scholarly journals Continental variation in relative hippocampal volume in birds: the phylogenetic extent of the effect and the potential role of winter temperatures

2005 ◽  
Vol 1 (3) ◽  
pp. 330-333 ◽  
Author(s):  
László Zsolt Garamszegi ◽  
Jeffrey R Lucas
Keyword(s):  
North American ◽  
Potential Role ◽  
Ecological Factors ◽  
Hippocampal Volume ◽  
North American Species ◽  
Food Hoarding ◽  
Evolutionary Spectrum ◽  
Winter Temperatures ◽  
Using Data

Hippocampal (HC) volume has been hypothesized to increase with an increase in food-hoarding specialization in corvids and parids. Recent studies revealed that (i) the HC/hoarding relationship is significant when a difference in HC volume between Eurasian and North American species is controlled for and (ii) the evolutionary association has been acting on a broader phylogenetic context involving avian families outside the Corvidae and Paridae. However, the phylogenetic extent of the continent effect has not been previously addressed. Using data representing 48 avian species, we performed a phylogenetic analysis to test if continental effects are important in a wider evolutionary spectrum. Our results support the observation that Eurasian species have generally larger HC than North American species if variation in food hoarding, which also varied between continents, was held constant. Surprisingly, the relationship between continental distribution and relative HC volume was significant when we included only non-hoarding families in our analysis, indicating that the extent of the continent effect is much broader than originally described. We investigated the potential role of minimal winter temperatures at the northernmost distribution borders in mediating continent effects. The effect of winter temperatures on HC volume was weak and it did not vary consistently along continents. We suggest that the general continental differences in relative HC size are independent of food hoarding and that its determinants should be sought among other ecological factors and life-history traits.

Investigating the Potential Role of North American Animals as Hosts for Zika Virus

2017 ◽  
Vol 17 (3) ◽  
pp. 161-164 ◽  
Author(s):  
Izabela K. Ragan ◽  
Emily L. Blizzard ◽  
Paul Gordy ◽  
Richard A. Bowen
Keyword(s):  
North American ◽  
Zika Virus ◽  
Potential Role

Cercarial swimming performance and its potential role as a key variable of trematode transmission

Parasitology ◽  
2020 ◽  
Vol 147 (12) ◽  
pp. 1369-1374 ◽  
Author(s):  
Neil J. Morley
Keyword(s):  
Swimming Speed ◽  
Potential Role ◽  
Swimming Performance ◽  
Tail Length ◽  
Host Searching ◽  
Aquatic Habitats ◽  
Searching Behaviour ◽  
Biological Variables ◽  
Using Data

AbstractTrematode transmission in aquatic habitats from molluscan intermediate host to vertebrate or invertebrate target host is typically undertaken by a free-living stage known as cercariae. Active locomotion by cercariae is a key aspect of the transmission process with the swimming speed potentially contributing to infection success. Individual cercarial species swim at different speeds but the significance of this to infection potential has not been determined. This study, using data from the scientific literature, investigates the role of swimming speed in relation to cercarial morphology, host-searching strategies and target host species. Larger cercariae swim faster than smaller ones with tail length being the principal factor controlling locomotion rates. Different cercarial morphotypes swim at different speeds, in particular, furcocercariae, with the exception of the schistosomes, being faster swimmers than mono-tailed cercariae. Host-searching behaviour has a significant influence on swimming speeds with ‘active-searching’ strategies swimming slower than those adopting ‘active-waiting’ or ‘prey mimcry’ strategies. Vertebrate-infecting cercariae swim faster than those infecting invertebrates with species targeting fish demonstrating the highest locomotion rates and those targeting arthropods the slowest speeds. The adaptions of individual cercarial swimming speeds to biological variables and their interactions with the physical processes of aquatic habitats are discussed.

scholarly journals Impact of Economic Shocks on Cumulative Advantage Processes: Recession, Recovery, and Trajectories of Inequality

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 508-508
Author(s):  
Stephen Crystal
Keyword(s):  
Potential Role ◽  
Population Level ◽  
Survey Of Consumer Finances ◽  
Subsequent Recovery ◽  
The Great Recession ◽  
Consumer Finances ◽  
Age Cohort ◽  
Using Data ◽  
The Life Course

Abstract This study compares the effect of the 2008 recession and subsequent recovery across generational cohorts by evaluating age-cohort trajectories of income inequality. Using data from the 2007 to 2016 waves of the Survey of Consumer Finances, we examine the trajectory of inequality for the overall population and by cohort in years spanning the Great Recession and subsequent recovery. We find that increases in per-capita income and wealth observed at the population-level during the recovery were not reflected among households below the median, leading to increasing inequality. Within cohorts, we observe growing inequality within cohorts in their primary working years. Findings are consistent with a model of integrative cumulative dis/ advantage, which predicts increasing within-cohort inequality over the life course influenced both by persistent micro- and macro-level processes of increasing heterogeneity. Our analyses highlight the potential role of extreme business cycle fluctuations, booms and busts, to exacerbate this underlying process.

