Otway N. Ultrasound‐guided sampling of the lateral abdominal vein in the grey nurse shark (*Carcharias taurus*, Rafinesque 1810). Vet Med Sci. 2020;6:579--586. 10.1002/vms3.272

The peer review history for this article is available at <https://publons.com/publon/10.1002/vms3.272>

**Funding information**

This study forms part of an ongoing research program with grant funding provided by the NSW and Commonwealth Governments.

1. INTRODUCTION {#vms3272-sec-0001}
===============

Blood sampling from the caudal vein (CV) in sharks was first described by Stoskopf, Smith, and Klay ([1984](#vms3272-bib-0025){ref-type="ref"}) and has been used in studies on shark health and husbandry, reproductive endocrinology and animal transport (e.g. Anderson, Huber, & Berzins, [2012](#vms3272-bib-0002){ref-type="ref"}; Henningsen, Murru, Rasmussen, Whitaker, & Violetta, [2008](#vms3272-bib-0010){ref-type="ref"}; Smith, [1992](#vms3272-bib-0019){ref-type="ref"}; Stoskopf, [2010](#vms3272-bib-0024){ref-type="ref"}). The CV is a relatively short vessel located in the haemal arch of the caudal peduncle vertebrae (Muñoz‐Chápuli, [1999](#vms3272-bib-0012){ref-type="ref"}) with blood‐flow dependent on the caudal fin muscle contractions involved with swimming (Satchell, [1999](#vms3272-bib-0018){ref-type="ref"}). This results in reduced flows during periods of inactivity and, more importantly, when restrained for blood sampling. Needle deviation during caudal venipuncture can result in sampling failures while the occlusion of the needle by cartilage and/or inappropriate caudal fin elevation (Stamper, [2004](#vms3272-bib-0023){ref-type="ref"}; Stoskopf et al., [1984](#vms3272-bib-0025){ref-type="ref"}) can lead to small blood volumes. While styletted spinal needles can prevent needle occlusion, they can leave large, exit wounds and when combined with the reduced contractibility of shark skin (Stamper, [2004](#vms3272-bib-0023){ref-type="ref"}), their use in small individuals can be problematic. Consequently, other venipuncture sites including the heart, caudal artery and the dorsal fin blood sinus (Cliff & Thurman, [1984](#vms3272-bib-0004){ref-type="ref"}; Mylniczenko, Curtis, Wilborn, & Young, [2006](#vms3272-bib-0013){ref-type="ref"}; Naples, Mylniczenko, Zachariah, Wilborn, & Young, [2012](#vms3272-bib-0014){ref-type="ref"}) have been used for blood sampling and differences in serum analyte values between venipuncture sites have been evident (Naples et al., [2012](#vms3272-bib-0014){ref-type="ref"}). Nevertheless, the CV has been the preferred vessel for blood sampling with numerous captive and free‐living sharks including the grey nurse shark, *Carcharias taurus*, Rafinesque 1810.

The grey nurse shark in Australian aquaria is synonymous with the sand tiger and ragged‐tooth sharks in similar facilities in the USA, Europe, South Africa and Asia. The shark readily adapts to captivity (Bass, D'Aubrey, & Kistnasamy, [1975](#vms3272-bib-0003){ref-type="ref"}; Dehart, [2004](#vms3272-bib-0005){ref-type="ref"}) and its large size, generally placid temperament, and continuous display of awl‐like teeth makes it one of the commonest and sought‐after sharks in aquaria worldwide (AES, [2008](#vms3272-bib-0001){ref-type="ref"}; Dehart, [2004](#vms3272-bib-0005){ref-type="ref"}). In the wild, the disjunct grey nurse shark populations are listed globally as "Vulnerable" on the International Union for the Conservation of Nature (IUCN) "Red List" because of fishing‐related interactions (Otway, Bradshaw, & Harcourt, et al., [2004](#vms3272-bib-0016){ref-type="ref"}; Otway, [2015](#vms3272-bib-0015){ref-type="ref"}). More recently, research on the "critically endangered" grey nurse shark population off eastern Australia has enabled the collection of blood samples via the CV from free‐living individuals providing important data for husbandry and veterinary care (Otway, [2015](#vms3272-bib-0015){ref-type="ref"}). This ongoing research also provided an opportunity to assess the efficacy of an alternative venipuncture site provided by the paired lateral abdominal veins (LAV).

The paired LAV originate in the cloacal region and run cranially from the pelvic to pectoral fins along the lateroventral muscle mass adjacent to the peritoneum (Muñoz‐Chápuli, [1999](#vms3272-bib-0012){ref-type="ref"}; Satchell, [1999](#vms3272-bib-0018){ref-type="ref"}). Blood‐flow in the paired LAV is driven by the ventricular ejection of blood from the heart (Satchell, [1999](#vms3272-bib-0018){ref-type="ref"}) and produces flows that are not greatly affected by inactivity or restraint. The precise location of the paired LAV cannot be easily identified using external morphological features and venipuncture requires ultrasound guidance. With this in mind, an assessment of the LAV was done by integrating the results of morphometric measurements, necropsies, ultrasound‐guided blood sampling and by comparing the serum biochemistry obtained from the LAV with those obtained previously from the CV by Otway ([2015](#vms3272-bib-0015){ref-type="ref"}).

2. MATERIALS AND METHODS {#vms3272-sec-0002}
========================

2.1. Necropsies {#vms3272-sec-0003}
---------------

As part of a multi‐disciplinary threatened species recovery program, 190 grey nurse sharks from the wild population of eastern Australia have been subjected to necropsy following their incidental capture in shark nets protecting swimmers at beaches and by commercial and/or recreational fishers. However, quantitative necropsy data for this study were only taken from 64 sharks with no evidence of previous fishing interactions (e.g., hook retention in the gastrointestinal tract) prior to their death. These individuals comprised neonates to sexually mature individuals of both sexes and the necropsies were used to confirm the location of the paired LAV and CV, their anatomy and surrounding tissues/organs. The total length (TL) with caudal fin in a depressed position (Francis, [2006](#vms3272-bib-0006){ref-type="ref"}) and total weight (TW) were recorded to the nearest mm and kg, respectively, for sharks ranging 1000--3050 mm TL. Fifty additional measurements including the pre‐caudal length (PCL); pectoral‐pelvic space---the straight‐line length between the pectoral fin insertion and the pelvic fin origin (PPS); the girth at the cranial edge of the pre‐caudal pit (G~PCP~) and the anal‐caudal space---the straight‐line length between the anal fin insertion and the origin of lower lobe of the caudal fin (ACS) were also taken and plotted against TL.

The ultrasonographic depth of focus to the LAV and length of needle required were identified by quantifying the mean tissue thickness (MTT) overlying each LAV and the mean internal diameter (MID) of the paired LAV. Both variables were measured to the nearest 0.1 mm using digital photographs of transverse sections with a 30 mm scale bar (Figure [1](#vms3272-fig-0001){ref-type="fig"}) at four equidistant positions along the paired LAV and measurement software (GRAB IT XP, Datatrend Software).

![Photograph of transverse section of the abdominal wall of a grey nurse shark (*Carcharias taurus*) showing the skin, muscle, lateral abdominal vein and peritoneum](VMS3-6-579-g001){#vms3272-fig-0001}

2.2. Sampling sites, shark capture and blood sampling {#vms3272-sec-0004}
-----------------------------------------------------

To permit comparison of blood samples from the same (reference) population, free‐living grey nurse sharks occupying sand and/or boulder‐filled gutters close to islands and emergent rocky pinnacles (Otway & Ellis, [2011](#vms3272-bib-0017){ref-type="ref"}) were captured from small dive boats (\< 7m) on days with low seas and swell and a minimal sea‐breeze. In addition to the 37 grey nurse sharks (19 males, 18 females) previously sampled by Otway ([2015](#vms3272-bib-0015){ref-type="ref"}), a further 19 (9 males, 10 females) were captured by a team of experienced scuba divers using identical methods that involved placing a lasso around the caudal peduncle of each shark. Following capture, each shark was hauled to the surface, placed in a partially submerged stretcher and rolled into dorsal recumbency to induce tonic immobility (Henningsen, [1994](#vms3272-bib-0009){ref-type="ref"}). Venipuncture was given chronological primacy over the health assessment to reduce the effects of capture stress on serum biochemistry (see Otway, [2015](#vms3272-bib-0015){ref-type="ref"} for details) and blood was collected from every shark captured.

A portable Sonosite TITAN (Sonosite, Sydney, Australia) colour, doppler ultrasound system with a 5--10 MHz, 38 mm linear array transducer (7 cm maximum scan depth) was used for ultrasound guidance. Acoustic coupling gel (Image Gel 200---ATX Medical Solutions, Sydney, Australia) was applied liberally to the shark\'s skin 50--100 mm cranial to the left or right pelvic fin origin (Figure [2](#vms3272-fig-0002){ref-type="fig"}). The ultrasound transducer (orientated transversely) was placed on the coupling gel and a preliminary scan was done to confirm the local anatomy comprising the skin, muscular abdominal wall, the LAV, peritoneum and liver. The portable ultrasound with transducer (orientated longitudinally) along the LAV was then used to guide a disposable syringe with 38 mm, 18 G needle (Terumo) to the LAV.

