bluuebunny/crossref_metadata_2025 huggingface dataset:
Knockout of Epstein-Barr Virus BPLF1 Retards B-Cell Transformation and Lymphoma Formation in Humanized Mice
Authors: Whitehurst Christopher B. , Li Guangming , Montgomery Stephanie A. , Montgomery Nathan D. , Su Lishan , Pagano Joseph S.
Published: October 2015

BPLF1 of Epstein-Barr virus (EBV) is classified as a late lytic cycle protein but is also found in the viral tegument, suggesting its potential involvement at both initial and late stages of viral infection. BPLF1 possesses both deubiquitinating and deneddylating activity located in its N-terminal domain and is involved in processes that affect viral infectivity, viral DNA replication, DNA repair, and immune evasion. A recently constructed EBV BPLF1-knockout (KO) virus was used in conjunction with a humanized mouse model that can be infected with EBV, enabling the first characterization of BPLF1 function
in vivo
. Results demonstrate that the BPLF1-knockout virus is approximately 90% less infectious than wild-type (WT) virus. Transformation of human B cells, a hallmark of EBV infection, was delayed and reduced with BPLF1-knockout virus. Humanized mice infected with EBV BPLF1-knockout virus showed less weight loss and survived longer than mice infected with equivalent infectious units of WT virus. Additionally, splenic tumors formed in 100% of mice infected with WT EBV but in only 25% of mice infected with BPLF1-KO virus. Morphological features of spleens containing tumors were similar to those in EBV-induced posttransplant lymphoproliferative disease (PTLD) and were almost identical to cases seen in human diffuse large B-cell lymphoma. The presence of EBV genomes was detected in all mice that developed tumors. The results implicate BPLF1 in human B-cell transformation and tumor formation in humanized mice.

IMPORTANCE
Epstein-Barr virus infects approximately 90% of the world's population and is the causative agent of infectious mononucleosis. EBV also causes aggressive lymphomas in individuals with acquired and innate immune disorders and is strongly associated with diffuse large B-cell lymphomas, classical Hodgkin lymphoma, Burkitt lymphoma, and nasopharyngeal carcinoma (NPC). Typically, EBV initially infects epithelial cells in the oropharynx, followed by a lifelong persistent latent infection in B-cells, which may develop into lymphomas in immunocompromised individuals. This work is the first of its kind in evaluating the effects of EBV's BPLF1 in terms of pathogenesis and lymphomagenesis in humanized mice and implicates BPLF1 in B-cell transformation and tumor development. Currently, there is no efficacious treatment for EBV, and therapeutic targeting of BPLF1 may lead to a new path to treatment for immunocompromised individuals or transplant recipients infected with EBV.
Neuroanatomical Characteristics of Deep and Superficial Needling Using Li11 as An Example
Authors: Wu Meiling , Cui Jingjing , Xu Dongsheng , Zhang Kun , Jing Xianghong , Bai Wanzhu
Published: October 2015

Objectives

To compare the neuroanatomical characteristics of the deep and superficial tissues at acupuncture point LI11 using a neural tracing technique, in order to examine the neural basis of potential differences between deep and superficial needling techniques.

Methods

In order to mimic the situations of the deep and superficial needling, the retrograde neural tracer Alexa Fluor 488 conjugate of cholera toxin subunit B (AF488-CTB) was injected into the muscle or subcutaneous tissue, respectively, at acupuncture point LI11 in eight rats (n=4 each). Three days following injection, the distribution of motor and sensory neurons labelled with AF488-CTB was examined in the spinal cord and dorsal root ganglia (DRG) under a fluorescent microscope.

Results

For both types of injection, labelled motor and sensory neurons were distributed on the side ipsilateral to the injection in the spinal cord and DRG between spinal levels C5 and T1. The number of labelled motor neurons following intramuscular injection was significantly higher than subcutaneous injection. By contrast, the number of labelled sensory neurons following subcutaneous injection was significantly higher in number and extended over a greater number of spinal segments compared to intramuscular injection.

Conclusions

These data indicate that the motor and sensory innervation of muscle and subcutaneous tissue beneath LI11 differ, and suggest that acupuncture signals induced by deep and superficial needling stimulation may be transmitted through different neural pathways.
Optimising adherence to childhood pneumonia treatment: the design and development of patient instructions and a job aid for amoxicillin dispersible tablets
Authors: Ebels Kelly , Faulx Dunia , Gerth-Guyette Emily , Murunga Peninah , Mahapatro Samarendra , Das Manoja Kumar , Ginsburg Amy Sarah
Published: October 2015

Introduction

Pneumonia is the leading cause of death from infection in children worldwide. Despite global treatment recommendations that call for children with pneumonia to receive amoxicillin dispersible tablets, only one-third of children with pneumonia receive any antibiotics and many do not complete the full course of treatment. Poor adherence to antibiotics may be driven in part by a lack of user-friendly treatment instructions.

Objective

In order to optimise childhood pneumonia treatment adherence at the community level, we developed a user-friendly product presentation for caregivers and a job aid for healthcare providers (HCPs). This paper aims to document the development process and offers a model for future health communication tools.

Methods

We employed an iterative design process that included document review, key stakeholder interviews, engagement with a graphic designer and pre-testing design concepts among target users in India and Kenya. The consolidated criteria for reporting qualitative research were used in the description of results.

