323,091 research outputs found
Ocean acoustic circumpropagation in the ice seas of Europa
No full textIn recent years increased attention has been paid to the potential uses of acoustics forextraterrestrial exploration. A number of important papers have discussed propagationon Europa, primarily with respect to sound in the ice sheet which is believed to covera salt water ocean. The models used to date assume a flat ice surface and agravitational acceleration which does not vary with depth. Models of long rangeacoustic propagation through Europa’s ice seas require models which do not makethese two assumptions. This report applies such a model to simple Europangeometries to show how observables can be affected by the values of physicalparameters: the report considers the specific case of the effect on the travel time of acircumpropagating pulse of the ice and water thicknesses, and water temperature(assumed to be uniform), on a simple spherical planet. Such effects could be the basisof acoustic inversion experiments, although it is recognised that the complexities anduncertainties associated with the actual ice seas of Europa would make the task verymuch more challenging than the calculations undertaken in this simple study
An acoustical hypothesis for the spiral bubble nets of humpback whales and the implications for whale feeding
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Intensive insulin treatment
No full textHyperglycaemia is common in acute illness and more severe hyperglycaemia is associated with worse outcomes in critically ill patients in general and after acute myocardial infarction, stroke, and trauma. Normalization of blood glucose by intensive insulin therapy has been shown to reduce morbidity and mortality in one study in surgical intensive care patients; a subsequent study in medical intensive care patients resulted in reduced morbidity but not a reduction in mortality. Multicentre studies and current meta-analyses in the critically ill have not demonstrated improved outcomes when normalization of blood glucose was targeted; furthermore all studies to date have detected an increased risk of hypoglycaemia in patients subjected to intensive insulin therapy. At present, universal treatment guidelines or recommendations to target strict normoglycaemia must be considered premature. Further data will be available after the completion of the NICE-SUGAR study which has recruited 6103 patients; the NICE SUGAR study will add significant power to future meta-analyses and may help define the role of intensive insulin therapy in critically ill patients
Pathophysiology and causes of haemoptysis
No full textThe main goal of management of pleural effusion is to provide symptomatic relief removing fluid from pleural space and the options depend on type, stage and underlying disease. The first diagnostic instrument is the chest radiography while ultrasound can be very useful to guide thoracentesis. Pleural effusion can be a transudate or an exudate. Generally a transudate is uncomplicated effusion treated by medical therapy, while an exudative effusion is considered complicated effusion and should be managed by drainage. Refractory non-malignant effusions can be transudative (congestive heart failure, cirrhosis, nephrosis) or exudative (pancreatitis, connective tissue disease, endocrine dysfunction), and the management options include repeated therapeutic thoracentesis, indwelling pleural catheter for intermittent external drainage, pleuroperitoneal shunts for internal drainage, or surgical pleurectomy. Parapneumonic pleural effusions can be divided in complicated when there is persistent bacterial invasion of the pleural space, uncomplicated and empyema with specific indications for pleural fluid drainage. Malignancy is the most common cause of exudative pleural effusions in patients aged >60 years and the decision to treat depends upon the presence of symptoms and the underlying tumour type. Options include indwelling pleural catheter drainage, pleurodesis, pleurectomy and pleuroperitoneal shunt. Hemothorax needs to be differentiated from a haemorrhagic pleural effusion and when is suspected the essential management is the intercostal drainage. It achieves two objectives to drain the pleural space allowing expansion of the lung and to allow assessment of rates of blood loss to evaluate the need for emergency or urgent thoracotomy
Diffusive author(s), cohesive author: Analysis of S/N (1994)
No full textThis study indicates the ways in which various aspects of the author(s) are brought forth in Dumb type’s performance art, the S/N production. Previous research has suggested a non-hierarchical organization of Dumb type and the absence of a “privileged author” in Dumb type’s collaborative work, S/N. However, the results that I have investigated from member’s interviews on the creative process of S/N along with my analysis of the recorded images of S/N, indicate a different aspect of the author(s). First, S/N was created through, so to speak, the collective ideas of the members of Dumb type. Further, S/N has at least nine quotations from previous performances, installations, and printed writings, besides the work-in-progress technique. Explicating one of the “author functions” as given by Michel Foucault, each text has plural subjects of the author. However, it has been revealed from members’ interviews that Teiji Furuhashi had a decision-making role in selecting the members’ ideas within the performance. Since then, S/N has had plural subjects of creation; however, Furuhashi is one of the subjects of creation along with the “privileged author.” S/N has plural authors (diffusive authors) yet at the same time, it has a “privileged author,” Teiji Furuhashi (cohesive author)
Pathophysiology and therapeutic strategy of respiratory alkalosis
No full textRespiratory alkalosis is a condition characterized by low partial pressure of carbon dioxide and an associated elevation in arterial pH caused by an imbalance between CO2 production and removal, in favour of the latter. Conditions that cause increased alveolar ventilation, without having a reduction in pH as input stimulus, will cause hypocapnia associated with a variable degree of alkalosis. The major effect of hypocapnia is the increase in pH (alkalosis) and the consequent shift of electrolytes that occurs in relation to it. As a general law, in plasma, anions will increase, while cations will decrease. The acute reduction in ionized calcium, due to the change in extracellular pH, may cause neuromuscular symptoms ranging from paraesthesias, to tetany and seizures. The effect on urine is an increase in urinary strong ion difference/urinary anion gap and a consequent increase in urinary pH. Finally, acute hypocapnic alkalosis causes a constriction of cerebral arteries that can lead to a reduction of cerebral blood flow. The clinical approach to respiratory alkalosis is usually directed toward the diagnosis and treatment of the underlying clinical disorder
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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