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991.
Lisa A. Simoncelli Christine J. Delevan Omar Ali S. Al-Naimi Maryam Bamshad 《Behavioral ecology and sociobiology》2010,64(5):865-873
Most monogamous male mammals display parental care, but the mechanism by which they become motivated to care for infants remains
unknown. We used prairie voles (Microtus ochrogaster) as a model of biparental species to test the hypothesis that physical contact with a female enhances male parental responsiveness
before the birth of offspring. We tested four groups of males: mated with physical contact with their mate, mated with only
distal cues from their mate, mated with no cues, and unmated with distal cues from a female. The subjects were placed in an
oversized cage divided into two compartments by a perforated barrier. At mid-gestation, the bedding and females were removed,
and the males’ responses toward two infants were videotaped. Although most males behaved parentally, mated males exposed to
their mate’s tactile or distal cues approached the young faster and were more likely to care for both infants than unmated
males which received female distal cues. Males who had physical contact with their mate showed “kyphosis” (a crouching position
over infants) and contacted infants more frequently than mated males which received no cues from their mate or unmated males
which received female distal cues. Furthermore, the frequency of non-social behaviors was lowest in mated males that had physical
contact with their mate. The data suggest that exposure to female distal cues after mating is sufficient to increase male
parental attentiveness, but female somatosensory cues affect the male's tendency to remain in physical contact with infants. 相似文献
992.
氧气条件对矿化垃圾修复石油污染土壤的影响 总被引:1,自引:0,他引:1
通过对比不同氧气条件下矿化垃圾修复石油污染土壤的效果、降解产物、生态毒性、酶活性和微生物群落,分析了氧气条件对矿化垃圾修复石油污染土壤的影响.结果表明,添加矿化垃圾在厌氧、好氧和厌氧-好氧3种氧气条件下对微生物修复石油污染土壤都有较好的强化效果.修复的最佳氧气条件为好氧,好氧修复后土壤总石油烃(TPH)去除率最高,土壤生态毒性最小.厌氧-好氧试验的TPH去除率和土壤生态毒性介于厌氧和好氧试验之间.好氧条件更利于小分子石油类污染物的降解,修复后链烷烃、烯烃、芳香烃和芳香烃衍生物的去除率最高,新增污染物主要为环烷烃、含卤有机物和含氮杂环有机物.而厌氧条件更利于大分子石油类污染物的降解,修复后环烷烃、环烷烃衍生物和含氮杂环有机物的去除率最高,新增污染物主要为支链烷烃、环烷烃和含氧环状有机物.好氧条件下土壤微生物总活性更高,而厌氧条件下土壤微生物多样性更高.纲水平上,厌氧和好氧条件下土壤优势细菌都为放线菌纲、β-变形菌纲和γ-变形菌纲,优势真菌都为粪壳菌纲.但在属水平上优势菌差异很大,好氧条件下的石油烃降解菌更多,而厌氧条件下的石油烃衍生物降解菌更多. 相似文献
993.
Ara Talat Nisa Waqar-Un Aziz Rukhsanda Rafiq Muhammad Tariq Gill Rafaqat Ali Hayat Malik Tahir Afridi Uzma 《Environmental geochemistry and health》2021,43(9):1-11
Environmental Geochemistry and Health - As the largest organ of the human body, the skin is the major exposure route of NO2. However, the evidence for a relationship between NO2 exposure and... 相似文献
994.
Ali Waqar Aslam Muhammad Wajahat Feng Caiyan Junaid Muhammad Ali Kamran Li Shehong Chen Zhe Yu Ziheng Rasool Atta Zhang Hua 《Environmental geochemistry and health》2019,41(5):2223-2238
Environmental Geochemistry and Health - The current study focuses on the understanding of contamination status, distribution, source apportionment and health perspectives of arsenic (As), uranium... 相似文献
995.
Caspian roach, Rutilus rutilus caspicus, might experience potassium permanganate (PM) toxicity, because it is common and widely used disinfectant in fish rearing and propagation centers in Iran. Thus, acute toxicity (24-h-LC50) of PM was determined on Caspian roach in two size classes (small and large groups), under aerated and non-aerated conditions, using static non-renewal system. 24-h-LC50 for PM in Caspian roach was 3.2, 3, 3.2, and 2.8?mg?L?1 in large-aerated, large-non-aerated, small-aerated, and small-non-aerated groups, respectively. Results indicated that aeration was led to decrease in PM toxicity, regardless of size class. However, large fish showed more tolerance to PM toxicity compared to small ones, under non-aerated condition. It is concluded that aeration could decrease the toxicity of PM that seems to be due to the increase in PM degradation, derived from increase in water turbulence. It is suggested that 96-h-LC50 may be more suitable to determine the effects of fish size on PM toxicity than 24-h-LC50. 相似文献
996.
Mushtaq Ahmed Nadia Latif Rahmat Ali Khan Akhlaq Ahmad Gustavo Thomé Maria R.C. Schetinger 《毒物与环境化学》2013,95(8):1659-1665
The venom of krait (Bungarus sindanus), an Elapidae snake, contains high level of acetylcholinesterase (AChE) activity. The effect of arachidonic acid on krait (Bungarus sindanus) venom AChE (acetylcholine hydrolase, EC 3.1.1.7) was studied using kinetic methods. This study evaluated for the first time whether arachidonic acid acts as potential AChE inhibitor of krait venom. Kinetic studies, using Line-Weaver Burk and Dixon plots, indicated that the inhibition produced by arachidonic acid was non-competitive, i.e., both km and V max fell with increase in the concentration of arachidonic acid. The concentration of arachidonic acid required to inhibit 50% of enzymatic activity was found to be 1.9?µM while the inhibitory constant (Ki ) was 1.4?µM. The present results suggest that essential fatty acid (arachidonic acid) may also be used as an inhibitor of snake venom AChE. 相似文献
997.
