Dynamic LightPath allocation in WDM networks using an SDN controller

Core wavelength division multiplexed (WDM) networks are widely used to provide fixed physical connectivity and bandwidth to the logically connected upper electronic layer devices using optical signals. However, growing demands for bandwidth-intensive applications and cloud-based services push optical networks carriers' to provide scalable and flexible services dynamically. Software defined networking (SDN) has the potential to program electronic layers by dynamically controlling and managing network resources using SDN controller applications. SDN's on-demand characteristics combined with the optical circuit-switching can enable optical network service providers to customize their service provisioning dynamically to the user's requirements. They enable fast provision of new services, and minimize underutilization of resources. In this paper, a model is proposed to bring the dynamic allocation of resources which is a layer 2+ functionality, to the WDM layer using SDN. A middle-ware application based on SDN and OpenFlow for dynamic switching and provisioning of optical service is presented. The application abstracts the optical layer's connectivity, also accounting for the switching constraints. Details of the model's implementation are discussed considering classically used equipment and its performance in terms of CPU and memory utilization, topology emulation time, and latency is evaluated. Finally, the application is tested with a Cisco layer one switch. Performance results show that the latency doubles when increasing the number of fibers of an optical cross connect from 5 to 7 and keeping wavelengths equal to 8, with Clos fabric topology

Using family history information to promote healthy lifestyles and prevent diseases; a discussion of the evidence.

BACKGROUND: A family history, reflecting genetic susceptibility as well as shared environmental and behavioral factors, is an important risk factor for common chronic multifactorial diseases such as cardiovascular diseases, type 2 diabetes and many cancers. DISCUSSION: The purpose of the present paper is to discuss the evidence for the use of family history as a tool for primary prevention of common chronic diseases, in particular for tailored interventions aimed at promoting healthy lifestyles. The following questions are addressed: (1) What is the value of family history information as a determinant of personal disease risk?; (2)How can family history information be used to motivate at-risk individuals to adopt and maintain healthy lifestyles in order to prevent disease?; and (3) What additional studies are needed to assess the potential value of family history information as a tool to promote a healthy lifestyle? SUMMARY: In addition to risk assessment, family history information can be used to personalize health messages, which are potentially more effective in promoting healthy lifestyles than standardized health messages. More research is needed on the evidence for the effectiveness of such a tool.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

Outcome of index upper gastrointestinal endoscopy in patients presenting with dysphagia in a tertiary care hospital-A 10 years review

<p>Abstract</p> <p>Background</p> <p>Patients with malignant tumours of the upper gastrointestinal tract tumours exhibit important alarm symptoms such as dysphagia that warrant clinical investigations. An endoscopic examination of the upper gastrointestinal tract will be required in most cases. This study evaluates the diagnostic potential of index endoscopy in a random population of patients with dysphagia.</p> <p>Methods</p> <p>This is a retrospective analysis of prospectively collected data over 10 years. Patients with previous endoscopic evaluation or upper gastrointestinal pathology were excluded from the study. Data was analysed to see the number and frequency of abnormal findings in upper gastrointestinal tract, and their significance in relation to the presenting symptoms.</p> <p>Results</p> <p>Total number of index endoscopies was 13, 881. 913 patients were included in the study including 465 males (age range: 17–92 years, median: 55 years) and 448 females (age range: 18–100, median: 59 years), with male to female ratio of 1.04: 1. Oesophagus was abnormal in 678 cases (74%) and biopsies were taken in 428 patients (47%). Superficial oesophagitis, Barrett's oesophagus, oesophageal cancer, and oesophageal ulcer were main histological findings. Age more than 50 years and weight loss were significant predictors of oesophageal cancer (p < 0.0001). Male gender, heartburn, epigastric pain, weight loss and vomiting were significantly related to Barrett's oesophagus. A total of 486 gastric and 56 duodenal biopsies were also taken. There were 20 cases of gastric adenocarcinoma.</p> <p>Conclusion</p> <p>OGD is an effective initial investigation to assess patients with dysphagia, especially males above the age of 50 years. Patients may be started on treatment or referred for further investigations, for example, a barium meal in the absence of any anatomical abnormality.</p

