Communities and beyond: mesoscopic analysis of a large social network with complementary methods

Community detection methods have so far been tested mostly on small empirical networks and on synthetic benchmarks. Much less is known about their performance on large real-world networks, which nonetheless are a significant target for application. We analyze the performance of three state-of-the-art community detection methods by using them to identify communities in a large social network constructed from mobile phone call records. We find that all methods detect communities that are meaningful in some respects but fall short in others, and that there often is a hierarchical relationship between communities detected by different methods. Our results suggest that community detection methods could be useful in studying the general mesoscale structure of networks, as opposed to only trying to identify dense structures.Comment: 11 pages, 10 figures. V2: typos corrected, one sentence added. V3: revised version, Appendix added. V4: final published versio

Yield and chemical composition of plant parts of silage maize (Zea mays L) hybrids and their interest for biogas production

Silage maize (Zea mays L) hybrids bred in Martonvásár were tested for morphological traits, yield and chemical composition of the whole plant and the plant parts in three years (2010-2012). Biogas production of the hybrids was investigated in 2009 and 2010. The dry matter, protein, starch, water soluble carbohydrates, neutral detergent fibre, acid detergent fibre, lignin and in vitro digestible organic matter contents were measured by NIR spectroscopy. The ratio of ear attachment height to plant height was smaller, the leaf number above the ear and the proportion of the leaves in the total plant dry matter was greater for leafy hybrids. It was concluded that the differences in the chemical composition of the parts of the same genotype were greater than between the same parts of different genotypes. The leaves had the greatest protein content. The starch and WSC content in the ear was significantly higher than in the other plant parts. The ear had the lowest lignin content and the highest IVDOM content compared to other plant parts. NDF and ADF contents were greatest in the stalk below the ear. Significant differences were found for WSC content of the plant parts of leafy and non-leafy hybrids. Digestible dry matter yield (DDMY) was calculated from individual dry matter production, plant number per hectare and digestible organic matter content. The highest DDMY value was recorded for Siloking (19.18 t ha-1). Biogas yield was highest for Mv Massil (659 l kg-1 DM) with 61.38% methane concentration. Leafy hybrids produced significantly more biogas than conventional hybrids. Biogas yield proved to have significant positive correlations with starch and WSC content, and negative correlations with protein and lignin content

Yolk androstenedione, but not testosterone, predicts offspring fate and reflects parental quality

Yolk androgen deposition is a widely investigated maternal effect in birds, but its adaptive value is at present unclear. The offspring fitness correlates of natural yolk androgen levels are virtually unknown, whereas manipulations largely focused on testosterone and neglected other androgens. We determined yolk concentrations of the 2 dominant androgens, androstenedione and testosterone, from all eggs in collared flycatcher clutches and followed the fate of individual offspring from these eggs in a crossfostering experiment. Yolk concentration of androstenedione was much higher than that of testosterone. Offspring from eggs with relatively higher androstenedione concentrations within a clutch were relatively large after hatching, grew slower thereafter, and had a higher recruitment rate in subsequent years. The increase of androstenedione with laying order and its within-clutch variance were negatively correlated with a condition-dependent female ornament, perhaps indicating compensatory hormone deposition into later hatching eggs by females in low condition. Yolk testosterone variation within or among clutches was not related to any measured aspect of offspring or parental quality. Our results suggest that in some species, especially those with much more androstenedione than testosterone in the yolk, androstenedione and not testosterone may be the yolk androgen with a long-term function and adaptive deposition pattern.</p

Utilizing Leafy genes as resources in quality silage maize breeding

The primary goal of silage maize production is to obtain the greatest possible amount of digestible nutrients. Although it is not of the highest value in terms of starch, leaves provide ruminants with sufficient amount of green mass and facilitate nutrient uptake. The nutrient and fibre content of leaves at harvest affect the quality of silage. In cooperation with Glenn Seed Ltd, the Agricultural Research Institute of HAS had an opportunity to use an inbred line carrying the dominant allele Leafy1 (Lfy1). The number and surface area of leaves were measured in various hybrid combinations, and the hybrids and parents were compared morphologically. The combinations causing the highest heterosis were identified. Compared to lines without Lfy1 gene and hybrids in the same maturity group, these lines had an additional 3-4 leaves above the ear on average, resulting in an extra 30-40% leaf area. The hybrid Siloking (Lfy) produced 50% more leaves above the ear than the standard, leading to an extra 40% leaf area. The results demonstrate that the increased total leaf area of Lfy silage hybrids and the number of leaves above the ear, ensure that new leaves with high sugar content capable of photosynthesizing can develop until the end of grain filling. The increased leaf-mass produced by Lfy hybrids may be utilized, bearing in mind the relevant guidelines by the European Union, also as biogas raw material in sustainable energy management

Type I Interferon Production Induced by Streptococcus pyogenes-Derived Nucleic Acids Is Required for Host Protection

Streptococcus pyogenes is a Gram-positive human pathogen that is recognized by yet unknown pattern recognition receptors (PRRs). Engagement of these receptor molecules during infection with S. pyogenes, a largely extracellular bacterium with limited capacity for intracellular survival, causes innate immune cells to produce inflammatory mediators such as TNF, but also type I interferon (IFN). Here we show that signaling elicited by type I IFNs is required for successful defense of mice against lethal subcutaneous cellulitis caused by S. pyogenes. Type I IFN signaling was accompanied with reduced neutrophil recruitment to the site of infection. Mechanistic analysis revealed that macrophages and conventional dendritic cells (cDCs) employ different signaling pathways leading to IFN-beta production. Macrophages required IRF3, STING, TBK1 and partially MyD88, whereas in cDCs the IFN-beta production was fully dependent on IRF5 and MyD88. Furthermore, IFN-beta production by macrophages was dependent on the endosomal delivery of streptococcal DNA, while in cDCs streptococcal RNA was identified as the IFN-beta inducer. Despite a role of MyD88 in both cell types, the known IFN-inducing TLRs were individually not required for generation of the IFN-beta response. These results demonstrate that the innate immune system employs several strategies to efficiently recognize S. pyogenes, a pathogenic bacterium that succeeded in avoiding recognition by the standard arsenal of TLRs

Innate Immune Response to Streptococcus pyogenes Depends on the Combined Activation of TLR13 and TLR2

International audienceInnate immune recognition of the major human-specific Gram-positive pathogen Strepto-coccus pyogenes is not understood. Here we show that mice employ Toll-like receptor (TLR) 2-and TLR13-mediated recognition of S. pyogenes. These TLR pathways are non-redundant in the in vivo context of animal infection, but are largely redundant in vitro, as only inactivation of both of them abolishes inflammatory cytokine production by macrophages and dendritic cells infected with S. pyogenes. Mechanistically, S. pyogenes is initially recognized in a phagocytosis-independent manner by TLR2 and subsequently by TLR13 upon in-ternalization. We show that the TLR13 response is specifically triggered by S. pyogenes rRNA and that Tlr13 −/− cells respond to S. pyogenes infection solely by engagement of TLR2. TLR13 is absent from humans and, remarkably, we find no equivalent route for S. pyogenes RNA recognition in human macrophages. Phylogenetic analysis reveals that TLR13 occurs in all kingdoms but only in few mammals, including mice and rats, which are naturally resistant against S. pyogenes. Our study establishes that the dissimilar expression of TLR13 in mice and humans has functional consequences for recognition of S. pyogenes in these organisms