bluuebunny/crossref_metadata_2025 huggingface dataset:
Hypoxia Induces Cysteine-rich 61, Vascular Endothelial Growth Factor, and Interleukin-8 Expressions in Human Nasal Polyp Fibroblasts: An Implication of Neutrophils in the Pathogenesis of Nasal Polyposis
Authors: Shun Chia-Tung , Lin Sze-Kwan , Hong Chi-Yuan , Huang Hung-Meng , Liu Chia-Ming
Published: January 2011

Background

The purpose of this article was to elucidate the roles of neutrophils and angiogenesis factors in the pathogenesis of nasal polyposis. The effect of hypoxia on the expressions of angiogenesis factors as cysteine-rich 61 (Cyr61) and vascular endothelial growth factor (VEGF) and neutrophil chemoattractant as interleukin (IL)-8 in nasal polyp fibroblasts (NPFs), and the role of nuclear factor kappa B (NF-kappaB) in this reaction were investigated. The action of Cyr61 on the synthesis of VEGF and IL-8 in NPFs was also examined.

Methods

Primary cultures of NPFs were established from nasal polyps (NPs). Productions of Cyr61, VEGF, and IL-8 by NPFs under hypoxia were detected by Western blot (Cyr61 and VEGF) or enzyme-linked immunosorbent assay (ELISA; IL-8). Immunohistochemical staining was used to examine the relation between fibroblastic expression of Cyr61 and neovascularization/neutrophil infiltration in NPs.

Results

Western blot showed that the hypoxia inducer CoCl2 stimulated Cyr61 synthesis in NPFs in a time-dependent manner, reaching a peak at 24 hours. Bay-117082 (a specific NF-kappaB inhibitor) attenuated the levels of Cyr61 stimulated by hypoxia. Cyr61 induced IL-8 secretion and VEGF synthesis by NPFs, as evidenced by Western blot and ELISA analysis. Bay-117082 abolished hypoxia-stimulated IL-8 and VEGF synthesis, whereas Cyr61 restored the stimulative effect of hypoxia readily. Immunohistochemical staining revealed the presence of Cyr61 and IL-8 in NPFs. Neutrophils and capillaries aggregating around these NPFs were frequently found.

Conclusion

Under hypoxia, NPFs contribute to NP propagation by expressing Cyr61, which subsequently stimulates VEGF and IL-8 production, leading to angiogenesis and activating neutrophil infiltration in NPs.
Critical Appraisal and Meta-Analysis of Nasal Surgery for Obstructive Sleep Apnea
Authors: Li Hsueh-Yu , Wang Pa-Chun , Chen Yu-Pin , Lee Li-Ang , Fang Tuan-Jen , Lin Hsin-Ching
Published: January 2011

Background

Nasal surgery is commonly involved in surgical treatment for obstructive sleep apnea (OSA). The aim of this study was to investigate the outcomes of nasal surgery for OSA using evidence-based methodology.

Methods

The MedLine database (1999∼2009) was searched for original articles published in peer-reviewed journals concerning nasal surgery for snoring/sleep apnea. Data extracted from these articles were reviewed and analyzed using meta-analysis technology.

Results

Thirteen articles were critically appraised. Two studies provided control groups and 11 articles (84.6%) consisted of prospective noncontrolled clinical trials (level II in evidence strength). The weighted mean apnea/hypopnea index measured by polysomnography in nine studies decreased from 35.2 ± 22.6 to 33.5 ± 23.8 event/hour after nasal surgery (overall, p = 0.69). The pooled success rate of nasal surgery in treating OSA was 16.7%. Epworth Sleepiness Scale scores in eight studies decreased from 10.6 ± 3.9 to 7.1 ± 3.7 (overall, p <0.001). Nasal surgery for snoring assessed by individual questionnaires and visual analog scale reported significant improvement (p < 0.05).

Conclusion

The critical literature appraisal and meta-analyses show that nasal surgery can effectively reduce daytime sleepiness and snoring. However, the efficacy of nasal surgery in treating OSA is limited.
Assessments of Nasal Bone Fracture Effects on Nasal Airflow: A Computational Fluid Dynamics Study
Authors: Chen Xiao Bing , Lee Heow Pueh , Chong Vincent Fook Hin , Wang De Yun
Published: January 2011

Background

The aim of this study was to evaluate effects of nasal bone fractures on nasal aerodynamic flow patterns using computational fluid dynamics (CFD) simulations.

Methods

A three-dimensional model of nasal cavity with a nasal bone fracture was constructed from computerized tomography (CT) scans of a patient with use of software Mimics 13.0 (The Materilize Group, Leuven, Belgium). CFD simulations were performed using Fluent 6.3 (ANSYS, Inc., Canonsburg, PA) with a turbulent flow model. Numerical results were presented with velocity, streamline, and pressure contour distributions in left and right nasal cavities and were compared with those of a healthy one. Possible outcomes on functional performances or patencies of the nose were also examined and discussed.

Results

For the nose with a nasal bone fracture, distributions of velocity contours showed there was more airflow in the right nasal cavity than in the left one, especially for inspiration status. In the left cavity, the airflow was redirected irregularly and there were also more circulations with larger sizes, higher pressure jumps, and greater wall shear stresses. Flow partitioning in the right and left cavities was noticeable with a larger nasal resistance compared with the healthy one. When the inspirational flow rate was increased, pressure jump from the nostril to the nasopharynx increased faster.

