bluuebunny/crossref_metadata_2025 huggingface dataset:
Unravelling the origins and P-T-t evolution of the allochthonous Sobrado unit (Órdenes Complex, NW Iberia) using combined U-Pb titanite, monazite and zircon geochronology and REE geochemistry
Authors: Benítez-Pérez José Manuel , Castiñeiras Pedro , Gómez-Barreiro Juan , Martínez Catalán José Ramón , Kylander-Clark Andrew , Holdsworth Robert
Published: April 2020

Abstract. The Sobrado unit, within the upper part of the Órdenes complex (NW Iberia) represents an allochthonous tectonic slice of exhumed high grade metamorphic rocks formed during a complex sequence of orogenic processes in the middle to lower crust. In order to constrain those processes, U-Pb geochronology and REE analyses of accessory minerals in migmatitic paragneisses (monazite, zircon), and mylonitic amphibolites (titanite) were conducted using LASS-ICP-MS. The youngest metamorphic zircon age obtained co-incides with a Middle Devonian concordia monazite age (~ 385 Ma) and is interpreted to represent the minimum age of the Sobrado high-P granulite-facies metamorphism that occurred during the early stages of the Variscan Orogeny. Metamorphic titanites from the mylonitic amphibolites yield a Late Devonian age (~ 365 Ma), and track the progressive exhumation of the Sobrado unit. In zircon, cathodoluminescence images and REE analyses allow two aliquots with different origins in the paragneiss to be distinguished. An Early Ordovician age (~ 490 Ma) was obtained for metamorphic zircons, employing the TuffZirc algorithm, although with a large analytical dispersion. This age is considered to mark the onset of granulite-facies metamorphism in the Sobrado unit under intermediate-P conditions, and related to intrusive magmatism and coeval burial in a magmatic arc setting. A maximum depositional age for the Sobrado unit is established in the late Cambrian (~ 503 Ma). The zircon dataset also record several inherited populations. The youngest cogenetic set of zircons yield a crystallization age from TuffZirc algorithm of ~ 530 Ma and are thought to be related to the peri-Gondwana magmatic arc. The additional presence of inherited zircons older than ~ 530 Ma is interpreted as suggesting a West African Craton provenance.
Ainda podemos escapar do Homo destructor? Um apelo à lucidez e à coragem
Authors: Vieira Paulo Freire , Gasparini Marina Favrim
Published: April 2020

Resenha do livro:Gancille, J. M. Ne plus se mentir. Petit exercice de lucidité par temps d'effondrement écologique. Paris: Rue de l'échiquier, 2019.
Perceived Assessment Instructional Skill Needed by Primary School Teachers for Improving Teaching in Enugu State
Authors: Ebizie Elizabeth N. , Njoku Obiageli C. , Oraelosi Charles A. , Ejiofor Juliana N. , Amaka Okpala Edith , Otu Mkpoikanke Sunday
Published: April 2020

This study was carried out to investigate the perceived assessment instructional skill needed by primary school teachers for improving teaching in Enugu State, Nigeria. Two research questions and two null hypotheses guided the study. Descriptive survey design was used in the study. The population of the study consisted of 10, 415 public primary school teachers in Enugu State.  Sample size of the study was 1,196 teachers, comprising of 579 males and 617 female teachers. Multistage sampling technique was used in the selection of the sample size. Iinstrument used for data collection was ‘Perceived Assessment Instructional Skill Needed by Teachers Questionnaire (PAISNTQ). To determine the internal consistency of the instrument, Cronbach Alpha was usedand the result yielded 0.87. The data collected from questionnaire were analyzed using mean, standard deviation and T-test statistics. The results of the analysis revealed that assessment instructional skills teachers are: assessing the area of pupils’ needs through observation; finding out areas of weakness and strength in pupils by asking them questions; assigning homework, quiz and examination to pupils. Also, the results of the analysis revealed that there is no statistically significant difference in the mean rating of male and female teachers on the perceived assessment instructional skill needed by primary school teachers for improved teaching; and that there is no statistically significant difference in the mean rating of teachers in urban and rural public primary schools on the perceived assessment instructional skills needed by primary school teachers for improved teaching.  Based on the findings of the study, the researchers recommended, among others, that the assessment instructional skills discussed in this study should be integrated into the teacher education curriculum; and that primary school teachers should be constantly appraised in the area of assessment instructional skills.
Parliamentary Scrutiny of Law Reform in Albania
Authors: Sallavaci Oriola
Published: April 2020

Parliamentary Scrutiny of Law Reform in Albania: Bodies, Procedures and Methods

This article throws light on the parliamentary scrutiny of law reform in Albania, which so far has not received sufficient attention in academic literature. The article provides a review of the bodies, procedures and mechanisms for the scrutiny of legal reform, as specified in the Constitution of Albania, Parliament’s Rules of Procedure and other specific statutes. Research on the activities of these bodies during the past three years, as reported by the official sources, throws light on the problematic aspects of their work and enables recommendations to be made which will lead to a more effective role of Parliament in legal reform. This is paramount considering the past few years of political instability in the country, at a time when Albanian’s European Integration is at stake
Development of bacterial resistance during treatment with topical gentamicin for chronic rhinosinusitis in patients with cystic fibrosis and primary ciliary dyskinesis. Retrospective case series
Authors: Kisiel Marta , Sjölander Isabella , Klar Agnes , Asplund Stenkvist Monika , Laurell Göran
Published: April 2020

