bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of some compounds on gentamicin formation by Micromonospora purpurea
Authors: Abou‐Zeid Abou‐Zeid A. , Eissa Abd El‐Wahab I. , Salem Hassan M. 
Published: March 2011

AbstractProduction of gentamicin antibiotics by Micromonospora purpurea was carried out successfully on a synthetic medium which contained the following ingredients (g/litre): glucose 10.0, NaNO3 2.0, KH2PO4 1.0, and CaCO3 1.0. The initial pH value of the fermentation medium was adjusted to 7.2. Effects of certain amino acids, organic acids, vitamins, purine and pyrimidine bases on the fermentative production of gentamicins were revealed. The ingredients which increased the antibiotic yields were phenylalanine, isoleucine, lysine, methionine, leucine, arginine, glycine, β′‐alanine, cystine, tryptophan, malic acid, maleic acid, cobalamin, folic acid, riboflavin, vitamin B1, vitamin B6, biotin, nicotinamide, uracil, adenine, guanine and adenosine. Trace elements (Co, Mo, Fe, Cu, Zn and Mn) exhibited their important role on the biosynthesis and formation of gentamicins by Micromonospora purpurea.
Multivariate analysis of soils: microbial biomass, metabolic activity, and bacterial‐community structure and their relationships with soil depth and type
Authors: Gelsomino Antonio , Azzellino Arianna 
Published: March 2011

AbstractA multivariate statistical approach based on a large data set of abiotic and biotic variables was used to classify four contrasting‐land‐use soils. Soil samples were collected at increasing depth from a calcareous agricultural soil, a temperate upland grassland soil, a moderately acidic agricultural soil, and an acidic pine forest soil. Analytical investigations were carried out by using a combination of conventional physical, chemical, and biochemical methods coupled with denaturing gradient gel electrophoresis (DGGE) community fingerprinting of PCR‐amplified 16S rRNA gene‐coding fragments from soil‐extracted total‐community DNA. The data set of soil physical, chemical, and biochemical variables was reduced in dimensionality by means of a principal‐component‐analysis (PCA) procedure. Compositional shifts in soil bacterial‐community structure were analyzed through a clustering algorithm that allowed identifying six main bacterial‐community clusters. DGGE fingerprinting clusters were further analyzed by discriminant analysis (DA) using extracted PCA components as explanatory variables. Soil organic matter–related pools (TOC, TN) and functionally related active pools (microbial biomass C and N, K2SO4‐extractable C) significantly decreased with soil depth, and resulted statistically linked to one other and positively related to enzymatic activities (acid phosphatase, arylsulfatase, β‐glucosidase, dehydrogenase, hydrolysis of fluorescein diacetate) and silt content. Besides organic‐C gradients, pedogenetic‐driven physico‐chemical properties, and possibly soil thermal and moisture regimes seemed to play a key role in regulating size and energetic ecophysiological status of soil microbial communities. DGGE analysis showed that contrasting horizons were conducive to the dominance of particular bacterial ribotypes. DA revealed that the bacterial‐community structure was mainly influenced by organic matter–related variables (TOC, TN, CEC, Cflush, Nflush, Extr‐C), chemical properties such as pH, CaCO3, and EC, together with textural properties. Results indicate that, beyond land use or plant cover, pedogenetic‐driven physico‐chemical conditions changing with soil type and depth are the key factors regulating microbial size and activity, and determining the genetic structure of bacterial community.
Sterols in soil organic matter in relation to nitrogen mineralization in sandy arable soils
Authors: Heumann Sabine , Schlichting André , Böttcher Jürgen , Leinweber Peter 
Published: March 2011

