987 resultados para Chirundina streetsii, female, length


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Toxaphene contamination of minke whales (Balaenoptera acutorostrata) from North Atlantic waters was examined for the first time. Total toxaphene and SumCHB (sum of 11 chlorobornanes) concentrations in blubber samples ranged from 170 ± 110 and 41 ± 39 ng/g lipid weight (l.w.) for female minke whales from southeastern Greenland to 5800 ± 4100 and 1100 ± 780 ng/g l.w. for males from the North Sea, respectively. Very large variations in toxaphene concentrations among sampling areas were observed suggesting a spatial segregation of minke whales. However, much of the apparent geographical discrimination was explained by the seasonal fluctuation of animal fat mass. Patterns of CHBs in males revealed that recalcitrant CHBs were in higher proportions in animals from the more easterly areas than in animals from the more westerly areas. This trend may be influenced by the predominance of the US, over the European, input of toxaphene to North Atlantic waters.

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Determination of when and where animals feed and how much they consume is fundamental to understand their ecology and role in ecosystems. However, the lack of reliable data on feeding habits of wild animals, and particularly in marine endotherms, attests to the difficulty in doing this. A promising recent development proposes using a Hall sensor-magnet System - the inter-mandibular angle sensor (IMASEN) attached to animals' jaws to elucidate feeding events. We conducted trials on captive pinnipeds by feeding IMASEN-equipped animals with prey to examine the utility of this system. Most feeding events were clearly distinguishable from other jaw movements; only small prey items might not be resolved adequately. Based on the results of this study we examined feeding events from free-ranging Weddell seals fitted with IMASENs and dead-reckoners during December 2003 at Drescher Inlet (Riiser Larsen Ice Shelf, eastern Weddell Sea coast), and present data on prey capture and ingestion in relation to the three-dimensionalmovement patterns of the seals. A total of 19 Weddell seals were immobilised by using a combination of ketamine, xylazine, and diazepam. Eight seals were drugged once, six two times, and two and three were drugged three and four times each, coming to a total of 38 immobilisation procedures. Narcoses were terminated with yohimbine (doi:10.1594/PANGAEA.438931).

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Adult male and female Weddell seals (Leptonychotes weddellii) were fitted with Time-depth recorders (TDR) at Drescher Inlet (Riiser Larsen Ice Shelf), eastern Weddell Sea coast, in February 1998. Eight of 15 data sets were selected for analyses to investigate the seals' foraging behaviour (doi:10.1594/PANGAEA.511465, doi:10.1594/PANGAEA.511454, doi:10.1594/PANGAEA.511456, doi:10.1594/PANGAEA.511457, doi:10.1594/PANGAEA.511459, doi:10.1594/PANGAEA.511462, doi:10.1594/PANGAEA.511466, doi:10.1594/PANGAEA.511467). These data sets provided simultaneous dive records of eight seals over eight days. The seals primarily foraged within two depth layers, these being from the sea surface to 160 m where temperature and salinity varied considerably, and from 340 to 450 m near the bottom where temperature was lowest and salinity highest, with little variation. While pelagic and benthic diving occurred during daylight, the seals foraged almost exclusively in the upper water column at night. Trawling during daytime confirmed that Pleuragramma antarcticum were by far the most abundant fish both in the pelagial and close to the bottom. Pelagic night-hauls at 110-170 m depth showed highly variable biomass of P. antarcticum with a peak at around midnight. The temporal changes in the local abundance of P. antarcticum, particularly in the pelagial, may explain the trends in the seals' pelagic and benthic foraging activities. This is the first study which describes the jaw movements of a hunting seal which are presumably indicative of feeding events. Trophic links from the Weddell seal to fish, zooplankton and krill, Euphausia superba, are discussed. Another seven data sets did not overlap substantially with the selected time frame (doi:10.1594/PANGAEA.511458, doi:10.1594/PANGAEA.511460, doi:10.1594/PANGAEA.511464, doi:10.1594/PANGAEA.511468, doi:10.1594/PANGAEA.511469, doi:10.1594/PANGAEA.511453, doi:10.1594/PANGAEA.511463). A total of 25 Weddell seals were immobilised during the study period using a combination of ketamine, xylazine, and diazepam. Seven seals were drugged once, 15 seals two times, and three were drugged three times, coming to a total of 46 immobilisation procedures. Narcoses were terminated with yohimbine (doi:10.1594/PANGAEA.438933).

