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Artificial insemination (AI) technology use in poultry production has enabled the rapid dissemination of genetic material from a small number of superior males to a high number of females. Excellent fertility in poultry can be obtained by AI compared to natural mating. Successful application of this technique needs good quality semen that should be inseminated very close to the sperm storage tubules in the female to obtain the optimum fertility in chicken. Since the 1950s, AI has been used in commercial poultry production, initially in Israel and Australia, followed by the USA. Doses of spermatozoa required for AI increases with storage time or that obtained from aged bird. The average volume of semen is between 0.05-0.50 ml in light chicken breeds and 0.1-0.9 ml in heavy males. In light turkeys, volume is 0.08-0.30 ml, whereas in heavy-weight males it is 0.1-0.33 ml. Quality evaluation of semen gives an indication of the male reproductive potential and is the major determinant of fertility and subsequently hatchability of eggs. Semen from cockerels contains between 3-7 billion sperm cells/ml. Among the several factors that influence the semen quality, sperm motility is a primary determinant of fertility in domestic fowls; however, visual examination of semen cannot be ignored for successful AI under field conditions. Dilution of low and viscous volume of avian semen is essential for handling and storage, and chicken semen typically requires a two to three-fold dilution. Collected samples should be preserved at 2-8°C for avian species, ideally with turkey sperm stored at 4-8°C, and chicken semen at 7-8°C for good fertility. Currently, the technique of AI in most of the poultry species is well developed; however, there is a need for successful development programme of this technique in non-domesticated birds to assist in creating viable, self-sustaining populations of critically endangered species.
Improving understanding of the pathogen-specific seasonality of enteric infections is critical to informing policy on the timing of preventive measures and to forecast trends in the burden of diarrhoeal disease. Data obtained from active surveillance of cohorts can capture the underlying infection status as transmission occurs in the community. The purpose of this study was to characterise rotavirus seasonality in eight different locations while adjusting for age, calendar time and within-subject clustering of episodes by applying an adapted Serfling model approach to data from a multi-site cohort study. In the Bangladesh and Peru sites, within-subject clustering was high, with more than half of infants who experienced one rotavirus infection going on to experience a second and more than 20% experiencing a third. In the five sites that are in countries that had not introduced the rotavirus vaccine, the model predicted a primary peak in prevalence during the dry season and, in three of these, a secondary peak during the rainy season. The patterns predicted by this approach are broadly congruent with several emerging hypotheses about rotavirus transmission and are consistent for both symptomatic and asymptomatic rotavirus episodes. These findings have practical implications for programme design, but caution should be exercised in deriving inferences about the underlying pathways driving these trends, particularly when extending the approach to other pathogens.
The merits of solar coronal at metric-wavelength (MW) radio have long been recognised (e.g. Pick and Vilmer, 2008). High-fidelity solar radio imaging at these frequencies has however remained challenging. On the one hand, dealing with the small spectral and temporal scales of variation in solar radio emission requires a data product capable of tracking the emission simultaneously across time, frequency and morphology. The Fourier imaging nature of interferometry, on the other hand, severely limits the instrumental ability to gather sufficient information to do this with the required fidelity and resolution. Benefiting from the enormous advances in technology the new generation of instruments, like the Murchison Widefield Array (MWA; Tingay et al. (2013), Bowman et al. (2013)), represent a quantum leap in our ability to gather data suitable for radio solar physics.
At low radio frequencies the solar corona is very dynamic in both spectral and temporal domains. To capture the fine details of this complex dynamics, imaging studies at high temporal and spectral resolution are necessary. The advent of the new instruments like the Murchison Widefield Array (MWA; Tingay et al. 2013, Bowman et al. 2013), is now making this possible.
In birds, after natural mating or artificial insemination (AI), sperms are transported through cloaca or vagina at the utero-vaginal junction (UVJ) of oviduct. Only 1% of the deposited sperm passes through the selection process in the vagina to reach the UVJ. In the UVJ, sperm enter the tubular invagination of the surface epithelium of the mucosa collectively called ‘sperm storage tubules’ (SSTs) where they are stored for longer duration retaining their fertilising capacity. The storage capacity and duration varies from species to species. This enables the birds to produce fertile eggs continuously. Shortly before and during egg production, sperm residing in the SST upon release will ascend the oviduct to the site of fertilisation in the infundibulum. Within the SSTs, sperm motility is suppressed and is initiated at some stage before fertilisation. Restoration of sperm motility is necessary for the release of spermatozoa from the SSTs. The exact mechanism by which sperm are stored in these tubules and released has not been established and hence, this is the focus of this review.
