bluuebunny/crossref_metadata_2025 huggingface dataset:
Rice Gene Pool for Tarai and Inner Tarai Areas of Nepal
Authors: Joshi Bal K
Published: June 2010

Knowledge on crop gene pool helps to develop varieties, to know the potential sources forbreeding materials and to develop strategy for sustainable use and conservation. The amount ofgenetic diversity presents depends on the number and diversity of the original ancestorsinvolved in the creation of a germplasm pool, existing landraces and wild species. The objectiveof this research was to study the diversity of rice gene pool present in the Nepalese improvedrice cultivars and landraces adapted to Tarai and Inner Tarai (<1000 m). Pedigrees of 28Nepalese rice cultivars were examined and surveyed the literature for distribution of landracesand wild relatives of rice. Crosses among indica rice gene pool are more common and use ofjaponica and nivara species were less common. There are 28 improved rice cultivars, >500landraces, and 6 wild species and relatives of rice adapted to Tarai and Inner Tarai. Eightcountries are the origins for 28 cultivars. In Nepal 4 cultivars were bred and developed using alocal landrace and exotic genotypes. A total of 35 ancestors originated in 11 different countrieswere used to develop these 28 cultivars. Highest number of ancestors was from India. Use ofancestors of both sativa and nivara species having indica and japonica types indicated thecollection of wide gene pool. Most of the ancestors were sativa (60.00%) and indica (65.71%).Genetic erosion is observed in rice diversity therefore, in situ, on farm and ex situ conservationsare necessary for maintaining the genetic variation. Utilization of local landraces in breedingprogram may be the good way of genetic resources conservation. Gene pool from theselandraces along with international gene pool could make towards success in developing highyielding cultivars with wide adaptability and/or site specific. In this study, cultivars andlandraces surveyed represent a wide range of variation for different areas of origin andadaptation. This genetic diversity is very useful for further rice improvement and should beconserved both ex situ and in situ.Key words: Ancestor; Landrace; Nepalese rice cultivar; Rice gene pool; Tarai and Inner TaraiDOI: 10.3126/narj.v6i0.3339Nepal Agriculture Research Journal Vol.6 2005 pp.10-22
Correlation and Path Coefficient Analyses in Sugarcane
Authors: Chaudhary Rewati R , Joshi Bal K
Published: June 2010

This study was conducted to determine the contribution of different traits to cane yield insugarcane (Saccharum officinarum L). Sixty-five clones were evaluated in a replicated fieldexperiment at Sugarcane Research Programme, Jitpur, Nepal in 2003 for six morphologicalcharacters under irrigated conditions. Analysis of variance revealed significant differences for allthe characters studied. Cane yield showed positively and highly significant correlation withsingle cane weight, stalk length and millable cane number. There was also positively significantcorrelation of cane diameter and number of internode with cane yield. Length of internode hadpositive non-significant correlation with cane yield. Single cane weight had the highest positivedirect effect on cane yield followed by millable cane number. Stalk diameter and stalk lengthwas positively and significantly correlated with cane yield, which was due to indirect effect ofsingle cane weight. Results indicate that the genotypes should be selected on the basis of singlecane weight and millable cane number for getting higher sugarcane yield.Key words: Cane yield; correlation; path coefficient; sugarcaneDOI: 10.3126/narj.v6i0.3340Nepal Agriculture Research Journal Vol.6 2005 pp24-27
Performance of Different Size True Potato Seed Seedling Tubers at Khumaltar
Authors: Adhikari Ram C
Published: June 2010

A field study was carried out at Khumaltar-Lalitpur, during 2002-2004 to evaluate and comparethe performance of different sizes of seedling tubers (1-5 g, 5-10 g, 10-20 g and 20-40 g) of truepotato seed (TPS) with whole and half cut seed tubers of Desiree of 20-40 g size at 60- × 25-cmspacing. Percent emergence, plant height, ground cover by foliage, stems/plant, number of tubersper plant, marketable and total yields were significantly increased with the increase in seedlingtubers weight as compared to whole and half cut seed tubers of Desiree. Late blight(Phytophthora infestans L.) disease was quite low in the TPS crops than Desiree. Both wholeand half cut seed tubers of Desiree produced significantly higher average per tuber weight.Uniformity of the tubers harvested from different sizes of seedling tubers was statisticallysimilar and tubers from Desiree were statistically uniform as compared to seedling tubers. Thethree years result suggests that more than 1 g size seedling tubers can be successfully used forpotato production as from the seed tubers of any standard variety.Key words: Desiree; seedling tuber; tuber size; tuber yieldDOI: 10.3126/narj.v6i0.3341Nepal Agriculture Research Journal Vol.6 2005 pp.28-34
Response of Wet Seeded Rice Varieties to Sowing Dates
Authors: Shah Mishri L , Bhurer Kailash P
Published: June 2010

