bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solid phase sorption of microamount of Hg(II) onto 1-(2-thiazolylazo)-2-naphthol (TAN) loaded polyurethane foam
Authors: Saeed Muhammad M. , Bajwa Sadia Z. , Ansari Muhammad S. , Ahmed Riaz 
Published: April 2005

Summary
Mercury is a toxic environmental pollutant. A method has been developed to remove these metal ions by preconcentrating onto 1-(2-thiazolylazo)-2-naphthol (TAN) loaded polyurethane (PUR) foam that proves an excellent sorbent for these metal ions. The accumulation conditions are optimized with respect to pH, shaking time, loading capacity and adsorbent weight. The optimum pH for sorption was found to be 7, which is close to the natural water. Optimum shaking time for Hg(II) is 30 min. The kinetic studies indicate that sorption occurs through intraparticle diffusion process. Classical adsorption isotherms are applied to determine the nature of sorption. The sorption free energy value indicates that adsorption process is chemisorption. Effect of temperature has been used to compute the values of ΔH, ΔS and ΔG for Hg(II). These are 19.0±0.9 kJ mol−1, 80.73±0.1 J K−1 mol−1, −5.1±0.9 kJ mol−1 respectively. Adsorption of metal ions is endothermic, spontaneous and entropy driven. Effect of different anions and cations are observed. Adsorption via Hg(II)-TAN complex formation on PUR foam was supported by spectrophotometric studies.
Single-crystal-to-single-crystal [2 + 2] photodimerizations: from discovery to design
Authors: Friščić Tomislav , MacGillivray Leonard R. 
Published: April 2005

AbstractThe purpose of this review is to address fundamentals and applications of single-crystal-to-single-crystal (SCSC) reactions, based on the [2 + 2] photodimerization. An overview of SCSC [2 + 2] photodimerizations, which comprise single- and multi-component solids, will be given. We reveal that materials that exhibit SCSC reactivity can be considered to have been achievedviaeither discovery or design. We suggest that SCSC [2 + 2] photodimerizations, if generally achieved, could provide new avenues to control bulk physical properties of solid-state materials.
Supramolecular inorganic frameworks: “dynamic” challenges for structural chemistry
Authors: May Leslie J. , Shimizu George K. H. 
Published: April 2005

Abstract
The supramolecular chemistry of discrete assemblies of various topologies (cages, grids, helices, etc.) has been extensively studied. With regards to the supramolecular chemistry of infinite solids, attention is usually focussed on the design of an efficient, programmed assembly motif through the choice of suitable building blocks. However, as well illustrated by the discrete structures, a hallmark property of a supramolecular system is its ability to reversibly assemble to optimize its structure, effectively error checking. For a rigid infinite framework, this feature is less obvious. Error checking is manifested in an extended framework through structural rearrangements in the solid state. Coordination frameworks, as they are often at least partially sustained by weaker interactions, can demonstrate such dynamic behavior in response to some external stimulus. Selected examples, chosen to illustrate a range of network types and rearrangements, will be discussed in this short review.
A High-Frequency Null Mutant of an Odorant-Binding Protein Gene, Obp57e, in Drosophila melanogaster
Authors: Takahashi Aya , Takano-Shimizu Toshiyuki 
Published: April 2005

Abstract
We have found a null mutant of an odorant-binding protein, Obp57e, in Drosophila melanogaster. This frameshift mutation, which is a 10-bp deletion in the coding region, is at a high frequency in the Kyoto population and is also present in Taiwan and Africa. We have sequenced a 1.5-kb region including the tandemly duplicated gene, Obp57d, from 16 inbred lines sampled in Kyoto, Japan. The analyses showed a peak of nucleotide diversity and strong linkage disequilibrium around this mutation. This pattern suggests an elevated mutation rate or an influence of balancing selection in this region. The level of nucleotide divergence between D. melanogaster and D. simulans does not support the former possibility. Thus, this presence/absence polymorphism may be due to balancing selection, which takes advantage of the relatively weak functional constraint in members of a large gene family. In addition, the Obp57d gene region showed an excess of high-frequency-derived mutants that is consistent with a pattern predicted under positive natural selection.
A Mitogen-Activated Protein Kinase Pathway Essential for Mating and Contributing to Vegetative Growth in Neurospora crassa
Authors: Li Dan , Bobrowicz Piotr , Wilkinson Heather H , Ebbole Daniel J 
Published: April 2005

