337 research outputs found
Sources of Streptococcus dysgalactiae in English and Welsh sheep flocks affected by infectious arthritis (joint ill)
Editorial Perspective: When is a ‘small effect’ actually large and impactful?
Reporting of effect sizes is standard practice in psychology and psychiatry research. However, interpretation of these effect sizes can be meaningless or misleading – in particular, the evaluation of specific effect sizes as ‘small’, ‘medium’ and ‘large’ can be inaccurate depending on the research context. A real-world example of this is research into the mental health of children and young people during the COVID-19 pandemic. Evidence suggests that clinicians and services are struggling with increased demand, yet population studies looking at the difference in mental health before and during the pandemic report effect sizes that are deemed ‘small’. In this short review, we utilise simulations to demonstrate that a relatively small shift in mean scores on mental health measures can indicate a large shift in the number of cases of anxiety and depression when scaled up to an entire population. This shows that ‘small’ effect sizes can in some contexts be large and impactful
Evaluation of a VNA-based Material Characterization Kit at Frequencies from 0.75 THz to 1.1 THz
This paper describes an initial assessment of a commercially available THz material characterization kit (MCK). The assessment is based on the measurement of several material samples. The MCK comprises two conical waveguide horn transitions and two sections of low-loss corrugated waveguide. A gap between the two corrugated waveguides allows the material samples to be inserted into the system during measurement. The MCK is attached to a THz Vector Network Analyzer (VNA), which measures S-parameters, in the frequency domain, of a material under test (MUT). A computer-based algorithm employing an iterative calculation derives values for material parameters (e.g. permittivity) from the measured S-parameters of the MUT. A MCK has been evaluated over the frequency range 0.75 THz to 1.1 THz, to assess the plausibility of results that can be obtained using such a technique. Two VNAs utilizing frequency extender heads were used for the investigation, with measurements being made with reference to a range of different calibration techniques and different calibration standards. Whilst some of the results obtained look reasonable, a significant proportion of the results were either difficult to interpret or showed inexplicable (i.e. non-physical) behavior. This indicates that much work is still needed before this technique can be used routinely for the measurement of material parameters at these very high frequencies
Microwave characterization of low-loss FDM 3-D printed ABS with dielectric-filled metal-pipe rectangular waveguide spectroscopy
Over time the accuracy and speed by which a material can be characterized should improve. Today, the Nicolson-Ross-Weir (NRW) methodology represents a well-established method for extracting complex dielectric properties at microwave frequencies, with the use of a modern vector network analyzer. However, as will be seen, this approach suffers from three fundamental limitations to accuracy. Challenging NRW methods requires a methodical and robust investigation. To this end, using a dielectric-filled metal-pipe rectangular waveguide, five independent approaches are employed to accurately characterize the sample at the Fabry-Pérot resonance frequency (non-frequency dispersive modeling). In addition, manual Graphical and automated Renormalization spectroscopic approaches are introduced for the first time in waveguide. The results from these various modeling strategies are then compared and contrasted to NRW approaches. As a timely exemplar, 3-D printed acrylonitrile-butadiene-styrene (ABS) samples are characterized and the results compared with existing data available in the open literature. It is found that the various Fabry-Pérot resonance model results all agree with one another and validate the two new spectroscopic approaches; in so doing, exposing three limitations of the NRW methods. It is also shown that extracted dielectric properties for ABS differ from previously reported results and reasons for this are discussed. From measurement noise resilience analysis, a methodology is presented for determining the upper-bound signal-to-noise ratio for the vector network analyzer (not normally associated with such instrumentation). Finally, fused deposition modeling (FDM) 3-D printing results in a non-homogeneous sample that excites open-box mode resonances. This phenomenon is investigated for the first time, analytically and with various modeling strategies
Financial Benefits Review: Transformation Challenge Award programme, Essex County Council
This is an Interim Financial Benefits Review (FBR) for projects that have been funded by the Transformation Challenge Award (TCA) and are being delivered by Essex Partners. The review only covers those projects funded by the TCA that have financial benefits associated with them in the initial proposal of work. The projects in scope included the Domestic Abuse Housing Database, the Domestic Abuse in Health – IDVA project, the Parish Safety Volunteers, the Social Prescription and the Essex Data: Program.