Background: The management of chronic rhinosinusitis (CRS) in patients with cystic fibrosis (CF) and primary ciliary dyskinesia (PCD) is still a challenge. At our institution we have used gentamycin nasal spray, extemporaneously produced, for prophylactic treatment of moderate-to-severe CRS. The aim of this study was to investigate the gentamycin susceptibility of bacteria in sputum samples in CF and PCD patients treated for CRS. Methodology: Patients with CF and PCD who were prescribed gentamycin nasal spray for CRS and had sputum bacterial cultures taken pre-treatment and followed-up at least once after ≥6 months were retrospectively included. Microbiological data were descriptively analysed in terms of bacterial species and resistance to gentamycin. Results: A case series of 17 CF and 12 PCD patients passed the inclusion criteria. Of those cases, three (18%) CF patients and one (8%) PCD patient developed resistance to gentamycin during treatment with gentamycin nasal spray. In all four cases, the resistant bacterial isolates were P. aeruginosa. Additionally, two CF patients already had P. aeruginosa  isolates resistant to gentamycin in the pre-treatment culture. In further two CF patients, the multi-resistant Burgdorferi cepacia complex, including gentamycin resistance, was identified. P. aeruginosa  and S. aureus  in CF and P. aeruginosa and H. influenza  in PCD were the predominant bacterial species. Conclusions: The study showed that there was moderate incidence of gentamycin resistance in CF and PCD patients at our institution. However, further prospective studies are needed to confirm the outcomes.
Characterizing Rapists and Their Victims in Select Nigeria Newspapers
Authors: Tade Oludayo , Udechukwu Collins
Published: April 2020

While offender and victim characterization offers clues to devising preventive strategies and victim therapy, existing studies in Nigeria are yet to capture this empirically. Using two national dailies, about 331 rape cases have been analyzed. The rapists were found to be of the age group 18–55 years. The victims’ age has been reported to be between 1 and 20 years. Rape victims were mostly females (>90%) compared to males. Most of the rapists are labeled as familiar foes meaning, father, relatives, or neighbors. Third-party guardianship is mentioned as predatory.
The Age Pension Means Tests: Contorting Australian Retirement
Authors: Asher Anthony , De Ravin John
Published: April 2020

Most Australian retirees are likely to be subject to the Age Pension assets or income test at some point. Evidence is that many retirees adapt their consumption to increase Age Pension entitlements, but long-term implications are difficult to determine—even if the current rules were to remain in place. This chapter evaluates the current approach to means testing against the principles set out in a Department of Social Services discussion paper on this topic. We evaluate the implied “effective marginal tax rates” (EMTRs) on the assets of part pensioners who are subject to the assets test. We find that depending on a variety of parameters such as assumed future earnings rates, demographic status, drawdown strategy and the base level of assets held, the EMTRs are high enough to explain material distortions to savings decisions of those still in employment, and the spending and investment decisions of retirees. Optimal decisions in this context require contorted retirement strategies that do not appear to be in anyone’s interest. Some possible remedies are suggested, which should include incorporating the value of the principal residence within the assets test. The chapter therefore illustrates the application of principled analysis to policy issues of this sort.
High-Chromium (9-12Cr) Steels: Creep Enhancement by Conventional Thermomechanical Treatments
Authors: Vivas Javier , San-Martin David , G. Caballero Francisca , Capdevila Carlos
Published: April 2020

There is a worldwide need to develop materials for advanced power plants with steam temperatures of 700°C and above which have the capacity to achieve high efficiency and low CO2 emissions. This request involves the development of new grades of 9-12Cr heat-resistant steels, with a nanostructured martensite, mainly focusing on the long-term creep rupture strength of base metal and welded joints, creep-fatigue properties, and microstructure evolution during exposure at such elevated temperatures. The main shortcomings of actual 9-12Cr high-chromium steels are that the creep resistance is not enough to fulfill the engineering requirements at temperatures higher than 600°C and the material undergoes a cyclic softening. Creep strength at high temperature could be improved by a microstructural optimization through nano-precipitation, guided by computational thermodynamics, and thermomechanical control process optimization.
Neurocognitive Dysfunction and Diabetic Foot
Authors: A. Fisher Caroline
Published: April 2020

Diabetic foot ulcers are one of the most serious complications associated with diabetes. People with diabetes experience an accelerated rate of age-related cognitive decline, and comorbid complications increase the likelihood of neurocognitive attenuation. The current body of research into neurocognitive functioning in individuals with diabetic foot ulcers is small, but suggests significantly increased rates of neurocognitive dysfunction, and that up to one quarter of this cohort have cognitive functioning consistent with dementia samples. This has implications for utilising disease self-management as the primary treatment model. Neurocognitive deficits mean that understanding, retaining, and adhering to management recommendations are likely to be difficult in this group. Further research is needed in this area to determine the specific neurocognitive profile associated with diabetic foot, including which cognitive domains are the most impacted. The provision of a framework for tailoring management strategies to assist this group with more efficacious disease management is also required.
Effect of Molecular Structure Modification and Nano-Doping on Charge Transportation of Polyimide Films for Winding Insulation
Authors: Du Boxue , Xu Ranran , Xing Jiwen , Li Jin
Published: April 2020

