Prophylactic laser peripheral iridotomy and cataract progression.
To determine whether prophylactic laser peripheral iridotomy (LPI) for primary angle closure (PAC) is associated with cataract progression. In 1999, Mongolian volunteers aged>or=50 years were invited to participate in a longitudinal study. Glaucoma was excluded in all participants and 712 of them were selected to undergo a full ophthalmic examination as part of the study protocol. Lenses were graded and PAC diagnosed using international classification systems. In 2005, all traced participants underwent a similar dilated examination. Diagnosis of cataract progression was based on the inter-observer variation +2 standard deviations. The association between LPI at baseline and cataract progression was assessed using chi2-test and logistic regression. Of 712 participants, 158 were diagnosed with occludable angles and treated with LPI. In 2005, 137 participants (19.2%) had died, 315 (315/575=54.8%) were traced, and dilated examination was performed on 276 (48%) of them. Progression of nuclear opacity (NO), cortical, and posterior subcapsular (PSC) opacities were evident in 40 (14.5%, 95% confidence interval (CI)=10.6-19.2%), 89 (32.2%, 95% CI=26.8-38.1%), and 11 participants (4.0%, 95% CI=2.0-7.0%), respectively. Although NO was more likely to progress in those with LPI in a crude analysis (odds ratio (OR)=2.02, 95% CI=1.00-4.11, P=0.05), no evidence of an independent association was detected in multivariate analysis adjusting for age, sex, and baseline Schaffer grading (adjusted OR=1.24, 0.41-3.75, P=0.7). There was no evidence of an association between LPI and progression of PSC or cortical opacities. There is no evidence that prophylactic LPI is independently associated with cataract progression in this study.


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    public function __construct(array $array, $empty)
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        $this->array = $array;
        $this->empty = null;
    }
}


What I meant was, what IF Congress does an about face and decides to make PEC's subject to a waiting period instead of immediate coverage as they promised?

That would be a death sentence for some, because there will be those who are terminally ill who will die in that 6 month waiting period, as they suffer from ineffective low cost alternative treatments while waiting for the coverage to kick in.

That would be an insidious and deliberate way to let people die out and save the administration and the insurance companies money as it's a given that there will be people who will die during that waiting period. That would be outright murder.

What I meant was, what IF Congress does an about face and decides to make PEC's subject to a waiting period instead of immediate coverage as they promised?

That would be a death sentence for some, because there will be those who are terminally ill who will die in that 6 month waiting period, as they suffer from ineffective low cost alternative treatments while waiting for the coverage to kick in.

That would be an insidious and deliberate way to let people die out and save the administration and the insurance companies money as it's a given that there will be people who will die during that waiting period. That would be outright murder.

And again, I hope that helps clear it up.

Thanks for replying. Honestly, thats a big if, i dont see why the would do something like that. You can bet that if this passes and there is something like waiting periods for dying folks you will see a sh** storm of protest.

Logged

There's no worse feeling than that millisecond you're sure you are going to die after leaning your chair back a little too far~ ruminations

What I meant was, what IF Congress does an about face and decides to make PEC's subject to a waiting period instead of immediate coverage as they promised?

That would be a death sentence for some, because there will be those who are terminally ill who will die in that 6 month waiting period, as they suffer from ineffective low cost alternative treatments while waiting for the coverage to kick in.

That would be an insidious and deliberate way to let people die out and save the administration and the insurance companies money as it's a given that there will be people who will die during that waiting period. That would be outright murder.

And again, I hope that helps clear it up.

Thanks for replying. Honestly, thats a big if, i dont see why the would do something like that. You can bet that if this passes and there is something like waiting periods for dying folks you will see a sh** storm of protest.

Sounds about right to me mate.

Think also about the drugs-prostitution thing I mentioned. Suppose there is a huge spike in addiction and HIV-AIDS cases (and more crack addicted babies) Suppose the govt. decides to raise taxes on these things according to the amount of casualties needing treatment., to raise revenue for the costs of treatment. The taxpayers won't be happy about that either. There's some interesting twists in the road coming up with this stuff.

The one point that I think most people make too many assumptions on is what the level of care is/will be in a state-funded system. Of *economic* necessity, it must be minimal. Long wait lists, limited access to facilities, restricted hospital stays and a severely reduced list of approved/funded procedures. The starry-eyed seem to expect that everyone will be getting everything possible. Nope: Everyone will be entitled to a minimum of care, prioritized by the administration. TANSTAAFL.

I can assume it will be like it is in Canada and Europe. There's certainly some problems along these lines over there, but they're vastly, vastly preferable to the problems we have now in the current system. There are Canadians on this thread, I noticed. Do you guys have extremely long wait times and all the other stuff Newt says the US will be looking at under this plan?

I might add, from what I've read, Australia actually does have delays for pre-existing conditions when getting new people on some insurance plans. They have some sort of hybrid system, apparently. However, delays are better than not being able to get it at all. Just my opinion.

I can assume it will be like it is in Canada and Europe. There's certainly some problems along these lines over there, but they're vastly, vastly preferable to the problems we have now in the current system. There are Canadians on this thread, I noticed. Do you guys have extremely long wait times and all the other stuff Newt says the US will be looking at under this plan?

On the one hand, we do have some limitations. You pretty much take the family doctor who's available, and you require a GP's referral to see a specialist. That's where you usually get a long wait. It can take months to get in to see a specialist for something that doesn't require immediate treatment. But a good deal of that is due to the specialists limiting the new patients they see. Once you've had that first visit, it gets quicker. Family doctors can sometimes take a couple of weeks to see, but if you've got an immediate problem, they'll often fit you in. Or for something as simple as renewing a prescription or adjusting a dosage, they'll do it over the phone. And there are always emergency rooms and walk-in clinics.

A big part of the problem with a public system is that people do abuse it. Emergency rooms are full of people who don't belong there, and the wait is often long for anybody who isn't gushing blood.

Another problem is that GPs seem to be handing more cases over to specialists than in the past. Back when we were trying to have kids and getting checked out, I waited six months for a urologist to fondle my bag for five seconds and tell me there's no problem with the plumbing.

Of course, the doctors are overworked, but at the same time, they don't want anybody cutting in on their action. Perfectly qualified foreign-trained doctors keep running up against obstacles in trying to get licenced here. Nurse-practitioners, who could handle a lot of the routine stuff, still aren't being used in any great numbers. And when you ask why, it always comes around to the medical profession throwing up roadblocks.

Now, the other problem we have that might actually be alleviated by an American public system is the doctors who get trained and licenced here, then bugger off to the states for more money.

There is also the the fact that relatively few doctors will choose to practice in rural areas without some big financial incentives.

But these problems are not really with the public nature of the service. If the will was there, we could have immigrant doctors and nurse-practitioners filling in the gaps, and if we didn't have the American private system competing with our public one, that would go a long way right there. The other problem is how our medical schools select their students. My sister, who is a doctor, has mentioned before that the process seems to favour those who are in it for personal gain, and are more likely to head south, or take up a lucrative specialty or stay in large urban areas. There are people who would like nothing better than to be a family doctor in rural Canada, and the system could be weighted more in their favour.

