Head morphology of 1st and 5th instar nymphs of Triatoma circummaculata and Triatoma rubrovaria (Hemiptera, Reduviidae)

1999 ◽  
Vol 28 (4) ◽  
pp. 363-375 ◽  
Author(s):  
João A. da Rosa ◽  
José M.S. Barata ◽  
Mario Cilense ◽  
Francisco M. Belda Neto
Keyword(s):  
Head Morphology

scholarly journals Large-scale machine learning-based phenotyping significantly improves genomic discovery for optic nerve head morphology

2021 ◽  
Author(s):  
Babak Alipanahi ◽  
Farhad Hormozdiari ◽  
Babak Behsaz ◽  
Justin Cosentino ◽  
Zachary R. McCaw ◽  
...  
Keyword(s):  
Machine Learning ◽  
Optic Nerve ◽  
Optic Nerve Head ◽  
Large Scale ◽  
Head Morphology

Do researchers impact their study populations? Assessing the effect of field procedures in a long term population monitoring of sea kraits

2012 ◽  
Vol 33 (3-4) ◽  
pp. 365-372 ◽  
Author(s):  
Thomas Fauvel ◽  
François Brischoux ◽  
Marine Jeanne Briand ◽  
Xavier Bonnet
Keyword(s):  
Body Condition ◽  
New Caledonia ◽  
Stress Hormones ◽  
Population Level ◽  
Population Monitoring ◽  
Long Term Effects ◽  
Negative Effects ◽  
Short Term ◽  
Head Morphology

Long term population monitoring is essential to ecological studies; however, field procedures may disturb individuals. Assessing this topic is important in worldwide declining taxa such as reptiles. Previous studies focussed on animal welfare issues and examined short-term effects (e.g. increase of stress hormones due to handling). Long-term effects with possible consequences at the population level remain poorly investigated. In the present study, we evaluated the effects of widely used field procedures (e.g. handling, marking, forced regurgitation) both on short-term (hormonal stress response) and on long-term (changes in body condition, survival) scales in two intensively monitored populations of sea kraits (Laticauda spp.) in New Caledonia. Focusing on the most intensively monitored sites, from 2002 to 2012, we gathered approximately 11 200 captures/recaptures on 4500 individuals. Each snake was individually marked (scale clipping + branding) and subjected to various measurements (e.g. body size, head morphology, palpation). In addition, a subsample of more than 500 snakes was forced to regurgitate their prey for dietary analyses. Handling caused a significant stress hormonal response, however we found no detrimental long-term effect on body condition. Forced regurgitation did not cause any significant effect on both body condition one year later and survival. These results suggest that the strong short-term stress provoked by field procedures did not translate into negative effects on the population. Although similar analyses are required to test the validity of our conclusions in other species, our results suggest distinguishing welfare and population issues to evaluate the potential impact of population surveys.

scholarly journals A Genetic Epidemiologic Study of Candidate Genes Involved in the Optic Nerve Head Morphology

2012 ◽  
Vol 53 (3) ◽  
pp. 1485 ◽  
Author(s):  
Andrea C. Gasten ◽  
Wishal D. Ramdas ◽  
Linda Broer ◽  
Leonieke M. E. van Koolwijk ◽  
M. Kamran Ikram ◽  
...  
Keyword(s):  
Optic Nerve ◽  
Candidate Genes ◽  
Optic Nerve Head ◽  
Epidemiologic Study ◽  
Head Morphology ◽  
Genetic Epidemiologic Study

Optic nerve head morphology of the Eastern gray squirrel, Sciurus carolinensis

2004 ◽  
Vol 7 (3) ◽  
pp. 169-173
Author(s):  
Lindsay A. Kuester ◽  
Andras M. Komaromy ◽  
Dennis E. Brooks ◽  
Patricia A. Lewis ◽  
Fred Bennett ◽  
...  
Keyword(s):  
Optic Nerve ◽  
Optic Nerve Head ◽  
Sciurus Carolinensis ◽  
Gray Squirrel ◽  
Head Morphology ◽  
Eastern Gray Squirrel

scholarly journals Unimodal head-width distribution of the European eel (Anguilla anguilla L.) from the Zeeschelde does not support disruptive selection

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5773 ◽  
Author(s):  
Pieterjan Verhelst ◽  
Jens De Meyer ◽  
Jan Reubens ◽  
Johan Coeck ◽  
Peter Goethals ◽  
...  
Keyword(s):  
Anguilla Anguilla ◽  
Bimodal Distribution ◽  
Disruptive Selection ◽  
Head Width ◽  
European Eel ◽  
Unimodal Distribution ◽  
Single Location ◽  
Maturation Stages ◽  
Width Distribution ◽  
Head Morphology

