bluuebunny/crossref_metadata_2025_split huggingface dataset:
Demonstration of photon Bloch oscillations and Wannier-Stark ladders in dual-periodical multilayer structures based on porous silicon
Authors: Estevez J Octavio , Arriaga Jesús , Mendez-Blas Antonio , Reyes-Ayona Edgar , Escorcia José , Agarwal Vivechana 
Published: July 2012

Abstract
Theoretical demonstration and experimental evidence of photon Bloch oscillations and Wannier-Stark ladders (WSLs) in dual-periodical (DP) multilayers, based on porous silicon, are presented. An introduction of the linear gradient in refractive indices in DP structure, which is composed by stacking two different periodic substructures N times, resulted in the appearance of WSLs. Theoretical time-resolved reflection spectrum shows the photon Bloch oscillations with a period of 130 fs. Depending on the values of the structural parameters, one can observe the WSLs in the near infrared or visible region which may allow the generation of terahertz radiation with a potential applications in several fields like imaging.
Strong convergence theorems for a common point of solution of variational inequality, solutions of equilibrium and fixed point problems
Authors: Zegeye Habtu , Shahzad Naseer , Alghamdi Mohammad Ali 
Published: July 2012

Abstract
We introduce an iterative process which converges strongly to a common point of solution of variational inequality problem for continuous monotone mapping, solution of equilibrium problem and a common fixed point of finite family of asymptotically regular uniformly continuous relatively asymptotically nonexpansive mappings in Banach spaces. Our scheme does not involve computation of C

n+1from C

n
for each n ≥ 1. Our theorems improve and unify most of the results that have been proved for this important class of nonlinear operators.

Mathematics Subject Classification (2000): 47H05, 47H09, 47H10, 47J05, 47J25
Force sensor in simulated skin and neural model mimic tactile SAI afferent spiking response to ramp and hold stimuli
Authors: Kim Elmer K , Wellnitz Scott A , Bourdon Sarah M , Lumpkin Ellen A , Gerling Gregory J 
Published: July 2012

Abstract

Background
The next generation of prosthetic limbs will restore sensory feedback to the nervous system by mimicking how skin mechanoreceptors, innervated by afferents, produce trains of action potentials in response to compressive stimuli. Prior work has addressed building sensors within skin substitutes for robotics, modeling skin mechanics and neural dynamics of mechanotransduction, and predicting response timing of action potentials for vibration. The effort here is unique because it accounts for skin elasticity by measuring force within simulated skin, utilizes few free model parameters for parsimony, and separates parameter fitting and model validation. Additionally, the ramp-and-hold, sustained stimuli used in this work capture the essential features of the everyday task of contacting and holding an object.

Methods
This systems integration effort computationally replicates the neural firing behavior for a slowly adapting type I (SAI) afferent in its temporally varying response to both intensity and rate of indentation force by combining a physical force sensor, housed in a skin-like substrate, with a mathematical model of neuronal spiking, the leaky integrate-and-fire. Comparison experiments were then conducted using ramp-and-hold stimuli on both the spiking-sensor model and mouse SAI afferents. The model parameters were iteratively fit against recorded SAI interspike intervals (ISI) before validating the model to assess its performance.

Results
Model-predicted spike firing compares favorably with that observed for single SAI afferents. As indentation magnitude increases (1.2, 1.3, to 1.4 mm), mean ISI decreases from 98.81 ± 24.73, 54.52 ± 6.94, to 41.11 ± 6.11 ms. Moreover, as rate of ramp-up increases, ISI during ramp-up decreases from 21.85 ± 5.33, 19.98 ± 3.10, to 15.42 ± 2.41 ms. Considering first spikes, the predicted latencies exhibited a decreasing trend as stimulus rate increased, as is observed in afferent recordings. Finally, the SAI afferent’s characteristic response of producing irregular ISIs is shown to be controllable via manipulating the output filtering from the sensor or adding stochastic noise.

