scholarly journals Geographic Variation in Liver Metal Concentrations of Greater Sage-Grouse

2013 ◽  
Vol 4 (2) ◽  
pp. 298-302 ◽  
Author(s):  
Erik J. Blomberg ◽  
Peregrine L. Wolff ◽  
James S. Sedinger
Keyword(s):  
Geographic Variation ◽  
Small Body ◽  
Selenium Deficiency ◽  
Local Variation ◽  
Sage Grouse ◽  
Tissue Concentrations ◽  
Metal Concentrations ◽  
Low Selenium ◽  
Two Populations ◽  
Regional Comparisons

Abstract Populations of greater sage-grouse (Centrocercus urophasianus) have declined throughout the species' range. We evaluated metal concentrations in livers sampled from greater sage-grouse collected from hunters in Eureka County, Nevada, during autumn of 2008 and 2010. We make local comparisons of metal concentrations between two populations of greater sage-grouse in Eureka County, as well as regional comparisons with previously reported values for greater sage-grouse collected in Wyoming and Montana. With one exception, tissue concentrations of lead, arsenic, and mercury were below method detection limits. Mean concentrations of iron, molybdenum, and zinc differed between the two Nevada populations, and magnesium, cadmium, molybdenum, and selenium differed between greater sage-grouse in eastern Nevada, and values reported for Wyoming and Montana. In contrast, we found no evidence for local variation in magnesium, copper, cadmium, or selenium, or for regional variation in iron, zinc, or copper. Of particular interest were low selenium concentrations in our study system relative to Wyoming and Montana. Some individuals in our study returned liver selenium values considered consistent with selenium deficiency in domestic poultry. This research adds to the small body of literature on background contaminant levels in greater sage-grouse, and provides evidence for geographic variation in metal concentrations at local and regional scales.

Density-dependent polyphenism and geographic variation in size among two populations of lubber grasshoppers (Romalea microptera)

2009 ◽  
Vol 34 (5) ◽  
pp. 644-651 ◽  
Author(s):  
JASON E. JANNOT ◽  
ALEXANDER E. KO ◽  
DUSTIN L. HERRMANN ◽  
LAURA SKINNER ◽  
EMILY BUTZEN ◽  
...  
Keyword(s):  
Geographic Variation ◽  
Density Dependent ◽  
Two Populations

scholarly journals Selenium deficiency and HIV infection

2010 ◽  
Vol 2 (2) ◽  
pp. 18 ◽  
Author(s):  
Stefano Di Bella ◽  
Elisabetta Grilli ◽  
Maria Adriana Cataldo ◽  
Nicola Petrosillo
Keyword(s):  
Hiv Infection ◽  
Disease Progression ◽  
Selenium Deficiency ◽  
Selenium Supplementation ◽  
Economic Resources ◽  
Common Finding ◽  
Hiv Viral Load ◽  
Conflicting Evidence ◽  
Low Selenium

Selenium is a non-metallic chemical element of great important to human health. Low selenium levels in humans are associated with several pathological conditions and are a common finding in HIV infected individuals. We conducted a review of the literature to assess if selenium deficiency or selenium supplementation could play a role in modifying the clinical course of HIV disease. Several studies investigated the role of selenium in disease progression, morbidity and mortality in HIV infected individuals. Larger studies were conducted in countries with poor economic resources and limited access to HAART. According to the majority of published studies low selenium levels appear to have an association with mortality, and selenium supplementation appears to play a beneficial role on survival or on slowing disease progression among HIV infected individuals. The role of selenium supplementation on preventing hospital admission among HIV outpatients was also noticed. The literature suggests an association between selenium deficiency and development of HIV associated cardiomyopathy and furthermore, selenium supplementation appears to improve the cardiac function in HIV infected individuals with cardiomyopathy. However, there is conflicting evidence regarding the role selenium in modifying HIV viral load and immune status in HIV infection.

scholarly journals Geographic variation in the morphology of the sand-dwelling lizard Nothobachia ablephara (Squamata: Gymnophthalmidae)