Implications of The National Employment Savings Trust for Vulnerable Sectors of the UK Labour Market: A Reduced-Form Statistical Evaluation

2012 ◽  
Vol 219 ◽  
pp. R77-R89 ◽  
Author(s):  
Justin van de Ven
Keyword(s):  
Potential Role ◽  
Statistical Evaluation ◽  
Reduced Form ◽  
Pension Scheme ◽  
Annual Survey ◽  
Labour Costs ◽  
Using Data ◽  
The Uk ◽  
Low Pay

The National Employment Savings Trust (NEST) is a new pension scheme that will be introduced for employees on modest incomes in the UK from 2012. This paper draws out the implications of the NEST, focusing upon low-paid employees and their employers using data from the Annual Survey of Hours and Earnings. The results suggest that the NEST will increase labour costs by between 0.6 and 0.8 per cent on average, and have a disproportionate effect on low pay industries and private sector firms employing fewer than 25 employees. The analysis highlights the potential role of the minimum wage to shield low pay workers from paying a share of the subsidies that the NEST will afford to its members.

scholarly journals Assesssing the role of humans in Greater Antillean land vertebrate extinctions: new insights from Cuba

2020 ◽  
Author(s):  
Johanset Orihuela ◽  
Lázaro W. Viñola ◽  
Osvaldo Jiménez Vázquez ◽  
Alexis M. Mychajliw ◽  
Odlanyer Hernández de Lara ◽  
...  
Keyword(s):  
Potential Role ◽  
Late Quaternary ◽  
Ecological Factors ◽  
High Rate ◽  
Archaeological Record ◽  
Cultural Groups ◽  
Archaeological Data ◽  
The Caribbean ◽  
Land Vertebrate

ABSTRACTThe Caribbean archipelago is a hotspot of biodiversity characterized by a high rate of extinction. Recent studies have examined these losses, but the causes of the Antillean Late Quaternary vertebrate extinctions, and especially the role of humans, are still unclear. Current results provide support for climate-related and human-induced extinctions, but often downplaying other complex bio-ecological factors that are difficult to model or to detect from the fossil and archaeological record. Here, we discuss Caribbean vertebrate extinctions and the potential role of humans derived from new and existing fossil and archaeological data from Cuba. Our results indicate that losses of Cuba’s native fauna occurred in three waves: one during the late Pleistocene and early Holocene, a second during the middle Holocene, and a third one during the last 2 ka, coinciding with the arrival of agroceramists and the early Europeans. The coexistence of now-extinct species with multiple cultural groups in Cuba for over 4 ka implies that Cuban indigenous non-ceramic cultures exerted far fewer extinction pressures to native fauna than the later agroceramists and Europeans that followed. This suggests a determinant value to increased technological sophistication and demographics as the most plausible effective extinction drivers.

scholarly journals Hepcidin as a Predictor of Response to Epoetin Therapy in Anemic Cancer Patients

2009 ◽  
Vol 55 (7) ◽  
pp. 1354-1360 ◽  
Author(s):  
Lidia Ukarma ◽  
Hélène Johannes ◽  
Ulrich Beyer ◽  
Michel Zaug ◽  
Bruno Osterwalder ◽  
...  
Keyword(s):  
Cancer Patients ◽  
Potential Role ◽  
Predictive Marker ◽  
Patients With Cancer ◽  
Pooled Data ◽  
Significant Difference ◽  
Serum Hepcidin ◽  
High Concentrations ◽  
Using Data

Abstract Background: Hepcidin is thought to be the central regulator of iron metabolism. Iron deficiency is associated with low hepcidin concentrations, and anemia in patients with cancer is associated with high concentrations of hepcidin. Study objectives: Our main objective was to assess the potential role of hepcidin for predicting response to epoetin therapy in anemic cancer patients. We also aimed to identify a cutoff value for hepcidin as a potential predictive marker for response to epoetin therapy. Methods: Using data from 525 anemic cancer patients enrolled in 5 studies, we assessed serum hepcidin concentrations in 408 of these patients at baseline and analyzed pooled data from the 408 patients. The analysis population was separated into 2 categories using a threshold hepcidin concentration of 13 nmol/L: low hepcidin (<13 nmol/L) and high hepcidin (≥13 nmol/L). Results: A significantly higher percentage of responders (defined as hemoglobin increase ≥10 g/L or ≥20 g/L from baseline) was observed in the low hepcidin group compared with the high hepcidin group (P = 0.04 for ≥10 g/L increase and P = 0.009 for ≥20 g/L from baseline). There was also a statistically significant difference between the 2 groups for hematopoietic response (hemoglobin rise at least once ≥20 g/L from baseline or at least once ≥120 g/L) to epoetin therapy (P = 0.0004). Conclusions: The results of this analysis suggest a potential role of hepcidin serum concentrations in predicting the response to epoetin therapy.