Conclusion

The aerodynamic flow was redistributed greatly for the nose with a nasal bone fracture compared with the healthy one, which might affect local normal nasal functions. Such physical assessments of nasal airflow based on a model from the patients’ CT scans may help clinicians determine the best treatment in advance.
Alterations of Vasoactive Intestinal Polypeptide Receptors in Allergic Rhinitis
Authors: Kim Dae-Hyung , Park Il-Ho , Cho Jung-Sun , Lee You-Mi , Choi Hyuk , Lee Heung-Man
Published: January 2011

Background

Vasoactive intestinal peptide (VIP) is one of the parasympathetic neurotransmitters involved in the regulation of airway mucus secretion. The biological functions of VIP are mediated through two receptors (vasoactive intestinal peptide receptor type 1 [VPAC1R] and type 2 [VPAC2R]). The purpose of this study was to determine the distribution of VIP receptors and to compare the level of VIP receptor expression in the nasal mucosa of patients with allergic rhinitis and normal controls.

Methods

Inferior turbinate mucosal samples were obtained from 20 normal subjects and 20 patients with allergic rhinitis. VPAC1R and VPAC2R mRNA was extracted from the nasal mucosa, and then a reverse-transcription—polymerase chain reaction was performed. Sections were immunostained using specific antibodies for VIP receptors. Western blot analysis was used to analyze differences in the level of expression of VPAC1R and VPAC2R protein between patients with allergic rhinitis and normal controls.

Results

The level of expression of VIP receptor mRNA and protein in patients with allergic rhinitis was significantly increased compared with normal nasal mucosa. VIP receptor immunoreactivity was detected on the nasal epithelium and submucosal glands in nasal specimens from both normal controls and patients with allergic rhinitis. In the epithelium from patients with allergic rhinitis, VIP receptor immunoreactivity was strong, whereas in the nasal epithelium from normal subjects it was faint.

Conclusion

These results suggest that an increased expression level of VIP receptors is one possible explanation for nasal hyperresponsiveness in patients with allergic rhinitis.
Early Bronchial Involvement in Children with Allergic Rhinitis
Authors: Ciprandi Giorgio , Capasso Michele , Tosca Maria Angela
Published: January 2011

Background

Allergic rhinitis (AR) may be frequently associated with asthma or precede it. Bronchial involvement in AR is usually detected by spirometry. Forced expiratory volume in 1 second (FEV1) is considered a reliable parameter for asthma diagnosis. However, forced expiratory flow at 25–75% (FEF25–75) could be considered a possible marker of early bronchial involvement in AR; indeed, it has been proposed that FEF25–75 values <70% of predicted may predict this evolution. The aim of this study was to evaluate a large cohort of children with AR to define an FEV1 value corresponding to impaired FEF25–75 values.

Methods

Eight hundred fifty AR children (555 boys; median age, 10 years) were studied. Spirometry and skin-prick test were performed in all of them. Descriptive statistic and multivariate analysis were considered.

Results

Three-hundred (35.3%) patients had FEF25–75 values <70% of predicted. Still, normal FEV1 values were associated with overt impaired FEF25–75 values and the cutoff value was 83%.

Conclusion

Spirometry should be adequately interpreted in AR patients; indeed, an FEV1 cutoff value of 83% detects with good efficiency AR children with early bronchial impairment.
Dolichandrone Platycalyx: New Entomophilous Pollen—A Report on Pollen Sensitization in Allergic Individuals
Authors: Mridula P.A. , Mahesh P.A. , Abraham Jacob N. , Amrutha D.H. , Agashe S.N. , Sitesh Roy , Vedanthan P.K.
Published: January 2011

Background

Dolichandrone platycalyx, commonly known as Nile trumpet tree, is believed to have originated in East Africa. However, this and the variants of this tree are found in Europe, Asia, and America (California and Florida). The tree mostly grows in tropical climates, but temperate species are also found. This study was designed to evaluate the allergenicity of D. platycalyx, one of the most common entomophilous avenue trees in Karnataka state, and to determine the pollen production of D. platycalyx.

Methods

All of the patients with allergic rhinitis and asthma attending a tertiary care center in South India during August 2007 to March 2008 underwent a detailed clinical evaluation and skin-prick testing to common allergens along with D. platycalyx. Control subjects without any symptoms of respiratory allergy also underwent skin testing. The pollen counts were determined for a mature unopened flower of D. platycalyx.

Results

A total of 317 subjects with respiratory allergy and 30 controls were included in the study. A significant percentage (16.1%) of patients evaluated were observed to be sensitive to Dolichandrone pollen extract by skin-prick testing, whereas none of the control subjects were found to be sensitized. D. platycalyx was the fourth most common sensitizer after Parthenium hysterophorus, Prosopis juliflora, and Artemesia vulgaris. D. platycalyx was found to be a moderate pollen producer at 66,000 pollens/flower.

