaced by Ru or Ni. Superconductivity has also been discovered in doped CoO$_2$ layered compounds [@H2OSC]. Similarly, isostructural materials of the iron pnictide superconductors have also been the focus of recent research. It has been proposed in theoretic studies that superconductivity could be induced by electron doping LaCrAsO [@PhysRevB.95.144507.2017; @PhysRevB.95.075115] and BaCr$_{2}$As$_{2}$ [@PhysRevB.95.205118], similar to the ‘1111’ and ‘122’-type Fe-based superconductors [@LaOFeAs.2008; @A054630]. Experimental studies have been carried out so far on the parent compounds LaCrAsO [@LnCrAsO.2013], BaCr$_{2}$As$_{2}$ [@PhysRevB.79.094429.2009], SrCr$_{2}$As$_{2}$ [@PhysRevB.96.014411.2017] and EuCr$_{2}$As$_{2}$ [@PhysRevB.94.094411.2016], and these materials are found to be metallic, and to develop a G-type antiferromagnetic order with the Néel temperature as high as 600 K.

An interesting family of oxipnictides $A_2$Mn$_3Pn_2$O$_2$ ($A$ = Sr, Ba and $Pn$ = P, As, Sb, Bi) [@Brechtel1979; @Stetson1991; @Brock1994; @Brock1996; @Brock_magstr1996; @Ozawa1998; @Matsushita20001424; @Ozawa2001; @PhysRevB.81.224513.2010; @Eguchi2013] is formed of alternating CuO$_2$-type and Fe$_2$As$_2$-type layers, containing the key structural ingredients of both the cuprate and Fe-based superconductors. The two different types of Mn square lattices of MnO$_2$ and Mn$_2$As$_2$ stacking along the $c$ axis with the tetragonal space group $I4/mmm$ (No. 139). The isostructural ‘2322’ oxysulfides also exist [@Zhu1997; @ZHU1997319; @Otzschi1999; @Gal2006; @Smura2011; @Jin2012]. Although $A_2$Mn$_3Pn_2$O$_2$ are antiferromagnetic insulators, it was suggested in theoretic works that superconductivity can be realized in the ‘2322’ family with a proper choice of the transition metal to substitute Mn [@Volkova2008; @Ozawa2008; @XDai2016]. Motivated by the theoretic suggestion, the chromium based ‘2322’ material Sr$_{2}$Cr$_{3}$As$_{2}$O$_{2}$ was recently synthesized [@PhysRevB.92.205107.2015], containing alternating CrO$_2$ and Cr$_2$As$_2$ layers along the $c$ axis, see Fig. \[str\] (a). The electrical resistivity shows metallic response [@PhysRevB.92.205107.2015], as in the recently investigated ‘1111’ and ‘122’-type chromium pnictides [@LnCrAsO.2013; @PhysRevB.79.094429.2009; @PhysRevB.96.014411.2017; @PhysRevB.94.094411.2016].

In $A_2$Mn$_3Pn_2$O$_2$, the Mn$_2$Pn$_2$ layer tends to form a G-type antiferromagnetic order around 300 K [@Brock_magstr1996]. The magnetic couplings in the MnO$_2$ layer are significantly weaker. While the MnO$_2$ layer in Sr$_2$Mn$_3$Sb$_2$O$_2$ forms long-range magnetic order at 65 K [@Brock_magstr1996], it shows only short-range magnetic order with a spin freezing behavior below $\sim$50 K in compounds such as Sr$_2$Mn$_3$As$_2$O$_2$ [@Brock_magstr1996], Sr$_2$Zn$_2$As$_2$MnO$_2$ [@Ozawa2001] and Ba$_2$Zn$_2$As$_2$MnO$_2$ [@PhysRevB.81.224513.2010].

For Sr$_{2}$Cr$_{3}$As$_{2}$O$_{2}$, anomalies in electric resistivity, magnetic susceptibility and heat capacity were observed below the room temperature, indicating magnetic transitions in line with the prediction of magnetically ordered ground state in both the CrO$_2$ and Cr$_2$As$_2$ layers from first principle calculation [@PhysRevB.92.205107.2015]. However, the nature of magnetic transitions at the bulk measurement anomalies remains unclear. Therefore we have conducted a neutron powder diffraction study on Sr$_{2}$Cr$_{3}$As$_{2}$O$_{2}$ to investigate magnetic structures in the two Cr sublattices and the corresponding phase transitions.

We found that the magnetic moments of the Cr(II) ions in the Cr$_2$As$_2$ sublattice develop a C-type antiferromagnetic order at a temperature as high as 590 K with the $c$-axis as the magnetic easy axis, see Fig. \[str\] (c). The in-plane magnetic arrangement of Sr$_{2}$Cr$_{3}$As$_{2}$O$_{2}$ is the same as in the G-type antiferromagnetic order of the ‘1111’ and ‘122’-type chromium pnictides [@LnCrAsO.2013; @PhysRevB.79.094429.2009; @PhysRevB.96.014411.2017; @PhysRevB.94.094411.2016], however, the inter-plane Cr(II) ions are ferromagnetically aligned in contrast to the case in the G-type order in those chromium pnictides. Below 291 K, the Cr(I) ions in the CrO$_2$ sublattice forms a K$_2$NiF$_4$-type [@PhysRevB.1.2211] long-range antiferromagnetic order with moments along the $c$ direction, see Fig. \[str\] (b). This is the same antiferromagnetic order discovered in the cuprate La$_2$CuO$_4$ [@la3dv]. When the Cr(I) sublattice orders at 291 K, a spin-flop transition occurs on the Cr(II) sublattice with the moment direction flips from the $c$ axis to the $ab$ plane. The observed magnetic structure is different from the prediction from the first-principle calculations [@PhysRevB.92.205107.2015].

EXPERIMENTAL METHODS
====================

The polycrystalline sample of Sr$_{2}$Cr$_{3}$As$_{2}$O$_{2}$ was grown by solid-state reactions using SrO (99.5%), Cr (99.9%) and As (99.999%) as starting materials [@PhysRevB.92.205107.2015]. The sample was initially examined using the high-resolution neutron powder diffractometer at the Key Laboratory of Neutron Physics, China Academy of Engineering Physics (CAEP). Neutron powder diffraction measurements were carried out on the HB-2A neutron powder diffractometer [@HB2Ainstrument] at the High Flux Isotope Reactor (HFIR), Oak Ridge National Laboratory (ORNL). On HB-2A, neutron wavelength of $\lambda = 2.4101 \AA$ and $1.5392 \AA$ were selected by the vertically focused Ge(113) and Ge(115) monochromator, respectively. The beam was collimated by the 21$'$ Soller collimator before sample and 12$'$ before detectors. Approximate 5.74 g powder sample was sealed in a cylindrical Al container with Helium as exchange gas to ensure thermal equilibrium. It was loaded into a closed cycle refrigerator that regulates the temperature from 4 K to 300 K. High temperature neutron data were taken on the HB-1A triple-axis spectrometer at HFIR with fixed incident neutron energy 14.64 meV (wavelength $ 2.364 \AA$) produced by the double pyrolytic graphite monochromator system. The temperature was regulated by high temperature Displex from 30 K to 700 K.

Besides main phase of Sr$_{2}$Cr$_{3}$As$_{2}$O$_{2}$ and minor impurity phase, notable Al Bragg peaks from the sample environment were detected. Using FullProf Suite package [@RODRIGUEZCARVAJAL199355], the nuclear and magnetic structures of the main phase were refined using the Rietveld method [@Rietveld1969] while Al peaks are accounted by Le Bail fitting [@LeBail1988]. The Thompson-Cox-Hastings pseudo-Voigt function corrected by axial divergence asymmetry was used to model the peak profiles of all phases. Due to the existence of Al and impurity peaks, the refinements of thermal factors against individual atoms give unreliable results, so the overall thermal factor for all atoms is used at each temperature. BasIreps program of FullProf Suite is used for representation analysis to derive the possible magnetic structure modes.

Results and Discussions
=======================

![(color online) (a) Crystal structure of Sr$_{2}$Cr$_{3}$As$_{2}$O$_{2}$. The atoms are noted by different colors. Layers of CrO$_{2}$ squares and Cr$_{2}$As$_{2}$ tetrahedra are labeled. (b) The magnetic structure below 291 K when both CrO$_{2}$ layer and Cr$_{2}$As$_{2}$ layer order. (c) The magnetic structure above 291 K when only the Cr$_{2}$As$_{2}$ layer orders. The solid lines in (b) and (c) are the structural unit cell identical to the cell in (a), and the dash lines in (b) are the magnetic unit cell with $ \boldsymbol{a}_{mag} = \boldsymbol{a} + \boldsymbol{b} $, $ \boldsymbol{b}_{mag} = \boldsymbol{a} - \boldsymbol{b} $. []{data-label="str"}](Fig1.eps){width="\columnwidth"}

The neutron powder diffraction pattern measured at room temperature is shown in Fig. \[rf300K\]. At 300 K, two wavelengths were used, as the shorter wavelength of neutron probes the structure in a larger reciprocal-space range. The refined parameters under different conditions are summarized in Table \[str\_tb\] and two wavelengths give essentially no different results. Consistent with earlier reports [@PhysRevB.92.205107.2015], Sr$_{2}$Cr$_{3}$As$_{2}$O$_{2}$ crystallizes in the tetragonal space group $I4/mmm $ (No. 139). The Cr(I) in the CrO$_{2}$ layer resides at the Wyckoff $2a$ site, forms body centered sublattice. The Cr(II) in the Cr$_{2}$As$_{2}$ layer resides at the Wyckoff $4d$ site, forms primitive sublattice.

Both the As-M-As bond angle (M denotes transition metal) and the As height are important parameters controlling the electronic states driven by the $p-d$ hybridization and exchange interactions. In the iron-based superconductors, the As-Fe-As bond angle and the anion height were found in close relation to superconducting transition temperatures $T_c$. To achieve optimal $T_c$, it was suggested to have regular FeAs$_4$ tetragonal with the As-Fe-As bond angle close to 109.47[@FeAsangle1111; @qiu2008] or anion height close to 1.38 Å[@mizuguchi2010]. Here, the As-Cr(II)-As bond angle of Sr$_{2}$Cr$_{3}$As$_{2}$O$_{2}$ is around 105.8and 111.3, and the As height is around 1.51 $\AA$, with little temperature dependence from 300 K to 4 K as seen from Table \[str\_tb\].

