295 research outputs found

    Hypoxia Affects Performance Traits and Body Composition of Juvenile Hybrid Striped Bass (Morone chrysops x M. saxatilis)

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    Performance traits and body composition of juvenile hybrid striped bass (Morone chrysops x M. saxatilis) in response to hypoxia were evaluated in replicate tanks maintained at constant dissolved oxygen concentrations that averaged 23.0 ± 2.3%, 39.7 ± 3.0%, and 105.5 ± 9.5% dissolved oxygen saturation. Fish were fed a commercially formulated feed daily to apparent satiation. Total feed intake and fish growth and yield increased linearly in response to increased dissolved oxygen concentration. Nutrient utilization was reduced significantly only at the greatest level of hypoxia. With the exception of whole-body protein content, whole body compositional indices and nutrient retention efficiencies were linearly related to dissolved oxygen concentration. Results demonstrate that as hypoxia becomes more severe, juvenile hybrid striped bass feed intake is reduced, which affects growth and nutrient retention

    Hypoxia affects performance traits and body composition of juvenile hybrid striped bass (Morone chrysops x M. saxatilis)

    Get PDF
    Performance traits and body composition of juvenile hybrid striped bass (Morone chrysops x M. saxatilis) in response to hypoxia were evaluated in replicate tanks maintained at constant dissolved oxygen concentrations that averaged 23.0 ± 2.3%, 39.7 ± 3.0%, and 105.5 ± 9.5% dissolved oxygen saturation. Fish were fed a commercially formulated feed daily to apparent satiation. Total feed intake and fish growth and yield increased linearly in response to increased dissolved oxygen concentration. Nutrient utilization was reduced significantly only at the greatest level of hypoxia. With the exception of whole-body protein content, whole body compositional indices and nutrient retention efficiencies were linearly related to dissolved oxygen concentration. Results demonstrate that as hypoxia becomes more severe, juvenile hybrid striped bass feed intake is reduced, which affects growth and nutrient retention

    Hepatic Transcriptomic and Metabolic Responses of Hybrid Striped Bass (Morone saxatilis × Morone chrysops) to Acute and Chronic Hypoxic Insult

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    Striped bass (Morone saxatilis), white bass (Morone chrysops), and their hybrid are an important group of fish prized for recreational angling in the United States, and there and abroad as a high-value farmed fish. Regardless of habitat, it is not uncommon for fish of the genus Morone to encounter and cope with conditions of scarce oxygen availability. Previously, we determined that hybrid striped bass reared under conditions of chronic hypoxia exhibited reduced feed intake, lower lipid and nutrient retention, and poor growth. To better understand the molecular mechanisms governing these phenotypes, in the present study, we examined the transcriptomic profiles of hepatic tissue in hybrid striped bass exposed to chronic hypoxia (90 days at 25% oxygen saturation) and acute hypoxia (6 h at 25% oxygen saturation). Using high-throughput RNA-seq, we found that over 1400 genes were differentially expressed under disparate oxygen conditions, with the vast majority of transcriptional changes occurring in the acute hypoxia treatment. Gene pathway and bioenergetics analyses revealed hypoxia-mediated perturbation of genes and gene networks related to lipid metabolism, cell death, and changes in hepatic mitochondrial content and cellular respiration. This study offers a more comprehensive view of the temporal and tissue-specific transcriptional changes that occur during hypoxia, and reveals new and shared mechanisms of hypoxia tolerance in teleosts

    Harnessing Uncertainty in Radiotherapy Auto-Segmentation Quality Assurance

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    One of the key contributions of this study is the reappropriation of standard DL outputs as a quality indicator to identify cases that clinicians should review further. The authors achieve this by applying an empirically derived threshold to the softmax output of their DL network, computing the mean of the thresholded score map (termed the HiS metric), and correlating it with standard geometric quality indices. When juxtaposed with a mean entropy — a commonly used measure of model output uncertainty — HiS consistently demonstrated a stronger correlation with the geometric indices, suggesting its superior ability to stratify cases needing additional review. We applaud the authors\u27 efforts for their novel contributions and would like to note some potential caveats that could pave the way for future research directions

    Evolving Horizons in Radiation Therapy Auto-Contouring: Distilling Insights, Embracing Data-Centric Frameworks, and Moving Beyond Geometric Quantification

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    Historically, clinician-derived contouring of tumors and healthy tissues has been crucial for radiation therapy (RT) planning. In recent years, advances in artificial intelligence (AI), predominantly in deep learning (DL), have rapidly improved automated contouring for RT applications, particularly for routine organs-at-risk.1, 2, 3 Despite research efforts actively promoting its broader acceptance, clinical adoption of auto-contouring is not yet standard practice. Notably, within several AI communities, there has been growing enthusiasm to shift from conventional “model-centric” AI approaches (ie, improving a model while keeping the data fixed), to “data-centric” AI approaches (ie, improving the data while keeping a model fixed).4 Although balancing both approaches is typically ideal for crafting the optimal solution for specific-use cases, most research in RT auto-contouring has prioritized algorithmic modifications aimed at enhancing quantitative contouring performance based on geometric (ie, structural overlap) indices5—a clear testament to the “model-centric” AI paradigm. In this editorial, aimed at clinician end-users and multidisciplinary research teams, we harmonize key insights in contemporary RT auto-contouring algorithmic development to promote the adoption of data-centric AI frameworks for impactful future research directions that would further facilitate clinical acceptance. Of note, the discussion herein draws primarily from literature related to head and neck cancer (HNC), showcasing it as a representative example of a complex disease site. However, these insights apply broadly to auto-contouring across disease sites

