bluuebunny/crossref_metadata_2025 huggingface dataset:
Gelsolin Mediates Collagen Phagocytosis through a Rac-dependent Step
Authors: Arora Pamela D. , Glogauer Michael , Kapus Andras , Kwiatkowski David J. , McCulloch Christopher A.
Published: November 2003

The role of gelsolin, a calcium-dependent actin-severing protein, in mediating collagen phagocytosis, is not defined. We examined α2β1 integrin-mediated phagocytosis in fibroblasts from wild-type (WT) and gelsolin knockout (Gsn-) mice. After initial contact with collagen beads, collagen binding and internalization were 60% lower in Gsn-than WT cells. This deficiency was restored by transfection with gelsolin or with β1 integrin-activating antibodies. WT cells showed robust rac activation and increased [Ca2+]iduring early contact with collagen beads, but Gsn-cells showed very limited responses. Transfected gelsolin in Gsn-cells restored rac activation after collagen binding. Transfection of Gsn-cells with active rac increased collagen binding to WT levels. Chelation of intracellular calcium inhibited collagen binding and rac activation, whereas calcium ionophore induced rac activation in WT and Gsn-cells. We conclude that the ability of gelsolin to remodel actin filaments is important for collagen-induced calcium entry; calcium in turn is required for rac activation, which subsequently enhances collagen binding to unoccupied α2β1 integrins.
How Well Does The Parkland Formula Estimate Actual Fluid Resuscitation Volumes?
Authors: Cartotto Robert C. , Innes Marilyn , Musgrave Melinda A. , Gomez Manuel , Cooper Andrew B.
Published: November 2003

We had anecdotally observed that fluid resuscitation volumes often exceed those estimated by the Parkland Formula in adults with isolated cutaneous burns. The purpose of this study was to compare estimated and actual fluid resuscitation volumes using the Parkland Formula. We performed a retrospective study of fluid resuscitation in patients with burns ≥ 15% TBSA. Patients with inhalation injury, high voltage electrical injury, delayed resuscitation, or associated trauma were excluded. We studied 31 patients (mean age 51 ± 20 years, mean TBSA burn 27 ± 10%). The 24 hour resuscitation volume of 13 354 ± 7386 ml (6.7 ± 2.8 ml/kg/%TBSA) was significantly greater than predicted (P = 0.001) and exceeded estimated volume in 84% of the patients. The mean urine output in the first 24 hrs was 1.2 ± 0.6 ml/kg/hr. After the first 8 hours of resuscitation, the infusion rate decreased by 34% in 16 patients (DCR group), while in 15 patients the rate increased by 47% (INCR group). Both the DCR and INCR groups received significantly more fluid than predicted, (5.6 ± 2.1 ml/kg/%TBSA and 7.7 ± 3.1 ml/kg/%TBSA respectively). The INCR patients had significantly larger full thickness burns (14 ± 11% vs 3 ± 6%, P < 0.001). Our findings reveal that despite its effectiveness, the Parkland Formula underestimated the volume requirements in most adults with isolated cutaneous burns, and especially in those with large full thickness burns.
Thermal Burn Fatalities in the Workplace, United States, 1992 to 1999
Authors: Quinney Brent , McGwin Gerald , Cross James M. , Valent Francesca , Taylor Allison J. , Rue Loring W.
Published: November 2003

The purpose of this study was to present the epidemiology of thermal burn fatalities in the workplace in the United States between 1992 and 1999. Data on fatal thermal burn injuries in the United States between 1992 through 1999 were obtained from the Bureau of Labor Statistics Census of Fatal Occupational Injuries. Between 1992 and 1999, 1,189 fatal thermal burns occurred in the workplace (0.11 deaths/100,000 workers per year). Mortality increased with age, with those over 65 years of age having the greatest rate of death (0.20/100,000). Workers in the mining industry and transportation and public utilities had the highest rates of fatal thermal burns. Occupational categories with the highest rates included “extractive occupations” (eg, miners, explosives workers) and “transportation and material movers” (eg, truck drivers). The specific occupations with the highest rates were airplane pilots and navigators, furnace, kiln, and oven operators, and firefighters. Most decedents were operating vehicles or involved in “other transportation operations” at the time of the incident. The majority of injurious incidents occurred on “industrial premises” or the “street and highway.” Efforts to prevent fatal occupational thermal burn injuries should focus on older workers and those in occupations with frequent exposure to potential sources of thermal injury. Further study of nonfatal thermal burns in the workplace is needed because patterns of fatal burn injury may not reflect patterns of occupational burn injury overall.
Thermoregulation in Burn Patients During Exercise
Authors: Austin K. G. , Hansbrough J. F. , Dore C. , Noordenbos J. , Buono M. J.
Published: November 2003

The purpose of this study was to assess the ability of patients with burns on 30 to 40% and 60% or greater of their BSA to thermoregulate their core temperature during exercise in the heat. Two groups (n = 3 in each) of subjects with healed third-degree burns (34.0 ± 1.4% and 77.7 ± 12.4%, respectively) and a group of unburned subjects (n = 2) exercised for 1 hour on a cycle ergometer at 75 Watts in an environmental chamber set at 35°C and 60% relative humidity. Subjects were monitored for rectal and skin temperatures, heart rate, whole body sweat rate, skin blood flow, and active sweat gland density (number per cm2) in unburned, burned, and harvested skin. The results demonstrated that patients with burns on 60% or greater BSA did not show an intolerance to moderate exercise in the heat, as evidenced by only a moderate rise in rectal temperature and heart rate. Furthermore, the responses were similar to those of the unburned subjects.
Chronic Nicotine Treatment Enhances Focal Ischemic Brain Injury and Depletes Free Pool of Brain Microvascular Tissue Plasminogen Activator in Rats
Authors: Wang Liang , Kittaka Mamoru , Sun Ning , Schreiber Steven S. , Zlokovic Berislav V.
Published: November 2003

