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Great Concern (great + concern)
Selected AbstractsCoagulation tests in differential diagnosisINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 2000M. Sahud Bleeding disorders pose a special problem for the practising physician haematologist or laboratory coagulation specialist. Great concern is placed on specimen integrity, either during handling or in storage. Heparin contamination, activated specimens and factor VIII lability are common issues. [source] Surge in treatment admissions related to methamphetamine use in Cape Town, South Africa: implications for public healthDRUG AND ALCOHOL REVIEW, Issue 2 2008ANDREAS PLÜDDEMANN Abstract Introduction and Aims. In the past decade, methamphetamine has become increasingly a drug of concern globally. The purpose of this study is to describe the changing trends in treatment admissions for methamphetamine abuse in Cape Town, South Africa and to highlight the implications of these changes for policy, practice and research. Design and Methods. Data were collected on admissions for drug abuse treatment through a regular monitoring system involving drug treatment centres and programmes in Cape Town every 6 months as part of the South African Community Epidemiology Network on Drug Use (SACENDU). A one-page form was completed by treatment centre personnel to obtain demographic data, the patients' primary and secondary substances of abuse, the mode, frequency and age of first use of substance and information on prior treatment. Results. The results indicate that between 2004 and 2006 a dramatic increase in treatment admissions for methamphetamine abuse occurred, a large proportion of the methamphetamine patients are adolescents and that the drug is almost exclusively smoked. Discussion and Conclusions. The rapid increase in admissions for methamphetamine abuse is of great concern, particularly as the drug has a number of serious, often chronic, side effects and that a large proportion of the patients are adolescents. The implications for public health are discussed. [source] Isolation and characterization of naphthalene-degrading bacteria from sediments of Cadiz area (SW Spain)ENVIRONMENTAL TOXICOLOGY, Issue 5 2008D. Nair Abstract Petroleum hydrocarbon contamination of harbor sediments from shipping activity, fuel oil spills, and runoffs are becoming a great concern because of the toxicity and recalcitrance of many of the fuel components. Polycyclic aromatic hydrocarbons (PAHs) are of most concern due to their toxicity, low volatility, resistance to degradation, and high affinity for sediments. Microorganisms, especially bacteria, play an important role in the biodegradation of these hydrocarbons. The objective of the present study was to characterize and isolate PAH-(naphthalene) degrading bacteria in the coastal sediments of Cadiz (SW Spain), since this area is mostly polluted by PAH occurrence. A total of 16 naphthalene-utilizing bacteria were isolated from these sites. Introduction of bacteria isolated from contaminated sediments into mineral medium contributed to the increased rate of hydrocarbon utilization. The bacterial isolates obtained from these sites are very potent in utilizing naphthalene and crude oil. It would be interesting to assess if the selected naphthalene-degrading isolates may degrade other compounds of similar structure. Hence these isolates could be very helpful in bioremediating the PAH-contaminated sites. Further pursue on this work might represent eco-friendly solution for oil contamination on sea surface and coastal area. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008. [source] International conference on the healthy effect of virgin olive oilEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 7 2005Summary 1Ageing represents a great concern in developed countries because the number of people involved and the pathologies related with it, like atherosclerosis, morbus Parkinson, Alzheime's disease, vascular dementia, cognitive decline, diabetes and cancer. 2Epidemiological studies suggest that a Mediterranean diet (which is rich in virgin olive oil) decreases the risk of cardiovascular disease. 3The Mediterranean diet, rich in virgin olive oil, improves the major risk factors for cardiovascular disease, such as the lipoprotein profile, blood pressure, glucose metabolism and antithrombotic profile. Endothelial function, inflammation and oxidative stress are also positively modulated. Some of these effects are attributed to minor components of virgin olive oil. Therefore, the definition of the Mediterranean diet should include virgin olive oil. 4Different observational studies conducted in humans have shown that the intake of monounsaturated fat may be protective against age-related cognitive decline and Alzheimer's disease. 5Microconstituents from virgin olive oil are bioavailable in humans and have shown antioxidant properties and capacity to improve endothelial function. Furthermore they are also able to modify the haemostasis, showing antithrombotic properties. 6In countries where the populations fulfilled a typical Mediterranean diet, such as Spain, Greece and Italy, where virgin olive oil is the principal source of fat, cancer incidence rates are lower than in northern European countries. 