bluuebunny/crossref_metadata_2025 huggingface dataset:
Formation of Si1+ in the early stages of the oxidation of the Si[001] 2 × 1 surface
Authors: Herrera-Gomez Alberto , Aguirre-Tostado Francisco-Servando , Pianetta Piero
Published: December 2015

The early stages of the oxidation of the Si[001] 2 × 1 surface were studied with synchrotron radiation photoelectron spectroscopy. The analysis was based on the block approach, which is a refinement of spectra-subtraction that accounts for changes on the background signal and for band-bending shifts. By this method, it was possible to robustly show that the formation of Si1+ is due to oxygen bonding to the upper dimer atoms. Our results contrast with ab initio calculation, which indicates that the most favorable bonding site is the back-bond of the down-dimer.
Auditory streaming of tones of uncertain frequency, level, and duration
Authors: Chang An-Chieh , Lutfi Robert A. , Lee Jungmee
Published: December 2015

Stimulus uncertainty is known to critically affect auditory masking, but its influence on auditory streaming has been largely ignored. Standard ABA-ABA tone sequences were made increasingly uncertain by increasing the sigma of normal distributions from which the frequency, level, or duration of tones were randomly drawn. Consistent with predictions based on a model of masking by Lutfi, Gilbertson, Chang, and Stamas [J. Acoust. Soc. Am. 134, 2160–2170 (2013)], the frequency difference for which A and B tones formed separate streams increased as a linear function of sigma in tone frequency but was much less affected by sigma in tone level or duration.
Bioterrorism and the Role of the Clinical Microbiology Laboratory
Authors: Wagar Elizabeth
Published: December 2015

Regular review of the management of bioterrorism is essential for maintaining readiness for these sporadically occurring events. This review provides an overview of the history of biological disasters and bioterrorism. I also discuss the recent recategorization of tier 1 agents by the U.S. Department of Health and Human Services, the Laboratory Response Network (LRN), and specific training and readiness processes and programs, such as the College of American Pathologists (CAP) Laboratory Preparedness Exercise (LPX). LPX examined the management of cultivable bacterial vaccine and attenuated strains of tier 1 agents or close mimics. In the LPX program, participating laboratories showed improvement in the level of diagnosis required and referral of isolates to an appropriate reference laboratory. Agents which proved difficult to manage in sentinel laboratories included the more fastidious Gram-negative organisms, especially
Francisella tularensis
and
Burkholderia
spp. The recent Ebola hemorrhagic fever epidemic provided a check on LRN safety processes. Specific guidelines and recommendations for laboratory safety and risk assessment in the clinical microbiology are explored so that sentinel laboratories can better prepare for the next biological disaster.
Dystonia not dystopia: effects of the legal high, ‘Clockwork Orange’
Authors: Mackey Helen Elizabeth , Hawksley Oliver
Published: December 2015

A 27-year-old man presented to hospital after smoking a legal high named ‘Clockwork Orange’. He suffered dystonia, acute kidney injury, rhabdomyolysis, lactic acidosis and a troponin rise. He was treated with procyclidine and intravenous fluids.
Improving the diagnosis of pulmonary embolism in the emergency department
Authors: Cooper Jenni
Published: December 2015

The diagnosis of pulmonary embolism (PE) in the emergency department is challenging due to the wide range of non-specific symptoms, lack of clinical diagnostic criteria, and imperfect investigations. Various scoring systems exist in an attempt to limit unnecessary investigations in those with low risk of PE. Following a baseline audit and subsequent PDSA cycles we implemented a flowchart for use in patients suspected of pulmonary embolism encouraging the correct use of the Wells Score and Pulmonary Embolism Rule out Criteria (PERC).

The standard used for comparison was based on the NICE guidelines for diagnosis of PE with the addition that PERC could also be used if appropriate. Data was collected over four week periods before and after the introduction of our flowchart in two emergency departments in Melbourne. We aimed to increase documentation of pre-test probability, reduce inappropriate investigations, and increase the use of interim parenteral anticoagulation where there was a delay to imaging.

Results showed an increase in the documentation of pre-test probability and the proportion of investigations requested that were inappropriate was reduced. The percentage of inappropriate d-dimers was reduced from 36% to 24%; the percentage of inappropriate CTPAs was reduced from 34% to 10%; and the percentage of inappropriate V/Q scans was reduced from 42% to 14%.

Implementation of a simple diagnostic algorithm led to an increase in documentation of pre-test probability and a reduction in inappropriate and unnecessary investigations. This intervention may be applicable to other emergency departments where similar issues in diagnosing pulmonary embolism exist.
Improvement of fluid balance monitoring through education and rationalisation
Authors: Vincent Masaki , Mahendiran Thabo
Published: December 2015

Fluid input/output charts in hospital inpatients are a valuable source of information for doctors reviewing intravenous fluid prescription, but are notorious for being incomplete and inaccurate. Lack of awareness of the importance of fluid balance amongst nursing staff and an excess of unnecessary monitoring are two factors contributing to the problem. We conducted a quality improvement project on the respiratory ward in a large district general hospital aiming to specifically address these two factors. Pre-intervention audit showed that only 53% of input/output monitoring was clinically indicated, with an average chart completion of 50%. Using e-Learning and verbal presentation to raise awareness around fluid balance, we implemented a new system whereby daily medical review of charts lead to rationalisation of monitoring. Post-intervention audit showed a 93% reduction in unnecessary monitoring, with corresponding increases in completion (40%) and accuracy (48%) of remaining charts. In conclusion, education has enabled a culture change on the ward that has drastically increased the quality of fluid balance monitoring.
Using visual prompts to aid analgesia prescribing
Authors: Ryland Kathryn
Published: December 2015

Analgesia prescribing is fundamental to a patient's journey, affecting length of stay and patient experience. Laminated prompts are used throughout the NHS Foundation Trust to aid doctors prescribing.

