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Little Difference (little + difference)
Kinds of Little Difference Selected AbstractsLongitudinal health-related quality of life after mandibular resection for oral cancer: a comparison between rim and segment,HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 1 2004Simon N. Rogers FDS Abstract Background. Mandibular resection for oral cancer is often necessary to achieve an adequate margin of tumor clearance. Segmental mandibulectomy has been associated with a poor health-related quality of life (HRQOL), particularly before composite free tissue transfer to reconstruct the defect. Little is published in the literature contrasting the subjective deficit of segmental compared with rim resection. The aim of this study was to use a validated head and neck HRQOL questionnaire to compare rim and segmental mandibular resection in patients having primary surgery for oral cancer. Method. There were 224 consecutive patients between 1995 and 1999 who were treated by primary surgery for oral squamous cell carcinoma. One hundred twenty-tree had no mandibular resection, 44 had a rim resection, and 57 had a segmental resection. The University of Washington Quality of life questionnaire (UW-QOL) was adminstered before treatment, at 6 months, 12 months and after 18 months. Results. Preoperatively, patients undergoing segmental resection reported significantly more pain, chewing problems, and a lower composite UW-QOL score. Postperatively, the segment group tended to score worse at all time points, particularly in appearance, swallowing, recreation, and chewing; however, the difference between rim and segment was only seen in smaller resections without adjuvant radiotherapy. Little difference was seen between rim or segment for tumors <4 cm with radiotherapy and between rim and segments for tumors >4cm. Conclusion: After segmental mandibulectomy and reconstruction using composite free tissue transfer, the UW-QOL scores were relatively good. The only 2 difference between rim and segments was noted in the small resections without radiotherapy, and some of this was reflected in differences at baseline. © 2004 Wiley Periodicals, Inc. Head Neck26: 54,62, 2004. [source] Risk Factors for Severity and Type of the Hip Fracture,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 5 2009Jane A Cauley Abstract More severe hip fractures such as displaced femoral neck (FN) fractures and unstable intertrochanteric (IT) fractures lead to poorer outcomes, but risk factors for severe fractures have not been studied. To identify risk factors for severe types of hip fracture, we performed a prospective cohort study and obtained preoperative hip radiographs from women who sustained an incident hip fracture (excluding traumatic fractures). A single radiologist scored the severity of FN fractures by the Garden System: grades I and II, undisplaced; grades III and IV, displaced. The severity of IT hip fractures was rated by the Kyle System: grades I and II, stable; grades III and IV, unstable. A total of 249 women had FN fractures: 75 (30%) were undisplaced. A total of 213 women had IT fractures: 59 (28%) were stable. Both types of hip fracture increased with age, but older age was even more strongly associated with more severe hip fractures. Low BMD was more strongly related to undisplaced FN fractures (p interaction BMD × FN type, p = 0.0008) and stable IT fractures (p interaction BMD × IT type, p = 0.04). Similar findings were observed for estimated volumetric BMD and hip geometric parameters. Corticosteroid use was only associated with displaced FN fractures, and Parkinson's disease was only associated with stable IT fractures. Little difference was reported in the self-reported circumstances surrounding each type of fracture. In conclusion, the lower the BMD, the greater the likelihood of experiencing a hip fracture that is less displaced and more stable. [source] Therapist effects in randomised controlled trials: what to do about themJOURNAL OF CLINICAL NURSING, Issue 7-8 2010Stephen J Walters Aims and objectives., The aim of this study is to describe and compare three statistical methods to allow for therapist effects in individually randomised controlled trials. Background., In an individually randomised controlled trial where the intervention is delivered by a health professional it seems likely that the effectiveness of the intervention, independent of any treatment effect, could depend on the skill of the health professional delivering it. This leads to a potential clustering of the outcomes for the patients being treated by the same health professional. Design., Retrospective statistical analysis of outcomes from four example randomised controlled trial datasets with potential clustering by health professional. Methods., Three methods to allow for clustering are described: cluster level analysis; random effects models and marginal models. These models were fitted to continuous outcome data from four example randomised controlled trial datasets with potential clustering by health professional. Results., The cluster level models produced the widest confidence intervals. Little difference was found between the estimates of the regression coefficients for the treatment effect and confidence intervals between the individual patient level models for the datasets. The conclusions reached for each dataset match those published in the original papers. The intracluster correlation coefficient ranged from <0·001,0·04 for the outcomes, which shows only minor levels of clustering within the datasets. Conclusions., The models, which use individual level data are to be preferred. Treatment coefficients from these models have different interpretations. The choice of model should depend on the scientific question being asked. Relevance to clinical practice., We recommend that researchers should be aware of any potential clustering, by health professional, in their randomised controlled trial and use appropriate methods to account for this clustering in the statistical analysis of the data. [source] Comparison of spinal anesthesia with general anesthesia on morphine requirement after abdominal hysterectomyACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 5 2009L. MASSICOTTE Purpose: The aim of this study was to compare morphine consumption with patient-controlled analgesia (PCA) between spinal anesthesia (SA) (bupivacaine, morphine and fentanyl) and general anesthesia (GA) (sufentanil) after an abdominal hysterectomy. Methods: Forty women were randomly assigned to receive SA with bupivacaine 15 mg, 0.15 mg of intrathecal morphine and 15 ,g of fentanyl or GA with sufentanil, both combined with PCA. The primary outcome was morphine consumption with the PCA device. The secondary outcomes were post-operative pain at rest and under stress on a visual analog