Predictions of stream landscape theory were tested with common agency fishery data in watersheds heavily fragmented by dams and barriers; large stream fragments support higher species diversity, more abundant populations, and a greater range of fish sizes. Study watersheds discharge to the Hudson River in New York USA, drain rocky and high relief landscapes, and have numerous mill dams and stream barriers. Stream fragments with fish collections ranged from 0.3 km to 119 km in contiguous length. Larger stream fragments had more diverse fish communities but not higher fish densities nor a wider range of fish sizes. However, almost all large stream fragments were supporting reproduction and rearing of the dominant stream species (brown trout Salmo trutta, brook trout Salvelinus fontinalis) while small fragments had no evidence of providing this fish community support. Therefore, consistent with the fundamental basis of stream landscape theory, large stream networks provide support for more species and more secure populations. The study supports the concept that diverse fish communities and secure populations benefit from access to a wide range of stream habitats.
Leafrollers can experience high levels of indigenous parasitism in organically managed apple orchards and the augmentative release of specific parasitoid species to suppress these secondary pests may be advantageous in orchards converting to non-chemical pest management. Caged and uncaged releases of two ichneumonid [Apophua simplicipes (Cresson) and Glypta variegata Dasch] and two braconid (Macrocentrus linearis Nees and Apanteles polychrosidis Viereck) koinobiont endoparasitoids of the obliquebanded leafroller, Choristoneura rosaceana (Lepidoptera: Tortricidae) on host-infested potted apple trees were conducted to assess the parasitoids' abilities to find and successfully parasitize sentinel hosts under orchard conditions. Seasonal timing of the trials varied for each parasitoid species, based on their relative performance under simulated summer/fall conditions in laboratory trials. After the release of five or fifty parasitoid females, the mean percent parasitism of leafroller larvae collected from infested trees ranged from 0 to 75% depending on the parasitoid species involved. Although caged releases tended to increase the percentage of live parasitized hosts in release treatments, uncaged releases provided a more realistic assessment of the parasitoid's ability to seek and find hosts within an infested area over a longer period. Release of the large, solitary A. simplicipes, had the most significant impact on the host population density.
Sex and gender matter in all aspects of life. Humans exhibit sexual dimorphism in anatomy, physiology, but also pathology. Many of the differences are due to sex chromosomes and, thus, genetics, other due to endocrine factors such as sex hormones, some are of social origin. Over the past decades, huge number of scientific studies have revealed striking sex differences of the human brain with remarkable behavioral and cognitive consequences. Prenatal and postnatal testosterone influence brain structures and functions, respectively. Cognitive sex differences include especially certain spatial and language tasks, but they also affect many other aspects of the neurotypical brain. Sex differences of the brain are also relevant for the pathogenesis of neuropsychiatric disorders such as autism spectrum disorders, which are much more prevalent in the male population. Structural dimorphism in the human brain was welldescribed, but recent controversies now question its importance. On the other hand, solid evidence exists regarding gender differences in several brain functions. This review tries to summarize the current understanding of the complexity of the effects of testosterone on brain with special focus on their role in the known sex differences in healthy individuals and people in the autism spectrum.
