bluuebunny/crossref_metadata_2025 huggingface dataset:
Aerodynamics of the knuckleball pitch: Experimental measurements on slowly rotating baseballs
Authors: Borg John P. , Morrissey Michael P.
Published: September 2014

In this work, we characterize the lift and lateral forces on a two-seam versus four-seam knuckleball and measure the viscous shear stress. We believe these measurements to be the first reported for slowly rotating baseballs. Our findings indicate the seam acts to either delay or advance separation depending upon the ball angle; these results are supported with flow visualization. The combined effect produces significant lift and lateral forces that can rapidly change as the ball rotates. Furthermore, we found the shear stress to be asymmetric which can result in significant in-flight torque. Together, asymmetries in force and shear stress produce the complicated flight trajectories that can confound the hapless batter.
Simple calculation of the critical mass for highly enriched uranium and plutonium-239
Authors: Chyba Christopher F. , Milne Caroline R.
Published: September 2014

The correct calculation of and values for the critical mass of uranium or plutonium necessary for a nuclear fission weapon have long been understood and publicly available. The calculation requires solving the radial component in spherical coordinates of a diffusion equation with a source term, so is beyond the reach of most public policy and many first-year college physics students. Yet it is important for the basic physical ideas behind the calculation to be understood by those without calculus who are nonetheless interested in international security, arms control, or nuclear non-proliferation. This article estimates the critical mass in an intuitive way that requires only algebra.
Visible optical beats at the hertz level
Authors: McDonald Mickey , Ha Jiyoun , McGuyer Bart H. , Zelevinsky Tanya
Published: September 2014

We present a lecture demonstration that produces a visible, beating interference pattern that is the optical analog of demonstrations that produce audible, beating sound-wave interference. The setup is a compact, portable Mach-Zehnder interferometer made of optical components commonly found in laser physics laboratories. This apparatus may also be built and used in advanced laboratory courses to illustrate concepts in interferometry and laser light modulation.
Relationship Between General Nutrition Knowledge and Dietary Quality in Elite Athletes
Authors: Spronk Inge , Heaney Susan E. , Prvan Tania , O’Connor Helen T.
Published: September 2014

This study investigated the association between general nutrition knowledge and dietary quality in a convenience sample of athletes (> state level) recruited from four Australian State Sport Institutes. General nutrition knowledge was measured by the validated General Nutrition Knowledge Questionnaire and diet quality by an adapted version of the Australian Recommended Food Score (A-ARFS) calculated from food frequency questionnaire data. Analysis of variance and linear modeling were used to assess relationships between variables. Data: mean (Standard Deviation). A total of 101 athletes (Males: 37; Females: 64), 18.6 (4.6) years were recruited mainly from team sports (72.0%). Females scored higher than males for both nutrition knowledge (Females: 59.9%; Males: 55.6%; p = .017) and total A-ARFS (Females: 54.2% Males: 49.4%; p = .016). There was no significant influence of age, level of education, athletic caliber or team/individual sport participation on nutrition knowledge or total A-ARFS. However, athletes engaged in previous dietetic consultation had significantly higher nutrition knowledge (61.6% vs. 56.6%; p = .034) but not total A-ARFS (53.6% vs. 52.0%; p = .466). Nutrition knowledge was weakly but positively associated with total A-ARFS (r = .261, p= .008) and A-ARFS vegetable subgroup (r = .252, p = .024) independently explaining 6.8% and 5.1% of the variance respectively. Gender independently explained 5.6% of the variance in nutrition knowledge (p = .017) and 6.7% in total A-ARFS (p = .016). Higher nutrition knowledge and female gender were weakly but positively associated with better diet quality. Given the importance of nutrition to health and optimal sports performance, intervention to improve nutrition knowledge and healthy eating is recommended, especially for young male athletes.
Signaling mechanisms of the epithelial-mesenchymal transition
Authors: Gonzalez David M. , Medici Damian
Published: September 2014

Signals from the microenvironment trigger epithelial-mesenchymal transition in development and disease through multiple, crosstalking pathways.
Comment on “Controlling long-term signaling: Receptor dynamics determine attenuation and refractory behavior of the TGF-β pathway”—Smad2/3 activity does not predict the dynamics of transcription
Authors: Warmflash Aryeh , Zhang Qixiang , Brivanlou Ali H. , Siggia Eric D.
Published: September 2014

This pair of Letters discusses the differences between analyzing the dynamics of TGF-β signaling by measuring Smad phosphorylation or by assaying target gene expression.
Response to comment on “Controlling long-term signaling: Receptor dynamics determine attenuation and refractory behavior of the TGF-β pathway”—Smad2/3 activity does not predict the dynamics of transcription
Authors: Vizán Pedro , J. Miller Daniel S. , Schmierer Bernhard , Hill Caroline S.
Published: September 2014

This pair of Letters discusses the differences between analyzing the dynamics of TGF-β signaling by measuring Smad phosphorylation or by assaying target gene expression.
Human Stem Cell Expansion
Authors: Purnell Beverly A.
Published: September 2014

The self-renewal of human hematopoietic stem cells in vitro is enhanced by the pyrimidoindole derivative UM171.
Targeting the “Undruggable” MYCN
Authors: Ferrarelli Leslie K.
Published: September 2014

