Links between the structure of an Antarctic shallow-water community and ice-scour frequency

Ice is a major structuring force in marine and freshwater environments at high latitudes. Although recovery from scouring has been quantified in time, the frequency of scouring in the Antarctic has not. We placed grids of markers at 9–17 m depth at two sites, to study ice-scouring over 2 years at Adelaide island (Antarctic Peninsula). We quantified the time scale of scour frequencies, and linked this to community mortality, age and diversity. Markers were hit from zero to at least three times in 2 years. At the least disturbed site (South Cove) 24% of markers were destroyed per year, whereas in North Cove 60% of markers were destroyed. There were significant differences in scouring frequency between our two sites: a given area in North Cove was on average hit twice as often as one in South Cove. Compared with near shore environments elsewhere, faunas of both sites were characteristic of high disturbance regimes, exhibiting low percent cover, diversity, ages and a high proportion of pioneers. Aspects of the encrusting communities studied reflected the differences between site disturbance regimes. North Cove was scoured twice as often, and bryozoan communities there had half the number of species, two-thirds the space occupation and twice the mortality level of those in South Cove. Maximum age in North Cove bryozoans was also half that in South Cove. Although there are natural disturbance events that rival ice-scouring in either frequency or catastrophic power at lower latitudes, none do both nor across such a wide depth range. We suggest that ice scour effects on polar benthos are even more significant than the same magnitude of disturbance at lower latitudes as recovery rates of high latitude communities are very slow. Climate warming seems likely to increase iceloading of near shore polar waters, so that some of the worlds most intensely disturbed faunas may soon suffer even more disturbance.     

Ventilatory conditioning by self-stimulation in rats: A pilot study

This article describes an experimental attempt to condition breathing pattern in rats. In this experiment, a freely moving rat was first rewarded by an electrical stimulation of the medial forebrain bundle whenever inspiratory duration (TI) exceeded 300 ms. A bidirectional control was then used: TIs longer than 400 ms were rewarded, and then TIs shorter than 300 ms were rewarded. The frequency of TIs longer than 300 ms increased when this event was rewarded, further increased when TIs above 400 ms were rewarded, and decreased during reversal conditioning (TI < 300 ms). At the beginning of the experiment, stimulation caused increased arousal and motor activity, but after prolonged conditioning, the brain stimulation was associated with quiet wakefulness. Although the general procedure appears to be well-suited to the experimental study of voluntary breathing, some possible improvements are suggested for further, more extensive investigations.We are grateful to Professor Claude Gaultier and to Professor Vincent Bloch for their support, to Pascale Leblanc for her invaluable assistance, and to Gerard Dutrieux and Michel Vigouroux for their technical contribution. This work was supported by the Université de Paris-Sud (Grant AI-9023) and by the Institut National de la Sante et de la Recherche Médicale (CJF 89-09).     

Home ranges of introduced rats on Christmas Island: A pilot study

Understanding the spatial ecology of invasive rats (Rattus spp.) is necessary to inform management actions to reduce their impact on native flora and fauna. This study investigates home range sizes of exotic rats around seabird colonies and urban areas on Christmas Island, where rat predation is suspected to be adversely affecting fledgling success among local seabirds. It was hypothesised that rat home range sizes would be smaller in urban areas owing to more consistent food availability. Home ranges of male rats were significantly larger compared with their female counterparts, with male rats maintaining larger home ranges in urban areas compared with seabird colonies. Conversely, female rats had smaller home ranges in urban areas compared with seabird colonies. Our findings suggest a possible correlation between the spatial distribution of food resources and home range size. Additionally, the spatial distribution of breeding females across the landscape had a significant influence on the home ranges of male rats. These findings have important implications for proposed efforts to manage rat populations on Christmas Island, while also providing valuable information regarding the ecology of invasive rats on tropical islands.     

初生与成年牦牛心肌的组织学结构比较

为探究牦牛心肌发育过程中组织学结构的变化,采用组织学、组织化学和免疫组织化学方法对初生和成年牦牛心肌的组织学结构、心钠素（ANP）和缝隙连接蛋白43（Cx43）的表达情况进行了观察。结果显示,初生牦牛心肌细胞数量少且细短,闰盘为直线型或V型,心肌细胞间以Ⅲ型胶原纤维为主,Ⅰ型胶原纤维较少;成年牦牛心肌细胞粗长,其数量是初生牦牛的2倍,闰盘呈竹节样吻合或阶梯状,心肌细胞间以Ⅰ型胶原纤维为主。初生和成年牦牛,ANP在心房肌细胞中均表达强烈,且右心房表达量显著高于左心房,心室肌细胞中不表达。ANP在普肯耶纤维中有少量表达。初生牦牛心房肌细胞ANP表达量高于成年牦牛。在心肌细胞膜和胞质内,初生牦牛Cx43表达强于成年牦牛,但在闰盘内,成年牦牛Cx43表达强于初生牦牛。Cx43在初生和成年牦牛的普肯耶纤维中均呈膜阳性。结果提示,初生与成年牦牛相比,成年牦牛的心肌细胞变粗长且数量增多,ANP在心房肌表达减弱,Cx43在闰盘表达更显著,说明成年牦牛较初生牦牛适应循环变化的代偿能力呈进行性减弱;细胞间牢固性增加,有助于实现心肌收缩信号的迅速传导。     

