Size-specific resource use in juvenile little brown bats, Myotis lucifugus (Chiroptera: Vespertilionidae): Is there an ontogenetic shift?

1996 ◽  
Vol 74 (7) ◽  
pp. 1204-1210 ◽  
Author(s):  
Rick A. Adams
Keyword(s):  
Habitat Use ◽  
Relative Size ◽  
Myotis Lucifugus ◽  
Wing Size ◽  
Aspect Ratios ◽  
Significant Difference ◽  
Chi Squared ◽  
Morphological Transitions ◽  
High Degree ◽  
Little Brown Bats

This paper correlates shifts in habitat use and diet with morphological transitions occurring during postpartum growth and development (ontogenetic niche) in little brown bats, Myotis lucifugus. Juveniles were captured in mist nets as they foraged in different microhabitats that were defined and quantified using "clutter indices" ranging from 0 (least cluttered) to 5 (most cluttered). I analyzed fecal samples from captured individuals to assess diet. Chi-squared analyses showed that there was a significant difference in habitat use and diet among juveniles captured in early, mid, and late July. Juveniles with smaller wings foraged in the least cluttered habitats, whereas juveniles with larger wings foraged in habitats with a high degree of clutter. Juveniles with larger wings were captured in all microhabitats, whereas those with smaller wings were captured predominantly in open microhabitats. Juveniles with relatively higher aspect ratios and lower wing loadings used a greater diversity of habitats than those with lower aspect ratios and higher wing loadings. In addition, differences in diet were significant and correlated with wing size. My results suggest resource partitioning between juveniles as a function of wing size. These data have important implications regarding how relative size among juveniles may effect intraspecific structuring of populations.

scholarly journals Intraspecific variation in wing loading affects habitat use by little brown bats (Myotis lucifugus)

1995 ◽  
Vol 73 (1) ◽  
pp. 89-95 ◽  
Author(s):  
Matina C. Kalcounis ◽  
R. Mark Brigham
Keyword(s):  
Habitat Use ◽  
Body Mass ◽  
Selective Advantage ◽  
Myotis Lucifugus ◽  
Wing Loading ◽  
Interspecific Differences ◽  
Insect Trap ◽  
Flying Insects ◽  
The Relationship ◽  
Little Brown Bats

Morphological constraints have been linked to habitat partitioning by different species of animals. Interspecific differences have been explored, but less is known about the relationship between individuals of the same species. The purpose of this study was to determine if habitat use by little brown bats (Myotis lucifugus) varies with body mass of individuals. From aerodynamic theory, we predicted that bats with higher body mass will have higher wing loadings, should be less manoeuvrable, and thus tend to forage in areas where there are fewer obstacles to detect and avoid (clutter). Habitat was ranked into four zones based on the degree of clutter, and habitat use was assessed by measuring the time that males and non-reproductive, pregnant, lactating, postlactating, and artificially loaded females spent in each habitat zone. To test the assumption that a selective advantage accrues to bats foraging in clutter, we measured the availability of flying insects in cluttered and open habitats. Insect trap samples revealed a higher density of insect prey in more cluttered habitats. Body mass was positively correlated with wing loading. Overall, males were smaller than females with respect to mass and wing loading; however, these differences did not translate into differential habitat use. As predicted, there was a significant relationship between individual wing loading and habitat use, with heavier bats (greater wing loading) foraging in less cluttered areas.

