Assessments of contamination and human health risks of heavy metals in the road dust from a mining county in Guangxi,China

A total of 32 road dust samples were collected from mining areas and a control area in Nandan County, Guangxi, in order to investigate the contamination characteristics of heavy metals and associated health risks to local residents. The results indicated that elevated concentrations of As, Cd, Cu, Pb, Sb, and Zn were found in road dust in mining areas compared with control areas and background values. Pearson's correlation analysis and principal component analysis indicated that As, Cd, Cu, Pb, Sb, and Zn in road dust mainly originated from anthropogenic sources (e.g., vehicles emission, mining activities, and smelting activities), whereas Cr, Co, and Ni were associated with natural sources (e.g., soil weathering). Furthermore, noncarcinogenic hazards to both adults and children were found in mining areas, while noncarcinogenic health risks in the control area were negligible. The health hazard was mostly ascribed to the ingestion, followed by the dermal contact, and the inhalation. The cancer risks from As, Cd, Co, Cr, and Ni in all studied areas were within safe levels as the R values were below the threshold of 1 × 10^?6.     

Post‐Hurricane Regeneration of Pioneer Plant Species in South Florida Subtropical Hardwood Hammocks1

After Hurricane Andrew crossed southern Florida (U.S.A.) on 24 August 1992, native and exotic pioneer species in subtropical hardwood forests (hammocks) regenerated from seed banks. Regeneration occurred in hammocks of metropolitan Dade County and the Long Pine Key region of Everglades National Park. The density of the native pioneer Trema micrantha was significantly higher in hammocks of Long Pine Key than in those of metropolitan Dade County. In contrast, the basal area of the exotic pioneer Carica papaya was greater in Dade County hammocks than Long Pine Key hammocks. Although T. micrantha tended to be restricted to areas of soil disturbance (tip‐up pits) formed by trees uprooted during Hurricane Andrew, especially in Long Pine Key, C. papaya was located throughout hammocks. These results suggest differences in the regeneration niches in which the native T. micrantha required more specific disruptions (i.e., both canopy and soil) than C. papaya (only removal of canopy) for establishment. A broad regeneration niche could in part account for the capability of an exotic species with a dormant seed bank to invade native subtropical forests following natural large‐scale disturbances.     

Additional fish recordsfrom the Judith River Formation (Campanian) of Montana

The recent recovery of additional fish remains from several fossil sites in Blaine County. Montana, allows us to add a new species of selachian and the occurrence of two genera of Chimaeriformes to the total vertebrate faunal assemblage of the Judith River Formation (Campanian).The new selachian genus is: Chiloscyllium missouriensis, a representative of the family: Orectolobidae.In association with the new orectolobid, there are representatives of the Chimaeroids: Ischyodus bifurcatusCase, and Elasmodus cf. greenoughiAgassiz.These new additions increase the total vertebratefaunnal assemblage of the Judith River Formation to twenty species.     

Cryosurgery of the monkey (macaque) prostate: I. Humoral immunologic responsiveness following cryostimulation

The effect of in situ freezing of the monkey (macaque) prostate on the development of antibodies reactive with allogeneic and autologous extract preparations of the cranial and caudal lobe of prostatic tissue and their tissue specificity were evaluated by the method of tanned cell hemagglutination. A representative percentage of the animals receiving cryosurgery developed antibodies to prostatic tissue components; however the intensity of this response was considerably modest when contrasted to that obtained following similar treatment of the rabbit prostate (coagulating gland) and generally did not appear, as in the latter, to increase to any significant degree following multiple freezing. The possible relationship of this modest humoral response to the “cryosensitivity” of the target organ and of the animals evaluated in the present study, i.e., the concentration of glandular secretions (autoantigens), physiologic state (elaboration of androgen) and immunocompetence, are considered.     

西藏4种新分布药用植物

在全国第四次中药资源普查试点之西藏自治区墨脱县野外调查中,发现西藏2个新记录属植物——球果藤属(Aspidocarya)与龙珠属(Tubocapsicum),4个新记录种植物——球果藤(Aspidocarya uvifera Hook.f.et Thoms.)、龙珠(Tubocapsicum anomalum)、毛花槭(Acer erianthum Schwer.)和清香藤(Jasminum lanceolarium Roxb.),凭证标本保存于西藏高原生态研究所植物标本室(XZE)。该次发现的植物新记录丰富了西藏的植物区系,更加深入地了解了当地的药用植物资源。     

Bacterial-resistance among outpatients of county hospitals in China: significant geographic distinctions and minor differences between central cities

