2,431 research outputs found

    Struktur Biaya dan Pendapatan Usaha Ternak Ayam Ras Pedaging Pola Kemitraan Makloon di Kabupaten Sukabumi (Studi Kasus: Peternak Mitra PT. X)

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    Salah satu komoditas ternak yang banyak diusahakan di Indonesia adalah ayam broiler. Mayoritas peternak ayam broiler memiliki kemampuan permodalan dan akses pasar yang kurang memadai sehingga memilih menjalankan usaha ternaknya melalui sistem kemitraan. Pola kemitraan dengan risiko rendah bagi peternak plasma adalah pola makloon karena pendapatan peternak tidak dipengaruhi oleh harga pasar. Berdasarkan hal tersebut, penelitian ini bertujuan untuk (1) menganalisis struktur biaya usaha ternak ayam ras pedaging pola makloon menurut skala usahanya, (2) menganalisis perbandingan pendapatan rata-rata peternak menurut skala usahanya. Metode analisis yang digunakan dalam penelitian ini yaitu analisis struktur biaya, R/C Ratio, Independent-Samples T Test, dan Uji Mann-Whitney. Hasil penelitian menunjukkan bahwa unit cost pada peternak skala I lebih tinggi dibandingkan dengan yang dikeluarkan peternak skala II sehingga pendapatan atas unit cost yang diperoleh peternak skala I lebih rendah dibandingkan peternak skala II. Nilai R/C Ratio peternak skala I juga lebih rendah dari peternak skala I. Hasil uji beda unit cost tunai dan total menunjukkan perbedaan yang signifikan antar skala usaha. Hasil uji Mann-Whitney pendapatan atas unit cost tunai dan total peternak skala I dan II juga menunjukkan perbedaan yang signifikan

    COMBINED EFFECTS OF TEMPERATURE AND HEAVY METALS ON THE PERFORMANCE OF THE GIANT SALMONFLY.

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    In many freshwater ecosystems, communities of aquatic insects are facing the combined stresses of warmer waters due to climate change and increased exposure to heavy metal toxicants. Although each stressor may threaten aquatic insects independently, they also likely interact in important ways to affect insect physiology and performance. Here we investigate this potential interaction using two populations of aquatic nymphs of the giant salmonfly, Pteronarcys californica, collected from adjacent rivers in Montana: naïve individuals from Rock Creek, a relatively pristine stream, and individuals from the Upper Clark Fork River, which has a history of heavy metal pollution and higher temperatures. We used a factorial design that exposed nymphs from the two rivers to one of two varying concentrations of metals (copper or lead) in combination with one of two temperatures (12 or 18 °C). We measured survival, growth, and upper critical temperature (CTMAX), as well as individual heavy metal concentration. Nymphs from both rivers exposed to the highest amounts of copper showed reduced survival and growth rates, and their CTMAX were reduced by up to 10 °C. By contrast, lead had little effect on survival, growth, or CTMAX of either population. These results suggest that acute exposure to heavy metals may reduce the ability of aquatic insects to withstand exposure to climate-induced warming

    ECO and RESOLVE: Galaxy Disk Growth in Environmental Context

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    We study the relationships between galaxy environments and galaxy properties related to disk (re)growth, considering two highly complete samples that are approximately baryonic mass limited into the high-mass dwarf galaxy regime, the Environmental COntext (ECO) catalog (data release herein) and the B-semester region of the REsolved Spectroscopy Of a Local VolumE (RESOLVE) survey. We quantify galaxy environments using both group identification and smoothed galaxy density field methods. We use by-eye and quantitative morphological classifications plus atomic gas content measurements and estimates. We find that blue early-type (E/S0) galaxies, gas-dominated galaxies, and UV-bright disk host galaxies all become distinctly more common below group halo mass ~10^11.5 Msun, implying that this low group halo mass regime may be a preferred regime for significant disk growth activity. We also find that blue early-type and blue late-type galaxies inhabit environments of similar group halo mass at fixed baryonic mass, consistent with a scenario in which blue early types can regrow late-type disks. In fact, we find that the only significant difference in the typical group halo mass inhabited by different galaxy classes is for satellite galaxies with different colors, where at fixed baryonic mass red early and late types have higher typical group halo masses than blue early and late types. More generally, we argue that the traditional morphology-environment relation (i.e., that denser environments tend to have more early types) can be largely attributed to the morphology-galaxy mass relation for centrals and the color-environment relation for satellites.Comment: 26 pages and 28 figures; v2 contains minor figure and text updates to match final published version in ApJ; ECO data table release now available at http://resolve.astro.unc.edu/pages/data.ph

    Orthoconic antiferroelectric liquid crystals for non-display applications

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    Antiferroelectric liquid crystals are attractive for microdisplay applications, because of their fast switching and wide viewing angle; however the pretransitional effect reduces the contrast of the display. As a promising alternative orthoconic antiferroelectric liquid crystals (OAFLC) with a cone angle of 90º provide a good dark state between crossed polarized independently of the cell rotation. These materials are properly surface stabilized in 1.5μm thick cell required for π retardation, which limits their use in display applications. In this work, new OAFLC mixtures have been surface stabilized in thick cells. This achievement may open a new area of OAFLC applications in photonic devices

    Haemophilus influenzae induces steroid-resistant inflammatory responses in COPD.

