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131.
132.
Mellinger DK Nieukirk SL Klinck K Klinck H Dziak RP Clapham PJ Brandsdóttir B 《Biology letters》2011,7(3):411-413
North Atlantic right whales (Eubalaena glacialis) were found in an important nineteenth century whaling area east of southern Greenland, from which they were once thought to have been extirpated. In 2007-2008, a 1-year passive acoustic survey was conducted at five sites in and near the 'Cape Farewell Ground', the former whaling ground. Over 2000 right whale calls were recorded at these sites, primarily during July-November. Most calls were northwest of the historic ground, suggesting a broader range in this region than previously known. Geographical and temporal separation of calls confirms use of this area by multiple animals. 相似文献
133.
Mythili MD Vyas R Patra SS Nair SC Akila G Sujatha R Gunasekaran S 《Journal of medical primatology》2005,34(1):35-40
The present study is aimed at determining some haematological and biochemical parameters in the wild Indian bonnet monkeys as also the microscopic and ultrastructural characteristics of their pancreatic islets. Adult wild Indian bonnet monkeys (Macaca radiata radiata) of both sexes weighing between 2.5 and 4 kg were used in these experiments. Their platelet, reticulocyte and total leukocyte counts and the blood concentrations of hemoglobin and plasma proteins and the serum concentrations of aspartate amino transferase, alanine amino transferase and calcium are similar to the values reported for M. mulatta. Plasma glucose is lower when compared with reported values of M. mulatta and M. fascicularis. Insulin levels are comparable with those of M. mulatta and M. nigra. Histology of islets is similar to that of humans. Ovoid cell collections of islet cells are scattered throughout the pancreas. Ultrastructure of A, B and D cells is similar to humans. These findings suggest that this relatively underutilized macaques may be a suitable model for biomedical research. 相似文献
134.
Mestres J 《Proteins》2005,58(3):596-609
The recent availability of crystal structures for several diverse cytochromes P450 (CYPs) offers the possibility to perform an up-to-date comparative analysis to identify the degree of structure conservation among this superfamily of enzymes specially relevant for their involvement in drug metabolism and toxicity. A set of 9 CYPs sharing between 10% and 27% sequence identity was selected, including 7 class I (CYP 101, 107, 108, 119, 121, 51, and 55) and two class II (CYP 102, and 2C5) structures. After obtaining a multiprotein structure superimposition, a structure-based sequence alignment was derived. Mapping the level of three-dimensional structural conservation onto the sequence alignment revealed that over 28% of the alignment positions have the Calpha carbons of their residues within a root-mean-square deviation (RMSD) of 2 A. This degree of structure conservation is found to be generally preserved, even when the structure undergoes dramatic conformational changes. Performing the analysis on 4 members of the CYP2 family (CYP 2B4, 2C5, 2C8, and 2C9), the percentage of alignment positions within 2 A RMSD amounted to 73%, increasing to over 85% when only structures in a closed conformation are considered. The present findings suggest that it should be plausible to derive models of overall good quality for the major CYP2 metabolizing forms (CYP 2A6, 2C19, 2D6, and 2E1), whereas high levels of uncertainty are still likely to be expected in models for the remaining 2 major P450 metabolizing forms (CYP 1A2 and 3A4), with the corresponding implications for their potential applicability in drug design activities. 相似文献
135.
Nicolas?PouletEmail author Céline?Arzel Samir?Messad Sovan?Lek Christine?Argillier 《Hydrobiologia》2005,543(1):79-90
Pikeperch (Sander lucioperca L.) is a broadly distributed fish species in Europe but little is known about its ecology in the southern part of its distribution area in warm climatic conditions. The aim of this study was to analyse pikeperch rate of movement and to assess whether it displayed a diel pattern related to temperature. Thus acoustic telemetry was used to track adult pikeperch in a drainage canal located in south of France. The survey was carried out in spring, during the spawning period. The results showed that females were more active than males. This is in accordance with previous data on the nest guardian behaviour of the males. For both genders, the activity rates increased during the study period as water temperature rose. Males and females displayed the same diel activity with a maximum at dusk, thereby confirming many indirect observations. Nevertheless, inter-individuals variations were observed. Thus, these results on diel activity are rather a general trend than a strict rule and suggest the involvement of other factors than light intensity in the control of diel activity. This diel rhythm is positively correlated to water temperature for females. Pikeperch activity may be the result of a trade-off between physiological requirements of temperature and light, satisfaction of energy needs and avoidance of predators. 相似文献
136.
Landscape ecology planning principles in Korean Feng-Shui, Bi-bo woodlands and ponds 总被引:1,自引:0,他引:1
The purpose of this study is to suggest practical planning principles, which are absent in landscape ecology planning, according to which the spatial completeness of the watershed is derived from native Korean Feng-Shui (). Landscape ecology planning principles are used widely in contemporary planning projects in terms of patch, corridor, matrix and network of landscape pattern. However, landscape indices for planning principles are complicated and constrained, and so are limited to applications for site and eco-village plannings. Native Korean Feng-Shui is different from Chinese Feng-Shui in that it is aimed at theoretical completeness in terms of aspect and topographical shape, based on the concept of ideal Myung-dang () to complete the space, according to local conditions in the physiognomy of the watershed. The complementary method is called Bi-bo () in native Korean Feng-Shui. These principles have been applied in traditional Korean villages, leading to consistent location choices and fractal patterns in land use. Furthermore, Bi-bo woodlands and ponds have been introduced to achieve spatial completeness in the landscape structure of the village. 相似文献
137.