Effects of nicotine treatment (4.5 mg/kg of nicotine-free base/day administered s.c. by osmotic minipumps for 14 days) on focal ischemic stroke and expression of tissue plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) in cerebral microvessels were studied in rats in vivo using a reversible (1 h) middle cerebral artery occlusion model. Plasma levels of nicotine and its major metabolite cotinine after 14 days of treatment were 88 and 364 ng/ml, respectively. Nicotine treatment resulted in 35–40% ( p <0.001) decrease in the blood flow in the periphery of the ischemic core during reperfusion, an increase in the neurologic score of 2.6-fold ( p <0.01), and 36% ( p <0.05) and 121% ( p <0.01) increases in the injury and edema volume in the pallium, respectively. A free pool of brain microvascular t-PA antigen was completely depleted by nicotine, while the expression of the PAI-1 antigen and/or PAI-1-t-PA complexes remained unchanged. The relative abundance of cerebromicrovascular t-PA mRNA transcript versus β-actin mRNA transcript did not change with nicotine. It is concluded that chronic nicotine treatment impairs the restoration of blood flow, worsens the neurologic outcome, and enhances brain injury following an ischemic insult. These nicotine effects are associated with depletion of brain microvascular t-PA antigen.
Expression of Zinc Finger Immediate Early Genes in Rat Brain After Permanent Middle Cerebral Artery Occlusion
Authors: Honkaniemi Jari , States Bradley A. , Weinstein Philip R. , Espinoza Jose , Sharp Frank R.
Published: November 2003

The prolonged expression of the leucine zipper fos/jun immediate early genes (IEG) has been correlated with neuronal death after cerebral ischemia. In this study, the expression of six zinc finger IEG was examined using in situ hybridization in adult rats after middle cerebral artery occlusion (MCAO) with the suture model. NGFI-A, NGFI-B, NGFI-C, egr-2, egr-3, and Nurr1 mRNA were all induced throughout the ipsilateral cortex at 1 hour to 12 hours after MCAO. The cortical induction for most of the genes was greatest in the anterior cingulate and the anterior cerebral artery (ACA) and middle cerebral artery (MCA) transition zone. All of the zinc finger IEG were induced at 1 hour in all regions of hippocampus. NGFI-A and NGFI-B were induced in ipsilateral thalamus. Within areas of infarction, the basal IEG mRNA expression, and expression of the housekeeping gene cyclophilin A mRNA, decreased below control levels by 12 hours after the ischemia. Immediate early gene expression outside areas of infarction returned to control levels in most brain regions by 24 hours except for egr-3, which continued to be induced in the MCA/ACA transition zone for 24 hours, and NGFI-A, which continued to be expressed in specific regions of the thalamus for 72 hours. The induction of these IEG in the cortex is likely caused by ischemia-induced cortical spreading depression, with the hippocampal and thalamic IEG induction being caused by activation of efferent cortical pathways to these regions. The prominent induction of NGFI-B, NGFI-C, egr-2, and egr-3 in the anterior cingulate cortex, the ACA/MCA transition zone, and medial striatum could reflect the ischemic regions around MCA infarcts. The prolonged NGFI-A expression observed in thalamus in this study, and in CA1 of hippocampus after global ischemia in the gerbil in a previous study, suggests that the prolonged NGFI-A expression could be the result of or the cause of the delayed cell death. Prolonged NGFI-A expression, like c-fos and c-jun, seems to provide a marker for slowly dying neurons.
Frequency-Dependent Changes of Regional Cerebral Blood Flow during Finger Movements: Functional MRI Compared to PET
Authors: Sadato Norihiro , Ibañez Vicente , Campbell Gregory , Deiber Marie-Pierre , Le Bihan Denis , Hallett Mark
Published: November 2003

To evaluate the effect of the repetition rate of a simple movement on the magnitude of neuronal recruitment in the primary sensorimotor cortex, we used a blood flow-sensitive, echo planar functional magnetic resonance imaging (fMRI) sequence in six normal volunteers. Three of the volunteers also had [15O]water positron emission tomography (PET) studies using the same paradigm. Previous PET studies had shown an increase in regional CBF (rCBF) with movement frequencies up to 2 Hz and then a plateau of regional cerebral blood flow (rCBF) at faster frequencies. To evaluate the extent of the activation, the correlation coefficient (cc) of the Fourier-transformed time-signal intensity change with the Fourier-transformed reference function was calculated pixel by pixel. The degree of activation was measured as the signal percent change of each region of interest with a cc > 0.5. The left primary sensorimotor cortex was constantly activated at 1, 1.5, 2, and 4 Hz, while there was only inconsistent activation at 0.25 and 0.5 Hz. Percent change in signal intensity linearly increased from 1 to 4 Hz. Area of activation increased up to 2 Hz and showed a tendency to decrease at higher frequencies. Individual analysis of PET data showed activation in the same location as that revealed by fMRI. The combination of progressively increasing signal intensity with an area that increases to 2 Hz and declines at faster frequencies explains the PET finding of plateau of rCBF at the faster frequencies. Functional magnetic resonance imaging shows similar results to PET, but is better able to dissociate area and magnitude of change.
Effect of Aging on Regulation of Brain Stem Circulation During Hypotension
Authors: Toyoda Kazunori , Fujii Kenichiro , Takata Yutaka , Ibayashi Setsuro , Fujikawa Megumi , Fujishima Masatoshi
Published: November 2003

