bluuebunny/crossref_metadata_2025 huggingface dataset:
Prediction of e-Learning Efficiency by Neural Networks
Authors: Halachev Petar
Published: March 2013

A model for prediction of the outcome indicators of e-Learning, based on Balanced ScoreCard (BSC) by Neural Networks (NN) is proposed. In the development of NN models the problem of a small sample size of the data arises. In order to reduce the number of variables and increase the examples of the training sample, preprocessing of the data with the help of the methods Interpolation and Principal Component Analysis (PCA) is performed. A method for optimizing the structure of the neural network is applied over linear and nonlinear neural network architectures. The highest accuracy of prognosis is obtained applying the method of Optimal Brain Damage (OBD) over the nonlinear neural network. The efficiency and applicability of the method suggested is proved by numerical experiments on the basis of real data.
The influence of harvest maturity and basic macroelement content in fruit on the incidence of diseases and disorders after storage of the ‘Ligol’ apple cultivar
Authors: Łysiak Grzegorz
Published: March 2013

Research was carried out during the 1999-2007 growing and storage season using ‘Ligol’ apples from trees grafted on M.26, and fertilised in accordance with recommendations for commercial orchards. The approximate optimum harvest date was determined mainly on the basis of starch index measurements and Streif index calculations, evaluated 7-8 times every 4-5 days each year. In addition to samples collected to determine OHD each year, there were four harvests of fruit intended for storage. The apples were stored in a cold storage room at 1-2°C and RH of around 90% for about five months. Following a storage period lasting the same number of days for each harvest, the quality of fruits was examined and the correlation between the concentration of minerals in apples and all fungal diseases and physiological disorders was calculated. In years with high precipitation in the period preceding the harvest, the share of fruits affected by fungal diseases and physiological disorders after storage depended more on weather conditions prevailing in the growing season than on the harvest date. The incidence of bitter pit increased with the number of days preceding OHD. Other recorded losses were caused by internal breakdown and superficial scald, but they were small and did not seem significant for ‘Ligol’ apples. Each characteristic mineral concentration in the fruit at harvest (N, P, K, Ca and Mg) was correlated with the incidence of physiological disorders and/or fungal diseases. The incidence of bitter pit and lenticel blotch pit and the sum of physiological disorders increased along with the increase in nitrogen concentration. The feature that best predicted the storability of ‘Ligol’ was the K/Ca ratio.
The influence of rock raw materials comminution in various crushers and crushing stages on the quality of mineral aggregates
Authors: Gawenda Tomasz
Published: March 2013

Streszczenie

Artykuł porusza problematykę optymalnego wykorzystania różnych kruszarek udarowych i szczękowych w różnych stadiach rozdrabniania układów technologicznych w celu uzyskania właściwej jakości kruszyw. We wstępie omówiono występujące w kruszarkach elementarne działania sił kruszących i ich związek z efektami rozdrabniania. Zwrócono uwagę, że celem artykułu jest zarysowanie metodyki badañ przy różnych kombinacjach układów technologicznych (rys. 1) oraz rezultatów rozdrabniania (rys. 5-9, tab. 1, 2).

Objaśniono przyjęty plan badañ, który składał się z trzech etapów. Pierwsza część badañ dotyczyła warunków przemysłowego procesu produkcji kruszyw w austriackiej żwirowni Viecht, czyli pobrania prób z kruszarek udarowych listwowych, ich analizę i przygotowanie do dalszych badañ. Druga część obejmowała kruszenie surowca oraz analizy produktów z kruszarki szczękowej oraz unikatowej kruszarki udarowej (laboratoria firmy SBM Mineral Processing w Laakirchen), natomiast trzecia część obejmowała kruszenie w kruszarce szczękowej oraz mielenie w młynku kulowym Bonda (laboratoria AGH w Krakowie). Trójczęściowy plan badañ dał możliwość realizacji układów trój- i czerostadialnych (rozdz. 2, rys. 1).

Do oceny efektów rozdrabniania w kolejnych stadiach kruszenia wykorzystano wskaźniki zawartości ziaren nieforemnych (wskaśnik płaskości), udział pyłów <1 mm w produktach, stopnie rozdrobnienia oraz zużycie energii, natomiast do oceny efektów rozdrabniania w ostatnim stadium rozdrabniania zastosowano wskaźnik udziału pyłu < 1 mm uzyskanego w mieleniu kruszywa w młynku Bonda przy 100 obrotach (rozdz. 3, rys. 5-9, tab. 1, 2).

W podsumowującym rozdziale czwartym zwrócono uwagę na zalety oraz wady stosowania różnych kruszarek w różnych stadiach rozdrabniania. Stwierdzono, że dla produkcji kruszyw żwirowych gruboziarnistych wykorzystywanych w budownictwie czy drogownictwie najkorzystniejsze byłyby układy wielostadialne z kruszarkami udarowymi, ponieważ w nich uzyskuje się ziarna o wysokiej kubiczności i zwiększonej odporności na rozdrabnianie, natomiast kruszarki szczękowe w takim układzie można byłoby spożytkować w celu przygotowywania półproduktów do procesu mielenia przy produkcji kruszyw drobnoziarnistych (mączek).
Study of physico-chemical and mechanical characteristics of consolidated and unconsolidated cemented paste backfills
Authors: Yilmaz Erol , Belem Tikou , Benzaazoua Mostafa
Published: March 2013

