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General Recommendations (general + recommendation)
Selected AbstractsAssessment of European streams with diatoms, macrophytes, macroinvertebrates and fish: a comparative metric-based analysis of organism response to stressFRESHWATER BIOLOGY, Issue 9 2006DANIEL HERING Summary 1. Periphytic diatoms, macrophytes, benthic macroinvertebrates and fish were sampled with standard methods in 185 streams in nine European countries to compare their response to degradation. Streams were classified into two main stream type groups (i.e. lowland, mountain streams); in addition, the lowland streams were grouped into four more specific stream types. 2. Principal components analysis with altogether 43 environmental parameters was used to construct complex stressor gradients for physical,chemical, hydromorphological and land use data. About 30 metrics were calculated for each sample and organism group. Metric responses to different stress types were analysed by Spearman Rank Correlation. 3. All four organism groups showed significant response to eutrophication/organic pollution gradients. Generally, diatom metrics were most strongly correlated to eutrophication gradients (85% and 89% of the diatom metrics tested correlated significantly in mountain and lowland streams, respectively), followed by invertebrate metrics (91% and 59%). 4. Responses of the four organism groups to other gradients were less strong; all organism groups responded to varying degrees to land use changes, hydromorphological degradation on the microhabitat scale and general degradation gradients, while the response to hydromorphological gradients on the reach scale was mainly limited to benthic macroinvertebrates (50% and 44% of the metrics tested correlated significantly in mountain and lowland streams, respectively) and fish (29% and 47%). 5. Fish and macrophyte metrics generally showed a poor response to degradation gradients in mountain streams and a strong response in lowland streams. 6. General recommendations on European bioassessment of streams were derived from the results. [source] The potential of current high-resolution imaging-based particle size distribution measurements for crystallization monitoringAICHE JOURNAL, Issue 4 2009P. A. Larsen Abstract High-speed, in situ video microscopy is a promising technology for measuring critical solid-phase properties in suspension crystallization processes. This paper demonstrates the feasibility of high-resolution, video-imaging-based particle size distribution (PSD) measurement by applying image analysis and statistical estimation tools to images from a simulated batch crystallization of an industrial photochemical. The results also demonstrate the ability to monitor important quality parameters, such as the ratio of nuclei mass to seed mass, that cannot be monitored by conventional technologies. General recommendations are given for achieving appropriate sampling conditions to enable effective imaging-based PSD measurement. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source] Health-promoting physical activity of adults with mental retardationDEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 1 2006Heidi I. Stanish Abstract This literature review describes the physical activity behavior of adults with mental retardation consistent with the U.S. Surgeon General's recommendation of 30 minutes of moderate intensity physical activity on 5 or more days per week. The proportion of participants achieving this criterion ranges from 17.5 to 33%. These data are likely to be generous estimates of activity as individuals included in physical activity studies to date have been relatively young and healthy volunteers with mild to moderate limitations. Major sources of physical activity were walking and cycling for transport, chores and work, dancing, and Special Olympics. There is a pressing need to conduct studies using appropriately powered representative samples and to validate measures that assess physical activity less directly; including methodologies in which proxy respondents are used. Accurate information about existing patterns of behavior will enhance the development of effective strategies to promote physical activity among persons with mental retardation. MRDD Research Reviews 2006;12:13,21. © 2006 Wiley-Liss, Inc. [source] Dual stacking of unbuffered saline samples, transient isotachophoresis plus induced pH junction focusingELECTROPHORESIS, Issue 10 2003Sang-Hee Shim Abstract A dual stacking mechanism based on transient isotachophoresis (TITP) and induced pH junction focusing is demonstrated as a means to increase the concentration sensitivity in capillary electrophoresis of highly saline samples. When stacking was carried out with an unbuffered saline sample of fluorescein between two zones of low mobility background electrolyte at high pH under an electric field of reverse polarity, two transient peaks at both boundaries of the sample zone were observed. One peak at the rear boundary could be inferred as a transient isotachophoretic stacked zone. Through computer simulations of an unbuffered sample with a high concentration of sodium chloride, we showed that the fast moving zones of sodium and chloride ions induced pH changes at both boundaries to satisfy the electroneutrality condition and that the