![Diagram showing location of the lateral abdominal vein in relation to the pectoral and pelvic fins in the grey nurse shark (*Carcharias taurus*)](VMS3-6-579-g002){#vms3272-fig-0002}

2.3. Health assessment {#vms3272-sec-0005}
----------------------

The tripartite health assessment (Otway, [2015](#vms3272-bib-0015){ref-type="ref"}) was done to identify any unhealthy sharks and exclude their sera from analysis in this study. Firstly, the presence/absence of buccal (respiratory) pumping, eye appearance, pupillary reflexes, teeth and gingival appearance, skin colour and gender (via claspers in males) were recorded. Secondly, a detailed physical examination was done in which scars, open wounds, external parasites (and associated lesions), muscle tone, spinal deformities and the presence of hooks in the jaws, gills and buccal cavity were noted. The TL, PCL, PPS and G~PCP~ were then measured to the nearest mm with a flexible measuring tape with the PCL and G~PCP~ each used to estimate TL and TW via the regressions in Table [1](#vms3272-tbl-0001){ref-type="table"}. Lastly, the sexual maturity of each shark was assessed using TL, PPS and the absence of uterine hymen on cloacal palpation in females, and the TL, degree of clasper calcification and clasper length in males (Walker, [2005](#vms3272-bib-0027){ref-type="ref"}). The presence of hooks in the gastrointestinal tract and associated organs was determined using the metal detector and/or ultrasound. Age was then estimated using TL and a von Bertalanfy growth curve. On conclusion, a tissue sample (fin‐clip) was taken and preserved in 95% ethanol for subsequent genetic analysis (e.g. Stow et al., [2006](#vms3272-bib-0021){ref-type="ref"}). The grey nurse shark was then released with its subsequent swimming behaviour monitored for 15 min by scuba divers.

######

Morphometric relationships derived for grey nurse sharks (*Carcharias taurus*) from coastal waters off eastern Australia

  Morphometric relationship                             Units    Regression equation             Regression significance
  ----------------------------------------------------- -------- ------------------------------- ------------------------- ------ --------- --------
  Total weight on Total length                          kg, m    TW = 5.4511(TL^3.1716^)         64                        0.97   1983.6    \<.001
  Total weight on Girth at Precaudal pit                kg, m    TW = 2,514.3(G~PCP~ ^3.9139^)   64                        0.99   9,863.0   \<.001
  Total length on Precaudal length                      m, m     TL = 1.3682(PCL) + 0.0685       64                        0.99   6,459.0   \<.001
  Pectoral‐pelvic space on Total length                 m, m     PPS = 0.224(TL) + 0.601         47                        0.91   520.7     \<.001
  Anal‐caudal space on Total length                     mm, mm   ACS = 0.035(TL) -- 14.618       47                        0.91   526.9     \<.001
  Mean tissue thickness overlying LAV on Total length   mm, mm   MTT = 0.015(TL) -- 14.303       47                        0.90   428.0     \<.001
  Mean internal diameter of LAV on Total length         mm, mm   MID = 0.0046(TL) -- 3.506       47                        0.90   426.8     \<.001

Abbreviations: ACS, anal‐caudal space; G~PCP~, girth at precaudal pit; LAV, lateral abdominal vein; MID, mean internal diameter of LAV; MTT, mean tissue thickness; PCL, precaudal length; PPS, pectoral‐pelvic space; TL, total length; TW, total weight.

John Wiley & Sons, Ltd

2.4. Serum biochemistry {#vms3272-sec-0006}
-----------------------

Following venipuncture, the blood was immediately processed using the methods of Otway ([2015](#vms3272-bib-0015){ref-type="ref"}). Briefly, the blood was placed into a disposable falcon tube without anticoagulant, stored in darkness and on ice until returning to shore. Once ashore and following clotting, the blood was centrifuged at 3,000 *g* for 6 min and then the separated serum was pipetted (1.5 ml) into 3 or 4 replicate capped plastic vials and frozen at −20°C overnight. Thereafter, the sera were transported to the analytical laboratory (IDEXX) and stored at −20°C until analysed (within 3 days). Serum biochemical analytes were quantified via ion selective electrode methods and automated bi‐chromatic spectrophotometry using the same analytical equipment in Otway ([2015](#vms3272-bib-0015){ref-type="ref"}).

2.5. Statistical analyses {#vms3272-sec-0007}
-------------------------

Statistical analyses were done with a nominal Type I (α) error‐rate of *p* = .05 using DATADESK Version 6.0 (Data Description Inc.), POPTOOLS (Hood, 2010) and SIGMA PLOT Version 11.0 (Systat Sofware Inc.). TW was plotted against TL and G~PCP~ with curvilinear regressions fitted and the significance examined using analysis of variance (ANOVA). The PCL, PPS, ACS, MTT and MID were also plotted against TL and the respective lines of best fit was calculated using least‐squares linear regression and their significance was examined using ANOVA. Possible differences in the TL or TW of sharks chosen for sampling the LAV or CV and between the sexes were examined using two‐factor ANOVA following Cochran\'s test for heteroscedasticity and subsequent transformation if required (Underwood, [1997](#vms3272-bib-0026){ref-type="ref"}). The proportions of sharks chosen for blood sampling from the LAV and CV (i.e., venipuncture sites) between the sexes or immature and mature individuals were examined using χ^2^ contingency table analyses. The serum analyte data were examined following standard procedures (Otway, [2015](#vms3272-bib-0015){ref-type="ref"}). Briefly, the raw data for each serum analyte were plotted and examined for outliers using Tukey\'s method (Sokal & Rohlf, [1969](#vms3272-bib-0022){ref-type="ref"}), with an *a priori* emphasis on retaining all but the most extreme outliers in accordance with previous studies (e.g. Geffré et al., [2009](#vms3272-bib-0007){ref-type="ref"}). Shapiro‐Wilk tests were used to examine for normality and unbalanced, 2‐tailed *t*‐tests were used to test the null hypothesis of no difference in mean values between venipuncture sites for each serum analyte.

3. RESULTS {#vms3272-sec-0008}
==========

3.1. Necropsies {#vms3272-sec-0009}
---------------

A subset of the morphometric relationships of direct relevance to this study are summarized in Table [1](#vms3272-tbl-0001){ref-type="table"}. All the linear regressions on TL were significant (*p* \< .001) and accounted for at least 90% of the variation in each dependent variable. The PPS closely approximated the position of each LAV and was used to quantify the length of the LAV accessible for venipuncture. The PPS increased significantly with increasing TL (Table [1](#vms3272-tbl-0001){ref-type="table"}) and the mean (±*SD*) length of each LAV was 22.4 (0.1) % of TL and ranged from 22.2% to 22.7% of TL. The ACS was used to quantify the length of the CV accessible for venipuncture. While the length of the ACS also increased significantly with increasing TL (Table [1](#vms3272-tbl-0001){ref-type="table"}), the mean (±*SD*) length of the CV was only 2.8 (0.2) % of TL and ranged from 2.4% to 3.1% of TL.

The thickness of the tissue overlying each LAV (Figure [1](#vms3272-fig-0001){ref-type="fig"}) did not differ significantly among the four positions (ANOVA, *p* = .39). As expected, the MTT increased significantly with increasing TL (Table [1](#vms3272-tbl-0001){ref-type="table"}) with the mean MTT (±*SD*) ranging from 3.5 (0.6) mm in the smallest shark to 33.8 (3.8) mm in the largest shark. The MID also increased significantly with increasing TL (Table [1](#vms3272-tbl-0001){ref-type="table"}) with the mean MID (±*SD*) ranging from 1.8 (0.2) mm to 11.8 (1.0) mm in the smallest to the largest shark, respectively. Finally, the cross‐sectional area of each LAV was equal to or exceeded that of the CV in any given shark.

3.2. Shark capture, blood sampling and health assessment {#vms3272-sec-0010}
--------------------------------------------------------

When lassoed each grey nurse shark swam away from the scuba diver and stopped when the rope (to the boat) became taut. Thereafter, the shark turned 180°, attempted to bite its own tail and then hung limply upside down while it was hauled to the surface. Once in the stretcher, it was rolled into dorsal recumbency and became cataleptic within a couple of minutes with minimal manual restraint required. This ensured the safety of all persons involved and reduced the shark\'s stress associated with capture and handling.

Ultrasound‐guided blood sampling of the LAV was then easily accomplished with the preliminary scan confirming the local anatomy comprising the skin, muscular abdominal wall, the LAV and peritoneum (Figure [3](#vms3272-fig-0003){ref-type="fig"}). A reverberation artefact, manifest as a mirroring of the skin, was evident in the upper 5 mm of some of the ultrasound images (Figure [4](#vms3272-fig-0004){ref-type="fig"}) but did not affect the continuous visualization of the needle. The penetration of the LAV was distinctly felt and associated with an instantaneous flash of blood in the syringe nozzle. Ultrasound guidance enabled a single, 10‐mL blood sample to be collected with ease from the left or right LAV in each of the free‐living grey nurse sharks.

