bluuebunny/crossref_metadata_2025 huggingface dataset:
Nonenzymatic Template-Directed RNA Synthesis Inside Model Protocells
Authors: Adamala Katarzyna , Szostak Jack W.
Published: November 2013

Protecting Self-Replicating RNA?

The potential for self-replication makes RNA an attractive candidate as a primordial catalysis in the origin of life. Catalysis may have occurred in some kind of compartment, possibly a fatty acid vesicle. However, RNA catalysis generally requires high levels of magnesium, which are incompatible with fatty acid vesicle integrity.
Adamala and Szostak
(p.
1098
) screened magnesium chelators and found that several—including citrate, isocitrate, and oxalate—could maintain the membrane stability of fatty acid vesicles in the presence of Mg
2+
. Citrate also allowed Mg
2+
-dependent RNA synthesis within protocell-like vesicles, while at the same time protecting RNA from Mg
2+
-catalyzed degradation.
27-Hydroxycholesterol Links Hypercholesterolemia and Breast Cancer Pathophysiology
Authors: Nelson Erik R. , Wardell Suzanne E. , Jasper Jeff S. , Park Sunghee , Suchindran Sunil , Howe Matthew K. , Carver Nicole J. , Pillai Ruchita V. , Sullivan Patrick M. , Sondhi Varun , Umetani Michihisa , Geradts Joseph , McDonnell Donald P.
Published: November 2013

Cholesterol and Cancer

Obesity and high cholesterol levels are associated with an increased risk of breast cancer in post-menopausal women.

Nelson
et al.

(p.
1094
) found that a specific metabolite of cholesterol, 27-hydroxycholesterol (27HC), promoted tumor growth and metastasis in mouse models of mammary cancer by serving as a partial agonist for the estrogen receptor and the liver X receptor. The most aggressive human breast cancers were found to express the highest level of the enzyme that converts cholesterol to 27HC, suggesting that 27HC produced within tumors (in addition to circulating 27HC) may contribute to tumorigenesis.
Phycobilisomes Supply Excitations to Both Photosystems in a Megacomplex in Cyanobacteria
Authors: Liu Haijun , Zhang Hao , Niedzwiedzki Dariusz M. , Prado Mindy , He Guannan , Gross Michael L. , Blankenship Robert E.
Published: November 2013

Complexing Photosynthesis

Photosynthesis operates through a series of protein complexes that harvest sunlight and turn it into chemical energy. The separate complexes—including photosystems I and II, phycobilisome antennae, and reaction centers—are understood for a number of photosynthetic organisms; however, the large-scale organization and interactions between them are less clear. Using protein cross-linking,

Liu
et al.

(p.
1104
) demonstrate how the individual components are organized when present as a megacomplex in the cyanobacterium
Synechocystis
PCC 6803. Time-resolved fluorescence spectroscopy indicated that the phycobilisomes transfer energy to both photosystems, which is consistent with their molecular arrangement.
Hepatitis C Virus E2 Envelope Glycoprotein Core Structure
Authors: Kong Leopold , Giang Erick , Nieusma Travis , Kadam Rameshwar U. , Cogburn Kristin E. , Hua Yuanzi , Dai Xiaoping , Stanfield Robyn L. , Burton Dennis R. , Ward Andrew B. , Wilson Ian A. , Law Mansun
Published: November 2013

Deciphering Hepatitis C

Hepatitis C virus is a major cause of liver disease and cancer. Two envelope glycoproteins, E1 and E2, form a heterodimer that facilitates infection. The envelope proteins have been difficult to crystallize, hindering vaccine development.

Kong
et al.

(p.
1090
) designed an E2 core glycoprotein construct and solved the crystal structure of the glycosylated protein in complex with a broadly neutralizing antibody. The host cell receptor binding site was identified by electron microscopy and mutagenesis. The findings should help in future drug and vaccine design.
Neural Activity in Human Hippocampal Formation Reveals the Spatial Context of Retrieved Memories
Authors: Miller Jonathan F. , Neufang Markus , Solway Alec , Brandt Armin , Trippel Michael , Mader Irina , Hefft Stefan , Merkow Max , Polyn Sean M. , Jacobs Joshua , Kahana Michael J. , Schulze-Bonhage Andreas
Published: November 2013

Remembrance of Places Past

The hippocampus has two major roles in cognition. Place-responsive neurons form a context-sensitive cognitive map, firing more strongly when an animal traverses specific regions of its environment. Both humans and animals thus need the hippocampus to learn their way around novel environments. Similarly, the hippocampus is critical for our ability to remember a specific event in space and time. It has thus been suggested that the spatial and memory functions of the hippocampus reflect a common architecture. Recording from neurosurgical patients playing a virtual reality memory game,

Miller
et al.

