Insular dwarfism in female Eastern Hog-nosed Snakes (Heterodon platirhinos; Dipsadidae) on a barrier island

2020 ◽  
Vol 98 (3) ◽  
pp. 157-164
Author(s):  
John P. Vanek ◽  
Russell L. Burke
Keyword(s):  
Resource Availability ◽  
Barrier Island ◽  
Limited Resource ◽  
Large Prey ◽  
Island Rule ◽  
Future Studies ◽  
Limited Availability ◽  
The Mean ◽  
Study Sites ◽  
Prey Items

The island rule postulates that the special ecological conditions on islands, such as limited resource availability, can cause populations of large-bodied animals to evolve smaller sizes and small-bodied populations to evolve larger sizes. Although support for the island rule is well documented (with notable exceptions and debate) in mammals and birds, similar trends are poorly explored in ectothermic vertebrates. As part of a larger study investigating the ecology of Eastern Hog-nosed Snakes (Heterodon platirhinos Latreille, 1801), we compared the mean and maximum sizes of a population from a barrier island (∼4 000 ha) to snakes on an adjacent larger island (∼363 000 ha) and two mainland sites (450 total snakes across all study sites). We did not observe a difference between the small and the large islands, but we did find differences between the smallest island and the mainland. Female snakes on the barrier island were 8% smaller than those on the mainland, and the female from the largest barrier island was 35% smaller than the largest documented H. platirhinos. In addition, we found that males did not exhibit dwarfism. We hypothesize that the observed dwarfism is a result of limited availability of large prey items and recommend that future studies distinguish between sexes in their analyses.

scholarly journals Non-parallel changes in songbird migration timing are not explained by changes in stopover duration

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8975
Author(s):  
Nicholas N. Dorian ◽  
Trevor L. Lloyd-Evans ◽  
J. Michael Reed
Keyword(s):  
Quantile Regression ◽  
Age Structure ◽  
Resource Availability ◽  
Average Increase ◽  
Stopover Duration ◽  
Future Studies ◽  
Migration Timing ◽  
The Mean ◽  
A Site ◽  
Songbird Migration

Shifts in the timing of animal migration are widespread and well-documented; however, the mechanism underlying these changes is largely unknown. In this study, we test the hypothesis that systematic changes in stopover duration—the time that individuals spend resting and refueling at a site—are driving shifts in songbird migration timing. Specifically, we predicted that increases in stopover duration at our study site could generate increases in passage duration—the number of days that a study site is occupied by a particular species—by changing the temporal breadth of observations and vise versa. We analyzed an uninterrupted 46-year bird banding dataset from Massachusetts, USA using quantile regression, which allowed us to detect changes in early-and late-arriving birds, as well as changes in passage duration. We found that median spring migration had advanced by 1.04 days per decade; that these advances had strengthened over the last 13 years; and that early-and late-arriving birds were advancing in parallel, leading to negligible changes in the duration of spring passage at our site (+0.07 days per decade). In contrast, changes in fall migration were less consistent. Across species, we found that median fall migration had delayed by 0.80 days per decade, and that changes were stronger in late-arriving birds, leading to an average increase in passage duration of 0.45 days per decade. Trends in stopover duration, however, were weak and negative and, as a result, could not explain any changes in passage duration. We discuss, and provide some evidence, that changes in population age-structure, cryptic geographic variation, or shifts in resource availability are consistent with increases in fall passage duration. Moreover, we demonstrate the importance of evaluating changes across the entire phenological distribution, rather than just the mean, and stress this as an important consideration for future studies.

Association between obstructive sleep apnea and persistent-postural perceptual dizziness

2021 ◽  
pp. 1-6
Author(s):  
Anand K. Bery ◽  
Jayson Lee Azzi ◽  
Andre Le ◽  
Naomi S. Spitale ◽  
Judith Leech ◽  
...  
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Sensitivity And Specificity ◽  
Berlin Questionnaire ◽  
Future Studies ◽  
Obstructive Sleep ◽  
Chronic Dizziness ◽  
Patients At Risk ◽  
The Mean ◽  
The Relationship