7The protective effect of virgin olive oil can be most important in the first decades of life, which suggests that the dietetic benefit of virgin olive oil intake should be initiated before puberty, and maintained through life. 8The more recent studies consistently support that the Mediterranean diet, based in virgin olive oil, is compatible with a healthier ageing and increased longevity. However, despite the significant advances of the recent years, the final proof about the specific mechanisms and contributing role of the different components of virgin olive oil to its beneficial effects requires further investigations. [source] Microbial biodegradation of polyaromatic hydrocarbonsFEMS MICROBIOLOGY REVIEWS, Issue 6 2008Ri-He Peng Abstract Polycyclic aromatic hydrocarbons (PAHs) are widespread in various ecosystems and are pollutants of great concern due to their potential toxicity, mutagenicity and carcinogenicity. Because of their hydrophobic nature, most PAHs bind to particulates in soil and sediments, rendering them less available for biological uptake. Microbial degradation represents the major mechanism responsible for the ecological recovery of PAH-contaminated sites. The goal of this review is to provide an outline of the current knowledge of microbial PAH catabolism. In the past decade, the genetic regulation of the pathway involved in naphthalene degradation by different gram-negative and gram-positive bacteria was studied in great detail. Based on both genomic and proteomic data, a deeper understanding of some high-molecular-weight PAH degradation pathways in bacteria was provided. The ability of nonligninolytic and ligninolytic fungi to transform or metabolize PAH pollutants has received considerable attention, and the biochemical principles underlying the degradation of PAHs were examined. In addition, this review summarizes the information known about the biochemical processes that determine the fate of the individual components of PAH mixtures in polluted ecosystems. A deeper understanding of the microorganism-mediated mechanisms of catalysis of PAHs will facilitate the development of new methods to enhance the bioremediation of PAH-contaminated sites. [source] Time to include time to death?HEALTH ECONOMICS, Issue 4 2004The future of health care expenditure predictions Abstract Government projections of future health care expenditures , a great concern given the aging baby-boom generation , are based on econometric regressions that control explicitly for age but do not control for end-of-life expenditures. Because expenditures increase dramatically on average at the end of life, predictions of future cost distributions based on regressions that omit time to death as an explanatory variable will be biased upward (or, more explicitly, the coefficients on age will be biased upward) if technology or other social factors continue to prolong life. Although health care expenditure predictions for a current sample will not be biased, predictions for future cohorts with greater longevity will be biased upwards, and the magnitude of the bias will increase as the expected longevity increases. We explore the empirical implications of incorporating time to death in longitudinal models of health expenditures for the purpose of predicting future expenditures. Predictions from a simple model that excludes time to death and uses current life tables are 9% higher than from an expanded model controlling for time to death. The bias increases to 15% when using projected life tables for 2020. The predicted differences between the models are sufficient to justify reassessment of the value of inclusion of time to death in models for predicting health care expenditures. Copyright © 2003 John Wiley & Sons, Ltd. [source] P-wave transmission across fractures with nonlinear deformational behaviourINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 11 2006X. B. Zhao Abstract Stress wave attenuation across fractured rock masses is a great concern of underground structure safety. When the wave amplitude is large, fractures experience nonlinear deformation during the wave propagation. This paper presents a study on normal transmission of P-wave across parallel fractures with nonlinear deformational behaviour (static Barton,Bandis model). The results show that the magnitude of transmission coefficient is a function of incident wave amplitude, nondimensional fracture spacing and number of fractures. Two important indices of nondimensional fracture spacing are identified, and they divide the area of nondimensional fracture spacing into three parts (individual fracture area, transition area and small spacing area). In the different areas, the magnitude of transmission coefficient has different trends with nondimensional fracture spacing and number of fractures. In addition, the study reveals that under some circumstances, the magnitude of transmission coefficient increases with increasing number of fractures, and is larger than 1. Copyright © 2006 John Wiley & Sons, Ltd. [source] Audit Quality, Corporate Governance, and Earnings Management: A Meta-AnalysisINTERNATIONAL JOURNAL OF AUDITING, Issue 1 2010Jerry W. Lin Earnings management is of great concern to corporate stakeholders. While numerous studies have investigated the effects of various corporate governance and audit quality variables on earnings management, empirical evidence is rather inconsistent. This meta-analysis identifies 12 significant relationships by integrating results from 48 prior studies. For corporate governance, the independence of the board of directors and its expertise have a negative relationship with earnings management. Similar negative