WorldWideScience

Sample records for greater lead time

  1. Why shorter half-times of repair lead to greater damage in pulsed brachytherapy

    International Nuclear Information System (INIS)

    Fowler, J.F.

    1993-01-01

    Pulsed brachytherapy consists of replacing continuous irradiation at low dose-rate with a series of medium dose-rate fractions in the same overall time and to the same total dose. For example, pulses of 1 Gy given every 2 hr or 2 Gy given every 4 hr would deliver the same 70 Gy in 140 hr as continuous irradiation at 0.5 Gy/hr. If higher dose-rates are used, even with gaps between the pulses, the biological effects are always greater. Provided that dose rates in the pulse do not exceed 3 Gy/hr, and provided that pulses are given as often as every 2 hr, the inevitable increases of biological effect are no larger than a few percent (of biologically effective dose or extrapolated response dose). However, these increases are more likely to exceed 10% (and thus become clinically significant) if the half-time of repair of sublethal damage is short (less than 1 hr) rather than long. This somewhat unexpected finding is explained in detail here. The rise and fall of Biologically Effective Dose (and hence of Relative Effectiveness, for a constant dose in each pulse) is calculated during and after single pulses, assuming a range of values of T 1/2 , the half-time of sublethal damage repair. The area under each curve is proportional to Biologically Effective Dose and therefore to log cell kill. Pulses at 3 Gy/hr do yield greater biological effect (dose x integrated Relative Effectiveness) than lower dose-rate pulses or continuous irradiation at 0.5 Gy/hr. The contrast is greater for the short T 1/2 of 0.5 hr than for the longer T 1/2 of 1.5 hr. More biological damage will be done (compared with traditional low dose rate brachytherapy) in tissues with short T 1/2 (0.1-1 hr) than in tissues with longer T 1/2 values. 8 refs., 3 figs

  2. Evil genius? How dishonesty can lead to greater creativity.

    Science.gov (United States)

    Gino, Francesca; Wiltermuth, Scott S

    2014-04-01

    We propose that dishonest and creative behavior have something in common: They both involve breaking rules. Because of this shared feature, creativity may lead to dishonesty (as shown in prior work), and dishonesty may lead to creativity (the hypothesis we tested in this research). In five experiments, participants had the opportunity to behave dishonestly by overreporting their performance on various tasks. They then completed one or more tasks designed to measure creativity. Those who cheated were subsequently more creative than noncheaters, even when we accounted for individual differences in their creative ability (Experiment 1). Using random assignment, we confirmed that acting dishonestly leads to greater creativity in subsequent tasks (Experiments 2 and 3). The link between dishonesty and creativity is explained by a heightened feeling of being unconstrained by rules, as indicated by both mediation (Experiment 4) and moderation (Experiment 5).

  3. Coping Skills Help Explain How Future-Oriented Adolescents Accrue Greater Well-Being Over Time.

    Science.gov (United States)

    Chua, Li Wen; Milfont, Taciano L; Jose, Paul E

    2015-11-01

    Adolescents who endorse greater levels of future orientation report greater well-being over time, but we do not know the mechanism by which this happens. The present longitudinal study examined whether both adaptive as well as maladaptive coping strategies might explain how future orientation leads to ill-being and well-being over time in young New Zealanders. A sample of 1,774 preadolescents and early adolescents (51.9 % female) aged 10-15 years at Time 1 completed a self-report survey three times with 1 year intervals in between. Longitudinal mediation path models were constructed to determine whether and how maladaptive and adaptive coping strategies at Time 2 functioned as mediators between future orientation at Time 1 and ill-being and well-being at Time 3. Results showed that future orientation predicted lower maladaptive coping, which in turn predicted lower substance use and self-harming behavior. All three well-being outcomes (i.e., happiness with weight, vitality, and sleep) were consistently predicted by future orientation, and all three pathways were mediated by both lower maladaptive and higher adaptive coping strategies (with the exception of happiness with weight, which was mediated only by lower maladaptive coping). The results suggest that several pathways by which future orientation leads to greater well-being occurs through an increased use of adaptive coping, a decreased use of maladaptive coping, or both.

  4. Practicing more retrieval routes leads to greater memory retention.

    Science.gov (United States)

    Zheng, Jun; Zhang, Wei; Li, Tongtong; Liu, Zhaomin; Luo, Liang

    2016-09-01

    A wealth of research has shown that retrieval practice plays a significant role in improving memory retention. The current study focused on one simple yet rarely examined question: would repeated retrieval using two different retrieval routes or using the same retrieval route twice lead to greater long-term memory retention? Participants elaborately learned 22 Japanese-Chinese translation word pairs using two different mediators. Half an hour after the initial study phase, the participants completed two retrieval sessions using either one mediator (Tm1Tm1) or two different mediators (Tm1Tm2). On the final test, which was performed 1week after the retrieval practice phase, the participants received only the cue with a request to report the mediator (M1 or M2) followed by the target (Experiment 1) or only the mediator (M1 or M2) with a request to report the target (Experiment 2). The results of Experiment 1 indicated that the participants who practiced under the Tm1Tm2 condition exhibited greater target retention than those who practiced under the Tm1Tm1 condition. This difference in performance was due to the significant disadvantage in mediator retrieval and decoding of the unpracticed mediator under the Tm1Tm1 condition. Although mediators were provided to participants on the final test in Experiment 2, decoding of the unpracticed mediators remained less effective than decoding of the practiced mediators. We conclude that practicing multiple retrieval routes leads to greater memory retention than focusing on a single retrieval route. Thus, increasing retrieval variability during repeated retrieval practice indeed significantly improves long-term retention in a delay test. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Development and validation of a lead emission inventory for the Greater Cairo area

    Directory of Open Access Journals (Sweden)

    Zeinab Safar

    2014-09-01

    Full Text Available Studies that investigate the environmental health risks to Cairo residents invariably conclude that lead is one of the area’s major health hazards. The Cairo Air Improvement Project (CAIP, which was implemented by a team led by Chemonics International, funded by USAID in partnership with the Egyptian Environmental Affairs Agency (EEAA, started developing a lead emission inventory for the greater Cairo (GC area in 1998. The inventory contains a list by major source of the annual lead emissions in the GC area. Uses of the inventory and associated database include developing effective regulatory and control strategies, assessing emissions trends, and conducting modeling exercises. This paper describes the development of the current lead emissions inventory (1999–2010, along with an approach to develop site specific emission factors and measurements to validate the inventory. This paper discusses the major sources of lead in the GC area, which include lead smelters, Mazout (heavy fuel oil combustion, lead manufacturing batteries factories, copper foundries, and cement factories. Included will be the trend in the lead emissions inventory with regard to the production capacity of each source category. In addition, the lead ambient measurements from 1999 through 2010 are described and compared with the results of Source Attribution Studies (SAS conducted in 1999, 2002, and 2010. Due to EEAA/CAIP efforts, a remarkable decrease in more than 90% in lead emissions was attained for 2007.

  6. Load Dependent Lead Times and Sustainability

    DEFF Research Database (Denmark)

    Pahl, Julia; Voss, Stefan

    2016-01-01

    to prevent decreased quality or waste of production parts and products. This gains importance because waiting times imply longer lead times charging the production system with work in process inventories. Longer lead times can lead to quality losses due to depreciation, so that parts need to be reworked...... if possible or discarded. But return flows of products for rework or remanufacturing actions significantly complicate the production planning process. We analyze sustainability options with respect to lead time management by formulating a comprehensive mathematical model. We consider a deterministic, mixed...

  7. Production Planning with Load Dependent Lead Times

    DEFF Research Database (Denmark)

    Pahl, Julia

    2005-01-01

    Lead times impact the performance of the supply chain significantly. Although there is a large literature concerning queuing models for the analysis of the relationship between capacity utilization and lead times, and there is a substantial literature concerning control and order release policies...... that take lead times into consideration, there have been only few papers describing models at the aggregate planning level that recognize the relationship between the planned utilization of capacity and lead times. In this paper we provide an in-depth discussion of the state-of-the art in this literature......, with particular attention to those models that are appropriate at the aggregate planning level....

  8. Modeling stochastic lead times in multi-echelon systems

    NARCIS (Netherlands)

    Diks, E.B.; Heijden, van der M.C.

    1996-01-01

    In many multi-echelon inventory systems the lead times are random variables. A common and reasonable assumption in most models is that replenishment orders do not cross, which implies that successive lead times are correlated. However, the process which generates such lead times is usually not

  9. Modeling stochastic lead times in multi-echelon systems

    NARCIS (Netherlands)

    Diks, E.B.; van der Heijden, M.C.

    1997-01-01

    In many multi-echelon inventory systems, the lead times are random variables. A common and reasonable assumption in most models is that replenishment orders do not cross, which implies that successive lead times are correlated. However, the process that generates such lead times is usually not well

  10. Administrative Lead Time at Navy Inventory Control Points

    National Research Council Canada - National Science Library

    Granetto, Paul

    1994-01-01

    .... We also evaluated the internal controls established for administrative lead time and the adequacy of management's implementation of the DoD Internal Management Control Program for monitoring administrative lead time...

  11. Moderate Versus Light Pressure Massage Therapy Leads to Greater Weight Gain in Preterm Infants

    Science.gov (United States)

    Field, Tiffany; Diego, Miguel A.; Hernandez-Reif, Maria; Deeds, Osvelia; Figuereido, Barbara

    2007-01-01

    Sixty-eight preterm infants (M GA=3Owks.) were randomly assigned to a moderate or to a light pressure massage therapy group to receive 15 massages 3 times per day for 5 days. Behavior state, stress behaviors and heart rate were recorded for 15 minutes before and during the first 15-minute therapy session. Weight gain was recorded over the 5 day therapy period. The moderate versus light pressure massage group gained significantly more weight per day. During the behavior observations the moderate versus light pressure massage group showed significantly lower increases from the pre-session to the session recording on: 1) active sleep; 2) fussing; 3) crying; 4) movement; and 5) stress behavior (hiccupping). They also showed a smaller decrease in deep sleep, a greater decrease in heart rate and a greater increase in vagal tone. Thus, the moderate pressure massage therapy group appeared to be more relaxed and less aroused than the light pressure massage group which may have contributed to the greater weight gain of the moderate pressure massage therapy group. PMID:17138310

  12. Abstract "why" Thoughts About Success Lead to Greater Positive Generalization in Sport Participants.

    Science.gov (United States)

    Van Lier, Jens; Moulds, Michelle L; Raes, Filip

    2015-01-01

    Generalizing from a single failure or success to future performances and their self-concept could have an important impact on sport participants. This study examined the impact of the way sport participants think about success on positive generalization. Sport participants (N = 222) completed an online experimental study in which they were induced to think about meanings, causes and implications (i.e., abstract-"why"-thinking) or about more perceptual concrete aspects of their performance (i.e., concrete-"how"-thinking). We hypothesized that abstract-"why"-thinking would lead to greater positive generalization and that this effect would be moderated by self-esteem. Our results supported our hypothesis that abstract thinking increased positive generalization, and this effect was more clearly visible in sport participants with higher self-esteem. These results suggest that retrospective thinking about the "why" of a good performance may benefit athletes in the long run because they generalize the outcome to future performances and their self-concept which may boost their motivation and consequently their performance.

  13. REDUCING LEAD TIME USING FUZZY LOGIC AT JOB SHOP

    Directory of Open Access Journals (Sweden)

    EMİN GÜNDOĞAR

    2000-06-01

    Full Text Available One problem encountering at the job shop scheduling is minimum production size of machine is different from each another. This case increases lead time. A new approach was improved to reduce lead time. In this new approach, the parts, which materials are in stock and orders coming very frequently are assigned to machine to reduce lead time. Due the fact that there are a lot of machine and orders, it is possible to become so1ne probletns. In this paper, fuzzy logic is used to cope with this problem. New approach was simulated at the job sop that has owner 15 machinery and 50 orders. Simulation results showed that new approach reduced lead time between 27.89% and 32.36o/o

  14. Periodic capacity management under a lead-time performance constraint

    NARCIS (Netherlands)

    Büyükkaramikli, N.C.; Bertrand, J.W.M.; Ooijen, van H.P.G.

    2013-01-01

    In this paper, we study a production system that operates under a lead-time performance constraint which guarantees the completion of an order before a pre-determined lead-time with a certain probability. The demand arrival times and the service requirements for the orders are random. To reduce the

  15. Resistance patterns among multidrug-resistant tuberculosis patients in greater metropolitan Mumbai: trends over time.

    Science.gov (United States)

    Dalal, Alpa; Pawaskar, Akshay; Das, Mrinalini; Desai, Ranjan; Prabhudesai, Pralhad; Chhajed, Prashant; Rajan, Sujeet; Reddy, Deepesh; Babu, Sajit; Jayalakshmi, T K; Saranchuk, Peter; Rodrigues, Camilla; Isaakidis, Petros

    2015-01-01

    While the high burden of multidrug-resistant tuberculosis (MDR-TB) itself is a matter of great concern, the emergence and rise of advanced forms of drug-resistance such as extensively drug-resistant TB (XDR-TB) and extremely drug-resistant TB (XXDR-TB) is more troubling. The aim of this study was to investigate the trends over time of patterns of drug resistance in a sample of MDR-TB patients in greater metropolitan Mumbai, India. This was a retrospective, observational study of drug susceptibility testing (DST) results among MDR-TB patients from eight health care facilities in greater Mumbai between 2005 and 2013. We classified resistance patterns into four categories: MDR-TB, pre-XDR-TB, XDR-TB and XXDR-TB. A total of 340 MDR-TB patients were included in the study. Pre-XDR-TB was the most common form of drug-resistant TB observed overall in this Mumbai population at 56.8% compared to 29.4% for MDR-TB. The proportion of patients with MDR-TB was 39.4% in the period 2005-2007 and 27.8% in 2011-2013, while the proportion of those with XDR-TB and XXDR-TB was changed from 6.1% and 0% respectively to 10.6% and 5.6% during the same time period. During the same periods, the proportions of patients with ofloxacin, moxifloxacin and ethionamide resistance significantly increased from 57.6% to 75.3%, from 60.0% to 69.5% and from 24.2% to 52.5% respectively (pMumbai highlight the need for individualized drug regimens, designed on the basis of DST results involving first- and second-line anti-TB drugs and treatment history of the patient. A drug-resistant TB case-finding strategy based on molecular techniques that identify only rifampicin resistance will lead to initiation of suboptimal treatment regimens for a significant number of patients, which may in turn contribute to amplification of resistance and transmission of strains with increasingly advanced resistance within the community.

  16. Abstract ‘why’ thoughts about success lead to greater positive generalization in sport participants

    Directory of Open Access Journals (Sweden)

    Jens eVan Lier

    2015-11-01

    Full Text Available Generalizing from a single failure or success to future performances and their self-concept could have an important impact on sport participants. This study examined the impact of the way sport participants think about success on positive generalization. Sport participants (N=222 completed an online experimental study in which they were induced to think about meanings, causes and implications (i.e., abstract-‘why’-thinking or about more perceptual concrete aspects of their performance (i.e., concrete-‘how’-thinking. We hypothesized that abstract-‘why’-thinking would lead to greater positive generalization and that this effect would be moderated by self-esteem. Our results supported our hypothesis that abstract thinking increased positive generalization, and this effect was more clearly visible in sport participants with higher self-esteem. These results suggest that retrospective thinking about the ‘why’ of a good performance may benefit athletes in the long run because they generalize the outcome to future performances and their self-concept which may boost their motivation and consequently their performance.

  17. Lead-Time Models Should Not Be Used to Estimate Overdiagnosis in Cancer Screening

    DEFF Research Database (Denmark)

    Zahl, Per-Henrik; Jørgensen, Karsten Juhl; Gøtzsche, Peter C

    2014-01-01

    screening--the excess-incidence approach and the lead-time approach--that rely on two different lead-time definitions. Overdiagnosis when screening with mammography has varied from 0 to 75 %. We have explained that these differences are mainly caused by using different definitions and methods......Lead-time can mean two different things: Clinical lead-time is the lead-time for clinically relevant tumors; that is, those that are not overdiagnosed. Model-based lead-time is a theoretical construct where the time when the tumor would have caused symptoms is not limited by the person's death....... It is the average time at which the diagnosis is brought forward for both clinically relevant and overdiagnosed cancers. When screening for breast cancer, clinical lead-time is about 1 year, while model-based lead-time varies from 2 to 7 years. There are two different methods to calculate overdiagnosis in cancer...

  18. PROCESS INNOVATION: HOLISTIC SCENARIOS TO REDUCE TOTAL LEAD TIME

    Directory of Open Access Journals (Sweden)

    Alin POSTEUCĂ

    2015-11-01

    Full Text Available The globalization of markets requires continuous development of business holistic scenarios to ensure acceptable flexibility to satisfy customers. Continuous improvement of supply chain supposes continuous improvement of materials and products lead time and flow, material stocks and finished products stocks and increasing the number of suppliers close by as possible. The contribution of our study is to present holistic scenarios of total lead time improvement and innovation by implementing supply chain policy.

  19. Exposure to Sexual Stimuli Induces Greater Discounting Leading to Increased Involvement in Cyber Delinquency Among Men.

    Science.gov (United States)

    Cheng, Wen; Chiou, Wen-Bin

    2018-02-01

    People frequently encounter sexual stimuli during Internet use. Research has shown that stimuli inducing sexual motivation can lead to greater impulsivity in men, as manifested in greater temporal discounting (i.e., a tendency to prefer smaller, immediate gains to larger, future ones). Extant findings in crime research suggest that delinquents tend to focus on short-term gains while failing to adequately think through the longer-term consequences of delinquent behavior. We experimentally tested the possibility that exposure to sexual stimuli is associated with the tendency to engage in cyber delinquency among men, as a result of their overly discounting remote consequences. In Experiment 1, participants exposed to pictures of "sexy" women were more likely to discount the future and were more inclined to make cyber-delinquent choices (e.g., cyberbullying, cyber fraud, cyber theft, and illegal downloading), compared with male participants who rated the sex appeal of less sexy opposite-sex pictures. However, these relationships were not observed in female participants exposed to either highly or less sexy pictures of men. In Experiment 2, male participants exposed to sexual primes showed a greater willingness to purchase a wide range of counterfeit rather than authentic products online and experienced a higher likelihood of logging into the other person's Facebook webpage (i.e., invading online privacy). The discounting tendency mediated the link between exposure to sexual primes and the inclination to engage in cyber-delinquent behavior. These findings provide insight into a strategy for reducing men's involvement in cyber delinquency; that is, through less exposure to sexual stimuli and promotion of delayed gratification. The current results suggest that the high availability of sexual stimuli in cyberspace may be more closely associated with men's cyber-delinquent behavior than previously thought.

  20. Maritime Load Dependent Lead Times - An Analysis

    DEFF Research Database (Denmark)

    Pahl, Julia; Voss, Stefan

    2017-01-01

    in production. Inspired by supply chain planning systems, we analyze the current state of (collaborative) planning in the maritime transport chain with focus on containers. Regarding the problem of congestion, we particularly emphasize on load dependent lead times (LDLT) which are well studied in production....

  1. Integrated vendor-buyer inventory models with inflation and time value of money in controllable lead time

    Directory of Open Access Journals (Sweden)

    Prashant Jindal

    2016-01-01

    Full Text Available In the global critical economic scenario, inflation plays a vital role in deciding optimal pricing of goods in any business entity. This article presents two single-vendor single-buyer integrated supply chain inventory models with inflation and time value of money. Shortage is allowed during the lead-time and it is partially backlogged. Lead time is controllable and can be reduced using crashing cost. In the first model, we consider the demand of lead time follows a normal distribution, and in the second model, it is considered distribution-free. For both cases, our objective is to minimize the integrated system cost by simultaneously optimizing the order quantity, safety factor, lead time and number of lots. The discounted cash flow and classical optimization technique are used to derive the optimal solution for both cases. Numerical examples including the sensitivity analysis of system parameters is provided to validate the results of the supply chain models.

  2. Greater happiness for a greater number: Is that possible in Austria?

    NARCIS (Netherlands)

    R. Veenhoven (Ruut)

    2011-01-01

    textabstractWhat is the final goal of public policy? Jeremy Bentham (1789) would say: greater happiness for a greater number. He thought of happiness as subjective enjoyment of life; in his words as “the sum of pleasures and pains”. In his time the happiness of the great number could not be measured

  3. Greater happiness for a greater number: Is that possible in Germany?

    NARCIS (Netherlands)

    R. Veenhoven (Ruut)

    2009-01-01

    textabstractWhat is the final goal of public policy? Jeremy Bentham (1789) would say: greater happiness for a greater number. He thought of happiness as subjective enjoyment of life; in his words as “the sum of pleasures and pains”. In his time the Happiness of the great number could not be measured

  4. Influence of dispatching rules on average production lead time for multi-stage production systems.

    Science.gov (United States)

    Hübl, Alexander; Jodlbauer, Herbert; Altendorfer, Klaus

    2013-08-01

    In this paper the influence of different dispatching rules on the average production lead time is investigated. Two theorems based on covariance between processing time and production lead time are formulated and proved theoretically. Theorem 1 links the average production lead time to the "processing time weighted production lead time" for the multi-stage production systems analytically. The influence of different dispatching rules on average lead time, which is well known from simulation and empirical studies, can be proved theoretically in Theorem 2 for a single stage production system. A simulation study is conducted to gain more insight into the influence of dispatching rules on average production lead time in a multi-stage production system. We find that the "processing time weighted average production lead time" for a multi-stage production system is not invariant of the applied dispatching rule and can be used as a dispatching rule independent indicator for single-stage production systems.

  5. Critical spare parts ordering decisions using conditional reliability and stochastic lead time

    International Nuclear Information System (INIS)

    Godoy, David R.; Pascual, Rodrigo; Knights, Peter

    2013-01-01

    Asset-intensive companies face great pressure to reduce operation costs and increase utilization. This scenario often leads to over-stress on critical equipment and its spare parts associated, affecting availability, reliability, and system performance. As these resources impact considerably on financial and operational structures, the opportunity is given by demand for decision-making methods for the management of spare parts processes. We proposed an ordering decision-aid technique which uses a measurement of spare performance, based on the stress–strength interference theory; which we have called Condition-Based Service Level (CBSL). We focus on Condition Managed Critical Spares (CMS), namely, spares which are expensive, highly reliable, with higher lead times, and are not available in store. As a mitigation measure, CMS are under condition monitoring. The aim of the paper is orienting the decision time for CMS ordering or just continuing the operation. The paper presents a graphic technique which considers a rule for decision based on both condition-based reliability function and a stochastic/fixed lead time. For the stochastic lead time case, results show that technique is effective to determine the time when the system operation is reliable and can withstand the lead time variability, satisfying a desired service level. Additionally, for the constant lead time case, the technique helps to define insurance spares. In conclusion, presented ordering decision rule is useful to asset managers for enhancing the operational continuity affected by spare parts

  6. Lead Time Study,

    Science.gov (United States)

    1982-05-01

    1979, the number of titanium fabrications dropped from 16 to 4, primarily because of the sponge shortage and EPA and OSHA requirements. Non-military...East - Taiwan, Korea, Singapore, Malaysia and Hong Kong. In addition, a significant amount of ceramic parts, lead frames and high technology

  7. Multilevel Production Systems with Dependent Demand with Uncertainty of Lead Times

    Directory of Open Access Journals (Sweden)

    Haibatolah Sadeghi

    2016-01-01

    Full Text Available This study considers a multilevel assembly system with several components in each sublevel. It is assumed that actual lead time for all components is probabilistic; and periodic order quantity (POQ policy for ordering is utilized. If at a certain level a job is not received at the expected time, a delay is incurred at the delivery of production at this level and this may result in backorders of the finished product. It is assumed in this case that a fixed percentage of the shortage is backlogged and other sales are lost. In the real situation, some but not all customers will wait for backlogged components during a period of shortage, such as for fashionable commodities or high-tech products with the short product life cycle. The objective of this study is to find the planned lead time and periodicity for the total components in order to minimize the expected fixed ordering, holding, and partial backlogging costs for the finished product. In this study, it is assumed that a percentage of components at each level are scrap. A general mathematical model is suggested and the method developed can be used for optimization planned lead time and periodicity for such an MRP system under lead time uncertainties.

  8. Ultrafast time-resolved spectroscopy of lead halide perovskite films

    Science.gov (United States)

    Idowu, Mopelola A.; Yau, Sung H.; Varnavski, Oleg; Goodson, Theodore

    2015-09-01

    Recently, lead halide perovskites which are organic-inorganic hybrid structures, have been discovered to be highly efficient as light absorbers. Herein, we show the investigation of the excited state dynamics and emission properties of non-stoichiometric precursor formed lead halide perovskites grown by interdiffusion method using steady-state and time-resolved spectroscopic measurements. The influence of the different ratios of the non-stoichiometric precursor solution was examined. The observed photoluminescence properties were correlated with the femtosecond transient absorption measurements.

  9. Exposure to dairy manure leads to greater antibiotic resistance and increased mass-specific respiration in soil microbial communities

    Science.gov (United States)

    Avera, Bethany; Badgley, Brian; Barrett, John E.; Franklin, Josh; Knowlton, Katharine F.; Ray, Partha P.; Smitherman, Crystal

    2017-01-01

    Intensifying livestock production to meet the demands of a growing global population coincides with increases in both the administration of veterinary antibiotics and manure inputs to soils. These trends have the potential to increase antibiotic resistance in soil microbial communities. The effect of maintaining increased antibiotic resistance on soil microbial communities and the ecosystem processes they regulate is unknown. We compare soil microbial communities from paired reference and dairy manure-exposed sites across the USA. Given that manure exposure has been shown to elicit increased antibiotic resistance in soil microbial communities, we expect that manure-exposed sites will exhibit (i) compositionally different soil microbial communities, with shifts toward taxa known to exhibit resistance; (ii) greater abundance of antibiotic resistance genes; and (iii) corresponding maintenance of antibiotic resistance would lead to decreased microbial efficiency. We found that bacterial and fungal communities differed between reference and manure-exposed sites. Additionally, the β-lactam resistance gene ampC was 5.2-fold greater under manure exposure, potentially due to the use of cephalosporin antibiotics in dairy herds. Finally, ampC abundance was positively correlated with indicators of microbial stress, and microbial mass-specific respiration, which increased 2.1-fold under manure exposure. These findings demonstrate that the maintenance of antibiotic resistance associated with manure inputs alters soil microbial communities and ecosystem function. PMID:28356447

  10. Exposure to dairy manure leads to greater antibiotic resistance and increased mass-specific respiration in soil microbial communities.

    Science.gov (United States)

    Wepking, Carl; Avera, Bethany; Badgley, Brian; Barrett, John E; Franklin, Josh; Knowlton, Katharine F; Ray, Partha P; Smitherman, Crystal; Strickland, Michael S

    2017-03-29

    Intensifying livestock production to meet the demands of a growing global population coincides with increases in both the administration of veterinary antibiotics and manure inputs to soils. These trends have the potential to increase antibiotic resistance in soil microbial communities. The effect of maintaining increased antibiotic resistance on soil microbial communities and the ecosystem processes they regulate is unknown. We compare soil microbial communities from paired reference and dairy manure-exposed sites across the USA. Given that manure exposure has been shown to elicit increased antibiotic resistance in soil microbial communities, we expect that manure-exposed sites will exhibit (i) compositionally different soil microbial communities, with shifts toward taxa known to exhibit resistance; (ii) greater abundance of antibiotic resistance genes; and (iii) corresponding maintenance of antibiotic resistance would lead to decreased microbial efficiency. We found that bacterial and fungal communities differed between reference and manure-exposed sites. Additionally, the β-lactam resistance gene ampC was 5.2-fold greater under manure exposure, potentially due to the use of cephalosporin antibiotics in dairy herds. Finally, ampC abundance was positively correlated with indicators of microbial stress, and microbial mass-specific respiration, which increased 2.1-fold under manure exposure. These findings demonstrate that the maintenance of antibiotic resistance associated with manure inputs alters soil microbial communities and ecosystem function. © 2017 The Author(s).

  11. Decision of Lead-Time Compression and Stable Operation of Supply Chain

    Directory of Open Access Journals (Sweden)

    Songtao Zhang

    2017-01-01

    Full Text Available A cost optimization strategy and a robust control strategy were studied to realize the low-cost robust operation of the supply chain with lead times. Firstly, for the multiple production lead times which existed in the supply chain, a corresponding inventory state model and a supply chain cost model were constructed based on the Takagi-Sugeno fuzzy control system. Then, by considering the actual inventory level, the lead-time compression cost, and the stock-out cost, a cost optimization strategy was proposed. Furthermore, a fuzzy robust control strategy was proposed to realize the flexible switching among the models. Finally, the simulation results show that the total cost of the supply chain could be reduced effectively by the cost optimization strategy, and the stable operation of the supply chain could be realized by the proposed fuzzy robust control strategy.

  12. Greater happiness for a greater number: Is that possible? If so how? (Arabic)

    NARCIS (Netherlands)

    R. Veenhoven (Ruut); E. Samuel (Emad)

    2012-01-01

    textabstractWhat is the final goal of public policy? Jeremy Bentham (1789) would say: greater happiness for a greater number. He thought of happiness as subjective enjoyment of life; in his words as “the sum of pleasures and pains”. In his time, the happiness of the great number could not be

  13. Lead Times – Their Behavior and the Impact on Planning and Control in Supply Chains

    Directory of Open Access Journals (Sweden)

    Nielsen Peter

    2017-06-01

    Full Text Available Lead times and their nature have received limited interest in literature despite their large impact on the performance and the management of supply chains. This paper presents a method and a case implementation of the same, to establish the behavior of real lead times in supply chains. The paper explores the behavior of lead times and illustrates how in one particular case they can and should be considered to be independent and identically distributed (i.i.d.. The conclusion is also that the stochastic nature of the lead times contributes more to lead time demand variance than demand variance.

  14. Reducing of Manufacturing Lead Time by Implementation of Lean Manufacturing Principles

    Directory of Open Access Journals (Sweden)

    Hussein Salem Ketan

    2015-08-01

    Full Text Available Many organizations today are interesting to implementing lean manufacturing principles that should enable them to eliminating the wastes to reducing a manufacturing lead time. This paper concentrates on increasing the competitive level of the company in globalization markets and improving of the productivity by reducing the manufacturing lead time. This will be by using the main tool of lean manufacturing which is value stream mapping (VSM to identifying all the activities of manufacturing process (value and non-value added activities to reducing elimination of wastes (non-value added activities by converting a manufacturing system to pull instead of push by applying some of pull system strategies as kanban and first on first out lane (FIFO. ARENA software is used to simulate the current and future state. This work is executed in the state company for electrical industries in Baghdad. The obtained results of the application showed that implementation of lean principles helped on reducing of a manufacturing lead time by 33%.

  15. Recent studies of lead neurotoxicity in children: old metal, new questions

    Directory of Open Access Journals (Sweden)

    David C. Bellinger

    2011-09-01

    Full Text Available Many times in the history of lead toxicology the view has prevailed that „the problem” has been solved, and that exposure to lead is no longer a major public health concern. Each time, additional research has demonstrated the prematurity of this judgment. In the last decade, an extraordinary number of new studies have illustrated that „the problem” remains, and that it has dimensions never before considered. Children’s intelligence has traditionally been considered to be the most sensitive endpoint and used as the basis for risk assessment and standard setting. For IQ, the dose-effect relationship appears to be supra-linear, with greater deficits per μg/L increment below than above 100 μg/L. Recent studies have found that greater lead exposure in early childhood is also associated with a wide variety of other outcomes, with some associations evident at biomarker levels comparable to those at which IQ deficits are observed. Among these endpoints are poorer academic achievement, ADHD, conduct disorder, and antisocial behavior. In animals, early life lead exposure has been implicated in neurodegenerative disorders later in life, perhaps via epigenetic mechanisms. Studies employing neuroimaging modalities such as volumetric, diffusion tensor, and functional MRI are providing insights into the neural bases of the cognitive impairments associated with greater lead exposure. Several recent risk assessments (e.g., EFSA, JECFA have concluded that research has yet to identify a threshold level below which lead can be considered „safe”.

  16. Fuzzy Control Model and Simulation for Nonlinear Supply Chain System with Lead Times

    Directory of Open Access Journals (Sweden)

    Songtao Zhang

    2017-01-01

    Full Text Available A new fuzzy robust control strategy for the nonlinear supply chain system in the presence of lead times is proposed. Based on Takagi-Sugeno fuzzy control system, the fuzzy control model of the nonlinear supply chain system with lead times is constructed. Additionally, we design a fuzzy robust H∞ control strategy taking the definition of maximal overlapped-rules group into consideration to restrain the impacts such as those caused by lead times, switching actions among submodels, and customers’ stochastic demands. This control strategy can not only guarantee that the nonlinear supply chain system is robustly asymptotically stable but also realize soft switching among subsystems of the nonlinear supply chain to make the less fluctuation of the system variables by introducing the membership function of fuzzy system. The comparisons between the proposed fuzzy robust H∞ control strategy and the robust H∞ control strategy are finally illustrated through numerical simulations on a two-stage nonlinear supply chain with lead times.

  17. Bioaccumulation of lead, mercury, and cadmium in the greater white-toothed shrew, Crocidura russula, from the Ebro Delta (NE Spain); Sex- and age-dependent variation

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Chardi, Alejandro [Departament de Biologia Animal (Vertebrats), Facultat de Biologia, Universitat de Barcelona, Avinguda Diagonal 645, 08028 Barcelona (Spain)]. E-mail: a.sanchez.chardi@ub.edu; Lopez-Fuster, Maria Jose [Departament de Biologia Animal (Vertebrats), Facultat de Biologia, Universitat de Barcelona, Avinguda Diagonal 645, 08028 Barcelona (Spain); Nadal, Jacint [Departament de Biologia Animal (Vertebrats), Facultat de Biologia, Universitat de Barcelona, Avinguda Diagonal 645, 08028 Barcelona (Spain)

    2007-01-15

    We quantified bioaccumulation of lead, mercury, and cadmium in bones from 105 greater white-toothed shrews (Crocidura russula) collected at the Ebro Delta, a polluted area, and the Medas Islands, a control site. Lead and mercury levels varied with site, age, and sex, although statistical significances depended on each factor. Globally, shrews from the polluted area exhibited significantly higher concentrations of Pb and Hg. Increment of Pb with age was particularly remarkable in wetland animals and was interpreted in relation to human activities, namely hunting. Unlike males, females from the Ebro Delta maintained low Hg levels, which were associated with gestation and lactation. Cadmium levels did not differ between sites, sexes, or ages. This study provides the first data on heavy metals in mammals from this wetland and suggests that C. russula is a good bioindicator of metal pollution. We concluded that sex and age may represent an important source of variation in the bioaccumulation of these metals in wild populations. - Bioaccumulation patterns of Pb and Hg reveal sex and age-related differences in the large bones of the greater white-toothed shrew from a polluted Mediterranean wetland.

  18. Determination of new time-temperature-transformation diagrams for lead-calcium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, F.; Lambertin, M. [Arts et Metiers Paristech, LaBoMaP, ENSAM, Rue porte de Paris, 71250 Cluny (France); Delfaut-Durut, L. [CEA, centre de Valduc [SEMP, LECM], 21120 Is-sur-Tille (France); Maitre, A. [SPCTS, UFR Sciences et techniques, 87060 Limoges (France); Vilasi, M. [LCSM, Universite Nancy I, 54506 Vandoeuvre les Nancy (France)

    2008-12-01

    The Pb-Ca is an age hardening alloy that allows for an increase in the hardness compared to pure lead. The hardening is obtained after different successive ageing transformations. In addition, this hardening is followed by an overageing which induces a softening. The ageing and overageing transformation mechanisms are now well identified in lead-calcium alloys. In this paper, we propose to represent the domain of stability of each transformation via time-temperature-transformation diagrams for a calcium concentration from 600 to 1280 ppm and in a range of temperatures from -20 to 180 C. These diagrams are constructed with the data obtained by in situ ageing with metallographic observations, hardness and electrical resistance measurements. The specificities of lead-calcium such as its fast ageing at ambient temperature and its overageing over time required the design of specific devices to be able to identify the characteristics of these alloys. (author)

  19. The effect of lead-based paint hazard remediation on blood lead levels of lead poisoned children in New York City.

    Science.gov (United States)

    Leighton, Jessica; Klitzman, Susan; Sedlar, Slavenka; Matte, Thomas; Cohen, Neal L

    2003-07-01

    Despite the widespread use of lead paint hazard control for children with lead poisoning, few controlled studies that estimate the effect of such control on children's blood lead levels have been published. This retrospective follow-up study examined the effects of lead hazard remediation and its timing on the blood lead levels of lead-poisoned children. From the New York City child blood lead registry, 221 children were selected who had an initial blood lead level of 20-44 micro g/dL between 1 July 1994 and 31 December 1996; were 6 months to 6 years of age; had a report of a follow-up blood lead test between 10 and 14 months after the initial test; had a lead-based paint hazard identified in the primary dwelling unit prior to the 10- to 14-month follow-up blood lead test; had resided or spent time at only one address with an identified lead-based paint hazard; and were not chelated. The decline in geometric mean blood lead levels from baseline to 10-14 months later was compared for children whose homes were remediated and whose homes were not remediated during the follow-up period. Regardless of remediation, geometric mean blood lead levels declined significantly from 24.3 micro g/dL at the initial diagnosis to 12.3 micro g/dL at the 10- to 14-month follow-up blood lead test (Premediated the geometric mean blood lead levels declined 53% compared to 41% among the 75 children whose homes were not remediated by the follow-up blood lead test, a remediation effect of approximately 20% (Premediation effect was 11%, although it was no longer significant. Race was the only factor that appeared to confound the relationship: Black children had higher follow-up blood lead levels even after controlling for other factors, including the natural logarithm of the initial blood lead level. The effect of remediation appeared to be stronger for younger (10 to remediation (within less than 3 months) appeared to have greater declines in blood lead levels at the follow-up test than

  20. Enhancing Nursing Staffing Forecasting With Safety Stock Over Lead Time Modeling.

    Science.gov (United States)

    McNair, Douglas S

    2015-01-01

    In balancing competing priorities, it is essential that nursing staffing provide enough nurses to safely and effectively care for the patients. Mathematical models to predict optimal "safety stocks" have been routine in supply chain management for many years but have up to now not been applied in nursing workforce management. There are various aspects that exhibit similarities between the 2 disciplines, such as an evolving demand forecast according to acuity and the fact that provisioning "stock" to meet demand in a future period has nonzero variable lead time. Under assumptions about the forecasts (eg, the demand process is well fit as an autoregressive process) and about the labor supply process (≥1 shifts' lead time), we show that safety stock over lead time for such systems is effectively equivalent to the corresponding well-studied problem for systems with stationary demand bounds and base stock policies. Hence, we can apply existing models from supply chain analytics to find the optimal safety levels of nurse staffing. We use a case study with real data to demonstrate that there are significant benefits from the inclusion of the forecast process when determining the optimal safety stocks.

  1. The impact of project management on nuclear construction lead times

    International Nuclear Information System (INIS)

    Radlaver, M.A.; Bauman, D.S.; Chapel, S.W.

    1985-01-01

    A two-year study of lead times for nuclear power plants found that construction time is affected by six fundamental influences. One of the six is project management. An analysis of construction management teams at 26 nuclear units found that many of the most successful shared five general characteristics: nuclear power experience, skill in project control, adaptability and initiative, commitment to success, and communication and coordination skill

  2. The Multi-Location Transshipment Problem with Positive Replenishment Lead Times

    NARCIS (Netherlands)

    Y. Gong (Yeming); E. Yucesan

    2006-01-01

    textabstractTransshipments, monitored movements of material at the same echelon of a supply chain, represent an effective pooling mechanism. With a single exception, research on transshipments overlooks replenishment lead times. The only approach for two-location inventory systems with

  3. Optimization and Customer Utilities under Dynamic Lead Time Quotation in an M/M Type Base Stock System

    Directory of Open Access Journals (Sweden)

    Koichi Nakade

    2017-01-01

    Full Text Available In a manufacturing and inventory system, information on production and order lead time helps consumers’ decision whether they receive finished products or not by considering their own impatience on waiting time. In Savaşaneril et al. (2010, the optimal dynamic lead time quotation policy in a one-stage production and inventory system with a base stock policy for maximizing the system’s profit and its properties are discussed. In this system, each arriving customer decides whether he/she enters the system based on the quoted lead time informed by the system. On the other hand, the customer’s utility may be small under the optimal quoted lead time policy because the actual lead time may be longer than the quoted lead time. We use a utility function with respect to benefit of receiving products and waiting time and propose several kinds of heuristic lead time quotation policies. These are compared with optimal policies with respect to both profits and customer’s utilities. Through numerical examples some kinds of heuristic policies have better expected utilities of customers than the optimal quoted lead time policy maximizing system’s profits.

  4. Time evolution of laser-induced breakdown spectrometry of lead

    International Nuclear Information System (INIS)

    Li Zhongwen; Zhang Jianhui

    2011-01-01

    The plasma have been generated by a pulsed Nd: YAG laser at the fundamental wavelength of 1.06 μm ablating a metal lead target in air at atmospheric pressure, and the time resolved emission spectra were gotten. Time evolution of electron temperatures were measured according to the wavelength and relative intensity of spectra; then the electron densities were obtained from the Stark broadening of Pb-line; the time evolution of electron temperatures and electron densities along the direction plumbing the target surface were imaged. The analysis of results showed that electron temperature averaged to 14500 K, electron densities up to 10 17 cm -3 . The characteristics of time evolution of electron temperature and electron density were qualitatively explained from the aspect of generation mechanism of laser-induced plasmas. (authors)

  5. Optimal base-stock policy for the inventory system with periodic review, backorders and sequential lead times

    DEFF Research Database (Denmark)

    Johansen, Søren Glud; Thorstenson, Anders

    2008-01-01

    We extend well-known formulae for the optimal base stock of the inventory system with continuous review and constant lead time to the case with periodic review and stochastic, sequential lead times. Our extension uses the notion of the 'extended lead time'. The derived performance measures...

  6. Stochastic integrated vendor–buyer model with unstable lead time and setup cost

    Directory of Open Access Journals (Sweden)

    Chandra K. Jaggi

    2011-01-01

    Full Text Available This paper presents a new vendor-buyer system where there are different objectives for both sides. The proposed method of this paper is different from the other previously published works since it considers different objectives for both sides. In this paper, the vendor’s emphasis is on the crashing of the setup cost, which not only helps him compete in the market but also provides better services to his customers; and the buyer’s aim is to reduce the lead time, which not only facilitates the buyer to fulfill the customers’ demand on time but also enables him to earn a good reputation in the market or vice versa. In the light of the above stated facts, an integrated vendor-buyer stochastic inventory model is also developed. The propsed model considers two cases for demand during lead time: Case (i Complete demand information, Case (ii Partial demand information. The proposed model jointly optimizes the buyer’s ordered quantity and lead time along with vendor’s setup cost and the number of shipments. The results are demonstrated with the help of numerical examples.

  7. A note on the catch-up time method for estimating lead or sojourn time in prostate cancer screening

    NARCIS (Netherlands)

    G. Draisma (Gerrit); J.M. van Rosmalen (Joost)

    2013-01-01

    textabstractModels of cancer screening assume that cancers are detectable by screening before being diagnosed clinically through symptoms. The duration of this preclinical phase is called sojourn time, and it determines how much diagnosis might be advanced in time by the screening test (lead time).

  8. Integrated capacity and inventory management with capacity acquisition lead times

    NARCIS (Netherlands)

    Mincsovics, G.Z.; Tan, T.; Alp, O.

    2009-01-01

    We model a make-to-stock production system that utilizes permanent and contingent capacity to meet non-stationary stochastic demand, where a constant lead time is associated with the acquisition of contingent capacity. We determine the structure of the optimal solution concerning both the

  9. Reconstructing the life-time lead exposure in children using dentine in deciduous teeth

    Energy Technology Data Exchange (ETDEWEB)

    Shepherd, Thomas J., E-mail: shepherdtj@aol.com [School of Earth and Environment, University of Leeds, Leeds LS2 9JT (United Kingdom); Dirks, Wendy [Centre for Oral Health Research, School of Dental Sciences, Newcastle University, Newcastle upon Tyne NE2 4BW (United Kingdom); Manmee, Charuwan; Hodgson, Susan [Institute of Health and Society, Newcastle University, Newcastle upon Tyne NE2 4AX (United Kingdom); Banks, David A. [School of Earth and Environment, University of Leeds, Leeds LS2 9JT (United Kingdom); Averley, Paul [Centre for Oral Health Research, School of Dental Sciences, Newcastle University, Newcastle upon Tyne NE2 4BW (United Kingdom); Queensway Dental Practice, 170 Queensway, Billingham, Teesside TS23 2NT (United Kingdom); Pless-Mulloli, Tanja [Institute of Health and Society, Newcastle University, Newcastle upon Tyne NE2 4AX (United Kingdom); Newcastle Institute for Research on Sustainability, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom)

    2012-05-15

    Data are presented to demonstrate that the circumpulpal dentine of deciduous teeth can be used to reconstruct a detailed record of childhood exposure to lead. By combining high spatial resolution laser ablation ICP-MS with dental histology, information was acquired on the concentration of lead in dentine from in utero to several years after birth, using a true time template of dentine growth. Time corrected lead analyses for pairs of deciduous molars confirmed that between-tooth variation for the same child was negligible and that meaningful exposure histories can be obtained from a single, multi-point ablation transect on longitudinal sections of individual teeth. For a laser beam of 100 {mu}m diameter, the lead signal for each ablation point represented a time span of 42 days. Simultaneous analyses for Sr, Zn and Mg suggest that the incorporation of Pb into dentine (carbonated apatite) is most likely controlled by nanocrystal growth mechanisms. The study also highlights the importance of discriminating between primary and secondary dentine and the dangers of translating lead analyses into blood lead estimates without determining the age or duration of dentine sampled. Further work is in progress to validate deciduous teeth as blood lead biomarkers. - Highlights: Black-Right-Pointing-Pointer Reconstruction of childhood exposure history to Pb using deciduous tooth dentine. Black-Right-Pointing-Pointer Pb analyses acquired for dentine growth increments of 42 days. Black-Right-Pointing-Pointer Highly correlated Pb concentration profiles for pairs of deciduous molars. Black-Right-Pointing-Pointer Data for Sr, Zn and Mg provide a model for the incorporation of Pb into dentine.

  10. Reconstructing the life-time lead exposure in children using dentine in deciduous teeth

    International Nuclear Information System (INIS)

    Shepherd, Thomas J.; Dirks, Wendy; Manmee, Charuwan; Hodgson, Susan; Banks, David A.; Averley, Paul; Pless-Mulloli, Tanja

    2012-01-01

    Data are presented to demonstrate that the circumpulpal dentine of deciduous teeth can be used to reconstruct a detailed record of childhood exposure to lead. By combining high spatial resolution laser ablation ICP-MS with dental histology, information was acquired on the concentration of lead in dentine from in utero to several years after birth, using a true time template of dentine growth. Time corrected lead analyses for pairs of deciduous molars confirmed that between-tooth variation for the same child was negligible and that meaningful exposure histories can be obtained from a single, multi-point ablation transect on longitudinal sections of individual teeth. For a laser beam of 100 μm diameter, the lead signal for each ablation point represented a time span of 42 days. Simultaneous analyses for Sr, Zn and Mg suggest that the incorporation of Pb into dentine (carbonated apatite) is most likely controlled by nanocrystal growth mechanisms. The study also highlights the importance of discriminating between primary and secondary dentine and the dangers of translating lead analyses into blood lead estimates without determining the age or duration of dentine sampled. Further work is in progress to validate deciduous teeth as blood lead biomarkers. - Highlights: ► Reconstruction of childhood exposure history to Pb using deciduous tooth dentine. ► Pb analyses acquired for dentine growth increments of 42 days. ► Highly correlated Pb concentration profiles for pairs of deciduous molars. ► Data for Sr, Zn and Mg provide a model for the incorporation of Pb into dentine.

  11. The effect of lead-based paint hazard remediation on blood lead levels of lead poisoned children in New York City

    International Nuclear Information System (INIS)

    Leighton, Jessica; Klitzman, Susan; Sedlar, Slavenka; Matte, Thomas; Cohen, Neal L.

    2003-01-01

    to 72 months old) children (P=0.06). While children in homes with earlier remediation (within less than 3 months) appeared to have greater declines in blood lead levels at the follow-up test than children in homes with later remediation (after 3 or more months), this trend was not significant when controlling for confounding factors. The findings of this study suggest that early identification of lead-poisoned children and timely investigation and abatement of hazards contribute to reducing blood lead levels. However, the apparent effect is modest and further research is needed to systematically test and improve the effectiveness of lead hazard controls

  12. Strategic Inventory Positioning in BOM with Multiple Parents Using ASR Lead Time

    Directory of Open Access Journals (Sweden)

    Jingjing Jiang

    2016-01-01

    Full Text Available In order to meet the lead time that the customers require, work-in-process inventory (WIPI is necessary at almost every station in most make-to-order manufacturing. Depending on the station network configuration and lead time at each station, some of the WIPI do not contribute to reducing the manufacturing lead time of the final product at all. Therefore, it is important to identify the optimal set of stations to hold WIPI such that the total inventory holding cost is minimized, while the required due date for the final product is met. The authors have presented a model to determine the optimal position and quantity of WIPI for a given simple bill of material (S-BOM, in which any part in the BOM has only one immediate parent node. In this paper, we extend the previous study to the general BOM (G-BOM in which parts in the BOM can have more than one immediate parent and present a new solution procedure using genetic algorithm.

  13. Greater-than-Class C low-level radioactive waste characterization. Appendix A-2: Timing of greater-than-Class C low-level radioactive waste from nuclear power plants

    International Nuclear Information System (INIS)

    Steinke, W.F.

    1994-09-01

    Planning for the storage or disposal of greater-than-Class C low-level radioactive waste (GTCC LLW) requires characterization of that waste. Timing, or the date the waste will require storage or disposal, is an integral aspect of that planning. The majority of GTCC LLW is generated by nuclear power plants, and the length of time a reactor remains operational directly affects the amount of GTCC waste expected from that reactor. This report uses data from existing literature to develop high, base, and low case estimates for the number of plants expected to experience (a) early shutdown, (b) 40-year operation, or (c) life extension to 60-year operation. The discussion includes possible effects of advanced light water reactor technology on future GTCC LLW generation. However, the main focus of this study is timing for shutdown of current technology reactors that are under construction or operating

  14. A Time-Walk Correction Method for PET Detectors Based on Leading Edge Discriminators.

    Science.gov (United States)

    Du, Junwei; Schmall, Jeffrey P; Judenhofer, Martin S; Di, Kun; Yang, Yongfeng; Cherry, Simon R

    2017-09-01

    The leading edge timing pick-off technique is the simplest timing extraction method for PET detectors. Due to the inherent time-walk of the leading edge technique, corrections should be made to improve timing resolution, especially for time-of-flight PET. Time-walk correction can be done by utilizing the relationship between the threshold crossing time and the event energy on an event by event basis. In this paper, a time-walk correction method is proposed and evaluated using timing information from two identical detectors both using leading edge discriminators. This differs from other techniques that use an external dedicated reference detector, such as a fast PMT-based detector using constant fraction techniques to pick-off timing information. In our proposed method, one detector was used as reference detector to correct the time-walk of the other detector. Time-walk in the reference detector was minimized by using events within a small energy window (508.5 - 513.5 keV). To validate this method, a coincidence detector pair was assembled using two SensL MicroFB SiPMs and two 2.5 mm × 2.5 mm × 20 mm polished LYSO crystals. Coincidence timing resolutions using different time pick-off techniques were obtained at a bias voltage of 27.5 V and a fixed temperature of 20 °C. The coincidence timing resolution without time-walk correction were 389.0 ± 12.0 ps (425 -650 keV energy window) and 670.2 ± 16.2 ps (250-750 keV energy window). The timing resolution with time-walk correction improved to 367.3 ± 0.5 ps (425 - 650 keV) and 413.7 ± 0.9 ps (250 - 750 keV). For comparison, timing resolutions were 442.8 ± 12.8 ps (425 - 650 keV) and 476.0 ± 13.0 ps (250 - 750 keV) using constant fraction techniques, and 367.3 ± 0.4 ps (425 - 650 keV) and 413.4 ± 0.9 ps (250 - 750 keV) using a reference detector based on the constant fraction technique. These results show that the proposed leading edge based time-walk correction method works well. Timing resolution obtained

  15. Lead Intoxication in Children in Birmingham

    Science.gov (United States)

    Betts, P. R.; Astley, R.; Raine, D. N.

    1973-01-01

    Of 38 children investigated between 1966 and 1971 who had a blood lead concentration greater than 37 μg/100 ml eight had encephalopathy and one died; all these eight had a blood lead concentration of 99 μg/100 ml or above. Blood lead levels are related to haemoglobin concentrations and anaemia is common in children with blood lead concentrations of 37-60 μg/100 ml, levels previously accepted as harmless. Children with blood lead concentrations greater than 60 μg/100 ml show radiological evidence of lead intoxication, and treatment for this should be considered when blood lead concentration exceeds 37 μg/100 ml. Children presenting with unexplained encephalopathy should be radiographed for evidence of lead intoxication. ImagesFIG. 2FIG. 1 PMID:4691065

  16. Synergy effects of fluoxetine and variability in temperature lead to proportionally greater fitness costs in Daphnia: A multigenerational test.

    Science.gov (United States)

    Barbosa, Miguel; Inocentes, Núrya; Soares, Amadeu M V M; Oliveira, Miguel

    2017-12-01

    Increased variability in water temperature is predicted to impose disproportionally greater fitness costs than mean increase in temperature. Additionally, water contaminants are currently a major source of human-induced stress likely to produce fitness costs. Global change models forecast an increase in these two human-induced stressors. Yet, in spite the growing interest in understanding how organisms respond to global change, the joint fitness effects of water pollution and increased variability in temperature remain unclear. Here, using a multigenerational design, we test the hypothesis that exposure to high concentrations of fluoxetine, a human medicine commonly found in freshwater systems, causes increased lifetime fitness costs, when associated with increased variability in temperature. Although fluoxetine and variability in temperature elicited some fitness cost when tested alone, when both stressors acted together the costs were disproportionally greater. The combined effect of fluoxetine and variability in temperature led to a reduction of 37% in lifetime reproductive success and a 17.9% decrease in population growth rate. Interestingly, fluoxetine and variability in temperature had no effect on the probability of survival. Freshwater systems are among the most imperilled ecosystems, often exposed to multiple human-induced stressors. Our results indicate that organisms face greater fitness risk when exposed to multiple stressors at the same time than when each stress acts alone. Our study highlights the importance of using a multi-generational approach to fully understand individual environmental tolerance and its responses to a global change scenario in aquatic systems. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Defense Inventory: Opportunities Exist to Improve the Management of DOD's Acquisition Lead Times for Spare Parts

    National Research Council Canada - National Science Library

    2007-01-01

    .... Management of inventory acquisition lead times is important in maintaining cost-effective inventories, budgeting, and having material available when needed, as lead times are DOD's best estimate...

  18. Use of Six Sigma Methodology to Reduce Appointment Lead-Time in Obstetrics Outpatient Department.

    Science.gov (United States)

    Ortiz Barrios, Miguel A; Felizzola Jiménez, Heriberto

    2016-10-01

    This paper focuses on the issue of longer appointment lead-time in the obstetrics outpatient department of a maternal-child hospital in Colombia. Because of extended appointment lead-time, women with high-risk pregnancy could develop severe complications in their health status and put their babies at risk. This problem was detected through a project selection process explained in this article and to solve it, Six Sigma methodology has been used. First, the process was defined through a SIPOC diagram to identify its input and output variables. Second, six sigma performance indicators were calculated to establish the process baseline. Then, a fishbone diagram was used to determine the possible causes of the problem. These causes were validated with the aid of correlation analysis and other statistical tools. Later, improvement strategies were designed to reduce appointment lead-time in this department. Project results evidenced that average appointment lead-time reduced from 6,89 days to 4,08 days and the deviation standard dropped from 1,57 days to 1,24 days. In this way, the hospital will serve pregnant women faster, which represents a risk reduction of perinatal and maternal mortality.

  19. Nesting success and resource selection of Greater Sage-Grouse [chapter 8

    Science.gov (United States)

    Nicholas W. Kaczor; Kent C. Jensen; Robert W. Klaver; Mark A. Rumble; Katie M. Herman-Brunson; Christopher C. Swanson

    2011-01-01

    Declines of Greater Sage-Grouse (Centrocercus urophasianus) in South Dakota are a concern because further population declines may lead to isolation from populations in Wyoming and Montana. Furthermore, little information exists about reproductive ecology and resource selection of sage grouse on the eastern edge of their distribution. We investigated Greater Sage-Grouse...

  20. Overestimated lead times in cancer screening has led to substantial underestimation of overdiagnosis

    DEFF Research Database (Denmark)

    Zahl, P-H; Juhl Jørgensen, Karsten; Gøtzsche, P C

    2013-01-01

    Published lead time estimates in breast cancer screening vary from 1 to 7 years and the percentages of overdiagnosis vary from 0 to 75%. The differences are usually explained as random variations. We study how much can be explained by using different definitions and methods.......Published lead time estimates in breast cancer screening vary from 1 to 7 years and the percentages of overdiagnosis vary from 0 to 75%. The differences are usually explained as random variations. We study how much can be explained by using different definitions and methods....

  1. The effects of lead time and visual aids in TTO valuation: a study of the EQ-VT framework

    NARCIS (Netherlands)

    N. Luo (Nan); M. Li (Minghui); E.A. Stolk (Elly); N. Devlin (Nancy)

    2013-01-01

    markdownabstract__Abstract__ __Background__ The effect of lead time in time trade-off (TTO) valuation is not well understood. The purpose of this study was to investigate the effects on health-state valuation of the length of lead time and the way the lead-time TTO task is displayed visually.

  2. PRENATAL ETHANOL EXPOSURE LEADS TO GREATER ETHANOL-INDUCED APPETITIVE REINFORCEMENT

    Science.gov (United States)

    Pautassi, Ricardo M.; Nizhnikov, Michael E.; Spear, Norman E.; Molina, Juan C.

    2012-01-01

    Prenatal ethanol significantly heightens later alcohol consumption, but the mechanisms that underlie this phenomenon are poorly understood. Little is known about the basis of this effect of prenatal ethanol on the sensitivity to ethanol’s reinforcing effects. One possibility is that prenatal ethanol exposure makes subjects more sensitive to the appetitive effects of ethanol or less sensitive to ethanol’s aversive consequences. The present study assessed ethanol-induced second-order conditioned place preference (CPP) and aversion and ethanol-induced conditioned taste aversion (CTA) in infant rats prenatally exposed to ethanol (2.0 g/kg) or vehicle (water) or left untreated. The involvement of the κ opioid receptor system in ethanol-induced CTA was also explored. When place conditioning occurred during the ascending limb of the blood-ethanol curve (Experiment 1), the pups exposed to ethanol in utero exhibited greater CPP than untreated controls, with a shift to the right of the dose-response curve. Conditioning during a later phase of intoxication (30–45 min post-administration; Experiment 2) resulted in place aversion in control pups exposed to vehicle during late gestation but not in pups that were exposed to ethanol in utero. Ethanol induced a reliable and similar CTA (Experiment 3) in the pups treated with vehicle or ethanol during gestation, and CTA was insensitive to κ antagonism. These results suggest that brief exposure to a moderate ethanol dose during late gestation promotes ethanol-mediated reinforcement and alters the expression of conditioned aversion by ethanol. This shift in the motivational reactivity to ethanol may be an underlying basis of the effect of prenatal ethanol on later ethanol acceptance. PMID:22698870

  3. Effects of iron deficiency on the absorption and distribution of lead and cadmium in rats

    International Nuclear Information System (INIS)

    Ragan, H.A.

    1977-01-01

    In order to evaluate the effects of iron deficiency on the absorption of pollutant metals, an iron-deficient diet was fed to young rats until their tissue-iron stores were depleted. Prior to the development of anemia, the iron-deficient rats and littermate controls were administered an intragastric gavage of lead-210 or cadmium-109 and were killed 48 hr later. The body burden of lead was approximately 6 times greater, and that of cadmium approximately 7 times greater, in iron-deficient rats than in the controls. No consistent effects were observed on concentrations of serum total lipids or serum proteins nor on protein electrophoretic patterns in rats with a deficit in iron stores

  4. The influence of time on lead toxicity and bioaccumulation determined by the OECD earthworm toxicity test

    International Nuclear Information System (INIS)

    Davies, N.A.Nicola A.; Hodson, M.E.Mark E.; Black, S.Stuart

    2003-01-01

    Timing of lead addition and worms to soil affects the response of the worms to soil affects the response of the worms to lead. - Internationally agreed standard protocols for assessing chemical toxicity of contaminants in soil to worms assume that the test soil does not need to equilibrate with the chemical to be tested prior to the addition of the test organisms and that the chemical will exert any toxic effect upon the test organism within 28 days. Three experiments were carried out to investigate these assumptions. The first experiment was a standard toxicity test where lead nitrate was added to a soil in solution to give a range of concentrations. The mortality of the worms and the concentration of lead in the survivors were determined. The LC 50 s for 14 and 28 days were 5311 and 5395 μg Pb g -1 soil respectively. The second experiment was a timed lead accumulation study with worms cultivated in soil containing either 3000 or 5000 μg Pb g -1 soil . The concentration of lead in the worms was determined at various sampling times. Uptake at both concentrations was linear with time. Worms in the 5000 μg g -1 soil accumulated lead at a faster rate (3.16 μg Pb g -1 tissue day -1 ) than those in the 3000 μg g -1 soil (2.21 μg Pb g -1 tissue day -1 ). The third experiment was a timed experiment with worms cultivated in soil containing 7000 μg Pb g -1 soil . Soil and lead nitrate solution were mixed and stored at 20 deg. C. Worms were added at various times over a 35-day period. The time to death increased from 23 h, when worms were added directly after the lead was added to the soil, to 67 h when worms were added after the soil had equilibrated with the lead for 35 days. In artificially Pb-amended soils the worms accumulate Pb over the duration of their exposure to the Pb. Thus time limited toxicity tests may be terminated before worm body load has reached a toxic level. This could result in under-estimates of the toxicity of Pb to worms. As the equilibration

  5. Lead-Binding Proteins: A Review

    Directory of Open Access Journals (Sweden)

    Harvey C. Gonick

    2011-01-01

    Full Text Available Lead-binding proteins are a series of low molecular weight proteins, analogous to metallothionein, which segregate lead in a nontoxic form in several organs (kidney, brain, lung, liver, erythrocyte. Whether the lead-binding proteins in every organ are identical or different remains to be determined. In the erythrocyte, delta-aminolevulinic acid dehydratase (ALAD isoforms have commanded the greatest attention as proteins and enzymes that are both inhibitable and inducible by lead. ALAD-2, although it binds lead to a greater degree than ALAD-1, appears to bind lead in a less toxic form. What may be of greater significance is that a low molecular weight lead-binding protein, approximately 10 kDa, appears in the erythrocyte once blood lead exceeds 39 μg/dL and eventually surpasses the lead-binding capacity of ALAD. In brain and kidney of environmentally exposed humans and animals, a cytoplasmic lead-binding protein has been identified as thymosin β4, a 5 kDa protein. In kidney, but not brain, another lead-binding protein has been identified as acyl-CoA binding protein, a 9 kDa protein. Each of these proteins, when coincubated with liver ALAD and titrated with lead, diminishes the inhibition of ALAD by lead, verifying their ability to segregate lead in a nontoxic form.

  6. Inventory control in multi-echelon divergent systems with random lead times

    NARCIS (Netherlands)

    Heijden, van der M.C.; Diks, E.B.; Kok, de A.G.

    1996-01-01

    This paper deals with integral inventory control in multi-echelon divergent systems with stochastic lead times. The policy considered is an echelon stock, periodic review, order-up-to (R, S) policy. A computational method is derived to obtain the order-up-to level and the allocation fractions

  7. Inventory control in multi-echelon divergent systems with random lead times

    NARCIS (Netherlands)

    van der Heijden, Matthijs C.; Diks, Erik; de Kok, Ton

    1999-01-01

    This paper deals with integral inventory control in multi-echelon divergent systems with stochastic lead times. The policy considered is an echelon stock, periodic review, order-up-to (R, S) policy. A computational method is derived to obtain the order-up-to level and the allocation fractions

  8. Quality Improvement, Inventory Management, Lead Time Reduction and Production Scheduling in High-Mix Manufacturing Environments

    Science.gov (United States)

    2017-01-13

    Quality Improvement , Inventory Management, Lead Time Reduction and Production Scheduling in High-mix Manufacturing Environments by Sean Daigle B.S...Mechanical Engineering Chairman, Department Committee on Graduate Theses 2 Quality Improvement , Inventory Management, Lead Time Reduction and... Production Scheduling in High-mix Manufacturing Environments by Sean Daigle Submitted to the Department of Mechanical Engineering on January 13, 2017, in

  9. Modeling and analysis for determining optimal suppliers under stochastic lead times

    DEFF Research Database (Denmark)

    Abginehchi, Soheil; Farahani, Reza Zanjirani

    2010-01-01

    systems. The item acquisition lead times of suppliers are random variables. Backorder is allowed and shortage cost is charged based on not only per unit in shortage but also per time unit. Continuous review (s,Q) policy has been assumed. When the inventory level depletes to a reorder level, the total...... order is split among n suppliers. Since the suppliers have different characteristics, the quantity ordered to different suppliers may be different. The problem is to determine the reorder level and quantity ordered to each supplier so that the expected total cost per time unit, including ordering cost...

  10. Australian atmospheric lead deposition reconstructed using lead concentrations and isotopic compositions of archival lichen and fungi

    International Nuclear Information System (INIS)

    Wu, Liqin; Taylor, Mark Patrick; Handley, Heather K.; Wu, Michael

    2016-01-01

    Lead concentrations and their isotopic compositions were measured in lichen genera Cladonia and Usnea and fungi genus Trametes from the Greater Sydney region (New South Wales, Australia) that had been collected and archived over the past 120 years. The median lead concentrations were elevated in lichens and fungi prior to the introduction of leaded petrol (Cladonia 12.5 mg/kg; Usnea 15.6 mg/kg; Trametes 1.85 mg/kg) corresponding to early industrial development. During the period of leaded petrol use in Australian automobiles from 1932 to 2002, total median lead concentrations rose: Cladonia 18.8 mg/kg; Usnea 21.5 mg/kg; Trametes 4.3 mg/kg. Following the cessation of leaded petrol use, median total lead concentrations decreased sharply in the 2000s: Cladonia 4.8 mg/kg; Usnea 1.7 mg/kg. The lichen and fungi isotopic compositions reveal a significant decrease in "2"0"6Pb/"2"0"7Pb ratios from the end of 19th century to the 1970s. The following decades were characterised by lower allowable levels of lead additive in fuel and the introduction of unleaded petrol in 1985. The environmental response to these regulatory changes was that lichen and fungi "2"0"6Pb/"2"0"7Pb ratios increased, particularly from 1995 onwards. Although the lead isotope ratios of lichens continued to increase in the 2000s they do not return to pre-leaded petrol values. This demonstrates that historic leaded petrol emissions, inter alia other sources, remain a persistent source of anthropogenic contamination in the Greater Sydney region. - Highlights: • Total lead and isotopic composition can be measured in historic lichen and fungi. • Historic lichen and fungi samples can distinguish polluted and unpolluted areas. • Former leaded petrol depositions remain a significant environmental contaminant. - Analysis of a 120-year record of lichens and fungi from the Greater Sydney basin reveal marked shifts in total lead concentrations and lead isotope ratios in response to geogenic inputs

  11. The Time, Space and Matter of Leading

    DEFF Research Database (Denmark)

    Jørgensen, Kenneth Mølbjerg

    2018-01-01

    This paper develops an ethical framework of leadership learning from Hannah Arendt’s writing. The intention is to identify important principles of a framework of leadership leading that help empower actors to lead themselves and to engage, interact, influence and inspire others through...

  12. Nuclear reactors' construction costs: The role of lead-time, standardization and technological progress

    International Nuclear Information System (INIS)

    Berthelemy, Michel; Escobar Rangel, Lina

    2013-01-01

    This paper provides the first comparative analysis of nuclear reactor construction costs in France and the United States. Studying the cost of nuclear power has often been a challenge, owing to the lack of reliable data sources and heterogeneity between countries, as well as the long time horizon which requires controlling for input prices and structural changes. We build a simultaneous system of equations for overnight costs and construction time (lead-time) to control for endogeneity, using expected demand variation as an instrument. We argue that benefits from nuclear reactor program standardization can arise through short term coordination gains, when the diversity of nuclear reactors' technologies under construction is low, or through long term benefits from learning spillovers from past reactor construction experience, if those spillovers are limited to similar reactors. We find that overnight construction costs benefit directly from learning spillovers but that these spillovers are only significant for nuclear models built by the same Architect-Engineer (A- E). In addition, we show that the standardization of nuclear reactors under construction has an indirect and positive effect on construction costs through a reduction in lead-time, the latter being one of the main drivers of construction costs. Conversely, we also explore the possibility of learning by searching and find that, contrary to other energy technologies, innovation leads to construction costs increases. (authors)

  13. Rumination time around calving: an early signal to detect cows at greater risk of disease.

    Science.gov (United States)

    Calamari, L; Soriani, N; Panella, G; Petrera, F; Minuti, A; Trevisi, E

    2014-01-01

    The main objective of this experiment was to evaluate the use of rumination time (RT) during the peripartum period as a tool for early disease detection. The study was carried out in an experimental freestall barn and involved 23 Italian Friesian cows (9 primiparous and 14 multiparous). The RT was continuously recorded by using an automatic system (Hr-Tag, SCR Engineers Ltd., Netanya, Israel), and data were summarized in 2-h intervals. Blood samples were collected from 30 d before calving to 42 d in milk (DIM) to assess biochemical indicators related to energy, protein, and mineral metabolism, as well as markers of inflammation and some enzyme activities. The liver functionality index, which includes some negative acute-phase proteins and related parameters (albumin, cholesterol, and bilirubin), was used to evaluate the severity of inflammatory conditions occurring around calving. The cows were retrospectively categorized according to RT observed between 3 and 6 DIM into those with the lowest (L) and highest (H) RT. The average RT before calving (-20 to -2d) was 479 min/d (range 264 to 599), reached a minimum value at calving (30% of RT before calving), and was nearly stable after 15 DIM (on average 452 min/d). Milk yield in early lactation (on average 26.8 kg/d) was positively correlated with RT (r = 0.33). After calving, compared with H cows, the L cows had higher values of haptoglobin (0.61 and 0.34 g/L at 10 DIM in L and H, respectively) for a longer time, had a greater increase in total bilirubin (9.5 and 5.7 μmol/L at 5 DIM in L and H), had greater reductions of albumin (31.2 and 33.5 g/L at 10 DIM in L and H) and paraoxonase (54 and 76 U/ml at 10 DIM in L and H), and had a slower increase of total cholesterol (2.7 and 3.2 mmol/L at 20 DIM in L and H). Furthermore, a lower average value of liver functionality index was observed in L (-6.97) compared with H (-1.91) cows. These results suggest that severe inflammation around parturition is associated with a

  14. Sulfation in lead-acid batteries

    Science.gov (United States)

    Catherino, Henry A.; Feres, Fred F.; Trinidad, Francisco

    Virtually, all military land vehicle systems use a lead-acid battery to initiate an engine start. The maintainability of these batteries and as a consequence, system readiness, has suffered from a lack of understanding of the reasons for battery failure. Often, the term most commonly heard for explaining the performance degradation of lead-acid batteries is the word, sulfation. Sulfation is a residual term that came into existence during the early days of lead-acid battery development. The usage is part of the legend that persists as a means for interpreting and justifying the eventual performance deterioration and failure of lead-acid batteries. The usage of this term is confined to the greater user community and, over time, has encouraged a myriad of remedies for solving sulfation problems. One can avoid the connotations associated with the all-inclusive word, sulfation by visualizing the general "sulfation" effect in terms of specific mechanistic models. Also, the mechanistic models are essential for properly understanding the operation and making proper use this battery system. It is evident that the better the model, the better the level of understanding.

