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Terms modified by Entire Study Selected AbstractsSeasonal spatial dynamics and causes of nest movement in colonies of the invasive Argentine ant (Linepithema humile)ECOLOGICAL ENTOMOLOGY, Issue 5 2006NICOLE E. HELLER Abstract 1.,Colony organisation and movement behaviour of the Argentine ant (Linepithema humile) was studied over 3 years in field populations in California and in captive colonies in the laboratory. This invasive species is highly polydomous and unicolonial; colonies consist of expansive and fluid networks of nests and trails. The spatial and temporal organisation of colonies may contribute to ecological dominance. 2.,Argentine ant nests and inter-nest trails shift in size, abundance, and location, so that colony networks are spatially contracted in the winter and expanded spring to autumn. Colonies occupy permanent sites; ants migrated to and from the same winter nest locations year after year, and occupied 30% of the same nests repeatedly during seasonal migrations. 3.,Nests were moved on average 2,3 m. Forty-two per cent were occupied less than 1 month, 4% the entire study, and the other 54% lasted 3.9 ± 2.3 months (mean ± SD). 4.,Nests were located within 2,4 m of woody plants, in warm sites in the winter and cool sites in the summer. Both humidity and food availability influenced nest-site choice in laboratory colonies. However, when faced with a trade-off between factors, the ants chose humid nest boxes over nest boxes near food, and ants moved nests only in response to changes in humidity and not distance to food. 5.,The results indicate that L. humile colonies are seasonally polydomous, and that nest movements are driven by changes in microclimate. Colony organisation maintains high local density and increases food supply, which may improve the competitive ability of L. humile colonies and reduce opportunities for species coexistence. [source] Disturbance history influences the distribution of stream invertebrates by altering microhabitat parameters: a field experimentFRESHWATER BIOLOGY, Issue 5 2008MICHAEL EFFENBERGER Summary 1. We investigated the effects of local disturbance history and several biotic and abiotic habitat parameters on the microdistribution of benthic invertebrates after an experimental disturbance in a flood-prone German stream. 2. Bed movement patterns during a moderate flood were simulated by scouring and filling stream bed patches (area 0.49 m2) to a depth of 15,20 cm. Invertebrates were investigated using ceramic tiles as standardized substrata. After 1, 8, 22, 29, 36 and 50 days, we sampled one tile from each of 16 replicates of three bed stability treatments (scour, fill and stable controls). For each tile, we also determined water depth, near-bed current velocity, the grain size of the substratum beneath the tile, epilithic algal biomass and standing stock of particulate organic matter (POM). 3. Shortly after disturbance, total invertebrate density, taxon richness and density of the common taxa Baetis spp. and Chironomidae were highest in stable patches. Several weeks after disturbance, by contrast, Baetis spp. and Hydropsychidae were most common in fill and Leuctra spp. in scour patches. The black fly Simulium spp. was most abundant in fill patches from the first day onwards. Community evenness was highest in scour patches during the entire study. 4. Local disturbance history also influenced algal biomass and POM standing stock at the beginning of the experiment, and water depth, current velocity and substratum grain size throughout the experiment. Scouring mainly exposed finer substrata and caused local depressions in the stream bed characterized by slower near-bed current velocity. Algal biomass was higher in stable and scour patches and POM was highest in scour patches. In turn, all five common invertebrate taxa were frequently correlated with one or two of these habitat parameters. 5. Our results suggest that several ,direct' initial effects of local disturbance history on the invertebrates were subsequently replaced by ,indirect' effects of disturbance history (via disturbance-induced changes in habitat parameters such as current velocity or food). [source] Uremic hyperhomocysteinemia: A randomized trial of folate treatment for the prevention of cardiovascular eventsHEMODIALYSIS INTERNATIONAL, Issue 2 2007Areuza C. A. VIANNA Abstract Homocysteine is a risk factor for atherosclerosis in the general population, and serum homocysteine levels are almost universally elevated in chronic renal failure patients. When such patients are treated with dialysis, cardiovascular disease accounts for more than 50% of their mortality, which, in some proportion, may be pathophysiologically related to the elevated serum homocysteine levels. From April 2003 to March 2005, we conducted a 2-year, double-blind, randomized, placebo-controlled trial of 186 patients with end-stage kidney disease due to any cause, who were older than 18 years and stable on hemodialysis. Patients were assigned to receive either oral folic acid 10 mg 3 times a week immediately after every dialysis session under nurse supervision or an identical-appearing placebo for the entire study. On admission, plasma total