Home About us Contact
|
Home About us Contact | ||
|
|
||
First Generation (first + generation)
Selected AbstractsGrowth, Maturation, Induced Spawning, and Production of the First Generation of South American Catfish, Pseudoplatystoma sp., in North AmericaJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2 2008Konrad Dabrowski Growth, plasma steroids, and the appearance of gonads (histology and gonadosomatic index) were followed in South American catfish (surubim, Pseudoplatystoma sp.) raised in captivity in the aquaculture facility at The Ohio State University, Columbus, Ohio, USA, from 2003 until 2006. Broodstock growth showed a great individual variation and it did not seem sex dependent. The levels of 11-ketotestosterone were high in males during the reproductive season. Three out of six females spawned after receiving two doses of carp pituitary extract (0.5 and 5 mg/kg) at 11-h intervals. Fertilization was performed in only one female in February 2006. Egg size was 0.73 ± 0.06 mm in diameter at stripping. Two males released sperm, and it was used for fertilization. Sperm concentrations were 24 × 109 and 15.5 × 109 spermatozoa/mL in Male 1 and Male 2, respectively, and viability was confirmed after activation in 0.3% NaCl. Embryo survival at 9 h after fertilization was 44 and 23% for Male 1 and Male 2, respectively. Embryos hatched 15 h after fertilization. Larvae were 3.53 ± 0.09 mm in length at hatching and were successfully raised (72% survival after 2 wks) using live brine shrimp nauplii. [source] Synthesis of Bithiophenesilane Dendrimer of the First Generation.CHEMINFORM, Issue 7 2006S. A. Ponomarenko Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF. [source] First Generation of Pentazole (HN5, Pentazolic Acid), the Final Azole, and a Zinc Pentazolate Salt in Solution: A New N-Dearylation of 1-(p-Methoxyphenyl) Pyrazoles, a 2-(p-Methoxyphenyl) Tetrazole and Application of the Methodology to 1-(p-Methoxyphenyl) Pentazole.CHEMINFORM, Issue 31 2003R. N. Butler Abstract For Abstract see ChemInform Abstract in Full Text. [source] InGaAs channel MOSFET with self-aligned source/drain MBE regrowth technologyPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 6 2009Uttam Singisetti Abstract InGaAs is a promising alternative channel material to Si for sub-22 nm node technology because of its low electron effective mass (m*) hence high electron velocities. We report a gate-first MOSFET process with self-aligned source/drain formation using non-selective MBE re-growth, suitable for realizing high performance scaled III-V MOSFETs. A W/Cr/SiO2 gate stack was defined on thin (4 nm/2.5 nm) InGaAs/InP channel by an alternating selective dry etch technique. A 5 nm Al2O3 layer was used as gate dielectric. An InAlAs bottom barrier provided vertical confinement of the channel. An in-situ H cleaning of the wafer leaves an epi-ready surface suitable for MBE or MOCVD regrowth. Source/Drain region were defined by non-selective MBE regrowth and in situ molybdenum contacts. First generation of devices fabricated using this process showed extremely low drive current of 2 ,A/,m. The drive current was limited by an extremely high source resistance. A regrowth gap between source/drain and gate was the cause for high source resistance. The gap in the regrowth was because of low growth temperature (400 °C). A modified high temperature growth technique resolved the problem. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Continuous glucose monitoring and closed-loop systemsDIABETIC MEDICINE, Issue 1 2006R. Hovorka Abstract Background The last two decades have witnessed unprecedented technological progress in the development of continuous glucose sensors, resulting in the first generation of commercial glucose monitors. This has fuelled the development of prototypes of a closed-loop system based on the combination of a continuous monitor, a control algorithm, and an insulin pump. Method A review of electromechanical closed-loop approaches is presented. This is followed by a review of existing prototypes and associated glucose sensors. A literature review was undertaken from 1960 to 2004. Results Two main approaches exist. The extracorporeal s.c.,s.c. approach employs subcutaneous glucose monitoring and subcutaneous insulin delivery. The implantable i.v.,i.p. approach adopts intravenous sampling and intraperitoneal insulin delivery. Feasibility of both solutions has been demonstrated in small-scale laboratory studies using either the classical proportional,integral,derivative controller or a model predictive controller. Performance in the home setting has yet to be demonstrated. Conclusions The glucose monitor remains the main limiting factor in the development of a commercially viable closed-loop system, as presently available monitors fail to demonstrate satisfactory characteristics in terms of reliability and/or accuracy. Regulatory issues are the second limiting factor. Closed-loop systems are likely to be used first by health-care professionals in controlled environments such as intensive care units. [source] Synergistic sex pheromone components of the grey-spotted tussock moth, Orgyia ericaeENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 3 2010Guo-Fa Chen Abstract The grey-spotted tussock moth, Orgyia ericae Germar (Lepidoptera: Lymantriidae), is an important pest of deciduous trees and woody scrublands in northern China. In a field trapping experiment conducted during the flight of the first generation of 2009, synthetic (Z)-6-heneicosen-11-one, a common Orgyia spp. sex pheromone component, attracted O. ericae males. Gas chromatography-mass spectrometry analyses (full scan or selected ion-monitoring mode) of pheromone gland extracts from females revealed the presence of a major, a minor, and a trace component, i.e., (6Z,9Z)-heneicosa-6,9-diene, (6Z,9Z)-tricosa-6,9-diene, and (Z)-6-heneicosen-11-one, respectively. Field experiments during the flight of the second generation showed that (6Z,9Z)-tricosa-6,9-diene, the minor component, was inactive alone or in any combination with the other two components, whereas (6Z,9Z)-heneicosa-6,9-diene and (Z)-6-heneicosen-11-one were weakly attractive when tested individually. However, traps baited with a binary blend of (6Z,9Z)-heneicosa-6,9-diene and (Z)-6-heneicosen-11-one caught seven-fold more moths than any other treatment (except the ternary blend), indicating a strong synergistic interaction between the two components. The analytical and field trapping data suggested that (6Z,9Z)-heneicosa-6,9-diene and (Z)-6-heneicosen-11-one are likely the key sex pheromone components of female O. ericae. This synergistic blend will be useful as an efficient monitoring tool, and possible control tool, to combat this economically and ecologically important forest defoliator. [source] Effects of elevated CO2 associated with maize on multiple generations of the cotton bollworm, Helicoverpa armigeraENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 1 2010Jin Yin Abstract Under elevated environmental carbon dioxide (CO2), leaf chewers tend to compensate for decreased leaf nutritional quality with increased consumption; mortality and development times also increase and cause a reduction in the fitness of leaf chewers. However, the effect of elevated CO2 on multiple successive generations of these and other insects is not well understood. Furthermore, information about the direct effects of increased environmental CO2 on developmental time and consumption of herbivores is lacking. In this paper, we tested the hypothesis that cascade effects of elevated CO2 through plants, rather than the direct effects of elevated CO2, are the main factors decreasing the fitness of cotton bollworm, Helicoverpa armigera Hübner (Lepidoptera: Noctuidae). We used two series of experiments to quantify the growth, development, and consumption of H. armigera fed on an artificial diet or C4 plants (maize) grown under two CO2 levels (ambient vs. double ambient). In the first series of experiments, elevated CO2 had no effect on the population abundance or individual consumption for three successive generations of cotton bollworms fed on an artificial diet. In the second series of experiments, elevated CO2 reduced population abundance of cotton bollworm larvae for two successive generations when they were fed maize milky grains. The specific effects were longer larval duration, lower fecundity, and decreased rm of cotton bollworms. Furthermore, elevated CO2 increased individual consumption when cotton bollworm was fed maize milky grains for two successive generations and decreased the population's total consumption in the first generation but increased it in the second generation. The results from this study indicate that: (1) The effects of elevated CO2 on three successive generations of cotton bollworm fed on artificial diet were weak, or even non-existent, and (2) elevated CO2 increased the consumption when cotton bollworm were fed maize. Our study also suggests that the damage inflicted by cotton bollworm on maize (a C4 plant) will be seriously affected by the increases in atmospheric CO2, which is unlike our previous results for spring wheat (a C3 plant). [source] Nutrigenomics: a case study in the measurement of insect response to nutritional qualityENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 1 2006Thomas A. Coudron Abstract Recent developments in the area of nutrigenomics hold the promise of providing valuable information about the impact of nutrition on a wide range of biochemical parameters by investigating how nutrition alters global gene expression patterns. Our goal is to use a nutrigenomics approach to identify insect molecular markers that could be used as early indicators of insect responses to different nutritional sources. Such molecular markers could be chosen for degree of expression and evaluated for suitability as nutritional biomarkers by examining developmental and generational expression. Ideal markers would be highly expressed, manifested in the first generation within one developmental stage, and consistent over many generations. Our objective for the current study was to illustrate the potential discovery of molecular markers using Perillus bioculatus (F.) (Heteroptera: Pentatomidae), when reared on an optimal vs. suboptimal diet, and analyze the presence of differentially expressed genes resulting from those treatments. In this paper we present preliminary results of microarray and subtractive hybridization experiments that represent the feasibility of using nutrigenomics to assist in analyzing insect responses to nutritional changes and dietary quality with the intent of stimulating further studies in this area. [source] Seasonal population changes of five parasitoids attacking the scale insect Nipponaclerda biwakoensis on the common reed, with special reference to predation by wintering birdsENTOMOLOGICAL SCIENCE, Issue 4 2005Shuji KANEKO Abstract Seasonal changes in the abundance of five species of hymenopterous parasitoids (four species of Encyrtidae and one species of Eulophidae) attacking the scale insect Nipponaclerda biwakoensis on the common reed were investigated for 2 years in Lake Biwa, with special reference to predation by the reed bunting, Emberiza schoeniclus, during winter. The scales settled on reed shoot stems under sheath leaves, passing through three discrete generations per year. The abundance of adult female scales increased exponentially from July (first generation) to December (third generation). Adult female scales of the third generation overwintered on reed shoots. During winter, female scale abundance dramatically declined, whereas the number