AbstractUnusually low net N mineralization in soils relatively rich in total organic C and N was repeatedly reported for sandy arable soils in NW Europe. In order to adequately account for it in simulation models, it is necessary to know the involved substances and processes. Therefore, 9 arable top soils (< 6% clay) with a wide range of total organic C (1.1%–5.2%) and C : N ratios (12–35) were studied. The soils varied strongly in the mineralizability of soil organic N which was determined via long‐term laboratory incubations (> 200 d). It was hypothesized that mineralization was controlled by antioxidants, and the Trolox equivalent antioxidant capacity (TEAC) of the soils was measured. In addition, pyrolysis–field ionization mass spectrometry (Py‐FIMS) was applied to investigate the influence of the molecular‐chemical composition of soil organic matter. In these soils, the compound class of sterols from Py‐FIMS analysis was most closely, negatively correlated with the mineralizability of soil organic N (r<?h.3>2 = 0.75, p = 0.003). This was probably not an antioxidative effect, because the TEAC values did not correlate sufficiently with the mineralizability and the sterol intensities. However, the negative relation with sterols could be causal, since the correlation was about as close with other components of the compound class of sterols and even closer with the main plant sterol beta‐sitosterol (r<?h.3>2 = 0.84, p = 0.001). In addition, the variability among samples was strongly governed by the proportions of sterols, and sterols also had a high discriminating power in discriminant analysis. Furthermore, the proportions of sterols were extraordinary in those arable podzol soils that developed under previous heath‐ or woodland (up to 10.2% of total ion intensity from Py‐FIMS). In conclusion, the inhibitory effect of these compounds needs to be investigated in more detail in order to optimize parameterization of N as well as C simulation models especially for podzolized, sandy arable soils with former heath‐ or woodland vegetation.
Phosphorus partitioning in grassland and forest soils of Germany as related to land‐use type, management intensity, and land use–related pH
Authors: Alt Fabian , Oelmann Yvonne , Herold Nadine , Schrumpf Marion , Wilcke Wolfgang 
Published: March 2011

AbstractRecent literature confirmed that P fractions in soil are controlled by land use. However, differences in intensity of the same type of land use have received less attention although management intensity plays a crucial role in determining nutrient supply in soil. The objective of our work was to assess the influence of land‐use intensity (LUI) on P fractions in soil. In the “Biodiversity Exploratories”, grassland and forest sites in Germany were selected in three regions (Schorfheide‐Chorin, Hainich‐Dün, Schwäbische Alb). In spring 2008, we sampled topsoil of 241 experimental plots. The plots included unfertilized and fertilized meadows, pastures, and mown pastures and near‐natural to intensively used forests. Land‐use intensity was classified according to the extent of annual biomass removal. We used the sequential extraction method of Hedley et al. (1982) to characterize P partitioning in soil. In summary, total P (TP) concentrations in soil were lowest at Schorfheide‐Chorin (62–952 mg kg–1) followed by the Hainich‐Dün (230–1631 mg kg–1) and the Schwäbische Alb (205–1838 mg kg–1). Differences between grassland and forest sites were mainly attributable to pH. The pH value was the most important factor among several soil properties explaining P partitioning in soil. For grassland, at pH values ≈ 6.5, the application of lime‐containing fertilizer increased P availability in soil while effects of organic or mineral P fertilizers were negligible and related to the low application rates (< 12 kg ha–1). Land‐use intensity contributed up to 10% of the variation in the contribution of NaOH‐Pi to TP concentrations (ANOVA, Type I). In the Schwäbische Alb grassland soils, elevated LUI resulted in low NaOH‐Pi concentrations in soil which was probably caused by reduced sorption. Our findings highlight the importance of LUI as a control of P fractions in soil.
Influence of earthworm culture on fertilization potential and biological activities of vermicomposts prepared from different plant wastes
Authors: Kumar Srivastava Pankaj , Singh Poonam C. , Gupta Manjul , Sinha Arpita , Vaish Aradhana , Shukla Ashish , Singh Nandita , Krishna Tewari Sri 
Published: March 2011