This study was designed to determine age-related changes in autoregulatory responses of the brain stem circulation in vivo. In anesthetized adult (4 to 6 months, n = 8) and aged (24 to 26 months, n = 7) Sprague-Dawley rats, local CBF to the brain stem was determined with laser-Doppler flowmetry and diameters of the basilar artery and its branches were measured through an open cranial window during stepwise hemorrhagic hypotension. In aged rats, the lower limit of CBF auto-regulation shifted upward to 60 to 75 mm Hg from 30 to 45 mm Hg in adult rats. Dilator responses of the basilar artery (baseline diameter: 254 ± 15 μm), large branch (109 ± 23 μm), and small branch (44 ± 10 μm) to hypotension were much smaller in aged rats than in adult rats. The maximum change in diameter of the basilar artery during profound hypotension was significantly smaller in aged rats (11 ± 8%) than that in adult ones (23 ± 12%, P < 0.05); that of the large branch was 12 ± 8% versus 33 ± 17% ( P < 0.005); and that of the small branch was 17 ± 7% versus 40 ± 13% ( P < 0.0005), suggesting greater attenuation of the responses in the smaller vessels. Thus, this study provides direct evidence that aging diminishes the compensatory dilatation of brain stem arterioles and arteries during hypotension and modifies the autoregulatory plateau of CBF, which seems to increase the risk of the brain stem ischemia during hypotensive conditions.
Measurement of Striatal D2 Dopamine Receptor Density and Affinity with [11C]-Raclopride in Vivo: A Test-Retest Analysis
Authors: Hietala Jarmo , Någren Kjell , Lehikoinen Pertti , Ruotsalainen Ulla , Syvälahti JErkka
Published: November 2003

Subacute and long-term stability of measurements of D2 dopamine receptor density (Bmax), affinity (Kd) was studied with positron emission tomography in eight healthy male volunteers. [11C]-Raclopride and the transient equilibrium method were used to measure D2 receptor characteristics. The interval between measurements (scan pairs) was 3 to 7 weeks (subacute) for four subjects and 6 to II months (long-term) for four subjects. A test-retest analysis of quantitative measurements of D2 receptor Bmax and Kd was compared with that done on binding potential (BP, Bmax/Kd) measures. In addition, the effect of error in defining the transient equilibrium time (tmax) in the parameter estimation procedure was explored with simulations. The subacute test-retest indicates good reproducibility of D2 receptor density, affinity, and BP ratio measurements with intraclass correlation coefficients of 0.90, 0.96, and 0.86, respectively. The variability of the measurements after 6 to 11 months was slightly higher than that seen in a subacute testing for Kd and more clearly so for binding potential and Bmax. The absolute variability in Bmax (14.5%) measurements was consistently higher than that of Kd (8.4%) or BP (7.9%) both in subacute and long-term measurements. Simulations indicated that the Bmax and Kd estimation procedure is more sensitive to error in the tmax than that for the BP. The results indicate a good overall stability of the equilibrium method with [11C]raclopride for measuring dopamine D2 receptor binding characteristics in the striatum. The BP approach is more stable than Kd and especially Bmax measurements. Error in defining the tmax in particular in the low specific radioactivity scan may be one source of greater variability in Bmax versus BP. However, a higher intraindividual variability in measurements of the D2 receptor Bmax also may include a component of continuous regulation of this parameter over time. These methodologic aspects should be considered in the design and interpretation of longitudinal studies on D2 dopamine receptor characteristics with [11C]-raclopride.
Activated Microvessels Express Vascular Endothelial Growth Factor and Integrin αvβ3 During Focal Cerebral Ischemia
Authors: Abumiya Takeo , Lucero Jacinta , Heo Ji Hoe , Tagaya Masafumi , Koziol James A. , Copeland Brian R. , del Zoppo Gregory J.
Published: November 2003

Both vascular endothelial growth factor (VEGF) and integrin αvβ3 play roles in angiogenesis. In noncerebral vascular systems, VEGF can induce endothelial integrin αvβ3 expression. However, it is unknown whether VEGF, like integrin αvβ3, appears in the initial response of microvessels to focal brain ischemia. Their coordinate expression in microvessels of the basal ganglia after middle cerebral artery occlusion (MCAO) in the nonhuman primate model was examined quantitatively. Cells incorporating deoxyuridine triphosphate (dUTP+) by the polymerase I reaction at 1 hour (n = 3), 2 hours (n = 3), and 7 days (n = 4) after MCAO defined the ischemic core (Ic) and peripheral regions. Both VEGF and integrin αvβ3 were expressed by activated noncapillary (7.5- to 30.0-μm diameter) microvessels in the Ic region at 1 and 2 hours after MCAO. At 7 days after MCAO, the number of VEGF+, integrin αvβ3+, or proliferating cell nuclear antigen-positive microvessels had decreased within the Ic region. The expressions of VEGF, integrin αvβ3, and proliferating cell nuclear antigen were highly correlated on the same microvessels using hierarchical log-linear statistical models. Also, VEGF and subunit αv messenger ribonucleic acids were coexpressed on selected microvessels. Here, noncapillary microvessels are activated specifically early during a focal cerebral ischemic insult and rapidly express VEGF and integrin αvβ3 together.
Multiresolution Analysis of Emission Tomography Images in the Wavelet Domain
Authors: Turkheimer Federico E. , Brett Matthew , Visvikis Dimitris , Cunningham Vincent J.
Published: November 2003