(p.
1111
) found that the recall of events was indeed associated with reinstatement of the place-firing of neurons activated as the subjects navigated through the environment.
Clues to Supertyphoon's Ferocity Found in the Western Pacific
Authors: Normile Dennis
Published: November 2013

Unusually warm subsurface Pacific waters appear to have endowed Haiyan with the energy that made it the strongest typhoon ever known to make landfall.
Cholesterol Forges Link Between Obesity and Breast Cancer
Authors: Kaiser Jocelyn
Published: November 2013

A metabolite of cholesterol may spur the development of breast cancer, according to two new studies.
DARPA Aims to Rebuild Brains
Authors: Underwood Emily
Published: November 2013

In an interview with
Science
, Geoffrey Ling, deputy director of the Defense Sciences Office for the Defense Advanced Research Projects Agency, describes the agency's plan for participating in the Brain Research through Advancing Innovative Neurotechnologies Initiative, focusing on new technologies for curing neurological disorders and restoring memory.
Tense Vigil in China as Nasty Flu Virus Stirs Back to Life
Authors: Larson Christina
Published: November 2013

A deadly H7N9 avian flu strain is back, with four human cases in southern China in the past month. More cases are a certainty, and researchers, public health experts, and vaccinemakers are preparing for the remote but real possibility that H7N9 will explode into a pandemic.
China's Publication Bazaar
Authors: Hvistendahl Mara
Published: November 2013

A
Science
investigation has uncovered a smorgasbord of questionable practices including paying for author's slots on papers written by other scientists and buying papers from online brokers.
An Aura of Legitimacy
Authors: Hvistendahl Mara
Published: November 2013

China's paper-selling agencies mimic legitimate services that help scientists struggling with English.
Exome Sequencing in Today's Lab: Shifting the Paradigm in Translational and Clinical Research
Authors: Marshall Christian , Gilissen Christian
Published: November 2013

Next generation sequencing technologies have enabled a rapid expansion toward the understanding of inherited disorders, cancer biology, drug development, and treatment resistance. Exome sequencing has been increasingly and successfully applied in the clinical research setting for identifying common single nucleotide variants, copy number variations, and small insertions or deletions as well as rare de novo mutations that may explain Mendelian, complex, and rare genetic disorders. Recent advancement in rapid and low-cost exome sequencing make it an attractive alternative to traditional targeted gene panel sequencing for clinical research, while maintaining the possibility of discovering mutations in genes previously not associated with a disorder. Furthermore, the exome encompasses approximately 1% of the genome, yet contains approximately 85% of disease-causing mutations, making exome sequencing easier and cheaper than whole genome sequencing for identifying disease-causing variants in research.

Researchers are now applying proband-father-mother (trio) exome sequencing to uncover variants that potentially either cause or modify the condition under study. In this webinar, the audience will learn about the current applications of exome sequencing in clinical research and its impact on the future of health care.
Draft Genome Sequences of Multidrug-Resistant
Acinetobacter
sp. Strains from Colombian Hospitals
Authors: Barreto-Hernández Emiliano , Falquet Laurent , Reguero María T. , Mantilla José R. , Valenzuela Emilia M. , González Elsa , Cepeda Alexandra , Escalante Andrea
Published: November 2013

The draft genome sequences of the strains
Acinetobacter baumannii
107m,
Acinetobacter nosocomialis
28F, and
Acinetobacter pittii
42F, isolated from Colombian hospitals, are reported here. These isolates are causative of nosocomial infections and are classified as multidrug resistant, as they showed resistance to four different antibiotic groups.
First Complete Sequence of a Giant Linear Plasmid from a
Micrococcus
Strain Isolated from an Extremely High-Altitude Lake
Authors: Dib Julián Rafael , Schuldes Jörg , Thürmer Andrea , Farias María E. , Daniel Rolf , Meinhardt Friedhelm
Published: November 2013

Micrococcus
sp. strain V7, an actinobacterial strain adapted to the extreme conditions of the Laguna Vilama, an extremely high-altitude (4,600 m above sea level) lake in the Argentinian Puna, was found to carry the giant linear plasmid pLMV7. We determined its sequence (92,815 bp) as a prerequisite to the investigation of its role in survival in such a harsh environment.
Rapid Detection of Hepatitis B Virus Variants Associated with Lamivudine and Adefovir Resistance by Multiplex Ligation-Dependent Probe Amplification Combined with Real-Time PCR
Authors: Jia Shuangrong , Wang Feng , Li Fake , Chang Kai , Yang Shaojun , Zhang Kejun , Jiang Wenbin , Shang Ya , Deng Shaoli , Chen Ming
Published: November 2013

Drug-resistant mutations of hepatitis B virus (HBV) are the major obstacles to successful therapy for chronic hepatitis B infection. Although there are many methods for detecting the antiviral drug-resistant mutations of HBV, their applications are restricted because of their shortcomings, such as low sensitivity, the time required, and the high cost. For this study, a multiplex ligation-dependent probe real-time PCR (MLP-RT-PCR) method was developed to simultaneously detect lamivudine (LAM)- and adefovir (ADV)-resistant HBV mutants (those with the mutations rtM204V/I, rtA181V/T, and rtN236T). The new method combined the high-throughput nature of multiplex ligation-dependent probe amplification (MLPA) with the rapid and sensitive detection of real-time PCR. In this report, MLP-RT-PCR was evaluated by detecting drug-resistant mutants in 116 patients with chronic hepatitis B infection. By MLP-RT-PCR analysis, LAM-resistant mutations were detected in 41 patients (35.3%), ADV-resistant mutations were detected in 17 patients (14.7%), and LAM- and-ADV-resistant mutations were detected in 5 patients (4.3%). Based on the results of MLP-RT-PCR, the mutations rtM204V, rtM204I, rtA181T, rtA181V, and rtN236T were 95.7% (111/116 patients), 98.3% (114/116 patients), 99.1% (115/116 patients), 98.3% (114/116 patients), and 99.1% (115/116 patients) concordant, respectively, with those of direct sequencing. The MLP-RT-PCR assay was more sensitive than direct sequencing for detecting mutations with low frequencies. Four samples containing the low-frequency (<10%) mutants were identified by MLP-RT-PCR and further confirmed by clonal sequencing. MLP-RT-PCR is a rapid and sensitive method that enables the detection of multidrug-resistant HBV mutations in clinical practice.
Early Kinetics of Plasma Cytomegalovirus DNA Load in Allogeneic Stem Cell Transplant Recipients in the Era of Highly Sensitive Real-Time PCR Assays: Does It Have Any Clinical Value?
Authors: Giménez Estela , Muñoz-Cobo Beatriz , Solano Carlos , Amat Paula , Navarro David
Published: November 2013

