bluuebunny/crossref_metadata_2025 huggingface dataset:
Controlling the Biodegradation of Magnesium Implants Through Nanostructured Coatings
Authors: Iskandar Maria E. , Lock Jaclyn Y. , Aslani Arash , Liu Huinan
Published: August 2012

Magnesium (Mg) alloys, a novel class of degradable, metallic biomaterials, have attracted growing interest as a promising alternative for medical implant and device applications due to their advantageous mechanical and biological properties. Moreover, magnesium is biodegradable in the physiological environments. The major obstacle for Mg to be used as medical implants is its rapid degradation in physiological fluids. Therefore, the present key challenge lies in controlling Mg degradation rate in the physiological environment. The objective of this study is to develop a nanostructured-hydroxyapatite (nHA) coating on Mg implants to control the degradation and bone tissue integration of the implants. Nanostructured-HA coatings are deposited on magnesium using the Spire’s patented TPA process to moderate the aggressive degradation of magnesium and to improve fast osteointegration between magnesium and natural bone. Morphology and element compositions were characterized using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analysis. The degradation of nHA coated Mg and uncoated Mg was investigated by incubating samples in phosphate buffered saline (PBS) under standard cell culture conditions. The degradation results suggest the nanocoatings positively mediated magnesium degradation. Therefore, nHA coatings are promising for controlling the biodegradation of magnesium-based orthopedic implants and devices.
Numerical Investigation of Pulsed Chemical Vapor Deposition of Aluminum Nitride to Reduce Particle Formation
Authors: Endres Derek , Mazumder Sandip
Published: August 2012

Particles of aluminum nitride (AlN) have been observed to form during epitaxial growth of AlN films by metal organic chemical vapor deposition (MOCVD). Particle formation is undesirable because particles do not contribute to the film growth, and are detrimental to the hydraulic system of the reactor. It is believed that particle formation is triggered by adducts that are formed when the group-III precursor, namely tri-methyl-aluminum (TMAl), and the group-V precursor, namely ammonia (NH3), come in direct contact in the gas-phase. Thus, one way to eliminate particle formation is to prevent the group-III and the group-V precursors from coming in direct contact at all in the gas-phase. In this article, pulsing of TMAl and NH3 is numerically investigated as a means to reduce AlN particle formation. The investigations are conducted using computational fluid dynamics (CFD) analysis with the inclusion of detailed chemical reaction mechanisms both in the gas-phase and at the surface. The CFD code is first validated for steady-state (non-pulsed) MOCVD of AlN against published data. Subsequently, it is exercised for pulsed MOCVD with various pulse widths, precursor gas flow rates, wafer temperature, and reactor pressure. It is found that in order to significantly reduce particle formation, the group-III and group-V precursors need to be separated by a carrier gas pulse, and the carrier gas pulse should be at least 5–6 times as long as the precursor gas pulses. The studies also reveal that with the same time-averaged precursor gas flow rates as steady injection (non-pulsed) conditions, pulsed MOCVD can result in higher film growth rates because the precursors are incorporated into the film, rather than being wasted as particles. The improvement in growth rate was noted for both horizontal and vertical reactors, and was found to be most pronounced for intermediate wafer temperature and intermediate reactor pressure.
Hydronephrosis and loin pain as a presentation of tubo-ovarian abscess developing after Mirena coil removal: Figure 1
Authors: Christodoulidou Michelle , Thomas Mathew , Sharma Sanjeev D
Published: August 2012

We present an unusual and complicated case of a 39-year-old woman who was admitted three times in hospital over a period of 4 weeks, with abdominal pain initially and then right loin pain, fever and feeling generally unwell. She was investigated on each admission with different diagnoses set each time, but only on her last admission due to persisting symptoms, an MRI scan revealed a tubo-ovarian abscess associated with pelvic inflammatory disease (PID). We believe that the PID had developed secondary to the intrauterine device and a few weeks after the removal of the Mirena coil she was diagnosed with a tubo-ovarian abscess. As the case unfolds, we will introduce the possible diagnoses and causes that were likely to have led to the development of the abscess.
Chemotherapy protocols used in veterinary practice
Authors: Polton Gerry
Published: July 2012

Chemotherapy is widely used by veterinary practices in the UK, and the most common indication is for treating canine lymphomas. In a Vetnosis study conducted in 2008, 98 per cent of respondents reported that they used chemotherapy in small animal practice. The aim of this article is to summarise the chemotherapy protocols that are regularly used, discuss their applications and give practical guidance in their use. The article will also consider the rights and responsibilities associated with the decision to use cytotoxic chemotherapy, and discuss the toxicities associated with generic treatment.
Organic dairy farming 1. Structure, economics and the veterinary approach to assisting production
Authors: Hayton Alastair
Published: July 2012

Veterinary surgeons have an increasingly important role to play in providing services to organic farmers, to ensure that they can sustain profitable production. This article reviews the structure and overall veterinary approach to the organic dairy sector. A second article, to be published in the September issue of

In Practice, will look at the management and control of diseases on dairy units under organic regulations.
Optimising the cost and delivery of HIV counselling and testing services in Kenya and Swaziland
Authors: Obure Carol Dayo , Vassall Anna , Michaels Christine , Terris-Prestholt Fern , Mayhew Susannah , Stackpool-Moore Lucy , Warren Charlotte ,   The Integra research team,, Watts Charlotte
Published: August 2012

Background

Approaches to HIV counselling and testing (HCT) within low-resource high HIV prevalence settings have shifted over the years from primarily client-initiated approaches to provider initiated. As part of an ongoing programme science research agenda, we examine the relative costs of provider-initiated testing and counselling (PITC) services compared with voluntary counselling and testing (VCT) services in the same health facilities in two low-resource settings: Kenya and Swaziland.

