bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Moderate Vasoconstriction on the Wave Reflection Properties of the Pulmonary Arterial Bed
Authors: Piene Hroar , Hauge Anton
Published: February 2011

Increased transmural pressure in the pulmonary arterial bed may reduce vascular input impedance and reduce hydraulic power linked to pulsatile blood flow. Vascular impedance and pulsatile hydraulic power (Wp) levels of isolated perfused rabbit lungs were compared after similar rises of pulmonary arterial pressure (PAp), induced either by vasoconstriction or by left atrial pressure (LAp) elevation. Resulting Wp levels were significantly smaller after vasoconstriction than LAp elevation. Wp showed a minimum level at physiologic PAp (about 20 cm H2O) irrespective of the cause of PAp elevation. Pressure pulse wave reflection coefficient (Γ) was calculated for control and test situations, and was found to be approximately doubled after vasoconstriction. Only minor changes in Γ were found after LAP elevation. Accordingly, moderate vasoconstriction (resulting PAp≅20 cm H2O) caused a backward traveling pressure wave of high amplitude, appearing in counter‐phase to the forward pressure wave at the input site. The total pressure wave amplitude was thereby markedly lowered, resulting in a reduced Wp level. We assume that this effect of moderate vasoconstriction may be one reason for the existence of vascular smooth muscles in the pulmonary arteries.
The Influence of Pulmonary Blood Flow Rate on Vascular Input Impedance and Hydraulic Power in the Sympathetically and Noradrenaline Stimulated Cat Lung
Authors: Piene Hroar
Published: February 2011

This study was designed to evaluate the influence of sympathetic nerve stimulation (NS) and α‐adrenergic receptor stimulation (αS) on the pulmonary vascular input impedance and hydraulic power output of the right heart during variations of cardiac output (CO). An open chest cat preparation was used and pulsatile pressure and flow in the pulmonary artery were measured by high frequency response transducers. Calculations showed that vascular resistance (VR) was inversely dependent on CO, hut input impedance of the unstimulated lung was not influenced by CO variations. NS or αS increased VR and input impedance significantly, and the relation pulsatile hydraulic power/total hydraulic power (Wp/Wt) increased 40%, indicating that such stimulation has larger relative influence on impedance than on resistance. The reduction of arterial compliance during NS (maximal stimulus) was calculated to be 60%, independent of CO. Input impedance during NS or αS was reduced by CO elevations, probably because the concomitant distension of the arterial bed reduced arterial resistance and inertance. The ratio Wp/CO, which expresses the fraction of pulsatile hydraulic power lost per ml mean arterial flow, was found to be flow dependent both in control and stimulated conditions: Wp/CO was positively correlated to CO in control condition and weakly negatively correlated to CO during stimulation. At high CO the arterial vessels could he stimulated and stiffened without much extra load on the right heart.
Waiting to Exhale: Chaos, Toxicity and the Origins of the U.S. Chemical Warfare Service
Authors: Ede Andrew
Published: February 2011

In 2008, Susan L. Smith published “Mustard Gas and American Race-Based Human Experimentation in World War II.” Research, undertaken by the US Army, attempted to quantify the effect of mustard gas (actually a volitile liquid) and othe chemical agents on people from different racial groups. This was based on the idea that different races would respond differently to the toxins, and in particular that this would be evident through dermal reaction. In other words, different skin color might mean different skin constitution. Some of the testing seemed reasonable, since new chemicals and equipment had been developed since 1919, and the racial issue added another dimension to the research. On closer examination, the testing was primarily based on old chemical agents such as mustard gas, Lewisite and phosgene, and thus the extent of the testing seemed scientifically and medically unnecessary. The chemical agents had been developed, tested, used in battle, the wounded treated and the dead subjected to detailed pathological study. The major combatants in World War I had all committed extensive scientific resources to the study of these agents looking at both offensive and defensive aspects of their use, including toxicity testing. The U.S. Chemical Warfare Service (CWS) had been formed in 1918 to specifically deal with issues such as toxicity tests, so why was the U.S. Army revisiting the subject of chemical weapons testing during World War II?
Veterans’ Welfare, the GI Bill and American Demobilization
Authors: McEnaney Laura
Published: February 2011

The passage of the Servicemen’s Readjustment Act of 1944 — or GI Bill — opened up a dialogue about men’s physical and mental health, for it addressed very directly what ordinary men would need to recover from extraordinary violence. Political leaders identified veterans’ “welfare,” by which they meant general well-being, as a top priority of World War II’s recovery, and the GI Bill was the centerpiece of their agenda. The bill’s passage was an impressive legislative triumph, the collective product of massive medical, legal, and social science research, bipartisan politicking, and veterans’ activism. It provided education, housing, and small business assistance, along with mental and physical rehabilitation in government-funded hospitals. All of these programs, whether they served mind, body, or wallet, amounted to welfare — a set of government-sponsored policies and services designed to aid a soldier’s transition from enlisted man to healthy, productive citizen. Thus we have to think about the broad reach of the GI Bill’s welfare provision as one of the health legacies of World War II.
The science and regulations of probiotic food and supplement product labeling
Authors: Sanders Mary Ellen , Levy Dan D.
Published: February 2011