Polyimide (PI) is widely employed as winding insulation in high voltage devices, such as extra-high voltage electric reactor and inverter-fed motor. The injection and accumulation of charges on the surface of PI films will lead to electrical field distortion and reduced lifespan of winding insulation, especially for the operation environment of high temperature and high voltage. This chapter focuses on effects of surface molecular modification and nanoparticles on dynamic characteristics of surface charge and space charge of pure PI films, including three sections. The effect of molecular structure on the surface charge dynamics of PI films was studied firstly. The chapter investigated that how molecular structure affects surface charge of polyimide nanocomposite films. Furthermore, the effect of surface molecular modification on space charge characteristics of multilayer PI films was researched. The results illustrate that surface molecular modification and nanoparticles can comprehensively suppress space charge accumulation and improve dielectric property.
Novel Single Hematophagous Insect RNA Detection Method Supports Its Use as Sentinels to Survey Flaviviruses Circulation
Authors: Sá Teles de Oliveira Molina Juliana , Moreira dos Santos Carmo Andreia , Lopes Pereira Gabriel , Abrantes de Andrade Leticia , Trovalim Jordão Felipe , Buzinaro Suzuki Rodrigo , Prado Rolim de Oliveira Luana , Diniz Cabral Aline , Aparecida Sperança Márcia
Published: April 2020

Anthropogenic actions, including deforestation, disorganized urbanization, and globalization, contribute to emergence and reemergence of arboviruses worldwide, where Flavivirus is the most prevalent, and its continuous monitoring can help in preventive control strategies. Thus, the aim of this study was to detect flavivirus RNA in single hematophagous insects, which are used as sentinels. Total RNA was extracted from six Aedes aegypti stored since 2003 and from 100 Culicidae and collected through CDC trap in a public park of a Brazilian Northwest city of São Paulo State. Flavivirus was detected through RT/PCR targeting 230–250 bp of the RNA polymerase coding sequence (NS5). PCR amplicons were sequenced by Sanger method, used in comparative analysis over Basic Local Alignment Search Tool (BLAST) in GenBank, and subjected to Neighbor-Joining phylogenetic analyses. Efficiency of Flavivirus diagnosis was confirmed by detection of Dengue virus serotype 2 in Ae. aegypti. From the 100 collected insects, 19 were positive for Culex flavivirus (CxFV). NS5 partial sequence phylogenetic analysis clustered all CxFV in one branch separated from vertebrate flaviviruses, being applicable to the identification of Flavivirus species. The dipteran RNA extraction methodology described in this work supports detection of flaviviruses in single insects maintained in 80% ethanol, which can be used to constant arbovirus surveillance.
An Analysis of Service Failures and Recovery Strategies in the Turkish Third Party Logistics Service Industry
Authors: Gidener Nazlı Gülfem , Deveci Durmuş Ali
Published: April 2020

Service literature indicates that both service failure and service recovery have a strong impact on the business relationships between service providers and their customers. The purpose of this research is twofold: to explore and analyze the most common service failures and implemented recovery strategies in Turkish third party logistics service industry and examine their impact on business relationships. Critical Incident Technique (CIT) was used. Thus, information on critical incidents were collected from both third party logistics service providers (3PLs) and their customers, failures and recovery strategies were categorized and the impact of service failures and recovery strategies on future relationships between customers and 3PLs examined. The findings indicate that service failures are most frequently encountered in customer services and port operations and that symbolic service recovery is the most common recovery strategy implemented by third party logistics service providers. The findings also show that third party logistics service providers and carriers are the most common sources of failure in third party logistics services.
Comparative transcriptomics characterized the distinct biosynthetic abilities of terpenoid and paeoniflorin biosynthesis in herbaceous peony strains
Authors: Lu Baowei , An Fengxia , Cao Liangjing , Gao Qian , Wang Xuan , Yang Yongjian , Liu Pengming , Yang Baoliang , Chen Tong , Li Xin-Chang , Chen Qinghua , Liu Jun
Published: April 2020

The herbaceous peony (Paeonia lactiflora Pall.) is a perennial flowering plant of the Paeoniaceae species that is widely cultivated for medical and ornamental uses. The monoterpene glucoside paeoniflorin and its derivatives are the active compounds of the P. lactiflora roots. However, the gene regulation pathways associated with monoterpene and paeoniflorin biosynthesis in P. lactiflora are still unclear. Here, we selected three genotypes of P. lactiflora with distinct morphologic features and chemical compositions that were a result of long-term reproductive isolation. We performed an RNA-sequencing experiment to profile the transcriptome changes of the shoots and roots. Using de novo assembly analysis, we identified 36,264 unigenes, including 521 genes responsible for encoding transcription factors. We also identified 28,925 unigenes that were differentially expressed in different organs and/or genotypes. Pathway enrichment analysis showed that the P. lactiflora unigenes were significantly overrepresented in several secondary metabolite biosynthesis pathways. We identified and profiled 33 genes responsible for encoding the enzymescontrolling the major catalytic reactions in the terpenoid backbone and in monoterpenoid biosynthesis. Our study identified the candidate genes in the terpenoid biosynthesis pathways, providing useful information for metabolic engineering of P. lactiflora intended for pharmaceutical uses and facilitating the development of strategies to improve marker-assist P. lactiflora in the future.
Retrofitting a Vedic Origin for a Classical Hindu Goddess
Authors: Lubin Timothy
Published: April 2020

Many Hindu deities as known from classical sources (i.e, from the epics, Purāṇas, and later religious literature and iconography) have a very slender profile in the Vedic texts, appearing in only a few passages and often represented in ways that seem peripheral to their full, classical personae. Ritualists and devotees steeped in that older literature took pains to connect those deities to Vedic mantras and rites, in order to validate them with the prestige of venerable orthodoxy as well as to provide a basis for Brahmin priestly roles in their worship. The case of the goddess Durgā is particularly striking in this respect, since her Vedic “footprint” is so small. This study carefully examines the Durgā Sūkta and related materials to show how Taittirīya and Ṛgveda Brahmins went about supplying a Vedic liturgy for Durgā worship. This account complements the one recently proposed to show how Atharvan priests in the service of rulers drew on Atharvavedic traditions to present Durgā as a patron goddess of arms and military strength.
Spatial Distribution of Phytoplankton in Jatigede Reservoir, West Java, Indonesia
Authors: Haifa Rima Nabilah , Hasan Zahidah , Herawati Heti , Nurruhwati Isni , Sahidin Asep
Published: April 2020