Polyploidy and possible implications for the evolutionary history of some Australian Danthonieae

2010 ◽  
Vol 58 (1) ◽  
pp. 23 ◽  
Author(s):  
C. Waters ◽  
B. G. Murray ◽  
G. Melville ◽  
D. Coates ◽  
A. Young ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Potential Role ◽  
New South ◽  
Ecological Factors ◽  
Distribution Patterns ◽  
Low Frequencies ◽  
Rapid Speciation ◽  
South Wales ◽  
History Of

Polyploidy is a widespread feature of some plants that allows for rapid speciation and occurs widely in Poaceae. However, there have been few studies of Australian native grasses reporting the distribution patterns of cytotypes and examining the potential role of different cytotypes in adaptation. We determined chromosome number for 48, 113, 8, 43 and 33 plants of Austrodanthonia bipartita (Link) H.P.Linder, A. caespitosa (Gaudich.) H.P.Linder, A. eriantha (Lindl.) H.P.Linder, A. fulva (Vickery) H.P.Linder and A. setacea (R.Br.) H.P.Linder, respectively, representing 28 wild populations collected in central western New South Wales. A widespread distribution is reported for tetraploids (2n = 48), whereas diploids (2n = 24) and a limited number of hexaploids (2n = 72) appear to be associated with northern and western populations. In all populations, coexistent cytotypes were found, although tetraploids were the most widespread cytotype for the most commonly occurring species, A. caespitosa. The occurrence of low frequencies of putative intermediate cytotypes, particularly triploids, in all five species provides evidence for inter-specific hybridisation and/or intra-specific crossing between cytotypes. The lack of common ecological factors (climate, edaphic or micro-site) that clearly distinguish diploid from tetraploid A. caespitosa plants provides further evidence for hybridisation between cytological races of this species.

Potential Role of Passenger Pigeons and Other Vertebrates in the Rapid Holocene Migrations of Nut Trees

1986 ◽  
Vol 26 (3) ◽  
pp. 367-375 ◽  
Author(s):  
Sara L. Webb
Keyword(s):  
Seed Dispersal ◽  
Potential Role ◽  
North American Species ◽  
Species Range ◽  
Range Extension ◽  
The Holocene ◽  
Seed Predators ◽  
Light Wind ◽  
Dispersal Distances

Rapid rates of species range extension during the Holocene represent seed dispersal distances of at least 6 to 8 km per generation for North American species of Fagus, Quercus, and Carya, taxa whose fruits are heavy nuts. Occasional seed dispersal by biotic seed predators is necessary for these dispersal distances. One likely agent for dispersal across long distances and habitat discontinuities was the extinct (since 1914 A.D.) passenger pigeon (Ectopistes migratorius). This bird's abundance, capacity for delayed digestion, and nomadic habits strongly suggest an occasional seed dispersal role, although a coevolutionary seed dispersal relationship cannot be inferred from available evidence. The capacity of some heavy seeds for dispersal distances greater than those of most light, wind-dispersed seeds has biogeographic and genetic implications.

POPDC proteins and cardiac function

2019 ◽  
Vol 47 (5) ◽  
pp. 1393-1404 ◽  
Author(s):  
Thomas Brand
Keyword(s):  
Potential Role ◽  
Striated Muscle ◽  
Short Review ◽  
Effector Proteins ◽  
Muscle Disease ◽  
Disease Genes ◽  
Protein Protein Interaction ◽  
Interaction Partners ◽  
And Function

Abstract The Popeye domain-containing gene family encodes a novel class of cAMP effector proteins in striated muscle tissue. In this short review, we first introduce the protein family and discuss their structure and function with an emphasis on their role in cyclic AMP signalling. Another focus of this review is the recently discovered role of POPDC genes as striated muscle disease genes, which have been associated with cardiac arrhythmia and muscular dystrophy. The pathological phenotypes observed in patients will be compared with phenotypes present in null and knockin mutations in zebrafish and mouse. A number of protein–protein interaction partners have been discovered and the potential role of POPDC proteins to control the subcellular localization and function of these interacting proteins will be discussed. Finally, we outline several areas, where research is urgently needed.

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