bluuebunny/crossref_metadata_2025 huggingface dataset:
Two‐stage Hydrolysis of Invasive Algal Feedstock for Ethanol FermentationF
Authors: Wang Xin , Liu Xianhua , Wang Guangyi
Published: December 2010

The overall goal of this work was to develop a saccharification method for the production of third generation biofuel (i.e. bioethanol) using feedstock of the invasive marine macroalga Gracilaria salicornia. Under optimum conditions (120 °C and 2% sulfuric acid for 30 min), dilute acid hydrolysis of the homogenized invasive plants yielded a low concentration of glucose (4.1 mM or 4.3 g glucose/kg fresh algal biomass). However, two‐stage hydrolysis of the homogenates (combination of dilute acid hydrolysis with enzymatic hydrolysis) produced 13.8 g of glucose from one kilogram of fresh algal feedstock. Batch fermentation analysis produced 79.1 g EtOH from one kilogram of dried invasive algal feedstock using the ethanologenic strain Escherichia coli KO11. Furthermore, ethanol production kinetics indicated that the invasive algal feedstock contained different types of sugar, including C5‐sugar. This study represents the first report on third generation biofuel production from invasive macroalgae, suggesting that there is great potential for the production of renewable energy using marine invasive biomass.
Short Form (SF‐36) Health Survey Measures Are Associated With Decreased Adherence Among Urban African Americans With Severe, Poorly Controlled Hypertension
Authors: Konerman Matthew , Weeks Kristina R. , Shands Jamille R. , Tilburt Jon C. , Dy Sydney , Bone Lee R. , Levine David M. , Young J. Hunter
Published: December 2010

The objective of this study was to determine whether an association exists between Short Form (SF‐36) Health Survey measures and nonadherence among urban African Americans with poorly controlled hypertension. A total of 158 African Americans were admitted to an urban academic hospital for severe, uncontrolled hypertension. The main outcome measure was self‐reported nonadherence to antihypertensive medications using a validated instrument. For every 10‐point increase in Physical Component Summary (PCS) score, an individual was almost two times more likely to report being nonadherent (odds ratio, 1.94; 95% confidence interval, 1.30–2.90; P<.01). A significant interaction (P=.05) was observed between the physical functioning and mental health subscales. Individuals with high physical functioning and low mental health scores displayed the lowest adherence rate. These results suggest that high physical functioning, especially if associated with poor mental health, increases the likelihood of nonadherence to antihypertensive regimens among urban African Americans. The SF‐36 may serve as an effective clinical tool that identifies patients at risk for nonadherence and, more importantly, may improve clinicians’ understanding of nonadherence, allowing for discussions about antihypertensive medications to be tailored to individual patients. J Clin Hypertens (Greenwich). 2011;13:385–390. ©2010 Wiley Periodicals, Inc.
Are Th17 Cells an Appropriate New Target in the Treatment of Rheumatoid Arthritis?
Authors: Kato Hiroshi , Fox David A.
Published: December 2010

Th17 cells play crucial roles not only in host defense but also in many human autoimmune diseases and corresponding animal models. Although many of the fundamental principles regarding Th17 biology have been rapidly elucidated in mice, there remain numerous controversies regarding the differentiation, plasticity, and pathogenicity of human Th17 cells. In this review, we consider these open questions in comparison to what has already been clarified in mice, and discuss the potential impact of discoveries related to the Th17 pathway on the development of new therapeutic strategies in Th17 driven autoimmune diseases, specifically rheumatoid arthritis. Clin Trans Sci 2010; Volume 3: 319–326
A Study of The Relationship between The Interleukin‐6 Gene and Obstructive Sleep Apnea
Authors: Larkin Emma K. , Patel Sanjay R. , Zhu Xiaofeng , Tracy Russell P. , Jenny Nancy S. , Reiner Alex P. , Walston Jeremy , Redline Susan
Published: December 2010

Because obstructive sleep apnea (OSA) is associated with increased levels of inflammatory cytokines, we examined the relationship between OSA and polymorphisms for interleukin‐6 (IL6). Six single nucleotide polymorphisms (SNPs) within IL6 were genotyped in 259 African Americans from the Cleveland Family Study with replication conducted in the Cardiovascular Health Study (n= 124). OSA was dichotomized into apnea hypopnea index (AHI) > 15, or on treatment versus absent: AHI < 5. Logistic regression was conducted, adjusting for age and sex in models with and without body mass index (BMI). SNP IL6–6021 was associated with a decreased risk of OSA after adjusting for BMI (Odds Ratio for T allele 0.24, 95%CI [0.09–0.67], p= 0.006, q= 0.07) under an additive model. This same allele was associated with increased BMI. The results from the replication sample were consistent in direction though not statistically significant (p= 0.23). The SNPs were studied in European‐ Americans, although, the minor allele frequency in IL6–6021 was too low (4%) for meaningful comparisons. A synonymous SNP within the IL6 coding region was protective of OSA in African Americans; with qualitatively similar findings observed in another cohort. This suggests that variants in IL6 may influence the risk of OSA in a pathway that is not explained by obesity. Clin Trans Sci 2010; Volume 3: 337–339
Enigmatic Role of Lipoprotein(a) in Cardiovascular Disease
Authors: Anuurad Erdembileg , Enkhmaa Byambaa , Berglund Lars
Published: December 2010

