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1.
María Aurora Armienta Violeta Mugica Isabel Reséndiz Mirella Gutierrez Arzaluz 《Journal of Soils and Sediments》2016,16(4):1267-1278
Purpose
Mining wastes may cause important environmental impacts in soil, water, and air due to their high metals and arsenic contents. The aim of this work was the assessment of the mobility of arsenic and several heavy metals in soils located near different types of tailing heaps in the town of Zimapán, México.Materials and methods
One hundred twenty soil samples were collected nearby to three tailing heaps, one oxidized presenting a red color (RT), and two with gray wastes (OSM and NSM) but with different age, during the dry and rainy seasons at the surface and to 40 cm depth, as well as to different distances from the deposits. Arsenic, Cd, Cu, Fe, Mn, Pb, V, and Zn total concentrations were determined; in addition, geochemical phase distribution of As, Cu, Mn, and Zn in selected samples was determined by sequential extraction. Concentrations were measured by graphite furnace atomic absorption spectrometry and inductively coupled plasma. To interpret the results, statistical analyses were performed.Results and discussion
All samples presented high As concentrations reaching more than 50,000 mg kg?1 close to OSM tailings, although the highest concentrations in the available fractions were measured in NSM impacted soils. Arsenic and metals concentrations exceeded the screening limits recommended for industrial sites. In samples influenced by OSM tailings, most of the elements analyzed were in the residual fraction, whereas in NSM and RT they were mostly in the organic and sulfide fractions and in the Fe and Mn oxides fractions, respectively. Larger concentrations of As and metals than those allowed by the screening values in Canada and the Netherlands were measured in the residential area representing a health threat for the inhabitants and the environment.Conclusions
Acid mine drainage, water, and wind erosion of tailings have polluted nearby soils. Higher concentrations of As and metals were measured during the rainy season in gray tailings impacted soils and during the dry season in red tailings, showing both deposit types’ different mobility. Elements fractionation in soils depends mainly on tailings characteristics. Low metals and As proportions were found in the fraction with the highest mobility. Metals and arsenic are more stable in soils impacted by gray tailings, mainly in the organic and sulfides and residual fractions, while in RT, most are linked to Fe and Mn oxyhydroxides. Polluted soils in residential areas constitute a health hazard. Remedial actions must be taken to stop the population exposure.2.
Eduardo Reséndiz Sergio Flores-Ramírez Volker Koch Amaury Cordero-Tapia 《Journal of aquatic animal health》2016,28(4):252-257
Fibropapillomatosis (FP) is characterized by multiple fibroepithelial tumors in all parts of the skin and has been reported in sea turtles worldwide. Clinically infected individuals are often emaciated and anemic. In Mexico, however, there are few records of this disease. In this study of green turtles Chelonia mydas in Laguna San Ignacio in Baja California Sur (BCS), we noted one juvenile with multifocal fibropapilloma lesions on the external upper surface of its eyes and hind flippers. Light microscopy revealed hyperkeratosis, epidermal hyperplasia, dermal papillary projections, and fibroblast proliferation. Electron microscopy revealed viral particles. Biopsies of normal skin were done to determine the origin of the turtle through genetic analysis. Its mitochondrial DNA matched that of a haplotype (CMP2) from a Hawaiian green turtle population. Finding FP in a turtle captured in BCS elucidates the need for further monitoring along the west coast of Mexico. Further investigation should include testing tumors to detect and characterize any chelonid herpesviruses and explore any association with FP and other diseases that pose a health risk to other sea turtle species.
Received March 26, 2016; accepted August 3, 2016 Published online October 27, 2016 相似文献
3.
闽北山垄田稻萍鱼共生体系与萍体氮素循环利用效率研究 总被引：1，自引：0，他引：1
将稻－萍－鱼共生体系的综合耕作技术引入山垄稻田。试验结果表明:山垄稻田中草鱼、尼罗罗非鱼以红萍为饵食,其鲜鱼产量分别达3568kg／hm2和3702kg／hm2;中稻和再生稻产量分别达5710～6006kg／hm2和3478～3772kg／hm2,比施化学氮肥处理区分别提高689．0～1132．5kg／hm2和458．4～658．9kg／hm2。15N试验结果显示:在稻萍鱼体系中鱼体和水稻对红萍氮总利用率达52．8％～57．9％．而施用化学氮肥处理区的水稻对氮素利用率仅为33．5％。连续两年实施稻萍鱼共生体系耕作技术．山垄田土壤有机质平均提高0．15％,且整个耕作体系病情指数下降42．1％～50．7％．减少农药施用量,有助于生态环境改善,达到增产增收的目的。 相似文献
4.
