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List of Imperiled Birds, Ranked By ED and Scored for Ex Situ Suitability

Peer reviewed: 
No, item is not peer reviewed.
Date created: 
2019-01-24
Abstract: 

Dataset (as excel file) with all imperiled bird species along with data that may help to guide prioritization for ex situ conservation programs. SS3a lists 506 imperiled species not currently held in ZIMS (Zoological Information Management System) global zoo networks, ranked by Evolutionary Distinctness (ED) score.  Each species is also scored for family membership, how many confamilials are in a ZIMS facility (as a measure of husbandry expertise), their biogeographical realm, and notes on whether there is evidence of non-ZIMS or non-zoo ex situ programs or holdings. Data on non-ZIMS holdings was gathered from the International Union for Conservation of Nature (2016) and personal communication from M. Lamont, S. Bruslund-Jensen and J. Lindholm III. Data from personal correspondence is accurate to the best of our current knowledge but is not exhaustive of all private or non-zoo holdings. SS3b lists 111 imperiled species found in ZIMS institutions, ranked by ED score. In addition to the criteria in SS3a, we list also list the number of female breeding individuals and total breeding individuals for captive populations (data collected from ZIMS (2017)).

Document type: 
Dataset
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Placental Villous Hypermaturation is Associated with Improved Neonatal Outcomes

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2019-01-14
Abstract: 

Introduction: Accelerated placental maturation is considered a sign of maternal vascular malperfusion, and is often interpreted as an adaptive, compensatory response by the placenta. We tested this interpretation by comparing outcomes in pregnancies with and without accelerated maturation.

Methods: Using data from the National Collaborative Perinatal Project, we categorized preterm placentas (24 - 34 weeks, inclusive; 2525 births) by whether they showed placental villous hypermaturation (PVH), i.e., had the appearance of a placenta of 37 weeks or over upon microscopic examination. We assessed whether PVH was associated with maternal race, maternal BMI, fetal sex, type of preterm birth, preeclampsia, signs of infection or inflammation or placental abruption. We also assessed whether placentas showing PVH were associated with improved outcomes in terms of survival, Apgar score, or oxygen use.

Results: PVH was more common in preeclamptic pregnancies and less common in pregnancies complicated by placental abruption or showing signs of placental infection or inflammation. Adjusting for potentially confounding factors, PVH was associated with reduced odds of fetal death, death between birth and 120 days of age, low Apgar scores and oxygen use. PVH was also associated with higher birthweights for gestational age. When correcting for the effect of birthweight, the association between PVH and reduced fetal and neonatal death remained significant.

Discussion: Accelerated placental maturation, as manifested by PVH, is associated with improved outcomes. Our work therefore supports the hypothesis that accelerated maturation is a compensatory response by the placenta to improve its transport capacity in specific pregnancy complications.

Document type: 
Article

Body size variation in the sexually dimorphic scaphopod Rhabdus rectius (Carpenter, 1864) (Dentaliida: Rhabdidae)

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2018-11-25
Abstract: 

Male-biased sexual size dimorphism typically evolves via sexual selection for larger males that are favoured by choosy females or are more successful in mate competition with other males. Among marine invertebrates that broadcast their gametes into the ocean for fertilisation, this form of sexual size dimorphism is rare because such species lack direct interactions among males or between the sexes. However, the broadcast-spawning tusk shell Rhabdus rectius was recently reported to show strong male-biased sexual size dimorphism. That pattern might imply interesting and undiscovered sexual selection in this species. We found instead that the distribution of body size variation (weight, shell length) was similar between males and females of R. rectius, and mean sizes were not different between the sexes. However, we noted a male-biased sex ratio (~1:1.3) in our large sample of individuals. Many live scaphopods (and several dead shells) showed partial or complete boreholes drilled by predatory gastropods. Boreholes were observed on males and females in similar proportions. We collected scaphopods along with multiple individuals of one likely scaphopod predator, the small moon snail Euspira pallida, and in the lab we observed successful attacks by moon snails on tusk shells.

Document type: 
Article

Pappa2 Deletion Has Sex- and Age-Specific Effects on Bone in Mice

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2018-10-31
Abstract: 

Objective

In humans, loss-of-function mutations in the gene encoding pregnancy-associated pregnancy protein-A2 cause short stature and slightly reduced bone density. The goal of this study was to determine the effects of Pappa2 deletion on bone in mice.

Design

Pappa2 deletion mice and littermate controls were culled at 10, 19 or 30 weeks of age and femurs were analysed by micro-computed tomography. Serum markers of bone turnover and insulin-like growth factor binding protein 5 (IGFBP-5), a proteolytic target of PAPP-A2, were measured by ELISA.

Results

At 10 and 19 weeks of age, Pappa2 deletion mice had slightly reduced trabecular parameters, but by 19 weeks of age, female deletion mice had increased cortical tissue mineral density, and this trait was increased by a small amount in deletion mice of both sexes at 30 weeks. Cortical area fraction was increased in Pappa2 deletion mice at all ages. Deletion of Pappa2 increased circulating IGFBP-5 levels and reduced markers of bone turnover (PINP and TRACP 5b).