Abstract
MAP kinases homologous to Saccharomyces cerevisiae Fus3p/Kss1p have been identified in plant pathogenic fungi and are required for pathogenicity and sexual reproduction. To better understand the role of MAP kinase signaling in Neurospora crassa, and to identify downstream target genes of the pathway, we isolated, cloned, and disrupted the FUS3 homolog mak-2. Ste12p is a transcription factor target of Fus3p that activates genes of the mating pathway in yeast, and we also characterized the N. crassa STE12 homolog pp-1. The mak-2 and pp-1 mutants have reduced growth rate, produce short aerial hyphae, and fail to develop protoperithecia. In addition, ascospores carrying null mutations of either gene are inviable. Subtractive cloning was used to isolate genes having reduced expression in the mak-2 mutant. Expression of some of these genes is protoperithecia specific and three of them are part of a gene cluster potentially involved in the production of a polyketide secondary metabolite. Microarray analysis was used to extend the analysis of gene expression in mak-2 and pp-1 mutants. The role of the MAP kinase pathway in both sexual and asexual development as well as secondary metabolism is consistent with the dual regulation of the mating process and pathogencity observed in fungal pathogens.
The Program of Sex Chromosome Pairing in Meiosis Is Highly Conserved Across Marsupial Species
Authors: Page Jesús , Berríos Soledad , Parra María Teresa , Viera Alberto , Suja José Ángel , Prieto Ignacio , Barbero José Luis , Rufas Julio S , Fernández-Donoso Raúl 
Published: April 2005

Abstract
Marsupials present a series of genetic and chromosomal features that are highly conserved in very distant species. One of these features is the absence of a homologous region between X and Y chromosomes. According to this genetic differentiation, sex chromosomes do not synapse during the first meiotic prophase in males, and a special structure, the dense plate, maintains sex chromosome association. In this report we present results on the process of meiotic sex chromosome pairing obtained from three different species, Thylamys elegans, Dromiciops gliroides, and Rhyncholestes raphanurus, representing the three orders of American marsupials. We have investigated the relationships between the axial structures organized along sex chromosomes and the formation of the dense plate. We found that in the three species the dense plate arises as a modification of sex chromosomal axial elements, but without the involvement of other meiotic axial structures, such as the cohesin axes. Considering the phylogenetic relationships among the marsupials studied here, our data reinforce the idea that the dense plate emerged early in marsupial evolution as an efficient mechanism to ensure the association of the nonhomologous sex chromosomes. This situation could have influenced the further evolution of sex chromosomes in marsupials.
Chromosome Sorting in Tetraploid Wheat and Its Potential for Genome Analysis
Authors: Kubaláková Marie , Kovářová Pavlína , Suchánková Pavla , Číhalíková Jarmila , Bartoš Jan , Lucretti Sergio , Watanabe Nobuyoshi , Kianian Shahryar F , Doležel Jaroslav 
Published: April 2005

Abstract
This study evaluates the potential of flow cytometry for chromosome sorting in durum wheat (Triticum turgidum Desf. var. durum, 2n = 4x = 28). Histograms of fluorescence intensity (flow karyotypes) obtained after the analysis of DAPI-stained chromosomes consisted of three peaks. Of these, one represented chromosome 3B, a small peak corresponded to chromosomes 1A and 6A, and a large peak represented the remaining 11 chromosomes. Chromosomes sorted onto microscope slides were identified after fluorescence in situ hybridization (FISH) with probes for GAA microsatellite, pSc119.2, and Afa repeats. Genomic distribution of these sequences was determined for the first time in durum wheat and a molecular karyotype has been developed for this crop. Flow karyotyping in double-ditelosomic lines of durum wheat revealed that the lines facilitated sorting of any arm of the wheat A- and B-genome chromosomes. Compared to hexaploid wheat, flow karyotype of durum wheat is less complex. This property results in better discrimination of telosomes and high purities in sorted fractions, ranging from 90 to 98%. We have demonstrated that large insert libraries can be created from DNA purified using flow cytometry. This study considerably expands the potential of flow cytogenetics for use in wheat genomics and opens the possibility of sequencing the genome of this important crop one chromosome arm at a time.
The Phosphatase Subunit Tap42 Functions Independently of Target of Rapamycin to Regulate Cell Division and Survival in Drosophila
Authors: Cygnar Katherine D , Gao Xinsheng , Pan Duojia , Neufeld Thomas P 
Published: April 2005

