5,258 research outputs found
Maintaining Quantum Coherence in the Presence of Noise through State Monitoring
Unsharp POVM measurements allow the estimation and tracking of quantum
wavefunctions in real-time with minimal disruption of the dynamics. Here we
demonstrate that high fidelity state monitoring, and hence quantum control, is
possible even in the presence of classical dephasing and amplitude noise, by
simulating such measurements on a two-level system undergoing Rabi
oscillations. Finite estimation fidelity is found to persist indefinitely long
after the decoherence times set by the noise fields in the absence of
measurement.Comment: 5 pages, 4 figure
Conduction Channels of One-Atom Zinc Contacts
We have determined the transmission coefficients of atomic-sized Zn contacts
using a new type of breakjunction which contains a whisker as a central bridge.
We find that in the last conductance plateau the transport is unexpectedly
dominated by a well-transmitting single conduction channel. We explain the
experimental findings with the help of a tight-binding model which shows that
in an one-atom Zn contact the current proceeds through the 4s and 4p orbitals
of the central atom.Comment: revtex4, 5 pages, 5 figure
Altimetry, gravimetry, GPS and viscoelastic modeling data for the joint inversion for glacial isostatic adjustment in Antarctica (ESA STSE Project REGINA)
The poorly known correction for the ongoing deformation of the solid Earth caused by glacial isostatic adjustment (GIA) is a major uncertainty in determining the mass balance of the Antarctic ice sheet from measurements of satellite gravimetry and to a lesser extent satellite altimetry. In the past decade, much progress has been made in consistently modeling ice sheet and solid Earth interactions; however, forward-modeling solutions of GIA in Antarctica remain uncertain due to the sparsity of constraints on the ice sheet evolution, as well as the Earth's rheological properties. An alternative approach towards estimating GIA is the joint inversion of multiple satellite data – namely, satellite gravimetry, satellite altimetry and GPS, which reflect, with different sensitivities, trends in recent glacial changes and GIA. Crucial to the success of this approach is the accuracy of the space-geodetic data sets. Here, we present reprocessed rates of surface-ice elevation change (Envisat/Ice, Cloud,and land Elevation Satellite, ICESat; 2003–2009), gravity field change (Gravity Recovery and Climate Experiment, GRACE; 2003–2009) and bedrock uplift (GPS; 1995–2013). The data analysis is complemented by the forward modeling of viscoelastic response functions to disc load forcing, allowing us to relate GIA-induced surface displacements with gravity changes for different rheological parameters of the solid Earth. The data and modeling results presented here are available in the PANGAEA database (https://doi.org/10.1594/PANGAEA.875745). The data sets are the input streams for the joint inversion estimate of present-day ice-mass change and GIA, focusing on Antarctica. However, the methods, code and data provided in this paper can be used to solve other problems, such as volume balances of the Antarctic ice sheet, or can be applied to other geographical regions in the case of the viscoelastic response functions. This paper presents the first of two contributions summarizing the work carried out within a European Space Agency funded study: Regional glacial isostatic adjustment and CryoSat elevation rate corrections in Antarctica (REGINA)
Stochastic evolution of four species in cyclic competition
We study the stochastic evolution of four species in cyclic competition in a
well mixed environment. In systems composed of a finite number of particles
these simple interaction rules result in a rich variety of extinction
scenarios, from single species domination to coexistence between
non-interacting species. Using exact results and numerical simulations we
discuss the temporal evolution of the system for different values of , for
different values of the reaction rates, as well as for different initial
conditions. As expected, the stochastic evolution is found to closely follow
the mean-field result for large , with notable deviations appearing in
proximity of extinction events. Different ways of characterizing and predicting
extinction events are discussed.Comment: 19 pages, 6 figures, submitted to J. Stat. Mec
Current opinions regarding care of the mature pediatric urology patient
Introduction
With continued improvements in pediatric urology care of patients with complex congenital genitourinary conditions, many survive into adulthood. This fact has created a challenging situation of transitioning from pediatric to adult care. Establishing long-term follow-up with appropriate specialists is a critical part of a successful transition to adulthood for this population.
Objective
This study sought to elucidate current practices and opinions regarding the management of adult complex genitourinary patients by pediatric urologists, in order to determine if a consensus for adult care exists.
Study design
An anonymous, 15-question online survey was created to address practice patterns and opinions regarding the transition of care of complex genitourinary patients. An invitation to participate was distributed via email to 200 pediatric urologists who were members of the American Urological Association. Complex genitourinary patients were defined broadly as those with a history of: spina bifida, bladder exstrophy, cloacal exstrophy, cloacal anomalies, posterior urethral valves or disorders of sex development. Fisher's exact test was used for analysis.
