bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intracranial Extradural Pressure Monitoring after Direct Operation on Ruptured Cerebral Aneurysms
Authors: Takeuchi Shigekazu , Koike Tetsuo , Sasaki Osamu , Kamada Ken-ichi , Tanaka Ryuichi , Arai Hiroyuki 
Published: May 2010

ABSTRACT
Intracranial extradural pressure (ICP) was monitored by using a miniaturized transducer for an average period of 8 days after direct operation in 55 patients with ruptured cerebral aneurysms. Acute stage operation and drainage of cerebrospinal fluid were simultaneously performed in most of the patients. In many grade I patients with satisfactory cisternal drainage, ICP was monotonously stable, with faint pressure waves. When the drained fluid volume decreased or drainage was removed, however, ICP was elevated moderately, with associated pressure waves present. There were no A-waves observed in any of the patients. Decreases of mean ICP and disappearance of pressure waves were found 2 to 3 hours after infusion of 200 or 300 ml of 10% glycerol or 20% mannitol in patients without drainage or with an inadequate drain, but were not found in patients with a good drain. In a patient showing diffuse severe vasospasm, a rapid elevation of ICP caused by marked brain edema was observed. In patients with residual aneurysms or incompletely clipped aneurysms, ICP increased immediately after rupture of these aneurysms. The daily mean ICP was higher in patients with a clinically poor condition and/or severe subarachnoid hemorrhage on admission than in those with a good condition and/or mild subarachnoid hemorrhage, in spite of a functional drain. There was a poor outcome in about half of the patients showing maximum daily mean ICP &lt;30 mm Hg or frequent B-waves. No complications caused by ICP monitoring were found. Because of the relatively less invasive methodology lack of complications, good insight into intracranial conditions and prediction of prognosis, intracranial extradural pressure monitoring was considered to be useful in the management of patients following aneurysmal surgery.
Pseudotumor of the Sellar and Parasellar Areas
Authors: Gartman John J. , Powers Stephen K. , Fortune Michael 
Published: May 2010

ABSTRACT
A 54-year-old woman who had symptoms of intermittent meningeal irritation and hypopituitarism was found to have a sellar mass histologically consistent with pseudotumor. The lesion appears to have originated in the sphenoid sinus and subsequently to have spread intracranially, causing bony erosion. To our knowledge, this is the first description of pseudotumor occurring as a sellar mass.
Magnetic Resonance Imaging in Cases of Spinal Dural Arteriovenous Malformation
Authors: Isu Toyohiko , Iwasaki Yoshinobu , Akino Minoru , Koyanagi Izumi , Abe Hiroshi 
Published: May 2010

ABSTRACT
Two patients with spinal dural arteriovenous malformations associated with intramedullary changes confirmed by the T2-weighted magnetic resonance imaging (MRI) scans are reported. The characteristics of the MRI findings for these 2 patients were as follows. 1) In the T2-weighted spin-echo image, intramedullary changes observed by MRI were visualized as a high signal intensity area at the level where delay in venous circulation of the spinal cord was revealed by the angiography of the spinal cord. 2) After the obliteration of the arteriovenous shunt by surgical management, intramedullary changes remarkably decreased and disappeared with the disappearance of swelling of the spinal cord observed preoperatively. After that, the atrophy of the spinal cord was shown. 3) The level, extent, and severity of intramedullary changes remarkably decided by the condition of the level where the radiculospinal vein, as the flowing vein, refluxes into the coronal venous plexus and venous flow occurs through the radiculospinal vein into the epidural veins. We suspect that intramedullary changes shown by the T2-weighted MRI scan chiefly represent edema of the spinal cord, caused by an increase in venous pressure due to venous congestion of the spinal cord. MRI is a very useful diagnostic aid to detect intramedullary changes associated with a spinal dural arteriovenous malformation and to evaluate therapeutic results after surgery.
Colloid Cyst of the Fourth Ventricle: Diagnostic Problems and Pathogenic Considerations
Authors: Jan Michel , Zeze Vincent Ba , Velut Stéphane 
Published: May 2010