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Swordtail fish (Poeciliidae: genus Xiphophorus) are a paradigmatic case of sexual selection by sensory exploitation. Female preference for males with a conspicuous “sword” ornament is ancestral, suggesting that male morphology has evolved in response to a preexisting bias. The perceptual mechanisms underlying female mate choice have not been identified, complicating efforts to understand the selection pressures acting on ornament design. We consider two alternative models of receiver behavior, each consistent with previous results. Females could respond either to specific characteristics of the sword or to more general cues, such as the apparent size of potential mates. We showed female swordtails a series of computer-altered video sequences depicting a courting male. Footage of an intact male was preferred strongly to otherwise identical sequences in which portions of the sword had been deleted selectively, but a disembodied courting sword was less attractive than an intact male. There was no difference between responses to an isolated sword and to a swordless male of comparable length, or between an isolated sword and a homogenous background. Female preference for a sworded male was abolished by enlarging the image of a swordless male to compensate for the reduction in length caused by removing the ornament. This pattern of results is consistent with mate choice being mediated by a general preference for large males rather than by specific characters. Similar processes may account for the evolution of exaggerated traits in other systems.

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In this paper, a reverse-transcriptase PCR-based protocol suitable for efficient expression analysis of multigene families is presented. The method combines restriction fragment length polymorphism (RFLP) technology with a gene family-specific version of mRNA differential display and hence is called "RFLP-coupled domain-directed differential display. "With this method, expression of all members of a multigene family at many different developmental stages, in diverse tissues and even in different organisms, can be displayed on one gel. Moreover, bands of interest, representing gene family members, are directly accessible to sequence analysis, without the need for subcloning. The method thus enables a detailed, high-resolution expression analysis of known gene family members as well as the identification and characterization of new ones. Here the technique was used to analyze differential expression of MADS-box genes in male and female inflorescences of maize (Zea mays ssp. mays). Six different MADS-box genes could be identified, being either specifically expressed in the female sex or preferentially expressed in male or female inflorescences, respectively. Other possible applications of the method are discussed.

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The present study was designed to determine the magnitude of the relationship between amount, frequency, and length of shift work completed by female transportation employees and the number, degree, and extent of problems related to physical, menstrual and psychological health including depression. It was hypothesized that workers that are employed in areas such as transportation who are working shift work on a regular basis place themselves at higher risk for developing health or psychosocial related effects. These health related outcomes can have a profound impact on an employee’s job performance, daily functioning, and personal life. The present study sought to understand the potential relationship between working shift work and higher disturbances to the bodies’ natural functioning. The present study has the potential for explaining new ways to decrease the risk factors for those working shift work by contributing to the overall understanding of this multifaceted relationship. This study has many important findings and implications. This study has implications for explaining that the effects of disturbances to the circadian rhythm as a result of certain shift work schedules can result in ill-related health effects. Additionally, this study sought to challenge limitations to current research that has been conducted on the topic as the majority of studies have been performed on men. The overall purpose of the study was to gain a better understanding of the negative effects of shift work on females working within the transportation industry. This study sought to explain the health implications specifically for female workers as fewer studies have been conducted with gender as a main effect in the analysis. The present study suggests that due to the circadian rhythm controlling hormone secretion within the body, disturbances to its natural rhythm can have additional effects on female cycles such as menstruation. Overall, this study offers implications for further research on females working shift work and highlights the continued importance for further exploration into recent developments. These implications have the potential to further our current understanding of the relationship between shift work and ill-health effects, particularly the factors that women face.

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Human pyruvate dehydrogenase complex (PDC) catalyzes a key step in the generation of cellular energy and is composed by three catalytic elements (E1, E2, E3), one structural subunit (E3-binding protein), and specific regulatory elements, phosphatases and kinases (PDKs, PDPs). The E1α subunit exists as two isoforms encoded by different genes: PDHA1 located on Xp22.1 and expressed in somatic tissues, and the intronless PDHA2 located on chromosome 4 and only detected in human spermatocytes and spermatids. We report on a young adult female patient who has PDC deficiency associated with a compound heterozygosity in PDHX encoding the E3-binding protein. Additionally, in the patient and in all members of her immediate family, a full-length testis-specific PDHA2 mRNA and a 5′UTR-truncated PDHA1 mRNA were detected in circulating lymphocytes and cultured fibroblasts, being bothmRNAs translated into full-length PDHA2 and PDHA1 proteins, resulting in the co-existence of both PDHA isoforms in somatic cells.Moreover, we observed that DNA hypomethylation of a CpG island in the coding region of PDHA2 gene is associatedwith the somatic activation of this gene transcription in these individuals. This study represents the first natural model of the de-repression of the testis-specific PDHA2 gene in human somatic cells, and raises some questions related to the somatic activation of this gene as a potential therapeutic approach for most forms of PDC deficiency.