Conclusion

Sensitization to D. platycalyx is common in subjects with respiratory allergies. The clinical relevance of this sensitization and other entomophilous plants needs additional study.
Vicious circle in power sector
Authors: Thanju Jeevan P
Published: January 2011

Not available.DOI: 10.3126/hn.v7i0.4221Hydro Nepal Journal of Water, Energy and EnvironmentVol 7, July, 2010 Page: 8 Uploaded Date: 28 January, 2010
Total Run-of-River type Hydropower Potential of Nepal
Authors: Jha Raghunath
Published: January 2011

The total hydropower potential of Nepal was assessed as 83,500 MW in 1966 by Dr. Hari Man Shrestha dur-ing his PhD research work in former USSR. Since then, no further study has been done in this feld. The hydropower potential estimate has been used by Nepal Electricity Authority (NEA), Water and Energy Commission Secretariat (WECS) and Department of Electricity Development (DOED) for power development, licensing and policy making. However, keeping in view recent advancements in computer technology that offer many benefits to the field of water resources and the importance of power estimation in Nepal, Dr. Shrestha’s estimate needs further review and updat-ing. The present study has mainly used the hydro-meteorological data of Department of Hydrology and Meteorology (DHM) for hydrological analysis of all the rivers in Nepal including the three big rivers, viz., Saptakoshi, Narayani and Karnali, and other medium and small rivers. Incorporating GIS and the Hydropower Model that has specifcally been developed by the author, the power potential and annual energy estimate on an run-of-the-river (ROR) basis of the entire country has been worked out. The result shows that the power potential and annual energy estimates of Na-rayani, Saptakoshi and Karnali River basins at Q40% (fow exceedence) and 80% efficiency are 17800, 17008, 15661 MW and 113373, 108817, 102324 GWh, respectively. The Mahakali River would yield only 2262 MW of hydropower and 14981 GWh of energy annually. The other water sources in Nepal would have a total power potential of 1105 MW and a combined annual energy of 7043 GWh. Thus, the total hydropower potential and corresponding annual energy capacity of Nepal on a ROR basis at Q40%, and 80% efficiency is 53,836 MW and 346538 GWh, respectively.Key words: Hydropower potential; Run-of-River (ROR); GIS; Hydropower Model; NepalDOI: 10.3126/hn.v7i0.4226Hydro Nepal Journal of Water, Energy and Environment Vol 7, July, 2010Page: 8-13Uploaded date: 31 January, 2011
Nam Theun 2 Hydropower Project and Hydropower Development in Laos
Authors: Phomsoupha Xaypaseuth
Published: January 2011

Hydropower development and exporting electricity to neighboring countries is a success story in Laos. Several projects are under construction and some projects are already exporting electricity. The Nam Theun 2 Hydro-power Project (1000MW+86MW) started commercial operation on 15 March 2010. This project is exporting electricity to Thailand which is part of the MOU signed between Governments of Thailand and Laos for exporting 7000 MW to Thailand. In almost all projects, the Govt. of Laos is also a share holder.Key words: Hydropower development; Cross border electricity export; Nam Theun 2 Hydropower Project; LaosDOI: 10.3126/hn.v7i0.4227Hydro Nepal Journal of Water, Energy and Environment Vol 7, July, 2010Page: 14-16Uploaded date: 31 January, 2011
Miracle in Rajasthan: Traditional Practice of Rainwater Harvesting
Authors: Thanju Jeevan P. , Shrestha Basanta D
Published: January 2011

Paper report.DOI: 10.3126/hn.v7i0.4229Hydro Nepal Journal of Water, Energy and Environment Vol 7, July, 2010 Page: 20-22 Uploaded date: 31 January, 2011
Rain Water Harvesting in Kathmandu
Authors: Thanju Jeewan P. , Shrestha Basanta D.
Published: January 2011

Not available.DOI: 10.3126/hn.v7i0.4230Hydro Nepal Journal of Water, Energy and Environment Vol 7, July, 2010 Page: 17-19 Uploaded date: 31 January, 2011
Design of Mini Grid for SHP Plants
Authors: Singh S. N. , Sharma M. P. , Singh Ajit
Published: January 2011

The supply of power to remote rural areas in India from Small Hydropower Projects (SHP)/renewable en-ergy power projects in cost effective and sustainable manner requires the optimum design of mini-grids. The present paper deals with the design of mini grids of nine SHP plants presently running in isolated mode only for 8 hrs/day wasting the energy of 16 hrs/day. Based on system layouts, transmission routing, line length and selection of conduc-tor, 5 different alternates of mini-grids were developed to connect these SHPs together as well as with the nearby 33 kV grid substations located at approximately 15, 17 and 9 km from nearby SHPs in order to improve the load factor. The optimization of these alternates on the basis of the Break Even Point (BEP) has indicated that Alternate-V has been found as optimum alternative for the study area with shortest line length, low line losses and minimum capital investment for the mini-grid implementation.Key words: Small Hydropower Project (SHP) station; Mini-grid; Remote rural areas; Break Even Point; IndiaDOI: 10.3126/hn.v7i0.4235Hydro Nepal Journal of Water, Energy and EnvironmentVol 7, July, 2010Page: 38-47Uploaded date: 31 January, 2011
The Slaughter House Waste Management
Authors: Ali Arshad , Hashmi Hashim Nisar , Akber Habib
Published: January 2011

