bluuebunny/crossref_metadata_2025 huggingface dataset:
Strategia cercetării științifice: evidențe din Republica Moldova
Authors:   Information Society Development Institute, Republic of Moldova, Cuciureanu Gheorghe , Cojocaru Igor ,   Information Society Development Institute, Republic of Moldova, Minciuna Vitalie ,   Information Society Development Institute, Republic of Moldova, Turcan Nelly ,   Information Society Development Institute, Republic of Moldova
Published: January 2023

Scientific research can play an essential role in finding solutions to societal challenges, given that the research-development system is properly organised, which is only possible by knowing the regularities of how science works and the real state of the system. Policies developed in the absence of data and results of scientific studies are superficial and lack consistency. For a research-development strategy in the Republic of Moldova to fit into a coherent, systemic and predictable policy, it should clearly stipulate a vision for scientific research, what kind of science will be developed, what objectives will be pursued and what mechanisms will be used to achieve them.
Mineral water as food for bone: an overview
Authors: Pampaloni Barbara , Brandi Maria Luisa
Published: January 2023

Water is a primary asset and contributes significantly to human health. Although water requirements vary from person to person, an intake of 1.5-2 L per day is known to guarantee proper hydration, and is essential to maintaining the body’s water balance. Water for human use includes “water” (treated or not) intended to be drinkable, used for the preparation of food and drinks, and for other domestic uses, and “natural mineral water”, meaning waters that “originate from an aquifer or from a groundwater basin, which flow from one or more natural or reamed (perforated) springs and which have specific hygienic characteristics and, possibly, health properties”. According to European legislation (Directive 2009/54/EC), mineral waters can be classified on the basis of analysis of their main chemical-physical characteristics. Natural mineral waters can also be classified into many categories on the basis of their mineral composition and principal component. Natural mineral waters are known to have many beneficial (and non-beneficial) effects on human health and several studies have explored their properties and their role in different physiological and pathological conditions. Despite concerns about possible negative effects due to the plasticizers and/or endocrine disruptors that may be present in bottled mineral waters, their consumption is widespread. Calcium-rich mineral waters (calcium content >150 mg/L) supply excellent amounts of highly bioavailable calcium and are a very useful way of taking in calcium regularly and in a well distributed way throughout the day, without experiencing side effects; they therefore contribute to the achievement of the recommended intakes. Mineral waters can also be used as supplements to reduce the risk of deficiency of other micronutrients important for bone health such as boron, strontium and fluoride. Finally, gut microbiota is emerging as a key player in bone turnover regulation due to its ability to modulate the immune system, controlling inflammation and also influencing calcium absorption and vitamin D levels. Intestinal dysbiosis may promote bone mass loss in older people and after menopause. For this reason, the maintenance of a healthy and efficient intestinal microbiota is considered fundamental in the management of skeletal pathologies, both to prevent them and to support possible drug therapies.
Does Urinary Vitamin D-Binding Protein Have a Role in the Prediction of Steroid Resistance in Nephrotic Syndrome? A Cohort Study on Egyptian Children
Authors: Salah Doaa M , Aoun Ahmed H , Fahmy Balsam Sherif , Abu Zeid Asmaa Hasan Mahaseb , Fahmy Yosra Aboelnaga
Published: January 2023

Background: Nephrotic syndrome (NS) is a common glomerular disease in children, for which there are currently no noninvasive markers for predicting responsiveness to steroid treatment. Objectives: This study aimed to analyze the relationship between clinical-laboratory presentations and subsequent response to steroid therapy and to evaluate the role of urinary vitamin D binding protein (uVDBP) as a predictor of steroid resistance (SR). Methods: This was a prospective longitudinal study on 60 children with active NS (30 patients with newly diagnosed NS and 30 with relapsed NS). In addition, 30 control subjects served as a reference group for uVDBP values. The patients were evaluated before starting steroid therapy, and response to steroid therapy was monitored 4 - 8 weeks later. Results: The levels of uVDBP were elevated in patients with NS (33.33 ± 15.6 ng/mL) compared to control subjects (17.35 ± 5.5 ng/mL, P < 0.001). Also, the levels of uVDBP were significantly higher in patients with relapsed NS (37.93 ± 16.2 ng/mL) than in newly diagnosed NS patients (28.73 ± 13.67 ng/mL, P = 0.014). The level of uVDBP on presentation did not significantly differ between patients who had steroid-sensitive nephrotic syndrome (SSNS) (34.91 ± 15.01 ng/mL) and patients who had steroid-resistant nephrotic syndrome (SRNS) after 4 - 8 weeks of steroid treatment (32.60 ± 15.94 ng/mL, P = 0.417). Steroid resistance was significantly associated with a younger age of onset, specifically below 2.1 years (P = 0.023), a longer duration of the illness (P = 0.007), having more relapses (P = 0.002), total leucocytic count on presentation > 8.05 × 103/mm3 (P = 0.031), and platelet counts on presentation > 516.5 × 103/mm3 (P = 0.044). Conclusions: In this study, we found that uVDBP levels could reflect disease severity rather than predict the pattern of steroid responsiveness. Younger age of onset, longer duration of illness, previous relapses, and increased total leukocyte and platelet counts on presentation were associated with SRNS.
Migration, Labor, and Welfare
Authors: Küppers Arnd ,   Philosophy Documentation Center
Published: January 2023