This article develops a theoretical framework for the use of the wavelet transform in the estimation of emission tomography images. The solution of the problem of estimation addresses the equivalent problems of optimal filtering, maximum compression, and statistical testing. In particular, new theory and algorithms are presented that allow current wavelet methodology to deal with the two main characteristics of nuclear medicine images: low signal-to-noise ratios and correlated noise. The technique is applied to synthetic images, phantom studies, and clinical images. Results show the ability of wavelets to model images and to estimate the signal generated by cameras of different resolutions in a wide variety of noise conditions. Moreover, the same methodology can be used for the multiscale analysis of statistical maps. The relationship of the wavelet approach to current hypothesis-testing methods is shown with an example and discussed. The wavelet transform is shown to be a valuable tool for the numerical treatment of images in nuclear medicine. It is envisaged that the methods described here may be a starting point for further developments in image reconstruction and image processing.
An Absolute Measurement of Brain Water Content Using Magnetic Resonance Imaging in Two Focal Cerebral Ischemic Rat Models
Authors: Lin Weili , Venkatesan Ramesh , Gurleyik Kilichan , He Yong Y. , Powers William J. , Hsu Chung Y.
Published: November 2003

Magnetic resonance imaging (MRI) was utilized to obtain absolute estimates of regional brain water content (W), and results were compared with those obtained with conventional wet/dry measurements. In total, 31 male Long-Evans rats were studied and divided into two groups based on the surgical procedures used to induce cerebral focal ischemia: suture (n = 18) and three-vessel ligation (TVL; n = 13) groups. Both relative spin density and T1 were extracted from the acquired MR images. After correcting for radiofrequency field inhomogeneities, T2* signal decay, and temperature effects, in vivo regional brain water content, in absolute terms, was obtained by normalizing the measured relative brain spin density of animals to that of a water phantom. A highly linear relationship between MR-estimated brain water content based on the normalized spin density and wet/dry measurements was obtained with slopes of 0.989 and 0.986 for the suture ( r = 0.79) and TVL ( r = 0.83) groups, respectively. Except for the normal subcortex of the TVL group ( P < 0.02) and the normal hemisphere of the suture group ( P < 0.003), no significant differences were observed between MR-estimated and wet/dry measurements of brain water content. In addition, a highly linear relationship between MR-measured R1 (= 1/T1) and 1/W of wet/dry measurements was obtained. However, slopes of the linear regression lines in the two groups were significantly different ( P < 0.02), indicating that different R1 values were associated with the same water content depending on the model. These results show that an absolute measurement of in vivo regional brain water content can be obtained with MRI and potentially serves as a noninvasive means to monitor different therapeutic interventions for the management of brain edema subsequent to stroke and head trauma.
Acute Decrease in Cerebral Nitric Oxide Levels after Subarachnoid Hemorrhage
Authors: Sehba Fatima A. , Schwartz Amit Y. , Chereshnev Igor , Bederson Joshua B.
Published: November 2003

Disturbances in the nitric oxide (NO) vasodilatory pathway have been implicated in acute vasoconstriction and ischemia after subarachnoid hemorrhage (SAH). The authors hypothesize that blood released during SAH leads to vasoconstriction by scavenging NO and limiting its availability. This was tested by measuring the major NO metabolites nitrite and nitrate in five different brain regions before and after experimental SAH. The basal NO metabolites levels were as follows (mean ± SD, μmol/mg wet weight): brain stem, 0.14 ± 0.07; cerebellum, 0.12 ± 0.08; ventral convexity cortex, 0.22 ± 0.15; dorsal convexity cortex, 0.16 ± 0.11; and hippocampus, 0.26 ± 0.17. In sham-operated animals, no effect of the nitric oxide synthase (NOS) inhibitor lG-nitro-L-arginine-methyl-ester (30 mg/kg) was found on NO metabolites 40 minutes after administration, but a significant decrease was seen after 120 minutes. The NO metabolites decreased significantly 10 minutes after SAH in all brain regions except for hippocampus, and recovered to control levels in cerebellum at 60 minutes and in brain stem and dorsal cerebral cortex 180 minutes after SAH, while remaining low in ventral convexity cortex. Nitrite recovered completely in all brain regions at 180 minutes after SAH, whereas nitrate remained decreased in brain stem and ventral convexity cortex. Our results indicate that SAH causes acute decreases in cerebral NO levels by a mechanism other than NOS inhibition and provide further support for the hypothesis that alterations in the NO vasodilatory pathway contribute directly to the ischemic insult after SAH.
Astrocyte-Specific Expression of Aquaporin-9 in Mouse Brain is Increased after Transient Focal Cerebral Ischemia
Authors: Badaut Jérôme , Hirt Lorenz , Granziera Cristina , Bogousslavsky Julien , Magistretti Pierre J. , Regli Luca
Published: November 2003