Presented by the New York Academy of Sciences, the U.S. Food and Drug Administration (FDA), and the U.S. Office of Dietary Supplements of the National Institutes of Health, the symposium “Probiotic Foods and Supplements: The Science and Regulations of Labeling,” was held on June 12, 2010 at the New York Academy of Sciences, New York, NY, the goals of which were to facilitate the exchange of ideas regarding labeling and substantiation of claims for probiotics among academic, industry, and regulatory professionals, and to discuss ways to translate and communicate research results in a truthful way to the consumer and to such health professionals as physicians, pharmacists, and dieticians. The target audience for this symposium included academicians interested in conducting research on the health benefits of probiotics; scientists; communications personnel, and regulatory specialists from companies involved in, or interested in, the marketing of probiotics; U.S. government regulatory experts tasked with oversight of probiotic foods and dietary supplement products; and other experts in the field interested in the development of probiotics for the U.S. market.
Single nucleotide polymorphisms across a species’ range: implications for conservation studies of Pacific salmon
Authors: SEEB L. W. , TEMPLIN W. D. , SATO S. , ABE S. , WARHEIT K. , PARK J. Y. , SEEB J. E.
Published: February 2011

Studies of the oceanic and near‐shore distributions of Pacific salmon, whose migrations typically span thousands of kilometres, have become increasingly valuable in the presence of climate change, increasing hatchery production and potentially high rates of bycatch in offshore fisheries. Genetics data offer considerable insights into both the migratory routes as well as the evolutionary histories of the species. However, these types of studies require extensive data sets from spawning populations originating from across the species’ range. Single nucleotide polymorphisms (SNPs) have been particularly amenable for multinational applications because they are easily shared, require little interlaboratory standardization and can be assayed through increasingly efficient technologies. Here, we discuss the development of a data set for 114 populations of chum salmon through a collaboration among North American and Asian researchers, termed PacSNP. PacSNP is focused on developing the database and applying it to problems of international interest. A data set spanning the entire range of species provides a unique opportunity to examine patterns of variability, and we review issues associated with SNP development. We found evidence of ascertainment bias within the data set, variable linkage relationships between SNPs associated with ancestral groupings and outlier loci with alleles associated with latitude.
Outcomes of pseudophakic retinal detachment
Authors: Tuft Stephen J. , Gore Daniel M. , Bunce Catey , Sullivan Paul M. , Minassian Darwin C.
Published: February 2011

Purpose:  To provide data on the outcome of pseudophakic retinal detachment (PRD).

Methods:  In a retrospective case–control study, we identified a consecutive series of 63 298 cataract extractions (45 520 patients) performed in a single institution between 1994 and 2003. We included 249 cases with PRD and 845 controls that had cataract surgery on the same day as cases but without PRD. Outcome measures were the risk of impaired vision (6/18–6/60) or blindness (<6/60). A multinomial logistic regression model evaluated risk factors for impaired vision or blindness, while multivariable regression models measured the relative risk of poor visual outcome for posterior capsule tear (PCT) and PRD.

Results:  Primary pars plana vitrectomy was performed on 207 (84.5%) of the 245 cases treated with surgery, of which 175 (71.4%) needed one procedure. The final acuity was <6/60 in 62 cases (24.9%) and 34 controls (4.0%). After PRD, the relative risk for a final visual outcome <6/60 was 6.8 [95% confidence interval (CI) 4.3–10.6; p < 0.001], and we estimated that the proportion of blindness attributable to PRD was 1.1% (CI 0.7–1.9%). A PCT prior to a PRD was not associated with an increased risk of macular detachment (p = 0.165), but it did carry an increased risk of blindness [odds ratio 4.8 (CI 2.2–10.2; p < 0.001].

Conclusion:  Although a PCT has an adverse effect on visual outcome after cataract surgery, a PRD is the foremost surgery‐related risk for a poor visual outcome. Patient education of symptoms and prompt treatment may limit the visual consequences.
Amelioration of Amyloid β‐Induced Cognitive Deficits by Zataria multiflora Boiss. Essential Oil in a Rat Model of Alzheimer's Disease
Authors: Majlessi Nahid , Choopani Samira , Kamalinejad Mohammad , Azizi Zahra
Published: February 2011

Introduction: The limitations of current Alzheimer's disease (AD) therapeutics have prompted investigation into innovative therapeutics focused on antiinflammatory, antioxidant, and neuroprotective agents including those from medicinal plants. Numerous plants have been tested for their potential for alleviating symptoms of AD. Aims:Zataria multiflora Boiss. (ZM) a member of Lamiaceae family has been used in Iranian traditional medicine for its beneficial effects on mental abilities. Therefore, the effect of its essential oil was evaluated in a rat model of AD. Methods: Amyloid β‐protein (Aβ) fragment 25–35 was injected bilaterally in the CA1 region of rats hippocampus and the effect of different doses of ZM essential oil (50, 100, or 200 μL/kg) on cognitive function was investigated in the Morris water maze. Acute toxicity of the essential oil was also studied. Results: The results showed increases in escape latency, traveled distance, heading angle, and decreases in target quadrant entries in Aβ‐received groups as compared to the control group. This impairment was reversed by ZM essential oil. The results of acute toxicity testing revealed that the calculated LD50 (1264.9 μL/kg) is much higher than the therapeutic dose (100 μL/kg). Conclusions: It seems that antioxidant, antiinflammatory, and anticholinesterase activities of ZM or its main constituents might contribute to its beneficial effects in this model. Our findings suggest that ZM may be a potentially valuable source of natural therapeutic agents for the treatment of AD. However, further investigations are necessary to establish its clinical efficacy and potential toxicity, before any recommendations concerning its use as a medication in the treatment of AD.
Screening of Therapeutic Strategies for Huntington's Disease in YAC128 Transgenic Mice
Authors: Gil‐Mohapel Joana M.
Published: February 2011