A drug that alters the conformation of the kinase Aurora A prevents its stabilizing interaction with the oncogenic transcription factor MYCN.
Urothelial Carcinogenesis: A Tale of Two Cells
Authors: Faltas Bishoy M.
Published: September 2014

A study in a mouse model of chemical-induced bladder cancer shows different cells of origin for different histopathologiocal types of urothelial carcinoma.
Picturing Inflammation in Blood Vessels
Authors: Stecker Eric C.
Published: September 2014

Investigators have successfully imaged the dynamics of leukocyte infiltration into atherosclerotic plaques in humans.
Refining the Balance of Attenuation and Immunogenicity of Respiratory Syncytial Virus by Targeted Codon Deoptimization of Virulence Genes
Authors: Meng Jia , Lee Sujin , Hotard Anne L. , Moore Martin L.
Published: September 2014

Respiratory syncytial virus (RSV) is the most important pathogen for lower respiratory tract illness in children for which there is no licensed vaccine. Live-attenuated RSV vaccines are the most clinically advanced in children, but achieving an optimal balance of attenuation and immunogenicity is challenging. One way to potentially retain or enhance immunogenicity of attenuated virus is to mutate virulence genes that suppress host immune responses. The NS1 and NS2 virulence genes of the RSV A2 strain were codon deoptimized according to either human or virus codon usage bias, and the resulting recombinant viruses (dNSh and dNSv, respectively) were rescued by reverse genetics. RSV dNSh exhibited the desired phenotype of reduced NS1 and NS2 expression. RSV dNSh was attenuated in BEAS-2B and primary differentiated airway epithelial cells but not in HEp-2 or Vero cells. In BALB/c mice, RSV dNSh exhibited a lower viral load than did A2, and yet it induced slightly higher levels of RSV-neutralizing antibodies than did A2. RSV A2 and RSV dNSh induced equivalent protection against challenge strains A/1997/12-35 and A2-line19F. RSV dNSh caused less STAT2 degradation and less NF-κB activation than did A2
in vitro
. Serial passage of RSV dNSh in BEAS-2B cells did not result in mutations in the deoptimized sequences. Taken together, RSV dNSh was moderately attenuated, more immunogenic, and equally protective compared to wild-type RSV and genetically stable.

IMPORTANCE
Respiratory syncytial virus (RSV) is the leading cause of infant viral death in the United States and worldwide, and no vaccine is available. Live-attenuated RSV vaccines are the most studied in children but have suffered from genetic instability and low immunogenicity. In order to address both obstacles, we selectively changed the codon usage of the RSV nonstructural (NS) virulence genes NS1 and NS2 to the least-used codons in the human genome (deoptimization). Compared to parental RSV, the codon-deoptimized NS1/NS2 RSV was attenuated
in vitro
and in mice but induced higher levels of neutralizing antibodies and equivalent protection against challenge. We identified a new attenuating module that retains immunogenicity and is genetically stable, achieved through specific targeting of nonessential virulence genes by codon usage deoptimization.
An ABC Transporter Is Required for Secretion of Peptide Sex Pheromones in Enterococcus faecalis
Authors: Varahan Sriram , Harms Nathan , Gilmore Michael S. , Tomich John M. , Hancock Lynn E.
Published: September 2014

Enterococci are leading causes of hospital-acquired infection in the United States and continue to develop resistances to new antibiotics. Many
Enterococcus faecalis
isolates harbor pheromone-responsive plasmids that mediate horizontal transfer of even large blocks of chromosomal genes, resulting in hospital-adapted strains over a quarter of whose genomes consist of mobile elements. Pheromones to which the donor cells respond derive from lipoprotein signal peptides. Using a novel bacterial killing assay dependent on the presence of sex pheromones, we screened a transposon mutant library for functions that relate to the production and/or activity of the effector pheromone. Here we describe a previously uncharacterized, but well-conserved, ABC transporter that contributes to pheromone production. Using three distinct pheromone-dependent mating systems, we show that mutants defective in expressing this transporter display a 5- to 6-order-of-magnitude reduction in conjugation efficiency. In addition, we demonstrate that the ABC transporter mutant displays an altered biofilm architecture, with a significant reduction in biofilm biomass compared to that of its isogenic parent, suggesting that pheromone activity also influences biofilm development. The conservation of this peptide transporter across the
Firmicutes
suggests that it may also play an important role in cell-cell communication in other species within this important phylum.