Lipoprotein (a), [Lp(a)] has many properties in common with low‐density lipoprotein, (LDL) but contains a unique protein apolipoprotein(a), linked to apolipoprotein B‐100 by a single disulfide bond. There is a substantial size heterogeneity of apo(a), and generally smaller apo(a) sizes tend to correspond to higher plasma Lp(a) levels, but this relation is far from linear, underscoring the importance to assess allele‐specific apo(a) levels. The presence of apo(a), a highly charged, carbohydrate‐rich, hydrophilic protein may obscure key features of the LDL moiety and offer opportunities for binding to vessel wall elements. Recently, interest in Lp(a) has increased because studies over the past decade have confirmed and more robustly demonstrated a risk factor role of Lp(a) for cardiovascular disease. In particular, levels of Lp(a) carried in particles with smaller size apo(a) isoforms are associated with coronary artery disease (CAD). Other studies suggest that proinflammatory conditions may modulate risk factor properties of Lp(a). Further, Lp(a) may act as a preferential acceptor for proinflammatory oxidized phospholipids transferred from tissues or from other lipoproteins. However, at present only a limited number of agents (e.g., nicotinic acid and estrogen) has proven efficacy in lowering Lp(a) levels. Although Lp(a) has not been definitely established as a cardiovascular risk factor and no guidelines presently recommend intervention, Lp(a)‐lowering therapy might offer benefits in subgroups of patients with high Lp(a) levels. Clin Trans Sci 2010; Volume 3: 327–332
Variants in Genes Involved in Functional Pathways Associated with Hypertension in African Americans
Authors: Martinez Cantarin Maria P. , Ertel Adam , Deloach Stephanie , Fortina Paolo , Scott Kathryn , Burns Trudy L. , Falkner Bonita
Published: December 2010

Essential hypertension (HBP) is a complex trait with a substantial heritable component. The purpose of this study was to determine if variants in the G‐protein coupled receptor Kinase‐4 (GRK4), nitric oxide synthase‐3 (NOS3), or angiotensin converting enzyme (ACE) genes are associated singly or through complex interactions, with HBP in African Americans aged 18–49 years. TaqMan Assays were used for genotyping the GRK4 and NOS3 variants. The ACE I/D variant was obtained by polymerase chain reaction and electrophoresis. Allelic association tests were performed for the five markers using PLINK. Logistic regression models were fitted to investigate associations between HBP status and the genetic markers. Multilocus analyses were also conducted. The study included 173 hypertensives and 239 normotensives, with stratification into obese and nonobese groups. The GRK4 A486V variant was negatively associated with HBP in the nonobese group (p= 0.048). The TT/CT genotype of GRK4 A486V was associated with decreased risk for HBP relative to the CC genotype after adjusting for age, sex, and body mass index (p= 0.028). Individuals having at least one NOS3 A allele and GRK4 R65L genotype GG had odds of HBP of 2.97 relative to GG homozygotes for NOS3 and GRK4 R65L. These results show very modest effects and do not fully replicate previous studies. Clin Trans Sci 2010; Volume 3: 279–286
SCN5A Rare Variants in Familial Dilated Cardiomyopathy Decrease Peak Sodium Current Depending on the Common Polymorphism H558R and Common Splice Variant Q1077del
Authors: Cheng Jianding , Morales Ana , Siegfried Jill D. , Li Duanxiang , Norton Nadine , Song Junyao , Gonzalez‐Quintana Jorge , Makielski Jonathan C. , Hershberger Ray E.
Published: December 2010

Obtaining functional data with newly identified rare variants increases certainty that the variant identified is relevant for dilated cardiomyopathy (DCM) causation. Two novel SCN5A rare variants, R222Q and I1835T, segregated with DCM in two families with affected individuals homozygous or heterozygous for the common SCN5A polymorphism H558R. cDNAs with each rare variant were constructed in the common Q1077del or Q1077 splice variant backgrounds with and without the H558R polymorphism and expressed in HEK293 cells. Sodium current (INa) was studied for each using whole‐cell voltage clamp. In the Q1077del background INa densities of R222Q and I1835T were not different from wild type, but the combined variants of R222Q/H558R, I1835T/H558R caused approximately 35% and approximately 30% reduction, respectively, and each showed slower recovery from inactivation. In the Q1077del background R222Q and R222Q/H558R also exhibited a significant negative shift in both activation and inactivation while I1835T/H558R showed a significant negative shift in inactivation that tended to decrease window current. In contrast, expression in the Q1077 background showed no changes in peak INa densities, decay, or recovery from inactivation for R222Q/H558R and I1835T/H558R. We conclude that the biophysical findings, dependent upon common SCN5A variants, provide further evidence that these novel SCN5A rare variants are relevant for DCM. Clin Trans Sci 2010; Volume 3: 287–294
Computing Cutter Engagement Values in Milling Tessellated Free-Form Surfaces
Authors: Yao Zhiyang , Joneja Ajay
Published: December 2010

High speed milling (HSM) has great potential use in die/mold cutting, but traditional machining plans do exploit HSM capabilities effectively. An important consideration in HSM is to limit cutting force variations, and one way to do so is to reduce cutter-workpiece engagement (CWE) variations. CWE is measured as the area of the tool instantaneously engaged with the part. Estimating CWE as a function of the tool path requires repeated, expensive computations. This paper develops algorithms for a discretized computational model to make CWE computations for arbitrary shaped parts.
Recognition of Freeform Surface Machining Features
Authors: Wang Jun , Wang Zhigang , Zhu Weidong , Ji Yingfeng
Published: December 2010