scale, nausea, pruritus and respiratory depression on a standardized scale. Outcome measures were recorded at 6, 12, 18, 24 and 48 h post-anesthesia. The duration of post-anesthesia care unit (PACU) and hospital stay were recorded. Results: Patients in the SA group consumed at least two times less morphine at each time interval than the GA group: at 48 h, they used 19 ± 17 vs. 81 ± 31 mg (P<0.0001). Post-operative pain at rest was lower in the SA group until the 18th hour and under stress until the 48th. There was more sedation in the GA group until the 18th hour. Little difference was observed in the incidence of pruritus. Nausea was more intense at the 6th hour in the GA group. There was no difference in the respiratory rate. The duration of PACU stay was shorter for the SA group (52 ± 9 vs. 73 ± 11 min, P<0.0001) as was the duration of hospital stay (2.2 ± 0.4 vs. 3.3 ± 0.7 days, P=0.01). Conclusions: It is concluded that intrathecal morphine 0.15 mg with 15 ,g of fentanyl decreases post-operative pain and morphine consumption by PCA without increasing adverse reactions for women undergoing an abdominal hysterectomy. [source] Energy relaxation processes of photo-generated carriers in Mg doped (0001)GaN and (1-101)GaNPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 6 2008J. Saida Abstract Energy relaxation processes of photo-generated excess carriers in Mg doped GaN epitaxial layers were investigated at room temperature, with photoluminescence intensity correlation method using femto-second pulse laser as the excitation source. The decay curve was well fitted by exponential decay with two time constants. The slow process of the order of 100 ps was attributed to the energy relaxation of electrons in the conduction band, while the fast process of the order of several pico-seconds was attributed to the capture process in the impurity band near the valence band. Little difference has been found out between the results for (0001)GaN and those for (1-101)GaN. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] The neighbor enclosed area tracking algorithm for extratropical wintertime cyclonesATMOSPHERIC SCIENCE LETTERS, Issue 4 2009Masaru Inatsu Abstract The neighbor enclosed area tracking (NEAT) algorithm is proposed as an alternative method to conventional point-to-point cyclone tracking approaches. NEAT enables us to count the genesis and tracks of individual cyclones as well as the number of merged and separated cyclones. Little difference in cyclone genesis or track climatology in the Northern Hemisphere was found between NEAT and conventional tracking. The NEAT results indicate a high probability of cyclone merger in the western Pacific and western Atlantic. Composite maps and backtracking from merged cyclones reveal the characteristics of merged cyclones. Copyright © 2009 Royal Meteorological Society [source] A comparison of counselee and counselor satisfaction in reproductive genetic counselingCLINICAL GENETICS, Issue 2 2007CM Aalfs Important insights in the process of genetic counseling can be provided by establishing levels of satisfaction. The aim of our study was to compare counselees' and counselors' satisfaction with the initial consultation in reproductive genetic counseling and to gain insight into the factors associated with their contentment. One hundred and fifty-one women and 11 counselors participated in this study. Pre-test questionnaires included counselees' socio-demographic, physical and psychological characteristics, i.e. their degree of worry, expectations, preferred participation in decision making and experienced degree of control. Post-visit questionnaires asked for counselees' and counselors' satisfaction, counselees' participation in decision making and counselees' Perceived Personal Control (PPC). Little difference was found between counselees' and counselors' overall visit-specific satisfaction (mean 79 vs 74, respectively, on a visual analogue scale from 0 to 100). The correlation between counselees' and counselors' satisfaction was medium sized (r = 0.26, p < 0.01). Counselees' satisfaction was positively associated with being pregnant and with their post-visit PPC. Counselors' satisfaction was positively associated with counselees' post-visit PPC. No other counselee and counselor related variables appeared to be associated with satisfaction, nor was the duration of the consultation. Our findings suggest that, although both groups were satisfied with the consultation, counselees and counselors do not always have equal perceptions of the consultation process and may form their evaluation in different ways. In the assessment of quality of care, evaluation of both counselees' and counselors' satisfaction deserves more attention. [source] A comparison of restricted selection procedures to control genetic gainsJOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 2 2004S. Ieiri Summary Using Monte Carlo simulation, two schemes of restricted selection were compared under various combinations of genetic parameters and constraints on the genetic gains. The first selection scheme is the combination of best linear unbiased prediction (BLUP) evaluation and linear programming technique (BLUP + LP), and the second one is based on the restricted BLUP selection (RBLUP). Selection for two traits was supposed, in which animals were selected to maximize the genetic gain in trait 2 (,g2) under a proportional restriction on the genetic gain in trait 1 (,g1) to satisfy the intended ratio (,g1:,g2). Little differences were found between the two selection schemes with respect to the genetic gains averaged over replicates. However, in all the cases studied, the variance of genetic gains among replicates under BLUP + LP selection was smaller and less sensitive to the genetic parameters and the intended restriction than RBLUP selection. Under the situations of antagonistic selection, the difference tended to be larger. When the heritabilities of the two traits were different, RBLUP selection remarkably increased the variance of genetic gain in a trait with a higher heritability. These results suggest that BLUP + LP selection should always be preferable to RBLUP selection because of the smaller risk of selection. This choice is especially important for the situation where the genetic parameters act as limiting factors for the achievement of intended genetic gains. Zusammenfassung Unter Verwendung von Monte Carlo Simulation wurden zwei verschiedene Selektionsstrategien mit verschiedenen Kombinationen genetischer Parameter und Beschränkungen des genetischen Fortschritts verglichen. Die erste Selektionsstrategie stellt eine Kombination von BLUP-Schätzung und linearer Programmiertechnik (BLUP + LP) dar, die zweite Strategie basiert auf einer reduzierten BLUP-Selektion (RBLUP). Die Selektion wurde auf zwei Merkmalen basierend durchgeführt in welchen Tiere ausgewählt