The experiment was conducted at Regional Agriculture Research Station, Parwanipur in twoconsecutive years to find out the suitable rice varieties for wet seeding conditions in relation tosowing dates. Yield components like tillers number/m2, number of filled grains/panicle and1000-grain weight were found in the decreasing trend from the seeding of 15 of June onward.The percent decrease in the grain yield was 14.1, 31.8 and 50.6 in 1998/99 where as 4.8, 7.9 and49.6 in 1999/00 on June 29 to July 14 seeding dates respectively as compared to 15 June seedingdate. Radha 4 in the first and Chaite 2 in the second year recorded the highest grain yield of3757 and 4197 kg/ha respectively. Interaction effect of the sowing dates and varieties washighly significant. Radha 4 produced the highest grain yield of 5039 kg/ha in 1998/99 where asRadha 4 and Chaite 6 were found at par in 1999/2000 seeded on 15 June. Radha 4 was the bestvariety for wet seeded conditions when seeded on 15 June. Chaite 2 had been observed goodyielder in all seeding dates among the tested varieties.Key words: Grain yield; seeding dates; wet seeding riceDOI: 10.3126/narj.v6i0.3342Nepal Agriculture Research Journal Vol.6 2005 pp.35-38
Planting Materials Seed Systems of Finger Millet, Rice and Taro in Jumla, Kaski and Bara Districts of Nepal
Authors: Baniya Bimal K , Tiwari Radha K , Chaudhary Pashupati , Shrestha Surendra K , Tiwari Pushpa R
Published: June 2010

Formal and informal seed supply systems of rice (Jumla, Bara and Kaski), finger millet and taro(Kaski) were studied in three ecosites of Nepal during 1999-2001 to understand the processes ofseed flow, seed production, seed selection and storage systems. A survey was conducted at 48 to96 households. Informal seed supply was the only system in Jumla and Kaski and formal systemexisted only in Bara. The main sources of seed were farmer's own saved seed (67-91%), seedfrom neighbors and relatives. Exchange of germplasm was the main basis of fulfillment fromother sources. All farmers obtained seed from their own village, while farmers introducedmaterials occasionally from outside village. Most of the farmers followed seed selection beforeor after crop harvest. Rice field selection and plant selection based on a fixed set of criteria wasthe common practice. Non lodged plants with more grain per panicle, bold grains, well-maturedand uniform plants, long panicle, true to type, good looking grains, free from diseases andinsects were the main rice seed selection criteria. All farmers from both sites stored rice seeds bylocal methods in the locally available containers. Mor and Mudkothi are the special strawcontainers to store rice seed in Bara. Dhara is a special mud structure used to store rice seeds inJumla. Finger millet seed supply system was mostly similar to that of rice seed system. Ninetyone percent farmers saved seed for their own use; however, many of them changed finger milletseeds lots or varieties regularly for their particular plot. Ears selection during harvest by setcriteria for seed purpose was the common practice. Farmers stored finger millet seed carefully insmall locally available containers and tried their best to maintain the quality of seed duringdifferent stage of seed production. Taro has diverse planting materials: cormels, corms witheyes, suckers and corm with small cormels. Taro planting materials management is totallyinformal and almost 89% farmers saved these materials for their use and replaced them mostlyafter 3 years. Farmers had fixed criteria of corms and cormels selection for planting purpose andfocus and more on disease free. Storage of planting materials was locally by using localmaterials and methods. Understanding of seed system in various crops helps to developconservation strategy.Key words: Seed flow; seed production; seed selection; seed storage; seed systemDOI: 10.3126/narj.v6i0.3343Nepal Agriculture Research Journal Vol.6 2005 pp.39-48
WALL-E and the “Many, Many” Maps: Toward User-Centred Ontologies forThe National Map
Authors: Poore Barbara S.
Published: June 2010

The symbolism of the film WALL-E is employed to argue that at the heart of problems with ontologies and the “Semantic Web” lies a misunderstanding of the relationship between man and machine. Originally created to be processed by intelligent machines, top-down ontologies for the Semantic Web have so far proved inadequate to deal with the messiness and emergent properties of current developments in social networking on the Internet. Bottom-up ontologies that incorporate crowd-sourced folksonomies may allow local users to contribute to and enrich national mapping efforts.
Introduction to William Stephenson's Quest for a Science of Subjectivity
Authors: Good James M.M.
Published: June 2010

In this introduction to the life and work of William Stephenson my aim is to provide a general overview of the development of his thinking and, more specifically, to highlight the importance he attached to the study of single cases. I also attempt to provide a context for an understanding of the significance of his ‘Tribute to Melanie Klein’. Some of the principal reasons for Stephenson's marginal status in the discipline of psychology will also emerge in the course of the article. I begin by outlining some of the central notions in Q-methodology. The early sections of the article trace his roots in the north of England – the setting for his schooling and university training in physics – and then outline his encounters with Charles Spearman and Cyril Burt at University College London. The subsequent section deals with his time at the University of Oxford Institute of Experimental Psychology and the wartime interruption to his career. The next few sections take us across the Atlantic and describe some of the most significant features of his work on Q-methodology. These sections also record the difficulties Stephenson experienced before he eventually secured a tenured position at the University of Missouri School of Journalism in Columbia. In the final section I attempt to situate Q-methodology in relation to some of the principal theoretical orientations in the human sciences.
Eigenvalue and Entropy Statistics for Products of Conjugate Random Quantum Channels
Authors: Collins Benoît , Nechita Ion
Published: June 2010

Using the graphical calculus and integration techniques introduced by the authors, we study the statistical properties of outputs of products of random quantum channels for entangled inputs. In particular, we revisit and generalize models of relevance for the recent counterexamples to the minimum output entropy additivity problems. Our main result is a classification of regimes for which the von Neumann entropy is lower on average than the elementary bounds that can be obtained with linear algebra techniques.
Obesity Prevalence in Nepal: Public Health Challenges in a Low-Income Nation during an Alarming Worldwide Trend
Authors: Vaidya Abhinav , Shakya Suraj , Krettek Alexandra
Published: June 2010