IMPORTANCE
Enterococcus faecalis
ranks as one of the leading causes of hospital-associated infections. Strains possessing resistance to multiple antibiotics are becoming all too common in clinical settings. Pheromone-responsive plasmids play an important role in harboring and disseminating these antibiotic resistance genes. Here we have identified a novel ABC transporter that is responsible for the secretion of peptide pheromones, which enables communication between cells to mediate plasmid transfer. We have also shown that this transporter is important for biofilm formation, providing a strong rationale for its use as a viable therapeutic target which could be targeted to curb infection, as well as the spread of existing drug resistance.
Identification of a Novel Conjugative Plasmid in Mycobacteria That Requires Both Type IV and Type VII Secretion
Authors: Ummels Roy , Abdallah Abdallah M. , Kuiper Vincent , Aâjoud Anouar , Sparrius Marion , Naeem Raeece , Spaink Herman P. , van Soolingen Dick , Pain Arnab , Bitter Wilbert
Published: September 2014

Conjugative plasmids have been identified in a wide variety of different bacteria, ranging from proteobacteria to firmicutes, and conjugation is one of the most efficient routes for horizontal gene transfer. The most widespread mechanism of plasmid conjugation relies on different variants of the type IV secretion pathway. Here, we describe the identification of a novel type of conjugative plasmid that seems to be unique for mycobacteria. Interestingly, while this plasmid is efficiently exchanged between different species of slow-growing mycobacteria, including
Mycobacterium tuberculosis
, it could not be transferred to any of the fast-growing mycobacteria tested. Genetic analysis of the conjugative plasmid showed the presence of a locus containing homologues of three type IV secretion system components and a relaxase. In addition, a new type VII secretion locus was present. Using transposon insertion mutagenesis, we show that in fact both these secretion systems are essential for conjugation, indicating that this plasmid represents a new class of conjugative plasmids requiring two secretion machineries. This plasmid could form a useful new tool to exchange or introduce DNA in slow-growing mycobacteria.

IMPORTANCE
Conjugative plasmids play an important role in horizontal gene transfer between different bacteria and, as such, in their adaptation and evolution. This effect is most obvious in the spread of antibiotic resistance genes. Thus far, conjugation of natural plasmids has been described only rarely for mycobacterial species. In fact, it is generally accepted that
M. tuberculosis
does not show any recent sign of horizontal gene transfer. In this study, we describe the identification of a new widespread conjugative plasmid that can also be efficiently transferred to
M. tuberculosis
. This plasmid therefore poses both a threat and an opportunity. The threat is that, through the acquisition of antibiotic resistance markers, this plasmid could start a rapid spread of antibiotic resistance genes between pathogenic mycobacteria. The opportunity is that we could use this plasmid to generate new tools for the efficient introduction of foreign DNA in slow-growing mycobacteria.
Acute onset and rapid progression of multiple organ failure in a young adult with undiagnosed disseminated colonic adenocarcinoma
Authors: Frestad Daria , Perner Anders , Pedersen Ulf Gøttrup
Published: September 2014

Colourectal cancer (CRC) is the fourth most common cause of death from cancer worldwide. While rates for CRC in adults age 50 and older have been declining, incidence rates in young adults, a population routinely not screened, has been increasing. We report a rare case of high-grade CRC in a previously healthy 27-year-old man, presented to us with symptoms of increasing abdominal pain and distension. Extensive diagnostic investigation revealed hepatomegaly with multiple processes, signs of vasculitis, extensive liver necrosis, enlarged retroperitoneal and mesenteric lymph nodes, splenomegaly, ascites and multiple vein thrombosis. The patient passed away shortly after admission due to treatment-resistant tumour lysis syndrome and multiple organ failure. Biopsy results revealed disseminated adenocarcinoma of the colon, with metastases to lymph nodes, liver, lungs and pleura. CRC in younger patients tend to present at a later stage and appears to be more aggressive, with a poorer pathological differentiation.
A rare primary immunodeficiency
Authors: Nagaraj Poornima , Sivathanu Shobhana , Sampath Sowmya , Ramakrishnan Nithiyanantham
Published: September 2014

A 9-year-old girl presented with failure to thrive, chronic mucopurulent nasal discharge, recurrent skin pustules and recurrent episodes of purulent ear discharge since 2 years of age. She had coarse facial features with extensive eczema, multiple pyoderma scars, florid dental caries, retained primary dentition, hypermobile joints and a woody induration of the vulva. Autosomal dominant hyper-IgE syndrome was suspected and confirmed by very high serum IgE levels. Vulval biopsy revealed a premalignant condition. STAT 3 mutation, which is usually responsible for this condition, was not found in our case, indicating an as yet unidentified mutation. The child also had unusual features like the total absence of clinical and radiological features of pneumonia. The premalignant change in the vulva was also unusual since vulval carcinoma has not been reported so far in children with this disorder. This child will require a close follow-up to look for malignant transformation.
Spinal tuberculosis presenting with hip abscesses: a diagnostic challenge
Authors: Araújo Gabriel Costa Serrão de , Ferreira Junior Diógenes de Souza , Escarso Junior Lessandro da Rocha , Gameiro Vinícius Schott
Published: September 2014

Spinal tuberculosis is the most common manifestation of extra-pulmonary tuberculosis. It is difficult to diagnose the disease due to its insidious onset and non-specific clinical presentation. A high degree of suspicion and appropriate imaging studies are necessary for its early diagnosis and treatment. The authors report a case of lumbosacral tuberculosis in an adult patient presenting with hip pain and abscesses.
Musical hallucinations responding to a further increase of carbamazepine
Authors: Aizawa Saeko , Terao Takeshi , Hatano Koji , Ishii Nobuyoshi
Published: September 2014

