104 research outputs found

    Work in Hypoxic Conditions-Consensus Statement of the Medical Commission of the Union Internationale des Associations d'Alpinisme (UIAA MedCom)

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    Objectives: The Commission gives recommendations on how to provide health and safety for employees in different kinds of low oxygen atmospheres. So far, no recommendations exist that take into account the several factors we have outlined in this report. Methods: The health and safety recommendations of several countries were analysed for their strength and deficiencies. The scientific literature was checked (Medline, etc.) and evaluated for relevance of the topic. Typical situations of work in hypoxia were defined and their specific risks described. Specific recommendations are provided for any of these situations. Results: We defined four main groups with some subgroups (main risk in brackets): short exposure (pressure change), limited exposure (acute altitude disease), expatriates (chronic altitude disease), and high-altitude populations (re-entry pulmonary oedema). For healthy unacclimatized persons, an acute but limited exposure down to 13% O2 does not cause a health risk. Employees should be advised to leave hypoxic areas for any break, if possible. Detailed advice is given for any other situation and pre-existing diseases. Conclusions: If the specific risk of the respective type of hypoxia is taken into account, a pragmatic approach to provide health and safety for employees is possible. In contrast to other occupational exposures, a repeated exposure as often as possible is of benefit as it causes partial acclimatization. The consensus statement was approved by written consent in lieu of a meeting in July 200

    Function Identification in Neuron Populations via Information Bottleneck

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    It is plausible to hypothesize that the spiking responses of certain neurons represent functions of the spiking signals of other neurons. A natural ensuing question concerns how to use experimental data to infer what kind of a function is being computed. Model-based approaches typically require assumptions on how information is represented. By contrast, information measures are sensitive only to relative behavior: information is unchanged by applying arbitrary invertible transformations to the involved random variables. This paper develops an approach based on the information bottleneck method that attempts to find such functional relationships in a neuron population. Specifically, the information bottleneck method is used to provide appropriate compact representations which can then be parsed to infer functional relationships. In the present paper, the parsing step is specialized to the case of remapped-linear functions. The approach is validated on artificial data and then applied to recordings from the motor cortex of a macaque monkey performing an arm-reaching task. Functional relationships are identified and shown to exhibit some degree of persistence across multiple trials of the same experiment

    Diagnostic confusion resolved by being upbeat

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    The classical stroke presentation – captured by the public health campaign mnemonic FAST (face, arm, speech, time) – does not apply in a large number of stroke cases; yet establishing a prompt diagnosis is imperative for optimal management. Here, we describe a patient with acute bulbar weakness, numbness in all extremities and an apparently normal magnetic resonance imaging (MRI) of the brain upon admission for whom even the fundamental question of whether this reflected a central or peripheral nervous system process was unclear. The critical localizing sign was upbeat nystagmus that denotes a brainstem cause. MRI of the brain in the second week confirmed a diagnosis of medial medullary infarction

    Radon study around earthquake affected areas of Nepal

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    Indoor radon concentrations were measured in dwellings of the earthquake-affected areas of Kathmandu valley, Gorkha, and Sindhupalchowk districts of Nepal using passive radon dosimeter LR115, a Solid State Nuclear Track Detector, SSNTD. The radon concentrations in dwellings of Kathmandu valley ranged from 11±6 Bq/m3 to 135±26 Bq/m3 with a mean of 67.63 Bq/m3. For  Gorkha, it ranged from 18±7 Bq/m3 to 363±65 Bq/m3 with an average of 104.64 Bq/m3 while minimum, maximum and average radon concentrations for Sindhupalchowk were 14±6 Bq/m3, 397±71 Bq/m3, and 78.46 Bq/m3 respectively. The average annual effective dose to the inhabitants of Kathmandu valley, Gorkha, and Sindhupalchowk districts was calculated as 1.46 mSv/y, 2.26 mSv/y, and 1.69 mSv/y respectively. These annual doses were well below the action level of 10 mSv/y recommended by the International Commission on Radiological Protection which implies no significant radiological health hazards. Also, Excess Lifetime Cancer Risk and Lungs Cancer Cases per year per million people were determined. BIBECHANA 18 (2) (2021) 61-6