  15. Simultaneous calibration of ensemble river flow predictions over an entire range of lead times

    Science.gov (United States)

    Hemri, S.; Fundel, F.; Zappa, M.

    2013-10-01

    Probabilistic estimates of future water levels and river discharge are usually simulated with hydrologic models using ensemble weather forecasts as main inputs. As hydrologic models are imperfect and the meteorological ensembles tend to be biased and underdispersed, the ensemble forecasts for river runoff typically are biased and underdispersed, too. Thus, in order to achieve both reliable and sharp predictions statistical postprocessing is required. In this work Bayesian model averaging (BMA) is applied to statistically postprocess ensemble runoff raw forecasts for a catchment in Switzerland, at lead times ranging from 1 to 240 h. The raw forecasts have been obtained using deterministic and ensemble forcing meteorological models with different forecast lead time ranges. First, BMA is applied based on mixtures of univariate normal distributions, subject to the assumption of independence between distinct lead times. Then, the independence assumption is relaxed in order to estimate multivariate runoff forecasts over the entire range of lead times simultaneously, based on a BMA version that uses multivariate normal distributions. Since river runoff is a highly skewed variable, Box-Cox transformations are applied in order to achieve approximate normality. Both univariate and multivariate BMA approaches are able to generate well calibrated probabilistic forecasts that are considerably sharper than climatological forecasts. Additionally, multivariate BMA provides a promising approach for incorporating temporal dependencies into the postprocessed forecasts. Its major advantage against univariate BMA is an increase in reliability when the forecast system is changing due to model availability.

  16. Contaminated lead environments of man: reviewing the lead isotopic evidence in sediments, peat, and soils for the temporal and spatial patterns of atmospheric lead pollution in Sweden.

    Science.gov (United States)

    Bindler, Richard

    2011-08-01

    Clair Patterson and colleagues demonstrated already four decades ago that the lead cycle was greatly altered on a global scale by humans. Moreover, this change occurred long before the implementation of monitoring programs designed to study lead and other trace metals. Patterson and colleagues also developed stable lead isotope analyses as a tool to differentiate between natural and pollution-derived lead. Since then, stable isotope analyses of sediment, peat, herbaria collections, soils, and forest plants have given us new insights into lead biogeochemical cycling in space and time. Three important conclusions from our studies of lead in the Swedish environment conducted over the past 15 years, which are well supported by extensive results from elsewhere in Europe and in North America, are: (1) lead deposition rates at sites removed from major point sources during the twentieth century were about 1,000 times higher than natural background deposition rates a few thousand years ago (~10 mg Pb m(-2) year(-1) vs. 0.01 mg Pb m(-2) year(-1)), and even today (~1 mg Pb m(-2) year(-1)) are still almost 100 times greater than natural rates. This increase from natural background to maximum fluxes is similar to estimated changes in body burdens of lead from ancient times to the twentieth century. (2) Stable lead isotopes ((206)Pb/(207)Pb ratios shown in this paper) are an effective tool to distinguish anthropogenic lead from the natural lead present in sediments, peat, and soils for both the majority of sites receiving diffuse inputs from long range and regional sources and for sites in close proximity to point sources. In sediments >3,500 years and in the parent soil material of the C-horizon, (206)Pb/(207)Pb ratios are higher, 1.3 to >2.0, whereas pollution sources and surface soils and peat have lower ratios that have been in the range 1.14-1.18. (3) Using stable lead isotopes, we have estimated that in southern Sweden the cumulative anthropogenic burden of

  17. Relationship between soil lead and airborne lead concentrations at Springfield, Missouri, USA

    Energy Technology Data Exchange (ETDEWEB)

    Sheets, R W; Kyger, J R; Biagioni, R N; Probst, S [Department of Chemistry, Southwest Missouri State University, 65804 Springfield, MO (United States); Boyer, R; Barke, K [Greene County Health Department, 65802 Springfield, MO (United States)

    2001-04-23

    This study tests whether lead deposited to soil from automobiles during past years in a medium-sized US city (population 150000) may present a current health risk. It examines the relationship between current soil lead concentrations at nine locations within the city of Springfield, Missouri, and airborne lead levels measured at the same locations during years (1975-1981) when lead emissions from automobiles were much greater than at present. A strong, significant correlation is found between soil and airborne lead levels at eight of the sites (r=0.91, P<0.005 for soil lead vs. 1979 airborne lead), in low-traffic areas as well as in areas adjacent to heavy traffic flow. Residual lead concentrations in these soils are relatively low, even for the high-traffic sites, as expected for a medium sized city.

  18. Relationship between soil lead and airborne lead concentrations at Springfield, Missouri, USA.

    Science.gov (United States)

    Sheets, R W; Kyger, J R; Biagioni, R N; Probst, S; Boyer, R; Barke, K

    2001-04-23

    This study tests whether lead deposited to soil from automobiles during past years in a medium-sized US city (population 150,000) may present a current health risk. It examines the relationship between current soil lead concentrations at nine locations within the city of Springfield, Missouri, and airborne lead levels measured at the same locations during years (1975-1981) when lead emissions from automobiles were much greater than at present. A strong, significant correlation is found between soil and airborne lead levels at eight of the sites (r = 0.91, P lead vs. 1979 airborne lead), in low-traffic areas as well as in areas adjacent to heavy traffic flow. Residual lead concentrations in these soils are relatively low, even for the high-traffic sites, as expected for a medium sized city.

  19. Verification of short lead time forecast models: applied to Kp and Dst forecasting

    Science.gov (United States)

    Wintoft, Peter; Wik, Magnus

    2016-04-01

    In the ongoing EU/H2020 project PROGRESS models that predicts Kp, Dst, and AE from L1 solar wind data will be used as inputs to radiation belt models. The possible lead times from L1 measurements are shorter (10s of minutes to hours) than the typical duration of the physical phenomena that should be forecast. Under these circumstances several metrics fail to single out trivial cases, such as persistence. In this work we explore metrics and approaches for short lead time forecasts. We apply these to current Kp and Dst forecast models. This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 637302.

  20. The refining of secondary lead for use in advanced lead-acid batteries

    International Nuclear Information System (INIS)

    Ellis, Timothy W.; Mirza, Abbas H.

    2010-01-01

    Secondary lead, i.e. material produced by the recycling of lead-acid batteries has become the primary source of lead in much of the world. This has been important to the secondary lead industry as other uses have dwindled, e.g. lead based pigments, chemicals, fuel additives, solders and CRT glasses. Presently, battery manufacturing accounts for greater than 80% of lead consumption while recycled lead accounts for approximately the same market share of lead supply. These two facts strongly demonstrate the battery manufacturing and recycled lead are intimately coupled in everyday life. In this paper we will explore how recycled lead has become the material of choice for battery construction through the development of a recovery and refining process that exceeds the industries requirements. Particular focus will be on addressing the results presented by Prengaman on the effects of contaminant or tramp elements on gassing in lead-acid batteries. (author)

  1. Tunneling Flight Time, Chemistry, and Special Relativity.

    Science.gov (United States)

    Petersen, Jakob; Pollak, Eli

    2017-09-07

    Attosecond ionization experiments have not resolved the question "What is the tunneling time?". Different definitions of tunneling time lead to different results. Second, a zero tunneling time for a material particle suggests that the nonrelativistic theory includes speeds greater than the speed of light. Chemical reactions, occurring via tunneling, should then not be considered in terms of a nonrelativistic quantum theory calling into question quantum dynamics computations on tunneling reactions. To answer these questions, we define a new experimentally measurable paradigm, the tunneling flight time, and show that it vanishes for scattering through an Eckart or a square barrier, irrespective of barrier length or height, generalizing the Hartman effect. We explain why this result does not lead to experimental measurement of speeds greater than the speed of light. We show that this tunneling is an incoherent process by comparing a classical Wigner theory with exact quantum mechanical computations.

  2. Optimal Ordering Policy and Coordination Mechanism of a Supply Chain with Controllable Lead-Time-Dependent Demand Forecast

    Directory of Open Access Journals (Sweden)

    Hua-Ming Song

    2011-01-01

    Full Text Available This paper investigates the ordering decisions and coordination mechanism for a distributed short-life-cycle supply chain. The objective is to maximize the whole supply chain's expected profit and meanwhile make the supply chain participants achieve a Pareto improvement. We treat lead time as a controllable variable, thus the demand forecast is dependent on lead time: the shorter lead time, the better forecast. Moreover, optimal decision-making models for lead time and order quantity are formulated and compared in the decentralized and centralized cases. Besides, a three-parameter contract is proposed to coordinate the supply chain and alleviate the double margin in the decentralized scenario. In addition, based on the analysis of the models, we develop an algorithmic procedure to find the optimal ordering decisions. Finally, a numerical example is also presented to illustrate the results.

  3. Nuclear reactors' construction costs: The role of lead-time, standardization and technological progress

    International Nuclear Information System (INIS)

    Berthélemy, Michel; Escobar Rangel, Lina

    2015-01-01

    This paper provides an econometric analysis of nuclear reactor construction costs in France and the United States based on overnight costs data. We build a simultaneous system of equations for overnight costs and construction time (lead-time) to control for endogeneity, using change in expected electricity demand as instrument. We argue that the construction of nuclear reactors can benefit from standardization gains through two channels. First, short term coordination benefits can arise when the diversity of nuclear reactors' designs under construction is low. Second, long term benefits can occur due to learning spillovers from past constructions of similar reactors. We find that construction costs benefit directly from learning spillovers but that these spillovers are only significant for nuclear models built by the same Architect–Engineer. In addition, we show that the standardization of nuclear reactors under construction has an indirect and positive effect on construction costs through a reduction in lead-time, the latter being one of the main drivers of construction costs. Conversely, we also explore the possibility of learning by searching and find that, contrary to other energy technologies, innovation leads to construction costs increases. -- Highlights: •This paper analyses the determinants of nuclear reactors construction costs and lead-time. •We study short term (coordination gains) and long term (learning by doing) benefits of standardization in France and the US. •Results show that standardization of nuclear programs is a key factor for reducing construction costs. •We also suggest that technological progress has contributed to construction costs escalation

  4. Changes in time-use and drug use by young adults in poor neighbourhoods of Greater Buenos Aires, Argentina, after the political transitions of 2001-2002: Results of a survey.

    Science.gov (United States)

    Rossi, Diana; Zunino Singh, Dhan; Pawlowicz, María Pía; Touzé, Graciela; Bolyard, Melissa; Mateu-Gelabert, Pedro; Sandoval, Milagros; Friedman, Samuel R

    2011-01-20

    In some countries, "Big Events" like crises and transitions have been followed by large increases in drug use, drug injection and HIV/AIDS. Argentina experienced an economic crisis and political transition in 2001/2002 that affected how people use their time. This paper studies how time use changes between years 2001 and 2004, subsequent to these events, were associated with drug consumption in poor neighbourhoods of Greater Buenos Aires. In 2003-2004, 68 current injecting drug users (IDUs) and 235 young non-IDUs, aged 21-35, who lived in impoverished drug-impacted neighbourhoods in Greater Buenos Aires, were asked about time use then and in 2001. Data on weekly hours spent working or looking for work, doing housework/childcare, consuming drugs, being with friends, and hanging out in the neighbourhood, were studied in relation to time spent using drugs. Field observations and focus groups were also conducted. After 2001, among both IDUs and non-IDUs, mean weekly time spent working declined significantly (especially among IDUs); time spent looking for work increased, and time spent with friends and hanging out in the neighbourhood decreased.We found no increase in injecting or non-injecting drug consumption after 2001. Subjects most affected by the way the crises led to decreased work time and/or to increased time looking for work--and by the associated increase in time spent in one's neighbourhood--were most likely to increase their time using drugs. Time use methods are useful to study changes in drug use and their relationships to every day life activities. In these previously-drug-impacted neighbourhoods, the Argentinean crisis did not lead to an increase in drug use, which somewhat contradicts our initial expectations. Nevertheless, those for whom the crises led to decreased work time, increased time looking for work, and increased time spent in indoor or outdoor neighbourhood environments, were likely to spend more time using drugs. These data suggest that

  5. Changes in time-use and drug use by young adults in poor neighbourhoods of Greater Buenos Aires, Argentina, after the political transitions of 2001-2002: Results of a survey

    Directory of Open Access Journals (Sweden)

    Mateu-Gelabert Pedro

    2011-01-01

    Full Text Available Abstract Background In some countries, "Big Events" like crises and transitions have been followed by large increases in drug use, drug injection and HIV/AIDS. Argentina experienced an economic crisis and political transition in 2001/2002 that affected how people use their time. This paper studies how time use changes between years 2001 and 2004, subsequent to these events, were associated with drug consumption in poor neighbourhoods of Greater Buenos Aires. Methods In 2003-2004, 68 current injecting drug users (IDUs and 235 young non-IDUs, aged 21-35, who lived in impoverished drug-impacted neighbourhoods in Greater Buenos Aires, were asked about time use then and in 2001. Data on weekly hours spent working or looking for work, doing housework/childcare, consuming drugs, being with friends, and hanging out in the neighbourhood, were studied in relation to time spent using drugs. Field observations and focus groups were also conducted. Results After 2001, among both IDUs and non-IDUs, mean weekly time spent working declined significantly (especially among IDUs; time spent looking for work increased, and time spent with friends and hanging out in the neighbourhood decreased. We found no increase in injecting or non-injecting drug consumption after 2001. Subjects most affected by the way the crises led to decreased work time and/or to increased time looking for work--and by the associated increase in time spent in one's neighbourhood--were most likely to increase their time using drugs. Conclusions Time use methods are useful to study changes in drug use and their relationships to every day life activities. In these previously-drug-impacted neighbourhoods, the Argentinean crisis did not lead to an increase in drug use, which somewhat contradicts our initial expectations. Nevertheless, those for whom the crises led to decreased work time, increased time looking for work, and increased time spent in indoor or outdoor neighbourhood environments, were

  6. Computational procedure of optimal inventory model involving controllable backorder rate and variable lead time with defective units

    Science.gov (United States)

    Lee, Wen-Chuan; Wu, Jong-Wuu; Tsou, Hsin-Hui; Lei, Chia-Ling

    2012-10-01

    This article considers that the number of defective units in an arrival order is a binominal random variable. We derive a modified mixture inventory model with backorders and lost sales, in which the order quantity and lead time are decision variables. In our studies, we also assume that the backorder rate is dependent on the length of lead time through the amount of shortages and let the backorder rate be a control variable. In addition, we assume that the lead time demand follows a mixture of normal distributions, and then relax the assumption about the form of the mixture of distribution functions of the lead time demand and apply the minimax distribution free procedure to solve the problem. Furthermore, we develop an algorithm procedure to obtain the optimal ordering strategy for each case. Finally, three numerical examples are also given to illustrate the results.

  7. An Integrated Multiechelon Logistics Model with Uncertain Delivery Lead Time and Quality Unreliability

    Directory of Open Access Journals (Sweden)

    Ming-Feng Yang

    2016-01-01

    Full Text Available Nowadays, in order to achieve advantages in supply chain management, how to keep inventory in adequate level and how to enhance customer service level are two critical practices for decision makers. Generally, uncertain lead time and defective products have much to do with inventory and service level. Therefore, this study mainly aims at developing a multiechelon integrated just-in-time inventory model with uncertain lead time and imperfect quality to enhance the benefits of the logistics model. In addition, the Ant Colony Algorithm (ACA is established to determine the optimal solutions. Moreover, based on our proposed model and analysis, the ACA is more efficient than Particle Swarm Optimization (PSO and Lingo in SMEIJI model. An example is provided in this study to illustrate how production run and defective rate have an effect on system costs. Finally, the results of our research could provide some managerial insights which support decision makers in real-world operations.

  8. Note: Optimal base-stock policy for the inventory system with periodic review, backorders and sequential lead times

    DEFF Research Database (Denmark)

    Johansen, Søren Glud; Thorstenson, Anders

    We show that well-known textbook formulae for determining the optimal base stock of the inventory system with continuous review and constant lead time can easily be extended to the case with periodic review and stochastic, sequential lead times. The provided performance measures and conditions...

  9. Survival Analysis of Occipital Nerve Stimulator Leads Placed under Fluoroscopic Guidance with and without Ultrasonography.

    Science.gov (United States)

    Jones, James H; Brown, Alison; Moyse, Daniel; Qi, Wenjing; Roy, Lance

    2017-11-01

    Electrical stimulation of the greater occipital nerves is performed to treat pain secondary to chronic daily headaches and occipital neuralgia. The use of fluoroscopy alone to guide the surgical placement of electrodes near the greater occipital nerves disregards the impact of tissue planes on lead stability and stimulation efficacy. We hypothesized that occipital neurostimulator (ONS) leads placed with ultrasonography combined with fluoroscopy would demonstrate increased survival rates and times when compared to ONS leads placed with fluoroscopy alone. A 2-arm retrospective chart review. A single academic medical center. This retrospective chart review analyzed the procedure notes and demographic data of patients who underwent the permanent implant of an ONS lead between July 2012 and August 2015. Patient data included the diagnosis (reason for implant), smoking tobacco use, disability, and age. ONS lead data included the date of permanent implant, the imaging modality used during permanent implant (fluoroscopy with or without ultrasonography), and, if applicable, the date and reason for lead removal. A total of 21 patients (53 leads) were included for the review. Chi-squared tests, Fishers exact tests, 2-sample t-tests, and Wilcoxon rank-sum tests were used to compare fluoroscopy against combined fluoroscopy and ultrasonography as implant methods with respect to patient demographics. These tests were also used to evaluate the primary aim of this study, which was to compare the survival rates and times of ONS leads placed with combined ultrasonography and fluoroscopy versus those placed with fluoroscopy alone. Survival analysis was used to assess the effect of implant method, adjusted for patient demographics (age, smoking tobacco use, and disability), on the risk of lead explant. Data from 21 patients were collected, including a total of 53 ONS leads. There was no statistically significant difference in the lead survival rate or time, disability, or patient age

  10. Biomarker responses of Peromyscus leucopus exposed to lead and cadmium in the Southeast Missouri Lead Mining District.

    Science.gov (United States)

    Beyer, W Nelson; Casteel, Stan W; Friedrichs, Kristen R; Gramlich, Eric; Houseright, Ruth A; Nichols, John R; Karouna-Renier, Natalie K; Kim, Dae Young; Rangen, Kathleen L; Rattner, Barnett A; Schultz, Sandra L

    2018-01-29

    Biomarker responses and histopathological lesions have been documented in laboratory mammals exposed to elevated concentrations of lead and cadmium. The exposure of white-footed mice (Peromyscus leucopus) to these metals and the potential associated toxic effects were examined at three contaminated sites in the Southeast Missouri Lead Mining District and at a reference site in MO, USA. Mice from the contaminated sites showed evidence of oxidative stress and reduced activity of red blood cell δ-aminolevulinic acid dehydratase (ALAD). Histological examinations of the liver and kidney, cytologic examination of blood smears, and biomarkers of lipid peroxidation and DNA damage failed to show indications of toxic effects from lead. The biomagnification factor of cadmium (hepatic concentration/soil concentration) at a site with a strongly acid soil was 44 times the average of the biomagnification factors at two sites with slightly alkaline soils. The elevated concentrations of cadmium in the mice did not cause observable toxicity, but were associated with about a 50% decrease in expected tissue lead concentrations and greater ALAD activity compared to the activity at the reference site. Lead was associated with a decrease in concentrations of hepatic glutathione and thiols, whereas cadmium was associated with an increase. In addition, to support risk assessment efforts, we developed linear regression models relating both tissue lead dosages (based on a previously published a laboratory study) and tissue lead concentrations in Peromyscus to soil lead concentrations.

  11. Biomarker responses of Peromyscus leucopus exposed to lead and cadmium in the Southeast Missouri Lead Mining District

    Science.gov (United States)

    Beyer, W. Nelson; Casteel, Stan W.; Friedrichs, Kristen R.; Gramlich, Eric; Houseright, Ruth A.; Nichols, John W.; Karouna-Renier, Natalie; Kim, Dae Young; Rangen, Kathleen; Rattner, Barnett A.; Schultz, Sandra

    2018-01-01

    Biomarker responses and histopathological lesions have been documented in laboratory mammals exposed to elevated concentrations of lead and cadmium. The exposure of white-footed mice (Peromyscus leucopus) to these metals and the potential associated toxic effects were examined at three contaminated sites in the Southeast Missouri Lead Mining District and at a reference site in MO, USA. Mice from the contaminated sites showed evidence of oxidative stress and reduced activity of red blood cell δ-aminolevulinic acid dehydratase (ALAD). Histological examinations of the liver and kidney, cytologic examination of blood smears, and biomarkers of lipid peroxidation and DNA damage failed to show indications of toxic effects from lead. The biomagnification factor of cadmium (hepatic concentration/soil concentration) at a site with a strongly acid soil was 44 times the average of the biomagnification factors at two sites with slightly alkaline soils. The elevated concentrations of cadmium in the mice did not cause observable toxicity, but were associated with about a 50% decrease in expected tissue lead concentrations and greater ALAD activity compared to the activity at the reference site. Lead was associated with a decrease in concentrations of hepatic glutathione and thiols, whereas cadmium was associated with an increase. In addition, to support risk assessment efforts, we developed linear regression models relating both tissue lead dosages (based on a previously published a laboratory study) and tissue lead concentrations in Peromyscus to soil lead concentrations.

  12. Lead Time to Appointment and No-Show Rates for New and Follow-up Patients in an Ambulatory Clinic.

    Science.gov (United States)

    Drewek, Rupali; Mirea, Lucia; Adelson, P David

    High rates of no-shows in outpatient clinics are problematic for revenue and for quality of patient care. Longer lead time to appointment has variably been implicated as a risk factor for no-shows, but the evidence within pediatric clinics is inconclusive. The goal of this study was to estimate no-show rates and test for association between appointment lead time and no-show rates for new and follow-up patients. Analyses included 534 new and 1920 follow-up patients from pulmonology and gastroenterology clinics at a freestanding children's hospital. The overall rate of no-shows was lower for visits scheduled within 0 to 30 days compared with 30 days or more (23% compared with 47%, P < .0001). Patient type significantly modified the association of appointment lead time; the rate of no-shows was higher (30%) among new patients compared with (21%) follow-up patients with appointments scheduled within 30 days (P = .004). For appointments scheduled 30 or more days' lead time, no-show rates were statistically similar for new patients (46%) and follow-up patients (0.48%). Time to appointment is a risk factor associated with no-shows, and further study is needed to identify and implement effective approaches to reduce appointment lead time, especially for new patients in pediatric subspecialties.

  13. Lead concentrations in the bones of city and country doves

    Energy Technology Data Exchange (ETDEWEB)

    Siegfried, W.R.; Frost, P.G.H.; Redelinghuys, E.P.; van der Merwe, R.P.

    The lead content of bones of laughing doves Streptopelia senegalensis was assayed by means of atomic absorption spectrophotometry. A significant difference in the mean lead content was found between two groups of wild doves. The one group was taken in the city of Cape Town, and the other group 50 km away in rural farmland near Stellenbosch. The bones of the urban doves contained on average seven times more lead per unit weight of tissue than those of their rural con-specifics. Concentrations of lead in the bones of rural and urban doves are approximately 70% and 80% below those recorded for corresponding pigeon Columba livia populations in Pennsylvania, USA. These differences between urban and rural populations are believed to reflect the relatively greater degree of lead in the atmosphere of the urban environment, presumably as a result of motor car exhaust emissions. 2 references, 1 table.

  14. A Small Decrease in Rubisco Content by Individual Suppression of RBCS Genes Leads to Improvement of Photosynthesis and Greater Biomass Production in Rice Under Conditions of Elevated CO2.

    Science.gov (United States)

    Kanno, Keiichi; Suzuki, Yuji; Makino, Amane

    2017-03-01

    Rubisco limits photosynthesis at low CO2 concentrations ([CO2]), but does not limit it at elevated [CO2]. This means that the amount of Rubisco is excessive for photosynthesis at elevated [CO2]. Therefore, we examined whether a small decrease in Rubisco content by individual suppression of the RBCS multigene family leads to increases in photosynthesis and biomass production at elevated [CO2] in rice (Oryza sativa L.). Our previous studies indicated that the individual suppression of RBCS decreased Rubisco content in rice by 10-25%. Three lines of BC2F2 progeny were selected from transgenic plants with individual suppression of OsRBCS2, 3 and 5. Rubisco content in the selected lines was 71-90% that of wild-type plants. These three transgenic lines showed lower rates of CO2 assimilation at low [CO2] (28 Pa) but higher rates of CO2 assimilation at elevated [CO2] (120 Pa). Similarly, the biomass production and relative growth rate (RGR) of the two lines were also smaller at low [CO2] but greater than that of wild-type plants at elevated [CO2]. This greater RGR was caused by the higher net assimilation rate (NAR). When the nitrogen use efficiency (NUE) for the NAR was estimated by dividing the NAR by whole-plant leaf N content, the NUE for NAR at elevated [CO2] was higher in these two lines. Thus, a small decrease in Rubisco content leads to improvements of photosynthesis and greater biomass production in rice under conditions of elevated CO2. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  15. Job-Sharing at the Greater Victoria Public Library.

    Science.gov (United States)

    Miller, Don

    1978-01-01

    Describes the problems associated with the management of part-time library employees and some solutions afforded by a job sharing arrangement in use at the Greater Victoria Public Library. This is a voluntary work arrangement, changing formerly full-time positions into multiple part-time positions. (JVP)

  16. The Politics of Affirmation Theory: When Group-Affirmation Leads to Greater Ingroup Bias.

    Science.gov (United States)

    Ehrlich, Gaven A; Gramzow, Richard H

    2015-08-01

    It has been well established in the literature that affirming the individual self reduces the tendency to exhibit group-favoring biases. The limited research examining group-affirmation and bias, however, is inconclusive. We argue that group-affirmation can exacerbate group-serving biases in certain contexts, and in the current set of studies, we document this phenomenon directly. Unlike self-affirmation, group-affirmation led to greater ingroup-favoring evaluative judgments among political partisans (Experiment 1). This increase in evaluative bias following group-affirmation was moderated by political party identification and was not found among those who affirmed a non-political ingroup (Experiment 2). In addition, the mechanism underlying these findings is explored and interpreted within the theoretical frameworks of self-categorization theory and the multiple self-aspects model (Experiments 2 and 3). The broader implications of our findings for the understanding of social identity and affirmation theory are discussed. © 2015 by the Society for Personality and Social Psychology, Inc.

  17. Symmetric airfoil geometry effects on leading edge noise.

    Science.gov (United States)

    Gill, James; Zhang, X; Joseph, P

    2013-10-01

    Computational aeroacoustic methods are applied to the modeling of noise due to interactions between gusts and the leading edge of real symmetric airfoils. Single frequency harmonic gusts are interacted with various airfoil geometries at zero angle of attack. The effects of airfoil thickness and leading edge radius on noise are investigated systematically and independently for the first time, at higher frequencies than previously used in computational methods. Increases in both leading edge radius and thickness are found to reduce the predicted noise. This noise reduction effect becomes greater with increasing frequency and Mach number. The dominant noise reduction mechanism for airfoils with real geometry is found to be related to the leading edge stagnation region. It is shown that accurate leading edge noise predictions can be made when assuming an inviscid meanflow, but that it is not valid to assume a uniform meanflow. Analytic flat plate predictions are found to over-predict the noise due to a NACA 0002 airfoil by up to 3 dB at high frequencies. The accuracy of analytic flat plate solutions can be expected to decrease with increasing airfoil thickness, leading edge radius, gust frequency, and Mach number.

  18. A reengineering success story: process improvement in emergency department x-ray cycle time, leading to breakthrough performance in the ED ambulatory care (Fast Track) process.

    Science.gov (United States)

    Espinosa, J A; Treiber, P M; Kosnik, L

    1997-01-01

    This article describes the journey of a multidisciplinary reengineering team, which worked to reduce a critical, high-leverage process in an emergency department setting. The process selected was emergency department radiology services. This process was selected on a rational basis. The team knew tht 60 percent of our emergency department patients were truly ambulatory, and that most could be seen in a "fast track" process as part of our emergency department's core mission. However, we knew from customer satisfaction data, that patients would like to be "in and out" of emergency department Fast Track in less than an hour. Over half of our Fast Track patients require x-rays. For most, this was their sole reason for seeking emergency care. Our state, at the start of the project, included an average x-ray cycle time of over 60 minutes. The associated Fast-Track cycle time was over 90 minutes median. It was clear to the emergency department leadership, as well as to members of the Fast-Track management team, that a cycle time of 30 minutes or less for x-ray service was needed as a necessary condition to an hour or less Fast Track cycle time. It was also felt that a more rapid x-ray cycle time would allow for more rapid turn over of ED rooms, leading to a virtual greater capacity to the ED. It was hoped that this would lead to a reduction in the time from arrival to treatment by the emergency physician for all patients.

  19. Supply Chain Model with Stochastic Lead Time, Trade-Credit Financing, and Transportation Discounts

    Directory of Open Access Journals (Sweden)

    Sung Jun Kim

    2017-01-01

    Full Text Available This model extends a two-echelon supply chain model by considering the trade-credit policy, transportations discount to make a coordination mechanism between transportation discounts, trade-credit financing, number of shipments, quality improvement of products, and reduced setup cost in such a way that the total cost of the whole system can be reduced, where the supplier offers trade-credit-period to the buyer. For buyer, the backorder rate is considered as variable. There are two investments to reduce setup cost and to improve quality of products. The model assumes lead time-dependent backorder rate, where the lead time is stochastic in nature. By using the trade-credit policy, the model gives how the credit-period would be determined to achieve the win-win outcome. An iterative algorithm is designed to obtain the global optimum results. Numerical example and sensitivity analysis are given to illustrate the model.

  20. Skin toxicology of lead species evaluated by their permeability and proteomic profiles: a comparison of organic and inorganic lead.

    Science.gov (United States)

    Pan, Tai-Long; Wang, Pei-Wen; Al-Suwayeh, Saleh A; Chen, Chih-Chieh; Fang, Jia-You

    2010-08-01

    Lead compounds are known to cause cytotoxicity and genotoxicity. Lead absorption by the skin is an important route through which this metal enters the body. The purpose of this work was to evaluate the skin permeability and toxicological profiles of two lead species, lead acetate and lead nitrate. This study assessed lead-induced toxicity mechanisms by focusing on the histopathology, proteomics, cell growth, and cellular ATP. In vitro skin permeation assays showed that there was no significant difference of lead accumulation within and across the skin between the two lead species. The presence of simulated sweat reduced the skin uptake of lead. The skin deposition of lead acetate was greater than that of lead nitrate with in vivo topical application. On the other hand, lead nitrate produced greater changes in the skin's histology and proteomic profiles compared to lead acetate. Four protein spots which showed significant changes were identified and are discussed in this study. These included glucose-related protein precursor (GRP) 78, K14, alpha-actin, and Rho GDP-dissociation inhibitor 2 (RhoGDI2). These proteins are respectively associated with oxidative stress, apoptosis, wound healing, and proliferation. Lead presented a biphasic pattern on cell growth and intracellular ATP content, with a stimulating effect at low concentrations and an inhibitory effect on cell proliferation at higher concentrations. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

  1. Scheduling rules to achieve lead-time targets in outpatient appointment systems

    OpenAIRE

    Sivakumar, Appa Iyer; Nguyen, Thu Ba Thi; Graves, Stephen C

    2015-01-01

    This paper considers how to schedule appointments for outpatients, for a clinic that is subject to appointment lead-time targets for both new and returning patients. We develop heuristic rules, which are the exact and relaxed appointment scheduling rules, to schedule each new patient appointment (only) in light of uncertainty about future arrivals. The scheduling rules entail two decisions. First, the rules need to determine whether or not a patient's request can be accepted; then, if the req...

  2. Safety stock or safety lead time : coping with unreliability in demand and supply

    NARCIS (Netherlands)

    van Kampen, T.J.; van Donk, D.P.; van der Zee, D.J.

    2010-01-01

    Safety stock and safety lead time are common measures used to cope with uncertainties in demand and supply. Typically, these uncertainties are studied in isolated instances, ignoring settings with uncertainties both in demand and in supply. The current literature largely neglects case study based

  3. Effect of exposure to greater active videogame variety on time spent in moderate- to vigorous-intensity physical activity.

    Science.gov (United States)

    Raynor, Hollie A; Cardoso, Chelsi; Bond, Dale S

    2016-07-01

    This investigation examined whether exposure to greater active videogame variety increases moderate- to vigorous-intensity physical activity (MVPA). Twenty-three participants (age=22.7±4.2yrs; body mass index=23.5±3.0kg/m(2); self-reported MVPA=298.7±116.7min/wk; 62.2% female; 73.9% Caucasian) participated in VARIETY (4 different active videogames during 4, 15-min bouts) and NON-VARIETY (only 1 active videogame during 4, 15-min bouts) counterbalanced sessions. VARIETY provided a different active videogame in each bout. NON-VARIETY provided participants their most highly liked active videogame in each bout. The Sensewear Mini Armband objectively assessed MVPA. For MVPA minutes, a session×bout (p<0.05) interaction occurred. In NON-VARIETY, bouts 2, 3, and 4 had significantly (p<0.05) fewer minutes than bout 1, with no decrease occurring in VARIETY. In bout 4, VARIETY had significantly (p<0.05) more minutes than NON-VARIETY. A main effect of session (p<0.05) occurred for MVPA minutes and energy expenditure, with VARIETY achieving greater amounts (31.8±14.3min vs. 27.6±16.9min; 186.1±96.8kcal vs. 171.2±102.8kcal). Exposure to greater activity variety within a session increased MVPA. Future research should examine exposure to a variety of activities over a longer time frame with participants of differing lifestyles in free-living environments. Copyright © 2016. Published by Elsevier Inc.

  4. Lead transfer in maternal milk, and the absorption, retention, distribution and excretion of lead in suckling mice

    Energy Technology Data Exchange (ETDEWEB)

    Keller, Charles Arthur [Univ. of Rochester, NY (United States). Dept. of Radiation Biology and Biophysics

    1980-01-01

    Suckling mice were found to absorb and retain a greater fraction of an oral lead dose than did adult mice. Pinocytotic activity and lead uptake (in vivo) were found to be greatest in the distal small intestinal tissue. Cortisone pretreatment results in precocious cessation of pinocytotic activity in the intestine of suckling mice. Cortisone pretreatment of adult mice had no effect on whole body lead retention or intestinal tissue content of lead following an oral dose. The data indicate that the distal small intestine is the site of active pinocytosis of lead, and that pinocytosis is the major mechanism involved in lead absorption in suckling mice. Developmental differences were also observed in the percentage of lead retained in the whole body. Both groups exhibited dose-independent lead retention, indicating a first-order absorption process for each age group. Lead distribution and elimination from organs also differed between suckling and adult mice. Developmental differences were observed in organ lead concentration for kidneys and brain following oral doses. Relative distribution of lead to the brains of suckling mice were greater than to adult brains. Whole body and bone lead elimination rates were reduced in suckling compared to adult mice. Brain lead elimination rates did not differ in suckling and adult mice. A lactating mouse model was developed to study lead transfer to suckling offspring. Lead was transferred in milk to suckling offspring from mothers which had previously ingested lead in the drinking water. Relative lead transfer to suckled offspring during lactation greatly exceeded transfer to fetuses during gestation. Lactation resulted in an increased rate of maternal lead elimination. Lead concentration in milk exceeded plasma concentration by a factor of approximately 25. (ERB)

  5. Production planning of a perishable product with lead time and non-stationary demand

    NARCIS (Netherlands)

    Pauls-Worm, K.G.J.; Haijema, R.; Hendrix, E.M.T.; Rossi, R.; Vorst, van der J.G.A.J.

    2012-01-01

    We study a production planning problem for a perishable product with a fixed lifetime, under a service-level constraint. The product has a non-stationary stochastic demand. Food supply chains of fresh products like cheese and several crop products, are characterised by long lead times due to

  6. The Protean Toxicities of Lead: New Chapters in a Familiar Story

    Directory of Open Access Journals (Sweden)

    David C. Bellinger

    2011-06-01

    Full Text Available Many times in the history of lead toxicology the view that “the problem” has been solved and is no longer a major health concern has prevailed, only to have further research demonstrate the prematurity of this judgment. In the last decade, an extraordinary amount of new research on lead has illustrated, all too clearly, that “the problem” has not disappeared, and that, in fact, it has dimensions never before considered. Recent risk assessments have concluded that research has yet to identify a threshold level below which lead can be considered “safe.” Although children’s intelligence has traditionally been considered to be the most sensitive endpoint, and used as the basis for risk assessment and standard setting, increased lead exposure has been associated with a wide variety of other morbidities both in children and adults, in some cases at biomarker levels comparable to those associated with IQ deficits in children. In adults, these endpoints include all-cause mortality and dysfunctions in the renal, cardiovascular, reproductive, central nervous systems. In children, IQ deficits are observed at blood lead levels well below 10 μg/dL, and the dose-effect relationship appears to be supra-linear. Other health endpoints associated with greater early-life lead exposure in children include ADHD, conduct disorder, aggression and delinquency, impaired dental health, and delayed sexual maturation. Studies employing neuroimaging modalities such as volumetric, diffusion tensor, and functional MRI are providing insights into the neural bases of the cognitive impairments associated with greater lead exposure.

  7. Comparison of lead levels in human permanent teeth from Strasbourg, Mexico City, and rural zones of Alsace

    International Nuclear Information System (INIS)

    Frank, R.M.; Sargentini-Maier, M.L.; Turlot, J.C.; Leroy, M.J.

    1990-01-01

    A comparative study of the mean lead concentrations in enamel and dentin of human premolars and permanent molars was conducted by means of a systematic sampling procedure with energy-dispersive x-ray fluorescence analysis. In a first series of analyses, no significant statistical differences in mean lead concentrations at various levels of enamel and dentin were noted between young patients of Strasbourg and those of small villages of Alsace, nor between elderly patients living in these two locations, despite the fact that motor traffic was significantly lower in the rural zones. However, in both locations, a significantly higher concentration of lead was observed in enamel and dentin in relation to age. In a second series of analyses, the mean lead concentrations of both dental hard tissues of premolars and permanent molars of young individuals from Strasbourg, rural Alsace, and Mexico City were compared. Significantly higher mean lead concentrations were found in enamel and dentin samples from Mexico City. This was most evident for inner coronal dentin (5.7 and 6.1 times greater than in teeth of Strasbourg and rural zones of Alsace, respectively) and for pulpal root dentin (6.9 and 8.9 times greater than in teeth of Strasbourg and rural zones of Alsace). It is proposed that the higher lead concentrations are related to the higher lead content of motor gasoline and to more intense traffic conditions. The dental hard tissues appear to be of value for the study of environmental lead pollution

  8. Integration of capacity, pricing, and lead-time decisions in a decentralized supply chain

    NARCIS (Netherlands)

    Zhu, Stuart X.

    We consider a decentralized supply chain consisting of a supplier and a retailer facing price- and lead-time-sensitive demand. The decision process is modelled by a Stackelberg game where the supplier, as a leader, determines the capacity and the wholesale price, and the retailer, as a follower,

  9. Safe leads and lead changes in competitive team sports

    Science.gov (United States)

    Clauset, A.; Kogan, M.; Redner, S.

    2015-06-01

    We investigate the time evolution of lead changes within individual games of competitive team sports. Exploiting ideas from the theory of random walks, the number of lead changes within a single game follows a Gaussian distribution. We show that the probability that the last lead change and the time of the largest lead size are governed by the same arcsine law, a bimodal distribution that diverges at the start and at the end of the game. We also determine the probability that a given lead is "safe" as a function of its size L and game time t . Our predictions generally agree with comprehensive data on more than 1.25 million scoring events in roughly 40 000 games across four professional or semiprofessional team sports, and are more accurate than popular heuristics currently used in sports analytics.

  10. A technology for production of a ''Cureless'' paste containing a high concentration of tetrabasic lead sulfate and a low concentration of free lead

    Energy Technology Data Exchange (ETDEWEB)

    Boden, David P.; Loosemore, Daniel [Hammond Lead Products, Division of Hammond Group Inc., 6544 Osborn Avenue, Hammond, IN 46320 (United States)

    2007-05-25

    The conventional paste used to produce plates for lead-acid batteries comprises a mixture of leady oxide, water and sulfuric acid. Fibre and other additives, such as expander in negative plates, are added to improve paste properties and battery performance. Following pasting of the plates, they have to be cured to provide the correct chemical composition and crystal morphology, and to oxidize any residual free lead metal to lead monoxide. The desired result of the curing process is a positive plate with a high concentration of uniformly sized tetrabasic lead sulfate (4BS) crystals and with both positive and negative plates having a low concentration of free lead. Curing is a time-consuming and expensive process, which requires large numbers of chambers capable of being heated to 85 C and containing an atmosphere with a relative humidity greater than 95%. This process adds significant cost to the battery. (author)

  11. Hydrogen extraction from liquid lithium-lead alloy by gas-liquid contact method

    International Nuclear Information System (INIS)

    Xie Bo; Weng Kuiping; Hou Jianping; Yang Guangling; Zeng Jun

    2013-01-01

    Hydrogen extraction experiment from liquid lithium-lead alloy by gas-liquid contact method has been carried out in own liquid lithium-lead bubbler (LLLB). Experimental results show that, He is more suitable than Ar as carrier gas in the filler tower. The higher temperature the tower is, the greater hydrogen content the tower exports. Influence of carrier gas flow rate on the hydrogen content in the export is jagged, no obvious rule. Although the difference between experimental results and literature data, but it is feasible that hydrogen isotopes extraction experiment from liquid lithium-lead by gas-liquid contact method, and the higher extraction efficiency increases with the growth of the residence time of the alloy in tower. (authors)

  12. Extending flood forecasting lead time in a large watershed by coupling WRF QPF with a distributed hydrological model

    Science.gov (United States)

    Li, Ji; Chen, Yangbo; Wang, Huanyu; Qin, Jianming; Li, Jie; Chiao, Sen

    2017-03-01

    Long lead time flood forecasting is very important for large watershed flood mitigation as it provides more time for flood warning and emergency responses. The latest numerical weather forecast model could provide 1-15-day quantitative precipitation forecasting products in grid format, and by coupling this product with a distributed hydrological model could produce long lead time watershed flood forecasting products. This paper studied the feasibility of coupling the Liuxihe model with the Weather Research and Forecasting quantitative precipitation forecast (WRF QPF) for large watershed flood forecasting in southern China. The QPF of WRF products has three lead times, including 24, 48 and 72 h, with the grid resolution being 20 km  × 20 km. The Liuxihe model is set up with freely downloaded terrain property; the model parameters were previously optimized with rain gauge observed precipitation, and re-optimized with the WRF QPF. Results show that the WRF QPF has bias with the rain gauge precipitation, and a post-processing method is proposed to post-process the WRF QPF products, which improves the flood forecasting capability. With model parameter re-optimization, the model's performance improves also. This suggests that the model parameters be optimized with QPF, not the rain gauge precipitation. With the increasing of lead time, the accuracy of the WRF QPF decreases, as does the flood forecasting capability. Flood forecasting products produced by coupling the Liuxihe model with the WRF QPF provide a good reference for large watershed flood warning due to its long lead time and rational results.

  13. Effect on blood lead of airborne lead particles characterized by size.

    Science.gov (United States)

    Park, Dong-Uk; Paik, Nam-Won

    2002-03-01

    Worker exposure to airborne lead particles was evaluated for a total of 117 workers in 12 work-places of four different industrial types in Korea. The particle sizes were measured using 8-stage cascade impactors worn by the workers. Mass median aerodynamic diameters (MMAD) were determined by type of industry and percentage of lead particles as a fraction of airborne lead (PbA) concentration was determined by particle size. Blood lead (PbB) levels of workers who matched airborne lead samples were also examined. A Scheffé's pairwise comparison test showed that MMAD and the fractions of each of respirable particles and lead particles lead particles lead particles (r = 0.82) than that between concentrations of small particles and PbA (r = 0.61). A simple linear regression indicated that PbB correlated better with respirable lead concentration (r2 = 0.35, P = 0.0001) than with PbA concentration and had a higher slope coefficient. Controlling for respirable lead concentration reduced the partial correlation coefficient between PbA concentration and PbB level from 0.56 to 0.20 (P = 0.053). The results indicate that the contribution of respirable lead particles to lead absorption would be greater than that of PbA. This study concludes that the measurement of PbA only may not properly reflect a worker's exposure to lead particles with diverse characteristics. For the evaluation of a worker's exposure to various types of lead particles, it is recommended that respirable lead particles as well as PbA be measured.

  14. Matching times of leading and following suggest cooperation through direct reciprocity during V-formation flight in ibis.

    Science.gov (United States)

    Voelkl, Bernhard; Portugal, Steven J; Unsöld, Markus; Usherwood, James R; Wilson, Alan M; Fritz, Johannes

    2015-02-17

    One conspicuous feature of several larger bird species is their annual migration in V-shaped or echelon formation. When birds are flying in these formations, energy savings can be achieved by using the aerodynamic up-wash produced by the preceding bird. As the leading bird in a formation cannot profit from this up-wash, a social dilemma arises around the question of who is going to fly in front? To investigate how this dilemma is solved, we studied the flight behavior of a flock of juvenile Northern bald ibis (Geronticus eremita) during a human-guided autumn migration. We could show that the amount of time a bird is leading a formation is strongly correlated with the time it can itself profit from flying in the wake of another bird. On the dyadic level, birds match the time they spend in the wake of each other by frequent pairwise switches of the leading position. Taken together, these results suggest that bald ibis cooperate by directly taking turns in leading a formation. On the proximate level, we propose that it is mainly the high number of iterations and the immediacy of reciprocation opportunities that favor direct reciprocation. Finally, we found evidence that the animals' propensity to reciprocate in leading has a substantial influence on the size and cohesion of the flight formations.

  15. Half Double Methodology – Leading projects to impact in half the time with double the impact

    DEFF Research Database (Denmark)

    Ehlers, Michael; Svejvig, Per

    this presentation to learn about the three core elements of the half-double methodology so that you can lead your projects to double the impact in half the time. Objectives: Summarize the half-double methodology and core elements of impact, flow, and leadership; explain how PMI’s project management tools can......Despite developments in agile methodologies over the last 20 years, the potential for optimization in projects is still significant. Current research shows that there are methodologies that can be used to reduce lead time and increase value creation of projects by 30% or more. Join...

  16. Study on residual discharge time of lead-acid battery based on fitting method

    Science.gov (United States)

    Liu, Bing; Yu, Wangwang; Jin, Yueqiang; Wang, Shuying

    2017-05-01

    This paper use the method of fitting to discuss the data of C problem of mathematical modeling in 2016, the residual discharge time model of lead-acid battery with 20A,30A,…,100A constant current discharge is obtained, and the discharge time model of discharge under arbitrary constant current is presented. The mean relative error of the model is calculated to be about 3%, which shows that the model has high accuracy. This model can provide a basis for optimizing the adaptation of power system to the electrical motor vehicle.

  17. The M/M/1 queue with inventory, lost sale and general lead times

    DEFF Research Database (Denmark)

    Saffari, Mohammad; Asmussen, Søren; Haji, Rasoul

    We consider an M/M/1 queueing system with inventory under the (r,Q) policy and with lost sales, in which demands occur according to a Poisson process and service times are exponentially distributed. All arriving customers during stockout are lost. We derive the stationary distributions of the joint...... queue length (number of customers in the system) and on-hand inventory when lead times are random variables and can take various distributions. The derived stationary distributions are used to formulate long-run average performance measures and cost functions in some numerical examples....

  18. The effect of lead concentration on the corrosion susceptibility of 2 1/4Cr-1Mo steel in a lead-lithium liquid

    International Nuclear Information System (INIS)

    Wilkinson, B.D.; Edwards, G.R.; Hoffman, N.J.

    1982-01-01

    The intergranular penetration of 21/4Cr-1Mo steel by lead-lithium liquids containing 0, 17.6, and 53 w/o lead has been investigated at temperatures from 300 0 C to 600 0 C for times up to 1000 hours. Limited tests using a 99.3 w/o lead-lithium liquid were also conducted. Tempering was found to remove the susceptibility of as-quenched 21/4Cr-1Mo steel to penetration at 500 0 C by lead-lithium liquids containing up to 53 w/o lead. Penetration by the 99.3 w/o lead-lithium liquid in 1000 hours at 500 0 C was found to be negligible even when the steel was in the as-quenched condition. An Arrhenius analysis yielded the same low initial activation energy (approx. equal to25 kJ/mole) for liquids containing 0, 17.6, and 53 w/o lead. The initial penetration rate for lead-free lithium was significantly greater than that for the lead-bearing liquids, a factor thought to be related to the effect of lead on the wettability of the liquid. The same secondary activation energy (approx. equal to120 kJ/mole) was also found for the three liquids. Furthermore, the secondary penetration rate was found to be insensitive to lead content. Anomalous behavior at 500 0 C, observed in this study as well as in previous studies, is discussed, and a hypothetical explanation for the behavior is presented. (orig.)

  19. Decreasing food fussiness in children with obesity leads to greater weight loss in family-based treatment.

    Science.gov (United States)

    Hayes, Jacqueline F; Altman, Myra; Kolko, Rachel P; Balantekin, Katherine N; Holland, Jodi Cahill; Stein, Richard I; Saelens, Brian E; Welch, R Robinson; Perri, Michael G; Schechtman, Kenneth B; Epstein, Leonard H; Wilfley, Denise E

    2016-10-01

    Food fussiness (FF), or the frequent rejection of both familiar and unfamiliar foods, is common among children and, given its link to poor diet quality, may contribute to the onset and/or maintenance of childhood obesity. This study examined child FF in association with anthropometric variables and diet in children with overweight/obesity participating in family-based behavioral weight loss treatment (FBT). Change in FF was assessed in relation to FBT outcome, including whether change in diet quality mediated the relation between change in FF and change in child weight. Child (N = 170; age = 9.41 ± 1.23) height and weight were measured, and parents completed FF questionnaires and three 24-h recalls of child diet at baseline and post-treatment. Healthy Eating Index-2005 scores were calculated. At baseline, child FF was related to lower vegetable intake. Average child FF decreased from start to end of FBT. Greater decreases in FF were associated with greater reductions in child body mass index and improved overall diet quality. Overall, diet quality change through FBT mediated the relation between child FF change and child body mass index change. Children with high FF can benefit from FBT, and addressing FF may be important in childhood obesity treatment to maximize weight outcomes. © 2016 The Obesity Society.

  20. Time-varying extreme value dependence with application to leading European stock markets

    KAUST Repository

    Castro-Camilo, Daniela; de Carvalho, Miguel; Wadsworth, Jennifer

    2018-01-01

    Extremal dependence between international stock markets is of particular interest in today’s global financial landscape. However, previous studies have shown this dependence is not necessarily stationary over time. We concern ourselves with modeling extreme value dependence when that dependence is changing over time, or other suitable covariate. Working within a framework of asymptotic dependence, we introduce a regression model for the angular density of a bivariate extreme value distribution that allows us to assess how extremal dependence evolves over a covariate. We apply the proposed model to assess the dynamics governing extremal dependence of some leading European stock markets over the last three decades, and find evidence of an increase in extremal dependence over recent years.

  1. Time-varying extreme value dependence with application to leading European stock markets

    KAUST Repository

    Castro-Camilo, Daniela

    2018-03-09

    Extremal dependence between international stock markets is of particular interest in today’s global financial landscape. However, previous studies have shown this dependence is not necessarily stationary over time. We concern ourselves with modeling extreme value dependence when that dependence is changing over time, or other suitable covariate. Working within a framework of asymptotic dependence, we introduce a regression model for the angular density of a bivariate extreme value distribution that allows us to assess how extremal dependence evolves over a covariate. We apply the proposed model to assess the dynamics governing extremal dependence of some leading European stock markets over the last three decades, and find evidence of an increase in extremal dependence over recent years.

  2. Soil is an important pathway of human lead exposure.

    OpenAIRE

    Mielke, H W; Reagan, P L

    1998-01-01

    This review shows the equal or greater importance of leaded gasoline-contaminated dust compared to lead-based paint to the child lead problem, and that soil lead, resulting from leaded gasoline and pulverized lead-based paint, is at least or more important than lead-based paint (intact and not pulverized) as a pathway of human lead exposure. Because lead-based paint is a high-dose source, the biologically relevant dosage is similar to lead in soil. Both lead-based paint and soil lead are asso...

  3. SureCure{sup (R)}-A new material to reduces curing time and improve curing reproducibility of lead-acid batteries

    Energy Technology Data Exchange (ETDEWEB)

    Boden, David P.; Loosemore, Daniel V.; Botts, G. Dean [Hammond Lead Products Division, Hammond Group Inc., 2323 165th Street, Hammond, IN 46320 (United States)

    2006-08-25

    This paper introduces a technology that considerably reduces the time to cure the positive plates of lead-acid batteries. In each of several full-scale trials at automotive and industrial battery manufacturers, the simple replacement of 1wt.% of leady oxide with finely-divided tetrabasic lead sulfate (SureCure(TM) by Hammond Group Inc.) is shown to accelerate significantly the conversion of tribasic lead sulfate (3BS) to tetrabasic lead sulfate (4BS) in the curing process while improving crystal structure and reproducibility. Shorter curing times result in reduced labour and energy costs, as well as reduced fixed (curing chambers and plant footprint) and working (plate inventory) capital investment. (author)

  4. All roads lead to Rome: the impact of multiple attainment means on motivation.

    Science.gov (United States)

    Huang, Szu-Chi; Zhang, Ying

    2013-02-01

    Individuals have different concerns before and after they become relatively certain about a goal's attainability; hence, we propose that the presence of alternative means of goal attainment will have a distinctive impact on motivation, depending on their stage of goal pursuit. In the initial stage of goal pursuit, people are concerned about whether the goal is attainable. The presence of multiple attainment means (vs. a single means) makes the goal seem more easily attainable and thus leads to greater motivation. Conversely, when people have made substantial progress on the goal and its attainment is relatively secured, they focus more on how they can race to the end and complete the pursuit. At these times, a single means (vs. multiple means) provides a more straightforward action plan and in turn leads to greater motivation. Two field studies and 3 lab experiments support this theorizing. (c) 2013 APA, all rights reserved.

  5. The effects of thiamin on lead metabolism: organ distribution of lead 203.

    Science.gov (United States)

    Kim, J S; Hamilton, D L; Blakley, B R; Rousseaux, C G

    1992-01-01

    The effect of thiamin on the organ distribution of lead was evaluated in CD-1 mice exposed intragastrically or intraperitoneally to a single dose of lead acetate (100 micrograms) containing 100 microCi lead 203. They were treated with either thiamin (25 or 50 mg/kg body weight), calcium ethylenediaminetetraacetic acid (CaEDTA) (50 mg/kg body weight), or combinations of thiamin and CaEDTA. The whole body retention and the organ distribution of lead 203 varied depending upon the route of lead administration, dose of thiamin and the specific treatment combination. Thiamin (25 or 50 mg/kg) treatment increased the whole body retention of both intragastric and intraperitoneal lead by approximately 10% in each instance. Calcium ethylenediaminetetraacetic acid, either alone or in combination with thiamin (50 mg/kg) reduced the whole body retention of lead by as much as 14% regardless of route of lead exposure. The relative retention of lead by the liver, kidney and spleen was greater in mice exposed to lead by the intragastric route. Regardless of route, CaEDTA in the combined treatment reduced the relative retention of lead in both the liver and kidney, whereas thiamin alone only reduced the retention of lead in the kidney. The results of this study indicate that thiamin in combination with CaEDTA alters the distribution and retention of lead in a manner which may have therapeutic application as it relates to chelation therapy. PMID:1423063

  6. High human exposure to lead through consumption of birds hunted with lead shot

    International Nuclear Information System (INIS)

    Johansen, P.; Asmund, G.; Riget, F.

    2004-01-01

    Lead shot contaminates the edible parts of birds so that tolerable human lead intake is exceeded. - We assess lead contamination of Greenland seabirds killed with lead shot having studied thick-billed murre and common eider, the two most important species in the diet. The lead concentration is very high in meat of eiders killed with lead shot (mean 6.1 μg/g-wet wt, 95% CL 2.1-12). This level is about 44 times higher than in drowned eiders and eight times higher than in shot murres. Analyzing whole breasts instead of sub-samples reveals about seven times higher lead levels in birds' meat. We conclude that in some cases the lead intake by Greenland bird eaters will largely exceed the FAO/WHO tolerable lead intake guideline and that lead shot is a more important source of lead in the diet than previously estimated

  7. Evaluating the Effect of Lead Time on Quality Service Delivery in the Banking Industry in Kumasi Metropolis of Ghana

    Directory of Open Access Journals (Sweden)

    Stephen Okyere

    2015-07-01

    Full Text Available Customers are becoming more attracted to quality service delivery and are being impatience and unsatisfied when they had to be delayed or wait for longer times before they are served.  Hence, Quality Service Delivery is of utmost importance to every service organisation especially financial industry. Most financial institutions focus attention on product innovation at the expense of lead time management which is a major factor in ensuring service quality and customer satisfaction. Consequently, this research looks at evaluating the effect of lead time on quality service delivery in the Banking Industry in Kumasi Metropolis of Ghana. The study relied on Primary data collected through questionnaires, observation and interview instruments, administered to staff and customers of some selected branches of a commercial bank in the study area. The data was analysed qualitatively. The researchers realised that despite the immense importance of lead time on quality service delivery, little attention is given to the concept. It was revealed that, customers were dissatisfied with the commercial bank’s services as a result of the unnecessary delays and queuing at the bank premises. The long lead time was found to be attributable to plant/system failure, skill gap on the part of employees, ATM underutilization and frequent breakdowns, among others. This has consequently resulted into long lead time, waiting, queuing and unnecessary delay at the banking hall. It is recommended that Tellers should be provided with electronic card readers for verification of customer’s data and processing to be faster.

  8. When good news leads to bad choices.

    Science.gov (United States)

    McDevitt, Margaret A; Dunn, Roger M; Spetch, Marcia L; Ludvig, Elliot A

    2016-01-01

    Pigeons and other animals sometimes deviate from optimal choice behavior when given informative signals for delayed outcomes. For example, when pigeons are given a choice between an alternative that always leads to food after a delay and an alternative that leads to food only half of the time after a delay, preference changes dramatically depending on whether the stimuli during the delays are correlated with (signal) the outcomes or not. With signaled outcomes, pigeons show a much greater preference for the suboptimal alternative than with unsignaled outcomes. Key variables and research findings related to this phenomenon are reviewed, including the effects of durations of the choice and delay periods, probability of reinforcement, and gaps in the signal. We interpret the available evidence as reflecting a preference induced by signals for good news in a context of uncertainty. Other explanations are briefly summarized and compared. © 2016 Society for the Experimental Analysis of Behavior.

  9. ADVANCEMENTS IN TIME-SPECTRA ANALYSIS METHODS FOR LEAD SLOWING-DOWN SPECTROSCOPY

    International Nuclear Information System (INIS)

    Smith, Leon E.; Anderson, Kevin K.; Gesh, Christopher J.; Shaver, Mark W.

    2010-01-01

    Direct measurement of Pu in spent nuclear fuel remains a key challenge for safeguarding nuclear fuel cycles of today and tomorrow. Lead slowing-down spectroscopy (LSDS) is an active nondestructive assay method that has the potential to provide independent, direct measurement of Pu and U isotopic mass with an uncertainty lower than the approximately 10 percent typical of today's confirmatory assay methods. Pacific Northwest National Laboratory's (PNNL) previous work to assess the viability of LSDS for the assay of pressurized water reactor (PWR) assemblies indicated that the method could provide direct assay of Pu-239 and U-235 (and possibly Pu-240 and Pu-241) with uncertainties less than a few percent, assuming suitably efficient instrumentation, an intense pulsed neutron source, and improvements in the time-spectra analysis methods used to extract isotopic information from a complex LSDS signal. This previous simulation-based evaluation used relatively simple PWR fuel assembly definitions (e.g. constant burnup across the assembly) and a constant initial enrichment and cooling time. The time-spectra analysis method was founded on a preliminary analytical model of self-shielding intended to correct for assay-signal nonlinearities introduced by attenuation of the interrogating neutron flux within the assembly.

  10. Cadmium and lead in tissues of Mallards (Anas platyrhynchos) and Wood Ducks (Aix sponsa) using the Illinois River (USA)

    International Nuclear Information System (INIS)

    Levengood, J.M.

    2003-01-01

    Tissue lead and cadmium concentrations were examined in two common, widely distributed species of duck, utilizing a major river system. - Cadmium and lead concentrations were determined in the tissues of Mallards and Wood Ducks collected from two waterfowl management areas along the Illinois River, USA, during the autumn and late winter of 1997-1998. Lead concentrations in livers of Mallards were lower than previously reported, and, along with those in a small sample of Wood Duck livers, were within background levels (<2.0 μg/g wet weight). Mean concentrations of cadmium in the kidneys of Wood Ducks utilizing the Illinois River were four times greater than in after-hatch-year Mallards, and 14 times greater than in hatch-year Mallards. Concentrations of cadmium in the kidneys of Wood Ducks were comparable with those of specimens dosed with cadmium or inhabiting contaminated areas in previous studies. Wood Ducks utilizing wetlands associated with the Illinois River, and presumably other portions of the lower Great Lakes region, may be chronically exposed to cadmium

  11. Development of small, fast reactor core designs using lead-based coolant

    International Nuclear Information System (INIS)

    Cahalan, J. E.; Hill, R. N.; Khalil, H. S.; Wade, D. C.

    1999-01-01

    A variety of small (100 MWe) fast reactor core designs are developed, these include compact configurations, long-lived (15-year fuel lifetime) cores, and derated, natural circulation designs. Trade studies are described which identify key core design issues for lead-based coolant systems. Performance parameters and reactivity feedback coefficients are compared for lead-bismuth eutectic (LBE) and sodium-cooled cores of consistent design. The results of these studies indicate that the superior neutron reflection capability of lead alloys reduces the enrichment and burnup swing compared to conventional sodium-cooled systems; however, the discharge fluence is significantly increased. The size requirement for long-lived systems is constrained by reactivity loss considerations, not fuel burnup or fluence limits. The derated lead-alloy cooled natural circulation cores require a core volume roughly eight times greater than conventional compact systems. In general, reactivity coefficients important for passive safety performance are less favorable for the larger, derated configurations

  12. Linking cases of illegal shootings of the endangered California condor using stable lead isotope analysis

    Energy Technology Data Exchange (ETDEWEB)

    Finkelstein, Myra E., E-mail: myraf@ucsc.edu [Microbiology and Environmental Toxicology Department, University of California, Santa Cruz, CA 95064 (United States); Kuspa, Zeka E. [Microbiology and Environmental Toxicology Department, University of California, Santa Cruz, CA 95064 (United States); Welch, Alacia [National Park Service, Pinnacles National Park, 5000 Highway 146, Paicines, CA 95043 (United States); Eng, Curtis; Clark, Michael [Los Angeles Zoo and Botanical Gardens, 5333 Zoo Drive, Los Angeles, CA 90027 (United States); Burnett, Joseph [Ventana Wildlife Society, 19045 Portola Dr. Ste. F-1, Salinas, CA 93908 (United States); Smith, Donald R. [Microbiology and Environmental Toxicology Department, University of California, Santa Cruz, CA 95064 (United States)

    2014-10-15

    Lead poisoning is preventing the recovery of the critically endangered California condor (Gymnogyps californianus) and lead isotope analyses have demonstrated that ingestion of spent lead ammunition is the principal source of lead poisoning in condors. Over an 8 month period in 2009, three lead-poisoned condors were independently presented with birdshot embedded in their tissues, evidencing they had been shot. No information connecting these illegal shooting events existed and the timing of the shooting(s) was unknown. Using lead concentration and stable lead isotope analyses of feathers, blood, and recovered birdshot, we observed that: i) lead isotope ratios of embedded shot from all three birds were measurably indistinguishable from each other, suggesting a common source; ii) lead exposure histories re-constructed from feather analysis suggested that the shooting(s) occurred within the same timeframe; and iii) two of the three condors were lead poisoned from a lead source isotopically indistinguishable from the embedded birdshot, implicating ingestion of this type of birdshot as the source of poisoning. One of the condors was subsequently lead poisoned the following year from ingestion of a lead buckshot (blood lead 556 µg/dL), illustrating that ingested shot possess a substantially greater lead poisoning risk compared to embedded shot retained in tissue (blood lead ∼20 µg/dL). To our knowledge, this is the first study to use lead isotopes as a tool to retrospectively link wildlife shooting events. - Highlights: • We conducted a case-based analysis of illegal shootings of California condors. • Blood and feather Pb isotopes were used to reconstruct the illegal shooting events. • Embedded birdshot from the three condors had the same Pb isotope ratios. • Feather and blood Pb isotopes indicated that the condors were shot in a common event. • Ingested shot causes substantially greater lead exposure compared to embedded shot.

  13. Lead diffusion in monazite

    International Nuclear Information System (INIS)

    Gardes, E.

    2006-06-01

    Proper knowledge of the diffusion rates of lead in monazite is necessary to understand the U-Th-Pb age anomalies of this mineral, which is one of the most used in geochronology after zircon. Diffusion experiments were performed in NdPO 4 monocrystals and in Nd 0.66 Ca 0.17 Th 0.17 PO 4 polycrystals from Nd 0.66 Pb 0.17 Th 0.17 PO 4 thin films to investigate Pb 2+ + Th 4+ ↔ 2 Nd 3+ and Pb 2+ ↔ Ca 2+ exchanges. Diffusion annealings were run between 1200 and 1500 Celsius degrees, at room pressure, for durations ranging from one hour to one month. The diffusion profiles were analysed using TEM (transmission electronic microscopy) and RBS (Rutherford backscattering spectroscopy). The diffusivities extracted for Pb 2+ + Th 4+ ↔ 2 Nd 3+ exchange follow an Arrhenius law with parameters E equals 509 ± 24 kJ mol -1 and log(D 0 (m 2 s -1 )) equals -3.41 ± 0.77. Preliminary data for Pb 2+ ↔ Ca 2+ exchange are in agreement with this result. The extrapolation of our data to crustal temperatures yields very slow diffusivities. For instance, the time necessary for a 50 μm grain to lose all of its lead at 800 Celsius degrees is greater than the age of the Earth. From these results and other evidence from the literature, we conclude that most of the perturbations in U-Th-Pb ages of monazite cannot be attributed to lead diffusion, but rather to interactions with fluids. (author)

  14. Puerarin exhibits greater distribution and longer retention time in neurons than astrocytes in a co-cultured system

    Directory of Open Access Journals (Sweden)

    Shu-Yong Wei

    2015-01-01

    Full Text Available The phytoestrogen puerarin has been shown to protect neurons and astrocytes in the brain, and is therefore an attractive drug in the treatment of Alzheimer′s disease, Parkinson′s disease and cerebral ischemia. Whether puerarin exhibits the same biological processes in neurons and astrocytes in vitro has rarely been reported. In this study, cortical neurons and astrocytes of newborn Sprague-Dawley rats were separated, identified and co-cultured in a system based on Transwell membranes. The retention time and distribution of puerarin in each cell type was detected by fluorescence spectrophotometry and fluorescence microscope. The concentration of puerarin in both co-cultured and separately cultured neurons was greater than that of astrocytes. Puerarin concentration reached a maximum 20 minutes after it was added. At 60 minutes after its addition, a scant amount of drug was detected in astrocytes; however in both separately cultured and co-cultured neurons, the concentration of puerarin achieved a stable level of about 12.8 ng/mL. The results indicate that puerarin had a higher concentration and longer retention time in neurons than that observed in astrocytes.

  15. Electromagnetic properties of thin film lead superconductors

    International Nuclear Information System (INIS)

    Moriyama, K.

    1978-01-01

    The dependence of critical film magnetic field H/sub cf/ on temperature, thickness, and surface texture of lead superconducting films was investigated, as well as the relationship between the applied magnetic field and the applied current at the critical field. Temperature and thickness dependence data were consistent with the predictions of London, of Ginzburg, and of Bardeen, Cooper, and Schreiffer. The values of H/sub cf/ of lead films deposited on a rough surface were consistently lower than for those on a smooth surface and so were not in agreement with any currently accepted theory. The degree of lowering of H/sub cf/ by a rough surface was greater in thin films than in thick films. The expected dependence of penetration depth lambda on thickness d was not observed, and the range of lambda was somewhat greater than expected. The range of coherence length was greater than predicted. The prediction for temperature dependence of critical current by Glover and Coffey was found to involve some oversimplification, and a suggested correction is supported by the data. For applied magnetic fields perpendicular to the applied current and parallel to the film surface, the relationship between the critical values of the magnetic field and the current was as predicted for lead films by Alphonse and Bergstein

  16. Biparental chloroplast inheritance leads to rescue from cytonuclear incompatibility.

    Science.gov (United States)

    Barnard-Kubow, Karen B; McCoy, Morgan A; Galloway, Laura F

    2017-02-01

    Although organelle inheritance is predominantly maternal across animals and plants, biparental chloroplast inheritance has arisen multiple times in the angiosperms. Biparental inheritance has the potential to impact the evolutionary dynamics of cytonuclear incompatibility, interactions between nuclear and organelle genomes that are proposed to be among the earliest types of genetic incompatibility to arise in speciation. We examine the interplay between biparental inheritance and cytonuclear incompatibility in Campanulastrum americanum, a plant species exhibiting both traits. We first determine patterns of chloroplast inheritance in genetically similar and divergent crosses, and then associate inheritance with hybrid survival across multiple generations. There is substantial biparental inheritance in C. americanum. The frequency of biparental inheritance is greater in divergent crosses and in the presence of cytonuclear incompatibility. Biparental inheritance helps to mitigate cytonuclear incompatibility, leading to increased fitness of F 1 hybrids and recovery in the F 2 generation. This study demonstrates the potential for biparental chloroplast inheritance to rescue cytonuclear compatibility, reducing cytonuclear incompatibility's contribution to reproductive isolation and potentially slowing speciation. The efficacy of rescue depended upon the strength of incompatibility, with a greater persistence of weak incompatibilities in later generations. These findings suggest that incompatible plastids may lead to selection for biparental inheritance. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  17. Generator exchange is associated with an increased rate of Sprint Fidelis lead failure.

