Osteology and digital reconstruction of the skull of the early tetrapod Whatcheeria deltae

The Early Carboniferous stem tetrapod Whatcheeria deltae is among the earliest-branching limbed tetrapods represented by multiple near-complete specimens, making it an important taxon in understanding the vertebrate water-to-land transition. However, all preserved skulls of Whatcheeria suffer from post-mortem crushing and lateral compression, which has made cranial reconstruction problematic. In this study, computed tomography data of three Whatcheeria specimens were segmented using visualization software to digitally separate each individual skull bone from matrix. Digital methods were used to repair and retrodeform the bones and produce the first complete three-dimensional skull reconstruction of Whatcheeria. We provide a revised description of the cranial and lower jaw anatomy of Whatcheeria based on CT data, focusing on sutural morphology and previously unknown anatomical details. Our findings suggest that Whatcheeria had one of the narrowest skulls of any known early tetrapod, a gap between the nasals, and significant overlap of the lacrimal onto the nasal and prefrontal. Sutural morphology is used to infer loading regime in the skull during feeding and suggests the skull of Whatcheeria was well adapted to resist stresses induced by biting large prey with its enlarged anterior fangs

Patient-Reported Outcome questionnaires for hip arthroscopy: a systematic review of the psychometric evidence

Abstract Background Hip arthroscopies are often used in the treatment of intra-articular hip injuries. Patient-reported outcomes (PRO) are an important parameter in evaluating treatment. It is unclear which PRO questionnaires are specifically available for hip arthroscopy patients. The aim of this systematic review was to investigate which PRO questionnaires are valid and reliable in the evaluation of patients undergoing hip arthroscopy. Methods A search was conducted in Pubmed, Medline, CINAHL, the Cochrane Library, Pedro, EMBASE and Web of Science from 1931 to October 2010. Studies assessing the quality of PRO questionnaires in the evaluation of patients undergoing hip arthroscopy were included. The quality of the questionnaires was evaluated by the psychometric properties of the outcome measures. The quality of the articles investigating the questionnaires was assessed by the COSMIN list. Results Five articles identified three questionnaires; the Modified Harris Hip Score (MHHS), the Nonarthritic Hip Score (NAHS) and the Hip Outcome Score (HOS). The NAHS scored best on the content validity, whereas the HOS scored best on agreement, internal consistency, reliability and responsiveness. The quality of the articles describing the HOS scored highest. The NAHS is the best quality questionnaire. The articles describing the HOS are the best quality articles. Conclusions This systematic review shows that there is no conclusive evidence for the use of a single patient-reported outcome questionnaire in the evaluation of patients undergoing hip arthroscopy. Based on available psychometric evidence we recommend using a combination of the NAHS and the HOS for patients undergoing hip arthroscopy.</p

Wilson Lines and a Canonical Basis of SU(4) Heterotic Standard Models

The spontaneous breaking of SU(4) heterotic standard models by Z_3 x Z_3 Wilson lines to the MSSM with three right-handed neutrino supermultiplets and gauge group SU(3)_C x SU(2)_L x U(1) x U(1) is explored. The two-dimensional subspace of the Spin(10) Lie algebra that commutes with su(3)_C + su(2)_L is analyzed. It is shown that there is a unique basis for which the initial soft supersymmetry breaking parameters are uncorrelated and for which the U(1) x U(1) field strengths have no kinetic mixing at any scale. If the Wilson lines "turn on" at different scales, there is an intermediate regime with either a left-right or a Pati-Salam type model. We compute their spectra directly from string theory, and adjust the associated mass parameter so that all gauge parameters exactly unify. A detailed analysis of the running gauge couplings and soft gaugino masses is presented.Comment: 59 pages, 9 figure

Habitat structure: a fundamental concept and framework for urban soil ecology

Habitat structure is defined as the composition and arrangement of physical matter at a location. Although habitat structure is the physical template underlying ecological patterns and processes, the concept is relatively unappreciated and underdeveloped in ecology. However, it provides a fundamental concept for urban ecology because human activities in urban ecosystems are often targeted toward management of habitat structure. In addition, the concept emphasizes the fine-scale, on-the-ground perspective needed in the study of urban soil ecology. To illustrate this, urban soil ecology research is summarized from the perspective of habitat structure effects. Among the key conclusions emerging from the literature review are: (1) habitat structure provides a unifying theme for multivariate research about urban soil ecology; (2) heterogeneous urban habitat structures influence soil ecological variables in different ways; (3) more research is needed to understand relationships among sociological variables, habitat structure patterns and urban soil ecology. To stimulate urban soil ecology research, a conceptual framework is presented to show the direct and indirect relationships among habitat structure and ecological variables. Because habitat structure serves as a physical link between sociocultural and ecological systems, it can be used as a focus for interdisciplinary and applied research (e.g., pest management) about the multiple, interactive effects of urbanization on the ecology of soils

