Trace element studies at University of Pittsburgh

International Nuclear Information System (INIS)

Cohen, B.L.; Chan, K.C.; Shabason, L.; Wedberg, G.; Rudolph, H.

1974-01-01

Seven areas of research are discussed. A method was developed for analyzing samples for their major constituent elements by irradiating with protons and detecting prompt gamma rays, mostly produced in (p,p'γ) reactions. Among other applications, the method was used to analyze air particulates for C, N, O, Al, Si, S, Co, and Fe. Trace element analysis by proton or alpha particle induced x-ray fluorescence was used on thin samples in a study of the variations of Pb, Br, Fe, and Zn in air particulates as a function of time. Among other applications this method was also used in studying trace elements in rainwater. An x-ray fluorescence method that is effective in the analysis of thick samples was developed. A method based on measuring energies of elastically scattered protons was developed for the analysis of light elements. The use of proton and neutron activation analyses, as well as methods for studying depth profiles for hydrogen and helium in materials are discussed

Thyroid functions and trace elements in pediatric patients with exogenous obesity.

Science.gov (United States)

Cayir, Atilla; Doneray, Hakan; Kurt, Nezahat; Orbak, Zerrin; Kaya, Avni; Turan, Mehmet Ibrahim; Yildirim, Abdulkadir

2014-02-01

Obesity is a multifactorial disease developing following impairment of the energy balance. The endocrine system is known to be affected by the condition. Serum thyroid hormones and trace element levels have been shown to be affected in obese children. Changes in serum thyroid hormones may result from alterations occurring in serum trace element levels. The aim of this study was to evaluate whether or not changes in serum thyroid hormone levels in children with exogenous obesity are associated with changes in trace element levels. Eighty-five children diagnosed with exogenous obesity constituted the study group, and 24 age- and sex-matched healthy children made up the control group. Serum thyroid stimulating hormone (TSH), free thyroxine (fT4), free triiodothyronine (fT3), thyroglobulin (TG), selenium (Se), zinc (Zn), copper (Cu), and manganese (Mn) levels in the study group were measured before and at the third and sixth months of treatment, and once only in the control group. Pretreatment fT4 levels in the study group rose significantly by the sixth month (p = 0.006). Zn levels in the patient group were significantly low compared to the control group (p = 0.009). Mn and Se levels in the obese children before and at the third and sixth months of treatment were significantly higher than those of the control group (p = 0.001, p = 0.001). In conclusion, fT4, Zn, Cu, Mn, and Se levels are significantly affected in children diagnosed with exogenous obesity. The change in serum fT4 levels is not associated with changes in trace element concentrations.

Population specific absorption studies for some diet incorporated trace elements : comparison with ICRP data

International Nuclear Information System (INIS)

Parameswaran, M.; Dang, H.S.

1999-01-01

Daily intake and excretion can provide an important information regarding the absorption through the gastro-intestinal tract (f1 factor) of trace elements incorporated in diet. The absorption may depend upon the kind of diet consumed, the content of the fibre, protein etc and it could be quite different for two populations groups with entirely different food habits. ICRP has provided data on the intake and excretion of 63 trace elements by Caucasian population representing North American and European adults. This paper reports intake and excretion of twelve elements Na, K, Ca, Mg, Cu, Mn, Rb, Fe, Zn, Sr, Li and Cr for an urban adult Indian population group and compares with corresponding data on ICRP reference man. (author)

Trace conditioning in insects – Keep the trace!

Directory of Open Access Journals (Sweden)

Kristina V Dylla

2013-08-01

Full Text Available Trace conditioning is a form of associative learning that can be induced by presenting a conditioned stimulus (CS and an unconditioned stimulus (US following each other, but separated by a temporal gap. This gap distinguishes trace conditioning from classical delay conditioning, where the CS and US overlap. To bridge the temporal gap between both stimuli and to form an association between CS and US in trace conditioning, the brain must keep a neural representation of the CS after its termination – a stimulus trace. Behavioral and physiological studies on trace and delay conditioning revealed similarities between the two forms of learning, like similar memory decay and similar odor identity perception in invertebrates. On the other hand differences were reported also, like the requirement of distinct brain structures in vertebrates or disparities in molecular mechanisms in both vertebrates and invertebrates. For example, in commonly used vertebrate conditioning paradigms the hippocampus is necessary for trace but not for delay conditioning, and Drosophila delay conditioning requires the Rutabaga adenylyl cyclase, which is dispensable in trace conditioning. It is still unknown how the brain encodes CS traces and how they are associated with a US in trace conditioning. Insects serve as powerful models to address the mechanisms underlying trace conditioning, due to their simple brain anatomy, behavioral accessibility and established methods of genetic interference. In this review we summarize the recent progress in insect trace conditioning on the behavioral and physiological level and emphasize similarities and differences compared to delay conditioning. Moreover, we examine proposed molecular and computational models and reassess different experimental approaches used for trace conditioning.

Comparative studies of trace elements in two kinds of human gallstones

International Nuclear Information System (INIS)

Vatankhah, S.; Moosavi, K.; Peyrovan, H.; Salimi, J.

2003-01-01

Structural composition of 11 trace elements with Z greater than 13 (Al, P, Si, K, Ca, Mn, Fe, Cu, Zn, Mo, I) was analyzed for the two main groups of human gallstones according to their cholesterol and pigment types by PIXE (Proton Induced X-ray Emission). In both types of stones, the shell and the center were analyzed separately. The gallstones were obtained from 12 patients in wide age group from 22 to 78 years of age during surgical operation. The results show relatively higher values of heavy elements for ages greater than 40. The values of phosphorus in cholesterol type stones are significantly higher than in those of pigment stones. The concentration of calcium in the center of stones is large in comparison with that in the shells. In this paper, a correlation between stone structure and trace elemental concentration has been presented. Comparison of the two essential types of stones (cholesterol and pigment) shows that the center of the pigment stones is very similar to that of the cholesterol type. (author)

Lectures on the Arthur-Selberg trace formula

CERN Document Server

Gelbart, Stephen

1996-01-01

The Arthur-Selberg trace formula is an equality between two kinds of traces: the geometric terms given by the conjugacy classes of a group and the spectral terms given by the induced representations. In general, these terms require a truncation in order to converge, which leads to an equality of truncated kernels. The formulas are difficult in general and even the case of GL(2) is nontrivial. The book gives proof of Arthur's trace formula of the 1970s and 1980s, with special attention given to GL(2). The problem is that when the truncated terms converge, they are also shown to be polynomial in the truncation variable and expressed as "weighted" orbital and "weighted" characters. In some important cases the trace formula takes on a simple form over G. The author gives some examples of this, and also some examples of Jacquet's relative trace formula. This work offers for the first time a simultaneous treatment of a general group with the case of GL(2). It also treats the trace formula with the example of Jacque...

Topological Hochschild homology and the Bass trace conjecture

DEFF Research Database (Denmark)

Berrick, A. J.; Hesselholt, Lars

2015-01-01

We use the methods of topological Hochschild homology to shed new light on groups satisfying the Bass trace conjecture. Factorization of the Hattori–Stallings rank map through the Bökstedt–Hsiang–Madsen cyclotomic trace map leads to Linnell's restriction on such groups. As a new consequence...

Trace formulae for arithmetical systems

International Nuclear Information System (INIS)

Bogomolny, E.B.; Georgeot, B.; Giannoni, M.J.; Schmit, C.

1992-09-01

For quantum problems on the pseudo-sphere generated by arithmetic groups there exist special trace formulae, called trace formulae for Hecke operators, which permit the reconstruction of wave functions from the knowledge of periodic orbits. After a short discussion of this subject, the Hecke operators trace formulae are presented for the Dirichlet problem on the modular billiard, which is a prototype of arithmetical systems. The results of numerical computations for these semiclassical type relations are in good agreement with the directly computed eigenfunctions. (author) 23 refs.; 2 figs

Measurements of transuranium trace amounts in solution. Bibliographic study

International Nuclear Information System (INIS)

Billon, A.; Gaudez, M.T.

1986-01-01

A critical study based on the data of the literature published up to 1984 has been carried out on the measurements of transuranian traces in solution. The general technical aspects of the dosage of transuranian traces in solution and of their speciations were initially reviewed. The second part is devoted to the detailed review of various methods in use in the laboratories. This work has been carried out in the framework of the MIRAGE (migration of radionuclides in the biosphere) Community project. 85 refs

Effects of a long-acting trace mineral rumen bolus supplement on growth performance, metabolic profiles, and trace mineral status of growing camels.

Science.gov (United States)

Alhidary, Ibrahim A; Abdelrahman, Mutassim M; Harron, Raafat M

2016-04-01

A study was conducted to evaluate the effects of a long-acting trace mineral rumen bolus (TMB) supplement on the productive performance, metabolic profiles, and trace mineral status of growing camels under natural grazing conditions. Fifteen 6-month-old growing male camels (average bodyweight 139.51 ± 26.49 kg) were used in a 150-day trial. Animals were individually housed in a shaded pen and randomly assigned to receive zero (control group, CON), one (TMB1), or two (TMB2) long-acting TMBs. Feed intake was measured weekly, and camels were weighed monthly. Blood samples were collected from all camels on days 1, 30, 60, 90, 120, and 150 to obtain metabolic profiles. Zinc, selenium, copper, cobalt, and manganese concentrations were determined in the diet, serum, and liver. In comparison with controls, giving camels one TMB increased the average daily gain (14.38%; P camels in the TMB2 group. These data indicate that TMB supplementation has positive effects on the growth performance and trace mineral profiles of camels. Different levels, sources, and synergistic combinations of trace minerals can be used in further studies to elucidate their abilities to increase productive variables as well as their availability and cost to the camel industry.

Generalised tally-based decoders for traitor tracing and group testing

NARCIS (Netherlands)

Skoric, B.; de Groot, W.

2015-01-01

We propose a new type of score function for Tardos traitor tracing codes. It is related to the recently introduced tally-based score function, but it utilizes more of the information available to the decoder. It does this by keeping track of sequences of symbols in the distributed codewords instead

Trace elements status of pulmonary tuberculosis patients compared with healthy voluntaries

International Nuclear Information System (INIS)

Moraes, Milena L. de; Ramalho, Daniela M.P.; Delogo, Karina N.; Miranda, Pryscila F.C.; Mesquita, Eliene D.D.; Kritski, Afranio L.; Oliveira, Martha M.; Canellas, Catarine G.L.; Lopes, Ricardo T.; Anjos, Marcelino J.

2011-01-01

Trace elements have important contribution to immune function. The objective of this study was to compare the Iron, Copper and Zinc levels of patients with active Pulmonary Tuberculosis (TB) and healthy subjects using X-ray Total Reflection Fluorescence Spectrometry. The study group was formed by men with active TB hospitalized on the Ary Parreiras State Institute of diseases of the chest and on the Santa Maria State Hospital, Rio de Janeiro, Brazil. The control group was formed by healthy men of Military Academy Fire Dom Pedro II, Rio de Janeiro, Brazil. The measurements of trace elements were performed at XRF beam line at Brazilian Synchrotron Light, Campinas, Sao Paulo. The results show that serum iron concentration was higher in control group than in study group. Besides that, serum copper concentration was higher in control group than in study group. According to the literature higher levels of copper are observed in infectious diseases like tuberculosis. In the case of the serum zinc concentration no statistical difference was observed between the two groups studied. (author)

Trace elements status of pulmonary tuberculosis patients compared with healthy voluntaries

Energy Technology Data Exchange (ETDEWEB)

Moraes, Milena L. de; Ramalho, Daniela M.P.; Delogo, Karina N.; Miranda, Pryscila F.C.; Mesquita, Eliene D.D.; Kritski, Afranio L.; Oliveira, Martha M. [Centro de Pesquisa em Tuberculose, Hospital Universitario Clementino Fraga Filho, Universidade Federal do Rio de Janeiro, RJ (Brazil); Canellas, Catarine G.L.; Lopes, Ricardo T., E-mail: ricardo@lin.ufrj.br [Laboratorio de Instrumentacao Nuclear, Programa de Engenharia Nuclear/COPPE UFRJ, RJ (Brazil); Anjos, Marcelino J., E-mail: marcelin@uerj.br [Departamento de Fisica Aplicada e Termodinamica - Instituto de Fisica Armando Dias Tavares. Universidade do Estado do Rio de Janeiro, RJ (Brazil)

2011-07-01

Trace elements have important contribution to immune function. The objective of this study was to compare the Iron, Copper and Zinc levels of patients with active Pulmonary Tuberculosis (TB) and healthy subjects using X-ray Total Reflection Fluorescence Spectrometry. The study group was formed by men with active TB hospitalized on the Ary Parreiras State Institute of diseases of the chest and on the Santa Maria State Hospital, Rio de Janeiro, Brazil. The control group was formed by healthy men of Military Academy Fire Dom Pedro II, Rio de Janeiro, Brazil. The measurements of trace elements were performed at XRF beam line at Brazilian Synchrotron Light, Campinas, Sao Paulo. The results show that serum iron concentration was higher in control group than in study group. Besides that, serum copper concentration was higher in control group than in study group. According to the literature higher levels of copper are observed in infectious diseases like tuberculosis. In the case of the serum zinc concentration no statistical difference was observed between the two groups studied. (author)

Double-trace deformations of conformal correlations

Science.gov (United States)

Giombi, Simone; Kirilin, Vladimir; Perlmutter, Eric

2018-02-01

Large N conformal field theories often admit unitary renormalization group flows triggered by double-trace deformations. We compute the change in scalar four-point functions under double-trace flow, to leading order in 1/ N. This has a simple dual in AdS, where the flow is implemented by a change of boundary conditions, and provides a physical interpretation of single-valued conformal partial waves. We extract the change in the conformal dimensions and three-point coefficients of infinite families of double-trace composite operators. Some of these quantities are found to be sign-definite under double-trace flow. As an application, we derive anomalous dimensions of spinning double-trace operators comprised of non-singlet constituents in the O( N) vector model.

Long-term prognosis of diabetic patients with myocardial infarction: relation to antidiabetic treatment regimen. The TRACE Study Group

DEFF Research Database (Denmark)

Gustafsson, I; Hildebrandt, P; Seibaek, M

2000-01-01

a higher prevalence of known cardiovascular disease. Even though the diabetic patients had the same frequency of ST-segment elevation on the electrocardiogram and the same admission delay, treatment with thrombolysis and aspirin was less frequently prescribed to the diabetic patients than to patients......AIMS: The present study was performed to evaluate pre-admission history, presentation, initial treatment and long-term mortality in patients with myocardial infarction and diabetes. METHODS AND RESULTS: Between 1990 and 1992, 6676 patients with acute myocardial infarction were screened for entry...... into the Trandolapril Cardiac Evaluation (TRACE) study. In this cohort 719 (11%) of the patients had a history of diabetes. Among the diabetic patients 19% were treated with insulin, 52% with oral hypoglycaemic agents and 29% with diet only. The diabetic patients were slightly older, more likely to be female and had...

pH-dependent release of trace elements including platinum group elements (PGEs) from gasoline and diesel catalysts

Science.gov (United States)

Sucha, Veronika; Mihaljevic, Martin; Ettler, Vojtech; Strnad, Ladislav

2014-05-01

The release of trace metals and platinum group elements (PGEs) from automobile exhaust catalysts represents a remarkable source of higly dispersed environmental contamination. Especially, PGEs have shown increasing research interest due to their possible bioaccessibility. In our research, we focused on leaching behaviour of trace metals from gasoline and diesel automobile catalysts. While catalysts for gasoline engines contain a mixture of Pt-Pd-Rh or Pd-Rh, catalysts for diesel engines are composed only of Pt. We used dust from two crushed gasoline and two crushed diesel catalysts (new and aged). The dust of gasoline catalysts contains significant concentrations of Pt (700 mg.kg-1), Pd (11 000 mg.kg-1) and Rh (700 mg.kg-1). And the dust of diesel catalysts are composed of Pt (3 900 mg.kg-1) and they contains negligible amounts of Pd dan Rh (leaching of trace metals from dust we used pH-stat leaching test according to the European standard CEN/TS 14997. The concentrations of cations: PGEs (Pt, Pd a Rh), K, Na, Ca, Mg, Al, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb, La and Ce were determined by inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectrometry (AAS), and anions: F-, Cl-, SO42- and NO3- by high-performance liquid chromatography. Although the dusts from catalysts were relatively stable to acid/base influence, the leaching of trace metals from catalysts showed a dependence on pH. Generally, the highest concentrations were released under acidic conditions. The leaching of PGEs was higher for Pt in diesel catalysts and for Pd and Rh in gasoline catalysts. The highest concentrations of Zn and Pb were observed in old catalysts. The rare earth metals were released more from gasoline catalysts. Catalysts particles represent health risk especially with respect to their PGEs contents.

The Role of Trace Elements in Tinnitus.

Science.gov (United States)

Yaşar, Mehmet; Şahin, Mehmet İlhan; Karakükçü, Çiğdem; Güneri, Erhan; Doğan, Murat; Sağıt, Mustafa

2017-03-01

In this study, we aimed to investigate the role of three trace elements, namely, zinc, copper, and lead, in tinnitus by analyzing the serum level of copper and lead and both the serum and tissue level of zinc. Eighty patients, who applied to outpatient otolaryngology clinic with the complaints of having tinnitus, and 28 healthy volunteers were included. High-frequency audiometry was performed, and participants who had hearing loss according to the pure tone average were excluded; tinnitus frequency and loudness were determined and tinnitus reaction questionnaire scores were obtained from the patients. Of all the participants, serum zinc, copper, and lead values were measured; moreover, zinc levels were examined in hair samples. The levels of trace elements were compared between tinnitus and control groups. The level of copper was found to be significantly lower in the tinnitus group (p = 0.02), but there was no significant difference between the groups in terms of the levels of zinc, neither in serum nor in hair, and lead in serum (p > 0.05). The lack of trace elements, especially that of "zinc," have been doubted for the etiopathogenesis of tinnitus in the literature; however, we only found copper levels to be low in patients having tinnitus.

Study of trace elements distribution in various tissues structures

International Nuclear Information System (INIS)

Kwiatek, W.M.; Marczewska, E.

1994-01-01

Many papers have been written during the past ten years about TE study in cancer and normal tissues describing the use of different methods for detection of trace elements. Concentration of TE depends strongly on the sample measured. However, according to our knowledge, the role of TE in cancerous tissue is still known. Therefore, we propose to perform an experiment which will hopefully given us more information about the relationship between the concentration of elements in different tissues. The developing industry localised near Cracow becomes a serious danger for health of it's inhabitants. The negative influence of the air pollution to the living organisms is seen not only in the nature but also in humans. Therefore we want to analyse the trace element contents in the air. Such investigation will give the information about the pollution level in the City. The pollution has its obvious negative influence to health and toxic element concentration level in blood. It is interesting to check if placenta plays an effective role in foetus protection against toxic metals. In order to study this problem, the trace element analysis of placenta tissues will be done by means of synchrotron microbeam. (author). 1 ref

ON A REDUCED CROSSED PRODUCT OF A GROUP BY A C*-ALGEBRA. THE CASES OF CONTINUOUS TRACE AND TYPE I REDUCED CROSSED PRODUCT

OpenAIRE

Daniel Tudor

2014-01-01

This paper analyzes two special cases of C* -algebras, the cases of universal crossed product and reduced crossed product of a group by a C* -algebra. In the hypothesis that the universal crossed product is a continuous trace C* -algebra or a type I C* -algebra, it is proved that the reduced crossed product is a continuous trace C* -algebra or, respectively, a type I C* -algebra. Moreover, these results can be extended in the case when the crossed products are obtained from a groupoid an...

studies on trace metal concentration pseudotolithus elongatus from ...

African Journals Online (AJOL)

DJFLEX

KEY WORDS: Trace metals, Lead Pollution, Pseudotolithus elongatus, Mbo coastal waters, ..... Analysis of soil heavy metal pollution and ... Pekey, H., Karakas, D., and Bakog'lu, M., 2004. Source apportionment of trace metals in the surface.

Speciation of trace elements in the environmental studies

International Nuclear Information System (INIS)

Reddy, A.V.R.

2012-01-01

Elements present at trace levels, often referred as trace elements, play an important role in the environment and in the functioning of life on our planet. Trace elements in environment present as free metal ions or incorporated into colloids or attached to particulate matter or exist in different physical and chemical forms. It is well established that some elements are highly toxic and some are essential, but can become toxic at higher doses. It is also now known that the forms of elements (speciation) and their amounts are more important than the chemical dose of the elements as their interaction depends on different species. For example, Cr(VI) ions are considered far more toxic than Cr(III), whereas As(III) is more toxic than As(V). Similarly, in the case of mercury, both methylmercury and inorganic mercury are toxic but they show different levels of toxicity. Thus the adverse effects depend on the nature of species of the elements and therefore speciation studies are of paramount importance in many areas like toxicology, environmental chemistry and geochemisty. In view of this, speciation studies is a challenge to analytical chemists as the measurement methodologies have to be carefully developed, validated and applied. The grand challenge is to obtain quality data ensuring traceability, as the data obtained will be used in modeling for predicting the environmental impacts. In this talk importance of speciation and challenges to environmental analytical chemists will be discussed along with the following three speciation studies on Cr, U and Hg which were carried out in our laboratories

Radiolabelled substrates for studying biological effects of trace contaminants

International Nuclear Information System (INIS)

1975-01-01

A programme of coordinated isotopic tracer-aided investigations of the biological side-effects of foreign chemical residues in food and agriculture, initiated in 1973, was reviewed. The current status of representative investigations from the point of view of techniques and priorities was assessed. Such investigations involved radioactive substrates for studying DNA injury and its repair; 14 C-labelled acetylcholine as substrate for measuring enzyme inhibition due to the presence of, or exposure to, anticholinesteratic contaminants; radioactive substrates as indication of side-effects in non-target organisms and of their comparative susceptibilities; radioactive substrates as indicators of persistence or biodegradability of trace contaminants of soil or water; and labelled pools for studying the biological side-effects of trace contaminants. Priorities were identified

Trace element composition of hair in the Italian population

International Nuclear Information System (INIS)

Clemente, G.F.; Cigna Rossi, L.

1979-01-01

The content of the trace elements Ag, Co, Cr, Cs, Fe, Hg, Ni, Rb, Sb, Sc, Se and Zn has been evaluated in hair samples collected from five different groups of subjects in Italy. All the measurements were performed by means of non-destructive neutron activation analysis of the hair samples that were carefully washed before analysis. In most of the samples the Cs, Rb and Sc content was below the detection limit of the analytical method. Each population group was formed of about five individuals of each sex, selected to be representative of the adult population living in a well-defined community. The five groups were chosen from distinct regions with different socio-economical living habits in order to detect the variability, if any, of the trace element burden among the Italian population. The trace element hair concentration of each subject was correlated with the trace element blood concentration and daily urinary excretion in order to differentiate the trace element content due to exogenous deposition on hair from that due to endogenous absorption routes. The results obtained show that the variability of the hair content among the various groups is strongly linked to local environmental factors. The histograms of the individual values of the hair concentration are given for all trace elements measured, together with a statistical analysis of all data. (author)

Epidemic contact tracing via communication traces.

Directory of Open Access Journals (Sweden)

Katayoun Farrahi

Full Text Available Traditional contact tracing relies on knowledge of the interpersonal network of physical interactions, where contagious outbreaks propagate. However, due to privacy constraints and noisy data assimilation, this network is generally difficult to reconstruct accurately. Communication traces obtained by mobile phones are known to be good proxies for the physical interaction network, and they may provide a valuable tool for contact tracing. Motivated by this assumption, we propose a model for contact tracing, where an infection is spreading in the physical interpersonal network, which can never be fully recovered; and contact tracing is occurring in a communication network which acts as a proxy for the first. We apply this dual model to a dataset covering 72 students over a 9 month period, for which both the physical interactions as well as the mobile communication traces are known. Our results suggest that a wide range of contact tracing strategies may significantly reduce the final size of the epidemic, by mainly affecting its peak of incidence. However, we find that for low overlap between the face-to-face and communication interaction network, contact tracing is only efficient at the beginning of the outbreak, due to rapidly increasing costs as the epidemic evolves. Overall, contact tracing via mobile phone communication traces may be a viable option to arrest contagious outbreaks.

Epidemic contact tracing via communication traces.

Science.gov (United States)

Farrahi, Katayoun; Emonet, Rémi; Cebrian, Manuel

2014-01-01

Traditional contact tracing relies on knowledge of the interpersonal network of physical interactions, where contagious outbreaks propagate. However, due to privacy constraints and noisy data assimilation, this network is generally difficult to reconstruct accurately. Communication traces obtained by mobile phones are known to be good proxies for the physical interaction network, and they may provide a valuable tool for contact tracing. Motivated by this assumption, we propose a model for contact tracing, where an infection is spreading in the physical interpersonal network, which can never be fully recovered; and contact tracing is occurring in a communication network which acts as a proxy for the first. We apply this dual model to a dataset covering 72 students over a 9 month period, for which both the physical interactions as well as the mobile communication traces are known. Our results suggest that a wide range of contact tracing strategies may significantly reduce the final size of the epidemic, by mainly affecting its peak of incidence. However, we find that for low overlap between the face-to-face and communication interaction network, contact tracing is only efficient at the beginning of the outbreak, due to rapidly increasing costs as the epidemic evolves. Overall, contact tracing via mobile phone communication traces may be a viable option to arrest contagious outbreaks.

Selected Trace Element Concentrations in Peat Used for Cosmetic Production – A Case Study from Southern Poland

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Glina Bartłomiej

2016-12-01

Full Text Available The aim of the study was to assess the concentration of selected trace elements in organic soils used as a source to obtain a unique peat extract for cosmetics production. Peat material for laboratory analysis were collected from fen peatland located in the Prosna River Valley (Borek village. Studied peatland is managed by “Torf Corporation” company as a source of material to obtain peat extract for cosmetics production. In the collected soil samples (four soil profiles Zn, Cu and Pb concentrations were determined by using atomic absorption spectrometer SpectraAA 220 (Varian, after acid digestion. Obtained results showed that the highest concentrations of selected trace elements were recorded in the surface horizons of organic soils. This fact might be the results of Prosna river flooding or air deposition. Howevere, according to the new Polish regulations (Ordinance of the Minister for Environment 01.09.2016 - the way of conducting contamination assessment of the earth surface, the content of trace elements in the examined soils was greatly belowe the permissible limit for areas from group IV (mine lands. Thus, described soils are proper to obtain peat extract used as a component in cosmetic production.

Contact tracing of tuberculosis: a systematic review of transmission modelling studies.

Directory of Open Access Journals (Sweden)

Matt Begun

Full Text Available The WHO recommended intervention of Directly Observed Treatment, Short-course (DOTS appears to have been less successful than expected in reducing the burden of TB in some high prevalence settings. One strategy for enhancing DOTS is incorporating active case-finding through screening contacts of TB patients as widely used in low-prevalence settings. Predictive models that incorporate population-level effects on transmission provide one means of predicting impacts of such interventions. We aim to identify all TB transmission modelling studies addressing contact tracing and to describe and critically assess their modelling assumptions, parameter choices and relevance to policy. We searched MEDLINE, SCOPUS, COMPENDEX, Google Scholar and Web of Science databases for relevant English language publications up to February 2012. Of the 1285 studies identified, only 5 studies met our inclusion criteria of models of TB transmission dynamics in human populations designed to incorporate contact tracing as an intervention. Detailed implementation of contact processes was only present in two studies, while only one study presented a model for a high prevalence, developing world setting. Some use of relevant data for parameter estimation was made in each study however validation of the predicted impact of interventions was not attempted in any of the studies. Despite a large body of literature on TB transmission modelling, few published studies incorporate contact tracing. There is considerable scope for future analyses to make better use of data and to apply individual based models to facilitate more realistic patterns of infectious contact. Combined with a focus on high burden settings this would greatly increase the potential for models to inform the use of contract tracing as a TB control policy. Our findings highlight the potential for collaborative work between clinicians, epidemiologists and modellers to gather data required to enhance model development

Contact tracing of tuberculosis: a systematic review of transmission modelling studies.

Science.gov (United States)

Begun, Matt; Newall, Anthony T; Marks, Guy B; Wood, James G

2013-01-01

The WHO recommended intervention of Directly Observed Treatment, Short-course (DOTS) appears to have been less successful than expected in reducing the burden of TB in some high prevalence settings. One strategy for enhancing DOTS is incorporating active case-finding through screening contacts of TB patients as widely used in low-prevalence settings. Predictive models that incorporate population-level effects on transmission provide one means of predicting impacts of such interventions. We aim to identify all TB transmission modelling studies addressing contact tracing and to describe and critically assess their modelling assumptions, parameter choices and relevance to policy. We searched MEDLINE, SCOPUS, COMPENDEX, Google Scholar and Web of Science databases for relevant English language publications up to February 2012. Of the 1285 studies identified, only 5 studies met our inclusion criteria of models of TB transmission dynamics in human populations designed to incorporate contact tracing as an intervention. Detailed implementation of contact processes was only present in two studies, while only one study presented a model for a high prevalence, developing world setting. Some use of relevant data for parameter estimation was made in each study however validation of the predicted impact of interventions was not attempted in any of the studies. Despite a large body of literature on TB transmission modelling, few published studies incorporate contact tracing. There is considerable scope for future analyses to make better use of data and to apply individual based models to facilitate more realistic patterns of infectious contact. Combined with a focus on high burden settings this would greatly increase the potential for models to inform the use of contract tracing as a TB control policy. Our findings highlight the potential for collaborative work between clinicians, epidemiologists and modellers to gather data required to enhance model development and validation and

HAIR HEAVY METAL AND ESSENTIAL TRACE ELEMENT CONCENTRATION IN CHILDREN WITH AUTISM SPECTRUM DISORDER.

Science.gov (United States)

Tabatadze, T; Zhorzholiani, L; Kherkheulidze, M; Kandelaki, E; Ivanashvili, T

2015-11-01

Our study aims evaluation of level of essential trace elements and heavy metals in the hair samples of children with autistic spectrum disorder (ASD) and identification of changes that are associated with autistic spectrum disorders. Case-control study was conducted at Child Development Center of Iashvili Children's Central Hospital (LD).We studied 60 children aged from 4 to 5 years old. The concentrations of 28 elements among (Ca,Zn, K, Fe, Cu, Se, Mn, Cr, S, Br, Cl, Co, Ag, V, Ni, Rb, Mo, Sr, Ti, Ba, Pb, As, Hg, Cd, Sb, Zr, Sn, Bi) them trace elements and toxic metals) were determined in scalp hair samples of children (n=30) with autistic spectrum disorder (ASD) and from control group of healthy children (n=30) with matched sex and age. Micro-elemental status was detected in the hair, with roentgen-fluorescence spectrometer method (Method MBИ 081/12-4502-000, Apparatus ALVAX- CIP, USA - UKRAIN) .To achieve the similarity of study and control groups, pre and postnatal as well as family and social history were assessed and similar groups were selected. Children with genetic problems, malnourished children, children from families with social problems were excluded from the study. The diagnosis of ASD were performed by pediatrician and psychologist (using M-CHAT and ADOS) according to DSM IV (Diagnostic and Statistical Manual of Mental Disorders from the American Psychiatric association) criteria. The study was statistically analyzed using computer program SPSS 19. Deficiencies of essential trace microelements revealed in both group, but there was significant difference between control and studied groups. The most deficient element was zinc (92% in target and 20% in control), then - manganese (55% and 8%) and selenium (38% and 4%). In case of cooper study revealed excess concentration of this element only in target group in 50% of cases. The contaminations to heavy metals were detected in case of lead (78% and 16), mercury (43% and 10%) and cadmium (38% and 8%). The

Trace elements in the atmosphere over South Africa

International Nuclear Information System (INIS)

Wells, R.B.; Van As, D.

1976-01-01

Natural sources of trace elements in the atmosphere are suspended soil particles, the evaporation of sea spray and smoke from veld fires. In urban and industrialised areas the main sources are fossil-fuel power plants, metallurgical smelters, blast furnaces, incinerators, automobiles, fossil-fueled locomotives and open fires in the Black townships. Often a source can be recognised by the relative concentrations of particular trace elements. A monitoring programme was established in 1974 by the Air Pollution Research Group of the CSIR and the Isotope and Radiation Division of the Atomic Energy Board in order to study the levels of trace elements in urban areas such as Johannesburg, Cape Town, and Durban, to measure the effects of industrialisation on trace elements levels in developing areas such as Richards Bay and Saldanha Bay and also to determine baseline values in rural areas. Extremely sensitive analytical techniques, e.g. neutron activation and atomic absorption were used for the analyses of filter samples. Methods of sampling and analysis are discussed and the preliminary results of this programme are presented

Influence of age on the prognostic importance of left ventricular dysfunction and congestive heart failure on long-term survival after acute myocardial infarction. TRACE Study Group

DEFF Research Database (Denmark)

Køber, L; Torp-Pedersen, C; Ottesen, M

1996-01-01

for entry into the TRAndolapril Cardiac Evaluation (TRACE) study. Medical history, echocardiographic estimation of LV systolic function determined as wall motion index, infarct complications, and survival were documented for all patients. To study the importance of congestive heart failure and wall motion...... dysfunction was more pronounced in the elderly than in the young....

The reincorporation and redistribution of trace geoforensic particulates on clothing: an introductory study.

Science.gov (United States)

Morgan, R M; French, J C; O'Donnell, L; Bull, P A

2010-12-01

Two experimental studies were undertaken to investigate the processes of reincorporation and redistribution of trace evidence on garments when worn by a suspect or a victim (reincorporation) or after the garments have been seized and packaged for subsequent forensic analysis (redistribution). The first experiment utilised UV powder, an established proxy for geoforensic trace particulates and the second experiment utilised daffodil pollen transferred onto garments under conditions that mimicked forensic reality. It was demonstrated that reincorporation of trace particulates occurs from upper to lower parts of the same garment and also from upper garments to lower garments. Reincorporation also occurred to all areas of the lower garments, however the highest concentration of particulates was found to be the lap area of the jeans. Particulates also tended to be preserved around technical details such as stitching or relief design features of the garments. Thus the decay of particulates after a contact has been made does not necessarily involve a loss of those particulates from the entire system. These findings have implications for the interpretation of trace evidence when seeking to establish the source of initial contacts or the chronology of pertinent events. The second study demonstrated that folding and packaging items of clothing leads to a redistribution of any trace particulate evidence that is present thereby eliciting an alteration in the spatial distribution of that evidence. There is therefore a necessity to take the context of trace evidence into account and also to follow protocols that are sensitive to these aspects of trace evidence behaviour as a failure to do so may have consequences for the correct interpretation of such evidence. Copyright © 2010 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

Considerations on aims and approaches of the study on the transport of trace elements in a river watershed

International Nuclear Information System (INIS)

Matsunaga, Takeshi

2002-10-01

Concerning the study subject on the transport of trace, toxic chemicals and radioactive elements in a river watershed, that has been developed in the Research Group for Terrestrial Environment, its aims and methodological approaches have been discussed in the light of related social and technological aspects of today. It is stressed that a study of the transport of radionuclides originated from a nuclear installation is needed to assess the physiological impact and to provide appropriate countermeasures in case of an accident. A numerical model is prerequisite for these objectives and to be keenly developed. The outcome of the modeling will be also important for a quantitative analysis of cycling of trace toxic elements in the atmosphere- lithosphere-hydrosphere, and also of the mechanisms of contamination of the surface aquatic environment. Accordingly, the study will contribute to the key issues stated in the national programs of science and technologies such as conservation of the natural and living environment. The present large consumption of metals and metalloids may cause an extensive contamination in the future. The study can provide solutions to the problems associated with metals and metalloids, because their environmental behavior resembles to that of radionuclides. From a methodological aspect, an importance of a direct investigation of physicochemical forms of trace, toxic elements must be stressed. A simultaneous use of experimental methods and chemical modeling to study the physico-chemical forms will be a good exemption to be realized hereafter. Experimentally, partitioning between solid and liquid phases using radioisotopes, and identification of solid species using various X-ray spectrometric techniques, for example, have been recognized very promising to investigate physico-chemical form of trace elements. These techniques are much ought to the nuclear sciences, suggesting further possible contribution of the nuclear sciences to the questions of

Study of osteoporosis through the measurement of bone mineral density and trace elements

International Nuclear Information System (INIS)

Aras, N.K.; Yilmaz, G.; Alkanl, S.; Korkusuz, F.; Ungan, M.; Kuscu, L.; Laleli, Y.; Eksioglu, F.; Sepici, B.; Gunel, U.

2000-01-01

The main purpose of this study was to establish a relation, if any, between bone mineral density, BMD, of the healthy Turkish population of the ages between 15 and 50 with social and demographic information, family history of fractures, personal and inherited characteristic, smoking and alcohol habit, history of fertility, level of physical activity, food consumption especially trace elements and other variables. Most of these relations were discussed in the last RCM in San Diego, CA, October 7-10,1996. Since then we have concentrated our work on more BMD and trace element measurements in bone. To this end, bone mineral density measurements, trace element studies, neutron activation analysis, fluoride analysis and atomic absorption analysis were undertaken and resulting data were analysed

The effects of low levels of dietary trace minerals on the plasma levels, faecal excretion health and performance of pigs in a hot African climate

Directory of Open Access Journals (Sweden)

M.H. Boma

2009-09-01

Full Text Available The present study was performed in order to evaluate the effects of lower than usual industry levels of dietary trace minerals on plasma levels, faecal excretion, performance, mortality and morbidity in growing-finishing pigs in a hot African climate. Group 1 (n =100 pigs received a diet with common industry levels of trace minerals. Group 2 (n =100 pigs received reduced dietary trace mineral levels but were fed the same basic diet as Group 1. Mortality, morbidity, pig performance and carcass measurements were evaluated. Two pigs in Group 1 and three pigs in Group 2 died. Thirteen pigs in Group 1 and 27 pigs in Group 2 were medically treated (P 0.05 by the dietary levels of these trace minerals. Plasma trace mineral concentrations were not affected by the dietary treatment.

Evaluation of serum trace element, biochemical and hematological data of a healthy elderly group residing in Sao Paulo city, Brazil

International Nuclear Information System (INIS)

Saiki, M.; Vasconcellos, M.B.A.; Sumita, N.M.; Jaluul, O.; Jacob-Filho, W.

2009-01-01

In this study, blood serum trace elements, biochemical and hematological parameters were obtained to assess the health status of an elderly population residing in Sao Paulo city, SP, Brazil. Results obtained showed that more than 93% of the studied individuals presented most of the serum trace element concentrations and of the hematological and biochemical data within the reference values used in clinical laboratories. However, the percentage of elderly presenting recommended low density lipoprotein (LDL) cholesterol concentrations was low (70%). The study indicated positive correlation between the concentrations of Zn and LDL-cholesterol (p<0.06). (author)

Study in Malaysia on ingestion and organ content of trace elements of importance in radiological protection

International Nuclear Information System (INIS)

Zawiah, H.; Khalik Haji Wood, A.; Shahrom, A.W.; Halim Mansar, A.

1998-01-01

Involvement in the Reference Asian man project, Phase 2 began at the project, formulation meeting in Hitachinaka City, Japan in February 1995. The objective of the project is to look into the ingestion and organ content of trace elements of importance in radiological protection. The data on ingestion of radionuclides from diet and deposition in tissues are important for estimating internal dose for radiation protection. The meeting agreed the elements of primary interest are caesium, iodine, strontium, thorium and uranium in samples of representative diets and autopsy specimens of liver, muscle, thyroid, bone, and kidney. This report will highlight the methodology for implementation of the project including defining the study groups, sampling duplicate diet and autopsy specimens and the analytical techniques involved. Emphasis will be given to nuclear-related analytical technique (NAA) together with a complementary technique (AAS) available in our institution. Some data on trace element contents of local marine and fresh water fishes and milk was reported. Included also a brief discussion on drinking water quality in Malaysia and some information on related studies available. The information on drinking water will be very useful to the present study since water is part of daily diet. (author)

Ichnotaxa for bite traces of thetrapods : A new area of research or a total waste of time?

DEFF Research Database (Denmark)

Jacobsen, Aase Roland; Bromley, Richard Granville

to the naming of biting trace fossils in bone substrates. Study of tetrapod bite trace fossils has revealed feeding behaviour, jaw mechanism, face-biting behaviour, social behaviour etc., as well as palaeoenvironmental conditions. But should naming of scratches and holes produced by teeth be considered...... a worthless waste of time? Is naming of this group of trace fossils considered a productive move? We have extended this work, suggesting new ichnotaxa for bite traces to focus on their potential value for identifying the tracemaker and thereby feeding behaviour. Bite traces also have a great potential...

Study on correlation of trace elements in human hair and internal organs by nuclear methods

International Nuclear Information System (INIS)

Cheng Yuandi; Zhuang Guisun; Zhang Yuanxun

1993-01-01

Autopsy samples from 24 human males, aged 35-60 years were collected from Shanghai, People's Republic of China, to study possible relationships between the trace element content in hair and internal tissues. Samples of hair, kidney-cortex and lung were collected and analyzed. A radiochemical neutron activation analysis (RNAA) procedure was developed based on a simple group extraction scheme using zinc-diethyl dithiocarbamate and methyl-isobutyl ketone-iodide. The trace elements As, Cd, Hg, Cu and Zn were measured following this procedure. In addition, the elements Se, Na, Mg, Cl, Br, S, Cr, Co, and Rb were determined using instrumental neutron activation analysis (INAA). The reliability of the analytical procedures were checked analyzing several biological reference materials, such as IAEA-H-8 Horse Kidney, NBS-SRM-1573 Tomato Leaves and NIES-5 Human Hair. The results showed a larger concentration variability for As, Cd and Hg than for Cu, Se and Zn. Some significant positive correlations were found for some elements among different tissues. (author). 15 refs, 22 figs, 4 tabs

Studies of trace element imbalances in Alzheimer's disease using sequential NAA

International Nuclear Information System (INIS)

Ehmann, W.D.; Markesbery, W.R.; Thompson, C.M.; Vance, D.E.; Mao, Y.

1986-01-01

Evidence has accumulated in the literature that trace elements may be implicated in the etiology of Alzheimer's disease (AD) and other age-related neurological diseases. Even if elemental imbalances do not prove to be causative factors, observed perturbations may be markers that could aid in diagnosis, or help elucidate pathological processes. In this paper the authors present new data for trace element levels in three areas of the human brain most severely affected by AD (hippocampus, amygdala, and nucleus basalis) and in AD hair and nail samples. In some cases the specific imbalances seen previously in the bulk brain analyses are amplified in these regions. Elevated bromine levels seen in AD brain are also observed in AD hair and nail. Significant alkali metal and mercury imbalances with respect to controls occur in AD nail samples. The role of these trace element alterations in the etiology of AD has still not been determined. However, some possible physiological effects include: membrane dysfunction (alkali metals), enzyme inhibition (mercury and bromine), and interference with neurotransmitter functions (mercury, bromine, and alkali metals). The simultaneous multielement capability of this sequential NAA procedure also permits interelement correlation studies. Elemental associations may help identify potential environmental factors that could contribute to the observed trace element imbalances

PIXE analysis for bioaccumulation studies of trace elements

International Nuclear Information System (INIS)

Iwata, Y.; Satoh, A.; Sasaki, Y.; Ito, R.; Kuramachi, K.

2005-01-01

Bioaccumulation by micro-alga in the ocean was simulated in nutritive seawater containing known amounts of trace metals, and the concentration factors for Fe, Zn and Cd were measured by PIXE. Trace transition metals in nearshore seawater were removed by Chelex-100. Then a culture solution was prepared by adding known amounts of trace metals and nutritive salts to the purified seawater. Marine micro-algae (Nannochloropsis sp., and Phaeodactylum sp.,) were purely cultured in the culture solution. An interested metal ion was added to the culture solution (0.01-5.0 mg/l). Alga in 10 ml of the culture solution was collected on a polycarbonate filter (pore size: 1.0 ) by suction filtration and subjected to 2.9 MeV proton bombardment. Na, Mg, Al, Si, P, S, Cl, K, Ca, Cr, Mn, Fe, Zn and Cd were simultaneously determined. PIXE multi-element analysis was possible using less than 1 mg of analytical sample. The quantity of the metal in the alga was increased in proportion to the concentration in the culture solution. The concentration factors for Zn, Fe and Cd were measured, e.g., 10200 ± 300 ml/g to Zn for Phaeodactylum. The trend of the affinity for the trace metals in the case of Nannochloropsis was Fe 3+ > Zn 2+ > Pb 2+ > Cd 2+ . (author)

Comparison of serum trace element levels in patients with or without pre-eclampsia

Directory of Open Access Journals (Sweden)

Leila Farzin

2012-01-01

Full Text Available Objective: In developing countries, nutritional deficiency of essential trace elements is a common health problem, particularly among pregnant women because of increased requirements of various nutrients. Accordingly, this study was initiated to compare trace elements status in women with or without pre-eclampsia. Materials and Methods: In this study, serum trace elements including zinc (Zn, selenium (Se, copper (Cu, calcium (Ca and magnesium (Mg were determined by using atomic absorption spectrometry (AAS in 60 patients and 60 healthy subjects. Results: There was no significant difference in the values of Cu between two groups (P > 0.05. A significant difference in Zn, Se, Ca and Mg levels were observed between patients with pre-eclampsia and control group (P 0.05. Conclusion: Our findings indicate that the levels of Zn, Se, Ca and Mg are significantly altered in pregnant women with pre-eclampsia. This research shows that these deficiencies can not due to hemodilution.

Trace elements in cocoa solids and chocolate: an ICPMS study.

Science.gov (United States)

Yanus, Rinat Levi; Sela, Hagit; Borojovich, Eitan J C; Zakon, Yevgeni; Saphier, Magal; Nikolski, Andrey; Gutflais, Efi; Lorber, Avraham; Karpas, Zeev

2014-02-01

The concentrations of eight trace elements: lead (Pb), cadmium (Cd), chromium (Cr), manganese (Mn), cobalt (Co), arsenic (As), bismuth (Bi) and molybdenum (Mo), in chocolate, cocoa beans and products were studied by ICPMS. The study examined chocolate samples from different brands and countries with different concentrations of cocoa solids from each brand. The samples were digested and filtered to remove lipids and indium was used as an internal standard to correct matrix effects. A linear correlation was found between the level of several trace elements in chocolate and the cocoa solids content. Significant levels of Bi and As were found in the cocoa bean shells but not in the cocoa bean and chocolate. This may be attributed to environmental contamination. The presence of other elements was attributed to the manufacturing processes of cocoa and chocolate products. Children, who are big consumers of chocolates, may be at risk of exceeding the daily limit of lead; whereas one 10 g cube of dark chocolate may contain as much as 20% of the daily lead oral limit. Moreover chocolate may not be the only source of lead in their nutrition. For adults there is almost no risk of exceeding daily limits for trace metals ingestion because their digestive absorption of metals is very poor. © 2013 Published by Elsevier B.V.

Characterisation of airborne particles in the assessment of air quality: a case study for trace metal determination

International Nuclear Information System (INIS)

Norhayati Mohd Tahir; Poh Seng Chee; Suhaimi Suratman; Noor Azhar Mohamed Shazili; Suhaimi Hamzah; Abd Khalik Wood; Syamsiah Abd Rahman; Mhd Radzi Abas

2005-01-01

A study to determine the concentration of total suspended particulate (TSP) and trace metals concentration in the atmospheric particulate was done in Kuala Terengganu town. TSP was collected using high volume sampler. The sampled filter paper were subjected to microwave assisted acid digestion and the metals were determined using inductive couple plasma with optical emission spectrophotometer (ICP-OES). Results indicated a significant spatial variation but generally the TSP concentrations recorded in this study are still below the recommended Malaysia guideline for TSP. Some of the elemental composition of particulate aerosol is clearly correlation and enrichment analyses, the elements could be grouped into two; Pb, Cd and Zn group could be related to the vehicular emission sources whist the Al, Fe, Mn and Cr group appears to be crustal origin. It can also be concluded that the levels of Pb, Cd and Zn in the study area are generally lower than other cities in Malaysia. (Author)

Traces of Drosophila Memory

Science.gov (United States)

Davis, Ronald L.

2012-01-01

Summary Studies using functional cellullar imaging of living flies have identified six memory traces that form in the olfactory nervous system after conditioning with odors. These traces occur in distinct nodes of the olfactory nervous system, form and disappear across different windows of time, and are detected in the imaged neurons as increased calcium influx or synaptic release in response to the conditioned odor. Three traces form at, or near acquisition and co-exist with short-term behavioral memory. One trace forms with a delay after learning and co-exists with intermediate-term behavioral memory. Two traces form many hours after acquisition and co-exist with long-term behavioral memory. The transient memory traces may support behavior across the time-windows of their existence. The experimental approaches for dissecting memory formation in the fly, ranging from the molecular to the systems, make it an ideal system for dissecting the logic by which the nervous system organizes and stores different temporal forms of memory. PMID:21482352

Trace element studies in bioenvironmental samples using 3-MeV protons

International Nuclear Information System (INIS)

Walter, R.L.; Willis, R.D.; Gutknecht, W.F.

1974-01-01

Trace metal compositions of a wide range of biological, environmental, medical and clinical samples were investigated using proton-induced x-ray emission analysis (PIXEA). The x-rays were detected with a Si(Li) detector and spectra from over 3000 irradiations have been recorded on magnetic tape. The chi 2 fitting code TRACE developed at our laboratory was used in a semi-automatic mode to extract abundances of elements from S to Cd. Various methods of overcoming analytical problems and specimen preparation difficulties are reported. Results from some samples for typical studies are illustrated along with the reasons for interest in the sample types

Present and Future Challenges in Trace and Ultra-Trace Analysis

International Nuclear Information System (INIS)

Toulhoat, P.

2005-01-01

The analysis of trace and ultra-trace elements is continuously stimulating the progress in analytical chemistry. Environmental chemistry, radiochemistry, biology, health, agri-food are prescribers of trace analyses, with continuously increasing exigencies: lowering detection limits, lowering costs and analysis time, improving the quality of analytical information. Precise data about the chemical identity and chemical environment of analytes are now requested. Such pieces of information, beyond simple numerical data and confidence intervals, are necessary to understand studied systems, and to predict their evolution. From environmental contamination cases, one can envisage the various aspects of a problem, with for each of them its own exigencies and specificities in terms of analytical methods and approaches. The detection of traces and ultra-traces of actinides and fission products has been recently revisited and stimulates new technological developments (non proliferation issues, waste management). Data on their speciation in geological and biological media are essential for evaluating the safety of nuclear waste repositories. Various techniques are now used to determine speciation in liquid samples or on surfaces, with tremendous spatial resolutions or sensitivities. A new revolution in analytical chemistry is expected with the development of micro- or nano-analytical technologies. (author)

An Automated Anion-Exchange Method forthe Selective Sorption of five Groups ofTrace Elements in Neutron-IrradiatedBiological Material

International Nuclear Information System (INIS)

Samsahl, K.

1966-02-01

An anion-exchange method based on fast selective sorption steps from mixtures of sulfuric, hydrobromic, and hydrochloric acid solutions has been developed for the separation of five different groups of radioactive trace elements in neutron-irradiated biological material. The separations are performed automatically with a simple proportioning pump apparatus. The apparatus allows the exact adjustment of influent solutions to the series of ion-exchange columns. The practical application of the method is described in detail. The successful use of the method is practically independent on the level of Na activity present in the sample

Mercury levels in defined Italian population groups

International Nuclear Information System (INIS)

Ingrao, G.; Belloni, P.

1991-01-01

Our group conducts its research activity in the Department AMB-BIO (Biological and Sanitary Effect of Toxic Agents) of ENEA (National Committee for Research and Development of Nuclear and Alternative Energy) at the research centre of Casaccia. The food chain is the main pathway leading to humans for most of the trace elements. The research, therefore, has been directed mainly towards the study of the variability of the trace element content in the Italian diet. This programme aims at assessing the adequacy of the essential trace elements ingestion, and to verify that the ingestion of toxic trace elements is below the recommended values. Part of this research was conducted in the frame of the IAEA CRP on ''Human daily Intakes of Nutritionally Important Trace Elements as Measured by Nuclear and Other Techniques''. Studies carried out by the National Institute of Nutrition and FAO have shown that there are some population groups having a fish consumption significantly higher than the average value for the Italian population. These groups are usually found in coastal towns were fishing is one of the main occupation and generally includes fishermen, fish dealers, restaurant workers and their families. A pilot study was conducted in one of these towns, Bagnara Calabra in the South of Italy, where the average fish consumption is 27.1 kg per year, which is more than twice the national average. The results have shown that the mercury concentration in the diet is significantly higher than in other Italian locations, the mercury levels in blood and hair sample in these subjects are also significantly higher than the values reported for subjects of the general Italian population. 6 refs

Muscarinic receptors in amygdala control trace fear conditioning.

Directory of Open Access Journals (Sweden)

Amber N Baysinger

Full Text Available Intelligent behavior requires transient memory, which entails the ability to retain information over short time periods. A newly-emerging hypothesis posits that endogenous persistent firing (EPF is the neurophysiological foundation for aspects or types of transient memory. EPF is enabled by the activation of muscarinic acetylcholine receptors (mAChRs and is triggered by suprathreshold stimulation. EPF occurs in several brain regions, including the lateral amygdala (LA. The present study examined the role of amygdalar mAChRs in trace fear conditioning, a paradigm that requires transient memory. If mAChR-dependent EPF selectively supports transient memory, then blocking amygdalar mAChRs should impair trace conditioning, while sparing delay and context conditioning, which presumably do not rely upon transient memory. To test the EPF hypothesis, LA was bilaterally infused, prior to trace or delay conditioning, with either a mAChR antagonist (scopolamine or saline. Computerized video analysis quantified the amount of freezing elicited by the cue and by the training context. Scopolamine infusion profoundly reduced freezing in the trace conditioning group but had no significant effect on delay or context conditioning. This pattern of results was uniquely anticipated by the EPF hypothesis. The present findings are discussed in terms of a systems-level theory of how EPF in LA and several other brain regions might help support trace fear conditioning.

Muscarinic receptors in amygdala control trace fear conditioning.

Science.gov (United States)

Baysinger, Amber N; Kent, Brianne A; Brown, Thomas H

2012-01-01

Intelligent behavior requires transient memory, which entails the ability to retain information over short time periods. A newly-emerging hypothesis posits that endogenous persistent firing (EPF) is the neurophysiological foundation for aspects or types of transient memory. EPF is enabled by the activation of muscarinic acetylcholine receptors (mAChRs) and is triggered by suprathreshold stimulation. EPF occurs in several brain regions, including the lateral amygdala (LA). The present study examined the role of amygdalar mAChRs in trace fear conditioning, a paradigm that requires transient memory. If mAChR-dependent EPF selectively supports transient memory, then blocking amygdalar mAChRs should impair trace conditioning, while sparing delay and context conditioning, which presumably do not rely upon transient memory. To test the EPF hypothesis, LA was bilaterally infused, prior to trace or delay conditioning, with either a mAChR antagonist (scopolamine) or saline. Computerized video analysis quantified the amount of freezing elicited by the cue and by the training context. Scopolamine infusion profoundly reduced freezing in the trace conditioning group but had no significant effect on delay or context conditioning. This pattern of results was uniquely anticipated by the EPF hypothesis. The present findings are discussed in terms of a systems-level theory of how EPF in LA and several other brain regions might help support trace fear conditioning.

Study of particle size and trace metal distribution in atmospheric aerosols of islamabad

International Nuclear Information System (INIS)

Shah, M.H.; Shaheen, N.

2009-01-01

Atmospheric aerosol samples were collected on glass fibre filters using high volume air samplers Half of each aerosol sample was solubilized in nitric acid/hydrochloric acid based wet digestion method and the concentration of trace metals was determined through flame atomic absorption spectrophotometer. Among the eight trace metals analyzed, mean concentration recorded for Zn (844 ng/m3), Fe (642 ng/m3) and Pb (253 ng/m3), was found to be higher than mean levels of Mn, Cr and Co. The size distribution of the collected particulate samples was carried out on mastersizer, which revealed PM/sub 100-10/ as the major fraction (55 %) followed by PM/sub 2.5-10/ (28 %). The correlation study evidenced a strong tendency of trace metals to be associated with fine particulate fractions. The atmospheric trace metal levels showed that the mean metal concentrations in the atmosphere of Islamabad are far higher than background and European urban sites mainly due to the anthropogenic emissions. (author)

Study of trace element correlations with drought tolerance in different sorghum genotypes using Energy Dispersive X-Rays Fluorescence (EDXRF) technique

International Nuclear Information System (INIS)

Abu Assar, A.H.; Joseph, Daisy; Choudhury, R.K.; Saxena, A.; Suprasanna, P.; Bapat, V.A.