The desire for work, income, and better living conditions is the main cause for international migration. Such labor migration is also called economic migration, although it has many non-economic aspects and side effects as well. This article seeks to examine the reasons for and the consequences of international labor migration in its different dimensions. This will take into consideration the interests of all three groups involved: the migrants and their families, the countries of origin and their peoples, the host countries, and the local populations. The core of the article is a social ethical evaluation of the conflicts of interest revealed in the analysis, considering the values of human dignity and justice. The aim is to explore how to balance different interests through a humane and fair immigration policy and international migration partnership.
Back-to-Back Comparison of Third-Generation Sequencing and Next-Generation Sequencing in Carrier Screening of Thalassemia
Authors: Huang Renliang , Liu Yinyin , Xu Jing , Lin Dan , Mao Aiping , Yang Liuqing , Zhong Gaobu , Wang Huoniao , Xu Ruofan , Chen Yiwei , Zhou Qiaomiao
Published: January 2023

Context.—

Recently, new technologies, such as next-generation sequencing and third-generation sequencing, have been used in carrier screening of thalassemia. However, there is no direct comparison between the 2 methods in carrier screening of thalassemia.

Objective.—

To compare the clinical performance of third-generation sequencing with next-generation sequencing in carrier screening of thalassemia.

Design.—

Next-generation sequencing and third-generation sequencing were simultaneously conducted for 1122 individuals in Hainan Province.

Results.—

Among 1122 genetic results, 1105 (98.48%) were concordant and 17 (1.52%) were discordant between the 2 methods. Among the 17 discordant results, 4 were common thalassemia variants, 9 were rare thalassemia variants, and 4 were variations with unknown pathogenicity. Sanger sequencing and polymerase chain reaction for discordant samples confirmed all the results of third-generation sequencing. Among the 685 individuals with common and rare thalassemia variants detected by third-generation sequencing, 512 (74.74%) were carriers of α-thalassemia, 110 (16.06%) were carriers of β-thalassemia, and 63 (9.20%) had coinheritance of α-thalassemia and β-thalassemia. Three thalassemia variants were reported for the first time in Hainan Province, including –THAI, -α2.4, and ααααanti3.7. Eleven variants with potential pathogenicity were identified in 36 patients with positive hemoglobin test results. Among 52 individuals with negative hemoglobin test results, 17 were identified with thalassemia variants. In total, third-generation sequencing and next-generation sequencing correctly detected 763 and 746 individuals with variants, respectively. Third-generation sequencing yielded a 2.28% (17 of 746) increment compared with next-generation sequencing.

Conclusions.—

Third-generation sequencing was demonstrated to be a more accurate and reliable approach in carrier screening of thalassemia compared with next-generation sequencing.
Privacy of Staff Biometric Data in Vulnerable Population Outreach
Authors: Barbakoff Audrey , Kuver Rekha , Anderson Christine
Published: January 2023

In restoring Outreach services following COVID-19, Mobile Servcies staff at King County Library System (KCLS) have encountered a growing concern for staff data privacy. A significant number of facilities have begun replacing paper sign-in logs with automated kiosks that record, store, and share a large amount of staff personal, medical, and biometric data. This article provides an example that demonstrates the widespread implications for outreach staff data privacy, and explores broader considerations related to this trend. It shares principles that may assist other libraries in developing guidelines for staff data privacy during outreach visits.
Confronting the Intersection of COVID-19 and Privacy
Authors: Joe Jennifer
Published: January 2023

When I first proposed this special issue in the spring of 2021, I had hoped the resulting articles would be a retrospective—looking back at how we had met the challenge of COVID-19, conquered it, and taken the lessons that it gave us into the future. Writing this editorial now, it is clear that is not what has happened. COVID-19 and its variants of concern, most recently BQ.1, continue to wreak havoc on our public institutions. This is, of course, most notably felt in the healthcare system, but all public services must grapple with balancing serving their customers with ensuring the safety of their employees—and the privacy of both.
Des cristaux d’Auguste Laurent et des techniques d’analyse optique de Jean-Baptiste Biot furent directement à l’origine de la découverte de la chiralité par Louis Pasteur / The crystals of Auguste Laurent and the optical analysis techniques of Jean-Baptiste Biot were directly responsible for the discovery of chirality by Louis Pasteur
Authors: This vo Kientza Hervé
Published: January 2023

The history of Louis Pasteur's separation of two kinds of tartaric acids is complicated, because (1) the names of the compounds discussed changed over time, (2) the notions of molecule and atom in the 19th century were not those we have today, (3) the historical texts are numerous and sometimes contradictory, as will be seen here by selected examples, and (4) many of the commentaries on Pasteur's work have been hagiographic or nationalistic, as early as Pasteur's lifetime. In particular, this article establishes that, contrary to popular belief, the separation of the two types of tartrate crystals present in the racemic mixture did not require particularly remarkable skill or vision, as has been stated; instead, Pasteur must have learned the techniques of crystallization, in order to form the crystals (which were several centimeters long) he was exploring by then- modern optical analysis techniques. Pasteur must above all be credited with persistence in his studies of this question, and his work is part of the long history of tartaric acid and tartrates during which Jean-Baptiste Biot and Auguste Laurent, in particular, played a primordial role, often underestimated. Finally, the recognition of the various tartaric acids and tartrates is neither the beginning nor the end of the history of chirality.
Individualized Approach to Management of Light Chain Amyloidosis
Authors: Palladini Giovanni , Milani Paolo
Published: January 2023

