2,443 research outputs found
Relative Riemann-Zariski spaces
In this paper we study relative Riemann-Zariski spaces attached to a morphism
of schemes and generalizing the classical Riemann-Zariski space of a field. We
prove that similarly to the classical RZ spaces, the relative ones can be
described either as projective limits of schemes in the category of locally
ringed spaces or as certain spaces of valuations. We apply these spaces to
prove the following two new results: a strong version of stable modification
theorem for relative curves; a decomposition theorem which asserts that any
separated morphism between quasi-compact and quasi-separated schemes factors as
a composition of an affine morphism and a proper morphism. (In particular, we
obtain a new proof of Nagata's compactification theorem.)Comment: 30 pages, the final version, to appear in Israel J. of Mat
National Foreclosure Mitigation Counseling Program Evaluation: Final Report, Rounds 3 Through 5
The Urban Institute completed a four-year evaluation of Rounds 3 through 5 of the National Foreclosure Mitigation Counseling (NFMC) program. Using a representative NFMC sample of 137,000 loans and a comparison non-NFMC sample of 103,000 loans, the Urban Institute was able to employ robust statistical techniques to isolate the impact of NFMC counseling on loan performance through June 2013.The final evaluation of Rounds 3 through 5 conducted by Urban Institute indicates that the NFMC program continues to have positive effects for homeowners participating in the program Counseled homeowners were more likely to cure a serious delinquency or foreclosure with a modification or other type cure, stay current after obtaining a cure, and for NFMC clients who cured a serious delinquency, avoid foreclosure altogether
Calculation of Radiation from a Helically Cut Waveguide for a Gyrotron Mode Converter in the Quasi-Optical Approximation
Experimental observation of the effect of aftercavity interaction in a depressed collector gyrotron oscillator
This paper presents the experimental observation of the effect of an aftercavity interaction (ACI) in a depressed collector gyrotron oscillator. The gyrotron generates an output power of 1.5 MW at 110 GHz in 3 ??s pulses with a 96 kV and 40 A electron beam and has a single-stage depressed collector. The ACI arises from an unintended cyclotron resonant interaction between the microwave beam traveling out from the cavity and the gyrating electron beam. The interaction occurs in the uptaper of the launcher, immediately downstream from the cavity, where the magnetic field is slightly lower than its value in the cavity region. The ACI results in a reduction in efficiency since the electron beam tends to extract power from the wave. There is also a broadening of the spent beam energy profile, which reduces the effectiveness of the depressed collector and in turn limits the overall efficiency of a gyrotron. Measurements of the maximum depression voltage of the collector vs beam current at 96 kV are compared with simulations from the MAGY code [M. Botton, IEEE Trans. Plasma Sci. 26, 882 (1998)]. Excellent agreement is obtained between theory and experiment but only if the ACI is included. In the present experiment, it is estimated that the observed efficiency of 50% would have been about 60% in the absence of the ACI. These results verify the role of the ACI in reducing the efficiency of the gyrotron interaction.open151
Association between 5-Year clinical outcome in patients with nonmedically evacuated mild blast traumatic brain injury and clinical measures collected within 7 days postinjury in combat
Importance: Although previous work has examined clinical outcomes in combat-deployed veterans, questions remain regarding how symptoms evolve or resolve following mild blast traumatic brain injury (TBI) treated in theater and their association with long-term outcomes.
Objective: To characterize 5-year outcome in patients with nonmedically evacuated blast concussion compared with combat-deployed controls and understand what clinical measures collected acutely in theater are associated with 5-year outcome.
Design, Setting, and Participants: A prospective, longitudinal cohort study including 45 service members with mild blast TBI within 7 days of injury (mean 4 days) and 45 combat deployed nonconcussed controls was carried out. Enrollment occurred in Afghanistan at the point of injury with evaluation of 5-year outcome in the United States. The enrollment occurred from March to September 2012 with 5-year follow up completed from April 2017 to May 2018. Data analysis was completed from June to July 2018.
Exposures: Concussive blast TBI. All patients were treated in theater, and none required medical evacuation.
