bluuebunny/crossref_metadata_2025 huggingface dataset:
Body size, diet and endoparasites of the microhylid frog Chiasmocleis capixaba in an Atlantic Forest area of southern Bahia state, Brazil
Authors: Van Sluys M. , Schittini G. M. , Marra R. V. , Azevedo A. R. M. , Vicente J. J. , Vrcibradic D.
Published: May 2006

We analyzed the diet composition, endoparasites and sexual size dimorphism of the microhylid frog Chiasmocleis capixaba (Microhylidae) from a "mussununga" habitat in the municipality of Nova Viçosa, southern Bahia state, Brazil. All the 119 specimens analyzed were collected in a single night of heavy rainfall. Females (mean snout-vent length = 15.7 + 3.0 mm) were significantly larger than males (mean snout-vent length = 13.2 + 2.1 mm), and specimens of both sexes were smaller than those of a conspecific population previously reported in Aracruz, state of Espírito Santo state. The diet of C. capixaba was dominated by mites, ants and collembolans. Seventy-nine frogs (66.4% of the total) were infected by helminths, all belonging to a single species, Cosmocerca ornata, an intestinal nematode parasite.
Trombose venosa profunda de membros superiores: estudo coorte retrospectivo de 52 casos
Authors: Yoshida Ricardo de Alvarenga , Sobreira Marcone Lima , Giannini Mariangela , Moura Regina , Rollo Hamilton Almeida , Yoshida Winston Bonetti , Maffei Francisco Humberto de Abreu
Published: May 2006

OBJETIVO: Rever os fatores predisponentes e a evolução em série de casos de trombose venosa profunda dos membros superiores de nossa instituição. MÉTODOS: Cinqüenta e dois pacientes consecutivos, com trombose venosa profunda dos membros superiores (29 homens e 23 mulheres), idade média de 52,3 anos, documentados por mapeamento dúplex (71,1%), flebografia (11,1%) ou clinicamente (15,6%), foram incluídos no presente estudo. RESULTADOS: As manifestações clínicas foram: dor no antebraço (24 casos - 46,1%), dor no braço (27 casos - 51,9%), edema do membro superior (45 casos - 86,5%), dor à compressão do membro superior (36 casos - 70,2%) e dor à movimentação do mesmo (32 casos - 61,7%). Os principais fatores de risco foram: punção ou acesso venoso (20 casos - 39,1%) e câncer (16 casos - 32,6%). As veias envolvidas foram: umeral (n = 18), axilar (n = 27), subclávia (n = 15) e jugular (n = 11). A embolia pulmonar estava inicialmente presente em quatro casos (7,6%). O tratamento inicial foi feito com heparina não-fracionada intravenosa (64,3%), subcutânea (16,7%), ou heparina de baixo peso molecular (17,1%), seguido de varfarina. Doze pacientes morreram antes da alta, em função de causas não relacionadas à embolia pulmonar. Foram acompanhados os 40 pacientes restantes por período de 3 meses a 10 anos, sendo que dois morreram de causas não relacionadas à embolia pulmonar, um paciente desenvolveu seqüelas pós-trombóticas, como edema residual e limitações aos movimentos, e seis ficaram com discretos sintomas residuais (edema e dor). CONCLUSÕES: A trombose venosa profunda dos membros superiores foi mais freqüente em pacientes submetidos a acessos venosos e com neoplasia em atividade. Comparando com dados da literatura, a evolução dos pacientes sob tratamento exclusivo com anticoagulantes foi, no mínimo, similar a outros tratamentos propostos.
Bone marrow stem cells and their role in angiogenesis
Authors: Reis Paulo Eduardo Ocke
Published: May 2006

The degree of symptomatology of a patient with peripheral arterial disease dictates the kind of treatment. Despite the known therapies, some patients continue to have pain with ambulation, which affects their quality of life. The therapeutic implications of the angiogenic growth factors were identified by the pioneering studies of Folkman et al. 2 decades ago. Further investigations established the possibility of the use of formulations of recombinant angiogenic growth factors, with the objective of developing or increasing the network of collaterals in animal models of chronic myocardial or limb ischemia. Researches suggest that primitive stem cells with whole bone marrow possess greater functional plasticity, capable of contributing to regeneration of ischemic limb muscle and vascular endothelium by adult stem cells. Local autologous marrow stromal cells implantation induces a neovascular response resulting in a significant increase in blood flow to the ischemic limb. In this article we review the studies that have established how the implantation of bone marrow cells into ischemic limbs increases collateral vessel formation.
The Relationship of Transforming Growth Factor‐β1 Gene Polymorphism, Its Plasma Level, and Gingival Overgrowth in Renal Transplant Recipients Receiving Different Immunosuppressive Regimens
Authors: Radwan‐Oczko Małgorzata , Boratyńska Maria , Ziętek Marek , Zołędziewska Magdalena , Jonkisz Anna
Published: May 2006

Background: Cyclosporin A (CsA) induces gingival overgrowth (GO) in patients who seem to be prone to this disorder. It is still impossible to determine which patients will develop GO. Patients treated with the new immunosuppressive drug tacrolimus seem not to have GO. The aims of this study were to investigate transforming growth factor‐β1 (TGF‐β1) gene polymorphisms in renal transplant recipients treated with CsA or tacrolimus and to establish an association between these polymorphisms and TGF‐β1 plasma concentration and the incidence of GO.