When you get down to it, the only real problem with a public system is that everybody uses it, and many don't think twice about using it. That's not necessarily a bad thing, but it does put a big strain on the system and it contributes to long waits.

On the other hand, more people are getting treatment, and getting it earlier than they would have even with the wait. It does make a difference. I see my doctor when I need to, which isn't often, but still more frequent than it would be if I had to pay directly. I have gone as much as eight years without seeing my dentist, who is not covered by the public system. Even with dental care through work, paying up front and submitting the insurance claim is enough of a pain in the ass to keep me away. The irony there is that I can put more time and money into my car without thinking twice.

Getting away from the pros and cons of healthcare reform, I was watching today where there is discussion of passing a Congressional Resolution of Disapproval against South Carolina Congressman Joe Wilson. Now Wilson has apologized to the President and his outburst was wrong. However some people are taking things too far in trying to gain support. Namely Georgia Congressman Hank Johnson by claiming Wilson's outburst is and endourcement of racism.In an interview, (on CNN) Congressman Johnson makes comments about people thinking that Congressman Wilson's outburst is a green light for ever white supremacist to "don their white hoods" and how Congressman Wilson is the face of this. WTH? Do we really need to play a race card in this? While I disagree with the outburst, I don't see anything proving it as a sign that a racist lynch mob is being formed. It's garbage like this that makes people not want to care when a person actually is the victim of racism.If anything this is just a case when one Congressman should of kept his mouth shut when the President was addressing Congress and another who wants to make a mountain out of a mole hill by injecting race. Obama wasn't heckled because of his race, he was heckled because he's the President and a member of an oppsing political party to his heckler. Maybe Congressman Johnson needs to apologize as well and be given a a Congressional Resonlution of Disapporval for his comments.

Logged

Movie Trivia Fact : O.J. Simpson was considered for the title role in The Terminator, but producers feared he was \"too nice\" to be taken seriously as a cold-blooded killer.
Isn\'t hindsight great.
A person is smart. People are dumb, panicky dangerous animals and you know it. - Agent Kay - Men in Black

People are hypothesizing about the race thing because no president in recent memory has gotten that kind of treatment in congress. They ask themselves, what changed? Well, the president is racially mixed now, and he just got massively disrespected in a very formal setting.

I suspect a lot of people don't think this is some sort of deliberately planned racism - that Joe Wilson thought to himself "a black man can't do this" and then yelled out. It's more like, they think many people subconsciously don't offer the same degree of respect to black people as they do to whites. I think they are right about that, though whether this is the case with Joe Wilson I am not so sure.

People are hypothesizing about the race thing because no president in recent memory has gotten that kind of treatment in congress. They ask themselves, what changed? Well, the president is racially mixed now, and he just got massively disrespected in a very formal setting.

I suspect a lot of people don't think this is some sort of deliberately planned racism - that Joe Wilson thought to himself "a black man can't do this" and then yelled out. It's more like, they think many people subconsciously don't offer the same degree of respect to black people as they do to whites. I think they are right about that, though whether this is the case with Joe Wilson I am not so sure.

Well it's not the first time that a president has had harsh treatment by congress. Bush was booed by democrats during his state of the union speeches(04 and 05 I think).

But since Wilson has apologized they should(as in congress) forget about it and focus on more important things.


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Last week, it was announced that the season-opening football game between the Houston Cougars and the UTSA Roadrunners at the Alamodome had been postponed due to Hurricane Harvey.

Today the two schools announced that the game will not be made up this season. Per UTSA’s release, the two schools will “…work together to reschedule the game for a date in a future year.”

“We appreciate the support and understanding of our fans, and their concern for those who have been impacted by Harvey,” UTSA Associate Vice President/Director of Athletics Lynn Hickey said. “We encourage everyone to consider using their ticket refund to make a donation to hurricane relief and recovery efforts. The devastation in South Central and Southeast Texas is beyond imagination, and as the Roadrunner Family we can make a real difference at this critical time.”

Houston and UTSA do not share an open date during the 2017 season. Other dates, even with the help of several schools, were likely not possible due to previously scheduled events at the Alamodome.

The last option was to schedule the game for Saturday, Dec. 2. However, Houston and UTSA would not be able to play that date if one or both schools qualified for their respective conference championship games.

The 2017 Houston-UTSA matchup was part of a four-game, home-and-home series. The two schools are scheduled to meet on Sept. 3, 2022 and Aug. 31, 2024 at TDECU Stadium in Houston and on Sept. 2, 2023 at the Alamodome.


OSEN via Naver1. [+3,921, -82] He makes all that on his own ㅋㅋㅋ2. [+3,182, -135] He's making bank in royalties off of his talent in making good music3. [+2,723, -120] I wish he was my dongsaeng...4. [+2,278, -580] What a good career it must be to be a celebrity ㅋㅋㅋ5. [+502, -17] That income estimate was from 2012... and since then, he's released a solo and a new Big Bang album so I'm sure it's much higher now ㅋ Amazing6. [+479, -22] He's making what he earns but it's such a large amount that I'm jealous7. [+439, -21] Wow, he really does make a lot...8. [+411, -14] He could basically make 790 million won just sitting there breathing....1. [+275, -10] His income just exceeds anything you're capable of imagining... would I ever be able to touch that kind of money in my lifetime?2. [+235, -12] Good for him, what am I supposed to make a living out of3. [+184, -9] Ah... f*ck... jealous...4. [+16, -2] That income was estimated in 2012 so... it's probably higher now...5. [+10, -4] So he can basically sit around doing nothing and still make 800 million won... Basically makes as much as owning two 5 floor buildings in Gangnam. Nevermind the income he makes from CFs, concerts, solo albums, world tours... talk about through the roof.


---
abstract: |
    There have been a number of studies dedicated to identification of fossil galaxy groups, arguably groups with a relatively old formation epoch. Most of such studies identify fossil groups, primarily based on a large luminosity gap, which is the magnitude gap between the two most luminous galaxies in the group. Studies of these types of groups in the millennium cosmological simulations show that, although they have accumulated a significant fraction of their mass, relatively earlier than groups with a small luminosity gap, this parameter alone is not highly efficient in fully discriminating between the “old” and “young” galaxy groups, a label assigned based on halo mass accumulation history.

