Spatial asynchrony and periodic travelling waves in cyclic populations of field voles

We demonstrate evidence for the presence of travelling waves in a cyclic population of field voles in northern Britain by fitting simple, empirical models to spatially referenced time series data. Population cycles were broadly synchronous at all sites, but use of Mantel correlations suggested a strong spatial pattern along one axis at a projection line 72 degrees from North. We then fitted a generalized additive model to log population density assuming a fixed-form travelling wave in one spatial dimension for which the density at each site was offset in time by a constant amount from a standard density-time curve. We assumed that the magnitude of this offset would be proportional to the spatial separation between any given site and the centroid of the sampling sites, where separation is the distance between sites in a fixed direction. After fitting this model, we estimated that the wave moved at an average speed of 19 km yr-1, heading from West to East at an angle of 78 degrees from North. Nomadic avian predators which could synchronize populations over large areas are scarce and the travelling wave may be caused by density-dependent dispersal by field voles and/or predation by weasels, both of which act at a suitably small spatial scale.     

Comparative toxicity of azinphos-methyl to house mice, laboratory mice, deer mice, and gray-tailed voles

A laboratory toxicity study on house mice and laboratory mice (Mus musculus), gray-tailed voles (Microtus canicaudus), and deer mice (Peromyscus maniculatus) was conducted as part of a comprehensive laboratory and field study to field validate laboratory-based risk assessment of pesticides. The single dose oral LD50 for the organophosphorus insecticide azinphos-methyl (Guthion) was 10, 11, 32, and 48 mg/kg body weight in wild house mice, laboratory mice, gray-tailed voles, and deer mice, respectively. Ten-day dietary LC50s were 277 ppm for laboratory mice, 297 ppm for gray-tailed voles, and 1,180 ppm for deer mice. All treated animals lost more weight, consumed less food, and had depressed brain cholinesterase (ChE) activity compared to controls. Five-day LC50s were significantly higher than 10-day LC50s for laboratory mice and deer mice. For all three species, animals that died during dietary LC50 tests had mean ChE activity of 50-55% while survivors had 56-70% of controls. The conclusions were that: (1) Laboratory mice were not representative of deer mice or gray-tailed voles with respect to sensitivity to azinphos-methyl, but provided a conservative estimate for risk assessment; (2) 10-day dietary LC50 tests indicate substantially greater estimates of toxicity of azinphos-methyl to rodents than do 5-day tests; and (3) brain ChE depression of 45-50% was lethal in these species.     

A vaccinia-vectored rabies vaccine field trial: ante- and post-mortem biomarkers

During the field safety evaluation of a vaccinia-rabies glycoprotein recombinant virus vaccine for wildlife, two biomarkers were used to identify potential contact with vaccine-laden baits. Tetracycline, a commonly used and reliable calciphilic tissue marker, was included in a fish-meal polymer bait matrix and was evaluated from post-mortem bone samples. Additionally, an ante-mortem marker was needed to identify, for prospective study, raccoons which had contacted baits and thus, potentially, vaccine. Sulfadimethoxine (SDM) was included in an attractant slurry surrounding the bait, as a novel short-term seromarker. Preliminary laboratory studies in raccoons demonstrated SDM residues for up to one week following ingestion of a single 250 mg dose. During the first six days after bait distribution, 49 individual raccoons were live-trapped in the vaccination area. SDM was detectable in 38 of 49 (77.5%) serum samples. Similarly, 47 of 56 (83.9%) bone samples from raccoons collected in the vaccination area throughout the twelve-month study were tetracycline-positive. Conversely, none of the serum samples (n = 12) from the first six days of the trial nor any of the bone samples (n = 34) from raccoons in the surveillance area were biomarker-positive.     

Cytosolic isocitrate dehydrogenase in humans, mice, and voles and phylogenetic analysis of the enzyme family

In this study, we report cDNA sequences of the cytosolic NADP-dependent isocitrate dehydrogenase for humans, mice, and two species of voles (Microtus mexicanus and Microtus ochrogaster). Inferred amino acid sequences from these taxa display a high level of amino acid sequence conservation, comparable to that of myosin beta heavy chain, and share known structural features. A Caenorhabditis elegans enzyme that was previously identified as a protein similar to isocitrate dehydrogenase is most likely the NADP-dependent cytosolic isocitrate dehydrogenase enzyme equivalent, based on amino acid similarity to mammalian enzymes and phylogenetic analysis. We also suggest that NADP-dependent isocitrate dehydrogenases characterized from alfalfa, soybean, and eucalyptus are most likely cytosolic enzymes. The phylogenetic tree of various isocitrate dehydrogenases from eukaryotic sources revealed that independent gene duplications may have given rise to the cytosolic and mitochondrial forms of NADP-dependent isocitrate dehydrogenase in animals and fungi. There appears to be no statistical support for a hypothesis that the mitochondrial and cytosolic forms of the enzyme are orthologous in these groups. A possible scenario of the evolution of NADP-dependent isocitrate dehydrogenases is proposed.     