To estimate the proportion of products meeting Indian government labelling regulations and to examine the Na levels in packaged foods sold in India.
Nutritional composition data were collected from the labels of all packaged food products sold at Indian supermarkets in between 2012 and 2014. Proportions of products compliant with the Food Safety Standards Authority of India (FSSAI) regulations and labelled with Na content, and mean Na levels were calculated. Comparisons were made against 2010 data from Hyderabad and against the UK Department of Health (DoH) 2017 Na targets.
Eleven large chain retail stores in Delhi and Hyderabad, India.
Packaged food products (n 5686) categorised into fourteen food groups, thirty-three food categories and ninety sub-categories.
More packaged food products (43 v. 34 %; P<0·001) were compliant with FSSAI regulations but less (32 v. 38 %; P<0·001) reported Na values compared with 2010. Food groups with the highest Na content were sauces and spreads (2217 mg/100 g) and convenience foods (1344 mg/100 g). Mean Na content in 2014 was higher in four food groups compared with 2010 and lower in none (P<0·05). Only 27 % of foods in sub-categories for which there are UK DoH benchmarks had Na levels below the targets.
Compliance with nutrient labelling in India is improving but remains low. Many packaged food products have high levels of Na and there is no evidence that Indian packaged foods are becoming less salty.
Introduction: Weight concerns may inhibit smoking quit attempts and may be more influential amongst African-Americans who are more likely to be overweight.
Aims: To assess if weight perception is associated with readiness to quit and whether this relationship is modified by race.
Methods: We used data from a cohort of current smokers undergoing routine health examinations. Based on differences between ideal and measured BMI, participants’ weight perceptions were classified as within, somewhat above, or far above ideal weight. Logistic regression analysis was used to evaluate adjusted associations of weight perception and race with readiness to quit.
Results: Of 2,831 current smokers, 23% were obese and 38% overweight. Amongst white smokers, those who perceived being far above ideal weight were more likely to be ready to quit (OR: 1.45, 95% CI: 1.03–2.03), but this association was not observed for African-American smokers who perceived themselves to be somewhat or far above their ideal weight (OR: 0.35, 95% CI: 0.10–1.24 and OR: 0.36, 95% CI: 0.11–1.19, respectively).
Conclusions: Perception of being overweight is associated with increased readiness to quit amongst white but not African-American smokers. Smoking cessation programmes may need to culturally tailor interventions based on smokers’ weight perceptions.
Recent ROSAT and EUVE detections of spin-powered neutron stars suggest that many emit ‘thermal’ radiation, peaking in the EUV/soft X-ray band. These data constrain the neutron stars’ thermal history, but interpretation requires comparison with model atmosphere computations, since emergent spectra depend strongly on the surface composition and magnetic field. As recent opacity computations show substantial change to absorption cross sections at neutron star photospheric conditions, we report here on new model atmosphere computations employing such data. The results are compared with magnetic atmosphere models and applied to PSR J0437−4715, a low field neutron star.
The Evolutionary Map of the Universe (EMU) is a proposed radio continuum survey
of the Southern Hemisphere up to declination + 30°, with the Australian
Square Kilometre Array Pathfinder (ASKAP). EMU will use an automated source
identification and measurement approach that is demonstrably optimal, to
maximise the reliability and robustness of the resulting radio source
catalogues. As a step toward this goal we conducted a “Data
Challenge” to test a variety of source finders on simulated images. The
aim is to quantify the accuracy and limitations of existing automated source
finding and measurement approaches. The Challenge initiators also tested the
current ASKAPsoft source-finding tool to establish how it could benefit from
incorporating successful features of the other tools. As expected, most finders
show completeness around 100% at ≈ 10σ dropping to about 10% by
≈ 5σ. Reliability is typically close to 100% at ≈
10σ, with performance to lower sensitivities varying between finders. All
finders show the expected trade-off, where a high completeness at low
signal-to-noise gives a corresponding reduction in reliability, and vice versa.
