123 research outputs found

    Influence of Corn Hybrid Traits and Processing Method on Nutrient Digestibility

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    Two experiments were conducted to determine the effects of corn hybrid and processing method on the site and extent of nutrient digestibility and ruminal fermentation. Treatments consisted of 2 processing methods, dry-rolled corn (DRC) and high-moisture corn (HMC), and 3 hybrids, H-8562 (1), 33P67 (2), and H-9230 (3), in a 2 × 3 factorial arrangement. In Exp. 1, six ruminally cannulated crossbred steers (436 ± 8 kg) were used in a 6 × 6 Latin square design. Total tract DM, OM, and starch digestibility (STD) were greater (P \u3c 0.10) for HMC compared with DRC. A hybrid × processing method interaction (P \u3c 0.10) was observed for propionate concentration and the acetate-to-propionate ratio. In Exp. 2, two ruminally and duodenally fistulated steers were used to determine the site and extent of nutrient digestion using the mobile bag technique at 2 ruminal incubation times. Ruminal STD was not different (P = 0.14) among hybrids but was greater (P \u3c 0.01) for HMC compared with DRC. Postruminal and total tract STD were greater (P \u3c 0.01) for hybrids 1 and 3 than for hybrid 2, and were greater (P \u3c 0.01) for HMC than DRC. In both experiments the geometric mean diameter and geometric SD were influenced (P \u3c 0.05) by both hybrid and processing method. More intense processing methods or selection of hybrids with softer kernels will result in greater digestibility and ruminal propionate concentrations. Digestibility of corn samples can be characterized using the mobile bag technique but particle size can influence results

    Influence of Corn Hybrid and Processing Method on Ruminal and Intestinal Digestion

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    Using the mobile bag technique, five commercially available corn hybrids harvested as either dry-rolled or high-moisture corn were evaluated for site and extent of DM and starch digestion. Total-tract DM digestibility was improved 7 to 16 percentage units, and total-tract starch digestibility was improved 9 to 18 percentage units among hybrids when processed as high-moisture corn compared to dry-rolled corn. The results of this trial suggest that hybrid and processing method interact and can influence DM and starch digestibility

    Using Ecological Modelling Tools to Inform Policy Makers of Potential Changes in Crop Distribution: An Example with Cacao Crops in Latin America

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    International audienceSpecies distribution models (SDM) is a powerful simulation tool that has become widely used in the ecological and agronomical sciences. The use of easily available presence data, global downscaled climate layers and software that can run on desktop computer has contributed to their popularity. The most used application is based on maximum entropy models that fit presence data to a series of environmental descriptors. SDM can be used to predict crop distribution under future conditions but the level of uncertainty of those models can be very high. The best use of these models is to be used as generators of hypothesis to be combined with other type of analysis

    Chondrocyte Deformations as a Function of Tibiofemoral Joint Loading Predicted by a Generalized High-Throughput Pipeline of Multi-Scale Simulations

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    Cells of the musculoskeletal system are known to respond to mechanical loading and chondrocytes within the cartilage are not an exception. However, understanding how joint level loads relate to cell level deformations, e.g. in the cartilage, is not a straightforward task. In this study, a multi-scale analysis pipeline was implemented to post-process the results of a macro-scale finite element (FE) tibiofemoral joint model to provide joint mechanics based displacement boundary conditions to micro-scale cellular FE models of the cartilage, for the purpose of characterizing chondrocyte deformations in relation to tibiofemoral joint loading. It was possible to identify the load distribution within the knee among its tissue structures and ultimately within the cartilage among its extracellular matrix, pericellular environment and resident chondrocytes. Various cellular deformation metrics (aspect ratio change, volumetric strain, cellular effective strain and maximum shear strain) were calculated. To illustrate further utility of this multi-scale modeling pipeline, two micro-scale cartilage constructs were considered: an idealized single cell at the centroid of a 100×100×100 μm block commonly used in past research studies, and an anatomically based (11 cell model of the same volume) representation of the middle zone of tibiofemoral cartilage. In both cases, chondrocytes experienced amplified deformations compared to those at the macro-scale, predicted by simulating one body weight compressive loading on the tibiofemoral joint. In the 11 cell case, all cells experienced less deformation than the single cell case, and also exhibited a larger variance in deformation compared to other cells residing in the same block. The coupling method proved to be highly scalable due to micro-scale model independence that allowed for exploitation of distributed memory computing architecture. The method’s generalized nature also allows for substitution of any macro-scale and/or micro-scale model providing application for other multi-scale continuum mechanics problems