A baseline questionnaire was carried out to gather doctors' prescribing habits and current ability to convert opioids to their morphine equivalent. Ninety three percent of doctors said they were moderately to extremely confident when prescribing analgesia. However, when asked to carry out a simple opioid conversion only 14% answered correctly. Eighty three percent of doctors said they were prescribing laxatives alongside opioids frequently (57%) or almost all the time (25%). When actual rates were sampled only 14% of patients were prescribed a concurrent laxative.

Laminated pain management guideline cards were created and distributed to doctors at sign in for weekly teaching.

Doctor interviews were carried out to see if they were in possession of a prompt card and a simple opioid conversion question was asked. If they did not have a prompt card at the time of interview they were issued with one after answering the conversion question. Rates of concurrent laxative prescribing were collected from the electronic prescribing record of patients on the acute medical unit. Posters were displayed in doctors' offices and drug rooms. Laxative prescribing rates were re-collected and compared with the survey responses.

Distribution of laminated prompts increased accuracy of opioid conversion by 86%. Error rates fell as prompt prevalence increased until there was 100% prevalence and 0% error. Concurrent prescribing of laxatives increased to 50% after posters were displayed around the acute medical unit.

Doctors reported they were confident when prescribing analgesia. They reported that they often prescribed concurrent medications, however this did not relate to actual prescribing practices. Visual prompts improved doctors analgesia conversion knowledge and prescribing practices.

Laminated prompt cards are now incorporated in new doctors' induction packs.
Cancer incidence and survival in Lynch syndrome patients receiving colonoscopic and gynaecological surveillance: first report from the prospective Lynch syndrome database
Authors: Møller Pål , Seppälä Toni , Bernstein Inge , Holinski-Feder Elke , Sala Paola , Evans D Gareth , Lindblom Annika , Macrae Finlay , Blanco Ignacio , Sijmons Rolf , Jeffries Jacqueline , Vasen Hans , Burn John , Nakken Sigve , Hovig Eivind , Rødland Einar Andreas , Tharmaratnam Kukatharmini , de Vos tot Nederveen Cappel Wouter H , Hill James , Wijnen Juul , Green Kate , Lalloo Fiona , Sunde Lone , Mints Miriam , Bertario Lucio , Pineda Marta , Navarro Matilde , Morak Monika , Renkonen-Sinisalo Laura , Frayling Ian M , Plazzer John-Paul , Pylvanainen Kirsi , Sampson Julian R , Capella Gabriel , Mecklin Jukka-Pekka , Möslein Gabriela ,   in collaboration with The Mallorca Group (http://mallorca-group.eu)
Published: December 2015

Objective

Estimates of cancer risk and the effects of surveillance in Lynch syndrome have been subject to bias, partly through reliance on retrospective studies. We sought to establish more robust estimates in patients undergoing prospective cancer surveillance.

Design

We undertook a multicentre study of patients carrying Lynch syndrome-associated mutations affectingMLH1,MSH2,MSH6orPMS2. Standardised information on surveillance, cancers and outcomes were collated in an Oracle relational database and analysed by age, sex and mutated gene.

Results

1942 mutation carriers without previous cancer had follow-up including colonoscopic surveillance for 13 782 observation years. 314 patients developed cancer, mostly colorectal (n=151), endometrial (n=72) and ovarian (n=19). Cancers were detected from 25 years onwards inMLH1andMSH2mutation carriers, and from about 40 years inMSH6andPMS2carriers. Among first cancer detected in each patient the colorectal cancer cumulative incidences at 70 years by gene were 46%, 35%, 20% and 10% forMLH1, MSH2, MSH6andPMS2mutation carriers, respectively. The equivalent cumulative incidences for endometrial cancer were 34%, 51%, 49% and 24%; and for ovarian cancer 11%, 15%, 0% and 0%. Ten-year crude survival was 87% after any cancer, 91% if the first cancer was colorectal, 98% if endometrial and 89% if ovarian.

Conclusions

The four Lynch syndrome-associated genes had different penetrance and expression. Colorectal cancer occurred frequently despite colonoscopic surveillance but resulted in few deaths. Using our data, a website has been established athttp://LScarisk.orgenabling calculation of cumulative cancer risks as an aid to genetic counselling in Lynch syndrome.
Achieving all-age helmet use compliance for snow sports: strategic use of education, legislation and enforcement
Authors: Fenerty Lynne , Heatley Jennifer , Young Julian , Thibault-Halman Ginette , Kureshi Nelofar , Bruce Beth S , Walling Simon , Clarke David B
Published: December 2015

Background

Nova Scotia is the first jurisdiction in the world to mandate ski and snowboard helmet use for all ages at ski hills in the province. This study represents a longitudinal examination of the effects of social marketing, educational campaigns and the introduction of helmet legislation on all-age snow sport helmet use in Nova Scotia.