Streszczenie

W ostatnich latach obserwuje się, że wydajność i jakość próbek zawiesin nasyconych cementem (CPB - Cement Paste Backfill) in situ są stale niższe niż tych samych próbek przygotowanych w plastikowych formach w laboratorium. Może to wynikać z braku w laboratorium skutecznego narzędzia mogącego naśladować zawiesiny in situ, warunki ich utwardzania jak również rozmiary i geometrię próbek. W celu wypełnienia tej luki, w la­boratorium opracowano nowe narzędzie o nazwie CUAPS (Curing Under Applied Pressure System), wytworzone i wykorzystane do zbadania wpływu ciśnienia na podstawie skutecznego nacisku na właściwości fizykochemiczne i mechaniczne CPB, jak również próbek otrzymanych z plastikowych form. Badania porównawcze przeprowa­dzono zarówno dla próbek CUAPS jak i próbek otrzymanych w laboratorium, zawierających lepiszcza (cementu) 3,45 i 7% wag. po 7, 14 i 28 dniach utwardzania. Wyniki wskazują, że wydajność próbek konsolidowanych CUAPS są zawsze bardziej prawdziwe (realistyczne) niż próbek otrzymanych w laboratorium, głównie z powodu odprowadzania wody w wyniku konsolidacji. Ostatecznie metoda CUAPS powoduje korzystny wpływ na utwar­dzenie CPB dzięki zawartości wody (separacja wody od świeżej zawiesiny odpadów z cementu) i połączeniu części wody zasobowej z zawiesiną w zrobach.
Thermal synthesis of black coal fly ash and gibbsite
Authors: Kusnierova Maria , Prascakova Maria , Matysek Dalibor , Cablik Vladimir , Fecko Peter , Jarosiñski Andrzej
Published: March 2013

Streszczenie

Mulit jest minerałem glinokrzemianowym o wyjątkowych właściwościach i odgrywa istotną rolę w wytwa­rzaniu ogniotrwałych wyrobów. W przyrodzie występuje bardzo rzadko i z tych też względów jest otrzymywany na drodze syntezy z naturalnych pierwotnych surowców (silmanit, andaluzyt, cyjanit), ale jego głównym źródłem jest kaolinit.

Proces mulityzacji jest związany z przemianą minerałów glinu w mulit. Efektywność przemiany związków glinu w mulit jest zawsze mniejsza w stosunku do teoretycznej zawartości Al2O3 w tworzywie. Proces przemiany zależy od obecności mineralizatorów, temperatury, czasu wypału itp.

Celem tej pracy była ocena możliwości wykorzystania odpadów energetycznych zawierających takie skład­niki jak Al i Si. Do skorygowania składu stosowano glin w postaci gibbsytu. Przebadano wpływ różnych stosunków popiołu lotnego i gibbsytu jak i wpływ temperatury przemiany na skład mineralny (fazowy) przygo­towanych kompozytów typu mulitu.
Chromophore Poling in Thin Films of Organic Glasses. 3. Setup for Corona Triode Discharge / Hromoforu Polarizēšana Plānās Organisko Stiklu Kārtiņās 3. Koronas Izlādes Triodes Ierīce
Authors: Vilitis O. , Titavs E. , Nitiss E. , Rutkis M.
Published: March 2013

The corona discharge is described focusing on the advantages of corona triode techniques for the direct current (DC) positive poling of optical polymers. The proposed experimental setup allows the corona poling of nonlinear optical (NLO) polymers in the modes of DC constant current (the lowest 1nA) and of the fixed corona-grid voltage, making it possible to carry out the corona-onset poling at elevated temperature (COPET) up to 200 oC. The setup also provides a wide range of the corona discharge voltage (3 kV - 15 kV), variable reciprocal distance of electrodes as well as the possibility to choose from different types of the corona electrode (needle, multi-needle, wire, etc.). By keeping the corona-to-grid voltage constant, a stable corona discharge at electrode is attained. The grid voltage can be varied in the range from 0 to 3kV. The corona poling area on the sample surface is pre-defined by placing ring spacers above it. The setup is completely computerized, allowing both control and monitoring of the corona discharge, which promotes research into the process of charging NLO polymer samples and selection of the optimal poling mode. Using the voltage-current characteristics and the second-harmonic measurements of a poled polymer we also demonstrate the influence of the setup parameters on the efficiency of poling the thin film NLO polymers.
SDPSK-Specific Demodulation Method for the Nanortu Field-Programmable Gate Array / SDPSK-Specifiska Demodulācijas Metode Nanortutm Programmētajām Loģiskajām Integrācijas Shēmām
Authors: Skorodumovs A.
Published: March 2013

The software-defined radio (SDR) solutions inpart flexibility to the satellite applications when the devices are physically inaccessible after the launch. The nanoRTU FPGA-based controller (AAC Microtec) may be programmed to serve as a software-defined differential phase shift keying (SDPSK) modem backend to be used in satellites for communication with the Earth. The modem consists of two units - a modulator and a demodulator. A fully functional symmetric SDPSK modulator for nanoRTU FPGA has already been implemented. The next step of the modem implementation is the development of demodulator. In order to implement such facilities, the existing demodulation techniques should be reviewed in order to propose the appropriate method in which the demodulator would be capable of demodulating a signal, and, at the same time, would be resource-efficient. The author describes a valid method of specific SDPSK signal demodulation for the nanoRTU FPGA.
Photographs and Film Recordings as Valuable Documents in Sports History Research
Authors: Sarje Ajno
Published: March 2013

