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1.
A preliminary investigation of home range use in the Gir Forest langur   总被引:1,自引:0,他引:1  
Two troops of grey langur monkeys (Presbytis entellus entellus) were observed in the Gir Forest, western India for approximately 220 hours in two of three seasons at very high crude densities ranging from 115–128 langurs per km2. Daily activity patterns and home range use are described and a scan-sampling technique of activity distribution employed. Food and predator avoidance are estimated to be major determinants of population density and home range size, structure, and composition.  相似文献   

2.
Individual variation in body size, home range size, and reproductive success among Neolamprologus mondabu (Cichlidae) females were investigated with reference to substrate types in the littoral zone of northern Lake Tanganyika. Larger females occupied sandy substrates and smaller ones stony substrates. Female reproductive success, estimated as the number of offspring successfully released per month, was higher on sandy substrates than on stony substrates. This may be attributable to higher spawning intensity and better protection of broods against predators in open, sandy habitats.  相似文献   

3.
R Bergeron  A Laberge  L Vézina  M Aubin 《CMAJ》1999,161(4):369-373
BACKGROUND: Recent changes in the North American health care system and certain demographic factors have led to increases in home care services. Little information is available to identify the strategies that could facilitate this transformation in medical practice and ensure that such changes respond adequately to patients'' needs. As a first step, the authors attempted to identify the major factors influencing physicians'' home care practices in the Quebec City area. METHODS: A self-administered questionnaire was sent by mail to all 696 general practitioners working in the Quebec City area. The questionnaire was intended to gather information on physicians'' personal and professional characteristics, as well as their home care practice (practice volume, characteristics of both clients and home visits, and methods of patient assessment and follow-up). RESULTS: A total of 487 physicians (70.0%) responded to the questionnaire, 283 (58.1%) of whom reported making home visits. Of these, 119 (42.0%) made fewer than 5 home visits per week, and 88 (31.1%) dedicated 3 hours or less each week to this activity. Physicians in private practice made more home visits than their counterparts in family medicine units and CLSCs (centres locaux des services communautaires [community centres for social and health services]) (mean 11.5 v. 5.8 visits per week), although the 2 groups reported spending about the same amount of time on this type of work (mean 5.6 v. 5.0 hours per week). The proportion of visits to patients in residential facilities or other private residences was greater for private practitioners than for physicians from family medicine units and CLSCs (29.7% v. 18.9% of visits), as were the proportions of visits made at the patient''s request (28.0% v. 14.2% of visits) and resulting from an acute condition (21.4% v. 16.0% of visits). The proportion of physicians making home visits at the request of a CLSC was greater for those in family medicine units and CLSCs than for those in private practice (44.0% v. 11.3% of physicians), as was the proportion of physicians making home visits at the request of a colleague (18.0% v. 4.5%) or at the request of hospitals (30.0% v. 6.8%). Physicians in family medicine units and CLSCs did more follow-ups at a frequency of less than once per month than private practitioners (50.9% v. 37.1% of patients), and they treated a greater proportion of patients with cognitive disorders (17.2% v. 12.6% of patients) and palliative care needs (13.7% v. 8.6% of patients). Private practitioners made less use of CLSC resources to assess home patients or follow them. Male private practitioners made more home visits than their female counterparts (mean 12.8 v. 8.3 per week), although they spent an almost equal amount of time on this activity (mean 5.7 v. 5.2 hours per week). INTERPRETATION: These results suggest that practice patterns for home care vary according to the physician''s practice setting and sex. Because of foreseeable increases in the numbers of patients needing home care, further research is required to evaluate how physicians'' practices can be adapted to patients'' needs in this area.  相似文献   

4.
The direct energy demand of Internet data flows can be assessed using a variety of methodological approaches (top‐down, bottom‐up, or hybrid/model based) and different definitions of system boundaries. Because of this diversity, results reported in the literature differ by up to two orders of magnitude and are difficult to compare. We present a first assessment that uses a pure bottom‐up approach and a system boundary that includes only transmission equipment. The assessment is based on the case study of a 40 megabit per second videoconferencing transmission between Switzerland and Japan, yielding a consumption of 0.2 kilowatt‐hours per transmitted gigabyte for 2009, a result that supports the lowest of the existing estimates. We discuss the practical implications of our findings.  相似文献   