Systemic light chain (AL) amyloidosis is caused by a B-cell (most commonly plasma cell) clone that produces a toxic light chain that forms amyloid fibrils in tissues and causes severe, progressive organ dysfunction. The clinical presentation is protean, and patients are usually extremely frail, thus requiring careful adaptation of the treatment approach. However, the severity of organ involvement can be accurately assessed with biomarkers that allow a sharp prognostic stratification and precise tailoring of the treatment strategy. Moreover, the availability of biomarker-based response criteria also allows adjustment of the treatment approach over time. The recent completion of 3 large randomized clinical trials has offered new evidence for designing appropriate treatments. All this information has recently been integrated in the joint guidelines of the International Society of Amyloidosis and the European Hematology Association for the treatment of AL amyloidosis. Other clinical trials are underway testing new agents directed against the amyloid clone and the amyloid deposits. Our understanding of the peculiarities of the amyloid clone, as well as our ability to detect residual clonal disease and improve organ dysfunction, are also being refined and will result in more precise personalization of the treatment approach.
Narrative Cities - Literary Edinburgh. A Model to Follow
Authors: Erkoçi Ilda
Published: January 2023

While Edinburgh is a beautiful and interesting city to visit per se, its literature is an added value which plays a crucial role in marketing the capital city. The importance of literature in generating tourism has been highlighted by a number of studies. The opposite is true as well: tourism can also lead to literature. Edinburgh is probably one of the best examples in this respect. Many people go there to just visit the city but encounter literature in unexpected places. This paper is an autoethnographic account of a literary tour in Edinburgh. It looks at how this city makes use of its literary heritage and why it is a great model to follow. The author contends that while literary tourism is open to any book lover, still, some strategies are needed to promote literature and bring it to the attention of people in new and interesting ways. The success of Edinburgh as a literary city owes a lot to the interactive ways used by its authorities to showcase literature and keep people interested through direct and active engagement. The paper has been structured as a combination of experiential and analytic writing, with the former reflected through an evocative autoethnography and the latter as an analysis of that experience.
Religion and the modern education
Authors: Leka Agim
Published: January 2023

The purpose of the research is to solve the paradox of religion integration in education, by the new balance between religion, philosophy and science, during the post communism transition. In the field of thinking, the process is the transition from ideology to integral thinking. It is realized through the re-evaluation of the topics of the integration of religion, transitology and integral though, education, inclusiveness, solidarity, new laicity and new secularity. In the philosophical sense, integration is the objective process of being developed. This is understood as a return to identity towards a universal being. In the context of the social being, the process realizes the opening and cooperative development of all mental, spiritual-religious, scientific, creative-artistic, economic, cultural, material and non-material political fields. It includes the individual, the community, and all institutions of social life. The path of integration development is the transitive movement in a spiral form. In Albania, with the fall of communism, freedom of religion was legalized according to the standards of European democracy. The rehabilitation of religious figures that had been condemned and persecuted by the totalitarian regime began. The post-communist transition brought profound changes in the field of faith and religion such as the new dimension in the relationship of society with religion, new and unfamiliar attitudes of believers to religion, new relations between the state and religious institutions, new relations between education and religion in public institutions, opening of religious schools and increasing the influence of religion through the media and religious literature. What is considered tolerance in Europe, in the Albanian case is respect. Albanians are the best model for religious tolerance (respect). There has never been a religious clash in Albania for any reason. Respect for the religious affiliation and religious belief of the other in the Albanian case is modeled as the guiding value of their identity and appears in everyday life as the acceptance of the other. For this reason, they are the best model of respect and acceptance of the other, regardless of religious affiliation. This is an ontological value, built over the centuries and continues to this day. Albanians have not converted, but have adapted to a religious belief for economic and survival reasons. Marriages with different religions and keeping two names (Christian and Muslim) are natural phenomena among Albanians. In Albania, there are in the family and tribe people with Christian and Muslim religions individuals with two names, Christian and Muslim: Kristo and Muhamed. Albanians have lived in peaceful symbiosis with the Slavs in the centuries of the latter’s influx into Albanian lands. They have also lived peacefully with other neighbors, Greeks or Romans. This is even though the neighbors have not always been peaceful with the Albanians.
Impact of Work Experience on the Level of Awareness of Construction Workers on Using Personal Protective Equipment
Authors: Asis Celeste A. De , Licas Felix S. , Bulagao Jonathan C.
Published: January 2023

This study determined the level of awareness of the construction workers in the province of Northern Samar on using the personal protective equipment as well the relationship between the level of awareness and the length of construction experience and support of the company management on safety aspect of the construction workers.

The construction workers’ ages are of ranges from below 18 to above 60 years old.  Majority is of ages from 18 to 30 years old (46%), next is of ages 31 to 40 years of age (30%), then 41 to 50 years old (14%), then below 18 years old (9%) and last is of ages above 60 years old (1%). All respondents are male and mostly, are married (61%). Some are single (38%) and widow (1%). The construction workers experienced as foreman (9%), as Leadman (2%), skilled (31%), semi-skilled (16%) and mostly as Labor (42%).

