Computed microtomography visualization and quantification of mouse ischemic brain lesion by nonionic radio contrast agents.

AIM: To explore the possibility of brain imaging by microcomputed tomography (microCT) using x-ray contrasting methods to visualize mouse brain ischemic lesions after middle cerebral artery occlusion (MCAO). ----- METHODS: Isolated brains were immersed in ionic or nonionic radio contrast agent (RCA) for 5 days and subsequently scanned using microCT scanner. To verify whether ex-vivo microCT brain images can be used to characterize ischemic lesions, they were compared to Nissl stained serial histological sections of the same brains. To verify if brains immersed in RCA may be used afterwards for other methods, subsequent immunofluorescent labeling with anti-NeuN was performed. ----- RESULTS: Nonionic RCA showed better gray to white matter contrast in the brain, and therefore was selected for further studies. MicroCT measurement of ischemic lesion size and cerebral edema significantly correlated with the values determined by Nissl staining (ischemic lesion size: P=0.0005; cerebral edema: P=0.0002). Brain immersion in nonionic RCA did not affect subsequent immunofluorescent analysis and NeuN immunoreactivity. ----- CONCLUSION: MicroCT method was proven to be suitable for delineation of the ischemic lesion from the non-infarcted tissue, and quantification of lesion volume and cerebral edema

Measurements of the effect of collisions on transverse beam halo diffusion in the Tevatron and in the LHC

Beam-beam forces and collision optics can strongly affect beam lifetime, dynamic aperture, and halo formation in particle colliders. Extensive analytical and numerical simulations are carried out in the design and operational stage of a machine to quantify these effects, but experimental data is scarce. The technique of small-step collimator scans was applied to the Fermilab Tevatron collider and to the CERN Large Hadron Collider to study the effect of collisions on transverse beam halo dynamics. We describe the technique and present a summary of the first results on the dependence of the halo diffusion coefficient on betatron amplitude in the Tevatron and in the LHC.Comment: 4 pages, 2 figures. Submitted to the Proceedings of the ICFA Mini-Workshop on Beam-beam Effects in Hadron Colliders (BB2013), Geneva, Switzerland, 18-22 March 201

Towards a Notion of Distributed Time for Petri Nets

We set the ground for research on a timed extension of Petri nets where time parameters are associated with tokens and arcs carry constraints that qualify the age of tokens required for enabling. The novelty is that, rather than a single global clock, we use a set of unrelated clocks --- possibly one per place --- allowing a local timing as well as distributed time synchronisation. We give a formal definition of the model and investigate properties of local versus global timing, including decidability issues and notions of processes of the respective models

Problem-solving in groups of common marmosets (Callithrix jacchus): more than the sum of its parts

Human hypercooperativity and the emergence of division of labor enables us to solve problems not only effectively within a group but also collectively. Collective problem-solving occurs when groups perform better than the additive performance of separate individuals. Currently, it is unknown whether this is unique to humans. To investigate the evolutionary origin of collective problem-solving and potential precursors, we propose a continuum of group effects on problem-solving, from simple to complex ones, eventually culminating in collective problem-solving. We tested captive common marmosets with a series of problem-solving tasks, either alone or in a group. To test whether the performance of a group was more than the sum of its parts, we compared real groups to virtual groups (pooled scores of animals tested alone). Marmosets in real groups were both more likely to solve problems than marmosets within the virtual groups and to do so faster. Although individuals within real groups approached the problem faster, a reduction in neophobia was not sufficient to explain the greater success. Success within real groups arose because animals showed higher perseverance, especially after a fellow group member had found the solution in complex tasks. These results are consistent with the idea that group problem-solving evolved alongside a continuum, with performance improving beyond baseline as societies move from social tolerance to opportunities for diffusion of information to active exchange of information. We suggest that increasing interdependence and the adoption of cooperative breeding pushed our ancestors up this scale

Wie beeinflussen Torfart, Sandeinmischung und Bodenfeuchte die Mineralisierung der organischen Bodensubstanz in anthropogen gestörten organischen Böden?