Aquaporin-9 (AQP9) is a new member of the aquaporin family of water-selective channels mainly expressed in liver and testis, presenting the characteristic of also being permeable to various solutes, particularly lactate. Recent data have shown the presence of AQP9 on tanycytes in the rat brain. In the current study, the authors show the expression of AQP9 in astrocytes in the mouse brain and changes in its expression after cerebral ischemia. Indeed, in control mouse, the AQP9 immunolabeling is present on astrocytic processes bordering the subarachnoid space and ventricles. The labeling also is observed on astrocytes in the white matter, hippocampus, hypothalamus, and lateral septum. After focal transient ischemia, an increase of the immunolabeling is detected on astrocytes in periinfarct areas. This AQP9 distribution study in mouse brain suggests a role of AQP9 in water homeostasis in the central nervous system. Furthermore, the overexpression of AQP9 on astrocytes surrounding an ischemic lesion suggests that AQP9 may also play a role in the regulation of postischemia edema and, in view of its permeability to monocarboxylates, in the clearance of lactate from the ischemic focus.
Metabotropic Glutamate Receptor Subtypes as Targets for Neuroprotective Drugs
Authors: Bruno Valeria , Battaglia Giuseppe , Copani Agata , D'Onofrio Mara , Di Iorio P. , De Blasi Antonio , Melchiorri Daniela , Flor Peter J. , Nicoletti Ferdinando
Published: November 2003

Metabotropic glutamate (mGlu) receptors have been considered as potential targets for neuroprotective drugs, but the lack of specific drugs has limited the development of neuroprotective strategies in experimental models of acute or chronic central nervous system (CNS) disorders. The advent of potent and centrally available subtype-selective ligands has overcome this limitation, leading to an extensive investigation of the role of mGlu receptor subtypes in neurodegeneration during the last 2 years. Examples of these drugs are the noncompetitive mGlu1 receptor antagonists, CPCCOEt and BAY-36-7620; the noncompetitive mGlu5 receptor antagonists, 2-methyl-6-(phenylethynyl)pyridine, SIB-1893, and SIB-1757; and the potent mGlu2/3 receptor agonists, LY354740 and LY379268. Pharmacologic blockade of mGlu1 or mGlu5 receptors or pharmacologic activation of mGlu2/3 or mGlu4/7/8 receptors produces neuroprotection in a variety of in vitro or in vivo models. MGlu1 receptor antagonists are promising drugs for the treatment of brain ischemia or for the prophylaxis of neuronal damage induced by synaptic hyperactivity. MGlu5 receptor antagonists may limit neuronal damage induced by a hyperactivity of N-methyl-d-aspartate (NMDA) receptors, because mGlu5 and NMDA receptors are physically and functionally connected in neuronal membranes. A series of observations suggest a potential application of mGlu5 receptor antagonists in chronic neurodegenerative disorders, such as amyotrophic lateral sclerosis and Alzheimer disease. MGlu2/3 receptor agonists inhibit glutamate release, but also promote the synthesis and release of neurotrophic factors in astrocytes. These drugs may therefore have a broad application as neuroprotective agents in a variety of CNS disorders. Finally, mGlu4/7/8 receptor agonists potently inhibit glutamate release and have a potential application in seizure disorders. The advantage of all these drugs with respect to NMDA or AMPA receptor agonists derives from the evidence that mGlu receptors do not “mediate,” but rather “modulate” excitatory synaptic transmission. Therefore, it can be expected that mGlu receptor ligands are devoid of the undesirable effects resulting from the inhibition of excitatory synaptic transmission, such as sedation or an impairment of learning and memory.
An Energy Budget for Signaling in the Grey Matter of the Brain
Authors: Attwell David , Laughlin Simon B.
Published: November 2003

Anatomic and physiologic data are used to analyze the energy expenditure on different components of excitatory signaling in the grey matter of rodent brain. Action potentials and postsynaptic effects of glutamate are predicted to consume much of the energy (47% and 34%, respectively), with the resting potential consuming a smaller amount (13%), and glutamate recycling using only 3%. Energy usage depends strongly on action potential rate—an increase in activity of 1 action potential/cortical neuron/s will raise oxygen consumption by 145 mL/100 g grey matter/h. The energy expended on signaling is a large fraction of the total energy used by the brain; this favors the use of energy efficient neural codes and wiring patterns. Our estimates of energy usage predict the use of distributed codes, with ≤15% of neurons simultaneously active, to reduce energy consumption and allow greater computing power from a fixed number of neurons. Functional magnetic resonance imaging signals are likely to be dominated by changes in energy usage associated with synaptic currents and action potential propagation.
Outcomes Related to Burn-Related Child Abuse: A Case Series
Authors: Ruth G. D. , Smith S. , Bronson M. , Davis A. T. , Wilcox R. M.
Published: November 2003

Nationally, approximately 10% of child abuse cases involve burning, and up to 20% of pediatric burn admissions involve abuse or neglect. Historically, these cases have been more difficult to prosecute than nonburn cases for multiple reasons. Between 1995 and 1999, there were 285 pediatric (under 18) patients admitted to the Spectrum Health Regional Burn Center. Of these cases, 18 of the alleged perpetrators were legally investigated for suspicion of child abuse, and 7 received punitive sentences. We found that men tended to be prosecuted and convicted more often than women and that cases involving multiple instances of injury tended to be prosecuted more frequently. Similarly, we found that cases involving more severe injuries tended to be prosecuted more successfully. There are many psychological and social factors involved in handling burn abuse cases. However, by successful prosecution of these crimes, victims tend to fare better both socially and psychologically.
Analysis of Gene Expression Patterns in Human Postburn Hypertrophic Scars
Authors: Paddock Heather N. , Schultz Gregory S. , Baker Henry V. , Varela Juan Carlos , Beierle Elizabeth A. , Moldawer Lyle L. , Mozingo David W.
Published: November 2003