wurden, um den genetischen Fortschritt in Merkmal 2 zu maximieren (,g2) unter proportionaler Restriktion des genetischen Fortschritts in Merkmal 1 (,g1), um die beabsichtigte Beziehung zu erreichen (,g1:,g2). Kleine Unterschiede wurden zwischen den beiden Selektionsstrategien in Bezug auf den mittleren genetischen Fortschritt über Wiederholungen gefunden. Wie auch immer, in allen untersuchten Fällen war die Varianz des genetischen Fortschritts zwischen Wiederholungen mit der BLUP + LP-Selektion geringer und weniger abhängig in Bezug auf die genetischen Parameter und die beabsichtigte Restriktion im Vergleich zur RBLUP-Selektion. Unter den Gegebenheiten der gegenläufigen Selektion schien der Unterschied größer zu werden. Wenn die Heritabilitäten der beiden Merkmale unterschiedlich waren, stieg die Varianz des genetischen Fortschritts bei RBLUP in einem Merkmal mit höherer Heritabilität außergewöhnlich. Diese Ergebnisse deuten an, dass BLUP + LP-Selektion gegenüber RBLUP aufgrund des geringeren Selektionsrisikos stets bevorzugt werden sollte. Diese Wahl ist vornehmlich wichtig für die Situation, in der die genetischen Parameter ein limitierender Faktor zur Erreichung von genetischem Fortschritt sind. [source] The efficacy of a protective cream in a real-world apprentice hairdresser environmentCONTACT DERMATITIS, Issue 3 2001D. Perrenoud The object of this study was to compare the protective action of a new barrier cream (Excipial Protect®, Spirig Pharma AG, Egerkingen, Switzerland) to its vehicle in the context of hand irritation of apprentice hairdressers caused by repeated shampooing and exposure to hair-care products. This was a double-blind cross-over comparing Excipial Protect® (containing aluminium chlorohydrate 5% as active ingredient) against its vehicle alone. The efficacy of the creams was evaluated taking into account: (1) clinical scores by researchers, (2) biometric measurements, (3) subjective opinions of the subjects. An analysis of variance was performed considering order of application, degree of atopy, and reported number of shampoos. We observed very little difference in efficacy between the protective cream and its vehicle. The presence, however, of aluminium chlorhydrate in the protective cream was shown to have a positive effect against work-related irritation. The cosmetic qualities of the creams seemed, to the participants, to be as important as their real protective and hydrating properties, an important factor in compliance issues. [source] Business students' perception of corporate social responsibility: the United States, China, and IndiaCORPORATE SOCIAL RESPONSIBILITY AND ENVIRONMENTAL MANAGEMENT, Issue 5 2010Alan Wong Abstract This study used a questionnaire to assess perceptive differences in corporate social responsibility among business students in the United States, China, and India. The study finds that American and Indian respondents attached more importance to the noneconomic aspects of social responsibility than Chinese respondents. Chinese students were more accepting of making facilitating payments to get things moving. Indian respondents placed more emphasis on philanthropy while the US group emphasized legal obligations. In the choice of business goals, there is generally little difference between the three nationality groups. The two main goals selected are taking care of owners' interests and consumers' needs. The study's findings have implications for business school curriculum, public policy, and multinational corporations. Copyright © 2009 John Wiley & Sons, Ltd and ERP Environment. [source] A Community Intervention by Firefighters to Increase 911 Calls and Aspirin Use for Chest PainACADEMIC EMERGENCY MEDICINE, Issue 4 2006Hendrika Meischke PhD Abstract Objectives: To test the effectiveness of an intervention, delivered face-to-face by local firefighters, designed to increase utilization of 911 and self-administration of aspirin for seniors experiencing chest pain. Methods: King County, Washington was divided into 126 geographically distinct areas that were randomized to intervention and control areas. A mailing list identified households of seniors within these areas. More than 20,000 homes in the intervention areas were contacted by local firefighters. Data on all 911 calls for chest pain and self-administration of aspirin were collected from the medical incident report form (MIRF). The unit of analysis was the area. Firefighters delivered a heart attack survival kit (that included an aspirin) and counseled participants on the importance of aspirin and 911 use for chest pain. Main outcome measures were 911 calls for chest pain and aspirin ingestion for a chest pain event, obtained from the MIRFs that are collected by emergency medical services personnel for 2 years after the intervention. Results: There were significantly more calls (16%) among seniors on the mailing list in the intervention than control areas in the first year after the intervention. Among the seniors who were not on the mailing list, there was little difference in the intervention and control areas. The results were somewhat sensitive to the analytical model used and to an outlier in the treatment group. Conclusions: A community-based firefighter intervention can be effective in increasing appropriate response to symptoms of a heart attack among elders. [source] A catchment scale evaluation of the SIBERIA and CAESAR landscape evolution modelsEARTH SURFACE PROCESSES AND LANDFORMS, Issue 8 2010GR Hancock Abstract Landscape evolution models provide a way to determine erosion rates and landscape stability over times scales from tens to thousands of years. The SIBERIA and CAESAR landscape evolution models both have the capability to simulate catchment,wide erosion and deposition over these time scales. They are both cellular, operate over a digital elevation model of the landscape, and represent fluvial and slope processes. However, they were initially developed to solve research questions at different time and space scales and subsequently the perspective, detail and process representation vary considerably between the models. Notably, CAESAR simulates individual events with a greater emphasis on fluvial processes whereas SIBERIA averages erosion rates across annual time scales. This paper describes how both models are applied to Tin Camp Creek, Northern Territory, Australia, where soil erosion rates have been closely monitored over the last 10 years. Results simulating 10,000 years of erosion are similar, yet also pick up subtle differences that indicate the relative strengths and weaknesses of the two models. The results from both the SIBERIA and CAESAR models compare well with independent field data determined for the site over different time scales. Representative hillslope cross-sections are very similar between the models. Geomorphologically there was little