463 research outputs found

    Analysis of First-Time Completion in the Field Service Environment

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    First-time completion is an important measure of service quality and efficiency in the field service industry. Customers call upon field service providers to repair their equipment in a timely manner so it can be put back into service for their business demands. Responsiveness can be measured through first-time completion and is defined as completing the repair on the first visit of a service call. This research is exploring the first-time completion in the forklift service industry. This research found the primary factors that impact first-time completion percentage in this industry include parts on hand, parts backorder process, technician experience, and anticipating service demands

    A review of Multi-Agent Simulation Models in Agriculture

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    Multi-Agent Simulation (MAS) models are intended to capture emergent properties of complex systems that are not amenable to equilibrium analysis. They are beginning to see some use for analysing agricultural systems. The paper reports on work in progress to create a MAS for specific sectors in New Zealand agriculture. One part of the paper focuses on options for modelling land and other resources such as water, labour and capital in this model, as well as markets for exchanging resources and commodities. A second part considers options for modelling agent heterogeneity, especially risk preferences of farmers, and the impacts on decision-making. The final section outlines the MAS that the authors will be constructing over the next few years and the types of research questions that the model will help investigate.multi-agent simulation models, modelling, agent-based model, cellular automata, decision-making, Crop Production/Industries, Environmental Economics and Policy, Farm Management, Land Economics/Use, Livestock Production/Industries,

    The Role of Androgens in Testicular Development and Dysgenesis

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    Disorders of male reproductive health which manifest at birth (cryptorchidism, hypospadias) or in young adulthood (testicular germ cell cancer and low sperm counts), are common and may be increasing in incidence. These disorders have a common fetal origin and share risk factors; consequently they are hypothesized to comprise a testicular dysgenesis syndrome (TDS). TDS arises when maldevelopment (dysgenesis) of the fetal testis results in hormonal malfunctions and abnormal development and function of the somatic cells. It is thought that the suppressed intratesticular testosterone levels associated with TDS may account for subsequent low sperm counts, via a reduction in perinatal Sertoli cell proliferation/number. Sertoli cells do not express androgen receptors (AR) in fetal life in the human or rat, so it is hypothesised that any androgen effects on Sertoli cell number occur indirectly, via the AR positive peritubular myoid cells. Evidence from the di (n‐butyl) phthalate (DBP)‐treated rat model for TDS suggests that reduced androgen action may play a role in testicular dysgenesis as in patients with complete androgen insensitivity syndrome (CAIS; ‘testicular feminization’), in whom focal areas of testicular dysgenesis have been reported. The studies in this thesis sought to establish if reduced androgen levels/action in the fetal rat testis contribute to putative testicular dysgenetic features, namely reduced Sertoli cell number, occurrence of multinucleated gonocytes or abnormal aggregation of fetal Leydig cells, the precursor of focal dysgenesis. Pregnant rats were exposed to treatments or co‐treatments expected to manipulate testicular testosterone levels (DBP, testosterone propionate; TP) or action (flutamide, DMBA) or to induce intrauterine growth restriction (dexamethasone), another risk factor for TDS. The aforementioned endpoints were analysed in fetal testes and related to testicular testosterone levels and peripheral androgen action (anogenital distance). The same endpoints were evaluated in mice with inactivation of the androgen receptor (tfm or ARKO mice). As androgen action is assumed to be mediated indirectly, via the peritubular myoid cells, changes in peritubular myoid cell number and function were investigated in testes with suppressed androgens. In vitro studies were also used to investigate the role of androgens in Sertoli cell proliferation. Fetal rat testis explants were cultured with various chemicals designed to manipulate androgen action and Sertoli cell proliferation. Potential non‐androgen related mechanisms of DBP action were investigated using Taqman RT‐PCR to determine the mRNA expression of key developmental genes after exposure to DBP. Sertoli cell number was reduced after exposure to treatments that reduced testicular testosterone levels, i.e. DBP alone or as a co‐treatment, TP and dexamethasone. Sertoli cell numbers in ARKO mice were also significantly reduced. The occurrence of multinucleated gonocytes and large Leydig cell clusters were induced after exposure to DBP, alone or as a co‐treatment, but not after exposure to TP or dexamethasone, and these dysgenetic endpoints did not occur either in tfm or ARKO mice. Rats exposed in utero to DBP have reduced testicular testosterone levels, however peritubular myoid cell number was unaffected by DBP, though AR expression in the peritubular myoid cells was delayed, and laminin and vimentin expression in Sertoli cells was altered after DBP exposure. DMRT‐1 and DAX‐1 mRNA expression levels were significantly reduced after DBP exposure, but this reduction was no longer evident once mRNA expression was corrected for Sertoli cell number. In conclusion, these studies provide strong evidence that androgens play a role in regulation of Sertoli cell number/proliferation, and this is supported by a comparable reduction in Sertoli cell number in ARKO and tfm mice. However, since the treatments that reduce testicular testosterone in the rat, may also have a direct affect on the Sertoli cells, this alternate mechanism of action cannot be ruled out, and the administration of a treatment that reduces testicular testosterone without directly affecting Sertoli cells is required. These studies also show that reduced testicular testosterone levels are associated with multinucleated gonocyte formation and fetal Leydig cell aggregation, although this evidence it is not supported by parallel findings from the TP and dexamethasone exposed rats or the ARKO and tfm mice, as neither of these endpoints were identified as being affected in these animals. Aside from the delay in AR expression, there were no obvious changes in peritubular myoid cell number or the peritubular myoid cell markers examined in testes deprived of androgens, although there are other markers that could be investigated. mRNA analysis of the developmental genes investigated after DBP exposure, demonstrated no change in expression after correction for Sertoli cell number, suggesting that they do not play a role in the dysgenetic features observed in DBP exposed testes

