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Lipopolysaccharide (LPS) from Gram-negative bacteria induces an immune response and impairs reproduction through suppression of gonadotropin releasing hormone (GnRH), subsequently luteinizing hormone (LH) secretion. While there is evidence that acute inflammation inhibits kisspeptin, little is known about the impact of chronic inflammation on this key reproductive neuropeptide in livestock species. Thus, we sought to examine a central mechanism whereby LPS suppresses LH secretion in sheep. Twenty wethers were randomly assigned to one of five treatment groups: control (CON; n=4), single acute IV LPS dose (SAD; n=4), daily acute IV LPS dose (DAD; n=4), daily increasing IV LPS dose (DID; n=4), and chronic subcutaneous LPS dose (CSD; n=4). On Days 1 and 7, blood samples were collected every 12 minutes for 360 minutes using jugular venipuncture. Following blood collection on Day 7, all animals were euthanized, brain tissue was perfused with 4% paraformaldehyde, and hypothalamic blocks were removed and processed for immunohistochemistry. On Day 1, LH pulse frequency was significantly lower (p=0.02) in SAD (0.25 ± 0.1 pulses/hour), DAD (0.25 ± 0.1 pulses/hour), DID (0.35 ± 0.1 pulses/hour), and CSD (0.40 ± 0.1 pulses/hour) compared to CON (0.70 ±0.1 pulses/hour). On Day 7, only DID animals (0.35 ± 0.1 pulses/hour) had significantly lower (p=0.049) LH pulse frequency compared to controls (0.85 ± 0.1 pulse/hour). Furthermore, only DID animals (33.3 ± 10.9 cells/section/animal) had significantly fewer (p=0.001) kisspeptin-immunopositive cells compared to controls (82.6 ± 13.6 cells/section/animal). Taken together, we suggest that daily increasing doses of LPS is a powerful inhibitor of kisspeptin neurons in young male sheep and a physiologically relevant model to examine the impact of chronic inflammation on the reproductive axis in livestock., Competing Interests: Declaration of competing interest The authors report no conflicts of interest to disclose., (Copyright © 2024. Published by Elsevier Inc.)

Human performance in complex multiple-task environments depends critically on the interplay between cognitive control and cognitive capacity. In this paper we propose a tractable computational model of how cognitive control and capacity influence the speed and accuracy of decisions made in the event-based prospective memory (PM) paradigm, and in doing so test a new quantitative formulation that measures two distinct components of cognitive capacity (gain and focus) that apply generally to choices among two or more options. Consistent with prior work, individuals used proactive control (increased ongoing task thresholds under PM load) and reactive control (inhibited ongoing task accumulation rates to PM items) to support PM performance. Individuals used cognitive gain to increase the amount of resources allocated to the ongoing task under time pressure and PM load. However, when demands exceeded the capacity limit, resources were reallocated (shared) between ongoing task and PM processes. Extending previous work, individuals used cognitive focus to control the quality of processing for the ongoing and PM tasks based on the particular demand and payoff structure of the environment (e.g., higher focus for higher priority tasks; lower focus under high time pressure and with PM load). Our model provides the first detailed quantitative understanding of cognitive gain and focus as they apply to evidence accumulation models, which - along with cognitive control mechanisms - support decision-making in complex multiple-task environments., (Crown Copyright © 2019. Published by Elsevier B.V. All rights reserved.)