A 73-year-old woman outpatient with mild cognitive impairment, parasomnia and depressive state with musical hallucinations failed to respond to 400 mg/day of valproate. Once she was admitted to a university hospital, her musical hallucinations partially responded to 1 mg/day of clonazepam and sufficiently improved on 100 mg/day of carbamazepine. Two months after discharge, however, her musical hallucinations recurred probably as a consequence of psychological stress. The increase of carbamazepine from 100 to 200 mg/day completely remitted her musical hallucinations. This case suggests that musical hallucinations respond in a dose-dependent manner to increasing carbamazepine, and that gradual titration from small doses of carbamazepine is required because optimal doses appear to be smaller than those required for epilepsy and bipolar disorder. Further studies are warranted to determine the therapeutic levels of carbamazepine for musical hallucinations.
Tumour seeding as a result of intraperitoneal perforation during transurethral resection of non-muscle invasive bladder cancer
Authors: Cusano Antonio , Murphy Greg , Haddock Peter , Wagner Joseph
Published: September 2014

The goals of transurethral resection of bladder tumour (TURBT) for urothelial carcinoma are pathological staging and the removal of all visible tumour tissue. Typically, a deep and extensive resection beyond the basement membrane, including some muscularis propria, is performed. However, this also carries a risk of perforating the bladder wall, creating the ideal circumstances to facilitate peritoneal or abdominal metastases. Small, asymptomatic bladder perforations occur frequently and are associated with gender: female, decreasing body mass index, higher tumour stage, deeper infiltration and higher resection weight. Since many of these perforations are extraperitoneal, heal spontaneously and do not elicit any significant perioperative symptoms, they remain undiagnosed. Even in cases of intraperitoneal perforation, peritoneal tumour recurrence has been rarely reported. We report on the unusual case of a 61-year-old woman who underwent TURBT for non-muscle invasive urothelial carcinoma that was complicated by intraperitoneal bladder perforation requiring open repair.
Disentangling quality and safety indicator data: a longitudinal, comparative study of hand hygiene compliance and accreditation outcomes in 96 Australian hospitals
Authors: Mumford Virginia , Greenfield David , Hogden Anne , Debono Deborah , Gospodarevskaya Elena , Forde Kevin , Westbrook Johanna , Braithwaite Jeffrey
Published: September 2014

Objectives

The study aims are twofold. First, to investigate the suitability of hand hygiene as an indicator of accreditation outcomes and, second, to test the hypothesis that hospitals with better accreditation outcomes achieve higher hand hygiene compliance rates.

Design

A retrospective, longitudinal, multisite comparative survey.

Setting

Acute public hospitals in New South Wales, Australia.

Participants

96 acute hospitals with accreditation survey results from two surveys during 2009–2012 and submitted data for more than four hand hygiene audits between 2010 and 2013.

Outcomes

Our primary outcome comprised observational hand hygiene compliance data from eight audits during 2010–2013. The explanatory variables in our multilevel regression model included: accreditation outcomes and scores for the infection control standard; timing of the surveys; and hospital size and activity.

Results

Average hand hygiene compliance rates increased from 67.7% to 80.3% during the study period (2010–2013), with 46.7% of hospitals achieving target compliance rates of 70% in audit 1, versus 92.3% in audit 8. Average hand hygiene rates at small hospitals were 7.8 percentage points (pp) higher than those at the largest hospitals (p<0.05). The association between hand hygiene rates, accreditation outcomes and infection control scores is less clear.

Conclusions

Our results indicate that accreditation outcomes and hand hygiene audit data are measuring different parts of the quality and safety spectrum. Understanding what is being measured when selecting indicators to assess the impact of accreditation is critical as focusing on accreditation results would discount successful hand hygiene implementation by smaller hospitals. Conversely, relying on hand hygiene results would discount the infection control related research and leadership investment by larger hospitals. Our hypothesis appears to be confounded by an accreditation programme that makes it more difficult for smaller hospitals to achieve high infection control scores.
Impact of introducing an electronic physiological surveillance system on hospital mortality
Authors: Schmidt Paul E , Meredith Paul , Prytherch David R , Watson Duncan , Watson Valerie , Killen Roger M , Greengross Peter , Mohammed Mohammed A , Smith Gary B
Published: September 2014

Background

Avoidable hospital mortality is often attributable to inadequate patient vital signs monitoring, and failure to recognise or respond to clinical deterioration. The processes involved with vital sign collection and charting; their integration, interpretation and analysis; and the delivery of decision support regarding subsequent clinical care are subject to potential error and/or failure.

Objective

To determine whether introducing an electronic physiological surveillance system (EPSS), specifically designed to improve the collection and clinical use of vital signs data, reduced hospital mortality.

Methods

A pragmatic, retrospective, observational study of seasonally adjusted in-hospital mortality rates in three main hospital specialties was undertaken before, during and after the sequential deployment and ongoing use of a hospital-wide EPSS in two large unconnected acute general hospitals in England. The EPSS, which uses wireless handheld computing devices, replaced a paper-based vital sign charting and clinical escalation system.

Results

During EPSS implementation, crude mortality fell from a baseline of 7.75% (2168/27 959) to 6.42% (1904/29 676) in one hospital (estimated 397 fewer deaths), and from 7.57% (1648/21 771) to 6.15% (1614/26 241) at the second (estimated 372 fewer deaths). At both hospitals, multiyear statistical process control analyses revealed abrupt and sustained mortality reductions, coincident with the deployment and increasing use of the system. The cumulative total of excess deaths reduced in all specialties with increasing use of the system across the hospital.