2000-01-01

Drought tolerant and susceptible genotypes of sorghum plants were analysed by Energy Dispersive X-Ray Fluorescence (EDXRF) technique to study the correlation of trace elements with drought tolerance capacities for sorghum plants. Samples prepared from mature seeds, young seedlings and old plants were analyzed using 109 Cd radioisotope source and a Si(Li) semiconductor detector of resolution 170 eV for 5.9 keV Mn K α X-ray. The elements such as K, Fe, Cu, Zn, Rb and Sr and Y were seen to be present in varying concentrations in different samples. The trace element profile in the seeds of 11 genotypes and in seedlings (young and old) of four sorghum genotypes that were studied exhibited considerable variation in their concentrations. Some seed genotypes showed the presence of Hg in small amounts. It was observed that in most of the genotypes (seeds), K and Fe concentrations were more in the tolerant genotype as compared to the susceptible type. Concentration of Fe decreased with maturity in the tolerant group while it increased with maturity in the susceptible group. The genotype Arfa Gadamak (AG) showed a distinct abnormality in its young seedling with high level of Zn. (author)

Studies on chelation properties of ampicillin with trace metal ions and comparison with penicillin complexes

International Nuclear Information System (INIS)

Rehmani, F.S.; Hameed, W.

2003-01-01

The penicillin is highly effective antibiotic with extremely wide margin of safety. Ampicillin e is the penicillin group of antibiotic in which side chain is phenyl group i.e. D-amino benzyl penicillin. The side chain determines many of anti bacterial and pharmacological characteristics. They inhibit the protein synthesis in bacterial cell wall. The chelating properties of the antibiotic may be used in the metal transport across the membrane. The present investigations are helpful in drug metabolism and their effects on minerals contents of the body. The complex formation between Ampicillin and penicillin with trace metal ions such as Fe(III), Cr(III), Al(III), Mn(II), Ni(II), Co(II), Ca(II), Mg(II), Cu(III) and Zn(II) were studied by potentiometric titrations and spectrophotometric methods. Stoichiometry of these complexes were studied by mole ratio method. It was found that the Fe(III) and Cu(II) ions form most stable complexes near physiological pH and the mole ratio was 1:1. (author)

Molybdenite Mineral Evolution: A Study Of Trace Elements Through Time

Science.gov (United States)

McMillan, M. M.; Downs, R. T.; Stein, H. J.; Zimmerman, A.; Beitscher, B. A.; Sverjensky, D. A.; Papineau, D.; Armstrong, J. T.; Hazen, R. M.

2010-12-01

Mineral evolution explores changes through time in Earth’s near-surface mineralogy, including diversity of species, relative abundances of species, and compositional ranges of major, minor and trace elements. Such studies elucidate the co-evolution of the geosphere and biosphere. Accordingly, we investigated trace and minor elements in molybdenite (MoS2) with known ages from 3 billion years to recent. Molybdenite, the commonest mineral of Mo, may prove to be a useful case study as a consequence of its presence in Earth’s early history, the effects of oxidation on Mo mobility, and the possible role of Mo mineral coevolution with biology via its role in the nitrogen fixation enzyme nitrogenase. We employed ICPMS, SEM and electron microprobe analyses to detect trace and minor elements. We detected significant amounts of Mn and Cu (~100 ppm) and greater amounts of Fe, W, and Re (to ~4000 ppm). Molybdenites commonly contain micro inclusions, resulting in local concentrations in otherwise homogeneous samples. Inhomogeneities in Fe, Zn and Sn concentrations, for example, point to the presence of pyrite, sphalerite and cassiterite inclusions, respectively. Analyses examined as a function of time reveal that samples containing significant concentrations (>200 ppm, compared to average values < 100 ppm) of W and Re formed primarily within the last billion years. These trends may reflect changes in the mobility of W and Re in oxic hydrothermal fluids at shallow crustal conditions following the Great Oxidation Event.

Analysis of trace elements in serum from human eating irradiated food

International Nuclear Information System (INIS)

Huang Zongzhi; Zhou Hongdi; Chen Shijie; Gao Sumei

1987-01-01

A method of trace element analysis by Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AEC) in serum from human eating food preserved by irradiation is described. Trace element analysis in human serum is one of the research projects concerning the wholesomeness. 78 serum samples of the human eating food preserved by irradiation were collected. After ashing and solving ICP-AES analysis of serum is performed for detecting 12 trace elements in specimen solution. The detection limitations are in the range of 10 -2 - 10 -3 ppm for differemt elements. The recoveries of elements are over 73%. Concentrations of 12 trace elements in 78 human serum has been calculated with F and t tests at PDP 11/70 computer and it was concluded that there is no significant difference between testing group and control group

Neutron activation analysis of trace elements in biological tissue

Energy Technology Data Exchange (ETDEWEB)

Velandia, J A; Perkons, A K

1974-01-01

Thermal Neutron Activation Analysis with Instrumental Ge(Li) Gamma Spectrometry was used to determine the amounts of more than 30 trace constituents in heart tissue of rats and kidney tissue of rabbits. The results were confirmed by a rapid ion-exchange group separation method in the initial stages of the experiments. The samples were exposed to thermal neutrons for periods between 3 minutes and 14 hours. Significant differences in the amounts and types of trace elements in the two different tissue types are apparent, however, are probably due to specific diets. Tables of relevant nuclear data, standard concentrations, radiochemical separation recoveries, and quantitative analytical results are presented. The ion-exchange group separation scheme and typical examples of the instrumental gamma ray spectra are shown. The techniques developed in this study are being used for a large scale constituent survey of various diseased and healthy human tissues.

Contaminant transport, revegetation, and trace element studies at inactive uranium mill tailings piles

International Nuclear Information System (INIS)

Dreesen, D.R.; Marple, M.L.; Kelley, N.E.

1978-01-01

The stabilization of inactive uranium mill tailings piles is presently under study. These studies have included investigations of stabilizing tailings by attempting to establish native vegetation without applying irrigation. Examination of processes which transport tailings or associated contaminants into the environment has been undertaken to better understand the containment provided by various stabilization methods. The uptake of toxic trace elements and radionuclides by vegetation has been examined as a mechanism of contaminant transport. The source terms of 222 Rn from inactive piles have been determined as well as the attenuation of radon flux provided by shallow soil covers. The possibility of shallow ground water contamination around an inactive pile has been examined to determine the significance of ground water transport as a mode of contaminant migration. The rationale in support of trace element studies related to uranium milling activities is presented including the enrichment, migration, and toxicities of trace elements often associated with uranium deposits. Some concepts for the stabilization of inactive piles are presented to extrapolate from research findings to practical applications. 25 references, 8 tables

Multivariate statistical evaluation of trace elements in groundwater in a coastal area in Shenzhen, China

International Nuclear Information System (INIS)

Chen Kouping; Jiao, Jiu J.; Huang Jianmin; Huang Runqiu

2007-01-01

Multivariate statistical techniques are efficient ways to display complex relationships among many objects. An attempt was made to study the data of trace elements in groundwater using multivariate statistical techniques such as principal component analysis (PCA), Q-mode factor analysis and cluster analysis. The original matrix consisted of 17 trace elements estimated from 55 groundwater samples colleted in 27 wells located in a coastal area in Shenzhen, China. PCA results show that trace elements of V, Cr, As, Mo, W, and U with greatest positive loadings typically occur as soluble oxyanions in oxidizing waters, while Mn and Co with greatest negative loadings are generally more soluble within oxygen depleted groundwater. Cluster analyses demonstrate that most groundwater samples collected from the same well in the study area during summer and winter still fall into the same group. This study also demonstrates the usefulness of multivariate statistical analysis in hydrochemical studies. - Multivariate statistical analysis was used to investigate relationships among trace elements and factors controlling trace element distribution in groundwater

Study of trace elements in milk by nuclear analytical techniques

International Nuclear Information System (INIS)

Gharib, A.; Rahimi, H.; Pyrovan, H.; Raoffi, N.J.; Taherpoor, H.

1985-01-01

This work is part of project with the IAEA in a coordinated program on 'Trace Elements in Human and Bio-environmental Systems' to evaluate their nutritional requierements, interrelations and the role of trace elements in health, metabolism, etc. Cow's milk is regarded to be one of the most important and most nutritious foodstuffs of mankind. Hence, as a first step, an elemental analysis for milk was carried out: a few samples of pasteurized milk and local samples were investigated for essential and toxic trace elements. The secondary aim of the project was the assessment of various analytical techniques involved. AAS, PIXE and NAA are presented here. The latter was applied both instrumentally and radiochemically. Although the results pertaining to the various methods employed are not in good agreement, there is, however, some justification to clarify this internal inconsistency. PIXE analysis is very fast and rather routine, but the technique for trace element analysis needs certain adaptations and improvement. (author)

Study of mobilization and speciation of trace elements in coal pyrolysis

International Nuclear Information System (INIS)

Ting, B.T.G.

1979-01-01

Various types of coal contain high levels of a number of trace elements. Little is known of the fates of these trace elements during the conversion of coal to liquid and gaseous products. Studies were undertaken of mobilization and speciation of trace elements in coal pyrolysis, one of the major coal conversion processes. The bituminous coal was pyrolyzed to produce liquid and gaseous products. The pyrolysis products were collected in traps in an inert gas stream. In addition mildly hydrogenated coal was prepared by mixing with tetralin, a hydrogen donor solvent, at boiling temperature. In order to characterize each element specifically during pyrolysis, base samples of coal and mildly hydrogenated coal (H-coal) were spiked with heavy metal sulfides, trace metals bound to partially oxidized coal (coal humates), and halide salts prior to carrying out pyrolysis. Eight elements were investigated in this research. They are As, Br, Cl, Co, Cr, Mn, Se, and V. Pre-spiked hydrogenated coal, i.e., pulverized coal spiked with halide salts and heavy metal sulfides then hydrogenated with tetralin, was prepared and studied for the fates of these elements during pyrolysis. Chlorinated and brominated coals were also prepared to compare the volatility differences between organically and inorganically bound halogens during the pyrolysis reaction. These products and the coal char residues were analyzed for the spiked elements mainly by neutron activation analysis for the spiked elements to determine their degree of volatility. Volatility and recovery (mass balance) will be discussed for those elements that appeared highly volatile during pyrolysis. In order to understand the halogenated compounds in the pyrolysis products, gas chromatograms were taken to the collected pyrolysis products of coal, hydrogenated coal, NaCl spiked coal, NaBr spiked coal, chlorinated coal, and brominated coal

DNA markers for forensic identification of non-human biological traces

NARCIS (Netherlands)

Wesselink, M.

2018-01-01

In this thesis, DNA markers are described that enable forensically relevant classification of three groups of non-human biological traces: fungi (Chapter 1), domestic cats (Chapters 2, 3 an d 4) and birch trees (Chapters 5 and 6). Because the forensic questions associated with these traces require

Trace elements in nail polish as a source of contamination of nail clippings when used in epidemiological studies

International Nuclear Information System (INIS)

Favaro, P.C.; Bode, P.; De Nadai Fernandes, E.A.

2005-01-01

Trace elements were determined in 27 brands of nail polish using INAA so as to estimate the impact of nail polish remainders when using (finger, toe) nail clippings as a bioindicator for epidemiological studies. Fe was found to be present up to almost 1.7% in one brand. No unambiguous correlation between trace elements and color was established, though transparent polish has the lowest trace element concentrations. An estimate of the maximum effect (no removal of the paint) indicates that over-estimates of some trace element levels in nail with more than 200.000% may occur. If nail clippings will be used to study trace elements, very high demands have to be set to the efficiency and selectivity of the cleaning procedure. (author)

Trace Elements in Cardiovascular Diseases

Energy Technology Data Exchange (ETDEWEB)

Masironi, R. [Cardiovascular Diseases Unit, World Health Organization, Geneva (Switzerland)

1970-07-01

Cardiovascular diseases are the leading cause of death in industrialized countries. Their incidence increases, apparently, as a, function of technological progress so that in the future they may become a major public health problem in developing countries too. Early diagnosis and prevention are the tools best suited to curb such an alarming trend, but our knowledge of these topics is unsatisfactory, Valuable information would be obtained through a systematic investigation of trace elements in relation to cardiovascular function and to various types of cardiovascular diseases. Such studies would provide clues to the following questions: 1. Why does the incidence and type of cardiovascular disease differ from one country to another? May this be related to differences in tissue mineral concentrations among various population groups? 2. Which trace elements if any are beneficial to cardiovascular health, and which are harmful ones that may act as aetiological agents for some cardiovascular diseases? 3. Is it possible to utilize measurements of mineral element concentration for diagnostic purposes in cardiovascular disease? (author)

The Survey of Serum Trace Element Profiles in Down's Syndrome

Directory of Open Access Journals (Sweden)

Leila Farzin

2014-06-01

Full Text Available Background: Immunological, endocrinological, haematological and neurological abnormalities are relatively common in people with Down's syndrome (DS. Zinc (Zn, copper (Cu, selenium (Se and manganese (Mn are elements that act in the maintenance of normal function of these systems. The present study aimed to evaluate the concentration of these elements on DS symptoms. Materials and Methods: This case-control study was done from April to October 2011. Serum trace elements including Zn, Cu, Se and Mn were determined by using atomic absorption spectrometry (AAS in 56 patients with DS and 60 healthy subjects. Results: There was no significant difference in the values of Cu and Se between two groups (p>0.05. While, Zn and Mn levels were found to be significantly decreased in patients with DS compared to the control group (p<0.01 and p<0.001, respectively. Conclusion: Results of this study indicate zinc and manganese deficiency in more than 60% of DS patients. Some of the problems experienced by people with DS may be due to changed level of these trace elements.

Study on trace and rare earth elements in Indonesian oil sands

Energy Technology Data Exchange (ETDEWEB)

Bai, Jing-ru; Wang, Qing; Liu, Hong-peng; Bai, Zhang [Northeast Dianli Univ., Jilin (China). Engineering Research Centre

2013-07-01

Major, trace elements and rare earth and mineral composition of the oil sand samples (ST1, ST2, ST3) and the oil sand retorting residue (semi-coke: SC1, SC2, SC3) from Indonesian were determined by XFS, ICP-MS and XRD methods. The trace elements content in oil sand is pretty much the same thing in Earth's Clarke value. The trace element is abundantly in earth's Clarke, in oil sand yet, for Ti, Mn, Ba, Sr, but these elements are lower enrichment. However, the Cr (EF = 16.8) and Mo (EF = 11.8) are ''enrichment'' in ST1; the Ni (EF =10.5), Se (EF = 17.5), Sr (EF = 28.7), Mo (EF = 106.5), Sc (EF = 12.8) and U (EF = 43.2) are ''enrichment'' in ST2; the Se (EF = 12.6), Sr (EF = 18.4), Mo (EF = 47.5), and U (EF = 27.8) are ''enrichment'' in ST3. Calculations show that trace elements in sime-coke have lower evaporation rate during Fischer Assay. Trace elements in raw oil sand are so stable that trace elements can't move easily to other pyrolysis product but enrich to sime-coke. After retorting, more elements are EF > 10, such as B, V, Ni, As, Se, Sr, Mo, Hg, Cs and U. It is essential to take the pollution produced by trace elements in sime-coke during the sime-coke utilization into consideration. The REEs content had a high correlation with the ash in oil sand. The REE is closely related to terrigenous elastic rocks.

Traces generating what was there

CERN Document Server

2017-01-01

Traces keep time contained and make visible what was there. Going back to the art of trace-reading, they continue to be a fundamental resource for scientific knowledge production. The contributions study, from the biology laboratory to the large colliders of particle physics, techniques involved in the production of material traces. Following their changes over two centuries, this collection shows the continuities they have in the digital age.

Potential role of peroxisome proliferator activated receptor gamma activation on serum visfatin and trace elements in high fat diet induced type 2 diabetes mellitus.

Science.gov (United States)

Tabassum, Arshia; Zaidi, Syeda Nuzhat Fatima; Yasmeen, Kausar; Mahboob, Tabassum

2018-07-15

Electrolytes and trace elements dysregulation play an important role in the progression of obesity and diabetes complications. The present study was designed to evaluate the insulin sensitizing effects of peroxisomes proliferators activated receptor gamma (PPAR-γ) agonist on trace elements in obesity induced type 2 diabetes mellitus and correlate with serum visfatin. Wistar rats were categorized into five groups. Group I served as control; Group II fed on high fat diet (HFD); Group III fed on HFD and treated with rosiglitazone (3 mg/kg) for 7 days; Group IV were T2DM rats induce by HFD and low dose of streptozotocin (i.p. 35 mg/kg); Group V was T2DM rats treated with rosiglitazone (3 mg/kg) for 7 days. Serum and tissues electrolytes levels and renal, hepatic and cardiac tissues trace elements were estimated by flame photometer and atomic absorption spectroscopy. Serum visfatin was estimated by ELISA. Pearson correlations were analyzed among fasting blood glucose (FBG), serum visfatin and tissues trace elements. Results of the current study showed hyponatremia, hyperkalemia, hypomagnesemia and hypercalcemia in HFD and T2DM groups. HFD and T2DM also showed elevated copper and iron levels; however, zinc and selenium levels were decreased. Rosiglitazone treatment increased the insulin sensitization and altered these changes. A Strong association was observed among FBG, serum visfatin and trace elements levels of HFD and T2DM. Obesity and diabetes mellitus disturbed visfatin, electrolytes and trace elements homeostasis. Rosiglitazone treatment restored these changes. The results of the study could serve as a basis for further studies for the prevention of diabetic complications. Copyright © 2018 Elsevier Inc. All rights reserved.

Effect of the angiotensin-converting enzyme inhibitor trandolapril on mortality and morbidity in diabetic patients with left ventricular dysfunction after acute myocardial infarction. Trace Study Group

DEFF Research Database (Denmark)

Gustafsson, I; Torp-Pedersen, C; Køber, L

1999-01-01

OBJECTIVES: This study evaluated the efficacy of long-term treatment with the angiotensin-converting enzyme (ACE) inhibitor trandolapril in diabetic patients with left ventricular dysfunction after acute myocardial infarction (AMI). BACKGROUND: Patients with diabetes mellitus have a high mortality...... the Trandolapril Cardiac Evaluation (TRACE) study, which was a randomized, double-blind, placebo-controlled trial of trandolapril in 1,749 patients with AMI and ejection fraction history of diabetes was found in 237 (14%) of the 1,749 patients. Treatment...

The role of trace minerals in osteoporosis. Report of an IAEA consultants' meeting

International Nuclear Information System (INIS)

1996-01-01

A Consultants' Meeting convened by the IAEA in December 1995 made recommendations on trace mineral studies to be conducted within the framework of an on-going Co-ordinated Research Programme (CRP) on Comparative International Studies of Osteoporosis Using Isotope Techniques. Three kinds of studies were recommended: (1) autopsy studies of bone composition (involving the collection of iliac crest samples from healthy accident victims), (2) biopsy studies (involving the collection of iliac crest biopsies from subjects whose bone density has been measured by DEXA in the 'core' component of the Agency's CRP), and (3) dietary intervention studies (involving the measurement of bone density in subjects who have received supplemental minerals and trace elements, and in a control group). Bone samples (collected at autopsy or by biopsy) are to be analyzed for several elements, including the major and minor elements: Ca, K, Mg, S, and (2) the trace elements: Cu, F, Mn and Zn. The recommended analytical techniques include neutron activation analysis (NAA) and ICP-MS. In the dietary intervention studies it is proposed that the supplements should be designed individually for each study group to increase the intake of selected minerals, trace elements and vitamins (mainly Ca, K, Mg, P, Cu, F, Mn, and Zn, and vitamins A, C, D, and K) up to the same standard recommended dietary allowances for all subjects. These recommendations are mainly addressed at participants in the Agency's CRP. However, in view of the growing interest in this topic on the part of many other scientists who are concerned with issues relating to bone health, this report has been prepared in order to assist in making these matters better known to a wider audience

Effect of kombucha on some trace element levels in different organs of electromagnetic field exposed rats

Directory of Open Access Journals (Sweden)

Ola A. Gharib

2014-01-01

Full Text Available Mobile phones have increased exponentially all over the world. The present study was performed to evaluate the effect of kombucha (KT on some trace element levels of brain, spleen and intestine in male albino rats exposed to a 950 MHz electromagnetic field (EMF. Four experimental groups labelled as controls, EMF group, KT group and KT + EMF group were formed with six randomly chosen animals in each group. After EMF exposure for eight weeks and the animals were sacrificed by decapitation. Brain, spleen and intestine samples were collected for trace element analysis. The group of animals subjected to electromagnetic waves caused significant increases in iron copper levels and copper/zinc ratio accompanied with a decrease of zinc level in all studied organs. Combined treatment of kombucha with EMF resulted in a successful attenuation of these adverse effects of EMF. From present findings we can state that kombucha as a supplement has an ameliorative signs against the effects of electromagnetic radiation.

15N-urea tracing emission spectroscopy for detecting the infection of Helicobacter pylori

International Nuclear Information System (INIS)

Zhu Yayi

2002-01-01

Objective: To study a noninvasive and nonradioactive method, 15 N-urea tracing emission spectroscopy, for detecting the Helicobacter pylori (Hp) infection. Methods: A group of 26 patients was tested with a method of 15 N-urea tracing emission spectroscopy for detecting the Hp infection. Results: Taking the bacterial culture or (and) Gram stain as a standard, the specificity, sensitivity and positive predicting rate of the test were 81%, 89% and 84%, respectively. Conclusion: The method could be considered useful for clinical practice

Comparative study of boron transport models in NRC Thermal-Hydraulic Code Trace

Energy Technology Data Exchange (ETDEWEB)

Olmo-Juan, Nicolás; Barrachina, Teresa; Miró, Rafael; Verdú, Gumersindo; Pereira, Claubia, E-mail: nioljua@iqn.upv.es, E-mail: tbarrachina@iqn.upv.es, E-mail: rmiro@iqn.upv.es, E-mail: gverdu@iqn.upv.es, E-mail: claubia@nuclear.ufmg.br [Institute for Industrial, Radiophysical and Environmental Safety (ISIRYM). Universitat Politècnica de València (Spain); Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear

2017-07-01

Recently, the interest in the study of various types of transients involving changes in the boron concentration inside the reactor, has led to an increase in the interest of developing and studying new models and tools that allow a correct study of boron transport. Therefore, a significant variety of different boron transport models and spatial difference schemes are available in the thermal-hydraulic codes, as TRACE. According to this interest, in this work it will be compared the results obtained using the different boron transport models implemented in the NRC thermal-hydraulic code TRACE. To do this, a set of models have been created using the different options and configurations that could have influence in boron transport. These models allow to reproduce a simple event of filling or emptying the boron concentration in a long pipe. Moreover, with the aim to compare the differences obtained when one-dimensional or three-dimensional components are chosen, it has modeled many different cases using only pipe components or a mix of pipe and vessel components. In addition, the influence of the void fraction in the boron transport has been studied and compared under close conditions to BWR commercial model. A final collection of the different cases and boron transport models are compared between them and those corresponding to the analytical solution provided by the Burgers equation. From this comparison, important conclusions are drawn that will be the basis of modeling the boron transport in TRACE adequately. (author)

APW path traced for the Guiana Shield (2070-1960 Ma) and Paleogeographic Implications: Paleomagnetic data from the 1.98-1.96 Ga Surumu Group (Northern Amazonian Craton)

Science.gov (United States)

Bispo-Santos, F.; Dagrella Filho, M. S.; Reis, N. J.; Trindade, R. I.

2013-05-01

Definition of continental paleogeography for times prior to formation of Columbia Supercontinent (1900-1850 Ma) is very complex, since amalgamation of some continental blocks of Earth was still in progress, as in the case of Laurentia, Baltica and Amazonian Craton. So, paleogeographic models proposed for this time are still very speculative and/or subjective. The use of the paleomagnetic technique tracing apparent polar wander (APW) paths for the various cratonic blocks can contribute to understand the continental amalgamation and breakup, especially for times where all created oceanic lithosphere was fully consumed. In this study, we present the paleomagnetic data obtained for samples collected from 39 sites from the well-dated 1980-1960 Ma (U-Pb) volcanic rocks belonging to the Surumu Group, cropping out in the northern Roraima State (Guiana Shield, Amazonian Craton). AF and thermal treatment revealed northwestern directions with moderate downward inclinations on samples from 20 out of the 39 analyzed sites. Site mean directions cluster around the mean, Dm = 298.6°; Im = 39.4° (N = 20; α95 = 10.1°), which yielded a key paleomagnetic pole (SG) for the Guiana Shield, located at 234.8°E, 27.4°N (A95 = 9.8°). Magnetic mineralogy experiments show that the magnetization of these rocks, probably of primary origin, is carried by magnetite and/or hematite. The SG pole contributes to a better fit of the APW path traced for Guiana Shield during the Paleoproterozoic (2070-1960 Ma). Comparison with the APW path traced for the West-Africa Craton for the same time interval suggests that these cratonic blocks were linked at 2000-1960 Ma ago, forming a paleogeography in which the Guri (Guiana Shield) and Sassandra (West-Africa Craton) shear zones were aligned as suggested in previous geologic models. KEYWORDS: Paleoproterozoic, Paleomagnetism, APWP, Amazonian Craton, Surumu Group.

Study of trace elements in milk by nuclear analytical techniques

Energy Technology Data Exchange (ETDEWEB)

Gharib, A.; Rahimi, H.; Peyrovan, H.; Raofei, H.N.J.; Taherpour, H. (Atomic Energy Organization of Iran, Teheran. Nuclear Research Centre)

This work is part of a project with the IAEA, in a coordinated programme on ''trace elements in Human Nutrition and Bio-Environmental Systems'' to evaluate their nutritional requirements, interrelations and the role of trace elements in health, metabolism etc. Cow's milk is regarded as one of the most important and nutritious foodstuffs consumed by people. Hence, as a first step, an elemental analysis for milk was carried out for this purpose so a few samples of pasteurized milk and local samples were investigated for essential and toxic trace elements. The secondary aim of this project was the assessment of various analytical techniques involved. However, in the present work, the methods involved were AAS, PIXE and NAA. The latter method applied, both instrumentally and radiochemically. Although the results pertaining to the various methods employed are not in good agreement, there is however, some justification to clarify this internal inconsistency. The precision for NAA and AAS allows greater degree of acceptance respectively. Although PIXE is very fast and rather routine, the technique of trace element analysis needs certain adaptations and developments.

Sarcoptic mange in dogs: Its effect on liver, oxidative stress, trace minerals and vitamins.

Science.gov (United States)

Beigh, S A; Soodan, J S; Bhat, A M

2016-08-30

The present study was aimed to determine the effect on liver, associated oxidative stress, trace element and vitamin alteration in dogs with sarcoptic mange. A total of 24 dogs with clinically established diagnosis of sarcoptic mange, divided into two groups, severely infested group (n=9) and mild/moderately infested group (n=15), according to the extent of skin lesions caused by sarcoptic mange and 6 dogs as control group were included in the present study. In comparison to healthy control hemoglobin, PCV, and TEC were significantly (Pdogs with sarcoptic mange however, significant increase in TLC along with neutrophilia and lymphopenia was observed only in severely infested dogs. The albumin, glucose and cholesterol were significantly (Pdogs when compared to other two groups. Malondialdehyde (MDA) levels were significantly (Pdogs with sarcoptic mange, with levels highest in severely infested groups. Activity of superoxide dismutase (SOD) (Psarcoptic infested dogs when compared with the healthy control group. Zinc and copper levels in dogs with sarcoptic mange were significantly (Psarcoptic infested dogs when compared to healthy control. From the present study, it was concluded that sarcoptic mange in dogs affects the liver and the infestation is associated with oxidant/anti-oxidant imbalance, significant alteration in trace elements and vitamins. Copyright © 2016 Elsevier B.V. All rights reserved.

TraceContract

Science.gov (United States)

Kavelund, Klaus; Barringer, Howard

2012-01-01

TraceContract is an API (Application Programming Interface) for trace analysis. A trace is a sequence of events, and can, for example, be generated by a running program, instrumented appropriately to generate events. An event can be any data object. An example of a trace is a log file containing events that a programmer has found important to record during a program execution. Trace - Contract takes as input such a trace together with a specification formulated using the API and reports on any violations of the specification, potentially calling code (reactions) to be executed when violations are detected. The software is developed as an internal DSL (Domain Specific Language) in the Scala programming language. Scala is a relatively new programming language that is specifically convenient for defining such internal DSLs due to a number of language characteristics. This includes Scala s elegant combination of object-oriented and functional programming, a succinct notation, and an advanced type system. The DSL offers a combination of data-parameterized state machines and temporal logic, which is novel. As an extension of Scala, it is a very expressive and convenient log file analysis framework.

The mysterious trace amines: protean neuromodulators of synaptic transmission in mammalian brain.

Science.gov (United States)

Burchett, Scott A; Hicks, T Philip

2006-08-01

The trace amines are a structurally related group of amines and their isomers synthesized in mammalian brain and peripheral nervous tissues. They are closely associated metabolically with the dopamine, noradrenaline and serotonin neurotransmitter systems in mammalian brain. Like dopamine, noradrenaline and serotonin the trace amines have been implicated in a vast array of human disorders of affect and cognition. The trace amines are unique as they are present in trace concentrations, exhibit high rates of metabolism and are distributed heterogeneously in mammalian brain. While some are synthesized in their parent amine neurotransmitter systems, there is also evidence to suggest other trace amines may comprise their own independent neurotransmitter systems. A substantial body of evidence suggests that the trace amines may play very significant roles in the coordination of biogenic amine-based synaptic physiology. At high concentrations, they have well-characterized presynaptic "amphetamine-like" effects on catecholamine and indolamine release, reuptake and biosynthesis; at lower concentrations, they possess postsynaptic modulatory effects that potentiate the activity of other neurotransmitters, particularly dopamine and serotonin. The trace amines also possess electrophysiological effects that are in opposition to these neurotransmitters, indicating to some researchers the existence of receptors specific for the trace amines. While binding sites or receptors for a few of the trace amines have been advanced, the absence of cloned receptor protein has impeded significant development of their detailed mechanistic roles in the coordination of catecholamine and indolamine synaptic physiology. The recent discovery and characterization of a family of mammalian G protein-coupled receptors responsive to trace amines such as beta-phenylethylamine, tyramine, and octopamine, including socially ingested psychotropic drugs such as amphetamine, 3,4-methylenedioxymethamphetamine, N

Geologic and geochemical studies of the New Albany Shale Group (Devonian-Mississippian) in Illinois. Final report

Energy Technology Data Exchange (ETDEWEB)

Bergstrom, R.E.; Shimp, N.F.

1980-06-30

The Illinois State Geological Survey is conducting geological and geochemical investigations to evaluate the potential of New Albany Group shales as a source of hydrocarbons, particularly natural gas. Geological studies include stratigraphy and structure, mineralogic and petrographic characterization; analyses of physical properties; and development of a computer-based resources evaluation system. Geochemical studies include organic carbon content and trace elements; hydrocarbon content and composition; and adsorption/desorption studies of gas through shales. Separate abstracts have been prepared for each task reported.

Evaluating cleansing effects on trace elements and stable isotope values in feathers of oiled birds.

Science.gov (United States)

Valladares, Sonia; Moreno, Roćio; Jover, Lluis; Sanpera, Carola

2010-01-01

Feathers of seabirds are widely used as a nondestructive tissue for pollution monitoring of trace elements, as well as convenient samples for trophic ecology studies by means of stable isotope analysis (SIA). Nevertheless, feathers can be occasionally impregnated with oil from deliberate ship discharges and from massive oil spill accidents. The feather structure makes them effective traps for particles and are subject to external contamination. It is unknown to what extent the oil adhered to feathers can change trace element concentrations or stable isotope signatures. This study has two primary objectives: (1) to assess if there are differences between trace element concentrations and stable isotope signatures of oiled and clean feathers, and (2) to determine if the cleansing of oiled feathers using commonly applied techniques such as sodium hydroxide (NaOH) washes in combination with an organic solvent (hexane) is more effective than using NaOH alone. In order to do this, we analysed trace elements (Se, Hg, Pb, Cu and Zn) and stable isotopes (delta(13)C and delta(15)N) of individual feathers of yellow-legged gulls (Larus michahellis) which were affected by the 2002 Prestige oil spill in Galicia (NW Spain). Two sets of feathers were analysed, one group were oil-free (Control group) and the other had oil adhered to its surface (Oiled group). We expected to find differences between control and oiled feathers when cleaning exclusively with NaOH and no differences when using hexane. Our results did not show significant differences between Control and Oiled groups as a consequence of the cleansing method used. Unexpectedly, the additional cleansing with hexane resulted in decreasing selenium concentrations and increasing zinc and delta(15)N values in all groups of feathers.

Potential benefit of trace element supplementation of sheep on a low ...

African Journals Online (AJOL)

A study was conducted to test whether supplementation of trace elements would have any beneficial effect on year-old ewes receiving a submaintenance level of nutrition. The ewes were fed a poor quality hay. The control group received no supplementation (Treatment 1). A solution containing copper (Cu, 5 mg/d), ...

Archaeological significance of trace element analysis of South West African potsherds

International Nuclear Information System (INIS)

Boule, G.J.; Peisach, M.; Jacobson, L.

1979-01-01

The archaeological study of early population movements in South West Africa/Namibia has been aided by trace element analysis of potsherds. The results suggest that the central areas of the country were populated by mobile groups of pastoralists and hunter-gatherers, while the northern areas were settled by sedentary peoples [af

Study on the correlation between the trace elements with cerebrovascular diseases

Energy Technology Data Exchange (ETDEWEB)

Dazhong, Zhang; Mingsong, Tai; Suqing, Chen [Sichuan Univ., Chengdu, SC (China). Inst. of Nuclear Science and Technology; and others

1990-11-01

In the paper, the correlation between the cerebroscular diseases, as haemorrhage, cerebral atherosclerosis, cerebral embolism, with trace element contents in hair and tissues of controls and diseases has been studied by PIXE. Biochemistry test for diseased cerebral atheroselerosis patientes were done. The distinction between the controls and diseases were revealed.

A review of Human Biomonitoring studies of trace elements in Pakistan.

Science.gov (United States)

Waseem, Amir; Arshad, Jahanzaib

2016-11-01

Human biomonitoring (HBM) measures the concentration levels of substances or their metabolites in human body fluids and tissues. HBM of dose and biochemical effect monitoring is an effective way of measuring human exposure to chemical substances. Many countries have conducted HBM studies to develop a data base for many chemicals including trace metals of health concern for their risk assessment and risk management. However, in Pakistan, HBM program on large scale for general population does not exist at present or in the past has been reported. Various individual HBM studies have been reported on the assessment of trace elements (usually heavy metals) from Pakistan; most of them are epidemiological cross sectional surveys. In this current review we tried to develop a data base of HBM studies of trace elements namely arsenic, cadmium, copper, chromium, iron, lead, manganese, nickel, and zinc in biological fluids (blood, urine) and tissues (hair, nails) in general population of Pakistan. Studies from all available sources have been explored, discussed and presented in the form of tables and figures. The results of these studies were critically compared with large scale HBM programs of other countries, (US & European communities etc). It was observed from the present study that the most of the toxic metals in biological fluids/tissues in general population of Pakistan, have higher background values comparatively. For example the mean values of toxic metals like As, Cd, Cr, Ni, and Pb in blood of general population were found as 2.08 μg/L, 4.24 μg/L, 60.5 μg/L, 1.95 μg/L, 198 μg/L respectively. Similarly, the urine mean values of 67.6 μg/L, 3.2 μg/L, 16.4 μg/L, 6.2 μg/L and 86.5 μg/L were observed for As, Cd, Cr, Ni, and Pb respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

Trace elements and naturally occurring radioactive materials in 'Non-traditional fertilizers' used in Ghana

International Nuclear Information System (INIS)

Assibey, E. O.

2013-07-01

Fertilizers have been implicated for being contaminated with toxic trace elements and naturally occurring radioactive materials (NORMs) even though they are an indispensable component of our agriculture. This phenomenon of contamination has been investigated and established world-wide in various forms of fertilizers (i.e., granular or 'traditional' type and liquid/powder or 'non-traditional type'). In Ghana, the crop sub-sector has seen a gradual rise in the importation and use of 'non-traditional fertilizers' which are applied to both the foliar parts and roots of plants. This notwithstanding, research on fertilizers has been largely skewed towards the 'traditional' types, focusing principally on the subjects of yield, effects of application and their quality. This study was, therefore, undertaken to bridge the knowledge gap by investigating the levels of trace elements and NORMs found in the 'non-traditional' fertilizers used in Ghana. The principal objective of the study was to investigate the suitability of the 'non-traditional fertilizers' for agricultural purposes with respect to trace elements and NORMs contamination. Atomic Absorption Spectrometry and instrumental Neutron Activation Analysis were employed to determine the trace elements (Cu, Zn, Fe, Na, Al, Br, Ni, Cd, As, Hg, Co, Pb, La, Mn, Si, Ca, Cl, S, K, Ba and V) and NORMs ( 238 U, 232 Th and 40 K) concentrations in thirty-nine (39) fertilizer samples taken from two major agro-input hubs in the country (Kumasi-Kejetia and Accra). Multivariate statistical analyses (cluster analysis, principal component analysis and pearson's correlation) were applied to the data obtained in order to identify possible sources of contamination, investigate sample/ parameter affinities and groupings and for fingerprinting. The toxic trace element concentrations determined in all samples were found to be in the order Fe>Cu>Co>Cd>Cr >Ni>Pb>As>Hg. The study found most of the trace elements determined to be within limits set

Study of osteoporosis through the measurement of bone mineral density and trace elements

International Nuclear Information System (INIS)

Aras, N.K.; Yilmaz, G.; Alkan, S.; Korkusuz, F.; Ungan, M.; Kuscu, L.; Laleli, Y.; Eksioglu, F.; Sepici, B.

2002-01-01

The main purpose of this study was to establish a relation, if any, between bone mineral density (BMD) of the healthy Turkish population of the ages between 15 and 50 with social and demographic information, family history of fractures, personal and inherited characteristic, smoking and alcohol habit, history of fertility, level of physical activity, food consumption especially trace elements and other variables. Most of these relations were discussed in the last two Research Coordinated Meetings, in San Diego, CA, October 1996 and Sao Paulo, Brazil, August 1998. Since then we have concentrated our work on more BMD and trace element measurements in bone

β-trace protein as a diagnostic marker for perilymphatic fluid fistula: a prospective controlled pilot study to test a sample collection technique.

Science.gov (United States)

Bachmann-Harildstad, Gregor; Stenklev, Niels Christian; Myrvoll, Elin; Jablonski, Greg; Klingenberg, Olav

2011-01-01

The diagnosis of perilymphatic fluid (PLF) fistula is still challenging. Perilymphatic fluid fistula is one possible complication after stapedotomy or cochlear implant surgery. We have performed a prospective diagnostic pilot study to further investigate β-trace protein (β-TP) as a marker for PLF fistula. In this pilot study, we tested the sensitivity of the β-TP marker using a simple method for sample collection from the tympanic cavity. Prospective controlled diagnostic study. Two-center tertiary referral hospitals. A total of 35 adult patients undergoing ear surgery were included. Subjects were divided into 2 groups: 1) 19 patients undergoing stapedotomy were investigated for PLF fistula in samples obtained from the tympanic cavity and 2) 16 patients undergoing myringoplasty were investigated for PLF fistula in samples from the tympanic cavity. This group served as the control. Mean age +/- SD at surgery was 49.9 +/- 8.0 years in the study group and 39.69 +/- 15.47 years in the control group. β-Trace protein (prostaglandin D synthase) in tympanic cavity samples and serum samples was analyzed. The samples were collected by gradually filling the tympanic cavity with 100 to 200 μl sodium chloride and by immediately collecting a volume of 60 to 100 μl in a mucus specimen set container. The concentration of β-TP was quantified using laser nephelometry. The median β-TP in the study group was 0.8 mg/L (range, 0.05-4.5 mg/L). In the control group, the median β-TP value was 0.16 mg/L (range, 0.01-0.36 mg/L). Thirty-five percent of the values in the study group were below the highest value in the negative control group. The β-TP values of the tympanic cavity samples were significantly higher in the study group than in controls (p = 0.0001). The serum values were 0.55 +/- 0.18 and 0.53 +/- 0.11 mg/L, respectively. It may be feasible to test for PLF fistula using β-TP in samples from the tympanic cavity. Our results, however, suggest a relative low diagnostic

Neurotoxic lesions of the dorsal and ventral hippocampus impair acquisition and expression of trace-conditioned fear-potentiated startle in rats.

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Trivedi, Mehul A; Coover, Gary D

2006-04-03

Pavlovian delay conditioning, in which a conditioned stimulus (CS) and unconditioned stimulus (US) co-terminate, is thought to reflect non-declarative memory. In contrast, trace conditioning, in which the CS and US are temporally separate, is thought to reflect declarative memory. Hippocampal lesions impair acquisition and expression of trace conditioning measured by the conditioned freezing and eyeblink responses, while having little effect on the acquisition of delay conditioning. Recent evidence suggests that lesions of the ventral hippocampus (VH) impair conditioned fear under conditions in which dorsal hippocampal (DH) lesions have little effect. In the present study, we examined the time-course of fear expression after delay and trace conditioning using the fear-potentiated startle (FPS) reflex, and the effects of pre- and post-training lesions to the VH and DH on trace-conditioned FPS. We found that both delay- and trace-conditioned rats displayed significant FPS near the end of the CS relative to the unpaired control group. In contrast, trace-conditioned rats displayed significant FPS throughout the duration of the trace interval, whereas FPS decayed rapidly to baseline after CS offset in delay-conditioned rats. In experiment 2, both DH and VH lesions were found to significantly reduce the overall magnitude of FPS compared to the control group, however, no differences were found between the DH and VH groups. These findings support a role for both the DH and VH in trace fear conditioning, and suggest that the greater effect of VH lesions on conditioned fear might be specific to certain measures of fear.

Trace Metal Requirements and Interactions in Symbiodinium kawagutii

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Irene B. Rodriguez

2018-02-01

Full Text Available Photosynthetic organisms need trace metals for various biological processes and different groups of microalgae have distinctive obligate necessities due to their respective biochemical requirements and ecological niches. We have previously shown that the dinoflagellate Symbiodinium kawagutii requires high concentrations of bioavailable Fe to achieve optimum growth. Here, we further explored the trace metal requirements of S. kawagutii with intensive focus on the effect of individual metal and its interaction with other divalent metals. We found that low Zn availability significantly decreases growth rates and results in elevated intracellular Mn, Co, Ni, and Fe quotas in the dinoflagellate. The results highlight the complex interaction among trace metals in S. kawagutii and suggest either metal replacement strategy to counter low Zn availability or enhanced uptake of other metals by non-specific divalent metal transporters. In this work, we also examined the Fe requirement of S. kawagutii using continuous cultures. We validated that 500 pM of Fe′ was sufficient to support maximum cell density during steady state growth period either at 26 or 28°C. This study shows that growth of S. kawagutii was limited by metal availability in the following order, Fe > Zn > Mn > Cu > Ni > Co. The fundamental information obtained for the free-living Symbiodinium shall provide insights into how trace metal availability, either from ambient seawater or hosts, affects growth and proliferation of symbiotic dinoflagellates and the interaction between symbiont and their hosts.

Linking Environmental Magnetism to Geochemical Studies and Management of Trace Metals. Examples from Fluvial, Estuarine and Marine Systems

Directory of Open Access Journals (Sweden)

Michael Scoullos

2014-07-01

Full Text Available Among the diverse research fields and wide range of studies encompassed by environmental magnetism, the present work elaborates on critical aspects of the geochemistry of trace metals that emerged through years of original research in a variety of environmental compartments. This review aims at sharing the insights gained on (a tracing metal pollution sources; and (b identifying processes and transport pathways from sources to depositional environments. Case studies on the Elefsis Gulf (Greece and the Gulf of Lions (France demonstrate the potential of combined magnetic measurements and chemical analysis to trace pollution signals resulting from land-based sources and atmospheric deposition. Case studies on estuarine environments, namely the Louros, Acheloos, and Asopos Estuaries (Greece, address modes of trace metal behavior under the influence of different hydrological regimes and elucidate in situ processes within the transitional estuarine zone, that define their ultimate fate. As sources, transport pathways, and processes of trace metals are fundamental in environmental management assessments, the involvement of magnetic measurements in the policy cycle could facilitate the development and implementation of appropriate regulatory measures for the integrated management of river basins, coastal, and marine areas.

La formule des traces tordue d’après le Friday Morning Seminar

CERN Document Server

Labesse, Jean-Pierre

2013-01-01

La formule des traces pour un groupe réductif connexe arbitraire est due à James Arthur. Le cas tordu a fait l'objet du Friday Morning Seminar à l'Institute for Advanced Study de Princeton pendant l'année académique 1983-1984. Lors de ce séminaire, des exposés ont été présentés par Laurent Clozel, Jean-Pierre Labesse et Robert Langlands. Les notes de ces exposés, rédigées dans l'urgence, avaient besoin d'être revues et complétées. L'ambition des auteurs du présent ouvrage est de donner, en s'appuyant sur ces notes, une preuve complète pour la formule des traces tordue, dans sa version primitive i.e. sa forme non invariante. Ceci est la première étape du projet de l'équipe parisienne animée par Laurent Clozel et Jean-Loup Waldspurger, dont le but est de donner une preuve complète de la stabilisation de la formule des traces tordue, qui est l'outil fondamental utilisé par J. Arthur dans son livre à paraître sur l'endoscopie tordue pour le groupe linéaire avec application aux groupes ...

The study of trace elements in milk by nuclear analytical techniques

International Nuclear Information System (INIS)

Gharib, A.; Rahimi, H.; Peyrovan, H.; Raofei, H.N.J.; Taherpour, H.

1983-01-01

This work is part of a project with the IAEA, in a coordinated programme on ''Trace Elements in Human Nutrition and Bio-Environmental Systems'' to evaluate their nutritional requirements, interrelations and the role of Trace Elements in health, metabolism etc. Cow's milk being regarded as one of the most important and nutritious foodstuffs consumed by people. Hence as a first step, an elemental analysis for milk was carried out for this purpose so a few samples of pasteurized milk and local samples were investigated for essential and toxic trace elements. The secondary aim of this project was the assessment of various analytical techniques involved. However, in the present work, the methods involved were AAS, PIXE and NAA. The latter method applied, both instrumentally and radiochemically. Although the results pertaining to the various methods employed are not in good agreement, there is however, some justification to clarify this internal inconsistency. The precision for NAA and AAS allows greater degree of acceptance respectively. Although PIXE is a very fast and rather a routine but the technique of trace element analysis needs certain adaptations and developments

Influence of S186 on trace elements in organs of dogs

International Nuclear Information System (INIS)

Luo Meichu; Li Landi; Chen Guibao; Zhang Meizhen

1993-01-01

The authors report the influence of a radiostrontium de-cooperating agents, S186 (calcium sodium N-acetylproplysmine 1, 1-diphosphonate), on trace elements in internal organs of dogs. The trace elements contents were determined with a PE-3030 atomic absorption spectrophotometer. Compared with the control group, the trace elements (Cu, Zn and Mn) contents and the Cu/Zn ratio in organs of Beagle dogs after intramuscular injection of S186 for 30 days did not change obviously except the Cu content in the liver increased

Application of neutron activation analysis to biological materials. Pt. 4. Approach to simultaneous determination of trace elements in human eye tissues with non-destructive neutron activation analysis

Energy Technology Data Exchange (ETDEWEB)

Yamaguchi, T; Bando, M; Nakajima, A [Juntendo Univ., Tokyo (Japan). School of Medicine; Terai, M [Tokyo Metropolitan Univ. (Japan). Faculty of Science; Suzuki-Yasumoto, M [National Inst. of Radiological Sciences, Chiba (Japan)

1980-01-01

Fourteen trace elements (short-lived nuclides: Al, Br, Cu, Mn and V; long-lived nuclides: Ag, Au, Cd, Co, Cr, Fe, Sc, Se and Zn) in human eye tissues are determined simultaneously by non-destructive neutron activation analysis. The quantity of Al, Br, Fe, Se and Zn in the eye tissues (about 1 to more than 10 ..mu..g/g dry weight tissue) seems to be higher than that of other trace elements, although the content of each trace element in individual tissue is scattered in a wide range. Conjunctiva, iris (+ciliary body) and choroid (+pigment epithelium) seem to contain larger amount of various trace elements than other eye tissues. From correlation studies it is evident that the relative distribution of 14 trace elements in various eye tissues are similar, and furthermore the content of trace elements in the eye tissues may be correlated in each of the three groups (group A: Cd, Se and Zn; group B: Al, Cr, Fe, Se and V; group C: Al, Au, Fe and Se).

An analysis of fracture trace patterns in areas of flat-lying sedimentary rocks for the detection of buried geologic structure. [Kansas and Texas

Science.gov (United States)

Podwysocki, M. H.

1974-01-01

Two study areas in a cratonic platform underlain by flat-lying sedimentary rocks were analyzed to determine if a quantitative relationship exists between fracture trace patterns and their frequency distributions and subsurface structural closures which might contain petroleum. Fracture trace lengths and frequency (number of fracture traces per unit area) were analyzed by trend surface analysis and length frequency distributions also were compared to a standard Gaussian distribution. Composite rose diagrams of fracture traces were analyzed using a multivariate analysis method which grouped or clustered the rose diagrams and their respective areas on the basis of the behavior of the rays of the rose diagram. Analysis indicates that the lengths of fracture traces are log-normally distributed according to the mapping technique used. Fracture trace frequency appeared higher on the flanks of active structures and lower around passive reef structures. Fracture trace log-mean lengths were shorter over several types of structures, perhaps due to increased fracturing and subsequent erosion. Analysis of rose diagrams using a multivariate technique indicated lithology as the primary control for the lower grouping levels. Groupings at higher levels indicated that areas overlying active structures may be isolated from their neighbors by this technique while passive structures showed no differences which could be isolated.

Use of World Wide Web-based directories for tracing subjects in epidemiologic studies.

Science.gov (United States)

Koo, M M; Rohan, T E

2000-11-01

The recent availability of World Wide Web-based directories has opened up a new approach for tracing subjects in epidemiologic studies. The completeness of two World Wide Web-based directories (Canada411 and InfoSpace Canada) for subject tracing was evaluated by using a randomized crossover design for 346 adults randomly selected from respondents in an ongoing cohort study. About half (56.4%) of the subjects were successfully located by using either Canada411 or InfoSpace. Of the 43.6% of the subjects who could not be located using either directory, the majority (73.5%) were female. Overall, there was no clear advantage of one directory over the other. Although Canada411 could find significantly more subjects than InfoSpace, the number of potential matches returned by Canada411 was also higher, which meant that a longer list of potential matches had to be examined before a true match could be found. One strategy to minimize the number of potential matches per true match is to first search by InfoSpace with the last name and first name, then by Canada411 with the last name and first name, and finally by InfoSpace with the last name and first initial. Internet-based searches represent a potentially useful approach to tracing subjects in epidemiologic studies.

The influence of a slow-release multi-trace element ruminal bolus on trace element status, number of ovarian follicles and pregnancy outcomes in synchronized Afshari ewes

Science.gov (United States)

Abdollahi, E.; Kohram, H.; Shahir, M. H.; Nemati, M. H.

2015-01-01

Published data on the effects of ruminal bolus on the number of ovulatory follicles in ewes does not exist. The present study determined the effects of a ruminal bolus on trace element status, follicular dynamics and reproductive performance in ewes. Eighty Afshari cycling ewes were synchronized during breeding season using CIDR for 14 days and assigned to 4 groups (n=20); group 1 received a single Ferrobloc bolus four weeks prior to CIDR insertion following 400 IU eCG on CIDR removal, group 2 received two boluses four weeks prior to CIDR insertion following 400 IU eCG on CIDR removal, group 3 received only 400 IU eCG on CIDR removal and group 4 (control) received no bolus and no eCG. Transrectal ultrasonography was done to monitor the ovarian follicles on the day of CIDR removal and a day later. Results showed that boluses increased the status of copper, selenium and iodine on mating day and days 90 to 100 of gestation. Ruminal bolus did not significantly increase the number of different classes of ovarian follicles in ewes fed a diet meeting all trace mineral requirements. All ewes eventually became pregnant with 1 or 2 boluses but the multiple births rate (80%) was higher (P<0.05) after 2 boluses compared to the other groups. PMID:27175153

Sampling solution traces for the problem of sorting permutations by signed reversals

Science.gov (United States)

2012-01-01

Background Traditional algorithms to solve the problem of sorting by signed reversals output just one optimal solution while the space of all optimal solutions can be huge. A so-called trace represents a group of solutions which share the same set of reversals that must be applied to sort the original permutation following a partial ordering. By using traces, we therefore can represent the set of optimal solutions in a more compact way. Algorithms for enumerating the complete set of traces of solutions were developed. However, due to their exponential complexity, their practical use is limited to small permutations. A partial enumeration of traces is a sampling of the complete set of traces and can be an alternative for the study of distinct evolutionary scenarios of big permutations. Ideally, the sampling should be done uniformly from the space of all optimal solutions. This is however conjectured to be ♯P-complete. Results We propose and evaluate three algorithms for producing a sampling of the complete set of traces that instead can be shown in practice to preserve some of the characteristics of the space of all solutions. The first algorithm (RA) performs the construction of traces through a random selection of reversals on the list of optimal 1-sequences. The second algorithm (DFALT) consists in a slight modification of an algorithm that performs the complete enumeration of traces. Finally, the third algorithm (SWA) is based on a sliding window strategy to improve the enumeration of traces. All proposed algorithms were able to enumerate traces for permutations with up to 200 elements. Conclusions We analysed the distribution of the enumerated traces with respect to their height and average reversal length. Various works indicate that the reversal length can be an important aspect in genome rearrangements. The algorithms RA and SWA show a tendency to lose traces with high average reversal length. Such traces are however rare, and qualitatively our results

Trace element content of precipitation in a remote area

International Nuclear Information System (INIS)

Merritt, W.F.

1976-01-01

Rain and snow, sampled over a period of 18 months at Chalk River Nuclear Laboratories, were analysed for 40 elements by thermal neutron activation analysis. Correlation analysis revealed that the elements detected could be divided into groups of similar behaviour. Storm tracks for the events sampled were obtained, but only generalizations as to the probable origin of the trace elements could be made. Deuterium content of the samples was not correlated with levels of trace elements. (author)

Trace mineral interactions during elevated calcium consumption

International Nuclear Information System (INIS)

Smith, K.T.; Luhrsen, K.R.

1986-01-01

Elevated calcium consumption is reported to affect trace mineral bioavailability. The authors examined this phenomenon in both single dose radio-label test meals and an eight week feeding trial in rats. In the single dose studies, human milk, cows milk, and various calcium sources were examined in relation to radio-iron and radio-zinc retention. 59 Fe retention was greater from human milk than cows milk. However, when the calcium content of human milk was adjusted (with CaHPO 4 or CaCO 3 ) to equal the level in cows milk, iron retention was depressed. Similarly, when calcium sources (CaCO 3 , CaHPO 4 , hydroxy-apatite, bone meal) were examined at different calcium:metal molar ratios, the degree of inhibition on metal retention varied. In general, phosphate salts were more inhibiting than carbonates. In the feeding trial, calcium was fed in diets at normal (0.5%) or elevated (1.5%) levels. Serum, liver, kidney, and bone trace mineral profiles were obtained. In general, most trace elements showed decreased levels in the tissues. Zinc and iron were most striking, followed by magnesium with minor changes in copper. A high calcium:high mineral supplemented group was also fed. Mixed mineral supplementation prevented all calcium interactions. These data indicate the importance of calcium mineral interactions in bioavailability considerations in both milk sources and in mineral supplementation

Mantle End-Members: The Trace Element Perspective

Science.gov (United States)

Willbold, M.; Stracke, A.; Hofmann, A. W.

2004-12-01

On the basis of their isotopic composition, ocean island basalts (OIB) have been classified into three to four end-members; HIMU with the most radiogenic Pb isotope ratios of OIB and Enriched Mantle 1 and 2 (EM1, EM2) with less radiogenic but variable Pb isotope and highly radiogenic Sr isotope signatures. It has also been argued that each of these isotopic families has common trace element characteristics that distinguish them from one another and so substantiated this classification. Here, we present new high-precision trace element data for samples from St. Helena, Tristan da Cunha and Gough in the Atlantic Ocean. The overall data-set is augmented by OIB data from the GEOROC database and includes data from all major isotopic families (HIMU: St. Helena, Mangaia, Tubuai, and Rururtu; EM1: Tristan da Cunha, Gough, Pitcairn; and EM2: Samoa, Marquesas, and Society). For each locality we use only islands defining the most extreme isotopic compositions. The entire data-set has been screened to exclude altered and highly differentiated samples. HIMU basalts have a very uniform trace element composition. Compared to HIMU-type basalts, EM-type basalts are enriched in Rb, Ba, and K, and depleted in U, Nb, and Ta, relative to La. Different EM-type OIBs from the same isotopic family (EM1 or EM2), have distinct trace element characteristics that can ultimately only be caused by different source compositions. For example, Ba/Th ratios in samples from both Tristan da Cunha (EM1) and Samoa (EM2) are similarly high (ca. 110) whereas Ba/Th ratios in samples from Pitcairn (EM1) and Society (EM2) samples are consistently lower (ca. 70). Thus on the basis of their trace element composition, EM-type OIB cannot be classified into EM1 and EM2 type basalts, nor can any other grouping be identified. The remarkably uniform isotopic and trace element composition of HIMU-type basalts suggests derivation from a single common source reservoir, most likely subduction-modified oceanic crust

Classic conditioning in aged rabbits: delay, trace, and long-delay conditioning.