Methods: The examined group consisted of 134 renal transplant recipients. Ninety‐two underwent CsA treatment (50 with and 42 without GO), and 42 underwent tacrolimus treatment. Age, gender, time after transplantation, calcineurin inhibitor total dosage, number of teeth, and sulcus bleeding index were analyzed. TGF‐β1 plasma levels were estimated in 60 CsA‐ and 30 tacrolimus‐treated patients. Two biallelic polymorphisms of the TGF‐β1 gene were studied at codon 10 (at position +869) and at codon 25 (at position +915) in patients from the examined group and in 108 healthy volunteers (the control group).

Results: The distribution of the high, intermediate, and low TGF‐β1 producer phenotypes was comparable in all the studied groups and in the healthy controls. The high producer phenotype was more frequent in patients with GO. TGF‐β1 levels in the CsA group showed correlation with the phenotypes. The lowest incidence of GO was observed in the 10C/C genotype, whereas the highest was observed in the 10T/C genotype.

Conclusion: High and intermediate TGF‐β1 producer phenotypes and heterozygous genotype 10T/C might be considered risk factors for GO in patients treated with CsA.
Features, Applications, and Limitations of the Hybrid‐Maize Simulation Model
Authors: Yang Haishun , Dobermann Achim , Cassman Kenneth G. , Walters Daniel T.
Published: May 2006

The objective of this paper is to provide an overview of the Hybrid‐Maize software (www.hybridmaize.unl.edu, verified 28 Feb. 2006), with emphasis on its practical applications based on our own experience and feedback from users. The Hybrid‐Maize model is a computer program that simulates the growth and yield of a corn crop (Zea mays L.) under nonlimiting or water‐limited (rainfed or irrigated) conditions. The scientific formulations of the model and its test and validation was published elsewhere. The model can be used to (i) assess the overall site yield potential and its variability based on historical weather data, (ii) evaluate changes in attainable yield using different combinations of planting date, hybrid maturity, and plant density, (iii) analyze yield in relation to silking and maturity in a specific year, (iv) assess soil moisture status and explore options for irrigation management, and (v) conduct in‐season simulations to evaluate current crop status and predict final yield at maturity as a range of yield outcome probabilities based on historical climate data for the remainder of the growing season. Three examples are provided to demonstrate practical uses of the model. The software has a user‐friendly graphic interface, and includes complete documentation of model formulations, validation, user manual, and context‐sensitive help system. Settings of all internal parameters are transparent and modifiable by the user. Limitations of the software for practical uses, especially with regard to water stress and plant population, are also discussed.
The Affective and Cognitive Dimensions of Math Anxiety: A Cross-National Study
Authors: Ho Hsiu-Zu , Senturk Deniz , Lam Amy G. , Zimmer Jules M. , Hong Sehee , Okamoto Yukari , Chiu Sou-Yung , Nakazawa Yasuo , Wang Chang-Pei
Published: May 2006

In this study we focus on math anxiety, comparing its dimensions, levels, and relationship with mathematics achievement across samples of 6th-grade students from China, Taiwan, and the United States. The results of confirmatory factor analyses supported the theoretical distinction between affective and cognitive dimensions of math anxiety in all 3 national samples. The analyses of structural equation models provided evidence for the differential predictive validity of the 2 dimensions of math anxiety. Specifically, across the 3 national samples, the affective factor of math anxiety was significantly related to mathematics achievement in the negative direction. Gender by nation interactions were also found to be significant for both affective and cognitive math anxiety.
Fabrication and Characterization of Nanostructured and Thermosensitive Polymer Membranes for Wound Healing and Cell Grafting
Authors: Wang L.‐S. , Chow P.‐Y. , Phan T.‐T. , Lim I. J. , Yang Y.‐Y.
Published: May 2006

Nanostructured, transparent, and thermosensitive membranes synthesized by bicontinuous microemulsion polymerization of N‐isopropylacrylamide (NIPAAm), methyl methacrylate (MMA), and 2‐hydroxyethyl methacrylate (HEMA) using a polymerizable nonionic surfactant, ω‐methoxy poly(ethylene oxide)40 undecyl α‐methacrylate macromonomer have recently been reported. In this study, the synthesis and characterization of membranes with various compositions are presented in detail, focusing on the effects of environmental temperature and membrane composition on surface hydrophilicity, cell attachment, and detachment. The membranes synthesized with differing compositions have a nanoporous structure, and are transparent and thermosensitive in their swelling ratio and cell‐attachment characteristics. Decreasing the environmental temperature and the MMA content leads to an increase in the wettability of the membrane surface. In addition, both L929 murine neoplastic fibroblasts and primary human dermal fibroblasts can attach to and detach from the membranes with varying temperature. High cell‐attachment and ‐detachment efficiencies are achieved by optimizing membrane composition and environmental temperature. In addition, the membranes do not show significant cytotoxicity. These membranes have great potential for the construction of a new generation of dressings and cell‐delivery systems for wound healing.
Preparation, characteristics, and flocculation behavior of modified palygorskite–polyacrylamide ionic hybrids
Authors: Wang Meng , Qian Jinwen , Zheng Baoqing , Yang Wuyuan
Published: May 2006