Thousands of animals are slaughtered every year in Pakistan, but unfortunately there is no proper mecha-nism nor waste water management system to handle the effuent discharge of the slaughtering process. Therefore, this study was designed to evaluate the potential hazards associated with slaughter houses, by analyzing waste-water characteristics and designing a suitable treatment system for safe effuent disposal. The results obtained indicate that the wastewater parameters of the slaughter house do not meet the requirements of the local effuent dis-charge standards. The average wastewater characteristics in terms of COD, BOD, TDS, TSS, turbidity and pH observed were 9600mg/L, 7450 mg/L, 1650 mg/L, 2280 mg/L, 1489 NTU and 6.5, respectively. The results of plain sedimenta-tion point out that the maximum removal effciency of COD, BOD, TDS, TSS and turbidity at 80 minutes of detention time could be obtained as13%, 21%, 10%, 30% and 39%, respectively. Out of the three coagulants tested, the alum was tested out as the most suitable coagulant in terms of its treatability performance, which gives 80% COD removal compare to lime and magnesium sulfate that gives about 56% and 71% removal, respectively. The activated system designed consists of 12m x 7.5m x 3.5m rectangular aeration tank and 12m x 7m x 5m secondary sedimentation tank. The amount of air, power and the major nutrient (N and P) required for this system were worked out as 136m3/min, 7.8kW, 152 N-kg/day and 30 P-kg/day, respectively.Key words: Slaughter house effluent; Sedimentation; Alum; Activated sludge system; PakistanDOI: 10.3126/hn.v7i0.4236Hydro Nepal Journal of Water, Energy and Environment Vol 7, July, 2010Page: 48-53Uploaded date: 31 January, 2011
Short Term Optimal Generation Scheduling of Narmada Cascaded Hydro Electric System
Authors: Mahor Amita , Rangnekar Saroj
Published: January 2011

Generation scheduling of cascaded hydropower plants at same stream of river is imperative to harness river water energy in an optimal manner. Along with hydropower, multipurpose hydropower plants are also fulfilling irrigation requirement of nearby zones. Irrigation requirements from immediate plants, natural inflows from tributaries and evaporation losses between successive reservoirs affects water levels in both reservoirs and operating heads. In this paper all of the above factors are included in water continuity equations for optimization problem formulation of a real operated cascaded hydroelectric system located on the Narmada River in Madhya Pradesh, India. Time Varying Acceleration Coefficients PSO (TVAC_PSO) has been used to determine the optimal generation schedule of the above system. The results obtained are compared with Novel Self Adaptive Inertia Weight PSO (NSAIW_PSO), and are found to give a better solution.Key words: Hydroelectric power generation; Novel Self Adaptive Inertia Weight PSO; Linearly Decreasing Inertia Weight PSO; Time Varying Acceleration Coefficient PSO; Short term generation scheduling; Narmada River; Madya Pradesh (India)DOI: 10.3126/hn.v7i0.4241Hydro Nepal Journal of Water, Energy and Environment Vol. 7, July, 2010Page: 71-80Uploaded date: 31 January, 2011
Public Hearing in the EIA Process of Hydropower Development
Authors: Sharma Bharat Mani
Published: January 2011

This paper discusses the methodology for public hearings, mandatory legal provisions and their importance in the process of hydropower development. A public hearing is both a process of information sharing, discussion and negotiation, and an end result of allocating compensation and other impact mitigation activities. It is based on prin-ciples of equity and social justice. Any development project that brings changes to the existing biological, physical, socio-economic and cultural environment should be carefully examined considering the status of the stakeholders. A good public hearing process can strengthen private sector incentives to help government and the people to attain a nation’s hydropower development goals and, at the same time, address local opportunities and issues. A good public hearing is important for time-effectiveness, cost-effectiveness and sustainability of hydropower projects. Promises too early in the public hearing process tend to raise high expectations which, if misunderstood or unmet later on, may lead to negative consequences.There is an urgent need to standardize public hearings in the IEE and EIA processes of hydropower projects and help proponents to conduct public hearings effectively.Key words: Public hearing; EIA (Environmental Impact Assessment); IEE (Initial Environmental Examination); EPA (Environmental Protection Act); EPR (Environmental Protection Rules); Hydropower development; NepalDOI: 10.3126/hn.v7i0.4242Hydro Nepal Journal of Water, Energy and Environment Vol. 7, July, 2010Page: 81-84Uploaded date: 31 January, 2011
Microstructural change around a needle probe to measure thermal conductivity of snow
Authors: Riche Fabienne , Schneebeli Martin
Published: January 2011

The thermal conductivity of snow determines, to a large extent, ground heat flux and snow metamorphism. One common method of measuring the thermal conductivity of snow is with a needle probe. We measured the microstructural changes in the snow around a typical needle using micro- computed tomography. The insertion of the needle probe caused structural changes up to a radial distance of 0.5-1 mm. Using a commercial needle probe with short (30 s) heating time, we measured thermal conductivity values in snow that were 50% lower than the conductivity measured using a calibrated guarded hot-plate apparatus. Numerically simulated time-temperature curves with an introduced air gap that simulated the needle damage reproduced the observed needle-probe results well, confirming that poor contact resistance between the needle and the snow will lead to measurement discrepancies and a large bias. While most measurements in snow have been done using a long heating time and are not subject to this error, the thermal conductivity of snow measured with needle probes with short measurement times should be avoided. This same effect is probably observed in other brittle and highly porous materials, a condition that may not be widely appreciated.
A unifying framework for iceberg-calving models
Authors: Amundson Jason M. , Truffer Martin
Published: January 2011

