bluuebunny/crossref_metadata_2025_split huggingface dataset:
A comparative study of the functional morphology of parapodia and setae in nereids (Polychaeta: Nereididae)
Authors: Hesselberg  , Vincent  
Published: February 2006

AbstractErrant polychaetes of the family Nereididae can be found in a wide range of sub- and intertidal habitats. They can burrow, crawl and swim. The latter two behaviours are primarily achieved by the use of parapodia and their attached setae. Here we compare the parapodia and setae of five species of atoke nereids living in either soft or hard substrate in a scanning electron microscopy (SEM) study. Three types of setae, found in all the worms examined, were consistently different across species, allowing us to compare setal distribution. However, neither distribution nor number of setae, or intersetal gap showed a clear dependence on substrate. Thus it appears that the morphology is not adapted to a specific substrate. This might be because both the parapodia and the setae serve multiple functions in the living animal. Location of the parapodium and the size of the intersetal gap showed some dependence on whether the atoke stage swims. However, neither the area of the parapodium nor of the setal bundles seems to relate to swimming. Phylogenetic relationships amongst the examined species, from three genera all in the subfamily Nereidinae, did not significantly influence either of the morphological parameters investigated. This study indicates that the morphology of the parapodia and setae of nereids is not adapted to any specific function, instead they are presumably important for a variety of tasks performed by the worms.
Plotting the course of an African clawed frog invasion in Western France
Authors: Fouquet Antoine , Measey G. John 
Published: February 2006

AbstractThe African clawed frog, Xenopus laevis, is an invasive species with considerable impact in mediterranean climates, similar to its native South African Cape. A population has been established in western France since the early 1980s with a single, known, original release point. This study attempts to determine the limits of the invasion by trapping in 169 ponds in 2001 and 2002. Subsequent trapping of 192 ponds in 2003 and 2004 was undertaken in order to chart the progress of invasion, and to test the hypothesis that ponds were mostly colonised using rivers and streams as corridors. Of ponds without X. laevis in 2001/2002, 36% were found to have been colonised by 2003/2004. The findings clearly show that, while lotic corridors are used by this principally aquatic species, most ponds are colonised through overland migration. The consequences of this finding for invasions in France and other European countries are briefly discussed.
Influence of antibiotic on feed conversion efficiency of mulberry silkworm (Bombyx mori L.)
Authors: Rahmathulla  , Nayak Padmanav , Vindya  , Himantharaj  , Rajan  
Published: February 2006

Abstract
The influence of oral intake of an antibiotic (Norfloxacin®) through mulberry leaf at two concentrations (50 and 100 ppm) on the feed conversion efficiency parameters of silkworm hybrids, viz. bivoltine (CSR2 × CSR4) and crossbreed (BL67 × CSR106), was studied. Feed consumption data showed that the food consumption of antibiotic-treated batches was on par with the control. However, nutritional indices parameters such as digesta, approximate digestibility and reference ratio were significantly higher in the antibiotic-treated batches. Similarly, the nutritional efficiency parameters such as efficiency of ingested food into larvae, cocoon and shell were significantly higher in the antibiotic treated batches. The ingesta required to produce one gram of larva, cocoon and shell were significantly lower in treated batches. Most of the feed conversion efficiency parameters related to digesta, such as efficiency of digested food into larvae, cocoon and shell were not significantly different between the control and the treated batches. The results indicated that higher assimilation and conversion of food was observed in silkworm treated with antibiotic.
Spermatogenesis in two Iberian Podarcis lizards: relationships with male traits
Authors: Carretero Miguel , Ribeiro Raquel , Barbosa Diana , Sá-Sousa Paulo , Harris D. James 
Published: February 2006