peak at the front boundary was due to the induced pH junction. To verify the pH changes, an indicator, thymol blue, was added to an NaCl solution and the color changes under an electric field were observed. The proposed mechanism was supported by observing the dual stacking procedure for an unbuffered sample of 4-nitrophenol and measuring additional sensitivity enhancements by dual stacking for ten weakly acidic compounds. For the ten analytes including nucleoside phosphates, every dual stacking of an unbuffered sample exhibited an additional enhancement up to 86% larger than that of usual transient isotachophoresis of the corresponding buffered sample without loss of separation efficiency and reproducibility. Therefore, it would be useful to skip over buffering in sample preparation for TITP, contrary to the general recommendation. [source] Treatment of chronic hepatitis E in liver transplant recipients with pegylated interferon alpha-2bLIVER TRANSPLANTATION, Issue 4 2010Elizabeth B. Haagsma Hepatitis E virus (HEV) infections are known to run a self-limiting course. Recently, chronic hepatitis E has been described in immunosuppressed patients after solid-organ transplantation. Besides the general recommendation to lower the immunosuppressive medication in these patients, there is currently no specific treatment. We here describe the successful use of pegylated interferon alpha-2b in the treatment of 2 liver transplant recipients who suffered a chronic HEV infection for 9 years (case A) or 9 months (case B). After 4 weeks of therapy, a 2-log decrease (case A) and a 3-log decrease (case B) in the viral load were observed. In case A, who received treatment for 1 year, serum viral RNA became undetectable from week 20 onward, and serum liver enzymes normalized completely. In case B, interferon was discontinued at week 16 because of a lack of a further decline in the viral load. However, 4 weeks after the cessation of therapy, viral RNA was no longer detectable in the serum, and this was probably related to a further decline in the immunosuppressive medication. Liver tests normalized completely. In both cases, no relapse has been noted so far. We conclude that pegylated interferon alpha-2b may be useful in the treatment of chronic HEV infections in patients in whom the reduction of the immunosuppressive medication alone is not sufficient. Liver Transpl , 2010. © 2010 AASLD. [source] A Transdisciplinary Approach to Conservation Land AcquisitionCONSERVATION BIOLOGY, Issue 6 2002Brian Czech I integrated principles of conservation biology, ecological economics, and political science to outline an approach to conservation land acquisition in the United States. American political economy, especially, has profound implications for conservation land acquisition, yet these implications have been largely neglected by public land conservation agencies. I derived three general recommendations for the conservation of biodiversity via land acquisition: (1) relatively inexpensive lands in relatively intact ecosystems should be prioritized for acquisition, (2) fee-title acquisition should be favored over easement acquisition, and (3) low-lying coastal properties should receive lower priority. These recommendations contribute to an ecologically macroeconomic approach to conservation land acquisition, and each will become more appropriate as the sizes of the U.S. and global economies increase. Ultimately, however, the conservation of biodiversity will require a new political economy predicated on sustainability rather than growth. Resumen: La adquisición de tierras es uno de los aspectos claves para la conservación de la biodiversidad y es una empresa transdisciplinaria que requiere de la consideración de fenómenos sociales y naturales. Integré los principios de la biología de la conservación, la economía ecológica y las ciencias políticas para desarrollar una metodología de adquisición de tierras para la conservación en los Estados Unidos. La economía política norteamericana, especialmente tiene implicancias profundas sobre la adquisición de tierras para la conservación, sin embargo, estas aplicaciones han sido negadas ampliamente por las agencias de conservación de tierras públicas. Derivé tres recomendaciones generales para la conservación de la biodiversidad mediante la adquisición de tierras: 1) tierras relativamente baratas en ecosistemas relativamente intactos deben ser priorizadas para la adquisición, 2) los títulos de adquisición honoraria deben ser favorecidos sobre las adquisiciones forzadas y 3) las propiedades costeras bajas deberán recibir la prioridad más baja. Estas recomendaciones contribuyen a una aproximación ecológicamente macroeconómica para la adquisición de tierras para la conservación y cada una de ellas será más apropiada en tanto que los bienes de los Estados Unidos y la economía global incremente. Sin embargo, a fin de cuentas, la conservación de la biodiversidad requerirá de una nueva economía política predicada en la sustentabilidad más que en el crecimiento. [source] On quantitative measures of indirect interactionsECOLOGY LETTERS, Issue 4 2007Toshinori Okuyama Abstract Indirect effects, whether density-mediated (DMII) or trait-mediated (TMII), have been recognized as potentially important drivers of community dynamics. However, empirical studies that have attempted