Results

Though resources for pneumonia treatment are available in some countries, their content is incomplete and inconsistent with global recommendations. Document review and stakeholder interviews provided the information necessary to convey to caregivers and recommendations for how to present this information. Target users in India and Kenya confirmed the need to support better treatment adherence, recommended specific modifications to design concepts and suggested the development of a companion job aid. There was a consensus among caregivers and HCPs that these tools would be helpful and improve adherence behaviours.

Conclusions

The development of user-friendly instructions for medications for use in low-resource settings is a critically important but time-intensive and resource-intensive process that should involve engagement with target audiences.
A rare case describing catastrophic destruction of the whole skeleton caused by severe hyperparathyroidism
Authors: Akkas Burcu Esen , Demirel Busra Bedriye , Unlu Elif Nisa , Ucmak Gulin
Published: October 2015

Osteitis fibrosa cystica is a skeletal disorder seen in advanced stages of persistent hyperparathyroidism. Although the measurement of serum Ca and intact-parathormone levels provides early diagnosis and decreases the incidence of radiographic bone involvement, progressive major bone lesions may still be seen in developing countries even in the modern era. We aimed to share, by writing up this report, our astonishment after observing how the skeletal system can be ruined by persistent hyperparathyroidism.
Herlyn-Werner-Wunderlich and Prader-Willi syndromes: more than a coincidence?
Authors: Fraga Beatriz , Gomes Catarina , Gouveia Raquel , Oliveira Graça
Published: October 2015

A neonate with a prenatal diagnosis of left renal agenesis was born at 33 weeks gestation. A postnatal abdominal ultrasound confirmed the absence of the left kidney and revealed two non-divergent hemiuteri, consistent with the diagnosis of Herlyn-Werner-Wunderlich syndrome. During admission, significant axial hypotonia was noted, warranting additional investigations. Brain ultrasounds and MRI were normal, as were a preliminary metabolic study and comparative genomic hybridisation array. DNA methylation testing confirmed the diagnosis of Prader-Willi syndrome. The baby was discharged after 70 days, breast feeding and with modest hypotonia improvement.
Developing and validating a risk prediction model for acute care based on frailty syndromes
Authors: Soong J , Poots A J , Scott S , Donald K , Bell D
Published: October 2015

Objectives

Population ageing may result in increased comorbidity, functional dependence and poor quality of life. Mechanisms and pathophysiology underlying frailty have not been fully elucidated, thus absolute consensus on an operational definition for frailty is lacking. Frailty scores in the acute medical care setting have poor predictive power for clinically relevant outcomes. We explore the utility of frailty syndromes (as recommended by national guidelines) as a risk prediction model for the elderly in the acute care setting.

Setting

English Secondary Care emergency admissions to National Health Service (NHS) acute providers.

Participants

There were N=2 099 252 patients over 65 years with emergency admission to NHS acute providers from 01/01/2012 to 31/12/2012 included in the analysis.

Primary and secondary outcome measures

Outcomes investigated include inpatient mortality, 30-day emergency readmission and institutionalisation. We used pseudorandom numbers to split patients into train (60%) and test (40%). Receiver operator characteristic (ROC) curves and ordering the patients by deciles of predicted risk was used to assess model performance. Using English Hospital Episode Statistics (HES) data, we built multivariable logistic regression models with independent variables based on frailty syndromes (10th revision International Statistical Classification of Diseases, Injuries and Causes of Death (ICD-10) coding), demographics and previous hospital utilisation. Patients included were those >65 years with emergency admission to acute provider in England (2012).

Results

Frailty syndrome models exhibited ROC scores of 0.624–0.659 for inpatient mortality, 0.63–0.654 for institutionalisation and 0.57–0.63 for 30-day emergency readmission.

Conclusions

Frailty syndromes are a valid predictor of outcomes relevant to acute care. The models predictive power is in keeping with other scores in the literature, but is a simple, clinically relevant and potentially more acceptable measurement for use in the acute care setting. Predictive powers of the score are not sufficient for clinical use.
Does smoking cessation result in improved mental health? A comparison of regression modelling and propensity score matching
Authors: Taylor Gemma , Girling Alan , McNeill Ann , Aveyard Paul
Published: October 2015

Objectives

Smokers report that smoking is therapeutic; a recent meta-analysis suggests the contrary. However, the association in that review may be explained by group-membership bias and confounding. Propensity score matching (PSM) aims to produce causal estimates from observational data. We examined the association between cessation and change in mental health before and after PSM.

Design

A secondary analysis of prospective data from 5 placebo-controlled randomised trials for smoking reduction.

Participants

All participants were adult smokers and had smoked for at least 3 years. Participants were excluded if they were pregnant, breast feeding, under psychiatric care, deemed to be unfit by a general practitioner or part of a cessation programme. In total, 937 participants provided smoking data at both 6-month and 12-month follow-ups. Of these, 68 were confirmed as abstinent at both 6 and 12 months and 589 as continuous smokers at both follow-ups.

Primary outcome

Change in mental health (36-item Short Form Survey (SF-36), scored 0–100) from baseline (while all participants were smokers) to 12-month follow-up (after cessation) was compared between quitters and continuing smokers with and without adjustment, and after PSM.