A novel inorganic–organic hybrid with modified palygorskite (MPGS) and acrylamide was prepared with a heterogeneous redox initiator system composed of a reductive agent (MPGS) together with an oxidant (Ce4+). The MPGS–polyacrylamide (PAM) hybrids were characterized by X‐ray diffraction, 1H‐NMR, Fourier transform infrared spectroscopy, conductometry, viscometry, and size exclusion chromatography. The MPGS–PAM hybrid could be a starlike and ionic bond hybrid. The ionization behavior of the MPGS–PAM hybrid in deionized water depended strongly on its coil dimension and the palygorskite content in the hybrid. The flocculation performance of the MPGS–PAM hybrid in a kaolin suspension was also related to its intrinsic viscosity and the palygorskite content and was better than that of PAM, except for that of the MPGS–PAM hybrid with a high palygorskite content. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1494–1500, 2006
β‐lactoglobulin as a potential modulator of intestinal activity and morphology in neonatal piglets
Authors: Sutton Leonard F. , Alston‐Mills Brenda
Published: May 2006

Studies were conducted to determine the effects of the whey protein β‐lactoglobulin (blg) on the intestinal development and intestinal morphology in neonatal piglets. Two trials (5 and 28 days) were conducted on piglets in three separate groups. One group served as a control group while the remaining two were experimental groups based on diets. The two experimental diets were a bovine colostrum powder, one with supplementation with blg and the other without. The control group remained suckling on a sow. All groups were weaned on day 20 and placed onto a solid commercial piglet diet. Enzymatic activity, total DNA synthesis, crypt depth, and villus height were all parameters used to evaluate the effect of blg. Piglets fed a diet supplement with blg had the greatest total DNA after 5 days. Sow‐reared piglets had the greatest intestinal morphology development with regards to villus height. No significant differences were found in enzymatic activity between treatments. Anat Rec Part A 288A:601–608, 2006. © 2006 Wiley‐Liss, Inc.
Effects of growth rate on cell extract performance in cell‐free protein synthesis
Authors: Zawada James , Swartz James
Published: May 2006

Cell‐free protein synthesis is a useful research tool and now stands poised to compete with in vivo expression for commercial production of proteins. However, both the extract preparation and protein synthesis procedures must be scaled up. A key challenge is producing the required amount of biomass that also results in highly active cell‐free extracts. In this work, we show that the growth rate of the culture dramatically affects extract performance. Extracts prepared from cultures with a specific growth rate of 0.7/h or higher produced approximately 0.9 mg/mL of chloramphenicol acetyl transferase (CAT) in a batch reaction. In contrast, when the source culture growth rate was 0.3/h, the resulting extract produced only 0.5 mg/mL CAT. Examination of the ribosome content in the extracts revealed that the growth rate of the source cells strongly influenced the final ribosome concentration. Polysome analysis of cell‐free protein synthesis reactions indicated that about 22% of the total 70S ribosomes are in polysomes for all extracts regardless of growth rate. Furthermore, the overall specific production from the 70S ribosomes is about 22 CAT proteins per ribosome over the course of the reaction in all cases. It appears that rapid culture growth rates are essential for producing a productive extract. However, growth rate does not seem to influence specific ribosome activity. Rather, the increase in extract productivity is a result of a higher ribosome concentration. These results are important for cell‐free technology and also suggest an assay for intrinsic in vivo protein synthesis activity. © 2006 Wiley Periodicals, Inc.
Sequencing batch membrane biofilm reactor for simultaneous nitrogen and phosphorus removal: Novel application of membrane‐aerated biofilm
Authors: Terada Akihiko , Yamamoto Tetsuya , Tsuneda Satoshi , Hirata Akira
Published: May 2006

A sequencing batch membrane biofilm reactor (SBMBfR) was developed for simultaneous carbon, nitrogen, and phosphorus removal from wastewater. This reactor was composed of two functional parts: (1) a gas‐permeable membrane on which a nitrifying biofilm formed and (2) a bulk solution in which bacteria, mainly denitrifying polyphosphate‐accumulating organisms (DNPAOs), were suspended. The reactor was operated sequentially under anaerobic condition and then under membrane aeration condition in one cycle. During the anaerobic period, organic carbon was consumed by DNPAOs; this was accompanied by phosphate release. During the subsequent membrane aeration period, nitrifying bacteria utilized oxygen supplied directly to them from the inside of the membrane. Consequently, the nitrite and nitrate products diffused into the bulk solution, where they were used by DNPAOs as electron acceptors for phosphate uptake. In a long‐term sequencing batch operation, the mean removal efficiencies of total organic carbon (TOC), total nitrogen (T‐N), and total phosphorus (T‐P) under steady‐state condition were 99%, 96%, and 90%, respectively. In addition, fluorescence in situ hybridization (FISH) clearly demonstrated the difference in bacterial community structure between the membrane biofilm and the suspended sludge: ammonia‐oxidizing bacteria belonging to the Nitrosomonas group were dominant in the region adjacent to the membrane throughout the operation, and the occupation ratio of the well‐known polyphosphate‐accumulating organism (PAO) Candidatus “Accumulibacter phosphates” in the suspended sludge gradually increased to a maximum of 37%. © 2006 Wiley Periodicals, Inc.
Intermolecular Insertion of an N,N‐Heterocyclic Carbene into a Nonacidic CH Bond: Kinetics, Mechanism and Catalysis by (K‐HMDS)2 (HMDS=Hexamethyldisilazide)
Authors: Lloyd‐Jones Guy C. , Alder Roger W. , Owen‐Smith Gareth J. J.
Published: May 2006