ABSTRACT
The authors report the case history of a patient with a colloid cyst of the 4th ventricle. The clinical history of slow intracranial hypertension, homogeneous hyperdensity with contrast enhancement on computed tomographic, scan, and the gelatinous aspect of the cyst at surgery are characteristic of colloid cysts. The diagnosis was made, however, only at the time of histological examination. A common neuroepithelial origin with 3rd ventricle cysts would be explained by similar embryological developments of the prosencephalic and the rhombencephalic roofs.
Pastoralism and the Non-Pastoral World in the Late Pre-Columbian History of the Southern Andes (1000-1535)
Authors: Nielsen Axel E. 
Published: May 2010

Abstract
Based on archaeological data, we discuss the various ways in which herding and herders articulated with other activities and actors in the South Andes during the last few centuries before the Spanish conquest of America. This relationship took different forms, including pastoral specialization and inter-ethnic trade, political/ethnic integration and redistribution, and economic diversification at a household level. This variability cannot be entirely accounted by environmental diversity, but was also a consequence of changing historical conditions, such as those related to endemic warfare during the fourteenth century or the integration of the area into the Inka state. In each of these scenarios, pastoralists found different ways of integrating with the non-pastoral world, both in practice and representation.
Mountain Pastoralism in the Andes during Colonial Times
Authors: Montero Raquel Gil 
Published: May 2010

Abstract
This article summarizes part of the history of the Andean herders during the colonial period. After the conquest, the Spaniards reorganized the American world in order to satisfy their primary needs: food, labor and transportation. During the silver boom of the late sixteenth and early seventeenth centuries, Potosí, the most important mining city in the Andes, surpassed 130,000 inhabitants, and there were many other settlements around smaller mining centres. All these urban inhabitants needed to be fed, and because of the location of these cities, food was often brought from distant places. This article shows how the pastoral peoples of the Andes managed to participate in, and adapt to, the colonial economy while at the same time retaining their pastoral way of life.
Pastoralism and the Making of Colonial Modernity in Kulu, 1850-1952
Authors: Singh Chetan 
Published: May 2010

Abstract
The pre-colonial, western Himalayan principality of Kulu presented a traditional balance between migratory pastoralism, settled agriculture and market dealings. The state encouraged and thrived upon this combination of diverse activities. This situation was profoundly transformed by the establishment of the colonial rule. New notions of property and rights of land use were imposed. The traditional claims to pastures and forest resources by the village communities were questioned. Colonial land revenue and forest regulations marginalized the pastoralists and shifted the balance towards agriculture. In independent India, too, local communities have been ignored and the state continues to exercise virtually exclusive control over forest resources.
The Demise of European Mountain Pastoralism: Spain 1500-2000
Authors: Collantes Fernando 
Published: May 2010

Abstract
This article deals with the evolution of mountain pastoralism in Spain from 1500 to 2000. There were two major ruptures for the Spanish livestock sector during this period: the constitution of a market society in the early nineteenth century and the incorporation of industrial inputs for animal feeding from 1960 onwards. Only the second of these ruptures shifted comparative advantage from the mountains to the lowlands, but both of them created pressures for intensification and the gradual demise of pastoralist segments within the annual cycle of livestock raising.
Erfassung der adaptiven genetischen Variation der Eiche im Hinblick auf den Klimawandel | Assessment of adaptive genetic variation in oaks with relation to climate change
Authors: Gailing Oliver 
Published: May 2010

