bluuebunny/crossref_metadata_2025 huggingface dataset:
Social Determinants of Health in Minority Populations: A Call for Multidisciplinary Approaches to Eliminate Diabetes-Related Health Disparities
Authors: Jack Leonard , Jack Nkenge H. , Hayes Sandra C.
Published: February 2012

In Brief

This article explores current discourse regarding the limitations of linear approaches to addressing diabetes prevention and control typically reported in efficacy investigations. The authors discuss the need for health professionals to understand the link between social determinants of health and health outcomes. They define social determinants of health, provide examples, and discuss how these social determinants affect minority health. This information can lead to the adoption of nontraditional strategies that involve the use of nontraditional partners and the identification of opportunities for improving or preventing negative health outcomes in communities affected by inequitable conditions.
Effect of Caries Infiltration Technique and Fluoride Therapy on Microhardness of Enamel Carious Lesions
Authors: Torres CRG , Rosa PCF , Ferreira NS , Borges A B
Published: February 2012

Enamel white spot subsurface lesions compromise esthetics and precede cavitation; therefore, they must be halted. The aim of this study was to evaluate the effect of a caries infiltration technique and fluoride therapy on the microhardness of enamel carious lesions. Subsurface carious lesions were produced in 60 bovine specimens with polished enamel surfaces. The specimens were divided into four groups (n=15), according to the treatment used: CON, control—immersion in artificial saliva; DF, daily 0.05% fluoride solution; WF, weekly 2% fluoride gel; and IC, resin infiltration (Icon). The specimens were kept in artificial saliva and evaluated for microhardness at five points: baseline, after caries production, after four and eight weeks of treatment, and a final evaluation after being submitted to a new acid challenge. The repeated-measures analysis of variance showed significant differences according to the type of treatment (TREAT; p=0.001) and time of evaluation (EV; p=0.001). The results of the Tukey test were TREAT: CON = 45.18 (±29.17)a, DF = 107.75 (±67.38)b, WF = 83.25 (±51.17)c, and IC = 160.83 (±91.11)d. Analysis of correlation between the TREAT and EV factors showed no significant differences for DF (138.63 ± 38.94) and IC (160.99 ± 46.13) after the new acid challenge. The microhardness results in decreasing order after eight weeks were IC > DF > WF > CON. It was concluded that the microhardness of carious lesions increased with the infiltration of resin, while the final microhardness after a new acid challenge was similar for DF and IC.
Meromorphic functions of infinite order in the angular domain
Authors: Chen Jun-Fan
Published: February 2012

We investigate the value distribution of meromorphic functions in the angular domain. In particular, we show a close relationship between radially distributed values and Borel directions of transcendental meromorphic functions of infinite order in some angular domains.
Extraordinary magnetoresistance: sensing the future
Authors: Hewett Thomas , Kusmartsev Feodor
Published: February 2012

Simulations utilising the finite element method (FEM) have been produced in order to investigate aspects of circular extraordinary magnetoresistance (EMR) devices. The effect of three specific features on the resultant magnetoresistance were investigated: the ratio of the metallic to semiconducting conductivities (σ M/σ S); the semiconductor mobility; and the introduction of an intermediate region at the semiconductormetal interface in order to simulate a contact resistance. In order to obtain a large EMR effect the conductivity ratio (σ M/σ S) is required to be larger than two orders of magnitude; below this critical value the resultant magnetoresistance effect is dramatically reduced. Large mobility semiconductors exhibit larger EMR values for a given field (below saturation) and reduce the magnetic field required to produce saturation of the magnetoresistance. This is due to a larger Hall angle produced at a given magnetic field and is consistent with the mechanism of the EMR effect. Since practical magnetic field sensors are required to operate at low magnetic fields, high mobility semiconductors are required in the production of more sensitive EMR sensors. The formation of a Schottky barrier at the semiconductor-metal interface has been modelled with the introduction of a contact resistance at the semiconductor-metal interface. Increasing values of contact resistance are found to reduce the EMR effect with it disappearing altogether for large values. This has been shown explicitly by looking at the current flow in the system and is consistent with the mechanism of the EMR effect. The interface resistance was used to fit the simulated model to existing experimental data. The best fit occurred with an interface with resistivity of 1.55×10−4 m (overestimate). The EMR effect holds great potential with regard to its future application to magnetic field sensors. The design of any such devices should incorporate high mobility materials (such as graphene) along with the specific features presented in this paper in order to produce effective magnetic field sensors.
Multi-Vehicle Planning using RRT-Connect*
Authors: Kala Rahul , Warwick Kevin
Published: February 2012

The problem of planning multiple vehicles deals with the design of an effective algorithm that can cause multiple autonomous vehicles on the road to communicate and generate a collaborative optimal travel plan. Our modelling of the problem considers vehicles to vary greatly in terms of both size and speed, which makes it sub-optimal to have a faster vehicle follow a slower vehicle or for vehicles to drive with predefined speed lanes. It is essential to have a fast planning algorithm whilst still being probabilistically complete. The Rapidly Exploring Random Trees (RRT) algorithm developed and reported on here uses a problem specific coordination axis, a local optimization algorithm, priority based coordination, and a module for deciding travel speeds. Vehicles are assumed to remain in their current relative position laterally on the road unless otherwise instructed. Experimental results presented here show regular driving behaviours, namely vehicle following, overtaking, and complex obstacle avoidance. The ability to showcase complex behaviours in the absence of speed lanes is characteristic of the solution developed.
Optimizing Coverage Performance of Multiple Random Path-planning Robots
Authors: Habib Md Ahsan , Alam M.S. , Siddique N.H.
Published: February 2012

This paper presents a new approach to the multi-agent coverage path-planning problem. An efficient multi-robot coverage algorithm yields a coverage path for each robot, such that the union of all paths generates an almost full coverage of the terrain and the total coverage time is minimized. The proposed algorithm enables multiple robots with limited sensor capabilities to perform efficient coverage on a shared territory. Each robot is assigned to an exclusive route which enables it to carry out its tasks simultaneously, e.g., cleaning assigned floor area with minimal path overlapping. It is very difficult to cover all free space without visiting some locations more than once, but the occurrence of such events can be minimized with efficient algorithms. The proposed multi-robot coverage strategy directs a number of simple robots to cover an unknown area in a systematic manner. This is based on footprint data left by the randomized path-planning robots previously operated on that area. The developed path-planning algorithm has been applied to a simulated environment and robots to verify its effectiveness and performance in such an application.
William Cranston: sedis apostolicae in regno Scotie protector
Authors: Protheroe Michael J.
Published: February 2012

This paper provides a critical examination of what has been written about William Cranston, an important (arguably a key) figure in Scottish and Parisian academic life in the mid-sixteenth century, including the significance of his Dialecticae Compendium. It addresses various questions arising from a multi-faceted career (illustrative of different aspects of this critical period for the Scottish Church) which is here eked out in more detail, and proposes a number of possibilities suggested by a closer reading of the available evidence. These relate to Cranston's education, subsequent connections, later influence, and the circumstances in which he died. It investigates the likely significance of his papal provision to the principalship of Aberdeen's university college (1547) and suggests possible reasons why this did not secure him the post. Whilst questioning whether he was dean of Merse, whether he and Calvin were acquainted, and whether his papal provision to the priory of Pluscarden was secured as early as 1561, the paper proposes the conceivable possibility of a key role for Cranston at the 1549 provincial council, in the nurturing of (subsequent Jesuit) vocations at St Andrews, and in relation to da Gouda's mission (1562), as examples of his considerable pro-Catholic influence. In conclusion the author reflects on the character that emerges from a previously shadowy life story.
Pre-Harvest Sugarcane Burning: Determination of Emission Factors through Laboratory Measurements
Authors: França Daniela de Azeredo , Longo Karla Maria , Neto Turibio Gomes Soares , Santos José Carlos , Freitas Saulo R. , Rudorff Bernardo F. T. , Cortez Ely Vieira , Anselmo Edson , Carvalho João Andrade
Published: February 2012

Sugarcane is an important crop for the Brazilian economy and roughly 50% of its production is used to produce ethanol. However, the common practice of pre-harvest burning of sugarcane straw emits particulate material, greenhouse gases, and tropospheric ozone precursors to the atmosphere. Even with policies to eliminate the practice of pre-harvest sugarcane burning in the near future, there is still significant environmental damage. Thus, the generation of reliable inventories of emissions due to this activity is crucial in order to assess their environmental impact. Nevertheless, the official Brazilian emissions inventory does not presently include the contribution from pre-harvest sugarcane burning. In this context, this work aims to determine sugarcane straw burning emission factors for some trace gases and particulate material smaller than 2.5 μm in the laboratory. Excess mixing ratios for CO2, CO, NOX, UHC (unburned hydrocarbons), and PM2.5 were measured, allowing the estimation of their respective emission factors. Average estimated values for emission factors (g kg−1 of burned dry biomass) were 1,303 ± 218 for CO2, 65 ± 14 for CO, 1.5 ± 0.4 for NOX, 16 ± 6 for UHC, and 2.6 ± 1.6 for PM2.5. These emission factors can be used to generate more realistic emission inventories and therefore improve the results of air quality models.
Oxysterols and Their Cellular Effectors
Authors: Olkkonen Vesa M. , Béaslas Olivier , Nissilä Eija
Published: February 2012

Oxysterols are oxidized 27-carbon cholesterol derivatives or by-products of cholesterol biosynthesis, with a spectrum of biologic activities. Several oxysterols have cytotoxic and pro-apoptotic activities, the ability to interfere with the lateral domain organization, and packing of membrane lipids. These properties may account for their suggested roles in the pathology of diseases such as atherosclerosis, age-onset macular degeneration and Alzheimer’s disease. Oxysterols also have the capacity to induce inflammatory responses and play roles in cell differentiation processes. The functions of oxysterols as intermediates in the synthesis of bile acids and steroid hormones, and as readily transportable forms of sterol, are well established. Furthermore, their actions as endogenous regulators of gene expression in lipid metabolism via liver X receptors and the Insig (insulin-induced gene) proteins have been investigated in detail. The cytoplasmic oxysterol-binding protein (OSBP) homologues form a group of oxysterol/cholesterol sensors that has recently attracted a lot of attention. However, their mode of action is, as yet, poorly understood. Retinoic acid receptor-related orphan receptors (ROR) α and γ, and Epstein-Barr virus induced gene 2 (EBI2) have been identified as novel oxysterol receptors, revealing new physiologic oxysterol effector mechanisms in development, metabolism, and immunity, and evoking enhanced interest in these compounds in the field of biomedicine.
Unconscious Cueing via the Superior Colliculi: Evidence from Searching for Onset and Color Targets
Authors: Fuchs Isabella , Ansorge Ulrich
Published: February 2012

According to the bottom-up theory of attention, unconscious abrupt onsets are highly salient and capture attention via the Superior Colliculi (SC). Crucially, abrupt onsets increase the perceived contrast. In line with the SC hypothesis, unconscious abrupt-onset cues capture attention regardless of the cue color when participants search for abrupt-onset targets (Experiment 1). Also, stronger cueing effects occur for higher than lower contrast cues (Experiment 2) and for temporally, rather than nasally, presented stimuli (Experiment 3). However, in line with the known color-insensitivity of the SC, the SC pathway is shunted and unconscious abrupt-onset cues no longer capture attention when the participants have to search for color-defined targets (Experiment 4) or color-singleton targets (Experiment 5). When using color change cues instead of abrupt-onset cues, the cueing effect also vanishes (Experiment 6). Together the results support the assumption that unconscious cues can capture attention in different ways, depending on the exact task of the participants, but that one way is attentional capture via the SC. The present findings also offer a reconciliation of conflicting results in the domain of unconscious attention.
Responses of Cryptofaunal Species Richness and Trophic Potential to Coral Reef Habitat Degradation
Authors: Enochs Ian C. , Manzello Derek P.
Published: February 2012

Coral reefs are declining worldwide as a result of many anthropogenic disturbances. This trend is alarming because coral reefs are hotspots of marine biodiversity and considered the ‘rainforests of the sea. As in the rainforest, much of the diversity on a coral reef is cryptic, remaining hidden among the cracks and crevices of structural taxa. Although the cryptofauna make up the majority of a reef’s metazoan biodiversity, we know little about their basic ecology or how these communities respond to reef degradation. Emerging research shows that the species richness of the motile cryptofauna is higher among dead (framework) vs. live coral substrates and, surprisingly, increases within successively more eroded reef framework structures, ultimately reaching a maximum in dead coral rubble. Consequently, the paradigm that abundant live coral is the apex of reef diversity needs to be clarified. This provides guarded optimism amidst alarming reports of declines in live coral cover and the impending doom of coral reefs, as motile cryptic biodiversity should persist independent of live coral cover. Granted, the maintenance of this high species richness is contingent on the presence of reef rubble, which will eventually be lost due to physical, chemical, and biological erosion if not replenished by live coral calcification and mortality. The trophic potential of a reef, as inferred from the abundance of cryptic organisms, is highest on live coral. Among dead framework substrates, however, the density of cryptofauna reaches a peak at intermediate levels of degradation. In summary, the response of the motile cryptofauna, and thus a large fraction of the reef’s biodiversity, to reef degradation is more complex and nuanced than currently thought; such that species richness may be less sensitive than overall trophic function.
Classical and Quantum Models in Non-Equilibrium Statistical Mechanics: Moment Methods and Long-Time Approximations
Authors: Alvarez-Estrada Ramon F.
Published: February 2012

We consider non-equilibrium open statistical systems, subject to potentials and to external “heat baths” (hb) at thermal equilibrium at temperature T (either with ab initio dissipation or without it). Boltzmann’s classical equilibrium distributions generate, as Gaussian weight functions in momenta, orthogonal polynomials in momenta (the position-independent Hermite polynomialsHn’s). The moments of non-equilibrium classical distributions, implied by the Hn’s, fulfill a hierarchy: for long times, the lowest moment dominates the evolution towards thermal equilibrium, either with dissipation or without it (but under certain approximation). We revisit that hierarchy, whose solution depends on operator continued fractions. We review our generalization of that moment method to classical closed many-particle interacting systems with neither a hb nor ab initio dissipation: with initial states describing thermal equilibrium at T at large distances but non-equilibrium at finite distances, the moment method yields, approximately, irreversible thermalization of the whole system at T, for long times. Generalizations to non-equilibrium quantum interacting systems meet additional difficulties. Three of them are: (i) equilibrium distributions (represented through Wigner functions) are neither Gaussian in momenta nor known in closed form; (ii) they may depend on dissipation; and (iii) the orthogonal polynomials in momenta generated by them depend also on positions. We generalize the moment method, dealing with (i), (ii) and (iii), to some non-equilibrium one-particle quantum interacting systems. Open problems are discussed briefly.
Pattern-Based Development and Management of Cloud Applications
Authors: Fehling Christoph , Leymann Frank , Rütschlin Jochen , Schumm David
Published: February 2012

Cloud-based applications require a high degree of automation regarding their IT resource management, for example, to handle scalability or resource failures. This automation is enabled by cloud providers offering management interfaces accessed by applications without human interaction. The properties of clouds, especially pay-per-use billing and low availability of individual resources, demand such a timely system management. We call the automated steps to perform one of these management tasks a “management flow”. Because the emerging behavior of the overall system is comprised of many such management flows and is often hard to predict, we propose defining abstract management flows, describing common steps handling the management tasks. These abstract management flows may then be refined for each individual use case. We cover abstract management flows describing how to make an application elastic, resilient regarding IT resource failure, and how to move application components between different runtime environments. The requirements of these management flows for handled applications are expressed using architectural patterns that have to be implemented by the applications. These dependencies result in abstract management flows being interrelated with architectural patterns in a uniform pattern catalog. We propose a method by use of a catalog to guide application managers during the refinement of abstract management flows at the design stage of an application. Following this method, runtime-specific management functionality and management interfaces are used to obtain automated management flows for a developed application.
Application of Porous Nickel-Coated TiO2 for the Photocatalytic Degradation of Aqueous Quinoline in an Internal Airlift Loop Reactor
Authors: Zhu Suiyi , Yang Xia , Yang Wu , Zhang Leilei , Wang Jian , Huo Mingxin
Published: February 2012

P25 film, prepared by a facile dip-coating method without any binder, was further developed in a recirculating reactor for quinoline removal from synthetic wastewater. Macroporous foam Ni, which has an open three-dimensional network structure, was utilized as a substrate to make good use of UV rays. Field emission scanning electron microscopy and X-ray diffraction analysis showed that the coated/calcinated P25 films consisted of two crystal phases, and had a number of uniform microcracks on the surface. The effects of initial quinoline concentration, light intensity, reaction temperature, aeration, and initial pH were studied. Increased reaction time, light intensity, environmental temperature, and gas aeration were found to significantly improve the quinoline removal efficiency. The aeration effect of oxygen dependency on the quinoline degradation had the trend pure oxygen > air > no gas > pure nitrogen with free O2. The solution pH crucially affected quinoline photodegradation; the high electrostatic adsorption of quinoline molecules on the TiO2 surface was strongly pH dependent. 2-Pyridine-carboxaldehyde, 3-pyridinecarboxaldehyde, and 2(1H)-quinolinone were identified as the major intermediates of quinoline degradation. Based on these intermediates, a primary degradation mechanism was proposed. This reusable P25 film benefits the photodegradation of water contaminants and has potential in other various applications.
PCR and Magnetic Bead-Mediated Target Capture for the Isolation of Short Interspersed Nucleotide Elements in Fishes
Authors: Liu Dong , Zhu Guoli , Tang Wenqiao , Yang Jinquan , Guo Hongyi
Published: February 2012

Short interspersed nucleotide elements (SINEs), a type of retrotransposon, are widely distributed in various genomes with multiple copies arranged in different orientations, and cause changes to genes and genomes during evolutionary history. This can provide the basis for determining genome diversity, genetic variation and molecular phylogeny, etc. SINE DNA is transcribed into RNA by polymerase III from an internal promoter, which is composed of two conserved boxes, box A and box B. Here we present an approach to isolate novel SINEs based on these promoter elements. Box A of a SINE is obtained via PCR with only one primer identical to box B (B-PCR). Box B and its downstream sequence are acquired by PCR with one primer corresponding to box A (A-PCR). The SINE clone produced by A-PCR is selected as a template to label a probe with biotin. The full-length SINEs are isolated from the genomic pool through complex capture using the biotinylated probe bound to magnetic particles. Using this approach, a novel SINE family, Cn-SINE, from the genomes of Coilia nasus, was isolated. The members are 180–360 bp long. Sequence homology suggests that Cn-SINEs evolved from a leucine tRNA gene. This is the first report of a tRNALeu-related SINE obtained without the use of a genomic library or inverse PCR. These results provide new insights into the origin of SINEs.
Neuroprotective Effects of Pre-Treament with l-Carnitine and Acetyl-l-Carnitine on Ischemic Injury In Vivo and In Vitro
Authors: Zhang Rui , Zhang Hong , Zhang Zhongxia , Wang Tao , Niu Jingya , Cui Dongsheng , Xu Shunjiang
Published: February 2012

The therapeutic effect of stroke is hampered by the lack of neuroprotective drugs against ischemic insults beyond the acute phase. Carnitine plays important roles in mitochondrial metabolism and in modulating the ratio of coenzyme A (CoA)/acyl-CoA. Here, we investigate the neuroprotective effects of l-carnitine (LC) and Acetyl-l-carnitine (ALC) pre-treatment on ischemic insults under the same experimental conditions. We used a transient middle cerebral artery occlusion (MCAO) model to evaluate the protective roles of LC and ALC in acute focal cerebral ischemia in vivo and to understand the possible mechanisms using model of PC12 cell cultures in vitro. Results showed that ALC, but not LC, decreased infarction size in SD rats after MCAO in vivo. However, both LC and ALC pretreatment reduced oxygen-glucose deprivation (OGD)-induced cell injury and decreased OGD-induced cell apoptosis and death in vitro; at the same time, both of them increased the activities of super oxide dismutase (SOD) and ATPase, and decreased the concentration of malondialdehyde (MDA) in vitro. Thus, our findings suggested that LC and ALC pre-treatment are highly effective in the prevention of neuronal cell against ischemic injury in vitro, however, only ALC has the protective effect on neuronal cell injury after ischemia in vivo.
Investigation of Phenolic Acids in Suspension Cultures of Vitis vinifera Stimulated with Indanoyl-Isoleucine, N-Linolenoyl-L-Glutamine, Malonyl Coenzyme A and Insect Saliva
Authors: Riedel Heidi , Akumo Divine N. , Saw Nay Min Min Thaw , Smetanska Iryna , Neubauer Peter
Published: February 2012

Vitis vinifera c.v. Muscat de Frontignan (grape) contains various high valuable bioactive phenolic compounds with pharmaceutical properties and industrial interest which are not fully exploited. The focus of this investigation consists in testing the effects of various biological elicitors on a non-morphogenic callus suspension culture of V. vinifera. The investigated elicitors: Indanoyl-isoleucine (IN), N-linolenoyl-L-glutamine (LG), insect saliva (IS) and malonyl coenzyme A (MCoA) were aimed at mimicking the influence of environmental pathogens on plants in their natural habitats and at provoking exogenous induction of the phenylpropanoid pathway. The elicitors’ indanoyl-isoleucine (IN), N-linolenoyl-L-glutamine (LG) and insect saliva (IS), as well as malonyl coenzyme A (MCoA), were independently inoculated to stimulate the synthesis of phenylpropanoids. All of the enhancers positively increased the concentration of phenolic compounds in grape cells. The highest concentration of phenolic acids was detected after 2 h for MCoA, after 48 h for IN and after 24 h for LG and IS respectively. At the maximum production time, treated grape cells had a 3.5-fold (MCoA), 1.6-fold (IN) and 1.5-fold (IS) higher phenolic acid content compared to the corresponding control samples. The HPLC results of grape cells showed two major resveratrol derivatives: 3-O-Glucosyl-resveratrol and 4-(3,5-dihydroxyphenyl)-phenol. Their influences of the different elicitors, time of harvest and biomass concentration (p < 0.0001) were statistically significant on the synthesis of phenolic compounds. The induction with MCoA was found to demonstrate the highest statistical effect corresponding to the strongest stress response within the phenylpropanoid pathway in grape cells.
Fructose Might Contribute to the Hypoglycemic Effect of Honey
Authors: Erejuwa Omotayo O. , Sulaiman Siti A. , Wahab Mohd S. Ab
Published: February 2012

Honey is a natural substance with many medicinal properties, including antibacterial, hepatoprotective, hypoglycemic, antioxidant and antihypertensive effects. It reduces hyperglycemia in diabetic rats and humans. However, the mechanism(s) of its hypoglycemic effect remain(s) unknown. Honey comprises many constituents, making it difficult to ascertain which component(s) contribute(s) to its hypoglycemic effect. Nevertheless, available evidence indicates that honey consists of predominantly fructose and glucose. The objective of this review is to summarize findings which indicate that fructose exerts a hypoglycemic effect. The data show that glucose and fructose exert a synergistic effect in the gastrointestinal tract and pancreas. This synergistic effect might enhance intestinal fructose absorption and/or stimulate insulin secretion. The results indicate that fructose enhances hepatic glucose uptake and glycogen synthesis and storage via activation of hepatic glucokinase and glycogen synthase, respectively. The data also demonstrate the beneficial effects of fructose on glycemic control, glucose- and appetite-regulating hormones, body weight, food intake, oxidation of carbohydrate and energy expenditure. In view of the similarities of these effects of fructose with those of honey, the evidence may support the role of fructose in honey in mediating the hypoglycemic effect of honey.
Synthesis and Characterization of Hybrid Molecularly Imprinted Polymer (MIP) Membranes for Removal of Methylene Blue (MB)
Authors: Asman Saliza , Yusof Nor Azah , Abdullah Abdul Halim , Haron Md Jelas
Published: February 2012

This work reports the synthesis and characterization of a hybrid molecularly imprinted polymer (MIP) membrane for removal of methylene blue (MB) in an aqueous environment. MB-MIP powders were hybridized into a polymer membrane (cellulose acetate (CA) and polysulfone (PSf)) after it was ground and sieved (using 90 µm sieve). MB-MIP membranes were prepared using a phase inversion process. The MB-MIP membranes were characterized using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM). Parameters investigated for the removal of MB by using membrane MB-MIP include pH, effect of time, concentration of MB, and selectivity studies. Maximum sorption of MB by PSf-MB-MIP membranes and CA-MB-MIP membranes occurred at pH 10 and pH 12, respectively. The kinetic study showed that the sorption of MB by MB-MIP membranes (PSf-MB-MIP and CA-MB-MIP) followed a pseudo-second-order-model and the MB sorption isotherm can be described by a Freundlich isotherm model.
An Adaptive Single-Well Stochastic Resonance Algorithm Applied to Trace Analysis of Clenbuterol in Human Urine
Authors: Wang Wei , Xiang Suyun , Xie Shaofei , Xiang Bingren
Published: February 2012

Based on the theory of stochastic resonance, an adaptive single-well stochastic resonance (ASSR) coupled with genetic algorithm was developed to enhance the signal-to-noise ratio of weak chromatographic signals. In conventional stochastic resonance algorithm, there are two or more parameters needed to be optimized and the proper parameters values were obtained by a universal searching within a given range. In the developed ASSR, the optimization of system parameter was simplified and automatic implemented. The ASSR was applied to the trace analysis of clenbuterol in human urine and it helped to significantly improve the limit of detection and limit of quantification of clenbuterol. Good linearity, precision and accuracy of the proposed method ensure that it could be an effective tool for trace analysis and the improvement of detective sensibility of current detectors.
Host-Defense Activities of Cyclotides
Authors: Craik David J.
Published: February 2012

Cyclotides are plant mini-proteins whose natural function is thought to be to protect plants from pest or pathogens, particularly insect pests. They are approximately 30 amino acids in size and are characterized by a cyclic peptide backbone and a cystine knot arrangement of three conserved disulfide bonds. This article provides an overview of the reported pesticidal or toxic activities of cyclotides, discusses a possible common mechanism of action involving disruption of biological membranes in pest species, and describes methods that can be used to produce cyclotides for potential applications as novel pesticidal agents.
Rainforest conifers of Eocene Patagonia: Attached cones and foliage of the extant Southeast Asian and Australasian genusDacrycarpus(Podocarpaceae)
Authors: Wilf Peter
Published: February 2012

•Premise of the study:Eocene caldera‐lake beds at Laguna del Hunco (LH, ca. 52.2 Ma) and Río Pichileufú (RP, ca. 47.7 Ma) in Argentine Patagonia provide copious information about the biological history of Gondwana. Several plant genera from these sites are known as fossils from southern Australia and New Zealand and survive only in Australasian rainforests. The potential presence ofDacrycarpus(Podocarpaceae) holds considerable interest due to its extensive foliage‐fossil record in Gondwana, its remarkably broad modern distribution in Southeast Asian and Australasian rainforests, its high physiological moisture requirements, and its bird‐dispersed seeds. However, the unique seed cones that firmly diagnoseDacrycarpuswere not previously known from the fossil record.

•Methods:I describe and interpret fertile (LH) and vegetative (LH and RP) material ofDacrycarpusand present a nomenclatural revision for fossilDacrycarpusfrom South America.

•Key results: Dacrycarpus puertaesp. nov. is the first fossil occurrence of the unusual seed cones that typify livingDacrycarpus, attached to characteristic foliage, and of attachedDacrycarpuspollen cones and foliage.Dacrycarpus puertaeis indistinguishable from livingD. imbricatus(montane, Burma to Fiji).Dacrycarpus chilensis(Engelhardt) comb. nov. is proposed for Eocene vegetative material from Chile.

•Conclusions:Modern‐aspectDacrycarpuswas present in Eocene Patagonia, demonstrating an astonishingly wide‐ranging paleogeographic history and implying a long evolutionary association with bird dispersers.Dacrycarpus puertaeprovides the first significant Asian link for Eocene Patagonian floras, strengthens the biogeographic connections from Patagonia to Australasia across Antarctica during the warm Eocene, and indicates high‐rainfall paleoenvironments.
Phylogeny of the tribe Fumarieae (Papaveraceae s.l.) based on chloroplast and nuclear DNA sequences: Evolutionary and biogeographic implications
Authors: Pérez‐Gutiérrez Miguel A. , Romero‐García Ana T. , Salinas María J. , Blanca Gabriel , Fernández M. Carmen , Suárez‐Santiago Víctor N.
Published: February 2012

• Premise of the Study: Little research has been done at the molecular level on the tribe Fumarieae (Papaveraceae). Papaveraceae is a model plant group for studying evolutionary patterns despite the lack of a reference phylogeny for this tribe. We investigated the phylogenetic relationships within the tribe to complete the molecular data for this family in order to help understand its character evolution and biogeographic pattern.

• Methods: We used maximum‐parsimony and Bayesian approaches to analyze five DNA regions for 25 species representing 10 of the 11 Fumarieae genera and five outgroups. Evolutionary pathways of four characters (habit, life span, type of fruit, and number of seeds per fruit) were inferred on the phylogeny using parsimony. The ancestral distribution areas were reconstructed using dispersal–vicariance analysis.

• Key Results: Fumarieae is monophyletic and includes three groups that agree with the morphology‐based subtribes: Discocapninae, Fumariinae, and Sarcocapninae. Within subtribes, the relationships among genera were different from those obtained with morphological data. Annual life span, nonchasmophytic habit, and a several‐seeded capsule were the basal character states for the tribe. The ancestor occupied a continuous area between West Eurasia and Africa. Vicariances explain the divergence between lineages Discocapninae (South Africa) and Fumariinae–Sarcocapninae (Mediterranean), and the disjunction of Fumariinae (Mediterranean–Central Asia).

• Conclusions: Molecular phylogeny confirms the subtribal classification of Fumarieae based on morphology. However it provides different results regarding the relationships among genera within each subtribe, which affects the inference of the evolutionary pathway followed by the four selected characters. The disjunct distribution of the tribe is explained by different vicariance scenarios.
Derivatives of phenyl tribromomethyl sulfone as novel compounds with potential pesticidal activity
Authors: Borys Krzysztof M , Korzyński Maciej D , Ochal Zbigniew
Published: February 2012

A halogenmethylsulfonyl moiety is incorporated in numerous active herbicides and fungicides. The synthesis of tribromomethyl phenyl sulfone derivatives as novel potential pesticides is reported. The title sulfone was obtained by following three different synthetic routes, starting from 4-chlorothiophenol or 4-halogenphenyl methyl sulfone. Products of its subsequent nitration were subjected to the SNAr reactions with ammonia, amines, hydrazines and phenolates to give 2-nitroaniline, 2-nitrophenylhydrazine and diphenyl ether derivatives. Reduction of the nitro group of 4-tribromomethylsulfonyl-2-nitroaniline yielded the corresponding o-phenylenediamine substrate for preparation of structurally varied benzimidazoles.
Antimicrobial resistance in non-typhi Salmonella enterica isolated from humans and poultry in Palestine
Authors: AL-Dawodi Rula , Farraj Mohammad A , Essawi Tamer
Published: February 2012

Introduction: The efficacy of chemotherapy can be compromised by drug resistance.  This study was undertaken to describe the resistance profiles and fluoroquinolone resistance mechanism of non-typhoidal Salmonella (NTS) isolated from humans and poultry in West Bank, Palestine. Methodology: One hundred and fifty-one isolates of NTS, obtained from humans (71) and poultry (80), collected between September 2005 and January 2007, were tested for susceptibility to ampicillin, gentamicin, tetracycline ceftriaxone, nalidixic acid and ciprofloxacin. Mutation patterns within gyrA were determined by direct sequencing or by digestion of PCR-amplified DNA fragments with the restriction enzyme HinfI. Results: Resistance rates among human and poultry isolates were respectively 59% and 51% for ampicillin, 31% and 10% for gentamicin, 59% and 80% for tetracycline, 59% and 45% for nalidixic acid, and 30% and 15% for ciprofloxacin. All the isolates were susceptible to ceftriaxone. Mutations at positions 83 and/or 87 were detected in gyrA of isolates with resistance to nalidixic acid. Isolates which were resistant to nalidixic acid but susceptible to ciprofloxacin had a single gyr A gene mutation at point 87.  This gene mutation was sufficient to induce a new phenotype (6 isolates) with decreased susceptibility to ciprofloxacin. Conclusion: Mutations in gyrA at positions 83 or 87 were the most prevalent mutation pattern of fluoroquinolone resistant NTS isolates but other unknown mechanisms are also present. Continued surveillance of antimicrobial resistance among NTS isolates is needed to mitigate the increasing prevalence of quinolone resistance.
Five-year evaluation of the antimicrobial susceptibility patterns of bacteria causing bloodstream infections in Iran
Authors: Pourakbari Babak , Sadr Alireza , Haghi Ashtiani Mohammad Taghi , Mamishi Setareh , Dehghani Mahdi , Mahmoudi Shima , Salavati Ali , Asgari Farhad
Published: February 2012

Introduction: Bloodstream infections (BSI) are a serious cause of morbidity and mortality worldwide. Emerging antimicrobial drug resistance among bacterial pathogens causing BSI can limit therapeutic options and complicate patient management. Methodology: To encourage the prudent use of appropriate antibiotics in our pediatric population at Children's Medical Center Hospital, Tehran, Iran, we studied the frequency and antibiogram patterns of blood culture isolates from January 2001 to December 2005. Results: Of 25,223 blood cultures examined, 2,581 (10.23 %) were positive for bacterial growth. The frequency of Gram-positive bacteria isolated was 47.6% (1228 of 2581) and that for Gram-negatives was 52.4% (1353 of 2581). The rates of methicillin (oxacillin) resistance in Staphylococcus aureus and coagulase-negative staphylococci (CoNS) were 79% and 89%, respectively. About 45% of Streptococcus pneumoniae were resistant to trimethoprim-sulfamethoxazole and approximately 66% to penicillin. Among the Gram-negative isolates, Pseudomonas aeruginosa was most frequently isolated, representing 943 (36.7%) over five years. This possibly represents an unrecognized hospital outbreak or contamination of blood culture bottles or other products such as skin disinfectants. Additionally, this pathogen showed extremely high rates of antimicrobial resistance. There were notable differences in frequency of the five most common microorganisms isolated from blood cultures, which can help set priorities for focused infection control efforts. Conclusions: Our findings underscore the need to monitor blood culture isolates and their antimicrobial resistance patterns to observe resistance trends that would influence appropriate empiric treatment and infection control strategies for bacteremic children.
Antimicrobial resistance of Escherichia coli in Mexico: How serious is the problem?
Authors: Murillo Llanes Joel , Varon Joseph , Velarde Félix Jesús Salvador , González-Ibarra Fernando Pavel
Published: February 2012

Introduction: This study aimed to determine the resistance patterns of Escherichia coli (E. coli) in Mexico to several antibiotics and research some therapeutic options. Methodology: Positive cultures for E. coli isolated from bronchial secretions, urine, central catheter, blood, and infected wounds in the Culiacan General Hospital, Sinaloa, Mexico from 30 June 2004 to 1 July 2007 were studied. Resistance against multiple antibiotics was measured and compared by gender and the hospital unit where the bacteria were isolated. Results: In total, 1511 specimens were analyzed from men (45.4%) and women (54.5%), of which 251 were positive for E. coli. Antimicrobial resistance was highest in the neurosurgery service (58.4%). Samples included sputum (14.7%), bronchial secretions (17.9%), wounds (35.4%), urine/Foley catheter tip (35.5%), central catheter tips (5.6%), and blood cultures (7.2%). Resistance to ampicillin was highest at 91% followed by ciprofloxacin at 80.6%, trimethoprim-sulfamethoxazole at 70.2%, piperacillin/tazobactam at 14.4%, and imipenem at 6.8%. Conclusions: Trimethoprim should not be recommended as an empiric option for E. coli infections and the benefit of quinolones is low. It is important to understand the resistance of the bacteria in each medical center, consider its frequency in each service within the same hospital, and take all necessary measures to ensure and create a clinical attitude of prevention.
Prevalence of severe acute rotavirus gastroenteritis and intussusceptions in Ghanaian children under 5 years of age
Authors: Enweronu-Laryea Christabel C , Sagoe Kwamena W.C. , Glover-Addy Hope , Asmah Richard H , Mingle Julius A , Armah George E
Published: February 2012