Methods

A baseline observational study was conducted to establish the threshold of ski and snowboarding helmet use. Based on focus groups and interviews, a social marketing campaign was designed and implemented to address factors influencing helmet use. A prelegislation observational study assessed the effects of social marketing and educational promotion on helmet use. After all-age snow sport helmet legislation was enacted and enforced, a postlegislation observational study was conducted to determine helmet use prevalence.

Results

Baseline data revealed that 74% of skiers and snowboarders were using helmets, of which 80% were females and 70% were males. Helmet use was high in children (96%), but decreased with increasing age. Following educational and social marketing campaigns, overall helmet use increased to 90%. After helmet legislation was enacted, 100% compliance was observed at ski hills in Nova Scotia.

Conclusions

Results from this study demonstrate that a multifaceted approach, including education, legislation and enforcement, was effective in achieving full helmet compliance among all ages of skiers and snowboarders.
Lupus anticoagulant, disease activity and low complement in the first trimester are predictive of pregnancy loss
Authors: Mankee Anil , Petri Michelle , Magder Laurence S
Published: December 2015

Introduction

Multiple factors, including proteinuria, antiphospholipid syndrome, thrombocytopenia and hypertension, are predictive of pregnancy loss in systemic lupus erythematosus (SLE). In the PROMISSE study of predictors of pregnancy loss, only a battery of lupus anticoagulant tests was predictive of a composite of adverse pregnancy outcomes. We examined the predictive value of one baseline lupus anticoagulant test (dilute Russell viper venom time) with pregnancy loss in women with SLE.

Methods

From the Hopkins Lupus Cohort, there were 202 pregnancies from 175 different women after excluding twin pregnancies and pregnancies for which we did not have a first trimester assessment of lupus anticoagulant. We determined the percentage of women who had a pregnancy loss in groups defined by potential risk factors. The lupus anticoagulant was determined by dilute Russell viper venom time with appropriate mixing and confirmatory testing. Generalised estimating equations were used to calculate p values, accounting for repeated pregnancies in the same woman.

Results

The age at pregnancy was <20 years (2%), 20–29 (53%), 30–39 (41%) and >40 (3%). 55% were Caucasian and 34% African-American. Among those with lupus anticoagulant during the first trimester, 6/16 (38%) experienced a pregnancy loss compared with only 16/186 (9%) of other pregnancies (p=0.003). In addition, those with low complement or higher disease activity had a higher rate of pregnancy loss than those without (p=0.049 and 0.005, respectively). In contrast, there was no association between elevated anticardiolipin in the first trimester and pregnancy loss.

Conclusions

The strongest predictor of pregnancy loss in SLE in the first trimester is the lupus anticoagulant. In addition, moderate disease activity by the physician global assessment and low complement measured in the first trimester were predictive of pregnancy loss. These data suggest that treatment of the lupus anticoagulant could be considered, even in the absence of history of pregnancy loss.
Comparison of four different collateral scores in acute ischemic stroke by CT angiography
Authors: Seker Fatih , Potreck Arne , Möhlenbruch Markus , Bendszus Martin , Pham Mirko
Published: December 2015

Purpose

Multiple scores have been described for the assessment of collateralization in acute ischemic stroke. Currently, there is no gold standard for collateral assessment by CT angiography (CTA). This study compared four frequently used collateral scores with regard to their correlation with early infarct core and mismatch ratio.

Methods

30 consecutive patients with acute occlusion of the M1 segment or terminal carotid artery were reviewed retrospectively. Collaterals were assessed using dynamic and also single-phase CTA according to grading systems by the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR), Alberta Stroke Program Early CT Score (ASPECTS) (on collaterals), Christoforidiset aland Miteffet al. The Christoforidis and ASITN/SIR scores, which were initially designed for conventional angiography, were adapted to be applicable to CTA. The scores were compared with respect to early infarct core and mismatch ratio in perfusion CT estimated by RAPID software using Spearman correlation.

Results

ASITN/SIR and ASPECTS collateral scores showed good correlation with early infarct core (rho=−0.696, p<0.001 and rho=−0.677, p<0.001) and mismatch ratio (rho=0.609, p<0.001 and rho=0.581, p<0.001). In contrast, the Christoforidis and Miteff scores correlated less well with infarct core (rho=0.245, p=0.191 and rho=−0.272, p=0.145, respectively) and mismatch ratio (rho=−0.329, p=0.075 and rho=0.279, p=0.135, respectively). ASPECTS and ASITN/SIR showed excellent cross-correlation (rho=0.901, p<0.001).

