275 research outputs found

    Light emitting diode (LED) color and broiler growth: effect of supplementing blue/green LED to white LED light on broiler growth, stress, and welfare

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    Light emitting diode (LED) lighting provides an affordable lighting option for use in commercial poultry production. However, more information is needed to understand the effects of LED color on broiler welfare and growth. Five consecutive flocks (1 in summer, 1 in fall, 2 in winter, and 1 in spring) of straight run Ross 708 × Ross 708 broilers were reared in commercial type barns for 45 D. For white only (WO) treatment, birds were reared under white LED only (Agrishift MLB). For white supplemented (WS) treatment, birds were reared under white LED (Agrishift MLB) in the center aisle, with supplemental blue/green LED lighting (Agrishift MLBg) above the feed and water lines on either side of the barn. Each barn housed 26,200 chicks, and there were 2 barns in each treatment (n = 52,400/treatment). Treatments were rotated among barns between each flock. On day 45, blood samples were collected from 20 birds/barn (n = 40/treatment) to assess the plasma corticosterone (CORT) level and heterophil/lymphocyte ratio. On day 45, 100 birds/barn (n = 200/treatment) were weighed individually and assigned scores for hock burn and foot pad dermatitis. All measures were affected by trial (P \u3c 0.001). Plasma CORT and body weight were affected by the treatment × trial interaction (P ≤ 0.001). Overall, birds in the WS treatment had higher day 45 live body weight (P \u3c 0.001) and lower hock burn scores (P = 0.032) than birds in the WO treatment. Birds in the WS treatment had higher day 45 body weight overall (P \u3c 0.001) and in trials 1, 3, and 5, although the overall body weight was lower in trials 1, 3, and 5 than in trials 2 and 4. Supplemental blue/green LED improved hock burn scores and increased overall day 45 body weight. However, trial differences suggest that more data are needed to determine whether supplementing blue/green LED to white LED improves body weight gain in mixed sex broiler chickens

    Comparison of an intermittent, short-dawn/dusk photoperiod with an increasing, long-dawn/dusk photoperiod on broiler growth, stress, and welfare

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    Photoperiod has been shown to significantly affect broiler performance. However, the effects of the traditional 1-min dimming period on broiler growth and welfare are unclear. In this study, 4 consecutive trials were conducted to compare the effects of an intermittent, short-dawn/dusk photoperiod (ISD) to an increasing, long-dawn/dusk photoperiod (ILD) on broiler growth, stress, and welfare. Straight run day-of-hatch Ross 708 × Ross 708 broilers were placed in 1 of 4 commercial broiler barns (2 b of 26,200 birds each per treatment) and grown to 45 D of age. The photoperiod in the ISD treatment consisted of 24L:0D day 0 to 6, 16L:8D day 7 to 13, 12L:4D:2L:6D day 14 to 20, 12L:4D:3L:5D day 21 to 27, 12L:4D:4L:4D day 28 to 41, and 13L:3D:5L:3D day 42 to 45, with a 1-min transition between light and dark periods. The photoperiod in the ILD treatment consisted of 23L:1D day 0 to 7, 16L:8D day 8 to 21, 18L:6D day 22 to 32, and 20L:4D day 33 to 45, with a 1-min light/dark transition period day 0 to 7 and a 30-min transition period day 8 to 45. Treatments were rotated among the barns between trials. On day 45, blood samples were collected from 20 birds/barn (n = 40/treatment) to assess plasma corticosterone (CORT) and heterophil/lymphocyte (H/L) ratio. One hundred birds per barn (n = 200/treatment) were weighed individually and assigned scores for hock burn, foot pad dermatitis, and feather condition on day 45. Trial differences were observed for all measures (P ≤ 0.001). Birds in the ISD treatment were heavier on day 45 (P \u3c 0.001) and had lower hock burn (P = 0.044) and foot pad dermatitis (P \u3c 0.001) scores. Birds in the ILD treatment had lower plasma CORT (P \u3c 0.001) and H/L ratio (P \u3c 0.001). No treatment differences were observed for feather condition (P \u3e 0.05). Overall, birds reared under the intermittent, short-dawn/dusk photoperiod had higher day 45 live body weights and lower hock burn and foot pad dermatitis scores, whereas those reared under the increasing, long-dawn/dusk photoperiod had reduced measures of short-term and long-term stress