of predation marks made by reed buntings using their bills on reed sheath leaves increased. The generations of all five parasitoids were synchronized with the host scale generations, and the five parasitoids overwintered as larvae inside the scale bodies. The abundance of parasitized scales and parasitoid adults emerging from the scales also increased from July to December, but greatly decreased during winter. The overall parasitism rate of the female scales remained at relatively low levels (less than 40%) throughout the year, including before and after winter. A bird exclusion experiment revealed that the dramatic winter decrease of the abundance of the scale and its five parasitoids was due to intensive and non-selective predation by the buntings on unparasitized and parasitized scales. Additionally, the proportion of immature parasitoids removed by birds varied between the five parasitoid species. Thus, seasonal population changes of the five scale parasitoids are considerably affected by bird predation on overwintering immature parasitoids. [source] Rearing Environment Affects the Brain Size of Guppies: Lab-Reared Guppies have Smaller Brains than Wild-Caught GuppiesETHOLOGY, Issue 2 2009James G. Burns Animals bred for captivity often have smaller brains and behave differently than their wild counterparts. These differences in brain size have been attributed to genetic changes resulting from, for example, inbreeding depression and pleiotropic effects of artificial selection for traits such as docility. A critical question, though, is whether these differences in brain size are due to plastic responses to the environment, not just genetic changes. We observed a large reduction in brain size in first generation, lab-reared female guppies compared with wild-caught ones (19% smaller telencephalon, 17% smaller optic tectum). We then reared first-generation, lab-born guppies in environments varying in spatial complexity and size in an attempt to isolate factors that might increase brain size and change temperament, but no significant differences in phenotype were observed. The results of these experiments show that, although the environmental factors responsible for the effect have not been found, even first generation lab-reared individuals can have smaller brains than wild individuals. [source] The Schooling of Women: Maternal Behavior and Child EnvironmentsETHOS, Issue 3 2001Professor Robert A. LeVine Beatrice Whiting was a member of the first generation of graduate students to be trained in psychological anthropology, and she has always presumed a broad range of connections between psychological and social processes. She salvaged the Six Cultures Study through an ecological analysis of its child-observation material, and she stimulated further studies, using quantitative and qualitative methods, of the ways in which broad categories like sex, age, and education influence child development. This article presents in overview a crosscultural research program on the effects of women's schooling that was influenced by her ideas. [source] On the Mechanism of the Reductive Metallation of Asymmetrically Substituted Silyl ChloridesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 1 2005Martin Oestreich Abstract An investigation of the stereochemical course of the reductive metallation of silyl chlorides with silicon-centred chirality has revealed two major events which are detrimental to stereoselection during silyl anion formation: (1) chloride-induced racemisation of silyl chlorides and (2) nonstereoselective formal dimerisation during metallation providing the corresponding disilane. In control experiments, the stereochemical course of these processes has been independently verified for the reductive metallation of the enantioenriched cyclic silyl chloride (SiS)- 7a (R = H, er , 88:12). A screening of several related derivatives of (SiS)- 7a led to the sterically encumbered silyl chloride (SiR)- 7c (R = iPr, er , 94:6) which displays some unique features. This structural modification prevents racemisation by lithium chloride (T < ,40 °C) as well as dimerisation (T < ,100 °C) thus allowing for the first generation of an asymmetrically substituted silyl anion (SiS)- 8c (er = 74:26) by reductive metallation of a silyl chloride with silicon-centred chirality. Moreover, the enantiospecificity of the preparation of (SiR)- 7c by chlorination [(SiS)- 9c , (SiR)- 7c] and its reduction with aluminium hydrides [(SiR)- 7c , (SiR)- 9c] have been unambiguously determined by X-ray crystallography as retention (,99%) and inversion (,99%), respectively. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Allergy-like reactions to iodinated contrast agents.FUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 3 2005A critical analysis Abstract Allergy-like reactions may occur following administration of iodinated contrast media (CM), mostly in at-risk patients (patients with history of previous reaction, history of allergy, co-treated with interleukin-2 or beta-blockers, etc.) but remain generally unpredictable. Severe and fatal reactions are very rare events. All categories of CM may induce such reactions, although first generation (high osmolar CM) have been found to induce a higher rate of adverse events than low osmolar CM. However, no differences were found between the two categories of CM with respect to mortality. Delayed reactions can also occur. There are no differences between the various categories of CM except for non-ionic dimers, which are more likely to induce such effect. Numerous clinical studies have evaluated the prophylactic value of drugs (mostly antihistamines and corticosteroids). Results are unclear and highly variable. Any prevention depends upon the mechanism involved. However, the mechanism of CM-induced allergy-like reaction remains disputed. Relatively