Entwässerte Moore sind Hotspots für Kohlendioxid (CO2)-Emissionen. Sowohl aufgrund von entwässerungsbedingter Mineralisierung als auch durch anthropogene Sandeinmischung liegt der Bodenkohlenstoffgehalt vieler ehemaliger Moore unter landwirtschaftlicher Nutzung an der Grenze zwischen mineralischen und organischen Böden. Studien zur Kohlenstoffdynamik solcher vergleichsweise kohlenstoffarmen organischen Böden sind selten. Allerdings weisen erste Studien auf eine steigende Variabilität der CO2-Emissionen bei stärkerer Störung hin. Auch wenn grundsätzliche Prozesse bekannt sind, fehlt bisher eine systematische Bewertung der hydrologischen und biogeochemischen Einflussfaktoren auf die CO2-Emissionen stark anthropogen gestörter Torfe. Ziel des vorgestellten Inkubationsversuches ist das bessere Verständnis der hohen Variabilität der CO2-Emissionen solcher Böden. Dafür werden systematisch stark degradierte Torfe aus unterschiedlichen Ausgangssubstraten mit und ohne Sandeinmischung unter verschiedenen Feuchtigkeitsbedingungen verglichen. An sechs Niedermoor- (Radizellen-, Schilf- und Holztorf) und vier Hochmoorstandorten (Sphagnumtorf) unter Grünlandnutzung wurden jeweils Triplikate ungestörter Bodensäulen aus Ober- und Unterboden entnommen. Alle Standorte haben einen intakten ständig wassergesättigten Unterbodenhorizont und einen stark gestörten Oberbodenhorizont. Der Oberboden von drei Niedermoor- und zwei Hochmoorstandorten ist durch Sandeinmischung verändert. Zusätzlich wurden Proben zur Bestimmung der bodenhydraulischen Eigenschaften genommen. Alle 64 Bodensäulen (inkl. vier Referenzproben) wurden in einer Mikrokosmenanlage unter konstanten Temperaturbedingungen (10° C) installiert. Die anfangs wassergesättigten Bodensäulen wurden über Saugplatten durch schrittweise Erhöhung des Unterdrucks entwässert. Der Headspace der Säulen wird permanent mit angefeuchteter synthetischer Luft gespült und CO2-Konzentrationen werden alle 8 h per Gaschromatographie gemessen

Indications and Relative Utility of Lower Endoscopy in the Management of Clostridium difficile Infection

Background. Diagnosis and management of Clostridium difficile infection (CDI) rely upon clinical assessments and diagnostic studies. Among diagnostic tests, lower gastrointestinal (GI) endoscopy in the setting of CDI remains controversial. Objective. To describe the role of lower endoscopy in CDI management. Methods. Retrospective study of lower endoscopies in CDI at four metropolitan hospitals, July 2005 through December 2007. Results. Of 1760 CDI inpatients, 45 lower endoscopies were performed on 43 patients. Most common indications were ruling out other etiologies (42%), inconclusive stool studies (36%), and worsening course (11%). Most endoscopies (73%) had positive findings, including pseudomembranous colitis (49%) and nonspecific colitis (24%). Biopsies were performed in 31 cases, more with nonspecific colitis (10/11, 92%) compared to pseudomembranous colitis (14/22, 64%). Conclusion. While not recommended as a primary screening tool, lower GI endoscopy can add valuable information in CDI when other colonic pathologies may exist, studies are inconclusive, or clinical status worsens

The Gulf Stream Front, Its Role in Larval Fish Survival and Recruitment in Florida: Hydrographic Station and Plankton Data

The goal of this project was to develop a clearer understanding of the role that the Gulf Stream system plays in larval fish survival and recruitment in Florida waters. The specific objectives of this study were to: Determine whether the biomass of fish larva, other zooplankton, microzooplankton and phytoplankton is higher at the shoreward front of the Gulf Stream than on either side of it. Characterize the assemblages of fish larvae predators and prey both at the front and on either side of it. Determine if the composition, abundance and size frequency distribution of larval and juvenile fishes in the front is different from that in the coastal zone or in the Gulf Stream. Monitor the position of the Gulf Stream by continuous measurements of physical variables at moorings located in the Gulf Stream off Fort Lauderdale and within Port Everglades. This project was a first effort to characterize the coupling between physical and biological processes that may influence the early life histories of fishes in Florida\u27s coastal waters. This report contains the hydrographic and plankton data from the project. It is intended to facilitate data access by the scientific and management communities. Interpretations and detailed analyses of these data are being given in meeting presentations, peer-reviewed journal articles (Stone et al. draft manuscript, Braker et al. draft manuscript, Frazel et al. in preparation) and graduate theses (Stone 1993; Braker 1993)

Identification, Motivation and Facilitation of Domestic Tourism in a Small Island

This paper presents a case concerning domestic tourism in the Isle of Man, British Isles; a small maritime nation with Norse heritage. Qualitative interviews find the existence of considerable domestic tourism activity conducted by island residents, including daytrips and overnight stays, and explore the motivational and facilitating factors which underpin this. Such behaviour is identified by residents as touristic and distinct from other leisure pursuits. Yet recognition of domestic tourism in small geographic spaces is currently almost entirely absent. This article attempts to highlight the issue and draw attention to attendant benefits of domestic tourism which include economic and social inputs. These may be relevant to a small island community, and in the case of the Isle of Man help to support an otherwise ailing tourism industry