Abstract
The spermatogenic cycles of Podarcis bocagei and P. carbonelli, two lacertids previously considered conspecific, were analysed in northwest Portugal. Monthly sampling was carried out at three sites: a zone of strict syntopy and two sites of allopatry for both species, all of them geographically close and harbouring similar habitats. The maritime Atlantic climate, which allows males to remain active most of the year, plays a determinant role on the variation of the mixed-type cycle, typical of lacertids in temperate regions. Comparison with other populations and species indicates that climate modifies the pattern of spermatogenesis by restricting the beginning (but not the end) of the activity period. Results also corroborate previous studies that report an agreement between the variations in the gonads observed at both microscopic and macroscopic scales in the reproductive period. Peaks for spermatozoa were delayed in sympatry but competition cannot be directly concluded. Furthermore, relationships between the number of spermatozoa and body size suggest sperm competition and possibly a reproductive interaction between the species.
3-PG Productivity Modeling of Regenerating Amazon Forests: Climate Sensitivity and Comparison with MODIS-Derived NPP
Authors: White Joseph D. , Scott Neal A. , Hirsch Adam I. , Running Steven W. 
Published: February 2006

Abstract
Potential forest growth predicted by the Physiological Principles in Predicting Growth (3-PG) model was compared for forest and deforested areas in the Legal Amazon to assess potential differing regeneration associated with climate. Historical deforestation and regeneration have occurred in environmentally marginal areas that influence regional carbon sequestration estimates. Effects of El Niño–induced drought further reduce simulated production by decreasing soil water availability in areas with shallow soils and high transpiration potential. The model was calibrated through comparison of literature biomass and with satellite-based estimates. Net primary productivity (NPP) for mature Amazonian forests from the 3-PG model was positively correlated (r 2 = 0.77) with a Moderate Resolution Imaging Spectroradiometer (MODIS)-derived algorithm, though with some bias. Annual total NPP for the study area using a 1961–90 average climatology was 4.6 Pg C yr−1, which decreased to 4.2 Pg C yr−1 when simulated with climate from the severe 1997/98 El Niño event. From a regional analysis, results showed that biomass accumulation is almost entirely controlled by the availability of soil water. Also, areas currently forested in the eastern Amazon are more sensitive to extreme El Niño–induced drought than southern areas with the greatest deforestation extent.
Forest Understory Fire in the Brazilian Amazon in ENSO and Non-ENSO Years: Area Burned and Committed Carbon Emissions
Authors: Alencar Ane , Nepstad Daniel , Diaz Mariadel Carmen Vera 
Published: February 2006

Abstract
Understory fires, which burn the floor of standing forests, are one of the most important types of forest impoverishment in the Amazon, especially during the severe droughts of El Niño–Southern Oscillation (ENSO) episodes. However, the authors are aware of no estimates of the areal extent of these fires for the Brazilian Amazon and, hence, of their contribution to Amazon carbon fluxes to the atmosphere. In this paper, the area of forest understory fires for the Brazilian Amazon region is calculated during an El Niño (1998) and a non–El Niño (1995) year based on forest fire scars mapped with satellite images for three locations in eastern and southern Amazonia, where deforestation is concentrated. The three study sites represented a gradient of both forest types and dry season severity. The burning scar maps were used to determine how the percentage of forest that burned varied with distance from agricultural clearings. These spatial functions were then applied to similar forest/climate combinations outside of the study sites to derive an initial estimate for the Brazilian Amazon. Ninety-one percent of the forest area that burned in the study sites was within the first kilometer of a clearing for the non-ENSO year and within the first four kilometers for the ENSO year. The area of forest burned by understory forest fire during the severe drought (ENSO) year (3.9 × 106 ha) was 13 times greater than the area burned during the average rainfall year (0.2 × 106 ha), and twice the area of annual deforestation. Dense forest was, proportionally, the forest type most affected by understory fires during the El Niño year, while understory fires were concentrated in transitional forests during the year of average rainfall. The estimate here of aboveground tree biomass killed by fire ranged from 0.049 to 0.329 Pg during the ENSO and from 0.003 to 0.021 Pg during the non-ENSO year.
Using prescribing health and population data to describe the health of a locality: the development and evaluation of a locality health profile
Authors: Steinke Douglas , Burney Susan , Bennie Marion , Hudson Steve 
Published: February 2006

Abstract

Objective
To develop and evaluate a pharmaco-epidemiological and public health profile that will aid in the determination and evaluation of the health and pharmaceutical needs of a local population with the National Health Service (NHS).

