Bosonic Reduction of Susy Generalized Harry Dym Equation

In this paper we construct the two component supersymmetric generalized Harry Dym equation which is integrable and study various properties of this model in the bosonic limit. In particular, in the bosonic limit we obtain a new integrable system which, under a hodograph transformation, reduces to a coupled three component system. We show how the Hamiltonian structure transforms under a hodograph transformation and study the properties of the model under a further reduction to a two component system. We find a third Hamiltonian structure for this system (which has been shown earlier to be a bi-Hamiltonian system) making this a genuinely tri-Hamiltonian system. The connection of this system to the modified dispersive water wave equation is clarified. We also study various properties in the dispersionless limit of our model.Comment: 21 page

Time Delay Effects on Coupled Limit Cycle Oscillators at Hopf Bifurcation

We present a detailed study of the effect of time delay on the collective dynamics of coupled limit cycle oscillators at Hopf bifurcation. For a simple model consisting of just two oscillators with a time delayed coupling, the bifurcation diagram obtained by numerical and analytical solutions shows significant changes in the stability boundaries of the amplitude death, phase locked and incoherent regions. A novel result is the occurrence of amplitude death even in the absence of a frequency mismatch between the two oscillators. Similar results are obtained for an array of N oscillators with a delayed mean field coupling and the regions of such amplitude death in the parameter space of the coupling strength and time delay are quantified. Some general analytic results for the N tending to infinity (thermodynamic) limit are also obtained and the implications of the time delay effects for physical applications are discussed.Comment: 20 aps formatted revtex pages (including 13 PS figures); Minor changes over the previous version; To be published in Physica

Database Species-Area Relationships in Palaearctic Grasslands.

The database collects the data resulting from the sampling of species-area relationships (SARs) in grassland communities in the Palaearctic. The core features of the database are the complete data from the EDGG Research Expeditions, but similar data from other studies are also included. Main features of the majority of relevés are: (i) they are part of nested-plot series (typically 0.0001-100 m²), (ii) bryophytes and lichens are treated comprehensively; (iii) detailed soil and other environmental data

Scale-dependent plant diversity in Palaearctic grasslands: a comparative overview

Here we present an extensive overview of plant diversity values in Palaearctic grasslands for seven standard grain sizes from 0.0001 to 100 m². The data originate from 20 studies, including the Field Workshops of the Eurasian Dry Grassland Group (EDGG), ranging geographically from Spain in the west to Siberia in the east, from Sicily in the south to Estonia in the north and from the sea coast up to 3100 m a.s.l. The majority of data is from dry grasslands (Festuco-Brometea, Koelerio-Corynephoretea, Cleistogenetea squarrosae), but there are also some mesic, wet, saline, acidic, alpine and Mediterranean grasslands included. Among others, we compiled data from 1795 1-m², 1109 10-m² and 338 100-m² plots. In all cases we present mean, minimum and maximum richness for the seven grain sizes, plus, in cases where also terricolous bryophytes and lichens had been recorded, the same values for total “plant” species richness, non-vascular plant species richness and fraction of non-vascular plants. The maximum richness values were 82, 101 and 134 for all “plants”, and 79, 98 and 127 vascular plants at grain sizes of 1 m², 10 m² and 100 m², respectively (all in Transylvania, Romania). Our overview comprises new, hitherto unpublished world records of vascular plant species richness at the scales of 0.0001 m² (9) and 0.001 m² (19, both shoot presence), from meso-xeric, basiphilous grasslands in Navarre, Spain, which is much higher than the previously known maxima. The highest values of non-vascular plant richness at 1 m², 10 m² and 100 m², respectively, were 49, 64 and 64, respectively (all in Sedo-Scleranthenea communities of Öland, Sweden, and Saaremaa, Estonia). In general, the dry, alpine and Mediterranean grasslands were much richer than the studied mesic, wet or saline grasslands at any spatial scale. The presented set of mean, minimum and maximum values and their metadata is publically available and will be continuously updated. These data can serve as a reference of “normal” richness, both in fundamental and applied research. To facilitate the application, we provide an easy formula based on the power-law species-area relationship that allows the estimation of richness values at intermediate grain sizes not included in our dataset. In conclusion, our data emphasise the role of Palaearctic grasslands as global hotspot of small-scale vascular plant diversity, while at the same time highlighting that in some grassland types also the bryophyte and lichen diversity can be extraordinarily high

