bluuebunny/crossref_metadata_2025 huggingface dataset:
Modelling and mapping permafrost at high spatial resolution in Wapusk National Park, Hudson Bay Lowlands1This article is one of a series of papers published in this CJES Special Issue on the theme ofFundamental and applied research on permafrost in Canada.2Earth Science Sector Contribution 20110058.
Authors: Zhang Yu , Li Junhua , Wang Xiping , Chen Wenjun , Sladen Wendy , Dyke Larry , Dredge Lynda , Poitevin Jean , McLennan Donald , Stewart Heather , Kowalchuk Sheldon , Wu Wanli , Kershaw G. Peter , Brook Ryan K.
Published: July 2012

Most spatial modelling of permafrost distribution and dynamics has been conducted at half-degree latitude/longitude or coarser resolution. Such coarse results are difficult to use for land managers and ecologists. Here we mapped permafrost distribution at 30 m × 30 m resolution for a region in the northwest Hudson Bay Lowlands using a process-based model. Land-cover types and leaf area indices were derived from Landsat imagery; peat thickness was estimated from elevation based on field measurements; and climate data were interpolated from station observations. The modelled active-layer thickness and permafrost extent compared well with field observations, demonstrating that modelling and mapping permafrost at a high spatial resolution is practical for terrains such as these lowlands. The map portrayed large variations in active-layer thickness, with land-cover type and peat thickness being the most important controlling variables. The modelled active-layer thickness on average increased by 37% during the twentieth century due to increases in air temperature and precipitation, and permafrost disappeared in some southern areas. The spatial scale of the permafrost maps developed in this study is close to that of the ecosystem and landscape features; therefore, the results are useful for land management and ecosystem assessment.
A PROSPECTIVE STUDY OF PATIENT-REPORTED OUTCOMES FOR TWO YEARS AFTER LUMBAR SURGERY AUGMENTED WITH DIAM®INTERSPINOUS IMPLANT
Authors: Crawford Rebecca J. , Malone Quentin J. , Price Roger I.
Published: July 2012

Purpose: The device for intervertebral assisted motion (DIAM™) is an interspinous (ISP) implant used to augment surgical decompression of lumbar degenerative conditions: Lumbar spinal stenosis [LSS; foraminal (FS) or central canal (CS)], herniated and degenerated disc disease, facet joint pain syndrome (FJPS) and minor degenerative spondylolisthesis (DS). Limited evidence guides its use in defined clinical indications, while few studies demonstrate effect according to clinically meaningful change (MCID). This prospective longitudinal study examined the efficacy of DIAM-augmented decompression surgery in the broad application of a single-center clinical reality. Methods: Eighty-one consecutive cases [37F, 44M; 52 years (SD 13)] were examined for two years after DIAM-augmented decompression surgery. Patient-reported pain [back and leg; visual analogue scale (VAS)], function [Oswestry disability index (ODI)], and satisfaction (Likert scale) were serially examined and referenced to contemporary MCID thresholds. Subjects were classified into anatomical and diagnostic categories and analyzed according to subgroups to better inform clinical pathways. Serial change was assessed with Scheffe post-hoc test; change scores with unpaired t-tests and descriptive statistics (p < 0.05). Results: Subjects reported 20.4% (SD 29.5; p < 0.0001) mean improvement in back pain, 20.3% (SD 30.6; p < 0.0001) in leg pain, and 15.1% (SD 20.8; p < 0.0001) in function at two years postoperatively. Greatest improvement was seen at six weeks for back pain (by 30.5%; p < 0.0001) and leg pain (by 29.4%; p < 0.0001) and three months for function (by 18.7%; p < 0.0001). Leg pain deteriorated between six weeks and 18 months (p < 0.05). There were more responders at one compared to two years after surgery. FS cases showed superior improvement compared to DS subjects (p < 0.05). Cases receiving multiple adjunctive surgical decompressions in addition to their DIAM had superior improvement than those receiving a single procedure (p < 0.05). Conclusions: Clinical improvement in back pain, leg pain and function were achieved to two years in a single-center cohort of 81 cases with lumbar degenerative disease who received DIAM-augmented decompression surgery. Subsets of the sample had a superior sustained response including foraminal/lateral recess stenosis patients and cases treated with > 1 adjunctive decompression techniques. The need for assessing homogeneous cohorts in future studies is emphasized.
TWIN CUBEFULL NUMBERS
Authors: CHAN TSZ HO
Published: July 2012

A number is cubefull if the exponent of every prime in its prime factorization is at least three. In this paper, we give, for a fixed l, the number of pairs of cubefull numbers n, n + l such that n is less than a given quantity.
ON CONGRUENCES OF THE FORM σ(n) ≡ a (modn)
Authors: ANAVI ARIA , POLLACK PAUL , POMERANCE CARL
Published: July 2012

We study the distribution of solutions n to the congruence σ(n) ≡ a ( mod n). After excluding obvious families of solutions, we show that the number of these n ≤ x is at most x½+o(1), as x → ∞, uniformly for integers a with ∣a∣ ≤ x¼. As a concrete example, the number of composite solutions n ≤ x to the congruence σ(n) ≡ 1 ( mod n) is at most x½+o(1). These results are analogues of theorems established for the Euler ϕ-function by the third-named author.
New Techniques for Noninteractive Zero-Knowledge
Authors: Groth Jens , Ostrovsky Rafail , Sahai Amit
Published: July 2012

