Tick burden on European roe deer (<Emphasis Type="Italic">Capreolus capreolus</Emphasis>)

In our study we assessed the tick burden on roe deer (Capreolus capreolus L.) in relation to age, physical condition, sex, deer density and season. The main objective was to find predictive parameters for tick burden. In September 2007, May, July, and September 2008, and in May and July 2009 we collected ticks on 142 culled roe deer from nine forest departments in Southern Hesse, Germany. To correlate tick burden and deer density we estimated deer density using line transect sampling that accounts for different detectability in March 2008 and 2009, respectively. We collected more than 8,600 ticks from roe deer heads and necks, 92.6% of which were Ixodes spp., 7.4% Dermacentor spp. Among Ixodes, 3.3% were larvae, 50.5% nymphs, 34.8% females and 11.4% males, with significant seasonal deviation. Total tick infestation was high, with considerable individual variation (from 0 to 270 ticks/deer). Adult tick burden was positively correlated with roe deer body indices (body mass, age, hind foot length). Significantly more nymphs were found on deer from forest departments with high roe deer density indices, indicating a positive correlation with deer abundance. Overall, tick burden was highly variable. Seasonality and large scale spatial characteristics appeared to be the most important factors affecting tick burden on roe deer.     

Glycosylated hemoglobin as a stable alternative to serum glucose in white-tailed deer

We compared serum glucose concentration and percent glycosylated hemoglobin (GH) in captive and wild white-tailed deer (Odocoileus virginianus) to determine stability of glucose relative to GH. Temporal changes in levels of serum glucose and GH were ascertained from serial blood samples collected from three captive deer over a 2-week period. State of glycemia also was determined for 17 wild deer that were collected from three populations in southeastern Oklahoma and southwestern Arkansas (USA). Concentration of serum glucose of captive deer decreased (P = 0.04) from 190.4 to 155.8 mg/dl over the 2 weeks; percent GH did not differ temporally (P = 0.30). Percent GH of wild deer did not differ (P = 0.23) when deer were separated into 2 groups (high and low state of glycemia) based on the median serum glucose concentration. We found a significant difference (P = 0.04) in percent GH among wild deer populations; serum glucose concentration did not differ (P = 0.72) among populations. Our results indicate that percent GH is more stable than serum glucose concentration and may be useful in population comparisons of nutritional condition.     

Functionally distinct sodium channels in ventricular epicardial and endocardial cells contribute to a greater sensitivity of the epicardium to electrical depression

A greater depression of the action potential (AP) of the ventricular epicardium (Epi) versus endocardium (Endo) is readily observed in experimental models of acute ischemia and Brugada syndrome. Endo and Epi differences in transient outward K(+) current and/or ATP-sensitive K(+) channel current are believed to contribute to the differential response. The present study tested the hypothesis that the greater sensitivity of Epi is due in part to its functionally distinct early fast Na(+) current (I(Na)). APs were recorded from isolated Epi and Endo tissue slices and coronary-perfused wedge preparations before and after exposures to elevated extracellular K(+) concentration ([K(+)](o); 6-12 mM). I(Na) was recorded from Epi and Endo myocytes using whole cell patch-clamp techniques. In tissue slices, increasing [K(+)](o) to 12 mM reduced V(max) to 51.1 +/- 5.3% and 26.8 +/- 9.6% of control in Endo (n = 9) and Epi (n = 14), respectively (P < 0.05). In wedge preparations (n = 12), the increase in [K(+)](o) caused selective depression of Epi APs and transmural conduction slowing and block. I(Na) density was not significantly different between Epi (n = 14) and Endo (n = 15) cells, but Epi cells displayed a more negative half-inactivation voltage [-83.6 +/- 0.1 and -75.5 +/- 0.3 mV for Epi (n = 16) and Endo (n = 16), respectively, P < 0.05]. Our data suggest that reduced I(Na) availability in ventricular Epi may contribute to its greater sensitivity to electrical depression and thus may contribute to the R-ST segment changes observed under a variety of clinical conditions including acute myocardial ischemia, severe hyperkalemia, and Brugada syndrome.     