Jatigede Reservoir has water input from the Cimanuk River. This river has gone through several anthropogenic activities that can affect its waters. Changes in conditions can occur due to changes in ecosystems carried out by several ecological aspects, one of which is the distribution of biota structures. The purpose of this study is to map the distribution of phytoplankton through spatial distribution both horizontally and vertically at the Jatigede Reservoir, West Java. The study began in July 2019 until September 2019. This research uses survey method. Sampling was carried out at 4 stations on the surface, half of the compensation depth, and compensation depth. The water parameters analyzed are transparency, temperature, depth, current, pH, CO2, BOD, DO, NO3-, PO43-, NH3, fitoplankton abundance, diversity index and dominance index. The results showed that 49 genera from 11 classes and 5 phyla were identified. Diversity index during the study reached between 0.904-2.062 and the dominance index was in the range of 0.267-0.681. The highest phytoplankton composition at each station and depth was found in the Bacillariophyceae class as much as 59.65% with an average abundance of 5523 ind/L.11 phytoplankton classes found during the study were identified at all observation stations, except in the eustigmatophyceae and mediophyceae classes.
Computation of Economic Feasibility of Brinjal and Palak Intercropping System
Authors: Kumar Sangeet , Dhankhar S. K. , Chauhan Ajay , Kumar Rajesh , Kumar Sunil
Published: April 2020

Aim/Objective: To evaluate the economic feasibility of brinjal–palak intercropping system.

Study Design: Randomized Block Design.

Place and Duration of Study: Research Farm of the Department of Vegetable Science, CCS Haryana Agricultural University, Hisar during 2016-17.

Methodology: Experiment comprised of 11 treatments with three replications of palak (20 x 5 cm) as intercrop with brinjal (60 x 60 cm) and paired row brinjal (30/60 x 60 cm).

Results and Discussion: Brinjal + palak (single row) gave the highest production efficiency (532.3 kg/days), net returns (Rs. 222652) and benefit to cost ratio (3.76) due to low cost of production, closely followed by paired row brinjal + palak (two rows). Paired row brinjal + palak (two rows) intercropping system also exhibited maximum gross returns (Rs. 304598), monetary advantage index (MAI) (Rs.139055), replacement value of intercropping (RVI) (2.47), relative value total (RVT) (3.79) and relative net return (RNR) (2.71). This may be attributed to additional advantage of intercrop yield and higher economic value of intercropping.

Conclusion: From farmer’s point of view, the treatment paired row brinjal + palak (two rows) was considered to be the most remunerative one among all the respective treatments due to its higher MAI, RVI and RNR.
Comparison between Immunochromatographic Test and Enzyme Linked Immunosorbent Assay in Diagnosis of Helicobacter pylori Infection among Gastritis Patients in Khartoum State-Sudan
Authors: Elgasim Omer Abu , Elmukashfi Salman Taha Ahmed , Mohammed Rayan Abdelwahid , Faroug Adil Elamin
Published: April 2020

Background: The gold standard for the diagnosis of Helicobacter pylori infection requires an endoscopic biopsy of gastric mucosa for histological examination, urease test and culture; however serological tests are useful as a screening test for Helicobacter pylori infection.

Objective: To compare between Immunochromatographic Test and Enzyme Linked Immunosorbent Assay techniques in detection of Helicobacter pylori immunoglobulin gamma antibodies in serum of patients suffer from gastritis.

Materials and Methods: 245 patients were screened for Helicobacter pylori infections by rapid urease test. Sera from these patients were tested for anti- Helicobacter pylori immunoglobulin gamma antibodies by Enzyme Linked Immunosorbent Assay and Immunochromatographic Test techniques.

Results: Of 245 patients tested, Immunochromatographic Test positive/negative 114 (46.5%)/131 (53.5%), whereas Enzyme Linked Immunosorbent Assay positive/negative were 124 (50.6%)/121 (49.4%). Sensitivity/ specificity was 67.4%/74.5% and 90.2%/89.3% for Immunochromatographic Test/Enzyme Linked Immunosorbent Assay positive/negative, respectively. The diagnostic accuracy was 71%/89.7% for Immunochromatographic Test/Enzyme Linked Immunosorbent Assay, respectively.

Conclusion: The Enzyme Linked Immunosorbent Assay technique was found to be more sensitive, specific and accurate compared to the Immunochromatographic Test while The Immunochromatographic Test is commercially available, inexpensive and easy to perform compared to the Enzyme Linked Immunosorbent Assay.
The Impact of Economic Freedom on Creating Happiness and Inequality: International Evidences
Authors: Roka Debraj
Published: April 2020

