Determinants of Academic Performance in Public Day Secondary ...

African Journals Online (AJOL)

Determinants of Academic Performance in Public Day Secondary Schools, Manga District, Kenya. ... Journal of Technology and Education in Nigeria ... student's discipline, student's entry mark, teacher's teaching experience and level of education among others have significant impact in academic performance of a child.

Modelling secondary eclipses of Kepler exoplanets

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Hambálek Lubomír

2015-01-01

Full Text Available We have selected several Kepler objects with potentially the deepest secondary eclipses. By combination of many single phased light-curves (LCs we have produced a smooth LC with a larger SNR and made the secondary eclipses more distinct. This allowed us to measure the depth of primary and secondary minimum with greater accuracy and then to determine stellar and planetary radii by simplex modelling.

Applying Standards for Leaders to the Selection of Secondary School Principals

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Wildy, Helen; Pepper, Coral; Guanzhong, Luo

2011-01-01

Purpose: The purpose of this paper is to report innovative research aimed at ascertaining whether standards for school leaders could be applied to the process of selecting senior secondary school principals for appointment. Specifically, psychometrically robust measures of performance are sought that would sufficiently differentiate performance to…

Competitive Foods and Beverages Available for Purchase in Secondary Schools--Selected Sites, United States, 2004

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Kann, L.; Grunbaum, J.; McKenna, M. L.; Wechsler, H.; Galuska, D. A.

2005-01-01

School Health Profiles is conducted biennially to assess characteristics of school health programs. State and local departments of education and health select either all public secondary schools within their jurisdictions or a systematic, equal-probability sample of public secondary schools to participate in School Health Profiles. At each school,…

Bourdieu's Distinction between Rules and Strategies and Secondary Principal Practice: A Review of Selected Literature

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Anderson, Karen

2016-01-01

This paper reviews a selection of literature on secondary principal practice from which to propose an approach for further research. The review demonstrates that applications of Bourdieu's theory of practice have contributed to understandings about secondary principal practice, and that the distinction he made between rules and strategies has the…

Smoking among school-going adolescents in selected secondary schools in Peninsular Malaysia- findings from the Malaysian Adolescent Health Risk Behaviour (MyaHRB) study.

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Lim, Kuang Hock; Lim, Hui Li; Teh, Chien Huey; Kee, Chee Cheong; Khoo, Yi Yi; Ganapathy, Shubash Shander; Jane Ling, Miaw Yn; Mohd Ghazali, Sumarni; Tee, Eng Ong

2017-01-01

A multitude of studies have revealed that smoking is a learned behaviour during adolescence and efforts to reduce the incidence of smoking has been identified as long-term measures to curb the smoking menace. The objective of this study was to determine the prevalence as well as the intra and inter-personal factors associated with smoking among upper secondary school students in selected schools in Peninsular Malaysia. A study was carried out in 2013, which involved a total of 40 secondary schools. They were randomly selected using a two-stage clustering sampling method. Subsequently, all upper secondary school students (aged 16 to 17 years) from each selected school were recruited into the study. Data was collected using a validated standardised questionnaire. This study revealed that the prevalence of smoking was 14.6% (95% CI:13.3-15.9), and it was significantly higher among males compared to females (27.9% vs 2.4%, p  Malaysian adolescents of school-going age was high, despite implementation of several anti-smoking measures in Malaysia. More robust measures integrating the factors identified in this study are strongly recommended to curb the smoking epidemic among adolescents in Malaysia.

Selection criteria for the best secondary water chemistry

International Nuclear Information System (INIS)

Nordmann, F.; Fiquet, J.M.

1996-01-01

This paper describes, for PWR plants, the approach for selecting the best chemistry-pH, amine, corrosion inhibitors-according to the secondary system characteristics, such as presence or not of copper alloys, steam generator tubing alloy, tube support plate design, sludge pile importance. The impact of condensate polisher, sludge lancing, chemical cleaning, as well as other ways of eliminating undesirable compounds or mitigating them are also discussed. For plants with simultaneous presence of carbon steel and copper alloys, alternate amines like morpholine, or new reagents such as ethanolamine (ETA), can be selected to manage erosion-corrosion of carbon steel and decrease corrosion transport, at a pH acceptable for copper alloys (9.2 at 25 C). In more recent units, with an all ferrous system, a high pH operation, with only hydrazine addition, the easiest way, or with combined hydrazine and morpholine or ETA will be of some benefit against steam generator corrosion. When Alloy 600 has been selected, inhibitors such as boric acid, or maybe titanium oxide or cerium in the future, needs to be added in steam generators in order to decrease intergranular corrosion progression. In addition, caustic and lead contaminations must be strictly avoided, while sludge and deposits will be eliminated by lancing and chemical cleaning, if necessary. (orig.)

Secondary metabolites in fungus-plant interactions

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Pusztahelyi, Tünde; Holb, Imre J.; Pócsi, István

2015-01-01

Fungi and plants are rich sources of thousands of secondary metabolites. The genetically coded possibilities for secondary metabolite production, the stimuli of the production, and the special phytotoxins basically determine the microscopic fungi-host plant interactions and the pathogenic lifestyle of fungi. The review introduces plant secondary metabolites usually with antifungal effect as well as the importance of signaling molecules in induced systemic resistance and systemic acquired resistance processes. The review also concerns the mimicking of plant effector molecules like auxins, gibberellins and abscisic acid by fungal secondary metabolites that modulate plant growth or even can subvert the plant defense responses such as programmed cell death to gain nutrients for fungal growth and colonization. It also looks through the special secondary metabolite production and host selective toxins of some significant fungal pathogens and the plant response in form of phytoalexin production. New results coming from genome and transcriptional analyses in context of selected fungal pathogens and their hosts are also discussed. PMID:26300892

Selective Attentional Effects of Adjunct Study Questions on Achievement in Nigerian Secondary School Science

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Okoye, Nnamdi S.

2008-01-01

The study investigated the selective attentional effects of adjunct study questions inserted before or after the presentation of science flow diagrams. The basic design for the study was a post-test only control group design involving a total of 252 students randomly selected from six secondary schools in Ile-Ife, Oshun State Nigeria. These were…

The selectivity of receptor tyrosine kinase signaling is controlled by a secondary SH2 domain binding site.

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Bae, Jae Hyun; Lew, Erin Denise; Yuzawa, Satoru; Tomé, Francisco; Lax, Irit; Schlessinger, Joseph

2009-08-07

SH2 domain-mediated interactions represent a crucial step in transmembrane signaling by receptor tyrosine kinases. SH2 domains recognize phosphotyrosine (pY) in the context of particular sequence motifs in receptor phosphorylation sites. However, the modest binding affinity of SH2 domains to pY containing peptides may not account for and likely represents an oversimplified mechanism for regulation of selectivity of signaling pathways in living cells. Here we describe the crystal structure of the activated tyrosine kinase domain of FGFR1 in complex with a phospholipase Cgamma fragment. The structural and biochemical data and experiments with cultured cells show that the selectivity of phospholipase Cgamma binding and signaling via activated FGFR1 are determined by interactions between a secondary binding site on an SH2 domain and a region in FGFR1 kinase domain in a phosphorylation independent manner. These experiments reveal a mechanism for how SH2 domain selectivity is regulated in vivo to mediate a specific cellular process.

[Determination of the profiles of secondary metabolites characteristic of Alternaria strains isolated from tomato].

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Benavidez Rozo, Martha Elizabeth; Patriarca, Andrea; Cabrera, Gabriela; Fernández Pinto, Virginia E

2014-01-01

Many Alternaria species have been studied for their ability to produce bioactive secondary metabolites, such as tentoxin (TEN), some of which have toxic properties. The main food contaminant toxins are tenuazonic acid, alternariol (AOH), alternariol monomethyl ether (AME), altenuene, and altertoxins i, ii and iii. To determine the profiles of secondary metabolites characteristic of Alternaria strains isolated from tomato for their chemotaxonomic classification. The profiles of secondary metabolites were determined by HPLC MS. The Alternaria isolates obtained from spoiled tomatoes belong, according to their morphological characteristics, to the species groups Alternaria alternata, Alternaria tenuissima and Alternaria arborescens, with A. tenuissima being the most frequent. The most frequent profiles of secondary metabolites belonging to the species groups A. alternata (AOH, AME, TEN), A. tenuissima (AOH, AME, TEN, tenuazonic acid) and A. arborescens (AOH, AME, TEN, tenuazonic acid) were determined, with some isolates of the latter being able to synthesize AAL toxins. Secondary metabolite profiles are a useful tool for the differentiation of small spored Alternaria isolates not easily identifiable by their morphological characteristics. Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

Selection gradients, the opportunity for selection, and the coefficient of determination.

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Moorad, Jacob A; Wade, Michael J

2013-03-01

Abstract We derive the relationship between R(2) (the coefficient of determination), selection gradients, and the opportunity for selection for univariate and multivariate cases. Our main result is to show that the portion of the opportunity for selection that is caused by variation for any trait is equal to the product of its selection gradient and its selection differential. This relationship is a corollary of the first and second fundamental theorems of natural selection, and it permits one to investigate the portions of the total opportunity for selection that are involved in directional selection, stabilizing (and diversifying) selection, and correlational selection, which is important to morphological integration. It also allows one to determine the fraction of fitness variation not explained by variation in measured phenotypes and therefore attributable to random (or, at least, unknown) influences. We apply our methods to a human data set to show how sex-specific mating success as a component of fitness variance can be decoupled from that owing to prereproductive mortality. By quantifying linear sources of sexual selection and quadratic sources of sexual selection, we illustrate that the former is stronger in males, while the latter is stronger in females.

Accurate and precise measurement of oxygen isotopic fractions and diffusion profiles by selective attenuation of secondary ions (SASI).

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Téllez, Helena; Druce, John; Hong, Jong-Eun; Ishihara, Tatsumi; Kilner, John A

2015-03-03

The accuracy and precision of isotopic analysis in Time-of-Flight secondary ion mass spectrometry (ToF-SIMS) relies on the appropriate reduction of the dead-time and detector saturation effects, especially when analyzing species with high ion yields or present in high concentrations. Conventional approaches to avoid these problems are based on Poisson dead-time correction and/or an overall decrease of the total secondary ion intensity by reducing the target current. This ultimately leads to poor detection limits for the minor isotopes and high uncertainties of the measured isotopic ratios. An alternative strategy consists of the attenuation of those specific secondary ions that saturate the detector, providing an effective extension of the linear dynamic range. In this work, the selective attenuation of secondary ion signals (SASI) approach is applied to the study of oxygen transport properties in electroceramic materials by isotopic labeling with stable (18)O tracer and ToF-SIMS depth profiling. The better analytical performance in terms of accuracy and precision allowed a more reliable determination of the oxygen surface exchange and diffusion coefficients while maintaining good mass resolution and limits of detection for other minor secondary ion species. This improvement is especially relevant to understand the ionic transport mechanisms and properties of solid materials, such as the parallel diffusion pathways (e.g., oxygen diffusion through bulk, grain boundary, or dislocations) in electroceramic materials with relevant applications in energy storage and conversion devices.

Determinants of Sexual Violence among Eastern Ethiopian Secondary School Students

NARCIS (Netherlands)

MA Bekele, A.B.

2012-01-01

The purpose of this dissertation was to investigate the determinants of sexual violence among Eastern Ethiopia secondary school students. To this end, we studied risk and protective factors for both sexual violence perpetration and victimization, and the moderating role of protective factors on the

Plant protein and secondary metabolites influence diet selection in a mammalian specialist herbivore

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Ulappa, Amy C.; Kelsey, Rick G.; Frye, Graham G.; Rachlow, Janet L.; Shipley, Lisa A.; Bond, Laura; Pu, Xinzhu; Forbey, Jennifer Sorensen

2015-01-01

For herbivores, nutrient intake is limited by the relatively low nutritional quality of plants and high concentrations of potentially toxic defensive compounds (plant secondary metabolites, PSMs) produced by many plants. In response to phytochemical challenges, some herbivores selectively forage on plants with higher nutrient and lower PSM concentrations relative to other plants. Pygmy rabbits (Brachylagus idahoensis) are dietary specialists that feed on sagebrush (Artemisia spp.) and forage on specific plants more than others within a foraging patch. We predicted that the plants with evidence of heavy foraging (browsed plants) would be of higher dietary quality than plants that were not browsed (unbrowsed). We used model selection to determine which phytochemical variables best explained the difference between browsed and unbrowsed plants. Higher crude protein increased the odds that plants would be browsed by pygmy rabbits and the opposite was the case for certain PSMs. Additionally, because pygmy rabbits can occupy foraging patches (burrows) for consecutive years, their browsing may influence the nutritional and PSM constituents of plants at the burrows. In a post hoc analysis, we did not find a significant relationship between phytochemical concentrations, browse status and burrow occupancy length. We concluded that pygmy rabbits use nutritional and chemical cues while making foraging decisions. PMID:26366011

The mechanisms of determiner selection and its relation to lexical selection : An ERP study

NARCIS (Netherlands)

D'Hooge, Elisah; De Baene, W.; Hartsuiker, Robert J

2016-01-01

The language production literature has given only little attention to the dynamics of closed class word selection, such as determiner selection, and its temporal relation to the selection of open class words. The goal of this paper was to investigate whether determiner selection follows serially

Color test for selective detection of secondary amines on resin and in solution

DEFF Research Database (Denmark)

Boas, Ulrik; Mirsharghi, Sahar

2014-01-01

Resins for solid-phase synthesis give orange to red-brown resin beads selectively when secondary amines are present on the resin when treated with a solution of acetaldehyde and an Fmoc-amino acid in NMP. The method shows good specificity and gives colorless beads when exposed to a variety of oth...

Plant protein and secondary metabolites influence diet selection in a mammalian specialist herbivore

Science.gov (United States)

Amy C. Ulappa; Rick G. Kelsey; Graham G. Frye; Janet L. Rachlow; LIsa A. Shipley; Laura Bond; Xinzhu Pu; Jennifer Sorensen. Forbey

2014-01-01

For herbivores, nutrient intake is limited by the relatively low nutritional quality of plants and high concentrations of potentially toxic defensive compounds (plant secondary metabolites [PSMs]) produced by many plants. In response to phytochemical challenges, some herbivores selectively forage on plants with higher nutrient and lower PSM concentrations relative to...

A Sensitive Secondary Users Selection Algorithm for Cognitive Radio Ad Hoc Networks

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Aohan Li

2016-03-01

Full Text Available Secondary Users (SUs are allowed to use the temporarily unused licensed spectrum without disturbing Primary Users (PUs in Cognitive Radio Ad Hoc Networks (CRAHNs. Existing architectures for CRAHNs impose energy-consuming Cognitive Radios (CRs on SUs. However, the advanced CRs will increase energy cost for their cognitive functionalities, which is undesirable for the battery powered devices. A new architecture referred to as spectral Requirement-based CRAHN (RCRAHN is proposed to enhance energy efficiency for CRAHNs in this paper. In RCRAHNs, only parts of SUs are equipped with CRs. SUs equipped with CRs are referred to as Cognitive Radio Users (CRUs. To further enhance energy efficiency of CRAHNs, we aim to select minimum CRUs to sense available spectrum. A non-linear programming problem is mathematically formulated under the constraints of energy efficiency and real-time. Considering the NP-hardness of the problem, a framework of a heuristic algorithm referred to as Sensitive Secondary Users Selection (SSUS was designed to compute the near-optimal solutions. The simulation results demonstrate that SSUS not only improves the energy efficiency, but also achieves satisfied performances in end-to-end delay and communication reliability.

A Sensitive Secondary Users Selection Algorithm for Cognitive Radio Ad Hoc Networks.

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Li, Aohan; Han, Guangjie; Wan, Liangtian; Shu, Lei

2016-03-26

Secondary Users (SUs) are allowed to use the temporarily unused licensed spectrum without disturbing Primary Users (PUs) in Cognitive Radio Ad Hoc Networks (CRAHNs). Existing architectures for CRAHNs impose energy-consuming Cognitive Radios (CRs) on SUs. However, the advanced CRs will increase energy cost for their cognitive functionalities, which is undesirable for the battery powered devices. A new architecture referred to as spectral Requirement-based CRAHN (RCRAHN) is proposed to enhance energy efficiency for CRAHNs in this paper. In RCRAHNs, only parts of SUs are equipped with CRs. SUs equipped with CRs are referred to as Cognitive Radio Users (CRUs). To further enhance energy efficiency of CRAHNs, we aim to select minimum CRUs to sense available spectrum. A non-linear programming problem is mathematically formulated under the constraints of energy efficiency and real-time. Considering the NP-hardness of the problem, a framework of a heuristic algorithm referred to as Sensitive Secondary Users Selection (SSUS) was designed to compute the near-optimal solutions. The simulation results demonstrate that SSUS not only improves the energy efficiency, but also achieves satisfied performances in end-to-end delay and communication reliability.

ANALYSIS OF THE SECONDARY CURVES IN PATIENTS UNDERGOING SELECTIVE ARTHRODESIS LENKE I

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TADEU GERVAZONI DEBOM

2015-12-01

Full Text Available Objective : To radiographically evaluate the behavior of the secondary curves in the coronal and sagittal planes in patients with AIS classified as Lenke I, who underwent surgical treatment of selective arthrodesis by posterior approach. Methods : Retrospective study which analyzed 40 patients with AIS, being 33 female. The measurement of the radiographic parameters used followed the recommendations by Cobb. Results : The average correction of the thoracic proximal, primary and lumbar curves was 34.73%, 75.06% and 64.64%, respectively. Conclusion : Surgical treatment by selective arthrodesis in cases of AIS Lenke type I provide correction of compensatory curves in the coronal and maintenance in the sagittal plane.

Selective N-alkylation of amines using nitriles under hydrogenation conditions: facile synthesis of secondary and tertiary amines.

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Ikawa, Takashi; Fujita, Yuki; Mizusaki, Tomoteru; Betsuin, Sae; Takamatsu, Haruki; Maegawa, Tomohiro; Monguchi, Yasunari; Sajiki, Hironao

2012-01-14

Nitriles were found to be highly effective alkylating reagents for the selective N-alkylation of amines under catalytic hydrogenation conditions. For the aromatic primary amines, the corresponding secondary amines were selectively obtained under Pd/C-catalyzed hydrogenation conditions. Although the use of electron poor aromatic amines or bulky nitriles showed a lower reactivity toward the reductive alkylation, the addition of NH(4)OAc enhanced the reactivity to give secondary aromatic amines in good to excellent yields. Under the same reaction conditions, aromatic nitro compounds instead of the aromatic primary amines could be directly transformed into secondary amines via a domino reaction involving the one-pot hydrogenation of the nitro group and the reductive alkylation of the amines. While aliphatic amines were effectively converted to the corresponding tertiary amines under Pd/C-catalyzed conditions, Rh/C was a highly effective catalyst for the N-monoalkylation of aliphatic primary amines without over-alkylation to the tertiary amines. Furthermore, the combination of the Rh/C-catalyzed N-monoalkylation of the aliphatic primary amines and additional Pd/C-catalyzed alkylation of the resulting secondary aliphatic amines could selectively prepare aliphatic tertiary amines possessing three different alkyl groups. According to the mechanistic studies, it seems reasonable to conclude that nitriles were reduced to aldimines before the nucleophilic attack of the amine during the first step of the reaction.

The Availability and Utilization of School Library Resources in Some Selected Secondary Schools (High School) in Rivers State

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Owate, C. N.; Iroha, Okpa

2013-01-01

This study investigates the availability and utilization of school library resources by Secondary School (High School) Students. Eight Selected Secondary Schools in Rivers State, Nigeria were chosen based on their performance in external examinations and geographic locations. In carrying out the research, questionnaires were administered to both…

Algorithm for selection of optimized EPR distance restraints for de novo protein structure determination

Science.gov (United States)

Kazmier, Kelli; Alexander, Nathan S.; Meiler, Jens; Mchaourab, Hassane S.

2010-01-01

A hybrid protein structure determination approach combining sparse Electron Paramagnetic Resonance (EPR) distance restraints and Rosetta de novo protein folding has been previously demonstrated to yield high quality models (Alexander et al., 2008). However, widespread application of this methodology to proteins of unknown structures is hindered by the lack of a general strategy to place spin label pairs in the primary sequence. In this work, we report the development of an algorithm that optimally selects spin labeling positions for the purpose of distance measurements by EPR. For the α-helical subdomain of T4 lysozyme (T4L), simulated restraints that maximize sequence separation between the two spin labels while simultaneously ensuring pairwise connectivity of secondary structure elements yielded vastly improved models by Rosetta folding. 50% of all these models have the correct fold compared to only 21% and 8% correctly folded models when randomly placed restraints or no restraints are used, respectively. Moreover, the improvements in model quality require a limited number of optimized restraints, the number of which is determined by the pairwise connectivities of T4L α-helices. The predicted improvement in Rosetta model quality was verified by experimental determination of distances between spin labels pairs selected by the algorithm. Overall, our results reinforce the rationale for the combined use of sparse EPR distance restraints and de novo folding. By alleviating the experimental bottleneck associated with restraint selection, this algorithm sets the stage for extending computational structure determination to larger, traditionally elusive protein topologies of critical structural and biochemical importance. PMID:21074624

Landscape perception based on personal attributes in determining the scenic beauty of in-stand natural secondary forests

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Yong Chen

2016-06-01

Full Text Available The aim of this paper was to validate factors affecting the in-stand landscape quality and how important each factor was in determining scenic beauty of natural secondary forests. The study was limited to 23 stand-level cases of natural secondary forests in Shen Zhen city in southern China. Typical samples of photographs and public estimations were applied to evaluate scenic beauty inside the natural secondary forests. The major factors were then selected by multiple linear-regression analysis and a model between scenic beauty estimation (SBE values and in-stand landscape features was established. Rise in crown density, fall in plant litter, glow in color of trunk, fall in arbor richness, and rise in visible distance increased scenic beauty values of in-stand landscape. These five factors significantly explained the differences in scenic beauty, and together accounted for 45% of total variance in SBEs. Personal factors (e.g. gender, age and education did not significantly affect the ratings of landscape photos, although variations of landscape quality were affected by some personal factors. Results of this study will assist policymakers, silviculturists and planners in landscape design and management of natural secondary forests in Shenzhen city. People can improve the scenic beauty values by pruning branches and clearing plant litter, which subsequently improve the forest health and contribute to forest recreation.

Combining sequence-based prediction methods and circular dichroism and infrared spectroscopic data to improve protein secondary structure determinations

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Lees Jonathan G

2008-01-01

Full Text Available Abstract Background A number of sequence-based methods exist for protein secondary structure prediction. Protein secondary structures can also be determined experimentally from circular dichroism, and infrared spectroscopic data using empirical analysis methods. It has been proposed that comparable accuracy can be obtained from sequence-based predictions as from these biophysical measurements. Here we have examined the secondary structure determination accuracies of sequence prediction methods with the empirically determined values from the spectroscopic data on datasets of proteins for which both crystal structures and spectroscopic data are available. Results In this study we show that the sequence prediction methods have accuracies nearly comparable to those of spectroscopic methods. However, we also demonstrate that combining the spectroscopic and sequences techniques produces significant overall improvements in secondary structure determinations. In addition, combining the extra information content available from synchrotron radiation circular dichroism data with sequence methods also shows improvements. Conclusion Combining sequence prediction with experimentally determined spectroscopic methods for protein secondary structure content significantly enhances the accuracy of the overall results obtained.

Plant growth analysis used as secondary traits in selection for high yield on groundnut

International Nuclear Information System (INIS)

Manshuri, A.G.; Nugrahaeni

1996-01-01

Groundnut growth and yield can be expressed as the product to solar radiation interception (Qi), conversion efficiency of radiation to total dry matter (Ek) and partitioning efficiency to economic yield (Ep) or harvest index. Groundnut genotypes differ in characters related to Qi, Ek and Ep, and the characters have the possibility to be used as secondary traits in selection for high yield. Extinction coefficient (k) and leaf area index (LAI) are the influential factors in increasing Qi. Variability in leaf size lead to the description of the existence of variability in k value within the genotypes under study. LAI three is the level necessary to attain 90 percent total radiation absorption in groundnut. An increased of LAI exceeding four would be inefficient for increasing the fraction of radiation absorption. Convertion efficiency of radiation to total dry matter (Ek) related to the rate of plant photosynthesis and respiration, inspite of the need study the field, however, the study was still limited. Harvest index can be used as a secondary trait to identify high yield genotypes. There was a positive correlation between pod yield and harvest index. An increased of harvest index by 1 percent caused an increased of dry pod as high as 0.365 g/plant. ICG 1697, ICGV 86844 and ICGV 87161 gave yield more than 3.5 t/ha, and their total dry matter (TDM) were 49.2, 52.5 and 40.7 g/plant, whereas their harvest indexes (HI) were 0.47, 0.46 and 0.55, respectively. Theoretically, improvement of the groundnut pod yield can be attained by using variety which has TDM 52.5 g/plant and HI 0.55. Using HI as secondary selection criteria, five genotypes were selected, i.e., G/C/LM-88-B-25 (HI 0.59), local Irian and local Lombok (HI 0.57), ICGV 87161 and LM/ICGV 87165-B-2-1 (HI 0.55). Two genotypes were selected for their high TDM, namely ICGV 86844 and LM/ICGV 87165-88-B-82 [in

Protein energetic conformational analysis from NMR chemical shifts (PECAN) and its use in determining secondary structural elements

Energy Technology Data Exchange (ETDEWEB)

Eghbalnia, Hamid R.; Wang Liya; Bahrami, Arash [National Magnetic Resonance Facility at Madison, Biochemistry Department (United States); Assadi, Amir [University of Wisconsin-Madison, Mathematics Department (United States); Markley, John L. [National Magnetic Resonance Facility at Madison, Biochemistry Department (United States)], E-mail: eghbalni@nmrfam.wisc.edu

2005-05-15

We present an energy model that combines information from the amino acid sequence of a protein and available NMR chemical shifts for the purposes of identifying low energy conformations and determining elements of secondary structure. The model ('PECAN', Protein Energetic Conformational Analysis from NMR chemical shifts) optimizes a combination of sequence information and residue-specific statistical energy function to yield energetic descriptions most favorable to predicting secondary structure. Compared to prior methods for secondary structure determination, PECAN provides increased accuracy and range, particularly in regions of extended structure. Moreover, PECAN uses the energetics to identify residues located at the boundaries between regions of predicted secondary structure that may not fit the stringent secondary structure class definitions. The energy model offers insights into the local energetic patterns that underlie conformational preferences. For example, it shows that the information content for defining secondary structure is localized about a residue and reaches a maximum when two residues on either side are considered. The current release of the PECAN software determines the well-defined regions of secondary structure in novel proteins with assigned chemical shifts with an overall accuracy of 90%, which is close to the practical limit of achievable accuracy in classifying the states.

Protein energetic conformational analysis from NMR chemical shifts (PECAN) and its use in determining secondary structural elements

International Nuclear Information System (INIS)

Eghbalnia, Hamid R.; Wang Liya; Bahrami, Arash; Assadi, Amir; Markley, John L.

2005-01-01

We present an energy model that combines information from the amino acid sequence of a protein and available NMR chemical shifts for the purposes of identifying low energy conformations and determining elements of secondary structure. The model ('PECAN', Protein Energetic Conformational Analysis from NMR chemical shifts) optimizes a combination of sequence information and residue-specific statistical energy function to yield energetic descriptions most favorable to predicting secondary structure. Compared to prior methods for secondary structure determination, PECAN provides increased accuracy and range, particularly in regions of extended structure. Moreover, PECAN uses the energetics to identify residues located at the boundaries between regions of predicted secondary structure that may not fit the stringent secondary structure class definitions. The energy model offers insights into the local energetic patterns that underlie conformational preferences. For example, it shows that the information content for defining secondary structure is localized about a residue and reaches a maximum when two residues on either side are considered. The current release of the PECAN software determines the well-defined regions of secondary structure in novel proteins with assigned chemical shifts with an overall accuracy of 90%, which is close to the practical limit of achievable accuracy in classifying the states

Determination of the secondary electron equilibrium using an extrapolation chamber

International Nuclear Information System (INIS)

Marshall, E.T.; Vaziri, K.; Krueger, F.P.; Cossairt, J.D.

1996-09-01

To ensure that the external personnel dosimetry program conducted by U. S. Department of Energy (DOE) contractors is of the highest quality, the DOE established the Department of Energy Laboratory Accreditation Program or DOELAP. The contractor's dosimetry program is assessed against the criteria set forth for dosimeter performance and the associated quality assurance and calibration programs. Although personnel dosimeters are not processed or calibrated by Fermilab, a proactive quality assurance program is in place to ensure accurate monitoring. This program includes quarterly blind testing of the dosimeters used by personnel. During the on-site assessment conducted of Fermilab's external dosimetry program during May 1994, an observation with regard to equipment maintenance and calibration was made: ''calibration personnel should probably review the electron secondary equilibrium needs at various irradiation distances from the 137 Cs irradiation systems'' The majority of the secondary electrons are generated through interactions of the beam with the collimator. Secondary electrons increase the low energy component of the radiation field, increasing the shallow doses measured. For dosimetric purposes, this increase needs to be defined so appropriate corrections to calculations or modifications to the facility can be made. Prompted by this observation, a study was designed to investigate the electron secondary equilibrium in the facility used for the blind testing by determining the dose equivalent as a function of depth in a tissue-equivalent medium. This presentation summarizes the methodology utilized and results of the investigation

Testing taxon tenacity of tortoises: evidence for a geographical selection gradient at a secondary contact zone

Science.gov (United States)

Edwards, Taylor; Berry, Kristin H.; Inman, Richard D.; Esque, Todd C.; Nussear, Kenneth E.; Jones, Cristina A.; Culver, Melanie

2015-01-01

We examined a secondary contact zone between two species of desert tortoise, Gopherus agassizii and G. morafkai. The taxa were isolated from a common ancestor during the formation of the Colorado River (4-8 mya) and are a classic example of allopatric speciation. However, an anomalous population of G. agassizii comes into secondary contact with G. morafkai east of the Colorado River in the Black Mountains of Arizona and provides an opportunity to examine reinforcement of species' boundaries under natural conditions. We sampled 234 tortoises representing G. agassizii in California (n = 103), G. morafkai in Arizona (n = 78), and 53 individuals of undetermined assignment in the contact zone including and surrounding the Black Mountains. We genotyped individuals for 25 STR loci and determined maternal lineage using mtDNA sequence data. We performed multilocus genetic clustering analyses and used multiple statistical methods to detect levels of hybridization. We tested hypotheses about habitat use between G. agassizii and G. morafkai in the region where they co-occur using habitat suitability models. Gopherus agassizii and G. morafkai maintain independent taxonomic identities likely due to ecological niche partitioning, and the maintenance of the hybrid zone is best described by a geographical selection gradient model.

Sound settlement: noise surpasses land cover in explaining breeding habitat selection of secondary cavity-nesting birds.

Science.gov (United States)

Kleist, Nathan J; Guralnick, Robert P; Cruz, Alexander; Francis, Clinton D

2017-01-01

Birds breeding in heterogeneous landscapes select nest sites by cueing in on a variety of factors from landscape features and social information to the presence of natural enemies. We focus on determining the relative impact of anthropogenic noise on nest site occupancy, compared to amount of forest cover, which is known to strongly influence the selection process. We examine chronic, industrial noise from natural gas wells directly measured at the nest box as well as site-averaged noise, using a well-established field experimental system in northwestern New Mexico. We hypothesized that high levels of noise, both at the nest site and in the environment, would decrease nest box occupancy. We set up nest boxes using a geospatially paired control and experimental site design and analyzed four years of occupancy data from four secondary cavity-nesting birds common to the Colorado Plateau. We found different effects of noise and landscape features depending on species, with strong effects of noise observed in breeding habitat selection of Myiarchus cinerascens, the Ash-throated Flycatcher, and Sialia currucoides, the Mountain Bluebird. In contrast, the amount of forest cover less frequently explained habitat selection for those species or had a smaller standardized effect than the acoustic environment. Although forest cover characterization and management is commonly employed by natural resource managers, our results show that characterizing and managing the acoustic environment should be an important tool in protected area management. © 2016 by the Ecological Society of America.

Species selection in secondary wood products: implications for product design and promotion

Science.gov (United States)

Matthew S. Bumgardner; Scott A. Bowe; Scott A. Bowe

2002-01-01

This study investigated the perceptions that people have of several commercially important wood species and determined if word-based and specimen-based evaluations differed. Such knowledge can help secondary wood manufacturers better understand their products and develop more effective design concepts and promotional messages. A sample of more than 250 undergraduate...

Sex selection and restricting abortion and sex determination.

Science.gov (United States)

Zilberberg, Julie

2007-11-01

Sex selection in India and China is fostered by a limiting social structure that disallows women from performing the roles that men perform, and relegates women to a lower status level. Individual parents and individual families benefit concretely from having a son born into the family, while society, and girls and women as a group, are harmed by the widespread practice of sex selection. Sex selection reinforces oppression of women and girls. Sex selection is best addressed by ameliorating the situations of women and girls, increasing their autonomy, and elevating their status in society. One might argue that restricting or prohibiting abortion, prohibiting sex selection, and prohibiting sex determination would eliminate sex selective abortion. But this decreases women's autonomy rather than increases it. Such practices will turn underground. Sex selective infanticide, and slower death by long term neglect, could increase. If abortion is restricted, the burden is placed on women seeking abortions to show that they have a legally acceptable or legitimate reason for a desired abortion, and this seriously limits women's autonomy. Instead of restricting abortion, banning sex selection, and sex determination, it is better to address the practice of sex selection by elevating the status of women and empowering women so that giving birth to a girl is a real and positive option, instead of a detriment to the parents and family as it is currently. But, if a ban on sex selective abortion or a ban on sex determination is indeed instituted, then wider social change promoting women's status in society should be instituted simultaneously.

Spectrophotometric and spectrofluorimetric determination of some drugs containing secondary amino group in bulk drug and dosage forms via derivatization with 7-Chloro-4-Nitrobenzofurazon

Directory of Open Access Journals (Sweden)

Armaan Önal

2011-01-01

Full Text Available Sensitive and selective spectrophotometric and spectrofluorimetric methods have been developed for determination of some drugs such as Pramipexole, Nebivolol, Carvedilol, and Eletriptan, which commonly contain secondary amino group. The subject methods were developed via derivatization of the secondary amino groups with 7-Chloro-4-Nitrobenzofurazon in borate buffer where a yellow colored reaction product was obtained and measured spectrophotometrically or spectrofluorimetrically. Concentration ranges were found as 2.0 to 250 μg mL-1 and 0.1 to 3.0 μg mL-1, for spectrophotometric and spectrofluorimetric study, respectively. The described methods can be easily applied by the quality control laboratories in routine analyses of these drugs in pharmaceutical preparations.

Determination of zirconium by fluoride ion selective electrode

International Nuclear Information System (INIS)

Mahanty, B.N.; Sonar, V.R.; Gaikwad, R.; Raul, S.; Das, D.K.; Prakash, A.; Afzal, Md.; Panakkal, J.P.

2010-01-01

Full text: Zirconium is used in a wide range of applications including nuclear clad, catalytic converters, surgical appliances, metallurgical furnaces, superconductors, ceramics, lamp filaments, anti corrosive alloys and photographical purposes. Irradiation testing of U-Zr and U-Pu-Zr fuel pins has also demonstrated their feasibility as fuel in liquid metal reactors. Different methods that are employed for the determination of zirconium are spectrophotometry, potentiometry, neutron activation analysis and mass spectrometry. Ion-selective electrode (ISE), selective to zirconium ion has been studied for the direct potentiometric measurements of zirconium ions in various samples. In the present work, an indirect method has been employed for the determination of zirconium in zirconium nitrate sample using fluoride ion selective electrode. This method is based on the addition of known excess amount of fluoride ion to react with the zirconium ion to produce zirconium tetra fluoride at about pH 2-3, followed by determination of residual fluoride ion selective electrode. The residual fluoride ion concentrations were determined from the electrode potential data using calibration plot. Subsequently, zirconium ion concentrations were determined from the concentration of consumed fluoride ions. A precision of about 2% (RSD) with the mean recovery of more than 94% has been achieved for the determination of zirconium at the concentration of 4.40 X 10 -3 moles lit -1

An investigation into youth entrepreneurship in selected South ...

African Journals Online (AJOL)

This research paper examines the status of entrepreneurship education in selected South African secondary schools to determine the impact thereof on young learners' attitude towards entrepreneurship and their future plans. It highlights some challenges facing youth entrepreneurship development in Sedibeng secondary ...

The Interaction of Selective Attention and Cognitive Development on Achievement in Nigerian Secondary School Genetics

Science.gov (United States)

Okoye, Namdi N. S.

2009-01-01

The study tried to examine the interaction between two independent variables of selective attention and cognitive development on Achievement in Genetics at the Secondary School level. In looking at the problem of this study three null hypotheses were generated for testing at 0.05 level of significance. Factorial Analysis of Variance design with…

Genetic Diseases and Genetic Determinism Models in French Secondary School Biology Textbooks

Science.gov (United States)

Castera, Jeremy; Bruguiere, Catherine; Clement, Pierre

2008-01-01

The presentation of genetic diseases in French secondary school biology textbooks is analysed to determine the major conceptions taught in the field of human genetics. References to genetic diseases, and the processes by which they are explained (monogeny, polygeny, chromosomal anomaly and environmental influence) are studied in recent French…

Determination of selected azaarenes in water by bonded-phase extraction and liquid chromatography

Science.gov (United States)

Steinheimer, T.R.; Ondrus, M.G.

1986-01-01

A method for the rapid and simple quantitative determination of quinoline, isoquinoline, and five selected three-ring azaarenes in water has been developed. The azaarene fraction is separated from its carbon analogues on n-octadecyl packing material by edition with acidified water/acetonitrile. Concentration as great as 1000-fold is achieved readily. Instrumental analysis involves high-speed liquid chromatography on flexible-walled, wide-bore columns with fluorescence and ultraviolet detection at several wavelengths employing filter photometers in series. Method-validation data is provided as azaarene recovery efficiency from fortified samples. Distilled water, river water, contaminated ground water, and secondary-treatment effluent have been tested. Recoveries at part-per-billion levels are nearly quantitative for the three-ring compounds, but they decrease for quinoline and isoquinoline. ?? 1986 American Chemical Society.

Determination of secondary electron yields from low pressure breakdown

International Nuclear Information System (INIS)

Maric, D; Zivanov, S.; Strinic, A.; Malovic, G.; Djuric, M.; Petrovic, Z. Lj.

2000-01-01

In order to model accurately the secondary yields in gas breakdown and collisional plasmas both the numerous processes discussed in related experiments must be included and also proper determination of γ (E/n) must be provided. In addition to the application of the correct ionization rate it is also essential to include the nonequilibrium region where electrons gain energy and achieve hydrodynamics equilibrium. For lower values of E/n, greater values of γ than those based on the literature data for αn(E/n) have been found, possibly due to existence of the photoelectric effects

Determinants of Secondary School Teachers’ Job Satisfaction in Tanzania

Directory of Open Access Journals (Sweden)

Gilman Jackson Nyamubi

2017-01-01

Full Text Available This study examined teachers’ job satisfaction in Tanzania. It addressed one research question: what factors determine secondary school teachers’ job satisfaction? The study was conducted in eight secondary schools in two regions of Tanzania. It used focus group discussion as the data collection tool. Results show that teachers were satisfied by both monetary and nonmonetary incentives such as community support. They were pleased with fair remuneration packages that related to their labour input, opportunities for career development, a well-defined individual appraisal system, timely promotion, and requisite workplace conditions. The study also showed that teachers’ friendship and cooperation with coworkers and students as well as the respect of community members also enhanced their satisfaction in teaching. Also important to their satisfaction is their students’ success in and after school, which reveals the teachers’ sense of duty and responsibility. Teachers’ job dissatisfaction can lead to their search for other means to gain economically. It is recommended that care should be given to address teachers’ pertinent issues, especially salaries, workplace conditions, and timely promotion, to enhance teachers’ physical and mental attachment to their workplaces.

Application of Monte Carlo method in determination of secondary characteristic X radiation in XFA

International Nuclear Information System (INIS)

Roubicek, P.

1982-01-01

Secondary characteristic radiation is excited by primary radiation from the X-ray tube and by secondary radiation of other elements so that excitations of several orders result. The Monte Carlo method was used to consider all these possibilities and the resulting flux of characteristic radiation was simulated for samples of silicate raw materials. A comparison of the results of these computations with experiments allows to determine the effect of sample preparation on the characteristic radiation flux. (M.D.)

Selective determination of dopamine using quantum-sized gold nanoparticles protected with charge selective ligands

Science.gov (United States)

Kwak, Kyuju; Kumar, S. Senthil; Lee, Dongil

2012-06-01

We report here the selective determination of dopamine (DA) using quantum-sized gold nanoparticles coated with charge selective ligands. Glutathione protected gold nanoparticles (GS-Au25) were synthesized and immobilized into a sol-gel matrix via thiol linkers. The GS-Au25 modified sol-gel electrode was found to show excellent electrocatalytic activity towards the oxidation of DA but no activity towards the oxidation of ascorbic acid. The role of electrostatic charge in the selective electrocatalytic activity of GS-Au25 was verified by voltammetry of redox markers carrying opposite charges. The pH dependent sensitivity for the determination of DA further confirmed the charge screening effect of GS-Au25. Mechanistic investigation revealed that the selectivity is attained by the selective formation of an electrostatic complex between the negatively charged GS-Au25 and DA cation. The GS-Au25 modified sol-gel electrode also showed excellent selectivity for DA in the presence of an interferent, ascorbic acid.We report here the selective determination of dopamine (DA) using quantum-sized gold nanoparticles coated with charge selective ligands. Glutathione protected gold nanoparticles (GS-Au25) were synthesized and immobilized into a sol-gel matrix via thiol linkers. The GS-Au25 modified sol-gel electrode was found to show excellent electrocatalytic activity towards the oxidation of DA but no activity towards the oxidation of ascorbic acid. The role of electrostatic charge in the selective electrocatalytic activity of GS-Au25 was verified by voltammetry of redox markers carrying opposite charges. The pH dependent sensitivity for the determination of DA further confirmed the charge screening effect of GS-Au25. Mechanistic investigation revealed that the selectivity is attained by the selective formation of an electrostatic complex between the negatively charged GS-Au25 and DA cation. The GS-Au25 modified sol-gel electrode also showed excellent selectivity for DA in the

Longevity enhances selection of environmental sex determination.

Science.gov (United States)

Bull, J J; Bulmer, M G

1989-12-01

Environmental sex determination (ESD) is a mechanism in which an individual develops as male or female largely in response to some environmental effect experienced early in life. Its forms range from sex determination by egg incubation temperature in reptiles to sex determination of photoperiod in amphipods. Previous theoretical work as suggested that ESD is favored by natural selection if the fitness consequences of the early environmental experience differ for males and females, so that an individual benefits by being male under some conditions and female under others. A drawback of ESD is that it enables climatic changes to influence the population sex ratio, and such fluctuations select against ESD. This study employed numerical analyses to investigate the balance between these two opposing forces. The negative impact of climatic fluctuations appears to depend greatly on species longevity: substantial between-year fluctuations are of little consequence in selecting against ESD in long-lived species because annual sex ratio fluctuations tend to cancel and thus alter the total population sex ratio only slightly. Thus, if a species is sufficiently long-lived, extreme ESD can be maintained despite only a weak advantage. This result offers one explanation for the failure to demonstrate an advantage for the extreme forms of ESD observed in reptiles.

Determination of B and Li in nuclear materials by secondary-ion mass spectrometry

International Nuclear Information System (INIS)

Eby, R.E.; Christie, W.H.

1981-01-01

Secondary ion mass spectrometry (SIMS) was used to perform mass and isotopic analysis for B and Li in samples that are not readily amenable to more conventional mass spectrometric techniques (e.g., surface ionization, electron impact, etc.). In this paper three specific applications of SIMS analysis to nuclear materials are discussed: first, the quantitative determination of B and its isotopic composition in borosilicate glasses; second, the determination of the isotopic composition of B and Li in irradiated nuclear-grade aluminum oxide/boron carbide composite pellets, and, lastly, the quantitative and isotopic determination of B and Li in highly radioactive solutions of unknown composition

Modeling Student Performance in Mathematics Using Binary Logistic Regression at Selected Secondary Schools a Case Study of Mtwara Municipality and Ilemela District

Science.gov (United States)

Mabula, Salyungu

2015-01-01

This study investigated the performance of secondary school students in Mathematics at the Selected Secondary Schools in Mtwara Municipality and Ilemela District by Absenteeism, Conduct, Type of School and Gender as explanatory Factors. The data used in the study was collected from documented records of 250 form three students with 1:1 gender…

Chromosomal abnormality in patients with secondary amenorrhea.

Science.gov (United States)

Safai, Akbar; Vasei, Mohammad; Attaranzadeh, Armin; Azad, Fariborz; Tabibi, Narjes

2012-04-01

Secondary amenorrhea is a condition in which there is cessation of menses after at least one menstruation. It is a symptom of different diseases, such as hormonal disturbances which range from pituitary to ovarian origin, as well as chromosomal abnormalities. Knowledge of the distinct cause of secondary amenorrhea is of tremendous benefit for the management and monitoring of patients. In this study, we determine the chromosomal abnormalities in patients with secondary amenorrhea in Southwest Iran. We selected 94 patients with secondary amenorrhea who referred to our Cytogenetic Ward from 2004 until 2009. For karyotyping, peripheral blood lymphocyte cultures were set up by conventional technique. In this study, 5.3% (n=5) of patients with secondary amenorrhea presented with chromosomal abnormalities, of which all contained an X element. The chromosomal abnormalities were: i) 45, X (n=1); ii) 47, XXX (n=1); iii) 45, X [13]/ 45, Xi(X)q[17] (n=1);  iv) 45, X[12]/46,X,+mar[12] (n=1); and v) 46,X,del(Xq)(q23q28) (n=1). Our study revealed that some causes of secondary amenorrhea could be due to chromosomal abnormalities. Therefore, cytogenetic studies should be important tests in the evaluation of patients with secondary amenorrhea.

Applications of Qualitative Microanalysis to the Determination of Secondary Species Associated with Uranium

International Nuclear Information System (INIS)

Agrinier, H.

1959-02-01

Microanalytical techniques are described which allow rapid determinations of secondary species associated with uranium. They consist in exposing the constituent elements of the ores by means of characteristic microchemical reactions. Because of their rapidity and the small amount of apparatus needed, these techniques can be used either in the field or in the laboratory. (author) [fr

Impact of Cooperative Learning Approach on Senior Secondary ...

African Journals Online (AJOL)

This research work investigated the impact of cooperative learning approach on the performance of secondary school students in mathematics using some selected secondary schools. It employed one hundred and twenty students selected from the entire population of students offering mathematics at the senior secondary ...

Selectivity determinants of GPCR-G-protein binding

DEFF Research Database (Denmark)

Flock, Tilman; Hauser, Alexander S; Lund, Nadia

2017-01-01

of the G-protein barcode through distinct residues, like multiple keys (receptors) opening the same lock (G protein) using non-identical cuts. Considering the evolutionary history of GPCRs allows the identification of these selectivity-determining residues. These findings lay the foundation...

Selective internal radiation therapy (SIRT) for liver metastases secondary to colorectal adenocarcinoma

International Nuclear Information System (INIS)

Welsh, James S.; Kennedy, Andrew S.; Thomadsen, Bruce

2006-01-01

Introduction: Selective internal radiation therapy (SIRT) is a relatively new commercially available microbrachytherapy technique for treatment of malignant hepatic lesions using 9 Y embedded in resin microspheres, which are infused directly into the hepatic arterial circulation. It is FDA approved for liver metastases secondary to colorectal carcinoma and is under investigation for treatment of other liver malignancies, such as hepatocellular carcinoma and neuroendocrine malignancies. Materials/Methods: A modest number of clinical trials, preclinical animal studies, and dosimetric studies have been reported. Here we review several of the more important results. Results: High doses of beta radiation can be selectively delivered to tumors, resulting in impressive local control and survival rates. Ex vivo analyses have shown that microspheres preferentially cluster around the periphery of tumor nodules with a high tumor:normal tissue ratio of up to 200:1. Toxicity is usually mild, featuring fatigue, anorexia, nausea, abdominal discomfort, and slight elevations of liver function tests. Conclusions: Selective internal radiation therapy represents an effective means of controlling liver metastases from colorectal adenocarcinoma. Clinical trials have demonstrated improved local control of disease and survival with relatively low toxicity. Investigations of SIRT for other hepatic malignancies and in combination with newer chemotherapy agents and targeted biologic therapies are under way or in planning. A well-integrated team involving interventional radiology, nuclear medicine, medical oncology, surgical oncology, medical physics, and radiation oncology is essential for a successful program. Careful selection of patients through the combined expertise of the team can maximize therapeutic efficacy and reduce the potential for adverse effects

Improving the submicro determination of vanadium in natural water using primary-secondary wavelength spectrophotometry

International Nuclear Information System (INIS)

Khongven Gao

1999-01-01

In acidic solution and in the presence of ammonium persulfate, the conventional reaction of vanadium(5) with gallic acid to form an orange complex has been used for the improvement of the determination of trace amounts of vanadium in water by the updated method named primary-secondary wavelength spectrophotometry. The results show that the analytical precision and accuracy were improved and gave higher determination sensitivity than ordinary spectrophotometry. The relative standard deviations were less than 5.6 % [ru

An Empirical Study of Stressors That Impinge on Teachers in Secondary Schools in Swaziland

Science.gov (United States)

Okeke, C. I. O.; Dlamini, Ceasar C.

2013-01-01

This study employed the descriptive-correlation research design to determine whether secondary school teachers experience work-related stress. Participants included 239 teachers selected from schools in the Hhohho region of Swaziland. A questionnaire was used as the instrument to determine the level of work-related stress experienced by these…

Phytochemical profile of morphologically selected yerba-mate progenies

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Alice Teresa Valduga

2016-02-01

Full Text Available ABSTRACT Yerba-mate (Ilex paraguariensis St. Hil is a native South American species. Plant progenies are populations that differ in terms of their productivity, morphology and phytochemical profile. This study aimed to determine the concentration of primary and secondary metabolites, such as antioxidants, in leaves, of yerba-mate progenies selected based on morphological characteristics. We evaluated the centesimal composition of secondary metabolites in the leaves of five yerba-mate plants. Methylxanthines and phenolic compounds were determined by UPLC-PDA, and antioxidant activity by measuring DPPH scavenging. Significant differences were found in centesimal composition and the contents of caffeine, theobromine, rutin and chlorogenic acid, as well as antioxidant activities, in selected progenies. The IC50 values were correlated with the chlorogenic acid levels (r2 = 0.5242 and soluble content (r2 = 0.7686. The morphological characteristics observed in yerba-mate leaves can be used as a tool for plant selection, to obtain matrices with different phytochemical profiles as a genetic material source.

Considerations on scattering and leak radiation for effective determination of secondary shielding in X-rays rooms of megavoltage

International Nuclear Information System (INIS)

Borges, Diogo da S.; Lava, Deise D.; Affonso, Renato R.W.; Moreira, Maria de L.; Guimaraes, Antonio C.F.

2014-01-01

This paper addresses the development of a algorithm capable of analyzing the thickness of the secondary shielding due to the production of secondary beams. The production of this beam requires consideration of scattering angle, as well as factors normally used for screening of medical facilities using radiographic techniques. Besides the beam emanated from scattering radiation, is is necessary to evaluate the contribution of leakage radiation, originating from equipment used for the production of the primary beam. A view of the mutual contribution of these radiation to the formation of the secondary beam has shown the need of using shieldings in adjacent walls of the room. The code was validated by comparison with an example case provided by NCRP-151 Report. In this report calculations for determining the secondary barrier for small angles are presented, that deserves greater attention for shielding and statements related to radiotherapy procedures of Modulated intensity. The results are consistent with those provided in the report, which makes the code can be used as a practical tool for the determination of effective shielding beams of megavoltage X-rays

Determination and removal of antibiotics in secondary effluent using a horizontal subsurface flow constructed wetland.

Science.gov (United States)

Zhang, Chunhui; Ning, Ke; Zhang, Wenwen; Guo, Yuanjie; Chen, Jun; Liang, Chen

2013-04-01

Increased attention is currently being directed towards the potential negative effects of antibiotics and other PPCPs discharged into the aquatic environment via municipal WWTP secondary effluents. A number of analytical methods, such as high performance liquid chromatography technologies, including a high performance liquid chromatography-fluorescence method (HPLC-FLD), high performance liquid chromatography-UV detection method (HPLC-UV) and high performance liquid chromatography-mass spectrometry method (HPLC-MS), have been suggested as determination technologies for antibiotic residues in water. In this study, we implement a HPLC-MS/MS combined method to detect and analyze antibiotics in WWTP secondary effluent and apply a horizontal subsurface flow constructed wetland (CW) as an advanced wastewater treatment for removing antibiotics in the WWTP secondary effluent. The results show that there were 2 macrolides, 2 quinolones and 5 sulfas in WWTP secondary effluent among all the 22 antibiotics considered. After the CW advanced treatment, the concentration removal efficiencies and removal loads of 9 antibiotics were 53-100% and 0.004-0.7307 μg m(-2) per day, respectively.

Automation and Its Funding in the Library Media Centers in Secondary Schools in Georgia: A Survey.