The future toll of the obesity epidemic will likely hit hardest in low- and middle-income countries. Ongoing urbanization promotes risk factors including sedentary lifestyle and fat- and sugar-laden diets. Low-income countries like Nepal experience a double disease burden: infectious diseases as well as rising incidence of noncommunicable diseases (e.g., cardiovascular disease and diabetes mellitus) frequently characterized by obesity. Nepal currently directs efforts towards curing disease but pays little attention to preventive actions. This article highlights obesity prevalence in Nepal, delineates the challenges identified by our pilot study (including low health literacy rates), and suggests strategies to overcome this trend.
Salve Journal of Functional Biomaterials, ad maiòra!
Authors: Puoci Francesco
Published: June 2010

The biomaterials field is one of the largest and fastest growing research areas both in the scientific community and in the industrial one. Biomaterials are the result of collaborations between different disciplines: chemistry, medicine, pharmacology, engineering and biology. The objective of this collaboration is to lead to the implementation of new devices to restore form and human body functions. The research on biomaterials reflects the constant need to replace or supplement human tissues and organs that have been physiologically compromised due to disease or traumatic events. [...]
Antioxidant Properties of European Cranberrybush Fruit (Viburnum opulus var. edule)
Authors: Rop Otakar , Reznicek Vojtech , Valsikova Magdalena , Jurikova Tunde , Mlcek Jiri , Kramarova Daniela
Published: June 2010

In the literature there is little available information concerning European cranberrybush fruit (Viburnum opulus var. edule). This plant can be cultivated, even in harsh climatic conditions, because of its low environmental demands, and it is possible to harvest the fruit even in the snow cover. The aim of this study was to determine the content of polyphenolics, antioxidant activity, flavonoids and vitamin C in the fruit of three cultivars ´Leningradskaya otbornaya´, ´Souzga´ and ´Taezny rubiny´ of this species. In the case of polyphenolics, high contents [up to 8.29 g of gallic acid/kg of fresh mass (FM)] were observed. The 1,1´-diphenyl-2-picrylhydrazyl (DPPH) and 2,2´-azinobis-3-ethyl-benzthiazino-6-sulphonic acid (ABTS) tests were applied to determine antioxidant activity, which was also high in comparison with other fruit species. The corresponding correlations between the polyphenolic content and antioxidant activity were in case of the DPPH test r2 = 0.88 and for the ABTS test r2 = 0.98. For comparison, the scavenging activity towards reactive oxygen species (superoxide anion, hydroxyl radical and nitric oxide) was determined by using a 25% fruit extract of particular cultivars. Antioxidant efficiency was also assessed using the rat liver slice model. Furthermore, the contents of flavonoids and vitamin C were assayed, giving values of 4.89 g/kg and 1.64 g/kg FM, respectively. The work should contribute to the popularization of this species as a promising crop plant in human nutrition.
Contribution of Online Trading of Used Goods to Resource Efficiency: An Empirical Study of eBay Users
Authors: Clausen Jens , Blättel-Mink Birgit , Erdmann Lorenz , Henseling Christine
Published: June 2010

This paper discusses the sustainability impact (contribution to sustainability, reduction of adverse environmental impacts) of online second-hand trading. A survey of eBay users shows that a relationship between the trading of used goods and the protection of natural resources is hardly realized. Secondly, the environmental motivation and the willingness to act in a sustainable manner differ widely between groups of consumers. Given these results from a user perspective, the paper tries to find some objective hints of online second-hand trading’s environmental impact. The greenhouse gas emissions resulting from the energy used for the trading transactions seem to be considerably lower than the emissions due to the (avoided) production of new goods. The paper concludes with a set of recommendations for second-hand trade and consumer policy. Information about the sustainability benefits of purchasing second-hand goods should be included in general consumer information, and arguments for changes in behavior should be targeted to different groups of consumers.
Impact of the Introduction of Biofuel in the Transportation Sector in Indonesia
Authors: Jupesta Joni
Published: June 2010

Indonesia faces serious energy problems; its status as an oil exporter has changed to that of a net oil importer. Additionally, a highly subsidized price of fossil fuels, combined with a high dependency on oil, burden Indonesia’s national budget. In 2006, the government enacted a Mix Energy Policy, which strives for a mixture of energy sources by introducing renewable energy into the existing energy systems. Among the several alternative renewable energy options, biofuel is perceived as having the most potential in Indonesia, due to favorable climate and the availability of land and technology. This paper assesses the impact of the introduction of biofuel in the transportation sector of Indonesia in terms of energy, economics and the environment. A linear programming model was built to simulate the impact of the introduction of biofuel. The author concludes that the introduction of biofuel may have a positive impact by partially replacing the oil used for domestic transportation, generating income due to export of excess production, creating jobs in several sectors, and reducing carbon emissions in a sustainable way. In the model, four scenarios are tested: under the scenario ‘land and technology’, with proper land allocation and technology development, biofuel production can reach 2,810 PJ/annum and reduce greenhouse gas emissions by 168 million tons/annum CO2-equivalent. Furthermore, a profit of 49 billion USD can be generated in 2025 (all maximum values).
Spatial genetic structure within size classes of the endangered tropical treeGuaiacum sanctum(Zygophyllaceae)
Authors: Fuchs Eric J. , Hamrick James. L.
Published: June 2010

•Premise of the study: Patterns of spatial genetic structure (SGS) were analyzed within a population of the endangered tropical treeGuaiacum sanctumlocated in northwestern Costa Rica. Documentation of these patterns provides insights into the gene dispersal mechanisms that play a central role in the maintenance and structure of genetic diversity within plant populations.

•Methods: Allozyme analyses were used to examine SGS in Palo Verde National Park, Costa Rica. The SGS was compared among three plots and different age classes.