homocysteine (tHcy) levels were above 13.9 ,mol/L in 96.7% of patients (median 25.0 ,mol/L, range 9.3,104.0 ,mol/L). In the placebo group, tHcy levels remained elevated at 6, 12, and 24 months, while oral folate significantly decreased tHcy to a median value of 10.5 (2.8,20.3) ,mol/L, (p<0.01). During the study, 38 patients (folic acid group 17 vs. placebo group 21; p=0.47) died from cardiovascular disease. Kaplan,Meier life table analysis dealing with the incidence of cardiovascular events, both fatal and nonfatal (myocardial infarction, arrhythmias, angina, heart failure, cerebrovascular accident), showed that 2 years of folic acid treatment and the lowering of the homocysteine blood levels had no effect on cardiovascular events (p=0.41; hazard ratio 1.24, 95% CI 0.74,2.10). However, the carotid artery intima-media wall thickness measured in a blinded fashion decreased from 1.94 ± 0.59 mm to 1.67 ± 0.38 mm (p<0.01) after 2 years of folate therapy. In this short-term study of uremic patients, 2 years of folic acid supplementation normalized the tHcy blood levels in 92.3% of patients but did not change the incidence of cardiovascular events compared with the control group. However, ultrasonography of the common carotid arteries performed at entry and 24 months later showed a significant decrease in intima-media thickness with folate supplementation. This suggests that early folate supplementation may benefit patients with chronic renal failure by preventing cardiovascular deterioration. [source] How adherent to treatment with azathioprine are patients with Crohn's disease in long-term remission?INFLAMMATORY BOWEL DISEASES, Issue 4 2007Gerassimos J. Mantzaris MD Abstract Background: Patients with longstanding quiescent Crohn's disease on azathioprine usually maintain an excellent quality of life but are also concerned about long-term safety. This may affect adherence to treatment. The aim of the present study was to assess the adherence to azathioprine in a cohort of patients with Crohn's disease in long-term remission. Methods: Thirty patients with Crohn's disease in remission on azathioprine for ,48 months were enrolled in the study. All were asked to record the number of azathioprine tablets they consumed daily. Notes were kept every other month for 6 months. Adherence was defined as consumption of ,80% of medication. Results: Most patients (18/28, 74.3%) were not adherent to treatment. The mean (±SD) daily dose of azathioprine in adherent and nonadherent patients was 145 ± 45 mg and 102 ± 20 mg, respectively. However, there were no significant differences between the 2 groups in the mean IBDQ score and mean Crohn's Disease Activity Index (CDAI) score, both throughout the entire study and at each time point of the study. Male gender, single status, and consumption of >5 concomitant medications were associated with nonadherence. Conclusions: Most patients with Crohn's disease in longstanding remission had low self-reported adherence to azathioprine. Both male gender and single status were associated with nonadherence to azathioprine, whereas disease factors were not related to self-reported adherence. Patients considered nonadherent to treatment maintained disease remission and a quality of life similar to patients who were adherent to treatment. (Inflamm Bowel Dis 2006) [source] Methodological rigour within a qualitative frameworkJOURNAL OF ADVANCED NURSING, Issue 4 2004Gerard A. Tobin BSc MSc RGN RMN RCNT RNT Aim., This paper discusses the literature on establishing rigour in research studies. It describes the methodological trinity of reliability, validity and generalization and explores some of the issues relating to establishing rigour in naturalistic inquiry. Background., Those working within the naturalistic paradigm have questioned the issue of using validity, reliability and generalizability to demonstrate robustness of qualitative research. Triangulation has been used to demonstrate confirmability and completeness and has been one means of ensuring acceptability across paradigms. Emerging criteria such as goodness and trustworthiness can be used to evaluate the robustness of naturalistic inquiry. Discussion., It is argued that the transference of terms across paradigms is inappropriate; however, if we reject the concepts of validity and reliability, we reject the concept of rigour. Rejection of rigour undermines acceptance of qualitative research as a systematic process that can contribute to the advancement of knowledge. Emerging criteria for demonstrating robustness in qualitative inquiry, such as authenticity, trustworthiness and goodness, need to be considered. Goodness, when not seen as a separate construct but as an integral and embedded component of the research process, should be useful in assuring quality of the entire study. Triangulation is a tried and tested means of offering completeness, particularly in mixed-method research. When multiple types of triangulation are used appropriately as the ,triangulation state of mind', they approach the concept of crystallization, which allows for infinite variety of angles of approach. Conclusion., Qualitative researchers need to be explicit about how and why they choose specific legitimizing criteria in ensuring