1,193 research outputs found

    Compressibility and Hydraulic Conductivity of Zeolite-Amended Soil-Bentonite Backfills

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    The effect of zeolite amendment for enhanced sorption capacity on the consolidation behavior and hydraulic conductivity, k, of a typical soil-bentonite (SB) backfill for vertical cutoff walls was evaluated via laboratory testing. The consolidation behavior and k of test specimens containing fine sand, 5.8 % (dry wt.) sodium bentonite, and 0, 2, 5, or 10 % (dry wt.) of one of three types of zeolite (clinoptilolite, chabazite-lower bed, or chabazite-upper bed) were measured using fixed-ring oedometers, and k also was measured on separate specimens using a flexible-wall permeameter. The results indicated that addition of a zeolite had little impact on either the consolidation behavior or the k of the backfill, regardless of the amount or type of zeolite. For example, the compression index, Cc, for the unamended backfill specimen was 0.24, whereas values of Cc for the zeolite amended specimens were in the range 0.19 ≤ Cc ≤ 0.23. Similarly, the k for the unamended specimen based on flexible-wall tests was 2.4 x 10-10 m/s, whereas values of k for zeolite amended specimens were in the range 1.2 x 10-10 ≤ k ≤ 3.9 x 10-10 m/s. The results of the study suggest that enhancing the sorption capacity of typical SB backfills via zeolite amendment is not likely to have a significant effect on the consolidation behavior or k of the backfill, provided that the amount of zeolite added is small (≤ 10 %)

    Effects of breed of sire on carcass composition and sensory traits of lamb

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    This experiment was conducted to compare meat quality and carcass composition of a diverse sampling of sheep breeds. Finnsheep, Romanov, Dorper, White Dorper, Katahdin, Rambouillet, Suffolk, Texel, Dorset, and Composite (½ Columbia rams to ¼ Hampshire × ¼ Suffolk) rams were mated to mature Composite ewes. Lambs (n = 804) were reared intensively, grain fi nished, and serially harvested over a 63-d period. Average harvest age was 216 d and average HCW was 30.7 kg. At a common harvest age, progeny of Suffolk sires were heavier than progeny of all other breeds (P \u3c 0.05) and their carcasses were heavier (P \u3c 0.05) than progeny of all other breeds, except White Dorper and Dorper. Progeny of Finnsheep and Romanov sires had lighter (P \u3c 0.05) carcasses than progeny of all other breeds. Progeny of Texel, Suffolk, White Dorper, and Dorper sires had larger (P \u3c 0.05) LM area than all other breeds. Progeny of Finnsheep and Romanov sires had smaller (P \u3c 0.05) LM area than all other breeds. Fat thickness at the 12th rib was greater (P \u3c 0.05) for progeny of Dorper sires than those of all other breeds, except White Dorper and Katahdin. Fat thickness at the 4th sacral vertebrae was greater (P \u3c 0.05) for progeny of White Dorper and Dorper sires than those of all other breeds. On a carcass weight-constant basis, progeny of Suffolk sires had a lesser (P \u3c 0.05) percentage of ether-extractable carcass fat than progeny of all other breeds, except Texel. Regardless of harvest endpoint (age-constant or HCW-constant), LM of progeny of Finnsheep and Romanov sires contained a greater (P \u3c 0.05) percentage of intramuscular fat and received greater (P \u3c 0.05) marbling scores than Rambouillet, Suffolk, Texel, Dorset, or Composite. Regardless of harvest endpoint, progeny of Finnsheep, Romanov, and Katahdin sires had smaller LM slice shear force values and greater trained sensory panel tenderness ratings at 7 d postmortem than did progeny of Composite, Suffolk, and Dorset sires (P \u3c 0.05). At an age-constant basis, small differences (P \u3c 0.05) were observed among breeds for lamb flavor intensity scores; however, when means were adjusted to a carcass weight-constant basis, breed of sire did not affect flavor intensity or off-flavor scores. These results document that each breed has relative strengths and weaknesses across traits, and that no single breed excels for all growth, carcass, and sensory traits