Photographs and film recordings have not been commonly used as source material in sports history research. However, every moment and every movement captured in photographs tell us things that researchers could have seen if they had been on the spot when the picture was taken. I suggest that photos and films can be read in the same way as any sign systems, such as writing or maps. The points of departure for my analysis of movement in photographs and film recordings are kinesthetic empathy and the idea that the meanings of most body movements are established to the extent that they are part of our cultural heritage and contain signs and symbols we can relate to. Furthermore, observations made from these documents can be analyzed with the help of theories from other research fields. Using the methods of dance research, such as Rudolf Laban’s movement analysis, Janet Adshead’s dance performance analysis, Marcel Mauss’s habitus concept, and John Martin’s dance analysis, styles, movement languages, and conventions of exercise and sport in photos and films can be identified. In addition, in accordance with photographic research by Roland Barthes, I will reflect on the fringe conditions of the use of photographs as research material, the kind of opportunities they offer, and the kind of limitations they set for the researcher.
Effects of plant phenology and vertical height on accuracy of radio‐telemetry locations
Authors: Grovenburg Troy W. , Jacques Christopher N. , Klaver Robert W. , DePerno Christopher S. , Lehman Chad P. , Brinkman Todd J. , Robling Kevin A. , Rupp Susan P. , Jenks Jonathan A.
Published: March 2013

The use of very high frequency (VHF) radio‐telemetry remains wide‐spread in studies of wildlife ecology and management. However, few studies have evaluated the influence of vegetative obstruction on accuracy in differing habitats with varying transmitter types and heights. Using adult and fawn collars at varying heights above the ground (0, 33, 66 and 100 cm) to simulate activities (bedded, feeding and standing) and ages (neonate, juvenile and adult) of deer Odocoileus spp., we collected 5,767 bearings and estimated 1,424 locations (28‐30 for each of 48 subsamples) in three habitat types (pasture, grassland and forest), during two stages of vegetative growth (spring and late summer). Bearing error was approximately twice as large at a distance of 900 m for fawn (9.9°) than for adult deer collars (4.9°). Of 12 models developed to explain the variation in location error, the analysis of covariance model (HT∗D + C∗D + HT∗TBA + C∗TBA) containing interactions of height of collar above ground (HT), collar type (C), vertical height of understory vegetation (D) and tree basal area (TBA) was the best model (wi = 0.92) and explained ∼ 71% of the variation in location error. Location error was greater for both collar types at 0 and 33 cm above the ground compared to 66 and 100 cm above the ground; however, location error was less for adult than fawn collars. Vegetation metrics influenced location error, which increased with greater vertical height of understory vegetation and tree basal area. Further, interaction of vegetation metrics and categorical variables indicated significant effects on location error. Our results indicate that researchers need to consider study objectives, life history of the study animal, signal strength of collar (collar type), distance from transmitter to receiver, topographical changes in elevation, habitat composition and season when designing telemetry protocols. Bearing distances in forested habitat should be decreased (approximately 23% in our study) compared to bearing distances in open habitat to maintain a consistent bearing error across habitats. Additionally, we believe that field biologists monitoring neonate ungulates for habitat selection should rely on visual locations rather than using VHF‐collars and triangulation.
Factors affecting the elicitation of vocal responses from coyotes Canis latrans
Authors: Petroelje Tyler R. , Belant Jerrold L. , Beyer Dean E.
Published: March 2013

Long‐distance vocalizations by canids play an important role in communication among individuals, and researchers have elicited these vocalizations to estimate canid occurrence and relative abundance. We evaluated the efficacy of broadcasted coyote Canis latrans group‐yip calls and gray wolf C. lupus lone howls to elicit vocal responses from 18 GPS‐collared coyotes on 144 occasions in Michigan's Upper Peninsula during August‐September 2009 and June‐September 2010‐2011. We evaluated coyote responses to each call type using mixed‐effects logistic regression models with time (month), residency status (resident or transient), presence in wolf territory, sex, distance, movement and call type as fixed effects hypothesized to influence coyote vocal response rates. The individual coyote and year were included as random effects. Overall, call type, sex and presence of wolf territory did not affect coyote response rates; however, coyotes did not respond to wolf calls broadcasted at distances of > 2.0 km. Resident coyotes were three times more likely to respond than transients and the greatest overall response rates occurred in August. We conclude that eliciting coyote vocalizations where wolves are present will not bias responses, and we recommend eliciting coyote vocalizations using recorded coyote group‐yip howls during July‐September to estimate the species' presence or density.
Race, Ethnicity, and College Success
Authors: Flores Stella M. , Park Toby J
Published: March 2013