Hypertrophic scars cause cosmetic disfigurement and limited mobility in burn patients. To better understand the molecular pathophysiology of hypertrophic scar formation, microarray analyses were performed on normal skin and hypertrophic scars from four burn patients. Microarray analyses were determined in an effort to identify genes whose expression discriminated between normal skin and mature, hypertrophic scars. Surgical biopsies were obtained from two pediatric and two adult patients 6 to 15 months after burn injury. Total RNA was isolated from the samples and subjected to microarray analysis using the Affymetrix U95Av2 GeneChip®. Results from this analysis revealed 31 probe sets representing genes that were consistently up-regulated at least two-fold in hypertrophic scar specimens from all four patients and four probe sets that were down-regulated. The significance analysis of microarrays algorithm also identified 35 probe sets whose increased expression resulted in the hierarchal clustering of the hypertrophic scar and normal tissue, seven of which were identical to the six genes identified by paired analyses. These six genes all displayed elevated levels of expression in the scar tissue. Proteins encoded by the genes identified included germline oligometric matrix protein, matrix metalloproteinase-16, collagen type 1α, pleiotrophin, and thrombospondin-4. Although the results presented here suggest that there may be unique patterns of gene expression in hypertrophic scars that may be important in the evaluation and treatment of hypertrophic scarring, the results must be confirmed with larger datasets.
Use of genetic algorithm to design optimal neural network structure
Authors: Öztürk Nursel
Published: November 2003

In this research, neural network (NN) and genetic algorithm (GA) are used together to design optimal NN structure. The proposed approach combines the characteristics of GA and NN to reduce the computational complexity of artificial intelligence applications in design and manufacturing. Genetic input selection approach is introduced to obtain optimal NN topology. Experimental results are given to evaluate the performance of the proposed system.
Testing market orientation of bank managers in the emerging economy of Brunei
Authors: Aziz Anwar Syed , Sadiq Sohail M.
Published: November 2003

A formidable body of literature has been built up in recent decades suggesting that market orientation helps firms attain their strategic objectives in a dynamic environment. The present study tests market orientation of bank managers operating in Brunei, a small South‐East Asian country endowed with buoyant oil and gas reserves, seeking to carve out a pivotal role for itself in the banking and financial services sector of the region. Four key areas, referred to as variables, in the decision making process have been identified and used to analyse the form of market orientation adopted by bank managers in Brunei. These variables pertain to focus on customers, competition, environmental scanning, and implementation of strategic decisions. Results suggest that the managers sampled for this study are fragmented in terms of market orientation used.
Technophobia, gender influences and consumer decision‐making for technology‐related products
Authors: Gilbert David , Lee‐Kelley Liz , Barton Maya
Published: November 2003

Mobile Internet technology (MIT) is an extension of the Internet beyond the static terminal of the personal computer or television. It has been forecasted that by the end of 2005, there will be almost 500 million users of mobile m‐commerce, generating more than $200 billion in revenues. Contributes to the body of knowledge on how to approach the study of MIT products. Proposes that consumer perceptions of MIT products can lead to dichotomous decision making and argues that the challenge for marketers is to harness and fit this dichotomy to the MIT product continuum through an understanding of consumer psychological and attribution factors. The overall findings indicate that technology anxiety correlates with demographic variables such as age, gender and academic qualifications. Therefore, the implications of the study are that technology product engineering and marketing should recognise the importance of: study of the psychosocial needs of technology products, human factors in engineering design which need to fit these needs; and developing product designs facilitating consumers' psychosocial needs.
The Rise of Supermarkets in Africa: Implications for Agrifood Systems and the Rural Poor
Authors: Weatherspoon Dave D. , Reardon Thomas
Published: November 2003

The rise of supermarkets in Africa since the mid‐1990s is transforming the food retail sector. Supermarkets have spread fast in Southern and Eastern Africa, already proliferating beyond middle‐class big‐city markets into smaller towns and poorer areas. Supplying supermarkets presents both potentially large opportunities and big challenges for producers. Supermarkets' procurement systems involve purchase consolidation, a shift to specialised wholesalers, and tough quality and safety standards. To meet these requirements, producers have to make investments and adopt new practices. This is hardest for small producers, who risk exclusion from dynamic urban markets increasingly dominated by supermarkets. There is thus an urgent need for development programmes and policies to assist them in adopting the new practices that these procurement systems demand.
A Cost‐Effectiveness Analysis of the Grameen Bank of Bangladesh
Authors: Schreiner Mark
Published: November 2003

Reports of the success of the Grameen Bank of Bangladesh have led to rapid growth in funding for microfinance. But has the Grameen Bank been cost‐effective? This article compares output with subsidy for the bank in a present‐value framework. For the timeframe 1983–97, subsidy per person‐year of membership in Grameen was about $20, and subsidy per dollar‐year borrowed was about $0.22. Although the article does not measure consumer surplus for Grameen users, the evidence in the literature suggests that surplus probably exceeds subsidy. The Grameen Bank — if not necessarily other microlenders — was probably a worthwhile social investment.
Elements of Resilience After the World Trade Center Disaster: Reconstituting New York City's Emergency Operations Centre
Authors: Kendra James M. , Wachtendorf Tricia
Published: November 2003