    Conformal Robotic Stereolithography

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    Additive manufacturing by layerwise photopolymerization, commonly called stereolithography (SLA), is attractive due to its high resolution and diversity of materials chemistry. However, traditional SLA methods are restricted to planar substrates and planar layers that are perpendicular to a single-axis build direction. Here, we present a robotic system that is capable of maskless layerwise photopolymerization on curved surfaces, enabling production of large-area conformal patterns and the construction of conformal freeform objects. The system comprises an industrial six-axis robot and a custom-built maskless projector end effector. Use of the system involves creating a mesh representation of the freeform substrate, generation of a triangulated toolpath with curved layers that represents the target object to be printed, precision mounting of the substrate in the robot workspace, and robotic photopatterning of the target object by coordinated motion of the robot and substrate. We demonstrate printing of conformal photopatterns on spheres of various sizes, and construction of miniature three-dimensional objects on spheres without requiring support features. Improvement of the motion accuracy and development of freeform toolpaths would enable construction of polymer objects that surpass the size and support structure constraints imparted by traditional SLA systems.American Society for Engineering Education. National Defense Science and Engineering Graduate FellowshipNational Institute of Mental Health (U.S.) (University of Michigan Microfluidics in Biomedical Sciences Training Program. 5T32-EB005582)Singapore-MIT Alliance for Research and Technology (SMART

    Exposure to DDT from indoor residual spraying and biomarkers of inflammation among reproductive-aged women from South Africa

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    BACKGROUND : Evidence from animal studies suggests that DDT and DDE can adversely affect immuno-competence while human data are less conclusive. We aimed to assess the association of plasma concentrations of DDT and DDE with biomarkers of inflammation among reproductive-aged women residing in homes sprayed with DDT through Indoor Residual Spraying (IRS). METHODS : This study included 416 women from the Study of Women and Babies, South Africa (2010–2011). DDT, DDE, and biomarkers of inflammation (immunoglobulins A, G and M, interleukins 1β, 6, and 8, tumor necrosis factor-α, C-reactive protein, serum amyloid-A, intercellular adhesion molecule-1, vascular cell adhesion molecule-1) were quantified in plasma. Linear regression was used to assess associations of DDT and DDE with each natural log-transformed biomarker. Models were adjusted for age, body mass index, parity, income, and season; beta estimates were expressed as percent differences. RESULTS : Compared to women with the lowest plasma concentrations of DDT and DDE, those with the highest concentrations of both compounds had higher levels IL-1β, IL6, and TNF- α. While associations were statistically significant for both DDT and DDE, the magnitude of the associations was slightly stronger for DDT. Compared to women in the lowest quintile of DDT, women in the highest quintile were estimated to have 53.0% (95%CI: 21.7%, 84.4%), 28.1% (95%CI: 6.4%, 49.8%), and 26.6% (95%CI: 12.0%, 41.1%) higher levels of IL-1β, IL6, and TNF- α, respectively. CONCLUSIONS : Our results suggest that increased plasma concentrations of DDT and DDE resulting from exposure to IRS may increase concentrations of pro-inflammatory biomarkers among reproductive-aged women in South Africa.The National Institute of Environmental Health Sciences, National Institutes of Health; and the Intramural Research Program of the NIH, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA.http://www.elsevier.com/locate/envres2021-12-01hj2020School of Health Systems and Public Health (SHSPH

    Predictors of plasma DDT and DDE concentrations among women exposed to indoor residual spraying for malaria control in the South African Study of Women and Babies (SOWB)

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    BACKGROUND : Few studies have examined predictors of DDT (dichlorodiphenyltrichloroethane) and DDE (dichlorodiphenyldichloroethylene) levels among residents in homes sprayed with DDT for malaria control with the aim of identifying exposure-reduction strategies. METHODS : The present analysis included 381 women enrolled in the Study of Women and Babies (SOWB) during 2010–2011, from eight South African villages in the Limpopo Province, South Africa. Indoor residual spraying (IRS) occurred in half of the villages. Questionnaires regarding various demographic and medical factors were administered and blood samples were obtained. We classified the women into three exposure groups by type of residence: unsprayed village (n = 175), IRS village in household with a low likelihood of DDT use (non-DDT IRS household, n = 106), IRS village in household with a high likelihood of DDT use (DDT IRS household, n = 100). We used multivariable models of natural log-transformed DDT plasma levels (in micrograms per liter) and DDE (in micrograms per liter) to identify predictors for each group. RESULTS : Median levels of DDT and DDE among women in unsprayed villages were 0.3 [interquartile range (IQR): 0.1–0.9] and 1.7 (IQR: 0.7–5.5), respectively. Median levels of DDT and DDE among women in DDT IRS households were 2.6 (IQR: 1.1–6.6) and 8.5 (IQR: 4.7–18.0), respectively. In unsprayed villages, women with water piped to the yard, rather than a public tap, had 73% lower DDT (95% CI: –83, –57%) and 61% lower DDE (95% CI: –74, –40%) levels. In DDT IRS households, women who reported taking more than six actions to prepare their home before IRS (e.g., covering water and food) had 40% lower DDT levels (95% CI: –63, –0.3%) than women who took fewer than four actions. CONCLUSION : The predictors of DDT and DDE plasma levels identified in the present study may inform interventions aimed at decreasing exposure. Among households where DDT is likely to be used for IRS, education regarding home preparations may provide an interventional target.http://ehp.niehs.nih.gov/hb201