•Key results: High levels of genetic diversity were found overall with a pooled genetic diversity ofHe= 0.302 (±0.02). Selfing was proposed as the proximate cause for significant levels of heterozygote deficiency observed across size classes and plots. An unexpected lack of SGS (rj< 0.02) was observed for all size classes, suggesting the mixing of seeds from several adults. A parent‐pair parentage analysis indicated that at least 48% of the smaller individuals within a plot were produced by parents located at distances of at least 150 m.

•Conclusions: Populations ofG. sanctumare established and maintained by bird‐mediated, moderate‐ to long‐distance seed dispersal, which results in a mixture of seeds from unrelated maternal individuals, effectively eliminating SGS. Proximity between individuals is, therefore, a poor predictor of family structure in this species. Long‐distance seed dispersal, coupled with estimates of high genetic diversity, suggests that this endangered species has the potential for natural regeneration and restoration given the availability of suitable habitats.
Characterisation of the heat-stable bacteriocin-producing and vancomycin-sensitive Pediococcus pentosaceus CFR B19 isolated from beans
Authors: Venkateshwari S. , Halami P. , Vijayendra S.
Published: June 2010

A bacteriocin-producing lactic culture with antilisterial activity was isolated from beans and identified as Pediococcus pentosaceus CFR B19. It was able to grow and produce bacteriocin at 41 °C but not at 50 °C. This isolate was found to be sensitive to vancomycin and produced heat-stable (at 121 °C for 15 min) bacteriocin. Molecular weight of the purified bacteriocin was found to be ∼4.8 kDa. This isolate can be used as a starter culture or co-culture in fermented milk products and the bacteriocin can be used as a natural preservative in various food products.
In vitro binding of mutagenic heterocyclic aromatic amines by Bifidobacterium pseudocatenulatum G4
Authors: Faridnia F. , Hussin A. , Saari N. , Mustafa S. , Yee L. , Manap M.
Published: June 2010

Consumption of probiotics has been associated with decreased risk of colon cancer and reported to have antimutagenic/
anti-carcinogenic properties. One possible mechanism for this effect involves physical binding of
the mutagenic compounds, such as heterocyclic amines (HCAs), to the bacteria. Therefore, the objective of this
study was to examine the binding capacity of bifidobacterial strains of human origin on mutagenic heterocyclic
amines which are suspected to play a role in human cancers. In vitro binding of the mutagens Trp-p-2, IQ, MeIQx,
7,8DiMeIQx and PhIP by three bacterial strains in two media of different pH was analysed using high performance
liquid chromatography. Bifidobacterium pseudocatenulatum G4 showed the highest decrease in the total HCAs
content, followed by Bifidobacterium longum, and Escherichia coli. pH affects binding capacity; the highest
binding was obtained at pH 6.8. Gram-positive tested strains were found to be consistently more effective than
the gram-negative strain. There were significant decreases in the amount of HCAs in the presence of different cell
concentrations of B. pseudocatenulatum G4; the highest decrease was detected at the concentration of 1010 cfu/ml.
The results showed that HCAs were able to bind with all bacterial strains tested in vitro, thus it may be possible to
decrease their absorption by human intestine and increase their elimination via faeces.
Probiotics lower plasma glucose in the high-fat fed C57BL/6J mouse
Authors: Andersson U. , Bränning C. , Ahrné S. , Molin G. , Alenfall J. , Önning G. , Nyman M. , Holm C.
Published: June 2010

Today, the gut microbiota is considered a key organ in host nutritional metabolism and recent data have suggested
that alterations in gut microbiota contribute to the development of type 2 diabetes and obesity. Accordingly, a whole
range of beneficial effects relating to inflammation and gut health have been observed following administration of
probiotics to both humans and different animal models. The objective of this study was to evaluate the metabolic
effects of an oral probiotic supplement, Lactobacillus plantarum DSM 15313, to high-fat diet (HFD) fed C57BL/6J
mice, a model of human obesity and early diabetes. The mice were fed the experimental diets for 20 weeks, after
which the HFD had induced an insulin-resistant state in both groups compared to the start of the study. The increase
in body weight during the HFD feeding was higher in the probiotic group than in the control group, however, there
were no significant differences in body fat content. Fasting plasma glucose levels were lower in the group fed the
probiotic supplement, whereas insulin and lipids were not different. Caecal levels of short-chain fatty acids were
not significantly different between the groups. An oral glucose tolerance test showed that the group fed probiotics
had a significantly lower insulin release compared to the control group, although the rate of glucose clearance was
not different. Taken together, these data indicate that L. plantarum DSM 15313 has anti-diabetic properties when
fed together with an HFD.
Comparing the efficacy of plasmid curing agents in Lactobacillus acidophilus
Authors: Karthikeyan V. , Santosh S.
Published: June 2010

This study was mainly focused on plasmid profiling and plasmid characterisation of Lactobacillus acidophilus
isolated from molasses. The secondary objective was to observe the efficacy of the plasmid curing agents acriflavine,
ethidium bromide, novobiocin and SDS on L. acidophilus. Plasmid-free strains and cured derivatives harbouring
only a single plasmid (6.2 kbp) were also obtained. Treatment of L. acidophilus with novobiocin at concentrations
of 2.4 µg/ml could produce a large number of chloramphenicol- variants at a very high frequency (4.6%). These
curing data confirmed that novobiocin acts as an effective curing agent for L. acidophilus.
Progressing Practices of Sustainable School Design
Authors: Chansomsak Sant , Vale Brenda
Published: June 2010