Abstract
The protein phosphatase 2A (PP2A) regulatory subunit Tap42 is essential for target of rapamycin (TOR)-mediated signaling in yeast, but its role in higher eukaryotes has not been established. Here we show that Tap42 does not contribute significantly to TOR signaling in Drosophila, as disruption of the Tap42 gene does not cause defects in cell growth, metabolism, or S6-kinase activity characteristic of TOR inactivation. In addition, Tap42 is not required for increased cell growth in response to activation of TOR signaling. Instead, we find that Tap42 mutations cause disorganization of spindle microtubules in larval neuroblasts, leading to a preanaphase mitotic arrest in these cells. Loss of Tap42 ultimately results in increased JNK signaling, caspase activation, and cell death. These phenotypes are associated with increased accumulation and nuclear localization of PP2A in Tap42 mutant cells. Our results demonstrate that the role of Tap42 in TOR signaling has not been conserved in higher eukaryotes, indicating fundamental differences in the mechanisms of TOR signaling between yeast and higher eukaryotes.
Theoretical Basis for the Identification of Allelic Variants That Encode Drug Efficacy and Toxicity
Authors: Lin Min , Wu Rongling 
Published: April 2005

AbstractAlmost all drugs that produce a favorable response (efficacy) may also produce adverse effects (toxicity). The relative strengths of drug efficacy and toxicity that vary in human populations are controlled by the combined influences of multiple genes and environmental influences. Genetic mapping has proven to be a powerful tool for detecting and identifying specific DNA sequence variants on the basis of the haplotype map (HapMap) constructed from single-nucleotide polymorphisms (SNPs). In this article, we present a novel statistical model for sequence mapping of two different but related drug responses. This model is incorporated by mathematical functions of drug response to varying doses or concentrations and the statistical device used to model the correlated structure of the residual (co)variance matrix. We implement a closed-form solution for the EM algorithm to estimate the population genetic parameters of SNPs and the simplex algorithm to estimate the curve parameters describing the pharmacodynamic changes of different genetic variants and matrix-structuring parameters. Extensive simulations are performed to investigate the statistical properties of our model. The implications of our model in pharmacogenetic and pharmacogenomic research are discussed.
DNA Variation at the Invertase Locus invGE/GF Is Associated With Tuber Quality Traits in Populations of Potato Breeding Clones
Authors: Li Li , Strahwald Josef , Hofferbert Hans-Reinhard , Lübeck Jens , Tacke Eckart , Junghans Holger , Wunder Jörg , Gebhardt Christiane 
Published: April 2005

Abstract
Starch and sugar content of potato tubers are quantitative traits, which are models for the candidate gene approach for identifying the molecular basis of quantitative trait loci (QTL) in noninbred plants. Starch and sugar content are also important for the quality of processed products such as potato chips and French fries. A high content of the reducing sugars glucose and fructose results in inferior chip quality. Tuber starch content affects nutritional quality. Functional and genetic models suggest that genes encoding invertases control, among other things, tuber sugar content. The invGE/GF locus on potato chromosome IX consists of duplicated invertase genes invGE and invGF and colocalizes with cold-sweetening QTL Sug9. DNA variation at invGE/GF was analyzed in 188 tetraploid potato cultivars, which have been assessed for chip quality and tuber starch content. Two closely correlated invertase alleles, invGE-f and invGF-d, were associated with better chip quality in three breeding populations. Allele invGF-b was associated with lower tuber starch content. The potato invertase gene invGE is orthologous to the tomato invertase gene Lin5, which is causal for the fruit-sugar-yield QTL Brix9-2-5, suggesting that natural variation of sugar yield in tomato fruits and sugar content of potato tubers is controlled by functional variants of orthologous invertase genes.
The Bombyx mori Karyotype and the Assignment of Linkage Groups
Authors: Yoshido Atsuo , Bando Hisanori , Yasukochi Yuji , Sahara Ken 
Published: April 2005