recent data revived the hypothesis of a type-I hypersensitivity mechanism. Positive skin tests to CM have been reported. However, the affinity of IgE towards CM has been found to be very low in the only study which actually evaluated it. Other pathophysiological mechanisms (involving direct secretory effects on mast cells or basophils, or activation of the complement system associated or not with the plasma contact system) are also much debated. Anaphylaxis and anaphylactoid reactions are, in the end, clinically undistinguishable. [source] Local attachments and transnational everyday lives: second-generation Italians in SwitzerlandGLOBAL NETWORKS, Issue 3 2010SUSANNE WESSENDORF Abstract Many descendants of migrants grow up in the context of lively transnational social relations to their parents' homeland. Among southern Italian migrants in Switzerland, these relations are imbued with the wish to return among the first generation, a dream fostered since the beginning of their migration after the Second World War. Second-generation Italians have developed different ways of negotiating the transnational livelihoods fostered by their parents on the one hand, and the wish for local attachments on the other. In this article I discuss how the children of Italian migrants have created their own cultural repertoires of Italianità and belonging within Switzerland and with co-ethnic peers, and how, for some, this sense of belonging evokes the wish for ,roots migration', the relocation to the parents' homeland. With the example of two trajectories of local attachment and transnationalism among members of the second generation of the same origin, I question existing work on the second generation that assumes commonalities among them on the grounds of ethnicity and region of origin. [source] The labour market for nursing: a review of the labour supply literatureHEALTH ECONOMICS, Issue 6 2003Emanuela Antonazzo Abstract The need to ensure adequate numbers of motivated health professionals is at the forefront of the modernisation of the UK NHS. The aim of this paper is to assess current understanding of the labour supply behaviour of nurses, and to propose an agenda for further research. In particular, the paper reviews American and British economics literature that focuses on empirical econometric studies based on the classical static labour supply model. American research could be classified into first generation, second generation and recent empirical evidence. Advances in methods mirror those in the general labour economics literature, and include the use of limited dependent variable models and the treatment of sample selection issues. However, there is considerable variation in results, which depends on the methods used, particularly on the effect of wages. Only one study was found that used UK data, although other studies examined the determinants of turnover, quit rates and job satisfaction. The agenda for further empirical research includes the analysis of discontinuities in the labour supply function, the relative importance of pecuniary and non-pecuniary job characteristics, and the application of dynamic and family labour supply models to nursing research. Such research is crucial to the development of evidence-based policies. Copyright © 2002 John Wiley & Sons, Ltd. [source] Sedation and antihistamines: an update.HUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 7 2008Review of inter-drug differences using proportional impairment ratios Abstract Background The use of antihistamines (AHs) has been associated with cognitive and psychomotor impairments, largely caused by the sedative properties of many of these drugs. Due to the ambulant nature of the population using AHs, it is important to evaluate these effects using standardised methodology and psychometric tests. A previous extensive review of the literature collated the results of studies of H1 receptor antagonists to determine the extent to which a particular AH produced impairments on a battery of psychometric tests by calculating a proportional impairment ratio for each AH. Objective In light of a number of major studies published following the previous review, and the development of the second and new-generation AHs, the present review aims to add to the database and update the review, using the same methodology. Results and Conclusion The newer generation AHs appear to be the least impairing, and the first generation, as expected, appear to be the most impairing. There are also differences within the AH drug generations. The review highlights the necessity to consider the sedating potential of AHs, along with other factors such as efficacy, when prescribing AHs to ambulant patients. Copyright © 2008 John Wiley & Sons, Ltd. [source] Epidemiology of binge eating disorderINTERNATIONAL JOURNAL OF EATING DISORDERS, Issue S1 2003Ruth H. Striegel-Moore Abstract Objective First described over 50 years ago, binge eating disorder (BED) only recently has become the focus of epidemiologic studies. This article provides a comprehensive review of these studies. Method Relevant studies were examined and summarized in the form of a narrative review. Results Similar to the early studies of bulimia nervosa (BN), the first generation of epidemiologic studies of BED is limited in scope or methodology. They focus on prevalence rates and provide only basic demographic characteristics and often use less than optimal sampling or assessment methods. Discussion Results suggest that the demographic profile of BED may be more diverse than that of BN. Future studies should evaluate complex etiologic models in representative samples that include men and a broader range of ethnic minority groups. © 2003 by Wiley Perodicals, Inc. Int J Eat Disord 34: S19,S29, 2003. [source] Educational Attainments of Immigrant Offspring: Success