The aim of this study was to examine relationships among temperament, endocrinology, and reproductive parameters of bulls enrolled in an 84-day performance test. Angus bulls (n = 60) were housed in six pens grouped by age and weight. Pen scores (PS; 1 = docile to 5 = very aggressive) were assigned on Days -1, 27, 55, and 83 of the performance test. On the following day, blood and hair samples were collected, and body weight (BW) and exit velocity (EV) were recorded. Bulls were split into two categories based on; Day -1 PS (PScalm = PS 1 or 2; PSexcitable = PS 3 or 4) and Day 0 EV (EVcalm = slowest 20 bulls; EVexcitable = fastest 20 bulls). Cortisol and testosterone concentrations in serum and hair did not differ (P > 0.10) between PS or EV temperament categories. Sampling day differences (P < 0.01) occurred for serum testosterone, hair cortisol, and hair testosterone concentration; however, serum cortisol concentration did not differ (P > 0.10) over the sampling days. Serum testosterone concentration increased (P < 0.01) from Day 0 to 28, decreased from Day 28 to 56, but Day 84 did not differ from Day 0, 28, or 56. Hair cortisol concentration was greatest (P < 0.01) on Day 0, decreased from Day 28 to 56 but did not differ from Day 56 to 84. Hair testosterone concentration was greatest (P < 0.01) on Day 0 and remained constant from Day 28 to 84. Bulls categorized as PScalm had a greater (P < 0.01) percentage of normal sperm and secondary defects (P < 0.01) when compared with PSexcitable bulls. However, EVcalm bulls had fewer (P < 0.01) primary defects but more (P < 0.01) secondary defects than EVexcitable bulls. In conclusion, bulls exhibited physiological evidence of acclimation during the test as indicated by a reduction in hair cortisol concentration. In addition, the ability of the bulls to acclimate while residing at the testing center may have contributed to little differences observed during the breeding soundness examination portion of the performance test., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Serum prolactin (PRL) and testosterone concentrations, body weight, body composition, semen quality, and semen freezing potential for bulls grazing the toxic tall fescue (Lolium arundinaceum [Schreb.] Darbysh. = Schedonorous arundinaceum [Schreb.] Dumort.) cultivar Kentucky 31 (E+) compared with a novel endophyte cultivar lacking ergot alkaloids (E-) were evaluated. Angus bulls were allotted to treatment (Day 0) and grazed E+ or E- for 155 days. Treatment-by-day interaction was significant (P < 0.05) for serum PRL concentrations with E+treated bulls exhibiting reduced PRL values compared with E- control bulls, but no differences were observed for serum testosterone concentrations (P > 0.05). Further, bulls on the E+ treatment exhibited decreased total gain, average daily gain, and body weight by Day 140 (P < 0.05) compared with the E- bulls. Rump muscle depth was lower because the treatment in bulls grazing E+ compared with E- (P < 0.05) and intramuscular fat in the E- bulls compared with the E+ group was higher by Day 155 (P < 0.05). Analysis of ejaculates showed significant treatment × day effects for sperm concentration with lower values observed for bulls on the E+ treatment (P < 0.05). The percent normal morphology was reduced in ejaculates from E+ bulls compared with E- bulls (P < 0.05), and the difference was due to an increase in abnormal sperm present in the E+ ejaculates from Day 84 to 140 (P < 0.05). In addition, spermatozoa motility and progressive motility were decreased on thawing in semen samples from E+ bulls compared with E- bulls (P < 0.05)., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: Chronic hepatitis C (CHC) is the most common blood-borne infection in the United States, but little is known about illness uncertainty in these patients., Objective: The authors examined the constructs of illness uncertainty., Method: In this cross-sectional study, Mishel's Uncertainty in Illness Scale was used to examine these constructs (ambiguity, complexity, inconsistency, unpredictability) and their relationships with fatigue, pain, depressive symptoms, comorbidity, and quality of life (QOL) in 126 CHC patients undergoing a watchful-waiting protocol., Results: The Ambiguity subscale had the strongest relationships with depressive symptoms, QOL, and fatigue, and three of the four subscales were significantly correlated with pain., Conclusion: The results suggest targets for patient self-management interventions.

Objective: The objective of this study was to determine whether medical students' attendance at a clinic designed for pregnant substance users would yield changes in their attitudes toward the special needs of this population., Study Design: This prospective study involved 104 consecutive third-year students rotating on our obstetrics-gynecology clerkship. Students were assigned to attend either a half day prenatal clinic designed specifically for women with substance use disorders during the first 4 weeks (study group) or during the second 4 weeks (control group). Each answered a confidential 24-question survey (using a 5-point scale from "strongly agree" to "strongly disagree"), dealing with comfort levels and attitudes, at the beginning and midway points of the 8-week clerkship. Student t tests were used for comparisons of averaged scores., Results: At the beginning of the clerkship, no differences were found between the study (n = 52) and control groups (n = 52) in their responses to the survey. Regardless of gender, students who attended the clinic reported they became more comfortable in talking with patients about their substance use (P < .001) and more nonjudgmental in treating these patients (P < .02). Compared with before the clerkship, the control group became less comfortable in talking with these patients about their habits (P < .01), less aware about the prevalence of substance abuse during pregnancy (P < .02), and less aware about the efficacy of counselors (P < .05)., Conclusion: Medical students became more comfortable and better informed about pregnant women with substance use disorders after attending a clinic dedicated toward this population's special needs.