The realization of all-semiconductor epitaxially regrown photonic crystal (PC) surface-emitting lasers is reported. PC coupling strengths, band structure, optimization of epitaxial regrowth, and ...operating characteristics are discussed. Room temperature operation allows agreement between theoretical and experimental band structure to be confirmed.
Spatial and temporal characteristics of heavy precipitation events over Canada (excluding the high Arctic) are examined for the period 1900–98. In southern Canada, about 71% of total precipitation ...comes from rainfall events. In northern Canada, more than 50% of total precipitation comes from snowfall events. Heavy rainfall and snowfall events are thus defined for each season and station separately by identifying a threshold value that is exceeded by an average of three events per year. Annual and seasonal time series of heavy event frequency are then obtained by counting the number of exceedances per year. Characteristics of the intensity of heavy precipitation events are investigated examining the 90th percentiles of daily precipitation, the annual maximum daily value, and the 20-yr return values. It was found that decadal variability is the dominant feature in both the frequency and the intensity of extreme precipitation events over the country. For the country as a whole, there appear to be no identifiable trends in extreme precipitation (either frequency or intensity) during the last century. The observed increase in precipitation totals in the twentieth century was mainly due to increase in the number of small to moderate events.
Stations with coherent temporal variability in the frequency of heavy precipitation events are grouped by cluster analysis and examined on a regional basis. Results show stations belonging to the same group are generally located in a continuous region, indicating that the temporal distribution of the number of events is spatially coherent. It is also found that heavy snowfall events are more spatially coherent than heavy rainfall events. Indices representing temporal variations of regional heavy precipitation display strong interdecadal variability with limited evidence of long-term trends. They vary markedly depending on the precipitation type, season, and region. Spring heavy rainfall events over eastern Canada have shown an increasing trend superimposed on the strong decadal variability. However, heavy rainfall events in other seasons/regions are generally not associated with any trends or decadal variability. The number of heavy snowfall events in southern Canada shows an upward trend from the beginning of the twentieth century until the late 1950s to 1970s, followed by a downward trend to the present. In the last 50 yr, heavy snowfall events in northern Canada have been increasing with marked decadal variation.
The majority of stations have a significant positive correlation between the total amount of snowfall contributed by heavy events versus that contributed from nonheavy events. The relationship is strongest over western Canada. On the other hand, relatively few (<20%) stations had a significant correlation between total rainfall in heavy events and nonheavy events. These results suggest that the amount of precipitation falling in heavy and nonheavy events increases or decreases coherently for snow, but not for rain.
Reduced-representation sequencing methods have wide utility in conservation genetics of non-model species. Several methods are now available that reduce genome complexity to examine a wide range of ...markers in a large number of individuals. We produced two datasets collected using different laboratory techniques, comprising a common set of samples from the greater bilby (
Macrotis lagotis
). We examined the impact of differing data filtering thresholds on downstream population inferences. We found that choice of restriction enzyme and data filtering thresholds, especially the rate of allowable missing data, impacted our ability to detect population structure. Estimates of F
ST
were robust to alterations in laboratory and bioinformatic protocols while principal coordinates and STRUCTURE analyses showed variation according to the number of loci and percent missing data. We advise researchers using reduced-representation sequencing in conservation projects to examine a range of data thresholds, and follow these through to downstream population inferences. Multiple measures of population differentiation should be used in order to fully understand how data filtering thresholds influence the final dataset, paying particular attention to the impact of allowable missing data. Our results indicate that failure to follow these checks could impact conclusions drawn, and conservation management decisions made.
Robotic-assisted pancreatectomy continues to proliferate despite limited evidence supporting its benefits from the patient's perspective. We compared patient-reported outcomes (PROs) between patients ...undergoing robotic and open pancreatectomies.
PROs, measured with the FACT-Hep, FACT-G, and HCS, were assessed in the immediate postoperative (i.e., preoperative to discharge) and recovery (i.e., discharge to three months postoperative) periods. Linear mixed models estimated the association of operative approach on PROs. Minimally important differences (MIDs) were also considered.
Among 139 patients, 105 (75.5%) underwent robotic pancreatectomies. Compared to those who underwent open operations, those who underwent robotic operations experienced worse FACT-Hep scores that were both statistically and clinically significant (mean difference MD 8.6 points, 95% CI 1.0–16.3). Declines in FACT-G (MD 4.3, 95% CI −1.0 to 9.6) and HCS (MD 4.3, 95% CI 0.8–7.9) scores appeared to contribute equally in both operative approaches to the decline in total FACT-Hep score. Patients who underwent robotic versus open operations both statistically and clinically significantly improved due to improvements in HCS (MD 6.1, 95% CI 2.3–9.9) but not in FACT-G (MD 1.2, 95% CI − 5.1-7.4).
The robotic approach to pancreas surgery might offer, from the patient's perspective, greater improvement in symptoms over the open approach by three months postoperatively.
The Fifth Data Release of the Sloan Digital Sky Survey Adelman-McCarthy, Jennifer K; Allam, Sahar S; Anderson, Kurt S. J ...