We report that in a population of allogeneic stem cell transplant recipients, determination of the viral doubling time (dt) of the cytomegalovirus (CMV) DNA plasma load predicted the eventual need for inception of preemptive antiviral therapy, whereas the level of the initial plasma CMV DNA load did not. The data thus indicated that determination of the dt of CMV DNA may be useful in the therapeutic management of CMV infection in this clinical setting.
Characterization of Streptococcus tigurinus Small-Colony Variants Causing Prosthetic Joint Infection by Comparative Whole-Genome Analyses
Authors: Zbinden Andrea , Quiblier Chantal , Hernandez David , Herzog Kathrin , Bodler Paul , Senn Maria M. , Gizard Yann , Schrenzel Jacques , François Patrice
Published: November 2013

Small-colony variants (SCVs) of bacteria are associated with recurrent and persistent infections. We describe for the first time SCVs ofStreptococcus tigurinusin a patient with a prosthetic joint infection.S. tigurinusis a novel pathogen of theStreptococcus mitisgroup and causes invasive infections. We sought to characterizeS. tigurinusSCVs using experimental methods and find possible genetic explanations for their phenotypes. TheS. tigurinusSCVs were compared with the wild-type (WT) isolate using phenotypic methods, including growth under different conditions, autolysis, and visualization of the cell ultrastructure by use of transmission electron microscopy (TEM). Furthermore, comparative genome analyses were performed. TheS. tigurinusSCVs displayed reduced growth compared to the WT and showed either a very stable or a fluctuating SCV phenotype. TEM analyses revealed major alterations in cell separation and morphological abnormalities, which were partially explained by impaired autolytic behavior. Intriguingly, the SCVs were more resistant to induced autolysis. Whole-genome sequencing revealed mutations in the genes involved in general cell metabolism, cell division, stringent response, and virulence. Clinically, the patient recovered after a 2-stage exchange of the prosthesis. Comparative whole-genome sequencing in clinical strains is a useful tool for identifying novel genetic signatures leading to the most persistent bacterial forms. The detection of viridans streptococcal SCVs is challenging in a clinical laboratory due to the small colony size. Thus, it is of major clinical importance for microbiologists and clinicians to be aware of viridans streptococcal SCVs, such as those ofS. tigurinus, which lead to difficult-to-treat infections.
Nucleophosmin Contributes to the Transcriptional Activation Function of the Epstein-Barr Virus EBNA1 Protein
Authors: Malik-Soni Natasha , Frappier Lori
Published: November 2013

The Epstein-Barr virus (EBV) EBNA1 protein plays important roles in latent infection, including transcriptional activation of EBV latency genes by binding to the family-of-repeats (FR) element. Through a proteomic approach, we previously identified an interaction between EBNA1 and the histone chaperone nucleophosmin. Here we show that the EBNA1-nucleophosmin interaction is direct and requires the Gly-Arg-rich sequences that contribute to transactivation. Additionally, nucleophosmin is recruited by EBNA1 to the FR element and is required for EBNA1-mediated transcriptional activation.
Evidence of Pervasive Biologically Functional Secondary Structures within the Genomes of Eukaryotic Single-Stranded DNA Viruses
Authors: Muhire Brejnev Muhizi , Golden Michael , Murrell Ben , Lefeuvre Pierre , Lett Jean-Michel , Gray Alistair , Poon Art Y. F. , Ngandu Nobubelo Kwanele , Semegni Yves , Tanov Emil Pavlov , Monjane Adérito Luis , Harkins Gordon William , Varsani Arvind , Shepherd Dionne Natalie , Martin Darren Patrick
Published: November 2013

Single-stranded DNA (ssDNA) viruses have genomes that are potentially capable of forming complex secondary structures through Watson-Crick base pairing between their constituent nucleotides. A few of the structural elements formed by such base pairings are, in fact, known to have important functions during the replication of many ssDNA viruses. Unknown, however, are (i) whether numerous additional ssDNA virus genomic structural elements predicted to exist by computational DNA folding methods actually exist and (ii) whether those structures that do exist have any biological relevance. We therefore computationally inferred lists of the most evolutionarily conserved structures within a diverse selection of animal- and plant-infecting ssDNA viruses drawn from the families
Circoviridae
,
Anelloviridae
,
Parvoviridae
,
Nanoviridae
, and
Geminiviridae
and analyzed these for evidence of natural selection favoring the maintenance of these structures. While we find evidence that is consistent with purifying selection being stronger at nucleotide sites that are predicted to be base paired than at sites predicted to be unpaired, we also find strong associations between sites that are predicted to pair with one another and site pairs that are apparently coevolving in a complementary fashion. Collectively, these results indicate that natural selection actively preserves much of the pervasive secondary structure that is evident within eukaryote-infecting ssDNA virus genomes and, therefore, that much of this structure is biologically functional. Lastly, we provide examples of various highly conserved but completely uncharacterized structural elements that likely have important functions within some of the ssDNA virus genomes analyzed here.
Antigenic Properties of the HIV Envelope on Virions in Solution
Authors: Ray Krishanu , Mengistu Meron , Lewis George K. , Lakowicz Joseph R. , DeVico Anthony L.
Published: November 2013