Conclusions
This integrated engineering approach extends prior works focused upon neural dynamics and vibration. Future efforts will perfect measures of performance, such as first spike latency and irregular ISIs, and link the generation of characteristic features within trains of action potentials with current pulse waveforms that stimulate single action potentials at the peripheral afferent.
Isolation of a reassortant H13N2 virus from a mallard fecal sample in South Korea
Authors: Kang Hyun-Mi , Choi Jun-Gu , Kim Min-Chul , Kim Hye-Ryoung , Oem Jae-Ku , Bae You-Chan , Paek Mi-Ra , Kwon Jun-Hun , Lee Youn-Jeong 
Published: July 2012

Abstract

Background
Virus subtype H13N2, A/mallard/Kr/SH38-45/2010 (H13N2), was first isolated from a mallard fecal sample in South Korea.

Results
Phylogenetic analysis of all eight viral genes revealed that this virus emerged by genetic mixing between Eurasian and North American gene pools, and possibly between wild ducks and gulls. The H13 and N2 surface genes clustered together in a group with Eurasian isolates from gulls and wild birds, respectively. The PB2, PA, NP, M and NS segments belonged to the Eurasian lineage, whereas the PB1 gene clustered in the North American lineage. Furthermore, they showed a bird-dependent pattern in phylogenetic analysis: the M gene was similar to subtype H13 viruses within gulls, whereas other segments were similar to avian influenza viruses of other subtypes from wild ducks.

Conclusions
The data suggests that the novel reassortant H13N2 virus isolated in South Korea might have emerged by genetic reassortment between intercontinental and interspecies transmission in wild birds.
Comparison of serological assays for detecting antibodies in ducks exposed to H5 subtype avian influenza virus
Authors: Wibawa Hendra , Henning Joerg , Waluyati Dessie Eri , Usman Tri Bhakti , Lowther Sue , Bingham John , Junaidi Akhmad , Meers Joanne 
Published: July 2012

Abstract

Background
Chicken red blood cells (RBCs) are commonly used in hemagglutination inhibition (HI) tests to measure hemagglutinating antibodies against influenza viruses. The use of horse RBCs in the HI test can reportedly increase its sensitivity when testing human sera for avian influenza antibodies. This study aims to compare the proportion of positives detected and the agreement between two HI tests using either chicken or horse red blood cells for antibody detection in sera of ducks experimentally infected or naturally exposed to Indonesian H5 subtype avian influenza virus. In addition, comparison with a virus neutralisation (VN) test was conducted with the experimental sera.

Results
In the experimental study, the proportion of HI antibody-positive ducks increased slightly, from 0.57 when using chicken RBCs to 0.60 when using horse RBCs. The HI tests indicated almost perfect agreement (kappa = 0.86) when results were dichotomised (titre ≥ 4 log2), and substantial agreement (weighted kappa = 0.80) for log titres. Overall agreements between the two HI tests were greater than between either of the HI tests and the VN test. The use of horse RBCs also identified a higher proportion of antibody positives in field duck sera (0.08, compared to chicken RBCs 0.02), with also almost perfect agreements for dichotomized results (Prevalence and bias adjusted Kappa (PABAK) = 0.88) and for log titres (weighted PABAK = 0.93), respectively. Factors that might explain observed differences in the proportion of antibody-positive ducks and in the agreements between HI tests are discussed.

Conclusion
In conclusion, we identified a good agreement between HI tests. However, when horse RBCs were used, a higher proportion of sera was positive (titre ≥ 4 log2) than using chicken RBCs, especially during the early response against H5N1 virus. The HRBC-HI might be more responsive in identifying early H5N1 HPAI serological response and could be a recommended assay for avian influenza sero-surveillance in both wild and domestic birds.
The chemokine receptor cxcr5 regulates the regenerative neurogenesis response in the adult zebrafish brain
Authors: Kizil Caghan , Dudczig Stefanie , Kyritsis Nikos , Machate Anja , Blaesche Juliane , Kroehne Volker , Brand Michael 
Published: July 2012

Abstract

Background
Unlike mammals, zebrafish exhibits extensive neural regeneration after injury in adult stages of its lifetime due to the neurogenic activity of the radial glial cells. However, the genes involved in the regenerative neurogenesis response of the zebrafish brain are largely unknown. Thus, understanding the underlying principles of this regeneration capacity of the zebrafish brain is an interesting research realm that may offer vast clinical ramifications.