or Segmented Assimilation?,INTERNATIONAL MIGRATION REVIEW, Issue 4 2002Monica Boyd In this article, I study the educational attainments of the adult offspring of immigrants, analyzing data from the 1996 panel of the Survey of Labour and Income Dynamics (SLID). Fielded annually since 1993 by Statistics Canada, respondents are asked for the first time in 1996 to report the birthplaces of their parents, making it possible to define and study not only the foreign-born population (the first generation), but also the second generation (Canadian born to foreign-born parents) and the third-plus generation (Canadian born to Canadian-born parents). The survey also asked respondents to indicate if they are members of a visible minority group, thus permitting a limited assessment of whether or not color conditions educational achievements of immigrant offspring. I find that "1.5" and second generation adults, age 20,64 have more years of schooling and higher percentages completing high school compared with the third-plus generation. Contrary to the segmented "underclass" assimilation model found in the United States, adult visible minority immigrant offspring in Canada exceed the educational attainments of other not-visible-minority groups. Although the analysis is hampered by small sample numbers, the results point to country differences in historical and contemporary race relations, and call for additional national and cross-national research. [source] High-yielding capacity building in irrigation system management: targeting managers and operators,,IRRIGATION AND DRAINAGE, Issue 3 2008Thierry Facon développement des capacités; gestion du système; Asie Abstract Irrigation management is facing complex challenges evolving with the transformation of agriculture, competition over resources, environmental concerns, without forgetting the critical objective of food production. Managers are ill prepared to meet these challenges and the FAO called for and initiated a massive retraining programme of engineers and managers on irrigation system modernization to address these issues, starting in Asia. Results from this first generation of interventions confirmed the lack of success of many investments and institutional reforms, gaps in capacity and training and the potential for achieving significant improvements at minimal cost by focusing on system operation. The FAO prepared new guidelines for improving system operation and management (MASSCOTE) based on service-oriented management concepts, tested them through training workshops in Nepal, India and China and is disseminating them through a second-generation training programme building on first- generation knowledge synthesis. This paper presents the FAO's strategic approach to capacity building on service-oriented management. It builds on the major lessons drawn from past programmes and is based on three interrelated thrusts: at the system, state and regional/global levels. Concepts, methodologies, lessons learned on upscaling to policy and long-term investment planning, limitations and conditions for success and future programme development are discussed. Copyright © 2008 Food and Agriculture Organization of the United Nations (FAO) and John Wiley & Sons, Ltd. La gestion de l'irrigation est confrontée à des défis complexes en évolution avec la transformation de l'agriculture, la concurrence sur les ressources, les préoccupations environnementales, sans oublier l'objectif critique de la production alimentaire. Les gestionnaires sont mal préparés pour répondre à ces défis et la FAO a lancé un vaste programme de nouvelle formation des ingénieurs et cadres sur la modernisation des systèmes d'irrigation pour traiter ces questions, en commençant par l'Asie. Les résultats de cette première génération d'interventions ont confirmé le manque de succès de beaucoup d'investissements et de réformes institutionnelles, les lacunes dans les capacités et la formation et les possibilités de parvenir à des améliorations significatives à peu de frais en se concentrant sur le fonctionnement du système. La FAO a élaboré de nouveaux guides pour améliorer l'exploitation et la gestion des systèmes (MASSCOTE) basés sur les concepts de service, les a testés par des ateliers de formation au Népal, en Inde et en Chine et les a diffusés par une deuxième génération de programmes de formation s'appuyant sur la synthèse des connaissances de première génération. Cet article présente l'approche stratégique de la FAO pour le renforcement des capacités de gestion orientée sur le service. Il s'appuie sur les principaux enseignements tirés des précédents programmes et repose sur trois axes étroitement liés: au niveau du système, de l'état et régional/mondial. Les concepts, les méthodes, les leçons apprises sur les politiques et la planification des investissements à long terme, les limites et les conditions du succès, et le développement des programmes futurs sont discutés. Copyright © 2008 Food and Agriculture Organization of the United Nations (FAO) and John Wiley & Sons, Ltd. [source] Life-long protein malnutrition in the rat (Rattus norvegicus) results in altered patterns of craniofacial growth and smaller individualsJOURNAL OF ANATOMY, Issue 6 2006Shannon L. Lobe Abstract Dietary protein is a limiting factor in mammalian growth, significantly affecting the non-linear trajectories of skeletal growth. Young females may be particularly vulnerable to protein malnutrition if the restriction is not lifted before they become reproductive. With such early malnutrition, limited amino acids would be partitioned between two physiological objectives, successful reproduction vs. continued growth. Thus, the consequences of protein malnutrition could affect more than one generation. However, few studies have quantified these cross-generational effects. Our objective was to