A biologically inspired network design model

A network design problem is to select a subset of links in a transport network that satisfy passengers or cargo transportation demands while minimizing the overall costs of the transportation. We propose a mathematical model of the foraging behaviour of slime mould P. polycephalum to solve the network design problem and construct optimal transport networks. In our algorithm, a traffic flow between any two cities is estimated using a gravity model. The flow is imitated by the model of the slime mould. The algorithm model converges to a steady state, which represents a solution of the problem. We validate our approach on examples of major transport networks in Mexico and China. By comparing networks developed in our approach with the man-made highways, networks developed by the slime mould, and a cellular automata model inspired by slime mould, we demonstrate the flexibility and efficiency of our approach

Open versus laparoscopically-assisted oesophagectomy for cancer: a multicentre randomised controlled phase III trial - the MIRO trial

<p>Abstract</p> <p>Background</p> <p>Open transthoracic oesophagectomy is the standard treatment for infracarinal resectable oesophageal carcinomas, although it is associated with high mortality and morbidity rates of 2 to 10% and 30 to 50%, respectively, for both the abdominal and thoracic approaches. The worldwide popularity of laparoscopic techniques is based on promising results, including lower postoperative morbidity rates, which are related to the reduced postoperative trauma. We hypothesise that the laparoscopic abdominal approach (laparoscopic gastric mobilisation) in oesophageal cancer surgery will decrease the major postoperative complication rate due to the reduced surgical trauma.</p> <p>Methods/Design</p> <p>The MIRO trial is an open, controlled, prospective, randomised multicentre phase III trial. Patients in study arm A will receive laparoscopic-assisted oesophagectomy, i.e., a transthoracic oesophagectomy with two-field lymphadenectomy and laparoscopic gastric mobilisation. Patients in study arm B will receive the same procedure, but with the conventional open abdominal approach. The primary objective of the study is to evaluate the major postoperative 30-day morbidity. Secondary objectives are to assess the overall 30-day morbidity, 30-day mortality, 30-day pulmonary morbidity, disease-free survival, overall survival as well as quality of life and to perform medico-economic analysis. A total of 200 patients will be enrolled, and two safety analyses will be performed using 25 and 50 patients included in arm A.</p> <p>Discussion</p> <p>Postoperative morbidity remains high after oesophageal cancer surgery, especially due to major pulmonary complications, which are responsible for 50% of the postoperative deaths. This study represents the first randomised controlled phase III trial to evaluate the benefits of the minimally invasive approach with respect to the postoperative course and oncological outcomes in oesophageal cancer surgery.</p> <p>Trial Registration</p> <p><a href="http://www.clinicaltrials.gov/ct2/show/NCT00937456">NCT00937456</a> (ClinicalTrials.gov)</p

The rise of China in the international trade network: a community core detection approach

Theory of complex networks proved successful in the description of a variety of static networks ranging from biology to computer and social sciences and to economics and finance. Here we use network models to describe the evolution of a particular economic system, namely the International Trade Network (ITN). Previous studies often assume that globalization and regionalization in international trade are contradictory to each other. We re-examine the relationship between globalization and regionalization by viewing the international trade system as an interdependent complex network. We use the modularity optimization method to detect communities and community cores in the ITN during the years 1995-2011. We find rich dynamics over time both inter- and intra-communities. Most importantly, we have a multilevel description of the evolution where the global dynamics (i.e., communities disappear or reemerge) tend to be correlated with the regional dynamics (i.e., community core changes between community members). In particular, the Asia-Oceania community disappeared and reemerged over time along with a switch in leadership from Japan to China. Moreover, simulation results show that the global dynamics can be generated by a preferential attachment mechanism both inter- and intra- communities

A Concerted Action of Hepatitis C Virus P7 and Nonstructural Protein 2 Regulates Core Localization at the Endoplasmic Reticulum and Virus Assembly