No evidence for a Y chromosomal effect on alternative behavioral strategies in mice

This study takes the first step toward testing a Y chromosomal effect on both aggression and thermoregulatory nest-building behavior in mouse lines either bidirectionally selected for short (SAL) and long (LAL) attack latency or high (HIGH) and low (LOW) nest-building behavior. Using reciprocal crosses between SAL and LAL, and between HIGH and LOW, we found no indications for Y chromosomal effects on thermoregulatory nest-building behavior. As for aggression, we confirmed earlier studies on SAL and LAL, i.e., the origin of the Y chromosome influences attack latency, i.e., aggression. However, we did not find indications for a Y chromosomal effect on aggression in the HIGH and LOW lines. Since aggression and nest-building behavior have been shown to be characteristic parameters of two fundamentally different behavioral strategies, the present data underline the improbability of Y chromosomal genes underlying the genetic architecture of alternative behavioral strategies.     

No Mycobacterium paratuberculosis detected in intestinal tissue, including Peyer''s patches and lymph follicles, of Crohn''s disease

1. The present study evaluated developmental characteristics in the chick embryo throughout incubation following cell removal from the freshly laid egg. 2. Between 10 and a few hundred cells of the blastoderm were removed for sex diagnosis. Incubation of the treated embryos was then continued in an open egg shell culture system. 3. Cell recovery from different regions within the blastoderm was performed. 4. The experiments presented here demonstrate the persistence of the developmental potential of chicken embryos in an in ovo culture system after removal of different numbers of cells from the germinal disc prior to incubation. 5. No deviations in developmental characteristics were recorded when compared to untreated control cultures. 6. No detrimental effects of double cell biopsies could be observed. 7. A similar number of chicks developed to hatch regardless of the location of manipulation within the blastoderm.     

No high affinity melatonin binding sites are detected in murine melanoma cells and in normal human melanocytes cultured in vitro

Samples of 1815 cerebrospinal fluid (CSF) were studied in a meningitis outbreak during 1989 in S?o Paulo, Brazil. Neisseria meningitis 56% with 44% type B, Haemophilus influenzae 17%, from which 72% in children (days to 3-year-old) and Streptococcus pneumoniae 14% from which 60% in children (day to 1-year-old) of 443 (24%) of all strains. Cytochemistry study showed: purulent or turbidity aspects in 70 to 79% positive bacterioscopy or culture of CSF; white cells count > 500/mm3; glucose < 45 mg/dl; protein > 90 mg/dl in 90% of all patients. We concluded that: CSF prognostic factors: (aspect and cytochemistry) were correlated with bacterial meningitis. Bacterioscopy and positive cultures were correlated to NM, SP and HI isolation from these patients (Goodman Test).     

Effect of a strong magnetostatic field on proliferation of duodenal epithelial cells in mice

The proliferative activity of duodenal epithelial cells in mice subjected to the effect of a 1000-Oe magnetostatic field (MSF) was studied. It was established that the one-day effect of a strong MSF causes transient disturbance of cell division processes. This is indicated by changes in the mitotic index and content of cells in the duodenal crypt, and also by the increase in the number of pathological forms of mitoses with a predominance of chromosomal damages.     

Body area communication based on quasi-electrostatic field and spread spectrum

Based on the electrical model of body area communication,the change tendency of channel gain in 100 kHz-10 MHz band was experimentally analyzed and verified.Results show that channel gain Was flat and signal attenuation was approximately 43 dB in 1 MHz-10 MHz band.The characteristics of the channel were taken into account in the design of body area spread spectrum communication and its multiuser receiver issue.BER-Eb/No curves of single user and multiuser were derived by simulation.The characteristics of body area commutation channel were studied and the feasibility of introducing spread spectrum theory to body area communication was verified.     