Noninteractive zero-knowledge (NIZK) proof systems are fundamental primitives used in many cryptographic constructions, including public-key encryption secure against chosen ciphertext attack, digital signatures, and various other cryptographic protocols. We introduce new techniques for constructing NIZK proofs based on groups with a bilinear map. Compared to previous constructions of NIZK proofs, our techniques yield dramatic reduction in the length of the common reference string (proportional to security parameter) and the size of the proofs (proportional to security parameter times the circuit size). Our novel techniques allow us to answer several long-standing open questions in the theory of noninteractive proofs. We construct the first
perfect
NIZK argument system for all NP. We construct the first universally composable NIZK argument for all NP in the presence of an
adaptive
adversary. We construct a
non-interactive zap
for all NP, which is the first that is based on a standard cryptographic security assumption.
Defining Fairness in Reactive and Concurrent Systems
Authors: Völzer Hagen , Varacca Daniele
Published: July 2012

We define when a linear-time temporal property is a
fairness property
with respect to a given system. This captures the essence shared by most fairness assumptions that are used in the specification and verification of reactive and concurrent systems, such as weak fairness, strong fairness,
k
-fairness, and many others. We provide three characterizations of fairness: a language-theoretic, a game-theoretic, and a topological characterization. It turns out that the fairness properties are the sets that are “large” from a topological point of view, that is, they are the
co-meager
sets in the natural topology of runs of a given system.

This insight provides a link to probability theory where a set is “large” when it has measure 1. While these two notions of largeness are similar, they do not coincide in general. However, we show that they coincide for
ω
-regular properties and bounded Borel measures. That is, an
ω
-regular temporal property of a finite-state system has measure 1 under a bounded Borel measure if and only if it is a fairness property with respect to that system.

The definition of fairness leads to a generic relaxation of correctness of a system in linear-time semantics. We define a system to be
fairly correct
if there exists a fairness assumption under which it satisfies its specification. Equivalently, a system is fairly correct if the set of runs satisfying the specification is topologically large. We motivate this notion of correctness and show how it can be verified in a system.
The Power of Simple Tabulation Hashing
Authors: Pǎtraşcu Mihai , Thorup Mikkel
Published: July 2012

Randomized algorithms are often enjoyed for their simplicity, but the hash functions used to yield the desired theoretical guarantees are often neither simple nor practical. Here we show that the simplest possible tabulation hashing provides unexpectedly strong guarantees.

The scheme itself dates back to Zobrist in 1970 who used it for game playing programs. Keys are viewed as consisting of
c
characters. We initialize
c
tables
H
1, ...,
H
c
mapping characters to random hash codes. A key
x
 = (
x
1
, ...,
x
c
) is hashed to
H
1[
x
1] ⊕ ⋯ ⊕ 
H
c
[
x
c
], where ⊕ denotes bit-wise exclusive-or.

While this scheme is not even 4-independent, we show that it provides many of the guarantees that are normally obtained via higher independence, for example, Chernoff-type concentration, min-wise hashing for estimating set intersection, and cuckoo hashing.
Book announcement:
Human Computation
Authors: Law Edith , Von Ahn Luis
Published: July 2012

We announce our book,
Human Computation
, published in August 2011 in the Morgan & Claypool Synthesis Series on Artificial Intelligence and Machine Learning. Our announcement is based on the preface of the book.
On Bitcoin and red balloons
Authors: Babaioff Moshe , Dobzinski Shahar , Oren Sigal , Zohar Aviv
Published: July 2012

In this letter we present a brief report of our recent research on information distribution mechanisms in networks [Babaioff et al. 2011]. We study scenarios in which all nodes that become aware of the information compete for the same prize, and thus have an incentive
not
to propagate information.

Examples of such scenarios include the 2009 DARPA Network Challenge (finding red balloons), and raffles. We give special attention to one application domain, namely Bitcoin, a decentralized electronic currency system. We propose reward schemes that will remedy an incentives problem in Bitcoin in a Sybil-proof manner, with little payment overhead.
Optimal pricing in social networks
Authors: Candogan Ozan , Bimpikis Kostas , Ozdaglar Asuman
Published: July 2012

We consider the pricing strategies of a monopolist selling a divisible good (service) to consumers who are embedded in a social network. We assume that each consumer's usage level depends directly on the usage of her neighbors in the social network, and investigate the optimal pricing policies of the monopolist. We show that if the monopolist can perfectly price discriminate the agents, then the price offered to each agent has three components: a nominal price, a discount term due to the agent's influence on her neighbors, and a markup term due to the influence of her neighbors on the agent. We also characterize the optimal pricing strategies in settings where the monopolist is constrained to offering a single price, and where she can choose two distinct prices (a discounted and a full price). For the former setting we provide a polynomial time algorithm for the solution of the pricing problem. On the other hand, we show that in the latter setting the optimal pricing problem is NP-hard, and we provide an approximation algorithm, which, under some conditions, achieves at least 88% of the maximum profit.
Stability and competitive equilibrium in matching markets with transfers
Authors: Hatfield John William , Kominers Scott Duke
Published: July 2012

This note surveys recent work in generalized matching theory, focusing on trading networks with transferable utility. In trading networks with a finite set of contractual opportunities, the substitutability of agents' preferences is essential for the guaranteed existence of stable outcomes and the correspondence of stable outcomes with competitive equilibria. Closely analogous results hold when venture participation is continuously adjustable, but under a concavity condition on agents' preferences which allows for some types of complementarity.
Solution to exchanges 10.1 puzzle
Authors: McAfee Preston
Published: July 2012