This article discusses a survey of contemporary practices of sustainable school design. It reveals a trend that relies on technological fixes and outlines barriers to this, primarily related to lack of awareness of benefits, and a limited perception centring on the process of pre-design, design and construction but ignoring the use phase. To overcome the barriers, this article argues that a paradigm shift is required, embracing the creation of sustainable systems through a holistic approach to education, so that design operates and interacts with other disciplines. The suggestions provided could also be used to improve sustainable architectural practices in general.
CSF Biomarkers for Alzheimer's Disease Diagnosis
Authors: Anoop A. , Singh Pradeep K. , Jacob Reeba S. , Maji Samir K.
Published: June 2010

Alzheimer's disease (AD) is the most common form of dementia that affects several million people worldwide. The major neuropathological hallmarks of AD are the presence of extracellular amyloid plaques that are composed of Aβ40 and Aβ42 and intracellular neurofibrillary tangles (NFT), which is composed of hyperphosphorylated protein Tau. While the amyloid plaques and NFT could define the disease progression involving neuronal loss and dysfunction, significant cognitive decline occurs before their appearance. Although significant advances in neuroimaging techniques provide the structure and physiology of brain of AD cases, the biomarker studies based on cerebrospinal fluid (CSF) and plasma represent the most direct and convenient means to study the disease progression. Biomarkers are useful in detecting the preclinical as well as symptomatic stages of AD. In this paper, we discuss the recent advancements of various biomarkers with particular emphasis on CSF biomarkers for monitoring the early development of AD before significant cognitive dysfunction.
POOR HEMOPOIETIC STEM CELL MOBILIZERS IN MULTIPLE MYELOMA : A SINGLE INSTITUTION EXPERIENCE
Authors: Ruiz-Delgado Guillermo Jose , Lopez-Otero Avril , Hernandez-Arizpe Ana , Ramirez-Medina Aura , Ruiz-Argüelles Guillermo Jose
Published: June 2010

In a single institution, in a group of 28 myeloma patients deemed eligible for autologous transplant, stem cell mobilization was attempted using filgrastim: 26 individuals were given 31 autografts employing 1-4 (median three) apheresis sessions, to obtain a target stem cell dose of 1 x 106 CD34 viable cells / Kg of the recipient. The median number of grafted CD34 cells was 7.56 x 106  / Kg of the recipient; the range being 0.92 to 14.8.  By defining as poor mobilizers individuals in which a cell collection of < 1 x 106 CD34 viable cells / Kg was obtained, a subset of eight poor mobilizers was identified; in two patients the autograft was aborted because of an extremely poor CD34 cell yield (< 0.2 x 106 CD34 viable cells / Kg of the recipient) after four apheresis sessions. The long-term overall survival of the patients grafted with > 1 x 106 CD34 viable cells / Kg was better (80% at 80 months) than those grafted with < 1 x 106 CD34 viable cells / Kg (67% at 76 months). Methods to improve stem cell mobilization are needed and may result in obtaining better results when autografting multiple myeloma patients.
Du terrain au laboratoire : Réaumur et l'histoire des fourmis
Authors: Drouin Jean-Marc
Published: June 2010

Ecrit il y a près de deux siècles et demi, resté longtemps inédit, exhumé il y a cinquante ans par un entomologiste américain, L'histoire des fourmis de Réaumur peut intéresser le pédagogue autant que l'historien. En effet, l'observation et l'expérimentation, le récit des expériences et l'analyse de ce qu'on appelle aujourd'hui les représentations, s'y trouvent mêlés d'une manière qui peut éclairer les pratiques actuelles d'enseignement et de vulgarisation dans ce domaine.
Difficultés d'une pédagogie de la découverte dans l'enseignement des sciences
Authors: Gohau Gabriel
Published: June 2010

La méthode pédagogique qui cherche à retrouver le cheminement de la découverte scientifique a été mise en oeuvre sous l'appellation "méthode de la redécouverte". L'analyse du rôle des expériences faites en classe montre comment cette méthode inductive peut se révéler tout aussi dogmatique que la méthode expositive.

Une véritable redécouverte exigerait que les élèves soient mis en situation de recherche, d'initiative, de tâtonnement, qu'un vrai dialogue s'instaure pour faire apparaître les représentations des élèves.

Pour mettre en oeuvre cette vraie pédagogie de la redécouverte, la formation des enseignants devrait être complétée par une initiation à l'histoire des obstacles épistémologiques et exigerait aussi une formation de chercheur.
Didactique et épistémologie : éclairages bachelardiens
Authors: Kerlan Alain
Published: June 2010

C'est autour de la notion de représentation que s'organise une bonne part des convergences de la didactique des sciences et de l'épistémologie bachelardienne. La place et l'importance de cette notion en didactique des sciences sont aujourd'hui telles qu'il faut s'interroger sur son sens et sa valeur. Les considérations pédagogiques qui traversent l'épistémologie de G. Bachelard doivent être examinées dans cette perspective. Elles relèvent d'une conception de la culture et de l'éducation scientifique qui doit faire l'objet d'une élucidation philosophique, et à laquelle l'entreprise didactique peut confronter ses propres valeurs.
Formation, modification et dissolution du concept d'hormone dans l'enseignement
Authors: Rumelhard Guy
Published: June 2010