Infectious Disease and Grouping Patterns in Mule Deer

Infectious disease dynamics are determined, to a great extent, by the social structure of the host. We evaluated sociality, or the tendency to form groups, in Rocky Mountain mule deer (Odocoileus hemionus hemionus) from a chronic wasting disease (CWD) endemic area in Saskatchewan, Canada, to better understand factors that may affect disease transmission. Using group size data collected on 365 radio-collared mule deer (2008–2013), we built a generalized linear mixed model (GLMM) to evaluate whether factors such as CWD status, season, habitat and time of day, predicted group occurrence. Then, we built another GLMM to determine factors associated with group size. Finally, we used 3 measures of group size (typical, mean and median group sizes) to quantify levels of sociality. We found that mule deer showing clinical signs of CWD were less likely to be reported in groups than clinically healthy deer after accounting for time of day, habitat, and month of observation. Mule deer groups were much more likely to occur in February and March than in July. Mixed-sex groups in early gestation were larger than any other group type in any season. Groups were largest and most likely to occur at dawn and dusk, and in open habitats, such as cropland. We discuss the implication of these results with respect to sociobiology and CWD transmission dynamics.     

Costs of parturition and rearing in female sika deer (Cervus nippon)

The costs of parturition and lactation of female sika deer on Kinkazan Island (9.6 km(2) in size), northern Japan, which live at a high density (about 50 deer/km(2)), were evaluated by comparison of body weights of 481 females measured during a 15 year study (1993-2008). Weight data were chosen from only females that did not give birth in the preceding year. The mean body weight of females that did not give birth ("yelds") was significantly lower (P < 0.001) than that of females who gave birth ("milks"); yelds' body weight was 93.1% and 83.5% that of milks in the preceding and parturition years, respectively. The yelds increased in body weight by the following March by 8.2% (P < 0.001), whereas milks did not. Among the milks, those whose fawns survived until the following May ("rearing milks") lost body weight by 14.9% (P < 0.001). Milks who lost fawns within a week after birth ("early fawn-less milks") did not lose body weight (P = 0.583), while those whose fawns died after the first autumn but died before May ("late fawn-less milks") lost body weight by 19.9% (P < 0.001). These results indicate that sika deer females do not enter estrus unless they are heavy enough, and that both parturition and rearing are costly for sika deer mothers living in high-density conditions.     

Activity patterns and resource use by sheep and red deer grazing across a grass/heather boundary

Diet selection and activities of sheep and red deer grazing alone and together across a grass (primarily Lolium perenne/Agrostis capillaris ) and heather ( Calluna vulgaris ) boundary, between July and October, are described.
Throughout the experiment, both animal species had a much higher proportion of grass than heather in their diet. Time spent grazing on each type of vegetation was similarly greater on grass, and the bite rates of the animals were also more rapid on the grass than on the heather.
Red deer spent more time grazing per 24 hours than did sheep, with sheep grazing less during darkness hours than red deer. Total grazing time of both species did not decrease with decreasing daylength from July to October.
There were no consistent differences in the diurnal patterns of activity of sheep and red deer, with both species showing 2-3 large grazing peaks per day.
There were no consistent effects of mixing sheep and deer on their grazing behaviour and diet composition.     