Science.gov (United States)

Baggett, Ann Utsey

This report presents the results of a study whose purpose was to determine what automation is present in the library media centers in Georgia secondary schools and how it has been funded. A three-part questionnaire was sent to the media specialists in 50% of the secondary schools in Georgia, which were randomly selected. The analysis of the…

A Phenomenological Case Study of the Elementary to Secondary Transition for One Female Student Diagnosed with Selective Mutism

Science.gov (United States)

Nashman-Smith, Mona

2017-01-01

Selective mutism (SM) is considered a communication and anxiety disorder that afflicts about 1% of students. The rarity of SM and the isolated cases of this condition has rendered the elementary to secondary school experience for a student with SM difficult to study. Utilizing a qualitative approach, this phenomenological case study examined the…

Determinants of Adolescents' Career Development Competencies in Junior Secondary Schools of South Korea

Science.gov (United States)

Park, Joo-Ho; Rojewski, Jay W.; Lee, In Heok

2018-01-01

More attention is needed on the career development of adolescents, specifically disadvantaged students deemed at risk of school failure. We investigated the determinants on career development competencies of 9th graders in secondary school in South Korea. The data in this study included 394 principals, 6635 students, and the students' parents. Our…

Evaluation of primary and secondary metabolites in selected varieties of potatoes.

Directory of Open Access Journals (Sweden)

Ján Mareček

2016-01-01

Full Text Available The aim of study was to determine primary and secondary metabolites in selected varieties of potatoes. Potatoes (Solanum tuberosum L. are good source of bioactive compounds, mainly phenols as one of the most important components. The chemical composition with reducing sugar, starch, ascorbic acid, total polyphenol and flavonoid content were analyzed in five potato varieties (Agria, Marabel, Red Anna, Picasso, Princess. Values of dry matter content ranged from 20.34 to 23.64%. In terms of tubers storage, its content above 20% is required. The highest level of starch was detected in variety Princess (16.82%. The lowest reducing sugar content was recorded by variety Marabel (0.08%. Similarly, low values reached varieties Princess (0.12%, Agria (0.14 and Red Anna (0.16%. These would be appropriate to use for food processing and for production of fried potato chips or fries. Variety Red Anna reached the highest amount of vitamin C (73.72 mg.kg-1. The lower levels of this vitamin showed tubers of varieties Picasso (35.02 mg.kg-1 and Princess (36.89 mg.kg-1. The antioxidant activity was measured with radical scavenging assays using 1,1-diphenyl-2-picrylhydrazyl (DPPH radical as well as phosphomolybdenic assay. Potato varieties contained high levels of total polyphenols (0.474 – 1.550 mg GAE per dry weight and flavonoids (1.407 – 15.933 μg QE per dry weight. The consumption of potatoes can provide nutritional value along with antioxidant potential that can be helpful for proper functioning of the body physiological systems. Statistical evaluation by the single factor analysis of variance detected high significant impact of variety on the content of all the analytical parameters in evaluated varieties of potato tubers. Normal 0 21 false false false SK X-NONE X-NONE

Knowledge of adolescents completing secondary schools concerning genetically modified organisms (GMO)

OpenAIRE

Florek-Łuszczki Magdalena; Lachowski Stanisław; Chmielewski Jarosław; Jurkiewicz Anna

2016-01-01

The objective of the conducted analyses is the evaluation of the level of knowledge concerning the scope of problems related with genetically modified organism (GMO) amongst adolescents completing secondary schools and the determination of the relationship between the level of this knowledge and the selected demographic traits of the adolescents examined.

Function-related Secondary User Needs and Secondary Data

African Journals Online (AJOL)

Riette Ruthven

basis of both a critical analysis of the theory and an examination of selected data types .... (2) "Secondary needs related to the user's linguistic and subject-specific ... understand the Afrikaans word skepe needs to know that skepe is the plural.

Secondary hypertension: the ways of management.

Science.gov (United States)

Rossi, Gian P; Seccia, Teresa M; Pessina, Achille C

2010-11-01

The prevalence of secondary hypertension is lower than that of primary (essential) hypertension, but it is likely that it has been underestimated because appropriate tests were not generally performed. Hence, before embarking on a search for secondary hypertension physicians are generally advised to select populations of patients with a high pre-test probability of secondary forms of hypertension in order to maximize the positive predictive value and the gain in "ruling in" of the diagnostic tests. Based on updated information on prevalence and pathophysiology we herein critically review the general diagnostic strategy and the management of the main forms of secondary hypertension. In particular, strategies for identifying primary aldosteronism, the most frequent form of endocrine secondary hypertension, and for determining its unilateral or bilateral causes are discussed in details, because of the differences of treatment that requires adrenalectomy in the unilateral forms and mineralocorticoid receptor blockade in the bilateral forms. The tests available for the diagnosing pheochromocytoma (pheo), which is much rarer but extremely important to identify, as it can be fatal if unrecognized are also discussed, with emphasis on the recent developments in genetic testing. Renovascular hypertension is also a common curable form of hypertension, which should be identified as early as possible to avoid the onset of cardiovascular target organ damage and events, is also discussed.

Problem-Based Instructional Strategy and Numerical Ability as Determinants of Senior Secondary Achievement in Mathematics

Science.gov (United States)

Badru, Ademola K.

2016-01-01

The study investigated Problem-based Instructional Strategy and Numerical ability as determinants of Senior Secondary Achievement in Mathematics. This study used 4 x 2 x 2 non-randomised control group Pretest-Posttest Quasi-experimental Factorial design. It consisted of two independent variables (treatment and Numerical ability) and one moderating…

Instructional Methods and Students' End of Term Achievement in Biology in Selected Secondary Schools in Sokoto Metropolis, Sokoto State Nigeria

Science.gov (United States)

Shamsuddeen, Abdulrahman; Amina, Hassan

2016-01-01

This study investigated the Correlation between instructional methods and students end of term achievement in Biology in selected secondary schools in Sokoto Metropolis, Sokoto State Nigeria. The study addressed three Specific objectives. To examine the relationship between; Cooperative learning methods, guided discovery, Simulation Method and…

Determining Student Internet Addiction Levels in Secondary Education and the Factors that Affect It

Directory of Open Access Journals (Sweden)

Fezile Ozdamli

2013-05-01

Full Text Available The aim of this research is to determine the level of internet addiction on the part of students in secondary education in North Cyprus and the factors that affect it. In this research, a survey method which provides a general universal judgment was used to determine the level of internet addiction on the part of such students. It has been found that 59.9% of the students are at low of becoming internet addicts, 20.7% of them are in the high risk category, 13.5% face no risk of addiction, while 5.9% are internet addicts. It was determined that as students’ internet usage hours increase, the risk of addiction increases.

Hydrogen determination using secondary processes of recoil proton interaction with sample material

International Nuclear Information System (INIS)

Muminov, V.A.; Khajdarov, R.A.; Navalikhin, L.V.; Pardaev, Eh.

1980-01-01

Possibilities of hydrogen content determination in different materials according to secondary processes of interaction of recoil protons(irradiation in the field of fast neutrons) with sample material resulting in the appearance of characteristic X-ray irradiation are studied. Excitated irradiation is recorded with a detector placed in the protective screen and located at a certain distance from the object analyzed and neutron source. The method is tested taking as an example analysis of bromine-containing samples (30% Br, 0.5% H) and tungsten dioxide. The determination limit of hydrogen content constitutes 0.05% at confidence coefficient of 0.9. Neutron flux constituted 10 3 neutrons/cm 2 xs, the time of measurement being 15-20 minutes, the distance from the sample to the detector being 12-15 cm [ru

Knowledge of adolescents completing secondary schools concerning genetically modified organisms (GMO

Directory of Open Access Journals (Sweden)

Florek-Łuszczki Magdalena

2016-06-01

Full Text Available The objective of the conducted analyses is the evaluation of the level of knowledge concerning the scope of problems related with genetically modified organism (GMO amongst adolescents completing secondary schools and the determination of the relationship between the level of this knowledge and the selected demographic traits of the adolescents examined.

Tracing the social gradient in the health of Canadians: primary and secondary determinants.

Science.gov (United States)

Kosteniuk, Julie G; Dickinson, Harley D

2003-07-01

The social gradient in heath refers to the fact that inequalities in population health status are related to inequalities in social status. This study advances and tests a model of the relationships between what we term primary and secondary determinants of the social gradient in health. The primary determinants of health include socioeconomic and demographic indicators. Secondary determinants include stressors, control, self-esteem, social support, and social involvement. Health status is indicated by measures of physical health, self-reported health status, and mental distress. Data are taken from the Canadian National Population Health (NPH) Survey (1994-1995). The study sample consists of 7720 men and 9269 women 15 to over 80 years of age. Using path analysis, we found that higher household income, being retired and growing older are significantly associated with lower stressor levels. Higher stressor levels are associated with lower levels of control, self-esteem, and social support. Higher income Canadians experience greater levels of control and social support, while older Canadians experience lower rates of social support but higher rates of social involvement. Being employed and caring for one's family are positively associated with better physical and self-reported health status. Higher household income, being retired, and aging are associated with better physical health and lower mental distress when accounting for their role in lowering stressor levels and bolstering control, self-esteem, social support, and social involvement. Replicating this study with future samples of the NPH Survey should be of benefit in ascertaining whether the social gradient in Canadians' health status shows signs of declining.

Determination of Secondary Encasement Pipe Design Pressure

Energy Technology Data Exchange (ETDEWEB)

TEDESCHI, A.R.

2000-10-26

This document published results of iterative calculations for maximum tank farm transfer secondary pipe (encasement) pressure upon failure of the primary pipe. The maximum pressure was calculated from a primary pipe guillotine break. Results show encasement pipeline design or testing pressures can be significantly lower than primary pipe pressure criteria.

Paricalcitol for secondary hyperparathyroidism in renal transplantation.

Science.gov (United States)

Trillini, Matias; Cortinovis, Monica; Ruggenenti, Piero; Reyes Loaeza, Jorge; Courville, Karen; Ferrer-Siles, Claudia; Prandini, Silvia; Gaspari, Flavio; Cannata, Antonio; Villa, Alessandro; Perna, Annalisa; Gotti, Eliana; Caruso, Maria Rosa; Martinetti, Davide; Remuzzi, Giuseppe; Perico, Norberto

2015-05-01

Secondary hyperparathyroidism contributes to post-transplant CKD mineral and bone disorder. Paricalcitol, a selective vitamin D receptor activator, decreased serum parathyroid hormone levels and proteinuria in patients with secondary hyperparathyroidism. This single-center, prospective, randomized, crossover, open-label study compared the effect of 6-month treatment with paricalcitol (1 μg/d for 3 months and then uptitrated to 2 µg/d if tolerated) or nonparicalcitol therapy on serum parathyroid hormone levels (primary outcome), mineral metabolism, and proteinuria in 43 consenting recipients of renal transplants with secondary hyperparathyroidism. Participants were randomized 1:1 according to a computer-generated sequence. Compared with baseline, median (interquartile range) serum parathyroid hormone levels significantly declined on paricalcitol from 115.6 (94.8-152.0) to 63.3 (52.0-79.7) pg/ml (Psecondary hyperparathyroidism. Long-term studies are needed to monitor directly measured GFR, ensure that the bone remodeling and mineral effects are sustained, and determine if the reduction in proteinuria improves renal and cardiovascular outcomes. Copyright © 2015 by the American Society of Nephrology.

A meta-selective C-H borylation directed by a secondary interaction between ligand and substrate

Science.gov (United States)

Kuninobu, Yoichiro; Ida, Haruka; Nishi, Mitsumi; Kanai, Motomu

2015-09-01

Regioselective C-H bond transformations are potentially the most efficient method for the synthesis of organic molecules. However, the presence of many C-H bonds in organic molecules and the high activation barrier for these reactions make these transformations difficult. Directing groups in the reaction substrate are often used to control regioselectivity, which has been especially successful for the ortho-selective functionalization of aromatic substrates. Here, we describe an iridium-catalysed meta-selective C-H borylation of aromatic compounds using a newly designed catalytic system. The bipyridine-derived ligand that binds iridium contains a pendant urea moiety. A secondary interaction between this urea and a hydrogen-bond acceptor in the substrate places the iridium in close proximity to the meta-C-H bond and thus controls the regioselectivity. 1H NMR studies and control experiments support the participation of hydrogen bonds in inducing regioselectivity. Reversible direction of the catalyst through hydrogen bonds is a versatile concept for regioselective C-H transformations.

Job satisfaction among urban secondary-school teachers in Namibia

Directory of Open Access Journals (Sweden)

Evy George

2008-05-01

Full Text Available An exploratory study on the role of extrinsic and intrinsic factors in determining job satisfaction amongst urban secondary-school teachers in Namibia was undertaken. Biographical variables pertaining to the teachers' gender, age, marital status, school resources, teaching experience, academic qualifications, and rank were investigated to determine whether these had any significant relevance, or made any notable contribution, to the level of job satisfaction experienced. Also, the correlation between burnout and job satisfaction was investigated to determine the extent to which these two factors are related. A sample of 337 secondary-school teachers randomly selected from 17 government schools, in the Windhoek region of Namibia, voluntarily participated in the study. Results showed significant levels of dissatisfaction pertaining to intrinsic factors of work and, more especially, those factors relating to school area and rank. A significant correlation between levels of burnout and job satisfaction was found, particularly in respect of emotional exhaustion and depersonalization, which were shown to correlate with low levels of job satisfaction. Limitations and recommendations pertaining to the study are discussed.

Syn-Selective Synthesis of β-Branched α-Amino Acids by Alkylation of Glycine-Derived Imines with Secondary Sulfonates.

Science.gov (United States)

Lou, Sha; McKenna, Grace M; Tymonko, Steven A; Ramirez, Antonio; Benkovics, Tamas; Conlon, David A; González-Bobes, Francisco

2015-10-16

A syn-selective synthesis of β-branched α-amino acids has been developed based on the alkylation of glycine imine esters with secondary sulfonates. The potassium counterion for the enolate, the solvent, and the leaving group on the electrophile were key levers to maximize the diasteroselectivity of the alkylation. The optimized conditions enabled a straightforward preparation of a number of β-branched α-amino acids that can be challenging to obtain.

Non-Resident Fathers' Relationships with Their Secondary School Age Children: Determinants and Children's Mental Health Outcomes

Science.gov (United States)

Flouri, Eirini

2006-01-01

Data from 520 British secondary school age children were used to explore determinants of and mental health outcomes (measured with the Strengths and Difficulties Questionnaire) from their non-resident fathers' relationships (child-reported father's involvement and frequency of contact) with them. Frequency of contact was negatively related to time…

Skills among Teachers in Selected Public Secondary School ...

African Journals Online (AJOL)

The study examined the availability of ICT facilities and skills of secondary school teachers in Zaria Metropolis in Kaduna State, Nigeria. Two objectives were developed to guide the study. Five schools were surveyed. Two separate questionnaires was developed, one for ICT facilities and are administered to head of ICTs in ...

Phenomenon of primary and secondary extinction in textured material

International Nuclear Information System (INIS)

Kryshtab, T.G.; Palacios G, J.; Mazin, M.O.

2002-01-01

A new X-ray diffraction method is proposed for a more exact calculation of pole figures to determine the crystallite orientation distribution function (CODF) in textured materials, by the introduction of a correction of the integrated intensity of the diffracted beam due to the phenomenon of extinction. Besides, for the case of a symmetrical Bragg reflection from an ''infinitely thick'' flat parallel plate textured sample a simple solution is developed for the problem of separation and determination of primary and secondary extinction parameters, which can be present simultaneously. The determination of these parameters gives additional information about crystallite structure and allows us to evaluate the average subgrains size and their disorientation, respectively. In this work according to the dynamic diffraction theory, it is shown that the extinction length, which is directly connected with the phenomenon of primary extinction, in the Bragg geometry for σ polarization (perpendicular) is independent on the wavelength used for a given reflection. On the other hand, the additional contribution from secondary extinction depends on X-ray wavelength due to the change of effective absorption coefficient. Considering this fact, the calculations of pole density and the parameters of primary and secondary extinction are performed using the same strong reflection for two different wavelengths and, for one of these wavelengths, a second order of reflection. For confirmation of the proposed method a partially cold rolled aluminium sample and an aluminium powder standard sample were measured. The corrected pole densities, the values of primary and secondary extinction and the average sizes of perfect coherent areas and average angle of disorientation of subgrains in the selected directions were obtained. The obtained results show that the precise X-ray diffraction characterization of textured materials requires the consideration, in general, of primary as well as secondary

Potential of select intermediate-volatility organic compounds and consumer products for secondary organic aerosol and ozone formation under relevant urban conditions

Science.gov (United States)

Li, Weihua; Li, Lijie; Chen, Chia-li; Kacarab, Mary; Peng, Weihan; Price, Derek; Xu, Jin; Cocker, David R.

2018-04-01

Emissions of certain low vapor pressure-volatile organic compounds (LVP-VOCs) are considered exempt to volatile organic compounds (VOC) regulations due to their low evaporation rates. However, these compounds may still play a role in ambient secondary organic aerosol (SOA) and ozone formation. The LVP-VOCs selected for this work are categorized as intermediate-volatility organic compounds (IVOCs) according to their vapor pressures and molecular formulas. In this study, the evaporation rates of 14 select IVOCs are investigated with half of them losing more than 95% of their mass in less than one month. Further, SOA and ozone formation are presented from 11 select IVOCs and 5 IVOC-containing generic consumer products under atmospherically relevant conditions using varying radical sources (NOx and/or H2O2) and a surrogate reactive organic gas (ROG) mixture. Benzyl alcohol (0.41), n-heptadecane (0.38), and diethylene glycol monobutyl ether (0.16) are determined to have SOA yields greater than 0.1 in the presence of NOx and a surrogate urban hydrocarbon mixture. IVOCs also influence ozone formation from the surrogate urban mixture by impacting radical levels and NOx availability. The addition of lab created generic consumer products has a weak influence on ozone formation from the surrogate mixture but strongly affects SOA formation. The overall SOA and ozone formation of the generic consumer products could not be explained solely by the results of the pure IVOC experiments.

Reflection after teaching a lesson: Experiences of secondary school science teachers

Science.gov (United States)

Halstead, Melissa A.

Secondary science teachers spend most of their time planning, collaborating, and teaching, but spend little time reflecting after teaching a single lesson. The theoretical framework of the adult learning theory and the transformative learning theory was the basis of this study. This qualitative research study was conducted to understand the reflective experiences of secondary science educators after teaching a single or several lessons. The collection of data consisted of interviews from a group of purposefully selected secondary science teachers who met the criteria set forth by the researcher. Through a qualitative analysis of interviews and field notes, the researcher determined that the secondary science teachers in this study shared similar as well as different experiences regarding collaborative and individual reflection after teaching a single or several lessons. The findings from this study also suggested that secondary science educators prefer to collaboratively reflect and then reflect alone to allow for further thought. Additionally, a supportive school culture increases the secondary science teacher’s desire to engage in collaborative as well as individual reflection. The information from this study could be used to close the gaps that exist in the teacher professional development programs.

Threshold Based Opportunistic Scheduling of Secondary Users in Underlay Cognitive Radio Networks

KAUST Repository

Song, Yao

2011-12-01

In underlay cognitive radio networks, secondary users can share the spectrum with primary users as long as the interference caused by the secondary users to primary users is below a certain predetermined threshold. It is reasonable to assume that there is always a large pool of secondary users trying to access the channel, which can be occupied by only one secondary user at a given time. As a result, a multi-user scheduling problem arises among the secondary users. In this thesis, by manipulating basic schemes based on selective multi-user diversity, normalized thresholding, transmission power control, and opportunistic round robin, we propose and analyze eight scheduling schemes of secondary users in an underlay cognitive radio set-up. The system performance of these schemes is quantified by using various performance metrics such as the average system capacity, normalized average feedback load, scheduling outage probability, and system fairness of access. In our proposed schemes, the best user out of all the secondary users in the system is picked to transmit at each given time slot in order to maximize the average system capacity. Two thresholds are used in the two rounds of the selection process to determine the best user. The first threshold is raised by the power constraint from the primary user. The second threshold, which can be adjusted by us, is introduced to reduce the feedback load. The overall system performance is therefore dependent on the choice of these two thresholds and the number of users in the system given the channel conditions for all the users. In this thesis, by deriving analytical formulas and presenting numerical examples, we try to provide insights of the relationship between the performance metrics and the involved parameters including two selection thresholds and the number of active users in the system, in an effort to maximize the average system capacity as well as satisfy the requirements of scheduling outage probability and

Are Korean secondary school girls physically active during leisure time?

Science.gov (United States)

Cho, Minhaeng; Kwon, Wook-Dong; Jeon, Yong-Bae

2010-03-01

Our aims in this study were to identify the types of physical activity during leisure time and to determine if Korean secondary school girls participate in enough physical activity during leisure time to promote health. Of the 1,088 girls randomly selected by a multistaged cluster sampling technique, 705 girls completed questionnaires. Seventy-five percent of Korean secondary school girls spent time on individualized or noncompetitive activities, and 88.3% of them were classified into underactive and inactive levels with no gained health benefits during leisure time. No significant differences were observed in the physical activity levels between middle school girls and high school girls. The results of this study may be explained by the lack of perceived appropriateness for secondary school girls' participation in physical activity, which traditionally did not favor them participating in dynamic physical activities and sufficient physical activity level to gain health benefits.

Separation and selective determination of molybdenum with sodiumthiosulfate and ethylacetate

International Nuclear Information System (INIS)

Hainberger, L.; de Oliveira Andrade, W.

1982-01-01

A sensitive and selective method of spectrophotometric determination of molybdenum is described. Molybdenum is extracted to more than 97%. Lambert-Beer's law is obeyed between 0.35 and 30μg/10ml of the used aqueous solution. 43 ions concerning their interference are studied. The method was used to determine the content of molybdenum in black beans. (Author)

Selective extraction-photometric determination of cadmium by basic dyes

Energy Technology Data Exchange (ETDEWEB)

Kish, P P; Balog, J S [Uzhgorodskij Gosudarstvennyj Univ. (Ukrainian SSR)

1979-12-01

Two variants of selective extraction-photometric determination of cadmium with basic dyes have been developed. In the first one, cadmium is extracted as the iodide by a tributyl phosphate solution in benzene from aqueous solutions containing 0.1 M KI (pH 6-10). Then the cadmium is transformed into a coloured ion associate by treatment of the extracts with Malachite Green in the presence of iodide ions. In the second case, the extract is equilibrated with an equeous solutions of Rhodamine B in the presence of KBr. In this variant, the cadmium is transformed into an anionic iodide-bromide complex which reacts with Rhodamine B cations to form an ion associate. Procedures have been developed of selective extraction-photometric determination of cadmium in sulphur, indium-gallium and zinc concentrates, Zn-As-Cd-Se and Zn-As-Cd-Te films, Cd-S-In and Ga-Sb-Cd-Te alloys.

Characteristics and generation of secondary jets and secondary gigantic jets

Science.gov (United States)

Lee, Li-Jou; Huang, Sung-Ming; Chou, Jung-Kung; Kuo, Cheng-Ling; Chen, Alfred B.; Su, Han-Tzong; Hsu, Rue-Rou; Frey, Harald U.; Takahashi, Yukihiro; Lee, Lou-Chuang

2012-06-01

Secondary transient luminous events (TLEs) recorded by the ISUAL-FORMOSAT2 mission can either be secondary jets or secondary gigantic jets (GJs), depending on their terminal altitudes. The secondary jets emerge from the cloud top beneath the preceding sprites and extend upward to the base of the sprites at ˜50 km. The secondary jets likely are negative electric discharges with vertically straight luminous columns, morphologically resembling the trailing jet of the type-I GJs. The number of luminous columns in a secondary jet seems to be affected by the size of the effective capacitor plate formed near the base of the preceding sprites and the charge distribution left behind by the sprite-inducing positive cloud-to-ground discharges. The secondary GJs originate from the cloud top under the shielding area of the preceding sprites, and develop upward to reach the lower ionosphere at ˜90 km. The observed morphology of the secondary GJs can either be the curvy shifted secondary GJs extending outside the region occupied by the preceding sprites or the straight pop-through secondary GJs developing through the center of the preceding circular sprites. A key factor in determining the terminal height of the secondary TLEs appears to be the local ionosphere boundary height that established by the preceding sprites. The abundance and the distribution of the negative charge in the thundercloud following the sprite-inducing positive cloud-to-ground discharges may play important role in the generation of the secondary TLEs.

SMOKING HABITS AMONG SECONDARY SCHOOL STUDENTS IN ...

African Journals Online (AJOL)

SMOKING HABITS AMONG SECONDARY SCHOOL STUDENTS IN SELECTED DISTRICTS IN ZIMBABWE. ... Journal of Child and Adolescent Mental Health ... Objective To examine the relationship between smoking habits and indicators of socioeconomic status, the urban/rural dimension and gender among secondary ...

Integrated Analysis Seismic Inversion and Rockphysics for Determining Secondary Porosity Distribution of Carbonate Reservoir at “FR” Field

Science.gov (United States)

Rosid, M. S.; Augusta, F. F.; Haidar, M. W.

2018-05-01

In general, carbonate secondary pore structure is very complex due to the significant diagenesis process. Therefore, the determination of carbonate secondary pore types is an important factor which is related to study of production. This paper mainly deals not only to figure out the secondary pores types, but also to predict the distribution of the secondary pore types of carbonate reservoir. We apply Differential Effective Medium (DEM) for analyzing pore types of carbonate rocks. The input parameter of DEM inclusion model is fraction of porosity and the output parameters are bulk moduli and shear moduli as a function of porosity, which is used as input parameter for creating Vp and Vs modelling. We also apply seismic post-stack inversion technique that is used to map the pore type distribution from 3D seismic data. Afterward, we create porosity cube which is better to use geostatistical method due to the complexity of carbonate reservoir. Thus, the results of this study might show the secondary porosity distribution of carbonate reservoir at “FR” field. In this case, North – Northwest of study area are dominated by interparticle pores and crack pores. Hence, that area has highest permeability that hydrocarbon can be more accumulated.

Does public health system provide adequate financial risk protection to its clients? Out of pocket expenditure on inpatient care at secondary level public health institutions: Causes and determinants in an eastern Indian state.

Science.gov (United States)

Rout, Sarit Kumar; Choudhury, Sarmistha

2018-02-09

This study is undertaken to estimate the out of pocket expenditure (OOPE) for various diseases and its determinants at secondary level public health facilities in Odisha. A cross-sectional survey was conducted among the inpatients utilising secondary level public health facilities in the 2 districts of Odisha. More than 80% of the inpatients were selected conveniently, and data on OOPE and socioeconomic status of patients were collected. The OOPE was estimated separately on surgery, nonsurgery, and child birth conditions. Ordinary least square regression models were developed to explain the factors determining OOPE. The mean OOPE for the secondary care facility was Indian National Rupee 3136.14, (95% CI: 2869.08-3403.19), of which, Indian National Rupee 1622.79 (95% CI: 1462.70-1782.89) was on medicine constituting 79% of total medical expenditure. The mean OOPE on surgery was highest followed by nonsurgery and child birth conditions. The OOPE is mainly influenced by caste and educational status of patients as revealed by the regression results. With increase in social status, the OOPE increases and the results are statistically significant. This evidence should be used to design financial strategies to reduce OOPE at secondary care public health facilities, which is largely due to medicine, diagnostic services, and transport expenditure. Efforts should be made to protect the interest of the poor, who utilise public health facility in a low resource setting in India. Copyright © 2018 John Wiley & Sons, Ltd.

Optical wavelength selection for portable hemoglobin determination by near-infrared spectroscopy method

Science.gov (United States)

Tian, Han; Li, Ming; Wang, Yue; Sheng, Dinggao; Liu, Jun; Zhang, Linna

2017-11-01

Hemoglobin concentration is commonly used in clinical medicine to diagnose anemia, identify bleeding, and manage red blood cell transfusions. The golden standard method for determining hemoglobin concentration in blood requires reagent. Spectral methods were advantageous at fast and non-reagent measurement. However, model calibration with full spectrum is time-consuming. Moreover, it is necessary to use a few variables considering size and cost of instrumentation, especially for a portable biomedical instrument. This study presents different wavelength selection methods for optical wavelengths for total hemoglobin concentration determination in whole blood. The results showed that modelling using only two wavelengths combination (1143 nm, 1298 nm) can keep on the fine predictability with full spectrum. It appears that the proper selection of optical wavelengths can be more effective than using the whole spectra for determination hemoglobin in whole blood. We also discussed the influence of water absorptivity on the wavelength selection. This research provides valuable references for designing portable NIR instruments determining hemoglobin concentration, and may provide some experience for noninvasive hemoglobin measurement by NIR methods.

Buccinator sandwich pushback: a new technique for treatment of secondary velopharyngeal incompetence.

Science.gov (United States)

Hill, C; Hayden, C; Riaz, M; Leonard, A G

2004-05-01

A small percentage of patients have inadequate velopharyngeal closure, or secondary velopharyngeal incompetence, following primary palatoplasty. Use of the buccinator musculomucosal flap has been described for primary palate repair with lengthening, but its use in secondary palate lengthening for the correction of insufficient velopharyngeal closure has not been described. This study presents the results of a series of patients who had correction of secondary velopharyngeal incompetence using bilateral buccinator musculomucosal flaps used as a sandwich. In this prospective study between 1995 and 1998, a group of 16 patients with insufficient velopharyngeal closure as determined by speech assessment and videoradiography were selected. Nasopharyngoscopy was carried out in addition in a number of cases. Case selection was a result of these investigations and clinical examination in which the major factor in velopharyngeal insufficiency was determined to be short palatal length. The patients underwent palate lengthening using bilateral buccinator musculomucosal flaps as a sandwich. All patients were assessed 6 months postoperatively. The operative technique, postoperative course, and recorded postoperative complications including partial/total flap necrosis and residual velopharyngeal insufficiency were evaluated. Preoperative and postoperative speech samples were rated by an independent speech therapist. Ninety-three percent (15 of 16) had a significant improvement in velopharyngeal insufficiency, and 14 patients had no hypernasality postoperatively. Both cases of persistent mild hypernasality had had a recognized postoperative complication. The sandwich pushback technique for the correction of persistent velopharyngeal incompetence was successful in achieving good speech results.

An Analysis of Determinants of Recruitment and Selection Outsourcing Implementation

Directory of Open Access Journals (Sweden)

Jana Cocuľová

2015-01-01

Full Text Available In order for the companies to maintain their positions in the current market, they are forced to find new opportunities and ways to streamline their operations. One of such options for the company is outsourcing, which is the subject of this paper. Given the increasing trend of outsourcing in human resource management, the article deals specifically with the issue of outsourcing of selected human resource (HR activity – the recruitment and selection process (R & S. The main goal of the research study is to establish a set of determinants of the success of implementation of R & S outsourcing. The research was carried out by using a questionnaire survey from February 2013 as the primary data source. Questionnaires were distributed to a sample of organizations operating in Slovakia. In order to achieve the research objective, six hypotheses have been contested by correlation analysis and Mann Whitney U test, while in five cases statistically significant correlation between selected determinants and the perceived success of the outsourcing implementation have been confirmed.

Influence of Selected Factors on the Implementation of Information and Communication Technology Policy in Public Secondary Schools in Naivasha Sub-County, Kenya

Science.gov (United States)

Francis, Njoroge Ngugi; Ngugi, Margaret; Kinzi, Joab

2017-01-01

The aim of this study was to examine the influence of selected factors on implementation of Information and Communication Technology in public secondary schools in Naivasha sub-county, Kenya. The study investigated whether the ICT infrastructural cost, schools' visions, and teachers' ICT skills hinder effective implementation of ICT policy in…

Determining the productivity of frontal-selective excavation equipment

Energy Technology Data Exchange (ETDEWEB)

Baikenzhin, A E; Ermekov, T E

1979-01-01

The engineering parameters of the VMF-2 frontal-selective excavation machine are given. Calculation formulae are given for determining the feed speed of the working tool relative to the difference in the motion of the arm of the working tool and the feed speed of the hydraulic jack lifter. A methodology is developed for calculating the productivity of the excavator depending on various engineering conditions, accounting for modifications in its design.

A Note on the Determination of "Acceptable" Performance in Thorndike's Standard of Fair Selection.

Science.gov (United States)

Brown, Charles

1980-01-01

The determination of acceptable performance in Thorndike's constant ratio standard of fair selection is considered. It is shown that suitable choice of acceptable performance can make any minority-majority selection disparity consistent with Thorndike's standard. A rule for determining acceptable performance which avoids the Petersen-Novick…

Determinants of Smartphone Selection: An Application of the University Students

Directory of Open Access Journals (Sweden)

Halim TATLI

2015-12-01

Full Text Available In this study, we aimed to identify the factors that impact on smartphone selection of university students. In this context, the data is obtained from a survey which is conducted to students that are studying in Bingöl University. This questionnaire was administered to 400 students in the November-October 2014. Student’s smartphone selection response variable, the logarithm of age, the logarithm of income and logarithm of the scores of the students' perspective on smart phone is taken as an explanatory variable. In the analysis were used logistic regression. The estimated results of logistic regression analysis; logarithm of the scores of the students' perspective on smart phone and the the logarithm of income was be found to increase the likelihood of smartphone selection in a meaningful way. Between the logarithm of age and smartphone selection was not found to be significant relationship. The results of the study, showed that the major determinants of smartphone selection monthly income and students' perspective on smartphones.

Nonmathematical models for evolution of altruism, and for group selection (peck order-territoriality-ant colony-dual-determinant model-tri-determinant model).

Science.gov (United States)

Darlington, P J

1972-02-01

Mathematical biologists have failed to produce a satisfactory general model for evolution of altruism, i.e., of behaviors by which "altruists" benefit other individuals but not themselves; kin selection does not seem to be a sufficient explanation of nonreciprocal altruism. Nonmathematical (but mathematically acceptable) models are now proposed for evolution of negative altruism in dual-determinant and of positive altruism in tri-determinant systems. Peck orders, territorial systems, and an ant society are analyzed as examples. In all models, evolution is primarily by individual selection, probably supplemented by group selection. Group selection is differential extinction of populations. It can act only on populations preformed by selection at the individual level, but can either cancel individual selective trends (effecting evolutionary homeostasis) or supplement them; its supplementary effect is probably increasingly important in the evolution of increasingly organized populations.

Effect of keywords assignment on secondary information processing and notice on their selection and description

International Nuclear Information System (INIS)

Mishima, Yoshitsugu; Oi, Shoichi; Ebinuma, Yukio.

1976-01-01

Completed are the observation and analysis which have been made on author-assigned keywords to his paper by the Special Committee on Nuclear Documentation in cooperation with the INIS National Center. The keywords must be the most suitable information items in principle for a brief representation of the paper. Each of the keywords is a title-augmentative term, capable of structuring a very short summary. Consequently, it may be possible to transfer them easily to descriptors in every secondary information system. Keywords cited in the two journals of the Atomic Energy Society of Japan are considerably effective in general to get a high quality of indexing and a subsequent high quality of information retrieval, because of both the indexing consistency of 66% and the hit retrieval consistency of 75% in the INIS. On the other hand, it is stressed that the keywords should be selected from the terms in title and abstract of the paper except for short notes. Resulting from the experience in checking of the keywords, a guideline for their selection and description are proposed over eight items on trial so that more adequate assignment can be uniformly attained by all authors concerned. (auth.)

The relationship between type of secondary education and subject choice with technically oriented aptitudes for automotive operators

Directory of Open Access Journals (Sweden)

Juliet I. Puchert

2017-10-01

Full Text Available Orientation: The central theme of this study attends to the role of secondary education in relation to two broad categories of specific aptitudes (psychomotor and spatial abilities. Utilising type of secondary education (incorporating subject choice could be a crucial selection mechanism for high-volume, entry-level technical positions. Research purpose: The objective of this research was to investigate whether the type of secondary education (incorporating subject choice could be used as a proxy for psychomotor (dexterity and coordination and/or spatial (ability to mentally assemble representations and spatial perception 2-D and 3-D aptitudes in the selection of operators for an automotive plant in South Africa. Motivation for the study: The motivation for this study arose from the evident gap in academic literature as well as the selection needs of the automotive industry. Research design, approach and method: A quantitative approach with a cross-sectional research design was used with a convenience sample (n = 1566 of work-seeking applicants for automotive operator positions in South Africa. These applicants completed a biographical questionnaire and five sub-tests from the Trade Aptitude Test Battery. The Chi-square test was used to determine the association between form of Grade 12 qualification and selected technical aptitudes. Main findings: Statistically and practically significant relationships were found between type of secondary education (incorporating subject choice, eye–hand coordination and spatial visualisation. Broad performance levels in the five aptitude instruments employed in this study were significantly associated with the type of matriculation certificate held by applicants. Specifically, types of secondary education that included mathematics and/or science as subjects were associated with higher levels of performance in the five specific aptitudes. Practical/managerial implications: The type of secondary education

Optimization of Cognitive Radio Secondary Information Gathering Station Positioning and Operating Channel Selection for IoT Sensor Networks

Directory of Open Access Journals (Sweden)

Jinyi Wen

2018-01-01

Full Text Available The Internet of Things (IoT is the interconnection of different objects through the internet using different communication technologies. The objects are equipped with sensors and communications modules. The cognitive radio network is a key technique for the IoT and can effectively address spectrum-related issues for IoT applications. In our paper, a novel method for IoT sensor networks is proposed to obtain the optimal positions of secondary information gathering stations (SIGSs and to select the optimal operating channel. Our objective is to maximize secondary system capacity while protecting the primary system. In addition, we propose an appearance probability matrix for secondary IoT devices (SIDs to maximize the supportable number of SIDs that can be installed in a car, in wearable devices, or for other monitoring devices, based on optimal deployment and probability. We derive fitness functions based on the above objectives and also consider signal to interference-plus-noise ratio (SINR and position constraints. The particle swarm optimization (PSO technique is used to find the best position and operating channel for the SIGSs. In a simulation study, the performance of the proposed method is evaluated and compared with a random resources allocation algorithm (parts of this paper were presented at the ICTC2017 conference (Wen et al., 2017.

Design of a secondary-vertex trigger system

International Nuclear Information System (INIS)

Husby, D.; Chew, P.; Sterner, K.; Selove, W.

1995-06-01

For the selection of beauty and charm events with high efficiency at the Tevatron, a secondary-vertex trigger system is under design. It would operate on forward-geometry events. The system would use on-line tracking of all tracks in the vertex detector, to identify events with clearly detached secondary vertices

The influence of selected teacher inputs on students’ academic achievement in the junior secondary school certificate mathematics in Namibia

Directory of Open Access Journals (Sweden)

Simon E. Akpo

2013-12-01

Full Text Available This study explored the link between teachers’ inputs and students’ academic achievement in the JSC Mathematics for the period 2006 to 2010. One hundred and fifty secondary schools selected from 573 secondary schools in the country constituted the target population. One hundred and sixty-four JSC mathematics teachers from the 150 secondary schools participated in the study, with the final JSC Mathematics results of the students serving as the dependent variable of the study. Mathematics teachers’ input data (academic qualifications, teaching experience and subject specialisation were collected from a questionnaire developed by the researchers. Standard multiple regression was used to analyse the link between teachers’ inputs and students’ academic achievement in JSC Mathematics at P < 0.05and P < 0.10 respectively. The study found that teachers’ academic qualifications and subject specialisation had a significant and positive relationship with students’ academic achievement in JSC Mathematics. Teachers’ gender, however, was not significantly related to students’ academic achievement in JSC Mathematics. This is the first time within the Namibian context that we have empirically demonstrated the link between teachers’ inputs and students’ academic achievement in JSC Mathematics. The study therefore provides support for the policy initiatives that seek to link teachers’ academic qualifications, subject specialisation and teaching experience to employment and classroom allocation.

Predicting Secondary Agriculture Teachers' Job Stress from Selected Personal, Family, and Work-Related Characteristics

Science.gov (United States)

Torres, Robert M.; Lambert, Misty D.; Lawver, Rebecca G.

2010-01-01

The study sought to describe the characteristics and explain the current level of job stress among secondary agriculture teachers. The sample consisted of 370 secondary agriculture teachers. Data were collected using the Job Stress Survey (Spielberger & Vagg, 1999). From the findings it was concluded that the average secondary agriculture teacher…

Wall thinning trend analyses for secondary side piping of Korean NPPs

International Nuclear Information System (INIS)

Hwang, K.M.; Jin, T.E.; Lee, S.H.; Jeon, S.C.

2003-01-01

Since the mid-1990s, nuclear power plants in Korea have experienced wall thinning, leaks, and ruptures of secondary side piping caused by flow-accelerated corrosion (FAC). The pipe failures have increased as operating time progresses. In order to prevent the FAC-induced pipe failures and to develop an effective FAC management strategy, KEPRI and KOPEC have conducted a study for developing systematic FAC management technology for secondary side piping of all Korean nuclear power plants. As a part of the study, FAC analyses were performed using the CHECWORKS code. The analysis results were used to select components for inspection and to determine inspection intervals on each nuclear power plant. This paper describes the introduction of the FAC analysis method and the wall thinning trend analysis results by reactor type, system, and water treatment amine. This paper also represents the site application feasibility for secondary side piping management. The site application feasibility of the analysis results was proven by comparisons of predicted and measured wear rates. (author)

Ecotoxicological effects of selected cyanobacterial secondary metabolites a short review

International Nuclear Information System (INIS)

Wiegand, C.; Pflugmacher, S.

2005-01-01

Cyanobacteria are one of the most diverse groups of gram-negative photosynthetic prokaryotes. Many of them are able to produce a wide range of toxic secondary metabolites. These cyanobacterial toxins can be classified in five different groups: hepatotoxins, neurotoxins, cytotoxins, dermatotoxins, and irritant toxins (lipopolysaccharides). Cyanobacterial blooms are hazardous due to this production of secondary metabolites and endotoxins, which could be toxic to animals and plants. Many of the freshwater cyanobacterial blooms include species of the toxigenic genera Microcystis, Anabaena, or Plankthotrix. These compounds differ in mechanisms of uptake, affected organs, and molecular mode of action. In this review, the main focus is the aquatic environment and the effects of these toxins to the organisms living there. Some basic toxic mechanisms will be discussed in comparison to the mammalian system

A General Catalyst for Site-Selective C(sp(3))-H Bond Amination of Activated Secondary over Tertiary Alkyl C(sp(3))-H Bonds.

Science.gov (United States)

Scamp, Ryan J; Jirak, James G; Dolan, Nicholas S; Guzei, Ilia A; Schomaker, Jennifer M

2016-06-17

The discovery of transition metal complexes capable of promoting general, catalyst-controlled and selective carbon-hydrogen (C-H) bond amination of activated secondary C-H bonds over tertiary alkyl C(sp(3))-H bonds is challenging, as substrate control often dominates when reactive nitrene intermediates are involved. In this letter, we report the design of a new silver complex, [(Py5Me2)AgOTf]2, that displays general and good-to-excellent selectivity for nitrene insertion into propargylic, benzylic, and allylic C-H bonds over tertiary alkyl C(sp(3))-H bonds.

Secondary gamma-ray data for shielding calculation

International Nuclear Information System (INIS)

Miyasaka, Sunichi

1979-01-01

In deep penetration transport calculations, the integral design parameters is determined mainly by secondary particles which are produced by interactions of the primary radiation with materials. The shield thickness and the biological dose rate at a given point of a bulk shield are determined from the contribution from secondary gamma rays. The heat generation and the radiation damage in the structural and shield materials depend strongly on the secondary gamma rays. In this paper, the status of the secondary gamma ray data and its further problems are described from the viewpoint of shield design. The secondary gamma-ray data in ENDF/B-IV and POPOP4 are also discussed based on the test calculations made for several shield assemblies. (author)

Attitude of secondary school students towards guidance and ...

African Journals Online (AJOL)

The Study investigated the attitude of secondary students towards guidance and counselling services. Descriptive research design of the survey type was used. Three hypotheses were formulated to guide the study. A total of 400 secondary school students were selected from ten (10) schools through stratified random ...

CBT for childhood anxiety disorders: differential changes in selective attention between treatment responders and non-responders.

Science.gov (United States)

Legerstee, Jeroen S; Tulen, Joke H M; Dierckx, Bram; Treffers, Philip D A; Verhulst, Frank C; Utens, Elisabeth M W J

2010-02-01

This study examined whether treatment response to stepped-care cognitive-behavioural treatment (CBT) is associated with changes in threat-related selective attention and its specific components in a large clinical sample of anxiety-disordered children. Ninety-one children with an anxiety disorder were included in the present study. Children received a standardized stepped-care CBT. Three treatment response groups were distinguished: initial responders (anxiety disorder free after phase one: child-focused CBT), secondary responders (anxiety disorder free after phase two: child-parent-focused CBT), and treatment non-responders. Treatment response was determined using a semi-structured clinical interview. Children performed a pictorial dot-probe task before and after stepped-care CBT (i.e., before phase one and after phase two CBT). Changes in selective attention to severely threatening pictures, but not to mildly threatening pictures, were significantly associated with treatment success. At pre-treatment assessment, initial responders selectively attended away from severely threatening pictures, whereas secondary responders selectively attended toward severely threatening pictures. After stepped-care CBT, initial and secondary responders did not show any selectivity in the attentional processing of severely threatening pictures. Treatment non-responders did not show any changes in selective attention due to CBT. Initial and secondary treatment responders showed a reduction of their predisposition to selectively attend away or toward severely threatening pictures, respectively. Treatment non-responders did not show any changes in selective attention. The pictorial dot-probe task can be considered a potentially valuable tool in assigning children to appropriate treatment formats as well as for monitoring changes in selective attention during the course of CBT.

Selectivity coefficients of ion-selective magnesium electrodes used for simultaneous determination of magnesium and calcium ions.

Science.gov (United States)

Maj-Zurawska, Magdalena; Lewenstam, Andrzej

2011-12-15

Membrane ion-selective magnesium electrodes are commonly used to determine ionized magnesium concentration in blood serum and intracellular fluid by potentiometric clinical analyzers. The selectivity of these electrodes against calcium ion is typically insufficient to avoid calcium interference in blood serum analysis. For this reason the selectivity coefficient for calcium ion has to be studied to make possible any mathematical corrections for calcium ion influence. Existing methods relate to the thermodynamic concept of ISE response which suggest a single constant value of the selectivity coefficient and slope that are stable over the concentration ranges of calcium and magnesium ions in the samples. Unfortunately, this rarely happens, and we rather observe dependences on solution and membrane composition, readout time, matrices (anticoagulant, vial coats) that justify usage of apparent selectivities and slopes. To get the practical insight into the response of magnesium ion-selective electrodes a novel method for estimating the selectivity coefficients and the slope of the electrode characteristics is proposed. This method is an effective starting point for selecting electrodes and designing transient signal software in a potentiometric clinical analyzer. The method allows obtaining the ionized magnesium concentration in blood serum with minimal possible error by addressing the assessed targets, i.e. apparent selectivity and slope. The method is based on computer simulation and on the Nicolsky-Eisenman equation. Usually only a few iterations are needed to obtain stable congruent results. The method presented is particularly useful in conditions where is not possible to obtain calibration curve, which is typical for clinical analyzer where at most three point calibration is performed. Copyright © 2011 Elsevier B.V. All rights reserved.

Voltammetric determination of copper in selected pharmaceutical preparations--validation of the method.

Science.gov (United States)

Lutka, Anna; Maruszewska, Małgorzata

2011-01-01

It were established and validated the conditions of voltammetric determination of copper in pharmaceutical preparations. The three selected preparations: Zincuprim (A), Wapń, cynk, miedź z wit. C (B), Vigor complete (V) contained different salts and different quantity of copper (II) and increasing number of accompanied ingredients. For the purpose to transfer copper into solution, the samples of powdered tablets of the first and second preparation were undergone extraction and of the third the mineralization procedures. The concentration of copper in solution was determined by differential pulse voltammetry (DP) using comparison with standard technique. In the validation process, the selectivity, accuracy, precision and linearity of DP determination of copper in three preparations were estimated. Copper was determined within the concentration range of 1-9 ppm (1-9 microg/mL): the mean recoveries approached 102% (A), 100% (B), 102% (V); the relative standard deviations of determinations (RSD) were 0.79-1.59% (A), 0.62-0.85% (B) and 1.68-2.28% (V), respectively. The mean recoveries and the RSDs of determination satisfied the requirements for the analyte concentration at the level 1-10 ppm. The statistical verification confirmed that the tested voltammetric method is suitable for determination of copper in pharmaceutical preparation.

Changes in Children's Autonomous Motivation toward Physical Education during Transition from Elementary to Secondary School: A Self-Determination Perspective

Science.gov (United States)

Rutten, Cindy; Boen, Filip; Vissers, Nathalie; Seghers, Jan

2015-01-01

Based on Self-Determination Theory (Deci & Ryan, 2000), this study tested whether changes in autonomous motivation toward physical education (AMPE) during the transition from elementary to secondary school can be predicted by changes in perceived need support from the physical education (PE) teacher and perceived physical school environment.…

Studies on the determination of surface deuterium in AISI 1062, 4037, and 4140 steels by secondary ion mass spectrometry

Science.gov (United States)

Sastri, V. S.; Donepudi, V. S.; McIntyre, N. S.; Johnston, D.; Revie, R. W.

1988-12-01

The concentration of deuterium at the surface of cathodically charged high strength steels AISI 1062, 4037, and 4140 has been determined by secondary ion mass spectrometry (SIMS). The beneficial effects of pickling in NAP (a mixture of nitric, acetic, and phosphoric acids) to remove surfacebound deuterium have been observed.

Using Confidence Interval-Based Estimation of Relevance to Select Social-Cognitive Determinants for Behavior Change Interventions

Directory of Open Access Journals (Sweden)

Rik Crutzen

2017-07-01

Full Text Available When developing an intervention aimed at behavior change, one of the crucial steps in the development process is to select the most relevant social-cognitive determinants. These determinants can be seen as the buttons one needs to push to establish behavior change. Insight into these determinants is needed to select behavior change methods (i.e., general behavior change techniques that are applied in an intervention in the development process. Therefore, a study on determinants is often conducted as formative research in the intervention development process. Ideally, all relevant determinants identified in such a study are addressed by an intervention. However, when developing a behavior change intervention, there are limits in terms of, for example, resources available for intervention development and the amount of content that participants of an intervention can be exposed to. Hence, it is important to select those determinants that are most relevant to the target behavior as these determinants should be addressed in an intervention. The aim of the current paper is to introduce a novel approach to select the most relevant social-cognitive determinants and use them in intervention development. This approach is based on visualization of confidence intervals for the means and correlation coefficients for all determinants simultaneously. This visualization facilitates comparison, which is necessary when making selections. By means of a case study on the determinants of using a high dose of 3,4-methylenedioxymethamphetamine (commonly known as ecstasy, we illustrate this approach. We provide a freely available tool to facilitate the analyses needed in this approach.

Using Confidence Interval-Based Estimation of Relevance to Select Social-Cognitive Determinants for Behavior Change Interventions.

Science.gov (United States)

Crutzen, Rik; Peters, Gjalt-Jorn Ygram; Noijen, Judith

2017-01-01

When developing an intervention aimed at behavior change, one of the crucial steps in the development process is to select the most relevant social-cognitive determinants. These determinants can be seen as the buttons one needs to push to establish behavior change. Insight into these determinants is needed to select behavior change methods (i.e., general behavior change techniques that are applied in an intervention) in the development process. Therefore, a study on determinants is often conducted as formative research in the intervention development process. Ideally, all relevant determinants identified in such a study are addressed by an intervention. However, when developing a behavior change intervention, there are limits in terms of, for example, resources available for intervention development and the amount of content that participants of an intervention can be exposed to. Hence, it is important to select those determinants that are most relevant to the target behavior as these determinants should be addressed in an intervention. The aim of the current paper is to introduce a novel approach to select the most relevant social-cognitive determinants and use them in intervention development. This approach is based on visualization of confidence intervals for the means and correlation coefficients for all determinants simultaneously. This visualization facilitates comparison, which is necessary when making selections. By means of a case study on the determinants of using a high dose of 3,4-methylenedioxymethamphetamine (commonly known as ecstasy), we illustrate this approach. We provide a freely available tool to facilitate the analyses needed in this approach.

Determination of plutonium by secondary coulometric titration with internally generated iron(II) Pt. 2

International Nuclear Information System (INIS)

Chitnis, R.T.; Talnikar, S.G.; Thakur, V.A.; Paranjape, A.H.

1979-01-01

Determination of plutonium by secondary coulometry involving the controlled potential technique for the generation of an iron(II) mediator, is reported in Part I. In this paper, the same determination is reported using constant current coulometry for the generation of the mediator, and zero current potentiometry for end-point detection. The factors affecting the current efficiency, viz. current density and supporting electrolyte composition have been checked in order to define the appropriate conditions for obtaining 100% current efficiency. The original method of Carson et al. suffers from the disadvantage that it involves complicated sample treatment. Introduction of perchloric acid treatment as a method for the oxidation of plutonium and the pretitration of the supporting electrolyte to the end-point potential prior to sample addition, have considerably helped to improve the precision and accuracy of the method. Exhaustive analytical data are reported covering plutonium quantities ranging from 25 micrograms to 5 milligrams, which establishes the scope of the method. (author)

Effect of energy selection on quantitative analysis in secondary ion microanalysis

International Nuclear Information System (INIS)

Steele, I.M.; Solberg, T.N.; Smith, J.V.; Clayton, R.N.; Hutcheon, I.D.