to detect TMII or to quantify the relative strength of DMII and TMII in short-term studies have used a range of different metrics. We review these studies and assess both the consistency of a variety of different metrics and their robustness to (or ability to detect) ecological phenomena such as the dependence of forager behaviour on conspecific density. Quantifying indirect effects over longer time scales when behaviour and population density vary is more challenging, but also necessary if we really intend to incorporate indirect effects into predictions of long-term community dynamics; we discuss some problems associated with this effort and conclude with general recommendations for quantifying indirect effects. [source] SHAPE ANALYSIS OF SYMMETRIC STRUCTURES: QUANTIFYING VARIATION AMONG INDIVIDUALS AND ASYMMETRYEVOLUTION, Issue 10 2002Christian Peter Klingenberg Abstract., Morphometric studies often consider parts with internal left-right symmetry, for instance, the vertebrate skull. This type of symmetry is called object symmetry and is distinguished from matching symmetry, in which two separate structures exist as mirror images of each other, one on each body side. We explain a method for partitioning the total shape variation of landmark configurations with object symmetry into components of symmetric variation among individuals and asymmetry. This method is based on the Procrustes superimposition of the original and a reflected copy of each landmark configuration and is compatible with the two-factor ANOVA model customary in studies of fluctuating asymmetry. We show a fully multivariate framework for testing the effects in the two-factor model with MANOVA statistics, which also applies to shapes with matching symmetry. We apply the new methods in a small case study of pharyngeal jaws of the Neotropical cichlid fish Amphilophus citrinellus. The analysis revealed that the symmetric component of variation in the pharyngeal jaws is dominated by the contrast between two alternative trophic morphs in this species and that there is subtle but statistically significant directional asymmetry. Finally, we provide some general recommendations for morphometric studies of symmetric shapes. [source] A hitchhiker's guide to behavioral analysis in laboratory rodentsGENES, BRAIN AND BEHAVIOR, Issue 2006N. Sousa Genes and environment are both essential and interdependent determinants of behavioral responses. Behavioral genetics focuses on the role of genes on behavior. In this article, we aim to provide a succinct, but comprehensive, overview of the different means through which behavioral analysis may be performed in rodents. We give general recommendations for planning and performing behavioral experiments in rats and mice, followed by brief descriptions of experimental paradigms most commonly used for the analysis of reflexes, sensory function, motor function and exploratory, social, emotional and cognitive behavior. We end with a discussion of some of the shortcomings of current concepts of genetic determinism and argue that the genetic basis of behavior should be analyzed in the context of environmental factors. [source] The transversus abdominis plane block: a valuable option for postoperative analgesia?ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 5 2010A topical review The transversus abdominis plane (TAP) block is a newly described peripheral block involving the nerves of the anterior abdominal wall. The block has been developed for post-operative pain control after gynaecologic and abdominal surgery. The initial technique described the lumbar triangle of Petit as the landmark used to access the TAP in order to facilitate the deposition of local anaesthetic solution in the neurovascular plane. Other techniques include ultrasound-guided access to the neurovascular plane via the mid-axillary line between the iliac crest and the costal margin, and a subcostal access termed the ,oblique subcostal' access. A systematic search of the literature identified a total of seven randomized clinical trials investigating the effect of TAP block on post-operative pain, including a total of 364 patients, of whom 180 received TAP blockade. The surgical procedures included large bowel resection with a midline abdominal incision, caesarean delivery via the Pfannenstiel incision, abdominal hysterectomy via a transverse lower abdominal wall incision, open appendectomy and laparoscopic cholecystectomy. Overall, the results are encouraging and most studies have demonstrated clinically significant reductions of post-operative opioid requirements and pain, as well as some effects on opioid-related side effects (sedation and post-operative nausea and vomiting). Further studies are warranted to support the findings of the primary published trials and to establish general recommendations for the use of a TAP block. [source] The joint effects of larval density and 14C-cypermethrin on the life history and population growth rate of the midge Chironomus ripariusJOURNAL OF APPLIED ECOLOGY, Issue 6 2003Helen L. Hooper Summary 1Chemical effects on organisms are typically assessed using individual-level endpoints or sometimes population growth rate (PGR), but such measurements are generally made at low population densities. In contrast most natural populations are subject to density dependence and fluctuate around the environmental carrying capacity as a result of individual competition for resources. As ecotoxicology aims to make reliable population projections of chemical impacts in the field, an understanding of how high-density or resource-limited populations respond to environmental chemicals is essential. 