5.
6.
Reproductive seasonality was examined in an equatorial population of free-living spotted hyaenas (Crocuta crocuta) in Kenya. The study population was observed continuously for 10 years, during which time the dates of all births, conceptions, weanings, and cub deaths were recorded. Local prey abundance was estimated two to four times per month, and rainfall was recorded daily throughout the study period. Births occurred during every month of the year, but a distinct trough in births occurred from February to May. This trough occurred approximately one gestation period after the phase of the annual cycle during which prey animals were least abundant in the home range of the hyaenas, and conceptions occurred most frequently when food abundance was greatest. Neither rainfall nor cub mortality were correlated with births or conceptions. Thus, although spotted hyaenas are capable of breeding throughout the year, they exhibit a moderate degree of seasonality that most likely reflects responses to seasonal variation in energy availability.  相似文献   

7.
The authors, expecting confirmation of arrhythmogenic effects of work at the Intensive Cardiological Care Unit (ICCU), recorded a 24-hour ECG in the employed staff. Together 20 healthy individuals (mean age 31.6 years) were tested. ECG was recorded twice at the unit, and repeated at home. Ventricular arrhythmia was noted in 60% of tested individuals at home (mean number of excitations 6 per 24 hours). It was 2.5 times more frequent at ICCU (mean number of excitations 15 per 24 hours) involving 75% of tested individuals. Atrial arrhythmia was noted also in 60% of the tested individuals at home (mean number 16 per 24 hours) whereas it was noted in 85% of the tested individuals at ICCU, i.e. 2.5 times more frequently than at home (mean value 40/24 hours). Both atrial and ventricular arrhythmias are significantly more frequent during night rest at ICCU than that at home. Results suggest that the employment at ICCU is arrhythmogenic.  相似文献   

8.
In order to understand the electricity use of Internet services, it is important to have accurate estimates for the average electricity intensity of transmitting data through the Internet (measured as kilowatt‐hours per gigabyte [kWh/GB]). This study identifies representative estimates for the average electricity intensity of fixed‐line Internet transmission networks over time and suggests criteria for making accurate estimates in the future. Differences in system boundary, assumptions used, and year to which the data apply significantly affect such estimates. Surprisingly, methodology used is not a major source of error, as has been suggested in the past. This article derives criteria to identify accurate estimates over time and provides a new estimate of 0.06 kWh/GB for 2015. By retroactively applying our criteria to existing studies, we were able to determine that the electricity intensity of data transmission (core and fixed‐line access networks) has decreased by half approximately every 2 years since 2000 (for developed countries), a rate of change comparable to that found in the efficiency of computing more generally.  相似文献   

9.
Nitrate reductase activity in leaf material ofLolium perenne L. cv. S24 was estimated using anin vivo assay method such that activity could be estimated at intervals of 5 minutes for up to two hours. The pattern of nitrate reductase activity, as estimated by nitrite accumulation, showed pronounced oscillatory behaviour with frequency of approximately 4 cycles per hour; at certain seasons however oscillatory activity was not shown. The phase of the oscillations observed in different experiments was not co-incident with respect to time of day.  相似文献   