The minority-serving institution (MSI) sector has grown considerably since the 1980s, yet we have less empirical information about what currently influences students to enroll in and complete college at these institutions in comparison to their non-MSI counterparts. We evaluate student postsecondary outcomes by race and ethnicity in Texas’s large MSI sector utilizing state administrative data from 1997 to 2008. At the enrollment stage, we find that race is an important predictor of college enrollment, despite controlling for detailed precollege characteristics. At the college-completion stage, however, the effect of race is largely no longer present after accounting for institutional characteristics, including attending an MSI. That is, in most of the cohorts examined, Hispanic and Black students who initially enroll in a four-year institution showed no difference from their White peers in six-year graduation outcomes. In sum, Hispanic-serving institutions are particularly critical locations for Hispanics while the non-MSI community colleges emerge as key institutions for Black students, signaling important implications for how historically Black colleges and universities might address recruitment and transfer strategies. Implications for practitioners and researchers are offered.
Potential Nutritional Benefits of Current Citrus Consumption
Authors: Turner Tami , Burri Betty
Published: March 2013

Citrus contains nutrients and phytochemicals that may be beneficial for health. We collected citrus production and consumption data and estimated the amount of these compounds that are consumed. We then compared the amounts of citrus and citrus-derived compounds used in studies that suggest a health benefit to the amounts typically found in citrus. Data is scarce, but suggests that citrus consumption might improve indices of antioxidant status, and possibly cardiovascular health and insulin sensitivity.
Animal Experiments in Biomedical Research: A Historical Perspective
Authors: Franco Nuno
Published: March 2013

The use of non-human animals in biomedical research has given important contributions to the medical progress achieved in our day, but it has also been a cause of heated public, scientific and philosophical discussion for hundreds of years. This review, with a mainly European outlook, addresses the history of animal use in biomedical research, some of its main protagonists and antagonists, and its effect on society from Antiquity to the present day, while providing a historical context with which to understand how we have arrived at the current paradigm regarding the ethical treatment of animals in research.
Characterizing a New Surface-Based Shortwave Cloud Retrieval Technique, Based on Transmitted Radiance for Soil and Vegetated Surface Types
Authors: Coddington Odele , Pilewskie Peter , Schmidt K. , McBride Patrick , Vukicevic Tomislava
Published: March 2013

This paper presents an approach using the GEneralized Nonlinear Retrieval Analysis (GENRA) tool and general inverse theory diagnostics including the maximum likelihood solution and the Shannon information content to investigate the performance of a new spectral technique for the retrieval of cloud optical properties from surface based transmittance measurements. The cumulative retrieval information over broad ranges in cloud optical thickness (τ), droplet effective radius (re), and overhead sun angles is quantified under two conditions known to impact transmitted radiation; the variability in land surface albedo and atmospheric water vapor content. Our conclusions are: (1) the retrieved cloud properties are more sensitive to the natural variability in land surface albedo than to water vapor content; (2) the new spectral technique is more accurate (but still imprecise) than a standard approach, in particular for τ between 5 and 60 and re less than approximately 20 μm; and (3) the retrieved cloud properties are dependent on sun angle for clouds of from 5 to 10 and re < 10 μm, with maximum sensitivity obtained for an overhead sun.
Climate Change and Intertidal Wetlands
Authors: Ross Pauline , Adam Paul
Published: March 2013

Intertidal wetlands are recognised for the provision of a range of valued ecosystem services. The two major categories of intertidal wetlands discussed in this contribution are saltmarshes and mangrove forests. Intertidal wetlands are under threat from a range of anthropogenic causes, some site-specific, others acting globally. Globally acting factors include climate change and its driving cause—the increasing atmospheric concentrations of greenhouse gases. One direct consequence of climate change will be global sea level rise due to thermal expansion of the oceans, and, in the longer term, the melting of ice caps and glaciers. The relative sea level rise experienced at any one locality will be affected by a range of factors, as will the response of intertidal wetlands to the change in sea level. If relative sea level is rising and sedimentation within intertidal wetlands does not keep pace, then there will be loss of intertidal wetlands from the seaward edge, with survival of the ecosystems only possible if they can retreat inland. When retreat is not possible, the wetland area will decline in response to the “squeeze” experienced. Any changes to intertidal wetland vegetation, as a consequence of climate change, will have flow on effects to biota, while changes to biota will affect intertidal vegetation. Wetland biota may respond to climate change by shifting in distribution and abundance landward, evolving or becoming extinct. In addition, impacts from ocean acidification and warming are predicted to affect the fertilisation, larval development, growth and survival of intertidal wetland biota including macroinvertebrates, such as molluscs and crabs, and vertebrates such as fish and potentially birds. The capacity of organisms to move and adapt will depend on their life history characteristics, phenotypic plasticity, genetic variability, inheritability of adaptive characteristics, and the predicted rates of environmental change.
NADPH Oxidase and Angiogenesis Following Endothelin-1 Induced Stroke in Rats: Role for Nox2 in Brain Repair
Authors: Taylor Caroline , Weston Robert , Dusting Gregory , Roulston Carli
Published: March 2013

