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Selected AbstractsCharacterization and expression of AmphiBMP3,/3b gene in amphioxus Branchiostoma japonicumDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 2 2010Yi Sun Bone morphogenetic proteins (BMPs) are responsible for regulating embryo development and tissue homeostasis beyond osteogenesis. However, the precise biological roles of BMP3 and BMP3b remain obscure to a certain extent. In the present study, we cloned an orthologous gene (AmphiBMP3/3b) from amphioxus (Branchiostoma japonicum) and found its exon/intron organization is highly conserved. Further, in situ hybridization revealed that the gene was strongly expressed in the dorsal neural plate of the embryos. The gene also appeared in Hatschek's left diverticulum, neural tube, preoral ciliated pit and gill slit of larvae, and adult tissues including ovary, neural tube and notochordal sheath. Additionally, real-time quantitative polymerase chain reaction (RTqPCR) analysis revealed that the expression displayed two peaks at gastrula and juvenile stages. These results indicated that AmphiBMP3/3b, a sole orthologue of vertebrate BMP3 and BMP3b, might antagonize ventralizing BMP2 orthologous signaling in embryonic development, play a role in the evolutionary precursors of adenohypophysis, as well as act in female ovary physiology in adult. [source] Transnatal olfactory continuity in the rabbit: Behavioral evidence and short-term consequence of its disruptionDEVELOPMENTAL PSYCHOBIOLOGY, Issue 4 2002Gérard Coureaud Abstract This study investigates the role of prenatal odor learning on postnatal adaptive orientation responses in the newborn rabbit. Preference tests revealed that pups are equally attracted to the odors of placentae and colostrum (Experiments 1,4), suggesting that an odor continuity may exist between the fetal and neonatal environments. To test some predictions derived from this hypothesis, we manipulated the odor of the diet of pregnant-lactating does to control the chemical niches of their perinates. Fetuses exposed in this way to the odor of cumin (C) were selectively attracted as neonates to the odor of pure C (Experiment 6). Prenatal exposure to C also was followed, to a certain extent, by enhanced attraction to C odor in the placenta or colostrum from females which had consumed it (Experiments 5 & 7). Finally, the functional implications of perinatal odor continuity were tested by disrupting it. The odor component of the feto,neonatal transitional environment revealed indeed to affect the ability of certain pups to gain colostrum and milk at the very first sucking opportunities (Experiment 8). © 2002 Wiley Periodicals, Inc. Dev Psychobiol 40: 372,390, 2002. Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/dev.10038 [source] Profile of the climate change in the Kingdom of BahrainENVIRONMETRICS, Issue 8 2003W. E. Alnaser Abstract Long-term meteorological data from the Kingdom of Bahrain (1902 to 2001), along with other data from the Sultanate of Oman and the Kingdom of Saudi Arabia, were used to study the profile and the characteristics of the climate changes in the Kingdom of Bahrain. This article illustrates the possible effects of several factors, such as greenhouse gases (GHG), sunspot number, cosmic ray flux, planet conjunctions, the Earth's magnetic field, as well as volcanic eruption, on the profile of the climate change. In general, we found that the temperature variations, to a certain extent, are associated with the cyclic variations in sunspot number (the 11-year cycle), which in turn affect the pattern of the cosmic ray flux due to the distortion of the interplanetary magnetic field. The latter is believed to influence cloud formation. In addition, the discrepancy in the climate change pattern in Bahrain was also attributed to the combined effect of the high local level of CO2 emissions as well as that of other cooling gases in the region. Copyright © 2003 John Wiley & Sons, Ltd. [source] The biology and ecology of lotic microturbellariansFRESHWATER BIOLOGY, Issue 1 2000Jurek Kolasa Summary 1More than 200 known species of Microturbellaria occur in running waters world-wide but discovery of many more is likely. Their population density varies greatly as a function of substratum, productivity, phenology and hydrology. The density may exceed 7 000 individuals m -2. The number of species in a single small sample may reach 20. 2Many species appear to have microhabitat or stream section specialisation but community patterns are obscured to a certain extent by common and eurytopic species. The specialisation is particularly evident in the smaller, lower-order streams. 3Some of this habitat specialisation is attributable to the ecological origin of species that may include terrestrial, underground, marine and lentic species pools. 4Feeding habits of Microturbellaria range from omnivory to specialised predation. 5Quantitative field studies require extraction and examination of live specimens from samples. Such samples pose transportation and storage problems and must be processed within hours of collection. 6Taxonomy is well resolved for the Northern Hemisphere but is likely to be a major challenge in other parts of the world. In any region, however, new species may demand caution while using current keys to their identification. [source] Environmental signals for seed germination reflect habitat adaptations in four temperate CaryophyllaceaeFUNCTIONAL ECOLOGY, Issue 3 2008F. Vandelook Summary 1Requirements for dormancy break and seed germination are specific for all species and depend chiefly on phylogeny, geographical distribution, habitat preference and life cycle. Studying germination requirements of closely related species with a similar geographic distribution allows one to attribute variation in germination requirements to differences in habitat preference between the species. 