10.
Estimates of predation rates by large predators can provide valuable information on their potential impact on their ungulate prey populations. This is especially the case for pumas Puma concolor and its main prey, mule deer Odocoileus hemionus . However, only limited information on predation rates of pumas exist where mule deer are the only ungulate prey available. I used VHF telemetry data collected over 24-h monitoring sessions and once daily over consecutive days to derive two independent estimates of puma predation rates on mule deer where they were the only large prey available. For the 24-h data, I had 48 time blocks on female pumas with kittens, 43 blocks on females without kittens and 30 blocks on males. For the daily consecutive data, the average number of consecutive days followed was 51.5±4.2 days. There were data on five female pumas with kittens, five pregnant females and nine females without kittens. Predation rates over an average month of 30 days from the 24-h monitoring sessions were 2.0 mule deer per puma month for males (15.1 days per kill), 2.1 mule deer per puma month (14.3 days per kill) for females without kittens and 2.5 mule deer per puma month (12.0 days per kill) for pregnant females and females with kittens. For the consecutive daily data, females without kittens had an estimated predation rate of 2.1±0.14 mule deer per puma month (14.9±0.90 days per kill). Pregnant and females with kittens had predation rates of 2.7±0.18 and 2.6±0.21 mule deer per puma month, respectively (11.4±0.72 and 12.0±1.1 days per kill, respectively). Predation rates estimated in this study compared with those estimated by energetic demand for pumas in the study area but were lower than other field derived estimates. These data help increase our understanding of predation impacts of large predators on their prey.  相似文献   

11.
Vasotoxic effect of prolonged lead exposures and the efficiency of vasoprotective effect of S. coronata extract per os addition is estimated in rats aorta It is established that lead in aorta causes a significant increase in reactive oxygen species (ROS) and reactive nitrogen species (RNS) generation by increasing the activity of inducible isoform of NO-synthase (iNOS). The use of S. coronata extracts promotes ROS and RNS production decreasing by normalyzing the iNOS activity in exposures to lead acetate rat aortas.  相似文献   

12.
Despite the considerable attention devoted to the biology of social species of African mole-rats (Bathyergidae, Rodentia), knowledge is lacking about their behaviour under natural conditions. We studied activity of the largest social bathyergid, the giant mole-rat Fukomys mechowii, in its natural habitat in Zambia using radio-telemetry. We radio-tracked six individuals during three continuous 72-h sessions. Five of these individuals, including a breeding male, belonged to a single family group; the remaining female was probably a solitary disperser. The non-breeders of the family were active (i.e. outside the nest) 5.8 hours per 24h-day with the activity split into 6.5 short bouts. The activity was more concentrated in the night hours, when the animals also travelled longer distances from the nest. The breeding male spent only 3.2 hours per day outside the nest, utilizing less than 20% of the whole family home range. The dispersing female displayed a much different activity pattern than the family members. Her 8.0 hours of outside-nest activity per day were split into 4.6 bouts which were twice as long as in the family non-breeders. Her activity peak in the late afternoon coincided with the temperature maximum in the depth of 10 cm (roughly the depth of the foraging tunnels). Our results suggest that the breeding individuals (at least males) contribute very little to the work of the family group. Nevertheless, the amount of an individual''s activity and its daily pattern are probably flexible in this species and can be modified in response to actual environmental and social conditions.  相似文献   

13.
The chief purpose of this activity is to strengthen students' understanding of concepts of floatation such as surface area and pressure (weight per unit area) via snowshoes. Students brainstorm, make predictions, perform calculations, and practice communication skills through interviewing elders and experts. This activity lets students see the marvelous relationship between the structural features of animals and their environment. They also get a better understanding of how humans have become better adapted to their environment by copying animals like the snowshoe hare. Students build their own snowshoes, and teachers have the opportunity to introduce American-Indian culture or integrate other social studies themes.  相似文献   