NADPH oxidases contribute to brain injury, yet they may also have a role in brain repair, particularly in vascular signaling and angiogenesis. This study determined the temporal and spatial profile of NADPH oxidase subunit expression/activity concurrently with angiogenesis in the brain following transient ischemic stroke induced by prolonged constriction of the middle cerebral artery by perivascular injection of endothelin-1 in conscious Hooded Wistar rats (n = 47). VEGF mRNA expression was increased in the ipsilateral cortex and striatum between 6 h and 28 days post-stroke concurrently with a marked increase in Nox2 mRNA expression up to 7 days, and increased Nox4 mRNA expression detected between 7 and 28 days. Point counting of blood vessels using Metamorph imaging software showed increased vascular sprouting between 3 and 7 days after stroke with new vascular networks detected in the core infarct region by 14 days. Angiogenic blood vessels 3 and 7 days post-stroke were observed to co-localise with both Nox2 antibody and dihydroethidium fluorescence suggesting a role for Nox2 generated superoxide during the phase of vascular remodeling, whilst Nox4 expression was detected once new cerebral vessels had formed. These results indicate for the first time that ROS signaling through a cerebrovascular Nox2 NADPH oxidase may be important in initiating brain angiogenesis.
Efficiency of Edible Agriculture in Canada and the U.S. Over the Past Three and Four Decades
Authors: Hamilton Abbe , Balogh Stephen , Maxwell Adrienna , Hall Charles
Published: March 2013

We examine technological progress in the US and Canada to answer the question: has the efficiency (e.g., the edible energy efficiency, or EEE) for producing agricultural products in the US and Canada increased in recent decades? Specifically, we determined the energy efficiency of agriculture at the farm gate in recent decades by dividing the outputs (the total annual crop and animal output in energy units minus the feed used for animal production and the grain used for ethanol production) by the energy inputs: all the energy used by the nation to produce food (the energy used to generate and apply the fertilizer, pesticides, seed and to operate machinery) minus the energy inputs to produce grain for ethanol. Our data comes primarily from national and international agricultural censuses. Our study found that the energy efficiency of US agriculture has more than doubled from 0.8:1 in 1970 to 2.2:1 by 2000, then increased more slowly to 2.3:1 by 2009. The energy efficiency of the agricultural sector in Canada has not changed appreciably since 1980, and has varied about a mean of 2:1 from 1981 to 2009. Our study found that EEE improvements in the US could be attributable in part to advancements in crop production per hectare, and lower direct fuel consumption, but also a greater proportion of less energy-intensive corn and changes to the diet of livestock (e.g., increased use of meals and other by-products which have increased the availability of grain). Thus increases due to technological progress alone for the last several decades appear small, less than one percent a year.
Annexin A2 Heterotetramer: Structure and Function
Authors: Bharadwaj Alamelu , Bydoun Moamen , Holloway Ryan , Waisman David
Published: March 2013

Annexin A2 is a pleiotropic calcium- and anionic phospholipid-binding protein that exists as a monomer and as a heterotetrameric complex with the plasminogen receptor protein, S100A10. Annexin A2 has been proposed to play a key role in many processes including exocytosis, endocytosis, membrane organization, ion channel conductance, and also to link F-actin cytoskeleton to the plasma membrane. Despite an impressive list of potential binding partners and regulatory activities, it was somewhat unexpected that the annexin A2-null mouse should show a relatively benign phenotype. Studies with the annexin A2-null mouse have suggested important functions for annexin A2 and the heterotetramer in fibrinolysis, in the regulation of the LDL receptor and in cellular redox regulation. However, the demonstration that depletion of annexin A2 causes the depletion of several other proteins including S100A10, fascin and affects the expression of at least sixty-one genes has confounded the reports of its function. In this review we will discuss the annexin A2 structure and function and its proposed physiological and pathological roles.
Mitochondria and Reactive Oxygen Species: Physiology and Pathophysiology
Authors: Bolisetty Subhashini , Jaimes Edgar
Published: March 2013

The air that we breathe contains nearly 21% oxygen, most of which is utilized by mitochondria during respiration. While we cannot live without it, it was perceived as a bane to aerobic organisms due to the generation of reactive oxygen and nitrogen metabolites by mitochondria and other cellular compartments. However, this dogma was challenged when these species were demonstrated to modulate cellular responses through altering signaling pathways. In fact, since this discovery of a dichotomous role of reactive species in immune function and signal transduction, research in this field grew at an exponential pace and the pursuit for mechanisms involved began. Due to a significant number of review articles present on the reactive species mediated cell death, we have focused on emerging novel pathways such as autophagy, signaling and maintenance of the mitochondrial network. Despite its role in several processes, increased reactive species generation has been associated with the origin and pathogenesis of a plethora of diseases. While it is tempting to speculate that anti-oxidant therapy would protect against these disorders, growing evidence suggests that this may not be true. This further supports our belief that these reactive species play a fundamental role in maintenance of cellular and tissue homeostasis.
Abnormal Skeletal Growth in Adolescent Idiopathic Scoliosis Is Associated with Abnormal Quantitative Expression of Melatonin Receptor, MT2
Authors: Yim Annie , Yeung Hiu-yan , Sun Guangquan , Lee Kwong-man , Ng Tzi-bun , Lam Tsz-ping , Ng Bobby , Qiu Yong , Moreau Alain , Cheng Jack
Published: March 2013