By Spearman’s Rho correlation the relationship of the length of experience and so with the company’s safety management and the level of awareness on using PPE are determined. The identified variables are highly correlated with the level of awareness on using PPE. Based on the analysis, these construction workers are moderately aware on account of their work experiences.
Transcript levels of the nuclear‐encoded respiratory genes in rice decrease by oxygen deprivation: evidence for involvement of calcium in expression of the alternative oxidase 1a gene
Authors: Tsuji Hiroyuki , Nakazono Mikio , Saisho Daisuke , Tsutsumi Nobuhiro , Hirai Atsushi
Published: July 2002

We investigated the effect of oxygen on the expressions of respiratory genes encoded in the nuclear and mitochondrial genomes of rice (Oryza sativa L.). Hypoxic treatment decreased the transcript levels of nuclear‐encoded, but not mitochondrial‐encoded respiratory genes. The effects of ruthenium red (an inhibitor of Ca2+ fluxes from organelles) and/or CaCl2 on plants under hypoxic conditions suggested that Ca2+ is a physiological transducer of a low‐oxygen signaling pathway for expression of the alternative oxidase 1a gene (AOX1a), but not for expressions of genes involved in the cytochrome respiratory pathway, in rice.
Acceleration of oxidative folding of bovine pancreatic ribonuclease A by anion‐induced stabilization and formation of structured native‐like intermediates
Authors: Low Lawrence K , Shin Hang-Cheol , Narayan Mahesh , Wedemeyer William J , Scheraga Harold A
Published: July 2002

Phosphate anions accelerate the oxidative folding of reduced bovine pancreatic ribonuclease A with dithiothreitol at several temperatures and ionic strengths. The addition of 400 mM phosphate at pH 8.1 increased the regeneration rate of native protein 2.5‐fold at 15°C, 3.5‐fold at 25°C, and 20‐fold at 37°C, compared to the rate in the absence of phosphate. In addition, the effects of other ions on the oxidative folding of RNase A were examined. Fluoride was found to accelerate the formation of native protein under the same oxidizing conditions. In contrast, cations of high charge density or ions with low charge density appear to have an opposite effect on the folding of RNase A. The catalysis of oxidative folding results largely from an anion‐dependent stabilization and formation of tertiary structure in productive disulfide intermediates (des‐species). Phosphate and fluoride also accelerate the initial equilibration of unstructured disulfide ensembles, presumably due to non‐specific electrostatic and hydrogen bonding effects on the protein and solvent.
Cytotoxic potential of the phytochemical genistein isoflavone (4′,5′,7‐trihydroxyisoflavone) and certain environmental chemical compounds on testicular cells
Authors: Kumi‐Diaka James , Nguyen Vu , Butler Andre
Published: July 2002

Summry— The effects of genistein (Gn), sodium azide (naz), and dexamethasone (dxm) on testicular cells TM3, TM4 and GC‐1 spg were studied in vitro. First, a series of experiments were performed to assess the response of the cells to the exposure of Gn, naz, dxm, a combination of Gn with naz and Gn with dxm. Trypan blue exclusion assay was used to determine the percentage of viability, and LDH‐cytotoxicity test was used to assess the degree of treatment‐induced cytotoxicity on each cell type. A second series of experiments were performed to study cytomorphology and determine the type and percentage of treatment‐induced cell death (apoptosis and necrosis) on each cell line, using fluorescent dye technique to detect apoptotic and necrotic cells, and tunnel assay to confirm apoptosis. The results from the data obtained demonstrated: i) that incubation of testis cells with each of the agents (Gn, dxm, naz) alone and in two combinations (Gn‐dxm, and Gn‐naz) induced significant testicular cell death; ii) that both genistein and dexamethasone mostly and significantly induced apoptotic cell death while sodium azide induced necrotic cell death; iii) that addition of dexamethasone to genistein demonstrated synergism in apoptosis on testis cells; and iv) that combination of naz with Gn demonstrated synergism in necrosis on testis cells even though Gn alone did not induce significant necrosis. It is concluded that the synergistic actions of genistein and dxm, and of genistein + sodium azide in induction of apoptosis and/or necrosis may be of clinical and pathophysiological research interest considering the chemopreventive and chemotherapeutic potential of genistein; and the clinico‐pharmacological application of dexamethasone and sodium azide.
Use of At‐Line Spectrophotometry for the Rapid Definition of Pilot‐Scale Flocculation Processes
Authors: Bou‐Habib G. , Yeung K. , Titchener‐Hooker N. J. , Hoare M.
Published: July 2002

Traditionally most downstream bioprocesses have been operated without real‐time knowledge of product and key contaminants, yielding little confidence in their operation and the impact on subsequent operations. A rapid UV–vis spectral prediction technique has been successfully demonstrated for the at‐line characterization of a large scale continuous flocculation process in terms of RNA, key protein contaminants, and cell debris. A comparison was made between the spectral predictions and retrospective wet chemical assays, and a highly linear correlation was obtained. The spectral analysis technique allowed for real‐time system information, which was applied to control the flocculation process to maintain satisfactory process performance, even when subjected to given possible process disturbances.
Penicillin G Acylase‐Fatty Lipid Biocomposite Films Show Excellent Catalytic Activity and Long Term Stability/Reusability
Authors: Phadtare Sumant , Parekh Parag , Gole Anand , Patil Mrunal , Pundle Archana , Prabhune Asmita , Sastry Murali
Published: July 2002

