2,057 research outputs found
Searching for a Leptophilic Z' and a 3-3-1 symmetry at CLIC
We derive the discovery potential of a leptophilic Z', and a Z' rising from a
symmetry at the Compact Linear Collider
(CLIC), which is planned to host collisions with 3 TeV center-of-mass
energy. We perform an optimized selection cut strategy on the transverse
momentum, pseudorapidity, and invariant mass of the dileptons in order to
enhance the collider sensitivity. We find that CLIC can potentially reach a
signal of a ~TeV leptophilic Z' with less than of
integrated luminosity. As for the Z' belonging to a 3-3-1 symmetry, CLIC will
offer a complementary probe with the potential to impose ~TeV
with .Comment: 8 pages, 4 figure
Resultados del tratamiento quirúrgico del dolor lumbar con instrumentación diapasón
Se presenta un estudio sobre 23 pacientes con patologÃa lumbosacra tratados
quirúrgicamente mediante artrodesis e instrumentación vertebral transpedicular tipo diapasón.
El promedio de seguimiento ha sido de 25 meses (18-38). El dolor lumbar estaba relacionado en
10 casos con estenosis de canal, en 6 con espondilolistesis y en 7 con hernia discal y artrosis secundaria.
Todos fueron instrumentados por vÃa posterior mediante fijación transpedicular y artrodesados
posterolateralmente con injerto autólogo. Se consiguió una artrodesis sólida en un
96%. No se han presentado complicaciones preoperatorias. Ocho pacientes presentaron complicaciones
en el postoperatorio inmediato. Observamos un desplazamiento de barra y un desanclaje
del tornillo fuera del pedÃculo. Siguiendo los criterios de valoración de Henderson se ha conseguido
un 96% de excelentes y buenos resultados.A series of 23 patient with lumbosacral pathology, surgically treated by posterior
arthrodesis and vertebral diapason transpedicular fixation was retrospectively review. The average
follow-up period was 25 months (18-38). The diagnosis was spinal stenosis in 10 cases, spondylolisthesis
in 6, and disc herniation with secondary osteoartrhitis in 7 cases. Apart from transpedicular
fixation all cases underwent posterolateral fusion with autogenous bone graft. A solid arthrodesis
was achieved in a 96% of patients. There were no per-operative complication. Eight cases showed
complications in the immediate postoperative period. We observed displacement of a bar and
detachement of a screw out off the pedicle. According to Henderson's assessment criteria we obtained
96% of excellent and good results
Pleistocene cave hyenas in the Iberian Peninsula: New insights from los aprendices cave (Moncayo, Zaragoza)
A new Pleistocene paleontological site, Los Aprendices, located in the northwest-ern part of the Iberian Peninsula in the area of the Moncayo (Zaragoza) is presented. The layer with fossil remains has been dated by amino acid racemization to 143.8 ± 38.9 ka (earliest Late Pleistocene or latest Middle Pleistocene). Five mammal species have been identified in the assemblage: Crocuta spelaea (Goldfuss, 1823) Capra pyre-naica (Schinz, 1838), Lagomorpha indet, Arvicolidae indet and Galemys pyrenaicus (Geoffroy, 1811). The remains of C. spelaea represent a mostly complete skeleton in anatomical semi-connection. The hyena specimen represents the most complete skel-eton ever recovered in Iberia and one of the most complete remains in Europe. It has been compared anatomically and biometrically with both European cave hyenas and extant spotted hyenas. In addition, a taphonomic study has been carried out in order to understand the origin and preservation of these exceptional remains. The results sug-gest rapid burial with few scavenging modifications putatively produced by a medium sized carnivore. A review of the Pleistocene Iberian record of Crocuta spp. has been carried out, enabling us to establish one of the earliest records of C. spelaea in the recently discovered Los Aprendices cave, and also showing that the most extensive geographical distribution of this species occurred during the Late Pleistocene (MIS4-2)
A beam-beam monitoring detector for the MPD experiment at NICA
The Multi-Purpose Detector (MPD) is to be installed at the Nuclotron Ion
Collider fAcility (NICA) of the Joint Institute for Nuclear Research (JINR).