Sodium-potassium synergism in Theobroma cacao: stimulation of photosynthesis, water-use efficiency and mineral nutrition

In ecological setting, sodium (Na(+) ) can be beneficial or toxic, depending on plant species and the Na(+) level in the soil. While its effects are more frequently studied at high saline levels, Na(+) has also been shown to be of potential benefit to some species at lower levels of supply, especially in C4 species. Here, clonal plants of the major tropical C3 crop Theobroma cacao (cacao) were grown in soil where potassium (K(+) ) was partially replaced (at six levels, up to 50% replacement) by Na(+) , at two concentrations (2.5 and 4.0 mmol(c) dm(-3) ). At both concentrations, net photosynthesis per unit leaf area (A) increased more than twofold with increasing substitution of K(+) by Na(+) . Concomitantly, instantaneous (A/E) and intrinsic (A/g(s) ) water-use efficiency (WUE) more than doubled. Stomatal conductance (g(s) ) and transpiration rate (E) exhibited a decline at 2.5 mmol dm(-3) , but remained unchanged at 4 mmol dm(-3) . Leaf nitrogen content was not impacted by Na(+) supplementation, whereas sulfur (S), calcium (Ca(2+) ), magnesium (Mg(2+) ) and zinc (Zn(2+) ) contents were maximized at 2.5 mmol dm(-3) and intermediate (30-40%) replacement levels. Leaf K(+) did not decline significantly. In contrast, leaf Na(+) content increased steadily. The resultant elevated Na(+) /K(+) ratios in tissue correlated with increased, not decreased, plant performance. The results show that Na(+) can partially replace K(+) in the nutrition of clonal cacao, with significant beneficial effects on photosynthesis, WUE and mineral nutrition in this major perennial C3 crop.     

Influence of level of nutrition during late pregnancy on reproductive productivity of red deer (2) Adult hinds gestating wapitixred deer crossbred calves

The present study aimed to relate feed intake of red deer hinds in the later stages of gestating wapitixred deer crossbred foetuses on dam body condition, gestation length, birth weight and calf growth. Multiparous hinds (N=18) conceiving at known dates to either wapiti (n=12) or red deer (n=6) sires were housed in individual pens from days 150-220 of pregnancy, during which time they were offered either ad libitum access to pelletised rations (n=6 crossbred-bearing hinds [HH] and n=6 red deer-bearing hinds [RH]) or a restricted offer (n=6 crossbred-bearing hinds [HL]) set at 70% of the average ad libitum intake of HH hind in the previous week. Hinds were returned to pasture at day 220 and calving was closely monitored. Liveweights, body condition score (BCS), and lactation score (LS) of hinds were recorded weekly from day 130 of pregnancy until calves were weaned at 12 weeks of age. Calves were tagged and weighed at birth, and subsequently weighed at 7 and 12 weeks of age. HH and RH hinds exhibited similar patterns and levels of MEI/kg0.75, which peaked at 7.8 MJME/kg0.75 at day 220. HL hinds peaked at approximately 5 MJME/kg0.75 and showed significantly lower rates of liveweight gain during pregnancy. Interestingly, both crossbred-bearing groups initiated mammary development in advance of the RH hinds. While there were significant effects of foetal genotype on mean gestation length (239 days versus 234 days for crossbred versus red deer) and mean birth weight (14.5 kg versus 10 kg), the nutritional contrast for gestation length of crossbred-bearing hinds (i.e. HH versus HL) was not significant but approached significance for birth weight (14.5 kg versus 11.9 kg; P=0.06). Regression analysis revealed weak relationships between changes in hind liveweight and gestation length (P>0.05) but a significant relationship with birth weight (P<0.05). However, change in hind BCS was significantly related to both gestation length and birth weight. Crossbred calves reared by HH hinds were 30% heavier at 7 and 12 weeks of age than the red deer calves. However, those reared by HL hinds were significantly lighter than their genotype contemporaries and only marginally heavier than the red deer calves. These results generally contrast with the previous studies on red deer hinds gestating red deer foetuses [Asher, G.W., Mulley, R.C., O'Neill, K.T., Scott, I.C., Jopson, N.B., Littlejohn, R. 2004. Influence of level of nutrition during late pregnancy on reproductive productivity of red deer, (1) Adult and primiparous hinds gestating red deer calves. Anim. Reprod. Sci., in press] and indicate that the genetically determined higher growth requirements of crossbred foetuses may override any mechanism of compensatory control of gestation length at the expense of calf birth weight. Furthermore, there were marked carryover effects of late gestational feeding on crossbred calf growth and their dam's BCS that highlight the high nutritional demands of lactation.     