![(color online) The neutron diffraction pattern of Sr$_{2}$Cr$_{3}$As$_{2}$O$_{2}$ at room temperature, with wavelength $\lambda = 2.4101 \AA{}$. The observation, calculation and their difference are denoted in red circles, green and blue lines, respectively. The vertical bars in green, red and black mark the nuclear Bragg peaks positions of Sr$_{2}$Cr$_{3}$As$_{2}$O$_{2}$, Al and magnetic Bragg peaks positions from the Cr(II) sublattice. The impurity peaks are marked with stars and are excluded during refinement. The inset (a) zooms in expected positions of magnetic peaks of wave-vector $(\frac{1}{2},\frac{1}{2},0)$ and inset (b) magnetic peaks of wave-vector $(1,0,0)$. []{data-label="rf300K"}](Fig2.eps){width="\columnwidth"}

  ------------------------------------- ------------ ------------ ------------ ------------ ------------ ------------ ------------
                  T (K)                     300          300          260          230          200          100           4
             wavelength (Å)                1.5392       2.4101       2.4101       2.4101       2.4101       2.4101       2.4101
                 $a$ (Å)                 4.00671(6)   4.00574(5)   4.00417(6)   4.00306(6)   4.00198(6)   3.99941(6)   3.99892(6)
                 $c$ (Å)                 18.8310(5)   18.8261(5)   18.8029(5)   18.7862(5)   18.7717(5)   18.7303(5)   18.7151(5)
             $V$ (Å$ ^{3} $)             302.31(1)    302.08(1)    301.47(1)    301.04(1)    300.64(1)    299.60(1)    299.28(1)
              $z_\text{Sr}$              0.4125(2)    0.4117(2)    0.4120(2)    0.4128(2)    0.4123(2)    0.4115(2)    0.4113(2)
              $z_\text{As}$              0.8298(2)    0.8308(2)    0.8305(2)    0.8304(2)    0.8304(2)    0.8309(2)    0.8308(2)
              B (Å$ ^{2} $)               0.77(2)      0.60(4)      0.47(4)      0.42(4)      0.34(4)      0.30(4)      0.18(4)
              As height (Å)               1.503(3)     1.521(4)     1.514(4)     1.510(4)     1.510(4)     1.515(4)     1.512(4)
   As-Cr(II)-As angle (deg) $\times 2$   106.23(6)    105.57(7)    105.82(7)    105.92(7)    105.95(7)    105.69(7)    105.80(7)
   As-Cr(II)-As angle (deg) $\times 4$    111.1(1)     111.5(2)     111.3(2)     111.3(2)     111.3(2)     111.4(2)     111.3(2)
      $m$ $(\mu_{B}/\text{Cr(II)})$       1.97(4)      1.97(3)      2.02(4)      2.11(4)      2.12(4)      2.18(4)      2.19(4)
      $m$ $(\mu_{B}/\text{Cr(I)})$           0            0         2.46(7)      2.69(7)      2.78(6)      3.07(6)      3.10(6)
              R$ _{p}$ (%)                  4.01         3.94         4.04         4.36         4.07         4.24         4.48
              R$ _{wp}$ (%)                 5.43         5.55         6.04         6.48         6.44         6.33         6.53
  ------------------------------------- ------------ ------------ ------------ ------------ ------------ ------------ ------------

Three peaks indexed as (1,0,0), (1,0,2) and (1,0,4) that are forbidden by the crystal symmetry were observed at 300 K, as presented in the inset (b) of Fig. \[rf300K\]. These intensities are accounted by the C-type magnetic structure of the Cr(II) spins in the Cr$_2$As$_2$ layer shown in Fig. \[str\] (c). It is antiferromagnetically (AFM) arranged for intra-layer nearest neighbor spins but ferromagnetically (FM) arranged for inter-layer spins, resulting in wave-vector (1,0,0). The moment direction is along the $c$ axis, and the moment size is $1.97(4) \mu_{B}/\text{Cr(II)}$ at 300 K. The magnetic structure persists up as high as $590.3(7)$ K, as demonstrated by the temperature dependence of (1,0,0) peak in Fig. \[op\] (a).

The high ordering temperature and the intra-layer AFM pattern established in the Cr$_2$As$_2$ layer of Sr$_{2}$Cr$_{3}$As$_{2}$O$_{2}$ resemble those in other chromium pnictides. In ‘1111’-type LaCrAsO [@LnCrAsO.2013], and the ‘122’-type BaCr$_{2}$As$_{2}$, SrCr$_{2}$As$_{2}$ and EuCr$_{2}$As$_{2} \cite{PhysRevB.79.094429.2009,PhysRevB.96.014411.2017,PhysRevB.94.094411.2016}$, the same intra-layer spin arrangement and ordering temperature around 600 K were found. This reveals a robust AFM intra-layer coupling which does not change across compositions. However, in Sr$_{2}$Cr$_{3}$As$_{2}$O$_{2}$ the inter-layer coupling becomes FM, in contrast to the ‘1111’ and ‘122’ chromium pnictides which have AFM inter-layer couplings in the G-type magnetic structure.

![(color online) (a) Temperature dependence of the integrated intensity of the magnetic Bragg peak (1,0,0). The solid line and onset temperature of $T_N = 590.3(7)$ K was obtained by fitting to the order parameter function $I/I_0 = (1-\frac{T}{T_N})^{2\beta} + b_0$. (b) Temperature dependence the background corrected peak intensity of the Bragg peaks (1,0,0) and $(\frac{1}{2}, -\frac{1}{2}, 1)$. The solid lines are guide to eyes. The insets are the peaks profiles for (1,0,0) and $(\frac{1}{2}, -\frac{1}{2}, 1)$ at selected temperatures.[]{data-label="op"}](Fig3.eps){width=".9\columnwidth"}

Below 291 K, new peaks appear that can be indexed by the wave-vector $\boldsymbol{k}' = (\frac{1}{2}, \frac{1}{2}, 0)$. Meanwhile, the $\boldsymbol{k}'' = (1,0,0)$ series of peaks change their intensity. This is demonstrated in Fig. \[op\] (b) by abrupt changes of magnetic peaks intensities on (1,0,0) and $(\frac{1}{2}, -\frac{1}{2}, 1)$ around 291 K. As we will demonstrate, the arise of $(\frac{1}{2}, \frac{1}{2}, 0)$ series of peaks corresponds to the magnetic order established on the Cr(I) sublattice in the CrO$_2$ layer, and the intensity change on $(1,0,0)$ series of peaks corresponds to a sudden flip of Cr(II) moment in the Cr$_2$As$_2$ layer. The transition is responsible for the susceptibility anomaly observed around 291 K[@PhysRevB.92.205107.2015]. The first-order-like transitions in both the $(\frac{1}{2}, \frac{1}{2}, 0)$ and $(1,0,0)$ type magnetic Bragg peaks (Fig. \[op\] (b)) suggest strong interaction between the Cr(I) and Cr(II) ions.

![(color online) The observed and calculated neutron diffraction pattern of Sr$_{2}$Cr$_{3}$As$_{2}$O$_{2}$ at $T = 4$ K, with wavelength $\lambda = 2.4101 \AA{}$. The observation, calculation and their difference are denoted in red circles, green and blue lines, respectively. The vertical bars in green and red mark the nuclear Bragg peaks positions of Sr$_{2}$Cr$_{3}$As$_{2}$O$_{2}$ and Al, respectively. The vertical bars in blue and black mark the magnetic Bragg peaks positions from the Cr(I) and Cr(II) sublattice, respectively. The impurity peaks are marked with stars and are excluded during refinement. The inset (a) zooms in magnetic peaks of wave-vector $(\frac{1}{2},\frac{1}{2},0)$ and inset (b) magnetic peaks of wave-vector $(1,0,0)$. []{data-label="rf4K"}](Fig4.eps){width="\columnwidth"}

Magnetic Bragg peaks below 291 K are fitted by the magnetic structure depicted in Fig. \[str\] (b), with the Cr(I) and Cr(II) moment sizes the only two refined parameters. The magnetic order on the Cr(I) site of the CrO$_2$ layer is responsible for the $(\frac{1}{2}, \frac{1}{2}, 0)$ wave-vector. The nearest neighbors of intra-layer Cr(I) spins are AFM aligned, and the moments point to $c$ axis. The magnetic structure of the body centered Cr(I) sublattice mimics that of the body centered K$_2$NiF$_4$ [@PhysRevB.1.2211]. Interestingly, when the Cr(I) sublattice orders, the moments at the Cr(II) site in the Cr$_2$As$_2$ layer flip into the $ab$ plane. The magnetic structure where two sublattices have orthogonal spin orientations persists down to 4 K, the base temperature in our measurement. The diffraction pattern together with the fits at 4 K are presented in Fig. \[rf4K\]. In principle, the specific in-plane moment direction of tetragonal structure cannot be resolved from powder diffraction data due to the powder-averaged intensity [@Shirane1959]. We therefore don’t distinguish the in-plane moment direction of Cr(II), and the Cr(II) moment direction in Fig. \[str\] (b) is plotted for illustration purpose. The refined moments on the Cr(I) and Cr(II) sublattices at each temperatures are summarized in Table \[str\_tb\]. From 300 K to 260 K, a quick increase of Cr(I) moment size is witnessed when the order is established. This is then followed by a slower increase rate and gradual saturation down to the base temperature. For the Cr(II) moments, despite an abrupt change of the direction, the ordered moment of Cr(II) shows very small change below 300 K.