Cholesterol and the risk of grade-specific prostate cancer incidence: evidence from two large prospective cohort studies with up to 37 years' follow up

&lt;b&gt;Background&lt;/b&gt; High cholesterol may be a modifiable risk factor for prostate cancer but results have been inconsistent and subject to potential "reverse causality" where undetected disease modifies cholesterol prior to diagnosis.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Methods&lt;/b&gt; We conducted a prospective cohort study of 12,926 men who were enrolled in the Midspan studies between 1970 and 1976 and followed up to 31st December 2007. We used Cox-Proportional Hazards Models to evaluate the association between baseline plasma cholesterol and Gleason grade-specific prostate cancer incidence. We excluded cancers detected within at least 5 years of cholesterol assay.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Results&lt;/b&gt; 650 men developed prostate cancer in up to 37 years' follow-up. Baseline plasma cholesterol was positively associated with hazard of high grade (Gleason score[greater than or equal to]8) prostate cancer incidence (n=119). The association was greatest among men in the 4th highest quintile for cholesterol, 6.1 to &#60;6.69 mmol/l, Hazard Ratio 2.28, 95% CI 1.27 to 4.10, compared with the baseline of &#60;5.05 mmol/l. This association remained significant after adjustment for body mass index, smoking and socioeconomic status.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Conclusions&lt;/b&gt; Men with higher cholesterol are at greater risk of developing high-grade prostate cancer but not overall risk of prostate cancer. Interventions to minimise metabolic risk factors may have a role in reducing incidence of aggressive prostate cancer

Numerical simulation of blood flow and pressure drop in the pulmonary arterial and venous circulation

A novel multiscale mathematical and computational model of the pulmonary circulation is presented and used to analyse both arterial and venous pressure and flow. This work is a major advance over previous studies by Olufsen et al. (Ann Biomed Eng 28:1281–1299, 2012) which only considered the arterial circulation. For the first three generations of vessels within the pulmonary circulation, geometry is specified from patient-specific measurements obtained using magnetic resonance imaging (MRI). Blood flow and pressure in the larger arteries and veins are predicted using a nonlinear, cross-sectional-area-averaged system of equations for a Newtonian fluid in an elastic tube. Inflow into the main pulmonary artery is obtained from MRI measurements, while pressure entering the left atrium from the main pulmonary vein is kept constant at the normal mean value of 2 mmHg. Each terminal vessel in the network of ‘large’ arteries is connected to its corresponding terminal vein via a network of vessels representing the vascular bed of smaller arteries and veins. We develop and implement an algorithm to calculate the admittance of each vascular bed, using bifurcating structured trees and recursion. The structured-tree models take into account the geometry and material properties of the ‘smaller’ arteries and veins of radii ≥ 50 μ m. We study the effects on flow and pressure associated with three classes of pulmonary hypertension expressed via stiffening of larger and smaller vessels, and vascular rarefaction. The results of simulating these pathological conditions are in agreement with clinical observations, showing that the model has potential for assisting with diagnosis and treatment for circulatory diseases within the lung

Giant cell tumor of the temporal bone – a case report

BACKGROUND: Giant cell tumor is a benign but locally aggressive bone neoplasm which uncommonly involves the skull. The petrous portion of the temporal bone forms a rare location for this tumor. CASE PRESENTATION: The authors report a case of a large giant cell tumor involving the petrous and squamous portions of the temporal bone in a 26 year old male patient. He presented with right side severe hearing loss and facial paresis. Radical excision of the tumor was achieved but facial palsy could not be avoided. CONCLUSION: Radical excision of skull base giant cell tumor may be hazardous but if achieved is the optimal treatment and may be curative

Helicobacter pylori versus the Host: Remodeling of the Bacterial Outer Membrane Is Required for Survival in the Gastric Mucosa