Experimental induction of luteal cyclicity in roe deer (Capreolus capreolus).

Concentrations of progesterone and luteinizing hormone in plasma were analysed for two consecutive years in samples from nonpregnant female roe deer. Three animals were treated with monthly prostaglandin injections (325 micrograms cloprostenol) from October 1989 to April 1990 and from October 1990 to March 1991, and three were kept as controls. In control animals, a small increase in progesterone concentrations in July 1990 occurred at the same time as the commencement of the rut in other husbanded roe deer. In prostaglandin-treated animals, progesterone concentration was high at the time of the rut and remained so until late February 1990. After the next rut (August 1990), progesterone concentration remained high until March 1991. Between October and February-March, injections of prostaglandins induced dramatic, but temporary (lasting 72 h), decreases in plasma progesterone concentrations, indicating luteal regression and subsequent ovulation. We infer that roe deer can ovulate repeatedly and should therefore not be regarded as an obligate monoestrous species.     

贺兰山同域分布岩羊和马鹿的夏季食性

2008年78月贺兰山对同域分布的岩羊和马鹿粪便进行采集,利用粪便显微分析法对二者夏季食性进行了研究。从10个沟系中一共收集了297堆岩羊和305堆马鹿粪便,每堆中捡拾2粒粪粒,组成40个复合样本进行分析。结果表明,夏季在岩羊采食的19科35种(属)植物中,针茅(29.74%)、早熟禾(18.82%)、内蒙古邪蒿(10.30%)、灰榆(7.76%)、冰草(7.47%)是其主要食物,针茅是岩羊夏季的大宗食物;夏季在马鹿取食的11科18种(属)植物中,小红柳(36.26%)、山杨(23.10%)、灰榆(16.84%)等是其主要食物,小红柳为马鹿夏季的大宗食物。夏季岩羊采食植物中,乔木占8.67%,灌木占3.97%,禾本科草本占69.43%,非禾本科草本占17.94%;马鹿采食植物中,乔木占89.61%,灌木占5.38%,禾本科草本占1.03%,非禾本科草本占3.99%。从食物多样性和食物生态位宽度来看,岩羊的Shannon-Wiener指数高于马鹿,而马鹿的Pielou均匀性指数和食物生态位宽度指数高于岩羊,岩羊和马鹿共有9种食物重叠,生态位重叠指数为65.17%。     

Role of ATP-sensitive K+ channels in electrophysiological alterations during myocardial ischemia: a study using Kir6.2-null mice

The role of cardiac ATP-sensitive K(+) (K(ATP)) channels in ischemia-induced electrophysiological alterations has not been thoroughly established. Using mice with homozygous knockout (KO) of Kir6.2 (a pore-forming subunit of cardiac K(ATP) channel) gene, we investigated the potential contribution of K(ATP) channels to electrophysiological alterations and extracellular K(+) accumulation during myocardial ischemia. Coronary-perfused mouse left ventricular muscles were stimulated at 5 Hz and subjected to no-flow ischemia. Transmembrane potential and extracellular K(+) concentration ([K(+)](o)) were measured by using conventional and K(+)-selective microelectrodes, respectively. In wild-type (WT) hearts, action potential duration (APD) at 90% repolarization (APD(90)) was significantly decreased by 70.1 +/- 5.2% after 10 min of ischemia (n = 6, P < 0.05). Such ischemia-induced shortening of APD(90) did not occur in Kir6.2-deficient (Kir6.2 KO) hearts. Resting membrane potential in WT and Kir6.2 KO hearts similarly decreased by 16.8 +/- 5.6 (n = 7, P < 0.05) and 15.0 +/- 1.7 (n = 6, P < 0.05) mV, respectively. The [K(+)](o) in WT hearts increased within the first 5 min of ischemia by 6.9 +/- 2.5 mM (n = 6, P < 0.05) and then reached a plateau. However, the extracellular K(+) accumulation similarly occurred in Kir6.2 KO hearts and the degree of [K(+)](o) increase was comparable to that in WT hearts (by 7.0 +/- 1.7 mM, n = 6, P < 0.05). In Kir6.2 KO hearts, time-dependent slowing of conduction was more pronounced compared with WT hearts. In conclusion, the present study using Kir6.2 KO hearts provides evidence that the activation of K(ATP) channels contributes to the shortening of APD, whereas it is not the primary cause of extracellular K(+) accumulation during early myocardial ischemia.     