Conclusions

Compared with the Christoforidis and Miteff scores, the modified ASITN/SIR and ASPECTS collateral scores showed consistently higher correlation with the extent of early infarct core and mismatch volume. This is probably because these scores evaluate the extent and delay of vascular enhancement in the affected territory rather than the backflow of contrast medium to the occlusion.
Maternal and postweaning folic acid supplementation interact to influence body weight, insulin resistance, and food intake regulatory gene expression in rat offspring in a sex-specific manner
Authors: Huot Pedro S.P. , Ly Anna , Szeto Ignatius M.Y. , Reza-López Sandra A. , Cho Daniel , Kim Young-In , Anderson G. Harvey
Published: December 2015

Maternal intake of multivitamins or folic acid above the basal dietary requirement alters the growth and metabolic trajectory of rat offspring. We hypothesized that a modest increase in the folic acid content of maternal diets would alter the offspring’s metabolic phenotype, and that these effects could be corrected by matching the folic acid content of the offspring’s diet with that of the maternal diet. Female Sprague–Dawley rats were placed on a control or a 2.5× folic acid-supplemented diet prior to mating and during pregnancy and lactation. At weaning, pups from each maternal diet group were randomized to the control or to the 2.5× folic acid-supplemented diet for 25 weeks. Male pups from dams fed the folic acid-supplemented diet were 3.7% heavier than those from control-fed dams and had lower mRNA expression for leptin receptor Obrb isoform (Lepr) (11%) and Agouti-related protein (Agrp) (14%). In contrast, female pups from folic acid-supplemented dams were 5% lighter than those from control-fed dams and had lower proopiomelanocortin (Pomc) (42%), Lepr (32%), and Agrp (13%), but higher neuropeptide Y (Npy) (18%) mRNA expression. Folic acid supplementation ameliorated the alterations induced by maternal folic acid supplementation in male pups and led to the lowest insulin resistance, but the effects were smaller in female pups and led to the highest insulin resistance. In conclusion, maternal folic acid supplementation at 2.5× the control level was associated with alterations in body weight and hypothalamic gene expression in rat offspring in a sex-specific manner, and some of these effects were attenuated by postweaning folic acid supplementation.
Transcript level ofAKR1C3is down-regulated in gastric cancer
Authors: Frycz Bartosz Adam , Murawa Dawid , Borejsza-Wysocki Maciej , Wichtowski Mateusz , Spychała Arkadiusz , Marciniak Ryszard , Murawa Paweł , Drews Michał , Jagodziński Paweł Piotr
Published: December 2015

Steroid hormones have been shown to play a role in gastric carcinogenesis. Large amounts of steroid hormones are locally produced in the peripheral tissues of both genders. Type 5 of 17β-hydroxysteroid dehydrogenase, encoded by the AKR1C3 gene, plays a pivotal role in both androgen and estrogen metabolism, and its expression was found to be deregulated in different cancers. In this study we measured AKR1C3 transcript and protein levels in nontumoral and primary tumoral gastric tissues, and evaluated their association with some clinicopathological features of gastric cancer (GC). We found decreased levels of AKR1C3 transcript (p < 0.0001) and protein (p = 0.0021) in GC tissues compared with the adjacent, apparently histopathologically normal, mucosa. Lower levels of AKR1C3 transcript were observed in diffuse and intestinal types of GC, whereas AKR1C3 protein levels were decreased in tumors with multisite localization, in diffuse histological type, T3, T4, and G3 grades. We also determined the effect of the histone deacetylase inhibitor sodium butyrate (NaBu) on AKR1C3 expression in EPG 85-257 and HGC-27 GC cell lines. We found that NaBu elevates the levels of both AKR1C3 transcript and protein in the cell lines we investigated. Together, our results suggest that decreased expression of AKR1C3 may be involved in development of GC and can be restored by NaBu.
Net rate of energy intake predicts reach-level steelhead (Oncorhynchus mykiss) densities in diverse basins from a large monitoring program
Authors: Wall C. Eric , Bouwes Nicolaas , Wheaton Joseph M. , Saunders W. Carl , Bennett Stephen N.
Published: December 2015

Substantial research effort has been devoted to understanding stream-dwelling salmonids’ use of summer rearing and growth habitat, with a subset of studies focusing on foraging position selection and the energetic trade-offs of differential habitat use. To date, however, cost–benefit analyses for most foraging model studies have focused on small sampling areas such as individual habitat units. To address this knowledge gap, we applied a mechanistic foraging model to 22 stream reaches (100–400 m) from two watersheds within the Columbia River Basin. We found a strong, positive correlation (R2= 0.61, p < 0.001) between predicted carrying capacities and observed fish densities. Predicted proportion of suitable habitat was weakly correlated with observed fish density (R2= 0.18, p = 0.051), but the mean net rate of energy intake prediction in sampling reaches was not a significant predictor of observed fish biomass. Our results suggest spatial configuration of habitat, in addition to quantity and quality, is an important determinant of habitat use. Further, carrying capacity predicted by the model shows promise as a habitat metric. We also evaluated the feasibility of applying this data-intensive modeling approach in a large-scale monitoring program to examine habitat quality and quantity. Though the approach can be computationally expensive, we feel the model’s ability to integrate physical habitat metrics (e.g., depth, velocity) with important biological considerations like food availability and temperature is a benefit that far outweighs associated costs. We feel this modeling approach has great potential as a tool to help understand habitat use in drift-feeding fishes.
Deconfining phase transition in a finite volume with massive particles: finite size and finite mass effects
Authors: Ghenam L. , Ait El Djoudi A. , Mezouar K.
Published: December 2015

We study the deconfining phase transition from a hadronic gas phase consisting of massive pions to a quark–gluon plasma (QGP) phase containing gluons, massless up and down quarks, and massive strange quarks. The two phases are supposed to coexist in a finite volume, and the finite size effects are studied, in the two cases of thermally driven and density driven deconfining phase transitions. Finite-mass effects are also examined, then the color-singletness condition for the QGP is taken into account and finite size effects are investigated in this case also.
ANTI-BACTERIAL APPLICATIONS FOR NEW THERMAL CONDUCTIVITY MODEL IN ARTERIES WITH CNT SUSPENDED NANOFLUID
Authors: AKBAR NOREEN SHER , RAZA M. , ELLAHI R.
Published: December 2015