Method
Two local health areas (known as local health care co-operatives (LHCCs)) in NHS Lothian with diverse population characteristics had health profiles formally developed using prescribing, hospitalisation and other public health data. The integrated report was able to highlight morbidity issues in each LHCC that could be acted on by either LHCC management or local pharmacy groups. A steering committee and focus groups were used in the design and evaluation process. An evaluation survey of participants including LHCC management, community and LHCC pharmacists and other healthcare professionals was conducted with the main outcome measure being the relative utility of the health profile.

Key findings
Participants evaluating the health profiles found them informative and useful in decision making and planning for the locality. Participants anticipated using prescribing data to fill information gaps in other datasets and/or provide a primary care perspective to health in the locality.

Conclusions
Health profiles were developed from prescribing health and population data that were shown to be meaningful and useful to local health authority management and other healthcare professionals. The health profiles contained information that could be used to inform decisions or identify areas where further investigation may be required to find out why a particular anomaly is occurring. In Scotland, the focus of a new community pharmacy contract is on the dual elements of chronic disease management and public health contributions, through prevention of disease and/or limitation of disease impact. There is an urgent need to develop tools that help to inform professional interventions involving pharmacists, and thereby improvements to multidisciplinary co-operation. This study suggests a means of describing the population characteristics for informing a network of community pharmacists about public health priorities within their LHCC.
N-tert-Butyl-N-chlorocyanamide: A Mild and Efficient Chlorinating Agent for the Synthesis of Dialkyl/Diaryl Chlorophosphates
Authors: Kumar Vinod , Kaushik Mahabir Parshad 
Published: February 2006

Abstract
An efficient reagent for the synthesis of dialkyl/diaryl chlorophosphates has been developed. N-tert-Butyl-N-chlorocyanamide acts as a chlorinating agent both in polar as well in non-polar medium and the transformation of dialkyl/diaryl phosphites to the dialkyl/diaryl chlorophosphates takes place rapidly under mild conditions in quantitative yields.
Novel Aggregation of Bis(thiolato)-type Cobalt(III) Octahedra Assisted by Silver(I) Ions: Structural Interconversion by Counter Anions
Authors: Konno Takumi , Aridomi Takashi , Hattori Masashi , Hirotsu Masakazu 
Published: February 2006

Abstract
The reaction of [Ni{Co(aet)2(en)}2]4+ (aet = 2-aminoethanethiolate) with AgI in the presence of ClO4− and NO3− anions gave a S-bridged CoIII4AgI4 octanuclear and a (CoIII2AgI3)n polymeric complexes, respectively, which are interconvertible with each other by changing the counter anions.
Stability of Large Segmental Duplications in the Yeast Genome
Authors: Koszul Romain , Dujon Bernard , Fischer Gilles 
Published: February 2006

Abstract
The high level of gene redundancy that characterizes eukaryotic genomes results in part from segmental duplications. Spontaneous duplications of large chromosomal segments have been experimentally demonstrated in yeast. However, the dynamics of inheritance of such structures and their eventual fixation in populations remain largely unsolved. We analyzed the stability of a vast panel of large segmental duplications in Saccharomyces cerevisiae (from 41 kb for the smallest to 268 kb for the largest). We monitored the stability of three different types of interchromosomal duplications as well as that of three intrachromosomal direct tandem duplications. In the absence of any selective advantage associated with the presence of the duplication, we show that a duplicated segment internally translocated within a natural chromosome is stably inherited both mitotically and meiotically. By contrast, large duplications carried by a supernumerary chromosome are highly unstable. Duplications translocated into subtelomeric regions are lost at variable rates depending on the location of the insertion sites. Direct tandem duplications are lost by unequal crossing over, both mitotically and meiotically, at a frequency proportional to their sizes. These results show that most of the duplicated structures present an intrinsic level of instability. However, translocation within another chromosome significantly stabilizes a duplicated segment, increasing its chance to get fixed in a population even in the absence of any immediate selective advantage conferred by the duplicated genes.
Population Genetics of Translational Robustness
Authors: Wilke Claus O , Drummond D Allan 
Published: February 2006