[m[2cm]{}<\*[4]{}[m[3.8cm]{}<]{}]{} &\
& $ \Gamma'_{3} $ & $ \Gamma'_{5} $ & $ \Gamma'_{7} $ &\
BV for site     (0,0,0) & $(0, 0, m_z)$ & $(m_x, m_x, 0)$ & $(m_x, -m_x, 0)$ &\
magnetic structure & [![image](Cr1-gamma3.eps){width="22mm"}]{} & [![image](Cr1-gamma5.eps){width="22mm"}]{} & [![image](Cr1-gamma7.eps){width="22mm"}]{} &\
&\
& $ \Gamma''_{2} $ & $ \Gamma''_{5} $ & $ \Gamma''_{9} $ & $ \Gamma''_{10} $\
BV for site   (0,0.5,0.25) & $(0, 0, m_z)$ & $(0, 0, m_z)$ & $(m_x, 0, 0)$ $(0, m_y, 0)$ & $(m_x, 0, 0)$ $(0, m_y, 0)$\
BV for site   (0,0.5,0.75) & $(0, 0, -m_z)$ & $(0, 0, m_z)$ & $(-m_x, 0, 0)$ $(0, -m_y, 0)$ & $(m_x, 0, 0)$ $(0, m_y, 0)$\
magnetic structure mode & [![image](Cr2-gamma2.eps){width="15mm"}]{} & [![image](Cr2-gamma5.eps){width="15mm"}]{} & [![image](Cr2-gamma9.eps){width="15mm"}]{} & [![image](Cr2-gamma10.eps){width="15mm"}]{}\

The magnetic structures above and below 291 K are further confirmed by the representation analysis [@Bertaut.a05871]. The space group for the crystal structure is $I4/mmm$. For wave-vector $\boldsymbol{k}' = (\frac{1}{2}, \frac{1}{2}, 0)$, the little group $mmm$ that leaves the wave-vector unchanged has eight one-dimensional irreducible representations (IR) $\Gamma'_{1} \dots \Gamma'_{8}$. The linear spaces spanned by spin vectors on site Cr(I) and Cr(II) are three dimensional and six dimensional, respectively. Therefore, they can be decomposed to three and six one-dimensional IRs of group $mmm$ $$\begin{aligned}
    \Gamma'_{\text{Cr(I)}} = 1\Gamma'_{3} + 1\Gamma'_{5} + 1\Gamma'_{7},\end{aligned}$$ and $$\begin{aligned}
    \Gamma'_{\text{Cr(II)}} =  1\Gamma'_{1} +  1\Gamma'_{2} + 1\Gamma'_{3} + 1\Gamma'_{4} + 1\Gamma'_{7} + 1\Gamma'_{8}.\end{aligned}$$ Only the magnetic structure of $\Gamma'_{3}$ for Cr(I) spins fits the magnetic Bragg peaks of $(\frac{1}{2}, \frac{1}{2}, 0)$ series. For wave-vector $\boldsymbol{k}'' = (1, 0, 0)$, the little group is the same as the crystal point group $4/mmm$. It has eight one-dimensional IRs $\Gamma''_{1} \dots \Gamma''_{8}$ and two two-dimensional IRs $\Gamma''_{9}$ and $\Gamma''_{10}$. The spin spaces on site Cr(I) and Cr(II) can be decomposed as $$\begin{aligned}
    \Gamma''_{\text{Cr(I)}} = 1\Gamma''_{7} + 1\Gamma''_{10},\end{aligned}$$ and $$\begin{aligned}
    \Gamma''_{\text{Cr(II)}} =  1\Gamma''_{2} +  1\Gamma''_{5} + 1\Gamma''_{9} + 1\Gamma''_{10}.\end{aligned}$$ The magnetic Bragg peaks of $(1, 0, 0)$ series above 291 K comes from the $\Gamma''_{5}$ of Cr(II) spins, and below 291 K the $\Gamma''_{10}$ of Cr(II) spins. The three decomposed IRs of Cr(I) spins with wave-vector $(\frac{1}{2}, \frac{1}{2}, 0)$ and four IRs of Cr(II) spins with wave-vector $(1, 0, 0)$ are illustrated in Table \[irrep\_tb\].

The magnetic structure of Sr$_{2}$Cr$_{3}$As$_{2}$O$_{2}$ make interesting comparison to other ‘2322’ compounds such as the manganese analog $A_2$Mn$_3Pn_2$O$_2$ and chromium pnictides LaCrAsO and BaCr$_{2}$As$_{2}$. In $A_2$Mn$_3Pn_2$O$_2$ and chromium pnictides, the magnetic moments in the Mn$_2$As$_2$ and Cr$_2$As$_2$ sublattices form AFM arrangement both within and between layers with the wave-vector (1,0,1) in the so-called G-type magnetic structure [@Brock_magstr1996; @PhysRevB.81.224513.2010; @LnCrAsO.2013; @PhysRevB.95.184414]. In Sr$_{2}$Cr$_{3}$As$_{2}$O$_{2}$, however, the inter-layer spin arrangement is FM and the magnetic structure becomes a C-type with the magnetic wave-vector (1,0,0). The magnetic CrO$_2$ buffer layer between the Cr$_2$As$_2$ layers might be responsible for the change of the coupling sign. The ordering temperatures for the Mn$_2$As$_2$ sublattice in $A_2$Mn$_3Pn_2$O$_2$ are around 300 K. But for the Cr$_2$As$_2$ sublattice in chromium pnictides and Sr$_{2}$Cr$_{3}$As$_{2}$O$_{2}$, the ordering temperatures are close to 600 K, indicating much stronger interaction strength in the Cr$_2$As$_2$ sublattice than the Mn$_2$As$_2$ sublattice.

The MnO$_2$ layers in Sr$_2$Mn$_3$Sb$_2$O$_2$, Sr$_2$Mn$_3$As$_2$O$_2$ and Ba$_2$Zn$_2$MnAs$_2$O$_2$ establish magnetic order with wave-vector $(\frac{1}{2}, \frac{1}{2}, 0)$ [@Brock_magstr1996; @Ozawa2001; @PhysRevB.81.224513.2010], the same as the CrO$_2$ layer in Sr$_{2}$Cr$_{3}$As$_{2}$O$_{2}$. However, only in Sr$_2$Mn$_3$Sb$_2$O$_2$ the magnetic order is long-ranged and at a much reduced temperature of 65 K. In Sr$_2$Mn$_3$As$_2$O$_2$, Sr$_2$Zn$_2$MnAs$_2$O$_2$ and Ba$_2$Zn$_2$MnAs$_2$O$_2$, the magnetic order is short-ranged with a spin freezing behavior. These contrast to the long-range order at 291 K for the CrO$_2$ layer spins in Sr$_{2}$Cr$_{3}$As$_{2}$O$_{2}$. Again the magnetic interactions in the CrO$_2$ sublattice of Sr$_{2}$Cr$_{3}$As$_{2}$O$_{2}$ are much stronger than in the MnO$_2$ sublattice in $A_2$Mn$_3Pn_2$O$_2$.

The moments in the Cr$_2$As$_2$ layer are along the $c$ direction above 291 K, consistent with the orientation in the ‘1111’ and ‘122’ chromium pnictides. This reflects the same easy axis due to the single-ion anisotropy of Cr$^{2+}$ in the Cr$_2$As$_2$ environment. However, the magnetic ordering of the Cr(I) ions along the $c$ direction in the CrO$_2$ sublattice flips the Cr(II) ions in the Cr$_2$As$_2$ sublattice into the $ab$ plane, changing the easy axis in the Cr$_2$As$_2$ layer. The magnetic structure where two sublattices have orthogonal moment directions was also observed in Sr$_2$Mn$_3$Sb$_2$O$_2$ [@Brock_magstr1996], although in a reverse way: the moments in the Mn$_2$As$_2$ layer order along the $c$ direction, and in the MnO$_2$ layer in the $ab$ plane. It was believed previously that in the ‘2322’ compounds the two sublattices show independent magnetic behaviors and the interaction between the two sublattices was negligible [@Brock_magstr1996]. The abrupt spin-flop transition found in our work on Sr$_{2}$Cr$_{3}$As$_{2}$O$_{2}$ (Fig. \[op\] (b)) provides evidence that the two magnetic sublattices are closely correlated. The magnetic state of orthogonal moment directions in the two sublattices was not reproduced through simple bilayer classical spin model with experimentally achievable interactions strengths [@Enjalran2000]. The nature of interaction and origin for the orthogonal spin orientation thus deserve more investigations.

While $A_2$Mn$_3Pn_2$O$_2$ are insulators, Sr$_{2}$Cr$_{3}$As$_{2}$O$_{2}$ and other chromium pnictides are metallic. We noticed that the conduction electrons are mostly from the Cr$_2$As$_2$ layer, while electrons of the CrO$_2$ layer are largely localized in the first principle calculations[@PhysRevB.92.205107.2015]. The saturation moment is $2.2 \mu_{B}$ per Cr(II) in the Cr$_2$As$_2$ layer and $3.1 \mu_{B}$ per Cr(I) in the CrO$_2$ layer. There is a larger reduction of the saturated moment in the itinerant Cr$_2$As$_2$ layer than in the localized Cr$_2$As$_2$ layer from the $4 \mu_{B}$ per Cr$^{2+}$ ion in the $3d^4$ high spin state. Therefore, it is tempted to state that the Cr$_2$As$_2$ layer contributes itinerant moments and the CrO$_2$ layer local moments, although it could be more complex due to correlations and interplay of itinerant and local electrons from two sublattices.

Conclusion
==========

We have performed neutron powder diffraction experiments from 4 to 620 K to investigate magnetic structures and magnetic transitions in Sr$_{2}$Cr$_{3}$As$_{2}$O$_{2}$. We discovered successive magnetic transitions in the material. The Cr(II) ions in the Cr$_2$As$_2$ sublattice develop a C-type antiferromagnetic order of the magnetic wave-vector $(1,0,0)$ at 590.3(7) K with the magnetic easy axis along the $c$ direction. Below 291 K, a K$_2$NiF$_4$-like antiferromagnetic order of the Cr(I) ions occurs with the magnetic wave-vector $(\frac{1}{2}, \frac{1}{2}, 0)$ in the CrO$_2$ sublattice with the easy $c$-axis. At the same transition at 291 K, magnetic moments of the Cr(II) ions in the Cr$_2$As$_2$ sublattice flip into the $ab$ plane. The magnetic structure of orthogonal moment orientation in the two sublattices persists down to 4 K. The interplay between the two magnetic sublattices may play an important role in facilitating the spin-flop transition of Cr(II) moments.

