bluuebunny/crossref_metadata_2025 huggingface dataset:
Slaying the Trojan Horse: Natural Killer Cells Exhibit Robust Anti-HIV-1 Antibody-Dependent Activation and Cytolysis against Allogeneic T Cells
Authors: Gooneratne Shayarana L. , Richard Jonathan , Lee Wen Shi , Finzi Andrés , Kent Stephen J. , Parsons Matthew S.
Published: October 2014

Many attempts to design prophylactic human immunodeficiency virus type 1 (HIV-1) vaccines have focused on the induction of neutralizing antibodies (Abs) that block infection by free virions. Despite the focus on viral particles, virus-infected cells, which can be found within mucosal secretions, are more infectious than free virus bothin vitroandin vivo. Furthermore, assessment of human transmission couples suggests infected seminal lymphocytes might be responsible for a proportion of HIV-1 transmissions. Although vaccines that induce neutralizing Abs are sought, only some broadly neutralizing Abs efficiently block cell-to-cell transmission of HIV-1. As HIV-1 vaccines need to elicit immune responses capable of controlling both free and cell-associated virus, we evaluated the potential of natural killer (NK) cells to respond in an Ab-dependent manner to allogeneic T cells bearing HIV-1 antigens. This study presents data measuring Ab-dependent anti-HIV-1 NK cell responses to primary and transformed allogeneic T-cell targets. We found that NK cells are robustly activated in an anti-HIV-1 Ab-dependent manner against allogeneic targets and that tested target cells are subject to Ab-dependent cytolysis. Furthermore, the educated KIR3DL1+NK cell subset from HLA-Bw4+individuals exhibits an activation advantage over the KIR3DL1−subset that contains both NK cells educated through other receptor/ligand combinations and uneducated NK cells. These results are intriguing and important for understanding the regulation of Ab-dependent NK cell responses and are potentially valuable for designing Ab-dependent therapies and/or vaccines.

IMPORTANCENK cell-mediated anti-HIV-1 antibody-dependent functions have been associated with protection from infection and disease progression; however, their role in protecting from infection with allogeneic cells infected with HIV-1 is unknown. We found that HIV-1-specific ADCC antibodies bound to allogeneic cells infected with HIV-1 or coated with HIV-1 gp120 were capable of activating NK cells and/or trigging cytolysis of the allogeneic target cells. This suggests ADCC may be able to assist in preventing infection with cell-associated HIV-1. In order to fully utilize NK cell-mediated Ab-dependent effector functions, it might also be important that educated NK cells, which hold the highest activation potential, can become activated against targets bearing HIV-1 antigens and expressing the ligands for self-inhibitory receptors. Here, we show that with Ab-dependent stimulation, NK cells expressing inhibitory receptors can mediate robust activation against targets expressing the ligands for those receptors.
Swine Interferon-Inducible Transmembrane Proteins Potently Inhibit Influenza A Virus Replication
Authors: Lanz Caroline , Yángüez Emilio , Andenmatten Dario , Stertz Silke
Published: October 2014

Human interferon-inducible transmembrane proteins (IFITMs) were identified as restriction factors of influenza A virus (IAV). Given the important role of pigs in the zoonotic cycle of IAV, we cloned swine IFITMs (swIFITMs) and found two IFITM1-like proteins, one homologue of IFITM2, and a homologue of IFITM3. We show that swIFITM2 and swIFITM3 localize to endosomes and display potent antiviral activities. Knockdown of swIFITMs strongly reduced virus inhibition by interferon, establishing the swIFITMs as potent restriction factors in porcine cells.
Kaposi's Sarcoma-Associated Herpesvirus-Encoded Replication and Transcription Activator Impairs Innate Immunity via Ubiquitin-Mediated Degradation of Myeloid Differentiation Factor 88
Authors: Zhao Qinglan , Liang Deguang , Sun Rui , Jia Baosen , Xia Tian , Xiao Hui , Lan Ke
Published: October 2014

Kaposi's sarcoma-associated herpesvirus (KSHV) is a human gammaherpesvirus with latent and lytic reactivation cycles. The mechanism by which KSHV evades the innate immune system to establish latency has not yet been precisely elucidated. Toll-like receptors (TLRs) are the first line of defense against viral infections. Myeloid differentiation factor 88 (MyD88) is a key adaptor that interacts with all TLRs except TLR3 to produce inflammatory factors and type I interferons (IFNs), which are central components of innate immunity against microbial infection. Here, we found that KSHV replication and transcription activator (RTA), which is an immediate-early master switch protein of viral cycles, downregulates MyD88 expression at the protein level by degrading MyD88 through the ubiquitin (Ub)-proteasome pathway. We identified the interaction between RTA and MyD88
in vitro
and
in vivo
and demonstrated that RTA functions as an E3 ligase to ubiquitinate MyD88. MyD88 also was repressed at the early stage of
de novo
infection as well as in lytic reactivation. We also found that RTA inhibited lipopolysaccharide (LPS)-triggered activation of the TLR4 pathway by reducing IFN production and NF-κB activity. Finally, we showed that MyD88 promoted the production of IFNs and inhibited KSHV LANA-1 gene transcription. Taken together, our results suggest that KSHV RTA facilitates the virus to evade innate immunity through the degradation of MyD88, which might be critical for viral latency control.