1977-01-01

Systematic change of voltage on the components of the secondary ion (SI) extraction system of our AEI-IM20 ion microprobe produced major changes of relative intensities of secondary ions passing through the mass spectrometer. The repeller, which bends the SI beam through about 60 0 , has the greatest effect, and can be used to plot the energy distribution. The extractor and the deflecting and focusing components have smaller but significant effects. Because low-energy secondary ions have a near-symmetrical distribution, whereas high-energy ones have an assymetric distribution favoring high energies, tuning of the acceptance band to higher energy reduces interference from low-energy ions, which tend to be unwanted molecular ions, at the expense of reduced transmission. Tuning to lower energy increases interference but gives higher transmission. The former condition is desirable for instruments restricted to low mass resolution, whereas both conditions are valuable for instruments adjustable for both high and low mass resolution. Other important factors are (a) sensitivity to surface irregularities which perturb SI energy collection, and (b) change in derived 'temperatures' from thermodynamic sputtering models merely from tuning the energy acceptance band. Careful attention to the above factors yielded reproducible SI ratios for the binary series of plagioclase feldspars. (Auth.)

Highly selective determination of methylmercury with methylmercury-imprinted polymers

Energy Technology Data Exchange (ETDEWEB)

Liu Yongwen [Department of Chemistry, Shanxi Datong University, Datong 037009 (China)]. E-mail: dtlyw@263.net; Zai Yunhui [School of Chemistry and Chemical Engineering of Lanzhou University, Lanzhou 730000 (China); Chang Xijun [School of Chemistry and Chemical Engineering of Lanzhou University, Lanzhou 730000 (China); Guo Yong [Department of Chemistry, Shanxi Datong University, Datong 037009 (China); Meng Shuangming [Department of Chemistry, Shanxi Datong University, Datong 037009 (China); Feng Feng [Department of Chemistry, Shanxi Datong University, Datong 037009 (China)

2006-08-11

Methylmercury-imprinted and non-imprinted polymers were prepared by formation monomer complex of methylmercury with (4-ethenylphenyl)-4-formate-6-phenyl-2,2'-bipyridine and thermally polymerizing with divinylbenzene (crosslinker) in the presence of 2,2'-azobisisobutyronitrile as initiator and subsequently leached with the acidic thiourea solution (1.0 mol L{sup -1} of thiourea and 4.0 mol L{sup -1} of HCl). In the same way, non-imprinted copolymers were prepared without methylmercury chloride added. The separation and preconcentration characteristics of the polymers for methylmercury were investigated by batch and column procedures. The results demonstrated that the methylmercury-imprinted polymers had higher adsorption capacity (170 {mu}mol g{sup -1} of dry microbeads) and good selectivity for methylmercury compared to non-imprinted polymers. The distribution ratio (D) values of the methylmercury-imprinted polymers increased for methylmercury with respect to both D values of Hg(II), Cu(II), Zn(II), Cd(II) and non-imprinted polymers. The relatively selective factor ({alpha} {sub r}) values of CH{sub 3}Hg{sup +}/Hg(II), CH{sub 3}Hg{sup +}/Cu(II), CH{sub 3}Hg{sup +}/Zn(II), and CH{sub 3}Hg{sup +}/Cd(II) are 24.0, 46.7, 50.7, and 40.2, which are greater than 1. The methylmercury-imprinted polymers can be used at least twenty times with recoveries no less than 95%. Based on the packed columns with methylmercury-imprinted polymers, a highly selective solid-phase extraction (SPE) and preconcentration method for methylmercury was developed. The metal ion imprinted polymer solid-phase extraction (MIIP-SPE) preconcentration procedure showed a linear calibration curve within concentration range from 0.093 to 22 {mu}g L{sup -1}. The detection limit and quantification limit were 0.041 and 0.093 {mu}g L{sup -1} (3{sigma}) for cold vapor atomic absorption spectrometry (CVAAS). The relative standard deviation of the 10 replicate determinations was 3.5% for the

Primary and Secondary Selection Tools in an Optometry Admission Process.

Science.gov (United States)

Spafford, Marlee M.

2000-01-01

A five-year evaluation of the admissions decision process at the University of Waterloo (Ontario) School of Optometry found that when primary tools (i.e., university grades, Optometry Admission Test scores) did not differentiate candidates, there was an increased emphasis on secondary tools (i.e., interview, autobiographic sketch, prerequisite…

Assessment of children environmental exposure to secondary emission of nickel, lead and copper

Directory of Open Access Journals (Sweden)

Jerzy Kwapuliński

2012-12-01

Full Text Available Introduction: Total rating impact of particulate matter in ground air layer recently takes on particular significance in evaluation of health risk. Indeed particulate matter is of interest to many research centres, however in so far PM related works the probability of adverse health impacts were not taken into account triggered with impact of additional presence of particulate matter from secondary dusting. The aim of the work: The work target was determination of secondary emission of Cu, Ni and Pb measured in streets with high traffic volume in many towns of Silesia Voivodeship. Materials and methods: Dust collected from the distance of about 200 m from busy roads in Upper Silesia cities was analyzed by the method of plasma spectrophotometry. The phenomenon of secondary dusting was defined by few coefficients of: secondary emission, enrichment, contamination and parameter of extra mass of a given metal in widespread air pollution. Results: It was concluded that absorbed dose of Cu and Pb changes depends on the area under study and decreases along with child’s age. Decrease of absorbed age depending doses is explained, so far, by significant increase of body mass in comparison to anatomically conditioned size of respiratory system.Also health risk estimated in relation to children residing in selected areas is diversified.. And it also decreases along with the children growing older. It appears, however, that health risk is determined by the volume of secondary PM emission and to children mostly threatened with Ni belong those who are particularly exposed to secondary emission of this metal. The secondary dusting is particularly dangerous for respiratory system and plays more important role than averaged content of this chemical in the environment.

Factors Influencing Examination Malpractice in Secondary Schools ...

African Journals Online (AJOL)

The main purpose of this study was to investigate factors influencing examination malpractice in some selected secondary schools in Cross River State, Nigeria. A sample of one thousand two hundred (1200) students were selected across the three educational zones of Ogoja, Ikom and Calabar using stratified, random ...

Potentiometric determination of sulfate with EDTA and the cupric-selective electrode

International Nuclear Information System (INIS)

Baumann, E.W.

1976-11-01

Sulfate was indirectly determined by precipitating sulfate as BaSO 4 and then dissolving BaSO 4 in excess ammoniacal EDTA. The excess EDTA was titrated potentiometrically with La 3+ . A cupric-selective electrode was used to detect the end point. About 10 -3 M SO 4 2- was determined in 3M HCl solutions of metal oxides with a relative standard deviation of 3.5 percent and a bias of +4 percent

Determinants of Individual Academic Achievement - Group Selectivity Effects Have Many Dimensions

NARCIS (Netherlands)

Zwick, Th.

2013-01-01

This paper measures determinants of individual academic achievements. In addition to an extensive list of individual characteristics, skills obtained during study and socio-economic background factors, many dimensions of selectivity into academic study subjects are shown to drive individual academic

Clinical significance of determination serum sex hormones levels in patients with secondary amenorrhea

International Nuclear Information System (INIS)

Jiang Hua

2007-01-01

Objective: To explore the clinical significance of changes of serum sex hormones levels in patients with secondary amenorrhea. Methods: Serum levels of E 2 , FSH, LH, PRL and P were detected with RIA in 33 patients with secondary amenorrhea and 30 controls. Results: In the patients, the serum E 2 levels were significantly lower and FSH, LH, PRL and P levels were significantly higher than those in controls (P 2 , FSH, LH, PRL and P levels is of help for assessment of severity of secondary amenorrhea as well as outcome prediction. (authors)

Variances in family carers' quality of life based on selected relationship and caregiving indicators: A quantitative secondary analysis.

Science.gov (United States)

Naef, Rahel; Hediger, Hannele; Imhof, Lorenz; Mahrer-Imhof, Romy

2017-06-01

To determine subgroups of family carers based on family relational and caregiving variables and to explore group differences in relation to selected carer outcomes. Family caregiving in later life holds a myriad of positive and negative outcomes for family members' well-being. However, factors that constitute family carers' experience and explain variances are less well understood. A secondary data analysis using cross-sectional data from a controlled randomised trial with community-dwelling people 80 years or older and their families. A total of 277 paired data sets of older persons and their family carers were included into the analysis. Data were collected via mailed questionnaires and a geriatric nursing assessment. A two-step cluster analysis was performed to determine subgroups. To discern group differences, appropriate tests for differences with Bonferroni correction were used. Two family carer groups were identified. The low-intensity caregiver group (57% of carers) reported high relationship quality and self-perceived ease of caregiving. In contrast, the high-intensity caregiver group (43% of carers) experienced significantly lower relationship quality, felt less prepared and appraised caregiving as more difficult, time intensive and burdensome. The latter cared for older, frailer and more dependent octogenarians and had significantly lower levels of quality of life and self-perceived health compared to the low-intensity caregiver group. A combination of family relational and caregiving variables differentiates those at risk for adverse outcomes. Family carers of frailer older people tend to experience higher strain, lower relationship quality and ability to work together as a family. Nurses should explicitly assess family carer needs, in particular when older persons are frail. Family carer support interventions should address caregiving preparedness, demand and burden, as well as concerns situated in the relationship. © 2016 John Wiley & Sons Ltd.

Pupil Home Background Characteristics and Academic Performance in Senior Secondary Schools: A Case Study of Selected Secondary Schools in Kitwe District, Zambia

Science.gov (United States)

Kakumbi, Zonic; Samuel, Elizabeth B.; Mulendema, Peter J.

2016-01-01

The purpose of this research was to investigate pupil background characteristics and academic performance in senior secondary schools in Kitwe district with a view of recommending on how to improve pupils' performance. The study was conducted in Kitwe district because in the past years pupils' performance in senior secondary schools has been…

Chemistry of the aqueous medium - Determining factor of corrosion in carbon steel components of secondary circuit

International Nuclear Information System (INIS)

Radulescu, M.; Pirvan, I.; Dinu, A.; Velciu, L.

2003-01-01

The interplay of chemistry of aqueous medium and corrosion processes followed by deposition and/or release of corrosion products determines both formation and growth of superficial films as well as the kinetics of ion release from materials into the aqueous medium. Material corrosion in the secondary circuit of a NPP can be minimized by choosing the materials of the components and by a rigorous inspection of the chemistry of aqueous agent. The chemical inspection helps in minimizing: - the corrosion of the components immersed in feedwater and vapor and of Steam Generator components; - 'dirtying' of the systems particularly of the surfaces implied in heat transfer; - the amount of insoluble chemical species resulting in corrosion process and carried along the circuit; - the corrosion of secondary circuit components during revisions or outages. An important role among the chemical parameters of the fluids circulated in NPP tubing appears to be the pH. In CANDU reactors it must be kept within the range of 8.7 to 9.4 by treating the medium with volatile amines (morpholine and cyclohexylamine). A plot is presented giving the corrosion rate of carbon steels as a function of the pH of the medium. Besides, the oxygen concentration dissolved in the aqueous medium must be maintained under 5 μg per water kg. Other factors determining the corrosion rates are also discussed. The paper gives the results of the experiments done with various materials, solutions and analysis methods

Mechanism of secondary recrystallization of Goss grains in grain-oriented electrical steel

Science.gov (United States)

Hayakawa, Yasuyuki

2017-12-01

Since its invention by Goss in 1934, grain-oriented (GO) electrical steel has been widely used as a core material in transformers. GO exhibits a grain size of over several millimeters attained by secondary recrystallization during high-temperature final batch annealing. In addition to the unusually large grain size, the crystal direction in the rolling direction is aligned with , which is the easy magnetization axis of α-iron. Secondary recrystallization is the phenomenon in which a certain very small number of {110} (Goss) grains grow selectively (about one in 106 primary grains) at the expense of many other primary recrystallized grains. The question of why the Goss orientation is exclusively selected during secondary recrystallization has long been a main research subject in this field. The general criterion for secondary recrystallization is a small and uniform primary grain size, which is achieved through the inhibition of normal grain growth by fine precipitates called inhibitors. This paper describes several conceivable mechanisms of secondary recrystallization of Goss grains mainly based on the selective growth model.

Assessment of Noise and Associated Health Impacts at Selected Secondary Schools in Ibadan, Nigeria

International Nuclear Information System (INIS)

Ana, G.R.E.E.; Brown, G.E.; Sridhar, M.K.C.; Shendell, D.G.; Shendell, D.G.; Shendell, D.G.

2010-01-01

Background. Most schools in Ibadan, Nigeria, are located near major roads (mobile line sources). We conducted an initial assessment of noise levels and adverse noise-related health and learning effects. Methods. For this descriptive, cross-sectional study, four schools were selected randomly from eight participating in overall project. We administered 200 questionnaires, 50 per school, assessing health and learning-related outcomes. Noise levels (A-weighted decibels, dBA) were measured with calibrated sound level meters. Traffic density was assessed for school with the highest measured dBA. Observational checklists assessed noise control parameters and building physical attributes. Results. Short-term, cross-sectional school-day noise levels ranged 68.3-84.7 dBA. Over 60% of respondents reported that vehicular traffic was major source of noise, and over 70% complained being disturbed by noise. Three schools reported tiredness, and one school lack of concentration, as the most prevalent noise-related health problems. Conclusion. Secondary school occupants in Ibadan, Nigeria were potentially affected by exposure to noise from mobile line sources.

Importance of secondary damage in downer cows.

Science.gov (United States)

Poulton, P J; Vizard, A L; Anderson, G A; Pyman, M F

2016-05-01

To investigate the relative importance in downer cows of the primary cause of recumbency in comparison with secondary complications. Downer dairy cows were monitored during their recumbency under field conditions in South Gippsland, Victoria, Australia. The cause of the original recumbency of the 218 cows was determined and secondary damage, status on day 7 and final outcome were recorded. Some type of secondary damage was found in 183/218 (84%) cows, of which 173/218 (79%) had damage deemed to be clinically important. By day 7, 52 (24%) had recovered and 69 (32%) eventually recovered. Of the 149 (68%) cows that were euthanased or died, 23 (15%) were deemed to have been lost solely from the primary cause, 107 (72%) from secondary damage and 19 (13%) from a combination of both. There was no difference in recovery among the five broad groups of causes of primary recumbency. Secondary damage was very common and presented in a large variety of ways, with many cows having multiple types of secondary damage concurrently. For most cows the secondary damage was more important than the initial primary damage in determining their fate. © 2016 Australian Veterinary Association.

UV light selectively coinduces supply pathways from primary metabolism and flavonoid secondary product formation in parsley

Science.gov (United States)

Logemann, Elke; Tavernaro, Annette; Schulz, Wolfgang; Somssich, Imre E.; Hahlbrock, Klaus

2000-01-01

The UV light-induced synthesis of UV-protective flavonoids diverts substantial amounts of substrates from primary metabolism into secondary product formation and thus causes major perturbations of the cellular homeostasis. Results from this study show that the mRNAs encoding representative enzymes from various supply pathways are coinduced in UV-irradiated parsley cells (Petroselinum crispum) with two mRNAs of flavonoid glycoside biosynthesis, encoding phenylalanine ammonia-lyase and chalcone synthase. Strong induction was observed for mRNAs encoding glucose 6-phosphate dehydrogenase (carbohydrate metabolism, providing substrates for the shikimate pathway), 3-deoxyarabinoheptulosonate 7-phosphate synthase (shikimate pathway, yielding phenylalanine), and acyl-CoA oxidase (fatty acid degradation, yielding acetyl-CoA), and moderate induction for an mRNA encoding S-adenosyl-homocysteine hydrolase (activated methyl cycle, yielding S-adenosyl-methionine for B-ring methylation). Ten arbitrarily selected mRNAs representing various unrelated metabolic activities remained unaffected. Comparative analysis of acyl-CoA oxidase and chalcone synthase with respect to mRNA expression modes and gene promoter structure and function revealed close similarities. These results indicate a fine-tuned regulatory network integrating those functionally related pathways of primary and secondary metabolism that are specifically required for protective adaptation to UV irradiation. Although the response of parsley cells to UV light is considerably broader than previously assumed, it contrasts greatly with the extensive metabolic reprogramming observed previously in elicitor-treated or fungus-infected cells. PMID:10677554

Determination of soil weathering rates with U-Th series disequilibria: approach on bulk soil and selected mineral phases

International Nuclear Information System (INIS)

Gontier, Adrien

2014-01-01

The aim of the present study was to evaluate weathering and soil formation rates using U-Th disequilibria in bulk soil or separated minerals. The specific objectives of this work were to evaluate the use of U-Th chronometric tools 1) regarding the impact of a land cover change and the bedrock characteristics 2) in selected secondary mineral phases and 3) in primary minerals. On the Breuil-Chenue (Morvan) site, no vegetation effect neither a grain size effect was observed on the U-Th series in the deepest soil layers (≤ 40 cm). The low soil production rate (1-2 mm/ka) is therefore more affected by regional geomorphology than by the underlying bedrock texture. In the second part of this work, based on a thorough evaluation of different techniques, a procedure was retained to extract Fe-oxides without chemical fractionation. Finally, the analysis of biotites hand-picked from one of the studied soil profile showed that U-series disequilibria allow to independently determinate the field-weathering-rate of minerals. (author)

Process for determining the remediation category of hazardous substance sites

International Nuclear Information System (INIS)

Sieben, A.K.

1994-01-01

An evaluation process has been developed that aids in selecting the appropriate remediation category of hazardous substance sites. Three general remediation categories have been established: No further Action: Potential Early Action: and Defer for RI/FS or Transition/Decontamination and Decommissioning. This evaluation method is a preliminary screening process only and will not identify the most appropriate remediation alternative for each site. The remedy selection process can proceed only after a remediation category is determined for each site. All sites are evaluated at a preliminary screening level to determine the general remediation category. After the first screen, a secondary evaluation is performed on both the PEA sites and the DEFER sites. For PEAs, this secondary evaluation will incorporate additional specific factors, such as a screening level risk assessment. For the DEFER sites feasibility factors will be used to distinguish between the sites which should undergo a normal RI/FS and the sites which will be recommended to be remediated in association with D ampersand D of buildings. Ultimately, all of the sites will be placed into one of four remediation categories

Determination of Selected Amino Acids in Serum of Patients with Liver Disease.

Science.gov (United States)

Kanďár, Roman; Drábková, Petra; Toiflová, Tereza; Čegan, Alexander

2016-01-01

The determination of amino acids can be a reliable approach for extended diagnosis of liver diseases. This is because liver disease can be a cause of impaired amino acid metabolism. Therefore, a method for the determination of serum amino acids, applicable for clinical purposes, is necessary. The aim of this study was to find differences in the levels of selected amino acids between patients with liver disease and a control group. Samples of peripheral venous blood were obtained from a group of patients with liver disease (n = 131, 59 women at an average age of 60 years and 72 men at an average age of 52 years) and a control group (n = 105, 47 women at an average age of 62 years and 58 men at an average age of 58 years). Before the separation, the amino acids were derivatized with naphthalene-2,3-dicarboxaldehyde. For the separation, reverse phase column was used. The effluent was monitored with a fluorescence detector. There were significant differences in the concentrations of some amino acids between the patients and the control group, but also between women and men. Correlations between some amino acids and markers of liver blood tests and lipid metabolism were observed. A simple, relatively rapid and selective HPLC method with fluorescence detection for the determination of selected amino acids in serum has been developed.

Determination of extractable fluoride in contaminated soils with ion-selective electrode

OpenAIRE

Mirlean, Nicolai; Baraj, Besnik; Garcia, Marina Reback Domingues; Niencheski, Luis Felipe Hax; Baisch, Paulo Roberto Martins; Casartelli, Maria Regina de Oliveira; Robinson, Daniel

2003-01-01

In a factorial design study involving the determination of F- by ion-selective electrodes, a significant interference was demonstrated for Fe, with an even more pronounced interference for Al. The fluoride leaching procedure from polluted soil showed more reliable results using 0.5 M citric acid

Do male secondary sexual characters signal ejaculate quality? A meta-analysis.

Science.gov (United States)

Mautz, Brian S; Møller, Anders P; Jennions, Michael D

2013-08-01

There are two reasons why researchers are interested in the phenotypic relationship between the expression of male secondary sexual characters (SSCs) and 'ejaculate quality' (defined as sperm/ejaculate traits that are widely assumed to increase female fertility and/or sperm competitiveness). First, if the relationship is positive then females could gain a direct benefit by choosing more attractive males for fertility assurance reasons ('the phenotype-linked fertility' hypothesis). Second, there is much interest in the direction of the correlation between traits favoured by pre-copulatory sexual selection (i.e. affecting mating success) and those favoured by post-copulatory sexual selection (i.e. increasing sperm competitiveness). If the relationship is negative this could lead to the two forms of selection counteracting each other. Theory predicts that the direction of the relationship could be either positive or negative depending on the underlying genetic variance and covariance in each trait, the extent of variation among males in condition (resources available to allocate to reproductive traits), and variation among males in the cost or rate of mating. We conducted a meta-analysis to determine the average relationship between the expression of behavioural and morphological male secondary sexual characters and four assays of ejaculate quality (sperm number, viability, swimming speed and size). Regardless of how the data were partitioned the mean relationship was consistently positive, but always statistically non-significant. The only exception was that secondary sexual character expression was weakly but significantly positively correlated with sperm viability (r = 0.07, P < 0.05). There was no significant difference in the strength or direction of the relationship between behavioural and morphological SSCs, nor among relationships using the four ejaculate quality assays. The implications of our findings are discussed. © 2013 The Authors. Biological Reviews �

Debriefing Note Secondary Education Support Programme

DEFF Research Database (Denmark)

Webster, Neil; Vagnby, Bo Hellisen; Thomsen, Thomas J.

Debriefing note regarding joint programming for the Secondary Education Support Programme (2003- 2007). The note specifies preparation of SIP Physical Guidelines; Training needs assessment for Physical School Status and Rapid Technical Assessments; SIP/DEP preparation; Selection criteria...

Killer whale prey - Determining prey selection by southern resident killer whales (SRKW)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Prey selectivity by southern resident killer whales is being determined by analyses of fish scales and tissue from predation events and feces. Information on killer...

Surgical treatment of secondary peritonitis : A continuing problem.

Science.gov (United States)

van Ruler, O; Boermeester, M A

2017-01-01

Secondary peritonitis remains associated with high mortality and morbidity rates. Treatment of secondary peritonitis is challenging even in modern medicine. Surgical intervention for source control remains the cornerstone of treatment, beside adequate antimicrobial therapy and resuscitation. A randomized clinical trial showed that relaparotomy on demand (ROD) after initial emergency surgery is the preferred treatment strategy, irrespective of the severity and extent of peritonitis. The effective and safe use of ROD requires intensive monitoring of the patient in a setting where diagnostic tests and decision making about relaparotomy are guaranteed round the clock. The lack of knowledge on timely and adequate patient selection, together with the lack of use of easy but reliable monitoring tools, seems to hamper full implementation of ROD. The accuracy of the relap decision tool is reasonable for prediction of ongoing peritonitis and selection for computer tomography (CT). The value of CT in an early postoperative phase is unclear. Future research and innovative technologies should focus on the additive value of CT in cases of operated secondary peritonitis and on the further optimization of bedside prediction tools to enhance adequate patient selection for intervention in a multidisciplinary setting.

Sex ratio selection and multi-factorial sex determination in the housefly : A dynamic model

NARCIS (Netherlands)

Kozielska, M.A.; Pen, I.R.; Beukeboom, L.W.; Weissing, F.J.

Sex determining (SD) mechanisms are highly variable between different taxonomic groups and appear to change relatively quickly during evolution. Sex ratio selection could be a dominant force causing such changes. We investigate theoretically the effect of sex ratio selection on the dynamics of a

A comparison of private and public secondary school biology ...

African Journals Online (AJOL)

This paper compares external motivation and job satisfaction in private and public secondary schools biology teachers in Education District IV of Lagos state. The sample for the study consists of 120 Biology teachers selected from ten private and ten public secondary schools. A 20-items Likert type questionnaire was ...

Post-Secondary Students' Views on Health: Support for Individual and Social Health Determinants

Science.gov (United States)

Shyleyko, Robert; Godley, Jenny

2012-01-01

This paper examines how post-secondary students understand health, and whether opinions about health are correlated with area of study. We present results from an online survey administered in 2011 to 287 students at one post-secondary institution in Western Canada. Overall, the survey students are more likely to adopt an individualistic, rather…

Status of Higher Secondary School Libraries in Thiruvallur District

Science.gov (United States)

Seenivasan, M.; Kumar, N. Ashok

2014-01-01

Libraries are the main sources of knowledge. They play a major role in fostering reading habit among school children. Hence, it is deemed interactive to study the status of higher secondary school libraries in Thiruvallur District, Tamil Nadu. For the Analysis 50 Higher Secondary Schools were selected randomly comprising of Government Higher…

Secondary Voltage Control for Harmonics Suppression in Islanded Microgrids

DEFF Research Database (Denmark)

Wang, Xiongfei; Guerrero, Josep M.; Blaabjerg, Frede

2011-01-01

in islanded microgrids. In addition to the centralized controller for fundamental frequency voltage component, a selective harmonic compensator is implemented in the secondary voltage control system. With the help of Park transformation, the cyclic references generated by the selective harmonic compensator...

Method for routine determination of fluoride in urine by selective ion- electrode

International Nuclear Information System (INIS)

Pires, M.A.F.; Bellintani, S.A.

1985-01-01

A simple, fast and sensitive method is outlined for determining fluoride in urine of workers who handle fluoride compounds. The determination is based on the measurement of fluoride by ion selective electrode. Cationic interferents like Ca ++ , Mg ++ , Fe +++ and Al +++ are complexed by EDTA and citric acid. Common anions present in urine, such as Cl - , PO --- 4 and SO -- 4 do not interfere in the method. (Author) [pt

Patients’ perspectives on the medical primary–secondary care interface: systematic review and synthesis of qualitative research

Science.gov (United States)

Sampson, Rod; Cooper, Jamie; Barbour, Rosaline; Polson, Rob; Wilson, Philip

2015-01-01

Objectives To synthesise the published literature on the patient experience of the medical primary–secondary care interface and to determine priorities for future work in this field aimed at improving clinical outcomes. Design Systematic review and metaethnographic synthesis of primary studies that used qualitative methods to explore patients’ perspectives of the medical primary–secondary care interface. Setting International primary–secondary care interface. Data sources EMBASE, MEDLINE, CINAHL Plus with Full text, PsycINFO, Psychology and Behavioural Sciences Collection, Health Business Elite, Biomedica Reference Collection: Comprehensive Library, Information Science & Technology Abstracts, eBook Collection, Web of Science Core Collection: Citation Indexes and Social Sciences Citation Index, and grey literature. Eligibility criteria for selecting studies Studies were eligible for inclusion if they were full research papers employing qualitative methodology to explore patients’ perspectives of the medical primary–secondary care interface. Review methods The 7-step metaethnographic approach described by Noblit and Hare, which involves cross-interpretation between studies while preserving the context of the primary data. Results The search identified 690 articles, of which 39 were selected for full-text review. 20 articles were included in the systematic review that encompassed a total of 689 patients from 10 countries. 4 important areas specific to the primary–secondary care interface from the patients’ perspective emerged: barriers to care, communication, coordination, and ‘relationships and personal value’. Conclusions and implications of key findings Patients should be the focus of any transfer of care between primary and secondary systems. From their perspective, areas for improvement may be classified into four domains that should usefully guide future work aimed at improving quality at this important interface. Trial registration number

DEVELOPMENT OF TEACHER COMP ETENCES IN CREATING POWERFUL LEARNING ENVIRONMENTS IN VOCATIONAL SECONDARY EDUCATION

Directory of Open Access Journals (Sweden)

Inge PLACKLÉ

2010-01-01

Full Text Available Background: At the end of Vocational Secondary Education students should be able to solve authentic problems individually and in group. Powerful learning environments could enforce these learning processes. Research question: “Which critical desirable design principles can we define to create a powerful learning environment in Secondary Vocational Education ? Method: We combine different perspectives of teachers, students and researchers to build a shared model of learning environments, which will be perceived as more powerful by all stakeholders. Based on literature we selected design principles followed by organizing focus groups with teacher educators and teachers to further adapt these principles. Preliminary results: We determined eight design pr inciples: Authenticity learning environment, differentiation, adapted evaluation, self-directed learning, problem solving, teamwork, shared responsibility design learning environment and (labour identity develop ment. Each principle has been further clarified in indicators. This study is part of a larger research project in developing teacher competences in creating powe rful learning enviro nments in Vocational Secondary Education.

Determinants of Secondary School Learners Performance in Christian Religious Education in Lelan Sub County, Kenya

Science.gov (United States)

Akaranga, Stephen; Simiyu, Patrick Cheben

2016-01-01

In Kenya, Christian Religious Education is taught and examined by the Kenya National Examinations Council in the Kenya Certificate of Secondary Education at the end of the four years of Secondary Education cycle. The teaching of this subject in Secondary Schools ensures that learners are offered an opportunity to develop morally and spiritually…

Applications of Qualitative Microanalysis to the Determination of Secondary Species Associated with Uranium; Application de la microanalyse qualitative a la determination des especes secondaires d'uranium

Energy Technology Data Exchange (ETDEWEB)

Agrinier, H

1959-02-01

Microanalytical techniques are described which allow rapid determinations of secondary species associated with uranium. They consist in exposing the constituent elements of the ores by means of characteristic microchemical reactions. Because of their rapidity and the small amount of apparatus needed, these techniques can be used either in the field or in the laboratory. (author) [French] Les techniques de microanalyse decrites dans cet ouvrage permettent la determination rapide des especes secondaires d'uranium. Elles consistent a mettre en evidence les elements constitutifs des mineraux par des reactions microchimiques caracteristiques. En raison de leur rapidite et du peu de materiel qu'elles necessitent, ces techniques peuvent etre utilisees aussi bien sur le terrain qu'au laboratoire. (auteur)

Data Package for Secondary Waste Form Down-Selection-Cast Stone

International Nuclear Information System (INIS)

Serne, R. Jeffrey; Westsik, Joseph H.

2011-01-01

Available literature on Cast Stone and Saltstone was reviewed with an emphasis on determining how Cast Stone and related grout waste forms performed in relationship to various criteria that will be used to decide whether a specific type of waste form meets acceptance criteria for disposal in the Integrated Disposal Facility (IDF) at Hanford. After the critical review of the Cast Stone/Saltstone literature, we conclude that Cast Stone is a good candidate waste form for further consideration. Cast stone meets the target IDF acceptance criteria for compressive strength, no free liquids, TCLP leachate are below the UTS permissible concentrations and leach rates for Na and Tc-99 are suiteably low. The cost of starting ingredients and equipment necessary to generate Cast Stone waste forms with secondary waste streams are low and the Cast Stone dry blend formulation can be tailored to accommodate variations in liquid waste stream compositions. The database for Cast Stone short-term performance is quite extensive compared to the other three candidate waste solidification processes. The solidification of liquid wastes in Cast Stone is a mature process in comparison to the other three candidates. Successful production of Cast Stone or Saltstone has been demonstrated from lab-scale monoliths with volumes of cm3 through m3 sized blocks to 210-liter sized drums all the way to the large pours into vaults at Savannah River. To date over 9 million gallons of low activity liquid waste has been solidified and disposed in concrete vaults at Savannah River.

Amino acid code of protein secondary structure.

Science.gov (United States)

Shestopalov, B V

2003-01-01

The calculation of protein three-dimensional structure from the amino acid sequence is a fundamental problem to be solved. This paper presents principles of the code theory of protein secondary structure, and their consequence--the amino acid code of protein secondary structure. The doublet code model of protein secondary structure, developed earlier by the author (Shestopalov, 1990), is part of this theory. The theory basis are: 1) the name secondary structure is assigned to the conformation, stabilized only by the nearest (intraresidual) and middle-range (at a distance no more than that between residues i and i + 5) interactions; 2) the secondary structure consists of regular (alpha-helical and beta-structural) and irregular (coil) segments; 3) the alpha-helices, beta-strands and coil segments are encoded, respectively, by residue pairs (i, i + 4), (i, i + 2), (i, i = 1), according to the numbers of residues per period, 3.6, 2, 1; 4) all such pairs in the amino acid sequence are codons for elementary structural elements, or structurons; 5) the codons are divided into 21 types depending on their strength, i.e. their encoding capability; 6) overlappings of structurons of one and the same structure generate the longer segments of this structure; 7) overlapping of structurons of different structures is forbidden, and therefore selection of codons is required, the codon selection is hierarchic; 8) the code theory of protein secondary structure generates six variants of the amino acid code of protein secondary structure. There are two possible kinds of model construction based on the theory: the physical one using physical properties of amino acid residues, and the statistical one using results of statistical analysis of a great body of structural data. Some evident consequences of the theory are: a) the theory can be used for calculating the secondary structure from the amino acid sequence as a partial solution of the problem of calculation of protein three

Personality Type and Academic Achievement of Secondary School Students

Science.gov (United States)

Lawrence, Arul A. S.; Lawrence, John A.

2014-01-01

Personality is the man. The successful living of an individual, as a man, depends to a large extent on the academic achievement of that individual, as a student. This article attempts to find out personality type, academic achievement of secondary school students and relationship between them by selecting a sample of 300 secondary school students…

Knowledge and attitude of secondary school teachers in Enugu to ...

African Journals Online (AJOL)

Objective: To assess the knowledge and attitude to sex education among secondary school teachers in Enugu. Materials and Methods: A cross sectional study of 300 teachers drawn from nine randomly selected secondary schools in Enugu metropolis was carried out. Pre-tested self administered structured questionnaire ...

Determination of yield related traits of sesame genotypes selected from world collection and mutant material

International Nuclear Information System (INIS)

Silme, R. S.; Cagirgan, M. I.

2009-01-01

Sesame (Sesamum indicum L.) is an important plant of Turkey that secondary gen center and very used of food industry's a lot of area. Mutation breeding of sesame research continued coordinately with IAEA since 1993. it is aimed in these breeding programmes to improve lines that have dehiscent capsule, determinate growth and resistance to wilting traits. This study was conducted in Antalya City, at Akdeniz University Agricultural Faculty experiment fields under second crop conditions in 2007. At this study, 19 genotypes selected from world sesame collection, 4 mutant genotypes and 2 local cultivars were sown. The experiments were conducted according to Complete Randomized Block Design with three replications. It was found that first flowering date varied between 35 to 45 days, 50% flowering date from 39 to 54 days, last flowering date from 63 to 88 days, first capsule date from 42 to 51 days, first capsule height from 44 to 116 cm, plant height from 102 to 177 cm, number of branch per plant from 0.1 to 2.7, number of pod per plant from 28 to 63, number of seeds in capsule 2.3-4.3 g, 1000 seed weight ranged from 2.3 to 4.3 g, seed yield per da from 18 to 77 kg. The highest yield per da (77 kg/da) was obtained from mutant genotype, wt-5.

Determination of Endosperm Protein Secondary Structure in Hard Wheat Breeding Lines using Synchrotron Infrared Microspectroscopy

International Nuclear Information System (INIS)

Bonwell, E.; Fisher, T.; Fritz, A.; Wetzel, D.

2008-01-01

substantial variance in this feature and its determination allows the prediction of relative quality for breadmaking to be taken into consideration for subsequent steps in the wheat breeding process. Data treatments include deconvolution, modeling of the individual resulting bands that contribute to the amide I band to enable measurement of the relative amounts of both forms. Results with specimens representing multiple crop years of hard winter wheat breeding are reported. It is evident that a range is available for the breeder to choose from, that allows including this protein molecular structural attribute in the selection process.

Highly selective coulometric method and equipment for the automated determination of plutonium

International Nuclear Information System (INIS)

Jackson, D.D.; Hollen, R.M.; Roensch, F.R.; Rein, J.E.

1977-01-01

A highly selective, controlled-potential coulometric method has been developed for the determination of plutonium. An automated instrument, consisting of commercial electronic components under control of a programmable calculator, is being constructed. Half-cell potentials and interfering anions are listed

Production of and studies with secondary radioactive ion beams at Lise

International Nuclear Information System (INIS)

Mueller, A.C.

1990-01-01

The doubly achromatic spectrometer LISE, installed at GANIL has delivered secondary radioactive beams for the past 6 years. Essentially, it consists of by two dipole magnets selecting (in A/Z) and refocusing (achromatically) the projectile-like fragment-beams emitted at 0 0 . Important features of LISE and selected experimental results will be discussed. LISE was substantially upgraded, recently, by adding a Wien-filter, providing secondary radioactive beams of still increased intensity and isotopic purity. (6 figs)

Reconstitution of a secondary cell wall in a secondary cell wall-deficient Arabidopsis mutant.

Science.gov (United States)

Sakamoto, Shingo; Mitsuda, Nobutaka

2015-02-01

The secondary cell wall constitutes a rigid frame of cells in plant tissues where rigidity is required. Deposition of the secondary cell wall in fiber cells contributes to the production of wood in woody plants. The secondary cell wall is assembled through co-operative activities of many enzymes, and their gene expression is precisely regulated by a pyramidal cascade of transcription factors. Deposition of a transmuted secondary cell wall in empty fiber cells by expressing selected gene(s) in this cascade has not been attempted previously. In this proof-of-concept study, we expressed chimeric activators of 24 transcription factors that are preferentially expressed in the stem, in empty fiber cells of the Arabidopsis nst1-1 nst3-1 double mutant, which lacks a secondary cell wall in fiber cells, under the control of the NST3 promoter. The chimeric activators of MYB46, SND2 and ANAC075, as well as NST3, reconstituted a secondary cell wall with different characteristics from those of the wild type in terms of its composition. The transgenic lines expressing the SND2 or ANAC075 chimeric activator showed increased glucose and xylose, and lower lignin content, whereas the transgenic line expressing the MYB46 chimeric activator showed increased mannose content. The expression profile of downstream genes in each transgenic line was also different from that of the wild type. This study proposed a new screening strategy to identify factors of secondary wall formation and also suggested the potential of the artificially reconstituted secondary cell walls as a novel raw material for production of bioethanol and other chemicals. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.

UPLC-MS/MS method for determination of selected pyrrolizidine alkaloids in feed.

Science.gov (United States)

Bolechová, Martina; Cáslavský, Josef; Pospíchalová, Markéta; Kosubová, Petra

2015-03-01

Alkaloids known as secondary metabolites are grouped by typical structural characteristics into large families such as pyrrolizidine alkaloids (PAs) comprising more than 350 individual heterocyclic compounds. The PAs present a serious health risk to human and livestock; hence there is a need for methods that allow these dangerous plant toxins to be determined. In this study, a fast, reliable and sensitive approach is proposed to identify and quantify PAs in feed samples. PAs including monocrotaline, senkirkine, senecionine, seneciphylline and retrorsine were determined by ultra-performance liquid chromatography coupled with tandem mass spectrometry. Sample preparation was based on a modified QuEChERS approach. The mean recovery, precision, matrix effects and limits of quantification were assessed for three matrices within the method validation. The presented method was used to inspect 41 various feed samples, where the presence of PAs was expected. Roughages and feed for rabbits contained the highest levels of PAs, in general. Copyright © 2014 Elsevier Ltd. All rights reserved.

Evolution of the complementary sex-determination gene of honey bees: balancing selection and trans-species polymorphisms.

Science.gov (United States)

Cho, Soochin; Huang, Zachary Y; Green, Daniel R; Smith, Deborah R; Zhang, Jianzhi

2006-11-01

The mechanism of sex determination varies substantively among evolutionary lineages. One important mode of genetic sex determination is haplodiploidy, which is used by approximately 20% of all animal species, including >200,000 species of the entire insect order Hymenoptera. In the honey bee Apis mellifera, a hymenopteran model organism, females are heterozygous at the csd (complementary sex determination) locus, whereas males are hemizygous (from unfertilized eggs). Fertilized homozygotes develop into sterile males that are eaten before maturity. Because homozygotes have zero fitness and because common alleles are more likely than rare ones to form homozygotes, csd should be subject to strong overdominant selection and negative frequency-dependent selection. Under these selective forces, together known as balancing selection, csd is expected to exhibit a high degree of intraspecific polymorphism, with long-lived alleles that may be even older than the species. Here we sequence the csd genes as well as randomly selected neutral genomic regions from individuals of three closely related species, A. mellifera, Apis cerana, and Apis dorsata. The polymorphic level is approximately seven times higher in csd than in the neutral regions. Gene genealogies reveal trans-species polymorphisms at csd but not at any neutral regions. Consistent with the prediction of rare-allele advantage, nonsynonymous mutations are found to be positively selected in csd only in early stages after their appearances. Surprisingly, three different hypervariable repetitive regions in csd are present in the three species, suggesting variable mechanisms underlying allelic specificities. Our results provide a definitive demonstration of balancing selection acting at the honey bee csd gene, offer insights into the molecular determinants of csd allelic specificities, and help avoid homozygosity in bee breeding.

Shadow Education in Malaysia: Identifying the Determinants of Spending and Amount of Time Attending Private Supplementary Tutoring of Upper Secondary School Students

OpenAIRE

Chang Da Wan; Benedict Weerasena

2017-01-01

This paper examines the determinants of spending and the amount of time attending private supplementary tutoring, or commonly known as private tuition, in Malaysia. Based on 343 self-reported questionnaires with upper secondary students across three states in Malaysia and using multiple regression analysis, we identified ethnicity, father’s level of education and past academic performance as significant determinants of spending and amount of time attending private tuition. However, interestin...

Index Selection in Relational Databases

NARCIS (Netherlands)

Choenni, R.S.; Blanken, Henk; Chang, S.C.

Intending to develop a tool which aims to support the physical design of relational databases can not be done without considering the problem of index selection. Generally the problem is split into a primary and secondary index selection problem and the selection is done per table. Whereas much

Beef Cattle: Selection and Evaluation.

Science.gov (United States)

Clemson Univ., SC. Vocational Education Media Center.

Designed for secondary vocational agriculture students, this text provides an overview of selecting and evaluating beef cattle in Future Farmers of America livestock judging events. The first of four major sections addresses topics such as the ideal beef animal, selecting steers, selecting breeding animals, studying the animal systematically, and…

Absolute/convective secondary instabilities and the role of confinement in free shear layers

Science.gov (United States)

Arratia, Cristóbal; Mowlavi, Saviz; Gallaire, François

2018-05-01

We study the linear spatiotemporal stability of an infinite row of equal point vortices under symmetric confinement between parallel walls. These rows of vortices serve to model the secondary instability leading to the merging of consecutive (Kelvin-Helmholtz) vortices in free shear layers, allowing us to study how confinement limits the growth of shear layers through vortex pairings. Using a geometric construction akin to a Legendre transform on the dispersion relation, we compute the growth rate of the instability in different reference frames as a function of the frame velocity with respect to the vortices. This approach is verified and complemented with numerical computations of the linear impulse response, fully characterizing the absolute/convective nature of the instability. Similar to results by Healey on the primary instability of parallel tanh profiles [J. Fluid Mech. 623, 241 (2009), 10.1017/S0022112008005284], we observe a range of confinement in which absolute instability is promoted. For a parallel shear layer with prescribed confinement and mixing length, the threshold for absolute/convective instability of the secondary pairing instability depends on the separation distance between consecutive vortices, which is physically determined by the wavelength selected by the previous (primary or pairing) instability. In the presence of counterflow and moderate to weak confinement, small (large) wavelength of the vortex row leads to absolute (convective) instability. While absolute secondary instabilities in spatially developing flows have been previously related to an abrupt transition to a complex behavior, this secondary pairing instability regenerates the flow with an increased wavelength, eventually leading to a convectively unstable row of vortices. We argue that since the primary instability remains active for large wavelengths, a spatially developing shear layer can directly saturate on the wavelength of such a convectively unstable row, by

Determination of Selected Perfluorinated Alkyl Acids in ...

Science.gov (United States)

The 1996 amendments to the Safe Drinking Water Act (SDWA) required EPA to establish a Contaminant Candidate List (CCL), that contains a list of drinking water contaminants that the Agency will consider for future regulation. EPA must make a regulatory determination on a minimum of five contaminants every five years. The first CCL was published in 1998, and updates were anticipated every five years thereafter. One of the key pieces of information that must be available in order to make a regulatory determination is nationwide occurrence data for the chemical contaminants under consideration. Historically, EPA has collected the necessary occurrence data under its Unregulated Contaminant Monitoring Regulations (UCMR). Under the UCMR, monitoring is conducted at selected drinking water utilities for specific contaminants of interest. The chemical analyses are usually performed by the utilities or by commercial laboratories. To meet the requirements of monitoring under the UCMR program, the analytical methods developed should be specific, sensitive, and practical enough for application in commercial laboratories. This task will focus on the development of analytical methods for chemicals identified on future CCLs or emerging contaminants not yet listed on the CCL. These methods will be used for the collection of occurrence data under future UCMRs. The objective of this research effort is to develop analytical methods to be used to measure the occurrence of

Optimization of a spectrometry for energy-dispersive x-ray fluorescence analysis by x-ray tube in combination with secondary target for multielements determination of sediment samples

International Nuclear Information System (INIS)

Zaidi Embong; Husin Wagiran

1997-01-01

The design of an energy-dispersive X-ray fluorescence spectrometer equipped with a conventional X-ray tube and secondary target is described. The spectrometer system constructed in our laboratory consists of a semiconductor detector system, irradiation chamber and X-ray tube. Primary source from X-ray tube was used to produced secondary X-ray from selenium, molybdenum and cadmium targets. The fluorescence X-ray from the sample was detected using Si(Li) detector with resolution of 0. 175 keV (Mn-K(x). The spectrometer was used for determination of multi-elements with atomic number between 20 to 44 in river sediment samples. The X-ray spectrum, from the samples were analysed using computer software which was developed based on Marquardt method. Optimal conditions and detection limits are determined experimentally by variation of excitation parameters for each combination of secondary target and tube voltage

Secondary Instability of Second Modes in Hypersonic Boundary Layers

Science.gov (United States)

Li, Fei; Choudhari, Meelan M.; Chang, Chau-Lyan; White, Jeffery A.

2012-01-01

Second mode disturbances dominate the primary instability stage of transition in a number of hypersonic flow configurations. The highest amplification rates of second mode disturbances are usually associated with 2D (or axisymmetric) perturbations and, therefore, a likely scenario for the onset of the three-dimensionality required for laminar-turbulent transition corresponds to the parametric amplification of 3D secondary instabilities in the presence of 2D, finite amplitude second mode disturbances. The secondary instability of second mode disturbances is studied for selected canonical flow configurations. The basic state for the secondary instability analysis is obtained by tracking the linear and nonlinear evolution of 2D, second mode disturbances using nonlinear parabolized stability equations. Unlike in previous studies, the selection of primary disturbances used for the secondary instability analysis was based on their potential relevance to transition in a low disturbance environment and the effects of nonlinearity on the evolution of primary disturbances was accounted for. Strongly nonlinear effects related to the self-interaction of second mode disturbances lead to an upstream shift in the upper branch neutral location. Secondary instability computations confirm the previously known dominance of subharmonic modes at relatively small primary amplitudes. However, for the Purdue Mach 6 compression cone configuration, it was shown that a strong fundamental secondary instability can exist for a range of initial amplitudes of the most amplified second mode disturbance, indicating that the exclusive focus on subharmonic modes in the previous applications of secondary instability theory to second mode primary instability may not have been fully justified.

Problems Encountered by Religious Vocational Secondary School and Other Secondary School Students in Physical Education and Sports Activities

Science.gov (United States)

Bar, Mustafa; Yaman, Menzure Sibel; Hergüner, Gülten

2016-01-01

The study aimed to determine problems encountered by Religious Vocational Secondary School and other Secondary School students in physical education and sports activities and to compare these problems according to school type and gender. A questionnaire named "Problems encountered in attending to physical education and sports activities"…

Factors influencing subject selection in upper secondary education (Key Stage 4 for males and females in England

Directory of Open Access Journals (Sweden)

Joanne Vaughan

2015-08-01

Full Text Available Background Research to date has investigated the potential factors that influence students’ decisions in opting to study certain subjects during their upper secondary education. Trends in subject selection at this level (Key Stage 4 have been maintained over time and have consistently displayed comparable differences for males and females. It is recognised that males typically opt for subjects such as physical education and science, while females are traditionally noted as favouring the arts and humanities. These educational decisions may impact on future occupational directions. In light of recent initiatives, such as the English Baccalaureate, it is of interest to explore whether such measures have had an influence on this noted gender gap. Participants and procedure The present study investigates the potential predictors of subject selection, while controlling for gender, offering a specific focus on the education system in England. Attention is given to students’ perceived academic ability and attitude toward school, and how such factors may guide subject choice. Participants (N = 276 were students currently in the process of selecting optional modules for Key Stage 4 study. Results The findings demonstrate that female students are less likely than their male counterparts to opt for physical education (PE and business studies/information and communication technology (ICT as preferred modules, in comparison to ‘creative and performance’ subjects (reference category. Higher levels of reported masculinity were also shown to relate to the up-take of PE at Key Stage 4. Conclusions The implications of these findings are discussed in relation to existing research and practical contributions to the educational arena.

Efficacy of secondary isoniazid preventive therapy among ...

African Journals Online (AJOL)

Objective. To determine the efficacy of secondary preventive therapy against tuberculosis (TB) among goldminers working in South Africa. Design. An observational study. Methods. The incidence of recurrent TB was compared between two cohorts of HIV-infected miners: one cohort had received secondary preventive ...

Selective electrochemical determination of homocysteine in the presence of cysteine and glutathione

International Nuclear Information System (INIS)

Salehzadeh, Hamid; Mokhtari, Banafsheh; Nematollahi, Davood

2014-01-01

Graphical abstract: 3,5-Di-tert-buthylcatechol was used for the selective electrochemical determination of homocysteine in the presence of cysteine and glutathione at the glassy carbon and carbon nanotube modified glassy carbon electrode. - Highlights: • Selective electrochemical determination of homocysteine. • Catalytic electron transfer of 3,5-di-tert-buthylcatechol in the presence of homocysteine. • Michael type addition reaction of electrochemically generated 3,5-di-tert-buthyl-o-benzoquinone with glutathione. - Abstract: The electrochemical oxidation of 3,5-di-tert-buthylcatechol in the presence of homocysteine was used for the selective electrochemical determination of homocysteine in the presence of cysteine and glutathione at a glassy carbon and a glassy carbon electrode modified with carbon nanotube. The results revealed that the electrochemically generated 3,5-di-tert-butylcyclohexa-3,5-diene-1,2-dione exhibits high catalytic activity toward homocysteine oxidation at reduced over-potential and low catalytic activity for oxidation of cysteine. The catalytic activity 3,5-di-tert-butylcyclohexa-3,5-diene-1,2-dione toward cysteine was suppressed in the presence of 4-N,N-dimethylaminocinnamaldehyde. Contrary to homocysteine and cysteine, the reaction of glutathione with 3,5-di-tert-butylcyclohexa-3,5-diene-1,2-dione is a substituation reaction. This method exhibits three dynamic linear ranges of 2.5 to 10 μmol L −1 , 10 to 100 μmol L −1 and 100 to 1000 μmol L −1 , and a lower detection limit (3σ) of 0.89 ± 3.53% μmol L −1 for homocysteine

Chemistry of Secondary Polyphenols Produced during Processing of Tea and Selected Foods

Directory of Open Access Journals (Sweden)

Takashi Tanaka

2009-12-01

Full Text Available This review will discuss recent progress in the chemistry of secondary polyphenols produced during food processing. The production mechanism of the secondary polyphenols in black tea, whisky, cinnamon, and persimmon fruits will be introduced. In the process of black tea production, tea leaf catechins are enzymatically oxidized to yield a complex mixture of oxidation products, including theaflavins and thearubigins. Despite the importance of the beverage, most of the chemical constituents have not yet been confirmed due to the complexity of the mixture. However, the reaction mechanisms at the initial stages of catechin oxidation are explained by simple quinone–phenol coupling reactions. In vitro model experiments indicated the presence of interesting regio- and stereoselective reactions. Recent results on the reaction mechanisms will be introduced. During the aging of whisky in oak wood barrels, ellagitannins originating from oak wood are oxidized and react with ethanol to give characteristic secondary ellagitannins. The major part of the cinnamon procyanidins is polymerized by copolymerization with cinnamaldehyde. In addition, anthocyanidin structural units are generated in the polymer molecules by oxidation which accounts for the reddish coloration of the cinnamon extract. This reaction is related to the insolubilization of proanthocyanidins in persimmon fruits by condensation with acetaldehyde. In addition to oxidation, the reaction of polyphenols with aldehydes may be important in food processing.

A purple giraffe is faster than a purple elephant: Inconsistent phonology affects determiner selection in English

NARCIS (Netherlands)

Spalek, K.; Bock, K.; Schriefers, H.J.

2010-01-01

The form of a determiner is dependent on different contextual factors: in some languages grammatical number and grammatical gender determine the choice of a determiner variant. In other languages, the phonological onset of the element immediately following the determiner affects selection, too.

Accurate determination of interfacial protein secondary structure by combining interfacial-sensitive amide I and amide III spectral signals.