    Biochemical and Structural Effects of Rigor Mortis-Accelerating Treatments in Broiler \u3ci\u3ePectoralis\u3c/i\u3e

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    This study was conducted to elucidate the mechanism of action of two selected rigor mortis-accelerating treatment systems employed in the prevention of the toughness associated with early-harvested (1 h post-mortem) broiler Pectoralis muscle. The treatments included 14 min of low voltage electrical stimulation (110 V, 1 A, pulsing 1 s on and 1 s off) combined with high temperature conditioning (39 C) and muscle tensioning (LV + HTC + MT); a 15-s high voltage stimulation (440 V, 1 A pulsing 2 s on and 1 s off) combined with muscle tensioning (HV + MT); and a control simulating commercial broiler processing practices. The rigor-accelerating treatments reduced pH and increased R-value (inosine:adenosine ratio) at 1 h post-mortem, but only the LV + HTC + MT treatment reduced sarcomere shortening. Both rigor treatments reduced the amount of measurable myofibrillar fragmentation. Cathepsin B and B + L activities were not affected by the rigor treatments. Calpain I activity was not detectable in any 24-h post-mortem sample. Calpain II activity at 24 h post-mortem was greater in muscles receiving HV + MT than from the LV + HTC + MT or control carcasses, but was reduced in all muscles by 24 h postmortem. An SDS-PAGE indicated a 30-kDa polypeptide that was absent at death and appeared in control and LV + HTC + MT muscles but to a lesser extent in HV + MT muscles. These results suggested that the LV + HTC + MT treatment has a greater tenderizing effect than the HV + MT treatment because the former achieves a better balance between reduced sarcomere shortening and myofibrillar fragmentation

    Biochemical and Structural Effects of Rigor Mortis-Accelerating Treatments in Broiler \u3ci\u3ePectoralis\u3c/i\u3e

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    This study was conducted to elucidate the mechanism of action of two selected rigor mortis-accelerating treatment systems employed in the prevention of the toughness associated with early-harvested (1 h post-mortem) broiler Pectoralis muscle. The treatments included 14 min of low voltage electrical stimulation (110 V, 1 A, pulsing 1 s on and 1 s off) combined with high temperature conditioning (39 C) and muscle tensioning (LV + HTC + MT); a 15-s high voltage stimulation (440 V, 1 A pulsing 2 s on and 1 s off) combined with muscle tensioning (HV + MT); and a control simulating commercial broiler processing practices. The rigor-accelerating treatments reduced pH and increased R-value (inosine:adenosine ratio) at 1 h post-mortem, but only the LV + HTC + MT treatment reduced sarcomere shortening. Both rigor treatments reduced the amount of measurable myofibrillar fragmentation. Cathepsin B and B + L activities were not affected by the rigor treatments. Calpain I activity was not detectable in any 24-h post-mortem sample. Calpain II activity at 24 h post-mortem was greater in muscles receiving HV + MT than from the LV + HTC + MT or control carcasses, but was reduced in all muscles by 24 h postmortem. An SDS-PAGE indicated a 30-kDa polypeptide that was absent at death and appeared in control and LV + HTC + MT muscles but to a lesser extent in HV + MT muscles. These results suggested that the LV + HTC + MT treatment has a greater tenderizing effect than the HV + MT treatment because the former achieves a better balance between reduced sarcomere shortening and myofibrillar fragmentation

    How willing are you to accept sexual requests from slightly unattractive to exceptionally attractive imagined requestors?