![Ultrasound image (transverse section) showing abdominal wall of a 2,600 mm TL male grey nurse shark (*Carcharias taurus*) with skin, muscle, lateral abdominal vein and peritoneum. *Note*: Scale to maximum of 3.3 cm is shown vertically on the right‐hand side of the sonogram with increments of 0.5 cm between markers](VMS3-6-579-g003){#vms3272-fig-0003}

![Ultrasound image (longitudinal section) showing abdominal wall of a 2,270 mm TL female grey nurse shark (*Carcharias taurus*) with skin, muscle, needle, lateral abdominal vein and peritoneum. *Note*: Scale to maximum of 2.8 cm is shown vertically on the right‐hand side of the sonogram with increments of 0.5 cm between markers](VMS3-6-579-g004){#vms3272-fig-0004}

Following release, each shark descended to the seabed and rejoined its conspecifics aggregated within a sand or boulder‐filled gutter. Once with the other grey nurse sharks, the released individual resumed its normal swimming behaviour (i.e. 'hovering' and/or 'milling' sensu Smith, Scarpaci, Louden, & Otway et al., [2015](#vms3272-bib-0020){ref-type="ref"}). Moreover, none of the released sharks commenced active buccal pumping (a stress indicator in this species) during the 15‐min monitoring period after blood sampling.

Of the 19 sharks caught for LAV blood sampling, three individuals (one male, two females) with prior fishing‐related injuries were classified as unhealthy using the exclusion criteria of Otway ([2015](#vms3272-bib-0015){ref-type="ref"}) and eliminated from the study. The remaining individuals (eight males, eight females) were then compared with the 30 healthy sharks caught by Otway ([2015](#vms3272-bib-0015){ref-type="ref"}) to identify any significant differences in TL, TW and sexual maturity (Table [2](#vms3272-tbl-0002){ref-type="table"}). The mean TL and TW of the 46 healthy sharks captured for blood sampling from the LAV and CV (Table [2](#vms3272-tbl-0002){ref-type="table"}) did not differ between gender or venipuncture site (ANOVA, *p* = .94 and 0.93, respectively). Similarly, the proportions of immature and sexually mature sharks did not differ significantly between venipuncture site and gender (χ^2^ = 0.05 and 1.39, *p* = .83 and 0.24, respectively).

######

Comparison of the biological attributes of free‐living grey nurse sharks (*Carcharias taurus*) captured in coastal waters off eastern Australia for sampling blood from the lateral abdominal veins and caudal vein

  Venipuncture site        Gender   Number of individuals   Total length (mm)   Total weight (kg)
  ------------------------ -------- ----------------------- ------------------- ------------------- -------------- -------------- --------- ---------
  Lateral abdominal vein   Male     8                       3                   5                   2,199 (519)    1,470--2,650   77 (45)   19--120
  Female                   8        5                       3                   2,236 (447)         1,520--2,720   79 (40)        27--130
  Caudal vein              Male     15                      6                   9                   2,169 (503)    1,470--2,650   74 (43)   19--120
  Female                   15       9                       6                   2,273 (466)         1,520--2,800   84 (42)        27--143

John Wiley & Sons, Ltd

3.3. Serum biochemistry {#vms3272-sec-0011}
-----------------------

There was no haemolysis in the serum samples from the LAV and inspection of the two datasets indicated that there were no outliers present (Tukey\'s method) and the analyte values approximated normal distributions with homogeneous variances (2‐tailed *F*‐tests, all *p* \> .05). Moreover, the low serum CK activities (≤81 IU) indicated that the serum biochemistry analytes were unaffected by capture‐stress (Otway, [2015](#vms3272-bib-0015){ref-type="ref"}). The mean (±*SD*), median and range for each serum analyte sampled from the LAV and CV were then calculated and summarized in Table [3](#vms3272-tbl-0003){ref-type="table"} together with results of unbalanced, 2‐tailed *t*‐tests which showed that none of the serum biochemistry analytes differed significantly between venipuncture sites (all analytes, *p* = .24--0.98).

######

Comparison of serum biochemical analytes sampled from the lateral abdominal vein and caudal vein of free‐living grey nurse sharks (*Carcharias taurus*) from coastal waters off eastern Australia

  Serum analyte              Lateral abdominal vein (LAV, *n* = 16)   Caudal vein (CV, *n* = 30)   LAV versus CV
  -------------------------- ---------------------------------------- ---------------------------- --------------- ----------- ------- -------------- ------ -----
  Sodium (mmol/L)            258.0 (5)                                257.0                        248.0--267.0    258.0 (4)   257.0   248.0--267.0   0.14   .89
  Chloride (mmol/L)          242.0 (8)                                246.0                        228.0--252.0    242.0 (7)   242.0   228.0--254.0   0.03   .98
  Potassium (mmol/L)         4.8 (0.5)                                4.8                          4.2--5.5        5.0 (0.3)   5.0     4.1--5.5       1.19   .24
  Inorganic P (mmol/L)       1.9 (0.1)                                1.8                          1.7--2.0        1.8 (0.1)   1.9     1.7--2.0       0.43   .67
  Total calcium (mmol/L)     3.9 (0.2)                                3.9                          3.5--4.1        3.9 (0.3)   3.9     3.4--4.3       0.10   .92
  Magnesium (mmol/L)         2.0 (0.1)                                1.9                          1.6--2.2        1.9 (0.2)   1.9     1.6--2.2       0.94   .35
  Glucose (mmol/L)           2.7 (0.3)                                2.7                          2.1--3.0        2.7 (0.2)   2.7     2.1--3.1       0.31   .76
  Total protein (g/L)        31.0 (3)                                 30.0                         26.0--36.0      30.0 (3)    30.0    26.0--36.0     0.43   .67
  Urea (mmol/L)              376.0 (8)                                375.0                        365.0--394.0    377.0 (8)   376.0   361.0--394.0   0.19   .92
  Creatinine (μmol/L)        30.0 (8)                                 30.0                         20.0--40.0      32.0 (10)   30.0    20.0--40.0     0.58   .57
  Total bilirubin (μmol/L)   1.6 (0.5)                                2.0                          1.0--2.0        1.5 (0.5)   2.0     1.0--2.0       0.30   .77
  Cholesterol (mmol/L)       1.4 (0.4)                                1.4                          0.7--2.1        1.4 (0.3)   1.4     0.9--2.0       0.20   .84
  Triglyceride (mmol/L)      0.3 (0.1)                                0.3                          0.2--0.4        0.3 (0.1)   0.3     0.2--0.5       0.89   .38
  ALP (U/L)                  21.0 (6)                                 23.0                         10.0--28.0      20.0 (6)    20.0    10.0--28.0     0.78   .44
  ALT (U/L)                  3.0 (1)                                  3.0                          1.0--3.0        3.0 (1)     3.0     1.0--3.0       0.75   .46
  AST (U/L)                  30.0 (10)                                31.0                         15.0--45.0      29.0 (8)    31.0    16.0--43.0     0.51   .61
  CK (U/L)                   38.0 (20)                                33.0                         15.0--81.0      42.0 (18)   41.0    17.0--81.0     0.71   .48

Abbreviations; ALP, alkaline phosphatase; ALT, alanine aminotransferase; AST, aspartate aminotransferase; CK, creatine kinase; P, phosphorus.

John Wiley & Sons, Ltd

4. DISCUSSION {#vms3272-sec-0012}
=============

The necropsies of grey nurse sharks enabled a thorough examination of both blood vessels in neonate to sexually mature individuals of both sexes. The anatomies and morphometric measurements for grey nurse sharks off eastern Australia were similar to those of ragged‐tooth sharks off South Africa (Bass et al., [1975](#vms3272-bib-0003){ref-type="ref"}) permitting greater generalization of the results to individuals from other populations. Compared to the CV, the paired LAV received blood from a much larger capillary bed comprising the cloacal region, pelvic girdle, pelvic fins, segmental muscles of the abdominal wall and pectoral girdle (Muñoz‐Chápuli, [1999](#vms3272-bib-0012){ref-type="ref"}). When combined, the paired LAV were approximately 16 times longer, on average, than the CV. Additionally, the paired LAV had internal diameters that were equal to or exceeded the CV and venous flows in the LAV are greater and unlikely to be affected by inactivity (Satchell, [1999](#vms3272-bib-0018){ref-type="ref"}).

