bluuebunny/crossref_metadata_2025 huggingface dataset:
Modelling changes in the distribution of the critical food resources of a specialist folivore in response to climate change
Authors: Adams‐Hosking Christine , McAlpine Clive , Rhodes Jonathan R. , Grantham Hedley S. , Moss Patrick T.
Published: February 2012

Aim An important consideration when planning to conserve a species under climate change is to understand how the distribution of its food resources may also contract or shift under those same climatic conditions. Here, we use a case study to demonstrate a spatial conservation planning approach to inform decisions about where, under climate change, to protect and restore critical food and habitat resources for highly specialized species.

Location Eastern Australia.

Methods We developed fitted models for the koala (Phascolarctos cinereus) and five of its key eucalypt food trees using the maximum entropy algorithm available in Maxent. We then projected these models using a range of IPCC A1FI climate change scenarios and identified areas with a higher probability of occurrence. We calculated where the koala and its food trees may co‐occur under future climate change.

Results The koala and its food trees experienced significant range contractions as climate change progressed, sometimes to regions outside their current distributions. The inland speciesEucalyptus camaldulensisandEucalyptus coolabahcontracted from the more arid interior, which is outside the koala range, but persisted in the eastern regions of the koala’s range, whileEucalyptus viminalis,Eucalyptus populneaandEucalyptus tereticorniscontracted eastwards and southwards, with a fragmented distribution. The highest probabilities of overlap between koalas and their food trees were identified in fragmented coastal and southern regions of the koala’s current range.

Main conclusions The application of a robust species distribution modelling decision support tool identified important changes, under climate change, in the distribution of a specialist species and its key food trees. These distributions did not change in complete synergy and therefore areas of overlap varied, depending on the food tree species modelled. This is of particular importance in a conservation planning context, when considering targeted protection and restoration of species‐specific habitat resources.
Computer‐assisted assessment of obsessive‐compulsive disorder in young people: a preliminary evaluation of the Development and Well‐Being Assessment
Authors: Krebs Georgina , Liang Holan , Hilton Kristina , Macdiarmid Fiona , Heyman Isobel
Published: February 2012

Background

Paediatric obsessive‐compulsive disorder (OCD) often goes undetected, delaying access to evidence‐based treatment. This study aimed to assess the utility of a computerised diagnostic tool, the Development and Well‐Being Assessment (DAWBA), in detecting OCD and comorbidity in youth.

Method

A total of 51 young people referred to a specialist OCD service between September 2007 and July 2008 completed the DAWBA prior to clinical assessment. Computer‐rated and clinician‐rated DAWBA diagnoses were compared with those assigned by the specialist clinic.

Results

The computer‐rated and clinician‐rated DAWBA correctly classified OCD in 71% and 77% of cases respectively. Compared to consensus diagnoses, the computer‐rated DAWBA tended to over‐diagnose comorbidity, while the clinician‐rated DAWBA diagnoses of comorbidity corresponded well with the consensus.

Conclusions

The DAWBA has potential value in detecting OCD as well as comorbid disorders, and could be a cost‐effective method for diagnosing OCD and related problems.
Effects of sertindole on cognition in clozapine‐treated schizophrenia patients
Authors: Nielsen R. E. , Levander S. , Thode D. , Nielsen J.
Published: February 2012

Nielsen RE, Levander S, Thode D, Nielsen J. Effects of sertindole on cognition in clozapine‐treated schizophrenia patients.

Objective:  To assess the cognitive effects of sertindole augmentation in clozapine‐treated patients diagnosed with schizophrenia. Cognition is secondary outcome of the trial.

Method:  A 12‐week, double‐blinded, randomized, placebo‐controlled, augmentation study of patients treated with clozapine. Participants were randomized 1:1 to receive 16 mg of sertindole or placebo as adjunctive treatment to clozapine.

Results:  Participants displayed substantial cognitive deficits, ranging from 1.6 standard deviation below norms at baseline to more than three standard deviations on tests of response readiness and focused attention. There were no significant differences between sertindole augmentation and placebo groups at study end. Correlation analysis of Positive and Negative Syndrome (PANSS) subscales, Global Assessment of Functioning subscale (GAF‐F) and Clinical Global Impression (CGI) with 20 neurocognitive indices was conducted, but no significant correlations were found. Second, we tested change from baseline to endpoint for the PANSS, GAF‐F, and CGI, vs. the concomitant changes in cognitive test performance, and found no significant correlations.

Conclusion:  The clozapine‐treated patients displayed marked cognitive deficits at baseline. Adding sertindole did not improve or worsen cognitive functioning, which is in line with previous negative studies of the effect on cognition of augmenting clozapine treatment with another antipsychotic drug.
Arabidopsis Plants Having Defects in Nonsense‐mediated mRNA Decay Factors UPF1, UPF2, and UPF3 Show Photoperiod‐dependent Phenotypes in Development and Stress Responses
Authors: Shi Chuan , Baldwin Ian T. , Wu Jianqiang
Published: February 2012