relationships exist between earnings management and the audit committee's independence, its size, expertise, and the number of meetings. The audit committee's share ownership has a positive effect on earnings management. For audit quality, auditor tenure, auditor size, and specialization have a negative relationship with earnings management. Auditor independence, as measured by fee ratio and total fee, is also a deterrent to earnings management. [source] The Ratios of Carbon, Nitrogen, and Phosphorus in a Wetland Coastal Ecosystem of Southern IndiaINTERNATIONAL REVIEW OF HYDROBIOLOGY, Issue 2 2003Lizen Mathews Abstract The fertility of the coastal and estuarine waters is of great concern because of its influence on the productivity of these waters. Seasonal variations in the distribution of organic carbon, total nitrogen and total phosphorus in the sediments of Kuttanad Waters, a part of the tropical Cochin Estuary on the south west coast of India, are examined to identify the contribution of sediments to the fertility of the aquatic systems. The adjoining region has considerable agricultural activity. The fresh water zones had higher quantities of silt and clay whereas the estuarine zone was more sandy. Organic carbon, total phosphorus and total nitrogen were higher in the fresh water zones and lower in the estuarine zones. Total phosphorus and organic carbon showed the lowest values during monsoon periods. No significant trends were observed in the seasonal distributions of total nitrogen. Ratios of C/N, C/P and N/P, and the phosphorus and nitrogen content indicate significant modification in the character of the organic matter. Substantial amounts of the organic matter can contribute to reducing conditions and modify diagenetic processes. [source] Impact of impregnation chemical on surface glossiness of synthetic, acrylic, polyurethane, and water-based varnishesJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008Hakan Keskin Abstract This study was performed to determine the effects of impregnation chemical on surface glossiness of some varnishes. For this purpose, the test samples prepared from Oriental beech, European oak, Scotch pine, Oriental spruce, and Uludag fir woods according to ASTM D 358 were impregnated with Imersol-Aqua according to ASTM D 1413 and producer's definition by short-term (S), medium-term (M), and long-term (L) of dipping methods and coated by synthetic (Sv), acrylic (Ac), water-based (Wb), and polyurethane (Pu) varnishes according to ASTM D 3023. After the varnishing process, the surface glossiness parallel to fibers was determined according to TS 4318. Consequently, among the nonimpregnated wood samples, surface glossiness parallel to fibers was found to be the highest in Oriental spruce and the lowest in European oak. As for the period of dipping, the highest surface glossiness was obtained in medium-term dipping and the lowest in long-term dipping. As for the varnish types, the surface glossiness was found to be the highest in polyurathane varnish and the lowest in water-based varnish. Considering the interaction of wood type, period of impregnation, and type of varnish, surface glossiness was the highest in Uludag fir, long-term dipping, and polyurathane varnish (103.9 gloss) and the lowest in Oriental beech, long-term dipping, and water-based varnish (67.78 gloss). In consequence, in the massive constructions and furniture elements the surface glossiness parallel to fibers after the impregnation with Imersol-Aqua is of great concern, long-term impregnation of Uludag fir materials could be recommended. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] A Follow-up of Deinstitutionalized Men with Intellectual Disabilities and Histories of Antisocial BehaviourJOURNAL OF APPLIED RESEARCH IN INTELLECTUAL DISABILITIES, Issue 4 2004Vernon L. Quinsey Background, There is frequently great concern about the dangerousness of deinstitutionalized men with intellectual disabilities who have been institutionalized because they are considered to be at high risk for the commission of serious antisocial acts or sexual offending. Unfortunately, there is little information on whether changes in the behaviour of these men can be used to adjust supervision so as to manage risk. Methods, An appraisal of men with intellectual disabilities and histories of serious antisocial behaviours who were residing in institutions about to be closed led to a 16 month follow-up of 58 of these clients who had been transferred to community settings. Results, A total of 67% exhibited antisocial behaviour of some kind and 47% exhibited ,hands-on' violent or sexual misbehaviours directed toward other clients or staff. The Violent Risk Appraisal Guide was the best predictor of new violent or sexual incidents and a variety of other pre-release predictors were related to the likelihood of antisocial incidents of any kind. Overall predictive accuracy was moderate. A field trial showed that monthly staff ratings of client characteristics were related to antisocial incidents. Conclusions, These preliminary data indicate that measures of dynamic risk involving staff ratings are worth developing and evaluating. [source] Examining the characteristics of workplace violence in one non-tertiary hospitalJOURNAL OF CLINICAL NURSING, Issue 3-4 2010Rose Chapman Aim., This study sought to determine the prevalence and characteristics of workplace violence directed at a volunteer sample of nurses at one non-tertiary hospital. Respondents' reasons