It is remaining a big question in happiness economics, what is the common motto of human beings? What human beings want to achieve? Are these, money, good job, position, power, peace, good living condition, good health, good family, good environment and what others? All researchers from different disciplines are investigating to solve this economic problem and Most of the researchers agreed that happiness is the common aim of everyone in the world. The paper entitled “Does Economic Freedom Create Happiness or Inequality?” is estimated the effect of economic freedom on happiness by using other control variables like Gross Domestic Product growth, per capita and inequality. The paper analyzed the panel data covering 120 countries from 2008 to 2016. The fixed and random effect, the Generalized Least Squares, First in Difference and Linear Dynamic Panel Data/generalized method of moments estimation method are applied as the econometric strategies in this paper. The results found that the statistically significant and strong linear positive association between economic freedom and happiness in overall sampled countries and also found the positive linear association between income with happiness and a negative association between economic freedom and inequality and inequality and happiness.
pH induced changes in optical activity of guanine nucleosides
Authors: Guschlbauer Wilhelm , Courtois Yves
Published: July 2002

Optical rotatory dispersion and circular dichroism have been used to investigate the protonation of guanosine and some of its analogues. An inversion of the principal Cotton effect and the dichroic band is observed below the acid pK. It is suggested that a conformational change from the anti form above the pK to the syn form below the pK occurs. The reasons why this change should occur only in guanosine and not in adenosine are discussed.
Sur l'incorporation de la radioactivite du sn‐glycerol‐3‐phosphate‐14C dans le monogalactosyldiglyceride des plastes isoles
Authors: Douce R. , Guillot-Salomon T.
Published: July 2002

Isolated plastids (chloroplasts and etioplasts) that are morphogically intact and free of any contamination from other cell structures can incorporate label from sn‐glycerol‐3‐phosphate‐14C into monogalactosyldiglyceride.
Octamer reconstitution from acid‐extracted chicken erythrocyte histones
Authors: Lindsey George G. , Thompson Patricia , Pretorius Linda , Purves Langley R. , von Holt Claus
Published: July 2002

Histone octamers have been reconstituted from acid‐extracted chicken erythrocyte histones. By the criteria of molecular size on exclusion chromatography as well as sedimentation velocity and conformational properties established by circular dichroism, fluorescence spectroscopy and imido‐ester cross‐linking, the reconstituted octamers have a structure identical to that of salt‐extracted octamers.
Uptake of methionine sulfoximine by some N2 fixing bacteria, and its effect on ammonium transport
Authors: Kleiner Diethelm , Alef kassem , Hartmann Anton
Published: July 2002

The N2 fixing bacteria Klebsiella pneumoniae, Azospirillum brasilense, Rhodopseudomonas sphaeroides and Rhodospirillum rubrum, but not Azotobacter vinelandii accumulate the glutamine analogue methionine sulfoximine in the cell. In the accumulating cells methionine sulfoximine inhibits ammonium transport. Accumulation and inhibition are prevented by glutamine.
Localization of the thiorphan‐sensitive endopeptidase, termed enkephalinase A, on glial cells
Authors: Hans Lentzen , Palenker Jochen
Published: July 2002

Degradation of tritiated Leu‐enkephalin was studied in cultures of primary astrocytes from rat brain. The incubation experiments with a cell suspension revealed Tyr as the main tritiated metabolite; however, Tyr—Gly—Gly and Tyr—Gly were detectable as well. Using a crude membrane prepartion of the astrocytes, we found about equal amount of Tyr and Tyr—Gly—Gly but only trace quantities of Tyr—Gly. The production of Tyr was completely inhibited by bestatin, an inhibitor of aminopeptidases, that of Tyr—Gly—Gly by thiorphan, a specific inhibitor of enkephalinase A. The results prove the ability of glial cells to degrade enkephalin by aminopeptidase and a membrane‐bound enkephalinase A.
Conformational changes in arginine kinase upon ligand binding seen by small‐angle X‐ray scattering
Authors: Dumas Christian , Janin Joël
Published: July 2002

Small‐angle X‐ray scattering is used to study the effects of substrate binding to lobster arginine kinase in solution. We measure the radius of gyration of the enzyme in the absence and in the presence of ligands. We find that the radius of gyration decreases by 1.20 ± 0.25 Å upon binding ADP‐Mg and L‐arginine to form the ternary complex. The same decrease is also observed upon binding ADP‐Mg alone or ATP‐Mg. These results indicate a large conformational change consistent with the hinge motion of domains observed in other phosphokinases.
Adenylate cyclase in cilia from Paramecium
Authors: Schultz Joachim E. , Klumpp Susanne
Published: July 2002

A particulate adenylate cyclase was identified in the excitable ciliary membrane from Paramecium tetraurelia. MnATP was preferentially used as substrate, the K
m was 67 μM, V
max was 1 nmol cAMP.min−1.mg−1, a marked temperature optimum of 37°C was observed. Adenylate cyclase was not inhibited by 100 μM EGTA or 100 μM La3+, whereas under these conditions guanylate cyclase activity was abolished. Fractionation of ciliary membrane vesicles by a Percoll density gradient yielded two vesicle populations with adenylate cyclase activity. In contrast, calmodulin/Ca‐dependent guanylate cyclase was associated with vesicles of high buoyant density only.
Actinomycin D‐binding in vivo: active chromatin preferred
Authors: Yu Fu-Li
Published: July 2002

Escherichia coli RNA polymerase and the endogenous engaged RNA polymerase I were used as specific probes to monitor the physiologically inactive and active nucleolar chromatin template function, respectively. Actinomycin D bound preferentially to the physiologically active regions of rat liver nucleolar chromatin in vivo.
Parathyroid hormone secretion in the absence of extracellular free Ca2+ and transmembrane Ca2+ influx
Authors: Wallace Jean , Pintado Elizabeth , Scarpa Antonio
Published: July 2002