This paper describes a method of machining feature recognition from a freeform surface based on the relationship between unique machining patches and critical points on a component’s surface. The method uses Morse theory to extract critical surface points by defining a scalar function on the freeform surface. Features are defined by region growing between the critical points using a tool path generation algorithm. Several examples demonstrate the efficiency of this approach. The recognized machining features can be directly utilized in a variety of downstream computer aided design/computer aided manufacturing (CAM) applications, such as the automated machining process planning.
Fabrication and Energy Harvesting Measurements of Vibrating MEMS Piezoelectric Benders
Authors: Mo Changki , Knight Ryan R. , Frederick Amanda A. , Clark William W.
Published: December 2010

In this paper, a study is presented in which piezoelectric microbenders were fabricated and tested to demonstrate energy generating performance. Trapezoidal and diagonal (with respect to the substrate crystal directions) unimorph PZT cantilever benders with interdigitated electrode patterns were utilized. The interdigitated design is beneficial for microenergy harvesting devices because it utilizes the d33 mode, which can generate higher voltage than the d31 mode design. It can also eliminate the bottom electrode by only using an interdigitated top electrode, which facilitates fabrication, as opposed to the d31 mode design that requires both top and bottom electrodes. The micro-electromechanical system (MEMS) benders fabricated in this study consist of layers of SiO2/SiNx/ZrO2/PZT and Au/Cr interdigitated electrode on the top. The experimental results indicate that the fundamental frequencies of the microbenders are about 9.1 kHz for the trapezoidal bender and 18.48 kHz for the diagonal bender. The microtrapezoidal bender can generate power of approximately 1.4 μW into a 680 kΩ resistive load at the resonant frequency. The diagonal bender can generate power of about 18.2 μW into a 100 kΩ resistive load at the resonant frequency.
The Genetic Landscape of the Childhood Cancer Medulloblastoma
Authors: Parsons D. Williams , Li Meng , Zhang Xiaosong , Jones Siân , Leary Rebecca J. , Lin Jimmy Cheng-Ho , Boca Simina M. , Carter Hannah , Samayoa Josue , Bettegowda Chetan , Gallia Gary L. , Jallo George I. , Binder Zev A. , Nikolsky Yuri , Hartigan James , Smith Doug R. , Gerhard Daniela S. , Fults Daniel W. , VandenBerg Scott , Berger Mitchel S. , Marie Suely Kazue Nagahashi , Shinjo Sueli Mieko Oba , Clara Carlos , Phillips Peter C. , Minturn Jane E. , Biegel Jaclyn A. , Judkins Alexander R. , Resnick Adam C. , Storm Phillip B. , Curran Tom , He Yiping , Rasheed B. Ahmed , Friedman Henry S. , Keir Stephen T. , McLendon Roger , Northcott Paul A. , Taylor Michael D. , Burger Peter C. , Riggins Gregory J. , Karchin Rachel , Parmigiani Giovanni , Bigner Darell D. , Yan Hai , Papadopoulos Nick , Vogelstein Bert , Kinzler Kenneth W. , Velculescu Victor E.
Published: December 2010

Genomic analysis of a childhood cancer reveals markedly fewer mutations than what is typically seen in adult cancers.
Increasing deaths involving oxycodone, Victoria, Australia, 2000–09
Authors: Rintoul Angela C , Dobbin Malcolm D H , Drummer Olaf H , Ozanne-Smith Joan
Published: December 2010

Objective

In light of an emerging epidemic identified in the United States and Canada, to identify trends in fatal drug toxicity involving oxycodone and the demographic characteristics and indicators of socioeconomic disadvantage of the deceased.

Study design

Population-based observational study in Victoria, Australia.

Population

Decedents whose death was reported to the Victorian Coroner between 2000 and 2009 and where oxycodone was detected.

Main outcome measures

Association between supply of oxycodone and deaths. Demographic characteristics of decedents. Rate ratios of the rural or metropolitan location and socioeconomic indicators of disadvantage of the deceased.

Results

Supply to Victoria has increased nine-fold from 7.5 mg per capita in 2000 to 67.5 mg per capita in 2009. Detection of oxycodone in deaths reported to the Victorian Coroner has increased from 4 (0.08/100 000 population) in 2000 to 97 (1.78/100 000 population) in 2009—a 21-fold increase in deaths. Of the 320 cases described, 53.8% (172) were the result of drug toxicity. Of these, 52.3% were unintentional and 19.8% intentional self-harm; the remaining 27.9% are either still under investigation by the coroner or intent is unknown. Drug toxicity deaths were overrepresented in both rural areas and areas indexed with high levels of disadvantage.

Conclusions

The substantial increase in the number of deaths involving oxycodone is strongly and significantly associated with the increase in supply. Most drug toxicity deaths involving oxycodone were unintentional. This newly identified trend in fatalities in Victoria supports concerns that a pattern of increasing deaths involving oxycodone is emerging globally.
Cardiac autonomic dysfunction from occupational exposure to polycyclic aromatic hydrocarbons
Authors: Lee Mi-Sun , Magari Shannon , Christiani David C
Published: December 2010

Objectives

Exposure to polycyclic aromatic hydrocarbons (PAHs) has been associated with cardiopulmonary mortality and cardiovascular events. This study investigated the association between a biological marker of PAH exposure, assessed by urinary 1-hydroxypyrene (1-OHP), and heart-rate variability in an occupational cohort of boilermakers.