for not reporting these incidents were also investigated. Background., Incidents of workplace violence are increasing worldwide. However, no studies have investigated this phenomenon from the perspective of nurses in Western Australian non-tertiary hospitals. Design., Survey. Method., A survey was distributed to all 332 nurses working in several areas of one non-tertiary hospital in Western Australia to determine their experiences of workplace violence over a 12 month period. Findings., Of the 113 nurses who agreed to participate in this study, 75% reported experiencing workplace violence in the previous twelve months. When asked about their most recent incident, 50% of the nurses said they had reported it verbally, mostly to more senior staff. Only 16% of the nurses completed an official incident report. Reasons for not reporting included the view that WPV is just part of the job and the perception that management would not be responsive. Conclusion., This study showed that for this sample of nurses violent events are occurring at a rate that is similar to those reported in other studies. This finding should be of great concern to the organisation and the community in general. Relevance to clinical practice., Organisations are obliged to improve the safety of the workplace environment for both staff and patients. The findings of our study may be of help to healthcare institutions in developing education programmes for nurses, patients and their friends and relatives to reduce the impact and frequency of workplace violence. [source] Experimental study of the differential effects of playing versus watching violent video games on children's aggressive behaviorAGGRESSIVE BEHAVIOR, Issue 3 2008Hanneke Polman Abstract There is great concern about the effects of playing violent video games on aggressive behavior. The present experimental study was aimed at investigating the differential effects of actively playing vs. passively watching the same violent video game on subsequent aggressive behavior. Fifty-seven children aged 10,13 either played a violent video game (active violent condition), watched the same violent video game (passive violent condition), or played a non-violent video game (active non-violent condition). Aggression was measured through peer nominations of real-life aggressive incidents during a free play session at school. After the active participation of actually playing the violent video game, boys behaved more aggressively than did the boys in the passive game condition. For girls, game condition was not related to aggression. These findings indicate that, specifically for boys, playing a violent video game should lead to more aggression than watching television violence. Aggr. Behav. 34:256,264, 2008. © 2007 Wiley-Liss, Inc. [source] Extrapolating in vitro metabolic interactions to isolated perfused liver: Predictions of metabolic interactions between R -bufuralol, bunitrolol, and debrisoquineJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 10 2010Sami Haddad Abstract Drug,drug interactions (DDIs) are a great concern to the selection of new drug candidates. While in vitro screening assays for DDI are a routine procedure in preclinical research, their interpretation and relevance for the in vivo situation still represent a major challenge. The objective of the present study was to develop a novel mechanistic modeling approach to quantitatively predict DDI solely based upon in vitro data. The overall strategy consisted of developing a model of the liver with physiological details on three subcompartments: the sinusoidal space, the space of Disse, and the cellular matrix. The substrate and inhibitor concentrations available to the metabolizing enzyme were modeled with respect to time and were used to relate the in vitro inhibition constant (Ki) to the in vivo situation. The development of the liver model was supported by experimental studies in a stepwise fashion: (i) characterizing the interactions between the three selected drugs (R -bufuralol (BUF), bunitrolol (BUN), and debrisoquine (DBQ)) in microsomal incubations, (ii) modeling DDI based on binary mixtures model for all the possible pairs of interactions (BUF,BUN, BUF,DBQ, BUN,DBQ) describing a mutual competitive inhibition between the compounds, (iii) incorporating in the binary mixtures model the related constants determined in vitro for the inhibition, metabolism, transport, and partition coefficients of each compound, and (iv) validating the overall liver model for the prediction of the perfusate kinetics of each drug determined in isolated perfused rat liver (IPRL) for the single and paired compounds. Results from microsomal coincubations showed that competitive inhibition was the mechanism of interactions between all three compounds, as expected since those compounds are all substrates of rat CYP2D2. For each drug, the Ki values estimated were similar to their Km values for CYP2D2 indicative of a competition for the same substrate-binding site. Comparison of the performance between the novel liver physiologically based pharmacokinetic (PBPK) model and published empirical models in simulating the perfusate concentration,time profile was based on the area under the curve (AUC) and the shape of the curve of the perfusate time course. The present liver PBPK model was able to quantitatively predict the metabolic interactions determined during the perfusions of mixtures of BUF,DBQ and BUN,DBQ. However, a lower degree of accuracy was