Methods

Annual financial and economic costs and output measures were collected retrospectively from 28 health facilities. Total annual costs and average costs per client counselled and tested (C&T), and HIV-positive clients identified, were estimated.

Results

VCT remains the predominant mode of HCT service delivery across both countries. However, unit cost per client C&T and per person testing HIV positive is lower for PITC than VCT across all facility types in Kenya, but the picture is mixed in Swaziland. Average cost per client C&T ranged from US$4.81 to US$6.11 in Kenya, US$6.92 to US$13.51 in Swaziland for PITC, and from US$5.05 to US$16.05 and US$8.68 to US$19.32 for VCT in Kenya and Swaziland, respectively.

Conclusions

In the context of significant policy interest in optimising scarce HIV resources, this study demonstrates that there may be potential for substantial gains in efficiency in the provision of HCT services in both Kenya and Swaziland. However, considerations of how to deliver services efficiently need to be informed by local contextual factors, such as prevalence, service demand and availability of human resources.
Reference ranges for laboratory parameters in ferrets
Authors: Hein J. , Spreyer F. , Sauter‐Louis C. , Hartmann K.
Published: August 2012

The purpose of this study was to establish reference ranges (robust methods) for 51 laboratory parameters in ferrets for use in private practice. Current literature concerning reference values in ferrets is often based on small patient numbers, methods of blood sampling not suitable for practice, and outdated laboratory methods. Blood was collected from theV saphena lateralisof 111 clinically healthy ferrets (age 11 weeks to 9 years; 61 male, 50 female). Age, sex (male or female) and fasting status were taken into consideration. Parameters evaluated included haematological parameters (packed cell volume, haemoglobin, erythrocytes, erythrocyte indices, white blood cells, differential blood counts, platelets) (Cell‐Dyn3500R; microscopical differential blood count), serum parameters (alanine aminotransferase, alkaline phosphatase, aspartate aminotransaminase, glutamate dehydrogenase,γ‐glutamyltranspeptidase, lactate dehydrogenase, creatine kinase,α‐amylase, lipase, cholinesterase, glucose, fructosamine, total protein, cholesterol, triglycerides, serum bile acids, bilirubin, urea, creatinine), serum electrolyte levels (calcium, phosphorus, magnesium, sodium, potassium, chloride, iron) (Hitachi 911), and serum hormone concentrations (thyroxine, cortisol, oestradiol, progesterone) (Elecsys 1010). Results differing from reference ranges reported in current literature were attributed in most cases to the use of other blood sampling methods and laboratory equipment.
Suspected metaldehyde slug bait poisoning in dogs: a retrospective analysis of cases reported to the Veterinary Poisons Information Service
Authors: Bates N. S. , Sutton N. M. , Campbell A.
Published: August 2012

A retrospective analysis of telephone enquiries to the Veterinary Poisons Information Service found 772 cases with follow‐up concerning suspected metaldehyde slug bait ingestion in dogs between 1985 and 2010. Half the enquiries occurred in the summer months. The amount and strength of the slug bait ingested was rarely known. In 56, cases the quantity consumed was estimated and was on average 229.6 grams of bait. Clinical signs developed in 77.3 per cent of dogs; common signs were convulsions, hypersalivation, twitching, hyperaesthesia, tremor, vomiting, hyperthermia and ataxia. Only 4.6 per cent of dogs developed hepatic changes, and only one developed renal impairment. The average time to onset of signs was 2.9 hours post‐ingestion, with 50.3 per cent of dogs developing effects within one hour. Increased muscle activity (twitching, convulsions) lasted on average 15.2 hours. Recovery time was reported in 61 cases and occurred on average at 39.3 hours. Common treatments were gut decontamination, anticonvulsants, anaesthetics and intravenous fluids. Of the dogs that were treated with sedatives, 45.8 per cent required more than one sedative or anaesthetic agent. Methocarbamol was rarely used, probably due to unavailability. The outcome was reported in 762 dogs; 21.7 per cent remained asymptomatic, 61.7 per cent recovered and 16 per cent of dogs died or were euthanased. Where known (only six cases), the fatal dose of bait ranged from 4.2 to 26.7 g/kg (average 11.8 g/kg).
Bags-of-Features for fish school cluster characterization in pelagic ecosystems: application to the discrimination of juvenile and adult anchovy (Engraulis ringens) clusters off Peru
Authors: Fablet Ronan , Gay Paul , Peraltilla Salvador , Peña Cecilia , Castillo Ramiro , Bertrand Arnaud
Published: July 2012

Whereas fisheries acoustics data processing mainly focused on the detection, characterization, and recognition of individual fish schools, here we addressed the characterization and discrimination of fish school clusters. The proposed scheme relied on the application of the Bags-of-Features (BoF) approach to acoustic echograms. This approach is widely exploited for pattern recognition issues and naturally applies here, considering fish schools as the relevant elementary objects. It relies on the extraction and categorization of fish schools in fisheries acoustic data. Echogram descriptors were computed per unit echogram length as the numbers of schools in different school categories. We applied this approach to the discrimination of juvenile and adult anchovy ( Engraulis ringens ) off Peru. Whereas the discrimination of individual schools is low (below 70%), the proposed BoF scheme achieved between 89% and 92% of correct classification of juvenile and adult echograms for different survey data sets and significantly outperformed classical school-based echogram characteristics (about 10% of improvement of the correct classification rate). We further illustrate the potential of the proposed scheme for the estimation of the spatial distribution of juvenile and adult anchovy populations.
Movement of adult temperate reef fishes off the west coast of North America
Authors: Freiwald Jan
Published: July 2012

