3,914 research outputs found
Prevalence Rates of Mental Disorders in Chilean Prisons
PMCID: PMC371883
The stellar and sub-stellar IMF of simple and composite populations
The current knowledge on the stellar IMF is documented. It appears to become
top-heavy when the star-formation rate density surpasses about 0.1Msun/(yr
pc^3) on a pc scale and it may become increasingly bottom-heavy with increasing
metallicity and in increasingly massive early-type galaxies. It declines quite
steeply below about 0.07Msun with brown dwarfs (BDs) and very low mass stars
having their own IMF. The most massive star of mass mmax formed in an embedded
cluster with stellar mass Mecl correlates strongly with Mecl being a result of
gravitation-driven but resource-limited growth and fragmentation induced
starvation. There is no convincing evidence whatsoever that massive stars do
form in isolation. Various methods of discretising a stellar population are
introduced: optimal sampling leads to a mass distribution that perfectly
represents the exact form of the desired IMF and the mmax-to-Mecl relation,
while random sampling results in statistical variations of the shape of the
IMF. The observed mmax-to-Mecl correlation and the small spread of IMF
power-law indices together suggest that optimally sampling the IMF may be the
more realistic description of star formation than random sampling from a
universal IMF with a constant upper mass limit. Composite populations on galaxy
scales, which are formed from many pc scale star formation events, need to be
described by the integrated galactic IMF. This IGIMF varies systematically from
top-light to top-heavy in dependence of galaxy type and star formation rate,
with dramatic implications for theories of galaxy formation and evolution.Comment: 167 pages, 37 figures, 3 tables, published in Stellar Systems and
Galactic Structure, Vol.5, Springer. This revised version is consistent with
the published version and includes additional references and minor additions
to the text as well as a recomputed Table 1. ISBN 978-90-481-8817-
Tisotumab Vedotin in Combination With Carboplatin, Pembrolizumab, or Bevacizumab in Recurrent or Metastatic Cervical Cancer: Results From the innovaTV 205/GOG-3024/ENGOT-cx8 Study.
PURPOSE: Tissue factor is highly expressed in cervical carcinoma and can be targeted by tisotumab vedotin (TV), an antibody-drug conjugate. This phase Ib/II study evaluated TV in combination with bevacizumab, pembrolizumab, or carboplatin for recurrent or metastatic cervical cancer (r/mCC). METHODS: This open-label, multicenter study (ClinicalTrials.gov identifier: NCT03786081) included dose-escalation arms that assessed dose-limiting toxicities (DLTs) and identified the recommended phase II dose (RP2D) of TV in combination with bevacizumab (arm A), pembrolizumab (arm B), or carboplatin (arm C). The dose-expansion arms evaluated TV antitumor activity and safety at RP2D in combination with carboplatin as first-line (1L) treatment (arm D) or with pembrolizumab as 1L (arm E) or second-/third-line (2L/3L) treatment (arm F). The primary end point of dose expansion was objective response rate (ORR). RESULTS: A total of 142 patients were enrolled. In dose escalation (n = 41), no DLTs were observed; the RP2D was TV 2 mg/kg plus bevacizumab 15 mg/kg on day 1 once every 3 weeks, pembrolizumab 200 mg on day 1 once every 3 weeks, or carboplatin AUC 5 on day 1 once every 3 weeks. In dose expansion (n = 101), the ORR was 54.5% (n/N, 18/33; 95% CI, 36.4 to 71.9) with 1L TV + carboplatin (arm D), 40.6% (n/N, 13/32; 95% CI, 23.7 to 59.4) with 1L TV + pembrolizumab (arm E), and 35.3% (12/34; 19.7 to 53.5) with 2L/3L TV + pembrolizumab (arm F). The median duration of response was 8.6 months, not reached, and 14.1 months, in arms D, E, and F, respectively. Grade ≥3 adverse events (≥15%) were anemia, diarrhea, nausea, and thrombocytopenia in arm D and anemia in arm F (none ≥15%, arm E). CONCLUSION: TV in combination with bevacizumab, carboplatin, or pembrolizumab demonstrated manageable safety and encouraging antitumor activity in treatment-naive and previously treated r/mCC
Weekly dose-dense chemotherapy in first-line epithelial ovarian, fallopian tube, or primary peritoneal cancer treatment (ICON8): overall survival results from an open-label, randomised, controlled, phase 3 trial