Control of lake trout reproduction: role of lipids

Somatic lipid density of lake trout decreased during summer and increased after spawning in October, peaking April, prior to ovarian recrudescence. Non-lipid density increased from June or July until August and remained relatively constant until March. All lake trout ( n =30) reared on high ( n =10, 0·4%), medium ( n =10, 0·15%) and low ( n =10, 0·05%) rations from March to September spawned. In a second experiment for which the treatments commenced in November, the proportion of females maturing in the following October (high=88%, medium=69%, low=28%) was positively related to ration levels.     

Effects of large-scale removal of coyotes on pronghorn and mule deer productivity and abundance

We tested the hypothesis that predation by coyotes (Canis latrans) impacts pronghorn (Antilocapra americana) and mule deer (Odocoileus hemionus) populations. We did so by examining the effects of coyote removal on pronghorn and mule deer populations within 12 large areas (>10,500 km²) located in Wyoming and Utah during 2007 and 2008. Pronghorn productivity (fawn to adult female ratio) and abundance were positively correlated with the number of coyotes removed and removal effort (hours spent hunting coyotes from aircraft) although the correlation between pronghorn productivity and removal effort was not statistically significant (P = 0.08). Mule deer productivity and abundance were not correlated with either the number of coyotes removed or removal effort. Coyote removal conducted during the winter and spring provided greater benefit than removals conducted during the prior fall or summer. Our results suggest that coyote removal conducted over large areas increases fawn survival and abundance of pronghorn but not mule deer. © 2011 The Wildlife Society.     

Uncoupling of gating charge movement and closure of the ion pore during recovery from inactivation in the Kv1.5 channel

Both wild-type (WT) and nonconducting W472F mutant (NCM) Kv1.5 channels are able to conduct Na(+) in their inactivated states when K(+) is absent. Replacement of K(+) with Na(+) or NMG(+) allows rapid and complete inactivation in both WT and W472F mutant channels upon depolarization, and on return to negative potentials, transition of inactivated channels to closed-inactivated states is the first step in the recovery of the channels from inactivation. The time constant for immobilized gating charge recovery at -100 mV was 11.1 +/- 0.4 ms (n = 10) and increased to 19.0 +/- 1.6 ms (n = 3) when NMG(+)(o) was replaced by Na(+)(o). However, the decay of the Na(+) tail currents through inactivated channels at -100 mV had a time constant of 129 +/- 26 ms (n = 18), much slower than the time required for gating charge recovery. Further experiments revealed that the voltage-dependence of gating charge recovery and of the decay of Na(+) tail currents did not match over a 60 mV range of repolarization potentials. A faster recovery of gating charge than pore closure was also observed in WT Kv1.5 channels. These results provide evidence that the recovery of the gating elements is uncoupled from that of the pore in Na(+)-conducting inactivated channels. The dissociation of the gating charge movements and the pore closure could also be observed in the presence of symmetrical Na(+) but not symmetrical Cs(+). This difference probably stems from the difference in the respective abilities of the two ions to limit inactivation to the P-type state or prevent it altogether.     