    We study galaxies drawn from the semi-analytic models of [@Guo11], based on the Millennium Simulation. We establish a set of four observationally measurable parameters which can be used in combination, to identify a subset of galaxy groups which are old, with a very high probability. We thus argue that a sample of fossil groups selected based on luminosity gap will result in a contaminated sample of old galaxy groups. By adding constraints on the luminosity of the brightest galaxy, and its offset from the group luminosity centroid, we can considerably improve the age-dating.
author:
- |
    Mojtaba Raouf $^{1}$[^1], Habib G. Khosroshahi$^{1}$, Trevor J. Ponman$^{3}$, Ali A. Dariush$^{2}$, Alireza Molaeinezhad $^{1}$, Saeed Tavasoli$^{1}$\
    $^{1}$School of Astronomy, Institute for Research in Fundamental Sciences (IPM), Tehran, 19395-5746, Iran\
    $^{2}$Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK\
    $^{3}$School of Physics and Astronomy, University of Birmingham, Birmingham, B152TT, UK
date: 'Accepted 2014 May 10. Received 2014 May 10; in original form 2014 January 15'
title: 'Ultimate age-dating method for galaxy groups; clues from the Millennium Simulations'
---

\[firstpage\]

galaxies: groups : general – galaxies groups: evolution – groups: old or young– galaxies: structure

Introduction
============

The age determination for galaxy systems in the hierarchical structure formation is not trivial because, in this paradigm, more massive galaxy systems such as galaxy clusters are formed through the mergers of smaller galaxy systems and are thus generally young galaxy systems. A galaxy group, however, can be recently formed or forming while some could be relatively old if they have not being subject to a substantial merging with other galaxy systems. In fact the answer to the question of age determination should come from the the cosmological simulations where evolutionary history of galaxy systems can be studied. The cosmological dark matter simulations and the implemented semi-analytic galaxy models offer tools, needed to develop an insight into this subject.

![image](E_deltam14_12_3.eps){width="70.00000%"}

Before these robust simulations became available in cosmological scales, an observational method for identification of old galaxy groups was developed in a pioneering study by [@Ponman1994]. This was motivated by earlier numerical simulations suggesting that in most cases, members of compact galaxy groups could merge to form a single elliptical galaxy in a few billion years [@Barnes1989]. An elliptical galaxy formed by the merger of such a group retains its X-ray emitting halo of hot gas, which is unaffected by merging [@Ponman1994]. Such groups were called fossil groups in which the essential observational tracer has been identified as the large luminosity gap between the two brightest group members.

According to the convention introduced by @Jones2003 fossil groups have a magnitude gap of at least 2 magnitude within 0.5 virial radius and $L_{X,bol}\approx 10^{42} $ h$_{50}^{-2}$  erg s$^{-1}$. Since then there have been many studies focused on the detailed characterisation and properties of fossil groups [@Khosroshahi2004a; @Sun2004; @Ulmer2005; @Khosroshahi2006], based on X-ray and optical observations. However, due to limited number of adequate X-ray surveys and their suitability, most studies selected the magnitude gap as the fossil identifier in theoretical and observational studies [@Yoshioka2004; @Milosavljevic2006; @VandenBosch2007], hydrodynamic simulations [@DOnghia2005], dark matter simulations [@VonBenda-Beckmann2008; @Cui2011] and combined with semi-analytical models for galaxies [@Sales2007; @Diaz2008; @Dariush2010]. @Khosroshahi2007 show that for a given optical luminosity, fossil groups are not only more X-ray luminous than the general population of galaxy groups, but also they have a more concentrated halo as well as hotter IGM for a given halo mass. The study of scaling laws of fossil groups also show that they mostly follow the trend of galaxy clusters which is likely to be driven by their dynamical relaxed state, although @Voevodkin2010 have shown that in the cluster regime there are no noticeable difference between the X-ray luminosity of the fossils and non-fossils for a given optical luminosity. In addition, some other studies support the same conclusion employing other cluster samples [@Aguerri2011; @Harrison2012; @Girardi2014].

One of the largest cosmological simulations, the Millennium Simulation [@Springel2005] joined with Semi-Analytical Models (SAMs) for galaxy formation, provide a useful tool to address open questions, regarding the age determination of the galaxy systems. @Dariush2007 show that the luminosity gap is a fairly good indicator of the halo mass assembly, such that in galaxy groups with a large luminosity gap ($\Delta m_{12}\ge2$), the halos accumulate 50 per cent of their mass at current epoch by $z=1$ and thus are relatively older than their counterparts with small luminosity gap. @Dariush2010 introduce an alternative optical criterion $\Delta$m$_{14} \geq 2.5$, i.e. the luminosity gap between the first and fourth brightest galaxies within $0.5R_{200}$, which is found to be more efficient in identifying early-formed groups than the conventional criterion, $\Delta$m$_{12} \geq 2.0$.

Following the discovery of the fossils groups with different masses, from surveys or serendipitous observations, there has been attempts to study and compare various halo, IGM and galaxy properties of fossil and non-fossil groups [@Khosroshahi2007; @Dupke2010; @Miller2012]. The velocity dispersion of the member galaxies in groups [@Herbst2012; @Madrid2013], the globular cluster distribution and colour [@Alamo2012], the galaxy luminosity function [@Cypriano2006; @Lieder2013], the AGN activities of the groups [@Hess2012; @Miraghaee2013], merger history [@Eigenthaler2013; @Diaz2008] and halo concentration [@Khosroshahi2007; @Deason2013] are amongst these properties. The basic argument upon which these studies are based, is the early formation of fossils groups. The older age of fossil group has been argued in the earlier studies [@Ponman1994; @Jones2003] and demonstrated in the cosmological simulations [@DOnghia2005; @Dariush2007]. However there is still room to develop age dating algorithms with a high efficiency using measurable parameters accessible from routine optical observations and other convenient methods.

In this paper, we first show the extend at which the large luminosity gap can discriminate old and the young galaxy groups. We then introduce a some parameters in which the old and young galaxy groups can be identified more distinctively. We finally define a parameter space which consists of optically measurable parameters of group galaxies, that allow age-dating with a very high efficiency.

Section 2 describes Millennium Simulation and Semi-Analytical Model. In section 3 we describe our multi-parameter analysis to search for old and young groups using the optical measurements. Finally in section 4 present summery of our result and given our conclusion.

The simulation
==============

In this study we use the public release of the Millennium Simulation(Hereafter: MS) [@Springel2005]. The cosmological model adopted in simulation is a $\Lambda$CDM with the following parameters: ${\Omega}_m=0.25$, ${\Omega}_b=0.045$, ${\Omega}_{\Lambda}=0.75$, h=0.73, n=1,${\sigma}_8=0.9$ (note that the value of ${\sigma}_8$ is assumed to be greater than its present value of 0.82 given by WMAP9 that is not strongly affects in this study). The simulation box $(500 h^{-1} Mpc)^{3}$ contains $2160^{3}$ particles and presents the mass resolution of 8.6${\times}$ 10$^8$  h$^{-1}$ M$_{\odot}$.

![image](Concentration.eps){width="95.00000%"}

The dark matter merger trees within each simulation snapshot (64 snapshots) are expanded approximately logarithmically in time between $z=127$ and $z=0$ and extracted from the simulation using a combination of friends-of-friends (FoF) [@Davis1985] and SUBFIND [@Springel2001] halo finders algorithm. The gas and stellar components of galaxies in dark matter halos are constructed semi-analytically, based on differ in the phenomenological recipes.

For galaxy properties, we use @Guo11 semi-analytical model, in which the treatments of many of the physical processes have been improved in comparison to an earlier model by [@DeLucia2007]. This model provides good fits to the observed luminosity and stellar mass functions of galaxies, from the SDSS data and recent determinations of the abundance of satellite galaxies around the Milky Way and the clustering properties of galaxies as a function of stellar mass, as well. Data available in the Millennium database [@Lemson2006], contains $\sim 51000$ halos with masses above 10$^{13}$  h$^{-1}$ M$_{\odot}$ and $\sim5$ million galaxies from which we only select galaxies brighter than $-14$ in r-band absolute magnitude for completeness.