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Solomon, P R; Groccia-Ellison, M E

1996-06-01

Young (0.5 years) and aged (2+, 3+, and 4+ years) rabbits underwent acquisition of the classically conditioned nictitating membrane response in a delay (500-ms conditioned stimulus [CS], 400-ms interstimulus interval [ISI]), long-delay (1,000-ms CS, 900-ms ISI), or trace (500-ms CS, 400-ms stimulus-free period) paradigm. Collapsing across age groups, there is a general tendency for animals to acquire trace conditioning more slowly than delay conditioning. Collapsing across conditioning paradigms, there is a general tendency for aged animals to acquire more slowly than younger animals. Of greater significance, however, are the age differences in the different conditioning paradigms. In the delay and long-delay paradigms, significant conditioning deficits first appeared in the 4(+)-year-old group. In the trace conditioning paradigm, significant conditioning deficits became apparent in the 2(+)-year-old animals.

Influence of enrofloxacin traces in drinking water to doxycycline tissue pharmacokinetics in healthy and infected by Mycoplasma gallisepticum broiler chickens.

Science.gov (United States)

Gbylik-Sikorska, Malgorzata; Posyniak, Andrzej; Sniegocki, Tomasz; Sell, Bartosz; Gajda, Anna; Sawicka, Anna; Olszewska-Tomczyk, Monika; Bladek, Tomasz; Tomczyk, Grzegorz; Zmudzki, Jan

2016-04-01

Most of antibiotics, administrated in the treatment of poultry diseases are dissolved in drinking water, and it can lead to water supply systems contamination, especially when the regular cleaning is not using. This situation can lead to unconscious administration of low doses of antibiotics to untreated animals. The aim of this study was to clarify the impact of the exposure of enrofloxacin traces (500 μg l(-1)) to doxycycline pharmacokinetics in healthy and experimentally Mycoplasma gallisepticum infected broiler chickens., Two experimental groups, received of enrofloxacin in water and all groups, received 20 mg kg(-1) bw of doxycycline. The compounds concentrations in muscles and livers were determined by LC-MS/MS. The maximum drug tissue concentration (Cmax) of doxycycline was highest in liver obtained from infected chickens which, received enrofloxacin traces (ENR + DC/MG). It was about 40% higher than in healthy chickens from group I which received only doxycycline. It was found that the concentration-time curve AUC(0-t) values in group ENR + DC/MG were almost 75% higher than in the group (DC) and 35% higher than in group (ENR + DC) which also received enrofloxacin traces. The constant exposure of broiler chickens on enrofloxacin traces as well as infection, may significantly influenced on doxycycline tissue pharmacokinetic profile. Copyright © 2016 Elsevier Ltd. All rights reserved.

Reverse ray tracing for transformation optics.

Science.gov (United States)

Hu, Chia-Yu; Lin, Chun-Hung

2015-06-29

Ray tracing is an important technique for predicting optical system performance. In the field of transformation optics, the Hamiltonian equations of motion for ray tracing are well known. The numerical solutions to the Hamiltonian equations of motion are affected by the complexities of the inhomogeneous and anisotropic indices of the optical device. Based on our knowledge, no previous work has been conducted on ray tracing for transformation optics with extreme inhomogeneity and anisotropicity. In this study, we present the use of 3D reverse ray tracing in transformation optics. The reverse ray tracing is derived from Fermat's principle based on a sweeping method instead of finding the full solution to ordinary differential equations. The sweeping method is employed to obtain the eikonal function. The wave vectors are then obtained from the gradient of that eikonal function map in the transformed space to acquire the illuminance. Because only the rays in the points of interest have to be traced, the reverse ray tracing provides an efficient approach to investigate the illuminance of a system. This approach is useful in any form of transformation optics where the material property tensor is a symmetric positive definite matrix. The performance and analysis of three transformation optics with inhomogeneous and anisotropic indices are explored. The ray trajectories and illuminances in these demonstration cases are successfully solved by the proposed reverse ray tracing method.

study on trace contaminants control assembly for sealed environment chamber

Science.gov (United States)

Pang, L. P.; Wang, J.; Liu, L. K.; Liu, H.

The biological and Physicochemical P C life support technologies are all important parts to establish a human Closed Ecological Life Support System CELSS for long-duration mission The latter has the advantages of lower power consumption lower mass and higher efficiency therefore researchers often incorporate the use of biological systems with P C life support technologies to continuously recycle air water and part of the solid waste stream generated such as the Russian BLSS and the NASA-sponsored Lunar-Mars Life Support Test Project LMLSTP In short these tests were very successful in integrating biological and P C life support technologies for long-duration life support Therefore we should use a combination of integrated biological with P C life support technologies in a human CELSS Human construction materials plants animals and soils release much trace toxic gases in a CELSS and they will inhibit plant growth and badly affect human health when their concentrations rise over their threshold levels The effect of biological trace contaminant control technologies is slower especially for a human sealed chamber because human produce much more methane and other contaminants A regenerative Trace Contaminant Control Subsystem TCCS with P C technology is a more important part in this case to control quickly the airborne contaminants levels and assure human in good condition in a sealed chamber This paper describes a trace contaminant control test facility incorporated a 8 m3 sealed environment chamber a regenerative TCCS with P C

Differential effects of acute cortisol administration on deep and shallow episodic memory traces: a study on healthy males.

Science.gov (United States)

Cioncoloni, David; Galli, Giulia; Mazzocchio, Riccardo; Feurra, Matteo; Giovannelli, Fabio; Santarnecchi, Emiliano; Bonifazi, Marco; Rossi, Alessandro; Rossi, Simone

2014-10-01

We aimed at investigating rapid effects of plasma cortisol elevations on the episodic memory phase of encoding or retrieval, and on the strength of the memory trace. Participants were asked either to select a word containing the letter "e" (shallow encoding task) or to judge if a word referred to a living entity (deep encoding task). We intravenously administered a bolus of 20mg of cortisol either 5 min before encoding or 5 min before retrieval, in a between-subjects design. The study included only male participants tested in the late afternoon, and neutral words as stimuli. When cortisol administration occurred prior to retrieval, a main effect of group emerged. Recognition accuracy was higher for individuals who received cortisol compared to placebo. The higher discrimination accuracy for the cortisol group was significant for words encoded during deep but not shallow task. Cortisol administration before encoding did not affect subsequent retrieval performance (either for deep or shallow stimuli) despite a facilitatory trend. Because genomic mechanisms take some time to develop, such a mechanism cannot apply to our findings where the memory task was performed shortly after the enhancement of glucocorticoid levels. Therefore, glucocorticoids, through non-genomic fast effects, determine an enhancement in episodic memory if administered immediately prior to retrieval. This effect is more evident if the memory trace is laid down through deep encoding operations involving the recruitment of specific neural networks. Copyright © 2014 Elsevier Inc. All rights reserved.

Effect of Trace Elements in Alcohol Beverages on the Type of Radiation-induced Cell Death

International Nuclear Information System (INIS)

Sohn, Jong Gi

2010-01-01

Developments of radioprotective agents are important issues for minimizing the troubles and the effective treatments in radiotherapy. But few agents are useful in clinical and practical fields. It was shown that trace elements in alcohol beverages might have radioprotective effect. In this study, the types of cell death of lymphocytes according to the commercial alcohol beverage was investigated. Normal healthy volunteers ingested distilled water, beer or soju containing 8.15 mg·dl -1 ethyl ahcohol, respectively. After 2 hours, their blood were sampled with their consents. Fraction of lymphocytes was isolated by density gradient method with Histopaque-1077 (Sigma) and irradiated with dose from 0.5 to 5 Gy. After 60 hour incubation, the cells were harvested and analysed by flow cytometry. Cell viability was decreased by dose dependent manner. Cell viability of beer group was reduced about 15% compared with control group. Apoptosis in soju group was reduced about 20% compared with control group. Apoptosis of beer and control groups are similar. Necrosis of soju group significantly increased about 35% compared with control group. Early apoptosis of beer group was increased compared with control group. Early apoptosis of soju group was decreased about 25% compared with control group. Late apoptosis of beer and control group was increased by dose dependent manner. Late apoptosis of soju group was increased about 20-30% compared with control group. Late apoptosis of soju was increased and the radioprotective effect of soju was minimal because late apoptosis induced the cell necrosis. In case of soju trace elements, total cell apoptosis was decreased about 20% and early cell apoptosis was remarkably low. In this case, mitotic cells death may be dominant mechanism. Therefore, trace elements in soju may not be effective radioprotective agents

Effects of OEF/OIF-Related Physical and Emotional Co-Morbidities on Associative Learning: Concurrent Delay and Trace Eyeblink Classical Conditioning

Directory of Open Access Journals (Sweden)

Regina E. McGlinchey

2014-03-01

Full Text Available This study examined the performance of veterans and active duty personnel who served in Operation Enduring Freedom and/or Operation Iraqi Freedom (OEF/OIF on a basic associative learning task. Eighty-eight individuals participated in this study. All received a comprehensive clinical evaluation to determine the presence and severity of posttraumatic stress disorder (PTSD and traumatic brain injury (TBI. The eyeblink conditioning task was composed of randomly intermixed delay and trace conditioned stimulus (CS and unconditioned stimulus (US pairs (acquisition followed by a series of CS only trials (extinction. Results revealed that those with a clinical diagnosis of PTSD or a diagnosis of PTSD with comorbid mTBI acquired delay and trace conditioned responses (CRs to levels and at rates similar to a deployed control group, thus suggesting intact basic associative learning. Differential extinction impairment was observed in the two clinical groups. Acquisition of CRs for both delay and trace conditioning, as well as extinction of trace CRs, was associated with alcoholic behavior across all participants. These findings help characterize the learning and memory function of individuals with PTSD and mTBI from OEF/OIF and raise the alarming possibility that the use of alcohol in this group may lead to more significant cognitive dysfunction.

Trace elements in several species of crustaceans of Amami Island Group in Japan determined by activation analysis

International Nuclear Information System (INIS)

Fukushima, M.; Tamate, H.; Nakano, Y.

2001-01-01

Concentration levels of trace elements were determined in several species of subtropical crustaceans from Amami Islands in Japan in order to evaluate the levels of specific accumulation of elements among species. Tissue samples prepared from gill, muscle, hepatopancreas, and testis were irradiated for photon activation analysis (PAA) and neutron activation analysis (NAA). By PAA and NAA, eighteen elements could be determined. The levels of Br and I were extremely high in gills of spiny lobster and shovel-nosed lobster, respectively. A high concentration of Ag was found in the hepatopancreas of spiny lobsters collected from the Amami Island, while this element was not detected in the same species collected from Toba. The results suggest that the distribution of the trace elements in different tissues and species varies according to both species and environmental differences. To study the molecular forms of the elements in tissue, fractions that contained protein-bound elements from the hepatopancreas of spiny lobsters were separated by ultracentrifugation and gel filtration chromatography. Elution profiles of the chromatography suggest that Cu, Fe, and Se were bound to proteins, while Ag was not. (author)

Stabilisation de la formule des traces tordue

CERN Document Server

Moeglin, Colette

2016-01-01

Ce travail en deux volumes donne la preuve de la stabilisation de la formule des trace tordue. Stabiliser la formule des traces tordue est la méthode la plus puissante connue actuellement pour comprendre l'action naturelle du groupe des points adéliques d'un groupe réductif, tordue par un automorphisme, sur les formes automorphes de carré intégrable de ce groupe. Cette compréhension se fait en réduisant le problème, suivant les idées de Langlands, à des groupes plus petits munis d'un certain nombre de données auxiliaires; c'est ce que l'on appelle les données endoscopiques. L'analogue non tordu a été résolu par J. Arthur et dans ce livre on suit la stratégie de celui-ci. Publier ce travail sous forme de livre permet de le rendre le plus complet possible. Les auteurs ont repris la théorie de l'endoscopie tordue développée par R. Kottwitz et D. Shelstad et par J.-P. Labesse. Ils donnent tous les arguments des démonstrations même si nombre d'entre eux se trouvent déjà dans les travaux d'Ar...

A comparison of pecking generated by serial, delay, and trace autoshaping procedures1

Science.gov (United States)

Newlin, Robert J.; LoLordo, Vincent M.

1976-01-01

Pigeons were exposed to serial, delay, and trace autoshaping procedures. In Experiment I, all conditioned stimuli (CSs) were changes in illumination of the response key. The number of trials to acquisition of the keypeck increased from serial, to 4-sec delay, 8-sec delay, and 8-sec trace procedures, in that order. In Experiment II, which used a longer intertrial interval, trials to criterion increased from 8-sec delay, to 28-sec delay, 8-sec trace, and 28-sec trace procedures, in that order. In Experiment III, two groups received serial procedures in which the first CS was either a tone or a houselight, and the second was a keylight. The tone group acquired the key peck more rapidly than the houselight group. Early in conditioning in these experiments, and when the conditioned stimulus was a change in the keylight, there was a short latency to the onset of pecking and pecking was directed at the CS. After extensive conditioning, or when the CS was relatively diffuse, pecking still occurred, but had a longer latency and was not reliably directed toward the conditioned stimulus. PMID:16811907

PIXE determination of essential trace elements in some traditional Chinese medicines

International Nuclear Information System (INIS)

Xiao, L.; Qin, J.F.

1990-01-01

The essential trace elements in 30 traditional Chinese medicines, (24 tonics and 6 nontonics) were determined by proton-induced X-ray emission. The authors' previous suggestion that traditional Chinese medicines may be classified by the order of magnitude of their essential trace elements, thus indicating their pharmacological effects, is not justified. The pharmacological effect of a trace element or its essentiality may be dependent on some ligand that can be chelated with it. A nonlinear mapping algorithm, however, shows that the 30 traditional Chinese medicines are nearly separated into two groups, indicating their tonic or nontonic pharmacological effects

Study of heavy trace metals in some medicinal-herbal plants of Pakistan

International Nuclear Information System (INIS)

Khattak, M.I.

2011-01-01

The paper presents heavy trace metals analysis in some widely used medicinal- herbal plants of Pakistan by using Inductively Coupled Plasma. Because these commonly used medicinal- herbal plants from Pakistan are being specifically utilized for the treatment of various diseases, so samples of medicinal-herbal plants were collected from open market and from the fields. Collected samples were digested and analyzed for their nutritional trace metals (Pb, Cd, Fe, Zn, Ni, Cu and Mn) composition and then the results obtained were compared to international and national standards as required by World Health Organizations. The deficiency or excess of the samples for essential trace metals are reported. (author)

Nuclear traces in glass

International Nuclear Information System (INIS)

Segovia A, M. de N.

1978-01-01

The charged particles produce, in dielectric materials, physical and chemical effects which make evident the damaged zone along the trajectory of the particle. This damaged zone is known as the latent trace. The latent traces can be enlarged by an etching of the detector material. This treatment attacks preferently the zones of the material where the charged particles have penetrated, producing concavities which can be observed through a low magnification optical microscope. These concavities are known as developed traces. In this work we describe the glass characteristics as a detector of the fission fragments traces. In the first chapter we present a summary of the existing basic theories to explain the formation of traces in solids. In the second chapter we describe the etching method used for the traces development. In the following chapters we determine some chatacteristics of the traces formed on the glass, such as: the development optimum time; the diameter variation of the traces and their density according to the temperature variation of the detector; the glass response to a radiation more penetrating than that of the fission fragments; the distribution of the developed traces and the existing relation between this ditribution and the fission fragments of 252 Cf energies. The method which has been used is simple and cheap and can be utilized in laboratories whose resources are limited. The commercial glass which has been employed allows the registration of the fission fragments and subsequently the realization of experiments which involve the counting of the traces as well as the identification of particles. (author)

The role of sample preparation in interpretation of trace element concentration variability in moss bioindication studies

Science.gov (United States)

Migaszewski, Z.M.; Lamothe, P.J.; Crock, J.G.; Galuszka, A.; Dolegowska, S.

2011-01-01

Trace element concentrations in plant bioindicators are often determined to assess the quality of the environment. Instrumental methods used for trace element determination require digestion of samples. There are different methods of sample preparation for trace element analysis, and the selection of the best method should be fitted for the purpose of a study. Our hypothesis is that the method of sample preparation is important for interpretation of the results. Here we compare the results of 36 element determinations performed by ICP-MS on ashed and on acid-digested (HNO3, H2O2) samples of two moss species (Hylocomium splendens and Pleurozium schreberi) collected in Alaska and in south-central Poland. We found that dry ashing of the moss samples prior to analysis resulted in considerably lower detection limits of all the elements examined. We also show that this sample preparation technique facilitated the determination of interregional and interspecies differences in the chemistry of trace elements. Compared to the Polish mosses, the Alaskan mosses displayed more positive correlations of the major rock-forming elements with ash content, reflecting those elements' geogenic origin. Of the two moss species, P. schreberi from both Alaska and Poland was also highlighted by a larger number of positive element pair correlations. The cluster analysis suggests that the more uniform element distribution pattern of the Polish mosses primarily reflects regional air pollution sources. Our study has shown that the method of sample preparation is an important factor in statistical interpretation of the results of trace element determinations. ?? 2010 Springer-Verlag.

Preliminary studies on trace element contamination in dumping sites of municipal wastes in India and Vietnam

Science.gov (United States)

Agusa, T.; Kunito, T.; Nakashima, E.; Minh, T. B.; Tanabe, S.; Subramanian, A.; Viet, P. H.

2003-05-01

The disposal of wastes in dumping sites has increasingly caused concem about adverse health effects on the populations living nearby. However, no investigation has been conducted yet on contamination in dumping sites of municipal wastes in Asian developing countries. In this study, concentrations of 11 trace elements (V, Cr, Mn, Co, Cu, Zn, Mo, Ag, Cd, Sb and Pb) were detennined in scalp hair from the population living nearby and in soil from dumping sites and control sites of India and Vietnam. Soil samples in dumping site in India showed significantly higher concentrations of some trace elements than soils in control site, whereas this trend was not notable in Vietnam. This is probably due to the fact that the wastes were covered with the soil in the dumping site of Vietnam. Cadmium concentrations in some hair samples of people living near dumping site in India and Vietnam exceeded the level associated with learning disorder in children. Levels of most of the trace elements in hair were significantly higher in dumping site than those in control site in India and Vietnam, suggesting direct or indirect exposure to those elements from dumping wastes. To our knowledge, this is the first study of trace element contamination in dumping sites in India and Vietnam.

TraceContract: A Scala DSL for Trace Analysis

Science.gov (United States)

Barringer, Howard; Havelund, Klaus

2011-01-01

In this paper we describe TRACECONTRACT, an API for trace analysis, implemented in the SCALA programming language. We argue that for certain forms of trace analysis the best weapon is a high level programming language augmented with constructs for temporal reasoning. A trace is a sequence of events, which may for example be generated by a running program, instrumented appropriately to generate events. The API supports writing properties in a notation that combines an advanced form of data parameterized state machines with temporal logic. The implementation utilizes SCALA's support for defining internal Domain Specific Languages (DSLs). Furthermore SCALA's combination of object oriented and functional programming features, including partial functions and pattern matching, makes it an ideal host language for such an API.

Studies in the Philippines on ingestion and organ content of trace elements of importance to radiological protection

International Nuclear Information System (INIS)

Natera, E.S.

1998-01-01

The first Coordinated Research Program on Reference Asian Man (RAM) was conducted for a period of six years. The study dealt with the collection of data in four areas namely: (1) anthropometric measurements, (2) organ mass measurements, (3) nutritional and dietary intake, and (4) pulmonary and water balance studies. Based on the research needs with reference to radiation protection, dietary intake and tissue analysis appear to be important aspects of the RAM. Information to be generated from the elemental analysis of food and tissue would be used to characterize the intake, retention and release of radioactive elements coming from different population groups. This study also aims to establish the elemental composition profile of the average Filipino using simple and accurate methods of measurements. This report will present the protocol which is based to the extent possible on prescribed procedures required for the study. A standardized Protocol to be used in the study is important since stable elements are present only in trace quantities in biological samples of interest. The procedures presented in this document include: collection of one day diet samples and tissue samples (lung, liver, skeletal muscle, thyroid, bone and kidney) from average healthy adult Filipino. The sample treatment and preparation, analytical measurements, data evaluation and reporting will complete said protocol. The elements that are of importance to radiation protection are iodine, cesium, strontium, thorium, and uranium. The essential minor elements are calcium, potassium and sodium. Trace elements like copper. manganese, iron, selenium and zinc will also be included in the analysis. Concentrations of common toxic elements such as mercury, cadmium and lead may likewise be reported in this study. (author)

The spatial profile of visual attention in mental curve tracing

NARCIS (Netherlands)

Scholte, H. S.; Spekreijse, H.; Roelfsema, P. R.

2001-01-01

In a curve-tracing task, subjects have to judge whether items are located on a single, continuous curve. Spatially separate segments of such a curve are related to each other through grouping criteria, like collinearity and connectedness. These grouping cues need to be exploited during curve

Screening for trace explosives by AccuTOF™-DART®: an in-depth validation study.

Science.gov (United States)

Sisco, Edward; Dake, Jeffrey; Bridge, Candice

2013-10-10

Ambient ionization mass spectrometry is finding increasing utility as a rapid analysis technique in a number of fields. In forensic science specifically, analysis of many types of samples, including drugs, explosives, inks, bank dye, and lotions, has been shown to be possible using these techniques [1]. This paper focuses on one type of ambient ionization mass spectrometry, Direct Analysis in Real Time Mass Spectrometry (DART-MS or DART), and its viability as a screening tool for trace explosives analysis. In order to assess viability, a validation study was completed which focused on the analysis of trace amounts of nitro and peroxide based explosives. Topics which were studied, and are discussed, include method optimization, reproducibility, sensitivity, development of a search library, discrimination of mixtures, and blind sampling. Advantages and disadvantages of this technique over other similar screening techniques are also discussed. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Baring the teeth. [Dental caries and the analysis of trace elements in dental tissues

Energy Technology Data Exchange (ETDEWEB)

Cleaton-Jones, P [University of the Witwatersrand, Johannesburg (South Africa). Dental Research Unit; Retief, H [Alabama Univ., Birmingham (USA); Turkstra, J [Fort Hare Univ. (South Africa). Dept. of Chemistry

1979-07-01

To determine whether trace elements other than fluorine play a role in the varying prevalences of dental caries in different South African population groups, neutron activation techniques have been devised to establish the concentrations of trace elements in tooth enamel and dentine.

Study on SF6 trace experiment in Lianyungang Nuclear Power Plant

International Nuclear Information System (INIS)

Hu Erbang; Yan Jiangyu; Zhang Yongyi; Wen Lianzhong

2001-01-01

10 times SF 6 trace experiments were successfully performed in August 1997 on a very complex terrain of Lianyungang Nuclear Power Plant in order to obtain plume trajectory and diffusion parameters. SF 6 is released from the top of a tower of 100 m. The sample points are arranged not only on the sample lines but also on the areas near residences. About 50 samples are obtained in each SF 6 trace experiment. The samples of SF 6 are analysed by the GC-ECD method. The weather stability is 5 times C and D stabilities respectively if using P-G method or 10 times D stabilities if using ΔT-U method. A least-square method is adopted to obtain the diffusion parameters from diffusion equation. Meanwhile the effect on the diffusion parameters from sampling time is measured based on the above SF 6 trace experiment

TRACE/PARCS modelling of rips trip transients for Lungmen ABWR

Energy Technology Data Exchange (ETDEWEB)

Chang, C. Y. [Inst. of Nuclear Engineering and Science, National Tsing-Hua Univ., No.101, Kuang-Fu Road, Hsinchu 30013, Taiwan (China); Lin, H. T.; Wang, J. R. [Inst. of Nuclear Energy Research, No. 1000, Wenhua Rd., Longtan Township, Taoyuan County 32546, Taiwan (China); Shih, C. [Inst. of Nuclear Engineering and Science, Dept. of Engineering and System Science, National Tsing-Hua Univ., No.101, Kuang-Fu Road, Hsinchu 30013, Taiwan (China)

2012-07-01

The objectives of this study are to examine the performances of the steady-state results calculated by the Lungmen TRACE/PARCS model compared to SIMULATE-3 code, as well as to use the analytical results of the final safety analysis report (FSAR) to benchmark the Lungmen TRACE/PARCS model. In this study, three power generation methods in TRACE were utilized to analyze the three reactor internal pumps (RIPs) trip transient for the purpose of validating the TRACE/PARCS model. In general, the comparisons show that the transient responses of key system parameters agree well with the FSAR results, including core power, core inlet flow, reactivity, etc. Further studies will be performed in the future using Lungmen TRACE/PARCS model. After the commercial operation of Lungmen nuclear power plant, TRACE/PARCS model will be verified. (authors)

Trace contaminants of agriculture, fisheries and food with particular reference to isotope studies

International Nuclear Information System (INIS)

Winteringham, F.P.W.

1977-01-01

Growing world population, industrilization and intensification of agricultural and fisheries practices have greatly increased the need during recent decades to protect the resources concerned, and the quality of food and agricultural environment. These trends have also resulted in a growing range of trace contaminants and excessive nutrient problems of agriculture and fisheries. Isotopic tracer and nuclear analytical techniques are powerful and often unique tools for the study and control of the problems, especially in relation to trace elements, nutrients and contaminants. In addition to the conventional use of radioactive and stable isotopes as tracers there appears to be considerable scope for the use of environmental or natural isotope ratio techniques and the use of labelled reagents and substrates as monitoring tools. Representative applications are described. (author)

Trace elements in human milk. Part of a coordinated programme on comparative methods for the study of trace elements in human nutrition

International Nuclear Information System (INIS)

Kosta, L.

1981-01-01

New analytical methods based on radiochemical neutron activation analysis were developed for the determination of Sn, V, I and Se at nanogram levels in biological materials, particularly in milk and other foodstuffs. By the application of these and similar methods, results for trace elements in human and cow's milk were collected from which the normal concentration ranges of up to 12 trace elements were established. Significant data on vanadium levels were also collected allowing assessment of the dietary intake and body pool of this element and a reappraisal of its significance in nutrition. Similar data on a smaller scale were also collected for tin. Results were also obtained for several different trace elements in a range of biological reference materials

Strontium isotopic and trace element geochemistry of the saddle mountains and Grande Ronde Basalts of the Columbia River Basalt Group

International Nuclear Information System (INIS)

Nelson, D.O.

1980-01-01

The Columbia River Basalt (CRB) group displays significant variations in major and trace element and Sr isotopic compositions. These compositions reflect complex and variable origins for the CRB magmas. Among the most varied is the Saddle Mountains Basalt (SMB) in which Sr ratios vary from 0.7078 to 0.7147 +- 0.002. The higher ratios reflect contamination through consistent correlations with major element compositions. Modeling suggests contamination by assimilation of 4.4 to 9.4 wt % of radiogenic crustal rocks. High delta 18 O values (up to +7.68 per mil) support the model. Age and field relations suggest that the contamination flowrocks are not the result of progressive contamination of a single magma, but rather reflect the contamination of independent magmas during this ascent

Analysis of Hair Trace Elements in Children with Autism Spectrum Disorders and Communication Disorders.

Science.gov (United States)

Skalny, Anatoly V; Simashkova, Natalia V; Klyushnik, Tatiana P; Grabeklis, Andrei R; Radysh, Ivan V; Skalnaya, Margarita G; Tinkov, Alexey A

2017-06-01

The primary objective of the present study is analysis of hair trace elements content in children with communication disorder (CD) and autism spectrum disorder (ASD). A total of 99 children from control, CD, and ASD groups (n = 33) were examined. All children were additionally divided into two subgroups according to age. Hair levels of trace elements were assessed using inductively coupled plasma mass spectrometry. The difference was considered significant at p elements including the toxic ones, it can be proposed that children suffering from ASD are characterized by more profound alteration of metal handling and excretion in comparison to CD.

Natural analogue study on trace element migration in geological formation at Horonobe area, Japan

International Nuclear Information System (INIS)

Iwatsuki, Teruki; Ishii, Eiichi; Mizuno, Takashi; Honda, T.

2010-01-01

Usefulness of natural analog to study radionuclide transport models for deep geological repositories for high-level and long lived radioactive wastes is widely recognized. As the groundwater flow in the Horonobe area, Hokkaido, Japan is known to be stationary with neutral pH value and of reductive nature for a long-term, the authors began natural analog study by observing atomic distribution of such trace elements as rare earths, uranium, and thorium in carbonate nodules and veins of uranium minerals from several selected faults (Wakkanai F., Ketoi F., etc) in the area with the use of XED, XRF, and ICP-MS. The results give important information as to the maintainability of the rocks for trace elements and help to provide confidence in the safety assessment in the long term. (S. Ohno)

Trace analysis

International Nuclear Information System (INIS)

Warner, M.

1987-01-01

What is the current state of quantitative trace analytical chemistry? What are today's research efforts? And what challenges does the future hold? These are some of the questions addressed at a recent four-day symposium sponsored by the National Bureau of Standards (NBS) entitled Accuracy in Trace Analysis - Accomplishments, Goals, Challenges. The two plenary sessions held on the first day of the symposium reviewed the history of quantitative trace analysis, discussed the present situation from academic and industrial perspectives, and summarized future needs. The remaining three days of the symposium consisted of parallel sessions dealing with the measurement process; quantitation in materials; environmental, clinical, and nutrient analysis; and advances in analytical techniques

Trace Element Abundances in Eucrite Basalts: Enrichment or Depletion?

Science.gov (United States)

Castle, N. R.

2018-05-01

It is not clear how incompatible trace element (ITE) variation in eucrite basalts originated. Here, mechanisms for relative ITE enrichment or depletion are experimentally evaluated in an attempt to reconcile the Stannern and main group eucrites.

Analysis of trace elements in scalp hair for long-lived people, hypertensives and healthy students

International Nuclear Information System (INIS)

Wu Xiaofeng; Zhang Yurong; Zhang Longxing; Zhang Agen

1989-01-01

The XRF method was used to analyse nine kinds of trace elements in hair samples for three groups of people. While the information on long-lived people is used to explore the secret of long life, the work on hypertensives helps understand the effect of some trace elements on the disease. The normal values of trace elements for university students have been also set up

Anisotropic ray trace

Science.gov (United States)

Lam, Wai Sze Tiffany

anisotropic ray tracing. x. Chapter 4 presents the data reduction of the P matrix of a crystal waveplate. The diattenuation is embedded in the singular values of P. The retardance is divided into two parts: (A) The physical retardance induced by OPLs and surface interactions, and (B) the geometrical transformation induced by geometry of a ray path, which is calculated by the geometrical transform Q matrix. The Q matrix of an anisotropic intercept is derived from the generalization of s- and p-bases at the anisotropic intercept; the p basis is not confined to the plane of incidence due to the anisotropic refraction or reflection. Chapter 5 shows how the multiple P matrices associated with the eigenmodes resulting from propagation through multiple anisotropic surfaces can be combined into one P matrix when the multiple modes interfere in their overlapping regions. The resultant P matrix contains diattenuation induced at each surface interaction as well as the retardance due to ray propagation and total internal reflections. The polarization aberrations of crystal waveplates and crystal polarizers are studied in Chapter 6 and Chapter 7. A wavefront simulated by a grid of rays is traced through the anisotropic system and the resultant grid of rays is analyzed. The analysis is complicated by the ray doubling effects and the partially overlapping eigen-wavefronts propagating in various directions. The wavefront and polarization aberrations of each eigenmode can be evaluated from the electric field distributions. The overall polarization at the plane of interest or the image quality at the image plane are affected by each of these eigen-wavefronts. Isotropic materials become anisotropic due to stress, strain, or applied electric or magnetic fields. In Chapter 8, the P matrix for anisotropic materials is extended to ray tracing in stress birefringent materials which are treated as spatially varying anisotropic materials. Such simulations can predict the spatial retardance variation

Zeta functions and regularized determinants related to the Selberg trace formula

DEFF Research Database (Denmark)

Momeni, Arash; Venkov, Alexei

determinants of one dimensional Schroedinger operator for harmonic oscillator. We decompose the determinant of the automorphic Laplacian into a product of the determinants where each factor is a determinant representation of a zeta function related to Selberg's trace formula. Then we derive an identity...... connecting the determinants of the automorphic Laplacians on different Riemannian surfaces related to the arithmetical groups. Finally, by using the Jacquet-Langlands correspondence we connect the determinant of the automorphic Laplacian for the unit group of quaternions to the product of the determinants......For a general Fuchsian group of the first kind with an arbitrary unitary representation we define the zeta functions related to the contributions of the identity, hyperbolic, elliptic and parabolic conjugacy classes in Selberg's trace formula. We present Selberg's zeta function in terms...

Traces of heavy and superheavy cosmic nuclei in olivins of extraterrestial origin

International Nuclear Information System (INIS)

Ignatova, R.; Taneva, T.

1982-01-01

The paths of traces of WH nuclei from cosmic rays have been measured in olivines from the meteorites Maryalakhti, Eagle Stein, Liposki khutor with radiation ages 175, 45 and 220 million years respectively. 3 cm 3 olivines of these meteorites have been examined and more than 500 traces of nuclei with Z(>=)90 have been found measured including 3 traces 1.5-1.8 times longer than the traces created by the uranium and thorium nuclei. These traces may be left by nuclei with Z(>=)110. The crystals were chosen from localizations situated at 2-7 cm, 8-9 cm and 10-12 cm from the outside atmospheric surface of the meteorite. The abundancy of the Z(>=)50 nuclei in gigantic cosmic rays, averaged for a period of ( =)110 in galactic cosmic rays. It is 1.4 x 10 -9 from that of the iron group nuclei. (authors)

Long-term memory traces for language sounds are highly context-sensitive: an MEG/ERF study

DEFF Research Database (Denmark)

Nielsen, Andreas Højlund; Gebauer, Line; Mcgregor, William

impact on the proposed long-term memory traces for native phonological categories. In order to generate different MMF responses to the same language sound contrast depending on the phonetic context, these long-term memory traces must thus be context-sensitive themselves or exist as separate traces...

A new method for automated discontinuity trace mapping on rock mass 3D surface model

Science.gov (United States)

Li, Xiaojun; Chen, Jianqin; Zhu, Hehua

2016-04-01

This paper presents an automated discontinuity trace mapping method on a 3D surface model of rock mass. Feature points of discontinuity traces are first detected using the Normal Tensor Voting Theory, which is robust to noisy point cloud data. Discontinuity traces are then extracted from feature points in four steps: (1) trace feature point grouping, (2) trace segment growth, (3) trace segment connection, and (4) redundant trace segment removal. A sensitivity analysis is conducted to identify optimal values for the parameters used in the proposed method. The optimal triangular mesh element size is between 5 cm and 6 cm; the angle threshold in the trace segment growth step is between 70° and 90°; the angle threshold in the trace segment connection step is between 50° and 70°, and the distance threshold should be at least 15 times the mean triangular mesh element size. The method is applied to the excavation face trace mapping of a drill-and-blast tunnel. The results show that the proposed discontinuity trace mapping method is fast and effective and could be used as a supplement to traditional direct measurement of discontinuity traces.

Wet deposition flux of trace elements to the Adirondack region

International Nuclear Information System (INIS)

Huang, X.; Keskin, S.S.; Gullu, G.; Olmez, I.

2001-01-01

Wet deposition samples from two locations in the Adirondack region of New York were analyzed for trace elemental composition by instrumental neutron activation analysis. Annual fluxes of the measured species were determined by precipitation-weighted and linear-regression methods. Despite several episodes of high deposition fluxes, the cumulative areal wet deposition of trace elements increased fairly linearly (r 2 > 0.9) over the two year sampling period at both sites. This implies that short duration sampling programs may be used to estimate long-term fluxes and cumulative wet deposition impacts. Based on the magnitude of their fluxes, the measured species have been divided into four groups: acidic anions, electroneutral balancing cations, and minor and trace elements of anthropogenic origin. (author)

Study in Vietnam on ingestion and organ content of trace elements of importance in radiological protection (I, Cr, Sr, Th, U etc.)

International Nuclear Information System (INIS)

Nguyen Mong Sinh

1998-01-01

To study on ingestion and organ content of trace elements of importance in Radiological Protection for population in Vietnam we need to select representative population groups. This can be done using some basic information about relevant ethnic, socioeconomic and geographical factors of Vietnam. It is also very importance to know the average food consumption, a characteristics and nutritive value of Vietnamese diet and the daily nutritional intake for this population groups. A general discussion have been made on proposal of sample collection, using analytical techniques to determine the elements of interest. There are also some primary results of analysis of iodine content in different kinds of foodstuffs in natural water and human urine. (author)

Trace element characteristics of mafic and ultramafic meta-igneous rocks from the 3.5 Ga. Warrawoona group: evidence for plume-lithosphere interaction beneath Archaean continental crust

International Nuclear Information System (INIS)

Bolhar, R.; Hergt, J.; Woodhead, J.

1999-01-01

Full text: Magnesian- to Fe-rich tholeiitic basalts represent the dominant lithology in the Marble Bar Greenstone Belt, E-Pilbara Craton, and are locally associated with komatiitic basalts and rare komatiitic cumulates. Based on trace element characteristics, the extrusive and intrusive rocks from all three major stratigraphic units can be subdivided into LREE enriched and unfractionated to weakly LREE depleted groups. The former group is characterized by La/Sm pm = 1.7-4.6, Gd/Yb pm = 1.23.2 and Nb/Th pm 0.1-0.5, while the latter rocks possess ratios of La/Sm pm = 0.5-1.7, Gd/Yb pm = 0.8-1.9 and Nb/Th pm = 0.4-1.3. Nb/La -Nb/Th relationships in the LREE enriched samples indicate 7-28% contamination by crustal material similar in composition to Pilbara granitoids. LREE enrichment and strong negative HFSE anomalies, along with MgO = 2.2-22.0 wt% and SiO 2 = 39.2-63.5 wt%, have been observed in numerous Archaean greenstone belts, and can be successfully modeled in this study by AFC processes. In contrast, strong HFSE depletion combined with unfractionated to slightly depleted LREE in rocks of the latter group require different processes. Melting of mantle material previously depleted by melt extraction, enrichment of LILE and LREE relative to the HFSE in an arc-like environment and HFSE fractionation as a result of garnet retention in the melting source cannot account for negative Nb, Ta, Ti, P and strong positive Pb anomalies. Introduction of small amounts of crustal material into a depleted or primitive mantle, as possibly indicated by Nb/Ta ratios between 12 and 18, also fails to reproduce the trace element abundances of the second group of rocks. Recycling of oceanic crust previously processed through a subduction zone (low Th/Nb, La/Nb) and sub-arc lithospheric mantle (high Th/Nb, La/Nb), and subsequent mixing into the Archaean mantle has been recently invoked by several workers (e.g. Kerrich et al., EPSL, 168, 101-115; 1999) to explain the origin of

Study on trace elements in gangue in Huainan mining area

Energy Technology Data Exchange (ETDEWEB)

Cai, F.; Liu, Z.; Lin, B.; Li, W.; Lu, Z. [Anhui University of Science and Technology, Huainan (China)

2008-08-15

46 samples were gathered from coal seams and rocks of various lithological types. In these samples, trace elements were analyzed by inductively coupled plasma-mass spectrometry (IAP-MS)and instrumental neutron activation analysis (IAA). Hg was analyzed by cold-vapor atomic absorption spectrometry (KVASS), F by ion-selective electrode (IS) and major elements by chemical methods. Eleven trace elements (Cd, Cu, Ni, Sn, Hg, Mn, As, Cr, Pb, Zn, F) were selected for study, and five of them, Cd, Cu, Ni, Sn, Hg, were above the background soil level (B.L.) of Huainan City, China and world averages. Respectively: Cd is 40 and 7 times the B.L. of Huainan City and the world; Cu is about 2 and 1.5 times the B.L. of Huainan City and the world; Ni is 8 and 7 times the B.L. of Huainan City and the world; Sn is 3 and 2 times the B.L. of Huainan City and the world; and Hg is 3,602 and 1,381 times the B.L. of Huainan City and the world. Their hazards caused to the environment of the mining area are explored primarily. It is thought that their hazards may be cumulative. 15 refs., 1 fig., 3 tabs.

Diffusion tensor trace mapping in normal adult brain using single-shot EPI technique: A methodological study of the aging brain

International Nuclear Information System (INIS)

Chen, Z.G.; Hindmarsh, T.; Li, T.Q.

2001-01-01

Purpose: To quantify age-related changes of the average diffusion coefficient value in normal adult brain using orientation-independent diffusion tensor trace mapping and to address the methodological influences on diffusion quantification. Material and Methods: Fifty-four normal subjects (aged 20-79 years) were studied on a 1.5-T whole-body MR medical unit using a diffusion-weighted single-shot echo-planar imaging technique. Orientation-independent diffusion tensor trace maps were constructed for each subject using diffusion-weighted MR measurements in four different directions using a tetrahedral gradient combination pattern. The global average (including cerebral spinal fluid) and the tissue average of diffusion coefficients in adult brains were determined by analyzing the diffusion coefficient distribution histogram for the entire brain. Methodological influences on the measured diffusion coefficient were also investigated by comparing the results obtained using different experimental settings. Results: Both global and tissue averages of the diffusion coefficient are significantly correlated with age (p<0.03). The global average of the diffusion coefficient increases 3% per decade after the age of 40, whereas the increase in the tissue average of diffusion coefficient is about 1% per decade. Experimental settings for self-diffusion measurements, such as data acquisition methods and number of b-values, can slightly influence the statistical distribution histogram of the diffusion tensor trace and its average value. Conclusion: Increased average diffusion coefficient in adult brains with aging are consistent with findings regarding structural changes in the brain that have been associated with aging. The study also demonstrates that it is desirable to use the same experimental parameters for diffusion coefficient quantification when comparing between different subjects and groups of interest

Consumer perception of Brazilian traced beef

Directory of Open Access Journals (Sweden)

Júlio Otávio Jardim Barcellos

2012-03-01

Full Text Available The objective of this study was to determine consumers understanding of beef traceability, identifying how consumers value this meat and traceability elements to be presented on retail shelves. The method used in this study was a survey through the internet applying the Sphinx software. The sample consisted of 417 consumers, mostly living in Porto Alegre, Brazil. Consumers are aware of certified beef, consider it important, but this is not a demand. As to traced beef, most consumers (62.4% are in favor of mandatory traceability of beef cattle in Brazil, but 86.6% disagree with the destination of traced beef only to the foreign market. The majority of people are willing to pay more for traced beef and consider traceability a market opportunity, used as a differentiating tool.

Trace and rare earth elements fractionation in volcanic- and sediment-hosted Mn ores: a study case of Sardinia (western Italy).

Science.gov (United States)

Sinisi, Rosa

2015-04-01

It is widely accepted that, regardless of the geological environment (continental, marine or hydrothermal), the occurrences of clay minerals and/or mineral phases with clay-type crystal structure (as zeolites and Mn-oxides), play a key role in the trace elements and REEs uptake processes. The REE resources are produced mostly from ion-adsorption type REE deposits of southern China that are formed by weathering of granitic rocks and subsequent chemical adsorption of REE on clay minerals. A significant group of minerals with a high metal uptake capacity is represented by Mn oxides. Their "tunnel" structure, in fact, allows both the absorption (inside the minerals) and adsorption (outside the minerals) of cations and anions producing metal accumulations with economic and environmental significance. However, the ores, mainly that forming within sedimentary environment, often have impurities due to presence of minerals unrelated to mineralization. These minerals can significantly alter the compositional features of the ores and suggest misleading conclusions. In Sardinia (Italy, western Mediterranean), Mn-oxide mineralizations occur and recently their origin has been discussed and identified (Sinisi et al. 2012). In this study the mineralogical and chemical compositions of the Sardinian sediment-hosted and volcanic-hosted Mn-ore are exhibit exploring the possibility that they can represent exploitable trace and REE mineralizations. High contents of metals characterize these Mn deposits. Besides some trace elements (Ni, Cr, Zn, Cu, As, Pb, and U) that commonly typify the Mn oxi-hydroxide ores, all rare earth elements showed high concentrations in the Sardinian deposits, comparable to those of the main actually exploited REE sinks. For this reason, a simple statistical data treatment (R-mode Factor Analysis) was performed on fifteen and nineteen samples of sediment-hosted and volcanic-hosted Mn ore respectively, in order to identify both the mineral phases trapping trace

Tire traces - discrimination and classification of pyrolysis-GC/MS profiles.

Science.gov (United States)

Gueissaz, Line; Massonnet, Geneviève

2013-07-10

Tire traces can be observed on several crime scenes as vehicles are often used by criminals. The tread abrasion on the road, while braking or skidding, leads to the production of small rubber particles which can be collected for comparison purposes. This research focused on the statistical comparison of Py-GC/MS profiles of tire traces and tire treads. The optimisation of the analytical method was carried out using experimental designs. The aim was to determine the best pyrolysis parameters regarding the repeatability of the results. Thus, the pyrolysis factor effect could also be calculated. The pyrolysis temperature was found to be five time more important than time. Finally, a pyrolysis at 650°C during 15s was selected. Ten tires of different manufacturers and models were used for this study. Several samples were collected on each tire, and several replicates were carried out to study the variability within each tire (intravariability). More than eighty compounds were integrated for each analysis and the variability study showed that more than 75% presented a relative standard deviation (RSD) below 5% for the ten tires, thus supporting a low intravariability. The variability between the ten tires (intervariability) presented higher values and the ten most variant compounds had a RSD value above 13%, supporting their high potential of discrimination between the tires tested. Principal Component Analysis (PCA) was able to fully discriminate the ten tires with the help of the first three principal components. The ten tires were finally used to perform braking tests on a racetrack with a vehicle equipped with an anti-lock braking system. The resulting tire traces were adequately collected using sheets of white gelatine. As for tires, the intravariability for the traces was found to be lower than the intervariability. Clustering methods were carried out and the Ward's method based on the squared Euclidean distance was able to correctly group all of the tire traces

Acute Effects of Moderate and Strenuous Running on Trace Element Distribution in the Brain, Liver, and Spleen of Trained Rats

Directory of Open Access Journals (Sweden)

Kıvanç Ergen

2013-03-01

Full Text Available Objective: Trace elements such as manganese (Mn, cobalt (Co and chromium (Cr play key roles in metabolic reactions and are important in many physiological enzymatic processes. In this study, we aimed to investigate the acute effects of moderate and strenuous running (treadmill exercise on the levels of Mn, Co and Cr in the brain, liver, and spleen of trained rats. Study Design: Animal experiment. Material and Methods: Twenty-one Wistar-Albino adult male rats were used in the study. Rats were grouped as control group (no mandated exercise; n=8, moderate exercise group (30 min exercise duration; n=7, and strenuous exercise group (60 min exercise duration; n=6. The levels of Mn, Co, and Cr in the frontal lobe, temporal lobe, brain stem, liver, and spleen were determined by atomic absorption spectrophotometer. Results: Cr levels in liver of rats increased in parallel to the time course of running supporting the exercise training effect on the action of insulin. Compared to the control group, the level of Co significantly decreased in the brain stem of rats in the moderate exercise group (p=0.009 and in the frontal lobe of rats in the strenuous exercise group (p=0.004. In the strenuous exercise group, an examination of the brain stem revealed that the level of Mn significantly decreased (p=0.001, and levels of Co and Cr were apparently depleted to the extent that these elements were no longer detectable. Conclusion: A notable finding is that during or after single bout strenuous exercise, levels of Co decreased in the spleen and particularly decreased in the brain stem of regularly trained rats. From this study, it can be inferred that sportsmen should aware trace element disturbances among the body parts or depletion of some trace elements after single bout of chronic strenuous running exercise.

Trace maps for arbitrary substitution sequences

International Nuclear Information System (INIS)

Avishai, Y.

1993-01-01

The discovery of quasi-crystals and their 1-dimensional modeling have led to a deep mathematical study of Schroedinger operators with an arbitrary deterministic potential sequence. In this work we address this problem and find trace maps for an arbitrary substitution sequence. our trace maps have lower dimensionality than those of Kolar and Nori, which make them quite attractive for actual applications. (authors)

A trace formula for the Iwahori-Hecke algebra

NARCIS (Netherlands)

Opdam, E.M.

1999-01-01

The Iwahori-Hecke algebra has a canonicaltrace $\\tau$. The trace is the evaluation at the identity element in the usual interpretation of the Iwahori-Hecke algebra as a sub-algebra of the convolution algebra of a p-adic semi-simple group. The Iwahori-Hecke algebra contains an important commutative

Trace elements and heavy metals in hair of stage III breast cancer patients.

Science.gov (United States)

Benderli Cihan, Yasemin; Sözen, Selim; Oztürk Yıldırım, Sema

2011-12-01

This prospective study was designed to compare the hair levels of 36 elements in 52 patients with stage III breast cancer to those of an equal number of healthy individuals. Principal component and cluster analysis were used for source of identification and apportionment of heavy metals and trace elements in these two groups. A higher average level of iron was found in samples from patients while controls had higher levels of calcium. Both patients and controls had elevated levels of tin, magnesium, zinc, and sodium. Almost all element values in cancer patients showed higher dispersion and asymmetry than in healthy controls. Between the two groups, there were statistically significant differences in the concentrations of silver, arsenic, gold, boron, barium, beryllium, calcium, cadmium, cerium, cobalt, cesium, gadolinium, manganese, nickel, lead, antimony, scandium, selenium, and zinc (p heavy metals and trace elements in the hair of breast cancer patients in comparison to healthy controls. These results could be of significance in the diagnosis of breast cancer.

Kinetics study on the reduction of trace plutonium (IV) by hydroxylamine in nitric acid media

International Nuclear Information System (INIS)

Fei Hongcheng; Luo Longjun

1998-01-01

Reaction kinetics of trace Pu(IV) (c(Pu(IV)≤10 -5 mol/L) with hydroxylamine in nitric acid solution is investigated. The effects of concentrations of Pu(IV), Pu(III), NO 3 - , H + and hydroxylamine on the reduction rate of trace Pu(IV) are examined. The rate law of reaction of trace Pu(IV) with hydroxylamine is obtained. The reduction rate of Pu(IV) increases obviously with increasing temperature and the apparent activation energy with k' 0 is equal to 147 kJ/mol. The reaction mechanism of trace Pu(IV) with hydroxylamine is discussed

The Effect of Smoking on the Serum Level of Some Trace Elements in Pregnant Women

International Nuclear Information System (INIS)

El-Ghetany, SH.M.; Ahmad, M.H.; Marei, E.S.; Ashrey, H. A.

2005-01-01

Maternal smoking during pregnancy is a cause of many adverse outcomes, not only during fetal life, but may also extend to childhood and even early adulthood. This study was designed to evaluate the effect of tobacco smoking on some trace elements on pregnant mothers who smoke and their newborns. The study was carried out on 150 pregnant women and their newborns; fifty smokers (group I), fifty passive smoker subjects (group II) and 50 non-smokers served as controls (group III). Their neonates were also categorized into three groups accordingly. Maternal urine cotinine was determined by radioimmunoassay as an indicator for the degree of influence of smoking, it confirmed a significant elevation among groups I and II. The serum levels of zinc (Zn), selenium (Se), copper (Cu), cadmium (Cd), manganese (Mn) and magnesium (Mg) were measured in the serum of pregnant mothers and the cord serum of their newborns by atomic absorption spectrophotometer. This study demonstrated significant lower concentrations of serum Zn and Se in group I and II and their newborns when compared to the control group and control newborns. Significant increases in serum Cd and Cu were observed in-group I and II and their neonates versus the controls. As regards Mn and Mg no significant difference was established between the three studied groups. Our results suggested that tobacco smoking had definite effect on some trace elements that absolutely had drawbacks on both pregnant mothers and their babies. Tobacco smoke contains many toxic, mutagenic and teratogenic substances. Several epidemiological studies illustrated that cigarette smoking among females during the reproductive period have a direct insult on the nutritional and health status of their babies (Jauniaux et al, 1999). Cigarette smoking

On the trace anomaly of a Weyl fermion

Energy Technology Data Exchange (ETDEWEB)

Bastianelli, Fiorenzo; Martelli, Riccardo [Dipartimento di Fisica e Astronomia, Università di Bologna,via Irnerio 46, I-40126 Bologna (Italy); INFN - Sezione di Bologna,via Irnerio 46, I-40126 Bologna (Italy)

2016-11-29

We calculate the trace anomaly of a Weyl fermion coupled to gravity by using Fujikawa’s method supplemented by a consistent regulator. The latter is constructed out of Pauli-Villars regulating fields. The motivation for presenting such a calculation stems from recent studies that suggest that the trace anomaly of chiral fermions in four dimensions might contain an imaginary part proportional to the Pontryagin density. We find that the trace anomaly of a Weyl fermion is given by half the trace anomaly of a Dirac fermion, so that no imaginary part proportional to the Pontryagin density is seen to arise.

A study on some trace elements in Chilean seafood

Energy Technology Data Exchange (ETDEWEB)

Gras, N; Munoz, L; Thieck, M; Hurtado, S [Comision Chilena de Energia Nuclear, Santiago (Chile). Lab. of Activation Analysis

1993-03-01

Levels of essential and toxic trace elements in six marine species greatly in demand in the international market (canned pink clams, razor clams, clams, king crab, sardines, and frozen albacore tuna fish) were studied. A special laboratory adequately equipped for handling and preparing biological materials, is described. The elements As, Br, Na, Se, Hg, Cr, Fe, Zn and Rb were determined by INAA, while copper and cadmium content were determined using RNAA. Significant differences were found on comparing the contents of some toxic elements in mollusk and other samples of marine food. Various certified reference materials (CRMs) of the IAEA, NIST and NIES were analyzed for quality assurance purposes. (author) 11 refs.; 1 fig.; 1 tab.

A study on some trace elements in Chilean seafood

International Nuclear Information System (INIS)

Gras, N.; Munoz, L.; Thieck, M.; Hurtado, S.

1993-01-01

Levels of essential and toxic trace elements in six marine species greatly in demand in the international market (canned pink clams, razor clams, clams, king crab, sardines, and frozen albacore tuna fish) were studied. A special laboratory adequately equipped for handling and preparing biological materials, is described. The elements As, Br, Na, Se, Hg, Cr, Fe, Zn and Rb were determined by INAA, while copper and cadmium content were determined using RNAA. Significant differences were found on comparing the contents of some toxic elements in mollusk and other samples of marine food. Various certified reference materials (CRMs) of the IAEA, NIST and NIES were analyzed for quality assurance purposes. (author) 11 refs.; 1 fig.; 1 tab

EpiContactTrace: an R-package for contact tracing during livestock disease outbreaks and for risk-based surveillance.

Science.gov (United States)

Nöremark, Maria; Widgren, Stefan

2014-03-17

During outbreak of livestock diseases, contact tracing can be an important part of disease control. Animal movements can also be of relevance for risk-based surveillance and sampling, i.e. both when assessing consequences of introduction or likelihood of introduction. In many countries, animal movement data are collected with one of the major objectives to enable contact tracing. However, often an analytical step is needed to retrieve appropriate information for contact tracing or surveillance. In this study, an open source tool was developed to structure livestock movement data to facilitate contact-tracing in real time during disease outbreaks and for input in risk-based surveillance and sampling. The tool, EpiContactTrace, was written in the R-language and uses the network parameters in-degree, out-degree, ingoing contact chain and outgoing contact chain (also called infection chain), which are relevant for forward and backward tracing respectively. The time-frames for backward and forward tracing can be specified independently and search can be done on one farm at a time or for all farms within the dataset. Different outputs are available; datasets with network measures, contacts visualised in a map and automatically generated reports for each farm either in HTML or PDF-format intended for the end-users, i.e. the veterinary authorities, regional disease control officers and field-veterinarians. EpiContactTrace is available as an R-package at the R-project website (http://cran.r-project.org/web/packages/EpiContactTrace/). We believe this tool can help in disease control since it rapidly can structure essential contact information from large datasets. The reproducible reports make this tool robust and independent of manual compilation of data. The open source makes it accessible and easily adaptable for different needs.

Trace element inhibition of phytase activity.