Science.gov (United States)

Ye, Shuji; Li, Hongchun; Yang, Weilai; Luo, Yi

2014-01-29

Accurate determination of protein structures at the interface is essential to understand the nature of interfacial protein interactions, but it can only be done with a few, very limited experimental methods. Here, we demonstrate for the first time that sum frequency generation vibrational spectroscopy can unambiguously differentiate the interfacial protein secondary structures by combining surface-sensitive amide I and amide III spectral signals. This combination offers a powerful tool to directly distinguish random-coil (disordered) and α-helical structures in proteins. From a systematic study on the interactions between several antimicrobial peptides (including LKα14, mastoparan X, cecropin P1, melittin, and pardaxin) and lipid bilayers, it is found that the spectral profiles of the random-coil and α-helical structures are well separated in the amide III spectra, appearing below and above 1260 cm(-1), respectively. For the peptides with a straight backbone chain, the strength ratio for the peaks of the random-coil and α-helical structures shows a distinct linear relationship with the fraction of the disordered structure deduced from independent NMR experiments reported in the literature. It is revealed that increasing the fraction of negatively charged lipids can induce a conformational change of pardaxin from random-coil to α-helical structures. This experimental protocol can be employed for determining the interfacial protein secondary structures and dynamics in situ and in real time without extraneous labels.

SAAS: Short Amino Acid Sequence - A Promising Protein Secondary Structure Prediction Method of Single Sequence

Directory of Open Access Journals (Sweden)

Zhou Yuan Wu

2013-07-01

Full Text Available In statistical methods of predicting protein secondary structure, many researchers focus on single amino acid frequencies in α-helices, β-sheets, and so on, or the impact near amino acids on an amino acid forming a secondary structure. But the paper considers a short sequence of amino acids (3, 4, 5 or 6 amino acids as integer, and statistics short sequence's probability forming secondary structure. Also, many researchers select low homologous sequences as statistical database. But this paper select whole PDB database. In this paper we propose a strategy to predict protein secondary structure using simple statistical method. Numerical computation shows that, short amino acids sequence as integer to statistics, which can easy see trend of short sequence forming secondary structure, and it will work well to select large statistical database (whole PDB database without considering homologous, and Q3 accuracy is ca. 74% using this paper proposed simple statistical method, but accuracy of others statistical methods is less than 70%.

Experimental design of membrane sensor for selective determination of phenazopyridine hydrochloride based on computational calculations

International Nuclear Information System (INIS)

Attia, Khalid A.M.; El-Abasawi, Nasr M.; Abdel-Azim, Ahmed H.

2016-01-01

Computational study has been done electronically and geometrically to select the most suitable ionophore to design a novel sensitive and selective electrochemical sensor for phenazopyridine hydrochloride (PAP). This study has revealed that sodium tetraphenylbarate (NaTPB) fits better with PAP than potassium tetrakis (KTClPB). The sensor design is based on the ion pair of PAP with NaTPB using dioctyl phthalate as a plasticizer. Under optimum conditions, the proposed sensor shows the slope of 59.5 mV per concentration decade in the concentration range of 1.0 × 10 −2 –1.0 × 10 −5 M with detection limit 8.5 × 10 −6 M. The sensor exhibits a very good selectivity for PAP with respect to a large number of interfering species as inorganic cations and sugars. The sensor enables track of determining PAP in the presence of its oxidative degradation product 2, 3, 6-Triaminopyridine, which is also its toxic metabolite. The proposed sensor has been successfully applied for the selective determination of PAP in pharmaceutical formulation. Also, the obtained results have been statistically compared to a reported electrochemical method indicating no significant difference between the investigated method and the reported one with respect to accuracy and precision. - Highlights: • Novel use of ISE for selective determination of phenazopyridine hydrochloride. • Investigating the degradation pathway of phenazopyridine with enough confirmation scan. • To avoid time-consuming and experimental trials, computational studies have been applied. • The proposed sensor shows high selectivity, reasonable detection limit and fast response.

Experimental design of membrane sensor for selective determination of phenazopyridine hydrochloride based on computational calculations

Energy Technology Data Exchange (ETDEWEB)

Attia, Khalid A.M.; El-Abasawi, Nasr M.; Abdel-Azim, Ahmed H., E-mail: Ahmed.hussienabdelazim@hotmil.com

2016-04-01

Computational study has been done electronically and geometrically to select the most suitable ionophore to design a novel sensitive and selective electrochemical sensor for phenazopyridine hydrochloride (PAP). This study has revealed that sodium tetraphenylbarate (NaTPB) fits better with PAP than potassium tetrakis (KTClPB). The sensor design is based on the ion pair of PAP with NaTPB using dioctyl phthalate as a plasticizer. Under optimum conditions, the proposed sensor shows the slope of 59.5 mV per concentration decade in the concentration range of 1.0 × 10{sup −2}–1.0 × 10{sup −5} M with detection limit 8.5 × 10{sup −6} M. The sensor exhibits a very good selectivity for PAP with respect to a large number of interfering species as inorganic cations and sugars. The sensor enables track of determining PAP in the presence of its oxidative degradation product 2, 3, 6-Triaminopyridine, which is also its toxic metabolite. The proposed sensor has been successfully applied for the selective determination of PAP in pharmaceutical formulation. Also, the obtained results have been statistically compared to a reported electrochemical method indicating no significant difference between the investigated method and the reported one with respect to accuracy and precision. - Highlights: • Novel use of ISE for selective determination of phenazopyridine hydrochloride. • Investigating the degradation pathway of phenazopyridine with enough confirmation scan. • To avoid time-consuming and experimental trials, computational studies have been applied. • The proposed sensor shows high selectivity, reasonable detection limit and fast response.

A study on secondary images in panoramic radiograph

International Nuclear Information System (INIS)

Cho, Dai Hee; Kim, Han Pyong

1984-01-01

This study was performed to observe the secondary images and to analyse the relationships between the primary and secondary images in panoramic radiograph. Using the Morita's Panex-EC panoramic x-ray machine and the human dry skull, the author analysed 17 radiographs which were selected from 65 radiographs of the dry skull that attached the radiopaque materials, and the attached regions of the radiopaque materials were the normal anatomical structures which were important and selected as a region for the evaluation of the secondary images effectively. The results were as follows; 1. The cervical vertebrae showed three images. The midline image was the most distorted and less clear, and bilateral images were slightly superimposed over the posterior border of the mandibular ramus. 2. In mandible, the secondary image of the posterior border of the ramus was superimposed on the opposite ramus region, and this image was elongated from the anterior border of the ramus to the lateral side of the posterior border of the ramus. The secondary image of the condyle was observed on the upper area of the coronoid process, the sigmoid notch and the condyle in opposite side. 3. In maxilla, the posterior region of the hard palate showed the secondary image on the lower part of the nasal cavity and the medial wall of the maxillary sinus. 4. The primary images of the occipital condyle and the mastoid process appeared on the same region, and only the secondary image of the occipital condyle was observed symmetrically on the opposite side with similar shape to the primary one. 5. In the cranial base, the anatomical structures of the midsagittal portions like a inferior border of the frontal sinus, sella turcica, inferior border of the sphenoid sinus and inferior border of the posterior part of the occipital bone showed the similar shape between the primary and secondary images symmetrically. 6. The petrous portion of the temporal bone showed the secondary image of the lateral side of

Effects of learning styles on career preferences of senior secondary ...

African Journals Online (AJOL)

The research investigated the effects of learning styles on career preferences of senior secondary school students in Jigawa State, Nigeria. A total of six hundred students, three hundred and sixty male, and two hundred and forty female were randomly selected from ten senior secondary schools across the state for the study ...

An assessment of Mathematics self – efficacy of secondary school ...

African Journals Online (AJOL)

The study examined an assessment of mathematics self-efficacy of secondary school students in Osun State. It drawn on 500 students comprising 250 males and 250 females randomly selected from 5 secondary schools in Osogbo. Their ages range between 11-17 years with a mean age of 14 years and a standard ...

Prevalence and impact of headache and migraine among secondary school students in Nigeria.

Science.gov (United States)

Ofovwe, Gabriel E; Ofili, Antoinette N

2010-11-01

A cross-sectional descriptive study to determine the overall, age and gender specific prevalence, trigger factors and impact of headache and migraine on quality of life of students attending secondary schools in Benin City, Nigeria. Six secondary schools were randomly selected from which students were randomly selected. A self-administered questionnaire was used to screen those with frequent headache, defined as at least 2 episodes of headache unrelated to fever or any underlying disease within the last 12 months or at least 1 episode in the last 6 months preceding the date questionnaire was administered. Another questionnaire based on the ICHD-2 criteria for diagnosis of migraine was then administered to those with frequent headaches. Data analysis was with SPSS 13.0 for Windows. One thousand six hundred and seventy-nine students aged 11-18 years were recruited. The overall prevalence of headache was 19.5%. The prevalence of migraine was 13.5%. Migraine was more common in girls than in boys at all ages. The most common trigger factors included emotional stress, sunlight or bright light, sleep deprivation, and hunger. Inability to participate in outdoor activities, household chores, and school absenteeism were the common impacts on the quality of life of among 76.8% of the migraineurs. Migraine is common and underdiagnosed among secondary school students in Benin City, Nigeria, and negatively impacts on the quality of life including school absenteeism. © 2010 American Headache Society.

Opportunistic transmitter selection for selfless overlay cognitive radios

KAUST Repository

Shaqfeh, Mohammad

2013-11-01

We propose an opportunistic strategy to grant channel access to the primary and secondary transmitters in causal selfless overlay cognitive radios over block-fading channels. The secondary transmitter helps the primary transmitter by relaying the primary messages opportunistically, aided by a buffer to store the primary messages temporarily. The optimal channel-aware transmitter- selection strategy is the solution of the maximization of the average secondary rate under the average primary rate requirement and the buffer stability constraints. Numerical results demonstrate the gains of the proposed opportunistic selection strategy. © 2013 IEEE.

Studies on the matched potential method for determining the selectivity coefficients of ion-selective electrodes based on neutral ionophores: experimental and theoretical verification.

Science.gov (United States)

Tohda, K; Dragoe, D; Shibata, M; Umezawa, Y

2001-06-01

A theory is presented that describes the matched potential method (MPM) for the determination of the potentiometric selectivity coefficients (KA,Bpot) of ion-selective electrodes for two ions with any charge. This MPM theory is based on electrical diffuse layers on both the membrane and the aqueous side of the interface, and is therefore independent of the Nicolsky-Eisenman equation. Instead, the Poisson equation is used and a Boltzmann distribution is assumed with respect to all charged species, including primary, interfering and background electrolyte ions located at the diffuse double layers. In this model, the MPM-selectivity coefficients of ions with equal charge (ZA = ZB) are expressed as the ratio of the concentrations of the primary and interfering ions in aqueous solutions at which the same amounts of the primary and interfering ions permselectively extracted into the membrane surface. For ions with unequal charge (ZA not equal to ZB), the selectivity coefficients are expressed as a function not only of the amounts of the primary and interfering ions permeated into the membrane surface, but also of the primary ion concentration in the initial reference solution and the delta EMF value. Using the measured complexation stability constants and single ion distribution coefficients for the relevant systems, the corresponding MPM selectivity coefficients can be calculated from the developed MPM theory. It was found that this MPM theory is capable of accurately and precisely predicting the MPM selectivity coefficients for a series of ion-selective electrodes (ISEs) with representative ionophore systems, which are generally in complete agreement with independently determined MPM selectivity values from the potentiometric measurements. These results also conclude that the assumption for the Boltzmann distribution was in fact valid in the theory. The recent critical papers on MPM have pointed out that because the MPM selectivity coefficients are highly concentration

Evaluating Accounting Software in Secondary Schools.

Science.gov (United States)

Chalupa, Marilyn

1988-01-01

The secondary accounting curriculum must be modified to include computers and software. Educators must be aware of the computer skills needed on the job and of the accounting software that is available. Software selection must be tailored to fit the curriculum and the time available. (JOW)

Secondary School Mathematics Teachers' Attitude in Teaching Mathematics

OpenAIRE

Mulugeta Atnafu

2014-01-01

The purpose of this study was to examine Addis Ababa secondary school mathematics teachers’ attitude in teaching mathematics. 148 mathematics teachers were selected using cluster sampling from Addis Ababa administration region. The study used survey method of data collection and it includes both quantitative and qualitative research methods. From the independent t-test, ANOVA, tukey test and regression analysis, some of the results obtained were: the majority of the secondary school mathemati...

Method for fluoride routine determination in urine of personnel exposed, by ion selective electrode

International Nuclear Information System (INIS)

Pires, M.A.F.; Bellintani, S.A.

1986-01-01

A simple, fast and sensible method is outlined for the determination of fluoride in urine of workers that handle fluorine compounds. The determination is based on the measurement of fluoride by ion selective electrode. Cationic interference like Ca ++ , Mg ++ , Fe +++ and Al +++ are complexed by EDTA and citric acid. (Author) [pt

RELATION BETWEEN EMOTIONAL INTELLIGENCE AND REASONING ABILITY OF HIGHER SECONDARY STUDENTS

OpenAIRE

C. Daisy Nambikkai; Dr. A.Veliappan

2017-01-01

The present study aims to find out the relationship between emotional intelligence and reasoning ability of the higher secondary students. Among the population, 724 samples of higher secondary students were selected randomly from Puducherry region. Findings of the study were i) significant difference is found between male and female higher secondary students in their reasoning ability in science on analogical reasoning, classification as reasoning, eclectic reasoning, deductive reasoning and ...

A general definition of the heritable variation that determines the potential of a population to respond to selection.

Science.gov (United States)

Bijma, Piter

2011-12-01

Genetic selection is a major force shaping life on earth. In classical genetic theory, response to selection is the product of the strength of selection and the additive genetic variance in a trait. The additive genetic variance reflects a population's intrinsic potential to respond to selection. The ordinary additive genetic variance, however, ignores the social organization of life. With social interactions among individuals, individual trait values may depend on genes in others, a phenomenon known as indirect genetic effects. Models accounting for indirect genetic effects, however, lack a general definition of heritable variation. Here I propose a general definition of the heritable variation that determines the potential of a population to respond to selection. This generalizes the concept of heritable variance to any inheritance model and level of organization. The result shows that heritable variance determining potential response to selection is the variance among individuals in the heritable quantity that determines the population mean trait value, rather than the usual additive genetic component of phenotypic variance. It follows, therefore, that heritable variance may exceed phenotypic variance among individuals, which is impossible in classical theory. This work also provides a measure of the utilization of heritable variation for response to selection and integrates two well-known models of maternal genetic effects. The result shows that relatedness between the focal individual and the individuals affecting its fitness is a key determinant of the utilization of heritable variance for response to selection.

Secondary Modern School Education: An Essay in Subjugation and Repression

Science.gov (United States)

Dash, Paul

2012-01-01

This article reflects on the inequity of secondary modern school education. In doing so it draws heavily on the experience of the author while highlighting inputs from others who failed the 11+ examination and were banished to such schools. The article argues that selection undermines the self-esteem of secondary modern school pupils and places…

A semi-supervised learning approach for RNA secondary structure prediction.

Science.gov (United States)

Yonemoto, Haruka; Asai, Kiyoshi; Hamada, Michiaki

2015-08-01

RNA secondary structure prediction is a key technology in RNA bioinformatics. Most algorithms for RNA secondary structure prediction use probabilistic models, in which the model parameters are trained with reliable RNA secondary structures. Because of the difficulty of determining RNA secondary structures by experimental procedures, such as NMR or X-ray crystal structural analyses, there are still many RNA sequences that could be useful for training whose secondary structures have not been experimentally determined. In this paper, we introduce a novel semi-supervised learning approach for training parameters in a probabilistic model of RNA secondary structures in which we employ not only RNA sequences with annotated secondary structures but also ones with unknown secondary structures. Our model is based on a hybrid of generative (stochastic context-free grammars) and discriminative models (conditional random fields) that has been successfully applied to natural language processing. Computational experiments indicate that the accuracy of secondary structure prediction is improved by incorporating RNA sequences with unknown secondary structures into training. To our knowledge, this is the first study of a semi-supervised learning approach for RNA secondary structure prediction. This technique will be useful when the number of reliable structures is limited. Copyright © 2015 Elsevier Ltd. All rights reserved.

Depression, anxiety and stress among higher secondary school students of Imphal, Manipur

Directory of Open Access Journals (Sweden)

K Sathish Kumar

2017-01-01

Full Text Available Introduction: Adolescence is a stressful period due to physical, psychological, sexual changes, and the presence of psychiatric disorders such as depression, anxiety, and stress at this stage of life is a matter of concern. Objectives: The objectives of the study were to determine the prevalences of depression, anxiety, and stress among higher secondary school students of Imphal and to determine the association between depression, anxiety, and stress and selected variables such as gender, standard, and religion. Materials and methods: From September 2014 to October 2014, a cross-sectional study was conducted among higher secondary school students of Imphal. The sample size was calculated to be 750. Seven schools were randomly selected, and all the students in that school were enrolled in the study. The study tool used was a questionnaire containing DASS (Depression Anxiety Stress Scale and sociodemographic characteristics. Results: The prevalences of depression, anxiety, and stress among 830 valid respondents were 19.5%, 24.4%, and 21.1%, respectively. In total, 81.6% of the respondents had at least one of the studied disorders and 34.7% of the respondents had all the three negative states. The prevalences of depression, anxiety, and stress were high among females and were significant for anxiety (P = 0.00 and stress (P = 0.04. The prevalences of depression and stress were significantly higher among 12th standard students with P-values of 0.00 and 0.02. Conclusion: The prevalences of depression, anxiety, and stress were high with anxiety and stress significantly higher among females, whereas prevalences of depression and stress were significantly higher among 12th standard students. More studies are recommended to determine the factors leading to these mental disorders.

Service time analysis of secondary packet transmission with opportunistic channel access

KAUST Repository

Usman, Muneer; Yang, Hongchuan; Alouini, Mohamed-Slim

2014-01-01

Cognitive radio transceiver can opportunistically access the underutilized channels of primary systems for new wireless services. The secondary transmission may be interrupted by the primary user's transmission. To facilitate the delay analysis of such secondary packet transmission, we study the resulting extended delivery time for a fixed-size secondary packet that includes both transmission time and waiting time. In particular we derive the exact distribution functions of extended delivery time of secondary transmission for both continuous sensing and periodic sensing cases. Selected numerical results are presented for illustrating the mathematical formulation.

Service time analysis of secondary packet transmission with opportunistic channel access

KAUST Repository

Usman, Muneer

2014-09-01

Cognitive radio transceiver can opportunistically access the underutilized channels of primary systems for new wireless services. The secondary transmission may be interrupted by the primary user\\'s transmission. To facilitate the delay analysis of such secondary packet transmission, we study the resulting extended delivery time for a fixed-size secondary packet that includes both transmission time and waiting time. In particular we derive the exact distribution functions of extended delivery time of secondary transmission for both continuous sensing and periodic sensing cases. Selected numerical results are presented for illustrating the mathematical formulation.

Breast cancer literacy among higher secondary students

DEFF Research Database (Denmark)

Bhandari, Parash Mani; Thapa, Kiran; Dhakal, Sarmila

2016-01-01

Background: Being the most common cancer among women worldwide, it is vital to be well-aware of breast cancer risk factors, symptoms and curability. However, few studies have reported breast cancer literacy in students using a validated instrument. Methods: A cross-sectional study was conducted...... among students of grades 11 and 12 from eleven higher secondary schools, one selected randomly from each ilaka of Parbat district. Questionnaire with modified Comprehensive Breast Cancer Knowledge Test was self-administered to 516 students. Knowledge score was categorized into two categories: 'good...... knowledge' and 'poor knowledge' taking median score as the cut-off. Chi-square test was used to determine difference in knowledge by socio-demographic factors, including gender. Results: Only 4.8 % of the students responded correctly to at least half of the items, and 1.4 % did not respond correctly to any...

Influence of selecting secondary settling tank sub-models on the calibration of WWTP models – A global sensitivity analysis using BSM2

DEFF Research Database (Denmark)

Ramin, Elham; Flores Alsina, Xavier; Sin, Gürkan

2014-01-01

This study investigates the sensitivity of wastewater treatment plant (WWTP) model performance to the selection of one-dimensional secondary settling tanks (1-D SST) models with first-order and second-order mathematical structures. We performed a global sensitivity analysis (GSA) on the benchmark...... simulation model No.2 with the input uncertainty associated to the biokinetic parameters in the activated sludge model No. 1 (ASM1), a fractionation parameter in the primary clarifier, and the settling parameters in the SST model. Based on the parameter sensitivity rankings obtained in this study......, the settling parameters were found to be as influential as the biokinetic parameters on the uncertainty of WWTP model predictions, particularly for biogas production and treated water quality. However, the sensitivity measures were found to be dependent on the 1-D SST models selected. Accordingly, we suggest...

A Purple Giraffe Is Faster than a Purple Elephant: Inconsistent Phonology Affects Determiner Selection in English

Science.gov (United States)

Spalek, Katharina; Bock, Kathryn; Schriefers, Herbert

2010-01-01

The form of a determiner is dependent on different contextual factors: in some languages grammatical number and grammatical gender determine the choice of a determiner variant. In other languages, the phonological onset of the element immediately following the determiner affects selection, too. Previous work has shown that the activation of…

THE PECULIARITIES OF NICKNAME STRUCTURE IN THE VICINITY OF VELIUONA: SECONDARY NICKNAMES

Directory of Open Access Journals (Sweden)

Ilona Mickienė

2014-10-01

Full Text Available The paper analyses 782 nicknames that were recorded at Veliuona vicinity during the project of the Institute of the Lithuanian Language “Modern Research of Geolinguistics in Lithuania: Optimisation of Network of Points and Interactive Spread of Dialectal Information”. The paper aims to identify the characteristic attributes of nickname structure. The analysis of the relations in derivation, i. e., tentatively distinguishing the derivation base and formant is the only way to talk about common word derivation. While researching the nicknames it is difficult to find such a universal criterion in derivation which would enable the distribution of nicknames into the primary and the secondary ones due to the fact that when a nickname and its appellative derivation motivation coincides the confusion arises. Thus, the paper invokes the structural analysis of nicknames to find universal criteria that would enable the distinction of nicknames into the primary and the secondary. The article eliminates the primary nicknames that do not differ from the motivational word, 241 secondary nickname is being researched ant structurally analysed. The structural analysis discloses a proper structure and common words being selected for nickname creation. Structurally analysing the secondary nicknames, the nicknames with suffix, inflection, mixed structure, compound, composite and phrasal nicknames were distinguished. It was determined that in vacinity of Veliuona the nicknames with suffix and inflection are mostly used.

Assessing Principals' Quality Assurance Strategies in Osun State Secondary Schools, Nigeria

Science.gov (United States)

Fasasi, Yunus Adebunmi; Oyeniran, Saheed

2014-01-01

This paper examined principals' quality assurance strategies in secondary schools in Osun State, Nigeria. The study adopted a descriptive survey research design. Stratified random sampling technique was used to select 10 male and 10 female principals, and 190 male and190 female teachers. "Secondary School Principal Quality Assurance…

Developing the Conflicts Management Model for School Administrators of Secondary School under the Office of Secondary Educational Service Area 20

Directory of Open Access Journals (Sweden)

Pornpan Ruangrit

2017-09-01

Full Text Available This study aimed to 1 investigate the cause of conflict which in the secondary schools under the Secondary School under the Office of Secondary Educational Service Area 20, 2 study the conflict management method which administrators applied in Secondary School under the Office of Secondary Educational Service Area 20, and 3 develop conflict management model for Secondary School under the Office of Secondary Educational Service Area 20. The participants were 115 school administrators (44 school directors and 71 deputy directors which were selected by random sampling technique. The research instruments included a questionnaire, which reliability value was 0.97, and an interview schedule that were administered to the respondents. The data were analyzed by frequency, percentage, mean, and standard deviation. The result of the study showed that: 1. the causes of conflict in Secondary School under the Office of Secondary Educational Service Area 20 in overall was at the high level with the mean of 4.21, the internal conflict was at the high level with the mean of 4.22, and the external conflict was at the high level with the mean of 4.19. 2. Overall, conflict management method used by administrators in Secondary School under the Office of Secondary Educational Service Area 20was at a high level. Considering each aspect, the compromising method was the highest level at 4.48. 3. Developing conflict management model in Secondary School under the Office of Secondary Educational Service Area 20 were the collaboration and making understand method. These should be used for conflict management to achieve the success and to reach the standard which including responsibility, accountability, equality, teamwork, and communication competence.

Secondary standards laboratories for ionizing radiation calibrations: the national laboratory interests

International Nuclear Information System (INIS)

Roberson, P.L.; Campbell, G.W.

1984-11-01

The national laboratories are probable candidates to serve as secondary standards laboratories for the federal sector. Representatives of the major Department of Energy laboratories were polled concerning attitudes toward a secondary laboratory structure. Generally, the need for secondary laboratories was recognized and the development of such a program was encouraged. The secondary laboratories should be reviewed and inspected by the National Bureau of Standards. They should offer all of the essential, and preferably additional, calibration services in the field of radiological health protection. The selection of secondary laboratories should be based on economic and geographic criteria and/or be voluntary. 1 ref., 2 tabs

Direct electron crystallographic determination of zeolite zonal structures

International Nuclear Information System (INIS)

Dorset, Douglas L.; Gilmore, Christopher J.; Jorda, Jose Luis; Nicolopoulos, Stavros

2007-01-01

The prospect for improving the success of ab initio zeolite structure investigations with electron diffraction data is evaluated. First of all, the quality of intensities obtained by precession electron diffraction at small hollow cone illumination angles is evaluated for seven representative materials: ITQ-1, ITQ-7, ITQ-29, ZSM-5, ZSM-10, mordenite, and MCM-68. It is clear that, for most examples, an appreciable fraction of a secondary scattering perturbation is removed by precession at small angles. In one case, ZSM-10, it can also be argued that precession diffraction produces a dramatically improved 'kinematical' data set. There seems to no real support for application of a Lorentz correction to these data and there is no reason to expect for any of these samples that a two-beam dynamical scattering relationship between structure factor amplitude and observed intensity should be valid. Removal of secondary scattering by the precession mode appears to facilitate ab initio structure analysis. Most zeolite structures investigated could be solved by maximum entropy and likelihood phasing via error-correcting codes when precession data were used. Examples include the projected structure of mordenite that could not be determined from selected area data alone. One anomaly is the case of ZSM-5, where the best structure determination in projection is made from selected area diffraction data. In a control study, the zonal structure of SSZ-48 could be determined from selected area diffraction data by either maximum entropy and likelihood or traditional direct methods. While the maximum entropy and likelihood approach enjoys some advantages over traditional direct methods (non-dependence on predicted phase invariant sums), some effort must be made to improve the figures of merit used to identify potential structure solutions

Full-Duplex opportunistic relay selection in future spectrum-sharing networks

KAUST Repository

Khafagy, Mohammad Galal; Alouini, Mohamed-Slim; Aï ssa, Sonia

2015-01-01

We propose and analyze the performance of full-duplex relay selection in primary/secondary spectrum-sharing networks. Contrary to half-duplex relaying, full-duplex relaying (FDR) enables simultaneous listening/forwarding at the secondary relay, thereby allowing for a higher spectral efficiency. However, since the source and relay simultaneously transmit in FDR, their superimposed signal at the primary receiver should now satisfy the existing interference constraint which can considerably limit the secondary network throughput. In this regard, relay selection can offer an adequate solution to boost the secondary throughput while satisfying the imposed interference limit. We first analyze the performance of opportunistic relay selection among a cluster of full-duplex decode-and-forward relays with self-interference by deriving the exact cumulative distribution function of its end-to-end signal-to-noise ratio. Second, we evaluate the end-to-end performance of relay selection with interference constraints due to the presence of a primary receiver. Finally, the presented exact theoretical findings are verified by numerical simulations.

Full-Duplex opportunistic relay selection in future spectrum-sharing networks

KAUST Repository

Khafagy, Mohammad Galal

2015-06-01

We propose and analyze the performance of full-duplex relay selection in primary/secondary spectrum-sharing networks. Contrary to half-duplex relaying, full-duplex relaying (FDR) enables simultaneous listening/forwarding at the secondary relay, thereby allowing for a higher spectral efficiency. However, since the source and relay simultaneously transmit in FDR, their superimposed signal at the primary receiver should now satisfy the existing interference constraint which can considerably limit the secondary network throughput. In this regard, relay selection can offer an adequate solution to boost the secondary throughput while satisfying the imposed interference limit. We first analyze the performance of opportunistic relay selection among a cluster of full-duplex decode-and-forward relays with self-interference by deriving the exact cumulative distribution function of its end-to-end signal-to-noise ratio. Second, we evaluate the end-to-end performance of relay selection with interference constraints due to the presence of a primary receiver. Finally, the presented exact theoretical findings are verified by numerical simulations.

Sodium dithionite as a selective demasking agent for the complexometric determination of thallium

Directory of Open Access Journals (Sweden)

PRAKASH SHETTY

2005-11-01

Full Text Available Sodium dithionite is proposed as a new demasking agent for the rapid and selective complexometric determination of thallium(III. In the presence of diverse metal ions, thallium (III was first complexed with excess EDTA and the surplus EDTAwas then titrated with a standard zinc sulphate solution at pH 5–6 (hexamine buffer using Xylenol Orange as the indicator. The EDTAequivalent to thallium was then released selectively with sodium dithionite and back titrated with a standard zinc sulphate solution as before. Reproducible and accurate results were obtained in the range 4–100 mg of thallium with a relative error of ±27 % and a coefficient of variation (n = 6 of not more than 0.30 %. The effects of various diverse ions were studied. The method was applied to the determination of thallium in its complexes and in alloys.

Evidence of selective reporting bias in hematology journals: A systematic review.

Science.gov (United States)

Wayant, Cole; Scheckel, Caleb; Hicks, Chandler; Nissen, Timothy; Leduc, Linda; Som, Mousumi; Vassar, Matt

2017-01-01

Selective reporting bias occurs when chance or selective outcome reporting rather than the intervention contributes to group differences. The prevailing concern about selective reporting bias is the possibility of results being modified towards specific conclusions. In this study, we evaluate randomized controlled trials (RCTs) published in hematology journals, a group in which selective outcome reporting has not yet been explored. Our primary goal was to examine discrepancies between the reported primary and secondary outcomes in registered and published RCTs concerning hematological malignancies reported in hematology journals with a high impact factor. The secondary goals were to address whether outcome reporting discrepancies favored statistically significant outcomes, whether a pattern existed between the funding source and likelihood of outcome reporting bias, and whether temporal trends were present in outcome reporting bias. For trials with major outcome discrepancies, we contacted trialists to determine reasons for these discrepancies. Trials published between January 1, 2010 and December 31, 2015 in Blood; British Journal of Haematology; American Journal of Hematology; Leukemia; and Haematologica were included. Of 499 RCTs screened, 109 RCTs were included. Our analysis revealed 118 major discrepancies and 629 total discrepancies. Among the 118 discrepancies, 30 (25.4%) primary outcomes were demoted, 47 (39.8%) primary outcomes were omitted, and 30 (25.4%) primary outcomes were added. Three (2.5%) secondary outcomes were upgraded to a primary outcome. The timing of assessment for a primary outcome changed eight (6.8%) times. Thirty-one major discrepancies were published with a P-value and twenty-five (80.6%) favored statistical significance. A majority of authors whom we contacted cited a pre-planned subgroup analysis as a reason for outcome changes. Our results suggest that outcome changes occur frequently in hematology trials. Because RCTs ultimately

Sensitive and selective magnetoimmunosensing platform for determination of the food allergen Ara h 1

International Nuclear Information System (INIS)

Montiel, V. Ruiz-Valdepeñas; Campuzano, S.; Pellicanò, A.; Torrente-Rodríguez, R.M.; Reviejo, A.J.; Cosio, M.S.; Pingarrón, J.M.

2015-01-01

Highlights: • First amperometric magnetoimmunosensor for Ara h 1 determination. • Sensitive and selective detection of Ara h 1 in 2 h. • LOD of 6.3 ng mL −1 . • Determinations in food extracts and saliva. • Potential applicability in food safety and consumer protection. - Abstract: A highly sensitive disposable amperometric immunosensor based on the use of magnetic beads (MBs) is described for determination of Ara h 1, the major peanut allergen, in only 2 h. The approach uses a sandwich configuration involving selective capture and biotinylated detector antibodies and carboxylic acid-modified MBs (HOOC-MBs). The MBs bearing the immunoconjugates are captured by a magnet placed under the surface of a disposable screen-printed carbon electrode (SPCE) and the affinity reactions are monitored amperometrically at −0.20 V (vs a Ag pseudo-reference electrode) in the presence of hydroquinone (HQ) as electron transfer mediator and upon addition of H 2 O 2 as the enzyme substrate. The developed immunosensor exhibits a wide range of linearity between 20.8 and 1000.0 ng mL −1 Ara h 1, a detection limit of 6.3 ng mL −1 , a great selectivity, a good reproducibility with a RSD of 6.3% for six different immunosensors and a useful lifetime of 25 days. The usefulness of the immunosensor was demonstrated by determining Ara h 1 in different matrices (food extracts and saliva). The results correlated properly with those provided by a commercial ELISA method offering a reliable and promising analytical screening tool in the development of user-friendly devices for on-site determination of Ara h 1

Sensitive and selective magnetoimmunosensing platform for determination of the food allergen Ara h 1

Energy Technology Data Exchange (ETDEWEB)

Montiel, V. Ruiz-Valdepeñas, E-mail: victor_lega90@hotmail.com [Departamento de Química Analítica, Facultad de CC. Químicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Campuzano, S., E-mail: susanacr@quim.ucm.es [Departamento de Química Analítica, Facultad de CC. Químicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Pellicanò, A., E-mail: alessandro.pellicano@unimi.it [Department of Food, Environmental and Nutritional Sciences (DEFENS), University of Milan, Via Celoria 2, 20133 Milan (Italy); Torrente-Rodríguez, R.M., E-mail: rebeca.magnolia@gmail.com [Departamento de Química Analítica, Facultad de CC. Químicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Reviejo, A.J., E-mail: reviejo@quim.ucm.es [Departamento de Química Analítica, Facultad de CC. Químicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Cosio, M.S., E-mail: stella.cosio@unimi.it [Department of Food, Environmental and Nutritional Sciences (DEFENS), University of Milan, Via Celoria 2, 20133 Milan (Italy); Pingarrón, J.M., E-mail: pingarro@quim.ucm.es [Departamento de Química Analítica, Facultad de CC. Químicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain)

2015-06-23

Highlights: • First amperometric magnetoimmunosensor for Ara h 1 determination. • Sensitive and selective detection of Ara h 1 in 2 h. • LOD of 6.3 ng mL{sup −1}. • Determinations in food extracts and saliva. • Potential applicability in food safety and consumer protection. - Abstract: A highly sensitive disposable amperometric immunosensor based on the use of magnetic beads (MBs) is described for determination of Ara h 1, the major peanut allergen, in only 2 h. The approach uses a sandwich configuration involving selective capture and biotinylated detector antibodies and carboxylic acid-modified MBs (HOOC-MBs). The MBs bearing the immunoconjugates are captured by a magnet placed under the surface of a disposable screen-printed carbon electrode (SPCE) and the affinity reactions are monitored amperometrically at −0.20 V (vs a Ag pseudo-reference electrode) in the presence of hydroquinone (HQ) as electron transfer mediator and upon addition of H{sub 2}O{sub 2} as the enzyme substrate. The developed immunosensor exhibits a wide range of linearity between 20.8 and 1000.0 ng mL{sup −1} Ara h 1, a detection limit of 6.3 ng mL{sup −1}, a great selectivity, a good reproducibility with a RSD of 6.3% for six different immunosensors and a useful lifetime of 25 days. The usefulness of the immunosensor was demonstrated by determining Ara h 1 in different matrices (food extracts and saliva). The results correlated properly with those provided by a commercial ELISA method offering a reliable and promising analytical screening tool in the development of user-friendly devices for on-site determination of Ara h 1.

Spectrum Band Selection in Delay-QoS Constrained Cognitive Radio Networks

KAUST Repository

Yang, Yuli

2014-01-01

In this paper, a cognitive radio (CR) network with multiple spectrum bands available for secondary users (SUs) is considered. For the SU\\'s active spectrum-band selection, two criteria are developed. One is to select the band with the highest secondary channel power gain, and the other is to select the band with the lowest interference channel power gain to primary users (PUs). With the quality-of-service (QoS) requirement concerning delay, the effective capacity (EC) behaviors over secondary links are investigated for both criteria under two spectrum-sharing constraints. To begin by presenting full benefits in these criteria, the constraint imposed on the secondary transmitter (ST) is the average interference limitation to PUs only. Furthermore, taking into account the ST\\'s battery/energy budget, the ST is imposed by joint constraints on its average interference to PUs, as well as on its own average transmit power. For either constraint, we formulate the ST\\'s optimal transmit power allocation to maximize the SU\\'s EC with both band-selection criteria and, correspondingly, obtain the secondary\\'s power allocation and maximum EC in closed forms. Numerical results demonstrated subsequently substantiate the validity of our derivations and provide a powerful tool for the spectrum-band selection in CR networks with multiple bands available. © 1967-2012 IEEE.

Selective methods for polyphenols and sulphur dioxide determination in wines.

Science.gov (United States)

García-Guzmán, Juan J; Hernández-Artiga, María P; Palacios-Ponce de León, Lourdes; Bellido-Milla, Dolores

2015-09-01

A critical review to the methods recommended by international bodies and widely used in the winery industry and research studies was performed. A Laccase biosensor was applied to the selective determination of polyphenols in wines. The biosensor response was characterised and it responds mainly to o-diphenols which are the principal polyphenols responsible for the stability and sensory qualities of wines. The spectrophotometric method to determine free and total sulphur dioxide recommended for beers was applied directly to wines. A sampling of 14 red and white wines was performed and they were analysed for biosensor polyphenol index (IBP) and sulphur dioxide concentration (SO2). The antioxidant capacity by the ABTS(+) spectrophotometric method was also determined. A correlation study was performed to elucidate the influence of the polyphenols and SO2 on the wines stability. High correlations were found between IBP and antioxidant capacity and low correlation between SO2 and antioxidant capacity. To evaluate the benefits of wine drinking a new parameter (IBP/SO2) is proposed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Performance Analysis of Secondary Link with Cross-Layer Design and Cooperative Relay in Cognitive Radio Networks

KAUST Repository

Ma, Hao

2012-06-01

In this thesis, we investigate two different system infrastructures in underlay cognitive radio network, in which two popular techniques, cross-layer design and cooperative communication, are considered, respectively. In particular, we introduce the Aggressive Adaptive Modulation and Coding (A-AMC) into the cross-layer design and achieve the optimal boundary points in closed form to choose the AMC and A-AMC transmission modes by taking into account the Channel State Information (CSI) from the secondary transmitter to both the primary receiver and the secondary receiver. What’s more, for the cooperative communication design, we consider three different relay selection schemes: Partial Relay Selection, Opportunistic Relay Selection and Threshold Relay Selection. The Probability Density Functions (PDFs) of the Signal-to- Noise Ratio (SNR) in each hop for different selection schemes are provided, and then the exact closed-form expressions for the end-to-end packet loss rate in the secondary link considering the cooperation of the Decode-and-Forward (DF) relay for different relay selection schemes are derived.

The selective Cox-2 inhibitor Celecoxib suppresses angiogenesis and growth of secondary bone tumors: An intravital microscopy study in mice

International Nuclear Information System (INIS)

Klenke, Frank Michael; Gebhard, Martha-Maria; Ewerbeck, Volker; Abdollahi, Amir; Huber, Peter E; Sckell, Axel

2006-01-01

The inhibition of angiogenesis is a promising strategy for the treatment of malignant primary and secondary tumors in addition to established therapies such as surgery, chemotherapy, and radiation. There is strong experimental evidence in primary tumors that Cyclooxygenase-2 (Cox-2) inhibition is a potent mechanism to reduce angiogenesis. For bone metastases which occur in up to 85% of the most frequent malignant primary tumors, the effects of Cox-2 inhibition on angiogenesis and tumor growth remain still unclear. Therefore, the aim of this study was to investigate the effects of Celecoxib, a selective Cox-2 inhibitor, on angiogenesis, microcirculation and growth of secondary bone tumors. In 10 male severe combined immunodeficient (SCID) mice, pieces of A549 lung carcinomas were implanted into a newly developed cranial window preparation where the calvaria serves as the site for orthotopic implantation of the tumors. From day 8 after tumor implantation, five animals (Celecoxib) were treated daily with Celecoxib (30 mg/kg body weight, s.c.), and five animals (Control) with the equivalent amount of the CMC-based vehicle. Angiogenesis, microcirculation, and growth of A549 tumors were analyzed by means of intravital microscopy. Apoptosis was quantified using the TUNEL assay. Treatment with Celecoxib reduced both microvessel density and tumor growth. TUNEL reaction showed an increase in apoptotic cell death of tumor cells after treatment with Celecoxib as compared to Controls. Celecoxib is a potent inhibitor of tumor growth of secondary bone tumors in vivo which can be explained by its anti-angiogenic and pro-apoptotic effects. The results indicate that a combination of established therapy regimes with Cox-2 inhibition represents a possible application for the treatment of bone metastases

Secondary Waste Form Down-Selection Data Package—DuraLith

Energy Technology Data Exchange (ETDEWEB)

Mattigod, Shas V.; Westsik, Joseph H.

2011-09-15

This data package developed for the DuraLith wasteform includes information available in the open literature and from data obtained from testing currently underway. DuraLith is an alkali-activated geopolymer waste form developed by the Vitreous State Laboratory at The Catholic University of America (VSL-CUA) for encapsulating liquid radioactive waste. A DuraLith waste form developed for treating Hanford secondary waste liquids is prepared by alkali-activation of a mixture of ground blast furnace slag and metakaolinite with sand used as a filler material. Based on optimization tests, solid waste loading of {approx}7.5% and {approx}14.7 % has been achieved using the Hanford secondary waste S1 and S4 simulants, respectively. The Na loading in both cases is equivalent to {approx}6 M. Some of the critical parameters for the DuraLith process include, hydrogen generation and heat evolution during activator solution preparation using the waste simulant, heat evolution during and after mixing the activator solution with the dry ingredients, and a working window of {approx}20 minutes to complete the pouring of the DuraLith mixture into molds. Results of the most recent testing indicated that the working window can be extended to {approx}30 minutes if 75 wt% of the binder components, namely, blast furnace slag and metakaolin are replaced by Class F fly ash. A preliminary DuraLith process flow sheet developed by VSL-CUA for processing Hanford secondary waste indicated that 10 to 22 waste monoliths (each 48 ft3 in volume) can be produced per day. There are no current pilot-scale or full-scale DuraLith plants under construction or in operation; therefore, the cost of DuraLith production is unknown. The results of the non-regulatory leach tests, EPA Draft 1313 and 1316, Waste Simulant S1-optimized DuraLith specimens indicated that the concentrations of RCRA metals (Ag, Cd, Cr, Hg, and Pb) in the leachates were well below the Universal Treatment Standard limits in 40 CFR 268

Rapid determination method of radiocesium in sea water by cesium-selective resin

International Nuclear Information System (INIS)

Nakaoka, A.; Yokoyama, H.; Fukushima, M.; Takagi, S.

1980-01-01

A rapid and precise method of determining radiocesium corresponding to 5 mrem/y (the Japan AEC's guideline) was proposed. The development and practical performance of cesium-selective resin and the determination method are described in this paper. The resin was prepared by the formation of ammonium molybdophosphate in the structure of Amberlite XAD-7 resin. It took only 3 hours to carry out all the procedures the authors proposed. This value represents 1/10 to 1/2 of the time of the conventional method. The concentration of 137 Cs and 134 Cs in sea water was determined to be 0.13 to 0.16 pCi/l and less than 7.1x10 -2 pCi/l, respectively. (author)

Secondary cartilage revealed in a non-avian dinosaur embryo.

Directory of Open Access Journals (Sweden)

Alida M Bailleul

Full Text Available The skull and jaws of extant birds possess secondary cartilage, a tissue that arises after bone formation during embryonic development at articulations, ligamentous and muscular insertions. Using histological analysis, we discovered secondary cartilage in a non-avian dinosaur embryo, Hypacrosaurus stebingeri (Ornithischia, Lambeosaurinae. This finding extends our previous report of secondary cartilage in post-hatching specimens of the same dinosaur species. It provides the first information on the ontogeny of avian and dinosaurian secondary cartilages, and further stresses their developmental similarities. Secondary cartilage was found in an embryonic dentary within a tooth socket where it is hypothesized to have arisen due to mechanical stresses generated during tooth formation. Two patterns were discerned: secondary cartilage is more restricted in location in this Hypacrosaurus embryo, than it is in Hypacrosaurus post-hatchlings; secondary cartilage occurs at far more sites in bird embryos and nestlings than in Hypacrosaurus. This suggests an increase in the number of sites of secondary cartilage during the evolution of birds. We hypothesize that secondary cartilage provided advantages in the fine manipulation of food and was selected over other types of tissues/articulations during the evolution of the highly specialized avian beak from the jaws of their dinosaurian ancestors.

Nutritional environment at secondary schools in Bloemfontein, South ...

African Journals Online (AJOL)

Objective: The objective was to determine the nutritional environment at secondary schools in Bloemfontein, Free State province. Design: This was a cross-sectional, descriptive study. Subjects and setting: The subjects were secondary school principals in Bloemfontein, Free State province, in 2006. Method: Principals of 10 ...

Further Results on Extended Delivery Time for Secondary Packet Transmission

KAUST Repository

Usman, Muneer

2017-07-10

Cognitive radio transceiver can opportunistically access the underutilized spectrum resource of primary systems for new wireless services. With interweave cognitive implementation, secondary transmission may be interrupted by primary transmission. To facilitate the packet delay analysis of such secondary transmission, we study the extended delivery time of secondary packet transmission. In particular, we derive the exact distribution function of extended delivery time of a fixed-size secondary packet with non-work-preserving strategy, where interrupted packets must be repeated. We also analyze the effect of imperfect periodic sensing, i.e., the secondary user periodically senses the spectrum for availability, with a chance of missing an available channel on a certain sensing attempt. These results complement previous work on work-preserving strategy with perfect sensing. Selected numerical and simulation results are presented for verifying the mathematical formulation.

Aging, selective attention, and feature integration.

Science.gov (United States)

Plude, D J; Doussard-Roosevelt, J A

1989-03-01

This study used feature-integration theory as a means of determining the point in processing at which selective attention deficits originate. The theory posits an initial stage of processing in which features are registered in parallel and then a serial process in which features are conjoined to form complex stimuli. Performance of young and older adults on feature versus conjunction search is compared. Analyses of reaction times and error rates suggest that elderly adults in addition to young adults, can capitalize on the early parallel processing stage of visual information processing, and that age decrements in visual search arise as a result of the later, serial stage of processing. Analyses of a third, unconfounded, conjunction search condition reveal qualitatively similar modes of conjunction search in young and older adults. The contribution of age-related data limitations is found to be secondary to the contribution of age decrements in selective attention.

Problems of implementing continuous assessment in secondary ...

African Journals Online (AJOL)

The paper examined problems of implementing continuous assessment in secondary schools in Obowo local government area of Imo State, Nigeria. Data were collected with the aid of a structured questionnaire administered to 100 randomly selected respondents in the study area. Descriptive statistics were used for data ...

Optimization of secondary side water chemistry in TQNPC

International Nuclear Information System (INIS)

Fang Lan

2007-01-01

This article briefly introduces the types of corrosion that may be happened on steam generator heat exchange tubes in Qinshan CANDU6 nuclear power station and chemical effects on corrosion. The water chemistry optimization on minimzing deposition and corrosion of steam generators are introduced. The article summarizes the experiences of plant chemistry control and morpholine operation, providing guidance for optimizing secondary side water chemistry in the future, giving reference on selection of secondary side alkali agent and setting water chemistry specifications for other nuclear power stations. (authors)

[Urban alcohol consumption among secondary school students in Côte d'Ivoire].

Science.gov (United States)

Dagnan, N'Cho Simplice; Zengbé-Acray, Pétronille; Ekou, Franck Kokora; Kouassi, Damus Paquin; Sablé, Parfait Stéphane; Oussou, Konan Roland; Cissé, Sanansi; Soumahoro, Sory Ibrahim

2014-01-01

Alcohol consumption is both a health and social risk factor. Few studies have been conducted on alcohol use among students in Côte d'Ivoire. This study was designed to determine factors associated with alcohol consumption among secondary school students in Côte d'Ivoire. A cross-sectional study was conducted in May 2011 among public secondary school students in Abidjan. One class for each year of study was randomly selected. Multivariate analysis was conducted between alcohol consumption and independent variables. A total of 316 students participated in the survey. The mean age (SD) of the study population was 16.1 (2.7) years. One hundred and fourteen respondents (36.1%) reported having already drunk alcohol. Age of first alcohol consumption was 10-14 years among girls (48.8%) and 15-19 years among boys (49.3%). Multivariate logistic regression identified the following factors associated with alcohol use among students: Christian religion, more pocket money, living with parents who drink alcohol and the student's perception of alcohol as a refreshing drink or having an antidepressant effect. In the light of the determinants of alcohol consumption and the students'suggestions in our study, it appears essential to involve students in actions concerning alcohol abuse.

PREVALENCE OF LOW BACK PAIN AND BACK ERGONOMICS AWARENESS AMONG TEACHERS OF SELECTED SECONDARY SCHOOLS IN KANO METROPOLIS

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Farida Garba Sumaila

2015-12-01

Full Text Available Background: Low back pain (LBP is regarded as the commonest musculoskeletal problem in the world which affects people across various strata of the society from lay men on the street to teachers as well as health care providers in health institutions. Therefore the purpose of this study is to determine the prevalence of low back pain and back education awareness among secondary school teachers in Kano Metropolis. Methodos: 200 questionnaires were distributed and only 157 were retrieved, one out of which 4 were invalid because of incomplete data so that only 153 were relevant and used for analysis giving a return rate of 76.5%. The study revealed that 96 out of 153 respondents have low back pain implying 62.7% prevalence. The level of back ergonomic awareness on the other hand was found to be moderate (43.1%. Results: Based on the outcomes of the study, it was concluded that there is a high prevalence of low back pain among secondary school teachers in Kano metropolis. However, the level of back ergonomic awareness is moderate. Conclusion: Therefore proper intervention to prevent exposure to LBP among school teachers should be enhanced and teachers should be well educated on the importance of ergonomic intervention in their working environments.

Status Of Strategic Management Practices Of Secondary School ...

African Journals Online (AJOL)

The purpose of the study was to determine the extent to which principals practice strategic management skills in students' administration in secondary schools in Anambra State. All the two hundred and fifty-nine (259) secondary school principals of the six education zones of Anambra State were used for the study.

Pre-Service Secondary Teachers' Attitudes towards Inclusive Education

Science.gov (United States)

Costello, Shane; Boyle, Christopher

2013-01-01

The attitudes held by pre-service teachers have been shown to affect their willingness and ability to implement an inclusive approach to education. A sample consisting of 193 pre-service secondary teachers enrolled in secondary education courses at an Australian university were surveyed to determine their attitudes towards inclusive education,…

Building Vision/Goals and Excellence in the Management of Personnel by Secondary School Principals

OpenAIRE

Cecilia Emuji Ereh; James Ekpenyog Okon; Esther S. Uko; Aloysius Okon Umosen

2012-01-01

This study examined the relationship between transformational leadership practices of building school vision/goals and Excellence in the personnel management by secondary school principals in Cross River State. The study adopted the correlation survey design. A research question and null hypothesis guided the study, with a population of 5614 respondents, Cluster random sampling technique was used to randomly select 375 out of 5382 teachers from 46 selected public secondary schools from the th...

Professional determination problems of modern senior pupils

Directory of Open Access Journals (Sweden)

G.N. Danylenko

2017-03-01

Full Text Available Background. Today, young people are more focused on getting education as such, without taking into account the profession. The relevance of this study is the identification of the level of professional self-determination of senior pupils, the mechanisms of formation of professional preferences. The article contains the concept and content of professional self-determination in adolescence; the results of the study on the formation of professional self-determination in senior pupils are presented. The study conducted among 9th grade pupils of secondary schools has revealed that the further gradual self-determination of the future specialty depends not only on psychological readiness for conscious choice. Materials and methods. The study involved 982 pupils of secondary schools in Ukraine. To study the level of formation of professional readiness, there was conducted a survey on the developed questionnaire. Statistical analysis was carried out using MS Excel and SPSS 17. Results. The results showed that professional intents of 9-graders are a key feature for solving the problem of high school selection and future careers. But for most students, these intentions are contradictory due to objective reasons. Radio, television, books don’t have a significant impact on the choice of professional self-determination. Conclusions. The conducted survey is self-sufficient for the analysis of professional orientation. But the choice of profession by the students is influenced by many factors. Therefore, carrying out the studies on vocational guidance requires an integrated approach.

Correlating continuous assessment scores to junior secondary ...

African Journals Online (AJOL)

This study investigated the relationship between continuous assessment scores and junior secondary school certificate examination(JSCE) final scores in Imo State. A sample of four hundred students were purposively selected from thirty eight thousand students who took the 1997 JSCE in Imo State. The data used were ...

