136 research outputs found
Constraining Non-Standard Interactions of the Neutrino with Borexino
We use the Borexino 153.6 ton.year data to place constraints on non-standard
neutrino-electron interactions, taking into account the uncertainty in the 7Be
solar neutrino flux, and backgrounds due to 85Kr and 210Bi beta-decay. We find
that the bounds are comparable to existing bounds from all other experiments.
Further improvement can be expected in Phase II of Borexino due to the
reduction in the 85Kr background.Comment: 21 pages, 16 pdf figures, 2 tables. Analysis updated including the
uncertainty in sin^2\theta_{23}. Accepted in JHE
Congenital leptin deficiency and leptin gene missense mutation found in two colombian sisters with severe obesity
Background: Congenital leptin deficiency is a recessive genetic disorder associated with severe early-onset obesity. It is caused by mutations in the leptin (LEP) gene, which encodes the protein product leptin. These mutations may cause nonsense-mediated mRNA decay, defective secretion or the phenomenon of biologically inactive leptin, but typically lead to an absence of circulating leptin, resulting in a rare type of monogenic extreme obesity with intense hyperphagia, and serious metabolic abnormalities. Methods: We present two severely obese sisters from Colombia, members of the same lineal consanguinity. Their serum leptin was measured by MicroELISA. DNA sequencing was performed on MiSeq equipment (Illumina) of a next-generation sequencing (NGS) panel involving genes related to severe obesity, including LEP. Results: Direct sequencing of the coding region of LEP gene in the sisters revealed a novel homozygous missense mutation in exon 3 [NM_002303.3], C350G>T [p.C117F]. Detailed information and clinical measurements of these sisters were also collected. Their serum leptin levels were undetectable despite their markedly elevated fat mass. Conclusions: The mutation of LEP, absence of detectable leptin, and the severe obesity found in these sisters provide the first evidence of monogenic leptin deficiency reported in the continents of North and South America. © 2019 by the authors. Licensee MDPI, Basel, Switzerland
Semi-analytical covariance matrices for two-point correlation function for DESI 2024 data
We present an optimized way of producing the fast semi-analytical covariance
matrices for the Legendre moments of the two-point correlation function, taking
into account survey geometry and mimicking the non-Gaussian effects. We
validate the approach on simulated (mock) catalogs for different galaxy types,
representative of the Dark Energy Spectroscopic Instrument (DESI) Data Release
1, used in 2024 analyses. We find only a few percent differences between the
mock sample covariance matrix and our results, which can be expected given the
approximate nature of the mocks, although we do identify discrepancies between
the shot-noise properties of the DESI fiber assignment algorithm and the faster
approximation used in the mocks. Importantly, we find a close agreement (<~ 5%
relative differences) in the projected errorbars for distance scale parameters
for the baryon acoustic oscillation measurements. This confirms our method as
an attractive alternative to simulation-based covariance matrices, especially
for non-standard models or galaxy sample selections, in particular, relevant to
the broad current and future analyses of DESI data.Comment: Supporting publication of DESI 2024 III: Baryon Acoustic Oscillations
from Galaxies and Quasars (arXiv:2404.03000). 29 pages, 4 figures. Prepared
for submission to JCAP. Code available at
https://github.com/oliverphilcox/RascalC and
https://github.com/misharash/RascalC-scripts/tree/DESI2024. Data points from
the plots available at https://zenodo.org/doi/10.5281/zenodo.1089516
A Small Mammal Community in a Forest Fragment, Vegetation Corridor and Coffee Matrix System in the Brazilian Atlantic Forest
The objective of our work was to verify the value of the vegetation corridor in the conservation of small mammals in fragmented tropical landscapes, using a model system in the southeastern Minas Gerais. We evaluated and compared the composition and structure of small mammals in a vegetation corridor, forest fragments and a coffee matrix. A total of 15 species were recorded, and the highest species richness was observed in the vegetation corridor (13 species), followed by the forest fragments (10) and the coffee matrix (6). The absolute abundance was similar between the vegetation corridor and fragments (F = 22.94; p = 0.064), and the greatest differences occurred between the vegetation corridor and the matrix (F = 22.94; p = 0.001) and the forest fragments and the matrix (F = 22.94; p = 0.007). Six species showed significant habitat preference possibly related to the sensitivity of the species to the forest disturbance. Marmosops incanus was the species most sensitive to disturbance; Akodon montensis, Cerradomys subflavus, Gracilinanus microtarsus and Rhipidomys sp. displayed little sensitivity to disturbance, with a high relative abundance in the vegetation corridor. Calomys sp. was the species least affected by habitat disturbance, displaying a high relative abundance in the coffee matrix. Although the vegetation corridors are narrow (4 m width), our results support the hypothesis in which they work as a forest extension, share most species with the forest fragment and support species richness and abundance closer to forest fragments than to the coffee matrix. Our work highlights the importance and cost-effectiveness of these corridors to biodiversity management in the fragmented Atlantic Forest landscapes and at the regional level
HOD-Dependent Systematics for Luminous Red Galaxies in the DESI 2024 BAO Analysis
In this paper, we present the estimation of systematics related to the halo
occupation distribution (HOD) modeling in the baryon acoustic oscillations
(BAO) distance measurement of the Dark Energy Spectroscopic Instrument (DESI)
2024 analysis. This paper focuses on the study of HOD systematics for luminous
red galaxies (LRG). We consider three different HOD models for LRGs, including
the base 5-parameter vanilla model and two extensions to it, that we refer to
as baseline and extended models. The baseline model is described by the 5
vanilla HOD parameters, an incompleteness factor and a velocity bias parameter,
