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Extensive Evaluation (extensive + evaluation)
Selected AbstractsRiver restoration, habitat heterogeneity and biodiversity: a failure of theory or practice?FRESHWATER BIOLOGY, Issue 2010MARGARET A. PALMER Summary 1. Stream ecosystems are increasingly impacted by multiple stressors that lead to a loss of sensitive species and an overall reduction in diversity. A dominant paradigm in ecological restoration is that increasing habitat heterogeneity (HH) promotes restoration of biodiversity. This paradigm is reflected in stream restoration projects through the common practice of re-configuring channels to add meanders and adding physical structures such as boulders and artificial riffles to restore biodiversity by enhancing structural heterogeneity. 2. To evaluate the validity of this paradigm, we completed an extensive evaluation of published studies that have quantitatively examined the reach-scale response of invertebrate species richness to restoration actions that increased channel complexity/HH. We also evaluated studies that used manipulative or correlative approaches to test for a relationship between physical heterogeneity and invertebrate diversity in streams that were not in need of restoration. 3. We found habitat and macroinvertebrate data for 78 independent stream or river restoration projects described by 18 different author groups in which invertebrate taxa richness data in response to the restoration treatment were available. Most projects were successful in enhancing physical HH; however, only two showed statistically significant increases in biodiversity rendering them more similar to reference reaches or sites. 4. Studies manipulating structural complexity in otherwise healthy streams were generally small in scale and less than half showed a significant positive relationship with invertebrate diversity. Only one-third of the studies that attempted to correlate biodiversity to existing levels of in-stream heterogeneity found a positive relationship. 5. Across all the studies we evaluated, there is no evidence that HH was the primary factor controlling stream invertebrate diversity, particularly in a restoration context. The findings indicate that physical heterogeneity should not be the driving force in selecting restoration approaches for most degraded waterways. Evidence suggests that much more must be done to restore streams impacted by multiple stressors than simply re-configuring channels and enhancing structural complexity with meanders, boulders, wood, or other structures. 6. Thematic implications: as integrators of all activities on the land, streams are sensitive to a host of stressors including impacts from urbanisation, agriculture, deforestation, invasive species, flow regulation, water extractions and mining. The impacts of these individually or in combination typically lead to a decrease in biodiversity because of reduced water quality, biologically unsuitable flow regimes, dispersal barriers, altered inputs of organic matter or sunlight, degraded habitat, etc. Despite the complexity of these stressors, a large number of stream restoration projects focus primarily on physical channel characteristics. We show that this is not a wise investment if ecological recovery is the goal. Managers should critically diagnose the stressors impacting an impaired stream and invest resources first in repairing those problems most likely to limit restoration. [source] Can panel data really improve the predictability of the monetary exchange rate model?JOURNAL OF FORECASTING, Issue 5 2007Joakim Westerlund Abstract A common explanation for the inability of the monetary model to beat the random walk in forecasting future exchange rates is that conventional time series tests may have low power, and that panel data should generate more powerful tests. This paper provides an extensive evaluation of this power argument to the use of panel data in the forecasting context. In particular, by using simulations it is shown that although pooling of the individual prediction tests can lead to substantial power gains, pooling only the parameters of the forecasting equation, as has been suggested in the previous literature, does not seem to generate more powerful tests. The simulation results are illustrated through an empirical application. Copyright © 2007 John Wiley & Sons, Ltd. [source] Rating of CCl4 -induced rat liver fibrosis by blood serum glycomicsJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 7 2007Liesbeth Desmyter Abstract Background:, Non-invasive staging of human liver fibrosis is a desirable objective that remains under extensive evaluation. Animal model systems are often used for studying human liver disease and screening antifibrotic compounds. The aim of the present study was to investigate the potential use of serum N-glycan profiles to evaluate liver fibrosis in a rat model. Methods:, Liver fibrosis and cirrhosis were induced in rats by oral administration of CCl4. Liver injury was assessed biochemically (alanine aminotransferase [ALT] activity, aspartate aminotransferase [AST] activity and total bilirubin) and histologically. The N-glycan profile (GlycoTest) was performed using DNA sequencer-assisted,fluorophore-assisted carbohydrate electrophoresis technology. In parallel, the effect of cotreatment with antifibrotic interferon-, (IFN-,) was studied. Results:, The biopsy scoring system showed that CCl4 induced early fibrosis (F < 1,2) in rats after 3 weeks of treatment, and cirrhosis (F4) after 12 weeks. Significant increases in ALT