The design and function of birds’ nests

All birds construct nests in which to lay eggs and/or raise offspring. Traditionally, it was thought that natural selection and the requirement to minimize the risk of predation determined the design of completed nests. However, it is becoming increasingly apparent that sexual selection also influences nest design. This is an important development as while species such as bowerbirds build structures that are extended phenotypic signals whose sole purpose is to attract a mate, nests contain eggs and/or offspring, thereby suggesting a direct tradeoff between the conflicting requirements of natural and sexual selection. Nest design also varies adaptively in order to both minimize the detrimental effects of parasites and to create a suitable microclimate for parents and developing offspring in relation to predictable variation in environmental conditions. Our understanding of the design and function of birds’ nests has increased considerably in recent years, and the evidence suggests that nests have four nonmutually exclusive functions. Consequently, we conclude that the design of birds’ nests is far more sophisticated than previously realized and that nests are multifunctional structures that have important fitness consequences for the builder/s

Lectin-Dependent Enhancement of Ebola Virus Infection via Soluble and Transmembrane C-type Lectin Receptors

Mannose-binding lectin (MBL) is a key soluble effector of the innate immune system that recognizes pathogen-specific surface glycans. Surprisingly, low-producing MBL genetic variants that may predispose children and immunocompromised individuals to infectious diseases are more common than would be expected in human populations. Since certain immune defense molecules, such as immunoglobulins, can be exploited by invasive pathogens, we hypothesized that MBL might also enhance infections in some circumstances. Consequently, the low and intermediate MBL levels commonly found in human populations might be the result of balancing selection. Using model infection systems with pseudotyped and authentic glycosylated viruses, we demonstrated that MBL indeed enhances infection of Ebola, Hendra, Nipah and West Nile viruses in low complement conditions. Mechanistic studies with Ebola virus (EBOV) glycoprotein pseudotyped lentiviruses confirmed that MBL binds to N-linked glycan epitopes on viral surfaces in a specific manner via the MBL carbohydrate recognition domain, which is necessary for enhanced infection. MBL mediates lipid-raft-dependent macropinocytosis of EBOV via a pathway that appears to require less actin or early endosomal processing compared with the filovirus canonical endocytic pathway. Using a validated RNA interference screen, we identified C1QBP (gC1qR) as a candidate surface receptor that mediates MBL-dependent enhancement of EBOV infection. We also identified dectin-2 (CLEC6A) as a potentially novel candidate attachment factor for EBOV. Our findings support the concept of an innate immune haplotype that represents critical interactions between MBL and complement component C4 genes and that may modify susceptibility or resistance to certain glycosylated pathogens. Therefore, higher levels of native or exogenous MBL could be deleterious in the setting of relative hypocomplementemia which can occur genetically or because of immunodepletion during active infections. Our findings confirm our hypothesis that the pressure of infectious diseases may have contributed in part to evolutionary selection of MBL mutant haplotypes

Filovirus RefSeq Entries: Evaluation and Selection of Filovirus Type Variants, Type Sequences, and Names

Sequence determination of complete or coding-complete genomes of viruses is becoming common practice for supporting the work of epidemiologists, ecologists, virologists, and taxonomists. Sequencing duration and costs are rapidly decreasing, sequencing hardware is under modification for use by non-experts, and software is constantly being improved to simplify sequence data management and analysis. Thus, analysis of virus disease outbreaks on the molecular level is now feasible, including characterization of the evolution of individual virus populations in single patients over time. The increasing accumulation of sequencing data creates a management problem for the curators of commonly used sequence databases and an entry retrieval problem for end users. Therefore, utilizing the data to their fullest potential will require setting nomenclature and annotation standards for virus isolates and associated genomic sequences. The National Center for Biotechnology Information’s (NCBI’s) RefSeq is a non-redundant, curated database for reference (or type) nucleotide sequence records that supplies source data to numerous other databases. Building on recently proposed templates for filovirus variant naming [ ()////-], we report consensus decisions from a majority of past and currently active filovirus experts on the eight filovirus type variants and isolates to be represented in RefSeq, their final designations, and their associated sequences

