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941.
In groups with multiple males, direct mate competition may select for the evolution of dominance hierarchies that sort males into a queue for access to fertile females. The priority-of-access (PoA) model proposed by Altmann in 1962 makes explicit predictions about the resulting paternity distribution based on an interaction between male dominance rank and the overlap of female receptive phases. Here, we investigated whether the logic of the PoA model predicted the distribution of paternity across ranks in a seasonal breeder with high reproductive synchrony over six consecutive mating seasons. We studied 18 males that resided in a group of wild Assamese macaques (Macaca assamensis) in their natural habitat at Phu Khieo Wildlife Sanctuary, Thailand, between 2006 and 2011 with 5 to 13 conceptions per season. We assessed whether mate guarding increased paternity success, described “short-term” deviations from predicted paternity distribution, and examined how these are related to the number of competitors and fertile females. We determined genetic paternity of 43 (93 %) offspring born into the study group and found reproductive skew to be relatively low with 29 % alpha male paternity in accordance with the high degree of female reproductive synchrony observed. Short-term deviations from expected paternity distribution over ranks were not explained by the number of resident males or the number of conceiving females or their interaction. Within the limits of this study, these results suggest that even if males cannot discern female fertile phases, if reproduction is seasonal, and if reproductive synchrony is high, males may also compete directly over access to females.  相似文献   
942.
We present a new experimental set-up enabling fine-scale examination of how changing environmental conditions affect the below-ground biogeochemical microenvironment of aquatic macrophytes. By means of microsensor and planar optode technology, the influence of plant-mediated radial O2 release on the below-ground chemical microenvironment of Zostera muelleri and Halophila ovalis was determined in high spatio-temporal resolution. The seagrass specimens were cultured in a new split flow chamber with artificial sediment made of a deoxygenated seawater–agar solution with added sulphide. Microelectrode measurements revealed radial O2 release from the root–shoot junction of both Z. muelleri and H. ovalis during both light stimulation and darkness, resulting in a rapid decrease in H2S concentration, and a significant drop in pH was observed within the plant-derived oxic microzone of Z. muelleri. No radial O2 release was detectable from the below-ground tissue of Z. muelleri during conditions of combined water-column hypoxia and darkness, leaving the plants more susceptible to sulphide invasion. The spatial O2 heterogeneity within the immediate rhizosphere of Z. muelleri was furthermore determined in two dimensions by means of planar optodes. O2 images revealed a decrease in the spatial extent of the plant-derived oxic microzone surrounding the below-ground tissue during darkness, supporting the microelectrode measurements. This new experimental approach can be applied to all rooted aquatic plants, as it allows for direct visual assessment of the below-ground tissue surface during microprofiling, while enabling modification of the above-ground environmental conditions.  相似文献   
943.
Over the past few decades, the industry developed an increasing interest in using renewable, bio-based thermosetting polymers as matrix systems for composites and coating systems. In the present paper an acrylated epoxidized linseed oil (AELO) was synthesized from epoxidized linseed oil (ELO) through ring opening of the oxirane group using acrylic acid as the ring opening agent. The synthesized AELO was mixed with three different photoinitiators and cured under monochromatic conditions (???=?365?nm) at different light intensities and at different temperatures. The concentration of the initiators was aligned that all initiators absorb at 365?nm the same amount of light. The evolution of cure was monitored by using real-time infrared spectroscopy with a heated attenuated total reflection unit. The decrease of absorption in the measured spectra at 1,406?cm?1 was used to calculate the conversion of acrylic double bonds with increasing time of UV light exposure to get information about the cure kinetics for each AELO mixture at different light intensities and different temperatures. Wood substrates were coated in a preliminary work with the AELO mixtures and after UV-curing some technological coating properties like gloss, scratch resistance, adhesion, and solvent resistance were tested. In combination with the information about the cure kinetics in the present work the coating properties were correlated with the cure evolution and the final degree of double bond conversion. The found correlation can be used in the future to find optimized coating conditions for the AELO mixtures on wood substrates.  相似文献   
944.
945.
The fatty acid (FA) composition was determined in 14 species of marine macroalgae belonging to the Chlorophyta, Phaeophyta and Rhodophyta, which were collected from ?ile in the Black Sea and Kepez in the Dardanelles. Generally, polyunsaturated FAs and monounsaturated FAs were major components (50–77%). Total saturated FAs ranged from 22% to 50%, with 16?:?0 as the most abundant saturate (32–38%). Two samples of Cystoseira barbata collected from a different station had some differences from each other in their contents of 18?:?2n-6 and 18?:?3n-3 and in the 18?:?2n-6/20?:?4n-6 ratios. Green algal species had a significantly higher proportion of unsaturated FAs and a significantly lower proportion of saturated FAs than the red and brown algae. The amount of n-3 FAs was significantly higher in Ulva rigita, Chaetomorpha linum, Enteromorpha linza and Gracilaria verrucosa (8.88, 6.44, 5.31 and 5.24, respectively).  相似文献   
946.