Conclusions

The use of technology specifically designed to improve the accuracy, reliability and availability of patients’ vital signs and early warning scores, and thereby the recognition of and response to patient deterioration, is associated with reduced mortality in this study.
Concordance between digital pathology and light microscopy in general surgical pathology: a pilot study of 100 cases
Authors: Houghton Joseph P , Ervine Aaron J , Kenny Sarah L , Kelly Paul J , Napier Seamus S , McCluggage W Glenn , Walsh Maureen Y , Hamilton Peter W
Published: September 2014

Aim

(1) A pilot study to determine the accuracy of interpretation of whole slide digital images in a broad range of general histopathology cases of graded complexity. (2) To survey the participating histopathologists with regard to acceptability of digital pathology.

Materials and methods

Glass slides of 100 biopsies and minor resections were digitally scanned in their entirety, producing digital slides. These cases had been diagnosed by light microscopy at least 1 year previously and were subsequently reassessed by the original reporting pathologist (who was blinded to their original diagnosis) using digital pathology. The digital pathology-based diagnosis was compared with the original glass slide diagnosis and classified as concordant, slightly discordant (without clinical consequence) or discordant. The participants were surveyed at the end of the study.

Results

There was concordance between the original light microscopy diagnosis and digital pathology-based diagnosis in 95 of the 100 cases while the remaining 5 cases showed only slight discordance (with no clinical consequence). None of the cases were categorised as discordant. Participants had mixed experiences using digital pathology technology.

Conclusions

In the broad range of cases we examined, digital pathology is a safe and viable method of making a primary histopathological diagnosis.
Matrix geometries emergent from a point
Authors: D'Andrea Francesco , Lizzi Fedele , Martinetti Pierre
Published: September 2014

We describe a categorical approach to finite noncommutative geometries. Objects in the category are spectral triples, rather than unitary equivalence classes as in other approaches. This enables us to treat fluctuations of the metric and unitary equivalences on the same footing, as representatives of particular morphisms in this category. We then show how a matrix geometry (Moyal plane) emerges as a fluctuation from one point, and discuss some geometric aspects of this space.
Around Shannon's interpretation for entropy-preserving stochastic averages
Authors: Choda Marie
Published: September 2014

Let Φ be a positive unital Tr-preserving map on Mn(ℂ). We give various characterizations for Φ to preserve the von Neumann entropy of a state ρ on Mn(ℂ). Among others, it is given by that Φ behaves to ρ as a *-automorphism. This is also equivalent to that the entropy of the stochastic matrix arising from {ρ, Φ} is zero.
A UNISTABLE POLYHEDRON WITH 14 FACES
Authors: RESHETOV ALEXANDER
Published: September 2014

Unistable polyhedra are in equilibrium on only one of their faces. The smallest known homogeneous unistable polyhedron to date has 18 faces. Using a new optimization algorithm, we have found a unistable polyhedron with only 14 faces, which we believe to be a lower bound. Despite the simplicity of the formulation, computers were never successfully used for solving this problem due to the seemingly insurmountable dimensionality of the underlying mathematical apparatus. We introduce new optimization approaches designed to overcome the problem's intractability and discuss its significance to other application areas. We also mathematically prove the unistable property of the found bodies using rational arithmetic. Surprisingly enough, all of our computer-generated unistable polyhedra look similar to the human eye, providing important insights into the nature of the problem.
On the equivalence of two fundamental theta identities
Authors: Koornwinder Tom H.
Published: September 2014

Two fundamental theta identities, a three-term identity due to Weierstrass and a five-term identity due to Jacobi, both with products of four theta functions as terms, are shown to be equivalent. One half of the equivalence was already proved by R. J. Chapman in 1996. The history and usage of the two identities, and some generalizations are also discussed.
Different-Oxides Nanoceramics Microhardness
Authors: Lysenko Vladimir
Published: September 2014

With help of the method of the spark plasma sintering (SPS), the fine-grained (of micron approximately) ceramics based on various alumina nanopowders had created. A comparison of microhardness of ceramic samples obtained from 11 alumina nanopowders and 2 their composites was held. Microhardness of the ceramics obtained both by SPS, and by the traditional method (at successive pressing and sintering) is compared. The dependence of ceramics microhardness on the phase composition of the initial nanopowder and the average size of its particles was investigated. Besides alumina nanopowders ( Al 2 O 3), there were compared microhardness of ceramics from other 10 nanopowders of oxides ( SiO 2, ZnO , Fe 3 O 4, Gd 2 O 3, CuO , WO 3, TiO 2, Y 2 O 3, ZrO 2, MgO ) obtained both by SPS, and by the traditional method. It is obtained that the microhardness of the ceramics created on the method of the spark plasma sintering, is significantly higher than a microhardness of the ceramics obtained by the traditional method; at the SPS method the average size of grain in ceramics decreases (to 1 micron and less).
A Facile Route for Synthesis of Octyl Amine Capped Silver Nanoparticle
Authors: Agasti Nityananda , Kaushik N. K.
Published: September 2014