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    This is the post print version of the article. The official published version can be accessed from the link below.In their classic study of differences in mating strategies (Clark & Hatfield, 1989), men and women demonstrated a striking difference in interest in casual sex. The current study examined the role of requestor physical attractiveness (slightly unattractive, moderately attractive and exceptionally attractive) on men's and women's willingness to accept three different requests (go out, come to apartment, go to bed) in a questionnaire study. We tested two hypotheses, using a sample of 427 men and 443 women from three countries. Hypothesis 1 states that men, relative to women, will demonstrate a greater willingness to accept the “come to apartment” and “go to bed” requests but not the “go out” request for all three levels of requestor attractiveness. This hypothesis reflects Clark and Hatfield's (1989) main findings. Hypothesis 2 states that the physical attractiveness of a potential partner will have a greater effect on women's than on men's willingness to accept all three requests, and particularly for the explicit request for casual sex. The results partially supported Hypothesis 1 and fully supported Hypothesis 2. The discussion highlights limitations of the current research and presents directions for future research

    Selection for genetic markers in beef cattle reveals complex associations of thyroglobulin and casein1-S1 with carcass and meat traits

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    Genetic markers in casein (CSN1S1) and thyroglobulin (TG) genes have previously been associated with fat distribution in cattle. Determining the nature of these genetic associations (additive, recessive, or dominant) has been diffi cult, because both markers have small minor allele frequencies in most beef cattle populations. This results in few animals homozygous for the minor alleles. Selection to increase the frequencies of the minor alleles for 2 SNP markers in these genes was undertaken in a composite population. The objective was to obtain better estimates of genetic effects associated with these markers and determine if there were epistatic interactions. Selection increased the frequencies of minor alleles for both SNP from0.10). Additive, dominance, and epistatic SNP association effects were estimated from genotypic effects for adjusted fat thickness and predicted meat tenderness. Adjusted fat thickness showed a dominance association with TG SNP (P \u3c 0.06) and an epistatic additive CSN1S1 Ă— additive TG association (P \u3c 0.03). For predicted meat tenderness, heterozygous TG meat was more tender than meat from either homozygote (P \u3c 0.002). Dominance and epistatic associations can result in different SNP allele substitution effects in populations where SNP have the same linkage disequilibrium with causal mutations but have different frequencies. Although the complex associations estimated in this study would contribute little to within-population selection response, they could be important for marker-assisted management or reciprocal selection schemes

    What Happens to bone health during and after spaceflight?

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    Weightless conditions of space flight accelerate bone loss. There are no reports to date that address whether the bone that is lost during spaceflight could ever be recovered. Spaceinduced bone loss in astronauts is evaluated at the Johnson Space Center (JSC) by measurement of bone mineral density (BMD) by Dual-energy x-ray absorptiometry (DXA) scans. Astronauts are routinely scanned preflight and at various time points postflight (greater than or equal to Return+2 days). Two sets of BMD data were used to model spaceflight-induced loss and skeletal recovery in crewmembers following long-duration spaceflight missions (4-6 months). Group I was from astronauts (n=7) who were systematically scanned at multiple time points during the postflight period as part of a research protocol to investigate skeletal recovery. Group II came from a total of 49 sets of preflight and postflight data obtained by different protocols. These data were from 39 different crewmembers some of whom served on multiple flights. Changes in BMD (between pre- and postflight BMD) were plotted as a function of time (days-after-landing); plotted data were fitted to an exponential equation which enabled estimations of i) BMD change at day 0 after landing and ii) the number of days by which 50% of the lost bone is recovered (half-life). These fits were performed for BMD of the lumbar spine, trochanter, pelvis, femoral neck and calcaneus. There was consistency between the models for BMD recovery. Based upon the exponential model of BMD restoration, recovery following long-duration missions appears to be substantially complete in crewmembers within 36 months following return to Earth

    Why the adaptationist perspective must be considered: The example of morbid jealousy

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    Abstract: We describe Delusional Disorder-Jealous Type ("morbid jealousy") with the adaptationist perspective used by Darwinian psychiatrists and evolutionary psychologists to explain the relatively common existence and continued prevalence of mental disorders. We then apply the "harmful dysfunction" analysis to morbid jealousy, including
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