Conclusions

PAPP-A2 contributes to the regulation of bone structure and mass in mice, likely through control of IGFBP-5 levels. The net effect of changes in bone formation and resorption depend on sex and age, and differ between trabecular and cortical bone

Document type: 
Article

Palladin Compensates for the Arp2/3 Complex and Supports Actin Structures during Listeria Infections

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2018-04-10
Abstract: 

Palladin is an important component of motile actin-rich structures and nucleates branched actin filament arrays in vitro. Here we examine the role of palladin during Listeria monocytogenes infections in order to tease out novel functions of palladin. We show that palladin is co-opted by L. monocytogenes during its cellular entry and intracellular motility. Depletion of palladin resulted in shorter and misshapen comet tails, and when actin- or VASP-binding mutants of palladin were overexpressed in cells, comet tails disintegrated or became thinner. Comet tail thinning resulted in parallel actin bundles within the structures. To determine whether palladin could compensate for the Arp2/3 complex, we overexpressed palladin in cells treated with the Arp2/3 inhibitor CK-666. In treated cells, bacterial motility could be initiated and maintained when levels of palladin were increased. To confirm these findings, we utilized a cell line depleted of multiple Arp2/3 complex subunits. Within these cells, L. monocytogenes failed to generate comet tails. When palladin was overexpressed in this Arp2/3 functionally null cell line, the ability of L. monocytogenes to generate comet tails was restored. Using purified protein components, we demonstrate that L. monocytogenes actin clouds and comet tails can be generated (in a cell-free system) by palladin in the absence of the Arp2/3 complex. Collectively, our results demonstrate that palladin can functionally replace the Arp2/3 complex during bacterial actin-based motility.

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The Roles of Extrinsic and Intrinsic Factors in the Freshwater Life-History Dynamics of a Migratory Salmonid

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2018-09-26
Abstract: 

Key life-cycle transitions, such as metamorphosis or migration, can be altered by a variety of external factors, such as climate variation, strong species interactions, and management intervention, or modulated by density dependence. Given that these life-history transitions can influence population dynamics, understanding the simultaneous effects of intrinsic and extrinsic controls on life-history expression is particularly relevant for species of management or conservation importance. Here, we examined how life histories of steelhead (Oncorhynchus mykiss) are affected by weather, pink salmon abundance (Oncorhynchus gorbuscha), experimental nutrient addition, and density-dependent processes. We tested for impacts on the size of steelhead smolts (juveniles migrating to the sea), as well as their age and abundance across four decades in the Keogh River, British Columbia, Canada. Larger steelhead smolts were associated with warmer years and artificial nutrient addition. In addition, higher pink salmon abundance and artificial nutrient addition correlated with juvenile steelhead migrating at younger ages. While density dependence appeared to be the primary factor regulating the abundance of steelhead smolts, nutrient addition and temperature were positively and negatively associated with smolt production, respectively, prior to 1991, and pink salmon spawning abundance was positively associated with smolt production after 1990. Thus, this study provides evidence that the temporal dynamics of one species of salmon is linked to the juvenile life history of co-occurring steelhead. A complex interplay of species interactions, nutrient subsidies, density dependence, and climatic variation can control the life-history expression of species with complex life cycles.

Document type: 
Article
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Why Have Global Shark and Ray Landings Declined: Improved Management or Overfishing?

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2015-05-11
Abstract: 

Global chondrichthyan (shark, ray, skate, and chimaera) landings, reported to the United Nations Food and Agriculture Organization (FAO), peaked in 2003 and in the decade since have declined by almost 20%. In the FAO’s 2012 “State of the World’s Fisheries and Aquaculture” report, the authors “hoped” the reductions in landings were partially due to management implementation rather than population decline. Here, we tested their hypothesis. Post-peak chondrichthyan landings trajectories from 126 countries were modelled against seven indirect and direct fishing pressure measures and eleven measures of fisheries management performance, while accounting for ecosystem attributes. We found the recent improvement in international or national fisheries management was not yet strong enough to account for the recent decline in chondrichthyan landings. Instead, the landings declines were more closely related to fishing pressure and ecosystem attribute measures. Countries with the greatest declines had high human coastal population sizes or high shark and ray meat exports such as Pakistan, Sri Lanka, and Thailand. While important progress has been made, country-level fisheries management measures do not yet have the strength or coverage to halt overfishing and avert population declines of chondrichthyans. Increased implementation of legally binding operational fisheries management and species-specific reporting is urgently required to avoid declines and ensure fisheries sustainability and food security.

Document type: 
Article
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The Problem with Using the Birthweight:Placental Weight Ratio as a Measure of Placental Efficiency

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2018-07-03
Abstract: 

Introduction

The ratio of birthweight to placental weight (BW:PW) is often used as a measure of placental efficiency in humans and animals. However, ratios have properties that are known to lead to spurious results. An alternative approach is the use of residuals from regression, which reflect whether birthweight is higher or lower than expected for a given placental weight, given the population pattern. We hypothesized that biologically meaningful measures of placental efficiency would differ between placentas with and without pathology, and between adverse and normal perinatal and postnatal outcomes.