AbstractLepidopteran species have a relatively high number of small holocentric chromosomes (Bombyx mori, 2n = 56). Chromosome identification has long been hampered in this group by the high number and by the absence of suitable markers like centromere position and chromosome bands. In this study, we carried out fluorescence in situ hybridization (FISH) on meiotic chromosome complements using genetically mapped B. mori bacterial artificial chromosomes (BACs) as probes. The combination of two to four either green or red fluorescence-labeled probes per chromosome allowed us to recognize unequivocally each of the 28 bivalents of the B. mori karyotype by its labeling pattern. Each chromosome was assigned one of the already established genetic linkage groups and the correct orientation in the chromosome was defined. This facilitates physical mapping of any other sequence and bears relevance for the ongoing B. mori genome projects. Two-color BAC-FISH karyotyping overcomes the problem of chromosome recognition in organisms where conventional banding techniques are not available.
The C-Terminal Half of Saccharomyces cerevisiae Mad1p Mediates Spindle Checkpoint Function, Chromosome Transmission Fidelity and CEN Association
Authors: Kastenmayer James P , Lee Marina S , Hong Andrew L , Spencer Forrest A , Basrai Munira A 
Published: April 2005

Abstract
The evolutionarily conserved spindle checkpoint is a key mechanism ensuring high-fidelity chromosome transmission. The checkpoint monitors attachment between kinetochores and mitotic spindles and the tension between sister kinetochores. In the absence of proper attachment or tension, the spindle checkpoint mediates cell cycle arrest prior to anaphase. Saccharomyces cerevisiae Mad1p is required for the spindle checkpoint and for chromosome transmission fidelity. Moreover, Mad1p associates with the nuclear pore complex (NPC) and is enriched at kinetochores upon checkpoint activation. Using partial mad1 deletion alleles we determined that the C-terminal half of Mad1p is necessary and sufficient for checkpoint activation in response to microtubule depolymerizing agents, high-fidelity transmission of a reporter chromosome fragment, and in vivo association with centromeres, but not for robust NPC association. Thus, spindle checkpoint activation and chromosome transmission fidelity correlate and these Mad1p functions likely involve kinetochore association but not robust NPC association. These studies are the basis for elucidating the role of protein complexes containing Mad1p in the spindle checkpoint pathway and in maintaining genome stability in S. cerevisiae and other systems.
Origins of Host-Specific Populations of the Blast Pathogen Magnaporthe oryzae in Crop Domestication With Subsequent Expansion of Pandemic Clones on Rice and Weeds of Rice
Authors: Couch Brett C , Fudal Isabelle , Lebrun Marc-Henri , Tharreau Didier , Valent Barbara , van Kim Pham , Nottéghem Jean-Loup , Kohn Linda M 
Published: April 2005

