Physiological and Histopathological Responses Following Closed Rotational Head Injury Depend on Direction of Head Motion

Rotational inertial forces are thought to be the underlying mechanism for most severe brain injuries. However, little is known about the effect of head rotation direction on injury outcomes, particularly in the pediatric population. Neonatal piglets were subjected to a single non-impact head rotation in the horizontal, coronal, or sagittal direction, and physiological and histopathological responses were observed. Sagittal rotation produced the longest duration of unconsciousness, highest incidence of apnea, and largest intracranial pressure increase, while coronal rotation produced little change, and horizontal rotation produced intermediate and variable derangements. Significant cerebral blood flow reductions were observed following sagittal but not coronal or horizontal injury compared to sham. Subarachnoid hemorrhage, ischemia, and brainstem pathology were observed in the sagittal and horizontal groups but not in a single coronal animal. Significant axonal injury occurred following both horizontal and sagittal rotations. For both groups, the distribution of injury was greater in the frontal and parietotemporal lobes than in the occipital lobes, frequently occurred in the absence of ischemia, and did not correlate with regional cerebral blood flow reductions. We postulate that these direction-dependent differences in injury outcomes are due to differences in tissue mechanical loading produced during head rotation

Non-linear resonances in spin-orbit coupling problems with three degrees of freedom

A system of vector and matrix differential equations is developed which may be applied to the problem of determining the spin-orbit state of the planet Mercury. Unlike previous studies, this system of equations may be analyzed without requiring that the spin axis remain perpendicular to the plane of the orbit;A specific average is defined and a transformation from the original system of equations to the averaged equations is shown to exist. Theorems are proved which relate certain characteristics of solutions of the original system to a condition on the averaged equations;The theorems are applied to sample problems which illustrate the extreme conditions which may be faced and which point out differences in the conclusions deduced from these opposite extreme cases;Mathematical models are developed to describe the physical system composed of Mercury and the sun. These models are consistent with those presented in previous studies by other authors. The theorems are applied to the mathematical models to obtain results which are consistent with the present understanding of the problem

Wirkungsanalyse des Deutsch-Peruanischen Gegenwertfonds

Der Deutsch-Peruanische Gegenwertfonds (FPA) beruht auf Umschuldungsabkommen, in denen die Bundesregierung Peru Schulden erlassen und Peru sich verpflichtet hatte, einen Teil der Erlasssumme in nationaler Währung für Vorhaben der Armutsbekämpfung einzusetzen. Der daraus gebildete FPA hatte zunächst eine Laufzeit von 2003 bis 2007 und wurde dann zweimal bis 2015 ver­längert. Er konzentriert sich auf besonders arme Gebiete Perus und hat drei Ziele: Verbesserung der Regierungsführung und Bürgerbeteiligung auf lokaler Ebene, Verbesserung der Trinkwasserversorgung und Abwasserentsorgung im ländlichen Raum sowie Verbesserung der Bewässerung in der kleinbäuerlichen Landwirtschaft. Die vorliegende Untersuchung zeigt zunächst, dass die Ziele des FPA entwicklungspolitisch relevant sind und die Organisationsform, die regionalen Schwerpunkte sowie die Grundsätze und Verfahren des FPA seinen Zielen entsprechen. Die Wirkungsanalyse bezog sich auf eine Auswahl von Projekten der ersten Phase und ergab, dass die Projekte alle relevant und zum größten Teil auch wirksam waren; allerdings ist die Nachhaltigkeit nicht immer gewährleistet. Abschließend erörtert die Studie aus systemischer Perspektive die ent­wicklungspolitische Rolle bila­teraler Gegenwertfonds, von denen es eine ganze Reihe in Peru und in anderen Entwicklungsländern gibt und die kontrovers diskutiert werden