Science.gov (United States)

Santos, T; Connolly, C; Murphy, R

2015-02-01

Nowadays, 70 % of global monogastric feeds contains an exogenous phytase. Phytase supplementation has enabled a more efficient utilisation of phytate phosphorous (P) and reduction of P pollution. Trace minerals, such as iron (Fe), zinc (Zn), copper (Cu) and manganese (Mn) are essential for maintaining health and immunity as well as being involved in animal growth, production and reproduction. Exogenous sources of phytase and trace elements are regularly supplemented to monogastric diets and usually combined in a premix. However, the possibility for negative interaction between individual components within the premix is high and is often overlooked. Therefore, this initial study focused on assessing the potential in vitro interaction between inorganic and organic chelated sources of Fe, Zn, Cu and Mn with three commercially available phytase preparations. Additionally, this study has investigated if the degree of enzyme inhibition was dependent of the type of chelated sources. A highly significant relationship between phytase inhibition, trace mineral type as well as mineral source and concentration, p phytases for Fe and Zn, as well as for Cu with E. coli and Aspergillus niger phytases. Different chelate trace mineral sources demonstrated diversifying abilities to inhibit exogenous phytase activity.

Can echoic memory store two traces simultaneously? A study of event-related brain potentials.

Science.gov (United States)

Winkler, I; Paavilainen, P; Näätänen, R

1992-05-01

The mismatch negativity, a component of the event-related brain potential elicited by infrequent deviants in sequences of auditory stimuli, is presumably generated by an automatic mismatch process in a mechanism that compares the current stimulus to the trace of the previous one. The present study addressed the possible simultaneous existence of two such traces. Two equiprobable (45% each) frequent stimuli ("standards"), one of 600 Hz and the other of 700 Hz, were presented together with an infrequent (10%), "deviant" stimulus which was of different frequency in different blocks. These deviants elicited a mismatch negativity, though a smaller one than that obtained in corresponding blocks with only one standard stimulus. Two aspects of the present results from the blocks with two standard stimuli implicate two parallel stimulus traces in these blocks: 1) deviants elicited a mismatch negativity (MMN) of approximately the same amplitude when preceded by sequences of four identical standards as when preceded by sequences of four stimuli containing both standards; 2) in contrast to the one-standard condition, the magnitude of stimulus deviance did not affect the MMN component elicited by the different deviants.

Effect of zinc from zinc sulfate on trace mineral concentrations of milk in Varamini ewes

NARCIS (Netherlands)

Zali, A.; Ganjkhanlou, M.

2009-01-01

This study was conducted to evaluate the effect of feeding supplemental zinc (zinc sulfate) in different levels (15, 30, or 45 mg/kg) on trace mineral concentrations in milk of ewes. Thirty lactating Varaminni ewes were assigned to three experimental groups according to their live body weights, milk

Neutron transport study based on assembly modular ray tracing MOC method

International Nuclear Information System (INIS)

Tian Chao; Zheng Youqi; Li Yunzhao; Li Shuo; Chai Xiaoming

2015-01-01

It is difficulty for the MOC method based on Cell Modular Ray Tracing to deal with the irregular geometry such as the water gap between the PWR lattices. Hence, the neutron transport code NECP-Medlar based on Assembly Modular Ray Tracing is developed. CMFD method is used to accelerate the transport calculation. The numerical results of the 2D C5G7 benchmark and typical PWR lattice prove that NECP-Medlar has an excellent performance in terms of accuracy and efficiency. Besides, NECP-Medlar can describe clearly the flux distribution of the lattice with water gap. (authors)

Terrestrial sedimentary pyrites as a potential source of trace metal release to groundwater – A case study from the Emsland, Germany

International Nuclear Information System (INIS)

Houben, Georg J.; Sitnikova, Maria A.; Post, Vincent E.A.

2017-01-01

Pyrite is a common minor constituent of terrestrial freshwater sediments and a sink for trace elements. Different amounts and morphological types (framboids and euhedral crystals) of sedimentary pyrites were found in the heavy mineral fraction of cores obtained from several drillholes located in the Emsland region, NW Germany. Their trace element contents were investigated to assess their potential for groundwater contamination after oxidation, e.g. induced by dewatering or autotrophic denitrification. Nickel, arsenic and cadmium were found in significant concentrations in pyrite. Geochemical modeling showed that elevated trace metal concentrations in groundwater, potentially exceeding drinking water standards, should preferentially occur in a less than 1 m thick zone situated around the depth of the redoxcline, where nitrate is reduced by pyrite. This was confirmed by depth-specific groundwater sampling in the Emsland and by previously published studies. The absolute concentration of released trace metals depends on their content in the pyrite but also strongly on the nitrate load of groundwater. - Highlights: • Pyrite from heavy mineral fraction of aquifer sediment analyzed for trace metal content. • Pyrites contain significant concentration of trace metals, such as nickel, arsenic, cadmium. • Trace elements are released by autotrophic denitrification. • Reactive transport model predicts small zone of trace element accumulation. • Release of trace elements strongly dependent on nitrate content of groundwater.

Prediction of adiabatic bubbly flows in TRACE using the interfacial area transport equation

International Nuclear Information System (INIS)

Talley, J.; Worosz, T.; Kim, S.; Mahaffy, J.; Bajorek, S.; Tien, K.

2011-01-01

conventional code is predominantly determined by the pressure. It is found that TRACE with the IATE significantly improves prediction results, yielding a ±10.3% difference with the data. In addition, the IATE always predicts the correct axial trend of a i and can also predict non-linear axial development that reflects the bubble interactions along the flow. Additional studies are being performed to implement a two-group IATE to further expand the capability of the code. (author)

Geochemical studies of Guarani ethnic groups pottery with XRF

International Nuclear Information System (INIS)

Facetti-Masulli, J.F.; Romero de Gonzalez, V.; Zulma de Diaz; Kump, P.

2010-01-01

Artefacts of pottery belonging to the Guarani ethnic group were investigated by XRF techniques. The Tupi-Guarani, is one of the three main representatives of the Neolithic culture in the Amazonian scope. Such an ethnic group dispersed towards the South; in the Paraguayan area between the Paraguay and the Parana Rivers several Guarani ethnic movements by both rivers and their tributaries are perceived. The lithology and ceramics typology have contributed to support that perception. The archaeological findings help to clarify prehistoric cultural aspects and dispersal areas. In that context, the knowledge of the chemical composition of the found ceramic devices, in particular of the rare earth elements (REE) and other refractory ones provide information on this dispersion and its expansion. Selected trace elements (Rb, Sr, Y, Zr, Nb, Ba, La, Ce, and Nd) were determined in samples from thirteen archaeological sites with XRF using an Am-241 source. Their spidergrams have allowed identifying four different sets of samples according to their areas of provenance. (author)

Comparison of matrix method and ray tracing in the study of complex optical systems

Science.gov (United States)

Anterrieu, Eric; Perez, Jose-Philippe

2000-06-01

In the context of the classical study of optical systems within the geometrical Gauss approximation, the cardinal elements are efficiently obtained with the aid of the transfer matrix between the input and output planes of the system. In order to take into account the geometrical aberrations, a ray tracing approach, using the Snell- Descartes laws, has been implemented in an interactive software. Both methods are applied for measuring the correction to be done to a human eye suffering from ametropia. This software may be used by optometrists and ophthalmologists for solving the problems encountered when considering this pathology. The ray tracing approach gives a significant improvement and could be very helpful for a better understanding of an eventual surgical act.

AXAF FITS standard for ray trace interchange

Science.gov (United States)

Hsieh, Paul F.

1993-07-01

A standard data format for the archival and transport of x-ray events generated by ray trace models is described. Upon review and acceptance by the Advanced X-ray Astrophysics Facility (AXAF) Software Systems Working Group (SSWG), this standard shall become the official AXAF data format for ray trace events. The Flexible Image Transport System (FITS) is well suited for the purposes of the standard and was selected to be the basis of the standard. FITS is both flexible and efficient and is also widely used within the astronomical community for storage and transfer of data. In addition, software to read and write FITS format files are widely available. In selecting quantities to be included within the ray trace standard, the AXAF Mission Support team, Science Instruments team, and the other contractor teams were surveyed. From the results of this survey, the following requirements were established: (1) for the scientific needs, each photon should have associated with it: position, direction, energy, and statistical weight; the standard must also accommodate path length (relative phase), and polarization. (2) a unique photon identifier is necessary for bookkeeping purposes; (3) a log of individuals, organizations, and software packages that have modified the data must be maintained in order to create an audit trail; (4) a mechanism for extensions to the basic kernel should be provided; and (5) the ray trace standard should integrate with future AXAF data product standards.

An evaluation of trace element release associated with acid mine drainage

International Nuclear Information System (INIS)

Sullivan, P.J.; Yelton, J.L.

1988-01-01

The determination of trace element release from geologic materials, such as oil shale and coal overburden, is important for proper solid waste management planning. The objective of this study was to determine a correlation between release using the following methods: (1) sequential selective dissolution for determining trace element residencies, (2) toxicity characteristic leaching procedure (TCLP), and (3) humidity cell weathering study simulating maximum trace element release. Two eastern oil shales were used, a New Albany shale that contains 4.6 percent pyrite, and a Chattanooga shale that contains 1.5 percent pyrite. Each shale was analyzed for elemental concentrations by soluble, adsorbed, organic, carbonate, and sulfide phases. The results of the results of the selective dissolution studies show that each trace element has a unique distribution between the various phases. Thus, it is possible to predict trace element release based on trace element residency. The TCLP results show that this method is suitable for assessing soluble trace element release but does not realistically assess potential hazards. The results of the humidity cell studies do demonstrate a more reasonable method for predicting trace element release and potential water quality hazards. The humidity cell methods, however, require months to obtain the required data with a large number of analytical measurements. When the selective dissolution data are compared to the trace element concentrations in the TCLP and humidity cell leachates, it is shown that leachate concentrations are predicted by the selective dissolution data. Therefore, selective dissolution may represent a rapid method to assess trace element release associated with acid mine drainage

Instrumental trace element analysis of California market milk

International Nuclear Information System (INIS)

Ragaini, R.C.; Langhorst, A.L.; Ralston, H.R.; Heft, R.

1975-01-01

Trace element analysis for 15 elements (Zn, Na, Br, Rb, Sr, Mg, Al, Ca, Cl, I, K, Fe, Co, Se, Cs) was carried out on 32 samples of California market milk and 6 samples of Colorado milk in a pilot study of toxic and nutrient trace elements in the soil-forage-cow-milk food chain. The techniques of instrumental neutron activation analysis and x-ray fluorescence analysis are described. Sample collection, preparation, analysis, and data reduction procedures are discussed. The mean values and variations of trace element concentrations in milk are compared to data from other studies. (U.S.)

A comparative study of pH modulation and trace elements of various fruit juices on enamel erosion: An in vitro study

Directory of Open Access Journals (Sweden)

S.V.S.G Nirmala

2011-01-01

Full Text Available Fruit juices are popular worldwide with children of all ages as they are sweet and perceived to be healthful. This in vitro study was sought to measure pH of 10 different fruit juices, to find out possible erosive effects on human dental enamel of 40 extracted sound premolars and also to measure fluoride and trace elements of these juices. The estimation of pH of fruit juices was done by using Systronic upH 362 pH meter. The erosive effects of fruit juices were tested by using polarized light microscope. Orion electrode was used to measure fluoride. The trace elements were estimated by using Atomic Absorption Spectrophotometer No. 6501F. The pH values in different juices were observed at different levels, and pH values of these juices were more acidic than baseline after 24 hours. As the time increased, the erosion effect became more in pineapple; grape and sugarcane juices, and they had more cariogenic trace elements like selenium, iron and manganese. So, these juices were found to be cariogenic. To conclude, orange, mousambi, mango, pomegranate, apple, chikku and watermelon juices had no erosive effect on the human enamel, with the presence of highest amount of trace elements like fluoride and phosphorous which are considered as strongly cariostatic.

Trace methane oxidation studied in several Euryarchaeota under diverse conditions

Directory of Open Access Journals (Sweden)

James J. Moran

2005-01-01

Full Text Available We used 13C-labeled methane to document the extent of trace methane oxidation by Archaeoglobus fulgidus, Archaeoglobus lithotrophicus, Archaeoglobus profundus, Methanobacterium thermoautotrophicum, Methanosarcina barkeri and Methanosarcina acetivorans. The results indicate trace methane oxidation during growth varied among different species and among methanogen cultures grown on different substrates. The extent of trace methane oxidation by Mb. thermoautotrophicum (0.05 ± 0.04%, ± 2 standard deviations of the methane produced during growth was less than that by M. barkeri (0.15 ± 0.04%, grown under similar conditions with H2 and CO2. Methanosarcina acetivorans oxidized more methane during growth on trimethylamine (0.36 ± 0.05% than during growth on methanol (0.07 ± 0.03%. This may indicate that, in M. acetivorans, either a methyltransferase related to growth on trimethylamine plays a role in methane oxidation, or that methanol is an intermediate of methane oxidation. Addition of possible electron acceptors (O2, NO3–, SO22–, SO32– or H2 to the headspace did not substantially enhance or diminish methane oxidation in M. acetivorans cultures. Separate growth experiments with FAD and NAD+ showed that inclusion of these electron carriers also did not enhance methane oxidation. Our results suggest trace methane oxidized during methanogenesis cannot be coupled to the reduction of these electron acceptors in pure cultures, and that the mechanism by which methane is oxidized in methanogens is independent of H2 concentration. In contrast to the methanogens, species of the sulfate-reducing genus Archaeoglobus did not significantly oxidize methane during growth (oxidizing 0.003 ± 0.01% of the methane provided to A. fulgidus, 0.002 ± 0.009% to A. lithotrophicus and 0.003 ± 0.02% to A. profundus. Lack of observable methane oxidation in the three Archaeoglobus species examined may indicate that methyl-coenzyme M reductase, which is not present in

A Rotor Tip Vortex Tracing Algorithm for Image Post-Processing

Science.gov (United States)

Overmeyer, Austin D.

2015-01-01

A neurite tracing algorithm, originally developed for medical image processing, was used to trace the location of the rotor tip vortex in density gradient flow visualization images. The tracing algorithm was applied to several representative test images to form case studies. The accuracy of the tracing algorithm was compared to two current methods including a manual point and click method and a cross-correlation template method. It is shown that the neurite tracing algorithm can reduce the post-processing time to trace the vortex by a factor of 10 to 15 without compromising the accuracy of the tip vortex location compared to other methods presented in literature.

Phase and group velocity tracing analysis of projected wave packet motion along oblique radar beams – qualitative analysis of QP echoes

Directory of Open Access Journals (Sweden)

F. S. Kuo

2007-02-01

Full Text Available The wave packets of atmospheric gravity waves were numerically generated, with a given characteristic wave period, horizontal wave length and projection mean wind along the horizontal wave vector. Their projection phase and group velocities along the oblique radar beam (vpr and vgr, with different zenith angle θ and azimuth angle φ, were analyzed by the method of phase- and group-velocity tracing. The results were consistent with the theoretical calculations derived by the dispersion relation, reconfirming the accuracy of the method of analysis. The RTI plot of the numerical wave packets were similar to the striation patterns of the QP echoes from the FAI irregularity region. We propose that the striation range rate of the QP echo is equal to the radial phase velocity vpr, and the slope of the energy line across the neighboring striations is equal to the radial group velocity vgr of the wave packet; the horizontal distance between two neighboring striations is equal to the characteristic wave period τ. Then, one can inversely calculate all the properties of the gravity wave responsible for the appearance of the QP echoes. We found that the possibility of some QP echoes being generated by the gravity waves originated from lower altitudes cannot be ruled out.

Bridging the interval: theory and neurobiology of trace conditioning.

Science.gov (United States)

Raybuck, Jonathan D; Lattal, K Matthew

2014-01-01

An early finding in the behavioral analysis of learning was that conditioned responding weakens as the conditioned stimulus (CS) and unconditioned stimulus (US) are separated in time. This "trace" conditioning effect has been the focus of years of research in associative learning. Theoretical accounts of trace conditioning have focused on mechanisms that allow associative learning to occur across long intervals between the CS and US. These accounts have emphasized degraded contingency effects, timing mechanisms, and inhibitory learning. More recently, study of the neurobiology of trace conditioning has shown that even a short interval between the CS and US alters the circuitry recruited for learning. Here, we review some of the theoretical and neurobiological mechanisms underlying trace conditioning with an emphasis on recent studies of trace fear conditioning. Findings across many studies have implications not just for how we think about time and conditioning, but also for how we conceptualize fear conditioning in general, suggesting that circuitry beyond the usual suspects needs to be incorporated into current thinking about fear, learning, and anxiety. Copyright © 2013 Elsevier B.V. All rights reserved.

Inorganic and organic trace mineral supplementation in weanling pig diets

Directory of Open Access Journals (Sweden)

MARIA C. THOMAZ

2015-06-01

Full Text Available A study was conducted to evaluate the effects of dietary inorganic and organic trace minerals in two levels of supplementation regarding performance, diarrhea occurrence, hematological parameters, fecal mineral excretion and mineral retention in metacarpals and liver of weanling pigs. Seventy piglets weaned at 21 days of age with an average initial body weight of 6.70 ± 0.38 kg were allotted in five treatments: control diet (no added trace mineral premix; 50% ITMP (control diet with inorganic trace mineral premix supplying only 50% of trace mineral requirements; 50% OTMP (control diet with organic trace mineral premix supplying only 50% of trace mineral requirements; 100% ITMP (control diet with inorganic trace mineral premix supplying 100% of trace mineral requirements; and 100% OTMP (control diet with organic trace mineral premix supplying 100% of trace mineral requirements. Feed intake and daily weight gain were not affected by treatments, however, piglets supplemented by trace minerals presented better gain:feed ratio. No differences were observed at calcium, phosphorus, potassium, magnesium, sodium and sulfur excreted in feces per kilogram of feed intake. Treatments did not affect calcium, phosphorus, magnesium, sulfur and iron content in metacarpals. Trace mineral supplementation, regardless of level and source, improved the performance of piglets.

Study of trace metals in evaporites of Sergipe, Brazil

International Nuclear Information System (INIS)

Andrade, L.L.

1982-01-01

Heavy metals and others which form strong complexes must be present in the brine feed of electrolytic cells only at very low levels. Their occurrence in quantities above the established levels has a deleterious effect on the membranes of the cells and will produce interference on voltage, current efficiency and other factors. The waste resulting from decantation of the brine causes serious environmental problems. Thirty brine samples from different sites, provided by Petrobras Mineracao S.A. (Brazil) were studied. The sample preparation method and the analytical results obtained from semiquantitative determination of trace metals by optical emission spectrography are described. The toxicity of certain metals, their effects on the environment and on electrolytic cell membranes are also discussed. (Author) [pt

The development and assessment of TRACE/PARCS model for Lungmen ABWR

Energy Technology Data Exchange (ETDEWEB)

Lin, Hao-Tzu, E-mail: htlin@iner.gov.tw [Institute of Nuclear Energy Research, Atomic Energy Council, R.O.C., 1000, Wenhua Road, Jiaan Village, Longtan Township, Taoyuan County, 32546, Taiwan, ROC (China); Wang, Jong-Rong, E-mail: jrwang@iner.gov.tw [Institute of Nuclear Energy Research, Atomic Energy Council, R.O.C., 1000, Wenhua Road, Jiaan Village, Longtan Township, Taoyuan County, 32546, Taiwan, ROC (China); Chen, Hsiung-Chih, E-mail: km8385@gmail.com [Institute of Nuclear Engineering and Science, National Tsing Hua University, No. 101, Section 2, Kuang Fu Road, HsinChu 30013, Taiwan, ROC (China); Shih, Chunkuan, E-mail: ckshih@ess.nthu.edu.tw [Institute of Nuclear Engineering and Science, National Tsing Hua University, No. 101, Section 2, Kuang Fu Road, HsinChu 30013, Taiwan, ROC (China)

2014-07-01

Highlights: • The development of a TRACE/PARCS model of Lungmen (ABWR). • Thermal-hydraulics model of TRACE is coupling with 3-D neutronics model of PARCS. • The 3-D geometry vessel component of TRACE is used in this study. • The parameters responses of Lungmen TRACE/PARCS model are consistent with FSAR data. - Abstract: This study consists of two steps. The first step is the development of a TRACE (TRAC/RELAP Advanced Computational Engine)/PARCS (Purdue Advanced Reactor Core Simulator) model of Lungmen nuclear power plant (NPP) which includes the vessel, reactor internal pumps (RIPs), main steam lines, and important control systems (such as the feedwater control system, steam bypass and pressure control system, and recirculation flow control system), etc. Key parameters were identified to refine the TRACE/PARCS model further in the frame of a steady state analysis. The second step is the performance of Lungmen NPP TRACE/PARCS model transient analyses. The transient data of Final Safety Analysis Report (FSAR) chapter 15th were used to compare with the results of Lungmen NPP TRACE/PARCS model. The trends of TRACE/PARCS analysis results were consistent with the FSAR data. It indicated that there was a respectable accuracy in the Lungmen NPP TRACE/PARCS model and it also depicted that the Lungmen NPP TRACE/PARCS model was satisfying for the purpose of Lungmen NPP safety analyses.

Poisson traces, D-modules, and symplectic resolutions.

Science.gov (United States)

Etingof, Pavel; Schedler, Travis

2018-01-01

We survey the theory of Poisson traces (or zeroth Poisson homology) developed by the authors in a series of recent papers. The goal is to understand this subtle invariant of (singular) Poisson varieties, conditions for it to be finite-dimensional, its relationship to the geometry and topology of symplectic resolutions, and its applications to quantizations. The main technique is the study of a canonical D-module on the variety. In the case the variety has finitely many symplectic leaves (such as for symplectic singularities and Hamiltonian reductions of symplectic vector spaces by reductive groups), the D-module is holonomic, and hence, the space of Poisson traces is finite-dimensional. As an application, there are finitely many irreducible finite-dimensional representations of every quantization of the variety. Conjecturally, the D-module is the pushforward of the canonical D-module under every symplectic resolution of singularities, which implies that the space of Poisson traces is dual to the top cohomology of the resolution. We explain many examples where the conjecture is proved, such as symmetric powers of du Val singularities and symplectic surfaces and Slodowy slices in the nilpotent cone of a semisimple Lie algebra. We compute the D-module in the case of surfaces with isolated singularities and show it is not always semisimple. We also explain generalizations to arbitrary Lie algebras of vector fields, connections to the Bernstein-Sato polynomial, relations to two-variable special polynomials such as Kostka polynomials and Tutte polynomials, and a conjectural relationship with deformations of symplectic resolutions. In the appendix we give a brief recollection of the theory of D-modules on singular varieties that we require.

Poisson traces, D-modules, and symplectic resolutions

Science.gov (United States)

Etingof, Pavel; Schedler, Travis

2018-03-01

We survey the theory of Poisson traces (or zeroth Poisson homology) developed by the authors in a series of recent papers. The goal is to understand this subtle invariant of (singular) Poisson varieties, conditions for it to be finite-dimensional, its relationship to the geometry and topology of symplectic resolutions, and its applications to quantizations. The main technique is the study of a canonical D-module on the variety. In the case the variety has finitely many symplectic leaves (such as for symplectic singularities and Hamiltonian reductions of symplectic vector spaces by reductive groups), the D-module is holonomic, and hence, the space of Poisson traces is finite-dimensional. As an application, there are finitely many irreducible finite-dimensional representations of every quantization of the variety. Conjecturally, the D-module is the pushforward of the canonical D-module under every symplectic resolution of singularities, which implies that the space of Poisson traces is dual to the top cohomology of the resolution. We explain many examples where the conjecture is proved, such as symmetric powers of du Val singularities and symplectic surfaces and Slodowy slices in the nilpotent cone of a semisimple Lie algebra. We compute the D-module in the case of surfaces with isolated singularities and show it is not always semisimple. We also explain generalizations to arbitrary Lie algebras of vector fields, connections to the Bernstein-Sato polynomial, relations to two-variable special polynomials such as Kostka polynomials and Tutte polynomials, and a conjectural relationship with deformations of symplectic resolutions. In the appendix we give a brief recollection of the theory of D-modules on singular varieties that we require.

Asian Heritage in Roberta Carreri's artistic autobiography, Traces in the Snow

DEFF Research Database (Denmark)

Kuhlmann, Annelis

2014-01-01

The intercultural relation between Asian performing traditions and Western avant-garde group theatres has left traces in both training and aesthetics. Especially in performative professional autobiographies the body narrative reveals a presence that contains historiographical and artistic questions...... on the ephemerality of the performance. At Odin Teatret, almost every artist has several work demonstrations that transform an image of the professional autobiography of the actor. With focus on Roberta Carreri’s work demonstration Traces in the Snow this paper discusses the challenges of research methods concerning...

Preconcentration and Speciation of Trace Elements and Trace-Element Analogues of Radionuclides by Neutron Activation Analysis

International Nuclear Information System (INIS)

Chatt, A.

1999-01-01

We have developed a number of preconcentration neutron activation analysis (PNAA) methods in our laboratory for the determination of trace elements in a variety of complex sample matrices. We developed a number of cocrystallization and coprecipitation methods for the determination of trace elements in water samples. We developed several methods for the determination of I in foods and diets. We have developed a number of PNAA methods in our laboratory We determined As and Sb in geological materials and natural waters by coprecipitation with Se and Au in silicate rocks and ores by coprecipitation with Te followed by NAA. We developed an indirect NAA method for the determination of B in leachates of borosilicate glass. We have been interested in studying the speciation of Am, Tc, and Np in simulated vitrified groundwater leachates of high-level wastes under oxid and anoxic conditions using a number of techniques. We then used PNAA methods to study speciation of trace-element analogues of radionuclides. We have been able to apply biochemical techniques and NAA for the separation, preconcentration, and characterization of metalloprotein and protein-bound trace-element species in subcellular fractions of bovine kidneys. Lately, we have concentrated our efforts to develop chemical and biochemical methods in conjunction with NAA, NMR, and MS for the separation and identification of extractable organohalogens (EOX) in tissues of beluga whales, cod, and northern pink shrimp

Olfactory memory traces in Drosophila.

Science.gov (United States)

Berry, Jacob; Krause, William C; Davis, Ronald L

2008-01-01

In Drosophila, the fruit fly, coincident exposure to an odor and an aversive electric shock can produce robust behavioral memory. This behavioral memory is thought to be regulated by cellular memory traces within the central nervous system of the fly. These molecular, physiological, or structural changes in neurons, induced by pairing odor and shock, regulate behavior by altering the neurons' response to the learned environment. Recently, novel in vivo functional imaging techniques have allowed researchers to observe cellular memory traces in intact animals. These investigations have revealed interesting temporal and spatial dynamics of cellular memory traces. First, a short-term cellular memory trace was discovered that exists in the antennal lobe, an early site of olfactory processing. This trace represents the recruitment of new synaptic activity into the odor representation and forms for only a short period of time just after training. Second, an intermediate-term cellular memory trace was found in the dorsal paired medial neuron, a neuron thought to play a role in stabilizing olfactory memories. Finally, a long-term protein synthesis-dependent cellular memory trace was discovered in the mushroom bodies, a structure long implicated in olfactory learning and memory. Therefore, it appears that aversive olfactory associations are encoded by multiple cellular memory traces that occur in different regions of the brain with different temporal domains.

Dietary intakes of essential trace elements. Results from total diet studies supported by the IAEA

International Nuclear Information System (INIS)

Parr, R.M.; Iyengar, G.V.; Aras, N.K.

2006-01-01

The International Atomic Energy Agency (IAEA) has, for many years, supported research on human dietary intakes of trace elements taking advantage, for analysis, of the possibilities offered by nuclear techniques, particularly neutron activation analysis (NAA). This paper summarizes the results obtained from studies in more than 20 countries in which special emphasis was placed on the application of reliable methodologies (written protocols, special equipment, analytical quality control, etc.). Considerable variation was observed among dietary intakes of essential minor and trace elements though most elements showed a pattern of adequate nutrition in most countries. However, for some elements such as calcium, iodine, iron and zinc, the intakes in many countries were lower than the dietary requirements. (author)

Determination of trace elements in kidneys, livers and brains of rats with sealer implants by ICP-MS

International Nuclear Information System (INIS)

Simsek, Neslihan; Akinci, Levent; Alan, Hilal; Gecör, Orhan; Özan, Ülkü

2017-01-01

Following root canal treatment, sealers may contact periapical tissue. The purpose of this study was to evaluate the systemic toxic effects of epoxy resin-based sealers (AH Plus and Obtuseal). Inductively coupled plasma-mass spectrometry (ICP-MS) was used to measure levels of trace elements (beryllium, magnesium, aluminium, calcium, chromium, arsenic and lead) in the brain, kidney and liver of rats. Twenty sterilized polyethylene tubes were then filled with AH Plus and Obtuseal and implanted into the dorsal subcutaneous tissue of 10 rats; three unoperated animals were used as a control group. After 45 days, the rats were sacrificed by cervical dislocation following anaesthesia, and brains, kidneys and livers were removed from all experimental animals. ICP-MS analysis was used to determine levels of trace elements. Data were analysed using Kruskal– Wallis and Connover post hoc tests. No significant differences were found in aluminium and calcium levels, but brains, kidneys and livers showed significantly higher amounts of magnesium and chromium than the corresponding controls. In the kidney and liver samples, arsenic levels were found to be higher than in the control group. Lead was detected at higher levels only in liver samples from the AH Plus group. Beryllium was not detected in any organ. It was concluded that AH Plus and Obtuseal release minimal quantities of trace elements when in contact with subcutaneous tissue, and further studies are needed to understand the systemic effects of these materials

Radioisotope studies of some effects and interactions of trace contaminants

International Nuclear Information System (INIS)

1976-01-01

The coordinated programme of ''isotopic tracer-aided studies of the biological side-effects of foreign chemical residues in food and agriculture'', initiated in 1973, had involved the participation of 12 scientists from 10 countries. Pesticide residues, toxic metals, atmospheric sulphur dioxide were studied, and the use of radiotracer techniques as monitoring tools for existing contaminant levels or for their biological effects. The programme had been successful in the development and application of selected labelled substrate techniques. Specific aspects studied were the effects of environmental contaminants at the molecular level of the cell nucleus, the development and significance of radioimmunoassay procedure for trace contaminants, action and joint action of toxic elements, and the radiometric analysis of cholinesterase as an index of exposure to organophosphorus and carbamate pesticides. Ten papers were presented and 12 coordinated investigations discussed. A number of recommendations were made

GALAXIES IN X-RAY GROUPS. II. A WEAK LENSING STUDY OF HALO CENTERING

Energy Technology Data Exchange (ETDEWEB)

George, Matthew R.; Ma, Chung-Pei [Department of Astronomy, University of California, Berkeley, CA 94720 (United States); Leauthaud, Alexie; Bundy, Kevin [Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU, WPI), Todai Institutes for Advanced Study, University of Tokyo, Kashiwa 277-8583 (Japan); Finoguenov, Alexis [Max-Planck-Institut fuer Extraterrestrische Physik, Giessenbachstrasse, D-85748 Garching (Germany); Rykoff, Eli S. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Tinker, Jeremy L. [Center for Cosmology and Particle Physics, Department of Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); Wechsler, Risa H. [Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Massey, Richard [Department of Physics, University of Durham, South Road, Durham DH1 3LE (United Kingdom); Mei, Simona, E-mail: mgeorge@astro.berkeley.edu [Bureau des Galaxies, Etoiles, Physique, Instrumentation (GEPI), University of Paris Denis Diderot, F-75205 Paris Cedex 13 (France)

2012-09-20

Locating the centers of dark matter halos is critical for understanding the mass profiles of halos, as well as the formation and evolution of the massive galaxies that they host. The task is observationally challenging because we cannot observe halos directly, and tracers such as bright galaxies or X-ray emission from hot plasma are imperfect. In this paper, we quantify the consequences of miscentering on the weak lensing signal from a sample of 129 X-ray-selected galaxy groups in the COSMOS field with redshifts 0 < z < 1 and halo masses in the range 10{sup 13}-10{sup 14} M{sub Sun }. By measuring the stacked lensing signal around eight different candidate centers (such as the brightest member galaxy, the mean position of all member galaxies, or the X-ray centroid), we determine which candidates best trace the center of mass in halos. In this sample of groups, we find that massive galaxies near the X-ray centroids trace the center of mass to {approx}< 75 kpc, while the X-ray position and centroids based on the mean position of member galaxies have larger offsets primarily due to the statistical uncertainties in their positions (typically {approx}50-150 kpc). Approximately 30% of groups in our sample have ambiguous centers with multiple bright or massive galaxies, and some of these groups show disturbed mass profiles that are not well fit by standard models, suggesting that they are merging systems. We find that halo mass estimates from stacked weak lensing can be biased low by 5%-30% if inaccurate centers are used and the issue of miscentering is not addressed.

Study Groups in Denmark

DEFF Research Database (Denmark)

Hjorth, Poul G.

2007-01-01

Since 1998 European Study Groups have been held in Denmark, and Danish companies from LEGO and NOVO to very small high-tech firms have participated. I briefly describe the history, the organisation and the format of the Danish Study Groups, and highlight a few problem solutions.......Since 1998 European Study Groups have been held in Denmark, and Danish companies from LEGO and NOVO to very small high-tech firms have participated. I briefly describe the history, the organisation and the format of the Danish Study Groups, and highlight a few problem solutions....

Serum Trace Element Presentation in Female Wistar Rats ...

African Journals Online (AJOL)

Serum Trace Element Presentation in Female Wistar Rats administered with Paracetamol & Paracetamol/Methionine. AA Iyanda, FAA Adeniyi. Abstract. A number of therapeutic agents are known to alter serum trace element levels with dangerous consequences. An earlier study had demonstrated significant alteration in the ...

Aboriginal Consumption of Estuarine Food Resources and Potential Implications for Health through Trace Metal Exposure; A Study in Gumbaynggirr Country, Australia.

Science.gov (United States)

Russell, Shaina; Sullivan, Caroline A; Reichelt-Brushett, Amanda J

2015-01-01

Fishing and resource use continues to be an essential aspect of life for many Aboriginal communities throughout Australia. It is important for dietary sustenance, and also retains deep social, cultural and economic significance, playing a fundamental role in maintaining group cohesion, transferring cultural knowledge and affirming Indigenous identities. We surveyed approximately 20% of the Gumbaynggirr Aboriginal community of Nambucca Heads, New South Wales, Australia. This paper explores Gumbaynggirr Connection to Country and engagement in cultural practice. It quantifies fishing efforts and consumption of seafood within the community. We found 95% of the sample group fish, with the highest rate of fishing being 2-3 times a week (27%). Furthermore, 98% of participants eat seafood weekly or more frequently, up to more than once a day (24%). Survey results revealed that Myxus elongatus (Sand mullet) and naturally recruited Saccostrea glomerata (Sydney rock oysters) continue to be important wild resources to the Gumbaynggirr community. Trace metals were measured in M. elongatus and S. glomerata samples collected by community participants in this study. Maximum levels prescribed in the Australia New Zealand Food Standards Code were not exceeded in the edible tissue for either species, however both species exceeded the generally expected levels for zinc and copper and S. glomerata samples exceeded the generally expected level for selenium. Furthermore the average dietary exposure to trace metals from consuming seafood was calculated for the surveyed population. Trace metal intake was then compared to the provisional tolerable weekly intake prescribed by the Joint Expert Committee on Food Additives. This process revealed that copper and selenium intake were both within the provisional tolerable weekly intake, while there is no guideline for zinc. Furthermore, participants relying heavily on wild resources from the Nambucca River estuary may exceed the provisional

Aboriginal Consumption of Estuarine Food Resources and Potential Implications for Health through Trace Metal Exposure; A Study in Gumbaynggirr Country, Australia.

Directory of Open Access Journals (Sweden)

Shaina Russell

Full Text Available Fishing and resource use continues to be an essential aspect of life for many Aboriginal communities throughout Australia. It is important for dietary sustenance, and also retains deep social, cultural and economic significance, playing a fundamental role in maintaining group cohesion, transferring cultural knowledge and affirming Indigenous identities. We surveyed approximately 20% of the Gumbaynggirr Aboriginal community of Nambucca Heads, New South Wales, Australia. This paper explores Gumbaynggirr Connection to Country and engagement in cultural practice. It quantifies fishing efforts and consumption of seafood within the community. We found 95% of the sample group fish, with the highest rate of fishing being 2-3 times a week (27%. Furthermore, 98% of participants eat seafood weekly or more frequently, up to more than once a day (24%. Survey results revealed that Myxus elongatus (Sand mullet and naturally recruited Saccostrea glomerata (Sydney rock oysters continue to be important wild resources to the Gumbaynggirr community. Trace metals were measured in M. elongatus and S. glomerata samples collected by community participants in this study. Maximum levels prescribed in the Australia New Zealand Food Standards Code were not exceeded in the edible tissue for either species, however both species exceeded the generally expected levels for zinc and copper and S. glomerata samples exceeded the generally expected level for selenium. Furthermore the average dietary exposure to trace metals from consuming seafood was calculated for the surveyed population. Trace metal intake was then compared to the provisional tolerable weekly intake prescribed by the Joint Expert Committee on Food Additives. This process revealed that copper and selenium intake were both within the provisional tolerable weekly intake, while there is no guideline for zinc. Furthermore, participants relying heavily on wild resources from the Nambucca River estuary may exceed the

The Effects of Trace Elements on the Lipid Productivity and Fatty Acid Composition of Nannochloropis oculata

Directory of Open Access Journals (Sweden)

Xiao Dou

2013-01-01

Full Text Available The effects of trace elements on the lipid productivity and fatty acid composition of Nannochloropis oculata (N. oculata were studied. The results showed that trace elements had a strong influence on not only the lipid productivity but also the fatty acid composition. The addition of Fe3+, Zn2+, Mn2+, Mo6+, and EDTA and the deletion of Cu2+ and Co2+ can increase the lipid productivity. The optimum concentrations of the trace elements in the culture medium are 6 times of Fe3+ and EDTA, the same concentration of Zn2+, Mn2+, and Mo6+ as the control group, but the optimum medium has no Cu2+ or Co2+. Fe3+, Zn2+, Mn2+, Mo6+, and EDTA are indispensable during the EPA formation of N. oculata. The addition of Fe3+, Zn2+, Mn2+, Mo6+, and EDTA can strongly increase the content of EPA in the lipid of N. oculata, but the concentration of the trace elements had little influence on the level of EPA.

Particle induced X-ray emission for quantitative trace-element analysis using the Eindhoven cyclotron

International Nuclear Information System (INIS)

Kivits, H.

1980-01-01

Development of a multi-elemental trace analysis technique using PIXE (Particle Induced X-ray Emission), was started almost five years ago at the Eindhoven University of Technology, in the Cyclotron Applications Group of the Physics Department. The aim of the work presented is to improve the quantitative aspects of trace-element analysis with PIXE, as well as versatility, speed and simplicity. (Auth.)

Tracing Clues

DEFF Research Database (Denmark)

Feldt, Liv Egholm

The past is all messiness and blurred relations. However, we tend to sort the messiness out through rigorous analytical studies leaving the messiness behind. Carlo Ginzburgs´ article Clues. Roots of an Evidential Paradigm from 1986 invigorates methodological elements of (historical) research, which...... central methodological elements will be further elaborated and discussed through a historical case study that traces how networks of philanthropic concepts and practices influenced the Danish welfare state in the period from the Danish constitution of 1849 until today. The overall aim of this paper...

Study on method of characteristics based on cell modular ray tracing

International Nuclear Information System (INIS)

Tang Chuntao; Zhang Shaohong

2009-01-01

To address the issue of accurately solving neutron transport problem in complex geometry, method of characteristics (MOC) is studied in this paper, and a quite effective and memory saving cell modular ray tracing (CMRT) method is developed and related angle discretization and boundary condition handling issues are discussed. A CMRT based MOC code-PEACH is developed and tested against C5G7 MOX benchmark problem. Numerical results demonstrate that PEACH can give excellent accuracy for both k eff and pin power distribution for neutron transport problem. (authors)

Urban environmental geochemistry of trace metals

International Nuclear Information System (INIS)

Wong, Coby S.C.; Li Xiangdong; Thornton, Iain

2006-01-01

As the world's urban population continues to grow, it becomes increasingly imperative to understand the dynamic interactions between human activities and the urban environment. The development of urban environmental geochemistry has yielded a significant volume of scientific information about geochemical phenomena found uniquely in the urban environment, such as the distribution, dispersion, and geochemical characteristics of some toxic and potentially toxic trace metals. The aim of this paper is to provide an overview of the development of urban environmental geochemistry as a field of scientific study and highlight major transitions during the course of its development from its establishment to the major scientific interests in the field today. An extensive literature review is also conducted of trace metal contamination of the urban terrestrial environment, in particular of urban soils, in which the uniqueness of the urban environment and its influences on trace metal contamination are elaborated. Potential areas of future development in urban environmental geochemistry are identified and discussed. - Urban environmental geochemistry as a scientific discipline provides valuable information on trace metal contamination of the urban environment and its associated health effects

Simulation of Iranian total mixed diets and their analysis for essential and toxic trace elements using nuclear and complementary analytical techniques

International Nuclear Information System (INIS)

Gharib, A.G.; Ahmadiniar, A.; Aminpour, A.A.

2001-01-01

Neutron activation analysis, inductively coupled plasma emission spectrometry (ICP-ES) and atomic absorption spectroscopy (AAS) have been used to determine actual daily dietary intakes of minerals and trace elements in the Iranian population. Trace elemental analysis of daily diets of the Iranian population differentiated with respect to food habits, geographical variability, literacy and income is examined. Three study groups in five regions were defined. Thirty total daily diet samples were prepared based on the method of dietary records. Also a few samples representing the intakes of two other study groups, males and females, were prepared by the duplicate diet method. Therefore, not only representative dietary patterns of almost all adult people in Iran are covered in a pilot study, but also the validity of the sampling methodology for total mixed diet simulation is checked. (author)

Process tracing in political science: What's the story?

Science.gov (United States)

Crasnow, Sharon

2017-04-01

Methodologists in political science have advocated for causal process tracing as a way of providing evidence for causal mechanisms. Recent analyses of the method have sought to provide more rigorous accounts of how it provides such evidence. These accounts have focused on the role of process tracing for causal inference and specifically on the way it can be used with case studies for testing hypotheses. While the analyses do provide an account of such testing, they pay little attention to the narrative elements of case studies. I argue that the role of narrative in case studies is not merely incidental. Narrative does cognitive work by both facilitating the consideration of alternative hypotheses and clarifying the relationship between evidence and explanation. I consider the use of process tracing in a particular case (the Fashoda Incident) in order to illustrate the role of narrative. I argue that process tracing contributes to knowledge production in ways that the current focus on inference tends to obscure. Copyright © 2017 Elsevier Ltd. All rights reserved.

Trace Elements in the Sea Surface Microlayer: Results from a Two Year Study in the Florida Keys

Science.gov (United States)

Ebling, A. M.; Westrich, J. R.; Lipp, E. K.; Mellett, T.; Buck, K. N.; Landing, W. M.

2016-02-01

Natural and anthropogenic aerosols are a significant source of trace elements to oligotrophic ocean surface waters, where they provide episodic pulses of limiting micronutrients for the microbial community. Opportunistic bacteria have been shown to experience rapid growth during deposition events. However, little is known about the fate of trace elements at the air-sea interface, i.e. the sea surface microlayer. It has been hypothesized that dust particles would be retained in the sea surface microlayer long enough to undergo chemical and physical changes that would affect the bioavailability of trace elements. In this study, aerosols, sea surface microlayer, and underlying water column samples were collected in the Florida Keys in July 2014 and May 2015 at various locations and analyzed for a suite of dissolved and particulate trace elements. Sea surface microlayer samples ( 50 μm) were collected using a cylinder of ultra-pure quartz glass; a novel adaptation of the glass plate technique. Sampling sites ranged from a more pristine environment approximately ten kilometers offshore to a more anthropogenic environment within a shallow bay a few hundred meters offshore. While it was clear from the results that dust deposition events played a large role in the chemical composition of the sea surface microlayer (elevated concentrations in dissolved and particulate trace elements associated with dust deposition), the location where the samples were collected also had a large impact on the sea surface microlayer as well as the underlying water column. The results were compared with other parameters analyzed such as Vibrio cultures as well as iron speciation, providing an important step towards our goal of understanding of the fate of trace elements in the sea surface microlayer as well as the specific effects of aeolian dust deposition on heterotrophic microbes in the upper ocean.

Trace analysis of semiconductor materials

CERN Document Server

Cali, J Paul; Gordon, L

1964-01-01

Trace Analysis of Semiconductor Materials is a guidebook concerned with procedures of ultra-trace analysis. This book discusses six distinct techniques of trace analysis. These techniques are the most common and can be applied to various problems compared to other methods. Each of the four chapters basically includes an introduction to the principles and general statements. The theoretical basis for the technique involved is then briefly discussed. Practical applications of the techniques and the different instrumentations are explained. Then, the applications to trace analysis as pertaining

Trace element accumulation in woody plants of the Guadiamar Valley, SW Spain: A large-scale phytomanagement case study

International Nuclear Information System (INIS)

Dominguez, Maria T.; Maranon, Teodoro; Murillo, Jose M.; Schulin, Rainer; Robinson, Brett H.

2008-01-01

Phytomanagement employs vegetation and soil amendments to reduce the environmental risk posed by contaminated sites. We investigated the distribution of trace elements in soils and woody plants from a large phytomanaged site, the Guadiamar Valley (SW Spain), 7 years after a mine spill, which contaminated the area in 1998. At spill-affected sites, topsoils (0-25 cm) had elevated concentrations of As (129 mg kg -1 ), Bi (1.64 mg kg -1 ), Cd (1.44 mg kg -1 ), Cu (115 mg kg -1 ), Pb (210 mg kg -1 ), Sb (13.8 mg kg -1 ), Tl (1.17 mg kg -1 ) and Zn (457 mg kg -1 ). Trace element concentrations in the studied species were, on average, within the normal ranges for higher plants. An exception was white poplar (Populus alba), which accumulated Cd and Zn in leaves up to 3 and 410 mg kg -1 respectively. We discuss the results with regard to the phytomanagement of trace element contaminated sites. - There is a low trace element transfer from contaminated soils to the aboveground parts of afforested woody plants under a semi-arid climate

A dual-trace model for visual sensory memory.

Science.gov (United States)

Cappiello, Marcus; Zhang, Weiwei

2016-11-01

Visual sensory memory refers to a transient memory lingering briefly after the stimulus offset. Although previous literature suggests that visual sensory memory is supported by a fine-grained trace for continuous representation and a coarse-grained trace of categorical information, simultaneous separation and assessment of these traces can be difficult without a quantitative model. The present study used a continuous estimation procedure to test a novel mathematical model of the dual-trace hypothesis of visual sensory memory according to which visual sensory memory could be modeled as a mixture of 2 von Mises (2VM) distributions differing in standard deviation. When visual sensory memory and working memory (WM) for colors were distinguished using different experimental manipulations in the first 3 experiments, the 2VM model outperformed Zhang and Luck (2008) standard mixture model (SM) representing a mixture of a single memory trace and random guesses, even though SM outperformed 2VM for WM. Experiment 4 generalized 2VM's advantages of fitting visual sensory memory data over SM from color to orientation. Furthermore, a single trace model and 4 other alternative models were ruled out, suggesting the necessity and sufficiency of dual traces for visual sensory memory. Together these results support the dual-trace model of visual sensory memory and provide a preliminary inquiry into the nature of information loss from visual sensory memory to WM. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Interlaboratory quality assurance studies: Their use in certifying natural waters for major constituents and trace elements

International Nuclear Information System (INIS)

Alkema, H.; Simser, J.; Hjelm, L.

1998-01-01

Environmental programs throughout North America have demonstrated a strong awareness of the usefulness of interlaboratory studies for disclosing the quality of analytical results. The Ecosystem Interlaboratory Quality Assurance Program offered by the National Water Research Institute has a wide participation base of laboratories. Many of these laboratories are accredited and employ a number of recognized analytical methods. The interlaboratory study data archives contain a wealth of data for natural surface and rain waters from across the continent. These archives have proven to be a reliable means of characterizing a variety of constituents. Data assessments from these studies accurately identify the variability of data and the presence of any outliers. Repeated use of selected samples in a regular QA program confirms their stability. Time charts and statistical techniques are used to illustrate this stability and yield the precision of pooled analyses. The availability of archived data from interlaboratory studies has enabled the Institute to develop and certify natural water and trace element standards. The natural water CRM, ION-911, has been available for several years. Its historical aspects are discussed as well as the processes leading to the certification of TMRain-95, a soft water standard certifying 22 trace elements. This paper focuses on the use of select laboratories in round-robin evaluations to provide accurate values for constituent concentrations. Natural water and fortified trace element CRMs meet a recognized need in the generation of accurate data for environmental programs. (orig.)

Trace elements as quantitative probes of differentiation processes in planetary interiors

International Nuclear Information System (INIS)

Drake, M.J.

1980-01-01

Abundances of trace elements in extrusive igneous rocks may be used as petrological and geochemical probes of the source regions of the rocks if differentiation processes, partition coefficients, phase equilibria, and initial concentrations in the source region are known. The characteristic trace element signature that each mineral in the source region imparts on the magma forms the conceptual basis for trace element modeling. The task of the trace element geochemist is to solve mathematically the inverse problem. Given trace element abundances in a magma, what is the ode of its source region. The most successful modeling has been performed for small planetary bodies which underwent relatively simple igneous differentiation events. An example is the eucrite parent body, a planet which produced basals at approx. =4.6 Gy. and has been quiescent ever since. This simple differentiation history permits the calculation of its bulk composition (a feldspathic peridotite) and has led to the tentative identification of asteroid 4 Westa as the eucrite parent body. The differentiation of iron meteorite groups in parent body cores is amenable to similar treatment. The 'anomalous' behavior of Cr, suggests that IIIA, B irons and main group pallasites equilibrated with troilite, spinel, ferromagnesian silicates, or some combination thereof. The moon has undergone more complex differentiation, and quantitative geochemical modeling is correspondingly more difficult. Nevertheless, modeling the two-stage evolution of mare basals raises the possibility that the primordial moon did not have chondritic relative abundances of such refractory elements as Ca, Al, U, and the rare-earth elements. The nonchondritic element ratios are characteristic of planetary, not nebular, fractionation processes and are consistent with the derivation of the moon from a precursor planet, possibly the earth

The Role of Memory Traces Quality in Directed Forgetting: A Comparison of Young and Older Participants

Directory of Open Access Journals (Sweden)

Fabienne Collette

2014-06-01

Full Text Available A reduced directed-forgetting (DF effect in normal aging has frequently been observed with the item method. These results were interpreted as age-related difficulties in inhibiting the processing of irrelevant information. However, since the performance of older adults is usually lower on items to remember, the age effect on DF abilities could also be interpreted as reflecting memory problems. Consequently, the present study aimed at investigating the influence of memory traces quality on the magnitude of the DF effects in normal aging. We predicted that increasing the quality of memory traces (by increasing presentation times at encoding would be associated with attenuated DF effects in older participants due to the increased difficulty of inhibiting highly activated memory traces. A classical item-method DF paradigm was administered to 48 young and 48 older participants under short and long encoding conditions. Memory performance for information to memorize and to suppress was assessed with recall and recognition procedures, as well as with a Remember/Know/Guess (RKG paradigm. The results indicated that, when memory traces are equated between groups, DF effects observed with the recall, recognition and RKG procedures are of similar amplitude in both groups (all ps>0.05. This suggests that the decreased DF effect previously observed in older adults might not actually depend on their inhibitory abilities but may rather reflect quantitative and qualitative differences in episodic memory functioning.

Trace Elements Profile among Alcohol Abusers in a Nigerian ...

African Journals Online (AJOL)

This showed that Mn, Fe and Cu were significantly increased while Zn was reduced significantly in alcohol abusers when compared with the control group of total abstainers. Excessive consumption of burukutu seems to significantly alter the trace elements status in abusers. Duration of intake and excessive use of burukutu ...

Chemical characteristics and trace element concentration of non ...

African Journals Online (AJOL)

The present study investigates the details on the aspects of Coal quality such as proximate, ultimate, calorific value and trace element concentration and its impact on human health. Trace elements are present in very low percentage in coal but their concentration increases manifold after coal combustion and utilization.

Trace elements in scalp hair of leukaemia patients

Directory of Open Access Journals (Sweden)

Khuder Ali

2014-08-01

Full Text Available The aim of this study was to determine the concentration of Fe, Ni, Cu, Zn and Pb in scalp hair of leukaemia patients and healthy volunteers, using the optimised XRF method. Leukaemia hair samples were classifi ed corresponding to type, growth and age of the participants. The results showed that the studied trace elements (TEs in both of leukaemia and control groups were positively skewed. In comparison with the control group, lower Fe, Cu, Zn and Pb and higher of Ni medians were found in all studied leukaemia patients. The median rank obtained by Mann-Whitney U-test revealed insignifi cant differences between the leukaemia patients subgroups and the controls. An exact probability (α 0.70 in the scalp hair of control group were observed between Ni/Fe-Ni, Cu/Fe-Cu, Zn/Fe-Zn, Pb/Fe-Pb, Cu/Ni-Zn/Ni, Cu/Ni-Pb/Ni, Zn/Ni-Pb/Ni, Zn/Fe-Zn/Cu, Pb/Ni-Ni and Ni/Fe-Pb/Ni, whereas only very strong positive ratios in the scalp hair of leukaemia patients group were observed between Ni/Fe-Ni, Cu/Fe-Cu, Zn/Fe-Zn and Pb/Fe-Pb, all correlations were signifi cant at p < 0.05. Other strong and signifi cant correlations were also observed in scalp hair of both groups. Signifi cant differences between grouping of studied TEs in all classifi ed leukaemia groups and controls were found using principal component analysis (PCA. The results of PCA confi rmed that the type and the growth of leukaemia factors were more important in element loading than the age factor.

Computer ray tracing speeds.

Science.gov (United States)

Robb, P; Pawlowski, B

1990-05-01

The results of measuring the ray trace speed and compilation speed of thirty-nine computers in fifty-seven configurations, ranging from personal computers to super computers, are described. A correlation of ray trace speed has been made with the LINPACK benchmark which allows the ray trace speed to be estimated using LINPACK performance data. The results indicate that the latest generation of workstations, using CPUs based on RISC (Reduced Instruction Set Computer) technology, are as fast or faster than mainframe computers in compute-bound situations.

An XPA gene splicing mutation resulting in trace protein expression in an elderly patient with xeroderma pigmentosum group A without neurological abnormalities.

Science.gov (United States)

Takahashi, Y; Endo, Y; Kusaka-Kikushima, A; Nakamaura, S; Nakazawa, Y; Ogi, T; Uryu, M; Tsuji, G; Furue, M; Moriwaki, S

2017-07-01

A certain relationship between XPA gene mutations and the severity of symptoms has been observed in patients with xeroderma pigmentosum group A (XP-A). Patients with mutations within the DNA-binding domain usually exhibit severe symptoms, whereas splicing mutations in the same domain sometimes cause very mild symptoms. This inconsistency can be explained by a small amount of functional XPA protein produced from normally spliced transcripts. We herein report the case of an adult Japanese patient with XP-A with unusually mild symptoms. We identified a homozygous c.529G>A mutation in exon 4 of the XPA gene, which resulted in aberrant splicing with a 29-bp deletion in exon 4 causing a frameshift. Intact mRNA was observable, but a Western blot analysis failed to detect any normal XPA protein. We therefore evaluated the DNA repair capacity in normal cells in which the XPA expression was artificially diminished. The repair capacity was still present in cells with trace levels of the XPA protein. The repair capacity of the cells derived from our patient with mild symptoms was poor by comparison, but still significant compared with that of the cells derived from a patient with XP-A with severe symptoms. These results provide strong evidence that a trace level of XPA protein can still exert a relatively strong repair capacity, resulting in only a mild phenotype. © 2016 British Association of Dermatologists.

Selecting appropriate cases when tracing causal mechanisms

DEFF Research Database (Denmark)

Beach, Derek; Pedersen, Rasmus Brun

2016-01-01

The last decade has witnessed resurgence in the interest in studying the causal mechanisms linking causes and outcomes in the social sciences. This article explores the overlooked implications for case selection when tracing mechanisms using in-depth case studies. Our argument is that existing case...... selection guidelines are appropriate for research aimed at making cross-case claims about causal relationships, where case selection is primarily used to control for other causes. However, existing guidelines are not in alignment with case-based research that aims to trace mechanisms, where the goal...... is to unpack the causal mechanism between X and Y, enabling causal inferences to be made because empirical evidence is provided for how the mechanism actually operated in a particular case. The in-depth, within-case tracing of how mechanisms operate in particular cases produces what can be termed mechanistic...

Fossil traces of the bone-eating worm Osedax in early Oligocene whale bones.