Movement of reef fishes has important consequences for the demography, spatial structure, and connectivity of their populations and their conservation and management. I synthesized and analyzed the available data on the movement of adult temperate reef fishes along the west coast of North America to summarize our current knowledge and identify future research needs. For 80% of analyzed species, the 75th percentile movement distance was less than 1.5 km. Movement distances of examined species are characterized by positively skewed frequency distributions and discrete movement ranges rather than unbounded diffusive or directional movement. There is no relationship between species body size and movement distance, but shallower living species move much shorter distances than deeper dwelling reef fishes. Such limited movement suggests that ecological neighborhoods of adult individuals are small, and finite movement ranges will have important consequences for understanding and modeling population connectivity in ecological and management contexts. Future research should focus on effects of habitat heterogeneity and population parameters on movement to investigate variability in movement patterns and its consequences for species’ ecology and management.
SCATTERING THEORY FOR LATTICE OPERATORS IN DIMENSION d ≥ 3
Authors: BELLISSARD JEAN , SCHULZ-BALDES HERMANN
Published: July 2012

This paper analyzes the scattering theory for periodic tight-binding Hamiltonians perturbed by a finite range impurity. The classical energy gradient flow is used to construct a conjugate (or dilation) operator to the unperturbed Hamiltonian. For dimension d ≥ 3, the wave operator is given by an explicit formula in terms of this dilation operator, the free resolvent and the perturbation. From this formula, the scattering and time delay operators can be read off. Using the index theorem approach, a Levinson theorem is proved which also holds in the presence of embedded eigenvalues and threshold singularities.
COHERENT ANTI-STOKES RAMAN SCATTERING HOLOGRAPHY: THEORY AND EXPERIMENT
Authors: EDWARDS PERRY S. , MEHTA NIKHIL , SHI KEBIN , XU QIAN , PSALTIS DEMETRI , LIU ZHIWEN
Published: August 2012

We review coherent anti-Stokes Raman scattering (CARS) holography as a non-scanning, label-free, three-dimensional imaging technique. The theory of CARS and its integration with digital holography is explored. We then discuss the experimental implementations of CARS holography including in-line and off-axis modalities and the demonstrations of three-dimensional imaging, chemical selectivity and the application of CARS holography to biological imaging.
SPECTRAL PROPERTIES OF OPERATORS USING TRIDIAGONALIZATION
Authors: ISMAIL MOURAD E. H. , KOELINK ERIK
Published: August 2012

A general scheme for tridiagonalizing differential, difference or q-difference operators using orthogonal polynomials is described. From the tridiagonal form the spectral decomposition can be described in terms of the orthogonality measure of generally different orthogonal polynomials. Three examples are worked out: (1) related to Jacobi and Wilson polynomials for a second order differential operator, (2) related to little q-Jacobi polynomials and Askey–Wilson polynomials for a bounded second order q-difference operator, (3) related to little q-Jacobi polynomials for an unbounded second order q-difference operator. In case (1) a link with the Jacobi function transform is established, for which we give a q-analogue using example (2).
A NOTE ON CONSTABELIAN CODES
Authors: Grover Pooja , Bhandari Ashwani K.
Published: July 2012

In this note, the relationship between Abelian codes and corresponding Constabelian codes of smaller lengths has been studied.
Observation of Current Enhancement Due to Drain-Induced Drain Tunneling in Tunnel Field-Effect Transistors
Authors: Mallik Abhijit , Chattopadhyay Avik
Published: August 2012

It is well-established that a tunnel field-effect transistor (TFET) may or may not show a good drain current saturation in its output characteristics, depending upon its device structure. In this paper, we report for the first time a new phenomenon in double-gate silicon TFETs, which causes a sudden increase in its drain current at larger drain voltages, independent of whether they show a good output current saturation or not in the initial portion of their output characteristics. It is observed that larger drain voltages result in band-to-band tunneling of the electrons occurring from the valance band of the channel to the conduction band of the drain, which causes such sudden increase of drain current.
Surface Functionalization of Diamond Films by Photoreaction of Elemental Sulfur and Their Surface Properties
Authors: Nakamura Takako , Ohana Tsuguyori
Published: August 2012

A useful method for direct sulfurization of diamond film surfaces by photoreaction of elemental sulfur was developed. The introduction of thiol groups onto the diamond films was confirmed by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, and scanning electron microscopy (SEM) analyses. The sulfur-modified diamond films attached to gold nanoparticles by self-assembly. The degrees of thiol group introduction and gold attachment were found to depend on photoirradiation time by monitoring by XPS. The gold-modified diamond film was observed to act as a surface-enhanced Raman scattering substrate for measurement of picric acid.
Dielectric Properties and Crystal Structure of Mg4Nb2O9 Ceramics with Mg2+ Substituted by Zn2+ and Co2+
Authors: Chen Yuan-Bin
Published: August 2012