Methods

Continuous 24 h monitoring of the ambulatory electrocardiogram (ECG) and pre- and postshift urinary 1-OHP were repeated over extended periods of the work week. Mixed-effects models were fitted for the 5 min SD of normal-to-normal intervals (SDNN) in relation to urinary 1-OHP levels pre- and postworkshift on the day they wore the monitor, controlling for potential confounders.

Results

The authors found a significant decrease in 5 min SDNN during work of −13.6% (95% CI −17.2% to −9.8%) per SD (0.53 μg/g creatinine) increase in the next-morning preshift 1-OHP levels. The magnitude of reduction in 5 min SDNN was largest during the late night period after work and increased with each SD (0.46 μg/g creatinine) increase in postshift 1-OHP levels.

Conclusion

This is the first report providing evidence that occupational exposure to PAHs is associated with altered cardiac autonomic function. Acute exposure to PAHs may be an important predictor of cardiovascular disease risk in the work environment.
Tungsten in Archean banded iron formation of the former Sherman and Adams mines, Ontario: possible mineralization processes
Authors: Bowins Robert , Crocket James
Published: December 2010

Anomalous tungsten occurs in Archean banded iron formation from the previous Sherman and Adams mines, Ontario. In Sherman samples from three open pits and one drill core site, with one exception, anomalous tungsten occurred only in the Sherman North pit. Adams mine samples from three pits carried anomalous tungsten in samples of chlorite-rich silicate facies. Statistical evaluation showed that ≥10 ppm tungsten was anomalous with respect to the entire data set. The implications of restricted tungsten distribution, as seen in Sherman occurrences, were evaluated with respect to tungsten mineralization processes. Scenarios considered involve syngenetic, metamorphic, and magmatic-hydrothermal processes. Thermal constraints provided by iron-bearing silicate assemblages and oxygen isotopes attest to contact metamorphism as a potential mechanism for tungsten redistribution within iron formation. However, tungsten of magmatic-hydrothermal origin emplaced as an epigenetic component is considered the essential mineralization process.
A new species of Sorbinichthys (Teleostei: Clupeomorpha: Ellimmichthyiformes) from the Late Cretaceous of Morocco
Authors: Murray Alison M. , Wilson Mark V.H.
Published: December 2010

A new species of ellimmichthyiform fish, represented by three specimens, has been recovered from deposits of the Akrabou Formation of Morocco. The new species is described in the existing genus Sorbinichthys , family Sorbinichthyidae, as Sorbinichthys africanus , sp. nov., closely related to the type species Sorbinichthys elusivo . The Ellimmichthyiformes is an extinct order of clupeomorph fishes that includes both freshwater and marine species ranging from the Early Cretaceous through the Eocene. Sorbinichthys elusivo is known from Cenomanian deposits of the eastern Mediterranean Tethys (Lebanon), whereas the new species is possibly early Turonian but more probably late Cenomanian in age, from the western Tethys (eastern Morocco). At lower taxonomic levels, the assemblage from the Akrabou Formation has a primarily Tethyan composition, exemplified by the genus Sorbinichthys, whereas supra-generic taxa found there include groups with trans-Atlantic (e.g., Sorbinichthyidae, Macrosemiidae) or near-cosmopolitan (e.g., Paraclupeidae) distributions.
Cyclic sedimentation in the Eocene Allenby Formation of south-central British Columbia and the origin of the Princeton Chert fossil beds
Authors: Mustoe George E.
Published: December 2010

Extensive deposits of Eocene conglomerate, sandstone, shale, and sub-bituminous coal occur within a half-graben at Princeton, British Columbia. These strata comprise ∼2000 m of fluvial sediment interbedded with tephra and volcanic flows. Near the southeast margin of the basin, ∼200 m of rhythmically bedded strata are exposed along the Similkameen River. Cyclic deposition resulted from repeated episodes of hydrologic and topographic change related to seismic activity along the Boundary Fault on the east flank of the Princeton Basin, where Allenby Formation sediments are juxtaposed against metamorphic and metavolcanic rocks of the Upper Triassic Nicola Group. Interbedded carbonaceous shale and tuffaceous sandstone record influxes of distal lahar deposits into a lowland swamp. Coal–breccia transitions originated when debris flows along the scarp carried volcanic debris into adjacent wetlands. Coal–chert rhythmites are inferred to be evidence of hydrologic changes associated with floodplain tilt events that caused lowland to repeatedly alternate between a stagnant pond (“fen”) and a stream-fed lake. During fen stages, peat was silicified in situ from percolation of groundwater carrying silica dissolved from underlying tuffaceous beds. Episodic influxes of stream flow reduced dissolved silica concentrations and caused increases in dissolved oxygen levels. These geochemical changes caused organic matter that accumulated during these conditions of open water circulation to remain unsilicified and susceptible to partial maceration. Diagenesis eventually converted these deposits to alternating beds of sub-bituminous coal intercalated with chert horizons.
Measurement of dynamic properties of stiff specimens using ultrasonic waves
Authors: Khan Zahid , Cascante Giovanni , El Naggar M. Hesham
Published: December 2010

