952 resultados para Reduced-Impact Logging
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STUDY OBJECTIVES 1) To investigate the impact of acetazolamide, a drug commonly prescribed for altitude sickness, on cortical oscillations in patients with obstructive sleep apnea syndrome (OSAS). 2) To examine alterations in the sleep EEG after short-term discontinuation of continuous positive airway pressure (CPAP) therapy. DESIGN Data from two double-blind, placebo-controlled randomized cross-over design studies were analyzed. SETTING Polysomnographic recordings in sleep laboratory at 490 m and at moderate altitudes in the Swiss Alps: 1630 or 1860 m and 2590 m. PATIENTS Study 1: 39 OSAS patients. Study 2: 41 OSAS patients. INTERVENTIONS Study 1: OSAS patients withdrawn from treatment with CPAP. Study 2: OSAS patients treated with autoCPAP. Treatment with acetazolamide (500-750 mg) or placebo at moderate altitudes. MEASUREMENTS AND RESULTS An evening dose of 500 mg acetazolamide reduced slow-wave activity (SWA; approximately 10%) and increased spindle activity (approximately 10%) during non-REM sleep. In addition, alpha activity during wake after lights out was increased. An evening dose of 250 mg did not affect these cortical oscillations. Discontinuation of CPAP therapy revealed a reduction in SWA (5-10%) and increase in beta activity (approximately 25%). CONCLUSIONS The higher evening dose of 500 mg acetazolamide showed the "spectral fingerprint" of Benzodiazepines, while 250 mg acetazolamide had no impact on cortical oscillations. However, both doses had beneficial effects on oxygen saturation and sleep quality.
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I modeled the cumulative impact of hydroelectric projects with and without commercial fishing weirs and water-control dams on the production, survival to the sea, and potential fecundity of migrating female silver-phase American eels, Anguilla rostrata in the Kennebec River basin, Maine, This river basin has 22 hydroelectric projects, 73 water-control dams, and 15 commercial fishing weir sites. The modeled area included an 8,324 km(2) segment of the drainage area between Merrymeeting Bay and the upper limit of American eel distribution in the basin. One set of input,, (assumed or real values) concerned population structure (Le., population density and sex ratio changes throughout the basin, female length-class distribution, and drainage area between dams), Another set concerned factors influencing survival and potential fecundity of migrating American eels (i.e., pathway sequences through projects, survival rate per project by length-class. and length-fecundity relationship). Under baseline conditions about 402,400 simulated silver female American eels would be produced annually reductions in their numbers due to dams and weirs would reduce the realized fecundity (i.e., the number of eggs produced by all females that survived the migration). Without weirs or water-control dams, about 63% of the simulated silverphase American eels survived their freshwater spawning migration run to the sea when the survival rate at each hydroelectric dam was 9017, 40% survived at 80% survival per dam, and 18% survived at 60% survival per dam. Removing the lowermost hydroelectric dam on the Kennebec River increased survival by 6.0-7.6% for the basin. The efficient commercial weirs reduced survival to the sea to 69-76%( of what it would have been without weirs', regardless of survival rates at hydroelectric dams. Water-control dams had little impact on production in this basin because most were located in the upper reaches of tributaries. Sensitivity analysis led to the conclusion that small changes in population density and female length distribution had greater effects on survival and realized fecundity than similar changes in turbine survival rate. The latter became more important as turbine survival rate decreased. Therefore, it might be more fruitful to determine population distribution in basins of interest than to determine mortality rate at each hydroelectric project.
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PURPOSE Blood loss and blood substitution are associated with higher morbidity after major abdominal surgery. During major liver resection, low local venous pressure, has been shown to reduce blood loss. Ambiguity persists concerning the impact of local venous pressure on blood loss during open radical cystectomy. We aimed to determine the association between intraoperative blood loss and pelvic venous pressure (PVP) and determine factors affecting PVP. MATERIAL AND METHODS In the frame of a single-center, double-blind, randomized trial, PVP was measured in 82 patients from a norepinephrine/low-volume group and in 81 from a control group with liberal hydration. For this secondary analysis, patients from each arm were stratified into subgroups with PVP <5 mmHg or ≥5 mmHg measured after cystectomy (optimal cut-off value for discrimination of patients with relevant blood loss according to the Youden's index). RESULTS Median blood loss was 800 ml [range: 300-1600] in 55/163 patients (34%) with PVP <5 mmHg and 1200 ml [400-3000] in 108/163 patients (66%) with PVP ≥5 mmHg; (P<0.0001). A PVP <5 mmHg was measured in 42/82 patients (51%) in the norepinephrine/low-volume group and 13/81 (16%) in the control group (P<0.0001). PVP dropped significantly after removal of abdominal packing and abdominal lifting in both groups at all time points (at begin and end of pelvic lymph node dissection, end of cystectomy) (P<0.0001). No correlation between PVP and central venous pressure could be detected. CONCLUSIONS Blood loss was significantly reduced in patients with low PVP. Factors affecting PVP were fluid management and abdominal packing.