IMPORTANCE
MyD88 is an adaptor for all TLRs other than TLR3, and it mediates inflammatory factors and IFN production. Our study demonstrated that the KSHV RTA protein functions as an E3 ligase to degrade MyD88 through the ubiquitin-proteasome pathway and block the transmission of TLRs signals. Moreover, we found that KSHV inhibited MyD88 expression during the early stage of
de novo
infection as well as in lytic reactivation. These results provide a potential mechanism for the virus to evade innate immunity.
Tripe palm: a cutaneous manifestation of gastric carcinoma
Authors: Chakraborty Partha Pratim , Datta Saumik , Mandal Sanjay Kumar , Kumar Manoj
Published: October 2014

Case 1: A 43-year-old farmer attended our clinic with increasing fatigability, nausea, loss of appetite, loss of weight, postprandial fullness along with thyroid-stimulating hormone value of 0.4 mIU/L and anaemia without any history of cough, chest pain, haemoptysis, osmotic symptoms, haematemesis or malena. The patient received albendazole and iron preparations before attending our clinic. Case 2: A 51-year-old woman, a known patient with type 2 diabetes for the past 8 years, on gliclazide and metformin (2 g), with unaltered liver function test and renal function test, presented with symptoms similar to case 1 of upper gastrointestinal features along with a history of weight loss (about 6 kg) over the past 3 months. Metformin was withdrawn by her primary care physician but her symptoms persisted. A velvety appearance with pigmentation on the palms of the hands was found in both cases. Endoscopy revealed an irregular mass in the stomach. Subsequently, both patients were diagnosed to have gastric adenocarcinoma.
Angiomyoma presenting as a painful subcutaneous mass: a diagnostic challenge
Authors: Kumar Sandeep , Hasan Roumina , Maddukuri Satish Babu , Mathew Mary
Published: October 2014

Angiomyoma of the extremity is a notoriously elusive preoperative diagnosis, as the list of differentials for its described classic clinical features of a painful mobile subcutaneous mass is quite vast. Imaging features described for angiomyomas are far from being specific. On ultrasound, angiomyomas are mostly described as a well-defined solid mass lesion showing robust internal vascularity. On T2-weighted MRI they have been described as homogenous to heterogeneously hyperintense relative to skeletal muscle. We report a pathologically proven angiomyoma around the knee joint in a middle aged man, describe its clinical and imaging features, and outlay an approach in diagnosing this rare entity as a differential for painful subcutaneous mass lesions.
Extraskeletal osteosarcoma of the larynx: an extremely unusual tumour
Authors: Bhatt Nikita R , Kakked Gaurav A , Merchant Rajiv , Bhatt Rajiv
Published: October 2014

Osteosarcoma of the larynx is probably the rarest mesenchymal tumour of the larynx, with only 16 cases reported so far. The majority of them occur in males between the sixth and eighth decades of life. Patients usually present with non-specific symptoms such as dysphonia and upper airway compromise. The most common site of distant metastasis is the lung. Clinically, the tumour follows an aggressive course and is associated with high mortality. The case we present is unusual as it occurred at a young age (38 years) as compared with the norm and it did not arise from the endolarynx, unlike many of the other cases. This was the only known case where a Pearson near-total laryngectomy was performed whereby the patient's natural speech mechanism was preserved. This surgery was possible because the contralateral half of the larynx was clearly disease free and the interarytenoid region was uninvolved. The patient underwent postoperative adjuvant external beam radiotherapy beginning 4 weeks after surgery. The patient is doing well after 15 months of follow-up and shows no signs of recurrence.
HIV virological failure and drug resistance among injecting drug users receiving first-line ART in China
Authors: Leng Xuebing , Liang Shujia , Ma Yanling , Dong Yonghui , Kan Wei , Goan Daniel , Hsi Jenny H , Liao Lingjie , Wang Jing , He Cui , Zhang Heng , Xing Hui , Ruan Yuhua , Shao Yiming
Published: October 2014

Objective

To explore HIV virological failure and drug resistance among injecting drug users (IDUs) receiving first-line antiretroviral treatment (ART) in China.

Design

A series of cross-sectional surveys from 2003 to 2012 from the Chinese National HIV Drug Resistance (HIVDR) Surveillance and Monitoring Network.

Setting

China.

Participants

Data were analysed by the Chinese National (HIVDR) Surveillance and Monitoring Network from 2003 to 2012. Demographic, ART and laboratory data (CD4+ cell count, viral load and drug resistance) were included. Factors associated with virological failure were identified by logistic regression analysis.

Results

929 of the 8556 individuals in the Chinese HIVDR database were IDUs receiving first-line ART. For these 929 IDUs, the median duration of treatment was 14 months (IQR 6.0–17.8). 193 of the 929 IDUs (20.8%) experienced virological failure (HIV viral load ≥1000 copies/mL). The prevalence of HIVDR among patients with virological failure was 38.9% (68/175). The proportion of patients with drug resistance to non-nucleoside reverse transcriptase inhibitor (NNRTIs), nucleoside reverse transcriptase inhibitor (NRTIs) and protease inhibitors (PIs) was 52.9%, 76.5% and 4.4%, respectively. Factors independently associated with virological failure include: ethnic minorities, junior high school education or less, farmers, self-reported missing doses in the past month, CD4 cell count at survey from 200 to 349 cells/mm3or from 0 to 199 cells/mm3, and residence of Guangxi and Yunnan provinces.