Analysis and results
====================

Age-dating based on luminosity gap
----------------------------------

### $\Delta$m$_{12}$

As mentioned earlier, the magnitude gap between the brightest and second brightest galaxies in a galaxy group, is often used as an indicator of the dynamical age of groups of galaxy. @Dariush2010 investigated the assembly of groups and clusters of galaxies using the Millennium dark matter simulation and semi-analytic catalogues of galaxies. The study aimed at verifying the argument that galaxy groups with a large magnitude gap are formed earlier than the galaxy groups with a small magnitude gap. They used mass accumulation of the group halo as a proxy for early/late halo formation. They selected galaxy groups and clusters at the present time with dark matter halo mass $M(R_{200}) > 10^{13}h^{-1}M_{\odot}$, and trace their properties to $z\simeq1$. In addition they applied an X-ray luminosity criteria to keep those galaxy systems for which the X-ray luminosity $L_{X,bol} > 0.25 \times 10^{42}h^{-2} erg s^{-1}$ at redshift $z=0$. They argued that while it is true that a large magnitude gap between the two brightest galaxies of a particular group often indicates that a large fraction of its mass was assembled at an early epoch, it is not a necessary condition. More than 90% of fossil groups defined on the basis of their magnitude gaps (at any epoch between $0 < z < 1$ ) cease to be fossils within 4 Gyr, mostly because other massive galaxies are assembled within their cores, even though most of the mass in their haloes might have been assembled at early times.\
As a definition here [and @Dariush2007], a galaxy group which formed more than 50 per cent of its total mass by $z\approx1$ is labled as old. A group is labelled young if less than 30 per cent of its final mass is formed by $z\approx1$. In Figure \[Deltam12\_14\] top panel, we present the luminosity gap $\Delta$m$_{12}$ (within 0.5R$_{200}$) as a function of the Brightest Group Galaxy (BGG) magnitude in r-band, $M_r(BGG)$, given for all 39132 groups (i.e. groups with $M(R_{200}) \geq $ 10$^{13}$ h$^{-1}$M$_\odot$ and exist within both $z=0$ and $z=1$ ) using @Guo11 SAM at the present epoch$(z=0)$. The groups are colour-coded according to their $\alpha_{0,1}$ parameters(defined as “age” of systems), where $\alpha_{0,1} = M_{z\approx1}/M_{z=0}$. The horizontal line subdivides groups into magnitude gap bins. Those with $\Delta$m$_{12}\geq2$ are conventional fossil groups. Groups with $\Delta$m$_{12}\leq0.5$ are labelled as control groups which known to be young galaxy groups [@Dariush2007; @Dariush2010]. Vertical lines bin the groups according to the luminosity of their brightest galaxy (BGG) in 4 magnitude bins from -20.5 to -24.5. We note that the systems with large magnitude gap and faint BGGs are modest galaxies with some dwarf satellites, similar to the Milky Way. As these systems do not present galaxy groups, satisfying fossil groups condition, we limit our analysis to BGGs which are at least as bright as $M_{R} < -21.5$, i.e giant galaxies. This diagram shows that the galaxy luminosity gap combined with the luminosity of the brightest group galaxy for all halo mass over $10^{13} M_{\odot} h^{-1}$ is success to identify old groups with a probability of 61 per cent and young galaxy group with a probability of 92 per cent.

### $\Delta$m$_{14}$

The assembly time of a dark matter halo defined as the look-back time when its main progenitor reaches a mass that is more than 50 per cent of the present halo mass. @Dariush2010 showed that the alternative optical criterion $\Delta$m$_{14} \geq 2.5$ (in the R-band, within $0.5R_{200}$ of the centre of the group) is more efficient in identifying early-formed groups than the conventional criterion $\Delta$m$_{12} \geq 2.0$ and it is more success to identify at least 50% more early-formed groups. However, the conventional criterion ($\Delta$m$_{12} \geq 2.0$) performs marginally better at finding early-formed groups at the high-mass end of groups. Figure \[Deltam12\_14\] Bottom panel shows distribution of luminosity gap $\Delta$m$_{14}$ within $0.5R_{200}$ combined with the Brightest Galaxy Group (BGG) magnitude in r-band. In this diagram panels (5), (9) and (10) contain mostly old systems while the panels (3), (4) and (8) are mostly occupied by young systems. The mentioned panels can identify old groups with a probability of at most 74 per cent and young galaxy group with a probability, up to 88 per cent.

![image](decentring.eps){width="95.00000%"}

Other age indicators
--------------------

### Halo concentration

It has been shown that the halo concentration is linked to the epoch of the halo formation [@Wechsler2002]. There are different ways to estimate halo concentration in the literature. A popular method is by fitting a NFW [@NFW96] profile shows in eq. \[NFW\_profile\] to the halo density distribution $$\rho_{NFW}=\frac{\rho_s}{x(1+x)^{2}}
\label{NFW_profile}$$

where $x\equiv r/r_{s}$ and $\rho_s$ and $r_{s}$ are the characteristic density and radius. Then the halo concentration($C_{200}$) is found as eq.\[concentration\] $$C_{200} = \frac{R_{200}}{r_{s}}
 \label{concentration}$$ where $C_{200}$ is the ratio of $R_{200}$ as enclosing a mean density of 200 times the critical rather than the cosmological mean density to the characteristic radius $r_{s}$.

Considering the relation between halo mass and concentration, lower mass halos universally form at earlier epochs relative to higher mass halos [@Gao2008; @Prada2012]. Therefore, the lower mass halos must be more concentrated [@Wechsler2002]. Due to this close connection between halo concentration and assembly history; group halos that formed most of their halo mass at early times are also more concentrated in comparison to the halos with later formation epoch [@Deason2013]. Observationally, for a given optical luminosity, fossil groups have more concentrated halos as well as hotter IGM for a given halo mass [@Khosroshahi2007].

Using the Millennium simulations, @Ludlow2012 demonstrated that, the virial-to-half mass radius, $R_{200}/r_{h}$ in which $r_h$ is the half-mass radius, is a reliable tracer for the halo concentration. We thus estimate the halo concentration as the ratio between the $R_{200}$ and half-mass radius for all candidates for old and young systems. As expected, in Figure \[c\_fig\], the halos of early formed groups show higher concentration compared to the same in late formed groups. While the bimodal distribution of the halo concentration between the old and the young groups (Figure \[c\_fig\]) appears to be very attractive for discriminating these two type of groups, there are significant observational limitations.

Observationally, the halo concentration can be obtained from any observations that can provide halo profile measurement, such as the the X-ray observations of the hot gas, strong/weak gravitational lensing and galaxy distribution within the group/cluster halo.