A geospatial analysis of Arctic marine traffic

Recent changes in Arctic Ocean climate dynamics and marine activity in the region require re-evaluation of physical operating conditions, ship traffic patterns, and policy requirements. This study used (1) government surveys, (2) vessel reports, and (3) Automatic Identification System (AIS) messages to characterize the spatial and temporal variability of surface vessel traffic in relation to various sea-ice conditions on the Arctic Ocean during a year-long study from 1 April 2010 to 31 March 2011. Data sources, methods of analysis, and errors were discussed. Three principal topics were examined. First, sea-ice cover on the Arctic Ocean was analysed to determine the physical access for marine operations. Daily sea-ice concentration data based on satellite passive microwave measurements were used to calculate the extent of open water and duration of the sea-ice season. Second, ship traffic on the Arctic Ocean was analysed to determine the present patterns of human activity. Time-stamped AIS messages encoded with Global Navigation Satellite System (GNSS) positions received by a commercial satellite constellation from north of the Arctic Circle (66·56°N) were used to calculate the distribution of vessels per unit area. Satellite AIS data from SpaceQuest, Limited, were compared with land-based vessel observations during the study period from the Marine Exchange of Alaska and the Port of Longyearbyen. Third, the spatial and temporal relationship between sea ice and surface vessels on the Arctic Ocean was analysed to determine potential policy implications. Three groups of marine operations with distinct characteristics were determined from the analysis: operations in perennial open water, operations in the seasonal ice zone, and operations in the perennial ice zone. Throughout the study year, most ships north of 66·56°N operated in perennially icefree areas, but year-round operations also occurred in ice-covered areas. The results from this study identify new pathways of information to enable consistent pan-Arctic assessment of physical operating conditions and ship traffic patterns. This approach provides novel considerations to sustainably develop a safe, secure, and environmentally protected Arctic Ocean

Finite Element Model Predictions of Intracranial Hemorrhage From Non-impact, Rapid Head Rotations in the Piglet

Clinicians are charged with the significant task of distinguishing between accidental and inflicted head trauma. Oftentimes this distinction is straightforward, but many times probabilities of injuries from accidental scenarios are unknown making the differential diagnosis difficult. For example, it is unknown whether intracranial hemorrhage (IH) can occur at a location other than a focal contact site following a low height fall. To create a foundation for predicting regional IH in infants, we sought to identify the biomechanical response and injury threshold best able to predict IH in 3–5 day old piglets. First, finite element (FE) model simulations of in situ animal studies were performed to ascertain the optimal representation of the pia-arachnoid complex, cerebrospinal fluid and cortical vasculature (PCC) for predicting brain strain and brain/skull displacement. Second, rapid head rotations resulting in various degrees of IH were simulated (n = 24) to determine the biomechanical predictor and injury threshold most closely correlated with IH. FE models representing the PCC with either spring connectors or solid elements between the brain and skull resulted in peak brain strain and brain/skull displacement similar to measured values in situ. However, when predicting IH, the spring connector representation of the PCC had the best predictive capability for IH with a sensitivity of 80% and a specificity of 85% when ≥1% of all spring connectors had at least a peak strain of 0.31 mm/mm. These findings and reported methodology will be used in the development of a human infant FE model to simulate real-world falls and identify injury thresholds for predicting IH in infants

Der "Obama-Effekt" auf die Klimapolitik der neuen regionalen Führungsmächte

Die klimapolitische Position der USA hat sich seit der Übernahme des Präsidentenamtes durch Barack Obama grundlegend gewandelt. Dies betrifft sowohl innenpolitische Entwicklungen als auch den außenpolitischen Auftritt in zwischenstaatlichen und internationalen Klimaverhandlungen. Die veränderte Haltung hat einen direkten Einfluss auf Verhandlungspositionen der neuen regionalen Führungsmächte, insbesondere der beiden großen CO2-Emittenten China und Indien. Aber auch andere regionale Führungsmächte bleiben von dieser neuen Linie nicht unberührt: Brasilien, Südafrika und Venezuela ändern ihr Verhalten. Noch ist unklar, ob die neue Klimapolitik der USA einen entscheidenden Beitrag zum Beschluss eines neuen internationalen Klimaschutzabkommens im Dezember in Kopenhagen leisten wird

Diagnosis of bacterial vaginosis from self-obtained vaginal swabs.

OBJECTIVE: To determine the concordance between vaginal fluid Gram stains and pH obtained at speculum exam with similar stains and pH prepared from self-obtained vaginal swabs. METHODS: Using vaginal fluid Gram stain, 129 pregnant women were screened for bacterial vaginosis at 24 to 29 weeks' gestation. Two smears were collected from each woman during the same prenatal visit: the first was prepared from a self-obtained vaginal swab and the second from a physician-obtained speculum examination. Vaginal pH was recorded for each swab. Kappa coefficient was used to quantify agreement between the two sets of results. RESULTS: When compared with the physician-obtained smear, the ability of the self-obtained Gram stain to diagnose bacterial vaginosis had a sensitivity of 77%, specificity of 97%, positive predictive value of 71% and negative predictive value of 97%. There was substantial agreement (weighted kappa=0.82) between the two techniques in the ability to determine the grade of vaginal flora. CONCLUSION: When compared with physician-obtained vaginal smears, self-obtained smears have substantial agreement in the diagnosis of bacterial vaginosis