The peristaltic flow of a carbon nanotubes (CNTs) water fluid investigate the effects of heat generation and magnetic field in permeable vertical diverging tube is studied. The mathematical formulation is presented, the resulting equations are solved exactly. The obtained expressions for pressure gradient, pressure rise, temperature, velocity profile are described through graphs for various pertinent parameters. The streamlines are drawn for some physical quantities to discuss the trapping phenomenon. It is observed that pressure gradient profile is decreasing by increase of Darcy number [Formula: see text] because Darcy number is due to porous permeable walls of the tube and when walls are porous fluid cannot easily flow in tube, so that will decrease the pressure gradient.
Secure N-dimensional simultaneous dense coding and applications
Authors: Situ H. , Qiu D. , Mateus P. , Paunković N.
Published: December 2015

Simultaneous dense coding (SDC) guarantees that Bob and Charlie simultaneously receive their respective information from Alice in their respective processes of dense coding. The idea is to use the so-called locking operation to “lock” the entanglement channels, thus requiring a joint unlocking operation by Bob and Charlie in order to simultaneously obtain the information sent by Alice. We present some new results on SDC: (1) We propose three SDC protocols, which use different N-dimensional entanglement (Bell state, W state and GHZ state). (2) Besides the quantum Fourier transform, two new locking operators are introduced (the double controlled-NOT operator and the SWAP operator). (3) In the case that spatially distant Bob and Charlie have to finalize the protocol by implementing the unlocking operation through communication, we improve our protocol’s fairness, with respect to Bob and Charlie, by implementing the unlocking operation in series of steps. (4) We improve the security of SDC against the intercept–resend attack. (5) We show that SDC can be used to implement a fair contract signing protocol. (6) We also show that the N-dimensional quantum Fourier transform can act as the locking operator in simultaneous teleportation of N-level quantum systems.
Challenges and Opportunities of Integrating Human Health into the Environmental Assessment Process: The Canadian Experience Contextualised to International Efforts
Authors: Mahboubi Pouyan , Parkes Margot W. , Chan Hing Man
Published: December 2015

A scoping review of the literature was conducted to identify the most pressing issues pertaining to the application of Health Impact Assessment (HIA) and the integration of health concerns into the Environmental Assessment (EA) process in Canada and internationally. The issues identified include the need for government intervention, gaps in methodology and tools, limitations of capacity and expertise, poor intersectoral, disciplinary and public collaboration/participation, challenges of data quantification and analytic complexity, and the need for process efficiency. The issues presented were also contextualised to the status quo practice of EA in Canada and the Canadian Environmental Assessment Act (CEAA 2012). Recommendations were proposed as a starting point for improved integration. First, a commitment by the actors involved to the protection of human health — aligned with the core mandate of the CEAA. Second, the achievement of intersectoral, disciplinary and public collaboration, led by government, ideally the health sector. The case is made for a new era of Canadian leadership and innovation at the interface of health and EA.
IS THE IPCC’s 5THASSESSMENT A DENIER OF POSSIBLE MACROECONOMIC BENEFITS FROM MITIGATING CLIMATE CHANGE?
Authors: ROSEN RICHARD A.
Published: December 2015

This review summarizes what we know about the macroeconomics of mitigating climate change over the period 2010 to 2100 as presented in the 2014 IPCC Working Group III report. The review finds that little more, if anything, has been learned about the macroeconomics of mitigating climate change over the long run since the 2007 IPCC report. Furthermore, while the 2014 report is quite self-critical about the serious weaknesses in its methodologies, the self-criticisms are not explicitly taken into account when the net macroeconomic costs of mitigation are reported. Nor do the research teams that run the integrated assessment models relied on in the report utilize any systematic methodology for assessing the inherent uncertainty in the macroeconomic results reported. Thus, the basic quantitative “findings” are misleading — and, perhaps, even deceptive — in part because they appear to preclude the possibility of large macroeconomic benefits from mitigating climate change.
Geochemical characteristics and palaeoenvironmental reconstruction of the sediments from the Gulf of Tonkin, South China Sea
Authors: Cui Zhenang , Hou Yueming , Xia Zhen , Liang Kai , Xue Qiao , Zhang Liang
Published: December 2015

Geochemical investigations of sediments from core GC22 from the Tonkin Gulf, South China Sea, have been carried out in order to reconstruct the palaeoenvironmental evolution of the area during the Holocene. Vertical variations in Al/Ti, K/Al and Mg/Al clearly indicate the degree of chemical weathering in the source area. Zr/Ti and SiO
2
/Al
2
O
3
recorded the history of current velocity changes, and La/Co v. La/Sc, combined with distribution patterns of rare earth elements, suggested that Hainan Island was the main source of the sediments during the Holocene. Based on the results of the analysis, the evolution of palaeoenvironments in the Tonkin Gulf can be divided into four stages: (1) 10.12–6.46 ka BP, the regional climate got warmer, and the sea level of the gulf rose rapidly, which is indicated by rapid declines in Sr/Ba and CaO. (2) 6.46–4.3 ka BP, the gulf had a stable depositional environment, and the local climate became cold and dry. (3) 4.3–3.55 ka BP, the currents and sedimenary provenance in the gulf were significantly influenced by the opening of the Qiongzhou Strait. (4) 3.55 ka BP–present, the regional sea level remained roughly stable.
Efficient Code Assignment Techniques for Local Memory on Software Managed Multicores
Authors: Lu Jing , Bai Ke , Shrivastava Aviral
Published: December 2015