Science.gov (United States)

Kiel, Steffen; Goedert, James L; Kahl, Wolf-Achim; Rouse, Greg W

2010-05-11

Osedax is a recently discovered group of siboglinid annelids that consume bones on the seafloor and whose evolutionary origins have been linked with Cretaceous marine reptiles or to the post-Cretaceous rise of whales. Here we present whale bones from early Oligocene bathyal sediments exposed in Washington State, which show traces similar to those made by Osedax today. The geologic age of these trace fossils ( approximately 30 million years) coincides with the first major radiation of whales, consistent with the hypothesis of an evolutionary link between Osedax and its main food source, although older fossils should certainly be studied. Osedax has been destroying bones for most of the evolutionary history of whales and the possible significance of this "Osedax effect" in relation to the quality and quantity of their fossils is only now recognized.

The interrelation among the radiological, toxicological and some nutritional trace elements in daily diets (T3c/176)

International Nuclear Information System (INIS)

Gharib, A.G.; Hashemi, F.A.

2004-01-01

The interrelation of Cs and a few more similar functioning elements such as Sr, Rb, I, K, Mg and Ca with themselves and their relevant radio nuclides have come to consideration since 134+137 9 0 Sr and to some extent 87 Rb and 1'2 9 + 131 I:a ) can be produced in maximum level b) their have lives c) Cesium may be spread in a very long distance as the result of its low melting point and also d) their easily deposition with K, Ca, and Mg, they are potentially very much dangerous to human if they are entered to the body directly or indirectly. Also, since the diets have been prepared almost simultaneously by human investigators from various countries in different parts of the world, including Iran, in a coordinated project, therefore a comparable basis is provided. In this work almost the natural relevant elements, measured in diets. Their interrelation and interaction among their own or other group of trace elements discussed ( not only radiological but the toxicological and some nutritional trace elements). Nevertheless the protection role of these trace metals in human organs is the main issue of this assessment. The matter regarding the origin of natural cesium and radioactive fallout is to be discussed. The effect of 137 Cs and other radionuclides of the foodstuff depend upon direct exposure or via the mineral and organic content of these radionuclides in the soil and environments to be transferred to nutritive species is considered. In this work the toxicity of some trace elements (e.g. As, Cd, Pb and Hg) were studied and their interrelation with radiological elements are of interested subject. However the actual study groups are Iranian and their daily diets were prepared through dietary recording and duplicate portion. The status of toxicological trace elements in Iranian diets is to be discussed including their. environmental impacts

Trace elements in natural drugs determined by INAA

International Nuclear Information System (INIS)

Chen Kehshaw; Tseng Chialiang; Lin Tehsien

1993-01-01

Natural drugs are widely used for diuretic, phlegm elimination and stomach invigoration purposes. Seventy-five of the most common remedies used by Chinese people have been subjected to trace element survey analysis by instrumental neutron activation. Within this large number of different natural products, fourteen trace elements (K, Sc, Cr, Fe, Co, Zn, Br, Rb, Cs, La, Sm, Eu, Au and Th) are commonly detected. Among these elements, Fe had the highest concentration followed by Zn, and Rb, Sm, Eu and Au were found to have the lowest concentrations. Although the three groups of natural drugs exhibit a widely different therapeutic action, the concentration ranges of the fourteen elements were very similar. While this suggests no apparent specific role for the trace elements in the drug function, parallels are drawn between the known drug related functions of Rb, Zn, Br, Fe, Co and K and the levels of elements found in the natural drugs. It is concluded that the various natural drugs also provide human benefits through supplements of essential elements such as Fe, Zn, Cr, Sc, Rb and Co. (author) 13 refs.; 5 tabs

A versatile ray-tracing code for studying rf wave propagation in toroidal magnetized plasmas

International Nuclear Information System (INIS)

Peysson, Y; Decker, J; Morini, L

2012-01-01

A new ray-tracing code named C3PO has been developed to study the propagation of arbitrary electromagnetic radio-frequency (rf) waves in magnetized toroidal plasmas. Its structure is designed for maximum flexibility regarding the choice of coordinate system and dielectric model. The versatility of this code makes it particularly suitable for integrated modeling systems. Using a coordinate system that reflects the nested structure of magnetic flux surfaces in tokamaks, fast and accurate calculations inside the plasma separatrix can be performed using analytical derivatives of a spline-Fourier interpolation of the axisymmetric toroidal MHD equilibrium. Applications to reverse field pinch magnetic configuration are also included. The effects of 3D perturbations of the axisymmetric toroidal MHD equilibrium, due to the discreteness of the magnetic coil system or plasma fluctuations in an original quasi-optical approach, are also studied. Using a Runge–Kutta–Fehlberg method for solving the set of ordinary differential equations, the ray-tracing code is extensively benchmarked against analytical models and other codes for lower hybrid and electron cyclotron waves. (paper)

Linear scans of hair strands for trace elements by proton induced x-ray emission

International Nuclear Information System (INIS)

Jolly, R.K.; Pehrson, G.R.; Gupta, S.K.; Buckle, D.C.; Aceto, H. Jr.

1974-01-01

Hair strands obtained from school children in the 10 to 12 year age group were analyzed for trace element concentration as a function of distance from the root by proton-induced x-ray emission to study the history of exposure of the donors to toxic trace metals. These samples were collected from the vicinity of a copper smelter where high levels of As, Cd, Sb, and Pb have been noted. Scans show a continual build-up of Pb as a function of distance from the root, while As shows a reproducible and distinct maximum approximately 10 cm from the root. The concentration of Zn was found to be constant in all samples (without exception) to within the uncertainties of our measurements

Removal of trace organic chemical contaminants by a membrane bioreactor.

Science.gov (United States)

Trinh, T; van den Akker, B; Stuetz, R M; Coleman, H M; Le-Clech, P; Khan, S J

2012-01-01

Emerging wastewater treatment processes such as membrane bioreactors (MBRs) have attracted a significant amount of interest internationally due to their ability to produce high quality effluent suitable for water recycling. It is therefore important that their efficiency in removing hazardous trace organic contaminants be assessed. Accordingly, this study investigated the removal of trace organic chemical contaminants through a full-scale, package MBR in New South Wales, Australia. This study was unique in the context of MBR research because it characterised the removal of 48 trace organic chemical contaminants, which included steroidal hormones, xenoestrogens, pesticides, caffeine, pharmaceuticals and personal care products (PPCPs). Results showed that the removal of most trace organic chemical contaminants through the MBR was high (above 90%). However, amitriptyline, carbamazepine, diazepam, diclofenac, fluoxetine, gemfibrozil, omeprazole, sulphamethoxazole and trimethoprim were only partially removed through the MBR with the removal efficiencies of 24-68%. These are potential indicators for assessing MBR performance as these chemicals are usually sensitive to changes in the treatment systems. The trace organic chemical contaminants detected in the MBR permeate were 1 to 6 orders of magnitude lower than guideline values reported in the Australian Guidelines for Water Recycling. The outcomes of this study enhanced our understanding of the levels and removal of trace organic contaminants by MBRs.

Working group report: methane emissions from biomass burning

International Nuclear Information System (INIS)

Delmas, R.A.; Ahuja, D.

1993-01-01

Biomass burning is a significant source of atmospheric methane. Like most other sources of methane, it has both natural and anthropogenic causes, although anthropogenic causes now predominate. Most of the estimates of methane emissions from biomass burning in the past have relied on a uniform emission factor for all types of burning. This results in the share of trace gas emissions for different types of burning being the same as the amounts of biomass burned in those types. The Working Group endorsed the extension of an approach followed for Africa by Delmas et al. (1991) to use different emission factors for different types of biomass burning to estimate national emissions of methane. This is really critical as emission factors present important variations. While the focus of discussions of the Working Group was on methane emissions from biomass burning, the Group endorsed the IPCC-OECD methodology of estimating all greenhouse related trace gases from biomass burning. Neither the IPCC-OECD nor the methodology suggested here applies to estimation of trace gas emissions from the processing of biomass to upgraded fuels. They must be estimated separately. The Group also discussed technical options for controlling methane emissions from biomass. 12 refs

Biliary excretion of essential trace elements in rats under oxidative stress caused by selenium deficiency

Energy Technology Data Exchange (ETDEWEB)

Yamasaki, Kosuke; Tsukada, Masamichi [Meiji University, School of Agriculture, Kawasaki, Kanagawa (Japan); Sakuma, Yasunobu; Sasaki, Junya; Matsuoka, Keisuke; Honda, Chikako; Endo, Kazutoyo [Showa Pharmaceutical University, Department of Physical Chemistry, Machida, Tokyo (Japan); Matsumoto, Ken-ichiro; Anzai, Kazunori [National Institute of Radiological Science, Research Center for Charged Particle Therapy, Chiba (Japan); Enomoto, Shuichi [The Institute of Physical and Chemical Research (RIKEN), Radioisotope Technology Division, Cyclotron Center, Wako, Saitama (Japan); Okayama University, Department of Analytical Chemistry, School of Pharmacy, Okayama (Japan)

2011-11-15

The excretion of essential trace elements, namely, Se, Sr, As, Mn, Co, V, Fe, and Zn into the bile of Se-deficient (SeD) Wistar male rats was studied using the multitracer (MT) technique, and instrumental neutron activation analysis (INAA). Normal and Se-control (SeC) rat groups were used as reference groups to compare the effects of Se levels on the behaviors of the essential trace elements. The excretion (% dose) of Se, Sr, As, Mn, Co, and V increased with Se levels in the liver. The biliary excretion of Mn and As dramatically enhanced for SeC rats compared with SeD rats, while that of V accelerated a little for SeC rats. The radioactivity levels of {sup 59}Fe and {sup 65}Zn in the MT tracer solution were insufficient to measure their excretion into bile. The role of glutathione and bilirubin for biliary excretion of the metals was discussed in relation to Se levels in rat liver. (orig.)

Sorption of trace amounts of gallium (III) on iron (III) oxide

International Nuclear Information System (INIS)

Music, S.; Gessner, M.; Wolf, R.H.H.

1979-01-01

The sorption of trace amounts of gallium(III) on iron(III) oxide has been studied as a function of pH. Optimum conditions have been found for the preconcentration of traces of gallium(III) by iron(III) oxide. The influence of surface active substances and of complexing agents on the sorption of trace amounts of gallium(III) on iron(III) oxide has been also studied. (orig.) [de

Sorption of trace amounts of gallium (III) on iron (III) oxide

Energy Technology Data Exchange (ETDEWEB)

Music, S; Gessner, M; Wolf, R H.H. [Institut Rudjer Boskovic, Zagreb (Yugoslavia)

1979-01-01

The sorption of trace amounts of gallium(III) on iron(III) oxide has been studied as a function of pH. Optimum conditions have been found for the preconcentration of traces of gallium(III) by iron(III) oxide. The influence of surface active substances and of complexing agents on the sorption of trace amounts of gallium(III) on iron(III) oxide has been also studied.

Frequency distribution of ABO and Rh (D) blood group alleles in Silte Zone, Ethiopia

OpenAIRE

Kassahun Tesfaye; Yohannes Petros; Mebeaselassie Andargie

2015-01-01

Background: Frequency distribution of blood groups is important as it is used in modern medicine, genetic research, anthropology, and tracing ancestral relations of humans. The ABO and Rh blood groups are the most important blood groups despite the long list of several other blood groups discovered so far. Aim of the study: To study and document the frequency of ABO and Rh (D) blood groups in three ethnic groups of Silte Zone, Ethiopia. Subjects and methods: ABO and Rh (D) typing was ca...

Effects of Different Levels of Molybdenum on Rumen Microbiota and Trace Elements Changes in Tissues from Goats.

Science.gov (United States)

Zhou, Sihui; Zhang, Caiying; Xiao, Qingyang; Zhuang, Yu; Gu, Xiaolong; Yang, Fan; Xing, Chenghong; Hu, Guoliang; Cao, Huabin

2016-11-01

Molybdenum (Mo) is an essential trace element for animals and human beings. However, the negative effects on rumen function and distribution of trace elements in tissues induced by excessive Mo have not been well understood. Therefore, the purpose of present study was to investigate the impact of Mo on rumen microbiota, distribution of trace elements in various organs, and hematological parameters of goats. A total of 36 goats were randomly distributed into three groups with equal number and low-Mo and high-Mo groups were orally administered ammonium molybdate at 15 and 45 mg · Mo · kg -1  · BW respectively, while the control group received corresponding quantitative deionized water. The results showed that the total number of ciliate and protozoa protein concentration decreased significantly (P contents significantly decreased (P contents increased (P contents were not obvious (P > 0.05) in other tissues on days 25 and 50. Besides, there was no obvious variation in iron (Fe) contents during whole experiment period (P > 0.05). Furthermore, excessive Mo content had no significant effect on red blood cell (RBC) counts and hemoglobin (HGB) concentration (P > 0.05) on days 25 and 50, while white blood cell (WBC) counts increased significantly (P content could impact the balance of ruminal microorganisms and interfere with the absorption and distribution of Mo and Cu mainly.

Uncertainty and Sensitivity Studies with TRACE-SUSA and TRACE-DAKOTA by Means of Transient BFBT Data

Directory of Open Access Journals (Sweden)

Wadim Jaeger

2013-01-01

Full Text Available In the present paper, an uncertainty and sensitivity study is performed for transient void fraction and pressure drop measurements. Two transients have been selected from the NUPEC BFBT database. The first one is a turbine trip without bypass and the second one is a trip of a recirculation pump. TRACE (version 5.0 patch 2 is used for the thermohydraulic study and SUSA and DAKOTA are used for the quantification of the model uncertainties and the evaluation of the sensitivities. As uncertain parameters geometrical values, hydraulic diameter, and wall roughness are considered while mass flow rate, power, pressure, and inlet subcooling (inlet temperature are chosen as boundary and input conditions. Since these parameters change with time, it is expected that the importance of them on pressure drop and void fraction will change, too. The results show that the pressure drop is mostly sensitive to geometrical variations like the hydraulic diameter and the form loss coefficient of the spacer grid. For low void fractions, the parameter of the highest importance is the inlet temperature/subcooling while at higher void fraction the power is also of importance.

Differential accumulation of mercury and other trace metals in the food web components of a reservoir impacted by a chlor-alkali plant (Flix, Ebro River, Spain): Implications for biomonitoring

Energy Technology Data Exchange (ETDEWEB)

Soto, David X., E-mail: david.soto@ec.gc.ca [Centre for Advanced Studies of Blanes (CEAB-CSIC), Acces a la Cala St. Francesc 14, 17300 Blanes (Spain); Roig, Romero; Gacia, Esperanca; Catalan, Jordi [Centre for Advanced Studies of Blanes (CEAB-CSIC), Acces a la Cala St. Francesc 14, 17300 Blanes (Spain)

2011-06-15

Comparative studies of biomonitors of trace metal contamination are relatively scarce. We took advantage of a point source pollution in a reservoir (Flix, Spain) to compare trace metal (Hg, Pb, Cd, Se, As, Zn, Cu, Cr) bioaccumulation patterns among 16 food web components. Our results indicate that most organisms are suitable for Hg biomonitoring, whereas other metals are better monitored by only some of them. Biofilms and zebra mussel were the organisms with larger and more diverse biomonitoring capacity. However, we show that using groups of biomonitors increase the scope and strengths of the conclusions and specific goals can be better addressed. We conclude providing an overview of the strengths and weaknesses of the main organisms considered for biomonitoring trace metals in rivers and reservoirs. - Highlights: > We compare many food web components of a reservoir for trace metal bioaccumulation. > Most organisms are suitable for Hg biomonitoring. > Biofilms and zebra mussel showed more general biomonitoring capacity. > Other organisms showed strengths for specific metals or environmental compartments. > The use of a group of biomonitors increases the scope and strengths of conclusions. - The use of a group of biomonitors increases the scope and strengths of conclusions in trace metal biomonitoring.

A Novel Hybrid Model for Drawing Trace Reconstruction from Multichannel Surface Electromyographic Activity.

Science.gov (United States)

Chen, Yumiao; Yang, Zhongliang

2017-01-01

Recently, several researchers have considered the problem of reconstruction of handwriting and other meaningful arm and hand movements from surface electromyography (sEMG). Although much progress has been made, several practical limitations may still affect the clinical applicability of sEMG-based techniques. In this paper, a novel three-step hybrid model of coordinate state transition, sEMG feature extraction and gene expression programming (GEP) prediction is proposed for reconstructing drawing traces of 12 basic one-stroke shapes from multichannel surface electromyography. Using a specially designed coordinate data acquisition system, we recorded the coordinate data of drawing traces collected in accordance with the time series while 7-channel EMG signals were recorded. As a widely-used time domain feature, Root Mean Square (RMS) was extracted with the analysis window. The preliminary reconstruction models can be established by GEP. Then, the original drawing traces can be approximated by a constructed prediction model. Applying the three-step hybrid model, we were able to convert seven channels of EMG activity recorded from the arm muscles into smooth reconstructions of drawing traces. The hybrid model can yield a mean accuracy of 74% in within-group design (one set of prediction models for all shapes) and 86% in between-group design (one separate set of prediction models for each shape), averaged for the reconstructed x and y coordinates. It can be concluded that it is feasible for the proposed three-step hybrid model to improve the reconstruction ability of drawing traces from sEMG.

Enhanced identification of trace element fingerprint of prehistoric pigments by PIXE mapping

Science.gov (United States)

Lebon, M.; Pichon, L.; Beck, L.

2018-02-01

The elemental composition of Fe rich rocks used as pigment during prehistoric periods can provide valuable information about the type of material used and their geological origin. However, these materials present several analytical constraints since their patrimonial value involve using non-invasive techniques maintaining a high sensitivity of the detection and the quantification of trace elements. Micro-beam techniques also require to take into account the heterogeneity of these geomaterials from the macroscopic to microscopic scales. Several previous studies have demonstrated that PIXE analysis satisfies these analytical conditions. However, application of micro-PIXE analysis is still complex when thin and discontinuous layer of pigment is deposed on the surface of other materials such as rocks or bones. In such case, PIXE imaging could improve the ability to take into account the high heterogeneity of such archaeological objects. In study, we used PIXE imaging system developed at the NewAGLAE facility in order to visualize distribution of elements associated with iron-rich pigment phase. The results obtained show that PIXE maps can improve the identification of the main trace elements specific to the iron mineral phase. By grouping pixels of iron-rich areas and performing quantitative treatment, it was possible to reveal additional trace elements associated to pigment. This study highlights the contribution of PIXE imaging to the identification of elements associated with mineral phases of interest and to use them as proxies to discriminate different geological materials used in archaeological context.

Trace elements distribution in environmental compartments

Energy Technology Data Exchange (ETDEWEB)

Queiroz, Juliana C. de; Peres, Sueli da Silva; Godoy, Maria Luiza D.P., E-mail: suelip@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2017-11-01

Trace elements term defines the presence of low concentrations metals at environment. Some of them are considered biologically essential, as Co, Cu and Mn. Others can cause detriment to environment and human health, as Pb, Cd, Hg, As, Ti and U. A large number of them have radioactive isotopes, implying the evaluation of risks for human health should be done considering the precepts of environmental radiological protection. The ecosystem pollution with trace elements generates changes at the geochemistry cycle of these elements and in environmental quality. Soils have single characteristics when compared with another components of biosphere (air, water and biota), cause they introduce themselves not only as a drain towards contaminants, but also as natural buffer that control the transport of chemical elements and other substances for atmosphere, hydrosphere and biota. The main purpose of environmental monitoring program is to evaluate the levels of contaminants in the various compartments of the environment: natural or anthropogenic, and to assess the contribution of a potential contaminant source on the environment. Elemental Composition for the collected samples was determined by inductively coupled plasma mass spectroscopy. The main objective of this work was to evaluate the map baseline of concentration of interest trace elements in environmental samples of water, sediment and soil from Environmental Monitoring Program of Instituto de Radioprotecao e Dosimetria (IRD). The samples were analyzed using an inductively coupled plasma mass spectrometer (ICP-MS) at IRD. >From the knowledge of trace elements concentrations, could be evaluated the environmental quality parameters at the studied ecosystems. The data allowed evaluating some relevant aspects of the study of trace elements in soil and aquatic systems, with emphasis at the distribution, concentration and identification of main anthropic sources of contamination at environment. (author)

Trace elements distribution in environmental compartments

International Nuclear Information System (INIS)

Queiroz, Juliana C. de; Peres, Sueli da Silva; Godoy, Maria Luiza D.P.

2017-01-01

Trace elements term defines the presence of low concentrations metals at environment. Some of them are considered biologically essential, as Co, Cu and Mn. Others can cause detriment to environment and human health, as Pb, Cd, Hg, As, Ti and U. A large number of them have radioactive isotopes, implying the evaluation of risks for human health should be done considering the precepts of environmental radiological protection. The ecosystem pollution with trace elements generates changes at the geochemistry cycle of these elements and in environmental quality. Soils have single characteristics when compared with another components of biosphere (air, water and biota), cause they introduce themselves not only as a drain towards contaminants, but also as natural buffer that control the transport of chemical elements and other substances for atmosphere, hydrosphere and biota. The main purpose of environmental monitoring program is to evaluate the levels of contaminants in the various compartments of the environment: natural or anthropogenic, and to assess the contribution of a potential contaminant source on the environment. Elemental Composition for the collected samples was determined by inductively coupled plasma mass spectroscopy. The main objective of this work was to evaluate the map baseline of concentration of interest trace elements in environmental samples of water, sediment and soil from Environmental Monitoring Program of Instituto de Radioprotecao e Dosimetria (IRD). The samples were analyzed using an inductively coupled plasma mass spectrometer (ICP-MS) at IRD. >From the knowledge of trace elements concentrations, could be evaluated the environmental quality parameters at the studied ecosystems. The data allowed evaluating some relevant aspects of the study of trace elements in soil and aquatic systems, with emphasis at the distribution, concentration and identification of main anthropic sources of contamination at environment. (author)

Interactive Stable Ray Tracing

DEFF Research Database (Denmark)

Dal Corso, Alessandro; Salvi, Marco; Kolb, Craig

2017-01-01

Interactive ray tracing applications running on commodity hardware can suffer from objectionable temporal artifacts due to a low sample count. We introduce stable ray tracing, a technique that improves temporal stability without the over-blurring and ghosting artifacts typical of temporal post-pr...

INAA Application for Trace Element Determination in Biological Reference Material

Science.gov (United States)

Atmodjo, D. P. D.; Kurniawati, S.; Lestiani, D. D.; Adventini, N.

2017-06-01

Trace element determination in biological samples is often used in the study of health and toxicology. Determination change to its essentiality and toxicity of trace element require an accurate determination method, which implies that a good Quality Control (QC) procedure should be performed. In this study, QC for trace element determination in biological samples was applied by analyzing the Standard Reference Material (SRM) Bovine muscle 8414 NIST using Instrumental Neutron Activation Analysis (INAA). Three selected trace element such as Fe, Zn, and Se were determined. Accuracy of the elements showed as %recovery and precision as %coefficient of variance (%CV). The result showed that %recovery of Fe, Zn, and Se were in the range between 99.4-107%, 92.7-103%, and 91.9-112%, respectively, whereas %CV were 2.92, 3.70, and 5.37%, respectively. These results showed that INAA method is precise and accurate for trace element determination in biological matrices.

Effects of trace elements on urease activity in soils

Energy Technology Data Exchange (ETDEWEB)

Tabatabai, M A

1977-01-01

Disposal of sewage sludges and effluents on agricultural land is becoming a widespread practice. Most sludge samples disposed on soils contain large quantities of various trace elements. Studies of 20 trace elements commonly found in sludge samples showed that they inhibit the activity of urease in soils and that their order of effectiveness as inhibitors of urease depends on the soil. When the trace elements were compared by using 5 ..mu..mol . g/sup -1/ soil, however, some of them showed the same order of effectiveness as urease inhibitors in the six soils studied i.e., for the monovalent and divalent ions. Ag/sup +/ greater than or equal to Hg/sup 2 +/ > Cu/sup 2 +/ > Cd/sup 2 +/ > Zn/sup 2 +/ > Sn/sup 2 +/ > Mn/sup 2 +/, and generally, Fe/sup 3 +/ > Fe/sup 2 +/ and Cu/sup 2 +/ > Cu/sup +/. Other trace element ions that inhibited urease were Ni/sup 2 +/, Co/sup 2 +/, Pb/sup 2 +/, Ba/sup 2 +/, As/sup 3 +/, B/sup 3 +/, Cr/sup 3 +/, Al/sup 3 +/, V/sup 4 +/, Se/sup 4 +/, and Mo/sup 6 +/. Of the trace element ions studied, only As/sup 5 +/ and W/sup 6 +/ did not inhibit urease activity in soils. Studies on the distribution of urease activity showed that it is concentrated in surface soils and decreases with depth. Urease activity was proportional to organic C distribution in each soil profile and was significantly correlated with organic C in the surface soils studied.

Clinical relevance of trace element measurement in patients on initiation of parenteral nutrition.

Science.gov (United States)

Salota, Rashim; Omar, Sohail; Sherwood, Roy A; Raja, Kishor; Vincent, Royce P

2016-11-01

Background and Aims Serum zinc, copper and selenium are measured in patients prior to commencing on parenteral nutrition; however, their interpretation can be difficult due to acute phase reactions. We assessed (i) the relationship of raised C-reactive protein with trace elements and albumin (ii) benefits of measuring trace elements when C-reactive protein is raised in patients requiring short-term parenteral nutrition. Methods Samples were collected for zinc, copper, selenium and albumin at baseline and then every two weeks and correlated with C-reactive protein results in patients on parenteral nutrition. Results were categorized into four groups based on the C-reactive protein concentrations: (i)  0.05), whereas selenium and albumin were lower in the group with C-reactive protein > 40 mg/L ( P parenteral nutrition, measurement of C-reactive protein is essential when interpreting zinc and selenium but not copper results. Routine measurement of trace elements prior to commencing parenteral nutrition has to be considered on an individual basis in patients with inflammation.

Tracing students' attention through the Neurosky MindWave headset

DEFF Research Database (Denmark)

Ringtved, Ulla Lunde; Larsen, Torben; Toftegaard, Lars Landberg

This poster explores how students` attention levels can be traced through recordings of their electroencephalography (EEG) signals. The EEG signals are recorded through the Neurosky MindWave headset during lectures in the classroom. We configured and aggregated the recordings searching for simila......This poster explores how students` attention levels can be traced through recordings of their electroencephalography (EEG) signals. The EEG signals are recorded through the Neurosky MindWave headset during lectures in the classroom. We configured and aggregated the recordings searching...... for similarity in the signals throughout the group of students to create a dashboard and use them as pedagogical neurofeedback to increase the students` capabilities in controlling their attention and concentration in learning situations. Furthermore, learning analytics methods are deployed to create a prototype...

Determining trace element in hair of children with mental retardation

International Nuclear Information System (INIS)

Wang Zhilan; Gu Bomei; Jia Meixiang

1992-01-01

Seven trace elements in the hair come from 29 mental retardation children and 29 normal children have been analysed by INAA and XRF. There are significant differences for Fe and Sc between the two groups. The average value of Pb in the hair of the mental retardation children is higher than that of the normal children. Although Zn is very important for children growing, there is no significant difference between two children groups

Comparative international studies of osteoporosis using isotope techniques. Report of an IAEA advisory group meeting held in Vienna, Austria, 28-30 October 1992

International Nuclear Information System (INIS)

1992-01-01

An Advisory Group Meeting convened by the IAEA in October 1992 made recommendations on the setting up of a Co-ordinated Research Programme (CRP) using nuclear and isotopic techniques for international comparative studies of osteoporosis. The proposed CRP will be implemented by the IAEA during the period 1993-1997. The main purpose of this programme is to undertake pilot studies of bone density in selected developing country populations for the purposes of (i) determining the age of peak bone mass in each study group, and (ii) quantifying differences in bone density as functions of the age and sex of persons in the study groups, as well as quantifying differences between the study groups in different countries. The preferred technique for bone density measurements in this study is DEXA (dual energy X-ray absorptiometry). Additional measurements of trace elements in bone (and possibly also teeth) are also foreseen using neutron activation analysis and other appropriate techniques

Computation and analysis of backward ray-tracing in aero-optics flow fields.

Science.gov (United States)

Xu, Liang; Xue, Deting; Lv, Xiaoyi

2018-01-08

A backward ray-tracing method is proposed for aero-optics simulation. Different from forward tracing, the backward tracing direction is from the internal sensor to the distant target. Along this direction, the tracing in turn goes through the internal gas region, the aero-optics flow field, and the freestream. The coordinate value, the density, and the refractive index are calculated at each tracing step. A stopping criterion is developed to ensure the tracing stops at the outer edge of the aero-optics flow field. As a demonstration, the analysis is carried out for a typical blunt nosed vehicle. The backward tracing method and stopping criterion greatly simplify the ray-tracing computations in the aero-optics flow field, and they can be extended to our active laser illumination aero-optics study because of the reciprocity principle.

Interactive influences of bioactive trace metals on biological production in oceanic waters

International Nuclear Information System (INIS)

Bruland, K.W.; Donat, J.R.; Hutchins, D.A.

1991-01-01

The authors present an overview of the oceanic chemistries of the bioactive trace metals, Mn, Fe, Co, Ni, Cu, and Zn; the authors combine field data with results from laboratory phytoplankton culture-trace metal studies and speculate on the potential influences of these trace metals on oceanic plankton production and species composition. Most field studies have focused on the effects of single metals. However, they propose that synergistic and antagonistic interactions between multiple trace metals could be very important in the oceans. Trace metal antagonisms that may prove particularly important are those between Cu and the potential biolimiting metals Fe, Mn, and Zn. These antagonistic interactions could have the greatest influence on biological productivity in areas of the open ocean isolated from terrestrial inputs, such as the remote high nutrient regions of the Pacific and Antarctic Oceans. The emerging picture of trace metal-biota interactions in these oceanic areas is one in which biology strongly influences distribution and chemical speciation of all these bioactive trace metals. It also seems likely that many of these bioactive trace metals and their speciation may influence levels of primary productivity, species composition, and trophic structure. Future investigations should give more complete consideration to the interactive effects of biologically important trace metals

Trace-element speciation and partitioning in environmental geochemistry and health

Energy Technology Data Exchange (ETDEWEB)

Farmer, J.G.; Gibson, M.J.; Lovell, M.A.

1983-09-01

Establishment of the chemical form and associations of trace elements is important in the scientifc and medical fields related to environmental geochemistry and health. Fundamental understanding of trace-element behavior, the realistic formulation of historical perspectives of trace-element contamination, an assessment of environmental transformation processes and a thorough appraisal of environment-related ill health and disease all depend on knowledge of the chemical speciation and partitioning of trace elements. These topics and the development of analytical speciation techniques and procedures are discussed with reference to trace-element studies in the Department of Forensic Medicine and Science, University of Glasgow, on lacustrine sediments and water, the atmosphere, soil and street dirt of an urban environment, and human biological fluids. 206 references, 4 figures.

Trace element determinations in brain tissues from normal and clinically demented individuals

International Nuclear Information System (INIS)

Saiki, Mitiko; Genezini, Frederico A.; Leite, Renata E.P.; Grinberg, Lea T.; Ferretti, Renata E.L.; Suemoto, Claudia; Pasqualucci, Carlos A.; Jacob-Filho, Wilson

2013-01-01

Studies on trace element levels in human brains under normal and pathological conditions have indicated a possible correlation between some trace element concentrations and neurodegenerative diseases. In this study, analysis of brain tissues was carried out to investigate if there are any differences in elemental concentrations between brain tissues from a normal population above 50 years of age presenting Clinical Dementia Rating (CDR) equal to zero (CDR=0) and that cognitively affected population ( CDR=3). The tissues were dissected, ground, freeze-dried and then analyzed by instrumental neutron activation analysis. Samples and elemental standards were irradiated in a neutron flux at the IEA-R1 nuclear research reactor for Br, Fe, K, Na, Rb, Se and Zn determinations. The induced gamma ray activities were measured using a hyperpure Ge detector coupled to a gamma ray spectrometer. The one-way ANOVA test (p< 0.05) was used to compare the results. All the elements determined in the hippocampus brain region presented differences between the groups presenting CDR=0 and CDR=3. In the case of frontal region only the elements Na, Rb and Zn showed differences between these two groups. These findings proved the correlation between elemental levels present in brain tissues neurodegenerative diseases. Biological standard reference materials SRM 1566b Oyster Tissue and SRM 1577b Bovine Liver analyzed for quality control indicated good accuracy and precision of the results. (author)

Neural population-level memory traces in the mouse hippocampus.

Science.gov (United States)

Chen, Guifen; Wang, L Phillip; Tsien, Joe Z

2009-12-16

One of the fundamental goals in neurosciences is to elucidate the formation and retrieval of brain's associative memory traces in real-time. Here, we describe real-time neural ensemble transient dynamics in the mouse hippocampal CA1 region and demonstrate their relationships with behavioral performances during both learning and recall. We employed the classic trace fear conditioning paradigm involving a neutral tone followed by a mild foot-shock 20 seconds later. Our large-scale recording and decoding methods revealed that conditioned tone responses and tone-shock association patterns were not present in CA1 during the first pairing, but emerged quickly after multiple pairings. These encoding patterns showed increased immediate-replay, correlating tightly with increased immediate-freezing during learning. Moreover, during contextual recall, these patterns reappeared in tandem six-to-fourteen times per minute, again correlating tightly with behavioral recall. Upon traced tone recall, while various fear memories were retrieved, the shock traces exhibited a unique recall-peak around the 20-second trace interval, further signifying the memory of time for the expected shock. Therefore, our study has revealed various real-time associative memory traces during learning and recall in CA1, and demonstrates that real-time memory traces can be decoded on a moment-to-moment basis over any single trial.

Neural population-level memory traces in the mouse hippocampus.

Directory of Open Access Journals (Sweden)

Guifen Chen

2009-12-01

Full Text Available One of the fundamental goals in neurosciences is to elucidate the formation and retrieval of brain's associative memory traces in real-time. Here, we describe real-time neural ensemble transient dynamics in the mouse hippocampal CA1 region and demonstrate their relationships with behavioral performances during both learning and recall. We employed the classic trace fear conditioning paradigm involving a neutral tone followed by a mild foot-shock 20 seconds later. Our large-scale recording and decoding methods revealed that conditioned tone responses and tone-shock association patterns were not present in CA1 during the first pairing, but emerged quickly after multiple pairings. These encoding patterns showed increased immediate-replay, correlating tightly with increased immediate-freezing during learning. Moreover, during contextual recall, these patterns reappeared in tandem six-to-fourteen times per minute, again correlating tightly with behavioral recall. Upon traced tone recall, while various fear memories were retrieved, the shock traces exhibited a unique recall-peak around the 20-second trace interval, further signifying the memory of time for the expected shock. Therefore, our study has revealed various real-time associative memory traces during learning and recall in CA1, and demonstrates that real-time memory traces can be decoded on a moment-to-moment basis over any single trial.

Study of the migration of toxic metals in steelmaking waste using radioactive tracing

International Nuclear Information System (INIS)

Andre, C.; Jauzein, M.; Charentus, T.; Margrita, R.; Dechelette, O.

1991-01-01

The danger presented by toxic metals contained in steelmaking wastes put into slag piles may be neutralized by suitably chosen alternation of these wastes when they are deposited. Presentation of a study method using radioactive tracing of the migration of toxic metal (cadmium, zinc, chromium) in steelmaking wastes (slag, blast furnace sludge). This non destructive method was used in columns in the laboratory, but may be used in on-site slag piles [fr

Effect of smoking on vitamin A, vitamin E, and other trace elements in patients with cardiovascular disease in Bangladesh: a cross-sectional study

Directory of Open Access Journals (Sweden)

Mitra Amal K

2004-10-01

Full Text Available Abstract Background Data regarding the impact of cigarette smoking on trace elements are scarce and inconsistent. In this study, we evaluated the effect of smoking on serum concentrations of trace elements among adult males with heart disease. Methods This cross-sectional study included 100 adults hospitalized with heart disease in Bangladesh. The major variables of interest included mean serum concentrations of trace elements and proportion of subjects with bacterial growth on throat swab culture. Results Smokers had significantly lower serum concentrations of retinol, alpha-tocopherol, selenium, and zinc and increased concentrations of copper. Throat swab cultures were more often positive for Streptococcus β-hemolyticus in smokers than controls. Conclusions Smoking decreases serum concentrations of trace elements. Smoking control programs are needed in Bangladesh to improve health and nutrition of the people who are already nutritionally deficient.

a Baseline Study of Physico-Chemical Parameters and Trace Metals in Waters of Manakudy, South-West Coast of India

Science.gov (United States)

Subramanian, M.; Muthumanikkam, J.

2013-05-01

The transport of trace metals from the land to ocean has a number of different routes and efficiencies. The sources of toxic elements into the rivers to be debouched into the sea through estuaries are either weathered naturally from the soils and rocks or introduced anthropogenically from point or non-point sources, in labile form or in particulate form. However, recent studies indicate that the transport of trace elements to the aquatic environment is much more complex than what has been thought. The chemistry and ecology of an estuarine system are entirely different from the fluvial as well as the marine system. Estuarine environment is characterized by a constantly changing mixture of salt and freshwater. In the present study area Manakudy estuary is situated about 8 kilometres north west of Kanyakumari (Latitude N 08 05 21.8 and Longitude E 077 29 03.7). To gain a better understanding of the geochemical behavior of physico-chemical parameters and trace elements in the estuary and to examine variations in associated chemical changes, 20 water samples were collected throughout the Manakudy estuary, a minor river in south-western India. These samples, collected in typical dry season during 2012, were analyzed for physico-chemical parameters, dissolved major and trace elements. Our results show that dissolved Na, Mg, Ca and Cl behave conservatively along the salinity gradient. The concentration of nutrients is normal and they are due to the higher organic activity in soils as well as faster rates of chemical weathering reaction in the source region. The concentration of major ions is due to tidal influence and it increases with salinity and the nutrients do behave non-conservatively due to biogenic removal. The conservative behaviour of the trace metals with salinity has been strongly affected by the introduction of these metals by external sources. Even though the trace metals in the contaminated water have been removed and incorporated in sediments due to

Bejing synchrotron radiation TXRF facility and its applications on trace element study of cells

International Nuclear Information System (INIS)

Yuying, H.; Yingrong, W.; Limin, Z.; Guangcheng, L.; Wie, H.

2000-01-01

In this paper, Beijing synchrotron radiation TXRF facility and experimental method were described. The minimum detection limits of some elements were tested by using several kinds of standard reference materials. The feasibility of using TXRF in biomedical field is discussed. With this technique small intestine cells of both normal and radiated white mice were analyzed, and the elemental average contents of each single cell are also given. The results indicated that the contents of some trace elements for normal and radiated white mice are greatly different, which may be used to provide valuable reference for clinic medicine. On the other hand, the trace elements of cells of lung and cervix cancer before and after apoptosis were determined by SRTXRF and the changes of trace elements in these cells were discussed. (author)

Retrograde tracing of fluorescent gold after autogenous nerve transplantation on spinal cord injured in rats

DEFF Research Database (Denmark)

Lin, X; Liu, W; Ding, Ming

2016-01-01

, the transplantation group using autologous sural nerve graft to repair spinal cord injury period and non-transplantation group was only exposed incision without treatment. In the 4, 6 and 8 weeks after operation, the retrograde tracing of FG Fluoro-Gold was performed to discover the recovery of the axial plasma......Objective To investigate the changes of the fluorescent gold retrograde tracing autogenous nerve transplantation on spinal cord injured in rats. Methods The animals were divided into two groups, with modified Allen impact method to establish model of spinal cord injury. After 4 weeks.......01). Conclusion After spinal cord injury, autologous nerve graft was repaired and survived well and promote the recovery of spinal cord injury segment shaft pulp transportation function....

Determination of trace elements in tailpipe fish produced in artificial farms and from white and blue nile

International Nuclear Information System (INIS)

Ahmed, Zeinb Khalil Elsaim

2017-01-01

In this study, an analytical protocol of x-ray fluorescence spectroscopy was used to determine the concentration of 13 trace elements, potassium (K), antimony (Sb), iron (Fe), copper (Cu), zinc (Zn), lead (Pb), bromine (Br), rubidium (Rb), strontium (Sr), mercury (Hg), chromium (Cu), manjense (Mn), and calcium (Ca), in tilapa fish. A total of 70 samples covering 35 fish samples collected from different states includes Eldamazine for blue nile samples and the Mawrada market for the white nile samples and 5 artificial fish farms samples were collected from Om badda in Omdurman and Bahry state for three farms Alsamraband Aldorshab and from Alshagra state in Khartoum, during may to June 2016. The trace elements detected in all samples, and the concentration in part million (ppm). The concentrations of trace elements followed the sequence of, K, Ca, Fe, Zn, Cu, Sr, Rb, Pb, but Cr, Hg and Ni were observed in one fish fram (farm A). The analysis included two tissues (flesh and gills), because most people in Sudan consume the flesh and gills, specially in the small fishes, consider as good indicators for the trace elements, and toxic compounds in general. The analysis indicated that the white nile fishes have higher l eves of most of the trace elements compared to the blue nile, e.g. Fe (560±186) in the white nile, whereas in the blue nile, (188±63). On the other hand , the artificial tilapia farms showed significant variations in the trace elements concentrations. The analysis revealed that a higher concentrations of most of the trace elements in gill tissues than flesh, e.g. Fe (1673±1453) in the flesh, and (9768±1175) in the gills. These results indicated that the gill accumulated higher levels of heavy metals than other organs, because they acted as a depot tissue. In addition, the post hoc test was performed following (Dunnett tests), using the blue nile group as a control group, since it has the lowest trace elements concentrations, among the river nile fishes in

Volatile characteristic of trace elements during microwave pyrolysis of oil shale

Energy Technology Data Exchange (ETDEWEB)

Bai, Jing-ru; Wang, Qing; Kong, Ling-wen; Bai, Zhang [Northeast Dianli Univ., Jilin (China). Engineering Research Centre

2013-07-01

Oil shale is abundant in the world. Today, the industry of oil shale retorting for producing shale oil is developing owing to high price of oil in the world. In order to study migratory behavior of trace elements in oil shale at microwave pyrolysis, tests were performed in laboratory with oil shale of the Huadian deposit of China at different powers from 400 to 700 W. The trace elements As, Cd, Hg, Mo, Pb, Se, Cr, Cu, Ni, V, Zn, Ba, Co, Mn present in oil shale and shale char were determined by the inductively coupled plasma-mass spectrometry (ICP-MS). By comparing the content of trace elements in oil shale and shale char, distribution characteristics of trace elements at retorting were studied. The overall trends of volatile ratio of trace elements are ascending with higher microwave power and higher than the conventional pyrolysis. The differences in the volatile ratio indicate that the trace elements investigated are bound with the oil shale kerogen and its mineral matter in different manner. So Float-sink experiments (FSE) were performed on oil shale. Huadian oil shale has more included mineral. The volatilization of organic matter is not the main reason for the volatilization of trace elements in oil shale. The trace elements combined with the mineral elements may be also certain volatility.

Numerical modeling of flow boiling instabilities using TRACE

International Nuclear Information System (INIS)

Kommer, Eric M.

2015-01-01

Highlights: • TRACE was used to realistically model boiling instabilities in single and parallel channel configurations. • Model parameters were chosen to exactly mimic other author’s work in order to provide for direct comparison of results. • Flow stability maps generated by the model show unstable flow at operating points similar to other authors. • The method of adjudicating when a flow is “unstable” is critical in this type of numerical study. - Abstract: Dynamic flow instabilities in two-phase systems are a vitally important area of study due to their effects on a great number of industrial applications, including heat exchangers in nuclear power plants. Several next generation nuclear reactor designs incorporate once through steam generators which will exhibit boiling flow instabilities if not properly designed or when operated outside design limits. A number of numerical thermal hydraulic codes attempt to model instabilities for initial design and for use in accident analysis. TRACE, the Nuclear Regulatory Commission’s newest thermal hydraulic code is used in this study to investigate flow instabilities in both single and dual parallel channel configurations. The model parameters are selected as to replicate other investigators’ experimental and numerical work in order to provide easy comparison. Particular attention is paid to the similarities between analysis using TRACE Version 5.0 and RELAP5/MOD3.3. Comparison of results is accomplished via flow stability maps non-dimensionalized via the phase change and subcooling numbers. Results of this study show that TRACE does indeed model two phase flow instabilities, with the transient response closely mimicking that seen in experimental studies. When compared to flow stability maps generated using RELAP, TRACE shows similar results with differences likely due to the somewhat qualitative criteria used by various authors to determine when the flow is truly unstable

Studies of effects on determination of trace hydrogen in U-Nb alloy

International Nuclear Information System (INIS)

Zou Lexi; Li Yingqiu; Liu Jun; Wu Lunqiang; Qi Lianzhu; Bian Min

2002-01-01

The affecting factors for determination of trace hydrogen in U-Nb alloy are studied. The status of samples affects greatly the measured hydrogen content, which has the higher value for scrap sample than cylinder sample. The hydrogen content in cylinder is closer to real value in U-Nb alloy. The hydrogen in U-Nb alloy is mainly from surface adsorption. The results of hydrogen determined by vacuum thermal evolved method, in which the relative standard uncertainty is less than 28%, are in agreement with those by inert-gas fusion method

Trace element analysis of old exposed air filters: a feasibility study

International Nuclear Information System (INIS)

Pattenden, N.J.; Fisher, E.M.R.; Bones, E.M.

1979-10-01

A limited number of old exposed air filters from a network of sampling stations extending the length of North and South America have been analysed for many trace elements. (The network is run by the United States Department of Energy Environmental Measurements Laboratory). The objective was to assess the possible value of a large program of such measurements for providing information on the trace element concentrations in airborne particulates existing at the time of sample collection. On the basis of the evidence obtained, it is considered that valid information could be extracted in this way. In view of the extent of the store of old filters, which cover about a 10 year period up to the present day from stations spread over the North and South American continents and elsewhere, such a program appears to be well worthwhile. (author)

Study on enhanced lymphatic tracing of isosulfan blue injection by influence of osmotic pressure on lymphatic exposure.

Science.gov (United States)

Ye, Tiantian; He, Rui; Wu, Yue; Shang, Lei; Wang, Shujun

2018-04-01

Isosulfan blue (IB) is being used as a lymphatic tracer has been approved by the FDA in 1981. This study aimed at improving lymphatic exposure of IB injection by osmotic pressure regulation to achieve step-by step lymphatic tracing. First, IB injection with appropriate osmotic pressure, stability, and suitable pH was prepared. Next, the lymphatic tracing ability of different osmotic pressure was studied to determine the blue-stained state of IB in three-level lymph nodes after subcutaneous administration. Furthermore, pharmacokinetics of lymphatic drainage, lymph node uptake, and plasma concentration was investigate to explore the improving law of the lymphatic tracing by osmotic pressure, and combined with tissue irritation to determine the optimal osmotic pressure. At last, the tissue distribution in mice of IB injection which had the property of optimal osmotic pressure was investigated. The results showed that increasing osmotic pressure could significantly reduce injection site retention and increase IB concentration of lymph node. The lymph nodes could be obviously blue-stained by IB injection which had 938 mmol/kg osmotic pressure and would not cause inflammatory reaction and blood exposure. The tissue distribution study suggested that IB injection which had 938 mmol/kg osmotic pressure was mainly distributed into gallbladder and duodenum that verified the reports that 90% IB was excreted through the feces through biliary excretion. In conclusion, this study provides the basic study to improve lymphatic exposure of IB injection by regulate the osmotic pressure and have the potential to be the helpful guidance for the elective lymph node dissection.

Trace Metals in Vegetables and Cereals- A Case Study of Indian Market-2016

Directory of Open Access Journals (Sweden)

Abaidya Nath Singh

2017-03-01

Full Text Available Background & Aims of the Study: Vegetables and Cereals are considered vital for properly-balanced diet given that they deliver vitamins, minerals, nutritional fiber, and phytochemicals. This study aimed to assess the concentration of As, Cu, Cd, Pb, Cr and Hg in common vegetables and cereals in urban open markets in Varanasi district, India Materials & Methods: Total 260 edible portions of vegetable samples of 13 species were collected in March to October, 2016 from predefined market sites. These samples classified into roots, stems, leafy vegetables, fruits, and legumes. These samples (unwashed, acetic acid washed and boiled were assessed using atomic absorption spectrophotometer. The statistical evaluations were carried out using the IBM SPSS 21. Results: The results obtained reveal that unwashed vegetables and cereals as compared to washed and boiled samples contain higher trace metal concentration. The order of heavy metal concentration was observed in Cu>Pb>Cd>As in vegetable and cereals samples. Hg and Cr were not detected in any samples. The mean value of Cu, Cd and Pb in unwashed and washed vegetables and cereals were lower than PFA standard except As, whereas in boiled vegetables and cereals are lower than PFA standard but the mean value of Cd and Pb were many folds higher than the EU standard at all the market site samples. Leafy vegetables were found to contain the highest metals values especially Spinacia oleracea followed by roots vegetable like Brassica rapa, at all the studied sites. The market sites MS3 located in the vicinity of industrial zone and in proximity to national highway showed elevated levels of trace metals concentration in the vegetables and cereals as compared to other market sites. Conclusions: The results showed that, the As, Cu, Cd and Pb concentration were reduced to about 12.5%, 5.87%, 11.36% and 10.42% of the initial concentrations by 2% acetic acid washing and to 25%, 21.87%, 20.45% and 16.67% of the initial

Nutritional values of trace elements in dried desserts

International Nuclear Information System (INIS)

Kyritsis, A.; Kanias, G.D.; Tzia, C.

1997-01-01

Desserts are the most aromatic and delicious parts of meals, and also a source of nutrient trace elements for the human body. In this work, instrumental neutron activation analysis has been applied to determine the trace elements antimony, chromium, cobalt, iron, manganese, potassium, rubidium, scandium, sodium and zinc in creme caramel, ice-creams, jellies and mousse dried desserts from the Greek market. According to our results, their classification as nutrient trace element sources for the human body is: mousse>ice-cream> creme caramel> jelly. Among the different studied flavours, chocolate and its derivatives are the richest in nutrient trace elements. Moreover, the consumption of one portion of a chocolate mousse dessert can offer to the human body about 60% of the daily required chromium, 40% of the daily required iron, 10% of the daily required manganese and potassium and 4% of the daily required sodium. (author)

Removal of trace element by isolates of Aspergillus brasiliensis ...

African Journals Online (AJOL)

Coffee beans processing generates a large volume of wastewater composed of trace elements which can be detrimental to human health. The present study aimed at evaluating the capacity of strains of Aspergillus brasiliensis and Penicillium citrinum in tolerating and removing trace elements namely: Cu, Mn and Zn from ...

Influence of trace elements in human tissue in low-energy photon brachytherapy dosimetry

International Nuclear Information System (INIS)

White, Shane A; Landry, Guillaume; Van Gils, Francis; Verhaegen, Frank; Reniers, Brigitte

2012-01-01

The aim of this paper is to determine the dosimetric impact of trace elements in human tissues for low-energy photon sources used in brachytherapy. Monte Carlo dose calculations were used to investigate the dosimetric effect of trace elements present in normal or cancerous human tissues. The effect of individual traces (atomic number Z = 11–30) was studied in soft tissue irradiated by low-energy brachytherapy sources. Three other tissue types (prostate, adipose and mammary gland) were also simulated with varying trace concentrations to quantify the contribution of each trace to the dose distribution. The dose differences between cancerous and healthy prostate tissues were calculated in single- and multi-source geometries. The presence of traces in a tissue produces a difference in the dose distribution that is dependent on Z and the concentration of the trace. Low-Z traces (Na) have a negligible effect ( 3%). There is a potentially significant difference in the dose distribution between cancerous and healthy prostate tissues (4%) and even larger if compared to the trace-free composition (15%) in both single- and multi-sourced geometries. Trace elements have a non-negligible (up to 8% in prostate D 90 ) effect on the dose in tissues irradiated with low-energy photon sources. This study underlines the need for further investigation into accurate determination of the trace composition of tissues associated with low-energy brachytherapy. Alternatively, trace elements could be incorporated as a source of uncertainty in dose calculations. (paper)

Effect of electromagnetic fields and antioxidants on the trace element content of rat teeth

Directory of Open Access Journals (Sweden)

Dogan MS

2017-05-01

Full Text Available Mehmet Sinan Dogan,1 Mehmet Cihan Yavas,2 Yasemin Yavuz,3 Sait Erdogan,4 İsmail Yener,4 İbrahim Simsek,1 Zeki Akkus,5 Veysel Eratilla,6 Abdulsamet Tanik,7 Mehmet Zulkuf Akdag2 1Department of Pediatric Dentistry, Faculty of Dentistry, Harran University, Şanliurfa, 2Department of Biophysics, Faculty of Medicine, 3Department of Restorative Dentistry, Faculty of Dentistry, 4Department of Chemistry, Faculty of Science, 5Department of Biostatistics, Faculty of Medicine, 6Department of Prosthodontics, 7Department of Periodontology, Faculty of Dentistry, Dicle University, Diyarbakir, Turkey Abstract: The purpose of this study was to examine the possible effect of extremely low-frequency electromagnetic fields (ELF-EMFs, from a high-voltage source, on rat teeth in terms of changes in trace elements (TEs and the effect of antioxidants (melatonin [MLT] and Ganoderma lucidum [GL] in counteracting these effects. We used adult male Wistar albino rats with a mean weight of 250–300 g and divided the rats into eight groups. The groups were subjected to an ELF-EMF that was applied with a high-voltage line for 8 hours/day for 26 days (Groups I, II, and III or 52 days (Groups V, VI, and VII. Groups IV and VIII were the 26- and 52-day control/sham groups, respectively. Groups II and VI were treated with GL, and Groups III and VII were treated with MLT. MLT and GL were administered daily based on the weight of the animals and appropriate standards. At the end of the study, the rats were euthanized, and their anterior teeth were extracted. The teeth were preserved in pure water before evaluating the major TEs. At the end of the study, TE concentrations (in mg/kg were assessed in the control and test groups. Compared with Group V, statistically significant differences in the concentrations of zinc (Zn and strontium (Sr were found for Group VII (ELF-EMF + MLT (P<0.05. Therefore, ELF-EMF exposure can change the content of certain TEs in teeth and, after

Three-dimensional ray-tracing model for the study of advanced refractive errors in keratoconus.

Science.gov (United States)

Schedin, Staffan; Hallberg, Per; Behndig, Anders

2016-01-20

We propose a numerical three-dimensional (3D) ray-tracing model for the analysis of advanced corneal refractive errors. The 3D modeling was based on measured corneal elevation data by means of Scheimpflug photography. A mathematical description of the measured corneal surfaces from a keratoconus (KC) patient was used for the 3D ray tracing, based on Snell's law of refraction. A model of a commercial intraocular lens (IOL) was included in the analysis. By modifying the posterior IOL surface, it was shown that the imaging quality could be significantly improved. The RMS values were reduced by approximately 50% close to the retina, both for on- and off-axis geometries. The 3D ray-tracing model can constitute a basis for simulation of customized IOLs that are able to correct the advanced, irregular refractive errors in KC.

TCP Packet Trace Analysis. M.S. Thesis

Science.gov (United States)

Shepard, Timothy J.

1991-01-01

Examination of a trace of packets collected from the network is often the only method available for diagnosing protocol performance problems in computer networks. This thesis explores the use of packet traces to diagnose performance problems of the transport protocol TCP. Unfortunately, manual examination of these traces can be so tedious that effective analysis is not possible. The primary contribution of this thesis is a graphical method of displaying the packet trace which greatly reduce, the tediousness of examining a packet trace. The graphical method is demonstrated by the examination of some packet traces of typical TCP connections. The performance of two different implementations of TCP sending data across a particular network path is compared. Traces many thousands of packets long are used to demonstrate how effectively the graphical method simplifies examination of long complicated traces. In the comparison of the two TCP implementations, the burstiness of the TCP transmitter appeared to be related to the achieved throughput. A method of quantifying this burstiness is presented and its possible relevance to understanding the performance of TCP is discussed.