2We investigated requirements for dormancy break and the effect of environmental signals on induction of germination in seeds of four closely related Caryophyllaceae species growing in a variety of habitats (Moehringia trinervia, Stellaria holostea, S. nemorum and S. graminea). The species studied depend on disturbances in the vegetation for seed germination and subsequent seedling establishment. 3Seedlings of all four species emerged both in summer and spring. Stellaria nemorum and M. trinervia, both growing in temperate forests, emerged mainly in summer under a closed forest canopy. Seeds of S. graminea, occurring in grasslands, did germinate in summer at an open site, but could not germinate under a closed forest canopy. Seedlings of S. holostea were observed in late summer when buried at an open site or in early spring when sown in a forest patch. 4Seeds of S. holostea and M. trinervia were completely dormant at dispersal in early summer, while germination was low in fresh seeds of S. graminea and S. nemorum. Dormancy was broken, to a certain extent, during all three after-ripening treatments applied (dry storage, cold and warm stratification). 5The effect of three gap-detection signals (light, fluctuating temperatures, nitrates) on germination of fresh and dry stored seeds was tested. Seeds of S. holostea only germinated in response to daily fluctuating temperatures. Although light was the most important signal affecting germination of S. graminea and M. trinervia, we also observed a positive effect of fluctuating temperatures and nitrates on germination. The effect of fluctuating temperatures on germination of S. nemorum was small in both light and dark incubated seeds. Seed germination in this species generally occurred in response to addition of light and nitrates. 6This study on dormancy breaking and germination requirements of the four species enabled us to expose, sometimes subtle, differences in germination requirements. These contrasting germination patterns were related to differences in the species' habitat preferences. [source] Political Representation in Leader Democracy1GOVERNMENT AND OPPOSITION, Issue 3 2005András Körösényi The essay focuses on the neglected problem of democratic politics, i.e. on the role of leadership. Although in democracies public office holders are controlled to a certain extent, leaders still have wide room for political manoeuvre and decide without any ,instruction' of the citizens. Re-working Weber's and Schumpeter's theory, the author aims to build the model of leader democracy. He highlights the major traits of it in a comparison with the deliberative and the aggregative,utilitarian concepts of democratic theory. The theory of leader democracy is applied to the problem of representation, which, in contrast to mechanical mirroring, gains a new, dynamic and qualitative meaning. [source] Taming Madness: Moral Discourse and Allegory in Counter-Reformation SpainHISTORY, Issue 315 2009MARÍA TAUSIET In the early modern period, madness assumed an important role in European thought and to a certain extent replaced the obsession with death which had characterized the preceding centuries. Like death before it, madness was seen as a means of accessing truth, but this was now an incomplete truth full of ambivalence and ambiguity since folly was being reclaimed as a relative form of reason. This article examines how this new vision of madness influenced Spanish thought in the sixteenth and seventeenth centuries. Overall, it can be said that the positive and liberating view of madness, as conveyed by Erasmus, predominated in Spain until the end of the sixteenth century. Thereafter, the spirit of the Counter-Reformation tried gradually to constrain the omnipresent madness, associating it with the most reprehensible of vices, while understanding sanity to be the cultivation of Christian virtues. Despite attempts by a reductionist moral discourse to tame madness, however, it proved to be an unmanageable beast which continued to multiply and display a thousand and one difference faces. [source] Islam in Northern Mozambique: A Historical OverviewHISTORY COMPASS (ELECTRONIC), Issue 7 2010Liazzat Bonate This article is a historical overview of two issues: first, that of the dynamics of Islamic religious transformations from pre-Portuguese era up until the 2000s among Muslims of the contemporary Cabo Delgado, Nampula, and to a certain extent, Niassa provinces. The article argues that historical and geographical proximity of these regions to East African coast, the Comoros and northern Madagascar meant that all these regions shared a common Islamic religious tradition. Accordingly, shifts with regard to religious discourses and practices went in parallel. This situation began changing in the last decade of the colonial era and has continued well into the 2000s, when the so-called Wahhabis, Sunni Muslims educated in the Islamic universities of the Arab world brought religious outlook that differed significantly from the historical local and regional conceptions of Islam. The second question addressed in this article is about relationships between northern Mozambican Muslims and the state. The article argues that after initial confrontations with Muslims in the sixteenth century and up until the last decade of the colonial era, the Portuguese rule pursued no concerted effort in interfering in the internal Muslim religious affairs. Besides, although they occupied and destroyed some of the Swahili settlements, in particular in southern and central Mozambique, other Swahili continued to thrive in northern Mozambique and maintained certain independence