Autism spectrum disorders (ASD) are neurodevelopmental conditions characterized by impairment in social communication and presence of stereotyped/restricted behaviors. Children with ASD very often demonstrate co-morbid psychiatric problems, problems known to be affected by testosterone in neurotypical populations. However, there are few reports investigating relationships between testosterone and psychiatric conditions in children with ASD. The aim of this study was to determine the relationship between plasmatic levels of testosterone and behavioral/emotional problems in pre-pubertal boys with ASD. The study sample consisted of 31 pre-pubertal boys (ages 3-10) with ASD. Parents completed the Nisonger Child Behavior Rating Form (NCBRF) to assess specific behavioral/emotional problems as observed in the previous 2 months. Plasmatic testosterone levels were determined in boys according to standardized procedures. It was found that there were positive correlations between testosterone levels and the conduct problems subscale (p=0.034, rs=0.382) of NCBRF and also between testosterone levels and the hyperactive subscale (p=0.025, rs=0.402) of NCBRF. Findings in this study are in line with research conducted in the neurotypical population. This is the first large study investigating testosterone and emotional/behavioral problems in ASD and warrants further research in this field in order to clarify the etiopathogenesis of psychiatric co-morbidities and improve their treatment., A. Pivovarciova, J. Durdiakova, S. Hnilicova, D. Filcikova, D. Ostatnikova., and Obsahuje bibliografii
The extent to which sex differences in cardiac function may be attributed to the direct myocardial influence of testosterone is unclear. In this study the effects of gonadal testosterone withdrawal (GDX) and replacement (GDX+T) in rats, on cardiomyocyte shortening and intracellular Ca2+ handling was investigated (0.5 Hz, 25 oC). At all extracellular [Ca2+] tested (0.5-2.0 mM), the Ca2+ transient amplitude was significantly reduced (by ~ 50 %) in myocytes of GDX rats two weeks post- gonadectomy. The time course of Ca2+ transient decay was significantly prolonged in GDX myocytes (tau, 455±80 ms) compared with intact (279±23 ms) and GDX+T (277±19 ms). Maximum shortening of GDX myocytes was markedly reduced (by more than 60 %) and relaxation significantly delayed (by more than 35 %) compared with intact and GDX+T groups. Thus testosterone replacement completely reversed the cardiomyocyte hypocontractility induced by gonadectomy. These results provide direct evidence for a role of testosterone in regulating functional Ca2+ handling and contractility in the heart., C. L. Curl ... [et al.]., and Obsahuje seznam literatury
The aim of this work was testing and subsequent calibration of RGB colorimeters. RGB colorimeters are cost-effective tools allowing to perform a number of colorimetric measurements. The aim of this work was to verify their accuracy and to develop methods for their calibration. We show how the calibration method proposed in this paper allows to work even with probes that provide inaccurate measurements due to faulty hardware. and Cílem této práce bylo testování a následná kalibrace RGB kolorimetrů. RGB kolorimetry představují cenově dostupné nástroje umožňující provádět celou řadu kolorimetrických měření. Cílem naší práce bylo ověření jejich přesnosti a vypracování metody jejich kalibrace. Ukazujeme, jak námi navržená metoda kalibrace umožňuje pracovat i se sondami, které již samy o sobě vlivem hardwarových chyb poskytují nepřesná data.
One of the biggest problem in the production of very precise aspherical optics is the mid-spatial frequency. These frequencies are created during grinding and lapping of optical surfaces on CNC machines. Using today’s conventional sub-aperture CNC polishing techniques, we are able to correct these defects only to a very limited extent. With a thorough analysis of these defects, a polishing tool can be developed to successfully suppress these defects. The article deals with the test of experimental instruments developed for the purpose of suppression of mid-spatial frequencies to very precise aspherical optics. These tests were performed on a CNC Optotech MCP 250 polishing machine using conventional polishing processes. and Jednou z největších překážek při výrobě velmi přesné asférické optiky jsou dnes tzv. střední prostorové frekvence. Tyto frekvence vznikají převážně při broušení a lapování optických ploch na CNC strojích. Pomocí dnešních konvenčních technik subaperturního CNC leštění jsme schopni tyto vady korigovat jen ve velmi omezené míře. Za pomoci důkladného rozboru vzniku těchto vad bude možno vyvinout lešticí nástroj, pomocí kterého by bylo možno tyto vady úspěšně potlačovat. Článek řeší tématiku testů experimentálních nástrojů vyvíjených za účelem potlačování středních prostorových frekvencí na velmi přesné asférické optice. Tyto testy byly prováděny na CNC lešticím stroji Optotech MCP 250 s použitím konvenčních lešticích procesů.
Technologie v Centru výzkumu Řež byly primárně postaveny za účelem vývoje a testování materiálů pro jaderné elektrárny současné i budoucí generace, nicméně jejich využití je mnohem širší. Jednou z možností je vytváření ekvivalentních podmínek, jaké panují ve vesmíru. Proto vznikl projekt zaměřený na testování komponentů pro vesmírný průmysl. Na konci bylo představení výsledků v podobě radiačního testování elektrických vlastností solárních článků od společností Spectrolab, Inc., a Azur Space Power GmbH. Tedy těch, které jsou používány pro vesmírné aplikace a v případě Azur Space i typově stejné, jaké byly umístěny na první slovenské družici skCUBE, která úspěšně krouží na orbitě Země od června 2017., Michaela Rabochová, Roman Mohyla, Martin Magyar., and Obsahuje bibliografické odkazy