Exploring modularity in biological networks

Network theoretical approaches have shaped our understanding of many different kinds of biological modularity. This essay makes the case that to capture these contributions, it is useful to think about the role of network models in exploratory research. The overall point is that it is possible to provide a systematic analysis of the exploratory functions of network models in bioscientific research. Using two examples from molecular and developmental biology, I argue that often the same modelling approach can perform one or more exploratory functions, such as introducing new directions of research, offering a complementary set of concepts, methods and algorithms for individuating important features of natural phenomena, generating proofs of principle demonstrations and potential explanations for phenomena of interest and enlarging the scope of certain research agendas. This article is part of the theme issue 'Unifying the essential concepts of biological networks: biological insights and philosophical foundations'

New occurrence of B chromosomes in Partamonahelleri (Friese, 1900) (Hymenoptera, Meliponini)

Cytogenetic analyses of the stingless bee Partamona helleri collected in the state of Bahia, Northeast Brazil revealed the chromosome numbers n = 18 in the haploid males and 2n = 35 in the diploid females. All karyotypes displayed one large acrocentric B chromosome, which differs from the minute B chromosomes previously described in the populations from southeastern Brazil. Giemsa staining, C-banding and DAPI/CMA3 fluorochrome staining also revealed a remarkable interpopulational divergence regarding both the regular karyotype and the B chromosomes. The B chromosomes found in the samples from Jequié, Bahia, were entirely heterochromatic, while those found in Cravolândia, Bahia, displayed a euchromatic portion at the telomeric end of the long arm. CMA 3 labeling sites varied from seven to eight between the two localities in Bahia, due to the presence of an extra GC-rich block in the karyotype of the samples from Jequié. This is the first report of a large B chromosome in P. helleri and reveals the occurrence of a geographic differentiation within this species

Agro-climate tools for a new climate-smart agriculture

The way we produce food must adapt to a variable and changing climate. And key to achieving this is to improve the link between climate information and agricultural practices, especially those of smallholder farmers in developing countries. ‘Agro-climate tools’ do just that and some are introduced here

Growth hormone as concomitant treatment in severe fibromyalgia associated with low IGF-1 serum levels. A pilot study

<p>Abstract</p> <p>Background</p> <p>There is evidence of functional growth hormone (GH) deficiency, expressed by means of low insulin-like growth factor 1 (IGF-1) serum levels, in a subset of fibromyalgia patients. The efficacy of GH versus placebo has been previously suggested in this population. We investigated the efficacy and safety of low dose GH as an adjunct to standard therapy in the treatment of severe, prolonged and well-treated fibromyalgia patients with low IGF-1 levels.</p> <p>Methods</p> <p>Twenty-four patients were enrolled in a randomized, open-label, best available care-controlled study. Patients were randomly assigned to receive either 0.0125 mg/kg/d of GH subcutaneously (titrated depending on IGF-1) added to standard therapy or standard therapy alone during one year. The number of tender points, the Fibromyalgia Impact Questionnaire (FIQ) and the EuroQol 5D (EQ-5D), including a Quality of Life visual analogic scale (EQ-VAS) were assessed at different time-points.</p> <p>Results</p> <p>At the end of the study, the GH group showed a 60% reduction in the mean number of tender points (pairs) compared to the control group (p < 0.05; 3.25 ± 0.8 <it>vs</it>. 8.25 ± 0.9). Similar improvements were observed in FIQ score (p < 0.05) and EQ-VAS scale (p < 0.001). There was a prompt response to GH administration, with most patients showing improvement within the first months in most of the outcomes. The concomitant administration of GH and standard therapy was well tolerated, and no patients discontinued the study due to adverse events.</p> <p>Conclusion</p> <p>The present findings indicate the advantage of adding a daily GH dose to the standard therapy in a subset of severe fibromyalgia patients with low IGF-1 serum levels.</p> <p>Trial Registration</p> <p>NCT00497562 (ClinicalTrials.gov).</p

Estimation of changes in the force of infection for intestinal and urogenital schistosomiasis in countries with Schistosomiasis Control Initiative-assisted programmes

The last decade has seen an expansion of national schistosomiasis control programmes in Africa based on large-scale preventative chemotherapy. In many areas this has resulted in considerable reductions in infection and morbidity levels in treated individuals. In this paper, we quantify changes in the force of infection (FOI), defined here as the per (human) host parasite establishment rate, to ascertain the impact on transmission of some of these programmes under the umbrella of the Schistosomiasis Control Initiative (SCI)

Effects of whey protein supplement in the elderly submitted to resistance training:systematic review and meta-analysis

Aim: We performed a systematic review to map the evidence and analyze the effect of whey protein supplementation in the elderly submitted to resistance training.  Methods: A comprehensive search on Medline, LILACS, EMBASE, and the Cochrane Library for relevant publications was conducted until August 2015. The terms used in the search were: “Resistance training”; “Whey protein”; “Elderly”.  Results: A total of 632 studies were screened. Five studies were included composing a sample of 391 patients. The supplement whey protein was associated with higher total protein ingestion 9.40 (95% CI: 4.03–14.78), and with an average change in plasma leucine concentration. The supplementation was also associated with increased mixed muscle protein synthesis 1.26 (95% CI: 0.46–2.07) compared to the control group.  Conclusion: We observed an increase in total protein intake, resulting in increased concentration of leucine and mixed muscle protein fractional synthesis rate

Natalizumab affects T-cell phenotype in multiple sclerosis: implications for JCV reactivation