    Science.gov (United States)

    Lovelock, Joshua D; Patel, Ayesha; Mengistu, Andenet; Hoskins, Michael; El-Chami, Mikhael; Lloyd, Michael S; Leon, Angel; DeLurgio, David; Langberg, Jonathan J

    2012-10-01

    The Medtronic Sprint Fidelis defibrillator lead is at an increased risk for failure and was recalled in October 2007. Approximately 268,000 leads were implanted, and more than 100,000 patients still have active Fidelis leads. A number of studies have examined the rate and clinical predictors of lead failure, but none has addressed the effect of an implantable cardioverter-defibrillator generator exchange on subsequent lead failure. Although the manufacturer asserts that "Sprint Fidelis performance after device change-out is similar to lead performance without device change-out," published data are lacking. To assess the effect of implantable cardioverter-defibrillator generator exchange on the rate of Fidelis lead failure. A chart review was conducted in patients who underwent implantation of a Fidelis lead. Patients with a functioning Fidelis lead at generator exchange were compared with controls with leads implanted for a comparable amount of time not undergoing ICD replacement. A total of 1366 patients received a Fidelis lead prior to the recall, of which 479 were still actively followed. Seventy-two patients with a functioning lead underwent generator exchange without lead replacement. Following generator replacement, 15 leads failed. Sixty percent of the Fidelis leads failed within 3 months. Generator exchange increased the rate of lead failure compared with matched controls (20.8% vs 2.54%; P exchange is associated with a higher than expected rate of Fidelis lead failure, often within 3 months. The risk-benefit ratio of Fidelis lead replacement at the time of generator exchange may be greater than appreciated. Copyright © 2012 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  18. The impact of product configurators on lead times in engineering-oriented companies

    DEFF Research Database (Denmark)

    Haug, Anders; Hvam, Lars; Mortensen, Niels Henrik

    2011-01-01

    This paper presents a study of how the use of product configurators affects business processes of engineering-oriented companies. A literature study shows that only a minor part of product configuration research deals with the effects of product configuration, and that the ones that do are mostly...... vague when reporting the effects of configurator projects. Only six cases were identified, which provide estimates of the actual size of lead time reduction achieved from product configurators. To broaden this knowledge, this paper presents the results of a study of 14 companies concerning the impact...

  19. Childhood lead poisoning from commercially manufactured French ceramic dinnerware--New York City, 2003.

    Science.gov (United States)

    2004-07-09

    Lead poisoning adversely affects children worldwide. During 1999-2000, an estimated 434,000 children aged 1-5 years in the United States had elevated blood lead levels (BLLs) >/=10 microg/dL. Glazes found on ceramics, earthenware, bone china, and porcelain often contain lead and are a potential source of lead exposure. Children are especially vulnerable to the neurotoxic effects of lead. Exposures to lead in early childhood can have adverse effects on the developing nervous system, resulting in decreased intelligence and changes in behavior. In addition, certain behaviors (e.g., thumb sucking) place children at greater risk for exposure to lead. In 2003, the New York City Department of Health and Mental Hygiene's Lead Poisoning Prevention Program (LPPP), and the Mount Sinai Pediatric Environmental Health Specialty Unit (PEHSU) investigated a case of lead poisoning in a boy aged 20 months. This report summarizes that case investigation, which identified ceramic dinnerware imported from France as the source of lead exposure. This case underscores the susceptibility of children to a toxic exposure associated with 1) the high proportion of time spent in the home and 2) dietary habits that promote exposure to lead leached from ceramic ware.

  20. Route around real time

    International Nuclear Information System (INIS)

    Terrier, Francois

    1996-01-01

    The greater and greater autonomy and complexity asked to the control and command systems lead to work on introducing techniques such as Artificial Intelligence or concurrent object programming in industrial applications. However, while the critical feature of these systems impose to control the dynamics of the proposed solutions, their complexity often imposes a high adaptability to a partially modelled environment. The studies presented start from low level control and command systems to more complex applications at higher levels, such as 'supervision systems'. Techniques such as temporal reasoning and uncertainty management are proposed for the first studies, while the second are tackled with programming techniques based on the real time object paradigm. The outcomes of this itinerary crystallize on the ACCORD project which targets to manage - on the whole life cycle of a real time application - these two problematics, sometimes antagonistic: control of the dynamics and adaptivity. (author) [fr

  1. The relationship between back pain and lead apron use in radiologists

    Energy Technology Data Exchange (ETDEWEB)

    Moore, B.; vanSonnenberg, E.; Casola, G.; Novelline, R.A. (Department of Radiology, University of California, San Diego (Unites States))

    1992-01-01

    Anecdotal experience has suggested that back pain in radiologists may result from extensive wearing of lead aprons. To investigate this possibility, the authors sent questionnaires to 688 radiologists in various subspecialties whose use of lead aprons varied from none to moderate to extensive. The questionnaire included both objective items that quantitated apron use and back pain and subjective items that asked, for example, if the respondent believed that lead aprons were responsible for his or her back pain. They received 236 responses (34% response rate). Objective data from those radiologists who had experienced no back pain before wearing a lead apron (179 radiologists, 26% of those surveyed) were tabulated; respondents were grouped according to age, time spent wearing a lead apron, and degree of back pain. Odds ratios were calculated. Answers to subjective questions for all respondents were tabulated. Back pain was reported by 52% of those who estimated their lead apron use at greater than or equal to 10 hr per week, the mean response, as opposed to 46% of those who wore lead aprons fewer than 10 hr a week. These and related results were not statistically significant. Our study does not prove that wearing a lead apron is a significant risk factor for the development of back pain.

  2. The relationship between back pain and lead apron use in radiologists

    International Nuclear Information System (INIS)

    Moore, B.; vanSonnenberg, E.; Casola, G.; Novelline, R.A.

    1992-01-01

    Anecdotal experience has suggested that back pain in radiologists may result from extensive wearing of lead aprons. To investigate this possibility, the authors sent questionnaires to 688 radiologists in various subspecialties whose use of lead aprons varied from none to moderate to extensive. The questionnaire included both objective items that quantitated apron use and back pain and subjective items that asked, for example, if the respondent believed that lead aprons were responsible for his or her back pain. They received 236 responses (34% response rate). Objective data from those radiologists who had experienced no back pain before wearing a lead apron (179 radiologists, 26% of those surveyed) were tabulated; respondents were grouped according to age, time spent wearing a lead apron, and degree of back pain. Odds ratios were calculated. Answers to subjective questions for all respondents were tabulated. Back pain was reported by 52% of those who estimated their lead apron use at greater than or equal to 10 hr per week, the mean response, as opposed to 46% of those who wore lead aprons fewer than 10 hr a week. These and related results were not statistically significant. Our study does not prove that wearing a lead apron is a significant risk factor for the development of back pain

  3. Variation in pre-treatment count lead time and its effect on baseline estimates of cage-level sea lice abundance.

    Science.gov (United States)

    Gautam, R; Boerlage, A S; Vanderstichel, R; Revie, C W; Hammell, K L

    2016-11-01

    Treatment efficacy studies typically use pre-treatment sea lice abundance as the baseline. However, the pre-treatment counting window often varies from the day of treatment to several days before treatment. We assessed the effect of lead time on baseline estimates, using historical data (2010-14) from a sea lice data management programme (Fish-iTrends). Data were aggregated at the cage level for three life stages: (i) chalimus, (ii) pre-adult and adult male and (iii) adult female. Sea lice counts were log-transformed, and mean counts by lead time relative to treatment day were computed and compared separately for each life stage, using linear mixed models. There were 1,658 observations (treatment events) from 56 sites in 5 Bay Management Areas. Our study showed that lead time had a significant effect on the estimated sea lice abundance, which was moderated by season. During the late summer and autumn periods, counting on the day of treatment gave significantly higher values than other days and would be a more appropriate baseline estimate, while during spring and early summer abundance estimates were comparable among counts within 5 days of treatment. A season-based lead time window may be most appropriate when estimating baseline sea lice levels. © 2016 John Wiley & Sons Ltd.

  4. Blood Lead Levels and Risk Factors for Lead Exposure in a Pediatric Population in Ho Chi Minh City, Vietnam

    Directory of Open Access Journals (Sweden)

    Deborah Havens

    2018-01-01

    Full Text Available Although lead recycling activities are a known risk factor for elevated blood levels in South East Asia, little is known regarding the prevalence of and risk factors for elevated blood lead levels (BLL among the general pediatric population in Vietnam. This study is a cross-sectional evaluation of 311 children from Children’s Hospital #2 in Ho Chi Minh City, Vietnam. Capillary blood lead testing was performed using the LeadCare II. Mean BLLs were 4.97 μg/dL (Standard Deviation (SD 5.50, with 7% of the participants having levels greater than 10 μg/dL. Living in Bing Duong province (OR 2.7, 95% CI 1.4–5.6.1 or the Dong Nai province (OR 2.3, 95% CI 1.0–5.1 and having an age greater than 12 months (OR 6.0, 95% CI 3.1–11.8 were associated with higher BLLs. The prevalence of elevated BLLs in Vietnam is consistent with other SE Asian countries. Mean BLLs in Ho Chi Minh City are markedly less than those seen in a separate study of children living near lead recycling activities. Additional evaluation is necessary to better detail potential risk factors if screening is to be implemented within Vietnam.

  5. L-line x-ray fluorescence of cortical bone lead compared with the CaNa2EDTA test in lead-toxic children: public health implications

    International Nuclear Information System (INIS)

    Rosen, J.F.; Markowitz, M.E.; Bijur, P.E.; Jenks, S.T.; Wielopolski, L.; Kalef-Ezra, J.A.; Slatkin, D.N.

    1989-01-01

    Mild to moderate lead toxicity (blood lead, 25-55 micrograms/dl) is a preventable pediatric illness affecting several million preschool children (lead-toxic children) in the United States. In-hospital lead-chelation treatment is predicated upon a positive CaNa 2 EDTA test, which is difficult to perform and impractical in large populations. After the development of an L-line x-ray fluorescence technique (LXRF) that measures cortical bone lead content safely, rapidly, and noninvasively, this study was initiated in lead-toxic children to compare LXRF with the CaNa 2 EDTA test. Moreover, LXRF provided the opportunity to quantify bone lead content. From blood lead and LXRF alone, 90% of lead-toxic children were correctly classified as being CaNa 2 EDTA-positive or -negative. In 76% of 59 lead-toxic children, bone lead values measured by LXRF were equal to or greater than those measured in normal and industrially exposed adults. These results indicate that LXRF may be capable of replacing the CaNa 2 EDTA test. When considered with the known neurotoxic effects on children of low levels of exposure to lead, these results also suggest that either an excessively narrow margin of safety or insufficient safety is provided by present U.S. guidelines, which classify an elevated blood lead concentration as 25 micrograms/dl or greater

  6. Radiography of Co-60 in the lead cube castings

    International Nuclear Information System (INIS)

    Djoli Soembogo; Harun Al Rasyid R; Namad Sianta

    2016-01-01

    Radiography Co-60 on Carbon steel or Stainless steel has been widely applied, but for metal Lead has not yet been applied and has not yet widely known. Lead has a greater density than Carbon steel or Stainless steel and could muffle gamma radiation so it takes a longer exposure time. The result of its film radiography are also not as good as compared to radiography applications on carbon steel or Stainless steel. The study also applied digital radiography using isotope Co-60 sources and used Epson V700 scanner positive film for digitization results of conventional radiographic films. These radiographs using film AGFA D7 to get the contrast medium, medium sensitivity and good image quality. The purpose of radiography Co-60 on the cube castings Lead is to find indications of defective castings cube Lead and digitizing the results using conventional radiographic film with a positive film media scanner to process the data transfer and storage of digital data. Radiographic testing has been carried out using the isotope Co-60 on metal castings Lead with a single thickness of a single shadow method using positive film scanner media and isotope Co-60 with disabilities observation parameter Lead metal castings on radiographic film. Co-60 radiation time exposure is 3,500 hours for the thickness of the metal cube castings Lead 100 mm with the activity of 29 Ci and perpendicular SFD of 840 mm. Radiographic testing on metal cube castings Lead by the method of a single thickness of single image defects produce a parameter indicative for a cube of metal castings Lead of porosity level 2. The density mean of radiographic film was 2.051 and 2.046 for 5 minutes in a developer solution. The result of scanning positive film is in the form of digital radiography which allows for the transfer of digital data or computerized storage of digital data. This status is still within limits acceptable under the standards referred. (author)

  7. Effects of multidisciplinary teamwork on lead times and patient flow in the emergency department: a longitudinal interventional cohort study.

    Science.gov (United States)

    Muntlin Athlin, Asa; von Thiele Schwarz, Ulrica; Farrohknia, Nasim

    2013-11-01

    Long waiting times for emergency care are claimed to be caused by overcrowded emergency departments and non-effective working routines. Teamwork has been suggested as a promising solution to these issues. The aim of the present study was to investigate the effects of teamwork in a Swedish emergency department on lead times and patient flow. The study was set in an emergency department of a university hospital where teamwork, a multi-professional team responsible for the whole care process for a group of patients, was introduced. The study has a longitudinal non-randomized intervention study design. Data were collected for five two-week periods during a period of 1.5 years. The first part of the data collection used an ABAB design whereby standard procedure (A) was altered weekly with teamwork (B). Then, three follow-ups were conducted. At last follow-up, teamwork was permanently implemented. The outcome measures were: number of patients handled within teamwork time, time to physician, total visit time and number of patients handled within the 4-hour target. A total of 1,838 patient visits were studied. The effect on lead times was only evident at the last follow-up. Findings showed that the number of patients handled within teamwork time was almost equal between the different study periods. At the last follow-up, the median time to physician was significantly decreased by 11 minutes (p = 0.0005) compared to the control phase and the total visit time was significantly shorter at last follow-up compared to control phase (p = Teamwork seems to contribute to the quality improvement of emergency care in terms of small but significant decreases in lead times. However, although efficient work processes such as teamwork are necessary to ensure safe patient care, it is likely not sufficient for bringing about larger decreases in lead times or for meeting the 4-hour target in the emergency department.

  8. 77 FR 12792 - Notice of Forest Service Land Management Plans To Be Amended To Incorporate Greater Sage-Grouse...

    Science.gov (United States)

    2012-03-02

    ... Forest Service Land Management Plans To Be Amended To Incorporate Greater Sage-Grouse Conservation... sage-grouse conservation measures into land use plans and land management plans. The BLM is the lead... submitted in writing until March 23, 2012. ADDRESSES: You may submit comments related to the greater sage...

  9. Decreased reaction time variability is associated with greater cardiovascular responses to acute stress.

    Science.gov (United States)

    Wawrzyniak, Andrew J; Hamer, Mark; Steptoe, Andrew; Endrighi, Romano

    2016-05-01

    Cardiovascular (CV) responses to mental stress are prospectively associated with poor CV outcomes. The association between CV responses to mental stress and reaction times (RTs) in aging individuals may be important but warrants further investigation. The present study assessed RTs to examine associations with CV responses to mental stress in healthy, older individuals using robust regression techniques. Participants were 262 men and women (mean age = 63.3 ± 5.5 years) from the Whitehall II cohort who completed a RT task (Stroop) and underwent acute mental stress (mirror tracing) to elicit CV responses. Blood pressure, heart rate, and heart rate variability were measured at baseline, during acute stress, and through a 75-min recovery. RT measures were generated from an ex-Gaussian distribution that yielded three predictors: mu-RT, sigma-RT, and tau-RT, the mean, standard deviation, and mean of the exponential component of the normal distribution, respectively. Decreased intraindividual RT variability was marginally associated with greater systolic (B = -.009, SE = .005, p = .09) and diastolic (B = -.004, SE = .002, p = .08) blood pressure reactivity. Decreased intraindividual RT variability was associated with impaired systolic blood pressure recovery (B = -.007, SE = .003, p = .03) and impaired vagal tone (B = -.0047, SE = .0024, p = .045). Study findings offer tentative support for an association between RTs and CV responses. Despite small effect sizes and associations not consistent across predictors, these data may point to a link between intrinsic neuronal plasticity and CV responses. © 2016 The Authors. Psychophysiology published by Wiley Periodicals, Inc. on behalf of Society for Psychophysiological Research.

  10. In vivo x-ray fluorescence of bone lead in the study of human lead metabolism: Serum lead, whole blood lead, bone lead, and cumulative exposure

    International Nuclear Information System (INIS)

    Cake, K.M.; Chettle, D.R.; Webber, C.E.; Gordon, C.L.

    1995-01-01

    Traditionally, clinical studies of lead's effect on health have relied on blood lead levels to indicate lead exposure. However, this is unsatisfactory because blood lead levels have a half-life of approximately 5 weeks, and thus reflect recent exposure. Over 90% of the lead body burden is in bone, and it is thought to have a long residence time, thus implying that measurements of bone lead reflect cumulative exposure. So, measurements of bone lead are useful in understanding the long-term health effects of lead. Ahlgren reported the first noninvasive measurements of bone lead in humans, where γ-rays from 57 Co were used to excite the K series x-rays of lead. The lead detection system at McMaster University uses a 109 Cd source which is positioned at the center of the detector face (HPGe) and a near backscatter (∼160 degrees) geometry. This arrangement allows great flexibility, since one can sample lead in a range of different bone sites due to a robust normalization technique which eliminates the need to correct for bone geometry, thickness of overlying tissue, and other related factors. The effective radiation dose to an adult during an x-ray fluorescence bone lead measurement is extremely low, being 35 nSv. This paper addresses the issue of how bone, whole blood, and serum lead concentrations can be related in order to understand a person's lead exposure history

  11. The dark side of creativity: biological vulnerability and negative emotions lead to greater artistic creativity.

    Science.gov (United States)

    Akinola, Modupe; Mendes, Wendy Berry

    2008-12-01

    Historical and empirical data have linked artistic creativity to depression and other affective disorders. This study examined how vulnerability to experiencing negative affect, measured with biological products, and intense negative emotions influenced artistic creativity. The authors assessed participants' baseline levels of an adrenal steroid (dehydroepiandrosterone-sulfate, or DHEAS), previously linked to depression, as a measure of affective vulnerability. They then manipulated emotional responses by randomly assigning participants to receive social rejection or social approval or to a nonsocial situation. Participants then completed artistic collages, which were later evaluated by artists. Results confirmed a person-by-situation interaction. Social rejection was associated with greater artistic creativity; however, the interaction between affective vulnerability (lower baseline DHEAS) and condition was significant, suggesting that situational triggers of negative affect were especially influential among those lower in DHEAS, which resulted in the most creative products. These data provide evidence of possible biological and social pathways to artistic creativity.

  12. The Dark Side of Creativity: Biological Vulnerability and Negative Emotions Lead to Greater Artistic Creativity

    Science.gov (United States)

    Akinola, Modupe; Mendes, Wendy Berry

    2009-01-01

    Historical and empirical data have linked artistic creativity to depression and other affective disorders. This study examined how vulnerability to experiencing negative affect, measured with biological products, and intense negative emotions influenced artistic creativity. The authors assessed participants' baseline levels of an adrenal steroid (dehydroepiandrosterone-sulfate, or DHEAS), previously linked to depression, as a measure of affective vulnerability. They then manipulated emotional responses by randomly assigning participants to receive social rejection or social approval or to a nonsocial situation. Participants then completed artistic collages, which were later evaluated by artists. Results confirmed a person-by-situation interaction. Social rejection was associated with greater artistic creativity; however, the interaction between affective vulnerability (lower baseline DHEAS) and condition was significant, suggesting that situational triggers of negative affect were especially influential among those lower in DHEAS, which resulted in the most creative products. These data provide evidence of possible biological and social pathways to artistic creativity. PMID:18832338

  13. Greater confinement disposal of radioactive wastes

    International Nuclear Information System (INIS)

    Trevorrow, L.E.; Gilbert, T.L.; Luner, C.; Merry-Libby, P.A.; Meshkov, N.K.; Yu, C.

    1985-01-01

    Low-level radioactive waste (LLW) includes a broad spectrum of different radionuclide concentrations, half-lives, and hazards. Standard shallow-land burial practice can provide adequate protection of public health and safety for most LLW. A small volume fraction (approx. 1%) containing most of the activity inventory (approx. 90%) requires specific measures known as greater-confinement disposal (GCD). Different site characteristics and different waste characteristics - such as high radionuclide concentrations, long radionuclide half-lives, high radionuclide mobility, and physical or chemical characteristics that present exceptional hazards - lead to different GCD facility design requirements. Facility design alternatives considered for GCD include the augered shaft, deep trench, engineered structure, hydrofracture, improved waste form, and high-integrity container. Selection of an appropriate design must also consider the interplay between basic risk limits for protection of public health and safety, performance characteristics and objectives, costs, waste-acceptance criteria, waste characteristics, and site characteristics

  14. Lead identification in soil surrounding a used lead acid battery smelter area in Banten, Indonesia

    International Nuclear Information System (INIS)

    Adventini, N; Santoso, M; Lestiani, D D; Syahfitri, W Y N; Rixson, L

    2017-01-01

    A used lead acid battery smelter generates particulates containing lead that can contaminate the surrounding environment area. Lead is a heavy metal which is harmful to health if it enters the human body through soil, air, or water. An identification of lead in soil samples surrounding formal and informal used lead acid battery smelters area in Banten, Indonesia using EDXRF has been carried out. The EDXRF accuracy and precision evaluated from marine sediment IAEA 457 gave a good agreement to the certified value. A number of 16 soil samples from formal and informal areas and 2 soil samples from control area were taken from surface and subsurface soils. The highest lead concentrations from both lead smelter were approximately 9 folds and 11 folds higher than the reference and control samples. The assessment of lead contamination in soils described in C f index was in category: moderately and strongly polluted by lead for formal and informal lead smelter. Daily lead intake of children in this study from all sites had exceeded the recommended dietary allowance. The HI values for adults and children living near both lead smelter areas were greater than the value of safety threshold 1. This study finding confirmed that there is a potential health risk for inhabitants surrounding the used lead acid battery smelter areas in Banten, Indonesia. (paper)

  15. Standard test method for graphite furnace atomic absorption spectrometric determination of lead and cadmium extracted from ceramic foodware

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2000-01-01

    1.1 This test method covers procedures for using graphite furnace atomic absorption spectroscopy (GFAAS) to quantitatively determine lead and cadmium extracted by acetic acid at room temperature from the food-contact surface of foodware. The method is applicable to food-contact surfaces composed of silicate-based materials (earthenware, glazed ceramicware, decorated ceramicware, decorated glass, and lead crystal glass) and is capable of determining lead concentrations greater than 0.005 to 0.020 g/mL and cadmium concentrations greater than 0.0005 to 0.002 g/mL, depending on instrument design. 1.2 This test method also describes quality control procedures to check for contamination and matrix interference during GFAAS analyses and a specific sequence of analytical measurements that demonstrates proper instrument operation during the time period in which sample solutions are analyzed. 1.3 Cleaning and other contamination control procedures are described in this test method. Users may modify contamination cont...

  16. Estimates of over-diagnosis of breast cancer due to population-based mammography screening in South Australia after adjustment for lead time effects.

    Science.gov (United States)

    Beckmann, Kerri; Duffy, Stephen W; Lynch, John; Hiller, Janet; Farshid, Gelareh; Roder, David

    2015-09-01

    To estimate over-diagnosis due to population-based mammography screening using a lead time adjustment approach, with lead time measures based on symptomatic cancers only. Women aged 40-84 in 1989-2009 in South Australia eligible for mammography screening. Numbers of observed and expected breast cancer cases were compared, after adjustment for lead time. Lead time effects were modelled using age-specific estimates of lead time (derived from interval cancer rates and predicted background incidence, using maximum likelihood methods) and screening sensitivity, projected background breast cancer incidence rates (in the absence of screening), and proportions screened, by age and calendar year. Lead time estimates were 12, 26, 43 and 53 months, for women aged 40-49, 50-59, 60-69 and 70-79 respectively. Background incidence rates were estimated to have increased by 0.9% and 1.2% per year for invasive and all breast cancer. Over-diagnosis among women aged 40-84 was estimated at 7.9% (0.1-12.0%) for invasive cases and 12.0% (5.7-15.4%) when including ductal carcinoma in-situ (DCIS). We estimated 8% over-diagnosis for invasive breast cancer and 12% inclusive of DCIS cancers due to mammography screening among women aged 40-84. These estimates may overstate the extent of over-diagnosis if the increasing prevalence of breast cancer risk factors has led to higher background incidence than projected. © The Author(s) 2015.

  17. Effective production planning for purchased part under long lead time and uncertain demand: MRP Vs demand-driven MRP

    Science.gov (United States)

    Shofa, M. J.; Moeis, A. O.; Restiana, N.

    2018-04-01

    MRP as a production planning system is appropriate for the deterministic environment. Unfortunately, most production systems such as customer demands are stochastic, so that MRP is inappropriate at the time. Demand-Driven MRP (DDMRP) is new approach for production planning system dealing with demand uncertainty. The objective of this paper is to compare the MRP and DDMRP for purchased part under long lead time and uncertain demand in terms of average inventory levels. The evaluation is conducted through a discrete event simulation with the long lead time and uncertain demand scenarios. The next step is evaluating the performance of DDMRP by comparing the inventory level of DDMRP with MRP. As result, DDMRP is more effective production planning than MRP in terms of average inventory levels.

  18. Professional Rugby Union players have a 60% greater risk of time loss injury after concussion: a 2-season prospective study of clinical outcomes

    Science.gov (United States)

    Cross, Matthew; Kemp, Simon; Smith, Andrew; Trewartha, Grant; Stokes, Keith

    2016-01-01

    Aim To investigate incidence of concussion, clinical outcomes and subsequent injury risk following concussion. Methods In a two-season (2012/2013, 2013/2014) prospective cohort study, incidence of diagnosed match concussions (injuries/1000 h), median time interval to subsequent injury of any type (survival time) and time spent at each stage of the graduated return to play pathway were determined in 810 professional Rugby Union players (1176 player seasons). Results Match concussion incidence was 8.9/1000 h with over 50% occurring in the tackle. Subsequent incidence of any injury for players who returned to play in the same season following a diagnosed concussion (122/1000 h, 95% CI 106 to 141) was 60% higher (IRR 1.6, 95% CI 1.4 to 1.8) than for those who did not sustain a concussion (76/1000 h, 95% CI 72 to 80). Median time to next injury following return to play was shorter following concussion (53 days, 95% CI 41 to 64) than following non-concussive injuries (114 days, 95% CI 85 to 143). 38% of players reported recurrence of symptoms or failed to match their baseline neurocognitive test during the graduated return to play protocol. Summary and conclusions Players who returned to play in the same season after a diagnosed concussion had a 60% greater risk of time-loss injury than players without concussion. A substantial proportion of players reported recurrence of symptoms or failed to match baseline neurocognitive test scores during graduated return to play. These data pave the way for trials of more conservative and comprehensive graduated return to play protocols, with a greater focus on active rehabilitation. PMID:26626266

  19. Nurses: Leading change one day at a time.

    Science.gov (United States)

    Chubbs, Katherine

    2014-06-01

    There has been enormous progress in nursing, and that progress did not come without change. Nurses have two choices: to be a part of developing and leading the change, or to have change happen to them. Copyright © 2014 Longwoods Publishing.

  20. Superconductivity in nanostructured lead

    Science.gov (United States)

    Lungu, Anca; Bleiweiss, Michael; Amirzadeh, Jafar; Saygi, Salih; Dimofte, Andreea; Yin, Ming; Iqbal, Zafar; Datta, Timir

    2001-01-01

    Three-dimensional nanoscale structures of lead were fabricated by electrodeposition of pure lead into artificial porous opal. The size of the metallic regions was comparable to the superconducting coherence length of bulk lead. Tc as high as 7.36 K was observed, also d Tc/d H was 2.7 times smaller than in bulk lead. Many of the characteristics of these differ from bulk lead, a type I superconductor. Irreversibility line and magnetic relaxation rates ( S) were also studied. S( T) displayed two maxima, with a peak value about 10 times smaller than that of typical high- Tc superconductors.

  1. Greater-confinement disposal of low-level radioactive wastes

    International Nuclear Information System (INIS)

    Trevorrow, L.E.; Gilbert, T.L.; Luner, C.; Merry-Libby, P.A.; Meshkov, N.K.; Yu, C.

    1985-01-01

    Low-level radioactive wastes include a broad spectrum of wastes that have different radionuclide concentrations, half-lives, and physical and chemical properties. Standard shallow-land burial practice can provide adequate protection of public health and safety for most low-level wastes, but a small volume fraction (about 1%) containing most of the activity inventory (approx.90%) requires specific measures known as ''greater-confinement disposal'' (GCD). Different site characteristics and different waste characteristics - such as high radionuclide concentrations, long radionuclide half-lives, high radionuclide mobility, and physical or chemical characteristics that present exceptional hazards - lead to different GCD facility design requirements. Facility design alternatives considered for GCD include the augered shaft, deep trench, engineered structure, hydrofracture, improved waste form, and high-integrity container. Selection of an appropriate design must also consider the interplay between basic risk limits for protection of public health and safety, performance characteristics and objectives, costs, waste-acceptance criteria, waste characteristics, and site characteristics. This paper presents an overview of the factors that must be considered in planning the application of methods proposed for providing greater confinement of low-level wastes. 27 refs

  2. Optimization of the precordial leads of the 12-lead electrocardiogram may improve detection of ST-segment elevation myocardial infarction.

    Science.gov (United States)

    Scott, Peter J; Navarro, Cesar; Stevenson, Mike; Murphy, John C; Bennett, Johan R; Owens, Colum; Hamilton, Andrew; Manoharan, Ganesh; Adgey, A A Jennifer

    2011-01-01

    For the assessment of patients with chest pain, the 12-lead electrocardiogram (ECG) is the initial investigation. Major management decisions are based on the ECG findings, both for attempted coronary artery revascularization and risk stratification. The aim of this study was to determine if the current 6 precordial leads (V(1)-V(6)) are optimally located for the detection of ST-segment elevation in ST-segment elevation myocardial infarction (STEMI). We analyzed 528 (38% anterior [200], 44% inferior [233], and 18% lateral [95]) patients with STEMI with both a 12-lead ECG and an 80-lead body surface map (BSM) ECG (Prime ECG, Heartscape Technologies, Bangor, Northern Ireland). Body surface map was recorded within 15 minutes of the 12-lead ECG during the acute event and before revascularization. ST-segment elevation of each lead on the BSM was compared with the corresponding 12-lead precordial leads (V(1)-V(6)) for anterior STEMI. In addition, for lateral STEMI, leads I and aVL of the BSM were also compared; and limb leads II, III, aVF of the BSM were compared with inferior unipolar BSM leads for inferior STEMI. Leads with the greatest mean ST-segment elevation were selected, and significance was determined by analysis of variance of the mean ST segment. For anterior STEMI, leads V(1), V(2), 32, 42, 51, and 57 had the greatest mean ST elevation. These leads are located in the same horizontal plane as that of V(1) and V(2). Lead 32 had a significantly greater mean ST elevation than the corresponding precordial lead V(3) (P = .012); and leads 42, 51, and 57 were also significantly greater than corresponding leads V(4), V(5), V(6), respectively (P mean ST-segment elevation; and lead III was significantly superior to the inferior unipolar leads (7, 17, 27, 37, 47, 55, and 61) of the BSM (P optimal placement for the diagnosis of anterior and lateral STEMI and appear superior to leads V(3), V(4), V(5), and V(6). This is of significant clinical interest, not only for ease and

  3. Ensemble hydrological forecast efficiency evolution over various issue dates and lead-time: case study for the Cheboksary reservoir (Volga River)

    Science.gov (United States)

    Gelfan, Alexander; Moreido, Vsevolod

    2017-04-01

    Ensemble hydrological forecasting allows for describing uncertainty caused by variability of meteorological conditions in the river basin for the forecast lead-time. At the same time, in snowmelt-dependent river basins another significant source of uncertainty relates to variability of initial conditions of the basin (snow water equivalent, soil moisture content, etc.) prior to forecast issue. Accurate long-term hydrological forecast is most crucial for large water management systems, such as the Cheboksary reservoir (the catchment area is 374 000 sq.km) located in the Middle Volga river in Russia. Accurate forecasts of water inflow volume, maximum discharge and other flow characteristics are of great value for this basin, especially before the beginning of the spring freshet season that lasts here from April to June. The semi-distributed hydrological model ECOMAG was used to develop long-term ensemble forecast of daily water inflow into the Cheboksary reservoir. To describe variability of the meteorological conditions and construct ensemble of possible weather scenarios for the lead-time of the forecast, two approaches were applied. The first one utilizes 50 weather scenarios observed in the previous years (similar to the ensemble streamflow prediction (ESP) procedure), the second one uses 1000 synthetic scenarios simulated by a stochastic weather generator. We investigated the evolution of forecast uncertainty reduction, expressed as forecast efficiency, over various consequent forecast issue dates and lead time. We analyzed the Nash-Sutcliffe efficiency of inflow hindcasts for the period 1982 to 2016 starting from 1st of March with 15 days frequency for lead-time of 1 to 6 months. This resulted in the forecast efficiency matrix with issue dates versus lead-time that allows for predictability identification of the basin. The matrix was constructed separately for observed and synthetic weather ensembles.

  4. Comparison of the radiological and chemical toxicity of lead

    Energy Technology Data Exchange (ETDEWEB)

    Beitel, G.A.; Mott, S.

    1995-03-01

    This report estimates the worst-case radiological dose to an individual from ingested lead containing picocurie levels of radionuclides and then compares the calculated radiological health effects to the chemical toxic effects from that same lead. This comparison provides an estimate of the consequences of inadvertently recycling, in the commercial market, lead containing nominally undetectable concentrations of radionuclides. Quantitative expressions for the radiological and chemical toxicities of lead are based on concentrations of lead in the blood stream. The result shows that the chemical toxicity of lead is a greater health hazard, by orders of magnitude, than any probable companion radiation dose.

  5. Comparison of the radiological and chemical toxicity of lead

    International Nuclear Information System (INIS)

    Beitel, G.A.; Mott, S.

    1995-03-01

    This report estimates the worst-case radiological dose to an individual from ingested lead containing picocurie levels of radionuclides and then compares the calculated radiological health effects to the chemical toxic effects from that same lead. This comparison provides an estimate of the consequences of inadvertently recycling, in the commercial market, lead containing nominally undetectable concentrations of radionuclides. Quantitative expressions for the radiological and chemical toxicities of lead are based on concentrations of lead in the blood stream. The result shows that the chemical toxicity of lead is a greater health hazard, by orders of magnitude, than any probable companion radiation dose

  6. The boreal winter Madden-Julian Oscillation's influence on summertime precipitation in the greater Caribbean

    Science.gov (United States)

    Curtis, Scott; Gamble, Douglas W.

    2016-07-01

    Precipitation totals in the greater Caribbean are known to be affected by interannual variability. In particular, dry conditions in the spring-summer have been physically linked to the positive phase of North Atlantic Oscillation (NAO) in the literature. In this study, it was found through regression analysis that an active Madden-Julian Oscillation (MJO) in winter geographically focused over the Maritime Continent contributes to a positive NAO in March via the generation of Rossby waves in the Northern Hemisphere. Specifically, a negative Pacific-North American pattern develops in the winter and transitions to an Atlantic pattern in spring. The positive NAO is a transient feature of this evolving wave train, but a center of significant positive 200 hPa geopotential heights is entrenched over the southeast U.S. throughout the February to May time period and is manifested as high pressure at the surface. The southern flank of this system increases the speeds of the trade winds and leads to a cooling of the Caribbean sea surface temperatures and, thus, convection suppression and reduced precipitation. Thus, this study advances our understanding of the climate of the greater Caribbean by using climate teleconnections to relate the MJO to rainfall in the region.

  7. Quantum process tomography with informational incomplete data of two J-coupled heterogeneous spins relaxation in a time window much greater than T1

    Science.gov (United States)

    Maciel, Thiago O.; Vianna, Reinaldo O.; Sarthour, Roberto S.; Oliveira, Ivan S.

    2015-11-01

    We reconstruct the time dependent quantum map corresponding to the relaxation process of a two-spin system in liquid-state NMR at room temperature. By means of quantum tomography techniques that handle informational incomplete data, we show how to properly post-process and normalize the measurements data for the simulation of quantum information processing, overcoming the unknown number of molecules prepared in a non-equilibrium magnetization state (Nj) by an initial sequence of radiofrequency pulses. From the reconstructed quantum map, we infer both longitudinal (T1) and transversal (T2) relaxation times, and introduce the J-coupling relaxation times ({T}1J,{T}2J), which are relevant for quantum information processing simulations. We show that the map associated to the relaxation process cannot be assumed approximated unital and trace-preserving for times greater than {T}2J.

  8. An integrated supply chain inventory model with imperfect-quality items, controllable lead time and distribution-free demand

    Directory of Open Access Journals (Sweden)

    Lin Hsien-Jen

    2013-01-01

    Full Text Available In this paper, we consider an integrated vendor-buyer inventory policy for a continuous review model with a random number of defective items and screening process gradually at a fixed screening rate in buyer’s arriving order lot. We assume that shortages are allowed and partially backlogged on the buyer’s side, and that the lead time demand distribution is unknown, except its first two moments. The objective is to apply the minmax distribution free approach to determine the optimal order quantity, reorder point, lead time and the number of lots delivered in one production run simultaneously so that the expected total system cost is minimized. Numerical experiments along with sensitivity analysis were performed to illustrate the effects of parameters on the decision and the total system cost.

  9. Time-bound promotions in Indian medical institutes: a mirage?

    Science.gov (United States)

    Sukhlecha, Anupama

    2016-01-01

    Incentives, pay hikes and timely promotions enhance the job performance of an employee. In medical institutes, too, satisfied teachers would train students in a better way leading to better equipped doctors and ultimately, greater patient satisfaction. A study in Malaysia links high levels of satisfaction of employees with good salary, promotions, and incentives.

  10. Uranium-lead systematics

    International Nuclear Information System (INIS)

    Wickman, F.E.

    1983-01-01

    The method of Levchenkov and Shukolyukov for calculating age and time disturbance of minerals without correction for original lead is generalized to include the cases when (1) original lead and radiogenic lead leach differently, and (2) the crystals studied consist of a core and a mantle. It is also shown that a straight line obtained from the solution of the equations is the locus of the isotopic composition of original lead. (Auth.)

  11. A single-vendor and a single-buyer integrated inventory model with ordering cost reduction dependent on lead time

    Science.gov (United States)

    Vijayashree, M.; Uthayakumar, R.

    2017-09-01

    Lead time is one of the major limits that affect planning at every stage of the supply chain system. In this paper, we study a continuous review inventory model. This paper investigates the ordering cost reductions are dependent on lead time. This study addressed two-echelon supply chain problem consisting of a single vendor and a single buyer. The main contribution of this study is that the integrated total cost of the single vendor and the single buyer integrated system is analyzed by adopting two different (linear and logarithmic) types ordering cost reductions act dependent on lead time. In both cases, we develop effective solution procedures for finding the optimal solution and then illustrative numerical examples are given to illustrate the results. The solution procedure is to determine the optimal solutions of order quantity, ordering cost, lead time and the number of deliveries from the single vendor and the single buyer in one production run, so that the integrated total cost incurred has the minimum value. Ordering cost reduction is the main aspect of the proposed model. A numerical example is given to validate the model. Numerical example solved by using Matlab software. The mathematical model is solved analytically by minimizing the integrated total cost. Furthermore, the sensitivity analysis is included and the numerical examples are given to illustrate the results. The results obtained in this paper are illustrated with the help of numerical examples. The sensitivity of the proposed model has been checked with respect to the various major parameters of the system. Results reveal that the proposed integrated inventory model is more applicable for the supply chain manufacturing system. For each case, an algorithm procedure of finding the optimal solution is developed. Finally, the graphical representation is presented to illustrate the proposed model and also include the computer flowchart in each model.

  12. Real Time Corrosion Monitoring in Lead and Lead-Bismuth Systems

    Energy Technology Data Exchange (ETDEWEB)

    James F. Stubbins; Alan Bolind; Ziang Chen

    2010-02-25

    The objective of this research program is to develop a real-time, in situ corrosion monitoring technique for flowing liquid Pb and eutectic PbBi (LBE) systems in a temperature range of 400 to 650 C. These conditions are relevant to future liquid metal cooled fast reactor operating parameters. THis program was aligned with the Gen IV Reactor initiative to develp technologies to support the design and opertion of a Pb or LBE-cooled fast reactor. The ability to monitor corrosion for protection of structural components is a high priority issue for the safe and prolonged operation of advanced liquid metal fast reactor systems. In those systems, protective oxide layers are intentionally formed and maintained to limit corrosion rates during operation. This program developed a real time, in situ corrosion monitoring tecnique using impedance spectroscopy (IS) technology.

  13. Do ewes born with a male co-twin have greater longevity with lambing over time?

    Science.gov (United States)

    Based on a recent analysis of historical records, ewes born co-twin to a ram had greater lifetime reproductive performance than ewes born co-twin to a ewe. We are interested in determining what component(s) of lifetime reproductive performance may be associated with a ewe’s co-twin sex. As an initi...

  14. Modularity, Lead time and Return Policy for Supply Chain in Mass Customization System

    Directory of Open Access Journals (Sweden)

    Jizi Li

    2016-12-01

    Full Text Available Mass Customization (MC is a flexible manufacturing system with features of Mass Production (MP and Customization Production (CP. However, there is few researches about competition aamp; cooperation between the upstream MP firm (module manufacturer and downstream CP firm (assembler under MC supply chain scenario. From supply chain perspective, this paper first develops the base models considering the influences of return policy, modularity level, production lead time and pricing factors. Furthermore, according to the different decision-making situations, three kinds of MC supply chain models in competitive or cooperative environment (i.e. simultaneous-move game, sequential-move game and the cooperative game have been built, then, the optimal solution of each model have been analyzed and compared, and coordination mechanism is design to cooperate in MC supply chain via profit-sharing with Nash bargaining power. Finally, through the numerical analysis, we find the highest profit is from the cooperative setting, then followed by in simultaneous-move and sequential-move one, the reason is that the lowest product price and the largest market demand easily occurs in the cooperative game compared with the others, the upstream module manufacturer takes advantage of MP to increase the modularity level and decrease manufacturing cost for the whole supply chain, the downstream assembler task is to shorten the lead time according to customerarsquo;s needs, while the wholesale price in cooperative game higher than simultaneous-move game and sequential-move game can ensure each firmarsquo;s benefits, effectively prevent from the effect of double marginalization and obtain Pareto optimality.

  15. Cumulant generating function formula of heat transfer in ballistic systems with lead-lead coupling

    Science.gov (United States)

    Li, Huanan; Agarwalla, Bijay Kumar; Wang, Jian-Sheng

    2012-10-01

    Based on a two-time observation protocol, we consider heat transfer in a given time interval tM in a lead-junction-lead system taking coupling between the leads into account. In view of the two-time observation, consistency conditions are carefully verified in our specific family of quantum histories. Furthermore, its implication is briefly explored. Then using the nonequilibrium Green's function method, we obtain an exact formula for the cumulant generating function for heat transfer between the two leads, valid in both transient and steady-state regimes. Also, a compact formula for the cumulant generating function in the long-time limit is derived, for which the Gallavotti-Cohen fluctuation symmetry is explicitly verified. In addition, we briefly discuss Di Ventra's repartitioning trick regarding whether the repartitioning procedure of the total Hamiltonian affects the nonequilibrium steady-state current fluctuation. All kinds of properties of nonequilibrium current fluctuations, such as the fluctuation theorem in different time regimes, could be readily given according to these exact formulas.

  16. The effect of interior lead hazard controls on children's blood lead concentrations: a systematic evaluation.

    Science.gov (United States)

    Haynes, Erin; Lanphear, Bruce P; Tohn, Ellen; Farr, Nick; Rhoads, George G

    2002-01-01

    Dust control is often recommended to prevent children's exposure to residential lead hazards, but the effect of these controls on children's blood lead concentrations is uncertain. We conducted a systematic review of randomized, controlled trials of low-cost, lead hazard control interventions to determine the effect of lead hazard control on children's blood lead concentration. Four trials met the inclusion criteria. We examined mean blood lead concentration and elevated blood lead concentrations (> or = 10 microg/dL, > or = 15 microg/dL, and > or = 20 microg/dL) and found no significant differences in mean change in blood lead concentration for children by random group assignment (children assigned to the intervention group compared with those assigned to the control group). We found no significant difference between the intervention and control groups in the percentage of children with blood lead > or = 10 microg/dL, 29% versus 32% [odds ratio (OR), 0.85; 95% confidence interval (CI), 0.56-1.3], but there was a significant difference in the percentage of children with blood lead > or = 15 microg/dL between the intervention and control groups, 6% versus 14% (OR, 0.40; 95% CI, 0.21-0.80) and in the percentage of children with blood lead > or = 20 microg/dL between the intervention and control groups, 2% versus 6% (OR, 0.29; 95% CI, 0.10-0.85). We conclude that although low-cost, interior lead hazard control was associated with 50% or greater reduction in the proportion of children who had blood lead concentrations exceeding 15 microg/dL and > or = 20 microg/dL, there was no substantial effect on mean blood lead concentration.

  17. Eveningness and Later Sleep Timing Are Associated with Greater Risk for Alcohol and Marijuana Use in Adolescence: Initial Findings from the National Consortium on Alcohol and Neurodevelopment in Adolescence Study.

    Science.gov (United States)

    Hasler, Brant P; Franzen, Peter L; de Zambotti, Massimiliano; Prouty, Devin; Brown, Sandra A; Tapert, Susan F; Pfefferbaum, Adolf; Pohl, Kilian M; Sullivan, Edith V; De Bellis, Michael D; Nagel, Bonnie J; Baker, Fiona C; Colrain, Ian M; Clark, Duncan B

    2017-06-01

    Abundant cross-sectional evidence links eveningness (a preference for later sleep-wake timing) and increased alcohol and drug use among adolescents and young adults. However, longitudinal studies are needed to examine whether eveningness is a risk factor for subsequent alcohol and drug use, particularly during adolescence, which is marked by parallel peaks in eveningness and risk for the onset of alcohol use disorders. This study examined whether eveningness and other sleep characteristics were associated with concurrent or subsequent substance involvement in a longitudinal study of adolescents. Participants were 729 adolescents (368 females; age 12 to 21 years) in the National Consortium on Alcohol and Neurodevelopment in Adolescence study. Associations between the sleep variables (circadian preference, sleep quality, daytime sleepiness, sleep timing, and sleep duration) and 3 categorical substance variables (at-risk alcohol use, alcohol bingeing, and past-year marijuana use [y/n]) were examined using ordinal and logistic regression with baseline age, sex, race, ethnicity, socioeconomic status, and psychiatric problems as covariates. At baseline, greater eveningness was associated with greater at-risk alcohol use, greater bingeing, and past-year use of marijuana. Later weekday and weekend bedtimes, but not weekday or weekend sleep duration, showed similar associations across the 3 substance outcomes at baseline. Greater baseline eveningness was also prospectively associated with greater bingeing and past-year use of marijuana at the 1-year follow-up, after covarying for baseline bingeing and marijuana use. Later baseline weekday and weekend bedtimes, and shorter baseline weekday sleep duration, were similarly associated with greater bingeing and past-year use of marijuana at the 1-year follow-up after covarying for baseline values. Findings suggest that eveningness and sleep timing may be under recognized risk factors and future areas of intervention for

  18. Lead concentrations and reproduction in highway-nesting barn swallows

    Science.gov (United States)

    Grue, C.E.; O'Shea, T.J.; Hoffman, D.J.

    1984-01-01

    Swallows (Hirundo rustica) collected within the right-of-way of a major Maryland highway were greater than those found in Barn Swallows nesting within a rural area. Lead concentrations in the feathers of adults from the highway colony were also greater than Lead concentrations in the carcasses and stomach contents of adult and nestling Barn those of rural adults, but concentrations in the feathers of nestlings from the two locations were similar. Activity of u-aminolevulinic acid dehydratase in red blood cells was lower in highway-nesting adults and their young than in their rural counterparts, although hemoglobin concentrations and hematocrits did not differ. The number of eggs, nestlings, and body weights of the latter at 16-18 days of age were similar in the two colonies, as were body weights of adults from the two areas. These results suggest that contamination of roadside habitats by lead from automotive emissions does not pose a serious hazard to birds that are aerial feeders.

  19. Environmental lead exposure among preschool children in Shanghai, China: blood lead levels and risk factors.

    Directory of Open Access Journals (Sweden)

    Jia Cao

    Full Text Available OBJECTIVE: To determine blood lead levels and to identify related risk factors among children in Shanghai; to explore the lead change trend of children after industrial transformation and to provide data for policy development to control environmental lead pollution in Shanghai. METHODS: A stratified-clustered-random sampling method was used. A tungsten atomizer absorption spectrophotometer was employed to determine blood lead levels. RESULTS: The arithmetic mean, geometric mean and median of blood lead levels of 0- to 6-year-old children from Shanghai were 22.49 µg/L, 19.65 µg/L and 19.5 µg/L, including 0.26% (6/2291 with concentrations ≥100 µg/L and 2.7% (61/2291 with concentrations ≥50 µg/L. Boys' levels (23.57 µg/L were greater than those of girls (21.2 µg/L. The blood lead levels increased with age. This survey showed that the Chongming district was the highest and Yangpu district was the lowest, this result is completely opposite with the earlier survey in Shanghai. Risk factors for lead contamination included housing environment, parents' education levels, social status, hobbies, and children's nutritional status. CONCLUSIONS: The blood lead levels of children in Shanghai were lower than the earlier data of Shanghai and those of published studies in China, but higher than the blood lead levels of developed countries. The blood lead levels of urban districts are higher than the central districts with the industrial transformation. Society and the government should take an active interest in childhood lead poisoning of urban areas.

  20. Health impact from lead: IQ decrement

    Energy Technology Data Exchange (ETDEWEB)

    Easterly, C

    1994-07-01

    The effects of lead, once it is in the body, are the same no matter how it enters. Exposure to lead is especially dangerous for unborn children, with high levels associated with premature birth and low birth weight. Young children are at risk because they swallow lead when they put toys or other objects soiled with lead-containing dirt in their mouths. A greater proportion of the lead ingested by children enters their bodies than enters the bodies of adults. For infants and young children, lead exposure has been shown in some studies to decrease intelligence (IQ) scores, slow growth, and cause hearing problems. These effects can last as children get older and can be permanent. Realistic risk assessment for lead-induced neurobehavioral deficit in environmentally exposed children must stem from consistent results from independent studies, as well as the documentation of dose-response relationships. At present, studies investigating such effects have not been definitive. However, taken as a whole, there is growing support for the absence of a threshold for adverse effects in exposed children. Summary of selected recent studies and the obtained data are analyzed.

  1. Health impact from lead: IQ decrement

    International Nuclear Information System (INIS)

    Easterly, C.

    1994-01-01

    The effects of lead, once it is in the body, are the same no matter how it enters. Exposure to lead is especially dangerous for unborn children, with high levels associated with premature birth and low birth weight. Young children are at risk because they swallow lead when they put toys or other objects soiled with lead-containing dirt in their mouths. A greater proportion of the lead ingested by children enters their bodies than enters the bodies of adults. For infants and young children, lead exposure has been shown in some studies to decrease intelligence (IQ) scores, slow growth, and cause hearing problems. These effects can last as children get older and can be permanent. Realistic risk assessment for lead-induced neurobehavioral deficit in environmentally exposed children must stem from consistent results from independent studies, as well as the documentation of dose-response relationships. At present, studies investigating such effects have not been definitive. However, taken as a whole, there is growing support for the absence of a threshold for adverse effects in exposed children. Summary of selected recent studies and the obtained data are analyzed

  2. Wildfire and forest disease interaction lead to greater loss of soil nutrients and carbon.

    Science.gov (United States)

    Cobb, Richard C; Meentemeyer, Ross K; Rizzo, David M

    2016-09-01

    Fire and forest disease have significant ecological impacts, but the interactions of these two disturbances are rarely studied. We measured soil C, N, Ca, P, and pH in forests of the Big Sur region of California impacted by the exotic pathogen Phytophthora ramorum, cause of sudden oak death, and the 2008 Basin wildfire complex. In Big Sur, overstory tree mortality following P. ramorum invasion has been extensive in redwood and mixed evergreen forests, where the pathogen kills true oaks and tanoak (Notholithocarpus densiflorus). Sampling was conducted across a full-factorial combination of disease/no disease and burned/unburned conditions in both forest types. Forest floor organic matter and associated nutrients were greater in unburned redwood compared to unburned mixed evergreen forests. Post-fire element pools were similar between forest types, but lower in burned-invaded compared to burned-uninvaded plots. We found evidence disease-generated fuels led to increased loss of forest floor C, N, Ca, and P. The same effects were associated with lower %C and higher PO4-P in the mineral soil. Fire-disease interactions were linear functions of pre-fire host mortality which was similar between the forest types. Our analysis suggests that these effects increased forest floor C loss by as much as 24.4 and 21.3 % in redwood and mixed evergreen forests, respectively, with similar maximum losses for the other forest floor elements. Accumulation of sudden oak death generated fuels has potential to increase fire-related loss of soil nutrients at the region-scale of this disease and similar patterns are likely in other forests, where fire and disease overlap.

  3. Spontaneous, generalized lipidosis in captive greater horseshoe bats (Rhinolophus ferrumequinum).

    Science.gov (United States)

    Gozalo, Alfonso S; Schwiebert, Rebecca S; Metzner, Walter; Lawson, Gregory W

    2005-11-01

    During a routine 6-month quarantine period, 3 of 34 greater horseshoe bats (Rhinolophus ferrumequinum) captured in mainland China and transported to the United States for use in echolocation studies were found dead with no prior history of illness. All animals were in good body condition at the time of death. At necropsy, a large amount of white fat was found within the subcutis, especially in the sacrolumbar region. The liver, kidneys, and heart were diffusely tan in color. Microscopic examination revealed that hepatocytes throughout the liver were filled with lipid, and in some areas, lipid granulomas were present. renal lesions included moderate amounts of lipid in the cortical tubular epithelium and large amounts of protein and lipid within Bowman's capsules in the glomeruli. In addition, one bat had large lipid vacuoles diffusely distributed throughout the myocardium. The exact pathologic mechanism inducing the hepatic, renal, and cardiac lipidosis is unknown. The horseshoe bats were captured during hibernation and immediately transported to the United States. It is possible that the large amount of fat stored coupled with changes in photoperiod, lack of exercise, and/or the stress of captivity might have contributed to altering the normal metabolic processes, leading to anorexia and consequently lipidosis in these animals.

  4. A computed tomography study in the location of greater palatine artery in South Indian population for maxillary osteotomy

    Directory of Open Access Journals (Sweden)

    I Packiaraj

    2016-01-01

    Full Text Available Introduction: The greater palatine artery is one of the important feeding vessel to the maxilla. The surgeon should know the surgical anatomy of greater palatine artery to avoid trauma in maxilla which leads to ischemic problems. Aim: The CT evaluation of the distance between Pyriform aperture and the greater palatine foramen in various ages of both sexes. Result: The distance varies according to sex and age which are measured by CT and standardised. Discussion: The lateral nasal osteotomy can be done upto 25 mm depth, instead of 20 mm. Conclusion: By this study it shows that the lateral nasal wall osteotomy can be performed without injury to greater palatine artery.

  5. Plerixafor mobilization leads to a lower ratio of CD34+ cells to total nucleated cells which results in greater storage costs.

    Science.gov (United States)

    Tanhehco, Yvette C; Adamski, Jill; Sell, Mary; Cunningham, Kathleen; Eisenmann, Christa; Magee, Deborah; Stadtmauer, Edward A; O'Doherty, Una

    2010-01-01

    Plerixafor (Mozobil, AMD3100) with granulocyte-colony stimulating factor (G-CSF) mobilizes more CD34+ cells/kg compared to G-CSF alone. Given that plerixafor enhances mobilization of multiple white blood cell lineages, we determined if more storage space is required for products collected from patients mobilized with plerixafor. A review of the medical records of 15 patients mobilized with chemotherapy and G-CSF (control) and 14 patients mobilized with plerixafor plus G-CSF (plerixafor) was performed. Data on demographics, baseline characteristics, CD34+ cells/kg, total nucleated cells, total mononuclear cells, total apheresis sessions, and total bags for storage were collected. Mean values were determined and compared using Student's t-test. We found that the proportion of CD34+ cells among total nucleated cells was less in the plerixafor group compared to the control group (P = 0.0427). More nucleated cells (10.7 x 10(10) vs. 7.1 x 10(10), P =0.0452) and mononuclear cells (9.7 x 10(10) vs. 5.9 x 10(10), P = 0.0059) were mobilized with plerixafor plus G-CSF. However, there was no significant difference in CD34+ cells/kg, total CD34+ cells or the proportion of mononuclear cells among total nucleated cells between the two groups. More storage bags were required for the plerixafor group compared to the control group (15 vs. 9, P = 0.0299). Mobilization with plerixafor plus G-CSF resulted in a smaller proportion of CD34+ cells collected and a greater number of storage bags. An increase in the number of bags required for stem cell storage may be logistically problematic and will also lead to increased costs for storage of stem cells.

  6. Time Domain View of Liquid-like Screening and Large Polaron Formation in Lead Halide Perovskites

    Science.gov (United States)

    Joshi, Prakriti Pradhan; Miyata, Kiyoshi; Trinh, M. Tuan; Zhu, Xiaoyang

    The structural softness and dynamic disorder of lead halide perovskites contributes to their remarkable optoelectronic properties through efficient charge screening and large polaron formation. Here we provide a direct time-domain view of the liquid-like structural dynamics and polaron formation in single crystal CH3NH3PbBr3 and CsPbBr3 using femtosecond optical Kerr effect spectroscopy in conjunction with transient reflectance spectroscopy. We investigate structural dynamics as function of pump energy, which enables us to examine the dynamics in the absence and presence of charge carriers. In the absence of charge carriers, structural dynamics are dominated by over-damped picosecond motions of the inorganic PbBr3- sub-lattice and these motions are strongly coupled to band-gap electronic transitions. Carrier injection from across-gap optical excitation triggers additional 0.26 ps dynamics in CH3NH3PbBr3 that can be attributed to the formation of large polarons. In comparison, large polaron formation is slower in CsPbBr3 with a time constant of 0.6 ps. We discuss how such dynamic screening protects charge carriers in lead halide perovskites. US Department of Energy, Office of Science - Basic Energy Sciences.

  7. Lead-time reduction utilizing lean tools applied to healthcare: the inpatient pharmacy at a local hospital.

    Science.gov (United States)

    Al-Araidah, Omar; Momani, Amer; Khasawneh, Mohammad; Momani, Mohammed

    2010-01-01

    The healthcare arena, much like the manufacturing industry, benefits from many aspects of the Toyota lean principles. Lean thinking contributes to reducing or eliminating nonvalue-added time, money, and energy in healthcare. In this paper, we apply selected principles of lean management aiming at reducing the wasted time associated with drug dispensing at an inpatient pharmacy at a local hospital. Thorough investigation of the drug dispensing process revealed unnecessary complexities that contribute to delays in delivering medications to patients. We utilize DMAIC (Define, Measure, Analyze, Improve, Control) and 5S (Sort, Set-in-order, Shine, Standardize, Sustain) principles to identify and reduce wastes that contribute to increasing the lead-time in healthcare operations at the pharmacy understudy. The results obtained from the study revealed potential savings of > 45% in the drug dispensing cycle time.

  8. Lead generation strategy as a multichannel mechanism of growth of a modern enterprise

    Directory of Open Access Journals (Sweden)

    Łukowski Wojciech

    2016-09-01

    Full Text Available Lead generation strategy describes the marketing process of involvement and capture of interest in a product or service which is aimed at developing sales plans and, as a consequence, soliciting new clients. Lead generation is becoming an increasingly popular demand-generating strategy, which – through its multichannelled dissemination of the generated message – gives it a much greater reach. Lead generation assists organisations in achieving a greater brand awareness, building relationships and attracting more potential clients to fill their sales pipeline. The primary purpose of this publication is identifying the possibilities that the implementation of lead generation strategies provides to modern enterprises. It discusses the key aspects of this issue, demonstrating how the significance of organisations change, how their value effectively increases as a result of the implementation of tools furnished by processes that form an integral part of lead generation. The article defines the factors and processes that affect the effective course of actions undertaken within lead generation campaigns.

  9. Timing of Conduction Abnormalities Leading to Permanent Pacemaker Insertion After Transcatheter Aortic Valve Implantation-A Single-Centre Review.

    Science.gov (United States)

    Ozier, Daniel; Zivkovic, Nevena; Elbaz-Greener, Gabby; Singh, Sheldon M; Wijeysundera, Harindra C

    2017-12-01

    Transcatheter aortic valve implantation (TAVI) is the preferred alternative to traditional surgical aortic valve replacement; however, it remains expensive. One potential driver of cost is the need for postprocedural monitoring for conduction abnormalities after TAVI. Given the paucity of literature on the optimal length of monitoring, we aimed to determine when clinically significant conduction abnormalities leading to permanent pacemaker (PPM) insertion after TAVI were first identified. We identified all patients in the Sunnybrook Health Sciences Centre TAVI registry (Toronto, Canada) who underwent TAVI between 2009 and 2016, excluding those with pre-existing PPMs or those who underwent emergency open heart surgery. Through dedicated chart review, the timing and type of conduction abnormalities leading to PPM were recorded. Patients were divided according to the timing of conduction abnormality: during the procedure vs after the procedure. The overall PPM insertion rate was 15.6% (80 of 512 cases), with all but 1 patient receiving a PPM for class I indications. PPMs were inserted for complete heart block/high-grade atrioventricular block (91.3%), severe sinus node dysfunction (3.8%), and alternating bundle branch block (3.8%). Of these conduction abnormalities, 55.0% occurred during the procedure (intraprocedure; n = 44 patients). The mean time to the development of a conduction abnormality necessitating PPM was 1.2 days (interquartile range, 0-2 days), with 88.8% occurring within 72 hours of the procedure (n = 71 patients). In the entire TAVI cohort, leading to PPM. The majority of conduction abnormalities leading to PPM insertion after TAVI occur in the very early periprocedural period, suggesting that early mobilization and discharge will be safe from a conduction standpoint. Copyright © 2017 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  10. Ferroelastic domain switching fatigue in lead zirconate titanate ceramics

    International Nuclear Information System (INIS)

    Pojprapai, Soodkhet; Jones, Jacob L.; Studer, Andrew J.; Russell, Jennifer; Valanoor, Nagarajan; Hoffman, Mark

    2008-01-01

    The influence of the frequency and amplitude of cyclic mechanical loading on soft, tetragonal lead zirconate titanate (PZT) ceramics was investigated via neutron diffraction. Intensity change in the {2 0 0} reflections provided quantitative measurements of domain switching behavior, domain texture and the strain resulting from domain switching. The results are explained using a viscoelasticity model. It was found that the magnitude of applied stress affects the level of strain accumulated, while its frequency affects the time taken for the strain to reach saturation. Furthermore, markedly different behaviors are exhibited by poled and unpoled samples. For samples loaded under identical conditions, the frequency effect is more pronounced in unpoled samples and the accumulated ferroelastic strain is greater in poled samples

  11. Natural convection in enclosures containing lead-bismuth and lead

    International Nuclear Information System (INIS)

    Dzodzo, M.; Cuckovic-Dzodzo, D.

    2001-01-01

    The design of liquid metal reactors such as Encapsulated Nuclear Heat Source (ENHS) which are based predominantly on the flow generated by natural convection effects demands knowledge of velocity and temperature fields, distribution of the local Nusselt numbers and values of the average Nusselt numbers for small coolant velocity regimes. Laminar natural convection in rectangular enclosures with different aspect ratios, containing lead-bismuth and lead is studied numerically in this paper. The numerical model takes into account variable properties of the liquid metals. The developed correlation for average Nusselt numbers is presented. It is concluded that average Nusselt numbers are lower than in 'normal' fluids (air, water and glycerol) for the same values of Rayleigh numbers. However, the heat flux, which can be achieved, is greater due to the high thermal conductivity of liquid metals. Some specific features of the flow fields generated by natural convection in liquid metals are presented. Their consequences on the design of heat exchangers for liquid metals are discussed. An application of the obtained results to the design of a new type of steam generator, which integrates the intermediate heat exchanger and secondary pool functions of the ENHS reactor, is presented. (authors)

  12. Properties of three-body decay functions derived with time-like jet calculus beyond leading order

    International Nuclear Information System (INIS)

    Sugiura, Tetsuya

    2002-01-01

    Three-body decay functions in time-like parton branching are calculated using the jet calculus to the next-to-leading logarithmic (NLL) order in perturbative quantum chromodynamics (QCD). The phase space contributions from each of the ladder diagrams and interference diagrams are presented. We correct part of the results for the three-body decay functions calculated previously by two groups. Employing our new results, the properties of the three-body decay functions in the regions of soft partons are examined numerically. Furthermore, we examine the contribution of the three-body decay functions modified by the restriction resulting from the kinematical boundary of the phase space for two-body decay in the parton shower model. This restriction leads to some problems for the parton shower model. For this reason, we propose a new restriction introduced by the kinematical boundary of the phase space for two-body decay. (author)

  13. Overview of Milestone E activities, greater confinement than shallow land burial

    International Nuclear Information System (INIS)

    Mezga, L.J.

    1981-01-01

    In summary, the objective of Milestone E is to provide the technology and documentation needed to open a site providing greater confinement than shallow land burial. To that end, ORNL has prepared a technical position paper defining greater confinement disposal, options for achieving it, and the need for this disposal technology. In order to meet the objective of the milestones, the LLWMP evaluated the full range of options to shallow land burial and decided to focus on a combination of greater depth solidification containment and engineered barriers. The program identified a series of research needs and then focused program efforts on resolving those needs. These tasks are proceeding on schedule at this time but budget reductions may have an impact on our ability to maintain the schedule

  14. Epidemiological aspects of centipede (Scolopendromorphae: Chilopoda bites registered in Greater S. Paulo, SP, Brazil

    Directory of Open Access Journals (Sweden)

    Irene Knysak

    1998-12-01

    Full Text Available INTRODUCTION: The lack of basic knowledge on venomous arthropods and the benignity of the clinical manifestations contribute to the centipede bite victims' not being taken to a treatment reference center, leading to underestimation of the number of cases and minimizing the possibility of a broader epidemiological view. An inventory of the centipede bite occurrences in Greater S. Paulo, Brazil, and the therapeutic methods employed, by the main Brazilian medical center for the notification of poisoning by venomous animals, is presented. METHOD: All patient cards of the period 1980-1989 have been checked as to place, month and time of occurrence; sex, age, affected part of the body, signs and symptoms have been observed, as well as the therapeutic methods employed. The centipedes that caused the accidents were identified at the Arthropods Laboratory. RESULTS: It was registered 216 accidents, with a 69% predominance of the Greater S. Paulo and in only 63% of the cases (136 was the agent brought in by the victim for identification. The genera most frequently represented were Cryptops (58%, Otostigmus (33% and Scolopendra (4%. Of the 136 cases, 87% showed erythema, edema, hemorrhage, burns, cephalalgia, and intense pain. There was a predominance of accidents in the warm rainy season, in the morning and for females between 21 and 60 years of age. Hands and feet were the parts of the body most affected. The benign evolution of the clinical picture (54% made therapeutical treatment unnecessary. Only the victims of Scolopendra and Otostigmus (46% were medicated with anesthetics (51%, analgesics (25%, antihistamines and cortisone (24%. CONCLUSION: The reproductive period of the centipedes, associated with their sinanthropic habits, contributes to the greater incidence of accidents in urban areas in the warm rainy season. Only patients bitten by Scolopendra and Otostigmus require therapeutical treatment.

  15. Performance and exposure indices of rats exposed to low concentrations of lead.

    Science.gov (United States)

    Cory-Slechta, D A; Weiss, B; Cox, C

    1985-04-01

    To further characterize the lower end of the function relating lead exposure and biological exposure indices to behavior, male weanling rats were exposed chronically to drinking solutions containing 25 ppm sodium acetate (controls) or 25 ppm lead acetate. Behavioral training began when the animals reached 50 days of age, and performance on a fixed-interval 1-min schedule of food reinforcement was then assessed over 90 experimental sessions (136 days). This exposure produced overall response rate increases over the first 40 sessions that were similar to those observed previously with higher concentrations of lead. Response rates of the two groups tended to merge subsequently. The increased overall response rates in the treated group derived primarily from an increased frequency of shorter interresponse times (IRTs) and increased running rates (calculated without the postreinforcement interval). Blood lead (PbB) and zinc protoporphyrin (ZPP) values were determined following sessions 30, 60, and 90. PbB values of the lead-exposed group averaged 15 to 20 micrograms/dl throughout the study; ZPP did not differ. The mean brain lead value of the treated group was 0.07 micrograms Pb/g. Blood-brain ratios (1.38 to 4.06) were substantially greater than those previously observed at higher exposures. These data extend to even lower exposures, and lower blood lead concentrations, the effective concentration for behavioral effects, and further emphasize the importance of the sensitivity of the endpoint in assessing behavioral toxicity.

  16. Metabolism of lead-210 in juvenile and adult rhesus monkeys (Macaca mulatta)

    International Nuclear Information System (INIS)

    Pounds, J.G.; Marlar, R.J.; Allen, J.R.

    1978-01-01

    Experiments were conducted measuring the gastrointestinal absorption and elimination of a single dose of lead-210 acetate in infant and adult rhesus monkeys. Urinary and fecal excretion of absorbed lead was followed for 23 days. Infant monkeys eliminated less and absorbed more orally administered lead. Adult animals excreted more absorbed lead in feces, while urinary excretion between adults and infants was similar. Increased absorption of administered lead and reduced fecal excretion of absorbed lead resulted in significantly greater body burden of lead-210 in infant animals. Blood lead values were increased in the infant animals, and were inversely correlated with body burden and percent absorption of ingested lead

  17. Extracting Leading Nonlinear Modes of Changing Climate From Global SST Time Series

    Science.gov (United States)

    Mukhin, D.; Gavrilov, A.; Loskutov, E. M.; Feigin, A. M.; Kurths, J.