Abstract
Recent work has shown that expression level is the main predictor of a gene's evolutionary rate and that more highly expressed genes evolve slower. A possible explanation for this observation is selection for proteins that fold properly despite mistranslation, in short selection for translational robustness. Translational robustness leads to the somewhat paradoxical prediction that highly expressed genes are extremely tolerant to missense substitutions but nevertheless evolve very slowly. Here, we study a simple theoretical model of translational robustness that allows us to gain analytic insight into how this paradoxical behavior arises.
Trans-specificity at Loci Near the Self-Incompatibility Loci in Arabidopsis
Authors: Charlesworth Deborah , Kamau Esther , Hagenblad Jenny , Tang Chunlao 
Published: February 2006

Abstract
We compared allele sequences of two loci near the Arabidopsis lyrata self-incompatibility (S) loci with sequences of A. thaliana orthologs and found high numbers of shared polymorphisms, even excluding singletons and sites likely to be highly mutable. This suggests maintenance of entire S-haplotypes for long evolutionary times and extreme recombination suppression in the region.
Genotype-by-Environment Interactions Influencing the Emergence of rpoS Mutations in Escherichia coli Populations
Authors: King Thea , Seeto Shona , Ferenci Thomas 
Published: February 2006

Abstract
Polymorphisms in rpoS are common in Escherichia coli. rpoS status influences a trade-off between nutrition and stress resistance and hence fitness across different environments. To analyze the selective pressures acting on rpoS, measurement of glucose transport rates in rpoS+ and rpoS bacteria was used to estimate the role of Fnc, the fitness gain due to improved nutrient uptake, in the emergence of rpoS mutations in nutrient-limited chemostat cultures. Chemostats with set atmospheres, temperatures, pH's, antibiotics, and levels of osmotic stress were followed. Fnc was reduced under anaerobiosis, high osmolarity, and with chloramphenicol, consistent with a reduced rate of rpoS enrichment in these conditions. Fnc remained high, however, with alkaline pH and low temperature but rpoS sweeps were diminished. Under these conditions, Fsp, the fitness reduction due to lowered stress protection, became significant. We also estimated whether the fitness need for the gene was related to its regulation. No consistent pattern emerged between the level of RpoS and the loss of rpoS function in particular environments. This dissection allows an unprecedented view of the genotype-by-environment interactions controlling a mutational sweep and shows that both Fnc and Fsp are influenced by individual stresses and that additional factors contribute to selection pressure in some environments.
Evolution of Class III Homeodomain–Leucine Zipper Genes in Streptophytes
Authors: Floyd Sandra K , Zalewski Christopher S , Bowman John L 
Published: February 2006

Abstract
Land plants underwent tremendous evolutionary change following the divergence of the ancestral lineage from algal relatives. Several important developmental innovations appeared as the embryophyte clade diversified, leading to the appearance of new organs and tissue types. To understand how these changes came about, we need to identify the fundamental genetic developmental programs that are responsible for growth, patterning, and differentiation and describe how these programs were modified and elaborated through time to produce novel morphologies. Class III homeodomain–leucine zipper (class III HD–Zip) genes, identified in the model plant Arabidopsis thaliana, provide good candidates for basic land plant patterning genes. We show that these genes may have evolved in a common ancestor of land plants and their algal sister group and that the gene family has diversified as land plant lineages have diversified. Phylogenetic analysis, expression data from nonflowering lineages, and evidence from Arabidopsis and other flowering plants indicate that class III HD–Zip genes acquired new functions in sporophyte apical growth, vascular patterning and differentiation, and leaf development. Modification of expression patterns that accompanied diversification of class III HD–Zip genes likely played an important role in the evolution of land plant form.
The Cotranscribed Salmonella enterica sv. Typhi tsx and impX Genes Encode Opposing Nucleoside-Specific Import and Export Proteins
Authors: Bucarey Sergio A , Villagra Nicolas A , Fuentes Juan A , Mora Guido C 
Published: February 2006