We propose a general framework for iceberg-calving models that can be applied to any calving margin. The framework is based on mass continuity, the assumption that calving rate and terminus velocity are not independent and the simple idea that terminus thickness following a calving event is larger than terminus thickness at the event onset. The theoretical, near steady-state analysis used to support and analyze the framework indicates that calving rate is governed, to first order, by ice thickness, thickness gradient, strain rate, mass-balance rate and backwards melting of the terminus; the analysis furthermore provides a physical explanation for a previously derived empirical relationship for ice-shelf calving (Alley and others, 2008). In the calving framework the pre- and post-calving terminus thicknesses are given by two unknown but related functions. The functions can vary independently of changes in glacier flow and geometry, and can therefore account for variations in calving behavior due to external forcings and/or self-sustaining calving processes (positive feedbacks). Although the calving framework does not constitute a complete calving model, any thickness-based calving criterion can easily be incorporated into the framework. The framework should be viewed as a guide for future attempts to parameterize calving.
Discovery of a nanodiamond-rich layer in the Greenland ice sheet
Authors: Kurbatov Andrei V. , Mayewski Paul A. , Steffensen Jorgen P. , West Allen , Kennett Douglas J. , Kennett James P. , Bunch Ted E. , Handley Mike , Introne Douglas S. , Que Hee Shane S. , Mercer Christopher , Sellers Marilee , Shen Feng , Sneed Sharon B. , Weaver James C. , Wittke James H. , Stafford Thomas W. , Donovan John J. , Xie Sujing , Razink Joshua J. , Stich Adrienne , Kinzie Charles R. , Wolbach Wendy S.
Published: January 2011

We report the discovery in the Greenland ice sheet of a discrete layer of free nanodiamonds (NDs) in very high abundances, implying most likely either an unprecedented influx of extraterrestrial (ET) material or a cosmic impact event that occurred after the last glacial episode. From that layer, we extracted n-diamonds and hexagonal diamonds (lonsdaleite), an accepted ET impact indicator, at abundances of up to about 5×106 times background levels in adjacent younger and older ice. The NDs in the concentrated layer are rounded, suggesting they most likely formed during a cosmic impact through some process similar to carbon-vapor deposition or high-explosive detonation. This morphology has not been reported previously in cosmic material, but has been observed in terrestrial impact material. This is the first highly enriched, discrete layer of NDs observed in glacial ice anywhere, and its presence indicates that ice caps are important archives of ET events of varying magnitudes. Using a preliminary ice chronology based on oxygen isotopes and dust stratigraphy, the ND-rich layer appears to be coeval with ND abundance peaks reported at numerous North American sites in a sedimentary layer, the Younger Dryas boundary layer (YDB), dating to 12.9 ± 0.1 ka. However, more investigation is needed to confirm this association.
Identification and characterization of alpine subglacial lakes using interferometric synthetic aperture radar (InSAR): Brady Glacier, Alaska, USA
Authors: Capps Denny M. , Rabus Bernhard , Clague John J. , Shugar Daniel H.
Published: January 2011

The temporary storage and subsequent release of water at glacial margins can cause severe flooding in downstream areas and substantially impact glacier dynamics. Alpine subglacial lakes may not be identified until they become subaerially exposed or release a jokulhlaup. We use interferometric synthetic aperture radar (InSAR) to identify and characterize three dynamic alpine subglacial lakes of Brady Glacier, Alaska, USA. We quantify changes in vertical displacement of the glacier surface and lake volumes from September 1995 through March 1996 using European Remote-sensing Satellite-1/-2 (ERS- 1/-2) tandem data. In the autumn, subsidence ranged from 4 to 26cmd-1 and the volume of water discharged ranged from 22 000 ± 2000 to 243 000 ± 14 000m3d-1. Subsidence and discharge rates declined significantly during the winter and continued at a lesser rate through March. Application of this technique may allow researchers to locate alpine subglacial lakes years or decades before they begin to release hazardous outburst floods and substantially impact glacier dynamics.
Strong-wind events and their influence on the formation of snow dunes: observations from Kohnen station, Dronning Maud Land, Antarctica
Authors: Birnbaum Gerit , Freitag Johannes , Brauner Ralf , König-Langlo Gert , Schulz Elisabeth , Kipfstuhl Sepp , Oerter Hans , Reijmer Catharina H. , Schlosser Elisabeth , Faria Sergio H. , Ries Hinnerk , Loose Bernd , Herber Andreas , Duda Michael G. , Powers Jordan G. , Manning Kevin W. , Van Den Broeke Michiel R.
Published: January 2011

Analyses of shallow cores obtained at the European Project for Ice Coring in Antarctica (EPICA) drilling site Kohnen station (75°00′ S, 00°04′ E; 2892 m a.s.l.) on the plateau of Dronning Maud Land reveal the presence of conserved snow dunes in the firn. In situ observations during three dune formation events in the 2005/06 austral summer at Kohnen station show that these periods were characterized by a phase of 2 or 3 days with snowdrift prior to dune formation which only occurred during high wind speeds of >10 m s-1 at 2 m height caused by the influence of a low-pressure system. The dune surface coverage after a formation event varied between 5% and 15%, with a typical dune size of (4 ± 2) m × (8 ± 3) m, a maximum height of 0.2 ± 0.1 m and a periodicity length of about 30 m. The mean density within a snow dune varied between 380 and 500 kg m-3, whereas the mean density at the surrounding surface was 330 ± 5 kgm-3. The firn cores covering a time-span of 22 ± 2 years reveal that approximately three to eight events per year occurred, during which snow dunes had been formed and were preserved in the firn.
On optimal stability-test spacing for assessing snow avalanche conditions
Authors: Birkeland Karl W. , Hendrikx Jordy , Clark Martyn P.
Published: January 2011