Results

Before matching, quitters’ mental health scores improved compared with continuing smokers’, the mean difference and 95% CI was 5.5 (1.6 to 9.4). After adjustment, the difference was 4.5 (0.6 to 8.5), and after PSM, the difference was 3.4 (−2.2 to 8.9).

Conclusions

Improvements in mental health after smoking cessation may be partly but not completely explained by group membership bias and confounding.
Establishing the validity of English GP Patient Survey items evaluating out-of-hours care
Authors: Mounce Luke T A , Barry Heather E , Calitri Raffaele , Henley William E , Campbell John , Roland Martin , Richards Suzanne
Published: October 2015

Background

A 2014 national audit used the English General Practice Patient Survey (GPPS) to compare service users’ experience of out-of-hours general practitioner (GP) services, yet there is no published evidence on the validity of these GPPS items.

Objectives

Establish the construct and concurrent validity of GPPS items evaluating service users’ experience of GP out-of-hours care.

Methods

Cross-sectional postal survey of service users (n=1396) of six English out-of-hours providers. Participants reported on four GPPS items evaluating out-of-hours care (three items modified following cognitive interviews with service users), and 14 evaluative items from the Out-of-hours Patient Questionnaire (OPQ). Construct validity was assessed through correlations between any reliable (Cochran's α>0.7) scales, as suggested by a principal component analysis of the modified GPPS items, with the ‘entry access’ (four items) and ‘consultation satisfaction’ (10 items) OPQ subscales. Concurrent validity was determined by investigating whether each modified GPPS item was associated with thematically related items from the OPQ using linear regressions.

Results

The modified GPPS item-set formed a single scale (α=0.77), which summarised the two-component structure of the OPQ moderately well; explaining 39.7% of variation in the ‘entry access’ scores (r=0.63) and 44.0% of variation in the ‘consultation satisfaction’ scores (r=0.66), demonstrating acceptable construct validity. Concurrent validity was verified as each modified GPPS item was highly associated with a distinct set of related items from the OPQ.

Conclusions

Minor modifications are required for the English GPPS items evaluating out-of-hours care to improve comprehension by service users. A modified question set was demonstrated to comprise a valid measure of service users’ overall satisfaction with out-of-hours care received. This demonstrates the potential for the use of as few as four items in benchmarking providers and assisting services in identifying, implementing and assessing quality improvement initiatives.
Volume versus standard coils in the treatment of intracranial aneurysms
Authors: Kaesmacher Johannes , Müller-Leisse Christina , Huber Thomas , Boeckh-Behrens Tobias , Haller Bernhard , Shiban Ehab , Friedrich Benjamin , Zimmer Claus , Dorn Franziska , Prothmann Sascha
Published: October 2015

Background

Volume coils were developed to improve occlusion rates of intracranial aneurysms. Previous studies have shown increased packing density and comparable occlusion rates, but subgroup analyses of aneurysm size have not been carried out.

Objective

To evaluate the safety and efficacy of the Penumbra Coil 400 (PC400) system in treating intracranial aneurysms compared with standard diameter coils.

Methods

A monocentric retrospective case review of 260 aneurysms in 233 patients was carried out. In 37 aneurysms the PC400 system was used, while 223 aneurysms were treated with conventional coils. Previously treated aneurysms and aneurysms treated with flow diverters were excluded. Aneurysm and procedure characteristics, packing density, postprocedural and follow-up occlusion grades as well as coil compaction were evaluated.

Results

Aneurysms treated with PC400 coils had higher volume (218.9 vs 47.1 mm3, p<0.001), wider necks (3.0 vs 2.5 mm, p=0.005), and greater dome/neck ratio (2.0 vs 1.6, p=0.001) in comparison with aneurysms treated with conventional coils. Compared with controls, in the PC400 group we achieved higher packing densities (43.2% vs 34.4%, p<0.001; in aneurysms ≥7 mm 42.2% vs 27.8%, p<0.001). On follow-up angiography we observed less coil compaction (23.8% vs 64.3%, p=0.003) and less aneurysm recurrence (14.3% vs 40.5%, p=0.046) in aneurysms ≥7 mm when using the PC400 system.

Conclusions

Use of the PC400 system as opposed to conventional coils suggests that the PC400 system is safe and effective in treating intracranial aneurysms. Despite having been applied in a potentially more difficult-to-treat group, the use of PC400 was associated with less coil compaction and aneurysm recurrence in aneurysms ≥7 mm.
Pipeline embolization device for the treatment of vertebral artery aneurysms: the fate of covered branch vessels
Authors: Mazur Marcus D , Kilburg Craig , Wang Victor , Taussky Philipp
Published: October 2015

Introduction

Preliminary studies suggest that flow-diverting stents may be suitable for the treatment of aneurysms of the posterior circulation. The safety and efficacy of using flow-diverting stents for vertebral artery (VA) aneurysms is not well defined.

Objective

To examine the fate of covering the posterior inferior cerebellar artery (PICA) in patients undergoing placement of a flow-diverting stent for VA aneurysm.

Methods

Consecutive patients who underwent placement of a Pipeline Embolization Device (PED) for treatment of an aneurysm of the V4 segment of the VA between April 2012 and June 2015 at our institution were retrospectively evaluated. Angiograms were reviewed to determine the patency of the PICA when the vessel origin was covered by the PED.