A Study of Occupational Stress and Organizational Climate of Higher Secondary Teachers

Science.gov (United States)

Benedicta, A. Sneha

2014-01-01

This study mainly aims to describe the occupational stress and organizational climate of higher secondary teachers with regard to gender, locality, family type, experience and type of management. Simple random sampling technique was adopted for the selection of sample. The data is collected from 200 higher secondary teachers from government and…

Hemi-ordered nanoporous carbon electrode material for highly selective determination of nitrite in physiological and environmental systems

Energy Technology Data Exchange (ETDEWEB)

Zhou, Shenghai; Wu, Hongmin; Wu, Ying; Shi, Hongyan; Feng, Xun; Jiang, Shang; Chen, Jian; Song, Wenbo, E-mail: wbsong@jlu.edu.cn

2014-08-01

Hemi-ordered nanoporous carbon (HONC) was obtained from a mesoporous silica template through a nano-replication method using furfuryl alcohol as the carbon source. The structure and morphology of HONC were characterized and analyzed in detail by X-ray diffraction, N{sub 2}-sorption, Raman spectroscopy and transmission electron microscopy. HONC was then demonstrated as active electrode material for selective determination of nitrite in either physiological or environmental system. Well separated oxidation peaks of ascorbic acid, dopamine, uric acid and nitrite were observed in physiological system, and simultaneous discrimination of catechol, hydroquinone, resorcinol and nitrite in environmental system was also accomplished. Distinctly improved performances for selective determination of nitrite (such as significantly fast and sensitive current response with especially high selectivity) coexisted with ascorbic acid, dopamine and uric acid in the physiological system, as well as with catechol, hydroquinone and resorcinol in the environmental system were achieved at HONC electrode material. The excellent discriminating ability and high selectivity for NO{sub 2}{sup −} determination were ascribed to the good electronic conductivity, unique hemi-ordered porous structure, large surface area and large number of edge plane defect sites contained on the surface of nanopore walls of HONC. Results in this work demonstrated that HONC is one of the promising catalytic electrode materials for nitrite sensor fabrication. - Highlights: • Hemi-ordered nanoporous carbon as an active electrode material • Good discriminating ability towards NO{sub 2}{sup −} from physiological or environmental system • Highly selective determination of nitrite with fast and sensitive current response.

Retroviral DNA integration: viral and cellular determinants of target-site selection.

Directory of Open Access Journals (Sweden)

Mary K Lewinski

2006-06-01

Full Text Available Retroviruses differ in their preferences for sites for viral DNA integration in the chromosomes of infected cells. Human immunodeficiency virus (HIV integrates preferentially within active transcription units, whereas murine leukemia virus (MLV integrates preferentially near transcription start sites and CpG islands. We investigated the viral determinants of integration-site selection using HIV chimeras with MLV genes substituted for their HIV counterparts. We found that transferring the MLV integrase (IN coding region into HIV (to make HIVmIN caused the hybrid to integrate with a specificity close to that of MLV. Addition of MLV gag (to make HIVmGagmIN further increased the similarity of target-site selection to that of MLV. A chimeric virus with MLV Gag only (HIVmGag displayed targeting preferences different from that of both HIV and MLV, further implicating Gag proteins in targeting as well as IN. We also report a genome-wide analysis indicating that MLV, but not HIV, favors integration near DNase I-hypersensitive sites (i.e., +/- 1 kb, and that HIVmIN and HIVmGagmIN also favored integration near these features. These findings reveal that IN is the principal viral determinant of integration specificity; they also reveal a new role for Gag-derived proteins, and strengthen models for integration targeting based on tethering of viral IN proteins to host proteins.

Receive antenna selection for underlay cognitive radio with instantaneous interference constraint

KAUST Repository

Hanif, Muhammad Fainan

2015-06-01

Receive antenna selection is a low complexity scheme to reap diversity benefits.We analyze the performance of a receive antenna selection scheme in spectrum sharing systems where the antenna that results in highest signal-to-interference plus noise ratio at the secondary receiver is selected to improve the performance of secondary transmission. Exact and asymptotic behaviours of the received SINR are derived for both general and interference limited scenarios over general fading environment. These results are then applied to the outage and average bit error rate analysis when the secondary transmitter changes the transmit power in finite discrete levels to satisfy the instantaneous interference constraint at the primary receiver.

[Surgical treatment of secondary peritonitis: A continuing problem. German version].

Science.gov (United States)

van Ruler, O; Boermeester, M A

2016-01-01

Secondary peritonitis remains associated with high mortality and morbidity rates. Treatment of secondary peritonitis is still challenging even in the era of modern medicine. Surgical intervention for source control remains the cornerstone of treatment besides adequate antimicrobial therapy and when necessary intensive medical care measures and resuscitation. A randomized clinical trial showed that relaparotomy on demand (ROD) after initial emergency surgery was the preferred treatment strategy, irrespective of the severity and extent of peritonitis. The effective and safe use of ROD requires intensive monitoring of the patient in a setting where diagnostic tests and decision making about relaparotomy are guaranteed round the clock. The lack of knowledge on timely and adequate patient selection, together with the lack of use of easy but reliable monitoring tools seem to hamper full implementation of ROD. The accuracy of the relaparotomy decision tool is reasonable for prediction of the formation of peritonitis and necessary selection of patients for computed tomography (CT). The value of CT in the early postoperative phase is unclear. Future research and innovative technologies should focus on the additive value of CT after surgical treatment for secondary peritonitis and on the further optimization of bedside prediction tools to enhance adequate patient selection for interventions in a multidisciplinary setting.

Teachers'Skills in Identification and Management of Students'Talents in Ondo State Secondary Schools

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M. A. Yusuf

2016-12-01

Full Text Available The study examined the teachers' skills in identification and management of secondary school students' talent in Ondo State. The study adopted a descriptive survey research design for the study. The population of the study com-prised 3462 secondary schools' teachers in Ondo Central Senatorial District while the sample consisted of 360 teachers. Multi-stage sampling technique was used to select the sample. The first stage was a simple random technique to select three Local Government Areas from six Local Government Areas in the District. Proportionate sampling technique was used to select 24 secondary schools from the three Local Government Areas selected. The last stage in-volved using proportionate stratified random sampling to select a total of 360 teachers. Data for the study were collected using questionnaire tagged Teachers Shills in Identifying Students' Talents Questionnaire (TSITQ.Data collected were analysed using frequency count and simple percentages. The results showed that the predominant skill used by teachers in identifying students' talents were Guidance and Counselling, Motivation, Creative teaching and Pedagogical. It was found out that motivational strategy (in form of gifts, prizes and scholarship was predominantly used by teachers in managing students' talents followed by independent study, creative teaching and pro-gramme planning. Based on the findings of the study it was therefore recommended that teachers should improve on their strategies such as independent study, creative teaching, individualised instructions and programme planning in managing secondary school students' talents.

Simultaneous determination of secondary metabolites from Vinca rosea plant extractives by reverse phase high performance liquid chromatography

Science.gov (United States)

Siddiqui, Mohammad Jamshed Ahmad; Ismail, Zhari; Saidan, Noor Hafizoh

2011-01-01

Background: Vinca rosea (Apocynaceae) is one of the most important and high value medicinal plants known for its anticancer alkaloids. It is the iota of the isolated secondary metabolites used in chemotherapy to treat diverse cancers. Several high performance liquid chromatography (HPLC) methods have been developed to quantify the active alkaloids in the plant. However, this method may serve the purpose in quantification of V. rosea plant extracts in totality. Objective: To develop and validate the reverse phase (RP)-HPLC method for simultaneous determination of secondary metabolites, namely alkaloids from V. rosea plant extracts. Materials and Methods: The quantitative determination was conducted by RP-HPLC equipped with ultraviolet detector. Optimal separation was achieved by isocratic elution with mobile phase consisting of methanol:acetonitrile:ammonium acetate buffer (25 mM) with 0.1% triethylamine (15:45:40 v/v) on a column (Zorbax Eclipse plus C18, 250 mm % 4.6 mm; 5 μm). The standard markers (vindoline, vincristine, catharanthine, and vinblastine) were identified by retention time and co-injected with reference standard and quantified by external standard method at 297 nm. Results: The precision of the method was confirmed by the relative standard deviation (R.S.D.), which was lower than 2.68%. The recoveries were in the range of 98.09%-108%. The limits of detection (LOD) for each marker alkaloids were lower than 0.20 μg. Different parts of the V. rosea extracts shows different concentrations of markers, flower samples were high in vinblastine content, while methanol extract from the leaves contains all the four alkaloids in good yield, and there is no significant presence of markers in water extracts. Conclusion: HPLC method established is appropriate for the standardization and quality assurance of V. rosea plant extracts. PMID:21716929

Determination of uranyl ion by potentiometric titration using an uranyl-selective electrode

International Nuclear Information System (INIS)

Nassory, N.S.

1990-01-01

A potentiometric titration of uranyl ion is described using an uranyl selective electrode based on a membrane containing a complex of UO 2 -bis[di-4-(1,1,3,3-tetramethylbutyl)phenyl phosphate] as an ion-exchanger and tritolyl phosphate as a solvent mediator. The titrations were carried out with various titrants: Sodium hydroxide, potassium fluoride and sodium salts of acetate, oxalate and citrate. The equivalence points were determined by Gran's method. Good results were obtained by using sodium oxalate as a titrant for the determination of uranium in several samples of ammonium diuranate. The results were quite comparable with those obtained by X-ray fluorescence spectrometry. (orig.)

Nuclear Power Plants Secondary Circuit Piping Wall-Thinning Management in China

International Nuclear Information System (INIS)

Zhong Zhimin; Li Jinsong; Zheng Hui

2012-01-01

Research and field feedbacks showed that nuclear power plants secondary circuit steam and water piping are more sensitive than that of fuel plant to the attack of flow-accelerated corrosion (FAC). FAC, Liquid droplet impingement or cavitation erosion will cause secondary circuit piping local wall-thinning in NPPs. Without effective management, the wall-thinning in those high energy piping will cause leakage or pipe rupture during nuclear power plant operation, more seriously cause unplanned shut down, injured and fatality, or heavy economic losses. This paper briefly introduces the history, development and state of the art of secondary circuit piping wall-thinning management in China NPPs. Then, the effectiveness of inspection grid size selecting was analyzed in detail based on field feedbacks. EPRI recommendatory inspection grid, JSME code recommendatory grid and plant specific inspection grid were compared and the detection probabilities of local wall-thinning were estimated. Then, the development and application of NPPs Secondary Circuit Piping Wall Thickness Management Information System, developed, operated and maintained by our team, was briefly introduced and the statistical analysis results of 11 PWR units were shared. It was conclude that the long term, systemic, effective wall-thinning management strategy of high energy piping was very important to the safety and economic operation of NPPs. Furthermore, take into account the actual situation of China nuclear power plants, some advice and suggestion on developing effective nuclear power plant secondary circuit steam and water piping wall-thinning management system are put forward from code development, design and manufacture, operation management, pipeline and locations selection, inspection method selection and application, thickness measurement result evaluation, residual life predication and decision making, feedbacks usage, personnel training and etc. (author)

Structural determinants and mechanism of HIV-1 genome packaging.

Science.gov (United States)

Lu, Kun; Heng, Xiao; Summers, Michael F

2011-07-22

Like all retroviruses, the human immunodeficiency virus selectively packages two copies of its unspliced RNA genome, both of which are utilized for strand-transfer-mediated recombination during reverse transcription-a process that enables rapid evolution under environmental and chemotherapeutic pressures. The viral RNA appears to be selected for packaging as a dimer, and there is evidence that dimerization and packaging are mechanistically coupled. Both processes are mediated by interactions between the nucleocapsid domains of a small number of assembling viral Gag polyproteins and RNA elements within the 5'-untranslated region of the genome. A number of secondary structures have been predicted for regions of the genome that are responsible for packaging, and high-resolution structures have been determined for a few small RNA fragments and protein-RNA complexes. However, major questions regarding the RNA structures (and potentially the structural changes) that are responsible for dimeric genome selection remain unanswered. Here, we review efforts that have been made to identify the molecular determinants and mechanism of human immunodeficiency virus type 1 genome packaging. Copyright © 2011 Elsevier Ltd. All rights reserved.

Flash Points of Secondary Alcohol and n-Alkane Mixtures.

Science.gov (United States)

Esina, Zoya N; Miroshnikov, Alexander M; Korchuganova, Margarita R

2015-11-19

The flash point is one of the most important characteristics used to assess the ignition hazard of mixtures of flammable liquids. To determine the flash points of mixtures of secondary alcohols with n-alkanes, it is necessary to calculate the activity coefficients. In this paper, we use a model that allows us to obtain enthalpy of fusion and enthalpy of vaporization data of the pure components to calculate the liquid-solid equilibrium (LSE) and vapor-liquid equilibrium (VLE). Enthalpy of fusion and enthalpy of vaporization data of secondary alcohols in the literature are limited; thus, the prediction of these characteristics was performed using the method of thermodynamic similarity. Additionally, the empirical models provided the critical temperatures and boiling temperatures of the secondary alcohols. The modeled melting enthalpy and enthalpy of vaporization as well as the calculated LSE and VLE flash points were determined for the secondary alcohol and n-alkane mixtures.

Service Time Analysis for Secondary Packet Transmission with Adaptive Modulation

KAUST Repository

Wang, Wen-Jing; Usman, Muneer; Yang, Hong-Chuan; Alouini, Mohamed-Slim

2017-01-01

Cognitive radio communications can opportunistically access underutilized spectrum for emerging wireless applications. With interweave cognitive implementation, secondary user transmits only if primary user does not occupy the channel and waits for transmission otherwise. Therefore, secondary packet transmission involves both transmission time and waiting time. The resulting extended delivery time (EDT) is critical to the throughput analysis of secondary system. In this paper, we study the EDT of secondary packet transmission with adaptive modulation under interweave implementation to facilitate the delay and throughput analysis of such cognitive radio system. In particular, we propose an analytical framework to derive the probability density functions of EDT considering random-length transmission and waiting slots. We also present selected numerical results to illustrate the mathematical formulations and to verify our analytical approach.

Service Time Analysis for Secondary Packet Transmission with Adaptive Modulation

KAUST Repository

Wang, Wen-Jing

2017-05-12

Cognitive radio communications can opportunistically access underutilized spectrum for emerging wireless applications. With interweave cognitive implementation, secondary user transmits only if primary user does not occupy the channel and waits for transmission otherwise. Therefore, secondary packet transmission involves both transmission time and waiting time. The resulting extended delivery time (EDT) is critical to the throughput analysis of secondary system. In this paper, we study the EDT of secondary packet transmission with adaptive modulation under interweave implementation to facilitate the delay and throughput analysis of such cognitive radio system. In particular, we propose an analytical framework to derive the probability density functions of EDT considering random-length transmission and waiting slots. We also present selected numerical results to illustrate the mathematical formulations and to verify our analytical approach.

Direct amination of secondary alcohols using Ammonia

NARCIS (Netherlands)

Pingen, D.L.L.; Müller, C.; Vogt, D.

2010-01-01

Hydrogen shuttle: For the first time secondary alcohols and ammonia can be directly converted into primary amines with a selectivity of up to 99¿% by using a simple ruthenium/phosphine catalyst (see scheme; R1, R2= alkyl, aryl, alkenyl; M=[Ru3(CO)12]; and L=phosphine ligand).

P ersonal Attributes as Determinants of Sport Participation among Undergraduates in Selected Nigerian Universities

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Yomi AWOSIKA

2014-03-01

Full Text Available This study focuses on personal attributes of undergraduates as determinants of sport participation in selected Nigerian universities which include age, gender and marital status. The instrument for the study is a self - developed, validated questionnaire. The subjects of the study are undergraduates in selected Nigerian universities. Analysis is the use of percentages and inferential statistics of chi square X 2 at 0.05 level of significance. The results derived from the study reveal that students’ personal attributes significantly determine their sport participation. Among other recommendations made is that it is highly imperative for university authorities to make frantic efforts to develop modalities capable of enco uraging students’ sport participation since most of them have sport potentials as evident in their post - primary school sport records. This will enable our universities groom healthy and academically sound graduates.

SIMS of Organic Materials—Interface Location in Argon Gas Cluster Depth Profiles Using Negative Secondary Ions

Science.gov (United States)

Havelund, R.; Seah, M. P.; Tiddia, M.; Gilmore, I. S.

2018-02-01

A procedure has been established to define the interface position in depth profiles accurately when using secondary ion mass spectrometry and the negative secondary ions. The interface position varies strongly with the extent of the matrix effect and so depends on the secondary ion measured. Intensity profiles have been measured at both fluorenylmethyloxycarbonyl-uc(l)-pentafluorophenylalanine (FMOC) to Irganox 1010 and Irganox 1010 to FMOC interfaces for many secondary ions. These profiles show separations of the two interfaces that vary over some 10 nm depending on the secondary ion selected. The shapes of these profiles are strongly governed by matrix effects, slightly weakened by a long wavelength roughening. The matrix effects are separately measured using homogeneous, known mixtures of these two materials. Removal of the matrix and roughening effects give consistent compositional profiles for all ions that are described by an integrated exponentially modified Gaussian (EMG) profile. Use of a simple integrated Gaussian may lead to significant errors. The average interface positions in the compositional profiles are determined to standard uncertainties of 0.19 and 0.14 nm, respectively, using the integrated EMG function. Alternatively, and more simply, it is shown that interface positions and profiles may be deduced from data for several secondary ions with measured matrix factors by simply extrapolating the result to Ξ = 0. Care must be taken in quoting interface resolutions since those measured for predominantly Gaussian interfaces with Ξ above or below zero, without correction, appear significantly better than the true resolution.

Determination of lithium in organic matrix by potentiometric titration using fluoride ion selective electrode

International Nuclear Information System (INIS)

Govindan, R.; Alamelu, D.; Shah, Raju; Aggarwal, S.K.

2008-01-01

A method has been developed for the determination of lithium (Li) present in organic matrix containing hexa methylene tetramine (HMTA) and urea used in the sol-gel process for preparing lithium titanate microspheres, using fluoride ion selective electrode and potentiometric end point. Lithium is present in the wash solutions of the Sol-Gel process employed for the preparation of lithium titanate microspheres, proposed to be used in TBM (Test Blanket Module) of International Thermonuclear Experimental Reactor (ITER) project. Methods such as ICP-AES, AAS etc. used in aqueous solutions cannot be employed directly for lithium determination in organic matrix containing hexa methylene tetramine (HMTA), urea, NH 4 NO 3 , NH 4 Cl etc. A potentiometric method using a combination fluoride ion selective electrode for end point detection was developed and has been employed for lithium determination in the process streams from sol-gel process. The method is simple and rapid and an accuracy of about 0.5 % was achieved for the determination of Li in the range of 1 to 20 mg. The method is based on the complexation of Li by adding a known excess of NH 4 F solution, followed by potentiometric end point detection using fluoride ISE

CSI 3.0: a web server for identifying secondary and super-secondary structure in proteins using NMR chemical shifts.

Science.gov (United States)

Hafsa, Noor E; Arndt, David; Wishart, David S

2015-07-01

The Chemical Shift Index or CSI 3.0 (http://csi3.wishartlab.com) is a web server designed to accurately identify the location of secondary and super-secondary structures in protein chains using only nuclear magnetic resonance (NMR) backbone chemical shifts and their corresponding protein sequence data. Unlike earlier versions of CSI, which only identified three types of secondary structure (helix, β-strand and coil), CSI 3.0 now identifies total of 11 types of secondary and super-secondary structures, including helices, β-strands, coil regions, five common β-turns (type I, II, I', II' and VIII), β hairpins as well as interior and edge β-strands. CSI 3.0 accepts experimental NMR chemical shift data in multiple formats (NMR Star 2.1, NMR Star 3.1 and SHIFTY) and generates colorful CSI plots (bar graphs) and secondary/super-secondary structure assignments. The output can be readily used as constraints for structure determination and refinement or the images may be used for presentations and publications. CSI 3.0 uses a pipeline of several well-tested, previously published programs to identify the secondary and super-secondary structures in protein chains. Comparisons with secondary and super-secondary structure assignments made via standard coordinate analysis programs such as DSSP, STRIDE and VADAR on high-resolution protein structures solved by X-ray and NMR show >90% agreement between those made with CSI 3.0. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Differential Secondary Reconstitution of In Vivo-Selected Human SCID-Repopulating Cells in NOD/SCID versus NOD/SCID/γ chainnull Mice

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Shanbao Cai

2011-01-01

Full Text Available Humanized bone-marrow xenograft models that can monitor the long-term impact of gene-therapy strategies will help facilitate evaluation of clinical utility. The ability of the murine bone-marrow microenvironment in NOD/SCID versus NOD/SCID/γ chainnull mice to support long-term engraftment of MGMTP140K-transduced human-hematopoietic cells following alkylator-mediated in vivo selection was investigated. Mice were transplanted with MGMTP140K-transduced CD34+ cells and transduced cells selected in vivo. At 4 months after transplantation, levels of human-cell engraftment, and MGMTP140K-transduced cells in the bone marrow of NOD/SCID versus NSG mice varied slightly in vehicle- and drug-treated mice. In secondary transplants, although equal numbers of MGMTP140K-transduced human cells were transplanted, engraftment was significantly higher in NOD/SCID/γ chainnull mice compared to NOD/SCID mice at 2 months after transplantation. These data indicate that reconstitution of NOD/SCID/γ chainnull mice with human-hematopoietic cells represents a more promising model in which to test for genotoxicity and efficacy of strategies that focus on manipulation of long-term repopulating cells of human origin.

A Study on Primary and Secondary School Students' Misconceptions about Greenhouse Effect (Erzurum Sampling)

Science.gov (United States)

Gul, Seyda; Yesilyurt, Selami

2011-01-01

The aim of this study is to determine what level of primary and secondary school students' misconceptions related to greenhouse effect is. Study group consists of totally 280 students attended to totally 8 primary and secondary schools (4 primary school, 4 secondary school) which were determined with convenient sampling method from center of…

Students' level of skillfulness and use of the internet in selected ...

African Journals Online (AJOL)

The study examined level of skillfulness and the use of the Internet for learning among secondary school students in Lagos State, Nigeria. The descriptive survey research method was adopted for the study. A sample of 450 students was randomly selected from the three secondary schools. One intact arm was selected from ...

Young Adult Literature in the Malaysian Secondary School

Science.gov (United States)

Govindarajoo, Mallika V.; Mukundan, Jayakaran

2013-01-01

This article presents the results of a study on the experience of the Malaysian secondary school student with Young Adult Literature in the English language classroom. The study aimed to determine the extent to which the Malaysian secondary school student identified with the young adult protagonists and issues in the novels which have been…

Resection for secondary malignancy of the pancreas.

Science.gov (United States)

Hung, Jui-Hsia; Wang, Shin-E; Shyr, Yi-Ming; Su, Cheng-Hsi; Chen, Tien-Hua; Wu, Chew-Wun

2012-01-01

This study tried to clarify the role of pancreatic resection in the treatment of secondary malignancy with metastasis or local invasion to the pancreas in terms of surgical risk and survival benefit. Data of secondary malignancy of the pancreas from our 19 patients and cases reported in the English literature were pooled together for analysis. There were 329 cases of resected secondary malignancy of the pancreas, including 241 cases of metastasis and 88 cases of local invasion. The most common primary tumor metastatic to the pancreas and amenable to resection was renal cell carcinoma (RCC) (73.9%). More than half (52.3%) of the primary cancers with local invasion to the pancreas were colon cancer, and nearly half (40.9%) were stomach cancer. The median metastatic interval was 84 months (7 years) for overall primary tumors and 108 months (9 years) for RCC. The 5-year survival for secondary malignancy of the pancreas after resection was 61.1% for metastasis and 58.9% for local invasion, with 72.8% for RCC metastasis, 69.0% for colon cancer, and 43.8% for stomach cancer with local invasion to the pancreas. Pancreatic resection should not be precluded for secondary malignancy of the pancreas because long-term survival could be achieved with acceptable surgical risk in selected patients.

Agricultural Education in Secondary Schools in Tanzania: Were the ...

African Journals Online (AJOL)

This study aims to assess whether the objectives of introducing agricultural education in secondary schools were realised. The whereabouts of graduates from agriculture biased schools was traced to establish their activities and determine their attitude towards the significance of secondary agricultural education in ...

Selective modes determine evolutionary rates, gene compactness and expression patterns in Brassica.

Science.gov (United States)

Guo, Yue; Liu, Jing; Zhang, Jiefu; Liu, Shengyi; Du, Jianchang

2017-07-01

It has been well documented that most nuclear protein-coding genes in organisms can be classified into two categories: positively selected genes (PSGs) and negatively selected genes (NSGs). The characteristics and evolutionary fates of different types of genes, however, have been poorly understood. In this study, the rates of nonsynonymous substitution (K a ) and the rates of synonymous substitution (K s ) were investigated by comparing the orthologs between the two sequenced Brassica species, Brassica rapa and Brassica oleracea, and the evolutionary rates, gene structures, expression patterns, and codon bias were compared between PSGs and NSGs. The resulting data show that PSGs have higher protein evolutionary rates, lower synonymous substitution rates, shorter gene length, fewer exons, higher functional specificity, lower expression level, higher tissue-specific expression and stronger codon bias than NSGs. Although the quantities and values are different, the relative features of PSGs and NSGs have been largely verified in the model species Arabidopsis. These data suggest that PSGs and NSGs differ not only under selective pressure (K a /K s ), but also in their evolutionary, structural and functional properties, indicating that selective modes may serve as a determinant factor for measuring evolutionary rates, gene compactness and expression patterns in Brassica. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

Secondary effects of radiotherapy on the orofacial sphere

International Nuclear Information System (INIS)

Guillaume, Nicolas

2012-01-01

The objective of this research is to determine the role of the dental surgeon in the taking into care of patients treated by head and neck radiotherapy. It also aims at giving information to the patient on secondary effects which radiotherapy may induce, and at determining which therapeutic behaviour to adopt to prevent or at least mitigate the appearance of complications. The author first presents some generalities on radiotherapy: presentation of upper aero-digestive tract cancers (surgery, radiotherapy, and chemotherapy), description of the different radiotherapy techniques (external radiotherapy, brachytherapy), discussion of factors influencing local secondary effects of radiotherapy. The second part addresses the specific case of early orofacial secondary effects, discusses their origin, clinic signs and prevention means: cutaneous effect, mucositis, xerostomia, candidiasis, taste disorders, relationship between early local reactions and anti-tumour treatment efficiency. The third part addresses late orofacial secondary effects: cervix sclerosis, limitation of mouth opening, dental effects, periodontal diseases, osteoradionecrosis. The last part discusses the evolution of radiotherapy: intensity modulated conformational radiotherapy, targeted therapeutics [fr

Identifying and sharing data for secondary data analysis of physical activity, sedentary behaviour and their determinants across the life course in Europe : general principles and an example from DEDIPAC

NARCIS (Netherlands)

Lakerveld, J.; Loyen, A.; Ling, F.C.M.; De Craemer, M.; van der Ploeg, H.P.; O’Gorman, D.J.; Carlin, A.; Caprinica, L.; Kalter, J.; Oppert, J.-M.; Chastin, S.; Cardon, G.; Brug, J.; MacDonncha, C.

2017-01-01

Background The utilisation of available cross-European data for secondary data analyses on physical activity, sedentary behaviours and their underlying determinants may benefit from the wide variation that exists across Europe in terms of these behaviours and their determinants. Such reuse of

Fluorimetric determination of copper(II) in aqueous solution using lucifer yellow CH as selective metal reagent

Energy Technology Data Exchange (ETDEWEB)

Mayr, T.; Wencel, D.; Werner, T. [Univ. of Regensburg (Germany) Inst. of Analytical Chemistry, Chemo- and Biosensors

2001-09-01

Lucifer yellow CH is shown to be a highly selective fluorescent reagent for the determination of Cu(II) in the {mu}g L{sup -1} concentration range. The fluorophore is statically quenched by Cu(II); the carbohydrazide group was assigned as the complexing part of the dye molecule. A total range of Cu(II) determination from 0.06 mg L{sup -1} (1 {mu}mol L{sup -1}) to 6.3 mg L{sup -1} (100 {mu}mol L{sup -1}) with a limit of detection of 0.019 mg L{sup -1} (0.3 {mu}mol L{sup -1}) was obtained, along with surprisingly high selectivity. There was no interference from alkaline and earth alkaline metal ions. The cross sensitivity to heavy metal ions was evaluated by the separate solution method and by competitive binding experiments. Calibration plots are shown for Cu(II) determination at different pH and the dissociation constant was determined. The application of the reagent was demonstrated by the determination of the Cu(II) content of tap water samples. (orig.)

How teaching practices are connected to student intention to enrol in upper secondary school physics courses

Science.gov (United States)

Juuti, Kalle; Lavonen, Jari

2016-05-01

Background: In developed countries, it is challenging for teachers to select pedagogical practices that encourage students to enrol in science and technology courses in upper secondary school. Purpose: Aiming to understand the enrolment dynamics, this study analyses sample-based data from Finland's National Assessment in Science to determine whether pedagogical approaches influence student intention to enrol in upper secondary school physics courses. Sample: This study examined a clustered sample of 2949 Finnish students in the final year of comprehensive school (15-16 years old). Methods: Through explorative factor analysis, we extracted several variables that were expected to influence student intention to enrol in physics courses. We applied partial correlation to determine the underlying interdependencies of the variables. Results: The analysis revealed that the main predictor of enrolment in upper secondary school physics courses is whether students feel that physics is important. Although statistically significant, partial correlations between variables were rather small. However, the analysis of partial correlations revealed that pedagogical practices influence inquiry and attitudinal factors. Pedagogical practices that emphasise science experimentation and the social construction of knowledge had the strongest influence. Conclusions: The research implies that to increase student enrolment in physics courses, the way students interpret the subject's importance needs to be addressed, which can be done by the pedagogical practices of discussion, teacher demonstrations, and practical work.

Private sector participation in secondary education in Nigeria: Implications for national development

Directory of Open Access Journals (Sweden)

Uyi Kizito Ehigiamusoe

2012-12-01

Full Text Available The study examines private sector participation in secondary education in Nigeria and its implications for national development. The population consisted all the providers and recipients of private secondary education in the Federal Capital Territory (FCT. Simple random sampling was used to select 200 providers and recipients of private secondary education across the six Area Councils in the FCT. An instrument designated Private Sector Participation in Secondary Education (PSPSE was used to collect data. The data were analysed using Chi-Square method to test for the acceptance or rejection of the study hypotheses. The findings revealed that the academic performance of students in private secondary schools is better than the academic performance of students in public secondary schools. The study further revealed that private secondary schools have better infrastructure than public secondary schools in Nigeria, but private secondary schools contribute less to the development of human resources than public schools in Nigeria. Recommendations are proffered to make private secondary education more viable and responsive to the needs of the society.

Impact of Primary User Traffic on Adaptive Transmission for Cognitive Radio with Partial Relay Selection

KAUST Repository

Rao, Anlei

2012-09-08

In a cognitive relay system, the secondary user is permitted to transmit data via a relay when licensed frequency bands are detected to be free. Previous studies mainly focus on reducing or limiting the interference of the secondary transmission on the primary users. On the other hand, however, the primary user traffic will also affect the data transmission performance of the secondary users. In this paper, we investigate the impact of the primary user traffic on the bit error rate (BER) of the secondary transmission, when the secondary user adopts adaptive transmission with a relay partially selected. From the numerical results, we can see that the primary user traffic seriously degrades average BER. The worse-link partial selection can perform almost as well as the global selection when the channel conditions of the source-relay links and the relay-destination links differ a lot. In addition, although the relay selection improves the spectral efficiency of the secondary transmission, numerical results show that it only has slight impact on the overall average BER, so that the robustness of the system will not be affected by the relay selection.

Selective and specific inhibition of the plasmodium falciparum lysyl-tRNA synthetase by the fungal secondary metabolite cladosporin.

Science.gov (United States)

Hoepfner, Dominic; McNamara, Case W; Lim, Chek Shik; Studer, Christian; Riedl, Ralph; Aust, Thomas; McCormack, Susan L; Plouffe, David M; Meister, Stephan; Schuierer, Sven; Plikat, Uwe; Hartmann, Nicole; Staedtler, Frank; Cotesta, Simona; Schmitt, Esther K; Petersen, Frank; Supek, Frantisek; Glynne, Richard J; Tallarico, John A; Porter, Jeffrey A; Fishman, Mark C; Bodenreider, Christophe; Diagana, Thierry T; Movva, N Rao; Winzeler, Elizabeth A

2012-06-14

With renewed calls for malaria eradication, next-generation antimalarials need be active against drug-resistant parasites and efficacious against both liver- and blood-stage infections. We screened a natural product library to identify inhibitors of Plasmodium falciparum blood- and liver-stage proliferation. Cladosporin, a fungal secondary metabolite whose target and mechanism of action are not known for any species, was identified as having potent, nanomolar, antiparasitic activity against both blood and liver stages. Using postgenomic methods, including a yeast deletion strains collection, we show that cladosporin specifically inhibits protein synthesis by directly targeting P. falciparum cytosolic lysyl-tRNA synthetase. Further, cladosporin is >100-fold more potent against parasite lysyl-tRNA synthetase relative to the human enzyme, which is conferred by the identity of two amino acids within the enzyme active site. Our data indicate that lysyl-tRNA synthetase is an attractive, druggable, antimalarial target that can be selectively inhibited. Copyright © 2012 Elsevier Inc. All rights reserved.

Selective masking and demasking for the stepwise complexometric determination of aluminium, lead and zinc from the same solution

Directory of Open Access Journals (Sweden)

Singh Nahar

2008-03-01

Full Text Available Abstract Background A complexometric method based on selective masking and de-masking has been developed for the rapid determination of aluminium, lead and zinc from the same solution in glass and glass frit samples. The determination is carried out using potassium cyanide to mask zinc, and excess disodium salt of EDTA to mask lead and aluminium. The excess EDTA was titrated with standard Mn(IISO4 solution using Erichrome Black-T as the indicator. Subsequently selective de-masking agents – triethanolamine, 2,3-dimercaptopropanol and a formaldehyde/acetone mixture – were used to determine quantities of aluminium, lead and zinc in a stepwise and selective manner. Results The accuracy of the method was established by analysing glass certified reference material NBS 1412. The standard deviation of the measurements, calculated by analysing five replicates of each sample, was found to be less than 1.5% for the method proposed. Conclusion The novelty of the method lies in its simplicity and accuracy afforded by there not being a need for a prior separation or instrumentation. The proposed method was found to be highly selective for the precise determination of aluminum, zinc and lead in the routine analysis of glass batch and allied materials.

Selective changes in expression of HLA class I polymorphic determinants in human solid tumors

International Nuclear Information System (INIS)

Natali, P.G.; Nicotra, M.R.; Bigotti, A.; Venturo, I.; Giacomini, P.; Marcenaro, L.; Russo, C.

1989-01-01

Analysis of surgical biopsies with monoclonal antibodies (mAbs) to framework determinants of major histocompatibility complex class I antigens has shown that malignant transformation is frequently associated with a marked loss of these cell surface molecules. The present study sought to determine whether more selective losses of major histocompatibility complex class I expression occur. Multiple specimens from 13 different types of primary and metastatic tumors were tested utilizing mAb BB7.2, which recognizes a polymorphic HLA-A2 epitope. In each case, expression of HLA-A,B,C molecules was determined by testing with mAb W6/32 directed to a framework HLA class I determinant. The authors have found that in HLA-A2-positive patients, HLA-A2 products are not detectable or are reduced in their expression in 70-80% of endometrial, colorectal, mammary, and renal tumors; in 40-60% of soft-tissue, skin, ovary, urinary bladder, prostate, and stomach tumors; and in 25-30% of melanomas and lung carcinomas tested. All tumors expressed the framework HLA-A,B.C determinant. The HLA-A2 epitope recognized by mAb BB7.2 is located in a portion of the HLA-A2 molecule postulated to react with the T-cell receptor. The selective loss of an HLA class I polymorphic epitope shown in this study may explain the mechanism by which tumor cells escape both T-cell recognition and natural killer cell surveillance

Efficacy and safety of ultrasound-guided radiofrequency ablation of hyperplastic parathyroid gland for secondary hyperparathyroidism associated with chronic kidney disease.

Science.gov (United States)

Peng, Chengzhong; Zhang, Zhengxian; Liu, Jibin; Chen, Hongyu; Tu, Xiao; Hu, Rihong; Ni, Jun; Weng, Ning; Pang, Haisu; Xue, Zhengmei

2017-03-01

The purpose of this study was to determine if ultrasound-guided radiofrequency ablation (RFA) of hyperplastic parathyroid glands could be used to treat secondary hyperparathyroidism (HPT) in patients with chronic kidney disease. RFA of the hyperplastic parathyroid glands was performed in 34 patients with secondary HPT. Intact parathyroid hormone (iPTH), calcium, and phosphorus were measured. The outcome was based on the ablation extent (ie, 4, 3, and 1-2 glands). The iPTH, calcium, and phosphorus levels decreased in all groups after RFA. One year after ablation, these parameters remained significantly lower in the 4-gland ablation group compared with the 3-gland and 1 to 2-gland groups. The same tendency was observed for the symptom score. The iPTH levels of secondary HPT is feasible in selected patients. © 2016 Wiley Periodicals, Inc. Head Neck 39: 564-571, 2017. © 2016 Wiley Periodicals, Inc.

Using ion-selective electrode for determining iodine-131 preparation specific activity

International Nuclear Information System (INIS)

Melnik, M.I.; Nazirova, T.E.

2002-01-01

A pilot facility was developed in 2000 for the production of iodine-131. The parameters of the preparation are as follows: chemical form: sodium iodide solution (NaI-131) in a carbonate-bicarbonate buffer (or in 0.001M NaOH); specific activity: carrier free (> 5 Ci/mg); solution pH: 7-10; radionuclide purity: > 99.9%; radiochemical purity: > 97%; bulk activity: 0.15 Ci/ml. The experimental results of investigation aimed at the determination of the specific activity of the I-131 preparation using a iodine-selective electrode are described. The method enables the analytical concentration of iodide ions in the carbonate-bicarbonate buffer (pH = 8-11) and NaOH solution (0.01 mol/l, pH = 8-11) to be determined. A micro-cell has been developed for the analysis of the I-131 solution allowing the sample volume to be reduced to below 0.3 ml. The relative error of determination of the analytical concentration of iodide (10 -6 to 10 -1 mol/l) does not exceed 1%

Role of species diversity and secondary compound complementarity on diet selection of Mediterranean shrubs by goats.

Science.gov (United States)

Rogosic, Jozo; Estell, Richard E; Skobic, Dragan; Martinovic, Anita; Maric, Stanislava

2006-06-01

Goats foraging on Mediterranean shrubs containing secondary compounds (toxins) may consume a variety of shrubs that contain different phytotoxins, thereby increasing shrub intake and avoiding toxicosis. We conducted eight experiments to examine whether goats offered different mixtures of shrubs containing different phytotoxins (tannins and saponins) would consume more shrub biomass than goats offered one shrub a single phytotoxin (tannin or saponin). In the first three experiments, goats fed a mixture of three tannin-rich shrubs (Quercus ilex, Arbutus unedo, and Pistacia lentiscus) ate more foliage than goats offered only one shrub (23.2 vs. 10.7 g/kg BW; 25.2 vs. 13.4 g/kg BW, and 27.9 vs. 7.9 g/kg BW), regardless of tannin concentration in individual shrub species. Goats also consumed more foliage when offered the same three tannin-rich shrubs than when offered the saponin-rich shrub Hedera helix (25.4 vs. 8.0 g/kg BW). However, goats offered a mixture of the same three tannin-rich shrubs consumed less foliage than goats offered a mixture of two shrubs containing tannins and saponins: Quercus and Hedera (21.6 vs. 27.1 g/kg BW), Arbutus and Hedera (21.8 vs. 27.1 g/kg BW), and Pistacia and Hedera (19.7 vs. 22.0 g/kg BW). Comparison of intake of shrubs containing only tannins or saponins to intake of shrubs containing both tannins and saponins indicated that goats consumed more total biomass when fed with shrubs with both classes of compounds than with either tannins or saponins alone. Our results suggest that goats can increase intake of Mediterranean shrubs high in secondary compounds by selecting those with different classes of phytotoxins. Simultaneous ingestion of shrubs containing tannins and saponins may promote chemical interactions that inhibit toxic effects of these phytotoxins in the intestinal tract. In addition to complementary interactions between tannins and saponins, biological diversity within Mediterranean maquis vegetation also plays a positive

Oxidation of the Primary Alcoholic Moiety Selectively in the Presence of the Secondary Alcoholic Moieties

International Nuclear Information System (INIS)

Tin Myint Htwe

2011-12-01

Both primary and secondary alcoholic moieties are very sensitive to oxidation reactions. But sometimes it is necessary to oxidized only the primary alcoholic moiety. Such cases are usually found in Food Industries. In this situation, TEMPO (1, 1, 6, 6-Tetramethyl-1-Piperidine Oxoammonium) was used as an oxidizing agent. In this paper, Alpha starch was successfully oxidized using TEMPO as the oxidizing agent in combination with sodium hypochlorite with and without sodium bromide. The oxidation of primary alcoholic moiety only and the remaining untouched secondary alcoholic moiety were proved by infrared spectroscopy method.

The Prevalence and Predictors of Cigarette Smoking among Secondary School Students in Nigeria.

Science.gov (United States)

Odeyemi, K A; Osibogun, A; Akinsete, A O; Sadiq, L

2009-03-01

This study was carried out to determine the prevalence of smoking among secondary school students and identify factors that influence smoking amongst them. This descriptive and explorative study was conducted among 1,183 secondary school students, selected by multistage sampling from each of the 6 geopolitical zones in Nigeria. Data was collected by using interviewer administered structured questionnaires. This study recorded a lifetime smoking prevalence of 26.4% and current smoking prevalence of 17.1% among secondary school students in Nigeria. Most (82%) of the students had seen warnings against smoking and most of them were aware that it is possible for cigarette smoking to damage body organs. Unfortunately, however, seeing such warnings had no significant effect on their decision to smoke or not. The students who smoke were introduced to smoking mainly by their friends (67.4 %), and the television (13.4%). Smoking habits of the respondents were influenced by parents' educational status (psmoke (psmoked. Peer pressure was the main reason cited by respondents for initiating smoking. It is suggested that our smoking prevention programmes be reviewed and appropriate health education and smoking cessation programmes be developed and implemented in order to prevent and control smoking among Nigerian students.

Selective inhibition of distracting input.

Science.gov (United States)

Noonan, MaryAnn P; Crittenden, Ben M; Jensen, Ole; Stokes, Mark G

2017-10-16

We review a series of studies exploring distractor suppression. It is often assumed that preparatory distractor suppression is controlled via top-down mechanisms of attention akin to those that prepare brain areas for target enhancement. Here, we consider two alternative mechanisms: secondary inhibition and expectation suppression within a predictive coding framework. We draw on behavioural studies, evidence from neuroimaging and some animal studies. We conclude that there is very limited evidence for selective top-down control of preparatory inhibition. By contrast, we argue that distractor suppression often relies secondary inhibition of non-target items (relatively non-selective inhibition) and on statistical regularities of the environment, learned through direct experience. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Secondary Hypertension

Science.gov (United States)

Secondary hypertension Overview Secondary hypertension (secondary high blood pressure) is high blood pressure that's caused by another medical condition. Secondary hypertension can be caused by conditions that affect your kidneys, ...

Cutaneous mucormycosis secondary to penetrative trauma.

Science.gov (United States)

Zahoor, Bilal; Kent, Stephen; Wall, Daryl

2016-07-01

Mucormycosis is a rare but serious sequelae of penetrating trauma [1-5]. In spite of aggressive management, mortality remains high due to dissemination of infection. We completed a review of literature to determine the most optimal treatment of cutaneous mucormycosis which occurs secondary to penetrating trauma. We completed a review regarding the management of mucormycosis in trauma patients. We selected a total of 36 reports, of which 18 were case-based, for review. Surgical debridement is a primary predictor of improved outcomes in the treatment of mucormycosis [3,6,7]. Anti-fungal therapy, especially lipid soluble formulation of Amphotericin B, is helpful as an adjunct or when surgical debridement has been maximally achieved. Further research is needed to fully evaluate the impact of topical dressings; negative pressure wound therapy is helpful. An aggressive and early surgical approach, even at the expense of disfigurement, is necessary to reduce mortality in the setting of cutaneous mucormycosis that results from penetrating trauma [4,8,9]. Anti-fungal therapy and negative pressure wound therapy are formidable adjuncts. Copyright © 2016 Elsevier Ltd. All rights reserved.

Simulation and analysis of secondary emission microwave electron gun

International Nuclear Information System (INIS)

He Wencan; Pei Yuanji; Jin Kai; Wu Congfeng

2001-01-01

The development of high-current, short-duration pulses of electrons has been a challenging problem for many year. Micro-pulse-gun (MPG) is a novel concept that employs the resonant amplification of an electron current by secondary electron emission in a RE cavity. Using the computation code URMEL-T, several kinds of RF cavities under the frequency of 2856 MHz were calculated and optimized, the magnetic and electric field distribution in them were got. Through particle-in-cell (PIC) simulation, the self-bunching process in a MPG was proved, the relationship between the cavity length and selected phase and the relationship between the peak electric field and selected phase were got. With cathode material of high secondary emission coefficient, the MPG can produce high current densities (1132-5303 A/cm 2 ) and short pulses (3.15-10 ps)

Chemoselective organocatalytic aerobic oxidation of primary amines to secondary imines.

Science.gov (United States)

Wendlandt, Alison E; Stahl, Shannon S

2012-06-01

Biomimetic aerobic oxidation of primary benzylic amines has been achieved by using a quinone catalyst. Excellent selectivity is observed for primary, unbranched benzylic amines relative to secondary/tertiary amines, branched benzylic amines, and aliphatic amines. The exquisite selectivity for benzylic amines enables oxidative self-sorting within dynamic mixtures of amines and imines to afford high yields of cross-coupled imine products.

Qualities of effective secondary science teachers: Perspectives of university biology students

Science.gov (United States)

McCall, Madelon J.

This research was an attempt to hear the student voice concerning secondary science teacher effectiveness and to share that voice with those who impact the educational process. It was a snapshot of university freshmen biology students' opinions of the qualities of effective secondary science teachers based on their high school science experiences. The purpose of this study was to compile a list of effective secondary science teacher qualities as determined through a purposeful sampling of university second semester biology students and determine the role of the secondary science teacher in promoting interest and achievement in science, as well as the teacher's influence on a students' choice of a science career. The research was a mixed methods design using both quantitative and qualitative data obtained through the use of a 24 question electronic survey. There were 125 participants who provided information concerning their high school science teachers. Respondents provided information concerning the qualities of effective secondary science teachers and influences on the students' present career choice. The quantitative data was used to construct a hierarchy of qualities of effective secondary science teachers, divided into personal, professional, and classroom management qualities. The qualitative data was used to examine individual student responses to questions concerning secondary science teacher effectiveness and student career choice. The results of the research indicated that students highly value teachers who are both passionate about the subject taught and passionate about their students. High school science students prefer teachers who teach science in a way that is both interesting and relevant to the student. It was determined that the greatest influence on a secondary student's career choice came from family members and not from teachers. The secondary teacher's role was to recognize the student's interest in the career and provide encouragement

Interference-aware random beam selection for spectrum sharing systems

KAUST Repository

Abdallah, Mohamed M.; Sayed, Mostafa M.; Alouini, Mohamed-Slim; Qaraqe, Khalid A.

2012-01-01

. In this paper, we develop interference-aware random beam selection schemes that provide enhanced throughput for the secondary link under the condition that the interference observed at the primary link is within a predetermined acceptable value. For a secondary

Problem Solving Strategies of Selected Pre-Service Secondary School Mathematics Teachers in Malaysia

Science.gov (United States)

Yew, Wun Theam; Zamri, Sharifah Norul Akmar Syed

2016-01-01

Problem solving strategies of eight pre-service secondary school mathematics teachers (PSSMTs) were examined in this study. A case study research design was employed and clinical interview technique was used to collect the data. Materials collected for analysis consisted of audiotapes and videotapes of clinical interviews, subjects' notes and…

The Advantages of Single-Sex Catholic Secondary Schooling: Selection Effects, School Effects, or "Much Ado About Nothing?"

Science.gov (United States)

LePore, Paul C.; Warren, John Robert

Data from the National Education Longitudinal Study of 1988 (NELS:88) were used to investigate whether there are differences between single-sex and coeducational Catholic secondary school students in academic and social psychological outcomes, whether any differences especially favor young women in single-sex Catholic secondary schools, and…

Effects of Corporal Punishment on Disciplinary Control of Secondary ...

African Journals Online (AJOL)

Administration of corporal punishment in secondary schools tends to be cruel, inhuman and could result in child abuse. Therefore, the purpose of this study was to determine the effects of the use of corporal punishment on the disciplinary control of secondary education students in Calabar Metropolis of Nigeria. The study ...

Secondary Analysis of National Longitudinal Transition Study 2 Data

Science.gov (United States)

Hicks, Tyler A.; Knollman, Greg A.

2015-01-01

This review examines published secondary analyses of National Longitudinal Transition Study 2 (NLTS2) data, with a primary focus upon statistical objectives, paradigms, inferences, and methods. Its primary purpose was to determine which statistical techniques have been common in secondary analyses of NLTS2 data. The review begins with an…

Mentoring and Succession of Administrators: Critical Issues in Public and Private Secondary Schools in Lagos State, Nigeria

Directory of Open Access Journals (Sweden)

S.A. Oladipo

2016-08-01

Full Text Available Studies have shown that the quality of outcome in Nigerian secondary schools is declining at an alarming rate due to shortage of required resources as well as leadership challenges. The challenges have been observed to be as a result of lack of mentoring which is not a common practice in school management in Nigeria. Consequently, this study investigated the extent to which mentoring as a strategy for administrators' succession plan impacts on the performance of their duties in public and private secondary schools in Lagos, Nigeria. The study adopted the descriptive survey design and administered a 25-item self-constructed questionnaire on participants. A total of 530 participants were randomly selected from the population of 4,350 senior teachers. The Participants were drawn from 145 secondary schools (91 public and 54 registered private in Education District IV of Lagos State. The findings showed that mentoring has significant impact on administrators' succession planning and that succession planning does not significantly differ in public and private secondary schools in Lagos State. The study concluded that leadership development is a critical factor in secondary school effectiveness and efficiency. Therefore, serving administrators as well as prospective administrators should be regularly evaluated to determine their training needs at different career stages. There should also be mentoring related policies to enhance the managerial skills, sense of competence and effectiveness of the prospective administrators.

Secondary laser cooling of strontium-88 atoms

Energy Technology Data Exchange (ETDEWEB)

Strelkin, S. A.; Khabarova, K. Yu., E-mail: kseniakhabarova@gmail.com; Galyshev, A. A.; Berdasov, O. I.; Gribov, A. Yu.; Kolachevsky, N. N.; Slyusarev, S. N. [Federal State Unitary Enterprise “All-Russia Research Institute for Physicotechnical and Radio Engineering Measurements” (VNIIFTRI) (Russian Federation)

2015-07-15

The secondary laser cooling of a cloud of strontium-88 atoms on the {sup 1}S{sub 0}–{sup 3}P{sub 1} (689 nm) intercombination transition captured into a magneto-optical trap has been demonstrated. We describe in detail the recapture of atoms from the primary trap operating on the strong {sup 1}S{sub 0}–{sup 1}P{sub 1} (461 nm) transition and determine the recapture coefficient κ, the number of atoms, and their temperature in the secondary trap as a function of experimental parameters. A temperature of 2 µK has been reached in the secondary trap at the recapture coefficient κ = 6%, which confirms the secondary cooling efficiency and is sufficient to perform metrological measurements of the {sup 1}S{sub 0}–{sup 3}P{sub 1} (698 nm) clock transition in an optical lattice.

Achievable Rate of a Cognitive MIMO Multiple Access Channel With Multi-Secondary Users

KAUST Repository

Sboui, Lokman; Ghazzai, Hakim; Rezki, Zouheir; Alouini, Mohamed-Slim

2015-01-01

We study the secondary sum-rate of an underlay cognitive multiple access channel consisting of a primary user and multiple secondary users (SUs) communicating with a common destination. We propose a particular linear precoding and SU selection scheme that maximize the cognitive sum-rate. This scheme is based on space alignment strategy allowing SUs to share the spectrum without interfering with each other. We derive the optimal power allocation for each selected SU after applying perfect or imperfect successive interference cancellation. Numerical results show that the proposed scheme provides a significant sum-rate improvement as the number of SUs increases. In addition, it achieves almost the same performance as an exhaustive search selection, mainly in low and high power ranges. © 1997-2012 IEEE.

Achievable Rate of a Cognitive MIMO Multiple Access Channel With Multi-Secondary Users

KAUST Repository

Sboui, Lokman

2015-03-01

We study the secondary sum-rate of an underlay cognitive multiple access channel consisting of a primary user and multiple secondary users (SUs) communicating with a common destination. We propose a particular linear precoding and SU selection scheme that maximize the cognitive sum-rate. This scheme is based on space alignment strategy allowing SUs to share the spectrum without interfering with each other. We derive the optimal power allocation for each selected SU after applying perfect or imperfect successive interference cancellation. Numerical results show that the proposed scheme provides a significant sum-rate improvement as the number of SUs increases. In addition, it achieves almost the same performance as an exhaustive search selection, mainly in low and high power ranges. © 1997-2012 IEEE.