obtained for the mixtures of BUF,BUN, potentially due to some interindividual variability in the relative proportion of CYP2D1 and CYP2D2 isoenzymes, both involved in BUF metabolism. Overall, in this metabolic interaction prediction exercise, the PBPK model clearly showed to be the best predictor of perfusate kinetics compared to more empirical models. The present study demonstrated the potential of the mechanistic liver model to enable predictions of metabolic DDI under in vivo condition solely from in vitro information. © 2010 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99:4406,4426, 2010 [source] Proteomic Analysis Demonstrates Adolescent Vulnerability to Lasting Hippocampal Changes Following Chronic Alcohol ConsumptionALCOHOLISM, Issue 1 2009Garth A. Hargreaves Background:, Excessive teenage alcohol consumption is of great concern because alcohol may adversely alter the developmental trajectory of the brain. The aim of the present study was to assess whether chronic intermittent alcohol intake during the adolescent period alters hippocampal protein expression to a greater extent than during adulthood. Methods:, Adolescent [postnatal day (PND) 27] and adult (PND 55) male Wistar rats were given 8 hours daily access to beer (4.44% ethanol v/v) in addition to ad libitum food and water for 4 weeks. From a large subject pool, subgroups of adolescent and adult rats were selected that displayed equivalent alcohol intake (average of 6.1 g/kg/day ethanol). The 4 weeks of alcohol access were followed by a 2-week alcohol-free washout period after which the hippocampus was analyzed using 2-DE proteomics. Results:, Beer consumption by the adult group resulted in modest hippocampal changes relative to alcohol naïve adult controls. The only changes observed were an up-regulation of citrate synthase (a precursor to the Krebs cycle) and fatty acid binding protein (which facilitates fatty acid metabolism). In contrast, adolescent rats consuming alcohol showed more widespread hippocampal changes relative to adolescent controls. These included an increase in cytoskeletal protein T-complex protein 1 subunit epsilon (TCP-1) and a decrease in the expression of 10 other proteins, including glyceraldehyde-3-phosphate dehydrogenase (GAPDH), triose phosphate isomerise, alpha-enolase, and phosphoglycerate kinase 1 (all involved in glycolysis); glutamate dehydrogenase 1 (an important regulator of glutamate); methylmalonate-semialdehyde dehydrogenase (involved in aldehyde detoxification); ubiquitin carboxyl-terminal hydrolase isozyme L1 (a regulator of protein degradation); and synapsin 2 (involved in synaptogenesis and neurotransmitter release). Conclusions:, These results suggest the adolescent hippocampus is more vulnerable to lasting proteomic changes following repeated alcohol exposure. The proteins most affected include those related to glycolysis, glutamate metabolism, neurodegeneration, synaptic function, and cytoskeletal structure. [source] SENSORY AND INSTRUMENTAL TEXTURE MEASUREMENT OF THERMALLY PROCESSED RICEJOURNAL OF SENSORY STUDIES, Issue 5 2005M. PRAKASH ABSTRACT Rice is the staple food of many countries and its sensory quality is of great concern to the consumers. Its preservation through thermal processing in retort pouches for ready-to-eat purposes was carried out by different time,temperature schedules with and without oil to achieve a minimum Foof 3 min. The sensory analysis of the cooked rice carried out using quantitative descriptive analysis showed that a process schedule of 118C, 8 min was optimum to have the optimal sensory characteristics. The same rice samples were subjected to instrumental texture measurements by texture analyzer using a crosshead speed of 0.5 mm/s with 90% compression for hardness and stickiness parameters. The instrumental hardness showed high correlation with sensory hardness, chewiness and overall quality (r = 0.72; r = 0.73; r = 0.79) and a negative correlation with sensory stickiness (r = ,0.75). Applying principal component analysis, thermally processed rice samples were further classified based on the sensory and instrumental texture attributes. [source] Role of mineral nutrition in minimizing cadmium accumulation by plantsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 6 2010Nadeem Sarwar Abstract Cadmium (Cd) is a highly toxic heavy metal for both plants and animals. The presence of Cd in agricultural soils is of great concern regarding its entry into the food chain. Cadmium enters into the soil,plant environment mainly through anthropogenic activities. Compounds of Cd are more soluble than other heavy metals, so it is more available and readily taken up by plants and accumulates in different edible plant parts through which it enters the food chain. A number of approaches are being used to minimize the entry of Cd into the food chain. Proper plant nutrition is one of the good strategies to alleviate the damaging effects of Cd on plants and to avoid its entry into the food chain. Plant nutrients play a very important role in developing plant tolerance to Cd toxicity and thus, low Cd accumulation in different plant parts. In this report, the role of some macronutrients (nitrogen, phosphorus, sulfur and calcium), micronutrients (zinc, iron and manganese), and silicon (a beneficial nutrient) has been discussed in detail as to how these nutrients play their role in decreasing Cd uptake and accumulation in crop plants. Copyright © 2010 Society of Chemical Industry [source] Nursing