Dielectric properties of (Mg0.9Zn0.1)4-x
Co
x
Nb2O9 prepared by solid state reaction were investigated. The theoretical polarizability of (Mg0.9Zn0.1)4-x
Nb2O9–xCoNb2O9 increased with Co substitution, x. Single-phase perovskite can be obtained in the range from x=0.3 to 1. The maximum properties of the (Mg0.9Zn0.1)4-x
Co
x
Nb2O9 system were namely, an obtained εr value of 12.78, a Q×f value of 190000GH, and a τf value of -65 ppm/°C for (Mg0.9Zn0.1)4-x
Co
x
Nb2O9 in x=0.3 ceramics sintered at 1200 °C. The theoretical polarizability of (Mg0.9Zn0.1)4-x
Nb2O9–xCoNb2O9 increased with Co substitution, x. Mg4Nb2O9 with Mg2+ substituted by Zn2+ and Co2+ not only improved the microwave dielectric properties, but also decreased sintering temperature. From the calculation of the covalency of cation–oxygen bonds, it is found that the covalency of the Co–O bond is lower than that of the Mg–O bond and the difference in the covalency between these cation–oxygen bonds influences the temperature dependence of dielectric constant on the compounds. As for the dielectric constant (εr) and the quality factor (Q×f) of the ceramics, these values ranged from 11.55 to 14.48 and from 190,000 to 4,700 GHz, respectively, depending on the composition x. The maximum properties of the (Mg0.9Zn0.1)4-x
Co
x
Nb2O9 system, namely, a dielectric constant of 12.78, a Q×f value of 190,000 GHz and a τf value of -65 ppm/°C were obtained for (Mg0.9Zn0.1)4-x
Co
x
Nb2O9 (x=0.3) ceramics sintered at 1200 °C.
Luminal hypertonicity and acidity modulate colorectal afferents and induce persistent visceral hypersensitivity
Authors: La Jun-Ho , Feng Bin , Schwartz Erica S. , Brumovsky Pablo R. , Gebhart G. F.
Published: August 2012

Carbohydrate malabsorption such as in lactose intolerance or enteric infection causes symptoms that include abdominal pain. Because this digestive disorder increases intracolonic osmolarity and acidity by accumulation of undigested carbohydrates and fermented products, we tested whether these two factors (hypertonicity and acidity) would modulate colorectal afferents in association with colorectal nociception and hypersensitivity. In mouse colorectum-pelvic nerve preparations in vitro, afferent activities were monitored after application of acidic hypertonic saline (AHS; pH 6.0, 800 mosM). In other experiments, AHS was instilled intracolonically to mice and behavioral responses to colorectal distension (CRD) measured. Application of AHS in vitro excited 80% of serosal and 42% of mechanically-insensitive colorectal afferents (MIAs), sensitizing a proportion of MIAs to become mechanically sensitive and reversibly inhibiting stretch-sensitive afferents. Acute intracolonic AHS significantly increased expression of the neuronal activation marker pERK in colon sensory neurons and augmented noxious CRD-induced behavioral responses. After three consecutive daily intracolonic AHS treatments, mice were hypersensitive to CRD 4–15 days after the first treatment. In complementary single fiber recordings in vitro, the proportion of serosal class afferents increased at day 4; the proportion of MIAs decreased, and muscular class stretch-sensitive afferents were sensitized at days 11–15 in mice receiving AHS. These results indicate that luminal hypertonicity and acidity, two outcomes of carbohydrate malabsorption, can induce colorectal hypersensitivity to distension by altering the excitability and relative proportions of colorectal afferents, suggesting the potential involvement of these factors in the development of abdominal pain.
Decreased DNA fragmentation and apoptotic signaling in soleus muscle of hypertensive rats following 6 weeks of treadmill training
Authors: McMillan Elliott M. , Graham Drew A. , Rush James W. E. , Quadrilatero Joe
Published: August 2012

Cardiovascular diseases such as hypertension are associated with a generalized skeletal myopathy including a proapoptotic phenotype. Current evidence suggests that exercise may alter apoptosis-related signaling in skeletal muscle; however, the effect of exercise on skeletal muscle DNA fragmentation and apoptotic signaling is unclear in hypertensive animals. Male normotensive Wistar Kyoto (WKY; n = 24) and spontaneously hypertensive rats (SHR; n = 24) were assigned to a sedentary (SED) condition or exercise (EX) consisting of progressive treadmill running 5 days/wk for 6 wks. Consistent with our previous work we found that soleus muscle of hypertensive animals had significantly higher DNA fragmentation (a hallmark of apoptosis), elevated proapoptotic factors (Bax, caspase-3 activity), and lower antiapoptotic proteins (apoptosis repressor with caspase recruitment domain, Bcl-2, X-linked inhibitor of apoptosis protein) compared with normotensive rats. In addition, soleus muscle of hypertensive animals displayed myosin accumulation and fragmentation, had elevated cytosolic cytochrome c, second mitochondrial-derived activator of caspase (Smac), apoptosis inducing factor (AIF), and endonuclease G protein levels, higher nuclear AIF content, and greater muscle reactive oxygen species generation compared with normotensive animals. Interestingly, exercise training significantly lowered DNA fragmentation and myosin accumulation/fragmentation in soleus muscle of hypertensive rats. Furthermore, exercise training significantly reduced cytosolic levels of cytochrome c as well as cytosolic and nuclear AIF in soleus muscle of hypertensive animals. This beneficial response is likely due to exercise-mediated elevations in Bcl-2, heat shock protein 70, and manganese superoxide dismutase protein content, as well as reductions in Bax protein levels and the Bax-to-Bcl-2 ratio. These results suggest that regular exercise training provides protection against skeletal muscle apoptosis by altering a number of apoptosis regulatory proteins and by influencing mitochondrial-mediated apoptotic signaling mechanisms.
Influence of exercise training on ischemic brain injury in type 1 diabetic rats
Authors: Arrick Denise M. , Sun Hong , Mayhan William G.
Published: August 2012