Puzzle Editor's Note: This is the winning solution to
Baffling Raffling
from issue 10.1. The mechanism described there is sometimes known as a Chinese Auction. It is also equivalent, as McAfee points out, to a special case of a Cournot problem. An alternative formulation is: I decide a bid
x
, pay it in full, and then win the good with probability
x/X
where
X
is the sum of all the bids. Generalizing the question in the original puzzle, this solves the game for an arbitrary vector of common-knowledge valuations, i.e., the complete-information case with
n
agents.
Buying private data at auction
Authors: Roth Aaron
Published: July 2012

In this letter, we survey some recent work on what we call the
sensitive surveyor's problem
. A curious data analyst wishes to survey a population to obtain an accurate estimate of a simple population statistic: for example, the fraction of the population testing positive for syphilis. However, because this is a statistic over sensitive data, individuals experience a cost for participating in the survey as a function of their loss in privacy. Agents must be compensated for this cost, and moreover, are strategic agents and will mis-report their cost if doing so is beneficial for them. The goal of the surveyor is to manage the inevitable tradeoff between the cost of the survey, and the accuracy of its results.
The price of anarchy in games of incomplete information
Authors: Roughgarden Tim
Published: July 2012

We outline a recently developed theory for bounding the inefficiency of equilibria in games of incomplete information, with applications to auctions and routing games.
How to approximate optimal auctions
Authors: Haghpanah Nima , Immorlica Nicole , Mirrokni Vahab , Munagala Kamesh
Published: July 2012

Bayesian auction design investigates how to sell scarce resources to agents with private values drawn according to known distributions. A natural objective in this setting is revenue maximization. The seminal work of Roger Myerson presents a recipe for designing revenue-maximizing auctions in single-parameter settings. Myerson defines a function that maps each agent's value to a new number called the
virtual value
. The optimal auction then chooses the solution with maximum virtual surplus subject to the feasibility constraints. Often this underlying optimization problem is NP-hard and is complicated by the fact that virtual values may be negative. Prior work approximates the optimal auction by approximating this optimization problem. Such a solution can be interpreted as approximating the optimal auction point-wise, i.e., for each realization of values the revenue of the derived auction is close to that of the Myerson auction. In this letter, we suggest a different approach:

Approximate the maximum virtual surplus on average with respect to the induced virtual value distributions
.

Our approach has the advantage that sometimes the point-wise optimization problem is not approximable to within any reasonable factor. However, by leveraging the fact that any distribution of virtual values has non-negative expectation, it is sometimes possible to get good average-case approximations. Furthermore, the optimal auction is itself an average-case guarantee: it maximizes the revenue on average with respect to the distributions, but it may lose substantial revenue on certain value profiles. Thus our average-case guarantee is without loss of generality.

We showcase our approach using the problem of selling goods with positive network externalities. For this problem, the underlying optimization problem is inapproximable, yet with our approach we are able to prove that a natural greedy auction is a constant-factor approximation.
Solution to exchanges 10.2 puzzle
Authors: Shorrer Ran I.
Published: July 2012

This is a solution to the editor's puzzle from issue 10.2 of SIGecom Exchanges [Reeves 2011]. The Puzzle asks to determine a point in time such that a lump sum payment of $S will be equivalent to a continuous stream of infinitesimal payments totaling $S, spread evenly over time. The full puzzle can be found online at: http://www.sigecom.org/exchanges/volume_10/2/puzzle.pdf.
A mechanistic analysis of the role of microcalcifications in atherosclerotic plaque stability: potential implications for plaque rupture
Authors: Maldonado Natalia , Kelly-Arnold Adreanne , Vengrenyuk Yuliya , Laudier Damien , Fallon John T. , Virmani Renu , Cardoso Luis , Weinbaum Sheldon
Published: July 2012

The role of microcalcifications (μCalcs) in the biomechanics of vulnerable plaque rupture is examined. Our laboratory previously proposed (Ref. 44 ), using a very limited tissue sample, that μCalcs embedded in the fibrous cap proper could significantly increase cap instability. This study has been greatly expanded. Ninety-two human coronary arteries containing 62 fibroatheroma were examined using high-resolution microcomputed tomography at 6.7-μm resolution and undecalcified histology with special emphasis on calcified particles <50 μm in diameter. Our results reveal the presence of thousands of μCalcs, the vast majority in lipid pools where they are not dangerous. However, 81 μCalcs were also observed in the fibrous caps of nine of the fibroatheroma. All 81 of these μCalcs were analyzed using three-dimensional finite-element analysis, and the results were used to develop important new clinical criteria for cap stability. These criteria include variation of the Young's modulus of the μCalc and surrounding tissue, μCalc size, and clustering. We found that local tissue stress could be increased fivefold when μCalcs were closely spaced, and the peak circumferential stress in the thinnest nonruptured cap (66 μm) if no μCalcs were present was only 107 kPa, far less than the proposed minimum rupture threshold of 300 kPa. These results and histology suggest that there are numerous μCalcs < 15 μm in the caps, not visible at 6.7-μm resolution, and that our failure to find any nonruptured caps between 30 and 66 μm is a strong indication that many of these caps contained μCalcs.
Focal but reversible diastolic sheet dysfunction reflects regional calcium mishandling in dystrophicmdxmouse hearts
Authors: Cheng Ya-Jian , Lang Di , Caruthers Shelton D. , Efimov Igor R. , Chen Junjie , Wickline Samuel A.
Published: July 2012