Assessing snow stability requires a holistic approach, relying on avalanche, snowpack and weather observations. Part of this assessment utilizes stability tests, but these tests can be unreliable due in part to the spatial variability of test results. Conducting more than one test can help to mitigate this uncertainty, though it is unclear how far apart to space tests to optimize our assessments. To address this issue we analyze the probability of sampling two relatively strong test results over 25 spatial datasets collected using a variety of stability tests. Our results show that the optimal distance for spacing stability tests varies by dataset, even when taking the sampling scheme and stability-test type into account. This suggests that no clear rule currently exists for spacing stability tests. Our work further emphasizes the spatial complexity of snow stability measurements, and the need for holistic stability assessments where stability tests are only one part of a multifaceted puzzle.
Using a draw-wire sensor to continuously monitor glacier melt
Authors: Hulth John
Published: January 2011

A draw-wire sensor has successfully been used to measure surface lowering due to net ablation of a glacier. A thin steel wire attached to a weight is inserted and frozen into a borehole in the ice. The draw-wire sensor, installed on a tetrahedron on the surface, retracts the wire as the snow or ice melts. Relative surface lowering of the melting surface is recorded in a data logger and may be converted to mass loss. The instrument continuously logs net ablation over several melt seasons and has the potential to be used extensively in future studies of glacier melt, whenever high temporal resolution and precision are required.
Analysis and forecast of extreme new-snow avalanches: a numerical study of the avalanche cycles of February 1999 in France
Authors: Rousselot Marie , Durand Yves , Giraud Gérald , Merindol Laurent , Daniel Luc
Published: January 2011

Snow and weather conditions typical of exceptional cycles of fresh-snow avalanches in the northern Alps are investigated using the numerical avalanche-hazard forecasting procedure of Météo-France. Sensitivity tests are performed on the events of February 1999 in the Chamonix France region, and resulting snowpack instability modeled at the massif scale is compared using adapted new indices and maps. Our results complete conclusions of earlier observation-based studies by providing new insights into the snow and weather conditions of February 1999. The large avalanches mainly resulted from large and very unstable fresh-snow accumulations. Moreover, the snowpack instability was increased locally by wind transport of light and fresh snow in February. The mechanical weaknesses resulting from the weather conditions prior to February were a key factor in explaining the unusual volumes of these avalanches. This study suggests that the operational numerical SAFRAN/Crocus/ MÉPRA (SCM) chain provides reliable forecasts of extreme new-snow avalanche situations at the massif scale, but that local-scale simulations are still needed to improve the efficiency of risk mitigation and civil protection policies.
Formation of air clathrate hydrates in polar ice sheets: heterogeneous nucleation induced by micro-inclusions
Authors: Ohno Hiroshi , Lipenkov Vladimir Ya. , Hondoh Takeo
Published: January 2011

To investigate factors influencing nucleation of air clathrate hydrates in polar ice sheets, we have performed high-resolution mapping of the distributions of soluble impurities, air bubbles and air- hydrate crystals versus depth in the Dome Fuji Antarctic ice. Significant correlation observed between the concentrations of air inclusions and impurities in ice along with frequent occurrence of impurities inside hydrate crystals suggest that micro-inclusions promote hydrate nucleation in the ice matrix. Our observations also show that the diffusive macroscopic-scale redistribution of air constituents in ice in the bubble-hydrate transition zone is controlled by the original sedimentary layering of soluble impurities acting as nucleation helpers. The results of this study are important for the correct interpretation of high-resolution gas analyses of ice cores and for better understanding the global bubble-to-hydrate transformation process in polar ice sheets.
Magnesium methanesulfonate salt found in the Dome Fuji (Antarctica) ice core
Authors: Sakurai Toshimitsu , Ohno Hiroshi , Genceli F. Elif , Horikawa Shinichirou , Iizuka Yoshinori , Uchida Tsutomu , Hondoh Takeo
Published: January 2011

Using micro-Raman spectroscopy, we identified the chemical forms of methanesulfonate salt particles in reference samples of the Dome Fuji (Antarctica) ice core. We found only (CH3SO3)2Mg nH2O among methanesulfonate salts, and this salt particle is most prevalent in the Last Glacial Maximum (LGM) ice. We suggest that during the LGM, (CH3SO3)2Mg nH2O may have formed in the atmosphere through the chemical reaction of CH3SO3H with sea salts, but probably not in the firn and ice due to the neutralization of acid in LGM ice of inland Antarctica.
Meteoric and marine ice crystal orientation fabrics from the Amery Ice Shelf, East Antarctica
Authors: Treverrow Adam , Warner Roland C. , Budd William F. , Craven Mike
Published: January 2011

The northwestern sector of the Amery Ice Shelf, East Antarctica, has a layered structure, due to the presence of both meteoric ice and a marine ice layer resulting from sub-shelf freezing processes. Crystal orientation fabric and grain-size data are presented for ice cores obtained from two boreholes ˜70 km apart on approximately the same flowline. Multiple-maxima crystal orientation fabrics and large mean grain sizes in the meteoric ice are indicative of stress relaxation and subsequent grain growth in ice that has flowed into the Amery Ice Shelf. Strongly anisotropic single-maximum crystal orientation fabrics and rectangular textures near the base of the ˜200 m thick marine ice layer suggest accretion occurs by the accumulation of frazil ice platelets. Crystal orientation fabrics in older marine ice exhibit vertical large circle girdle patterns, influenced by the complex stress configurations that exist towards the margins of the ice shelf. Post-accumulation grain growth and fabric development in the marine ice layer are restricted by a high concentration of brine and insoluble particulate inclusions. Differences in the meteoric and marine ice crystallography are indicative of the contrasting rheological properties of these layers, which must be considered in relation to large-scale ice-shelf dynamics.
Spatio-temporal variability in elevation changes of two high-Arctic valley glaciers
Authors: Barrand Nicholas E. , James Timothy D. , Murray Tavi
Published: January 2011