This report aimed at producing a clear model of how cashable benefits of £27.5 million over 10 years will be delivered, or a revision of expectations if necessary and to recommend actions to employ with respect to financial benefits delivery in future service provision based on lessons learnt
Options Paper, Transformation Challenge Award (TCA) Programme Evaluation
This paper sets out possible next steps in response to the Interim Financial Benefits Review (FBR) of the Transformation Challenge Award (TCA) funded projects submitted on the 13/09/2017 and presents options for action to address the recommendations of the report
Carotid endarterectomy in the U.K. and Ireland: Audit of 30-day outcome
Objectives and Design:A prospective study of 709 patients undergoing carotid surgery in the U.K. and Ireland was performed to evaluate the performance of vascular surgeons.Materials and Methods:Fifty-nine surgeons (range 2–39 cases each) were sampled and all patients undergoing surgery over a 6-month period (1 March 1994–31 August 1994) were included in the study. Indications for surgery were TIA (35.9%), AF (23.3%), CVA (21.4%) and “others” (19.6%).Results:Mean ipsilateral stenosis was 82% (30%–99%). Thirty-one percent of patients had preoperative neurological consults. Shunts were used in 67.6%, tacking sutures in 40.1%, drains in 71.9% and patches in 54.4% of cases. At 30 days there were nine (1.3%) deaths (four cardiac, three neurological). There were 15 ipsilateral postoperative CVAs (2.1%); 19% of patients had one or more complication, usually minor. Statistical analysis showed no independent risk factor for CVA other than seniority of the surgeon.Conclusions:A combined stroke/death rate of 3% for the series was obtained at 30 days for all cases. This large, validated study suggests that members of the Vascular Society of G.B. and Ireland currently have a very low morbidity/mortality rate for performing carotid surgery. Continued audit is required to ensure that this quality of service does not deteriorate
C9orf72 repeat expansions cause neurodegeneration in Drosophila through arginine-rich proteins
An expanded GGGGCC repeat in C9orf72 is the most common genetic cause of frontotemporal dementia and amyotrophic lateral sclerosis. A fundamental question is whether toxicity is driven by the repeat RNA itself and/or by dipeptide repeat proteins generated by repeat-associated, non-ATG translation. To address this question we developed in vitro and in vivo models to dissect repeat RNA and dipeptide repeat protein toxicity. Expression of pure repeats in Drosophila caused adult-onset neurodegeneration attributable to poly-(glycine-arginine) proteins. Thus, expanded repeats promoted neurodegeneration through neurotoxic proteins. Expression of individual dipeptide repeat proteins with a non-GGGGCC RNA sequence showed both poly-(glycine-arginine) and poly-(proline-arginine) proteins caused neurodegeneration. These findings are consistent with a dual toxicity mechanism, whereby both arginine-rich proteins and repeat RNA contribute to C9orf72-mediated neurodegeneration
Electrical and network neuronal properties are preferentially disrupted in dorsal, but not ventral, medial entorhinal cortex in a mouse model of Tauopathy
The entorhinal cortex (EC) is one of the first areas to be disrupted in neurodegenerative diseases such as Alzheimer's disease and frontotemporal dementia. The responsiveness of individual neurons to electrical and environmental stimuli varies along the dorsal-ventral axis of the medial EC (mEC) in a manner that suggests this topographical organization plays a key role in neural encoding of geometric space. We examined the cellular properties of layer II mEC stellate neurons (mEC-SCs) in rTg4510 mice, a rodent model of neurodegeneration. Dorsoventral gradients in certain intrinsic membrane properties, such as membrane capacitance and afterhyperpolarizations, were flattened in rTg4510 mEC-SCs, while other cellular gradients [e.g., input resistance (Ri), action potential properties] remained intact. Specifically, the intrinsic properties of rTg4510 mEC-SCs in dorsal aspects of the mEC were preferentially affected, such that action potential firing patterns in dorsal mEC-SCs were altered, while those in ventral mEC-SCs were unaffected. We also found that neuronal oscillations in the gamma frequency band (30-80 Hz) were preferentially disrupted in the dorsal mEC of rTg4510 slices, while those in ventral regions were comparatively preserved. These alterations corresponded to a flattened dorsoventral gradient in theta-gamma cross-frequency coupling of local field potentials recorded from the mEC of freely moving rTg4510 mice. These differences were not paralleled by changes to the dorsoventral gradient in parvalbumin staining or neurodegeneration. We propose that the selective disruption to dorsal mECs, and the resultant flattening of certain dorsoventral gradients, may contribute to disturbances in spatial information processing observed in this model of dementia. SIGNIFICANCE STATEMENT: The medial entorhinal cortex (mEC) plays a key role in spatial memory and is one of the first areas to express the pathological features of dementia. Neurons of the mEC are anatomically arranged to express functional dorsoventral gradients in a variety of neuronal properties, including grid cell firing field spacing, which is thought to encode geometric scale. We have investigated the effects of tau pathology on functional dorsoventral gradients in the mEC. Using electrophysiological approaches, we have shown that, in a transgenic mouse model of dementia, the functional properties of the dorsal mEC are preferentially disrupted, resulting in a flattening of some dorsoventral gradients. Our data suggest that neural signals arising in the mEC will have a reduced spatial content in dementia
Achieving the Way for Automated Segmentation of Nuclei in Cancer Tissue Images through Morphology-Based Approach: a Quantitative Evaluation
In this paper we address the problem of nuclear segmentation in cancer tissue images, that is critical for specific protein activity quantification and for cancer diagnosis and therapy. We present a fully automated morphology-based technique able to perform accurate nuclear segmentations in images with heterogeneous staining and multiple tissue layers and we compare it with an alternate semi-automated method based on a well established segmentation approach, namely active contours. We discuss active contours’ limitations in the segmentation of immunohistochemical images and we demonstrate and motivate through extensive experiments the better accuracy of our fully automated approach compared to various active contours implementations
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