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    BACKGROUND: Chronic obstructive pulmonary disease (COPD) is an inflammatory disorder partially resistant to glucocorticoids. A reduced histone deacetylase (HDAC) activity has been proposed to explain this resistance. Haemophilus influenzae frequently colonizes the airways of COPD patients, where it enhances inflammation. The effects of Haemophilus influenzae on HDAC activity have not been investigated before. METHODS: The effects of the presence or absence of Haemophilus influenzae ex-vivo and in vitro were studied. To this end, we determined: (1) cytokine release in alveolar macrophages (AM) from 7 patients with COPD, 5 healthy smokers, 6 healthy non-smokers and (2) HDAC activity, nuclear factor kappa B (NF-κB) activation in a macrophage-like cell line (PMA-transformed U937 cells) co-cultured with epithelial cells. Experiments were repeated with dexamethasone (1 μM) and/or the HDAC enhancer theophylline (10 μM). RESULTS: Haemophilus influenzae induced a steroid-resistant inflammatory response in AM from COPD and controls and decreased HDAC activity, activated NF-κB and induced the secretion of several cytokines (IL-6, IL-8, IL-1β, IL-10 and TNF-α) (p < 0.001 for all comparisons) in the macrophage-like cell line. Dexamethasone reduced NF-κB activation but it did not modify HDAC activity. The addition of theophylline to dexamethasone increased HDAC activity and suppressed cytokine release completely, without modifying NF-κB activation. CONCLUSIONS: These results indicate that Haemophilus influenzae reduces HDAC activity and induces a NF-κB mediated inflammatory response that is only partially suppressed by glucocorticoids irrespective of having COPD. Yet, the latter can be fully restored by targeting HDAC activity

    Millimeter-Wave Line Ratios and Sub-beam Volume Density Distributions

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    We explore the use of mm-wave emission line ratios to trace molecular gas density when observations integrate over a wide range of volume densities within a single telescope beam. For observations targeting external galaxies, this case is unavoidable. Using a framework similar to that of Krumholz and Thompson (2007), we model emission for a set of common extragalactic lines from lognormal and power law density distributions. We consider the median density of gas producing emission and the ability to predict density variations from observed line ratios. We emphasize line ratio variations, because these do not require knowing the absolute abundance of our tracers. Patterns of line ratio variations have the prospect to illuminate the high-end shape of the density distribution, and to capture changes in the dense gas fraction and median volume density. Our results with and without a high density power law tail differ appreciably; we highlight better knowledge of the PDF shape as an important area. We also show the implications of sub-beam density distributions for isotopologue studies targeting dense gas tracers. Differential excitation often implies a significant correction to the naive case. We provide tabulated versions of many of our results, which can be used to interpret changes in mm-wave line ratios in terms of changes in the underlying density distributions.Comment: 24 pages, 16 figure, Accepted for publication in the Astrophysical Journal, two online tables temporarily available at http://www.astronomy.ohio-state.edu/~leroy.42/densegas_table2.txt and http://www.astronomy.ohio-state.edu/~leroy.42/densegas_table3.tx

    Psychological factors and future performance of football players:A systematic review with meta-analysis

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    Objectives: This systematic review had 3 key objectives: (1) to investigate whether psychological factors were associated with future football performance ( e.g., progression to professional football, better game statistics during the next season); (2) to critically review the methodological approaches used in the included studies and summarize the evidence for the current research question; (3) to provide guidelines for future studies. Design: Systematic ReviewMethods: Electronic databases (SPORTDiscus, PubMed and PsycINFO) and previously published systematic and scoping reviews were searched. Only prospective studies were considered for inclusion. Results: Eleven published studies that reported 39 effect sizes were included. Psychological factors; task orientation, task-oriented coping strategies and perceptual-cognitive functions had small effects on future performance in football (ds = 0.20-0.29). Due to high risk of bias there were low certainty of evidence for psychological factors relationship with future football performance. Conclusions: Psychological factors investigated showed small effects on future football performance, however, there was overall uncertainty in this evidence due to various sources of bias in the included studies. Therefore psychological factors cannot be used as a sole deciding factor in player recruitment, retention, release strategies, however it would appear appropriate to include these in the overall decision-making process. Future, studies with more appropriate and robust research designs are urgently needed to provide more certainty around their actual role

    bcl-2 Transgene Expression Inhibits Apoptosis in the Germinal Center and Reveals Differences in the Selection of Memory B Cells and Bone Marrow Antibody-Forming Cells

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    Immunization with T cell–dependent antigens generates long-lived memory B cells and antibody-forming cells (AFCs). Both populations originate in germinal centers and, predominantly, produce antibodies with high affinity for antigen. The means by which germinal center B cells are recruited into these populations remains unclear. We have examined affinity maturation of antigen-specific B cells in mice expressing the cell death inhibitor bcl-2 as a transgene. Such mice had reduced apoptosis in germinal centers and an excessive number of memory B cells with a low frequency of V gene somatic mutation, including those mutations encoding amino acid exchanges known to enhance affinity. Despite the frequency of AFCs being increased in bcl-2–transgenic mice, the fraction secreting high-affinity antibody in the bone marrow at day 42 remained unchanged compared with controls. The inability of BCL-2 to alter selection of bone marrow AFCs is consistent with these cells being selected within the germinal center on the basis of their affinity being above some threshold rather than their survival being due to a selective competition for an antigen-based signal. Continuous competition for antigen does, however, explain formation of the memory compartment
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