Adult respiratory distress syndrome (ARDS) is a clinical syndrome which occurs due to various direct or indirect noxious agents and pyhsical mechanisms. One of the etiological factors is ingested chemicals (e.g. paraquat, ethylene glycol). The organophosphorous (OP) insecticides are the most toxic and frequently encountered chemicals that produce poisoning in humans. Studies were undertaken to investigate whether OP insecticides may produce ARDS. Fifteen autopsy cases due to suicidal OP insecticide poisoning were investigated. Toxicological analyses were performed with a gas chromatography-nitrogen phosphorous detector (GC-NPD). Methamidophos, dimefox and dichlorvos were the detected OP. Lungs were examined macroscopically. Two cases showed features compatible with ARDS in which the only cause of death was OP poisoning. Due to the severity of ARDS it is important to assess insecticidal exposure in an attempt to enhance survival patterns following OP poisoning in patients in order to initiate therapy.  相似文献   
947.
Pesticides are chemicals used in agriculture but are known to produce adverse effects on humans. In this study, blood activities of superoxide dismutase (SOD), catalase (CAT), aspartate transaminase (AST), alanine transaminase (ALT), gamma-glutamyl transaminase, lactate dehydrogenase (LDH), and levels of malondialdhyde (MDA) were determined in 44 greenhouse workers (24 tomato workers, 20 clove workers) and in tomato (24 samples) and clove (20 samples) products. At the end of this study, blood MDA levels and activities of ALT, AST, and LDH levels in greenhouse workers were significantly increased while SOD and CAT activity levels fell significantly. Pesticide residues were not found in agricultural worker blood. Malathion residues (average 0.8?ppm) were detected in tomatoes (8 samples) in these greenhouses. Data suggest that the health of the greenhouse workers may be adversely affected by pesticides.  相似文献   
948.
Accumulation of metals by aquatic organisms is mostly affected by other biological components in environments. In this study, cadmium (Cd) accumulation in green algae, Cladophora glomerata (L.) Kutz., exposed to 0.1 and 1.0 mg L?1 of Cd for 15 and 30 days was examined in laboratory conditions in the presence of Nile tilapia Oreochromis niloticus (L.). The green algae C. glomerata accumulated Cd concentrations as 690 ± 70 and 3430 ± 470 mg kg?1 on day 15, and 1130 ± 180 and 6830 ± 1540 mg kg?1 on day 30. There were significant increases (p < 0.05) in metal accumulation by green algae as the exposure time and metal concentration increased. The results also indicated that the presence of Nile tilapia in the medium led to a significant Cd accumulation in the green algae compared to control (p < 0.05).  相似文献   
949.
Voltammetry provides new insights into the effects exerted in vitro by methylation of native DNA. Applying single sweep voltammetry at a stationary mercury electrode the successive steps of the destabilization of alkylated DNA are investigated. The methylation of the nucleic acids is manifested by a specific electrochemical response, due to the 7‐methylguanine, a major product of the methylation of DNA. Short time effects of the methylation include the labilization of 4 to 5 base pairs per methylated guanine base. Furthermore, uncommon protonation properties of the base 7‐methylguanine‐cytosine have been detected. Long term effects of the methylation are ultimately spontaneous hydrolytic strand breaks induced by the prior depurination connected with the release of the 7‐methylguanine from the methylated DNA. A half time t1/2 of 102 h for the depurination at 37°C has been determined. The depurination and the subsequent strand breaks alter the hydrodynamic properties of the damaged DNA, an effect which can be sensitively followed with voltammetry via the resulting changes in the diffusion coefficient of the damaged biopolymer.  相似文献   
950.
The gaschromatographic determination of Toxaphene in the presence of other chlorinated hydrocarbons with similar retention times is often difficult. The practibility of a new method, based on photodehalogenation of the interfering substances, is shown during the analytical determination of Toxaphene residues in selected environmental samples, especially in fish and fish products. Irradiation of the extracts after clean‐up procedures with wavelengths at 254 nm lead directly to photodechlorination products of interfering substances with shorter retention times and makes it possible to determine the Toxaphene components quantitatively, which are mostly stable under the same experimental conditions.  相似文献   
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