Cardiac dysfunction is a primary cause of patient mortality in Duchenne muscular dystrophy, potentially related to elevated cytosolic calcium. However, the regional versus global functional consequences of cellular calcium mishandling have not been defined in the whole heart. Here we sought for the first time to elucidate potential regional dependencies between calcium mishandling and myocardial fiber/sheet function as a manifestation of dystrophin-deficient ( mdx) cardiomyopathy. Isolated-perfused hearts from 16-mo-old mdx ( N = 10) and wild-type (WT; N = 10) were arrested sequentially in diastole and systole for diffusion tensor MRI quantification of myocardial sheet architecture and function. When compared with WT hearts, mdx hearts exhibited normal systolic sheet architecture but a lower diastolic sheet angle magnitude (|β|) in the basal region. The regional diastolic sheet dysfunction was normalized by reducing perfusate calcium concentrations. Optical mapping of calcium transients in isolated hearts (3 mdx and 4 WT) revealed a stretch-inducible regional defect of intracellular calcium reuptake, reflected by a 25% increase of decay times ( T50) and decay constants, at the base of mdx hearts. The basal region of mdx hearts also exhibited greater fibrosis than did the apex, which matched the regional sheet dysfunction. We conclude that myocardial diastolic sheet dysfunction is observed initially in basal segments along with calcium mishandling, ultimately culminating in increased fibrosis. The preservation of relatively normal calcium reuptake and diastolic/systolic sheet mechanics throughout the rest of the heart, together with the rapid reversibility of functional defects by reducing cytosolic calcium, points to the significance of regional mechanical factors in the progression of the disease.
Extraskeletal Chondroma of the Preauricular Region: A Case Report and Literature Review
Authors: Watanabe Futoshi , Saiki Tadahiko , Ochochi Yoshihisa
Published: July 2012

An extraskeletal chondroma is a rare benign cartilaginous tumor that develops in soft tissue. Histologically, it is a lobulated nodule surrounded by a fibrous capsule; the inside consists of mature hyaline cartilage containing a few normal chondrocytes. We present a rare case of extraskeletal chondroma in the preauricular region. A 43-year-old man presented with a 2-cm-diameter right preauricular tumor that had been developing for 1 year. Magnetic resonance imaging showed a solid lobulated tumor in the right preauricular region, which was proximate to the capsule of the right temporomandibular joint (TMJ). This was subsequently resected under general anesthesia. The tumor was not in contact with the TMJ capsule and had not invaded the surrounding tissue, facilitatingen blocexcision. Histopathologically, the tumor comprised mainly of hyaline cartilage containing chondrocytes with chondrocytic lacunae and was diagnosed as a chondroma. The postoperative period was uneventful, and there was no evidence of recurrence at the 2-year followup. We describe the clinical characteristics of our case and review the literature, emphasizing the differential diagnosis.
Recent Developments of Reflectarray Antennas in Dual-Reflector Configurations
Authors: Tienda Carolina , Arrebola Manuel , Encinar José A.
Published: July 2012

Recent work on dual-reflector antennas involving reflectarrays is reviewed in this paper. Both dual-reflector antenna with a reflectarray subreflector and dual-reflectarrays antennas with flat or parabolic main reflectarray are considered. First, a general analysis technique for these two configurations is described. Second, results for beam scanning and contoured-beam applications in different frequency bands are shown and discussed. The performance and capabilities of these antennas are shown by describing some practical design cases for radar, satellite communications, and direct broadcast satellite (DBS) applications.
Factors Associated with Diabetic Retinopathy in Chinese Patients with Type 2 Diabetes Mellitus
Authors: He Bin-Bin , Wei Li , Gu Yun-Juan , Han Jun-Feng , Li Ming , Liu Yu-Xiang , Bao Yu-Qian , Jia Wei-Ping
Published: July 2012

Objective.To investigate the risk factors of DR in Chinese T2DM patients.Methods.2009 patients with T2DM were included in this cross-sectional study. All patients underwent eye examination, and the DR stage was defined by an ophthalmologist. Correlation analysis was performed to evaluate the relation between DR and clinical variables. Logistic regression models were used to assess risk for those factors associated with DR.Results.A total of 597 T2DM patients (29.7%) had DR, of which 548 (27.3%) were nonproliferative diabetic retinopathy and 49 (2.4%) were proliferative diabetic retinopathy. Positive correlations were found between DR and duration of diabetes, systolic blood pressure (SBP), diastolic blood pressure, glycated hemoglobin, glycated albumin, 24 hurinary albumin excretion, peripheral atherosclerosis (PA), diabetes nephropathy (DN), diabetic peripheral neuropathy, and anemia. Negative correlations were found between DR and C-peptide and glomerular filtration rate. Logistic regression analysis revealed that duration of diabetes, SBP, DN, anemia, PA, and C-peptide were each independent risk factors of DR.Conclusion.The duration of diabetes, SBP, DN, anemia, and PA are positively associated with DR in Chinese T2DM patients, while C-peptide is negatively associated with DR. Monitoring and evaluation of these related factors will likely contribute to the prevention and treatment of DR.
Polishing Sapphire Substrates by 355 nm Ultraviolet Laser
Authors: Wei X. , Xie X. Z. , Hu W. , Huang J. F.
Published: July 2012

