129 research outputs found
Endothelium and endothelial dysfunction - health implications and risk for cardiovascular diseases
The endothelium forms the lining of tunica intima, a single cell layer at the interface between the blood and the extravascular fluid spaces. Not many years ago ther endothelium was considered a simple structural barrier that merely modulated permeation through the vessel wall by providing pores of appropriate size. Largely as a result of progress in tissue culture technology, we now know that endothelial cells accomplish a long list of metabolic functions.Ендотелій одношаровий пласт плоских клітин мезенхимного походження, що вистилає внутрішню поверхню кровоносних і лімфатичних судин, серцевих порожнин. Ще недавно ендотелій вважався простим структурним бар’єром, який просто модулював проникнення речовин через стінку сосуду, забезпечуючи пори відповідного розміру. Багато в чому в результаті прогресу в технології культивування тканин, в даний час показано, що ендотеліальні клітини здійснюють численні метаболічні функції.Эндотелий — однослойный пласт плоских клеток мезенхимного происхождения, выстилающий внутреннюю поверхность кровеносных и лимфатических сосудов, сердечных полостей. Еще недавно эндотелий считался простым структурным барьером, который просто модулировал проникновение веществ через стенку сосуда, обеспечивая поры соответствующего размера. Во многом в результате прогресса в технологии культивирования тканей, в настоящее время показано, что эндотелиальные клетки осуществляют многочисленные метаболические функции
The median nerve in the carpal tunnel
A study of the variations of the course and branching pattern of the median
nerve within the carpal tunnel were carried out on 60 wrists from 30 fresh
cadavers autopsied in the Department of Forensic Medicine of Jagiellonian
University Medical College. The results were compared with the literature. The
study confirmed that the extraligamentous type of motor branch variation is
most common. The transligamentous course of the nerve is of special importance:
it is usually accompanied by hypertrophic muscle, and the nerve hidden
within this muscle can easily be cut during transection of the retinaculum. The
results proved the necessity of approaching the median nerve from the ulnar
side when opening the carpal tunnel. (Folia Morphol 2011; 70, 1: 41-46
Daily Activity Patterns of Two Co-Occurring Tropical Satyrine Butterflies
Adult males and females of many insect species are expected to adjust their daily activity pattern in order to avoid stressful climatic conditions and increase the chances to encounter sexual partners. Using scan sampling methods associated with focal individual observations it was found that two satyrine butterflies of similar size and morphology, Hermeuptychia hermes (Fabricius) (Leptidoptera: Nymphalidae) and Paryphthimoides phronius (Godart), show completely different daily activity patterns on forest edges in southeastern Brazil. Hermeuptychia hermes presents one abundance peak in the morning and another in the late afternoon, while P. phronius abundance peaks in the mid-day, remaining stable until 1700 h. This difference is probably due to the occurrence of territorial behavior in the later species. The beginning of territorial defense by P. phronius males coincided with the time of new-born female activity. However, newly hatched females were not sexually receptive. The afternoon territoriality in male P. phronius may be in part related to mate acquisition. However, why the abundance of H. hermes decreases when the abundance of P. phronius increases is less clear
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Crepuscular Mating Aggregations in Certain Ormia1 and Sitophagat
The tachinid species Ormia Dominicana, Ormia lineifrons, and Sitophaga aurigera were observed to aggregate atop 2 towers in central Florida shortly after sunset. The activity period for each species was brief, and that of 0. dominicana was temporally separated from that of S. aurigera. Aggregations occasionally exceeded 100 individuals of a species and were predominantly composed of males. Although no matings were seen, it is presumed that this behavior facilitates mating. The behavior of these flies was typical of insects at a waiting station. Eucelatoria rubentis and the anthomyiids Pegomyia affinis and Pegomyia gopheri were occasionally collected from the towers.Keywords: Sitophaga, Mating, OrmiaKeywords: Sitophaga, Mating, Ormi
The Presence–Absence Situation and Its Impact on the Assemblage Structure and Interspecific Relations of Pronophilina Butterflies in the Venezuelan Andes (Lepidoptera: Nymphalidae)
Assemblage structure and altitudinal patterns of Pronophilina, a species-rich group of Andean butterflies, are compared in El Baho and Monte Zerpa, two closely situated and ecologically similar Andean localities. Their faunas differ only by the absence of Pedaliodes ornata Grose-Smith in El Baho. There are, however, important structural differences between the two Pronophilina assemblages. Whereas there are five co-dominant species in Monte Zerpa, including P. ornata, Pedaliodes minabilis Pyrcz is the only dominant with more than half of all the individuals in the sample in El Baho. The absence of P. ornata in El Baho is investigated from historical, geographic, and ecological perspectives exploring the factors responsible for its possible extinction including climate change, mass dying out of host plants, and competitive exclusion. Although competitive exclusion between P. ornata and P. minabilis is a plausible mechanism, considered that their ecological niches overlap, which suggests a limiting influence on each other’s populations, the object of competition was not identified, and the reason of the absence of P. ornata in El Baho could not be established. The role of spatial interference related to imperfect sexual behavioral isolation is evaluated in maintaining the parapatric altitudinal distributions of three pairs of phenotypically similar and related species of Pedaliodes, Corades, and Lymanopoda