Conclusions

The proportion of virological failure was high among IDUs receiving first-line ART in China. However, better treatment outcomes were observed in Guangxi and Yunnan, which indicates the importance of ART education and adherence to intervention, especially for patients who are farmers, minorities or have a poor educational background.
Views of NHS commissioners on commissioning support provision. Evidence from a qualitative study examining the early development of clinical commissioning groups in England
Authors: Petsoulas Christina , Allen Pauline , Checkland Kath , Coleman Anna , Segar Julia , Peckham Stephen , Mcdermott Imelda
Published: October 2014

Objective

The 2010 healthcare reform in England introduced primary care-led commissioning in the National Health Service (NHS) by establishing clinical commissioning groups (CCGs). A key factor for the success of the reform is the provision of excellent commissioning support services to CCGs. The Government's aim is to create a vibrant market of competing providers of such services (from both for-profit and not-for-profit sectors). Until this market develops, however, commissioning support units (CSUs) have been created from which CCGs are buying commissioning support functions. This study explored the attitudes of CCGs towards outsourcing commissioning support functions during the initial stage of the reform.

Design

The research took place between September 2011 and June 2012. We used a case study research design in eight CCGs, conducting in-depth interviews, observation of meetings and analysis of policy documents.

Setting/participants

We conducted 96 interviews and observed 146 meetings (a total of approximately 439 h).

Results

Many CCGs were reluctant to outsource core commissioning support functions (such as contracting) for fear of losing local knowledge and trusted relationships. Others were disappointed by the absence of choice and saw CSUs as monopolies and a recreation of the abolished PCTs. Many expressed doubts about the expectation that outsourcing of commissioning support functions will result in lower administrative costs.

Conclusions

Given the nature of healthcare commissioning, outsourcing vital commissioning support functions may not be the preferred option of CCGs. Considerations of high transaction costs, and the risk of fragmentation of services and loss of trusted relationships involved in short-term contracting, may lead most CCGs to decide to form long-term partnerships with commissioning support suppliers in the future. This option, however, limits competition by creating ‘network closure’ and calls into question the Government's intention to create a vibrant market of commissioning support provision.
Designing quality improvement initiatives: the action effect method, a structured approach to identifying and articulating programme theory
Authors: Reed Julie E , McNicholas Christopher , Woodcock Thomas , Issen Laurel , Bell Derek
Published: October 2014

Background

The identification and articulation of programme theory can support effective design, execution and evaluation of quality improvement (QI) initiatives. Programme theory includes an agreed aim, potential interventions to achieve this aim, anticipated cause/effect relationships between the interventions and the aim and measures to monitor improvement. This paper outlines the approach used in a research and improvement programme to support QI initiatives in identifying and articulating programme theory: the action effect method.

Background to method development

Building on a previously used QI method, the driver diagram, the action effect method was developed using co-design and iteration over four annual rounds of improvement initiatives. This resulted in a specification of the elements required to fully articulate the programme theory of a QI initiative.

The action effect method

The action effect method is a systematic and structured process to identify and articulate a QI initiative's programme theory. The method connects potential interventions and implementation activities with an overall improvement aim through a diagrammatic representation of hypothesised and evidenced cause/effect relationships. Measure concepts, in terms of service delivery and patient and system outcomes, are identified to support evaluation.

Discussion and conclusions

The action effect method provides a framework to guide the execution and evaluation of a QI initiative, a focal point for other QI methods and a communication tool to engage stakeholders. A clear definition of what constitutes a well-articulated programme theory is provided to guide the use of the method and assessment of the fidelity of its application.
Characteristics of small areas with high rates of hospital-treated self-harm: deprived, fragmented and urban or just close to hospital? A national registry study
Authors: O'Farrell I B , Corcoran P , Perry I J
Published: October 2014

Background

Previous research has shown an inconsistent relationship between the spatial distribution of hospital treated self-harm and area-level factors such as deprivation and social fragmentation. However, many of these studies have been confined to urban centres, with few focusing on rural settings and even fewer studies carried out at a national level. Furthermore, no previous research has investigated if travel time to hospital services can explain the area-level variation in the incidence of hospital treated self-harm.

Methods

From 2009 to 2011, the Irish National Registry of Deliberate Self Harm collected data on self-harm presentations to all hospital emergency departments in the country. The Registry uses standard methods of case ascertainment and also geocodes patient addresses to small area geographical level. Negative binomial regression was used to explore the ecological relationship between area-level self-harm rates and various area-level factors.

Results

Deprivation, social fragmentation and population density had a positive linear association with self-harm, with deprivation having the strongest independent effect. Furthermore, self-harm incidence was found to be elevated in areas that had shorter journey times to hospital. However, while this association became attenuated after controlling for other area-level factors it still remained statistically significant. A subgroup analysis examining the effect of travel time on specific methods of self-harm, found that this effect was most marked for self-harm acts involving minor self-cutting.

Conclusions

Self-harm incidence was influenced by proximity to hospital services, population density and social fragmentation; however, the strongest area-level predictor of self-harm was deprivation.
Elderly patients with intracranial aneurysms have higher quality of life after coil embolization: a decision analysis
Authors: Smith Michelle J , Sanborn Matthew R , Lewis Daniel J , Faught Ryan W F , Vakhshori Venus , Stein Sherman C
Published: October 2014

Objective

To develop a decision analytic model to calculate outcomes after treatment of cerebral aneurysms in elderly patients. Neurosurgical clipping and endovascular coiling for both ruptured and unruptured aneurysms were compared with predicted health-related quality of life (HRQoL) after treatment.