The reaction of 2‐[13C]‐1‐ethyl‐3‐isopropyl‐3,4,5,6‐tetrahydropyrimidin‐1‐ium hexafluorophosphate ([13C1]‐1‐PF6) with a slight excess (1.03 equiv) of dimeric potassium hexamethyldisilazide (“(K‐HMDS)2”) in toluene generates 2‐[13C]‐3‐ethyl‐1‐isopropyl‐3,4,5,6‐tetrahydropyrimid‐2‐ylidene ([13C1]‐2). The hindered meta‐stable N,N‐heterocyclic carbene [13C1]‐2 thus generated undergoes a slow but quantitative reaction with toluene (the solvent) to generate the aminal 2‐[13C]‐2‐benzyl‐3‐ethyl‐1‐isopropylhexahydropyrimidine ([13C1]‐14) through formal CH insertion of C(2) (the “carbene carbon”) at the toluene methyl group. Despite a significant pKa mismatch (ΔpKa 1+ and toluene estimated to be ca. 16 in DMSO) the reaction shows all the characteristics of a deprotonation mechanism, the reaction rate being strongly dependent on the toluene para substituent (ρ=4.8(±0.3)), and displaying substantial and rate‐limiting primary (kH/kD=4.2(±0.6)) and secondary (kH/kD=1.18(±0.08)) kinetic isotope effects on the deuteration of the toluene methyl group. The reaction is catalysed by K‐HMDS, but proceeds without cross over between toluene methyl protons and does not involve an HMDS anion acting as base to generate a benzyl anion. Detailed analysis of the reaction kinetics/kinetic isotope effects demonstrates that a pseudo‐first‐order decay in 2 arises from a first‐order dependence on 2, a first‐order dependence on toluene (in large excess) and, in the catalytic manifold, a complex noninteger dependence on the K‐HMDS dimer. The rate is not satisfactorily predicted by equations based on the Brønsted salt‐effect catalysis law. However, the rate can be satisfactorily predicted by a mole‐fraction‐weighted net rate constant: −d[2]/dt=({x2 kuncat}+{(1−x2) kcat})[2]1[toluene]1, in which x2 is determined by a standard bimolecular complexation equilibrium term. The association constant (Ka) for rapid equilibrium–complexation of 2 with (K‐HMDS)2 to form [2(K‐HMDS)2] is extracted by nonlinear regression of the 13C NMR shift of C(2) in [13C1]‐2 versus [(K‐HMDS)2] yielding: Ka=62(±7) M−1; δC(2) in 2=237.0 ppm; δC(2) in [2(K‐HMDS)2]=226.8 ppm. It is thus concluded that there is discrete, albeit inefficient, molecular catalysis through the 1:1 carbene/(K‐HMDS)2 complex [2(K‐HMDS)2], which is found to react with toluene more rapidly than free 2 by a factor of 3.4 (=kcat/kuncat). The greater reactivity of the complex [2(K‐HMDS)2] over the free carbene (2) may arise from local Brønsted salt‐effect catalysis by the (K‐HMDS)2 liberated in the solvent cage upon reaction with toluene.
Structural information from quadrupolar nuclei in solid state NMR
Authors: Ashbrook Sharon E. , Duer Melinda J.
Published: May 2006

Solid‐state NMR has become the method of choice for determining details of molecular‐level structure in heterogeneous systems. Though spin‐1/2 nuclei still form the core of most such studies, quadrupolar nuclei are increasingly being used. This review assesses what is currently possible, from achieving high‐resolution spectra for quadrupolar nuclei (a prerequisite for most structure determination work), to forming correlation spectra which give qualitative details of spatial proximity of nuclei and the determination of internuclear distances, between quadrupolar spins and quadrupolar and spin‐1/2 nuclei. Examples are given of each method discussed, and the advantages and disadvantages of the various experiments for different possible applications are assessed. © 2006 Wiley Periodicals, Inc. Concepts Magn Reson Part A 28A: 183–248, 2006.
Characterization of melanocyte‐specific inducible Cre recombinase transgenic mice
Authors: Bosenberg Marcus , Muthusamy Viswanathan , Curley David P. , Wang Zhenxiong , Hobbs Cara , Nelson Betsy , Nogueira Cristina , Horner James W. , DePinho Ronald , Chin Lynda
Published: May 2006

Conditional Cre‐mediated recombination has emerged as a robust method of introducing somatic genetic alterations in an organ‐specific manner in the mouse. Here, we generated and characterized mice harboring a 4‐hydroxytamoxifen (OHT)‐inducible Cre recombinase‐estrogen receptor fusion transgene under the control of the melanocyte‐specific tyrosinase promoter, designated Tyr::CreERT2. Cre‐mediated recombination was induced in melanocytes in a spatially and temporally controlled manner upon administration of OHT and was documented in embryonic melanoblasts, follicular bulb melanocytes, dermal dendritic melanocytes, epidermal melanocytes of tail skin, and in putative melanocyte stem cells located within the follicular bulge. Functional evidence suggestive of recombination in follicular melanocyte stem cells included the presence of Cre‐mediated recombination in follicular bulb melanocytes 1 year after topical OHT administration, by which time several hair cycles have elapsed and the melanocytes residing in this location have undergone multiple rounds of apoptosis and replenishment. These Tyr:: CreERT2 transgenic mice represent a useful resource for the evaluation of melanocyte developmental genetics, the characterization of melanocyte stem cell function and dynamics, and the construction of refined mouse models of malignant melanoma. genesis 44:262–267, 2006. Published 2006 Wiley‐Liss, Inc.
Cancer progression by non‐clonal chromosome aberrations
Authors: Heng Henry H.Q. , Bremer Steven W. , Stevens Joshua , Ye Karen J. , Miller Fred , Liu Gou , Ye Christine J.
Published: May 2006