Huntington's disease (HD) is a hereditary neurodegenerative disorder caused by an unstable expansion of cytosine‐adenine‐guanine (CAG) repeats in the HD gene. The symptoms include cognitive dysfunction and severe motor impairment with loss of voluntary movement coordination that is later replaced by bradykinesia and rigidity. The neuropathology is characterized by neuronal loss mainly in the striatum and cortex, and the appearance of neuronal intranuclear inclusions of mutant huntingtin. The mechanisms responsible for neurodegeneration are still not fully understood although excitotoxicity and a consequent increase in intracellular calcium concentration as well as the activation of caspases and calapins are known to play a key role. There is currently no satisfactory treatment or cure for this disease. The YAC128 transgenic mice express the full‐length human HD gene with 128 CAG repeats and constitute a unique model for the study of HD as they replicate the slow and biphasic progression of behavioral deficits characteristic of the human condition and show striatal neuronal loss. As such, these transgenic mice have been an invaluable model not only for the elucidation of the neurodegenerative pathways in HD, but also for the screening and development of new therapeutic approaches. Here, I will review the unique characteristics of this transgenic HD model and will provide a summary of the therapies that have been tested in these mice, namely: potentiation of the protective roles of wild‐type huntingtin and mutant huntingtin aggregation, transglutaminase inhibition, inhibition of glutamate‐ and dopamine‐induced toxicity, apoptosis inhibition, use of essential fatty acids, and the novel approach of intrabody gene therapy. The insights obtained from these and future studies will help identify potential candidates for clinical trials and will ultimately contribute to the discovery of a successful treatment for this devastating neurodegenerative disorder.
Fuel Cell ASAP: Two Iterations of an Automated Stack Assembly Process and Ramifications for Fuel Cell Design-for-Manufacture Considerations
Authors: Laskowski Christina , Derby Stephen
Published: February 2011

Polymer-electrode membrane fuel cell technology, a low-emission power source receiving much attention for its efficiency, will need to progress from low-volume production to high-volume within the course of the next decade. To successfully achieve this transition, significant research progress has already been made toward developing a fully functional fuel cell automatic stack assembly robotic station. Lessons can be drawn from this research with regards to design-for-manufacture (DFM) and design-for-assembly (DFA) considerations of fuel cells; however, more work still remains to be done. This document outlines both iterations of the robotic fuel cell assembly stations, other work to date, DFM and DFA lessons learned, and the anticipated future progression of automatic fuel cell stack assembly stations. Two individual robotic fuel cell assembly stations were constructed, including custom-built end effectors and part feeders. The second station incorporated numerous improvements, including overlapping work envelopes, elimination of a shuttle cart, software synchronization, fewer axes, and a better end effector. Consequentially, the second workcell achieved a fourfold improvement in cycle time over the previous iteration. Future improvements will focus in part upon improving the reliability of the overall system. As the stack assembly workcell continues to improve, research will focus upon the ramifications and interplay of tolerances, stack failure modes, sealing, reliability, and the potential for component redesign specifically to optimize fuel cell manufacturing throughput.
Electrical and Thermal Performance of a Solid Oxide Fuel Cell Unit With Nonuniform Inlet Flow and High Fuel Utilization
Authors: Liu Syu-Fang , Chiang Mu-Sheng , Wang Shih-Bin , Yuan Ping
Published: February 2011

This study investigates the electrical performance of a planar solid oxide fuel cell unit with cross-flow configuration when the fuel utilization gets higher and the fuel inlet flows are nonuniform. A numerical code, solving the two-dimensional, simultaneous, partial differential equations of mass, energy, and electrochemistry and neglecting the stack direction variation effect, is developed. The results show that the fuel utilization increases with a decrease in the molar flow rate, and the average current density decreases when the molar flow rate drops. In addition, nonuniform pattern A induces more severe happening of nonreaction area in the corner of the fuel exit and the air inlet. This nonreaction area deteriorates the average current density and then reduces the electrical performance to 7%. This study suggests that the fuel inlet manifold should be located far from the inlet of air, which is able to decrease the deterioration to below 3% when using nonuniform profile of pattern B. On the other hand, employing a suitable air flow rate, we can easily control the operating temperature of a solid oxide fuel cell unit and the effect of nonuniform inlet air flow rate on the temperature distribution becomes negligible.
Describing Function Analysis of Limit Cycles in a Multiple Flame Combustor
Authors: Boudy Frédéric , Durox Daniel , Schuller Thierry , Jomaas Grunde , Candel Sébastien
Published: February 2011

A recently developed nonlinear flame describing function (FDF) is used to analyze combustion instabilities in a system where the feeding manifold has a variable size and where the flame is confined by quartz tubes of variable length. Self-sustained combustion oscillations are observed when the geometry is changed. The regimes of oscillation are characterized at the limit cycle and also during the onset of oscillations. The theoretical predictions of the oscillation frequencies and levels are obtained using the FDF. This generalizes the concept of flame transfer function by including dependence on the frequency and level of oscillation. Predictions are compared with experimental results for two different lengths of the confinement tube. These results are, in turn, used to predict most of the experimentally observed phenomena and in particular, the correct oscillation levels and frequencies at limit cycles.
An Investigation of Air-Cooled Steam Condenser Performance Under Windy Conditions Using Computational Fluid Dynamics
Authors: Owen M. T. F. , Kröger D. G.
Published: February 2011