14.
Isolated soybean (Glycine max L. var Hood) embryonic axes have a spontaneous chemiluminescence (about 150 counts per minute per embryo) that increases showing two phases, upon water imbibition. The first photoemission burst was measured between 0 and 7 hours of imbibition with a maximum of about 350 counts per minute per embryo after 2 hours. The second photoemission phase, between 7 and 30 hours, increased from about 220 to 520 counts per minute per embryo. Both chemiluminescence phases were inhibited by infused butylated hydroxyanisole while only the second phase was inhibited by infused salicylhydroxamic acid. On the basis of the sensitivity of the lipoxygenase reaction to both inhibitors (about 90%), the first burst is tentatively assigned to oxy-radicals mobilized upon water uptake by the embryonic axes, and the second phase is tentatively identified as due to lipoxygenase activity. The in vivo lipoxygenase activity of the embryonic axes was estimated by both the fraction of total oxygen uptake that was inhibited by butylated hydroxyanisole and by the fraction of photoemission that was inhibited by butylated hydroxyanisole and by salicylhydroxamic acid. Both approaches indicated marked increases (5-fold and 12-fold, respectively) of lipoxygenase activity between 2 and 30 hours of imbibition. The measured chemiluminescence per O2 uptake ratio (the experimental quantum yield) for the lipoxygenase reaction (3.3 × 10−14 counts per O2 molecule) was used to estimate the O2 uptake due to lipoxygenase activity from the photoemission of the embryonic axes after 30 hours of imbibition. The value (0.54 microliters per minute per axis) was close to the butylated hydroxyanisole-sensitive O2 uptake (1.2 microliters O2 per minute per axis) of the same embryonic axes. Chemiluminescence may afford a noninvasive assay for lipoxygenase activity in intact plant tissues.  相似文献   

15.
Rafael Márquez 《Ecography》1992,15(3):279-288
The reproductive phenology of two Iberian populations of midwife toads Alytes obstetricans and A cistemasii were studied in 1988 and 1989 in two different habitats where chmatological conditions restricted reproductive activity to a few months per year All the observed mating activity of A cisternasii occurred in less than a week while A obstetricans ma tings were observed for over a month A cisternasii matmg activity was explosive and correlated with rainfall No clear trends were observed m the timing of egg mass releases with male size, egg mass size, and proportion of egg mass hatched In both populations males did not complete more than one cycle of egg mass tending per season The duration of terrestnal egg development was estimated to be of 32 d for A obstetricans Alytes cistemasii showed greater flexibility on the duration of egg development, egg masses being released 23 d after the matings m 1988 and 30 d after in 1989 This flexibility is an example of the adaptive significance of terrestrial paternal care when water availabihty is unpredictable  相似文献   

16.
Growth curves consist, in all cases, of two major segments. The first major segment is, in the case of higher animals and plants, made up in turn of several (probably five) shorter segments during each of which growth takes place at a constant percentage rate. The transitions between the successive stages are abrupt, the abruptness being of the order of metamorphosis in cold blooded animals. It has been made clear in the first paper of this series that the time rate of growth following the major inflection declines at a constant percentage rate. The junction between the two major segments occurs at puberty in animals and flowering in plants. The two major segments are not symmetrical about the major inflection. The slope of the segment following the inflection is always less than the slope of the segment preceding the inflection. The major inflection does not occur in the center of the growth curve. The instantaneous rate of growth at the beginning of growth is of the order of 100–200 per cent per day (i.e. the body weight is doubled in from 7 to 17 hours). It may be mentioned that 2 months after conception the rate of growth in man is only 8 per cent per day. This is contrary to all the published statements. Thus, Minot concluded that growth begins at 1000 per cent per day; Jackson concluded that in man, growth during the 1st month takes place at 57.5 million per cent per month; during the 2nd month 990 per cent per month; during the 3rd month 390 per cent per month (8 per cent per day is only 240 per cent per month). The reason for the discrepancy between the values derived, by the method adopted by the writer, and the values given in the literature is explained by Fig. 1.  相似文献   