The defect of the melatonin signaling pathway has been proposed to be one of the key etiopathogenic factors in adolescent idiopathic scoliosis (AIS). A previous report showed that melatonin receptor, MT2, was undetectable in some AIS girls. The present study aimed to investigate whether the abnormal MT2 expression in AIS is quantitative or qualitative. Cultured osteoblasts were obtained from 41 AIS girls and nine normal controls. Semi-quantification of protein expression by Western blot and mRNA expression by TaqMan real-time PCR for both MT1 and MT2 were performed. Anthropometric parameters were also compared and correlated with the protein expression and mRNA expression of the receptors. The results showed significantly lower protein and mRNA expression of MT2 in AIS girls compared with that in normal controls (p = 0.02 and p = 0.019, respectively). No differences were found in the expression of MT1. When dichotomizing the AIS girls according to their MT2 expression, the group with low expression was found to have a significantly longer arm span (p = 0.036). The results of this study showed for the first time a quantitative change of MT2 in AIS that was also correlated with abnormal arm span as part of abnormal systemic skeletal growth.
Ubiquitinations in the Notch Signaling Pathway
Authors: Moretti Julien , Brou Christel
Published: March 2013

The very conserved Notch pathway is used iteratively during development and adulthood to regulate cell fates. Notch activation relies on interactions between neighboring cells, through the binding of Notch receptors to their ligands, both transmembrane molecules. This inter-cellular contact initiates a cascade of events eventually transforming the cell surface receptor into a nuclear factor acting on the transcription of specific target genes. This review highlights how the various processes undergone by Notch receptors and ligands that regulate the pathway are linked to ubiquitination events.
Characterization of Flavan-3-ols and Expression of MYB and Late Pathway Genes Involved in Proanthocyanidin Biosynthesis in Foliage of Vitis bellula
Authors: Zhu Yue , Peng Qing-Zhong , Du Ci , Li Ke-Gang , Xie De-Yu
Published: March 2013

Proanthocyanidins (PAs) are fundamental nutritional metabolites in different types of grape products consumed by human beings. Although the biosynthesis of PAs in berry of Vitis vinifera has gained intensive investigations, the understanding of PAs in other Vitis species is limited. In this study, we report PA formation and characterization of gene expression involved in PA biosynthesis in leaves of V. bellula, a wild edible grape species native to south and south-west China. Leaves are collected at five developmental stages defined by sizes ranging from 0.5 to 5 cm in length. Analyses of thin layer chromatography (TLC) and high performance liquid chromatography-photodiode array detector (HPLC-PAD) show the formation of (+)-catechin, (−)-epicatechin, (+)-gallocatechin and (−)-epigallocatechin during the entire development of leaves. Analyses of butanol-HCl boiling cleavage coupled with spectrometry measurement at 550 nm show a temporal trend of extractable PA levels, which is characterized by an increase from 0.5 cm to 1.5 cm long leaves followed by a decrease in late stages. TLC and HPLC-PAD analyses identify cyanidin, delphinidin and pelargonidin produced from the cleavage of PAs in the butanol-HCl boiling, showing that the foliage PAs of V. bellula include three different types of extension units. Four cDNAs, which encode VbANR, VbDFR, VbLAR1 and VbLAR2, respectively, are cloned from young leaves. The expression patterns of VbANR and VbLAR2 but not VbLAR1 and VbDFR follow a similar trend as the accumulation patterns of PAs. Two cDNAs encoding VbMYBPA1 and VbMYB5a, the homologs of which have been demonstrated to regulate the expression of both ANR and LAR in V. vinifera, are also cloned and their expression profiles are similar to those of VbANR and VbLAR2. In contrast, the expression profiles of MYBA1 and 2 homologs involved in anthocyanin biosynthesis are different from those of VbANR and VbLAR2. Our data show that both ANR and LAR branches are involved in PA biosynthesis in leaves of V. bellula.
Microbeads for Sampling and Mixing in a Complex Sample
Authors: Owen Drew , Mao Wenbin , Alexeev Alex , Cannon Jennifer , Hesketh Peter
Published: March 2013

This paper presents work on the development of a microfluidic device using super-paramagnetic beads for sampling and mixing. The beads are manipulated via an external rotating permanent magnet in a microfluidic channel. Efficient mixing is achieved in a short distance with this method. Modeling shows the variables which influence the mixing are flow rate, bead rotation speed and the bead number density. Displacement of the bead relative the rotating magnetic field sets an upper limit on the bead rotation speed due to viscous drag. Future work will examine optimization of this system for capture of pathogens from a complex mixture.
Tunable Sensor Response by Voltage-Control in Biomimetic Hair Flow Sensors
Authors: Droogendijk Harmen , Bruinink Christiaan , Sanders Remco , Krijnen Gijs
Published: March 2013

We presented an overview of improvements in detection limit and responsivity of our biomimetic hair flow sensors by electrostatic spring-softening (ESS). Applying a DC-bias voltage to our capacitive flow sensors improves the responsively by up to 80% for flow signals at frequencies below the sensor’s resonance. Application of frequency matched AC-bias voltages allows for tunable filtering and selective gain up to 20 dB. Furthermore, the quality and fidelity of low frequency flow measurements can be improved using a non frequency-matched AC-bias voltage, resulting in a flow detection limit down to 5 mm/s at low (30 Hz) frequencies. The merits and applicability of the three methods are discussed.
Synthesis and Biological Activity of Substituted Urea and Thiourea Derivatives Containing 1,2,4-Triazole Moieties
Authors: Kocyigit-Kaymakcioglu Bedia , Celen Ahmet , Tabanca Nurhayat , Ali Abbas , Khan Shabana , Khan Ikhlas , Wedge David
Published: March 2013