The development of an efficient and reliable method of evaluating the performance of an air-cooled steam condenser (ACC) under windy conditions using computational fluid dynamics (CFD) is presented. A two-step modeling approach is employed as a result of computational limitations. The numerical ACC model developed in this study makes use of the pressure jump fan model, among other approximations, in an attempt to minimize the computational expense of the performance evaluation. The accuracy of the numerical model is verified through a comparison of the numerical results to test data collected during full-scale tests carried out on an operational ACC. Good correlation is achieved between the numerical results and test data. The effect of wind on ACC performance at El Dorado Power Plant (Nevada, USA) is investigated. It is found that reduced fan performance due to distorted flow at the inlet of the upstream fans is the primary contributor to the reduction in ACC performance associated with increased wind speed in this case. The model developed in this study has the potential to allow for the evaluation of large ACC installations and provides a reliable platform from which further investigations into improving ACC performance under windy conditions can be carried out.
Methane Oxycombustion for Low CO2 Cycles: Blowoff Measurements and Analysis
Authors: Amato A. , Hudak B. , D’Carlo P. , Noble D. , Scarborough D. , Seitzman J. , Lieuwen T.
Published: February 2011

Increasing concerns about climate change have encouraged interest in zero-CO2 emission hydrocarbon combustion techniques. In one approach, nitrogen is removed from the combustion air and replaced with another diluent, typically carbon dioxide or steam. In this way, formation of nitrogen oxides is prevented and the exhaust stream can be separated into concentrated CO2 and water by a simple condensation process. The concentrated CO2 stream can then be sequestered or used for enhanced oil recovery. Burning fuels in an O2/CO2 diluent raises new combustion opportunities and challenges for both emissions and operability: this study focuses on the latter aspect. CH4/O2/CO2 flames have slower chemical kinetics than methane-air flames and as such, flame stability is more problematic as they are easier to blow off. This issue was investigated experimentally by characterizing the stability boundaries of a swirl stabilized combustor. Near stoichiometric CO2 and N2 diluted methane/oxygen flames were considered and compared with lean methane/air flames. Numerical modeling of chemical kinetics was also performed to analyze the dependence of laminar flame speeds and extinction strain rates upon dilution by different species and to develop correlations for blowoff boundaries. Finally, blowoff trends at high pressure were extrapolated from atmospheric pressure data to simulate conditions closer to those of gas turbines.
Fluid Structure Interactions for Blast Wave Mitigation
Authors: Peng Wen , Zhang Zhaoyan , Gogos George , Gazonas George
Published: February 2011

The dynamic response of a free-standing plate subjected to a blast wave is studied numerically to investigate the effects of fluid-structure interaction (FSI) in blast wave mitigation. Previous work on the FSI between a blast wave and a free-standing plate (Kambouchev, N., et al., 2006, “Nonlinear Compressibility Effects in Fluid-Structure Interaction and Their Implications on the Air-Blast Loading of Structures,” J. Appl. Phys., 100(6), p. 063519) has assumed a constant atmospheric pressure at the back of the plate and neglected the resistance caused by the shock wave formation due to the receding motion of the plate. This paper develops an FSI model that includes the resistance caused by the shock wave formation at the back of the plate. The numerical results show that the resistance to the plate motion is especially pronounced for a light plate, and as a result, the previous work overpredicts the mitigation effects of FSI. Therefore, the effects of the interaction between the plate and the shock wave formation at the back of the plate should be considered in blast wave mitigation.
Instability of Flexible Strip Hanging Over Edge of Flat Frictional Surface
Authors: Plaut R. H. , Dillard D. A.
Published: February 2011

The conditions for an overhanging flexible strip to slide off a flat surface are investigated. This problem may be applicable to pieces of paper, fabric, leather, and other flexible materials, including plastic and metallic strips used herein for experimental comparisons. The critical overhang length depends on (a) the length, weight per unit length, and bending stiffness of the strip, (b) the coefficients of friction (CoFs) between the strip and both the surface and its edge, and (c) the inclination of the surface. The strip is modeled as an inextensible elastica. A shooting method is applied to solve the nonlinear equations that are based on equilibrium, geometry, and Coulomb friction. Three types of equilibrium shape are obtained. In the most common type, one end of the strip overhangs the edge and the other end contains a segment that is in contact with the surface. In another type, contact only occurs at the nonoverhanging end and at the edge. The third type involves the strip balancing on the edge of the surface. The ratio of the critical overhang length to the total strip length is plotted as a function of the surface CoF, edge CoF, and weight parameter for a horizontal surface. In most cases, this ratio increases as the CoFs and the strip’s bending stiffness increase, and decreases as the strip’s weight per unit length increases. The rotation of the strip at the edge tends to increase as the strip’s weight per unit length, the strip’s length, and the surface CoF increase, and to decrease as the strip’s bending stiffness increases. Inclined surfaces are also considered, and the critical overhang length decreases as the surface slopes more downward toward the edge. The theoretical results are compared with experimental data, and the agreement is good.
Solution of the Contact Zone Orientation for Normal Elliptical Hertzian Contact
Authors: Garland Philip P. , Rogers Robert J.
Published: February 2011