Since the early 20th century, European eels (Anguilla anguilla L.) have been dichotomously classified into ‘narrow’ and ‘broad’ heads. These morphs are mainly considered the result of a differential food choice, with narrow heads feeding primarily on small/soft prey and broad heads on large/hard prey. Yet, such a classification implies that head-width variation follows a bimodal distribution, leading to the assumption of disruptive selection. We investigated the head morphology of 272 eels, caught over three consecutive years (2015–2017) at a single location in the Zeeschelde (Belgium). Based on our results, BIC favored a unimodal distribution, while AIC provided equal support for a unimodal and a bimodal distribution. Notably, visualization of the distributions revealed a strong overlap between the two normal distributions under the bimodal model, likely explaining the ambiguity under AIC. Consequently, it is more likely that head-width variation followed a unimodal distribution, indicating there are no disruptive selection pressures for bimodality in the Zeeschelde. As such, eels could not be divided in two distinct head-width groups. Instead, their head widths showed a continuum of narrow to broad with a normal distribution. This pattern was consistent across all maturation stages studied here.

scholarly journals Cadmium Bioaccumulation in Yellow Foxtail (Setaria glauca L. P. Beauv): Impact on Seed Head Morphology

2004 ◽  
Vol 3 (1) ◽  
Author(s):  
D Kosma ◽  
J Long ◽  
S Ebb
Keyword(s):  
Contaminated Soils ◽  
Significant Negative Correlation ◽  
Head Length ◽  
Contaminated Site ◽  
Seed Head ◽  
Setaria Glauca ◽  
Cadmium Bioaccumulation ◽  
Head Morphology ◽  
The Impact ◽  
Water Extractable

Yellow foxtail (Setaria glauca L. P. Beauv) growing on a cadmium-contaminated site was sampled to determine the extent of cadmium bioaccumulation in aerial tissues and the impact of cadmium on growth and development. Water-extractable Cd concentrations in the soil ranged from 5.0 to 18.0 mg L-1. Aerial tissues contained elevated concentrations of Cd (16-48 μg g-1 DW), with mean concentration ratios of >3.0. Since foxtail frequently colonizes disturbed sites, the bioaccumulation of Cd in aerial tissues of foxtail suggests that wildlife feeding upon this plant species could be exposed to elevated Cd levels. A significant negative correlation (r2=0.98) was observed between water-extractable Cd in the soil and seed head length in foxtail, indicative of an adverse effect of Cd on reproductive development. This correlation further suggests seed head length as a biomarker for soluble Cd in contaminated soils. KEYWORDS: Cadmium, bioaccumulation, biomarker, phytotoxicity

Head morphology and piscivory of European eels,Anguilla anguilla, predict their probability of infection by the invasive parasitic nematodeAnguillicoloides crassus

2015 ◽  
Vol 60 (10) ◽  
pp. 1977-1987 ◽  
Author(s):  
Josephine Pegg ◽  
Demetra Andreou ◽  
Chris F. Williams ◽  
J. Robert Britton
Keyword(s):  
Anguilla Anguilla ◽  
Head Morphology

scholarly journals Glucose Injections at Birth, Warmth and Placing at a Nurse Sow Improve the Growth of IUGR Piglets

Animals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 519 ◽  
Author(s):  
Maiken N. Engelsmann ◽  
Christian F. Hansen ◽  
Marlene N. Nielsen ◽  
Anders R. Kristensen ◽  
Charlotte Amdi
Keyword(s):  
Rectal Temperature ◽  
The Other ◽  
Intrauterine Growth ◽  
Glucose Levels ◽  
Newborn Piglets ◽  
Glucose Injection ◽  
Energy Supplementation ◽  
Head Morphology ◽  
On Farm ◽  
Maintain Body Temperature

Intrauterine growth-restricted piglets (IUGR) have a lower rectal temperature, whole-blood glucose, and lower glycogen storages at birth than normal piglets, giving them less energy to maintain body temperature and compete at the udder. The present paper investigated the effects of giving an energy supplementation three times after birth on rectal temperature, glucose levels, and growth until weaning in an on-farm trial. Eighty-eight newborn piglets were classified as IUGR (based on head morphology), placed under a heating lamp for one hour and allocated to one of four treatments—warmed water (WATER), glucose injection (GLUC), colostrum bolus (COLOS; porcine colostrum), and colostrum bolus and glucose injection (GLUC + COLOS)—before being placed at a nursing sow. Weight differences were found at day 21, with GLUC and GLUC + COLOS groups being the heaviest. Piglets in GLUC + COLOS had higher glucose levels at t = 3, 6, and 9 h compared to the other treatments (p = 0.027), but from t = 24 h and onwards, no difference was observed. For rectal temperature, no differences were observed. Collectively, these findings suggest that glucose injections at birth (i.e., as an energy source), one hour’s exposure to warmth and the placement of piglets with a nurse sow to reduce competition, enhance the growth of IUGR piglets.

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