The formation of biocomposite films of the pharmaceutically important enzyme penicillin G acylase (PGA) and fatty lipids under enzyme‐friendly conditions is described. The approach involves a simple beaker‐based diffusion protocol wherein the enzyme diffuses into the lipid film during immersion in the enzyme solution, thereby leading to the formation of a biocomposite film. The incorporation of the enzyme in both cationic as well as anionic lipids suggests the important role of secondary interactions such as hydrophobic and hydrogen bonding in the enzyme immobilization process. The kinetics of formation of the enzyme‐lipid biocomposites has been studied by quartz crystal microgravimentry (QCM) measurements. The stability of the enzyme in the lipid matrix was confirmed by Fourier transform infrared spectroscopy (FTIR) and biocatalytic activity measurements. Whereas the biological activity of the lipid‐immobilized enzyme was marginally higher than that of the free enzyme, the biocomposite film exhibited increased thermal/temporal stability. Particularly exciting was the observation that the biocomposite films could be reused in biocatalysis reactions without significant loss in activity, which indicates potentially exciting biomedical/industrial application of these films.
Kinetics of Pressure Inactivation at Subzero and Elevated Temperature of Lipoxygenase in Crude Green Bean (Phaseolus vulgaris L.) Extract
Authors: Indrawati  , Van Loey Ann M. , Ludikhuyze Linda R. , Hendrickx Marc E.
Published: July 2002

Lipoxygenase (LOX) in crude green bean extract was irreversibly inactivated by pressure treatments combined with subzero or elevated temperature. LOX inactivation was described accurately assuming a first‐order reaction. In the entire pressure‐temperature domain studied (200 to 700 MPa and −10 to 60 °C), an increase in pressure at constant temperature enhanced the LOX inactivation rate, whereas at constant pressure, an increase in reaction rate was obtained by either increasing or decreasing temperature at 20 °C. At elevated pressure, LOX exhibited the greatest stability around 20 °C. Also the pressure dependence of the inactivation rate constants for LOX was the highest around 20 °C. On the basis of the estimated LOX inactivation rate constants, an iso‐rate contour diagram as a function of pressure and temperature was constructed, and an empirical mathematical model describing the combined pressure‐temperature dependence of the LOX inactivation rate constants was formulated.
The effects of flooding and livestock on post‐dispersal seed predation in river red gum habitats
Authors: Meeson N. , Robertson A.I. , Jansen A.
Published: July 2002

Rates of seed predation are influenced by conditions that alter seed supply and the activity of seed predators. In southern Australia the potential seed supply for the dominant floodplain tree species, the river red gumEucalyptus camaldulensis, has been reduced through forest clearing to support grazing by introduced livestock. River regulation and water extraction have reduced the frequency of flooding and thus the conditions that promote seed germination on floodplains. To determine if poor recruitment of river red gums could be caused by low seed supply, as a result of post‐dispersal seed predation, we used field experiments and observations to investigate how post‐dispersal predation on seeds ofE. camaldulensiswas affected by flooding, livestock management and their interaction.

Seed predation was measured before and after different flood treatments (0·5 m depth; short flood of 24 h, long flood of 30 days). Flooding of this kind (return frequency of once per year) did not have any significant effect on rates of seed removal by seed predators.

Rates of seed predation in floodplain habitats under widespread livestock management regimes changed seasonally. In all seasons seed predation was lowest at sites grazed by sheep. In winter seed predation was highest at ungrazed sites. In spring and summer seed predation was highest at sites grazed by cattle. Ant communities differed between forested and cleared habitats and seed‐eating ant species were most abundant in cleared sites grazed by cattle.

Rates of seed predation in forested floodplain sites with different flood histories differed among sites with different livestock management histories. The impact of cattle exclusion on seed predation rates increased as the period since flooding increased.

Cattle grazing is widespread on the floodplains of rivers across the southern Murray‐Darling Basin, and tree densities and hence seed supplies are low. In this situation small floods may not result in significant recruitment to river red gum populations because seed predation may reduce seed supply before and following flooding. Decreases in the frequency of flooding owing to river regulation and water extraction are likely to have exacerbated the influence of livestock on seed supply and thus reduced potential recruitment even further.