Ali Mohammad Latifi Seyed Mohammad Nabavi Morteza Mirzaei Mahmood Tavalaei Hossein Ghafurian Claire Hellio 《毒物与环境化学》2013,95(9):1670-1677
Cesium and mercury are two mono-valent elements which can be found in toxic industrial, medical, and nuclear wastes. Their presence in the environment has deleterious effects on the ecosystem, living organisms including humans. Due to the chemical nature of these metals, bioremediation by conventional methods is more difficult to achieve compared to other metals. In this study, we used three biosorbents (oak powder, gall nut, and bacterial exopolymer) for the bioremediation of Hg and Cs. Bio-polymer was produced in the GMS mineral broth. Synthetic wastes of Hg(NO3)2 and isotope Cs-133 as the single-metal solutions were used. The biorefining process was carried out in glass columns, made of Pyrex, with dimensions 20?×?7/2?cm2 with a V-shaped bottom. The samples were analyzed using atomic absorption. The experimental results showed that eliminated metal percent by oak powder, gall nut, and bacterial exopolymer were, respectively, of 94.8%, 96%, and 13.8% for Hg and 7.8%, 4.4%, and 69.4% for Cs. The tests revealed that Ca++, when used as flocculant, played a key role in both biosorption and bio-precipitation rates. Consequently, it was concluded that the investigated biosorbents could be use as an integrated biosorption system for the refinement of mixed wastes. 相似文献
998.
The technical feasibility of utilization of fly ash as a low-cost adsorbent for the removal of metals from water has been studied. For two types of fly ashes, the retention capacities of copper, lead, and zinc metal ions have been studied. Contact time, initial concentration, and pH have been varied and their effect on retention mechanism has been studied. The dominant mechanisms responsible for retention are found to be precipitation due to the presence of calcium hydroxide, and adsorption due to the presence of silica and alumina oxide surfaces in the fly ash. First-order kinetic plots have revealed that the rate constant increases with increase in the initial concentration and pH. Langmuir adsorption isotherms have been plotted to study the maximum adsorption capacities for metal ions considered under different conditions. X-ray diffraction studies revealed the formation of new peaks corresponding to respective metal ions precipitates under alkaline conditions. 相似文献
999.
The effects of the five herbicides propanil, quinclorac, molinate/propanil, 2,4-D amine, and bensulfuron on Odonata diversity and abundance at the experimental rice plots was investigated. A total of 13 Odonata morphospecies belonging to two families have been identified. Treated plots exhibited higher species richness (up to 12 species) than the control plot (8 species). Ishnura spp. was the most abundant species in the treated plots with a mean density of 194.2 individuals per m2, (ind m?2) followed by Brachythemis contaminata (152 ind m?2) and Agriocnemis spp. (124 ind m?2). In the control plots, Agrocnemis spp. was the dominant species (153 ind m?2) followed by Ishnura spp. (143 ind m?2) and Neurothemis fluctuans (59 ind m?2). In the propanil-treated plot, the highest number of odonate species (10 species) was recorded followed by the plots treated with quinclorax and molinate/propanil (9 species). On the 2,4-D amine or bensulfuron-treated plots as well as the control plot, only eight odonate species were recorded. This study revealed that herbicide application had a positive effect on Odonata diversity. This seems reasonable as Odonata are non-target organisms for herbicides. Furthermore, the decomposed weeds resulting from herbicide application would enrich the water with necessary organic matter. 相似文献
1000.
Protective effects of quercetin against sodium fluoride-induced oxidative stress in rat erythrocytes
Seyed Fazel Nabavi Shahram Eslami Akbar Hajizadeh Moghaddam Naser Jafari Mohammad Ali Ebrahimzadeh 《毒物与环境化学》2013,95(8):1666-1675
Protective effects of quercetin against oxidative stress induced by sodium fluoride intoxication in rat erythrocytes were evaluated. Rats were divided into five groups consisting of 10 in each for this experiment. The animals of group I received water and standard diet to serve as control group, the animals of groups II and III were treated with quercetin (10 and 20?mg?kg?1 body weight), administrated intraperitoneally for 7 days followed by sodium fluoride (600?ppm) in drinking water for the next 7 days. The animals of group IV were treated with vitamin C (10?mg?kg?1) intraperitoneally for 7 days followed by sodium fluoride treatment for next 7 days serving as positive control group. The animals of group V were treated only with sodium fluoride (600?ppm) for the same time and were used as control group. Blood sample were collected via retro-orbital puncture. The antioxidant enzymes, superoxide dismutase, and catalase, as well as the levels of reduced glutathione and lipid peroxidation end products were measured in erythrocytes. There was a significant increase in lipid peroxidation along with a decrease in superoxide dismutase activity in the erythrocytes of sodium fluoride-treated animals. Quercetin treatment prior to fluoride administration normalized the levels of all parameters measured in the rat erythrocytes. 相似文献