Consumer demands for chickens raised without the use of antibiotics, legislative restrictions, and trade opportunities have encouraged many integrators within the poultry industry to raise poultry ...without antibiotic growth promoters (AGPs) and ionophores. However, with the removal of AGPs and ionophores, the incidence of enteric diseases such as coccidiosis and necrotic enteritis (NE), caused by Eimeria spp. and Clostridium perfringens, respectively, have increased, thereby gaining the attention of the poultry industry to look for alternative strategies to improve bird's health. Coccidiosis and NE are 2 major enteric disease concerns in broilers because of their association with decreased performance, increased mortality, reduced welfare, and a higher risk of poultry product contamination. Necrotic enteritis is often induced after a coccidiosis infection and any factor that causes stress, reduces immunity, and disturbs intestinal ecosystem. Nutritional mitigation strategies have been widely used to reduce such enteric diseases with a greater focus on balanced gut health. Some of the nutritional interventions that have shown potential for improving gut health while reducing overall disease include the use of probiotics, prebiotics, organic acids, essential oils, vaccination, and natural phytochemical extracts in poultry diets. A better understanding of the relationship between nutritional strategies, coccidiosis, and NE is crucial to improve gut health in the absence of AGPs in poultry production. This review will provide information and updates pertaining to current research focusing on several nutritional strategies that have helped to alleviate coccidiosis and NE, by modulating performance and gut health aspects.
Initial performance of the COSINE-100 experiment Adhikari, G.; Adhikari, P.; de Souza, E. Barbosa ...
European physical journal. C, Particles and fields,
02/2018, Letnik:
78, Številka:
2
Journal Article
Recenzirano
Odprti dostop
COSINE is a dark matter search experiment based on an array of low background NaI(Tl) crystals located at the Yangyang underground laboratory. The assembly of COSINE-100 was completed in the summer ...of 2016 and the detector is currently collecting physics quality data aimed at reproducing the DAMA/LIBRA experiment that reported an annual modulation signal. Stable operation has been achieved and will continue for at least 2 years. Here, we describe the design of COSINE-100, including the shielding arrangement, the configuration of the NaI(Tl) crystal detection elements, the veto systems, and the associated operational systems, and we show the current performance of the experiment.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The COSINE-100 dark matter search experiment is an array of NaI(Tl) crystal detectors located in the Yangyang Underground Laboratory (Y2L). To understand measured backgrounds in the NaI(Tl) crystals ...we have performed Monte Carlo simulations using the Geant4 toolkit and developed background models for each crystal that consider contributions from both internal and external sources, including cosmogenic nuclides. The background models are based on comparisons of measurement data with Monte Carlo simulations that are guided by a campaign of material assays and are used to evaluate backgrounds and identify their sources. The average background level for the six crystals (70 kg total mass) that are studied is 3.5 counts/day/keV/kg in the (2–6) keV energy interval. The dominant contributors in this energy region are found to be
210
Pb and
3
H.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The concept of the quasar main sequence is very attractive since it stresses correlations between various parameters and implies the underlying simplicity. In the optical plane defined by the width ...of the Hβ line and the ratio of the equivalent width of the Fe ii to Hβ observed objects form a characteristic pattern. In this paper we use a physically motivated model to explain the distribution of quasars in the optical plane. Continuum is modeled as an accretion disk with a hard X-ray power law uniquely tight to the disk at the basis of observational scaling, and the broad-line region distance is determined also from observational scaling. We perform the computations of the Fe ii and Hβ line production with the code CLOUDY. We have only six free parameters for an individual source, maximum temperature of accretion disk, Eddington ratio, cloud density, cloud column density, microturbulence, and iron abundance, and only the last four remain as global parameters in our modeling of the whole sequence. Our theoretically computed points cover well the optical plane part populated with the observed quasars, particularly if we allow for supersolar abundance of heavy elements. Explanation of the exceptionally strong Fe ii emitter requires stronger contribution from the dark sides of the clouds. Analyzing the way our model covers the optical plane, we conclude that there is no single simple driver behind the sequence, as neither Eddington ratio nor broadband spectrum shape plays the dominant role. Also, the role of the viewing angle in providing the dispersion of the quasar main sequence is apparently not as strong as expected.
Usually photons are not conserved in their interaction with matter. Consequently, for the thermodynamics of photons, while we have a concept of temperature for energy conservation, there is no ...equivalent chemical potential for particle number conservation. However, the notion of a chemical potential is crucial in understanding a wide variety of single- and many-body effects, from transport in conductors and semiconductors to phase transitions in electronic and atomic systems. Here we show how a direct modification of the system-bath coupling via parametric oscillation creates an effective chemical potential for photons even in the thermodynamic limit. In particular, we show that the photonic system equilibrates to the temperature of the bath, with a tunable chemical potential that is set by the frequency of the parametric coupler. Specific implementations, using circuit-QED or optomechanics, are feasible using current technologies, and we show a detailed example demonstrating the emergence of Mott insulator-superfluid transition in a lattice of nonlinear oscillators. Our approach paves the way for quantum simulation, quantum sources, and even electronlike circuits with light.
Staphylococcus aureus, an important nosocomial pathogen, is frequently associated with infections in human. The management of the infections by it especially methicillin resistant ones is often ...difficult because methicillin resistant S. aureus is usually resistant to multiple antibiotics. Macrolide-lincosamide streptogramin B family of antibiotics is commonly used to treat such infections as an alternative to vancomycin.