Modification of bacterial surface structures, such as the lipid A portion of lipopolysaccharide (LPS), is used by many pathogenic bacteria to help evade the host innate immune response. Helicobacter pylori, a gram-negative bacterium capable of chronic colonization of the human stomach, modifies its lipid A by removal of phosphate groups from the 1- and 4′-positions of the lipid A backbone. In this study, we identify the enzyme responsible for dephosphorylation of the lipid A 4′-phosphate group in H. pylori, Jhp1487 (LpxF). To ascertain the role these modifications play in the pathogenesis of H. pylori, we created mutants in lpxE (1-phosphatase), lpxF (4′-phosphatase) and a double lpxE/F mutant. Analysis of lipid A isolated from lpxE and lpxF mutants revealed lipid A species with a 1 or 4′-phosphate group, respectively while the double lpxE/F mutant revealed a bis-phosphorylated lipid A. Mutants lacking lpxE, lpxF, or lpxE/F show a 16, 360 and 1020 fold increase in sensitivity to the cationic antimicrobial peptide polymyxin B, respectively. Moreover, a similar loss of resistance is seen against a variety of CAMPs found in the human body including LL37, β-defensin 2, and P-113. Using a fluorescent derivative of polymyxin we demonstrate that, unlike wild type bacteria, polymyxin readily associates with the lpxE/F mutant. Presumably, the increase in the negative charge of H. pylori LPS allows for binding of the peptide to the bacterial surface. Interestingly, the action of LpxE and LpxF was shown to decrease recognition of Helicobacter LPS by the innate immune receptor, Toll-like Receptor 4. Furthermore, lpxE/F mutants were unable to colonize the gastric mucosa of C57BL/6J and C57BL/6J tlr4 -/- mice when compared to wild type H. pylori. Our results demonstrate that dephosphorylation of the lipid A domain of H. pylori LPS by LpxE and LpxF is key to its ability to colonize a mammalian host

Coordinated Regulation of ATF2 by miR-26b in γ-Irradiated Lung Cancer Cells

MicroRNA regulates cellular responses to ionizing radiation (IR) through translational control of target genes. We analyzed time-series changes in microRNA expression following γ-irradiation in H1299 lung cancer cells using microarray analysis. Significantly changed IR-responsive microRNAs were selected based on analysis of variance analysis, and predicted target mRNAs were enriched in mitogen-activated protein kinase (MAPK) signaling. Concurrent analysis of time-series mRNA and microRNA profiles uncovered that expression of miR-26b was down regulated, and its target activating transcription factor 2 (ATF2) mRNA was up regulated in γ-irradiated H1299 cells. IR in miR-26b overexpressed H1299 cells could not induce expression of ATF2. When c-Jun N-terminal kinase activity was inhibited using SP600125, expression of miR-26b was induced following γ-irradiation in H1299 cells. From these results, we concluded that IR-induced up-regulation of ATF2 was coordinately enhanced by suppression of miR-26b in lung cancer cells, which may enhance the effect of IR in the MAPK signaling pathway

Hybrid materials for molecular sieves

Hybrid microporous organosilica membranes for molecular separations made by acid-catalyzed solgel synthesis from bridged silsesquioxane precursors have demonstrated good performance in terms of flux and selectivity and remarkable hydrothermal stability in various pervaporation and gas separation processes. The availability of wide range of α,ω-bis(trialkoxysilyl)alkane and 1,4-bis (triethoxysilyl)benzene precursors allows tuning of membrane properties such as pore size and chemistry. This chapter presents an overview of the synthesis and application of hybrid organosilica microporous membranes in liquid and gas separation processes. After a concise discussion of the history of solgel-derived microporous ceramic membranes for molecular separations, the solgel chemistry of bridged silsesquioxanes and all relevant processing steps needed to obtain a supported microporous films suitable for molecular separations are discussed. The performance of these membranes is correlated with the membrane compositional properties, such as nature, stiffness and length of the bridging group, and details of the solgel process

Screening a Peptide Library by DSC and SAXD: Comparison with the Biological Function of the Parent Proteins

We have recently identified the membranotropic regions of the hepatitis C virus proteins E1, E2, core and p7 proteins by observing the effect of protein-derived peptide libraries on model membrane integrity. We have studied in this work the ability of selected sequences of these proteins to modulate the Lβ-Lα and Lα-HII phospholipid phase transitions as well as check the viability of using both DSC and SAXD to screen a protein-derived peptide library. We demonstrate that it is feasible to screen a library of peptides corresponding to one or several proteins by both SAXD and DSC. This methodological combination should allow the identification of essential regions of membrane-interacting proteins which might be implicated in the molecular mechanism of membrane fusion and/or budding