Hepatitis C virus (HCV) assembly remains a poorly understood process. Lipid droplets (LDs) are thought to act as platforms for the assembly of viral components. The JFH1 HCV strain replicates and assembles in association with LD-associated membranes, around which viral core protein is predominantly detected. In contrast, despite its intrinsic capacity to localize to LDs when expressed individually, we found that the core protein of the high-titer Jc1 recombinant virus was hardly detected on LDs of cell culture-grown HCV (HCVcc)-infected cells, but was mainly localized at endoplasmic reticulum (ER) membranes where it colocalized with the HCV envelope glycoproteins. Furthermore, high-titer cell culture-adapted JFH1 virus, obtained after long-term culture in Huh7.5 cells, exhibited an ER-localized core in contrast to non-adapted JFH1 virus, strengthening the hypothesis that ER localization of core is required for efficient HCV assembly. Our results further indicate that p7 and NS2 are HCV strain-specific factors that govern the recruitment of core protein from LDs to ER assembly sites. Indeed, using expression constructs and HCVcc recombinant genomes, we found that p7 is sufficient to induce core localization at the ER, independently of its ion-channel activity. Importantly, the combined expression of JFH1 or Jc1 p7 and NS2 induced the same differential core subcellular localization detected in JFH1- vs. Jc1-infected cells. Finally, results obtained by expressing p7-NS2 chimeras between either virus type indicated that compatibilities between the p7 and the first NS2 trans-membrane domains is required to induce core-ER localization and assembly of extra- and intra-cellular infectious viral particles. In conclusion, we identified p7 and NS2 as key determinants governing the subcellular localization of HCV core to LDs vs. ER and required for initiation of the early steps of virus assembly

Sexual dysfunction among married couples living in Kumasi metropolis, Ghana

<p>Abstract</p> <p>Background</p> <p>Sexuality and its manifestation constitute some of the most complex of human behaviour and its disorders are encountered in community. Sexual dysfunction is more prevalent in women than in men. While studies examining sexual dysfunction among males and females in Ghana exist, there are no studies relating sexual problems in males and females as dyadic units. This study therefore investigated the prevalence and type of sexual disorders among married couples.</p> <p>Method</p> <p>The study participants consisted of married couples between the ages of 19 and 66 living in the province of Kumasi, Ghana. Socio-demographic information and Golombok-Rust Inventory of Sexual Satisfaction (GRISS) questionnaires were administered to 200 couples who consented to take part in the study. All 28 questions of the GRISS are answered on a five-point (Likert type) scale from "always", through "usually', "sometimes", and "hardly ever", to "never". Responses are summed up to give a total raw score ranging from 28-140. The total score and subscale scores are transformed using a standard nine point scale, with high scores indicating greater problems. Scores of five or more are considered to indicate SD. The study was conducted between July and September 2010.</p> <p>Results</p> <p>Out of a total of 200 married couples, 179 completed their questionnaires resulting in a response rate of 89.5%. The mean age of the participating couples as well as the mean duration of marriage was 34.8 ± 8.6 years and 7.8 ± 7.6 years respectively. The husbands (37.1 ± 8.6) were significantly older (p < 0.0001) than their corresponding wives (32.5 ± 7.9). After adjusting for age, 13-18 years of marriage life poses about 10 times significant risk of developing SD compared to 1-6 years of married life among the wives (OR: 10.8; CI: 1.1 - 49.1; p = 0.04). The total scores (6.0) as well as the percentage above the cut-off (59.2) obtained by the husbands compared to the total score (6.2) and the percentage above cut-off (61.5) obtained by the wives, indicates the likely presence of sexual dysfunction. The prevalence of impotence and premature ejaculation were 60.9% and 65.4% respectively from this study and the prevalence of vaginismus and anorgasmia were 69.3% and 74.9% respectively. The highest prevalence of SD subscales among the men was dissatisfaction with sexual act followed by infrequency, whereas the highest among the women was infrequency followed by anorgasmia. Dissatisfaction with sexual intercourse among men correlated positively with anorgasmia and wife's non-sensuality and infrequency of sex.</p> <p>Conclusion</p> <p>The prevalence of sexual dysfunction in married couples is comparable to prevalence rates in the general male and female population and is further worsened by duration of marriage. This could impact significantly on a couple's self-esteem and overall quality of life.</p

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

Somatostatin analogues in the treatment of gastroenteropancreatic neuroendocrine tumours, current aspects and new perspectives

Gastroenteropancreatic neuroendocrine tumours (GEP NETs) are rare tumours that present many clinical features