Methods

A Medline search of articles published in English between 1995 and June 2012 was performed using key words: ‘intracranial aneurysms’, ‘treatment’, or various combinations of ‘elderly’, ‘older’, or ‘decade’. Reports that met inclusion criteria used either the Glasgow Outcome Score or the modified Rankin Scale for outcomes, age >69, and intracranial aneurysm that was treated by endovascular coiling or surgical clipping. Data were collected by performing a comprehensive review of published reports. Meta-analysis (inverse variance-weighted, random effects) was used to calculate pooled values for probabilities and HRQoL.

Results

HRQoL was significantly higher for patients with coiled rather than clipped aneurysms in both ruptured (p<0.01) and unruptured (p<0.01) aneurysm groups. Periprocedural mortality rates were significantly lower among patients with a coiled, unruptured aneurysm than among patients with a clipped, unruptured aneurysm (p=0.032). Sensitivity analysis and Monte Carlo simulation for both ruptured and unruptured aneurysms showed that overall HRQoL was significantly higher in coiled than in clipped patients.

Conclusions

As life expectancy increases, treatment of cerebral aneurysms in the elderly becomes more important. Given the results of this decision analysis and the continuous refinement in endovascular technology, embolization should strongly be considered as a first-line treatment for cerebral aneurysms in the elderly.
Proinflammatory effects of arachidonic acid in a lipopolysaccharide-induced inflammatory microenvironment in 3T3-L1 adipocytes in vitro
Authors: Cranmer-Byng Mary M. , Liddle Danyelle M. , De Boer Anna A. , Monk Jennifer M. , Robinson Lindsay E.
Published: October 2014

Long-chain n-3 polyunsaturated fatty acids (PUFA), eicosapentaenoic acid (20:5n-3, EPA) and docosahexaenoic acid (22:6n-3, DHA), have known anti-inflammatory effects, including the modulation of adipose tissue-derived inflammatory mediators (i.e., adipokines) implicated in obesity-related pathologies, such as insulin resistance. Less is known about the effects of plant-derived n-3 PUFA, α-linolenic acid (ALA, 18:3n-3) and stearidonic acid (SDA 18:4n-3), or n-6 PUFA linoleic acid (LA, 18:2n-6) and arachidonic acid (AA, 20:4n-6), especially in combination with an inflammatory stimulus, such as lipopolysaccharide (LPS), at a dose intended to mimic obesity-associated low-grade inflammation. To study this, 3T3-L1 adipocytes were incubated with 100 μmol/L of various n-3 or n-6 PUFA with or without 10 ng/mL LPS for up to 24 h. AA in the presence of LPS synergistically increased (p < 0.05) pro-inflammatory monocyte chemoattractant protein-1 (MCP)-1 and interleukin (IL)-6 secretion and gene expression, as well as COX-2 and TLR2 gene expression at 6 and/or 24 h, suggesting their potential roles in the synergistic effects of AA and LPS. Plant-derived fatty acids ALA, SDA, and LA did not differentially affect adipokine gene expression or secretion, whereas LPS-induced pro-inflammatory IL-1β expression and MCP-1 secretion was decreased (p < 0.05) by EPA, DHA, and/or EPA+DHA (50 μmol/L each) compared with LPS alone. Only DHA increased (p < 0.05) gene expression of the n-3 PUFA receptor GPR120 and simultaneously decreased LPS-induced nuclear factor-κB activation compared with control. Our findings emphasize that specific fatty acids within the n-3 or n-6 PUFA class warrant consideration in the development of nutritional strategies to improve obesity-associated inflammation.
Permeability function for unsaturated soils with different initial densities
Authors: Cai Guoqing , Zhou Annan , Sheng Daichao
Published: October 2014

This study proposes an approach to simulate the effects of initial density on the relative coefficient of permeability for unsaturated soils. The density-dependent permeability function is derived based on (i) an incremental relationship between the degree of saturation and the initial void ratio with various suctions and (ii) the relationship between the permeability function and the soil-water retention curve (SWRC). Only one additional parameter is required in the proposed function, which can be calibrated using a conventional SWRC test. A number of test results in the literature are employed to validate the proposed density-dependent permeability function, and the model predictions indicate good agreement with the experimental data in the literature.
Effect of consolidation on responses of a single pile subjected to lateral soil movement
Authors: Wang L.Z. , Chen K.X. , Hong Y. , Ng C.W.W.
Published: October 2014