The establishment of the correct conceptual framework is vital to any scientific discipline including cancer research. Influenced by hematologic cancer studies, the current cancer concept focuses on the stepwise patterns of progression as defined by specific recurrent genetic aberrations. This concept has faced a tough challenge as the majority of cancer cases follow non‐linear patterns and display stochastic progression. In light of the recent discovery that genomic instability is directly linked to stochastic non‐clonal chromosome aberrations (NCCAs), and that cancer progression can be characterized as a dynamic relationship between NCCAs and recurrent clonal chromosome aberrations (CCAs), we propose that the dynamics of NCCAs is a key element for karyotypic evolution in solid tumors. To support this viewpoint, we briefly discuss various basic elements responsible for cancer initiation and progression within an evolutionary context. We argue that even though stochastic changes can be detected at various levels of genetic organization, such as at the gene level and epigenetic level, it is primarily detected at the chromosomal or genome level. Thus, NCCA‐mediated genomic variation plays a dominant role in cancer progression. To further illustrate the involvement of NCCA/CCA cycles in the pattern of cancer evolution, four cancer evolutionary models have been proposed based on the comparative analysis of karyotype patterns of various types of cancer. J. Cell. Biochem. © 2006 Wiley‐Liss, Inc.
Biological significance and development of practical synthesis of biotin
Authors: Seki Masahiko
Published: May 2006

Biotin (1), a water‐soluble B series vitamin, distributes widely in microorganisms, plants, and animals. Biosynthesis of 1 involves five steps sequence starting from pimelic acid. The last step, a transformation from dethiobiotin (DTB) to 1, includes an iron clusters‐mediated radical process. The compound 1 is a cofactor of carboxylation enzymes and plays crucial roles in the metabolism of fatty acids, sugars, and α‐amino acids. In addition to the increasing application to feed additives, recent reports have revealed that 1 enhances insulin secretion in animals, suggesting it for a promising therapeutic candidate for an anti‐diabetes drug. The remarkably strong affinity of 1 with avidin and streptavidin has been extensively applied for such technologies as photoaffinity labeling. Among the number of approaches to 1 so far developed in 50 years, a synthesis using L‐cysteine and thiolactone as a starting material and a key intermediate, respectively, represents one of the best routes leading to 1, because of short steps, high yield, use of inexpensive reagents, and ease of operation. © 2006 Wiley Periodicals, Inc. Med Res Rev, 26, No. 4, 434–482, 2006
Lipid signal extraction by SLIM: Application to 1H MR spectroscopic imaging of human calf muscles
Authors: Dong Zhengchao , Hwang Jong‐Hee
Published: May 2006

The measurement of intramyocellular lipid (IMCL) using in vivo 1H MRS is important for better understanding muscle physiology. However, the accurate measurement of IMCL in muscle adjacent to subcutaneous fat (SF) and bone marrow (BM) is often hampered by contaminations from the fat. In this article a new postacquisition processing method is proposed that selectively removes unwanted lipid signals based on the spectral localization by imaging (SLIM) technique, which can localize spectra from arbitrarily shaped regions. The effectiveness of this lipid extraction method is demonstrated by both computer simulation and in vivo experiments in the human calf. The advantage of this method is that unwanted lipid signal, such as SF signal, can be selectively and completely removed. After the contaminating fat signals are removed, the quality of muscle spectra adjacent to SF improves such that it becomes comparable to that in uncontaminated muscle regions in 1H MRSI of the calf. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Supportive employment for individuals with chronic schizophrenia: the case for a National Health Service community‐based sheltered workshop
Authors: Creegan Shelagh , Williams Fiona L.R.
Published: May 2006

A pilot project was established from 1992 to 1994 to provide people with chronic schizophrenia living in Dundee, Scotland, with a National Health Service sheltered workshop that would be fully integrated into the local business community. Of the 43 clients who attended the sheltered workshop, 38 agreed to take part in the project. Typical attenders were single, middle‐aged men with schizophrenia. Twenty‐five per cent had spent more than two years in hospital; 75% had been unemployed for more than five years. The clients' use of National Health Service day facilities more than halved while attending the workshop. Their hospital readmission rates were low (16%) compared with the local readmission rates for people with schizophrenia in Dundee (86%). A training approach based on the general principles of social skills training contributed to positive vocational outcomes for one‐third of the workshop clients.

The findings suggest that the onus of responsibility for providing work for many individuals with schizophrenia remains with the National Health Service, and in particular, occupational therapy. Occupational therapy staff must assess their clients effectively and provide quality training leading to opportunities for paid employment. These results have implications for the training of occupational therapy staff and also for the staffing structure in sheltered workshops. Copyright © 1997 Whurr Publishers Ltd.
A qualitative study of amlodipine and its related compounds by electrospray ionization tandem mass spectrometry
Authors: Gibbons John , Pugh Jonathan , Dimopoulos‐Italiano Gina , Pike Richard
Published: May 2006

A comprehensive structural analysis of amlodipine and certain related compounds was performed by electrospray ionization tandem mass spectrometry. Triple quadrupole and quadrupole time‐of‐flight instruments were used to provide collision‐induced dissociation and accurate mass measurement for selected product and second‐generation product ions. A unique ion rearrangement was observed, which was found to be characteristic of certain dihydropyridines. This study provides a fundamental understanding of the fragmentation of these compounds. The structural elucidation of an unknown impurity is presented as an example. Copyright © 2006 John Wiley & Sons, Ltd.
Identification of isocephalomannine in the presence of cephalomannine isomers and alkali metal ion adducts in a paclitaxel active pharmaceutical ingredient using electrospray tandem mass spectrometry
Authors: Vivekanandan Kannan , Swamy Madugundu Guru , Prasad Sudhanand , Mukherjee Rama , Burman Anand C.
Published: May 2006