Reproductive seasonality in female Iberian red deer (Cervus elaphus hispanicus)

This study characterized the seasonal pattern of luteal cyclicity in Iberian red deer (n=16), by measuring plasma progesterone concentrations in hinds (female red deer) twice per week from calving (May and June) 1996 until May 1997. In eight of these hinds we also examined plasma prolactin profiles to assess seasonal responses to photoperiod. Plasma progesterone concentration in the 16 hinds studied indicated that the reproductive pattern is seasonal, and lasts for 5.73 +/- 0.27 months. After calving, progesterone levels remained basal (no luteal activity) for several months, except in a hind that lost her calf just after calving, and thus did not have to suckle it. This hind showed two consecutive estrus cycles in the month following calving, which suggests that suckling has an inhibiting effect on the resumption of ovarian activity. These results also showed that as long as the hinds do not become pregnant, they show between 5 and 10 estrus cycles per reproductive season (8.06 +/- 0.35), ranging between 105 and 249 days from onset of the first cycle to end of the last one. Uninterrupted cycling lasted for 3.5-6.4 months (mean, 4.6 +/- 0.24). Cyclic luteal activity was found from October to February in all hinds, with a smaller, but notable proportion in September (56.25%) and March (68.8%), whereas it was negligible in the remaining period. Our results show a reproductive season similar to or longer than that recorded by other authors. Prolactin plasma concentrations showed a yearly trend following that of photoperiod, with peak concentrations from April to July, a decrease in August, minimal concentrations from September to February and a sharp increase in March.     

Inhibition of vascular ATP-sensitive K+ channels does not affect reactive hyperemia in human forearm

The extent to which ATP-sensitive K(+) channels contribute to reactive hyperemia in humans is unresolved. We examined the role of ATP-sensitive K(+) channels in regulating reactive hyperemia induced by 5 min of forearm ischemia. Thirty-one healthy subjects had forearm blood flow measured with venous occlusion plethysmography. Reactive hyperemia could be reproducibly induced (n = 9). The contribution of vascular ATP-sensitive K(+) channels to reactive hyperemia was determined by measuring forearm blood flow before and during brachial artery infusion of glibenclamide, an ATP-sensitive K(+) channel inhibitor (n = 12). To document ATP-sensitive K(+) channel inhibition with glibenclamide, coinfusion with diazoxide, an ATP-sensitive K(+) channel opener, was undertaken (n = 10). Glibenclamide did not significantly alter resting forearm blood flow or the initial and sustained phases of reactive hyperemia. However, glibenclamide attenuated the hyperemic response induced by diazoxide. These data suggest that ATP-sensitive K(+) channels do not play an important role in controlling forearm reactive hyperemia and that other mechanisms are active in this adaptive response.     

Effects of acepromazine on capture stress in roe deer (Capreolus capreolus)

The aim of this study was to evaluate effect of a short-acting neuroleptic (acepromazine) on capture stress response in roe deer (Capreolus capreolus). Sixteen roe deer were captured by drive-nets in the winters of 1998, 1999, and 2001. Roe deer were divided into two groups: animals in the treatment group received an intramuscular injection of acepromazine (0.093 mg/kg +/- 0.003 SEM; n = 8) while animals in the control group (n = 8) did not receive tranquilizer. Heart rate and body temperature, as well as hematologic and biochemical indicators of stress, were used to evaluate effect of the neuroleptic over 3 hr. Heart rate decreased over time after capture in both groups (P < 0.05), but stabilized sooner in the treated roe deer (75 min after capture) than in the controls (105 min after capture). Body temperature decreased over 45 min and then stabilized in both groups (P < 0.05). Comparisons of blood parameters revealed significantly lower red blood cell count (RBC), lymphocyte count, hemoglobin concentration, packed cell volume (PCV), and serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatine kinase (CK), and lactate dehydrogenase (LDH) activities in tranquilized animals compared with controls (at least P < 0.05). A reduction in PCV, lymphocyte count, and serum cortisol concentrations (at least P < 0.05) and an increase in serum creatinine levels (P < 0.05) were recorded over time in control animals, while a reduction in RBC and hemoglobin concentration (at least P < 0.05) and an increase in serum urea concentrations (P < 0.05) over time were observed in the treated group. Finally, a decrease in serum lactate and potassium levels and an increase in CK, AST, ALT, and LDH activities were recorded over time in both groups. Results obtained showed the suitability of using acepromazine in capture operations in order to reduce stress response and prevent its adverse effects in roe deer. The beneficial effect was not only due to the sedative effect of acepromazine, but also to peripheral vasodilatation.     