Efforts to rehabilitate large floodplain rivers based solely on the return of more natural flow regimes may fail if the effects of factors such as livestock grazing are not managed concurrently.
Aetiology of leaf spot of garlic and onion caused by Stemphylium vesicarium in Spain
Authors: Basallote‐Ureba M. J. , Prados‐Ligero A. M. , Melero‐Vara J. M.
Published: July 2002

Surveys between 1989 and 1993 in the major garlic production areas of Spain identified a new leaf spot disease, characterized by white and purple lesions followed by extensive necrosis. Isolation and pathogenicity tests with fungal isolates taken from these spots indicated that Stemphylium vesicarium was the causal agent. Pseudothecia of the teleomorph stage, Pleospora sp., were found on leaf debris from affected plants. Inoculation of garlic and onion plants with residues carrying mature pseudothecia, or with ascospore suspensions obtained from the pseudothecia, resulted in the development of white and purple leaf spots. Wetness periods longer than 24 h were required for symptom development under controlled conditions. Isolates of S. vesicarium from garlic, onion and asparagus caused disease in all three hosts. In garlic, cv. Blanco de Vallelado was most susceptible, while lines B4P17 and B6P1, and cvs Iberose and Golourose were less susceptible to the disease.
Advantages and disadvantages of aggregating fluxes into synthetic and degradative fluxes when modelling metabolic pathways
Authors: de Atauri Pedro , Curto Raul , Puigjaner Joaquim , Cornish‐Bowden Athel , Cascante Marta
Published: July 2002

It is now widely accepted that mathematical models are needed to predict the behaviour of complex metabolic networks in the cell, in order to have a rational basis for planning metabolic engineering with biotechnological or therapeutical purposes. The great complexity of metabolic networks makes it crucial to simplify them for analysis, but without violating key principles of stoichiometry or thermodynamics. We show here, however, that models for branched complex systems are sometimes obtained that violate the stoichiometry of fluxes at branch points and as a result give unrealistic metabolite concentrations at the steady state. This problem is especially important when models are constructed with the S‐system form of biochemical systems theory. However, the same violation of stoichiometry can occur in metabolic control analysis if control coefficients are assumed to be constant when trying to predict the effects of large changes. We derive the appropriate matrix equations to analyse this type of problem systematically and to assess its extent in any given model.
Interfaces in GaAs/AlAs quantum well structures
Authors: Gammon D. , Shanabrook B. V. , Katzer D. S.
Published: July 2002

We present a study of the bottom interface (GaAs on AlAs) in GaAs/AlAs single quantum wells using reflection high-energy electron diffraction, luminescence, and luminescence excitation spectroscopy. The results indicate that it is possible to grow GaAs/AlAs quantum wells with two truly smooth interfaces using molecular beam epitaxy with growth interrupts. A set of samples in which the growth interrupt time on the bottom interface was changed illustrates in a systematic way the qualitative behavior possible in luminescence spectra. In particular, the energy splitting between the exciton peaks is observed to vary in the rough regime and in the truly smooth regime, although in a different way.
Periodic index separate confinement heterostructure InGaAs/AlGaAs multiple quantum well laser grown by organometallic vapor phase epitaxy
Authors: Hobson W. S. , Wu M. C. , Chen Y. K. , Chin M. A. , Geva M. , Jones K. S.
Published: July 2002

Organometallic vapor phase epitaxy was used to grow a novel periodic index separate confinement heterostructure (PINSCH) InGaAs/AlGaAs multiple quantum well (MQW) laser. Secondary ion mass spectrometry and transmission electron microscopy were used to characterize the structure. The performance of the PINSCH laser was compared with that of a graded index separate confinement heterostructure (GRINSCH) MQW laser grown under similar conditions. The PINSCH laser uses cladding layers comprised of periodic semiconductor multilayers (Al0.4Ga0.6As/GaAs) which provide both optical and electrical confinement. Since the optical field decays over several multilayers, and therefore is far less tightly confined than in the GRINSCH structure, a significant reduction of the transverse far-field angle occurs. Comparing the performance of 5×750 μm self-aligned ridge waveguide InGaAs/AlGaAs lasers emitting at 980 nm, the PINSCH structure exhibits a transverse far-field angle of 23° compared to 46° for the GRINSCH. This is obtained at the expense of a modest increase in threshold current (19 mA vs 10 mA).
Preparation of ferroelectric BaTiO3 thin films on polycrystalline BaPbO3 substrates by sol-gel processing and their electrical properties
Authors: Kuwabara M. , Takahashi S. , Kuroda T.
Published: July 2002

Barium titanate thin films were deposited on metallic conducting BaPbO3 ceramic substrates by the sol-gel method using metal alkoxides. The thin films with a thickness of around 0.4 μm were confirmed to have a perovskite structure and to be highly resistive with a resistivity of more than 1011 Ω cm at room temperature. The typical dielectric constant and dissipation factor of the films were 600 and less than 2% (1 kHz), respectively, at room temperature. From ferroelectric hysteresis measurements a remnant polarization of around 1.5 μC/cm2 and a coercive field of about 28 kV/cm were obtained for the films.
High-mobility p-channel metal-oxide-semiconductor field-effect transistor on strained Si
Authors: Nayak D. K. , Woo J. C. S. , Park J. S. , Wang K. L. , MacWilliams K. P.
Published: July 2002

An enhancement-mode p-channel metal-oxide-semiconductor field-effect transistor (PMOSFET) is fabricated on a strained Si layer for the first time. A biaxial strain in a thin Si layer is produced by pseudomorphically growing this layer on a Ge0.25Si0.75 buffer layer which is grown on a Si substrate. At higher magnitude of gate bias, channel mobility of a strained Si PMOSFET has been found to be 50% higher than that of an identically processed conventional Si PMOSFET.
Low bias electron cyclotron resonance plasma etching of GaN, AlN, and InN
Authors: Pearton S. J. , Abernathy C. R. , Ren F.
Published: July 2002