Nonsense‐mediated mRNA decay (NMD) is an important mRNA quality surveillance pathway in all eukaryotes that eliminates aberrant mRNAs derived from various sources. Three NMD factor proteins, UPF1, UPF2, and UPF3 are required for the NMD process and were found to be also involved in certain stress responses in mammalian and yeast cells. Using Arabidopsis thaliana mutants of UPF1 and UPF3 and UPF2‐silenced lines (irUPF2), we examined the involvement of UPF1, UPF2, and UPF3 in development and in response to stresses, wounding and infection by Pseudomonas syringae pv. tomato strain DC3000. Under the long (16 h) photoperiod condition, Arabidopsis having a defect in NMD factors exhibited altered morphologies of various organs, disturbed homeostasis of wounding‐induced jasmonic acid and pathogen‐elicited salicylic acid, and abnormal wounding‐ and methyl jasmonate‐induced changes in the transcript levels of two defense‐related genes, LOX2 and VSP2. Importantly, when plants were cultivated under the short (10 h) photoperiod condition, mutants of UPF1 and UPF3 and irUPF2 showed smaller differences from the wild‐type plants in growth and stress‐induced responses. These data suggest a complex regulatory network, likely composed of light signaling and NMD factor‐mediated pathways, in influencing plant development and adaption to environmental stresses.
Electrophysiological determinants of arrhythmic susceptibility upon endocardial and epicardial pacing in guinea‐pig heart
Authors: Osadchii O. E.
Published: February 2012

Aim

Endocardial pacing instituted to treat symptomatic bradycardia may nevertheless promote tachyarrhythmia in some pacemaker‐implanted patients. We sought to determine the contributing electrophysiological mechanisms.

Methods

Left ventricular (LV) monophasic action potential duration (APD90) and effective refractory periods were determined in perfused guinea‐pig hearts along with volume‐conducted ECG recordings during epicardial and endocardial stimulations.

Results

Consistent with electrotonic modulation of repolarization, APD90 at a given (either epicardial or endocardial) recording site tended to be longer while pacing from the ipsilateral LV site as compared to stimulations applied at the opposite side of ventricular wall. As a result, the intrinsic transmural repolarization gradient was amplified during endocardial pacing while being significantly reduced upon epicardial stimulations. The maximum slope of APD90 restitution was greater upon endocardial than epicardial pacing. The excitability was found to recur at earlier repolarization time point at endocardium than epicardium, thereby contributing to increased endocardial critical intervals for re‐excitation. Premature extrasystolic beats could have been elicited at shorter coupling stimulation intervals and propagated with greater transmural conduction delay upon endocardial than epicardial stimulations. Endocardial site exhibited lower ventricular fibrillation thresholds and greater inducibility of tachyarrhythmia upon extrasystolic stimulations as compared to epicardium.

Conclusion

Arrhythmic susceptibility in guinea‐pig heart is greater during endocardial than epicardial pacing because of greater transmural APD90 dispersion, steeper electrical restitution slopes, greater critical intervals for LV re‐excitation and slower transmural conduction of the earliest premature ectopic beats. Further studies are warranted to determine whether these effects may contribute to proarrhythmia in paced human patients.
Conceptual Design of Small-Sized HTGR System for Steam Supply and Electricity Generation (HTR50S)
Authors: Ohashi Hirofumi , Sato Hiroyuki , Tazawa Yujiro , Yan Xing L. , Tachibana Yukio , Kunitomi Kazuhiko
Published: February 2012

Japan Atomic Energy Agency (JAEA) has started a conceptual design of a small-sized HTGR for steam supply and electricity generation (HTR50S) to deploy the high temperature gas cooled reactor (HTGR) in developing countries at an early date (i.e., in the 2030s). Its reactor power is 50MWt and the reactor outlet temperature is 750°C. It is a first-of-kind of the commercial plant or a demonstration plant of a small-sized HTGR system for steam supply to the industries and the district heating, and electricity generation using a steam turbine. The design philosophy of the HTR50S is to upgrade the performance from the Japanese first HTGR (HTTR) and to reduce the cost for the commercialization by utilizing the knowledge obtained by the HTTR operation and the design of an advanced commercial plant of 600 MWt-class Very High Temperature Reactor (GTHTR300 series). The major specifications of the HTR50S were determined based on its design philosophy. And the targets of the technology demonstration using the HTR50S for the future commercial small-sized HTGR were identified. The system design of HTR50S was performed to offer the capability of electricity generation, cogeneration of electricity and steam for a district heating and industries. The market potential for the small-sized HTGR in the developing countries was evaluated for the application of the electricity, process heat, district heating and pure water production. It was confirmed that there is enough market potential for the small-sized HTGR in the developing countries. This paper described the major specification and system design of the HTR50S and the market potential for the small-sized HTGR in the developing countries.
Sandia’s Supercritical CO2 Direct Cycle Gas Fast Reactor (SC-GFR) Concept
Authors: Lewis Tom G. , Parma Edward J. , Wright Steven A. , Vernon Milton E. , Fleming Darryn D. , Rochau Gary E.
Published: February 2012