This study was conducted over the period of one and half year from November 2013-April 2015 in Microbiology laboratory of Nepal Medical College and Teaching Hospital, Kathmandu, Nepal to find the incidence of different phenotypes of MLS
resistance among S. aureus from clinical samples and their association with methicillin resistance. Two hundred seventy isolates of S. aureus were included in the study. Methicillin resistance was detected by cefoxitin disc diffusion method and inducible clindamycin resistance by erythromycin and clindamycin disc approximation test (D-test).
Of the 270 clinical isolates of S. aureus, 25.1% (68/270) were MRSA. Erythromycin and clindamycin resistance was seen in 54.4% (147/270) and 41.8% (113/270) isolates respectively. Resistance to erythromycin and clindamycin were higher in MRSA as compared to MSSA (erythromycin-resistance: 88.2% Vs 39.1% and clindamycin-resistance: 79.4% Vs 41.8%). The overall prevalence of
MLS
and
MLS
phenotype was 11.48% (31/270) and 29.25% (79/270) respectively. Both
MLS
and
MLS
phenotypes predominated in MRSA strains.
Detection rate of MRSA in our study shows the necessity to improve in healthcare practices and to formulate new policy for the control of MRSA infections. Clindamycin resistance in the form of
MLS
and
MLS
especially among MRSA emphasizes the need of D-test to be performed routinely in our set up while using clindamycin as an alternative choice to anti-staphylococcal antibiotics like vancomycin and linezolid in the treatment of staphylococcal infections.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We have developed ultra-low-background NaI(Tl) crystals to reproduce the DAMA results with the ultimate goal of achieving purity levels that are comparable to or better than those of the DAMA/LIBRA ...crystals. Even though the achieved background level does not approach that of DAMA/LIBRA, it is crucial to have a quantitative understanding of the backgrounds. We have studied background simulations toward a deeper understanding of the backgrounds and developed background models for a 9.16-kg NaI(Tl) crystal used in the test arrangement. In this paper we describe the contributions of background sources quantitatively by performing Geant4 Monte Carlo simulations that are fitted to the measured data to quantify the unknown fractions of the background compositions. In the fitted results, the overall simulated background spectrum well describes the measured data with a 9.16-kg NaI(Tl) crystal and shows that the background sources are dominated by surface
210
Pb and internal
40
K in the 2–6-keV energy interval, which produce 2.4 counts/day/keV/kg (dru) and 0.5 dru, respectively.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
SUMMARYSalmonellosis continue to be a major problem for the United States poultry industry. Salmonella outbreaks have been linked to commercial farms and backyard flocks in multiple states over the ...last five years. New serotypes, antimicrobial resistance, and the ability to persist without causing clinical symptoms and flourish when favourable conditions arise are major challenges to control Salmonella. Furthermore, environmental and management conditions and changes in diet can make hens more susceptible to Salmonella infections. Once laying hens acquire Salmonella, it can persist throughout the course of their production. A multifaceted strategy like effective rodent control, Salmonella free facility, appropriate cleaning and sanitising and vaccinations are crucial to control Salmonella infections. The adoption of good hygiene practices and hazard analysis and critical control points also have a significant role in controlling Salmonella at any production level. The use of vaccines has also shown to be effective in controlling Salmonella infection in laying hens. In addition, various nutritional strategies like probiotics, prebiotics and symbiotics are now available to control Salmonella infections. Modulation of gut microbiome could reduce the colonisation of Salmonella in hens. Recent studies have been focused on understanding the effect of intervention strategies on hens’ microbiome and identifying the role of microbiome in preventing Salmonella infections. This review provides an overview on current challenges in controlling Salmonella, interventions that are commonly used to control this infection, as well as the role of microbiome in Salmonella infections.
This study utilizes suspended particles and seafloor sediments collected from the northern Gulf of Mexico (GOM) continental margin to study the fate, transport, residence times and accumulation rates ...of particle-bound polycyclic aromatic hydrocarbons (PAHs). Total particulate-PAHs and particulate organic carbon (POC) varied between 0.9 and 7.0 ng/L, and 4–131 μg/L, respectively. Particulate-PAHs were positively correlated with POC, while both particulate-PAHs and POC were negatively correlated with salinity (P-value < 0.05). These results show that the river-derived particle influx and associated POC are important vectors for transport and fate of particulate-PAHs in the river-dominated northern GOM continental ecosystems. The composition of underlying seafloor sediment-PAHs were not correlated to the water column particulate-PAHs, which is attributed to re-mineralization, sediment resuspension/redistribution and different timescales of comparison. The 210Pb-derived residence time of particles and associated particulate-PAHs in water column varied between 2 and 39 days. Residence times of particulate-PAHs were significantly correlated with seafloor sediment-PAHs accumulation rates, shorter water column residence times leading to higher PAHs accumulation rates.
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•First estimates of 210Pb-based residence time of particulate-PAHs in the northern GOM.•Concentration of particulate-PAHs and POC varied between 0.9 –7.0 ng/L, and 4–131 µg/L, respectively.•Total and individual PAHs in suspended particles had strong positive correlation with POC.•The Mississippi River-derived particles play a major role in transport and fate of particulate-PAHs in the northern GOM.•210Pb-derived residence time of particles in the northern GOM varies between 2-39 days.
We present new constraints on the dark matter-induced annual modulation signal using 1.7 years of COSINE-100 data with a total exposure of 97.7 kg yr. The COSINE-100 experiment, consisting of 106 kg ...of NaI(Tl) target material, is designed to carry out a model-independent test of DAMA/LIBRA's claim of WIMP discovery by searching for the same annual modulation signal using the same NaI(Tl) target. The crystal data show a 2.7 cpd/kg/keV background rate on average in the 2-6 keV energy region of interest. Using a χ-squared minimization method we observe best fit values for modulation amplitude and phase of 0.0092±0.0067 cpd/kg/keV and 127.2±45.9 d, respectively.
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