Main Outcomes and Measures: Clinical measures collected in theater included measures for concussion symptoms, posttraumatic stress disorder (PTSD) symptoms, depression symptoms, balance performance, combat exposure intensity, cognitive performance, and demographics. Five-year outcome evaluation included measures for global disability, neurobehavioral impairment, PTSD symptoms, depression symptoms, and 10 domains of cognitive function. Forward selection multivariate regression was used to determine predictors of 5-year outcome for global disability, neurobehavior impairment, PTSD, and cognitive function.
Results: Nonmedically evacuated patients with concussive blast injury (n = 45; 44 men, mean [SD] age, 31 [5] years) fared poorly at 5-year follow-up compared with combat-deployed controls (n = 45; 35 men; mean [SD] age, 34 [7] years) on global disability, neurobehavioral impairment, and psychiatric symptoms, whereas cognitive changes were unremarkable. Acute predictors of 5-year outcome consistently identified TBI diagnosis with contribution from acute concussion and mental health symptoms and select measures of cognitive performance depending on the model for 5-year global disability (area under the curve following bootstrap validation [AUCBV] = 0.79), neurobehavioral impairment (correlation following bootstrap validation [RBV] = 0.60), PTSD severity (RBV = 0.36), or cognitive performance (RBV = 0.34).
Conclusions and Relevance: Service members with concussive blast injuries fared poorly at 5-year outcome. The results support a more focused acute screening of mental health following TBI diagnosis as strong indicators of poor long-term outcome. This extends prior work examining outcome in patients with concussive blast injury to the larger nonmedically evacuated population
Flux networks in metabolic graphs
A metabolic model can be represented as bipartite graph comprising linked
reaction and metabolite nodes. Here it is shown how a network of conserved
fluxes can be assigned to the edges of such a graph by combining the reaction
fluxes with a conserved metabolite property such as molecular weight. A similar
flux network can be constructed by combining the primal and dual solutions to
the linear programming problem that typically arises in constraint-based
modelling. Such constructions may help with the visualisation of flux
distributions in complex metabolic networks. The analysis also explains the
strong correlation observed between metabolite shadow prices (the dual linear
programming variables) and conserved metabolite properties. The methods were
applied to recent metabolic models for Escherichia coli, Saccharomyces
cerevisiae, and Methanosarcina barkeri. Detailed results are reported for E.
coli; similar results were found for the other organisms.Comment: 9 pages, 4 figures, RevTeX 4.0, supplementary data available (excel
Understanding revenge pornography: public perceptions of revenge pornography and victim blaming
Purpose: The disclosure of private images with the intent of causing distress is often described as ‘revenge pornography’. In the UK, this newly legislated crime has received a high level of media attention following several high profile cases, however there is a paucity of research in this area.
Methods: 168 adults (UK general public) completed an online survey using a vignette approach. Views of the influence of perpetrator-victim relationship length and reason for termination were considered alongside perception of an offence, the necessity of police intervention, what extent revenge pornography creates psychological harm in victims, and victim blaming.
Findings: Perpetrator-victim relationship length and reason for relationship breakdown did not influence perceptions of victim blame. Participants believed that the situation described in the vignettes was likely to be an offence, and that police intervention is somewhat necessary. Participants believed that the scenario was ‘very likely’ to create fear, and ‘moderately likely’ to create psychological/mental harm in victims. In line with the literature relating to stalking and sexual assault, men blamed the victim significantly more than women. Furthermore, women rated police intervention significantly more necessary than men.
Implications: The public are recognising that revenge pornography is an offence, with consequences being fear and psychological harm, showing an awareness of the impact on victims. However, there are sex differences in the perceptions of revenge pornography and victim blame and this could be addressed by raising awareness of this crime. This research, which highlights that the public are aware of some of the harm caused, may encourage victims in coming forward to report such a crime.
Originality: There is a paucity of research into revenge pornography, and this study is one of the first in this area
Gaussian Optics Analysis Based on Phase Measurement in Evaluation of Coupling Mirrors at Matching-Optics-Unit
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