The advanced nuclear concept group at Sandia National Laboratories has been investigating two advance right size reactors (RSR); this paper will discuss one of these two systems. The supercritical carbon dioxide (S-CO2), direct cycle gas fast reactor (SC-GFR) concept was developed to determine the feasibility of a RSR type concept using S-CO2 as the working fluid in a direct cycle fast reactor. Although a significant amount of work is still required, this type of reactor concept maintains some potentially significant advantages over ideal gas-cooled systems and liquid metal-cooled systems. The analyses presented in this paper show that a relatively small long-life reactor core could be developed that maintains decay heat removal by natural circulation. The SC-GFR concept is a relatively small (200 MWth) fast reactor that is cooled with CO2 at a pressure of 20 MPa. The CO2 flows out of the reactor vessel at ∼650°C directly into a turbine-generator unit to produce electrical power. The thermodynamic cycle that is used for the power conversion is a supercritical gas Brayton cycle with CO2 as the working fluid. With the CO2 gas near the critical point after the heat rejection portion of the cycle, it can be compressed with less power as compared to a standard gas Brayton cycle, thereby allowing for a higher thermal efficiency at the same turbine inlet temperature. A cycle efficiency of 45–50% is theoretically achievable for an optimized configuration. The major advantages of the concept include the following: • High thermal efficiency at relatively low reactor outlet temperatures; • Compact, cost-effective, power conversion system; • Non-flammable, stable, inert, non-toxic, inexpensive, and well-characterized coolant; • Potential long-life core and closed fuel cycle; • Small void reactivity worth from loss of coolant; • Natural convection decay heat removal; • Feasible design using today’s technologies. The goal of this work was to develop a SC-GFR concept and perform scoping analyses, including a review of other concepts that are similar in nature, to determine concept feasibility, advantages, disadvantages, and issues requiring further investigation. Overall, the SC-GFR concept as described in this paper appears feasible and warrants further study.
URANUS: Korean Lead-Bismuth Cooled Small Modular Fast Reactor Activities
Authors: Choi Sungyeol , Hwang Il Soon , Cho Jae Hyun , Shim Chun Bo
Published: February 2012

Since 1994, Seoul National University (SNU) has developed an innovative future nuclear power based on LBE cooling advanced Partitioning and Transmutation (P&T) approach that leaves no high-level waste (HLW) behind with transmutation reactor named as Proliferation-resistant, Environment-friendly, Accident-tolerant, Continual, and Economical Reactor (PEACER). A small modular lead-bismuth cooled reactor has been designated as Ubiquitous, Robust, Accident-forgiving, Nonproliferating and Ultra-lasting Sustainer (URANUS-40) with a nominal electric power rating of 40 MW (100 MW thermal) that is well suited to be used as a distributed power source in either a single unit or a cluster for electricity, heat supply, and desalination. URANUS-40 is a pool type fast reactor with and an array of heterogeneous hexagonal core, fueled by proven low-enriched uranium dioxide fuels. The primary cooling system is designed to be operated by natural circulation. 3D seismic base isolation system is introduced underneath the entire reactor building allowing an earthquake of 0.5g zero period acceleration (ZPA) for the Safe Shutdown Earthquake (SSE). Also, the proliferation risk can be effectively managed by capsulized core design and a long refueling period (25yr).
Fabrication Roadmap as an Example for Small Modular Reactors
Authors: Mohr William , Levesque Steve
Published: February 2012

Small Modular Reactors (SMRs) are being designed to achieve many of the same goals as Generation IV reactors in much smaller individual package sizes. The experience with developing a fabrication roadmap to Generation IV reactors can be transferred as guidance for fabrication design of SMRs. Some areas where fabrication process development needs to come early in the sequence are materials for fast neutron areas, connections of thick to thin for combinations of pressure containment and fluid flow, fabrication with planned coating of internal surfaces, and materials that push beyond existing upper temperature limits. For instance, the Next Generation Nuclear Plant (NGNP) shifted to lower peak temperatures as the enormity of the materials qualification task for the originally planned peak temperatures became apparent. Materials replacements for long lifetime were needed in NGNP even when the peak temperature was lowered, with some like silicon carbide composite fuel rods not expected to be available for initial production. Several new welding techniques such as short-circuit transfer, narrow groove, tandem gas metal arc, hybrid laser-gas metal arc, and friction stir are also available. These techniques offer improved weld quality and higher productivity in assembly operations. Other fabrication considerations, such as qualification of joining methods, long life mechanical components, and dissimilar material joints will be discussed.
Emergence of Proteus mirabilis Harboring
bla
KPC-2
and
qnrD
in a Chinese Hospital
Authors: Hu Yan-yan , Cai Jia-chang , Zhang Rong , Zhou Hong-wei , Sun Qian , Chen Gong-xiang
Published: February 2012

Nineteen carbapenem-nonsusceptible
Proteus mirabilis
isolates were recovered from intensive care units in the Second Affiliated Hospital of Zhejiang University during a 3-month period. The isolates showed a high level of resistance against ciprofloxacin, in addition to their resistance against the carbapenems. Pulsed-field gel electrophoresis (PFGE) analysis showed that these isolates belonged to three clonal strains. PCRs and DNA sequence analysis of the carbapenemase and other β-lactamase genes indicated that all the isolates harbored the
bla
KPC-2
gene. Twelve of 19 isolates harbored the plasmid-mediated quinolone resistance (PMQR) genes, both the
qnrD
and
aac(6
′
)-Ib-cr
genes. Eight representative isolates with high levels of quinolone resistance carried the similar mutation profiles of S83I in
gyrA
, E466D in
gyrB
, and S80I in
parC
. Reduced carbapenem susceptibility was transferred to
Escherichia coli
(EC600) in a conjugation experiment, while the quinolone resistance was not. DNA hybridization showed that
qnrD
was located on a plasmid of approximately 4.5 kb. In summary, large clonally related isolates of KPC-2-producing
P. mirabilis
emerged in a Chinese hospital, and
qnrD
was detected in KPC-producing
P. mirabilis
for the first time.
Peroral Ciprofloxacin Therapy Impairs the Generation of a Protective Immune Response in a Mouse Model for Salmonella enterica Serovar Typhimurium Diarrhea, while Parenteral Ceftriaxone Therapy Does Not
Authors: Endt Kathrin , Maier Lisa , Käppeli Rina , Barthel Manja , Misselwitz Benjamin , Kremer Marcus , Hardt Wolf-Dietrich
Published: February 2012