Highly anisotropic dry etching of GaN, AlN, and InN was obtained at low dc self-bias in electron cyclotron resonance Cl2/H2 or CH4/H2/Ar discharges. The Cl2/H2 chemistry produces etch rates of ∼1100 Å min−1 for AlN and ∼700 Å min−1 for GaN at −150 V and 1 mTorr for high microwave powers (1000 W), while the CH4/H2/Ar mixture etches InN at ∼350 Å min−1 at −250 V under similar conditions. The surfaces of the III-V nitrides remain stoichiometric without requiring a wet-etch cleanup. The microwave enhancement of the discharges produces these practical etch rates, the highest reported for the nitrides, while keeping the dc bias relatively low. These low pressure, low bias conditions are well suited to pattern transfer processes in device fabrication.
Fabrication of nanometer-scale side-gated silicon field effect transistors with an atomic force microscope
Authors: Campbell P. M. , Snow E. S. , McMarr P. J.
Published: July 2002

The fabrication of nanometer-scale side-gated silicon field effect transistors using an atomic force microscope is reported. The probe tip was used to define nanometer-scale source, gate, and drain patterns by the local anodic oxidation of a passivated silicon (100) surface. These thin oxide patterns were used as etch masks for selective etching of the silicon to form the finished devices. Devices with critical features as small as 30 nm have been fabricated with this technique.
Optical and mechanical multistability in a dye-doped polymer fiber Fabry-Perot waveguide
Authors: Welker D. J. , Kuzyk M. G.
Published: July 2002

We report on the demonstration of both mechanical and optical multistability in a 110 μm diameter and 2.5 cm long Fabry-Perot cavity defined in a dye-doped polymer optical fiber waveguide. Such a device is a basic building block of optical and mechanical logic.
Analysis of the operational error of heat flux transducers placed on wall surfaces
Authors: Baba Tetsuya , Ono Akira , Hattori Susumu
Published: July 2002

The operational error in the heat flux measurements is theoretically investigated when the heat flux from a furnace wall to the environment is measured by a heat flux transducer. Change of the original heat flux, which is caused by placing a transducer on the furnace wall, is clarified by solving a three-dimensional heat transfer problem. The operational error is explicitly given by a simple equation taking into account the thermal properties of the furnace wall and the transducer. Numerical results are also provided for a typical application to industrial furnaces.
Photoacoustic calorimetry system for glancing incidence mirror absorptance measurements
Authors: Kimura W. D. , Ford D. H.
Published: July 2002

A system for measuring the absorptance of mirrors at angles of incidence from 0° to >89° for both s- and p-polarized light is described. Photoacoustic calorimetry is used in which the piezoelectric transducer is directly attached to the back of the mirror substrate. Determination of absolute absorptance is performed using a laser energy ratiometer at near normal incidence. The procedure for accurately aligning the laser beam to the mirror surface is described, as well as a method to compensate for the transducer dependence on the laser beam footprint shape. This system has been used successfully to measure the absorptance characteristics of metal mirrors and dielectric overcoated metal mirrors at several laser wavelengths. Sample results are given. Other applications of this technique are discussed.
Improvement of SiO2/Si interface by low-temperature annealing in wet atmosphere
Authors: Sano N. , Sekiya M. , Hara M. , Kohno A. , Sameshima T.
Published: July 2002

A postannealing technique was developed in order to improve the quality of SiO2 films formed by a parallel-plate remote plasma chemical vapor deposition. The wave number of the antisymmetric stretching mode of Si–O–Si bonding in the SiO2 film increased from 1058 to 1069 cm−1 by an annealing in H2O vapor at 270 °C. It was estimated that averaged bonding angle of Si–O–Si was widened from 137.8° to 141.0°. The annealing in the H2O vapor ambient at 270 °C for 30 min efficiently reduced the interface trap density to 2.0×1010 cm−2 eV−1 and the effective oxide charges density from 7×1011 to 5×109 cm−2 for a metal-oxide-semiconductor (MOS) diode using the SiO2 film.
Femtosecond streak tube
Authors: Kinoshita K. , Ito M. , Suzuki Y.
Published: July 2002

A new design concept of a streak tube is conceived to obtain femtosecond temporal resolution. It is based on four factors as follows. First, in order to decrease the photoelectron transit time spread, one must investigate how high electric field is practically usable near the photocathode. It is found that the value can be increased up to ∼6 kV/mm and this is used as a design value. Second, as the other method to decrease the photoelectron transit time spread, an electromagnetic focusing method must be adopted because there is no region similar to the focusing section of an electrostatic focusing type where the electric potential is low. Third, the focusing magnetic field should be located in a limited region to obtain a very high sweep speed of ∼2×108 m/s. And fourth, in the operation, a special readjustment of the focusing magnetic field should be performed to compensate the photoelectron beam defocusing caused by the very rapid transient deflection field. Based on the above, a new streak tube has been designed, manufactured, and tested. The limiting temporal resolution of ∼400 fs has been predicted theoretically and the value less than ∼500 fs has been experimentally produced.
New tilted-poles Wien filter with enhanced performance
Authors: Leal-Quiros E. , Prelas M. A.
Published: July 2002