The structural flexibility found in human immunodeficiency virus (HIV) envelope glycoproteins creates a complex relationship between antigenicity and sensitivity to antiviral antibodies. The study of this issue in the context of viral particles is particularly problematic as conventional virus capture approaches can perturb antigenicity profiles. Here, we employed a unique analytical system based on fluorescence correlation spectroscopy (FCS), which measures antibody-virion binding with all reactants continuously in solution. Panels of nine anti-envelope monoclonal antibodies (MAbs) and five virus types were used to connect antibody binding profiles with neutralizing activities. Anti-gp120 MAbs against the 2G12 or b12 epitope, which marks functional envelope structures, neutralized viruses expressing CCR5-tropic envelopes and exhibited efficient virion binding in solution. MAbs against CD4-induced (CD4i) epitopes considered hidden on functional envelope structures poorly bound these viruses and were not neutralizing. Anti-gp41 MAb 2F5 was neutralizing despite limited virion binding. Similar antigenicity patterns occurred on CXCR4-tropic viruses, except that anti-CD4i MAbs 17b and 19e were neutralizing despite little or no virion binding. Notably, anti-gp120 MAb PG9 and anti-gp41 MAb F240 bound to both CCR5-tropic and CXCR4-tropic viruses without exerting neutralizing activity. Differences in the virus production system altered the binding efficiencies of some antibodies but did not enhance antigenicity of aberrant gp120 structures. Of all viruses tested, only JRFL pseudoviruses showed a direct relationship between MAb binding efficiency and neutralizing potency. Collectively, these data indicate that the antigenic profiles of free HIV particles generally favor the exposure of functional over aberrant gp120 structures. However, the efficiency of virion-antibody interactions in solution inconsistently predicts neutralizing activity
in vitro
.
Mutations in the N Terminus of the øX174 DNA Pilot Protein H Confer Defects in both Assembly and Host Cell Attachment
Authors: Young Lindsey N. , Hockenberry Alyson M. , Fane Bentley A.
Published: November 2013

The øX174 DNA pilot protein H forms an oligomeric DNA-translocating tube during penetration. However, monomers are incorporated into 12 pentameric assembly intermediates, which become the capsid's icosahedral vertices. The protein's N terminus, a predicted transmembrane helix, is not represented in the crystal structure. To investigate its functions, a series of absolute and conditional lethal mutations were generated. The absolute lethal proteins, a deletion and a triple substitution, were efficiently incorporated into virus-like particles lacking infectivity. The conditional lethal mutants, bearing cold-sensitive (
cs
) and temperature-sensitive (
ts
) point mutations, were more amenable to further analyses. Viable particles containing the mutant protein can be generated at the permissive temperature and subsequently analyzed at the restrictive temperature. The characterized
cs
defect directly affected host cell attachment. In contrast,
ts
defects were manifested during morphogenesis. Particles synthesized at permissive temperature were indistinguishable from wild-type particles in their ability to recognize host cells and deliver DNA. One mutation conferred an atypical
ts
synthesis phenotype. Although the mutant protein was efficiently incorporated into virus-like particles at elevated temperature, the progeny appeared to be kinetically trapped in a temperature-independent, uninfectious state. Thus, substitutions in the N terminus can lead to H protein misincorporation, albeit at wild-type levels, and subsequently affect particle function. All mutants exhibited recessive phenotypes, i.e., rescued by the presence of the wild-type H protein. Thus, mixed H protein oligomers are functional during DNA delivery. Recessive and dominant phenotypes may temporally approximate H protein functions, occurring before or after oligomerization has gone to completion.
Splenectomy complicated by sustained extreme thrombocytosis and extensive portosplenomesenteric vein thrombosis in pyrimidine 5′-nucleotidase deficiency
Authors: Al-Jafar Hassan A , Taqi Ali , Madda John Patrick , Abdullah Thamer A
Published: November 2013

Reactive and redistributional thrombocytosis is a well-known postsplenectomy occurrence .Usually it is transient and it rarely reaches extreme levels. We report a rare case of haemolytic anaemia where splenectomy was carried out following trauma to a massively enlarged spleen and was followed by extreme sustained thrombocytosis associated with extensive portal, splenic and mesenteric vein thrombosis despite standard antithrombotic prophylaxis.
Hygroma in a 23-year-old man
Authors: Bussink Barbara Elizabeth , van Ginhoven Tessa Malaika , Smit Pieter Casper
Published: November 2013

We describe a 23-year-old man with a cystic hygroma on the right side of his lower neck. Cystic hygromas are uncommon congenital lesions of the lymphatic system and are often diagnosed before the age of 2. The finding of a cystic hygroma is rare in adults. We report the results regarding a cystic hygroma in a 23-year-old man. An initial physical examination was performed, followed by an ultrasound examination and CT. Surgical excision was the treatment of choice. Adequate imaging and physical examination of lateral neck masses in adults are needed to confirm the diagnosis.
The development of Fournier's gangrene following rubber band ligation of haemorrhoids
Authors: Subramaniam Daryl , Hureibi Khalid , Zia Khawaja , Uheba Mokthar
Published: November 2013