The X-ray method of measuring the halo mass/density profile is built upon the hydrostatic equilibrium assumption where the gravitational contraction is balanced by the hot gas pressure. This requires measurements of the gas density and the temperature profile which can be obtained from X-ray observations. In practice, additional assumptions are made, such as the spherical symmetry [@Khosroshahi2004a; @Humphrey2006] to obtain the halo mass/density profile [@Fabricant1984; @Pratt2005; @Khosroshahi2006a]. Usually a NFW profile (eq. \[NFW\_profile\]) is fitted to the total gravitational mass density which results in the halo concentration parameter according to eq. \[concentration\].

The gravitational lensing method of mass profile reconstruction, is based on the observations of strong arc shaped features of a distant background source [@Fort1994] or the observation of lens induced shear on the shape of the source galaxies by a lens galaxy cluster [@Miralda1991; @Kaiser1993; @Wilson2001]. These methods are observationally demanding, requiring high quality photometric and spectroscopic measurements, and can only provide a projected mass density for the lensing cluster [see @Leauthaud2007; @Leauthaud2010]. In particular the case of galaxy groups is challenging due to a low lensing signal and stacking of groups may be necessary [@Hoe01]. The lensing method of halo mass measurement is only efficient in intermediate redshift range [@Smith2005; @Oguri2010], while there are many sources of systematic errors in weak lensing [@Mandelbaum2005; @Johnston2007].

There are a limited number of observations which can provide halo concentration of galaxy groups and clusters with a reasonable uncertainty. One of the largest samples of galaxy clusters, studied as part of the LoCuSS project [@Smith2010], points at limited statistics on galaxy clusters for which the halo concentration is measured and also a typically 20 per cent uncertainty in X-ray measurements of the halo concentration, $C_{500}$ [@Sanderson2009]. Similarly, [@Khosroshahi2006a] in the study of fossil galaxy cluster reported a large uncertainty in the concentration, as high as $\sim 40 $ per cent. Thus, halo concentration measurements obtained from gravitational lensing and/or X-ray observations may be subject to large uncertainties [@Mandelbaum2005; @Mandelbaum2006a; @Mandelbaum2006b; @Johnston2007; @Oguri2010; @Shan2010a; @Shan2010b].

![ The relation between total optical luminosity within $R_{200}$ for each semi-analytic group and its halo mass. The red dashed line, fitted to the data, implies that masses of $10^{13}h^{-1}M_{\odot}$, $10^{13.5}h^{-1}M_{\odot}$ correspond to total luminosities of $1.9\times 10^{10}h^{-2}L_{\odot}$, $20.27\times 10^{10}h^{-2}L_{\odot}$, $57.2\times 10^{10}h^{-2}L_{\odot}$, respectively.[]{data-label="lum_mass"}](lum_mass_nonlog_1.eps){width="55.00000%"}

![image](plot_old_young_meanxyz3.eps){width="60.00000%"}

### Luminosity de-centring

Typically, galaxy formation models assume that the brightest group galaxy is located at the centre of group halos, however, [@Skibba2011] demonstrated that the BGG may not always be the central galaxy. In fact, merging systems are dynamically unrelaxed which can result in a significant separation between the brightest galaxy and the halo centre. This quantity has been used as a tracer of the dynamical age of the galaxy groups. For instance, @Rasmussen2012 in a study of ongoing star formation of groups, use the separation of the brightest group galaxy from the luminosity centroid of member galaxies in the group as an age indicator for the galaxy groups. The X-ray emission peak, or the centroid, and the mass centroid from the gravitational lensing observations, have also been used as indicators of the halo centre [@Dietrich2012; @Oguri2010].

One of the interesting properties of the fossil groups is revealed by their X-ray morphology. The X-ray peak coincides very well with the centre of the dominant giant elliptical galaxy [@Khosroshahi2007]. Relaxed morphology of the clusters or absence of substructures are good indicators of the dynamical state of the galaxy systems [@Smith2005]. @Smith2010 shows that clusters with dominant galaxy at the centre are the one with least substructure and are thus dynamically old.

In the absence of X-ray or lensing mass maps, one can resort to optical luminosity distribution. We thus define the luminosity weight of each groups as $X_{L}= \sum X_{i} L_{i}/ \sum L_{i}$, where $L_{i}$ is the luminosity of galaxy in group in r-band and $X_{i}$ is the projected coordinate of each galaxy. The de-centring parameter is thus defined as the projected physical separation between the luminosity centroid of the group and the location of the BGG. As shown in Figure \[dec\_fig\] younger systems show larger separation between BGG and the luminosity centroid of the galaxies in comparison to the old groups. This parameter can also be replaced with the separation between the BGG and other halo centroid indicators such as the one obtained from gravitational lensing and/or X-ray observations, however, our choice has the advantage of being optically measurable.

  -------------------------------- ------------------- ------------------ ------------------- ------------------------ -------------------------
          Group luminosity          $log(Separation)$   $\Delta$m$_{12}$      $M_r(BGG)$       probability(old/young)   $\frac{M_{200}}{L_{r}}$
   $ [10^{10} h^{-2}L_{\odot}]  $        \[Mpc\]            \[mag\]             \[mag\]             \[per cent\]          \[Ratio$\pm\sigma]$
         1.9$\le L < $20.27          $-$2.5 – $-$2.0       4.0 – 4.5       $-$21.5 – $-$22.5          100% old              223.2$\pm$53.0
         1.9$\le L < $20.27          $-$2.5 – $-$2.0       3.0 – 3.5       $-$21.5 – $-$22.5          96% old               217.2$\pm$45.0
         1.9$\le L < $20.27          $-$1.5 – $-$1.0       3.5 – 4.0       $-$21.5 – $-$22.5          90% old                178$\pm$34.4
         1.9$\le L < $20.27          $-$2.0 – $-$1.5       3.5 – 4.0       $-$21.5 – $-$22.5          88% old                222$\pm$57.4
         1.9$\le L < $20.27          $-$2.5 – $-$2.0       2.0 – 2.5       $-$21.5 – $-$22.5          86% old               214.7$\pm$51.0
         1.9$\le L < $20.27          $-$2.0 – $-$1.5       3.0 – 3.5       $-$21.5 – $-$22.5          86% old               219.3$\pm$51.0
         1.9$\le L < $20.27          $-$2.5 – $-$2.0       2.5 – 3.0       $-$21.5 – $-$22.5          85% old                209$\pm$39.0
         1.9$\le L < $20.27          $-$2.0 – $-$1.5       2.0 – 2.5       $-$21.5 – $-$22.5          84% old                206$\pm$49.0
         1.9$\le L < $20.27          $-$2.0 – $-$1.5       2.5 – 3.0       $-$21.5 – $-$22.5          83% old                213$\pm$45.0
         1.9$\le L < $20.27          $-$2.5 – $-$2.0       1.5 – 2.0       $-$21.5 – $-$22.5          80% old                206$\pm$44.0
        20.27$\le L < $57.2          $-$1.5 – $-$1.0       2.5 – 3.0       $-$22.5 – $-$23.5          53% old                181$\pm$49.8
        20.27$\le L < $57.2          $-$2.0 – $-$1.5       2.0 – 2.5       $-$22.5 – $-$23.5          50% old               171.6$\pm$35.7
        20.27$\le L < $57.2          $-$1.5 – $-$1.0       2.0 – 2.5       $-$22.5 – $-$23.5          48% old               176.8$\pm$35.0
        20.27$\le L < $57.2          $-$1.0 – $-$0.5       2.5 – 3.0       $-$22.5 – $-$23.5          47% old                147$\pm$41.2
        20.27$\le L < $57.2          $-$2.0 – $-$1.5       1.5 – 2.0       $-$22.5 – $-$23.5          43% old               183.2$\pm$35.5
        20.27$\le L < $57.2          $-$1.0 – $-$0.5       0.0 – 0.5       $-$22.5 – $-$23.5         58% young              151.3$\pm$ 35.0
        20.27$\le L < $57.2          $-$2.5 – $-$2.0       0.0 – 0.5       $-$21.5 – $-$22.5         56% young               176$\pm$30.0
        20.27$\le L < $57.2          $-$1.0 – $-$0.5       0.0 – 0.5       $-$21.5 – $-$22.5         54% young               150$\pm$35.3
        20.27$\le L < $57.2          $-$1.5 – $-$1.0       0.0 – 0.5       $-$21.5 – $-$22.5         51% young              162.4 $\pm$35.0
        20.27$\le L < $57.2           $-$0.5 – 0.0         3.0 – 3.5       $-$22.5 – $-$23.5         48% young              108.5$\pm$43.7
        20.27$\le L < $57.2           $-$0.5 – 0.0         4.0 – 4.5       $-$21.5 – $-$22.5         43% young              121.5 $\pm$34.0
             $L > $57.2               $-$0.5 – 0.0         0.0 – 0.5       $-$23.5 – $-$24.5         97% young               179$\pm$25.5
            $ L > $57.2              $-$1.0 – $-$0.5       0.5 – 1.0       $-$23.5 – $-$24.5         89% young              186.5$\pm$26.0
            $ L > $57.2              $-$1.5 – $-$1.0       0.0 – 0.5       $-$21.5 – $-$22.5         88% young              176.2$\pm$27.2
            $ L > $57.2               $-$0.5 – 0.0         0.5 – 1.0       $-$23.5 – $-$24.5         87% young              166.1$\pm$31.0
            $ L > $57.2              $-$1.0 – $-$0.5       0.0 – 0.5       $-$21.5 – $-$22.5         77% young              155.7$\pm$33.8
            $ L > $57.2              $-$1.5 – $-$1.0       0.0 – 0.5       $-$23.5 – $-$24.5         76% young               187$\pm$21.5
  -------------------------------- ------------------- ------------------ ------------------- ------------------------ -------------------------