from the Portuguese up until the twentieth century. Islam there remained under the control of the ruling Shirazi clans with close political, economic, kinship and religious ties to the Swahili world. By establishing kinship and politico-economic ties with the ruling elites of the mainland in the nineteenth century, these families were also instrumental in expanding Islam into the hinterland. Only at the beginning of the twentieth century, the Portuguese rule took full control of the region as a result of military conquests of the ,effective occupation', and imposed new legal and administrative colonial system, called Indigenato, impacting Muslims of northern Mozambique to a great extent. After the independence in 1975, and especially since 1977, the post-independence Frelimo government adopted militant atheism and socialist Marxism, which was short-lived and was abolished in 1983 owing to popular resistance and especially, because of government's perception that its religious policies were fuelling the opposition groups to take arms and join the civil war. The 1980s and 1990s were marked by an acute rivalry and conflicts between the two emerging national umbrella Islamic organizations, the Islamic Council and the Islamic Congress, each representing largely pro-Sufi and anti-Sufi positions. In the 2000s, these organizations became overshadowed by new and more dynamic organizations, such as Ahl Al-Sunna. [source] Impact of dilute acid pretreatment on the structure of bagasse for bioethanol productionINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 3 2010Wei-Hsin Chen Abstract Dilute acid pretreatment is a commonly used pretreatment method in the course of producing bioethanol from lignocellulosics and the structure variation of the lignocellulosics is highly related to the pretreatment process. To understand the impact of dilute acid pretreatment on the structure of bagasse, four different pretreatment conditions by varying heating time are considered where the bagasse and the pretreated materials are examined using a variety of analysis methods. The obtained results indicate that the thermogravimetric analysis (TGA) is able to provide a useful insight into the recognition of lignocellulosic structure. Specifically, the peak of the TGA of the pretreated materials moves toward the low temperature region, revealing that the lignocellulosic structure is loosened. However, the characteristic of crystal structure of cellulose remains in the pretreated materials. Increasing heating time enhances the pretreatment procedure; as a result, the average particle size of the investigated materials increases with heating time. This swelling behavior may be attributed to the enlarged holes inside the particles in that the surface area decreases with increasing heating time. In addition, when the heating time is increased to a certain extent (e.g. 15,min), some fragments are found at the surface and they tend to peel off from the surface. It follows that the dilute acid pretreatments have a significant effect on the bagasse structure. Copyright © 2009 John Wiley & Sons, Ltd. [source] Robust tracking control for a class of MIMO nonlinear systems with measurable output feedbackINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 1 2008Ya-Jun Pan Abstract This paper proposes a robust output feedback controller for a class of nonlinear systems to track a desired trajectory. Our main goal is to ensure the global input-to-state stability (ISS) property of the tracking error nonlinear dynamics with respect to the unknown structural system uncertainties and external disturbances. Our approach consists of constructing a nonlinear observer to reconstruct the unavailable states, and then designing a discontinuous controller using a back-stepping like design procedure to ensure the ISS property. The observer design is realized through state transformation and there is only one parameter to be determined. Through solving a Hamilton,Jacoby inequality, the nonlinear control law for the first subsystem specifies a nonlinear switching surface. By virtue of nonlinear control for the first subsystem, the resulting sliding manifold in the sliding phase possesses the desired ISS property and to certain extent the optimality. Associated with the new switching surface, the sliding mode control is applied to the second subsystem to accomplish the tracking task. As a result, the tracking error is bounded and the ISS property of the whole system can be ensured while the internal stability is also achieved. Finally, an example is presented to show the effectiveness of the proposed scheme. Copyright © 2007 John Wiley & Sons, Ltd. [source] Weak inhibitors protect cholinesterases from strong inhibitors (paraoxon): in vitro effect of tiaprideJOURNAL OF APPLIED TOXICOLOGY, Issue 6 2005G. A. Petroianu Abstract Weak and reversible inhibitors of cholinesterases, when administered before potent organophosphorus inhibitors (pretreatment), have the ability, to a certain extent, to protect enzymes from inhibition. Such a protective effect was demonstrated in vitro for metoclopramide and ranitidine. The putative mode of protective action of these substances is, when administered in excess, competition for the active site of the enzyme with the more potent organophosphate. The present paper presents results using another benzamide with weak cholinesterase inhibitory properties: tiapride (TIA). The purpose of the study was to quantify in vitro the extent that TIA conferred protection, using paraoxon (POX) as an inhibitor, and to compare the results with existing data obtained using TIA as a protective agent against dichlorvos (DDVP). POX is a highly toxic non-neuropathic organophosphate. While the use of parathion (the inactive prodrug