A series of novel thiourea and urea derivatives containing 1,2,4-triazole moieties were synthesized and evaluated for their antifungal and larvicidal activity. Triazole derivatives 3a–e and 4a–e were synthesized by reacting thiocarbohydrazide with thiourea and urea compounds 1a–e and 2a–e, respectively, in a 130–140 °C oil bath. The proposed structures of all the synthesized compounds were confirmed using elemental analysis, UV, IR, 1H-NMR and mass spectroscopy. All compounds were evaluated for antifungal activity against plant pathogens, larvicidal and biting deterrent activity against the mosquito Aedes aegypti L. and in vitro cytotoxicity and anti-inflammatory activity against some human cell lines. Phomopis species were the most sensitive fungi to these compounds. Compounds 1b, 1c, 3a and 4e demonstrated selectively good activity against Phomopis obscurans and only 1b and 4e showed a similar level of activity against P. viticola. Compound 3d, with a LD50 value of 67.9 ppm, followed by 1c (LD50 = 118.8 ppm) and 3e (LD50 = 165.6 ppm), showed the highest toxicity against Aedes aegypti larvae. Four of these compounds showed biting deterrent activity greater than solvent control, with the highest activity being seen for 1c, with a proportion not biting (PNB) value of 0.75, followed by 1e, 2b and 1a. No cytotoxicity was observed against the tested human cancer cell lines. No anti-inflammatory activity was observed against NF-kB dependent transcription induced by phorbol myristate acetate (PMA) in human chondrosarcoma cells.
Chromophoric Dissolved Organic Matter and Dissolved Organic Carbon from Sea-Viewing Wide Field-of-View Sensor (SeaWiFS), Moderate Resolution Imaging Spectroradiometer (MODIS) and MERIS Sensors: Case Study for the Northern Gulf of Mexico
Authors: Tehrani Nazanin , D'Sa Eurico , Osburn Christopher , Bianchi Thomas , Schaeffer Blake
Published: March 2013

Empirical band ratio algorithms for the estimation of colored dissolved organic matter (CDOM) and dissolved organic carbon (DOC) for Sea-viewing Wide Field-of-view Sensor (SeaWiFS), Moderate Resolution Imaging Spectroradiometer (MODIS) and MERIS ocean color sensors were assessed and developed for the northern Gulf of Mexico. Match-ups between in situ measurements of CDOM absorption coefficients at 412 nm (aCDOM(412)) with that derived from SeaWiFS were examined using two previously reported reflectance band ratio algorithms. Results indicate better performance using the Rrs(510)/Rrs(555) (Bias = −0.045; RMSE = 0.23; SI = 0.49, and R2 = 0.66) than the Rrs(490)/Rrs(555) reflectance band ratio algorithm. Further, a comparison of aCDOM(412) retrievals using the Rrs(488)/Rrs(555) for MODIS and Rrs(510)/Rrs(560) for MERIS reflectance band ratios revealed better CDOM retrievals with MERIS data. Since DOC cannot be measured directly by remote sensors, CDOM as the colored component of DOC is utilized as a proxy to estimate DOC remotely. A seasonal relationship between CDOM and DOC was established for the summer and spring-winter with high correlation for both periods (R2~0.9). Seasonal band ratio empirical algorithms to estimate DOC were thus developed using the relationships between CDOM-Rrs and seasonal CDOM-DOC for SeaWiFS, MODIS and MERIS. Results of match-up comparisons revealed DOC estimates by both MODIS and MERIS to be relatively more accurate during summer time, while both of them underestimated DOC during spring-winter time. A better DOC estimate from MERIS in comparison to MODIS in spring-winter could be attributed to its similarity with the SeaWiFS band ratio CDOM algorithm.
Electrical Characterization and Hydrogen Peroxide Sensing Properties of Gold/Nafion:Polypyrrole/MWCNTs Electrochemical Devices
Authors: Scandurra Graziella , Arena Antonella , Ciofi Carmine , Saitta Gaetano
Published: March 2013

Electrochemical devices using as substrates copier grade transparency sheets are developed by using ion conducting Nafion:polypyrrole mixtures, deposited between gold bottom electrodes and upper electrodes based on Multi Walled Carbon Nanotubes (MWCNTs). The electrical properties of the Nafion:polypyrrole blends and of the gold/Nafion:polypyrrole/MWCNTs devices are investigated under dry conditions and in deionized water by means of frequency dependent impedance measurements and time domain electrical characterization. According to current-voltage measurements carried out in deionized water, the steady state current forms cycles characterized by redox peaks, the intensity and position of which reversibly change in response to H2O2, with a lower detection limit in the micromolar range. The sensitivity that is obtained is comparable with that of other electrochemical sensors that however, unlike our devices, require supporting electrolytes.
Microfoundations for Sustainable Growth with Eco-Intelligent Product Service-Arrangements
Authors: Liedtke Christa , Buhl Johannes , Ameli Najine
Published: March 2013