The Astrophysical journal. Supplement series,
10/2007, Letnik:
172, Številka:
2
Journal Article
Recenzirano
Odprti dostop
This paper describes the Fifth Data Release (DR5) of the Sloan Digital Sky Survey (SDSS). DR5 includes all survey quality data taken through 2005 June and represents the completion of the SDSS-I ...project (whose successor, SDSS-II, will continue through mid-2008). It includes five-band photometric data for 217 million objects selected over 8000 deg super(2) and 1,048,960 spectra of galaxies, quasars, and stars selected from 5713 deg super(2) of that imaging data. These numbers represent a roughly 20% increment over those of the Fourth Data Release; all the data from previous data releases are included in the present release. In addition to "standard" SDSS observations, DR5 includes repeat scans of the southern equatorial stripe, imaging scans across M31 and the core of the Perseus Cluster of galaxies, and the first spectroscopic data from SEGUE, a survey to explore the kinematics and chemical evolution of the Galaxy. The catalog database incorporates several new features, including photometric redshifts of galaxies, tables of matched objects in overlap regions of the imaging survey, and tools that allow precise computations of survey geometry for statistical investigations.
Immunoglobulin A nephropathy (IgAN) is a leading cause of chronic kidney disease, frequently associated with hypertension and renal inflammation. ω-3 fatty acids eicosapentaenoic acid (EPA) and ...docosahexaenoic acid (DHA) in fish oil (FO) improve kidney function in animal models, but have inconsistent metabolic effects in humans. Oxylipin profiles in serum from IgAN patients supplemented with either FO or corn oil (CO) placebo were analyzed by liquid chromatography coupled to tandem mass spectrometry. EPA cyclooxygenase and lipoxygenase metabolites, and EPA and DHA epoxides and diols were increased in response to FO supplementation, as were total epoxides and epoxide/diol ratios. Several of these metabolites were drivers of separation as assessed by multivariate analysis of FO patients pre- versus post-supplementation, including 17,18-dihydroxyeicosatrienoic acid, prostaglandin D
3
, prostagalandin E
3
, Resolvin E1, 12-hydroxyeicosapentaenoic acid, and 10(11)-epoxydocosapentaenoic acid. In patients whose proteinuria improved, plasma total oxylipins as well as several hydroxyoctadecadienoic acids, hydroxyeicosatetraenoic acids, and leukotriene B
4
metabolites were among the metabolites that were significantly lower than in patients whose proteinuria either did not improve or worsened. These data support the involvement of oxylipins in the inflammatory component of IgAN as well as the potential use of oxylipin profiles as biomarkers and for assessing responsiveness to ω-3 fatty acid supplementation in IgAN patients.
An Optimizing Performance through Intrinsic Motivation and Attention for Learning theory-based motor learning intervention delivering autonomy support and enhanced expectancies (EE) shows promise for ...reducing cognitive-motor dual-task costs, or the relative difference in primary task performance when completed with and without a secondary cognitive task, that facilitate adaptive injury-resistant movement response. The current pilot study sought to determine the effectiveness of an autonomy support versus an EE-enhanced virtual reality motor learning intervention to reduce dual-task costs during single-leg balance.
Within-subjects 3 × 3 trial.
Twenty-one male and 24 female participants, between the ages of 18 and 30 years, with no history of concussion, vertigo, lower-extremity surgery, or lower-extremity injuries the previous 6 months, were recruited for training sessions on consecutive days. Training consisted of 5 × 8 single-leg squats on each leg, during which all participants mimicked an avatar through virtual reality goggles. The autonomy support group chose an avatar color, and the EE group received positive kinematic biofeedback. Baseline, immediate, and delayed retention testing consisted of single-leg balancing under single- and dual-task conditions. Mixed-model analysis of variances compared dual-task costs for center of pressure velocity and SD between groups on each limb.
On the right side, dual-task costs for anterior-posterior center of pressure mean and SD were reduced in the EE group (mean Δ = -51.40, Cohen d = 0.80 and SD Δ = -66.00%, Cohen d = 0.88) compared with the control group (mean Δ = -22.09, Cohen d = 0.33 and SD Δ = -36.10%, Cohen d = 0.68) from baseline to immediate retention.
These findings indicate that EE strategies that can be easily implemented in a clinic or sport setting may be superior to task-irrelevant AS approaches for influencing injury-resistant movement adaptations.
General surgery residents should be proficiently trained in robotic surgery. However, there is currently no standardized robotic training curriculum. We aimed to evaluate two approaches to a robotic ...curriculum and how implementing a virtual reality (VR) simulation curriculum improves trainee robotic performance. From 2019 to 2022, two models of a robotic training curriculum were examined: an in-unit rotation (IUR) and a 2-week curriculum (2WR). The VR curriculum was completed using the
da Vinci® Skill Simulator.
The curriculum used a pre/post-test design. Residents completed a pre-test that consisted of 4 VR exercises (graded 0–100%) and 3 inanimate box trainer exercises (graded using modified Objective Structured Assessment of Technical Skills). Then, residents completed a VR curriculum of 23 modules. Following the curriculum, residents were given a post-test with the same pre-test exercises. Time necessary to complete the curriculum and compliance were recorded. Of the 11 residents who participated in the IUR, 4 completed the VR curriculum. Comparatively, 100% (
n
= 23) of residents in the 2WR completed the curriculum. Average time to complete the VR curriculum was 3.8 h. After completion of the 2WR curriculum, resident performance improved from pre-test to post-test: VR test scores increased (160% vs 223%,
p
< 0.001), OSATS scores increased (15.0 vs 21.0,
p
< 0.001), and time to complete inanimate exercises decreased (1083 vs 756 s,
p
= 0.001). Residents who mastered all modules had higher post-test VR scores (241% vs 214%,
p
= 0.024). General surgery residents demonstrated improved compliance with the 2WR. The VR curriculum improved resident robotic performance in both virtual and inanimate domains.
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