The effect of stress on haematologic response and physicochemical parameters of muscle meat in rabbits 
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下载免费PDF全文 V. Reséndiz‐Cruz J. E. Ramírez‐Bribiesca D. Mota‐Rojas I. Guerrero‐Legarreta R. G. Cruz‐Monterrosa D. Hernandez‐Sanchez 《Journal of animal physiology and animal nutrition》2018,102(1):e403-e412
Ante‐mortem studies of stress in rabbits are few and can potentially impact the haematologic response and physicochemical parameters of muscle meat. The aim of this study was to investigate the induction of stress by transport and simulation at two different times. Two hundred rabbits divided in a similar proportion of male and female were stressed by vehicular transportation and with motion simulation, using a vibration platform. They were divided into five groups: Control (without stress), Stress with Short Transportation (30 min), Stress with Long Transportation (60 min), Stress with Short Vibration Platform (30 min) and Stress with Long Vibration Platform (60 min). Transportation caused a decrease in the haematic potassium in both sexes (<5.2 mmol/L). The glucose and lactate concentrations increased in the transported rabbits (>219 and >61 mg/dl respectively). The differences between sexes showed that the PCO2 in males decreased <8.5 mmHg in stress groups compared to without stress group. Glucose concentration was 61.5 mg/dl for females and 38.0 mg/dl for males (p < .01). We concluded that in rabbits induced stress by transport increased the energetic metabolites in the blood tissue. This increase did not affect the production parameters and the quality of muscle meat. 相似文献
5.
After oil spills, oiled wildlife are regularly cleaned at considerable cost. Yet the conservation value of this intervention has been questioned, mostly because cleaned animals appear to have poor post-release survival. However, reliable long-term data are needed to judge the success of such programs. We used 16 ring recoveries to estimate survival of 932 Cape gannets (Morus capensis) that were oiled, cleaned and released in 1983. For the period 1989-2006, we further compared survival of 162 surviving cleaned gannets to that of 10,558 non-oiled gannets using capture-recapture data. We used modern statistical tools that account for recapture probabilities, recovery rates, transience, and temporary absence from the breeding colonies. Mean annual survival rates of de-oiled gannets ranged from 0.84 (se = 0.05) to 0.88 (se = 0.02), depending on analysis and colony. Between 1989 and 2006, rehabilitated gannets survived slightly less well than unoiled birds, but the difference was similar to the difference in survival between the two colonies where the birds were studied. Our results show subtle long-term effects of oiling and subsequent treatment. However, they also show that cleaned gannets can survive at almost the same rate as unoiled birds, at least if they survived the initial years after release. Rehabilitation of these birds may thus be a valuable conservation intervention for this localised species where a single spill can threaten a large proportion of the world population. 相似文献
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7.
棉花密植、化调、水肥综合配套高产栽培技术研究 总被引：2，自引：1，他引：2
利用密植、化调、水肥等综合栽培技术。进行了协调棉株生育的研究。试验结果表明,10.5万株/hm~2,DPC 90g/hm~2,N、P_2O_5、K_2O 为225、180、135kg/hm~2,盛蕾期浇头水的处理,可以达到株高65～70cm、果枝数10个、果节数3个的株型,形成铃期不封垄、通风透光好的群体结构;叶片的同化能力和根系的活性均较强,在棉株群体、生态环境和棉株体内库源流之间形成了协调的关系。因此,群体的成铃强度达到了4.68万个/hm~2·日,皮棉产量达到了1875kg/hm~2,经济系数达到了0.4以上。 相似文献
8.