difference between the modelled catchments after 1000 years but significant differences were revealed at longer simulation times. Importantly, both models show that they are sensitive to input parameters and that hydrology and erosion parameter derivation has long-term implications for sediment transport prediction. Therefore selection of input parameters is critical. This study also provides a good example of how different models may be better suited to different applications or research questions. Copyright © 2010 John Wiley & Sons, Ltd and Commonwealth of Australia [source] Linking upstream channel instability to downstream degradation: Grenada Lake and the Skuna and Yalobusha River Basins, MississippiECOHYDROLOGY, Issue 3 2009Sean J. Bennett Abstract Unstable fluvial systems are characterized by actively migrating knickpoints, incising channel beds, failing banks, and recruitment of large woody debris and it would appear that river corridors downstream of these processes would be adversely affected or impaired because of higher fluxes of sediment and other riverine products. In north-central Mississippi, the Yalobusha River is one such system and the characteristics of two downstream locations are examined to explore this geomorphic linkage between upstream instability and downstream degradation. For the large woody debris plug along the Yalobusha River, it is found that (1) the deposit is composed mostly of sand covered with a veneer of silt and clay, (2) agrichemicals and enriched concentrations of elements are prevalent, and (3) excessive sedimentation and wood accumulation have forced river flow entirely out-of-bank. For Grenada Lake, it is found that (1) the impounded sediment is predominantly clay, (2) agrichemicals and elements observed throughout the reservoir show no spatial variation, (3) little difference exists in the amount and quality between the sediments deposited in Skuna and Yalobusha River arms, and (4) only a small fraction of the reservoir's storage capacity has been lost because of sedimentation. While excessive sedimentation and large woody debris recruitment have had a marked affect on stream corridor function in the area of the debris plug, the high sediment loads associated with the unstable portions of the Yalobusha River and their associated products have not been communicated to Grenada Lake. The fish consumption advisories within Grenada Lake and its tributaries due to bioaccumulated trace elements and agrichemicals, appear to be independent of the pervasive river channel instability occurring upstream. Copyright © 2009 John Wiley & Sons, Ltd. [source] Residency and movement of stream-dwelling Japanese charr, Salvelinus leucomaenis, in a central Japanese mountain streamECOLOGY OF FRESHWATER FISH, Issue 3 2002T. Nakamura Abstract,,,The residency and movement of stream-dwelling adult (2+ and older) Japanese charr, Salvelinus leucomaenis, were studied by mark and recapture experiments in the Jadani Stream, a headwater tributary of the Tedori River, central Japan, from 1986 to 1989. Of the marked fish, 31.3,58.3% were recaptured in the same pools where they had been caught during the study periods of summer (June,August), autumn (August,November) and winter,spring (November to the next June) and no seasonal movement was observed. The mean distances that the fish moved during the study periods ranged from 139.0 to 502.3 m and many movements longer than 1000 m were observed. Between the resident and the moved fish, there was little difference in body length, growth rate or sex. For the fish that had been resident in the same pools and riffles at previous recaptures, most fish were recaptures in the same locations at the next recapture. Conversely, for the fish that moved previously, most fish were recaptured in different locations from previous sites at the next recapture. These results suggest that Japanese charr exhibit relatively high residency throughout the year, but many fish moved longer distance. The results also suggest the presence of static and mobile components in the charr population. [source] Do Proper Accommodation Assignments Make a Difference?EDUCATIONAL MEASUREMENT: ISSUES AND PRACTICE, Issue 3 2007Examining the Impact of Improved Decision Making on Scores for English Language Learners Does it matter if students are appropriately assigned to test accommodations? Using a randomized method, this study found that individual students assigned accommodations keyed to their particular needs were significantly more efficacious for English language learners (ELLs) and that little difference was reported between students receiving incomplete or not recommended accommodations and no accommodations whatsoever. A sample of third and fourth grade ELLs in South Carolina (N = 272) were randomly assigned to various types of test accommodations on a mathematics assessment. Results indicated that those students who received the appropriate test accommodations, as recommended by a version of a computerized accommodation taxonomy for ELLs (the selection taxonomy for English language learners accommodations; STELLA), had significantly higher test scores than ELLs who received no accommodations or those who received incomplete or not recommended accommodation packages. Additionally, students who were given no test accommodations scored no differently than those students that received accommodation packages that were incomplete or not recommended, given the students' particular needs and challenges. These findings are important in light of research and anecdotal reports that suggest a general lack of systematicity in the current system of assigning accommodations and a tendency to give all available accommodations regardless of individual child characteristics. The results also have important implications for how future accommodation research should be structured to determine the benefits of particular accommodations and accommodation packages. This study would suggest that control and treatment groups should be assembled based on specific student needs in order for direct comparisons to be made. [source] Interventions with injection drug users in UkraineADDICTION, Issue 11 2009Robert E. Booth ABSTRACT Aims To assess the effectiveness of a brief human immunodeficiency virus (HIV) testing and counseling intervention compared to a more time-consuming and expensive street-based intervention with injection drug users (IDUs). Design Cross-over experimental design in which 900 IDUs were recruited, followed by a ,wash-out' period with no recruitment, a reversal of intervention assignment areas and an additional recruitment of 900 IDUs with baseline and 6-month follow-up assessments. Setting Kiev, Odessa and Makeevka/Donesk Ukraine. Participants A total of 1798 IDUs. Measurements HIV testing and audio computer-assisted self-interview (ACASI) data on