The involvement of extracellular Ca2+ and Ca2+ influx across the plasma membrane in parathyroid hormone (PTH) secretion was investigated in vitro using a new preparation of bovine parathyroid cells. Incubation of these cells in the presence of 25 μM or 2.5 μM free ambient Ca2+ induced a maximal rate of PTH secretion. Low free Ca2+ secretion is not associated with changes in membrane permeability, requires metabolic energy, and is reversible. The Ca2+ channel blocker D600 had no effect on either 45Ca‐influx or PTH secretion in these cells. These results, showing that extracellular Ca2+ and Ca2+ influx across the plasma membrane are not required for PTH secretion by parathyroid cells, emphasize the differences in the cellular mechanisms underlying the secretion of PTH vs that of other secretory cells.
Glutamine synthetase from the plant fraction of Phaseolus root nodules
Authors: Cullimore Julie V. , Miflin B.J.
Published: July 2002

Antiserum raised to glutamine synthetase (GS) from the plant fraction of Phaseolus vulgaris root nodules was used to immunoprecipitate in vitro translation products of nodule and root poly(A)+ RNA. The results showed that the large increase in GS activity which occurs during nodulation is due to an increased supply of GS mRNA. A 3‐fold enrichment of GS mRNA was obtained by centrifugation of total nodule poly. (A)+ RNA on dimethylsulphoxide‐formamide‐containing sucrose density gradients and purification to near homogeneity was achieved by immunopurification of nodule polysomes.
The complete amino acid sequence of the α‐amylase inhibitor I‐2 from seeds of ragi (Indian finger millet, Eleusine coracana Gaertn.)
Authors: Campos F.A.P. , Richardson M.
Published: July 2002

The complete amino acid sequence of the α‐amylase inhibitor I‐2 from ragi seeds was determined by analysis of peptides derived from the protein by digestion with trypsin, chymotrypsin thermolysin and S. aureus V8 protease. The protein consists of a single polypeptide chain of 95 amino acids, with a high content of serine and alanine, and no methionine, phenylalanine, histidine or tryptophan. There is no sequence homology with the bifunctional α‐amylase/trypsin inhibitor in the same seeds or with any of the α‐amylase inhibitors from other plants. The sequence contains two regions of weakly repetitive internal homology. The predicted secondary structure of the inhibitor is notable for the absence of α‐helix and its high content (50%) of β‐turn.
Requirement of protein synthesis for the coupling of histone mRNA levels and DNA replication
Authors: Helms Sherron , Baumbach Lisa , Stein Gary , Stein Janet
Published: July 2002

H1 and core histone mRNA levels have been examined in the presence of portein synthesis inhibitors with different mechanisms of action. Total HeLa cell RNAs were analyzed by Northern Blot hybridization using cloned human histone genes as probes. Inhibition of DNA replication resulted in a rapid decline in histone mRNA levels. However, in the presence of cycloheximide or puromycin, H1 and core mRNAs did not decrease in parallel with DNA synthesis, but were stabilized and accumulated. Inhibition of DNA synthesis with hydroxyurea after the inhibition of protein synthesis did not lead to a decline in histone mRNA levels. These results suggest that synthesis of a protein(s) ‐ perhaps a histone protein(s) ‐ is required for the coordination of DNA synthesis and histone mRNA levels.
Changes in intracellular pH and inorganic phosphate concentration during and after muscle contraction as studied by time‐resolved 31P‐NMR
Authors: Tanokura Masaru , Kazuhiro Yamada
Published: July 2002

The changes in intracellular pH and concentration of inorganic phosphate (Pi) were studied during and after contraction of bullfrog sartorius muscles by using 31P‐NMR. The intracellular pH was 7.04 in resting muscles at 4°C and an alkalinization by as much as 0.08 pH unit occurred following 5 s tetanic contraction. During the recovery period after contraction the increased level of intracellular pH returned to the resting level, the time course of which coincided with that of the recovery of the Pi concentration. Based on the changes in the intracellular pH and Pi concentration, the buffering power as estimated to be 18 mM/pH unit.
A manganese‐chloride cluster as the functional centre of the O2 evolving enzyme in photosynthetic systems
Authors: Critchley Christa , Sargeson Alan M.
Published: July 2002

Photosynthetic O2 evolution
O2 evolving complex mechanism
Manganese
Chloride
Metal cluster
The molecular mechanism of interaction of Et3Pb+ with tubulin
Authors: Faulstich H. , Stournaras C. , Doenges K.H. , Zimmermann H.-P.
Published: July 2002

Triethyllead ion (Et3Pb+) was found to interact with 2 out of 18 thiol groups present in tubulin dimers. Specificity of the interaction was shown by the high affinity of Et3Pb+ to tubulin, by the fact that the 16 residual thiol groups in tubulin remained unaffected, and by the observation that other proteins with exposed thiol groups, e.g., actin, did not react with Et3Pb+. After complexation of the two thiol groups, tubulin in vitro had lost its capability for microtubule assembly. Likewise, polymerized tubulin disassembled on addition of the lead compound.
Specific inhibition of mitochondrial protein synthesis influences the amount of complex I in mitochondria of rat liver and Neurospora crassa directly
Authors: van den Bogert C. , Holtrop M. , de Vries H. , Kroon A.M.
Published: July 2002

Specific inhibition of mitochondrial protein synthesis reduces the oxidation rate of NADH‐linked substrates in rat liver as well as in Neurospora crassa mitochondria. The present study shows that this is due to the fact that inhibition of mitochondrial protein synthesis leads to a decrease of the concentration of active complex I. Therefore, these results demonstrate that at least one of the genes for the subunits of complex I is localized on mitochondrial DNA.
The primary structure of maize and tobacco 5 S rRNA
Authors: Barciszewska Mirosława Z. , Mashkova Tamara D. , Kisselev Lev.L. , Barciszewski Jan
Published: July 2002