Nontyphoidal
Salmonella
(NTS) species cause self-limiting diarrhea and sometimes severe disease. Antibiotic treatment is considered only in severe cases and immune-compromised patients. The beneficial effects of antibiotic therapy and the consequences for adaptive immune responses are not well understood. We used a mouse model for
Salmonella
diarrhea to assess the effects of
per os
treatment with ciprofloxacin (15 mg/kg of body weight intragastrically 2 times/day, 5 days) or parenteral ceftriaxone (50 mg/kg intraperitoneally, 5 days), two common drugs used in human patients. The therapeutic and adverse effects were assessed with respect to generation of a protective adaptive immune response, fecal pathogen excretion, and the emergence of nonsymptomatic excreters. In the mouse model, both therapies reduced disease severity and reduced the level of fecal shedding. In line with clinical data, in most animals, a rebound of pathogen gut colonization/fecal shedding was observed 2 to 12 days after the end of the treatment. Yet, levels of pathogen shedding and frequency of appearance of nonsymptomatic excreters did not differ from those for untreated controls. Moreover, mice treated intraperitoneally with ceftriaxone developed an adaptive immunity protecting the mice from enteropathy in wild-type
Salmonella enterica
serovar Typhimurium challenge infections. In contrast, the mice treated intragastrically with ciprofloxacin were not protected. Thus, antibiotic treatment regimens can disrupt the adaptive immune response, but treatment regimens may be optimized in order to preserve the generation of protective immunity. It might be of interest to determine whether this also pertains to human patients. In this case, the mouse model might be a tool for further mechanistic studies.
Targeted Intracellular Delivery of Antituberculosis Drugs to Mycobacterium tuberculosis-Infected Macrophages via Functionalized Mesoporous Silica Nanoparticles
Authors: Clemens Daniel L. , Lee Bai-Yu , Xue Min , Thomas Courtney R. , Meng Huan , Ferris Daniel , Nel Andre E. , Zink Jeffrey I. , Horwitz Marcus A.
Published: February 2012

Delivery of antituberculosis drugs by nanoparticles offers potential advantages over free drug, including the potential to target specifically the tissues and cells that are infected by
Mycobacterium tuberculosis
, thereby simultaneously increasing therapeutic efficacy and decreasing systemic toxicity, and the capacity for prolonged release of drug, thereby allowing less-frequent dosing. We have employed mesoporous silica nanoparticle (MSNP) drug delivery systems either equipped with a polyethyleneimine (PEI) coating to release rifampin or equipped with cyclodextrin-based pH-operated valves that open only at acidic pH to release isoniazid (INH) into
M. tuberculosis
-infected macrophages. The MSNP are internalized efficiently by human macrophages, traffic to acidified endosomes, and release high concentrations of antituberculosis drugs intracellularly. PEI-coated MSNP show much greater loading of rifampin than uncoated MSNP and much greater efficacy against
M. tuberculosis-
infected macrophages. MSNP were devoid of cytotoxicity at the particle doses employed for drug delivery. Similarly, we have demonstrated that the isoniazid delivered by MSNP equipped with pH-operated nanovalves kill
M. tuberculosis
within macrophages significantly more effectively than an equivalent amount of free drug. These data demonstrate that MSNP provide a versatile platform that can be functionalized to optimize the loading and intracellular release of specific drugs for the treatment of tuberculosis.
Altered Murine Tissue Colonization by Borrelia burgdorferi following Targeted Deletion of Linear Plasmid 17-Carried Genes
Authors: Casselli Timothy , Tourand Yvonne , Bankhead Troy
Published: February 2012

The causative agent of Lyme disease,
Borrelia burgdorferi
, possesses a segmented genome comprised of a single linear chromosome and upwards of 23 linear and circular plasmids. Much of what is known about plasmid-borne genes comes from studying laboratory clones that have spontaneously lost one or more plasmids during
in vitro
passage. Some plasmids, including the linear plasmid lp17, are never or rarely reported to be lost during routine culture; therefore, little is known about the requirement of these conserved plasmids for infectivity. In this study, the effects of deleting regions of lp17 were examined both
in vitro
and
in vivo
. A mutant strain lacking the genes
bbd16
to
bbd25
showed no deficiency in the ability to establish infection or disseminate to the bloodstream of mice; however, colonization of peripheral tissues was delayed. Despite the ability to colonize ear, heart, and joint tissues, this mutant exhibited a defect in bladder tissue colonization for up to 56 days postinfection. This phenotype was not observed in immunodeficient mice, suggesting that bladder colonization by the mutant strain was inhibited by an adaptive immune-based mechanism. Moreover, the mutant displayed increased expression of outer surface protein C
in vitro
, which was correlated with the absence of the gene
bbd18
. To our knowledge, this is the first report involving genetic manipulation of lp17 in an infectious clone of
B. burgdorferi
and reveals for the first time the effects of lp17 gene deletion during murine infection by the Lyme disease spirochete.
ON TWO-DIMENSIONAL MANIFOLDS WITH CONSTANT GAUSSIAN CURVATURE AND THEIR ASSOCIATED EQUATIONS
Authors: BRACKEN PAUL
Published: February 2012