Results

11 patients with VA aneurysms who underwent treatment with the PED were identified. In each case the device covered the origin of the PICA. Follow-up angiography in eight patients demonstrated thrombosis of the aneurysm with patency of the PICA.

Conclusions

Flow-diverting stents can be used for the treatment of VA aneurysms. When appropriately sized to the vessel wall and positioned in the VA, the device may cover the origin of the PICA without impairing flow through the branching artery.
Efficacy and safety of long-acting β-agonist/long-acting muscarinic antagonist combinations in COPD: a network meta-analysis
Authors: Oba Yuji , Sarva Siva T , Dias Sofia
Published: October 2015

Background

The place of long-acting β agonist/long-acting muscarinic antagonist (LABA/LAMA) combinations in stable patients with COPD is not well defined. The purpose of this study was to systematically review the efficacy and safety of LABA/LAMA combinations.

Methods

Several databases and manufacturers’ websites were searched for relevant clinical trials. Randomised control trials, at least 12 weeks duration, comparing a LABA/LAMA combination with placebo and/or monotherapy were included. The data were pooled using a network as well as a traditional direct comparison meta-analysis.

Results

Twenty-three trials with a total of 27 172 patients were included in the analysis. LABA/LAMA combinations were associated with a greater improvement in lung function, St. George's Respiratory Questionnaire (SGRQ) score, and Transitional Dyspnoea Index (TDI) than monotherapies. LABA/LAMA combinations were associated with a significantly greater proportion of SGRQ and TDI responders than monotherapies (OR 1.23 (95% credible interval (CrI) 1.06–1.39), OR 1.34 (95% CrI 1.19–1.50) versus LABAs and OR 1.24 (95% CrI 1.11–1.36), OR 1.31 (95% CrI 1.18–1.46) versus LAMAs, respectively) and fewer moderate-to-severe exacerbations compared with LABAs (HR 0.82 (95% CrI 0.73–0.93)), but not when compared with LAMAs (HR 0.92 (95% CrI 0.84–1.00)). There were no statistically significant differences associated with LABA/LAMA combinations compared with monotherapies in safety outcomes as well as in severe exacerbations.

Conclusions

The combination therapy was the most effective strategy in improving lung function, quality of life, symptom scores and moderate-to-severe exacerbation rates, and had similar effects on safety outcomes and severe exacerbations as compared with monotherapies.
Splenic myelolipoma in an old female greyhound
Authors: Persichetti Maria Flaminia , Caprì Alessandra , De Majo Massimo , Puleio Roberto , Iannelli Nicola Maria
Published: October 2015

A 10‐year‐old female greyhound presented with a suspected bulge on the left side of the abdomen. Abdominal ultrasound examination showed a large splenic mass that was surgically removed because of the suspected diagnosis of malignancy. Histological examination of the lesion revealed the presence of haematopoietic tissue mixed with well‐differentiated adipose tissue consistent with a splenic myelolipoma. A 24‐month follow‐up after splenectomy highlighted the good health of the greyhound. Therefore, the authors confirm that the approach could be elective treatment in this tumour. This case report, concerning a splenic myelolipoma in an asymptomatic old female greyhound, adds to the cases already mentioned in literature, and highlights the benignity of this lesion as well as the good prognosis of the patient when approached correctly.
Patella fracture repair in a black and white ruffed lemur (Varecia variegata)
Authors: Kubiak Marie , Barton Mark
Published: October 2015

A female black and white ruffed lemur presented for 10/10 lameness. Radiographs demonstrated a transverse patellar fracture with avulsion of the proximal fragment. Surgical repair was carried out and rehabilitation was completed using a purpose‐designed enclosure. Successful return to normal bipedal and quadrupedal mobility was achieved.
Associations between CD36 gene polymorphisms and metabolic response to a short-term endurance-training program in a young-adult population
Authors: Jayewardene Avindra F. , Mavros Yorgi , Gwinn Tom , Hancock Dale P. , Rooney Kieron B.
Published: October 2015

Recent studies have shown that CD36 gene variants are associated with an increased prevalence of chronic disease. Although a genetic component to trainability has been proven, no data are available specifically on the influence of CD36 on training response. Two single nucleotide polymorphisms (SNPs) (rs1527479 and rs1984112) were assessed for associations with whole-body substrate oxidation, response to a 75-g dextrose oral glucose tolerance test, fasting plasma lipids, and cardiovascular disease risk factors in a young healthy cohort, both using cross-sectional analysis and following a 4-week endurance-exercise training program. Genotyping was performed using real-time polymerase chain reaction. Cross-sectional data were collected in 34 individuals (age, 22.7 ± 3.5 years), with 17 completing the training program. At baseline, TT SNP carriers at rs1527479 and wild-type GG carriers at rs1984112 were associated with significantly greater whole-body rate of fat oxidation (Fatox) during submaximal exercise (P < 0.05), whilst AA carriers at the same position were associated with elevated triglyceride (TG) levels. A significant genotype × time interaction in Fatoxat SNP rs1984112 was identified at rest. Significant genotype × time interactions were present at rs1527479, with TT carriers exhibiting a favourable response to training when compared with C-allele carriers for fasting TG, diastolic blood pressure (DBP), and mean arterial pressure (MAP). In conclusion, cross-sectional assessment identified associations with Fatoxand TG. Training response at both SNPs identified “at-risk” genotypes responding favourably to the training stimulus in Fatox, TG, DBP, and MAP. Although these data show potential pleiotropic influence of CD36 SNPs, assessment in a larger cohort is warranted.
Analysis of consolidation with constant rate of displacement
Authors: Muir Wood David
Published: October 2015