Multiscale models for movement in oriented environments and their application to hilltopping in butterflies
Hilltopping butterflies direct their movement in response to topography, facilitating mating encounters via accumulation at summits. In this paper, we take hilltopping as a case study to explore the impact of complex orienteering cues on population dynamics. The modelling employs a standard multiscale framework, in which an individual's movement path is described as a stochastic 'velocity-jump' process and scaling applied to generate a macroscopic model capable of simulating large populations in landscapes. In this manner, the terms and parameters of the macroscopic model directly relate to statistical inputs of the individual-level model (mean speeds, turning rates and turning distributions). Applied to hilltopping in butterflies, we demonstrate how hilltopping acts to aggregate populations at summits, optimising mating for low-density species. However, for abundant populations, hilltopping is not only less effective but also possibly disadvantageous, with hilltopping males recording a lower mating rate than their non-hilltopping competitors. © 2013 Springer Science+Business Media Dordrecht
Identification and Biosynthesis of Novel Male Specific Esters in the Wings of the Tropical Butterfly, Bicyclus martius sanaos
COURTSHIP BEHAVIOR OF THE GULF FRITILLARY AGRAULIS-VANILLAE NYMPHALIDAE
Volume: 38Start Page: 23End Page: 3
Female iridescent colour ornamentation in a butterfly that displays mutual ornamentation : is it a sexual signal?
In species wherein males display elaborate sexually selected traits or ornaments, conspecific females may also express these traits in full or partial form. This is called mutual ornamentation, and the co-occurrence of such traits in males and females remains poorly understood. In many sulphur butterflies (subfamily Coliadinae), males have a brilliant ultraviolet (UV) iridescence on their dorsal wing surfaces that functions as a sexual signal in courtship. In some of these sulphurs, such as the large grass yellow, Eurema hecabe, females also display dorsal iridescent patches, albeit smaller, restricted to the forewings and less bright than the male's, but the reasons for its occurrence in females are unknown. Here we present a study testing two functional hypotheses for the female UV-reflecting patch: an antiharassment hypothesis and a male mate choice hypothesis. The daily activity pattern of this species suggests that males are most likely to harass or choose among females from midday on. Observations made at this time of day on the characteristics of females related to male courtship duration suggest that males may preferentially court females with a large UV patch. Experiments with colour-manipulated models also suggest that males court with equal intensity females with and without a basal UV patch. Taken altogether the results provide no support for the antiharassment hypothesis. Because support for the male mate choice hypothesis was relatively weak and because of the limited potential for selection on female coloration due to male choice in these butterflies, the nonfunctional sexual correlation hypothesis remains a viable explanation for the female ornament.7 page(s
The Role of coloration in mate choice and sexual interactions in butterflies
Chapter Two. A major focus of behavioral ecology is to understand the evolutionary causes and consequences of sexual signaling. Great strides have been made, particularly in the realm of color-based signaling, using model organisms in target groups such as birds and fish. Such work has demonstrated how information regarding phenotypic and/or genetic quality may be encoded in various types of color ornaments, which thereby offers an explanation to their adaptive value in mate assessment. However, until recently, attempts to examine such hypotheses have rarely used butterflies as subjects. This is surprising on several fronts. First, butterflies display an exceptional diversity of coloration, which is generated by a large breadth of color-production mechanisms and which provided part of the impetus for Darwin's ideas about sexual selection. Second, butterflies are well suited to behavioral, physiological, morphological, and genetic investigations, and features of their life history make them a novel venue for testing ideas about the potential information value of color signals.In this chapter, we review how studies of butterflies have advanced the field of color signal evolution. Lepidopteran wing coloration has long (and sometimes famously) featured in studies of behavior, genetics, and evolution; our focus here is on efforts to understand the evolutionary ecology of highly exaggerated and male-limited wing markings. Behavioral experiments have revealed female mating preferences for male coloration that transcend simple species and/or mate recognition. These findings have, in turn, promoted butterflies as a system for testing and refining theories of mate-quality signaling, in cluding models based on the signaling of genetic quality. Coupled with this, physicists have seized upon butterflies as a vehicle for understanding natural photonic structures, thereby unearthing an impressive array of color mechanisms (such as three-dimensional crystalline structures) and fuelling the further refinement of signaling hypotheses. We review this progress, showcasing work in the two Coliadine genera Colias and Eurema and focusing on the relevance of this work to our understanding of signaling system evolution.38 page(s
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