socio-demographics, drug use and injection and sex-related risk behaviors. Findings Participants in both conditions reduced their injection and sex risks significantly; however, there was little difference in outcomes between conditions. IDUs who knew they were HIV-infected at baseline were significantly more likely to practice safe sex than those unaware or HIV-negative; those who first learned that they were infected at baseline changed their safe sex practices significantly more than those who already knew that they were infected at baseline and those who were HIV-negative. Younger IDUs and those injecting for a shorter period of time reported higher injection and sex risk behaviors following interventions. Conclusions Awareness of HIV infection by street-recruited drug injectors is associated with reduced sex risks. Additional interventions are required for younger IDUs and those injecting for shorter periods of time. [source] Quantitative analyses of the abundance and composition of ammonia-oxidizing bacteria and ammonia-oxidizing archaea of a Chinese upland red soil under long-term fertilization practicesENVIRONMENTAL MICROBIOLOGY, Issue 9 2007Ji-zheng He Summary The abundance and composition of soil ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) were investigated by using quantitative real-time polymerase chain reaction, cloning and sequencing approaches based on amoA genes. The soil, classified as agri-udic ferrosols with pH (H2O) ranging from 3.7 to 6.0, was sampled in summer and winter from long-term field experimental plots which had received 16 years continuous fertilization treatments, including fallow (CK0), control without fertilizers (CK) and those with combinations of fertilizer nitrogen (N), phosphorus (P) and potassium (K): N, NP, NK, PK, NPK and NPK plus organic manure (OM). Population sizes of AOB and AOA changed greatly in response to the different fertilization treatments. The NPK + OM treatment had the highest copy numbers of AOB and AOA amoA genes among the treatments that received mineral fertilizers, whereas the lowest copy numbers were recorded in the N treatment. Ammonia-oxidizing archaea were more abundant than AOB in all the corresponding treatments, with AOA to AOB ratios ranging from 1.02 to 12.36. Significant positive correlations were observed among the population sizes of AOB and AOA, soil pH and potential nitrification rates, indicating that both AOB and AOA played an important role in ammonia oxidation in the soil. Phylogenetic analyses of the amoA gene fragments showed that all AOB sequences from different treatments were affiliated with Nitrosospira or Nitrosospira- like species and grouped into cluster 3, and little difference in AOB community composition was recorded among different treatments. All AOA sequences fell within cluster S (soil origin) and cluster M (marine and sediment origin). Cluster M dominated exclusively in the N, NP, NK and PK treatments, indicating a pronounced difference in the community composition of AOA in response to the long-term fertilization treatments. These findings could be fundamental to improve our understanding of the importance of both AOB and AOA in the cycling of nitrogen and other nutrients in terrestrial ecosystems. [source] Characteristics of microcystin production in the cell cycle of Microcystis viridisENVIRONMENTAL TOXICOLOGY, Issue 1 2004Keishi Kameyama Abstract The correlation between the content of three microcystins (types LR, RR and YR) and the cell cycle of an axenic strain of Microcystis viridis, NIES-102, was investigated under conditions of high (16 mg L,1) and low (1.0 mg L,1) nitrate (NO3 -N) concentrations. Each phase of the cell cycle was identified using a flow cytometer equipped with a 488-nm argon laser using SYTOX Green dye, which binds specifically to nucleic acids and can be exited by the wavelength (Ex/Em: 504/523 nm on DNA). Microcystin concentration showed a positive linear correlation with DNA concentration. The microcystin content of the cells changed remarkably as the cell cycle process proceeded, with maximum content in the G2/M phase and minimum content in the G0/G1 phase. Under a condition of high NO3 -N concentration, the ratio of the total content in the G0/G1 phase to that in the G2/M phase was about 6:1. In contrast, for the two batch cultures the total content was 1.3-fold greater in the G2/M phase. The compositions of the three microcystins also changed along with the cell cycle process, although there was little difference in composition that was related to NO3 -N concentration. Therefore, there were distinctive compositions specific to each phase of the cycle, and the cell cycle of the M. viridis strain was more strongly responsible for both the quantity and the types of microcystin production than was the effect of NO3 -N concentration. © 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 20,25, 2004. [source] An evaluation of the etiology of reduced CYP1A1 messenger RNA expression in the Atlantic tomcod from the Hudson River, New York, USA, using reverse transcriptase polymerase chain reaction analysisENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2001Nirmal K. Roy Abstract Adult Atlantic tomcod, Microgadus tomcod, from the Hudson River, New York State, USA, exhibit reduced inducibility of hepatic cytochrome P4501A1 (CYP1A1) mRNA compared with adult tomcod from the cleaner Miramichi River, New Brunswick, Canada, when treated with coplanar polychlorinated biphenyl (PCB) congeners or 2,3,7,8-tetrachlorodibenzo- p -dioxin. In contrast, little difference in CYP1A1 inducibility is observed between tomcod from these two rivers when treated with polycyclic aromatic hydrocarbons (PAHs). We sought to determine if impaired hepatic CYP1A1 inducibility in Hudson River tomcod results from a multigenerational, genetic adaptation or a single generational, physiological acclimation. Embryos and larvae from controlled experimental crosses of Hudson River and Miramichi River parents were exposed for 24 h to water-borne PCB congener 77 (10 ppm), benzo[a]pyrene (BaP; 10 ppm), or dimethysulfoxide, and CYP1A1 expression was assessed in individual larva using competitive reverse transcriptase polymerase chain reaction (RT-PCR) analysis. The CYP1A1 mRNA was significantly induced in larvae from both populations by BaP (47- and 52-fold) and PCB 77 (9- and 22-fold), although levels of expression were higher in offspring of Miramichi matings. Most important, CYP1A1 mRNA was significantly induced by PCB 77 in larvae from Hudson River parents. Concentrations of dioxin, furan, and PCB congeners were measured in livers and eggs of female tomcod from these two locales to quantify the extent of maternal transfer of contaminants. For both rivers, wet-weight contaminant concentrations were significantly higher (4,7 times) in livers than in eggs of the same females, suggesting that