Results
In this paper, we characterized the expression pattern of cxcr5 and analyzed the function of this gene during adult neurogenesis and regeneration of the zebrafish telencephalon. We found that cxcr5 was upregulated transiently in the RGCs and neurons, and the expression in the immune cells such as leukocytes was negligible during both adult neurogenesis and regeneration. We observed that the transgenic misexpression of cxcr5 in the ventricular cells using dominant negative and full-length variants of the gene resulted in altered proliferation and neurogenesis response of the RGCs. When we knocked down cxcr5 using antisense morpholinos and cerebroventricular microinjection, we observed outcomes similar to the overexpression of the dominant negative cxcr5 variant.

Conclusions
Thus, based on our results, we propose that cxcr5 imposes a proliferative permissiveness to the radial glial cells and is required for differentiation of the RGCs to neurons, highlighting novel roles of cxcr5 in the nervous system of vertebrates. We therefore suggest that cxcr5 is an important cue for ventricular cell proliferation and regenerative neurogenesis in the adult zebrafish telencephalon. Further studies on the role of cxcr5 in mediating neuronal replenishment have the potential to produce clinical ramifications in efforts for regenerative therapeutic applications for human neurological disorders or acute injuries.
Synergistic influence of phosphorylation and metal ions on tau oligomer formation and coaggregation with α-synuclein at the single molecule level
Authors: Nübling Georg , Bader Benedikt , Levin Johannes , Hildebrandt Jenna , Kretzschmar Hans , Giese Armin 
Published: July 2012

Abstract

Background
Fibrillar amyloid-like deposits and co-deposits of tau and α-synuclein are found in several common neurodegenerative diseases. Recent evidence indicates that small oligomers are the most relevant toxic aggregate species. While tau fibril formation is well-characterized, factors influencing tau oligomerization and molecular interactions of tau and α-synuclein are not well understood.

Results
We used a novel approach applying confocal single-particle fluorescence to investigate the influence of tau phosphorylation and metal ions on tau oligomer formation and its coaggregation with α-synuclein at the level of individual oligomers. We show that Al3+ at physiologically relevant concentrations and tau phosphorylation by GSK-3β exert synergistic effects on the formation of a distinct SDS-resistant tau oligomer species even at nanomolar protein concentration. Moreover, tau phosphorylation and Al3+ as well as Fe3+ enhanced both formation of mixed oligomers and recruitment of α-synuclein in pre-formed tau oligomers.

Conclusions
Our findings provide a new perspective on interactions of tau phosphorylation, metal ions, and the formation of potentially toxic oligomer species, and elucidate molecular crosstalks between different aggregation pathways involved in neurodegeneration.
Multiple independent analyses reveal only transcription factors as an enriched functional class associated with microRNAs
Authors: Croft Larry , Szklarczyk Damian , Jensen Lars Juhl , Gorodkin Jan 
Published: July 2012

Abstract

Background
Transcription factors (TFs) have long been known to be principally activators of transcription in eukaryotes and prokaryotes. The growing awareness of the ubiquity of microRNAs (miRNAs) as suppressive regulators in eukaryotes, suggests the possibility of a mutual, preferential, self-regulatory connectivity between miRNAs and TFs. Here we investigate the connectivity from TFs and miRNAs to other genes and each other using text mining, TF promoter binding site and 6 different miRNA binding site prediction methods.