This paper tries to investigate a novel polishing technology with high efficiency and nice surface quality for sapphire crystal that has high hardness, wear resistance, and chemical stability. A Q-switched 355 nm ultraviolet laser with nanosecond pulses was set up and used to polish sapphire substrate in different conditions in this paper. Surface roughnessRaof polished sapphire was measured with surface profiler, and the surface topography was observed with scanning electronic microscope. The effects of processing parameters as laser energy, pulse repetition rate, scanning speed, incident angle, scanning patterns, and initial surface conditions on surface roughness were analyzed.
Diagnosing Patients with Age-Related Hearing Loss and Tinnitus: Supporting GP Clinical Engagement through Innovation and Pathway Redesign in Audiology Services
Authors: Davis Adrian , Smith Pauline A. , Booth Michelle , Martin Margaret
Published: July 2012

The public health challenge of hearing impairment is growing, as age is the major determinant of hearing loss. Almost one in four (22.6%) over 75-year olds reports moderate or severe worry because of hearing problems. There is a 40% comorbidity of tinnitus and balance disorders. Good outcomes depend on early presentation and appropriate referral. This paper describes how the NHS Improvement Programme in England used service improvement methodologies to identify referral pathways and tools which were most likely to make significant improvements in diagnosing hearing loss, effective referrals and better patient outcomes. An audiometric screening device was used in GP surgeries to enable thresholds for effective referrals to be measured in the surgery. Revised referral criteria, the use of this device, new “assess and fit” technology in the audiology clinic, and direct access pathways can transform audiology service delivery so that patient outcomes are measurably better. This, in turn, changes the experience of GPs, so they are more likely to refer patients who can benefit from treatment. At the end of 2011, 51 GP practices in one of the audiology pilot areas had bought HearCheck screeners, a substantial development from the 4 practices who first engaged with the pilot.
Convenient and Scalable Synthesis of Fmoc-Protected Peptide Nucleic Acid Backbone
Authors: Feagin Trevor A. , Shah Nirmal I. , Heemstra Jennifer M.
Published: July 2012

The peptide nucleic acid backbone Fmoc-AEG-OBn has been synthesized via a scalable and cost-effective route. Ethylenediamine is mono-Boc protected, then alkylated with benzyl bromoacetate. The Boc group is removed and replaced with an Fmoc group. The synthesis was performed starting with 50 g of Boc anhydride to give 31 g of product in 32% overall yield. The Fmoc-protected PNA backbone is a key intermediate in the synthesis of nucleobase-modified PNA monomers. Thus, improved access to this molecule is anticipated to facilitate future investigations into the chemical properties and applications of nucleobase-modified PNA.
Resonant Frequency Calculation and Optimal Design of Peano Fractal Antenna for Partial Discharge Detection
Authors: Li Jian , Cheng Changkui , Bao Lianwei , Jiang Tianyan
Published: July 2012

Ultra-high-frequency (UHF) approaches have caught increasing attention recently and have been considered as a promising technology for online monitoring partial discharge (PD) signals. This paper presents a Peano fractal antenna for UHF PD online monitoring of transformer with small size and multiband. The approximate formula for calculating the first resonant frequency of the Peano fractal antenna is presented. The results show that the first resonant frequency of the Peano fractal antenna is smaller than the Hilbert fractal antenna when the outer dimensions are equivalent approximately. The optimal geometric parameters of the antenna were obtained through simulation. Actual PD experiments had been carried out for two typically artificial insulation defect models, while the proposed antenna and the existing Hilbert antenna were both used for the PD measurement. The experimental results show that Peano fractal antenna is qualified for PD online UHF monitoring and a little more suitable than the Hilbert fractal antenna for pattern recognition by analyzing the waveforms of detected UHF PD signals.
Immunological HCV-Associated Thrombocytopenia: Short Review
Authors: Dimitroulis Dimitrios , Valsami Serena , Stamopoulos Paraskevas , Kouraklis Gregory
Published: July 2012

Infection with Hepatitis C virus (HCV) is affecting about 3% of the world's population, leading to liver damage, end-stage liver disease, and development of hepatocellular carcinoma, being thus the first indication for liver transplantation in the USA. Apart from the cirrhotic-liver-derived clinical signs and symptoms several conditions with immunological origin can also arise, such as, glomerulonephritis, pulmonary fibrosis, and thrombocytopenia. HCV-related autoimmune thrombocytopenia shows specific pathogenetic characteristics as well as symptoms and signs that differ in severity and frequency from symptoms in patients that are not HCV infected. Aim of this short paper is to estimate the epidemiological characteristics of the disease, to investigate the pathogenesis and clinical manifestation, and to propose treatment strategies according to the pertinent literature.
Highly Stable and Active Pt/Nb-TiO2Carbon-Free Electrocatalyst for Proton Exchange Membrane Fuel Cells
Authors: Sun Shuhui , Zhang Gaixia , Sun Xueliang , Cai Mei , Ruthkosky Martin
Published: July 2012