AbstractThe present investigation was aimed to analyze influence of earthworm culture on nutritive status, microbial population, and enzymatic activities of composts prepared by utilizing different plant wastes. Vermicomposts were prepared from different types of leaves litter of horticulture and forest plant species by modified vermicomposting process at a farm unit. Initial thermophilic decomposition of waste load using cow‐dung slurry was done in the separate beds. The culture of Eisenia fetida was used for vermicomposting in specially designed vermibeds at the farm unit. The physico‐chemical characteristics, enzyme activities (oxido‐reductases and hydrolases), and microbial population (bacteria, fungi, free‐living nitrogen‐fixing bacteria, actinomycetes, Bacillus, Pseudomonas, phosphate‐solubilizing bacteria and fungi) of vermicomposts were found significantly higher (p < 0.05) than those of control (without earthworm inoculum). The study quantified significant contributions of earthworm culture to physico‐chemical, enzymatic, and microbiological properties of vermicompost and confirmed superior fertilization potential of vermicompost for organic farming. The agronomic utility of vermicompost was assessed on yellow mustard plant in a pot experiment. Pot soil was amended with different ratios (5%, 10%, 20%) of vermicompost and normal compost (without earthworm inoculum). Effects of these amendments on the growth of Brassica comprestis L. were studied. The significant differences (p < 0.05) in the growth of plant were observed among vermicompost‐, compost‐amended soil, and control. Vermicompost increased the root and shoot lengths, numbers of branches and leaves per plant, fresh and dry weights per plant, numbers of pods and flowers, and biochemical properties of plant leaf significantly, especially in 20% amendment. These results proved better fertilization potential of vermicompost over non‐earthworm‐inoculated compost.
Comparing concurrent in situ and batch‐extracted trace element concentrations
Authors: Godbersen Levke , Utermann Jens , Duijnisveld Wilhelmus H. M. , Altfelder Sven , Kuhnt Gerald , Böttcher Jürgen 
Published: March 2011

AbstractDifferent procedures to investigate dissolved trace element concentration at the transition from unsaturated to saturated zone in soils were compared by concurrent sampling of soil solution and solid soil material in this zone. The in situ sampled soil solution from the percolated water was used to measure in situ concentrations, while solid soil material was used to measure concentrations at two liquid–solid ratios using batch experiments on 250 sample pairs. The liquid–solid ratios were 2 L kg–1 and 5 L kg–1. At 5 L kg–1, the ionic strength was adjusted with Ca(NO3)2 to a sample‐specific value similar to in situ, while at 2 L kg–1, the ionic strength was not adjusted. The extracted concentrations of most trace elements exhibited a statistically significant but weak correlation (p value < 0.01) to the corresponding in situ concentrations. In the liquid–solid ratio of 2 L kg–1 extracts, Pb and Cr showed very poor comparability with the in situ equivalent. A likely cause was the enhanced dissolved‐organic‐C release in the extract due to the lower ionic strength compared to in situ conditions in combination with effects from drying and moistening soil samples. For the other elements, correlation increased in the order As < Cu, Zn, Sb, Mo, V < Cd, Ni, Co where adjustment of the ionic strength led to slightly better results. In addition to the element‐specific shortcomings, it appeared that low concentration levels of in situ concentrations were generally underestimated by batch extraction methods. The liquid–solid ratio of 2 L kg–1 extracts could only be used as a method to predict exceedance of thresholds if a safety margin of approximately one order of magnitude higher than the thresholds was adopted. The ability of the batch‐extraction methods to estimate in situ concentrations was equally limited.
Degenerate elliptic operators, Feller semigroups and modified Bernstein‐Schnabl operators
Authors: Altomare Francesco , Montano Mirella Cappelletti , Diomede Sabrina 
Published: March 2011

AbstractIn this paper we study a class of elliptic second‐order differential operators on finite dimensional convex compact sets whose principal part degenerates on a subset of the boundary of the domain. We show that the closures of these operators generate Feller semigroups.Moreover, we approximate these semigroups by iterates of suitable positive linear operators which we also introduce and study in this paper for the first time, and which we refer to as modified Bernstein‐Schnabl operators. As a consequence of this approximation we investigate some regularity properties preserved by the semigroup.Finally, we consider the special case of the finite dimensional simplex and the well‐known Wright‐Fisher diffusion model of gene frequency used in population genetics. © 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim
Homozygous THAP1 mutations as cause of early‐onset generalized dystonia
Authors: Schneider Susanne A. , Ramirez Alfredo , Shafiee Kaveh , Kaiser Frank J. , Erogullari Alev , Brüggemann Norbert , Winkler Susen , Bahman Ideh , Osmanovic Alma , Shafa Mohammad A. , Bhatia Kailish P. , Najmabadi Hossein , Klein Christine , Lohmann Katja 
Published: March 2011