Methods

We examined associations between measures of placental efficiency (BW:PW ratio or residuals) and placental pathologyApgar scores and infant death using National Collaborative Perinatal Project data (4645 preterm births and 28497 term births).

Results

BW:PW ratios and residuals were significantly lower in placentas showing pathologies including signs of large infarcts or hemorrhage, although many of these differences were small. Low BW:PW ratios and residuals were also associated with low Apgar scores and increased risk of postnatal death. Whereas residuals were lower in term placentas that appeared immature by microscopic examination, the opposite was true for BW:PW ratios.

Conclusion

The BW:PW ratio produced an artefact whereby histologically less mature placentas at term appeared to be more “efficient” than mature placentas, illustrating a known problem with the use of ratios. For other traits, residuals generally showed differences between placentas with and without pathology that were as great as those seen with BW:PW ratios, and often showed stronger associations with adverse outcomes.

 

Document type: 
Article

PAPP-A2 Deficiency Does Not Exacerbate the Phenotype of a Mouse Model of Intrauterine Growth Restriction

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2018-06-12
Abstract: 

BACKGROUND:

Pregnancy-associated plasma protein-A2 (PAPP-A2) is consistently upregulated in the placentae of pregnancies complicated by preeclampsia and fetal growth restriction. The causes and significance of this upregulation remain unknown, but it has been hypothesized that it is a compensatory response to improve placental growth and development. We predicted that, if the upregulation of PAPP-A2 in pregnancy complications reflects a compensatory response, then deletion of Pappa2 in mice would exacerbate the effects of a gene deletion previously reported to impair placental development: deficiency of matrix metalloproteinase-9 (MMP9).

METHODS:

We crossed mice carrying deletions in Pappa2 and Mmp9 to produce pregnancies deficient in one, both, or neither of these genes. We measured pregnancy rates, number of conceptuses, fetal and placental growth, and the histological structure of the placenta.

RESULTS:

We found no evidence of reduced fertility, increased pregnancy loss, or increased fetal demise in Mmp9 -/- females. In pregnancies segregating for Mmp9, Mmp9 -/- fetuses were lighter than their siblings with a functional Mmp9 allele. However, deletion of Pappa2 did not exacerbate or reveal any effects of Mmp9 deficiency. We observed some effects of Pappa2 deletion on placental structure that were independent of Mmp9 deficiency, but no effects on fetal growth. At G16, male fetuses were heavier than female fetuses and had heavier placentae with larger junctional zones and smaller labyrinths.

CONCLUSIONS:

Effects of Mmp9 deficiency were not exacerbated by the deletion of Pappa2. Our results do not provide evidence that upregulation of placental PAPP-A2 represents a mechanism to compensate for impaired fetal growth.

 

Document type: 
Article
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Glucocorticoid Manipulations in Free-Living Animals: Considerations of Dose Delivery, Life-History Context, and Reproductive State

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2015-06-23
Abstract: 

1. Experimental glucocorticoid (GC) manipulations can be useful for identifying the mechanisms that drive life history and fitness variation in free-living animals, but predicting the effects of GC treatment can be complicated. Much of the uncertainty about the effects of GC manipulations stems from their multi-faceted role in organismal metabolism, and their variable influence with respect to life-history stage, ecological context, age, sex, and individual variation.

2. Glucocorticoid hormones have been implicated in the regulation of parental care in many vertebrate taxa but in two seemingly contradictory ways, which sets up a potential corticosterone-induced “reproductive conflict”. GCs mediate adaptive physiological and behavioural responses to stressful events, and elevated levels can lead to trade-offs between reproductive effort and survival (e.g. the current reproduction versus survival hypothesis). The majority of studies examining the fitness effects of GC manipulations extend from this hypothesis. However, when animals are not stressed (likely most of the time) baseline GCs act as key metabolic regulators of daily energy balance, homeostasis, osmoregulation, and food acquisition, with pleiotropic effects on locomotor activity or foraging behaviour. Slight increases in circulating baseline levels can then have positive effects on reproductive effort (e.g. the corticosterone fitness/adaptation hypotheses), but comparatively few GC manipulation studies have targeted these small, non-stress induced increases.

3. We review studies of GC manipulations and examine the specific hypotheses used to predict the effects of manipulations in breeding wildlife. We argue that given the dichotomous function of GCs the current ‘reproduction versus survival’ paradigm is unnecessarily restrictive and predicts only deleterious GC effects on fitness. Therefore, a broader set of hypotheses should be considered when testing the fitness effects of GC manipulations.

4. When framing experimental manipulation studies, we urge researchers to consider three key points: life-history context (e.g. long- vs. short-lived, semelparous vs. iteroparous, etc), ecological context, and dose delivery.

 

Document type: 
Article
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