In this paper we examine the reconstitution of the Emergency Operations Centre (EOC) after its destruction in the World Trade Center attack, using that event to highlight several features of resilience. The paper summarises basic EOC functions, and then presents conceptions of resilience as understood from several disciplinary perspectives, noting that work in these fields has sought to understand how a natural or social system that experiences disturbance sustains its functional processes. We observe that, although the physical EOC facility was destroyed, the organisation that had been established to manage crises in New York City continued, enabling a response that drew on the resources of New York City and neighbouring communities, states and the federal government. Availability of resources — which substituted for redundancy of personnel, equipment and space — pre‐existing relationships that eased communication challenges as the emergency developed and the continuation of organisational patterns of response integration and role assignments were among the factors that contributed to resilience following the attack.
On a responsive replenishment system: a fuzzy logic approach
Authors: Leung R.W.K. , Lau H.C.W. , Kwong C.K.
Published: November 2003

In today's competitive business environment, it is important that customers are able to obtain their preferred items in the shops they visit, particularly for convenience store chains such as 7–Eleven where popular items are expected to be readily available on the shelves of the stores for buyers. To minimize the cost of running such store chains, it is essential that stocks be kept to a minimum and at the same time large varieties of popular items are available for customers. In this respect, the replenishment system needs to be able to cope with the taxing demands of minimal inventory but at the same time keeping large varieties of needed items. This paper proposes a replenishment system which is able to respond to the fluctuating demands of customers and provide a timely supply of needed items in a cost–effective way. The proposed system embraces the principle of fuzzy logic which is able to deal with uncertainties by virtue of its fuzzy rules reasoning mechanism, thereby leveraging the responsiveness of the entire replenishment system for the chain stores. To validate the feasibility of the approach, a case study has been conducted in an emulated environment with promising results.
One or Several Betrayals? or, When is Betrayal Treason? Genet, Arlt and the Argentine Liberal Project
Authors: Bollig Ben
Published: November 2003

Betrayal is one of the key narrative tropes in the fiction of the Argentine writer Roberto Arlt. The psychological and existential implications of the betrayals found in novels such as El juguete rabioso (1926) and El amor brujo (1933) have attracted much critical comment, as have the links between the betrayals found in Arlt's fiction and the work of Jean Genet. Arlt's oeuvre has been read in relation to the turbulent political context of 1920s and 30s Argentina, in particular the failure of the Liberal Project of economic development through immigration that was introduced after the fall of the dictator Juan Manuel de Rosas in 1852, the economic collapse of 1929 and the ensuing military coup of 1930. Critics have suggested that betrayal in Arlt represents an attack on bourgeois hypocrisy, a middle‐class attempt at transcending one's environment, or a reversal of dominant social values. This paper however intends to deepen the understanding of betrayal in Arlt's fiction by examining it as a political gesture, a quality overlooked by many studies. A reading of the political nature of betrayal in Genet's work and an engagement with Bersani's queer reading of Funeral Rites alongside Said's analysis of Genet as an anti‐identarian revolutionary, allows the reader of Arlt to reassess the political gesture contained in betrayal, and to move towards a reading of the development in Arlt's fiction either side of the military takeover of 1930, moving from his critique of the rising petit‐bourgeois classes in El juguete rabioso (1926) to a clear realisation and encouragement of class consciousness in the short stories of El criador de gorilas (1936).
Sporangia containing Scylaspora from the Lower Devonian of the Welsh Borderland
Authors: Wellmann Charles H.
Published: November 2003

ABSTRACT. Bulk maceration of Early Devonian (Lochkovian) deposits from the Welsh Borderland has yielded eight specimens of a new type of sporangium characterized by its elongate shape and distinctive spores. The specimens have been examined using scanning electron, transmission electron and light microscopy. The elongate sporangia occur isolated and are fragmented to varying degrees. They contain trilete spores that possess a proximal surface with shallow murornate ornament and a distal surface that is laevigate. The spores belong to the dispersed spore genus Scylaspora, and this is the first report of such spores in situ. Ultrastructural studies demonstrate that the spore walls are bilayered with a lamellate inner layer overlain by an essentially homogeneous outer layer. There is little or no associated extra‐exosporal material. To date this is the earliest reported example of lamellate wall ultrastructure in trilete spores. Models of spore wall development are suggested in the light of evidence provided by spore wall ultrastructure. Detailed comparisons of the characters preserved in the fossils (morphological, anatomical and ultrastructural), with those in other fossil and extant plants, currently shed little light on the phylogenetic relationships of these specimens, primarily due to the paucity of comparable data. It is proposed that the plant is probably of vascular status, but in the absence of evidence for vascular tissue, it must be classified as rhyniophytoid.
Bucaniid gastropods from the upper Ordovician of Baltica, with a discussion of the Bucaniinae
Authors: Ebbestad Jan Ove R.
Published: November 2003

ABSTRACT. Three species of bucaniid gastropods from the upper Ordovician of Norway and Sweden are revised: Euomphalopterus excavatus is redescribed as a species of Phragmolites with very wide umbilici and ornamentation similar to that of Offleya. Three out of five specimens from the original type series of Temnodiscus lindstroemi remain, representing two different species of two different genera. The original species name is restricted to a species of Phragmolites, whereas two specimens are considered conspecific with Megalomphala? carinata sp. nov., although the high carina, the flaring aperture and the laterally compressed whorls seen in this species are unusual for the genus. The gastropod subfamily Bucaniinae of the family Bucaniidae is here considered to comprise nine genera. Placement of Phragmolites in this family is supported by its deep slit, tangential aperture, transverse growth lines, spiral and collabral ornamentation and the presence of a longitudinal keel on the base of the whorl.
An early Bathonian Tethyan ammonite fauna from Argentina
Authors: Riccardi Alberto C. , Westermann Gerd E. G.
Published: November 2003