The measurement of low-strain properties (wave velocity and damping ratio) of geomaterials is affected by equipment-generated delays, coupling of transducers, and wave reflections. This study presents a new technique to measure ultrasonic properties of stiff specimens accurately. Compressional-wave velocities in cylindrical rods of different lengths and materials were measured using different ultrasonic equipment. The error induced by different equipment was below 1% after the measurements were corrected by the equipment time delay. Shear-wave velocities of different materials were measured using ultrasonic transducers (frequency < 1 MHz) and a resonant column device (frequency < 200 Hz). The difference in shear-wave velocities was less than 4%, and the measured values are in agreement with published results for all tested materials. A new methodology based on the first two reflections of the main pulse has been developed to measure the damping ratio of stiff specimens using ultrasonic equipment. The ultrasonic measurements of the damping ratio compare well with resonant column results. A more reliable determination of the dynamic Poisson’s ratio of a cemented sand was achieved using corrected ultrasonic-wave velocities.
Development and evaluation of an automation algorithm for a time-domain reflectometry bridge scour monitoring system
Authors: Yu X. B. , Yu X.
Published: December 2010

Bridge scour is a major threat to the safety of bridges. There is a high risk of scour-induced damage due to the catastrophic nature of bridge foundation failure. The development of an innovative bridge scour monitoring system is a pressing task for the research community. Such a system needs to be fieldworthy, which is a characteristic assessed in terms of accuracy, ruggedness, and automation. Among these criteria, an automatic signal analysis algorithm is generally a prerequisite for deploying a long-term field monitoring program. This paper describes the development and validation of an algorithm for a scour monitoring system based on the principles of guided radar: time-domain reflectometry (TDR). This algorithm is based on the extension of the classic dielectric mixing model to layered systems. The performance of this algorithm is evaluated using experiments designed to simulate different field scour conditions. These include different types of sediments and the variation of river conditions (i.e., salinity of river water, air entrainment, and amount of suspended sediments). The experiment results indicate that the developed analyses algorithm is robust and accurate for scour-depth estimation under these investigated conditions.
Laboratory study on radial consolidation and deformation in clay reinforced with stone columns
Authors: Cimentada Ana , Da Costa Almudena , Cañizal Jorge , Sagaseta César
Published: December 2010

A series of laboratory tests was performed to study the deformation and radial consolidation around end-bearing (fully penetrating) stone columns. For this purpose, the behaviour of a horizontal slice of a unit cell representative of a column and the surrounding soil was analysed. The tests were carried out in a Rowe–Barden large oedometric cell that was instrumented to measure vertical stresses and pore pressures at several distances from the axis. Two column geometries were tested, with cell-to-column diameter ratios of N = 3 and 4. The most important findings of this work were the rate of pore pressure dissipation, the vertical strain reduction due to the presence of the column of approximately 25% for N = 4 and 35% for N = 3, and the load transfer to the column related to the stiffness ratio between the column and soil resulting in incremental stress concentration factors in the range 2.5 to 9.2. Results were compared with theoretical solutions that are commonly used for the study of stone column behaviour.
Practical reliability analysis of slope stability by advanced Monte Carlo simulations in a spreadsheet
Authors: Wang Yu , Cao Zijun , Au Siu-Kui
Published: December 2010

This paper develops a Monte Carlo simulation (MCS)-based reliability analysis approach for slope stability problems and utilizes an advanced MCS method called “subset simulation” for improving efficiency and resolution of the MCS at relatively small probability levels. Reliability analysis is operationally decoupled from deterministic slope stability analysis and implemented using a commonly available spreadsheet software, Microsoft Excel. The reliability analysis spreadsheet package is validated through comparison with other reliability analysis methods and commercial software. The spreadsheet package is then used to explore the effect of spatial variability of the soil properties and critical slip surface. It is found that, when spatial variability of soil properties is ignored by assuming perfect correlation, the variance of the factor of safety (FS) is overestimated, which may result in either over (conservative) or under (unconservative) estimation of the probability of failure (Pf = P(FS < 1)). When the spatial variability of soil properties is considered, the critical slip surface varies spatially and such spatial variability should be properly accounted for. Otherwise, the probability of failure can be significantly underestimated and unconservative.
Landslide hazard assessment of the 2008 Wenchuan earthquake: a case study in Beichuan area
Authors: Tang Chuan , Zhu Jing , Qi Xin
Published: December 2010

The Wenchuan earthquake (magnitude Ms = 8.0) of 12 May 2008 triggered widespread and large-scale landslides over an area of about 50 000 km2. A study was undertaken to determine the primary factors associated with seismic landslide occurrence. An index-based approach used to assess earthquake-triggered landslide hazard in the central part of the Wenchuan earthquake area affected is described. Slope gradient, relief amplitude, lithology, bedding–slope relations, fault proximity, stream proximity, and antecedent rainfall are recognized as factors that may have had an important influence on landslide occurrence. The assessment of the influence of each of these factors is presented through use of a series of maps showing areas of low, moderate, high, and very high landslide hazard. Areas identified as having “very high and high landslide hazard” were located along the earthquake-source fault and along both banks of the Jian River. The role of rainfall is very significant for future landslide occurrence in the earthquake area. The results of this study will assist decision makers in the selection of safe sites during the reconstruction process. The maps can also be used for landslide risk management in the study area.
HOLOGRAPHIC-LIKE MODELS AS A FIVE-DIMENSIONAL REWRITING OF LARGE-Nc QCD
Authors: AFONIN S. S.
Published: December 2010