Metabolic engineering with systems biology tools to optimize production of prokaryotic secondary metabolites

DEFF Research Database (Denmark)

Kim, Hyun Uk; Charusanti, Pep; Lee, Sang Yup

2016-01-01

Metabolic engineering using systems biology tools is increasingly applied to overproduce secondary metabolites for their potential industrial production. In this Highlight, recent relevant metabolic engineering studies are analyzed with emphasis on host selection and engineering approaches...... for the optimal production of various prokaryotic secondary metabolites: native versus heterologous hosts (e.g., Escherichia coli) and rational versus random approaches. This comparative analysis is followed by discussions on systems biology tools deployed in optimizing the production of secondary metabolites....... The potential contributions of additional systems biology tools are also discussed in the context of current challenges encountered during optimization of secondary metabolite production....

Reinventing Natural Selection

Science.gov (United States)

Geraedts, Caspar L.; Boersma, Kerst Th.

2006-01-01

Although many research studies report students' Lamarckian misconceptions, only a few studies present learning and teaching strategies that focus on the successful development of the concept of natural selection. The learning and teaching strategy for upper secondary students (aged 15-16) presented in this study conducted in The Netherlands is…

Improved Technique for the Determination of Uranium Minor Isotopes Concentrations in Microparticles by Using Secondary Ion Mass-Spectrometer in Multicollection Mode

International Nuclear Information System (INIS)

Aleshin, M.; Elantyev, I.; Stebelkov, Y.

2015-01-01

Traditional method of the analysis implies simultaneous measuring of secondary ion currents of isotopes 234U + , 235U + , 238U + , ions with mass 236 amu (236U + and 235UH + ) and hydride ions 238UH + by using mass-spectrometer Cameca IMS1280 in multicollection mode. Calculating of uranium isotopic composition is performed using the results of 40 successive measurements of those currents (cycles). Duration of each measurement is 8 s. Small amounts of uranium minor isotopes are limitation for precise determination of their concentrations. To prevent the damage of the secondary ions detector the intensity of ion current should be no more than 5 x 10 5 s -1 . This limitation does not allow setting a higher primary ion current for the increasing of minor uranium isotopes ions emission because of the signal of ions 238U + gets too high. New technique is developed to improve the accuracy of determination of uranium minor isotopes concentrations. Process of measurement is divided on two steps. First step is a measurement of ion currents during 20 cycles by five detectors. The second step implies the elimination of ions 238U + hitting to the detector and 10 times increasing of primary ion current. The ratio 235U/238U is calculated from the first step results, so uncertainty of determination of this value is 1.4 times bigger than with duration of 40 cycles of the measurement. The ratios 234U/235U and 236U/235U are calculated during the second step. This technique allows to determine content of 234U and 236U with 3 and 5 times less uncertainties respectively, but with different degree of the sputtering particles. Moreover the duration of each cycle was set less (1 second) to use data more efficient. The technique accordingly with every second counting provides uncertainty of determination 236U concentration 4 times less than traditional method at the same degree of sputtering particles. (author)

Evaluation of alternate secondary (and tertiary) coolants for the molten-salt breeder reactor

International Nuclear Information System (INIS)

Kelmers, A.D.; Baes, C.F.; Bettis, E.S.; Brynestad, J.; Cantor, S.; Engel, J.R.; Grimes, W.R.; McCoy, H.E.; Meyer, A.S.

1976-04-01

The three most promising coolant selections for an MSBR have been identified and evaluated in detail from the many coolants considered for application either as a secondary coolant in 1000-MW(e) MSBR configurations using only one coolant, or as secondary and tertiary coolants in an MSBR dual coolant configuration employing two different coolants. These are, as single secondary coolants: (1) a ternary sodium--lithium--beryllium fluoride melt; (2) the sodium fluoroborate--sodium fluoride eutectic melt, the present reference design secondary coolant. In the case of the dual coolant configuration, the preferred system is molten lithium--beryllium fluoride (Li 2 BeF 4 ) as the secondary coolant and helium gas as the tertiary coolant

Selection of Models for Ingestion Pathway and Relocation Radii Determination

International Nuclear Information System (INIS)

Blanchard, A.

1998-01-01

The distance at which intermediate phase protective actions (such as food interdiction and relocation) may be needed following postulated accidents at three Savannah River Site nonreactor nuclear facilities will be determined by modeling. The criteria used to select dispersion/deposition models are presented. Several models were considered, including ARAC, MACCS, HOTSPOT, WINDS (coupled with PUFF-PLUME), and UFOTRI. Although ARAC and WINDS are expected to provide more accurate modeling of atmospheric transport following an actual release, analyses consistent with regulatory guidance for planning purposes may be accomplished with comparatively simple dispersion models such as HOTSPOT and UFOTRI. A recommendation is made to use HOTSPOT for non-tritium facilities and UFOTRI for tritium facilities

Structural determinants for selective recognition of peptide ligands for endothelin receptor subtypes ETA and ETB.

Science.gov (United States)

Lättig, Jens; Oksche, Alexander; Beyermann, Michael; Rosenthal, Walter; Krause, Gerd

2009-07-01

The molecular basis for recognition of peptide ligands endothelin-1, -2 and -3 in endothelin receptors is poorly understood. Especially the origin of ligand selectivity for ET(A) or ET(B) is not clearly resolved. We derived sequence-structure-function relationships of peptides and receptors from mutational data and homology modeling. Our major findings are the dissection of peptide ligands into four epitopes and the delineation of four complementary structural portions on receptor side explaining ligand recognition in both endothelin receptor subtypes. In addition, structural determinants for ligand selectivity could be described. As a result, we could improve the selectivity of BQ3020 about 10-fold by a single amino acid substitution, validating our hypothesis for ligand selectivity caused by different entrances to the receptors' transmembrane binding sites. A narrow tunnel shape in ET(A) is restrictive for a selected group of peptide ligands' N-termini, whereas a broad funnel-shaped entrance in ET(B) accepts a variety of different shapes and properties of ligands.

Decision Support System for Determining Scholarship Selection using an Analytical Hierarchy Process

Science.gov (United States)

Puspitasari, T. D.; Sari, E. O.; Destarianto, P.; Riskiawan, H. Y.

2018-01-01

Decision Support System is a computer program application that analyzes data and presents it so that users can make decision more easily. Determining Scholarship Selection study case in Senior High School in east Java wasn’t easy. It needed application to solve the problem, to improve the accuracy of targets for prospective beneficiaries of poor students and to speed up the screening process. This research will build system uses the method of Analytical Hierarchy Process (AHP) is a method that solves a complex and unstructured problem into its group, organizes the groups into a hierarchical order, inputs numerical values instead of human perception in comparing relative and ultimately with a synthesis determined elements that have the highest priority. The accuracy system for this research is 90%.

Sol-gel based sensor for selective formaldehyde determination

Energy Technology Data Exchange (ETDEWEB)

Bunkoed, Opas [Trace Analysis and Biosensor Research Center, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand); Department of Chemistry and Center for Innovation in Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand); Davis, Frank [Cranfield Health, Cranfield University, Bedford MK43 0AL (United Kingdom); Kanatharana, Proespichaya, E-mail: proespichaya.K@psu.ac.th [Trace Analysis and Biosensor Research Center, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand); Department of Chemistry and Center for Innovation in Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand); Thavarungkul, Panote [Trace Analysis and Biosensor Research Center, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand); Department of Physics, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand); Higson, Seamus P.J., E-mail: s.p.j.higson@cranfield.ac.uk [Cranfield Health, Cranfield University, Bedford MK43 0AL (United Kingdom)

2010-02-05

We report the development of transparent sol-gels with entrapped sensitive and selective reagents for the detection of formaldehyde. The sampling method is based on the adsorption of formaldehyde from the air and reaction with {beta}-diketones (for example acetylacetone) in a sol-gel matrix to produce a yellow product, lutidine, which was detected directly. The proposed method does not require preparation of samples prior to analysis and allows both screening by visual detection and quantitative measurement by simple spectrophotometry. The detection limit of 0.03 ppmv formaldehyde is reported which is lower than the maximum exposure concentrations recommended by both the World Health Organisation (WHO) and the Occupational Safety and Health Administration (OSHA). This sampling method was found to give good reproducibility, the relative standard deviation at 0.2 and 1 ppmv being 6.3% and 4.6%, respectively. Other carbonyl compounds i.e. acetaldehyde, benzaldehyde, acetone and butanone do not interfere with this analytical approach. Results are provided for the determination of formaldehyde in indoor air.

Sol-gel based sensor for selective formaldehyde determination

International Nuclear Information System (INIS)

Bunkoed, Opas; Davis, Frank; Kanatharana, Proespichaya; Thavarungkul, Panote; Higson, Seamus P.J.

2010-01-01

We report the development of transparent sol-gels with entrapped sensitive and selective reagents for the detection of formaldehyde. The sampling method is based on the adsorption of formaldehyde from the air and reaction with β-diketones (for example acetylacetone) in a sol-gel matrix to produce a yellow product, lutidine, which was detected directly. The proposed method does not require preparation of samples prior to analysis and allows both screening by visual detection and quantitative measurement by simple spectrophotometry. The detection limit of 0.03 ppmv formaldehyde is reported which is lower than the maximum exposure concentrations recommended by both the World Health Organisation (WHO) and the Occupational Safety and Health Administration (OSHA). This sampling method was found to give good reproducibility, the relative standard deviation at 0.2 and 1 ppmv being 6.3% and 4.6%, respectively. Other carbonyl compounds i.e. acetaldehyde, benzaldehyde, acetone and butanone do not interfere with this analytical approach. Results are provided for the determination of formaldehyde in indoor air.

Shadow Education in Malaysia: Identifying the Determinants of Spending and Amount of Time Attending Private Supplementary Tutoring of Upper Secondary School Students

Directory of Open Access Journals (Sweden)

Chang Da Wan

2017-10-01

Full Text Available This paper examines the determinants of spending and the amount of time attending private supplementary tutoring, or commonly known as private tuition, in Malaysia. Based on 343 self-reported questionnaires with upper secondary students across three states in Malaysia and using multiple regression analysis, we identified ethnicity, father’s level of education and past academic performance as significant determinants of spending and amount of time attending private tuition. However, interestingly, we found that while geographical location and participation in internal tuition in schools were also determinants of spending, these two were not significant in determining the amount of time attending private supplementary tutoring. The identification of determinants of spending and amount of time, and in addition, the differences between these two illustrates the economic and educational dimensions of shadow education. More importantly, the insight also contributes to the formulation of possible interventions that can improve quality and reduce inequality in the mainstream education system.

Interference-aware random beam selection for spectrum sharing systems

KAUST Repository

Abdallah, Mohamed M.

2012-09-01

Spectrum sharing systems have been introduced to alleviate the problem of spectrum scarcity by allowing secondary unlicensed networks to share the spectrum with primary licensed networks under acceptable interference levels to the primary users. In this paper, we develop interference-aware random beam selection schemes that provide enhanced throughput for the secondary link under the condition that the interference observed at the primary link is within a predetermined acceptable value. For a secondary transmitter equipped with multiple antennas, our schemes select a random beam, among a set of power- optimized orthogonal random beams, that maximizes the capacity of the secondary link while satisfying the interference constraint at the primary receiver for different levels of feedback information describing the interference level at the primary receiver. For the proposed schemes, we develop a statistical analysis for the signal-to-noise and interference ratio (SINR) statistics as well as the capacity of the secondary link. Finally, we present numerical results that study the effect of system parameters including number of beams and the maximum transmission power on the capacity of the secondary link attained using the proposed schemes. © 2012 IEEE.

Source apportionment and location by selective wind sampling and Positive Matrix Factorization.

Science.gov (United States)

Venturini, Elisa; Vassura, Ivano; Raffo, Simona; Ferroni, Laura; Bernardi, Elena; Passarini, Fabrizio

2014-10-01

In order to determine the pollution sources in a suburban area and identify the main direction of their origin, PM2.5 was collected with samplers coupled with a wind select sensor and then subjected to Positive Matrix Factorization (PMF) analysis. In each sample, soluble ions, organic carbon, elemental carbon, levoglucosan, metals, and Polycyclic Aromatic Hydrocarbons (PAHs) were determined. PMF results identified six main sources affecting the area: natural gas home appliances, motor vehicles, regional transport, biomass combustion, manufacturing activities, and secondary aerosol. The connection of factor temporal trends with other parameters (i.e., temperature, PM2.5 concentration, and photochemical processes) confirms factor attributions. PMF analysis indicated that the main source of PM2.5 in the area is secondary aerosol. This should be mainly due to regional contributions, owing to both the secondary nature of the source itself and the higher concentration registered in inland air masses. The motor vehicle emission source contribution is also important. This source likely has a prevalent local origin. The most toxic determined components, i.e., PAHs, Cd, Pb, and Ni, are mainly due to vehicular traffic. Even if this is not the main source in the study area, it is the one of greatest concern. The application of PMF analysis to PM2.5 collected with this new sampling technique made it possible to obtain more detailed results on the sources affecting the area compared to a classical PMF analysis.

Selective masking and demasking for the stepwise complexometric determination of aluminium, lead and zinc from the same solution

OpenAIRE

Kayal, Nijhuma; Singh, Nahar

2008-01-01

Abstract Background A complexometric method based on selective masking and de-masking has been developed for the rapid determination of aluminium, lead and zinc from the same solution in glass and glass frit samples. The determination is carried out using potassium cyanide to mask zinc, and excess disodium salt of EDTA to mask lead and aluminium. The excess EDTA was titrated with standard Mn(II)SO4 solution using Erichrome Black-T as the indicator. Subsequently selective de-masking agents – t...

Experimental Characterization and Hygroscopicity Determination of Secondary Aerosol from D5 Cyclic Siloxane Oxidation

Science.gov (United States)

Stanier, C. O.; Janechek, N. J.; Bryngelson, N.; Marek, R. F.; Lersch, T.; Bunker, K.; Casuccio, G.; Brune, W. H.; Hornbuckle, K. C.

2017-12-01

Cyclic volatile methyl siloxanes are anthropogenic chemicals present in personal care products such as antiperspirants and lotions. These are volatile chemicals that are readily released into the atmosphere by product use. Due to their emission and relatively slow kinetics of their major transformation pathway, reaction with hydroxyl radicals (OH), these compounds are present in high concentrations in indoor environments and widespread in outdoor environments. Cyclic siloxane reaction with OH can lead to secondary organic aerosols, and due to the widespread prevalence of the parent compounds, may be an important source of ambient aerosols. Atmospheric aerosols have important influences to the climate by affecting the radiative balance and by serving as cloud condensation nuclei (CCN) which influence clouds. While the parent compounds have been well-studied, the oxidation products have received much less attention, with almost no ambient measurements or experimental physical property data. We report physical properties of aerosols generated by reacting the cyclic siloxane D5 with OH using a Potential Aerosol Mass (PAM) photochemical chamber. The particles were characterized by SMPS, imaging and elemental analysis using both Transmission Electron Microscopy and Scanning Transmission Electron Microscopy equipped with Energy Dispersive X-ray Spectroscopy systems (TEM-EDS and STEM-EDS), volatility measurements using Volatility Tandem Differential Mobility Analyzer (V-TDMA), and hygroscopicity measurements to determine CCN potential using a Droplet Measurement Technologies Cloud Condensation Nuclei Counter (DMT-CCN). Aerosol yield sensitivity to D5 and OH concentrations, residence time, and seed aerosols were analyzed. TEM-EDS and STEM-EDS analysis show spherical particle morphology with elemental composition consistent with aerosols derived from cyclic siloxane sources. Measured aerosol yields were 20-50% with typical aerosol concentrations 300,000 particles cm-3, up to

Evaluation Considerations for Secondary Uses of Clinical Data: Principles for an Evidence-based Approach to Policy and Implementation of Secondary Analysis.

Science.gov (United States)

Scott, P J; Rigby, M; Ammenwerth, E; McNair, J Brender; Georgiou, A; Hyppönen, H; de Keizer, N; Magrabi, F; Nykänen, P; Gude, W T; Hackl, W

2017-08-01

Objectives: To set the scientific context and then suggest principles for an evidence-based approach to secondary uses of clinical data, covering both evaluation of the secondary uses of data and evaluation of health systems and services based upon secondary uses of data. Method: Working Group review of selected literature and policy approaches. Results: We present important considerations in the evaluation of secondary uses of clinical data from the angles of governance and trust, theory, semantics, and policy. We make the case for a multi-level and multi-factorial approach to the evaluation of secondary uses of clinical data and describe a methodological framework for best practice. We emphasise the importance of evaluating the governance of secondary uses of health data in maintaining trust, which is essential for such uses. We also offer examples of the re-use of routine health data to demonstrate how it can support evaluation of clinical performance and optimize health IT system design. Conclusions: Great expectations are resting upon "Big Data" and innovative analytics. However, to build and maintain public trust, improve data reliability, and assure the validity of analytic inferences, there must be independent and transparent evaluation. A mature and evidence-based approach needs not merely data science, but must be guided by the broader concerns of applied health informatics. Georg Thieme Verlag KG Stuttgart.

Secondary Analysis under Cohort Sampling Designs Using Conditional Likelihood

Directory of Open Access Journals (Sweden)

Olli Saarela

2012-01-01

Full Text Available Under cohort sampling designs, additional covariate data are collected on cases of a specific type and a randomly selected subset of noncases, primarily for the purpose of studying associations with a time-to-event response of interest. With such data available, an interest may arise to reuse them for studying associations between the additional covariate data and a secondary non-time-to-event response variable, usually collected for the whole study cohort at the outset of the study. Following earlier literature, we refer to such a situation as secondary analysis. We outline a general conditional likelihood approach for secondary analysis under cohort sampling designs and discuss the specific situations of case-cohort and nested case-control designs. We also review alternative methods based on full likelihood and inverse probability weighting. We compare the alternative methods for secondary analysis in two simulated settings and apply them in a real-data example.

Determination of the Influence of Substrate Concentration on Enzyme Selectivity Using Whey Protein Isolate and Bacillus licheniformis Protease

NARCIS (Netherlands)

Butré, C.I.; Sforza, S.; Gruppen, H.; Wierenga, P.A.

2014-01-01

Increasing substrate concentration during enzymatic protein hydrolysis results in a decrease in hydrolysis rate. To test if changes in the mechanism of hydrolysis also occur, the enzyme selectivity was determined. The selectivity is defined quantitatively as the relative rate of hydrolysis of each

RNA STRAND: The RNA Secondary Structure and Statistical Analysis Database

Directory of Open Access Journals (Sweden)

Andronescu Mirela

2008-08-01

Full Text Available Abstract Background The ability to access, search and analyse secondary structures of a large set of known RNA molecules is very important for deriving improved RNA energy models, for evaluating computational predictions of RNA secondary structures and for a better understanding of RNA folding. Currently there is no database that can easily provide these capabilities for almost all RNA molecules with known secondary structures. Results In this paper we describe RNA STRAND – the RNA secondary STRucture and statistical ANalysis Database, a curated database containing known secondary structures of any type and organism. Our new database provides a wide collection of known RNA secondary structures drawn from public databases, searchable and downloadable in a common format. Comprehensive statistical information on the secondary structures in our database is provided using the RNA Secondary Structure Analyser, a new tool we have developed to analyse RNA secondary structures. The information thus obtained is valuable for understanding to which extent and with which probability certain structural motifs can appear. We outline several ways in which the data provided in RNA STRAND can facilitate research on RNA structure, including the improvement of RNA energy models and evaluation of secondary structure prediction programs. In order to keep up-to-date with new RNA secondary structure experiments, we offer the necessary tools to add solved RNA secondary structures to our database and invite researchers to contribute to RNA STRAND. Conclusion RNA STRAND is a carefully assembled database of trusted RNA secondary structures, with easy on-line tools for searching, analyzing and downloading user selected entries, and is publicly available at http://www.rnasoft.ca/strand.

Secondary Textbook Review: English, Grades Nine through Twelve.

Science.gov (United States)

California State Dept. of Education, Sacramento.

This book is intended as a resource for teachers and curriculum developers who select textbooks for secondary English courses. It includes a compilation of 32 factual textbook reviews obtained from the application of a review instrument, which was based on the California "Model Curriculum Standards: Grades Nine through Twelve, English…

Corporal punishment and disciplinary control of secondary school ...

African Journals Online (AJOL)

This study was carried out to examine and analyze the use of corporal punishment in disciplinary control of secondary schools students in Delta State. Two research questions were raised and one hypothesis was generated and tested. 515 principals were selected through the use of the multi-stage random sampling ...

Determinants of capital structure: evidence from the Czech automotive industry

Directory of Open Access Journals (Sweden)

Pavlína Pinková

2012-01-01

Full Text Available The objective of the paper is to identify the determinants influencing the capital structure of large and medium-sized enterprises of the automotive industry in the Czech Republic. The sample consists of 100 companies belonging to NACE division 29. The data come from financial statements of selected companies and cover a period from 2006 to 2010. For the purpose of the paper quantitative research is used. The selection of appropriate dependent and independent is realized on the basis of secondary research on studies of capital structure. The analysis of variance, correlation and regression analyses have been performed to see the nature of relationship between variables. Size, tangibility, profitability and liquidity appear to be relevant determinants of capital structure. Growth is not a statistically significant determinant of leverage. It has been observed that the maturity of debt has to be considered, since the investigation of total debt only does not provide precious results. The findings do not unequivocally support either the static trade-off theory or the pecking order theory.

Stimulant use among secondary school students in Osogbo, Nigeria.

Science.gov (United States)

Eegunranti, B A; Fatoye, F O; Morakinyo, O

2009-09-01

The objectives of this study were to determine the prevalence and pattern of stimulant use and its association with 'brain fag syndrome' among secondary school students in Osogbo, Osun State. The study also aimed to determine the association of socio-demographic variables (of the students and their parents) with stimulant use. A questionnaire consisting of sociodemographic variables, the stimulant use section of the WHO Student Drug Use Questionnaire and the Brain Fag Syndrome Scale (BFSS) was administered on randomly selected students of the two Local Government Areas of Osogbo. The prevalence rates of stimulant use were calculated and the association of stimulant use with Brain Fag Syndrome (BFS) and socio-demographic variables was determined. The 30-day prevalence rate of stimulant use was 20.3%. Users engaged more in the use of common and cheap stimulants (coffee and kola nut). Majority of users started at age 13 years or below. There was a very high relationship between stimulant use and the symptoms of the BFS (pfather and the description of mother as being too permissive. The findings suggest the need to increase the awareness of the dangers of stimulant use among students. Control programmes are urgently needed to prevent student wastage.

Bio-sniffer (gas-phase biosensor) with secondary alcohol dehydrogenase (S-ADH) for determination of isopropanol in exhaled air as a potential volatile biomarker.

Science.gov (United States)

Chien, Po-Jen; Suzuki, Takuma; Tsujii, Masato; Ye, Ming; Toma, Koji; Arakawa, Takahiro; Iwasaki, Yasuhiko; Mitsubayashi, Kohji

2017-05-15

Exhaled breath analysis has attracted lots of researchers attention in the past decades due to its advantages such as its non-invasive property and the possibility of continuous monitoring. In addition, several volatile organic compounds in breath have been identified as biomarkers for some diseases. Particularly, studies have pointed out that concentration of isopropanol (IPA) in exhaled air might relate with certain illnesses such as liver disease, chronic obstructive pulmonary (COPD), and lung cancer. In this study, a highly sensitive and selective biochemical gas sensor (bio-sniffer) for the breath IPA concentration determination was constructed and optimized. This bio-sniffer measures the concentration of IPA according to the fluorescence intensity of oxidized nicotinamide adenine dinucleotide (NADH), which was produced by an enzymatic reaction of secondary alcohol dehydrogenase (S-ADH). The NADH detection system employed an UV-LED as the excitation light, and a highly sensitive photomultiplier tube (PMT) as a fluorescence intensity detector. A gas-sensing region was developed using an optical fiber probe equipped with a flow-cell and enzyme immobilized membrane, and connected to the NADH measurement system. The calibration range of the IPA bio-sniffer was confirmed from 1ppb to 9060ppb that was comparable to other IPA analysis methods. The results of the analysis of breath IPA concentration in healthy subjects using the bio-sniffer showed a mean concentration of 16.0ppb, which was similar to other studies. These results have demonstrated that this highly sensitive and selective bio-sniffer could be used to measure the IPA in exhaled air, and it is expected to apply for breath IPA research and investigation of biomarkers for clinical diagnosis. Copyright © 2016 Elsevier B.V. All rights reserved.

Ionic Liquid Crystals Modifier for Selective Determination of Terazosin Antihypertensive Drug in Presence of Common Interference Compounds

Directory of Open Access Journals (Sweden)

Nada F. Atta

2017-01-01

Full Text Available Electrochemical sensor was fabricated based on carbon paste electrode modified with an ionic liquid crystal ILC (2-chloro-1,3-dimethyl-imidazolidinium hexafluorophosphate in presence of sodium dodecyl sulfate for the selective electrochemical determination of Terazosin (TZ in presence of common interference compounds. The electrode performance was compared in presence of other ionic liquids ILs (1-Butyl-4-methyl pyridinium tetrafluoroborate and (1-n-Hexyl-3-methyl imidazolium tetrafluoroborate. Ultrasensitive determination of Terazosin HCl at the ILC modified electrode in the linear dynamic ranges of 0.002 to 0.09 μmol·L−1 and 0.2 to 30 μmol·L−1 with correlation coefficients 0.996 and 0.995 and LODs 1.69 × 10−11 mol·L−1 and 6.43 × 10−9 mol·L−1, respectively, were obtained. Selective determination of TZ in presence of uric acid and ascorbic acid and simultaneous determination of binary mixtures of TZ/dopamine, TZ/paracetamol and TZ/Morphine were also determined successfully using the modified sensor.

Economic literacy amongst the secondary school teachers in Perak Malaysia

Directory of Open Access Journals (Sweden)

Nek Kamal Yeop Yunus, Norasibah Abdul Jalil

2011-01-01

Full Text Available The aim of the study is to determine the relationship between economics education exposure, saving, expenditure, investment and economics literacy amongst teachers in secondary schools in Perak. The theoretical framework was designed based on the literature and hence five hypotheses for the study were formulated. The samples were selected by quota sampling methods. The data were collected by distributing structured 35 items questionnaires to 100 teachers in secondary schools in eight districts in Perak. The instrument was adapted form Leader Behaviour Description Questionnaires which were used to measure economic literacy. Only 60 questionnaires were returned and analysed which gave 60% respond rate. Data collected were sorted out and keyed in into SPSS version 17. The data were analysed using descriptive and inferential statistics to answer the research questions. The result of the analyses showed that there was significant relationship between economics education and its predictors. Together the independent variables explained 81.7% of the variance in the dependent variables. The remaining 18.3% was due to unidentified variables. In relation to that, the study had contributed some knowledge about the understanding of economic of literacy. For future research, it is recommended that other than the above variables might influence economic literacy perhaps with a bigger samples and wider scope.

Uncertainty analysis for secondary energy distributions

International Nuclear Information System (INIS)

Gerstl, S.A.W.

1978-01-01

In many transport calculations the integral design parameter of interest (response) is determined mainly by secondary particles such as gamma rays from (n,γ) reactions or secondary neutrons from inelastic scattering events or (n,2n) reactions. Standard sensitivity analysis usually allows to calculate the sensitivities to the production cross sections of such secondaries, but an extended formalism is needed to also obtain the sensitivities to the energy distribution of the generated secondary particles. For a 30-group standard cross-section set 84% of all non-zero table positions pertain to the description of secondary energy distributions (SED's) and only 16% to the actual reaction cross sections. Therefore, any sensitivity/uncertainty analysis which does not consider the effects of SED's is incomplete and neglects most of the input data. This paper describes the methods of how sensitivity profiles for SED's are obtained and used to estimate the uncertainty of an integral response due to uncertainties in these SED's. The detailed theory is documented elsewhere and implemented in the LASL sensitivity code SENSIT. SED sensitivity profiles have proven particularly valuable in cross-section uncertainty analyses for fusion reactors. Even when the production cross sections for secondary neutrons were assumed to be without error, the uncertainties in the energy distribution of these secondaries produced appreciable uncertainties in the calculated tritium breeding rate. However, complete error files for SED's are presently nonexistent. Therefore, methods will be described that allow rough error estimates due to estimated SED uncertainties based on integral SED sensitivities

Transforming Nigerian Youth Leadership Capacities in Secondary Schools through Principals' Managerial Role Effectiveness

Science.gov (United States)

Edet, Aniefiok Oswald; Ekpoh, Uduak Imo; Uko, Esther Samuel

2015-01-01

The study examined principals' management role effectiveness of secondary schools for youth leadership in Calabar Education Zone of Cross River State. The study employed survey research design. The target population comprised all 158 principals in both public and private secondary schools in the study area. The sample selected through random…

Quantitation of base substitutions in eukaryotic 5S rRNA: selection for the maintenance of RNA secondary structure.

Science.gov (United States)

Curtiss, W C; Vournakis, J N

1984-01-01

Eukaryotic 5S rRNA sequences from 34 diverse species were compared by the following method: (1) The sequences were aligned; (2) the positions of substitutions were located by comparison of all possible pairs of sequences; (3) the substitution sites were mapped to an assumed general base pairing model; and (4) the R-Y model of base stacking was used to study stacking pattern relationships in the structure. An analysis of the sequence and structure variability in each region of the molecule is presented. It was found that the degree of base substitution varies over a wide range, from absolute conservation to occurrence of over 90% of the possible observable substitutions. The substitutions are located primarily in stem regions of the 5S rRNA secondary structure. More than 88% of the substitutions in helical regions maintain base pairing. The disruptive substitutions are primarily located at the edges of helical regions, resulting in shortening of the helical regions and lengthening of the adjacent nonpaired regions. Base stacking patterns determined by the R-Y model are mapped onto the general secondary structure. Intrastrand and interstrand stacking could stabilize alternative coaxial structures and limit the conformational flexibility of nonpaired regions. Two short contiguous regions are 100% conserved in all species. This may reflect evolutionary constraints imposed at the DNA level by the requirement for binding of a 5S gene transcription initiation factor during gene expression.

Bismuth Modified Carbon-Based Electrodes for the Determination of Selected Neonicotinoid Insecticides

Directory of Open Access Journals (Sweden)

Marko Rodić

2011-05-01

Full Text Available Two types of bismuth modified electrodes, a bismuth-film modified glassy carbon (BiF-GCE and a bismuth bulk modified carbon paste, were applied for the determination of selected nitroguanidine neonicotinoid insecticides. The method based on an ex situ prepared BiF-GCE operated in the differential pulse voltammetric (DPV mode was applied to determine clothianidin in the concentration range from 2.5 to 23 μg cm−3 with a relative standard deviation (RSD not exceeding 1.5%. The tricresyl phosphate-based carbon paste electrodes (TCP-CPEs, bulk modified with 5 and 20 w/w% of bismuth, showed a different analytical performance in the determination of imidacloprid, regarding the peak shape, potential window, and noise level. The TCP-CPE with 5% Bi was advantageous, and the developed DPV method based on it allowed the determination in the concentration range from 1.7 to 60 μg cm−3 with an RSD of 2.4%. To get a deeper insight into the morphology of the bismuth-based sensor surfaces, scanning electron microscopic measurements were performed of both the surface film and the bulk modified electrodes.

Determination of chlorine in nuclear-grade uranium compounds by ion-selective electrode

International Nuclear Information System (INIS)

Yang Chunqing; Liu Fuyun; Huang Dianfan.

1989-01-01

The determination of microamount chlorine in nuclear-grade uranium compounds is described. Chlorine is separated from uranium oxide pyrohydrolytically with stream of wet oxygen in a furnace at 800-900 deg C. Chlorine is volatilized as hydrochloric acid, which then is absorbed in a dilute alkaline solution and measured with chlorine selective electrode. This method covers the concentration range of 10-500 ppm chlorine in uranium oxide. The relative standard diviation is better than 10% and recovery of 85-108% has been reported

Influence of Niche-Specific Nutrients on Secondary Metabolism in Vibrionaceae

DEFF Research Database (Denmark)

Giubergia, Sonia; Phippen, Christopher; Gotfredsen, Charlotte Held

2016-01-01

was responsible for the antibacterial activity of Vibrio furnissii and Vibrio fluvialis These results suggest a role of chitin in the regulation of secondary metabolism in vibrios and demonstrate that considering bacterial ecophysiology during development of screening strategies will facilitate bioprospecting......Many factors, such as the substrate and the growth phase, influence biosynthesis of secondary metabolites in microorganisms. Therefore, it is crucial to consider these factors when establishing a bioprospecting strategy. Mimicking the conditions of the natural environment has been suggested...... as a means of inducing or influencing microbial secondary metabolite production. The purpose of the present study was to determine how the bioactivity of Vibrionaceae was influenced by carbon sources typical of their natural environment. We determined how mannose and chitin, compared to glucose, influenced...

Is floral divergence sufficient to maintain species boundaries upon secondary contact in Mediterranean food-deceptive orchids?

Science.gov (United States)

Zitari, A; Scopece, G; Helal, A N; Widmer, A; Cozzolino, S

2012-01-01

Analyzing the processes that determine whether species boundaries are maintained on secondary contact may shed light on the early phase of speciation. In Anacamptis morio and Anacamptis longicornu, two Mediterranean orchid sister-species, we used molecular and morphological analyses, together with estimates of pollination success and experimental crosses, to assess whether floral isolation can shelter the species' genomes from genetic admixture on secondary contact. We found substantial genetic and morphological homogenization in sympatric populations in combination with an apparent lack of postmating isolation. We further detected asymmetric introgression in the sympatric populations and an imbalance in cytotype representation, which may be due either to a difference in flowering phenology or else be a consequence of cytonuclear incompatibilities. Estimates of genetic clines for markers across sympatric zones revealed markers that significantly deviated from neutral expectations. We observed a significant correlation between spur length and reproductive success in sympatric populations, which may suggest that directional selection is the main cause of morphological differentiation in this species pair. Our results suggest that allopatric divergence has not led to the evolution of sufficient reproductive isolation to prevent genomic admixture on secondary contact in this orchid species pair. PMID:21792224

Menarche and Its Determinants in Adolescent Girls

Directory of Open Access Journals (Sweden)

Moushami Ghimire

2014-06-01

Full Text Available Introduction: Biological, psychosocial, cognitive, emotional and social changes begin during puberty and continue throughout adolescence. The age at which a female reaches sexual maturity is critical in determining her future reproductive health and success. The aim of the study was to assess the average age of sexual feeling and menarche among the adolescent girls and its determinants. Methods: Three hundred fifty five respondents were selected through simple random sampling from three secondary schools (namely Sunrise Boarding School, Swaraswati Secondary School and Gyanjyoti Samudayak Bidhyalaya in Palpa for the cross-sectional study. Structured interview schedule was used to collect information. Data was tabulated in Microsoft Excel spreadsheet and analyzed with SPSS-16. Results: Most of the girls (44.8% attained menarche at 12 years (M = 12.4, SD = 1.11. Age at menarche was more likely before 13 years of age when the age of onset of sexual feeling was earlier than 12 years of age, in students than in domestic workers and if they are living with parents than in those not living with parents. Conclusion: The average age of menarche among the adolescent girls was 12.40 years and it could be influenced by age of sexual feeling, occupation and living status of girls.

Clinical significance of combined measurement of serum sex hormones in secondary amenorrhea

International Nuclear Information System (INIS)

Chen Boxun; Chen Yue; Gan Xilun

2004-01-01

Objective: To study the clinical significance of changes of levels of serum sex hormones in the diagnosis of the types of secondary amenorrhea. Methods: Serum sex hormones levels were measured with chemiluminescence in 100 patients with secondary amenorrhea and 42 controls. The serum hormones determined were: estradiol (E 2 )-, progesterone (PROG), follicle stimulating hormone (FSH)-, luteinizing hormone (LH), prolactin (PRL), testosterone (TSTO). Results: Patients with secondary amenorrhea had significantly higher levels of serum FSH, LH and PRL ( P 2 (P<0.05) than those in the controls. Serum levels of PROG and TSTO were about the same in the patients and controls. Conclusion: Determination of serum hormones levels with chemiluminescence is clinically useful for diagnosis of the types of secondary amenorrhea. (authors)

Pure zinc sulfide quantum dot as highly selective luminescent probe for determination of hazardous cyanide ion

International Nuclear Information System (INIS)

Shamsipur, Mojtaba; Rajabi, Hamid Reza

2014-01-01

A rapid and simple fluorescence method is presented for selective and sensitive determination of hazardous cyanide ion in aqueous solution based on functionalized zinc sulfide (ZnS) quantum dot (QD) as luminescent prob. The ultra-small ZnS QDs were synthesized using a chemical co-precipitation method in the presence of 2-mercaptoethanol (ME) as an efficient capping agent. The prepared pure ZnS QDs was applied as an optical sensor for determination of cyanide ions in aqueous solutions. ZnS nanoparticles have exhibited a strong fluorescent emission at about 424 nm. The fluorescence intensity of QDs is linearly proportional to the cyanide ion concentration in the range 2.44 × 10 −6 to 2.59 × 10 −5 M with a detection limit of 1.70 × 10 −7 M at pH 11. The designed fluorescent sensor possesses remarkable selectivity for cyanide ion over other anions such as Cl − , Br − , F − , I − , IO 3 − , ClO 4 − , BrO 3 − , CO 3 2− , NO 2 − , NO 3 − , SO 4 2− , S 2 O 4 2− , C 2 O 4 2− , SCN − , N 3 − , citrate and tartarate with negligible influences on the cyanide detection by fluorescence spectroscopy. - Highlights: • Preparation of functionalized ZnS quantum dots in aqueous media • Highly selective quantum dot based luminescent probe for determination of cyanide • Fast and sensitive determination of hazardous CN − by fluorescence quenching

NNDSS - Table II. Spotted fever rickettsiosis to Syphilis, primary and secondary

Data.gov (United States)

U.S. Department of Health & Human Services — NNDSS - Table II. Spotted fever rickettsiosis to Syphilis, primary and secondary - 2018. In this Table, provisional cases of selected notifiable diseases (≥1,000...

Secondary Vocational Horticulture Programs--An Assessment.

Science.gov (United States)

Burnett, Michael F.; Smith, Charles W.

1983-01-01

The objectives of the study were to determine characteristics of secondary horticulture teachers, the structure of horticulture departments, funding sources, nature and scope of facilities, types of supervised occupational experience programs in which horticulture students participated, and curriculum characteristics of vocational horticulture…

Application of a Lithium-ion Selective Metallacrown to Extraction-Spectrophotometric Determination of Lithium in Saline Water.

Science.gov (United States)

Katsuta, Shoichi; Saito, Yuki; Takahashi, Suguru

2018-01-01

The solvent-extraction behavior of Li + and Na + with a Li + selective metallacrown, [{Ru(η 6 -3,5-dimethylanisole)(2,3-pyridinediolate)} 3 ], was investigated in the presence of organic dye anions, 3',3″,5',5″-tetrabromophenolphthalein ethyl ester ([TBPE] - ), 2,6-dichloroindophenolate, and picrate ([pic] - ). Each alkali metal ion was extracted as a 1:1:1 ternary complex of the metal ion, metallacrown, and anion. The Li + /Na + extraction selectivity is anion dependent and highest with [pic] - . Therefore, we devised an extraction-spectrophotometric determination method for Li + in saline water based on the extraction of Li + using the metallacrown and [pic] - for high selectivity and subsequent replacement of [pic] - in the extracted species with [TBPE] - for high sensitivity. When applying this to artificial seawater samples containing known concentrations of Li + , a linear relationship was observed between the absorbance at 571 nm of the organic phase and the Li + concentration in the samples. By this method, the determination of Li + at the sub-ppm level in natural seawater is possible.

Performance analysis of selective cooperation in underlay cognitive networks over Rayleigh channels

KAUST Repository

Hussain, Syed Imtiaz

2011-06-01

Underlay cognitive networks should follow strict interference thresholds to operate in parallel with primary networks. This constraint limits their transmission power and eventually the area of coverage. Therefore, it is very likely that the underlay networks will make use of relays to transmit signals to the distant secondary users. In this paper, we propose a secondary relay selection scheme which maximizes the end-to-end signal to noise ratio (SNR) for the secondary link while keeping the interference levels to the primary network below a certain threshold. We derive closed form expressions for the probability density function (PDF) of the SNR at the secondary destination, average bit error probability and outage probability. Analytical results are verified through simulations which also give insight about the benefits and tradeoffs of the selective cooperation in underlay cognitive networks. It is shown that, in contrast to non-cognitive selective cooperation, this scheme performs better in low SNR region for cognitive networks. © 2011 IEEE.

[Secondary hypertension].

Science.gov (United States)

Yoshida, Yuichi; Shibata, Hirotaka

2015-11-01

Hypertension is a common disease and a crucial predisposing factor of cardiovascular diseases. Approximately 10% of hypertensive patients are secondary hypertension, a pathogenetic factor of which can be identified. Secondary hypertension consists of endocrine, renal, and other diseases. Primary aldosteronism, Cushing's syndrome, pheochromocytoma, hyperthyroidism, and hypothyroidism result in endocrine hypertension. Renal parenchymal hypertension and renovascular hypertension result in renal hypertension. Other diseases such as obstructive sleep apnea syndrome are also very prevalent in secondary hypertension. It is very crucial to find and treat secondary hypertension at earlier stages since most secondary hypertension is curable or can be dramatically improved by specific treatment. One should keep in mind that screening of secondary hypertension should be done at least once in a daily clinical practice.

Oak Ridge TNS program: evaluation of a secondary vacuum enclosure for TNS

Energy Technology Data Exchange (ETDEWEB)

Sardella, C.

1979-11-01

This report investigates the use of a secondary vacuum enclosure (SVE) to eliminate the need for high vacuum joints between torus sectors and thereby improve device maintainability. Several conceptual SVE designs have been identified and evaluated and the vacuum building was selected as the most promising. A mechanically assembled torus having high impedance seals (rather than vacuum tight seals) between sectors is described and the mechanical characteristics of the device are discussed. The size of the vacuum pump system and the pumpdown time for the vacuum building were determined. Studied also were the many aspects of the effect a vacuum environment has on tokamak systems. The potential benefits of using a SVE on a commercial reactor were investigated and stated in terms of improved plant availability. (MOW)

Transmit Antenna Selection for Power Adaptive Underlay Cognitive Radio with Instantaneous Interference Constraint

KAUST Repository

Hanif, Muhammad

2017-03-31

The high hardware cost associated with multiple antennas at the secondary transmitter of an underlay cognitive radio (CR) can be reduced by antenna selection. This paper analyzes different power adaptive transmit antenna selection (TAS) schemes for an underlay CR, which ensure that the instantaneous interference caused by the secondary transmitter to the primary receiver is below a predetermined level. We consider the optimal continuous power adaptive TAS and present a low-complexity antenna and power level selection scheme, named sequential antenna and power level selection scheme (SAPS), for discrete power adaptation. Exact statistical characterizations of the signal-to-interference plus noise ratio at the secondary receiver are derived for the considered schemes. Based on the newly derived statistics, we prove that the considered schemes achieve the highest diversity order equaling the number of antennas at the secondary transmitter. Further, we also derive a closed-form expression of the ergodic capacity for the underlay CR with SAPS scheme. Finally, we show that the proposed scheme outperforms existing schemes in terms of ergodic capacity.

Social inclusion and career development--transition from upper secondary school to work or post-secondary education among hard of hearing students.

Science.gov (United States)

Danermark, B; Antonson, S; Lundström, I

2001-01-01

The aim of this study was to investigate the decision process and to analyse the mechanisms involved in the transition from upper secondary education to post-secondary education or the labour market. Sixteen students with sensorioneural hearing loss were selected. Among these eight of the students continued to university and eight did not. Twenty-five per cent of the students were women and the average age was 28 years. The investigation was conducted about 5 years after graduation from the upper secondary school. Both quantitative and qualitative methods were used. The results showed that none of the students came from a family where any or both of the parents had a university or comparable education. The differences in choice between the two groups cannot be explained in terms of social inheritance. Our study indicates that given normal intellectual capacity the level of the hearing loss seems to have no predictive value regarding future educational performance and academic career. The conclusion is that it is of great importance that a hearing impaired pupil with normal intellectual capacity is encouraged and guided to choose an upper secondary educational programme which is orientated towards post-secondary education (instead of a narrow vocational programme). Additional to their hearing impairment and related educational problems, hard of hearing students have much more difficulty than normal hearing peers in coping with changes in intentions and goals regarding their educational career during their upper secondary education.

Transmit Antenna Selection for Underlay Cognitive Radio with Instantaneous Interference Constraint

KAUST Repository

Hanif, Muhammad

2016-03-28

Cognitive radio (CR) technology addresses the problem of spectrum under-utilization. In underlay CR mode, the secondary users are allowed to communicate provided that their transmission is not detrimental to primary user communication. Transmit antenna selection is one of the low-complexity methods to increase the capacity of wireless communication systems. In this article, we propose and analyze the performance benefit of a transmit antenna selection scheme for underlay secondary system that ensures the instantaneous interference caused by the secondary transmitter to the primary receiver is below a predetermined level. Closed-form expressions of the secondary link outage probability, higher order amount of fading, and ergodic capacity are derived for the proposed scheme. Monte-carlo simulations are also carried out to confirm various mathematical results presented in this article.

Selective determination of cyanide complexes of copper, zinc and cadmium in electrolytes by spectrophotometric titration

International Nuclear Information System (INIS)

Kuznetsov, V.V.; Korchagina, O.A.; Samorukova, O.L.

1986-01-01

Selective, sensitive and rapid method for determining Cd, Zn, Cu and their mixtures in cyanide electrolytes of galvanic bathes has been developed. Analysis is performed by means of indicator spectrophotometric titration with barium and strontium salts of cadmium cyanide complexes in organic-aqueous solvents

Needful Implements in Improving the Study and Scholastic Skills of Nigerian Secondary School Students

Science.gov (United States)

Adegoroye, Biodun-Smith; Ajagbe, Adesina Adunfe

2015-01-01

Showing concern about the consistent depreciation in expected study and scholastic behaviours among Secondary School students and the trailing failure in school test and exams and public exams, the authors gathered empirical report on the chosen variables among a randomly selected 1,200 secondary school students in JSS I, II, III, SSS I, II, III…

Radionuclide Incorporation in Secondary Crystalline Minerals Resulting from Chemical Weathering of Selected Waste Glasses: Progress Report: Task kd.5b

International Nuclear Information System (INIS)

Mattigod, Shas V.; Serne, R. Jeffrey; Legore, Virginia L.; Parker, Kent E.; Orr, Robert D.; McCready, David E.; )

2003-01-01

Experiments were conducted by Pacific Northwest National Laboratory to evaluate potential incorporation of radionuclides in secondary mineral phases that form from weathering vitrified nuclear waste glasses. These experiments were conducted as part of the Immobilized Low-Activity Waste-Performance Assessment (ILAW-PA) to generate data on radionuclide mobilization and transport in a near-field environment of disposed vitrified wastes. The results of these experiments demonstrated that radionuclide sequestration can be significantly enhanced by promoting the formation of cage structured minerals such as sodalite from weathering glasses. These results have important implications regarding radionuclide sequestration/mobilization aspects that are not currently accounted for in the ILAW PA. Additional studies are required to confirm the results and to develop an improved understanding of the mechanisms of sequestration of radionuclides into the secondary and tertiary weathering products o f the ILAW glass to help refine how contaminants are released from the near-field disposal region out into the accessible environment. Of particular interest is to determine whether the contaminants remain sequestered in the glass weathering products for hundreds to thousands of years. If the sequestration can be shown to continue for long periods, another immobilization process can be added to the PA analysis and predicted risks should be lower than past predictions

Complexometric determination of thallium(III using ethanethiol as a selective masking agent

Directory of Open Access Journals (Sweden)

Karthikeyan J.

2006-01-01

Full Text Available A simple and selective complexometric method for the determination of thallium in presence of other metal ions is proposed based on the selective masking ability of ethanethiol towards thallium(III. Thallium present in a given sample solution is first complexed with a known excess of EDTA and the surplus EDTA is titrated with standard zinc sulphate solution at pH 5-6(hexamine using xylenol orange as the indicator. A 0.3% aqueous solution of ethanethiol is then added to displace EDTA from the Tl(III-EDTA complex. The released EDTA is titrated with standard zinc sulphate solution as before. Reproducible and accurate results are obtained for 3.70 mg to 74.07 mg of Tl (III with relative error less than ? 0.44% and coefficient of variation not more than 0.27%. The interference of various ions was studied and the method was used for the analysis of thallium in its synthetic alloy mixtures and also in complexes.

SECONDARY SCHOOL STUDENTS' PERCEPTIONS AND ATTITUDES ABOUT SCIENTISTS

OpenAIRE

Muhammed Doğukan Balçın; Ayşegül Ergün

2018-01-01

This research was carried out to determine secondary school students’ perceptions and attitudes towards scientists. The study group consists of 53 fifth and sixth grade students receiving education in a state secondary school in Turkey. Convergent parallel design among mixed research methods was used during the research. Research data were collected using “Questionnaire on attitudes towards scientists” and “Draw A Scientist (DAS)” forms. Descriptive and inferential statistical methods and con...

The Global Contribution of Secondary Craters on the Icy Satellites

Science.gov (United States)

Hoogenboom, T.; Johnson, K. E.; Schenk, P.

2014-12-01

At present, surface ages of bodies in the Outer Solar System are determined only from crater size-frequency distributions (a method dependent on an understanding of the projectile populations responsible for impact craters in these planetary systems). To derive accurate ages using impact craters, the impactor population must be understood. Impact craters in the Outer Solar System can be primary, secondary or sesquinary. The contribution of secondary craters to the overall population has recently become a "topic of interest." Our objective is to better understand the contribution of dispersed secondary craters to the small crater populations, and ultimately that of small comets to the projectile flux on icy satellites in general. We measure the diameters of obvious secondary craters (determined by e.g. irregular crater shape, small size, clustering) formed by all primary craters on Ganymede for which we have sufficiently high resolution data to map secondary craters. Primary craters mapped range from approximately 40 km to 210 km. Image resolution ranges from 45 to 440 m/pixel. Bright terrain on Ganymede is our primary focus. These resurfaced terrains have relatively low crater densities and serve as a basis for characterizing secondary populations as a function of primary size on an icy body for the first time. Although focusing on Ganymede, we also investigate secondary crater size, frequency, distribution, and formation, as well as secondary crater chain formation on icy satellites throughout the Saturnian and Jovian systems principally Rhea. We compare our results to similar studies of secondary cratering on the Moon and Mercury. Using Galileo and Voyager data, we have identified approximately 3,400 secondary craters on Ganymede. In some cases, we measured crater density as a function of distance from a primary crater. Because of the limitations of the Galileo data, it is necessary to extrapolate from small data sets to the global population of secondary craters

Determination of the elemental composition of aerosol samples in the working environment of a secondary lead smelting company in Nigeria using EDXRF technique

International Nuclear Information System (INIS)

Obiajunwa, E.I.; Johnson-Fatokun, F.O.; Olaniyi, H.B.; Olowole, A.F.

2002-01-01

Energy dispersive X-ray fluorescence technique was employed to determine the concentrations of elements in aerosol samples collected in the working environment of a secondary lead smelting company in Nigeria. Sampling was done using Whatman-41 cellulose filters mounted in Negretti air samplers at 10 locations within the factory. The concentrations of eight elements (K, Ca, Ti, Mn, Fe, Cu, Zn and Pb) were determined. The TSP values ranged from 70 to 7963 μg/m 3 and the concentration of Pb was found to be between 2.98 and 538.47 μg/m 3 . The high Pb concentration is a danger signal to the health of the factory workers

Application of graphene oxide/lanthanum-modified carbon paste electrode for the selective determination of dopamine

Energy Technology Data Exchange (ETDEWEB)

Ye, Fengying; Feng, Chenqi; Fu, Ning; Wu, Huihui; Jiang, Jibo, E-mail: jibojiang0506@163.com; Han, Sheng, E-mail: hansheng654321@sina.com

2015-12-01

Highlights: • The effective surface area of the modified CPE has been expanded after self-assembly. • The GO–La composite exhibited excellent electrocatalytic activity toward DA. • The GO–La/CPE presented high selectivity, sensitivity, excellent stability and repeatability. - Abstract: A home-made carbon paste electrode (CPE) was reformed by graphene oxide (GO)/lanthanum (La) complexes, and a modified electrode, called GO–La/CPE, was fabricated for the selective determination of dopamine (DA) by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Several factors affecting the electrocatalytic performance of the modified sensor were investigated. Owning to the combination of GO and La ions, the GO–La/CPE sensor exhibited large surface area, well selectivity, good repeatability and stability in the oxidation reaction of DA. At optimal conditions, the response of the GO–La/CPE electrode for determining DA was linear in the region of 0.01–0.1 μM and 0.1–400.0 μM. The limit of detection was down to 0.32 nM (S/N = 3). In addition, this modified electrode was successfully applied to the detection of DA in real urine and serum samples by using standard adding method, showing its promising application in the electroanalysis of real samples.

Self-esteem and its associated factors among secondary school students in Klang District, Selangor.

