310 research outputs found
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A comparison of in-sample forecasting methods
In-sample forecasting is a recent continuous modification of well-known forecasting methods based on aggregated data. These aggregated methods are known as age-cohort methods in demography, economics, epidemiology and sociology and as chain ladder in non-life insurance. Data is organized in a two-way table with age and cohort as indices, but without measures of exposure. It has recently been established that such structured forecasting methods based on aggregated data can be interpreted as structured histogram estimators. Continuous in-sample forecasting transfers these classical forecasting models into a modern statistical world including smoothing methodology that is more efficient than smoothing via histograms. All in-sample forecasting estimators are collected and their performance is compared via a finite sample simulation study. All methods are extended via multiplicative bias correction. Asymptotic theory is being developed for the histogram-type method of sieves and for the multiplicatively corrected estimators. The multiplicative bias corrected estimators improve all other known in-sample forecasters in the simulation study. The density projection approach seems to have the best performance with forecasting based on survival densities being the runner-up
Standing osteosynthesis of an accessory carpal bone fracture in a Warmblood mare with a 6âhole 3.5 talonavicular fusion plate and 3.5âmm screws
A 9-year-old Warmblood, high-level showjumping mare sustained an acute, closed, vertical, comminuted fracture of the left accessory carpal bone (ACB) during a fall. The fracture was repaired under standing sedation and local anaesthesia, using a 6-hole APTUSÂź 3.5 TFP and 5âĂâ3.5-mm self-tapping TriLock© screws. The mare recovered from surgery without complications. Upon follow-up examination 9âmonths post-operatively the mare was sound in all gaits and back to full athletic activity. The ACB fracture had completely healed. The displaced dorsoproximal fracture fragment was in a stationary position and there was evidence of mild nonprogressive osteoarthritis of the antebrachiocarpal joint
Interplay of coarsening, aging, and stress hardening impacting the creep behavior of a colloidal gel
We explore the dynamical and mechanical characteristics of an evolving gel in diffusing wave spectroscopy (DWS) and rheometry, aiming to assess how the gel evolution impacts the creep response of the system. Our gel is formed by inducing the aggregation of thermosensitive colloids by a variation in temperature. We find experimental evidence that the long time evolution of this gel is due to two distinct processes: A coarsening process that involves the incorporation of mobile particles into the network structure and an aging process that triggers intermittent rearrangement events. While coarsening is the main process governing the evolution of the elastic properties of the gel, aging is the process determining structural relaxation. The combination of both processes in addition to stress hardening governs the creep behavior of the gel, a creep behavior that is determined by three distinct contributions: an instantaneous elastic, a delayed elastic, and a loss contribution. The systematic investigation of these contributions in recovery experiments provides evidence that losses and delayed elastic storage have a common origin, both being due to intermittent local structural relaxation events
Systemdynamische Betrachtungen zur Sturzdynamik und -prophylaxe: Entwicklung eines deterministischen Modells
Zusammenfassung: Hintergrund: StĂŒrze Ă€lterer Personen ist derzeit eine groĂe Public-Health-Herausforderung. Da Instrumente zur Erkennung sturzgefĂ€hrdeter Personen wenig genaue Vorhersagen machen, wurde ein deterministisches systemdynamisches Modell der Sturzdynamik entwickelt. Methoden: Unter Verwendung bekannter Sturzrisikofaktoren, quantitativer Forschungsergebnisse und AbschĂ€tzungen, Ursachen- und Wirkbeziehungen wurde ein deterministisches Modell simuliert. Ergebnisse: Grundvoraussetzungen fĂŒr StĂŒrze sind Bewegung oder Bewegungsabsichten ("MobilitĂ€t im Alltag"), ein Sturzrisiko und ein Ungleichgewicht zwischen Gehanforderungen und GehfĂ€higkeit. Kraft, Koordination und Gleichgewicht wurden als SpeichergröĂen definiert und Ursache-Wirkungs-ZusammenhĂ€nge ins Modell integriert. Zahlreiche andere bekannte Sturzrisikofaktoren wurden ins Modell aufgenommen und quantifiziert. Die Simulation einer Fixierung zeigte, dass die Sturzwahrscheinlichkeit unmittelbar nach der Fixierung erhöht ist. Das Modell zeigt in der Simulation systemdynamische Aspekte wie Verzögerung, RĂŒckkoppelung und Nicht-LinearitĂ€t. Schlussfolgerung: Mit Hilfe der Systemdynamik konnte ein deterministisches systemdynamisches Modell der Sturzdynamik und -prophylaxe fĂŒr eine Pflegeheimpopulation unter Einbeziehung bekannter Sturzrisikofaktoren entwickelt werden, das von Praktikern als plausibel beurteilt wird und das "richtungssicher" reagier
Traffic accident-related injuries in horses
Horses involved in road traffic accidents (RTAs) are commonly presented to veterinarians with varying types of injuries. The aim of this study was describe the pattern and severity of traffic accident-related injuries in horses in a single hospital population. Medical records of horses either hit by a motorized vehicle or involved in RTAs whilst being transported from 1993 to 2015 were retrospectively reviewed and the following data was extracted: Signalement, hospitalisation time, month in which the accident happened, cause of the accident, place of the accident and type of vehicle hitting the horse. Further the different body sites injured (head, neck, breast, fore limb, abdomen, back and spine, pelvis and ileosacral region, hind limb, tail and genital region), the type of injury (wounds, musculoskeletal lesions and internal lesions) and the presence of neurological signs were retrieved from the medical records. 34 horses hit by motorized vehicles and 13 horses involved in RTAs whilst being transported were included in the study. Most of the accidents where horses were hit by motorized vehicles occurred during December (14.7%) and October (14.7%), horses were most commonly hit by cars (85.3%) and the