\[tab2\]

Age-dating based on optical observations; A 4-dimensional parameter space
-------------------------------------------------------------------------

Age-dating base on halo concentration and other halo parameters method will rarely be possible to apply in practice, thus we look for a method using only parameters which are commonly available.

A 4-dimensional parameter space can be constructed based upon galaxy properties and using optical observations, only. It has been shown that the total luminosity of a galaxy group is a fair indicator of the halo mass [@Tavasoli2012]. Figure \[lum\_mass\] shows the correlation between groups total luminosity (within $R_{200}$) and halo mass. Using a linear fit to our data we find that the mass ranges of $10^{13}h^{-1}M_{\odot}$, $10^{13.5}h^{-1}M_{\odot}$ and $10^{14}h^{-1}M_{\odot}$ generally correspond to total luminosity ranges of $1.9\times 10^{10}h^{-2}L_{\odot}$, $20.27\times 10^{10}h^{-2}L_{\odot}$, $57.2\times 10^{10}h^{-2}L_{\odot}$, respectively. While the halo concentration is found to be a good age indicator, in this 4-dimensional approach, we assume that only photometric observations of galaxy groups is available. These observations should be such that the two brightest groups members can be identified, for instance through spectroscopic observations. The total luminosity can be estimated through red-sequence fitting or similar methods which allow statistical memberships identifications.

Figure \[plot\_old\_young\] shows the probability for a system to be considered as old (top) and young (bottom) based on the observable 4-dimensional parameter space. The parameter space consists of the total group optical luminosity, luminosity of the BGG, luminosity gap ($\Delta m_{12}$) and luminosity de-centring. In this Figure, size of the symbols (balls) indicate the oldness probability for given sub-region in the parameter space. The luminosity de-centring and the radius at which the magnitude gap, $\Delta m_{12}$, has been estimated are all projected. We note that the $\Delta m_{14}$ improves the statistical probability of old/young groups (Figure \[Deltam12\_14\]), however, we prefer to use $\Delta m_{12}$ due to relative ease of its measurement in spectroscopic surveys. For instance the groups for which the $\Delta m_{14}$ is measured in Sloan Digitized Sky Survey (DR10) accounts for 10% of the groups for which the $\Delta m_{12}$ can be obtained. In addition, $\Delta m_{12}$ has been used widely in the majority of the studies to date.

As an example galaxy groups with a total luminosity of 1.9$\times$10$^{10}$ h$^{-2}$L$_\odot$ through 20.27$\times$ 10$^{10}$ h$^{-2}$L$_\odot$, and $-2\ge log(separation)\ge -2.5$ and M$_r$(BGG)$\approx -22$ mag, with a $\Delta m_{12}\approx 4.5$ are 100 per cent old, according to our definition of age, which is based on mass accumulation history of the halo. As Figure \[plot\_old\_young\] reveals, systems with low total luminosity show the highest population of old galaxy groups. Moreover for a galaxy group to be considered as old, the luminosity gap should be large while the luminosity segregation should be small.

Bottom panel in Figure \[plot\_old\_young\] shows the same probability for young galaxy groups. Largest symbol indicates highest probability of galaxy groups been young. As shown youngest systems are found in high total luminosity galaxy groups where the luminosity gap is small and the luminosity segregation is large.

In Table 2. we report few of the highest probability regions to find old and young galaxy groups; and the average mass-to-light ratio($M_{200}/L_{r}$) for a given region. Statistically, the old group halos have higher mass-to-light ratio relative to the young group halos.

Conclusions
===========

Assigning age to galaxy systems in the Lambda-CDM hierarchical structure formation paradigm is not trivial, but essential, specially when one aims to study the connection between the evolution of the halos to the evolution of galaxies and the properties of the intergalactic medium. We quantify the probability of finding galaxy groups with a given halo mass accumulation history, namely old and young galaxy groups, in the parameter space of the luminosity gap and the BGG luminosity for a given halo mass. We show that there is a limited success in identifying galaxy groups based on the luminosity gap as the statistical probability of finding old groups using this parameter is only $60\%$, in the Millennium simulations (based on [@Guo11] semi-analytic model for the galaxies).

We define a 4-dimensional parameter space consisting, the optical luminosity of the brightest group galaxy, the optical luminosity difference between the two brightest galaxies in the groups (the luminosity gap), the total luminosity of the group (as a proxy to the group mass) and the physical separation between the luminosity centroid of the galaxy group and its brightest group galaxy. Using this multi-dimensional parameter space we are able to achieve a very high probability in statistical identification of the evolved, e.g. old, and evolving, e.g. young, galaxy groups using purely optical observations. These parameters can be obtained from the optical observations of galaxies alone which are now available from various imaging/spectroscopic surveys.