The development of Fournier's gangrene in an 80-year-old male patient with diabetes after a routine outpatient haemorrhoid banding procedure is described. Four days following the procedure, the patient noticed an increasing amount of pain and swelling of the perianal region. When the patient presented to the emergency department 18 days later, immediate radical debridement of ischiorectal necrotic tissue was performed. A defunctioning loop sigmoid colostomy was also formed. Subsequent operations required excision of the scrotum and abdominoperineal excision of the rectum. Histology studies later confirmed the presence of necrotising fasciitis. The case acts as a reminder that clinicians should maintain a high index of suspicion for high-risk patients still suffering from problems following the procedure.
Baboon syndrome: an unusual complication arising from antibiotic treatment of tonsillitis and review of the literature
Authors: Blackmur James Peter , Lammy Simon , Baring David E C
Published: November 2013

A 40-year-old man presented with sore throat and fevers associated with bilaterally enlarged and inflamed tonsils. A clinical diagnosis of tonsillitis was made and the patient received intravenous benzylpenicillin. Over subsequent days, the patient developed a macular rash over both groins, buttocks and axillae, with necrotic patches in the groins. An assumptive diagnosis of necrotising fasciitis was made. The patient underwent urgent groin biopsy and was started on broad spectrum antibiotics. No organisms were seen on Gram stain. Following a multidisciplinary discussion, the patient was diagnosed with baboon syndrome (symmetrical drug-related intertriginous and flexural exanthema). He was treated with oral steroid along with topical agents. Baboon syndrome can develop following penicillin administration. Given the widespread use of penicillin antibiotics to treat tonsillitis and many other conditions, it is important that medical staff recognise the side effects of these medications.
Patellofemoral osteoarthritis is prevalent and associated with worse symptoms and function after hamstring tendon autograft ACL reconstruction
Authors: Culvenor Adam G , Lai Courtney C H , Gabbe Belinda J , Makdissi Michael , Collins Natalie J , Vicenzino Bill , Morris Hayden G , Crossley Kay M
Published: November 2013

Objectives

To evaluate the compartmental distribution of knee osteoarthritis (OA) after anterior cruciate ligament reconstruction (ACLR), to determine if patellofemoral or tibiofemoral OA is more strongly associated with knee symptoms and function, and to evaluate the contribution of associated injuries and surgical delay to the development of OA.

Methods

This cross-sectional study recruited 70 participants who underwent hamstring tendon (HT) ACLR 5–10 years previously. Radiographic OA was assessed according to the Osteoarthritis Research Society International (OARSI) criteria. Knee symptoms were assessed with the Knee Injury and Osteoarthritis Outcome Score (KOOS) and Anterior Knee Pain Scale (AKPS), while function was assessed with three lower limb tasks (hop-for-distance, one-leg rise and side-hop). Multivariate and binary logistic regression analyses were performed to assess the relationship between OA and symptomatic/functional outcomes and associated injuries/surgical delay, respectively.

Results

Radiographic OA was observed in the patellofemoral (47%) and tibiofemoral joints (31%). Pain, symptoms and quality of life on the KOOS and the AKPS were associated with severity of patellofemoral OA (standardised regression coefficient (β)=−0.3 to −0.5, p=0.001–0.042), whereas only the KOOS-pain subscale was associated with tibiofemoral OA (β=−0.3, p=0.037). For each functional task, greater patellofemoral OA severity was associated with worse performance, independent of tibiofemoral OA severity (β=−0.3 to −0.4, p=0.001–0.026). Medial meniscal and patellofemoral chondral lesions at surgery were associated with tibiofemoral and patellofemoral OA development at follow-up, respectively, while a longer surgery delay was associated with patellofemoral OA.

Conclusions

Patellofemoral OA is common following HT ACLR and is associated with worse knee-related symptoms, including anterior knee pain, and decreased functional performance.
The UK Freedom of Information Act (2000) in healthcare research: a systematic review
Authors: Fowler Alexander J , Agha Riaz A , Camm Christian F , Littlejohns Peter
Published: November 2013

Objectives

To assess the use and utility of the Freedom of Information Act (2000) in healthcare research since 2005 and to determine if any particular feature of studies found led to greater data acquisition.

Design

PRISMA compliant systematic review.

Participants

An extensive literature search was performed of EMBASE, MEDLINE, CINAHL, psychINFO, BNI, AMED, HMIC and Health business elite databases from January 2005 to January 2013 using terms ‘Freedom of information’, ‘Freedom of information act’ and ‘Freedom of information act 2000’. Papers were considered for publication if they described utilising the UK Freedom of information act to gather data for healthcare research. 16 articles met these criteria.

Primary and Secondary outcome measures

Primary outcome was the number and characteristics of studies utilising the Freedom of Information Act to collect the data for healthcare research. Secondary outcome measures were any features that improved data acquisition rates (including to whom the request was made, the number of questions asked per request, etc.)

Results

16 articles described utilising the Freedom of Information Act for healthcare research, and these investigated a broad range of topics. The median number of requests made was 86 (range 1–172), the total number of requests was 1732. A total of 15 817 pieces of data were retrieved by all studies. The amount of data collected was defined as the number of questions asked multiplied by the number of full responses. A median of five questions were asked per study (range 5–6.5) and the overall response rate was 86%. The National Health Service litigation authority responded to 100% of requests, while Primary Care Trusts had the lowest response rate of 81% for healthcare bodies. A positive correlation between number of requests made and data obtained (0.508, p<0.05) and number of requests made and increased response rate (0.737, p<0.01), both reached the statistical significance.