which is metabolically converted to POX) has been restricted in most countries, the organophosphate is still responsible for a large number of accidental or suicidal exposures. DDVP is a moderately toxic, non-neuropathic organophosphate. Red blood cell (RBC) acetylcholinesterase (AChE) activities in whole blood and butyrylcholinesterase (BChE) activities in human plasma were measured photometrically in the presence of different POX and TIA concentrations and the IC50 was calculated. Determinations were repeated in the presence of increasing TIA concentrations. The IC50 of POX increases with the TIA concentration in a linear manner. The protective effect of tiapride on cholinesterase could be of practical relevance in the pretreatment of organophosphate poisoning. It is concluded that in vivo testing of TIA as an organophosphate protective agent is warranted. Copyright © 2005 John Wiley & Sons, Ltd. [source] Gene structure of an antimicrobial peptide from mandarin fish, Siniperca chuatsi (Basilewsky), suggests that moronecidins and pleurocidins belong in one family: the piscidinsJOURNAL OF FISH DISEASES, Issue 6 2007B J Sun Abstract The gene of piscidin, an antimicrobial peptide, has been cloned from the mandarin fish, Siniperca chuatsi. From the first transcription initiation site, the mandarin fish piscidin gene extends 1693 nucleotides to the end of the 3, untranslated region and contains four exons and three introns. A predicted 79-residue prepropeptide consists of three domains: a signal peptide (22 aa), a mature peptide (22 aa) and a C-terminal prodomain (35 aa). The shortage of XQQ motif in the prodomain of mandarin fish piscidin and the similar gene structure between moronecidins (piscidins) and pleurocidins may indicate that they are derived from the same ancestor gene. We thus suggest that piscidin should be used as a terminology for these antimicrobial peptides in the future. The mandarin fish piscidin mRNA was abundant in intestine, spleen, pronephros and kidney analysed by real-time polymerase chain reaction. After stimulation with lipopoly saccharides (LPS), a marked increase in transcripts was observed in most tissues, indicating that piscidin is not only a constitutively expressed molecule, but also has an increased response to bacterial infection. The synthetic, amidated mandarin fish piscidin exhibited different antimicrobial activity against different fish bacterial pathogens, especially against species of Aeromonas, which may to certain extent reflect the pathogenicity of these bacteria. [source] Effect of Sodium Chloride, Acetic Acid, and Enzymes on Carotene Extraction in Carrots (Daucus carota L.)JOURNAL OF FOOD SCIENCE, Issue 2 2005Maria E. Jaramillo-Flores ABSTRACT: Carrot root cores were cut off longitudinally and treated with NaCl (0.6 and 1.2 M) and/or acetic acid (1.33%, 2.67%, and 4%) solutions. The extractability of the carotenes was estimated. Similarly, carrot cores were also treated with some degrading enzymes (carbohydrases, lipases, and proteases) alone or in combination to study the effect of the tissue rupture or the hydrolysis of possible complexes or interactions between carotenes and other components on the carotene extractability. The results showed that acetic acid increased the extractability of ,- and , carotenes up to 99.8% and 94.6%, respectively, at a 4% acid concentration compared with the samples without any treatment. This increase was directly proportional to the acid concentration. An increase in extractability was also observed for NaCl, although the increases were not as high as in the previous case with values of 49% and 41.4% for ,- and ,-carotenes respectively at a 0.6 M concentration. The study of microstructural changes and extractability revealed that the enzymatic treatments could have broken some carotene complexes and interactions and altered the carbohydrate matrix structure, increasing to a certain extent the extractability of carotenes. It can be concluded then that pickling with 4% acetic acid is a good method to increase the extractability of ,- and ,-carotenes. [source] Antioxidative Activity and Safety of 50% Ethanolic Red Bean Extract (Phaseolus radiatus L. var. Aurea)JOURNAL OF FOOD SCIENCE, Issue 1 2003S.-T. Chou ABSTRACT: This study evaluated the antioxidative activities of 50% ethanolic extract from red bean (Phaseolus radiatus L. var. Aurea). The antioxidative activities, including ,,,-diphenyl-,-picryl-hydrazyl (DPPH) radicals scavenging effects, Fe2+ -chelating ability, and reducing power, were studied in vitro. The antioxidative activity was found to increase with the concentration of the extract to a certain extent and then level off as the concentration further increased. Compared with commercial antioxidants, the red bean extract showed less scavenging effect on the DPPH radical and less reducing power than ,-Tocopherol and BHT, but better Fe2+ -chelating ability. No mutagenic effect toward any tester strains was found in the 50% ethanolic extract of red bean. [source] Optimal sampling frequency for volatility forecast models for the Indian stock marketsJOURNAL OF FORECASTING, Issue 1 2009Malay Bhattacharyya Abstract This paper evaluates the performance of conditional variance models using high-frequency data of the National Stock Index (S&P CNX NIFTY) and attempts to determine the optimal sampling frequency for the best daily volatility forecast. A linear combination of the realized volatilities calculated at two different frequencies is used as benchmark to evaluate the volatility forecasting ability of the conditional variance models (GARCH (1, 1)) at different sampling frequencies. From the analysis, it is found that sampling at 30 minutes gives the best forecast for daily volatility. The forecasting ability