    Communications Biophysics

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    Contains reports on eight research projects split into four sections.National Institutes of Health (Grant 5 P01 NS13126)National Institutes of Health (Grant 5 K04 NS00113)National Institutes of Health (Training Grant 5 T32 NS07047)National Science Foundation (Grant BNS80-06369)National Institutes of Health (Grant 5 ROl NS11153)National Institutes of Health (Fellowship 1 F32 NS06544)National Science Foundation (Grant BNS77-16861)National Institutes of Health (Grant 5 R01 NS10916)National Institutes of Health (Grant 5 RO1 NS12846)National Science Foundation (Grant BNS77-21751)National Institutes of Health (Grant 1 R01 NS14092)National Institutes of Health (Grant 2 R01 NS11680)National Institutes of Health (Grant 5 ROl1 NS11080)National Institutes of Health (Training Grant 5 T32 GM07301

    Biomechanical considerations in the pathogenesis of osteoarthritis of the knee

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    Osteoarthritis is the most common joint disease and a major cause of disability. The knee is the large joint most affected. While chronological age is the single most important risk factor of osteoarthritis, the pathogenesis of knee osteoarthritis in the young patient is predominantly related to an unfavorable biomechanical environment at the joint. This results in mechanical demand that exceeds the ability of a joint to repair and maintain itself, predisposing the articular cartilage to premature degeneration. This review examines the available basic science, preclinical and clinical evidence regarding several such unfavorable biomechanical conditions about the knee: malalignment, loss of meniscal tissue, cartilage defects and joint instability or laxity

    Origin and insertion of the medial patellofemoral ligament: a systematic review of anatomy.

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    PURPOSE: The medial patellofemoral ligament (MPFL) is the major medial soft-tissue stabiliser of the patella, originating from the medial femoral condyle and inserting onto the medial patella. The exact position reported in the literature varies. Understanding the true anatomical origin and insertion of the MPFL is critical to successful reconstruction. The purpose of this systematic review was to determine these locations. METHODS: A systematic search of published (AMED, CINAHL, MEDLINE, EMBASE, PubMed and Cochrane Library) and unpublished literature databases was conducted from their inception to the 3 February 2016. All papers investigating the anatomy of the MPFL were eligible. Methodological quality was assessed using a modified CASP tool. A narrative analysis approach was adopted to synthesise the findings. RESULTS: After screening and review of 2045 papers, a total of 67 studies investigating the relevant anatomy were included. From this, the origin appears to be from an area rather than (as previously reported) a single point on the medial femoral condyle. The weighted average length was 56 mm with an 'hourglass' shape, fanning out at both ligament ends. CONCLUSION: The MPFL is an hourglass-shaped structure running from a triangular space between the adductor tubercle, medial femoral epicondyle and gastrocnemius tubercle and inserts onto the superomedial aspect of the patella. Awareness of anatomy is critical for assessment, anatomical repair and successful surgical patellar stabilisation. LEVEL OF EVIDENCE: Systematic review of anatomical dissections and imaging studies, Level IV

    Role of biomechanics in the understanding of normal, injured, and healing ligaments and tendons

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    Ligaments and tendons are soft connective tissues which serve essential roles for biomechanical function of the musculoskeletal system by stabilizing and guiding the motion of diarthrodial joints. Nevertheless, these tissues are frequently injured due to repetition and overuse as well as quick cutting motions that involve acceleration and deceleration. These injuries often upset this balance between mobility and stability of the joint which causes damage to other soft tissues manifested as pain and other morbidity, such as osteoarthritis

    Tissue adhesives for meniscus tear repair: an overview of current advances and prospects for future clinical solutions

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    Influence of Corn Hybrid and Processing Method on Finishing Performance and Carcass Characteristics

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    Five commercially available corn hybrids were evaluated for finishing cattle performance and carcass characteristics when fed as high-moisture (HMC) or dry-rolled corn (DRC). No significant interactions were observed between hybrid and processing method. Corn hybrid had no significant impact on ADG or DMI, but did have a minor influence on F:G. However, these data suggested that processing as HMC-method had a greater effect on cattle performance than hybrid
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