Many mechanical designs have parts that come into, or lose, contact with each other. When elastic bodies with second order surface geometries come into contact, the contact patch is expected to be approximately flat and to have an elliptical boundary. Classic Hertzian contact mechanics can be used to model such contacts, but since there is no closed-form analytical solution to predict the major and minor axes of the contact zone ellipse, approximate numerical methods have been developed, some of which are very accurate. Predictions of the mutual approach of the bodies and the contact pressure distribution can then be made. Although the shape of the contact ellipse has been modeled and solved for, to date there has been no solution for the orientation of the contact ellipse with respect to either of the contacting bodies. The contact ellipse orientation is needed in order to model the shear stress distributions that occur when sticking friction forces are developed and separate contact zones of sticking and slipping are expected. Using the results of a numerical solution for the conventional contact parameters, this paper presents an analytical solution of the orientation of the contact ellipse, which is shown to depend only on the curvatures and the relative orientation of the contacting bodies. In order to validate the analytical solution, the results are compared with those from ABAQUS™ finite element simulations for cases of identical bodies and bodies with dissimilar curvatures. The predictions of the contact ellipse orientation angles and the major and minor semi-axes agree very well for all cases considered.
UV-based nanoimprinting lithography with a fluorinated flexible stamp
Authors: Zhu Zhendong , Li Qunqing , Zhang Lihui , Chen Mo , Fan Shoushan
Published: February 2011

A custom-made copolymer of a perfluoropolyether (PFPE) and a hyperbranched polymer (HP) was employed to prepare an UV-based nanoimprinting lithographic (NIL) flexible HPFPE stamp. The properties of the HP afforded the resultant HPFPE resist with low viscosity, suitable surface energy, high Young’s modulus, and enhanced stability. The HPFPE resist also presented excellent properties of antisticking, and durability, no deformation, or distortion after long time usage; therefore, demonstrating an improvement in the NIL pattern transfer fidelity and resolution. By optimizing the UV-based NIL process with this flexible HPFPE stamp, the imprinting results showed near zero residues at the bottom of the resist grooves, and no sticking over a large area. The structure of the HPFPE flexible stamp was transferred intact onto a soft substrate indium tin oxide/polyethylene terephthalate film with good resolution, achieving a 50 nm linewidth and a 200 nm period.
Simple PowerPoint Animation
Authors: Takahashi Leo
Published: February 2011

The use of animation as a teaching tool has long been of interest to the readers of and contributors to this journal.1–5 While the sophisticated techniques presented in the cited papers are excellent and useful, there is one overlooked technique that may be of interest to the teacher who wants something quick and simple to enhance classroom presentations: PowerPoint animation.
MUC1-C Oncoprotein Promotes STAT3 Activation in an Autoinductive Regulatory Loop
Authors: Ahmad Rehan , Rajabi Hasan , Kosugi Michio , Joshi Maya Datt , Alam Maroof , Vasir Baldev , Kawano Takeshi , Kharbanda Surender , Kufe Donald
Published: February 2011

An inflammatory response of epithelial cells may be co-opted to promote cancer cell survival.
The Potential Cost of High-Throughput Proteomics
Authors: White Forest M.
Published: February 2011

The production of false leads by automated curation of high-throughput proteomic data sets exerts a toll on biological research and advancement.
Visual Representation of Scientific InformationA presentation from the Broad Institute Scientific Retreat at the Harvard Medical School, Boston, Massachusetts, 7 November 2010.
Authors: Wong Bang
Published: February 2011

Judicious choice of graphical representations can improve visual communication.
Double-Trouble Mutation
Authors: Kiberstis Paula A.
Published: February 2011

Potassium channel mutations drive both cell growth and hormone production in an adrenal tumor that causes severe hypertension.
Stem Cell Therapy Works (in Mice Models of Emphysema)!
Authors: Ahmad Shama
Published: February 2011

Autologous adipose-derived stem cells attenuate both pulmonary and extrapulmonary effects of cigarette smoke exposure.
Growth Factor Makes Memories Stick
Authors: Buettner Christoph
Published: February 2011

Insulin-like growth factor II forestalls forgetting by boosting long-term potentiation and memory retention.
Reversible Signal Binding by the Pseudomonas aeruginosa Quorum-Sensing Signal Receptor LasR
Authors: Sappington Kaia J. , Dandekar Ajai A. , Oinuma Ken-Ichi , Greenberg E. Peter
Published: February 2011

Many members of the LuxR family of acyl-homoserine lactone (acyl-HSL)-dependent quorum-sensing transcriptional activators are thought to have the unusual characteristics of requiring the signal ligand during polypeptide synthesis to fold into an active conformation and of binding signal extraordinarily tightly. This is the case for the
N
-3-oxo-dodecanoyl-HSL-dependent
Pseudomonas aeruginosa
virulence regulator LasR. We present evidence that LasR can fold into an active conformation
in vivo
in the absence of the acyl-HSL ligand. We also present evidence indicating that in the cellular environment, LasR and
N
-3-oxo-dodecanoyl-HSL readily dissociate. After dissociation, LasR can remain in a properly folded conformation capable of reassociating with signal. We present a new model for the folding and signal binding of LasR and other members of the family of transcription factors to which LasR belongs. Our findings have important implications concerning the cellular responses to decreased environmental concentrations of signals and have implications about potential quorum-sensing inhibition strategies.

