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

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.

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

Canadian Journal of Zoology ◽

10.1139/cjz-2019-0137 ◽

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.

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Association between obstructive sleep apnea and persistent-postural perceptual dizziness

Journal of Vestibular Research ◽

10.3233/ves-201508 ◽

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.

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Genetic Variability, Correlation among Agronomic Traits, and Genetic Progress in a Sugarcane Diversity Panel

Agriculture ◽

10.3390/agriculture11060533 ◽

2021 ◽

Vol 11 (6) ◽

pp. 533

Author(s):

Fernanda Zatti Barreto ◽

Thiago Willian Almeida Balsalobre ◽

Roberto Giacomini Chapola ◽

Antonio Augusto Franco Garcia ◽

Anete Pereira Souza ◽

...

Keyword(s):

Genetic Parameters ◽

Mixed Model ◽

Agronomic Traits ◽

Average Increase ◽

Genetic Progress ◽

Breeding Programs ◽

Future Studies ◽

Diversity Panel ◽

Adjusted Means ◽

Historical Series

Sugarcane breeding programs require 15 years of experimentation to create more productive cultivars, and estimates of genetic progress can indicate the efficiency of breeding programs. In this study, we used a diversity panel, the Brazilian Panel of Sugarcane Genotypes (BPSG), with the following objectives: (i) to estimate, through a mixed model, the adjusted means and genetic parameters of ten traits evaluated over three harvest years; (ii) to estimate genotypic correlation among those traits; and (iii) to estimate genetic progress over six decades of breeding. The heritabilities ranged from 0.43 to 0.88, and we detected 42 significant correlations, 9 negative and 33 positive. Over six decades, the sucrose-related traits BRIX, POL%C, and POL%J showed an average increase per decade of 0.27 °Brix (0.26% and 0.31%, respectively). Stalk number, height, and weight of the plot, and cane and sucrose yields revealed average increases per decade of 3.27 stalks, 0.06 m, 9.42 kg, 11.22 t/ha, and 2.08 t/ha, respectively. The genetic progress of the main agronomic traits is discussed through a historical series of sugarcane genotypes present in the BPSG. The findings of this study could contribute to the management of new breeding strategies and allow for future studies of associative mapping.

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Diurnal Body Temperature and Rate of Passage of Loggers in Lions

Animals ◽

10.3390/ani10081388 ◽

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.

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Using the SWEPT Methodology for a Preliminary Wind Potential Estimation

ISRN Renewable Energy ◽

10.1155/2014/516964 ◽

2014 ◽

Vol 2014 ◽

pp. 1-7

Author(s):

Jean-Luc Menet

Keyword(s):

Wind Turbine ◽

Characteristic Curve ◽

Rayleigh Distribution ◽

Mean Velocity ◽

Technical Data ◽

Wind Potential ◽

Order Of Magnitude ◽

General Data ◽

The Mean ◽

A Site

The implantation of wind turbines generally follows a wind potential study which is made using specific numerical tools; the generated expenses are only acceptable for great projects. The purpose of the present paper is to propose a simplified methodology for the evaluation of the wind potential, following three successive steps for the determination of (i) the mean velocity, either directly or by the use of the most occurrence velocity (MOV); (ii) the velocity distribution coming from the single knowledge of the mean velocity by the use of a Rayleigh distribution and a Davenport-Harris law; (iii) an appropriate approximation of the characteristic curve of the turbine, coming from only two technical data. These last two steps allow calculating directly the electric delivered energy for the considered wind turbine. This methodology, called the SWEPT approach, can be easily implemented in a single worksheet. The results returned by the SWEPT tool are of the same order of magnitude than those given by the classical commercial tools. Moreover, everybody, even a “neophyte,” can use this methodology to obtain a first estimation of the wind potential of a site considering a given wind turbine, on the basis of very few general data.

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Lamb survival in two hill flocks

Animal Science ◽

10.1017/s0003356100033225 ◽

1959 ◽

Vol 1 (1) ◽

pp. 85-91 ◽

Cited By ~ 37

Author(s):

A. F. Purser ◽

G. B. Young

Keyword(s):

Birth Weight ◽

Survival Rate ◽

Age Structure ◽

Maternal Age ◽

Mortality Rates ◽

The Mean ◽

Lamb Survival

The effects of birth weight, maternal age and parity on survival of single lambs have been studied in a Blackface and a Welsh Mountain flock.In both flocks the maximum survival rate was found to occur among lambs with birth weights just above the mean. Mortality increased as lambs' birth weight increased or decreased from the optimum, but was especially heavy at the lower extreme of the range of birth weights.Mortality decreased with age of dam to 14·3% for lambs from 4- to 6-year-old Blackface ewes and to 9·4% for lambs of 3- to 4-year-old Welsh ewes. Ewes having their first lambs gave mortality rates twice as great as for the mature ewes in the same flocks. The lower chances of survival of first born lambs irrespective of dam's age accounts for the apparent trend of mortality with maternal age in the Blackface.Changes in mortality rates associated with variation in lamb's birth weight and with the age structure of the ewe flock were estimated. Possible means of improvement of survival rate are discussed.

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Comparing Sudden Stratospheric Warming Definitions in Reanalysis Data*

Journal of Climate ◽

10.1175/jcli-d-15-0004.1 ◽

2015 ◽

Vol 28 (17) ◽

pp. 6823-6840 ◽

Cited By ~ 25

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.

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

Journal of Endovascular Therapy ◽

10.1177/152660289800500309 ◽

1998 ◽

Vol 5 (3) ◽

pp. 240-246 ◽

Cited By ~ 9

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.

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The isotopic record at an alpine glacier and its implications for local climatic changes and isotopic homogenization processes

Journal of Glaciology ◽

10.3189/172756501781832601 ◽

2001 ◽

Vol 47 (156) ◽

pp. 147-151 ◽

Cited By ~ 17

Author(s):

He Yuanqing ◽

Wilfred H. Theakstone ◽

Yao Tandong ◽

Shi Yafeng

Keyword(s):

Equilibrium Line Altitude ◽

Temperature Variations ◽

Alpine Glacier ◽

Temperature Changes ◽

Natural Factors ◽

Air Temperatures ◽

Regional Temperature ◽

The Mean ◽

A Site ◽

The Relationship

AbstractStratigraphic variations of oxygen isotopes in the snow which accumulates during the winter at the Norwegian glacier Austre Okstindbreen are not entirely eliminated after 1–2 months of ablation in the following summer. The relationship between regional temperature changes and δ18O values in the snowpack is affected by many natural factors, but 1989/90 winter air temperatures were reflected in the snow which remained on Austre Okstindbreen at 1350 m a.s.l. in July 1990. There were many variations of δ18O values in the 4.1m of snow above the 1989 summer surface, but variations in the underlying firn were relatively small. Meltwater percolation modifies the initial variations of δ18O values in the snowpack. At a site below the mean equilibrium-line altitude on Austre Okstindbreen, increased isotopic homogenization within a 10 day period in July accompanied an increase of the mean δ18O value. Although the isotopic record at a temperate glacier is likely to be influenced by more factors than is that at polar glaciers, it can provide an estimate of the approximate trend of local temperature variations.

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Comparison of Clinical Features Between Patients with Positive and Negative Appendectomy

10.21203/rs.3.rs-117309/v1 ◽

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.

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