Uncertainties in estimates of glacier and ice-cap contribution to sea-level rise exist in part due to poor quantification of mass-balance errors, particularly those resulting from extrapolation of sparse measurements. Centre-line data are often assumed to be representative of the glacier as a whole, with little attention paid to extrapolation errors or their effect on mass-balance estimates. Here we present detailed digital elevation model (DEM) measurements of glacier-wide elevation changes over the last ~40 years at two glaciers on Svalbard, Norwegian Arctic. Austre Br0ggerbreen and Midtre Lovenbreen are shown to have lost 27.54 ± 0.98 and 9.65 ± 0.76 × 107m3 of ice, respectively, between 1966 and 2005, findings that we relate to trends in average summer air temperatures and winter accumulation. These volume losses correspond to geodetic balances of -0.58 ± 0.03 and -0.41 ± 0.03 mw.e. a-1, respectively. Our analysis revealed high spatial complexity in patterns of elevation change, varying between glaciers, between measurement intervals and within and between elevation bins. Balances from extrapolated centre-line geodetic data were the same (within errors) as those from full-coverage DEM differencing in the majority of comparisons, yet significantly underestimated balance in three instances. Additionally, field mass balance from centre-line ablation stake data underestimated balances from full-coverage geodetic measurements during three of six measurement periods. These findings may support the hypothesis that field measurements underestimate Svalbard glacier mass loss, at least partly as a result of the failure of centre-line measurements to account for glacier-wide variations in ablation. Our results demonstrate the importance of deriving accurate interpolation functions and constraining extrapolation errors from sparse measurements.
Uncertain Environments: Natural Hazards, Risk and Insurance in Historical Perspective
Authors: LÜBKEN Uwe , Mauch Christof
Published: January 2011

Natural catastrophes are not just sudden events; they are also embedded in historical patterns of vulnerability and resilience. In modern societies, risk is one of the most important principles applied to the challenges that natural hazards pose and insurance is an ever more important tool of risk management. The contributions to this special issue of Environment and History all stress the fact, however, that environmental risk is not simply a phenomenon 'out there' but the result of social, scientific, economic and cultural processes. They also illustrate that the understanding of risk varies over time.
Forestation and its Discontents: The Invention of an Uncertain Landscape in Southwestern France, 1850-Present
Authors: Temple Samuel
Published: January 2011

This article examines the politics of forestation and fire prevention in the Landes region of France, one of the largest contiguous forests in Europe. It argues that the monoculture forest of maritime pine, promoted by both the French state and local landowners in the nineteenth century, represents an uncertain environment that has eluded the control of its creators. The economic, social and political costs of this engineered forest, it is suggested, reflect the cultures of risk that have accompanied territorial transformation schemes in modern France.
From an Act of God to an Insurable Risk: The Change in the Perception of Hailstorms and Thunderstorms since the Early Modern Period
Authors: Oberholzner Frank
Published: January 2011

Despite the welcome growth in the literature on historical disasters, there has been no recent study into the change in the perception of serious storms and in particular hailstorms that took place during the Early Modern period. With the help of selected sources, some of which have hitherto never been the subject of historical research, this essay will aim to illuminate the main steps that contributed towards what was effectively a demystification of the 'wrath of God'. The essay will set the interpretation of hailstorms and the strategies for coping with them against the background of the predominant theological and scientific opinions of the day. It concludes with a short survey of cameralist suggestions towards a comprehensive hail insurance system.
From Wood to Stone: The Risk Management of Swiss Re in The Sundsvall Fire 1888
Authors: Rohland Eleonora
Published: January 2011

Through the lens of the Swiss Reinsurance Company's (today Swiss Re) nineteenth century correspondence, the Swedish and international (re-)insurance industry's risk management after the devastating fire of Sundsvall, Sweden on June 25, 1888 unfolds. The article focuses on the Swiss Reinsurance Company's post disaster 'risk-shaping' and the formation of reinsurance lobby-groups in the aftermath of the disaster. It argues that even the insurance industry's concept of 'objective risk' is not static but fluid and open to negotiation within the insurance system. Since the insurance industry works on the interface between the natural and the built environment it can influence directly how societies interact with nature. The article argues furthermore, that perceiving fire merely as a man-made hazard without considering its 'natural' context falls short of an accurate analysis, in particular concerning 'catastrophic loss' (i.e. large-scale loss) affecting (re-)insurers' geographical risk distribution.
Sharing the Risk of Hail: Insurance, Reinsurance and the Variability of Hailstorms in Switzerland, 1880-1932
Authors: Mauelshagen Franz
Published: January 2011

This paper describes part of the early history of crop insurance in Switzerland as a process of adaptation to the hazard of hail. It argues that insurance is a means of socialising hazard through risk sharing and, therefore, that adaptation is an active process influenced by various decisions both within and outside the insurance market. These decisions are as much a part of the story as is the variability of hailstorms in Switzerland. A period of more extreme hailstorms, which challenged insurance provision, occurred between 1920 and 1930 and was linked by reinsurers with climatic change. Examination of this time period will lead to a discussion of insurance in the context of the current debate on global warming, its projected impacts, and possible strategies of adaptation.
Recognizing the Repeatable Configurations of Time-Reversible Generalized Langton’s Ant Is PSPACE-Hard
Authors: Tsukiji Tatsuie , Hagiwara Takeo
Published: January 2011