The “constant rate of strain” consolidation test has been widely used for several decades to provide a continuous load–displacement response. An exact theoretical solution can be obtained for this consolidation problem. Two other solution techniques have pedagogic advantage in their simplicity, and in their ability to (i) clarify the phases of response of the consolidating sample and (ii) be extended to incorporate additional details of material response or testing configuration. The parabolic isochrone technique imposes a particular mode shape on the isochrones at all times. Treating the sample as a single system, and applying the boundary conditions at the system level, the governing equation becomes an ordinary differential equation. For more elaborate soil properties or experimental procedures a finite difference description of the problem is readily programmed and solved. These solution techniques are used to illustrate the importance of distinguishing between the observed response of the system — the soil specimen under test — and the behaviour of the soil elements that make up this system. Examples are given of erroneous conclusions that might be drawn if this distinction is not recognised.
Rv3351c, aMycobacterium tuberculosisgene that affects bacterial growth and alveolar epithelial cell viability
Authors: Pavlicek Rebecca L. , Fine-Coulson Kari , Gupta Tuhina , Quinn Frederick D. , Posey James E. , Willby Melisa , Castro-Garza Jorge , Karls Russell K.
Published: October 2015

Despite the interactions known to occur between various lower respiratory tract pathogens and alveolar epithelial cells (AECs), few reports examine factors influencing the interplay between Mycobacterium tuberculosis bacilli and AECs during infection. Importantly, in vitro studies have demonstrated that the M. tuberculosis hbha and esxA gene products HBHA and ESAT6 directly or indirectly influence AEC survival. In this report, we identify Rv3351c as another M. tuberculosis gene that impacts the fate of both the pathogen and AEC host. Intracellular replication of an Rv3351c mutant in the human AEC type II pneumocyte cell line A549 was markedly reduced relative to the complemented mutant and parent strain. Deletion of Rv3351c diminished the release of lactate dehydrogenase and decreased uptake of trypan blue vital stain by host cells infected with M. tuberculosis bacilli, suggesting attenuated cytotoxic effects. Interestingly, an isogenic hbha mutant displayed reductions in AEC killing similar to those observed for the Rv3351c mutant. This opens the possibility that multiple M. tuberculosis gene products interact with AECs. We also observed that Rv3351c aids intracellular replication and survival of M. tuberculosis in macrophages. This places Rv3351c in the same standing as HBHA and ESAT6, which are important factors in AECs and macrophages. Defining the mechanism(s) by which Rv3351c functions to aid pathogen survival within the host may lead to new drug or vaccine targets.
Equilibrium Lattice Relaxation and Misfit Dislocations in Continuously- and Step-Graded InxGa1-xAs/GaAs (001) and GaAs1-yPy/GaAs (001) Metamorphic Buffer Layers
Authors: Kujofsa Tedi , Ayers John E.
Published: October 2015

The inclusion of metamorphic buffer layers (MBL) in the design of lattice-mismatched semiconductor heterostructures is important in enhancing reliability and performance of optical and electronic devices. These metamorphic buffer layers usually employ linear grading of composition, and materials including InxGa1-xAs and GaAs1-yPy have been used. Non-uniform and continuously graded profiles are beneficial for the design of partially-relaxed buffer layers because they reduce the threading dislocation density by allowing the distribution of the misfit dislocations throughout the metamorphic buffer layer, rather than concentrating them at the interface where substrate defects and tangling can pin dislocations or otherwise reduce their mobility as in the case of uniform compositional growth. In this work we considered heterostructures involving a linearly-graded (type A) or step-graded (type B) buffer layer grown on a GaAs (001) substrate. For each structure type we present minimum energy calculations and compare the cases of cation (Group III) and anion (Group V) grading. In addition, we studied the (i) average and surface in-plane strain and (ii) average misfit dislocation density for heterostructures with various thickness and compositional profile. Moreover, we show that differences in the elastic stiffness constants give rise to significantly different behavior in these two commonly-used buffer layer systems.
Broadband Supercontinuum Generation in a Tapered-Rib Lead-Silicate Waveguide
Authors: Hu Hongyu , Li Wenbo , Zhang Xiang , Dutta Niloy K.
Published: October 2015

We have studied supercontinuum generation in a tapered-rib lead-silicate waveguide. The Air-SF57 glass-SiO2 waveguide is 2 cm long, with a varying etch depth to manage the dispersion profile. Numerical simulations are conducted for input sech2 pulses centered at 1.55 μm. Due to continuous modification of the phase matching condition for dispersive wave emission, the proposed waveguide geometry generates broadband output spectrum extending from ~1 μm to ~4.6 μm at −30 dB level. With proper pumping conditions, fully coherent supercontinuum can be obtained.
Sequential Logic Circuits Using Spatial Wavefunction Switched (SWS) FETs
Authors: Jagadeesan Neeraja , Saman B. , Lingalugari M. , Gogna P. , Jain F.
Published: October 2015