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BACKGROUND Although different prognostic factors for patients with renal cell carcinoma (RCC) and vena cava tumor thrombus (TT) have been studied, the prognostic value of histologic subtype in these patients remains unclear. OBJECTIVE We analyzed the impact of histologic subtype on cancer-specific survival (CSS). DESIGN, SETTINGS, AND PARTICIPANTS We retrospectively analyzed the records of 1774 patients with RCC and TT who underwent radical nephrectomy and tumor thrombectomy from 1971 to 2012 at 22 US and European centers. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Multivariable ordered logistic and Cox regression models were used to quantify the impact of tumor histology on CSS. RESULTS AND LIMITATIONS Overall 5-yr CSS was 53.4% (confidence interval [CI], 50.5-56.2) in the entire group. TT level (according to the Mayo classification of macroscopic venous invasion in RCC) was I in 38.5% of patients, II in 30.6%, III in 17.3%, and IV in 13.5%. Histologic subtypes were clear cell renal cell carcinoma (cRCC) in 89.9% of patients, papillary renal cell carcinoma (pRCC) in 8.5%, and chromophobe RCC in 1.6%. In univariable analysis, pRCC was associated with a significantly worse CSS (p<0.001) compared with cRCC. In multivariable analysis, the presence of pRCC was independently associated with CSS (hazard ratio: 1.62; CI, 1.01-2.61; p<0.05). Higher TT level, positive lymph node status, distant metastasis, and fat invasion were also independently associated with CSS. CONCLUSIONS In our multi-institutional series, we found that patients with pRCC and vena cava TT who underwent radical nephrectomy and tumor thrombectomy had significantly worse cancer-specific outcomes when compared with patients with other histologic subtypes of RCC. We confirmed that higher TT level and fat invasion were independently associated with reduced CSS.
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Background Honeybees provide economically and ecologically vital pollination services to crops and wild plants. During the last decade elevated colony losses have been documented in Europe and North America. Despite growing consensus on the involvement of multiple causal factors, the underlying interactions impacting on honeybee health and colony failure are not fully resolved. Parasites and pathogens are among the main candidates, but sublethal exposure to widespread agricultural pesticides may also affect bees. Methodology/Principal Findings To investigate effects of sublethal dietary neonicotinoid exposure on honeybee colony performance, a fully crossed experimental design was implemented using 24 colonies, including sister-queens from two different strains, and experimental in-hive pollen feeding with or without environmentally relevant concentrations of thiamethoxam and clothianidin. Honeybee colonies chronically exposed to both neonicotinoids over two brood cycles exhibited decreased performance in the short-term resulting in declining numbers of adult bees (−28%) and brood (−13%), as well as a reduction in honey production (−29%) and pollen collections (−19%), but colonies recovered in the medium-term and overwintered successfully. However, significantly decelerated growth of neonicotinoid-exposed colonies during the following spring was associated with queen failure, revealing previously undocumented long-term impacts of neonicotinoids: queen supersedure was observed for 60% of the neonicotinoid-exposed colonies within a one year period, but not for control colonies. Linked to this, neonicotinoid exposure was significantly associated with a reduced propensity to swarm during the next spring. Both short-term and long-term effects of neonicotinoids on colony performance were significantly influenced by the honeybees’ genetic background. Conclusions/Significance Sublethal neonicotinoid exposure did not provoke increased winter losses. Yet, significant detrimental short and long-term impacts on colony performance and queen fate suggest that neonicotinoids may contribute to colony weakening in a complex manner. Further, we highlight the importance of the genetic basis of neonicotinoid susceptibility in honeybees which can vary substantially.