BACKGROUND: Obstructive sleep apnea (OSA) has been linked to vestibular dysfunction, but no prior studies have investigated the relationship between Persistent Postural Perceptual Dizziness (PPPD), a common cause of chronic dizziness, and OSA. OBJECTIVE AND METHODS: We determined the frequency of OSA in an uncontrolled group of PPPD patients from a tertiary dizziness clinic based on polysomnogram (PSG). We then assessed the sensitivity and specificity of common OSA questionnaires in this population. RESULTS: Twenty-five patients with PPPD underwent PSG (mean age 47, 60% female, mean BMI 29.5). A majority, or 56%, of patients were diagnosed with OSA, and in most, the OSA was severe. OSA patients were older (56 years versus 40 years, p = 0.0006) and had higher BMI (32 versus 26, p = 0.0078), but there was no clear gender bias (56% versus 64% female, p = 1.00). The mean sensitivity and specificity of the STOP BANG questionnaire for detecting OSA was 86% and 55%, respectively. Sensitivity and specificity of the Berlin Questionnaire was 79% and 45%, respectively. CONCLUSIONS: The prevalence of OSA was much higher in our small PPPD group than in the general population. Screening questionnaires appear to demonstrate good sensitivity to detect PPPD patients at risk of OSA in this small study. Future studies should confirm these findings and determine whether treatment of OSA improves symptoms in PPPD.

scholarly journals Potential Fertilization Capacity of Two Grapevine Varieties: Effects on Agricultural Production in Designation of Origin Areas in the Northwestern Iberian Peninsula

Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 961
Author(s):  
J. Antonio Cortiñas Rodríguez ◽  
María Fernández-González ◽  
Estefanía González-Fernández ◽  
Rosa A. Vázquez-Ruiz ◽  
F. Javier Rodríguez-Rajo ◽  
...  
Keyword(s):  
Airborne Pollen ◽  
Germination Rate ◽  
Pollen Viability ◽  
Weather Conditions ◽  
Triphenyl Tetrazolium Chloride ◽  
Tetrazolium Chloride ◽  
The Mean ◽  
Study Sites ◽  
Fertilization Capacity

In the present study, we analyzed the main parameters related with the potential fertilization ability of two grapevine varieties, Godello and Mencía, during the years 2017 and 2018. The research was carried out in two vineyards of the Galician winegrowing Designation of Origin areas of Ribeiro and Ribeira Sacra. Ten vines of each variety were selected for bunch and flower counting, pollen calculations, pollen viability studies by means of aceto-carmine (AC) stain and 2, 3, 5-triphenyl tetrazolium chloride (TTC) methods, and the determination of their germination rate. In all vineyards the 50% fruitset was reached, except for Godello in Cenlle during 2017. The mean coulure value was higher for Godello (40.5%) than for Mencía (31%). Analyzing the pollen production per plant and airborne pollen levels, we observed important discordances between them, which can be due to the influence of weather conditions and be related with self-pollination processes. We found important differences on pollen viability depending on the applied method and variety, with higher values for the AC method than the TTC for both varieties in all study plots, and higher values for Mencía variety than Godello. Regarding germination rates, we observed a marked reduction in 2017 with respect to 2018, in all study sites and for both varieties. The analyzed parameters were useful to explain the different productive abilities of Godello and Mencía varieties in the two studied bioclimatic regions of Ribeiro and Ribeira Sacra.

scholarly journals Diurnal Body Temperature and Rate of Passage of Loggers in Lions

Animals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1388
Author(s):  
Ted Friend ◽  
Giulia Corsini ◽  
Vincent Manero ◽  
Raffaella Cocco
Keyword(s):  
Body Temperature ◽  
Time Frame ◽  
Heat Lamp ◽  
Future Studies ◽  
Ambient Temperatures ◽  
Diurnal Patterns ◽  
Data Loggers ◽  
The Mean ◽  
African Lions ◽  
Circadian Patterns

The documentation of diurnal patterns in body temperature in lions could be important because disruption of circadian patterns can be a useful measure of distress. This study quantified changes in body temperature of seven African lions (Panthera leo) at 5 min intervals during cold conditions from noon until the ingested body temperature loggers were expelled the next day. Thirteen loggers were fed to 11 lions during their daily noon feeding, while ambient temperatures were also recorded using six data loggers. The lions had continuous access to their dens and exercise pens during the day but were restricted to their heavily bedded dens that also contained a heat lamp from 23:00 until 08:00 the next day. Body temperatures averaged 37.95 ± 0.42 °C at 15:50, and 36.81 ± 0.17 °C at 06:50 the next day, 30 min before the first loggers passed from a lion, and were significantly different (t-test, t = 8.09, df = 6, p < 0.0003). The mean duration for the time of passage was 22 ± 2.69 (h ± SD), so future studies using the noninvasive feeding of temperature loggers need to consider that time frame.

scholarly journals Comparing Sudden Stratospheric Warming Definitions in Reanalysis Data*

