766 research outputs found

    Factors affecting reproductive performance of dairy cows in a pasture-based, automatic milking system research farm: a retrospective, single-cohort study

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    A retrospective single cohort study was conducted to identify production and health factors associated with reproductive performance in a pasture-based automatic milking system research farm. The calving system of this herd shifted from split calving to year round calving gradually during the study period. Data from 365 cows with 798 lactations were analysed in the study. Reproductive outcome variables of interest were intervals from calving to first oestrus, to first insemination, and to conception as well as number of inseminations per conception, probability of submission for insemination by 80 days in milk, probability of conception by 100 days in milk and probability of conception at first insemination. Production factors (milk yield and its composition; milking frequency), record of periparturient disease, parity and season of calving were considered as predictor variables. The associations between predictor and outcome variables were assessed by multivariable linear regression, logistic regression and survival analyses for quantitative, binary and time-to-event outcomes, respectively. Average milk yield and milking frequency during 100 days in milk were not significantly associated with any of the reproductive measures. The likelihood of conception by 100 days in milk decreased gradually with year of automatic milking systems commissioning. Cows calved in autumn were 43% (hazard ratio: 1.43, P < 0.05) more likely to conceive compared to cows that calved in summer. Multiparous cows were more likely (P < 0.05) to be recorded for oestrus compared to primiparous cows. Twinning was negatively associated with the reproductive outcomes measured in the automatic milking systems research herd. Milk yield and milking frequency during 100 days in milk had no effect on reproductive measures in the pasture-based automatic milking system research herd. Key words: Reproduction, Automatic Milking System, Pasture-Based Syste

    Factors affecting reproductive performance of dairy cows in a pasture-based, automatic milking system research farm: a retrospective, single-cohort study

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    A retrospective single cohort study was conducted to identify production and health factors associated with reproductive performance in a pasture-based automatic milking system research farm. The calving system of this herd shifted from split calving to year round calving gradually during the study period. Data from 365 cows with 798 lactations were analysed in the study. Reproductive outcome variables of interest were intervals from calving to first oestrus, to first insemination, and to conception as well as number of inseminations per conception, probability of submission for insemination by 80 days in milk, probability of conception by 100 days in milk and probability of conception at first insemination. Production factors (milk yield and its composition; milking frequency), record of periparturient disease, parity and season of calving were considered as predictor variables. The associations between predictor and outcome variables were assessed by multivariable linear regression, logistic regression and survival analyses for quantitative, binary and time-to-event outcomes, respectively. Average milk yield and milking frequency during 100 days in milk were not significantly associated with any of the reproductive measures. The likelihood of conception by 100 days in milk decreased gradually with year of automatic milking systems commissioning. Cows calved in autumn were 43% (hazard ratio: 1.43, P < 0.05) more likely to conceive compared to cows that calved in summer. Multiparous cows were more likely (P < 0.05) to be recorded for oestrus compared to primiparous cows. Twinning was negatively associated with the reproductive outcomes measured in the automatic milking systems research herd. Milk yield and milking frequency during 100 days in milk had no effect on reproductive measures in the pasture-based automatic milking system research herd. Key words: Reproduction, Automatic Milking System, Pasture-Based Syste

    In vitro clonal propagation of locally cultivated pink colour Gladiolus var. Neelima through Cormel-sprout culture

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    Micropropagation provides an economic advantage for the propagation of a particular crop like gladiolus, a beautiful flowering plant which emits expression of love. Propagation by conventional method is a slow process and pathogen keep on accumulation generation after generation which reduces yield and quality of flower and also generates insufficient propagules. An efficient propagation system could overcome those variabilities and meet the increasing demand of propagules production for the growing of gladiolus in the country while it is an exporting plant in Bangladesh. Moreover, establishment of a plant regeneration system through direct organogenesis or via callus is also a prerequisite to further in vitro genetic manipulation of the cultivar. Demand for disease free planting materials is increasing day by day and crop like vegetatively propagated plant is an appropriate means to generate propagules through in vitro techniques. Production of sufficient numbers of plants of a unique genotype is possible using in vitro culture system. In this study, the effect of various concentrations and combinations of plant growth regulators for in vitro regeneration of gladiolus was described using cormel-sprout as explants. However, an efficient in vitro plant regeneration protocol in locally cultivated pink colour Gladiolus var. Neelima was established on MS media with various hormonal supplements using cormel-sprout as explants. Ninety (90) percent of the explants responded for shooting on 0.5 mg/L BA + 0.5 mg/L Kin within the culture initiation period of 90 days. The average number of shoot per explants was 8 ±1.20 and the average shoot length of 12.40 ±2.15 cm were observed in this medium. Shoots are rooted well when they were excised individually and implanted on half strength of MS medium supplemented with 1.0 mg/l IBA, in which 90% of the shoot induced roots. The average number of root per shoot was 10 ± 1.20 and the average root length of 8.50 ± 1.25 cm were observed in this medium after culture of 30 days. Eighty (80) percent of the in vitro raised plantlets were survived in the natural environment