BACKGROUND: Standard-of-care first-line chemotherapy for epithelial ovarian cancer is carboplatin and paclitaxel administered once every 3 weeks. The JGOG 3016 trial reported significant improvement in progression-free and overall survival with dose-dense weekly paclitaxel and 3-weekly (ie, once every 3 weeks) carboplatin. However, this benefit was not observed in the previously reported progression-free survival results of ICON8. Here, we present the final coprimary outcomes of overall survival and updated progression-free survival analyses of ICON8. METHODS: In this open-label, randomised, controlled, phase 3 trial (ICON8), women aged 18 years or older with newly diagnosed stage IC-IV epithelial ovarian, primary peritoneal, or fallopian tube carcinoma (here collectively termed ovarian cancer, as defined by International Federation of Gynecology and Obstetrics [FIGO] 1988 criteria) and an Eastern Cooperative Oncology Group performance status of 0-2 were recruited from 117 hospitals with oncology departments in the UK, Australia and New Zealand, Mexico, South Korea, and Ireland. Patients could enter the trial after immediate primary surgery (IPS) or with planned delayed primary surgery (DPS) during chemotherapy, or could have no planned surgery. Participants were randomly assigned (1:1:1), using the Medical Research Council Clinical Trials Unit at University College London randomisation line with stratification by Gynecologic Cancer Intergroup group, FIGO disease stage, and outcome and timing of surgery, to either 3-weekly carboplatin area under the curve (AUC)5 or AUC6 and 3-weekly paclitaxel 175 mg/m2 (control; group 1), 3-weekly carboplatin AUC5 or AUC6 and weekly paclitaxel 80 mg/m2 (group 2), or weekly carboplatin AUC2 and weekly paclitaxel 80 mg/m2 (group 3), all administered via intravenous infusion for a total of six 21-day cycles. Coprimary outcomes were progression-free survival and overall survival, with comparisons done between group 2 and group 1, and group 3 and group 1, in the intention-to-treat population. Safety was assessed in all patients who started at least one chemotherapy cycle. The trial is registered on ClinicalTrials.gov, NCT01654146, and ISRCTN registry, ISRCTN10356387, and is closed to accrual. FINDINGS: Between June 6, 2011, and Nov 28, 2014, 1566 patients were randomly assigned to group 1 (n=522), group 2 (n=523), or group 3 (n=521). The median age was 62 years (IQR 54-68), 1073 (69%) of 1566 patients had high-grade serous carcinoma, 1119 (71%) had stage IIIC-IV disease, and 745 (48%) had IPS. As of data cutoff (March 31, 2020), with a median follow-up of 69 months (IQR 61-75), no significant difference in overall survival was observed in either comparison: median overall survival of 47·4 months (95% CI 43·1-54·8) in group 1, 54·8 months (46·6-61·6) in group 2, and 53·4 months (49·2-59·6) in group 3 (group 2 vs group 1: hazard ratio 0·87 [97·5% CI 0·73-1·05]; group 3 vs group 1: 0·91 [0·76-1·09]). No significant difference was observed for progression-free survival in either comparison and evidence of non-proportional hazards was seen (p=0·037), with restricted mean survival time of 23·9 months (97·5% CI 22·1-25·6) in group 1, 25·3 months (23·6-27·1) in group 2, and 24·8 months (23·0-26·5) in group 3. The most common grade 3-4 adverse events were reduced neutrophil count (78 [15%] of 511 patients in group 1, 183 [36%] of 514 in group 2, and 154 [30%] of 513 in group 3), reduced white blood cell count (22 [4%] in group 1, 80 [16%] in group 2, and 71 [14%] in group 3), and anaemia (26 [5%] in group 1, 66 [13%] in group 2, and 24 [5%] in group 3). No new serious adverse events were reported. Seven treatment-related deaths were reported (two in group 1, four in group 2, and one in group 3). INTERPRETATION: In our cohort of predominantly European women with epithelial ovarian cancer, we found that first-line weekly dose-dense chemotherapy did not improve overall or progression-free survival compared with standard 3-weekly chemotherapy and should not be used as part of standard multimodality front-line therapy in this patient group. FUNDING: Cancer Research UK, Medical Research Council, Health Research Board in Ireland, Irish Cancer Society, and Cancer Australia
Majorana quantization and half-integer thermal quantum Hall effect in a Kitaev spin liquid
The quantum Hall effect (QHE) in two-dimensional (2D) electron gases, which
is one of the most striking phenomena in condensed matter physics, involves the
topologically protected dissipationless charge current flow along the edges of
the sample. Integer or fractional electrical conductance are measured in units
of , which is associated with edge currents of electrons or
quasiparticles with fractional charges, respectively. Here we discover a novel
type of quantization of the Hall effect in an insulating 2D quantum magnet. In
-RuCl with dominant Kitaev interaction on 2D honeycomb lattice, the
application of a parallel magnetic field destroys the long-range magnetic
order, leading to a field-induced quantum spin liquid (QSL) ground state with
massive entanglement of local spins. In the low-temperature regime of the QSL
state, we report that the 2D thermal Hall conductance
reaches a quantum plateau as a function of applied magnetic field.