Conclusions

Researchers should make greater use of the Act to access the information they need that is not otherwise disclosed. We discuss the issues with the research utilising the Act and how future research of this type could be optimised.
Understanding the investigators: a qualitative study investigating the barriers and enablers to the implementation of local investigator-initiated clinical trials in Ethiopia
Authors: Franzen Samuel R P , Chandler Clare , Enquselassie Fikre , Siribaddana Sisira , Atashili Julius , Angus Brian , Lang Trudie
Published: November 2013

Objectives

Clinical trials provide ‘gold standard’ evidence for policy, but insufficient locally relevant trials are conducted in low-income and middle-income countries. Local investigator-initiated trials could generate highly relevant data for national governments, but information is lacking on how to facilitate them. We aimed to identify barriers and enablers to investigator-initiated trials in Ethiopia to inform and direct capacity strengthening initiatives.

Design

Exploratory, qualitative study comprising of in-depth interviews (n=7) and focus group discussions (n=3).

Setting

Fieldwork took place in Ethiopia during March 2011.

Participants

Local health researchers with previous experiences of clinical trials or stakeholders with an interest in trials were recruited through snowball sampling (n=20).

Outcome measures

Detailed discussion notes were analysed using thematic coding analysis and key themes were identified.

Results

All participants perceived investigator-initiated trials as important for generating local evidence. System and organisational barriers included: limited funding allocation, weak regulatory and administrative systems, few learning opportunities, limited human and material capacity and poor incentives for conducting research. Operational hurdles were symptomatic of these barriers. Lack of awareness, confidence and motivation to undertake trials were important individual barriers. Training, knowledge sharing and experience exchange were key enablers to trial conduct and collaboration was unanimously regarded as important for improving capacity.

Conclusions

Barriers to trial conduct were found at individual, operational, organisational and system levels. These findings indicate that to increase locally led trial conduct in Ethiopia, system wide changes are needed to create a more receptive and enabling research environment. Crucially, the creation of research networks between potential trial groups could provide much needed practical collaborative support through sharing of financial and project management burdens, knowledge and resources. These findings could have important implications for capacity-strengthening initiatives but further research is needed before the results can be generalised more widely.
Effects of salmon on the diet and condition of stream-resident sculpins
Authors: Swain Noel R. , Hocking Morgan D. , Harding Jennifer N. , Reynolds John D.
Published: November 2013

Pacific salmon (Oncorhynchus spp.) can subsidize freshwater food webs with marine-derived nutrients from their eggs, juveniles, and carcasses. However, trophic interactions between spawning salmon and freshwater fish across natural gradients in salmon subsidies remain unclear. We tested how salmon affected the diets and condition of two dominant freshwater consumers — prickly and coastrange sculpins (Cottus asper and Cottus aleuticus, respectively) — across a wide gradient of pink salmon (Oncorhynchus gorbuscha) and chum salmon (Oncorhynchus keta) biomass from 33 streams in the Great Bear Rainforest of British Columbia, Canada. Sculpin diets shifted from invertebrates and juvenile salmonids to salmon eggs when salmon arrived in autumn, with salmon-derived nutrient contributions to diets and sculpin condition increasing with increasing biomass of spawning salmon among streams. Season, habitat, and individual sculpin body size and species also mediated the effects of salmon on sculpin diet as inferred from their carbon and nitrogen stable isotope signatures. This study shows the timing and pathways by which spawning salmon influence the diets and condition of freshwater consumers, and some of the individual and environmental factors that can regulate uptake of salmon nutrients in streams, thus informing ecosystem-based management.
An inertia-based theoretical study of the Debye shielding in different plasma configurations
Authors: Goutam H.P. , Karmakar P.K.
Published: November 2013

The Debye shielding (DS) process is studied in diverse planar plasma configurations depending on the inertial response of the plasma species within the framework of the nonlinear electrostatic Poisson formalism. It is centered on a mathematical technique specifically developed without using any conventional linearization assumption. Analytical, graphical, and numerical methodologies are adopted to characterize the DS scales, screened potentials, and associated densities without any conventional approximation in different situations. The inertial effects of the plasma constituents on the shielding processes are specifically discussed on a comparative footing. Relevant results and future directions of interdisciplinary significance relative to the realistic mean spherical approximation are highlighted.
Application of compound blue for white OLED
Authors: Zhang T. , He S.J. , Wang D.K. , Jiang N. , Lu Z.H.
Published: November 2013

Used as a blue emitter, fluorescent dye 4,4′-bis(9-ethyl-3-carbazovinylene)-1,1′-biphenyl (BCzVBi) is compounded with Bis[2-(2-hydroxyphenyl)-pyridine]beryllium(Bepp2) to yield high efficiency. When combined with green and red phosphorescent emitting layers, a broad band white light organic light-emitting diodes are obtained and studied. In this device, both singlet and triplet excitons can be harvested to generate white color. Through device structure optimization, a high efficiency of 20.8 cd/A, which corresponds to an external quantum efficiency of 11.3% has been achieved.
AN ANALYTIC APPROACH TO THE STRATIFIED MORSE INEQUALITIES FOR COMPLEX CONES
Authors: LUDWIG URSULA
Published: November 2013

In a previous paper the author extended the Witten deformation to singular spaces with cone-like singularities and to a class of Morse functions called admissible Morse functions. The method applies in particular to complex cones and stratified Morse functions in the sense of the theory developed by Goresky and MacPherson. It is well-known from stratified Morse theory that the singular points of the complex cone contribute to the stratified Morse inequalities in middle degree only. In this paper, an analytic proof of this fact is given.
APPROXIMATION OF HOLOMORPHIC MAPPINGS ON 1-CONVEX DOMAINS
Authors: STOPAR KRIS
Published: November 2013