Science.gov (United States)

Sherina, M S; Rampal, L; Loh, J W; Chan, C L; Teh, P C; Tan, P O

2008-03-01

Self-esteem is an important determinant of psychological well-being that is particularly problematic during adolescent life stage. There is a correlation between low self-esteem and other social problems among today's adolescents. This study was conducted to determine the mean self-esteem score, and to determine the association between self-esteem and age, sex, race, religion, number of siblings, ranking among siblings, family function, parental marital status and smoking among adolescents aged 12 to 20-years-old. A cross sectional study design using random cluster sampling method was done. Four out of a total of 35 secondary schools in Klang District, Selangor were selected. Respondents consisted of individual students in selected classes from the four selected schools. Data was collected using a self-administered, structured, pre-tested questionnaire and was analyzed using the SPSS version 12.0. Out of 1089 respondents, 793 completed the questionnaire (response rate 73.82%). The overall mean self-esteem score was 27.65. The mean self-esteem score for males (27.99) was slightly higher than females (27.31). The differences in the mean scores by race were statistically significant. There was a statistically significant relationship between mean self-esteem scores and sex, age, race, religion, number of siblings, smoking and family function. There was no statistically significant difference between mean self-esteem score with parental marital status and with ranking among siblings. The overall mean self-esteem score was 27.65. Self-esteem was associated with sex, age, race, religion, number of siblings, smoking and family function.

The Influence of Secondary School Education on the Success of Informatics Education in University

Directory of Open Access Journals (Sweden)

Marina Čičin-Šain

2008-10-01

Full Text Available The suppositions and dimensions of the influence of secondary school education on the quality and effects of informatics education in University are manifold. The influence of secondary school education can be perceived through two basic dimensions: 1 the general influence dimension of a specific secondary school, and 2 the dimension of the influence of computer and related classes, which students were exposed to during secondary school. The aforementioned dimensions of influence can be analyzed by defining key factors of general secondary school education, and the factors of informatics education in secondary school, which are significant for the quality and effects in higher computer science education. The defined basic and exactly measurable criteria of the influence of secondary school education on the students' informatics education in college are the criterion of the number of school years during which information science classes were taken, as well as the criterion of secondary school orientation (course, among which those students were selected, who graduated from economics secondary schools and gymnasium (comprehensive secondary schools.

On Secrecy Outage of Relay Selection in Underlay Cognitive Radio Networks over Nakagami-m Fading Channels

KAUST Repository

Lei, Hongjiang; Zhang, Huan; Ansari, Imran Shafique; Ren, Zhi; Pan, Gaofeng; Qaraqe, Khalid A.; Alouini, Mohamed-Slim

2017-01-01

In this paper, the secrecy outage performance of an underlay cognitive decode-and-forward relay network over independent but not necessarily identical distributed (i.n.i.d) Nakagami-m fading channels is investigated, in which the secondary user transmitter communicates with the secondary destination via relays, and an eavesdropper attempts to overhear the information. Based on whether the channel state information (CSI) of the wiretap links is available or not, we analyze the secrecy outage performance with optimal relay selection (ORS) and suboptimal relay selection (SRS) schemes, and multiple relays combining scheme (MRC) scheme is considered for comparison purpose. The exact and asymptotic closed-form expressions for the secrecy outage probability with three different relay selection schemes are derived and verified by Monte-Carlo simulations. The numerical results illustrate that ORS scheme always outperforms SRS and MRC schemes, and SRS scheme is better than MRC scheme in the lower fading parameters scenario. Furthermore, through asymptotic analysis, we find that these three different schemes achieve the same secrecy diversity order, which is determined by the number of the relays, and the fading parameters of the links among the relays and the destination.

On Secrecy Outage of Relay Selection in Underlay Cognitive Radio Networks over Nakagami-m Fading Channels

KAUST Repository

Lei, Hongjiang

2017-10-02

In this paper, the secrecy outage performance of an underlay cognitive decode-and-forward relay network over independent but not necessarily identical distributed (i.n.i.d) Nakagami-m fading channels is investigated, in which the secondary user transmitter communicates with the secondary destination via relays, and an eavesdropper attempts to overhear the information. Based on whether the channel state information (CSI) of the wiretap links is available or not, we analyze the secrecy outage performance with optimal relay selection (ORS) and suboptimal relay selection (SRS) schemes, and multiple relays combining scheme (MRC) scheme is considered for comparison purpose. The exact and asymptotic closed-form expressions for the secrecy outage probability with three different relay selection schemes are derived and verified by Monte-Carlo simulations. The numerical results illustrate that ORS scheme always outperforms SRS and MRC schemes, and SRS scheme is better than MRC scheme in the lower fading parameters scenario. Furthermore, through asymptotic analysis, we find that these three different schemes achieve the same secrecy diversity order, which is determined by the number of the relays, and the fading parameters of the links among the relays and the destination.

Determination of water quality of ground water in selected Payatas residential areas using ion-selective electrodes (ISE) and atomic absorption spectroscopy (AAS) (determination of NO3, Cl, Pb, Cd, Zn)

International Nuclear Information System (INIS)

Tahir, Samsudin A.; Roque, Willie P.; Arididon, Bonifacio D. Jr.; Gardon, Ruel W.

2003-01-01

This study aims to determine the water-soluble ions using ion-selective electrodes (ISE) and trace metals using atomic absorption spectroscopy (AAS). Seven water samples were chosen from the thirteen sites, which were gathered from the selected Payatas residential areas in Quezon City. For the trace metals the lowest detection of AAS in lead was obtained in La Brea site and was found to be -0.5 ppm. Lead content has a value of -0.04 ppm and was found to be below the detection limit of 0.1 ppm. The remaining sites obtained high value of lead concentrations in AAS reading. The range of concentration for lead was from 0.5 ppm for La Brea site to 1.4 ppm for Velasco site. The cadmium as trace metal in groundwater samples from Payatas residential area was found to be below the lowest limit of detection ( 3 which is 15.6 ppm and it was obtained by the used of ion selective electrodes (ISE) Horiba model type. Second to it was the La Brea site, which is 10.04 ppm All the other samples do not exceeds to the maximum allowable concentration of nitrate (50.0 ppm), and it ranged from 4.10 ppm for open-well site to 15.6 ppm for Lopez site. In chloride determination, Lagro High School obtained a reading of 57.6 ppm using ISE and it was the highest concentration amount present in seven samples. Next to it was the Ungrin site (36.8 ppm), samples ranged from 6.7 ppm for La Brea site to 57.6 ppm for Lagro high school site. All the samples do not exceeds to the maximum allowable concentration for chloride, which is 250 ppm. (Authors)

Determination of heavy metal pollution in soils from selected potentially contaminated sites in Tema

International Nuclear Information System (INIS)

Nyaaba, A.K.L.

2011-01-01

The objective of the study was to assess the concentration and determine the level of pollution by harmful heavy metals in soils from selected potentially contaminated sites in Tema. The metals of interest include; mercury, lead, cadmium, cobalt zinc, arsenic, nickel, copper and chromium. A total of forty seven (47) samples comprising thirty eight sub-samples (38) and nine (9) composite samples were collected from nine (9) different locations. These included playgrounds, steel processing factories, used Lead Acid Battery (ULAB) recycling plant, mechanic workshops and the municipal waste disposal site. The samples were prepared after which the elemental concentrations were determined using energy dispersive X-ray fluorescence (EDXRF) with a secondary target excitation arrangement (5.9 keV). The analysis of the samples yielded the following mean heavy metal concentrations in mg/kg: 424.38 (Cr); 408.68 (Ni); 14427 (Cu); 4129.87 (Zn); 1580.68 (As); 647.48 (Hg); 73361.51 (Pb) and 1176.16 (Co). The mean concentrations of heavy metals in the soils were in the following order Pb>Zn>As>Co>Cu>Hg>Cr>Ni. Mercury was detected at only two of the sites. The average heavy metals in the soils from the sites were generally high since most of them exceeded the optimum and action values of the New Dutch List. The Enrichment Factor (EF) ratios show that the enrichment of the elements in the soils ranged from deficiently to extremely highly enriched. The contamination factor show that the contamination by the heavy metals were low at some of the sites and very high at others. The geoaccumulation indices indicated that the playground (PG) has not been contaminated by any of the metals, C8 is contaminated strongly by mercury only and the contamination at the remaining sites varied from moderately contaminated to extremely contaminated by the metals. The Igeo also indicated that the elements accounting for extreme contamination are lead, arsenic, copper, zinc mercury and chromium. Lead

Challenges to Successful Total Quality Management Implementation in Public Secondary Schools: A Case Study of Kohat District, Pakistan

Science.gov (United States)

Suleman, Qaiser; Gul, Rizwana

2015-01-01

The current study explores the challenges faced by public secondary schools in successful implementation of total quality management (TQM) in Kohat District. A sample of 25 heads and 75 secondary school teachers selected from 25 public secondary schools through simple random sampling technique was used. Descriptive research designed was used and a…

Academic Procrastination of Secondary School Pupils

Directory of Open Access Journals (Sweden)

Branka Ribič Hederih

2014-06-01

Full Text Available Procrastination is a trait and/or a form of behavior that denotes an individual’s delay in an activity which should be done, and which causes discomfort. In the study we wished to determine the differences between high school students regarding gender, educational programme and learning success of the previous school year in three factors. On a sample of 284 high school students of different Slovenian secondary schools, we found that on average boys show statistically significantly more shortage of learning self-discipline than girls, while girls, on average, significantly more discomfort than boys. Comparison of secondary school students between programmes showed that, on average, gimnazija students show significantly more learning self-discipline than students in secondary technical education. The comparison in relation to different levels of learning success at the end of the previous school year and the factors of procrastination showed, however, no statistically significant differences.

Selective determination of plutonium and transplutonic elements (Am, Cm) in feces ashes

International Nuclear Information System (INIS)

Ballada, J.; Verry, M.; Daburon, M.L.; Jeanmaire, L.

1983-02-01

A technique has been developed for the selective determination of the main transplutonic elements of the fuel cycle in feces ashes. The natural elements (U, Ra, Th and their isotopes) usually present in the human diet, are eliminated. Plutonium separation is carried out in a classical way by ion exchange resin. After elimination of U and Th, Am-Cm are collected on a millipore filter for α spectrometry or global counting. Yields are 95% (σ = 4) for Pu and 81.7% (σ = 6,2) for Am-Cm [fr

An Instrument to Determine the Technological Literacy Levels of Upper Secondary School Students

Science.gov (United States)

Luckay, Melanie B.; Collier-Reed, Brandon I.

2014-01-01

In this article, an instrument for assessing upper secondary school students' levels of technological literacy is presented. The items making up the instrument emerged from a previous study that employed a phenomenographic research approach to explore students' conceptions of technology in terms of their understanding of the "nature…

Prevalence of smoking among male secondary school students in Jeddah, Saudi Arabia

OpenAIRE

Hashim R Fida; Ismail Abdelmoneim

2013-01-01

Objectives: This study was conducted to examine the prevalence of smoking and habits of smoking among male secondary school students in Jeddah, Kingdom of Saudi Arabia (KSA) and to assess their knowledge and attitudes toward it. Materials and Methods: A cross-sectional study was conducted in Jeddah, using a two-stage cluster sampling, randomly selecting 4 out of 85 government male secondary schools. Data were obtained through a self-administered questionnaire eliciting responses to questions ...

Determination of fluoride content in UO2F2 and ADUF solution by ion selective electrode

International Nuclear Information System (INIS)

Samanta, Papu; Kumar, Pradeep; Bagchi, A.C.

2017-01-01

During production of uranium metal powder, liquid solution UO 2 F 2 and ADUF containing high content of fluoride gets generated. Fluoride being corrosive in nature, fluorides concentration needs to determined. Ion selective electrode, LaF 3 (Eu) crystal, has been used. Uranium was found to interfere with fluoride analysis. Study was carried out to selectively remove uranium by solvent extraction employing D2EHPA+Cyanex 923 and TBP in dodecane. The TBP was found effective to remove uranium. (author)

Alpha spectrometry and secondary ion mass spectrometry of thorium

International Nuclear Information System (INIS)

Strisovska, Jana; Kuruc, Jozef; Galanda, Dusan; Matel, Lubomir; Velic, Dusan; Aranyosiova, Monika

2009-01-01

A sample of thorium content on steel discs was prepared by electrodeposition with a view to determining the natural thorium isotope. Thorium was determined by alpha spectrometry and by secondary ion mass spectrometry and the results of the two methods were compared

To the problem of the secondary CMB anisotropy separation

Directory of Open Access Journals (Sweden)

Verkhodanov Oleg

2016-01-01

Full Text Available We study contribution to the secondary anisotropy maps of cosmic microwave background (CMB radiation which difficult to account for faint sources. Two effects are investigated. They are the Sunyaev–Zeldovich effect connected with the inverse Compton scattering of CMB photons on hot electrons of cluster of galaxies, and contamination of the background by weak extragalctic sources. First, we study fields of the Planck CMB maps around radio sources of the RATAN-600 catalog. We see weak microwave sources which make an additional contribution to the secondary anisotropy on angular small scales (< 7′. An algorithm for selecting candidate objects with the Sunyaev–Zeldovich effect was proposed, based on the use of data on the radio spectral indices and the signal in cosmic-microwave background maps. Second, applying the stacking method, we examine the areas of the CMB maps, constructed according to the Planck Space Observatory data in the neighborhood of different populations of radio sources and giant elliptical galaxies. The samples of objects include giant radio galaxies (GRG, radio sources, selected by the radio spectral index and redshift, as well as the gammaray bursts, used as a secondary comparative sample. The signal from this objects exists on CMB maps and its difference in the neighborhood of GRGs from the other types of objects was discovered.

Cellulitis Secondary to Liquid Nitrogen Cryotherapy: Case Report and Literature Review.

Science.gov (United States)

Huang, Christina M; Lu, Emily Y; Kirchhof, Mark G

Liquid nitrogen cryotherapy is a commonly used technique to treat a wide variety of dermatologic conditions including actinic keratoses, non-melanoma skin cancers, verrucae, and seborrheic keratoses. The risks associated with liquid nitrogen cryotherapy are important to know and discuss with patients prior to treatment. We report a case of cellulitis secondary to liquid nitrogen cryotherapy for actinic keratosis. We sought to review the literature for an estimate of secondary infection rates following cryotherapy treatment. We searched Pubmed using the terms cryotherapy and infection or cellulitis. We then looked at articles classified as clinical trials where cryotherapy was used to treat skin conditions. We then selected clinical trials that listed cellulitis or infection as an adverse event. There were no case reports, case series, or review articles detailing the risk of infection from liquid nitrogen cryotherapy. We found 8 articles classified as clinical trials on Pubmed that did list infection as an adverse event. The risk of infection from these studies varied from approximately 2% to 30%. There was a great degree of heterogeneity in treatment sites, length of treatment, and treatment targets. While it is difficult to determine the true incidence of infection from liquid nitrogen cryotherapy, clinicians should endeavor to inform patients of this potential risk.

Tuning excitation laser wavelength for secondary resonance in low-intensity phase-selective laser-induced breakdown spectroscopy for in-situ analytical measurement of nanoaerosols

Science.gov (United States)

Xiong, Gang; Li, Shuiqing; Tse, Stephen D.

2018-02-01

In recent years, a novel low-intensity phase-selective laser-induced breakdown spectroscopy (PS-LIBS) technique has been developed for unique elemental-composition identification of aerosolized nanoparticles, where only the solid-phase nanoparticles break down, forming nanoplasmas, without any surrounding gas-phase breakdown. Additional work has demonstrated that PS-LIBS emissions can be greatly enhanced with secondary resonant excitation by matching the excitation laser wavelength with an atomic transition line in the formed nanoplasma, thereby achieving low limits of detection. In this work, a tunable dye laser is employed to investigate the effects of excitation wavelength and irradiance on in-situ PS-LIBS measurements of TiO2 nanoaerosols. The enhancement factor by resonant excitation can be 220 times greater than that for non-resonant cases under similar conditions. Moreover, the emitted spectra are unique for the selected resonant transition lines for a given element, suggesting the potential to make precise phase-selective and analyte-selective measurements of nanoparticles in a multicomponent multiphase system. The enhancement factor by resonant excitation is highly sensitive to excitation laser wavelength, with narrow excitation spectral windows, i.e., 0.012 to 0.023 nm (FWHM, full width at half maximum) for Ti (I) neutral atomic lines, and 0.051 to 0.139 nm (FWHM) for Ti (II) single-ionized atomic lines. Boltzmann analysis of the emission intensities, temporal response of emissions, and emission dependence on excitation irradiance are investigated to understand aspects of the generated nanoplasmas such as temperature, local thermodynamic equilibrium (LTE), and excitation mechanism.

Optimisation or satiation, testing diet selection rules in goats

NARCIS (Netherlands)

Jansen, D.A.W.A.M.; Langevelde, van F.; Boer, de W.F.; Kirkman, K.P.

2007-01-01

Several hypotheses have been formulated to explain diet selection by herbivores, focusing on the maximization of nutrient intake, the minimization of plant secondary compounds, or the satiety hypothesis. This research aimed at studying diet selection revealing which chemical characteristics of

U(VI) complexation with selected flavonoids investigated by absorption and emission spectroscopy at light acidic conditions

Energy Technology Data Exchange (ETDEWEB)

Guenther, Alix; Geipel, Gerhard [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Biogeochemistry

2017-06-01

Flavonoids are secondary plant compounds and have important properties. Beside their antioxidant activity and effects as enzyme inhibitors, they can bind metals ions. The possible release of flavonoids from the root into the soil can affect the migration of radionuclides in the biological and geological environment. In this work, the complexation behavior of selected flavonols and a flavonol glycoside towards U(VI) were spectroscopically investigated and the corresponding complex stability constants were determined.

U(VI) complexation with selected flavonoids investigated by absorption and emission spectroscopy at light acidic conditions

International Nuclear Information System (INIS)

Guenther, Alix; Geipel, Gerhard

2017-01-01

Flavonoids are secondary plant compounds and have important properties. Beside their antioxidant activity and effects as enzyme inhibitors, they can bind metals ions. The possible release of flavonoids from the root into the soil can affect the migration of radionuclides in the biological and geological environment. In this work, the complexation behavior of selected flavonols and a flavonol glycoside towards U(VI) were spectroscopically investigated and the corresponding complex stability constants were determined.

Extended Delivery Time Analysis for Cognitive Packet Transmission With Application to Secondary Queuing Analysis

KAUST Repository

Usman, Muneer

2015-05-21

Cognitive radio transceiver can opportunistically access the underutilized spectrum resource of primary systems for new wireless services. With interweave implementation, the secondary transmission may be interrupted by the primary user\\'s transmission. To facilitate the delay analysis of such secondary transmission for fixed-size secondary packets, we study the resulting extended delivery time that includes both transmission time and waiting time. In particular, we derive the exact distribution functions of extended delivery time of secondary transmission for both continuous sensing and periodic sensing cases. Selected numerical and simulation results are presented for illustrating the mathematical formulation. Finally, we consider an M/G/1 queueing set-up at the secondary transmitter and formulate the closed-form expressions for the expected delay with Poisson traffic. The analytical results will greatly facilitate the design of the secondary system for particular target application. © 2015 IEEE.

Select early type IA endoleaks after endovascular aneurysm repair will resolve without secondary intervention.

Science.gov (United States)

O'Donnell, Thomas F X; Corey, Michael R; Deery, Sarah E; Tsougranis, Gregory; Maruthi, Rohit; Clouse, W Darrin; Cambria, Richard P; Conrad, Mark F

2018-01-01

). Both an increase in aneurysm sac size and failure of the endoleak to resolve by case end were independent predictors of a need for reintervention (growth: OR, 8.3; 95% CI, 2.2-31.6; P IA endoleak was not independently associated with an increase in sac size on surveillance imaging (P = .28). Aneurysm rupture secondary to persistent type IA endoleak is rare, and most will resolve within 1 year. Extensive neck calcification is the only independent predictor of persistent type IA endoleak, and an increase in sac size warrants reintervention. These data suggest that select early persistent type IA endoleaks can be safely observed. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Electrochemical sensor based on a carbon nanotube-modified imprinted sol–gel for selective and sensitive determination of β2-agonists

International Nuclear Information System (INIS)

Xu, Wei; Liu, Ping; Guo, Chunhui; Dong, Chao; Zhang, Xiuhua; Wang, Shengfu

2013-01-01

We describe a molecularly imprinted electrochemical sensor for selective and sensitive determination of β2-agonists. It is making use of a combination of single-wall carbon nanotubes (SWNTs) with a molecularly imprinted sol–gel. The SWNTs were introduced in order to enhance electron transport and sensitivity. The imprinted sol–gel film with its specific binding sites acts as a selective recognition element and as a preconcentrator for β 2 -agonists. The morphology of the imprinted film was characterized by scanning electron microscopy. The optimized sensor displays high sensitivity and excellent selectivity for the β 2 -agonists as shown for their determination in human serum samples. (author)

Treatment of secondary burn wound progression in contact burns-a systematic review of experimental approaches.

Science.gov (United States)

Schmauss, Daniel; Rezaeian, Farid; Finck, Tom; Machens, Hans-Guenther; Wettstein, Reto; Harder, Yves

2015-01-01

After a burn injury, superficial partial-thickness burn wounds may progress to deep partial-thickness or full-thickness burn wounds, if kept untreated. This phenomenon is called secondary burn wound progression or conversion. Burn wound depth is an important determinant of patient morbidity and mortality. Therefore, reduction or even the prevention of secondary burn wound progression is one goal of the acute care of burned patients. The objective of this study was to review preclinical approaches evaluating therapies to reduce burn wound progression. A systematic review of experimental approaches in animals that aim at reducing or preventing secondary burn wound progression was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta Analysis (PRISMA) guidelines. The selected references consist of all the peer-reviewed studies performed in vivo in animals and review articles published in English, German, Italian, Spanish, or French language relevant to the topic of secondary burn wound progression. We searched MEDLINE, Cochrane Library, and Google Scholar including all the articles published from the beginning of notations to the present. The search was conducted between May 3, 2012 and December 26, 2013. We included 29 experimental studies in this review, investigating agents that maintain or increase local perfusion conditions, as well as agents that exhibit an anti-coagulatory, an anti-inflammatory, or an anti-apoptotic property. Warm water, simvastatin, EPO, or cerium nitrate may represent particularly promising approaches for the translation into clinical use in the near future. This review demonstrates promising experimental approaches that might reduce secondary burn wound progression. Nevertheless, a translation into clinical application needs to confirm the results compiled in experimental animal studies.

Consequences of Secondary Calibrations on Divergence Time Estimates.

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John J Schenk

Full Text Available Secondary calibrations (calibrations based on the results of previous molecular dating studies are commonly applied in divergence time analyses in groups that lack fossil data; however, the consequences of applying secondary calibrations in a relaxed-clock approach are not fully understood. I tested whether applying the posterior estimate from a primary study as a prior distribution in a secondary study results in consistent age and uncertainty estimates. I compared age estimates from simulations with 100 randomly replicated secondary trees. On average, the 95% credible intervals of node ages for secondary estimates were significantly younger and narrower than primary estimates. The primary and secondary age estimates were significantly different in 97% of the replicates after Bonferroni corrections. Greater error in magnitude was associated with deeper than shallower nodes, but the opposite was found when standardized by median node age, and a significant positive relationship was determined between the number of tips/age of secondary trees and the total amount of error. When two secondary calibrated nodes were analyzed, estimates remained significantly different, and although the minimum and median estimates were associated with less error, maximum age estimates and credible interval widths had greater error. The shape of the prior also influenced error, in which applying a normal, rather than uniform, prior distribution resulted in greater error. Secondary calibrations, in summary, lead to a false impression of precision and the distribution of age estimates shift away from those that would be inferred by the primary analysis. These results suggest that secondary calibrations should not be applied as the only source of calibration in divergence time analyses that test time-dependent hypotheses until the additional error associated with secondary calibrations is more properly modeled to take into account increased uncertainty in age estimates.

Knowledge and attitude of secondary school teachers in Enugu to school based sex education.

Science.gov (United States)

Aniebue, P N

2007-12-01

To assess the knowledge and attitude to sex education among secondary school teachers in Enugu. A cross sectional study of 300 teachers drawn from nine randomly selected secondary schools in Enugu metropolis was carried out. Pre-tested self administered structured questionnaire was used as instrument for data collection. Three hundred teachers, 215 females and 85 males were interviewed. The mean age of the teachers was 38.1+/-7.5 years. Sixty-nine (23.0%) had adequate knowledge of sex education and 282 (94.0%) approved the inclusion of sex education into the school curriculum. The commonest reason for disapproval of sex education was fear that it would lead to promiscuity amongst the students. Educational status and marital status of the teachers were significant determinants of positive attitude to sex education psex education according to the teachers is 11-15 years. Two hundred and thirty eight (79.3%) respondents were of the opinion that teachers needed to be trained to provide sex education to students and 244 (81.3%) admitted that sex education was not in the school curriculum. Secondary school teachers are in support of provision of sex education to students. However they need training and skills on how to present sex information in a positive manner to achieve the desired goal. There is need to include sex education in the school curriculum.

An empirical study of stressors that impinge on teachers in secondary schools in Swaziland

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C I O Okeke

2013-01-01

Full Text Available This study employed the descriptive-correlation research design to determine whether secondary school teachers experience work-related stress. Participants included 239 teachers selected from schools in the Hhohho region of Swaziland. A questionnaire was used as the instrument to determine the level ofwork-related stress experienced by these teachers. Findings showed that teachers were moderately stressed by their work. Contractual problems and the nature of their work were two aspects that were reported to be the main stressors for the sample, while the work environment and work relationships were only mildly stressful. There was a weak relationship between the level of work-related stress and the demographic variables of gender, marital status, and qualifications. Age had a moderate significant relationship with the level of work-related stress for the sample. The study recommends that stress management programmes for teachers are imperative to deal with the consequences of stress.

Detection of the Secondary Eclipse of Exoplanet HAT P-11b

Science.gov (United States)

Barry, R. K.; Deming, L. D.; Bakos, G.; Harrington, J.; Madhusudhan, N.; Noyes, R.; Seager, S.

2010-01-01

We have successfully conducted secondary eclipse observations of exoplanet HAT-P-11b using the Spitzer Space Telescope. HAT-P-11b was, until very recently, the smallest transiting extrasolar planet yet found and one of only two known exo-Neptunes. We observed the system at 3.6 microns for a period of 22 hours centered on the anticipated secondary eclipse time, to detect the eclipse and determine its phase. Having detected the secondary eclipse, we are at present making a more focused series of observations in both the 3.6 and 4.5 micron bands to fully characterize it. HAT-P-11b has a period of 4.8878 days, radius of 0.422 RJ, mass of 0.081 MJ and semi-major axis 0.053 AU. Measurements of the secondary eclipse will serve to clarify two key issues; 1) the planetary brightness temperature and the nature of its atmosphere, and 2) the eccentricity of its orbit, with implications for its dynamical evolution. A precise determination of the orbit phase for the secondary eclipse will also be of great utility for Kepler observations of this system at visible wavelengths.

Development of protein biomarkers in cerebrospinal fluid for secondary progressive multiple sclerosis using selected reaction monitoring mass spectrometry (SRM-MS

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Jia Yan

2012-07-01

Full Text Available Abstract Background Multiple sclerosis (MS is a chronic inflammatory disorder of the central nervous system (CNS. It involves damage to the myelin sheath surrounding axons and to the axons themselves. MS most often presents with a series of relapses and remissions but then evolves over a variable period of time into a slowly progressive form of neurological dysfunction termed secondary progressive MS (SPMS. The reasons for this change in clinical presentation are unclear. The absence of a diagnostic marker means that there is a lag time of several years before the diagnosis of SPMS can be established. At the same time, understanding the mechanisms that underlie SPMS is critical to the development of rational therapies for this untreatable stage of the disease. Results Using high performance liquid chromatography-coupled mass spectrometry (HPLC; we have established a highly specific and sensitive selected reaction monitoring (SRM assay. Our multiplexed SRM assay has facilitated the simultaneous detection of surrogate peptides originating from 26 proteins present in cerebrospinal fluid (CSF. Protein levels in CSF were generally ~200-fold lower than that in human sera. A limit of detection (LOD was determined to be as low as one femtomol. We processed and analysed CSF samples from a total of 22 patients with SPMS, 7 patients with SPMS treated with lamotrigine, 12 patients with non-inflammatory neurological disorders (NIND and 10 healthy controls (HC for the levels of these 26 selected potential protein biomarkers. Our SRM data found one protein showing significant difference between SPMS and HC, three proteins differing between SPMS and NIND, two proteins between NIND and HC, and 11 protein biomarkers showing significant difference between a lamotrigine-treated and untreated SPMS group. Principal component analysis (PCA revealed that these 26 proteins were correlated, and could be represented by four principal components. Overall, we established an

Isolating E.Coli Bacteriophage from Raw Sewage and Determining its Selectivity to the Host Cell

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SM Imeni

2016-05-01

Full Text Available Introduction: Bacteriophages are viruses that infect and destroy prokaryote cells, specifically the bacteria. They act too selective, so as each bacteriophage affects only on specific type of bacteria. Due to their specific features, bacteriophages can be used as an appropriate substitute for antibiotics in infectious diseases treatment. Therefore, this study aimed to isolate E. coli-specific bacteriophage from raw sewage. Methods: Eight samples of raw sewage, each containing approximately 50 ml of raw sewage with 10 minute gap, were prepared from Zargandeh wastewater treatment plant, Tehran, Iran. The sewages were mixed with Brain-heart infusion medium (BHI as a liquid culture medium in order to let the microorganisms grow. Incubation, purification and determination of bacteria were followed repeatedly to isolate the bacteriophage. Then it was tested on E.coli (ATCC 25922, Enterococcus faecalis (ATCC 19433, Staphylococcus aureus (ATCC 2392, and Yersinia enterocolitica (ATCC 9610 in order to determine the bacteriophage selectivity. Results: The E.coli bacteriophages were successfully isolated from all the eight samples, that were completely able to lyse and destroy E.coli bacterial cells, though no effect was observed on other types of bacteria. Conclusion: The study findings revealed that bacteriophages act selectively. Considering the raise of antibiotic resistance in the world, bacteriophages can serve as a good substitute for antibiotics in treating infectious diseases.

Principals' Management of Conflicts in Public Secondary Schools in Ondo State, Nigeria: A Critical Survey

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Adeyemi, T. O.

2009-01-01

This paper examined principals' management of conflicts in public secondary schools in Ondo State, Nigeria. As a descriptive survey, the study population comprised all the 281 public secondary schools in the State. Out of this population, a sample of 80 schools was drawn while 340 respondents (80 principals and 260 teachers) were selected through…

Inequalities in selected health-related Millennium Development ...

African Journals Online (AJOL)

Inequalities in selected health-related Millennium Development Goals ... and interventions (including health promotion, primary and secondary prevention, ... and ensuring environmental sustainability (through reduction in the use of solid fuels ...

Pure zinc sulfide quantum dot as highly selective luminescent probe for determination of hazardous cyanide ion

Energy Technology Data Exchange (ETDEWEB)

Shamsipur, Mojtaba, E-mail: mshamsipur@yahoo.com [Department of Chemistry, Razi University, Kermanshah (Iran, Islamic Republic of); Rajabi, Hamid Reza, E-mail: h.rajabi@mail.yu.ac.ir [Chemistry Department, Yasouj University, Yasouj 75918-74831 (Iran, Islamic Republic of)

2014-03-01

A rapid and simple fluorescence method is presented for selective and sensitive determination of hazardous cyanide ion in aqueous solution based on functionalized zinc sulfide (ZnS) quantum dot (QD) as luminescent prob. The ultra-small ZnS QDs were synthesized using a chemical co-precipitation method in the presence of 2-mercaptoethanol (ME) as an efficient capping agent. The prepared pure ZnS QDs was applied as an optical sensor for determination of cyanide ions in aqueous solutions. ZnS nanoparticles have exhibited a strong fluorescent emission at about 424 nm. The fluorescence intensity of QDs is linearly proportional to the cyanide ion concentration in the range 2.44 × 10{sup −6} to 2.59 × 10{sup −5} M with a detection limit of 1.70 × 10{sup −7} M at pH 11. The designed fluorescent sensor possesses remarkable selectivity for cyanide ion over other anions such as Cl{sup −}, Br{sup −}, F{sup −}, I{sup −}, IO{sub 3}{sup −}, ClO{sub 4}{sup −}, BrO{sub 3}{sup −}, CO{sub 3}{sup 2−}, NO{sub 2}{sup −}, NO{sub 3}{sup −}, SO{sub 4}{sup 2−}, S{sub 2}O{sub 4}{sup 2−}, C{sub 2}O{sub 4}{sup 2−}, SCN{sup −}, N{sub 3}{sup −}, citrate and tartarate with negligible influences on the cyanide detection by fluorescence spectroscopy. - Highlights: • Preparation of functionalized ZnS quantum dots in aqueous media • Highly selective quantum dot based luminescent probe for determination of cyanide • Fast and sensitive determination of hazardous CN{sup −} by fluorescence quenching.

Characterization of Angiotensin II Molecular Determinants Involved in AT1 Receptor Functional Selectivity.

Science.gov (United States)

Domazet, Ivana; Holleran, Brian J; Richard, Alexandra; Vandenberghe, Camille; Lavigne, Pierre; Escher, Emanuel; Leduc, Richard; Guillemette, Gaétan

2015-06-01

The octapeptide angiotensin II (AngII) exerts a variety of cardiovascular effects through the activation of the AngII type 1 receptor (AT1), a G protein-coupled receptor. The AT1 receptor engages and activates several signaling pathways, including heterotrimeric G proteins Gq and G12, as well as the extracellular signal-regulated kinases (ERK) 1/2 pathway. Additionally, following stimulation, βarrestin is recruited to the AT1 receptor, leading to receptor desensitization. It is increasingly recognized that specific ligands selectively bind and favor the activation of some signaling pathways over others, a concept termed ligand bias or functional selectivity. A better understanding of the molecular basis of functional selectivity may lead to the development of better therapeutics with fewer adverse effects. In the present study, we developed assays allowing the measurement of six different signaling modalities of the AT1 receptor. Using a series of AngII peptide analogs that were modified in positions 1, 4, and 8, we sought to better characterize the molecular determinants of AngII that underlie functional selectivity of the AT1 receptor in human embryonic kidney 293 cells. The results reveal that position 1 of AngII does not confer functional selectivity, whereas position 4 confers a bias toward ERK signaling over Gq signaling, and position 8 confers a bias toward βarrestin recruitment over ERK activation and Gq signaling. Interestingly, the analogs modified in position 8 were also partial agonists of the protein kinase C (PKC)-dependent ERK pathway via atypical PKC isoforms PKCζ and PKCι. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

Attitude of Students towards Cooperative Learning in Some Selected Secondary Schools in Nasarawa State

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Amedu, Odagboyi Isaiah; Gudi, Kreni Comfort

2017-01-01

This study is aimed at investigating the attitude of students toward the cooperative learning approach. A quasiexperimental design was used for the study. The sample was made of 179 SS 1 students drawn from three public secondary schools in Nasarawa state. The Jigsaw Attitude Questionnaire (JAQ) was adapted from Koprowski and Perigo (2000) and was…

Current and desired competency levels of secondary agricultural teachers in Pennsylvania

Science.gov (United States)

Elbert, Chanda Dehron

The purpose of this study was to identify the competencies needed by secondary agricultural teachers in the Commonwealth of Pennsylvania. Specifically, this study identified competencies needed to help make teachers more effective while working with special needs students. The objectives of the study were to: (1) determine, verify, and evaluate competencies needed by secondary teachers of agriculture to work with handicapped students enrolled in agricultural and vocational education programs; (2) determine, verify, and evaluate competencies needed by secondary teachers of agriculture to work with economically disadvantaged students enrolled in agricultural and vocational education programs; (3) determine, verify, and evaluate competencies needed by secondary teachers of agriculture to work with academically challenged students enrolled in agricultural and vocational programs; and (4) evaluate the self-perceived competency levels of secondary agricultural education teachers and their desired competency levels. A 50% simple random sample of secondary agricultural teachers from the Directory for Agricultural Education in Pennsylvania, 1999--2000 was used. The design for the study was a descriptive study. The data collection instrument used was divided into five different areas: personal characteristics, professional role and development, instructional role, knowledge statements, and student leadership and organization. Subjects were asked to rate their present and desired levels of competency in the categories using a Likert-type scale. The competency scale was as follows: 1 = not competent; 2 = slightly competent, 3 = competent; 4 = very competent; 5 = extremely competent. There were 153 questionnaires mailed to the secondary agricultural education teachers. A total of 96 teachers responded to the questionnaire. Frequencies and distributions were used to describe demographic variables. T-test and analysis of variance were used to determine relationships between

Strong eukaryotic IRESs have weak secondary structure.

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Xuhua Xia

Full Text Available BACKGROUND: The objective of this work was to investigate the hypothesis that eukaryotic Internal Ribosome Entry Sites (IRES lack secondary structure and to examine the generality of the hypothesis. METHODOLOGY/PRINCIPAL FINDINGS: IRESs of the yeast and the fruit fly are located in the 5'UTR immediately upstream of the initiation codon. The minimum folding energy (MFE of 60 nt RNA segments immediately upstream of the initiation codons was calculated as a proxy of secondary structure stability. MFE of the reverse complements of these 60 nt segments was also calculated. The relationship between MFE and empirically determined IRES activity was investigated to test the hypothesis that strong IRES activity is associated with weak secondary structure. We show that IRES activity in the yeast and the fruit fly correlates strongly with the structural stability, with highest IRES activity found in RNA segments that exhibit the weakest secondary structure. CONCLUSIONS: We found that a subset of eukaryotic IRESs exhibits very low secondary structure in the 5'-UTR sequences immediately upstream of the initiation codon. The consistency in results between the yeast and the fruit fly suggests a possible shared mechanism of cap-independent translation initiation that relies on an unstructured RNA segment.

Patients' perspectives on the medical primary-secondary care interface: systematic review and synthesis of qualitative research.

Science.gov (United States)

Sampson, Rod; Cooper, Jamie; Barbour, Rosaline; Polson, Rob; Wilson, Philip

2015-10-15

To synthesise the published literature on the patient experience of the medical primary-secondary care interface and to determine priorities for future work in this field aimed at improving clinical outcomes. Systematic review and metaethnographic synthesis of primary studies that used qualitative methods to explore patients' perspectives of the medical primary-secondary care interface. International primary-secondary care interface. EMBASE, MEDLINE, CINAHL Plus with Full text, PsycINFO, Psychology and Behavioural Sciences Collection, Health Business Elite, Biomedica Reference Collection: Comprehensive Library, Information Science & Technology Abstracts, eBook Collection, Web of Science Core Collection: Citation Indexes and Social Sciences Citation Index, and grey literature. Studies were eligible for inclusion if they were full research papers employing qualitative methodology to explore patients' perspectives of the medical primary-secondary care interface. The 7-step metaethnographic approach described by Noblit and Hare, which involves cross-interpretation between studies while preserving the context of the primary data. The search identified 690 articles, of which 39 were selected for full-text review. 20 articles were included in the systematic review that encompassed a total of 689 patients from 10 countries. 4 important areas specific to the primary-secondary care interface from the patients' perspective emerged: barriers to care, communication, coordination, and 'relationships and personal value'. Patients should be the focus of any transfer of care between primary and secondary systems. From their perspective, areas for improvement may be classified into four domains that should usefully guide future work aimed at improving quality at this important interface. PROSPERO CRD42014009486. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

A thresholding-based antenna switching in MIMO cognitive radio networks with SWIPT-enabled secondary receiver

KAUST Repository

Benkhelifa, Fatma

2017-07-31

Simultaneous wireless power and information transfer (SWIPT) in a cognitive radio (CR) network is considered where a multiple antenna energy harvesting (EH) secondary receiver (SR) harvests the energy using the antenna switching (AS) technique. In fact, the AS technique selects a subset of the SR antennas to decode the information (namely the information decoding (ID) antennas) and the rest to harvest the energy (namely the EH antennas). In this context, we propose a thresholding-based antenna selection strategy, termed as the prioritizing data selection (PDS) scheme, which selects the ID antennas such that the received power from the secondary transmitter (ST) at these antennas is above a certain threshold. For this scheme, we derive the analytic expressions of the probability mass function (PMF) of the selected ID antennas, the average harvested energy, and the outage probability. In the simulation results, we illustrate the performance of the PDS scheme and we compare it to the prioritizing energy selection (PES) scheme which selects the EH antennas such that the received power from ST at these antennas is above a certain threshold. For both schemes, we show that there is a tradeoff between the outage probability and the average harvested energy.

Are P.T.H. plasma levels useful for the selection of patients with secondary hyperparathyroidism for preoperative MIBI (99mTc)/123I dual-isotope scintigraphy?

International Nuclear Information System (INIS)

Balogova, S.; Sauer, A.M.; Dudczak, J.; Pascal, O.; Kerrou, K.; Huchet, V.; Montravers, F.; Talbot, J.N.; Perie, S.; Lacau St-Guily, J.; Nataf, V.; Balogova, S.

2010-01-01

The utility of preoperative scintigraphy in case of secondary hyperparathyroidism is questioned by some authors. Obviously, an imaging modality that will detect all hyperplastic glands, including the ectopic ones, would be of interest in those patients at high risk for surgery. However, scintigraphy has a limited detection rate in some patients. We investigated whether one of the following parameters would identify a subgroup of patients in whom the detection rate would be optimal: age, gender, hemodialysis and duration since its onset, and plasma levels of parathyrin (P.T.H.). Methods: Retrospective series of 38 patients referred for preoperative parathyroid scintigraphy due to secondary hyperparathyroidism who then underwent para thyroidectomy. Scintigraphy was performed 20 min and then 3 h after injection of 8 MBq/kg of sestamibi ( 99m Tc) with a previous ingestion of 0.1 MBq/kg iodine-123, 3 h before. Result: No significant correlation was observed between the number of glands detected on scintigraphy (and confirmed by postoperative histology) and plasma P.T.H. levels (r = -0.17). A weak positive correlation (r = +0.34) was noted in the group of six non-hemo dialysed patients. No significant relationship between this number of detected glands and a clinical parameter was observed. Conclusion: In our experience, these parameters do not permit to select, among patients with secondary hyperparathyroidism and scheduled for para thyroidectomy, those who will better benefit from parathyroid scintigraphy. (authors)

Potential and costs of electrolytical hydrogen production by secondary energy in Brazil

International Nuclear Information System (INIS)

Souza, S. N. M. de; Silva, E. P. da

1998-01-01

This paper makes a description of the availability supply secondary hydroelectric power (secondary energy) in the Brazilian interconnected hydroelectric systems, then with the data attained it is made an estimation of electrolytical hydrogen that can be produced by means of Brazilian secondary hydroelectric power. Also are determined the costs of electrolytical hydrogen production, by way of utilisation of the secondary hydroelectric power availability in the hydroelectric system of the South and Southeastern regions, with the variation of hydrogen plant capacity that allow identify the cases where hydrogen can be produced at a lower costs. (author)

Interference-aware random beam selection schemes for spectrum sharing systems

KAUST Repository

Abdallah, Mohamed

2012-10-19

Spectrum sharing systems have been recently introduced to alleviate the problem of spectrum scarcity by allowing secondary unlicensed networks to share the spectrum with primary licensed networks under acceptable interference levels to the primary users. In this work, we develop interference-aware random beam selection schemes that provide enhanced performance for the secondary network under the condition that the interference observed by the receivers of the primary network is below a predetermined/acceptable value. We consider a secondary link composed of a transmitter equipped with multiple antennas and a single-antenna receiver sharing the same spectrum with a primary link composed of a single-antenna transmitter and a single-antenna receiver. The proposed schemes select a beam, among a set of power-optimized random beams, that maximizes the signal-to-interference-plus-noise ratio (SINR) of the secondary link while satisfying the primary interference constraint for different levels of feedback information describing the interference level at the primary receiver. For the proposed schemes, we develop a statistical analysis for the SINR statistics as well as the capacity and bit error rate (BER) of the secondary link.

Athletic Trainer Services in US Private Secondary Schools.

Science.gov (United States)

Pike, Alicia; Pryor, Riana R; Mazerolle, Stephanie M; Stearns, Rebecca L; Casa, Douglas J

2016-09-01

Availability of athletic trainer (AT) services in US secondary schools has recently been reported to be as high as 70%, but this only describes the public sector. The extent of AT coverage in private secondary school settings has yet to be investigated and may differ from the public secondary school setting for several reasons, including differences in funding sources. To determine the level of AT services in US private secondary schools and identify the reasons why some schools did not employ ATs. Concurrent mixed-methods study. Private secondary schools in the United States. Of 5414 private secondary schools, 2044 (38%) responded to the survey. School administrators responded to the survey via telephone or e-mail. This instrument was previously used in a study examining AT services among public secondary schools. Descriptive statistics provided national data. Open-ended questions were evaluated through content analysis. Of the 2044 schools that responded, 58% (1176/2044) offered AT services, including 28% (574/2040) full time, 25% (501/2042) part time, 4% (78/1918) per diem, and 20% (409/2042) from a hospital or clinic. A total of 84% (281 285/336 165) of athletes had access to AT services. Larger private secondary schools were more likely to have AT services available. Barriers to providing AT services in the private sector were budgetary constraints, school size and sports, and lack of awareness of the role of an AT. More than half of the surveyed private secondary schools in the United States had AT services available; however, only 28% had a full-time AT. This demonstrates the need for increased medical coverage to provide athletes in this setting the appropriate level of care. Budgetary concerns, size of the school and sport offerings, and lack of awareness of the role of the AT continued to be barriers in the secondary school setting.

Investigation of Secondary Craters in the Saturnian System

Science.gov (United States)

Hoogenboom, T.; Schenk, P.; White, O. L.

2012-03-01

To derive accurate ages using impact craters, the impact source must be determined. We investigate secondary crater size, frequency, distribution, formation, and crater chain formation on icy satellites throughout the Jupiter and Saturn systems.

Government, Coercive Power and the Perceived Legitimacy of Canadian Post-Secondary Institutions

Science.gov (United States)

McQuarrie, Fiona A. E.; Kondra, Alex Z.; Lamertz, Kai

2013-01-01

Governments regulate and control organizations, yet their role in determining organizational legitimacy is largely unexamined. In the changing Canadian post-secondary landscape, legitimacy is an increasingly important issue for post-secondary institutions as they compete amongst themselves for access to ever-shrinking resources. Using an…

Secondary electron emission from 0.5--2.5-MeV protons and deuterons

International Nuclear Information System (INIS)

Thornton, T.A.; Anno, J.N.

1977-01-01

Measurement of the secondary electron currents leaving Al, V, Fe, 316 stainless steel, Nb, and Mo foils undergoing 0.5--2.5-MeV proton and deuteron bombardment were made to determine the secondary electron emission ratios for these ions. The measured secondary electron yields were of the order of 1.0, with the deuterons producing generally higher yields than the protons

Treatment duration of topics in senior secondary school core ...

African Journals Online (AJOL)

The purpose of the study was to investigate whether the intended time of 160 minutes per week for 96 weeks was adequate for the treatment of the SSS Core Mathematics. The study used simple random sampling method to select two mixed, two single-sex female and two single-sex male Senior Secondary Schools in the ...

Secondary harm mitigation: A more humanitarian framework for international drug law enforcement.

Science.gov (United States)

Blaustein, Jarrett; McLay, Miki; McCulloch, Jude

2017-08-01

This article introduces the concept of 'secondary harm mitigation' as a framework for improving the humanitarian credentials of international drug law enforcement agencies. The concept is rooted in a critical analysis of the compatibility of the harm reduction philosophy with Australia's international drug law enforcement practices. On a utilitarian level, the net benefits of international drug law enforcement are determined to be, at best inconclusive, arguably counterproductive and in most cases, incalculable. On a humanitarian level, international drug law enforcement is also determined to be problematic from a criminological standpoint because it generates secondary harms and it is indifferent to the vulnerability of individuals who participate in illicit drug trafficking. Accordingly, the article concludes that a philosophy of harm reduction grounded in the public health perspective is inadequate for mitigating secondary harms arising from Australia's efforts to combat international illicit drug trafficking. A tentative list of secondary harm mitigation principles is presented and the article argues that secondary harm mitigation should replace supply reduction as a core tenet of Australia's National Drug Strategy. The article also concludes that secondary harm mitigation may provide a viable framework for stimulating a productive dialogue between those who advocate prohibition and those who call for decriminalisation at the global level. Copyright © 2017 Elsevier B.V. All rights reserved.

Post-Secondary Education and Rural-Urban Migration

Science.gov (United States)

Synge, J.

1974-01-01

This study examined education and career plans of Scottish rural youth who entered post-secondary education in order to determine the extent to which the educational system offers rural youth not only specific training but only entry to the urban labour market. (Author/RK)

Chemical composition, secondary metabolites, in vitro gas ...

African Journals Online (AJOL)

Chemical composition, secondary metabolites, in vitro gas production characteristics and acceptability study of some forage for ruminant feeding in South-Western Nigeria. ... Chemical composition and qualitative analysis of saponins, phenol and steroids of the plants were determined. In vitro gas production (IVGP) was ...

THE ORTHOGRAPHIC NORM IN SECONDARY SCHOOL STUDENTS’ WRITTEN ASSIGNMENTS

Directory of Open Access Journals (Sweden)

Ivana Đorđev

2016-06-01

Full Text Available This paper presents the results of research conducted with the primary objective to determine in which areas secondary school students usually make orthographic mistakes when writing (official written assignments. Starting from the hypothesis that the punctuation writing of whole and split words are areas in which secondary school students (regardless of age and school orientation achieved the weakest achievements an (exploratory research was conducted on a corpus of 3,135 written assignments written in the school year of 2010/11. The research sample was intentional, descriptive and analytical methods were used for the description and the analysis of the results. The results showed the following (1 secondary school students usually make mistakes in punctuation of written assignments - we recorded 4,487 errors in the use of signs to denote intonation and meaning of a text (errors of this type make 53.93% of the total number of spelling errors reported in the corpus of research; by frequency of errors the second are errors related to writing whole and split words (11.02%, the third error is in the use of the capital letter (9.34%; (2 most problems in orthography have second grade students, quantum of mistakes is almost the same with first graders and seniors, but in all grades the most frequent errors are in punctuation, writing of whole and split words and the use of capital letters; (3 Although school orientation affects the spelling skills of pupils, the weakest orthographic achievements are also recorded in punctuation, writing of whole and split words and capitalization, so those are areas that need to be thoroughly addressed in teaching and methodology literature. The results are, on the one hand, a picture of the current status of teaching orthography and grammar knowledge of secondary school students. On the other hand, the research results can be applied in all phases of methodical practical work in teaching orthography, the upgrading the

Transmit Antenna Selection for Multi-User Underlay Cognitive Transmission with Zero-Forcing Beamforming

KAUST Repository

Hanif, Muhammad; Yang, Hong-Chuan; Alouini, Mohamed-Slim

2017-01-01

We present a transmit antenna subset selection scheme for an underlay cognitive system serving multiple secondary receivers. The secondary system employs zero-forcing beamforming to nullify the interference to multiple primary users and eliminate

Secondary Choral Directors' Multicultural Teaching Practices, Attitudes and Experiences in International Schools

Science.gov (United States)

Bennett Walling, Catherine

2016-01-01

The purpose of this study was to determine whether secondary choral directors employed at international schools implemented a multicultural education in their programs. Participants (N = 126) were secondary choral directors working at international schools in 59 different countries. A researcher-designed questionnaire was used to collect…

Advances in ambient temperature secondary lithium cells

Science.gov (United States)

Subbarao, S.; Shen, D. H.; Deligiannis, F.; Huang, C-K.; Halpert, G.

1989-01-01

The Jet Propulsion Laboratory is involved in a Research and Development program sponsored by NASA/OAST on the development of ambient temperature secondary lithium cells for future space applications. Some of the projected applications are planetary spacecraft, planetary rovers, and astronaut equipment. The main objective is to develop secondary lithium cells with greater than 100 Wh/kg specific energy while delivering 1000 cycles at 50 percent Depth of Discharge (DOD). To realize these ambitious goals, the work was initially focused on several important basic issues related to the cell chemistry, selection of cathode materials and electrolytes, and component development. The performance potential of Li-TiS2, Li-MoS3, Li-V6O13 and Li-NbSe3 electrochemical systems was examined. Among these four, the Li-TiS2 system was found to be the most promising system in terms of realizable specific energy and cycle life. Some of the major advancements made so far in the development of Li-TiS2 cells are in the areas of cathode processing technology, mixed solvent electrolytes, and cell assembly. Methods were developed for the fabrication of large size high performance TiS2 cathodes. Among the various electrolytes examined, 1.5M LiAsF6/EC + 2-MeTHF mixed solvent electrolyte was found to be more stable towards lithium. Experimental cells activated with this electrolyte exhibited more than 300 cycles at 100 percent Depth of Discharge. Work is in progress in other areas such as selection of lithium alloys as candidate anode materials, optimization of cell design, and development of 5 Ah cells. The advances made at the Jet Propulsion Laboratory on the development of secondary lithium cells are summarized.