棉花抗虫性状与抗虫效果分析 总被引：9，自引：0，他引：9
本文探讨了具有单一或复合抗虫性状的陆地棉(Gossypium hirsutum.),对黄淮海棉区严重危害棉花的棉蚜(Aphis gossypii)和棉铃虫(Heliothis armegera)的抗性效果,并对不同抗性品系在虫害胁迫下的抗虫性进行了初步研究。结果表明,多茸毛性状抗棉蚜性最好,光叶抗性较差,生化抗性对棉铃虫抗性最好。由于蜜腺性状的复杂性,无蜜腺对棉蚜有一定抗性,但在田间棉铃虫自然发生条件下抗性不明显。所有具抗虫性状的品系均不同程度地优于常规品种。培育兼抗上述两虫的棉花新品种,以多茸毛和生化抗性结合较理想。幼叶和幼蕾棉酚含量高对减轻棉铃虫危害有一定效果。利用裂区设计和平均生产力(MP)、产量损失(L)和耐害率(PP)对评价不同棉花种质的抗棉铃虫性具有一定价值。 相似文献
9.
Large termitaria act as refugia for tall trees,deadwood and cavity-using birds in a miombo woodland 总被引：1，自引：1，他引：0
Grant S. Joseph Graeme S. Cumming David H. M. Cumming Zacheus Mahlangu Res Altwegg Colleen L. Seymour 《Landscape Ecology》2011,26(3):439-448
Landscape heterogeneity can play an important role in providing refugia and sustaining biodiversity in disturbed landscapes.
Large Macrotermes (Isoptera) termite mounds in miombo woodlands form nutrient rich islands that sustain a different suite of woody plant species
relative to the woodland matrix. We investigated the role of termitaria in providing habitat for cavity-using birds in miombo
woodlands that had been greatly impacted by elephants and fire, by comparing the availability of habitat favored by cavity-using
birds (tall trees, trees with deadwood, and cavities) on and off mounds, and then testing its effect on species richness and
abundance of cavity-using birds. We surveyed 48 termitaria paired with 48 woodland matrix sites in the breeding season; and
54 matrix-termitarium pairs in the non-breeding season in Chizarira National Park, Zimbabwe. Generalized linear mixed-effects
models showed that termitaria harboured significantly higher densities (ha−1) of habitat components considered important for cavity nesting birds. Density of trees >6 m in height and incidence of trees
with deadwood was nearly 10 times greater on mounds than in the matrix, and the density of cavities was nine times higher
on mounds compared to the matrix. A model selection procedure showed that termitaria provided refugia for cavity-using birds
and contributed to the resilience of bird communities through high on-mound densities of trees with deadwood. Large termitaria
thus appear to play an important role in maintaining functionally important components of the avifauna in heavily impacted
Miombo woodlands. 相似文献
10.
不同供氮水平下小麦苗期叶绿素含量的QTL及互作研究 总被引：11，自引：3，他引：11
由小麦近缘物种硬粒小麦和节节麦发展而来的W7984和现代栽培种Opata.85作亲本,通过一粒传而获得F7重组近交系(RIL)群体。对该群体的111个株系分别在正常供应氮素(N.4.0mmol/L)和低氮胁迫(N.0.4mmol/L)两种情况下进行培养,4周后测定叶片叶绿素含量。根据该群体而构建的遗传图谱包括覆盖整个染色体组的918个RFLP(限制性片段长度多态性)标记,应用这些标记,研究了两种供氮情况下小麦叶片叶绿素含量的QTL(数量性状基因位点)及基因间互作。结果表明,在氮素正常供应情况下,有7个与叶绿素含量有关的QTL,变异解释率在4.30％～13.45％,亲本双方对于叶绿素含量的贡献基本一致;在氮素胁迫下,有9个QTL与叶绿素含量有关,变异解释率在4.04％～11.73％,亲本W7984.对于叶绿素含量的贡献占主导地位。表明小麦近缘物种在低氮胁迫下对于叶绿素含量有重要贡献;且低氮胁迫下,叶绿素含量还受基因间上位效应的影响。氮素正常供应时有1个位点(位于2B染色体上)、低氮胁迫下有2个位点(位于3A和3B染色体上)同时影响小麦干物质产量和叶绿素含量,而且此3个位点的效应都来自亲本W7984。这一发现表明,小麦干物质产量和叶绿素含量之间存在着内在的联系。 相似文献