Scaling the memory hierarchy is a major challenge when we scale the number of cores in a multicore processor. Software Managed Multicore (SMM) architectures come up as one of the promising solutions. In an SMM architecture, there are no caches, and each core has only a local scratchpad memory [Banakar et al. 2002]. As the local memory usually is small, large applications cannot be directly executed on it. Code and data of the task mapped to each core need to be managed between global memory and local memory. This article solves the problem of efficiently managing code on an SMM architecture. The primary requirement of generating efficient code assignments is a correct management cost model. In this article, we address this problem by proposing a cost calculation graph. In addition, we develop two heuristics
CMSM
(Code Mapping for Software Managed multicores) and
CMSM_advanced
that result in efficient code management execution on the local scratchpad memory. Experimental results collected after executing applications from the MiBench suite [Guthaus et al. 2001] demonstrate that merely by adopting the correct management cost calculation, even using previous code assignment schemes, we can improve performance by an average of 12%. Combining the correct management cost model and a more optimized code mapping algorithm together, our heuristics can reduce runtime in more than 80% of the cases, and by up to 20% on our set of benchmarks, compared to the state-of-the-art code assignment approach [Jung et al. 2010]. When compared with Instruction-level Parallelism (ILP) results,
CMSM_advanced
performs an average of 5% worse. We also simulate the benchmarks on a cache-based system, and find that the code management overhead on SMM core with our code management is much less than memory latency of a cache-based system.
Faster Spectral Sparsification and Numerical Algorithms for SDD Matrices
Authors: Koutis Ioannis , Levin Alex , Peng Richard
Published: December 2015

We study algorithms for spectral graph sparsification. The input is a graph
G
with
n
vertices and
m
edges, and the output is a sparse graph
G˜
that approximates
G
in an algebraic sense. Concretely, for all vectors
x
and any ϵ > 0, the graph
G˜
satisfies (1-ϵ )

x

T

L

G

x

≤
x

T

L
G˜

x

≤ (1+ϵ)
x

T

L

G

x

, where

L
G

and
G˜
are the Laplacians of
G
and
G˜
respectively.

The first contribution of this article applies to all existing sparsification algorithms that rely on solving solving linear systems on graph Laplacians. These algorithms are the fastest known to date. Specifically, we show that less precision is required in the solution of the linear systems, leading to speedups by an
O
(log
n
) factor. We also present faster sparsification algorithms for slightly dense graphs:

— An
O
(
m
log
n
) time algorithm that generates a sparsifier with
O
(
n
log
3
n
/ϵ
2
) edges.

— An
O
(
m
log log
n
) time algorithm for graphs with more than
n
log
5
n
log log
n
edges.

— An
O
(
m
) algorithm for graphs with more than
n
log
10
n
edges.

— An
O
(
m
) algorithm for unweighted graphs with more than
n
log
8
n
edges.

These bounds hold up to factors that are in
O
(
poly
(log log
n
)) and are conjectured to be removable.
Perpetuu
Authors: Matthews Adam , Bobovych Stanislav , Banerjee Nilanjan , Parkerson James P. , Robucci Ryan , Patel Chintan
Published: December 2015

The aftermath of a natural disaster is characterized by lack of a reliable medium for dissemination of information to survivors. The state-of-the-art emergency response systems rely on satellite radio-enabled devices, but survivors, unlike first responders, do not have access to such devices. To mitigate this problem, we present perpetuu, a solar-powered portable GIS microserver. The microserver node can be deployed in a disaster scene and can serve maps to survivors viewable on browsers of off-the-shelf mobile systems. The perpetuu nodes can form a wireless mesh to cover a large geographic region. A key innovation in the design of the perpetuu node is a tiered software and hardware architecture—the system combines a low-power micro-controller with a high-power micro-processor to provide a large spectrum of power states. perpetuu stays in its lowest power state most of the time, and it can in-vitro detect survivors using Wi-Fi sensing, and consequently wake up the higher-power tier to disseminate high-resolution maps on standard web browsers that provide directions to safe locations. The tiered design leverages hardware-assisted energy measurements and a wakeup controller to balance energy harvested from solar panels with energy consumed by the system. We evaluate perpetuu using measurements from our prototype and trace-based simulations, and show that it can function near-perpetually while serving maps to a large number of survivors.
Incremental Analysis of Cyclo-Static Synchronous Dataflow Graphs
Authors: Groote Robert De , Hölzenspies Philip K. F. , Kuper Jan , Smit Gerard J. M.
Published: December 2015