The spatial wavefunction-switched field-effect transistor (SWSFET) is one of the promising quantum well devices that transfers electrons from one quantum well channel to the other channel based on the applied gate voltage. This eliminates the use of more transistors as we have coupled channels in the same device operating at different threshold voltages. This feature can be exploited in many digital integrated circuits thus reducing the count of transistors which translates to less die area. The simulations of basic sequential circuits like SR latch, D latch and flip flop are presented here using SWSFET based logic gates. The circuit model of a SWSFET was developed using Berkeley short channel IGFET model (BSIM 3).
Wormhole geometries in Eddington-Inspired Born–Infeld gravity
Authors: Harko Tiberiu , Lobo Francisco S. N. , Mak M. K. , Sushkov Sergey V.
Published: October 2015

Eddington-inspired Born–Infeld (EiBI) gravity is a recently proposed modified theory of gravity, based on the classic work of Eddington and Born–Infeld nonlinear electrodynamics. In this paper, we consider the possibility that wormhole geometries are sustained in EiBI gravity. We present the gravitational field equations for an anisotropic stress–energy tensor and consider the generic conditions, for the auxiliary metric, at the wormhole throat. In addition to this, we obtain an exact solution for an asymptotically flat wormhole.
Topological phase transitions of three-dimensional topological insulator without energy gap closing
Authors: Chi Zimeng , Guo Xiaoyong , Wang Zaijun , Zheng Qiang
Published: October 2015

In this paper, we demonstrate an anomalous topological phase transition without closing of bulk energy gap. We find such an effect in a model of three-dimensional (3D) topological insulator (TI) subjected to the in-plane exchange field. The energy spectrum, spin spectrum and momentum-dependent spin Chern numbers are calculated. It is shown that our system realizes both the 3D TI phase and the integer quantum Hall (QH) phase. By varying the strength of exchange field, a series of topological phase transitions takes place and in the mean time the energy gap remains open. However, the spin spectrum is closed at the transition and various topological phases are characterized with different number of nodes in spin spectrum. In a tight-binding form, the surface modes are discussed to confirm with the phase diagram. Particularly for a strong field, we find the flat band edge modes which may provide an opportunity for realizing the two-dimensional (2D) fractional QH effect on the boundary of our 3D system.
Wave packet dynamics for Gross–Pitaevskii equation in one dimension: Dependence on initial conditions
Authors: Pal Sukla , Bhattacharjee Jayanta K.
Published: October 2015

The propagation of an initially Gaussian wave packet of width [Formula: see text] in Gross–Pitaevskii equation is extensively studied both for attractive and repulsive interactions. It is predicted analytically and verified numerically that for a free particle with attractive interaction, the dynamics of the width is governed by an effective potential which is sensitive to initial conditions. If [Formula: see text] is equal to a corresponding critical width [Formula: see text], then the packet will propagate in time with very little change in shape. These are in essence like coherent states. Whereas, if [Formula: see text], depending on the nature of the effective potential for chosen [Formula: see text] and the interaction strength [Formula: see text], the width of the packet in course of time, either oscillates with bounded width or will spread like a free particle. For a simple harmonic oscillator (SHO) also, we find that for [Formula: see text] smaller than a critical value, there always exists a coupling strength for which the packet simply oscillates about the mean position without changing its shape, once again providing a resemblance to a coherent state. We also consider the Morse potential, which interpolates between the free particle and the oscillator. For large attractive interactions, the two limiting dynamics (free and simple harmonic) are indeed observed but in the intermediate form of the potential where the nonlinear terms dominate in the dynamics, an initial Gaussian wave packet does not retain its shape. For repulsive interaction, the Gaussian packet always changes shape no matter what the system parameters are.
Phase-matched high-order harmonic generation in a semi-infinite gas cell with absorbing gaseous media
Authors: Vuong Cuong Van , Dinh Khuong Ba , Hannaford Peter , Dao Lap Van
Published: October 2015

We experimentally study the pressure dependent high-order harmonic generation in a semi-infinite gas cell with different absorbing gaseous media in order to reveal the influence of absorption in the high harmonic generation (HHG) process. Theoretical fits to the experimental results allow us to measure the absorption cross-section of the harmonics and to investigate the pressure independent phase mismatches. Our findings provide a better understanding about HHG in absorbing media and show that a sharp and intense harmonic spectrum can be generated as phase-matched and absorption-limited in a long interaction length geometry.
Investigation of two-pump fiber optical parametric amplifiers for a broadband and flat gain with a low pump-to-signal noise transfer
Authors: Pakarzadeh H. , Zakery A.
Published: October 2015

Two-pump fiber optical parametric amplifiers (2-P FOPAs) are investigated to obtain a broadband and flat gain simultaneously with a low pump-to-signal noise transfer. The analysis is performed based on the six-wave model to find the optimum pump wavelength separation and also the fiber length to simultaneously maximize the gain and minimize the noise transfer from the pump to the signal. The results of this paper show the potential of 2-P FOPAs for application in fiber optical communication systems; for example, wavelength division multiplexing (WDM).
Nonlinear and additive white noise perturbations of linear delay differential equations at the verge of instability: An averaging approach
Authors: Lingala N. , Sri Namachchivaya N.
Published: October 2015