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This study investigated the impact of gender, the gender-related self-concept (agency and communion), and the timing of parenthood on objective career success of 1,015 highly educated professionals. Hypotheses derived from a dual-impact model of gender and career-related processes were tested in a 5-wave longitudinal study over a time span of 10 years starting with participants’ career entry. In line with our hypotheses we found that the communal component of the gender self-concept had an impact on parenthood, and the agentic component influenced work hours and objective career success (salary, status) of both women and men. Parenthood had a negative direct influence on women’s work hours and a negative indirect influence on women’s objective career success. Women who had their first child around career entry were relatively least successful over the observation period. Men’s career success was independent of parenthood. Sixty-five percent of variance in women’s career success and 33% of variance in men’s career success was explained by the factors analyzed here. Mothers with partners working full time reduced their work hours more than mothers with partners not working full time. A test for a possible reverse influence of career success on the decision to become a parent revealed no effect for men and equivocal effects for women. We conclude that the transition to parenthood still is a crucial factor for women’s career development both from an external gender perspective (expectations, gender roles) and from an internal perspective (gender-related self-concept).
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Large uncertainties exist concerning the impact of Greenland ice sheet melting on the Atlantic meridional overturning circulation (AMOC) in the future, partly due to different sensitivity of the AMOC to freshwater input in the North Atlantic among climate models. Here we analyse five projections from different coupled ocean–atmosphere models with an additional 0.1 Sv (1 Sv = 10 6 m3/s) of freshwater released around Greenland between 2050 and 2089. We find on average a further weakening of the AMOC at 26°N of 1.1 ± 0.6 Sv representing a 27 ± 14% supplementary weakening in 2080–2089, as compared to the weakening relative to 2006–2015 due to the effect of the external forcing only. This weakening is lower than what has been found with the same ensemble of models in an identical experimen - tal set-up but under recent historical climate conditions. This lower sensitivity in a warmer world is explained by two main factors. First, a tendency of decoupling is detected between the surface and the deep ocean caused by an increased thermal stratification in the North Atlantic under the effect of global warming. This induces a shoaling of ocean deep ventilation through convection hence ventilating only intermediate levels. The second important effect concerns the so-called Canary Current freshwater leakage; a process by which additionally released fresh water in the North Atlantic leaks along the Canary Current and escapes the convection zones towards the subtropical area. This leakage is increasing in a warming climate, which is a consequence of decreasing gyres asymmetry due to changes in Ekman rumping. We suggest that these modifications are related with the northward shift of the jet stream in a warmer world. For these two reasons the AMOC is less susceptible to freshwater perturbations (near the deep water formation sides) in the North Atlantic as compared to the recent historical climate conditions. Finally, we propose a bilinear model that accounts for the two former processes to give a conceptual explanation about the decreasing AMOC sensitivity due to freshwater input. Within the limit of this bilinear model, we find that 62 ± 8% of the reduction in sensitivity is related with the changes in gyre asymmetry and freshwater leakage and 38 ± 8% is due to the reduction in deep ocean ventilation associated with the increased stratification in the North Atlantic.
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PURPOSE Based on a nation-wide database, this study analysed the influence of methotrexate (MTX), TNF inhibitors and a combination of the two on uveitis occurrence in JIA patients. METHODS Data from the National Paediatric Rheumatological Database in Germany were used in this study. Between 2002 and 2013, data from JIA patients were annually documented at the participating paediatric rheumatological sites. Patients with JIA disease duration of less than 12 months at initial documentation and ≥2 years of follow-up were included in this study. The impact of anti-inflammatory treatment on the occurrence of uveitis was evaluated by discrete-time survival analysis. RESULTS A total of 3,512 JIA patients (mean age 8.3±4.8 years, female 65.7%, ANA-positive 53.2%, mean age at arthritis onset 7.8±4.8 years) fulfilled the inclusion criteria. Mean total follow-up time was 3.6±2.4 years. Uveitis developed in a total of 180 patients (5.1%) within one year after arthritis onset. Uveitis onset after the first year was observed in another 251 patients (7.1%). DMARD treatment in the year before uveitis onset significantly reduced the risk for uveitis: MTX (HR 0.63, p=0.022), TNF inhibitors (HR 0.56, p<0.001) and a combination of the two (HR 0.10, p<0.001). Patients treated with MTX within the first year of JIA had an even a lower uveitis risk (HR 0.29, p<0.001). CONCLUSION The use of DMARDs in JIA patients significantly reduced the risk for uveitis onset. Early MTX use within the first year of disease and the combination of MTX with a TNF inhibitor had the highest protective effect. This article is protected by copyright. All rights reserved.