Given extensive research carried out to study pile response subjected to lateral soil movement in clay, the effect of consolidation on the pile–soil interaction is rarely considered and systematically investigated. For this reason, four centrifuge tests were conducted to simulate construction of embankment adjacent to existing single piles in soft clay, considering two typical drainage conditions (i.e., drained and undrained conditions) and two typical pile lengths (i.e., relatively long pile and short pile). The centrifuge tests were then back-analyzed by three-dimensional coupled-consolidation finite element analyses. Based on reasonable agreements between the two, numerical parametric studies were conducted to systematically investigate and quantify the influence of construction rate and pile length on pile response. It is revealed that by varying drainage conditions, the piles respond distinctively. When the embankment is completed within a relatively short period (cvt/d2 < 2, where cv, t, and d denote the coefficient of consolidation, construction period, and pile diameter, respectively), the pile located adjacent to it deforms laterally away from the embankment. Induced lateral pile deflection (δ) and bending moment reduce with construction period. On the contrary, embankment constructed within a relatively long period (cvt/d2 > 200) leads the pile to deform laterally towards the embankment, with δ and bending moment increases with construction period. By halving the length of pile embedded in the drained ground, the maximum induced bending moment (BMmax) was slightly reduced (by 23%). On the other hand, shortening the length of the pile in the undrained ground is much more effective in reducing BMmax, i.e., halving pile length resulting in 78% reduction in bending moment. A new calculation chart, which takes various drainage conditions and pile lengths into account, was developed for estimation of BMmax.
Infection of Picea abies clones with a homokaryotic isolate of Heterobasidion parviporum under field conditions
Authors: Keriö S. , Niemi S.M. , Haapanen M. , Daniel G. , Asiegbu F.O.
Published: October 2014

Heterobasidion parviporum Niemelä & Korhonen is responsible for the majority of decay in conifers in northern Europe, which causes severe economic losses. In nature, heterokaryotic isolates of H. parviporum cause infection in Norway spruce (Picea abies (L.) Karst.). However, little is known on whether homokaryons of H. parviporum can infect trees under field conditions. In this study, 40-year-old clonal Norway spruce stems and roots were inoculated with a homokaryotic isolate of H. parviporum under field conditions. After four months, the infection frequency and necrotic lesion lengths were recorded. The homokaryon caused infection and provoked the development of necrotic lesions. Necrotic lesions were larger in roots than in stems. Among the studied Norway spruce genotypes, a Russian clone had the smallest necrotic lesions, whereas a Finnish clone developed the largest necrotic lesions. Clones with higher growth rates were more sensitive to fungal infection and wound damage. Under microscopic observation, H. parviporum grew adpressed to lumen cell walls, colonized tracheids next to rays, and induced lignification in cell walls close to the point of inoculation. This study provides a starting point for further studies on the ability of homokaryons to cause infection under field conditions and for discussions on factors affecting the resistance of Norway spruce against H. parviporum.
Alteration in the expression ofexon IICtranscripts ofbrain-derived neurotrophic factorgene by simvastain in chronic mild stress in mice: a possible link with dopaminergic pathway
Authors: Rana Digvijay G. , Patel Amrutlal K. , Joshi Chaitanya G. , Jhala Mayurdhvaj K. , Goyal Ramesh K.
Published: October 2014

We have investigated the influence of dopaminergic agents on the expression of brain-derived neurotrophic factor (BDNF) gene in relation with lipid levels in chronic mild stress (CMS). Mice subjected to CMS were treated with simvastatin (10 mg/kg, per os (orally)) along with bromocriptine (2 mg/kg, intraperitoneally (ip)), levodopa (200 mg/kg, ip), or haloperidol (0.1 mg/kg, ip) for 14 days. CMS produced a decrease in sucrose intake and an increase in serum cholesterol and triglycerides levels with a decrease in high-density lipoprotein cholesterol, which were prevented by simvastatin. This was greater when it was combined with bromocriptine or levodopa. Haloperidol significantly prevented the simvastatin-induced increase in sucrose intake but not the alterations in lipids. There was an upregulation in the expression of BDNF exon-IIA and -IIB transcripts by CMS but not the exon-IIC transcripts. Simvastatin could increase expression of exon-IIC transcripts in stressed mice. This was partially increased by bromocriptine. Haloperidol significantly prevented simvastatin-induced increase in expression of BDNF exon-IIC transcripts. The results showed a positive correlation between expression of BDNF exon-IIC transcripts and sucrose intake. In conclusion, our data suggest the involvement of lipid levels and BDNF exon-IIC transcripts in CMS-induced behaviour in mice, possibly through the dopaminergic system.
Geometric effect on the vortex configuration and motion in mesoscopic superconducting cylinders
Authors: Wang Shan-Shan , Zha Guo-Qiao
Published: October 2014

Based on the time-dependent Ginzburg–Landau equations, we study numerically the vortex configuration and motion in mesoscopic superconducting cylinders. We find that the effects of the geometric symmetry of the system and the noncircular multiply-connected boundaries can significantly influence the steady vortex states and the vortex matter moving. For the square cylindrical loops, the vortices can enter the superconducting region in multiples of 2 and the vortex configuration exhibits the axial symmetry along the square diagonal. Moreover, the vortex dynamics behavior exhibits more complications due to the existed centered hole, which can lead to the vortex entering from different edges and exiting into the hole at the phase transitions.
An Ensemble System Based on Hybrid EGARCH-ANN with Different Distributional Assumptions to Predict S&P 500 Intraday Volatility
Authors: Lahmiri S. , Boukadoum M.
Published: October 2014