5 S ribosomal RNA structures from Zea mays and tobacco have been determined with two independent methods. The sequence of corn and tobacco 5 S rRNAs are identical to those of the Gramineae and the Solanaceae, respectively. There is no general structure conservation of 5 S rRNA in higher plants.
A fluorescence decay time study of tryptophan in isolated hemoglobin subunits
Authors: Albani Jihad , Alpert Bernard , Krajcarski Donald T. , Szabo Arthur G.
Published: July 2002

The time‐resolved fluorescence behavior of tryptophan residues in isolated human hemoglobin subunits was determined using a sync‐pumped dye laser system and time‐correlated single photon counting detection. Two decay components having values near 80 ps and 2 ns were found in the fluorescence decay of the α‐subunit. The data for the β‐chains were best fitted with 3 decay components of 90 ps, 2.5 ns and 6.4 ns. We propose that the decay times correspond to conformations of the proteins in which the disposition of the tryptophan to the heme residue differs.
A complete cDNA coding for the sequence of glycinin A2B1a subunit precursor
Authors: Momma Takayuki , Negoro Takaharu , Udaka Kyoko , Fukazawa Chikafusa
Published: July 2002

Analysis of the A2B1a subunit precursor, one of the A2‐subunit family of glycinin, the main storage protein of soybean, revealed that it is composed of a signal peptide segment (18 amino acids), the A2 acidic polypeptide (282 amino acids), followed by the B1a basic polypeptide (185 amino acids). There was overall 63% homology between this subunit complex and pea legumin, which is an analogous protein to glycinin. As this degree of homology is rather higher than that in the A3B4 subunit, one of the A3 subunit family, it seems that the genes encoding the A2 subunit family are phylogenetically more strongly related to the legumin genes.
β‐Endorphin and ACTH related peptides in primary cultures of rat anterior pituitary cells: evidence for different intracellular pools
Authors: Ham J. , Smyth D.G.
Published: July 2002

β‐Endorphin
ACTH
Pituitary cell culture
Processing
CRF
Epinephrine
Purification and characterization of ribosomal proteins from the 30 S subunit of the extreme halophile Halobacterium marismortui
Authors: Shoham M. , Dijḱ J. , Reinhardt R. , Wittmann-Liebold B.
Published: July 2002

Ribosomal proteins were extracted from 30 S subunits of Halobacterium marismortui under native conditions. Their separation was based on gel filtration and hydrophobic chromatography, performed at a concentration of 3.2 M KCl to avoid denaturation. A total of nine proteins were isolated, purified and identified by partial amino‐terminal sequences and two‐dimensional gel electrophoresis. There is a high degree of sequence homology with 30 S proteins from H. cutirubrum, and also some with 30 S proteins of eubacteria. Proton NMR data indicate unfolding of the proteins in low salt. One of the proteins, however, retains its secondary structure at a salt concentration as low as 0.1 M NaCl, and even in 8 M urea. One reason for this outstanding stability could be the high proportion (50%) of β‐structure in this protein as determined from circular dichroism measurements. In general, there is a higher β‐sheet content than for 30 S proteins from Escherichia coli. Measurements of Stokes radii indicate several of the proteins to have a rather elongated shape. One of these is a complex consisting of L3/L4 and L20, similar to the L8‐complex from E. coli. The presence of this 50 S complex in the preparation of the small subunit suggests a location on the interface between the subunits.
Purification and characterization of trimming glucosidase I from Saccharomyces cerevisiae
Authors: Bause Ernst , Erkens Rainer , Schweden Jürgen , Jaenicke Lothar
Published: July 2002

Glucosidase I was purified about 1900‐fold from yeast microsomal preparations by DEAE‐Sephacel chromatography, affinity chromatography on AH‐Sepharose 4B‐linked N‐5‐carboxypentyl‐1‐deoxynojirimycin and Con A‐Sepharose chromatography. The enzyme is a glycoprotein with a subunit molecular mass of 95 kDa. Its reaction has a pH optimum close to 6.8 and does not require metal ions. Purified glucosidase I hydrolyses the distal α1,2‐linked glucose residue from the Glc3‐Man9‐GlcNAc2 chain of its natural substrate, but is not active against Glc2‐Man9‐GlcNAc2 and aryl‐α‐glucosides. Like glucosidase I from calf liver, the yeast enzyme is strongly inhibited by 1‐deoxynojirimycin (dNM), N‐methyl‐dNM and N‐5‐carboxypentyl‐dNM with K
i values of 16, 0.3 and 3μM, respectively.
GTP dependence of the transduction of mitogenic signals through the T3 complex in T lymphocytes indicates the involvement of a G‐protein
Authors: Mustelin Tomas
Published: July 2002

The T3 molecule on the surface membrane of T lymphocytes is involved in the transduction of the proliferation signal generated by an interaction between the antigen receptor and an antigen, to the interior of the T cell. Mitogenic monoclonal antibodies against the T3 molecule and mitogenic lectins induce a rapid (within 5 min) protein synthesis‐independent activation of ornithine decarboxylase (ODC) in human T lymphocytes. When T cells are selectively depleted of guanine nucleotides by treatment with mycophenolic acid, the early mitogen‐induced activation of ODC is completely inhibited. The inhibition rapidly reverted on the addition of guanine a few minutes before the mitogenic stimulation, and even more rapidly by GTP directly introduced into the T cells by a transient membrane permeabilization. GTP can be substituted for by a non‐hydrolyzable GTP analogue, GTP‐γ‐S, which also induces ODC activity by itself in human T cells. These results suggest that a G‐protein(s) is involved in the transduction of the proliferation signal in human T cells.
Characterization of Phytomonas sp. kinetoplast DNA
Authors: Riou Jean-François , Dollet Michel , Ahomadegbe Jean-Charles , Coulaud Dominique , Riou Guy
Published: July 2002