2015 ◽  
Vol 28 (17) ◽  
pp. 6823-6840 ◽  
Author(s):  
Froila M. Palmeiro ◽  
David Barriopedro ◽  
Ricardo García-Herrera ◽  
Natalia Calvo
Keyword(s):  
Seasonal Cycle ◽  
Winter Season ◽  
Reanalysis Data ◽  
Sudden Stratospheric Warming ◽  
Pronounced Increase ◽  
Future Studies ◽  
Common Peak ◽  
Before And After ◽  
The Mean ◽  
Large Case

Abstract Sudden stratospheric warmings (SSWs) are characterized by a pronounced increase of the stratospheric polar temperature during the winter season. Different definitions have been used in the literature to diagnose the occurrence of SSWs, yielding discrepancies in the detected events. The aim of this paper is to compare the SSW climatologies obtained by different methods using reanalysis data. The occurrences of Northern Hemisphere SSWs during the extended-winter season and the 1958–2014 period have been identified for a suite of eight representative definitions and three different reanalyses. Overall, and despite the differences in the number and exact dates of occurrence of SSWs, the main climatological signatures of SSWs are not sensitive to the considered reanalysis. The mean frequency of SSWs is 6.7 events decade−1, but it ranges from 4 to 10 events, depending on the method. The seasonal cycle of events is statistically indistinguishable across definitions, with a common peak in January. However, the multidecadal variability is method dependent, with only two definitions displaying minimum frequencies in the 1990s. An analysis of the mean signatures of SSWs in the stratosphere revealed negligible differences among methods compared to the large case-to-case variability within a given definition. The stronger and more coherent tropospheric signals before and after SSWs are associated with major events, which are detected by most methods. The tropospheric signals of minor SSWs are less robust, representing the largest source of discrepancy across definitions. Therefore, to obtain robust results, future studies on stratosphere–troposphere coupling should aim to minimize the detection of minor warmings.

scholarly journals Carotid Plaque Characterization Using Digital Image Processing and its Potential in Future Studies of Carotid Endarterectomy and Angioplasty

1998 ◽  
Vol 5 (3) ◽  
pp. 240-246 ◽  
Author(s):  
Giorgio M. Biasi ◽  
Paolo M. Mingazzini ◽  
Lucia Baronio ◽  
Maria Rosa Piglionica ◽  
Stefano A. Ferrari ◽  
...  
Keyword(s):  
Cerebral Infarction ◽  
Carotid Endarterectomy ◽  
Carotid Plaque ◽  
Screening Tool ◽  
Brain Infarction ◽  
Carotid Stent ◽  
Plaque Characterization ◽  
Duplex Scan ◽  
Future Studies ◽  
The Mean

Purpose: To corroborate the validity of a computerized methodology for evaluating carotid lesions at risk for stroke based on plaque echogenicity. Methods: The records of 96 carotid endarterectomy patients (59 men; median age 69.5 years, range 52 to 83) with stenoses > 50% were studied retrospectively. Forty-one patients (43%) had been symptomatic preoperatively. All patients had undergone computed tomography (CT) to detect infarction in the carotid territory and a duplex scan to measure carotid stenosis. Plaque echogenicity was analyzed by computer, expressing the echodensity in terms of the gray scale median (GSM). The incidence of CT-documented cerebral infarction was analyzed in relation to symptomatology, percent stenosis, and echodensity. Results: Symptoms correlated well with CT evidence of brain infarction: 32% of symptomatic patients had a positive CT scan versus 16% for asymptomatic plaques (p = 0.076). The mean GSM value was 56 ± 14 for plaques associated with negative CT scans and 38 ± 13 for plaques from patients with positive scans (p < 0.0001). However, there was no difference in the GSM value between plaques with > or < 70% stenosis. Furthermore, the incidence of CT infarction was 40% in the cerebral territory of carotid plaques with a GSM value < 50 and only 9% in those with a GSM > 50 (p < 0.001). Conclusions: Computerized analysis of plaque echogenicity appears to provide clinically useful data that correlates with the incidence of cerebral infarction and symptoms. This method of analyzing plaque echolucency could be used as a screening tool for carotid stent studies to identify high-risk lesions better suited to conventional surgical treatment.

scholarly journals Resource Utilization and Costs of Care prior to ART Initiation for Pediatric Patients in Zambia