The placement of each shark in dorsal recumbency in a partially submerged stretcher induced catalepsy, reduced the shark\'s capture and handling stress and ensured the safety of all persons involved. The ultrasound‐guided blood sampling of the LAV was easily accomplished without a styletted needle and at minimal risk to the animal. The reverberation artifact was most likely due to the shield‐shaped denticles in the skin of *C. taurus* (Gilligan & Otway, [2011](#vms3272-bib-0008){ref-type="ref"}) but did not affect the visualization of either LAV or the needle. Despite this, the main risk of this procedure is secondary perforation of the LAV with the needle entering the peritoneal cavity. However, three steps can be taken to minimize this risk. First, appropriate restraint of the shark while in dorsal recumbency is necessary to prevent the shark rolling. Second, the MTT overlying each LAV is noted during the preliminary scan. Third, the angle of needle entry under ultrasound guidance is adjusted in relation to the MTT to mitigate secondary perforation of the LAV.

On release, each shark resumed its normal swimming behaviour near the seabed consistent with previous observations at numerous other aggregation sites (Otway, [2015](#vms3272-bib-0015){ref-type="ref"}; Smith et al., 2015) and provided strong evidence that the entire procedure had no long‐term adverse effects on this critically endangered species.

The absence of significant differences in the serum biochemistry analytes between the LAV and CV in free‐living grey nurse sharks clearly indicates that either venipuncture site can be used to obtain representative blood samples. The serum biochemistry analytes were also similar to those obtained from the CV in captive grey nurse (sand tiger) sharks in North American aquaria (Anderson et al., [2012](#vms3272-bib-0002){ref-type="ref"}). These similar results were somewhat expected as the LAV and CV are part of the primary vascular system in sharks (Muñoz‐Chápuli, [1999](#vms3272-bib-0012){ref-type="ref"}; Satchell, [1999](#vms3272-bib-0018){ref-type="ref"}). In contrast, the dorsal fin blood sinus forms part of the secondary vascular system in sharks (Muñoz‐Chápuli, [1999](#vms3272-bib-0012){ref-type="ref"}; Satchell, [1999](#vms3272-bib-0018){ref-type="ref"}) and possible differences between these vascular systems may have contributed to differences in haematocrit and serum analyte values in comparisons with blood drawn from the CV of captive and free‐living sharks in previous studies (Mylniczenko et al., [2006](#vms3272-bib-0013){ref-type="ref"}; Naples et al., [2012](#vms3272-bib-0014){ref-type="ref"}).

Future use of the paired LAV would enable serial blood sampling of captive sharks to be distributed across two long vessels instead of the single, short CV. The paired LAV may also have substantially greater benefits especially when focusing on small sharks or when other procedures are done. For example, the CV has also been used for the infusion of fluids and/or intravenous anaesthesia (e.g. Lécu, Herbert, Coulier, & Murray, [2011](#vms3272-bib-0011){ref-type="ref"}; Smith, [1992](#vms3272-bib-0019){ref-type="ref"}; Stamper, [2004](#vms3272-bib-0023){ref-type="ref"} and references therein). Using the paired LAV would also permit fluid infusion, avoiding possible over‐perfusion of the kidneys, and mitigate issues associated with nephrotoxic drugs.

5. CONCLUSION {#vms3272-sec-0013}
=============

The successful field‐based sampling clearly showed that the entire procedure ensured the safety of all persons involved, had no adverse effects on the sharks and would be easily achieved with captive animals in the sheltered setting of an aquarium. Importantly, the morphometric measurements, necropsies, ultrasound‐guided blood sampling and comparison of serum biochemistry clearly demonstrated that the paired LAV provide an efficacious alternative for venipuncture in grey nurse sharks. With this in mind, aquarium staff responsible for husbandry and veterinary care should take appropriate opportunities (e.g. via necropsies) to familiarize themselves with the paired LAV with a view to their use in the future.

6. Ethics Statement {#vms3272-sec-0014}
===================

The author confirms that the ethical policies of the journal, as noted on the journal\'s author guidelines page, have been adhered to. This study was done under a scientific research permit (Permit No. P01/0059\[A\]) and an Animal Research Authority (99/14 -- Port Stephens) following the Australian Government National Health and Medical Research Council Australian code of practice for the care and use of animals for scientific purposes 8th Edition, 2013.

CONFLICT OF INTEREST {#vms3272-sec-0016}
====================

The author declares that there are no conflicts of interest.

AUTHOR CONTRIBUTION {#vms3272-sec-0017}
===================

Nicholas Mark Otway: Conceptualization; Data curation; Formal analysis; Funding acquisition; Investigation; Methodology; Project administration; Resources; Software; Supervision; Validation; Visualization; Writing‐original draft; Writing‐review & editing.

The author is grateful to colleagues at NSW DPI for their expertise and support. This work would not have been possible without the additional ultrasound training provided by S. Davies (Australian Institute of Ultrasound) and C. Graham (BCF Ultrasound). Commercial fishers, recreational scuba divers and staff from several aquaria contributed to the project in various ways and are thanked for their input. The reviewers are thanked for their constructive comments that improved the paper.


Q:

What is the most effective strategy to defeat a planet?

Inspired by these two questions here and here that contemplate similar issues, I’m now interested in finding the best strategy for defeating (not destroying) another planet.
The year is 2390. Humanity has taken to the stars and achieved interstellar travel. Humans now inhabit eleven planets in four different star systems. While most of these planets required sophisticated and expensive techniques to colonize (too frigid, barren, or hot to otherwise support human life naturally), two planets are beautiful terran-style worlds. One is Earth, and the other is (for the sake of this question) New Earth.
Sadly, diplomatic relations between these two planets have been souring for several decades and recently exploded into all-out war. Unfortunately for Earth, New Earth’s space fleets were much better prepared and have essentially annihilated Earth’s entire space-faring navy. At this point, Earth and its five billion inhabitants are now severely vulnerable, but can certainly continue to build threatening ships and anti-orbital defenses on the ground. As a result, they have not surrendered.
New Earth wants to ensure that Earth’s citizens are unable to pose a present or future threat to its new space empire while minimizing the cost to themselves. What is the best strategy to accomplish this?
Bonus Objectives
The most obvious solution to this problem is to simply start pushing (or dropping) moderately sized asteroids into the atmosphere. This is certainly a quick way to guarantee victory, but violates the following bonus objectives that the New Earth navy is hoping to fulfill with their strategy:

Earth-like planets are rare, so destroying the planet is not an option.
For the same reason, mass-extinction events that make the planet unsuitable for human habitation is not an option.
Massive loss of civilian life should be avoided if possible. It won’t look good on the news at home if millions of innocent people die.
New Earth wants an unconditional surrender from Earth.
Earth’s surrender should happen as quickly as possible to avoid public opinion souring at home.

Useful Information
This may be updated as more information is requested.

Wormhole-based FTL travel exists (hand waived) that allows medium-large ships to travel long distances quickly, but is expensive.
Earth is ruled by a single governing coalition.

A:

There are two main ways to do this that I can see, in addition to what has been suggested already.

You turn things back to the dark ages by destroying modern shipping and infrastructure...or
You take away the sun.

Option #1
As things now stand, any fleet that controls orbit can deny the planet the ability to reach orbit, because a rocket trying to escape gravity has no ability to dodge a missile or laser from space.
The orbital fleet could also put a stop to all long range or slow moving vehicles...planes, trains, and most ships would be a thing of the past.
This would set the planet's economy back many centuries.  If something isn't local, it can no longer be obtained, except by the extremely rich.
The destruction of satellites would mean long range communications are crippled, especially if the endpoints of communication cables under the oceans are destroyed as well. This might be enough to fracture the world government into feuding regional ones, especially for areas that can't feed their people without food imports.  Those areas will be desperate to surrender once they begin to starve.
But the space fleet could also target power plants, power transmission facilities, bridges, important factories, desalination plants, oil pipelines and refineries, mines, irrigation and water supply pipelines, communications and sewer infrastructure, all kinds of things.
With orbital bombing, you could reduce a planet to the dark ages with tiny to medium civilian casualties, depending on how ruthless you wanted to be. Remember, a power plant has civilians in it, but you can just target the power transmission lines and facilities, and black out cities without killing a soul (but far more effort for the fleet).
Similar rules apply for water, communications, and other resources.  It's too easy to hit things from space, and too hard to shoot back at the enemy, especially if Earth's military can't get any power or metal for the ground-based laser that they keep blowing up before it's finished anyway.
Option #2
To be even more oppressive yet impressive the fleet could deploy huge reflective sheets in an orbit identical to Earth's but close to the sun, so they cast huger shadows farther back from the light source.  If Earth doesn't surrender...You block out the sun with these reflective sheets.
No light, no heat, no plants, everything dies without a bullet being fired.  Once Earth surrenders, probably within weeks, you simply rotate the sheets 90 degrees so they don't block any perceptible amount of light and things soon return to normal.

A:

Stuff a bunch of ships with small pieces of scrap, essentially giant pipe bombs, and detonate them in orbit. Assuming ground to space transport is similar to today's technology (chemical rockets) you've effectively blocked a spacecraft from safely achieving orbit, at very little cost.
This has hopefully triggered what is known as Kessler Syndrome (https://en.m.wikipedia.org/wiki/Kessler_syndrome) as depicted in the film Gravity. As a bonus you probably take out the majority of orbital satellites dealing a blow to earth's communication network (furthering your other goals).
If you're more interested in Earth surrendering, given the scenario of space dominance, you can simply set this scenario up without detonating the ships and hold Earth to ransom, merely threatening Earth to surrender or never be able to safely make it into orbit for generations.