Chris Langton proposed a model of an artificial life that he named “ant”: an agent- called ant- that is over a square of a grid moves by turning to the left (or right) accordingly to black (or white) color of the square where it is heading, and the square then reverses its color. Bunimovich and Troubetzkoy proved that an ant’s trajectory is always unbounded, or equivalently, there exists no repeatable configuration of the ant’s system. On the other hand, by introducing a new type of color where the ant goes straight ahead and the color never changes, repeatable configurations are known to exist. In this paper, we prove that determining whether a given finite configuration of generalized Langton’s ant is repeatable or not is PSPACE-hard. We also prove the PSPACE-hardness of the ant’s problem on a hexagonal grid.
BioMEMS and Lab-on-a-Chip Course Education at West Virginia University
Authors: Liu Yuxin
Published: January 2011

With the rapid growth of Biological/Biomedical MicroElectroMechanical Systems (BioMEMS) and microfluidic-based lab-on-a-chip (LOC) technology to biological and biomedical research and applications, demands for educated and trained researchers and technicians in these fields are rapidly expanding. Universities are expected to develop educational plans to address these specialized needs in BioMEMS, microfluidic and LOC science and technology. A course entitled BioMEMS and Lab-on-a-Chip was taught recently at the senior undergraduate and graduate levels in the Department of Computer Science and Electrical Engineering at West Virginia University (WVU). The course focused on the basic principles and applications of BioMEMS and LOC technology to the areas of biomedicine, biology, and biotechnology. The course was well received and the enrolled students had diverse backgrounds in electrical engineering, material science, biology, mechanical engineering, and chemistry. Student feedback and a review of the course evaluations indicated that the course was effective in achieving its objectives. Student presentations at the end of the course were a highlight and a valuable experience for all involved. The course proved successful and will continue to be offered regularly. This paper provides an overview of the course as well as some development and future improvements.
Nonlinear Dielectric Spectroscopy as an Indirect Probe of Metabolic Activity in Thylakoid Membrane
Authors: Fang Jie , Palanisami Akilan , Rajapakshe Kimal , Widger William R. , Miller John H.
Published: January 2011

Nonlinear dielectric spectroscopy (NDS) is a non-invasive probe of cellular metabolic activity with potential application in the development of whole-cell biosensors. However, the mechanism of NDS interaction with metabolic membrane proteins is poorly understood, partly due to the inherent complexity of single cell organisms. Here we use the light-activated electron transport chain of spinach thylakoid membrane as a model system to study how NDS interacts with metabolic activity. We find protein modification, as opposed to membrane pump activity, to be the dominant source of NDS signal change in this system. Potential mechanisms for such protein modifications include reactive oxygen species generation and light-activated phosphorylation.
Extra-Neural Metastases of Malignant Gliomas: Myth or Reality?
Authors: Beauchesne Patrick
Published: January 2011

Malignant gliomas account for approximately 60% of all primary brain tumors in adults. Prognosis for these patients has not significantly changed in recent years—despite debulking surgery, radiotherapy and cytotoxic chemotherapy—with a median survival of 9–12 months. Virtually no patients are cured of their illness. Malignant gliomas are usually locally invasive tumors, though extra-neural metastases can sometimes occur late in the course of the disease (median of two years). They generally appear after craniotomy although spontaneous metastases have also been reported. The incidence of these metastases from primary intra-cranial malignant gliomas is low; it is estimated at less than 2% of all cases. Extra-neural metastases from gliomas frequently occur late in the course of the disease (median of two years), and generally appear after craniotomy, but spontaneous metastases have also been reported. Malignant glioma metastases usually involve the regional lymph nodes, lungs and pleural cavity, and occasionally the bone and liver. In this review, we present three cases of extra-neural metastasis of malignant gliomas from our department, summarize the main reported cases in literature, and try to understand the mechanisms underlying these systemic metastases.
From Prostate to Bone: Key Players in Prostate Cancer Bone Metastasis
Authors: Thobe Megan N. , Clark Robert J. , Bainer Russell O. , Prasad Sandip M. , Rinker-Schaeffer Carrie W.
Published: January 2011

Bone is the most common site for metastasis in human prostate cancer patients. Skeletal metastases are a significant cause of morbidity and mortality and overall greatly affect the quality of life of prostate cancer patients. Despite advances in our understanding of the biology of primary prostate tumors, our knowledge of how and why secondary tumors derived from prostate cancer cells preferentially localize bone remains limited. The physiochemical properties of bone, and signaling molecules including specific chemokines and their receptors, are distinct in nature and function, yet play intricate and significant roles in prostate cancer bone metastasis. Examining the impact of these facets of bone metastasis in vivo remains a significant challenge, as animal models that mimic the natural history and malignant progression clinical prostate cancer are rare. The goals of this article are to discuss (1) characteristics of bone that most likely render it a favorable environment for prostate tumor cell growth, (2) chemokine signaling that is critical in the recruitment and migration of prostate cancer cells to the bone, and (3) current animal models utilized in studying prostate cancer bone metastasis. Further research is necessary to elucidate the mechanisms underlying the extravasation of disseminated prostate cancer cells into the bone and to provide a better understanding of the basis of cancer cell survival within the bone microenvironment. The development of animal models that recapitulate more closely the human clinical scenario of prostate cancer will greatly benefit the generation of better therapies.