whereas the extended one also includes a galaxy assembly bias and a satellite
profile parameter. We utilize the 25 dark matter simulations available in the
AbacusSummit simulation suite at 0.8 and generate mock catalogs for our
different HOD models. To test the impact of the HOD modeling in the position of
the BAO peak, we run BAO fits for all these sets of simulations and compare the
best-fit BAO-scaling parameters and
between every pair of HOD models. We do this for both Fourier and configuration
spaces independently, using post-reconstruction measurements. We find a
3.3 detection of HOD systematic for in configuration
space with an amplitude of 0.19%. For the other cases, we did not find a
3 detection, and we decided to compute a conservative estimation of the
systematic using the ensemble of shifts between all pairs of HOD models. By
doing this, we quote a systematic with an amplitude of 0.07% in for both Fourier and configuration spaces; and of 0.09% in for Fourier space.Comment: 36 pages, 9 figures. Supporting publication of DESI 2024 III: Baryon
Acoustic Oscillations from Galaxies and Quasar
Immigration Rates in Fragmented Landscapes – Empirical Evidence for the Importance of Habitat Amount for Species Persistence
BACKGROUND: The total amount of native vegetation is an important property of fragmented landscapes and is known to exert a strong influence on population and metapopulation dynamics. As the relationship between habitat loss and local patch and gap characteristics is strongly non-linear, theoretical models predict that immigration rates should decrease dramatically at low levels of remaining native vegetation cover, leading to patch-area effects and the existence of species extinction thresholds across fragmented landscapes with different proportions of remaining native vegetation. Although empirical patterns of species distribution and richness give support to these models, direct measurements of immigration rates across fragmented landscapes are still lacking. METHODOLOGY/PRINCIPAL FINDINGS: Using the Brazilian Atlantic forest marsupial Gray Slender Mouse Opossum (Marmosops incanus) as a model species and estimating demographic parameters of populations in patches situated in three landscapes differing in the total amount of remaining forest, we tested the hypotheses that patch-area effects on population density are apparent only at intermediate levels of forest cover, and that immigration rates into forest patches are defined primarily by landscape context surrounding patches. As expected, we observed a positive patch-area effect on M. incanus density only within the landscape with intermediate forest cover. Density was independent of patch size in the most forested landscape and the species was absent from the most deforested landscape. Specifically, the mean estimated numbers of immigrants into small patches were lower in the landscape with intermediate forest cover compared to the most forested landscape. CONCLUSIONS/SIGNIFICANCE: Our results reveal the crucial importance of the total amount of remaining native vegetation for species persistence in fragmented landscapes, and specifically as to the role of variable immigration rates in providing the underlying mechanism that drives both patch-area effects and species extinction thresholds
Validation of the Scientific Program for the Dark Energy Spectroscopic Instrument
The Dark Energy Spectroscopic Instrument (DESI) was designed to conduct a
survey covering 14,000 deg over five years to constrain the cosmic
expansion history through precise measurements of Baryon Acoustic Oscillations
(BAO). The scientific program for DESI was evaluated during a five month Survey
Validation (SV) campaign before beginning full operations. This program
produced deep spectra of tens of thousands of objects from each of the stellar
(MWS), bright galaxy (BGS), luminous red galaxy (LRG), emission line galaxy
(ELG), and quasar target classes. These SV spectra were used to optimize
redshift distributions, characterize exposure times, determine calibration
procedures, and assess observational overheads for the five-year program. In
this paper, we present the final target selection algorithms, redshift
distributions, and projected cosmology constraints resulting from those
studies. We also present a `One-Percent survey' conducted at the conclusion of
Survey Validation covering 140 deg using the final target selection
algorithms with exposures of a depth typical of the main survey. The Survey
Validation indicates that DESI will be able to complete the full 14,000 deg
program with spectroscopically-confirmed targets from the MWS, BGS, LRG, ELG,
and quasar programs with total sample sizes of 7.2, 13.8, 7.46, 15.7, and 2.87
million, respectively. These samples will allow exploration of the Milky Way
halo, clustering on all scales, and BAO measurements with a statistical
precision of 0.28% over the redshift interval , 0.39% over the redshift
interval , and 0.46% over the redshift interval .Comment: 42 pages, 18 figures, accepted by A
The Early Data Release of the Dark Energy Spectroscopic Instrument
\ua9 2024. The Author(s). Published by the American Astronomical Society. The Dark Energy Spectroscopic Instrument (DESI) completed its 5 month Survey Validation in 2021 May. Spectra of stellar and extragalactic targets from Survey Validation constitute the first major data sample from the DESI survey. This paper describes the public release of those spectra, the catalogs of derived properties, and the intermediate data products. In total, the public release includes good-quality spectral information from 466,447 objects targeted as part of the Milky Way Survey, 428,758 as part of the Bright Galaxy Survey, 227,318 as part of the Luminous Red Galaxy sample, 437,664 as part of the Emission Line Galaxy sample, and 76,079 as part of the Quasar sample. In addition, the release includes spectral information from 137,148 objects that expand the scope beyond the primary samples as part of a series of secondary programs. Here, we describe the spectral data, data quality, data products, Large-Scale Structure science catalogs, access to the data, and references that provide relevant background to using these spectra
Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study
Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised
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