The AdS/QCD models are known to be closely related to the QCD sum rules in the large-Nc (called also planar) limit. Rewriting the theory of infinite tower of free stable mesons expected in the large-Nc QCD as a five-dimensional theory, we scrutinize to what extend the bottom-up holographic models may be viewed as an alternative language expressing the phenomenology of planar QCD sum rules. It is found that many features of AdS/QCD models can be thereby obtained without invoking prescriptions from the original AdS/CFT correspondence. Under some assumptions, all possibilities leading to simple Regge trajectories are classified, and it is argued that the most phenomenologically consistent model is the one called "soft wall model" in the holographic approach, with a preference to the positive-sign dilaton background.
SLIT-WAVE MODEL FOR BAND STRUCTURES IN SOLID STATE PHYSICS
Authors: TAHIRBEGI I. B. , MIR M.
Published: December 2010

The reason behind the entire development in silicon technology was band models in solid state physics. However, the theories postulated in order to give response to this phenomenon do not explain all kinds of materials. In a bid to overcome this limitation, we approach the problem from another point of view. In this work, the wave properties of the electrons from the external orbitals of the atoms and its diffraction patterns through the lattice structure of the material have been used to explain the band structure of metals, semiconductor and insulators. In order to probe this hypothesis, a simulation has been used and according to the relation between the lattice constant and the atomic diameter, the splitting of the bands have been observed for different kind of materials, showing a strong correlation between the simulation and the experimental results.
TIGHT-BINDING PARAMETERS FOR GRAPHENE
Authors: KUNDU RUPALI
Published: December 2010

In this article, we have reproduced the tight-binding π band dispersion of graphene including up to third nearest-neighbors and also calculated the density of states of π band within the same model. The aim was to find out a set of parameters descending in order as distance towards third nearest-neighbor increases compared to that of first and second nearest-neighbors with respect to an atom at the origin. Here we have discussed two such sets of parameters by comparing the results with first principle band structure calculation.1
RANDOM DISPERSAL IN A PREDATOR-PREY-PARASITE SYSTEM
Authors: JANG SOPHIA R.-J. , BAGLAMA JAMES , WU LI
Published: December 2010

We propose predator-prey-parasite models to study the effects of parasites upon the predator-prey interaction. There are two parameters that are used to model the effectiveness of the infected prey and infected predator. For the spatial homogeneous system, the asymptotic dynamics depend on the reproductive number of the parasite. The parasite can persist in the population if this reproductive number is larger than one. Numerical simulations suggest that less competitiveness of the infected predator can make the predator-prey interaction less stable. The dynamics may move from coexisting steady state to oscillations. For the spatial heterogeneous system, diffusion may destabilize the homogeneous interior steady state for a particular set of diffusion coefficients. However, both systems do not exhibit complicated dynamical behavior.
AN INDIVIDUAL-BASED NETWORKED MODEL WITH PROBABILISTIC RELOCATION OF PEOPLE AND VECTORS AMONG LOCATIONS FOR SIMULATING THE SPREAD OF INFECTIOUS DISEASES
Authors: VITTORINI PIERPAOLO , VILLANI ANTONELLA , DI ORIO FERDINANDO
Published: December 2010

Eubank et al. propose to study the spread of infectious disease in large urban environments using dynamic bipartite graph modeling the contact pattern, and computer simulations to estimate the evolution of epidemics. Eubank's approach requires a detailed knowledge of individuals, daily routine. In our work we would generalize the model by introducing a stochastic relocation of people and vectors among locations, thanks to distribution functions. Computer simulations are used to produce the infection and death processes. Finally, the paper presents two case studies. The first case study emphasizes the effect of using probabilistic relocation in a particular social network, while the second discusses how vector-borne diseases could be taken into account.
SWITCHING FEEDING AMONG SOUND AND INFECTED PREY IN ECOEPIDEMIC SYSTEMS
Authors: HOTOPP INES S. , MALCHOW HORST , VENTURINO EZIO
Published: December 2010

We investigate the switching feeding behavior of predators in the context of one single prey population, which is disease affected. We consider the case of hunting indiscriminately both types of prey, when the infected prey causes no harm to their predators, but assume also in another model that feeding on the infected individuals has a negative return on the predators. Some counterintuitive results are obtained and discussed.
Enteric oxalate elimination is induced and oxalate is normalized in a mouse model of primary hyperoxaluria following intestinal colonization withOxalobacter
Authors: Hatch Marguerite , Gjymishka Altin , Salido Eduardo C. , Allison Milton J. , Freel Robert W.
Published: December 2010

Oxalobacter colonization of rat intestine was previously shown to promote enteric oxalate secretion and elimination, leading to significant reductions in urinary oxalate excretion (Hatch et al. Kidney Int 69: 691–698, 2006). The main goal of the present study, using a mouse model of primary hyperoxaluria type 1 (PH1), was to test the hypothesis that colonization of the mouse gut by Oxalobacter formigenes could enhance enteric oxalate secretion and effectively reduce the hyperoxaluria associated with this genetic disease. Wild-type (WT) mice and mice deficient in liver alanine-glyoxylate aminotransferase (Agxt) exhibiting hyperoxalemia and hyperoxaluria were used in these studies. We compared the unidirectional and net fluxes of oxalate across isolated, short-circuited large intestine of artificially colonized and noncolonized mice. In addition, plasma and urinary oxalate was determined. Our results demonstrate that the cecum and distal colon contribute significantly to enteric oxalate excretion in Oxalobacter-colonized Agxt and WT mice. In colonized Agxt mice, urinary oxalate excretion was reduced 50% (to within the normal range observed for WT mice). Moreover, plasma oxalate concentrations in Agxt mice were also normalized (reduced 50%). Colonization of WT mice was also associated with marked (up to 95%) reductions in urinary oxalate excretion. We conclude that segment-specific effects of Oxalobacter on intestinal oxalate transport in the PH1 mouse model are associated with a normalization of plasma oxalate and urinary oxalate excretion in otherwise hyperoxalemic and hyperoxaluric animals.
Why is the subendocardium more vulnerable to ischemia? A new paradigm
Authors: Algranati Dotan , Kassab Ghassan S. , Lanir Yoram
Published: December 2010