Effect of dolomite on the repair of bone defects in rats: histological study

The aim of the present study was to evaluate histologically and radiographically the tissue response to dolomite [CaMg(CO3)2] and its osteogenic potential in the repair of bone cavities in the calvaria of rats. A bone defect 10 mm in diameter and 1 mm deep was made in the calvaria of male Wistar rats. The defects were filled with dolomite, inorganic bovine bone (positive control), or coagulum (negative control). The animals were euthanized 7, 15, 30, and 60 days after surgery, and specimens were collected for radiographic and microscopic analyses. The bone defects were processed for paraffin embedding and H&E staining. The histological study revealed that dolomite stimulated a moderate inflammatory response, with programmed cell death in the first 15 days, compared to bovine bone which showed a moderate to intense acute response. In the chronic phase, the inflammatory response was characterized by the occurrence of macrophages organized as epithelioid cells in the dolomite group, and giant cells in the bovine-bone group. Fibrosis developed in all three groups; however, encapsulation of the fragments, reabsorption, and osteoconductive activity occurred only in the defects filled with bovine bone. The radiographic analysis showed that the bovine bone was most efficient in the repair of the defects, followed by the dolomite and the coagulum. This study demonstrated that the dolomite stimulated a moderate acute inflammatory response with programmed cell death, and a chronic inflammatory response by means of the phagocytic mononuclear system. Although osteo-conductive activity was not shown, the dolomite favored the repair process, compared to the coagulum group.     

Evidence for phylogeographic structure in Lolium species related to the spread of agriculture in Europe. A cpDNA study

In order to explain the present distribution area of natural populations of two forage grasses species (Lolium perenne and L. rigidum), we studied genetic variation for maternally inherited chloroplast DNA (cpDNA) in 447 individual plants from 51 natural populations sampled throughout Europe and the Middle East. The detection of polymorphism by restriction analysis of PCR-amplified cpDNA fragments resulted in the identification of 15 haplotypes. Hierarchical analysis of chloroplastic diversity showed a high level of within-population diversity while, for both species, we found that about 40% of the total diversity still remains among populations. The use of previous isozymes data enabled us to estimate the pollen to seed flow ratio: pollen flow appears to be 3.5 times greater than seed flow for L. perenne and 2.2 times higher for L. rigidum. A stepwise weighted genetic distance between pairs of populations was calculated using the haplotypes frequencies of populations. A hierarchical clustering of populations clearly divides the two species, while two main clusters of L. perenne populations show a strong geographical structure. Different scenario are proposed for explaining the distribution area of the two species. Finally, evidence attesting that these geographical structures are related to the spread of agriculture in Europe are presented and discussed. Received: 5 November 1999 / Accepted: 24 November 1999     

阜阳地区居室环境中粉螨的群落组成和多样性

目的调查安徽省阜阳地区居室环境中粉螨的群落组成和多样性。方法于2009年7月,选择100户家庭进行样本采集,每居室环境中取4个采样点,对采集到的地面灰尘、床面灰尘、家具灰尘及衣物灰尘进行粉螨的分离、鉴定、计数和数据分析。结果共检获粉螨3609只,隶属于6科15属,共19种。对4类居室灰尘中粉螨群落多样性分析表明:它们的丰富度指数为0.89~2.09,多样性指数为1.28~1.83,均匀度指数为0.65~0.71。结论粉螨群落的结构及多样性与其生境条件直接相关;阜阳地区人居环境粉螨孳生密度较高(48.5%),应加强防螨措施。     

A histological study of cutaneous glands in the brown brocket deer

We examined the histological structure of 8 skin areas thought to contain cutaneous glands of potential importance in scent communication in 16 brown brocket deerMazama gouazoubira Fisher, 1814, using standard histological techniques. Frontal areas and preorbital sacs had scant glandular development. Sebaceous gland development was prominent in vestibular nasal glands and prepucial glands. Apocrine sudoriferous glands and sebaceous glands were well developed in tarsal glands, the caudal skin area and the interdigital glands of front and hind feet. The tail had a unique arrangement of apocrine sudoriferous glands. Anal glands had moderate glandular development, and metatarsal glands were absent. Several of these glandular areas may be important in the chemical communication among brocket deer.     

