349 research outputs found
The X-ray Cluster Normalization of the Matter Power Spectrum
The number density of galaxy clusters provides tight statistical constraints
on the matter fluctuation power spectrum normalization, traditionally phrased
in terms of sigma_8, the root mean square mass fluctuation in spheres with
radius 8 h^-1 Mpc. We present constraints on sigma_8 and the total matter
density Omega_m0 from local cluster counts as a function of X-ray temperature,
taking care to incorporate and minimize systematic errors that plagued previous
work with this method. In particular, we present new determinations of the
cluster luminosity - temperature and mass - temperature relations, including
their intrinsic scatter, and a determination of the Jenkins mass function
parameters for the same mass definition as the mass - temperature calibration.
Marginalizing over the 12 uninteresting parameters associated with this method,
we find that the local cluster temperature function implies sigma_8
(Omega_m0/0.32)^alpha = 0.86+/-0.04 with alpha = 0.30 (0.41) for Omega_m0 <
0.32 (Omega_mo > 0.32) (68% confidence for two parameters). This result agrees
with a wide range of recent independent determinations, and we find no evidence
of any additional sources of systematic error for the X-ray cluster temperature
function determination of the matter power spectrum normalization. The joint
WMAP5 + cluster constraints are: Omega_m0 = 0.30+0.03/-0.02 and sigma_8 =
0.85+0.04/-0.02 (68% confidence for two parameters).Comment: 31 pages, 16 figures, accept for publication in ApJ 609, Jan. 10,
200
The phase-diagram of the IGM and the entropy floor of groups and clusters: are clusters born warm?
We point out that two problems of observational cosmology, the facts i) that
> 60% of the baryonic content of the universe is not observed at z=0 and ii)
that the properties of small clusters do not agree with simple expectations,
could be closely related. As shown by recent studies, the shock-heating
associated with the formation of large-scale structures heats the intergalactic
medium (IGM) and leads to a ``warm IGM'' component for the gas. In the same
spirit, we suggest the intracluster medium (ICM) to be a mixture of
galaxy-recycled, metal enriched gas and intergalactic gas, shock-heated by the
collapsing much larger scales. This could be obtained through two processes: 1)
the late infalling gas from the external warm IGM is efficiently mixed within
the halo and brings some additional entropy, or 2) the shocks generated by
larger non-linear scales are also present within clusters and can heat the ICM.
We show that if assumption (1) holds, the entropy brought by the warm IGM is
sufficient to explain the observed properties of clusters, in particular the
entropy floor and the LX-T relation. On the other hand, we briefly note that
the scenario (2) would require a stronger shock-heating because of the larger
density of the ICM as compared with filaments. Our scenario of clusters being
"born warm" can be checked through the predicted redshift evolution of the
entropy floor.Comment: 8 pages, final version published in MNRA
VET&PHARM pilot project: A case study focusing on the perceived value of a pilot seminar on interprofessional communication for students in Pharmacy and Veterinary Medicine in the rational delivery of drugs for veterinary use
Antibiotic resistance has gained attention, prompting changes in prescribing practices in human and veterinary medicine. However, this hasn't extended to over-the-counter drugs like antiparasitic medications. The current public health landscape emphasizes interdisciplinary approaches in healthcare. Strengthening community pharmacists' proficiency in veterinary pharmacotherapy is crucial, especially in addressing antiparasitic resistance and environmental impact. The VET&PHARM pilot project aimed to evaluate the perceived value of an interdisciplinary healthcare simulation in education, involving pharmacy and veterinary students. Methods: This study assessed the perceived value of an interdisciplinary healthcare simulation focusing on rational pharmacy-based veterinary drug dispensing. Students engaged in role-playing, simulating the rational delivery of veterinary medications at an educational pharmacy counter. Scenarios included a pharmacist receiving a veterinary drug request from a pet owner. Unable to fulfill it without consulting a veterinarian, a telemedicine sequence ensued between the pharmacist and the vet. Debriefings emphasized professionals' actions and their impact on patient and animal care. The activity, with 40 student volunteers, featured two VET&PHARM sessions in May 2022. Post-activity, an online questionnaire assessed perceived value for both pharmacy and veterinary students. Results: With an 82.5% response rate, post-intervention questionnaires highlighted the educational interest of the pilot seminar. Students reported improved collaboration and confidence in providing veterinary medicine services and counseling. Discussion and Conclusion: Beyond developing communication and collaboration skills, students exceeded expectations, embracing the One Health vision. This initiative addresses the urgent need for improved rational dispensing practices in veterinary medicines, contributing to the overarching goal of enhancing healthcare delivery in pharmacy.15. Life on lan
Yam Cropping System in Cote d’Ivoire: Current Practices and Constraints
Yam is the first food crop in Côte d'Ivoire. It is being cultivated under a traditional technique system with low output. Detailed profiling of the current practices and opportunities for improvement is essential to increase the benefits of yam for food security and income in the country. This study diagnosed the current practices, constraints, and requirements in order to gain insight on the yam cropping system for research and development in Côte d'Ivoire. The surveys were conducted in seven (7) regions in the main yam production area. Groups of 60 producers per region were investigated. Individual surveys were also conducted on-farm, particularly for diagnosing the physical environment and yam-based production systems. As results, yambased production systems are characterized by mixed cropping (cassava, corn and vegetable crops) and/or rotation with various other crops (rice, groundnut, vegetable crops, …). Preferred plots for yam cultivation are forest, savannah or fallow areas. The major constraints in yam cultivation were the effects of environmental stresses, labor scarcity, pest damage, tuber and seed storage difficulties as well as the low market value of yam. The most cultivated yam varieties are Bètè-Bètè and Florido for Dioscorea alata and Lokpa for Dioscorea rotundata. The cropping system, the species and varieties vary according to the region, the topo sequence and the type of soil. Knowledgebuilding that take into account constraints related to yam cultivation, for each production area, can serve as guidance for variety breeding and cultivation environment redefinition
FIREBall-2: advancing TRL while doing proof-of-concept astrophysics on a suborbital platform
Here we discuss advances in UV technology over the last decade, with an
emphasis on photon counting, low noise, high efficiency detectors in
sub-orbital programs. We focus on the use of innovative UV detectors in a NASA
astrophysics balloon telescope, FIREBall-2, which successfully flew in the Fall
of 2018. The FIREBall-2 telescope is designed to make observations of distant
galaxies to understand more about how they evolve by looking for diffuse
hydrogen in the galactic halo. The payload utilizes a 1.0-meter class telescope
with an ultraviolet multi-object spectrograph and is a joint collaboration
between Caltech, JPL, LAM, CNES, Columbia, the University of Arizona, and NASA.