of these models is deteriorated, however, by the non-normal property of mean adjusted returns, which is an assumption in conditional variance models. Nevertheless, the optimum frequency remained the same even in the case of different models (EGARCH and PARCH) and different error distribution (generalized error distribution, GED) where the error is reduced to a certain extent by incorporating the asymmetric effect on volatility. Our analysis also suggests that GARCH models with GED innovations or EGRACH and PARCH models would give better estimates of volatility with lower forecast error estimates. Copyright © 2008 John Wiley & Sons, Ltd. [source] From forecasting to foresight processes,new participative foresight activities in GermanyJOURNAL OF FORECASTING, Issue 2-3 2003Kerstin Cuhls Abstract The definitions of forecasting vary to a certain extent, but they all have the view into the future in common. The future is unknown, but the broad, general directions can be guessed at and reasonably dealt with. Foresight goes further than forecasting, including aspects of networking and the preparation of decisions concerning the future. This is one reason why, in the 1990s, when foresight focused attention on a national scale in many countries, the wording also changed from forecasting to foresight. Foresight not only looks into the future by using all instruments of futures research, but includes utilizing implementations for the present. What does a result of a futures study mean for the present? Foresight is not planning, but foresight results provide ,information' about the future and are therefore one step in the planning and preparation of decisions. In this paper, some of the differences are described in a straightforward manner and demonstrated in the light of the German foresight process ,Futur'. Copyright © 2003 John Wiley & Sons, Ltd. [source] Prevalence of antibody reaction with cercopithecine herpesvirus 1 antigen in Macaca cyclopis, Macaca fascicularis, and Papio anubis in TaiwanJOURNAL OF MEDICAL PRIMATOLOGY, Issue 6 2007F. Lee Abstract Background and Methods, A total of 284 non-human primate sera were collected between December 2004 and September 2005 and tested by a commercially available dot immunobinding assay for the antibodies to cercopithecine herpesvirus 1, an alphaherpesvirus with high mortality for infected humans. Results, Seropositive rates were 58% among non-human primates from animal shelters and 38% among those from zoos and academic institutes. Positive reactors were found in three species, the Formosan macaque (Macaca cyclopis; 57%), the cynomolgus macaque (Macaca fascicularis; 11%) and the olive baboon (Papio anubis; 68%). Conclusions, Our results showed that natural infection by cercopithecine herpesvirus 1 in Formosan macaques was highly prevalent, and to a certain extent reflected the situation of the wild populations in Taiwan. The findings raised the issues of zoonotic public health and the occupational health of primate workers. High positive rate in olive baboons was also found, although, it cannot be ruled out that the positivity was due to cross-reactivity between cercopithecine herpesvirus 1 and other herpesviruses. [source] Lobby Groups and the Financial Support of Election CampaignsJOURNAL OF PUBLIC ECONOMIC THEORY, Issue 3 2000M. Socorro Puy We study a model of competition between two political parties with policy compromise. There is a special interest group with well-defined preferences on political issues. Voters are of two kinds: impressionable and knowledgeable. The impressionable voters are influenced by the election campaigns. The objective of the parties is to obtain the maximum votes. Parties compete for financial support from a given interest group. Each party proposes a platform in exchange for an amount of campaign funds, and the interest group decides whether to accept or reject each of these proposals. We show that parties' competition resembles, to a certain extent, Bertrand competition. Furthermore, in equilibrium only one party gets funds from the interest group. This result differs from the one obtained in a similar model by Grossman and Helpman in which, in equilibrium, both parties are financed by the interest group. This difference arises because Grossman and Helpman assume that it is the interest group who makes the proposals to the political parties. [source] Alcohol in Moderation, Cardioprotection, and Neuroprotection: Epidemiological Considerations and Mechanistic StudiesALCOHOLISM, Issue 2 2009Michael A. Collins In contrast to many years of important research and clinical attention to the pathological effects of alcohol (ethanol) abuse, the past several decades have seen the publication of a number of peer-reviewed studies indicating the beneficial effects of light-moderate, nonbinge consumption of varied alcoholic beverages, as well as experimental demonstrations that moderate alcohol exposure can initiate typically cytoprotective mechanisms. A considerable body of epidemiology associates moderate alcohol consumption with significantly reduced risks of coronary heart disease and, albeit currently a less robust relationship, cerebrovascular (ischemic) stroke. Experimental studies with experimental rodent models and cultures (cardiac myocytes, endothelial cells) indicate that moderate alcohol exposure can promote anti-inflammatory processes involving adenosine receptors, protein kinase C (PKC), nitric oxide synthase, heat shock proteins, and others which could underlie cardioprotection. Also, brain functional comparisons between older moderate alcohol consumers and nondrinkers have received more recent epidemiological study. In over half of nearly 45 reports since the early 1990s, significantly reduced risks of cognitive loss or