This paper presents a simple and convenient procedure for the preparation of octyl amine capped silver nanoparticles. AgNO 3 has been reduced by octyl amine with benzene or toluene as solvent at 100°C to produce silver nanoparticles. Octyl amine plays its role both as reducing and capping agent and thus provides the advantage of avoiding the use of extra stabilizing agent. Time dependent formation mechanism of silver nanoparticle has been investigated. Thermo gravimetric analysis (TGA) shows weight change due to loss of capping agent. The reaction can easily be monitored from variation of color with time. The method is easy and reproducible. Very low concentration (1 mM) of metal ion is used. The particles synthesized were characterized by UV-Visible, FTIR, TGA, TEM and X-ray diffraction studies.
Effective Thermal Conductivity of Spherical Particulate Nanocomposites: Comparison with Theoretical Models, Monte Carlo Simulations and Experiments
Authors: Machrafi Hatim , Lebon Georgy
Published: September 2014

The purpose of this work is to study heat conduction in systems that are composed out of spherical micro-and nanoparticles dispersed in a bulk matrix. Special emphasis will be put on the dependence of the effective heat conductivity on various selected parameters as dimension and density of particles, interface interaction with the matrix. This is achieved by combining the effective medium approximation and extended irreversible thermodynamics, whose main feature is to elevate the heat flux vector to the status of independent variable. The model is illustrated by three examples: Silicium-Germanium, Silica-epoxy-resin and Copper-Silicium systems. Predictions of our model are in good agreement with other theoretical models, Monte-Carlo simulations and experimental data.
FLOOD VULNERABILITY AND ADAPTATION TO CLIMATE CHANGE IN BANGLADESH: A REVIEW
Authors: YOUNUS MD ABOUL FAZAL
Published: September 2014

This paper reviews recent literature on flood research in Bangladesh, focusing on the nation's vulnerability to climate change and its ability to adapt. This review reveals that the literature on community-based vulnerability and adaptation, and their processes and assessments in response to hazards under climate change regimes are inadequate, apart from a recent focus on assessment of the vulnerability of rural communities, their ability to adapt their farming methods, or the economic consequences of failure to adapt in response to extreme flood events, e.g. Younus (2012a,b); Younus and Harvey (2013, 2014). This paper argues that an integrated assessment of rural vulnerability and community-based adaptation is needed in order to ensure sustainable changes in response to future climate change regimes in Bangladesh.
ENVIRONMENTAL IMPACTS OF CIVIL EMERGENCY PLANS AND THEIR EXEMPTION FROM SEA
Authors: SWAIN STEVE , THERIVEL RIKI
Published: September 2014

Emergency plans are exempt from undergoing Strategic Environmental Assessment (SEA). However, the measures they include to minimise the effects of disasters can have environmental impacts. The study underlying this paper assessed UK emergency plans for their possible environmental impacts, identified which types of plan would not fulfil the criteria necessary to require SEA and which ones would but are then exempt. Further consideration of the likely practical involvement of environmental authorities in the plan-making process of regulated processes and in emergency responses provided a view on whether the SEA exemption results in environmental impacts not being minimised. This work has highlighted that the implementation of emergency plans is as important as the plans themselves in terms of providing scope for the protection of the environment for the management of spatially generic disasters. Site-specific disaster management tends to include detailed environmental protection measures through regulatory processes.
Blood flow of Carreau fluid in a tapered artery with mixed convection
Authors: Akbar Noreen Sher
Published: September 2014

This research is concerned with the mathematical modeling and analysis of blood flow in a tapered artery with stenosis. The analysis has been carried out in the presence of heat and mass transfer. Constitutive equation of Carreau fluid has been invoked in the mathematical formulation. The representation of blood flow is considered through an axially non-symmetrical but radially symmetric stenosis. Symmetry of the distribution of the wall shearing stress and resistive impedance and their growth with the developing stenosis is given due attention. Solutions have been obtained for the velocity, temperature, concentration, resistance impedance, wall shear stress and shearing stress at the stenosis throat. Graphical illustrations associated with the tapered arteries namely converging, diverging and non-tapered arteries are examined for different parameters of interest. Streamlines have been plotted and discussed.
Stationary patterns for a Leslie–Gower type three species model with diffusion
Authors: Hu Guangping , Li Xiaoling , Lu Shiping
Published: September 2014

In this paper, a diffusive three species predator–prey model with two Leslie–Gower terms is considered. The stability of the unique positive constant equilibrium for the reaction–diffusion system is obtained. Sufficient conditions are derived for the global stability of the positive constant equilibrium. In particular, we establish the existence and non-existence of non-constant positive steady states of this system. The results indicate that the large diffusivity is helpful for the appearance of the non-constant positive steady states (stationary patterns).
Evaluation of the differential capacitance for ferroelectric materials using either charge-based or energy-based expressions
Authors: Krowne C. M.
Published: September 2014