We conclude with a series of recommendations for improving the performance of
the ASKAPsoft source-finding tool.
Background and Purpose: Carotid artery stenting (CAS) has been, historically, an alternative to open endarterectomy (CEA) for stroke prevention in high risk patients with carotid atherosclerosis. We sought to determine the rates of periprocedural and long-term stroke or death and the risk factors for complications after CAS in our high risk patient population. Methods: Clinical and treatment variables of consecutive CAS procedures performed between 2002 and 2011 were analyzed. Using univariate and multivariate logistic regression analyses we examined how patient characteristics influenced outcomes and changes in modified Rankin Score (mRS). Results: In 152 patients, the composite total of periprocedural death, stroke, transient ischemic attack (TIA) and myocardial infarction (MI) rate was 3.95% (6/152). Chronic kidney disease (CKD) was strongly associated with periprocedural complications (p<0.001). Coronary artery disease/peripheral vascular disease (CAD/PVD) (p=0.03), dyslipidemia (p=0.02), CKD (p=0.01), and contralateral internal carotid artery stenosis (p=0.02) were non-modifiable risk factors for mRS increase. There were 25 deaths, 8 strokes, 11 TIAs, and 1 MI (mean follow-up 38.4 months, range 0-116 months). The presence of CAD/PVD (p=0.009) and dyslipidemia (p=0.002) were significantly associated with long-term complications. Conclusion: CAS was performed with low periprocedural complications in high-risk patients. Our rates compare very favorably to large-scale trials that have ideal patients. This data encourages the consideration of CAS in patients considered high risk for CEA and provides possible patient characteristics (CKD) to help with periprocedural risk stratification.
Gallium nitride (n-type) films of thickness 300nm were grown on c-plane sapphire substrates using plasma assisted molecular beam epitaxy (PA-MBE). High resolution X-ray diffraction and photoluminescence measurements were used to confirm the crystalline and optical qualities of the grown films. Metal-semiconductor Schottky diodes were fabricated using Pt as the Schottky metal and Al as the Ohmic metal contact. Metal-insulator-semiconductor Schottky diodes were also fabricated using HfO2 (10nm) as the insulator material. Diode parameters like barrier height and ideality factor were extracted from I-V measurements. Introduction of HfO2 as the insulator layer leads to better rectifying behavior (forward to reverse current ratio improves from 5.1 to 8.9) with a reduction in reverse leakage current (by 7.4 times), increase in barrier height (from 0.62eV to 0.74eV) and a reduction in ideality factor (from 6 to 4.1) of the Schottky diode.
The initial stages of germanium heteroepitaxy on vicinal Si(100) have been studied using in-situ deposition in a UHV STEM. Germanium was deposited using molecular beam techniques onto substrates misoriented 1° and 5* toward <110> held at room temperature, 375°C and 525°C. Film thicknesses were in the range 4-6 ML, just greater than the stable intermediate layer of 3-4ML (1ML = 0.14nm). The Ge clusters were observed using biassed secondary electron (b-SE) imaging with nanometer resolution. Comparisons were made between deposition at the elevated temperatures, and room temperature deposition followed by anneals at the same temperatures.
Annealing the low temperature deposits produces coarsening of the islands which is similar on the 1° and 5° samples. Island size distributions and other film growth parameters obtained from the 375°C and 525°C anneals indicate that the coarsening is different at these temperatures and is possibly affected by instabilities in the intermediate layer. Results of the high temperature depositions indicate that neither surface steps nor the edges of islands act as perfect sinks, and that diffusion distances are of the order of several microns. The nucleation density and size distributions are markedly different for deposition at 375°C and 525°C possibly due to competitive capture at strong sinks.
In a parallel set of experiments in a standard UHV chamber, macroscopic wafer samples were analyzed with RHEED, Auger and secondary electron spectroscopy. These correlate well with the intermediate layer thicknesses previously reported in the literature, and the large contrast observed in the b-SE images. Ex situ TEM studies of samples grown in this chamber show islands with various contrast features including those of coherent strain.