dementia in moderate, nonbinge consumers of alcohol (wine, beer, liquor) have been observed, whereas increased risk has been seen only in a few studies. Physiological explanations for the apparent CNS benefits of moderate consumption have invoked alcohol's cardiovascular and/or hematological effects, but there is also experimental evidence that moderate alcohol levels can exert direct "neuroprotective" actions,pertinent are several studies in vivo and rat brain organotypic cultures, in which antecedent or preconditioning exposure to moderate alcohol neuroprotects against ischemia, endotoxin, ,-amyloid, a toxic protein intimately associated with Alzheimer's, or gp120, the neuroinflammatory HIV-1 envelope protein. The alcohol-dependent neuroprotected state appears linked to activation of signal transduction processes potentially involving reactive oxygen species, several key protein kinases, and increased heat shock proteins. Thus to a certain extent, moderate alcohol exposure appears to trigger analogous mild stress-associated, anti-inflammatory mechanisms in the heart, vasculature, and brain that tend to promote cellular survival pathways. [source] System thinking skills at the elementary school levelJOURNAL OF RESEARCH IN SCIENCE TEACHING, Issue 5 2010Orit Ben-Zvi Assaraf Abstract This study deals with the development of system thinking skills at the elementary school level. It addresses the question of whether elementary school students can deal with complex systems. The sample included 40 4th grade students from one school in a small town in Israel. The students studied an inquiry-based earth systems curriculum that focuses on the hydro-cycle. The program involved lab simulations and experiments, direct interaction with components and processes of the water cycle in the outdoor learning environment and knowledge integration activities. Despite the students' minimal initial system thinking abilities, most of them made significant progress with their ability to analyze the hydrological earth system to its components and processes. As a result, they recognized interconnections between components of a system. Some of the students reached higher system thinking abilities, such as identifying interrelationships among several earth systems and identifying hidden parts of the hydrological system. The direct contact with real phenomena and processes in small scale scenarios enabled these students to create a concrete local water cycle, which could later be expanded into large scale abstract global cycles. The incorporation of outdoor inquiry-based learning with lab inquiry-based activities and knowledge integration assignments contributed to the 4th grade students' capacity to develop basic system thinking abilities at their young age. This suggests that although system thinking is regarded as a high order thinking skill, it can be developed to a certain extent in elementary school. With a proper long-term curriculum, these abilities can serve as the basis for the development of higher stages of system thinking at the junior,high/middle school level. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 47: 540,563, 2010 [source] Making sex: law's narratives of sex, gender and identityLEGAL STUDIES, Issue 1 2003Laura Grenfell From the 1970 decision of Corbett, onwards, legal narratives established two modes of categorising complex social identi5 in relation to sex and gender. These narratives responded to complex identity questions by attempting to simplify identity by limiting it to biological factors or anatomical and psychological factors. I demonstrate that the law's struggle to ,make' sex is reflected to a certain extent by feminism's trajectory, in that feminisms have also attempted to grapple with these complex questions, and often opted for the same simple solutions to the problem of understanding gender, sex and identity. The aim of this paper is to show that some strands of feminist theory, specifically post-structuralist feminist theory, can produce a more progressive and constructive approach to determining sex in their ability to illuminate the complexities of identity. In particular, my aim is to urge those courts that ,make' sex to consider these complexities and the implications that flow from placing transgender people into rigid arid narrow categories. [source] Palaeontologic and biogeochemical characterization of the Cyrtograptus lundgreni event in the black shales of eastern Mid-Sardinia, ItalyLETHAIA, Issue 2 2006Paola Pittau A succession of biotic and geochemical changes that occurred during the Cyrtograptus lundgreni Event (Late Wenlock) have been recorded from the ,pelagic' black-shales in the Goni section, eastern mid-Sardinia, Italy. The studied interval encompasses the Cyrtograptus rigidus to Pristiograptus dubius-Gothograptus nassa zones. The fossil association includes graptolites, chitinozoans and microplankton i.e. probable linings of agglutinated foraminifera and radiolaria capsular membranes. Analysis of the chitinozoan distribution revealed a succession of several chitinozoan associations with low species diversity and dominated by opportunistic species. Three chitinozoan faunal turnovers and three extinction events have been recorded. Two of them coincide with graptolite extinctions whereas one probably is of local significance. Disappearance of the chitinozoan and microplankton associations occurred during four consecutive graptolite zones. Geochemical data (trace elements analysis) showed significantly higher (up to c. 100%) values for Co and Cd in the sedimentary organic matter (SOM) than in the whole rock samples. Possible relationships between peaks of metal enrichment, the major faunal changes among chitinozoans, extinction events among chitinozoans and