Pour constituer un enseignement scientifique, diverses contraintes historiques et pédagogiques conduisent à un travail de désarticulation et de réarticulation des savoirs, des techniques expérimentales, des méthodologies démonstratives, des représentations, des concepts. L'exemple du concept d'hormone permet une analyse précise et une discussion critique de ce travail de modification successive des définitions, de changement des notions de base incluses dans la définition, d'accroissement de la complexité du savoir. Ce travail risque de majorer les schémas logiques ou linéaires, de faire disparaître l'historicité du savoir, ou bien de dissoudre le contenu du concept. En face de ces difficultés il ne s'agit pas de proposer une solution unique, mais bien plutôt des formulations successives possibles.
Association of geopotential height patterns with heavy rainfall events in Cyprus
Authors: Tymvios F. , Savvidou K. , Michaelides S. C.
Published: June 2010

Abstract. Dynamically induced rainfall is strongly connected with synoptic atmospheric circulation patterns at the upper levels. This study investigates the relationship between days of high precipitation volume events in the eastern Mediterranean and the associated geopotential height patterns at 500 hPa. To reduce the number of different patterns and to simplify the statistical processing, the input days were classified into clusters of synoptic cases having similar characteristics, by utilizing Kohonen Self Organizing Maps (SOM) architecture. Using this architecture, synoptic patterns were grouped into 9, 18, 27 and 36 clusters which were subsequently used in the analysis. The classification performance was tested by applying the method to extreme rainfall events in the eastern Mediterranean. The relationship of the synoptic upper air patterns (500 hPa height) and surface features (heavy rainfall events) was established, while the 36 member classification proved to be the most efficient.
Long-term bare fallow experiments offer new opportunities for the quantification and the study of stable carbon in soil
Authors: Barré P. , Eglin T. , Christensen B. T. , Ciais P. , Houot S. , Kätterer T. , van Oort F. , Peylin P. , Poulton P. R. , Romanenkov V. , Chenu C.
Published: June 2010

Abstract. The stability of soil carbon is a major source of uncertainty for the prediction of atmospheric CO2 concentration during the 21st century. Isolating experimentally the stable soil carbon from other, more vulnerable, pools is of prime importance for calibrating soil C models, and gaining insights on the mechanisms leading to soil organic carbon (SOC) stability. Long-term bare fallow experiments, in which the decay of SOC is monitored for decades after inputs from plant material have stopped, represent a unique opportunity to assess the stable organic carbon. We synthesized data from 6 bare fallow experiments of long-duration, covering a range of soil types and climate conditions, at Askov (Denmark), Grignon and Versailles (France), Kursk (Russia), Rothamsted (UK), and Ultuna (Sweden). The conceptual model of SOC being divided into three pools with increasing turnover times, a labile pool (~ years), an intermediate pool (~ decades) and a stable pool (~ several centuries or more) fits well with the long term SOC decays observed in bare fallow soils. The modeled stable pool estimates ranged from 2.7 gC kg−1 at Rothamsted to 6.8 gC kg−1 at Grignon. The uncertainty over the identification of the stable pool is large due to the short length of the fallow records relative to the time scales involved in the decay of soil C. At Versailles, where there is least uncertainty associated with the determination of a stable pool, the soil contains predominantly stable C after 80 years of continuous bare fallow. Such a site represents a unique research platform for future experimentation addressing the characteristics of stable SOC and its vulnerability to global change.
Climate resources analysis for use of planning in crop production and rainfall water management in the central highlands of Ethiopia, the case of Bishoftu district, Oromia region
Authors: Yemenu F. , Chemeda D.
Published: June 2010

Abstract. Agricultural practices and water resources management in the central highlands of Ethiopia is highly dependant and associated with climatic resources and their pattern and hence wise use of those resources is a priority for the region. Accordingly, a study was conducted to asses and critically quantity the climate resources of the central high lands of Ethiop, Bishoftu district. Thirty three years of weather record data has been used for the work. The onset, duration and end of the growing seasons were defined and quantified based on FAO and Reddy models while the dry and wet spell distributions and the drought events were calculated using the Markov chain models and the standardized precipitation index (SPI) respectively. The results revealed that the mean onset of the main (Kiremt) growing season was found to occur during the second meteorological decade and ended during the end of September. Similarly, though unreliable and only few occurred during the entire study period, the mean onset of the shorter (Belg) season was found to occur during the beginning of the first decade of April. The length of the growing season during the main rainy season, (Kiremt,) ranged from 112 to 144 days with a standard deviation of 9.6 days and coefficient of variation of 7.5%. However, the mean growing length during the Belg season was found to be 22.4 days with a standard deviation of 27 days and coefficient of variation of 122%. The results of analysis obtained both from the Markov Chain and Reddy models indicated higher probabilities of dry spell occurrences during the shorter season (Belg) but the occurrences of the same in the main rainy season (Kiremt) was very minimal. Like wise, the SPI model detected some drought events ranging from mild to severe classes in both seasons based on one a month time scale analysis. A considerable attention of maximizing crop harvest during the main rainy season is practically important.
Spin‐ and Spray‐Deposited Single‐Walled Carbon‐Nanotube Electrodes for Organic Solar Cells
Authors: Kim Sungsoo , Yim Jonghyuk , Wang Xuhua , Bradley Donal D.C. , Lee Soonil , deMello John C.
Published: June 2010