Q:

How to calculate percentage for sum of difference of two columns in sql

I have two columns in the same table, that needs to be summed and get the difference and then calculate the percentage?
SELECT sum([BillCount]) - sum([IssueCount]) as [Difference]
FROM Invoice
where [Year] = '2015'

In the above query I got the result for the difference as 244234. Now I need to calculate the percentage by dividing the difference with the actual Billcount 260918.
sample Data:
SELECT sum(BillCount) as bills, sum(IssueCount) as issues
FROM Invoice
where [Year] = '2015'

Result:
    Bills: 260918
    Issues: 16684
    Difference: 244234
    Divide Difference By actual Bills: 244234/260918 = 0.93
    Percentage: 0.93*100 = 93.60
I have used the changed divisor from zero to one. But I am getting the percentage result in many rows, like for each individual billcount. Is there any way that I could get the exact percentage in one row like we calculate in calculator?
Thanks.

A:

Like this?
SELECT sum([BillCount]) - sum([IssueCount]) as [Difference],
    (sum(IssueCount) - sum(BillCount)) / nullif(sum(BillCount), 0) as ptcdiff
FROM Invoice
where [Year] = '2015'

You'll note I changed the order of subtraction. This makes it so that its a negative change rather than a positive change. If you need an absolute. change, you can just throw abs() around the result. You can also bake this into a function if it makes sense to
declare
    @pctOld float = 260918,
    @pctNew float = 16684

select PctDiff = case when @PctNew is null or @PctOld is null then null
                       when @PctNew = null or @PctOld = null then null
                       when @PctNew = 0 and @PctOld = 0 then 0
                       when @PctNew = 0 and @PctOld > 0 then -100.00
                       when @PctNew >= 0 and @PctOld < 0 then null
                       when @PctNew < 0 and @PctOld > 0 then null
                       when @PctOld = 0 then null
                       else ((@PctNew - @PctOld) / abs(@PctOld)) * 100.0
                  end


# Running R on AWS Lambda

You can run the software environment for statistical computing [R](https://www.r-project.org/) in AWS Lambda via [SCAR](https://github.com/grycap/scar) using the [grycap/r-base-lambda](https://hub.docker.com/r/grycap/r-base-lambda/) Docker image, based on the [debian:stretch-slim](https://hub.docker.com/_/debian/) one.

## Usage on AWS Lambda via SCAR

You can run a container out of this image on AWS Lambda via SCAR using the following procedure:

1. Create the Lambda function

```sh
scar init -f scar-r.yaml
```

2. Execute the Lambda function with an script to compile and run R commands

```sh
scar run -f scar-r.yaml -s r-demo.sh
```

The first invocation will take considerably longer than the subsequent ones, where the container will be cached. You can modify the script and perform another `scar run`.

You can also run multiple concurrent invocations of this Lambda function to perform highly-parallel event-driven processing. See the [SCAR Programming Model](https://github.com/grycap/scar/blob/master/README.md#programming-model).

## Appendix. How to create a minimalistic package for R

TL;DR;

R will be installed on a debian:stretch-slim Docker container. The R executable together with the dependent dynamic libraries will be packaged as a compressed file, that later will be deployed in a new container (when building the image in Docker Hub).

### Step-by-step procedure

The installation is inspired on [this one]( https://aws.amazon.com/es/blogs/compute/analyzing-genomics-data-at-scale-using-r-aws-lambda-and-amazon-api-gateway/), with the following changes:

* Adapted to Python 3.
* Debian-based installation.
* Changes in R script to use the R_HOME environment variable.

1. Deploy a Docker container out of the debian:stretch-slim image:

```sh
docker run -ti --name rlang-deb-slim debian:stretch-slim bash
```

2. Install the required packages inside the container

```sh
apt-get install -y python3 gcc gcc  libgfortran3 python3-pip r-base wget liblapack3 zip
````

3. Install virtualenv and the Survival R package

```sh
pip3 install virtualenv
wget https://cran.r-project.org/src/contrib/Archive/survival/survival_2.39-4.tar.gz
R CMD INSTALL survival_2.39-4.tar.gz
```

4. Create a virtualenv and install [rpy2](https://rpy2.bitbucket.io/), to use R from python (not strictly necessary for SCAR).

```sh
cd
virtualenv ~/env && source ~/env/bin/activate
pip3 install rpy2
```

5. Create the package that includes the executable together with the libraries.

You can use `ldd` to find out the dynamic libraries required by the R executable file:

```sh
ldd /usr/lib/R/bin/exec/R
    linux-vdso.so.1 (0x00007ffdd39fc000)
    libR.so => /usr/lib/libR.so (0x00007fe713e62000)
    libgomp.so.1 => /usr/lib/x86_64-linux-gnu/libgomp.so.1 (0x00007fe713c35000)
    libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007fe713a18000)
    libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fe713679000)
    libblas.so.3 => /usr/lib/libblas.so.3 (0x00007fe71340c000)
    libgfortran.so.3 => /usr/lib/x86_64-linux-gnu/libgfortran.so.3 (0x00007fe7130e6000)
    libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007fe712de2000)
    libquadmath.so.0 => /usr/lib/x86_64-linux-gnu/libquadmath.so.0 (0x00007fe712ba3000)
    libreadline.so.7 => /lib/x86_64-linux-gnu/libreadline.so.7 (0x00007fe712956000)
    libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007fe7126e3000)
    liblzma.so.5 => /lib/x86_64-linux-gnu/liblzma.so.5 (0x00007fe7124bd000)
    libbz2.so.1.0 => /lib/x86_64-linux-gnu/libbz2.so.1.0 (0x00007fe7122ad000)
    libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007fe712093000)
    librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007fe711e8b000)
    libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007fe711c87000)
    libicuuc.so.57 => /usr/lib/x86_64-linux-gnu/libicuuc.so.57 (0x00007fe7118df000)
    libicui18n.so.57 => /usr/lib/x86_64-linux-gnu/libicui18n.so.57 (0x00007fe711465000)
    /lib64/ld-linux-x86-64.so.2 (0x00007fe714684000)
    libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007fe71124e000)
    libtinfo.so.5 => /lib/x86_64-linux-gnu/libtinfo.so.5 (0x00007fe711024000)
    libicudata.so.57 => /usr/lib/x86_64-linux-gnu/libicudata.so.57 (0x00007fe70f5a7000)
    libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007fe70f225000)
```

Create a directory for the files and copy R inside:

```sh
mkdir $HOME/lambda && cd $HOME/lambda
cp -Lr /usr/lib/R/* $HOME/lambda/
cp $HOME/lambda/bin/exec/R $HOME/lambda
```

Do not forget the `-L` options in order to follow the symlinks when copying the files.

Copy the required libraries:

```sh
cp  /usr/lib/R/lib/libR.so $HOME/lambda/lib/
cp  /usr/lib/x86_64-linux-gnu/libgomp.so.1 $HOME/lambda/lib
cp  /lib/x86_64-linux-gnu/libpthread.so.0 $HOME/lambda/lib
cp  /usr/lib/libblas.so.3 $HOME/lambda/lib
cp /usr/lib/x86_64-linux-gnu/libgfortran.so.3 $HOME/lambda/lib
cp  /usr/lib/x86_64-linux-gnu/libquadmath.so.0 $HOME/lambda/lib
cp /lib/x86_64-linux-gnu/libreadline.so.7 $HOME/lambda/lib
cp /lib/x86_64-linux-gnu/libpcre.so.3 $HOME/lambda/lib
cp /lib/x86_64-linux-gnu/liblzma.so.5 $HOME/lambda/lib
cp /lib/x86_64-linux-gnu/libbz2.so.1.0 $HOME/lambda/lib
cp /lib/x86_64-linux-gnu/libz.so.1 $HOME/lambda/lib
cp /lib/x86_64-linux-gnu/librt.so.1 $HOME/lambda/lib
cp /lib/x86_64-linux-gnu/libdl.so.2 $HOME/lambda/lib
cp /usr/lib/x86_64-linux-gnu/libicuuc.so.57 $HOME/lambda/lib
cp /usr/lib/x86_64-linux-gnu/libicui18n.so.57 $HOME/lambda/lib
cp /lib/x86_64-linux-gnu/libgcc_s.so.1 $HOME/lambda/lib
cp /lib/x86_64-linux-gnu/libtinfo.so.5 $HOME/lambda/lib
cp /usr/lib/x86_64-linux-gnu/libicudata.so.57 $HOME/lambda/lib
cp /usr/lib/x86_64-linux-gnu/libstdc++.so.6 $HOME/lambda/lib
cp /usr/lib/lapack/liblapack.so.3 $HOME/lambda/lib
```

Add the Python libraries to that folder

```sh
cp -r /root/env/lib/python3.5/site-packages/ $HOME/lambda
```

Modify the `/root/lambda/bin/R` shell-script file so that:

```sh
R_HOME_DIR=$R_HOME
```

This is required in order to later be able to start R from that folder.