Overlay Cognitive Radios With Channel-Aware Adaptive Link Selection and Buffer-Aided Relaying

KAUST Repository

Shaqfeh, Mohammad

2015-08-01

The aim of this work is to maximize the long-term average achievable rate region of a primary and a secondary source-destination pairs operating in an overlay setup over block-fading channels. To achieve this objective, we propose an opportunistic strategy to grant channel access to the primary and secondary sources based on the channel conditions in order to exploit the available multiple-link diversity gains in the system. The secondary source has causal knowledge of the primary messages and it acts as a relay of the primary source in return for getting access to the channel. To maximize the gains of relaying, the relay and destination are equipped with buffers to enable the use of channel-aware adaptive link selection. We propose and optimize different link selection policies and characterize their expected achievable rates. Also, we provide several numerical results to demonstrate the evident mutual benefits of buffer-aided cooperation and adaptive link selection to the primary and the secondary source-destination pairs. © 1972-2012 IEEE.

Overlay Cognitive Radios With Channel-Aware Adaptive Link Selection and Buffer-Aided Relaying

KAUST Repository

Shaqfeh, Mohammad; Zafar, Ammar; Alnuweiri, Hussein; Alouini, Mohamed-Slim

2015-01-01

The aim of this work is to maximize the long-term average achievable rate region of a primary and a secondary source-destination pairs operating in an overlay setup over block-fading channels. To achieve this objective, we propose an opportunistic strategy to grant channel access to the primary and secondary sources based on the channel conditions in order to exploit the available multiple-link diversity gains in the system. The secondary source has causal knowledge of the primary messages and it acts as a relay of the primary source in return for getting access to the channel. To maximize the gains of relaying, the relay and destination are equipped with buffers to enable the use of channel-aware adaptive link selection. We propose and optimize different link selection policies and characterize their expected achievable rates. Also, we provide several numerical results to demonstrate the evident mutual benefits of buffer-aided cooperation and adaptive link selection to the primary and the secondary source-destination pairs. © 1972-2012 IEEE.

Integrating Information and Communication Technology in English Language Teaching: A Case Study of Selected Junior Secondary Schools in Botswana

Science.gov (United States)

Mafuraga, Mbizo; Moremi, Mbiganyi

2017-01-01

The paper discusses how Information and Communication Technology (ICT) could be integrated in the teaching of English Language in Botswana Junior Secondary Schools. It does so by exploring opportunities and challenges faced by teachers of English Language and the students they teach. Fifty five (55) teachers in eleven (11) Junior Secondary Schools…

Selected Statistics from the Public Elementary and Secondary Education Universe: School Year 2012-13. First Look. NCES 2014-098

Science.gov (United States)

Keaton, Patrick

2014-01-01

This National Center for Education Statistics (NCES) First Look report introduces new data for the universe of public elementary and secondary schools and agencies in the United States in school year (SY) 2012-13. Specifically, this report includes statistics that describe: (1) the numbers and types of public elementary and secondary schools and…

Selected Statistics from the Public Elementary and Secondary Education Universe: School Year 2013-14. First Look. NCES 2015-151

Science.gov (United States)

Glander, Mark

2015-01-01

This National Center for Education Statistics (NCES) First Look report introduces new data for the universe of public elementary and secondary schools and agencies in the United States in school year (SY) 2013-14. Specifically, this report includes statistics that describe: (1) the numbers and types of public elementary and secondary schools and…

A novel ion selective sensor for promethium determination

International Nuclear Information System (INIS)

Gupta, Vinod K.; Jain, Rajeev; Hamdan, A.J.; Agarwal, Shilpi; Bharti, Arvind K.

2010-01-01

This is a first promethium 145 ion-selective sensor based on the comparative study of two Schiff base ligands (X 1 and X 2 ) as neutral ionophores. Effect of various plasticizers: 2-nitrophenyloctylether (o-NPOE), dibutyl phosphonate (DBP), dioctylphthalate (DOP), tri-(2-ethylhexyl) phosphate (TEHP), dibutyl butylphosphonate (DBBP), chloronaphthalene (CN) and anion excluders: potassium tetrakis (p-chloropheny1) borate (KTpClPB), sodiumtetraphenylborate (NaTPB) and oleic acid (OA) have been studied. The membrane with a composition of ionophore (X 1 /X 2 ):KTpClPB:PVC:o-NPOE (w/w, %) in the ratio of 5:5:30:60 exhibited best performance. The best responsive membrane sensors (8 and 21) exhibited working concentration range of 4.5 x 10 -7 -1.0 x 10 -2 M and 3.5 x 10 -6 -1.0 x 10 -2 M with a detection limits of 3.2 x 10 -7 M and 2.3 x 10 -6 M and Nernstian slopes of 20.0 ± 0.5, 19.5 ± 0.5 mV decade -1 of activity, respectively. The sensor no. 8 works satisfactorily in partially non-aqueous media up to 10% (v/v) content of methanol, ethanol and acetonitrile. Analytical application of the proposed sensor has been demonstrated in determination of promethium (III) ions in spiked water samples.

Indirect complexometric determination of mercury(II) using potassium bromide as selective masking agent

International Nuclear Information System (INIS)

Sreekumar, N.V.; Nazareth, R.A.; Narayana, B.; Hegde, P.; Manjunatha, B.R.

2002-01-01

A complexometric method for the determination of mercury in presence of other metal ions based on the selective masking ability of potassium bromide towards mercury is described. Mercury(II) present in a given sample solution is first complexed with a known excess of EDTA and the surplus EDTA is titrated against zinc sulfate solution at pH 5-6 using xylenol orange as the indicator. A known excess of 10 % solution of potassium bromide is then added and the EDTA released from Hg-EDTA complex is titrated against standard zinc sulfate solution. Reproducible and accurate results are obtained for 8 mg to 250 mg of mercury(II) with a relative error ±0.28 % and standard deviations /leg 0.5 mg. The interference of various ions is studied. This method was applied to the determination of mercury(II) in its alloys. (author)

Adaptive Virtual Impedance Scheme for Selective Compensation of Voltage Unbalance and Harmonics in Microgrids

DEFF Research Database (Denmark)

Savaghebi, Mehdi; Shafiee, Qobad; Vasquez, Juan Carlos

2015-01-01

and current inner control loops in order to fix the filter capacitor voltage and a virtual impedance loop mainly for voltage harmonics and unbalance compensation. The virtual impedance is set by the central secondary controller to mitigate the voltage distortion at sensitive load bus (SLB). Secondary...... controller is connected to a measurement unit to obtain the data of voltage harmonics and unbalance at microgrid SLB and broadcasts the commands for adjusting the virtual impedance of each unit. A general case with a combined voltage harmonic and unbalance distortion is considered. In such a case, voltage...... distortion is mitigated by selective insertion of capacitive virtual impedances for negative sequence of fundamental component as well as positive and negative sequences of main harmonics. The values of virtual capacitances are determined based on the required voltage quality at the load bus; thus...

Epidemiology of substance use among secondary school learners in Atteridgeville, Gauteng

Directory of Open Access Journals (Sweden)

S V Moodley

2012-02-01

Full Text Available Introduction. Adolescent substance use has a number of adverse consequences for both the individual and society. Anecdotal evidence suggested the existence of a serious substance use problem among learners in Atteridgeville, part of the City of Tshwane Metropolitan Municipality in Gauteng, South Africa. Objectives. The objectives of the study were to determine the prevalence rates and age of initiation of substance use among learners attending secondary schools in Atteridgeville, and the factors, if any, associated with cannabis use. Methods. This was a cross-sectional study. A cluster sampling technique was employed. Twenty-two of the total of 191 grade 8 - 11 classes in the nine Atteridgeville secondary schools were randomly selected, with all 895 learners in the selected classes being invited to participate. Self-administered questionnaires were used to collect data. Statistical analysis was conducted using the survey estimation commands in STATA 10.0. Results. The lifetime prevalence rates for the three most commonly used substances were 51.4% (95% confidence interval (CI 41.5 - 61.5% for alcohol, 25.2% (95% CI 17.1 - 33.3% for cigarettes and 13.2% (95% CI 8.3 - 18.2% for cannabis. Alcohol was also found to have the lowest mean age of initiation at 14.6 years (standard deviation 2.0. Based on CRAFFT screening scores, 30.3% (95% CI 24.5 - 36.1% of learners met the criteria for possible problem substance use. Following multivariate analysis, the factors found to be significantly associated with lifetime cannabis use were age, gender, lifetime cigarette use, lifetime alcohol use, the number of illicit drug users among the learners’ five closest friends, and an older sibling with a history of illicit drug use. Conclusion. The results of the study suggest that substance use among learners in Atteridgeville is widespread and that a comprehensive intervention strategy is required.

Pre-service secondary school science teachers science teaching ...

African Journals Online (AJOL)

PROF.MIREKU

pre-service secondary science teachers' self-efficacy beliefs with regard to gender and educational .... outcome. As a consequence, instruments for the determination of self-efficacy ...... Sex Roles: A Journal of Research, 42, 119–31. Bursal, M.

Landscape composition influences abundance patterns and habitat use of three ungulate species in fragmented secondary deciduous tropical forests, Mexico

Directory of Open Access Journals (Sweden)

G. García-Marmolejo

2015-01-01

Full Text Available Secondary forests are extensive in the tropics. Currently, these plant communities are the available habitats for wildlife and in the future they will possibly be some of the most wide-spread ecosystems world-wide. To understand the potential role of secondary forests for wildlife conservation, three ungulate species were studied: Mazama temama, Odocoileus virginianus and Pecari tajacu. We analyzed their relative abundance and habitat use at two spatial scales: (1 Local, where three different successional stages of tropical deciduous forest were compared, and (2 Landscape, where available habitats were compared in terms of landscape composition (proportion of forests, pastures and croplands within 113 ha. To determine the most important habitat-related environmental factors influencing the Sign Encounter Rate (SER of the three ungulate species, 11 physical, anthropogenic and vegetation variables were simultaneously analyzed through model selection using Akaike’s Information Criterion. We found, that P. tajacu and O. virginianus mainly used early successional stages, while M. temama used all successional stages in similar proportions. The latter species, however, used early vegetation stages only when they were located in landscapes mainly covered by forest (97%. P. tajacu and O. virginianus also selected landscapes covered essentially by forests, although they required smaller percentages of forest (86%. All ungulate species avoided landscape fragments covered by pastures. For all three species, landscape composition and human activities were the variables that best explained SER. We concluded that landscape is the fundamental scale for ungulate management, and that secondary forests are potentially important landscape elements for ungulate conservation.

Secondary antibodies as tools to improve tumor to non tumor ratio at radioimmunolocalisation and radioimmunotherapy

International Nuclear Information System (INIS)

Ullen, A.; Riklund Aalstroem, K.; Hietala, S.O.; Nilsson, B.; Aerlestig, L.; Stigbrand, T.

1996-01-01

One way of selectively improving the efficiency of radioimmunolocalization and radioimmunotherapy is to eliminate redundant, circulating, non-targeting radiolabeled antibodies after saturation of the target sites. Secondary antibodies of different types have been proposed as clearing agents for such purposes. The conceptually different approaches of the 'secondary antibody' strategy including its advantages and limitations are discussed. This mini-review also presents a model describing the kinetics of the components (the antigen, the primary and secondary antibodies) and approaches required to improve the efficacy of both radioimmunolocalization and radioimmunotherapy. (orig.)

Chemical ecology of insect-plant interactions: ecological significance of plant secondary metabolites.

Science.gov (United States)

Nishida, Ritsuo

2014-01-01

Plants produce a diverse array of secondary metabolites as chemical barriers against herbivores. Many phytophagous insects are highly adapted to these allelochemicals and use such unique substances as the specific host-finding cues, defensive substances of their own, and even as sex pheromones or their precursors by selectively sensing, incorporating, and/or processing these phytochemicals. Insects also serve as pollinators often effectively guided by specific floral fragrances. This review demonstrates the ecological significance of such plant secondary metabolites in the highly diverse interactions between insects and plants.

Irradiation effects on secondary structure of protein induced by keV ions

International Nuclear Information System (INIS)

Cui, F.Z.; Lin, Y.B.; Zhang, D.M.; Tian, M.B.

2001-01-01

Protein secondary structure changes by low-energy ion irradiation are reported for the first time. The selected system is 30 keV N + irradiation on bovine serum albumin (BSA). After irradiation at increasing fluences from 1.0x10 15 to 2.5x10 16 ion/cm 2 , Fourier transform infrared spectra analysis was conducted. It was found that the secondary structures of BSA molecules were very sensitive to ion irradiation. Secondary conformations showed different trends of change during irradiation. With the increase of ion fluence from 0 to 2.5x10 16 ion/cm 2 , the fraction of α-helix and β-turns decreased from 17 to 12%, and from 40 to 31%, respectively, while that of random coil and β-sheet structure increased from 18 to 27%, and from 25 to 30%, respectively. Possible explanations for the secondary conformational changes of protein are proposed. (author)

Free energy minimization to predict RNA secondary structures and computational RNA design.

Science.gov (United States)

Churkin, Alexander; Weinbrand, Lina; Barash, Danny

2015-01-01

Determining the RNA secondary structure from sequence data by computational predictions is a long-standing problem. Its solution has been approached in two distinctive ways. If a multiple sequence alignment of a collection of homologous sequences is available, the comparative method uses phylogeny to determine conserved base pairs that are more likely to form as a result of billions of years of evolution than by chance. In the case of single sequences, recursive algorithms that compute free energy structures by using empirically derived energy parameters have been developed. This latter approach of RNA folding prediction by energy minimization is widely used to predict RNA secondary structure from sequence. For a significant number of RNA molecules, the secondary structure of the RNA molecule is indicative of its function and its computational prediction by minimizing its free energy is important for its functional analysis. A general method for free energy minimization to predict RNA secondary structures is dynamic programming, although other optimization methods have been developed as well along with empirically derived energy parameters. In this chapter, we introduce and illustrate by examples the approach of free energy minimization to predict RNA secondary structures.

Determination of the secondary energy from the electron beam with a flattening foil by computer. Percentage depth dose curve fitting using the specific higher order polynomial

Energy Technology Data Exchange (ETDEWEB)

Kawakami, H [Kyushu Univ., Beppu, Oita (Japan). Inst. of Balneotherapeutics

1980-09-01

A computer program written in FORTRAN is described for determining the secondary energy of the electron beam which passed through a flattening foil, using a time-sharing computer service. The procedure of this program is first to fit the specific higher order polynomial to the measured percentage depth dose curve. Next, the practical range is evaluated by the point of intersection R of the line tangent to the fitted curve at the inflection point P and the given dose E, as shown in Fig. 2. Finally, the secondary energy corresponded to the determined practical range can be obtained by the experimental equation (2.1) between the practial range R (g/cm/sup 2/) and the electron energy T (MeV). A graph for the fitted polynomial with the inflection points and the practical range can be plotted on a teletype machine by request of user. In order to estimate the shapes of percentage depth dose curves correspond to the electron beams of different energies, we tried to find some specific functional relationships between each coefficient of the fitted seventh-degree equation and the incident electron energies. However, exact relationships could not be obtained for irreguarity among these coefficients.

Estimating carbon stock in secondary forests

DEFF Research Database (Denmark)

Breugel, Michiel van; Ransijn, Johannes; Craven, Dylan

2011-01-01

of trees and species for destructive biomass measurements. We assess uncertainties associated with these decisions using data from 94 secondary forest plots in central Panama and 244 harvested trees belonging to 26 locally abundant species. AGB estimates from species-specific models were used to assess...... is the use of allometric regression models to convert forest inventory data to estimates of aboveground biomass (AGB). The use of allometric models implies decisions on the selection of extant models or the development of a local model, the predictor variables included in the selected model, and the number...... relative errors of estimates from multispecies models. To reduce uncertainty in the estimation of plot AGB, including wood specific gravity (WSG) in the model was more important than the number of trees used for model fitting. However, decreasing the number of trees increased uncertainty of landscape...

FACTORS CONTRIBUTING TO SUBSTANCE (DRUG ABUSE AMONGMALE ADOLESCENTS IN SOUTH AFRICAN PUBLIC SECONDARY SCHOOLS

Directory of Open Access Journals (Sweden)

Irene Mohasoa

2017-01-01

Full Text Available This small-scale study sought to determine the factors that contribute to use ofdrugs by male adolescents in South African public secondary schools. The studywas conducted in four secondary schools in Zeerust, North West, a province ofSouth Africa. Purposive sampling was employed to select from the secondaryschools 12 male adolescents who were prone to substance abuse problems. Aqualitative research approach was followed underpinned by the interpretiveresearch paradigm. More specifically, a multiple case research design was used.The study was successful in identifying the most commonly used drugs such asalcohol, nicotine, cannabis, and heroin. These drugs are readily available in thesurrounding communities and are affordable to the learners. Socialand economicfactors are the main factors contributing to the use of drugs among maleadolescents. The way in which children are brought up, who they associate withand whether they have access to money to buy the drugs largely contribute to druguse. Thisstudy concludes by proposing mitigation strategies that can be employedto deal with substance abuse scourge before it escalates further. Furthermore, thestudy identifies a need for involvement of various stakeholders to find a solutionto the substanceabuse problem.

A selective and regenerable voltammetric aptasensor for determination of homocysteine

International Nuclear Information System (INIS)

Saeed, Jaber; Mirzaei, Mohammad; Torkzadeh-Mahani, Masoud

2016-01-01

We describe an electrochemical aptasensor for the amino acid homocysteine (hCys). A gold electrode was modified with a highly specific aptamer against hCys (a 66-base DNA oligonucleotide) acting as the recognition probe. The method is highly selective over cysteine and methionine. The effects of accumulation time, type and concentration of accumulation buffer and pH, type and concentration of stripping buffer were studied. Under optimized conditions and a working potential of 1.07 V (vs. Ag/AgCl), the response to hCys is linear in the 0.2 to 10 μM concentration range. The detection limit is 10 nM, and the relative standard deviation is 3.1 % (at 1 μM of hCys). The electrode can be regenerated by immersing it into a 3 M solution of urea solution. The method was applied to the determination of hCys in (spiked) serum and urine and gave recoveries of 88.5 and 96.5 %, respectively. (author)

Transmit Antenna Selection for Multi-User Underlay Cognitive Transmission with Zero-Forcing Beamforming

KAUST Repository

Hanif, Muhammad

2017-03-20

We present a transmit antenna subset selection scheme for an underlay cognitive system serving multiple secondary receivers. The secondary system employs zero-forcing beamforming to nullify the interference to multiple primary users and eliminate inter-user interference to the secondary users simultaneously. Simulation results show that the proposed scheme achieves near-optimal performance with low computational complexity. Lastly, an optimal power allocation strategy is also introduced to improve the secondary network throughput.

Polypyrrole Composite Film for Highly Sensitive and Selective Electrochemical Determination Sensors

International Nuclear Information System (INIS)

Zheng, Xiangli; Tian, Dong; Duan, Shuo; Wei, Maochao; Liu, Shan; Zhou, Changli; Li, Qing; Wu, Gang

2014-01-01

In this paper, polypyrrole (PPy) and benz[a]anthracene-7,12-dione (BaD) were electro-polymerized onto a pyrolytic graphite electrode (PGE), constructing a novel BaD/PPy/PGE platform for electrochemical sensoring. The morphology and electrochemical properties of the fabricated BaD/PPy/PGE were characterized by scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. Furthermore, the electrochemical behavior of benzo[k]fluoranthene (BkF) at the BaD/PPy/PGE was investigated. Due to the specific interactions between BkF and BaD, a wide linear range of BkF detection from 1.0 × 10 −12 to 1.0 × 10 −9 M with good linearity (R 2 = 0.9962) and a low detection limit (1.0 × 10 −13 M, S/N = 3) were demonstrated. Importantly, other similar aromatics which had one ring or more than two rings, such as benzo[a]anthracene, benzo[a]pyrene, pyrene, benzo[ghi]peryle, anthracene, phenanthrene, naphthalene and parachlorophenol, showed insignificant interference on BkF detection. Consequently, this novel BaD/PPy/PGE with excellent stability and selectivity holds promise as an effective BkF electrochemical sensor in aqueous solution. As an example for its practical application, the newly developed sensor was applied to quantitative determination of BkF in waste water samples obtained from a coking plant with satisfactory sensitivity, selectivity, and reversibility

Primary and secondary structural determinants in the receptor binding sequence β-(38-57) from human luteinizing hormone

International Nuclear Information System (INIS)

Keutmann, H.T.; Charlesworth, M.C.; Kitzmann, K.; Mason, K.A.; Johnson, L.; Ryan, R.J.

1988-01-01

The intercysteine loop sequence 38-57 in the β subunit has been shown to be a determinant for expression of biological activity in human lutropin (hLH) and choriogonadotropin (hCG). Together with other sequences, the 38-57 region may contribute to a multicomponent receptor binding domain in hLH/hCG. Because the structural features influencing activity in this important region are not easy to evaluate in the full-length subunit, the authors have used analogues of hLHβ-(38-57) prepared by solid-phase synthesis. The peptides were tested for inhibition of 125 I-labeled hCG binding to rat ovarian membrane receptors. Secondary structure was analyzed by circular dichroism (CD) and by reactivity with antibodies to the native 38-57 peptide. An analogue lacking the 38-57 disulfide linkage retained 20% receptor binding and full immunoreactivity. Far-ultraviolet CD profiles were essentially identical with those of the disulfide-intact peptide; a transition from 10% to 30% α-helix in 90% trifluoroethanol was characteristic of both. The peptide thus appears not to require the disulfide bridge to retain a looped conformation with amphipathic secondary structure. An essential positive charge at position 43 was shown by complete loss of activity upon substitution of Asp or Ala for the Arg found in all known species of LH. These results indicate that the 38-57 sequence is a relatively rigid and structurally autonomous region, not merely a series of residues constrained passively into a loop by a disulfide linkage. It includes segments of ordered structure, probably including both amphipathic helical and turn sequences. Evidence from studies of other hormones suggests that this region may be important to binding and specificity in the glycoprotein hormones as a group

Peer influence on the study habit of secondary school adolescents ...

African Journals Online (AJOL)

This study investigated the influence of peer group on the study habit of secondary school adolescents. A sample of two hundred and ninety two (292) students was randomly selected from nine schools in two Local Government Areas of Ogun State. Two instruments were used to collect data. They are: Adolescents' Peer ...

Student Teachers' Conceptions of Creativity in the Secondary Music Classroom

Science.gov (United States)

Kokotsaki, Dimitra

2011-01-01

This study aims to explore the meaning of the concept of creativity from the perspective of student teachers pursuing a one year teacher training course following their first degree. Seventeen student teachers following a specialist music teaching route in secondary education were selected as the sample for this study to offer their understanding…

Competitive foods and beverages available for purchase in secondary schools--selected sites, United States, 2006.

Science.gov (United States)

2008-08-29

Schools are in a unique position to help improve youth dietary behaviors and prevent and reduce obesity. In most schools, foods and beverages are made available to students through the U.S. Department of Agriculture (USDA) school meal programs and the sale of competitive foods, which are any foods and beverages sold at a school separately from the USDA school meal programs. Foods and beverages sold through the USDA school meal programs must meet federal nutrition requirements. Competitive foods are not subject to any federal nutrition standards unless they are sold inside the food service area during mealtimes. A 2007 Institute of Medicine (IOM) report concluded that schools should limit the availability of less nutritious competitive foods or include more nutritious foods and beverages if they make competitive foods available. To identify the types of competitive foods and beverages available for purchase from vending machines or at school stores, canteens, or snack bars, CDC analyzed data from the 2006 School Health Profiles for public secondary schools in 36 states and 12 large urban school districts. CDC also compared 2004 and 2006 data among 24 states and nine large urban school districts. This report summarizes the results of these analyses, which indicated that, from 2004 to 2006, the median percentage of secondary schools across states allowing students to purchase chocolate candy and salty snacks that are not low in fat decreased; however, in 2006, secondary schools still offered less nutritious foods and beverages that compete with school meals. School and public health officials should work together with families to provide foods and beverages at school that follow the IOM recommendations.

Optimization methods for activities selection problems

Science.gov (United States)

Mahad, Nor Faradilah; Alias, Suriana; Yaakop, Siti Zulaika; Arshad, Norul Amanina Mohd; Mazni, Elis Sofia

2017-08-01

Co-curriculum activities must be joined by every student in Malaysia and these activities bring a lot of benefits to the students. By joining these activities, the students can learn about the time management and they can developing many useful skills. This project focuses on the selection of co-curriculum activities in secondary school using the optimization methods which are the Analytic Hierarchy Process (AHP) and Zero-One Goal Programming (ZOGP). A secondary school in Negeri Sembilan, Malaysia was chosen as a case study. A set of questionnaires were distributed randomly to calculate the weighted for each activity based on the 3 chosen criteria which are soft skills, interesting activities and performances. The weighted was calculated by using AHP and the results showed that the most important criteria is soft skills. Then, the ZOGP model will be analyzed by using LINGO Software version 15.0. There are two priorities to be considered. The first priority which is to minimize the budget for the activities is achieved since the total budget can be reduced by RM233.00. Therefore, the total budget to implement the selected activities is RM11,195.00. The second priority which is to select the co-curriculum activities is also achieved. The results showed that 9 out of 15 activities were selected. Thus, it can concluded that AHP and ZOGP approach can be used as the optimization methods for activities selection problem.

Observational evidence for pollution-influenced selective uptake contributing to biogenic secondary organic aerosols in the southeastern U.S.

Science.gov (United States)

Liu, J.; Russell, L. M.; Lee, A. K. Y.; McKinney, K. A.; Surratt, J. D.; Ziemann, P. J.

2017-08-01

During the 2013 Southern Oxidant and Aerosol Study, aerosol mass spectrometer measurements of submicron mass and single particles were taken at Look Rock, Tennessee. Their concentrations increased during multiday stagnation events characterized by low wind, little rain, and increased daytime isoprene emissions. Organic mass (OM) sources were apportioned as 42% "vehicle-related" and 54% biogenic secondary organic aerosol (bSOA), with the latter including "sulfate-related bSOA" that correlated to sulfate (r = 0.72) and "nitrate-related bSOA" that correlated to nitrate (r = 0.65). Single-particle mass spectra showed three composition types that corresponded to the mass-based factors with spectra cosine similarity of 0.93 and time series correlations of r > 0.4. The vehicle-related OM with m/z 44 was correlated to black carbon, "sulfate-related bSOA" was on particles with high sulfate, and "nitrate-related bSOA" was on all particles. The similarity of the m/z spectra (cosine similarity = 0.97) and the time series correlation (r = 0.80) of the "sulfate-related bSOA" to the sulfate-containing single-particle type provide evidence for particle composition contributing to selective uptake of isoprene oxidation products onto particles that contain sulfate from power plants.

Analysis of secondary cytoreduction for recurrent ovarian cancer by robotics, laparoscopy and laparotomy.

Science.gov (United States)

Magrina, Javier F; Cetta, Rachel L; Chang, Yu-Hui; Guevara, Gregory; Magtibay, Paul M

2013-05-01

Analysis of perioperative outcomes and survival of patients with recurrent ovarian cancer undergoing secondary cytoreduction by robotics, laparoscopy, or laparotomy. Retrospective analysis of 52 selected patients with recurrent ovarian cancer undergoing secondary cytoreduction by laparoscopy (9), laparotomy (33) or robotics (10) between January 2006 and December 2010. Comparison was made by a total of 21 factors including age, BMI, number of previous surgeries, tumor type and grade, number of procedures, and 15 types of procedures performed at secondary cytoreduction. For all patients, the mean operating time was 213.8 min, mean blood loss 657.4 ml; and mean hospital stay 7.5 days. Complete debulking was achieved in 75% of patients. Postoperative complications were noted in 36.5% of patients. Overall and progression-free survival at 3-years were 58.8% and 34.1%, respectively. Laparoscopy and robotics had reduced blood loss and hospital stay, while no differences were observed among the three groups for operating time, complications, complete debulking, and survival. Selected patients with recurrent ovarian cancer benefit from a laparoscopic or robotic secondary cytoreduction without compromising survival. Robotics and laparoscopy provide similar perioperative outcomes, and reduced blood loss and shorter hospital stay as compared to laparotomy. Laparotomy seems preferable for patients with widespread peritoneal implants, multiple sites of recurrence, and/or extensive adhesions. Copyright © 2013 Elsevier Inc. All rights reserved.

Determination of isotopic composition of uranium in microparticles by secondary ion mass spectrometry

International Nuclear Information System (INIS)

Veniaminov, N.N.; Kolesnikov, O.N.; Stebel'kov, V.A.

1992-01-01

Aerosol particles including uranium in their composition are specific atmospheric polutants. Uranium is used as nuclear fuel in atomic power stations and in spacecraft power units, and also as a component of nuclear warheads. In order to monitor the discharge of uranium-containing aerosol particles to the atmosphere, they must first be identified. As an example, one may cite an investigation of the elemental composition and radioactivity of particles formed in the accident at the Chernobyl atomic power station. One of the most informative indicators of the origin of uranium-containing aerosol particles is the isotopic composition of the uranium. Secondary ion mass spectrometry (SIMS) offers unique possibilities for the measurement of isotope ratios in individual microscopic objects. At the same time, a measurement of isotope ratios of sulfur in microsection of galenite PbS 2 has shown that the application of SIMS for these purposes is seriously limited by the difference in yield of secondary ions for isotopes with different masses. These discrimination effects, in the case of light elements such as boron, may result in distortion of the isotope ratios by several percent. In the case of heavy elements, however, the effect is less significant, amounting to about 0.5% for lead isotopes. 13 refs., 3 figs., 1 tab

Determination of Selection Index of Cocoa (Theobroma Cacao L.) Yield Traits Using Regression Methods

OpenAIRE

Setyawan, Bayu; Taryono; Mitrowihardjo, Suyadi

2016-01-01

The increasing chocolate consumption has not been followed by growing production of dry cocoa beans. In order to support the increase in cocoa production, planting materials with high yield are needed. The objective of this research was to determine the components of cocoa traits affecting weight of dry cocoa beans, and set a selection index for superior cocoa trees. The experiment material were four cocoa hybrid populations of which their family ancestry were unknown, and were planted on Sam...

Highly Selective and Sensitized Spectrophotometric Determination of Iron (3) Following Potentiometric Study

International Nuclear Information System (INIS)

Shokrollahi, A.; Ghaedi, M.; Rajabi, H.R.

2007-01-01

A simple, selective and sensitized spectrophotometric method for determination of trace amounts of Fe 3+ ion in tap and waste water solutions has been described. The spectrophotometric determination of Fe 3+ ion using Ferron in the presence of N,N-Dodecy trimethylammonium bromide (DTAB) has been carried out. The Beer's law is obeyed over the concentration range of 0.05-2.6 μg mL -1 of Fe 3+ ion with the relative standard deviation (RSD %) 3 L mol -1 cm -1 . Potentiometric pH titration has been used for prediction of protonation constants of ferron, and evaluating its stoichiometry and respective stability constant with Fe 3+ ion. As it is obvious the most likely species of ferron alone and its complexes are LH (log=7.64), LH 2 (logK=10.52), LH 3 (logK=11.74) and ML 2 (logβ= 23.68), ML 3 (logβ23.68), ML 3 H (logβ= 23.68), ML 3 H 2 (logβ= 23.68) and ML(OH) 2 (logβ=23.68) respectively

A systematic review of post-secondary transition interventions for youth with disabilities.

Science.gov (United States)

Lindsay, Sally; Lamptey, De-Lawrence; Cagliostro, Elaine; Srikanthan, Dilakshan; Mortaji, Neda; Karon, Leora

2018-05-04

Youth with disabilities have lower rates of enrollment and completion of post-secondary education compared with youth without disabilities. The objective of this systematic review is to understand the best practices and components of post-secondary transition programs for youth with disabilities. Systematic searches of six international databases identified 18 studies meeting our inclusion criteria (youth with a disability, aged 15-30; focusing on post-secondary education program or intervention, published from 1997 to 2017). These studies were analyzed with respect to the characteristics of the participants, methodology, results, and quality of the evidence. Among the 18 studies, 2385 participants (aged 13-28, mean 17.7 years) were represented across three countries (US, Canada, and Australia). Although the outcomes of the post-secondary transition programs varied across the studies, all of them reported an improvement in at least one of the following: college enrollment, self-determination, self-confidence, social and vocational self-efficacy, autonomy, social support, career exploration, and transition skills. The post-secondary transition programs varied in duration, length, number of sessions, and delivery format which included curriculum-based, online, immersive residential experience, mentoring, simulation, self-directed, technology-based, and multi-component. Our findings highlight that post-secondary transition programs have the potential to improve self-determination, transition skills, and post-secondary outcomes among youth with disabilities. Implications for rehabilitation Post-secondary education interventions have a beneficial influence on post-secondary and related transition outcomes in youth with disabilities. Clinicians and educators should consider having multiple components, involving several sessions that include a curriculum, immersive college residential experience, mentoring, and/or simulations in their interventions for optimum program

Cosmogenic Secondary Radiation from a Nearby Supernova

Science.gov (United States)

Overholt, Andrew

2017-01-01

Increasing evidence has been found for multiple supernovae within 100 pc of the solar system. Supernovae produce large amounts of cosmic rays which upon striking Earth's atmosphere, produce a cascade of secondary particles. Among these cosmic ray secondaries are neutrons and muons, which penetrate far within the atmosphere to sea level and even below sea level. Muons and neutrons are both forms of ionizing radiation which have been linked to increases in cancer, congenital malformations, and other maladies. This work focuses on the impact of muons, as they penetrate into ocean water to impact the lowest levels of the aquatic food chain. We have used monte carlo simulations (CORSIKA, MCNPx, and FLUKA) to determine the ionizing radiation dose due to cosmic ray secondaries. This information shows that although most astrophysical events do not supply the necessary radiation flux to prove dangerous; there may be other impacts such as an increase to mutation rate.

The determination of small amounts of fluoride in uranium compounds by use of an ion-selective electrode

International Nuclear Information System (INIS)

Shelton, B.M.

1975-01-01

A method is presented for the determination of fluoride in uranium metal and oxide at levels from 16 p.p.m. upwards. Uranium is separated from fluoride by extraction into a solution of di(2-ethylhexyl)-phosphoric acid (HDEHP) in carbon tetrachloride. The fluoride remaining in the aqueous phase is determined by potentiometric measurement with an ion-selective electrode. A correction is made for the fluoride lost during the dissolution or extraction step, or both, which is based on a determination of the apparent loss of fluoride on spiked samples that are taken through the whole procedure [af

A Study of Job Satisfaction of Secondary School Administrators in ...

African Journals Online (AJOL)

This paper was concerned with studying the job satisfaction of secondary school administrators in Kano state, Nigeria. Survey design was used and a random sampling was used to select the study sample of 421 subjects used for the study. The Job Descriptive Index was used to collect data. Five hypotheses were raised in ...

Determination of Effective Criteria for Location Selection of Kiln Wood Drying Plants by AHP Technique

Directory of Open Access Journals (Sweden)

Rahim Mohebbi

2011-12-01

Full Text Available This study was aimed at determining the effective criteria for location selection of wood drying plants in Iran. For this purpose, after review and field visit of the industries, 35 key indicators were identified. These criteria were divided into five major groups as: materials, infrastructure, technical, economical and instructional indices. The priority rates of these criteria and sub-criteria were evaluated by AHP technique. The results indicated that among 35 effective sub-criteria in location selection of the plants, the sub-criteria of quality of raw materials(0.152, purchasing raw materials, land cost, profitability, reliability of supply, and sales had the highest priorities, which were rated as 0.118, 0.105, 0.067, 0.061 and 0.057, respectively

Pre-Service Secondary Science and Mathematics Teachers' Classroom Management Styles in Turkey

Science.gov (United States)

Yilmaz, Kursad

2009-01-01

The aim of this study is to determine Pre-service secondary science and mathematics teachers' classroom management styles in Turkey. In addition, differences in pre-service secondary science and mathematics teachers' classroom management styles by gender, and field of study were examined. In the study, the survey model was employed. The research…

Cooperative learning in science: intervention in the secondary school

Science.gov (United States)

Topping, K. J.; Thurston, A.; Tolmie, A.; Christie, D.; Murray, P.; Karagiannidou, E.

2011-04-01

The use of cooperative learning in secondary school is reported - an area of considerable concern given attempts to make secondary schools more interactive and gain higher recruitment to university science courses. In this study the intervention group was 259 pupils aged 12-14 years in nine secondary schools, taught by 12 self-selected teachers. Comparison pupils came from both intervention and comparison schools (n = 385). Intervention teachers attended three continuing professional development days, in which they received information, engaged with resource packs and involved themselves in cooperative learning. Measures included both general and specific tests of science, attitudes to science, sociometry, self-esteem, attitudes to cooperative learning and transferable skills (all for pupils) and observation of implementation fidelity. There were increases during cooperative learning in pupil formulation of propositions, explanations and disagreements. Intervened pupils gained in attainment, but comparison pupils gained even more. Pupils who had experienced cooperative learning in primary school had higher pre-test scores in secondary education irrespective of being in the intervention or comparison group. On sociometry, comparison pupils showed greater affiliation to science work groups for work, but intervention pupils greater affiliation to these groups at break and out of school. Other measures were not significant. The results are discussed in relation to practice and policy implications.

Educación secundaria Argentina: dinámicas de selección y diferenciación Secondary education in Argentina: selection and differentiation dynamics

Directory of Open Access Journals (Sweden)

Guillermina Tiramonti

2011-12-01

Full Text Available El articulo analiza las dinámicas de selección del sistema educativo nacional haciendo especial hincapié en el nivel medio y reflexiona sobre la influencia de nuestra configuración cultural en la definición de estas dinámicas. Los rasgos culturales que se identifican como promotores de la dinámica de selección son por un lado la preservación del mito igualitarista y por otro un exacerbado individualismo. La pretensión igualitarista ha desplazado la comprobación del mérito como base de la diferenciación para remplazarlo por una incorporación segregada de la población a instituciones formalmente iguales; y, el desarrollo, en el interior de las instituciones, de un sistema de promoción desregulado basado en los recursos individuales de los alumnos y su capacidad de ponerlos en juego a favor del éxito de sus trayectorias educativas. Esta tecnología de selección está presente tanto en las escuelas medias públicas como en las tradicionales universidades públicas. En esta competencia abierta son los sectores medios los que lograron ascender en el sistema en desmedro de los sectores sociales más bajos que tienen dificultades para actualizar sus recursos en un ámbito escolar basado en un patrón mesocrático.This article analyzes the national educational system's selection dynamics - especially on the secondary education - and the influence of our own cultural configuration in the definition of these mechanisms. The cultural characteristics identified as promoters of the selection dynamic are, on one hand, the egalitarian myth and, on the other, the exacerbated individualism. The equalitarian pretension has displaced merit verification from the basis of differentiation, and has replaced it for a segregated incorporation of population to formally equal institutions, as well as for the development of a deregulated promoting system inside institutions based on student's individual resources and capacity of making use of them for

Social determinants of health in selected slum areas in Jordan: challenges and policy directions.

Science.gov (United States)

Ajlouni, Musa T

2016-01-01

The unplanned urbanization in Jordan has over time created many informal settlements "slums" around big cities as Amman, Zerka and Aqaba. The purpose of this study was to highlight the most common challenges related to social determinants of health in two selected slum areas in Amman and Aqaba and suggest policy directions and interventions to meet these challenges. In addition to a prestructured interview with all household heads living in the two slum sites, focus group meetings with a purposefully selected sample of 12 slum dwellers in each site were used to assess the structural and intermediary determinants of health as perceived by slum residents in the two study locations. The study found that slum residents in the two locations suffer from many challenges as severe poverty; unemployment; illiteracy and low education attainments; gender discrimination; insufficient and poor diet; social and official exclusion; unhealthy environment; lack of water supply, electricity and basic sanitation facilities; high prevalence of diseases; and insufficient and inappropriate health services. Specific policy directions to meet these challenges were recommended and grouped into three main clusters: social protection, social inclusion and empowerment. New plans and tools should be developed by local authorities in Jordan to understand, protect, include and empower those vulnerable people who are forced to live in these unhealthy and inhuman environments. Copyright © 2014 John Wiley & Sons, Ltd.

Career Status of Secondary Principals in Small Schools in the Southwest.

Science.gov (United States)

Seifert, Edward H.

1985-01-01

A random sample of 559 secondary small school principals in Arkansas, Colorado, New Mexico, Oklahoma, and Texas revealed that 73 percent of the principals were actively seeking new positions or were leaving school administration. The findings have implications for selection procedures, salary/fringe benefit packages, principal autonomy, evaluation…

Host plant selection by a monophagous herbivore is not mediated by quantitative changes in unique plant chemistry : Agonopterix alstroemeriana and Conium maculatum

OpenAIRE

Castells, Eva

2008-01-01

Host plant selection by ovipositing females is a key process determining the success of phytophagous insects. In oligophagous lepidopterans, host-specific plant secondary chemicals are expected to be dominant factors governing oviposition behavior; distinctive compounds can serve as high-contrast signals that clearly differentiate confamilial hosts from non-hosts increasing the accuracy of host quality evaluation. Agonopterix alstroemeriana (Clerk) (Lepidoptera: Oecophoridae) and Conium macul...

Full-Duplex Relay Selection in Cognitive Underlay Networks

KAUST Repository

Khafagy, Mohammad Galal

2017-09-30

In this work, we analyze the performance of full-duplex relay selection (FDRS) in spectrum-sharing networks. Contrary to half-duplex relaying, full-duplex relaying (FDR) enables simultaneous listening/forwarding at the secondary relay(s), thereby allowing for a higher spectral efficiency. However, since the source and relay simultaneously transmit in FDR, their superimposed signal at the primary receiver should now satisfy the existing interference constraint, which can considerably limit the secondary network throughput. In this regard, relay selection can offer an adequate solution to boost the secondary throughput while satisfying the imposed interference limit. We first analyze the performance of opportunistic FDRS with residual self-interference (RSI) by deriving the exact cumulative distribution function of its end-to-end signal-to-interference-plus-noise ratio under Nakagami-m fading. We also evaluate the offered diversity gain of relay selection for different full-duplex cooperation schemes in the presence/absence of a direct source-destination link. When the adopted RSI link gain model is sublinear in the relay power, which agrees with recent research findings, we show that remarkable diversity gain can be recovered even in the presence of an interfering direct link. Second, we evaluate the end-to-end performance of FDRS with interference constraints due to the presence of a primary receiver. Finally, the presented exact theoretical findings are verified by numerical simulations.

Knowledge and Perceptions of Visual Communications Curriculum in Arkansas Secondary Agricultural Classrooms: A Closer Look at Experiential Learning Integrations

Science.gov (United States)

Pennington, Kristin; Calico, Carley; Edgar, Leslie D.; Edgar, Don W.; Johnson, Donald M.

2015-01-01

The University of Arkansas developed and integrated visual communications curriculum related to agricultural communications into secondary agricultural programs throughout the state. The curriculum was developed, pilot tested, revised, and implemented by selected secondary agriculture teachers. The primary purpose of this study was to evaluate…

adapting the study of chemistry in senior secondary schools

African Journals Online (AJOL)

unesco

There have been economic pressures on the secondary school system of The. Gambia: pressures arising ... facilities such as electricity, water, telecommunications, etc. There have been .... The reliability of the instrument was determined using ...

Secondary cleanup of Idaho Chemical Processing Plant solvent

International Nuclear Information System (INIS)

Mailen, J.C.

1985-01-01

Solvent from the Idaho Chemical Processing Plant (ICPP) (operated by Westinghouse Idaho Nuclear Company, Inc.) has been tested to determine the ability of activated alumina to remove secondary degradation products - those degradation products which are not removed by scrubbing with sodium carbonate

Determination of pigments in colour layers on walls of some selected historical buildings using optical and scanning electron microscopy

International Nuclear Information System (INIS)

Skapin, A. Sever; Ropret, P.; Bukovec, P.

2007-01-01

For successful restoration of painted walls and painted coloured finishing coats it is necessary to determine the composition of the original colour layers. Identification of the pigments used in The Cistercian Abbey of Sticna and The Manor of Novo Celje was carried out using optical and scanning electron microscopy. Selected samples of wall paintings were inspected by the combined application of an optical microscope and a low-vacuum Scanning Electron Microscope to determine their colour and structural features and to identify the position of individual pigment grains. Energy dispersive spectroscopy was used to determine the elemental distribution on selected surfaces and elemental composition of individual pigments. It was found that the most abundantly used pigments were iron oxide red, cinnabar, green earth, umber, calcium carbonate white, ultramarine, yellow ochre and carbon black. These identifications have allowed us to compare the use of various pigments in buildings from different historical periods

Influence of Counselling Services on Perceived Academic Performance of Secondary School Students in Lagos State

Directory of Open Access Journals (Sweden)

Foluke Nike Bolu-Steve

2017-04-01

Full Text Available This study aimed at looking at the influence of counseling services on perceived academic performance of secondary school students in Lagos State. At the first stage, the researchers purposively selected Ikorodu L.G.A in Lagos State. At the researchers selected two schools (1 Private schools, & 1 Public schools, using simple random technique. Thus, a total of two schools were picked in each of the L.G.A. Finally, simple random sampling was used in selecting eighty students in each L.G.A, thus making a total of two hundred and forty Senior Secondary students that participated in the study. Six hypotheses were generated for the purpose of this study. Data were gathered using a researcher designed instrument tagged “Influence of Counselling Service on Academic Performance of Students Questionnaire (ICAPSQ. The findings of this study showed that there was no significant difference on the basis of age, class level and school type. However a significant difference was found on the basis of respondent’s religion, gender and the number of times the students visited the counselor. It was therefore recommended that the ministry of education should ensure that guidance and counselling units are established in all public and private secondary schools in Nigeria.

Determining Methods used in Teaching Geography in Secondary Schools in Rongo District, Kenya

OpenAIRE

Omoro Benjamin; Luke Wakhungu Nato

2014-01-01

This article dealt with methods of teaching Geography in Kenya but also the world over. The importance of Geography in secondary school curriculum cannot be overemphasized. Improving the performance of Geography education is a great societal need in Kenya not only for industrialization of the country as contained in the vision 2030 but also for ensuring food security in the country through practices like land reclamation and irrigation farming The objective of this article was; to find out th...

Relay selection in underlay cognitive networks with fixed transmission power nodes

KAUST Repository

Hussain, Syed Imtiaz

2013-07-31

Underlay cognitive networks operate simultaneously with primary networks satisfying stringent interference constraints, which reduces their transmission power and coverage area. To reach remote destinations, secondary sources use relaying techniques. Selecting the best relay among the available ones is a well known technique. Recently, selective cooperation is investigated in cognitive networks where the secondary nodes can adapt their transmission power to always satisfy the interference threshold. In this paper, we investigate a situation where the secondary nodes have a fixed transmission power and may violate the interference threshold. We present two relay selection schemes; the first one excludes the relays not satisfying the interference constraint and then picks up a relay from the remaining ones that can provide the maximum signal-to-noise ratio (SNR). The other scheme uses a quotient of the relay link SNR and the interference from the relay to the primary user and optimizes it to maximise the relay link SNR. We derive closed form expressions for outage probability, bit error rate, channel capacity and diversity of the system for both schemes by using tight approximations. We also study mutual effects of interference. Simulation results confirm the analytical results and reveal that the relay selection is feasible at low SNRs. Copyright © 2013 John Wiley & Sons, Ltd.

Determination of hepatocellular carcinoma grade by needle biopsy is unreliable for liver transplant candidate selection.

Science.gov (United States)

Court, Colin M; Harlander-Locke, Michael P; Markovic, Daniela; French, Samuel W; Naini, Bita V; Lu, David S; Raman, Steven S; Kaldas, Fady M; Zarrinpar, Ali; Farmer, Douglas G; Finn, Richard S; Sadeghi, Saeed; Tomlinson, James S; Busuttil, Ronald W; Agopian, Vatche G

2017-09-01

The objective of this article is to evaluate the utility of preoperative needle biopsy (PNB) grading of hepatocellular carcinoma (HCC) as a biomarker for liver transplantation (LT) candidate selection. Given the prognostic significance of HCC tumor grade, PNB grading has been proposed as a biomarker for LT candidate selection. Clinicopathologic characteristics of HCC LT recipients (1989-2014) with a PNB were analyzed, and the concordance of PNB grade to explant grade and vascular invasion was assessed to determine whether incorporation of PNB grade to accepted transplant criteria improved candidate selection. Of 965 patients undergoing LT for HCC, 234 (24%) underwent PNB at a median of 280 days prior to transplant. Grade by PNB had poor concordance to final explant pathology (κ = 0.22; P = 0.003), and low sensitivity (29%) and positive predictive value (35%) in identifying poorly differentiated tumors. Vascular invasion was predicted by explant pathologic grade (r s = 0.24; P Liver Transplantation 23 1123-1132 2017 AASLD. © 2017 by the American Association for the Study of Liver Diseases.

Antigenic variation of TprK facilitates development of secondary syphilis.

Science.gov (United States)

Reid, Tara B; Molini, Barbara J; Fernandez, Mark C; Lukehart, Sheila A

2014-12-01

Although primary syphilis lesions heal spontaneously, the infection is chronic, with subsequent clinical stages. Healing of the primary chancre occurs as antibodies against outer membrane antigens facilitate opsonophagocytosis of the bacteria by activated macrophages. TprK is an outer membrane protein that undergoes antigenic variation at 7 variable regions, and variants are selected by immune pressure. We hypothesized that individual TprK variants escape immune clearance and seed new disseminated lesions to cause secondary syphilis. As in human syphilis, infected rabbits may develop disseminated secondary skin lesions. This study explores the nature of secondary syphilis, specifically, the contribution of antigenic variation to the development of secondary lesions. Our data from the rabbit model show that the odds of secondary lesions containing predominately TprK variant treponemes is 3.3 times higher than the odds of finding TprK variants in disseminated primary lesions (odds ratio [OR] = 3.3 [95% confidence interval {CI}, 0.98 to 11.0]; P = 0.055) and that 96% of TprK variant secondary lesions are likely seeded by single treponemes. Analysis of antibody responses demonstrates significantly higher antibody titers to tprK variable region sequences found in the inoculum compared to reactivity to tprK variant sequences found in newly arising secondary lesions. This suggests that tprK variants escape the initial immune response raised against the V regions expressed in the inoculum. These data further support a role for TprK in immune evasion and suggest that the ability of TprK variants to persist despite a robust immune response is instrumental in the development of later stages of syphilis. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Age determination of mallards

Science.gov (United States)

Krapu, G.L.; Johnson, D.H.; Dane, C.W.

1979-01-01

A technique for distinguishing adult from yearling wild mallards (Anas platyrhynchos), from late winter through the nesting season, was developed by applying discriminant analysis procedures to selected wing feather characters of 126 yearlings and 76 adults (2-year-olds) hand-reared from wild eggs during 1974, 1975, and 1977. Average values for feather characters generally increased as the birds advanced from yearlings to adults. Black-white surface area of greater secondary covert 2 was the single most reliable aging character identified during the study. The error rate was lowest in females (3%) when discriminant functions were used with measurements of primary 1 weight and black-white area of greater secondary covert 2 and in males (9%) when the functions were used with black-white area of greater secondary coverts 1, 2, and 3. Methodology precludes aging of birds in the field during capture operations.

Lichen secondary metabolites affect growth of Physcomitrella patens by allelopathy.

Science.gov (United States)

Goga, Michal; Antreich, Sebastian J; Bačkor, Martin; Weckwerth, Wolfram; Lang, Ingeborg

2017-05-01

Lichen secondary metabolites can function as allelochemicals and affect the development and growth of neighboring bryophytes, fungi, vascular plants, microorganisms, and even other lichens. Lichen overgrowth on bryophytes is frequently observed in nature even though mosses grow faster than lichens, but there is still little information on the interactions between lichens and bryophytes.In the present study, we used extracts from six lichen thalli containing secondary metabolites like usnic acid, protocetraric acid, atranorin, lecanoric acid, nortistic acid, and thamnolic acid. To observe the influence of these metabolites on bryophytes, the moss Physcomitrella patens was cultivated for 5 weeks under laboratory conditions and treated with lichen extracts. Toxicity of natural mixtures of secondary metabolites was tested at three selected doses (0.001, 0.01, and 0.1 %). When the mixture contained substantial amounts of usnic acid, we observed growth inhibition of protonemata and reduced development of gametophores. Significant differences in cell lengths and widths were also noticed. Furthermore, usnic acid had a strong effect on cell division in protonemata suggesting a strong impact on the early stages of bryophyte development by allelochemicals contained in the lichen secondary metabolites.Biological activities of lichen secondary metabolites were confirmed in several studies such as antiviral, antibacterial, antitumor, antiherbivore, antioxidant, antipyretic, and analgetic action or photoprotection. This work aimed to expand the knowledge on allelopathic effects on bryophyte growth.

Goal Orientation among Boys and Girls in Higher Secondary Schools of Kerala: How Parenting Styles Influence It?

Science.gov (United States)

Gafoor, Kunnathodi Abdul; Kurukkan, Abidha

2014-01-01

The purpose of the study is to investigate the relation between parenting style and goal orientation among boys and girls in higher secondary schools of Kerala. Four types of parenting style and five categories of goal orientation. The sample comprised of 467 girls and 365 boys from higher secondary school in Kerala who were selected through…

School Violence in Secondary Education in the Governorate of Mafraq: Forms, Causes and Prevention--A Case Study

Science.gov (United States)

Khaled, Mohammad S. Bani

2014-01-01

This study considers school violence. It was investigated in secondary schools in the governorate of Mafraq. The aim is to identify the forms and causes of the phenomenon; hence to come out with the preventive and remedial measures, accordingly. The study was conducted in one of the secondary schools selected randomly in the city of Mafraq in the…