This paper argues that the contemporary growth paradigm needs to be reconsidered on a micro level of consumption and product service-systems. This becomes necessary since a dynamic link between macro strategies and micro implementation of sustainable growth is missing up to date. Therefore, mainstream sustainability strategies of efficiency and consistency are extended by sufficiency in order to integrate strategies for individual welfare within their social environment. Limits to and drivers for growth are revised and updated socially in terms of qualitative values, diminishing marginal utility or symbolic social distinction. We elaborate a definition of sustainable growth that fosters individual welfare by enhancing social enactment within the boundaries of environmental space. Shifting focus on social aspects in design fosters more sustainable production and consumption patterns while sustaining individual welfare. We derive latent indications for eco-intelligent product service-arrangements and evaluate to concepts by referring to introduced definitions and according indications. With doing so, we illustrate new pathways for the translation of sustainable growth and strategies into product service-systems.
Climate isn't everything: Competitive interactions and variation by life stage will also affect range shifts in a warming world
Authors: Ettinger Ailene K. , HilleRisLambers Janneke
Published: March 2013

• Premise of the study: The extent to which climate controls species’ range limits is a classic biological question that is particularly relevant given anthropogenic climate change. While climate is known to play a role in species distributions, biotic interactions such as competition also affect range limits. Furthermore, climatic and biotic controls of ranges may vary in strength across life stages, implying complex range shift dynamics with climate change.

• Methods: We quantified climatic and competitive influences on growth of juvenile and adult trees of three conifer species on Mt. Rainier, Washington, United States. We collected annual growth data of these trees, which we compared to the competitive environment and annual climate (100 years of data) experienced by each individual.

• Key results: We found that the relationships between growth and climate and between growth and competition differed by life stage and location. Growth was sensitive to heavy snowpack and cold temperatures at high elevation upper limits (treeline), but growth was poorly explained by climate in low elevation closed‐canopy forests. Competitive effects on growth were more important for saplings than adults, but did not become more important at either upper or lower range limits.

• Conclusions: In all, our results suggest that range shifts under climate change will differ at leading vs. trailing edges. At treeline, warmer temperatures will lead to increased growth and likely to range expansion. However, climate change will have less dramatic effects in low elevation closed‐canopy forest communities, where growth is less strongly limited by climate, especially at young life stages.
Multiple metal accumulation within a manganese‐specific genus
Authors: Fernando Denise R. , Marshall Alan T. , Forster Paul I. , Hoebee Susan E. , Siegele Rainer
Published: March 2013

• Premise of the study: Plants that strongly accumulate metals may be practically beneficial, and also serve as novel resources for increasing fundamental understanding of plant biology. Australian Gossia (Myrtaceae) species are delineated by a conspicuous affinity for the heavy metal manganese (Mn), which is a micronutrient crucial to photosynthesis. This genus includes several Mn hyperaccumulators such as G. bidwillii. Unusually, in G. bidwillii foliar Mn is most highly concentrated in photosynthetic cells, an observation thus far restricted to foliar‐Mn accumulation in Mn hyperaccumulators. Recent discovery that several of these Gossia species accumulate other metals in addition to Mn will enable investigation as to whether primary sequestration of metals in photosynthetic tissues is restricted to Mn.

• Methods: Gossia species known to accumulate nickel (Ni) or aluminum (Al) in addition to Mn were sampled in the field. Complementary proton‐ and electron‐probe data were combined to evaluate in vivo microdistribution patterns of excessively accumulated foliar metals.

• Key results: It was discovered that in addition to Mn and Ni, Gossia fragrantissima accumulated foliar zinc (Zn) and cobalt (Co), with Mn, Ni, and Co most highly localized in mesophyll cells and Zn primarily located in the upper epidermis. In G. hillii, Mn and Al were highly concentrated in the palisade and epidermis, respectively.

• Conclusions: This investigation provides evidence that the primary disposal of excess foliar metals in photosynthetic cells is not exclusive to Mn. It offers rare intrageneric perspective on metal compartmentation, pointing to significant variation among tonoplastal metal transporters associated with detoxification.
Synthesis of 2,3-dihydronaphtho[2,3-d][1,3]thiazole-4,9-diones and 2,3-dihydroanthra[2,3-d][1,3]thiazole-4,11-diones and novel ring contraction and fusion reaction of 3H-spiro[1,3-thiazole-2,1'-cyclohexanes] into 2,3,4,5-tetrahydro-1H-carbazole-6,11-diones
Authors: Konstantinova Lidia S , Lysov Kirill A , Souvorova Ljudmila I , Rakitin Oleg A
Published: March 2013

Treatment of N-substituted 2-(methylamino)naphthoquinones 3 and -anthracene-1,4-diones 4 with S2Cl2 and DABCO in chlorobenzene gave the corresponding 2,3-dihydronaphtho[2,3-d][1,3]thiazole-4,9-diones 1 and 2,3-dihydroanthra[2,3-d][1,3]thiazole-4,11-diones 2 by triethylamine addition, in high to moderate yields. The DABCO replacement for N-ethyldiisopropylamine in the reaction of anthracene-1,4-diones 4 led unexpectedly to the corresponding 2-thioxo-2,3-dihydroanthra[2,3-d][1,3]thiazole-4,11-diones 10. The reaction of 3H-spiro[1,3-thiazole-2,1'-cyclohexanes] 1d, 2d with Et3N in chlorobenzene under reflux yielded 2,3,4,5-tetrahydro-1H-carbazole-6,11-diones 15, 16, i.e., ring contraction and fusion products. A plausible mechanism was proposed for the formation of the products.