Accurate forecasting of stock market volatility is an important issue in portfolio risk management. In this paper, an ensemble system for stock market volatility is presented. It is composed of three different models that hybridize the exponential generalized autoregressive conditional heteroscedasticity (GARCH) process and the artificial neural network trained with the backpropagation algorithm (BPNN) to forecast stock market volatility under normal, t-Student, and generalized error distribution (GED) assumption separately. The goal is to design an ensemble system where each single hybrid model is capable to capture normality, excess skewness, or excess kurtosis in the data to achieve complementarity. The performance of each EGARCH-BPNN and the ensemble system is evaluated by the closeness of the volatility forecasts to realized volatility. Based on mean absolute error and mean of squared errors, the experimental results show that proposed ensemble model used to capture normality, skewness, and kurtosis in data is more accurate than the individual EGARCH-BPNN models in forecasting the S&P 500 intra-day volatility based on one and five-minute time horizons data.
RECENT PROGRESS IN EXPLORING DRAG REDUCTION MECHANISM OF REAL SHARKSKIN SURFACE: A REVIEW
Authors: LUO YUEHAO
Published: October 2014

It has gradually developed into an undisputable fact that sharkskin surface has the obvious drag reduction effect compared with the absolutely smooth skins, and it has been put into application widely, which has brought great advantages and profits in daily life, industry and agriculture. Because some problems in turbulence are not resolved completely and perfectly, the drag reduction mechanism of real sharkskin has also not been understood absolutely and thoroughly so far. However, many researchers have carried out lots of the relevant experiments and analyses, very plentiful and important conclusions are obtained, which can explain some certain phenomena of sharkskin drag reduction effect. An overview of exploring drag reduction mechanism of real sharkskin surface is systemically presented in detail. These mechanisms include inhibition of turbulence using micro/nano structured morphology, influence of scale's attack angles, nano-long chains and boundary layer slipping based on superhydrophobicity. This paper will improve the comprehension of the drag reduction mechanism and expand biomimetic sharkskin technology into more applications.
DIFFERENCES BETWEEN PULMONARY ARTERIAL AND AORTIC MATERIAL PROPERTIES
Authors: LI LIN , HUA LIN , ZHANG HAIXIA , LIU ZHICHENG
Published: October 2014

To investigate the differences of mechanical responses between pulmonary artery and aorta to different biaxial loading conditions, we simulated the process of human pulmonary artery and aorta subjected to biaxial loading based on four-family fiber strain density function model determined from uniaxial extension data of arterial walls. It was shown that different stress–strain curves of pulmonary artery and aorta under biaxial loading conditions: different loading ratios between the loads in two perpendicular directions and displacement-controlled equibiaxial stretch. Tissue stiffness, defined as the first derivative of the stress–strain response at a strain point, of human pulmonary artery and aorta were obtained when they were subjected to biaxial loads (systemic pressure). The two-dimensional mechanical response of artery can be acquired by determination of the four-family fiber strain density function model of the tissue based on uniaxial extensile data. There are differences between material properties of pulmonary artery and aorta: aorta is stiffer circumferentially than longitudinally, and pulmonary artery is more compliant circumferentially than longitudinally.
PERISTALTIC TRANSPORT OF MAXWELL VISCOELASTIC FLUIDS WITH A SLIP CONDITION: HOMOTOPY ANALYSIS OF GASTRIC TRANSPORT
Authors: TRIPATHI D. , ANWAR BÉG O.
Published: October 2014

Viscoelastic fluids arise frequently in numerous biophysical transport processes including gastric flow, embryology, haemo-dynamics and synovial lubrication. In the present article, we examine the effect of slip condition on peristaltic transport of viscoelastic fluids with the fractional Maxwell model through a two-dimensional deformable channel under the long wavelength and low Reynolds number assumptions, as a simulation of gastric flow. The channel is subjected to sinusoidal waves traveling along the walls. A versatile semi-analytical technique, the homotopy analysis method (HAM) is used to obtain approximate analytical solutions for the non-dimensionalized flow problem. The convergence of the HAM which depends on ℏ-curves is illustrated for relevant parameters. The effects of fractional parameters, relaxation time and slip parameter on the pressure difference and frictional force across one wavelength against time and averaged flow rate are illustrated graphically. It is found that effect of both fractional parameters on pressure is opposite to each other. The relaxation time and slip parameter are found to assist the peristaltic transportation. The behavior of frictional force is found to be similar to pressure in a magnitude sense whereas it is opposite in direction.
MECHANICAL STRESS IN ABDOMINAL AORTIC ANEURYSMS USING ARTIFICIAL NEURAL NETWORKS
Authors: SOUDAH EDUARDO , RODRÍGUEZ JOSÉ F. , LÓPEZ ROBERTO
Published: October 2014

Combination of numerical modeling and artificial intelligence (AI) in bioengineering processes are a promising pathway for the further development of bioengineering sciences. The objective of this work is to use Artificial Neural Networks (ANN) to reduce the long computational times needed in the analysis of shear stress in the Abdominal Aortic Aneurysm (AAA) by finite element methods (FEM). For that purpose two different neural networks are created. The first neural network (Mesh Neural Network, MNN) creates the aneurysm geometry in terms of four geometrical factors (asymmetry factor, aneurism diameter, aneurism thickness, aneurism length). The second neural network (Tension Neural Network, TNN) combines the results of the first neural network with the arterial pressure (new factor) to obtain the maximum stress distribution (output variable) in the aneurysm wall. The use of FEM for the analysis and design of bioengineering processes often requires high computational costs, but if this technique is combined with artificial intelligence, such as neural networks, the simulation time is significantly reduced. The shear stress obtained by the artificial neural models developed in this work achieved 95% of accuracy respect to the wall stress obtained by the FEM. On the other hand, the computational time is significantly reduced compared to the FEM.
DIMENSIONLESS OPTIMIZATION STUDY ON A VENTILATOR WITH SECRETION CLEARANCE FUNCTION
Authors: SHI YAN , NIU JINGLONG , CAI MAOLIN , XU WEIQING
Published: October 2014