6. Create the deployment package

```sh
cd $HOME/lambda
tar czvf /tmp/rlang-debslim.tgz *
```

7. (Optional) Test the application

Once the `rlang-debslim.tgz` file has been decompressed in another machine, you can run the application by defining the appropriate environment variables and then executing R, as follows:

```sh
export R_HOME=$HOME
export LD_LIBRARY_PATH=$HOME/lib
export PATH=$PATH:$HOME/bin
R
```


America and the Demise of Civility

Recently a business man traveling from Dallas to Newark related an incident he had on a previous flight. When he boarded the plane, he was surprised to see a young lady already in his seat. He checked his ticket. It
was his seat. The young woman noticed what he did and smiled in the direction of the little boy and his father seated next to her. The businessman said he understood and was willing to take her assigned seat. She pointed to the seat directly in front of her. Politely the businessman sat down. The seat next to him was empty.

Within a few moments, a rather full-sized woman showed up with the stewardess and a seat-belt extension. She squeezed into the empty seat and tried to make herself comfortable for the flight. The seat truly was too small. It did not take long for the businessman to realize that the young lady in the seat behind him was in no way related to the little boy and man in the same row. She had simply chosen to dupe him for her own convenience.

Not many people would be surprised that this happened. So many ways of acting today indicate that we have lost a sense of obligation to others. We tend to place our needs above those of others, our comfort over theirs. In fact, 52% of passengers and 69% of workers in the travel industry say a decline in values and morality leads people to be less polite and respectful. (cf.
Push Comes to Shove: Passengers and Travel Workers Call Rudeness a Real Problem, The Pew Charitable Trusts, 2003)

Americans encounter more and more impoliteness and lack of respect in their daily lives. People drive with the radio blasting. They mingle in a crowd with their iPods so loud that it’s easier to just sing along. Riding on a train or waiting for a flight at the airport, we are forced to listen to others conduct their business or broadcast the most personal details of their lives on their cell phones. Such loud conversations and noise invade our personal space and rob us of our peace of mind. Good manners are gone!

How many times people come out of the supermarket to their car only to find it attacked by a shopping cart someone else has inconsiderately left in the parking lot. Aggressive drivers, road rage, rude sales clerks, poor customer service: these are but a few examples of a deeper phenomenon. Nearly 80% of Americans bemoan the lack of respect and the demise of courtesy. And almost as many indicate our manners are only getting worse. (cf.
Aggravating Circumstances: A Status Report on Rudeness in America., the Pew Charitable Trusts, 2002)

The break-down in courtesy is most apparent and more insidious in some of our schools. Where the young should be trained in respect for others, in many cases, it simply isn’t happening. In fact, some of our schools have become breeding grounds for lack of respect to others. An estimated 525,000 attacks, shakedowns, and robberies occur in public high schools each month. Each school day, 16,000 crimes are committed on or near school property. Every day about 135,000 students carry guns to school (William Kilpatrick,
Why Johnny Can't Tell Right From Wrong, 1992, p. 14)

Stephen Carter, Professor of Law at Yale University, astutely points to our culture’s deep-seated materialism and individualism as fueling the demise of manners in our society. We seek fulfillment in having more of the best for ourselves. We see ourselves as the center of the world. We demand that we be left free to get whatever we want. (Stephen Carter,
Minding Our Manners, The News Hour with Jim Lehrer Transcript, August 5, 1998)

Hurried and harried Americans only add more stress to their lives by their rude manners. But good manners provide a way to deal with stressful situations. Courtesy makes living together pleasant.

Politeness takes effort. It requires personal sacrifice. It means at times putting someone’s right before our own. At times it means even forgoing our own right for the sake of another. Such attitudes only come about when individuals no longer see themselves as the center of the universe. Good manners, therefore, are born of a sense of the transcendence and responsibility for one’s actions before God. Conversely, the more God and religion are marginalized, the more manners deteriorate.

But the awareness that there is more to life than my needs or the things of this world opens us to the beauty of the other. It helps us to respect each other. To re-inject civility in our society, each of us needs the humility to remember that we are one of many. We live in this world with all our uniqueness as part of a wider community. For many of the ills that come from living in a world with others, a healthy dose of civility is a needed antidote. Only in polite interrelatedness can we achieve happiness. Perhaps it’s time we mind our manners!


I posted this last night on CDMu, but thought it would be worth mentioning here as well, for those hard-line visualists who don’t read both sites.

VJing is an extremely varied art form, but long sets is one thing most visual performers have in common. Whether at a festival, or playing club nights, it’s not uncommon to have a single visualist running the stage for an entire show. Usual gripes about pay-parity with the ear-botherers aside, this is also a quite dangerous situation for your hearing.

I’ve always used the squishy, disposable foam earplugs at gigs, but last year I was convinced to pick up a pair of Etymotics ER-20s.

Not only do they protect the earth from tiny yellow landfill, they protect your hearing, and I’ve found that they seem to make loud gigs sound better.

I've been doing and going to shows almost weekly for over 20 years and I can say that without earplugs I would not have the perfect hearing I still have. Another thing that I always do, even with plugs in, is put my hand up over my ear facing the speakers.

I'm using these for over 4 years now. Since then my hearing didn't get worse (I've got a slight ringing in both ears).

Now I'm not only hearing the music better I also can hear people speak more clearly when I'm in a club. Best of all they are dirt cheap. Also selling under the name Alacin ER-20.

http://andybest.net Andy Best

I use them all the time, I agree with what you say about making loud gigs sound better. I can also hear people speak more clearly with them in too- they're pretty great for the price.

Unfortunately, I only started to use these *after* I got tinnitus (much like ECH3L0N), but the plugs stop it from progressing past the "mild" point

I think that the dangers of loud gigs/clubs should be played up more, since it never even really occured to me that I should be wearing ear plugs before I got Tinnitus (probably quite stupid of me)

@blackwatch I've been tempted by the custom fit- do they get uncomfortable at all? (The ER-20's certainly do after a while)

http://noisepages.com/members/jaymis/ Jaymis Loveday

@Andy: The guy who suggested I get the Etymotics has some custom molded ones. He said that depending on a range of factors, your ear canal can change sizes slightly, so they can feel a bit tight and less comfortable at times.

Apparently they're considerably more comfortable overall though.

ECH3L0N

@Andy Best True! My hearing didn't get worse after I've started using them. Too bad I can't experience total silence ever more like the time I stood in the middle of the desert.

I also think the soundlevels in clubs and on festivals have increased in the last few years.

http://andybest.net Andy Best

@ECH3L0N Definitely. I guess you get used to it though, and at times, the noise can seem like silence. I definitely think sound levels have increased- I got Tinnitus from one single night in a club. I imagine Tinnitus research is going to increase since more people are likely to get it with the noisy society of today.

Here's hoping for high fidelity artificial ears in the future :p

http://www.sin-r8.com Sin-R8

I've always used ear plugs while VJing, but when I switched to Etymotics two years ago, I realized that there were subtle ranges in the music that I was missing before.

Yoo

Got a pair of these before i went to Sonár five or so years ago. They made such a difference to my perception I haven't been without a pair since. I agree with the above posts sound systems have definitely gotten louder (not necessarily better it seems!) more should be made of this as in 10-20 years there are going to be a lot of people with serious hearing problems….

http://myspace.com/vjlambency Lambency

I have some of these and they are great almost forget I am wearing them.

noise1010

As an otologist (and musician), I'm encouraged to see more and more artists using ear protection. It implies that they are serious about their craft and hope to be doing it for as long as possible. If someone thinks EPs aren't 'cool' now, I doubt they will find their future hearing aid much better.

The etymotics (and similar) have a much flatter frequency response, so you don't tend to turn up the higher frequencies as you might with foam plugs – which pass along a bit more of the lower end.


Inpatient and 90-day post-discharge outcomes in elective Medicare spine fusion surgery.
Elective spine surgery is a commonly performed operative procedure, that requires knowledge of risk-adjusted results to improve outcomes and reduce costs. To develop risk-adjusted models to predict the adverse outcomes (AOs) of care during the inpatient and 90-day post-discharge period for spine fusion surgery. To identify the significant risk factors associated with AOs and to develop risk models that measure performance. Hospitals that met minimum criteria of both 20 elective cervical and 20 elective non-cervical spine fusion operations in the 2012-2014 Medicare limited dataset. The risk-adjusted AOs of inpatient deaths, prolonged length-of-stay for the index hospitalization, 90-day post-discharge deaths, and 90-day post-discharge readmissions were dependent variables in predictive risk models. Over 500 candidate risk factors were used for logistic regression models to predict the AOs. Models were then used to predicted risk-adjusted AO rates by hospitals. There were 874 hospitals with a minimum of both 20 cervical and 20 non-cervical spine fusion patients. There were 167,395 total cases. A total of 7,981 (15.9%) of cervical fusion patients and 17,481 (14.9%) of non-cervical fusion patients had one or more AOs for an overall AO rate of 15.2%. A total of 54 hospitals (6.2%) had z-scores that were 2.0 better than predicted with a median risk adjusted AO rate of 9.2%, and 75 hospitals (8.6%) were 2.0 z-scores poorer than predicted with a median risk-adjusted AO rate of 23.2%. Differences among hospitals defines opportunities for care improvement.


