19 research outputs found
Divergent patterns of abundance and age-class structure of headwater stream tadpoles in burned and unburned watersheds
A harmonized segmentation protocol for hippocampal and parahippocampal subregions : why do we need one and what are the key goals?
The advent of high-resolution magnetic resonance imaging (MRI) has enabled in vivo research in a variety of populations and diseases on the structure and function of hippocampal subfields and subdivisions of the parahippocampal gyrus. Because of the many extant and highly discrepant segmentation protocols, comparing results across studies is difficult. To overcome this barrier, the Hippocampal Subfields Group was formed as an international collaboration with the aim of developing a harmonized protocol for manual segmentation of hippocampal and parahippocampal subregions on high-resolution MRI. In this commentary we discuss the goals for this protocol and the associated key challenges involved in its development. These include differences among existing anatomical reference materials, striking the right balance between reliability of measurements and anatomical validity, and the development of a versatile protocol that can be adopted for the study of populations varying in age and health. The commentary outlines these key challenges, as well as the proposed solution of each, with concrete examples from our working plan. Finally, with two examples, we illustrate how the harmonized protocol, once completed, is expected to impact the field by producing measurements that are quantitatively comparable across labs and by facilitating the synthesis of findings across different studies. © 2016 Wiley Periodicals, Inc.publishe
Hippocampal subfield volumetry from structural isotropic 1 mm3 MRI scans : A note of caution
Spurred by availability of automatic segmentation software, in vivo MRI investigations of human hippocampal subfield volumes have proliferated in the recent years. However, a majority of these studies apply automatic segmentation to MRI scans with approximately 1 × 1 × 1 mm3 resolution, a resolution at which the internal structure of the hippocampus can rarely be visualized. Many of these studies have reported contradictory and often neurobiologically surprising results pertaining to the involvement of hippocampal subfields in normal brain function, aging, and disease. In this commentary, we first outline our concerns regarding the utility and validity of subfield segmentation on 1 × 1 × 1 mm3 MRI for volumetric studies, regardless of how images are segmented (i.e., manually or automatically). This image resolution is generally insufficient for visualizing the internal structure of the hippocampus, particularly the stratum radiatum lacunosum moleculare, which is crucial for valid and reliable subfield segmentation. Second, we discuss the fact that automatic methods that are employed most frequently to obtain hippocampal subfield volumes from 1 × 1 × 1 mm3 MRI have not been validated against manual segmentation on such images. For these reasons, we caution against using volumetric measurements of hippocampal subfields obtained from 1 × 1 × 1 mm3 images
Produção de amônia na fermentação in vitro de rações com levedura, uréia ou farelo de algodão
Intrinsic, extrinsic, and amotivational orientations: Their role in university adjustment, stress, well-being, and subsequent academic performance
Pandémie grippale A/H5N1 et niveau de préparation du Niger : une étude sur les connaissances des soignants et l'organisation générale des soins
Dans les pays industrialisés, l'émergence de virus influenza à potentiel pandémique a suscité des réactions à la mesure de la menace que représentent ces agents infectieux. Cependant, à l'heure de la mondialisation, le contrôle des épidémies repose tout autant sur une coordination mondiale efficace des moyens de lutte que sur une préparation des systèmes de santé nationaux du Nord et du Sud, au centre desquels se trouvent les personnels soignants. Notre étude a pris place dans le principal hôpital nigérien, l'Hôpital national de Niamey. L'objectif était d'évaluer les connaissances des professionnels de soins en matière de pandémie grippale et de contrôle du risque infectieux. Sur la base d'un questionnaire, nous avons interrogé 178 soignants, médicaux et paramédicaux. Cette étude -- la première à notre connaissance à explorer ces questions dans le contexte africain -- a d'abord mis en lumière une certaine maîtrise des connaissances théoriques sur la grippe aviaire par les soignants. Cependant, au-delà des savoirs théoriques, l'enquête a également permis d'identifier des limites importantes compromettant les capacités de prévention et de lutte contre une pandémie grippale, notamment en termes d'organisation des soins et de contrôle du risque infectieux hospitalier
Current recognition and management of intra-abdominal hypertension and abdominal compartment syndrome among tertiary Chinese intensive care physicians*
This survey was designed to clarify the current understanding and clinical management of intra-abdominal hypertension (IAH)/abdominal compartment syndrome (ACS) among intensive care physicians in tertiary Chinese hospitals. A postal twenty-question questionnaire was sent to 141 physicians in different intensive care units (ICUs). A total of 108 (76.6%) questionnaires were returned. Among these, three quarters worked in combined medical-surgical ICUs and nearly 80% had primary training in internal or emergency medicine. Average ICU beds, annual admission, ICU length of stay, acute physiology and chronic health evaluation (APACHE) II score, and mortality were 18.2 beds, 764.5 cases, 8.3 d, 19.4, and 21.1%, respectively. Of the respondents, 30.6% never measured intra-abdominal pressure (IAP). Although the vast majority of the ICUs adopted the exclusively transvesicular method, the overwhelming majority (88.0%) only measured IAP when there was a clinical suspicion of IAH/ACS and only 29.3% measured either often or routinely. Moreover, 84.0% used the wrong priming saline volume while 88.0% zeroed at reference points which were not in consistence with the standard method for IAP monitoring recommended by the World Society of Abdominal Compartment Syndrome. ACS was suspected mainly when there was a distended abdomen (92%), worsening oliguria (80%), and increased ventilatory support requirement (68%). Common causes for IAH/ACS were “third-spacing from massive volume resuscitation in different settings” (88%), “intra-abdominal bleeding”, and “liver failure with ascites” (52% for both). Though 60% respondents would recommend surgical decompression when the IAP exceeded 25 mmHg, accompanied by signs of organ dysfunction, nearly three quarters of respondents preferred diuresis and dialysis. A total of 68% of respondents would recommend paracentesis in the treatment for ACS. In conclusion, urgent systematic education is absolutely necessary for most intensive care physicians in China to help to establish clear diagnostic criteria and appropriate management for these common, but life-threatening, diseases