Organic bulk‐heterojunction solar cells using thin‐film single‐walled carbon‐nanotube (SWCNT) anodes deposited on glass are reported. Two types of SWCNT films are investigated: spin‐coated films from dichloroethane (DCE), and spray‐coated films from deionized water using sodium dodecyl sulphate (SDS) or sodium dodecyl benzene sulphonate (SDBS) as the surfactant. All of the films are found to be mechanically robust, with no tendency to delaminate from the underlying substrate during handling. Acid treatment with HNO3 yields high conductivities >1000 S cm−1 for all of the films, with values of up to 7694 ± 800 S cm−1 being obtained when using SDS as the surfactant. Sheet resistances of around 100 Ω sq−1 are obtained at reasonable transmission, for example, 128 ± 2 Ω sq−1 at 90% for DCE, 57 ± 3 Ω sq−1 at 65% for H2O:SDS, and 68 ± 5 Ω sq−1 at 70% for H2O:SDBS. Solar cells are fabricated by successively coating the SWCNT films with poly(3,4‐ethylenedioxythiophene):poly(styrene sulphonate) (PEDOT:PSS), a blend of regioregular poly(3‐hexylthiophene) (P3HT) and 1‐(3‐methoxy‐carbonyl)‐propyl‐1‐phenyl‐(6,6)C61 (PCBM), and LiF/Al. The resultant devices have respective power conversions of 2.3, 2.2 and 1.2% for DCE, H2O:SDS and H2O:SDBS, with the first two being at a virtual parity with reference devices using ITO‐coated glass as the anode (2.3%).
Controllable Synthesis of Graphene and Its Applications
Authors: Wei Dacheng , Liu Yunqi
Published: June 2010

Graphene, a two‐dimensional material, is regarded as one of the most promising candidates for future nanoelectronics due to its atomic thickness, excellent properties and widespread applications. As the first step to investigate its properties and finally to realize the practical applications, graphene must be synthesized in a controllable manner. Thus, controllable synthesis is of great significance, and received more and more attention recently. This Progress Report highlights recent advances in controllable synthesis of graphene, clarifies the problems, and prospects the future development in this field. The applications of the controllable synthesis are also discussed.
How to design an opioid drug that causes reduced tolerance and dependence
Authors: Berger Amy Chang , Whistler Jennifer L.
Published: June 2010

Mu opioid receptor (MOR) agonists such as morphine are extremely effective treatments for acute pain. In the setting of chronic pain, however, their long‐term utility is limited by the development of tolerance and physical dependence. Drug companies have tried to overcome these problems by simply “dialing up” signal transduction at the receptor, designing more potent and efficacious agonists and more long‐lasting formulations. Neither of these strategies has proven to be successful, however, because the net amount of signal transduction, particularly over extended periods of drug use, is a product of much more than the pharmacokinetic properties of potency, efficacy, half‐life, and bioavailability, the mainstays of traditional pharmaceutical screening. Both the quantity and quality of signal transduction are influenced by many regulated processes, including receptor desensitization, trafficking, and oligomerization. Importantly, the efficiency with which an agonist first stimulates signal transduction is not necessarily related to the efficiency with which it stimulates these other processes. Here we describe recent findings that suggest MOR agonists with diminished propensity to cause tolerance and dependence can be identified by screening drugs for the ability to induce MOR desensitization, endocytosis, and recycling. We also discuss preliminary evidence that heteromers of the delta opioid receptor and the MOR are pronociceptive, and that drugs that spare such heteromers may also induce reduced tolerance. ANN NEUROL 2010;67:559–569
Eindimensionale Metallketten in chiraler Umgebung–Kristallstruktur von helicalem Bis(dicarbonylrhodium(I))‐3,3′‐hexafluorglutaryl‐bis‐(1R)‐campherat
Authors: Schurig Volker , Gaus Hans , Scheer Peter , Walz Leonhard , von Schnering Hans Georg
Published: June 2010

Interessante Effekte bei der Stapelung wurden beim chiralen zweikernigen Rhodium(I)‐Komplex 1 beobachtet. Beide Metallatome sind Bestandteile einer einzigen eindimensionalen „Rhodiumkette”︁. Die Stapel bestehen abwechselnd aus zwei P‐und zwei M‐Helices. Als Folge von Stereoisomerie im Festzustand treten die energetisch unterschiedlichen Diastereomere (1R)‐(P)‐(1R)‐(M)‐(1R) auf.

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Di(1‐pyridinio)‐ und Di(1‐bipyridindiio)‐dihydrodibenzotetraaza[14]annulene
Authors: Adams Florian , Gompper Rudolf , Kujath Eckard
Published: June 2010

Tetraaza[14]annulene haben ähnliche Eigenschaften wie Porphyrine und Phthalocyanine, lassen sich aber leichter mit kationischen Gruppen substituieren. R in den Titelverbindungen 1 ist ein N‐gebundenes Pyridyl‐Kation oder 4,4′‐Bipyridinyl‐Dikation. 1 und seine Metallkomplexe kommen z.B. als neue Redoxsysteme und als Modelle für organische Supraleiter infrage.

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[{Ph2PCH2C(CF3)2O}NiH(PCy3)]: Hinweis auf einen Nickelhydrid‐Mechanismus bei der Ethen‐Oligomerisierung
Authors: Müller Ulrich , Keim Wilhelm , Krüger Carl , Betz Peter
Published: June 2010

Der Aufbau von α‐Olefinen aus Ethen in Gegenwart von Homogenkatalysatoren ist technisch von größter Bedeutung. Wie verläuft diese Reaktion? Modellversuche sprechen zugunsten des Nickelhydrid‐Mechanismus: Mit Tricyclohexylphosphan (PCy3) konnten die Komplexe 1 und 2 abgefangen werden.