In this article, we present a mathematical characterisation of admissible schedules of cyclo-static dataflow (
csdf
) graphs. We demonstrate how algebra ic manipulation of this characterization is related to unfolding
csdf
actors and how this manipulation allows
csdf
graphs to be transformed into
mrsdf
graphs that are
equivalent
, in the sense that they admit the same set of schedules. The presented transformation allows the rich set of existing analysis techniques for
mrsdf
graphs to be applied to
csdf
graphs and generalizes the well-known transformations from
csdf
and
mrsdf
into
hsdf
. Moreover, it gives rise to an incremental approach to the analysis of
csdf
graphs, where approximate analyses are combined with exact transformations. We show the applicability of this incremental approach by demonstrating its effectiveness on the problem of optimizing buffer sizes under a throughput constraint.
Linear Kernels and Single-Exponential Algorithms Via Protrusion Decompositions
Authors: Kim Eun Jung , Langer Alexander , Paul Christophe , Reidl Felix , Rossmanith Peter , Sau Ignasi , Sikdar Somnath
Published: December 2015

We present a linear-time algorithm to compute a decomposition scheme for graphs
G
that have a set
X
⊆
V
(
G
), called a
treewidth-modulator
, such that the treewidth of
G
−
X
is bounded by a constant. Our decomposition, called a
protrusion decomposition
, is the cornerstone in obtaining the following two main results. Our first result is that any parameterized graph problem (with parameter
k
) that has a
finite integer index
and such that Y
es
-instances have a treewidth-modulator of size
O
(
k
) admits a linear kernel on the class of
H
-topological-minor-free graphs, for any fixed graph
H
. This result partially extends previous meta-theorems on the existence of linear kernels on graphs of bounded genus and
H
-minor-free graphs. Let
F
be a fixed finite family of graphs containing at least one planar graph. Given an
n
-vertex graph
G
and a non-negative integer
k
, P
lanar
-
F
-D
eletion
asks whether
G
has a set
X
⊆
V
(
G
) such that |
X
| ⩽
k
and
G
−
X
is
H
-minor-free for every
H
ϵ
F
. As our second application, we present the first
single-exponential
algorithm to solve P
lanar
-
F
-D
eletion
. Namely, our algorithm runs in time 2

O
(
k
)

·
n
2
, which is asymptotically optimal with respect to
k
. So far, single-exponential algorithms were only known for special cases of the family
F
.
Scalable Global Power Management Policy Based on Combinatorial Optimization for Multiprocessors
Authors: Pan Gung-Yu , Yang Jed , Jou Jing-Yang , Lai Bo-Cheng Charles
Published: December 2015

Multiprocessors have become the main architecture trend in modern systems due to the superior performance; nevertheless, the power consumption remains a critical challenge. Global power management (GPM) aims at dynamically finding the power state combination that satisfies the power budget constraint while maximizing the overall performance (or vice versa). Due to the increasing number of cores in a multiprocessor system, the scalability of GPM policies has become critical when searching satisfactory state combinations within acceptable time. This article proposes a highly scalable policy based on combinatorial optimization with theoretical proofs, whereas previous works take exhaustive search or heuristic methods. The proposed policy first applies an optimum algorithm to construct a state combination table in pseudo--polynomial time using dynamic programming. Then, the state combination is assigned to cores with minimum transition cost in linear time by mapping to the network flow problem. Simulation results show that the proposed policy achieves better system performance for any given power budget when compared to the state-of-the-art heuristic. Furthermore, the proposed policy demonstrates its prominent scalability with 125 times faster policy runtime for 512 cores.
Rethinking Memory Permissions for Protection Against Cross-Layer Attacks
Authors: Elwell Jesse , Riley Ryan , Abu-Ghazaleh Nael , Ponomarev Dmitry , Cervesato Iliano
Published: December 2015

The inclusive permissions structure (e.g., the Intel ring model) of modern commodity CPUs provides privileged system software layers with arbitrary permissions to access and modify client processes, allowing them to manage these clients and the system resources efficiently. Unfortunately, these inclusive permissions allow a compromised high-privileged software layer to perform arbitrary malicious activities. In this article, our goal is to prevent attacks that cross system layers while maintaining the abilities of system software to manage the system and allocate resources. In particular, we present a hardware-supported page permission framework for physical pages that is based on the concept of noninclusive sets of memory permissions for different layers of system software (such as hypervisors, operating systems, and user-level applications). Instead of viewing privilege levels as an ordered hierarchy with each successive level being more privileged, we view them as distinct levels each with its own set of permissions. In order to enable system software to manage client processes, we define a set of legal permission transitions that support resource allocation but preserve security. We show that the model prevents a range of recent attacks. We also show that it can be implemented with negligible performance overhead (both at load time and at runtime), low hardware complexity, and minimal changes to the commodity OS and hypervisor code.
Central vs. peripheral neuraxial sympathetic control of porcine ventricular electrophysiology
Authors: Yamakawa Kentaro , Howard-Quijano Kimberly , Zhou Wei , Rajendran Pradeep , Yagishita Daigo , Vaseghi Marmar , Ajijola Olujimi A. , Armour J. Andrew , Shivkumar Kalyanam , Ardell Jeffrey L. , Mahajan Aman
Published: December 2015