IMPORTANCE
The opportunistic pathogen
Pseudomonas aeruginosa
causes difficult to treat and incurable diseases. Quorum sensing controls expression of many virulence factors in this bacterium, and the quorum-sensing signal receptor LasR has been targeted for anti-quorum-sensing therapeutic development. The work described here changes the current view about how LasR interacts with the quorum-sensing signal to which it responds. This is of importance for therapeutic development. The experiments also address a poorly studied aspect of quorum sensing: the response to decreases in quorum-sensing signals. This has importance with respect to understanding the ecology and evolution of quorum sensing.
Pitfalls in lymphoma pathology: avoiding errors in diagnosis of lymphoid tissues
Authors: Wilkins Bridget S
Published: February 2011

The complexity involved in the histological interpretation of lymph nodes and other lymphoid tissue specimens suspected of harbouring lymphoma is underappreciated. As with other histology specimens, the quality of sections and background information are crucial but so, increasingly, is the appropriate use of immunocytochemistry and a variety of molecular analyses. Within the UK National Health Service, progressive regional centralisation is ongoing, to ensure access to specialist expertise and a full range of testing beyond traditional stains. This is to be welcomed but there remains a need to maintain skills in smaller district hospitals, to ensure lymphoma recognition in unexpected circumstances, to permit clinically useful interim diagnoses when needed urgently and to sustain training in haematopathology among junior pathologists. In this review a range of potential pitfalls in lymphoid tissue pathology is outlined, arising at all stages from specimen preparation to reporting. Knowledge of such pitfalls, some of which are common while others are rare but of vital clinical importance, should help increase confidence in lymphoma diagnosis among histopathologists.
Association between bovine digital dermatitis treponemes and a range of ‘non‐healing’ bovine hoof disorders
Authors: Evans N. J. , Blowey R. W. , Timofte D. , Isherwood D. R. , Brown J. M. , Murray R. , Paton R. J. , Carter S. D.
Published: February 2011

This study describes the association between bovine digital dermatitis (BDD) treponemes and three ‘non‐healing’ bovine hoof horn lesions, namely, ‘toe necrosis’ (TN), ‘non‐healing white line disease’ (nhWLD) and ‘non‐healing sole ulcer’ (nhSU), which are disorders that involve penetration through the horn capsule to involve the corium. In this study, these non‐healing disorders (n=44) were identified as foot lesions that exhibited a topical granular appearance, exuded a typical pungent smell, were severely painful to the animal involved, and typically originated from farms where BDD is endemic. Given the similarities between these ‘non‐healing’ lesions and BDD, the authors subjected samples of diseased tissue to PCR assays to detect the presence of DNA of BDD treponemes. All the three characterised BDD treponeme groups were identified as present together in 84.2, 81.3 and 55.6 per cent of samples of TN (n=19), nhWLD (n=16) and nhSU (n=9), respectively. In contrast, healthy control horn samples from similar sites (n=16) were PCR‐negative for the BDD treponemes. Hence, these non‐healing hoof lesions were strongly associated with BDD treponemes. Samples from typical heel horn erosions (n=9) were also subjected to BDD treponeme PCR assays and no association could be identified between the BDD treponemes and this horn manifestation.
Phenotypic association between energy balance indicators and reproductive performance in primiparous Holstein cows
Authors: Valergakis G. E. , Oikonomou G. , Arsenos G. , Banos G.
Published: February 2011

Energy balance was assessed during the first 13 weeks postpartum in 497 primiparous Holstein cows and the relationship with reproductive performance was investigated. A significant association was observed between body condition score (BCS) and a number of reproductive traits, including conception at first artificial insemination (AI), number of inseminations per conception, calving to conception and calving intervals, percentage pregnant by the end of a 305‐day lactation and incidence of metritis. The BCS from calving to week 9 (before the first AI) appeared to adequately predict future reproductive performance as it was correlated with calving interval, conception at first AI, metritis and percentage pregnant by the end of a 305‐day lactation. Plasma β‐hydroxybutyrate (BHB) concentrations were correlated with the latter trait only, whereas non‐esterified fatty acid concentrations were not associated with reproductive performance.
Comparison of oral versus parenteral iron supplementation on the health and productivity of piglets
Authors: Maes D. , Steyaert M. , Vanderhaeghe C. , López Rodríguez A. , de Jong E. , del Pozo Sacristán R. , Vangroenweghe F. , Dewulf J.
Published: February 2011

The aim of this study was to compare oral iron supplementation in feed with a standard iron injection and assess the impact on the health and productivity of pigs. The reliability of a quick test (HemoCue) for the measurement of blood haemoglobin concentration was also investigated. Three pig herds, with a total of 88 sows and their piglets, were included in the study. Piglets in treatment group O were fed a special iron‐rich feed on days 2 to 4, 5 to 7 and 8 to 12 of lactation using a specially designed feeding device. Piglets in group IM received 200 mg of an iron dextran complex intramuscularly at three days of age. Haemoglobin concentrations and performance of the piglets were compared between groups. The mean haemoglobin concentrations in pigs at weaning were 131.4 and 116.4 g/l for pigs in groups O and IM, respectively (P<0.01). Daily weight gain (253.9 v 248.8 g/day) and piglet mortality (11.4 v 12.2 per cent) were slightly better in group O than in group IM (P>0.05).
RADIATIVE ACTIVITY OF MAGNETIC WHITE DWARF UNDERGOING LORENTZ-FORCE-DRIVEN TORSIONAL VIBRATIONS
Authors: BASTRUKOV S. I. , YU J. W. , XU R. X. , MOLODTSOVA I. V.
Published: February 2011