Its main goal is to study the phase diagram of the strongly interacting matter
produced in heavy-ion collisions. These studies, while providing insight into
the physics of heavy-ion collisions, are relevant for improving our
understanding of the evolution of the early Universe and the formation of
neutron stars. In order to extend the MPD trigger capabilities, we propose to
include a high granularity beam-beam monitoring detector (BE-BE) to provide a
level-0 trigger signal with an expected time resolution of 30 ps. This new
detector will improve the determination of the reaction plane by the MPD
experiment, a key measurement for flow studies that provides physics insight
into the early stages of the reaction. In this work, we use simulated Au+Au
collisions at NICA energies to show the potential of such a detector to
determine the event plane resolution, providing further redundancy to the
detectors originally considered for this purpose namely, the Fast Forward
Detector (FFD) and the Hadron Calorimeter (HCAL). We also show our results for
the time resolution studies of two prototype cells carried out at the T10 beam
line at the CERN PS complex.Comment: 16 pages, 12 figures. Updated to published version with added
comments and correction
Search for associations containing young stars (SACY) VIII. An updated census of spectroscopic binary systems showing hints of non-universal multiplicity among these associations
We seek to update the spectroscopy binary fraction of the SACY (Search for
Associations Containing Young stars) sample taking in consideration all
possible biases in our identification of binary candidates, such as activity
and rotation. Using high-resolution spectroscopic observations we have produced
1300 cross-correlation functions (CCFs) to disentangle the previously
mentioned sources of contamination. The radial velocity values obtained were
cross-matched with the literature and were used to revise and update the
spectroscopic binary (SB) fraction in each of the SACY association. In order to
better describe the CCF profile, we calculated a set of high-order
cross-correlation features to determine the origin of the variations in radial
velocities. We identified 68 SB candidates from our sample of 410 objects. Our
results hint that the youngest associations have a higher SB fraction.
Specifically, we found sensitivity-corrected SB fractions of for ~Cha , for TW Hya and
for ~Pictoris, in contrast with the five
oldest ( Myr) associations we have sampled which are
or lower. This result seems independent of the methodology used to asses
membership to the associations. The new CCF analysis, radial velocity estimates
and SB candidates are particularly relevant for membership revision of targets
in young stellar associations. These targets would be ideal candidates for
follow-up campaigns using high-resolution techniques in order to confirm
binarity, resolve the orbits, and ideally calculate dynamical masses.
Additionally, if the results on SB fraction in the youngest associations are
confirmed, it could hint of non-universal multiplicity among SACY associations.Comment: The paper has been accepted in A&
Mathematical modeling and forecasting of COVID-19: experience in Santiago de Cuba province
In the province of Santiago de Cuba, Cuba, the COVID-19 epidemic has a limited progression that shows an early small-number peak of infections. Most published mathematical models fit data with high numbers of confirmed cases. In contrast, small numbers of cases make it difficult to predict the course of the epidemic. We present two known models adapted to capture the noisy dynamics of COVID-19 in the Santiago de Cuba province. Parameters of both models were estimated using the approximate-Bayesian-computation framework with dedicated error laws. One parameter of each model was updated on key dates of travel restrictions. Both models approximately predicted the infection peak and the end of the COVID-19 epidemic in Santiago de Cuba. The first model predicted 57 reported cases and 16 unreported cases. Additionally, it estimated six initially exposed persons. The second model forecasted 51 confirmed cases at the end of the epidemic. In conclusion, an opportune epidemiological investigation, along with the low number of initially exposed individuals, might partly explain the favorable evolution of the COVID-19 epidemic in Santiago de Cuba. With the available data, the simplest model predicted the epidemic evolution with greater precision, and the more complex model helped to explain the epidemic phenomenology
An Adequately Robust Early TNF-α Response Is a Hallmark of Survival Following Trauma/Hemorrhage
Background: Trauma/hemorrhagic shock (T/HS) results in cytokine-mediated acute inflammation that is generally considered detrimental. Methodology/Principal Findings: Paradoxically, plasma levels of the early inflammatory cytokine TNF-α (but not IL-6, IL-10, or NO2-/NO3-) were significantly elevated within 6 h post-admission in 19 human trauma survivors vs. 4 non-survivors. Moreover, plasma TNF-α was inversely correlated with Marshall Score, an index of organ dysfunction, both in the 23 patients taken together and in the survivor cohort. Accordingly, we hypothesized that if an early, robust pro-inflammatory response were to be a marker of an appropriate response to injury, then individuals exhibiting such a response would be predisposed to survive. We tested this hypothesis in swine subjected to various experimental paradigms of T/HS. Twenty-three anesthetized pigs were subjected to T/HS (12 HS-only and 11 HS + Thoracotomy; mean arterial pressure of 30 mmHg for 45-90 min) along with surgery-only controls. Plasma obtained at pre-surgery, baseline post-surgery, beginning of HS, and every 15 min thereafter until 75 min (in the HS only group) or 90 min (in the HS + Thoracotomy group) was assayed for TNF-α, IL-6, IL-10, and NO2-/NO3-. Mean post-surgery±HS TNF-α levels were significantly higher in the survivors vs. non-survivors, while non-survivors exhibited no measurable change in TNF-α levels over the same interval. Conclusions/Significance: Contrary to the current dogma, survival in the setting of severe, acute T/HS appears to be associated with an immediate increase in serum TNF-α. It is currently unclear if this response was the cause of this protection, a marker of survival, or both. This abstract won a Young Investigator Travel Award at the SHOCK 2008 meeting in Cologne, Germany. © 2009 Namas et al
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