migration: global treasure hunt or disaster-in-the-making?NURSING INQUIRY, Issue 4 2001Mireille Kingma Nursing migration: global treasure hunt or disaster-in-the-making? International nurse migration , moving from one country to another in the search of employment , is the focus of this article. The majority of member states of the World Health Organization report a shortage, maldistribution and misutilisation of nurses. International recruitment has been seen as a solution. The negative effects of international migration on the ,supplier' countries may be recognised today but are not effectively addressed. Nurse migration is motivated by the search for professional development, better quality of life and personal safety. Pay and learning opportunities continue to be the most frequently reported incentives for nurse migration, especially by nurses from less-developed countries. Career opportunities were considered key incentives for nurses emigrating from high-income countries. Language was reported to be a significant barrier. The positive global economic/social/professional development resulting from international migration needs to be weighed against a substantial ,brain and skills drain' experienced by supplier countries. The vulnerable status of migrant nurses is also of concern in certain cases. The focus on short-term solutions as opposed to resolving the problem of a worldwide shortage of nurses causes great concern. Recent initiatives attempt to curb or channel international recruitment. The delicate balance between recognising the right of individual nurses to migrate and a collective concern for the health of a nation's population must be achieved. [source] Computational chemistry study of the environmentally important acid-catalyzed hydrolysis of atrazine and related 2-chloro- s -triazinesPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 8 2002Phillip Sawunyama Abstract Many chlorine-containing pesticides, for example 2-chloro- s -triazines, are of great concern both environmentally and toxicologically. As a result, ascertaining or predicting the fate and transport of these compounds in soils and water is of current interest. Transformation pathways for 2-chloro- s -triazines in the environment include dealkylation, dechlorination (hydrolysis), and ring cleavage. This study explored the feasibility of using computational chemistry, specifically the hybrid density functional theory method, B3LYP, to predict hydrolysis trends of atrazine (2-chloro- N4 -ethyl- N6 -isopropyl-1,3,5-triazine-2,4-diamine) and related 2-chloro- s -triazines to the corresponding 2-hydroxy- s -triazines. Gas-phase energetics are described on the basis of calculations performed at the B3LYP/6-311++G(d,p)//B3LYP/6-31G* level of theory. Calculated free energies of hydrolysis (,hG298) are nearly the same for simazine (2-chloro- N4,N6 -diethyl-1,3,5-triazine-2,4-diamine), atrazine, and propazine (2-chloro- N4,N6 -di-isopropyl-1,3,5-triazine-2,4-diamine), suggesting that hydrolysis is not significantly affected by the side-chain amine-nitrogen alkyl substituents. High-energy barriers also suggest that the reactions are not likely to be observed in the gas phase. Aqueous solvation effects were examined by means of self-consistent reaction field methods (SCRF). Molecular structures were optimized at the B3LYP/6-31G* level using the Onsager model, and solvation energies were calculated at the B3LYP/6-311++G(d,p) level using the isodensity surface polarizable continuum model (IPCM). Although the extent of solvent stabilization was greater for cationic species than neutral ones, the full extent of solvation is underestimated, especially for the transition state structures. As a consequence, the calculated hydrolysis barrier for protonated atrazine is exaggerated compared with the experimentally determined one. Overall, the hydrolysis reactions follow a concerted nucleophilic aromatic substitution (SNAr) pathway. Published in 2002 for SCI by John Wiley & Sons, Ltd [source] Diagnostic evaluation of developmental delay/mental retardation: An overviewAMERICAN JOURNAL OF MEDICAL GENETICS, Issue 1 2003Agatino Battaglia Abstract Mental retardation (MR) is one of the few clinically important disorders for which the etiopathogenesis is still poorly understood. It is a condition of great concern for public health and society. MR is currently defined as a significant impairment of cognitive and adaptive functions, with onset before age 18 years. It may become evident during infancy or early childhood as developmental delay (DD), but it is best diagnosed during the school years. MR is estimated to occur in 1,10% of the population, and research on its etiology has always been a challenge in medicine. The etiopathogenesis encompasses so many different entities that the attending physician can sometimes feel a "virtual panic," starting a wide-range diagnostic evaluation. The Consensus Conference of the American College of Medical Genetics has recently established guidelines regarding the evaluation of patients with MR [Curry et al., 1997], emphasizing the high diagnostic utility of cytogenetic studies and neuroimaging in certain clinical settings. However, since then there has been substantial progress in molecular cytogenetics and neuroimaging techniques, the use of which has allowed recognition and definition of new disorders, thus increasing the diagnostic yield. This review will focus on the most appropriate investigations shown to be, at