activity, AST activity and total bilirubin levels were detected only after 12 weeks of CCl4 treatment. GlycoTest showed three glycans were significantly altered in the CCl4 -goup. Peak 3 started at week 6, at an early stage in fibrosis development (F < 1,2), whereas peaks 4 and 5 occurred at week 9, at which time mild liver fibrosis (F = 1,2) had developed. The changes in the CCl4 -IFN-, group were intermediate between the CCl4 - and the control groups. Conclusion:, The GlycoTest is much more sensitive than biochemical tests for evaluating liver fibrosis/cirrhosis in the rat model. The test can also be used as a non-invasive marker for screening and monitoring the antifibrotic activity of potential therapeutic compounds. [source] Recommendations for assessing Patient-Reported Outcomes and Health-Related quality of life in clinical trials on allergy: a GA2LEN taskforce position paperALLERGY, Issue 3 2010I. Baiardini To cite this article: Baiardini I, Bousquet PJ, Brzoza Z, Canonica GW, Compalati E, Fiocchi A, Fokkens W, van Wijk RG, La Grutta S, Lombardi C, Maurer M, Pinto AM, Ridolo E, Senna GE, Terreehorst I, Todo Bom A, Bousquet J, Zuberbier T, Braido F. Recommendations for assessing Patient-Reported Outcomes and Health-Related quality of life in clinical trials on allergy: a GA2LEN taskforce position paper. Allergy 2010; 65: 290,295. Abstract The aim of this Global Allergy and Asthma European Network (GA2LEN) consensus report is to provide recommendations for patient-reported outcomes (PROs) evaluation in clinical trials for allergic diseases, which constitute a global health problem in terms of physical, psychological economic and social impact. During the last 40 years, PROs have gained large consideration and use in the scientific community, to gain a better understanding of patients' subjective assessment with respect to elements concerning their health condition. They include all health-related reports coming from the patient, without involvement or interpretation by physician or others. PROs assessment should be performed by validated tools (disease-specific tools when available or generic ones) selected taking into account the aim of the study, the expected intervention effects and the determinant and confounding factors or patient-related factors which could influence PROs. Moreover, each tool should be used exclusively in the patient population following the authors' indications without modification and performing a cross-cultural validation if the tool must be used in a language that differs from the original. The result analysis also suggests that the relevance of PROs results in any interventional study should include a pre,post assessment providing information concerning statistical differences within or among groups, rates of response for the PROs and a minimal important difference for the population. The report underlines the importance of further investigation on some topics, such as the quality assessment of existing PROs tools, the definition of inclusion and exclusion criteria and a more extensive evaluation of the correlation between PROs, besides health-related quality of life, and clinical data. [source] Idiopathic colitis following cardiac transplantation: Three pediatric casesPEDIATRIC TRANSPLANTATION, Issue 6 2003Ghassan Wahbeh Abstract:, Colitis can cause significant morbidity in pediatric solid organ transplant recipients. In many cases, despite intensive evaluation, a specific infectious, inflammatory, or immunologic etiology is not identified, and idiopathic colitis may be the ultimate diagnosis. We defined idiopathic colitis as the presence of gastrointestinal symptoms (vomiting, diarrhea, abdominal pain) with inflammatory changes seen on intestinal biopsy in the absence of identifiable bowel disease. We describe three cases of idiopathic colitis following cardiac transplantation. In each case, the post-transplant course was complicated by persistent abdominal pain, diarrhea, and in two cases, vomiting. All three patients' post-transplant courses were marked by multiple graft rejection episodes, and all received intensified immune therapy in addition to usual maintenance immunosuppression. Differential diagnosis of the patients' gastrointestinal symptoms included drug side effect, indolent opportunistic infections, inflammatory bowel disease, post-transplant lymphoproliferative disease, and microvascular ischemic colitis. Continued symptoms led these patients to extensive evaluation including imaging studies, endoscopy and tissue biopsy, and stool, blood and tissue cultures for viral, bacterial and parasitic pathogens. Definitive differentiation presented significant diagnostic challenge, and once identifiable etiologies were excluded, the diagnosis of idiopathic colitis was assigned. We conclude that idiopathic colitis following pediatric cardiac transplantation can be a cause of significant morbidity. Endoscopic evaluation of patients who present with gastrointestinal symptoms after transplant is warranted to identify the presence of idiopathic colitis once common causes are ruled out. Further study is needed to identify its incidence, etiology, therapeutic options and prognosis. [source] Evaluation of a rapid diagnostic field test kit for identification of Phytophthora species, including P. ramorum and P. kernoviae at the point of inspectionPLANT PATHOLOGY, Issue 5 2007C. R. Lane Plant health regulations to prevent the introduction and spread of Phytophthora ramorum and P. kernoviae require rapid, cost effective diagnostic methods for screening large numbers of plant samples at