The anti-CD49d monoclonal antibody natalizumab is currently an effective therapy against the relapsing-remitting form of multiple sclerosis (RRMS). Natalizumab therapeutic efficacy is limited by the reactivation of the John Cunningham polyomavirus (JCV) and development of progressive multifocal leukoencephalopathy (PML). To correlate natalizumab-induced phenotypic modifications of peripheral blood T-lymphocytes with JCV reactivation, JCV-specific antibodies (serum), JCV-DNA (blood and urine), CD49d expression and relative abundance of peripheral blood T-lymphocyte subsets were longitudinally assessed in 26 natalizumab-treated RRMS patients. Statistical analyses were performed using GraphPad Prism and R. Natalizumab treatment reduced CD49d expression on memory and effector subsets of peripheral blood T-lymphocytes. Moreover, accumulation of peripheral blood CD8+ memory and effector cells was observed after 12 and 24 months of treatment. CD4+ and CD8+ T-lymphocyte immune-activation was increased after 24 months of treatment. Higher percentages of CD8+ effectors were observed in subjects with detectable JCV-DNA. Natalizumab reduces CD49d expression on CD8+ T-lymphocyte memory and effector subsets, limiting their migration to the central nervous system and determining their accumulation in peripheral blood. Impairment of central nervous system immune surveillance and reactivation of latent JCV, can explain the increased risk of PML development in natalizumab-treated RRMS subjects

Vitamin E (α-tocopherol) supplementation in diabetic rats: effects on the proximal colon

<p>Abstract</p> <p>Background</p> <p>Neuropathy is one of the complications caused by diabetes mellitus which is directly related to the gastrointestinal manifestations of the disease. Antioxidant substances, such as vitamin E, may play an important role in the reduction of the neurological damage caused by diabetes mellitus. The aim of the present study was to determine whether vitamin E (α-tocopherol) at different concentrations induces any effects on the morphology of the intestinal wall and intrinsic innervation in the proximal colon of diabetic rats.</p> <p>Methods</p> <p>Thirty rats (90-day-old) were assigned to the following groups: N (normoglycemic), NE1 (normoglycemic supplemented with vitamin E 0.1%), NE2 (normoglycemic supplemented with vitamin E 2%), D (diabetic), DE1 (diabetic supplemented with vitamin E 0.1%), and DE2 (diabetic supplemented with vitamin E 2%). Animals received vitamin E supplementation for 120 days and were sacrificed when they were 210 days old. The proximal colon of each animal was subjected to histology to study the intestinal wall and goblet cells and processed for whole-mount preparations to morphoquantitatively determine the total myenteric population.</p> <p>Results</p> <p>Supplementation with vitamin E significantly reduced glycemia and glycated hemoglobin values and preserved the number of myenteric neurons in group DE2, without affecting intestinal area or thickness of the intestinal wall or muscular tunic.</p> <p>Conclusion</p> <p>Vitamin E (2%) influenced the glycemic parameters and had a neuroprotective effect on the total myenteric population, but the morphometric characteristics of the intestinal wall were unaffected.</p

Potential of Waste Tea Leaves (Camellia sinensis) in West Sumatra to Be Processed into Poultry Feed

Background and Objective: West Sumatra is the third largest tea-producing area in Indonesia. Tea plantations in this area produce top quality leaves that can be marketed both domestically and internationally. To maintain a high level of tea leaf productivity, plants should be pruned every 3 years using a rotation system that involves monthly prunings. These prunings produce waste tea leaves that can serve as alternative feed resource for poultry as they have good nutritional value. Tea leaves contain high concentrations of antioxidants, such as polyphenols and policosanol as well as minerals and vitamins, which are known to improve poultry health. Unfortunately, tea leaves also contain high levels of tannins and crude fiber-components known to be detrimental to poultry. This study was designed to evaluate the potential of waste tea leaves (Camellia sinensis) as poultry feed in West Sumatra by reducing their tannin content through immersion in fresh and hot water. Materials and Methods: This research consisted of two phases. The first phase was a survey of the potential of waste tea leaves as poultry feed through interviews and measurement of waste tea leaf production. The second phase was to experimentally process waste tea leaves through immersion in fresh and hot water. Variables measured during phase 1 included the size of tea plantations, ownerships, tea varieties produced, waste tea leaf production and estimated potential for poultry feed. The experiment conducted in phase 2 was performed using a completely randomized design involving 2×4 factorial arrangement of treatments with 4 replicates. The first experimental variable was water temperature (room temperature or 80EC). The second experimental variable was based on immersion at 6, 12, 18 or 24 h. Response variables measured included change in tannin content, dry matter (DM), organic matter (OM), crude protein (CP) and crude fiber (CF). Results: The results of the first phase indicated that the area of tea plantations in West Sumatra was 4,246.6 ha, ownership consisted of small holders (2,172 ha), the government (604.58 ha) and a private company (1,470 ha), total waste tea leaf production was 25,208.28 t/year, tea varieties or clones were Camellia sinensis assamica TRI 2024 and assamica TRI 2025 and waste tea leaves had the potential to feed 4,201,380,000 laying hens. The results of the second phase indicated that there was an interaction between water temperature and immersion duration on tannin reduction (p<0.05). Water temperature significantly influenced (p<0.01) reductions in OM and CP content and significantly affected (p<0.05) CF augmentation. Immersion duration significantly affected (p<0.05) DM reductions and highly significantly influenced (p<0.01) reductions in OM and CP. Conclusion: Waste tea leaves can be immersed in hot water (80EC) for 12 h to reduce their tannin content without affecting their protein content