While exercise training (ExT) appears to influence cerebrovascular function during type 1 diabetes (T1D), it is not clear whether this beneficial effect extends to protecting the brain from ischemia-induced brain injury. Thus our goal was to examine whether modest ExT could influence transient focal ischemia-induced brain injury along with nitric oxide synthase (NOS)-dependent dilation of cerebral (pial) arterioles during T1D. Sprague-Dawley rats were divided into four groups: nondiabetic sedentary, nondiabetic ExT, diabetic (streptozotocin; 50 mg/kg ip) sedentary, and diabetic ExT. In the first series of studies, we measured infarct volume in all groups of rats following right MCA occlusion for 2 h, followed by 24 h of reperfusion. In a second series of studies, a craniotomy was performed over the parietal cortex, and we measured responses of pial arterioles to an endothelial NOS (eNOS)-dependent, a neuronal NOS (nNOS)-dependent, and a NOS-independent agonist in all groups of rats. We found that sedentary diabetic rats had significantly larger total, cortical, and subcortical infarct volumes following ischemia-reperfusion than sedentary nondiabetic, nondiabetic ExT, and diabetic ExT rats. Infarct volumes were similar in sedentary nondiabetic, ExT nondiabetic, and ExT diabetic rats. In contrast, ExT did not alter infarct size in nondiabetic compared with sedentary nondiabetic rats. In addition, ExT diabetic rats had impaired eNOS- and nNOS-dependent, but not NOS-independent, vasodilation that was restored by ExT. Thus ExT of T1D rats lessened ischemic brain injury following middle cerebral artery occlusion and restored impaired eNOS- and nNOS-dependent vascular function. Since the incidence of ischemic stroke is increased during T1D, we suggest that our finding are significant in that modest ExT may be a viable preventative therapeutic approach to lessen ischemia-induced brain injury that may occur in T1D subjects.
Procedural Complications of Spinal Anaesthesia in the Obese Patient
Authors: Wenk Manuel , Weiss Christian , Möllmann Michael , Pöpping Daniel Matthias
Published: July 2012

Background. Complications of spinal anaesthesia (SpA) range between 1 and 17%. Habitus and operator experience may play a pivotal role, but only sparse data is available to substantiate this claim.Methods. 161 patients were prospectively enrolled. Data such as spread of block, duration of puncture, number of trials, any complication, operator experience, haemodynamic parameters, was recorded and anatomical patient habitus assessed.Results. Data from 154 patients were analyzed. Success rate of SpA in the group of young trainees was 72% versus 100% in the group of consultants. Trainees succeeded in patients with a normal habitus in 83.3% of cases versus 41.3% when patients had a difficult anatomy (P=0.02). SpA in obese patients (BMI ≥ 32) was associated with a significantly longer duration of puncture, an increased failure ratio when performed by trainees (almost 50%), and an increased number of bloody punctures.Discussion. Habitus plays a pivotal role for SpA efficiency. In patients with obscured landmarks, failure ratio in unexperienced operators is high. Hence, patient prescreening as well as adequate choice of operators may be beneficial for the success rate of SpA and contribute to less complications and better patient and trainee satisfaction.
Decomposition of Automorphisms of Certain Solvable Subalgebra of Symplectic Lie Algebra over Commutative Rings
Authors: Wang Xing Tao , Zhang Lei
Published: July 2012

LetCl+1(R)be the2(l+1)×2(l+1)matrix symplectic Lie algebra over a commutative ringRwith 2 invertible. Thentl+1CR  =  {m-1m-20-m-1T ∣ m̅1is anl+1upper triangular matrix,m̅2T=m̅2,  over  R}is the solvable subalgebra ofCl+1(R). In this paper, we give an explicit description of the automorphism group oftl+1(C)(R).
An Impulse Model for Computer Viruses
Authors: Zhang Chunming , Zhao Yun , Wu Yingjiang
Published: July 2012

Computer virus spread model concerning impulsive control strategy is proposed and analyzed. We prove that there exists a globally attractive infection‐free periodic solution when the vaccination rate is larger than θ0. Moreover, we show that the system is uniformly persistent if the vaccination rate is less than θ1. Some numerical simulations are finally given to illustrate the main results.
Effect of Preoperative Atrial Fibrillation on Postoperative Outcome following Cardiac Surgery
Authors: Al-Sarraf Nael , Thalib Lukman , Hughes Anne , Tolan Michael , Young Vincent , McGovern Eillish
Published: July 2012

Atrial fibrillation remains the commonest arrhythmia encountered in cardiac surgery. Data on the effect of preoperative atrial fibrillation on postoperative outcome remain limited. We sought to assess the effects preoperative atrial fibrillation on patients' outcome following cardiac surgery. This is a retrospective review of prospectively collected departmental data of all patients who underwent cardiac surgery over 8-year period. Our cohort consisted of 3777 consecutive patients divided into atrial fibrillation (n=413, 11%) and sinus rhythm (n=3364, 89%). Postoperative complications and in-hospital mortality were analysed. Univariate analysis showed significantly increased mortality and major complications in atrial fibrillation compared to sinus rhythm patients. Using multiple logistic regression analysis and after accounting for Euro SCORE as a confounding variable, we found that preoperative atrial fibrillation significantly increases the risk of mortality (OR 1.7), low cardiac output state (OR 1.3), prolonged ventilation (OR 1.4), infective complication (OR 1.5), gastrointestinal complications (OR 2.0), and intensive care unit readmission (OR 1.6). Preoperative atrial fibrillation in cardiac surgery patients increases their risk of mortality and major complications following cardiac surgery. Surgical strategies such as Cox-Maze procedure may be beneficial in these patients.
Acid-Fast Bacilli Other than Mycobacteria in Tuberculosis Patients Receiving Directly Observed Therapy Short Course in Cross River State, Nigeria
Authors: Pokam Benjamin Thumamo , Asuquo Anne E.
Published: July 2012