    Breaking Open the Black Boxes: media archaeology, anarchaeology and media materiality

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    An essay on the emergent methodology of media archaeology, in relation to the material turn in approaches to digital media. In particular, this article advocates taking up Siegfried Zielinski's concept of 'anarchaeology', but in a different sense to the way it was originally proposed, in order to emphasise the political potentials of a media (an)archaeological methodological approach

    The screen test 1915–1930:how stars were born

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    This article examines the emergence of the screen test as a cultural phenomenon during the silent era in the US and Europe and its role in the development of the star system. The lore that grew up around the screen test almost from its inception held out the possibility for members of the public to cross a threshold into the rarefied world of celebrity. The screen test itself is situated in the liminal space not only between audience and actor, but also between fiction and non-fiction, Europe and Hollywood, the silent era and the talkies, and the public and private spheres. In order to trace the ways in which the screen test as such was narrativized and conceptualized in its foundational stages, this article will analyse accounts from Hollywood and European fan magazines of the silent era, including articles, short fiction, and early cinema apocrypha. The article culminates in a discussion of the film Prix de Beauté / Beauty Prize (Augusto Genina, 1930), which starred Louise Brooks, herself a transnational film icon whose film career spanned the divide between Hollywood and Europe. The film’s final scene, in which a beauty queen is shot dead by her jealous husband as she watches a screen test of herself, has been invoked by a number of film scholars as an allegory of the work performed by cinema, which preserves and disseminates the image of the star far beyond the actor’s physical presence. Speaking to historical conditions of star-making while also capturing its resonance in cultural mythology, the conclusion of Prix de Beauté allows us to consider the origins and functions of screen test discourse itself

    Estimation of the national disease burden of influenza-associated severe acute respiratory illness in Kenya and Guatemala : a novel methodology

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    Background: Knowing the national disease burden of severe influenza in low-income countries can inform policy decisions around influenza treatment and prevention. We present a novel methodology using locally generated data for estimating this burden. Methods and Findings: This method begins with calculating the hospitalized severe acute respiratory illness (SARI) incidence for children <5 years old and persons ≥5 years old from population-based surveillance in one province. This base rate of SARI is then adjusted for each province based on the prevalence of risk factors and healthcare-seeking behavior. The percentage of SARI with influenza virus detected is determined from provincial-level sentinel surveillance and applied to the adjusted provincial rates of hospitalized SARI. Healthcare-seeking data from healthcare utilization surveys is used to estimate non-hospitalized influenza-associated SARI. Rates of hospitalized and non-hospitalized influenza-associated SARI are applied to census data to calculate the national number of cases. The method was field-tested in Kenya, and validated in Guatemala, using data from August 2009–July 2011. In Kenya (2009 population 38.6 million persons), the annual number of hospitalized influenza-associated SARI cases ranged from 17,129–27,659 for children <5 years old (2.9–4.7 per 1,000 persons) and 6,882–7,836 for persons ≥5 years old (0.21–0.24 per 1,000 persons), depending on year and base rate used. In Guatemala (2011 population 14.7 million persons), the annual number of hospitalized cases of influenza-associated pneumonia ranged from 1,065–2,259 (0.5–1.0 per 1,000 persons) among children <5 years old and 779–2,252 cases (0.1–0.2 per 1,000 persons) for persons ≥5 years old, depending on year and base rate used. In both countries, the number of non-hospitalized influenza-associated cases was several-fold higher than the hospitalized cases. Conclusions: Influenza virus was associated with a substantial amount of severe disease in Kenya and Guatemala. This method can be performed in most low and lower-middle income countries

    Migalastat HCl Reduces Globotriaosylsphingosine (Lyso-Gb(3)) in Fabry Transgenic Mice and in the Plasma of Fabry Patients

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    Fabry disease (FD) results from mutations in the gene (GLA) that encodes the lysosomal enzyme α-galactosidase A (α-Gal A), and involves pathological accumulation of globotriaosylceramide (GL-3) and globotriaosylsphingosine (lyso-Gb3). Migalastat hydrochloride (GR181413A) is a pharmacological chaperone that selectively binds, stabilizes, and increases cellular levels of α-Gal A. Oral administration of migalastat HCl reduces tissue GL-3 in Fabry transgenic mice, and in urine and kidneys of some FD patients. A liquid chromatography-tandem mass spectrometry method was developed to measure lyso-Gb3 in mouse tissues and human plasma. Oral administration of migalastat HCl to transgenic mice reduced elevated lyso-Gb3 levels up to 64%, 59%, and 81% in kidney, heart, and skin, respectively, generally equal to or greater than observed for GL-3. Furthermore, baseline plasma lyso-Gb3 levels were markedly elevated in six male FD patients enrolled in Phase 2 studies. Oral administration of migalastat HCl (150 mg QOD) reduced urine GL-3 and plasma lyso-Gb3 in three subjects (range: 15% to 46% within 48 weeks of treatment). In contrast, three showed no reductions in either substrate. These results suggest that measurement of tissue and/or plasma lyso-Gb3 is feasible and may be warranted in future studies of migalastat HCl or other new potential therapies for FD
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