Sympathoexcitation is associated with ventricular arrhythmogenesis. The aim of this study was to determine the role of thoracic dorsal root afferent neural inputs to the spinal cord in modulating ventricular sympathetic control of normal heart electrophysiology. We hypothesize that dorsal root afferent input tonically modulates basal and evoked efferent sympathetic control of the heart. A 56-electrode sock placed on the epicardial ventricle in anesthetized Yorkshire pigs ( n = 17) recorded electrophysiological function, as well as activation recovery interval (ARI) and dispersion in ARI, at baseline conditions and during stellate ganglion electrical stimulation. Measures were compared between intact states and sequential unilateral T1–T4 dorsal root transection (DRTx), ipsilateral ventral root transection (VRTx), and contralateral dorsal and ventral root transections (DVRTx). Left or right DRTx decreased global basal ARI [Lt.DRTx: 369 ± 12 to 319 ± 13 ms ( P < 0.01) and Rt.DRTx: 388 ± 19 to 356 ± 15 ms ( P < 0.01)]. Subsequent unilateral VRTx followed by contralateral DRx+VRTx induced no further change. In intact states, left and right stellate ganglion stimulation shortened ARIs (6 ± 2% vs. 17 ± 3%), while increasing dispersion (+139% vs. +88%). There was no difference in magnitude of ARI or dispersion change with stellate stimulation following spinal root transections. Interruption of thoracic spinal afferent signaling results in enhanced basal cardiac sympathoexcitability without diminishing the sympathetic response to stellate ganglion stimulation. This suggests spinal dorsal root transection releases spinal cord-mediated tonic inhibitory control of efferent sympathetic tone, while maintaining intrathoracic cardiocentric neural networks.
Neuromodulatory influence of norepinephrine during developmental experience-dependent plasticity
Authors: Golovin Randall M. , Ward Nicholas J.
Published: December 2015

Critical periods represent phases of development during which neuronal circuits and their responses can be readily shaped by stimuli. Experience-dependent plasticity that occurs within these critical periods can be influenced in many ways; however, Shepard et al. ( J Neurosci 35: 2432–2437, 2015) recently singled out norepinephrine as an essential driver of this plasticity within the auditory cortex. This work provides novel insight into the mechanisms of critical period plasticity and challenges previous conceptions that a functional redundancy exists between noradrenergic and cholinergic influences on cortical plasticity.
Role of DSCAM in the development of the spinal locomotor and sensorimotor circuits
Authors: Thiry Louise , Lemieux Maxime , D. Laflamme Olivier , Bretzner Frédéric
Published: December 2015

Locomotion is controlled by spinal circuits that generate rhythm and coordinate left-right and flexor-extensor motoneuronal activities. The outputs of motoneurons and spinal interneuronal circuits are shaped by sensory feedback, relaying peripheral signals that are critical to the locomotor and postural control. Several studies in invertebrates and vertebrates have argued that the Down syndrome cell adhesion molecule (DSCAM) would play an important role in the normal development of neural circuits through cell spacing and targeting, axonal and dendritic branching, and synapse establishment and maintenance. Although there is evidence that DSCAM is important for the normal development of neural circuits, little is known about its functional contribution to spinal motor circuits. We show here that adult DSCAM2Jmutant mice, lacking DSCAM, exhibit a higher variability in their locomotor pattern and rhythm during treadmill locomotion. Retrograde tracing studies in neonatal isolated spinal cords show an increased number of spinal commissural interneurons, which likely contributes to reducing the left-right alternation and to increasing the flexor/swing duration during neonatal and adult locomotion. Moreover, our results argue that, by reducing the peripheral excitatory drive onto spinal motoneurons, the DSCAM mutation reduces or abolishes spinal reflexes in both neonatal isolated spinal cords and adult mice, thus likely impairing sensorimotor control. Collectively, our functional, electrophysiological, and anatomical studies suggest that the mammalian DSCAM protein is involved in the normal development of spinal locomotor and sensorimotor circuits.
Is the notion of central fatigue based on a solid foundation?
Authors: Contessa Paola , Puleo Alessio , De Luca Carlo J.
Published: December 2015

Exercise-induced muscle fatigue has been shown to be the consequence of peripheral factors that impair muscle fiber contractile mechanisms. Central factors arising within the central nervous system have also been hypothesized to induce muscle fatigue, but no direct empirical evidence that is causally associated to reduction of muscle force-generating capability has yet been reported. We developed a simulation model to investigate whether peripheral factors of muscle fatigue are sufficient to explain the muscle force behavior observed during empirical studies of fatiguing voluntary contractions, which is commonly attributed to central factors. Peripheral factors of muscle fatigue were included in the model as a time-dependent decrease in the amplitude of the motor unit force twitches. Our simulation study indicated that the force behavior commonly attributed to central fatigue could be explained solely by peripheral factors during simulated fatiguing submaximal voluntary contractions. It also revealed important flaws regarding the use of the interpolated twitch response from electrical stimulation of the muscle as a means for assessing central fatigue. Our analysis does not directly refute the concept of central fatigue. However, it raises important concerns about the manner in which it is measured and about the interpretation of the commonly accepted causes of central fatigue and questions the very need for the existence of central fatigue.
Mediastinal Teratoma with Neuroendocrine Features in 34-Year-Old Male with Syncope
Authors: Andrawes Peter A. , Shariff Masood A. , Chang Qing , Kong Fanyi , Rosell Frank M.
Published: December 2015

Neuroendocrine tumors that arise in an extragonadal teratoma are extremely rare. Somatic-type malignancy, defined as any sarcoma, carcinoma, leukemia, or lymphoma developing in a germ cell tumor, occurs in approximately 2% of all germ cell tumors. Our case represents a mediastinal mass that was incidentally found in a patient with syncope. Surgical resection confirmed mature teratoma with neuroendocrine features.