    A blind hierarchical coherent search for gravitational-wave signals from coalescing compact binaries in a network of interferometric detectors

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    We describe a hierarchical data analysis pipeline for coherently searching for gravitational wave (GW) signals from non-spinning compact binary coalescences (CBCs) in the data of multiple earth-based detectors. It assumes no prior information on the sky position of the source or the time of occurrence of its transient signals and, hence, is termed "blind". The pipeline computes the coherent network search statistic that is optimal in stationary, Gaussian noise, and allows for the computation of a suite of alternative statistics and signal-based discriminators that can improve its performance in real data. Unlike the coincident multi-detector search statistics employed so far, the coherent statistics are different in the sense that they check for the consistency of the signal amplitudes and phases in the different detectors with their different orientations and with the signal arrival times in them. The first stage of the hierarchical pipeline constructs coincidences of triggers from the multiple interferometers, by requiring their proximity in time and component masses. The second stage follows up on these coincident triggers by computing the coherent statistics. The performance of the hierarchical coherent pipeline on Gaussian data is shown to be better than the pipeline with just the first (coincidence) stage.Comment: 12 pages, 3 figures, accepted for publication in Classical and Quantum Gravit

    Efficacy of Flaxseed Flour as Bind Enhancing Agent on the Quality of Extended Restructured Mutton Chops

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    Consumers have become very conscious about their nutrition and well being due to changes in their socio-economic lifestyle and rapid urbanization. Therefore, development of technology for production of low cost and functional meat products is urgently required. One such approach is innovative restructuring technology in which binding of meat pieces still remains the main challenge and extension of product is generally associated with poor binding and texture. Thus, the present study was envisaged as an attempt to solve this problem by the incorporation of flaxseed flour (FF) as bind enhancing agent. The FF was used at three different levels viz., 0.5%, 1%, and 1.5% to replace lean meat in pre-standardized restructured mutton chops formulation. The products were subjected to analysis for physico-chemical, sensory and textural properties. Cooking yield, moisture percentage and fat percentage increased with increase in the level of incorporation of FF, however, protein percent and pH decreased with increase in the level of incorporation. Shear force value of product incorporated with 1.5% FF was significantly higher (p<0.01) than control and product containing 0.5% FF level. Among the sensory attributes, product with 1% flaxseed flour showed significantly higher values (p<0.05) for general appearance, binding, texture and overall acceptability. Hardness showed significant increasing (p<0.01) values with increasing levels of incorporation of flaxseed flour, however all other parameters of texture profile analysis showed a decreasing trend. On the basis of sensory scores and physico-chemical properties, the optimum incorporation level of FF was adjudged as 1%. Products incorporated with optimum level of flaxseed flour (1%) were also assessed for water activity and microbiological quality during the storage period of 15 days. It was found that the extended restructured product could be safely stored under refrigeration (4°C±1°C) in low density polyethylene (LDPE) pouches for 15 days without marked deterioration in sensory and microbiological quality. Thus, it was concluded that flaxseed flour can be used as a good bind enhancing agent in extended restructured meat products at an economic cost

    Shelf life evaluation of restructured chicken meat blocks extended with sorghum flour and potato at refrigerated storage (4±1•C)