A strategy is developed for the identification of isocephalomannine in the presence of alkali metal ion adducts and other cephalomannine isomers in a paclitaxel active pharmaceutical ingredient. Intact molecular ion analyses and a sub‐structural study have been performed for the differentiation of isocephalomannine (2‐debenzoylpaclitaxel‐2‐pentenoate) from cephalomannine and 7‐epi‐cephalomannine. A comparative study of the cephalomannine isomers was carried out using molecular ions (MS) and fragmentation patterns (MS/MS) for sub‐structural analysis. An attempt has been made to identify isocephalomannine in Cremophor® EL formulations. Copyright © 2006 John Wiley & Sons, Ltd.
Ionic liquid matrices with phosphoric acid as matrix additive for the facilitated analysis of phosphopeptides by matrix‐assisted laser desorption/ionization mass spectrometry
Authors: Tholey Andreas
Published: May 2006

Matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS) is a powerful tool for the analysis and characterization of protein phosphorylation on the peptide level. In this study, the applicability of ionic liquid matrices (ILM) formed by combination of the crystalline MALDI matrix 2,5‐dihydroxybenzoic acid (DHB) with pyridine or n‐butylamine was tested for the analysis of phosphopeptides. Low ionization efficiency in both positive and negative ion mode was observed in acid‐free sample preparations. Upon addition of 0.1% trifluoroacetic acid (TFA), ion formation was increased, but analogously to the situation described earlier for pure DHB, best results were obtained upon use of 1% phosphoric acid as matrix additive. The samples prepared in this way were significantly more homogeneous than preparations with pure DHB, thus avoiding the need for time‐consuming search for hot spots. Other characteristics like metastable fragmentation of phosphopeptides did not differ from that observed in classical preparations. The limits of detection for synthetic phosphopeptides and singly or multiply phosphorylated peptides from tryptic digests of α‐ and β‐casein were comparable with those obtained when using pure DHB; in some cases even higher signal intensities could be observed in the ILM. The use of ILM in combination with 1% phosphoric acid as matrix additive significantly facilitates analysis of phosphopeptides by MALDI‐MS. Copyright © 2006 John Wiley & Sons, Ltd.
Experimental history: the appeal of postmodernism in historiography
Authors: Xin Chen
Published: May 2006

Use, truth and time constitute the basic elements of the epistemological structure of history. That structure went through three stages: pre-modern (from ancient times to the late eighteenth century, before the professionalization of history took place), modern (the period of professional history, from the late eighteenth century to the 1970s), and post modern (post 1970s). In these three stages, use, truth, and time successively occupied the core of the epistemological structure of history. Postmodernist history, which puts time at the core of its epistemology, is an extreme form of historicism. Even more than historicism, it has emphasized the determining effect of time and change on historical truth and historical consciousness. The privatization of historical narrative and reading has prodded history to become experimental. Experimental history no longer proclaims the truth about the past. Instead, under specific historical circumstances, it strives to produce texts that will be recognized by individual historians and provides these texts to readers, who will make their own judgments. Whether these texts are true will be decided through the uses they produce. In this way, any historiographical practice will be an experiment conducted by an historian in the present and that will consist in searching for the truth about the past. The success of this experiment will depend entirely on the experimental environment, that is, on the conditions provided by the reading environment.
The expansion of water communication and transportation between north and south China during the Six dynasties
Authors: Dezhang He
Published: May 2006

Although a split and turbulent age, the Wei, Jin, and Northern and Southern dynasties, known as the Six dynasties, witnessed a continuous expansion of waterway communication and transportation between north and south China. A significant waterway from Hangzhou to Tianjin held the greatest potential for development during this period, eventually leading to the construction of the Grand Canal in the Sui dynasty.
The merchants of Chang’an in the Sui and Tang dynasties
Authors: Pingshuan Xue
Published: May 2006

As the capital of the Sui and Tang dynasties, Chang’an brought together large numbers of high-ranking officials, aristocrats, local residents, and sojourners. The promise of profits caused by the high demand for consumer goods attracted merchants. Chang’an was also the starting point of the renowned Silk Road. For all these reasons, Chang’an became a gathering point for Small and medium-scale merchants, rich merchants, ethnic-minority merchants, and foreign merchants. All these merchants engaged in a wide variety of business activities and made money by surprisingly diverse means. Those with great economic power were quite active politically. The activities of these merchants symbolize the unprecedented growth of commerce in Chang’an and reveal the high level of development of urban trade in the Sui and the Tang dynasties.
The turning couples on an elliptic particle settling in a vertical channel
Authors: Huang Peter Y. , Feng Jimmy , Joseph Daniel D.
Published: May 2006

We do a direct two-dimensional finite-elment simulation of the Navier–Stokes equations and compute the forces which turn an ellipse settling in a vertical channel of viscous fluid in a regime in which the ellipse oscillates under the action of vortex shedding. Turning this way and that is induced by large and unequal values of negative pressure at the rear separation points which are here identified with the two points on the back face where the shear stress vanishes. The main restoring mechanism which turns the broadside of the ellipse perpendicular to the fall is the high pressure at the ‘stagnation point’ on the front face, as in potential flow, which is here identified with the one point on the front face where the shear stress vanishes.
Experimental assessment of fractal scale-similarity in turbulent flows. Part 1. One-dimensional intersections
Authors: Frederiksen Richard D. , Dahm Werner J. A. , Dowling David R.
Published: May 2006