    The Effect of Oral Contraceptive Pill Use on Knee Joint Laxity in Women

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    Schultz et al. (2004) demonstrated that 63% of the change in knee joint laxity (KJL) during a menstrual cycle was due to associated fluctuations in sex hormone levels. Use of oral contraceptives modulates the fluctuation of sex hormone levels during the menstrual cycle and thus may reduce fluctuation in KJL PURPOSE: Given that increased KJL is a known risk factor for sustaining knee injuries, the purpose of this study was to examine the effect of oral contraceptive use on KJL during the follicular, ovulation, and luteal phases of the menstrual cycle. METHODS: Sixty college-age women were screened for participation and fourteen (20.07±1.21 years, 163.05± 9.70, and 66.81± 12.32 kg) met the inclusion criteria, provided informed consent, and participated in the study. Based on screening questionnaires, participants were sorted into groups, oral contraceptive users (OC) and non-users (NOC). Each participant’s KJL was measured on six occasions, five days apart. KJL was measured using a KT-1000 Knee Arthrometer at 133 N. Measurements on days 1-7, 11-14, and 19-22 were used for data analysis to correspond with the three phases of the menstrual cycle. A 2x3 (group x phase) mixed model ANOVA was used to compare KJL between groups and across the three phases of the menstrual cycle. RESULTS: KJL are reported in Table 1. Group and phase did not interact to affect KJL (F(2,24)=1.92, p=0.17). KJL did not differ between OC and NOC users across the menstrual cycle (F(1,12)=0.07, p=0.80), and was not different between any phase of the menstrual cycle (F(2,24)=0.14, p=0.87). However, given that the spike in estradiol associated with the ovulation phase has been suggested to affect ligament laxity, a comparison between groups during this phase was conducted. Though KJL was larger for NOC than OC, the results of a one-tailed independent t-test suggest that this difference was not statistically significantly (t(12)= 1.72, p = 0.06). However, this difference was characterized by a large effect size (Cohen d= 0.92) suggesting that NOC users experience more KJL during the ovulation phase than OC users. CONCLUSION: The results of the study indicate that OC may play a role in KJL. However, with limited statistical power of these analyses, additional data are needed to fully assess this effect

    Diurnal Urinary Excretion of DHP in Steers Fed \u3cem\u3eLeucaena leucocephala\u3c/em\u3e

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    Leucaena (Leucaena leucocephala) contains the toxin mimosine which is quickly degraded by rumen microorganisms to isomers of dihydroxypyridine (DHP). DHP is detrimental to animal production, causing reduced thyroid hormones, reduced weight gain, goiter and severe deficiencies in essential minerals (Tsai and Ling 1971; Hammond 1995). There are several methods of testing for exposure to DHP toxicity but the simplest is the colorimetric urine spot test (Graham et al. 2013). Several researchers have noted high variability in the excretion of DHP among animals on similar leucaena diets (Dalzell et al. 2012; Phaikaew et al. 2012) and even in the same animal over sequential samplings (O\u27Reagain and Shelton 2013). They noted that it was possible to obtain samples with very low DHP in unprotected animals on high leucaena diets, leading to the false conclusion that the animal was successfully degrading DHP in the rumen. This study examined the extent and possible causes of variation of DHP concentration in spot urine samples taken over a 6-week period, including an intensive sampling over a 24 hour period