Phytomonas sp. which belongs to the Trypanosomatidae family, is a pathogen of plants. Its kinetoplast DNA consists of a huge network of about 7000 catenated minicircles of 2880 ± 30 base pairs each. It represents 30–33% of the total cellular DNA. An AT composition of 65% has been evaluated from the buoyant density xxx = 1.694 . The restriction endonuclease HpaII was the only one able to cleave the minicircles into a single fragment. The other enzymes so far tested (EcoRI, HindIII, HaeIII, BamHI) do not cleave these minicircles significantly. Analysis of the kDNA by Southern blot hybridization shows that minicircles of Phytomonas sp. have little sequence homology with minicircles of other species of trypanosomes. Maxicircles, present in low proportions, have been identified. Our data indicate that the kinetoplast DNA of Phytomonas sp. presents biochemical characteristics which could be used to identify the Phytomonas genus.
Guanine nucleotides stimulate hydrolysis of phosphatidylinositol and polyphosphoinositides in permeabilized Swiss 3T3 cells
Authors: Taylor Colin W. , Blakeley Diane M. , Brown Kenneth D.
Published: July 2002

Hydrolysis‐resistant analogues of GTP specifically stimulate the formation of [3H]inositol mono‐, bis‐ and trisphosphates by saponin‐permeabilized Swiss 3T3 cells prelabelled with [3H]inositol. Each inositol phosphate is formed largely by hydrolysis of its parent lipid and not by dephosphorylation of inositol 1,4,5‐trisphosphate [(1,4,5)IP3]. Although hydrolysis of phosphatidylinositol 4,5‐bisphosphate (PIP2) is most sensitive to guanine nucleotides, hydrolysis of phosphatidylinositol (PI) and phosphatidylinositol 4‐phosphate (PIP) is quantitatively more important. These results suggest that a guanine nucleotide‐dependent regulatory protein(s) (G‐protein) is involved in regulating the hydrolysis of PI and PIP, as well as PIP2, and so may allow formation of diacylglycerol (DG) without simultaneous production of (1,4,5)IP3 and mobilization of intracellular Ca2+.
The structure of γ‐N‐methylasparagine in C‐phycocyanin from Mastigocladus laminosus and Agmenellum quadruplicatum
Authors: Duerring Markus , Huber Robert , Bode Wolfram
Published: July 2002

The crystal structures of C‐phycocyanin from Mastigocladus laminosus and Agmenellum quadruplicatum have been reinvestigated to accommodate the recently found γ‐N‐methylasparagine residue at β‐72. In both structures, position β‐72 could be modelled as γ‐N‐methylasparagine. The molecular phycocyanin structures were corrected accordingly. Possible roles of γ‐N‐methylasparagine are discussed on the basis of the three‐dimensional structure.
The amino acid sequences of frog heart atrial natriuretic‐like peptide and mammalian ANF are closely related
Authors: Lazure C. , Ong H. , McNicoll N. , Netchitailo P. , Chrétien M. , De Léan A. , Vaudry H.
Published: July 2002

Despite few studies conducted in non‐mammalian species, there has been a number of reports pertaining to the occurrence of a natriuretic‐like substance in lower organisms. Thus, an immunoreactive substance reacting with antibodies directed against mammalian atrial natriuretic factor has previously been detected both in heart atria and ventricles of a chordate, the frog. This substance was isolated and purified from frog heart atria and its amino acid sequence established. The sequence, Ala‐Pro‐Arg‐Ser‐Ser‐Asp‐Cys‐Phe‐Gly‐Ser‐Arg‐Ile‐Asp‐Arg‐Ile‐Gly‐Ala‐Gln‐Ser‐Gly‐Met‐Gly‐Cys‐Gly‐Arg‐(Phe), is highly homologous to known mammalian ANF sequences. However, when aligned with the complete mammalian ANF precursor sequence at positions 121 to 151, it exhibits a single amino acid insertion at position 129 and other substitutions at positions 121, 125, 133 ,135, 144, 147 and 148. Some evidence is also presented concerning the occurrence of uncleaved frog pronatriodilatin, the precursor form of ANF. This study represents the first report pertaining to the structure of a non‐mammalian ANF and its precursor.
Calcium ions induce glutamate transport into rat brain membrane vesicles in the absence of sodium and chloride evidence for a novel uptake site?
Authors: Hollmann M. , Harnecker J. , Seifert W.
Published: July 2002

Evidence is presented that glutamate binding to rat brain synaptic plasma membranes measured in Cl−‐ and Na+‐free but Ca2+‐supplemented buffers is partly due to uptake of glutamate into resealed membrane vesicles. An intravesicular volume of 7.9 μl/mg protein was measured. Ca2+‐induced glutamate binding to synaptic plasma membranes was found to be sensitive to low temperatures as well as to an increase in osmolarity and was abolished by short pulses of ultrasonication. None of several glutamate receptor agonists tested discriminated between basal and Ca2+‐induced binding but 4 out of 5 glutamate uptake inhibitors did. The Ca2+‐induced increase in glutamate binding was the same irrespective of whether calcium acetate, calcium sulfate or calcium gluconate in either Tris‐acetate of Tris‐citrate buffer was used.