test for differences in skeletal growth in a second generation of malnourished rats compared with rats malnourished only post-weaning, the first generation and with controls. In this longitudinal study we modelled the growth of 22 craniofacial measurements with the logistic Gompertz equation, and tested for differences in the equation's parameters among the diet groups. The female offspring of post-weaning malnourished dams did not catch up in size to the first generation or to controls, although certain aspects of their craniofacial skeleton were less affected than others. The second generation's growth trajectories resembled the longer and slower growth of the first malnourished generation. There was a complex interaction between developmental processes and early nutritional environment, which affected variation of adult size. [source] Response of multiple generations of beet armyworm, Spodoptera exigua (Hübner), feeding on transgenic Bt cottonJOURNAL OF APPLIED ENTOMOLOGY, Issue 2 2009G. Wu Abstract Development, reproduction and food utilization of three successive generations of beet armyworm, Spodoptera exigua (Hübner), fed on transgenic and non-transgenic Bt cotton were examined. Significantly longer larval life-span and lower pupal weight were observed in three successive generations of S. exigua fed on transgenic Bt cotton compared with non-transgenic Bt cotton. Significantly higher survival rate and adult fecundity of S. exigua were found in three successive generations of S. exigua fed on transgenic Bt cotton compared with non-transgenic Bt cotton. The survival rate and adult fecundity of S. exigua were occurred significant increase in the third generation compared with the first generation after feeding on transgenic Bt cotton. Significantly lower consumption, frass and relative growth rate (RGR) were observed in three successive generations of S. exigua fed on transgenic Bt cotton compared with non-transgenic Bt cotton. Cotton variety significantly affected all indices of larval consumption and utilization in three successive generations of S. exigua, except for efficiency of conversion of ingested food. However, beet armyworm generation only significantly affected RGR of S. exigua. The results of this study indicated food quality on the diet-utilization efficiency of S. exigua was different along with beet armyworm generation. Measuring multigenerational development and food utilization of S. exigua at individual and population level in response to Bacillus thuringiensis (Bt) can provide a more meaningful evaluation of long-term population dynamics than experiments on a single generation. It is imperative to develop an appropriate multigenerational pest management tactic to monitor the field population dynamics of non-target pests (e.g., beet armyworm) in agricultural Bt cotton ecosystem. [source] Short- and long-range dispersal of medfly, Ceratitis capitata (Dipt., Tephritidae), and its invasive potentialJOURNAL OF APPLIED ENTOMOLOGY, Issue 8 2007A. Meats Abstract:, Data were obtained from mark recapture trials pertaining to the dispersal of medfly, Ceratitis capitata (Dipt., Tephritidae), over both short (10,160 m) and very long distances (0.5,9.5 km) within the surveillance trapping array in Adelaide, Australia. They could be related to previously reported data sets by expressing the capture rates of each set in common terms that corrected for differences in recapture rate resulting from type of trap, season or climate. The mean capture rate at each distance from the point of release in each data set was expressed as a percentage of the real or inferred rate of that set at a distance of 100 m. The resulting distribution of dispersal distances conformed to both an inverse power model and a modified Cauchy model regardless of whether the present and previous data were combined or not. The modified Cauchy model inferred that the median distance flown was extremely short and 90% of flies displaced only 400,700 m despite the fact that a consistent trend in declining catch rates was obtained up to 9.5 km. The spread of invading propagules in quarantined zones in the first generation is likely to be limited by a decline to non-viable density within 1 km or less of the incursion point and the spread of larger infestations could be limited by the longevity of the dispersers. The results also have significance to the ability of surveillance trapping arrays to detect infestations and also to methods of distributing insects for the ,sterile insect technique'. [source] A practical method for predicting the short-time trend of bivoltine populations of Ips typographus (L.) (Col., Scolytidae)JOURNAL OF APPLIED ENTOMOLOGY, Issue 1 2006M. Faccoli Abstract:,Ips typographus is the main spruce pest of European forests. In most areas of the Italian Alps there are two generations per year; overwintering adults fly in May looking for trees suitable for breeding, their offspring emerge in summer, 7,8 weeks after tree colonization, and the adults of the second generation emerge in spring of the following year after overwintering under the bark or in the litter. A long-term population monitoring was carried out in north-east Italy with the aim at developing a prediction model able to estimate the population density of the following year. Between 1996 and 2004, pheromone traps monitored populations of I. typographus annually. Monitoring lasted 4 months (May,August), with replacement of pheromone dispensers after 8 weeks. Insects trapped before dispenser change were called ,spring captures' (May,June), and included both overwintering and re-emerging adults. Beetles caught after dispenser change were called ,summer captures' (July,August), and included the adults of the first generation. The results show a high positive correlation between the ratio of summer and spring captures