    2017-12-01

    Data-driven modeling of climate requires adequate principal variables extracted from observed high-dimensional data. For constructing such variables it is needed to find spatial-temporal patterns explaining a substantial part of the variability and comprising all dynamically related time series from the data. The difficulties of this task rise from the nonlinearity and non-stationarity of the climate dynamical system. The nonlinearity leads to insufficiency of linear methods of data decomposition for separating different processes entangled in the observed time series. On the other hand, various forcings, both anthropogenic and natural, make the dynamics non-stationary, and we should be able to describe the response of the system to such forcings in order to separate the modes explaining the internal variability. The method we present is aimed to overcome both these problems. The method is based on the Nonlinear Dynamical Mode (NDM) decomposition [1,2], but takes into account external forcing signals. An each mode depends on hidden, unknown a priori, time series which, together with external forcing time series, are mapped onto data space. Finding both the hidden signals and the mapping allows us to study the evolution of the modes' structure in changing external conditions and to compare the roles of the internal variability and forcing in the observed behavior. The method is used for extracting of the principal modes of SST variability on inter-annual and multidecadal time scales accounting the external forcings such as CO2, variations of the solar activity and volcanic activity. The structure of the revealed teleconnection patterns as well as their forecast under different CO2 emission scenarios are discussed.[1] Mukhin, D., Gavrilov, A., Feigin, A., Loskutov, E., & Kurths, J. (2015). Principal nonlinear dynamical modes of climate variability. Scientific Reports, 5, 15510. [2] Gavrilov, A., Mukhin, D., Loskutov, E., Volodin, E., Feigin, A., & Kurths, J. (2016

  18. Estudo do efeito de programas de melhoria contínua em variáveis do chão de fábrica na relação entre tamanho de lote de produção e lead time: lead time relationship Study of the effect of continuous improvement programs on lot size

    Directory of Open Access Journals (Sweden)

    Moacir Godinho Filho

    2010-01-01

    Full Text Available No atual ambiente competitivo, a tomada de decisão tem se tornado uma tarefa cada vez mais complicada, envolvendo inúmeras variáveis, e suas relações, nem sempre claramente entendidas. Uma dessas relações, foco deste artigo, é a relação entre tamanho de lote de produção e lead time médio. Essa relação é amplamente conhecida na literatura específica sobre teoria de filas, porém o mesmo não acontece na prática em gestão de operações. Este artigo trata deste assunto, objetivando apresentar e comparar o efeito de seis programas de melhoria contínua em variáveis do chão de fábrica (variabilidade da chegada das ordens, variabilidade do processo, taxa de defeito, tempo até a falha, tempo de reparo e tempo de set up na relação tamanho de lote × lead time em um ambiente de máquina única que fabrica múltiplos produtos. Isto é feito por meio de uma combinação das abordagens System Dynamics (Forrester, 1962 e Factory Physics (Hopp; Spearman, 2008. Dois conjuntos de experimentos são realizados: i Uma melhoria de grandes proporções (50% em cada uma das variáveis separadamente, como aquela que seria obtida por um grande investimento; ii Uma pequena melhoria em todas as variáveis simultaneamente. Os resultados mostraram: (a o efeito positivo de programas de melhoria contínua em variáveis do chão de fábrica no lead time; (b a importância de se conhecer a curva tamanho de lote × lead time e o papel da redução de set up antes de se iniciarem programas de redução de tamanhos de lote; (c que investir em pequenas melhorias em muitas variáveis de forma simultânea é uma política melhor, com relação ao lead time, do que realizar uma grande melhoria em somente uma variável; (d algumas contribuições para um melhor entendimento de modernos paradigmas de gestão da produção, tais como Lean Manufaturing e Quick Response Manufacturing.Many modern manufacturing management approaches present relationships between

  19. High-temperature superconducting current leads

    Science.gov (United States)

    Hull, J. R.

    1992-07-01

    The use of high-temperature superconductors (HTSs) for current leads to deliver power to devices at liquid helium temperature is near commercial realization. The use of HTSs in this application has the potential to reduce refrigeration requirements and helium boiloff to values significantly lower than the theoretical best achievable with conventional leads. Considerable advantage is achieved by operating these leads with an intermediate temperature heat sink. The HTS part of the lead can be made from pressed and sintered powder. Powder-in-tube fabrication is also possible, however, the normal metal part of the lead acts as a thermal short and cannot provide much stabilization without increasing the refrigeration required. Lead stability favors designs with low current density. Such leads can be manufactured with today's technology, and lower refrigeration results from the same allowable burnout time. Higher current densities result in lower boiloff for the same lead length, but bumout times can be very short. In comparing experiment to theory, the density of helium vapor needs to be accounted for in calculating the expected boiloff. For very low-loss leads, two-dimensional heat transfer and the state of the dewar near the leads may play a dominant role in lead performance.

  20. Ingestion of lead from ammunition and lead concentrations in white-tailed sea eagles (Haliaeetus albicilla) in Sweden

    International Nuclear Information System (INIS)

    Helander, B.; Axelsson, J.; Borg, H.; Holm, K.; Bignert, A.

    2009-01-01

    In this study we show for the first time that lead poisoning from ammunition is a significant mortality factor for white-tailed sea eagle (WSE) (Haliaeetus albicilla) in Sweden. We analyzed 118 WSEs collected between 1981 and 2004 from which both liver and kidney samples could be taken. A total of 22% of all eagles examined had elevated (> 6 μg/g d.w.) lead concentrations, indicating exposure to leaded ammunition, and 14% of the individuals had either liver or kidney lead concentrations diagnostic of lethal lead poisoning (> 20 μg/g d.w.). Lead concentrations in liver and kidney were significantly correlated. In individuals with lead levels 20 μg/g, concentrations were significantly higher in liver. The lead isotope ratios indicate that the source of lead in individuals with lethal concentrations is different from that of individuals exhibiting background concentrations of lead ( 10 times higher than concentrations reported for Baltic fish from the same time period. In contrast to other biota there was no decrease in lead concentrations in WSE over the study period. The proportion of lead poisoned WSE remained unchanged over the study period, including two years after a partial ban of lead shot was enforced in 2002 for shallow wetlands. The use of lead in ammunition poses a threat to all raptors potentially feeding on shot game or offal. The removal of offal from shot game and alternatives to leaded ammunition needs to be implemented in order to prevent mortality from lead in raptors and scavengers.

  1. Interpretations of systematic errors in the NCEP Climate Forecast System at lead times of 2, 4, 8, ..., 256 days

    Directory of Open Access Journals (Sweden)

    Siwon Song

    2012-09-01

    Full Text Available The climatology of mean bias errors (relative to 1-day forecasts was examined in a 20-year hindcast set from version 1 of the Climate Forecast System (CFS, for forecast lead times of 2, 4, 8, 16, ... 256 days, verifying in different seasons. Results mostly confirm the simple expectation that atmospheric model biases should be evident at short lead (2–4 days, while soil moisture errors develop over days-weeks and ocean errors emerge over months. A further simplification is also evident: surface temperature bias patterns have nearly fixed geographical structure, growing with different time scales over land and ocean. The geographical pattern has mostly warm and dry biases over land and cool bias over the oceans, with two main exceptions: (1 deficient stratocumulus clouds cause warm biases in eastern subtropical oceans, and (2 high latitude land is too cold in boreal winter. Further study of the east Pacific cold tongue-Intertropical Convergence Zone (ITCZ complex shows a possible interaction between a rapidly-expressed atmospheric model bias (poleward shift of deep convection beginning at day 2 and slow ocean dynamics (erroneously cold upwelling along the equator in leads > 1 month. Further study of the high latitude land cold bias shows that it is a thermal wind balance aspect of the deep polar vortex, not just a near-surface temperature error under the wintertime inversion, suggesting that its development time scale of weeks to months may involve long timescale processes in the atmosphere, not necessarily in the land model. Winter zonal wind errors are small in magnitude, but a refractive index map shows that this can cause modest errors in Rossby wave ducting. Finally, as a counterpoint to our initial expectations about error growth, a case of non-monotonic error growth is shown: velocity potential bias grows with lead on a time scale of weeks, then decays over months. It is hypothesized that compensations between land and ocean errors may

  2. Greater-confinement disposal

    International Nuclear Information System (INIS)

    Trevorrow, L.E.; Schubert, J.P.

    1989-01-01

    Greater-confinement disposal (GCD) is a general term for low-level waste (LLW) disposal technologies that employ natural and/or engineered barriers and provide a degree of confinement greater than that of shallow-land burial (SLB) but possibly less than that of a geologic repository. Thus GCD is associated with lower risk/hazard ratios than SLB. Although any number of disposal technologies might satisfy the definition of GCD, eight have been selected for consideration in this discussion. These technologies include: (1) earth-covered tumuli, (2) concrete structures, both above and below grade, (3) deep trenches, (4) augered shafts, (5) rock cavities, (6) abandoned mines, (7) high-integrity containers, and (8) hydrofracture. Each of these technologies employ several operations that are mature,however, some are at more advanced stages of development and demonstration than others. Each is defined and further described by information on design, advantages and disadvantages, special equipment requirements, and characteristic operations such as construction, waste emplacement, and closure

  3. The leaching of lead from lead-based paint in landfill environments.

    Science.gov (United States)

    Wadanambi, Lakmini; Dubey, Brajesh; Townsend, Timothy

    2008-08-30

    Lead leaching from lead-based paint (LBP) was examined using standardized laboratory protocols and tests with leachate from actual and simulated landfill environments. Two different LBP samples were tested; leaching solutions included leachates from three municipal solid waste (MSW) landfills and three construction and demolition (C&D) debris landfills. The toxicity characteristic leaching procedure (TCLP) and the synthetic precipitation leaching procedure (SPLP) were also performed. Lead concentrations were many times higher using the TCLP compared to the SPLP and the landfill leachates. No significant difference (alpha=0.05) was observed in leached lead concentrations from the MSW landfill and C&D debris landfill leachates. The impact of other building materials present in LBP debris on lead leaching was examined by testing mixtures of LBP (2%) and different building materials (98%; steel, wood, drywall, concrete). The type of substrate present impacted lead leaching results, with concrete demonstrating the most dramatic impact; the lowest lead concentrations were measured in the presence of concrete under both TCLP and SPLP extractions.

  4. Real-Time Salmonella Detection Using Lead Zirconate Titanate-Titanium Microcantilevers

    National Research Council Canada - National Science Library

    McGovern, John-Paul; Shih, Wan Y; Shih, Wei-Heng; Sergi, Mauro; Chaiken, Irwin

    2005-01-01

    .... We have developed and investigated the use of a lead zirconate titanate - titanium (PZT-Ti) microcantilever for in situ detection of the common food- and water-born pathogen, Salmonella typhimurium...

  5. Estimate of overdiagnosis of breast cancer due to mammography after adjustment for lead time. A service screening study in Italy

    Science.gov (United States)

    Paci, Eugenio; Miccinesi, Guido; Puliti, Donella; Baldazzi, Paola; De Lisi, Vincenzo; Falcini, Fabio; Cirilli, Claudia; Ferretti, Stefano; Mangone, Lucia; Finarelli, Alba Carola; Rosso, Stefano; Segnan, Nereo; Stracci, Fabrizio; Traina, Adele; Tumino, Rosario; Zorzi, Manuel

    2006-01-01

    Introduction Excess of incidence rates is the expected consequence of service screening. The aim of this paper is to estimate the quota attributable to overdiagnosis in the breast cancer screening programmes in Northern and Central Italy. Methods All patients with breast cancer diagnosed between 50 and 74 years who were resident in screening areas in the six years before and five years after the start of the screening programme were included. We calculated a corrected-for-lead-time number of observed cases for each calendar year. The number of observed incident cases was reduced by the number of screen-detected cases in that year and incremented by the estimated number of screen-detected cases that would have arisen clinically in that year. Results In total we included 13,519 and 13,999 breast cancer cases diagnosed in the pre-screening and screening years, respectively. In total, the excess ratio of observed to predicted in situ and invasive cases was 36.2%. After correction for lead time the excess ratio was 4.6% (95% confidence interval 2 to 7%) and for invasive cases only it was 3.2% (95% confidence interval 1 to 6%). Conclusion The remaining excess of cancers after individual correction for lead time was lower than 5%. PMID:17147789

  6. Criteria and technical concept for demonstrating greater confinement disposal of radioactive wastes at Arid Western Sites

    International Nuclear Information System (INIS)

    Hunter, P.H.

    1981-01-01

    This report summarizes the work of two documents; the Criteria for Greater Confinement of Radioactive Wastes at Arid Western Sites, NVO-234, March 1981, (within this report, referred to as the GCDF Criteria Document); and the Draft Technical Concept for a Test of Greater Confinement Disposal of Radioactive Waste in Unsaturated Media at the Nevada Test Site, FBDU-343-004, June 1981, (referred within this report as the Technical Concept for the GCDF). For the past two years, Ford, Bacon and Davis has been performing technical services for the Department of Energy at the Nevada Test Site in development of defense low-level waste management concepts, including the greater confinement disposal concept with particular application to arid sites. The investigations have included the development of Criteria for Greater Confinement Disposal, NVO-234, which we published in May of this year; then the draft for the technical concept for greater confinement disposal, published in June; leading up to the point where we are now. The final technical concept and design specifications should be published imminently. The document is prerequisite to the actual construction and implementation of the demonstration facility this fiscal year

  7. Use of renewable energy in the greater metropolitan area

    International Nuclear Information System (INIS)

    Arias Garcia, Rocio; Castro Gomez, Gustavo; Fallas Cordero, Kenneth; Grant Chaves, Samuel; Mendez Parrales, Tony; Parajeles Fernandez, Ivan

    2012-01-01

    A study is conducted on different renewable energy within the larger metropolitan area, selecting the most suitable for the area and the implementation for distributed generation. A research methodology is practiced type pretending gather the necessary information to make proposals selected of different type of energy. The geography of the greater metropolitan area is studied along with the different existing renewable energy: distributed generation, remote measurement of energy which is one of the elements of the concept of intelligent networks (Smart Grid) in the electricity sector, legislation of Costa Rica regarding the generation of renewable energy and environmental impact. An analysis of economic feasibility is covered for each of the proposals estimating current rates for leading distributors of a future value, concluding with the viability of projects for possible execution of the same. (author) [es

  8. Community blood lead survey with emphasis on preschool children following lead dust pollution in Esperance, Western Australia.

    Science.gov (United States)

    Rossi, Enrico; McLaughlin, Virginia; Joseph, John; Bulsara, Max; Coleman, Kerryn; Douglas, Charles; Robertson, Andrew

    2012-04-01

    To assess the impact of airborne lead dust on blood lead levels in residents of Esperance, a regional Western Australian town, with particular reference to preschool children. Following identification of significant airborne lead contamination, residents were notified that a blood lead clinic was available to all, with testing of preschool children encouraged. About 40% (333 children) of the preschool group and about 20% of the remaining population were tested. The main measures were blood lead levels, prevalence of elevated results and comparisons to other Western Australian surveys. In preschoolers, 2.1% (seven children) had blood lead levels exceeding the current 10 μg/dL level of concern. This was not significantly different to two previous community-based surveys elsewhere in Western Australia. However, at a lower cut-off of 5 μg/dL, the prevalence of elevated lead levels was 24.6%, significantly higher than children tested in a previous Western Australian survey. The prevalence of blood lead levels of 10 μg/dL or greater in adults was 1.3% (26 adults), not significantly different from a previous Western Australian survey. The prevalence of preschool children with blood lead levels exceeding the current level of concern was not significantly increased. However, the increased prevalence of children with lead levels at or above 5 μg/dL demonstrates exposure to lead dust pollution. This episode of lead dust contamination highlights the need for strict adherence to environmental controls and effective monitoring processes to ensure the prevention of future events. © 2012 The Authors. ANZJPH © 2012 Public Health Association of Australia.

  9. Methodology for the technical evaluation of disposal systems for Greater-Than-Class C low-level radioactive waste

    International Nuclear Information System (INIS)

    Lamar, D.A.; Raymond, J.R.

    1990-07-01

    This paper presents the methodology that will be used for the evaluation of alternative disposal concepts for Greater-Than-Class C low-level radioactive waste. The primary focus will be on the technical evaluation of various disposal concepts leading toward the identification of technically feasible disposal systems

  10. Occurrence and determinants of increases in blood lead levels in children shortly after lead hazard control activities

    International Nuclear Information System (INIS)

    Clark, Scott; Grote, JoAnn; Wilson, Jonathan; Succop, Paul; Chen Mei; Galke, Warren; McLaine, Pat

    2004-01-01

    This study is an examination of the effect of lead hazard control strategies on children's blood lead levels immediately after an intervention was conducted as part of the US Department of Housing and Urban Development's Lead-Based Paint Hazard Control Grant Program. Fourteen state and local government grantees participated in the evaluation. The findings indicated an overall average reduction in the blood lead levels of 869 children soon after the implementation of lead hazard controls. However, 9.3% of these children (n=81) had blood lead increases of 5 μg/dL or more. Data routinely collected as part of the evaluation, as well as additional information supplied by the individual programs, were used to determine potential reasons for these observed increases in blood lead. A logistic regression analysis indicated that three principal factors were associated with the blood lead increases: the number of exterior deteriorations present in the child's home (prior to intervention), the educational level of the female parent or guardian of the child, and the child's age. The statistical analysis did not find evidence that children living in households that either did not relocate or relocated for less than the full work period were significantly more likely to have a blood lead increase equal to or greater than 5 μg/dL than children living in households that fully relocated. Statistical analyses also did not reveal any single interior strategy to be more or less likely than others to be associated with a blood lead increase of 5 μg/dL or more

  11. Sensitivity of in vivo X-ray fluorescence determination of skeletal lead stores

    International Nuclear Information System (INIS)

    Sokas, R.K.; Besarab, A.; McDiarmid, M.A.; Shapiro, I.M.; Bloch, P.

    1990-01-01

    Eighteen patients with known past occupational lead exposure underwent parenteral diagnostic chelation with ethylenediaminetetraacetic acid and x-ray fluorescent determination of in vivo skeletal lead stores at the distal styloid process of the ulna and at the temporal base bone using a cobalt 57 source and measuring lead Ka x-rays. X-ray fluorescent lead measurements in both locations correlated with results of diagnostic chelation. Using a post-chelation urinary excretion of greater than 600 micrograms lead/24 h as the definition of high-lead stores, sensitivity of x-ray fluorescence at the wrist and temple was 56% and 39%, respectively

  12. Effect measure modification of blood lead-air lead slope factors.

    Science.gov (United States)

    Richmond-Bryant, Jennifer; Meng, Qingyu; Cohen, Jonathan; Davis, J Allen; Svendsgaard, David; Brown, James S; Tuttle, Lauren; Hubbard, Heidi; Rice, Joann; Kirrane, Ellen; Vinikoor-Imler, Lisa; Kotchmar, Dennis; Hines, Erin; Ross, Mary

    2015-01-01

    There is abundant literature finding that susceptibility factors, including race and ethnicity, age, and housing, directly influence blood lead levels. No study has explored how susceptibility factors influence the blood lead-air lead relationship nationally. The objective is to evaluate whether susceptibility factors act as effect measure modifiers on the blood lead-air lead relationship. Participant level blood lead data from the 1999 to 2008 National Health and Nutrition Examination Survey were merged with air lead data from the US Environmental Protection Agency. Linear mixed effects models were run with and without an air lead interaction term for age group, sex, housing age, or race/ethnicity to determine whether these factors are effect measure modifiers for all ages combined and for five age brackets. Age group and race/ethnicity were determined to be effect measure modifiers in the all-age model and for some age groups. Being a child (1-5, 6-11, and 12-19 years) or of Mexican-American ethnicity increased the effect estimate. Living in older housing (built before 1950) decreased the effect estimate for all models except for the 1-5-year group, where older housing was an effect measure modifier. These results are consistent with the peer-reviewed literature of time-activity patterns, ventilation, and toxicokinetics.

  13. Real-Time 12-Lead High-Frequency QRS Electrocardiography for Enhanced Detection of Myocardial Ischemia and Coronary Artery Disease

    Science.gov (United States)

    Schlegel, Todd T.; Kulecz, Walter B.; DePalma, Jude L.; Feiveson, Alan H.; Wilson, John S.; Rahman, M. Atiar; Bungo, Michael W.

    2004-01-01

    Several studies have shown that diminution of the high-frequency (HF; 150-250 Hz) components present within the central portion of the QRS complex of an electrocardiogram (ECG) is a more sensitive indicator for the presence of myocardial ischemia than are changes in the ST segments of the conventional low-frequency ECG. However, until now, no device has been capable of displaying, in real time on a beat-to-beat basis, changes in these HF QRS ECG components in a continuously monitored patient. Although several software programs have been designed to acquire the HF components over the entire QRS interval, such programs have involved laborious off-line calculations and postprocessing, limiting their clinical utility. We describe a personal computer-based ECG software program developed recently at the National Aeronautics and Space Administration (NASA) that acquires, analyzes, and displays HF QRS components in each of the 12 conventional ECG leads in real time. The system also updates these signals and their related derived parameters in real time on a beat-to-beat basis for any chosen monitoring period and simultaneously displays the diagnostic information from the conventional (low-frequency) 12-lead ECG. The real-time NASA HF QRS ECG software is being evaluated currently in multiple clinical settings in North America. We describe its potential usefulness in the diagnosis of myocardial ischemia and coronary artery disease.

  14. Optical Time Reversal from Time-Dependent Epsilon-Near-Zero Media

    Science.gov (United States)

    Vezzoli, Stefano; Bruno, Vincenzo; DeVault, Clayton; Roger, Thomas; Shalaev, Vladimir M.; Boltasseva, Alexandra; Ferrera, Marcello; Clerici, Matteo; Dubietis, Audrius; Faccio, Daniele

    2018-01-01

    Materials with a spatially uniform but temporally varying optical response have applications ranging from magnetic field-free optical isolators to fundamental studies of quantum field theories. However, these effects typically become relevant only for time variations oscillating at optical frequencies, thus presenting a significant hurdle that severely limits the realization of such conditions. Here we present a thin-film material with a permittivity that pulsates (uniformly in space) at optical frequencies and realizes a time-reversing medium of the form originally proposed by Pendry [Science 322, 71 (2008), 10.1126/science.1162087]. We use an optically pumped, 500 nm thick film of epsilon-near-zero (ENZ) material based on Al-doped zinc oxide. An incident probe beam is both negatively refracted and time reversed through a reflected phase-conjugated beam. As a result of the high nonlinearity and the refractive index that is close to zero, the ENZ film leads to time reversed beams (simultaneous negative refraction and phase conjugation) with near-unit efficiency and greater-than-unit internal conversion efficiency. The ENZ platform therefore presents the time-reversal features required, e.g., for efficient subwavelength imaging, all-optical isolators and fundamental quantum field theory studies.

  15. Simultaneous bilateral isolated greater trochanter fracture

    Directory of Open Access Journals (Sweden)

    Maruti Kambali

    2013-01-01

    Full Text Available A 48-year-old woman sustained simultaneous isolated bilateral greater trochanteric fracture, following a road traffic accident. The patient presented to us 1 month after the injury. She presented with complaints of pain in the left hip and inability to walk. Roentgenograms revealed displaced comminuted bilateral greater trochanter fractures. The fracture of the left greater trochanter was reduced and fixed internally using the tension band wiring technique. The greater trochanter fracture on the right side was asymptomatic and was managed conservatively. The patient regained full range of motion and use of her hips after a postoperative follow-up of 6 months. Isolated fractures of the greater trochanter are unusual injuries. Because of their relative rarity and the unsettled controversy regarding their etiology and pathogenesis, several methods of treatment have been advocated. Furthermore, the reports of this particular type of injury are not plentiful and the average textbook coverage afforded to this entity is limited. In our study we discuss the mechanism of injury and the various treatment options available.

  16. How does development lead time affect performance over the ramp-up lifecycle? : evidence from the consumer electronics industry

    NARCIS (Netherlands)

    Pufall, A.A.; Fransoo, J.C.; Jong, de A.; Kok, de A.G.

    2012-01-01

    In the fast-paced world of consumer electronics, short development lead times and efficient product ramp-ups are invaluable. The sooner and faster a firm can ramp-up production of a new product, the faster it can start to earn revenues, profit from early market opportunities, establish technology

  17. Velocity Drives Greater Power Observed During Back Squat Using Cluster Sets.

    Science.gov (United States)

    Oliver, Jonathan M; Kreutzer, Andreas; Jenke, Shane C; Phillips, Melody D; Mitchell, Joel B; Jones, Margaret T

    2016-01-01

    This investigation compared the kinetics and kinematics of cluster sets (CLU) and traditional sets (TRD) during back squat in trained (RT) and untrained (UT) men. Twenty-four participants (RT = 12, 25 ± 1 year, 179.1 ± 2.2 cm, 84.6 ± 2.1 kg; UT = 12, 25 ± 1 year, 180.1 ± 1.8 cm, 85.4 ± 3.8 kg) performed TRD (4 × 10, 120-second rest) and CLU (4 × (2 × 5) 30 seconds between clusters; 90 seconds between sets) with 70% one repetition maximum, randomly. Kinematics and kinetics were sampled through force plate and linear position transducers. Resistance-trained produced greater overall force, velocity, and power; however, similar patterns were observed in all variables when comparing conditions. Cluster sets produced significantly greater force in isolated repetitions in sets 1-3, while consistently producing greater force due to a required reduction in load during set 4 resulting in greater total volume load (CLU, 3302.4 ± 102.7 kg; TRD, 3274.8 ± 102.8 kg). Velocity loss was lessened in CLU resulting in significantly higher velocities in sets 2 through 4. Furthermore, higher velocities were produced by CLU during later repetitions of each set. Cluster sets produced greater power output for an increasing number of repetitions in each set (set 1, 5 repetitions; sets 2 and 3, 6 repetitions; set 4, 8 repetitions), and the difference between conditions increased over subsequent sets. Time under tension increased over each set and was greater in TRD. This study demonstrates greater power output is driven by greater velocity when back squatting during CLU; therefore, velocity may be a useful measure by which to assess power.

  18. Lead in the environment

    Science.gov (United States)

    Pattee, Oliver H.; Pain, Deborah J.; Hoffman, David J.; Rattner, Barnett A.; Burton, G. Allen; Cairns, John

    2003-01-01

    Anthropogenic uses of lead have probably altered its availability and environmental distribution more than any other toxic element. Consequently, lead concentrations in many living organisms may be approaching thresholds of toxicity for the adverse effects of lead. Such thresholds are difficult to define, as they vary with the chemical and physical form of lead, exposure regime, other elements present and also vary both within and between species. The technological capability to accurately quantify low lead concentrations has increased over the last decade, and physiological and behavioral effects have been measured in wildlife with tissue lead concentrations below those previously considered safe for humans.s.236 Consequently. lead criteria for the protection of wildlife and human health are frequently under review, and 'thresholds' of lead toxicity are being reconsidered. Proposed lead criteria for the protection of natural resources have been reviewed by Eisler. Uptake of lead by plants is limited by its generally low availability in soils and sediments, and toxicity may be limited by storage mechanisms and its apparently limited translocation within most plants. Lead does not generally accumulate within the foliar parts of plants, which limits its transfer to higher trophic levels. Although lead may concentrate in plant and animal tissues, no evidence of biomagnification exists. Acid deposition onto surface waters and soils with low buffering capacity may influence the availability of lead for uptake by plants and animals, and this may merit investigation at susceptible sites. The biological significance of chronic low-level lead exposure to wildlife is sometimes difficult to quantify. Animals living in urban environments or near point sources of lead emission are inevitably subject to greater exposure to lead and enhanced risk of lead poisoning. Increasingly strict controls on lead emissions in many countries have reduced exposure to lead from some sources

  19. Eryptosis in lead-exposed workers.

    Science.gov (United States)

    Aguilar-Dorado, Itzel-Citlalli; Hernández, Gerardo; Quintanar-Escorza, Martha-Angelica; Maldonado-Vega, María; Rosas-Flores, Margarita; Calderón-Salinas, José-Víctor

    2014-12-01

    Eryptosis is a physiological phenomenon in which old and damaged erythrocytes are removed from circulation. Erythrocytes incubated with lead have exhibited major eryptosis. In the present work we found evidence of high levels of eryptosis in lead exposed workers possibly via oxidation. Blood samples were taken from 40 male workers exposed to lead (mean blood lead concentration 64.8μg/dl) and non-exposed workers (4.2μg/dl). The exposure to lead produced an intoxication characterized by 88.3% less δ-aminolevulinic acid dehydratase (δALAD) activity in lead exposed workers with respect to non-lead exposed workers. An increment of oxidation in lead exposed workers was characterized by 2.4 times higher thiobarbituric acid-reactive substance (TBARS) concentration and 32.8% lower reduced/oxidized glutathione (GSH/GSSG) ratio. Oxidative stress in erythrocytes of lead exposed workers is expressed in 192% higher free calcium concentration [Ca(2+)]i and 1.6 times higher μ-calpain activity with respect to non-lead exposed workers. The adenosine triphosphate (ATP) concentration was not significantly different between the two worker groups. No externalization of phosphatidylserine (PS) was found in non-lead exposed workers (lead exposed workers showed 2.82% externalization. Lead intoxication induces eryptosis possibly through a molecular pathway that includes oxidation, depletion of reduced glutathione (GSH), increment of [Ca(2+)], μ-calpain activation and externalization of PS in erythrocytes. Identifying molecular signals that induce eryptosis in lead intoxication is necessary to understand its physiopathology and chronic complications. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Leading Baryon Production at HERA

    International Nuclear Information System (INIS)

    Dodonov, V.; Schmitt, S.

    2009-01-01

    The production of highly energetic forward neutrons has been studied in deep-inelastic scattering. The data were taken with the H1 detector at HERA in the years 2006-2007 and correspond to an integrated luminosity of 117 pb -1 . Semi-inclusive cross sections have been measured in the kinematic region 4 2 2 , 0.7*10 -4 -1 and the fractional momentum of the neutron 0.3 L T and compared to the predictions of models of leading neutron production. Differential cross sections for dijet photoproduction and in association with a leading neutron have been measured in the reaction e + p → e + jet jet X n with the ZEUS detector at HERA using an integrated luminosity of 40pb -1 . The data are consistent with a simple pion exchange model. The ratio of the neutron-tagged and dijet cross sections show violations of factorization of the lepton and photon vertices which can be explained by kinematic effects constraining the phase space for neutron production. Normalised double-differential leading-neutron cross sections have been measured in dijet photoproduction for the first time. The distributions can be fully characterised by only two energy dependent parameters extracted from fits to the data. Absorption effects were studied by comparing the dijet photoproduction measurements and similar results in deep inelastic scattering. No clear effect, not related to kinematics, was observed. In a resolved-enriched dijet photoproduction sample, significantly fewer neutrons were seen than for direct. This depletion can also be accounted for by kinematic constraints. The semi-inclusive reaction e + p → e + X p was studied with the ZEUS detector at HERA using an integrated luminosity of 12.8 pb -1 . The final state proton, which was detected with the ZEUS leading proton spectrometer, carried a large fraction of the incoming proton energy, x L > 0.32, and its transverse momentum squared satisfied p T 2 2 ; the exchanged photon virtuality, Q 2 , was greater than 3 GeV 2 and the range of

  1. Ingestion of lead from ammunition and lead concentrations in white-tailed sea eagles (Haliaeetus albicilla) in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Helander, B., E-mail: bjorn.helander@nrm.se [Department of Contaminant Research, Swedish Museum of Natural History, Box 50007, SE-104 05 Stockholm (Sweden); Axelsson, J., E-mail: jeanette.axelsson@hgen.slu.se [Department of Environmental Toxicology, Evolutionary Biology Centre, Uppsala University, SE-752 36 Uppsala (Sweden); Borg, H., E-mail: hans.borg@itm.su.se [Department of Applied Environmental Science/ITM, Stockholm University, SE-106 91 Stockholm (Sweden); Holm, K. [Department of Applied Environmental Science/ITM, Stockholm University, SE-106 91 Stockholm (Sweden); Bignert, A., E-mail: anders.bignert@nrm.se [Department of Contaminant Research, Swedish Museum of Natural History, Box 50007, SE-104 05 Stockholm (Sweden)

    2009-10-15

    In this study we show for the first time that lead poisoning from ammunition is a significant mortality factor for white-tailed sea eagle (WSE) (Haliaeetus albicilla) in Sweden. We analyzed 118 WSEs collected between 1981 and 2004 from which both liver and kidney samples could be taken. A total of 22% of all eagles examined had elevated (> 6 {mu}g/g d.w.) lead concentrations, indicating exposure to leaded ammunition, and 14% of the individuals had either liver or kidney lead concentrations diagnostic of lethal lead poisoning (> 20 {mu}g/g d.w.). Lead concentrations in liver and kidney were significantly correlated. In individuals with lead levels < 6 {mu}g/g, concentrations were significantly higher in kidney than in liver; in individuals with lead levels > 20 {mu}g/g, concentrations were significantly higher in liver. The lead isotope ratios indicate that the source of lead in individuals with lethal concentrations is different from that of individuals exhibiting background concentrations of lead (< 6 {mu}g/g d.w.) There were no significant sex or age differences in lead concentrations. A study from the Baltic reported in principle no biomagnification of lead, but background lead concentrations in WSE liver in this study were still four to > 10 times higher than concentrations reported for Baltic fish from the same time period. In contrast to other biota there was no decrease in lead concentrations in WSE over the study period. The proportion of lead poisoned WSE remained unchanged over the study period, including two years after a partial ban of lead shot was enforced in 2002 for shallow wetlands. The use of lead in ammunition poses a threat to all raptors potentially feeding on shot game or offal. The removal of offal from shot game and alternatives to leaded ammunition needs to be implemented in order to prevent mortality from lead in raptors and scavengers.

  2. Time course of recovery following resistance training leading or not to failure.

    Science.gov (United States)

    Morán-Navarro, Ricardo; Pérez, Carlos E; Mora-Rodríguez, Ricardo; de la Cruz-Sánchez, Ernesto; González-Badillo, Juan José; Sánchez-Medina, Luis; Pallarés, Jesús G

    2017-12-01

    To describe the acute and delayed time course of recovery following resistance training (RT) protocols differing in the number of repetitions (R) performed in each set (S) out of the maximum possible number (P). Ten resistance-trained men undertook three RT protocols [S × R(P)]: (1) 3 × 5(10), (2) 6 × 5(10), and (3) 3 × 10(10) in the bench press (BP) and full squat (SQ) exercises. Selected mechanical and biochemical variables were assessed at seven time points (from - 12 h to + 72 h post-exercise). Countermovement jump height (CMJ) and movement velocity against the load that elicited a 1 m s -1 mean propulsive velocity (V1) and 75% 1RM in the BP and SQ were used as mechanical indicators of neuromuscular performance. Training to muscle failure in each set [3 × 10(10)], even when compared to completing the same total exercise volume [6 × 5(10)], resulted in a significantly higher acute decline of CMJ and velocity against the V1 and 75% 1RM loads in both BP and SQ. In contrast, recovery from the 3 × 5(10) and 6 × 5(10) protocols was significantly faster between 24 and 48 h post-exercise compared to 3 × 10(10). Markers of acute (ammonia, growth hormone) and delayed (creatine kinase) fatigue showed a markedly different course of recovery between protocols, suggesting that training to failure slows down recovery up to 24-48 h post-exercise. RT leading to failure considerably increases the time needed for the recovery of neuromuscular function and metabolic and hormonal homeostasis. Avoiding failure would allow athletes to be in a better neuromuscular condition to undertake a new training session or competition in a shorter period of time.

  3. Biosorption of lead and copper by heavy-metal tolerant Micrococcus luteus DE2008.

    Science.gov (United States)

    Puyen, Zully M; Villagrasa, Eduard; Maldonado, Juan; Diestra, Elia; Esteve, Isabel; Solé, Antoni

    2012-12-01

    Micrococcus luteus DE2008 has the ability to absorb lead and copper. The effect of these metals on biomass and viability of this microorganism were investigated and removal of the metals from culture media was determined. Lead had no effect on the biomass expressed as mg Carbon/cm(3) of M. Iuteus DE2008, but in the case of copper, the minimum metal concentration that affected the biomass was 0.1 mM Cu(II). According to these results this microorganism shows a greater tolerance for lead. The minimum metal concentration that affected viability (expressed as the percentage of live cells) was 0.5 mM for both metals. M. luteus DE2008 exhibited a specific removal capacity of 408 mg/g for copper and 1965 mg/g for lead. This microorganism has a greater ability to absorb Pb(II) than Cu(II). M. luteus DE2008 could be seen as a microorganism capable of restoring environments polluted by lead and copper. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. CaEDTA vs CaEDTA plus BAL to treat children with elevated blood lead levels.

    Science.gov (United States)

    O'Connor, M E

    1992-07-01

    The effectiveness of CaEDTA alone vs CaEDTA plus BAL was compared retrospectively in a group of 72 children with lead levels between 2.41 mumol/L (50 micrograms/dL) and 2.90 mumol/L (60 micrograms/dL). The children who received both drugs had higher median zinc protoporphyrin (ZnP) concentrations at the initiation of therapy than children who received CaEDTA alone (160 micrograms/dL vs 96 micrograms/dL, p less than .01). There was a significantly increased incidence of vomiting and abnormal liver-function test results in the children who received both drugs. The children who received CaEDTA alone had a greater percent mean fall in lead level at one to three weeks postchelation (30.5% vs 18.1%, p less than .05). Children who received both CaEDTA and BAL had a greater percent decrease in ZnP at four to eight months postchelation, but there was no difference in percent decrease in lead levels. Children who received both drugs also had a greater number of repeat courses of chelation by six months. The addition of BAL to CaEDTA for treatment of children with lead levels of 2.41 mumol/L (50 micrograms/dL) to 2.90 mumol/L (60 micrograms/dL) produced greater toxicity and does not seem to prevent repeat chelations within six months.

  5. Distribution and effects of intravenous lead in the fetoplacental unit of the rat

    International Nuclear Information System (INIS)

    Hackett, P.L.; Hess, J.O.; Sikov, M.R.

    1982-01-01

    Lead metabolism was studied in the fetoplacental unit (FPU) of Wistar rats during the genesis of developmental abnormalities and embryonic death. Female rats were injected iv with tracer 210 Pb(NO 3 ) 2 , alone or in combination with 5 or 25 mg Pb(NO 3 ) 2 /kg, at 9 or 15 days of gestation (dg). The distribution of lead and its effects were determined in the FPUs during the ensuing 30-h period and at 20 dg. Hemorrhage of the egg cylinder was noted as early as 6 h postinjection of 25 mg/kg at 9 dg. By 20 dg, fetuses exhibited characteristic stunting and external malformations (gastrochisis and severe skeletal defects). Administration of this dose at 15 dg produced petechial hemorrhage in fetal brain within 90 min; more massive hemorrhage was a consistent observation by 24 h. At 20 dg, embryo mortality was 44% in rats injected with 25 mg/kg at 9 dg and 100% in those injected at 15 dg. At 90 min after injection, lead content of 15-dg FPUs was 10 times that of the 9-dg FPUs, but the weights of the 15-dg FPUs were 16 times greater. Values remained relatively constant in 15-dg FPUs for 30 h, but early clearance was observed after injection at 9 dg, with a return to 90-min values by 20 dg. In the 15-dg FPUs, placental clearance was followed by fetal lead incorporation, which reached a maximum at 6 h. Fetal lead values were constant from 6 to 30 h after injection at tracer and 5-mg/kg dose levels, but values increased progressively at 25 mg/kg. Both temporal and quantitative relationships of fetal lead metabolism were disrupted by the 25-mg/kg dose, but the nature of the effect was determined by the stage of fetal development at exposure

  6. Radiogenic Lead Isotopes and Time Stratigraphy in the Hudson River, New York

    International Nuclear Information System (INIS)

    Chillrud, Steven N.; Bopp, Richard F.; Ross, James M.; Chaky, Damon A.; Hemming, Sidney; Shuster, Edward L.; Simpson, H. James; Estabrooks, Frank

    2004-01-01

    Radionuclide, radiogenic lead isotope and trace metal analyses on fine-grained sediment cores collected along 160 km of the upper and tidal Hudson River were used to examine temporal trends of contaminant loadings and to develop radiogenic lead isotopes both as a stratigraphic tool and as tracers for resolving decadal particle transport fluxes. Very large inputs of Cd, Sb, Pb, and Cr are evident in the sediment record, potentially from a single manufacturing facility. The total range in radiogenic lead isotope ratios observed in well-dated cores collected about 24 km downstream of the plant is large (e.g., maximum difference in 206 Pb/ 207 Pb is 10%), characterized by four major shifts occurring in the 1950s, 1960s, 1970s and 1980s. The upper Hudson signals in Cd and radiogenic lead isotopes were still evident in sediments collected 160 km downstream in the tidal Hudson. The large magnitude and abrupt shifts in radiogenic lead isotope ratios as a function of depth provide sensitive temporal constraints that complement information derived from radionuclide analyses to significantly improve the precision of dating assignments. Application of a simple dilution model to data from paired cores suggests much larger sediment inputs in one section of the river than previously reported, suggesting particle influxes to the Hudson have been underestimated

  7. Distribution of arrival times of muons with energy greater than 10 GeV

    International Nuclear Information System (INIS)

    Badino, G.; Bianco, P.; Dardo, M.; Fulgione, W.; Galeotti, P.; Periale, L.; Saavedra, O.

    1982-01-01

    Recent data on the arrival time distribution of EAS of primary energy >=10 14 eV, and of high energy muons detected at great depth (5000 mwe), seem to indicate an excess of short time intervals. We are using an apparatus, installed at 40 mwe underground, and a surface shower array to investigate the distributions of a) the time intervals between muon groups and b) the arrival times of muons with respect to the front of air showers. Preliminary results of this search are presented

  8. Eryptosis in lead-exposed workers

    International Nuclear Information System (INIS)

    Aguilar-Dorado, Itzel-Citlalli; Hernández, Gerardo; Quintanar-Escorza, Martha-Angelica; Maldonado-Vega, María; Rosas-Flores, Margarita; Calderón-Salinas, José-Víctor

    2014-01-01

    Eryptosis is a physiological phenomenon in which old and damaged erythrocytes are removed from circulation. Erythrocytes incubated with lead have exhibited major eryptosis. In the present work we found evidence of high levels of eryptosis in lead exposed workers possibly via oxidation. Blood samples were taken from 40 male workers exposed to lead (mean blood lead concentration 64.8 μg/dl) and non-exposed workers (4.2 μg/dl). The exposure to lead produced an intoxication characterized by 88.3% less δ-aminolevulinic acid dehydratase (δALAD) activity in lead exposed workers with respect to non-lead exposed workers. An increment of oxidation in lead exposed workers was characterized by 2.4 times higher thiobarbituric acid-reactive substance (TBARS) concentration and 32.8% lower reduced/oxidized glutathione (GSH/GSSG) ratio. Oxidative stress in erythrocytes of lead exposed workers is expressed in 192% higher free calcium concentration [Ca 2+ ] i and 1.6 times higher μ-calpain activity with respect to non-lead exposed workers. The adenosine triphosphate (ATP) concentration was not significantly different between the two worker groups. No externalization of phosphatidylserine (PS) was found in non-lead exposed workers (< 0.1%), but lead exposed workers showed 2.82% externalization. Lead intoxication induces eryptosis possibly through a molecular pathway that includes oxidation, depletion of reduced glutathione (GSH), increment of [Ca 2+ ], μ-calpain activation and externalization of PS in erythrocytes. Identifying molecular signals that induce eryptosis in lead intoxication is necessary to understand its physiopathology and chronic complications. - Graphical abstract: Fig. 1. (A) Blood lead concentration (PbB) and (B) phosphatidylserine externalization on erythrocyte membranes of non-lead exposed (□) and lead exposed workers (■). Values are mean ± SD. *Significantly different (P < 0.001). - Highlights: • Erythrocytes of lead exposed workers showed higher PS

  9. Eryptosis in lead-exposed workers

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar-Dorado, Itzel-Citlalli [Biochemistry Department, Centro de Investigación y Estudios Avanzados IPN, México, DF (Mexico); Hernández, Gerardo [Section of Methodology of Science, Centro de Investigación y Estudios Avanzados IPN, México, DF (Mexico); Quintanar-Escorza, Martha-Angelica [Faculty of Medicine, UJED, Durango, DGO (Mexico); Maldonado-Vega, María [CIATEC, León, GTO (Mexico); Rosas-Flores, Margarita [Biochemistry Department, Centro de Investigación y Estudios Avanzados IPN, México, DF (Mexico); Calderón-Salinas, José-Víctor, E-mail: jcalder@cinvestav.mx [Biochemistry Department, Centro de Investigación y Estudios Avanzados IPN, México, DF (Mexico)

    2014-12-01

    Eryptosis is a physiological phenomenon in which old and damaged erythrocytes are removed from circulation. Erythrocytes incubated with lead have exhibited major eryptosis. In the present work we found evidence of high levels of eryptosis in lead exposed workers possibly via oxidation. Blood samples were taken from 40 male workers exposed to lead (mean blood lead concentration 64.8 μg/dl) and non-exposed workers (4.2 μg/dl). The exposure to lead produced an intoxication characterized by 88.3% less δ-aminolevulinic acid dehydratase (δALAD) activity in lead exposed workers with respect to non-lead exposed workers. An increment of oxidation in lead exposed workers was characterized by 2.4 times higher thiobarbituric acid-reactive substance (TBARS) concentration and 32.8% lower reduced/oxidized glutathione (GSH/GSSG) ratio. Oxidative stress in erythrocytes of lead exposed workers is expressed in 192% higher free calcium concentration [Ca{sup 2+}]{sub i} and 1.6 times higher μ-calpain activity with respect to non-lead exposed workers. The adenosine triphosphate (ATP) concentration was not significantly different between the two worker groups. No externalization of phosphatidylserine (PS) was found in non-lead exposed workers (< 0.1%), but lead exposed workers showed 2.82% externalization. Lead intoxication induces eryptosis possibly through a molecular pathway that includes oxidation, depletion of reduced glutathione (GSH), increment of [Ca{sup 2+}], μ-calpain activation and externalization of PS in erythrocytes. Identifying molecular signals that induce eryptosis in lead intoxication is necessary to understand its physiopathology and chronic complications. - Graphical abstract: Fig. 1. (A) Blood lead concentration (PbB) and (B) phosphatidylserine externalization on erythrocyte membranes of non-lead exposed (□) and lead exposed workers (■). Values are mean ± SD. *Significantly different (P < 0.001). - Highlights: • Erythrocytes of lead exposed workers

  10. Does Viewing Pornography Diminish Religiosity Over Time? Evidence From Two-Wave Panel Data.

    Science.gov (United States)

    Perry, Samuel L

    2017-02-01

    Research consistently shows a negative association between religiosity and viewing pornography. While scholars typically assume that greater religiosity leads to less frequent pornography use, none have empirically examined whether the reverse could be true: that greater pornography use may lead to lower levels of religiosity over time. I tested for this possibility using two waves of the nationally representative Portraits of American Life Study (PALS). Persons who viewed pornography at all at Wave 1 reported more religious doubt, lower religious salience, and lower prayer frequency at Wave 2 compared to those who never viewed porn. Considering the effect of porn-viewing frequency, viewing porn more often at Wave 1 corresponded to increases in religious doubt and declining religious salience at Wave 2. However, the effect of earlier pornography use on later religious service attendance and prayer was curvilinear: Religious service attendance and prayer decline to a point and then increase at higher levels of pornography viewing. Testing for interactions revealed that all effects appear to hold regardless of gender. Findings suggest that viewing pornography may lead to declines in some dimensions of religiosity but at more extreme levels may actually stimulate, or at least be conducive to, greater religiosity along other dimensions.

  11. Coupled Heuristic Prediction of Long Lead-Time Accumulated Total Inflow of a Reservoir during Typhoons Using Deterministic Recurrent and Fuzzy Inference-Based Neural Network

    Directory of Open Access Journals (Sweden)

    Chien-Lin Huang

    2015-11-01

    Full Text Available This study applies Real-Time Recurrent Learning Neural Network (RTRLNN and Adaptive Network-based Fuzzy Inference System (ANFIS with novel heuristic techniques to develop an advanced prediction model of accumulated total inflow of a reservoir in order to solve the difficulties of future long lead-time highly varied uncertainty during typhoon attacks while using a real-time forecast. For promoting the temporal-spatial forecasted precision, the following original specialized heuristic inputs were coupled: observed-predicted inflow increase/decrease (OPIID rate, total precipitation, and duration from current time to the time of maximum precipitation and direct runoff ending (DRE. This study also investigated the temporal-spatial forecasted error feature to assess the feasibility of the developed models, and analyzed the output sensitivity of both single and combined heuristic inputs to determine whether the heuristic model is susceptible to the impact of future forecasted uncertainty/errors. Validation results showed that the long lead-time–predicted accuracy and stability of the RTRLNN-based accumulated total inflow model are better than that of the ANFIS-based model because of the real-time recurrent deterministic routing mechanism of RTRLNN. Simulations show that the RTRLNN-based model with coupled heuristic inputs (RTRLNN-CHI, average error percentage (AEP/average forecast lead-time (AFLT: 6.3%/49 h can achieve better prediction than the model with non-heuristic inputs (AEP of RTRLNN-NHI and ANFIS-NHI: 15.2%/31.8% because of the full consideration of real-time hydrological initial/boundary conditions. Besides, the RTRLNN-CHI model can promote the forecasted lead-time above 49 h with less than 10% of AEP which can overcome the previous forecasted limits of 6-h AFLT with above 20%–40% of AEP.

  12. Texture and anisotropy in ferroelectric lead metaniobate

    Science.gov (United States)

    Iverson, Benjamin John

    Ferroelectric lead metaniobate, PbNb2O6, is a piezoelectric ceramic typically used because of its elevated Curie temperature and anisotropic properties. However, the piezoelectric constant, d33, is relatively low in randomly oriented ceramics when compared to other ferroelectrics. Crystallographic texturing is often employed to increase the piezoelectric constant because the spontaneous polarization axes of grains are better aligned. In this research, crystallographic textures induced through tape casting are distinguished from textures induced through electrical poling. Texture is described using multiple quantitative approaches utilizing X-ray and neutron time-of-flight diffraction. Tape casting lead metaniobate with an inclusion of acicular template particles induces an orthotropic texture distribution. Templated grain growth from seed particles oriented during casting results in anisotropic grain structures. The degree of preferred orientation is directly linked to the shear behavior of the tape cast slurry. Increases in template concentration, slurry viscosity, and casting velocity lead to larger textures by inducing more particle orientation in the tape casting plane. The maximum 010 texture distributions were two and a half multiples of a random distribution. Ferroelectric texture was induced by electrical poling. Electric poling increases the volume of material oriented with the spontaneous polarization direction in the material. Samples with an initial paraelectric texture exhibit a greater change in the domain volume fraction during electrical poling than randomly oriented ceramics. In tape cast samples, the resulting piezoelectric response is proportional to the 010 texture present prior to poling. This results in property anisotropy dependent on initial texture. Piezoelectric properties measured on the most textured ceramics were similar to those obtained with a commercial standard.

  13. Lead poisoning in cattle and sheep

    Energy Technology Data Exchange (ETDEWEB)

    Allcroft, R

    1951-09-15

    The danger of paint and other lead compounds to the bovine is well recognized and has been recorded and discussed fairly extensively from time to time. The literature indicates that the calf is extremely susceptible to lead poisoning, but relatively little has been reported regarding the levels of lead in tissues of animals which have died as a result of lead poisoning, and still less in animals suspected of suffering from sub-lethal doses of lead compounds. In order to provide sufficient data to enable interpretation of figures obtained from tissues in cases of suspected lead poisoning sent in from the field, and to provide information on the metabolic fate of lead in ruminants, investigations were made at Weybridge on the absorption, excretion, retention and general metabolic effects of lead in both cattle and sheep and the results have been published in a series of five papers. In this brief review it is intended to discuss points from these and subsequent investigations which are likely to be of interest to the veterinarian.

  14. Total lead concentration in new decorative enamel paints in Lebanon, Paraguay and Russia.

    Science.gov (United States)

    Clark, C Scott; Speranskaya, Olga; Brosche, Sara; Gonzalez, Hebe; Solis, Daniela; Kodeih, Naji; Roda, Sandy; Lind, Caroline

    2015-04-01

    Lead concentrations in new enamel decorative paints were determined in three countries in different areas of the world where data were not previously available. The average total lead concentration of the enamel decorative paints purchased in Lebanon, Paraguay and Russia was 24,500ppm (ppm, dry weight), more than 270 times the current limit of 90ppm in Canada and in the United States. Sixty-three percent of these paints contained concentrations greater than 90ppm. Fifty-nine percent contained concentrations greater than 600ppm, the current limit in some countries. The maximum concentrations found were 236,000ppm in Lebanon, 169,000ppm in Paraguay and 52,900ppm in Russia. An average of 29% of the samples contained exceedingly high lead concentrations, >=10,000ppm. Five brands of paint were sampled in each of Lebanon and Paraguay and seven in Russia. Three colors from each brand were analyzed. For five of the six samples of the two brands in Lebanon with affiliations outside the country, the lead concentrations ranged from 1360ppm to 135,000ppm. In Lebanon the maximum concentration in the Egypt-affiliated brand (Sipes) was 135,000ppm and the maximum for the USA-affiliated brand (Dutch Boy) was 32,400ppm. Lead was not detected in any paints from the three of the four brands of paint purchased in Paraguay that had headquarters/affiliations in other countries (Brazil-Coralit), Germany (Suvinil) and USA (Novacor)). Two of the three paints from each of the other Paraguay brands contained high levels of lead with the maximum concentrations of 108,000 and 168,000ppm; one of these brands was manufactured under a license from ICI in the Netherlands. All of the paints purchased in Russia were from Russian brands and were manufactured in Russia. All three paints from one brand contained below detection levels of lead. The maximum levels of lead in the other six brands in Russia ranged from 3230 to 52,900ppm. The two brands with the highest lead concentration, TEKS and LAKRA

  15. Study of lead phytoavailability for atmospheric industrial micronic and sub-micronic particles in relation with lead speciation

    Energy Technology Data Exchange (ETDEWEB)

    Uzu, G. [EcoLab UMR 5245 CNRS-INPT-UPS, ENSAT BP 32607 Auzeville Tolosane, 31326 Castanet Tolosan (France)], E-mail: gaelle.uzu@ensat.fr; Sobanska, S. [LASIR UMR 8516, Universite des Sciences et Technologies de Lille, Batiment C5, 59655 Villeneuve d' Ascq Cedex (France)], E-mail: Sophie.Sobanska@univ-lille1.fr; Aliouane, Y. [EcoLab UMR 5245 CNRS-INPT-UPS, ENSAT BP 32607 Auzeville Tolosane, 31326 Castanet Tolosan (France); Pradere, P. [Chemical Metal Treatment Company, STCM, 30-32 chemin de Fondeyre, 31200 Toulouse (France)], E-mail: p.pradere@stc-metaux.com; Dumat, C. [EcoLab UMR 5245 CNRS-INPT-UPS, ENSAT BP 32607 Auzeville Tolosane, 31326 Castanet Tolosan (France)], E-mail: camille.dumat@ensat.fr

    2009-04-15

    Particles from channelled emissions of a battery recycling facility were size-segregated and investigated to correlate their speciation and morphology with their transfer towards lettuce. Microculture experiments carried out with various calcareous soils spiked with micronic and sub-micronic particles (1650 {+-} 20 mg Pb kg{sup -1}) highlighted a greater transfer in soils mixed with the finest particles. According to XRD and Raman spectroscopy results, the two fractions presented differences in the amount of minor lead compounds like carbonates, but their speciation was quite similar, in decreasing order of abundance: PbS, PbSO{sub 4}, PbSO{sub 4}.PbO, {alpha}-PbO and Pb{sup 0}. Morphology investigations revealed that PM{sub 2.5} (i.e. Particulate Matter 2.5 composed of particles suspended in air with aerodynamic diameters of 2.5 {mu}m or less) contained many Pb nanoballs and nanocrystals which could influence lead availability. The soil-plant transfer of lead was mainly influenced by size and was very well estimated by 0.01 M CaCl{sub 2} extraction. - The soil-lettuce lead transfer from atmospheric industrial sub-micronic and micronic particles depends on particle size.

  16. Study of lead phytoavailability for atmospheric industrial micronic and sub-micronic particles in relation with lead speciation

    International Nuclear Information System (INIS)

    Uzu, G.; Sobanska, S.; Aliouane, Y.; Pradere, P.; Dumat, C.

    2009-01-01

    Particles from channelled emissions of a battery recycling facility were size-segregated and investigated to correlate their speciation and morphology with their transfer towards lettuce. Microculture experiments carried out with various calcareous soils spiked with micronic and sub-micronic particles (1650 ± 20 mg Pb kg -1 ) highlighted a greater transfer in soils mixed with the finest particles. According to XRD and Raman spectroscopy results, the two fractions presented differences in the amount of minor lead compounds like carbonates, but their speciation was quite similar, in decreasing order of abundance: PbS, PbSO 4 , PbSO 4 .PbO, α-PbO and Pb 0 . Morphology investigations revealed that PM 2.5 (i.e. Particulate Matter 2.5 composed of particles suspended in air with aerodynamic diameters of 2.5 μm or less) contained many Pb nanoballs and nanocrystals which could influence lead availability. The soil-plant transfer of lead was mainly influenced by size and was very well estimated by 0.01 M CaCl 2 extraction. - The soil-lettuce lead transfer from atmospheric industrial sub-micronic and micronic particles depends on particle size

  17. A geometric process model for M/PH(M/PH)/1/K queue with new service machine procurement lead time

    Science.gov (United States)

    Yu, Miaomiao; Tang, Yinghui; Fu, Yonghong

    2013-06-01

    In this article, we consider a geometric process model for M/PH(M/PH)/1/K queue with new service machine procurement lead time. A maintenance policy (N - 1, N) based on the number of failures of the service machine is introduced into the system. Assuming that a failed service machine after repair will not be 'as good as new', and the spare service machine for replacement is only available by an order. More specifically, we suppose that the procurement lead time for delivering the spare service machine follows a phase-type (PH) distribution. Under such assumptions, we apply the matrix-analytic method to develop the steady state probabilities of the system, and then we obtain some system performance measures. Finally, employing an important Lemma, the explicit expression of the long-run average cost rate for the service machine is derived, and the direct search method is also implemented to determine the optimal value of N for minimising the average cost rate.

  18. Sagebrush, greater sage-grouse, and the occurrence and importance of forbs

    Science.gov (United States)

    Pennington, Victoria E.; Schlaepfer, Daniel R.; Beck, Jeffrey L.; Bradford, John B.; Palmquist, Kyle A.; Lauenroth, William K.

    2016-01-01

    Big sagebrush (Artemisia tridentata Nutt.) ecosystems provide habitat for sagebrush-obligate wildlife species such as the Greater Sage-Grouse (Centrocercus urophasianus). The understory of big sagebrush plant communities is composed of grasses and forbs that are important sources of cover and food for wildlife. The grass component is well described in the literature, but the composition, abundance, and habitat role of forbs in these communities is largely unknown. Our objective was to synthesize information about forbs and their importance to Greater Sage-Grouse diets and habitats, how rangeland management practices affect forbs, and how forbs respond to changes in temperature and precipitation. We also sought to identify research gaps and needs concerning forbs in big sagebrush plant communities. We searched for relevant literature including journal articles and state and federal agency reports. Our results indicated that in the spring and summer, Greater Sage-Grouse diets consist of forbs (particularly species in the Asteraceae family), arthropods, and lesser amounts of sagebrush. The diets transition to sagebrush in fall and winter. Forbs provide cover for Greater Sage-Grouse individuals at their lekking, nesting, and brood-rearing sites, and the species has a positive relationship with arthropod presence. The effect of grazing on native forbs may be compounded by invasion of nonnative species and differs depending on grazing intensity. The effect of fire on forbs varies greatly and may depend on time elapsed since burning. In addition, chemical and mechanical treatments affect annual and perennial forbs differently. Temperature and precipitation influence forb phenology, biomass, and abundance differently among species. Our review identified several uncertainties and research needs about forbs in big sagebrush ecosystems. First, in many cases the literature about forbs is reported only at the genus or functional type level. Second, information about forb

  19. No time to lose. The IAEA seeks greater resources to fight cancer in the world's poorest regions

    International Nuclear Information System (INIS)

    Samiei, M.; Rosenthal, M.D.; Kinley, D. III

    2005-01-01

    The IAEA is stepping up efforts to help more patients survive cancer through earlier diagnosis and better treatment. As the cancer burden mounts in developing countries, many more doctors, nurses, and skilled personnel will be needed, as well as necessary equipment. Through IAEA supported projects, some institutes in developing Member States are better prepared to help patients breast cancer. But equipment alone will not solve the problem, and establishing new treatment facilities is a long process that requires strong governmental support. It involves staff training (up to four years for a radiation oncologist and two years for a medical physicist), facility planning and construction, equipment specification and procurement, installation, acceptance testing and commissioning, registration and licensing, designing protocol and procedure manuals, and development of quality control programmes prior to initiating treatment. Typically, up to five years may be needed to complete all phases. However, in many cases improvements in existing facilities can lead to significant increases in patient treatment in much less time. The IAEA continues to address this enormous task and is currently involved in helping to upgrade radiotherapy facilities, train staff and establish quality assurance programmes in approximately 100 countries worldwide through national and regional projects

  20. Creatine Supplementation During Resistance Training Does Not Lead to Greater Bone Mineral Density in Older Humans: A Brief Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Scott C. Forbes

    2018-04-01

    Full Text Available Creatine supplementation during resistance training has potential beneficial effects on properties of bone in aging adults. We systematically reviewed randomized controlled trials (RCTs investigating the effect of creatine supplementation combined with resistance training on bone mineral density (BMD in aging adults. We searched PubMed and SPORTDiscus databases and included RCTs of ≥3 months duration that examined the combined effect of creatine and resistance training on bone mineral in adults >50 years of age or postmenopausal. Meta-analyses were performed when applicable trials were available on whole body and clinically important bone sites. Five trials met inclusion criteria with a total of 193 participants. Two of the studies reported significant benefits of creatine supplementation and resistance training compared to resistance training alone on bone. Meta-analyses revealed no greater effect of creatine and resistance training compared to resistance training alone on whole body BMD (MD: 0.00, 95% CI −0.01 to 0.01, p = 0.50, hip BMD (MD −0.01, 95% CI −0.02 to 0.01, p = 0.26, femoral neck BMD (MD 0.00, 95% CI −0.01 to 0.01, p = 0.71, and lumbar spine BMD (MD 0.01, 95% CI −0.01 to 0.03, p = 0.32. In conclusion, there is a limited number of RCTs examining the effects of creatine supplementation and resistance training on BMD in older adults. Our meta-analyses revealed no significant effect on whole body, hip, femoral neck, or lumbar spine BMD when comparing creatine and resistance training to resistance training alone. Future longer term (>12 month trials with higher resistance training frequencies (≥3 times per week is warranted.

  1. Remediation of lead from lead electroplating industrial effluent using sago waste.

    Science.gov (United States)

    Jeyanthi, G P; Shanthi, G

    2007-01-01

    Heavy metals are known toxicants, which inflict acute disorders to the living beings. Electroplating industries pose great threat to the environment through heavy load of metals in the wastewater discharged on land and water sources. In the present study, sago processing waste, which is both a waste and a pollutant, was used to adsorb lead ions from lead electroplating industrial effluent. Two types of sago wastes, namely, coarse sago waste and fine sago waste were used to study their adsorption capacity with the batch adsorption and Freundlich adsorption isotherm. The parameters that were considered for batch adsorption were pH (4, 5 and 6), time of contact (1, 2 and 3 hrs), temperature (30, 37 and 45 degrees C) and dosage of the adsorbent (2,4 and 6 g/L). The optimal condition for the effective removal of lead was found to be pH 5, time of contact 3 hrs, temperature 30 degrees C and dosage 4 g/L with coarse sago waste than fine sago waste.

  2. An earlier time of scan is associated with greater threat-related amygdala reactivity.

    Science.gov (United States)

    Baranger, David A A; Margolis, Seth; Hariri, Ahmad R; Bogdan, Ryan

    2017-08-01

    Time-dependent variability in mood and anxiety suggest that related neural phenotypes, such as threat-related amygdala reactivity, may also follow a diurnal pattern. Here, using data from 1,043 young adult volunteers, we found that threat-related amygdala reactivity was negatively coupled with time of day, an effect which was stronger in the left hemisphere (β = -0.1083, p-fdr = 0.0012). This effect was moderated by subjective sleep quality (β = -0.0715, p-fdr = 0.0387); participants who reported average and poor sleep quality had relatively increased left amygdala reactivity in the morning. Bootstrapped simulations suggest that similar cross-sectional samples with at least 300 participants would be able to detect associations between amygdala reactivity and time of scan. In control analyses, we found no associations between time and V1 activation. Our results provide initial evidence that threat-related amygdala reactivity may vary diurnally, and that this effect is potentiated among individuals with average to low sleep quality. More broadly, our results suggest that considering time of scan in study design or modeling time of scan in analyses, as well as collecting additional measures of circadian variation, may be useful for understanding threat-related neural phenotypes and their associations with behavior, such as fear conditioning, mood and anxiety symptoms, and related phenotypes. © The Author (2017). Published by Oxford University Press.

  3. Torsion of the Greater Omentum Secondary to Omental Lymphangioma in a Child: A Case Report

    International Nuclear Information System (INIS)

    Mistry, Kewal Arunkumar; Iyer, Dayashankar

    2015-01-01

    Omental cyst and omental torsion both are uncommon but important causes of acute abdomen with a difficult clinical diagnosis due to nonspecific features. Here we report a case of an eight year old child with acute abdominal pain referred for USG and CT scan which revealed two cysts in greater omentum leading to secondary omental torsion. An eight year old male child presented to casualty with severe pain abdomen since 1 day. There was no history of vomiting or altered bowel habits. The patient was febrile with tachycardia on arrival. On examination rigidity and tenderness all over abdomen were present. Serum amylase was within normal range. USG and CECT abdomen were done subsequently. USG showed two well defined cystic lesions in lower abdomen with presence of some internal echogenic debris and calcified foci in their dependent part. There was also presence of omentum with a whirl of blood vessels seen along anterior abdominal wall leading to these lesions suggesting torsion. On colour Doppler the presence of blood flow within the whirl of vessels was seen. Mild amount of free fluid was also seen in the peritoneal cavity. On CECT abdomen the findings of omental cysts and torsion of greater omentum with free fluid in abdomen were confirmed. The cysts measured 60×55 and 65×55mm on CT. The patient was taken for an emergency laparotomy for indication of acute generalized peritonitis. Two large omental cysts were found in the pelvic cavity along with torsed greater omentum along with 150 ml of hemorrhagic fluid in peritoneal cavity. The cysts and twisted necrotic part of the greater omentum were excised at surgery. No postoperative complications were observed. Histopathologic examination was suggestive of lymphangioma of omentum. Lymphangioma of the omentum is an not very uncommon however acute presentation with omental torsion and infarction is an unusual entity. Optimal utilization of preoperative imaging with USG, Doppler and contrast enhanced CT scan can provide

  4. Is Industry Funding Associated with Greater Scholarly Impact Among Academic Neurosurgeons?

    Science.gov (United States)

    Eloy, Jean Anderson; Kilic, Suat; Yoo, Nicholas G; Mcleod, Thomas; Svider, Peter F; Baredes, Soly; Folbe, Adam J; Couldwell, William T; Liu, James K

    2017-07-01

    To determine the relationship between industry payments and scholarly impact among academic neurosurgeons. Faculty names and academic rank data were obtained from department websites, bibliometric data were obtained from the Scopus database, and industry payment data were obtained from the Center for Medicare and Medicaid Services open payments database (openpayments.cms.gov). The h-index was used to estimate scholarly impact. Payments were classified as "general," "associated research," and "research payments." Subgroup analyses were done for academic rank, fellowship training, and sex. Among 1008 academic neurosurgeons, scholarly impact was greater among individuals receiving associated research industry support compared with those not receiving it. Scholarly impact also was greater among individuals who received more than $10,000 of any type of industry support compared with individuals who received less than that or no payment. This association also was seen in fellowship-trained surgeons. Female neurosurgeons were less likely than male neurosurgeons to get industry funding and were likely to get less funding. There is a strong association between associated research funding from industry and scholarly impact among academic neurosurgeons. It's unclear whether this association is a result of funding facilitating more research projects that eventually lead to more high-impact publications, if industry is providing more funding to academic neurosurgeons with greater scholarly impact, or whether it represents intrinsic academic activity among a group of neurosurgeons who are more likely to be academically productive and procure funding from all potential sources to increase this activity. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Blood lead exposure concentrations in mottled ducks (Anas fulvigula) on the upper Texas coast

    Science.gov (United States)

    McDowell, Stephen K.; Conway, Warren C.; Haukos, David A.; Moon, Jena A.; Comer, Christopher E.; Hung, I-Kuai

    2015-01-01

    The mottled duck (Anas fulvigula) is a non-migratory waterfowl species dependent upon coastal marsh systems, including those on the Texas Chenier Plain National Wildlife Refuge (NWR) Complex, and considered a regional indicator species of marsh habitat quality. Research from the early 1970s, 1990s, and early-2000s indicated that mottled ducks continued to exhibit elevated wing-bone lead (Pb) concentrations, decades after implementation of non-toxic shot regulations. However, wing-bone concentrations reflect lifetime accumulation of Pb, whereas blood Pb concentrations reflect more recent exposure. To identify current potentially relevant temporal windows of Pb exposure, we collected 260 blood samples from mottled ducks during summer (n=124) and winter (n=136) from 2010–2012 on the Texas Chenier Plain NWR Complex. We quantified baseline blood Pb concentrations for all ages of mottled ducks, and hypothesized that blood lead concentrations would remain elevated above background levels (200 µg L–1) despite the 1983 and 1991 lead shot bans. Blood Pb concentrations ranged from below detection limits to >12,000 µg L–1, where >200 µg L–1 was associated with exposure levels above background concentrations. Male mottled ducks had the greatest blood Pb concentrations (30 times greater than females) with concentrations greater during winter than summer. Likewise, the proportion of exposed (>200 µg L–1) females increased from 14%–47% from summer to winter, respectively. Regardless of sex, adult mottled duck blood Pb concentrations were five times greater than juveniles, particularly during winter. We identified five plausible models that influenced blood Pb levels where year, site, and interactions among age*sex*season and between age*season were included in the top-ranked models. Frequency of exposure was greatest during winter, increasing from 12% in summer to 55% in winter, indicating that a temporal exposure window to environmental Pb exists between nesting

  6. Inattentional Deafness: Visual Load Leads to Time-Specific Suppression of Auditory Evoked Responses.

    Science.gov (United States)

    Molloy, Katharine; Griffiths, Timothy D; Chait, Maria; Lavie, Nilli

    2015-12-09

    Due to capacity limits on perception, conditions of high perceptual load lead to reduced processing of unattended stimuli (Lavie et al., 2014). Accumulating work demonstrates the effects of visual perceptual load on visual cortex responses, but the effects on auditory processing remain poorly understood. Here we establish the neural mechanisms underlying "inattentional deafness"--the failure to perceive auditory stimuli under high visual perceptual load. Participants performed a visual search task of low (target dissimilar to nontarget items) or high (target similar to nontarget items) load. On a random subset (50%) of trials, irrelevant tones were presented concurrently with the visual stimuli. Brain activity was recorded with magnetoencephalography, and time-locked responses to the visual search array and to the incidental presence of unattended tones were assessed. High, compared to low, perceptual load led to increased early visual evoked responses (within 100 ms from onset). This was accompanied by reduced early (∼ 100 ms from tone onset) auditory evoked activity in superior temporal sulcus and posterior middle temporal gyrus. A later suppression of the P3 "awareness" response to the tones was also observed under high load. A behavioral experiment revealed reduced tone detection sensitivity under high visual load, indicating that the reduction in neural responses was indeed associated with reduced awareness of the sounds. These findings support a neural account of shared audiovisual resources, which, when depleted under load, leads to failures of sensory perception and awareness. The present work clarifies the neural underpinning of inattentional deafness under high visual load. The findings of near-simultaneous load effects on both visual and auditory evoked responses suggest shared audiovisual processing capacity. Temporary depletion of shared capacity in perceptually demanding visual tasks leads to a momentary reduction in sensory processing of auditory

  7. Comparison of Inventory Systems with Service, Positive Lead-Time, Loss, and Retrial of Customers

    Directory of Open Access Journals (Sweden)

    A. Krishnamoorthy

    2007-01-01

    Full Text Available We analyze and compare three (s,S inventory systems with positive service time and retrial of customers. In all of these systems, arrivals of customers form a Poisson process and service times are exponentially distributed. When the inventory level depletes to s due to services, an order of replenishment is placed. The lead-time follows an exponential distribution. In model I, an arriving customer, finding the inventory dry or server busy, proceeds to an orbit with probability γ and is lost forever with probability (1−γ. A retrial customer in the orbit, finding the inventory dry or server busy, returns to the orbit with probability δ and is lost forever with probability (1−δ. In addition to the description in model I, we provide a buffer of varying (finite capacity equal to the current inventory level for model II and another having capacity equal to the maximum inventory level S for model III. In models II and III, an arriving customer, finding the buffer full, proceeds to an orbit with probability γ and is lost forever with probability (1−γ. A retrial customer in the orbit, finding the buffer full, returns to the orbit with probability δ and is lost forever with probability (1−δ. In all these models, the interretrial times are exponentially distributed with linear rate. Using matrix-analytic method, we study these inventory models. Some measures of the system performance in the steady state are derived. A suitable cost function is defined for all three cases and analyzed using graphical illustrations.