Lack of a co-promoting effect of a 60 Hz magnetic field on skin tumorigenesis in SENCAR mice

It has been proposed that extremely low frequency (ELF) magnetic fields may enhance tumorigenesis through a co-promotional mechanism. This hypothesis has been further tested using the two-stage model of mouse skin carcinogenesis, i.e. 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced promotion of skin tumors in mice initiated by a single subcarcinogenic dose of 7,12-dimethylbenz[a]anthracene. Experimentation described herein utilized the SENCAR mouse and examined the effect of a magnetic field on skin tumor promotion induced by three different doses of TPA within its dose-response range, i.e. 0.85, 1.70 or 3.40 nmol, administered twice per week. SENCAR mice (56/treatment group) were exposed to a 60 Hz magnetic field having a flux density of 2 mT for 6 h/day for 5 days/week and compared with mice exposed to the ambient magnetic field. Tumor incidence and multiplicity were monitored weekly for 23 weeks of TPA promotion. Statistical evaluation of the effects of the magnetic field on tumor incidence and multiplicity did not reveal any statistically significant effects; thus, within the sensitivity limits imposed by the animal model and the exposure parameters employed, no promotional or co-promotional effect of a 2 mT magnetic field on skin tumor development in SENCAR mice could be demonstrated.     

Telomerase activity detected in pancreatic juice 19 months before a tumor is detected in a patient with pancreatic cancer

We report a patient with pancreatic cancer in whom telomerase activity had been detected in the pancreatic juice 19 months before he was diagnosed as having pancreatic cancer. A 61-yr-old alcoholic man complaining of epigastric and back pain was diagnosed as having groove pancreatitis based on the presence of inflammation in the pancreatic head and its extension to the duodenal mucosa with an associated elevated serum amylase level. All imaging modalities showed no sign of a tumor. However, high telomerase activity was detected in the pancreatic juice collected during endoscopic retrograde pancreatography. His symptoms subsided due to abstinence from alcohol. A tumor, however, was recognized on computed tomography 19 months later, at which time the patient immediately underwent a pylorus-preserving pancreaticoduodenectomy. The carcinoma was located mainly in the Santorini duct region. High telomerase activity in the pancreatic juice may precede clinical detection of pancreatic cancer and thus could be a useful early diagnostic marker for pancreatic cancer.     

Persistence of humoral immunity to rabies 1100 days after immunization and effect of a single booster dose of rabies vaccine

OBJECTIVES: To investigate the relationship between excessive endogenous production of nitric oxide (NO) and the low systemic vascular resistance (SVR) syndrome after cardiac surgery. DESIGN: Prospective, case-control. Cases defined by low SVR postoperatively (< 750 dyn/s/cm-5), and matched with controls (> 900 dyn/s/cm-5). SETTING: Cardiothoracic intensive care unit (ICU) in a tertiary care hospital. PARTICIPANTS: Forty-four patients after cardiac surgery. INTERVENTIONS: Collection of plasma and urine samples after identification. MEASUREMENTS AND MAIN RESULTS: Plasma and urine nitrate concentrations were measured as an index of endogenous NO production. Hemodynamic, inotropic, and outcome data were collected. Median nitrate concentrations did not differ between cases and controls (plasma, 58 mumol/L, v 62 mumol/L, p = 0.43; urine, 399 mumol/L v 404 mumol/L, p = 0.38). Times to extubation and intensive care unit (ICU) discharge were prolonged in patients with low SVR (17.8 hours v 8.7 hours, p = 0.021; 2.5 days v 1.2 days, p = 0.019, respectively). CONCLUSIONS: No association between "low SVR syndrome" and endogenous NO production was found. Patients with low SVR after cardiac surgery required a longer period of inotropic and ventilator support, with delay in discharge from the ICU. The risk and cost implications of this syndrome support further research.     

Intermittent 50 Hz magnetic field and skin tumor promotion in SENCAR mice

Hysteroscopic surgery has been widely used in gynaecology for the treatment of endocavitary fibroids, synechias, uterine septum and abnormal uterine bleeding. Reports proposed preoperative medical therapy to improve the endometrials conditions. Attempts at inhibiting the thickness and vascularity of the endometrium and to reduce the fibroids size in preparation for hysteroscopic surgery by using different types of hormones have been reported. The suppression provided for a long period of time after the procedure by gonadotropin releasing hormone (GnRH) analogs, is likely to help inhibit endometrial regeneration and provided even better long time success, in endometrial ablation and submucous leiomyomatas hysteroscopic surgery. A literature review of the efficiency of the gonadotropins releasing hormone agonist, in endometrial inhibition before surgery and small regional experience is shown.     

Species differences in V?a receptor gene expression in monogamous and nonmonogamous voles: Behavioral consequences.