AbstractTo identify the underlying genetic cause in a consanguineous family with apparently recessively inherited dystonia, we performed genome‐wide homozygosity mapping. This revealed 2 candidate regions including the THAP1 gene, where heterozygous mutations cause dystonia 6. A homozygous missense mutation in THAP1 (c.95T>A; p.Leu32His) was found in all 3 affected siblings. Symptoms started in childhood in the legs and became generalized within a few years. Three heterozygous mutation carriers were unaffected. Because THAP1 regulates the expression of the DYT1 gene, we used reporter gene assays to show that DYT1 expression was significantly increased for Leu32His. However, this increase was less pronounced than for other THAP1 mutations that cause dystonia in the heterozygous state. Our data suggest that homozygous THAP1 mutations cause dystonia and may be associated with a less severe dysfunction of the encoded protein compared with heterozygous disease‐causing mutations. © 2011 Movement Disorder Society
Replication of MAPT and SNCA, but not PARK16‐18, as susceptibility genes for Parkinson's disease
Authors: Mata Ignacio F. , Yearout Dora , Alvarez Victoria , Coto Eliecer , de Mena Lorena , Ribacoba Renee , Lorenzo‐Betancor Oswaldo , Samaranch Lluis , Pastor Pau , Cervantes Sebastian , Infante Jon , Garcia‐Gorostiaga Ines , Sierra Maria , Combarros Onofre , Snapinn Katherine W. , Edwards Karen L. , Zabetian Cyrus P. 
Published: March 2011

AbstractRecent genome‐wide association studies of Parkinson's disease have nominated 3 new susceptibility loci (PARK16‐18) and confirmed 2 known risk genes (MAPT and SNCA) in populations of European ancestry. We sought to replicate these findings. We genotyped single‐nucleotide polymorphisms in each of these genes/loci in 1445 Parkinson's disease patients and 1161 controls from northern Spain. Logistic regression was used to test for association between genotype and Parkinson's disease under an additive model, adjusting for sex, age, and site. We also performed analyses stratified by age at onset. Single‐nucleotide polymorphisms in MAPT (rs1800547; P = 3.1 × 10−4) and SNCA (rs356219; P = 5.5 × 10−4) were significantly associated with Parkinson's disease. However, none of the markers in PARK16‐18 associated with Parkinson's disease in the overall sample, or in any age stratum, with P values ranging from .09 to .88. Although our data further validate MAPT and SNCA as Parkinson's disease susceptibility genes, we failed to replicate PARK16, PARK17, and PARK18. Potential reasons for the discordance between our study and previous genome‐wide association studies include effects of population structure, power, and population‐specific environmental interactions. Our findings suggest that additional studies of PARK16‐18 are necessary to establish the role of these loci in modifying risk for Parkinson's disease in European‐derived populations. © 2011 Movement Disorder Society
Identifying extreme event climate thresholds for greater Manchester, UK: examining the past to prepare for the future
Authors: Smith Claire , Lawson Nigel 
Published: March 2011

AbstractExtreme weather events can have severe consequences for the local environment and population. Projected future changes in climate (e.g. UKCP09) indicate that North West England is likely to experience an increasing frequency and intensity of meteorological extremes, leading to flooding, heat waves and storms. Consequently, it is important that the region enhances its preparedness for such events. This paper explores the possibility of developing quantifiable climate risk indices for the case study area of Greater Manchester, using a combination of archival research and statistical analysis of past climate data. For extremes which are the function of a single meteorological variable (e.g. heat waves, pluvial flooding and heavy snowfall) the thresholds proved to be reliable and skillful. Days with maximum daily temperature greater than or equal to 29.2 °C, daily snowfall amount greater than or equal to 6 cm or maximum gust speed greater than or equal to 60 knots are found to be indicative of weather‐related impacts which have in the past affected human health/well‐being, have caused damage to the urban infrastructure or have severely disrupted services. Extreme events which are the result of a more complex interaction between variables (e.g. drought, freezing conditions) were less well captured by applying the thresholds associated with a single variable in isolation. Such critical threshold indices can be used in conjunction with future projections of climate change to establish weather‐related risk for the future. This risk‐based approach can subsequently be integrated to climate change adaptation strategies and development planning to ensure future preparedness. Copyright © 2011 Royal Meteorological Society
Multi‐model ensemble (MME) prediction of rainfall using neural networks during monsoon season in India
Authors: Kumar Ashok , Mitra A. K. , Bohra A. K. , Iyengar G. R. , Durai V. R. 
Published: March 2011