When anyone gives back to his or her community - never forgetting where they came from - it's an admirable thing.

Such was the case this past Saturday when Danny Verdun-Wheeler, a former star football player at Thomson High School and the University of Georgia, gave something back to youngsters and teenagers in the town where he grew up - Thomson.

Now with the Washington Redskins, Mr. Verdun-Wheeler helped to put on the Second Annual Danny Verdun-Wheeler Football Camp at Sweetwater Park near Thomson. Like was the case last year, this year's camp was a huge success.

Mr. Verdun-Wheeler forewent working out with the Redskins to return to Athens to complete the necessary assignments in the classroom in order to graduate from UGA in May.

It speaks volumes about his character - for education is one of his main topics of discussion when he returns home and serves as guest speaker at a local school. In speaking to local youngsters, he always stresses the importance of getting an education. He also tells youngsters how important it is to listen to their teachers, their parents and other grown ups.

Mr. Verdun-Wheeler is the perfect example of a great role model - not because of his celebrity status, but because he is a young man who has a good head on his shoulders. When he talks to local kids, they listen. They are attuned to him - seemingly grasping every word he utters from his mouth.

I'm so proud of the man that Mr. Verdun-Wheeler has become. I'm certain that others who know him feel the exact same way, as they should.

It was great to have his celebrity friends join him for the football camp, as well as for the celebrity basketball game that night in the gym of Thomson High School. I had looked forward to covering the event since first hearing about it more than two months ago. I'm glad that it was successful.

I sincerely hope that our local youngsters learned something from the football camp - not just that they can aspire to become star football players like many were at the camp - but that they become special in other ways, too. Most of all, I hope they work hard to aspire to be whatever they want to be.

As Mr. Verdun-Wheeler has always said, dreams can only come true with lots of hard work, determination and self-discipline. Those are the values that he learned from his parents and other family members, as well as from the teachers who taught him within the McDuffie County School System.

I'm proud to call him my friend and wish him only the best during his pro football career in the National Football League.


How are distinctions made between factual reporting, interpretation and distortion ?

Extracts from this document...

Introduction

How are distinctions made between factual reporting, interpretation and distortion ? Society's interpretation of factual reporting on newspapers, magazines, slogans, commercials, speeches and everyday-life conversations can be very different from the actual meaning. This is why interpretation is described to be the particular way in which something is understood or explained. Depending on the purpose of the given messages, the factual reporting can sometimes be distorted , so as to change the truth of the subject. Therefore, the meaning of distortion is a change of facts or ideas so they are no longer correct or true. Factual reporting can be objective, neutral or subjective. Nowadays, these three terms are put into practice very frequently in the different areas of knowledge, such as media, ethics, arts... When the facts are not changed in any way and the outcome reflects the truth and real value of the story, then it is considered to be objective facts. The opposite of this it is subjective factual reporting that happens when the facts are changed in order to give a different idea so as to take people's attention more easily. ...read more.

Middle

Perhaps, one person is able to perceive the message given in the painting, and the emotional state of the artist when the picture was painted, and the other person can reach different conclusions. A more concrete example could be found in the movement of impressionism in arts, which had the characteristic to express the interpretation of objects, situations or scenery which the painter had on the artistic work. This examples emphasises how each individual's interpretation is different form one another. Commercial distortion is very common in today's society. The majority of the population of a country watches television or reads magazines in its leisure time. Through these sources of media, most of the products are advertised in such a way that they sell an idea in order to motivate people to buy the product. For instance, a television commercial of a mobile phone with a certain server, such as Amena*, sells the idea of freedom and commodity instead of selling the product itself. ...read more.

Conclusion

In this example, the factual reporting can be considered to be subjective. These two ways of communicating current issues to the population of a country would be different if the actual facts would be shown and expressed correctly, so as to give real information of the issue and not let misunderstandings take place. This would have to be done by not allowing politicians or the media people use distortion of images, words, or important messages. However, this would not benefit the people making the distortions because the audience would interpret in such ways that could create a loss of sympathisers with the political part and future buyers of the announced product. I believe that most of the messages which people receive are in some way distorted in order to transmit a different idea. This is done to benefit certain people, and to get the best results out of that distortion. The distortions are not always negative, they cam also be positive ( like sometimes in arts). However, these distortions can be interpreted in several ways causing misunderstandings and big arguments that lead to problems. ...read more.

Related AS and A Level Political Philosophy essays

This is because when interpreting and reviewing the constitution and law, the judge's decisions could be biased if they are partisan. This means that some Supreme Court decisions could be questioned and accused of being changed or interpreted when they are not needed to be.

of those who turn to parties for help do so because they lack other options. It is also important to note that the signature method of getting on the ballot provides a potential incentive for parties to strengthen their local organizations and establish support among the electorate, thereby increasing their

Also no big wreck parts from the plane were found. This is a factual reporting as it's based on true facts and it not created by opinions or own thoughts as in an interpretation. Also the moon landing is believed to be a fake.

There seems to be a desire within humans to believe in something larger and greater than that which is visible and physical, something science can never explain. For this reason, science can never replace religion, as it simply does not explain enough.


Comments (23)

My anxiety has always made sleep difficult. I don’t know about you, but the less I sleep the harder it is to sleep when I have time! In the past having the same bedtime and wake up time really helped me (lol not possible now)

Here! I use to have to take Tylenol PM & Zoloft to be able to sleep but I’d still sometimes be up until early AM not being able to shut off my mind. Then when I got pregnant I went off all my meds so my insomnia was even worse. I got diagnosed with PPD (postpartum depression) (postpartum depression) so I’m back on my Zoloft but since baby is here now and I need to be alert to take care of him no more PM for me he only sleeps 3-5 hrs at night before he wakes up for a bottle and I just lay there knowing I should sleep but I can’t. I go back to work October 1 and I know it’s going to suck.

Yep (raises hand). I struggle with anxiety and just can't seem to shut my brain off at night. I am frequently up 2 hr blocks or more at night usually after her middle of the night feeding. Or I wake up nearly hourly to peek over and make sure she's okay. I wish I had some advice to give, I just kind of muscle through and then try to nap during the day when baby does. I find pulling a blanket over my head is comforting and helps muffle the little stirring sounds from baby shifting positions in her bassinet. Or I'll snuggle up next to my husband and find the warmth soothing. I've considered a weighted blanket before but haven't tried it. I've found herbal scented microwaveable rice or corn packs helpful too if I drape it over my neck or shoulders. Good luck, hang in there! Let me know if you find a technique that works!

My anxiety has always made sleep difficult. I don’t know about you, but the...

Last edited
08/28/2018

My anxiety has always made sleep difficult. I don’t know about you, but the less I sleep the harder it is to sleep when I have time! In the past having the same bedtime and wake up time really helped me (lol not possible now)

No advice but I sympathize!

Exactly! And before, I didn't mind being tired because I was only responsible for me... Not another fragile human. Didn't help my Dr told me to lay off caffeine to help with the anxiety. So I'm a tired, anxious, uncaffeinated garbage human.

Here! I use to have to take Tylenol PM & Zoloft to be able to sleep but I...

Posted
08/28/2018

Here! I use to have to take Tylenol PM & Zoloft to be able to sleep but I’d still sometimes be up until early AM not being able to shut off my mind. Then when I got pregnant I went off all my meds so my insomnia was even worse. I got diagnosed with PPD (postpartum depression) so I’m back on my Zoloft but since baby is here now and I need to be alert to take care of him no more PM for me he only sleeps 3-5 hrs at night before he wakes up for a bottle and I just lay there knowing I should sleep but I can’t. I go back to work October 1 and I know it’s going to suck.

Ugh yes. Used to love my unisom sleep. Was so restful. Now I feel like I'm floating through the day. Good luck to you on going back to work. I hope rest finds you.

Yep (raises hand). I struggle with anxiety and just can't seem to shut my...

Posted
08/28/2018

Yep (raises hand). I struggle with anxiety and just can't seem to shut my brain off at night. I am frequently up 2 hr blocks or more at night usually after her middle of the night feeding. Or I wake up nearly hourly to peek over and make sure she's okay. I wish I had some advice to give, I just kind of muscle through and then try to nap during the day when baby does. I find pulling a blanket over my head is comforting and helps muffle the little stirring sounds from baby shifting positions in her bassinet. Or I'll snuggle up next to my husband and find the warmth soothing. I've considered a weighted blanket before but haven't tried it. I've found herbal scented microwaveable rice or corn packs helpful too if I drape it over my neck or shoulders. Good luck, hang in there! Let me know if you find a technique that works!