2Our objective was to determine the joint effects of population density and chemical stress on the life history and PGR of an important ecotoxicological indicator species, Chironomus riparius, under controlled laboratory conditions. Populations were fed the same ration but initiated at different densities and exposed to a solvent control and three concentrations of 14C-cypermethrin in a sediment,water test system for 67 days at 20 ± 1 °C. 3Density had a negative effect on all the measured life-history traits, and PGR declined with increasing density in the controls. Exposure to 14C-cypermethrin had a direct negative effect on juvenile survival, presumably within the first 24 h because the chemical rapidly dissipated from the water column. Reductions in the initial larval densities resulted in an increase in the available resources for the survivors. Subsequently, exposed populations emerged sooner and started producing offspring earlier than the controls. 14C-cypermethrin had no effect on estimated fecundity and adult body weight but interacted with density to reduce the time to first emergence and first reproduction. As a result, PGR increased with cypermethrin concentration when populations were initiated at high densities. 4Synthesis and applications. The results showed that the effects of 14C-cypermethrin were buffered at high density, so that the joint effects of density and chemical stress on PGR were less than additive. Low levels of chemical stressors may increase carrying capacity by reducing juvenile competition for resources. More and perhaps fitter adults may be produced, similar to the effects of predators and culling; however, toxicant exposure may result in survivors that are less tolerant to changing conditions. If less than additive effects are typical in the field, standard regulatory tests carried out at low density may overestimate the effects of environmental chemicals. Further studies over a wide range of chemical stressors and organisms with contrasting life histories are needed to make general recommendations. [source] Glucocorticoids for peri-operative analgesia: how far are we from general recommendations?ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 9 2007H. Kehlet No abstract is available for this article. [source] Mentoring in a Post-Affirmative Action WorldJOURNAL OF SOCIAL ISSUES, Issue 3 2005Jean E. Girves Mentoring can be an effective strategy in improving retention of college students and faculty from fields where historical underrepresentation has occurred. This article reviews the benefits of mentoring in higher education, and identifies components of effective mentoring strategies that promote educational and career advancement. It illustrates how effective programs can be institutionalized and scaled through consortial and national collaborations. Traditional and alternative mentoring models are described through four successful programs designed to increase the academic and professional success of undergraduates, graduate students, and junior faculty. The article concludes with a set of general recommendations and caveats gleaned from the literature and programs reviewed. [source] De novo malignancies following liver transplantation: Impact and recommendationsLIVER TRANSPLANTATION, Issue S2 2009J. Ignacio Herrero Key Points 1. De novo malignancy is one of the leading causes of late mortality after liver transplantation. 2. The risks of skin cancers and lymphoma are more than 10-fold greater than the risks in an age-matched and sex-matched general population. 3. Some types of neoplasia, such as lung, head and neck, and colorectal cancer, are more frequent in liver transplant recipients than in an age-matched and sex-matched population. The risks of other frequent malignancies, such as prostate and breast cancer, do not seem to be increased. 4. The most important risks for posttransplant malignancy are Epstein-Barr virus seronegativity (for lymphoma), sun exposure (for skin cancer), smoking, and increasing age. 5. Despite the absence of evidence, general recommendations (such as avoidance of overimmunosuppression, sunlight protection, and cessation of smoking) should be given. Screening protocols may help to detect neoplasia at an early stage of disease. Liver Transpl 15:S90,S94, 2009. © 2009 AASLD. [source] Protection from phototoxic injury during surgery and endoscopy in erythropoietic protoporphyriaLIVER TRANSPLANTATION, Issue 9 2008Staffan Wahlin Erythropoietic protoporphyria is an inherited condition characterized by pronounced solar photosensitivity and in a minority of patients severe liver disease that necessitates liver transplantation for survival. Phototoxic injury to abdominal organs and skin has been reported in several cases of liver transplantation surgery, including a few transplants in which protective light filters were used. This study discusses the optimal characteristics of light filters used during liver transplantation surgery. An experimental model is used to evaluate the relative protection