    USE OF PERIPHERAL VASOPRESSORS IN EARLY SEPSIS-INDUCED HYPOTENSION ACROSS MICHIGAN HOSPITALS

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    INTRODUCTION: Recent data suggest it may be safe to administer vasopressors via peripheral IV (PIV), challenging convention that vasopressors must be delivered centrally. Surviving Sepsis Campaign 2021 guidelines suggest using peripheral vasopressors as a bridge to central access. However, little is known about vasopressor initiation in practice. METHODS: Cohort study of patients hospitalized with community-onset sepsis at 12 hospitals in the Hospital Medicine Safety Consortium (HMS) sepsis initiative. HMS is a Collaborative Quality Initiative sponsored by Blue Cross Blue Shield of Michigan. A random sample of adult sepsis hospitalizations between 11/2020-1/2022 were included. Data were abstracted by trained abstractors. We sought to determine how commonly vasopressors were initiated via PIV vs central access across hospitals. HMS-Sepsis is expanding to 69 hospitals. Here we present pilot data; full cohort analysis is in process. RESULTS: of 1,901 patients in the HMS-Sepsis registry at the time of pilot data analysis, 440 (23.1%) had hypotension (defined by mean arterial pressure\u3c 65mmHg, systolic blood pressure\u3c 90mmHg, and/or vasopressor initiation) within 3 hours of hospital arrival. of these, 160 (36.4%) received vasopressors within 6 hours of hospital arrival. Route of initial vasopressor was PIV in 122 (76.3%), central access in 30 (18.8%), midline catheter in 1 (0.6%), oral (ie, midodrine) in 5 (3.1%), and unknown in 2 (1.3%). Across all hospitals, 50.0% to 91.7% of vasopressor initiation was via PIV (median 83.3%). Among 122 patients with vasopressor initiation via PIV, 66 (54.1%) received a 2nd vasopressor, after a median of 2.8 hrs [IQR 1, 8] from 1st vasopressor. Route of 2nd vasopressor was PIV in 27 (40.9%) and central access in 30 (45.4%). Time from hypotension to vasopressor initiation did not differ between patients receiving initial vasopressor via PIV vs central access (median 1.9 vs 2.1 hrs, p=0.79). Likewise, IV fluids within 6 hrs (median 2.0 vs 2.1L, p=0.78), hospitalization length (median 7 vs 6 days, p=0.31), and inhospital mortality (33.6% vs 40.0%, p=0.51) were similar. CONCLUSIONS: In this 12-hospital cohort, vasopressors were most frequently initiated peripherally. Outcomes were similar between patients in whom vasopressors were initiated via peripheral vs central access

    The Growth Response of Tropical and Sub-Tropical Forage Species to Increasing Salinity

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    There is currently a growing coal seam gas (CSG) industry in Queensland, Australia. The industry requires beneficial-use strategies to consume the significant volumes of water released during CSG extraction. Irrigation of tropical and sub-tropical forage species for beef production is one option, however coal seam (CS) water is of varying quality due to moderate to high salinity and alkalinity. The application of chemically amended CS water over time could potentially increase soil salinity, which is known to reduce plant biomass production. While there were studies of salinity tolerance of many tropical and sub-tropical forage species 30 years ago, there is a need to examine the tolerance of more recently released species and cultivars which are suitable for planting in the Queensland CSG area

    The Efficacy of \u3cem\u3ein vitro Synergistes jonesii\u3c/em\u3e Inoculum in Preventing DHP Toxicity in Steers Fed Leucaena-Grass Diets

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    Leucaena leucocephala (leucaena) is a valuable forage tree legume for tropical animal production that contains the toxin mimosine. The breakdown products of mimosine in ruminants (3,4-DHP and 2,3-DHP) can adversely affect their health and limit weight gains (Jones and Hegarty 1984). The rumen bacterium Synergistes jonesii, introduced into Australia in 1983 was shown to completely and rapidly degrade these toxins to safe levels (Jones and Megarrity 1986). Since 1996, an in vitro produced inoculum has been made commercially available to Australian graziers (Klieve et al. 2002). Accordingly, the issue of leucaena toxicity in Australia was thought to be resolved. However, extensive testing in 2004 found that up to 50% of Queensland cattle herds consuming leucaena were excreting high levels of urinary DHP suggesting sub-clinical toxicity remained an issue for graziers (Dalzell et al. 2012). Some of these herds had previously been inoculated with in vitro S. jonesii suggesting the inoculum may not be able to either persist within a herd, or remain effective in degrading DHP. The aim of this study was to assess the capability of the in vitro S. jonesii inoculum to efficiently break down DHP in a controlled feeding trial environment
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