733 research outputs found
The Effects of Climate Change on the Ecotoxicology of Contaminants of Emerging Concern: Flame Retardants, Contemporary Use Pesticides and Pharmaceuticals Personal Care Products on the Estuarine Grass Shrimp, \u3cem\u3ePalaemontes pugio\u3c/em\u3e
Global Climate Change may adversely affect the environment, increasing water temperature and altered salinity which may affect the toxicity of both legacy pollutants and Contaminants of Emerging Concern (CECs). Acute, 96 hour toxicity tests with adult grass shrimp (Palaemonetes pugio) assessed the effects of CECs (Polybrominated Diphenyl Esther (PBDE) – 47, ibuprofen, bifenthrin, triclosan, and bifenthrin/triclosan mixtures) under Standard Conditions (20°C, 20psu) and different Climate Change Conditions (30°C, and/or35psu) In addition, the grass shrimp microbiome (e.g. Vibrio bacteria) were assessed following acute triclosan exposures at the Maximum Exposure Concentration (MECs) and Minimum Inhibitory Concentration (MICs) under standard conditions. Colonies of Vibrio parahaemolyticus, V. vulnificus, V. cholerae and total vibrios from controls and triclosan exposed grass shrimp were enumerated and then isolates from each species were then tested for multiple antibiotic resistance. Statistical tests (Probit and Chi Square Analysis) were used to estimate LC50 values and to determine significant (p ≤ 0.05) differences (ANOVA and Dunnetts or nonparametric equivalents) in survival and levels of antibiotic resistance between controls and each CEC tested.
Results indicated that PBDE-47 under increased temperature and salinity conditions was more toxic, with a 96h LC50 of 31.30°C /L compared to 201.48 μg/L under Standard Conditions (30°C & 35 psu). Results for Ibuprofen indicated a 96-h LC50 under Standard Conditions (20°C, 20 psu) of 81.89 mg/L compared to 96-h LC50 ranging from 32.69 mg/ - 61.6 mg /L under different Climate Change Conditions of increased temperature and salinity (30°C; 20 or 35 psu). Bifenthrin under climate change conditions was more toxic with 96-hour LC50 of 96-hour LC50 of 43.74 ng/L compared to 53.47 ng/L under Standard Conditions. The triclosan LC5 under Climate Change Conditions was 325 μg/L compared to an LC50 of 580 μg/L under Standard Conditions. The triclosan and bifenthrin mixtures based upon Climate Change Conditions approached levels that were more than additively toxic (Additive Index = 1.00) with an Additive Index of 0.99 versus 1.32 for the Standard Condition Mixture. Exposure to triclosan MEC reduced Vibrio bacteria levels and both MEC and MIC exposure levels generally increased the antibiotic resistance of several of the 11 antibiotics tested
Effects of sulpher foam and mycorrhizal fungi on Eggplant infested with Nematode(Meloidogyne javanica) at seed or seedling stage
Arbuscular mycorrhizal fungi and sulphur foam added either at direct seeding or at transplanting decreased the effects of nematode (Meloidogyne javanica) on eggplant growth, and improved plant health. Experiments were conducted to study the possible interactions between the Mycorrhizal fungi (Glomus mossae and Gigaspora spp.) and sulphur foam to control M. javanica on eggplant at seed or seedling stage. Experiment at seed stage treated with Mycorrhiza or sulphur foam alone or together stimulated the growth and reduced Nematode infestation significantly. Treated plant at seedling stage increased plant growth and reduced the number of galls /gm of root system. The interaction between Mycorrhiza and sulpher foam treatments was not significant
Agricultural marketing in Iraq: an analysis of the variety of factors and processes underlying the marketing of Iraqi agricultural produce, with emphases on the potential for improving the marketing infrastructure
Agricultural marketing in Iraq has witnessed major changes over the last three decades, and particularly during the 1970's, due to structural and distributional changes in both production and consumption as a consequence of the effect of market forces upon production and an increase in demand. Therefore, agricultural marketing in Iraq is faced with several problems. On the one hand these problems are caused by the continuing increase in demand as a result of the increase in population numbers partly due to natural increase and partly due to (temporary) foreign immigration and the relative increase in per capita income which has improved the purchasing power of the people, all of which have led to a growth in demand ahead of improvements in agricultural production and distribution. On the other hand, are the problems directly related to the physical geographical conditions of Iraq, to the past and present marketing systems and to the locational distribution of the areas of production? All these factors have imposed great pressures on the marketing system, which at the same time that it has become more government- controlled, has also had to come to terms with an increasing percentage of consumers who are entirely dependent upon the system for the supply of their needs, and a diminishing number of producers who need to be encouraged, above all by better price incentives, to be more efficient crop growers and animal raisers. The current system has kept pace with neither the general increase in demand, nor the further demand that most products be available all the year round. Therefore, this study aims to analyse the variety of factors and processes underlying the marketing of Iraqi agricultural produce, with emphasis on the spatial patterns and the potential for improving the infrastructure and managements
Acoustic Factors In Forming Arabic Structure