  8. Effect of a real-time tele-transmission system of 12-lead electrocardiogram on the first-aid for athletes with ST-elevation myocardial infarction.

    Science.gov (United States)

    Zhang, Huan; Song, Donghan; An, Lina

    2016-05-01

    To study the effect of a real-time tele-transmission system of 12-lead electrocardiogram on door-to-balloon time in athletes with ST-elevation myocardial infarction. A total of 60 athletes with chest pain diagnosed as ST-elevation myocardial infarction (STEMI) from our hospital were randomly divided into group A (n=35) and group B (n=25), the patients in group A transmitted the real-time tele-transmission system of 12-lead electrocardiogram to the chest pain center before arriving in hospital, however, the patients in group B not. The median door-to-balloon time was significant shorter in-group A than group B (38min vs 94 min, p0.05). The median length of stay was significant reduced in-group A (5 days vs 7 days, pelectrocardiogram is beneficial to the pre-hospital diagnosis of STEMI.

  9. Time to talk, time to see: changing microeconomies of professional practice among nurses and doctors in Australian general practice.

    Science.gov (United States)

    Phillips, Christine; Dwan, Kathryn; Pearce, Christopher; Hall, Sally; Porritt, Julie; Yates, Rachel; Sibbald, Bonnie

    2007-08-01

    In Australia, more nurses are entering general practice, and nurses' work is being funded in increasingly complex ways through Medicare. Little research has explored the ways doctors and nurses realign their priorities and activities when working together in general practice. We undertook rapid, intensive multimethod studies of 25 general practices to explore the ways in which the labour of nurses and doctors was structured, and the implicit decisions made by both professions about the values placed on different ways of working and on their time. Data collected included photographs, floor-plans, interviews with 37 nurses, 24 doctors and 22 practice managers, and 50 hours of structured observation. Nursing time was constructed by both nurses and doctors as being fluid and non-contingent; they were regarded as being 'available' to patients in a way that doctors were not. Compared to medical time, nursing time could be disposed more flexibly, underpinning a valorized attribute of nursing: deep clinical and personal contact with patients. The location of practice nurses' desks in areas of traffic, such as administrative stations, or in the treatment room, underpinned this valuable unstructured contact with patients. Changes to the practice nurse role through direct fee-for-service items for nurses may lead to greater congruence between the microeconomies of nursing and medicine in general practice. In a time of pressure upon a primary care workforce, this is likely to lead to more independent clinical work by nurses, but may also lead to a decrease in flexible contact with patients.

  10. Pulse Generator Exchange Does Not Accelerate the Rate of Electrical Failure in a Recalled Small Caliber ICD Lead.

    Science.gov (United States)

    Lovelock, Joshua D; Premkumar, Ajay; Levy, Mathew R; Mengistu, Andenet; Hoskins, Michael H; El-Chami, Mikhael F; Lloyd, Michael S; Leon, Angel R; Langberg, Jonathan J; Delurgio, David B

    2015-12-01

    St. Jude Riata/Riata ST defibrillator leads (St. Jude Medical, Sylmar, CA, USA) were recalled by the Food and Drug Administration in 2011 for an increased rate of failure. More than 227,000 leads were implanted and at least 79,000 patients still have active Riata leads. Studies have examined clinical predictors of lead failure in Riata leads, but none have addressed the effect of implantable cardioverter defibrillator (ICD) generator exchange on lead failure. The purpose of this study is to assess the effect of ICD generator exchange on the rate of electrical failure in the Riata lead at 1 year. A retrospective chart review was conducted in patients who underwent implantation of a Riata/Riata ST lead at one center. Patients with a functioning Riata lead (with/without externalized conductor) at the time of ICD exchange were compared to controls with Riata leads implanted for a comparable amount of time who did not undergo generator replacement. Riata leads were implanted in 1,042 patients prior to the recall and 153 of these patients underwent generator exchange without lead replacement. Conductor externalization was noted in 21.5% of Riata leads in the ICD exchange cohort, which was not different from the control group (19.2%; P = 0.32). Two leads failed in the first year after generator replacement (1.5%) which did not significantly differ from the control group (2.0%; P = 0.57). At change-out, 54% received a commanded shock (18.6 ± 0.9 J) that did not result in any change in the high-voltage lead impedance (46.1 ± 1.1 ohms). Conductor externalization was seen frequently in our cohort of patients. ICD generator exchange did not accelerate the rate of Riata lead failure at 1 year. Although both the control and the change-out cohorts failed at a rate much greater than nonrecalled leads, generator exchange did not appear to add to the problem. ©2015 Wiley Periodicals, Inc.

  11. Comparative uptake of thorium-230, radium-226, lead-210 and polonium-210 by plants

    Energy Technology Data Exchange (ETDEWEB)

    D' Souza, T J; Mistry, K B

    1970-01-01

    The entry and translocation of /sup 230/thorium, /sup 226/radium, /sup 210/lead, and /sup 210/polonium were examined in nutrient culture experiments. Strontium-89 was included for comparison. Red kidney beans (Phaseolus vulgaris L.) were treated for a period of 15 days. Results indicate that accumulation of /sup 230/thorium, /sup 210/lead and /sup 210/polonium occurs predominantly in roots and only very small amounts of these nuclides are translocated to shoots. Over comparable periods, the accumulation of /sup 226/radium in roots is 2-3 times lower than that of the other nuclides of uranium series. However, the most significant difference between /sup 226/radium and other nuclides is in the extent of their upward transport which for radium is 50-200 times greater. The amount of radium translocated to shoots is comparable to that of strontium. The present evidence of rapid transfer of /sup 226/radium to shoots suggests that among the nuclides examined, /sup 226/radium is likely to make the major contribution to radioactivity in aerial tissues of plants grown under conditions where root absorption is the principal route of entry of the nuclides.

  12. Predicting Greater Prairie-Chicken Lek Site Suitability to Inform Conservation Actions.

    Directory of Open Access Journals (Sweden)

    Torre J Hovick

    Full Text Available The demands of a growing human population dictates that expansion of energy infrastructure, roads, and other development frequently takes place in native rangelands. Particularly, transmission lines and roads commonly divide rural landscapes and increase fragmentation. This has direct and indirect consequences on native wildlife that can be mitigated through thoughtful planning and proactive approaches to identifying areas of high conservation priority. We used nine years (2003-2011 of Greater Prairie-Chicken (Tympanuchus cupido lek locations totaling 870 unique leks sites in Kansas and seven geographic information system (GIS layers describing land cover, topography, and anthropogenic structures to model habitat suitability across the state. The models obtained had low omission rates (0.81, indicating high model performance and reliability of predicted habitat suitability for Greater Prairie-Chickens. We found that elevation was the most influential in predicting lek locations, contributing three times more predictive power than any other variable. However, models were improved by the addition of land cover and anthropogenic features (transmission lines, roads, and oil and gas structures. Overall, our analysis provides a hierarchal understanding of Greater Prairie-Chicken habitat suitability that is broadly based on geomorphological features followed by land cover suitability. We found that when land features and vegetation cover are suitable for Greater Prairie-Chickens, fragmentation by anthropogenic sources such as roadways and transmission lines are a concern. Therefore, it is our recommendation that future human development in Kansas avoid areas that our models identified as highly suitable for Greater Prairie-Chickens and focus development on land cover types that are of lower conservation concern.

  13. Como ayudar a los padres a prevenir el envenenamiento por plomo (Helping Parents Prevent Lead Poisoning). ERIC Digest.

    Science.gov (United States)

    Binns, Helen J.; Ricks, Omar Benton

    Children are at greater risk than adults for lead poisoning because children absorb lead more readily than adults, and a small amount of lead in children's bodies can do a great deal of harm. This Spanish-language Digest summarizes some of the causes and effects of childhood lead poisoning and suggests some lead poisoning prevention strategies…

  14. Heavy flavour production in proton-lead and lead-lead collisions with LHCb

    Science.gov (United States)

    Winn, Michael

    2017-11-01

    The LHCb experiment offers the unique opportunity to study heavy-ion interactions in the forward region (2 kinematic domain complementary to the other 3 large experiments at the LHC. The detector has excellent capabilities for reconstructing quarkonia and open charm states, including baryons, down to zero pT. It can separate the prompt and displaced charm components. In pPb collisions, both forward and backward rapidities are covered thanks to the possibility of beam reversal. Results include measurements of the nuclear modification factor and forward-backward ratio for charmonium, open charm and bottomonium states. These quantities are sensitive probes for nuclear effects in heavy flavour production. Perspectives are given with the large accumulated luminosity during the 2016 pPb run at the LHC. In 2015, LHCb participated successfully for the first time in the PbPb data-taking. The status of the forward prompt J/ψ nuclear modification factor measurement in lead-lead collisions is discussed.

  15. Greater autonomy at work

    NARCIS (Netherlands)

    Houtman, I.L.D.

    2004-01-01

    In the past 10 years, workers in the Netherlands increasingly report more decision-making power in their work. This is important for an economy in recession and where workers face greater work demands. It makes work more interesting, creates a healthier work environment, and provides opportunities

  16. Exploring the Relationship between Students' Understanding of Conventional Time and Deep (Geologic) Time

    Science.gov (United States)

    Cheek, Kim A.

    2013-07-01

    Many geologic processes occur in the context of geologic or deep time. Students of all ages demonstrate difficulty grasping this fundamental concept which impacts their ability to acquire other geoscience concepts. A concept of deep time requires the ability to sequence events on an immense temporal scale (succession) and to judge the durations of geologic processes based on the rates at which they occur. The twin concepts of succession and duration are the same ideas that underlie a concept of conventional time. If deep time is an extension of conventional time and not qualitatively different from it, students should display similar reasoning patterns when dealing with analogous tasks over disparate temporal periods. Thirty-five US students aged 13-24 years participated in individual task-based interviews to ascertain how they thought about succession and duration in conventional and deep time. This is the first attempt to explore this relationship in the same study in over 30 years. Most students successfully completed temporal succession tasks, but there was greater variability in responses on duration tasks. Conventional time concepts appear to impact how students reason about deep time. The application of spatial reasoning to temporal tasks sometimes leads to correct responses but in other instances does not. Implications for future research and teaching strategies are discussed.

  17. Cumulant generating function formula of heat transfer in ballistic systems with lead-lead coupling and general nonlinear systems

    Science.gov (United States)

    Li, Huanan

    2013-03-01

    Based on a two-time observation protocol, we consider heat transfer in a given time interval tM in a lead-junction-lead system taking coupling between the leads into account. In view of the two-time observation, consistency conditions are carefully verified in our specific family of quantum histories. Furthermore, its implication is briefly explored. Then using the nonequilibrium Green's function method, we obtain an exact formula for the cumulant generating function for heat transfer between the two leads, valid in both transient and steady-state regimes. Also, a compact formula for the cumulant generating function in the long-time limit is derived, for which the Gallavotti-Cohen fluctuation symmetry is explicitly verified. In addition, we briefly discuss Di Ventra's repartitioning trick regarding whether the repartitioning procedure of the total Hamiltonian affects the nonequilibrium steady-state current fluctuation. All kinds of properties of nonequilibrium current fluctuations, such as the fluctuation theorem in different time regimes, could be readily given according to these exact formulas. Finally a practical formalism dealing with cumulants of heat transfer across general nonlinear quantum systems is established based on field theoretical/algebraic method.

  18. Comparison of lead removal behaviors and generation of water-soluble sodium compounds in molten lead glass under a reductive atmosphere

    Science.gov (United States)

    Okada, Takashi; Nishimura, Fumihiro; Xu, Zhanglian; Yonezawa, Susumu

    2018-06-01

    We propose a method of reduction-melting at 1000 °C, using a sodium-based flux, to recover lead from cathode-ray tube funnel glass. To recover the added sodium from the treated glass, we combined a reduction-melting process with a subsequent annealing step at 700 °C, generating water-soluble sodium compounds in the molten glass. Using this combined process, this study compares lead removal behavior and the generation of water-soluble sodium compounds (sodium silicates and carbonates) in order to gain fundamental information to enhance the recovery of both lead and sodium. We find that lead removal increases with increasing melting time, whereas the generation efficiency of water-soluble sodium increases and decreases periodically. In particular, near 90% lead removal, the generation of water-soluble sodium compounds decreased sharply, increasing again with the prolongation of melting time. This is due to the different crystallization and phase separation efficiencies of water-soluble sodium in molten glass, whose structure continuously changes with lead removal. Previous studies used a melting time of 60 min in the processes. However, in this study, we observe that a melting time of 180 min enhances the water-soluble sodium generation efficiency.

  19. Quantifying Arabia-Eurasia convergence accommodated in the Greater Caucasus by paleomagnetic reconstruction

    Science.gov (United States)

    van der Boon, A.; van Hinsbergen, D. J. J.; Rezaeian, M.; Gürer, D.; Honarmand, M.; Pastor-Galán, D.; Krijgsman, W.; Langereis, C. G.

    2018-01-01

    Since the late Eocene, convergence and subsequent collision between Arabia and Eurasia was accommodated both in the overriding Eurasian plate forming the Greater Caucasus orogen and the Iranian plateau, and by subduction and accretion of the Neotethys and Arabian margin forming the East Anatolian plateau and the Zagros. To quantify how much Arabia-Eurasia convergence was accommodated in the Greater Caucasus region, we here provide new paleomagnetic results from 97 volcanic sites (∼500 samples) in the Talysh Mountains of NW Iran, that show ∼15° net clockwise rotation relative to Eurasia since the Eocene. We apply a first-order kinematic restoration of the northward convex orocline that formed to the south of the Greater Caucasus, integrating our new data with previously published constraints on rotations of the Eastern Pontides and Lesser Caucasus. This suggests that north of the Talysh ∼120 km of convergence must have been accommodated. North of the Eastern Pontides and Lesser Caucasus this is significantly more: 200-280 km. Our reconstruction independently confirms previous Caucasus convergence estimates. Moreover, we show for the first time a sharp contrast of convergence between the Lesser Caucasus and the Talysh. This implies that the ancient Paleozoic-Mesozoic transform plate boundary, preserved between the Iranian and East-Anatolian plateaus, was likely reactivated as a right-lateral transform fault since late Eocene time.

  20. Blood lead levels in preschool children in Cape Town

    Energy Technology Data Exchange (ETDEWEB)

    Deveaux, P.; Kibel, M.A.; Dempster, W.S.; Pocock, F.; Formenti, K.

    1986-03-29

    Blood lead levels were assessed in 293 children aged between 4 and 6 years attending preschool centers in metropolitan Cape Town in order to establish the degree of lead absorption. Anthropometric data, blood count, zinc protoporphyrin and blood lead level were obtained for each child. A questionnaire was used to determine socio-economic status, dietary habits and history of pica. Thirteen children, or 4,4% of those sampled, had blood levels of greater than or equal to 30 micrograms/dl. The majority of these children lived in close proximity to one another in a socially deprived inner urban environment. Environmental sampling for lead was carried out in the homes of children with the highest blood levels as well as in the homes of a matched control group with low levels living in the same area. The only difference was a significantly higher incidence of pica in the children with high levels.

  1. Involving Lead Users in Innovation

    DEFF Research Database (Denmark)

    Brem, Alexander; Bilgram, Volker; Gutstein, Adele

    2018-01-01

    Research on the lead user method has been conducted for more than thirty years and has shown that the method is more likely to generate breakthrough innovation than traditional market research tools. Based on a systematic literature review, this paper shows a detailed view on the broad variety...... of research on lead user characteristics, lead user processes, lead user identification and application, and success factors. The main challenge of the lead user method as identified in literature is the resource issue regarding time, manpower, and costs. Also, internal acceptance and the processing...... of the method have been spotted in literature, as well as the intellectual property protection issue. From the starting point of the initial lead user method process introduced by Lüthje and Herstatt (2004), results are integrated into a revisited view on the lead user method process. In addition, concrete...

  2. Radioactive lead studies in the human

    International Nuclear Information System (INIS)

    Blake, K.C.H.

    1980-08-01

    The differing susceptibility of individuals to the toxic effects of chronic lead exposure has never been fully understood. As the major intake of lead in the human is from food and beverages, any variation between individuals of the quantity of lead absorbed from the gut, and of the distribution and excretion of this lead, may account for the differences in individual susceptibility. The food and beverages themselves may have an influence, and to investigate their effects on absorption, distribution and excretion of lead, experiments were performed on normal subjects using a short lived radionuclide of lead, 203 Pb, and instruments generally available in Nuclear Medicine. Lead absorption between different individuals showed a wide variation when 203 Pb was taken as a single dose between meals. Minerals were found to be mainly responsible for affecting absorption when one subject ingested 203 Pb in control meals from which one dietary constituent at a time was omitted. Calcium and phosphorous were found to reduce the absorption of 203 Pb to approximately the same level as that produced by the total minerals. Calcium reduced absorption more than phosphorous when these minerals were ingested separately with 203 Pb. It was concluded that the calcium and phosphorous in the diet could influence susceptibility to lead toxicity through changes in the absorption of food and water lead and in the distribution of lead in the body. The results suggest that the prophylactic effect of calcium on lead absorption should be recognised and applied in this time of increased environmental levels of lead

  3. Analytical evidence of heterogeneous lead accumulation in the hypothalamic defence area and nucleus tractus solitarius.

    Science.gov (United States)

    Guimarães, D; Santos, J P; Carvalho, M L; Diniz, M S; House, B; Miller, V M

    2014-09-01

    Lead is a potent toxicant associated with adverse cardiovascular effects and hypertension in children. Yet, few studies have determined if autonomic dysfunction associated with lead exposure involves brain regions which regulate autonomic responses. Central autonomic nuclei such as the nucleus tractus solitarius (NTS) and hypothalamic defence area (HDA) may be particularly sensitive to lead infiltration because they are adjacent to ventricles and areas with semi-permeable blood-brain-barriers. To understand if autonomic nuclei are sensitive to lead accumulation Wistar rats were exposed to lead from the gestational period and lead levels were quantified in brain regions that regulate arterial pressure: the NTS and the HDA. Energy dispersive X-ray fluorescence (EDXRF) was used to quantify total brain lead levels and revealed no differences between exposed and control tissues; measured values were close to the detection limit (2μg/g). Electrothermal atomic absorption spectrometry (ETAAS) was also used, which has a greater sensitivity, to quantify lead. There was ∼2.1μg/g lead in the NTS and ∼3.1μg/g lead in the HDA of exposed rats, and no lead in the control rats. There were greater lead levels in the HDA (∼50%) as compared with the NTS. Pathology studies revealed more prominent lead granules in the HDA as compared with the NTS. Increased microglia and astrocyte activation was also noted in the NTS of lead exposed rats as compared with the HDA. Regional differences in neuro-inflammatory responses likely contribute to heterogeneous lead accumulation, with enhanced clearance of lead in the NTS. Future studies will resolve the mechanisms underpinning tissue-specific lead accumulation. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. The leaded apron revisited: does it reduce gonadal radiation dose in dental radiology

    Energy Technology Data Exchange (ETDEWEB)

    Wood, R.E.; Harris, A.M.; van der Merwe, E.J.; Nortje, C.J. (Ontario Cancer Institute, Princess Margaret Hospital, Toronto (Canada))

    1991-05-01

    A tissue-equivalent anthropomorphic human phantom was used with a lithium fluoride thermoluminescent dosimetry system to evaluate the radiation absorbed dose to the ovarian and testicular region during dental radiologic procedures. Measurements were made with and without personal lead shielding devices consisting of thyroid collar and apron of 0.25 mm lead thickness equivalence. The radiation absorbed dose with or without lead shielding did not differ significantly from control dosimeters in vertex occlusal and periapical views (p greater than 0.05). Personal lead shielding devices did reduce gonadal dose in the case of accidental exposure (p less than 0.05). A leaded apron of 0.25 mm lead thickness equivalent was permeable to radiation in direct exposure testing.

  5. The leaded apron revisited: does it reduce gonadal radiation dose in dental radiology

    International Nuclear Information System (INIS)

    Wood, R.E.; Harris, A.M.; van der Merwe, E.J.; Nortje, C.J.

    1991-01-01

    A tissue-equivalent anthropomorphic human phantom was used with a lithium fluoride thermoluminescent dosimetry system to evaluate the radiation absorbed dose to the ovarian and testicular region during dental radiologic procedures. Measurements were made with and without personal lead shielding devices consisting of thyroid collar and apron of 0.25 mm lead thickness equivalence. The radiation absorbed dose with or without lead shielding did not differ significantly from control dosimeters in vertex occlusal and periapical views (p greater than 0.05). Personal lead shielding devices did reduce gonadal dose in the case of accidental exposure (p less than 0.05). A leaded apron of 0.25 mm lead thickness equivalent was permeable to radiation in direct exposure testing

  6. Can You Lead Me Now? Leading in the Complex World of Homeland Security

    Science.gov (United States)

    2007-09-01

    problem typology and, at the same time, talk of leading as a phenomenological, sense-making process. As John Lawler states: The development of...minutes, two Capitol Police officers were killed and a tourist was wounded. The police wounded Weston and arrested him. At the time, Ramsey and Terry

  7. [Lead poisoning: towards a paleo-epidemiologic re-interpretation?].

    Science.gov (United States)

    Bourdieu, Anne

    2014-01-01

    Lead is a major public health issue. Its use has been increasing since Neolithic times, climaxing in the Ancient Rome and the nineteenth century. Defining the frequency of plumbism before modern times proves to be a difficult matter because of its various and delayed symptoms, and of diagenetic processes affecting bones. After reviewing various methods of lead measurement in bone and tooth, we will expose ways to ascertain lead measurement interpretation in order to estimate the epidemiology of plumbism in ancient times.

  8. Gas cooled leads

    International Nuclear Information System (INIS)

    Shutt, R.P.; Rehak, M.L.; Hornik, K.E.

    1993-01-01

    The intent of this paper is to cover as completely as possible and in sufficient detail the topics relevant to lead design. The first part identifies the problems associated with lead design, states the mathematical formulation, and shows the results of numerical and analytical solutions. The second part presents the results of a parametric study whose object is to determine the best choice for cooling method, material, and geometry. These findings axe applied in a third part to the design of high-current leads whose end temperatures are determined from the surrounding equipment. It is found that cooling method or improved heat transfer are not critical once good heat exchange is established. The range 5 5 but extends over a large of values. Mass flow needed to prevent thermal runaway varies linearly with current above a given threshold. Below that value, the mass flow is constant with current. Transient analysis shows no evidence of hysteresis. If cooling is interrupted, the mass flow needed to restore the lead to its initially cooled state grows exponentially with the time that the lead was left without cooling

  9. Childhood lead poisoning investigations: evaluating a portable instrument for testing soil lead.

    Science.gov (United States)

    Reames, Ginger; Lance, Larrie L

    2002-04-01

    The Childhood Lead Poisoning Prevention Branch of the California Department of Health Services evaluated a portable X-ray fluorescence (XRF) instrument for use as a soil lead-testing tool during environmental investigations of lead-poisoned children's homes. A Niton XRF was used to test soil at 119 sampling locations in the yards of 11 San Francisco Bay Area houses. Niton XRF readings were highly correlated with laboratory results and met the study criteria for an acceptable screening method. The data suggest that the most health-protective and time-efficient approach to testing for soil lead above regulatory levels is to take either surface readings or readings of a test cup of soil prepared by grinding with a mortar and pestle. The advantage of the test cup method is that the test cup with soil may be submitted to a laboratory for confirmatory analysis.

  10. Finding time over time: Longitudinal links between employed mothers' work-family conflict and time profiles.

    Science.gov (United States)

    Lee, Soomi; McHale, Susan M; Crouter, Ann C; Hammer, Leslie B; Almeida, David M

    2017-08-01

    Drawing upon the Work-Home Resources model (ten Brummelhuis & Bakker, 2012), this study examined the links between work-family conflict and employed mothers' profiles of time resources for work and parenting roles. Using a person-centered latent profile approach, we identified 3 profiles of time use and perceived time adequacy in a sample of mothers employed in the extended-care industry (N = 440): a Work-Oriented profile, characterized by spending relatively more time at work, perceiving lower time adequacy for work, spending less time with children, and perceiving lower time adequacy for children; a Parenting-Oriented profile, characterized by the opposite pattern; and a Role-Balanced profile, characterized by average levels across the 4 dimensions. Mothers in the Work-Oriented profile reported greater work-to-family conflict and family to-work conflict than those in the Role-Balanced and Parenting-Oriented profiles. Greater work-to-family conflict was linked to membership in the Work-Oriented profile, net of personal, family, and work characteristics. Longitudinal latent profile transition analysis showed that increases in work-to-family conflict across 12 months were linked to greater odds of moving toward the Work-Oriented profile (relative to staying in the same profile), whereas decreases in work-to-family conflict were linked to greater odds of moving toward the Parenting-Oriented profile. Results illuminate the heterogeneity in how employed mothers perceive and allocate time in work and parenting roles and suggest that decreasing work-to-family conflict may preserve time resources for parenting. Intervention efforts should address ways of increasing employees' family time resources and decreasing work-family conflict. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  11. The lead and lead-acid battery industries during 2002 and 2007 in China

    Energy Technology Data Exchange (ETDEWEB)

    Chen, H.Y.; Li, A.J.; Finlow, D.E. [Key Lab of Electrochemical Technology on Energy Storage and Power Generation in Guangdong Universities, School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China)

    2009-06-01

    In the past 15 years, the center of the international lead market has shifted to China. China has become the largest producer of raw and refined lead, plus the largest consumer. This paper reviews the status of the lead and lead-acid battery industries in China, including lead mining, lead refining, secondary lead production, the lead-acid battery industry, new opportunities for lead-acid batteries, and the environmental problems associated with lead and lead-acid batteries. The output of raw and refined lead has increased annually in China, and now accounts for more than 30% of the world total. As a result of a change in the Chinese government's policy regarding the export of lead, plus an increase in the price of lead, the profits of Chinese lead manufacturers were significantly reduced, the trade deficit of the Chinese lead industry increased, the operating rates of lead smelter enterprises greatly reduced, and some small enterprises were forced to shut down. At the present time, an increasing number of enterprises have begun to produce secondary lead, and the scale of production has expanded from tens of tons to tens of thousands of tons. In 2006, the output of secondary lead in China reached 700,000 tons, but outdated technology and equipment limited development of the secondary lead industry. Because of serious pollution problems, raw material shortages, and fierce price competition in the battery market, changes in the development of the lead-acid battery industry have been dramatic; approximately one thousand medium-sized and small lead-acid battery producers have been closed in the past 3 years. The output of large lead-acid battery enterprises has not been reduced, however, as a result of their manufacturing technology and equipment being comparable to those in other advanced industrial countries. In China, the flourishing development of electric bicycles, electric tricycles, and photovoltaic energy systems should provide ongoing opportunities for

  12. The lead and lead-acid battery industries during 2002 and 2007 in China

    International Nuclear Information System (INIS)

    Chen, H.Y.; Li, A.J.; Finlow, D.E.

    2009-01-01

    In the past 15 years, the center of the international lead market has shifted to China. China has become the largest producer of raw and refined lead, plus the largest consumer. This paper reviews the status of the lead and lead-acid battery industries in China, including lead mining, lead refining, secondary lead production, the lead-acid battery industry, new opportunities for lead-acid batteries, and the environmental problems associated with lead and lead-acid batteries. The output of raw and refined lead has increased annually in China, and now accounts for more than 30% of the world total. As a result of a change in the Chinese government's policy regarding the export of lead, plus an increase in the price of lead, the profits of Chinese lead manufacturers were significantly reduced, the trade deficit of the Chinese lead industry increased, the operating rates of lead smelter enterprises greatly reduced, and some small enterprises were forced to shut down. At the present time, an increasing number of enterprises have begun to produce secondary lead, and the scale of production has expanded from tens of tons to tens of thousands of tons. In 2006, the output of secondary lead in China reached 700,000 tons, but outdated technology and equipment limited development of the secondary lead industry. Because of serious pollution problems, raw material shortages, and fierce price competition in the battery market, changes in the development of the lead-acid battery industry have been dramatic; approximately one thousand medium-sized and small lead-acid battery producers have been closed in the past 3 years. The output of large lead-acid battery enterprises has not been reduced, however, as a result of their manufacturing technology and equipment being comparable to those in other advanced industrial countries. In China, the flourishing development of electric bicycles, electric tricycles, and photovoltaic energy systems should provide ongoing opportunities for the

  13. Great Physicists - The Life and Times of Leading Physicists from Galileo to Hawking

    International Nuclear Information System (INIS)

    Cropper, William H

    2002-01-01

    The author, a former American chemistry professor, has organized his book into nine parts with 29 chapters, covering, in a fairly historical sequence and systematic conceptual progression, all fundamentals of today's physics: i.e., mechanics, thermodynamics, electromagnetism, statistical mechanics, relativity, quantum mechanics, nuclear physics, particle physics, astronomy-astrophysics-cosmology. Obviously, the 20th century (when about 90% of professional physicists of all time worked) assumes with five topics the dominant role in this enterprise. For each topic, a small number (ranging from one to eight) of leading personalities is selected and the biographies of these 29 physicists, including two women (Marie Curie and Lise Meitner), are presented in some detail together with their achievements in the particular topic. Important relevant contributions of other scholars to each topic are also discussed. In addition, Cropper provides each of the topics with a short 'historical synopsis' justifying his selection of key persons. One may argue that concentrating on leading physicists constitutes an old-fashioned approach to displaying the history and contents of fundamental topics in physics. However, the mixture of biographies and explanation of leading contributions given here will certainly serve for a larger public, not just professional physicists and scientists, as a guide through the exciting development of physical ideas and discoveries. In general, the presentation of the material is quite satisfactory (with only few slips, e.g., in the Meitner story, where the author follows too closely a new biography) and gives the essence of the great advances in physics since the 15th century. One notices perhaps the limitation of the author in cases where no biography in English is available - this would also explain the omission of some of the main contributors to atomic and particle physics, such as Arnold Sommerfeld and Hideki Yukawa, or that French or Russian

  14. Primary gamma ray selection in a hybrid timing/imaging Cherenkov array

    Directory of Open Access Journals (Sweden)

    Postnikov E.B.

    2017-01-01

    Full Text Available This work is a methodical study on hybrid reconstruction techniques for hybrid imaging/timing Cherenkov observations. This type of hybrid array is to be realized at the gamma-observatory TAIGA intended for very high energy gamma-ray astronomy (> 30 TeV. It aims at combining the cost-effective timing-array technique with imaging telescopes. Hybrid operation of both of these techniques can lead to a relatively cheap way of development of a large area array. The joint approach of gamma event selection was investigated on both types of simulated data: the image parameters from the telescopes, and the shower parameters reconstructed from the timing array. The optimal set of imaging parameters and shower parameters to be combined is revealed. The cosmic ray background suppression factor depending on distance and energy is calculated. The optimal selection technique leads to cosmic ray background suppression of about 2 orders of magnitude on distances up to 450 m for energies greater than 50 TeV.

  15. Gas, Oil, and Water Production from Jonah, Pinedale, Greater Wamsutter, and Stagecoach Draw Fields in the Greater Green River Basin, Wyoming

    Science.gov (United States)

    Nelson, Philip H.; Ewald, Shauna M.; Santus, Stephen L.; Trainor, Patrick K.

    2010-01-01

    Gas, oil, and water production data were compiled from selected wells in four gas fields in rocks of Late Cretaceous age in southwestern Wyoming. This study is one of a series of reports examining fluid production from tight-gas reservoirs, which are characterized by low permeability, low porosity, and the presence of clay minerals in pore space. Production from each well is represented by two samples spaced five years apart, the first sample typically taken two years after commencement of production. For each producing interval, summary diagrams of oil versus gas and water versus gas production show fluid production rates, the change in rates during five years, the water-gas and oil-gas ratios, and the fluid type. These diagrams permit well-to-well and field-to-field comparisons. Fields producing water at low rates (water dissolved in gas in the reservoir) can be distinguished from fields producing water at moderate or high rates, and the water-gas ratios are quantified. The ranges of first-sample gas rates in Pinedale field and Jonah field are quite similar, and the average gas production rate for the second sample, taken five years later, is about one-half that of the first sample for both fields. Water rates are generally substantially higher in Pinedale than in Jonah, and water-gas ratios in Pinedale are roughly a factor of ten greater in Pinedale than in Jonah. Gas and water production rates from each field are fairly well grouped, indicating that Pinedale and Jonah fields are fairly cohesive gas-water systems. Pinedale field appears to be remarkably uniform in its flow behavior with time. Jonah field, which is internally faulted, exhibits a small spread in first-sample production rates. In the Greater Wamsutter field, gas production from the upper part of the Almond Formation is greater than from the main part of the Almond. Some wells in the main and the combined (upper and main parts) Almond show increases in water production with time, whereas increases

  16. Biogeochemical studies of lead isotopes near a smelter

    International Nuclear Information System (INIS)

    Landrigan, P.J.; Baker, E.L. Jr.; Earl, J.L.; Chow, T.J.

    1975-01-01

    Ninety-nine percent of 1 to 9 year-old children living within 1 mile of a primary lead smelter in Idaho were found to have whole blood lead levels equal to or greater than 40μg/100 ml, a level indicative of excess lead absorption. To define the sources of this lead, isotope ratios were determined in lead from human and environmental samples obtained near the smelter; determinations were performed using a 30-cm radius, solid-source mass spectrometer with an electron multiplier. The Idaho ore is a pre-Cambrian lead deposit with 206 Pb/ 204 Pb = 16.43, 206 Pb = 1.0543 and 206 Pb/ 208 Pb = 0.4518. An ingot smelted in 1974 showed isotope ratios of 206 Pb/ 204 Pb = 17.66, 206 Pb/ 207 Pb = 1.1312 and 206 Pb/ 208 Pb = 0.4694, indicating a mixture of ore sources. Three surface soil samples from within 2 miles of the smelter had lead ratios similar to those in the ingot. A fourth soil sample from beside an interstate highway 32 miles east of the smelter showed different ratios: 206 Pb/ 204 Pb = 18.47, 206 Pb/ 207 Pb = 1.1826 and 206 Pb/ 208 Pb = 0.4823. Aerosol samples collected from October 4, 1974, to February 1, 1975, near the smelter showed considerable variation in ratios; these variations resulted from smelting of ores from differing sources

  17. The perceptions of inquiry held by greater Houston area science supervisors

    Science.gov (United States)

    Aoki, Jon Michael

    The purpose of this study was to describe the perceptions of inquiry held by responding greater Houston area science supervisors. Leading science organizations proposed that students might be better served if students are mentally and physically engaged in the process of finding out about natural phenomena rather than by didactic modes of teaching and learning. During the past fifty years, inquiry-based instruction has become a significant theme of new science programs. Students are more likely to make connections between classroom exercises and their personal lives through the use of inquiry-based instruction. Learning becomes relevant to students. Conversely, traditional science instruction often has little or no connection to students' everyday lives (Papert, 1980). In short, inquiry-based instruction empowers students to become independent thinkers. The utilization of inquiry-based instruction is essential to a successful reform in science education. However, a reform's success is partly determined by the extent to which science supervisors know and understand inquiry and consequently promote its integration in the district's science curricula. Science supervisors have the role of providing curriculum and instructional support to science teachers and for implementing science programs. There is a fundamental need to assess the perceptions of inquiry held by greater Houston area science supervisors. Science supervisor refers to a class of job titles that include department chairperson, science specialist, science consultant, and science coordinator. The target population was greater Houston area science supervisors in Texas. This study suggests that there are three major implications for educational practice. First, there is the implication that responding greater Houston area science supervisors need an inclusive perception of inquiry. Second, responding greater Houston area science supervisors' perception of inquiry may affect the perceptions and understandings

  18. Bacterial Colonization of Disposable Soft Contact Lenses Is Greater during Corneal Infiltrative Events than during Asymptomatic Extended Lens Wear

    Science.gov (United States)

    Sankaridurg, Padmaja R.; Sharma, Savitri; Willcox, Mark; Naduvilath, Thomas J.; Sweeney, Deborah F.; Holden, Brien A.; Rao, Gullapalli N.

    2000-01-01

    Microorganisms, especially gram-negative bacteria, are considered to play a role in the etiology of certain corneal infiltrative events (CIEs) observed during soft contact lens wear. This study explored the possibility of microbial colonization of soft contact lenses as a risk factor leading to CIEs. In a clinical trial conducted from March 1993 to January 1996, 330 subjects wore disposable soft contact lenses on a 6-night extended-wear and disposal schedule. During this period, 4,321 lenses (118 during CIEs; 4,203 during asymptomatic lens wear) were recovered aseptically and analyzed for microbial colonization. A greater percentage of lenses were free from microbial colonization during asymptomatic wear than during CIEs (42 versus 23%; P bacteria, gram-negative bacteria and fungi was greater during CIEs than during asymptomatic lens wear (P bacteria were isolated most frequently and were usually normal external ocular microbiota. Of the gram-positive bacteria, the incidence of Streptococcus pneumoniae was greater during CIE than during asymptomatic wear (7.6 versus 0.6%; P bacteria were seen in few cases during asymptomatic wear, their incidence during CIE in comparison to asymptomatic wear was substantial and significant (23.7 versus 3.8%; P bacteria or S. pneumoniae. Colonization of soft contact lenses with pathogenic bacteria, especially gram-negative bacteria and S. pneumoniae, appears to be a significant risk factor leading to CIE. PMID:11101574

  19. First results of U-Pb dating of metamorphic rocks of the Greater Antilles arc: age of the Mabujina complex (Cuba)

    International Nuclear Information System (INIS)

    Bibikova, E.V.; Somin, M.L.; Gracheva, T.V.; Makarov, V.A.; Mil'yan, G.; Shukolyukov, Yu.A.; AN SSSR, Moscow

    1988-01-01

    U-Pb-dating of zircons, entering the composition of metamorphic rocks of the Mabujina complex, was conducted in order to solve the problem concerming the place of metamorphic complexes in the structure and tectonic evolution of the Greater Antilles arc. The accuracy of uranium and lead determination was equal to ± 1%, the accuracy of lead isotopic ratio determination with the use of TSN-206A mass-spectrometer- ±0.15%. Isotope data showed, that all examined zircons crystallized about 100 mil. years ago

  20. Survey of current lead use, handling, hygiene, and contaminant controls among New Jersey industries.

    Science.gov (United States)

    Blando, James D; Lefkowitz, Daniel K; Valiante, David; Gerwel, Barbara; Bresnitz, Eddy

    2007-08-01

    In 2003, a chemical handling and use survey was mailed to New Jersey employers identified as currently using lead in their industrial processes. This survey was used to ascertain characteristics about lead use, handling, and protection of employees during manufacturing operations. The survey included a diverse group of current lead users with a total lead use range from less than 1 pound to more than 63 million pounds of lead per year. The survey allowed for a comprehensive characterization of hazards and protective measures associated with this metal, still commonly used in many products and industrial processes. Forty-five surveys were returned by companies that are listed in the New Jersey Adult Blood Lead Registry, which is part of the New Jersey Adult Blood Lead Epidemiology and Surveillance (ABLES) program. This program records and investigates cases of adults with greater than 25 mu g/dL of lead in their blood; most cases are related to occupational exposures. This survey found that greater than 25% of these surveyed companies with significant potential for lead exposure did not employ commonly used and basic industrial hygiene practices. In addition, the survey found that 24% of these companies had not conducted air sampling within the last 3 years. Air sampling is the primary trigger for compliance with the Occupational Safety and Health Administration (OSHA) general industry lead standard. Only 17% of the companies have ever been cited for a violation of the OSHA lead standard, and only 46% of these companies have ever had an OSHA inspection. State-based surveillance can be a useful tool for OSHA enforcement activities. Elevated blood lead values in adults should be considered as a trigger for required compliance with an OSHA general industry lead standard.

  1. Assessment of realistic nowcasting lead-times based on predictability analysis of Mediterranean Heavy Precipitation Events

    Science.gov (United States)

    Bech, Joan; Berenguer, Marc

    2014-05-01

    Operational quantitative precipitation forecasts (QPF) are provided routinely by weather services or hydrological authorities, particularly those responsible for densely populated regions of small catchments, such as those typically found in Mediterranean areas prone to flash-floods. Specific rainfall values are used as thresholds for issuing warning levels considering different time frameworks (mid-range, short-range, 24h, 1h, etc.), for example 100 mm in 24h or 60 mm in 1h. There is a clear need to determine how feasible is a specific rainfall value for a given lead-time, in particular for very short range forecasts or nowcasts typically obtained from weather radar observations (Pierce et al 2012). In this study we assess which specific nowcast lead-times can be provided for a number of heavy precipitation events (HPE) that affected Catalonia (NE Spain). The nowcasting system we employed generates QPFs through the extrapolation of rainfall fields observed with weather radar following a Lagrangian approach developed and tested successfully in previous studies (Berenguer et al. 2005, 2011).Then QPFs up to 3h are compared with two quality controlled observational data sets: weather radar quantitative precipitation estimates (QPE) and raingauge data. Several high-impact weather HPE were selected including the 7 September 2005 Llobregat Delta river tornado outbreak (Bech et al. 2007) or the 2 November 2008 supercell tornadic thunderstorms (Bech et al. 2011) both producing, among other effects, local flash floods. In these two events there were torrential rainfall rates (30' amounts exceeding 38.2 and 12.3 mm respectively) and 24h accumulation values above 100 mm. A number of verification scores are used to characterize the evolution of precipitation forecast quality with time, which typically presents a decreasing trend but showing an strong dependence on the selected rainfall threshold and integration period. For example considering correlation factors, 30

  2. Neutron CT with a multi-detector system leading to drastical reduction of the measuring time

    International Nuclear Information System (INIS)

    Hehn, G.; Pfister, G.; Schatz, A.; Goebel, J.; Kofler, R.

    1993-09-01

    By means of numerical simulation methods and their verification with measurements it could be shown that such a detector system can be realized for a line beam and 1-2 detectors per cm. With the maximum available beam width of the fast neutron field at the FRM approximately 20 detectors can be used leading to a reduction of the measuring time to 0,5 - 1 hour. A multi detector system for a line beam of thermal neutrons was constructed, tested and used for CT-measurements. This detector system for the measurement of thinner layers with better spatial resolution could be realized. The electronic discrimination between neutrons and gamma rays has been improved. This discrimination was used in all CT-measurements to get transmission values of both kinds of radiation and to reconstruct to complementary CT-images. The use of a polyenergetic radiation causes spectral shifts in the transmission spectrum leading to artifacts in the reconstructed CT-image. The transmission values must be spectral corrected before image reconstruction, because the image artifacts complicate the image evaluation or make it impossible. A new energy selective procedure for the online spectral correction was developed. This method is based on the concept to measure additionally to the integral transmission value his pulse height spectrum and to do the correction depending on the changes in this pulse height spectrum. (orig./HP) [de

  3. Investigation of lead workers for subclinical effects of lead using three performance tests

    Energy Technology Data Exchange (ETDEWEB)

    Milburn, H; Mitran, E; Crockford, G W

    1976-12-01

    Using three performance tests, lead exposed workers were studied for signs of subclinical neurological effects. The three tests were: two flash fusion threshold, a test considered to indicate the level of arousal; reaction time to a touch stimulus and the rate at which hand grip pressure is developed, both influenced by the conduction velocity of the peripheral nerves and impulse transmission across the motor end plates. Sixteen male lead workers were tested and compared with a non-exposed matched control group of fifteen. The occupational history, neurological symptoms and blood lead levels were recorded. The three performance tests revealed no differences between the exposed and the non-exposed groups.

  4. Quantifying lead-time bias in risk factor studies of cancer through simulation.

    Science.gov (United States)

    Jansen, Rick J; Alexander, Bruce H; Anderson, Kristin E; Church, Timothy R

    2013-11-01

    Lead-time is inherent in early detection and creates bias in observational studies of screening efficacy, but its potential to bias effect estimates in risk factor studies is not always recognized. We describe a form of this bias that conventional analyses cannot address and develop a model to quantify it. Surveillance Epidemiology and End Results (SEER) data form the basis for estimates of age-specific preclinical incidence, and log-normal distributions describe the preclinical duration distribution. Simulations assume a joint null hypothesis of no effect of either the risk factor or screening on the preclinical incidence of cancer, and then quantify the bias as the risk-factor odds ratio (OR) from this null study. This bias can be used as a factor to adjust observed OR in the actual study. For this particular study design, as average preclinical duration increased, the bias in the total-physical activity OR monotonically increased from 1% to 22% above the null, but the smoking OR monotonically decreased from 1% above the null to 5% below the null. The finding of nontrivial bias in fixed risk-factor effect estimates demonstrates the importance of quantitatively evaluating it in susceptible studies. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. First-passage time: a conception leading to superstatistics

    Directory of Open Access Journals (Sweden)

    V.V.Ryazanov

    2006-01-01

    Full Text Available To describe the nonequilibrium states of a system we introduce a new thermodynamic parameter -- the lifetime (the first passage time of a system. The statistical distributions that can be obtained out of the mesoscopic description characterizing the behaviour of a system by specifying the stochastic processes are written. Superstatistics, introduced in [Beck C., Cohen E.G.D., Physica A, 2003, 322A, 267] as fluctuating quantities of intensive thermodynamical parameters, are obtained from statistical distribution with lifetime (random time to system degeneracy as thermodynamical parameter (and also generalization of superstatistics.

  6. Solar Atmosphere to Earth's Surface: Long Lead Time dB/dt Predictions with the Space Weather Modeling Framework

    Science.gov (United States)

    Welling, D. T.; Manchester, W.; Savani, N.; Sokolov, I.; van der Holst, B.; Jin, M.; Toth, G.; Liemohn, M. W.; Gombosi, T. I.

    2017-12-01

    The future of space weather prediction depends on the community's ability to predict L1 values from observations of the solar atmosphere, which can yield hours of lead time. While both empirical and physics-based L1 forecast methods exist, it is not yet known if this nascent capability can translate to skilled dB/dt forecasts at the Earth's surface. This paper shows results for the first forecast-quality, solar-atmosphere-to-Earth's-surface dB/dt predictions. Two methods are used to predict solar wind and IMF conditions at L1 for several real-world coronal mass ejection events. The first method is an empirical and observationally based system to estimate the plasma characteristics. The magnetic field predictions are based on the Bz4Cast system which assumes that the CME has a cylindrical flux rope geometry locally around Earth's trajectory. The remaining plasma parameters of density, temperature and velocity are estimated from white-light coronagraphs via a variety of triangulation methods and forward based modelling. The second is a first-principles-based approach that combines the Eruptive Event Generator using Gibson-Low configuration (EEGGL) model with the Alfven Wave Solar Model (AWSoM). EEGGL specifies parameters for the Gibson-Low flux rope such that it erupts, driving a CME in the coronal model that reproduces coronagraph observations and propagates to 1AU. The resulting solar wind predictions are used to drive the operational Space Weather Modeling Framework (SWMF) for geospace. Following the configuration used by NOAA's Space Weather Prediction Center, this setup couples the BATS-R-US global magnetohydromagnetic model to the Rice Convection Model (RCM) ring current model and a height-integrated ionosphere electrodynamics model. The long lead time predictions of dB/dt are compared to model results that are driven by L1 solar wind observations. Both are compared to real-world observations from surface magnetometers at a variety of geomagnetic latitudes

  7. Sexual predators, energy development, and conservation in greater Yellowstone.

    Science.gov (United States)

    Berger, Joel; Beckmann, Jon P

    2010-06-01

    In the United States, as elsewhere, a growing debate pits national energy policy and homeland security against biological conservation. In rural communities the extraction of fossil fuels is often encouraged because of the employment opportunities it offers, although the concomitant itinerant workforce is often associated with increased wildlife poaching. We explored possible positive and negative factors associated with energy extraction in the Greater Yellowstone Ecosystem (GYE), an area known for its national parks, intact biological diversity, and some of the New World's longest terrestrial migrations. Specifically, we asked whether counties with different economies-recreation (ski), agrarian (ranching or farming), and energy extractive (petroleum)-differed in healthcare (gauged by the abundance of hospital beds) and in the frequency of sexual predators. The absolute and relative frequency of registered sex offenders grew approximately two to three times faster in areas reliant on energy extraction. Healthcare among counties did not differ. The strong conflation of community dishevel, as reflected by in-migrant sexual predators, and ecological decay in Greater Yellowstone is consistent with patterns seen in similar systems from Ecuador to northern Canada, where social and environmental disarray exist around energy boomtowns. In our case, that groups (albeit with different aims) mobilized campaigns to help maintain the quality of rural livelihoods by protecting open space is a positive sign that conservation can matter, especially in the face of rampant and poorly executed energy extraction projects. Our findings further suggest that the public and industry need stronger regulatory action to instill greater vigilance when and where social factors and land conversion impact biological systems.

  8. Determinants of blood-lead levels in children in Callao and Lima metropolitan area

    Directory of Open Access Journals (Sweden)

    Espinoza Rocío

    2003-01-01

    Full Text Available OBJECTIVES: To determine blood lead levels in urban populations of children (n=2 510 and women (n=874 in the early postpartum in certain districts of Lima and Callao, and to correlate those levels with particular exposures. MATERIAL AND METHODS: Between July 1998 and January 1999 cross sectional study was conducted. The study population was selected using three sampling strategies in the government operated school system and from public pediatric and maternity hospitals at Lima and Callao, Peru. Study personnel were trained to collect finger stick blood samples with a protocol that minimizes external lead contamination. Lead determinations in blood and environmental samples were performed at the study site using portable anodic striping voltamenters. To determine the simultaneous effects of different predictors on blood lead levels, multivariate regression models were used to estimate adjusted mean differences. RESULTS: The mean blood lead level in the children studied was 9.9 µg/dl ranging from I µg/dl to 64 µg/dl with 29% of the children displaying values greater than 10 µg/dl and 9.4% at levels greater than 20 µg/dl. Among the women, the mean was 3.5 µg/dl (SD=2.4 µg/dl, and 2.4% (n=21 displayed levels greater than 10 µg/dl. Important differences were observed between the sample locations, and the highest levels were documented in the port region near Callao. The mean level of blood lead in this group was 25.6 µg/dl (SD=4.6 µg/dl, while among the rest of the sample it was 7.1 µg/dl (SD=5.1 µg/dl. The presence of a mineral storage area signified a difference in exposure in excess of 13 µg/dl for children living near the port area in contrast to the other children who were not as close to such fixed sources of lead exposure. For the participants in Lima, the risk of showing levels above 10 µg/dl was associated with exposure to high vehicular traffic. CONCLUSIONS: In metropolitan Lima, we conclude that the mean blood lead levels of

  9. Socio-economic considerations of cleaning Greater Vancouver's air

    International Nuclear Information System (INIS)

    2005-08-01

    Socio-economic considerations of better air quality on the Greater Vancouver population and economy were discussed. The purpose of the study was to provide socio-economic information to staff and stakeholders of the Greater Vancouver Regional District (GVRD) who are participating in an Air Quality Management Plan (AQMP) development process and the Sustainable Region Initiative (SRI) process. The study incorporated the following methodologies: identification and review of Canadian, American, and European quantitative socio-economic, cost-benefit, cost effectiveness, competitiveness and health analyses of changes in air quality and measures to improve air quality; interviews with industry representatives in Greater Vancouver on competitiveness impacts of air quality changes and ways to improve air quality; and a qualitative analysis and discussion of secondary quantitative information that identifies and evaluates socio-economic impacts arising from changes in Greater Vancouver air quality. The study concluded that for the Greater Vancouver area, the qualitative analysis of an improvement in Greater Vancouver air quality shows positive socio-economic outcomes, as high positive economic efficiency impacts are expected along with good social quality of life impacts. 149 refs., 30 tabs., 6 appendices

  10. Adjusting Pulse Amplitude During Transcutaneous Electrical Nerve Stimulation Does Not Provide Greater Hypoalgesia.

    Science.gov (United States)

    Bergeron-Vézina, Kayla; Filion, Camille; Couture, Chantal; Vallée, Élisabeth; Laroche, Sarah; Léonard, Guillaume

    2018-03-01

    Transcutaneous electrical nerve stimulation (TENS) is an electrotherapeutic modality commonly used in rehabilitation to relieve pain. Adjusting pulse amplitude (intensity) during TENS treatment has been suggested to overcome nerve habituation. However, it is still unclear if this procedure leads to greater hypoalgesia. The aim of this study was to determine if the hypoalgesic effect of TENS is greater when pulse amplitude is adjusted throughout the TENS treatment session in chronic low-back pain patients. Randomized double-blind crossover study. Recruitment and assessment were conducted at the Clinique universitaire de réadaptation de l'Estrie (CURE) of the Faculty of Medicine and Health Sciences of the Université de Sherbrooke. Twenty-one volunteers with chronic low-back pain were enrolled and completed this investigation. Each patient received two high-frequency TENS treatments on two separate sessions: (1) with adjustment of pulse amplitude and (2) without pulse amplitude adjustment. Pain intensity and unpleasantness were assessed before, during, and after TENS application with a 10 cm visual analog scale. Both TENS conditions (with and without adjustment of intensity) decreased pain intensity and unpleasantness when compared with baseline. No difference was observed between the two stimulation conditions for both pain intensity and unpleasantness. The current results suggest that adjustment of pulse amplitude during TENS application does not provide greater hypoalgesia in individuals with chronic low-back pain. Future studies are needed to confirm these findings in other pain populations.

  11. High Burden of Subclinical Lead Toxicity after Phase Out of Lead from Petroleum in Pakistan.

    Science.gov (United States)

    Majid, Hafsa; Khan, Aysha Habib; Khan, Nadeem Ullah; Siddiqui, Imran; Ghani, Farooq; Jafri, Lena

    2017-12-01

    To evaluate the frequency of subclinical lead toxicity. Cross-sectional study. Department of Pathology and Laboratory Medicine, The Aga Khan University Hospital, Karachi, from January 2011 to December 2014. Analysis of laboratory data for blood lead levels (BLL) was performed. Lead was tested by atomic absorption spectrometer. For all subjects, only initial test results were included while the results of repeated testing were excluded. Exemption was sought from institutional ethical review committee. BLL of 2-10 ug/dl and 10-70 ug/dl in children and adults, respectively were taken as subclinical lead toxicity. Amongst the total number of subjects tested (n=524), 26.5% (n=139) were children (lead level 16.9 ug/dl (36.1-4)] and lower level [4.2 ug/dl (6.8-2.6)] in children with lead levels while most had either subclinical (76%, n=106) or toxic lead levels (8%, n=11). In adults, (55%, n=212) subjects had desired lead levels, and 40% (n=154) and 4.99% (n=19) had subclinical and toxic lead levels. Presence of subclinical lead poisoning even after phasing out of lead petroleum in Pakistanis is alarming, especially in children. A national population-based study to determine the lead status and targeted intervention to identify potential sources is need of the time.

  12. Greater trochanteric pain syndrome diagnosis and treatment.

    Science.gov (United States)

    Mallow, Michael; Nazarian, Levon N

    2014-05-01

    Lateral hip pain, or greater trochanteric pain syndrome, is a commonly seen condition; in this article, the relevant anatomy, epidemiology, and evaluation strategies of greater trochanteric pain syndrome are reviewed. Specific attention is focused on imaging of this syndrome and treatment techniques, including ultrasound-guided interventions. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Minimal invasive epicardial lead implantation: optimizing cardiac resynchronization with a new mapping device for epicardial lead placement.

    Science.gov (United States)

    Maessen, J G; Phelps, B; Dekker, A L A J; Dijkman, B

    2004-05-01

    To optimize resynchronization in biventricular pacing with epicardial leads, mapping to determine the best pacing site, is a prerequisite. A port access surgical mapping technique was developed that allowed multiple pace site selection and reproducible lead evaluation and implantation. Pressure-volume loops analysis was used for real time guidance in targeting epicardial lead placement. Even the smallest changes in lead position revealed significantly different functional results. Optimizing the pacing site with this technique allowed functional improvement up to 40% versus random pace site selection.

  14. [Study on lead absorption in pumpkin by atomic absorption spectrophotometry].

    Science.gov (United States)

    Li, Zhen-Xia; Sun, Yong-Dong; Chen, Bi-Hua; Li, Xin-Zheng

    2008-07-01

    A study was carried out on the characteristic of lead absorption in pumpkin via atomic absorption spectrophotometer. The results showed that lead absorption amount in pumpkin increased with time, but the absorption rate decreased with time; And the lead absorption amount reached the peak in pH 7. Lead and cadmium have similar characteristic of absorption in pumpkin.

  15. Evolution of faster development does not lead to greater fluctuating ...

    Indian Academy of Sciences (India)

    Unknown

    Journal of Genetics, Vol. 80, No. 1, Apri1 ..... Strobeck 1986). Statistical analysis: Selected and control populations with ..... and Industrial Research, Government of India, for financial ... Falconer D. S. 1981 Introduction to quantitative genetics.

  16. Flexible intellectual property rights lead to greater innovation in Africa

    International Development Research Centre (IDRC) Digital Library (Canada)

    2016-04-27

    Apr 27, 2016 ... The network is unique in offering a distinctly African perspective on the global intellectual property and innovation agenda. ... Case studies illustrate this balance: ... Unlocking the potential of Africa's young entrepreneurs.

  17. Probabilistic inference under time pressure leads to a cortical-to-subcortical shift in decision evidence integration.

    Science.gov (United States)

    Oh-Descher, Hanna; Beck, Jeffrey M; Ferrari, Silvia; Sommer, Marc A; Egner, Tobias

    2017-11-15

    Real-life decision-making often involves combining multiple probabilistic sources of information under finite time and cognitive resources. To mitigate these pressures, people "satisfice", foregoing a full evaluation of all available evidence to focus on a subset of cues that allow for fast and "good-enough" decisions. Although this form of decision-making likely mediates many of our everyday choices, very little is known about the way in which the neural encoding of cue information changes when we satisfice under time pressure. Here, we combined human functional magnetic resonance imaging (fMRI) with a probabilistic classification task to characterize neural substrates of multi-cue decision-making under low (1500 ms) and high (500 ms) time pressure. Using variational Bayesian inference, we analyzed participants' choices to track and quantify cue usage under each experimental condition, which was then applied to model the fMRI data. Under low time pressure, participants performed near-optimally, appropriately integrating all available cues to guide choices. Both cortical (prefrontal and parietal cortex) and subcortical (hippocampal and striatal) regions encoded individual cue weights, and activity linearly tracked trial-by-trial variations in the amount of evidence and decision uncertainty. Under increased time pressure, participants adaptively shifted to using a satisficing strategy by discounting the least informative cue in their decision process. This strategic change in decision-making was associated with an increased involvement of the dopaminergic midbrain, striatum, thalamus, and cerebellum in representing and integrating cue values. We conclude that satisficing the probabilistic inference process under time pressure leads to a cortical-to-subcortical shift in the neural drivers of decisions. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. ULTRAFISH: generalization of SUPERFISH to m greater than or equal to 1

    International Nuclear Information System (INIS)

    Gluckstern, R.L.; Holsinger, R.F.; Halbach, K.; Minerbo, G.N.

    1982-01-01

    The present version of the SUPERFISH program computes fundamental and higher order resonant frequencies and corresponding fields of azimuthally symmetric TE and TM modes (m = 0) in an electromagnetic cavity which is a figure of revolution about a longitudinal axis. We have developed the program ULTRAFISH which computes the resonant frequencies and fields in such a cavity for azimuthally asymmetric modes (cos mphi with m greater than or equal to 1). These modes no longer can be characterized as TE and TM and lead to simultaneous equations involving two field components. These are taken for convenience to be rEphi and rHphi, in terms of which all four other field components are expressed. Several different formulations for solving the equations are being investigated

  19. Greater physiological and behavioral effects of interrupted stress pattern compared to daily restraint stress in rats.

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    Full Text Available Repeated stress can trigger a range of psychiatric disorders, including anxiety. The propensity to develop abnormal behaviors after repeated stress is related to the severity, frequency and number of stressors. However, the pattern of stress exposure may contribute to the impact of stress. In addition, the anxiogenic nature of repeated stress exposure can be moderated by the degree of coping that occurs, and can be reflected in homotypic habituation to the repeated stress. However, expectations are not clear when a pattern of stress presentation is utilized that diminishes habituation. The purpose of these experiments is to test whether interrupted stress exposure decreases homotypic habituation and leads to greater effects on anxiety-like behavior in adult male rats. We found that repeated interrupted restraint stress resulted in less overall homotypic habituation compared to repeated daily restraint stress. This was demonstrated by greater production of fecal boli and greater corticosterone response to restraint. Furthermore, interrupted restraint stress resulted in a lower body weight and greater adrenal gland weight than daily restraint stress, and greater anxiety-like behavior in the elevated plus maze. Control experiments demonstrated that these effects of the interrupted pattern could not be explained by differences in the total number of stress exposures, differences in the total number of days that the stress periods encompased, nor could it be explained as a result of only the stress exposures after an interruption from stress. These experiments demonstrate that the pattern of stress exposure is a significant determinant of the effects of repeated stress, and that interrupted stress exposure that decreases habituation can have larger effects than a greater number of daily stress exposures. Differences in the pattern of stress exposure are therefore an important factor to consider when predicting the severity of the effects of repeated

  20. Operational technology for greater confinement disposal

    International Nuclear Information System (INIS)

    Dickman, P.T.; Vollmer, A.T.; Hunter, P.H.

    1984-12-01

    Procedures and methods for the design and operation of a greater confinement disposal facility using large-diameter boreholes are discussed. It is assumed that the facility would be located at an operating low-level waste disposal site and that only a small portion of the wastes received at the site would require greater confinement disposal. The document is organized into sections addressing: facility planning process; facility construction; waste loading and handling; radiological safety planning; operations procedures; and engineering cost studies. While primarily written for low-level waste management site operators and managers, a detailed economic assessment section is included that should assist planners in performing cost analyses. Economic assessments for both commercial and US government greater confinement disposal facilities are included. The estimated disposal costs range from $27 to $104 per cubic foot for a commercial facility and from $17 to $60 per cubic foot for a government facility. These costs are based on average site preparation, construction, and waste loading costs for both contact- and remote-handled wastes. 14 figures, 22 tables

  1. More frequent vaginal orgasm is associated with experiencing greater excitement from deep vaginal stimulation.

    Science.gov (United States)

    Brody, Stuart; Klapilova, Katerina; Krejčová, Lucie

    2013-07-01

    Research indicated that: (i) vaginal orgasm (induced by penile-vaginal intercourse [PVI] without concurrent clitoral masturbation) consistency (vaginal orgasm consistency [VOC]; percentage of PVI occasions resulting in vaginal orgasm) is associated with mental attention to vaginal sensations during PVI, preference for a longer penis, and indices of psychological and physiological functioning, and (ii) clitoral, distal vaginal, and deep vaginal/cervical stimulation project via different peripheral nerves to different brain regions. The aim of this study is to examine the association of VOC with: (i) sexual arousability perceived from deep vaginal stimulation (compared with middle and shallow vaginal stimulation and clitoral stimulation), and (ii) whether vaginal stimulation was present during the woman's first masturbation. A sample of 75 Czech women (aged 18-36), provided details of recent VOC, site of genital stimulation during first masturbation, and their recent sexual arousability from the four genital sites. The association of VOC with: (i) sexual arousability perceived from the four genital sites and (ii) involvement of vaginal stimulation in first-ever masturbation. VOC was associated with greater sexual arousability from deep vaginal stimulation but not with sexual arousability from other genital sites. VOC was also associated with women's first masturbation incorporating (or being exclusively) vaginal stimulation. The findings suggest (i) stimulating the vagina during early life masturbation might indicate individual readiness for developing greater vaginal responsiveness, leading to adult greater VOC, and (ii) current sensitivity of deep vaginal and cervical regions is associated with VOC, which might be due to some combination of different neurophysiological projections of the deep regions and their greater responsiveness to penile stimulation. © 2013 International Society for Sexual Medicine.

  2. Inhibition of hydrocarbon bioremediation by lead in a crude oil-contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Al-Saleh, E.S.; Obuekwe, C. [Kuwait University (Kuwait). Department of Biological Sciences, Microbiology Program

    2005-07-01

    Analyses of soil samples revealed that the level of lead (total or bioavailable) was three-fold greater in crude oil contaminated than in uncontaminated Kuwaiti soils. Investigation of the possible inhibitory effect of lead on hydrocarbon degradation by the soil microbiota showed that the number of hydrocarbon-degrading bacteria decreased with increased levels of lead nitrate added to soil samples, whether oil polluted or not. At 1.0 mg lead nitrate g{sup -1} dry soil, the number of degraders of hexadecane, naphthalene and crude oil declined by 14%, 23% and 53%, respectively. In a similar manner, the degradation and mineralization of different hydrocarbons decreased with increased lead content in cultures, although the decreases were not significantly different (P>0.05). The dehydrogenase activities of soil samples containing hydrocarbons as substrates also declined with an increase in the lead content of soil samples. (author)

  3. Misplaced Inventory and Lead-Time in the Supply Chain: Analysis of Decision-Making on RFID Investment with Service Level

    Directory of Open Access Journals (Sweden)

    Li-Hao Zhang

    2014-01-01

    Full Text Available Radio-frequency identification (RFID, as the key technology of Internet of Things (IoT, has been hailed as a major innovation to solve misplaced inventory and reduce lead-time. Many retailers have been pushing their suppliers to invest this technology. However, its associated costs seem to prohibit its widespread application. This paper analyzes the situation of service level in a retail supply chain, which has resulted from misplaced inventory and lead-time. By newsvendor model, we analyze the difference between with- and without-RFID technologies in service level of centralized and decentralized supply chains, respectively. Then with different service levels, we determine the tag cost thresholds at which RFID technology investment becomes profitable in centralized and decentralized supply chains, respectively. Furthermore, we apply a linear transfer payment coefficient strategy to coordinate with the decentralized supply chain. It is found that whether the adoption of RFID technology improves the service level depends on the cost of RFID tag in the centralized system, but it improves the service level in the decentralized system when only the supplier bears the cost of RFID tag. Moreover, the same cost thresholds of RFID tag with different service levels exist in both the centralized and the decentralized cases.

  4. Greater trochanteric fracture with occult intertrochanteric extension.

    Science.gov (United States)

    Reiter, Michael; O'Brien, Seth D; Bui-Mansfield, Liem T; Alderete, Joseph

    2013-10-01

    Proximal femoral fractures are frequently encountered in the emergency department (ED). Prompt diagnosis is paramount as delay will exacerbate the already poor outcomes associated with these injuries. In cases where radiography is negative but clinical suspicion remains high, magnetic resonance imaging (MRI) is the study of choice as it has the capability to depict fractures which are occult on other imaging modalities. Awareness of a particular subset of proximal femoral fractures, namely greater trochanteric fractures, is vital for both radiologists and clinicians since it has been well documented that they invariably have an intertrochanteric component which may require surgical management. The detection of intertrochanteric or cervical extension of greater trochanteric fractures has been described utilizing MRI but is underestimated with both computed tomography (CT) and bone scan. Therefore, if MRI is unavailable or contraindicated, the diagnosis of an isolated greater trochanteric fracture should be met with caution. The importance of avoiding this potential pitfall is demonstrated in the following case of an elderly woman with hip pain and CT demonstrating an isolated greater trochanteric fracture who subsequently returned to the ED with a displaced intertrochanteric fracture.

  5. Endovascular aneurysm repair simulation can lead to decreased fluoroscopy time and accurately delineate the proximal seal zone.