Evidence for the Lower Bathonian Substage in most of the Pacific area has been lacking or controversial because index ammonoids of the Tethyan Subrealm in southern Europe and North Africa were unknown. During the Bathonian, the East Pacific margin belonged to either the Boreal Realm or the East‐Pacific Subrealm of the Tethyan Realm, each with faunas distinctly different from the Eurafrican Tethyan faunas that form the basis for the chronostratigraphical standard. The first representatives of Morphoceras from South America, M. gulisanoi sp. nov., here described from a single locality in southern Mendoza Province, clearly document the Lower Bathonian Substage, probably the Zigzag Zone. Associated ammonoids are the perisphinctoidean Procerites cf. schloenbachi de Grossouvre and the oppeliid Oxycerites (O.) cf. aspidoides (Oppel), also typical Tethyan elements but less useful for dating.
Functional characterization and cold sensitivity of T1313A, a new mutation of the skeletal muscle sodium channel causing paramyotonia congenita in humans
Authors: Bouhours Magali , Sternberg Damien , Davoine Claire‐Sophie , Xavier Ferrer , Willer Jean Claude , Fontaine Bertrand , Tabti Nacira
Published: November 2003

Paramyotonia congenita (PC) is a dominantly inherited skeletal muscle disorder caused by missense mutations in the SCN4A gene encoding the pore‐forming α subunit (hSkM1) of the skeletal muscle Na+ channel. Muscle stiffness is the predominant clinical symptom. It is usually induced by exposure to cold and is aggravated by exercise. The most prevalent PC mutations occur at T1313 on DIII–DIV linker, and at R1448 on DIV–S4 of the α subunit. Only one substitution has been described at T1313 (T1313M), whereas four distinct amino‐acid substitutions were found at R1448 (R1448C/H/P/S). We report herein a novel mutation at position 1313 (T1313A) associated with a typical phenotype of PC. We stably expressed T1313A or wild‐type (hSkM1) channels in HEK293 cells, and performed a detailed study on mutant channel gating defects using the whole‐cell configuration of the patch‐clamp technique. T1313A mutation impaired Na+ channel fast inactivation: it slowed and reduced the voltage sensitivity of the kinetics, accelerated the recovery, and decreased the voltage‐dependence of the steady state. Slow inactivation was slightly enhanced by the T1313A mutation: the voltage dependence was shifted toward hyperpolarization and its steepness was reduced compared to wild‐type. Deactivation from the open state assessed by the tail current decay was only slowed at positive potentials. This may be an indirect consequence of disrupted fast inactivation. Deactivation from the inactivation state was hastened. The T1313A mutation did not modify the temperature sensitivity of the Na+ channel per se. However, gating kinetics of the mutant channels were further slowed with cooling, and reached levels that may represent the threshold for myotonia. In conclusion, our results confirm the role of T1313 residue in Na+ channel fast inactivation, and unveil subtle changes in other gating processes that may influence the clinical phenotype.
Tropical Soils and Food Security: The Next 50 Years
Authors: Stocking M. A.
Published: November 2003

An appreciation of the dynamism of the links between soil resources and society provides a platform for examining food security over the next 50 years. Interventions to reverse declining trends in food security must recognize the variable resilience and sensitivity of major tropical soil types. In most agro-ecosystems, declining crop yield is exponentially related to loss of soil quality. For the majority smallholder (subsistence) farmers, investments to reverse degradation are primarily driven by private benefit, socially or financially. “Tragedy of the commons” scenarios can be averted by pragmatic local solutions that help farmers to help themselves.
The amount of sleep obtained by locomotive engineers: effects of break duration and time of break onset
Authors: Roach G D , Reid K J , Dawson D
Published: November 2003

Aims:To determine the effects of break duration and time of break onset on the amount of sleep that locomotive engineers obtain between consecutive work periods.

Methods:A total of 253 locomotive engineers (249 male, 4 female, mean age 39.7 years) participated. Data were collected at 14 rail depots, where participants drove electric or diesel locomotives; worked with another engineer or drove alone; carried passengers, freight, or coal; and operated in rural or urban areas. Participants completed sleep diaries and work diaries for a two week period while working their normal roster patterns.

Results:For breaks that began at similar times of day, total sleep time (TST) increased with break duration. For breaks of similar duration, TST was greater for those that occurred during the night-time than for those that occurred during the daytime. An average of 3.1–7.9 hours sleep was obtained in 12 hour breaks (minimum break requirement in the Australian rail industry), depending on when the break began.

Conclusions:The duration and timing of breaks are both important factors in determining the amount of sleep that locomotive engineers obtain between consecutive work periods. Consequently, minimum length break requirements that do not include a time of day component may not provide locomotive engineers with the opportunity to obtain a sufficient amount of sleep prior to resuming work.
INTERVAL METHODS IN KNOWLEDGE REPRESENTATION
Authors: KREINOVICH VLADIK
Published: November 2003

This section is maintained by Vladik Kreinovich. Please send your abstracts (or copies of papers that you want to see reviewed here) to vladik@cs.utep.edu, or by regular mail to: