bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes, perturbations, and responses in geomorphic systems
Authors: Phillips Jonathan D.
Published: May 2009

In recent decades views of change, disturbance, response, and recovery in geomorphology have expanded considerably. Conceptual frameworks emphasizing single-path, single-outcome trajectories of change have been supplemented — not replaced — by multi-path, multi-outcome perspectives. Geomorphology has also seen a transition from the idea of normative standards such as characteristic, (steady-state) equilibrium, zonal, and mature forms to the recognition that some systems may have multiple potential characteristic or equilibrium forms — and that some may have no particular normative state at all. These trends are not presented as a replacement of outmoded ideas, but rather as a broadening of approaches. The single-path single-outcome frameworks can generally be viewed as special cases of the broader pluralistic analytical structures. In this context, two perspectives — an adaptation of White's hazards matrix, and the landscape sensitivity concept — are suggested which lend themselves to studies of recent and contemporary changes in earth surface systems. These perspectives can be synthesized into a framework for the assessment of geomorphic changes and responses based on the `four Rs': response (reaction and relaxation times), resistance (relative to the drivers of change), resilience (recovery ability, based on dynamical stability), and recursion (positive and/or negative feedbacks).
Sensitivity of direct radiative forcing by mineral dust to particle characteristics
Authors: Durant Adam J. , Harrison Sandy P. , Watson I. Matthew , Balkanski Y.
Published: May 2009

Airborne dust affects the Earth's energy balance — an impact that is measured in terms of the implied change in net radiation (or radiative forcing, in W m-2) at the top of the atmosphere. There remains considerable uncertainty in the magnitude and sign of direct forcing by airborne dust under current climate. Much of this uncertainty stems from simplified assumptions about mineral dust-particle size, composition and shape, which are applied in remote sensing retrievals of dust characteristics and dust-cycle models. Improved estimates of direct radiative forcing by dust will require improved characterization of the spatial variability in particle characteristics to provide reliable information dust optical properties. This includes constraints on: (1) particle-size distribution, including discrimination of particle subpopulations and quantification of the amount of dust in the sub-10 µm to <0.1 µm mass fraction; (2) particle composition, specifically the abundance of iron oxides, and whether particles consist of single or multi-mineral grains; (3) particle shape, including degree of sphericity and surface roughness, as a function of size and mineralogy; and (4) the degree to which dust particles are aggregated together. The use of techniques that measure the size, composition and shape of individual particles will provide a better basis for optical modelling.
Environmental effects of drainage, drain-blocking and prescribed vegetation burning in UK upland peatlands
Authors: Ramchunder S.J. , Brown L.E. , Holden J.
Published: May 2009

Peatlands are important ecosystems for carbon (C) storage, provision of water resources and biodiversity. UK blanket peats represent 10—15% of those found worldwide. While many peatlands continue to be managed through artificial drainage and vegetation burning, it has long been recognized that local habitats and ecological diversity are strongly influenced by these practices. This paper reviews the hydrological, physicochemical and ecological effects of three widespread UK peatland management practices, namely artificial drainage, drain-blocking and rotational heather burning. Drainage and burning of peat often lead to altered runoff regimes, oxidation of organic matter, changes to C, nitrogen (N) and phosphorus (P) cycling, and increased metal and suspended sediment concentrations in streams relative to intact peatlands. Although artificial drainage is now rarely implemented on UK upland peats, a great number of historical drains remain, thus drain-blocking is increasingly being applied to restore many peatlands. In contrast, recent increases in the intensity and extent of rotational heather burning may result in further changes to peatland ecosystems. Relatively little is known about the environmental effects of rotational heather burning compared with drainage and drain-blocking management, and for all three of these management techniques there is scarce information on river ecosystem response. We hypothesize some likely effects of basin-scale drainage, drain-blocking and heather burning on stream ecosystems and illustrate these with a schematic model. Such a holistic consideration of peatland river basins is particularly timely with respect to the implementation of the EU Water Framework Directive.
Bathymetric mapping by means of remote sensing: methods, accuracy and limitations
Authors: Gao Jay
Published: May 2009

Bathymetry has been traditionally charted via shipboard echo sounding. Alhough able to generate accurate depth measurements at points or along transects, this method is constrained by its high operating cost, inefficiency, and inapplicability to shallow waters. By comparison, remote sensing methods offer more flexible, efficient and cost-effective means of mapping bathymetry over broad areas. Remote sensing of bathymetry falls into two broad categories: non-imaging and imaging methods. The non-imaging method (as typified by LiDAR) is able to produce accurate bathymetric information over clear waters at a depth up to 70 m. However, this method is limited by the coarse bathymetric sampling interval and high cost. The imaging method can be implemented either analytically or empirically, or by a combination of both. Analytical or semi-analytical implementation is based on the manner of light transmission in water. It requires inputs of a number of parameters related to the properties of the atmosphere, water column, and bottom material. Thus, it is rather complex and difficult to use. By comparison, empirical implementation is much simpler and requires the input of fewer parameters. Both implementations can produce fine-detailed bathymetric maps over extensive turbid coastal and inland lake waters quickly, even though concurrent depth samples are essential. The detectable depth is usually limited to 20 m. The accuracy of the retrieved bathymetry varies with water depth, with the accuracy substantially lower at a depth beyond 12 m. Other influential factors include water turbidity and bottom materials, as well as image properties.
Gestural Enthymemes
Authors: Newman Sara
Published: May 2009

This article contributes to recent efforts to add life and movement to rhetorical studies by focusing on the representation of movement in medical texts. More specifically, this study examines medical texts, illustrations, and photographs involving movement by Johann Casper Lavater, G. B. Duchenne de Bologne, Charles Darwin, and Étienne-Jules Marey. By identifying how figures of speech epitomize arguments, this examination follows a shift in the way arguments about movement are represented, a shift from static, visual arguments to gestural enthymemes, as they are named, arguments that are made in movements; these shifts are linked to developments in medical technologies involving photography. These arguments about and using movement attempt to “capture” or express the moments within which life, through the embodied gesture, resides. This extended understanding of the enthymeme broadens current understanding of argument to include delivery, links medical and rhetorical discursive practices, and informs how we make sense of and study the relationships between technology and rhetoric both in the past and present.
A Novel Osteochondral Scaffold Fabricated via Multi-nozzle Low-temperature Deposition Manufacturing
Authors: Liu Li , Xiong Zhuo , Zhang Renji , Jin Le , Yan Yongnian
Published: May 2009

A functional-region/separate-interface/single-cell-type of tissue engineering pathway was evaluated to regenerate osteochondral defects that are deep in the marrow cavity. A gradient osteochondral scaffold fabricated via a rapid prototyping technology, called multi-nozzle low-temperature deposition manufacturing, was composed of three parts with different materials and pore-structures, respectively, for bone, cartilage and a separate interface between them. The separate interface was composed of micro-pores, that were less than 5 urn and with low porosity, to reduce or to avoid the destruction of the micro-environment in vivo by preventing blood and cells and reducing the amount of oxygen and nutrients moving from the marrow cavity to the articulate marrow. The preliminary results after 6 weeks of implantation into 4 mm diameter osteochondral defects in the knee joints of rabbits showed that the defects with the scaffold/cells composition had bone-like or cartilage-like tissue filling the defects with smooth surface, while the defects with nothing (blank) showed only fibrous tissue.
Design and Evaluation of a Cell Microencapsulating Device for Cell Assembly Technology
Authors: Yao Rui , Zhang Renji , Wang Xiaohong
Published: May 2009

A cell encapsulation device based on the principle of high-voltage dispersion technology was designed and constructed. The parameters that influenced the formation of cell microcapsules, such as; voltage, push speed, electrode distance, and syringe size were analyzed and optimized. Unlike the traditional cell microencapsulating devices, both of the electrodes were separated from the CaCl2 solution in this device, which simplified the procedure of keeping the operation within a sanitary environment. Integrated adipose derived stem cell (ADSC) microcapsules with smooth surface and consistent diameter distribution were prepared. After 1-week in culture as a microcapsule and 3 days assembled in a construct, the ADSCs maintained a high viability and significant proliferation that established a favorable basis for the controlled assembly of cell microcapsules.
Design and Preparation of an Electrospun Biomaterial Surgical Patch
Authors: Lu Hai , Chen Wei-Jun , Xing Yan , Ying Da-Jun , Jiang Bo
Published: May 2009

A biomaterial patch of electrospun collagen type fibers was designed and produced by electrospinning seven different concentrations (8%-20% w/v) of collagen solutions. The tensile strength, yield strength, and elastic modulus of the electrospun collagen fibrous patches were found to be suitable for clinical transplantation. No significant differences versus fresh porcine pericardium as controls were observed. The SEM images of the groups showed that the patches were smooth with uniform interwoven and porous morphology. The fibrous patches were biocompatible and did not elicit local or systemic toxic effects when implanted in vivo. These electrospun collagen fibrous patches have significant potential as surgical biomaterial patches.
Branched Channel Scaffolds Fabricated by SFF for Direct Cell Growth Observations
Authors: Xu Shanglong , Yang Yue , Wang Xibin , Wang Chaofeng
Published: May 2009

A β-TCP scaffold with a branched channel system was designed to create a novel micro-device that allowed culture perfusion and direct time observation of the cells attached. The scaffold was made by indirect solid free form fabrication (SFF) technology. The flow channel structure was exposed so that the perfusion of the mesenchymal stem cell (MSC) culture could be viewed directly. The cell-seeded scaffolds were continuously perfused for 7 days in the micro-device; during this time, it was possible to observe the dynamic culture processes with cells adhering to the scaffolds and real time cell growth directly. This concept has great potential for use in bone tissue engineering and for versatile fabrication of enhanced scaffolds.
Fabrication and in Vitro Evaluation of Calcium Phosphate Combined with Chitosan Fibers for Scaffold Structures
Authors: Lian Qin , Li Dichen , Jin Zhongmin , Wang Jue , Li Aimin , Wang Zhen , Jin Zhongmin
Published: May 2009

A rapid prototyping and rapid tool technique-based method was developed to fabricate chitosan fiber calcium phosphate cement composites (CF/CPC) for bone tissue engineering scaffold applications. The products were characterized and the in vitro performance with canine bone marrow stem cells (BMCs) on CF/CPC scaffold with controlled fiber structures evaluated. The X-ray diffraction analysis showed that about 91% of the inorganic part of the CF/CPC scaffold was hydroxyapatite (HA) and the variation in CF had little effect on the percentage of HA content. The results from in vitro study demonstrated that the interconnected macropores rapidly formed inside the CF/CPC scaffolds and that the patterns were related to the fiber structures used. The differences in the fiber structures altered the morphology of the BMCs without affecting the proliferation of the BMCs.
Biocompatibility Evaluation of Chitosan-based Injectable Hydrogels for the Culturing Mice Mesenchymal Stem Cells In Vitro
Authors: Yan Jihong , Yang Liu , Wang Guirong , Xiao Yang , Zhang Baohong , Qi Nianmin
Published: May 2009

A thermosensitive polymer can be held liquid before being injected to deliver living cells or therapeutic agents and formed monolithic gels when injected in vivo. In this study, chitosan-based thermosensitive hydrogels were prepared, characterized and the biocompatibility for culturing mice bone mesenchymal stem cells (BMSC) on 2D films and within 3D hydrogel were investigated. The gelation temperature and biocompatibility could be modulated by addition hydroxyethyl cellulose (HEC) to chitosan—glycerophosphate (CH—GP) formulation. The CH—GP—HEC liquid solution can turn into gel at body temperature and has highly compatible with BMSC. Therefore, the CH—GP—HEC gel could be used as an attractive injected in-situ forming scaffold for future applications of delivering biologically active therapeutics for tissue engineering filed.
Asymmetry in the Science and Technology Base and Its Bearing on Regional Development
Authors: Shukla Rajesh , Satish N.G. , Rao P. Rama
Published: May 2009

It was envisaged in the Science Policy Resolution (SPR), which Nehru got the Parliament to approve in 1958, that the country would participate fully in the march of science. However, as we celebrate the golden jubilee of the pioneering SPR, it is discomforting to note that just as there are economic disparities, the science and technology (S&T) scenario also presents glaring regional imbalances in the country. This paper examines asymmetries in S&T development across the states in terms of category–wise spread of research institutions. The paper further studies what bearing S&T institutional disparities have, if any, on regional economic development with the help of an extensive dataset developed for the purpose. The results of the study suggest a notable correlation between S&T development and the economic and welfare status of different regions of the country.
Numerical Analysis of Concrete Fracture
Authors: Sageresan N. , Drathi R. , Anjali P.S.
Published: May 2009

Fracture in concrete is determined by excessive cracking. Numerical analysis of concrete fracture is either based on smeared crack method or discrete crack method. Smeared crack method is easier to implement than the discrete crack method but is therefore less accurate and applicable only for specific problems. We study fracture of concrete by a simplified meshless discrete crack method. The method exploit the advantages of smeared crack method and maintains the accuracy of discrete crack method. The discrete crack is modeled by set of crack segments that can be arbitrarily placed in the meshless discretization. Neo-Hooke material is used in the bulk material and cohesive zone model once the discrete crack occurs. We demonstrate for mode-I and mixed mode failure the accuracy of the meshless discrete crack method.
Organizational Service Climate Drivers of the American Customer Satisfaction Index (ACSI) and Financial and Market Performance
Authors: Schneider Benjamin , Macey William H. , Lee Wayne C. , Young Scott A.
Published: May 2009

The climate for service is conceptualized and studied as a correlate of customer satisfaction and corporate financial and market performance, with customer satisfaction as a mediator of the climate-performance relationship. Brief reviews of relevant literatures yield three hypotheses: (1) customer satisfaction will be a significant correlate of organizational financial and market performance, (2) organizational service climate will be a significant correlate of organizational customer satisfaction, and (3) customer satisfaction will mediate the relationship between service climate and financial and market performance. The hypothesized relationships are supported in a 3-year longitudinal study of Fortune 200 service companies (not units within companies) from diverse service sectors with path analyses supporting full mediation for customer satisfaction in the link between service climate and corporate financial and market performance. Management implications for corporate competitive advantage through a focus on service climate are discussed.
Abdominal compartment syndrome — the new killer
Authors: Searle RD , Wenham TN , Garner JP
Published: May 2009

Abdominal compartment syndrome (ACS) results from an increase in intra-abdominal pressure (IAP) within the relatively fixed confines of the abdominal cavity. This increase in abdominal pressure can have deleterious consequences on multiple organ systems and amongst the intensive care population is associated with increased morbidity and mortality. Trauma victims commonly have multiple risk factors for the development of ACS, yet in the past routine measurement of IAP in intensive care patients in the UK has been variable. Recent consensus guidelines have helped to clarify the identification, diagnosis and management of patients at risk of ACS.
Steps to a Healthier Salinas
Authors: Hanni Krista D. , Garcia Elan , Ellemberg Cheryl , Winkleby Marilyn
Published: May 2009

As part of a 5-year community-based intervention in Salinas, California, the Steps to a Healthier Salinas team developed a taqueria intervention addressing obesity and diabetes among Mexican Americans. The authors present: (a) a comparison of service/entrée options for Salinas taquerias (n = 35) and fast-food restaurants ( n = 38) at baseline, (b) a case study of one taqueria, (c) a description of a healthy nutrition tool kit tailored to taquerias, and (d) an evaluation of the intervention at Year 3. It was found that traditional Mexican American—style menu offerings at taquerias tended to be healthier than American-style fast-food restaurant offerings. In addition, the initial response to the intervention has shown positive changes, which include the taqueria owners promoting available healthy menu items and modifying other menu offerings to reduce fats and increase fruit and vegetable availability. This, in turn, has led to a transition of the owners' perceptions of themselves as gatekeepers for a healthy community.
Effect of Treadmill Training on Autonomic Dysreflexia in Spinal Cord—Injured Rats
Authors: Laird Angela S. , Carrive Pascal , Waite Phil M. E.
Published: May 2009

Background. Weight-supported treadmill training is an emerging rehabilitation method used to improve locomotor ability in patients with spinal cord injury (SCI). However, little research has been undertaken to test the effect of such training on other consequences of SCI, such as neuropathic pain and autonomic dysfunction. Objective. This study investigates the effects of chronic treadmill training on the development of autonomic dysreflexia (AD), a form of cardiovascular dysfunction common in patients with cervical or high thoracic injury. Methods. Treadmill training commenced in adult male rats (n = 11) 3 days following complete T4 transection, whereas a sedentary SCI group (n = 9) and an intact group (n = 6) had no intervention. Treadmill training (up to 0.4 m/s) lasted for 10 min/d 5 days a week, for 6 weeks. Weekly measurements of locomotor ability (BBB scale), baseline mean arterial pressure, and heart rate were made, as were cardiovascular responses to training and colorectal distension (to trigger AD). Results. Treadmill training improved BBB scores from 2 weeks post-transection onward ( P = .010). However, it increased AD, resulting in augmented pressor responses from 2 to 6 weeks post-transection ( P = .029). Comparison of the vascular response to phenylephrine under ganglionic blockade showed an enhanced vasoconstrictor response in the renal vasculature of trained SCI animals. Immunohistochemical comparison of the L1—L6 spinal cord segments showed an increased area of CGRP immunoreactivity in the dorsal horn (lamina III/IV) of treadmill-trained SCI compared with intact and sedentary SCI animals. Conclusions. These results suggest that treadmill training exaggerated AD responses perhaps through a combination of enhanced vascular reactivity and central plasticity.
The mitochondrial genome structure of Xenoturbella bocki(phylum Xenoturbellida) is ancestral within the deuterostomes
Authors: Bourlat Sarah J , Rota-Stabelli Omar , Lanfear Robert , Telford Maximilian J
Published: May 2009

Background

Mitochondrial genome comparisons contribute in multiple ways when inferring animal relationships. As well as primary sequence data, rare genomic changes such as gene order, shared gene boundaries and genetic code changes, which are unlikely to have arisen through convergent evolution, are useful tools in resolving deep phylogenies.Xenoturbella bockiis a morphologically simple benthic marine worm recently found to belong among the deuterostomes. Here we present analyses comparing theXenoturbella bockimitochondrial gene order, genetic code and control region to those of other metazoan groups.

Results

The complete mitochondrial genome sequence ofXenoturbella bockiwas determined. The gene order is most similar to that of the chordates and the hemichordates, indicating that this conserved mitochondrial gene order might be ancestral to the deuterostome clade. Using data from all phyla of deuterostomes, we infer the ancestral mitochondrial gene order for this clade. Using inversion and breakpoint analyses of metazoan mitochondrial genomes, we test conflicting hypotheses for the phylogenetic placement ofXenoturbellaand find a closer affinity to the hemichordates than to other metazoan groups. Comparative analyses of the control region reveal similarities in the transcription initiation and termination sites and origin of replication ofXenoturbellawith those of the vertebrates. Phylogenetic analyses of the mitochondrial sequence indicate a weakly supported placement as a basal deuterostome, a result that may be the effect of compositional bias.

Conclusion

The mitochondrial genome ofXenoturbella bockihas a very conserved gene arrangement in the deuterostome group, strikingly similar to that of the hemichordates and the chordates, and thus to the ancestral deuterostome gene order. Similarity to the hemichordates in particular is suggested by inversion and breakpoint analysis. Finally, while phylogenetic analyses of the mitochondrial sequences support a basal deuterostome placement, support for this decreases with the use of more sophisticated models of sequence evolution.
Activation of p53-regulated pro-apoptotic signaling pathways in PrP-mediated myopathy
Authors: Liang Jingjing , Parchaliuk Debra , Medina Sarah , Sorensen Garrett , Landry Laura , Huang Shenghai , Wang Meiling , Kong Qingzhong , Booth Stephanie A
Published: May 2009

Background

We have reported that doxycycline-induced over-expression of wild type prion protein (PrP) in skeletal muscles of Tg(HQK) mice is sufficient to cause a primary myopathy with no signs of peripheral neuropathy. The preferential accumulation of the truncated PrP C1 fragment was closely correlated with these myopathic changes. In this study we use gene expression profiling to explore the temporal program of molecular changes underlying the PrP-mediated myopathy.

Results

We used DNA microarrays, and confirmatory real-time PCR and Western blot analysis to demonstrate deregulation of a large number of genes in the course of the progressive myopathy in the skeletal muscles of doxycycline-treated Tg(HQK) mice. These include the down-regulation of genes coding for the myofibrillar proteins and transcription factor MEF2c, and up-regulation of genes for lysosomal proteins that is concomitant with increased lysosomal activity in the skeletal muscles. Significantly, there was prominent up-regulation of p53 and p53-regulated genes involved in cell cycle arrest and promotion of apoptosis that paralleled the initiation and progression of the muscle pathology.

Conclusion

The data provides the firstin vivoevidence that directly links p53 to a wild type PrP-mediated disease. It is evident that several mechanistic features contribute to the myopathy observed in PrP over-expressing mice and that p53-related apoptotic pathways appear to play a major role.
Gene organization and sequence analyses of transfer RNA genes in Trypanosomatid parasites
Authors: Padilla-Mejía Norma E , Florencio-Martínez Luis E , Figueroa-Angulo Elisa E , Manning-Cela Rebeca G , Hernández-Rivas Rosaura , Myler Peter J , Martínez-Calvillo Santiago
Published: May 2009

Background

The protozoan pathogens Leishmania major, Trypanosoma brucei and Trypanosoma cruzi (the Tritryps) are parasites that produce devastating human diseases. These organisms show very unusual mechanisms of gene expression, such as polycistronic transcription. We are interested in the study of tRNA genes, which are transcribed by RNA polymerase III (Pol III). To analyze the sequences and genomic organization of tRNA genes and other Pol III-transcribed genes, we have performed an in silico analysis of the Tritryps genome sequences.

Results

Our analysis indicated the presence of 83, 66 and 120 genes in L. major, T. brucei and T. cruzi, respectively. These numbers include several previously unannotated selenocysteine (Sec) tRNA genes. Most tRNA genes are organized into clusters of 2 to 10 genes that may contain other Pol III-transcribed genes. The distribution of genes in the L. major genome does not seem to be totally random, like in most organisms. While the majority of the tRNA clusters do not show synteny (conservation of gene order) between the Tritryps, a cluster of 13 Pol III genes that is highly syntenic was identified. We have determined consensus sequences for the putative promoter regions (Boxes A and B) of the Tritryps tRNA genes, and specific changes were found in tRNA-Sec genes. Analysis of transcription termination signals of the tRNAs (clusters of Ts) showed differences between T. cruzi and the other two species. We have also identified several tRNA isodecoder genes (having the same anticodon, but different sequences elsewhere in the tRNA body) in the Tritryps.

Conclusion

A low number of tRNA genes is present in Tritryps. The overall weak synteny that they show indicates a reduced importance of genome location of Pol III genes compared to protein-coding genes. The fact that some of the differences between isodecoder genes occur in the internal promoter elements suggests that differential control of the expression of some isoacceptor tRNA genes in Tritryps is possible. The special characteristics found in Boxes A and B from tRNA-Sec genes from Tritryps indicate that the mechanisms that regulate their transcription might be different from those of other tRNA genes.
Generation of Phaseolus vulgaris ESTs and investigation of their regulation upon Uromyces appendiculatus infection
Authors: Thibivilliers Sandra , Joshi Trupti , Campbell Kimberly B , Scheffler Brian , Xu Dong , Cooper Bret , Nguyen Henry T , Stacey Gary
Published: May 2009

Background

Phaseolus vulgaris (common bean) is the second most important legume crop in the world after soybean. Consequently, yield losses due to fungal infection, like Uromyces appendiculatus (bean rust), have strong consequences. Several resistant genes were identified that confer resistance to bean rust infection. However, the downstream genes and mechanisms involved in bean resistance to infection are poorly characterized.

Results

A subtractive bean cDNA library composed of 10,581 unisequences was constructed and enriched in sequences regulated by either bean rust race 41, a virulent strain, or race 49, an avirulent strain on cultivar Early Gallatin carrying the resistance gene Ur-4. The construction of this library allowed the identification of 6,202 new bean ESTs, significantly adding to the available sequences for this plant. Regulation of selected bean genes in response to bean rust infection was confirmed by qRT-PCR. Plant gene expression was similar for both race 41 and 49 during the first 48 hours of the infection process but varied significantly at the later time points (72–96 hours after inoculation) mainly due to the presence of the Avr4 gene in the race 49 leading to a hypersensitive response in the bean plants. A biphasic pattern of gene expression was observed for several genes regulated in response to fungal infection.

Conclusion

The enrichment of the public database with over 6,000 bean ESTs significantly adds to the genomic resources available for this important crop plant. The analysis of these genes in response to bean rust infection provides a foundation for further studies of the mechanism of fungal disease resistance. The expression pattern of 90 bean genes upon rust infection shares several features with other legumes infected by biotrophic fungi. This finding suggests that the P. vulgaris-U. appendiculatus pathosystem could serve as a model to explore legume-rust interaction.
Comparison of the Glidescope® and Pentax AWS®laryngoscopes to the Macintosh laryngoscope for use by Advanced Paramedics in easy and simulated difficult intubation
Authors: Nasim Sajid , Maharaj Chrisen H , Malik Muhammad A , O' Donnell John , Higgins Brendan D , Laffey John G
Published: May 2009

Background

Intubation of the trachea in the pre-hospital setting may be lifesaving in severely ill and injured patients. However, tracheal intubation is frequently difficult to perform in this challenging environment, is associated with a lower success rate, and failed tracheal intubation constitutes an important cause of morbidity. Novel indirect laryngoscopes, such as the Glidescope® and the AWS® laryngoscopes may reduce this risk.

Methods

We compared the efficacy of these devices to the Macintosh laryngoscope when used by 25 Advanced Paramedics proficient in direct laryngoscopy, in a randomized, controlled, manikin study. Following brief didactic instruction with the Glidescope® and the AWS® laryngoscopes, each participant took turns performing laryngoscopy and intubation with each device, in an easy intubation scenario and following placement of a hard cervical collar, in a SimMan® manikin.

Results

Both the Glidescope® and the AWS® performed better than the Macintosh, and demonstrate considerable promise in this context. The AWS® had the least number of dental compressions in all three scenarios, and in the cervical spine immobilization scenario it required fewer maneuvers to optimize the view of the glottis.

Conclusion

The Glidescope® and AWS® devices possess advantages over the conventional Macintosh laryngoscope when used by Advanced Paramedics in normal and simulated difficult intubation scenarios in this manikin study. Further studies are required to extend these findings to the clinical setting.
Food allergy alters jejunal circular muscle contractility and induces local inflammatory cytokine expression in a mouse model
Authors: Valeur Jørgen , Lappalainen Jani , Rita Hannu , Lin Aung Htun , Kovanen Petri T , Berstad Arnold , Eklund Kari K , Vaali Kirsi
Published: May 2009

Background

We hypothesized that food allergy causes a state of non-specific jejunal dysmotility. This was tested in a mouse model.

Methods

Balb/c mice were epicutaneously sensitized with ovalbumin and challenged with 10 intragastric ovalbumin administrations every second day. Smooth muscle contractility of isolated circular jejunal sections was studied in organ bath with increasing concentrations of carbamylcholine chloride (carbachol). Smooth muscle layer thickness and mast cell protease-1 (MMCP-1) positive cell density were assayed histologically. Serum MMCP-1 and immunoglobulins were quantified by ELISA, and mRNA expressions of IFN-γ, IL-4, IL-6 and TGFβ-1 from jejunal and ileal tissue segments were analyzed with quantitative real-time PCR.

Results

Ovalbumin-specific serum IgE correlated with jejunal MMCP-1+ cell density. In the allergic mice, higher concentrations of carbachol were required to reach submaximal muscular stimulation, particularly in preparations derived from mice with diarrhoea. Decreased sensitivity to carbachol was associated with increased expression of IL-4 and IL-6 mRNA in jejunum. Smooth muscle layer thickness, as well as mRNA of IFN-γ and TGF-β1 remained unchanged.

Conclusion

In this mouse model of food allergy, we demonstrated a decreased response to a muscarinic agonist, and increased levels of proinflammatory IL-6 and Th2-related IL-4, but not Th1-related IFN-γ mRNAs in jejunum. IgE levels in serum correlated with the number of jejunal MMCP-1+ cells, and predicted diarrhoea. Overall, these changes may reflect a protective mechanism of the gut in food allergy.
High-resolution DNA copy number and gene expression analyses distinguish chromophobe renal cell carcinomas and renal oncocytomas
Authors: Yusenko Maria V , Kuiper Roland P , Boethe Tamas , Ljungberg Börje , van Kessel Ad Geurts , Kovacs Gyula
Published: May 2009

Background

The diagnosis of benign renal oncocytomas (RO) and chromophobe renal cell carcinomas (RCC) based on their morphology remains uncertain in several cases.

Methods

We have applied Affymetrix GeneChip Mapping 250 K NspI high-density oligoarrays to identify small genomic alterations, which may occur beyond the specific losses of entire chromosomes, and also Affymetrix GeneChip HG-U133 Plus2.0 oligoarrays for gene expression profiling.

Results

By analysing of DNA extracted from 30 chRCCs and 42 ROs, we have confirmed the high specificity of monosomies of chromosomes 1, 2, 6, 10, 13, 17 and 21 in 70–93% of the chRCCs, while ROs displayed loss of chromosome 1 and 14 in 24% and 5% of the cases, respectively. We demonstrated that chromosomal gene expression biases might correlate with chromosomal abnormalities found in chromophobe RCCs and ROs. The vast majority genes downregulated in chromophobe RCC were mapped to chromosomes 2, 6, 10, 13 and 17. However, most of the genes overexpressed in chromophobe RCCs were located to chromosomes without any copy number changes indicating a transcriptional regulation as a main event.

Conclusion

The SNP-array analysis failed to detect recurrent small deletions, which may mark loci of genes involved in the tumor development. However, we have identified loss of chromosome 2, 10, 13, 17 and 21 as discriminating alteration between chromophobe RCCs and ROs. Therefore, detection of these chromosomal changes can be used for the accurate diagnosis in routine histology.
A typhoid fever outbreak in a slum of South Dumdum municipality, West Bengal, India, 2007: Evidence for foodborne and waterborne transmission
Authors: Bhunia Rama , Hutin Yvan , Ramakrishnan Ramachandran , Pal Nishith , Sen Tapas , Murhekar Manoj
Published: May 2009

Background

In April 2007, a slum of South Dumdum municipality, West Bengal reported an increase in fever cases. We investigated to identify the agent, the source and to propose recommendations.

Methods

We defined a suspected case of typhoid fever as occurrence of fever for ≥ one week among residents of ward 1 of South Dumdum during February – May 2007. We searched for suspected cases in health care facilities and collected blood specimens. We described the outbreak by time, place and person. We compared probable cases (Widal positive >= 1:80) with neighbourhood-matched controls. We assessed the environment and collected water specimens.

Results

We identified 103 suspected cases (Attack rate: 74/10,000, highest among 5–14 years old group, no deaths). Salmonella (enterica) Typhi was isolated from one of four blood specimens and 65 of 103 sera were >= 1:80 Widal positive. The outbreak started on 13 February, peaked twice during the last week of March and second week of April and lasted till 27 April. Suspected cases clustered around three public taps. Among 65 probable cases and 65 controls, eating milk products from a sweet shop (Matched odds ratio [MOR]: 6.2, 95% confidence interval [CI]: 2.4–16, population attributable fraction [PAF]: 53%) and drinking piped water (MOR: 7.3, 95% CI: 2.5–21, PAF-52%) were associated with illness. The sweet shop food handler suffered from typhoid in January. The pipelines of intermittent non-chlorinated water supply ran next to an open drain connected with sewerage system and water specimens showed faecal contamination.

Conclusion

The investigation suggested that an initial foodborne outbreak of typhoid led to the contamination of the water supply resulting in a secondary, waterborne wave. We educated the food handler, repaired the pipelines and ensured chlorination of the water.
Improving protein structure similarity searches using domain boundaries based on conserved sequence information
Authors: Thompson Kenneth Evan , Wang Yanli , Madej Tom , Bryant Stephen H
Published: May 2009

Background

The identification of protein domains plays an important role in protein structure comparison. Domain query size and composition are critical to structure similarity search algorithms such as the Vector Alignment Search Tool (VAST), the method employed for computing related protein structures in NCBI Entrez system. Currently, domains identified on the basis of structural compactness are used for VAST computations. In this study, we have investigated how alternative definitions of domains derived from conserved sequence alignments in the Conserved Domain Database (CDD) would affect the domain comparisons and structure similarity search performance of VAST.

Results

Alternative domains, which have significantly different secondary structure composition from those based on structurally compact units, were identified based on the alignment footprints of curated protein sequence domain families. Our analysis indicates that domain boundaries disagree on roughly 8% of protein chains in the medium redundancy subset of the Molecular Modeling Database (MMDB). These conflicting sequence based domain boundaries perform slightly better than structure domains in structure similarity searches, and there are interesting cases when structure similarity search performance is markedly improved.

Conclusion

Structure similarity searches using domain boundaries based on conserved sequence information can provide an additional method for investigators to identify interesting similarities between proteins with known structures. Because of the improvement in performance of structure similarity searches using sequence domain boundaries, we are in the process of implementing their inclusion into the VAST search and MMDB resources in the NCBI Entrez system.
Validity and reliability of the Child Perceptions Questionnaires applied in Brazilian children
Authors: Barbosa Taís S , Tureli Maria Claudia M , Gavião Maria Beatriz D
Published: May 2009

Background

The Child Perceptions Questionnaires (CPQ8–10 and CPQ11–14) are indicators of child oral health-related quality of life. The aim of this study was to assess the validity and reliability of the self-applied CPQ8–10 and CPQ11–14 in Brazilian children, after translations and cultural adaptations in the Brazilian Portuguese language.

Methods

Schoolchildren were recruited from general populations for pre-testing (n = 80), validity (n = 210), and test-retest reliability (n = 50) studies. They were also examined for dental caries, gingivitis, fluorosis, and malocclusion.

Results

Children with greater dental caries experience in primary dentition had higher impacts on CPQ domains. Girls had higher scores for CPQ8–10 domains than boys. Mean CPQ11–14 scores were highest for 11-year-old children and lowest for 14-year-old children. Construct validity was supported by significant associations between the CPQ8–10 and CPQ11–14 scores and the global rating of oral health (r = 0.38, r = 0.43) and overall well-being (r = 0.39, r = 0.60), respectively. The Cronbach's alpha was 0.95 for both questionnaires. The test-retest reliabilities of the overall CPQ8–10 and CPQ11–14 scores were both excellent (ICC = 0.96, ICC = 0.92).

Conclusion

The Brazilian Portuguese version of CPQ8–10 and CPQ11–14 was valuable and reliable for use in the Brazilian child population, although discriminant validity was sporadic due to the fact that impacts are mediated by others factors, such personal, social, and environmental variables.
Studies on the antimicrobial activity and brine shrimp toxicity of Zeyheria tuberculosa (Vell.) Bur. (Bignoniaceae) extracts and their main constituents
Authors: Bastos Maria Lysete A , Lima Maria Raquel F , Conserva Lucia M , Andrade Vânia S , Rocha Eliana MM , Lemos Rosangela PL
Published: May 2009

Background

Due to the indiscriminate use of antimicrobial drugs, the emergence of human pathogenic microorganisms resistant to major classes of antibiotics has been increased and has caused many clinical problems in the treatment of infectious diseases. Thus, the aim of this study was to evaluate for the first time the in vitro antimicrobial activity and brine shrimp lethality of extracts and isolated compounds from Zeyheria tuberculosa (Vell.) Bur., a species used in Brazilian folk medicine for treatment of cancer and skin diseases.

Methods

Using the disc diffusion method, bioautography assay and brine shrimp toxicity test (Artemia salina Leach), we studied the antimicrobial activity and lethality of extracts and isolated compounds against three microorganisms strains, including Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa) bacteria and yeasts (Candida albicans).

Results

In this study, the extracts inhibited S. aureus (8.0 ± 0.0 to 14.0 ± 0.0 mm) and C. albicans (15.3 ± 0.68 to 25.6 ± 0.4 mm) growth. In the brine shrimp test, only two of them showed toxic effects (LC50 29.55 to 398.05 μg/mL) and some extracts were non-toxic or showed weak lethality (LC50 705.02 to > 1000 μg/mL). From these extracts, four flavones [5,6,7,8-tetramethoxyflavone (1), 5,6,7-trimethoxyflavone (2), 4'-hydroxy-5,6,7,8-tetramethoxyflavone (3), and 4'-hydroxy-5,6,7-trimethoxyflavone (4)] were isolated through bioassay-guided fractionation and identified based on the 1D and 2D NMR spectral data. By bioautography assays, compounds 1 [S. aureus (16.0 ± 0.0 mm) and C. albicans (20.0 ± 0.0 mm)] and 3 [S. aureus (10.3 ± 0.6 mm) and C. albicans (19.7 ± 0.6 mm)] inhibited both microorganisms while 2 inhibited only S. aureus (11.7 ± 0.6 mm). Compound 4 did not restrain the growth of any tested microorganism.

Conclusion

Our results showed that extracts and isolated flavones from Z. tuberculosa may be particularly useful against two pathogenic microorganisms, S. aureus and C. albicans. These results may justify the popular use this species since some fractions tested had antimicrobial activity and others showed significant toxic effects on brine shrimps. However, in order to evaluate possible clinical application in therapy of infectious diseases, further studies about the safety and toxicity of isolated compounds are needed.
Identifying candidate sites for crop biofortification in Latin America: case studies in Colombia, Nicaragua and Bolivia
Authors: Zapata-Caldas Emmanuel , Hyman Glenn , Pachón Helena , Monserrate Fredy Alexander , Varela Liliana Vesga
Published: May 2009

Background

Agricultural science can address a population's vitamin, amino acid and mineral malnutrition through biofortification - agronomy, plant breeding and biotechnology to develop crops with high nutrient contents. Biofortified crop varieties should be grown in areas with populations at risk of nutrient deficiency and in areas where the same crop is already grown and consumed. Information on the population at risk of nutrient deficiency is rarely available for sub-national administrative units, such as provinces, districts, and municipalities. Nor is this type of information commonly analyzed with data on agricultural production. This project developed a method to identify populations at risk of nutrient deficiency in zones with high crop production, places where biofortification interventions could be targeted.

Results

Nutrient deficiency risk data were combined with crop production and socioeconomic data to assess the suitability of establishing an intervention. Our analysis developed maps of candidate sites for biofortification interventions for nine countries in Latin America and the Caribbean. Results for Colombia, Nicaragua, and Bolivia are presented in this paper. Interventions in northern Colombia appear promising for all crops, while sites for bean biofortification are widely scattered throughout the country. The most promising sites in Nicaragua are found in the center-north region. Candidate sites for biofortification in Bolivia are found in the central part of the country, in the Andes Mountains. The availability and resolution of data limits the analysis. Some areas show opportunities for biofortification of several crops, taking advantage of their spatial coincidence. Results from this analysis should be confirmed by experts or through field visits.

Conclusion

This study demonstrates a method for identifying candidate sites for biofortification interventions. The method evaluates populations at risk of nutrient deficiencies for sub-national administrative regions, and provides a reasonable alternative to more costly, information-intensive approaches.
Src, PKCα, and PKCδ are required for αvβ3 integrin-mediated metastatic melanoma invasion
Authors: Putnam Andrew J , Schulz Veronique V , Freiter Eric M , Bill Heather M , Miranti Cindy K
Published: May 2009

Background

Integrins, cell-surface receptors that mediate adhesive interactions between cells and the extracellular matrix (ECM), play an important role in cancer progression. Expression of the vitronectin receptor αvβ3 integrin correlates with increased invasive and metastatic capacity of malignant melanomas, yet it remains unclear how expression of this integrin triggers melanoma invasion and metastasis.

Results

Two melanoma cell lines C8161.9 and M14 both express high levels of αvβ3 integrin and adhere to vitronectin. However, only the highly metastatic C8161.9 cells are capable of invading vitronectin-enriched Matrigel in an αvβ3-depenent manner. Elevated levels of PKCα and PKCδ, and activated Src were detected specifically in the highly metastatic melanoma cells, but not in the low metastatic M14 cells. Inhibition of Src or PKC activity suppressed αvβ3-dependent invasion. Furthermore, over expression of Src or PKCα and PKCδ was sufficient to confer αvβ3-dependent invasiveness to M14 cells. Stress fiber formation and focal adhesion formation were almost completely absent in C8161.9 cells compared to M14 cells. Inhibition of Src signaling was sufficient to restore normal actin architecture, and resulted in decreased p190RhoGAP phosphorylation and enhanced RhoA activity. Src had no effect on Rac activity. Loss of PKCα expression, but not PKCδ, by siRNA inhibited Rac and PAK activity as well as invasiveness. Loss of PKCα restored focal adhesion formation and partially restored stress fiber formation, while loss of PKCδ primarily restored stress fibers.

Conclusion

The misregulated expression of PKCα and PKCδ and elevated Src activity in metastatic melanoma cells is required for efficient αvβ3-mediated invasion. PKCα and Src enhance αvβ3-mediated invasion in part by increasing the GTPase activity of Rac relative to RhoA. PKCα influences focal adhesion formation, while PKCδ controls stress fibers.