attains a quantization value of ,
which is exactly half of in the integer QHE. This
half-integer thermal Hall conductance observed in a bulk material is a direct
signature of topologically protected chiral edge currents of charge neutral
Majorana fermions, particles that are their own antiparticles, which possess
half degrees of freedom of conventional fermions. These signatures demonstrate
the fractionalization of spins into itinerant Majorana fermions and
fluxes predicted in a Kitaev QSL. Above a critical magnetic field, the
quantization disappears and goes to zero rapidly,
indicating a topological quantum phase transition between the states with and
without chiral Majorana edge modes. Emergent Majorana fermions in a quantum
magnet are expected to have a major impact on strongly correlated topological
quantum matter.Comment: 7 pages, 8 figures. Submitted versio
Measurement of the top quark mass using the matrix element technique in dilepton final states
We present a measurement of the top quark mass in pp¯ collisions at a center-of-mass energy of 1.96 TeV at the Fermilab Tevatron collider. The data were collected by the D0 experiment corresponding to an integrated luminosity of 9.7 fb−1. The matrix element technique is applied to tt¯ events in the final state containing leptons (electrons or muons) with high transverse momenta and at least two jets. The calibration of the jet energy scale determined in the lepton+jets final state of tt¯ decays is applied to jet energies. This correction provides a substantial reduction in systematic uncertainties. We obtain a top quark mass of mt=173.93±1.84 GeV
Properties of Graphene: A Theoretical Perspective
In this review, we provide an in-depth description of the physics of
monolayer and bilayer graphene from a theorist's perspective. We discuss the
physical properties of graphene in an external magnetic field, reflecting the
chiral nature of the quasiparticles near the Dirac point with a Landau level at
zero energy. We address the unique integer quantum Hall effects, the role of
electron correlations, and the recent observation of the fractional quantum
Hall effect in the monolayer graphene. The quantum Hall effect in bilayer
graphene is fundamentally different from that of a monolayer, reflecting the
unique band structure of this system. The theory of transport in the absence of
an external magnetic field is discussed in detail, along with the role of
disorder studied in various theoretical models. We highlight the differences
and similarities between monolayer and bilayer graphene, and focus on
thermodynamic properties such as the compressibility, the plasmon spectra, the
weak localization correction, quantum Hall effect, and optical properties.
Confinement of electrons in graphene is nontrivial due to Klein tunneling. We
review various theoretical and experimental studies of quantum confined
structures made from graphene. The band structure of graphene nanoribbons and
the role of the sublattice symmetry, edge geometry and the size of the
nanoribbon on the electronic and magnetic properties are very active areas of
research, and a detailed review of these topics is presented. Also, the effects
of substrate interactions, adsorbed atoms, lattice defects and doping on the
band structure of finite-sized graphene systems are discussed. We also include
a brief description of graphane -- gapped material obtained from graphene by
attaching hydrogen atoms to each carbon atom in the lattice.Comment: 189 pages. submitted in Advances in Physic
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On-demand fuzzy clustering and ant-colony optimisation based mobile data collection in wireless sensor network
In a wireless sensor network (WSN), sensor nodes collect data from the environment and transfer this data to an end user through multi-hop communication. This results in high energy dissipation of the devices. Thus, balancing of energy consumption is a major concern in such kind of network. Appropriate cluster head (CH) selection may provide to be an efficient way to reduce the energy dissipation and prolonging the network lifetime in WSN. This paper has adopted the concept of fuzzy if-then rules to choose the cluster head based on certain fuzzy descriptors. To optimise the fuzzy membership functions, Particle Swarm Optimisation (PSO) has been used to improve their ranges. Moreover, recent study has confirmed that the introduction of a mobile collector in a network which collects data through short-range communications also aids in high energy conservation. In this work, the network is divided into clusters and a mobile collector starts from the static sink or base station and moves through each of these clusters and collect data from the chosen cluster heads in a single-hop fashion. Mobility based on Ant-Colony Optimisation (ACO) has already proven to be an efficient method which is utilised in this work. Additionally, instead of performing clustering in every round, CH is selected on demand. The performance of the proposed algorithm has been compared with some existing clustering algorithms. Simulation results show that the proposed protocol is more energy-efficient and provides better packet delivery ratio as compared to the existing protocols for data collection obtained through Matlab Simulations
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