The work at RUC was supported by the National Basic Research Program of China (Grant No. 2012CB921700), the National Natural Science Foundation of China (Grant No. 11190024) and the Key Laboratory of Neutron Physics, CAEP (Grant No. 2017CB01). J. L. and J. W. acknowledges support from the Research Funds of RUC (Grant No. 17XNLF04 and 17XNLF06). J. S. acknowledges support from China Scholarship Council. The work at ZU was supported by the National Key Research and Development Program of China (No. 2017YFA0303002). Research at Oak Ridge National Laboratory was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy.

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[^1]: These authors contributed equally to this work.

[^2]: These authors contributed equally to this work.


The Horse Sense Blog compares the nonsense in today's news with good ol' fashioned horse sense

“…I shall speak forth my sentiments freely and without reserve.… It is only in this way that we can hope to arrive at truth, and fulfill the great responsibility which we hold to God and our country.Should I keep back my opinions at such a time, through fear of giving offense, I should consider myself as guilty of treason towards my country, and of an act of disloyalty toward the Majesty of Heaven, which I revere above all earthly kings.” - Patrick Henry, March 23, 1775

"The further a society drifts from truth the more it will hate those who speak it." - George Orwell

(c) copyright 2011-2016 Doug Johnson All Rights Reserved. All site content is copyright protected and subject to penalties for infringement of copyright laws.

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Monday, September 7, 2015

10 Things Carly Needs To Explain Before Voters Decide Whether To Support Her

Here's the Nonsense: Carly Fiorina has been really impressive on the campaign trail. I think she'd be a great president.Here's the Horse Sense: Yes, she's sounded good and impressed many of us, but now we need to get her to explain some things so we can determine if she's worthy of support. Anything less is irresponsible on our part as voters.

Many of us have been impressed with Carly Fiorina's performance in interviews and in the first presidential debate. She doesn't hesitate with answers, sounds strong on many issues, stands her ground, and, probably more than anything, is attracting the attention of voters because she's from the outside. Voters are not looking for someone to do business as usual in Washington. They are fed up and want change. After decades of promise after promise by the GOP, voters are ready to tear down the system and are most attracted to outsiders with no ties to or love for politics as usual. But is Carly a candidate voters should get behind? Do we really know much about her? Or is she another example of the stupidity of voters falling for someone because they say or do something to attract attention and immediately voters think that's enough to qualify them for the biggest job on the planet?In looking for more information about her, I came up with an inexhaustive list of 10 things Carly needs to explain before voters decide whether to support her candidacy. If you do your own research you may come up with even more questions. A little research raises some concerns, but you can't judge somebody based solely on their past. The fact is that people do change and if we aren't willing to allow them to do so, then we are the fools. Ronald Reagan was once a Democrat, but he changed. That doesn't mean that everyone who claims to have changed really has, but we should seek answers as to why they've changed and if their answers are satisfactory, then we should accept them. So, let's take a look at some things Carly needs to explain (in no particular order) before voters could decide whether to suppor her.

1.) Ann Coulter has gone from liking Carly to hating her as a candidate. The Washington Examiner has reported that any love Ann Coulter had for Carly is long gone. Coulter has been upset with Fiorina for standing against repealing birthright citizenship. Yahoo reported that she said, “It would take passing a constitutional amendment to get that changed. It’s part of our 14th Amendment. So honestly, I think we should put all of our energies, all of our political will into finally getting the border secured and fixing the legal immigration.” NBC also reported her saying she didn't support deportation, amending the Constitution or challenging the 14th Amendment.This raises a question regarding Carly's lack of understanding of the Constitution. She needs to answer this: Since the 14th Amendment says nothing about birthright citizenship, why are you so convinced you need a constitutional amendment to stop giving citizenship to someone just because they happen to be on American soil when the child is born? Her comment about deportation is not uncommon among candidates. We are a nation of laws and if we ignore them we are no better than the current people in power in Washington who ignore the laws they don't like. She needs to answer why she doesn't support deportation and have a better answer than telling us it's too expensive. The average illegal household that is deported saves American taxpayers over $700,000. It wouldn't cost anywhere near that to deport them.2.) Newsbusters reported that she supported Senators Marco Rubio, Dick Durbin, Charles Schumer, John McCain, Michael Bennet, Jeff Flake, Lindsey Graham, and Bob Menendez's Gang of 8 bill that included amnesty and said, "I applaud and salute the Gang of Eight's proposal. Let's move forward and vote on that."Her support for the Gang of 8 bill raises significant concern. The question Carly needs to answer is why she supported it and does she still feel the same way. And, if she's changed her position, then what caused her to change it and why.3.) Fox News reported that Carly supported TARP and said it wasn't enough. This was the disaster at the end of the Bush administration that sent America spiraling into recession. In defending it George W. Bush made the stupid statement, "I've abandoned free market principles to save the free market system."Any person with even a modest understanding of our economy knows that TARP was a disaster from which we've still not recovered (And yes, Obama's continued spending and bailouts have been a major reason we've not been able to recover, but it doesn't change the fact that TARP is what sent us spiraling into recession.). So, Carly needs to tell voters if she still feels the same way and why. And, since we've never recovered and it's looking like the economy is on the threshold of getting a whole lot worse in the near future, she should tell us if she'd advocate another TARP-like bailout.4.) CNN reported that in 2011 Carly stood with establishment Republican leadership and Obama in opposition to the Republicans who were against raising the debt ceiling without real spending cuts. She needs to tell voters if she still feels the same way and why. She also needs to explain whether she'd advocate raising the debt ceiling again, as we're about to see the GOP leadership do yet another time this fall, and if she does believe it should be raised again, why this continued added debt is good for America.5.) Recently Matt Lewis at the Daily Caller raised an important concern. He writes, "Just as Carly Fiorina was starting to impress, she decided to play the victim card." He then goes on to tell how, when asked whether she is running for the vice presidential spot she plays the gender card and challenges those who raise the question by saying that no one asks a man if that's what they are doing. But she is wrong, as Lewis points out. He gives many examples the same question being raised of men in the campaign. Carly, however, has decided to try to use gender to her advantage in this situation to intimidate those who would ask such a question.Interestingly, it looks like she also played the gender card when Megyn Kelly got into a battle with Donald Trump. She threw support behind Kelly and either did it strictly because they are both women or because she didn't do her homework about what happened. (I've written about Kelly and Trump numerous times in recent weeks.) Carly claims to be a conservative, but a conservative doesn't consider gender, race, ethnicity, or anything else that's not substantive when it comes to a decision. They look at qualifications and the minute any candidate raises something like this, it should be pointed out that this is nothing but pandering to some people based on something that's superficial. So, Ms. Fiorina needs to explain why she would use her gender to challenge the person asking the question when the same answer has been sought of numerous other candidates who all happen to be male.6.) Back in February of this year, National Journal reported that Carly believes humans contribute to climate change. During his 2008 run for the presidency, John McCain was promoting a cap-and-trade solution to climate change and Carly was working with his campaign. The San Francisco Gate reported Carly saying, "John McCain will create a cap-and-trade system that will encourage the development of alternative energy sources."So, she's bought into the lies about climate change. She needs to be explain whether she still believes in it and why. Also, she needs to explain how a cap-and-trade program would benefit us and not bankrupt us.7.)The Right Scoop reported that Carly was against conservative efforts to defund Obamacare in 2013. She felt that since Romney lost the election to Obama that conservatives should not delay or defund Obamacare. Dr. Ben Carson has said that Obamacare was "the worst thing that has happened in this nation since slavery." Carly needs to explain how not stopping it is good for America and why she wouldn't fight it. There's no excuse for any politician supporting Obamacare and not fighting to stop it.8.) The Wall Street Journal reported that Carly said she would have voted to support Sonia Sotomayor's appointment to the Supreme Court. This makes me wonder if her gender card is being shown again because it makes no sense that any Republican should support the appointment of an extreme liberal judge. Or does she hold John McCain's view that a president should get the appointees he chooses with no challenge from the Senate, even though it's the Senate's job to scrutinize and make sure appointees are good for America? The court already loses too many decisions to leftists who don't hold the Constitution with regard. Carly needs to answer why she would support such a nomination.9.) The San Francisco Gate reported that Carly is against using abortion as a litmus test for SCOTUS appointments. Over 50 million babies have been killed in America since the passage of Roe v. Wade. The question for Carly is how anyone could NOT have abortion as a litmus test for a SCOTUS appointment. A civil society cannot stand for the murder of the innocent, otherwise we're no better than Stalin, Mao, or Hitler.10.) Even though she is against the Iran nuclear deal, Carly needs to explain why, as reported by the San Jose Mercury News, while she was in charge at HP they used Redington Gulf, a wholesaler, to circumvent sanctions the U. S. had against Iran. And why an HP subsidiary in Russia bribed officials for contracts, as reported by USA Today.She's running for president and is claiming to stand against our enemies. She claims to have integrity. She needs to answer for the actions HP took under her direction that went against America. Would she, as president, do some back room deals that twisted the laws to get deals through that could endanger America and our allies? How can we be sure she can be trusted?Those are 10 things voters should demand explanations for before considering supporting Carly Fiorina. Sadly, too often American voters don't do homework or seek answers to important questions. In fact, they rarely know of issues that should be asked about because they do no research on their own. They simply listen to pundits, the media, and talk show hosts and draw conclusions. And that's how we end up with the kind of people we already have in office.

Saving America Is About Nationalism vs Globalism

Doug is 1st Place Winner of the 50 Great Writers You Should Be Reading Award!

How Should Christians Vote in 2016?

While Donald Trump got the vast majority of the Christian vote in the primaries, now that the primaries are over some who did not support him are struggling with their vote. What should they do? Can they eliminate their responsibility by saying they wash their hands of the election results and either not vote or vote for a candidate that is guaranteed to lose? Or if they look at the Bible will they find that, like Pontius Pilate, they cannot wash their hands of their responsibility? Well known Christian radio and TV host had Janet Parshall on his show to discuss it. You can click here to go to his Facebook page with her excellent response.

IMPORTANT: Candidate Eligibility Is Nothing To Ignore

A lot of people scoff at the issue of candidate eligibility. It's no laughing matter. Because it wasn't taken seriously in 2008, we've had severe changes in our government from which we may never recover. Now, in 2016, we are faced with serious eligibility problems among the Republican candidates. I've spent months pulling together the information included in this lengthy paper. It is an important issue and you should be informed BEFORE YOU VOTE.Click here to read and/or download this information.