AbstractThe prediction of Asian summer monsoon rainfall on various space and time scales is still a difficult task. Compared to the mid‐latitudes, proportional improvement in the skill in prediction of monsoon rainfall in medium range has been less in recent years. Global models and data assimilation techniques are being further improved for monsoons and the tropics. However, multi‐model ensemble (MME) forecasting is gaining popularity, as it has the potential to provide more information for practical forecasting in terms of making a consensus forecast and reducing the model uncertainties. As major centres are exchanging the model output in near real time, MME is a viable, inexpensive, way for enhancing the forecast skill. Apart from a simple ensemble mean, the MME predictions of large‐scale monsoon precipitation in the medium range was carried out during the 2009 monsoon at NCMRWF/MoES, India. The neural network weights were obtained and a neural network was trained based upon forecast data from four global models for the 2007 and 2008 monsoons in order to develop the multi‐model ensemble system. The skill score for country and sub‐regions, indicates that a multi‐model ensemble forecast has a higher skill than individual model forecasts and also higher skill than the simple ensemble mean in general. Although the skill of the global models falls beyond day 3, a significant improvement could be seen by employing the MME technique up to day 5. Copyright © 2011 Royal Meteorological Society
Rapid merger and recyclogenesis of twin extratropical cyclones leading to heavy precipitation around Japan on 9–10 October 2001
Authors: Yamamoto Masaru 
Published: March 2011

AbstractThe significance of twin extratropical cyclones (in contrast to twin tropical cyclones) has not yet been fully recognized in weather forecasting and analysis of heavy precipitation. This study investigated successive sets of twin extratropical cyclones over the Yellow and East China Seas (YECS) and over the Japan Sea and South Coast areas of the Japanese Islands (JSSC) on 9–10 October 2001. Although these twin cyclones were not strong, they led to heavy precipitation in Japan. The southern low of the YECS twin cyclones, which accompanied a moist tongue, rapidly merged with the northern cold low, resulting in the formation of a moist tongue across the Japanese Islands, causing heavy precipitation. This rapid merger is explained by a coupling of cold upper‐ and warm lower‐level lows in a contact binary rotation system. Subsequently, the JSSC twin cyclones became newly organized. The northern deep low of the JSSC twin cyclones formed north of an upper‐level jet by the merger of the YECS cyclones, while the southern shallow low newly formed around the occlusion point south of the upper‐level jet. The sensitivity experiments of successive sets of the twin cyclones show that condensational heating and topographic effects contribute to the formation of the twin structures. The northern low of the JSSC twin cyclones is amplified by latent heating, while the southern low is hardly amplified. The topography of the Japanese Islands results in intensification of the upward flow and cyclonical flow via topographic convergence and blocking of horizontal flow. Copyright © 2011 Royal Meteorological Society
Printed L‐band monopole antenna with a bionical structure
Authors: Jiang Wen , Gong Shu‐xi , Hong Tao , Mu Xin 
Published: March 2011

AbstractA bionical structure is applied to antenna design in this letter. An L‐band printed monopole antenna using the shape of the octopus is proposed for 1.6 GHz based on the concept of bionics. Its radiation characteristics including impedance bandwidth, radiation patterns, and gain are simulated and measured. The proposed antenna has attractively good performances that the radiation patterns are unipolar. Method of applying bionics to antenna design will serve as a good candidate for the future antenna design. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1004–1006, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25891
An improvement for the acceleration technique based on monostatic bistatic equivalence for shooting and bouncing ray method
Authors: Ding Jianjun , Chen Ru‐shan , Zhou Huan , Fan Z. H. 
Published: March 2011

AbstractAn efficient algorithm is present for improving the acceleration technique of the monostatic radar cross section (RCS) prediction based on monostatic bistatic equivalence principle for the shooting and bouncing ray (SBR) method. Using the monostatic bistatic principle, the time consumed by the monostatic RCS simulation can be greatly reduced since the ray tracing procedure of the SBR method is avoided for a lot of incident angles. However, the result of the monostatic RCS using the monostatic bistatic equivalence get worse in the case of multiple bounces in ray tracing. To remedy this disadvantage, parts of rays are chosen with a sophisticated algorithm to be traced in order to correct the phase and location of the ray tubes. Numerical results demonstrate that the present algorithm is efficient for the SBR method in analysis of electrical large objects. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1178–1183, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25892