Let π : Z → X be a holomorphic submersion of a complex manifold Z onto a complex manifold X and D ⋐ X a 1-convex domain with strongly pseudoconvex boundary. We prove that under certain conditions there always exists a spray of π-sections over [Formula: see text] which has prescribed core, it fixes the exceptional set E of D, and is dominating on [Formula: see text]. Each section in this spray is of class [Formula: see text] and holomorphic on D. As a consequence we obtain several approximation results for π-sections. In particular, we prove that π-sections which are of class [Formula: see text] and holomorphic on D can be approximated in the [Formula: see text] topology by π-sections that are holomorphic in open neighborhoods of [Formula: see text]. Under additional assumptions on the submersion we also get approximation by global holomorphic π-sections and the Oka principle over 1-convex manifolds. We include an application to the construction of proper holomorphic maps of 1-convex domains into q-convex manifolds.
AN ELECTROSTATIC DEPICTION OF THE VALIDITY OF THE RIEMANN HYPOTHESIS AND A FORMULA FOR THE NTH ZERO AT LARGE N
Authors: LECLAIR ANDRÉ
Published: November 2013

We construct a vector field E from the real and imaginary parts of an entire function ξ(z) which arises in the quantum statistical mechanics of relativistic gases when the spatial dimension d is analytically continued into the complex z plane. This function is built from the Γ and Riemann ζ functions and is known to satisfy the functional identity ξ(z) = ξ(1-z). E satisfies the conditions for a static electric field. The structure of E in the critical strip is determined by its behavior near the Riemann zeros on the critical line ℜ(z) = 1/2, where each zero can be assigned a ⊕ or ⊖ parity, or vorticity, of a related pseudo-magnetic field. Using these properties, we show that a hypothetical Riemann zero that is off the critical line leads to a frustration of this "electric" field. We formulate this frustration more precisely in terms of the potential Φ satisfying E = -∇Φ and construct Φ explicitly. The main outcome of our analysis is a formula for the nth zero on the critical line for large n expressed as the solution of a simple transcendental equation. Riemann's counting formula for the number of zeros on the entire critical strip can be derived from this formula. Our result is much stronger than Riemann's counting formula, since it provides an estimate of the nth zero along the critical line. This provides a simple way to estimate very high zeros to very good accuracy, and we estimate the 10106-th one.
CUBULATED MOVES AND DISCRETE KNOTS
Authors: HINOJOSA GABRIELA , VERJOVSKY ALBERTO , VERJOVSKY MARCOTTE CYNTHIA
Published: November 2013

In this paper, we prove that two cubic knots K1, K2 are isotopic if and only if one can pass from one to the other by a finite sequence of cubulated moves. These moves are analogous to the Reidemeister moves for classical tame knots. We use this fact to describe a cubic knot in a discrete way, as a cyclic permutation of contiguous vertices of the ℤ3-lattice (with some restrictions); moreover, we describe a regular diagram of a cubic knot in terms of such cyclic permutations.
THE YOKONUMA–HECKE ALGEBRAS AND THE HOMFLYPT POLYNOMIAL
Authors: CHLOUVERAKI MARIA , LAMBROPOULOU SOFIA
Published: November 2013

We compare the invariants for classical knots and links defined using the Juyumaya trace on the Yokonuma–Hecke algebras with the HOMFLYPT polynomial. We show that these invariants do not coincide with the HOMFLYPT except in a few trivial cases.
A DUALITY-INVARIANT EINSTEIN–PLANCK RELATION AND ITS CONSEQUENCES ON MICRO BLACK HOLES
Authors: JOU D. , MONGIOVI M. S. , SCIACCA M.
Published: November 2013

We discuss the consequences of a duality-invariant Einstein–Planck (DIEP) relation on the equation of state of micro black holes. The results are analogous to those obtained from the "world-crystal" model, but with some significative differences, as for instance a limiting vanishing value for temperature for very small black holes. The model leads to a total evaporation of micro black holes but with the final stage being very slow.
HYDRODYNAMICS AT RHIC AND LHC: WHAT HAVE WE LEARNED?
Authors: HUOVINEN PASI
Published: November 2013

Fluid dynamical description of elementary particle collisions has a long history dating back to the works of Landau and Fermi. Nevertheless, it is during the last 10–15 years when fluid dynamics has become the standard tool to describe the evolution of matter created in ultrarelativistic heavy-ion collisions. In this paper, I briefly describe the hydrodynamical models, what we have learned when analyzing the RHIC and LHC data using these models, and what the latest developments and challenges are.
KEPLERIAN FREQUENCY OF UNIFORMLY ROTATING NEUTRON STARS IN RELATIVISTIC MEAN FIELD THEORY
Authors: ZHANG N. B. , QI B. , WANG S. Y. , GE S. L. , SUN B. Y.
Published: November 2013

Adopting the equation of states (EOSs) from the relativistic mean field (RMF) theory, the relationships among the keplerian frequency fK, gravitational mass M and radius R for the rapidly rotating neutron stars with and without hyperons are presented and analyzed. For various RMF EOSs, the empirical formula [Formula: see text], proposed by P. Haensel et al. [Astron. Astrophys.502 (2009) 605], is found to be an approximation with the error at most 13% and such approximation is worse for the neutron stars with hyperons. It indicates that the errors should be considered when the empirical formula is used to discuss the properties of neutron stars.
ENTREPRENEURSHIP EDUCATION: A SYSTEMATIC REVIEW OF THE METHODS IN IMPACT STUDIES
Authors: LORZ MICHAEL , MUELLER SUSAN , VOLERY THIERRY
Published: November 2013