Ugh, sorry we're in the same trash boat together. It is really no fun. "Sleep when the baby sleeps" bah. I wish. Glad you have a couple of techniques to help comfort you. ❤

I’m starting to get really desperate. I feel like I’m in a constant fog and can’t really think straight. LO (little one) only sleeps for one long stretch -4-6 hours and I get maybe 3 hours sleep (usually less) out of that plus some shorter naps squeezed in.

Does anyone have any natural remedies they recommend?
I’m starting to get ...

Posted
08/28/2018

Does anyone have any natural remedies they recommend?

I’m starting to get really desperate. I feel like I’m in a constant fog and can’t really think straight. LO only sleeps for one long stretch -4-6 hours and I get maybe 3 hours sleep (usually less) out of that plus some shorter naps squeezed in.

I wish nothing natural works for me. My husband always told me to count sheep and I told him where to stick his sheep! He can fall asleep as soon as his head hits the pillow so he has no clue what insomnia is like. It’s weird because I use to need total darkness and quiet but baby needs a sound machine to sleep and I feel like sometimes that helps tune everything out. But other times I’m still staring at the ceiling - I try to make sure to put any electronic devices out of the way because that can make your mind not want to shut off. I wish there was a magic tea for us all to drink.

Yes! I've been on sleeping meds for insomnia for 17 years. A few weeks ago I had to start taking half a pill again so that I could get more than 2 hours of sleep a night. I still don't sleep great, but better than I was. I still sleep very lightly and am alert during night wakings.

Does anyone have any natural remedies they recommend?
I’m starting to get ...

Posted
08/28/2018

Does anyone have any natural remedies they recommend?

I’m starting to get really desperate. I feel like I’m in a constant fog and can’t really think straight. LO only sleeps for one long stretch -4-6 hours and I get maybe 3 hours sleep (usually less) out of that plus some shorter naps squeezed in.

Natural Calm helps me... its magnesium, makes you drowsy when you take 2 tsp or so

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Q:

In java network programming, is there a way to keep the Server side open even when the Client side shuts down?

Suppose that we have a simple Echo client/server pair in Java. As I understand it, once one side of the socket breaks then the whole connection is gone.
But what if I want a Server that can always stay alive, even if the client side dies.  I want to be able to resume a broken connection.
Echo Server :
import java.net.Socket;
import java.net.ServerSocket;

public class EchoServer {

    public static void main(String[] args) throws Exception {

        // create socket
        int port = 4444;
        ServerSocket serverSocket = new ServerSocket(port);
        System.err.println("Started server on port " + port);

        // repeatedly wait for connections, and process
        while (true) {

            // a "blocking" call which waits until a connection is requested
            Socket clientSocket = serverSocket.accept();
            System.err.println("Accepted connection from client");

            // open up IO streams
            In  in  = new In (clientSocket);
            Out out = new Out(clientSocket);

            // waits for data and reads it in until connection dies
            // readLine() blocks until the server receives a new line from client
            String s;
            while ((s = in.readLine()) != null) {
                out.println(s);
            }

            // close IO streams, then socket
            System.err.println("Closing connection with client");
            out.close();
            in.close();
            clientSocket.close();
        }
    }
}

any tips appreciated thanks

A:

What you're missing is the concept of a 'session'.  Think about the position of a server, when some bits arrive 'on the wire'.  What to do with these?  With TCP/IP, there is some information already present on the wire, namely:

src addr
src port
dest addr
dest port
and the message payload itself
and some other stuff (like sequence counters, to ensure 'packets' are not jumbled during transmission)

The operating system of the server uses the src/dest addr/port information to decide if this is 'a conversation which is already in progress' or not.  Mainly it considers the dest port (since the message already made it to the machine itself, through the internet and the firewall) to decide if it is for your Java program listening on the 'dest port'.  However, it uses the entire src-addr/src-port/dest-addr/dest-port to try and deliver the payload to your program in the order the sender sent them (which might not be the order in which they arrived, because of the intervening inter-net).  Notice that a single 'message' might actually be split up into multiple packets.  Your operating system's TCP/IP stack is doing a fair bit of work for you.
However, notice that in order to perform this function on your behalf, the operating system has to devote some amount of resources to 'tracking the state' of the TCP/IP session.  At the very least, for each set of port/addr src/dest, there needs to be a counter of the last well-received 'packet', some buffer space to hold the packets until your program is ready to consume them, and so forth.
Now the question facing the TCP/IP stack implementor is "how long should I 'hang on' to this state for"?  Is 10 seconds enough? 20 minutes?  At some point, after not hearing from the client for a while, the session must 'timeout'.  If there were more packets to send in a sequence, and the client starts sending them again, the server has to be able to say "sorry, you're sending me packet 234 of some previous message, but because I didn't hear from you for a while, I threw out packets 1-233.  Could we start again?".
So in that sense, there's no way to prevent the client from 'disconnecting'.  Sure, you can keep listening on the socket, in case the client recovers and sends some more data.  But you and your client will need a way to 'pick up where we left off'.
In HTTP, that's achieved using a 'session cookie' - a long unique string that the server gave to the client, and the client re-sends with each fresh request (whether it happens over the same TCP-level session or not).  This is an 'application level session' which has a lifetime longer than that of the TCP session.
Since you're writing an application, and it sounds like you have some degree of control over what the client and server get to say to each other (the 'protocol'), you have more options about how you will agree on what is a session, how to deal with things if the client 'goes away' (timeout the session), and how both sides will recover and 'pick up where we left off' (re-establish the session).  Don't forget about authentication will you!
As others have said, it depends a great deal on what you're trying to achieve.

A:

When you want to create a Server and multiple Clients, what we normally do is to create a Thread responsible for the communication between the server and one of the clients, so everytime a client connects to the server, the server will start a new Thread and will give it the corresponding socket.
The code should be something like this:
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;

public class EchoServer {

    public static void main(String[] args) throws Exception {

        ArrayList<ClientHandler> clientHandlersList = new ArrayList<ClientHandler>();

        // create socket
        int port = 4444;
        boolean isOver = false;
        ServerSocket serverSocket = new ServerSocket(port);
        System.err.println("Started server on port " + port);

        // repeatedly wait for connections, and process
        while (!isOver) {

            // a "blocking" call which waits until a connection is requested
            Socket clientSocket = serverSocket.accept();
            System.err.println("Accepted connection from client");

            ClientHandler handler = new ClientHandler(clientSocket);
            handler.start();
            clientHandlersList.add(handler);
        }

        serverSocket.close();
    }
}

And the ClientHandler Class:
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.Socket;

public class ClientHandler extends Thread {

    private Socket socket;
    private ObjectInputStream in;
    private ObjectOutputStream out;
    private boolean disconnect = false;

    public ClientHandler(Socket socket) {
        this.socket = socket;
    }

    @Override
    public void run() {
        try {
            in = new ObjectInputStream(socket.getInputStream());
            out = new ObjectOutputStream(socket.getOutputStream());
            while(!disconnect){
                Object message = readMessage();

                //DO something
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public Object readMessage(){
        try {
            Object obj = in.readObject();
            return obj;

        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        return null;
    }

    public void writeMessage(Object obj){
        try {
            out.writeObject(obj);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public void disconnect(){
        try {
            disconnect = false;
            out.close();
            in.close();
            socket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

A:

As someone pointed out, you can't do this with TCP.
Here is a simple example of a DatagramSocket (UDP) echo server.
package test;

import java.io.*;
import java.net.*;

public class UDPEchoServer {

    public static void main(String[] args) throws IOException
    {
        new ServerThread().start();
    }

    static class ServerThread extends Thread
    {

        protected DatagramSocket socket = null;

        public ServerThread() throws IOException
        {
            this("ServerThread");
        }

        public ServerThread(String name) throws IOException
        {
            super(name);
            socket = new DatagramSocket(4444);

        }

        public void run()
        {
            try {
                while (true) {
                    byte[] buf = new byte[256];

                    // receive data
                    DatagramPacket packet = new DatagramPacket(buf, buf.length);
                    socket.receive(packet);

                    // send back the response to the client at "address" and "port"
                    InetAddress address = packet.getAddress();
                    int port = packet.getPort();
                    packet = new DatagramPacket(buf, buf.length, address, port);
                    socket.send(packet);
                }
            }
            catch (IOException e) {
                e.printStackTrace();
            }
            socket.close();
        }
    }
}

Update: Added test info
You can test it with nc
[gustaf@gustf-air]$ nc -u 127.0.0.1 4444
testing echo server
testing echo server
killing it now
killing it now
^C
[gustaf@gustf-air]$ nc -u 127.0.0.1 4444
now we are back
now we are back


#include "f2c.h"

#ifdef KR_headers
double floor();
double r_int(x) real *x;
#else
#undef abs
#include "math.h"
#ifdef __cplusplus
extern "C" {
#endif
double r_int(real *x)
#endif
{
return( (*x>0) ? floor(*x) : -floor(- *x) );
}
#ifdef __cplusplus
}
#endif