Arginine vasopressin modulates a number of species-typical social behaviors, including social memory in rats, scent marking and aggressive behavior in hamsters, and partner preference formation and paternal behavior in monogamous rodents. The distribution of V?a receptor binding sites in the brain varies greatly among species. Using in situ hybridization in 2 species of voles with strikingly different patterns of V?a binding sites and social behaviors, the authors demonstrate that differences in V?a receptor binding sites are due to species differences in regional V?a receptor gene expression. It is then demonstrated that the differences in receptor gene expression are associated with species differences in behavioral response to centrally administered vasopressin. Together, these data suggest that the phylogenetic plasticity of central neurohypophyseal peptide receptor expression may contribute to the evolution of species-typical social behaviors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

No apparent influence of immunoglobulins on indigenous oral and intestinal microbiota of mice

The role of secretory immunoglobulin A (sIgA) in the control of the indigenous microbiota is not well understood. In this study, we compared the oral and intestinal microbiota of transgenic B-cell-deficient (microMT) mice with their heterozygous (microMT/+) normal littermates. The levels of salivary IgA and serum IgA and IgG were normal in microMT/+ mice, while no immunoglobulins were detected in microMT/microMT mice. The acquisition and proportions of the different species of the oral and intestinal indigenous bacterial populations were not significantly different between the two groups of mice. Our results thus suggest that secretory IgA does not play a major role in the regulation of the indigenous microbiota of mice.     

Causes and consequences of natal dispersal in root voles, Microtus oeconomus

To test the causes and consequences of variation in natal dispersal in root voles we released 53 matrilines (mothers with newly weaned litters) separately in field enclosures, during nine consecutive periods. The matrilines could disperse and distribute themselves among three pre-emptied habitat patches. Two dispersal measures were recorded: short-distance dispersal defined as individuals immigrating to a neighbouring patch, and long-distance dispersal defined as unsettled individuals captured along the fence of the enclosures. We analysed the role of social factors (i.e. maternal and litter characteristics), habitat quality (i.e. seasonal effect) and experimentally manipulated shape of the natal patch in dispersal. The consequences of dispersal were analysed with respect to the spatial distribution of kin, and to pregnancy in females and sexual maturation in males. Dispersal was unrelated to patch shape. In agreement with the inbreeding avoidance hypothesis, long-distance dispersal was male biased and philopatric males were most frequently reproductively inactive. Whilst young males avoided their mother, they seemed to disperse, settle and mature sexually independently of their sisters. In agreement with the resource competition hypothesis, young females avoided their mother and were most frequently reproductively inactive when residing in their mother's patch. We conclude that inbreeding avoidance was underlying the male dispersal pattern. For females, long-distance dispersal was most in agreement with the inbreeding avoidance hypothesis while short-distance dispersal could be explained by the resource competition hypothesis. (c) 1998 The Association for the Study of Animal Behaviour.     

Bone marrow cellular composition in Listeria monocytogenes infected mice detected using ER-MP12 and ER-MP20 antibodies: a flow cytometric alternative to differential counting

We examined whether apoptosis is involved in hypoxic cell death using primary cultures of rat cortical neurons and whether the cell death is associated with changes in Bcl-2 and Bax expressions and activities of caspases. Hypoxic insult accelerates apoptosis, as shown by apoptotic nuclei and by chromatin degradation of internucleosomal fragments. This apoptotic process is accompanied by a rapid and sustained down-regulation of Bcl-2, whereas levels of Bax are unchanged. Furthermore, hypoxic insult activates sequentially caspase-1-like and caspase-3-like proteases, following down-regulation of Bcl-2 expression. Peptide inhibitors of either caspase-1 or caspase-3 protect against neuronal death, although they do not prevent hypoxia-induced down-regulation of Bcl-2. Furthermore, treatment of cortical neurons with either insulin-like growth factor-1 (IGF-1) or basic fibroblast growth factor (bFGF), growth factors which are implicated to prevent neuronal loss in ischemic brain, partly prevented neuronal death accompanied by inhibition of alterations in Bcl-2 protein levels and caspase-3-like activities. These results suggest that hypoxia induces neuronal death by down-regulation of Bcl-2 protein levels followed by sequential activation of the caspases, and the protection from neuronal cell death of these growth factors under hypoxic conditions derives at least partly from their capability to prevent down-regulation of the anti-apoptotic protein levels.     

三塘湖地区某矿区水文地质研究

三塘湖地区位于哈萨克斯坦-准噶尔板块(Ⅱ)一级构造单元,二级构造单元属准噶尔微板块(Ⅱ1),三级构造单元为三塘湖晚古生代弧间盆地(Ⅱ14)。已探明的地下水类型主要为松散岩类孔隙潜水及碎屑岩类裂隙孔隙水,由上至下根据地层时代可分为第四系松散岩孔隙潜水、古近-新近系碎屑岩类裂隙孔隙水、白垩系碎屑岩类裂隙孔隙水、侏罗系碎屑岩类裂隙孔隙水,现对三塘湖地区某矿区水文地质特征展开分析与研究,希望能为相关工作的开展提供一定的参考作用。