The current materials used in proton exchange membrane fuel cells (PEMFCs) are not sufficiently durable for commercial deployment. One of the major challenges lies in the development of an inexpensive, efficient, and highly durable and active electrocatalyst. Here a new type of carbon-free Pt/Nb-TiO2electrocatalyst has been reported. Mesoporous Nb-TiO2hollow spheres were synthesized by the sol-gel method using polystyrene (PS) sphere templates. Pt nanoparticles (NPs) were then deposited onto mesoporous Nb-TiO2hollow spheres via a simple wet-chemical route in aqueous solution, without the need for surfactants or potentiostats. The growth densities of Pt NPs on Nb-TiO2supports could be easily modulated by simply adjusting the experimental parameters. Electrochemical studies of Pt/Nb-TiO2show much enhanced activity and stability than commercial E-TEK Pt/C catalyst. PtNP/Nb-TiO2is a promising new cathode catalyst for PEMFC applications.
Environmental and Material Influences on the Stress-Corrosion Cracking of Steel in H2O–CO–CO2Solutions
Authors: Merwe J. W. van der
Published: July 2012

The stress-corrosion cracking of A516 pressure vessel steel was investigated by the use of slow strain-rate tests. The orientation of samples to the rolling direction was investigated, and it was found that samples machined longitudinal to the rolling direction showed a slightly increased sensitivity to stress corrosion. The temperature variation showed that for different gas mixtures, the maximum sensitivity to stress corrosion was in the region of 45° to 55°C for the 25% CO gas mixture, whereas with higher CO concentrations, this temperature region of maximum sensitivity moved to higher temperatures. Surface finish showed a slight increase in sensitivity to cracking with increased surface roughness. The most significant increase was found with increased total gas pressures and when samples have been exposed to the environment for an extended period. This was as a result of the inhibition of the corrosion reaction by the passivation of the carbon monoxide, which is a time-dependent process.
Preventive Treatments of Iron Deficiency Anaemia in Pregnancy: A Review of Their Effectiveness and Implications for Health System Strengthening
Authors: Osungbade Kayode O. , Oladunjoye Adeolu O.
Published: July 2012

Objectives. We conducted a review of effectiveness of preventive treatments of iron deficiency anaemia in pregnancy in developing countries and highlighted their constraints as well as interventions required to strengthen the health services.Methods. Literature from Pubmed (MEDLINE), AJOL, Google Scholar, and Cochrane database was reviewed.Results. Evidence-based preventive treatment options for iron deficiency anaemia in pregnancy include prophylaxis iron supplements and food fortification with iron. Evidence abounds on their effectiveness in reducing the prevalence of iron deficiency anaemia in pregnancy. However, these prospects are threatened by side effects of iron supplements, low utilization of maternal health service in developing countries, partial implementation of preventive treatments, and weak infrastructure and political commitment to implement mass fortification of local staple foods by national governments.Conclusion. Sustainability of effectiveness of preventive treatments of iron deficiency anaemia in pregnancy could be achieved if the identified threats are adequately addressed.
Occult Spinal Dysraphism in Obstetrics: A Case Report of Caesarean Section with Subarachnoid Anaesthesia after Remifentanil Intravenous Analgesia for Labour
Authors: Valente A. , Frassanito L. , Natale L. , Draisci G.
Published: July 2012

Neuraxial techniques of anaesthesia and analgesia are the current choice in obstetrics for efficacy and general low risk of major complications. Concern exists about neuraxial anaesthesia in patients with occult neural tube defects, regarding both labour analgesia and anaesthesia for Caesarean section. Recently, remifentanil infusion has been proposed as an analgesic technique alternative to lumbar epidural, especially when epidural analgesia appears to be contraindicated. Here, we discuss the case of a pregnant woman attending at our institution with occult, symptomatic spinal dysraphism who requested labour analgesia. She was selected for remifentanil intravenous infusion for labour pain and then underwent urgent operative delivery with spinal anaesthesia with no complications.
Challenges Found When Patterning Semiconducting Polymers with Electric Fields for Organic Solar Cell Applications
Authors: de Castro Fernando A. , Nüesch Frank , Walder Christian , Hany Roland
Published: July 2012

A material‐independent, contactless structuring method of semiconducting organic materials for the fabrication of interface‐enhanced bilayer solar cells is not available so far. Patterning of thin films using electrohydrodynamic instabilities possesses many desired characteristics and has convincingly been used as a simple method to structure and replicate patterns of nonconducting polymers on submicrometer length scales. However, the applicability of this technique to a wider range of materials has not been demonstrated yet. Here, we report attempts to structure poly(p‐phenylene vinylene) in a similar way. We found that thin films of poly(2‐methoxy‐5‐(2′‐ethylhexyl‐oxy)‐1,4‐phenylene‐vinylene) (MEH‐PPV) and poly(2‐methoxy‐5‐(3′,7′‐dimethyloctyloxy)‐1,4‐phenylene‐vinylene) (MDMO‐PPV) could not be destabilized at all in the limited accessible range of the experimental parameters set by the delicate chemical nature of these materials. We discuss failure origins and present possible loopholes for the patterning of semiconducting polymers using electric fields.
Hepatitis C Virus Infection and Mixed Cryoglobulinemia
Authors: Lauletta Gianfranco , Russi Sabino , Conteduca Vincenza , Sansonno Loredana
Published: July 2012