The information on the contribution of non tuberculous mycobacteria (NTM) to mycobacterial infections in Africa is scarce due to limited laboratory culture for its isolation and identification. One hundred and thirty-seven sputum smear positive patients were recruited into a study on the molecular epidemiology ofMycobacterium tuberculosisin Cross River State. Following sputum culture, 97 pure isolates were obtained and identified using Capilia TB-Neo and further confirmed by the GenoType Mycobacterium CM kit. Of the 97 isolates, 81 (83.5%) isolates were Capilia TB-Neo positive while 16 (16.5%) were Capilia TB-Neo negative. Further confirmation with the GenoType Mycobacterium CM kit revealed that 4 (25%) of the 16 isolates belonged to NTM and includedM. fortuitum I, M. fortuitum II/M magaritense, M. abscessus,andM. aviumssp. The remaining 12 (75%) Capilia TB-Neo negative isolates were not members of the genusMycobacteriumdespite their AFB appearance. Six (33.3%) of the Capilia TB-Neo negative were from HIV positive tuberculosis patients. All subjects in this study were placed on DOTS shortly after the AFB results were obtained. The implication of isolation of 16.5% nontuberculous isolates further emphasizes the need for culture of sputum specimen especially in HIV positive patients prior to administration of antituberculosis therapy.
Combining Neural Methods and Knowledge-Based Methods in Accident Management
Authors: Sirola Miki , Talonen Jaakko
Published: July 2012

Accident management became a popular research issue in the early 1990s. Computerized decision support was studied from many points of view. Early fault detection and information visualization are important key issues in accident management also today. In this paper we make a brief review on this research history mostly from the last two decades including the severe accident management. The author’s studies are reflected to the state of the art. The self-organizing map method is combined with other more or less traditional methods. Neural methods used together with knowledge-based methods constitute a methodological base for the presented decision support prototypes. Two application examples with modern decision support visualizations are introduced more in detail. A case example of detecting a pressure drift on the boiling water reactor by multivariate methods including innovative visualizations is studied in detail. Promising results in early fault detection are achieved. The operators are provided by added information value to be able to detect anomalies in an early stage already. We provide the plant staff with a methodological tool set, which can be combined in various ways depending on the special needs in each case.
In Vitro Photothermal Destruction of Cancer Cells Using Gold Nanorods and Pulsed‐Train Near‐Infrared Laser
Authors: Lin Jui-Teng , Chiang Yueh-Sheng , Lin Guang-Hong , Lee Hsinyu , Liu Hsia-Wei
Published: July 2012

We present a novel pulsed‐train near‐IR diode laser system with real‐time temperature monitoring of the laser‐heated cancer cell mixed in gold nanorod solution. Near‐IR diode laser at 808 nm matching the gold nanorod absorption peak (with an aspect ratio about 4.0) was used in this study. Both surface and volume temperatures were measured and kept above 43°C, the temperature for cancer cells destruction. The irradiation time needed in our pulsed‐train system with higher laser fluence for killing the cancel cells is about 1–3 minutes, much shorter than conventional methods (5–10 minutes). Cell viabilities in gold nanorod mixed and controlled solutions are studied by green fluorescence.
Numerical Algorithms for Computing Eigenvalues of Discontinuous Dirac System Using Sinc‐Gaussian Method
Authors: Bhrawy A. H. , Tharwat M. M. , Al-Fhaid A.
Published: July 2012

The eigenvalues of a discontinuous regular Dirac systems with transmission conditions at the point of discontinuity are computed using the sinc‐Gaussian method. The error analysis of this method for solving discontinuous regular Dirac system is discussed. It shows that the error decays exponentially in terms of the number of involved samples. Therefore, the accuracy of the new method is higher than the classical sinc‐method. Numerical results indicating the high accuracy and effectiveness of these algorithms are presented. Comparisons with the classical sinc‐method are given.
Might Cigarettes Be a “Smoking Gun” to Reduce Taxane Myelotoxicity?
Authors: Lewis Lionel D. , Ratain Mark J.
Published: August 2012

de Graan and colleagues report a retrospective study of the effects of cigarette smoking on taxane pharmacokinetics and myelosuppression. There was no difference in taxane pharmacokinetic clearance between smokers and nonsmokers. Further prospective studies of the effects of cigarette smoking on myelosuppression would be of interest. Clin Cancer Res; 18(16); 4219–21. ©2012 AACR.
Normal Reference Ranges from 11 to 41 Weeks’ Gestation of Fetal Left Modified Myocardial Performance Index by Conventional Doppler with the Use of Stringent Criteria for Delimitation of the Time Periods
Authors: Cruz-Martínez R. , Figueras F. , Bennasar M. , García-Posadas R. , Crispi F. , Hernández-Andrade E. , Gratacós E.
Published: July 2012