Abstract
The Salmonella enterica tsx gene encodes a nucleoside-specific outer membrane channel. The Tsx porin is essential for the prototrophic growth of S. enterica sv. Typhi in the absence of nucleosides. RT–PCR analysis shows that the tsx gene is cotranscribed with an open reading frame unique to S. enterica, impX (STY0450), which encodes an inner membrane protein 108 amino acids in length, which is predicted to have only two transmembrane α-helices. Fusions of the lacZ gene to both tsx and impX reveal that the transcription of both genes is induced in the presence of adenosine. A null mutation in the S. Typhi impX gene suppresses the induced auxotrophy for adenosine or thymidine resulting from a tsx mutation and confers sensitivity to high concentrations of adenosine or thymidine. The ImpX protein, when tagged with a 3xFLAG epitope, is functional and associates with the inner membrane; impX mutants are defective in the export of 3H-radiolabeled thymidine. Taken together, these and other results suggest that the S. Typhi Tsx porin and ImpX inner membrane protein facilitate competing mechanisms of thymidine influx and efflux, respectively, to maintain the steady-state levels of internal nucleoside pools.
Distribution of Microsatellites in the Genome ofMedicago truncatula: A Resource of Genetic Markers That Integrate Genetic and Physical Maps
Authors: Mun Jeong-Hwan , Kim Dong-Jin , Choi Hong-Kyu , Gish John , Debellé Frédéric , Mudge Joanne , Denny Roxanne , Endré Gabriella , Saurat Oliver , Dudez Anne-Marie , Kiss Gyorgy B , Roe Bruce , Young Nevin D , Cook Douglas R 
Published: February 2006

AbstractMicrosatellites are tandemly repeated short DNA sequences that are favored as molecular-genetic markers due to their high polymorphism index. Plant genomes characterized to date exhibit taxon-specific differences in frequency, genomic location, and motif structure of microsatellites, indicating that extant microsatellites originated recently and turn over quickly. With the goal of using microsatellite markers to integrate the physical and genetic maps of Medicago truncatula, we surveyed the frequency and distribution of perfect microsatellites in 77 Mbp of gene-rich BAC sequences, 27 Mbp of nonredundant transcript sequences, 20 Mbp of random whole genome shotgun sequences, and 49 Mbp of BAC-end sequences. Microsatellites are predominantly located in gene-rich regions of the genome, with a density of one long (i.e., ≥20 nt) microsatellite every 12 kbp, while the frequency of individual motifs varied according to the genome fraction under analysis. A total of 1,236 microsatellites were analyzed for polymorphism between parents of our reference intraspecific mapping population, revealing that motifs (AT)n, (AG)n, (AC)n, and (AAT)n exhibit the highest allelic diversity. A total of 378 genetic markers could be integrated with sequenced BAC clones, anchoring 274 physical contigs that represent 174 Mbp of the genome and composing an estimated 70% of the euchromatic gene space.
Euchromatin and Pericentromeric Heterochromatin: Comparative Composition in the Tomato Genome
Authors: Wang Ying , Tang Xiaomin , Cheng Zhukuan , Mueller Lukas , Giovannoni Jim , Tanksley Steve D 
Published: February 2006

Abstract
Eleven sequenced BACs were annotated and localized via FISH to tomato pachytene chromosomes providing the first global insights into the compositional differences of euchromatin and pericentromeric heterochromatin in this model dicot species. The results indicate that tomato euchromatin has a gene density (6.7 kb/gene) similar to that of Arabidopsis and rice. Thus, while the euchromatin comprises only 25% of the tomato nuclear DNA, it is sufficient to account for ∼90% of the estimated 38,000 nontransposon genes that compose the tomato genome. Moreover, euchromatic BACs were largely devoid of transposons or other repetitive elements. In contrast, BACs assigned to the pericentromeric heterochromatin had a gene density 10–100 times lower than that of the euchromatin and are heavily populated by retrotransposons preferential to the heterochromatin—the most abundant transposons belonging to the Jinling Ty3/gypsy-like retrotransposon family. Jinling elements are highly methylated and rarely transcribed. Nonetheless, they have spread throughout the pericentromeric heterochromatin in tomato and wild tomato species fairly recently—well after tomato diverged from potato and other related solanaceous species. The implications of these findings on evolution and on sequencing the genomes of tomato and other solanaceous species are discussed.