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p‐Chinodimethan‐Analoga von Tetrathiafulvalen
Authors: Yamashita Yoshiro , Kobayashi Yasuo , Miyashi Tsutomu
Published: June 2010

Bessere Elektronendonoren als TTF sind chinoide Analoga, deren Prototyp 4 jetzt erstmals synthetisiert werden konnte. Wittig‐Horner‐Reaktion des Dithiol‐Derivats 1 mit dem Cyclopentadien‐Addukt von Benzochinon, 2, ergibt 3, das durch Retro‐Diels‐Alder‐Reaktion zu 4 – dunkelrote Kristalle – gespalten werden kann. TTF wird bei + 0.28 und + 0.64 V (vs. SCE) oxidiert, 1 aber schon bei −0.11 und −0.04 V (vs. SCE).

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Nickel(o)‐katalysierte Herstellung isomerer Carbonsäureamide–ligandgesteuerte β‐H‐ oder β′‐H‐Eliminierung
Authors: Hoberg Heinz , Guhl Dieter
Published: June 2010

Aus Isocyanaten und monosubstituierten Alkenen entstehen an (Lig)Nio unter C‐C‐Kupplung Azanickelacyclen wie 1. Durch gezielte Variation der Liganden (Lig) sowie Ausnutzung sterischer und/oder elektronischer Effekte kann entweder das β‐H‐Atom am Ring oder das exocyclische β′‐H‐Atom aktiviert werden; in Folgereaktionen entstehen dann mit hoher Selektivität katalytisch die beiden isomeren Carbonsäureamide 2 bzw. 3.

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Metal Organic Chemical Vapor Deposition (MOCVD) Perspectives and Prospects
Authors: Williams John O.
Published: June 2010

Review: Thin film epitaxial semiconductor structures of widely varying but controlled compositions and thickness can be prepared using MOCVD. The performance of the method is gauged against molecular beam epitaxy (MBE) and spray pyrolysis, and comment is made on the direction in which this area of research is going, for example, towards the processing of high‐Tc superconductors and ferroelectric oxides.
Polymers with a High Refractive Index and Low Optical Dispersion
Authors: Simmrock Hans‐U. , Mathy Alfred , Dominguez Ligia , Meyer Wolfgang H. , Wegner Gerhard
Published: June 2010

Communication: Organic Polyelectrolytes (I‐VII) known as Ionenes, with unique combinations of high refractive index (ND) and high Abbe number (VD, see figure) now compete with inorganic glasses for application in optics. Variation of the counterions allows the tuning of their chemical and optical properties.

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Imaging Organic Molecules with the Scanning Tunneling Microscope
Authors: Rabe Jürgen P.
Published: June 2010

Research News: The lack of electrical conductivity and the constant molecular mobility of organic molecules have, in the past, restricted the successful imaging of these systems by STM. Recently, however, a number of new organic systems have been imaged. Jürgen Rabe reports on these new developments and in the future will write regularly for ADVANCED MATERIALS on surface analysis techniques especially scanning microscopy methods.
Intelligent predictive control of a model helicopter's yaw angle
Authors: Mohammadzaheri Morteza , Chen Lei
Published: June 2010

In this paper the concept of Control Inertia is introduced and based on this concept, unexpectedly inadequate control behaviour of High Control Inertia systems is explained. Fuzzy compensators are then suggested to improve the control behaviour. This work is in the area of non‐model‐based control. In order to indicate the merit of the proposed technique, a neuro‐predictive (NP) control is designed and implemented on a highly non‐linear system, a lab helicopter, in a constrained situation. It is observed that the behaviour of the closed loop system under the NP controller either displays considerable function (with a low value of a particular design parameter) or is very slow (with high values of the same design parameter). In total, the control behaviour is very poor in comparison to existing fuzzy controllers, whereas NP is used effectively in the control of some other systems. Considering the concept of Control Inertia, a Sugeno‐type fuzzy compensator was added to the control loop to modify the control command. A newly designed neuro‐predictive control with fuzzy compensator (NPFC) improves the performance of the closed loop system significantly by the reduction of both overshoot and settling time. Furthermore, it is shown that the disturbance rejection of the NPFC controlled system as well as it parameter robustness is satisfactory.

Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Delay‐range‐dependent H∞ control for Markovian jump systems with mode‐dependent time delays
Authors: Wang Guoliang , Zhang Qingling , Sreeram Victor
Published: June 2010

This paper considers mean‐square exponential stability and H∞ control problems for Markovian jump systems (MJSs) with time delays which are time‐varying in an interval and depend on system mode. By exploiting a novel Lyapunov‐Krasovskii functional which takes into account the range of delay, and by making use of some techniques, new delay‐range‐dependent stability result and bounded real lemma for MJSs are obtained, where the introduction of the lower bound of delay is shown to be advantageous for reducing conservatism. Moreover, a sufficient condition for the solvability of the H∞ control problem is derived in terms of linear matrix inequalities. Finally, illustrative examples are presented to show the advantage and effectiveness of the proposed approaches.

Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Über Thiazole, XVII. Mitteil.: Die Darstellung von 1‐[Thiazolyl‐(2)]‐semicarbaziden
Authors: Beyer Hans , Schindler Wolfgang
Published: June 2010

Die Kondensation von 2‐Thio‐hydrazo‐dicarbonamid mit α‐halogenierten Ketoverbindungen führt zu einer neuen Stoffklasse, den 1‐[Thiazolyl‐(2)]‐semicarbaziden. Die verschieden substituierten Verbindungen wurden durch Mono‐ bzw. Diacetylderivate charakterisiert. Bei der Einwirkung von konz. Salpetersäure auf 1‐[4‐Phenyl‐thiazolyl‐(2)]‐semicarbazid entsteht [4‐(p‐Nitro‐phenyl)‐thiazolyl‐(2)]‐azo‐carbonamid.