For more information and another excellent article and video on the topic click here.

Disclaimer

This work was not created to provide any legal, business,professional, or personal counsel or advice. It is an opinion and should be treated as such. This should not be considered the only source of information. Readers are encouraged to refer to other sources for additional information. TheAuthor shall have no liability or responsibility to any persons,groups, or businesses with respect to any loss or damagecaused, directly or indirectly, by the information provided; claimany responsibility in decisions made by any persons, entity, orcompany based upon the provided information; or make anyguarantees or warranties implied or otherwise to the accuracyof the included material.


"C'mon man. I don't know where that came from," Meyer told CBS Sports. "It's like a new generation of excuse. [Herman] said, 'I can't rub pixie dust on this thing.' He got a dose of realiTy"

The full quote by Herman in Saturday's postgame: "If we all thought that we were going to come in here and in nine months sprinkle some fairy dust on this team and think that we've arrived then we're wrong."
"Players read that," Meyer continued.
Herman replaced Strong at Texas. Strong was an assistant for four Florida coaches, including Meyer from 2005-09, when he led a dominant defense that helped the program win two national championships.
It's not clear if Muschamp ever directly suggested the cupboard was bare when he took over for Meyer. However, at the time of his Florida firing in 2014, Muschamp told CBS Sports, "[We] changed the culture of the program that was labeled by the previous head coach [Meyer] as 'broken.' He said it. I didn't."

Meyer saw 14 of his recruits selected in the three drafts after his departure following the 2010 season.
"You had Jeff Driskel, Chris Rainey, Jeff Demps, that whole defense got drafted," Meyer pointed out.
Rainey was selected in the fifth round in 2012. Demps went undrafted but played briefly in the NFL. Both were tailbacks. Seven Meyer-recruited Florida defenders were drafted from 2011-13.
Driskel, a quarterback, was recruited by Meyer and signed in Muschamp's first recruiting class.

"That's like, when I got here, everybody wanted me to say Jim Tressel left the cupboard bare," Meyer continued. "If I heard any assistant coach [say that], they'd be gone. You're done.
"Those are your players. I hear TV guys [say], 'Wait until they get their own players in there.' They're our players. What do you mean 'their players?' The minute you sign a contract, they're your players.
"You didn't choose me, I chose you. You're mine, absolutely. I love you, and I'm going to kick the **** out of you, and we're going to do it right ***8230;
"[Blaming players] drives me insane."

He had a few Top 10s too. More than VT ever had, we would dominate with those kids. Urban, here, is right. The cupboard is never bare in a place like texas. oh so sawry massa herman you dont have the no1 recruit team. time to tank!


Institutional shelter to protect adolescent victims of domestic violence: theory or practice?
To understand and analyze, from the perspective of adolescent victims of domestic violence who were cared for in an institution in Campinas-SP, the protective factors to which they are submitted and / or have access. This was qualitative research, with data collection occurring through focus groups with 17 adolescents, and semistructured interviews with seven of them; the data analysis was based on content analysis, using a thematic modality. Two themes emerged, entitled Four Walls and Trust. We discuss the context of institutional care, that despite the efforts made contemporaneously, still maintains an authoritarian environment; the importance of the bond and trust established with some employees, acting as protective factors for the adolescents and the protective aspect of religiosity. It is understood that these considerations should be valued and reinforced through the healthcare services provided to children and adolescents, as they contribute to the promotion of the physical and mental health of this population.


---
author:
- |
    Soheil Behnezhad\
    `soheil@cs.umd.edu`
- |
    MohammadTaghi Hajiaghayi\
    `hajiagha@cs.umd.edu`
- |
    David G. Harris[^1]\
    `davidgharris29@gmail.com`
bibliography:
- 'references.bib'
- 'referencesMPC.bib'
title: 'Exponentially Faster Massively Parallel Maximal Matching[^2]'
---

[^1]: Department of Computer Science, University of Maryland, College Park, MD 20742.

[^2]: A preliminary version of this paper is to appear in the proceedings of [*The 60th Annual IEEE Symposium on Foundations of Computer Science* ]{}(FOCS 2019).


Introduction {#Sec1}
============

The role of egg size in invertebrate reproduction {#Sec2}
-------------------------------------------------

The amount of energy invested into offspring by the mother has a direct impact on the length of larval development, resistance to starvation in larvae and the size of larvae at hatching and metamorphosis (Sinervo and McEdward [@CR63]; Reitzel et al. [@CR56]; Oliphant et al. [@CR54]; Oliphant and Thatje [@CR53]). An easy-to-obtain ecological parameter, egg size, has frequently been used as a corollary of per offspring (maternal) investment (POI; Jaeckle [@CR36]; Anger [@CR3]; Moran and McAlister [@CR51]). Per offspring investment, in most cases reflected in egg size, dictates whether larvae of aquatic invertebrates develop into planktotrophic (feeding) or lecithotrophic (non-feeding) stages (Miles and Clark [@CR49]). The hypothesis that egg size is proportional to energy content (e.g. Oliphant et al. [@CR54]; Oliphant and Thatje [@CR53]) has been supported by cases in which empirical assessments between species were made (Clarke [@CR14]; Jaeckle [@CR36]; Anger et al. [@CR4]; McEdward and Morgan [@CR46]). In this context, several physical factors have been investigated for their correlation with egg size in an attempt to resolve the various effects of the environment on POI. Water temperature, salinity, water pollution, maternal size and condition at reproduction all seem to play a part in the partitioning of energy into eggs, although trends are not necessarily consistent across phyla (Clarke [@CR13]; Atkinson [@CR6]; Bernardo [@CR8]; Wehrtmann and Kattner [@CR73]; Collin [@CR15]; Fischer et al. [@CR24], [@CR25]). Stochastic variability of egg size has also been examined, and the influence on interspecific variability was found to be insignificant (McEdward and Morgan [@CR46]).

Temperature-driven latitudinal shifts in energy provisioning into eggs have long been suggested for some invertebrate orders, especially decapod crustaceans and molluscs (Thorson [@CR71]; Hart and McLaren [@CR33]; Clarke [@CR13]; Ernsting and Isaaks [@CR23]; Arntz and Gili [@CR5]). A trend in an increase in egg volume with water depth has also been described in neogastropod molluscs (Buccinidae) and decapod crustaceans (Munidopsidae, Chirostylidae) (Smith et al. [@CR64]). Furthermore, a study of latitudinally widespread cancrid crab showed that---in the absence of food limitation---a shift in embryonic nutrition from protein to lipid metabolism is entirely dependant on temperature and on the lower temperature range tolerated by the species. This is reflected by a latitudinal cline in egg, as well as larval size and morphology (Thatje and Bacardit [@CR66]; Fischer et al. [@CR24], [@CR25]; Weiss et al. [@CR74]). The scarce evidence for a link between reproductive ecology and temperature along latitudinal (temperature) clines has often been attributed to increased seasonality rather than temperature alone (Clarke [@CR13]; Thatje et al. [@CR68]). Recent work focusing on the intraspecific level suggested that temperature is the main driver of energy allocation into offspring (Giménez [@CR27]; Oliphant et al. [@CR54]; Oliphant and Thatje [@CR53]; Gonzalez-Ortegón and Giménez [@CR28]).

Despite the summarised evidence, the widely varying life histories and ecological traits that exist across marine invertebrate taxa have presented scientists with difficulties when trying to understand better the environmental factors that govern per offspring investment (e.g. Miner et al. [@CR50]; Thatje et al. [@CR70]). Large comparative works---to date---focus mainly on echinoderms and molluscs (Hadfield and Switzer-Dunlap [@CR29]; Emlet et al. [@CR21]; Lessios [@CR41]; Atkinson et al. [@CR7]; Collin [@CR15]). Only one study on an anomuran crab species, the mole crab *Emerita analoga*, demonstrated a lack of correlation between egg size and temperature on beaches in California (Dugan et al. [@CR19]). To the best of our knowledge, there is no study available that describes the drivers of POI and within a well-construed phylogenetic scenario (but for discussion see, Strathmann [@CR65]).

Evolutionary history and biogeography of the Lithodidae {#Sec3}
-------------------------------------------------------

The family Lithodidae comprises two subfamilies: the Lithodinae and the Hapalogastrinae. The Hapalogastrinae are small, shallow- or intertidal-dwelling crabs with soft (uncalcified) abdomens. Their range is restricted to the high latitudes of the north Pacific, where temperatures are below 16 °C during the period of larval development (Hall and Thatje [@CR31]). The Lithodinae have a wide diversity of ecological types, with six intertidal or subtidal genera in the north Pacific, and four genera with wider bathymetric ranges inhabiting cold waters (predominantly in the deep sea) globally (Zaklan [@CR75]; Hall and Thatje [@CR31]).