Myocardial ischemia is transmurally heterogeneous where the subendocardium is at higher risk. Stenosis induces reduced perfusion pressure, blood flow redistribution away from the subendocardium, and consequent subendocardial vulnerability. We propose that the flow redistribution stems from the higher compliance of the subendocardial vasculature. This new paradigm was tested using network flow simulation based on measured coronary anatomy, vessel flow and mechanics, and myocardium-vessel interactions. Flow redistribution was quantified by the relative change in the subendocardial-to-subepicardial perfusion ratio under a 60-mmHg perfusion pressure reduction. Myocardial contraction was found to induce the following: 1) more compressive loading and subsequent lower transvascular pressure in deeper vessels, 2) consequent higher compliance of the subendocardial vasculature, and 3) substantial flow redistribution, i.e., a 20% drop in the subendocardial-to-subepicardial flow ratio under the prescribed reduction in perfusion pressure. This flow redistribution was found to occur primarily because the vessel compliance is nonlinear (pressure dependent). The observed thinner subendocardial vessel walls were predicted to induce a higher compliance of the subendocardial vasculature and greater flow redistribution. Subendocardial perfusion was predicted to improve with a reduction of either heart rate or left ventricular pressure under low perfusion pressure. In conclusion, subendocardial vulnerability to a acute reduction in perfusion pressure stems primarily from differences in vascular compliance induced by transmural differences in both extravascular loading and vessel wall thickness. Subendocardial ischemia can be improved by a reduction of heart rate and left ventricular pressure.
Stanozolol treatment decreases the mitochondrial ROS generation and oxidative stress induced by acute exercise in rat skeletal muscle
Authors: Saborido Ana , Naudí Alba , Portero-Otín Manuel , Pamplona Reinald , Megías Alicia
Published: December 2010

Anabolic androgenic steroids are used in the sport context to enhance muscle mass and strength and to increase muscle fatigue resistance. Since muscle fatigue has been related to oxidative stress caused by an exercise-linked reactive oxygen species (ROS) production, we investigated the potential effects of a treatment with the anabolic androgenic steroid stanozolol against oxidative damage induced on rat skeletal muscle mitochondria by an acute bout of exhaustive exercise. Mitochondrial ROS generation with complex I- and complex II-linked substrates was increased in exercised control rats, whereas it remained unchanged in the steroid-treated animals. Stanozolol treatment markedly reduced the extent of exercise-induced oxidative damage to mitochondrial proteins, as indicated by the lower levels of the specific markers of protein oxidation, glycoxidation, and lipoxidation, and the preservation of the activity of the superoxide-sensitive enzyme aconitase. This effect was not due to an enhancement of antioxidant enzyme activities. Acute exercise provoked changes in mitochondrial membrane fatty acid composition characterized by an increased content in docosahexaenoic acid. In contrast, the postexercise mitochondrial fatty acid composition was not altered in stanozolol-treated rats. Our results suggest that stanozolol protects against acute exercise-induced oxidative stress by reducing mitochondrial ROS production, in association with a preservation of mitochondrial membrane properties.
Emergence of matched airway and vascular trees from fractal rules
Authors: Glenny Robb W.
Published: December 2010

The bronchial, arterial, and venous trees of the lung are complex interwoven structures. Their geometries are created during fetal development through common processes of branching morphogenesis. Insights from fractal geometry suggest that these extensively arborizing trees may be created through simple recursive rules. Mathematical models of Turing have demonstrated how only a few proteins could interact to direct this branching morphogenesis. Development of the airway and vascular trees could, therefore, be considered an example of emergent behavior as complex structures are created from the interaction of only a few processes. However, unlike inanimate emergent structures, the geometries of the airway and vascular trees are highly stereotyped. This review will integrate the concepts of emergence, fractals, and evolution to demonstrate how the complex branching geometries of the airway and vascular trees are ideally suited for gas exchange in the lung. The review will also speculate on how the heterogeneity of blood flow and ventilation created by the vascular and airway trees is overcome through their coordinated construction during fetal development.
Blue light from light-emitting diodes elicits a dose-dependent suppression of melatonin in humans
Authors: West Kathleen E. , Jablonski Michael R. , Warfield Benjamin , Cecil Kate S. , James Mary , Ayers Melissa A. , Maida James , Bowen Charles , Sliney David H. , Rollag Mark D. , Hanifin John P. , Brainard George C.
Published: December 2010