of one year (Summerx/Springx), and the ratio of total captures of the following year (Yx+1) and those of the current year (Yx) (Yx+1/Yx). Summerx/Springx lower than 0.62 indicate decreasing populations in the following year (Yx+1/Yx <1), whereas Summerx/Springx higher than 0.62 indicate increasing populations (Yx+1/Yx >1). The applicability of the model in the study of I. typographus risk of outbreak and in the forest management is discussed. The prediction of the short-time trend of the population allows assessing its density in the following year, and therefore the risk of outbreak. [source] Challenges of antiangiogenic cancer therapy: trials and errors, and renewed hopeJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 3 2007Miguel Ángel Medina ,,Introduction ,,What can we learn from the previous failures? ,,Signs of hope ,,Another turn of the screw: a surrogate marker, at last ,,Future avenues for the vascular therapy of cancer Abstract Angiogenesis inhibition has been proposed as a general strategy to fight cancer. However, in spite of the promising preclinical results, a first generation of antiangiogenic compounds yielded poor results in clinical trials. Conceptual errors and mistakes in the design of trials and in the definition of clinical end-points could account for these negative results. In this context of discouraging results, a second generation of antiangiogenic therapies is showing positive results in phases II and III trials at the beginning of the twenty-first century. In fact, several combined treatments with conventional chemotherapy and antiangiogenic compounds have been recently approved. The discovery and pharmacological development of future generations of angiogenesis inhibitors will benefit from further advances in the understanding of the mechanisms involved in human angiogenesis. New styles of trials are necessary, to avoid missing potential therapeutic effects. Different clinical end-points, new surrogate biomarkers and methods of imaging will be helpful in this process. Real efficacy in clinical trials may come with the combined use of antiangiogenic agents with conventional chemotherapy or radiotherapy, and combinations of several antiangiogenic compounds with different mechanisms of action. Finally, the existing antiangiogenic strategies should include other approaches such as vascular targeting or angioprevention. [source] Caenorhabditis elegans PI3K mutants reveal novel genes underlying exceptional stress resistance and lifespanAGING CELL, Issue 6 2009Srinivas Ayyadevara Summary Two age-1 nonsense mutants, truncating the class-I phosphatidylinositol 3-kinase catalytic subunit (PI3KCS) before its kinase domain, confer extraordinary longevity and stress-resistance to Caenorhabditis elegans. These traits, unique to second-generation homozygotes, are blunted at the first generation and are largely reversed by additional mutations to DAF-16/FOXO, a transcription factor downstream of AGE-1 in insulin-like signaling. The strong age-1 alleles (mg44, m333) were compared with the weaker hx546 allele on expression microarrays, testing four independent cohorts of each allele. Among 276 genes with significantly differential expression, 92% showed fewer transcripts in adults carrying strong age-1 alleles rather than hx546. This proportion is significantly greater than the slight bias observed when contrasting age-1 alleles to wild-type worms. Thus, transcriptional changes peculiar to nonsense alleles primarily involve either gene silencing or failure of transcriptional activation. A subset of genes responding preferentially to age-1- nonsense alleles was reassessed by real-time polymerase chain reaction, in worms bearing strong or weak age-1 alleles; nearly all of these were significantly more responsive to the age-1(mg44) allele than to age-1(hx546). Additional mutation of daf-16 reverted the majority of altered mg44 -F2 expression levels to approximately wild-type values, although a substantial number of genes remained significantly distinct from wild-type, implying that age-1(mg44) modulates transcription through both DAF-16/FOXO-dependent and independent channels. When age-1 -inhibited genes were targeted by RNA interference (RNAi) in wild-type or age-1(hx546) adults, most conferred significant oxidative-stress protection. RNAi constructs targeting two of those genes were shown previously to extend life, and RNAi's targeting five novel genes were found here to increase lifespan. PI3K - null mutants may thus implicate novel mechanisms of life extension. [source] Evolutionary combinatorial chemistry, a novel tool for SAR studies on peptide transport across the blood,brain barrier.JOURNAL OF PEPTIDE SCIENCE, Issue 12 2005Part 2. Abstract The use of high-throughput methods in drug discovery allows the generation and testing of a large number of compounds, but at the price of providing redundant information. Evolutionary combinatorial chemistry combines the selection and synthesis of biologically active compounds with artificial intelligence optimization methods, such as genetic algorithms (GA). Drug candidates for the treatment of central nervous system (CNS) disorders must overcome the blood,brain barrier (BBB). This paper reports a new genetic algorithm that searches for the optimal physicochemical properties for peptide transport across the blood,brain barrier. A first generation of peptides has been generated and synthesized. Due to the high content of N -methyl amino acids present in most of these peptides, their syntheses were especially challenging due to over-incorporations, deletions and DKP formations. Distinct fragmentation patterns during peptide cleavage have been identified. The first generation of peptides has been studied by evaluation techniques such as immobilized artificial membrane chromatography (IAMC), a cell-based