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The long-term risk associated with different coronary artery disease (CAD) presentations in women undergoing percutaneous coronary intervention (PCI) with drug-eluting stents (DES) is poorly characterized. We pooled patient-level data for women enrolled in 26 randomized clinical trials. Of 11,577 women included in the pooled database, 10,133 with known clinical presentation received a DES. Of them, 5,760 (57%) had stable angina pectoris (SAP), 3,594 (35%) had unstable angina pectoris (UAP) or non-ST-segment-elevation myocardial infarction (NSTEMI), and 779 (8%) had ST-segment-elevation myocardial infarction (STEMI) as clinical presentation. A stepwise increase in 3-year crude cumulative mortality was observed in the transition from SAP to STEMI (4.9% vs 6.1% vs 9.4%; p <0.01). Conversely, no differences in crude mortality rates were observed between 1 and 3 years across clinical presentations. After multivariable adjustment, STEMI was independently associated with greater risk of 3-year mortality (hazard ratio [HR] 3.45; 95% confidence interval [CI] 1.99 to 5.98; p <0.01), whereas no differences were observed between UAP or NSTEMI and SAP (HR 0.99; 95% CI 0.73 to 1.34; p = 0.94). In women with ACS, use of new-generation DES was associated with reduced risk of major adverse cardiac events (HR 0.58; 95% CI 0.34 to 0.98). The magnitude and direction of the effect with new-generation DES was uniform between women with or without ACS (pinteraction = 0.66). In conclusion, in women across the clinical spectrum of CAD, STEMI was associated with a greater risk of long-term mortality. Conversely, the adjusted risk of mortality between UAP or NSTEMI and SAP was similar. New-generation DESs provide improved long-term clinical outcomes irrespective of the clinical presentation in women.
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BACKGROUND The impact of early treatment with immunomodulators (IM) and/or TNF antagonists on bowel damage in Crohn's disease (CD) patients is unknown. AIM To assess whether 'early treatment' with IM and/or TNF antagonists, defined as treatment within a 2-year period from the date of CD diagnosis, was associated with development of lesser number of disease complications when compared to 'late treatment', which was defined as treatment initiation after >2 years from the time of CD diagnosis. METHODS Data from the Swiss IBD Cohort Study were analysed. The following outcomes were assessed using Cox proportional hazard modelling: bowel strictures, perianal fistulas, internal fistulas, intestinal surgery, perianal surgery and any of the aforementioned complications. RESULTS The 'early treatment' group of 292 CD patients was compared to the 'late treatment' group of 248 CD patients. We found that 'early treatment' with IM or TNF antagonists alone was associated with reduced risk of bowel strictures [hazard ratio (HR) 0.496, P = 0.004 for IM; HR 0.276, P = 0.018 for TNF antagonists]. Furthermore, 'early treatment' with IM was associated with reduced risk of undergoing intestinal surgery (HR 0.322, P = 0.005), and perianal surgery (HR 0.361, P = 0.042), as well as developing any complication (HR 0.567, P = 0.006). CONCLUSIONS Treatment with immunomodulators or TNF antagonists within the first 2 years of CD diagnosis was associated with reduced risk of developing bowel strictures, when compared to initiating these drugs >2 years after diagnosis. Furthermore, early immunomodulators treatment was associated with reduced risk of intestinal surgery, perianal surgery and any complication.
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The aim of this study was to test the influence of different degrees of additional illumination on visual caries detection using the International Caries Detection and Assessment System (ICDAS). Two calibrated examiners assessed 139 occlusal surfaces of extracted permanent molars using a standard operation lamp with or without an additional headlamp providing three default brightness intensities. Histology served as the gold standard. Pooled data showed no differences in sensitivities. Specificities were not influenced by additional light. The area under the curve for the Marthaler classification D3 threshold was significantly lower when an additional strong headlamp was used (0.59 compared to 0.69-0.72 when reduced illumination intensities were used). One of the two examiners also had a significantly lower sensitivity for the D1 threshold when an additional headlamp was used. The use of additional white light led to a reduced detection of dentine lesions.