The components for the frame field of a two-dimensional manifold with constant Gaussian curvature are determined for arbitrary nonzero curvature. The components of the frame fields are found from the structure equations and lead to specific nonlinear equations which pertain to surfaces with specific values of the Gaussian curvature. For negative curvature, the equation is of sine-Gordon type, and for positive curvature it is of sinh-Gordon type. The integrability and Bäcklund properties of these equations are then investigated by studying a differential ideal of two-forms which leads to the equations. As a consequence of studying the prolongation structure of each equation, a Lax pair and Bäcklund transformation are obtained.
NEARLY (θ1, θ2, θ3, ϕ)-DERIVATIONS ON HILBERT C*-MODULES
Authors: EBADIAN ALI , NIKOUFAR ISMAIL , GORDJI MADJID ESHAGHI
Published: February 2012

In this paper, we introduce the notion of (θ1, θ2, θ3, ϕ)-derivations on Hilbert C*-modules. Moreover, we investigate the generalized Hyers–Ulam–Rassias stability, Isac–Rassias type stability and superstability of (θ1, θ2, θ3, ϕ)-derivations on Hilbert C*-modules.
DOES HOME COUNTRY INSTITUTIONAL QUALITY MATTER FOR FOREIGN ASSET DIVESTITURES?
Authors: KETKAR SONIA , ALI SALEEM RAJA M.
Published: February 2012

Foreign divestments have become a regular feature of global investment patterns. These divestments have mainly been explained by changes in the economic and institutional factors of the host countries. Recently, as institutional quality has improved in emerging economies, perceived risks have decreased and divestments can no longer be fully explained by host country factors. This paper examines the effects of a firm's home country institutional quality on its divestment decisions in foreign markets. It also studies whether these factors affect developed and developing host countries differently during normal and crises years.
Modelling the decrease of total soluble salts of clayey soils during long-term soaking
Authors: Razouki S.S. , Kuttah D.K. , Jassim N.W.
Published: February 2012

Presented in this paper is an experimental investigation into the effect of long-term soaking on the decrease of total soluble salts (TSS) contents and distribution of moisture for compacted clayey gypsiferous soil. Two types (A and B) of clayey gypsiferous soils were used in this study. For each soaking period, two California bearing ratio (CBR) samples were prepared of type A soil and soaked under 70 and 10 lb (312 N and 45 N) surcharge loads suitable for highways. Various CBR soil samples of type B were prepared and soaked under 210, 140 and 70 lb (935 N, 623 N and 312 N) surcharge loads (suitable for airports) for the same soaking periods as type A CBR soil samples. For long-term soaking periods, a gradual drop in TSS (mainly gypsum) content took place at the top of CBR samples to reach a significant amount at the end of 180 days soaking. An empirical equation has been developed relating the initial total soluble salts contents to the total soluble salts contents after various soaking periods of CBR soil samples in the laboratory, taking into account the plasticity properties of the tested soils and the effect of surcharge load.
Swelling tests on material from the Guabirotuba Formation, Parana, Brazil, with suction control
Authors: Pereira E.M. , Pejon O.J. , Zuquette L.V.
Published: February 2012

This paper presents the swelling behaviour of clayey materials under controlled suction imposed both by a Richards chamber and by controlling the relative humidity with concentrated saline solutions. Soil-water characteristic curves (matrix and total) were determined by the filter paper method. The materials under study belong to the Guabirotuba Formation, of Pleistocene age, in the Curitiba Basin in the state of Paraná, southern Brazil. Materials under several stages of suction of 5000–40 000 kPa were subjected to swelling tests in an oedometer press. The results indicated that the greater the suction the higher the swelling pressure. However, when swelling tests were carried out with suction variation controlled by relative humidity, in which the increase in moisture was very slow, the samples showed no swelling.
Geochemical and mineralogical properties of the Lower Callovian (Jurassic) Kellaways Sand, variations in trace element concentrations and implications for hydrogeological risk assessment
Authors: Scotney P. M. , Joseph J. B. , Marshall J. E. A. , Lowe M. J. , Croudace I. W. , Milton J. A.
Published: February 2012

This paper provides details of the trace element and total organic carbon (TOC) content of the Lower Callovian Kellaways Sand. Heavy metals are associated with mineral phases such as pyrite, iron and manganese oxyhydroxides, organic matter and clay minerals, and correlations are varied. Using a multi-disciplinary approach and geochemical comparisons it has been shown that the Kellaways Sand is particularly enriched in Cr. Cr concentration data suggest two separate components, one bound with Ni and MnO, and the other occurring as an accessory resistate phase Fe–Ti–Cr oxide (ulvöspinel) with up to 4.7 wt% Cr
2
O
3
. The closest correlations between matrices are Zn and Ni with Fe
2
O
3
; V, Ni, Rb and Ga with MnO, MgO and K
2
O; Ni and MnO with TOC; and Cd with Zn. Average concentrations for trace elements and TOC are generally enriched in both the Oxford and Kellaways clays. Variable concentrations of SO
4
in associated groundwaters indicate that oxidation of FeS
2
influences the ranges and concentrations of trace elements observed through Eh and pH controlled adsorption or desorption reactions. The natural and variable concentrations of the metals that also occur in associated groundwaters (including Hg, Cd, Ni, As and Pb) have important implications for the associated, risk-based hydrogeological assessments completed for landfill sites contained within the Oxford Clay, and affect the choice of priority determinants significantly for the monitoring control and trigger levels.
Mapping and predicting electrical conductivity variations across southern England using airborne electromagnetic data
Authors: Beamish David , White James C.
Published: February 2012

