394 research outputs found

    CUTI-1: a novel tetraspan protein involved in C. elegans CUTicle formation and epithelial integrity

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    The nematode cuticle is a tough extracellular matrix composed primarily of cross-linked collagens and non-collagenous cuticulins. It is required for nematode motility and protection from the external environment. Little is known about how the complex process of cuticle formation has been adapted to the specialized requirements of the nematode cuticle, which is structurally and compositionally unique from other organisms. The C. elegans gene cuti-1 (CUTicle and epithelial Integrity) encodes a nematode-specific protein. We have shown that CUTI-1 is expressed in the epithelia and in seam cells. Within these tissues the expression of cuti-1 mRNA cycles throughout development in line with the molting cycle, a process that involves synthesis of a new cuticle. In addition, knockdown of cuti-1 by RNA interference (RNAi) results in worms that display post-embryonic phenotypes related to cuticle dysfunction and defects in epithelial integrity. This is one of the first reports of a nematode-specific protein involved in extracellular matrix formation. It provides further insight into how novel ways have evolved to regulate the formation of the cuticle, which is the primary protective barrier and skeletal component of nematodes

    Western corn rootworm pyrethroid resistance confirmed by aerial application simulations of commercial insecticides

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    The western corn rootworm (Diabrotica virgifera virgifera LeConte) (WCR) is a major insect pest of corn (Zea mays L.) in the United States (US) and is highly adaptable to multiple management tactics. A low level of WCR field-evolved resistance to pyrethroid insecticides has been confirmed in the US western Corn Belt by laboratory dose-response bioassays. Further investigation has identified detoxification enzymes as a potential part of the WCR resistance mechanism, which could affect the performance of insecticides that are structurally related to pyrethroids, such as organophosphates. Thus, the responses of pyrethroid-resistant and -susceptible WCR populations to the commonly used pyrethroid bifenthrin and organophosphate dimethoate were compared in active ingredient bioassays. Results revealed a relatively low level of WCR resistance to both active ingredients. Therefore, a simulated aerial application bioassay technique was developed to evaluate how the estimated resistance levels would affect performance of registered rates of formulated products. The simulated aerial application technique confirmed pyrethroid resistance to formulated rates of bifenthrin whereas formulated dimethoate provided optimal control. Results suggest that the relationship between levels of resistance observed in dose-response bioassays and actual efficacy of formulated product needs to be further explored to understand the practical implications of resistance

    Examining diagnostic tests: an evidence-based perspective

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    Diagnosis is an important aspect of physical therapist practice. Selecting tests that will provide the most accurate information and evaluating the results appropriately are important clinical skills. Most of the discussion in physical therapy to date has centered on defining diagnosis, with considerably less attention paid to elucidating the diagnostic process. Determining the best diagnostic tests for use in clinical situations requires an ability to appraise evidence in the literature that describes the accuracy and interpretation of the results of testing. Important issues for judging studies of diagnostic tests are not widely disseminated or adhered to in the literature. Lack of awareness of these issues may lead to misinterpretation of the results. The application of evidence to clinical practice also requires an understanding of evidence and its use in decision making. The purpose of this article is to present an evidence-based perspective on the diagnostic process in physical therapy. Issues relevant to the appraisal of evidence regarding diagnostic tests and integration of the evidence into patient management are presented. [Fritz JM, Wainner RS. Examining diagnostic tests: an evidence-based perspective. Phys Ther. 2001;81:1546 -156

    Climatic Controls on a Holocene Mercury Stable Isotope Sediment Record of Lake Titicaca

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    Mercury (Hg) records in sediment archives inform past patterns of Hg deposition and the anthropogenic contribution to global Hg cycling. Natural climate variations complicate the interpretation of past Hg accumulation rates (HgARs), warranting additional research. Here, we investigated Hg stable isotopes in a ca. 8k year-long sediment core of Lake Titicaca and combined isotopic data with organic biomarkers and biogeochemical measurements. A wet period in the early Holocene (8000-7300 BP) induced strong watershed erosion, leading to a high HgAR (20.2 ± 6.9 μg m -2 year -1 ), which exceeded the 20th century HgAR (8.4 ± 1.0 μg m -2 year -1 ). Geogenic Hg input dominated during the early Holocene ( f geog = 79%) and played a minor role during the mid- to late Holocene (4500 BP to present; f geog = 20%) when atmospheric Hg deposition dominated. Sediment Δ 200 Hg values and the absence of terrestrial lignin biomarkers suggest that direct lake uptake of atmospheric Hg(0), and subsequent algal scavenging of lake Hg, represented an important atmospheric deposition pathway (42%) during the mid- to late Holocene. During wet episodes of the late Holocene (2400 BP to present), atmospheric Hg(II) deposition was the dominant source of lake sediment Hg (up to 82%). Sediment Δ 199 Hg values suggest that photochemical reduction and re-emission of Hg(0) occurred from the lake surface. Hg stable isotopes show promise as proxies for understanding the history of Hg sources and transformations and help to disentangle anthropogenic and climate factors influencing HgAR observed in sediment archives