The improved detector technology that was tested on FIREBall-2 can be applied
to any UV mission. We discuss the results of the flight and detector
performance. We will also discuss the utility of sub-orbital platforms (both
balloon payloads and rockets) for testing new technologies and proof-of-concept
scientific ideasComment: Submitted to the Proceedings of SPIE, Defense + Commercial Sensing
(SI19
Association between antithrombotic treatment and outcomes at 1-year follow-up in patients with atrial fibrillation: the EORP-AF General Long-Term Registry
In recent years, stroke prevention in patients with atrial fibrillation (AF) has radically changed, with increasing use of non-vitamin K antagonist oral anticoagulants (NOACs). Contemporary European data on AF thromboprophylaxis are needed
Impact of the 2019 typhoons on sediment source contributions and radiocesium concentrations in rivers draining the Fukushima radioactive plume, Japan
Impact of Vitamin D Supplementation on Influenza Vaccine Response and Immune Functions in Deficient Elderly Persons: A Randomized Placebo-Controlled Trial
Background: Immunosenescence contributes to reduced vaccine response in elderly persons, and is worsened by deficiencies in nutrients such as Vitamin (Vit-D). The immune system is a well-known target of Vit-D, which can both potentiate the innate immune response and inhibit the adaptive system, and so modulate vaccination response.Objective: This randomized placebo-controlled double-blind trial investigated whether Vit-D supplementation in deficient elderly persons could improve influenza seroprotection and immune response.Design: Deficient volunteers (Vit-D serum <30 ng/mL) were assigned (V1) to receive either 100,000 IU/15 days of cholecalciferol (D, n = 19), or a placebo (P, n = 19), over a 3 month period. Influenza vaccination was performed at the end of this period (V2), and the vaccine response was evaluated 28 days later (V3). At each visit, serum cathelicidin, immune response to vaccination, plasma cytokines, lymphocyte phenotyping, and phagocyte ROS production were assessed.Results: Levels of serum 25-(OH)D increased after supplementation (D group, V1 vs. V2: 20.7 ± 5.7 vs. 44.3 ± 8.6 ng/mL, p < 0.001). No difference was observed for serum cathelicidin levels, antibody titers, and ROS production in D vs. P groups at V3. Lower plasma levels of TNFα (p = 0.040) and IL-6 (p = 0.046), and higher ones for TFGβ (p = 0.0028) were observed at V3. The Th1/Th2 ratio was lower in the D group at V2 (D: 0.12 ± 0.05 vs. P: 0.18 ± 0.05, p = 0.039).Conclusions: Vit-D supplementation promotes a higher TGFβ plasma level in response to influenza vaccination without improving antibody production. This supplementation seems to direct the lymphocyte polarization toward a tolerogenic immune response. A deeper characterization of metabolic and molecular pathways of these observations will aid in the understanding of Vit-D's effects on cell-mediated immunity in aging. This clinical trial was registered at clinicaltrials.gov as NCT01893385
First lensing measurements of SZ-discovered clusters
We present the first lensing mass measurements of Sunyaev-Zel'dovich (SZ)
selected clusters. Using optical imaging from the Southern Cosmology Survey
(SCS), we present weak lensing masses for three clusters selected by their SZ
emission in the South Pole Telescope survey (SPT). We confirm that the SZ
selection procedure is successful in detecting mass concentrations. We also
study the weak lensing signals from 38 optically-selected clusters in ~8 square
degrees of the SCS survey. We fit Navarro, Frenk and White (NFW) profiles and
find that the SZ clusters have amongst the largest masses, as high as 5x10^14
Msun. Using the best fit masses for all the clusters, we analytically calculate
the expected SZ integrated Y parameter, which we find to be consistent with the
SPT observations.Comment: Minor changes to match accepted version, 5 pages, 3 figure
- …