We study radiative activity of magnetic white dwarf undergoing torsional vibrations about axis of its own dipole magnetic moment under the action of Lorentz restoring force. It is shown that pulsating white dwarf can convert its vibration energy into the energy of magneto-dipole emission, oscillating with the frequency equal to the frequency of Alfvén torsional vibrations, provided that internal magnetic field is decayed. The most conspicuous feature of the vibration energy powered radiation in question is the lengthening of periods of oscillating emission; the rate of period elongation is determined by the rate magnetic field decay.
EXTENDED OPTICAL MODEL ANALYSES FOR 9Be + 144Sm SYSTEM NEAR COULOMB BARRIER ENERGIES
Authors: SO W. Y. , KIM K. S.
Published: February 2011

Within the framework of an extended optical model, we study elastic scattering and fusion cross section data for 9 Be + 144 Sm system near Coulomb barrier energies to determine the polarization potential decomposed into direct reaction and fusion parts. We show that the direct reaction and fusion potentials extracted from χ2 analyses separately satisfy the dispersion relation and that the threshold anomaly exhibits in the fusion part. The analyses using only elastic scattering and fusion data can furnish very consistent and reliable predictions of cross sections even though the direct reaction cross section data are not enough. From these analyses, we also obtain the semi-experimental α single and α–α coincidence cross sections, [Formula: see text] and [Formula: see text], for 9 Be + 144 Sm system.
f-SYMBOLS, KILLING TENSORS AND CONSERVED BEL-TYPE CURRENTS
Authors: TINTAREANU-MIRCEA OVIDIU
Published: February 2011

In the framework of the General Relativity we show that from three generalizations of Killing vector fields, namely f-symbols, symmetric Stäckel–Killing and antisymmetric Killing–Yano tensors, some conserved currents can be obtained through adequate contractions of the above-mentioned objects with rank-four tensors having the properties of Bel or Bel–Robinson tensors in Einstein spaces.
EFFECTS OF HYDROSTATIC PRESSURE AND POLARONIC EFFECTS ON THE CORRELATION ENERGIES IN A SPHERICAL QUANTUM DOT
Authors: SIVAKAMI A. , REJO JEICE A. , NAVANEETHAKRISHNAN K.
Published: February 2011

The correlation energies in a singlet and in a triplet state of a two-electron quantum dot in a finite barrier square well potential are computed. Closed analytical expressions are obtained in the perturbation method. Effects of band non-parabolicity and polaronic correction are included. Effects of hydrostatic pressure on the correlation energies are computed. Our results show that (i) the correlation energies in the triplet state are negative, reflecting the exchange interaction, (ii) both the singlet and triplet state correlation energies approach zero as the dot size approaches infinity, (iii) while the band non-parabolicity and the polaronic effects are not significant in the estimation of correlation energies, they however decrease the total confined energies to a maximum of 43% in the triplet state, and (iv) the hydrostatic pressure affects the confined energies appreciably for narrow dots only. The interesting cross-over behavior of the triplet and the singlet state energies at a particular dot radius is explained physically.
ELECTRONIC, MECHANICAL AND OPTICAL PROPERTIES OFSi3P4ANDGe3P4: ANAB INITIOSTUDY
Authors: GOPAL KHAN GOBINDA , CLARK S. J. , BANDYOPADHYAY N. R.
Published: February 2011

First principles total energy calculations within the density functional formalism have been used to investigate the electronic, mechanical, and optical properties of pseudocubic- Si3P4and Ge3P4. Considering the technological importance of the Si/Ge -Group-V elements, we have concentrated mainly on the comparatively less studied, but energetically more favorable pseudocubic- Si3P4and Ge3P4structures of the Si and Ge phosphides. We find that the electronic band structures show that pseudocubic- Si3P4and Ge3P4are both indirect band semiconductors with very low density functional band gaps of 0.24 eV and 0.13 eV, respectively. We also calculate mechanical properties of the materials, such as the bulk modulus, elastic constants, shear modulus, and Vickers hardness of the two phosphides. We find that the bulk and shear modulus of pseudocubic- Si3P4and Ge3P4are 76.18 GPa and 58.37 GPa, and 59.99 GPa and 46.92 GPa, respectively. Pseudocubic- Si3P4and Ge3P4have low Vickers hardness, nearly 18.88 and 16.86 GPa, respectively. Moreover, optical parameters, including dielectric function, refractive index, optical absorption, energy loss function, and plasma frequency are also studied.
A SIGNAL LIGHT MODEL AND ITS STABILITY ANALYSIS
Authors: TANG T. Q. , HUANG H. J. , ZHAO S. G.
Published: February 2011

Based on the effects that signal light has on car-following behavior, this paper developed a new signal light model. Numerical tests show that our model can reproduce the cluster, the dissipation and the propagation of the stopping waves and starting waves resulted by signal light. Finally, linear stability analysis and simulation show that our model is always stable.
TRIBOLOGICAL BEHAVIOUR OF KFRE COMPOSITE
Authors: CHIN C. W. , YOUSIF B. F.
Published: February 2011