the time of inspection. Current on-site techniques require expensive equipment, considerable expertise and are not suited for plant health inspectors. Therefore, an extensive evaluation of a commercially available lateral flow device (LFD) for Phytophthora species was performed involving four separate trials and 634 samples. The assay proved simple to use, provided results in a few minutes and on every occasion a control line reacted positively confirming the validity of the test. LFD results were compared with those from testing a parallel sample, using laboratory methods (isolation and real-time PCR). The diagnostic sensitivity of the LFD (87·6%) compared favourably with the standard laboratory methods although the diagnostic specificity was not as stringent (82·9%). There were a small number (n = 28) of false negatives, but for statutory purposes where all positive samples must be identified to species level by laboratory testing, overall efficiency was 95·6% as compared with visual assessment of symptoms of between 20-30% for P. ramorum and P. kernoviae. This work demonstrates the value of the LFD for diagnosing Phytophthora species at the time of inspection and as a useful primary screen for selecting samples for laboratory testing to determine the species identification. [source] Comparison of ADHD symptom subtypes as source-specific syndromesTHE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 6 2004Kenneth D. Gadow Background:, This study examines differences between the three subtypes of attention-deficit/hyperactivity disorder (ADHD), inattentive (I), hyperactive-impulsive (H), and combined (C), in a heterogeneous sample of 248 boys (ages 6 to 10 years) with emotional and behavioral problems who were recruited for participation in a diagnostic study. Method:, The boys and their mothers participated in an extensive evaluation that involved multiple assessments of cognitive, behavioral, academic, and family functioning. ADHD subtypes were defined on the basis of teacher alone, mother alone, and mother/teacher ratings of DSM-IV symptoms. Results:, Results indicated ADHD symptom groups showed a differential pattern of impairment socially (H,C>I) and cognitively (I,C>H). The C and H groups were the most and least impaired overall, respectively, and all subtypes were differentiated from the nonADHD clinical control or NONE (N) group in a manner consistent with the primary findings. External validation of group differences was limited, and there were marked inconsistencies in the pattern of findings depending on how groups were defined. For the most part, although the mother/teacher grouping strategy (compared with either alone) captured a greater diversity of differences between subtypes, it also obscured some. Conclusions:, Observed findings are consistent with the notion that mothers and teachers interpret symptom statements in terms of behaviors that are most relevant for their daily concerns. [source] Out-of-sample Hedge Performances for Risk Management in China Commodity Futures Markets,ASIAN ECONOMIC JOURNAL, Issue 3 2009Sang-Kuck Chung C13; C32; G13 We consider a new time-series model that describes long memory and asymmetries simultaneously under the dynamic conditional correlation specification, and that can be used to assess an extensive evaluation of out-of-sample hedging performances using aluminum and fuel oil futures markets traded on the Shanghai Futures Exchange. Upon fitting it to the spot and futures returns of aluminum and fuel oil markets, it is found that a parsimonious version of the model captures the salient features of the data rather well. The empirical results suggest that separating the effects of positive and negative basis on the market volatility, and the correlation between two markets as well as jointly incorporating the long memory effect of the basis on market returns not only provides better descriptions of the dynamic behaviors of commodity prices, but also plays a statistically significant role in determining dynamic hedging strategies. [source] Afebrile benign convulsions with mild gastroenteritis: a new entity?ACTA NEUROLOGICA SCANDINAVICA, Issue 2 2009A. Verrotti Afebrile seizures in children usually necessitate investigations in order to determine the etiology and estimate the prognosis. Recently, convulsions that are described as benign but afebrile have been documented in children, in association with diarrhea, and are now recognized as a distinct entity. Benign afebrile seizures with mild gastroenteritis are defined as convulsions accompanying symptoms of mild diarrhea without dehydration or electrolyte derangement and without fever before and after the seizures in healthy children without meningitis, encephalitis or encephalopathy. The convulsions are short, symmetrical, generalized tonic,clonic seizures, occurring in clusters. Laboratory studies (full blood count, blood glucose, creatinine, serum electrolytes, cerebrospinal fluid, bacterial and viral cultures) are usually normal, and other investigations (neuroimaging and electroencephalogram) are not necessary. Prognosis is always favorable (normal psychomotor development, no recurrences of seizures), and anticonvulsant therapy is not warranted. Recognition of this benign infantile convulsion avoids extensive evaluation and long-term anticonvulsant therapy; physicians may reassure the parents regarding the lack of long-term sequelae. In conclusion, this type of seizure seems to be a new entity, but it awaits a correct place in the large group of infantile convulsion disorders. [source] | ||||||||||||||||