Introduction: Vaccination is the most effective preventive strategy against rotavirus disease. Regional differences in prevalent rotavirus genotypes may affect vaccine efficacy. Pre-vaccine surveillance for burden of rotavirus disease, prevalent rotavirus genotypes, and association between rotavirus disease and intussusceptions helps in monitoring the impact of vaccination. Methodology: A prospective study was conducted from January 2008 to December 2009 in children younger than five years hospitalized for longer than 24 hours with acute gastroenteritis. Data on confirmed cases of intussusception were collected retrospectively. Stools were tested by enzyme immunoassay, reverse-transcriptase polymerase chain reaction and nucleotide sequencing.  Results: Acute gastroenteritis (AGE) caused 13.1% (2,147/16,348) of hospitalizations among children under five years. Stools were tested for 50.2% (1077/2147) of AGE cases. Of these, 49% (528/1077) were rotavirus positive. Rotavirus gastroenteritis, non-rotavirus gastroenteritis, and intussusceptions were most prevalent in children under 15 months [80.3%, 74% and 91% respectively]. Rotavirus was detected from more than 60% of acute gastroenteritis cases during peak months. The prevalence of intussusception showed no seasonal pattern. The peak ages of six to twelve months for acute gastroenteritis and five to eight months for intussusception overlapped. G1, G2 and mixed G/P genotypes were common in the isolated rotaviruses. Conclusion: Rotavirus gastroenteritis causes significant morbidity in children younger than five years of age in Ghana. Although the peak age of rotavirus gastroenteritis and intussusceptions overlapped, there was no seasonal correlation between them. The high prevalence of mixed G/P genotypes in Ghanaian children may affect the effectiveness of vaccination.
Report of two rare complications of pandemic influenza A (H1N1)
Authors: Babamahmoodi Farhang , Davoodi Ali Reza , Ghasemian Roya , Delavarian Leila
Published: February 2012

Novel influenza A (H1N1) has created a major worldwide health problem within a short time after its emergence. This infection is often self-limited, but sometimes can cause severe and fatal complications. In this study, we present two rare complications of pandemic influenza A, who were referred to Razi University Affiliated Hospital in northern Iran. The first case was a 30-year-old man with severe headache and high fever accompanied with chills, generalized myalgia, and arthralgia. Cerebrospinal fluid analysis was consistent with aseptic meningitis. The second case, a 25-year-old pregnant woman with high fever, chills and severe fatigue and malaise, developed tachypnea, tachycardia, respiratory distress, cyanosis and loss of consciousness a few hours after admission. Echocardiography reported myopericarditis. The patient was transferred to the intensive care unit and mechanical ventilation was begun. The next day, the patient started vaginal bleeding which progressed to spontaneous abortion three days later. Diagnosis of novel influenza A (H1N1) was confirmed using real-time reverse-transcriptase PCR of a pharyngeal swab.
Prevalence and genetic characteristics of Shigatoxigenic Escherichia coli from patients with diarrhoea in Maasailand, Kenya
Authors: Sang Willie Kipkemboi , Boga Hamadi Iddi , Waiyaki Peter Gichuhi , Schnabel David , Wamae Njeri C , Kariuki Sam M
Published: February 2012

Introduction: Shigatoxigenic Escherichia coli strains are food-borne bacterial pathogens that may cause haemorrhagic colitis (HC) in humans which can lead to life-threatening systemic complication, including haemolytic uremic syndrome (HUS). This study aimed to characterize and analyze virulence properties of pathogenic E. coli isolates among patients with diarrhoea from a Maasai community in Kenya. Methodology: Stool samples from 380 patients of all ages from the Kajiado and Narok districts of Kenya were investigated for the presence of enteric bacterial pathogens by conventional and molecular methods. Results: Bacterial diarrhoea was diagnosed in 141/380 (37.1%) cases, of which enterotoxigenic E. coli (ETEC) compromised 29.8%, shigatoxigenic E. coli (STEC) 24.1%, enteroaggregative E. coli (EAEC) 14.2%, enteroinvasive E. coli (EIEC) 12.8% and enteropathogenic E. coli (EPEC) 3.5%. Gene analysis for STEC virulence factors showed that 52.9% isolates carried stx1, 29.4% possessed stx2, 14.7% carried both stx1 and stx2, and 2.9% had stx2e. 23.5% isolates carried enterohaemolysin and 20.5% isolates possessed the Intimin gene. From 9 strains that exhibited adherence, 7 contained both Intimin and Haemolysin genes. Infections with Intimin-positive STEC strains (46%) were more frequent in patients with bloody diarrhoea, especially in children under 5 years of age, whereas Intimin-negative STEC infections dominated in adults. Conclusion: Although STEC infection as a cause of bloody diarrhoea has not attracted much attention as a medical problem in Kenya, our findings indicate that this is a problem that must be investigated. The 24.1% isolation rate of STEC among the Maasai is one of the highest reported rates worldwide.