Results
In the first approach text mining of PubMed abstracts reveal statistically significant associations between miRNAs and both TFs and signal transduction gene classes. Secondly, prediction of miRNA targets in human and mouse 3’UTRs show enrichment only for TFs but not consistently across prediction methods for signal transduction or other gene classes. Furthermore, a random sample of 986 TarBase entries was scored for experimental evidence by manual inspection of the original papers, and enrichment for TFs was observed to increase with score. Low-scoring TarBase entries, where experimental evidence is anticorrelated miRNA:mRNA expression with predicted miRNA targets, appear not to select for real miRNA targets to any degree. Our manually validated text-mining results also suggests that miRNAs may be activated by more TFs than other classes of genes, as 7% of miRNA:TF co-occurrences in the literature were TFs activating miRNAs. This was confirmed when thirdly, we found enrichment for predicted, conserved TF binding sites in miRNA and TF genes compared to other gene classes.

Conclusions
We see enrichment of connections between miRNAs and TFs using several independent methods, suggestive of a network of mutual activating and suppressive regulation. We have also built regulatory networks (containing 2- and 3-loop motifs) for mouse and human using predicted miRNA and TF binding sites and we have developed a web server to search and display these loops, available for the community at http://rth.dk/resources/tfmirloop.
Breast systemic follicular lymphoma in a man: a case report
Authors: La Mantia Elvira , Cantile Monica , Liguori Giuseppina , Di Bonito Maurizio , De Chiara Annarosaria , D'Aiuto Massimiliano , Pannone Giuseppe , Franco Renato , Botti Gerardo 
Published: July 2012

Abstract

Introduction
Breast involvement by non-Hodgkin lymphoma is particularly rare in men. We describe the case of a patient with a rapidly growing, painless gynecomastia-like nodule in the left breast. On ultrasonography, the nodule was suspicious for breast carcinoma.

Case presentation
A breast biopsy from a 54-year-old Caucasian man showed the morphoimmunophenotypical features of grade 3 follicular lymphoma. Moreover, fluorescence in situ hybridization analysis showed a t(14,18) translocation suggesting breast involvement by a systemic lymphoma rather than a primary breast lymphoma. The histological diagnosis was subsequently confirmed after nodule excision. Mediastinal and abdominal node involvement was then identified on computed tomography and positron emission tomography scans during staging examinations. Our patient was treated with chemotherapy. After three years our patient experienced a right retro-areolar relapse. He then received two further cycles of chemotherapy but developed a myeloid acute leukemia and, as a result of this, he subsequently died.

Conclusions
The rarity of breast lymphomas, especially in men, and the problems related to the therapeutic choices with these tumors require molecular techniques in association with classical histological diagnosis.
A comparison and evaluation of five biclustering algorithms by quantifying goodness of biclusters for gene expression data
Authors: Li Li , Guo Yang , Wu Wenwu , Shi Youyi , Cheng Jian , Tao Shiheng 
Published: July 2012

Abstract

Background
Several biclustering algorithms have been proposed to identify biclusters, in which genes share similar expression patterns across a number of conditions. However, different algorithms would yield different biclusters and further lead to distinct conclusions. Therefore, some testing and comparisons between these algorithms are strongly required.

Methods
In this study, five biclustering algorithms (i.e. BIMAX, FABIA, ISA, QUBIC and SAMBA) were compared with each other in the cases where they were used to handle two expression datasets (GDS1620 and pathway) with different dimensions in Arabidopsis thaliana (A. thaliana)
GO (gene ontology) annotation and PPI (protein-protein interaction) network were used to verify the corresponding biological significance of biclusters from the five algorithms. To compare the algorithms’ performance and evaluate quality of identified biclusters, two scoring methods, namely weighted enrichment (WE) scoring and PPI scoring, were proposed in our study. For each dataset, after combining the scores of all biclusters into one unified ranking, we could evaluate the performance and behavior of the five biclustering algorithms in a better way.