Differential capacitance is derived based upon energy, charge or current considerations, and determined when it may go negative or positive. These alternative views of differential capacitances are analyzed, and the relationships between them are shown. Because of recent interest in obtaining negative capacitance for reducing the subthreshold voltage swing in field effect type of devices, using ferroelectric materials characterized by permittivity, these concepts are now of paramount interest to the research community. For completeness, differential capacitance is related to the static capacitance, and conditions when the differential capacitance may go negative in relation to the static capacitance are shown.
Interventions and Expected Exchange Rates in Emerging Market Economies
Authors: García-Verdú Santiago , Ramos-Francia Manuel
Published: September 2014

We study variations in the risk-neutral distributions of the exchange rates in Brazil, Chile, Colombia, Mexico, and Peru due to interventions implemented by these countries. For this purpose, we first estimate the risk-neutral densities of the exchange rates based on derivatives market data, for one-day and one-week horizons. Second, using a linear regression model, we assess possible effects on the distributions of the expected exchange rates due to these interventions. We find little evidence of an effect on the expected exchange rates' means, volatilities, skewness, kurtoses, risk premia, and tails' parameters. In the few cases for which we do find some statistical evidence of an effect, it tends to be short-lived or not economically significant. On the other hand, we find evidence that interventions which objective is to restore and/or assure the proper functioning of exchange rate markets have a higher probability of success. This probability increases as the amount of resources to intervene at the disposal of the central bank increases. Needless to say, there are limits to the methodology we use.
Blockholder Ownership and Corporate Control: The Role of Liquidity
Authors: Gerken William C.
Published: September 2014

Employing an instrumental variable approach based on the regulatory change of tick sizes, I examine the link between the liquidity of a firm's equity and activism by large shareholders. I find that liquidity increases the likelihood of block formation. Blockholders of more liquid securities take smaller stakes that do not precommit them to monitor. I find evidence that the threat of exit from a block can discipline managers and that this threat is more effective when liquidity is higher. While liquidity increases exit from existing blocks, I find no evidence that share illiquidity that forces blockholders to actively monitor.
Deglaciation, sea-level change and the Holocene colonization of Norway
Authors: Glørstad Håkon
Published: September 2014

The Norwegian coast facing the Atlantic Ocean was ice free as early as the Allerød oscillation in the late Pleistocene. The landscape was probably habitable for humans. It has, therefore, been assumed by several scholars that this coastline was visited or inhabited from the Late Glacial period onwards. In part, this argumentation is based on the presumed proximity of the Norwegian mainland and Doggerland, which existed between present-day Denmark and Great Britain because of a much lower global sea level. The aim of this paper is to examine the
14
C dates available from the oldest Norwegian settlement sites, and to compare them to the Quaternary processes of deglaciation and sea-level change. The hypothesis is advanced that humans did not settle in present-day Norway before a sheltering passage of islands and peninsulas had developed between the Swedish west coast (Bohuslän) and the Oslo area. This happened in the second half of the Preboreal period, at approximately 9.3 cal ka BC, or in the final centuries of the tenth millenniun BC.

Supplementary material:

14
C dates used in Figures 2, 4 and 9 are available at
http://www.geolsoc.org.uk/SUP18779
.
Genetically Engineered Livestock: Ethical Use for Food and Medical Models
Authors: Garas Lydia C. , Murray James D. , Maga Elizabeth A.
Published: September 2014

Recent advances in the production of genetically engineered (GE) livestock have resulted in a variety of new transgenic animals with desirable production and composition changes. GE animals have been generated to improve growth efficiency, food composition, and disease resistance in domesticated livestock species. GE animals are also used to produce pharmaceuticals and as medical models for human diseases. The potential use of these food animals for human consumption has prompted an intense debate about food safety and animal welfare concerns with the GE approach. Additionally, public perception and ethical concerns about their use have caused delays in establishing a clear and efficient regulatory approval process. Ethically, there are far-reaching implications of not using genetically engineered livestock, at a detriment to both producers and consumers, as use of this technology can improve both human and animal health and welfare.
A New Medical Research Model: Ethically and Responsibly Advancing Health for Humans and Animals
Authors: Olson Patricia N. , Ganzert Robin R.
Published: September 2014

With the increasing use of genomics, computational analytics, emerging technologies, and personalized medicine, the possibility of a new research model is emerging. Using the clues from thousands of species living on our planet, scientists from many disciplines (medicine, veterinary medicine, wildlife) must collaborate, prioritize, and strategize on how to address causes of health and disease. Such clues should guide disease prevention, as well as the development of innovative, efficacious, and gentler therapies. Geographic and language barriers must be broken down, and scientists—even within a single academic, corporate, or government research site—must be vigilant in seeking the help of nonmedical disciplines of colleagues from whence answers might come. The public will become more interested in and demanding of such a model, desiring that all family members (humans and animals) have an opportunity for a long and healthy life. Above all, such activities will be humanely conducted with outcomes having the greatest chance for success.
What Are Species Pools and When Are They Important?
Authors: Cornell Howard V. , Harrison Susan P.
Published: September 2014