Molecular and distributional evidence indicate that lithodids evolved from ancestors inhabiting kelp holdfasts in the shallow waters of the north Pacific (Cunningham et al. [@CR17]; Zaklan [@CR75]), and it is most parsimonious to assume that such ancestors had a planktotrophic larval phase (Fig. [1](#Fig1){ref-type="fig"}; lithodid phylogeny after Hall [@CR30]). Lithodid groups that submerged and radiated into deep waters outside the north Pacific are thought to have made the transition from ancestral larval planktotrophy to lecithotrophy (Cunningham et al. [@CR17]; Hall and Thatje [@CR31]). "Deep-sea" forms of the Lithodidae are known to have emerged a number of times into shallow waters in subantarctic South America (3 cases: *Lithodes santolla*, *L. confundens* and *Paralomis granulosa*) and subarctic north Atlantic (1 case: *L. maja*). In these cases, shallow-water crabs share a lecithotrophic mode of larval development (for discussion see, Strathmann [@CR65]) with their deep-sea relatives (Anger [@CR2]; Thatje and Mestre [@CR67]).Fig. 1Schematic phylogeny of the Lithodinae and Hapalogastrinae adapted from Hall ([@CR30]). Representation is based on Bayesian analyses of an alignment of 39 lithodid species belonging to 10 genera using genes COI, 16S, 28S and ITS1. Species within monophyletic genera are condensed to a single taxon label, and polyphyletic or paraphyletic genera are indicated as such by multiple taxon labels (*Paralithodes*). Less frequent alternative topologies are indicated by *dotted lines* on the same tree. Probabilities based on Bayesian analysis represented at internal nodes. Outgroup species are taken from the anomuran genus *Aegla* (species *platensis*, *intercalata*, *longirostris*; see Hall [@CR30], for further details). Maps indicate the distribution for each taxonomic lineage (global = *dark circle* vs. north Pacific); larval developmental type is indicated as planktotrophic (feeding) larvae or lecithotrophic (non-feeding) larvae

Experimental data have shown that many species of Lithodidae have fully food-independent (lecithotrophic) larval development (Anger [@CR2]; Calcagno et al. [@CR11]; Morley et al. [@CR52]; Watts et al. [@CR72]; Thatje and Mestre [@CR67]; Shirley and Zhou [@CR61]; Calcagno et al. [@CR10]). An obligatory non-feeding larval mode is accompanied by physiological and anatomical traits in lithodids, such as the reduced development of larval mouthparts (Campodónico and Guzmán [@CR12]; McLaughlin et al. [@CR48]; Watts et al. [@CR72]) or a lack of digestive enzymes (Kattner et al. [@CR39]; Saborowski et al. [@CR59]). In contrast, lithodid species of the genus *Paralithodes* (Paul et al. [@CR55]; Eppelbaum and Borisov [@CR22]) as well as any species of the Hapalogastrinae studied to date (Crain [@CR16]; Kim and Hong [@CR40]; Duguid and Page [@CR20]; Jensen [@CR37]; Hong et al. [@CR35]) are known to have food-dependent zoeal stages. Zoeal planktotrophy is found in north Pacific Lithodidae but is not known in any lithodid from outside that region.

This paper examines egg traits indicative of per offspring investment (POI) and larval developmental mode within the globally distributed decapod crustacean family Lithodidae. For the first time, we link physiological and ecological traits to the global radiation of this large family of mobile benthic crustaceans (after Hall and Thatje [@CR31]). Temperature has long been proposed to drive POI within latitudinal clines (generally known as "Thorson's rule"); however, there is currently no study available that attempts to test this macroecological observation in an evolutionary context.

Materials and methods {#Sec4}
=====================

Acquiring egg data {#Sec5}
------------------

Lithodid egg samples were obtained from the National Museum of Natural History, Smithsonian Institute, Washington, USA, the Muséum national d'Histoire naturelle, Paris, France, the Natural History Museum, London, UK, the Centro de Estudios Avanzados de Blanes, Spain, and the Senckenberg Forschungsinstitut und Naturmuseum, Frankfurt, Germany. Egg data used in this study were obtained from females stored in 70 % ethanol and compared with data obtained from the literature. We collected original egg-size data from ovigerous females (38 species, one female each; 9 lithodid genera; Supplementary Information). Eggs held on the fifth abdominal pleopod were removed by scalpel and placed into a vial of 70 % ethanol for later analysis. Egg measurements, accurate to the nearest 0.02 mm, were taken using an eyepiece graticule on a Leica dissecting microscope. Only eggs that were intact and not deformed were used for measurement. Developmental stage of the embryo was considered in analyses, and eggs were classed as unfertilised/early, uneyed or eyed. Only early development eggs, which are of spherical shape, were considered in this study; no samples were considered that contained late-stage (with developing or fully developed eyes visible) embryos. In all cases, the length of the egg was measured. For this study, we randomly selected and measured at least 30 eggs from each individual.

Preservation analysis {#Sec6}
---------------------

An initial comparison of our data with that from the literature indicates a slight effect of ethanol preservation on egg size (Fig. [2](#Fig2){ref-type="fig"}). To test for the effect of methodological bias related to preservation, we compared the diameters of 30 randomly selected fresh eggs with those preserved for up to 1 month in 70 % ethanol. For this, we selected one species with lecithotrophic (non-feeding) larval development (*Lithodes confundens*, Fig. [2](#Fig2){ref-type="fig"}a) and one with planktotrophic (feeding) development (*Paralithodes camtschaticus*, Fig. [2](#Fig2){ref-type="fig"}b).Fig. 2Effect of ethanol preservation on egg size. Range in diameter of eggs taken from *Lithodes confundens* (**a**) and *Paralithodes camtschaticus* (**b**) after a period of incubation in 70 % ethanol. Eggs are removed from the fifth pereiopod of a fresh ovigerous female. Measurements of 30 eggs are taken using an eyepiece graticule at each time interval shown

Assessment of in situ temperature {#Sec7}
---------------------------------

In situ water temperature at time of sampling was obtained revising sampling location data available from museum collection archives and for each ovigerous female used in the present study. Where a local in situ temperature was not recorded at the time of capture, the temperature was estimated from data in the World Ocean Atlas (Locarnini et al. [@CR42]) using latitude, depth, longitude and month of recovery from sampling records. In addition, variation in temperature at sampling locations (if known) has been visualised (Fig. [3](#Fig3){ref-type="fig"}).Fig. 3Effect of depth and temperature on egg size in the family Lithodidae. Average size of eggs taken from individual lithodids, classified according to genus. Figured in relation to **a** environmental temperature of the location of catch for the ovigerous females from which eggs are sampled. Temperature data extracted from the World Ocean Atlas (cf "[Materials and methods](#Sec4){ref-type="sec"}") using sample coordinates and month of capture to obtain estimates of temperature at location (*horizontal error bars* depict the range of temperatures recorded at each station, if known; vertical error bars depict range in egg diameter for each individual sampled). *Regression lines* are shown for genera *Paralomis* and *Lithodes*; **b** depth of sampling of the ovigerous females from which the eggs are obtained; horizontal error bars depict range in egg size for each individual sampled (for details, see "[Materials and methods](#Sec4){ref-type="sec"}") \[Groups represented in this figure: *Neolithodes*: 2 species; *Lithodes*: 10 species; *Paralomis*: 17 species; Shallow-water Lithodinae includes genera (*Paralithodes*, *Rhinolithodes*, *Lopholithodes*): 4 species; Hapalogastrinae includes genera (*Cryptolithodes*, *Oedignathus,* *Hapalogaster*): 5 species\]

Per offspring investment and phylogenetic relatedness {#Sec8}
-----------------------------------------------------

We assessed the distribution of egg traits for different lineages of the Lithodidae (subfamilies: Lithodinae and Hapalogastrinae) and based on established phylogenetic reconstruction based on Bayesian analyses of an alignment of 39 lithodid species belonging to 10 genera, using genes COI, 16S, 28S and ITS1. Species within monophyletic genera are condensed to a single taxon label; polyphyletic or paraphyletic genera are indicated as such by multiple taxon labels (for further details, see; Hall and Thatje [@CR31]; Hall [@CR30]).

In the Lithodidae, eggs size \<1.5 mm is known to represent a planktotrophic (feeding) mode in larval development, representative of shallow-water genera of the Hapalogastrinae (*Oedignathus, Hapalogaster, Cryptolithodes*), as well as for the shallow-water genera of the Lithodinae (*Paralithodes, Lopholithodes, Phyllolithodes*, Fig. [2](#Fig2){ref-type="fig"}). The three most speciose lithodinid genera (*Lithodes*, *Neolithodes*, *Paralomis*) as well as *Glyptolithodes* have eggs \>1.5 mm in size and are considered to follow a lecithotrophic (non-feeding) mode in larval development (Fig. [1](#Fig1){ref-type="fig"}); most of these inhabit the deep sea. The early ontogeny of the Lithodidae remains one of the best-studied cases for divergent reproductive traits in the early development of marine invertebrates; evidence for developmental modes and larval energetics are largely based on an extensive body of the literature, which provides the baseline to this study (for review see; Thatje et al. [@CR69]; Hall [@CR30]; Thatje and Mestre [@CR67]).

Statistical analyses {#Sec9}
--------------------

We applied the Holm--Sidak method of pair-wise comparison for normally distributed data, the average size of eggs produced by individuals in the genera of the Lithodidae. We used this test to correct for multiple *t* test and in order to present significance between genera; the Sidak modification of the Holm test makes it a more powerful, especially when applied to many comparisons at once (Šidák [@CR62]; Holm [@CR34]). Furthermore, we assessed egg size variability with regard to temperature and depth using polynomial regression analysis. For two genera with the largest available datasets, *Lithodes* and *Paralomis*, statistical polynomial regressions were calculated and in order to test for a unimodal relationship with a single maximum or minimum value.

Results {#Sec10}
=======

Egg preservation analysis {#Sec11}
-------------------------

In a comparison of ethanol-preserved and fresh eggs, each batch of preserved eggs lost 1.5 % in *Lithodes confundens* and 4.5 % in *Paralithodes camtschaticus* of their diameter over the course of a month compared with the mean measurement of unpreserved eggs (Fig. [2](#Fig2){ref-type="fig"}). In both species, most of the change in egg size occurred within the first 12 h of preservation, with an insignificant decrease in egg size from 24 h onward. All of the data used in the main study were taken from eggs preserved for more than 24 h in 70 % ethanol, and this slight skew is accepted as a uniform bias in the data which should not affect the interpretation of the results.

Egg size variability within genera {#Sec12}
----------------------------------

Genera that are predominantly found in the deep sea---*Neolithodes*, *Lithodes* and *Paralomis* (including shallow-water species *P. granulosa*, *L. santolla*, *L. confundens*, *L. maja*)---have eggs more than 1.7 mm diameter (Fig. [3](#Fig3){ref-type="fig"}a, b; also see; Supplementary Material). Using the Holm--Sidak method of pair-wise comparison for normally distributed data, the average size of eggs produced by individuals in genera *Lithodes* (2.24 mm) and *Neolithodes* (2.47 mm) was found to be significantly higher (*p* \< 0.01) than those in members of the genus *Paralomis* (1.93 mm).

Shallow-water representatives of the Hapalogastrinae (*Oedignathus, Hapalogaster*, *Cryptolithodes*) and Lithodinae (*Paralithodes*, *Lopholithodes*) have average egg diameters ranging from 0.63 to 1.15 mm and are significantly smaller (*p* \< 0.01) than those produced by deep-sea genera (*Neolithodes*, *Lithodes* and *Paralomis*).