    Science.gov (United States)

    Kim, Ann H; Kendrick, Daniel E; Moorehead, Pamela A; Nagavalli, Anil; Miller, Claire P; Liu, Nathaniel T; Wang, John C; Kashyap, Vikram S

    2016-07-01

    The use of simulators for endovascular aneurysm repair (EVAR) is not widespread. We examined whether simulation could improve procedural variables, including operative time and optimizing proximal seal. For the latter, we compared suprarenal vs infrarenal fixation endografts, right femoral vs left femoral main body access, and increasing angulation of the proximal aortic neck. Computed tomography angiography was obtained from 18 patients who underwent EVAR at a single institution. Patient cases were uploaded to the ANGIO Mentor endovascular simulator (Simbionix, Cleveland, Ohio) allowing for three-dimensional reconstruction and adapted for simulation with suprarenal fixation (Endurant II; Medtronic Inc, Minneapolis, Minn) and infrarenal fixation (C3; W. L. Gore & Associates Inc, Newark, Del) deployment systems. Three EVAR novices and three experienced surgeons performed 18 cases from each side with each device in randomized order (n = 72 simulations/participant). The cases were stratified into three groups according to the degree of infrarenal angulation: 0° to 20°, 21° to 40°, and 41° to 66°. Statistical analysis used paired t-test and one-way analysis of variance. Mean fluoroscopy time for participants decreased by 48.6% (P time decreased by 33.8% (P zone coverage in highly angulated aortic necks was significantly decreased. The infrarenal device resulted in mean aortic neck zone coverage of 91.9%, 89.4%, and 75.4% (P zone coverage. The side of femoral access for the main body did not influence proximal seal zone coverage regardless of infrarenal angulation. Simulation of EVAR leads to decreased fluoroscopy times for novice and experienced operators. Side of femoral access did not affect precision of proximal endograft landing. The angulated aortic neck leads to decreased proximal seal zone coverage regardless of infrarenal or suprarenal fixation devices. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

  6. The usefulness of panoramic radiography using a lead ruler for dental implant planning

    International Nuclear Information System (INIS)

    Lee, Sang Hee; Lee, Seong Geun; Kim, Sung Min; Oh, Kyong Seung; Huh, Jin Do; Joh, Young Duk

    2000-01-01

    If damage to the neurovascular bundle of the mandibular canal during dental implant surgery of the mandible is to be prevented, accurate measurement of the distance between the alveolar crest and the mandibular canal, as seen on panoramic radiographs, is important. The purpose of this study was to compare the accuracy of panoramic radiography using a lead ruler with that of computed tomography for the measurement of the distance between the alveolar crest and superior border of the mandibular canal and to evaluate the usefulness of panoramic radiography using a lead ruler. For control study, panoramic radiography of the dry mandible was undertaken using a lead ruler, and computed tomography was added. The distances between the alveolar crest and the superior border of the mandibular canal and between the alveolar crest and the lowest border of the body of the mandible were measured at the level of the 2nd premolar to the 3rd molar. These measurements were compared with actual measurements of the dry mandible in the same areas. The cases of 87 patients (49 men, 38 women; age range, 20-84 (mean, 42) years) who had undergone panoramic radiography using a lead ruler were reviewed. They were categorized according to sex, the presence of teeth, and whether under or over 50 years of age. All measurements were compared and analyzed using the Student t-test. Measured values obtained from a panoramic radiograph using a lead ruler (magnification:100.32% ± 5.92) and from a computed tomograph (magnification:100.22 ± 5.55) deviated less from actual measurements on the dry mandible (p greater than 0.05). The distance from the 2nd premolar to the 3rd molar was greater in male adults (19.62 mm ± 3.95) than in female (17.54 mm ± 4.04) (p less than 0.05), except the 3rd molar. In addition, the distance was greater in dentulous patients (18.81 mm ± 3.33) than in edentulous (16.23 mm ± 1.75) (p less than 0.05), except the 3rd molar. There was, however, no significant difference

  7. Lead concentration in meat from lead-killed moose and predicted human exposure using Monte Carlo simulation.

    Science.gov (United States)

    Lindboe, M; Henrichsen, E N; Høgåsen, H R; Bernhoft, A

    2012-01-01

    Lead-based hunting ammunitions are still common in most countries. On impact such ammunition releases fragments which are widely distributed within the carcass. In Norway, wild game is an important meat source for segments of the population and 95% of hunters use lead-based bullets. In this paper, we have investigated the lead content of ground meat from moose (Alces alces) intended for human consumption in Norway, and have predicted human exposure through this source. Fifty-two samples from different batches of ground meat from moose killed with lead-based bullets were randomly collected. The lead content was measured by atomic absorption spectroscopy. The lead intake from exposure to moose meat over time, depending on the frequency of intake and portion size, was predicted using Monte Carlo simulation. In 81% of the batches, lead levels were above the limit of quantification of 0.03 mg kg(-1), ranging up to 110 mg kg(-1). The mean lead concentration was 5.6 mg kg(-1), i.e. 56 times the European Commission limit for lead in meat. For consumers eating a moderate meat serving (2 g kg(-1) bw), a single serving would give a lead intake of 11 µg kg(-1) bw on average, with maximum of 220 µg kg(-1) bw. Using Monte Carlo simulation, the median (and 97.5th percentile) predicted weekly intake of lead from moose meat was 12 µg kg(-1) bw (27 µg kg(-1) bw) for one serving per week and 25 µg kg(-1) bw (45 µg kg(-1) bw) for two servings per week. The results indicate that the intake of meat from big game shot with lead-based bullets imposes a significant contribution to the total human lead exposure. The provisional tolerable weekly intake set by the World Health Organization (WHO) of 25 µg kg(-1) bw is likely to be exceeded in people eating moose meat on a regular basis. The European Food Safety Authority (EFSA) has recently concluded that adverse effects may be present at even lower exposure doses. Hence, even occasional consumption of big game meat with lead levels as

  8. Influence of experimental distemper infection on the distribution of lead in dogs previously subacutely intoxicated with lead carbonate

    Energy Technology Data Exchange (ETDEWEB)

    White, D.J.; Marshall, A.J.; McLeod, S.

    1975-01-01

    The ability of experimental canine distemper infection to mobilize body lead deposits has been studied in Beagle dogs previously subacutely intoxicated with lead carbonate. For comparative purposes dogs were included which had either received lead only or distemper only or remained undosed. It was found that in dogs predosed with lead, distemper infection resulted in a significant increase in lead levels in blood and urine; this coincided with the peak body temperatures reached on the third day post infection. It was also found that the lead content of the liver and bone of these dogs was considerably higher than that of dogs receiving lead alone; at the same time bone phosphorus showed a marked decrease while bone calcium values remained similar to undosed controls.

  9. Lead poisoning in ancient Rome | Retief | Acta Theologica

    African Journals Online (AJOL)

    Lead was known to the ancients from at least the 4th millennium BC, but its use increased markedly during Roman times, to the extent that it became a health hazard. Mines and foundry furnaces caused air pollution; lead was extensively used in plumbing; domestic utensils were made of lead and pewter, and lead salts ...

  10. The Greater Sekhukhune-CAPABILITY outreach project.

    Science.gov (United States)

    Gregersen, Nerine; Lampret, Julie; Lane, Tony; Christianson, Arnold

    2013-07-01

    The Greater Sekhukhune-CAPABILITY Outreach Project was undertaken in a rural district in Limpopo, South Africa, as part of the European Union-funded CAPABILITY programme to investigate approaches for capacity building for the translation of genetic knowledge into care and prevention of congenital disorders. Based on previous experience of a clinical genetic outreach programme in Limpopo, it aimed to initiate a district clinical genetic service in Greater Sekhukhune to gain knowledge and experience to assist in the implementation and development of medical genetic services in South Africa. Implementing the service in Greater Sekhukhune was impeded by a developing staff shortage in the province and pressure on the health service from the existing HIV/AIDS and TB epidemics. This situation underscores the need for health needs assessment for developing services for the care and prevention of congenital disorders in middle- and low-income countries. However, these impediments stimulated the pioneering of innovate ways to offer medical genetic services in these circumstances, including tele-teaching of nurses and doctors, using cellular phones to enhance clinical care and adapting and assessing the clinical utility of a laboratory test, QF-PCR, for use in the local circumstances.

  11. Model Penjadwalan Pengiriman Pasokan pada Strategi Multi-Supplier dengan Variasi Harga dan Lead Time untuk Permintaan Stokastik

    Directory of Open Access Journals (Sweden)

    Nur Aini Masruroh

    2015-06-01

    Full Text Available Multi-supplier is one of the strategies to minimize holding cost and average stock-out cost as long as to stabilize the supply of raw materials. The common problems that the firms may face when applying the multi-supplier strategy are determining the right schedule and quantity ordered for each supplier. Complexity of the problem increases with the facts that each supplier may have different parameters, demand is uncertain, and the firms’ constraints. Thus, this research is done to answer two main objectives: (1 to determine the optimum safety time (minimum raw material inventory to prevent the stockout due to the demand uncertainty and (2 to determine the right schedule and quantity ordered for each supplier considering the different suppliers parameters: price, lead time, and supply capacity. The problem is modeled in Mixed Integer Linear Programming with total minimum inventory cost as the objective. With the aim of testing the model, a case of multinational company that apply the multi-supplier strategy is used.

  12. Mass balance for lead in the California South Coast Air Basin: An update

    International Nuclear Information System (INIS)

    Lankey, R.L.; Davidson, C.I.; McMichael, F.C.

    1998-01-01

    A mass balance for lead for the year 1989 in the South Coast Air Basin has inputs to the atmosphere of 600 ± 190 kg/day and outputs of 580 ± 160 kg/day, showing rough agreement. Stationary sources are responsible for only about 5% of the total lead emissions. The bulk of the lead is emitted from vehicles using leaded gasoline (37%) and unleaded gasoline (15%), as well as from resuspension of previously deposited lead on roads (43%). Over half of the total emitted lead deposits on roads and nearby soil, while about one-third is carried out of the basin by wind. A small amount, less than 10%, is deposited on surfaces throughout the basin. These percentages are approximately the same as those in a mass balance for the same region calculated for 1972, when lead emissions from leaded gasoline were about a factor of 70 greater than leaded gas emissions in 1989. When the lead emissions re used as inputs o a simple continuously stirred flow reactor model for the basin, reasonable, agreement is obtained between calculated and measured concentrations

  13. Lead Thickness Measurements

    International Nuclear Information System (INIS)

    Rucinski, R.

    1998-01-01

    The preshower lead thickness applied to the outside of D-Zero's superconducting solenoid vacuum shell was measured at the time of application. This engineering documents those thickness measurements. The lead was ordered in sheets 0.09375-inch and 0.0625-inch thick. The tolerance on thickness was specified to be +/- 0.003-inch. The sheets all were within that thickness tolerance. The nomenclature for each sheet was designated 1T, 1B, 2T, 2B where the numeral designates it's location in the wrap and 'T' or 'B' is short for 'top' or 'bottom' half of the solenoid. Micrometer measurements were taken at six locations around the perimeter of each sheet. The width,length, and weight of each piece was then measured. Using an assumed pure lead density of 0.40974 lb/in 3 , an average sheet thickness was calculated and compared to the perimeter thickness measurements. In every case, the calculated average thickness was a few mils thinner than the perimeter measurements. The ratio was constant, 0.98. This discrepancy is likely due to the assumed pure lead density. It is not felt that the perimeter is thicker than the center regions. The data suggests that the physical thickness of the sheets is uniform to +/- 0.0015-inch.

  14. Continued warming could transform Greater Yellowstone fire regimes by mid-21st century

    Science.gov (United States)

    Anthony L. Westerling; Monica G. Turner; Erica A. H. Smithwick; William H. Romme; Michael G. Ryan

    2011-01-01

    Climate change is likely to alter wildfire regimes, but the magnitude and timing of potential climate-driven changes in regional fire regimes are not well understood. We considered how the occurrence, size, and spatial location of large fires might respond to climate projections in the Greater Yellowstone ecosystem (GYE) (Wyoming), a large wildland ecosystem dominated...

  15. INFLUENCE OF SNOWFALL ON BLOOD LEAD LEVELS OF FREE-FLYING BALD EAGLES (HALIAEETUS LEUCOCEPHALUS) IN THE UPPER MISSISSIPPI RIVER VALLEY.

    Science.gov (United States)

    Lindblom, Ronald A; Reichart, Letitia M; Mandernack, Brett A; Solensky, Matthew; Schoenebeck, Casey W; Redig, Patrick T

    2017-10-01

    Lead poisoning of scavenging raptors occurs primarily via consumption of game animal carcasses containing lead, which peaks during fall firearm hunting seasons. We hypothesized that snowfall would mitigate exposure by concealing carcasses. We categorized blood lead level (BLL) for a subsample of Bald Eagles (Haliaeetus leucocephalus) from the Upper Mississippi River Valley and described BLL with respect to age, sex, and snowfall. We captured Bald Eagles overwintering in the Upper Mississippi River Valley (n=55) between December 1999 and January 2002. Individual BLL ranged from nondetectable to 335 μg/dL, with 73% of the samples testing positive for acute exposure to lead. Eagle BLL did not significantly differ between age or sex, but levels were higher immediately following the hunting season, and they were lower when the previous month's snowfall was greater than 11 cm. This study suggests a window of time between the white-tailed deer (Odocoileus virginianus) hunting season and the onset of snow when the population experienced peak exposure to lead. Combining these findings with existing research, we offer a narrative of the annual lead exposure cycle of Upper Mississippi River Valley Bald Eagles. These temporal associations are necessary considerations for accurate collection and interpretation of BLL.

  16. Examination of lead concentrations in new decorative enamel paints in four countries with different histories of activity in lead paint regulation

    International Nuclear Information System (INIS)

    Clark, C. Scott; Kumar, Abhay; Mohapatra, Piyush; Rajankar, Prashant; Nycz, Zuleica; Hambartsumyan, Amalia; Astanina, Lydia; Roda, Sandy; Lind, Caroline; Menrath, William; Peng, Hongying

    2014-01-01

    current study and those available from other studies 24 of 28 paints from major brands in India decreased from high concentrations to 90 ppm or lower. Since lead concentrations in golden yellow paints from these brands were found to decrease to ≤90 ppm, it is possible that all 28 of these paints now contain ≤90 ppm since yellow paints usually have the highest lead concentrations. Other brands in Brazil and India that have been analyzed only one time had lead concentrations up to 59,000 ppm and 134,000 ppm, respectively. Less than one-third of the paints had notations on their labels with information about lead content and these were sometimes inaccurate. The label from one brand indicating “no added lead” contained paint with 134,000 ppm lead, the highest found in this study. Three percent (3 of 98) of the paints with surface lead loading that did not exceed 2 µg/cm 2 , the limit established by the Consumer Product Safety Improvement Act for small areas on toys, contained greater than 90 ppm lead and thus were false negatives. Of the new paint samples that contained ≤600 ppm, 88% contained ≤90 ppm. Of the samples that contained ≤90 ppm, 97% contained ≤45 ppm and 92% contained ≤15 ppm. Based on these data it appears to be technically feasible to manufacture paints containing ≤90 ppm and in many cases to produce paints that have lead concentrations that do not exceed 15 ppm. - Highlights: • Brazilian paints with high lead (avg. 36,000 ppm) contained <9 ppm after regulation. • Lead in major Indian paint brands decreased to low levels by efforts of NGOs/others. • Most paints with lead ≤600 ppm also are ≤90 ppm and many also ≤15 ppm. • At the CPSIA limit of 2 µg Pb/cm 2 for small areas on toys, 3% exceeded 90 ppm lead. • Most paint brands in Armenia and Kazakhstan based/manufactured outside the country

  17. Evaluation of lead-iron-phosphate glass as a high-level waste form

    International Nuclear Information System (INIS)

    Chick, L.A.; Bunnell, L.R.; Strachan, D.M.; Kissinger, H.E.; Hodges, F.N.

    1986-01-01

    The lead-iron-phosphate nuclear waste glass developed at Oak Ridge National Laboratory (ORNL) was evaluated for its potential as an improvement over the current reference waste form, borosilicate glass. Vitreous lead-iron-phosphate glass appears to have substantially better chemical durability than borosilicate glass. However, severe crystallization leading to deteriorated chemical durability would result if this glass were poured into large canisters as is presently done with borosilicate glass. Cesium leach rates from this crystallized material are orders of magnitude greater than those from borosilicate glass. Therefore, in order to realize the performance advantages of the lead-iron-phosphate material in a nuclear waste form, it would be necessary to process it so that it is rapidly cooled, thus retaining its vitreous structure. 22 refs., 4 figs., 4 tabs

  18. An Influence Study of Hydrogen Evolution Characteristics on the Negative Strap Corrosion of Lead Acid Battery

    Directory of Open Access Journals (Sweden)

    Zhong Guobin

    2015-01-01

    Full Text Available Negative strap corrosion is an important reason for the failure of valve regulated lead acid battery. This paper selected the Pb-Sb alloy material and Pb-Sn alloy material, made an investigation on the negative corrosion resistance and hydrogen evolution of these two alloy materials by scanning electron microscope analysis, metallographic analysis, chemical study and linear sweep voltammetry, and discussed the influence of lead alloy hydrogen evolution on the negative strap corrosion. The results showed that the hydrogen evolution reaction rates of the alloys had an impact on the corrosion areas with the maximum thickness of the alloys and the depth of corrosion layers. Greater hydrogen evolution reaction rate can lead to shorter distance between the corrosion area with the maximum thickness and the liquid level; whereas the greater corrosion layer thickness can bring aggravated risk of negative strap corrosion failure.

  19. Increasing Time and Enriching Learning for Greater Equity in Schools: Perspective from Two Community Funders

    Science.gov (United States)

    Lopez, Janet; Rivera, Peter

    2015-01-01

    Foundations across the country engage in grantmaking to eliminate the opportunity and achievement gaps in K-12 public schools. Many of the strategies and investments that funders have supported in recent years focus not only on "more time" but also on "better use of time" in schools. This better use of time centers on outcomes…

  20. Medição e controle do tempo de atravessamento em um sistema de manufatura Measurement and control of lead-time in a manufacturing system

    Directory of Open Access Journals (Sweden)

    Miguel Afonso Sellitto

    2008-04-01

    Full Text Available Este artigo apresenta um método para a medição do tempo de atravessamento e do inventário em processo em manufatura. A medição foi usada em processo de controle organizacional de manufatura, cuja variável controlada foi o tempo de atravessamento de ordens. Tal controle pode ser útil em estratégias de manufatura em que a competição é baseada no uso do tempo, a TBC (time-based competition. Apresentou-se o método de medição, que inclui elementos da teoria das filas, e considerações para a simplificação de arranjos produtivos de manufatura. Para testar e refinar o método, estudou-se um caso em manufatura calçadista. Foram coletados dados de remessas e obtido, por análise estatística e simulação computacional, o comportamento da variável aleatória tempo de atravessamento de remessas. Como a medição foi inferior ao objetivo de desempenho, partiu-se para o controle, fazendo um diagnóstico que apontou efeitos indesejáveis observados que foram endereçados por ações corretivas implementadas. Para verificar a eficácia das ações, nova coleta foi feita. Desta vez, o objetivo de desempenho das entregas foi atendido, fechando um ciclo de controle. Os resultados foram discutidos, chegando-se a conclusões e alternativas de continuidade.This paper presents a method for the measurement of the lead-time and work-in-process in manufacturing. The measurement was used in an organizational control process in manufacturing, in which the controlled variate was the order lead-time. This kind of control can be useful in manufacture strategies formulated to compete in TBC (time-based competition. We presented the method, who includes elements from the queuing theory, and concerns about simplifying complex manufacturing arrays, in order to facilitate the analysis. In order to test and refine the method, we studied a case in a footwear manufacture system. We collected data from orders and, by statistical techniques and computational

  1. Processes Leading to Beaded Channels Formation in Central Yakutia

    Science.gov (United States)

    Tarbeeva, A. M.; Lebedeva, L.; Efremov, V. S.; Krylenko, I. V.; Surkov, V. V.

    2017-12-01

    Beaded channels, consisting of deepened and widened pools and connecting narrow runs, are common fluvial forms in permafrost regions. Recent studies have shown that beaded channels are very important for connecting alluvial rivers with headwater lakes allowing fish passage and foraging habitats, as well as regulating river runoff. Beaded channels are known as typical thermokarst landforms; however, there is no evidence of their origin and formative processes. Geomorphological analyzes of beaded channels have been completed in several permafrost regions including field observations of Shestakovka River in Central Yakutia. The study aims to recognize the modern exogenic processes and formative mechanisms of beaded river channels. We show that beaded channel of Shestakovka River form in the perennially frozen sand with low ice content, leading us to hypothesize that thermokarst is not the main process of formation. Due to the significant volume of water, the pools don't freeze over entirely during winters, even under harsh climatic conditions. As a result, lenses of pressurized water remain under surface ice underlain by perennially thawed sediments. The presence of thawed sediments under the pools and frozen sediments under the runs leads to uneven thermoerosion of the riverbed during floods, providing the beaded form of the channel. In addition, freezing of pools during winter leads to pressure increasing under ice cover and formation of ice mounds, which crack several times during winter leading to disturbance of riverbanks. Many 1st to 3rd order streams have a specific transitional meandering-to-beaded form resembling the shape of unconfined meandering rivers, but consisting of pools and runs. However, such channels exhibit no evidences of present-day erosion of concave banks and sediment accumulation at the convex banks as typically being observed in normally meandering rivers. Such forms of channels indicates that their formation occurred by the greater channel

  2. Socio Economic Status and Traumatic Brain Injury amongst Pediatric Populations: A Spatial Analysis in Greater Vancouver

    Directory of Open Access Journals (Sweden)

    Ofer Amram

    2015-12-01

    Full Text Available Introduction: Within Canada, injuries are the leading cause of death amongst children fourteen years of age and younger, and also one of the leading causes of morbidity. Low Socio Economic Status (SES seems to be a strong indicator of a higher prevalence of injuries. This study aims to identify hotspots for pediatric Traumatic Brain Injury (TBI and examines the relationship between SES and pediatric TBI rates in greater Vancouver, British Columbia (BC, Canada. Methods: Pediatric TBI data from the BC Trauma Registry (BCTR was used to identify all pediatric TBI patients admitted to BC hospitals between the years 2000 and 2013. Spatial analysis was used to identify hotspots for pediatric TBI. Multivariate analysis was used to distinguish census variables that were correlated with rates of injury. Results: Six hundred and fifty three severe pediatric TBI injuries occurred within the BC Lower Mainland between 2000 and 2013. High rates of injury were concentrated in the East, while low rate clusters were most common in the West of the region (more affluent neighborhoods. A low level of education was the main predictor of a high rate of injury (OR = 1.13, 95% CI = 1.03–1.23, p-Value 0.009. Conclusion: While there was a clear relationship between different SES indicators and pediatric TBI rates in greater Vancouver, income-based SES indicators did not serve as good predictors within this region.

  3. Investigation on life cycle assessment of lead and zinc production

    Directory of Open Access Journals (Sweden)

    Sabere Nazari

    2015-12-01

    Full Text Available Lead and zinc production is one of the main predisposing factors of excessive greenhouse gases emissions, air pollution and water consumption. In this paper, the environmental problems of lead and zinc production in Calcimin plant are expressed and life cycle assessment of this plant is assessed. The data regarding the amount of induced global warming and pollution, acidification, and depletion of water resources were collected and discussed. It was concluded that depletion of water resources affected the environment and this was the main issue of the lead and zinc production of this plant. According to the results, in the global warming’s impact category, the proportion of carbon dioxide is more than that of methane. The results also showed that in the acidification’s impact category, the nitrogen oxide proportion is greater compared to that of the sulfur dioxide.

  4. The post-orgasmic prolactin increase following intercourse is greater than following masturbation and suggests greater satiety.

    Science.gov (United States)

    Brody, Stuart; Krüger, Tillmann H C

    2006-03-01

    Research indicates that prolactin increases following orgasm are involved in a feedback loop that serves to decrease arousal through inhibitory central dopaminergic and probably peripheral processes. The magnitude of post-orgasmic prolactin increase is thus a neurohormonal index of sexual satiety. Using data from three studies of men and women engaging in masturbation or penile-vaginal intercourse to orgasm in the laboratory, we report that for both sexes (adjusted for prolactin changes in a non-sexual control condition), the magnitude of prolactin increase following intercourse is 400% greater than that following masturbation. The results are interpreted as an indication of intercourse being more physiologically satisfying than masturbation, and discussed in light of prior research reporting greater physiological and psychological benefits associated with coitus than with any other sexual activities.

  5. Laser-assisted lead extraction: the European experience.

    Science.gov (United States)

    Kennergren, C; Bucknall, C A; Butter, C; Charles, R; Fuhrer, J; Grosfeld, M; Tavernier, R; Morgado, T B; Mortensen, P; Paul, V; Richter, P; Schwartz, T; Wellens, F

    2007-08-01

    The aim of this study is to investigate the safety and effectiveness of Excimer laser-assisted lead extraction in Europe. The final European multi-centre study experience is presented. The Excimer is a cool cutting laser (50 degrees C) with a wavelength of 308 nm. The energy is emitted from the tip of a flexible sheath and is absorbed by proteins and lipids, 64% of the energy is absorbed at a tissue depth of 0.06 mm. The sheath is positioned over the lead, and the fibrosis surrounding the lead is vaporized while advancing the sheath without damaging other leads. From August 1996 to March 2001, 383 leads (170 atrial, 213 ventricular) in 292 patients (mean age 61.6 years, range 13-96) were extracted at 14 European centres. Mean implantation time was 74 months (3-358). Most frequent indications were pocket infection (26%), non-functional leads (21%), patient morbidity (21%), septicaemia or endocarditis (14%), erosion (5%), and lead interference (8%). Median extraction time was 15 min (1-300). Complete extraction was achieved in 90.9% of the leads and partial extraction in 3.4%. Extraction failed in 5.7% of the leads. Major complications = perforations caused 10/22 (3.4/5.7%) of the failures. Most partially extracted patients were considered clinically successful, as only minor lead parts without clinical significance were left. Femoral non-laser technique was used to remove 8/12 of the non-complication failures. The total complication rate, including five minor complications (1.7%), was 5.1%. No in-hospital mortality occurred. Pacing and implantable cardioverter-defibrillator leads can safely, effectively, and predictably be extracted. Open-heart extractions can be limited to special cases. The results indicate that the traditional policy of abandoning redundant leads, instead of removing them, may be obsolete in many patients.

  6. Greater carbon stocks and faster turnover rates with increasing agricultural productivity

    Science.gov (United States)

    Sanderman, J.; Fallon, S.; Baisden, T. W.

    2013-12-01

    H.H. Janzen (2006) eloquently argued that from an agricultural perspective there is a tradeoff between storing carbon as soil organic matter (SOM) and the soil nutrient and energy benefit provided during SOM mineralization. Here we report on results from the Permanent Rotation Trial at the Waite Agricultural Institute, South Australia, indicating that shifting to an agricultural management strategy which returns more carbon to the soil, not only leads to greater carbon stocks but also increases the rate of carbon cycling through the soil. The Permanent Rotation Trial was established on a red Chromosol in 1925 with upgrades made to several treatments in 1948. Decadal soil samples were collected starting in 1963 at two depths, 0-10 and 10-22.5 cm, by compositing 20 soil cores taken along the length of each plot. We have chosen to analyze five trials representing a gradient in productivity: permanent pasture (Pa), wheat-pasture rotation (2W4Pa), continuous wheat (WW), wheat-oats-fallow rotation (WOF) and wheat-fallow (WF). For each of the soil samples (40 in total), the radiocarbon activity in the bulk soil as well as size-fractionated samples was measured by accelerator mass spectrometry at ANU's Radiocarbon Dating Laboratory (Fallon et al. 2010). After nearly 70 years under each rotation, SOC stocks increased linearly with productivity data across the trials from 24 to 58 tC ha-1. Importantly, these differences were due to greater losses over time in the low productivity trials rather than gains in SOC in any of the trials. Uptake of the bomb-spike in atmospheric 14C into the soil was greatest in the trials with the greatest productivity. The coarse size fraction always had greater Δ14C values than the bulk soil samples. Several different multi-pool steady state and non-steady state models were used to interpret the Δ14C data in terms of SOC turnover rates. Regardless of model choice, either the decay rates of all pools needed to increase or the allocation of C to

  7. Difference in peak weight transfer and timing based on golf handicap.

    Science.gov (United States)

    Queen, Robin M; Butler, Robert J; Dai, Boyi; Barnes, C Lowry

    2013-09-01

    Weight shift during the golf swing has been a topic of discussion among golf professionals; however, it is still unclear how weight shift varies in golfers of different performance levels. The main purpose of this study was to examine the following: (a) the changes in the peak ground reaction forces (GRF) and the timing of these events between high (HHCP) and low handicap (LHCP) golfers and (b) the differences between the leading and trailing legs. Twenty-eight male golfers were recruited and divided based on having an LHCP 9. Three-dimensional GRF peaks and the timing of the peaks were recorded bilaterally during a golf swing. The golf swing was divided into different phases: (a) address to the top of the backswing, (b) top of the backswing to ball contact, and (c) ball contact to the end of follow through. Repeated measures analyses of variance (α = 0.05) were completed for each study variable: the magnitude and the timing of peak vertical GRF, peak lateral GRF, and peak medial GRF (α = 0.05). The LHCP group had a greater transfer of vertical force from the trailing foot to the leading foot in phase 2 than the HHCP group. The LHCP group also demonstrated earlier timing of peak vertical force throughout the golf swing than the HHCP group. The LHCP and HHCP groups demonstrated different magnitudes of peak lateral force. The LHCP group had an earlier timing of peak lateral GRF in phase 2 and earlier timing of peak medial GRF in phases 1 and 2 than the HHCP group. In general, LHCP golfers demonstrated greater and earlier force generation than HHCP golfers. It may be relevant to consider both the magnitude of the forces and the timing of these events during golf-specific training to improve performance. These data reveal weight shifting differences that can be addressed by teaching professionals to help their students better understand weight transfer during the golf swing to optimize performance.

  8. Water quality criteria for lead

    Energy Technology Data Exchange (ETDEWEB)

    Nagpal, N.K.

    1987-01-01

    This report is one in a series that establishes water quality criteria for British Columbia. The report sets criteria for lead to protect a number of water uses, including drinking water, freshwater and marine aquatic life, wildlife, livestock, irrigation, and recreation. The criteria are set as either maximum concentrations of total lead that should not be exceeded at any time, or average concentrations that should not be exceeded over a 30-day period. Actual values are summarized.

  9. Blood Lead Levels and Cause-Specific Mortality of Inorganic Lead-Exposed Workers in South Korea.

    Directory of Open Access Journals (Sweden)

    Min-Gi Kim

    Full Text Available The objective of this study was to identify the association of blood lead level (BLL with mortality in inorganic lead-exposed workers of South Korea. A cohort was compiled comprising 81,067 inorganic lead exposed workers working between January 1, 2000, and December 31, 2004. This cohort was merged with the Korean National Statistical Office to follow-up for mortality between 2000 and 2008. After adjusting for age and other carcinogenic metal exposure, all-cause mortality (Relative risk [RR] 1.36, 95% confidence interval [CI] 1.03-1.79, digestive disease (RR 3.23, 95% CI 1.33-7.86, and intentional self-harm (RR 2.92, 95% CI 1.07-7.81 were statistically significantly higher in males with BLL >20 μg/dl than of those with BLL ≤10μg/dl. The RR of males with BLL of 10-20 μg/dl was statistically higher than of those with BLL ≤10μg/dl in infection (RR 3.73. 95% CI, 1.06-13.06. The RRs of females with 10-20 μg/dl BLL was statistically significantly greater than those with BLL <10μg/dl in all-cause mortality (RR 1.93, 95% CI 1.16-3.20 and colon and rectal cancer (RR 13.42, 95% CI 1.21-149.4. The RRs of females with BLL 10-20 μg/dl (RR 10.45, 95% CI 1.74-62.93 and BLL ≥20 μg/dl (RR 12.68, 95% CI 1.69-147.86 was statistically significantly increased in bronchus and lung cancer. The increased suicide of males with ≥20 μg/dl BLLs, which might be caused by major depression, might be associated with higher lead exposure. Also, increased bronchus and lung cancer mortality in female workers with higher BLL might be related to lead exposure considering low smoking rate in females. The kinds of BLL-associated mortality differed by gender.

  10. Archives of Atmospheric Lead Pollution

    Science.gov (United States)

    Weiss, Dominik; Shotyk, William; Kempf, Oliver

    Environmental archives such as peat bogs, sediments, corals, trees, polar ice, plant material from herbarium collections, and human tissue material have greatly helped to assess both ancient and recent atmospheric lead deposition and its sources on a regional and global scale. In Europe detectable atmospheric lead pollution began as early as 6000years ago due to enhanced soil dust and agricultural activities, as studies of peat bogs reveal. Increased lead emissions during ancient Greek and Roman times have been recorded and identified in many long-term archives such as lake sediments in Sweden, ice cores in Greenland, and peat bogs in Spain, Switzerland, the United Kingdom, and the Netherlands. For the period since the Industrial Revolution, other archives such as corals, trees, and herbarium collections provide similar chronologies of atmospheric lead pollution, with periods of enhanced lead deposition occurring at the turn of the century and since 1950. The main sources have been industry, including coal burning, ferrous and nonferrous smelting, and open waste incineration until c.1950 and leaded gasoline use since 1950. The greatest lead emissions to the atmosphere all over Europe occurred between 1950 and 1980 due to traffic exhaust. A marked drop in atmospheric lead fluxes found in most archives since the 1980s has been attributed to the phasing out of leaded gasoline. The isotope ratios of lead in the various archives show qualitatively similar temporal changes, for example, the immediate response to the introduction and phasing out of leaded gasoline. Isotope studies largely confirm source assessments based on lead emission inventories and allow the contributions of various anthropogenic sources to be calculated.

  11. Technical concept for a greater-confinement-disposal test facility

    International Nuclear Information System (INIS)

    Hunter, P.H.

    1982-01-01

    Greater confinement disposal (GCO) has been defined by the National Low-Level Waste Program as the disposal of low-level waste in such a manner as to provide greater containment of radiation, reduce potential for migration or dispersion or radionuclides, and provide greater protection from inadvertent human and biological intrusions in order to protect the public health and safety. This paper discusses: the need for GCD; definition of GCD; advantages and disadvantages of GCD; relative dose impacts of GCD versus shallow land disposal; types of waste compatible with GCD; objectives of GCD borehole demonstration test; engineering and technical issues; and factors affecting performance of the greater confinement disposal facility

  12. Relationship between width of greater trochanters and width of iliac wings in tronchanteric bursitis.

    Science.gov (United States)

    Viradia, Neal K; Berger, Alex A; Dahners, Laurence E

    2011-09-01

    Trochanteric bursitis is a common disorder that is characterized by inflammation of the bursa, superficial to the greater trochanter of the femur, leading to pain in the lateral hip, and often occurs because of acute trauma or repetitive friction involving the iliotibial band, the greater trochanter, and the bursa. In the study reported here, we hypothesized that the increased incidence of bursitis may be the result of the increased prominence of the trochanter in relation to the wings of the iliac crest. Distances between the outermost edges of trochanters and iliac wings were measured in 202 patients from the University of North Carolina Health Care System-101 without a known diagnosis and 101 with a clinical diagnosis of trochanteric bursitis. To determine significance, t tests for nonpaired data were used. Mean (SD) difference between trochanter and iliac wing widths was 28 (20) mm in the group diagnosed with trochanteric bursitis and 17 (18) mm in the control group. The difference between the groups in this regard was significant (Pbursitis group and 1.05 (.06) in the control group. The difference between these groups was significant (Pbursitis.

  13. Drinking Water Contamination Due To Lead-based Solder

    Science.gov (United States)

    Garcia, N.; Bartelt, E.; Cuff, K. E.

    2004-12-01

    The presence of lead in drinking water creates many health hazards. Exposure to lead-contaminated water can affect the brain, the central nervous system, blood cells, and kidneys, causing such problems as mental retardation, kidney disease, heart disease, stroke, and death. One way in which lead can contaminate our water supply is through the use of lead solder to join pipes. Lead solder was widely used in the past because of its ease of application as well as its low cost. Lead contamination in residential areas has previously been found to be a particularly serious problem in first-draw samples, of water that has sat stagnant in pipes overnight. To investigate the time-dependence of drinking water lead contamination, we analyzed samples taken hourly of water exposed to lead solder. While our preliminary data was insufficient to show more than a rough correlation between time of exposure and lead concentration over short periods (1-3 hours), we were able to confirm that overnight exposure of water to lead-based solder results in the presence high levels of lead. We also investigated other, external factors that previous research has indicated contribute to increased concentrations of lead. Our analysis of samples of lead-exposed water at various pH and temperatures suggests that these factors can be equally significant in terms of their contribution to elevated lead concentration levels. In particular, water that is slightly corrosive appears to severely impact the solubility of lead. As this type of water is common in much of the Northeast United States, the presence of lead-based solder in residential areas there is especially problematic. Although lead-based solder has been banned since the 1980s, it remains a serious concern, and a practical solution still requires further research.

  14. A stable lead isotopic investigation of the use of sycamore tree rings as a historical biomonitor of environmental lead contamination

    International Nuclear Information System (INIS)

    Patrick, Gavin J.; Farmer, John G.

    2006-01-01

    The validity of the use of sycamore (Acer pseudoplatanus) tree-rings for the reconstruction of atmospheric lead pollution histories was investigated. Tree cores spanning 1892-2003 were collected from several sycamores from the eastern shore of Loch Lomond, Scotland, an area with no local point sources of lead emission. The lead concentration and 206 Pb/ 207 Pb profiles of the Loch Lomond region cores were compared with corresponding data for the 21 Pb-dated loch sediment, and also with data for moss of known age from a Scottish herbarium collection. Two of the seven sycamore cores showed the same lead concentration trend as the lead flux to the loch, the rest having no similarity to either each other or the loch sediment record. Two further sycamore cores showed some similarity in their temporal 206 Pb/ 207 Pb trends to those seen in the sediment and moss records, but only in part of their profiles, whilst the 206 Pb/ 207 Pb ratios of the other sycamore cores remained relatively unchanged for the majority of the time covered, or exhibited an opposite trend. The 206 Pb/ 207 Pb ratios of the tree cores were also mostly higher than those of the previously established records for any given time period. Tree cores covering 1878-2002 were also collected along transects from Wanlockhead and Tyndrum, two areas of former lead mining and smelting associated with distinct 206 Pb/ 207 Pb ratios of 1.170 and 1.144, respectively. The Wanlockhead tree cores exhibited a generally decreasing trend in lead concentration with both time and distance from the lead mine. The characteristic 206 Pb/ 207 Pb ratio of 1.170 was observed in samples close to the mine but a decrease in the influence of the mine-derived lead was observed in more distant samples. The tree sampled at Tyndrum showed elevated lead concentrations, which decreased with time, and a fairly constant 206 Pb/ 207 Pb ratio of ∼ 1.15 reflecting input from the mine, features not observed in any other trees along the

  15. Behavior of active deposit of lead (Teisinger) in the Japanese free from occupational exposure to lead

    Energy Technology Data Exchange (ETDEWEB)

    Araki, S

    1973-12-01

    Intravenous infusion of calcium disodium ethylenediamine tetraacetate (CaEDTA) was given to 45 Japanese adults without occupational exposure to lead for 1 hr at a dosage of 20 mg/kg body weight in 250 ml of 5 percent glucose solution. The urinary excretion of lead was estimated for 24 hr before, and for 2 hr and 24 hr after the administration. The least variation of the lead content was recognized in the 24-hour urinary excretion after the injection of CaEDTA. No sexual difference was noted in the creatinine-corrected lead concentration. By multiple linear regression and correlation analyses, age was found to be significant in determining positively the lead level mobilized in 24-hour urine samples. Height was significant in determining positively the spontaneous 24-hour urinary lead excretion. Certain significant correlations existed among lead in blood, delta-aminolevulinic acid dehydratase in erythrocytes, delta-aminolevulinic acid in urine, coproporphyrin in urine, lead in urine, and lead mobilized by CaEDTA. The existence of active body burden of lead was suggested in human subjects under usual urban conditions where the total ambient lead concentration averaged 1.7 micrograms/cm m of air. Based on a few assumptions, it was calculated that about 3 micrograms of lead was retained on the average per day by a Japanese adult. Daily retention of lead by Japanese adults was formularized as lead in micrograms equals a constant (K) times daily creatinine excretion in grams, where K is 1.77 in men and 2.73 in women. (Air Pollut. Abstr.)

  16. Integrating amplifiers for PHENIX lead-glass and lead-scintillator calorimeters

    International Nuclear Information System (INIS)

    Wintenberg, A.L.; Simpson, M.L.; Britton, C.L. Jr.; Palmer, R.L.; Jackson, R.G.

    1995-01-01

    Two types of integrating amplifier systems have been developed for use with lead-glass and lead-scintillator calorimeters with photomultiplier tube readout. Requirements for the amplifier system include termination of the line from the photomultiplier, compact size and low power dissipation to allow multiple channels per chip, dual range outputs producing 10-bit accuracy over a 14-bit dynamic range, rms noise levels of one LSB or less, and compatibility with timing filter amplifiers, tower sum circuits for triggering and calibration circuits to be built on the same integrated circuit (IC). Advantages and disadvantages of an active integrator system are compared and contrasted to those of a passive integrator-based system. In addition, details of the designs and results from prototype devices including an 8-channel active integrator IC fabricated in 1.2 microm Orbit CMOS are presented

  17. Lead in some food crops and trees

    Energy Technology Data Exchange (ETDEWEB)

    Warren, H V; Delavault, R E

    1962-02-01

    An investigation has been made of the lead content of trees and some of the more common vegetables and cereals (maize, cabbage, potatoes, carrots, beets, onions, peas, hops, oats, rhubarb, lettuce, cauliflower, leeks, barley, rye, and wheat) grown in British Columbia and in Great Britain. The lead content of the lime, yew, willow, birch, oak, ash, hazel and cypress was determined. It was concluded that in areas where soils have an abnormally high lead content, food products may acquire up to ten times as much lead, or more, than those grown on normal soil.

  18. Song Leading Effectiveness of Undergraduate Education Majors: A Comparison of Student Self Ratings and Expert Ratings under Three Conditions.

    Science.gov (United States)

    Barry, Nancy H.; Orlofsky, Diane DeNicola

    1997-01-01

    Examines the song leading effectiveness of undergraduate education majors under three conditions: unaccompanied, accompanied with autoharp, and accompanied by recording. Finds that students rate themselves higher than experts do; there is greater eye contact using rote or recording; and there is greater tempo accuracy using rote and autoharp. (DSK)

  19. Multigrid Reduction in Time for Nonlinear Parabolic Problems

    Energy Technology Data Exchange (ETDEWEB)

    Falgout, R. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Manteuffel, T. A. [Univ. of Colorado, Boulder, CO (United States); O' Neill, B. [Univ. of Colorado, Boulder, CO (United States); Schroder, J. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-01-04

    The need for parallel-in-time is being driven by changes in computer architectures, where future speed-ups will be available through greater concurrency, but not faster clock speeds, which are stagnant.This leads to a bottleneck for sequential time marching schemes, because they lack parallelism in the time dimension. Multigrid Reduction in Time (MGRIT) is an iterative procedure that allows for temporal parallelism by utilizing multigrid reduction techniques and a multilevel hierarchy of coarse time grids. MGRIT has been shown to be effective for linear problems, with speedups of up to 50 times. The goal of this work is the efficient solution of nonlinear problems with MGRIT, where efficient is defined as achieving similar performance when compared to a corresponding linear problem. As our benchmark, we use the p-Laplacian, where p = 4 corresponds to a well-known nonlinear diffusion equation and p = 2 corresponds to our benchmark linear diffusion problem. When considering linear problems and implicit methods, the use of optimal spatial solvers such as spatial multigrid imply that the cost of one time step evaluation is fixed across temporal levels, which have a large variation in time step sizes. This is not the case for nonlinear problems, where the work required increases dramatically on coarser time grids, where relatively large time steps lead to worse conditioned nonlinear solves and increased nonlinear iteration counts per time step evaluation. This is the key difficulty explored by this paper. We show that by using a variety of strategies, most importantly, spatial coarsening and an alternate initial guess to the nonlinear time-step solver, we can reduce the work per time step evaluation over all temporal levels to a range similar with the corresponding linear problem. This allows for parallel scaling behavior comparable to the corresponding linear problem.

  20. Greater bottoms upgrading with Albemarle's e-bed catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Toshima, H.; Sedlacek, Z.; Backhouse, D.; Mayo, S.; Plantenga, F. [Albemarle Catalysts, Houston, TX (United States)

    2006-07-01

    The E-bed process is a heavy oil upgrading technology that produces near isothermal reactor conditions at a constant catalytic activity. However, E-bed conversion optimization is limited by reactor and downstream fouling problems caused by asphaltene precipitation. While asphaltene precipitation can controlled by reducing hydrogenation, high hydrogenation activity is needed for the removal of sulfur and heavy metals. This presentation described an asphaltene molecule management concept to reduce the fouling of E-bed units. Sediment reduction and high hydrogenation catalysts were used in a modified E-bed process with a variety of feeds and operating conditions. It was observed that the KF1312 catalyst achieved much higher sediment-reduction capability along with satisfactory hydrogenation activity with the different kinds of crude oil sources tested. The catalyst hydrocracked the asphaltenes into smaller molecules, which created greater asphaltene solubility. The sediment reduction capacity of the catalyst-staging technology is now being optimized. It was concluded that the technology will help to reduce fouling in E-bed processes and lead to improved conversion rates for refineries. refs., tabs., figs.

  1. Scaling violations beyond the leading order

    CERN Document Server

    Petronzio, R

    1981-01-01

    The authors are concerned with the explicit construction of a method which generalizes beyond leading order the simple probabilistic interpretation of leading scaling violations. The results obtained in this language allow to predict the evolution with the variation of external invariants not only of 'space-like' processes, where the off- shell partons starting the hard interaction have space-like four momenta, like in the case of deep inelastic scattering or Drell-Yan, but also of 'time-like' processes, like the one-particle inclusive e /sup +/e/sup -/ annihilation, where the partons acting in the fragmentation functions have 'time-like' off-shell invariant masses. (9 refs).

  2. Adaptive Tele-Therapies Based on Serious Games for Health for People with Time-Management and Organisational Problems: Preliminary Results

    OpenAIRE

    Frutos-Pascual, Maite; García Zapirain, Begoña; Méndez Zorrilla, Amaia

    2014-01-01

    Attention Deficit with Hyperactivity Disorder (ADHD) is one of the most prevalent disorders within the child population today. Inattention problems can lead to greater difficulties in completing assignments, as well as problems with time management and prioritisation of tasks. This article presents an intelligent tele-therapy tool based on Serious Games for Health, aimed at the improvement of time management skills and the prioritisation of tasks. This tele-system is based on the use of decis...

  3. Excretion of lead and its biological activity several years after termination of exposure

    Science.gov (United States)

    Přerovská, I.; Teisinger, J.

    1970-01-01

    Přerovská, and Teisinger, J. (1970).Brit. J. industr. Med.,27, 352-355. Excretion of lead and its biological activity several years after termination of exposure. A group of 27 persons who had been treated some years previously for chronic lead poisoning at our clinic, and who had not come into occupational contact with lead since, was examined. Half of them had had no occupational exposure to lead for 3 to 5 years and the others for 8 to 17 years. In most of these persons there is still an increased lead excretion, originating from an increased deposit in the bones. The mobilization test after calcium versenate (CaEDTA) injection was greater than 0·350 mg/24 hours. The values found for haemoglobin, punctate basophilia, coproporphyrin and ALA in urine were normal, but there was, in all cases, a decreased ALA-D activity. This finding suggests biological activity of such negligible lead flow many years after termination of exposure. PMID:5488694

  4. {beta}-adrenergic receptor density and adenylate cyclase activity in lead-exposed rat brain after cessation of lead exposure

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Huoy-Rou [I-Shou University, Department of Biomedical Engineering, Dashu Shiang, Kaohsiung County (Taiwan); Tsao, Der-An [Fooyin University of Technology, Department of Medical Technology (Taiwan); Yu, Hsin-Su [Taiwan University, Department of Dermatology, College of Medicine (Taiwan); Ho, Chi-Kung [Kaohsiung Medical University, Occupational Medicine (Taiwan); Kaohsiung Medical University, Graduate Institute of Medicine, Research Center for Occupational Disease (Taiwan)

    2005-01-01

    To understanding the reversible or irreversible harm to the {beta}-adrenergic system in the brain of lead-exposed rats, this study sets up an animal model to estimate the change in the sympathetic nervous system of brain after lead exposure was withdrawn. We address the following topics in this study: (a) the relationship between withdrawal time of lead exposure and brain {beta}-adrenergic receptor, blood lead level, and brain lead level in lead-exposed rats after lead exposure was stopped; and (b) the relationship between lead level and {beta}-adrenergic receptor and cyclic AMP (c-AMP) in brain. Wistar rats were chronically fed with 2% lead acetate and water for 2 months. Radioligand binding was assayed by a method that fulfilled strict criteria of {beta}-adrenergic receptor using the ligand [{sup 125}I]iodocyanopindolol. The levels of lead were determined by electrothermal atomic absorption spectrometry. The c-AMP level was determined by radioimmunoassay. The results showed a close relationship between decreasing lead levels and increasing numbers of brain {beta}-adrenergic receptors and brain adenylate cyclase activity after lead exposure was withdrawn. The effect of lead exposure on the {beta}-adrenergic system of the brain is a partly reversible condition. (orig.)

  5. Efficacy of aprons equivalent to 0.5 mm of lead in PET procedures using the Monte Carlo method

    International Nuclear Information System (INIS)

    Fonseca, R.B.; Amaral, A.; Campos, L.

    2012-01-01

    In positron emission tomography (PET), health staff is exposed to 511-keV photons, which is a result of the positron annihilation process. This energy is about four times greater than the 140 keV commonly found in studies based on single photon emission computed tomography (SPECT). Besides this different level of energy, 0.5 mm lead-equivalent aprons have being used either in SPECT or PET procedures. In this context, this work was designed for evaluating the effectiveness of such aprons in individual radioprotection of health professionals involved in positron emission tomography. For this, by using MCNP4C-based Monte Carlo simulations, the average energy delivered per particle to the regions corresponding to operational quantities Hp(10) and Hp(0.07) were calculated for two conditions of individual exposures: wearing and not wearing a 0.05 mm lead-equivalent apron. The results obtained pointed out that Hp(10) has similar value in both situations. On the other hand, for the region corresponding to Hp(0.07), wearing this lead apron will improve this dose in about 26%. On the basis of this work, 0.5 mm lead equivalent aprons do not offer adequate protection for medical staff working on positron emission tomography. (author)

  6. Land processes lead to surprising patterns in atmospheric residence time

    Science.gov (United States)

    van der Ent, R.; Tuinenburg, O.

    2017-12-01

    Our research using atmospheric moisture tracking methods shows that the global average atmospheric residence time of evaporation is 8-10 days. This residence time appears to be Gamma distributed with a higher probability of shorter than average residence times and a long tail. As a consequence the median of this residence time is around 5 days. In some places in the world the first few hours/days after evaporation there seems to be a little chance for a moisture particle to precipitate again, which is reflected by a Gamma distribution having a shape parameter below 1. In this study we present global maps of this parameter using different datasets (GLDAS and ERA-Interim). The shape parameter is as such also a measure for the land-atmospheric coupling strength along the path of the atmospheric water particle. We also find that different evaporation components: canopy interception, soil evaporation and transpiration appear to have different residence time distributions. We find a daily cycle in the residence time distribution over land, which is not present over the oceans. In this paper we will show which of the evaporation components is mainly responsible for this daily pattern and thus exhibits the largest daily cycle of land-atmosphere coupling strength.

  7. The addition of red lead to flat plate and tubular valve regulated miners cap lamp lead-acid batteries

    Energy Technology Data Exchange (ETDEWEB)

    Ferg, E.E.; Loyson, P. [Department of Chemistry, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031 (South Africa); Poorun, A. [Willard Batteries, P.O. Box 1844, Port Elizabeth 6000 (South Africa)

    2006-04-21

    The study looked at the use of red lead in the manufacturing of valve regulated lead acid (VRLA) miners cap lamp (MCL) batteries that were made with either flat plate or tubular positive electrodes. A problem with using only grey oxide in the manufacture of thick flat plate or tubular electrodes is the poor conversion of the active material to the desired lead dioxide. The addition of red lead to the initial starting material improves the formation efficiency but is considerably more expensive thereby increasing the cost of manufacturing. The study showed that by carefully controlling the formation conditions in terms of the voltage and temperature of a battery, good capacity performance can be achieved for cells made with flat plate electrodes that contain up to 25% red lead. The small amount of red lead in the active cured material reduces the effect of electrode surface sulphate formation and allows the battery to achieve its rated capacity within the first few cycles. Batteries made with flat plate positive electrodes that contained more that 50% red lead showed good initial capacity but had poor structural active material bonding. The study showed that MCL batteries made with tubular positive electrodes that contained less than 75% red lead resulted in a poorly formed electrode with limited capacity utilization. Pickling and soaking times of the tubular electrodes should be kept at a minimum thereby allowing higher active material utilization during subsequent capacity cycling. The study further showed that it is beneficial to use higher formation rates in order to reduce manufacturing time and to improve the active material characteristics. (author)

  8. Gammatography of thick lead vessels

    International Nuclear Information System (INIS)

    Raghunath, V.M.; Bhatnagar, P.K.; Sundaram, V.M.

    1979-01-01

    Radiography, scintillation and GM counting and dose measurements using ionisation chamber equipment are commonly used for detecting flaws/voids in materials. The first method is mostly used for steel vessels and to a lesser extent thin lead vessels also and is essentially qualitative. Dose measuring techniques are used for very thick and large lead vessels for which high strength radioactive sources are required, with its inherent handling problems. For vessels of intermediate thicknesses, it is ideal to use a small strength source and a GM or scintillation counter assembly. At the Reactor Research Centre, Kalpakkam, such a system was used for checking three lead vessels of thicknesses varying from 38mm to 65mm. The tolerances specified were +- 4% variation in lead thickness. The measurements also revealed the non concentricity of one vessel which had a thickness varying from 38mm to 44mm. The second vessel was patently non-concentric and the dimensional variation was truly reproduced in the measurements. A third vessel was fabricated with careful control of dimensions and the measurements exhibited good concentricity. Small deviations were observed, attributable to imperfect bondings between steel and lead. This technique has the following advantages: (a) weaker sources used result in less handling problems reducing the personnel exposures considerably; (b) the sensitivity of the instrument is quite good because of better statistics; (c) the time required for scanning a small vessel is more, but a judicious use of a scintillometer for initial fast scan will help in reducing the total scanning time; (d) this method can take advantage of the dimensional variations themselves to get the calibration and to estimate the deviations from specified tolerances. (auth.)

  9. Buying time promotes happiness.

    Science.gov (United States)

    Whillans, Ashley V; Dunn, Elizabeth W; Smeets, Paul; Bekkers, Rene; Norton, Michael I

    2017-08-08

    Around the world, increases in wealth have produced an unintended consequence: a rising sense of time scarcity. We provide evidence that using money to buy time can provide a buffer against this time famine, thereby promoting happiness. Using large, diverse samples from the United States, Canada, Denmark, and The Netherlands ( n = 6,271), we show that individuals who spend money on time-saving services report greater life satisfaction. A field experiment provides causal evidence that working adults report greater happiness after spending money on a time-saving purchase than on a material purchase. Together, these results suggest that using money to buy time can protect people from the detrimental effects of time pressure on life satisfaction.

  10. [Effect of the chelator Zn-DTPA on the excretion of lead in lead intoxication mice detected with ICP-MS].

    Science.gov (United States)

    Li, Chen; Lu, Kai-zhi; Zhou, Qi; Wang, Qiong; Zeng, Yu-liang; Yin, Hong-jun; He, Xuan-hui; Tian, Ying; Dong, Jun-Xing

    2014-11-01

    To study the lead excretion effect of the chelator Zn-DTPA on the lead intoxication mice, inductively coupled plasma mass spectrometry (ICP-MS) was applied to detect the lead content of biological samples. The acute lead intoxication mice model was established by injecting lead acetate intraperitoneally with the dose of 1 mg. Zn-DTPA was administered intraperitoneally to mice once daily for five consecutive days 4 h after intoxication. Control group, model group, combination of Zn-DTPA and Ca-DTPA group were evaluated at the same time. The urine was collected every day. The mice were sacrificed in batches in the 2rd, 4th, 6th day. Biological samples including urine, whole blood, femur and brain were prepared and nitrated. Lead concentration was detected by ICP-MS. The result showed that Zn-DTPA could increase lead content in urine markedly and reduce lead content in blood, femur and brain.

  11. Greater Transparency Needed

    OpenAIRE

    Angelo Melino; Michael Parkin

    2010-01-01

    Financial market participants would benefit from a better understanding of how the Bank of Canada sets the overnight interest rate in response to economic developments. More accurate forecasts of the Bank’s future policy choices would lead to better financial decisions and better price and wage-setting decisions, making it easier for the Bank to hit its 2 percent inflation target. Currently, the Bank’s internal model predicts a path for the overnight rate that is inconsistent with the expecta...

  12. Total contribution of airborne lead to blood lead.

    OpenAIRE

    Manton, W I

    1985-01-01

    A nine year study of blood lead concentrations and isotope ratios carried out on a married couple shows that pulmonary deposition cannot account for all the airborne lead in blood; that lead from bone may comprise 70% of blood lead; and that during pregnancy blood lead may double due to mobilisation of lead from bone.

  13. Total contribution of airborne lead to blood lead.

    Science.gov (United States)

    Manton, W I

    1985-01-01

    A nine year study of blood lead concentrations and isotope ratios carried out on a married couple shows that pulmonary deposition cannot account for all the airborne lead in blood; that lead from bone may comprise 70% of blood lead; and that during pregnancy blood lead may double due to mobilisation of lead from bone. PMID:3970881

  14. Cognitively Engaging Activity is Associated with Greater Cortical and Subcortical Volumes

    Directory of Open Access Journals (Sweden)

    Talia R. Seider

    2016-05-01

    Full Text Available As the population ages and dementia becomes a growing healthcare concern, it is increasingly important to identify targets for intervention to delay or attenuate cognitive decline. Research has shown that the most successful interventions aim at altering lifestyle factors. Thus, this study examined how involvement in physical, cognitive, and social activity is related to brain structure in older adults. Sixty-five adults (mean age = 71.4 years, standard deviation = 8.9 received the Community Healthy Activities Model Program for Seniors (CHAMPS, a questionnaire that polls everyday activities in which older adults may be involved, and also underwent structural magnetic resonance imaging. Stepwise regression with backwards selection was used to predict weekly time spent in either social, cognitive, light physical, or heavy physical activity from the volume of one of the cortical or subcortical regions of interest (corrected by intracranial volume as well as age, education, and gender as control variables. Regressions revealed that more time spent in cognitive activity was associated with greater volumes of all brain regions studied: total cortex (β = .289, p = .014, frontal (β = .276, p = .019, parietal (β = .305, p = .009, temporal (β = .275, p = .020, and occipital (β = .256, p = .030 lobes, and thalamus (β = .310, p = .010, caudate (β = .233, p = .049, hippocampus (β = .286, p = .017, and amygdala (β = .336, p = .004. These effects remained even after accounting for the positive association between cognitive activity and education. No other activity variable was associated with brain volumes. Results indicate that time spent in cognitively engaging activity is associated with greater cortical and subcortical brain volume. Findings suggest that interventions aimed at increasing levels of cognitive activity may delay cognitive consequences of aging and decrease the risk of developing dementia.

  15. Lead- or Lead-bismuth-cooled fast reactors

    International Nuclear Information System (INIS)

    Bouchter, J.C.; Courouau, J.L.; Dufour, P.; Guidez, J.; Latge, C.; Martinelli, L.; Renault, C.; Rimpault, G.

    2014-01-01

    Lead-cooled fast reactors are one of the 6 concepts retained for the 4. generation of nuclear reactors. So far no lead-cooled reactors have existed in the world except lead-bismuth-cooled reactors in soviet submarines. Some problems linked to the use of the lead-bismuth eutectic appeared but were satisfactorily solved by a more rigorous monitoring of the chemistry of the lead-bismuth coolant. Lead presents various advantages as a coolant: no reactivity with water and the air,a high boiling temperature and low contamination when irradiated. The main asset of the lead-bismuth alloy is the drop of the fusion temperature from 327 C degrees to 125 C degrees. The main drawback of using lead (or lead-bismuth) is its high corrosiveness with metals like iron, chromium and nickel. The high corrosiveness of the coolant implies low flow velocities which means a bigger core and consequently a bigger reactor containment. Different research programs in the world (in Europe, Russia and the USA) are reviewed in the article but it appears that the development of this type of reactor requires technological breakthroughs concerning materials and the resistance to corrosion. Furthermore the concept of lead-cooled reactors seems to be associated to a range of low output power because of the compromise between the size of the reactor and its resistance to earthquakes. (A.C.)

  16. Lead in teeth from lead-dosed goats: Microdistribution and relationship to the cumulative lead dose

    International Nuclear Information System (INIS)

    Bellis, David J.; Hetter, Katherine M.; Jones, Joseph; Amarasiriwardena, Dula; Parsons, Patrick J.

    2008-01-01

    Teeth are commonly used as a biomarker of long-term lead exposure. There appear to be few data, however, on the content or distribution of lead in teeth where data on specific lead intake (dose) are also available. This study describes the analysis of a convenience sample of teeth from animals that were dosed with lead for other purposes, i.e., a proficiency testing program for blood lead. Lead concentration of whole teeth obtained from 23 animals, as determined by atomic absorption spectrometry, varied from 0.6 to 80 μg g -1 . Linear regression of whole tooth lead (μg g -1 ) on the cumulative lead dose received by the animal (g) yielded a slope of 1.2, with r 2 =0.647 (p -1 , were found in circumpulpal dentine. Linear regression of circumpulpal lead (μg g -1 ) on cumulative lead dose (g) yielded a slope of 23 with r 2 =0.961 (p=0.0001). The data indicated that whole tooth lead, and especially circumpulpal lead, of dosed goats increased linearly with cumulative lead exposure. These data suggest that circumpulpal dentine is a better biomarker of cumulative lead exposure than is whole tooth lead, at least for lead-dosed goats

  17. A stable lead isotopic investigation of the use of sycamore tree rings as a historical biomonitor of environmental lead contamination

    Energy Technology Data Exchange (ETDEWEB)

    Patrick, Gavin J. [School of GeoSciences, University of Edinburgh, West Mains Road, Edinburgh, EH9 3JJ, Scotland (United Kingdom); Farmer, John G. [School of GeoSciences, University of Edinburgh, West Mains Road, Edinburgh, EH9 3JJ, Scotland (United Kingdom)]. E-mail: J.G.Farmer@ed.ac.uk

    2006-06-01

    The validity of the use of sycamore (Acer pseudoplatanus) tree-rings for the reconstruction of atmospheric lead pollution histories was investigated. Tree cores spanning 1892-2003 were collected from several sycamores from the eastern shore of Loch Lomond, Scotland, an area with no local point sources of lead emission. The lead concentration and {sup 206}Pb/{sup 207}Pb profiles of the Loch Lomond region cores were compared with corresponding data for the {sup 21}Pb-dated loch sediment, and also with data for moss of known age from a Scottish herbarium collection. Two of the seven sycamore cores showed the same lead concentration trend as the lead flux to the loch, the rest having no similarity to either each other or the loch sediment record. Two further sycamore cores showed some similarity in their temporal {sup 206}Pb/{sup 207}Pb trends to those seen in the sediment and moss records, but only in part of their profiles, whilst the {sup 206}Pb/{sup 207}Pb ratios of the other sycamore cores remained relatively unchanged for the majority of the time covered, or exhibited an opposite trend. The {sup 206}Pb/{sup 207}Pb ratios of the tree cores were also mostly higher than those of the previously established records for any given time period. Tree cores covering 1878-2002 were also collected along transects from Wanlockhead and Tyndrum, two areas of former lead mining and smelting associated with distinct {sup 206}Pb/{sup 207}Pb ratios of 1.170 and 1.144, respectively. The Wanlockhead tree cores exhibited a generally decreasing trend in lead concentration with both time and distance from the lead mine. The characteristic {sup 206}Pb/{sup 207}Pb ratio of 1.170 was observed in samples close to the mine but a decrease in the influence of the mine-derived lead was observed in more distant samples. The tree sampled at Tyndrum showed elevated lead concentrations, which decreased with time, and a fairly constant {sup 206}Pb/{sup 207}Pb ratio of {approx} 1.15 reflecting input

  18. Isolation of radioactive thallium from lead targets

    International Nuclear Information System (INIS)

    Kozlova, M.D.; Sevast'yanova, A.S.; Malinin, A.B.; Kurenkov, N.V.

    1989-01-01

    Two methods of thallium-201 preperation from Pb-targets irradiated with protons: precipitation-extraction (1) and extraction (2) - are developed. When the target irraiated is extracted during the time necessary for bismuth-201 transformation into lead-201, lead macroquantity containing lead-201 was separated from undesirable thallium radionuclides, which are formed in direct nuclear reactions. The lead fraction was extracted to accumulate thallium-201, and it was separated from lead mocroquantity. The target was dissolved in the nitric acid. The 1st method differs from the 2nd one by the fact that before thallium-201 extraction, lead was precipitaed by the nitric acid. The 1st method permits to separate thallium-201 with chemical yield not less than 90 %, the 2nd one - ≥95 %. 2 refs

  19. Consequences of Secondary Calibrations on Divergence Time Estimates.

    Directory of Open Access Journals (Sweden)

    John J Schenk

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

  20. Neural correlates of time versus money in product evaluation

    Directory of Open Access Journals (Sweden)

    Sebastian eLehmann

    2012-10-01

    Full Text Available The common saying time is money reflects the widespread belief in many people’s everyday life that time is valuable like money. Psychologically and neurophysiologically, however, these concepts seem to be quite different. This research replicates prior behavioral investigations by showing that merely mentioning time (compared to merely mentioning money leads participants to evaluate a product more positively. Beyond this finding, the present functional magnetic resonance imaging (fMRI experiment provides novel insight into the neurophysiological underpinnings of this behavioral effect by showing that more positive product evaluations in the time primes (compared to money primes are preceded by increased activation in the insula. Our data, therefore, support the idea of a time mindset that is different from a money mindset. Studies on the functional neuroanatomy of the insula have implicated this brain area in distinct but related psychological phenomena such as urging, addiction, loss aversion, and love. These functions imply greater personal connection between the consumer and a target subject or object and, thus, help explain why time-primed consumers rate products more positively.

  1. BOOK REVIEW: Great Physicists - The Life and Times of Leading Physicists from Galileo to Hawking

    Science.gov (United States)

    Cropper, William H.

    2002-11-01

    The author, a former American chemistry professor, has organized his book into nine parts with 29 chapters, covering, in a fairly historical sequence and systemtic conceptual progression, all fundamentals of today's physics: i.e., mechanics, thermodynamics, electromagnetism, statistical mechanics, relativity, quantum mechanics, nuclear physics, particle physics, astronomy-astrophysics-cosmology. Obviously, the 20th century (when about 90% of professional physicists of all time worked) assumes with five topics the dominant role in this enterprise. For each topic, a small number (ranging from one to eight) of leading personalities is selected and the biographies of these 29 physicists, including two women (Marie Curie and Lise Meitner), are presented in some detail together with their achievements in the particular topic. Important relevant contributions of other scholars to each topic are also discussed. In addition, Cropper provides each of the topics with a short 'historical synopsis' justifying his selection of key persons. One may argue that concentrating on leading physicists constitutes an old-fashioned approach to displaying the history and contents of fundamental topics in physics. However, the mixture of biographies and explanation of leading contributions given here will certainly serve for a larger public, not just professional physicists and scientists, as a guide through the exciting development of physical ideas and discoveries. In general, the presentation of the material is quite satisfactory (with only few slips, e.g., in the Meitner story, where the author follows too closely a new biography) and gives the essence of the great advances in physics since the 15th century. One notices perhaps the limitation of the author in cases where no biography in English is available - this would also explain the omission of some of the main contributors to atomic and particle physics, such as Arnold Sommerfeld and Hideki Yukawa, or that French or Russian readers

  2. Recovery of slowed nerve conduction velocity in lead-exposed workers

    Energy Technology Data Exchange (ETDEWEB)

    Araki, S.; Honma, T.; Yanagihara, S.; Ushio, K.

    1980-06-01

    Maximum motor nerve conduction velocities in the median nerve (MCV) and blood lead (PbB) were repeatedly measured in 14 lead-exposed workers with an initial PbB from 0.7 to 4.0 ..mu..mol/kg (median 2.3 ..mu..mol/kg) for a period from 3 months to 7 years: A certain dose of Calcium Disodium Ethylenediaminetetraacetic Acid (CaEDTA) was injected intravenously into most of the subjects during the period. In seven subjects, MCV improved by more than 4 m/s during the observation period which involved the first two successive measurements of MCV and PbB, but the remaining seven subjects showed the minimal alteration (within +- 4.0 m/s). The initial value of MCV was significantly slower (P < 0.01) and the decrease in PbB was significantly greater (P < 0.05) in the group of subjects having shown the improvement of MCV by more than 4 m/s. The initial value of MCV was significant in determining the alteration in MCV in multiple regression analysis and, together with the change in PbB, explained 31% of the alteration in MCV between the first two successive measurements. The initial level of PbB, dose of CaEDTA, time interval between the measurements and age played no essential part in the alteration in MCV. The alteration in MCV throughout the whole observational period in each subject significantly correlated with the concurrent change in PbB (r = -0.573, P < 0.001).

  3. Diagnostic value of ST-segment deviations during cardiac exercise stress testing: Systematic comparison of different ECG leads and time-points.

    Science.gov (United States)

    Puelacher, Christian; Wagener, Max; Abächerli, Roger; Honegger, Ursina; Lhasam, Nundsin; Schaerli, Nicolas; Prêtre, Gil; Strebel, Ivo; Twerenbold, Raphael; Boeddinghaus, Jasper; Nestelberger, Thomas; Rubini Giménez, Maria; Hillinger, Petra; Wildi, Karin; Sabti, Zaid; Badertscher, Patrick; Cupa, Janosch; Kozhuharov, Nikola; du Fay de Lavallaz, Jeanne; Freese, Michael; Roux, Isabelle; Lohrmann, Jens; Leber, Remo; Osswald, Stefan; Wild, Damian; Zellweger, Michael J; Mueller, Christian; Reichlin, Tobias

    2017-07-01

    Exercise ECG stress testing is the most widely available method for evaluation of patients with suspected myocardial ischemia. Its major limitation is the relatively poor accuracy of ST-segment changes regarding ischemia detection. Little is known about the optimal method to assess ST-deviations. A total of 1558 consecutive patients undergoing bicycle exercise stress myocardial perfusion imaging (MPI) were enrolled. Presence of inducible myocardial ischemia was adjudicated using MPI results. The diagnostic value of ST-deviations for detection of exercise-induced myocardial ischemia was systematically analyzed 1) for each individual lead, 2) at three different intervals after the J-point (J+40ms, J+60ms, J+80ms), and 3) at different time points during the test (baseline, maximal workload, 2min into recovery). Exercise-induced ischemia was detected in 481 (31%) patients. The diagnostic accuracy of ST-deviations was highest at +80ms after the J-point, and at 2min into recovery. At this point, ST-amplitude showed an AUC of 0.63 (95% CI 0.59-0.66) for the best-performing lead I. The combination of ST-amplitude and ST-slope in lead I did not increase the AUC. Lead I reached a sensitivity of 37% and a specificity of 83%, with similar sensitivity to manual ECG analysis (34%, p=0.31) but lower specificity (90%, pST-deviations is highest when evaluated at +80ms after the J-point, and at 2min into recovery. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Evaluation of home lead remediation in an Australian mining community.