present, necessary to define the etiology of DD/MR, in the context of recommendations for the clinical evaluation of the patient with undiagnosed MR. © 2003 Wiley-Liss, Inc. [source] Response of Native and Exotic Grasses to Increased Soil Nitrogen and Recovery in a Postfire EnvironmentRESTORATION ECOLOGY, Issue 4 2006Molly E. Hunter Abstract Native plant recovery following wildfires is of great concern to managers because of the potential for increased water run-off and soil erosion associated with severely burned areas. Although postfire seeding with exotic grasses or cultivars of native grasses (seeded grasses) may mitigate the potential for increased run-off and erosion, such treatments may also be detrimental to long-term recovery of other native plant species. The degree to which seeded grasses dominate a site and reduce native plant diversity may be a function of the availability of resources such as nitrogen and light and differing abilities of native and seeded grasses to utilize available resources. We tested the hypothesis that seeded grasses have higher growth rates than native grasses when nitrogen and light availability is high in a greenhouse experiment. To determine how differing resource utilization strategies may affect distribution of native and seeded grasses across a burned landscape, we conducted botanical surveys after a wildfire in northern New Mexico, U.S.A., one and four years after the fire. In the greenhouse study we found seeded grasses to produce significantly more biomass than native grasses when nitrogen and light availability was high. Seeded grasses increased in cover from 1,4 years after the fire only in areas where total soil nitrogen was higher. Increased cover of seeded grasses did not affect recovery of native grasses, but it did lead to reduced native species richness at small scales. The potential negative long-term consequences of seeding with exotic grasses should be considered in postfire rehabilitation treatments. [source] Annotation: Paediatric HIV InfectionTHE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 4 2001Rebekah Lwin HIV and AIDS have made a huge global impact, permeating the social, cultural, and economic fabric of almost all nations. The first cases of HIV infection in children were reported in the late 1980s and numbers have since risen steadily throughout the world, with some of the poorest and least developed countries experiencing the highest prevalence. Combined drug regimes have changed the course of HIV-related illness and brought increased survival to those for whom treatment is available. With this, however, have come fresh concerns relating to drug resistance, treatment adherence, and the risk of second-generation vertical transmission as HIV-infected children now survive into adulthood and beyond. The psychological literature has addressed issues such as the direct effect of HIV on child development, social and cultural attitudes, family functioning and support, affected children and orphans of HIV-infected parents, sexual health education, disclosure of diagnosis, and long-term clinical management. The outcome for those living in wealthier countries is optimistic, but the spread of this virus in the rest of the world and its impact on family life and social and political systems remains of great concern. [source] Phonation threshold pressure predictions using viscoelastic properties up to 1,400 Hz of injectables intended for Reinke's space,THE LARYNGOSCOPE, Issue 5 2010Sarah A. Klemuk PhD Abstract Objectives/Hypothesis: Viscoelastic properties of numerous vocal fold injectables have been reported but not at speaking frequencies. For materials intended for Reinke's space, ramifications of property values are of great concern because of their impact on ease of voice onset. Our objectives were: 1) to measure viscoelastic properties of a new nonresorbing carbomer and well-known vocal fold injectables at vocalization frequencies using established and new instrumentation, and 2) to predict phonation threshold pressures using a computer model with intended placement in Reinke's space. Study Design: Rheology and phonation threshold pressure calculations. Methods: Injectables were evaluated with a traditional rotational rheometer and a new piezo-rotary vibrator. Using these data at vocalization frequencies, phonation threshold pressures (PTP) were calculated for each biomaterial, assuming a low dimensional model with supraglottic coupling and adjusted vocal fold length and thickness at each frequency. Results were normalized to a nominal PTP value. Results: Viscoelastic data were acquired at vocalization frequencies as high as 363 to 1,400 Hz for six new carbomer hydrogels, Hylan B, and Extracel intended for vocal fold Reinke's space injection and for Cymetra (lateral injection). Reliability was confirmed with good data overlap when measuring with either rheometer. PTP predictions ranged from 0.001 to 16 times the nominal PTP value of 0.283 kPa. Conclusions: Accurate viscoelastic measurements of vocal fold injectables are now possible at physiologic frequencies. Hylan B, Extracel, and the new carbomer hydrogels should generate easy vocal onset and sustainable vocalization based on their rheologic properties if injected into Reinke's space. Applications may vary depending on desired longevity of implant. Laryngoscope, 2010 [source] Accuracy verification of spaceborne radar estimates of rain rateATMOSPHERIC SCIENCE LETTERS, Issue 1 2005E. Amitai Abstract The