Hepatitis C virus (HCV) chronic infection is recognized as the major cause of mixed cryoglobulinemia (MC). Its persistence represents a continuous stimulus for host immune system with production of circulating immune complexes (ICs), one-third of them with cryoprecipitate property. Several factors contribute to the biological activities of ICs, many of which are not completely known. Among them, complement factors play a crucial role in the cold-insoluble ICs-mediated vasculitis, involving primarily small blood vessels in different tissues including skin, kidney, peripheral, and central nervous system. Liver represents the major target of HCV infection with inflammatory infiltrates, resembling secondary lymphoid follicles. Cytokine like CXCL13 contribute to B-cell homing in intraportal lymphoid aggregates, in which B-cell clonal selection may arise. B-cell clonal expansion starts as an antigen-driven event and expands towards indolent and malignant B-cell proliferation. Occurrence of intrahepatic B-cell clonalities correlates with extrahepatic clinical manifestations of HCV infection. In this context, cryoglobulinemic patients should be considered a peculiar HCV-infected population that needs a clinical multidisciplinary approach and more articulated therapeutic measures.
Management of Unilateral Masseter Hypertrophy and Hypertrophic Scar—A Case Report
Authors: Shetty Naresh , Malaviya Rajanikanth K. , Gupta M. K.
Published: July 2012

Masseter muscle hypertrophy is a rare condition of idiopathic cause. It clinically presents as an enlargement of one or both masseter muscles. Most patients complain of facial asymmetry; however, symptoms such as trismus, protrusion, and bruxism may also occur. Several treatment options reported for masseter hypertrophy are present, which range from simple pharmacotherapy to more invasive surgical reduction. Keloid scar with unilateral masseter hypertrophy is a rarely seen in clinical practice. This paper reports a case of unilateral masseter hypertrophy with keloid scar in the angle of the mandible for which surgical treatment was rendered to the patient by using a single approach.
Enhancement of Polymer Cytocompatibility by Nanostructuring of Polymer Surface
Authors: Slepička Petr , Slepičková Kasálková Nikola , Bačáková Lucie , Kolská Zdeňka , Švorčík Václav
Published: July 2012

Polymers with their advantageous physical, chemical, mechanical, and electrical properties and easy manufacturing are widely used in biology, tissue engineering, and medicine, for example, as prosthetic materials. In some cases the polymer usage may be impeded by low biocompatibility of common synthetic polymers. The biocompatibility can be improved by modification of polymer surface, for example, by plasma discharge, irradiation with ionizing radiation, and sometime subsequent grafting with suitable organic (e.g., amino‐acids) or inorganic (e.g., gold nanoparticles) agents. In this way new chemically active structures are created on the polymer surface, and in some cases new surface relief is created. Recent advances in nanotechnology and in characterization of nanostructured objects open the way to development of new polymer‐based materials with better bio‐properties and higher application potential in biomedicine. Some of recent results obtained in the field are summarized and discussed in this paper.
Research on Fire Resistance of Ultra-High-Performance Concrete
Authors: Ye Hao-wen , Feng Nai-qian , Ling-hu Yan , Ran Zhi-wei , Lin Li-xun , Qi Shi-kun , Dong Yi
Published: July 2012

Fire resistance of ultrahigh-performance concrete was measured under different temperatures and loadings. C120 concrete was prepared with 1 kg/m3organic fiber and C120 concrete with 2 kg/m3organic fiber and tested under loading at 30% ultimate strength when exposed to high temperatures of 200°C, 300°C, and 400°C, respectively.
Chaotic Synchronization in a Small Network of a Class of PowerSystems via Contraction Analysis
Authors: Solís-Perales G. , Ruiz-Velázquez E. , García-Rodríguez J. A.
Published: July 2012

This paper presents a synchronization analysis of networks of a class of power systems using the contraction theory for nonlinear systems. This analysis is characterized by not being based on Lyapunov′s stability theory, that is, it is not required to determine a Lyapunov candidate function. Moreover, from the contraction conditions, robustness of the synchronization can be obtained, in this sense, the analysis method is robust. The analysis consists in identifying or proposing a virtual or auxiliary system which is contracting in a region of the state space. It is intended that in this region the trajectories of the systems on the network converge to those of the virtual system and then obtain the synchronization of the systems in the network. The contribution consists in applying this nontraditional analysis to the problem of chaotic synchronization of a network of a class of power systems.
Comparison of the Triage Micro Parasite Panel and Microscopy for the Detection ofEntamoeba histolytica/Entamoeba dispar,Giardia lamblia, andCryptosporidium parvumin Stool Samples Collected in Kenya
Authors: Swierczewski Brett , Odundo Elizabeth , Ndonye Janet , Kirera Ronald , Odhiambo Cliff , Oaks Edwin
Published: July 2012

Entamoeba histolytica,Giardia lamblia, andCryptosporidium parvumare three of the most important parasitic causes of acute diarrhea worldwide. Laboratory diagnosis of these parasites is usually done by ova and parasite examination (O&P examination) via microscopy. The sensitivity and specificity of O&P examination varies among laboratories and can be labor intensive and time consuming. The Triage Micro Parasite Panel (BioSite, San Diego, California) is an enzyme immunoassay kit that can detectE. histolytica/E. dispar,G. lamblia, andC. parvumsimultaneously using fresh or frozen stool. The present study evaluated the Triage Micro Parasite Panel in detectingE. histolytica/E. dispar,G. lamblia, andC. parvumcompared to O&P examination in 266 stool samples collected at medical facilities in Kenya. The sensitivity and specificity results for the Triage Micro Parasite Panel were: forE. histolytica/E. dispar: 100%, 100%,G. lamblia: 100%, 100% andC. parvum: 73%, 100%. There was no evidence of cross reactivity using the kit with other parasites identified in the stool specimens. These results indicate that the Triage Micro Parasite Panel is a highly sensitive kit that can be used for screening purposes in large scale studies or outbreak investigations or as a possible alternative to O&P examination.
Malignant Mixed Mullerian Tumor: An Immunohistochemical Study
Authors: Bing Zhanyong , Pasha Theresa , Wang Li-Ping , Zhang Paul J.
Published: July 2012

