263 research outputs found
When do beetles and bugs fly? A unified scheme for describing seasonal flight behaviour of highly dispersing primary aquatic insects
Many authors investigated the dispersal flight of aquatic insects, but the exact length of the seasonal flying periods and its main characteristics have not been determined. A wide spectrum of species must be investigated before drawing general conclusions on seasonal changes about dispersal flight. Seasonal dispersal flight of aquatic beetles and bugs were studied during a 30-week long monitoring period. Insects were attracted to highly polarizing horizontal shiny black plastic sheets. 90 species/taxa and more than 45 000 individuals were captured during the sampling period. Aquatic insects were rising into the air during all periods of the year (from April till October). We hypothesized that species or group of species can be characterized by different seasonal rhythms of their dispersal flight. A unified scheme was established based on seasonal dispersal activity of 45 species to assess the dispersal behaviour. Detailed information about seasonal dispersal of 22 more species, and seasonal dispersal pattern were predicted in cases of further 23 species. In all, three seasonal patterns and twelve sub-patterns were identified based on specific characteristics of flight. The scheme is widely and generally applicable to characterize the seasonal dispersal flight of primarily aquatic insects. To demonstrate this, we performed the classification on previously reported data. Both previous and current results of the flight dispersal studies can be classified in the scheme, and the results are comparable by using this unified categorization
Technológiai Előretekintési Program
Az Országos Mûszaki Fejlesztési Bizottság döntése
alapján 1998-ban átfogó elemzés kezdôdött Technoló-
giai Elôretekintési Program (TEP) néven. A program
célja, hogy a piaci és technológiai lehetôségek feltá-
rásával hozzájáruljon a hosszú távú versenyképesség
növelĂ©sĂ©hez Ă©s ezen keresztĂĽl az Ă©letminĂ´sĂ©g javĂtásá-
hoz. A TEP a gazdasági, társadalmi folyamatok, a tudo-
mány és technika eredményeinek elemzésével megje-
löli azon kulcskérdéseket, döntési pontokat, amelyek
meghatározzák az egyes szakmai területek illetve az
ország jövĂ´jĂ©t a következĂ´ 15-25 Ă©vben. Az IrányĂtĂł
Testület és a munkacsoportok elemezték a jelenlegi
helyzetet,
eltérô
jövôképeket
vázoltak fel, és a legked-
vezĂ´bbnek ĂtĂ©lt – de a mai feltĂ©telek mellett, tudatos,
összehangolt erĂ´feszĂtĂ©sek nĂ©lkĂĽl nem feltĂ©tlenĂĽl a leg-
valĂłszĂnĂ»bb – jövĂ´kĂ©p megvalĂłsĂtását cĂ©lzĂł
ajánlásokat
fogalmaztak meg. A legkedvezôbb jövôképbôl leve-
zetett ajánlások tehát mindazoknak szólnak, akik köz-
vetlenül vagy közvetve hatással lehetnek az egyes
szakterületek vagy a magyar társadalom és gazdaság
egészének jövôjére
Correction to the Clausius-Mosotti equation: the dielectric constant of nonpolar fluids from Monte Carlo simulations
We examine the dielectric constant of nonpolar fluids by direct Monte Carlo simulations on the basis of the polarizable hard sphere (PHS) model, where the spheres carry molecular polarizabilities. Point dipoles are induced in the spheres partly by an external electric field and partly by other molecules. It has been known that the Clausius–Mosotti equation needs a correction due to mutual polarization between molecules. We reproduce the qualitative behavior found in experiments: the correction increases with increasing density, reaches a maximum, and decreases at high densities. We show that the classic theory of Kirkwood and Yvon is quantitatively correct for the PHS model.
© 2009 American Institute of Physic
A Zala és befolyói makroszkopikus gerinctelen faunája | On the macroinvertebrate fauna of river Zala and its inflows
A Zala és befolyói makroszkopikus gerinctelen faunája kevéssé is-mert, habár számos faunisztikai jellegű gyűjtést végeztek ezen a területen. Dolgozatunkban átfogó irodalmi áttekintést adunk a Zala és befolyói makrogerinctelen faunájáról, illetve saját, 2007-ben végzett faunisztikai felmérésünk eredményeit mutatjuk be.