    Western corn rootworm pyrethroid resistance confirmed by aerial application simulations of commercial insecticides

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    The western corn rootworm (Diabrotica virgifera virgifera LeConte) (WCR) is a major insect pest of corn (Zea mays L.) in the United States (US) and is highly adaptable to multiple management tactics. A low level of WCR field-evolved resistance to pyrethroid insecticides has been confirmed in the US western Corn Belt by laboratory dose-response bioassays. Further investigation has identified detoxification enzymes as a potential part of the WCR resistance mechanism, which could affect the performance of insecticides that are structurally related to pyrethroids, such as organophosphates. Thus, the responses of pyrethroid-resistant and -susceptible WCR populations to the commonly used pyrethroid bifenthrin and organophosphate dimethoate were compared in active ingredient bioassays. Results revealed a relatively low level of WCR resistance to both active ingredients. Therefore, a simulated aerial application bioassay technique was developed to evaluate how the estimated resistance levels would affect performance of registered rates of formulated products. The simulated aerial application technique confirmed pyrethroid resistance to formulated rates of bifenthrin whereas formulated dimethoate provided optimal control. Results suggest that the relationship between levels of resistance observed in dose-response bioassays and actual efficacy of formulated product needs to be further explored to understand the practical implications of resistance

    Langweilige Dystopien in fiktiven Geographien

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    Dieser Artikel untersucht das Verhältnis zwischen räumlichem Eingeschlossensein und dystopischem Alltag in fiktionalen Filmen. Unser empirischer Ausgangspunkt ist die Darstellung des Eingeschlossenseins in den Filmen Parasite (2019) und Dogtooth (2009). Beide Filme erzählen mit düsterem Humor verflochtene Geschichten über Erfahrungen des Einschlusses in sozialen Hierarchien (Parasite) und patriarchalischen Strukturen (Dogtooth) sowie über den unmöglichen Versuch, aus diesen Ordnungen auszubrechen. Wir lesen diese Erfahrungen als langweilige Dystopien, also als Dystopien, die in den Alltag eingeschrieben sind und eine grausame Realität normalisieren. Wir nutzen die fiktionalen Erzählungen von Dogtooth und Parasite für eine kulturgeographische Analyse, die das Eingeschlossensein neben seinen räumlichen und materiellen Bedingungen als eine affektive Atmosphäre (Anderson 2014) versteht. Aufbauend auf der zunehmenden Stadtforschung über Affekte und Emotionen vermittelt dieser Zugang, wie das Eingeschlossensein sich als alltägliche, dystopische Erfahrung normalisiert. Wir argumentieren, dass eine Analyse affektiver Atmosphären die unsichtbar gewordenen Gewalterfahrungen des Eingeschlossenseins greifbar machen kann

    A Conceptual Definition of Vocational Rehabilitation Based on the ICF: Building a Shared Global Model

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    Background The International Classification of Functioning, Disability and Health (ICF) is a conceptual framework and classification system by the World Health Organization (WHO) to understand functioning. The objective of this discussion paper is to offer a conceptual definition for vocational rehabilitation (VR) based on the ICF. Method We presented the ICF as a model for application in VR and the rationale for the integration of the ICF. We also briefly reviewed other work disability models. Results Five essential elements of foci were found towards a conceptual definition of VR: an engagement or re-engagement to work, along a work continuum, involved health conditions or events leading to work disability, patient-centered and evidence-based, and is multi-professional or multidisciplinary. Conclusions VR refers to a multi-professional approach that is provided to individuals of working age with health-related impairments, limitations, or restrictions with work functioning and whose primary aim is to optimize work participation. We propose that the ICF and VR interface be explored further using empirical and qualitative works and encouraging stakeholders' participatio

    Holocene variations in Lake Titicaca water level and their implications for sociopolitical developments in the central Andes

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    Holocene climate in the high tropical Andes was characterized by both gradual and abrupt changes, which disrupted the hydrological cycle and impacted landscapes and societies. High-resolution paleoenvironmental records are essential to contextualize archaeological data and to evaluate the sociopolitical response of ancient societies to environmental variability. Middle-to-Late Holocene water levels in Lake Titicaca were reevaluated through a transfer function model based on measurements of organic carbon stable isotopes, combined with high-resolution profiles of other geochemical variables and paleoshoreline indicators. Our reconstruction indicates that following a prolonged low stand during the Middle Holocene (4000 to 2400 BCE), lake level rose rapidly ~15 m by 1800 BCE, and then increased another 3 to 6 m in a series of steps, attaining the highest values after ~1600 CE. The largest lake-level increases coincided with major sociopolitical changes reported by archaeologists. In particular, at the end of the Formative Period (500 CE), a major lake-level rise inundated large shoreline areas and forced populations to migrate to higher elevation, likely contributing to the emergence of the Tiwanaku culture
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