    Science.gov (United States)

    Boreland, F; Lesjak, M; Lyle, D

    2009-12-20

    In 1994 a comprehensive program was established to reduce children's blood lead levels in Broken Hill, NSW, Australia. Home remediation (abatement of lead hazards in a child's home) was included as part of a case management strategy for children with blood lead levels >or=15 microg/dL. Children with blood lead levels >or=30 microg/dL were offered immediate home remediation. Children with blood lead levels of 15-29 microg/dL were allocated to 'immediate' or 'delayed' home remediation; a subset of these participated in a randomized controlled trial (RCT) to evaluate the effectiveness of home remediation for reducing blood lead levels. One hundred and seventeen children received home remediation. One hundred and thirteen returned for follow-up blood tests, 88 of whom participated in the RCT. On average children's blood lead levels decreased by 1.7 microg/dL (10%) in the 6 months after remediation and by 2.2 microg/dL (13%) in the 6-12 months after remediation. However, remediation did not significantly change the rate of decline in blood lead levels (P=0.609). There was no evidence of association between change in children's blood lead levels and changes in lead loading in their homes. The results are consistent with the published literature, which suggests that home remediation does not reduce children's exposure to lead sufficiently to cause a moderate or greater decrease in their blood lead level. In communities where lead is widely dispersed, the study suggests that it is important to assess potential sources and pathways by which children are exposed to lead when developing an intervention plan, and the need for multiple interventions to effectively reduce blood lead levels. The findings reinforce the ongoing need for rigorous epidemiological evaluation of lead management programs to improve the evidence base, and for effective primary prevention to avoid children being exposed to lead in the first place.

  5. Responsive and resilient supply chain network design under operational and disruption risks with delivery lead-time sensitive customers

    DEFF Research Database (Denmark)

    Fattahi, Mohammad; Govindan, Kannan; Keyvanshokooh, Esmaeil

    2017-01-01

    We address a multi-period supply chain (SC) network design where demands of customers depend on facilities serving them based on their delivery lead-times. Potential customer demands are stochastic, and facilities’ capacity varies randomly because of possible disruptions. Accordingly, we develop...... a multi-stage stochastic program, and model disruptions’ effect on facilities’ capacity. The SC responsiveness risk is limited and, to obtain a resilient network, both mitigation and contingency strategies are exploited. Computational results on a real-life case study and randomly generated problem...... instances demonstrate the model's applicability, risk-measurement policies’ performance, and the influence of mitigation and contingency strategies on SC's resiliency....

  6. The effects of husband's alcohol consumption on married women in three low-income areas of Greater Mumbai.

    Science.gov (United States)

    Berg, Marlene J; Kremelberg, David; Dwivedi, Purva; Verma, Supriya; Schensul, Jean J; Gupta, Kamla; Chandran, Devyani; Singh, S K

    2010-08-01

    Gender-based violence rooted in norms, socialization practices, structural factors, and policies that underlie men's abusive practices against married women in India is exacerbated by alcohol. The intersection of domestic violence, childhood exposure to alcohol and frustration, which contribute to drinking and its consequences including forced sex is explored through analysis of data obtained from 486 married men living with their wives in a low-income area of Greater Mumbai. SEM shows pathways linking work-related stress, greater exposure to alcohol as a child, being a heavy drinker, and having more sexual partners (a proxy for HIV risk). In-depth ethnographic interviews with 44 married women in the study communities reveal the consequences of alcohol on women's lives showing how married women associate alcohol use and violence with different patterns of drinking. The study suggests ways alcohol use leads from physical and verbal abuse to emotional and sexual violence in marriage. Implications for gendered multi-level interventions addressing violence and HIV risk are explored.

  7. Lead sources in human diet in Greenland

    DEFF Research Database (Denmark)

    Bjerregaard, Peter; Johansen, Poul; Mulvad, Gert

    2004-01-01

    Although blood lead levels have declined in Greenland, they are still elevated despite the fact that lead levels in the Greenland environment are very low. Fragments of lead shot in game birds have been suggested as an important source of dietary exposure, and meals of sea birds, particularly eider......, contain high concentrations of lead. In a cross-sectional population survey in Greenland in 1993-1994, blood lead adjusted for age and sex was found to be associated with the reported consumption of sea birds. Participants reporting less than weekly intake of sea birds had blood lead concentrations...... of approximately 75 microg/L, whereas those who reported eating sea birds several times a week had concentrations of approximately 110 microg/L, and those who reported daily intake had concentrations of 170 microg/L (p = 0.01). Blood lead was not associated with dietary exposure to other local or imported food...

  8. Proposal of lead time reduction in the thermoelectric products line of a small company in the State of Sao Paulo

    Directory of Open Access Journals (Sweden)

    Fernanda Veríssimo Soulé

    2016-03-01

    Full Text Available Quick Response Manufacturing (QRM is a way manufacturing companies may increase their flexibility. Manufacturing flexibility is a key to differentiation and enhancement of competitiveness. There is few empirical research on the topic of how small and medium-sized enterprises (SME may benefit from QRM, what may impact the appropriation of this approach by these important actors of our economy. This article aims to present the results of a project which applied QRM to reduce the lead time of a small company located in the state of Sao Paulo. It was proposed to a balance the throughputs of slow operations, reducing 50% of production batches; b implement cellular manufacturing and improvements in the management of Work In Process, using the POLCA system and visual management; c implement an integrated sales and operations planning (S&OP and rules for prioritization of orders. It was identified that the proposal would generate a lead time reduction from 39 to 21.3 days and a decrease of at least 51% in the raw materials stock costs. During the research, the following conclusions could be drawn: a problems in management, investment capacity and relationship with suppliers are frequent in family-owned SMEs; b QRM approach can be adapted to work within this environment; c the knowledge developed in academia can be an important tool to help family-owned SMEs to supplant these obstacles.

  9. Examination of lead concentrations in new decorative enamel paints in four countries with different histories of activity in lead paint regulation

    Energy Technology Data Exchange (ETDEWEB)

    Clark, C. Scott, E-mail: clarkcs@ucmail.uc.edu [Department of Environmental Health, University of Cincinnati (United States); International POPS Elimination Network (IPEN), San Francisco (United States); Kumar, Abhay; Mohapatra, Piyush; Rajankar, Prashant [Toxics Link, New Delhi (India); Nycz, Zuleica [APROMAC Environmental Protection Association and Toxisphera Environmental Health Association, Curitiba, Parana (Brazil); Hambartsumyan, Amalia [Greenwomen, Almaty (Kazakhstan); Astanina, Lydia [Khazer Ecological and Cultural Non-Governmental Organization, Yerevan (Armenia); Roda, Sandy; Lind, Caroline; Menrath, William; Peng, Hongying [Department of Environmental Health, University of Cincinnati (United States)

    2014-07-15

    current study and those available from other studies 24 of 28 paints from major brands in India decreased from high concentrations to 90 ppm or lower. Since lead concentrations in golden yellow paints from these brands were found to decrease to ≤90 ppm, it is possible that all 28 of these paints now contain ≤90 ppm since yellow paints usually have the highest lead concentrations. Other brands in Brazil and India that have been analyzed only one time had lead concentrations up to 59,000 ppm and 134,000 ppm, respectively. Less than one-third of the paints had notations on their labels with information about lead content and these were sometimes inaccurate. The label from one brand indicating “no added lead” contained paint with 134,000 ppm lead, the highest found in this study. Three percent (3 of 98) of the paints with surface lead loading that did not exceed 2 µg/cm{sup 2}, the limit established by the Consumer Product Safety Improvement Act for small areas on toys, contained greater than 90 ppm lead and thus were false negatives. Of the new paint samples that contained ≤600 ppm, 88% contained ≤90 ppm. Of the samples that contained ≤90 ppm, 97% contained ≤45 ppm and 92% contained ≤15 ppm. Based on these data it appears to be technically feasible to manufacture paints containing ≤90 ppm and in many cases to produce paints that have lead concentrations that do not exceed 15 ppm. - Highlights: • Brazilian paints with high lead (avg. 36,000 ppm) contained <9 ppm after regulation. • Lead in major Indian paint brands decreased to low levels by efforts of NGOs/others. • Most paints with lead ≤600 ppm also are ≤90 ppm and many also ≤15 ppm. • At the CPSIA limit of 2 µg Pb/cm{sup 2} for small areas on toys, 3% exceeded 90 ppm lead. • Most paint brands in Armenia and Kazakhstan based/manufactured outside the country.

  10. Do Declining Discount Rates lead to Time Inconsistent Economic Advice?

    DEFF Research Database (Denmark)

    Hansen, Anders Chr.

    2006-01-01

    This paper addresses the risk of time inconsistency in economic appraisals related to the use of hyperbolic discounting (declining discount rates) instead of exponential discounting (constant discount rate). Many economists are uneasy about the prospects of potential time inconsistency. The paper...

  11. The analysis of QT interval and repolarization morphology of the heart in chronic exposure to lead.

    Science.gov (United States)

    Kiełtucki, J; Dobrakowski, M; Pawlas, N; Średniawa, B; Boroń, M; Kasperczyk, S

    2017-10-01

    There are no common recommendations regarding electrocardiographic monitoring in occupationally exposed workers. Therefore, the present study was designed to investigate whether exposure to lead results in an increase of selected electrocardiography (ECG) pathologies, such as QT interval prolongation and repolarization disorders, in occupationally exposed workers. The study group included 180 workers occupationally exposed to lead compounds. The exposed group was divided according to the median of the mean blood lead level (PbB mean ) calculated based on a series of measurements performed during 5-year observation period (35 µg/dl) into two subgroups: low exposure (LE, PbB mean = 20.0-35.0 µg/dl) and high exposure (HE, PbB mean = 35.1-46.4 µg/dl). The control group consisted of 69 healthy workers without occupational exposure to lead. ECG evaluation included the analysis of heart rate (HR), QT interval and repolarization abnormalities. Mean QT interval was significantly greater in the exposed population than in the control group by 2%. In the HE group, mean QT interval was significantly greater than in the control group by 4% and significantly different from those noted in the LE group. Positive correlations between QT interval and lead exposure indices were also reported. Besides, there was a negative correlation between HR and blood lead level. Increased concentration of lead in the blood above 35 μg/dl is associated with the QT interval prolongation, which may trigger arrhythmias when combined with other abnormalities, such as long QT syndrome. Therefore, electrocardiographic evaluation should be a part of a routine monitoring of occupationally exposed populations.

  12. Lead diffusion in monazite; Diffusion du plomb dans la monazite

    Energy Technology Data Exchange (ETDEWEB)

    Gardes, E

    2006-06-15

    Proper knowledge of the diffusion rates of lead in monazite is necessary to understand the U-Th-Pb age anomalies of this mineral, which is one of the most used in geochronology after zircon. Diffusion experiments were performed in NdPO{sub 4} monocrystals and in Nd{sub 0.66}Ca{sub 0.17}Th{sub 0.17}PO{sub 4} polycrystals from Nd{sub 0.66}Pb{sub 0.17}Th{sub 0.17}PO{sub 4} thin films to investigate Pb{sup 2+} + Th{sup 4+} {r_reversible} 2 Nd{sup 3+} and Pb{sup 2+} {r_reversible} Ca{sup 2+} exchanges. Diffusion annealings were run between 1200 and 1500 Celsius degrees, at room pressure, for durations ranging from one hour to one month. The diffusion profiles were analysed using TEM (transmission electronic microscopy) and RBS (Rutherford backscattering spectroscopy). The diffusivities extracted for Pb{sup 2+} + Th{sup 4+} {r_reversible} 2 Nd{sup 3+} exchange follow an Arrhenius law with parameters E equals 509 {+-} 24 kJ mol{sup -1} and log(D{sub 0} (m{sup 2}s{sup -1})) equals -3.41 {+-} 0.77. Preliminary data for Pb{sup 2+} {r_reversible} Ca{sup 2+} exchange are in agreement with this result. The extrapolation of our data to crustal temperatures yields very slow diffusivities. For instance, the time necessary for a 50 {mu}m grain to lose all of its lead at 800 Celsius degrees is greater than the age of the Earth. From these results and other evidence from the literature, we conclude that most of the perturbations in U-Th-Pb ages of monazite cannot be attributed to lead diffusion, but rather to interactions with fluids. (author)

  13. Short- and Long-Term Lead Release after Partial Lead Service Line Replacements in a Metropolitan Water Distribution System.

    Science.gov (United States)

    Deshommes, Elise; Laroche, Laurent; Deveau, Dominique; Nour, Shokoufeh; Prévost, Michèle

    2017-09-05

    Thirty-three households were monitored in a full-scale water distribution system, to investigate the impact of recent (sampling over a period of 1-20 months. Point-of-entry filters were installed to capture sporadic release of particulate lead from the lead service lines (LSLs). Mean concentrations increased immediately after PLSLRs and erratic particulate lead spikes were observed over the 18 month post-PLSLR monitoring period. The mass of lead released during this time frame indicates the occurrence of galvanic corrosion and scale destabilization. System-wide, lead concentrations were however lower in households with PLSLRs as compared to those with no replacement, especially for old PLSLRs. Nonetheless, 61% of PLSLR samples still exceeded 10 μg/L, reflecting the importance of implementing full LSL replacement and efficient risk communication. Acute concentrations measured immediately after PLSLRs demonstrate the need for appropriate flushing procedures to prevent lead poisoning.

  14. Lindblad-driven discretized leads for nonequilibrium steady-state transport in quantum impurity models: Recovering the continuum limit

    Science.gov (United States)

    Schwarz, F.; Goldstein, M.; Dorda, A.; Arrigoni, E.; Weichselbaum, A.; von Delft, J.

    2016-10-01

    The description of interacting quantum impurity models in steady-state nonequilibrium is an open challenge for computational many-particle methods: the numerical requirement of using a finite number of lead levels and the physical requirement of describing a truly open quantum system are seemingly incompatible. One possibility to bridge this gap is the use of Lindblad-driven discretized leads (LDDL): one couples auxiliary continuous reservoirs to the discretized lead levels and represents these additional reservoirs by Lindblad terms in the Liouville equation. For quadratic models governed by Lindbladian dynamics, we present an elementary approach for obtaining correlation functions analytically. In a second part, we use this approach to explicitly discuss the conditions under which the continuum limit of the LDDL approach recovers the correct representation of thermal reservoirs. As an analytically solvable example, the nonequilibrium resonant level model is studied in greater detail. Lastly, we present ideas towards a numerical evaluation of the suggested Lindblad equation for interacting impurities based on matrix product states. In particular, we present a reformulation of the Lindblad equation, which has the useful property that the leads can be mapped onto a chain where both the Hamiltonian dynamics and the Lindblad driving are local at the same time. Moreover, we discuss the possibility to combine the Lindblad approach with a logarithmic discretization needed for the exploration of exponentially small energy scales.

  15. The optimum lead thickness for lead-activation detectors

    International Nuclear Information System (INIS)

    Si Fenni; Hu Qingyuan

    2009-01-01

    The optimum lead thickness for lead-activation detectors has been studied in this paper. First existence of the optimum lead thickness is explained theoretically. Then the optimum lead thickness is obtained by two methods, MCNP5 calculation and mathematical estimation. At last factors which affect the optimum lead thickness are discussed. It turns out that the optimum lead thickness is irrelevant to incident neutron energies. It is recommended 2.5 cm generally.

  16. Fractures of the greater trochanter following total hip replacement.

    Science.gov (United States)

    Brun, Ole-Christian L; Maansson, Lukas

    2013-01-01

    We studied the incidence of greater trochanteric fractures at our department following THR. In all we examined 911 patients retrospectively and found the occurance of a greater trochanteric fracture to be 3%. Patients with fractures had significantly poorer outcome on Oxford Hip score, Pain VAS, Satisfaction VAS and EQ-5D compared to THR without fractures. Greater trochanteric fracture following THR is one of the most common complications following THR. It has previously been thought to have little impact on the overall outcome following THR, but our study suggests otherwise.

  17. Coevolution between Hispaniolan crossbills and pine: does more time allow for greater phenotypic escalation at lower latitude?

    Science.gov (United States)

    Parchman, Thomas L; Benkman, Craig W; Mezquida, Eduardo T

    2007-09-01

    Crossbills (Aves: Loxia) and several conifers have coevolved in predator-prey arms races over the last 10,000 years. However, the extent to which coevolutionary arms races have contributed to the adaptive radiation of crossbills or to any other adaptive radiation is largely unknown. Here we extend our previous studies of geographically structured coevolution by considering a crossbill-conifer interaction that has persisted for a much longer time period and involves a conifer with more variable annual seed production. We examined geographic variation in the cone and seed traits of two sister species of pines, Pinus occidentalis and P. cubensis, on the islands of Hispaniola and Cuba, respectively. We also compared the Hispaniolan crossbill (Loxia megaplaga) to its sister taxa the North American white-winged crossbill (Loxia leucoptera leucoptera). The Hispaniolan crossbill is endemic to Hispaniola whereas Cuba lacks crossbills. In addition and in contrast to previous studies, the variation in selection experienced by these pines due to crossbills is not confounded by the occurrence of selection by tree squirrels (Tamiasciurus and Sciurus). As predicted if P. occidentalis has evolved defenses in response to selection exerted by crossbills, cones of P. occidentalis have scales that are 53% thicker than those of P. cubensis. Cones of P. occidentalis, but not P. cubensis, also have well-developed spines, a known defense against vertebrate seed predators. Consistent with patterns of divergence seen in crossbills coevolving locally with other conifers, the Hispaniolan crossbill has evolved a bill that is 25% deeper than the white-winged crossbill. Together with phylogenetic analyses, our results suggest that predator-prey coevolution between Hispaniolan crossbills and P. occidentalis over approximately 600,000 years has caused substantial morphological evolution in both the crossbill and pine. This also indicates that cone crop fluctuations do not prevent crossbills and

  18. Particle migration leads to deposition-free fractionation

    NARCIS (Netherlands)

    Dinther, van A.M.C.; Schroën, C.G.P.H.; Boom, R.M.

    2013-01-01

    In membrane filtration, theporesizeofthemembranedeterminesthesizeof ‘particles’ that shouldbe rejected,leading to accumulation of particles on the membrane surface and changed particle retention in time.A process without accumulation and thereby constant retention as function of time would be well

  19. Greater temperature sensitivity of plant phenology at colder sites

    DEFF Research Database (Denmark)

    Prevey, Janet; Vellend, Mark; Ruger, Nadja

    2017-01-01

    Warmer temperatures are accelerating the phenology of organisms around the world. Temperature sensitivity of phenology might be greater in colder, higher latitude sites than in warmer regions, in part because small changes in temperature constitute greater relative changes in thermal balance...

  20. Lead line in rodents: an old sign of lead intoxication turned into a new method for environmental surveillance.

    Science.gov (United States)

    de Figueiredo, Fellipe Augusto Tocchini; Ramos, Junia; Kawakita, Erika R Hashimoto; Bilal, Alina S; de Sousa, Frederico B; Swaim, William D; Issa, Joao P Mardegan; Gerlach, Raquel F

    2016-11-01

    The "lead line" was described by Henry Burton in 1840. Rodents are used as sentinels to monitor environmental pollution, but their teeth have not been used to determine lead. To determine whether lead deposits can be observed in the teeth of lead-exposed animals, since the gingival deposits known as "lead line" would likely have a correlate in the calcified tissue to which the gums are opposed during life. Male Wistar rats were exposed to lead in the drinking water (30 mg/L) since birth until 60 days-old. Molars and the incisors of each hemimandible were analyzed by scanning electron microscopy (SEM) on regular and backscattered electrons (BSE) mode. Elements were determined using electron dispersive spectroscopy (EDS). Clean cervical margins were observed on control teeth, as opposed to the findings of extensive deposits on lead-exposed animals, even in hemimandibles that had been exhumed after being buried for 90 days. BSE/EDS indicated that those deposits were an exogenous material compatible with lead sulfite. Presence of calcium, phosphorus, magnesium, carbon, lead, and oxygen is presented. Lead-exposed animals presented marked root resorption. The lead deposits characterized here for the first time show that the "lead line" seen in gums has a calcified tissue counterpart, that is detectable post-mortem even in animals exposed to a low dose of lead. This is likely a good method to detect undue lead exposure and will likely have wide application for pollution surveillance using sentinels.

  1. Greater Somalia, the never-ending dream?

    DEFF Research Database (Denmark)

    Zoppi, Marco

    2015-01-01

    This paper provides an historical analysis of the concept of Greater Somalia, the nationalist project that advocates the political union of all Somali-speaking people, including those inhabiting areas in current Djibouti, Ethiopia and Kenya. The Somali territorial unification project of “lost...

  2. Hydrogen extraction from liquid lithium-lead alloy by bubbling with rotational jet nozzle

    International Nuclear Information System (INIS)

    Xie Bo; Yang Tongzai; Guan Rui; Weng Kuiping

    2010-01-01

    The technology of tritium extraction from lithium-lead alloy has been simulated, hydrogen extraction from lithium-lead alloy by bubbling with rotational jet nozzle being used to simulate tritium in the study based on the introduction of fluid dynamics to establish algebraic model. The results show that the higher than lithium-lead melting temperature, the higher cumulative hydrogen extraction efficiency, and gas holdup of bubble column is little affected by the impeller diameter. Gas holdup when using small aperture is slightly higher when using large aperture only at a high helium flow rate, but the smaller the aperture, the greater the bubble surface area, and a marked increase in intensity of flow circulation for liquid lithium-lead with the increase of helium flow rate, hydrogen extraction rate increases too. Moreover, influence of the jet rotational velocity on hydrogen extraction is limited. (authors)

  3. Contribution of lead and thorium to the history of the Oklo reactors

    International Nuclear Information System (INIS)

    Devillers, C.; Menes, J.

    1978-01-01

    The authors report the results of measuring lead and thorium in a series of representative samples of the superconcentrations of uranium found in the Oklo mineralization. Interpretation of the data reveals the complexity of the history of lead in the deposit, but makes it possible to derive a number of important facts, namely early disturbance and recent, massive remobilization of lead. One is led to conclude that the date of the uranium emplacement may be greater than 1900 million years. The absence of high thorium contents in the ''normal'' rich ore confirms the importance of dating the nuclear reaction on the basis of the Th/U balance. This determination, which draws on the same set of data as for the Nd/U balance, gives a mean value close to 1930 million years. (author)

  4. Lead and eagles: demographic and pathological characteristics of poisoning, and exposure levels associated with other causes of mortality

    Science.gov (United States)

    Franson, J. Christian; Russell, Robin E.

    2014-01-01

    We conducted a retrospective analysis to evaluate demographic and pathologic characteristics in 484 bald eagles (Haliaeetus leucocephalus) and 68 golden eagles (Aquila chrysaetos) diagnosed with lead poisoning at the U.S. Geological Survey National Wildlife Health Center. As part of our analysis, we compared characteristics of lead poisoned eagles with those that died of other causes. Odds of lead poisoning were greater for bald eagles versus golden eagles, females versus males, adults versus juveniles, and eagles from the Mississippi and Central flyways versus the Atlantic and Pacific flyways. In addition to spatial, species, and demographic associations, we detected a distinct temporal trend in the collection date of lead poisoned bald eagle carcasses. These carcasses were found at greater frequency in late autumn and winter than spring and summer. Lesions in lead poisoned birds included emaciation, evidence of bile stasis, myocardial degeneration and necrosis, and renal tubular nephrosis and necrosis. Ingested lead ammunition or fragments were found in 14.2 % of bald eagles and 11.8 % of golden eagles. The overall mean liver lead concentration (wet weight basis) for eagles diagnosed with lead poisoning was 28.9 ± 0.69 SE mg/kg in bald eagles and 19.4 ± 1.84 SE mg/kg in golden eagles. In eagles diagnosed with collision trauma, electrocution, poisoning (other than lead), emaciation, infectious disease, trapping death, other, and undetermined causes, average liver lead concentrations were low (<1 mg/kg) and did not differ among causes of mortality. Thus, based on our data, we found no evidence that lead exposure of eagles predisposed them to other causes of mortality.

  5. Extraction of lead from waste CRT funnel glass by generating lead sulfide - An approach for electronic waste management.

    Science.gov (United States)

    Hu, Biao; Hui, Wenlong

    2017-09-01

    Waste cathode ray tube (CRT) funnel glass is the key and difficult points in waste electrical and electronic equipment (WEEE) disposal. In this paper, a novel and effective process for the detoxification and reutilization of waste CRT funnel glass was developed by generating lead sulfide precipitate via a high-temperature melting process. The central function in this process was the generation of lead sulfide, which gathered at the bottom of the crucible and was then separated from the slag. Sodium carbonate was used as a flux and reaction agent, and sodium sulfide was used as a precipitating agent. The experimental results revealed that the lead sulfide recovery rate initially increased with an increase in the amount of added sodium carbonate, the amount of sodium sulfide, the temperature, and the holding time and then reached an equilibrium value. The maximum lead sulfide recovery rate was approximately 93%, at the optimum sodium carbonate level, sodium sulfide level, temperature, and holding time of 25%, 8%, 1200°C, and 2h, respectively. The glass slag can be made into sodium and potassium silicate by hydrolysis in an environmental and economical process. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Assessing Human Impacts on the Greater Akaki River, Ethiopia ...

    African Journals Online (AJOL)

    We assessed the impacts of human activities on the Greater Akaki River using physicochemical parameters and macroinvertebrate metrics. Physicochemical samples and macroinvertebrates were collected bimonthly from eight sites established on the Greater Akaki River from February 2006 to April 2006. Eleven metrics ...

  7. Molecular insights into the biology of Greater Sage-Grouse

    Science.gov (United States)

    Oyler-McCance, Sara J.; Quinn, Thomas W.

    2011-01-01

    Recent research on Greater Sage-Grouse (Centrocercus urophasianus) genetics has revealed some important findings. First, multiple paternity in broods is more prevalent than previously thought, and leks do not comprise kin groups. Second, the Greater Sage-Grouse is genetically distinct from the congeneric Gunnison sage-grouse (C. minimus). Third, the Lyon-Mono population in the Mono Basin, spanning the border between Nevada and California, has unique genetic characteristics. Fourth, the previous delineation of western (C. u. phaios) and eastern Greater Sage-Grouse (C. u. urophasianus) is not supported genetically. Fifth, two isolated populations in Washington show indications that genetic diversity has been lost due to population declines and isolation. This chapter examines the use of molecular genetics to understand the biology of Greater Sage-Grouse for the conservation and management of this species and put it into the context of avian ecology based on selected molecular studies.

  8. Study on damage of DNA in mice induced by mercury cadmium and/or lead

    International Nuclear Information System (INIS)

    Hu Xiaopan; Zhou Jianhua; Shi Xijing; Yan Liping

    2004-01-01

    Objective: To explore the joint injury actions of mercury, cadmium and/or lead on DNA in peripheral blood lymphocytes of mice. Methods: The blood specimens were obtained from mice at the 2 day after the peritoneal injections. DNA damages were determined by single cell gel electrophoresis (SCGE) and 3 H-TdR incorporation. Results: Acquired by SCGE technique, tail movement of DNA in mercury-cadmium-lead group was significantly greater than that in the single exposure group, the difference was significant too between mercury-cadmium group and cadmium group, cadmium-lead group and cadmium group. The results of 3 H-TdR incorporation showed: the values of DPM in mercury-cadmium group and cadmium-lead group were lower than that in the single exposure group and the value of DPM lowered more significantly after exposure to mercury-cadmium-lead. Conclusion: The combined effects of mercury, cadmium, lead on DNA damage are more significant. (author)

  9. Geochemistry of manganese, iron, uranium, lead-210 and major ions in the Susquehanna River

    International Nuclear Information System (INIS)

    Lewis, D.M.

    1976-01-01

    The change in water composition accompanying a change in discharge of large streams and the Susquehanna River results from the change in the proportions of the total flow composed of type waters of constant composition. This change in the flow proportions is due to the different hydrologic responses to precipitation inputs of basins underlain by different single rock types. The in-river precipitation of mine-drainage-injected Mn and Fe was studied at a pH of approximately 7. For Mn the removal from solution appears to be first order. The rate constant is 10 3 times greater than the extrapolated autocatalytic rate constant of previous laboratory experiments. The study of the removal of Fe from solution yields a first order rate constant consistent with previous laboratory experiments. Lead-210 was used as a natural tracer to study the fate of trace metals

  10. INDUSTRIAL LAND DEVELOPMENT AND MANUFACTURING DECONCENTRATION IN GREATER JAKARTA

    NARCIS (Netherlands)

    Hudalah, Delik; Viantari, Dimitra; Firman, Tommy; Woltjer, Johan

    2013-01-01

    Industrial land development has become a key feature of urbanization in Greater Jakarta, one of the largest metropolitan areas in Southeast Asia. Following Suharto's market-oriented policy measures in the late 1980s, private developers have dominated the land development projects in Greater Jakarta.

  11. Taphonomic trade-offs in tropical marine death assemblages: Differential time averaging, shell loss, and probable bias in siliciclastic vs. carbonate facies

    Science.gov (United States)

    Kidwell, Susan M.; Best, Mairi M. R.; Kaufman, Darrell S.

    2005-09-01

    Radiocarbon-calibrated amino-acid racemization ages of individually dated bivalve mollusk shells from Caribbean reef, nonreefal carbonate, and siliciclastic sediments in Panama indicate that siliciclastic sands and muds contain significantly older shells (median 375 yr, range up to ˜5400 yr) than nearby carbonate seafloors (median 72 yr, range up to ˜2900 yr; maximum shell ages differ significantly at p < 0.02 using extreme-value statistics). The implied difference in shell loss rates is contrary to physicochemical expectations but is consistent with observed differences in shell condition (greater bioerosion and dissolution in carbonates). Higher rates of shell loss in carbonate sediments should lead to greater compositional bias in surviving skeletal material, resulting in taphonomic trade-offs: less time averaging but probably higher taxonomic bias in pure carbonate sediments, and lower bias but greater time averaging in siliciclastic sediments from humid-weathered accretionary arc terrains, which are a widespread setting of tropical sedimentation.

  12. Radiation effects on lead silicate glass surfaces

    International Nuclear Information System (INIS)

    Wang, P.W.; Zhang, L.P.; Borgen, N.; Pannell, K.

    1996-01-01

    Radiation-induced changes in the microstructure of lead silicate glass were investigated in situ under Mg K α irradiation in an ultra-high vacuum (UHV) environment by X-ray photoelectron spectroscopy (XPS). Lead-oxygen bond breaking resulting in the formation of pure lead was observed. The segregation, growth kinetics and the structural relaxation of the lead, with corresponding changes in the oxygen and silicon on the glass surfaces were studied by measuring the time-dependent changes in concentration, binding energy shifts, and the full width at half maximum. A bimodal distribution of the oxygen XPS signal, caused by bridging and non-bridging oxygens, was found during the relaxation process. All experimental data indicate a reduction of the oxygen concentration, a phase separation of the lead from the glass matrix, and the metallization of the lead occurred during and after the X-ray irradiation. (author)

  13. Identification of appropriate lags and temporal resolutions for low flow indicators in the River Rhine to forecast low flows with different lead times

    NARCIS (Netherlands)

    Demirel, M.C.; Booij, Martijn J.; Hoekstra, Arjen Ysbert

    2013-01-01

    The aim of this paper is to assess the relative importance of low flow indicators for the River Rhine and to identify their appropriate temporal lag and resolution. This is done in the context of low flow forecasting with lead times of 14 and 90 days. First, the Rhine basin is subdivided into seven

  14. Comparison of three jet events to predictions from a next-to-leading order calculation

    Energy Technology Data Exchange (ETDEWEB)

    Brandl, Alexander [Univ. of New Mexico, Albuquerque, NM (United States)

    2002-01-01

    The properties of three-jet events in data of integrated luminosity 86±4 pb-1 from CDF Run 1b and with total transverse energy greater than 175 GeV have been analyzed and compared to predictions from a next-to-leading order perturbative QCD calculation.

  15. Time trends in burdens of cadmium, lead, and mercury in the population of northern Sweden

    International Nuclear Information System (INIS)

    Wennberg, Maria; Lundh, Thomas; Bergdahl, Ingvar A.; Hallmans, Goeran; Jansson, Jan-Hakan; Stegmayr, Birgitta; Custodio, Hipolito M.; Skerfving, Staffan

    2006-01-01

    The time trends of exposure to heavy metals are not adequately known. This is a worldwide problem with regard to the basis for preventive actions and evaluation of their effects. This study addresses time trends for the three toxic elements cadmium (Cd), mercury (Hg), and lead (Pb). Concentrations in erythrocytes (Ery) were determined in a subsample of the population-based MONICA surveys from 1990, 1994, and 1999 in a total of 600 men and women aged 25-74 years. The study took place in the two northernmost counties in Sweden. To assess the effect of changes in the environment, adjustments were made for life-style factors that are determinants of exposure. Annual decreases of 5-6% were seen for Ery-Pb levels (adjusted for age and changes in alcohol intake) and Ery-Hg levels (adjusted for age and changes in fish intake). Ery-Cd levels (adjusted for age) showed a similar significant decrease in smoking men. It is concluded that for Pb and maybe also Hg the actions against pollution during recent decades have caused a rapid decrease of exposure; for Hg the decreased use of dental amalgam may also have had an influence. For Cd, the decline in Ery-Cd was seen only in smokers, indicating that Cd exposure from tobacco has decreased, while other environmental sources of Cd have not changed significantly. To further improve the health status in Sweden, it is important to decrease the pollution of Cd, and actions against smoking in the community are important

  16. Call to action: Better care, better health, and greater value in college health.

    Science.gov (United States)

    Ciotoli, Carlo; Smith, Allison J; Keeling, Richard P

    2018-03-05

    It is time for action by leaders across higher education to strengthen quality improvement (QI) in college health, in pursuit of better care, better health, and increased value - goals closely linked to students' learning and success. The size and importance of the college student population; the connections between wellbeing, and therefore QI, and student success; the need for improved standards and greater accountability; and the positive contributions of QI to employee satisfaction and professionalism all warrant a widespread commitment to building greater capacity and capability for QI in college health. This report aims to inspire, motivate, and challenge college health professionals and their colleagues, campus leaders, and national entities to take both immediate and sustainable steps to bring QI to the forefront of college health practice - and, by doing so, to elevate care, health, and value of college health as a key pathway to advancing student success.

  17. From virtuality to reality - Virtual screening in lead discovery and lead optimization: a medicinal chemistry perspective.

    Science.gov (United States)

    Rester, Ulrich

    2008-07-01

    Drug discovery and development is an interdisciplinary, expensive and time-consuming process. Scientific advancements during the past two decades have altered the way pharmaceutical research produces novel bio-active molecules. Advances in computational techniques and hardware solutions have enabled in silico methods, and in particular virtual screening, to speed up modern lead identification and lead optimization. Recent successes have proven the power of combining virtual screening with complementary and synergistic biophysical methods, such as X-ray crystallography, NMR spectroscopy and isothermal titration calorimetry (ITC). This review addresses key issues, challenges and recent improvements of virtual screening methods and strategies. Examples highlighting the impact of an integrated virtual screening and biophysical characterization platform in the lead identification and optimization process are presented and discussed.

  18. Delayed visual maturation is not from lead pollution

    International Nuclear Information System (INIS)

    Gulson, B.L.; Howarth, D.

    2000-01-01

    Delayed visual maturation, a term introduced by Illingworth (1961), was first described by Beauvieux in 1926. Patients with delayed visual maturation are found to be blind soon after birth and, if it is the only defect, the vision improves by the time the child is 6 months of age. Since first described, numerous cases have been reported but so far no cause has been found. The diagnosis of three infants with delayed visual maturation in a period of 19 months, in the lead mining community of Broken Hill, raised the possibility of a common cause. Two of the families lived in the most heavily polluted area of the town and were renovating their lead-contaminated houses while the wife was pregnant. The diagnosis of delayed visual maturation was made on the following characteristics:(1) poor visual attention at or soon after birth; (2) normal ocular examination; (3) visual response occurring by 5 to 6 months of age. Once the diagnosis was established, the parents were requested to retain any teeth the children lost for lead isotope and lead concentration analysis. Gulson and Wilson (1994) and Gulson (1996) demonstrated the use of the lead isotope technique, combined with the well-established histology of teeth, in evaluating in utero and early childhood lead exposure from slices of deciduous teeth. In this approach, analysis of the enamel provides evidence of in utero exposure. Analysis of dentine provides evidence of exposure during the early childhood years, when hand-to-mouth activity is usually an important contributor to lead body burden, and potentially up to the time of tooth loss. The lead isotope technique uses the four isotopes of lead. Three are the stable end products of radioactive decay of uranium and thorium: 238 U to 206 Pb, 235 U to 207 Pb, and 232 Th to 208 Pb. The abundance of the fourth, 204 Pb, has been essentially constant since the Earth began and this isotope is commonly used as a reference isotope. Because three isotopes of lead are produced by

  19. Lead poisoning

    Energy Technology Data Exchange (ETDEWEB)

    Beijers, J A

    1952-01-01

    Three cases of acute lead poisoning of cattle herds via ingestion are reported, and reference is made to several other incidents of lead in both humans and animals. The quantity of lead which was found in the livers of the dead cows varied from 6.5 to 19 mg/kg, while 1160 mg/kg of lead in the liver was found for a young cow which was poisoned experimentally with 5 gms of lead acetate per day; hence, there appears to be great variability in the amounts deposited that can lead to intoxication and death. No evidence was found for a lead seam around the teeth, prophyrinuria, or basophil granules in the erythrocytes during acute or chronic lead poisoning of cattle or horses examined. Reference is made to attempts of finding the boundary line between increased lead absorption and lead intoxication in humans, and an examination of 60 laborers in an offset-printing office containing a great deal of inhalable lead (0.16 to 1.9 mg/cu m air) is reviewed. Physical deviation, basophylic granulation of erythrocytes, increased lead content of the urine, and porphyrinuria only indicate an increased absorption of lead; the use of the term intoxication is justified if, in addition, there are complaints of lack of appetite, constipation, fatigue, abdominal pain, and emaciation.

  20. The H1 lead/scintillating-fibre calorimeter

    International Nuclear Information System (INIS)

    Appuhn, R.D.; Arndt, C.; Barrelet, E.

    1996-08-01

    The backward region of the H1 detector has been upgraded in order to provide improved measurement of the scattered electron in deep inelastic scattering events. The centerpiece of the upgrade is a high-resolution lead/scintillating-fibre calorimeter. The main design goals of the calorimeter are: good coverage of the region close to the beam pipe, high angular resolution and energy resolution of better than 2% for 30 GeV electrons. The calorimeter should be capable of providing coarse hadronic energy measurement and precise time information to suppress out-of-time background events at the first trigger level. It must be compact due to space restrictions. These requirements were fulfilled by constructing two separate calorimeter sections. The inner electromagnetic section is made of 0.5 mm scintillating plastic fibres embedded in a lead matrix. Its lead-to-fibre ratio is 2.3:1 by volume. The outer hadronic section consists of 1.0 mm diameter fibres with a lead-to-fibre ratio of 3.4:1. The mechanical construction of the new calorimeter and its assembly in the H1 detector are described. (orig.)

  1. The H1 lead/scintillating-fibre calorimeter

    International Nuclear Information System (INIS)

    Appuhn, R.-D.; Arndt, C.; Barrelet, E.

    1997-01-01

    The backward region of the H1 detector has been upgraded in order to provide improved measurement of the scattered electron in deep inelastic scattering events. The centerpiece of the upgrade is a high-resolution lead/scintillating-fibre calorimeter. The main design goals of the calorimeter are: good coverage of the region close to the beam pipe, high angular resolution and energy resolution of better than 2% for 30 GeV electrons. The calorimeter should be capable of providing coarse hadronic energy measurement and precise time information to suppress out-of-time background events at the first trigger level. It must be compact due to space restrictions. These requirements were fulfilled by constructing two separate calorimeter sections. The inner electromagnetic section is made of 0.5 mm scintillating plastic fibres embedded in a lead matrix. Its lead-to-fibre ratio is 2.3:1 by volume. The outer hadronic section consists of 1.0 mm diameter fibres with a lead-to-fibre ratio of 3.4:1. The mechanical construction of the new calorimeter and its assembly in the H1 detector are described. (orig.)

  2. Strategies for Talent Management: Greater Philadelphia Companies in Action

    Science.gov (United States)

    Council for Adult and Experiential Learning (NJ1), 2008

    2008-01-01

    Human capital is one of the critical issues that impacts the Greater Philadelphia region's ability to grow and prosper. The CEO Council for Growth (CEO Council) is committed to ensuring a steady and talented supply of quality workers for this region. "Strategies for Talent Management: Greater Philadelphia Companies in Action" provides…

  3. Greater oil investment opportunities

    International Nuclear Information System (INIS)

    Arenas, Ismael Enrique

    1997-01-01

    Geologically speaking, Colombia is a very attractive country for the world oil community. According to this philosophy new and important steps are being taken to reinforce the oil sector: Expansion of the exploratory frontier by including a larger number of sedimentary areas, and the adoption of innovative contracting instruments. Colombia has to offer, Greater economic incentives for the exploration of new areas to expand the exploratory frontier, stimulation of exploration in areas with prospectivity for small fields. Companies may offer Ecopetrol a participation in production over and above royalties, without it's participating in the investments and costs of these fields, more favorable conditions for natural gas seeking projects, in comparison with those governing the terms for oil

  4. Large polarons in lead halide perovskites

    OpenAIRE

    Miyata, Kiyoshi; Meggiolaro, Daniele; Trinh, M. Tuan; Joshi, Prakriti P.; Mosconi, Edoardo; Jones, Skyler C.; De Angelis, Filippo; Zhu, X.-Y.

    2017-01-01

    Lead halide perovskites show marked defect tolerance responsible for their excellent optoelectronic properties. These properties might be explained by the formation of large polarons, but how they are formed and whether organic cations are essential remain open questions. We provide a direct time domain view of large polaron formation in single-crystal lead bromide perovskites CH3NH3PbBr3 and CsPbBr3. We found that large polaron forms predominantly from the deformation of the PbBr3 ? framewor...

  5. Delayed appearance of tracer lead in facial hair

    International Nuclear Information System (INIS)

    Rabinowitz, M.; Wetherill, G.; Kopple, J.

    1976-01-01

    Three adult men were fed 204 Pb--a rare, stable isotope of lead--daily for about 100 days. Simultaneous blood and facial hair measurements of this tracer and of total lead concentrations were made by mass spectrometric isotope dilution analysis. Although the blood showed an immediate response to the intake of the tracer, the facial hair showed a more gradual response and a delay of approximately 35 days. Since the pattern of appearance of lead in hair does not appear to represent a simple time delay of blood lead concentration, the existence of a physiological pool of lead fed by the blood and giving rise to the content in hair is suggested. Hair lead values should therefore, be interpreted as the integral of the blood lead values over the mean life of this intermediate pool--about 100 days

  6. Synthesis of uniform nano-structured lead oxide by sonochemical method and its application as cathode and anode of lead-acid batteries

    International Nuclear Information System (INIS)

    Karami, Hassan; Karimi, Mohammad Ali; Haghdar, Saeed

    2008-01-01

    This paper discusses the results of a research aimed at investigating the synthesis of nano-structured lead oxide through reaction of lead nitrate solution and sodium carbonate solution by the sonochemical method. At the first, lead carbonate was obtained in a synthesized solution and then, after filtration, it was calcinated at the temperature of 320 deg. C so that nano-structured lead oxide can be produced. The effects of different parameters on particle size and morphology of final lead oxide powder were optimized by a 'one at a time' method. The prepared lead oxide powder was characterized by scanning electron microscopy (SEM), transmission electron spectroscopy (TEM) and X-ray diffraction (XRD). Under optimum conditions, uniformed and homogeneous nano-structured lead oxide powder with more spongy morphology and particle size of 20-40 nm was obtained. The synthesized lead oxide, as anode and cathode of lead-acid batteries, showed an excellent discharge capacity (140 mA h/g)

  7. Low dose influenza virus challenge in the ferret leads to increased virus shedding and greater sensitivity to oseltamivir.

    Science.gov (United States)

    Marriott, Anthony C; Dove, Brian K; Whittaker, Catherine J; Bruce, Christine; Ryan, Kathryn A; Bean, Thomas J; Rayner, Emma; Pearson, Geoff; Taylor, Irene; Dowall, Stuart; Plank, Jenna; Newman, Edmund; Barclay, Wendy S; Dimmock, Nigel J; Easton, Andrew J; Hallis, Bassam; Silman, Nigel J; Carroll, Miles W

    2014-01-01

    Ferrets are widely used to study human influenza virus infection. Their airway physiology and cell receptor distribution makes them ideal for the analysis of pathogenesis and virus transmission, and for testing the efficacy of anti-influenza interventions and vaccines. The 2009 pandemic influenza virus (H1N1pdm09) induces mild to moderate respiratory disease in infected ferrets, following inoculation with 106 plaque-forming units (pfu) of virus. We have demonstrated that reducing the challenge dose to 102 pfu delays the onset of clinical signs by 1 day, and results in a modest reduction in clinical signs, and a less rapid nasal cavity innate immune response. There was also a delay in virus production in the upper respiratory tract, this was up to 9-fold greater and virus shedding was prolonged. Progression of infection to the lower respiratory tract was not noticeably delayed by the reduction in virus challenge. A dose of 104 pfu gave an infection that was intermediate between those of the 106 pfu and 102 pfu doses. To address the hypothesis that using a more authentic low challenge dose would facilitate a more sensitive model for antiviral efficacy, we used the well-known neuraminidase inhibitor, oseltamivir. Oseltamivir-treated and untreated ferrets were challenged with high (106 pfu) and low (102 pfu) doses of influenza H1N1pdm09 virus. The low dose treated ferrets showed significant delays in innate immune response and virus shedding, delayed onset of pathological changes in the nasal cavity, and reduced pathological changes and viral RNA load in the lung, relative to untreated ferrets. Importantly, these observations were not seen in treated animals when the high dose challenge was used. In summary, low dose challenge gives a disease that more closely parallels the disease parameters of human influenza infection, and provides an improved pre-clinical model for the assessment of influenza therapeutics, and potentially, influenza vaccines.

  8. Low dose influenza virus challenge in the ferret leads to increased virus shedding and greater sensitivity to oseltamivir.

    Directory of Open Access Journals (Sweden)

    Anthony C Marriott

    Full Text Available Ferrets are widely used to study human influenza virus infection. Their airway physiology and cell receptor distribution makes them ideal for the analysis of pathogenesis and virus transmission, and for testing the efficacy of anti-influenza interventions and vaccines. The 2009 pandemic influenza virus (H1N1pdm09 induces mild to moderate respiratory disease in infected ferrets, following inoculation with 106 plaque-forming units (pfu of virus. We have demonstrated that reducing the challenge dose to 102 pfu delays the onset of clinical signs by 1 day, and results in a modest reduction in clinical signs, and a less rapid nasal cavity innate immune response. There was also a delay in virus production in the upper respiratory tract, this was up to 9-fold greater and virus shedding was prolonged. Progression of infection to the lower respiratory tract was not noticeably delayed by the reduction in virus challenge. A dose of 104 pfu gave an infection that was intermediate between those of the 106 pfu and 102 pfu doses. To address the hypothesis that using a more authentic low challenge dose would facilitate a more sensitive model for antiviral efficacy, we used the well-known neuraminidase inhibitor, oseltamivir. Oseltamivir-treated and untreated ferrets were challenged with high (106 pfu and low (102 pfu doses of influenza H1N1pdm09 virus. The low dose treated ferrets showed significant delays in innate immune response and virus shedding, delayed onset of pathological changes in the nasal cavity, and reduced pathological changes and viral RNA load in the lung, relative to untreated ferrets. Importantly, these observations were not seen in treated animals when the high dose challenge was used. In summary, low dose challenge gives a disease that more closely parallels the disease parameters of human influenza infection, and provides an improved pre-clinical model for the assessment of influenza therapeutics, and potentially, influenza vaccines.

  9. Observing expertise-related actions leads to perfect time flow estimations.

    Directory of Open Access Journals (Sweden)

    Yin-Hua Chen

    Full Text Available The estimation of the time of exposure of a picture portraying an action increases as a function of the amount of movement implied in the action represented. This effect suggests that the perceiver creates an internal embodiment of the action observed as if internally simulating the entire movement sequence. Little is known however about the timing accuracy of these internal action simulations, specifically whether they are affected by the level of familiarity and experience that the observer has of the action. In this study we asked professional pianists to reproduce different durations of exposure (shorter or longer than one second of visual displays both specific (a hand in piano-playing action and non-specific to their domain of expertise (a hand in finger-thumb opposition and scrambled-pixels and compared their performance with non-pianists. Pianists outperformed non-pianists independently of the time of exposure of the stimuli; remarkably the group difference was particularly magnified by the pianists' enhanced accuracy and stability only when observing the hand in the act of playing the piano. These results for the first time provide evidence that through musical training, pianists create a selective and self-determined dynamic internal representation of an observed movement that allows them to estimate precisely its temporal duration.

  10. Biosorption of lead phosphates by lead-tolerant bacteria as a mechanism for lead immobilization.

    Science.gov (United States)

    Rodríguez-Sánchez, Viridiana; Guzmán-Moreno, Jesús; Rodríguez-González, Vicente; Flores-de la Torre, Juan Armando; Ramírez-Santoyo, Rosa María; Vidales-Rodríguez, Luz Elena

    2017-08-01

    The study of metal-tolerant bacteria is important for bioremediation of contaminated environments and development of green technologies for material synthesis due to their potential to transform toxic metal ions into less toxic compounds by mechanisms such as reduction, oxidation and/or sequestration. In this study, we report the isolation of seven lead-tolerant bacteria from a metal-contaminated site at Zacatecas, México. The bacteria were identified as members of the Staphylococcus and Bacillus genera by microscopic, biochemical and 16S rDNA analyses. Minimal inhibitory concentration of these isolates was established between 4.5 and 7.0 mM of Pb(NO 3 ) 2 in solid and 1.0-4.0 mM of Pb(NO 3 ) 2 in liquid media. A quantitative analysis of the lead associated to bacterial biomass in growing cultures, revealed that the percentage of lead associated to biomass was between 1 and 37% in the PbT isolates. A mechanism of complexation/biosorption of lead ions as inorganic phosphates (lead hydroxyapatite and pyromorphite) in bacterial biomass, was determined by Fourier transform infrared spectroscopy and X-ray diffraction analyses. Thus, the ability of the lead-tolerant isolates to transform lead ions into stable and highly insoluble lead minerals make them potentially useful for immobilization of lead in mining waste.

  11. Improving greater trochanteric reattachment with a novel cable plate system.

    Science.gov (United States)

    Baril, Yannick; Bourgeois, Yan; Brailovski, Vladimir; Duke, Kajsa; Laflamme, G Yves; Petit, Yvan

    2013-03-01

    Cable-grip systems are commonly used for greater trochanteric reattachment because they have provided the best fixation performance to date, even though they have a rather high complication rate. A novel reattachment system is proposed with the aim of improving fixation stability. It consists of a Y-shaped fixation plate combined with locking screws and superelastic cables to reduce cable loosening and limit greater trochanter movement. The novel system is compared with a commercially available reattachment system in terms of greater trochanter movement and cable tensions under different greater trochanteric abductor application angles. A factorial design of experiments was used including four independent variables: plate system, cable type, abductor application angle, and femur model. The test procedure included 50 cycles of simultaneous application of an abductor force on the greater trochanter and a hip force on the femoral head. The novel plate reduces the movements of a greater trochanter fragment within a single loading cycle up to 26%. Permanent degradation of the fixation (accumulated movement based on 50-cycle testing) is reduced up to 46%. The use of superelastic cables reduces tension loosening up to 24%. However this last improvement did not result in a significant reduction of the grater trochanter movement. The novel plate and cables present advantages over the commercially available greater trochanter reattachment system. The plate reduces movements generated by the hip abductor. The superelastic cables reduce cable loosening during cycling. Both of these positive effects could decrease the risks related to grater trochanter non-union. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

  12. Discuss the cause and treatment of pacemaker lead dislocation and deal with

    International Nuclear Information System (INIS)

    Chen Yueguang; Zhang Dadong; Lu Jie; Yang Hui; Liu Chunyan; Zhang Wei

    2003-01-01

    Objective: To follow up the patients with pacemaker, observe the condition of pacemaker lead, to explore the cause of lead dislocation, to find out and prevent its occurrence. Methods: Summarizing the clinical data of 6 patients with pacemaker, 7 pacemaker leads with 8 time dislocation, pacemaker 2 DDDR, 2 DDD, 2 VVI. Results: Four patients were punctured from right subclavian vein, one from left subclavian vein and one from right brachiocephalic vein; four leads were dislocation in atrium and one mildly dislocation; four leads dislocation in ventricle and two mildly dislocation; There were 3 old women with 4 leads and 5 times of dislocation

  13. Removal of lead, mercury and nickel using the yeast Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Cherlys Infante J.

    2014-06-01

    Full Text Available Objective. In this study the biomass of the yeast Saccharomyces cerevisiae was used to remove lead, mercury and nickel in the form of ions dissolved in water. Materials and methods. Synthetic solutions were prepared containing the three heavy metals, which were put in contact with viable microorganisms at different conditions of pH, temperature, aeration and agitation. Results. Both individual variables and the interaction effects influenced the biosorption process. Throughout the experimental framework it was observed that the biomass of Saccharomyces cerevisiae removed a higher percentage of lead (86.4% as compared to mercury and nickel (69.7 and 47.8% respectively. When the pH was set at a value of 5 the effect was positive for all three metals. Conclusions. pH was the variable that had a greater influence on the biosorption of lead on the biomass of Saccharomyces cerevisiae. The affinity of the heavy metals for the biomass followed the order Pb>Hg>Ni.

  14. Does central bank communication really lead to better forecasts of policy decisions? New evidence based on a Taylor rule model for the ECB

    NARCIS (Netherlands)

    Sturm, Jan-Egbert; De Haan, Jakob

    Nowadays, it is widely believed that greater disclosure and clarity over policy may lead to greater predictability of central bank actions. We examine whether communication by the European Central Bank (ECB) adds information compared to the information provided by a Taylor rule model in which

  15. Treating Lead Toxicity: Possibilities beyond Synthetic Chelation

    Directory of Open Access Journals (Sweden)

    Shambhavi Tannir

    2013-01-01

    Full Text Available Lead, a ubiquitous metal, is one of the most abundant elements present on earth. Its easy availability and cost effectiveness made it an extremely popular component in the industrial revolution. However, its hazardous health effects were not considered at the time. Over the last few decades, with the adverse effects of lead coming to the forefront, nations across the world have started to recognize and treat lead toxicity. The most reliable and used method until now has been chelation therapy. Recent research has suggested the use of natural products and sources to treat lead poisoning with minimal or no side effects. This review has tried to summarize a few of the natural products/sources being investigated by various groups.

  16. Lead exposure in US worksites: A literature review and development of an occupational lead exposure database from the published literature

    Science.gov (United States)

    Koh, Dong-Hee; Locke, Sarah J.; Chen, Yu-Cheng; Purdue, Mark P.; Friesen, Melissa C.

    2016-01-01

    Background Retrospective exposure assessment of occupational lead exposure in population-based studies requires historical exposure information from many occupations and industries. Methods We reviewed published US exposure monitoring studies to identify lead exposure measurement data. We developed an occupational lead exposure database from the 175 identified papers containing 1,111 sets of lead concentration summary statistics (21% area air, 47% personal air, 32% blood). We also extracted ancillary exposure-related information, including job, industry, task/location, year collected, sampling strategy, control measures in place, and sampling and analytical methods. Results Measurements were published between 1940 and 2010 and represented 27 2-digit standardized industry classification codes. The majority of the measurements were related to lead-based paint work, joining or cutting metal using heat, primary and secondary metal manufacturing, and lead acid battery manufacturing. Conclusions This database can be used in future statistical analyses to characterize differences in lead exposure across time, jobs, and industries. PMID:25968240

  17. Modelling the emerging pollutant diclofenac with the GREAT-ER model: Application to the Llobregat River Basin

    International Nuclear Information System (INIS)

    Aldekoa, Joana; Medici, Chiara; Osorio, Victoria; Pérez, Sandra; Marcé, Rafael; Barceló, Damià; Francés, Félix

    2013-01-01

    Highlights: • Diclofenac levels were measured in 14 sampling sites of the Llobregat River (Spain). • GREAT-ER model was used to simulate diclofenac concentrations in the Llobregat River. • Deterministic and stochastic modelling approaches were contrasted. • Diclofenac discharge into the basin was estimated for the studied period. • Consistent degradation rates were predicted and compared with literature values. -- Abstract: The present research aims at giving an insight into the increasingly important issue of water pollution due to emerging contaminants. In particular, the source and fate of the non-steroidal anti-inflammatory drug diclofenac have been analyzed at catchment scale for the Llobregat River in Catalonia (Spain). In fact, water from the Llobregat River is used to supply a significant part of the Metropolitan Area of Barcelona. At the same time, 59 wastewater treatment plants discharge into this basin. GREAT-ER model has been implemented in this basin in order to reproduce a static balance for this pollutant for two field campaigns data set. The results highlighted the ability of GREAT-ER to simulate the diclofenac concentrations in the Llobregat Catchment; however, this study also pointed out the urgent need for longer time series of observed data and a better knowledge of wastewater plants outputs and their parameterization in order to obtain more reliable results

  18. Modelling the emerging pollutant diclofenac with the GREAT-ER model: Application to the Llobregat River Basin

    Energy Technology Data Exchange (ETDEWEB)

    Aldekoa, Joana, E-mail: joaalma2@cam.upv.es [Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia (Spain); Medici, Chiara [Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia (Spain); Osorio, Victoria; Pérez, Sandra [Institute of Environmental Assessment and Water Research, Jordi Girona 18-26, 08034 Barcelona (Spain); Marcé, Rafael [Catalan Institute for Water Research, Emili Grahit 101, 17003 Girona (Spain); Barceló, Damià [Institute of Environmental Assessment and Water Research, Jordi Girona 18-26, 08034 Barcelona (Spain); Francés, Félix [Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia (Spain)

    2013-12-15

    Highlights: • Diclofenac levels were measured in 14 sampling sites of the Llobregat River (Spain). • GREAT-ER model was used to simulate diclofenac concentrations in the Llobregat River. • Deterministic and stochastic modelling approaches were contrasted. • Diclofenac discharge into the basin was estimated for the studied period. • Consistent degradation rates were predicted and compared with literature values. -- Abstract: The present research aims at giving an insight into the increasingly important issue of water pollution due to emerging contaminants. In particular, the source and fate of the non-steroidal anti-inflammatory drug diclofenac have been analyzed at catchment scale for the Llobregat River in Catalonia (Spain). In fact, water from the Llobregat River is used to supply a significant part of the Metropolitan Area of Barcelona. At the same time, 59 wastewater treatment plants discharge into this basin. GREAT-ER model has been implemented in this basin in order to reproduce a static balance for this pollutant for two field campaigns data set. The results highlighted the ability of GREAT-ER to simulate the diclofenac concentrations in the Llobregat Catchment; however, this study also pointed out the urgent need for longer time series of observed data and a better knowledge of wastewater plants outputs and their parameterization in order to obtain more reliable results.

  19. Neurobehavioural effects of occupational exposure to lead.

    Science.gov (United States)

    Williamson, A M; Teo, R K

    1986-06-01

    A set of neurobehavioural tests selected on the basis of information processing theory was used to study the effect of low level occupational lead exposure on 59 lead workers compared with a matched control group of the same number. Only one of the lead exposed group had a blood lead concentration above the current threshold limit value of 3.81 mumol/l at the time of testing (mean 2.36 mumol/l, range 1.19-3.92 mumol/l) and none had been detected above that level in the previous three years. Nevertheless, most neurobehavioural functions tested showed some impairment in the lead workers. Visual sensory function was affected and, perhaps as a consequence, sustained attention and psychomotor tasks were performed more slowly by the lead exposed group. Cognitive functions were also impaired, with sensory store memory, short term memory, and learning abilities all showing deficits in lead workers. Such cognitive deficits may also be partly due to initial degradation of the visual input. Long term memory performance compared equally with control levels possibly because of development of a compensatory strategy such as rehearsal by the lead exposed subjects. Multiple linear regression analysis relating to lead workers test performance and their lead exposure showed that performance on the sensory store memory test alone was significantly related to exposure. This was probably due to the homogeneity of the lead exposed group with regard to blood lead concentrations and the use of blood lead as a measure of chronic lead exposure.

  20. Neurobehavioural effects of occupational exposure to lead

    Energy Technology Data Exchange (ETDEWEB)

    Williamson, A.M.; Teo, R.K.

    1986-06-01

    A set of neurobehavioural tests selected on the basis of information processing theory was used to study the effect of low level occupational lead exposure on 59 lead workers compared with a matched control group of the same number. Only one of the lead exposed group had a blood lead concentration above the current threshold limit value of 3.81 mumol/l at the time of testing (mean 2.36 mumol/l, range 1.19-3.92 mumol/l) and none had been detected above that level in the previous three years. Nevertheless, most neurobehavioural functions tested showed some impairment in the lead workers. Visual sensory function was affected and, perhaps as a consequence, sustained attention and psychomotor tasks were performed more slowly by the lead exposed group. Cognitive functions were also impaired, with sensory store memory, short term memory, and learning abilities all showing deficits in lead workers. Such cognitive deficits may also be partly due to initial degradation of the visual input. Long term memory performance compared equally with control levels possibly because of development of a compensatory strategy such as rehearsal by the lead exposed subjects. Multiple linear regression analysis relating to lead workers test performance and their lead exposure showed that performance on the sensory store memory test alone was significantly related to exposure. This was probably due to the homogeneity of the lead exposed group with regard to blood lead concentrations and the use of blood lead as a measure of chronic lead exposure.

  1. Off-line correction for excessive constant-fraction-discriminator walk in neutron time-of-flight experiments

    International Nuclear Information System (INIS)

    Heilbronn, Lawrence; Iwata, Yoshiyuki; Iwase, H.

    2003-01-01

    A method for reducing excessive constant-fraction-discriminator walk that utilizes experimental data in the off-line analysis stage is introduced. Excessive walk is defined here as any walk that leads to an overall timing resolution that is much greater than the intrinsic timing resolution of the detection system. The method is able to reduce the contribution to the overall timing resolution from the walk that is equal to or less than the intrinsic timing resolution of the detectors. Although the method is explained in the context of a neutron time-of-flight experiment, it is applicable to any data set that satisfies two conditions. (1) A measure of the signal amplitude for each event must be recorded on an event-by-event basis; and (2) There must be a distinguishable class of events present where the timing information is known a priori

  2. Recycling of spent lead/acid batteries. The case of Greece

    International Nuclear Information System (INIS)

    Zabaniotou, A.; Kouskoumvekaki, E.; Sanopoulos, D.

    1999-01-01

    In this study, the application of modern recycling technologies in accordance with the European and Greek legislation, aiming at the recovery of lead, polypropylene and sulfuric acid from spent lead (Pb)/acid batteries, is presented. The present state of their disposal and exploitation is also depicted. The international situation is reviewed, the general trends are marked and the main technologies related to lead/acid battery treatment are reported. General recommendations are given regarding the collection of spent batteries and the installation of a recycling plant in Greece. A sensitivity analysis is carried out in order to define the most significant parameters affecting the viability of a recycling scheme. The present study proves that a possible installation of a Pb/acid batteries recycling process unit, treating 17 000 t/year (estimated total quantity) and situated in the industrial area of the greater Athens region, seems to be economically profitable. The already existing operation of small-scale battery recycling plants, common in small countries, should be discouraged as they demonstrate a rather not environmentally acceptable recycling operation

  3. Reduction of lead pollution from vehicular emissions in cairo Part 1: Comparison of alternative solutions

    International Nuclear Information System (INIS)

    El-Haggar, S.M.; Saleh, S.K.; El-Kady, M.A.

    1996-01-01

    It has been recognized for decades that the major source of lead pollution is lead additives to automotive fuels. This problem has been countered in most countries in europe and Usa by introducing alternative anti-knock chemicals and unleaded gasoline. In egypt lead is still being added to gasoline in large quantities. However, progress has been made, and unleaded gasoline is currently being produced in Alexandria. Nevertheless, the major pollution problem remains in the Greater Cairo region as indicated by the atmospheric lead levels and the lead blood levels of the children in Cairo. The aim of the present study is to find an optimum solution to this problem. A comparison of the different solutions is conducted in order to come up with the most feasible solution to this urgent problem. In conclusion it has been demonstrated that the elimination of lead additives, with its huge positives effects on the country environment, proved to be profitable. 4 figs., 2 tabs

  4. THIOGLYCOLIC ACID ESTERIFIED IN TO RICE STRAW FOR REMOVING LEAD FROM AQUEOUS SOLUTION

    Directory of Open Access Journals (Sweden)

    R. Gong

    2011-09-01

    Full Text Available Thiol rice straw (TRS was prepared by esterifying thioglycolic acid onto rice straw in the medium of acetic anhydride and acetic acid with sulfuric acid as catalyst. The sorption of lead (Pb on TRS from aqueous solution was subsequently investigated. The batch experiments showed that Pb removal was dependent on initial pH, sorbent dose, Pb concentration, contact time, and temperature. The maximum value of Pb removal appeared at pH 5. For 100 mg/L of Pb solution, a removal ratio of greater than 98% could be achieved with 2.0 g/L or more of TRS. The isothermal data of Pb sorption conformed well to the Langmuir model, and the maximum sorption capacity (Qm of TRS for Pb was 104.17 mg/g. The equilibrium of Pb removal was reached within 120 min. The Pb removal process could be described by the pseudo-first-order kinetic model. The thermodynamic study indicated that the Pb removal process was spontaneous and endothermic.

  5. Galvanic Corrosion of Lead by Iron (Oxyhydr)Oxides: Potential Impacts on Drinking Water Quality.

    Science.gov (United States)

    Trueman, Benjamin F; Sweet, Gregory A; Harding, Matthew D; Estabrook, Hayden; Bishop, D Paul; Gagnon, Graham A

    2017-06-20

    Lead exposure via drinking water remains a significant public health risk; this study explored the potential effects of upstream iron corrosion on lead mobility in water distribution systems. Specifically, galvanic corrosion of lead by iron (oxyhydr)oxides was investigated. Coupling an iron mineral cathode with metallic lead in a galvanic cell increased lead release by 531 μg L -1 on average-a 9-fold increase over uniform corrosion in the absence of iron. Cathodes were composed of spark plasma sintered Fe 3 O 4 or α-Fe 2 O 3 or field-extracted Fe 3 O 4 and α-FeOOH. Orthophosphate immobilized oxidized lead as insoluble hydroxypyromorphite, while humic acid enhanced lead mobility. Addition of a humic isolate increased lead release due to uniform corrosion by 81 μg L -1 and-upon coupling lead to a mineral cathode-release due to galvanic corrosion by 990 μg L -1 . Elevated lead in the presence of humic acid appeared to be driven by complexation, with 208 Pb and UV 254 size-exclusion chromatograms exhibiting strong correlation under these conditions (R 2 average = 0.87). A significant iron corrosion effect was consistent with field data: lead levels after lead service line replacement were greater by factors of 2.3-4.7 at sites supplied by unlined cast iron distribution mains compared with the alternative, lined ductile iron.

  6. Cognitive disparities, lead plumbing, and water chemistry: prior exposure to water-borne lead and intelligence test scores among World War Two U.S. Army enlistees.

    Science.gov (United States)

    Ferrie, Joseph P; Rolf, Karen; Troesken, Werner

    2012-01-01

    Higher prior exposure to water-borne lead among male World War Two U.S. Army enlistees was associated with lower intelligence test scores. Exposure was proxied by urban residence and the water pH levels of the cities where enlistees lived in 1930. Army General Classification Test scores were six points lower (nearly 1/3 standard deviation) where pH was 6 (so the water lead concentration for a given amount of lead piping was higher) than where pH was 7 (so the concentration was lower). This difference rose with time exposed. At this time, the dangers of exposure to lead in water were not widely known and lead was ubiquitous in water systems, so these results are not likely the effect of individuals selecting into locations with different levels of exposure. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Developmental lead exposure has mixed effects on butterfly cognitive processes.

    Science.gov (United States)

    Philips, Kinsey H; Kobiela, Megan E; Snell-Rood, Emilie C

    2017-01-01

    While the effects of lead pollution have been well studied in vertebrates, it is unclear to what extent lead may negatively affect insect cognition. Lead pollution in soils can elevate lead in plant tissues, suggesting it could negatively affect neural development of insect herbivores. We used the cabbage white butterfly (Pieris rapae) as a model system to study the effect of lead pollution on insect cognitive processes, which play an important role in how insects locate and handle resources. Cabbage white butterfly larvae were reared on a 4-ppm lead diet, a concentration representative of vegetation in polluted sites; we measured eye size and performance on a foraging assay in adults. Relative to controls, lead-reared butterflies did not differ in time or ability to search for a food reward associated with a less preferred color. Indeed, lead-treated butterflies were more likely to participate in the behavioral assay itself. Lead exposure did not negatively affect survival or body size, and it actually sped up development time. The effects of lead on relative eye size varied with sex: lead tended to reduce eye size in males, but increase eye size in females. These results suggest that low levels of lead pollution may have mixed effects on butterfly vision, but only minimal impacts on performance in foraging tasks, although follow-up work is needed to test whether this result is specific to cabbage whites, which are often associated with disturbed areas.

  8. Effect of Chronic Lead Intoxication on Risky Behavior in Mice

    Directory of Open Access Journals (Sweden)

    L Mohammadyar

    2010-08-01

    Full Text Available Introduction: With industrialization of human societies, pollutants like lead have entered in the life cycle, causing harmful effects on body organs. No sufficient studies have been done on the effects of pollutants on behavior. The aim of this study was to investigate possible effects of lead on some measurable behaviors of an animal model. Methods: Forty eight male adult mice were divided into 4 groups of 12 each. Lead acetate was added at concentrations of 0, 5, 50, or 500 ppm to the drinking water of the animals for 4 weeks (28 days. On day 29, animals were placed on an Elevated Plus maze (EPM for 5 min and the time in sec spent was measured on closed arms, open arms and the end 1/3rd of the open arms. Increased time on open arms, particularly the end 1/3rd was considered to reflect an enhanced risk-accepting behavior. Results: In this study, it was shown that lead exposure caused an increased number of entrance (P=0.006 and time spent (P=0.034 by mice on open arms of the EPM. There was a positive correlation between the concentration of lead acetate and those two effects. Conclusion: The present study demonstrated that lead poisoning may decrease normal anxiety in mice and increase risky behavior in this species. Clinical studies on human subjects with risky behavior are strongly suggested in order to find a possible relation between chronic exposures to lead as well as plasma concentration of lead with the extent of this kind of behavior.