assay, log Poctanol/water calculations, etc. Finally, a second generation has been proposed. Copyright © 2005 European Peptide Society and John Wiley & Sons, Ltd. [source] Lost Mold Rapid Infiltration Forming of Mesoscale Ceramics: Part 1, FabricationJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 2009Nicholas E. Antolino Free-standing mesoscale (340 ,m × 30 ,m × 20 ,m) bend bars with an aspect ratio over 15:1 and an edge resolution as fine as a single grain diameter (,400 nm) have been fabricated in large numbers on refractory ceramic substrates by combining a novel powder processing approach with photoresist molds and an innovative lost-mold thermal process. The colloid and interfacial chemistry of the nanoscale zirconia particulates has been modeled and used to prepare highly concentrated suspensions. Engineering solutions to challenges in mold fabrication and casting have yielded free-standing, crack-free parts. Molds are fabricated using high-aspect-ratio photoresist on ceramic substrates. Green parts are formed using a rapid infiltration method that exploits the shear thinning behavior of the highly concentrated ceramic suspension in combination with gelcasting. The mold is thermally decomposed and the parts are sintered in place on the ceramic substrate. Chemically aided attrition milling disperses and concentrates the as-received 3Y-TZP powder to produce a dense, fine-grained sintered microstructure. Initial three-point bend strength data are comparable to that of conventional zirconia; however, geometric irregularities (e.g., trapezoidal cross sections) are present in this first generation and are discussed with respect to the distribution of bend strength. [source] Review article: the treatment of non-alcoholic steatohepatitis with thiazolidinedionesALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 10 2005H. REYNAERT Summary It is generally accepted that non-alcoholic fatty liver disease will be the most frequent liver disease in the near future and that the management of patients with non-alcoholic fatty liver disease will be a challenge for hepatologists in the next decades. Non-alcoholic fatty liver disease is considered the hepatic manifestation of the metabolic syndrome, in which insulin resistance plays a crucial role. Although steatosis will often not progress to severe liver disease, in some patients, it results in cirrhosis and even hepatocellular carcinoma. Therefore, it is important to identify those patients at risk for developing fibrosis. Age, diabetes, obesity and hypertriglyceridaemia are independent risk factors for fibrosis in patients with elevated serum alanine aminotransferase levels and steatosis on ultrasound. The presence of multiple metabolic disorders increases the risk. Apart from diet, exercise and correction of underlying metabolic abnormalities, no specific treatment is available at the moment. Theoretically, thiazolidinediones are an attractive way to treat non-alcoholic fatty liver disease, because they improve insulin resistance. Some preliminary studies with thiazolidinediones were encouraging, as steatosis, inflammation and fibrosis improved in a substantial number of patients. Although no serious side effects occurred in the pilot studies, we should look vigilantly for hepatotoxicity, as the first generation thiazolidinediones proved to be toxic for the liver. [source] Evaluation of metaflumizone granular fly bait for management of housefliesMEDICAL AND VETERINARY ENTOMOLOGY, Issue 2 2009A. AHMAD Abstract The housefly, Musca domestica L. (Diptera: Muscidae), is a pest of great veterinary and public health importance. In this study, the efficacy of metaflumizone granular fly bait was assessed on first generation (F1) housefly adults raised from flies collected at a cattle feedlot in Kansas. All bioassays were conducted as choice tests, with flies having ad libitum access to water, granular sugar and bait. A commercial methomyl-based bait (Golden MalrinTM) was used as positive control; no bait (water and granular sugar only) was used as negative control. Fly mortality was recorded on days 2, 7 and 14. The metaflumizone bait was significantly more slow-acting than the methomyl bait (mortality rates after 2 days of exposure were 49.9% and 57.9%, respectively). However, there were no significant differences in cumulative mortality later in the bioassays. Cumulative mortality rates on days 7 and 14 were 96.1% (metaflumizone), 91.4% (methomyl) and 99.0% (metaflumizone), 97.6% (methomyl), respectively. Our results demonstrate that the metaflumizone granular fly bait may be an effective modality for incorporation into management programmes for houseflies in and around livestock production facilities as well as in residential settings. [source] Boom in the development of non-peptidic ,-secretase (BACE1) inhibitors for the treatment of Alzheimer's diseaseMEDICINAL RESEARCH REVIEWS, Issue 2 2009Romano Silvestri Abstract ,-Amyloid cleaving enzyme-1 (BACE1) has become a significant target for the therapy of Alzheimer's disease. After the discovery of the first non-peptidomimetic ,-secretase inhibitors by Takeda Chemicals in 2001, several research teams focused on SAR development of these agents. The non-peptidic BACE1 inhibitors may potentially overcome the classical problems associated with the peptide structure of first generation, such as blood,brain barrier crossing, poor oral bioavailability and susceptibility to P-glycoprotein transport. In the past 6 years a boom in research of non-peptidic BACE1 inhibitors has disseminated findings over hundreds of publications and patents. The rapidly growing literature has been reviewed with particular emphasis on literature of pharmaceutical companies. © 2008 Wiley Periodicals, Inc. Med Res Rev, 29, No. 2, 295,338, 2009 [source] | |||||||||||||||||||||||||||||||||||||