graptolites and, to a certain extent, oceanic events may be inferred. The first extinction datum is older that those occurring in Gotland, Sweden and Thüringen, Germany and is so far considered to be of local significance. The second extinction datum of Sardinia can be matched with Datum 1 of Gotland and Thüringen. A close correlation between the third extinction datum of Sardinia and Datum 2 of Thüringen and Gotland reinforces the importance of these events at global scale. [source] Time-Resolved Synchrotron SAXS Observations on Sheared Syndiotactic Poly(propylene) Crystallization ProcessMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 16 2008Huiying Wen Abstract The in situ crystallization kinetics of syndiotactic poly(propylene) (sPP) has been investigated by synchrotron small-angle X-ray scattering (SAXS). The structure evolutions during the isothermal crystallization of sPP with different shear rates have been observed. The results show that shear accelerates the process of crystallization kinetics. Even under low shear rate, the lamellae can be distinctly oriented. In contrast, the lamellar parameters such as the long period, lamellar thickness, and the scattering invariant Q can change obviously only under high shear rate. A mesomorphic structure proposed by Strobl is adopted to elucidate the differences of shear effects with low and high shear rates. Based on all the analysis we are convinced that a relatively stable mesomorphic structure forms before shear is composed and the shear effects on the mesophase will be retained to a certain extent until crystallization is finished. [source] Killing for the state: the darkest side of American nursingNURSING INQUIRY, Issue 1 2003Dave Holmes The aim of this article is to bring to the attention of the international nursing community the discrepancy between a pervasive ,caring' nursing discourse and a most unethical nursing practice in the United States. In this article, we present a duality: the conflict in American prisons between nursing ethics and the killing machinery. The US penal system is a setting in which trained healthcare personnel practice the extermination of life. We look upon the sanitization of deathwork as an application of healthcare professionals' skills and knowledge and their appropriation by the state to serve its ends. A review of the states' death penalty statutes shows that healthcare workers are involved in the capital punishment process and shielded by American laws (and to a certain extent by professional boards through their inaction). We also argue that the law's language often masks that involvement; and explain how states further that duplicity behind legal formalisms. In considering the important role healthcare providers, namely nurses and physicians, play in administering death to the condemned, we assert that nurses and physicians are part of the states' penal machinery in America. Nurses and physicians (as carriers of scientific knowledge, and also as agents of care) are intrinsic to the American killing enterprise. Healthcare professionals who take part in execution protocols are state functionaries who approach the condemned body as angels of death: they constitute an extension of the state which exercises its sovereign power over captive prisoners. [source] Finite element analysis of vent/hand hole designs for corrugated fibreboard boxesPACKAGING TECHNOLOGY AND SCIENCE, Issue 1 2007Jongkoo Han Abstract Corrugated fibreboard is an economical and efficient material for fabricating shipping containers that are widely used for the distribution, transportation and storage of goods. Corrugated fibreboard is usually considered to be an orthotropic material because the principal fibre directions, machine direction (MD) and cross-machine direction (CD), are identical to the fibres in paperboard, which has apparent directional property differences. The purpose of this study is to investigate the principal design parameters of ventilation holes and hand holes in the faces of the shipping container, (corrugated fibreboard boxes), using finite element analysis (FEA). Various designs of ventilation holes were studied with respect to stress distribution and stress level. It was found that the appropriate pattern and location of the ventilation holes were vertical oblong-shaped and symmetrically positioned within a certain extent of distance to the right and left from the centre of the front and rear faces of the boxes. On the other hand, the appropriate location and pattern of the hand holes were a short distance from the centre to the top of the boxes on both side faces. The appropriate pattern was a modified shape, such as the radius of curvature of both sides in horizontal oblong. The pattern and location of both the ventilation holes and the hand holes determined by the FEA simulation generally agreed well with laboratory experimental results. The decrease in compression strength of the box could be minimized with identical area of the ventilation holes if the length of the major axis of the ventilation hole is less than 1/4 of the depth of the box and the ratio of the minor axis to the major axis is 1/3.5,1/2.5, provided that even-numbered holes are located symmetrically. Copyright © 2006 John Wiley & son, Ltd. [source] Climatic and geomorphic factors affecting contemporary (1950,2004) activity of retrogressive thaw slumps on the Aklavik Plateau, Richardson Mountains, NWT, CanadaPERMAFROST AND PERIGLACIAL PROCESSES, Issue 1 2010Denis Lacelle Abstract The climatic and geomorphic factors affecting retrogressive thaw slump initiation and activity on the Aklavik Plateau (Richardson Mountains, NWT) were examined using historical air photographs over a 54-year period (1950 to 2004). In this region, thaw slumps include