2019 ◽  
Vol 18 (2) ◽  
pp. 195-207
Author(s):  
Carolina Nisa Ramiro ◽  
Renato Sousa Recoder ◽  
Miguel Trefaut Rodrigues
Keyword(s):  
Geographic Variation ◽  
Morphological Traits ◽  
Geographical Variation ◽  
Multivariate Analyses ◽  
Molecular Study ◽  
Northeastern Brazil ◽  
Sexually Dimorphic ◽  
Morphometric Variation ◽  
The One ◽  
Two Populations

Geographic variation in the morphology of the sand-dwelling lizard Nothobachia ablephara (Squamata: Gymnophthalmidae). Nothobachia ablephara is a small microteiid lizard with an elongated body and reduced limbs; it occurs in isolated dune felds in the state of Bahia (Xique-Xique and Alagoado) and small sandy patches in northeastern Brazil. A previous molecular study found a marked mtDNA divergence between populations of N. ablephara from Alagoado and Xique-Xique dunes, suggesting that the two populations diverged from one another between 3 and 4 million years ago. Given this isolation, it is interesting to explore whether morphological traits of the lizards refect the reported genetic divergence of the populations. Scale counts of the sexes and the populations differ signifcantly, but there is considerable overlap of values. Univariate and multivariate analyses revealed signifcant morphometric variation between sexes and populations; however, this is mostly explained by size differences. Females are larger than males in all characters that are sexually dimorphic, and individuals from Xique-Xique are larger than those from Alagoado in all characters that vary geographically. The sample from Alagoado has more sexually dimorphic characters than the one from Xique-Xique. Although N. ablephara displays some geographical variation, the two populations could not be unequivocally distinguished by scale counts and morphometric data.

Geographic variation in the advertisement call of Crinia signifera (Anura:Myobatrachidae) on Kangaroo Island and across southern south-eastern Australia

2008 ◽  
Vol 56 (4) ◽  
pp. 223 ◽  
Author(s):  
Murray J. Littlejohn
Keyword(s):  
Geographic Variation ◽  
Pulse Number ◽  
Advertisement Call ◽  
Regional Study ◽  
South Eastern ◽  
Island Sample ◽  
Eastern Australia ◽  
Continental Islands ◽  
Two Populations ◽  
South Eastern Australia

The male advertisement call of anuran amphibians has a major role in mate choice, and regional variation in this attribute can act as an indicator of speciation and a marker for genetic differentiation. As part of a regional study of geographic variation in the male advertisement call of Crinia signifera across south-eastern Australia and adjacent larger continental islands, samples of advertisement calls from two populations on Kangaroo Island and two populations on the adjacent Fleurieu Peninsula were compared. Four call attributes were considered: pulse number, call duration, pulse rate and dominant frequency. Pulse number is considered the most reliable for comparative purposes because it is not influenced by effective temperature or audio recording and analysis. The two island populations (central and eastern, ~24 km apart) differ significantly in pulse number, with contact but no overlap of interquartile ranges. The eastern sample differs markedly from those on the nearby Fleurieu Peninsula – which are both similar to the more distant central island sample. Geographic variation in pulse number in these four samples and 11 others from two recent publications is then interpreted in the light of land bridges and lower temperatures of the late Pleistocene and early Holocene.

scholarly journals Gammarus Fossarum Koch, 1835: Redescription Based on Neotype Material and Notes on its Local Variation (Crustacea, Amphipoda)

1972 ◽  
Vol 42 (2) ◽  
pp. 124-138 ◽  
Author(s):  
Annemarie Goedmakers
Keyword(s):  
Geographic Variation ◽  
Local Variation ◽  
Morphological Characters ◽  
Gammarus Fossarum ◽  
Different Populations

A redescription of Gammarus fossarum Koch, 1835, is given, together with some notes on the variability in morphological characters of this species, both within one population and in different populations. It is proved through crosses that five morphologically different populations all belong to the same species, G. fossarum. The geographic variation of the various characters is discussed.

scholarly journals Nutritional myodegeneration as a cause of dysphagia in adult horses: three case reports

2008 ◽  
Vol 52 (No. 6) ◽  
pp. 267-272 ◽  
Author(s):  
E. Ludvikova ◽  
P. Jahn ◽  
Z. Lukas
Keyword(s):  
Sodium Selenite ◽  
Case Reports ◽  
Selenium Deficiency ◽  
Selenium Concentration ◽  
Bilateral Symmetry ◽  
Muscle Injuries ◽  
Glutathione Peroxidase Activity ◽  
Muscle Enzymes ◽  
Low Selenium ◽  
Large Groups

