Feasibility of glioblastoma tissue response mapping with physiologic BOLD imaging using precise oxygen and carbon dioxide challenge

Magnetic Resonance Materials in Physics, Biology and Medicine - Innovative physiologic MRI development focuses on depiction of heterogenous vascular and metabolic features in glioblastoma. For this...     

Geothermal use of an Alpine aquifer—Davos pilot study

Grundwasser - Topographically induced Alpine regional groundwater flow systems below the unconsolidated valley fillings constitute a substantial unused geothermal resource. Within the...     

Distributed Coordination of First Responders

In a disaster scenario, first responders must be able to perform multiple functions in a coordinated way. At all levels of the task - from integrating heterogeneous systems to addressing response tasks and allocating resources - responders must be able to make decisions in a globally optimal fashion. Automated coordination mechanisms can help, but they still face several challenges that researchers must address to make them effective and useful. This article discusses the application of distributed constraint optimization in disaster management coordination.     

Effects of intermittent reperfusion on brain pHi, rCBF, and NADH during rabbit focal cerebral ischemia

BACKGROUND AND PURPOSE: The use of intermittent reperfusion versus straight occlusion during neurovascular procedures is controversial. This experiment studied the effects of intermittent reperfusion and single occlusion on intracellular brain pH (pHi), regional cerebral or cortical blood flow, and nicotinamide adenine dinucleotide (NADH) fluorescence during temporary focal ischemia. METHODS: Twenty fasted rabbits under 1.0% halothane anesthesia were divided into four groups: (1) nonischemic controls, (2) 60 minutes of uninterrupted focal ischemia, (3) 2 x 30-minute periods of focal ischemia separated by a 5-minute reperfusion, and (4) 4 x 15-minute periods of focal ischemia separated by three 5-minute reperfusion periods. Focal ischemia was produced by occlusion of both the middle cerebral and ipsilateral anterior cerebral arteries. After the final occlusion, there was a 3-hour reperfusion period in all groups. Regional cerebral and cortical blood flow, brain pHi, and NADH fluorescence were measured with in vivo panoramic fluorescence imaging. RESULTS: During occlusion, regional cerebral and cortical blood flows and NADH fluorescence values were not different among the groups. Brain pHi was significantly lower in the 4 x 15-minute group compared with the 1 x 60-minute group (6.57 +/- 0.02 versus 6.73 +/- 0.06; P < .03) but not significant when compared with the 2 x 30-minute group. During the short reperfusion periods, all parameters returned to normal except for NADH fluorescence levels, which remained elevated. During the postischemic final reperfusion period, there was a mild brain alkalosis of approximately 7.1 in all groups. There were no significant differences in NADH fluorescence among groups during the final reperfusion. Regional cerebral and cortical blood flow returned to near normal values in all groups. CONCLUSIONS: This study demonstrates that intermittent reperfusion during temporary focal ischemia has different effects on the intracytoplasmic and the intramitochondrial compartments: worsening of brain cytoplasmic pHi but no significant differences in the oxidation/reduction level of mitochondrial NADH.     

Encephalopathy during oral treatment with bismuth salts

Side effects of orally administered bismuthic salts have been known for many years. Many systems are involved, including the digestive and urinary. The authors discuss a recently discovered effect on the central nervous system, termed "bismuth encephalopathy". In the light of the medical literature reviewed, two original aspects are stressed: the clinical symptoms are stereotyped and completely reversible, and the distribution of the disease is almost epidemic, being limited in time and space. The prodromes include confusion, asthenia, slowing of mental functions and disturbance of gait. The clinical picture is dominated by four major symptoms: confusion (again), ataxia, dysarthria and, above all, myoclonic jerks. In conclusion, various pathogenetic hypotheses are considered. The purpose of this study is to enable the general practitioner to detect the development of this condition early in treatment with oral bismuthic salts. Withdrawal of the medication always results in normalization of the patient's condition.     

Range of neuromuscular involvement in 47 patients infected with the human immunodeficiency virus

Over a 30 month period, 47 out of 749 patients infected with the human immunodeficiency virus had various neuromuscular symptoms. Based on clinical and electrophysiological data, 47% had distal symmetric polyneuropathy, 11% chronic inflammatory demyelinating polyneuropathy (CIDP), 8.5% toxic neuropathy related to 2-3-dideoxyinosine (DDI), 8.5% cranial neuropathy, 8.5% mononeuropathy multiplex or isolated focal neuropathy, 8.5% progressive lumbosacral polyradiculopathy, and 8.5% myopathy. Half of the patients exhibited previous or concomitant signs of central nervous system involvement and 18 patients died during the study period. CIDP and cranial neuropathies usually appeared early in the course of the disease and consequently showed neurological improvement. Nerve conduction studies of DDI related toxic neuropathies showed distal axono-myelinic sensitivo-motor neuropathy, differing from CIDP by the absence of a conduction block. Distal symmetric polyneuropathies, frequent in the advanced systemic illness, do not systematically require an extended workup, but more unusual peripheral neuropathies which might be treatable necessitate further investigations (electromyography, radiology, serological blood tests; protein chemistry and routine workup of the cerebrospinal fluid). For example, progressive lumbosacral polyradiculopathies responded to early treatment, with a better outcome in one case of herpetic origin than in another case due to cytomegalovirus infection. Our observations suggest that myopathies in HIV infected patients should first be tackled by temporary interruption of virostatic medication, followed by muscle biopsy if the symptoms persist.     

Assessing the public health risk of microbial intrusion events in distribution systems: conceptual model, available data, and challenges

Low and negative pressure events in drinking water distribution systems have the potential to result in intrusion of pathogenic microorganisms if an external source of contamination is present (e.g., nearby leaking sewer main) and there is a pathway for contaminant entry (e.g., leaks in drinking water main). While the public health risk associated with such events is not well understood, quantitative microbial risk assessment can be used to estimate such risk. A conceptual model is provided and the state of knowledge, current assumptions, and challenges associated with the conceptual model parameters are presented. This review provides a characterization of the causes, magnitudes, durations and frequencies of low/negative pressure events; pathways for pathogen entry; pathogen occurrence in external sources of contamination; volumes of water that may enter through the different pathways; fate and transport of pathogens from the pathways of entry to customer taps; pathogen exposure to populations consuming the drinking water; and risk associated with pathogen exposure.     

On the long-term retention of geometry-centric digital engineering artifacts

This paper discusses the challenges of long-term preservation of digital geometric models and the engineering processes associated with them. For engineering, design, manufacturing, and physics-based simulation data this requires formats that are accessible potentially indefinitely into the future. One of the fundamental challenges is the development of digital geometry-centric engineering representations that are self describing and assured to be interpretable over the long lifespans required by archival applications. Additionally, future users may have needs that require other information, going beyond geometry, be also accessible to fully interpret the model. These problems are highly interdisciplinary and not exclusively algorithmic or technical. To provide context, the paper introduces a case study illustrating an overall portrait of the problem. Based on observations from this case study, we present a framework for enhancing the preservation of geometry-centric engineering knowledge. This framework is currently being used on a number of projects in engineering education.