Studies in China on ingestion and organ content of trace elements of importance in radiological protection. Country report

International Nuclear Information System (INIS)

Wang Jixian; Zhu Hongda; Chen Rusong

2000-01-01

In order to estimate internal dose and derive annual limits of intake for radionuclides in the field of Radiation Protection, it is necessary to study the parameters of ingestion of radionuclides from diet, deposition in tissues and following metabolism of the radionuclides. But these kinds of parameters may be influenced by intake of nutrients and inorganic constituents of diets, for example, a relatively higher uptake rate and longer retention time of radioiodine in thyroid of person who's diet poor of stable iodine. So there is a need to have accurate knowledge of corresponding stable elements intake and their concentration in organs, especially for some trace elements of importance in radiological protection such as Caesium, Iodine, Strontium, Thorium and Uranium. A IAEA RCA CRP on 'Ingestion and organ content of trace elements of importance in Radiological protection' was formulated in 1995 and initiated after the first RCM CRP on the project, held in Manila, Philippine 1-4 July 1996. This is the progress report for studies in China on ingestion and organ content of trace elements of importance in radiological protection after the first RCM

Differential accumulation of mercury and other trace metals in the food web components of a reservoir impacted by a chlor-alkali plant (Flix, Ebro River, Spain): Implications for biomonitoring

International Nuclear Information System (INIS)

Soto, David X.; Roig, Romero; Gacia, Esperanca; Catalan, Jordi

2011-01-01

Comparative studies of biomonitors of trace metal contamination are relatively scarce. We took advantage of a point source pollution in a reservoir (Flix, Spain) to compare trace metal (Hg, Pb, Cd, Se, As, Zn, Cu, Cr) bioaccumulation patterns among 16 food web components. Our results indicate that most organisms are suitable for Hg biomonitoring, whereas other metals are better monitored by only some of them. Biofilms and zebra mussel were the organisms with larger and more diverse biomonitoring capacity. However, we show that using groups of biomonitors increase the scope and strengths of the conclusions and specific goals can be better addressed. We conclude providing an overview of the strengths and weaknesses of the main organisms considered for biomonitoring trace metals in rivers and reservoirs. - Highlights: → We compare many food web components of a reservoir for trace metal bioaccumulation. → Most organisms are suitable for Hg biomonitoring. → Biofilms and zebra mussel showed more general biomonitoring capacity. → Other organisms showed strengths for specific metals or environmental compartments. → The use of a group of biomonitors increases the scope and strengths of conclusions. - The use of a group of biomonitors increases the scope and strengths of conclusions in trace metal biomonitoring.

Progress of nuclide tracing technique in the study of soil erosion in recent decade

International Nuclear Information System (INIS)

Liu Gang; Yang Mingyi; Liu Puling; Tian Junliang

2007-01-01

In the last decade nuclide tracing technique has been widely employed in the investigation of soil erosion, which makes the studies of soil erosion into a new and rapid development period. This paper tried to review the recent progress of using 137 Cs, 210 Pb ex , 7 Be, composite tracers and REE-INAA in soil erosion rate, sedimentation rate, sediment source and soil erosion processes study, and also the existing research results. The trends for future development and questions are also discussed. (authors)

Trace metal emissions from the Estonian oil shale fired power

DEFF Research Database (Denmark)

Aunela-Tapola, Leena A.; Frandsen, Flemming; Häsänen, Erkki K.

1998-01-01

Emission levels of selected trace metals from the Estonian oil shale fired power plant were studied. The plant is the largest single power plant in Estonia with an electricity production capacity of 1170 MWe (1995). Trace metals were sampled from the flue gases by a manual method incorporating...... in the flue gases of the studied oil shale plant contribute, however, to clearly higher total trace metal emission levels compared to modern coal fired power plants. Although the old electrostatic precipitators in the plant have been partly replaced by state-of-the-art electrostatic precipitators...... a two-fraction particle sampling and subsequent absorption of the gaseous fraction. The analyses were principally performed with ICP-MS techniques. The trace metal contents of Estonian oil shale were found to be in the same order of magnitude as of coal on average. The high total particle concentrations...

Classification of conductance traces with recurrent neural networks

Science.gov (United States)

Lauritzen, Kasper P.; Magyarkuti, András; Balogh, Zoltán; Halbritter, András; Solomon, Gemma C.

2018-02-01

We present a new automated method for structural classification of the traces obtained in break junction experiments. Using recurrent neural networks trained on the traces of minimal cross-sectional area in molecular dynamics simulations, we successfully separate the traces into two classes: point contact or nanowire. This is done without any assumptions about the expected features of each class. The trained neural network is applied to experimental break junction conductance traces, and it separates the classes as well as the previously used experimental methods. The effect of using partial conductance traces is explored, and we show that the method performs equally well using full or partial traces (as long as the trace just prior to breaking is included). When only the initial part of the trace is included, the results are still better than random chance. Finally, we show that the neural network classification method can be used to classify experimental conductance traces without using simulated results for training, but instead training the network on a few representative experimental traces. This offers a tool to recognize some characteristic motifs of the traces, which can be hard to find by simple data selection algorithms.

Béatrice Galinon-Mélénec (dir., L’Homme trace : perspectives anthropologiques des traces contemporaines

Directory of Open Access Journals (Sweden)

Annick Monseigne

2013-04-01

Full Text Available En première de couverture, une photographie qui a marqué un tournant dans l’histoire de l’Homme du XXème siècle : l’empreinte du premier pas d’un homme sur la Lune. Deux chapitres liminaires (pp. 15-55 où le directeur de l’ouvrage pose la question de la mise en place de traces symboliques, de la polysémie des traces, de l’absence de trace comme indice, du rôle de l’indexation pour lever la polysémie des signes et enfin de l’enjeu de la traçabilité des traces ouvrent les questions relatives ...

Australis: AMS for ultra sensitive trace element and isotopic studies

Energy Technology Data Exchange (ETDEWEB)

Sie, S H; Suter, G F [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience

1994-12-31

The accelerator mass spectrometer (AMS) at the CSIRO HIAF laboratory is being upgraded to enable in-situ measurements of ultratraces and isotopic-ratios in mineralogical applications. The upgraded system will include a microbeam Cs ion source which is designed to produce better than 50 micrometre diameter Cs beam to enable analyses of monomineralic grains. The Cs primary beam will be mass analysed in order to minimize contamination of the sample. The detection system will be upgraded to enable analyses of elements up to U, at 2 MV terminal voltage for charge states 4 and 5. The system will be known as AUSTRALIS: A.M.S. for Ultra Sensitive TRAce eLement and Isotopic Studies. An overview of the system and the anticipated applications in minerals exploration and mining research are presented. 4 refs., 1 fig.

Australis: AMS for ultra sensitive trace element and isotopic studies

International Nuclear Information System (INIS)

Sie, S.H.; Suter, G.F.

1993-01-01

The accelerator mass spectrometer (AMS) at the CSIRO HIAF laboratory is being upgraded to enable in-situ measurements of ultratraces and isotopic-ratios in mineralogical applications. The upgraded system will include a microbeam Cs ion source which is designed to produce better than 50 micrometre diameter Cs beam to enable analyses of monomineralic grains. The Cs primary beam will be mass analysed in order to minimize contamination of the sample. The detection system will be upgraded to enable analyses of elements up to U, at 2 MV terminal voltage for charge states 4 and 5. The system will be known as AUSTRALIS: A.M.S. for Ultra Sensitive TRAce eLement and Isotopic Studies. An overview of the system and the anticipated applications in minerals exploration and mining research are presented. 4 refs., 1 fig

Australis: AMS for ultra sensitive trace element and isotopic studies

Energy Technology Data Exchange (ETDEWEB)

Sie, S.H.; Suter, G.F. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience

1993-12-31

The accelerator mass spectrometer (AMS) at the CSIRO HIAF laboratory is being upgraded to enable in-situ measurements of ultratraces and isotopic-ratios in mineralogical applications. The upgraded system will include a microbeam Cs ion source which is designed to produce better than 50 micrometre diameter Cs beam to enable analyses of monomineralic grains. The Cs primary beam will be mass analysed in order to minimize contamination of the sample. The detection system will be upgraded to enable analyses of elements up to U, at 2 MV terminal voltage for charge states 4 and 5. The system will be known as AUSTRALIS: A.M.S. for Ultra Sensitive TRAce eLement and Isotopic Studies. An overview of the system and the anticipated applications in minerals exploration and mining research are presented. 4 refs., 1 fig.

Spoken word recognition without a TRACE

Science.gov (United States)

Hannagan, Thomas; Magnuson, James S.; Grainger, Jonathan

2013-01-01

How do we map the rapid input of spoken language onto phonological and lexical representations over time? Attempts at psychologically-tractable computational models of spoken word recognition tend either to ignore time or to transform the temporal input into a spatial representation. TRACE, a connectionist model with broad and deep coverage of speech perception and spoken word recognition phenomena, takes the latter approach, using exclusively time-specific units at every level of representation. TRACE reduplicates featural, phonemic, and lexical inputs at every time step in a large memory trace, with rich interconnections (excitatory forward and backward connections between levels and inhibitory links within levels). As the length of the memory trace is increased, or as the phoneme and lexical inventory of the model is increased to a realistic size, this reduplication of time- (temporal position) specific units leads to a dramatic proliferation of units and connections, begging the question of whether a more efficient approach is possible. Our starting point is the observation that models of visual object recognition—including visual word recognition—have grappled with the problem of spatial invariance, and arrived at solutions other than a fully-reduplicative strategy like that of TRACE. This inspires a new model of spoken word recognition that combines time-specific phoneme representations similar to those in TRACE with higher-level representations based on string kernels: temporally independent (time invariant) diphone and lexical units. This reduces the number of necessary units and connections by several orders of magnitude relative to TRACE. Critically, we compare the new model to TRACE on a set of key phenomena, demonstrating that the new model inherits much of the behavior of TRACE and that the drastic computational savings do not come at the cost of explanatory power. PMID:24058349

Magazines as wilderness information sources: assessing users' general wilderness knowledge and specific leave no trace knowledge

Science.gov (United States)

John J. Confer; Andrew J. Mowen; Alan K. Graefe; James D. Absher

2000-01-01

The Leave No Trace (LNT) educational program has the potential to provide wilderness users with useful minimum impact information. For LNT to be effective, managers need to understand who is most/least aware of minimum impact practices and how to expose users to LNT messages. This study examined LNT knowledge among various user groups at an Eastern wilderness area and...

The prognostic importance of smoking status at the time of acute myocardial infarction in 6676 patients. TRACE Study Group

DEFF Research Database (Denmark)

Jørgensen; Køber, L; Ottesen, M M

1999-01-01

with an infarction in order to further study the prognostic importance of smoking status at the time of myocardial infarction. The study cohort comprised 6676 patients with an enzyme-confirmed myocardial infarction admitted to 27 Danish hospitals over a 26-month period between 1990 and 1992. Smoking status......Smoking is an important risk factor for atherosclerotic heart disease, but several studies have shown smoking to be associated with a favourable prognosis in patients who have suffered an acute myocardial infarction (AMI). We studied a large group of consecutive patients admitted alive to hospital...... was determined at the time of hospitalisation and complete follow-up was obtained in October 1996. Smokers were on average 10 years younger, had fewer concomitant cardiac risk factors, and were more likely to be male and to receive thrombolytic therapy more frequently than non-smokers. In univariate analysis...

White matter integrity in kleptomania: A pilot study

Science.gov (United States)

Grant, Jon E.; Correia, Stephen; Brennan-Krohn, Thea

2007-01-01

This study's goal was to examine microstructural organization of frontal white matter in kleptomania. Ten females with DSM-IV kleptomania and 10 female controls underwent diffusion tensor imaging. Inferior frontal white matter was the a priori region of interest. Trace and fractional anisotropy (FA) were also calculated for frontal and posterior cortical regions in both subject groups. Kleptomania subjects had significantly higher mean frontal Trace, and significantly lower mean frontal FA than control subjects. Group differences remained significant when right and left frontal Trace and FA were analyzed. Groups did not differ significantly in posterior Trace or FA. Kleptomania may be associated with decreased white matter microstructural integrity in inferior frontal brain regions. PMID:16956753

A study about trace element distribution in cancer tissue and serum of cancer patients

International Nuclear Information System (INIS)

Lee, Jong In; Lee, Eun Joo; Jung, Young Joo

1993-01-01

Authers analyzed the trace element distribution of cancer tissue and its corresponding normal tissue and serum of preoperative and postoperative stage in gastric, colon, breast cancer patients. Zinc and rubidium were higher in concentration in breast cancer tissue than in normal tissue. As for the distribution of trace element in serum, bromine became about 10 times higher after gastric resection. This result can be applied to experimental carcinogenesis and to relationship with other prognostic factors. (Author)

Trace elements at the intersection of marine biological and geochemical evolution

Science.gov (United States)

Robbins, Leslie J.; Lalonde, Stefan V.; Planavsky, Noah J.; Partin, Camille A.; Reinhard, Christopher T.; Kendall, Brian; Scott, Clinton T.; Hardisty, Dalton S.; Gill, Benjamin C.; Alessi, Daniel S.; Dupont, Christopher L.; Saito, Mak A.; Crowe, Sean A.; Poulton, Simon W.; Bekker, Andrey; Lyons, Timothy W.; Konhauser, Kurt O.

2016-01-01

Life requires a wide variety of bioessential trace elements to act as structural components and reactive centers in metalloenzymes. These requirements differ between organisms and have evolved over geological time, likely guided in some part by environmental conditions. Until recently, most of what was understood regarding trace element concentrations in the Precambrian oceans was inferred by extrapolation, geochemical modeling, and/or genomic studies. However, in the past decade, the increasing availability of trace element and isotopic data for sedimentary rocks of all ages has yielded new, and potentially more direct, insights into secular changes in seawater composition – and ultimately the evolution of the marine biosphere. Compiled records of many bioessential trace elements (including Ni, Mo, P, Zn, Co, Cr, Se, and I) provide new insight into how trace element abundance in Earth's ancient oceans may have been linked to biological evolution. Several of these trace elements display redox-sensitive behavior, while others are redox-sensitive but not bioessential (e.g., Cr, U). Their temporal trends in sedimentary archives provide useful constraints on changes in atmosphere-ocean redox conditions that are linked to biological evolution, for example, the activity of oxygen-producing, photosynthetic cyanobacteria. In this review, we summarize available Precambrian trace element proxy data, and discuss how temporal trends in the seawater concentrations of specific trace elements may be linked to the evolution of both simple and complex life. We also examine several biologically relevant and/or redox-sensitive trace elements that have yet to be fully examined in the sedimentary rock record (e.g., Cu, Cd, W) and suggest several directions for future studies.

Trace elemental correlation study in malignant and normal breast tissue by PIXE technique

International Nuclear Information System (INIS)

Raju, G.J. Naga; Sarita, P.; Kumar, M. Ravi; Murty, G.A.V. Ramana; Reddy, B. Seetharami; Lakshminarayana, S.; Vijayan, V.; Lakshmi, P.V.B. Rama; Gavarasana, Satyanarayana; Reddy, S. Bhuloka

2006-01-01

Particle induced X-ray emission technique was used to study the variations in trace elemental concentrations between normal and malignant human breast tissue specimens and to understand the effects of altered homeostasis of these elements in the etiology of breast cancer. A 3 MeV proton beam was used to excite the biological samples of normal and malignant breast tissues. The elements Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Rb and Sr were identified and their relative concentrations were estimated. Almost all the elements were found to be elevated (p < 0.05, Wilcoxon signed-ranks test) in the cancerous tissues when compared with normal tissues. The excess levels of trace elements observed in the cancerous breast tissues could either be a cause or a consequence of breast cancer. Regarding their role in the initiation or promotion of breast cancer, one possible interpretation is that the elevated levels of Cu, Fe and Cr could have led to the formation of free radicals or other reactive oxygen species (ROS) that adversely affect DNA thereby causing breast cancer, which is mainly attributed to genetic abnormalities. Moreover, since Cu and Fe are required for angiogenesis, elevated concentrations of these elements are likely to promote breast cancer by increasing the blood supply for tumor growth. On the other hand elevated concentrations of elements in breast cancer tissues might also be a consequence of the cancer. This can be understood in terms of the biochemical and histological differences between normal and cancerous breast tissues. Tumors, characterized by unregulated multiplication of cells, need an ever-increasing supply of essential nutrients including trace elements. This probably results in an increased vascularity of malignant tissues, which in turn leads to enhancement of elemental concentrations in tumors

Uptakes of trace elements in Zn-deficient mice

International Nuclear Information System (INIS)

Ohyama, T.; Yanaga, M.; Yoshida, T.; Maetsu, H.; Suganuma, H.; Omori, T.

2002-01-01

A multitracer technique was used to obtain uptake rates of essential trace elements in various organs and tissues in Zn-deficient mice. A multitracer solution, containing more than 20 radioisotopes, was injected intraperitoneally into Zn-deficient state mice and control ones. Uptake rates of the radioisotopes were compared with concentrations of trace elements determined by instrumental neutron activation analysis (INAA) in order to study a specific metabolism of Zn and other essential trace elements, such as Mn, Co, Se, Rb, and Sr. The result suggests that Zn is supplied from bone to other organs and tissues and an increase in Co concentration in all organs and tissues depends on its chemical form, under the Z-deficient state. (author)

Computer program for optical systems ray tracing

Science.gov (United States)

Ferguson, T. J.; Konn, H.

1967-01-01

Program traces rays of light through optical systems consisting of up to 65 different optical surfaces and computes the aberrations. For design purposes, paraxial tracings with astigmation and third order tracings are provided.

Research on Pin Tumbler Locks and the Characteristics of Surface Traces Formed by Unlocking Guns

Science.gov (United States)

Yi, Gao; Yifeng, Jin; Yanping, Bai; Hongcheng, Mei; Zhen, Xu

2018-02-01

In this paper, taking the structure of the pin tumbler locks and the principle of opening and closing locks as breakthrough point, we have studied the machining traces of pin tumbler components and trace characters of pin surface during normal operating. At the same time, taking the unlocking gun as an example, the paper analyzes the unlocking technology and the formation of traces, and summarizes the changing rules of the surface traces of elastic bead locks by comparing the positions and the characteristics of the traces, which provides technical support for the future study of traces of pin tumbler locks.

The group-as-a-whole-object relations model of group psychotherapy.

Science.gov (United States)

Rosen, D; Stukenberg, K W; Saeks, S

2001-01-01

The authors review the theoretical basis of group psychotherapy performed at The Menninger Clinic and demonstrate how the theory has been put into practice on two different types of inpatient units. The fundamental elements of the theory and practice used can be traced to object relations theory as originally proposed by Melanie Klein. Her work with individuals was directly applied to working with groups by Ezriel and Bion, who focused on interpreting group tension. More modern approaches have reintegrated working with individual concerns while also attending to the group-as-a-whole. Historically, these principles have been applied to long-term group treatment. The authors apply the concepts from the group-as-a-whole literature to short- and medium-length inpatient groups with open membership. They offer clinical examples of the application of these principles in short-term inpatient settings in groups with open membership.

Linac particle tracing simulations

International Nuclear Information System (INIS)

Lysenko, W.P.

1979-01-01

A particle tracing code was developed to study space--charge effects in proton or heavy-ion linear accelerators. The purpose is to study space--charge phenomena as directly as possible without the complications of many accelerator details. Thus, the accelerator is represented simply by harmonic oscillator or impulse restoring forces. Variable parameters as well as mismatched phase--space distributions were studied. This study represents the initial search for those features of the accelerator or of the phase--space distribution that lead to emittance growth

Effect of angiotensin converting enzyme inhibition after acute myocardial infarction in patients with arterial hypertension. TRACE Study Group, Trandolapril Cardiac Event

DEFF Research Database (Denmark)

Gustafsson, F; Torp-Pedersen, C; Køber, L

1997-01-01

patients who entered the study, 400 (23%) had a history of arterial hypertension. The mean follow-up time was 26 months. MAIN OUTCOME MEASURES: Mortality from any cause. Secondary endpoints were sudden death, cardiovascular mortality, reinfarction and development of severe heart failure. RESULTS......OBJECTIVE: To evaluate the influence of a history of arterial hypertension on the efficacy of the angiotensin converting enzyme (ACE) inhibitor trandolapril in patients with acute myocardial infarction (AMI) and left ventricular dysfunction. METHODS: A retrospective analysis of data from......: Of the patients in the hypertensive group, 173 (43%) died during follow-up, versus 500 (37%) in the normotensive group. Treatment with trandolapril resulted in a relative risk of death from any cause for the hypertensive group of 0.59 (96% confidence interval 0.44-0.80), versus 0.85 (0.72-1.02) for normotensive...

Plasma trace metals during total parenteral alimentation.

Science.gov (United States)

Solomons, N W; Layden, T J; Rosenberg, I H; Vo-Khactu, K; Sandstead, H H

1976-06-01

The plasma concentrations of the trace metals zinc and copper were studied prospectively in 13 patients with gastrointestinal diseases treated with parenteral alimentation (TPA) for periods of from 8 days to 7 1/2 weeks. Plasma copper levels fell rapidly and consistently in all patients, with an overall rate of - 11 mug per 100 ml per week. Zinc concentrations declined in 10 of 13 patients at a more gradual rate. Analysis of the standard parenteral alimentation fluids revealed zinc content equivalent to 50% of the daily requirement and a negligible content of copper. From combined analysis of plasma zinc, hair zinc, and taste acuity, there is evidence that increased utilization or redistribution within the body may effect plasma concentrations in some patients. Neither an increase in urinary excretion nor a primary decrease in plasma binding proteins appeared to be a major factor in lowering plasma trace metal concentrations. These findings indicate that a marked decrease in plasma copper is regular and a decline in plasma zinc is common during TPA using fluids unsupplemented with trace metals. Supplementation of parenteral alimentation fluids with the trace metals zinc and copper is recommended.

Trace and axial anomalies in dimensional renormalization through Zimmermann-like identities

International Nuclear Information System (INIS)

Bonneau, G.

1980-01-01

The problem of anomalies is solved in dimensional renormalization in two steps. Firstly one shows that trace and γ 5 anomalies can be expressed as the anomalous normal product N[gsub(μ rho)Osub(μ rho lambda)...(x)] where gsub(μ rho) is the metric tensor in D-4 dimensions (D being the space-time dimension) and Osub(μ rho lambda)...(x) a monomial in the fields and their derivatives. Then, with techniques similar to those used in a previous work to study N[(4-D)Osub(μ rho lambda)(x)], we prove a Zimmermann-like identity that gives the decomposition of such anomalous normal product on 'usual' normal products, the coefficients being explicitly given as residues of the simple pole in v = 4-D of definite proper Green functions where the overall subtraction has not been done. We apply the above formalism to obtain the renormalization group as a consequence of trace anomalies in the dilatation current and to derive the Adler-Bardeen theorem for massive QED. (orig.)

Trace elements content of sudanese local snuff and its agricultural soil

International Nuclear Information System (INIS)

Hassan, R. E.; Eltayeb, M. A.

2003-01-01

Toombak is a local form of snuff widely used in Sudan. Dipping snuff is a common habit in Sudanese male subject. Many reports have related at the high incidence rate of oral cancer and other types of cancer in Sudanese subjects to this habit. trace elements such as Cu, Co, Cd, Cr, Fe, Mn, Pb, and Zn were measured using atomic absorption spectrometry in soil on which toombak is grown and toombak eaves. The average concentration (μg/g) of these elements in soil and toombak leaves were found to be 60.8 and 18.1 (Cu), 72.2 and 50.9 (Zn), 48.4 and 19.9 (Co), 398.6 and 211.7 (Mn), 17391.9 and 6410.7 (Fe), 16.1 and 5.3 (Cr), 27.7 and 7.9 (Pb), 7.2 and 4.8 (Cd), respectively. Soil to plant transfer factor was determined and found to be less than unity. The correlation coefficient between concentrations of trace elements in soils, and their soil-to-toombak transfer factors divided the elements into two groups, first group have inverse correlation while the second group is independent of their soil concentration. (Author)

Trace element deficiency and its diagnosis by radioisotope injection

International Nuclear Information System (INIS)

Kirchgessner, M.; Schwarz, F.J.

1976-01-01

The metabolism of trace elements is subject to certain mechanisms of homeostatic regulation. The supply status of the trace elements, iron, copper, zinc and manganese has definite effects on their respective extent of intestinal absorption, retention and intestinal excretion. Experimental studies show that there is an increase in intestinal absorption and retention, and a decrease in turnover rate and endogenous excretion of these trace elements in response to deficient dietary intake. On the basis of these results, three models are discussed for the use of radioisotopes in the diagnosis of situations of trace element deficiency: (1) Determination of the intestinal absorption of an orally administered radioisotope dose by measuring the activity of blood; (2) Determination of the retention of a parenterally administered dose in blood or plasma; and (3) Determination of the endogenous faecal excretion of a parenterally administered dose. The advantages and disadvantages of these models are discussed. Determination of the endogenous secretion of the trace element after intravenous injection of its radioisotope may be considered as the simplest and most informative method. (author)

Tracing sediment sources in Royal Drainage basin, Iran

International Nuclear Information System (INIS)

Feiznia, S.; Kouhpelma, A.; Ahmadi, H.; Hashemi, S. A.

2009-01-01

For successful soil conservation measures, obtaining information about the relative importance of sediment source and their shares in sediment production is required. Tracing or source studies are emphasized in recent years due to their privileges. In this research, sediment sources were identified using tracing method. A small earth dam is constructed at the outlet of Royan Drainage Basin in 1993. In this study, sediments were sampled from dam reservoir, different sources were also sampled. The results of this research can be used in soil conservation projects for execution of suitable management strategies. (Author) 6 refs.

Tracing sediment sources in Royal Drainage basin, Iran

Energy Technology Data Exchange (ETDEWEB)

Feiznia, S.; Kouhpelma, A.; Ahmadi, H.; Hashemi, S. A.

2009-07-01

For successful soil conservation measures, obtaining information about the relative importance of sediment source and their shares in sediment production is required. Tracing or source studies are emphasized in recent years due to their privileges. In this research, sediment sources were identified using tracing method. A small earth dam is constructed at the outlet of Royan Drainage Basin in 1993. In this study, sediments were sampled from dam reservoir, different sources were also sampled. The results of this research can be used in soil conservation projects for execution of suitable management strategies. (Author) 6 refs.

Trace elements in precious and common opals using neutron activation analysis

International Nuclear Information System (INIS)

McOrist, G.D.; Smallwood, A.

1997-01-01

Neutron activation analysis (NAA) was used to determine the concentration of trace elements in 44 precious and 52 common opals sampled from a number of recognised fields within Australia. The purpose of this study was to determine if precious and common opals of the same colour and location have the same or a different trace element profile. Similar numbers of black, white and grey samples were studied in each case. In most cases, common opals had a significantly higher concentration of certain trace elements when compared with precious opals. (author)

Offset Trace-Based Video Quality Evaluation Network Transport

DEFF Research Database (Denmark)

Seeling, P.; Reisslein, M.; Fitzek, Frank

2006-01-01

Video traces contain information about encoded video frames, such as frame sizes and qualities, and provide a convenient method to conduct multimedia networking research. Although wiedely used in networking research, these traces do not allow to determine the video qaulityin an accurate manner...... after networking transport that includes losses and delays. In this work, we provide (i) an overview of frame dependencies that have to be taken into consideration when working with video traces, (ii) an algorithmic approach to combine traditional video traces and offset distortion traces to determine...... the video quality or distortion after lossy network transport, (iii) offset distortion and quality characteristics and (iv) the offset distortion trace format and tools to create offset distortion traces....

Contents of trace elements in blood of healthy old people assayed by ICP-MS

International Nuclear Information System (INIS)

Wen Xinyu; Tong Hongli; Wang Ling; Zhou Heping; Tian Yaping

2008-01-01

To investigate the levels of 11 trace elements in serum of healthy old people to provide scientific basis for prevention and treatment of geriatric diseases, the serum were separated from blood samples according to standard procedure. The serum samples were underwent digestion, elimination of nitric acid, volume fixation and then assayed by inductively coupled plasma mass spectrometry. The results showed that the contents of Al in elderly people's serum is higher than those in young people (P<0.01), while the contents of V, Cr, Cu and Se in elderly people's serum were lower than those in young people (P<0.05). There were no significant differences in other trace elements between two groups. The contents of some trace elements in elderly people's serum changed significantly. (authors)

Study of the extraction of the traces of Cadmium through the method of subestequiometric isotope dilution

International Nuclear Information System (INIS)

Garate V, Z.

1990-01-01

In this work, it has been used the method of subestequiometric isotope dilution for the determination of traces of cadmium and it has been compared with other conventional's methods for study its performance. The conditions of the experiment had been studied carefully in order to optimize the parameters such as pH, (8,0 - 10,1) it used the buffer NH 3 :NH 4 Cl, the time of agitation (>120 s) and the concentration of the organic reactive (dithizone). Besides, it obtains the respective curve of calibration. In this study, we can watch a line relation in all the range studied (5-40 μg of Cd). This method applied to the analysis of Cadmium in a certified sample of H-8 of the IAEA, it gives us the next value: 195 ± 5,4 ppm (LOD= 1,5 ppm, LOQ= 4,8 ppm), it is enough satisfactory in comparison with the certified middle value of 188,9±19 ppm. It demonstrates the utility of the method in the Cadmium traces analysis if it disposes of the radioisotope of this element and the appropriate detection equipment. (DEM). 34 refs., 15 tabs., 7 figs

Studies in China on ingestion and organ content of trace elements of importance in radiological protection

International Nuclear Information System (INIS)

Wang Jixian; Zhu Hongda; Chen Rusong

1998-01-01

In order to ensure the representative sampling for ingestion study a sampling strategy that took account of all relevant ethnic, socioeconomic and geographic variables was devised by the Institute of Nutrition and Food Hygiene, CAPM for the first total diet study in China. Total diet samples was prepared as 'market basket' samples. Based on the information of food consumption, composition and cookery obtained by the diet consumption survey, the 12 categories of food were collected from nearby markets and cooked by local cookery. For investigation the relationship between elements intake and organ content the specimens for organ content study will be collected from the subjects of sudden death inhabited in the region where the diet samples to be collected for ingestion study. The analytical technique that will be used to determine trace elements of interest in specimens of diet and organs have been proposed, for I that is ENAA, for Cs and Sr that is FAAS or ICP-MS, and for U and Th that is ICP-MS. At last the report summarized the information on trace element content of drinking water supplies in China. (author)

Leveraging First Response Time into the Knowledge Tracing Model

Science.gov (United States)

Wang, Yutao; Heffernan, Neil T.

2012-01-01

The field of educational data mining has been using the Knowledge Tracing model, which only look at the correctness of student first response, for tracking student knowledge. Recently, lots of other features are studied to extend the Knowledge Tracing model to better model student knowledge. The goal of this paper is to analyze whether or not the…

Application of trace element analysis to determine trace element concentrations in the field of medicine

International Nuclear Information System (INIS)

Kasperek, K.; Feinendegen, L.E.

1976-01-01

Applied trace elements research in medicine requires a sensitive and efficient technique of trace elements analysis such as, e.g., neutron activation analysis. Essential trace elements act as stabilisators (iron in haem), structural elements (silicium in fibrous tissue), in hormones (iodine in thyroid hormone), in vitamins (cobalt in vitamin B 12), and in enzymes. Most of the essential trace elements act as coenzymes or in coenzymes or directly as metabolic catalysators. For example, selenium deficiency in PKU and maple syrup patients receiving dietary treatment can be detected by determining the selenium content of the serum, while low selenium values in the whole blood indicate liver cirrhosis. Acrodermatitis enteropathica can be diagnosed by determinig zinc in the serum, and pancreatic insufficiency by determining zinc in the pancreatic juice. Zinc also plays a part in disturbances of growth, in the healing of wounds, and in the insulin metabolism. Cobalt is important in some types of anaemia and in myocardiopathies. Trace elements are also necessary in the treatment of diseases, e.g. iron cobalt in some types of anaemia, and zinc in the delayed healing of wounds in the postoperative phase and in acrodermatitis enteropathica. Chromium is now being tested for the treatment of diabetes mellitus, and fluorides may be of interest in the treatment of osteoporosis. Finally, trace elements are important in the aetiology of acute poisoning, in nutrition, and in environmental protection. (orig./AK) [de

Factors influencing health care workers’ implementation of tuberculosis contact tracing in Kweneng, Botswana

Science.gov (United States)

Tlale, Lebapotswe; Frasso, Rosemary; Kgosiesele, Onalenna; Selemogo, Mpho; Mothei, Quirk; Habte, Dereje; Steenhoff, Andrew

2016-01-01

Introduction TB contact tracing rates remain low in high burden settings and reasons for this are not well known. We describe factors that influence health care workers' (HCW) implementation of TB contact tracing (CT) in a high TB burden district of Botswana. Methods Data were collected using questionnaires and in-depth interviews in 31 of the 52 health facilities in Kweneng East Health District. Responses were summarized using summary statistics and comparisons between HCW groups were done using parametric or non-parametric tests as per normality of the data distribution. Results One hundred and four HCWs completed questionnaires. Factors that influenced HCW TB contact tracing were their knowledge, attitudes and practices as well as personal factors including decreased motivation and lack of commitment. Patient factors included living further away from the clinic, unknown residential address and high rates of migration and mobility. Administrative factors included staff shortages, lack of transport, poor reporting of TB cases and poor medical infrastructure e.g. suboptimal laboratory services. A national HCW strike and a restructuring of the health system emerged as additional factors during in-depth interviews of TB coordinators. Conclusion Multiple factors lead to poor TB contact tracing in this district. Interventions to increase TB contact tracing will be informed by these findings. PMID:27800084

Investigation of selected trace elements in hair samples of eczema patients

International Nuclear Information System (INIS)

Osman, N. O.

2010-12-01

The aim of this case-control study was to investigate the relationship between selected trace elements and skin diseases, namely eczema. Fifty five patients affected by the most frequent eczema types were recruited at the onset of disease at the hospital of dermatology in Khartoum together with thirty healthy controls. Fe, Zn, Cu, and Ni were measured in hair samples obtained from both patients and control group using Atomic Absorption Spectrometry (AAS). Data analysis was performed using the T-test. Partial correlation was used to study the relationship between the elemental concentration. Certified reference material (IAEA-85) Hair Powder) produced by the International Atomic Energy Agency (IAEA) was used as a quality control to check the accuracy and precision of the analytical technique, good agreement was achieved for all elements under investigation. Significant variations (p<0.05) in the concentrations of Fe, Zn, Cu, and Ni in the hair of the patients compared to the control group, and this difference was a decrease of iron, zinc and copper, therefore, should be given to the patient doses of these elements, while there was an increase in the nickel. So it is not included in the treatment. These interesting associations between the levels the of trace elements could be used as an indication for the disease as well as to monitor the treatment. Comparisons of the results obtained in the present study with those conducted for other population in the literature showed very close agreement. The levels of the elements under investigation are comparable with the data obtained from the literature for other populations with exception of Fe which was found to be very high in Sudanese population. (Author)

Investigation of selected trace elements in hair samples of eczema patients

Energy Technology Data Exchange (ETDEWEB)

Osman, N O [Atomic Energy Council, Sudan Academy of Sciences (SAS), Khartoum (Sudan)

2010-12-15

The aim of this case-control study was to investigate the relationship between selected trace elements and skin diseases, namely eczema. Fifty five patients affected by the most frequent eczema types were recruited at the onset of disease at the hospital of dermatology in Khartoum together with thirty healthy controls. Fe, Zn, Cu, and Ni were measured in hair samples obtained from both patients and control group using Atomic Absorption Spectrometry (AAS). Data analysis was performed using the T-test. Partial correlation was used to study the relationship between the elemental concentration. Certified reference material (IAEA-85) Hair Powder) produced by the International Atomic Energy Agency (IAEA) was used as a quality control to check the accuracy and precision of the analytical technique, good agreement was achieved for all elements under investigation. Significant variations (p<0.05) in the concentrations of Fe, Zn, Cu, and Ni in the hair of the patients compared to the control group, and this difference was a decrease of iron, zinc and copper, therefore, should be given to the patient doses of these elements, while there was an increase in the nickel. So it is not included in the treatment. These interesting associations between the levels the of trace elements could be used as an indication for the disease as well as to monitor the treatment. Comparisons of the results obtained in the present study with those conducted for other population in the literature showed very close agreement. The levels of the elements under investigation are comparable with the data obtained from the literature for other populations with exception of Fe which was found to be very high in Sudanese population. (Author)

The Y-chromosome haplogroup C3*-F3918, likely attributed to the Mongol Empire, can be traced to a 2500-year-old nomadic group.

Science.gov (United States)

Zhang, Ye; Wu, Xiyan; Li, Jiawei; Li, Hongjie; Zhao, Yongbin; Zhou, Hui

2018-02-01

The Mongol Empire had a significant role in shaping the landscape of modern populations. Many populations living in Eurasia may have been the product of population mixture between ancient Mongolians and natives following the expansion of Mongol Empire. Geneticists have found that most of these populations carried the Y-haplogroup C3* (C-M217). To trace the history of haplogroup (Hg) C3* and to further understand the origin and development of Mongolians, ancient human remains from the Jinggouzi, Chenwugou and Gangga archaeological sites, which belonged to the Donghu, Xianbei and Shiwei, respectively, were analysed. Our results show that nine of the eleven males of the Gangga site, two of the eight males of Chengwugou site and all of the twelve males of Jinggouzi site were found to have mutations at M130 (Hg C), M217 (Hg C3), L1373 (C2b, ISOGG2015), with the absence of mutations at M93 (Hg C3a), P39 (Hg C3b), M48 (Hg C3c), M407 (Hg C3d) and P62 (Hg C3f). These samples were attributed to the Y-chromosome Hg C3* (Hg C2b, ISOGG2015), and most of them were further typed as Hg C2b1a based on the mutation at F3918. Finally, we inferred that the Y-chromosome Hg C3*-F3918 can trace its origins to the Donghu ancient nomadic group.

Diagnosing MOV problems using comparative trace analysis

International Nuclear Information System (INIS)

Leon, R.L.

1992-01-01

The paper presents the concept of comparative trace analysis and shows it to be very effective in diagnosing motor operated valve (MOV) problems. Comparative trace analysis is simply the process of interpreting simultaneously gathered traces, each presenting a different perspective on the same series of events. The opening and closing of a motor operated valve is such a series of events. The simultaneous traces are obtained using Liberty Technologies' Valve Operation Test and Evaluation System (VOTES)reg-sign. The traces include stem thrust, motor current, motor power factor, motor power, switch actuations, vibration in three different frequency bands, spring pack displacement, and spring pack force. Spare and auxiliary channels enable additional key parameters to be measured, such as differential pressure and stem displacement. Though not specifically illustrated in this paper, the VOTES system also provides for FFT analysis on all traces except switches

Predicting Individual Characteristics from Digital Traces on Social Media: A Meta-Analysis.

Science.gov (United States)

Settanni, Michele; Azucar, Danny; Marengo, Davide

2018-04-01

The increasing utilization of social media provides a vast and new source of user-generated ecological data (digital traces), which can be automatically collected for research purposes. The availability of these data sets, combined with the convergence between social and computer sciences, has led researchers to develop automated methods to extract digital traces from social media and use them to predict individual psychological characteristics and behaviors. In this article, we reviewed the literature on this topic and conducted a series of meta-analyses to determine the strength of associations between digital traces and specific individual characteristics; personality, psychological well-being, and intelligence. Potential moderator effects were analyzed with respect to type of social media platform, type of digital traces examined, and study quality. Our findings indicate that digital traces from social media can be studied to assess and predict theoretically distant psychosocial characteristics with remarkable accuracy. Analysis of moderators indicated that the collection of specific types of information (i.e., user demographics), and the inclusion of different types of digital traces, could help improve the accuracy of predictions.

Trace metals in heavy crude oils and tar sand bitumens

Energy Technology Data Exchange (ETDEWEB)

Reynolds, J.G.

1990-11-28

Fe, Ni, and V are considered trace impurities in heavy crude oils and tar sand bitumens. In order to understand the importance of these metals, we have examined several properties: (1) bulk metals levels, (2) distribution in separated fractions, (3) size behavior in feeds and during processing, (4) speciation as a function of size, and (5) correlations with rheological properties. Some of the results of these studies show: (1) V and Ni have roughly bimodal size distributions, (2) groupings were seen based on location, size distribution, and Ni/V ratio of the sample, (3) Fe profiles are distinctively different, having a unimodal distribution with a maximum at relatively large molecular size, (4) Fe concentrations in the tar sand bitumens suggest possible fines solubilization in some cases, (5) SARA separated fractions show possible correlations of metals with asphaltene properties suggesting secondary and tertiary structure interactions, and (6) ICP-MS examination for soluble ultra-trace metal impurities show the possibility of unexpected elements such as U, Th, Mo, and others at concentrations in the ppB to ppM range. 39 refs., 13 figs., 5 tabs.

Trace maps of general substitutional sequences

International Nuclear Information System (INIS)

Kolar, M.; Nori, F.

1990-01-01

It is shown that for arbitrary n, there exists a trace map for any n-letter substitutional sequence. Trace maps are explicitly obtained for the well-known circle and Rudin-Shapiro sequences which can be defined by means of substitution rules on three and four letters, respectively. The properties of the two trace maps and their consequences for various spectral properties are briefly discussed

Comparison of ADC map with trace map in the normal and infarct areas of the brains of stroke patients

International Nuclear Information System (INIS)

Kim, Seung Hyung; Yoon, Pyeong Ho; Jeong, Eun Kee; Oh, Young Taick; Kim, Dong Ik

1999-01-01

To compare ADC mapping with trace mapping in normal and infarct areas of the brains of stroke patients. Eighteen patients diagnosed on the basis of clinical and brain MRI examinations as suffering from brain infarction were included in this study (hyperacute-1, acute-4, subacute-12, chronic-1). Diffusion weighted images of three orthogonal directions of a patient's brain were obtained by means of a single shot EPI pulse sequence, using a diffusion gradient with four serial b-factors. Three ADC maps were then reconstructed by post-image processing and were summed pixel by pixel to yield a trace map. ROIs were selected in the normal areas of white matter, gray matter and CSF of one hemisphere, and other ROIs of the same size were selected at the same site of the contralateral hemisphere. ADC and trace values were measured and right/left ratios of ADC and trace values were calculated. Using these values, we then compared the ADC map with the trace map, and compared the degree of anisotropic diffusion between white matter, gray matter and CSF. Except for three, whose infarct lesions were small and lay over white and gray matter, patients were divided into two groups. Those with infarct in the white matter (n=10) were assigned to one group, and those with infarct in the gray matter (n=5) to the other. ROIs were selected in the infarct area and other ROIs of the same size were selected at the same site of the contralateral hemisphere. ADC and trace values were measured and infarct/contralateral ratios were calculated. We then compared ADC ratio with trace ratio in white matter and gray matter infarct. In normal white matter, the Dxx ratio was 0.980±0.098, the Dyy ratio 1.019±0.086, the Dzz ratio 0.999±0.111, and the trace ratio 0.995±0.031. In normal gray matter, the Dxx ratio was 1.001±0.058, the Dyy ratio 0.996±0.063, Dzz ratio 1.005±0.070, and the trace ratio 1.001±0.028. In CSF, the Dxx ratio was 1.002±0.064, the Dyy ratio 1.023±0.055, the Dzz ratio 0.999�

Separation of Trace Amount Zn (II Using Additional Carbonyl and Carboxyl Groups Functionalized-Nano Graphene

Directory of Open Access Journals (Sweden)

A. Moghimi

2013-01-01

Full Text Available A novel and selective method for the fast determination of trace amounts of Zn(IIions in water samples has been developed.  The first additional carbonyl and carboxyl functionalized-nano graphene (SPFNano graphene. The presence of additional carbonyl and carboxyl groups located at the edge of the sheets makes GO sheets strongly hydrophilic, allowing them to readily swell and disperse in water. Based on these oxygen functionalities, different model structures of GO were used as absorbent for extraction of Zn (II   ions by solid phase extraction method. The complexes were eluted with HNO3 (2M10% V.V-1 methanol in acetone and determined the analyte by flame atomic absorption spectrometry.  The procedure is based on the selective formation of Zn (II at optimum pH by elution with organic eluents and determination by flame atomic absorption spectrometry. The method is based on complex formation on the surface of the ENVI-18 DISKTM disks modified carbonyl and carboxyl functionalized-nano graphene oxide molecules covalently bonded together followed by stripping of the retained species by minimum amounts of appropriate organic solvents. The elution is efficient and quantitative. The effect of potential interfering ions, pH, SPFNano graphene, amount, stripping solvent, and sample flow rate were also investigated. Under the optimal experimental conditions, the break-through volume was found to about 1000mL providing a preconcentration factor of 500. The maximum capacity of the disks was found to be 456± 3 µg for Zn2+.The limit of detection of the proposed method is 5ng per 1000mL.The method was applied to the extraction and recovery of Zn in different water samples.

Brain trace elements and aging

International Nuclear Information System (INIS)

Hebbrecht, Geert; Maenhaut, Willy; Reuck, Jacques de

1999-01-01

Degenerative mechanisms involved in the aging process of the brain are to a certain extent counteracted by repair mechanisms. In both degenerative and recovery processes, trace elements are involved. The present study focused on the role of two minor (i.e., K and Ca) and six trace elements (i.e., Mn, Fe, Cu, Zn, Se and Rb) in the aging process. The elements were determined by PIXE in cerebral cortex and white matter, basal ganglia, brainstem and cerebellar cortex of 18 postmortem human brains, from persons without a history of neurologic or psychiatric disease who deceased between the age of 7 and 79. This age range allowed us to study the relationship between elemental concentrations and age. The most prominent findings were a concentration decrease for K and Rb and a concentration increase for the elements Ca, Fe, Zn and Se. The study supports recent findings that Ca and Fe are involved in brain degenerative processes initiated by oxygen free radicals, whereas Zn and Se are involved in immunological reactions counteracting the aging process

SRXRF study of trace elements in hippocampus of pup rats after prenatal and postnatal exposure to low-level mercury

International Nuclear Information System (INIS)

Zhang Fang; Feng Weiyue; Chai Zhifang; Wang Meng; Shi Junwen; Huang Yuying; He Wei

2005-01-01

Since the pollution of mercury in the environment still keeps high, more and more concerns over mercury toxicity are focused on the potential risk associated with relatively low-dose and long-term mercury exposure in the environment. It is well known that fetus and developing children are the susceptive victims of mercury damage. Therefore, high attention is focused on whether the prenatal and postnatal exposure to relatively low level of mercury will be harmful to children development. Some epidemiological studies reported that the methylmercury-related neuropsychological deficits were mainly found in the domains of cognitional parts, such as language, attention, memory, and so forth, Our previous study found out that high level of mercury was accumulated in the pup hippocampus after their prenatal and postnatal exposure to low dose of inorganic mercury. Synchrotron radiation X-ray fluorescence technique (SRXRF) is characterized of its simultaneous determination of multi-elements, high sensitivity, small sampling amount and microanalysis. SRXRF does not cause the damage of irradiated samples. Thus, it makes possible to measure the distributions of trace elements in a selected area. In this study, in order to study the effects of low-level mercury exposure to pup rat brain, some oxidation-related elements, e.g. Cu, Fe and Mn in pup hippocampus after in utero and weaning exposure to low-level inorganic mercury were determined by SRXRF. The experiment was performed at a synchrotron radiation facility at Institute of High Energy Physics. And the spot size of the beam irradiating on the sample was adjusted to about 100 x 200 μm 2 , Each spot was irradiated for about 100 s. The spectra were analyzed by the AXIL program. Additionally, the activities of some important antioxidant enzymes, such as GSH-Px, SOD, CAT, were also measured together with the content of malondialdehyde (MDA). The results showed that mercury exposure could lead to significant increase of both

Relationship between epiphytic lichens, trace elements and gaseous atmospheric pollutants

NARCIS (Netherlands)

Dobben, van H.F.; Wamelink, G.W.W.; Braak, ter C.J.F.

2001-01-01

A study was conducted to determine the joint effect of gaseous atmospheric pollutants and trace elements on epiphytic lichens. We used our data to test the hypothesis that lichens are generally insensitive to toxic effects of trace elements, and can therefore be used as accumulator organisms to

Repetition suppression and repetition enhancement underlie auditory memory-trace formation in the human brain: an MEG study.

Science.gov (United States)

Recasens, Marc; Leung, Sumie; Grimm, Sabine; Nowak, Rafal; Escera, Carles

2015-03-01

The formation of echoic memory traces has traditionally been inferred from the enhanced responses to its deviations. The mismatch negativity (MMN), an auditory event-related potential (ERP) elicited between 100 and 250ms after sound deviation is an indirect index of regularity encoding that reflects a memory-based comparison process. Recently, repetition positivity (RP) has been described as a candidate ERP correlate of direct memory trace formation. RP consists of repetition suppression and enhancement effects occurring in different auditory components between 50 and 250ms after sound onset. However, the neuronal generators engaged in the encoding of repeated stimulus features have received little interest. This study intends to investigate the neuronal sources underlying the formation and strengthening of new memory traces by employing a roving-standard paradigm, where trains of different frequencies and different lengths are presented randomly. Source generators of repetition enhanced (RE) and suppressed (RS) activity were modeled using magnetoencephalography (MEG) in healthy subjects. Our results show that, in line with RP findings, N1m (~95-150ms) activity is suppressed with stimulus repetition. In addition, we observed the emergence of a sustained field (~230-270ms) that showed RE. Source analysis revealed neuronal generators of RS and RE located in both auditory and non-auditory areas, like the medial parietal cortex and frontal areas. The different timing and location of neural generators involved in RS and RE points to the existence of functionally separated mechanisms devoted to acoustic memory-trace formation in different auditory processing stages of the human brain. Copyright © 2014 Elsevier Inc. All rights reserved.

Addictive drugs and their duration affecting on trace elements levels in men

International Nuclear Information System (INIS)

Nadeem, A.; Iqbal, K.; Shafiq, T.; Rehman, S.

2008-01-01

During the drug addiction the blood biochemistry particularly level of trace elements in blood is widely affected. Eighty male addicts of various age groups along with seventeen normal subjects were studied. The plasma Zinc and manganese concentration was high in addict person as compared to normal subjects. Where as a significant decrease in iron concentration was observed in addicts. The plasma copper concentration was also low in addicts as compared to normal subjects. In conclusion drug addiction leads to many biochemical changes that may have detritus effects on health status of addicts. (author)

The bark of the branches of holm oak (Quercus ilex L.) for a retrospective study of trace elements in the atmosphere

International Nuclear Information System (INIS)

Drava, Giuliana; Brignole, Daniele; Giordani, Paolo; Minganti, Vincenzo

2017-01-01

Tree bark has proved to be a useful bioindicator for trace elements in the atmosphere, however it reflects an exposure occurring during an unidentified period of time, so it provides spatial information about the distribution of contaminants in a certain area, but it cannot be used to detect temporal changes or trends, which is an important achievement in environmental studies. In order to obtain information about a known period of time, the bark collected from the annual segments of tree branches can be used, allowing analyses going back 10–15 years with annual resolution. In the present study, the concentrations of As, Cd, Co, Cu, Fe, Mn, Ni, Pb, V and Zn were measured by atomic emission spectrometry in a series of samples covering the period from 2001 to 2013 in an urban environment. Downward time trends were significant for Cd, Pb and Zn. The only trace element showing an upward time trend was V. The concentrations of the remaining six trace elements were constant over time, showing that their presence in bark is not simply proportional to the duration of exposure. This approach, which is simple, reliable and widely applicable at a low cost, allows the “a posteriori” reconstruction of atmospheric trace element deposition when or where no monitoring programme is in progress and no other natural archives are available. - Highlights: • Branch bark allows the historical reconstruction of atmospheric trace elements. • This approach is simple, reliable, widely applicable and “a posteriori”. • Downward time trends were found for Cd, Pb and Zn; upward trend for V.

The bark of the branches of holm oak (Quercus ilex L.) for a retrospective study of trace elements in the atmosphere

Energy Technology Data Exchange (ETDEWEB)

Drava, Giuliana, E-mail: drava@difar.unige.it; Brignole, Daniele; Giordani, Paolo; Minganti, Vincenzo

2017-04-15

Tree bark has proved to be a useful bioindicator for trace elements in the atmosphere, however it reflects an exposure occurring during an unidentified period of time, so it provides spatial information about the distribution of contaminants in a certain area, but it cannot be used to detect temporal changes or trends, which is an important achievement in environmental studies. In order to obtain information about a known period of time, the bark collected from the annual segments of tree branches can be used, allowing analyses going back 10–15 years with annual resolution. In the present study, the concentrations of As, Cd, Co, Cu, Fe, Mn, Ni, Pb, V and Zn were measured by atomic emission spectrometry in a series of samples covering the period from 2001 to 2013 in an urban environment. Downward time trends were significant for Cd, Pb and Zn. The only trace element showing an upward time trend was V. The concentrations of the remaining six trace elements were constant over time, showing that their presence in bark is not simply proportional to the duration of exposure. This approach, which is simple, reliable and widely applicable at a low cost, allows the “a posteriori” reconstruction of atmospheric trace element deposition when or where no monitoring programme is in progress and no other natural archives are available. - Highlights: • Branch bark allows the historical reconstruction of atmospheric trace elements. • This approach is simple, reliable, widely applicable and “a posteriori”. • Downward time trends were found for Cd, Pb and Zn; upward trend for V.

Study on bone resorption behavior of osteoclast under drug effect using {sup 41}Ca tracing

Energy Technology Data Exchange (ETDEWEB)

Dong Kejun [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); Lu Liyan [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); CNNC Third Qinshan Nuclear Power Co. Ltd., Haiyan 314300 (China); He Ming; Ouyang Yinggen; Xue Yan; Li Chaoli; Wu Shaoyong [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); Wang Xianggao [College of Physics Science and Technology, Guangxi University, Nanning 530004 (China); Shen Hongtao [College of Physics and Technology, Guangxi Normal University, Guilin 541004 (China); Gao Jianjun [Institute of Radiation Medicine, Fudan University, Shanghai 200032 (China); Wang Wei [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); China National Nuclear Corporation, Beijing 100822 (China); Chen Dafu; Xing Yonggang [Beijing Research Institute of Traumatology and Orthopaedics, Beijing 100035 (China); Jian, Yuan [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); Jiang Shan, E-mail: jiangs@ciae.ac.cn [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China)

2013-01-15

The mechanisms governing calcium fluxes during bone remodeling processes in Osteoporosis (OP) patients are poorly known. Understanding the changes of Osteoclasts (OC) during this dynamic transition is important to prevent and cure OP. The exploration of long-lived {sup 41}Ca (T{sub 1/2} = 1.04 Multiplication-Sign 10{sup 5} years) tracer combined with AMS measurements leads to the possibility of monitoring the bone resorption behavior of OC in OP patients. In this work, the behavior of OC with the administration of Strontium Ranelate (SR), a drug for OP, was studied by using {sup 41}Ca labeled hydroxyapatite (HAP) to simulate the bone. AMS on the HI-13 tandem accelerator at CIAE was used to determine trace amounts of {sup 41}Ca. The results show that the technique of {sup 41}Ca tracing with AMS can be used to quantitatively monitor the behavior of OC in bone resorption under the effects of drugs. Experimental details and preliminary results will be presented.

Tracing carbon flow from microphytobenthos to major bacterial groups in an intertidal marine sediment by using an in situ

NARCIS (Netherlands)

Miyatake, T.; Moerdijk-Poortvliet, T.C.W.; Stal, L.J.; Boschker, H.T.S.

2014-01-01

Carbon flow from benthic diatoms to heterotrophic bacterial was traced in an intertidal sediment for 5consecutive days. 13C-labeled bicarbonate was sprayed onto the sediment surface during low tide and 13C-labelincorporation in major carbon pools, intermediate metabolites, and biomarkers were

Ability Grouping in Social Studies.

Science.gov (United States)

Social Education, 1992

1992-01-01

Presents a position statement of the National Council for the Social Studies (NCSS). Reports that the NCSS objects to ability grouping in social studies. Argues that ability grouping disadvantages minority, handicapped, and low ability students. Suggests that ability grouping undermines the democratic ideals that should be the basis of the social…

Survey of currently available reference materials for use in connection with the determination of trace elements in biological materials

International Nuclear Information System (INIS)

Parr, R.M.

1983-09-01

Elemental analysis of biological materials is at present the subject of intensive study by many different research groups throughout the world, in view of the importance of these trace elements in health and medical diagnosis. IAEA and other organizations are now making a variety of suitable reference materials available for use in connection with the determination of trace elements in biological materials. To help analysts in making a selection from among these various materials, the present report provides a brief survey of data for all such biological reference materials known to the author. These data are compiled by the author from January 1982 to June 1983

Long-term anaerobic digestion of food waste stabilized by trace elements

International Nuclear Information System (INIS)

Zhang Lei; Jahng, Deokjin

2012-01-01

Highlights: ► Korean food waste was found to contain low level of trace elements. ► Stable anaerobic digestion of food waste was achieved by adding trace elements. ► Iron played an important role in anaerobic digestion of food waste. ► Cobalt addition further enhanced the process performance in the presence of iron. - Abstract: The purpose of this study was to examine if long-term anaerobic digestion of food waste in a semi-continuous single-stage reactor could be stabilized by supplementing trace elements. Contrary to the failure of anaerobic digestion of food waste alone, stable anaerobic digestion of food waste was achieved for 368 days by supplementing trace elements. Under the conditions of OLR (organic loading rates) of 2.19–6.64 g VS (volatile solid)/L day and 20–30 days of HRT (hydraulic retention time), a high methane yield (352–450 mL CH 4 /g VS added ) was obtained, and no significant accumulation of volatile fatty acids was observed. The subsequent investigation on effects of individual trace elements (Co, Fe, Mo and Ni) showed that iron was essential for maintaining stable methane production. These results proved that the food waste used in this study was deficient in trace elements.

The Possible Protective Role of Green Tea against Radiation induced Certain Biochemical and Trace Element Changes in Rats

International Nuclear Information System (INIS)

Hanna, M.M.A.