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    Abstract This study was conducted to evaluate the Shelf life of restructured chicken meat blocks extended with sorghum flour and potato at refrigerated storage (4±1•C). Sorghum flour (1:1 hydration, w/w) at 9% level and potato (boiled and mashed) at 6% level were incorporated by replacing the lean meat in pre-standardized formulation. Storage quality with respect to physico-chemical [pH and Thiobarbituric Acid (TBA) value], microbiological [Psychrophilic count (PC), Total plate count (TPC) and coliform count] and sensory properties of control and extended products were studied. The products were aerobically packaged in low density polyethylene (LDPE) pouches and analysed at regular interval of 0, 5, 10 and 15 days during refrigerated storage (4±1•C). The storage period did not bring about any significant changes in pH of the products but TBA values, PC and TPC showed linear increasing trend from 0 to 15 th day of refrigerated storage in treatment products as well as control. Mesophilic and psychrotrophic counts did not exceed log 10 3.12 and 2.98 cfu/g, log 10 2.86 and 2.63 cfu/g, log 10 2.63 and 2.95 cfu/g for control, SF and potato treated RCMB, respectively. Coliforms were not detected in control and treated RCMB during the storage period of 15 days. The sensory scores of treated samples and control for appearance, flavour, binding, texture, juiciness and overall acceptability showed a progressive decline with increase in storage period but the scores were rated above good. The products retained good to very good acceptability for 15 days without any marked loss of physico-chemical, microbiological and sensory quality

    Resolution of the phylogenetic relationship of the vulnerable flesh-footed shearwater (Ardenna carneipes) seabird using a complete mitochondrial genome

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    Flesh-footed shearwater (Ardenna carneipes) is recognized as vulnerable seabird species in Western Australia and New South Wales, Australia, and its genetic variability and a well-resolved phylogeny is imperative for the species’ conservation. Here, we report the first sequenced mitogenome of the Australian A. carneipes. The mitogenome of A. carneipes was 16,370 bp in total length and encompassed 13 protein-coding genes, two ribosomal RNAs, 22 transfer RNAs, and one non-coding region (D-loop). All of the genes were encoded on the H-strand with the exception of ND6 and eight tRNAs, which is a conserved pattern of the mitogenome for other vertebrates. The mitogenome of A. carneipes was dominated by higher AT (56.5%) than GC (43.5%) content. In the resulting phylogenetic tree using complete mitogenome sequences, flesh-footed shearwater and gray petrel (Procellaria cinerea) grouped together despite the high genetic distance (11.0%) between them, belonging to family Procellariidae. However, the phylogenetic tree was consistent with a previous study using partial nucleotide sequences of the cytochrome b gene. These results highlight that further mitogenome sequences will be required from the closely related species under the genus Ardenna to delineate well-resolved phylogenetic classification at the genus and or species level. The present study provides a reference mitochondrial genome of flesh-footed shearwater for further molecular studies

    Slow Light Propagation in a Thin Optical Fiber via Electromagnetically Induced Transparency

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    We propose a novel configuration that utilizes electromagnetically induced transparency (EIT) to tailor a fiber mode propagating inside a thin optical fiber and coherently control its dispersion properties to drastically reduce the group velocity of the fiber mode. The key to this proposal is: the evanescent-like field of the thin fiber strongly couples with the surrounding active medium, so that the EIT condition is met by the medium. We show how the properties of the fiber mode is modified due to the EIT medium, both numerically and analytically. We demonstrate that the group velocity of the new modified fiber mode can be drastically reduced (approximately 44 m/sec) using the coherently prepared orthohydrogen doped in a matrix of parahydrogen crystal as the EIT medium.Comment: 10 pages in two column RevTex4, 6 Figure

    A comprehensive model of gain recovery due to unipolar electron transport after a short optical pulse in quantum cascade lasers

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    We have developed a comprehensive model of gain recovery due to unipolar electron transport after a short optical pulse in quantum cascade lasers (QCLs) that takes into account all the participating energy levels, including the continuum, in a device. This work takes into account the incoherent scattering of electrons from one energy level to another and quantum coherent tunneling from an injector level to an active region level or vice versa. In contrast to the prior work that only considered transitions to and from a limited number of bound levels, this work include transitions between all bound levels and between the bound energy levels and the continuum. We simulated an experiment of S. Liu et al., in which 438-pJ femtosecond optical pulses at the device’s lasing wavelength were injected into an In0:653Ga0:348As=In0:310Al0:690As QCL structure; we found that approximately 1% of the electrons in the bound energy levels will be excited into the continuum by a pulse and that the probability that these electrons will be scattered back into bound energy levels is negligible, 104. The gain recovery that is predicted is not consistent with the experiments, indicating that one or more phenomena besides unipolar electron transport in response to a short optical pulse play an important role in the observed gain recovery
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