Abstract
Rice, as a widely and intensively cultivated crop, should be a target for parasite host shifts and a source for shifts to co-occurring weeds. Magnaporthe oryzae, of the M. grisea species complex, is the most important fungal pathogen of rice, with a high degree of host specificity. On the basis of 10 loci from six of its seven linkage groups, 37 multilocus haplotypes among 497 isolates of M. oryzae from rice and other grasses were identified. Phylogenetic relationships among isolates from rice (Oryza sativa), millet (Setaria spp.), cutgrass (Leersia hexandra), and torpedo grass (Panicum repens) were predominantly tree like, consistent with a lack of recombination, but from other hosts were reticulate, consistent with recombination. The single origin of rice-infecting M. oryzae followed a host shift from a Setaria millet and was closely followed by additional shifts to weeds of rice, cutgrass, and torpedo grass. Two independent estimators of divergence time indicate that these host shifts predate the Green Revolution and could be associated with rice domestication. The rice-infecting lineage is characterized by high copy number of the transposable element MGR586 (Pot3) and, except in two haplotypes, by a loss of AVR-Co39. Both mating types have been retained in ancestral, well-distributed rice-infecting haplotypes 10 (mainly temperate) and 14 (mainly tropical), but only one mating type was recovered from several derived, geographically restricted haplotypes. There is evidence of a common origin of both ACE1 virulence genotypes in haplotype 14. Host-haplotype association is evidenced by low pathogenicity on hosts associated with other haplotypes.
Evaluation of Noise-Induced Hearing Loss in Young People Using a Web-Based Survey Technique
Authors: Chung Jeannie H. , Des Roches Catherine M. , Meunier John , Eavey Roland D. 
Published: April 2005

Objective. Many adolescents and young adults consciously expose themselves to loud music for entertainment. We hypothesized that these individuals might not be aware that exposure to loud music could result in hearing loss. Furthermore, we wished to assess the feasibility of a web-based survey to collect health information from this group.Methods. A 28-question survey was designed to target adolescents and young adults. The survey contained questions about views toward general health issues, including hearing loss, and was presented to random visitors at the MTV web site.Results. In 3 days, 9693 web surveys were completed. Hearing loss was defined on a Likert scale as “a very big problem” by 8% of respondents compared with other health issues: sexually transmitted diseases, 50%; alcohol/drug use, 47%; depression, 44%; smoking, 45%; nutrition and weight issues, 31%; and acne, 18%. Notably, most respondents had experienced tinnitus or hearing impairment attending concerts (61%) and clubs (43%). Only 14% of respondents had used earplugs; however, many could be motivated to try ear protection if they were aware of the potential for permanent hearing loss (66%) or were advised by a medical professional (59%).Conclusions. A majority of young adults have experienced tinnitus and hearing impairment after exposure to loud music. Fortunately, many of these individuals could be motivated to wear ear protection. This novel web-based survey technique rapidly generated a large database and is a feasible method to obtain health data from this group.
Early Detection of Imperforate Hymen Prevents Morbidity From Delays in Diagnosis
Authors: Posner Jill C. , Spandorfer Philip R. 
Published: April 2005

Objective. Although it is detectable at all ages through inspection of the external genitalia, imperforate hymen (IH) is a diagnosis that is missed commonly. We hypothesized that children with late diagnoses (predefined as ≥8 years of age, chosen to reflect the timing of normal menarche) would be more likely to be symptomatic, undergo more diagnostic testing, and lack appropriate documentation in their medical records, compared with children with earlier diagnoses (ie, &lt;8 years of age).Methods. All patients with IH were identified through searches of 3 hospital databases with International Classification of Diseases, Ninth Revision, codes. The medical records of eligible subjects were reviewed by a single, blinded researcher. Comparisons were made between children diagnosed at younger versus older ages.Results. A bimodal distribution of age at diagnosis was demonstrated; 43% (n = 10) of girls were diagnosed at &lt;8 years of age, and 57% (n = 13) were diagnosed at ≥8 years of age. Among older girls, 100% were symptomatic (abdominal pain and/or urinary symptoms; duration of symptoms: 1–120 days), whereas 90% of cases in the younger group were detected incidentally. Documentation was lacking for breast development (77%), pubic hair development (69%), and menstrual history (46%) among the older girls. Older children were more likely to present symptomatically (odds ratio: 42.0; 95% confidence interval: 3.1–1965.7) and to undergo ancillary testing (odds ratio: 20.3; 95% confidence interval: 1.6–983.1).Conclusions. Two distinct populations of girls with IH exist, ie, those diagnosed without symptoms at a young age and those not diagnosed until &gt;8 years of age. By incorporating an examination of the external genitalia into their routine practice, clinicians caring for children can prevent the significant delays in diagnosis, misdiagnosis, and morbidity associated with the latter group.