A regional species pool comprises all species available to colonize a focal site. The roots of the concept are imbedded in island biogeography theory, supply-side ecology, and early propagule addition experiments. The pool concept allows ecologists to examine large-scale effects—including geographic area, evolutionary age, and immigration and diversification—on the diversity, composition, and phylogenetic structure of local communities. Both theory and evidence show that pool influences are greatest when local communities are not strongly and predictably structured by species interactions (e.g., under frequent disturbance or if many species are rare). Practical and conceptual issues to consider when delineating species pools include choosing an appropriate spatial scale, whether to account for environmental filtering, whether to include the species within a fixed geographic area versus those whose geographic ranges overlap with a site, or whether to use databases or geographic data sources. Each issue is discussed in the context of 63 studies using the species pool approach. We conclude that the species pool concept has contributed greatly to our understanding of community dynamics by bridging the gap between large and small spatial scales. Future studies must compare pool characteristics with community structure across multiple regions for a more complete understanding of community assembly.
Modeling the Terrestrial Biosphere
Authors: Fisher Joshua B. , Huntzinger Deborah N. , Schwalm Christopher R. , Sitch Stephen
Published: September 2014

The land surface comprises the smallest areal fraction of the Earth system's major components (e.g., versus atmosphere or ocean with cryosphere). As such, how is it that some of the largest sources of uncertainty in future climate projections are found in the terrestrial biosphere? This uncertainty stems from how the terrestrial biosphere is modeled with respect to the myriad of biogeochemical, physical, and dynamic processes represented (or not) in numerous models that contribute to projections of Earth's future. Here, we provide an overview of the processes included in terrestrial biosphere models (TBMs), including various approaches to representing any one given process, as well as the processes that are missing and/or uncertain. We complement this with a comprehensive review of individual TBMs, marking the differences, uniqueness, and recent and planned developments. To conclude, we summarize the latest results in benchmarking activities, particularly as linked to recent model intercomparison projects, and outline a path forward to reducing uncertainty in the contribution of the terrestrial biosphere to global atmospheric change.
Beneath Our Feet: Strategies for Locomotion in Granular Media
Authors: Hosoi A.E. , Goldman Daniel I.
Published: September 2014

“If you find yourself in a hole, stop digging.” Although Denis Healey's famous adage ( Metcalfe 2007 ) may offer sound advice for politicians, it is less relevant to worms, clams, and other higher organisms that rely on their digging ability for survival. In this article, we review recent work on the development of simple models that elucidate the fundamental principles underlying digging and burrowing strategies employed by biological systems. Four digging regimes are identified based on dimensionless digger size and the dimensionless inertial number. We select biological organisms to represent three of the four regimes: razor clams, sandfish, and nematodes. Models for all three diggers are derived and discussed, and analogies are drawn to low–Reynolds number swimmers.
Pilot-Wave Hydrodynamics
Authors: Bush John W.M.
Published: September 2014

Yves Couder, Emmanuel Fort, and coworkers recently discovered that a millimetric droplet sustained on the surface of a vibrating fluid bath may self-propel through a resonant interaction with its own wave field. This article reviews experimental evidence indicating that the walking droplets exhibit certain features previously thought to be exclusive to the microscopic, quantum realm. It then reviews theoretical descriptions of this hydrodynamic pilot-wave system that yield insight into the origins of its quantum-like behavior. Quantization arises from the dynamic constraint imposed on the droplet by its pilot-wave field, and multimodal statistics appear to be a feature of chaotic pilot-wave dynamics. I attempt to assess the potential and limitations of this hydrodynamic system as a quantum analog. This fluid system is compared to quantum pilot-wave theories, shown to be markedly different from Bohmian mechanics and more closely related to de Broglie's original conception of quantum dynamics, his double-solution theory, and its relatively recent extensions through researchers in stochastic electrodynamics.
Fluid Mechanics of Blood Clot Formation
Authors: Fogelson Aaron L. , Neeves Keith B.
Published: September 2014

Intravascular blood clots form in an environment in which hydrodynamic forces dominate and in which fluid-mediated transport is the primary means of moving material. The clotting system has evolved to exploit fluid dynamic mechanisms and to overcome fluid dynamic challenges to ensure that clots that preserve vascular integrity can form over the wide range of flow conditions found in the circulation. Fluid-mediated interactions between the many large deformable red blood cells and the few small rigid platelets lead to high platelet concentrations near vessel walls where platelets contribute to clotting. Receptor-ligand pairs with diverse kinetic and mechanical characteristics work synergistically to arrest rapidly flowing cells on an injured vessel. Variations in hydrodynamic stresses switch on and off the function of key clotting polymers. Protein transport to, from, and within a developing clot determines whether and how fast it grows. We review ongoing experimental and modeling research to understand these and related phenomena.
Generation of Microbubbles with Applications to Industry and Medicine
Authors: Rodríguez-Rodríguez Javier , Sevilla Alejandro , Martínez-Bazán Carlos , Gordillo José Manuel
Published: September 2014

We provide a comprehensive and systematic description of the diverse microbubble generation methods recently developed to satisfy emerging technological, pharmaceutical, and medical demands. We first introduce a theoretical framework unifying the physics of bubble formation in the wide variety of existing types of generators. These devices are then classified according to the way the bubbling process is controlled: outer liquid flows (e.g., coflows, cross flows, and flow-focusing flows), acoustic forcing, and electric fields. We also address modern techniques developed to produce bubbles coated with surfactants and liquid shells. The stringent requirements to precisely control the bubbling frequency, the bubble size, and the properties of the coating make microfluidics the natural choice to implement such techniques.