of different filters, and the results are compared with theoretical calculations regarding the risk for phototoxic injury from light sources in health-care procedures. Whether protective measures are warranted in other illuminated procedures besides liver transplantation has been discussed often but never studied. This study elucidates the risk for phototoxic injury in endoscopy, laparoscopy, and non,liver transplant surgery. A theoretical model and epidemiological data are considered. Our findings indicate that endoscopy, laparoscopy, and surgical procedures other than liver transplantation are safe in the noncholestatic protoporphyria patient and that general recommendations for using filters in these situations are not warranted. Among the tested filters, a flexible yellow filter omitting wavelengths below 470 nm is recommended for liver transplant surgery. This filter has been readily accepted by surgeons and offers a good balance between protection and altered visual color perception. The experimental model, using hemolysis of protoporphyrin-loaded erythrocytes as a measure of phototoxicity, has substantiated theoretical findings on relative filter protection. Liver Transpl 14:1340,1346, 2008. © 2008 AASLD. [source] A primer on classical test theory and item response theory for assessments in medical educationMEDICAL EDUCATION, Issue 1 2010André F De Champlain Context, A test score is a number which purportedly reflects a candidate's proficiency in some clearly defined knowledge or skill domain. A test theory model is necessary to help us better understand the relationship that exists between the observed (or actual) score on an examination and the underlying proficiency in the domain, which is generally unobserved. Common test theory models include classical test theory (CTT) and item response theory (IRT). The widespread use of IRT models over the past several decades attests to their importance in the development and analysis of assessments in medical education. Item response theory models are used for a host of purposes, including item analysis, test form assembly and equating. Although helpful in many circumstances, IRT models make fairly strong assumptions and are mathematically much more complex than CTT models. Consequently, there are instances in which it might be more appropriate to use CTT, especially when common assumptions of IRT cannot be readily met, or in more local settings, such as those that may characterise many medical school examinations. Objectives, The objective of this paper is to provide an overview of both CTT and IRT to the practitioner involved in the development and scoring of medical education assessments. Methods, The tenets of CCT and IRT are initially described. Then, main uses of both models in test development and psychometric activities are illustrated via several practical examples. Finally, general recommendations pertaining to the use of each model in practice are outlined. Discussion, Classical test theory and IRT are widely used to address measurement-related issues that arise from commonly used assessments in medical education, including multiple-choice examinations, objective structured clinical examinations, ward ratings and workplace evaluations. The present paper provides an introduction to these models and how they can be applied to answer common assessment questions. Medical Education 2010: 44: 109,117 [source] Pharmacokinetics, safety, and efficacy of mycophenolate mofetil in combination with sirolimus or ciclosporin in renal transplant patientsBRITISH JOURNAL OF CLINICAL PHARMACOLOGY, Issue 6 2007Mark D. Pescovitz Aims To compare the pharmacokinetics of mycophenolic acid (MPA) and its metabolite (MPAG) when mycophenolate mofetil (MMF) is administered in combination with sirolimus or ciclosporin (CsA) in renal allograft recipients. Safety and efficacy (biopsy-proven acute rejection (BPAR)) were also assessed. Methods Patients (n = 45) were randomized 2 : 1 to receive treatment with sirolimus (n = 30; dosed to maintain trough concentrations of 10,25 ng ml,1 until week 8, and then 8,15 ng ml,1 thereafter) or CsA (n = 15; administered as per centre practice) both in combination with daclizumab, oral MMF and corticosteroids. Pharmacokinetic assessments were performed at day 7, week 4, and months 3 and 6 post-transplant. The primary endpoint was the AUC(0,12 h) for MPA and MPAG. The pharmacokinetics of sirolimus were also assessed. Results MPA exposure was 39,50% lower (month 6 mean AUC(0,12 h) (95%CI): 40.4 (33.8, 47.0) vs. 68.5 (54.9, 82.0) µg ml,1 h) and MPAG exposure was 25,52% higher (722 (607, 838) vs. 485 (402, 569) µg ml,1 h at month 6) in the presence of CsA compared with sirolimus across visits. BPAR was 40.0% with sirolimus and 13.3% with CsA. The incidence of hypertension, tremors and hirsutism was higher with CsA than with sirolimus, while the incidence of diarrhoea, hyperlipidaemia and impaired wound closure was higher with sirolimus. No deaths, malignancies or graft losses were reported. Conclusions Co-administration of sirolimus with MMF led to greater MPA exposure, but lower MPAG exposure, than co-administration with CsA. As rejection rates were higher in the absence of CsA, further study of calcineurin inhibitor-free regimens is required before general recommendations can be made. [source] | |||||||||||||