a threshold level of contaminants may have to be reached before CYP1A1 transcription is impaired. We conclude that reduced inducibility of hepatic CYP1A1 mRNA in adult tomcod from the Hudson River is most consistent with single-generational acclimation. [source] An Evaluation of the Cod Fishing Policies of Denmark Iceland and NorwayEUROCHOICES, Issue 3 2004R. Arnason Summary An Evaluation of the Cod Fishing Policies of Denmark, Iceland and Norway Many ocean fisheries are subject to a fundamental economic problem generally referred to as the common property problem. This problem manifests itself as excessive fishing fleets and fishing effort, depressed fish stocks and little or no profitability of the fishing activity, irrespective of the richness of the underlying marine resources. European fisheries represent some of the most dramatic examples of the common property problem. This article employs simple empirical models and recently developed mathematical techniques to examine the economic efficiency of three European fisheries, namely the Danish, Icelandic and Norwegian cod fisheries, The optimal harvesting policies for each of these fisheries are calculated. Comparing these optimal policies with actual harvests provides a measure of the relative efficiency in these three cod fisheries. The comparison confirms the widely held impression that the cod harvesting policies of ail three countries have been hugely inefficient in the past. Moreover, it appears that the inefficiency has been increasing over time. Only during the last few years of our data are there indications that this negative trend may have been halted. Somewhat more surprisingly, in spite of radically different fisheries management systems, we find relatively little difference in the level of stock over-exploitation between these three countries. Politiques compareées de pêhe à la morue au Danemark, en Islande et en Norvège Beaucoup de pêcheries océaniques sont confrontées au problème nique fondamental de la "propriété collective". Celui-ci se manifeste par des flottes de taille excessive, au service d' efforts de péche exagérés, qui aboutissent à détruire les stocks de poisson et la rentabilité des pécheries, en dépit de la richesse des ressources marines sousjacentes. Les pêcheries européennes constituent actuellement l'un des exemples les plus dramatiques des problèmes associés a la propriété collective. On présente ici un modèle empirique assez simple mais associéà de nouvelles techniques mathématiques récemment développé es pour mesurer l' efficacitééconomique de trois types de politiques de pêche à la morue, au Danemark, en Norvège et en Islande. On commence par calculer le volume optimal des prises pour chacun de ces pays. La comparaison entre le niveau optimal et le niveau réel des prises permet de mesurer le degré d' efficacité des politiques suivies. Elle permet de confirmer l'opinion largement répandue selon laquelle les politiques passées ont été extrêmement peu efficaces. En outre, il apparaît que l'inefficacité est croissante avec le temps. C'est seulement dans les toutes dernières années des séries de données que l' on observe un infléchissement de cette tendance négative. Enfin, et c'est le plus surprenant, on trouve peu de differences entre les trois pays en ce qui conceme le degré de surexploitation du stock, et cela, bien que les principes de gestion des pêcheries y soient entiArement différents. Eine Bewertung der Kabeljaufischereipolitik in Dänemark, Island und Norwegen ahlreiche Hochseefischereien tehen einem grundlegenden ftliehen Problem gegenüber, das allgemein als Problem des kollektiven Eigentums bezeichnet wird. Dieses Problem zeigt sich in übermäßig großen Fangflotten und beträchtlichem Fischereiaufwand, geschrumpften Fischbeständen und geringer oder fehlender Rentabilität der Fischerei; dabei ist die Höhe der Fischressourcen unbedeutend für das Problem. Die europäischen Fischereien stellen einige der drastischsten Beispiele für das Problem des kollektiven Eigentums dar. In diesem Beitrag werden einfache empirische Modelle und kürzlich entwickelte mathematische Verfahren angewendet, um die wirtschaftliche Effizienz von drei europäischen Fischereien zu untersuchem der dänischen, der isländischen und der norwegischen Kabeljaufischerei. Für jede dieser Fischereien wird die optimale Nutzungsstrategie berechnet. Aus dem Vergleich dieser optimalen Nutzungsstrategie mit den tatsächlichen Erträgen ergibt sich ein Maß fur die relative Effizienz, die bei diesen drei Kabeljaufischereien vorliegt. Der Vergleich bestätigt den weit verbreiteten Eindruck, dass die Strategien zum Kabeljaufang in alien drei Ländern in der Vergangenheit enorm ineffizient waren. Darüber hinaus wird deutlich, dass die Ineffizienz im Laufe der Zeit zugenommen hat. Lediglich die Daten der letzten jahre enthalten Hinweise darauf, dass dieser negative Trend zum Stillstand gekommen sein könnte. Obwohl sich die Fischwirtschaft in jedem dieser drei Länder sehr stark unterscheidet, lassen sich erstaunlich wenige Unterschiede im Maß der Übernutzung des Fischbestandes finden. [source] Variability of the masticatory process during chewing of elastic model foodsEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 6 2000Claire Lassauzay Many studies show a consistent individual chewing pattern; chewing being governed by a pattern generator and regulated by sensory feedback. The aim of this study was to determine the variation in chewing between sessions, replicates and subjects using elastic model foods. Fifteen young male subjects were selected to chew four food products differing in hardness. Four sessions were performed at 1-wk intervals for each subject and, within each session, the four model foods were presented 3 times each. Jaw movement was recorded simultaneously with masseter and anterior temporalis electromyographic activities. Several chewing characteristics increased progressively from one session to the next; the largest increase occurred from the 1st to the 2nd session, with little difference between the last two sessions. No differences were observed between the samples of the same food product within a session. As mastication progressed, the amplitude and speed of the cycles and the muscular work decreased progressively. The first cycle appeared to be very different from the subsequent for all parameters except for occlusal duration. Thus, under our experimental conditions, the origin and amount of variation in chewing patterns were identified and provide information to improve the accuracy and comparability of results in studies of mastication. [source] Differential Effects of Cold Exposure on Muscle Fibre Composition and Capillary Supply in Hibernator and Non-Hibernator RodentsEXPERIMENTAL PHYSIOLOGY, Issue 5 2001S. Egginton Changes in the composition of fibre types and the capillary supply of skeletal muscle (tibialis anterior) were quantified in rats and hamsters subjected to 8-10 weeks of cold exposure and reduced photoperiod (10 °C, 1 h light-23 h dark). Muscle mass decreased in both species (by 12% and 17%, respectively). Following acclimation to cold there were no specific changes in fibre cross-sectional area (FCSA) in rats, whereas in hamsters there was a substantial atrophy of Type II, but not Type I fibres. In rat muscle there was little difference between the two groups in average capillary to fibre ratio (C:F) (1.76 ± 0.15, normothermia, N; 1.69 ± 0.05, hypothermia, H) and average capillary density (CD) (188 ± 14 mm,2, N; 201 ± 12 mm -2, H). Similarly, the average C:F was unaltered in hamsters (2.75 ± 0.11, N; 2.72 ± 0.15, H), although the 30% smaller fibre size observed with hypothermia resulted in a corresponding increase in average CD, to 1539 ± 80 mm,2 (P < 0.01). However, there was a coordinated regional adaptation to cold exposure in hamsters resulting in capillary rarefaction in the glycolytic cortex and angiogenesis in the oxidative core. Following acclimation of rats to cold there was a reduction in the supply area of individual vessels (capillary domain), particularly in the cortex (9310, N; 8938 ,m2, H; P < 0.05). In contrast, hypothermic hamsters showed only a small decrease in mean domain area in the cortex (948 ,m2, N; 846 ,m2, H; n.s.) but a marked reduction in the core (871 ,m2, N; 604 ,m2, H; P < 0.01). Rats showed little or no change in local capillary supply (LCFR) to fast fibres on acclimation to cold, while in hamsters the LCFR of Type IIb fibres showed a decrease in the cortex (2.7, N; 2.3, H) and an increase in the core (3.0, N; 3.3, H) during acclimation to cold. These data suggest that during a simulated onset of winter rats maintain FCSA and capillary supply as part of an avoidance strategy, whereas hamsters increase muscle capillarity in part as a consequence of disuse atrophy. [source] Effect of Carbon Chain Length in the Substituent of PCBM-like Molecules on Their Photovoltaic PropertiesADVANCED FUNCTIONAL MATERIALS, Issue 9 2010Guangjin Zhao Abstract A series of [6,6]-phenyl-C61 -butyric acid methyl ester (PCBM)-like fullerene derivatives with the butyl chain in PCBM changing from 3 to 7 carbon atoms, respectively (F1,F5), are designed and synthesized to investigate the relationship between photovoltaic properties and the molecular structure of fullerene derivative acceptors. F2 with a butyl chain is PCBM itself for comparison. Electrochemical, optical, electron mobility, morphology, and photovoltaic properties of the molecules are characterized, and the effect of the alkyl chain length on their properties is investigated. Although there is little difference in the absorption spectra and LUMO energy levels of F1,F5, an interesting effect of the alkyl chain length on the photovoltaic properties is observed. For the polymer solar cells (PSCs) based on P3HT as donor and F1,F5, respectively, as acceptors, the photovoltaic behavior of the P3HT/F1 and P3HT/F4 systems are similar to or a little better than that of the P3HT/PCBM device with power conversion efficiencies (PCEs) above 3.5%, while the performances of P3HT/F3 and P3HT/F5-based solar cells are poorer, with PCE values below 3.0%. The phenomenon is explained by the effect of the alkyl chain length on the absorption spectra, fluorescence quenching degree, electron mobility, and morphology of the P3HT/F1,F5 (1:1, w/w) blend films. [source] Modelling thermal degradation of composite materialsFIRE AND MATERIALS, Issue 2 2007Javier Trelles Abstract A one,dimensional, transient thermal degradation heat transfer model for the response of composite materials when exposed to fire is presented. The model can handle layers of different materials. Material properties are functions of temperature. The reaction can be specified using Arrhenius-type parameters or by inputting a density,temperature relationship determined by any experimental technique such as thermogravimetric analysis. The model is validated against the experimental data presented in Boyer's 1984 dissertation. Overall, the model provides excellent agreement with the experimental data. It is shown that very little difference is found between results arrived at by Arrhenius kinetics and results obtained by specifying the easier to measure density,temperature relationship. From this it is concluded that this technique is a viable alternative to Arrhenius-type models. Copyright © 2006 John Wiley & Sons, Ltd. [source] Learner Accuracy and Learner Performance: The Quest for a LinkFOREIGN LANGUAGE ANNALS, Issue 2 2000Janet M. Renou Specifically, we examined learner performance in carrying out three steps of a written and oral grammatically judgment test. First, subjects' ability to identify and correct an error, and to provide the rule, which the correction entailed, was examined according to group membership (communicative or grammar), types of errors, and mode of presentation. In a second phase of the analysis, judgment ability was compared with specific aspects of L2 proficiency. Results show significant differences between the groups in their ability to provide the rule that the correction entailed. Furthermore, significant differences in judgment ability were found depending on whether the item was presented in the written or oral mode. Generally, little difference was found in levels of L2 proficiency between subjects who could correct the error and provide the rule in comparison with those who were only able to correct the error. [source] Genome-wide association studies for discrete traitsGENETIC EPIDEMIOLOGY, Issue S1 2009Duncan C. Thomas Abstract Genome-wide association studies of discrete traits generally use simple methods of analysis based on ,2 tests for contingency tables or logistic regression, at least for an initial scan of the entire genome. Nevertheless, more power might be obtained by using various methods that analyze multiple markers in combination. Methods based on sliding windows, wavelets, Bayesian shrinkage, or penalized likelihood methods, among others, were explored by various participants of Genetic Analysis Workshop 16 Group 1 to combine information across multiple markers within a region, while others used Bayesian variable selection methods for genome-wide multivariate analyses of all markers simultaneously. Imputation can be used to fill in missing markers on individual subjects within a study or in a meta-analysis of studies using different panels. Although multiple imputation theoretically should give more robust tests of association, one participant contribution found little difference between results of single and multiple imputation. Careful control of population stratification is essential, and two contributions found that previously reported associations with two genes disappeared after more precise control. Other issues considered by this group included subgroup analysis, gene-gene interactions, and the use of biomarkers. Genet. Epidemiol. 