Objective: To establish normal reference intervals of the fetal left modified myocardial performance index (MPI) with the use of stringent criteria for delimitation of the time periods. Study Design: A cohort of consecutive singleton fetuses was created including at least 20 fetuses for each completed week of gestation between 11 and 41 weeks. The isovolumetric contraction time (ICT), isovolumetric relaxation time (IRT), and ejection time (ET) were calculated using the clicks of the mitral and aortic valves as landmarks, and the MPI was calculated as follows: (ICT + IRT)/ET. Normal reference ranges for the MPI and its individual components were constructed by means of regression analysis of the mean and standard deviation against gestational age (GA). Results: A total of 730 fetuses were included. After a natural logarithmic transformation, a third degree cubic polynomial model (loge mean MPI = 0.0477 × GA – 0.002565 × GA2 + 0.000043 × GA3 –1.22, with GA measured in weeks) was selected to fit our data. There was a progressive increase in the mean MPI from 11 weeks (mean, 0.39; 95th centile, 0.51) to 41 weeks (mean, 0.55; 95th centile, 0.78) of gestation. While the mean ICT and IRT values increased with GA from 25 to 32 ms and from 39 to 51 ms, respectively, the ET showed an initial increase until 30 weeks and a progressive decrease thereafter. Conclusion: Normative references of left modified MPI from 11 to 41 weeks of gestation are provided, which could be useful in the assessment of cardiac function in fetuses.
Veil Nerve-Sparing Technique and Postoperative Urinary Continence in Open Antegrade Radical Prostatectomy
Authors: Shigemura Katsumi , Yamanaka Nozomu , Yamashita Masuo
Published: August 2012

Purpose: To introduce and evaluate our open antegrade radical prostatectomy (ARP) technique, a nerve-sparing technique which offers patients better postsurgical urinary continence by our technique of ‘Veil of Aphrodite’. Methods: Ninety consecutive bilateral nerve-sparing ARPs performed using the Veil technique (intrafascial dissection) were compared to control ARP cases using non- or unilateral nerve sparing. Correlation of urinary continence with immunohistochemical (IHC) stains of nerves (S-100) around the prostate capsule was investigated in 20 consecutive patients whose ARPs were performed by a single surgeon. Results: Fifty-one cases (56.7%) had no urinary incontinence and 72 cases (80.0%) had no or only minor urinary leakage (less than 5% in total a day), and these were significantly higher than in the control group (p = 0.000 and 0.003, respectively) without compromising the surgical margins. S-100 IHC stains significantly correlated nerve sparing (bilateral sparing vs. non-sparing, p = 0.0398), urinary continence (no urinary continence vs. more than 5% in total urine volume a day, p = 0.0489), and early removal of catheter (within a week vs. over a week, p = 0.0041). Conclusions: Open nerve-sparing ARP using the Veil technique may offer better urinary continence postoperatively and this may be supported by S-100 IHC results. This method may be adaptable in any surgical institution.
Efficacy and Safety of a Novel ĸ-Agonist for Managing Intractable Pruritus in Dialysis Patients
Authors: Kumagai Hiroo , Ebata Toshiya , Takamori Kenji , Miyasato Katsumasa , Muramatsu Taro , Nakamoto Hidetomo , Kurihara Masanao , Yanagita Tomoji , Suzuki Hiromichi
Published: August 2012

Background: Our previous placebo-controlled, prospective, double-blind study demonstrated that a new opioid ĸ-receptor agonist, nalfurafine hydrochloride, effectively reduced treatment-resistant pruritus in 337 hemodialysis patients. Thus, we designed this study to evaluate prospectively the efficacy, safety, addiction liability, and pharmacokinetics of nalfurafine given orally for 1 year. Methods: This open-label study examined the effects and adverse drug reactions (ADRs) of 52-week oral administration of nalfurafine hydrochloride (5 µg/day) in 211 hemodialysis patients with a treatment-resistant itch. Results: Of 211 patients, 145 completed the study as scheduled. The mean pruritus value assessed by the visual analogue scale was 75.2 mm during the pre-observation period, which decreased significantly to 50.9 and 30.9 mm in week 2 and 52, respectively, indicating a long-lasting efficacy. ADRs occurred in 103 patients (48.8%). Frequent ADRs were insomnia (sleep disturbance, 19.4%), constipation (7.1%) and increased blood prolactin (3.3%), similar to previous reports. Regarding addiction liability, it appeared unlikely that nalfurafine hydrochloride was abused. After the start of treatment, plasma drug levels reached a steady state in week 2 with no apparent tendency of systemic accumulation. Conclusions: Nalfurafine hydrochloride, orally administered at 5 µg/day for 52 weeks to hemodialysis patients, produced a long-term suppression of pruritus without significant safety problems.
The Precipitation Characteristics of ISCCP Tropical Weather States
Authors: Lee Dongmin , Oreopoulos Lazaros , Huffman George J. , Rossow William B. , Kang In-Sik
Published: August 2012