This paper is a study of the sound factors, which control the mechanism of sound changes, affecting Arabic sounds, when they hold adjacent positions, in certain morphological structural formations. It becomes clear to us, through linguistic patterns and examples in this paper, which are more influential than other adjacent sounds, that those sounds are characterized by certain features which make them dominant in the process of structural formation, most important among them are features of sibilant, velarization, voicedness, plosion, nasalization, being rolled, length of place of articulation, and the vowel characteristics called, in Arabic, (madd and liin). Moreover, it becomes evident that the position of a sound in the linguistics formation, and also the position of the sound in the vocal apparatus, are important factors influencing and being influenced as well as the process of sound production in morphological formations. It is not worthy to mention here that ancient scholars of Arabic, headed by Sibawayh , have noticed and given short comments on some of the above – mentioned factors, but their notes haven’t reached the level of theoretical formulation which we hope this paper will do
VISUAL DESIGN TOOL FOR ELECTROSTATIC LELSES
Current research presents a visual-computational tool to design and investigate round electrostatic lenses in sense of analysis procedure. The finite elements methods is adopted to find the electrostatic potential in the lens region. Laplaces equation is first replaced by a certain functional which physically represent the electric energy stored in the electric field. This functional is then minimized at each mesh point with respect to the nearest eight ones. This minimization process is proved to be entirely equivalent to solving Laplaces equation. The requirement that the functional being minimized is then yields a set of nine point equations which inter relate the potentials at adjacent mesh points. Finally this set of equations is solved to find the electrostatic potential at each mesh point in the region of the lens under consideration. The procedure steps mention above are coded to program written in visual basic. Hence an interface tool for analyzing and designing electrostatic lenses has been built up. Designing results proved that the introduced tools has an excellent outputs in comparison with the others written in not visual programming languages. Furthermore it easier for researchers and designer to use such a tool over their counterpart ones
Self-Regulation Skills and its Relation to Classroom Behavioral Problems Among the Students of Learning Difficulties
This study aimed at identifying the efficiency level of a cognitive-behavioral program in developing the self-regulation skills, and their impact upon the classroom behavioral problems of 5th grade students with learning difficulties available at Amman schools and public and private centers. The sample included (40) male and female students who were randomly divided into 2 groups: a control and experimental with (20) students each. The experimental group was exposed to a training on the cognitive-behavioral program whereas the control group didn't get that training. The cognitive-behavioral program involved (10) sessions, 90 minutes each, through which the participants of the experimental group got cognitive-behavioral practices for developing their self-regulation skills. For the purposes of this study, the scale of self-regulation, which was prepared by Turki (2004),was used, as well as the estimation checklist of classroom behavioral problems prepared by the researcher in order to gather data and compare the 2 groups participants' performance on the pre and post tests. The results of the study indicated that there are statistically significant differences in each of self-regulation skills and classroom behavioral problems between the students of the experimental group who were exposed to the program and the students of the control group who were not exposed to the program for the benefit of the experimental. Besides, the results showed that there is a statistically significant contradictory connection between the acquisition of self-regulation skills and classroom behavioral problems. Key words:Self-Regulation Skills, Behavioral Problems, Learning Difficultie
Conditions that Stabilize Membrane Domains Also Antagonize n-Alcohol Anesthesia
Diverse molecules induce general anesthesia with potency strongly correlated with both their hydrophobicity and their effects on certain ion channels. We recently observed that several n -alcohol anesthetics inhibit heterogeneity in plasma-membrane-derived vesicles by lowering the critical temperature (Tc) for phase separation. Here, we exploit conditions that stabilize membrane heterogeneity to further test the correlation between the anesthetic potency of n -alcohols and effects on Tc. First, we show that hexadecanol acts oppositely to n -alcohol anesthetics on membrane mixing and antagonizes ethanol-induced anesthesia in a tadpole behavioral assay. Second, we show that two previously described “intoxication reversers” raise Tc and counter ethanol’s effects in vesicles, mimicking the findings of previous electrophysiological and behavioral measurements. Third, we find that elevated hydrostatic pressure, long known to reverse anesthesia, also raises Tc in vesicles with a magnitude that counters the effect of butanol at relevant concentrations and pressures. Taken together, these results demonstrate that ΔTc predicts anesthetic potency for n-alcohols better than hydrophobicity in a range of contexts, supporting a mechanistic role for membrane heterogeneity in general anesthesia
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