33 (Suppl. 1):S8,S12, 2009. © 2009 Wiley-Liss, Inc. [source] A transportable mb(Lg) scale for central Europe and implications for low-magnitude Ms,mb discriminationGEOPHYSICAL JOURNAL INTERNATIONAL, Issue 1 2005Howard J. Patton SUMMARY We have extended the mb(Lg) method of Nuttli using root-mean-square (rms) amplitudes corrected for noise and a ,,1 dependence for geometrical spreading. Lg waves recorded on the German Regional Seismic Network (GRSN) for earthquakes in south-central Europe were used to develop an mb(Lg) formula requiring a new calibration constant Crms to keep rms mb(Lg) on the same baseline as Nuttli's traditional formula based on 3rd-peak amplitudes. GRSN stations had to be calibrated for site terms and for Lg attenuation. Lateral variations in LgQ appear to be significant across the study area, and a regional Q model consisting of constant- Q partitions north, south and in the central Alps was developed using measurements based on interstation and two-event, single-station methods. When plotted against surface wave estimates of Mw, rms mb(Lg) measurements in central Europe are found to be consistent with Mw,mb(Lg) relationships for north America and southern Asia, thus supporting the transportability of our mb(Lg) formula. Frequency,wavenumber processing of Gräfenberg Array data enabled us to extract Rayleigh waves for small events, and regional Ms were measured using the Marshall and Basham formula. Our Ms,mb(Lg) relationship extends to Ms 2.5 and agrees well with observations in other regions including the western United States. The discrimination potential of Ms,mb(Lg) observations was examined under realistic monitoring conditions, where path corrections were inferred from earthquake data and applied uniformly to natural sources and explosions. Under these conditions, mb(Pn, P) are greater than mb(Lg) for large NTS explosions; however, Ms,mb scaling slopes are steeper for P waves than they are for Lg, and Ms,mb observations for NTS explosions converge near mb 4. Thus, allowing for measurement errors and additional uncertainty in mb(Pn) due to regional bias, there is little difference in the discrimination potential for Pn and Lg waves at small magnitudes. As such, a regional Ms,mb discriminant based on Lg might be preferred owing to the better detectability of Lg waves for small earthquakes. These results need to be confirmed for explosions at other test sites. Compared to teleseismic experience, regional Ms,mb observations extend the discrimination capability to lower magnitudes by at least one Ms unit. [source] Importance of Unsaturated Zone Flow for Simulating Recharge in a Humid ClimateGROUND WATER, Issue 4 2008Randall J. Hunt Transient recharge to the water table is often not well understood or quantified. Two approaches for simulating transient recharge in a ground water flow model were investigated using the Trout Lake watershed in north-central Wisconsin: (1) a traditional approach of adding recharge directly to the water table and (2) routing the same volume of water through an unsaturated zone column to the water table. Areas with thin (less than 1 m) unsaturated zones showed little difference in timing of recharge between the two approaches; when water was routed through the unsaturated zone, however, less recharge was delivered to the water table and more discharge occurred to the surface because recharge direction and magnitude changed when the water table rose to the land surface. Areas with a thick (15 to 26 m) unsaturated zone were characterized by multimonth lags between infiltration and recharge, and, in some cases, wetting fronts from precipitation events during the fall overtook and mixed with infiltration from the previous spring snowmelt. Thus, in thicker unsaturated zones, the volume of water infiltrated was properly simulated using the traditional approach, but the timing was different from simulations that included unsaturated zone flow. Routing of rejected recharge and ground water discharge at land surface to surface water features also provided a better simulation of the observed flow regime in a stream at the basin outlet. These results demonstrate that consideration of flow through the unsaturated zone may be important when simulating transient ground water flow in humid climates with shallow water tables. [source] What difference does the choice of SES make in health inequality measurement?HEALTH ECONOMICS, Issue 10 2003Adam Wagstaff Abstract This note explores the implications for measuring socioeconomic inequality in health of choosing one measure of SES rather than another. Three points emerge. First, whilst similar rankings in the two the SES measures will result in similar inequalities, this is a sufficient condition not a necessary one. What matters is whether rank differences are correlated with health , if they are not, the measured degree of inequality will be the same. Second, the statistical importance of choosing one SES measure rather than another can be assessed simply by estimating an artificial regression. Third, in the 19 countries examined here, it seems for the most part to make little difference to the measured degree of socioeconomic inequalities in malnutrition among under-five children whether one measures SES by consumption or by an asset-based wealth index. Copyright © 2003 John Wiley & Sons, Ltd. [source] The Vikings on the Continent in Myth and HistoryHISTORY, Issue 290 2003Simon Coupland The Vikings have a bad reputation, and it was no different on the Continent in the middle ages where they were regularly portrayed as brutally cruel, devilishly cunning and of superhuman stature. This article examines the evidence for the Vikings' supposed cruelty, cunning and remarkable height and investigates how true the stereotypes were. What emerges is that all three contained a grain of truth, but led to exaggeration and distortion in later medieval texts and even some ninth-century sources. There were, for example, tall individuals among the invaders, but little difference overall between the height of the average Frank and the average Dane. There were likewise instances of Scandinavian brutality, but not on a large scale, and they were no worse than acts carried out by the Franks in the same period. Nor, surprisingly, is there clear evidence of Viking rape: certainly they were not known for ,rape and pillage' in the ninth century. Finally, though the invaders were capable of duplicity, Carolingian parallels are once again not hard to find. In sum, tales of tall, treacherous and brutal Northmen can be shown to have grown in the telling, and there is an evident gap between the Vikings of myth and the Vikings of history. [source] | |||||||||||||||||||||||||||||||||||||