Decreased levels of recent thymic emigrants in peripheral blood of simian immunodeficiency virus-infected macaques correlate with alterations within the thymus

The thymus is responsible for de novo production of CD4(+) and CD8(+) T cells and therefore is essential for T-cell renewal. The goal of this study was to assess the impact of simian immunodeficiency virus (SIV) infection on the production of T cells by the thymus. Levels of recent thymic emigrants within the peripheral blood were assessed through quantification of macaque T-cell receptor excision circles (TREC). Comparison of SIV-infected macaques (n = 15) to uninfected macaques (n = 23) revealed stable or increased TREC levels at 20 to 34 weeks postinfection. Further assessment of SIV-infected macaques (n = 4) determined that TREC levels decreased between 24 and 48 weeks postinfection. Through the assessment of longitudinal time points in three additional SIVmac239-infected macaques, the SIV infection was divided into two distinct phases. During phase 1 (16 to 30 weeks), TREC levels remained stable or increased within both the CD4 and CD8 T-cell populations. During phase 2 (after 16 to 30 weeks), TREC levels declined in both T-cell populations. As has been described for human immunodeficiency virus (HIV)-infected patients, this decline in TREC levels did at times correlate with an increased level of T-cell proliferation (Ki67(+) cells). However, not all TREC decreases could be attributed to increased T-cell proliferation. Further evidence for thymic dysfunction was observed directly in a SIVmac239-infected macaque that succumbed to simian AIDS at 65 weeks postinfection. The thymus of this macaque contained an increased number of memory/effector CD8(+) T cells and an increased level of apoptotic cells. In summary, reduced levels of TREC can be observed beginning at 16 to 30 weeks post-SIV infection and correlate with changes indicative of dysfunction within the thymic tissue. SIV infection of macaques will be a useful model system to elucidate the mechanisms responsible for the thymic dysfunction observed in HIV-infected patients.     

圈养獐春夏季昼间行为时间分配及活动节律

2008 年3 ～7 月,在上海市浦东新区华夏公园进行獐重引入试点,采用瞬时扫描取样法和全事件记录法,对圈养条件下24 只獐(12 雌,12 雄)春夏季昼间行为时间分配及活动节律进行了观察。结果表明:休息是春夏季最主要的行为方式,其次是摄食和运动。獐的昼间行为具有明显的节律性,以晨昏活动为主,主要活动时间集中在06:00 ～08:00 和16:00 ～18:00。单因素方差分析(One-way ANOVA analysis)和Mann-Whitney U 检验表明,在时间分配上,春、夏季休息、站立、排遗、梳理和运动行为差异极显著;雌雄间休息、站立、反刍、梳理和警戒行为差异极显著。雌性春、夏季站立、排遗、梳理、运动和社会行为差异极显著,摄食差异显著;雄性春、夏季休息、摄食、梳理、警戒和社会行为差异极显著,站立、反刍、排遗和运动行为差异显著。本研究结果表明重引入獐的行为时间分配和活动节律与野生种群相似,动物福利得到较好满足,对下一步在上海地区的种群复壮和迁地野放等具有重要意义。