To improve the efficiency and safety of secretion clearance, a novel ventilator (SC ventilator) with an automatic secretion clearance function is proposed. To lay a foundation for the optimization of the SC ventilator, the basic mathematical model of the ventilation system is derived. By selecting the appropriate reference values, the basic mathematical model is transformed to a dimensionless expression for simulation. Through the experimental and simulation study on the SC ventilation system, it can be concluded that: firstly, the mathematical model is proved to be authentic and reliable. Secondly, the influences of the three key parameters on the dynamics of the SC ventilation system are carried out. Last, to guarantee the pressure in the lung is higher than the expiratory positive airway pressure, the dimensionless minimum pressure in the flexible tube should be set higher than 0.9164, the dimensionless suction pressure should be set higher than 0.79.
Geographic mapping of choroidal thickness in myopic eyes using 1050-nm spectral domain optical coherence tomography
Authors: Zhang Qinqin , Neitz Maureen , Neitz Jay , Wang Ruikang K.
Published: October 2014

Purpose: To provide a geographical map of choroidal thickness (CT) around the macular region among subjects with low, moderate and high myopia. Methods: 20 myopic subjects (n = 40 eyes) without other identified pathologies participated in this study: 20 eyes of ≤ 3 diopters (D) (low myopic), 10 eyes between -3 and -6D (moderate myopic), and 10 eyes of ≥ 6D (high myopic). The mean age of subjects was 30.2 years (± 7.6 years; range, 24 to 46 years). A 1050 nm spectral-domain optical coherence tomography (SD-OCT) system, operating at 120 kHz imaging rate, was used in this study to simultaneously capture 3D anatomical images of the choroid and measure intraocular length (IOL) in the subject. The 3D OCT images of the choroid were segmented into superior, inferior, nasal and temporal quadrants, from which the CT was measured, representing radial distance between the outer retinal pigment epithelium (RPE) layer and inner scleral border. Measurements were made within concentric regions centered at fovea centralis, extended to 5 mm away from fovea at 1 mm intervals in the nasal and temporal directions. The measured IOL was the distance from the anterior cornea surface to the RPE in alignment along the optical axis of the eye. Statistical analysis was performed to evaluate CT at each geographic region and observe the relationship between CT and the degree of myopia. Results: For low myopic eyes, the IOL was measured at 24.619 ± 0.016 mm. The CT (273.85 ± 49.01 μm) was greatest under fovea as is in the case of healthy eyes. Peripheral to the fovea, the mean CT decreased rapidly along the nasal direction, reaching a minimum of 180.65 ± 58.25μm at 5 mm away from the fovea. There was less of a change in thickness from the fovea in the temporal direction reaching a minimum of 234.25 ± 42.27 μm. In contrast to the low myopic eyes, for moderate and high myopic eyes, CTs were thickest in temporal region (where CT = 194.94 ± 27.28 and 163 ± 34.89 μm, respectively). Like the low myopic eyes, moderate and high myopic eyes had thinnest CTs in the nasal region (where CT = 100.84 ± 16.75 and 86.64 ± 42.6μm, respectively). High myopic eyes had the longest mean IOL (25.983 ± 0.021mm), while the IOL of moderate myopia was 25.413 ± 0.022 mm (**p < 0.001). The CT reduction rate was calculated at 31.28 μm/D (diopter) from low to moderate myopia, whilst it is 13.49 μm/D from moderate to high myopia. The similar tendency was found for the IOL reduction rate in our study: 0.265 mm/D from low to moderate myopia, and 0.137 mm/D from moderate to high myopia. Conclusion: The CT decreases and the IOL increases gradually with the increase of myopic condition. The current results support the theory that choroidal abnormality may play an important role in the pathogenesis of myopic degeneration.
Reconstruction of fluid surface using physical property
Authors: Quan Hongyan , Wu Maomao
Published: October 2014

A novel technique for reconstructing fluid surface from video is introduced. Both fluid motion vectors as well as Lattice Boltzmann Method (LBM) are employed in the study. Region-based correlation method is used to initialize motion vectors field, after clustering fluid motion vector results can be obtained. Then the height geometry information of fluid surface can be calculated from fluid motion vector further. At last, the distribution of fluid particle is interpolated and the height field can be further refined. Reconstruction results are demonstrated with several challenge videos. The experimental results show that the method is convenient and efficient. The calculation results can reflect the characteristics of the fluid movement, and it is a valid method for reconstructing fluid surface.
Do Equity Markets Favor Credit Market News Over Options Market News?
Authors: Berndt Antje , Ostrovnaya Anastasiya
Published: October 2014