the robustness of their inquiries. A shift from a position of fundamentalism to a more pluralistic approach as a means of legitimizing naturalistic inquiry is advocated. [source] Comparison of clinical outcome parameters, the Patient Benefit Index (PBI-k) and patient satisfaction after ablative fractional laser treatment of peri-orbital rhytides,LASERS IN SURGERY AND MEDICINE, Issue 3 2010Syrus Karsai MD Abstract Background Laser treatment of facial rhytides has evolved as a major modality of aesthetic surgery. Published results, while generally encouraging, feature highly diverse evaluation methods, which makes an evidence-based assessment of treatment efficacy and safety all but impossible. Objective To compare the results of different instruments of measurement. Patients/Methods Twenty-eight patients were enrolled and completed the entire study. They received a single ablative fractional treatment of the peri-orbital region. The evaluation included the Fitzpatrick wrinkle score, the profilometric measurement of wrinkle depth and the Patient Benefit Index (both before and 3 months after treatment) as well as the assessment of patient satisfaction (1, 3, 6 days and 3 months after treatment). Results All assessment instruments showed a significant, albeit moderate, improvement. The agreement between assessment methods was poor. Despite claiming to assess basically the same parameter, the Fitzpatrick wrinkle score and profilometry differed significantly, and neither assessment instrument showed any appreciable correlation with any other. Conclusions The outcome assessment of rhytide therapy,regardless of the method used,shows substantial room for improvement. Strict methodological precautions ought to be applied for ,objective' evaluation methods like photographic scoring and profilometry. Subjective methods of assessment are essential and might serve as a main outcome parameter. Finally, critical reappraisal of published treatment results seems warranted to review the quality of their methodology. Lasers Surg. Med. 42:215,223, 2010. © 2010 Wiley-Liss, Inc. [source] Modelling and parameter comparison of equivalent circuits on the basis of impedance measurements of stainless steelsMATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 4 2006M. Slemnik Abstract In our former work [1] we have discussed the impedance of differently heat treated steels X20Cr13 in 0.1 M H2SO4, undergoing an active passive transition. Impedance spectra were interpreted in terms of a model by Armstrong [2, 3], describing the electrochemical reaction at interfaces with adsorbed intermediates. The present work was performed in order to study this phenomenon in more detail, with computer simulations of a new created and more convenient equivalent circuit in comparison with the former model. Computer simulations of equivalent circuits were also made in the region of passivity which was also continuation of our earlier work [4]. In this sense the entire study for these steels was completed by collating distinctive parameter values, demonstrating electrochemical characteristics of steel X20Cr13, undergoing different heat treatments in the active-passive and passive region. [source] The changes in serum leptin, body fat mass and insulin resistance after renal transplantationCLINICAL TRANSPLANTATION, Issue 1 2003S Mehmet Kayacan Abstract:,Background:, In this prospective-controlled study, we aimed to investigate the effect of changes in insulin resistance and anthropometrical parameters on serum leptin levels (SLL) after renal transplantation (Tx). Patients and methods:, Thirty-four patients (M/F: 19/15, mean age: 29 ± 9 yr) and 30 age and sex-matched healthy controls (C) were included. Body weight, subscapular, suprailiac, periumbilical, biceps and triceps skinfold thicknesses, neck, wrist, hip and waist circumferences, as well as body mass index and body fat mass were measured as anthropometrical parameters. In order to measure the serum glucose, insulin and SLL, blood samples were obtained before and 1 wk, 1 and 6 months after Tx. Homeostasis Model Assessment (HOMA) values were calculated as an index of insulin resistance. Results:, Serum leptin levels (SLL) of the patients at pre-Tx were significantly higher than C (21.5 ± 3.5 vs. 7.8 ± 0.9 ng/mL, p = 0.002) and decreased at first week after Tx (from 21.5 ± 3.5 to 8.4 ± 1.5 ng/mL, p < 0.001). Thereafter, it gradually increased to 12.8 ± 2.1 ng/mL in the first month and to 14.4 ± 2.1 ng/mL in the sixth month after Tx. Serum leptin levels at sixth month were significantly higher than C (p = 0.005). Serum insulin and HOMA values changed similar to SLL after Tx. Correlations between SLL and HOMA persisted during the study period [pre-Tx (r: 0.40) and at first (r: 0.38) and sixth (r: 0.47) months]. In linear regression analysis, HOMA and fat mass were found as independent variables for predicting SLL at the sixth month after Tx. Conclusion:, Serum leptin levels dramatically decreased immediately after Tx and significantly correlated with serum insulin levels and HOMA during the entire study. Increase in SLL at sixth months was probably because of increase in fat mass, insulin resistance and steroid use in renal transplant recipients. [source] | |||||||||||||