Egg size variability with regard to temperature and depth {#Sec13}
---------------------------------------------------------

Within the members of deep-sea lithodid genera (*Neolithodes*, *Paralomis, Lithodes*), including species that currently inhabit shallow waters (see previous section) egg size decreases with increasing temperature (Fig. [3](#Fig3){ref-type="fig"}a). The largest eggs (some \>2.4 mm) are observed in the abyssal genus *Neolithodes*, which inhabits waters up to 3500 m deep where temperatures are between 1 and 4 °C.

For two genera with the largest available datasets, *Lithodes* and *Paralomis*, statistical regressions were calculated. Linear regression indicated a relationship between egg size and environmental temperature (*r*^2^ = 0.68; intercept = 2.588, slope = −0.0726) for genus *Lithodes* and (*r*^2^ = 0.569; intercept = 2.15, slope = −0.046) for genus *Paralomis*. Within the genus *Paralomis*, a further second-order test of regression demonstrated a strong relationship (*r*^2^ = 0.81) between egg size and a function of environmental temperature.

No strong relationship was found between egg size and sample depth (a correlate of hydrostatic pressure) for the genera *Paralomis* and *Lithodes* (*r*^2^ = 0.0703 and *r*^2^ = 0.338, respectively; *p* values \<0.01).

Per offspring investment and phylogenetic relatedness {#Sec14}
-----------------------------------------------------

Reproductive traits in the Lithodinae are strongly lineage specific, with the deep-sea genera *Lithodes*, *Paralomis* and *Neolithodes* demonstrating a lecithotrophic mode (egg size \>1.5 mm) in larval development, whereas the shallow-water genera *Lopholithodes*, *Phyllolithodes* and *Paralithodes* have a planktotrophic mode (\<1.5 mm) in development. The shallow-water Hapalogastrinae (genera; *Cryptolithodes*, *Oedignathus* and *Hapalogaster*) also follow a planktotrophic mode (egg size \< 1.15 mm) in larval development (see Fig. [1](#Fig1){ref-type="fig"}; phylogeny after Hall and Thatje [@CR31]). There are few species of the Lithodinae occurring in shallow seas (*P. granulosa*, *L. santolla*, *L. confundens*, *L. maja*), all of which also show lecithotrophy in larval development (Campodónico and Guzmán [@CR12]; Anger [@CR2]; Kattner et al. [@CR39]; Calcagno et al. [@CR11]).

Discussion {#Sec15}
==========

Methodological considerations {#Sec16}
-----------------------------

This study is making use of lithodid crab egg samples obtained from various international museum collections. We experimentally assessed the potential effect of (ethanol) preservation of eggs in order to consider any potential bias of long-term storage on egg size. We found a minor, but consistent effect of preservation on the size of eggs. Eggs shrink by 1.5--4.5 % of their original size after preservation in 70 % ethanol (Fig. [2](#Fig2){ref-type="fig"}). However, this is not expected to affect the analysis, since all specimens had been preserved in 70 % ethanol (also see: Zaklan [@CR75]; Hall [@CR30]).

In this analysis, we used in situ temperature at each sampling location and time of year as a parameter for assessing temperature-driven effects on per offspring investment, as indicated by egg size (Anger et al. [@CR4]). Seasonal bathymetric migration into shallower---and warmer---waters is known in a few species of shallow-water living (continental shelf) Lithodinae and most likely for the purpose of larval release. Such migration into warmer waters may potentially affect the use of energy by embryos and reduce egg size (e.g. *Paralithodes camtchaticus*, Jørgensen and Nilssen [@CR38]; *Lithodes confundens*, Lovrich et al. [@CR43]). However, our egg data refer to the early stage in embryo development (see "[Materials and methods](#Sec4){ref-type="sec"}"), which is taking place in deeper waters. In addition, oogenesis---which is affecting POI---is also taking place in deeper, cooler waters, justifying the present method. Nevertheless, any such potential thermal effect of increased temperature in shallower waters would, indeed, lead to an underestimation of the already significant effect of temperature on POI demonstrated in this study.

Environmental influences on reproductive traits {#Sec17}
-----------------------------------------------

There is a strong correlation between egg size and environmental temperature within lithodid genera *Lithodes* and *Paralomis*, and regardless of habitat depth. Variations in POI have previously been linked with other environmental factors including maternal diet or food availability, quality of oviposition site, density of conspecifics and predation risk (Fox and Czesak [@CR26]; Anger [@CR3]; Oliphant et al. [@CR54]; Oliphant and Thatje [@CR53]). Differences in offspring size within species are also commonly observed between seasons and along latitudinal or bathymetric gradients, and have been described by temperature effects (Clarke [@CR13]; Wehrtmann and Kattner [@CR73]; Morley et al. [@CR52]; Rosa et al. [@CR57]).

Temperature is likely to be a key mediator of phenotypic variation in all ectotherms (Atkinson [@CR6]; Oliphant et al. [@CR54]; Oliphant and Thatje [@CR53]). Low metabolic rate and protracted growth of females at low temperature reduces the cost of somatic maintenance, increasing the proportion of available resources that can be allocated to vitellogenesis (Sheader [@CR60]). At low temperatures, selection may also favour the production of larger offspring and promote the abbreviated development of lecithotrophic larval instars, as observed in cold-water adapted lithodid crabs from subantarctic and Antarctic waters (Campodónico and Guzmán [@CR12]; Lovrich et al. [@CR44]; Watts et al. [@CR72]; Thatje and Mestre [@CR67]). Such early life history adaptations to low temperatures have often been discussed to support larval survival in regions where the period of primary productivity is short or pronounced, such as at high latitudes or in the deep sea (Clarke [@CR14], Clarke [@CR13]; Thatje et al. [@CR68]).

Additionally, oxygen limitation of large embryos is more likely to occur at higher than lower temperatures (Davis [@CR18]); in warm-water conditions, smaller eggs may be favoured for their lower surface/volume ratio, thus constraining egg size. Interestingly, recent work by Smith et al. ([@CR64]) for the first time indicated an increase in metabolic demand for larval development at lower temperature and under hyperbaric conditions, as representative of the deep sea. Such increase in metabolic cost observed under hyperbaric conditions may, therefore, contribute further to the long-standing hypothesis of an increase in POI at low temperatures, and by increasing the cost of reproduction (for discussion see, Oliphant et al. [@CR54]; Oliphant and Thatje [@CR53]). The present work does not provide any evidence for a depth-related effect on POI.

The factors governing the development of larger eggs are diverse and with temperature most likely being a key factor in driving POI in the Lithodidae. Indeed, the evolutionary age---or history---of a group of species or clade may be key in determining the role of an environmental factor plays in the selection for reproductive traits.

Evolutionary drivers of lecithotrophy {#Sec18}
-------------------------------------

Here, we have shown that significantly larger eggs are produced in colder waters within lithodid genera, indicating some level of physiological plasticity in POI in response to environmental conditions. Based on these data, we suggest environmental temperature to influence egg size (POI) and, by extension, larval developmental traits within lithodid crab lineages (Fig. [1](#Fig1){ref-type="fig"}). The effect of temperature on egg size as a correlate of POI, however, is of a much lower order than the size difference between eggs from shallow-water north Pacific lithodids and eggs from deep-sea lithodid genera. This profound division is further evidence for the divergent lithodid reproductive strategies between deep-sea and shallow-water lineages that have been shown in previous physiological experiments (see Introduction); therefore, the development of lecithotrophic (food-independent) larval developments in lithodid crabs has likely played a pivotal role in the radiation and diversification of the family. The evolution of lecithotrophy has previously been regarded a main---if not key---condition that allowed the three most diverse extant genera (*Lithodes*, *Neolithodes* and *Paralomis*) to radiate globally through the cold stenothermal environment of the deep sea, where the lack of continuous food supply selects against feeding larvae (Hall and Thatje [@CR31]). The theory of linked submergence (migration to greater depth) and range expansion in deep-sea lithodid lineages is supported by genetic and other physiological (temperature, hydrostatic pressure) bottlenecks previously discussed for the family Lithodidae (Roughgarden [@CR58]; McKitrick [@CR47]; McEdward [@CR45]; Hall and Thatje [@CR31]; Hall [@CR30]; Hall and Thatje [@CR32]). In those lithodid genera with an expanded bathymetric range, the selection for lecithotrophy allowed larval development to take place over an extended period (lasting a year or longer), disconnected from limited periods of phytoplankton blooms in surface waters (Thatje et al. [@CR68], [@CR69]; Thatje and Mestre [@CR67]). This stands in strong contrast with most other lithodid genera that restrict their distribution to shallow waters of the north Pacific and have planktotrophic larval developmental stages (Duguid and Page [@CR20]; Hall and Thatje [@CR31]). Food limitation has frequently been discussed to be a main driver of lecithotrophic larval development in freshwater crabs and, undoubtedly, is likely to play an important role in the evolution of reproductive traits in marine invertebrates, too (for discussion see, Anger [@CR1]).

Our finding that lower habitat temperature is a strong predictor of increasing egg size supports previous evidence that latitudinal temperature clines influence POI among other crustaceans and marine invertebrates (Thorson [@CR71]; Clarke [@CR13]; Wehrtmann and Kattner [@CR73]; Fischer et al. [@CR24], [@CR25]; Weiss et al. [@CR74]; Oliphant et al. [@CR54]; Oliphant and Thatje [@CR53]). Here, we advocate that temperature, and within a framework of previously established phylogeny, is the predominant factor influencing per offspring investment (POI). It is likely that the evolutionary history ("experience") of a species affects the role of an environmental factor plays in the selection for species-specific reproductive traits.

Electronic supplementary material
=================================

 {#Sec19}

Below is the link to the electronic supplementary material. Supplementary material 1 (DOC 92 kb)

Reviewed by undisclosed experts.

Thanks are due to staff at the National Museum of Natural History, Smithsonian Institute, Washington, USA, and especially to Rafael Lemaitre and Karen Reed; Régis Cleva, Muséum national d'Histoire naturelle, Paris, France; Paul Clark at the Natural History Museum, London, UK; Enrique Macpherson, Centro de Estudios Avanzados de Blanes, Spain; Michael Türkay, Senckenberg Forschungsinstitut und Naturmuseum, Frankfurt, Germany. We thank two anonymous reviewers for their constructive commenting on this paper.