Malignant mixed Mullerian tumor (MMMT) is an uncommon aggressive neoplasm composed of both malignant epithelial and mesenchymal components. In this study, immunohistochemical stains of germ cell markers, including SALL4, OCT3/4, glypican-3, and alpha-fetal protein (AFP), and CDX2 were performed in a series of MMMTs. SALL4 nuclear immunoreactivity was detected in 6 out of 19 cases (33%). The staining extent ranged from focal to extensive. The staining intensity was usually intermediate to strong (the score ranged from 1.5 to 3, and average score was 2.3 ± 0.5 in the positive cases). In addition, glypican-3 cytoplasmic reactivity was detected in 14 out of 16 cases (88%) with a mean score of 1.8 ± 0.7 (score ranging from 1 to 3). In contrast, OCT3/4 was only positive in 1 out of 19 cases and AFP in 2 out of 18 cases (11%). In summary, SALL4 and glypican-3 were frequently expressed in a subset of MMMTs. Their roles in the pathogenesis and biology of MMMT are yet to be determined. MMMT should be included in the differential diagnosis when a tumor is positive for SALL4 and/or glypican-3.
A Case ofBrucellaEndocarditis in Association with Subclavian Artery Thrombosis
Authors: Colomba Claudia , Siracusa Lucia , Rubino Raffaella , Trizzino Marcello , Scarlata Francesco , Imburgia Claudia , Titone Lucina
Published: July 2012

Brucellosis is a common zoonosis, endemic in Mediterranean countries, and caused by bacteria ofBrucellagenus. Brucellosis is a systemic infection and the clinical presentation varies widely from asymptomatic and mild to severe disease. Cardiovascular complications are extremely rare. We present a case of arterial thrombosis in a previously healthy young patient withBrucellaendocarditis. Careful attention must be paid to any sign or symptom of thrombosis in patients affected by brucellosis, regardless of the presence of endocarditis and cardiovascular risk factors.
Targeting Metabolism and Autophagy in the Context of Haematologic Malignancies
Authors: Banerji Versha , Gibson Spencer B.
Published: July 2012

Autophagy is a cellular process that maintains the homeostasis of the normal cell. It not only allows for cell survival in times of metabolic stress with nutrient recycling but also is able to lead to cell death when required. During malignant transformation the cell is able to proliferate and survive. This is due to altered cell metabolism and the presence of altered genetic changes that maintain the cell survival. Metabolism was considered an innocent bystander that was a consequence of the increased nutrient requirement for the survival and proliferation of haematological malignancies. The interdependency of metabolism and cellular mechanisms such as autophagy are becoming more evident and important. This interdependence contributes to increased cancer progression and drug resistance. In this paper we aim to discuss autophagy, how it pertains to metabolism in the context of hematologic malignancies, and the implications for therapy.
Time-Domain Predistortion Method Based on Raised Cosine Signaling in Real Transmission Channels
Authors: Sevcik Bretislav
Published: July 2012

The concept of time-domain predistortion method based on raised cosine signaling is applied in real transmission channels. The proposed PWM-RC method uses raised-cosine pulse shaping instead of conventional rectangular digital signals and pulse-width modulation (PWM) scheme to achieve better output channel data response in harsh channel environment. The conventional predistortion methods based on pulse amplitude adjusting are not compatible with modern low-power CMOS design. Currently existing time-domain predistortion methods which are only based on a PWM scheme show many highfrequency signal harmonic components for both fast and slow signal transitions. It can cause more system crosstalk susceptibility if the crosstalk is dominant factor in transmission channel. In this case, the additional preemphasis boosted undesirable high-frequency components. Finally, the real channel transfer functions in connection with ADS Agilent development studio are used to compare the performance of proposed method with other predistortion methods.
Modeling of GPR Clutter Caused by Soil Heterogeneity
Authors: Takahashi Kazunori , Igel Jan , Preetz Holger
Published: July 2012

In small-scale measurements, ground-penetrating radar (GPR) often uses a higher frequency to detect a small object or structural changes in the ground. GPR becomes more sensitive to the natural heterogeneity of the soil when a higher frequency is used. Soil heterogeneity scatters electromagnetic waves, and the scattered waves are in part observed as unwanted reflections that are often referred to as clutter. Data containing a great amount of clutter are difficult to analyze and interpret because clutter disturbs reflections from objects of interest. Therefore, modeling GPR clutter is useful to assess the effectiveness of GPR measurements. In this paper, the development of such a technique is discussed. This modeling technique requires the permittivity distribution of soil (or its geostatistical properties) and gives a nominal value of clutter power. The paper demonstrates the technique with the comparison to the data from a GPR time-lapse measurement. The proposed technique is discussed in regard to its applicability and limitations based on the results.
Best Proximity Point Theorems for Some New Cyclic Mappings
Authors: Chen Chi-Ming , Chen Chao-Hung
Published: July 2012

By using the stronger Meir‐Keeler mapping, we introduce the concepts of the sMK‐G‐cyclic mappings, sMK‐K‐cyclic mappings, and sMK‐C‐cyclic mappings, and then we prove some best proximity point theorems for these various types of contractions. Our results generalize or improve many recent best proximity point theorems in the literature (e.g., Elderd and Veeramani, 2006; Sadiq Basha et al., 2011).