majority of accidents occurred on main roads (26.5%). In 29.4% of the cases, horses had escaped from their paddock and then collided with a motorized vehicle. Most of the accidents with horses involved in RTAs whilst being transported occurred during April (30.8%) and June (23.1%). In 76.9% of the cases the accident happened on a freeway. In the horses hit by motorized vehicles the proximal hind limbs were the body site most commonly affected (44.1%), followed by the proximal front limbs (38.2%) and the head (32.4%). When horses were involved in RTAs whilst being transported the proximal fore limbs (61.5%), the proximal hind limbs (53.8%) and the distal hind limbs, back and head (38.5% each) were the most common injured body sites. Wounds were the most common type of injury in both groups(85.3% hit by motorized vehicle, 76.9% transported ones). In horses hit by a motorized vehicle 35.3% suffered from fractures, in 20.6% a synovial structure was involved and in 5.9% a tendon lesion was present. 14.7% suffered from internal lesions and 14.7% showed neurologic symptoms (40% peripheral, 60% central neurologic deficits). On the other hand, in horses involved in a RTA whilst being transported 30.8% suffered from fractures. There were no synovial structures injured and no tendon injuries were present. Furthermore there were no internal lesions present and only one horse involved in a RTA showed central neurologic symptoms. Injuries of horses being hit by a motorized vehicle were more severe than when horses were protected by a trailer and involved in an RTA whilst being transported. The study has been able to identify the different injury types of traffic accident-related injuries in horses. Awareness of the nature of these injuries is important, to avoid underestimation of their severity
Synaptic Integration of Adult-Born Hippocampal Neurons Is Locally Controlled by Astrocytes.
Adult neurogenesis is regulated by the neurogenic niche, through mechanisms that remain poorly defined. Here, we investigated whether niche-constituting astrocytes influence the maturation of adult-born hippocampal neurons using two independent transgenic approaches to block vesicular release from astrocytes. In these models, adult-born neurons but not mature neurons showed reduced glutamatergic synaptic input and dendritic spine density that was accompanied with lower functional integration and cell survival. By taking advantage of the mosaic expression of transgenes in astrocytes, we found that spine density was reduced exclusively in segments intersecting blocked astrocytes, revealing an extrinsic, local control of spine formation. Defects in NMDA receptor (NMDAR)-mediated synaptic transmission and dendrite maturation were partially restored by exogenous D-serine, whose extracellular level was decreased in transgenic models. Together, these results reveal a critical role for adult astrocytes in local dendritic spine maturation, which is necessary for the NMDAR-dependent functional integration of newborn neurons
The Physics of Heavy Flavours at SuperB
This is a review of the SuperB project, covering the accelerator, detector,
and highlights of the broad physics programme. SuperB is a flavour factory
capable of performing precision measurements and searches for rare and
forbidden decays of , , and
particles. These results can be used to test fundamental symmetries and
expectations of the Standard Model, and to constrain many different
hypothesised types of new physics. In some cases these measurements can be used
to place constraints on the existence of light dark matter and light Higgs
particles with masses below . The potential impact of the
measurements that will be made by SuperB on the field of high energy physics is
also discussed in the context of data taken at both high energy in the region
around the \Upsilon({\mathrm{4S}})$, and near charm threshold.Comment: 49 pages, topical review submitted to J. Phys
Observation of Bs->Ds(*)+Ds(*)- using e+e- collisions and a determination of the Bs-Bsbar width difference \Delta\Gamma_s
We have made the first observation of Bs->Ds(*)+Ds(*)- decays using 23.6 fb-1
of data recorded by the Belle experiment running on the Upsilon(5S) resonance.
The branching fractions are measured to be B(B^0_s\ra D^+_s D^-_s) =
(1.0\,^{+0.4}_{-0.3}\,^{+0.3}_{-0.2})%, B(B^0_s\ra D^{*\pm}_s D^{\mp}_s) =
(2.8\,^{+0.8}_{-0.7}\,\pm 0.7)%, and B(B^0_s\ra D^{*+}_s D^{*-}_s) =
(3.1\,^{+1.2}_{-1.0}\,\pm 0.8)%; the sum is B(B^0_s\ra D^{(*)+}_s D^{(*)-}_s) =
(6.9\,^{+1.5}_{-1.3}\,\pm 1.9)%. Assuming Bs->Ds(*)+Ds(*)- saturates decays to
CP-even final states, the branching fraction determines the ratio
\Delta\Gamma_s/cos(\phi), where \Delta\Gamma_s is the difference in widths
between the two Bs-Bsbar mass eigenstates, and \phi is a CP-violating weak
phase. Taking CP violation to be negligibly small, we obtain
\Delta\Gamma_s/\Gamma_s =
0.147^{+0.036}_{-0.030}(stat.)^{+0.044}_{-0.042}(syst.), where \Gamma_s is the
mean decay width.Comment: 13 pages, 2 figures, 2 tables. v2: text added for clarification,
version published in Phys. Rev. Letter
Search for CP violation in the decays and
We have searched for CP violation in the charmed meson decays and using 673 fb of data
collected with the Belle detector at the KEKB asymmetric-energy
collider. No evidence for CP violation is observed. We report the most
sensitive CP asymmetry measurements to date for these decays: , , , and , where the first uncertainties are statistical and
the second are systematic
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