Electrical conductivity of is one of the fundamental geophysical properties of rock formations and can be measured at field and laboratory scales. A recent airborne geophysical survey of the Isle of Wight and part of the adjacent mainland has provided an assessment of the near-surface (close to outcrop) electrical conductivities associated with Palaeogene and Cretaceous formations. This study examines the degree to which the high-resolution survey data contain distinctive geological and lithological signatures. The geostatistical nature of the conductivity distributions is examined in relation to two existing sedimentary bedrock schemes involving lithostratigraphical and simpler lithological descriptions. A close association between conductivity and bedrock geology is evident. It is then demonstrated how the central moments and dispersion statistics of the distributions may be used to predict the continuous, bedrock conductivity distribution across a large area of southern England, containing, as it does, a high population density and extensive infrastructure. The effectiveness of the method is demonstrated using the survey data obtained on the mainland and an existing database of vertical electric soundings.
Temporally coherent completion of dynamic shapes
Authors: Li Hao , Luo Linjie , Vlasic Daniel , Peers Pieter , Popović Jovan , Pauly Mark , Rusinkiewicz Szymon
Published: February 2012

We present a novel shape completion technique for creating temporally coherent watertight surfaces from real-time captured dynamic performances. Because of occlusions and low surface albedo, scanned mesh sequences typically exhibit large holes that persist over extended periods of time. Most conventional dynamic shape reconstruction techniques rely on template models or assume slow deformations in the input data. Our framework sidesteps these requirements and directly initializes shape completion with topology derived from the visual hull. To seal the holes with patches that are consistent with the subject's motion, we first minimize surface bending energies in each frame to ensure smooth transitions across hole boundaries. Temporally coherent dynamics of surface patches are obtained by unwarping all frames within a time window using accurate interframe correspondences. Aggregated surface samples are then filtered with a temporal visibility kernel that maximizes the use of nonoccluded surfaces. A key benefit of our shape completion strategy is that it does not rely on long-range correspondences or a template model. Consequently, our method does not suffer error accumulation typically introduced by noise, large deformations, and drastic topological changes. We illustrate the effectiveness of our method on several high-resolution scans of human performances captured with a state-of-the-art multiview 3D acquisition system.
Exposing photo manipulation with inconsistent reflections
Authors: O'Brien James F. , Farid Hany
Published: February 2012

The advent of sophisticated photo editing software has made it increasingly easier to manipulate digital images. Often visual inspection cannot definitively distinguish the resulting forgeries from authentic photographs. In response, forensic techniques have emerged to detect geometric or statistical inconsistencies that result from specific forms of photo manipulation. In this article we describe a new forensic technique that focuses on geometric inconsistencies that arise when fake reflections are inserted into a photograph or when a photograph containing reflections is manipulated. This analysis employs basic rules of reflective geometry and linear perspective projection, makes minimal assumptions about the scene geometry, and only requires the user to identify corresponding points on an object and its reflection. The analysis is also insensitive to common image editing operations such as resampling, color manipulations, and lossy compression. We demonstrate this technique with both visually plausible forgeries of our own creation and commercially produced forgeries.
PolyDepth
Authors: Je Changsoo , Tang Min , Lee Youngeun , Lee Minkyoung , Kim Young J.
Published: February 2012

We present a real-time algorithm that finds the Penetration Depth (PD) between general polygonal models based on iterative and local optimization techniques. Given an in-collision configuration of an object in configuration space, we find an initial collision-free configuration using several methods such as centroid difference, maximally clear configuration, motion coherence, random configuration, and sampling-based search. We project this configuration on to a local contact space using a variant of continuous collision detection algorithm and construct a linear convex cone around the projected configuration. We then formulate a new projection of the in-collision configuration onto the convex cone as a Linear Complementarity Problem (LCP), which we solve using a type of Gauss-Seidel iterative algorithm. We repeat this procedure until a locally optimal PD is obtained. Our algorithm can process complicated models consisting of tens of thousands triangles at interactive rates.
Stanford schooling---gratis!
Authors: Hyman Paul
Published: February 2012

Stanford University's experiment with online classes could help transform computer science education.
Do software copyrights protect what programs do?
Authors: Samuelson Pamela
Published: February 2012

A case before the European Court of Justice has significant implications for innovation and competition in the software industry.
GLADE
Authors: Rusu Florin , Dobra Alin
Published: February 2012

In this paper we introduce GLADE, a scalable distributed framework for large scale data analytics. GLADE consists of a simple user-interface to define Generalized Linear Aggregates (GLA), the fundamental abstraction at the core of GLADE, and a distributed runtime environment that executes GLAs by using parallelism extensively.

GLAs are derived from User-Defined Aggregates (UDA), a relational database extension that allows the user to add specialized aggregates to be executed inside the query processor. GLAs extend the UDA interface with methods to Serialize/Deserialize the state of the aggregate required for distributed computation. As a significant departure from UDAs which can be invoked only through SQL, GLAs give the user direct access to the state of the aggregate, thus allowing for the computation of significantly more complex aggregate functions.