17.
Bufler G 《Plant physiology》1986,80(2):539-543
Internal ethylene concentration, ability to convert 1-amino-cyclopropane-1-carboxylic acid (ACC) to ethylene (ethylene-forming enzyme [EFE] activity) and ACC content in the peel of apples (Malus domestica Borkh., cv Golden Delicious) increased only slightly during fruit maturation on the tree. Treatment of immature apples with 100 microliters ethylene per liter for 24 hours increased EFE activity in the peel tissue, but did not induce an increase in ethylene production. This ability of apple peel tissue to respond to ethylene with elevated EFE activity increased exponentially during maturation on the tree. After harvest of mature preclimacteric apples previously treated with aminoethoxyvinyl-glycine, 0.05 microliter per liter ethylene did not immediately cause a rapid increase of development in EFE activity in peel tissue. However, 0.5 microliter per liter ethylene and higher concentrations did. The ethylene concentration for half-maximal promotion of EFE development was estimated to be approximately 0.9 microliter per liter. CO2 partially inhibited the rapid increase of ethylene-promoted development of EFE activity. It is suggested that ethylene-promoted CO2 production is involved in the regulation of autocatalytic ethylene production in apples.  相似文献   

18.
Until recently, studies on polar bear (Ursus maritimus) movements and space use have used data collected by satellite telemetry collars that provided positions infrequently (typically weekly) and with low precision (by Doppler Shift method). A new generation of transmitters incorporated into collars use the Global Positioning System (GPS) to provide highly accurate positions, and have the ability to provide many positions per day. We used data from two GPS collars fitted to female polar bears, that attempted to collect six positions per day (4-h apart) for 546 days (from April 2000 to September 2001) and 413 days (from April 2000 to May 2001) to estimate how estimated speed of movement and home range size increase with increasing number of data points. Using all the positions, we estimated that the bears moved a minimum of 14.3 and 15.8 km per day on average. The fractal dimension (D) of the movement pathways for the two bears were D = 1.28 and 1.31, respectively, indicating low tortousity of the movements. Their minimum estimated annual home range areas were 20,794 and 112,183 km2. Simulations showed that a commonly used sampling regime of one location every 6th day would have significantly underestimated the movement rates and the home range sizes compared to our estimates. We also used the high accuracy of GPS positions to look at distances moved within 4-h periods. Maximum movement rate during a 4-h period for the two bears was 4.21 and 4.58 km/h, respectively. Variation in median values by month was significant (0.01 km/h in November for N23476 to 1.48 km/h in December for N7955). Diurnal variation was observed to differ between defined periods.  相似文献   

19.
This paper estimated the significance of ammonia excretion by Donax serra Röding in the regeneration of nitrogen for the surf-zone adjacent to a high energy beach. The migrations of D. serra over a tidal cycle were quantified in order to calculate inundation periods for each size class on an exposed beach. The rôle of this animal in surf-zone nitrogen regeneration was then estimated by measuring ammonia excretion rates of individual animals and then calculating NH4-N excretion for the whole population along the shoreline investigated. This gave an estimate of ≈ 300 g NH4-N per m of shoreline per yr using a biomass of 7000 g per m. This quantity is probably sufficient to regenerate the total nitrogen pool of the surf-zone every month.  相似文献   

20.
To analyse the population structure and reproductive biology of the Iberian hareLepus granatensis Rosenhauer, 1856, 498 hares (264 males and 234 females) were collected in monthly samples from October 1998 to September 1999. Females reached larger sizes than males, with approximately 400 g difference in body mass on reaching sexual maturity. The total sex ratio was 1∶1, with a bias in favour of males in winter. Sexually active males and females appeared in every month but August, when no sexually active female was found. Births occurred in every month and were more frequent between March and July. Seasonal variation in kidney fat index (KFI) followed a similar pattern in males and females, with an increase in mid-autumn and a decline at the end of winter. Reproductive activity appeared in every month, with a maximum from February to June. Reproductively hyperactive females (simultaneously pregnant and nursing) appeared in every month except in January, with a first peak in March and a second lower peak in May–June. Litter size fluctuated between 1 and 7 leverets. The most frequent gestations involved 1 or 2 foetuses. The mean annual litter size was 2.08 and the average number of litters per productive female per year was estimated to be 3.48. The maximum productivity was recorded between March and May. The total annual production of young per adult female was estimated to be 7.21. The minimum annual survival rate of young was 27.91%. On the basis of these results we propose to maintain the limit of the hunting period between October and December. We discuss the relationship between the low young/adult ratio obtained and the hunting method used.  相似文献   

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