This paper presents an attempt to use kenaf fibres as reinforcement for tribo-polymeric composite. Kenaf fibres reinforced epoxy (KFRE) composite was fabricated using a closed mould technique associated with vacuum system. Adhesive wear and frictional behaviour of the composite and neat epoxy (NE) were studied against polished stainless steel counterface using a newly developed block-on-disc (BOD) machine at 50N applied load, sliding distances (0–4.2 km) and sliding velocities of 2.8 m/s. The morphology of the worn surfaces of the composite and NE was studied using a scanning electron microscope (SEM). The result revealed that the longer the sliding distance is, the higher the weight loss. Up to 70% reduction in the weight loss was achieved when the epoxy was reinforced with the kenaf fibres. The wear mechanism was predominated by plastic deformation, in the resinous regions and debonding of fibres.
NON-HARMONIC DNA BENDING ELASTICITY IS REVEALED BY STATISTICS OF DNA MINICIRCLE SHAPES
Authors: CHEN HU , FU HONGXIA , ZHOU ZHEN , YAN JIE
Published: February 2011

Unusual DNA elasticity has been observed in a few recent experiments for DNA under tight bending conditions. Here we present new experimental evidence demonstrating unusual DNA bending elasticity by analyzing the atomic force microscope (AFM) images of DNA minicircles of sizes 189 and 378 base-pairs that are relaxed on 2D surface. The DNA shape distributions are found in disagreement with the canonical 50 nm persistence length based worm-like chain (WLC) model. Instead, they are found in agreement with the recently proposed flexible defect excitation model and linear subelastic chain (LSEC) model.
DEVELOPMENT OF HIGHLY CONDUCTIVE P-TYPE MICROCRYSTALLINE SILICON FILMS FOR N–I–P FLEXIBLE SOLAR CELLS APPLICATION
Authors: LEI Q. S. , XU H. X. , XU J. P.
Published: February 2011

In this paper, we reported highly conductive p-type microcrystalline silicon (μc- Si:H ) films deposited on amorphous silicon (a- Si:H ) surface by very high frequency plasma enhanced chemical vapor deposition (VHF PECVD) technique. Hydrogen plasma treatment of amorphous silicon surface and nucleation layers were introduced prior to μc- Si:H films deposition. The film properties were investigated by using Raman spectra, scanning electron microscope (SEM), optical transmission and reflection, as well as dark conductivity measurements. The influence of plasma treatment and nucleation layer on the growth and properties of the thin p-type μc- Si:H films was studied. It is demonstrated that the hydrogen plasma treatment of a- Si:H films gives rise to the deposition of μc- Si:H on the a- Si:H surface. Also, the growth and properties of the μc- Si:H films are strongly dependent on the nucleation layer. The dark conductivity (σd) and crystalline fraction increase with the plasma treatment time and attain high values at about 600 s. A p-type μc- Si:H film with conductivity of 0.0875 Scm-1 at a thickness of 30 nm was obtained. The film was introduced as window layers for flexible solar cells. An efficiency of about 7.15% was obtained.
A CHAOTIC SECURE COMMUNICATION METHOD BASED ON PARAMETER IDENTIFICATION
Authors: WANG MING-JUN , WANG XING-YUAN
Published: February 2011

Based on parameter identification, an observer is presented to identify the unknown parameter of hyperchaotic Chen system, then the useful information modulated in the parameter can be recovered successfully. In the improved scheme, an approximate observer is adopted for more security. Numerical simulations show the effectiveness of our method.
THE PATH INTEGRAL APPROACH TO AN N-PARTICLE IN A PT-SYMMETRIC HARMONIC OSCILLATOR
Authors: YOO-KONG SIKARIN
Published: February 2011

We study a path integral approach to a system of particles in a PT-symmetric harmonic potential: V(x)=mω2(x2±2iεx)/2. The eigenvalues and eigenstates of the system have been calculated. We find that the total energy of the system is real. The connection between the non-Hermitian and Hermitian Hamiltonians has been discussed and we also establish this connection in the context of path integrals via a considering model.
EXPERIMENTAL OVERVIEW AND CHALLENGE IN STRANGENESS NUCLEAR PHYSICS — STRANGENESS IN THE PAST AND COMING DECADES
Authors: Imai Ken'ichi
Published: February 2011

A great progress has been made in strangeness nuclear physics in the past decade. Examples are; 1) The "hyperfine" structure of hypernuclei were measured with the Hyperball, and ΛN spin dependent interactions in p -shell hypernuclei were determined. 2) The "complete measurements" of the weak decay of hypernuclei were made and the np ratio puzzle in the non-mesonic decay was solved. 3) The discovery of a clean event of "Lambpha" and determination of its binding energy concluded that the Λ-Λ interaction is weak attractive. However, we still have important questions to be answered in this field, especially in relation with QCD and nuclear physics. For the future strangeness nuclear physics, we have and will have facilities such as JLab, SPring-8, Daphne, J-PARC, FAIR. We discuss experimental challenges in the strangeness nuclear physics and related fields in the next decade.
STRANGENESS PHOTOPRODUCTION AT ELSA
Authors:   For the CBELSA/TAPS Collaboration, Kleber Vera
Published: February 2011

Photoproduction of hyperons is a promising channel to achieve a complete amplitude analysis. Many observables have been measured and interpreted. The status is discussed here. Recent data obtained with the Crystal Barrel/TAPS setup at ELSA are shown and future plans for hyperon photoproduction are presented.