The Wien filter is an E×B deflecting analyzer with the electrostatic field perpendicular to the magnetostatic field. The twofold functions of the Wien filter are as an energy analyzer as well as a mass analyzer. It has very high resolution for paraxial charged-particle beams with V=E/B, the Wien velocity. Two Wien filters, a tilted-poles Wien filter, and a classical parallel-rectangular-poles Wien filter were built and tested for electrons up to 3.5 keV and protons beams of 200 eV. (The tilted-poles Wien filter is a new diagnostic developed by the authors.) The performance of the two is compared, and the tilted-poles Wien filter has superior resolution to the classical Wien filter. Both Wien filters appear to have features useful for high-temperature plasma diagnostics, including simultaneous measurement of energy and mass spectra, and high resolution.
Optimization of CCD-based energy-modulated x-ray microtomography
Authors: Bonse U. , Nusshardt R. , Busch F. , Pahl R. , Johnson Q. C. , Kinney J. H. , Saroyan R. A. , Nichols M. C.
Published: July 2002

Employing asymmetric Bragg reflection at the monochromator we obtain a wide and practically parallel synchrotron-radiation beam which, when combined with the use of a CCD detector, enables us to perform chemically specific, high-speed and high-resolution tomography. We present recent results obtained with this new method. The actual resolution achieved was determined from the measured line-spread function of the complete detection system which includes the CCD, the fluorescent screen, and the lens used for optical magnification. The modulation-transfer function (MTF) calculated from the line-spread function shows that with only twofold magnification and at 3% contrast detectability about 28 line pairs per mm are resolved. Extrapolating from this result we find that with an optical magnification of 7:1 about 100 line pairs per mm should be resolved. Ways to optimize the method further are discussed.
Imaging system with an amorphous silicon linear sensor
Authors: Hasegawa Ken-ichi , Mochiki Koh-ichi , Takahashi Hiroyuki , Namatame Shuji , Satow Yoshinori
Published: July 2002

An amorphous silicon (a-Si) linear image sensor with a long active length and good spatial resolution has been applied to two-dimensional x-ray imaging. An area-to-line converter using plastic optical fibers (250 μm φ) with a Gd2 O2 S phosphor sheet has been constructed and attached to the sensor. This 2D detector has only 32×32 channels, but there is no technical limit for constructing a larger area detector. An EXAFS experiment is also presented for demonstration of the utility of the detector.
Resonance techniques and apparatus for elastic-wave velocity determination in thin metal plates
Authors: Petersen G. L. , Chick B. B. , Fortunko C. M. , Hirao M.
Published: July 2002

The principles of operation of a new pulsed ultrasonic resonance spectrometer are presented. The system incorporates: (1) the use of electromagnetic-acoustic transducers (EMATs), (2) a method of obtaining acoustic signals similar to the sampled continuous-wave scheme described by Bolef and Miller, (3) the Clark method of recording line shapes, and (4) a high power gated rf amplifier and a unique implementation of superheterodyne and quadrature phase sensitive detection circuitry. The result is a spectrometer capable of measuring both shear and longitudinal ultrasonic velocities in very thin samples with much greater reproducibility than other pulse methods. It also has applicability in measuring attenuation and other physical properties such as composite material bonding that can be accessed using ultrasound. Experimental results of tests using EMATs in the 0.1–20 MHz range on thin (1.27 and 2.49 mm thick) aluminum sheets are presented.
Fourier transform infrared microscopical analysis with synchrotron radiation: The microscope optics and system performance (invited)
Authors: Reffner John A. , Martoglio Pamela A. , Williams Gwyn P.
Published: July 2002

When a Fourier transform infrared microspectrometer was first interfaced with the National Synchrotron Light Source in September 1993, there was an instant realization that the performance at the diffraction limit had increased 40–100 times. The synchrotron source transformed the IR microspectrometer into a true IR microprobe, providing high-quality IR spectra for probe diameters at the diffraction limit. The combination of IR microspectroscopy and synchrotron radiation provides a powerful new tool for molecular spectroscopy. The ability to perform IR microspectroscopy with synchrotron radiation is still under development at Brookhaven National Laboratory, but several initial studies have been completed that demonstrate the broad-ranging applications of this technology and its potential for materials characterization.
Neutron yield measurements by use of foil activation at JT-60U
Authors: Hoek Magnus , Nishitani Takeo , Ikeda Yujiro , Morioka Atsuhiko
Published: July 2002

To study the 14 MeV neutron emission, the neutron yield measurements have been complemented by a recently installed neutron activation system. By using threshold reactions (Si, Al, and Cu foils), it is possible to distinguish between the 2.5 and 14 MeV neutron emission. Neutron transport calculations have been performed using Monte Carlo trajectory sampling methods (MCNP code) in order to determine the neutron fluency and energy distribution at the irradiation position. The results from the MCNP calculations together with the known cross sections of the foils, make it possible to calculate a calibration factor, which relates the fluency at the irradiation position to the total fluency from the JT-60U plasma. The accuracy of these calculations have been confirmed (∼20%) by comparing the total 2.5 MeV neutron yields obtained from foil activation, with those obtained from the fission chambers, which were calibrated using a 252Cf source. The efficiency calibration of the HP-Ge detector have been performed using a set of calibration sources. However, due to sum-coincidence effects, the efficiency is expected to have large errors (∼10%).