We note that while the conventional definition of the fossil groups, based on luminosity gap, can result in a contaminated sample of old groups, other probes such as the relaxed X-ray morphology and the co-centring of the X-ray emission and the dominant galaxy in fossil increase the probability of these galaxy groups being old. Observationally, most of the well studied fossil groups [@Khosroshahi2004a; @Sun2004; @Khosroshahi2006; @Khosroshahi2007] meet these criteria.

We show that old systems have more concentrated halos than young ones in various mass bins, in agreement with @Khosroshahi2007 which showed that for a given optical luminosity, fossil groups have a more concentrated halo, compared to non-fossil groups. However, measuring the halo concentration is still subject to large observational uncertainties, which prevents us to use this parameter for a reliable halo age dating in combination with other observables, routinely available from optical observations of galaxies.

We note that the there may some differences in the galaxy properties assigned to sub halos in different semi-analytic models [@Bower2006; @DeLucia2007; @Guo11] but this can only have a minor impact on the the values of the boundaries between the subregions in the parameter space introduced here.

Acknowledgments {#acknowledgments .unnumbered}
===============

The Millennium Simulation database used in this paper and the web application providing online access to them were constructed as part of the activities of the German Astrophysical Virtual Observatory. We thankfully acknowledge Gerard Lemson for facilitating the access to the data.

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[^1]: E-mail: m.raouf@ipm.ir


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“Rainbow Dash is one feisty Pegasus pony, but it is her amazing sense of loyalty that makes her stand out from the rest. Representing her rainbow mane and sky blue hues, Rainbow Dash controls the weather in Ponyville and finds adventures along the way.


Human vaccinia infection after contact with a raccoon rabies vaccine bait - Pennsylvania, 2009.
Since 2003, the U.S. Department of Agriculture's Wildlife Services has coordinated a multistate oral rabies vaccination (ORV) program for wildlife in a 15-state zone extending from Maine to Alabama and in Texas. The program seeks to enhance local control and prevent the spread of epizootic rabies among raccoons and, in Texas, among gray foxes and coyotes. The program uses baits containing liquid vaccinia-rabies glycoprotein (V-RG) recombinant virus vaccine. Because contact with ruptured baits can produce vaccinia virus infection in certain persons, surveillance for human and domestic animal contact with the baits is conducted, relying largely on reports from persons who find baits and call telephone numbers printed on them. In August 2009, during the autumn baiting campaign in western Pennsylvania, a woman aged 35 years who was taking immunosuppressive medication for inflammatory bowel disease contacted the Pennsylvania Department of Health (PADOH) after handling a ruptured bait, which had leaked liquid rabies vaccine onto a patch of abraded skin on her right hand. The patient subsequently developed vaccinia virus infection and was treated with human vaccinia immune globulin intravenous (VIGIV) and an investigational antiviral agent. This report describes this case, which was the second case of human vaccinia infection related to the ORV program. Public health agencies should educate the public, and particularly pet owners, regarding potential hazards associated with handling wildlife rabies vaccine baits and should provide guidance for persons exposed to this vaccine.


RN Wound Care Nurse Certification Course

The Wound Care Nurse Certification Course curriculum is designed by certified, highly experienced wound care specialists, offering access to the most current, accurate information, technologies, and best practices.

Wound Care Nurse Certification Course for Associate RN’s

Course Eligibility Requirements

The Wound Care Nurse Certification Course for RN’s is recommended for registered nurses with an Associates Degree or Diploma.

Anyone is free to enroll in the Wound Care Nurse Certification Course for RN’s. However, only students meeting the certifying body’s criteria are eligible to take the wound certification examination and receive certification credentials.

The wound care certification examination and credentials are provided by a national inter-disciplinary certifying board for healthcare professionals involved in wound care. RNs with three years of clinical experience and at least a high school diploma are eligible to take the national wound certification examination. The test fee for the wound certification examination is $375 (this fee is not included in the price of the course).

Many nurses are driven to obtain wound care nurse certification because they love the independence that wound care nurses often enjoy. They also enjoy the unparalleled sense of accomplishment in seeing a wound that some might view as unhealable through to complete wound healing. Being a wound care nurse can be a very fulfilling job, both personally and professionally. A wound care nurse can often command a higher salary and earns the respect of colleagues and employers alike. Wound care nurse certification can set you apart from the pack and can help you achieve your professional goals.

RN Financial FAQs

Do you offer financial aid?No. At this time we do not offer financial aid for our courses. However, many employers support continuing education and may be willing to assist with course fees. If you would like information to provide to your employer please contact us.

Do you accept partial payment?No. Once you register for our course you will be granted login information for the entire course. You will also receive our Wound Management training kit which includes all course material. For this reason we are unable to accept partial payment.

Do you offer group discounts?Discounts are provided for group registrations. Please contact sales to discuss your needs:sales@woundeducators.com.

RN Course FAQs

What is the requirement to enroll in the RN Wound Certification Course?Anyone may enroll in this course; however, only students meeting wound certification criteria are eligible to take the certification examinations.

How long will I have login access to the online modules?Course access is granted for 6 months.

If I fail the certification examination will there be a fee to retake the course?NO! The WoundEducators.com “Until You Pass!” Risk-Free Guarantee ensures that your training investment lasts. All product and course purchases are covered by our commitment to you and your success. Simply provide us with proof that you took the wound certification examination and did not pass and have re-registered for the exam and we will continue your online course access.

How long does it generally take to complete the course?The RN Wound Certification Course will take approximately 50 hours to complete. However, each student progresses at his/her own pace, so individual completion times may vary.

What is the cost of the course?The fee for the RN Wound Certification Course is $797. This includes the online course, post-course test, continuing education certificate and home study kit. The fee does not include the certification examination.

Do you offer customized competency training for organizations?Yes. Customized online training is available to meet the needs of your organization. Please contact sales to discuss your needs: sales@woundeducators.com

RN Continuing Education FAQs

How much continuing education credit is provided with the RN Wound Certification Course?50 CE credit hours are provided.

How do I know if a continuing education activity is accepted by my state board?

This continuing nursing education activity was approved by New Jersey State Nurses Association, an accredited approver by the American Nurses Credentialing Center’s Commission On Accreditation.

The NJSNA is an accredited approver by the American Nurses Credentialing Center’s Commission on Accreditation. Our course approval is accepted in all States.

The wound certification course is ANCC approved and the CE hours are accepted in all states.

RN Certification FAQs

Who administers the wound certification examination?The CWCA wound care certification examination is administered by the American Board of Wound Management – ABWM (Formerly American Academy of Wound Management -AAWM). The ABWM is a national inter-disciplinary certifying board for healthcare professionals involved in wound care.

What are the eligibility requirements to take the wound certification examination?Any healthcare professional with at least three years of experience is eligible to take the CWCA® examination, with a minimum education level of a high school diploma or equivalent. Please note: If you are not sure if you meet the eligibility requirements to take the wound certification examination, please email the ABWM at: info@abwmcertified.org or call (202) 457-8408.