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Although many faunistical investigations were carried out in this area, the aquatic macroinvertebrate fauna of River Zala and its inflows is poorly known. In this paper a compilation is given on the macroinvertebrate fauna of River Zala and its inflows, and the results of own faunistical investigations carried out in 2007 are presented
What is progressive business?
This introductory chapter signposts the rationale, framework and case study contents of the book. Firstly, we offer an overview of the need for new more progressive business models than the mainstream which exists at present, identifying the current challenges facing business in Europe and beyond in its international ramifications. To remedy these challenges, we present our alternative vision of progressive business functioning, whose basic criteria comprise ecological sustainability, respect for future generations, and pro-socialness. Then, synopses of our case examples follow
Cellular Factor XIII, a Transglutaminase in Human Corneal Keratocytes
Cellular factor XIII (cFXIII, FXIII-A2), a transglutaminase, has been demonstrated in a few cell types. Its main function is to cross-link proteins by isopeptide bonds. Here, we investigated the presence of cFXIII in cells of human cornea. Tissue sections of the cornea were immunostained for FXIII-A in combination with staining for CD34 antigen or isopeptide cross-links. Isolated corneal keratocytes were also evaluated by immunofluorescent microscopy and flow cytometry. FXIII-A in the corneal stroma was quantified by Western blotting. FXIII-A mRNA was detected by RT-qPCR. The cornea of FXIII-A-deficient patients was evaluated by cornea topography. FXIII-A was detected in 68 ± 13% of CD34+ keratocytes. Their distribution in the corneal stroma was unequal; they were most abundant in the subepithelial tertile. cFXIII was of cytoplasmic localization. In the stroma, 3.64 ng cFXIII/mg protein was measured. The synthesis of cFXIII by keratocytes was confirmed by RT-qPCR. Isopeptide cross-links were detected above, but not within the corneal stroma. Slight abnormality of the cornea was detected in six out of nine FXIII-A-deficient patients. The presence of cFXIII in human keratocytes was established for the first time. cFXIII might be involved in maintaining the stability of the cornea and in the corneal wound healing process
Influence of solvent granularity on the effective interaction between charged colloidal suspensions
We study the effect of solvent granularity on the effective force between two
charged colloidal particles by computer simulations of the primitive model of
strongly asymmetric electrolytes with an explicitly added hard sphere solvent.
Apart from molecular oscillating forces for nearly touching colloids which
arise from solvent and counterion layering, the counterions are attracted
towards the colloidal surfaces by solvent depletion providing a simple
statistical description of hydration. This, in turn, has an important influence
on the effective forces for larger distances which are considerably reduced as
compared to the prediction based on the primitive model. When these forces are
repulsive, the long-distance behaviour can be described by an effective Yukawa
pair potential with a solvent-renormalized charge. As a function of colloidal
volume fraction and added salt concentration, this solvent-renormalized charge
behaves qualitatively similar to that obtained via the Poisson-Boltzmann cell
model but there are quantitative differences. For divalent counterions and
nano-sized colloids, on the other hand, the hydration may lead to overscreened
colloids with mutual attraction while the primitive model yields repulsive
forces. All these new effects can be accounted for through a solvent-averaged
primitive model (SPM) which is obtained from the full model by integrating out
the solvent degrees of freedom. The SPM was used to access larger colloidal
particles without simulating the solvent explicitly.Comment: 14 pages, 16 craphic
Rab2 promotes autophagic and endocytic lysosomal degradation
Rab7 promotes fusion of autophagosomes and late endosomes with lysosomes in yeast and metazoan cells, acting together with its effector, the tethering complex HOPS. Here we show that another small GTPase, Rab2, is also required for autophagosome and endosome maturation and proper lysosome function in Drosophila melanogaster. We demonstrate that Rab2 binds to HOPS, and that its active, GTP-locked form associates with autolysosomes. Importantly, expression of active Rab2 promotes autolysosomal fusions unlike that of GTP-locked Rab7, suggesting that its amount is normally rate limiting. We also demonstrate that RAB2A is required for autophagosome clearance in human breast cancer cells. In conclusion, we identify Rab2 as a key factor for autophagic and endocytic cargo delivery to and degradation in lysosomes
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