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551.
552.
Changes in species composition and richness across the sub-alpine forest ecotone are well known phenomena. The total number of species at a regional scale drops substantially above the forest-line in the central Himalayas of Nepal. This study tests the effect of a forest border ecotone on a local scale using a grain size of 100 m2. We sampled a set of vertical transects across a sloping sub-alpine forest line where canopy and temperature covary, and a set of horizontal transects across a forest ecotone where there was no altitudinal difference to eliminate the influence of temperature. Detrended correspondence analysis revealed a continuous change in species composition across the forest border ecotone. Species turnover was, in general, low, and species richness did not vary very much between the forest and open landscapes. We attribute this to the grazing and browsing pressure in the area, which may have lowered the tree line. A reduced tree line compared to the climatic limit may facilitate enhanced species richness above the forest line. There was no significant difference in species richness between forest and open landscapes along horizontal transects where temperature variations were minimized. This study exemplifies the difficulties encountered on a local scale when one aims to test diversity hypotheses deduced from general models on forest-ecotone effect and mass effect. The low species turnover and minor differences in alpha diversity may be because the area is a cultural landscape and the homogenizing effect of domestic animals overrides some of the edge effects of the ecotone. 相似文献
553.
Shrestha Sony Md. Abdul Alim Sangwon Kim Minsoo Kwon Dongkyun Lee Yonggyun Kim 《Journal of Asia》2009,12(2):107-111
Two molecular identification techniques for differentiating six lepidopteran pests infesting apples in Korea are presented. These six species include two internal fruit feeders (Grapholita molesta and Carposina sasakii), two leaf rollers (Adoxophyes sp. and Archips breviplicanus) and two leaf miners (Phyllonorycter ringoniella and Lyonetia prunifoliella). All species occur until near harvest and reduce apple production. A 489 bp fragment of mitochondrial cytochrome oxidase subunit I (COI) was sequenced in these six species. The sequence was used to select species-specific restriction enzyme sites and to design diagnostic polymerase chain reaction (PCR) primers, resulting in the development of restriction fragment length polymorphism (RFLP)-PCR and diagnostic PCR. These methods were reliable and rapid in the identification of these six species. 相似文献
554.
555.
ABSTRACT The endoplasmic reticulum (ER) is the largest membrane-bound organelle in eukaryotic cells and plays critical roles in diverse processes in metabolism, signaling and intracellular organization. In response to stress stimuli such as nutrient deprivation, accumulation of misfolded proteins or exposure to chemicals, the ER increases in size through upregulated synthesis of its components to counteract the stress. To restore physiological size, the excess ER components are continuously dismantled and degraded by reticulophagy, a form of autophagy that targets, via adaptor molecules called reticulophagy receptors, specific ER portions to the lysosome for degradation. Previous studies have identified several ER resident proteins as reticulophagy receptors. In a recent study, we identified CALCOCO1 as a soluble reticulophagy receptor for the degradation of tubular ER in response to proteotoxic and starvation-induced stress. On the ER membrane, CALCOCO1 interacts with VAPA and VAPB via a FFAT-like motif and recruits autophagy machinery by binding directly to Atg8-family proteins via LIR and UDS interacting region (UIR) motifs acting co-dependently. Depletion of CALCOCO1 in cultured cells led to an impaired ER degradation during stress. 相似文献
556.
The MOPC 104E cell line has been adapted to grow in vitro using a combination of feeder layer and growth factor(s). The growth of this myeloma cell line is dependent on the presence of growth factor(s). Growth-promoting activity generated from T-cell-mitogen-stimulated, Corynebacterium parvum-stimulated spleen cell culture supernatant, and peritoneal adherent cell culture supernatants gives dose-dependent proliferation. Generation of growth factors in the serum-free bovine serum albumin-substituted media and a rapid assay system based on [3H]thymidine uptake for the quantitation of growth promoting activity are described. 相似文献
557.
C. Wemmer V. Krishnamurthy S. Shrestha L.‐A. Hayek Myo Thant K.A. Nanjappa 《Zoo biology》2006,25(3):187-200
A method of assessing body condition of Asian elephants (Elephas maximus) is presented. The method uses visual assessment to assign numerical scores to six different regions of the body, which are totaled to give a numerical index ranging from 0–11. The relationship between the index and morphometric variables is compared for a sample of 119 juvenile and young adult elephants from southern India, Nepal, and Myanmar. Mean ages of males and females were similar. Mean index of body condition (with standard error [SE]) was 7.3±0.2 points. No significant correlation was found between index of body condition and age over both sexes (r=0.01, n=50). Results were equivalent when sexes were treated separately (females: r=0.03, n=24; males: r=0.01, n=26). Sexes did not differ in height of the shoulder or body condition in our sample, but there was significant sexual dimorphism in breadth of the zygomatic arch and three measures of subcutaneous fat: girth of neck, thickness of cervical fold, and thickness of anal flap. These three measures were also significantly correlated with each other. Our assessment method should prove a practical tool for ecologic studies, but the relationship of the index to percentage of body fat should be determined using heavy water dilution methodology. Zoo Biol 25:187–200, 2006. © 2006 Wiley‐Liss, Inc. 相似文献
558.
Jane Teas Henry G. Taylor Thomas L. Richie Rakesh Das Shrestha George K. Turner Charles H. Southwick 《Primates; journal of primatology》1981,22(4):580-586
During five years of birth season fieldwork, we observed two births and three peri-birth instances of behavior of free-ranging
rhesus living in Kathmandu, Nepal. These constitute the first two recorded free-ranging rhesus births, and we compare them
to the behavior which has been observed in captivity and expected in the wild. The free-ranging parturition behavior was characterized
by a general lack of contact with other troop members and by overall inconspicuousness. In the first birth we observed, the
troop moved about 70 m up the hill, leaving the laboring female behind on an open hillside. Two males, a female and a juvenile
returned and rested about 20 m from the delivering female. During the second delivery, the female stayed with the troop and
seemed to participate normally in most troop interactions, although she avoided physical contact with other troop members.
We propose that this near-normal behavior may help to assure successful parturition by allowing the female the needed social
isolation and inconspicuousness without any loss of troop protection. It may also partly explain why births have not been
observed during previous studies. Observations of rhesus parturition behavior reported from studies of captive monkeys and
reports from other free-ranging primate studies are compared with our data. 相似文献
559.
560.
Rare fishes of Himalayan waters of Nepal 总被引:1,自引:0,他引:1
T. K. Shrestha 《Journal of fish biology》1990,37(SA):213-216