Results are presented from an assessment of the applicability of fractal scale-similarity in the spatio–temporal structure of Sc [Gt ] 1 conserved scalar fields ζ(x, t) and scalar energy dissipation rate fields ∇(x, t) in turbulent flows. Over 2 million spatial and temporal intersections were analysed from fully resolved three-dimensional (256) spatial measurements as well as fully resolved four-dimensional spatio–temporal measurements containing up to 3 million points. Statistical criteria were used to assess both deterministic and stochastic fractal scale-similarity and to differentiate between fractal and random sets. Results span the range of spatio–temporal scales from the scalar diffusion scales (ΛD, TD) to the viscous diffusion scales (Λv, Tv) and to the outer scales (δ, Tδ). Over this entire range of scales, slightly over 99.0% of all intersections with the scalar dissipation support geometry showed scale-similarity as fractal as stochastically self-similar fBm sets having the same record length. Dissipation values above the mean were found to have support dimension D = 0.66. The dissipation support dimension decreased sharply with increasing dissipation values. Virtually no intersections showed scaling as random as a random set with the same relative cover. In contrast, intersections with scalar isosurfaces showed scaling only approximately as fractal as a corresponding fBm set and only over the range of spatio–temporal scales between (ΛD, TD) and (Λv, Tv). On these inner scales the isosurface dimension was D = 0.48 and was largely independent of the isoscalar value. At larger scales, scalar isosurfaces showed no fractal scale-similarity. In contrast, isoscalar level crossing sets showed no fractal scale-similarity over any range of scales, even though the scalar dissipation support geometry for the same data is clearly fractal. These results were found to be unaffected by noise.
Diffusional-thermal instability of diffusion flames
Authors: Kim J. S. , Williams F. A. , Ronney P. D.
Published: May 2006

The diffusional–thermal instability, which gives rise to striped quenching patterns that have been observed for diffusion flames, is analysed by studying the model of a one-dimensional convective diffusion flame in the diffusion-flame regime of activation-energy asymptotics. Attention is focused principally on near-extinction conditions with Lewis numbers less than unity, in which the reactants with high diffusivity diffuse into the strong segments of the reaction sheet, so that the regions between the strong segments become deficient in reactant and subject to the local quenching that leads to the striped patterns. This analysis differs from other flame stability analyses in that the complete description of the dispersion relation is obtained from a composite expansion of the results of an analysis with the conventional convective-diffusive scaling and one with reaction-zone scaling. The results predict that striped patterns will occur, for flames sufficiently close to quasi-steady extinction, with a finite wavenumber that in convective–diffusive scaling is proportional to the cube root of the Zel'dovich number. The convective–diffusive response contributes to the stabilization of long-wavelength disturbances by through positive excess enthalpies by which the flame becomes more resistant to instability, while the reaction-zone response provides stabilization of short-wavelength disturbances by transverse diffusion, within the reactive inner layer, which relaxes the perturbed scalar fields towards their unperturbed states. As quasi-steady extinction is approached, marginal stability arises first at an intermediate range between these two scalings. Parametric results for this bifurcation point are obtained through numerical solutions of the associated generalized eigenvalue problems. Comparisons with measured pattern dimensions for different sets of reactants and diluents reveal excellent qualitative agreement.
Cellular Analyses of the Mitotic Region in theCaenorhabditis elegansAdult Germ Line
Authors: Crittenden Sarah L. , Leonhard Kimberly A. , Byrd Dana T. , Kimble Judith
Published: May 2006

The Caenorhabditis elegans germ line provides a model for understanding how signaling from a stem cell niche promotes continued mitotic divisions at the expense of differentiation. Here we report cellular analyses designed to identify germline stem cells within the germline mitotic region of adult hermaphrodites. Our results support several conclusions. First, all germ cells within the mitotic region are actively cycling, as visualized by bromodeoxyuridine (BrdU) labeling. No quiescent cells were found. Second, germ cells in the mitotic region lose BrdU label uniformly, either by movement of labeled cells into the meiotic region or by dilution, probably due to replication. No label-retaining cells were found in the mitotic region. Third, the distal tip cell niche extends processes that nearly encircle adjacent germ cells, a phenomenon that is likely to anchor the distal-most germ cells within the niche. Fourth, germline mitoses are not oriented reproducibly, even within the immediate confines of the niche. We propose that germ cells in the distal-most rows of the mitotic region serve as stem cells and more proximal germ cells embark on the path to differentiation. We also propose that C. elegans adult germline stem cells are maintained by proximity to the niche rather than by programmed asymmetric divisions.
Sequencing and analysis of 10,967 full-length cDNA clones fromXenopus laevisandXenopus tropicalisreveals post-tetraploidization transcriptome remodeling
Authors: Morin Ryan D. , Chang Elbert , Petrescu Anca , Liao Nancy , Griffith Malachi , Kirkpatrick Robert , Butterfield Yaron S. , Young Alice C. , Stott Jeffrey , Barber Sarah , Babakaiff Ryan , Dickson Mark C. , Matsuo Corey , Wong David , Yang George S. , Smailus Duane E. , Wetherby Keith D. , Kwong Peggy N. , Grimwood Jane , Brinkley Charles P. , Brown-John Mabel , Reddix-Dugue Natalie D. , Mayo Michael , Schmutz Jeremy , Beland Jaclyn , Park Morgan , Gibson Susan , Olson Teika , Bouffard Gerard G. , Tsai Miranda , Featherstone Ruth , Chand Steve , Siddiqui Asim S. , Jang Wonhee , Lee Ed , Klein Steven L. , Blakesley Robert W. , Zeeberg Barry R. , Narasimhan Sudarshan , Weinstein John N. , Pennacchio Christa Prange , Myers Richard M. , Green Eric D. , Wagner Lukas , Gerhard Daniela S. , Marra Marco A. , Jones Steven J.M. , Holt Robert A.
Published: May 2006