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Hari S. Iyer ◽  
Callie A. Scott ◽  
Deophine Lembela Bwalya ◽  
Gesine Meyer-Rath ◽  
Crispin Moyo ◽  
...  
Keyword(s):  
Pediatric Patients ◽  
Blood Chemistry ◽  
Full Blood Count ◽  
National Guidelines ◽  
Art Initiation ◽  
Time To Initiation ◽  
The Mean ◽  
Study Sites ◽  
Cd4 Percentage ◽  
Mean Cost

Objective. We estimated time to initiation, outpatient resource use, and costs of outpatient care during the 6 months prior to ART initiation for HIV-infected pediatric patients in Zambia.Methods. We enrolled 1,102 children who initiated ART at <15 years of age between 2006 and 2011 at 5 study sites. Of these, 832 initiated ART ≤6 months after first presenting to care at the study sites. Data on time in care and resources utilized during the 6 months prior to ART initiation were extracted from patient medical records. Costs were estimated from the provider’s perspective and are reported in 2011 USD.Results. For the patients who initiated ART ≤6 months after presenting to care, median age at presentation to care was 3.9 years; median CD4 percentage was 13%. Median time to ART initiation was 26 days. Patients made, on average, 2.38 clinic visits prior to ART initiation and received 0.81 CD4 tests, 0.74 full blood count tests, and 0.49 blood chemistry tests. The mean cost of pre-ART care was $20 per patient.Conclusions. Zambian pediatric patients initiating ART ≤6 months after presenting to care do so quickly, utilize fewer resources than mandated by national guidelines, and accrue low costs.

scholarly journals Comparison of Clinical Features Between Patients with Positive and Negative Appendectomy

2020 ◽  
Author(s):  
Guner Cakmak ◽  
Baris Mantoglu ◽  
Emre Gonullu ◽  
Kayhan Ozdemir ◽  
Burak Kamburoglu
Keyword(s):  
Acute Appendicitis ◽  
Clinical Features ◽  
Total Bilirubin ◽  
Negative Appendectomy ◽  
C Reactive Protein ◽  
Future Studies ◽  
Female Patients ◽  
Reactive Protein ◽  
Male Patients ◽  
The Mean

Abstract Background: The objective of this study was to retrospectively compare clinical features and prognostic values between the patients who were referred to the general surgery clinic of our hospital with the presumed diagnosis of acute appendicitis and underwent positive or negative appendectomy.Methods: Patients were divided into two groups as positive (PA) (n:362) and negative appendectomy (NA) (n:284) and the data obtained were compared between these two groups.Laboratory investigations were performed in all patients, and white blood cell (WBC), mean platelet volume (MPV), neutrophils count (NEU), neutrophils (%) (NEU%), C-reactive protein (CRP) and total bilirubin (TBIL) values were studied.Results: The mean MPV value was found as 7.88 fl in PA groups and 8.09 fl in NA group, and the mean MPV value was not statistically significantly difference in PA group, compared to NA groups (p=0.012). Laboratory parameters were also compared between genders. Accordingly, the mean MPV value was statistically significantly higher in female patients compared to male patients in PA group (p = 0.04). The mean TBIL value was 0.97 mg/dl in PA group and 0.69 mg/dl in NA group, and the mean TBIL value was statistically significantly higher in PA group (p< 0.001). Finally, TBIL value was statistically significantly lower in female patients compared to male patients in NA and PA group (p < 0.05).Conclusions: According to the results of our study, MPV and T. BIL values differ in PA and NA groups depending on gender. Therefore, these values may not be used as specific biomarkers in predicting positive acute appendicitis. We believe that these results will contribute to the literature and will be guiding for future studies.

scholarly journals Soil organic carbon stocks are systematically overestimated by misuse of the parameters bulk density and stone content

2016 ◽  
Author(s):  
Christopher Poeplau ◽  
Cora Vos ◽  
Axel Don
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Bulk Density ◽  
Agricultural Soils ◽  
Soil Layer ◽  
Future Studies ◽  
Soil Organic Carbon Stocks ◽  
Soc Stock ◽  
The Mean ◽  
Soc Stocks

Abstract. Estimation of soil organic carbon (SOC) stocks requires estimates of the carbon content, bulk density, stone content and depth of a respective soil layer. However, different application of these parameters could introduce a considerable bias. Here, we explain why three out of four frequently applied methods overestimate SOC stocks. In stone rich soils (> 30 Vol. %), SOC stocks could be overestimated by more than 100 %, as revealed by using German Agricultural Soil Inventory data. Due to relatively low stone content, the mean systematic overestimation for German agricultural soils was 2.1–10.1 % for three different commonly used equations. The equation ensemble as re-formulated here might help to unify SOC stock determination and avoid overestimation in future studies.

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