Workflow to improve patient recruitment for clinical trials within hospital information systems – a case-study

<p>Abstract</p> <p>Background</p> <p>The identification of suitable patients is a common problem in clinical trials that is especially evident in tertiary care hospitals.</p> <p>Methods</p> <p>We developed and analysed a workflow, which uses routine data captured during patient care in a hospital information system (HIS), to identify potential trial subjects. Study nurses or physicians are notified automatically by email and verify eligibility.</p> <p>Results</p> <p>As a case study we implemented the system for acute myeloid leukemia (AML) trials in Münster. During a test period of 50 days 41 patients were identified by the system. 13 could be included as new trial patients, 7 were already included during earlier visits. According to review of paper records no AML trial patient was missed by the system. In addition, the hospital information system further allowed to preselect patients for specific trials based on their disease status and individual characteristics.</p> <p>Conclusion</p> <p>Routine HIS data can be used to support patient recruitment for clinical trials by means of an automated notification workflow.</p

User needs elicitation via analytic hierarchy process (AHP). A case study on a Computed Tomography (CT) scanner

Background: The rigorous elicitation of user needs is a crucial step for both medical device design and purchasing. However, user needs elicitation is often based on qualitative methods whose findings can be difficult to integrate into medical decision-making. This paper describes the application of AHP to elicit user needs for a new CT scanner for use in a public hospital. Methods: AHP was used to design a hierarchy of 12 needs for a new CT scanner, grouped into 4 homogenous categories, and to prepare a paper questionnaire to investigate the relative priorities of these. The questionnaire was completed by 5 senior clinicians working in a variety of clinical specialisations and departments in the same Italian public hospital. Results: Although safety and performance were considered the most important issues, user needs changed according to clinical scenario. For elective surgery, the five most important needs were: spatial resolution, processing software, radiation dose, patient monitoring, and contrast medium. For emergency, the top five most important needs were: patient monitoring, radiation dose, contrast medium control, speed run, spatial resolution. Conclusions: AHP effectively supported user need elicitation, helping to develop an analytic and intelligible framework of decision-making. User needs varied according to working scenario (elective versus emergency medicine) more than clinical specialization. This method should be considered by practitioners involved in decisions about new medical technology, whether that be during device design or before deciding whether to allocate budgets for new medical devices according to clinical functions or according to hospital department

Superior canal dehiscence in a patient with three failed stapedectomy operations for otosclerosis: a case report

<p>Abstract</p> <p>Introduction</p> <p>This case illustrates that superior semicircular canal dehiscence syndrome can be associated with a "pseudo"-conductive hearing loss, a symptom that overlaps with the clinical appearance of otosclerosis.</p> <p>Case presentation</p> <p>We present the case of a 48-year-old German Caucasian woman presenting with hearing loss on the left side and vertigo. She had undergone three previous stapedectomies for hearing improvement. Reformatted high-resolution computed tomographic scanning and the patient's history confirmed the diagnosis of concurrent canal dehiscence syndrome.</p> <p>Conclusion</p> <p>Failure of hearing improvement after otosclerosis surgery may indicate an alternative underlying diagnosis which should be explored by further appropriate evaluation.</p

Development and validation of a reinforcement learning algorithm to dynamically optimize mechanical ventilation in critical care.

The aim of this work was to develop and evaluate the reinforcement learning algorithm VentAI, which is able to suggest a dynamically optimized mechanical ventilation regime for critically-ill patients. We built, validated and tested its performance on 11,943 events of volume-controlled mechanical ventilation derived from 61,532 distinct ICU admissions and tested it on an independent, secondary dataset (200,859 ICU stays; 25,086 mechanical ventilation events). A patient "data fingerprint" of 44 features was extracted as multidimensional time series in 4-hour time steps. We used a Markov decision process, including a reward system and a Q-learning approach, to find the optimized settings for positive end-expiratory pressure (PEEP), fraction of inspired oxygen (FiO2) and ideal body weight-adjusted tidal volume (Vt). The observed outcome was in-hospital or 90-day mortality. VentAI reached a significantly increased estimated performance return of 83.3 (primary dataset) and 84.1 (secondary dataset) compared to physicians' standard clinical care (51.1). The number of recommended action changes per mechanically ventilated patient constantly exceeded those of the clinicians. VentAI chose 202.9% more frequently ventilation regimes with lower Vt (5-7.5 mL/kg), but 50.8% less for regimes with higher Vt (7.5-10 mL/kg). VentAI recommended 29.3% more frequently PEEP levels of 5-7 cm H2O and 53.6% more frequently PEEP levels of 7-9 cmH2O. VentAI avoided high (>55%) FiO2 values (59.8% decrease), while preferring the range of 50-55% (140.3% increase). In conclusion, VentAI provides reproducible high performance by dynamically choosing an optimized, individualized ventilation strategy and thus might be of benefit for critically ill patients