GLADE runtime is an execution engine optimized for the GLA computation. The runtime takes the user-defined GLA code, compiles it inside the engine, and executes it right near the data by taking advantage of parallelism both inside a single machine as well as across a cluster of computers. This results in maximum possible execution time performance (all our experimental tasks are I/O-bound) and linear scaleup.
CIRCUMFLEX
Authors: Wolf Joel , Balmin Andrey , Rajan Deepak , Hildrum Kirsten , Khandekar Rohit , Parekh Sujay , Wu Kun-Lung , Vernica Rares
Published: February 2012

We consider MapReduce clusters designed to support multiple concurrent jobs, concentrating on environments in which the number of distinct datasets is modest relative to the number of jobs. Many datasets in such scenarios wind up being scanned by multiple concurrent Map phase jobs. As has been noticed previously, this scenario provides an opportunity for Map phase jobs to
cooperate
, sharing the scans of these datasets, and thus reducing the costs of such scans. Our paper has two main contributions. First, we present a novel and highly general method for sharing scans and thus amortizing their costs. This concept, which we call
cyclic piggybacking
, has a number of advantages over the more traditional
batching
scheme described in the literature. Second, we describe a significant but natural generalization of the recently introduced flex scheduler, for optimizing schedules within the context of this cyclic piggybacking paradigm. The overall approach, including both cyclic piggybacking and the flex generalization, is called circumflex. We demonstrate the excellent performance of circumflex via a variety of simulation experiments.
Adaptive and dynamic funnel replication in clouds
Authors: Laden Guy , Melamed Roie , Vigfusson Ymir
Published: February 2012

We consider the problem of strongly consistent replication in a multi data center cloud setting. This environment is characterized by high latency communication between data centers, significant fluctuations in the performance of seemingly identical virtual machines (VMs) and temporary disconnects of data centers from the rest of the cloud. In this paper we introduce the adaptive and dynamic Funnel Replication (FR) protocol that is designed to achieve high throughout and low latency for reads, to accommodate arbitrary latency/throughput tradeoffs for writes, to maximize performance in the face of VM performance variations and to provide high availability for read requests in the presence of network partitions. FR is based on the idea of flexible write dissemination topologies which enables it to achieve, per message, the desired tradeoff between latency and throughput, depending on the message size, the observed network conditions, and the importance of latency as indicated by the client. We demonstrate the benefits of flexible dissemination topologies and show that in a cloud setting with N identical replicas FR can improve the write latency up to a factor of N/2 for N ≥ 2 compared to the notable chain replication (CR) protocol at the expense of a slight decrease in the write throughput. In a setting with potentially high variability in the performance of replicas, e.g., as in Amazon EC2, FR can achieve throughput up to a factor of 16 higher than CR while also improving the latency. FR does this by adopting a topology that consists of concurrent disjoint data replication paths so that load on high throughput paths is adaptively increased while load on congested replicas is reduced.
Evaluation of compound system calls in the Linux kernel
Authors: Vicente Elder , Matias Rivalino , Borges Lúcio , Macêdo Autran
Published: February 2012

The overhead caused by system calls in many applications has motivated research works focusing on reducing their execution costs. In this work we implement different types of compound system calls, and evaluate them taking into account their execution time in a multicore computer. The experimental plan is conducted for both physical and virtual machine environments. The execution time dataset obtained through experiments statistically controlled is analysed and we show that all proposed compound calls present statistically significant performance gains when compared to their conventional counterparts, for both physical and virtual machine environments.
Proximal Gastrojejunal Reconstruction after Pancreaticoduodenal Resection
Authors: Wayne M. , Cooperman A. , Narang R. , Abbadessa B. , Bratcher J. , Brown W. , Steele J. , Kasmin F.
Published: February 2012

Introduction. Reconstruction by proximal gastrojejunostomy, and distal biliary and pancreatic anastomoses is infrequently used after resection of the head of the pancreas because of fear of fistulas and cholangitis. Pancreaticoduodenectomy is being performed more frequently for cystic malignant and premalignant lesions. Because of this there is a need for endoscopic visualization and biopsy of the residual pancreatic duct, since multi-centricity is characteristic of some of these malignancies. Since endoscopic access of the bile duct and pancreatic duct is difficult and unsuccessful in 50–70% after B II or Roux Y reconstruction, we prospectively studied the merit and complications (early and late) of proximal gastrojejunal (PGJ) reconstruction after pancreaticoduodenal resection.Material and Methods. Thirty nine consecutive, non-radomized patients underwent pancreaticoduodenectomy and PGJ reconstruction over 14 mos. There were 21 males and 18 females.Results. 7 patients with IPMN have undergone repeat CT scanning for surveillance, with 3 requiring repeat EUS and ERCP. There were no technical difficulties accessing the pancreas or the pancreatic duct, supporting the PGJ reconstruction.Conclusion. Proximal gastrojejunal reconstruction following pancreaticoduodenal resection may be safely done with similar morbidity to traditional pancreaticojejunal reconstructions. PGJ reconstruction may be of greater value when direct visual access to the bile duct or pancreatic duct is necessary, and should be considered when doing resection for mucinous cysts or IPMN of the head of the pancreas.
Mismatch Repair Proteins hMLH1 and hMSH2 Are Differently Expressed in the Three Main Subtypes of Sporadic Renal Cell Carcinoma
Authors: Stoehr Christine , Burger Maximilian , Stoehr Robert , Bertz Simone , Ruemmele Petra , Hofstaedter Ferdinand , Denzinger Stefan , Wieland Wolf F. , Hartmann Arndt , Walter Bernhard
Published: February 2012