2012-01-01

The process of ionization occurring after radiation energy absorption in atoms and molecules of biological matter results in biochemical alterations, which cause damage to cellular elements. This damage is mediated through generation of reactive oxygen species (ROS) that in turn damage proteins, lipids, nucleic-acids and trace elements. They also can attack poly unsaturated fatty acids and initiate lipid peroxidation within the cell. So the present study was constructed in order to assess the role of green tea extract (GTE) (300 mg/kg) to overcome the hazards of ionizing radiation. The parameters studied in the current work were serum AST, ALT and ALP activities as well as serum levels of cholesterol, triglyceride, urea and creatinine. Liver and kidney glutathione (GSH), lipid peroxidation (TBARS) and metallothioneins (MTs) contents were also investigated. In addition, contents of some trace elements (Fe, Cu, Zn, Ca, Mg, Se and Mn) in liver, kidney, spleen and testis tissues as well as the content of these trace elements in green tea plant and green tea extract were also estimated. Vitamin E was selected and used at dose of 40 mg/kg as reference standard. Male Wistar albino rats (48) were used, weighing 120-150 g, divided into 6 groups, each consists of 8 rats: Group (1) → received saline for 28 days and served as normal group, Group (2) → received GTE once daily for 28 days, Group (3) → received vitamin E once daily for 28 days, Group 4 → received saline for 21 days then were exposed to 6.5 Gy single dose whole body gamma irradiation followed by receiving saline for 7 days later and served as irradiated control, Group (5) → received GTE once daily for 21 days, and then were exposed to single dose whole body gamma irradiation (6.5 Gy), followed by treatment with GTE 7 days later to be 28 days as group 2 and Group (6) → received vitamin E once daily for 21 days, and then were exposed to single dose whole body gamma irradiation (6.5 Gy), followed by

Application of trace element analysis to determine trace element concentrations in the field of medicine. [Neutrons

Energy Technology Data Exchange (ETDEWEB)

Kasperek, K; Feinendegen, L E

1976-01-01

Applied trace elements research in medicine requires a sensitive and efficient technique of trace elements analysis, such as neutron activation analysis. Essential trace elements act as stabilizators (iron in haem), structural elements (silicon in fibrous tissue), in hormones (iodine in thyroid hormone), in vitamins (cobalt in vitamin B 12), and in enzymes. Most of the essential trace elements act as coenzymes or in coenzymes or directly as metabolic catalyzers. For example, selenium deficiency in PKU and maple syrup patients receiving dietary treatment can be detected by determining the selenium content of the serum, while low selenium values in the whole blood indicate liver cirrhosis. Acrodermatitis enteropathica can be diagnosed by determinig zinc in the serum, and pancreatic insufficiency by determining zinc in the pancreatic juice. Zinc also plays a part in disturbances of growth, in the healing of wounds, and in the insulin metabolism. Cobalt is important in some types of anaemia and in myocardiopathies. Trace elements are also necessary in the treatment of diseases, e.g. iron cobalt in some types of anaemia, and zinc in the delayed healing of wounds in the postoperative phase and in acrodermatitis enteropathica. Chromium is now being tested for the treatment of diabetes mellitus, and fluorides may be of interest in the treatment of osteoporosis. Finally, trace elements are important in the aetiology of acute poisoning, in nutrition, and in environmental protection.

Trace spaces in a pre-cubical complex

DEFF Research Database (Denmark)

Raussen, Martin

2009-01-01

In directed algebraic topology, directed irreversible (d)-paths and spaces consisting of d-paths are studied from a topological and from a categorical point of view. Motivated by models for concurrent computation, we study in this paper spaces of d-paths in a pre-cubical complex. Such paths...... are equipped with a natural arc length which moreover is shown to be invariant under directed homotopies. D-paths up to reparametrization (called traces) can thus be represented by arc length parametrized d-paths. Under weak additional conditions, it is shown that trace spaces in a pre-cubical complex...... are separable metric spaces which are locally contractible and locally compact. Moreover, they have the homotopy type of a CW-complex....

A Virtual Reality Visualization Tool for Neuron Tracing.

Science.gov (United States)

Usher, Will; Klacansky, Pavol; Federer, Frederick; Bremer, Peer-Timo; Knoll, Aaron; Yarch, Jeff; Angelucci, Alessandra; Pascucci, Valerio

2018-01-01

Tracing neurons in large-scale microscopy data is crucial to establishing a wiring diagram of the brain, which is needed to understand how neural circuits in the brain process information and generate behavior. Automatic techniques often fail for large and complex datasets, and connectomics researchers may spend weeks or months manually tracing neurons using 2D image stacks. We present a design study of a new virtual reality (VR) system, developed in collaboration with trained neuroanatomists, to trace neurons in microscope scans of the visual cortex of primates. We hypothesize that using consumer-grade VR technology to interact with neurons directly in 3D will help neuroscientists better resolve complex cases and enable them to trace neurons faster and with less physical and mental strain. We discuss both the design process and technical challenges in developing an interactive system to navigate and manipulate terabyte-sized image volumes in VR. Using a number of different datasets, we demonstrate that, compared to widely used commercial software, consumer-grade VR presents a promising alternative for scientists.

Marine lake as in situ laboratory for studies of organic matter influence on speciation and distribution of trace metals

Science.gov (United States)

Mlakar, Marina; Fiket, Željka; Geček, Sunčana; Cukrov, Neven; Cuculić, Vlado

2015-07-01

Karst marine lakes are unique marine systems, also recognized as in situ "laboratories" in which geochemical processes on a different scale compared to the open sea, can be observed. In this study, organic matter cycle and its impact on distribution of trace metals in the marine lake Mir, located on Dugi Otok Island, in the central part of the eastern Adriatic Sea, was investigated for the first time. Studied marine lake is small, isolated, shallow basin, with limited communication with the open sea. Intense spatial and seasonal variations of organic matter, dissolved and particulate (DOC, POC), and dissolved trace metals concentrations in the water column of the Lake are governed predominantly by natural processes. Enhanced oxygen consumption in the Lake during summer season, high DOC and POC concentrations and low redox potential result in occasional occurrence of anoxic conditions in the bottom layers with appearance of sulfur species. Speciation modeling showed that dissolved trace metals Cu, Pb and Zn, are mostly bound to organic matter, while Cd, Co and Ni are present predominantly as free ions and inorganic complexes. Trace metals removal from the water column and their retention in the sediment was found to depend on the nature of the relationship between specific metal and organic or inorganic phases, sulfides, Fe-oxyhydroxydes or biogenic calcite. The above is reflected in the composition of the sediments, which are, in addition to influence of karstic background and bathymetry of the basin, significantly affected by accumulation of detritus at the bottom of the Lake.

Identifying sources of groundwater pollution using trace element signatures

International Nuclear Information System (INIS)

Olmez, I.; Hayes, M.J.

1990-01-01

A simple receptor modeling approach has been applied to groundwater pollution studies and has shown that marker trace elements can be used effectively in source identification and apportionment. Groundwater and source materials from one coal-fired and five oil-fired power plants, and one coal-tar deposit site have been analyzed by instrumental neutron activation analysis for more than 20 minor and trace elements. In one of the oil-fired power plants, trace element patterns indicated a leak from the hazardous waste surface impoundments owing to the failure of a hypolon liner. Also, the extent and spatial distribution of groundwater contamination have been determined in a coal-tar deposit site

NSF-RANN trace contaminants abstracts

International Nuclear Information System (INIS)

Copenhaver, E.D.; Harnden, D.S.

1976-10-01

Specific areas of interest of the Environmental Aspects of Trace Contaminants Program are organic chemicals of commerce, metals and organometallic compounds, air-borne contaminants, and environmental assay methodology. Fifty-three abstracts of literature on trace contaminants are presented. Author, keyword, and permuted title indexes are included

Spiral tracing on a touchscreen is influenced by age, hand, implement, and friction.

Science.gov (United States)

Heintz, Brittany D; Keenan, Kevin G

2018-01-01

Dexterity impairments are well documented in older adults, though it is unclear how these influence touchscreen manipulation. This study examined age-related differences while tracing on high- and low-friction touchscreens using the finger or stylus. 26 young and 24 older adults completed an Archimedes spiral tracing task on a touchscreen mounted on a force sensor. Root mean square error was calculated to quantify performance. Root mean square error increased by 29.9% for older vs. young adults using the fingertip, but was similar to young adults when using the stylus. Although other variables (e.g., touchscreen usage, sensation, and reaction time) differed between age groups, these variables were not related to increased error in older adults while using their fingertip. Root mean square error also increased on the low-friction surface for all subjects. These findings suggest that utilizing a stylus and increasing surface friction may improve touchscreen use in older adults.

Spatial variations in trace element concentrations of the sea urchin, Paracentrotus lividus, a first reference study in the Mediterranean Sea.

Science.gov (United States)

Ternengo, S; Marengo, M; El Idrissi, O; Yepka, J; Pasqualini, V; Gobert, S

2018-04-01

A study on Trace Elements (TE) from sea urchin gonads has been conducted in the western Mediterranean Sea. Contamination data were used to determine a Trace Method Pollution Index (TEPI). TE concentrations varied considerably depending on the location of the sampling stations. The results showed that five trace elements (Zn, Fe, As, Al, Cu) are ubiquitous. The geographical area considered (Corsica) represents an important range of environmental conditions and types of pressure that can be found in the western Mediterranean Sea. TEPI was used to classify the studied sites according to their degree of contamination and allowed reliable comparison of TE contamination between local and international sites. TE contamination of the western Mediterranean Sea displayed a north-to-south gradient, from the Italian coasts down through the insular Corsican coasts to the north African littoral. Due to the increasing environmental pressure on the Mediterranean Sea, a regular monitoring of TE levels in marine organisms is necessary to prevent any further environmental deterioration. Copyright © 2018 Elsevier Ltd. All rights reserved.

Geometry-invariant GRIN lens: finite ray tracing.

Science.gov (United States)

Bahrami, Mehdi; Goncharov, Alexander V

2014-11-17

The refractive index distribution of the geometry-invariant gradient refractive index lens (GIGL) model is derived as a function of Cartesian coordinates. The adjustable external geometry of the GIGL model aims to mimic the shape of the human and animal crystalline lens. The refractive index distribution is based on an adjustable power-law profile, which provides additional flexibility of the model. An analytical method for layer-by-layer finite ray tracing through the GIGL model is developed and used to calculate aberrations of the GIGL model. The result of the finite ray tracing aberrations of the GIGL model are compared to those obtained with paraxial ray tracing. The derived analytical expression for the refractive index distribution can be employed in the reconstruction processes of the eye using the conventional ray tracing methods. The layer-by-layer finite ray tracing approach would be an asset in ray tracing through a modified GIGL model, where the refractive index distribution cannot be described analytically. Using the layer-by-layer finite ray-tracing method, the potential of the GIGL model in representing continuous as well as shell-like layered structures is illustrated and the results for both cases are presented and analysed.

Trace Elements in Human Tooth Enamel

Energy Technology Data Exchange (ETDEWEB)

Nixon, G. S. [Turner Dental School, University Of Manchester, Manchester (United Kingdom); Smith, H.; Livingston, H. D. [Department of Forensic Medicine, University Of Glasgow, Glasgow (United Kingdom)

1967-10-15

The trace elements are considered to play a role in the resistance of teeth to dental caries. The exact mechanism by which they act has not yet been fully established. Estimations of trace elements have been undertaken in sound human teeth. By means of activation analysis it has been possible to determine trace element concentrations in different layers of enamel in the same tooth. The concentrations of the following elements have been determined: arsenic, antimony, copper, zinc, manganese, mercury, molybdenum and vanadium. The distribution of trace elements in enamel varies from those with a narrow range, such as manganese, to those with a broad range, such as antimony. The elements present in the broad range are considered to be non-essential and their presence is thought to result from a chance incorporation into the enamel. Those in the narrow range appear to be essential trace elements and are present in amounts which do not vary unduly from other body tissues. Only manganese and zinc were found in higher concentrations in the surface layer of enamel compared with the inner layers. The importance of the concentration of trace elements on this surface layer of enamel is emphasized as this layer is the site of the first attack by the carious process. (author)

Distributed trace using central performance counter memory

Science.gov (United States)

Satterfield, David L.; Sexton, James C.

2013-01-22

A plurality of processing cores, are central storage unit having at least memory connected in a daisy chain manner, forming a daisy chain ring layout on an integrated chip. At least one of the plurality of processing cores places trace data on the daisy chain connection for transmitting the trace data to the central storage unit, and the central storage unit detects the trace data and stores the trace data in the memory co-located in with the central storage unit.

Urea nitrate, an exceptionally easy-to-make improvised explosive: studies towards trace characterization.

Science.gov (United States)

Tamiri, Tsippy; Rozin, Rinat; Lemberger, Nitay; Almog, Joseph

2009-09-01

Urea nitrate is a powerful improvised explosive, frequently used by terrorists in the Israeli arena. It was also used in the first World Trade Center bombing in New York in February 1993. It is difficult to identify urea nitrate in post-explosion debris, since only a very small fraction survives the blast. Also, in the presence of water, it readily decomposes to its original components, urea and nitric acid. It is suspected that post-blast debris of urea nitrate can be confused with ammonium nitrate, the main solid product of urea nitrate thermal decomposition. In a comprehensive study towards identification of urea nitrate in post-blast traces, a spectrophotometric technique for quantitative determination of urea nitrate was developed, and conditions were found for extraction and separation of un-exploded traces of urea nitrate with minimal decomposition. Nevertheless, out of 28 samples collected from a series of three controlled firings of urea nitrate charges, only one gave the typical adduct ion by liquid chromatography/mass spectrometry analysis. We found that urea nitrate can be extracted from solid mixtures to organic solvents by using Crown ethers as "host compounds." The adducts thus formed are solid, crystalline compounds that can be characterized by microanalysis and spectroscopic techniques.

Feasibility Study of Coupling the CASMO-4/TABLES-3/SIMULATE-3 Code System to TRACE/PARCS

International Nuclear Information System (INIS)

Demaziere, Christophe; Staalek, Mathias

2004-12-01

This report investigates the feasibility of coupling the Studsvik Scandpower CASMO-4/TABLES-3/SIMULATE-3 codes to the US NRC TRACE/PARCS codes. The data required by TRACE/PARCS are actually the ones necessary to run its neutronic module PARCS. Such data are the macroscopic nuclear cross-sections, some microscopic nuclear cross-sections important for the Xenon and Samarium poisoning effects, the Assembly Discontinuity Factors, and the kinetic parameters. All these data can be retrieved from the Studsvik Scandpower codes. The data functionalization is explained in detail for both systems of codes and the possibility of coupling each of these codes to TRACE/PARCS is discussed. Due to confidentiality restrictions in the use of the CASMO-4 files and to an improper format of the TABLES-3 output files, it is demonstrated that TRACE/PARCS can only be coupled to SIMULATE-3. Specifically-dedicated SIMULATE-3 input decks allow easily editing the neutronic data at specific operating statepoints. Although the data functionalization is different between both systems of codes, such a procedure permits reconstructing a set of data directly compatible with PARCS

Groundwater contamination with arsenic and other trace elements in an area of the Pampa, province of Cordoba, Argentina

International Nuclear Information System (INIS)

Nicolli, H.B.; Suriano, J.M.; Gomez Peral, M.A.; Ferpozzi, L.H.; Baleani, O.A.

1989-01-01

A geochemical study of the groundwater of the pampa in the province of Cordoba, Argentina, is reported. Physical-chemical parameters, dissolved solids, and seven trace elements were determined in 60 selected water samples. Systematic and accurate measurements of arsenic, fluorine, and vanadium were performed for the first time. The geographic distribution of the seven trace elements was mapped and its correlation with the anion-cation composition of the water was studied. Eighty-four percent of the water analyzed showed arsenic contents over 0.05 mg/l. The maxima for arsenic, fluorine, vanadium, and uranium contents were found in the western part of the study area, in waters dominated by alkali metal cations. Maximum selenium and antimony contents were found in the eastern part of the areas, whereas molybdenum distribution showed no relationship to the other groups. The movements of the subsoil have disturbed surface and subsurface drainage, thus influencing the water salinity and trace element contents. To investigate the origin of contamination, 54 loess samples were collected at wells in depths ranging from the surface down to the water table. This loess, which has a high proportion of volcanic components, mainly rhyolitic glass, exhibits a chemical composition corresponding to that of a dacite. The loess and volcanic glass show anomalous contents of all contaminant trace elements, mainly arsenic and selenium. For this reason, loess is considered to be the most important source of contamination of this ground water area. 30 refs., 6 figs., 9 tab

Enrichment of trace elements in bottom ash from coal oxy-combustion: Effect of coal types

CSIR Research Space (South Africa)

Oboirien, BO

2016-09-01

Full Text Available In this study, the enrichment of trace elements in two coals under air and oxy-combustion conditions was studied. Twenty-one trace elements were evaluated. The two coal samples had a different concentration for the 21 trace elements, which was due...

Essential trace elements in milk and blood serum of lactating donkeys as affected by lactation stage and dietary supplementation with trace elements.

Science.gov (United States)

Fantuz, F; Ferraro, S; Todini, L; Mariani, P; Piloni, R; Salimei, E

2013-11-01

The aim of this trial was to study the concentration of zinc (Zn), iron (Fe), copper (Cu), manganese (Mn), selenium (Se), cobalt (Co) and iodine (I) in milk and blood serum of lactating donkeys, taking into account the effects of lactation stage and dietary supplementation with trace elements. During a 3-month period, 16 clinically healthy lactating donkeys (Martina-Franca-derived population), randomly divided into two homogeneous groups (control (CTL) and trace elements (TE)), were used to provide milk and blood samples at 2-week intervals. Donkeys in both groups had continuous access to meadow hay and were fed 2.5 kg of mixed feed daily, divided into two meals. The mixed feed for the TE group had the same ingredients as the CTL, but was supplemented with a commercial premix providing 163 mg Zn, 185 mg Fe, 36 mg Cu, 216 mg Mn, 0.67 mg Se, 2.78 mg Co and 3.20 mg I/kg mixed feed. The concentrations of Zn, Fe, Cu, Mn, Se, Co and I were measured in feeds, milk and blood serum by inductively coupled plasma-MS. Data were processed by ANOVA for repeated measures. The milk concentrations of all the investigated elements were not significantly affected by the dietary supplementation with TE. Serum concentrations of Zn, Fe, Cu Mn and Se were not affected by dietary treatment, but TE-supplemented donkeys showed significantly higher concentrations of serum Co (1.34 v. 0.69 μg/l) and I (24.42 v. 21.43 μg/l) than unsupplemented donkeys. The effect of lactation stage was significant for all the investigated elements in milk and blood serum, except for serum manganese. A clear negative trend during lactation was observed for milk Cu and Se concentrations (-38%), whereas that of Mn tended to increase. The serum Cu concentration was generally constant and that of Co tended to increase. If compared with data reported in the literature for human milk, donkey milk showed similarities for Zn, Mn, Co and I. Furthermore, this study indicated that, in the current experimental conditions

Tracing Assessment for learning Capability in Teachers (TACT)

DEFF Research Database (Denmark)

Otrel-Cass, Kathrin; Agerbo, Jette Nørgaard; Skipper-Jørgensen, Anette

2018-01-01

education program. This chapter presents preliminary survey and focus group interviews data after tracing 21 pre-service teachers over two years. Our findings reflected a picture of Danish student teachers who value in particular formative assessment practices, while summative assessment is acknowledged......The focus on assessment literate teachers who know how to construct, administer assessments and communicate learning outcomes on student learning raises questions on how student teachers can develop the necessary skills to assess their students' learning. This is so important since...... there is evidence that beginning teachers continue to feel under prepared to assess student learning. This chapter presents findings of a study conducted in Denmark with the aim of investigating how student teacher candidates develop the capacities to become ‘assessment literate' over the course of their teacher...

Group-analytic training groups for psychology students: A qualitative study

DEFF Research Database (Denmark)

Nathan, Vibeke Torpe; Poulsen, Stig

2004-01-01

This article presents results from an interview study of psychology students' experiences from group-analytic groups conducted at the University of Copenhagen. The primary foci are the significance of differences in themotivation participants'  personal aims of individual participantsfor particip......This article presents results from an interview study of psychology students' experiences from group-analytic groups conducted at the University of Copenhagen. The primary foci are the significance of differences in themotivation participants'  personal aims of individual participantsfor...... participation in the group, the impact of the composition of participants on the group process, and the professional learning through the group experience. In general the interviews show a marked satisfaction with the group participation. In particular, learning about the importance of group boundaries...

Measurement of some radiologically and nutritionally important trace elements in human milk and commercially available milk

International Nuclear Information System (INIS)

Nair, Suma; Sathyapriya, R.S.; Nair, M.G.; Ravi, Prabhat; Bhati, Sharda

2011-01-01

Milk is considered to be a complete food and an almost indispensable part of the diets of infants and children. In this paper we present the concentration of some radiologically and nutritionally important trace elements such as Th, Cs, Co, Rb, Fe, Ca and Zn present in human milk and commercially available milk. The trace elements in human and other milk samples were determined using instrumental neutron activation analysis technique. The results show that higher concentrations of Th, Cs, Ca and Rb were found in ordinary milk samples in comparison with the human milk samples. Whereas, a higher concentrations of Fe and Co were observed in human milk samples. These data will be useful for the nutritional and biokinetic studies of these elements in infants and children of different age groups. (author)

A Global Overview of Exposure Levels and Biological Effects of Trace Elements in Penguins.

Science.gov (United States)

Espejo, Winfred; Celis, José E; GonzÃlez-Acuña, Daniel; Banegas, Andiranel; Barra, Ricardo; Chiang, Gustavo

2018-01-01

Trace elements are chemical contaminants that can be present almost anywhere on the planet. The study of trace elements in biotic matrices is a topic of great relevance for the implications that it can have on wildlife and human health. Penguins are very useful, since they live exclusively in the Southern Hemisphere and represent about 90% of the biomass of birds of the Southern Ocean. The levels of trace elements (dry weight) in different biotic matrices of penguins were reviewed here. Maps of trace element records in penguins were included. Data on exposure and effects of trace elements in penguins were collected from the literature. The most reported trace elements in penguins are aluminum, arsenic, cadmium, lead, mercury, copper, zinc, and manganese. Trace elements have been measured in 11 of the 18 species of penguins. The most studied biotic matrices are feathers and excreta. Most of the studies have been performed in Antarctica and subantarctic Islands. Little is known about the interaction among metals, which could provide better knowledge about certain mechanisms of detoxification in penguins. Future studies of trace elements in penguins must incorporate other metals such as vanadium, cobalt, nickel, and chromium. Data of metals in the species such as Eudyptes pachyrhynchus, Eudyptes moseleyi, Eudyptes sclateri, Eudyptes robustus, Eudyptes schlegeli, Spheniscus demersus, Spheniscus mendiculus, and Megadyptes antipodes are urged. It is important to correlate levels of metals in different biotic matrices with the effects on different species and in different geographic locations.

Study in Vietnam on ingestion and organ content of trace elements of importance in radiological protection (Cs, I, Sr, U, Th etc.)

International Nuclear Information System (INIS)

Nguyen Mong Sinh

2000-01-01

This report presents results of our investigation work carried out from November 1996 to April 1998 in the field of 'Study in Vietnam on ingestion and organ content of trace elements of importance in Radiological Protection'. This work related to the Co-ordinated Research Programme for Reference Asian Man Project, Phase 2. The data reported are the daily individual intake of the elements of interest for some different socio-economic groups of Vietnamese population living in Hanoi, Hochiminh city Vinh Phu and Dalat areas. The obtained results showed that the average content for four elements (Cs, I, U, Th) in Vietnamese dietary intakes slightly changes from area to area in dependence on geographical, natural and socio-economical conditions, on type and composition of foods. (author)

Association between level of urinary trace heavy metals and obesity among children aged 6-19 years: NHANES 1999-2011.

Science.gov (United States)

Shao, Wentao; Liu, Qian; He, Xiaowei; Liu, Hui; Gu, Aihua; Jiang, Zhaoyan

2017-04-01

Global prevalence of obesity has been increasing dramatically in all ages. Although traditional causes for obesity development have been studied widely, it is unclear whether environmental exposure of substances such as trace heavy metals affects obesity development among children and adolescents so far. Data from the National Health and Nutrition Examination Survey (1999-2011) were retrieved, and 6602 US children were analyzed in this study. Urinary level of nine trace heavy metals, including barium, cadmium, cobalt, cesium, molybdenum, lead, antimony, thallium, and tungsten, was analyzed for their association with the prevalence of obesity among children aged 6-19 years. Multiple logistic regression was performed to assess the associations adjusted for age, race/ethnicity, gender, urinary creatinine, PIR, serum cotinine, and television, video game, and computer usage. A remarkable association was found between barium exposure (OR 1.43; 95% CI 1.09-1.88; P obesity in children aged 6-19 years. Negative association was observed between cadmium (OR 0.46; 95% CI 0.33-0.64; P obesity. All the negative associations were stronger in the 6-12 years group than in the 13-19 years group. The present study demonstrated that barium might increase the occurrence of obesity, but cadmium, cobalt, and lead caused weight loss among children. The results imply that trace heavy metals may represent critical risk factors for the development of obesity, especially in the area that the state of metal contamination is serious.

Perspective on the audit calculation for SFR using TRACE code

Energy Technology Data Exchange (ETDEWEB)

Shin, An Dong; Choi, Yong Won; Bang, Young Suk; Bae, Moo Hoon; Huh, Byung Gil; Seol, Kwang One [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

2012-10-15

Korean Sodium Cooled Fast Reactor (SFR) is being developed by KAERI. The Prototype SFR will be a first SFR applied for licensing. KINS started research programs for preparing new concept design licensing recently. Safety analysis for the certain reactor is based on the computational estimation with conservatism and/or uncertainty of modeling. For the audit calculation for sodium cooled fast reactor (SFR), TRACE code is considered as one of analytical tool for SFR since TRACE code have already sodium related properties and models in it and have experience in the liquid metal coolant system area in abroad. Applicability of TRACE code for SFR is prechecked before real audit calculation. In this study, Demonstration Fast Reactor (DFR) 600 steady state conditions is simulated for identification of area of modeling improvements of TRACE code.

The Ring of Five follows the traces

International Nuclear Information System (INIS)

Anon.

2015-01-01

The Ring of Five is an informal network of European experts in radioactivity detection belonging to public bodies such as the IRSN. After having evoked different cases of detection (detection of unusual traces of iodine 131 in the region of Stockholm in 2015, detection of high levels of traces of caesium 137 in Switzerland in 1968) which leaded to the identification of the origin of these traces, this article briefly recalls the history of the creation of this network which extended with the occurrence of the Chernobyl accident, describes how the information is transmitted, the use of modelling tools, and outlines that the detection of some species can be associated either to a nuclear accident or to an atmospheric nuclear bomb test, and indicates how new sensors, not sensitive to humidity, have been developed after a lack of detection of iodine 131. In a brief interview, the future of the Ring of Five, topics to be studied and current projects are briefly evoked

Ultra-Trace Analysis of Krypton-85

International Nuclear Information System (INIS)

Daerr, H.; Kalinowski, M.; Kohler, M.; Sahling, P.

2010-01-01

To strengthen the efficiency and effectiveness of nuclear safeguards for detecting undeclared nuclear material and activities we propose to use the radioactive krypton isotope Krypton-85 as a tracer for clandestine plutonium production. The main idea is to detect inexplicable atmospheric Kr85 concentration using the novel technology atom trap trace analysis (ATTA) in order to detect an undeclared reprocessing facility. The Additional Protocol (INFCIRC/540, 1997) establishes the possibility to take environmental samples. Krypton-85 has a combination of unique features which makes it an ideal tracer for plutonium separation activities anywhere in the world. It is always generated along with plutonium and 99.9% remains within the fuel cladding. Due to its half-life of 10.76 years, significant amounts of krypton-85 still remain in the spent fuel even after long cooling times. Krypton is not removed from the atmosphere by any processes like chemical reactions or wash-out. Furthermore, there are no other relevant sources of krypton-85 besides of reprocessing. The novel technology of atom trap trace analysis (ATTA) has been demonstrated by the physics group at Argonne National Laboratory in 1999. This is an ultra-sensitive trace analysis technique able to detect single krypton atoms. We are setting up an ATTA apparatus in our laboratory, which is designed to fulfill all requirements to detect clandestine plutonium production. Our goal is to determine Krypton-85 concentration of one liter samples of atmospheric air with an analysis time of 3 hours. This sample volume reduction is a significant step, since one liter can be taken as a grab sample by sucking it directly into pre-evacuated bottles at atmospheric pressure. The small samples size and the short analysis time of ATTA will make it possible to use krypton-85 as a tracer for clandestine plutonium production with routine operation. (author)

Trace-based post-silicon validation for VLSI circuits

CERN Document Server

Liu, Xiao

2014-01-01

This book first provides a comprehensive coverage of state-of-the-art validation solutions based on real-time signal tracing to guarantee the correctness of VLSI circuits.  The authors discuss several key challenges in post-silicon validation and provide automated solutions that are systematic and cost-effective.  A series of automatic tracing solutions and innovative design for debug (DfD) techniques are described, including techniques for trace signal selection for enhancing visibility of functional errors, a multiplexed signal tracing strategy for improving functional error detection, a tracing solution for debugging electrical errors, an interconnection fabric for increasing data bandwidth and supporting multi-core debug, an interconnection fabric design and optimization technique to increase transfer flexibility and a DfD design and associated tracing solution for improving debug efficiency and expanding tracing window. The solutions presented in this book improve the validation quality of VLSI circuit...

A Theory of Network Tracing

Science.gov (United States)

Acharya, Hrishikesh B.; Gouda, Mohamed G.

Traceroute is a widely used program for computing the topology of any network in the Internet. Using Traceroute, one starts from a node and chooses any other node in the network. Traceroute obtains the sequence of nodes that occur between these two nodes, as specified by the routing tables in these nodes. Each use of Traceroute in a network produces a trace of nodes that constitute a simple path in this network. In every trace that is produced by Traceroute, each node occurs either by its unique identifier, or by the anonymous identifier"*". In this paper, we introduce the first theory aimed at answering the following important question. Is there an algorithm to compute the topology of a network N from a trace set T that is produced by using Traceroute in network N, assuming that each edge in N occurs in at least one trace in T, and that each node in N occurs by its unique identifier in at least one trace in T? We prove that the answer to this question is "No" if N is an even ring or a general network. However, it is "Yes" if N is a tree or an odd ring. The answer is also "No" if N is mostly-regular, but "Yes" if N is a mostly-regular even ring.

The role of the medial prefrontal cortex in trace fear extinction

Science.gov (United States)

Kwapis, Janine L.; Jarome, Timothy J.

2015-01-01

The extinction of delay fear conditioning relies on a neural circuit that has received much attention and is relatively well defined. Whether this established circuit also supports the extinction of more complex associations, however, is unclear. Trace fear conditioning is a better model of complex relational learning, yet the circuit that supports extinction of this memory has received very little attention. Recent research has indicated that trace fear extinction requires a different neural circuit than delay extinction; trace extinction requires the participation of the retrosplenial cortex, but not the amygdala, as noted in a previous study. Here, we tested the roles of the prelimbic and infralimbic regions of the medial prefrontal cortex in trace and delay fear extinction by blocking NMDA receptors during extinction learning. We found that the prelimbic cortex is necessary for trace, but not for delay fear extinction, whereas the infralimbic cortex is involved in both types of extinction. These results are consistent with the idea that trace fear associations require plasticity in multiple cortical areas for successful extinction. Further, the infralimbic cortex appears to play a role in extinction regardless of whether the animal was initially trained in trace or delay conditioning. Together, our results provide new information about how the neural circuits supporting trace and delay fear extinction differ. PMID:25512576

Automated computer analysis of plasma-streak traces from SCYLLAC

International Nuclear Information System (INIS)

Whitman, R.L.; Jahoda, F.C.; Kruger, R.P.

1977-01-01

An automated computer analysis technique that locates and references the approximate centroid of single- or dual-streak traces from the Los Alamos Scientific Laboratory SCYLLAC facility is described. The technique also determines the plasma-trace width over a limited self-adjusting region. The plasma traces are recorded with streak cameras on Polaroid film, then scanned and digitized for processing. The analysis technique uses scene segmentation to separate the plasma trace from a reference fiducial trace. The technique employs two methods of peak detection; one for the plasma trace and one for the fiducial trace. The width is obtained using an edge-detection, or slope, method. Timing data are derived from the intensity modulation of the fiducial trace. To smooth (despike) the output graphs showing the plasma-trace centroid and width, a technique of ''twicing'' developed by Tukey was employed. In addition, an interactive sorting algorithm allows retrieval of the centroid, width, and fiducial data from any test shot plasma for post analysis. As yet, only a limited set of sixteen plasma traces has been processed using this technique

Automated computer analysis of plasma-streak traces from SCYLLAC

International Nuclear Information System (INIS)

Whiteman, R.L.; Jahoda, F.C.; Kruger, R.P.

1977-11-01

An automated computer analysis technique that locates and references the approximate centroid of single- or dual-streak traces from the Los Alamos Scientific Laboratory SCYLLAC facility is described. The technique also determines the plasma-trace width over a limited self-adjusting region. The plasma traces are recorded with streak cameras on Polaroid film, then scanned and digitized for processing. The analysis technique uses scene segmentation to separate the plasma trace from a reference fiducial trace. The technique employs two methods of peak detection; one for the plasma trace and one for the fiducial trace. The width is obtained using an edge-detection, or slope, method. Timing data are derived from the intensity modulation of the fiducial trace. To smooth (despike) the output graphs showing the plasma-trace centroid and width, a technique of ''twicing'' developed by Tukey was employed. In addition, an interactive sorting algorithm allows retrieval of the centroid, width, and fiducial data from any test shot plasma for post analysis. As yet, only a limited set of the plasma traces has been processed with this technique

Fast voxel and polygon ray-tracing algorithms in intensity modulated radiation therapy treatment planning

International Nuclear Information System (INIS)

Fox, Christopher; Romeijn, H. Edwin; Dempsey, James F.

2006-01-01

We present work on combining three algorithms to improve ray-tracing efficiency in radiation therapy dose computation. The three algorithms include: An improved point-in-polygon algorithm, incremental voxel ray tracing algorithm, and stereographic projection of beamlets for voxel truncation. The point-in-polygon and incremental voxel ray-tracing algorithms have been used in computer graphics and nuclear medicine applications while the stereographic projection algorithm was developed by our group. These algorithms demonstrate significant improvements over the current standard algorithms in peer reviewed literature, i.e., the polygon and voxel ray-tracing algorithms of Siddon for voxel classification (point-in-polygon testing) and dose computation, respectively, and radius testing for voxel truncation. The presented polygon ray-tracing technique was tested on 10 intensity modulated radiation therapy (IMRT) treatment planning cases that required the classification of between 0.58 and 2.0 million voxels on a 2.5 mm isotropic dose grid into 1-4 targets and 5-14 structures represented as extruded polygons (a.k.a. Siddon prisms). Incremental voxel ray tracing and voxel truncation employing virtual stereographic projection was tested on the same IMRT treatment planning cases where voxel dose was required for 230-2400 beamlets using a finite-size pencil-beam algorithm. Between a 100 and 360 fold cpu time improvement over Siddon's method was observed for the polygon ray-tracing algorithm to perform classification of voxels for target and structure membership. Between a 2.6 and 3.1 fold reduction in cpu time over current algorithms was found for the implementation of incremental ray tracing. Additionally, voxel truncation via stereographic projection was observed to be 11-25 times faster than the radial-testing beamlet extent approach and was further improved 1.7-2.0 fold through point-classification using the method of translation over the cross product technique

Tracing contacts of TB patients in Malaysia: costs and practicality.

Science.gov (United States)

Atif, Muhammad; Sulaiman, Syed Azhar Syed; Shafie, Asrul Akmal; Ali, Irfhan; Asif, Muhammad

2012-01-01

Tuberculin skin testing (TST) and chest X-ray are the conventional methods used for tracing suspected tuberculosis (TB) patients. The purpose of the study was to calculate the cost incurred by Penang General Hospital on performing one contact tracing procedure using an activity based costing approach. Contact tracing records (including the demographic profile of contacts and outcome of the contact tracing procedure) from March 2010 until February 2011 were retrospectively obtained from the TB contact tracing record book. The human resource cost was calculated by multiplying the mean time spent (in minutes) by employees doing a specific activity by their per-minute salaries. The costs of consumables, Purified Protein Derivative vials and clinical equipment were obtained from the procurement section of the Pharmacy and Radiology Departments. The cost of the building was calculated by multiplying the area of space used by the facility with the unit cost of the public building department. Straight-line deprecation with a discount rate of 3% was assumed for the calculation of equivalent annual costs for the building and machines. Out of 1024 contact tracing procedures, TST was positive (≥10 mm) in 38 suspects. However, chemoprophylaxis was started in none. Yield of contact tracing (active tuberculosis) was as low as 0.5%. The total unit cost of chest X-ray and TST was MYR 9.23 (2.90 USD) & MYR 11.80 (USD 3.70), respectively. The total cost incurred on a single contact tracing procedure was MYR 21.03 (USD 6.60). Our findings suggest that the yield of contact tracing was very low which may be attributed to an inappropriate prioritization process. TST may be replaced with more accurate and specific methods (interferon gamma release assay) in highly prioritized contacts; or TST-positive contacts should be administered 6H therapy (provided that the chest radiography excludes TB) in accordance with standard protocols. The unit cost of contact tracing can be significantly

Neuronal Oscillations Indicate Sleep-dependent Changes in the Cortical Memory Trace.

Science.gov (United States)

Köster, Moritz; Finger, Holger; Kater, Maren-Jo; Schenk, Christoph; Gruber, Thomas

2017-04-01

Sleep promotes the consolidation of newly acquired associative memories. Here we used neuronal oscillations in the human EEG to investigate sleep-dependent changes in the cortical memory trace. The retrieval activity for object-color associations was assessed immediately after encoding and after 3 hr of sleep or wakefulness. Sleep had beneficial effects on memory performance and led to reduced event-related theta and gamma power during the retrieval of associative memories. Furthermore, event-related alpha suppression was attenuated in the wake group for memorized and novel stimuli. There were no sleep-dependent changes in retrieval activity for missed items or items retrieved without color. Thus, the sleep-dependent reduction in theta and gamma oscillations was specific for the retrieval of associative memories. In line with theoretical accounts on sleep-dependent memory consolidation, decreased theta may indicate reduced mediotemporal activity because of a transfer of information into neocortical networks during sleep, whereas reduced parietal gamma may reflect effects of synaptic downscaling. Changes in alpha suppression in the wake group possibly index reduced attentional resources that may also contribute to a lower memory performance in this group. These findings indicate that the consolidation of associative memories during sleep is associated with profound changes in the cortical memory trace and relies on multiple neuronal processes working in concert.

Investigation of trace elements in Elbe water by means of instrumental neutron activation analysis

International Nuclear Information System (INIS)

Motamedi, K.

1977-01-01

Investigations of trace elements in Elbe water were carried out as a contribution to environmental research, hydrology, and geochemistry. The method applied - instrumental neutron activation analysis - is described, and problems connected with the course of analysis - sample taking, handling and preparation as well as optimization of in-pile irradiation and measurement by means of γ spectrometry - are discussed and presented one by one. The computer programme set up for automatic evaluation is described in more detail. This programme AKAN has a very general concept which makes it applicable for general use. The reliability of the evaluation procedure - monostandard method - and the reproducibility of the results are discussed. For the studies, samples were taken at different times, every time from 8 positions along a long section of the Elbe. The content of solids was analyzed; in a number of samples, this was done by separating suspended and dissolved materials. Up to 38 elements were analyzed, whose local and time-dependent concentration curves are given. The contents of some elements are compared with the few available data from literature. Correlation calculations indicate a similar behaviour of single element groups and yield information on the natural origin of the trace elements and on anthropogenic influence to be noticed in the trace element contents. (orig.) [de

Determination of isoniazid concentration in rabbit vertebrae by isotope tracing technique in conjunction with HPLC.

Science.gov (United States)

Liu, Peng; Fu, Zhaozong; Jiang, Jianming; Yuan, Liang; Lin, Zhen

2013-09-01

Medications compounded with isoniazid (INH) are usually applied to surgical sites at the completion of surgery to locally kill postoperative residual tubercle bacilli. However, the distribution and elimination of INH in the vertebrae in vivo are not known. In this study, isotope tracing was used in conjunction with high-pressure liquid chromatography (HPLC) to address this. INH and technetium-99 m-labeled INH were applied to the vertebrae of rabbits. After 2 and 6 h, osseous tissues containing INH, as determined by radionuclide imaging, were collected for detection with HPLC. The results showed that INH mainly stayed around the vertebrae 6 h after its application and did not permeate widely into the blood or other organs, except for the kidneys. The standard deviations of INH concentrations in the technetium-99 m-INH group were approximately four-fold smaller than those in the INH group. This method of coupling isotope tracing and HPLC can effectively limit experimental error during sample collection, allowing accurate and reliable identification of the concentration levels of INH in osseous tissues in vivo. Copyright © 2013 John Wiley & Sons, Ltd.

Utilization of macrominerals and trace elements in pregnant heifers with distinct feed efficiencies.

Science.gov (United States)

Dias, R S; Montanholi, Y R; Lopez, S; Smith, B; Miller, S P; France, J

2016-07-01

The objective of the study was to evaluate utilization of dietary minerals and trace elements in pregnant heifers with distinct residual feed intakes (RFI). Feed intake, body weight (BW), and body composition traits were recorded in 36 crossbred heifers over a period of 37 wk, starting shortly after weaning at 8.3 (0.10; standard deviation) mo of age with an average BW of 276 (7.8) kg. Both BW and body composition were monitored regularly throughout the study, whereas individual feed intake was assessed during the last 84 d of the trial. Data recorded were used to calculate RFI for each heifer. Heifers were ranked based on RFI and assigned to high (n=14) or low (n=10) RFI groups. After the RFI study, 24 selected heifers [age 18.2 (0.14) mo; 87.5 (4.74) d in gestation; 497 (8.5) kg of BW] were used in an indirect digestibility trial (lignin as internal marker). Heifers were fed a ration containing corn silage, haylage, and a mineral premix in which Ca, P, K, Na, Mg, S, Cu, Fe, Mn, Mo, Se, Zn, and Co were provided in the diet according to National Research Council requirements of pregnant replacement heifers. The digestibility trial lasted 1 wk, during which samples of feces were gathered twice daily, and blood and liver biopsy samples were collected on the last day. We noted no significant differences between low- and high-RFI heifers in dry matter digestibility. Apparent absorption of Cu, Zn, and Mn was increased in heifers with low RFI, and apparent absorption of Co tended to be greater for these animals. Concentrations of macrominerals and trace elements in serum of pregnant heifers were similar for both groups except for Se, which was increased in the serum of low-RFI heifers. Liver concentrations of Cu, Fe, Mn, Mo, Se, and Zn did not differ between low- and high-RFI heifers. In conclusion, whereas improved absorption of some trace elements (Cu, Zn, Mn, and Co) and increased Se serum concentration appear to be associated with superior feed efficiency in pregnant

Agreement of Tracing and Direct Viewing Techniques for Cervical Vertebral Maturation Assessment.

Science.gov (United States)

Wiwatworakul, Opas; Manosudprasit, Montian; Pisek, Poonsak; Chatrchaiwiwatana, Supaporn; Wangsrimongkol, Tasanee

2015-08-01

This study aimed to evaluate agreement among three methods for cervical vertebral maturation (CVM) assessment, comprising direct viewing, tracing only, and tracing with digitized points. Two examiners received training and tests of reliability with each CVM method before evaluation of agreement among methods. The subjects were 96 female-cleft lateral cephalometric radiographs (films of eight subjects for each age ranged from seven to 18 years). The examiners interpreted CVM stages of the subjects with four-week interval between uses of each method. The range of weighted kappa values for paired comparisons among the three methods were: 0.96-0.98 for direct viewing and tracing only comparison; 0.93-0.94 for direct viewing and tracing with digitized points comparison; and 0.96-0.97 for tracing only and tracing with digitized points comparison. The intraclass correlation coefficient (ICC) value among the three methods was 0.95. These results indicated very good agreement among methods. Use of direct viewing is suitable for CVM assessment without spending more time for tracing. However, the three methods might be used interchangeably.

The use of cation exchange matrix separation coupled with ICP-MS to directly determine platinum group element (PGE) and other trace element emissions from passenger cars equipped with diesel particulate filters (DPF)

Energy Technology Data Exchange (ETDEWEB)

Cairns, Warren R.L.; Cozzi, Giulio [Institute for the Dynamics of Environmental Processes-CNR, Venice (Italy); De Boni, Antonella; Gabrieli, Jacopo [University of Venice, Department of Environmental Science, Venice (Italy); Asti, Massimo; Merlone Borla, Edoardo; Parussa, Flavio [Centro Ricerche Fiat, Orbassano (Italy); Moretto, Ezio [FIAT Powertrain Technologies S.p.A, Turin (Italy); Cescon, Paolo; Barbante, Carlo [University of Venice, Department of Environmental Science, Venice (Italy); Institute for the Dynamics of Environmental Processes-CNR, Venice (Italy); Boutron, Claude [Laboratoire de Glaciologie et Geophysique de l' Environnement, UMR CNRS 5183, B.P. 96, Saint Martin d' Heres Cedex (France)

2011-03-15

Inductively coupled plasma-mass spectrometry coupled with cation exchange matrix separation has been optimised for the direct determination of platinum group element (PGE) and trace element emissions from a diesel engine car. After matrix separation method detection limits of 1.6 ng g{sup -1} for Pd, 0.4 ng g{sup -1} for Rh and 4.3 ng g{sup -1} for Pt were achieved, the method was validated against the certified reference material BCR 723, urban road dust. The test vehicle was fitted with new and aged catalytic converters with and without diesel particulate filters (DPF). Samples were collected after three consecutive New European Driving Cycle (NEDC) of the particulate and ''soluble'' phases using a home-made sampler optimised for trace element analysis. Emission factors for the PGEs ranged from 0.021 ng km{sup -1} for Rh to 70.5 ng km{sup -1} for Pt; when a DPF was fitted, the emission factors for the PGEs actually used in the catalysts dropped by up to 97% (for Pt). Trace element emission factors were found to drop by a maximum of 92% for Ni to a minimum of 18% for Y when a DPF was fitted; a new DPF was also found to cause a reduction of up to 86% in the emission of particulate matter. (orig.)

The influence of physical activity on hair toxic and essential trace element content in male and female students.

Science.gov (United States)

Zaitseva, Irina P; Skalny, Andrey A; Tinkov, Alexey A; Berezkina, Elena S; Grabeklis, Andrei R; Skalny, Anatoly V

2015-02-01

The primary aim of the current study is to estimate the effect of different physical activity levels on hair trace element content in male and female students. A total of 113 students (59 women and 54 men) of P. G. Demidov Yaroslavl State University (Yaroslavl, Russia) took part in the current investigation. According to the level of the physical activity, all students were divided into three groups: high, medium, and low physical activity. Essential and toxic metal content (μg/g) in hair samples was assessed by inductively coupled plasma mass spectrometry using NexION 300D + NWR213 (Perkin-Elmer, USA). The obtained data show that hair iodine, zinc, arsenic, nickel, and tin levels are not related to physical activity in male and female students. At the same time, increased physical activity is associated with decreased hair copper, vanadium, bismuth, and mercury content in comparison to the low physical activity groups. Students with higher physical activity are also characterized by significantly higher hair cobalt, iron, manganese, selenium, cadmium, lithium, and lead concentrations. Finally, statistical analysis has revealed maximal gender differences in hair trace element content in the high physical activity groups, whereas in the low activity groups, the hair metal concentrations were nearly similar in females and males.

Determination of trace quaternary ammonium surfactants in water by combining solid-phase extraction with surface-assisted laser desorption/ionization mass spectrometry.

Science.gov (United States)

Chen, Y C; Sun, M C

2001-01-01

This study demonstrates the feasibility of combining solid-phase extraction (SPE) with surface-assisted laser desorption/ionization (SALDI) mass spectrometry to determine trace quaternary ammonium surfactants in water. The trace surfactants in water were directly concentrated on the surface of activated carbon sorbent in SPE. The activated carbon sorbent was then mixed with the SALDI liquid for SALDI analysis. No SPE elution procedure was necessary. Experimental results indicate that the surfactants with longer chain alkyl groups exhibit higher sensitivities than those with shorter chain alkyl groups in SPE-SALDI analysis. The detection limit for hexadecyltrimethylammonium bromide is around 10 ppt in SPE-SALDI analysis by sampling 100 mL of aqueous solution, while that of tetradecyltrimethylammonium bromide is about 100 ppt. The detection limit for decyltrimethylammonium bromide and dodecyltrimethylammonium bromide is in the low-ppb range. Copyright 2001 John Wiley & Sons, Ltd.

Distributions of traces of metals on sorption from solutions of vanadium(V)

International Nuclear Information System (INIS)

Evseeva, N.K.; Turnaov, A.N.; Telegin, G.F.; Kremenskaya, I.N.

1983-01-01

A study is made of the distributions of traces of metals between aqueous solutions of vanadium(V) and a solid reagent made by introducing di-2-ethylhexylphosphoric acid into an inert matrix: a nonionic macroporous copolymer of polystyrene with divinyl benzene (wofatit Y 29). As regards degree of extraction, the trace components fall in the series zinc > cadmium > manganese > copper > cobalt, which resemble the extractability series. The vanadium content of the solution and the concentrations of the trace components have virtually no effect on the sorption. The process is effective in concentrating trace components from solutions containing vanadium(V)

LA-ICP-MS Study of Trace Elements in the Chanuskij Metal

Science.gov (United States)

Petaev, Michail I.

2005-01-01

This progress report covers work done during the second year of the 3-year proposal. During this year we resolved many issues relevant to the analytical technique developed by us for measuring trace elements in meteoritic metals. This technique was used to measure concentrations of Fe, Ni, Co, Cr, Cu, Ga, Ge, As, Mo, Ru, Rh, Pd, Sb, W, Re, Os, Ir, Pt, and Au in eight large (120 - 160 microns) metal grains from both "igneous" and "metamorphic" lithologies of the Chanuskij silicate inclusions. The first application of OUT technique to metal grains from thin sections showed some limitations. Small thickness of metal grains in the thin section limited the signal to 3-4 time-slices instead of 10- 1 1 ones in polished sections of iron meteorites studied before.

Using column experiments to examine transport of As and other trace elements released from poultry litter: Implications for trace element mobility in agricultural watersheds

International Nuclear Information System (INIS)

Oyewumi, Oluyinka; Schreiber, Madeline E.

2017-01-01

Trace elements are added to poultry feed to control infection and improve weight gain. However, the fate of these trace elements in poultry litter is poorly understood. Because poultry litter is applied as fertilizer in many agricultural regions, evaluation of the environmental processes that influence the mobility of litter-derived trace elements is critical for predicting if trace elements are retained in soil or released to water. This study examined the effect of dissolved organic carbon (DOC) in poultry litter leachate on the fate and transport of litter-derived elements (As, Cu, P and Zn) using laboratory column experiments with soil collected from the Delmarva Peninsula (Mid-Atlantic, USA), a region of intense poultry production. Results of the experiments showed that DOC enhanced the mobility of all of the studied elements. However, despite the increased mobility, 60–70% of Zn, As and P mass was retained within the soil. In contrast, almost all of the Cu was mobilized in the litter leachate experiments, with very little retention in soil. Overall, our results demonstrate that the mobility of As, Cu, Zn and P in soils which receive poultry litter application is strongly influenced by both litter leachate composition, specifically organic acids, and adsorption to soil. Results have implications for understanding fate and transport of trace elements released from litter application to soil water and groundwater, which can affect both human health and the environment. - Highlights: • Column experiments examined fate of trace elements derived from poultry litter leachate in soils from Delaware, USA. • Influent solutions included poultry litter leachate and simulated solution without DOC. • Results showed increased mobility of litter-derived As, Cu, Zn and P in solution in the presence of DOC. • Mass balance showed all of Cu mass remained in solution but most (60–70%) of the Zn, As and P mass was associated with soil. • Study results show that DOC

Trace elements records from vermetids aragonite as millennial paleo-oceanographic archives in the South-East Mediterranean

Science.gov (United States)

Jacobson, Yitzhak; Yam, Ruth; Shemesh, Aldo

2017-04-01

The Mediterranean Sea is a region under high anthropogenic stress, thus a hotspot for climate change studies. Natural conditions, such as SST, productivity, precipitation and dust fluxes along with human induced activity affect seawater chemistry. We study millennial variability of trace elements in East Mediterranean Sea high-resolution records, in attempt to connect them to environmental factors. The Mediterranean reef builder Vermetid, D. petraeum is a sessile gastropod, secreting its aragonite shells in tidal zones. Cores of Vermetid reefs from the South Eastern Mediterranean (Israel) were previously analyzed by Sisma?Ventura et al. (2014) to reconstruct seawater surface temperature (SST) and δ13C of dissolved inorganic carbon (DIC). In this study we analyzed trace elements of these vermetid cores, and reconstructed millennial records of elements to calcium (el/Ca) molar ratios. Vermetid trace element contents from recent decades are mostly in agreement with known values for marine biogenic aragonites from corals and mollusk. We divide vermetid trace element records into three element groups: 1) Sr and U are related to SST and DIC. These elements correlate with major climatic events of the last millennium, such as the Medieval Warm Period (900-1300 AD) and the Little Ice Age (1450-1850 AD). 2) Pb and Cd are related to anthropogenic pollution and demonstrate industrial sourced trends throughout the anthropocene (since 1750 AD). 3) Terrogenous elements, including Fe, Al, Mn and V. Al in seawater and sediments has been used to trace water masses and land derived sediment source. We observe a major change in average vermetid Al/Fe ratios from 0.5 to 2.5 over the recorded period (n=72). This vermetid Al/Fe change points at a possible shift from Nilotic sediments (0.1-0.5 Al/Fe molar ratio) to Saharan dust ratio (2-4 Al/Fe molar ratio). Mn and V show a similar variability to Fe. Understanding the variability of vermetid TE can help us interpret the relative

Evaluation of trace element status of food articles

International Nuclear Information System (INIS)

Qureshi, I.H.; Ahmad, S.; Zaidi, S.J.; Mannan, A.; Waheed, S.; Fatima, I.; Arif, M.; Rahman, A.

1996-01-01

Food is the main source of major, minor and micro nutrients required for human beings. Food articles, due to environmental pollution may also contain some toxic elements which would adversely affect their health. In order to assess the adequacy and safety of human diet main food items were analyzed for the measurement of essential and toxic trace elements employing neutron activation analysis and atomic absorption spectrometry. The data so obtained will serve as baseline values and will be helpful to monitor the changes in the trace element contents of these items in future. The dietary intake of essential and toxic trace elements through these items was estimated and compared with the recommended values. This study indicates that the intake of essential elements except for co is fairly adequate and that of toxic elements in well well within the permissible limits. (author)

Problems of accuracy and sources of error in trace analysis of elements

International Nuclear Information System (INIS)

Porat, Ze'ev.

1995-07-01

The technological developments in the field of analytical chemistry in recent years facilitates trace analysis of materials in sub-ppb levels. This provides important information regarding the presence of various trace elements in the human body, in drinking water and in the environment. However, it also exposes the measurements to more severe problems of contamination and inaccuracy due to the high sensitivity of the analytical methods. The sources of error are numerous and can be included in three main groups: (a) impurities of various sources; (b) loss of material during sample processing; (c) problems of calibration and interference. These difficulties are discussed here in detail, together with some practical solutions and examples.(authors) 8 figs., 2 tabs., 18 refs.,

Problems of accuracy and sources of error in trace analysis of elements

Energy Technology Data Exchange (ETDEWEB)

Porat, Ze` ev

1995-07-01

The technological developments in the field of analytical chemistry in recent years facilitates trace analysis of materials in sub-ppb levels. This provides important information regarding the presence of various trace elements in the human body, in drinking water and in the environment. However, it also exposes the measurements to more severe problems of contamination and inaccuracy due to the high sensitivity of the analytical methods. The sources of error are numerous and can be included in three main groups: (a) impurities of various sources; (b) loss of material during sample processing; (c) problems of calibration and interference. These difficulties are discussed here in detail, together with some practical solutions and examples.(authors) 8 figs., 2 tabs., 18 refs.,.

RAY TRACING IMPLEMENTATION IN JAVA PROGRAMMING LANGUAGE

Directory of Open Access Journals (Sweden)

Aybars UĞUR

2002-01-01

Full Text Available In this paper realism in computer graphics and components providing realism are discussed at first. It is mentioned about illumination models, surface rendering methods and light sources for this aim. After that, ray tracing which is a technique for creating two dimensional image of a three-dimensional virtual environment is explained briefly. A simple ray tracing algorithm was given. "SahneIzle" which is a ray tracing program implemented in Java programming language which can be used on the internet is introduced. As a result, importance of network-centric ray tracing software is discussed.