The characteristic equation for a linear delay differential equation (DDE) has countably infinite roots on the complex plane. We deal with linear DDEs that are on the verge of instability, i.e. a pair of roots of the characteristic equation (eigenvalues) lie on the imaginary axis of the complex plane, and all other roots have negative real parts. We show that, when the system is perturbed by small noise, under an appropriate change of time scale, the law of the amplitude of projection onto the critical eigenspace is close to the law of a certain one-dimensional stochastic differential equation (SDE) without delay. Further, we show that the projection onto the stable eigenspace is small. These results allow us to give an approximate description of the delay-system using an SDE (without delay) of just one dimension. The proof is based on the martingale problem technique.
A Nonlinear Shear Deformable Nanoplate Model Including Surface Effects for Large Amplitude Vibrations of Rectangular Nanoplates with Various Boundary Conditions
Authors: Ansari Reza , Faghih Shojaei Mostafa , Mohammadi Vahid , Gholami Raheb , Darabi Mohammad Ali
Published: October 2015

In this paper, a geometrically nonlinear first-order shear deformable nanoplate model is developed to investigate the size-dependent geometrically nonlinear free vibrations of rectangular nanoplates considering surface stress effects. For this purpose, according to the Gurtin–Murdoch elasticity theory and Hamilton's principle, the governing equations of motion and associated boundary conditions of nanoplates are derived first. Afterwards, the set of obtained nonlinear equations is discretized using the generalized differential quadrature (GDQ) method and then solved by a numerical Galerkin scheme and pseudo arc-length continuation method. Finally, the effects of important model parameters including surface elastic modulus, residual surface stress, surface density, thickness and boundary conditions on the vibration characteristics of rectangular nanoplates are thoroughly investigated. It is found that with the increase of the thickness, nanoplates can experience different vibrational behavior depending on the type of boundary conditions.
Pleistocene Overkill and North American Mammalian Extinctions
Authors: Meltzer David J.
Published: October 2015

Clovis groups in Late Pleistocene North America occasionally hunted several now extinct large mammals. But whether their hunting drove 37 genera of animals to extinction has been disputed, largely for want of kill sites. Overkill proponents argue that there is more archaeological evidence than we ought to expect, that humans had the wherewithal to decimate what may have been millions of animals, and that the appearance of humans and the disappearance of the fauna is too striking to be a mere coincidence. Yet, there is less to these claims than meets the eye. Moreover, extinctions took place amid sweeping climatic and environmental changes as the Pleistocene came to an end. It has long been difficult to link those changes to mammalian extinctions, but the advent of ancient DNA, coupled with high-resolution paleoecological, radiocarbon, and archeological records, should help disentangle the relative role of changing climates and people in mammalian extinctions.
Resource Transfers and Human Life-History Evolution
Authors: Jones James Holland
Published: October 2015

Formal models of life-history evolution have been used to illuminate both the peculiarities of the human life cycle and its commonalities with those of other taxa. Understanding reproductive decisions in both the contemporary market-based economies of wealthy nation-states and rapidly changing populations largely of the Global South presents particular challenges to evolutionary life-history theory for several reasons. These include (a) the rapidity with which reproductive patterns change, (b) the magnitude of fertility reduction from previous equilibria, and (c) the frequent absence or even reversal of expected wealth-fertility gradients. These empirical challenges have been met to an increasing extent by specifically incorporating durable wealth and resource transfers into more traditional life-history models. Such relatively new models build on classical life-history theory to generate novel predictions. Among these are quite robust predictions that the existence of heritable wealth will decrease optimal fertility and that, once the system of resource transfers is established, fertility and resource transfers will coevolve.
Linguistic Relativity from Reference to Agency
Authors: Enfield N.J.
Published: October 2015

How are language, thought, and reality related? Interdisciplinary research on this question over the past two decades has made significant progress. Most of the work has been Neo-Whorfian in two senses: One, it has been driven by research questions that were articulated most explicitly and most famously by the linguistic anthropologist Benjamin Lee Whorf, and two, it has limited the scope of inquiry to Whorf's narrow interpretations of the key terms “language,” “thought,” and “reality.” This article first reviews some of the ideas and results of Neo-Whorfian work, concentrating on the special role of linguistic categorization in heuristic decision making. It then considers new and potential directions in work on linguistic relativity, taken broadly to mean the ways in which the perspective offered by a given language can affect thought (or mind) and reality. New lines of work must reconsider the idea of linguistic relativity by exploring the range of available interpretations of the key terms: in particular, “language” beyond reference, “thought” beyond nonsocial processing, and “reality” beyond brute, nonsocial facts.
Waste and Waste Management
Authors: Reno Joshua
Published: October 2015

Discard studies have demonstrated that waste is more than just a symptom of an all-too-human demand for meaning or a merely technical problem for sanitary engineers and public health officials. The afterlife of waste materials and processes of waste management reveal the centrality of transient and discarded things for questions of materiality and ontology and marginal and polluting labor and environmental justice movements, as well as for critiques of the exploitation and deferred promises of modernity and imperial formations. There is yet more waste will tell us, especially as more studies continue to document the many ways that our wastes are not only our problem, but become entangled with the lives of nonhuman creatures and the future of the planet we share.
The Unique Molecular Choreography of Giant Pore Formation by the Cholesterol-Dependent Cytolysins of Gram-Positive Bacteria
Authors: Tweten Rodney K. , Hotze Eileen M. , Wade Kristin R.
Published: October 2015