distribution of rain rate is of great concern for many hydrological applications. Probability distribution functions (pdf) of rain rate can now be obtained from spaceborne radar observations. Effort to evaluate these pdfs using ground observations is described. Copyright © 2005 Royal Meteorological Society [source] Epidemiology of alcohol-related burden of disease among Indigenous AustraliansAUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH, Issue 2010Bianca Calabria Abstract Objective: To compare the burden of alcohol-related harm and underlying factors of this harm, by age and sex, for Indigenous and general population Australians. Methods: Population attributable fractions are used to estimate the disability adjusted life years (DALYs) for alcohol-related disease and injury. The DALYs were converted to rates per 1,000 by age and sex for the Indigenous and general populations. Results: Homicide and violence rates were much higher for Indigenous males: greatest population difference was for 30,44 years, Indigenous rate 8.9 times higher. Rates of suicide were also greater: the largest population difference was for 15,29 years, Indigenous rate 3.9 times higher. Similarly, for Indigenous females, homicide and violence rates were much higher: greatest population difference was for 30,44 years, Indigenous rate 18.1 times higher. Rates of suicide were also greater: the largest population difference was for 15,29 years, Indigenous rate 5.0 times higher. Conclusions: Alcohol consumption and associated harms are of great concern for Indigenous Australians across all ages. Violent alcohol-related harms have been highlighted as a major concern. Implications: To reduce the disproportionate burden of alcohol-related harm experienced by Indigenous Australians, targeted interventions should include the impact on families and communities and not just the individual. [source] Industrial and agricultural pollution: a threat to the health of children living in the Arctic regionACTA PAEDIATRICA, Issue 11 2003R ZetterströmArticle first published online: 2 JAN 200 Various environmental pollutants of industrial or agricultural origin such as persistent organic pollutants (POCs) are causing great concern owing to their toxicity to humans and animals. At the Stockholm Convention on POCs in 2001, 12 of these pollutants, i.e. dioxins, PCBs (polychlorinated biphenyls) and DDT were referred to as "the dirty dozen". Conclusion: Collaborative studies by scientists from Canada, Russia, Scandinavia and other countries representing different fields such as environmental chemistry, ecology and medical sciences may increase our knowledge about the present threat of toxic chemicals to ecology and human health in the Arctic region. It is hoped that improved understanding will promote preventive political decisions. [source] Scalping of Flavors in Packaged FoodsCOMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, Issue 1 2007M.G. Sajilata ABSTRACT:, Food packaging, although an integral part of the food chain, has a major drawback in that, often, the packaging material interacts with the flavor constituents of the food, causing either a selective or an extensive loss of desirable food flavors or absorption of undesirable off-flavors from the packaging material, thereby resulting in an eventual loss of quality of the packaged food item. The process is called "scalping" and is of great concern to the food industry, which is always looking out for new avenues in "packaging solutions" for its final product quality needs. The review highlights the various attributes of the scalping process, explores approaches to the reduction of the manifested undesirable effects, and covers other relevant aspects. [source] Cloning Adult Farm Animals: A Review of the Possibilities and Problems Associated with Somatic Cell Nuclear TransferAMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 2 2003J. L. Edwards In 1997, Wilmut et al. announced the birth of Dolly, the first ever clone of an adult animal. To date, adult sheep, goats, cattle, mice, pigs, cats and rabbits have been cloned using somatic cell nuclear transfer. The ultimate challenge of cloning procedures is to reprogram the somatic cell nucleus for development of the early embryo. The cell type of choice for reprogramming the somatic nucleus is an enucleated oocyte. Given that somatic cells are easily obtained from adult animals, cultured in the laboratory and then genetically modified, cloning procedures are ideal for introducing specific genetic modifications in farm animals. Genetic modification of farm animals provides a means of studying genes involved in a variety of biological systems and disease processes. Moreover, genetically modified farm animals have created a new form of ,pharming' whereby farm animals serve as bioreactors for production of pharmaceuticals or organ donors. A major limitation of cloning procedures is the extreme inefficiency for producing live offspring. Dolly was the only live offspring produced after 277 attempts. Similar inefficiencies for cloning adult animals of other species have been described by others. Many factors related to cloning procedures and culture environment contribute to the death of clones, both in the embryonic and fetal periods as well as during neonatal life. Extreme inefficiencies of this magnitude, along with the fact that death of the surrogate may occur, continue to raise great concerns with cloning humans. [source] | |||||||||||||||||||||||||