    Anesthesiologists' and surgeons' perceptions about routine pre-operative testing in low risk patients: application of the Theoretical Domains Framework to identify factors that influence physicians' decisions to order pre-operative tests

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    Background Routine pre-operative tests for anesthesia management are often ordered by both anesthesiologists and surgeons for healthy patients undergoing low-risk surgery. The Theoretical Domains Framework (TDF) was developed to investigate determinants of behaviour and identify potential behaviour change interventions. In this study, the TDF is used to explore anaesthesiologists’ and surgeons’ perceptions of ordering routine tests for healthy patients undergoing low-risk surgery. Conclusion We identified key factors that anesthesiologists and surgeons believe influence whether they order pre-operative tests routinely for anesthesia management for a healthy adults undergoing low-risk surgery. These beliefs identify potential individual, team, and organisation targets for behaviour change interventions to reduce unnecessary routine test ordering. Methods Sixteen clinicians (eleven anesthesiologists and five surgeons) throughout Ontario were recruited. An interview guide based on the TDF was developed to identify beliefs about preoperative testing practices. Content analysis of physicians’ statements into the relevant theoretical domains was performed. Specific beliefs were identified by grouping similar utterances of the interview participants. Relevant domains were identified by noting the frequencies of the beliefs reported, presence of conflicting beliefs, and perceived influence on the performance of the behaviour under investigation. Results Seven of the twelve domains were identified as likely relevant to changing clinicians’ behaviour about pre-operative test ordering for anesthesia management. Key beliefs were identified within these domains including: conflicting comments about who was responsible for the test-ordering (Social/professional role and identity); inability to cancel tests ordered by fellow physicians (Beliefs about capabilities and social influences); and the problem with tests being completed before the anesthesiologists see the patient (Beliefs about capabilities and Environmental context and resources). Often, tests were ordered by an anesthesiologist based on who may be the attending anesthesiologist on the day of surgery while surgeons ordered tests they thought anesthesiologists may need (Social influences). There were also conflicting comments about the potential consequences associated with reducing testing, from negative (delay or cancel patients’ surgeries), to indifference (little or no change in patient outcomes), to positive (save money, avoid unnecessary investigations) (Beliefs about consequences). Further, while most agreed that they are motivated to reduce ordering unnecessary tests (Motivation and goals), there was still a report of a gap between their motivation and practice (Behavioural regulation)

    Skeleton of an unusual cat-sized marsupial relative (Metatheria: Marsupialiformes) from the middle Eocene (Lutetian: 44-43 million years ago) of Turkey

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    We describe a near-complete, three-dimensionally preserved skeleton of a metatherian (relative of modern marsupials) from the middle Eocene (Lutetian: 44–43 million years ago) Lülük member of the Uzunçarşıdere Formation, central Turkey. With an estimated body mass of 3–4 kg, about the size of a domestic cat (Felis catus) or spotted quoll (Dasyurus maculatus), it is an order of magnitude larger than the largest fossil metatherians previously known from the Cenozoic of the northern hemisphere. This new taxon is characterised by large, broad third premolars that probably represent adaptations for hard object feeding (durophagy), and its craniodental morphology suggests the capacity to generate high bite forces. Qualitative and quantitative functional analyses of its postcranial skeleton indicate that it was probably scansorial and relatively agile, perhaps broadly similar in locomotor mode to the spotted quoll, but with a greater capacity for climbing and grasping. Bayesian phylogenetic analysis of a total evidence dataset comprising 259 morphological characters and 9kb of DNA sequence data from five nuclear protein-coding genes, using both undated and “tip-and-node dating” approaches, place the new taxon outside the marsupial crown-clade, but within the clade Marsupialiformes. It demonstrates that at least one metatherian lineage evolved to occupy the small-medium, meso- or hypo-carnivore niche in the northern hemisphere during the early Cenozoic, at a time when there were numerous eutherians (placentals and their fossil relatives) filling similar niches. However, the known mammal fauna from Uzunçarşıdere Formation appears highly endemic, and geological evidence suggests that this region of Turkey was an island for at least part of the early Cenozoic, and so the new taxon may have evolved in isolation from potential eutherian competitors. Nevertheless, the new taxon reveals previously unsuspected ecomorphological disparity among northern hemisphere metatherians during the first half of the Cenozoic
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