Objectives: We studied the role of minor mismatch repair proteins (MMR) human MutL homologue 1 (hMLH1) and human MutS homologue 2 (hMSH2) in the main subtypes of renal cell carcinoma (RCC). Methods: Expression of MMR proteins hMLH1 and hMSH2 were investigated in 166 RCC tumors, containing the main subtypes by immunohistochemistry. Furthermore, each tumor was screened for microsatellite instability (MSI) using the National Cancer Institute consensus panel for hereditary non-polyposis colon carcinoma as well as for elevated microsatellite alterations at selected tetranucleotide repeats (EMAST) by 10 additional markers. Results: MSI was found only in 2.0% of analyzable cases and EMAST was detected only in 1 patient. hMLH1 and hMSH2 expression was reduced in 83.7 (118/141) and 51.2% (65/127) of cases, respectively, in a subtype-specific manner. None of the clear cell RCC tumors retained a high hMLH1 expression and 92.0% lost hMLH1 completely, while papillary and chromophobe RCC preserved the expression in 25.0 and 33.3% of cases (p < 0.001). Subtype specificity was also present in hMSH2 staining, where chromophobe RCC retained a high expression in 41.7% of cases, while clear cell and papillary tumors did not (29.9 and 23.1%; p = 0.01). Conclusion: MSI and EMAST are rare events in sporadic RCC, whereas diminished MMR protein expression is linked to tumor entity and might contribute to the different biological behavior of the RCC subtypes.
Electrophysiological Correlation and Prognostic Impact of Heat Shock Protein 27 in Atrial Fibrillation
Authors: Hu Yu-Feng , Yeh Hung-I , Tsao Hsuan-Ming , Tai Ching-Tai , Lin Yenn-Jiang , Chang Shih-Lin , Lo Li-Wei , Tuan Ta-Chuan , Suenari Kazuyoshi , Li Cheng-Hung , Chao Tze-Fan , Chen Shih-Ann
Published: February 2012

Background—

Heat shock protein (HSP) 27 is related to the pathogenesis of AF. However, the clinical relationship between HSP27 and AF is unclear. The present study was conducted to determine the clinical relationship between HSP27 and atrial fibrillation (AF).

Methods and Results—

A case-control study was conducted (AF, n=114; control, n=100). Serum HSP27 (HSP27S) levels were measured by ELISA, and its correlations with electrophysiological characteristics and catheter ablation outcomes were investigated. The patients with AF had a larger left atrial diameter (LAD), waist circumference, and body mass index, and a lower baseline HSP27S level, than controls. After logistic multivariate analysis, low baseline HSP27S was independently associated with AF. In patients with AF, those with paroxysmal AF (PAF) had higher baseline HSP27S levels compared with those without PAF. In patients with PAF, lower baseline HSP27S was associated with larger LAD, whereas baseline HSP27S was not correlated with LAD in controls. In PAF, low baseline HSP27S (≤3.85 ng/mL) was associated with low atrial voltage and nonpulmonary vein ectopies. In non-PAF, the mean fractionated interval had a good correlation with baseline HSP27S. After catheter ablation, a high baseline HSP27S level could predict sinus rhythm maintenance in the patients with PAF. Baseline HSP27S was also correlated with interleukin 10 and tumor necrosis factor-α levels. Analysis of buffy coat mRNA levels showed the same correlations.

Conclusions—

The HSP27S levels were correlated with LAD, left atrial voltage, and fractionated intervals, and predicted AF recurrence after catheter ablation. The mechanisms could be related to inflammation.
Relationship of National Institutes of Health Stroke Scale to 30‐Day Mortality in Medicare Beneficiaries With Acute Ischemic Stroke
Authors: Fonarow Gregg C. , Saver Jeffrey L. , Smith Eric E. , Broderick Joseph P. , Kleindorfer Dawn O. , Sacco Ralph L. , Pan Wenqin , Olson DaiWai M. , Hernandez Adrian F. , Peterson Eric D. , Schwamm Lee H.
Published: February 2012

Background

The National Institutes of Health Stroke Scale (NIHSS), a well‐validated tool for assessing initial stroke severity, has previously been shown to be associated with mortality in acute ischemic stroke. However, the relationship, optimal categorization, and risk discrimination with the NIHSS for predicting 30‐day mortality among Medicare beneficiaries with acute ischemic stroke has not been well studied.

Methods and Results

We analyzed data from 33102 fee‐for‐service Medicare beneficiaries treated at 404 Get With The Guidelines‐Stroke hospitals between April 2003 and December 2006 with NIHSS documented. The 30‐day mortality rate by NIHSS as a continuous variable and by risk‐tree determined or prespecified categories were analyzed, with discrimination of risk quantified by the
c
‐statistic. In this cohort, mean age was 79.0 years and 58% were female. The median NIHSS score was 5 (25th to 75th percentile 2 to 12). There were 4496 deaths in the first 30 days (13.6%). There was a strong graded relation between increasing NIHSS score and higher 30‐day mortality. The 30‐day mortality rates for acute ischemic stroke by NIHSS categories were as follows: 0 to 7, 4.2%; 8 to 13, 13.9%; 14 to 21, 31.6%; 22 to 42, 53.5%. A model with NIHSS alone provided excellent discrimination whether included as a continuous variable (
c
‐statistic 0.82 [0.81 to 0.83]), 4 categories (
c
‐statistic 0.80 [0.79 to 0.80]), or 3 categories (
c
‐statistic 0.79 [0.78 to 0.79]).

Conclusions

The NIHSS provides substantial prognostic information regarding 30‐day mortality risk in Medicare beneficiaries with acute ischemic stroke. This index of stroke severity is a very strong discriminator of mortality risk, even in the absence of other clinical information, whether used as a continuous or categorical risk determinant.