The authors examine the daytime precipitation characteristics of the International Satellite Cloud Climatology Project (ISCCP) weather states in the extended tropics (35°S–35°N) for a 10-yr period. The main precipitation dataset used is the Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis operational product 3B42 dataset, but Global Precipitation Climatology Project daily data are also used for comparison. It is found that the most convectively active ISCCP weather state (WS1), despite an occurrence frequency below 10%, is the most dominant state with regard to surface precipitation, producing both the largest mean precipitation rates when present and the largest percent contribution to the total precipitation of the tropics; yet, even this weather state appears to not precipitate about half the time, although this may be to some extent an artifact of detection and spatiotemporal matching limitations of the precipitation dataset. WS1 exhibits a modest annual cycle of the domain-average precipitation rate, but notable seasonal shifts in its geographic distribution. The precipitation rates of the other weather states appear to be stronger when occurring before or after WS1. The precipitation rates of the various weather states are different between ocean and land, with WS1 producing higher daytime rates on average over ocean than land, likely because of the larger size and more persistent nature of oceanic WS1s. The results of this study, in addition to advancing the understanding of tropical hydrology, can serve as higher-order diagnostics for evaluating the realism of tropical precipitation distributions in large-scale models.
Implications of Parameter Uncertainty on Soil Moisture Drought Analysis in Germany
Authors: Samaniego Luis , Kumar Rohini , Zink Matthias
Published: August 2012

Simulated soil moisture is increasingly used to characterize agricultural droughts but its parametric uncertainty, which essentially affects all hydrological fluxes and state variables, is rarely considered for identifying major drought events. In this study, a high-resolution, 200-member ensemble of land surface hydrology simulations obtained with the mesoscale Hydrologic Model is used to investigate the effects of the parametric uncertainty on drought statistics such as duration, extension, and severity. Simulated daily soil moisture fields over Germany at the spatial resolution of 4 × 4 km2 from 1950 to 2010 are used to derive a hydrologically consistent soil moisture index (SMI) representing the monthly soil water quantile at every grid cell. This index allows a quantification of major drought events in Germany. Results of this study indicated that the large parametric uncertainty inherent to the model did not allow discriminating major drought events without a significant classification error. The parametric uncertainty of simulated soil moisture exhibited a strong spatiotemporal variability, which significantly affects all derived drought statistics. Drought statistics of events occurring in summer with at most 6 months duration were found to be more uncertain than those occurring in winter. Based on the ensemble drought statistics, the event from 1971 to 1974 appeared to have a 67% probability of being the longest and most severe drought event since 1950. Results of this study emphasize the importance of accounting for the parametric uncertainty for identifying benchmark drought events as well as the fact that using a single model simulation would very likely lead to inconclusive results.
Seasonal and Interannual Modulation of the Eddy Kinetic Energy in the Caribbean Sea
Authors: Jouanno Julien , Sheinbaum Julio , Barnier Bernard , Molines Jean Marc , Candela Julio
Published: August 2012

Variability of the mesoscale eddy field in the Caribbean Sea is analyzed over the period 1993–2009 using geostrophic anomalies derived from altimeter data and a high-resolution regional model. The Colombia Basin presents the largest values of eddy kinetic energy (EKE) and its semiannual cycle, with a main peak in August–October and a secondary peak in February–March, is the dominant feature in the whole Caribbean EKE cycle. The analysis of energy conversion terms between low-frequency currents and eddies explains these peaks by enhanced baroclinic and barotropic instabilities, in response to seasonally varying currents in the region of the Guajira Peninsula. The semiannual acceleration of the atmospheric Caribbean low-level jet intensifies the southern Caribbean Current (sCC) twice a year in this region, together with its vertical and horizontal velocity shears. The asymmetry of the EKE seasonal cycle in the Colombia Basin is explained by a summer peak in the annual cycle of the whole sCC. Numerical results suggest that the arrival of more energetic North Brazil Current rings during part of the year have almost no impact on the seasonal cycle of EKE in the Colombia Basin. Instead, they are shown to contribute, together with the annual cycle of the Caribbean inflow through the southern passages of the Lesser Antilles, to an annual peak of EKE in the Venezuela Basin between May and August. At the interannual scale the mechanism is similar: interannual variability of the alongshore wind stress controls the speed of the southern Caribbean Current and the energy of the eddies in the Colombia Basin through instability.
An Analysis of Cold Season Supercell Storms Using the Synthetic Dual-Doppler Technique
Authors: Murphy Todd A. , Knupp Kevin R.
Published: August 2012

Cold season tornadic outbreaks occur with regularity in the southeastern United States; however, detailed analyses of parent supercell storms in the cold season environment (often low CAPE, high shear) are scarce. This is often because storms do not always move close enough to radars for a comprehensive single-Doppler analysis and significant topography or trees in the Southeast make it difficult for mobile radars to operate, thus limiting dual-Doppler coverage. However, during the Super Tuesday tornado outbreak of 5–6 February 2008, two tornadic supercell storms passed within 30–40 km of the Weather Surveillance Radar-1988 Doppler (WSR-88D) sites in Memphis and Nashville, Tennessee (KNQA and KOHX, respectively). The relative steadiness of these storms during passage, along with the large motion vector (from the southwest at 20–25 m s−1), allowed the application of a synthetic dual-Doppler (SDD) analysis. As such, a detailed analysis of these storms was completed, including examinations of low-level circulations, updraft strength and location, as well as retrievals and evaluations of perturbation pressure and the vertical pressure gradient. This study presents one of the first comprehensive analyses of cold season supercells using only one Doppler radar. Additionally, the relative success and failures of using the SDD technique on supercell storms are discussed. Major findings for the primary case include the updraft maximizing at a very low height (3.0 km AGL), and weak pressure forcing within the rear flank resulting in a nonexistent rear-flank downdraft (RFD).
Prospects for the UK Economy
Authors: Kirby Simon , Lisenkova Katerina
Published: August 2012

The production of this forecast is supported by the Institute's Corporate Members: Bank of England, HM Treasury, Mizuho Research Institute Ltd, the Office for National Statistics, Santander (UK) plc and by the members of the NiGEM users group.