a near-vertical headwall, a floor of low gradient (2,10°) and a steeply sloping evacuation channel (15,25°) that connects the floor of the thaw slumps to Willow River located 60,150,m below. All thaw slumps on the Aklavik Plateau are located within the glacial limit of the Laurentide Ice Sheet and the majority developed on the western side of the valley on gently sloping terrain. Aerial photographic analysis showed an increase in thaw slump initiation from 0.35 new thaw slump yr,1 over the 1954,71 period to 0.68 new thaw slump yr,1 over the 1985,2004 period. This increase follows the pattern of the 10-year running mean summer air temperature record over the 1950,2004 period. However, the total number of active mature thaw slumps on the Aklavik Plateau decreased from a maximum of 46 in 1950 to a minimum of 24 observed in 2004, which follows, to a certain extent, the 10-year running average of rainfall. Both these trends may relate to the influence of climate on the erosional processes that are thought to initiate thaw slumps and keep them active in regions of highlands. Copyright © 2009 John Wiley & Sons, Ltd. and Her Majesty the Queen in right of Canada. [source] Highly defined and ordered top-openings in TiO2 nanotube arraysPHYSICA STATUS SOLIDI - RAPID RESEARCH LETTERS, Issue 7 2010Sergiu P. Albu Abstract We report a very simple and novel approach to produce anodic TiO2 nanotube arrays with highly defined and ordered tube openings. It is based on carrying out anodization through a slowly soluble photoresist coating. This eliminates the formation of undesired initiation layers on the tube tops and protects them to a certain extent from etching by the electrolyte. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Formation of porous layers on InSb(100) by anodizationPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 1 2003P. Schmuki Abstract The present work deals with anodization processes of n-type InSb(100). Preferential etching of InSb can be electrochemically initiated in HCl HBr and HF solutions. Except for etch features also the formation of porous layers can be observed. The resulting features were characterized by SEM and AES measurements. Due to the narrow bandgap of the material the results of the anodization process are neither sensitive to illumination of the n-type material nor to the doping level. The morphology of the attack depends strongly on the electrochemical conditions and the type of halogen acid present in the electrolyte. In HCl and HBr a black porous layer can be formed that is likely to consist to a certain extent of an antimony-oxo-chloride or antimony-oxo-bromide. In HF, however, polarization under a wide range of electrochemical conditions leads to a uniform etching of the InSb surface. [source] Free IAA in stigmas and styles during pollen germination and pollen tube growth of Nicotiana tabacumPHYSIOLOGIA PLANTARUM, Issue 1 2008Dan Chen Although many studies have emphasized the importance of auxin in plant growth and development, the thorough understanding of its effect on pollen,pistil interactions is largely unknown. In this study, we investigated the role of free IAA in pollen,pistil interactions during pollen germination and tube growth in Nicotiana tabacum L. through using histo and subcellular immunolocalization with auxin monoclonal antibodies, quantification by HPLC and ELISA together with GUS staining in DR5::GUS -transformed plants. The results showed that free IAA in unpollinated styles was higher in the apical part and basal part than in the middle part, and it was more abundant in the transmitting tissue (TT). At the stage of pollen germination, IAA reached its highest content in the stigma and was mainly distributed in TT. After the pollen tubes entered the styles, the signal increased in the part where pollen tubes would enter and then rapidly declined in the part where pollen tubes had penetrated. Subcellular localization confirmed the presence of IAA in TT cells of stigmas and styles. Accordingly, a schematic diagram summarizes the changing pattern of free IAA level during flowering, pollination and pollen tube growth. Furthermore, we presented evidence that low concentration of exogenous IAA could, to a certain extent, facilitate in vitro pollen tube growth. These results suggest that IAA may be directly or indirectly involved in the pollen,pistil interactions. Additionally, some improvements of the IAA immunolocalization technique were made. [source] Effect of clay on the morphology of binary blends of polyamide 6 with high density polyethylene and HDPE- graft -acrylic acidPOLYMER ENGINEERING & SCIENCE, Issue 5 2007Zhengping Fang Polyamide 6 (PA6)/HDPE/organo-bentonite (Oclay) and PA6/HDPE- grafted -acrylic acid (PEAA)/Oclay nanocomposites were prepared via melt compounding. The influence of Oclay on the morphology of composites was investigated. Scanning electron microscopy results revealed the size of the dispersed HDPE, and PEAA phase decreased with increasing Oclay content. Transmission electron microscopy and X-ray diffraction results revealed that the Oclay was predominately intercalated with some evidence of partial exfoliation. The majority of Oclay platelets were concentrated in the PA6 phase and in the interfacial region between PA6 and HDPE (PEAA). The Oclay platelets played the role of coupling species between the two polymers, increasing the interaction of the two phases in certain extent. These results were proved by FTIR and positron annihilation lifetime spectroscopy. Consequently, apparent emulsifying effect was induced. A schematic mechanism of the apparent compatibilization effect was presented. POLYM. ENG. SCI., 47:551,559, 2007. © 2007 Society of Plastics Engineers. [source] | |||||||||||||||||||||||||||||||||||||