Three cases of nutritional myodegeneration caused by selenium deficiency in adult horses are described. Difficulty in eating and drinking was a common clinical sign in all horses. Blood biochemistry revealed a marked elevation of muscle enzymes and low glutathione peroxidase activity or low selenium concentration in whole blood in all cases. The treatment with sodium selenite and vitamin E was instituted in all horses. Two of them were euthanized because of continuing muscle injuries, one patient was cured. The post-mortem examination of euthanized horses revealed pale muscles that were distributed with bilateral symmetry on hind and thoracic limbs, diaphragm, tongue, masticatory and intercostal muscles and the myocardium. Histopathology revealed the areas of degeneration and necrosis. Large groups of regenerating fibres and pronounced lymphoplasmocytic reaction among the groups of intact fibres were also present. The clinical outcome of the disease is probably influenced by timely diagnosis and treatment.

The Incidence of Nematodes in the Fillets of Small God from Lockeport, Nova Scotia, and the Southwestern Gulf of St. Lawrence

1959 ◽  
Vol 16 (2) ◽  
pp. 213-221 ◽  
Author(s):  
D. M. Scott ◽  
W. R. Martin
Keyword(s):  
Nova Scotia ◽  
New Brunswick ◽  
Geographic Variation ◽  
Atlantic Cod ◽  
Age Groups ◽  
Local Variation ◽  
Progressive Increase ◽  
Magdalen Islands

The incidence of nematodes in fillets of Atlantic cod (Gadus callarias) was determined in 1957 in four areas within 10 miles of Lockeport, N.S., and in six areas in the southwestern Gulf of St. Lawrence. About 1,500 cod, mostly between 1 and 6 years of age, were examined. All nematodes examined (517) were larvae. About 97% belonged to the genus Porrocaecum; the remainder appeared to belong to the genus Anisakis. In all areas there was a progressive increase in incidence with increasing age of cod. In age-groups IV and V usually more than 70% of the cod were infected. Considerable local variation in incidence was observed in the Lockeport region. Cod were more heavily infected in inshore than in offshore waters. The samples from the Gulf of St. Lawrence showed less geographic variation in incidence than the Lockeport samples. The incidence in cod from the Magdalen Islands was noticeably lower than that in cod from the New Brunswick shore. Cod in the Gulf of St. Lawrence were infected to about the same extent as those from the offshore areas near Lockeport. The relation between local variations in incidence and the distribution of seals is briefly discussed.

Seasonal responses and their geographic variation in Chrysopa downesi: ecophysiological and evolutionary considerations

1981 ◽  
Vol 59 (3) ◽  
pp. 370-376 ◽  
Author(s):  
Maurice J. Tauber ◽  
Catherine A. Tauber
Keyword(s):  
New York ◽  
Geographic Variation ◽  
Thermal Thresholds ◽  
Preoviposition Period ◽  
Geographic Populations ◽  
Dark Green ◽  
Diapause Incidence ◽  
T Values ◽  
Two Populations ◽  
Seasonal Responses

A comparison of Chrysopa downesi strains from Montana and from New York indicates that they share several characteristics in their seasonal cycles: (1) a short-day – long-day requirement for diapause prevention, (2) dark green adult coloration all year round, (3) relatively high t values (lower thermal thresholds for development), and (4) sensitivity to photoperiod during the nondiapause preoviposition period.Responsiveness to prey differs between the two strains. Prey presence very slightly reduces diapause incidence and greatly shortens the nondiapause preoviposition period in the strain from Montana, whereas prey presence has little or no influence on the strain from the northeastern United States. The strains also differ in their ability to terminate diapause spontaneously; unlike the northeastern strain, a proportion of the northwestern strain ends diapause without an overt, external stimulus.The two populations of C. downesi thus share the two characteristics that are basic to the model of C. downesi's sympatric speciation from an ancestor like C. carnea. In contrast, the differences between the two populations in their responsiveness to prey presence parallels the geographic variation in C. carnea. We propose two alternate pathways (polyphyletic and monophyletic) for the evolution of the seasonal responses of the two geographic populations.

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