Jessica L. Yorzinski Gail L. Patricelli 《Proceedings. Biological sciences / The Royal Society》2010,277(1683):923-932
Animals in many vertebrate species vocalize in response to predators, but it is often unclear whether these antipredator calls function to communicate with predators, conspecifics or both. We evaluated the function of antipredator calls in 10 species of passerines by measuring the acoustic directionality of these calls in response to experimental presentations of a model predator. Acoustic directionality quantifies the radiation pattern of vocalizations and may provide evidence about the receiver of these calls. We predicted that antipredator calls would have a lower directionality if they function to communicate with surrounding conspecifics, and a higher directionality and aimed at the receiver if they function to communicate with the predator. Our results support both of these functions. Overall, the birds produce antipredator calls that have a relatively low directionality, suggesting that the calls radiate in many directions to alert conspecifics. However, birds in some species increase the directionality of their calls when facing the predator. They can even direct their calls towards the predator when facing lateral to it—effectively vocalizing sideways towards the predator. These results suggest that antipredator calls in some species are used to communicate both to conspecifics and to predators, and that birds adjust the directionality of their calls with remarkable sophistication according to the context in which they are used. 相似文献
138.
Movement patterns and habitat utilization by black bream Acanthopagrus butcheri (Sparidae), an estuarine resident species, were investigated using acoustic telemetry in a small estuary on the east coast of Tasmania, Australia. Thirty‐four adult A. butcheri were tracked for periods of up to 187 days between August 2005 and January 2006. Although able to tolerate a wide range of salinities, the fish spent most of the time within the upper and middle regions of the estuary, where brackish conditions dominated. The species exhibited extensive movements linked to tidal cycles, with small‐scale upstream movements during incoming tides and downstream movements during out going tides. The extent of these movements was positively correlated with the tidal height difference between consecutive tidal peaks and troughs. Freshwater inflows and resultant changes in salinity also significantly influenced distribution and movement patterns. Fish moved downstream during the periods of heavy inflows, returning upstream as salinities increased to c. >10. During the peak of spawning period (November to December) fish moved into the upper region of the estuary, where they aggregated to spawn. Periodic increases in freshwater discharge, however, resulted in fish leaving the spawning grounds and moving downstream. Towards the end of the spawning season (January), the fish became more dispersed throughout the entire estuarine system. 相似文献
139.
The aim of this study was to assess the hydraulic vulnerability of Norway spruce (Picea abies) trunkwood by extraction of selected features of acoustic emissions (AEs) detected during dehydration of standard size samples. The hydraulic method was used as the reference method to assess the hydraulic vulnerability of trunkwood of different cambial ages. Vulnerability curves were constructed by plotting the percentage loss of conductivity vs an overpressure of compressed air. Differences in hydraulic vulnerability were very pronounced between juvenile and mature wood samples; therefore, useful AE features, such as peak amplitude, duration and relative energy, could be filtered out. The AE rates of signals clustered by amplitude and duration ranges and the AE energies differed greatly between juvenile and mature wood at identical relative water losses. Vulnerability curves could be constructed by relating the cumulated amount of relative AE energy to the relative loss of water and to xylem tension. AE testing in combination with feature extraction offers a readily automated and easy to use alternative to the hydraulic method. 相似文献
140.
Karen M. Stainbrook Karin E. Limburg Robert A. Daniels Robert E. Schmidt 《Hydrobiologia》2006,571(1):313-327
We examined long-term ecological change in two Hudson River tributaries, the Wappinger and Fishkill Creek watersheds in Dutchess
County, New York State. Fish data spanning 65 years (1936, 1988, 1992, and 2001) and shorter term macroinvertebrate data (1988,
2001) were used to assess the influence of land use practices. Between 1988 and 2001, macroinvertebrate index Biotic Assessment
Profile (BAP) improved by 113–165% in the Fishkill Creek watershed, and fish Index of Biotic Integrity (IBI) improved by 117–140%.
Fish IBI and fish species richness were significantly different (p < 0.01) between the watersheds, with Wappinger Creek in better condition. Long-term fish IBI scores showed degradation in both watersheds
since the 1930s. Changes in species composition suggest community homogenization on par with overall changes in the fish fauna
of New York. Most notable were increases in tolerant species and declines in intolerant or moderately tolerant species. Whereas
Fishkill Creek IBIs showed decline in 1988 relative to 1936, followed by improvement, Wappinger Creek declined monotonically
in environmental quality. Development has intensified in both watersheds, but Fishkill Creek is improving while Wappinger
Creek watershed is undergoing less mitigated degradation. We find that older, semi-quantitative data can be used to construct
environmental quality indicators, and can be of great use for measuring long-term change. 相似文献