Climate change is projected to lead to a major reorganization of our forests. For example, higher annual mean temperatures, longer growth seasons and drier summers are predicted for many parts of central and southern Europe, and in North America. In order to understand the genetic adaptation to climate change we need a better understanding of the genetic regulation of key traits involved in tolerance of water and temperature stress. Oaks (Quercus spp.) are excellent model species to study the adaptation of forest trees to changing environments. They show a wide geographic distribution in Europe and in North America as dominant tree species in many forests growing under a wide range of climatic and edaphic conditions.
With the availability of a growing amount of functional and expressional candidate genes we are now able to test the functional importance of genes by associating nucleotide variation in these genes with phenotypic variation in adaptive traits in segregating or natural populations. Studies trying to associate genetic variation with phenotypic variation in adaptive traits can be performed in full-sib families derived from controlled crosses (Quantitative Trait Loci [QTL] mapping) or in natural populations (association mapping). For several important adaptive traits QTL were mapped, the underlying genes have to be tested in natural populations. A future objective is to test whether genes that underlie phenotypic variation in adaptive traits are involved in local genetic adaptation and viability selection at the seedling stage, linked to reciprocal transplant experiments in order to assess the performance over climatic gradients.
Measurements of mid-winter spatial distribution of meltwater saturation
Authors: Kapil J.C. , Kumar Anupam , Negi P.S. 
Published: May 2010

AbstractUnder melt–freeze conditions crusts may evolve within a snowpack, which may favour avalanche initiation by forming a hard bed surface for weakly bonded faceted grains. We used a parallel-probe saturation profiler (PPSP) to record the distribution of water contents within the snowpack. Diurnal effects of melt–freeze action on the growth of crusts were monitored with the help of the PPSP device. Saturation profiles were collected from a partially wet snow cover. Snow stratigraphy was conducted manually in the morning, after overnight freezing, to identify the location and the granular compositions of the crusts that had evolved. A one-to-one correspondence between the saturation spikes collected using the PPSP and the actual positions of the crusts was established. The PPSP was also used to monitor three-dimensional variations in the maximum percolation depths within a south-facing snowpack. The operation of the PPSP is faster than existing dielectric measurement techniques, so it was applied to study the spatial variability of maximum percolation depths on the slopes of different aspects.
A virtual network for estimating daily new snow water equivalent and snow depth in the Swiss Alps
Authors: Egli Luca , Jonas Tobias , Bettems Jean-Marie 
Published: May 2010

AbstractDaily new snow water equivalent (HNW) and snow depth (HS) are of significant practical importance in cryospheric sciences such as snow hydrology and avalanche formation. In this study we present a virtual network (VN) for estimating HNW and HS on a regular mesh over Switzerland with a grid size of 7 km. The method is based on the HNW output data of the numerical weather prediction model COSMO-7, driving an external accumulation/melting routine. The verification of the VN shows that, on average, HNW can be estimated with a mean systematic bias close to 0 and an averaged absolute accuracy of 4.01 mm. The results are equivalent to the performance observed when comparing different automatic HNW point estimations with manual reference measurements. However, at the local scale, HS derived by the VN may significantly deviate from corresponding point measurements. We argue that the VN presented here may introduce promising cost-effective options as input for spatially distributed snow hydrological and avalanche risk management applications in the Swiss Alps.
Distribution of seasonal snow cover in central and western Himalaya
Authors: Kulkarni Anil V. , Rathore B.P. , Singh S.K. , Ajai  
Published: May 2010

AbstractIndian rivers originating in the Himalaya depend on seasonal snow-cover melt during crucial summer months. The seasonal snow cover was monitored using Advanced Wide Field Sensor (AWiFS) data of the Indian Remote Sensing Satellite (IRS) and using the Normalized Difference Snow Index (NDSI) algorithm. The investigation was carried out for a period of 3 years (2004/05, 2005/06 and 2006/07) between October and June. A total of 28 sub-basins of the Ganga and Indus river basins were monitored at intervals of 5 or 10 days. Approximately 1500 AWiFS scenes were analyzed. A combination of area–altitude distribution and snow map was used to estimate the distribution of snow cover in altitude zones for the individual basins and for the western and central Himalaya. Hypsographic curve and snow-free area was used to estimate monthly snow-line elevation. The lowest snow-line altitude in the winters of 2004/05, 2005/06 and 2006/07 was observed at 2480 ma.s.l. on 25 February 2005. In Ravi basin for the year 2004/05, snow accumulation and ablation were continuous processes throughout the winter. Even in the middle of winter, the snow area was reduced from 90% to 55%. Similar trends were observed for 2005/06 and 2007/08. In Bhaga basin, snowmelt was observed in the early part of the winter, i.e. in December, and no significant melting was observed between January and April.
Quantification of the hand hardness test
Authors: Höller P. , Fromm R. 
Published: May 2010