    Radon study around earthquake affected areas of Nepal

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    Indoor radon concentrations were measured in dwellings of the earthquake-affected areas of Kathmandu valley, Gorkha, and Sindhupalchowk districts of Nepal using passive radon dosimeter LR115, a Solid State Nuclear Track Detector, SSNTD. The radon concentrations in dwellings of Kathmandu valley ranged from 11±6 Bq/m3 to 135±26 Bq/m3 with a mean of 67.63 Bq/m3. For  Gorkha, it ranged from 18±7 Bq/m3 to 363±65 Bq/m3 with an average of 104.64 Bq/m3 while minimum, maximum and average radon concentrations for Sindhupalchowk were 14±6 Bq/m3, 397±71 Bq/m3, and 78.46 Bq/m3 respectively. The average annual effective dose to the inhabitants of Kathmandu valley, Gorkha, and Sindhupalchowk districts was calculated as 1.46 mSv/y, 2.26 mSv/y, and 1.69 mSv/y respectively. These annual doses were well below the action level of 10 mSv/y recommended by the International Commission on Radiological Protection which implies no significant radiological health hazards. Also, Excess Lifetime Cancer Risk and Lungs Cancer Cases per year per million people were determined. BIBECHANA 18 (2) (2021) 61-6

    Identification of Immunogenic Salmonella enterica Serotype Typhi Antigens Expressed in Chronic Biliary Carriers of S. Typhi in Kathmandu, Nepal

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    Background: Salmonella enterica serotype Typhi can colonize and persist in the biliary tract of infected individuals, resulting in a state of asymptomatic chronic carriage. Chronic carriers may act as persistent reservoirs of infection within a community and may introduce infection to susceptible individuals and new communities. Little is known about the interaction between the host and pathogen in the biliary tract of chronic carriers, and there is currently no reliable diagnostic assay to identify asymptomatic S. Typhi carriage. Methodology/Principal Findings To study host-pathogen interactions in the biliary tract during S. Typhi carriage, we applied an immunoscreening technique called in vivo-induced antigen technology (IVIAT), to identify potential biomarkers unique to carriers. IVIAT identifies humorally immunogenic bacterial antigens expressed uniquely in the in vivo environment, and we hypothesized that S. Typhi surviving in the biliary tract of humans may express a distinct antigenic profile. Thirteen S. Typhi antigens that were immunoreactive in carriers, but not in healthy individuals from a typhoid endemic area, were identified. The identified antigens included a number of putative membrane proteins, lipoproteins, and hemolysin-related proteins. YncE (STY1479), an uncharacterized protein with an ATP-binding motif, gave prominent responses in our screen. The response to YncE in patients whose biliary tract contained S. Typhi was compared to responses in patients whose biliary tract did not contain S. Typhi, patients with acute typhoid fever, and healthy controls residing in a typhoid endemic area. Seven of 10 (70%) chronic carriers, 0 of 8 bile culture-negative controls (0%), 0 of 8 healthy Bangladeshis (0%), and 1 of 8 (12.5%) Bangladeshis with acute typhoid fever had detectable anti-YncE IgG in blood. IgA responses were also present. Conclusions/Significance: Further evaluation of YncE and other antigens identified by IVIAT could lead to the development of improved diagnostic assays to identify asymptomatic S. Typhi carriers

    Stereochemical Basis for Engineered Pyrrolysyl-tRNA Synthetase and the Efficient in Vivo Incorporation of Structurally Divergent Non-native Amino Acids

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    bS Supporting Information Incorporation of Uaas into proteins using a host’s endogenoustranslation machinery opens the door to addressing questions with chemical precision that is unattainable using naturally occurring amino acids. This expanded toolset allows one to pose and answer more in-depth molecular questions without the limitations imposed by the 20 natural amino acids used in traditional mutagenic analyses.1,2 Aminoacyl-tRNA synthetases (RSs) obtained by structure-based engineering and directed evolution efficiently recognize and activate Uaas through ATP-dependent adenylation and subsequently catalyze transfer to their cognate tRNA. To date, more than 70 Uaas are now amenable to translational insertion into proteins in bacteria, yeast, or mammalian cells using these artificially evolved tRNA/ RS pairs.3 By choosing particular matching sets of tRNA/RSs from diverse organisms, the pairs can function in vivo in a
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