When are the next wound certification test dates?The Certified Wound Care Associate (CWCA) Exam is offered in a continuous testing cycle. Completed applications must be received in the ABWM office a minimum of 15 business days prior to the desired testing date. Once approved, candidates may schedule their examination for any time in the following six months, based on availability.

Where is the wound certification examination administered?The CWCA wound certification examination will be offered at 170 sites across the United States. For more information on the exam scheduling click here.

What is the cost to sit for the national board certification examination administered by the ABWM?The CWCA exam fee is $375.

Where can I find additional information about the CWCA exam?Information about the certification exams can be accessed at the ABWM website:www.abwmcertified.org.

Can I use the RN Wound Certification Course to obtain the WCC wound care certification?Yes. The RN Wound Certification Course may be used as preparation for the WCC wound care certification provided you meet the WCC eligibility requirements. For more information about the WCC visit the nawccb.org.

If you require additional CE hours to meet the WCC requirement, WoundEducators.com will provide access to these additional hours free of charge.

After months of distractions and disasters, I finally took the certification exam for NAWCO and guess what? I PASSED! The Wound Educators course equipped me with all the tools I needed to prepare. All of the material on the exam was thoroughly addressed in the course. Thank you for your support and encouragement!Sue Hill, RN,WCC. ; )

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RN Wound Care Nurse Certification Course

Sep 27, 2013byMaria Verna Clemente, RN, CWCA

To all the management and staff of WoundEducators.com, thank you so much for helping me passed the ABWM exam that I took last Sept 16. Now I am proud to say I am RN, CWCA. That\'s a lot of text material and online study you provided me but it works. Again, Thank you.

From, Maria Verna Clemente, RN, CWCA

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RN Wound Care Nurse Certification Course

Sep 21, 2010byTerri K., RN, CWCA - Palmdale, CA

Hi all, just a note to say that I passed the CWCA test the AAWM gives! Got my score of 134 of 150.

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RN Wound Care Nurse Certification Course

Sep 20, 2010byMike P., RN, CWS - Maurepas, LA

I just passed the CWCA exam. (Mike took the RN wound care certification course).

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RN Wound Care Nurse Certification Course

Mar 08, 2010byDebbie S., RN, CWCA Assistant Director of Nursing

Hope all is going well with you. I was very happy with the course that you provided therefore, I have recommended your course to one of my co-workers. We sent her information out last week and I was just wondering if you received it yet?

I have been one of your students in wound management course. Your materials, teaching strategy is very helpful and has provided a good training ground to enhance my learning experience. I would like to thank you and Bill for being very prompt with your responses whenever I ask for assistance. My learning experience with Wound Educators is incredible and I would recommend this to my friends.

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Jan 22, 2014bySue Hill, RN,WCC

After months of distractions and disasters, I finally took the certification exam for NAWCO and guess what? I PASSED! The Wound Educators course equipped me with all the tools I needed to prepare. All of the material on the exam was thoroughly addressed in the course. Thank you for your support and encouragement!
Sue Hill, RN,WCC. ; )


Abiogenesis, in biology, the term, equivalent to the older terms "spontaneous generation," Generatio aequivoca, Generatio primaria, and of more recent terms such as archegenesis and archebiosis, for the theory according to which fully formed living organisms sometimes arise from not-living matter. Aristotle explicitly taught abiogenesis, and laid it down as an observed fact that some animals spring from putrid matter, that plant-lice arise from the dew which falls on plants, that fleas are developed from putrid matter, and so forth. T. J. Parker (Elementary Biology) cites a passage from Alexander Ross, who, commenting on Sir Thomas Browne's doubt as to "whether mice may be bred by putrefaction," gives a clear statement of the common opinion on abiogenesis held until about two centuries ago. Ross wrote: "So may he (Sir Thomas Browne) doubt whether in cheese and timber worms are generated; or if beetles and wasps in cows' dung; or if butterflies, locusts, grasshoppers, shell-fish, snails, eels, and such like, be procreated of putrefied matter, which is apt to receive the form of that creature to which it is by formative power disposed. To question this is to question reason, sense and experience. If he doubts of this let him go to Egypt, and there he will find the fields swarming with mice, begot of the mud of Nylus, to the great calamity of the inhabitants."

The first step in the scientific refutation of the theory of abiogenesis was taken by the Italian Redi, who, in 1668, proved that no maggots were "bred" in meat on which flies were prevented by wire screens from laying their eggs. From the 17th century onwards it was gradually shown that, at least in the case of all the higher and readily visible organisms, abiogenesis did not occur, but that omne vivum e vivo, every living thing came from a pre-existing living thing.

The discovery of the microscope carried the refutation further. In 1683 A. van Leeuwenhoek discovered bacteria, and it was soon found that however carefully organic matter might be protected by screens, or by being placed in stoppered receptacles, putrefaction set in, and was invariably accompanied by the appearance of myriads of bacteria and other low organisms. As knowledge of microscopic forms of life increased, so the apparent possibilities of abiogenesis increased, and it became a tempting hypothesis that whilst the higher forms of life arose only by generation from their kind, there was a perpetual abiogenetic fount by which the first steps in the evolution of living organisms continued to arise, under suitable conditions, from inorganic matter. It was due chiefly to L. Pasteur that the occurrence of abiogenesis in the microscopic world was disproved as much as its occurrence in the macroscopic world. If organic matter were first sterilized and then prevented from contamination from without, putrefaction did not occur, and the matter remained free from microbes. The nature of sterilization, and the difficulties in securing it, as well as the extreme delicacy of the manipulations necessary, made it possible for a very long time to be doubtful as to the application of the phrase omne vivum e vivo to the microscopic world, and there still remain a few belated supporters of abiogenesis. Subjection to the temperature of boiling water for, say, half an hour seemed an efficient mode of sterilization, until it was discovered that the spores of bacteria are so involved in heat-resisting membranes, that only prolonged exposure to dry, baking heat can be recognized as an efficient process of sterilization. Moreover, the presence of bacteria, or their spores, is so universal that only extreme precautions guard against a re-infection of the sterilized material. It may now be stated definitely that all known living organisms arise only from pre-existing living organisms.

So far the theory of abiogenesis may be taken as disproved. It must be noted, however, that this disproof relates only to known existing organisms. All these are composed of a definite substance, known as protoplasm (q.v.), and the modern refutation of abiogenesis applies only to the organic forms in which protoplasm now exists. It may be that in the progress of science it may yet become possible to construct living protoplasm from non-living material. The refutation of abiogenesis has no further bearing on this possibility than to make it probable that if protoplasm ultimately be formed in the laboratory, it will be by a series of stages, the earlier steps being the formation of some substance, or substances, now unknown, which are not protoplasm. Such intermediate stages may have existed in the past, and the modern refutation of abiogenesis has no application to the possibility of these having been formed from inorganic matter at some past time. Perhaps the words archebiosis, or archegenesis, should be reserved for the theory that protoplasm in the remote past has been developed from not-living matter by a series of steps, and many of those, notably T. H. Huxley, who took a large share in the process of refuting contemporary abiogenesis, have stated their belief in a primordial archebiosis. (See Biogenesis and Life.)