[^1]: Responsible Editor: T. Reusch.


Q:

Loading or getting ready message

i have some web based application that creates a zip file when user asks for it. and it takes around 5 sec of time which is uncertain.. so i want to show him a loading sceen which should disable my main screen for the time being and show loading oo processing animation something..
i am using jsp servlets
Update: i dont want to use jQuery
Edit: implemented using jQuery but want to do the same without it
thanks.

A:

Use jQuery to lock browser screen and show loading process. You could use ajax to make requests and receive responses asynchronously.
Why use jQuery?

It uses KISS principle - Keep It Simple Stupid
It has very good documentation and tutorials
The community is very active, helpful, and warm
The core file’s packed size is small
It deploys almost use-at-will approach
It has strong logic and workflow and is easily extensible

Since you do not want to use jQuery you have to deal with javascript basics like manipulating the DOM.
Basic ajax tutorial:

http://www.ibm.com/developerworks/web/library/wa-ajaxintro1.html
http://www.ibm.com/developerworks/web/library/wa-ajaxintro2/
http://www.ibm.com/developerworks/web/library/wa-ajaxintro3/

This tutorials are on DOM manipulation:

http://www.ibm.com/developerworks/web/library/wa-ajaxintro4/
http://www.ibm.com/developerworks/web/library/wa-ajaxintro5/
http://www.ibm.com/developerworks/web/library/wa-ajaxintro6/


The Utility of History: Perspectives on International Development

The Utility of History: Perspectives on International Development

Monday, July 6, 2015

Victoria Hawkins, student blogger at Congress 2015

Don’t say history doesn’t have the power to change the future. At Congress 2015, Historians of Humanitarian Aid held a panel on the "utility of history" in today’s development in the Global South. Jill Campbell-Miller of St. Mary’s University (pictured) presented a case study of Canadian bi-lateral assistance to India in the 1950 to illustrate how the history of development practice is important and useful for both scholars and practitioners of international development today.

Campbell-Miller argued that at the very least, history can have an effect on institutional memory, the collective understanding of an institution’s past. That understanding could potentially contribute to better judgements in the present and improved plans for future development. The idea seems simple, but moderator Ian Smillie noted that memory is a huge problem where international development is concerned. Campbell-Miller argued that developers’ access to well-researched and well-written histories could break familiar patterns of the past and even challenge assumptions about development itself.

John F. Devlin from the University of Guelph presented his study on the role of agriculture in the industrialization of Asia. Devlin sought to determine the factors that allowed for the transformation and see how those factors fit with the situation of the Global South. Devlin provided a model for looking at historic successes to solve current development problems. Stephanie Bangarth of King’s University College also presented a series of case studies to illustrate what can be learned from the history of international development.

In the discussion period to follow, Smillie (pictured) noted that a problem in development is the need for results and success: “If we knew how to end poverty we’d have done it by now. We should be treating each project as an experiment, because that’s what development projects are.” Smillie recognized a chronic “failure to learn from failure,” which the panel hopes to eradicate. Kevin Brushett of Royal Military College agreed that a detailed look at history will help us understand “why we keep returning to particular tropes of aid.” June Francis of Simon Fraser University asked, “What accounts for the disparity between the myth and reality of foreign aide?” Ted Cogan of the University of Guelph suggested that Canada in particular has tried to attach foreign aide to stereotypical Canadian values and in reality there is detachment between the ideals of Canadian identity and what is happening on the ground. Devlin added that Canadian identity is “aspiration, not fact”. Historians and social scientists have the task of finding out what foreign aid actually does. Once the reality of the past and present is known more broadly, international development could progress to make a bigger difference.


Q:

Socket.IO WebSocket server/page different hosts

Using Socket.IO's WebSocket I have successfully managed a chat application from my home computer where both the index.html and app.js (server) located together. Since my webhost does not offer WebSockets I want to host the app.js (server) on my computer and the actual webpage where it connects on my webhost. I am having difficulties establishing a connection. My port is forwarded. I believe its something in my app.js that I need to change to establish the link. Here is my code
app.js (server, run off local computer)
var app = require('express').createServer()
var io = require('socket.io').listen(app);

app.listen(8080);

// routing
app.get('/', function (req, res) {
  res.sendfile('http://mywebhost.com/chat.php');
});

// usernames which are currently connected to the chat
var usernames = {};

// rooms which are currently available in chat
var rooms = ['room1','room2','room3'];

io.sockets.on('connection', function (socket) {

// when the client emits 'adduser', this listens and executes
socket.on('adduser', function(username){
    // store the username in the socket session for this client
    socket.username = username;
    // store the room name in the socket session for this client
    socket.room = 'room1';
    // add the client's username to the global list
    usernames[username] = username;
    // send client to room 1
    socket.join('room1');
    // echo to client they've connected
    socket.emit('updatechat', 'SERVER', 'you have connected to room1');
    // echo to room 1 that a person has connected to their room
    socket.broadcast.to('room1').emit('updatechat', 'SERVER', username + ' has connected to this room');
    socket.emit('updaterooms', rooms, 'room1');
});

// when the client emits 'sendchat', this listens and executes
socket.on('sendchat', function (data) {
    // we tell the client to execute 'updatechat' with 2 parameters
    io.sockets.in(socket.room).emit('updatechat', socket.username, data);
});

socket.on('switchRoom', function(newroom){
    // leave the current room (stored in session)
    socket.leave(socket.room);
    // join new room, received as function parameter
    socket.join(newroom);
    socket.emit('updatechat', 'SERVER', 'you have connected to '+ newroom);
    // sent message to OLD room
    socket.broadcast.to(socket.room).emit('updatechat', 'SERVER', socket.username+' has left this room');
    // update socket session room title
    socket.room = newroom;
    socket.broadcast.to(newroom).emit('updatechat', 'SERVER', socket.username+' has joined this room');
    socket.emit('updaterooms', rooms, newroom);
});

// when the user disconnects.. perform this
socket.on('disconnect', function(){
    // remove the username from global usernames list
    delete usernames[socket.username];
    // update list of users in chat, client-side
    io.sockets.emit('updateusers', usernames);
    // echo globally that this client has left
    socket.broadcast.emit('updatechat', 'SERVER', socket.username + ' has disconnected');
    socket.leave(socket.room);
});
});

chat.php (run on webhost)
<script>
var socket = io.connect(\'http://scope.bnetweb.org:8080\');
// various irrelevant javascript

in app.js I am fairly sure I need to change the
app.get('/', function (req, res) {
  res.sendfile('http://mywebhost.com/chat.php');
});

to something else? Or remove it entirely? I think this is Socket.IO's way of making sure no unauthorized connections are made. Any help is greatly appreciated in achieving this.

A:

Solved by simply not splitting them up. IT appears many have this issue that they cannot mix server and client on different hosts. Possibly Socket.IO will make this easier soon. If anyone else comes up with a better alternative, please reply.


Q:

Show hidden element on  tag

I have an image in my HTML code:

I want to show a smaller linkable image over main.jpg when I hold mouse over main.jpg.
(This image is link)
I prefer to use smaller image by CSS.
I tried this:

resize imgae

.resize{
    background:url(resize.jpg) left top no-repeat;
    position:absolute;
    top:0;
    left:0;
    desiplay:none;
    text-indent: -9999px;
}

I want do this just with pure CSS (no JS)...Do you know a trick or an alternative way to  do it?

A:

this will solve your problem

resize imgae

Also correct your css class
change desiplay:none;  to display:none;


Away from Coup Ranks, Saleh Orders Yemeni Media to Expose Houthis

Riyadh- Former president of Yemen Ali Abdullah Saleh urged media outlets and journalists to discredit and expose the truth behind Houthi militias led by Abdulmalik Badreddin al-Houthi, further polarizing coup ranks.

Iran-allied Houthi militias have been leading a coup along with armed loyalists backing ousted president Saleh, but recently a rift within the insurgency has placed Tehran’s allies at odds with Saleh.

Saudi Arabia’s state-owned news agency SPA issued a report showing escalated dispute between Houthis and Saleh’s forces. Other sources based in Sanaa, the coup’s de facto capital in Yemen, cited Saleh increasingly threatening members of the General People’s Congress, a political party chaired by Saleh, to denounce Houthis, labeling them as extremists.

Sources said that Saleh has also granted Yemen’s national broadcasting channel the green light to slam Houthi’s aspirations and expose their affiliations with Iran. Saleh had the national channel focus on Houthis selling allegiance to Tehran for a cheap price.

The channel also said that Houthis are nothing more than a group of militias seeking to loot public assets, ministries, and funds.

Such a clear turn of events shows that Saleh is prepared to fight against Houthis should he be able to secure a deal to end the war.

Saleh’s move came after Abdulmalik showed serious intentions towards killing Saleh– he had ordered Houthi media to stage a distraction story that would point the charge of assassinating Saleh away from militias.

Sources close to the matter in Sana’a said that Saleh has, during a recent meeting with a number of members of the General People’s Congress, threatened to sell out Houthis, describing them as extremists.

This is first outspoken action from Saleh against Iran-backed Houthi militias after the group’s escalation against him and his followers, which asserted Saleh currently studying a plan to retake control over Sana’a from the grip of Houthis.

Yemeni local media sources said both the General People’s Congress and Saleh have prepared a plan to confront Houthis. Their action plan kickstarts with local media demonizing Houthi militiamen and holding the group accountable for all the country’s strife, and that it sold out Yemen to Tehran clerics for cheap.

The final stage would be Saleh armed loyalists confronting the group militarily.

Members of the People’s Congress Party asked Saleh to review all undertable agreements with Houthis in preparation for disengaging from coup ranks.

Asharq Al-Awsat is the world’s premier pan-Arab daily newspaper, printed simultaneously each day on four continents in 14 cities. Launched in London in 1978, Asharq Al-Awsat has established itself as the decisive publication on pan-Arab and international affairs, offering its readers in-depth analysis and exclusive editorials, as well as the most comprehensive coverage of the entire Arab world.