Results
The response rate was 31.0% (62/200). Two-thirds (67.7%) cared for adults with complex genitourinary conditions. Overall, 51.6% of pediatric urologists felt that general urologists best follow adult patients, but only 6.5% recommended this for patients with prior complex genitourinary reconstruction (P < 0.001). Instead, the majority (80.6%) felt that a pediatric or adult urologist with an interest and training in adolescent/transitional urology who routinely performs such procedures would provide optimal care. Follow-up by a primary care physician alone was not recommended. Recommendations did not change if patients had developmental delay or lived independently (P = 0.47 and P = 0.72, respectively). Overall, 69.4% would refer mature complex genitourinary patients to a urologist with interest and training in adolescent/transitional urology, if one was available. However, only 45.2% had such an individual available in their practice (P < 0.001).
Discussion
In the present study, the opinions of pediatric urologists regarding optimal providers of long-term follow-up for mature complex genitourinary patients were presented. While the results may not represent the views of the entire pediatric urology community, responses from motivated individuals with a particular interest in transition care may be especially valuable. Although the present study did not outline a mechanism for improving transitional care, it offered valuable information on prevailing opinions in this area. Finally, the opinions of mostly North American Pediatric Urologists were presented, which may not apply to other healthcare settings.
Conclusions
Pediatric urologists appeared to be virtually unanimous in recommending that urologists provide the most appropriate long-term follow-up of patients with congenital genitourinary conditions. Specifically, 80% recommended that patients with prior complex surgical reconstruction be followed by a urologist with specific interest, training and experience in the area of transitional urology. The data suggest that this may be an unmet need of these specialists and may signify the need for specific training in the care of such patients
Pasado, presente y futuro del búfalo en Argentina
El búfalo comenzó a ser introducido al paÃs a comienzo el siglo XX, mediante la importación razas Mediterránea, Murrah y Jafarabadi. En la actualidad la población bubalina alcanzó las de 87.711 cabezas y se encuentran distribuidas en 20 de las 23 provincias que componen el territorio nacional. El 80 % de la población de búfalos se encuentran en el nordeste argentino. Siendo las provincias de Formosa y Corrientes las que cuentan con la mayores poblaciones bubalinas. Existen en el paÃs 8 millones de hectáreas aptas para soportar una carga de 4 millones de búfalos.The buffalo began to be introduced to the country in the early twentieth century, by importing Mediterranean, Murrah and Jafarabadi breeds. Today buffalo population reached 87.711 heads, which are distributed in 20 out of the 23 provinces that conforms the country. The 80% of the population of buffaloes is found in northeastern region, being the provinces of Formosa and Corrientes those with the largest buffalo population. The country has 8 million hectares suitable to withstand a load of 4 million buffaloes.Fil: Crudeli, G. A.. Universidad Nacional del Nordeste. Facultad de Cs.veterinarias; ArgentinaFil: Patiño, E. M.. Universidad Nacional del Nordeste. Facultad de Cs.veterinarias; ArgentinaFil: Maldonado Vargas, P.. Universidad Nacional del Nordeste. Facultad de Cs.veterinarias; ArgentinaFil: Konrad, José Luis. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad Nacional del Nordeste. Facultad de Cs.veterinarias; Argentin
Corrigendum: Scaling of Optogenetically Evoked Signaling in a Higher-Order Corticocortical Pathway in the Anesthetized Mouse
Rosetta Brains: A Strategy for Molecularly-Annotated Connectomics
We propose a neural connectomics strategy called Fluorescent In-Situ
Sequencing of Barcoded Individual Neuronal Connections (FISSEQ-BOINC),
leveraging fluorescent in situ nucleic acid sequencing in fixed tissue
(FISSEQ). FISSEQ-BOINC exhibits different properties from BOINC, which relies
on bulk nucleic acid sequencing. FISSEQ-BOINC could become a scalable approach
for mapping whole-mammalian-brain connectomes with rich molecular annotations
Risk factors for mortality-morbidity after emergency-urgent colorectal surgery
Background: The aim of this study was to assess the risk factors associated with mortality and morbidity following emergency or urgent colorectal surgery. Materials and methods: All data regarding the 462 patients who underwent emergency colonic resection in our institution between November 2002 and December 2007 were prospectively entered into a computerized database. Results: The median age of patients was 73 (range 17-98)years. The most common indications for surgery were: 171 adenocarcinomas (37%), 129 complicated diverticulitis (28%), and 35 colonic ischemia (7.5%). Overall mortality and morbidity rates were 14% and 36%, respectively. In multivariate analysis, the only parameter significantly associated with postoperative mortality was blood loss >500cm3 (odds ratio (OR) = 3.33, 95% confidence interval (CI) 1.63-6.82, p = 0.001). There were three parameters which correlated with postoperative morbidity: ASA score ≥3 (OR = 2.9, 95% CI 1.9-4.5, p < 0.001), colonic ischemia (OR = 3.4, 95% CI 1.4-7.7, p = 0.006), and stoma creation (OR = 2.2, 95% CI 1.4-3.4, p = 0.0003). Conclusions: The main risk factors for postoperative morbidity and mortality following emergency colorectal surgery are related to: (1) patients' ASA score, (2) colonic ischemia, and (3) perioperative bleeding. These variables should be considered in the elaboration of future scoring systems to predict outcome of emergency colorectal surger
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