Manoeuvrability and ecological segregation in the little brown (Myotis lucifugus) and Yuma (M. yumanensis) bats (Chiroptera: Vespertilionidae)

1986 ◽  
Vol 64 (9) ◽  
pp. 1878-1882 ◽  
Author(s):  
Hugh Aldridge
Keyword(s):  
Foraging Behavior ◽  
Performance Parameter ◽  
Myotis Lucifugus ◽  
Flight Performance ◽  
Wing Loading ◽  
Insectivorous Bats ◽  
Ecological Segregation ◽  
Significant Difference ◽  
High Degree

The abilities of two species of sympatric insectivorous bats, Myotis lucifugus and M. yumanensis, to negotiate a series of obstacle courses were measured. One hundred percent of the tested M. yumanensis were capable of negotiating their way through vertical strings 0.21 m apart, as compared with 30% of the tested M. lucifugus. A significant difference between the two species was found for this flight performance parameter, and this difference was found to be correlated with wing loading and wingspan. Myotis yumanensis has a lower wing loading and a lower wingspan than M. lucifugus, which probably explains the differences in manoeuvrability between the two species. An attempt was made to relate this difference to differences in the foraging behavior of the two species, but this was not possible, probably because of the high degree of morphological and behavioural overlap between the two species.

Risk of venous thromboembolism following surgical treatment of superficial venous incompetence

VASA ◽  
2017 ◽  
Vol 46 (6) ◽  
pp. 484-489 ◽  
Author(s):  
Tom Barker ◽  
Felicity Evison ◽  
Ruth Benson ◽  
Alok Tiwari
Keyword(s):  
Venous Thromboembolism ◽  
Varicose Vein ◽  
Lower Incidence ◽  
Varicose Veins ◽  
Secondary Data ◽  
Foam Sclerotherapy ◽  
Increased Risk ◽  
Significant Difference ◽  
Chi Squared ◽  
One Year

Abstract. Background: The invasive management of varicose veins has a known risk of post-operative deep venous thrombosis and subsequent pulmonary embolism. The aim of this study was to evaluate absolute and relative risk of venous thromboembolism (VTE) following commonly used varicose vein procedures. Patients and methods: A retrospective analysis of secondary data using Hospital Episode Statistics database was performed for all varicose vein procedures performed between 2003 and 2013 and all readmissions for VTE in the same patients within 30 days, 90 days, and one year. Comparison of the incidence of VTEs between procedures was performed using a Pearson’s Chi-squared test. Results: In total, 261,169 varicose vein procedures were performed during the period studied. There were 686 VTEs recorded at 30 days (0.26 % incidence), 884 at 90 days (0.34 % incidence), and 1,246 at one year (0.48 % incidence). The VTE incidence for different procedures was between 0.15–0.35 % at 30 days, 0.26–0.50 % at 90 days, and 0.46–0.58 % at one year. At 30 days there was a significantly lower incidence of VTEs for foam sclerotherapy compared to other procedures (p = 0.01). There was no difference in VTE incidence between procedures at 90 days (p = 0.13) or one year (p = 0.16). Conclusions: Patients undergoing varicose vein procedures have a small but appreciable increased risk of VTE compared to the general population, with the effect persisting at one year. Foam sclerotherapy had a lower incidence of VTE compared to other procedures at 30 days, but this effect did not persist at 90 days or at one year. There was no other significant difference in the incidence of VTE between open, endovenous, and foam sclerotherapy treatments.

scholarly journals Phenotypic Detection of Carbapenemase Production in Carbapenem-Resistant Enterobacteriaceae by Modified Hodge Test and Modified Strip Carba NP Test

2021 ◽  
Author(s):  
Nisha Patidar ◽  
Nitya Vyas ◽  
Shanoo Sharma ◽  
Babita Sharma
Keyword(s):  
Carbapenem Resistance ◽  
Nonparametric Test ◽  
Multidrug Resistant ◽  
Clinical Samples ◽  
Chi Square ◽  
Carbapenem Resistant ◽  
The Social ◽  
Significant Difference ◽  
High Degree ◽  
Carbapenem Resistant Enterobacteriaceae