Inpatient admissions and outpatient appointments in the first year post cancer diagnosis: A population based study from England

BackgroundTime spent in hospital (length of stay) is an important component of patient experience and the financial cost of cancer care. This study documents the length of stay across English cancer diagnoses at a national level and reports on variation by patient demographics and tumour characteristics.MethodsData on all diagnoses of malignant neoplasms from the English National Cancer Registration and Analysis Service for 252,202 patients first diagnosed in 2015 was linked with NHS Digital’s Admitted Patient Care and Outpatient Hospital Episode Statistics datasets to quantify length of stay within one year following diagnosis. Length of stay was modelled using linear regression adjusted for sex, age, tumour type, stage, time spent alive during the study period, vital status at end of study period, region, deprivation and ethnicity.ResultsPatients spend a mean of 25 days (median = 17 days; IQR = 8–34 days) in hospital in their first year. Tumour type, stage, age and vital status corrections had the strongest effects in the model adjusting for other independent variables. Younger patients tended towards longer stays.ConclusionLength of stay varies among patients by tumour type, age and stage. Estimating future health service demands should account for changes in incident tumour characteristics.     

Influence of the habitat change for birds on community structure

In order to study the influence of habitat change on the community structure of birds, the species and individual numbers in the lakeside developmental land of Thousand-Island Lake have been recorded since January 2009 till December 2010, A fixed sample line was set up in the studied area, and the primary data was obtained about twice a month. In 2009, 1814 individuals were observed belonging to 12 orders, 31 families and 78 species, among which 4 species (Milvus lineatus, Haliastur Indus, Circus cyaneus and Glaucidium cuculoides) are the rank II national key protected species. In 2010, 872 individuals were recorded belonging to 12 orders, 33 families and 77 species, among which 2 species (Milvus lineatus and Glaucidium cuculoides) are the rank II national key protected ones. The total individual number of birds reduced 51.9%. Concerning the species, although the total species number decreased rarely after the habitat change, 23 species fled away and 22 species entered indicating the population similarity index value of 0.55. Among the top 10 species with large number of individuals, 5 species (Spizixos semitorques, Pycnonotus xanthorrhous, Paradoxornis webbianus, Passer montanus and Carduelis sinica) were overlapped indicating the similarity index value of 0.5. Comparison of the data of the corresponding months between two years, the highest similarity (index value > 0.6) was from January to February; and the lowest (index value < 0.3) from March to May. From June to December, the similarity index value was rebounded to 0.35–0.52 might due to the food tempt. Among the 55 overlapped species, 17 species (Tachybaptus ruficollis, Egretta garzetta, Phasianus colchicus, Streptopelia orientalis, Hirundo rustica, Hirundo daurica, Motacilla alba, Spizixos semitorques, Pycnonotus xanthorrhous, Pycnonotus sinensis, Urocissa erythrorhyncha, Paradoxornis webbianus, Prinia inornata, Passer rutilans, Passer montanus, Lonchura punctulata and Carduelis sinica) showed significant differences in individual number between the unchanged habitat and the changed habitat, including 2 species of water birds and 15 species of forest birds, which indicate these two types of birds were more affected than the others. In other words, the birds living close to the human crowds suffered bigger effect than the birds living away from the crowds. This is considered that the vocals, vehicle and machinery noises, and artificial constructions contributing to habitat change might be one of the main factors. All these analysis suggest the great influence of habitat change caused by human on the bird community structure. The higher diversity, richness and evenness index values in 2010 than in 2009 suggests that environmental modification led to a certain degree of habitat amelioration. Therefore, human being can improve environment by making the plant community structure complexity to increase the habitat heterogeneity, and consequently enhancing the diversity of bird community, as long as the habitat is not fragmented.     

A pilot study on the prevalence of maternal obesity in selected Greek counties

ObjectiveTo report a pilot prevalence of maternal overweight, obesity and underweight in selected Greek counties.MethodsA total of 441 adult childbearing women were recruited from maternity clinics in 6 Greek counties for this cross-sectional study. Pre-gravid weight status was defined according to the WHO cut-offs and gravid weight status was diagnosed with the Mardones and Rosso weight gain chart.ResultsDuring gestation the majority of the participants were of normal body weight (BW) (34.0%), obesity was apparent in 25.6% of the sample, 23.8% of the participants were underweight, and the remaining 16.6% were overweight. Overall, pregnancy tripled the prevalence of underweight, increased the prevalence of obesity (by 388.0%) and decreased the number of participants in the normal BW category (p ≤ 0.001 for all). The majority of participants classified in each pre-gravid weight-category remained in the same weight category during their gestation. All the pre-gravidly obese women were also obese during pregnancy. Underweight was more prevalent in Kavala (37.5%) and obesity was more frequent in Thessaloniki (30.8%). Women who were overweight prior to conception were highly likely to be overweight/obese during pregnancy (OR: 23.8, CI: 11.1–51.0).ConclusionsThe results indicate a high prevalence of overweight, obesity and underweight among pregnant women in Greece.