Taxonomy of the order Mononegavirales : update 2016

In 2016, the order Mononegavirales was emended through the addition of two new families (Mymonaviridae and Sunviridae), the elevation of the paramyxoviral subfamily Pneumovirinae to family status (Pneumoviridae), the addition of five free-floating genera (Anphevirus, Arlivirus, Chengtivirus, Crustavirus, and Wastrivirus), and several other changes at the genus and species levels. This article presents the updated taxonomy of the order Mononegavirales as now accepted by the International Committee on Taxonomy of Viruses (ICTV)

Upotreba koncentrata dušika iz krumpira u proizvodnji α-amilaze s pomoću plijesni Aspergillus oryzae

The influence of various nitrogen sources and media supplements on α-amylase (EC 3.2.1.1) formation by Aspergillus oryzae ATCC 1011 was investigated in shake flask experiments and batch fermentations. Both inorganic and organic nitrogen-containing supplements have been applied, while corn starch and ammonium sulphate were used as the major source of carbon and nitrogen, respectively. Shake flask experiments revealed that potato nitrogen concentrate (PNC) is almost equivalent to corn steep liquor (CSL) in supporting amylase formation. A pretreatment step consisting of clarification of the turbid material did not show any significant effect. The replacement of the inorganic nitrogen source by sodium nitrate led to lower enzyme yields. Other complex supplements may reduce the enzyme level formed, e.g. casein hydrolysate, or increase the amylase titre slightly, e.g. yeast extract or malt extract. Cultivations in instrumented bench top reactors on media supplemented with PNC led to higher cell growth rates and yields of α-amylase in comparison with the medium without any supplement. Replacement of PNC by CSL revealed a slightly increased enzyme level, which is in the range of 9–17 % after 100 h of cultivation. Only minor differences were revealed in the growth kinetics and enzyme formation when PNC was used as the sole nitrogen source, replacing a mixture of soybean meal, yeast extract, malt extract and casein hydrolysate in bioreactor cultivations with lactose as the carbon source. However, metabolic differences as seen from the course of dissolved oxygen tension (DOT), α-amino nitrogen concentration and the amount of acid needed to maintain a constant pH were observed.Istražen je utjecaj različitih izvora dušika i dodataka podlozi na proizvodnju α-amilaze (EC 3.2.1.1) s pomoću plijesni Aspergillus oryzae ATCC 1011 u pokusu na tresilici i šaržnim uzgojem. Primijenjeni su anorganski i organski dušikovi spojevi, a kao glavni izvori ugljika i dušika korišteni su kukuruzni škrob i amonijev sulfat. Pokusima na tresilici dokazano je da je utjecaj koncentrata dušika iz krumpira (potato nitrogen concentrate – PNC) na proizvodnju amilaze skoro jednak onom ekstrakta kukuruza (corn steep liquor – CSL). Pročišćavanjem zamućenog materijala prije obrade nije se postigao značajan učinak. Zamjenom anorganskog izvora dušika natrijevim nitratom dobiveni su manji prinosi enzima. Dodatkom drugih kompleksnih spojeva, kao što je hidrolizat kazeina, smanjio se prinos enzima, a dodatkom ekstrakta kvasca ili slada neznatno se povećao titar amilaze. Veći rast stanica i bolji prinos α-amilaze postignut je uzgojem na podlozi obogaćenoj s PNC u reaktoru na postolju nego bez tih dodataka. Zamjenom PNC sa CSL postignuto je povećanje prinosa enzima za 9-17 % nakon 100 sati uzgoja. Upotreba PNC kao jedinog izvora dušika, uz zamjenu sojine kaše, ekstrakta kvasca i slada te hidrolizata kazeina laktozom kao izvorom ugljika, dovela je do neznatnih razlika u kinetici rasta i formiranju enzima u bioreaktoru. Međutim, uočene su metaboličke razlike u zasićenosti otopljenim kisikom (dissolved oxygen tension – DOT), koncentraciji α-amino dušika i količini kiseline potrebne za održavanje konstantnog pH