1,372 research outputs found

    Pregnancy Diagnosis in the Ewe

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    A total 378 ewe lambs were evaluated for signs of pregnancy by five operators using five methods of detection. The methods used were breeding mark, rectal-abdominal palpation, an intrarectal Doppler instrument and two ultrasonic devices, the Scanoprobe and Scanopreg (Model 738) for sheep. Accuracies of pregnancy diagnosis by grease mark were 65.7% in 1976 and 75.5% in 1977 (P\u3c.05) based on lambing results. Accuracy of daignosis for ewe lambs called pregnany or nonpregnany using the recetal-abdominal palpation technique was 62.7%. The overall accuracy on the same ewes using the intrarectal Doppler device was 72.7%. The ewes were examined when they were from 60 to 96 days of gestation using the two rectal probes. Seven ewes died from peritonitis and six aborted following pregnancy detection using the rectal instruments. Accuracy using the Scanoprobe device was 89.1% for ewe lambs which ranged from 69 to 103 days pregnant. The accuracy achieved when the same ewes were evaluated at 78 to 112 days of gestation using the Scanopreg device 94.8%. No injuries occurred following pregnancy detection using the two ultrasonic devices. Ewes called open with the Scanopreg were retested the following day with a 98.8% accuracy rate

    Quantitative evaluation of polymer gel dosimeters by broadband ultrasound attenuation

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    Ultrasound has been examined previously as an alternative readout method for irradiated polymer gel dosimeters, with authors reporting varying dose response to ultrasound transmission measurements. In this current work we extend previous work to measure the broadband ultrasound attenuation (BUA) response of irradiated PAGAT gel dosimeters, using a novel ultrasound computed tomography system

    The clinical application of PET/CT: a contemporary review

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    The combination of positron emission tomography (PET) scanners and x-ray computed tomography (CT) scanners into a single PET/CT scanner has resulted in vast improvements in the diagnosis of disease, particularly in the field of oncology. A decade on from the publication of the details of the first PET/CT scanner, we review the technology and applications of the modality. We examine the design aspects of combining two different imaging types into a single scanner, and the artefacts produced such as attenuation correction, motion and CT truncation artefacts. The article also provides a discussion and literature review of the applications of PET/CT to date, covering detection of tumours, radiotherapy treatment planning, patient management, and applications external to the field of oncology

    Atroposelective NiII‐Catalyzed Cross‐Coupling Reactions Enable a Deeper Understanding of Negishi Couplings: Isolation and Application of Solid Aryl Higher‐Order Zincates

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    The Negishi cross-coupling reactions involves the application of organozinc reagents and is a highly versatile reaction in synthetic organic chemistry. The transmetallation step plays a pivotal role in the mechanism of these types of cross-coupling reactions. In this study, mechanistic investigations are presented indicating that higher-order zincates are the transmetallating active species in Pd- and Ni-catalyzed Negishi cross-coupling reactions. These findings are supported by halide salt addition experiments and by obtaining a single X-ray crystal structure of the solid monoaryl higher-order zincate [1-NaphthylZnX3]2−Mg(THF)22+. The procedure developed in this work was further applied to the synthesis of various monoaryl higher-order zincates, after which their synthetic usefulness in terms of high reactivity towards transmetallation in Negishi cross-couplings, as well as stability, was exemplified in several reactions

    Incidence and Mortality of Mucosal Disease in Iowa

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    Mucosal disease was first recognized in Iowa as an apparently new disease entity in cattle in January of 1951. The following inquiry is often made: Is the incidence of mucosal disease in cattle increasing in Iowa? It is difficult to determine accurately the incidence of any disease in farm animals

    A Survey of Operations Research and Analytics Literature Related to Anti-Human Trafficking

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    Human trafficking is a compound social, economic, and human rights issue occurring in all regions of the world. Understanding and addressing such a complex crime requires effort from multiple domains and perspectives. As of this writing, no systematic review exists of the Operations Research and Analytics literature applied to the domain of human trafficking. The purpose of this work is to fill this gap through a systematic literature review. Studies matching our search criteria were found ranging from 2010 to March 2021. These studies were gathered and analyzed to help answer the following three research questions: (i) What aspects of human trafficking are being studied by Operations Research and Analytics researchers? (ii) What Operations Research and Analytics methods are being applied in the anti-human trafficking domain? and (iii) What are the existing research gaps associated with (i) and (ii)? By answering these questions, we illuminate the extent to which these topics have been addressed in the literature, as well as inform future research opportunities in applying analytical methods to advance the fight against human trafficking.Comment: 28 pages, 6 Figures, 2 Table

    Reconstructing 3D x-ray CT images of polymer gel dosimeters using the zero-scan method

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    In this study x-ray CT has been used to produce a 3D image of an irradiated PAGAT gel sample, with noise-reduction achieved using the ‘zero-scan’ method. The gel was repeatedly CT scanned and a linear fit to the varying Hounsfield unit of each pixel in the 3D volume was evaluated across the repeated scans, allowing a zero-scan extrapolation of the image to be obtained. To minimise heating of the CT scanner’s x-ray tube, this study used a large slice thickness (1 cm), to provide image slices across the irradiated region of the gel, and a relatively small number of CT scans (63), to extrapolate the zero-scan image. The resulting set of transverse images shows reduced noise compared to images from the initial CT scan of the gel, without being degraded by the additional radiation dose delivered to the gel during the repeated scanning. The full, 3D image of the gel has a low spatial resolution in the longitudinal direction, due to the selected scan parameters. Nonetheless, important features of the dose distribution are apparent in the 3D x-ray CT scan of the gel. The results of this study demonstrate that the zero-scan extrapolation method can be applied to the reconstruction of multiple x-ray CT slices, to provide useful 2D and 3D images of irradiated dosimetry gels

    Scaling Behavior of Human Locomotor Activity Amplitude: Association with Bipolar Disorder

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    Scale invariance is a feature of complex biological systems, and abnormality of multi-scale behaviour may serve as an indicator of pathology. The hypothalamic suprachiasmatic nucleus (SCN) is a major node in central neural networks responsible for regulating multi-scale behaviour in measures of human locomotor activity. SCN also is implicated in the pathophysiology of bipolar disorder (BD) or manic-depressive illness, a severe, episodic disorder of mood, cognition and behaviour. Here, we investigated scaling behaviour in actigraphically recorded human motility data for potential indicators of BD, particularly its manic phase. A proposed index of scaling behaviour (Vulnerability Index [VI]) derived from such data distinguished between: [i] healthy subjects at high versus low risk of mood disorders; [ii] currently clinically stable BD patients versus matched controls; and [iii] among clinical states in BD patients
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