The majority of studies that analyze the impact of entrepreneurship education on entrepreneurial attitudes, intentions, and venture activities report positive influences. However, several scholars have recently cast doubts about research methods and the generalizability of entrepreneurship education impact studies. In this study, we conducted a systematic literature review of the methods used in entrepreneurship education impact studies. Our results uncover significant methodological deficiencies and question the overwhelmingly positive impact of entrepreneurship education. Based on this evidence, we propose a series of recommendations to improve the reliability and validity of entrepreneurship education impact studies and we outline promising topics which are currently under-researched.
DETERMINANTS OF ENTREPRENEURIAL INTENTIONS: APPLYING WESTERN MODEL TO THE SRI LANKA CONTEXT
Authors: LIN XIAOHUA , CARSRUD ALAN , JAGODA KALINGA , SHEN WANQING
Published: November 2013

This study examines the factors influencing the intention of students to start up a new venture. Using both the "Theory of Planned Behavior" and "Theory of Reasoned Action", a model is tested using survey data collected from 353 undergraduate business students in Sri Lanka. Results of structural equation modeling show entrepreneurial intentions are positively influenced by perceived behavioral control and macro-environment support. However, the effects of attitudes towards entrepreneurship and subjective norms were not significantly related to intentions. Interestingly, beliefs about entrepreneurship had a negative relationship with attitudes toward entrepreneurship. Theoretical and practical implications of these findings are discussed in the context of developing countries like Sri Lanka.
LINKING INTERNATIONAL HIGH-TECH NEW VENTURES' FIRM LIFE CYCLE TO INTERNATIONALIZATION, ORGANIZATIONAL LEARNING, AND ALLIANCE NETWORKS
Authors: WU CHING-SUNG , HSU CHIH-SHENG
Published: November 2013

Drawing from recent research on the international new ventures' (INVs) internal and external characteristics and conditions, this article explores the trajectory of growth for high-tech INVs from firms' life cycle perspective, and examines the divergent features of INVs, including internationalization, organizational learning, and alliance network, at various stages of development. Our findings are based on information from a database covering 226 INV firms funded in the US after 1980. We suggest that INVs' features are different at various stages of their life cycle, and develop dynamically under divergent conditions.
Least energy radial sign-changing solutions for a singular elliptic equation in lower dimensions
Authors: Peng Shuangjie , Peng Yanfang
Published: November 2013

We study the following singular elliptic equation [Formula: see text] with Dirichlet boundary condition, which is related to the well-known Caffarelli–Kohn–Nirenberg inequalities. By virtue of variational method and Nehari manifold, we obtain least energy sign-changing solutions in some ranges of the parameters μ and λ. In particular, our result generalizes the existence results of sign-changing solutions to lower dimensions 5 and 6.
Nodal sets and horizontal singular sets of ℍ-harmonic functions on the Heisenberg group
Authors: Tian Long , Yang Xiaoping
Published: November 2013

In this paper, we give measure estimates of nodal sets of ℍ-harmonic functions on the Heisenberg group ℍn. We also introduce a definition of horizontal singular sets and show the geometric structure of the horizontal singular sets of ℍ-harmonic functions.
Buckling and post-buckling of size-dependent piezoelectric Timoshenko nanobeams subject to thermo-electro-mechanical loadings
Authors: Liu C. , Ke L. L. , Wang Y. S. , Yang J. , Kitipornchai S.
Published: November 2013

Buckling and post-buckling behaviors of piezoelectric nanobeams are investigated by using the nonlocal Timoshenko beam theory and von Kármán geometric nonlinearity. The piezoelectric nanobeam is subjected to an axial compression force, an applied voltage and a uniform temperature rise. After constructing the energy functionals, the nonlinear governing equations are derived by using the principle of minimum total potential energy and discretized by using the differential quadrature (DQ) method. A direct iterative method is employed to determine the buckling and post-buckling responses of piezoelectric nanobeams with hinged–hinged, clamped–hinged and clamped–clamped end conditions. Numerical examples are presented to study the influences of the nonlocal parameter, temperature rise and external electric voltage on the size-dependent buckling and post-buckling responses of piezoelectric nanobeams.
Hybrid probabilistic interval dynamic analysis of vehicle–bridge interaction system with uncertainties
Authors: Liu N. , Gao W. , Song C. , Zhang N.
Published: November 2013

This paper presents the hybrid probabilistic interval dynamic analysis of vehicle–bridge interaction system with a mixture of random and interval properties. The vehicle's parameters are considered as interval variables and the bridge's parameters are treated as random variables. A half car model is used to represent a moving vehicle and the bridge is modeled as a simply supported Euler–Bernoulli beam. By introducing the random interval moment method (RIMM) into the dynamic analysis of vehicle–bride interaction system, the expressions for the mean value and standard deviation of the random interval bridge dynamic response are developed. The midpoint and interval width of the first two statistical moments are then determined. Examples are used to illustrate the effectiveness of the presented method. A hybrid simulation method combining direct simulations for interval variables and Monte Carlo simulations for random variables is implemented to validate the computational results. The effects of individual system parameters on bridge response are also investigated.