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Analysis of the reproductive system of female vampire squid to determine reproductive strategy and fecundity of vampire squid, accessioned in the Santa Barbara Museum of Natural History and collected in 60, 70s from off southern California.

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Thesis (Master's)--University of Washington, 2016-06

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Introduction/Purpose: The role of impact loading activity on bone mass is well established; however, there are little data on the effects of exercise on bone geometry and indices of bone strength. The primary purpose of this study was to compare indices of bone strength at the proximal femur (PF) between elite premenarcheal gymnasts (N = 30) and age-matched controls (N = 30). Methods: Structural properties of the proximal femur were derived from the hip analyses program and included measurement of subperiosteal width, endosteal diameter, cross-sectional area, bone mineral density, cross-section moment of inertia (CSMI), and section modulus (Z). These parameters were measured for two regions of the PF: the narrow neck (NN), and the shaft (S). In addition, a strength index (S-SI) was calculated at the shaft by dividing the Z at the shaft by the femur length. A secondary purpose was to compare bone mineral content (BMC) values at the total body, lumbar spine, and three sites at the PF (neck, trochanter, and total) between the groups. All dependent values were compared adjusting for height and weight using an ANCOVA procedure and for relative lean body mass post hoc. Results: The gymnasts had significantly greater size-adjusted strength indices (CSMI, Z, and SI) at the NN and S. Gymnasts also had significantly greater size-adjusted BMC at all sites investigated. However, these differences disappeared when adjusted for relative lean body mass. Conclusion: When adjusted for body size, gymnasts had significantly greater indices of both axial strength and bending strength at the NN region of the PF and S, as well as a greater bone SI at the femoral shaft. These differences may be related to greater relative lean body mass attained in gymnastics training.

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Prenatal exposure to testosterone has been hypothesised to effect lateralization by influencing cell death in the foetal brain. Testosterone binds to the X chromosome linked androgen receptor, which contains a polymorphic polyglutamine CAG repeat, the length of which is positively correlated with testosterone levels in males, and negatively correlated in females. To determine whether the length of the androgen receptor mediates the effects of testosterone on laterality, we examined the association between the number of CAG repeats in the androgen receptor gene and handedness for writing. Association was tested by adding regression terms for the length of the androgen receptor alleles to a multi-factorial-threshold model of liability to left-handedness. In females we found the risk of left-handedness was greater in those with a greater number of repeats (p=0.04), this finding was replicated in a second independent sample of female twins (p=0.014). The length of the androgen receptor explained 6% of the total variance and 24% of the genetic variance in females. In males the risk of left-handedness was greater in those with fewer repeats (p=0.02), with variation in receptor length explaining 10% of the total variance and 24% of the genetic variance. Thus, consistent with Witelson's theory of testosterone action, in all three samples the likelihood of left handedness increased in those individuals with variants of the androgen receptor associated with lower testosterone levels.

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The importance of endogenous rhythms in the photoperiodic control of the annual reproduction cycle in female rainbow trout was investigated. The effect of photoperiod regimes on the different stages of maturation was assessed by recording the timing of ovulation and from quantifying associated changes in serum oestradiol-17,testosterone and total calcium. Maintained under constant 6L:18D and constant temperature for up to four years, rainbow trout exhibited an endogenous rhythm of maturation with a periodicity of approximately one year. This rhythm of maturation appears to be driven by an autonomous circannual oscillator or clock which can be dissociated from the neuroendocrine mechanisms controlling gonadal maturation. Under conditions of constant 18L:6D or LL the periodicity of the maturation rhythm was 5.5-6 months; it is suggested that this periodicity may be caused by a splitting or uncoupling of at least two circannual clocks involved in the control of maturation. Abrupt changes in the length of the photoperiod act as a zeitgeber to entrain the endogenous rhythm of maturation. Whether the timing of maturation is advanced or delayed depends primarily on the direction of the change in photoperiod and its timing in relation to the phase of the rhythm, with the magnitude of the alteration in photoperiod having only a supplementary effect. The effect of specific changes in photoperiod on the entrainment of the maturation cycle can be described in terms of a phase-response curve. Photic information is transduced, probably by the pineal gland, into a daily rhythm of melatonin; exposure of rainbow trout to skeleton and resonance photoperiod regimes indicated that daylength measurement is effected by endogenous circadian clock(s) rather than by hour-glass mechanisms. A gating mechanism is closely associated with the circannual clock which determines the timing of onset of maturation in virgin female rainbow trout, only allowing fish that have attained a threshold stage of development to undergo gonadal maturation. Collectively the results support the hypothesis that the female rainbow trout exhibits an endogenous circannual rhythm of maturation which can be entrained by changes in photoperiod.