Sequencing of full-insert clones from full-length cDNA libraries from bothXenopus laevisandXenopus tropicalishas been ongoing as part of theXenopusGene Collection Initiative. Here we present 10,967 full ORF verified cDNA clones (8049 fromX. laevisand 2918 fromX. tropicalis) as a community resource. Because the genome ofX. laevis,but notX. tropicalis,has undergone allotetraploidization, comparison of coding sequences from these two clawed (pipid) frogs provides a unique angle for exploring the molecular evolution of duplicate genes. Within our clone set, we have identified 445 gene trios, each comprised of an allotetraploidization-derivedX. laevisgene pair and their sharedX. tropicalisortholog. PairwisedN/dS,comparisons within trios show strong evidence for purifying selection acting on all three members. However,dN/dSratios betweenX. laevisgene pairs are elevated relative to theirX. tropicalisortholog. This difference is highly significant and indicates an overall relaxation of selective pressures on duplicated gene pairs. We have found that the paralogs that have been lost since the tetraploidization event are enriched for several molecular functions, but have found no such enrichment in the extant paralogs. Approximately 14% of the paralogous pairs analyzed here also show differential expression indicative of subfunctionalization.
The crystal structure of Mycobacterium tuberculosis adenylate kinase in complex with two molecules of ADP and Mg2+ supports an associative mechanism for phosphoryl transfer
Authors: Bellinzoni Marco , Haouz Ahmed , Graña Martin , Munier‐Lehmann Hélène , Shepard William , Alzari Pedro M.
Published: May 2006

The crystal structure of Mycobacterium tuberculosis adenylate kinase (MtAK) in complex with two ADP molecules and Mg2+ has been determined at 1.9 Å resolution. Comparison with the solution structure of the enzyme, obtained in the absence of substrates, shows significant conformational changes of the LID and NMP‐binding domains upon substrate binding. The ternary complex represents the state of the enzyme at the start of the backward reaction (ATP synthesis). The structure is consistent with a direct nucleophilic attack of a terminal oxygen from the acceptor ADP molecule on the β‐phosphate from the donor substrate, and both the geometry and the distribution of positive charge in the active site support the hypothesis of an associative mechanism for phosphoryl transfer.
Conversion of trypsin to a functional threonine protease
Authors: Baird Teaster T. , Wright William D. , Craik Charles S.
Published: May 2006

The hydroxyl group of a serine residue at position 195 acts as a nucleophile in the catalytic mechanism of the serine proteases. However, the chemically similar residue, threonine, is rarely used in similar functional context. Our structural modeling suggests that the Ser 195 → Thr trypsin variant is inactive due to negative steric interaction between the methyl group on the β‐carbon of Thr 195 and the disulfide bridge formed by cysteines 42 and 58. By simultaneously truncating residues 42 and 58 and substituting Ser 195 with threonine, we have successfully converted the classic serine protease trypsin to a functional threonine protease. Substitution of residue 42 with alanine and residue 58 with alanine or valine in the presence of threonine 195 results in trypsin variants that are 102–104‐fold less active than wild type in kcat/KM but >106‐fold more active than the Ser 195 → Thr single variant. The substitutions do not alter the substrate specificity of the enzyme in the P1′– P4′ positions. Removal of the disulfide bridge decreases the overall thermostability of the enzyme, but it is partially rescued by the presence of threonine at position 195.
Socio‐environmental influences on adolescents’ alcohol outcome expectancies: a prospective analysis
Authors: Martino Steven C. , Collins Rebecca L. , Ellickson Phyllis L. , Schell Terry L. , McCaffrey Daniel
Published: May 2006

Aims  To investigate the prospective influence of social influence and social bonding variables on the development of alcohol outcome expectancies among adolescents with and without drinking experience.

Design  Longitudinal data from students in the control schools of a field trial designed to evaluate a school‐based drug prevention program.

Setting  A total of 19 middle schools in South Dakota, USA.

Measurements  An alcohol outcome expectancy scale administered to 1410 students in grades 8 and 9. After using confirmatory factor analysis (CFA) to develop an expectancies measure, multiple‐group (grade 8 drinkers versus grade 8 non‐drinkers) path analysis was used to model 9th grade alcohol expectancies. Grade 8 social influence and bonding variables were used as predictors, controlling for grade 8 expectancies.

Findings  At the bivariate level, peer and adult influences and social bonding variables were related consistently to alcohol outcome expectancies among drinkers and non‐drinkers. A bivariate relationship between alcohol advertising and alcohol expectancies was found among drinkers only. In the multivariate model, greater alcohol use by important adults predicted independently increased alcohol positivity among drinkers; greater perceived approval of alcohol use by parents and peers predicted diminished perceived potency of alcohol among non‐drinkers. Advertisement exposure and social bonding variables were not independent predictors of alcohol expectancies in the multivariate model.

Conclusions  These findings suggest that attempts to alter adolescents’ alcohol expectancies are likely to fail unless they address the influence of immediate social models on these beliefs.