AbstractSnow hardness is the resistance to penetration. It can be measured by the Swiss rammsonde or estimated by the hand hardness test. According to the International Classification of Seasonal Snow on the Ground (ICSSG), snow hardness is divided into five levels (without ice). However, the hand test is subjective and provides only an index value of snow hardness. The main objective of this study was to determine the hardness using an alternative method which can be applied in the same way as the hand test and which can deliver accurate data. In this study the conventional hand hardness test was used; additionally, a digital force gauge (push-pull gauge) was applied where the hardness was measured horizontally (for comparison with the hand hardness test). The push-pull gauge could be provided with five different attachments. The size and design of each attachment corresponded to the equivalent application of the hand hardness test (fist, four fingers, one finger, pencil, knife). This paper indicates how snow hardness measured by hand is related to snow hardness measured with the push-pull gauge. Moreover, the variability of the hardness, both vertical and horizontal, is demonstrated. The results show agreement with the ICSSG for hand hardness indices 3, 4 and 5; for hand hardness indices 1 and 2, the range indicated by the ICSSG is below the lower quartile of the measurements.
A simple analytical model for pressure on obstacles induced by snow avalanches
Authors: Faug Thierry , Chanut Benoit , Beguin Rémi , Naaim Mohamed , Thibert Emmanuel , Baroudi Djebar 
Published: May 2010

AbstractThe forces snow avalanches are able to exert on protection dams or buildings are of crucial interest in order to improve avalanche mitigation measures and to quantify the mechanical vulnerability of structures likely to be damaged by snow avalanches. This paper presents an analytical model that is able to calculate these forces taking into account dead-zone mechanisms. First, we present a 2-D analytical hydrodynamic model describing the forces on a wall overflown by gravity-driven flows down an inclined plane. Second, the 2-D model is successfully validated on discrete simulations of granular flows. Third, we provide ingredients to extend the 2-D model to flows of dry and cold snow. Fourth, we propose a simplified 3-D analytical model taking into account lateral fluxes. Finally, the predictions from the simplified 3-D analytical model are successfully compared to recent measurements on two full-scale snow avalanches released at the Lautaret site in France.
Climate-change studies in the western Himalaya
Authors: Shekhar M.S. , Chand H. , Kumar S. , Srinivasan K. , Ganju A. 
Published: May 2010

AbstractThe high Himalayan mountains in the north of India are important sources for generating and maintaining the climate over the entire northern belt of the Indian subcontinent. They also influence extreme weather events, such as the western disturbances over the region during winter. The work presented here describes some current trends in weather and climate over the western Himalaya and suggests some possible explanations in the context of climate change. The work also shows how the special features of Indian orography in the western Himalaya affect climate change in the long term, changing the pattern of precipitation over the region. Data analysis of different ranges of the western Himalaya shows significant variations in temperature and snowfall trends in the past few decades. Possible explanations for the changing climate over the western Himalaya are proposed, in terms of variations in cloudiness. The possible effects of climate change on the number of snowfall days and the occurrences of western disturbances over the western Himalaya are also analysed.
Hyperspectral analysis of snow reflectance to understand the effects of contamination and grain size
Authors: Singh S.K. , Kulkarni A.V. , Chaudhary B.S. 
Published: May 2010