Light suppresses melatonin in humans, with the strongest response occurring in the short-wavelength portion of the spectrum between 446 and 477 nm that appears blue. Blue monochromatic light has also been shown to be more effective than longer-wavelength light for enhancing alertness. Disturbed circadian rhythms and sleep loss have been described as risk factors for astronauts and NASA ground control workers, as well as civilians. Such disturbances can result in impaired alertness and diminished performance. Prior to exposing subjects to short-wavelength light from light-emitting diodes (LEDs) (peak λ = 469 nm; ½ peak bandwidth = 26 nm), the ocular safety exposure to the blue LED light was confirmed by an independent hazard analysis using the American Conference of Governmental Industrial Hygienists exposure limits. Subsequently, a fluence-response curve was developed for plasma melatonin suppression in healthy subjects ( n = 8; mean age of 23.9 ± 0.5 years) exposed to a range of irradiances of blue LED light. Subjects with freely reactive pupils were exposed to light between 2:00 and 3:30 AM. Blood samples were collected before and after light exposures and quantified for melatonin. The results demonstrate that increasing irradiances of narrowband blue-appearing light can elicit increasing plasma melatonin suppression in healthy subjects ( P < 0.0001). The data were fit to a sigmoidal fluence-response curve ( R2= 0.99; ED50= 14.19 μW/cm2). A comparison of mean melatonin suppression with 40 μW/cm2from 4,000 K broadband white fluorescent light, currently used in most general lighting fixtures, suggests that narrow bandwidth blue LED light may be stronger than 4,000 K white fluorescent light for suppressing melatonin.
Making the Investigational Oncology Pipeline More Efficient and Effective: Are We Headed in the Right Direction?
Authors: LoRusso Patricia M. , Anderson Aparna B. , Boerner Scott A. , Averbuch Steven D.
Published: December 2010

Advances in our knowledge of the molecular mechanisms involved in cancer biology have contributed to an increase in novel target-specific oncology therapeutics. Unfortunately, clinical development of new drugs is an expensive and slow process, and the patient and financial resources needed to study the vast number of potential therapies are limited, requiring novel approaches to clinical trial design and patient recruitment. In addition, traditional efficacy endpoints may not be adequate to fully determine the therapeutic worth of the new classes of targeted agents. In this new era of drug development, it has become increasingly clear that new clinical trial design paradigms that examine nontraditional endpoints have become necessary to assist in prioritizing the development of the most promising agents. It is also vital that individual patient management be considered, and the subpopulations of patients most likely to derive benefit or experience harm from a new therapy be identified as early as possible. Phase I and II clinical trials allow investigators doing clinical research the opportunity to define these critical endpoints and subpopulations early on, before conducting large-scale randomized phase III clinical trials, which require an abundance of financial and patient resources. Clin Cancer Res; 16(24); 5956–62. ©2010 AACR.
The Notch Target Hes1 Directly Modulates Gli1 Expression and Hedgehog Signaling: A Potential Mechanism of Therapeutic Resistance
Authors: Schreck Karisa C. , Taylor Pete , Marchionni Luigi , Gopalakrishnan Vidya , Bar Eli E. , Gaiano Nicholas , Eberhart Charles G.
Published: December 2010

Purpose: Multiple developmental pathways including Notch, Hedgehog, and Wnt are active in malignant brain tumors such as medulloblastoma and glioblastoma (GBM). This raises the possibility that tumors might compensate for therapy directed against one pathway by upregulating a different one. We investigated whether brain tumors show resistance to therapies against Notch, and whether targeting multiple pathways simultaneously would kill brain tumor cells more effectively than monotherapy.

Experimental Design: We used GBM neurosphere lines to investigate the effects of a gamma-secretase inhibitor (MRK-003) on tumor growth, and chromatin immunoprecipitation to study the regulation of other genes by Notch targets. We also evaluated the effect of combined therapy with a Hedgehog inhibitor (cyclopamine) in GBM and medulloblastoma lines, and in primary human GBM cultures.

Results: GBM cells are at least partially resistant to long-term MRK-003 treatment, despite ongoing Notch pathway suppression, and show concomitant upregulation of Wnt and Hedgehog activity. The Notch target Hes1, a repressive transcription factor, bound the Gli1 first intron, and may inhibit its expression. Similar results were observed in a melanoma-derived cell line. Targeting Notch and Hedgehog simultaneously induced apoptosis, decreased cell growth, and inhibited colony-forming ability more dramatically than monotherapy. Low-passage neurospheres isolated from freshly resected human GBMs were also highly susceptible to coinhibition of the two pathways, indicating that targeting multiple developmental pathways can be more effective than monotherapy at eliminating GBM-derived cells.

Conclusions: Notch may directly suppress Hedgehog via Hes1 mediated inhibition of Gli1 transcription, and targeting both pathways simultaneously may be more effective at eliminating GBMs cells. Clin Cancer Res; 16(24); 6060–70. ©2010 AACR.
Value and Cancer Care: Toward an Equitable Future
Authors: Schnipper Lowell E. , Meropol Neal J. , Brock Dan W.
Published: December 2010

Health care expenses in the United States are increasing inexorably. At the current rate of growth, it is anticipated that 20% of the gross national product will consist of health-related expenditures within the next decade. Cancer is the second leading cause of death in the United States, and it is increasing in prevalence because of the aging of the population and the limited number of successful prevention strategies. As the biological characteristics of cancer come into sharper focus, targeted therapies are being developed that offer the promise of increased clinical benefit with fewer toxicities than are associated with conventional treatment. Although spectacular successes are infrequent with this approach, to date, the majority of targeted therapies are modestly effective at best, and extremely costly. This observation suggests that a broadly acceptable definition of value in a cancer therapeutic agent is not at hand, but is sorely needed from the vantage points of the patient and society. A corollary issue of enormous import is how to equitably distribute the health care dollar in the service of achieving the greatest good for the greatest number. Although cancer is responsible for only 5% of the health care budget, its cost is increasing and it can be viewed as paradigmatic when contemplating the problem of equity in health care. Here, a number of concepts are discussed that focus on this goal and its implications for the cancer patient and society at large. Clin Cancer Res; 16(24); 6004–8. ©2010 AACR.