Liquid-solid and solid state phase equilibria in the ternary system Ti-Al-V have been studied using a combination of several experimental techniques. A likely surface of primary seperation (i.e., the liquidus surface) is proposed in the form of the usual projection on the triangular base and the directions of the monovariant lines are defined. Four ternary invariant reactions have been identified in this system. Solid state equilibria have been determined at 900°C and are presented in the form of an isothermal section through the phase diagram. These are very similar to the relationships reported at 800°C by Hashimoto et al. .
Rheo-optical studies on aligned and unaligned melts of a main chain thermotropic polyester with flexible spacers are discussed in terms of the predictions of the Ericksen-Leslie equations. It is shown, using conoscopy, that the director is flowaligning at temperatures close to TNI and nonflow-aligning close to a smectic to nematic (TSN) phase transition. The implications of these results are discussed in terms of the change in sign of one of the Leslie viscosity coefficients and interpreted in the framework of the Ericksen-Leslie Theory.
We have studied the initial stages of island formation and coarsening for epitaxial Ge on vicinal Si (100) using in-situ deposition and nanometer resolution biassed secondary electron imaging (b-SEI) in a UHV-STEM. Ge is deposited using MBE techniques on nominally flat Si(100) substrates as well as those misoriented 1° and 5° toward <110>. The temporal evolution of the islanded microstructure can be studied by analysis of computer generated island size distributions. Good statistics can be obtained for islands with radii between 2nm and lOOnm using high resolution b-SE imaging and a large magnification range. Both MBE and Solid phase MBE (SP-MBE) processes have been studied.
We explain the evolution of the islanded microstructure in terms of competition for Ge adatoms among the various available sinks. For the MBE case, control of diffusion distances by varying the substrate temperature has allowed us to identify effects related to coherently strained and highly dislocated Ge islands as well as contaminant particles. In all cases, coherently strained Ge islands appear to be the weakest sinks and contaminant particles the strongest. Metastable growth of the intermediate layer during interrupted depositions at 375°C may be a direct consequence of an energy cost for incorporating adatoms into coherently strained islands. For depositions at higher temperatures, strong adatom sinks influence nucleation densities and size distributions of Ge islands by reducing the effective supersaturation. Island size distributions analyzed for the case of room temperature deposition in the early stages of coarsening also show evidence of effects due to coherently strained islands. These size distributions evolve from an initial distribution to one with increasing number of large islands while the distribution of the smaller islands (< 10nm radius) remains constant.
Thin films of Ceria, Titania and Ziroonia have been prepared using Ion Assisted Deposition(IAD). The energy of ions was varied between 0 and 1 keV and current densities up to 220 μA/cm were used. It was found that the stress behaviour is dependent on ion species, i.e. Argon or Oxygen, ion energy and current density and substrate temperature apart from the material. While oeria files showed tensile stresses under the influence of argon ion bombardment at ambient temperature, they showed a sharp transition from tensile to compressive stress with increase in substrate temperature. When bombarded with oxygen ions they showed a transition from tensile to compressive stress with increase in energy. The titania films deposited with oxygen ions, on the other hand showed purely tensile stresses. Zirconia films deposited with oxygen ions, however, showed a transition from tensile to compressive stress.
Cryomilling of prealloyed NiAl containing 53 at. % AJ was carried out to achieve high nitrogen levels. The consolidation of cryomilled powder by extrusion or hot pressing/hot isostatic pressing resulted in a fully dense NiAl-base composite containing 30 vol. % of inhomogeneously distributed, nanosized AlN particulate. The NiAl-30AlN composite exhibited the highest compression yield strengths at all temperatures between 300 and 1300 K as compared with other compositions of NiAl-AlN composite. The NiAl-30AlN specimens tested under compressive creep loading between 1300 and 1500 K also exhibited the highest creep resistance with very little surface oxidation indicating also their superior elevated temperature oxidation resistance. In the high stress exponent regime, the strength is proportional to the square root of the AlN content and in the low stress exponent regime, the influence of AlN content on strength appears to be less dramatic. The specific creep strength of this material at 1300 K is superior to a first generation Ni-base single crystal superalloy. The improvements in elevated temperature creep strength and oxidation resistance have been achieved without sacrificing the room temperature fracture toughness of the NiAl-base material. Based on its attractive combination of properties, the NiAl-30AlN composite is a potential candidate for advanced engine applications.