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PURPOSE To investigate whether the effects of hybrid iterative reconstruction (HIR) on coronary artery calcium (CAC) measurements using the Agatston score lead to changes in assignment of patients to cardiovascular risk groups compared to filtered back projection (FBP). MATERIALS AND METHODS 68 patients (mean age 61.5 years; 48 male; 20 female) underwent prospectively ECG-gated, non-enhanced, cardiac 256-MSCT for coronary calcium scoring. Scanning parameters were as follows: Tube voltage, 120 kV; Mean tube current time-product 63.67 mAs (50 - 150 mAs); collimation, 2 × 128 × 0.625 mm. Images were reconstructed with FBP and with HIR at all levels (L1 to L7). Two independent readers measured Agatston scores of all reconstructions and assigned patients to cardiovascular risk groups. Scores of HIR and FBP reconstructions were correlated (Spearman). Interobserver agreement and variability was assessed with ĸ-statistics and Bland-Altmann-Plots. RESULTS Agatston scores of HIR reconstructions were closely correlated with FBP reconstructions (L1, R = 0.9996; L2, R = 0.9995; L3, R = 0.9991; L4, R = 0.986; L5, R = 0.9986; L6, R = 0.9987; and L7, R = 0.9986). In comparison to FBP, HIR led to reduced Agatston scores between 97 % (L1) and 87.4 % (L7) of the FBP values. Using HIR iterations L1 - L3, all patients were assigned to identical risk groups as after FPB reconstruction. In 5.4 % of patients the risk group after HIR with the maximum iteration level was different from the group after FBP reconstruction. CONCLUSION There was an excellent correlation of Agatston scores after HIR and FBP with identical risk group assignment at levels 1 - 3 for all patients. Hence it appears that the application of HIR in routine calcium scoring does not entail any disadvantages. Thus, future studies are needed to demonstrate whether HIR is a reliable method for reducing radiation dose in coronary calcium scoring.
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BACKGROUND Surgical-site infections (SSIs) are the most common complications after surgery. An influence from talking and distractions during surgery on patient outcomes has been suggested, but there is limited evidence. The aim of this prospective observational study was to assess the relationship between intraoperative communication within the surgical team and SSI, and between intraoperative distractions and SSI. METHODS This prospective observational study included patients undergoing elective, open abdominal procedures. For each procedure, intraoperative case-relevant and case-irrelevant communication, and intraoperative distractions were observed continuously on site. The influence of communication and distractions on SSI after surgery was assessed using logistic regressions, adjusting for risk factors. RESULTS A total of 167 observed procedures were analysed; their mean(s.d.) duration was 4·6(2·1) h. A total of 24 SSIs (14·4 per cent) were diagnosed. Case-relevant communication during the procedure was independently associated with a reduced incidence of organ/space SSI (propensity score-adjusted odds ratio 0·86, 95 per cent c.i. 0·77 to 0·97; P = 0·014). Case-irrelevant communication during the closing phase of the procedure was independently associated with increased incidence of incisional SSI (propensity score-adjusted odds ratio 1·29, 1·08 to 1·55; P = 0·006). Distractions had no association with SSI. CONCLUSION More case-relevant communication was associated with fewer organ/space SSIs, and more case-irrelevant communication during wound closure was associated with incisional SSI.
New developments providing mechanistic insight into the impact of the microbiota on allergic disease
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The increase in allergic diseases over the past several decades is correlated with changes in the composition and diversity of the intestinal microbiota. Microbial-derived signals are critical for instructing the developing immune system and conversely, immune regulation can impact the microbiota. Perturbations in the microbiota composition may be especially important during early-life when the immune system is still developing, resulting in a critical window of opportunity for instructing the immune system. This review highlights recent studies investigating the role of the microbiome in susceptibility or development of allergic diseases with a focus on animal models that provide insight into the mechanisms and pathways involved. Identification of a causal link between reduced microbial diversity or altered microbial composition and increased susceptibility to immune-mediated diseases will hopefully pave the way for better preventive therapies.
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Homogeneously reprocessed combined GPS/GLONASS 1- and 3-day solutions from 1994 to 2013, generated by the Center for Orbit Determination in Europe (CODE) in the frame of the second reprocessing campaign REPRO-2 of the International GNSS Service, as well as GPS- and GLONASS-only 1- and 3-day solutions for the years 2009 to 2011 are analyzed to assess the impact of the arc length on the estimated Earth Orientation Parameters (EOP, namely polar motion and length of day), on the geocenter, and on the orbits. The conventional CODE 3-day solutions assume continuity of orbits, polar motion components, and of other parameters at the day boundaries. An experimental 3-day solution, which assumes continuity of the orbits, but independence from day to day for all other parameters, as well as a non-overlapping 3-day solution, is included into our analysis. The time series of EOPs, geocenter coordinates, and orbit misclosures, are analyzed. The long-arc solutions were found to be superior to the 1-day solutions: the RMS values of EOP and geocenter series are typically reduced between 10 and 40 %, except for the polar motion rates, where RMS reductions by factors of 2–3 with respect to the 1-day solutions are achieved for the overlapping and the non-overlapping 3-day solutions. In the low-frequency part of the spectrum, the reduction is even more important. The better performance of the orbits of 3-day solutions with respect to 1-day solutions is also confirmed by the validation with satellite laser ranging.