Credit default swap (CDS) and equity options markets often experience abnormal swings prior to the announcement of negative credit news. Option prices reveal information about such forthcoming adverse events at least as early as credit spreads, except for negative earnings announcements. Prior to negative credit news being announced, the equity market does not respond to abnormal movements in option prices unless that information has also manifested itself in credit spreads, perhaps because options are perceived as more likely to trade on unsubstantiated rumors than default swaps.
Cretaceous provenance change in the Hegang Basin and its connection with the Songliao Basin, NE China: evidence for lithospheric extension driven by palaeo-Pacific roll-back
Authors: Sun Mingdao , Chen Hanlin , Zhang Fengqi , Wilde Simon A. , Minna A. , Lin Xiubin , Yang Shufeng
Published: October 2014

The Cretaceous Hegang Basin is located on the Jiamusi Block, NE China, and separated from the Songliao Basin by the Lesser Xing'an Range (LXR). Seismic interpretation shows that the Chengzihe, Muling and Dongshan formations of the Hegang Basin thicken eastwards with westwards onlap, indicating that the LXR existed as a palaeo-uplift during that period, whereas the Houshigou Formation shows no thickness change, indicating that the LXR was possibly under water at this time. This is supported by results of detrital zircon analysis from the Hegang Basin in which the Chengzihe Formation is dominated by approximately 180 Ma zircons, which can only be provided by the LXR, whereas the Houshigou Formation records no Early Jurassic ages. This view is consistent with previous studies of the Songliao Basin for a provenance change between the Denglouku and Quantou formations. We conclude that the LXR was a highland during deposition of the Chengzihe, Muling and Dongshan formations but that it was under water when the Houshigou Formation was deposited. There was thus a connection between the Hegang and Songliao basins, which marks an eastwards migration of the depositional and extensional centre of the Songliao–Hegang basin system. This eastwards migration implies lithospheric extension driven by palaeo-Pacific roll-back.
Caveolin-1 regulates P2X7receptor signaling in osteoblasts
Authors: Gangadharan Vimal , Nohe Anja , Caplan Jeffrey , Czymmek Kirk , Duncan Randall L.
Published: October 2014

The synthesis of new bone in response to a novel applied mechanical load requires a complex series of cellular signaling events in osteoblasts and osteocytes. The activation of the purinergic receptor P2X7R is central to this mechanotransduction signaling cascade. Recently, P2X7R have been found to be associated with caveolae, a subset of lipid microdomains found in several cell types. Deletion of caveolin-1 (CAV1), the primary protein constituent of caveolae in osteoblasts, results in increased bone mass, leading us to hypothesize that the P2X7R is scaffolded to caveolae in osteoblasts. Thus, upon activation of the P2X7R, we postulate that caveolae are endocytosed, thereby modulating the downstream signal. Sucrose gradient fractionation of MC3T3-E1 preosteoblasts showed that CAV1 was translocated to the denser cytosolic fractions upon stimulation with ATP. Both ATP and the more specific P2X7R agonist 2′(3′)- O-(4-benzoylbenzoyl)ATP (BzATP) induced endocytosis of CAV1, which was inhibited when MC3T3-E1 cells were pretreated with the specific P2X7R antagonist A-839977. The P2X7R cofractionated with CAV1, but, using superresolution structured illumination microscopy, we found only a subpopulation of P2X7R in these lipid microdomains on the membrane of MC3T3-E1 cells. Suppression of CAV1 enhanced the intracellular Ca2+response to BzATP, suggesting that caveolae regulate P2X7R signaling. This proposed mechanism is supported by increased mineralization in CAV1 knockdown MC3T3-E1 cells treated with BzATP. These data suggest that caveolae regulate P2X7R signaling upon activation by undergoing endocytosis and potentially carrying with it other signaling proteins, hence controlling the spatiotemporal signaling of P2X7R in osteoblasts.
Monocarboxylate transporters 1 and 4: expression and regulation by PPARα in ovine ruminal epithelial cells
Authors: Benesch Franziska , Dengler Franziska , Masur Franziska , Pfannkuche Helga , Gäbel Gotthold
Published: October 2014

In the intact rumen epithelium, isoforms 1 and 4 of the monocarboxylate transporter (MCT1 and MCT4) are thought to play key roles in mediating transcellular and intracellular permeation of short-chain fatty acids and their metabolites and in maintaining intracellular pH. We examined whether both MCT1 and MCT4 are expressed at mRNA and protein levels in ovine ruminal epithelial cells (REC) maintained in primary culture and whether they are regulated by peroxisome proliferator-activated receptor-α (PPARα). Because both transporters have been characterized to function coupled to protons, the influence of PPARα on the recovery of intracellular pH after l-lactate exposure was evaluated by spectrofluorometry. MCT1 and MCT4 were detected using immunocytochemistry both at the cell margins and intracellularly in cultured REC. To test regulation by PPARα, cells were exposed to WY 14.643, a selective ligand of PPARα, for 48 h. The subsequent qPCR analysis resulted in a dose-dependent upregulation of MCT1 and PPARα target genes, whereas response of MCT4 was not uniform. Protein expression of MCT1 and MCT4 quantified by Western blot analysis was not altered by WY 14.643 treatment. l-Lactate-dependent proton export was blocked almost completely by pHMB, a specific inhibitor of MCT1 and MCT4. However, l-lactate-dependent, pHMB-inhibited proton export in WY 14.643-treated cells was not significantly altered compared with cells not treated with WY 14.643. These data suggest that PPARα is particularly regulating MCT1 but not MCT4 expression. Extent of lactate-coupled proton export indicates that MCT1 is already working on a high level even under unstimulated conditions.