The purpose of this study was to survey antibacterial resistance in outpatients of Chinese county hospitals. A total of 31 county hospitals were selected and samples continuously collected from August 2010 to August 2011. Drug sensitivity testing was conducted in a central laboratory. A total of 2946 unique isolates were collected, including 634 strains of Escherichia coli, 606 Klebsiella pneumoniae, 476 Staphylococcus aureus, 308 Streptococcus pneumoniae, and 160 Haemophilus influenzae. Extended-spectrum β-lactamases were detected in E. coli (42.3% strains), K. pneumoniae (31.7%), and Proteus mirabilis (39.0%). Ciprofloxacin-resistance was detected in 51.0% of E. coli strains. Salmonella spp. and Shigella spp. were sensitive to most antibacterial agents. Less than 8.0% of Pseudomonas aeruginosa isolates were resistant to carbapenem. For S. aureus strains, 15.3% were resistant to methicillin, and some strains of S. pneumoniae showed resistance to penicillin (1.6%), ceftriaxone (13.0%), and erythromycin (96.4%). β-lactamase was produced by 96.5% of Moraxella catarrhalis strains, and 36.2% of H. influenzae isolates were resistant to ampicillin. Azithromycin-resistant H. influenzae, imipenem-resistant but meropenem-sensitive Proteus, and ceftriaxone- and carbapenem non-sensitive M. catarrhalis were recorded. In conclusion, cephalosporin- and quinolone-resistant strains of E. coli and Klebsiella pneumonia and macrolide-resistant Gram-positive cocci were relatively prominent in county hospitals. The antibacterial resistance profiles of isolates from different geographical locations varied significantly, with proportions in county hospitals lower than those in their tertiary counterparts in the central cities, although the difference is diminishing.     

山东埕口盐场海欣分场卤虫种群生态调查

卤虫在盐田生态系统的生物调控中起着重要作用.为探讨盐田生态环境对卤虫种群的影响,选取盐度由低到高的盐池6个,采用连续定点取样、现场测量及实验室分析相结合的方法,对相关生态因子进行了调查.结果表明:卤水温度随季节变化而变化,且随卤水盐度升高而小幅增加;pH随卤水盐度升高而略有降低;卤水中叶绿素a含量与自然海水相比普遍较低(＜0.3μg·L-1);总氮和总磷浓度随卤水盐度的增加而显著升高,且较低盐度下氮为限制性元素,而较高盐度下磷为限制性元素;卤虫种群密度随卤水温度和盐度的变化而变化,在较低盐度(7 ～12°Bé)和较高温度(6-8月)下卤虫种群密度较高.分析雌雄卤虫性比表明:埕口盐场为孤雌和两性生殖卤虫混合种群,盐度和温度对孤雌和两性生殖卤虫种群密度均有一定影响;春夏季和低盐度环境下孤雌品系卤虫种群占绝对优势,而在秋季和较高盐度下两性生殖种群卤虫种群逐渐占据优势.     

新疆塔里木马鹿沙雅种群的生境变化分析

塔里木马鹿(Cervus elaphus yarkandensis)沙雅种群主要分布在新疆维吾尔自治区沙雅县和库车县境内。为了评估该马鹿种群的生境现状、变化趋势和变化原因,通过野外实地考察,利用GIS和RS技术,分别解译了当地过去4个年份(1972～2006年)夏季的Landsat TM/ETM+遥感影像,得到了塔里木马鹿生境变化数据:①2006年的农田面积为27082.24hm2,高盖度植被面积22616.25hm2,中盖度植被面积66703.62hm2,低盖度植被面积64470.62hm2,水体面积39735.89hm2,荒漠面积63497.26hm2,沙漠面积40308.45hm2;②过去的34年间农田面积增加了89.2%(12768hm2),高盖度植被面积减少60.1%(34125hm2),中盖度植被面积增加了17.2%(9791hm2),低盖度植被面积增加了37.3%(17520hm2),水体面积减少26.6%(14429hm2),荒漠面积增加6.9%(4123hm2),沙漠面积增加12.6%(4523hm2);③高盖度植被的斑块数量增加了20.9%,平均斑块面积下降了48.3%,最大斑块指数下降了33.3%;景观丰富度并没有变化,但Shannon多样性指数和Shannon均匀度指数分别增加了2.5%;④高盖度植被面积变化分别与当地的人口数量和畜牧存栏数呈显著负相关(r=-1.000),而农田、沙漠和荒漠面积分别与当地人口数量及畜牧存栏数呈显著正相关(r=0.800,r=1.000,r=0.800)。表明塔里木马鹿沙雅种群生境的丧失及破碎化程度较为严重;生境丧失及破碎化是人类活动和自然环境变化共同作用的结果。