AbstractReflectance data for contaminated and different grain-size snow were collected using a spectroradiometer ranging from 350 to 2500 nm. Contamination was predominantly due to soil. The radiometer data were binned at 10 nm intervals by averaging, and then principal component analysis, shape, size and strength of the absorption peak, first and second derivatives were computed, providing information about the effect of grain size and contamination on snow reflectance. Relative strength for contamination and grain size showed a distinct reverse pattern at 1025 nm after continuum removal. Band absorption depth at 1025 nm showed an increase with increasing snow grain size, whereas the band depth was found to decrease with increased soil contamination. The curve shape was right asymmetric and showed a change to left asymmetry with increase in contamination. The first derivative of reflectance in the visible region showed a shift of peak due to contamination. Soil contamination significantly reduced the albedo of snow at a low level of contamination but showed little influence at higher level. Relative strength, shape of curve and reflectance characteristics have shown the potential to identify the influence of contamination and grain-size based metamorphism using satellite-based hyperspectral remote sensing.
Observation of temperature gradient metamorphism in snow by X-ray computed microtomography: measurement of microstructure parameters and simulation of linear elastic properties
Authors: Srivastava P.K. , Mahajan P. , Satyawali P.K. , Kumar V. 
Published: May 2010

AbstractThe process of temperature gradient metamorphism in snow strongly affects the microstructure and associated mechanical properties of the snow. The purpose of this study was to: (1) examine the temporal variations in three-dimensional snow microstructure under the influence of a strong temperature gradient for 6 days using X-ray computed microtomography (μCT); and (2) numerically simulate the linear elastic properties of snow from microtomographic data using a voxel-based finite-element technique. The temporal changes in the snow structure were analyzed in terms of density, specific surface area (SSA), thickness distribution of ice matrix and pores, structure model index and mean intercept length (MIL) fabric tensor. The structural indices and orthotropic elastic compliance matrix were computed over several sub-volumes within the reconstructed volume to account for statistical uncertainties. The mean density increased by about 14% on day 1 and no significant trend was observed thereafter. The SSA decreased by 22%, whereas both the ice and pore thickness distributions widened with time. The computed Young’s moduli were 1.5–4 times larger than previously published dynamic measurements and found to be significantly correlated with ice volume fraction and MIL fabric measures. The increasing trend in computed moduli during the experiment is consistent with the observed development of thicker vertical ice structures. Multiple linear regression models of elastic compliances using fabric tensor formulation and ice volume fraction could explain 89.9–93.0% of the variance. Our results suggest a strong dependence of elastic properties on both density and microstructural fabric.
Growth of melt–freeze clusters and formation of impeding layers to water flow in snow irradiated by a sun simulator under controlled laboratory conditions
Authors: Kapil J.C. , Prasher C. , Datt P. , Satyawali P.K. 
Published: May 2010

AbstractStratigraphic boundaries at fine-to-coarse transitions in snow can introduce impeding layers to infiltrating water. In our present investigation, such impeding horizons were observed within sub-freezing homogeneous snow as a consequence of subsurface melting caused by the penetration of solar radiation. This new texture impeded the further downward flow of meltwater at fine-to-coarse transitions, leading to the formation of low-permeability melt–freeze crusts following multiple melt–freeze cycles. In this work, a large sub-freezing (–6°C) homogeneous sample, consisting of small rounded grains, was periodically exposed to intense radiation generated by a sun simulator. Due to the penetration of shortwave radiation into the snow, subsurface melting caused the growth of melt–freeze polycrystals from clustered rounded crystals. Variations in mass growth (%) of melt–freeze polycrystals and mass loss (%) of grain clusters were studied within the sub-freezing snow with respect to different melt–freeze cycles. In this work, we study the growth of melt–freeze polycrystals in the top and bottom sub-layers with respect to collective saturation. Saturation profiles from the snow were recorded with a parallel-probe saturation profiler (PPSP) device, sampling at vertical intervals of 7mm, after each melting cycle. Intrinsic permeabilities across different stratified sub-layers were monitored in relation to saturation as a function of different melt–freeze cycles. Our observations revealed that there is a significant decrease in intrinsic permeability for the first few top sub-layers. Also, permeability in the second topmost sub-layer was less than that in the topmost sub-layer directly interacting with the radiation. These results support the evolution of a new coarse grain texture within the homogeneous snow that subsequently converts into a layer of low permeability. In the various transects of the snow sample, two melt–freeze crusts and one ice crust were manually identified through stratigraphic mapping. A correlation was also established between the saturation spikes recorded with the help of the PPSP and corresponding depth positions of the crusts.