Use of biomimetic forward osmosis membrane for trace organics removal

DEFF Research Database (Denmark)

Madsen, Henrik T.; Bajraktari, Niada; Helix Nielsen, Claus

2015-01-01

The use of forward osmosis for the removal of trace organics from water has recently attracted considerable attention as an alternative to traditional pressure driven membrane filtration. However, the existing forward osmosis membranes have been found to be ineffective at rejecting small neutral...... organic pollutants, which limits the applicability of the forward osmosis process. In this study a newly developed biomimetic membrane was tested for the removal of three selected trace organics that can be considered as a bench marking test for a membrane[U+05F3]s ability to reject small neutral organic....... This difference is caused by differences in the transport mechanisms. For the cellulose acetate membrane rejection is controlled by steric hindrance, which results in a size dependent rejection of the trace organics, whereas rejection by the aquaporin membrane is controlled by diffusion of the trace organics...

Trace Elements in Hair from Tanzanian Children: Effect of Dietary Factor

International Nuclear Information System (INIS)

Mohammed, Najat K.; Spyrou, Nicholas M.

2009-01-01

Trace elements in certain amounts are essential for childrens' health, because they are present in tissues participating in metabolic reactions of organisms. Deficiency of the essential elements may result in malnutrition, impaired body immunity, and poor resistance to disease. These conditions might be enhanced against a background of additional adverse environmental factors such as toxic elements. The analysis of elements in childrens' hair will give information on the deficiency of essential elements and excess of toxic elements in relation to their diet. In this study, 141 hair samples from children (girls and boys) living in two regions of Tanzanian mainland (Dar es Salaam and Moshi) and the island of Zanzibar have been analysed for trace elements in relation to food consumption habits. The analysis was carried out using long and short irradiation instrumental neutron activation analysis (INAA) of the Nuclear Physics Institute at Rez, Czech Republic. Arithmetic and geometric means with their respective standard deviations are presented for 19 elements. Subgroups were formed according to age, gender, and geographic regions from which the samples were collected. Differences in concentrations for the groups and with other childhood populations were explored and discussed.

Bite traces in a turtle carapace fragment from the middle Danian (Lower Paleocene) bryozoan limestone, Faxe, Denmark

DEFF Research Database (Denmark)

Milan, Jesper; Lindow, Bent Erik Kramer; Lauridsen, Bodil Wesenberg

2011-01-01

A fragment of a turtle carapace from the Middle Danian bryozoan limestone at the Faxe quarry, eastern Denmark, is identified as a partial costal plate from the carapace of a chelonioid turtle. The fragment bears traces of three separate acts of predation or scavenging. Two circular bite traces Ni...... either alone or in a row of three, are either from sharks or fish. This is the first record of turtles from the Danian bryozoan limestone exposed in Faxe....... Nihilichnus nihilicus Mikuláš et al. 2006, 4 mm in diameter, situated 2.5 cm apart, are interpreted as crocodylian. Groups of parallel scrapes, Machichnus bohemicus Mikuláš et al. 2006, 4–5 mm long and 0.5 mm wide, are interpreted as bite traces from sharks. Small circular traces, ~1 mm in diameter, found...

Trace metal physiology in normal and pathological tissues

International Nuclear Information System (INIS)

Hamer, C.J.A. van den; Nooijen, J.L.

1979-01-01

Many of the ionic tumour seeking radiopharmaceuticals consist of a metal ion combined with an anion. The choice of metal depends on the existence of radionuclides with suitable radiological properties, and on their availability. Because several of the metal complexes used in nuclear medicine are of rather recent interest, information about their metabolism is scarce. Although nuclear medicine is limited to those metals which radiochemists can produce, we can manipulate the chemical form in which the metals are introduced into the organism to some extent. The relation between chemical form and biological pathway, e.g., the extent of accumulation in certain tissues, is subject of study related to trace metal physiology. It is the purpose of this paper to try and bridge the gap between nuclear medicine and trace metal physiology by showing the progress made by the latter in the study of the metabolism of copper and zinc. Few trace metals have been studied as thoroughly as these, although iron could have been chosen just as well. This presentation is limited to a study of the fate of a metal derivative after its intravenous injection. Where possible the results obtained are related to the behaviour of metals presently of interest to nuclear medicine. (Auth.)

Chemometric Study of Trace Elements in Hard Coals of the Upper Silesian Coal Basin, Poland

Science.gov (United States)

Rompalski, Przemysław; Cybulski, Krzysztof; Chećko, Jarosław

2014-01-01

The objective of the study was the analysis of trace elements contents in coals of the Upper Silesian Coal Basin (USCB), which may pose a potential threat to the environment when emitted from coal processing systems. Productive carbon overburden in central and southern zones of the USCB is composed mostly of insulating tertiary formations of a thickness from a few m to 1,100 m, and is represented by Miocene and Pliocene formations. In the data study the geological conditions of the coal seams of particular zones of the USCB were taken into account and the hierarchical clustering analysis was applied, which enabled the exploration of the dissimilarities between coal samples of various zones of the USCB in terms of basic physical and chemical parameters and trace elements contents. Coals of the northern and eastern zones of the USCB are characterized by high average Hg and low average Ba, Cr, and Ni contents, whereas coals of southern and western zones are unique due to high average concentrations of Ba, Co, Cu, Ni, and V. Coals of the central part of the USCB are characterized by the highest average concentration of Mn and the lowest average concentrations of As, Cd, Pb, V, and Zn. PMID:24967424

Trace element geochemistry of the South Atlantic Bight. Progress report

International Nuclear Information System (INIS)

Windom, H.L.; Wallace, G.T.

1980-03-01

This report summarizes research conducted during the past year under DOE Contract EY-76-S-09-0890. During this time, studies have been continued in the mid to outer continental shelf region. We have also initiated nearshore studies designed to elucidate processes influencing the fate of trace elements in estuaries and the coastal frontal zone. A smaller effort has been concerned with preliminary geochemical studies of uranium-thorium natural decay series radionuclides and with improvement, calibration, and expansion of our trace element laboratory procedures

Intraoral gothic arch tracing.

Science.gov (United States)

Rubel, Barry; Hill, Edward E

2011-01-01

In order to create optimum esthetics, function and phonetics in complete denture fabrication, it is necessary to record accurate maxillo-mandibular determinants of occlusion. This requires clinical skill to establish an accurate, verifiable and reproducible vertical dimension of occlusion (VDO) and centric relation (CR). Correct vertical relation depends upon a consideration of several factors, including muscle tone, inter-dental arch space and parallelism of the ridges. Any errors made while taking maxillo-mandibular jaw relation records will result in dentures that are uncomfortable and, possibly, unwearable. The application of a tracing mechanism such as the Gothic arch tracer (a central bearing device) is a demonstrable method of determining centric relation. Intraoral Gothic arch tracers provide the advantage of capturing VDO and CR in an easy-to-use technique for practitioners. Intraoral tracing (Gothic arch tracing) is a preferred method of obtaining consistent positions of the mandible in motion (retrusive, protrusive and lateral) at a comfortable VDO.

From trace chemistry to single atom chemistry

International Nuclear Information System (INIS)

Adloff, J.P.

1993-01-01

Hot atom chemistry in the vast majority of experimental works deals with the trace amount of radioactive matters. Accordingly, the concept of trace chemistry is at the heart of hot atom chemistry. Some aspects of the chemistry at trace scale and at subtrace scale are presented together with the related problems of speciation and the complication which may arise due to the formation of radio colloids. The examples of 127 I(n,γ) 128 I and 132 Te (β - ) 132 I are shown, and the method based on radioactivity was used. The procedure of separating the elements in pitchblende is shown as the example of the chemistry of traces. 13 27 Al+ 2 4 He→ 0 1 n+ 15 30 P and 15 30 P→ 14 30 Si+e + +V are shown, and how to recognize the presence of radioactive colloids is explained. The formation of radiocolloids is by the sorption of a trace radioelement on pre-existing colloidal impurity or the self-condensation of monomeric species. The temporal parameters of the nature of reactions at trace concentration are listed. The examples of Class A and Class B reactions are shown. The kinetics of reactions at trace level, radon concentration, anthropogenic Pu and natural Pu in environment, the behavior of Pu atoms and so on are described. (K.I.)

Relationship between blood groups and male infertility

International Nuclear Information System (INIS)

Ahmed, I.; Naeem, M.; Samad, A.; Nasir, A.; Aman, Z.; Ahmed, S.; Manan, F.

2010-01-01

Background: Blood is man's complete and unchangeable identity. The ABO and Rh groups are recognised as major and clinically significant blood groups. Blood group antigens are not only important in relation to blood transfusion and organ transplantation, but also have been utilised in genetic research, anthropology and tracing ancestral relation of humans. The objective the present study is to examine the blood group antigens in infertile men for assessing the relationship to male infertility and to know the frequency of various blood groups among infertile males in our population. Method: A total of 1,521 patients along with 460 proven fathers as controls were recruited for the present study from both rural and urban areas of Pakistan and referred to Department of Reproductive Physiology/Health, Public Health Divisions, NIH, Islamabad, during 2002 to 2006. Blood grouping (ABO) and Rhesus factors (Rh) was done by the antigen antibody agglutination test. Results: Overall distribution of blood groups in the studied population of 1,521 subjects was 35.50%, 28.27%, 26.89% and 9.34% for blood groups O, B, A and AB respectively. The ratio of control to patient was 1:3.3. Conclusions: The present preliminary study revealed that in our population the prevalence of male infertility in blood group O is invariably higher than in all other ABO blood groups, showing a strong relationship between blood group O and male infertility. (author)

Trace element distribution in different chemical fractions of False Bay sediments

International Nuclear Information System (INIS)

Rosental, R.

1984-05-01

Trace metals in the aquatic environment are generally concentrated on solid geochemical phases which eventually become incorporated into estuarine and marine sediments. The mechanism of trace metal concentration is believed to be adsorption on various geochemical phases, such as hydrous metal oxides, clays and organic matter. Metals in estuarine sediments can thus be expected to be partitioned between different phases, depending on the concentration of the phase and the strength of the adsorption bond. The bioavailability of sediment-bound metals to deposit-feeding organisms will depend on trace metal partitioning and the kinetics of biological metal uptake from each geochemical phase. The major objective of this study was to establish an analytical procedure involving sequential chemical extractions for the partitioning of particulate trace metals in sediment samples, collected from False Bay. Eight metals were examined, i.e. Cd, Cu, Cr, Fe, Mn, Ni, Pb and Zn. X-ray diffraction was also used in the study

Monitoring of trace metals and pharmaceuticals as anthropogenic and socio-economic indicators of urban and industrial impact on surface waters

Science.gov (United States)

Vystavna, Yuliya

2014-05-01

The research focuses on the monitoring of trace metals and pharmaceuticals as potential anthropogenic indicators of industrial and urban influences on surface water in poorly gauged transboundary Ukraine/Russia region. This study includes analysis of tracers use for the indication of water pollution events, including controlled and emerging discharges, and discussion of the detection method of these chemicals. The following criteria were proposed for the evaluation of indicators: specificity (physical chemical properties), variability (spatial and temporal) and practicality (capacity of the sampling and analytical techniques). The combination of grab and passive water sampling (i.e. DGT and POCIS) procedure was applied for the determination of dissolved and labile trace metals (Ag, Cd, Cr, Cu, Ni, Pb and Zn) and pharmaceuticals (carbamazepine, diazepam, paracetamol, caffeine, diclofenac and ketoprofen). Samples were analysed using ICP - MS (trace metals) and LC-MS/MS ESI +/- (pharmaceuticals). Our results demonstrate the distinctive spatial and temporal patterns of trace elements distribution along an urban watercourse. Accordingly, two general groups of trace metals have been discriminated: 'stable' (Cd and Cr) and 'time-varying' (Cu, Zn, Ni and Pb). The relationship Cd >> Cu > Ag > Cr ≥ Zn was proposed as an anthropogenic signature of the industrial and urban activities pressuring the environment from point sources (municipal wastewaters) and the group Pb - Ni was discussed as a relevant fingerprint of the economic activity (industry and transport) mainly from non-point sources (run-off, atmospheric depositions, etc.). Pharmaceuticals with contrasting hydro-chemical properties of molecules (water solubility, bioaccumulation, persistence during wastewater treatment processes) were discriminated on conservative, labile and with combined properties in order to provide information on wastewater treatment plant efficiency, punctual events (e.g. accidents on sewage

Heavy metals and related trace elements

International Nuclear Information System (INIS)

Leland, H.V.; Luoma, S.N.; Wilkes, D.J.

1977-01-01

A review is given of heavy metals and related trace elements in the aquatic environment. Other reviews and bibliographies are cited, dealing with the metabolism and transport of metal ions and with the toxic effects of stable and radioactive trace metals on aquatic organisms. The sources of trace elements in natural waters are discussed. It is suggested that atmospheric inputs of several trace metals comprise sizable fractions of total inputs to the Great Lakes and continental shelf waters. Information on stack emissions of trace elements from a coal-fired steam plant was used to estimate the likely range of air concentrations and inputs to a forested watershed in Tennessee. Some basic concepts of cycling of elements through aquatic communities were examined, such as the Pb, Mn and Zn concentrations in sediment and estuarine plants and animals colonizing dredge-spoil disposal areas. The use of plants as biological indicators of trace element contamination was outlined, as well as bioaccumulation in aquatic fauna. The effects of environmental factors on the kinetics of element exchange were noted, for example the influx rates of Cs 137 in tubificid worms, and Co 60 and Zn 65 in shrimp were shown to be temperature dependent. The toxicity of heavy metals on aquatic fauna was discussed, such as the histopathological lesions in the kidney and liver of fishes caused by heavy metals, and the effects of Hg and Cu on the olfactory response of rainbow trout

Unmanned Aerial Systems for Monitoring Trace Tropospheric Gases

Directory of Open Access Journals (Sweden)

Travis J. Schuyler

2017-10-01

Full Text Available The emission of greenhouse gases (GHGs has changed the composition of the atmosphere during the Anthropocene. Accurately documenting the sources and magnitude of GHGs emission is an important undertaking for discriminating the contributions of different processes to radiative forcing. Currently there is no mobile platform that is able to quantify trace gases at altitudes <100 m above ground level that can achieve spatiotemporal resolution on the order of meters and seconds. Unmanned aerial systems (UASs can be deployed on-site in minutes and can support the payloads necessary to quantify trace gases. Therefore, current efforts combine the use of UASs available on the civilian market with inexpensively designed analytical systems for monitoring atmospheric trace gases. In this context, this perspective introduces the most relevant classes of UASs available and evaluates their suitability to operate three kinds of detectors for atmospheric trace gases. The three subsets of UASs discussed are: (1 micro aerial vehicles (MAVs; (2 vertical take-off and landing (VTOL; and, (3 low-altitude short endurance (LASE systems. The trace gas detectors evaluated are first the vertical cavity surface emitting laser (VCSEL, which is an infrared laser-absorption technique; second two types of metal-oxide semiconductor sensors; and, third a modified catalytic type sensor. UASs with wingspans under 3 m that can carry up to 5 kg a few hundred meters high for at least 30 min provide the best cost and convenience compromise for sensors deployment. Future efforts should be focused on the calibration and validation of lightweight analytical systems mounted on UASs for quantifying trace atmospheric gases. In conclusion, UASs offer new and exciting opportunities to study atmospheric composition and its effect on weather patterns and climate change.

Using column experiments to examine transport of As and other trace elements released from poultry litter: Implications for trace element mobility in agricultural watersheds.

Science.gov (United States)

Oyewumi, Oluyinka; Schreiber, Madeline E

2017-08-01

Trace elements are added to poultry feed to control infection and improve weight gain. However, the fate of these trace elements in poultry litter is poorly understood. Because poultry litter is applied as fertilizer in many agricultural regions, evaluation of the environmental processes that influence the mobility of litter-derived trace elements is critical for predicting if trace elements are retained in soil or released to water. This study examined the effect of dissolved organic carbon (DOC) in poultry litter leachate on the fate and transport of litter-derived elements (As, Cu, P and Zn) using laboratory column experiments with soil collected from the Delmarva Peninsula (Mid-Atlantic, USA), a region of intense poultry production. Results of the experiments showed that DOC enhanced the mobility of all of the studied elements. However, despite the increased mobility, 60-70% of Zn, As and P mass was retained within the soil. In contrast, almost all of the Cu was mobilized in the litter leachate experiments, with very little retention in soil. Overall, our results demonstrate that the mobility of As, Cu, Zn and P in soils which receive poultry litter application is strongly influenced by both litter leachate composition, specifically organic acids, and adsorption to soil. Results have implications for understanding fate and transport of trace elements released from litter application to soil water and groundwater, which can affect both human health and the environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Proton induced X-Ray fluorescence study as a tool trace element analysis

International Nuclear Information System (INIS)

El-Kady, Ahmed A.

1978-01-01

Usefulness and limitations of trace elemental analysis by high energy charged particles and photon induced X-ray have been discussed. Comparison with the well established neutron activation analysis technique is also given. Back-ground radiation due to bremsstrahlung from secondary electrons and due to charged particle bremsstrahlung have been reviewed for different projectiles. The sensitivity of elemental analysis by proton induced X-ray fluorescence have been examined by measuring the characteristic X-ray emission cross section for K and L transitions of many elements and for different proton energies and compared with theroretical values. The discussion given in this report show that with suitable proton generator and a high resolution X-ray detector, proton X-ray fluorescence technique is capable of analyzing many elements simultaneously at the part per million level and offers a rapid and reliable method for trace element analysis. Data on water, blood and tissue samples given in this report are few examples of many possible applications

Sources of trace elements in total diet. A statistical approach

International Nuclear Information System (INIS)

Aras, N.K.; Chatt, A.

2004-01-01

Sixteen total diet samples have been collected from two socioeconomic groups in Turkey by duplicate portion techniques. Samples were homogenized with titanium-blade homogenizer, freeze dried and analyzed for their minor and trace elements mostly by neutron activation analysis. Bread and flour samples were also collected from the same regions and analyzed similarly by instrumental neutron activation analysis. Concentrations of more than 25 elements in total diets, bread and flour, and fiber and phytate in total diets have been determined. Daily dietary intakes of these population groups, probable source of elements through correlation coefficients, and enrichment factor calculations have been determined. (author)

Fate of alkali and trace metals in biomass gasification

International Nuclear Information System (INIS)

Salo, K.; Mojtahedi, W.

1998-01-01

The fate of alkali metals (Na, K) and eleven toxic trace elements (Hg, Cd, Be, Se, Sb, As, Pb, Zn, Cr, Co, Ni) in biomass gasification have been extensively investigated in Finland in the past ten years. The former due to the gas turbine requirements and the latter to comply with environmental regulations. In this paper the results of several experimental studies to measure Na and K in the vapor phase after the gas cooler of a simplified (air-blown) Integrated Gasification Combined-Cycle (IGCC) system are reported. Also, trace element emissions from an IGCC plant using alfalfa as the feedstock are discussed and the concentration of a few toxic trace metals in the vapor phase in the gasifier product gas are reported. (author)

[Trace elements of bone tumors].

Science.gov (United States)

Kalashnikov, V M; Zaĭchik, V E; Bizer, V A

1983-01-01

Due to activation analysis involving the use of neutrons from a nuclear reactor, the concentrations of 11 trace elements: scandium, iron, cobalt, mercury, rubidium, selenium, silver, antimony, chrome, zinc and terbium in intact bone and skeletal tumors were measured. 76 specimens of bioptates and resected material of operations for bone tumors and 10 specimens of normal bone tissue obtained in autopsies of cases of sudden death were examined. The concentrations of trace elements and their dispersion patterns in tumor tissue were found to be significantly higher than those in normal bone tissue. Also, the concentrations of some trace elements in tumor differed significantly from those in normal tissue; moreover, they were found to depend on the type and histogenesis of the neoplasm.

Ray Tracing for Real-time Games

NARCIS (Netherlands)

Bikker, J.

2012-01-01

This thesis describes efficient rendering algorithms based on ray tracing, and the application of these algorithms to real-time games. Compared to rasterizationbased approaches, rendering based on ray tracing allows elegant and correct simulation of important global effects, such as shadows,

Modeling of contact tracing in social networks

Science.gov (United States)

Tsimring, Lev S.; Huerta, Ramón

2003-07-01

Spreading of certain infections in complex networks is effectively suppressed by using intelligent strategies for epidemic control. One such standard epidemiological strategy consists in tracing contacts of infected individuals. In this paper, we use a recently introduced generalization of the standard susceptible-infectious-removed stochastic model for epidemics in sparse random networks which incorporates an additional (traced) state. We describe a deterministic mean-field description which yields quantitative agreement with stochastic simulations on random graphs. We also discuss the role of contact tracing in epidemics control in small-world and scale-free networks. Effectiveness of contact tracing grows as the rewiring probability is reduced.

Trace elements in groundwater used for water supply in Latvia

Science.gov (United States)

Retike, Inga; Kalvans, Andis; Babre, Alise; Kalvane, Gunta; Popovs, Konrads

2014-05-01

Latvia is rich with groundwater resources of various chemical composition and groundwater is the main drinking source. Groundwater quality can be easily affected by pollution or overexploitation, therefore drinking water quality is an issue of high importance. Here the first attempt is made to evaluate the vast data base of trace element concentrations in groundwater collected by Latvian Environment, Geology and Meteorology Centre. Data sources here range from National monitoring programs to groundwater resources prospecting and research projects. First available historical records are from early 1960, whose quality is impossible to test. More recent systematic research has been focused on the agricultural impact on groundwater quality (Levins and Gosk, 2007). This research was mainly limited to Quaternary aquifer. Monitoring of trace elements arsenic, cadmium and lead was included in National groundwater monitoring program of Latvia in 2008 and 2009, but due to lack of funding the monitoring was suspended until 2013. As a result there are no comprehensive baseline studies regarding the trace elements concentration in groundwater. The aim of this study is to determine natural major and trace element concentration in aquifers mainly used for water supply in Latvia and to compare the results with EU potable water standards. A new overview of artesian groundwater quality will be useful for national and regional planning documents. Initial few characteristic traits of trace element concentration have been identified. For example, elevated fluorine, strontium and lithium content can be mainly associated with gypsum dissolution, but the highest barium concentrations are found in groundwaters with low sulphate content. The groundwater composition data including trace element concentrations originating from heterogeneous sources will be processed and analyzed as a part of a newly developed geologic and hydrogeological data management and modeling system with working name

The transition region and coronal explorer (TRACE)

Science.gov (United States)

Title, Alan; Bruner, M.; Jurcevich, B.; Lemen, J.; Strong, K.; Tarbell, Ted; Wolfson, C. Jacob; Golub, L.; Bookbinder, J.; Fisher, R.

1995-01-01

The transition region and coronal explorer (TRACE) NASA small explorer mission and instrument are presented. The TRACE scientific investigation explores the relationships between fine-scale magnetic fields and the associated solar plasma structures. The instrument collects images of solar plasmas at temperatures from 10(exp 4) to 10(exp 7) K with one arcsec spatial resolution. The design specifications of the trace instrument are presented.

Microscopic study of gum-metal alloys: A role of trace oxygen for dislocation-free deformation

International Nuclear Information System (INIS)

Nagasako, Naoyuki; Asahi, Ryoji; Isheim, Dieter; Seidman, David N.; Kuramoto, Shigeru; Furuta, Tadahiko

2016-01-01

A class of Ti–Nb–Ta–Zr–O alloys called gum metal are known to display high strength, low Young's modulus and high elastic deformability up to 2.5%, simultaneously, and considered to deform by a dislocation-free deformation mechanism. A trace of oxygen (∼1%) in gum metal is indispensable to realize such significant properties; however, the detailed mechanism and the role of the oxygen has not been understood. To investigate an effect of trace oxygen included in gum metal, first-principles calculations for gum-metal approximants including zirconium and oxygen are performed. Calculated results clearly indicate that oxygen site with less neighboring Nb atom is energetically favorable, and that Zr–O bonding has an important role to stabilize the bcc structure of gum metal. The three-dimensional atom-probe tomography (3-D APT) measurements for gum metal were also performed to identify compositional inhomogeneity attributed to the trace elements. From the 3-D APT measurements, Zr ions bonding with oxygen ions are observed, which indicates existence of Zr–O nano-clusters in gum metal. Consequently, it is found that (a) coexistence of Zr atom and oxygen atom improves elastical stability of gum metal, (b) inhomogeneous distribution of the compositions induced by the trace elements causes anisotropical change of shear moduli, and (c) Zr–O nano-clusters existing in gum metal are expected to be obstacles to suppress movemen of dislocations.

Can liming change root anatomy, biomass allocation and trace element distribution among plant parts of Salix × smithiana in trace element-polluted soils?

Science.gov (United States)

Vondráčková, Stanislava; Tlustoš, Pavel; Száková, Jiřina

2017-08-01

Willows (Salix spp.) are considered to be effective for the phytoremediation of trace elements from contaminated soils, but their efficiency is limited in heavily polluted soils because of poor growth. Liming can be a desirable measure to decrease the plant availability of elements, resulting in improved plant development. Notably, large root area and maximum soil penetration are basic parameters that improve the efficiency of phytoremediation. The impact of soil chemical properties on willow root anatomy and the distribution of trace elements below-ground have rarely been studied. The effect of liming on root parameters, biomass allocation and trace element distribution in non-harvestable (coarse roots, fine roots, stumps) and harvestable plant parts (twigs and leaves) of Salix × smithiana was assessed at the end of a 4-year pot experiment with two trace element-polluted soils that differed in terms of soil pH. Stump biomass predominated in weakly acidic soil. In neutral soil, the majority of biomass was located in fine roots and stumps; the difference from other plant parts was minor. Trace elements were the most concentrated in fine roots. Translocation to above-ground biomass increased as follows: Pb roots roots). Lime application decreased the concentrations of mobile Cd and Zn and related levels in plants, improved biomass production and root parameters and increased the removal of all trace elements in weakly acidic soil. None or minimum differences in the monitored parameters were recorded for dolomite treatments in both soils. The dose and source of liming had crucial effects on root anatomy. Growing willows in limed trace element-polluted soils is a suitable measure for combination of two remediation strategies, i.e. phytoextraction of Cd and Zn and assisted phytostabilization of As and Pb.

Chemometric evaluation of trace elements in Brazilian medicinal plants

International Nuclear Information System (INIS)

Silva, Paulo S.C. da; Francisconi, Lucilaine S.; Goncalves, Rodolfo D.M.R.

2013-01-01

The growing interest in herbal medicines has required standardization in order to ensure their safe use, therapeutic efficacy and quality of the products. Despite the vast flora and the extensive use of medicinal plants by the Brazilian population, scientific studies on the subject are still insufficiency In this study, 59 medicinal plans were analyzed for the determination of As, Ba, Br, Ca, Cl, Cs, Co, Cr, Fe, Hf, K, Mg, Mn, Na, Rb, Sb, Sc, Se, Ta, Th, U, Zn and Zr by neutron activation analysis and Cu, Ni, Pb, Cd and Hg by atomic absorption. The results were analyzed by chemometric methods: correlation analysis, principal component analysis and cluster analysis, in order to verify whether or not there is similarity with respect to their mineral and trace metal contents. Results obtained permitted to classify distinct groups among the analyzed plants and extracts so that these data can be useful in future studies, concerning the therapeutic action the elements here determined may exert. (author)

Chemometric evaluation of trace elements in Brazilian medicinal plants

Energy Technology Data Exchange (ETDEWEB)

Silva, Paulo S.C. da; Francisconi, Lucilaine S.; Goncalves, Rodolfo D.M.R., E-mail: pscsilva@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro do Reator de Pesquisas

2013-07-01

The growing interest in herbal medicines has required standardization in order to ensure their safe use, therapeutic efficacy and quality of the products. Despite the vast flora and the extensive use of medicinal plants by the Brazilian population, scientific studies on the subject are still insufficiency In this study, 59 medicinal plans were analyzed for the determination of As, Ba, Br, Ca, Cl, Cs, Co, Cr, Fe, Hf, K, Mg, Mn, Na, Rb, Sb, Sc, Se, Ta, Th, U, Zn and Zr by neutron activation analysis and Cu, Ni, Pb, Cd and Hg by atomic absorption. The results were analyzed by chemometric methods: correlation analysis, principal component analysis and cluster analysis, in order to verify whether or not there is similarity with respect to their mineral and trace metal contents. Results obtained permitted to classify distinct groups among the analyzed plants and extracts so that these data can be useful in future studies, concerning the therapeutic action the elements here determined may exert. (author)

Contact tracing with a real-time location system: A case study of increasing relative effectiveness in an emergency department.

Science.gov (United States)

Hellmich, Thomas R; Clements, Casey M; El-Sherif, Nibras; Pasupathy, Kalyan S; Nestler, David M; Boggust, Andy; Ernste, Vickie K; Marisamy, Gomathi; Koenig, Kyle R; Hallbeck, M Susan

2017-12-01

Contact tracing is the systematic method of identifying individuals potentially exposed to infectious diseases. Electronic medical record (EMR) use for contact tracing is time-consuming and may miss exposed individuals. Real-time location systems (RTLSs) may improve contact identification. Therefore, the relative effectiveness of these 2 contact tracing methodologies were evaluated. During a pertussis outbreak in the United States, a retrospective case study was conducted between June 14 and August 31, 2016, to identify the contacts of confirmed pertussis cases, using EMR and RTLS data in the emergency department of a tertiary care medical center. Descriptive statistics and a paired t test (α = 0.05) were performed to compare contacts identified by EMR versus RTLS, as was correlation between pertussis patient length of stay and the number of potential contacts. Nine cases of pertussis presented to the emergency department during the identified time period. RTLS doubled the potential exposure list (P < .01). Length of stay had significant positive correlation with contacts identified by RTLS (ρ = 0.79; P = .01) but not with EMR (ρ = 0.43; P = .25). RTLS doubled the potential pertussis exposures beyond EMR-based contact identification. Thus, RTLS may be a valuable addition to the practice of contact tracing and infectious disease monitoring. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Attachment GEO 1 Permic basin geology in northeast of Uruguay: deposit exam about Uranium traces

International Nuclear Information System (INIS)

L'Homer, A.; Manigault, B; Doyhenart, A.; Rossi, P.

1983-01-01

The article is about different deposit of Uranium traces and their Sedimentology analysis. A revision of main works have been given and Durazno and Gondwana groups, Cerrezuelo, Cordobes, La Paloma, San Gregorio, Tres Islas formations

A study of trace element concentrations in human hair of some local populations in Japan. II. Inhabitants of a Japanese rural area

International Nuclear Information System (INIS)

Sakurai, S.; Tsunoda, H.; Terai, M.; Yukawa, M.; Tomura, K.; Suzuki-Yasumoto, M.

1979-01-01

Hair, as a route by which many metals are excreted, has advantages over other tissues as an indicator of body burden. However, as few data exist on trace element concentrations in hair, a study was made on a rural population in Japan. Hair was collected from 107 residents engaged mainly in dairy farming in a rural area in the northern part of the country. Samples were taken from subjects who had been born and bred in the area which is believed to be free from environmental pollution. A large number of the families had lived there for generations. Nineteen trace elements were detected. The mean values for Hg in hair were 6.8+-2.9 ppm for males and 4.5+-2.7 ppm for females. There was a low statistical correlation between Hg and Se. The mean value for Cu in hair was 17+-7.2 ppm for males and 16+-5.7 ppm for females and that for Zn was 140+-61 ppm for males and 130+-63 ppm for females. A comparison of the mean values of the trace elements in the hair of the subjects aged 20-39 and 40-59 years showed significant differences for Mn in males and Mn and Br in females. A comparison of the findings for the two sexes showed that the concentrations of Mn, Mg, Ca and Br were much higher in females than in males. In contrast, the concentrations of Hg were higher in males than in females. It is suggested that the values obtained for the trace elements in the present study are examples of normal values for trace elements in hair of the Japanese populations. (author)

DNA profiling of trace DNA recovered from bedding.

Science.gov (United States)

Petricevic, Susan F; Bright, Jo-Anne; Cockerton, Sarah L

2006-05-25

Trace DNA is often detected on handled items and worn clothing examined in forensic laboratories. In this study, the potential transfer of trace DNA to bedding by normal contact, when an individual sleeps in a bed, is examined. Volunteers slept one night on a new, lower bed sheet in their own bed and one night in a bed foreign to them. Samples from the sheets were collected and analysed by DNA profiling. The results indicate that the DNA profile of an individual can be obtained from bedding after one night of sleeping in a bed. The DNA profile of the owner of the bed could also be detected in the foreign bed experiments. Since mixed DNA profiles can be obtained from trace DNA on bedding, caution should be exercised when drawing conclusions from DNA profiling results obtained from such samples. This transfer may have important repercussions in sexual assault investigations.

Women Empowerment Through Self-Help Groups

NARCIS (Netherlands)

Alemu, Sintayehu Hailu; Kempen, Van Luuk; Ruben, Ruerd

2018-01-01

This paper deals with the impact of self-help groups (SHGs) in apple production on empowering women in the Chencha district of Southern Ethiopia. Impact is traced on the basis of a cross-sectional survey among SHG members and nonmembers, using propensity score matching. Apart from the attitudinal

Atom trap trace analysis

International Nuclear Information System (INIS)

Lu, Z.-T.; Bailey, K.; Chen, C.-Y.; Du, X.; Li, Y.-M.; O'Connor, T. P.; Young, L.

2000-01-01

A new method of ultrasensitive trace-isotope analysis has been developed based upon the technique of laser manipulation of neutral atoms. It has been used to count individual 85 Kr and 81 Kr atoms present in a natural krypton sample with isotopic abundances in the range of 10 -11 and 10 -13 , respectively. The atom counts are free of contamination from other isotopes, elements,or molecules. The method is applicable to other trace-isotopes that can be efficiently captured with a magneto-optical trap, and has a broad range of potential applications

The research of electrical tracing system construction management and related questions of BOP project

International Nuclear Information System (INIS)

Wang Lining; Li Jingmin; Ma Ding; Tu Haitao

2015-01-01

Based on Hongyanhe nuclear power plant in Liaoning province, the paper studies the anti-freeze and heat tracing work of BOP project. It compares several different heat tracing solutions in terms of technicality and applicability, and gave the most suitable scheme by using electrical tracing. It also presents the construction details of the electrical tracing system, analyzes the key points of the construction management from quantity, safety and schedule aspects, and gave the improvement suggestions. (authors)

Trace element contamination in feather and tissue samples from Anna’s hummingbirds

Science.gov (United States)

Mikoni, Nicole A.; Poppenga, Robert H.; Ackerman, Joshua T.; Foley, Janet E.; Hazlehurst, Jenny; Purdin, Güthrum; Aston, Linda; Hargrave, Sabine; Jelks, Karen; Tell, Lisa A.

2017-01-01

Trace element contamination (17 elements; Be, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Ba, Hg, Tl, and Pb) of live (feather samples only) and deceased (feather and tissue samples) Anna's hummingbirds (Calypte anna) was evaluated. Samples were analyzed using inductively coupled plasma-mass spectrometry (ICP-MS; 17 elements) and atomic absorption spectrophotometry (Hg only). Mean plus one standard deviation (SD) was considered the benchmark, and concentrations above the mean + 1 SD were considered elevated above normal. Contour feathers were sampled from live birds of varying age, sex, and California locations. In order to reduce thermal impacts, minimal feathers were taken from live birds, therefore a novel method was developed for preparation of low mass feather samples for ICP-MS analysis. The study found that the novel feather preparation method enabled small mass feather samples to be analyzed for trace elements using ICP-MS. For feather samples from live birds, all trace elements, with the exception of beryllium, had concentrations above the mean + 1 SD. Important risk factors for elevated trace element concentrations in feathers of live birds were age for iron, zinc, and arsenic, and location for iron, manganese, zinc, and selenium. For samples from deceased birds, ICP-MS results from body and tail feathers were correlated for Fe, Zn, and Pb, and feather concentrations were correlated with renal (Fe, Zn, Pb) or hepatic (Hg) tissue concentrations. Results for AA spectrophotometry analyzed samples from deceased birds further supported the ICP-MS findings where a strong correlation between mercury concentrations in feather and tissue (pectoral muscle) samples was found. These study results support that sampling feathers from live free-ranging hummingbirds might be a useful, non-lethal sampling method for evaluating trace element exposure and provides a sampling alternative since their small body size limits traditional sampling of blood and tissues. The

Trace Elements in Marine Sediment and Organisms in the Gulf of Thailand

Science.gov (United States)

Worakhunpiset, Suwalee

2018-01-01

This review summarizes the findings from studies of trace element levels in marine sediment and organisms in the Gulf of Thailand. Spatial and temporal variations in trace element concentrations were observed. Although trace element contamination levels were low, the increased urbanization and agricultural and industrial activities may adversely affect ecosystems and human health. The periodic monitoring of marine environments is recommended in order to minimize human health risks from the consumption of contaminated marine organisms. PMID:29677146

Efficiency and Privacy Enhancement for a Track and Trace System of RFID-Based Supply Chains

Directory of Open Access Journals (Sweden)

Xunjun Chen

2015-06-01

Full Text Available One of the major applications of Radio Frequency Identification (RFID technology is in supply chain management as it promises to provide real-time visibility based on the function of track and trace. However, such an RFID-based track and trace system raises new security and privacy challenges due to the restricted resource of tags. In this paper, we refine three privacy related models (i.e., the privacy, path unlinkability, and tag unlinkability of RFID-based track and trace systems, and clarify the relations among these privacy models. Specifically, we have proven that privacy is equivalent to path unlinkability and tag unlinkability implies privacy. Our results simplify the privacy concept and protocol design for RFID-based track and trace systems. Furthermore, we propose an efficient track and trace scheme, Tracker+, which allows for authentic and private identification of RFID-tagged objects in supply chains. In the Tracker+, no computational ability is required for tags, but only a few bytes of storage (such as EPC Class 1 Gen 2 tags are needed to store the tag state. Indeed, Tracker+ reduces the memory requirements for each tag by one group element compared to the Tracker presented in other literature. Moreover, Tracker+ provides privacy against supply chain inside attacks.

Alterations of serum antioxidant trace elements (Se, Zn and Cu status in patients with cutaneous leishmaniasis

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Leila Farzin

2014-02-01

Full Text Available Objective: To assess the serum antioxidant trace elements selenium (Se, zinc (Zn and copper (Cu in cutaneous leishmaniasis patients. Methods: In this study, serum Se, Zn and Cu was determined by using atomic absorption spectrometry in patients with cutaneous leishmaniasis (n=95. The values were statistically compared between patients and control group (n=100 using One-way analysis of variance (ANOVA. Results: Our results showed that there was a significant difference in the values of Se and Zn between two groups (P0.05. Se and Zn levels were found to be (4.33依1.06 and (70.23依19.12 µg/dL in cutaneous leishmaniasis cases, and these values were found statistically lower compared to the controls (11.10依2.37 and (119.61依26.18 µg/dL, respectively. Conclusions: The observations that host products are released from stimulated leukocytes and could induce metabolic changes similar to an acute-phase response revealed an endocrine role for the immune system. Characteristic changes in trace-mineral metabolism are an integral part of the acute-phase response. The changes are usually reflected in decreased serum Se and Zn concentrations.

Tracing Improving Livelihoods in Rural Africa Using Local Measures of Wealth: A Case Study from Central Tanzania, 1991–2016

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Wilhelm Östberg

2018-04-01

Full Text Available We studied livelihood changes and poverty dynamics over a 25-year period in two villages in central Tanzania. The villages were, from the early 1990s and 2000s, strikingly poor with between 50% and 55% of families in the poorest wealth groups. 25 years later much has changed: people have become substantially wealthier, with 64% and 71% in the middle wealth groups. The new wealth had been generated locally, from farming, particularly of sunflowers as a cash crop. This goes against a conventional view of small-scale farming in Tanzania as being stagnant or unproductive. The area of land farmed per family has increased, almost doubling in one village. People have made money, which they invest in mechanised farming, improved housing, education of their children, livestock, and consumer goods. Improved infrastructure and local entrepreneurs have played key roles in the area’s transformation. Locally identified wealth rankings showed that most villagers, those in the middle wealth groups and above, can now support themselves from their land, which is a notable change to a time when 71% and 82% in each village respectively depended on casual labour for their survival. This change has come at a cost to the environment. By 2016, the village forests have largely gone and been replaced by farms. Farmers were concerned that the climate was turning drier because of deforestation. Studying the mundane—the material used in roofs, the size of farms, and so on made it possible to trace and understand the radical transition the area has experienced.

Tracing a Route and Finding a Shortcut: The Working Memory, Motivational, and Personality Factors Involved

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Francesca Pazzaglia

2018-05-01

Full Text Available Wayfinding (WF is the ability to move around efficiently and find the way from a starting point to a destination. It is a component of spatial navigation, a coordinate and goal-directed movement of one’s self through the environment. In the present study, the relationship between WF tasks (route tracing and shortcut finding and individual factors were explored with the hypothesis that WF tasks would be predicted by different types of cognitive, affective, motivational variables, and personality factors. A group of 116 university students (88 F. were conducted along a route in a virtual environment and then asked first to trace the same route again, and then to find a shortcut between the start and end points. Several instruments assessing visuospatial working memory, mental rotation ability, self-efficacy, spatial anxiety, positive attitude to exploring, and personality traits were administered. The results showed that a latent spatial ability factor (measured with the visuospatial working memory and mental rotations tests – controlled for gender – predicted route-tracing performance, while self-report measures of anxiety, efficacy, and pleasure in exploring, and some personality traits were more likely to predict shortcut-finding performance. We concluded that both personality and cognitive abilities affect WF performance, but differently, depending on the requirements of the task.

Statistics for products of traces of high powers of the frobenius class of hyperelliptic curves

OpenAIRE

Roditty-Gershon, Edva

2011-01-01

We study the averages of products of traces of high powers of the Frobenius class of hyperelliptic curves of genus g over a fixed finite field. We show that for increasing genus g, the limiting expectation of these products equals to the expectation when the curve varies over the unitary symplectic group USp(2g). We also consider the scaling limit of linear statistics for eigenphases of the Frobenius class of hyperelliptic curves, and show that their first few moments are Gaussian.

Improved PIXE analysis of micro- and trace elements in dental composites

International Nuclear Information System (INIS)

Preoteasa, E. A.; Ciortea, C.; Fluerasu, D.; Enescu, S. E.; Preoteasa, E.

2001-01-01

Due to the interactions occurring at the solid-solid and solid-liquid interfaces of a tooth's filling, the mineral elements of the restorative composite may induce a complex response of the organism. To study such problems, sensitive surface trace element analysis is required. Particle-induced X-ray emission (PIXE) has a detection limit one order of magnitude lower than XRF and has been used for hard dental tissues, but not yet for dental composites. We evaluated the potential of PIXE in a study of ten types of composites used in restorative dentistry, some of them with two color shades each. The samples were prepared as described for XRF. The measurements were performed with 3 MeV protons from a van de Graaff tandem linear accelerator, using a hyper pure Ge detector and collecting the spectra for 1.5-4 hours. The spectra were processed with the program Leone. The proton route in the sample calculated with the Trim program (∼ 50-100 μm) exceeded the size of mineral particles (0.02-30 μm), thus granularity did not affect the analysis. The PIXE analysis detected Z ≥ 19 elements in all composites, and Z≥14 elements in only one low Z material. PIXE detected generally the same dominant elements, but many more trace elements than XRF. Thus both Charisma (Kulzer) and Pekafill (Bayer) contained Ba as the major element, but trace elements were Ni, Zn, In, in the first, and Fe, Cu, Zn, Sr, Ag in the second. In other glass- and ceramics-based materials we found: Ca, Zr, Ba, Yb and traces of Sr, In, and possibly Ti in Tetric Ceram and in Ariston (both from Vivadent); Ca, Zr, Ba, Hf, possibly Mn, and traces of Ni, Ho, Ti, Fe, Cr in Valux Plus (3M Dental); Sr, Ba (major), K, Fe, Mn (minor), and traces of Ni, Zn, In, in F2000 Compomer (3M Dental); Ba (major) and traces of Fe, Ni, Sr in Surefil (Dentsply). In quartz-based materials we detected: Si, Ca, Ti, Fe and traces of K, Cl, Cr, Ni, Cu, Zn in Evicrol (Spofa); low and trace levels of Ca, Ti, Cr, Mn, Fe, Cu in

Tracing the Origins of IgE, Mast Cells, and Allergies by Studies of Wild Animals

OpenAIRE

Hellman, Lars T.; Akula, Srinivas; Thorpe, Michael; Fu, Zhirong

2017-01-01

In most industrialized countries, allergies have increased in frequency quite dramatically during the past 50 years. Estimates show that 20–30% of the populations are affected. Allergies have thereby become one of the major medical challenges of the twenty-first century. Despite several theories including the hygiene hypothesis, there are still very few solid clues concerning the causes of this increase. To trace the origins of allergies, we have studied cells and molecules of importance for ...

Determination of trace elements: Neutron-activation analysis in geochemistry and cosmochemistry

International Nuclear Information System (INIS)

Kolesov, G.M.

1994-01-01

Geochemistry, like cosmochemistry, open-quotes studies chemical elements hor-ellipsis of the crust and hor-ellipsis the Earth hor-ellipsis their history, their distribution hor-ellipsis their genetic hor-ellipsis connectionsclose quotes and is based on data on the abundance and distribution of elements obtained by various analytical methods. Neutron-activation analysis (NAA) plays a particular role in this respect. This is due to its high sensitivity (detection limit as small as 10 -14 g), which makes possible the use of samples of arbitrary mass, and also due to the possibility of obtaining information about composition without destruction of the object, conserving, if required, the unique material under investigation. Of the most interest are the data on the contents for a number of trace elements (at a level of 10 -7 - 10 -4 %), among which are rare-earth elements (REE), U, Th, Zr, Hf, Ta, W, Ga, Ni, Rb, Cs, platinum-group metals, Ag, Au, etc. These elements are considered as indicators of geochemical processes associated with the genesis and evolution of solar system bodies in early and more recent stages of evolution; they are also used to study processes and phenomena at zone boundaries: river-sea, ocean-atmosphere, and so on. The aim of this work is to show the capabilities of NAA in the determination of trace elements

Trace element analysis: a diagnostic tool

International Nuclear Information System (INIS)

Qureshi, I.H.; Cheema, M.N.

1976-09-01

The human mody continuously assimilates a variety of elements from the environment, and the concentration of these elements in the blood is regulated by means of various homeostatic mechanisms. Some of the elements, though present in very small amounts, have highly specialized functions in initiating many biochemical reactions. These elements, known as essential trace elements, are closely related to human diseases since their deficiency or excess induces physiological changes. Many diseases such as hypertension, atherosclerosis, diabetes, etc., are related to an imbalance in trace element. The measurement of trace elements in body fluids and tissues can, therefore, be effectively employed for diagnostic tests

Remediation using trace element humate surfactant

Energy Technology Data Exchange (ETDEWEB)

Riddle, Catherine Lynn; Taylor, Steven Cheney; Bruhn, Debra Fox

2016-08-30

A method of remediation at a remediation site having one or more undesirable conditions in which one or more soil characteristics, preferably soil pH and/or elemental concentrations, are measured at a remediation site. A trace element humate surfactant composition is prepared comprising a humate solution, element solution and at least one surfactant. The prepared trace element humate surfactant composition is then dispensed onto the remediation site whereby the trace element humate surfactant composition will reduce the amount of undesirable compounds by promoting growth of native species activity. By promoting native species activity, remediation occurs quickly and environmental impact is minimal.

Tracing the breeding farm of domesticated pig using feature selection (

Directory of Open Access Journals (Sweden)

Taehyung Kwon

2017-11-01

Full Text Available Objective Increasing food safety demands in the animal product market have created a need for a system to trace the food distribution process, from the manufacturer to the retailer, and genetic traceability is an effective method to trace the origin of animal products. In this study, we successfully achieved the farm tracing of 6,018 multi-breed pigs, using single nucleotide polymorphism (SNP markers strictly selected through least absolute shrinkage and selection operator (LASSO feature selection. Methods We performed farm tracing of domesticated pig (Sus scrofa from SNP markers and selected the most relevant features for accurate prediction. Considering multi-breed composition of our data, we performed feature selection using LASSO penalization on 4,002 SNPs that are shared between breeds, which also includes 179 SNPs with small between-breed difference. The 100 highest-scored features were extracted from iterative simulations and then evaluated using machine-leaning based classifiers. Results We selected 1,341 SNPs from over 45,000 SNPs through iterative LASSO feature selection, to minimize between-breed differences. We subsequently selected 100 highest-scored SNPs from iterative scoring, and observed high statistical measures in classification of breeding farms by cross-validation only using these SNPs. Conclusion The study represents a successful application of LASSO feature selection on multi-breed pig SNP data to trace the farm information, which provides a valuable method and possibility for further researches on genetic traceability.

Multidimensional study of the trace elements in the American south western prophyry copper type deposits: mineralogy of uranium

International Nuclear Information System (INIS)

Cesbron, Fabien; Drin, Nicolas.

1981-09-01

The use of the spark source masse spectrometry and data treatment methods (principal component analysis and discriminent analysis) allow to describe the trace elements comportments in the porphyry copper type deposits of Arizona (USA) and Sonora (Mexico). The chemical elements are studied in relationship with the alteration zones of these deposits. A electronic microprobe study specifies the uranium bearing minerals [fr

Linking genes to ecosystem trace gas fluxes in a large-scale model system

Science.gov (United States)

Meredith, L. K.; Cueva, A.; Volkmann, T. H. M.; Sengupta, A.; Troch, P. A.

2017-12-01

Soil microorganisms mediate biogeochemical cycles through biosphere-atmosphere gas exchange with significant impact on atmospheric trace gas composition. Improving process-based understanding of these microbial populations and linking their genomic potential to the ecosystem-scale is a challenge, particularly in soil systems, which are heterogeneous in biodiversity, chemistry, and structure. In oligotrophic systems, such as the Landscape Evolution Observatory (LEO) at Biosphere 2, atmospheric trace gas scavenging may supply critical metabolic needs to microbial communities, thereby promoting tight linkages between microbial genomics and trace gas utilization. This large-scale model system of three initially homogenous and highly instrumented hillslopes facilitates high temporal resolution characterization of subsurface trace gas fluxes at hundreds of sampling points, making LEO an ideal location to study microbe-mediated trace gas fluxes from the gene to ecosystem scales. Specifically, we focus on the metabolism of ubiquitous atmospheric reduced trace gases hydrogen (H2), carbon monoxide (CO), and methane (CH4), which may have wide-reaching impacts on microbial community establishment, survival, and function. Additionally, microbial activity on LEO may facilitate weathering of the basalt matrix, which can be studied with trace gas measurements of carbonyl sulfide (COS/OCS) and carbon dioxide (O-isotopes in CO2), and presents an additional opportunity for gene to ecosystem study. This work will present initial measurements of this suite of trace gases to characterize soil microbial metabolic activity, as well as links between spatial and temporal variability of microbe-mediated trace gas fluxes in LEO and their relation to genomic-based characterization of microbial community structure (phylogenetic amplicons) and genetic potential (metagenomics). Results from the LEO model system will help build understanding of the importance of atmospheric inputs to

Real time ray tracing based on shader

Science.gov (United States)

Gui, JiangHeng; Li, Min

2017-07-01

Ray tracing is a rendering algorithm for generating an image through tracing lights into an image plane, it can simulate complicate optical phenomenon like refraction, depth of field and motion blur. Compared with rasterization, ray tracing can achieve more realistic rendering result, however with greater computational cost, simple scene rendering can consume tons of time. With the GPU's performance improvement and the advent of programmable rendering pipeline, complicated algorithm can also be implemented directly on shader. So, this paper proposes a new method that implement ray tracing directly on fragment shader, mainly include: surface intersection, importance sampling and progressive rendering. With the help of GPU's powerful throughput capability, it can implement real time rendering of simple scene.

Trace Dynamics and a non-commutative special relativity

International Nuclear Information System (INIS)

Lochan, Kinjalk; Singh, T.P.

2011-01-01

Trace Dynamics is a classical dynamical theory of non-commuting matrices in which cyclic permutation inside a trace is used to define the derivative with respect to an operator. We use the methods of Trace Dynamics to construct a non-commutative special relativity. We define a line-element using the Trace over space-time coordinates which are assumed to be operators. The line-element is shown to be invariant under standard Lorentz transformations, and is used to construct a non-commutative relativistic dynamics. The eventual motivation for constructing such a non-commutative relativity is to relate the statistical thermodynamics of this classical theory to quantum mechanics. -- Highlights: → Classical time is external to quantum mechanics. → This implies need for a formulation of quantum theory without classical time. → A starting point could be a non-commutative special relativity. → Such a relativity is developed here using the theory of Trace Dynamics. → A line-element is defined using the Trace over non-commuting space-time operators.

Active learning of neuron morphology for accurate automated tracing of neurites

Science.gov (United States)

Gala, Rohan; Chapeton, Julio; Jitesh, Jayant; Bhavsar, Chintan; Stepanyants, Armen

2014-01-01

Automating the process of neurite tracing from light microscopy stacks of images is essential for large-scale or high-throughput quantitative studies of neural circuits. While the general layout of labeled neurites can be captured by many automated tracing algorithms, it is often not possible to differentiate reliably between the processes belonging to different cells. The reason is that some neurites in the stack may appear broken due to imperfect labeling, while others may appear fused due to the limited resolution of optical microscopy. Trained neuroanatomists routinely resolve such topological ambiguities during manual tracing tasks by combining information about distances between branches, branch orientations, intensities, calibers, tortuosities, colors, as well as the presence of spines or boutons. Likewise, to evaluate different topological scenarios automatically, we developed a machine learning approach that combines many of the above mentioned features. A specifically designed confidence measure was used to actively train the algorithm during user-assisted tracing procedure. Active learning significantly reduces the training time and makes it possible to obtain less than 1% generalization error rates by providing few training examples. To evaluate the overall performance of the algorithm a number of image stacks were reconstructed automatically, as well as manually by several trained users, making it possible to compare the automated traces to the baseline inter-user variability. Several geometrical and topological features of the traces were selected for the comparisons. These features include the total trace length, the total numbers of branch and terminal points, the affinity of corresponding traces, and the distances between corresponding branch and terminal points. Our results show that when the density of labeled neurites is sufficiently low, automated traces are not significantly different from manual reconstructions obtained by trained users. PMID

Active learning of neuron morphology for accurate automated tracing of neurites

Directory of Open Access Journals (Sweden)

Rohan eGala

2014-05-01

Full Text Available Automating the process of neurite tracing from light microscopy stacks of images is essential for large-scale or high-throughput quantitative studies of neural circuits. While the general layout of labeled neurites can be captured by many automated tracing algorithms, it is often not possible to differentiate reliably between the processes belonging to different cells. The reason is that some neurites in the stack may appear broken due to imperfect labeling, while others may appear fused due to the limited resolution of optical microscopy. Trained neuroanatomists routinely resolve such topological ambiguities during manual tracing tasks by combining information about distances between branches, branch orientations, intensities, calibers, tortuosities, colors, as well as the presence of spines or boutons. Likewise, to evaluate different topological scenarios automatically, we developed a machine learning approach that combines many of the above mentioned features. A specifically designed confidence measure was used to actively train the algorithm during user-assisted tracing procedure. Active learning significantly reduces the training time and makes it possible to obtain less than 1% generalization error rates by providing few training examples. To evaluate the overall performance of the algorithm a number of image stacks were reconstructed automatically, as well as manually by several trained users, making it possible to compare the automated traces to the baseline inter-user variability. Several geometrical and topological features of the traces were selected for the comparisons. These features include the total trace length, the total numbers of branch and terminal points, the affinity of corresponding traces, and the distances between corresponding branch and terminal points. Our results show that when the density of labeled neurites is sufficiently low, automated traces are not significantly different from manual reconstructions obtained by

A new method for automatic discontinuity traces sampling on rock mass 3D model

Science.gov (United States)

Umili, G.; Ferrero, A.; Einstein, H. H.

2013-02-01

A new automatic method for discontinuity traces mapping and sampling on a rock mass digital model is described in this work. The implemented procedure allows one to automatically identify discontinuity traces on a Digital Surface Model: traces are detected directly as surface breaklines, by means of maximum and minimum principal curvature values of the vertices that constitute the model surface. Color influence and user errors, that usually characterize the trace mapping on images, are eliminated. Also trace sampling procedures based on circular windows and circular scanlines have been implemented: they are used to infer trace data and to calculate values of mean trace length, expected discontinuity diameter and intensity of rock discontinuities. The method is tested on a case study: results obtained applying the automatic procedure on the DSM of a rock face are compared to those obtained performing a manual sampling on the orthophotograph of the same rock face.

Software for computerised analysis of cardiotocographic traces.