Results
Both WE and PPI scoring methods has been proved effective to validate biological significance of the biclusters, and a significantly positive correlation between the two sets of scores has been tested to demonstrate the consistence of these two methods.
A comparative study of the above five algorithms has revealed that: (1) ISA is the most effective one among the five algorithms on the dataset of GDS1620 and BIMAX outperforms the other algorithms on the dataset of pathway. (2) Both ISA and BIMAX are data-dependent. The former one does not work well on the datasets with few genes, while the latter one holds well for the datasets with more conditions. (3) FABIA and QUBIC perform poorly in this study and they may be suitable to large datasets with more genes and more conditions. (4) SAMBA is also data-independent as it performs well on two given datasets. The comparison results provide useful information for researchers to choose a suitable algorithm for each given dataset.
Identity and diversity of blood meal hosts of biting midges (Diptera: Ceratopogonidae: Culicoides Latreille) in Denmark
Authors: Lassen Sandra B , Nielsen Søren Achim , Kristensen Michael 
Published: July 2012

Abstract

Background
Host preference studies in haematophagous insects e.g. Culicoides biting midges are pivotal to assess transmission routes of vector-borne diseases and critical for the development of veterinary contingency plans to identify which species should be included due to their risk potential. Species of Culicoides have been found in almost all parts of the world and known to live in a variety of habitats. Several parasites and viruses are transmitted by Culicoides biting midges including Bluetongue virus and Schmallenberg virus. The aim of the present study was to determine the identity and diversity of blood meals taken from vertebrate hosts in wild-caught Culicoides biting midges near livestock farms.

Methods
Biting midges were collected at weekly intervals for 20 weeks from May to October 2009 using light traps at four collection sites on the island Sealand, Denmark. Blood-fed female biting midges were sorted and head and wings were removed for morphological species identification. The thoraxes and abdomens including the blood meals of the individual females were subsequently subjected to DNA isolation. The molecular marker cytochrome oxidase I (COI barcode) was applied to identify the species of the collected biting midges (GenBank accessions JQ683259-JQ683374). The blood meals were first screened with a species-specific cytochrome b primer pair for cow and if negative with a universal cytochrome b primer pair followed by sequencing to identify mammal or avian blood meal hosts.

Results
Twenty-four species of biting midges were identified from the four study sites. A total of 111,356 Culicoides biting midges were collected, of which 2,164 were blood-fed. Specimens of twenty species were identified with blood in their abdomens. Blood meal sources were successfully identified by DNA sequencing from 242 (76%) out of 320 Culicoides specimens. Eight species of mammals and seven species of birds were identified as blood meal hosts. The most common host species was the cow, which constituted 77% of the identified blood meals. The second most numerous host species was the common wood pigeon, which constituted 6% of the identified blood meals.

Conclusions
Our results suggest that some Culicoides species are opportunistic and readily feed on a variety of mammals and birds, while others seems to be strictly mammalophilic or ornithophilic. Based on their number, dispersal potential and blood feeding behaviour, we conclude that Culicoides biting midges are potential vectors for many pathogens not yet introduced to Denmark.
Weight status of adolescents in secondary schools in port Harcourt using Body Mass Index (BMI)
Authors: Adesina Adesuwa F , Peterside Oliemen , Anochie Ifeoma , Akani Nwadiuto A 
Published: July 2012

AbstractBackgroundAdolescent weight status is a cumulative effect of health and nutritional problems. Adolescent weight problems often go unnoticed as weight assessment is not considered a priority in adolescents.ObjectivesTo determine the weight status of adolescents using BMI and to identify the contributing factors to adolescent weight problems.MethodsIn April 2010, 960 adolescents aged 10–19 years in secondary schools in Port Harcourt were selected for the study using a stratified multi-staged sampling method. Structured questionnaires were filled by the investigators while weight and height were measured. BMI was calculated using the formula weight/height2(kg/m2).ResultsThe prevalence of underweight, overweight, obesity and stunting were 6.4%, 6.3%, 1.8% and 5.4% respectively. Factors which were commoner in overweight adolescents were high socioeconomic class, higher maternal education, spending > 3 hours a day watching television and frequent ingestion of snacks.ConclusionThere is a need for periodic weight assessment of adolescents and health education to promote healthy eating habits and regular physical exercise as part of the School Health Programme.