The mechanism by which the cholesterol-dependent cytolysins (CDCs) assemble their giant β-barrel pore in cholesterol-rich membranes has been the subject of intense study in the past two decades. A combination of structural, biophysical, and biochemical analyses has revealed deep insights into the series of complex and highly choreographed secondary and tertiary structural transitions that the CDCs undergo to assemble their β-barrel pore in eukaryotic membranes. Our knowledge of the molecular details of these dramatic structural changes in CDCs has transformed our understanding of how giant pore complexes are assembled and has been critical to our understanding of the mechanisms of other important classes of pore-forming toxins and proteins across the kingdoms of life. Finally, there are tantalizing hints that the CDC pore-forming mechanism is more sophisticated than previously imagined and that some CDCs are employed in pore-independent processes.
Physics of Intracellular Organization in Bacteria
Authors: Wingreen Ned S. , Huang Kerwyn Casey
Published: October 2015

With the realization that bacteria achieve exquisite levels of spatiotemporal organization has come the challenge of discovering the underlying mechanisms. In this review, we describe three classes of such mechanisms, each of which has physical origins: the use of landmarks, the creation of higher-order structures that enable geometric sensing, and the emergence of length scales from systems of chemical reactions coupled to diffusion. We then examine the diversity of geometric cues that exist even in cells with relatively simple geometries, and end by discussing both new technologies that could drive further discovery and the implications of our current knowledge for the behavior, fitness, and evolution of bacteria. The organizational strategies described here are employed in a wide variety of systems and in species across all kingdoms of life; in many ways they provide a general blueprint for organizing the building blocks of life.
How Is Fe-S Cluster Formation Regulated?
Authors: Mettert Erin L. , Kiley Patricia J.
Published: October 2015

Iron-sulfur (Fe-S) clusters are fundamental to numerous biological processes in most organisms, but these protein cofactors can be prone to damage by various oxidants (e.g., O2, reactive oxygen species, and reactive nitrogen species) and toxic levels of certain metals (e.g., cobalt and copper). Furthermore, their synthesis can also be directly influenced by the level of available iron in the environment. Consequently, the cellular need for Fe-S cluster biogenesis varies with fluctuating growth conditions. To accommodate changes in Fe-S demand, microorganisms employ diverse regulatory strategies to tailor Fe-S cluster biogenesis according to their surroundings. Here, we review the mechanisms that regulate Fe-S cluster formation in bacteria, primarily focusing on control of the Isc and Suf Fe-S cluster biogenesis systems in the model bacterium Escherichia coli.
Progress with High-Field Superconducting Magnets for High-Energy Colliders
Authors: Apollinari Giorgio , Prestemon Soren , Zlobin Alexander V.
Published: October 2015

One of the possible next steps for high-energy physics research relies on a high-energy hadron or muon collider. The energy of a circular collider is limited by the strength of bending dipoles, and its maximum luminosity is determined by the strength of final focus quadrupoles. For this reason, the high-energy physics and accelerator communities have shown much interest in higher-field and higher-gradient superconducting accelerator magnets. The maximum field of NbTi magnets used in all present high-energy machines, including the LHC, is limited to ∼10 T at 1.9 K. Fields above 10 T became possible with the use of Nb3Sn superconductors. Nb3Sn accelerator magnets can provide operating fields up to ∼15 T and can significantly increase the coil temperature margin. Accelerator magnets with operating fields above 15 T require high-temperature superconductors. This review discusses the status and main results of Nb3Sn accelerator magnet research and development and work toward 20-T magnets.
Lewis lung carcinoma regulation of mechanical stretch-induced protein synthesis in cultured myotubes
Authors: Gao Song , Carson James A.
Published: October 2015

Mechanical stretch can activate muscle and myotube protein synthesis through mammalian target of rapamycin complex 1 (mTORC1) signaling. While it has been established that tumor-derived cachectic factors can induce myotube wasting, the effect of this catabolic environment on myotube mechanical signaling has not been determined. We investigated whether media containing cachectic factors derived from Lewis lung carcinoma (LLC) can regulate the stretch induction of myotube protein synthesis. C2C12 myotubes preincubated in control or LLC-derived media were chronically stretched. Protein synthesis regulation by anabolic and catabolic signaling was then examined. In the control condition, stretch increased mTORC1 activity and protein synthesis. The LLC treatment decreased basal mTORC1 activity and protein synthesis and attenuated the stretch induction of protein synthesis. LLC media increased STAT3 and AMP-activated protein kinase phosphorylation in myotubes, independent of stretch. Both stretch and LLC independently increased ERK1/2, p38, and NF-κB phosphorylation. In LLC-treated myotubes, the inhibition of ERK1/2 and p38 rescued the stretch induction of protein synthesis. Interestingly, either leukemia inhibitory factor or glycoprotein 130 antibody administration caused further inhibition of mTORC1 signaling and protein synthesis in stretched myotubes. AMP-activated protein kinase inhibition increased basal mTORC1 signaling activity and protein synthesis in LLC-treated myotubes, but did not restore the stretch induction of protein synthesis. These results demonstrate that LLC-derived cachectic factors can dissociate stretch-induced signaling from protein synthesis through ERK1/2 and p38 signaling, and that glycoprotein 130 signaling is associated with the basal stretch response in myotubes.