Abstract Objective Carbapenems are last resort antibiotics for multidrug-resistant Enterobacteriaceae. However, resistance to carbapenem is increasing at an alarming rate worldwide leading to major therapeutic failures and increased mortality rate. Early and effective detection of carbapenemase producing carbapenem-resistant Enterobacteriaceae (CRE) is therefore key to control dissemination of carbapenem resistance in nosocomial as well as community-acquired infection. The aim of present study was to evaluate efficacy of Modified strip Carba NP (CNP) test against Modified Hodge test (MHT) for early detection of carbapenemase producing Enterobacteriaceae (CPE). Material and Methods Enterobacteriaceae isolated from various clinical samples were screened for carbapenem resistance. A total of 107 CRE were subjected to MHT and Modified strip CNP test for the detection of CPE. Statistical Analysis It was done on Statistical Package for the Social Sciences (SPSS) software, IBM India; version V26. Nonparametric test chi-square and Z-test were used to analyze the results within a 95% level of confidence. Results Out of 107 CRE, 94 (88%) were phenotypically confirmed as carbapenemase producer by Modified strip CNP test and 46 (43%) were confirmed by Modified Hodge Test (MHT). Thirty-eight (36%) isolates showed carbapenemase production by both MHT and CNP test, 56 isolates (52%) were CNP test positive but MHT negative, eight (7%) isolates were MHT positive but CNP test negative and five (5%) isolates were both MHT and CNP test negative. There is statistically significant difference in efficiency of Modified CNP test and MHT (p < 0.05). Conclusion Modified strip CNP test is simple and inexpensive test which is easy to perform and interpret and gives rapid results in less than 5 minutes. It has high degree of sensitivity and specificity. Modified strip CNP test shows significantly higher detection capacity for carbapenemase producers as compared with MHT.

scholarly journals Frequency-Following Response (FFR) in Military Pilots

2020 ◽  
Author(s):  
Graziela Maria Martins-Moreira ◽  
Alessandra Spada Durante
Keyword(s):  
Pure Tone Audiometry ◽  
Control Group ◽  
Study Group ◽  
Aircraft Accidents ◽  
Frequency Following Response ◽  
Significant Difference ◽  
Qualitative Variables ◽  
Chi Squared ◽  
The Right ◽  
Military Pilots

Abstract Introduction Good hearing in pilots, including central auditory skills, is critical for flight safety and the prevention of aircraft accidents. Pure tone audiometry alone may not be enough to assess hearing in the members of this population who, in addition to high noise levels, routinely face speech recognition tasks in non-ideal conditions. Objective To characterize the frequency-following response (FFR) of a group of military pilots compared with a control group. Methods Twenty military pilots in the Study Group and 20 non-pilot military personnel, not exposed to noise in their work, in the Control Group, all with normal hearing, aged between 30 and 40 years old, completed a questionnaire to assess their hearing habits, and their FFRs were measured with a /da/ syllable (duration 40 milliseconds, speed 10.9/s), at 80 dB NA in the right ear. All procedures were approved by the ethical committee of the institution. Statistical analysis was performed using the t-Student or Mann-Whitney tests for quantitative variables, and the Fisher or chi-squared tests for qualitative variables, and a value of p < 0.05 was considered to be statistically significant. Results There was no significant difference between the groups regarding auditory habits. In the FFR, wave amplitudes A (p = 0.01) and C (p = 0.04) were significantly lower in the Study Group. Conclusion Working as a military pilot can be a crucial factor in determining an individual's typical FFR pattern, demonstrated in the present study by statistically significant reductions in the amplitudes of the A and C waves.

Elevated mercury exposure and neurochemical alterations in little brown bats (Myotis lucifugus) from a site with historical mercury contamination

Ecotoxicology ◽  
2012 ◽  
Vol 21 (4) ◽  
pp. 1094-1101 ◽  
Author(s):  
Dong-Ha Nam ◽  
David Yates ◽  
Pedro Ardapple ◽  
David C. Evers ◽  
John Schmerfeld ◽  
...  
Keyword(s):  
Mercury Exposure ◽  
Myotis Lucifugus ◽  
Mercury Contamination ◽  
A Site ◽  
Little Brown Bats
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