  9. Acute exposure to lead increases myocardial contractility independent of hypertension development

    Energy Technology Data Exchange (ETDEWEB)

    Fioresi, M. [Programa de Pós-Graduação em Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES (Brazil); Departamento de Enfermagem, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES (Brazil); Furieri, L.B.; Simões, M.R.; Ribeiro, R.F. Junior; Meira, E.F.; Fernandes, A.A.; Stefanon, I. [Programa de Pós-Graduação em Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES (Brazil); Vassallo, D.V. [Programa de Pós-Graduação em Ciências Fisiológicas, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, ES (Brazil); Centro de Ciências da Saúde de Vitória, Escola Superior de Ciências da Santa Casa de Misericórdia de Vitória, Vitória, ES (Brazil)

    2013-02-01

    We studied the effects of the acute administration of small doses of lead over time on hemodynamic parameters in anesthetized rats to determine if myocardial contractility changes are dependent or not on the development of hypertension. Male Wistar rats received 320 µg/kg lead acetate iv once, and their hemodynamic parameters were measured for 2 h. Cardiac contractility was evaluated in vitro using left ventricular papillary muscles as were Na{sup +},K{sup +}-ATPase and myosin Ca{sup 2+}-ATPase activities. Lead increased left- (control: 112 ± 3.7 vs lead: 129 ± 3.2 mmHg) and right-ventricular systolic pressures (control: 28 ± 1.2 vs lead: 34 ± 1.2 mmHg) significantly without modifying heart rate. Papillary muscles were exposed to 8 µM lead acetate and evaluated 60 min later. Isometric contractions increased (control: 0.546 ± 0.07 vs lead: 0.608 ± 0.06 g/mg) and time to peak tension decreased (control: 268 ± 13 vs lead: 227 ± 5.58 ms), but relaxation time was unchanged. Post-pause potentiation was similar between groups (n = 6 per group), suggesting no change in sarcoplasmic reticulum activity, evaluated indirectly by this protocol. After 1-h exposure to lead acetate, the papillary muscles became hyperactive in response to a β-adrenergic agonist (10 µM isoproterenol). In addition, post-rest contractions decreased, suggesting a reduction in sarcolemmal calcium influx. The heart samples treated with 8 µM lead acetate presented increased Na{sup +},K{sup +}-ATPase (approximately 140%, P < 0.05 for control vs lead) and myosin ATPase (approximately 30%, P < 0.05 for control vs lead) activity. Our results indicated that acute exposure to low lead concentrations produces direct positive inotropic and lusitropic effects on myocardial contractility and increases the right and left ventricular systolic pressure, thus potentially contributing to the early development of hypertension.

  10. Acute exposure to lead increases myocardial contractility independent of hypertension development

    International Nuclear Information System (INIS)

    Fioresi, M.; Furieri, L.B.; Simões, M.R.; Ribeiro, R.F. Junior; Meira, E.F.; Fernandes, A.A.; Stefanon, I.; Vassallo, D.V.

    2013-01-01

    We studied the effects of the acute administration of small doses of lead over time on hemodynamic parameters in anesthetized rats to determine if myocardial contractility changes are dependent or not on the development of hypertension. Male Wistar rats received 320 µg/kg lead acetate iv once, and their hemodynamic parameters were measured for 2 h. Cardiac contractility was evaluated in vitro using left ventricular papillary muscles as were Na + ,K + -ATPase and myosin Ca 2+ -ATPase activities. Lead increased left- (control: 112 ± 3.7 vs lead: 129 ± 3.2 mmHg) and right-ventricular systolic pressures (control: 28 ± 1.2 vs lead: 34 ± 1.2 mmHg) significantly without modifying heart rate. Papillary muscles were exposed to 8 µM lead acetate and evaluated 60 min later. Isometric contractions increased (control: 0.546 ± 0.07 vs lead: 0.608 ± 0.06 g/mg) and time to peak tension decreased (control: 268 ± 13 vs lead: 227 ± 5.58 ms), but relaxation time was unchanged. Post-pause potentiation was similar between groups (n = 6 per group), suggesting no change in sarcoplasmic reticulum activity, evaluated indirectly by this protocol. After 1-h exposure to lead acetate, the papillary muscles became hyperactive in response to a β-adrenergic agonist (10 µM isoproterenol). In addition, post-rest contractions decreased, suggesting a reduction in sarcolemmal calcium influx. The heart samples treated with 8 µM lead acetate presented increased Na + ,K + -ATPase (approximately 140%, P < 0.05 for control vs lead) and myosin ATPase (approximately 30%, P < 0.05 for control vs lead) activity. Our results indicated that acute exposure to low lead concentrations produces direct positive inotropic and lusitropic effects on myocardial contractility and increases the right and left ventricular systolic pressure, thus potentially contributing to the early development of hypertension

  11. Environmental Lead Pollution in an Urban Soft-water Area

    Science.gov (United States)

    Beattie, A. D.; Moore, M. R.; Devenay, W. T.; Miller, A. R.; Goldberg, A.

    1972-01-01

    An investigation has been reported on the clinical and metabolic effects of lead acquired by soft domestic water from lead plumbing systems in 23 Glasgow households. The lead content of water from cold taps was up to 18 times the upper acceptable limit and was proportional to the amount of lead in the plumbing system. The blood lead of 71 inhabitants of these houses showed a significant positive correlation with water lead content. Delta-aminolaevulic acid dehydrase activity, an extremely sensitive indicator of lead exposure, showed a significant negative correlation with water-lead content. Atmospheric lead was within acceptable limits in all but one house and no significant correlation could be found with biochemical measurements. A small number of clinical abnormalities were found but could not be directly attributed to lead toxicity. The results of the study underline the possible danger to health of lead plumbing systems in soft-water regions. PMID:5031207

  12. [Clinical Results of Endoscopic Treatment of Greater Trochanteric Pain Syndrome].

    Science.gov (United States)

    Zeman, P; Rafi, M; Skala, P; Zeman, J; Matějka, J; Pavelka, T

    2017-01-01

    PURPOSE OF THE STUDY This retrospective study aims to present short-term clinical outcomes of endoscopic treatment of patients with greater trochanteric pain syndrome (GTPS). MATERIAL AND METHODS The evaluated study population was composed of a total of 19 patients (16 women, 3 men) with the mean age of 47 years (19-63 years). In twelve cases the right hip joint was affected, in the remaining seven cases it was the left side. The retrospective evaluation was carried out only in patients with greater trochanteric pain syndrome caused by independent chronic trochanteric bursitis without the presence of m. gluteus medius tear not responding to at least 3 months of conservative treatment. In patients from the followed-up study population, endoscopic trochanteric bursectomy was performed alone or in combination with iliotibial band release. The clinical results were evaluated preoperatively and with a minimum follow-up period of 1 year after the surgery (mean 16 months). The Visual Analogue Scale (VAS) for assessment of pain and WOMAC (Western Ontario MacMaster) score were used. In both the evaluated criteria (VAS and WOMAC score) preoperative and postoperative results were compared. Moreover, duration of surgery and presence of postoperative complications were assessed. Statistical evaluation of clinical results was carried out by an independent statistician. In order to compare the parameter of WOMAC score and VAS pre- and post-operatively the Mann-Whitney Exact Test was used. The statistical significance was set at 0.05. RESULTS The preoperative VAS score ranged 5-9 (mean 7.6) and the postoperative VAS ranged 0-5 (mean 2.3). The WOMAC score ranged 56.3-69.7 (mean 64.2) preoperatively and 79.8-98.3 (mean 89.7) postoperatively. When both the evaluated parameters of VAS and WOMAC score were compared in time, a statistically significant improvement (ppain syndrome yields statistically significant improvement of clinical results with the concurrent minimum incidence of

  13. Association of blood lead levels in children 0-72 months with living in Mid-Appalachia: a semi-ecologic study.

    Science.gov (United States)

    Wiener, R Constance; Jurevic, Richard J

    2016-01-01

    Lead exposure in children remains a significant public health issue, although many advances have been made. The Mid-Appalachia area (Kentucky, New York, Ohio, Pennsylvania, and West Virginia) is 89-91% rural with a population density of 16-21 people/km2 (41-54 people/mi2). Mid-Appalachia has significant health disparities including concerns for the consequences of greater lead exposure to children due to mining and industrial footprints, and existing older housing. The purpose of this study is to compare the reported blood lead levels of screened children, aged 0-72 months in Mid-Appalachia, to the children in the USA in general. Data from the Centers for Disease Control and Prevention and from the US Census Bureau were analyzed in a semi-ecological study. The blood lead level of 5 μg/dL was compared between children in Mid-Appalachia and the US housing units built before 1950; US housing units built before 1940 were also compared. The number of children with blood lead levels of 5 μg/dL was significantly greater in Mid-Appalachia than nationally (7.75% vs 5.79%, respectively; pecological relationship with the number of homes built before 1950 and before 1940.

  14. Stress and Subjective Age: Those With Greater Financial Stress Look Older.

    Science.gov (United States)

    Agrigoroaei, Stefan; Lee-Attardo, Angela; Lachman, Margie E

    2017-12-01

    Subjective indicators of age add to our understanding of the aging process beyond the role of chronological age. We examined whether financial stress contributes to subjective age as rated by others and the self. The participants ( N = 228), aged 26-75, were from a Boston area satellite of the Midlife in the United States (MIDUS) longitudinal study. Participants reported how old they felt and how old they thought they looked, and observers assessed the participants' age based on photographs (other-look age), at two occasions, an average of 10 years apart. Financial stress was measured at Time 1. Controlling for income, general stress, health, and attractiveness, participants who reported higher levels of financial stress were perceived as older than their actual age to a greater extent and showed larger increases in other-look age over time. We consider the results on accelerated aging of appearance with regard to their implications for interpersonal interactions and in relation to health.

  15. The influence of declining air lead levels on blood lead-air lead slope factors in children.

    Science.gov (United States)

    Richmond-Bryant, Jennifer; Meng, Qingyu; Davis, Allen; Cohen, Jonathan; Lu, Shou-En; Svendsgaard, David; Brown, James S; Tuttle, Lauren; Hubbard, Heidi; Rice, Joann; Kirrane, Ellen; Vinikoor-Imler, Lisa C; Kotchmar, Dennis; Hines, Erin P; Ross, Mary

    2014-07-01

    It is difficult to discern the proportion of blood lead (PbB) attributable to ambient air lead (PbA), given the multitude of lead (Pb) sources and pathways of exposure. The PbB-PbA relationship has previously been evaluated across populations. This relationship was a central consideration in the 2008 review of the Pb national ambient air quality standards. The objectives of this study were to evaluate the relationship between PbB and PbA concentrations among children nationwide for recent years and to compare the relationship with those obtained from other studies in the literature. We merged participant-level data for PbB from the National Health and Nutrition Examination Survey (NHANES) III (1988-1994) and NHANES 9908 (1999-2008) with PbA data from the U.S. Environmental Protection Agency. We applied mixed-effects models, and we computed slope factor, d[PbB]/d[PbA] or the change in PbB per unit change in PbA, from the model results to assess the relationship between PbB and PbA. Comparing the NHANES regression results with those from the literature shows that slope factor increased with decreasing PbA among children 0-11 years of age. These findings suggest that a larger relative public health benefit may be derived among children from decreases in PbA at low PbA exposures. Simultaneous declines in Pb from other sources, changes in PbA sampling uncertainties over time largely related to changes in the size distribution of Pb-bearing particulate matter, and limitations regarding sampling size and exposure error may contribute to the variability in slope factor observed across peer-reviewed studies.

  16. Do new wipe materials outperform traditional lead dust cleaning methods?

    Science.gov (United States)

    Lewis, Roger D; Ong, Kee Hean; Emo, Brett; Kennedy, Jason; Brown, Christopher A; Condoor, Sridhar; Thummalakunta, Laxmi

    2012-01-01

    Government guidelines have traditionally recommended the use of wet mopping, sponging, or vacuuming for removal of lead-contaminated dust from hard surfaces in homes. The emergence of new technologies, such as the electrostatic dry cloth and wet disposable clothes used on mopheads, for removal of dust provides an opportunity to evaluate their ability to remove lead compared with more established methods. The purpose of this study was to determine if relative differences exist between two new and two older methods for removal of lead-contaminated dust (LCD) from three wood surfaces that were characterized by different roughness or texture. Standard leaded dust, coefficient of friction was performed for each wipe material. Analysis of variance was used to evaluate the surface and cleaning methods. There were significant interactions between cleaning method and surface types, p = 0.007. Cleaning method was found be a significant factor in removal of lead, p coefficient of friction, significantly different among the three wipes, is likely to influence the cleaning action. Cleaning method appears to be more important than texture in LCD removal from hard surfaces. There are some small but important factors in cleaning LCD from hard surfaces, including the limits of a Swiffer mop to conform to curved surfaces and the efficiency of the wetted shop towel and vacuuming for cleaning all surface textures. The mean percentage reduction in lead dust achieved by the traditional methods (vacuuming and wet wiping) was greater and more consistent compared to the new methods (electrostatic dry cloth and wet Swiffer mop). Vacuuming and wet wiping achieved lead reductions of 92% ± 4% and 91%, ± 4%, respectively, while the electrostatic dry cloth and wet Swiffer mops achieved lead reductions of only 89 ± 8% and  81 ± 17%, respectively.

  17. GREATER OMENTUM: MORPHOFUNCTIONAL CHARACTERISTICS AND CLINICAL SIGNIFICANCE IN PEDIATRICS

    Directory of Open Access Journals (Sweden)

    A.V. Nekrutov

    2007-01-01

    Full Text Available The review analyzes the structure organization and pathophysiological age specificities of the greater omentum, which determine its uniqueness and functional diversity in a child's organism. the article discusses protective functions of the organ, its role in the development of post operative complications of children, and the usage in children's reconstructive plastic surgery.Key words: greater omentum, omentitis, of post operative complications, children.

  18. Verification of radiation exposure using lead shields

    International Nuclear Information System (INIS)

    Hayashida, Keiichi; Yamamoto, Kenyu; Azuma, Masami

    2016-01-01

    A long time use of radiation during IVR (intervention radiology) treatment leads up to an increased exposure on IVR operator. In order to prepare good environment for the operator to work without worry about exposure, the authors examined exposure reduction with the shields attached to the angiography instrument, i. e. lead curtain and lead glass. In this study, the lumber spine phantom was radiated using the instrument and the radiation leaked outside with and without shields was measured by the ionization chamber type survey meter. The meter was placed at the position which was considered to be that for IVR operator, and changed vertically 20-100 cm above X-ray focus by 10 cm interval. The radiation at the position of 80 cm above X-ray focus was maximum without shield and was hardly reduced with lead curtain. However, it was reduced with lead curtain plus lead glass. Similar reduction effects were observed at the position of 90-100 cm above X-ray focus. On the other hand, the radiation at the position of 70 cm above X-ray focus was not reduced with either shield, because that position corresponded to the gap between lead curtain and lead glass. The radiation at the position of 20-60 cm above X-ray focus was reduced with lead curtain, even if without lead glass. These results show that lead curtain and lead glass attached to the instrument can reduce the radiation exposure on IVR operator. Using these shields is considered to be one of good means for IVR operator to work safely. (author)

  19. Greater Trochanteric Pain Syndrome: Percutaneous Tendon Fenestration Versus Platelet-Rich Plasma Injection for Treatment of Gluteal Tendinosis.

    Science.gov (United States)

    Jacobson, Jon A; Yablon, Corrie M; Henning, P Troy; Kazmers, Irene S; Urquhart, Andrew; Hallstrom, Brian; Bedi, Asheesh; Parameswaran, Aishwarya

    2016-11-01

    The purpose of this study was to compare ultrasound-guided percutaneous tendon fenestration to platelet-rich plasma (PRP) injection for treatment of greater trochanteric pain syndrome. After Institutional Review Board approval was obtained, patients with symptoms of greater trochanteric pain syndrome and ultrasound findings of gluteal tendinosis or a partial tear (Pain scores were recorded at baseline, week 1, and week 2 after treatment. Retrospective clinic record review assessed patient symptoms. The study group consisted of 30 patients (24 female), of whom 50% were treated with fenestration and 50% were treated with PRP. The gluteus medius was treated in 73% and 67% in the fenestration and PRP groups, respectively. Tendinosis was present in all patients. In the fenestration group, mean pain scores were 32.4 at baseline, 16.8 at time point 1, and 15.2 at time point 2. In the PRP group, mean pain scores were 31.4 at baseline, 25.5 at time point 1, and 19.4 at time point 2. Retrospective follow-up showed significant pain score improvement from baseline to time points 1 and 2 (P.99). Our study shows that both ultrasound-guided tendon fenestration and PRP injection are effective for treatment of gluteal tendinosis, showing symptom improvement in both treatment groups. © 2016 by the American Institute of Ultrasound in Medicine.

  20. More features, greater connectivity.

    Science.gov (United States)

    Hunt, Sarah

    2015-09-01

    Changes in our political infrastructure, the continuing frailties of our economy, and a stark growth in population, have greatly impacted upon the perceived stability of the NHS. Healthcare teams have had to adapt to these changes, and so too have the technologies upon which they rely to deliver first-class patient care. Here Sarah Hunt, marketing co-ordinator at Aid Call, assesses how the changing healthcare environment has affected one of its fundamental technologies - the nurse call system, argues the case for wireless such systems in terms of what the company claims is greater adaptability to changing needs, and considers the ever-wider range of features and functions available from today's nurse call equipment, particularly via connectivity with both mobile devices, and ancillaries ranging from enuresis sensors to staff attack alert 'badges'.

  1. Aging of residual surface resistance of superconducting lead cavities

    DEFF Research Database (Denmark)

    Danielsen, M.

    1972-01-01

    Measurements of the residual surface resistance of superconducting lead cavities as a function of time during a period of a month showed an oscillating variation. An explanation of the ageing curves is proposed. ©1972 The American Institute of Physics......Measurements of the residual surface resistance of superconducting lead cavities as a function of time during a period of a month showed an oscillating variation. An explanation of the ageing curves is proposed. ©1972 The American Institute of Physics...

  2. Kape barako (coffea liberica) grounds as adsorbent for the removal of lead in lead-enriched Marikina river water samples

    International Nuclear Information System (INIS)

    Valera, Florenda S.; Garcia, Jhonard John L.

    2015-01-01

    Kape Barako (Coffee liberica) grounds (residue left after brewing ground coffee) were used as adsorbent for the removal of lead in Marikina River water samples. The sundried coffee grounds showed 9.30% moisture after drying in the oven. The coffee grounds were determined using Shimadzu AA-6501S Atomic Adsorption Spectrometer. The lead concentration was determined to be 4.7 mg/kg in coffee grounds and below detection limit in the Marikina River water samples. The adsorption studies were done at room temperature, and the optimized parameters were a contact time of 3 hours, an adsorbent dose of 3.0 g/L and 4.0 mg/L Pb-enriched water samples. The maximum uptake capacity was found to be 14.2 mg of lead/g adsorbent. The adsorption studies were done at room temperature, and the optimized parameters were a contact time of 3 hours, an adsorbent dose of 3.0 g/L and 4.0 mg/L Pb-enriched water samples. Analyses of the coffee grounds before and after lead adsorption using Shimadzu IR-Affinity-I Fourier Transform Infrared Spectrometer showed marked difference in the spectra, indicating interaction between Pb and the functional groups of the coffee grounds. (author)

  3. Evaluation of Integrated Time-Temperature Effect in Pyrolysis Process of Historically Contaminated Soils with Cadmium (Cd and Lead (Pb

    Directory of Open Access Journals (Sweden)

    Bulmău C

    2013-04-01

    Full Text Available It is already known that heavy metals pollution causes important concern to human and ecosystem health. Heavy metals in soils at the European level represents 37.3% between main contaminates affecting soils (EEA, 2007. This paper illustrates results obtained in the framework of laboratory experiments concerning the evaluation of integrated time-temperature effect in pyrolysis process applied to contaminated soil by two different ways: it is about heavy metals historically contaminated soil from one of the most polluted areas within Romania, and artificially contaminated with PCB-containing transformer oil. In particular, the authors focused on a recent evaluation of pyrolysis efficiency on removing lead (Pb and cadmium (Cd from the contaminated soil. The experimental study evaluated two important parameters related to the studied remediation methodology: thermal process temperature and the retention time in reactor of the contaminated soils. The remediation treatments were performed in a rotary kiln reactor, taking into account three process temperatures (400°C, 600°C and 800°C and two retention times: 30 min. and 60 min. Completed analyses have focused on pyrolysis solids and gas products. Consequently, both ash and gas obtained after pyrolysis process were subjected to chemical analyses.

  4. Leading proton production in deep inelastic scattering at HERA

    International Nuclear Information System (INIS)

    Chekanov, S.; Derrick, M.; Magill, S.

    2008-12-01

    The semi-inclusive reaction e + p→e + Xp was studied with the ZEUS detector at HERA using an integrated luminosity of 12.8 pb -1 . The final-state proton, which was detected with the ZEUS leading proton spectrometer, carried a large fraction of the incoming proton energy, x L >0.32, and its transverse momentum squared satisfied p T 2 2 ; the exchanged photon virtuality, Q 2 , was greater than 3 GeV 2 and the range of the masses of the photon-proton system was 45 L , p T 2 , Q 2 and the Bjorken scaling variable, x. (orig.)

  5. The Greater Caucasus Glacier Inventory (Russia, Georgia and Azerbaijan)

    Science.gov (United States)

    Tielidze, Levan G.; Wheate, Roger D.

    2018-01-01

    There have been numerous studies of glaciers in the Greater Caucasus, but none that have generated a modern glacier database across the whole mountain range. Here, we present an updated and expanded glacier inventory at three time periods (1960, 1986, 2014) covering the entire Greater Caucasus. Large-scale topographic maps and satellite imagery (Corona, Landsat 5, Landsat 8 and ASTER) were used to conduct a remote-sensing survey of glacier change, and the 30 m resolution Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model (ASTER GDEM; 17 November 2011) was used to determine the aspect, slope and height distribution of glaciers. Glacier margins were mapped manually and reveal that in 1960 the mountains contained 2349 glaciers with a total glacier surface area of 1674.9 ± 70.4 km2. By 1986, glacier surface area had decreased to 1482.1 ± 64.4 km2 (2209 glaciers), and by 2014 to 1193.2 ± 54.0 km2 (2020 glaciers). This represents a 28.8 ± 4.4 % (481 ± 21.2 km2) or 0.53 % yr-1 reduction in total glacier surface area between 1960 and 2014 and an increase in the rate of area loss since 1986 (0.69 % yr-1) compared to 1960-1986 (0.44 % yr-1). Glacier mean size decreased from 0.70 km2 in 1960 to 0.66 km2 in 1986 and to 0.57 km2 in 2014. This new glacier inventory has been submitted to the Global Land Ice Measurements from Space (GLIMS) database and can be used as a basis data set for future studies.

  6. Inventory Modelling for a Manufacturer of Sweets : An Evaluation of an Adjusted Compund Renewal Approach for B-Items With A Relative Short Production Lead Time

    NARCIS (Netherlands)

    Heuts, R.M.J.; Luijten, M.L.J.

    1999-01-01

    In this paper we are especially interested how to optimize the production/inventory control for a manufacturer of sweets, under the following circumstances: short production lead times in combination with an intermittent demand pattern for the so-called B-taste items. As for A-taste items a compound

  7. The effect of illegal lead processing on blood lead levels in children living in the mining area

    Directory of Open Access Journals (Sweden)

    Ćorac Aleksandar

    2017-01-01

    Full Text Available Backgraund/Aim. The northern part of Kosovo was one of the largest lead and zinc production industries in Europe. Special attention has been paid to the landfill sites of these metals remained after past industrial activities. The inhabitants of Roma camps in this area are collecting led waste they process by crushing and melting in their shacks in primitively organized working environments. Because of all the aforementioned it was necessary to examine the concentration of blood lead level (BLL in the children aged less than 6 years inhabiting this area, especially taking care of blood analysis of children living in Roma camps. Methods. The study was conducted in the municipality of Leposavić, Province Kosovo and Metohija, Serbia. Totally 78 subjects participated in the study. All the subjects were divided into two groups: the group I consisting of 42 children who lived in the Romas camp, and the group II with 36 children from a city kindergarten. Based on the mathematical model WRPLOT we found out that both groups of patients were in the low risk zone for industrial contamination exposure. Blood analysis was done according to the protocol provided by ESA Lead Care. Results. The average age of participants in the study was 4.60 ± 1.63 years. The mean BBL in the children from the group 1 was 19.11 μg/dL and from the group 2 4.87 μg/dL. There was a statistically significant difference in the mean values of BBL between the groups (U = 39, p < 0.001. All of the children from the group 1 had BBL greater than 5 μg/dL in comparison to 38.9% of the children from the group 2 (χ2 = 35.75, p < 0.001. Conclusion. Although both groups were located outside the zone of direct spread of pollution, the results indicate high concentrations of lead in blood of all the examined children. The concentration was higher in the children who lived in the area in which illegal processing of lead waste took place. [Project of the Serbian Ministry of Education

  8. Removal of lead from crude antimony by using NaPo3 as lead elimination reagent

    Directory of Open Access Journals (Sweden)

    Ye L.G.

    2015-01-01

    Full Text Available In order to solve the shortcomings when removing lead from crude antimony in the traditional antimony smelting, a new process was provided using NaPO3 as lead elimination reagent to yield phosphate slag, and it was removed by floating on the surface of the liquid antimony. Reaction mechanism was clarified by using the TG-DTA and XRD techniques and single factor experiments of removal lead from crude antimony were engaged. The results show that PbO and NaPO3 begin endothermic reaction at 863K (590°C, and the reaction mainly form NaPb4(PO43 and NaPbPO4 below 1123K (850°C and above 1123K (850°C, respectively. Sb2O3 and NaPO3 start the reaction at 773K (500°C and generate an antimonic salt compound. The reaction product of the mixture of PbO, Sb2O3 and NaPO3 show that NaPO3 reacted with PbO prior when NaPO3 was insufficient, amorphous antimony glass will be generated only when NaPO3 was adequate. Single factor experiments were taken with NaNO3 as oxidizing agent under argon, effect of reaction time, reaction temperature and dosage of NaPO3 and NaNO3 on smelting results. The average content of lead in refined antimony was 0.05340% and 98.85% of lead were removed under optimal conditions; the content of lead in antimony have meet the requirements of commercial antimony.

  9. Greater Sudbury fuel efficient driving handbook

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-12-15

    Reducing the amount of fuel that people use for personal driving saves money, improves local air quality, and reduces personal contributions to climate change. This handbook was developed to be used as a tool for a fuel efficient driving pilot program in Greater Sudbury in 2009-2010. Specifically, the purpose of the handbook was to provide greater Sudbury drivers with information on how to drive and maintain their personal vehicles in order to maximize fuel efficiency. The handbook also provides tips for purchasing fuel efficient vehicles. It outlines the benefits of fuel maximization, with particular reference to reducing contributions to climate change; reducing emissions of air pollutants; safe driving; and money savings. Some tips for efficient driving are to avoid aggressive driving; use cruise control; plan trips; and remove excess weight. Tips for efficient winter driving are to avoid idling to warm up the engine; use a block heater; remove snow and ice; use snow tires; and check tire pressure. The importance of car maintenance and tire pressure was emphasized. The handbook also explains how fuel consumption ratings are developed by vehicle manufacturers. refs., figs.

  10. Supply Chain Management for Sustainable Development: Perspective from the Greater Pearl River Delta (China)

    OpenAIRE

    Tsoi, Joyce

    2006-01-01

    This thesis was submitted for the degree of Doctor of Philosophy and awarded by the University of Hong Kong. This thesis investigates the application and implications of supply chain management as a modern management model in regulating corporate outsourcing activities within the Greater Pearl River Delta. Globalisation has accelerated the application of supply chain management as a mechanism to enhance corporate performance. At the same time this rapid economic development has also accele...

  11. SU-E-P-09: Radiation Transmission Measurements and Evaluation of Diagnostic Lead-Based and Lead-Free Aprons

    Energy Technology Data Exchange (ETDEWEB)

    Syh, J [Willis-Knighton Medical Center, Shreveport, LA (United States)

    2014-06-01

    Purpose: This study was conducted to ensure that various lead shield apron manufacturers provided accurate attenuation factors regardless of whether the apron was made of lead-based or lead-free equivalent material. Methods: A calibrated ionization survey meter was placed at chest height and 36 cm horizontally away from a solid water phantom on a simulator couch. Measurements were done with or without apron. Radiation field was set to 24cmx24cm with the phantom at 100cm source-to-surface distance. Irradiation time was set for 1 minute at voltages of 60, 80, 100 and 120 kVp. Current was set at 6mA. Results: Between 60 kVp and 120 kVp, the transmission through 0.50 mm of lead-based apron was between 1.0% and 6.5% with a mean value of 3.2% and a standard deviation (s.d.) of 1.4%. The transmissions through the 0.50 mm lead-free aprons were 1.0 % to 12.0% with a mean value of 6.1% and s.d. of 2.6%. At 120 kVp, the transmission value was 6.5% for 0.50 mm lead-based apron and 11.1% to 12.0% for 0.50 mm lead-free aprons. The radiation transmissions at 80 kVp, measured in two different 0.5 mm lead-free aprons, were 4.3% each. However, only 1.4% transmission was found through the lead-based apron. Overall, the radiation transmitted through the lead-based apron was 1/3 transmission of lead-free at 80kVp, and half value of lead-free aprons at 100 and 120 kVp. Conclusion: Even though lead-based and lead-free aprons all claimed to have the same lead equivalent thickness, the transmission might not be the same. The precaution was needed to exercise diligence in quality assurance program to assure adequate protection to staff who wear it during diagnostic procedures. The requirement for aprons not only should be in certain thickness to meet state regulation but also to keep reasonably achievable low exposure with the accurate labeling from manufacturers.

  12. SU-E-P-09: Radiation Transmission Measurements and Evaluation of Diagnostic Lead-Based and Lead-Free Aprons

    International Nuclear Information System (INIS)

    Syh, J

    2014-01-01

    Purpose: This study was conducted to ensure that various lead shield apron manufacturers provided accurate attenuation factors regardless of whether the apron was made of lead-based or lead-free equivalent material. Methods: A calibrated ionization survey meter was placed at chest height and 36 cm horizontally away from a solid water phantom on a simulator couch. Measurements were done with or without apron. Radiation field was set to 24cmx24cm with the phantom at 100cm source-to-surface distance. Irradiation time was set for 1 minute at voltages of 60, 80, 100 and 120 kVp. Current was set at 6mA. Results: Between 60 kVp and 120 kVp, the transmission through 0.50 mm of lead-based apron was between 1.0% and 6.5% with a mean value of 3.2% and a standard deviation (s.d.) of 1.4%. The transmissions through the 0.50 mm lead-free aprons were 1.0 % to 12.0% with a mean value of 6.1% and s.d. of 2.6%. At 120 kVp, the transmission value was 6.5% for 0.50 mm lead-based apron and 11.1% to 12.0% for 0.50 mm lead-free aprons. The radiation transmissions at 80 kVp, measured in two different 0.5 mm lead-free aprons, were 4.3% each. However, only 1.4% transmission was found through the lead-based apron. Overall, the radiation transmitted through the lead-based apron was 1/3 transmission of lead-free at 80kVp, and half value of lead-free aprons at 100 and 120 kVp. Conclusion: Even though lead-based and lead-free aprons all claimed to have the same lead equivalent thickness, the transmission might not be the same. The precaution was needed to exercise diligence in quality assurance program to assure adequate protection to staff who wear it during diagnostic procedures. The requirement for aprons not only should be in certain thickness to meet state regulation but also to keep reasonably achievable low exposure with the accurate labeling from manufacturers

  13. Engaging narratives evoke similar neural activity and lead to similar time perception.

    Science.gov (United States)

    Cohen, Samantha S; Henin, Simon; Parra, Lucas C

    2017-07-04

    It is said that we lose track of time - that "time flies" - when we are engrossed in a story. How does engagement with the story cause this distorted perception of time, and what are its neural correlates? People commit both time and attentional resources to an engaging stimulus. For narrative videos, attentional engagement can be represented as the level of similarity between the electroencephalographic responses of different viewers. Here we show that this measure of neural engagement predicted the duration of time that viewers were willing to commit to narrative videos. Contrary to popular wisdom, engagement did not distort the average perception of time duration. Rather, more similar brain responses resulted in a more uniform perception of time across viewers. These findings suggest that by capturing the attention of an audience, narrative videos bring both neural processing and the subjective perception of time into synchrony.

  14. Greater Vancouver regional district air quality management plan : implementation status report

    International Nuclear Information System (INIS)

    2001-03-01

    In December 1994, an Air Quality Management Plan (AQMP) was adopted by the Greater Vancouver Regional District. The AQMP included ways to improve air quality in the region, leading to reduced emissions from commercial and industrial operations. This Plan encourages cooperation with the various communities affected to achieve clean air lifestyles and manage emissions from human activity to enhance human health and the integrity of the environment. The reduction of total emissions of the common air contaminants sulphur and nitrogen oxides, particulate matter, carbon monoxide and volatile organic compounds by 38 per cent is the stated aim of the AQMP. Five years of planning resulted in the formulation of the AQMP. The issues addressed were assigned one of four priorities as follows: priority 1 deals with ground level ozone and fine particulate, priority 2 looks at visibility, hazardous air pollutants, and global climate change, priority 3 concerns odour, carbon monoxide, sulphur dioxide, acidic deposition, and nitrogen dioxide, and priority 4 contains total suspended particulate matter and volatile organic compounds. A total of 54 Emission Reduction Measures were established, and the document reviewed them. Progress is being made in all areas. 2 tabs., 3 figs

  15. Anthropogenic impact and lead pollution throughout the Holocene in Southern Iberia.

    Science.gov (United States)

    García-Alix, A; Jimenez-Espejo, F J; Lozano, J A; Jiménez-Moreno, G; Martinez-Ruiz, F; García Sanjuán, L; Aranda Jiménez, G; García Alfonso, E; Ruiz-Puertas, G; Anderson, R Scott

    2013-04-01

    Present day lead pollution is an environmental hazard of global proportions. A correct determination of natural lead levels is very important in order to evaluate anthropogenic lead contributions. In this paper, the anthropogenic signature of early metallurgy in Southern Iberia during the Holocene, more specifically during the Late Prehistory, was assessed by mean of a multiproxy approach: comparison of atmospheric lead pollution, fire regimes, deforestation, mass sediment transport, and archeological data. Although the onset of metallurgy in Southern Iberia is a matter of controversy, here we show the oldest lead pollution record from Western Europe in a continuous paleoenvironmental sequence, which suggests clear lead pollution caused by metallurgical activities since ~3900 cal BP (Early Bronze Age). This lead pollution was especially important during Late Bronze and Early Iron ages. At the same time, since ~4000 cal BP, an increase in fire activity is observed in this area, which is also coupled with deforestation and increased erosion rates. This study also shows that the lead pollution record locally reached near present-day values many times in the past, suggesting intensive use and manipulation of lead during those periods in this area. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Cyclists Have Greater Chondromalacia Index Than Age-Matched Controls at the Time of Hip Arthroscopy.

    Science.gov (United States)

    Stone, Austin V; Howse, Elizabeth A; Mannava, Sandeep; Stubbs, Allston J

    2016-10-01

    To evaluate the clinical symptoms and intraoperative pathology associated with hip pain in the cyclist compared with a matched hip arthroscopy surgical group. In an institutional review board-approved study, we retrospectively reviewed a prospective database of 1,200 consecutive hip arthroscopy patients from 2008 to 2015. Adult patients were identified who reported cycling as a major component of their activity. Patients were age, gender, and body mass index matched to a control, noncycling group. Pain symptoms, preoperative examinations, radiographic and operative findings were compared. Primary outcome variables included the femoral and acetabular Outerbridge chondromalacia grade. Additional outcome measurements included the involved area and the chondromalacia index (CMI; the product of the Outerbridge chondromalacia grade and surface area [mm 2  × severity]). A total of 167 noncyclists were matched to the cycling group (n = 16). Cyclists had significantly greater femoral head chondromalacia grade (2.0 [95% confidence interval (CI), 1.5-2.5] v 1.4 [95% CI, 1.3-1.6], P = .043), femoral head chondromalacia area (242 mm 2 [95% CI, 191-293 mm 2 ] v 128 mm 2 [95% CI, 113-141 mm 2 ], P chondromalacia than a matched group of noncyclists. Cycling activity positively correlated with the presence of femoral chondromalacia with clinically significant gait alterations. These data support the hypothesis that cyclists with hip pain have more chondral pathology than a similar group of other patients with hip pain. Ultimately, cyclists with hip pain should be identified as higher risk for more advanced chondral damage. Level III, case-control study, therapeutic. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  17. Comparison of Sprint Fidelis and Riata defibrillator lead failure rates.

    Science.gov (United States)

    Fazal, Iftikhar A; Shepherd, Ewen J; Tynan, Margaret; Plummer, Christopher J; McComb, Janet M

    2013-09-30

    Sprint Fidelis and Riata defibrillator leads are prone to early failure. Few data exist on the comparative failure rates and mortality related to lead failure. The aims of this study were to determine the failure rate of Sprint Fidelis and Riata leads, and to compare failure rates and mortality rates in both groups. Patients implanted with Sprint Fidelis leads and Riata leads at a single centre were identified and in July 2012, records were reviewed to ascertain lead failures, deaths, and relationship to device/lead problems. 113 patients had Sprint Fidelis leads implanted between June 2005 and September 2007; Riata leads were implanted in 106 patients between January 2003 and February 2008. During 53.0 ± 22.3 months of follow-up there were 13 Sprint Fidelis lead failures (11.5%, 2.60% per year) and 25 deaths. Mean time to failure was 45.1 ± 15.5 months. In the Riata lead cohort there were 32 deaths, and 13 lead failures (11.3%, 2.71% per year) over 54.8 ± 26.3 months follow-up with a mean time to failure of 53.5 ± 24.5 months. There were no significant differences in the lead failure-free Kaplan-Meier survival curve (p=0.77), deaths overall (p=0.17), or deaths categorised as sudden/cause unknown (p=0.54). Sprint Fidelis and Riata leads have a significant but comparable failure rate at 2.60% per year and 2.71% per year of follow-up respectively. The number of deaths in both groups is similar and no deaths have been identified as being related to lead failure in either cohort. Copyright © 2012. Published by Elsevier Ireland Ltd.

  18. Effect of in vitro inorganic lead on dopamine release from superfused rat striatal synaptosomes

    International Nuclear Information System (INIS)

    Minnema, D.J.; Greenland, R.D.; Michaelson, I.A.

    1986-01-01

    The effect of inorganic lead in vitro in several aspects of [ 3 H]dopamine release from superfused rat striatal synaptosomes was examined. Under conditions of spontaneous release, lead (1-30 microM) induced dopamine release in a concentration-dependent manner. The onset of the lead-induced release was delayed by approximately 15-30 sec. The magnitude of dopamine release induced by lead was increased when calcium was removed from the superfusing buffer. Lead-induced release was unaffected in the presence of putative calcium, sodium, and/or potassium channel blockers (nickel, tetrodotoxin, tetraethylammonium, respectively). Depolarization-evoked dopamine release, produced by a 1-sec exposure to 61 mM potassium, was diminished at calcium concentrations below 0.254 mM. The onset of depolarization-evoked release was essentially immediate following exposure of the synaptosomes to high potassium. The combination of lead (3 or 10 microM) with high potassium reduced the magnitude of depolarization-evoked dopamine release. This depression of depolarization-evoked release by lead was greater in the presence of 0.25 mM than 2.54 mM calcium in the superfusing buffer. These findings demonstrate multiple actions of lead on synaptosomal dopamine release. Lead can induce dopamine release by yet unidentified neuronal mechanisms independent of external calcium. Lead can also reduce depolarization-evoked dopamine release by apparent competition with calcium influx at the neuronal membrane calcium channel

  19. Animals afflicted with lead poisoning from motor exhaust

    Energy Technology Data Exchange (ETDEWEB)

    Scheel-Thomsen, A

    1956-01-01

    Three cases of dogs treated for ulcerous conditions of the oral cavity and a trembling of the limbs, which were eventually discovered to be lead poisoning derived from constant exposure to gasoline and automotive exhaust, are reported. The first case, typical of all three, was first treated in April 1951. The lesions healed after a stay in the hospital but recurred after he returned home. The dog was also asymptomatic when at the owner's summer home for any length of time. It was discovered that at his winter home the dog spent much of his time around a large automobile garage. After treatment with Antoxol (dimercaprol) and benzyl benzoate, he recovered and had no more symptoms of lead poisoning until his death from cancer several years later. Each of the three involved an animal whose daily activities exposed him to the continual presence of gasolines and exhaust fumes containing tetraethyl lead.

  20. The effects of prepulse-blink reflex trial repetition and prepulse change on blink reflex modification at short and long lead intervals.

    Science.gov (United States)

    Lipp, O V; Siddle, D A

    1998-01-01

    Prepulse inhibition and facilitation of the blink reflex are said to reflect different responses elicited by the lead stimulus, transient detection and orienting response respectively. Two experiments investigated the effects of trial repetition and lead stimulus change on blink modification. It was hypothesized that these manipulations will affect orienting and thus blink facilitation to a greater extent than they will affect transient detection and thus blink inhibition. In Experiment 1 (N = 64), subjects were trained with a sequence of 12 lead stimulus and 12 blink stimulus alone presentations, and 24 lead stimulus-blink stimulus pairings. Lead interval was 120 ms for 12 of the trials and 2000 ms for the other 12. For half the subjects this sequence was followed by a change in pitch of the lead stimulus. In Experiment 2 (N = 64), subjects were trained with a sequence of 36 blink alone stimuli and 36 lead stimulus-blink stimulus pairings. The lead interval was 120 ms for half the subjects and 2000 ms for the other half. The pitch of the lead stimulus on prestimulus trials 31-33 was changed for half the subjects in each group. In both experiments, the amount of blink inhibition decreased during training whereas the amount of blink facilitation remained unchanged. Lead stimulus change had no effect on blink modification in either experiment although it resulted in enhanced skin conductance responses and greater heart rate deceleration in Experiment 2. The present results are not consistent with the notion that blink facilitation is linked to orienting whereas blink inhibition reflects a transient detection mechanism.

  1. Large polarons in lead halide perovskites

    Science.gov (United States)

    Miyata, Kiyoshi; Meggiolaro, Daniele; Trinh, M. Tuan; Joshi, Prakriti P.; Mosconi, Edoardo; Jones, Skyler C.; De Angelis, Filippo; Zhu, X.-Y.

    2017-01-01

    Lead halide perovskites show marked defect tolerance responsible for their excellent optoelectronic properties. These properties might be explained by the formation of large polarons, but how they are formed and whether organic cations are essential remain open questions. We provide a direct time domain view of large polaron formation in single-crystal lead bromide perovskites CH3NH3PbBr3 and CsPbBr3. We found that large polaron forms predominantly from the deformation of the PbBr3− frameworks, irrespective of the cation type. The difference lies in the polaron formation time, which, in CH3NH3PbBr3 (0.3 ps), is less than half of that in CsPbBr3 (0.7 ps). First-principles calculations confirm large polaron formation, identify the Pb-Br-Pb deformation modes as responsible, and explain quantitatively the rate difference between CH3NH3PbBr3 and CsPbBr3. The findings reveal the general advantage of the soft [PbX3]− sublattice in charge carrier protection and suggest that there is likely no mechanistic limitations in using all-inorganic or mixed-cation lead halide perovskites to overcome instability problems and to tune the balance between charge carrier protection and mobility. PMID:28819647

  2. Impact of historical mining assessed in soils by kinetic extraction and lead isotopic ratios

    International Nuclear Information System (INIS)

    Camizuli, E.; Monna, F.; Bermond, A.; Manouchehri, N.; Besançon, S.; Losno, R.; Oort, F. van; Labanowski, J.; Perreira, A.; Chateau, C.; Alibert, P.

    2014-01-01

    The aim of this study is to estimate the long-term behaviour of trace metals, in two soils differently impacted by past mining. Topsoils from two 1 km 2 zones in the forested Morvan massif (France) were sampled to assess the spatial distribution of Cd, Cu, Pb and Zn. The first zone had been contaminated by historical mining. As expected, it exhibits higher trace-metal levels and greater spatial heterogeneity than the second non-contaminated zone, supposed to represent the local background. One soil profile from each zone was investigated in detail to estimate metal behaviour, and hence, bioavailability. Kinetic extractions were performed using EDTA on three samples: the A horizon from both soil profiles and the B horizon from the contaminated soil. For all three samples, kinetic extractions can be modelled by two first-order reactions. Similar kinetic behaviour was observed for all metals, but more metal was extracted from the contaminated A horizon than from the B horizon. More surprising is the general predominance of the residual fraction over the “labile” and “less labile” pools. Past anthropogenic inputs may have percolated over time through the soil profiles because of acidic pH conditions. Stable organo-metallic complexes may also have been formed over time, reducing metal availability. These processes are not mutually exclusive. After kinetic extraction, the lead isotopic compositions of the samples exhibited different signatures, related to contamination history and intrinsic soil parameters. However, no variation in lead signature was observed during the extraction experiment, demonstrating that the “labile” and “less labile” lead pools do not differ in terms of origin. Even if trace metals resulting from past mining and metallurgy persist in soils long after these activities have ceased, kinetic extractions suggest that metals, at least for these particular forest soils, do not represent a threat for biota. - Highlights: • Trace

  3. Impact of historical mining assessed in soils by kinetic extraction and lead isotopic ratios

    Energy Technology Data Exchange (ETDEWEB)

    Camizuli, E., E-mail: estelle.camizuli@u-bourgogne.fr [UMR 6298, ArTeHiS, Université de Bourgogne — CNRS — Culture, 6 bd Gabriel, Bat. Gabriel, 21000 Dijon (France); Monna, F. [UMR 6298, ArTeHiS, Université de Bourgogne — CNRS — Culture, 6 bd Gabriel, Bat. Gabriel, 21000 Dijon (France); Bermond, A.; Manouchehri, N.; Besançon, S. [Institut des sciences et industries du vivant et de l' environnement (AgroParisTech), Laboratoire de Chimie Analytique, 16, rue Claude Bernard, 75231 Paris Cedex 05 (France); Losno, R. [UMR 7583, LISA, Universités Paris 7-Paris 12 — CNRS, 61 av. du Gal de Gaulle, 94010 Créteil Cedex (France); Oort, F. van [UR 251, Pessac, Institut National de la Recherche Agronomique, Centre de Versailles-Grignon, RD 10, 78026 Versailles Cedex (France); Labanowski, J. [UMR 7285, IC2MP, Université de Poitiers — CNRS, 4, rue Michel Brunet, 86022 Poitiers (France); Perreira, A. [UMR 6298, ArTeHiS, Université de Bourgogne — CNRS — Culture, 6 bd Gabriel, Bat. Gabriel, 21000 Dijon (France); Chateau, C. [UFR SVTE, Université de Bourgogne, 6 bd Gabriel, Bat. Gabriel, 21000 Dijon (France); Alibert, P. [UMR 6282, Biogeosciences, Université de Bourgogne — CNRS, 6 bd Gabriel, Bat. Gabriel, 21000 Dijon (France)

    2014-02-01

    The aim of this study is to estimate the long-term behaviour of trace metals, in two soils differently impacted by past mining. Topsoils from two 1 km{sup 2} zones in the forested Morvan massif (France) were sampled to assess the spatial distribution of Cd, Cu, Pb and Zn. The first zone had been contaminated by historical mining. As expected, it exhibits higher trace-metal levels and greater spatial heterogeneity than the second non-contaminated zone, supposed to represent the local background. One soil profile from each zone was investigated in detail to estimate metal behaviour, and hence, bioavailability. Kinetic extractions were performed using EDTA on three samples: the A horizon from both soil profiles and the B horizon from the contaminated soil. For all three samples, kinetic extractions can be modelled by two first-order reactions. Similar kinetic behaviour was observed for all metals, but more metal was extracted from the contaminated A horizon than from the B horizon. More surprising is the general predominance of the residual fraction over the “labile” and “less labile” pools. Past anthropogenic inputs may have percolated over time through the soil profiles because of acidic pH conditions. Stable organo-metallic complexes may also have been formed over time, reducing metal availability. These processes are not mutually exclusive. After kinetic extraction, the lead isotopic compositions of the samples exhibited different signatures, related to contamination history and intrinsic soil parameters. However, no variation in lead signature was observed during the extraction experiment, demonstrating that the “labile” and “less labile” lead pools do not differ in terms of origin. Even if trace metals resulting from past mining and metallurgy persist in soils long after these activities have ceased, kinetic extractions suggest that metals, at least for these particular forest soils, do not represent a threat for biota. - Highlights: • Trace

  4. Real time and in situ determination of lead in road sediments using a man-portable laser-induced breakdown spectroscopy analyzer

    Energy Technology Data Exchange (ETDEWEB)

    Cunat, J.; Fortes, F.J. [Department of Analytical Chemistry, University of Malaga, E-29071 Malaga (Spain); Laserna, J.J. [Department of Analytical Chemistry, University of Malaga, E-29071 Malaga (Spain)], E-mail: laserna@uma.es

    2009-02-02

    In situ, real time levels of lead in road sediments have been measured using a man-portable laser-induced breakdown spectroscopy analyzer. The instrument consists of a backpack and a probe housing a Q-switched Nd:YAG laser head delivering 50 mJ per pulse at 1064 nm. Plasma emission was collected and transmitted via fiber optic to a compact cross Czerny-Turner spectrometer equipped with a linear CCD array allocated in the backpack together with a personal computer. The limit of detection (LOD) for lead and the precision measured in the laboratory were 190 {mu}g g{sup -1} (calculated by the 3{sigma} method) and 9% R.S.D. (relative standard deviation), respectively. During the field campaign, averaged Pb concentration in the sediments were ranging from 480 {mu}g g{sup -1} to 660 {mu}g g{sup -1} depending on the inspected area, i.e. the entrance, the central part and the exit of the tunnel. These results were compared with those obtained with flame-atomic absorption spectrometry (flame-AAS). The relative error, expressed as [100(LIBS result - flame AAS result)/(LIBS result)], was approximately 14%.

  5. Early Childhood Lead Exposure and Academic Achievement: Evidence From Detroit Public Schools, 2008–2010

    Science.gov (United States)

    Baker, Harolyn W.; Tufts, Margaret; Raymond, Randall E.; Salihu, Hamisu; Elliott, Michael R.

    2013-01-01

    Objectives. We assessed the long-term effect of early childhood lead exposure on academic achievement in mathematics, science, and reading among elementary and junior high school children. Methods. We linked early childhood blood lead testing surveillance data from the Detroit Department of Health and Wellness Promotion to educational testing data from the Detroit, Michigan, public schools. We used the linked data to investigate the effect of early childhood lead exposure on academic achievement among school-aged children, both marginally and adjusted for grade level, gender, race, language, maternal education, and socioeconomic status. Results. High blood lead levels before age 6 years were strongly associated with poor academic achievement in grades 3, 5, and 8. The odds of scoring less than proficient for those whose blood lead levels were greater than 10 micrograms per deciliter were more than twice the odds for those whose blood lead levels were less than 1 micrograms per deciliter after adjustment for potential confounders. Conclusions. Early childhood lead exposure was negatively associated with academic achievement in elementary and junior high school, after adjusting for key potential confounders. The control of lead poisoning should focus on primary prevention of lead exposure in children and development of special education programs for students with lead poisoning. PMID:23327265

  6. Off-line correction for excessive constant-fraction-discriminator walk in neutron time-of-flight experiments

    International Nuclear Information System (INIS)

    Heilbronn, L.; Iwata, Y.; Iwase, H.

    2004-01-01

    A method for reducing excessive constant-fraction-discriminator walk that utilizes experimental data in the off-line analysis stage is introduced. Excessive walk is defined here as any walk that leads to an overall timing resolution that is much greater than the intrinsic timing resolution of the detection system. The method is able to reduce the contribution to the overall timing resolution from the walk to a value that is equal to or less than the intrinsic timing resolution of the detectors. Although the method is explained in the context of a neutron time-of-flight experiment, it is applicable to any data set that satisfies two conditions: (1) a measure of the signal amplitude for each event must be recorded on an event-by-event basis; and (2) there must be a distinguishable class of events present where the timing information is known a priori

  7. Lead and lead-based alloys as waste matrix materials

    International Nuclear Information System (INIS)

    Arustamov, A.E.; Ojovan, M.I.; Kachalov, M.B.

    1999-01-01

    Metals and alloys with relatively low melting temperatures such as lead and lead-based alloys are considered in Russia as prospective matrices for encapsulation of spent nuclear fuel in containers in preparation for final disposal in underground repositories. Now lead and lead-based alloys are being used for conditioning spent sealed radioactive sources at radioactive waste disposal facilities

  8. Stress enhances fear by forming new synapses with greater capacity for long-term potentiation in the amygdala.

    Science.gov (United States)

    Suvrathan, Aparna; Bennur, Sharath; Ghosh, Supriya; Tomar, Anupratap; Anilkumar, Shobha; Chattarji, Sumantra

    2014-01-05

    Prolonged and severe stress leads to cognitive deficits, but facilitates emotional behaviour. Little is known about the synaptic basis for this contrast. Here, we report that in rats subjected to chronic immobilization stress, long-term potentiation (LTP) and NMDA receptor (NMDAR)-mediated synaptic responses are enhanced in principal neurons of the lateral amygdala, a brain area involved in fear memory formation. This is accompanied by electrophysiological and morphological changes consistent with the formation of 'silent synapses', containing only NMDARs. In parallel, chronic stress also reduces synaptic inhibition. Together, these synaptic changes would enable amygdalar neurons to undergo further experience-dependent modifications, leading to stronger fear memories. Consistent with this prediction, stressed animals exhibit enhanced conditioned fear. Hence, stress may leave its mark in the amygdala by generating new synapses with greater capacity for plasticity, thereby creating an ideal neuronal substrate for affective disorders. These findings also highlight the unique features of stress-induced plasticity in the amygdala that are strikingly different from the stress-induced impairment of structure and function in the hippocampus.

  9. Lead poisoning

    Science.gov (United States)

    ... drinking water in homes containing pipes that were connected with lead solder . Although new building codes require ... lead in their bodies when they put lead objects in their mouths, especially if they swallow those ...

  10. Greater general startle reflex is associated with greater anxiety levels: a correlational study on 111 young women

    Directory of Open Access Journals (Sweden)

    Eleonora ePoli

    2015-02-01

    Full Text Available Startle eyeblink reflex is a valid non-invasive tool for studying attention, emotion and psychiatric disorders. In the absence of any experimental manipulation, the general (or baseline startle reflex shows a high inter-individual variability, which is often considered task-irrelevant and therefore normalized across participants. Unlike the above view, we hypothesized that greater general startle magnitude is related to participants’ higher anxiety level. 111 healthy young women, after completing the State-Trait Anxiety Inventory, were randomly administered 10 acoustic white noise probes (50 ms, 100 dBA acoustic level while integrated EMG from left and right orbicularis oculi was recorded. Results showed that participants with greater state anxiety levels exhibited larger startle reflex magnitude from the left eye (r109=0.23, p<0.05. Furthermore, individuals who perceived the acoustic probe as more aversive reported the largest anxiety scores (r109=0.28, p<0.05 and had the largest eyeblinks, especially in the left eye (r109 = 0.34, p<0.001. Results suggest that general startle may represent a valid tool for studying the neural excitability underlying anxiety and emotional dysfunction in neurological and mental disorders.

  11. Predictability of Seasonal Rainfall over the Greater Horn of Africa

    Science.gov (United States)

    Ngaina, J. N.

    2016-12-01

    The El Nino-Southern Oscillation (ENSO) is a primary mode of climate variability in the Greater of Africa (GHA). The expected impacts of climate variability and change on water, agriculture, and food resources in GHA underscore the importance of reliable and accurate seasonal climate predictions. The study evaluated different model selection criteria which included the Coefficient of determination (R2), Akaike's Information Criterion (AIC), Bayesian Information Criterion (BIC), and the Fisher information approximation (FIA). A forecast scheme based on the optimal model was developed to predict the October-November-December (OND) and March-April-May (MAM) rainfall. The predictability of GHA rainfall based on ENSO was quantified based on composite analysis, correlations and contingency tables. A test for field-significance considering the properties of finiteness and interdependence of the spatial grid was applied to avoid correlations by chance. The study identified FIA as the optimal model selection criterion. However, complex model selection criteria (FIA followed by BIC) performed better compared to simple approach (R2 and AIC). Notably, operational seasonal rainfall predictions over the GHA makes of simple model selection procedures e.g. R2. Rainfall is modestly predictable based on ENSO during OND and MAM seasons. El Nino typically leads to wetter conditions during OND and drier conditions during MAM. The correlations of ENSO indices with rainfall are statistically significant for OND and MAM seasons. Analysis based on contingency tables shows higher predictability of OND rainfall with the use of ENSO indices derived from the Pacific and Indian Oceans sea surfaces showing significant improvement during OND season. The predictability based on ENSO for OND rainfall is robust on a decadal scale compared to MAM. An ENSO-based scheme based on an optimal model selection criterion can thus provide skillful rainfall predictions over GHA. This study concludes that the

  12. Encounters with Pinyon-Juniper influence riskier movements in Greater Sage-Grouse across the Great Basin

    Science.gov (United States)

    Prochazka, Brian; Coates, Peter S.; Ricca, Mark; Casazza, Michael L.; Gustafson, K. Ben; Hull, Josh M.

    2016-01-01

    Fine-scale spatiotemporal studies can better identify relationships between individual survival and habitat fragmentation so that mechanistic interpretations can be made at the population level. Recent advances in Global Positioning System (GPS) technology and statistical models capable of deconstructing high-frequency location data have facilitated interpretation of animal movement within a behaviorally mechanistic framework. Habitat fragmentation due to singleleaf pinyon (Pinus monophylla; hereafter pinyon) and Utah juniper (Juniperus osteosperma; hereafter juniper) encroachment into sagebrush (Artemisia spp.) communities is a commonly implicated perturbation that can adversely influence greater sage-grouse (Centrocercus urophasianus; hereafter sage-grouse) demographic rates. Using an extensive GPS data set (233 birds and 282,954 locations) across 12 study sites within the Great Basin, we conducted a behavioral change point analysis and subsequently constructed Brownian bridge movement models from each behaviorally homogenous section. We found a positive relationship between modeled movement rate and probability of encountering pinyon-juniper with significant variation among age classes. The probability of encountering pinyon-juniper among adults was two and three times greater than that of yearlings and juveniles, respectively. However, the movement rate in response to the probability of encountering pinyon-juniper trees was 1.5 times greater for juveniles. We then assessed the risk of mortality associated with an interaction between movement rate and the probability of encountering pinyon-juniper using shared frailty models. During pinyon-juniper encounters, on average, juvenile, yearling, and adult birds experienced a 10.4%, 0.2%, and 0.3% reduction in annual survival probabilities. Populations that used pinyon-juniper habitats with a frequency ≥ 3.8 times the overall mean experienced decreases in annual survival probabilities of 71.1%, 0.9%, and 0.9%. This

  13. Optimal (R, Q) policy and pricing for two-echelon supply chain with lead time and retailer's service-level incomplete information

    Science.gov (United States)

    Esmaeili, M.; Naghavi, M. S.; Ghahghaei, A.

    2018-03-01

    Many studies focus on inventory systems to analyze different real-world situations. This paper considers a two-echelon supply chain that includes one warehouse and one retailer with stochastic demand and an up-to-level policy. The retailer's lead time includes the transportation time from the warehouse to the retailer that is unknown to the retailer. On the other hand, the warehouse is unaware of retailer's service level. The relationship between the retailer and the warehouse is modeled based on the Stackelberg game with incomplete information. Moreover, their relationship is presented when the warehouse and the retailer reveal their private information using the incentive strategies. The optimal inventory and pricing policies are obtained using an algorithm based on bi-level programming. Numerical examples, including sensitivity analysis of some key parameters, will compare the results between the Stackelberg models. The results show that information sharing is more beneficial to the warehouse rather than the retailer.

  14. Radiation shielding and effective atomic number studies in different types of shielding concretes, lead base and non-lead base glass systems for total electron interaction: A comparative study

    International Nuclear Information System (INIS)

    Kurudirek, Murat

    2014-01-01

    Highlights: • Radiation shielding calculations for concretes and glass systems. • Assigning effective atomic number for the given materials for total electron interaction. • Glass systems generally have better shielding ability than concretes. - Abstract: Concrete has been widely used as a radiation shielding material due to its extremely low cost. On the other hand, glass systems, which make everything inside visible to observers, are considered as promising shielding materials as well. In the present work, the effective atomic numbers, Z eff of some concretes and glass systems (industrial waste containing glass, Pb base glass and non-Pb base glass) have been calculated for total electron interaction in the energy region of 10 keV–1 GeV. Also, the continuous slowing down approximation (CSDA) ranges for the given materials have been calculated in the wide energy region to show the shielding effectiveness of the given materials. The glass systems are not only compared to different types of concretes but also compared to the lead base glass systems in terms of shielding. Moreover, the obtained results for total electron interaction have been compared to the results for total photon interaction wherever possible. In general, it has been observed that the glass systems have superior properties than most of the concretes over the high-energy region with respect to the electron interaction. Also, glass systems without lead show better electron stopping than lead base glasses at some energy regions as well. Along with the photon attenuation capability, it is seen that Fly Ash base glass systems have not only greater electron stopping capability but also have greater photon attenuation especially in high energy region when compared with standard shielding concretes

  15. Radiation shielding and effective atomic number studies in different types of shielding concretes, lead base and non-lead base glass systems for total electron interaction: A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Kurudirek, Murat, E-mail: mkurudirek@gmail.com

    2014-12-15

    Highlights: • Radiation shielding calculations for concretes and glass systems. • Assigning effective atomic number for the given materials for total electron interaction. • Glass systems generally have better shielding ability than concretes. - Abstract: Concrete has been widely used as a radiation shielding material due to its extremely low cost. On the other hand, glass systems, which make everything inside visible to observers, are considered as promising shielding materials as well. In the present work, the effective atomic numbers, Z{sub eff} of some concretes and glass systems (industrial waste containing glass, Pb base glass and non-Pb base glass) have been calculated for total electron interaction in the energy region of 10 keV–1 GeV. Also, the continuous slowing down approximation (CSDA) ranges for the given materials have been calculated in the wide energy region to show the shielding effectiveness of the given materials. The glass systems are not only compared to different types of concretes but also compared to the lead base glass systems in terms of shielding. Moreover, the obtained results for total electron interaction have been compared to the results for total photon interaction wherever possible. In general, it has been observed that the glass systems have superior properties than most of the concretes over the high-energy region with respect to the electron interaction. Also, glass systems without lead show better electron stopping than lead base glasses at some energy regions as well. Along with the photon attenuation capability, it is seen that Fly Ash base glass systems have not only greater electron stopping capability but also have greater photon attenuation especially in high energy region when compared with standard shielding concretes.

  16. Lead content of roadside fruit and berries

    Energy Technology Data Exchange (ETDEWEB)

    Fowles, G W.A.

    1976-01-01

    Blackberries, elderberries, hawthorn berries, holly berries and rose hips have been examined for their lead content, which has been shown to be directly related to the proximity of the growing fruit and berries to roads, the traffic density and the time of exposure. The maximum levels found (in ppm for undried fruit and berries) were blackberries 0.85, elderberries 6.77, hawthorn berries 23.8, holly berries 3.5 and rose hips 1.45. Very thorough washing with water removed 40-60% of the lead from heavily contaminated fruit and berries. When elderberries were used for winemaking over 60% of the lead was extracted and remained in solution in the wine. 25 references, 4 tables.

  17. Observations of territorial breeding common ravens caching eggs of greater sage-grouse

    Science.gov (United States)

    Howe, Kristy B.; Coates, Peter S.

    2015-01-01

    Previous investigations using continuous video monitoring of greater sage-grouse Centrocercus urophasianus nests have unambiguously identified common ravens Corvus corax as an important egg predator within the western United States. The quantity of greater sage-grouse eggs an individual common raven consumes during the nesting period and the extent to which common ravens actively hunt greater sage-grouse nests are largely unknown. However, some evidence suggests that territorial breeding common ravens, rather than nonbreeding transients, are most likely responsible for nest depredations. We describe greater sage-grouse egg depredation observations obtained opportunistically from three common raven nests located in Idaho and Nevada where depredated greater sage-grouse eggs were found at or in the immediate vicinity of the nest site, including the caching of eggs in nearby rock crevices. We opportunistically monitored these nests by counting and removing depredated eggs and shell fragments from the nest sites during each visit to determine the extent to which the common raven pairs preyed on greater sage-grouse eggs. To our knowledge, our observations represent the first evidence that breeding, territorial pairs of common ravens cache greater sage-grouse eggs and are capable of depredating multiple greater sage-grouse nests.

  18. Lead Poisoning

    Science.gov (United States)

    Lead is a metal that occurs naturally in the earth's crust. Lead can be found in all parts of our ... from human activities such as mining and manufacturing. Lead used to be in paint; older houses may ...

  19. Comparative Education in Greater China: Contexts, Characteristics, Contrasts and Contributions.

    Science.gov (United States)

    Bray, Mark; Qin, Gui

    2001-01-01

    The evolution of comparative education in Greater China (mainland China, Taiwan, Hong Kong, and Macau) has been influenced by size, culture, political ideologies, standard of living, and colonialism. Similarities and differences in conceptions of comparative education are identified among the four components and between Greater China and other…

  20. Co-remediation of the lead-polluted garden soil by exogenous natural zeolite and humic acids.

    Science.gov (United States)

    Shi, Wei-yu; Shao, Hong-bo; Li, Hua; Shao, Ming-an; Du, Sheng

    2009-08-15

    The current study reported the co-remediation effect on the lead-polluted garden soil by zeolite and humic acids (HA), which was from comparing with the remediation of single zeolite in term of the lead fraction of sequential extraction in the soil and the distribution of lead in different parts of rape. Mixed treatment (zeolite and HA) and single treatment (zeolite) were, respectively, applied to the artificially polluted garden soil to examine the difference of their remediation effects in pot experiment. Results indicated that the co-remediation led to significantly greater (plead concentration in plants than by singly adding to zeolite. The co-application of zeolite and HA reduced the available fraction of lead compounds, but slightly increased (plead compounds in the garden soil, compared with the application of single zeolite, especially in the severe lead-polluted soil (> or =1000 mg kg(-1)). This method might be an efficient way to remediate the lead-polluted soils on a large scale, although zeolite is a kind of hazardous material.

  1. Active convergence between the Lesser and Greater Caucasus in Georgia: Constraints on the tectonic evolution of the Lesser-Greater Caucasus continental collision

    Science.gov (United States)

    Sokhadze, G.; Floyd, M.; Godoladze, T.; King, R.; Cowgill, E. S.; Javakhishvili, Z.; Hahubia, G.; Reilinger, R.

    2018-01-01

    We present and interpret newly determined site motions derived from GPS observations made from 2008 through 2016 in the Republic of Georgia, which constrain the rate and locus of active shortening in the Lesser-Greater Caucasus continental collision zone. Observation sites are located along two ∼160 km-long profiles crossing the Lesser-Greater Caucasus boundary zone: one crossing the Rioni Basin in western Georgia and the other crossing further east near the longitude of Tbilisi. Convergence across the Rioni Basin Profile occurs along the southern margin of the Greater Caucasus, near the surface trace of the north-dipping Main Caucasus Thrust Fault (MCTF) system, and is consistent with strain accumulation on the fault that generated the 1991 MW6.9 Racha earthquake. In contrast, convergence along the Tbilisi Profile occurs near Tbilisi and the northern boundary of the Lesser Caucasus (near the south-dipping Lesser Caucasus Thrust Fault), approximately 50-70 km south of the MCTF, which is inactive within the resolution of geodetic observations (< ± 0.5 mm/yr) at the location of the Tbilisi Profile. We suggest that the southward offset of convergence along strike of the range is related to the incipient collision of the Lesser-Greater Caucasus, and closing of the intervening Kura Basin, which is most advanced along this segment of the collision zone. The identification of active shortening near Tbilisi requires a reevaluation of seismic hazards in this area.

  2. Selfsimilar time dependent shock structures

    International Nuclear Information System (INIS)

    Beck, R.; Drury, L.O.

    1985-01-01

    Diffusive shock acceleration as an astrophysical mechanism for accelerating charged particles has the advantage of being highly efficient. This means however that the theory is of necessity nonlinear; the reaction of the accelerated particles on the shock structure and the acceleration process must be self-consistently included in any attempt to develop a complete theory of diffusive shock acceleration. Considerable effort has been invested in attempting, at least partially, to do this and it has become clear that in general either the maximum particle energy must be restricted by introducing additional loss processes into the problem or the acceleration must be treated as a time dependent problem (Drury, 1984). It is concluded that stationary modified shock structures can only exist for strong shocks if additional loss processes limit the maximum energy a particle can attain. This is certainly possible and if it occurs the energy loss from the shock will lead to much greater shock compressions. It is however equally possible that no such processes exist and we must then ask what sort of nonstationary shock structure develops. The same argument which excludes stationary structures also rules out periodic solutions and indeed any solution where the width of the shock remains bounded. It follows that the width of the shock must increase secularly with time and it is natural to examine the possibility of selfsimilar time dependent solutions

  3. Selfsimilar time dependent shock structures

    Science.gov (United States)

    Beck, R.; Drury, L. O.

    1985-01-01

    Diffusive shock acceleration as an astrophysical mechanism for accelerating charged particles has the advantage of being highly efficient. This means however that the theory is of necessity nonlinear; the reaction of the accelerated particles on the shock structure and the acceleration process must be self-consistently included in any attempt to develop a complete theory of diffusive shock acceleration. Considerable effort has been invested in attempting, at least partially, to do this and it has become clear that in general either the maximum particle energy must be restricted by introducing additional loss processes into the problem or the acceleration must be treated as a time dependent problem (Drury, 1984). It is concluded that stationary modified shock structures can only exist for strong shocks if additional loss processes limit the maximum energy a particle can attain. This is certainly possible and if it occurs the energy loss from the shock will lead to much greater shock compressions. It is however equally possible that no such processes exist and we must then ask what sort of nonstationary shock structure develops. The ame argument which excludes stationary structures also rules out periodic solutions and indeed any solution where the width of the shock remains bounded. It follows that the width of the shock must increase secularly with time and it is natural to examine the possibility of selfsimilar time dependent solutions.

  4. Role of sintering time, crystalline phases and symmetry in the piezoelectric properties of lead-free KNN-modified ceramics

    International Nuclear Information System (INIS)

    Rubio-Marcos, F.; Marchet, P.; Merle-Mejean, T.; Fernandez, J.F.

    2010-01-01

    Lead-free KNN-modified piezoceramics of the system (Li,Na,K)(Nb,Ta,Sb)O 3 were prepared by conventional solid-state sintering. The X-ray diffraction patterns revealed a perovskite phase, together with some minor secondary phase, which was assigned to K 3 LiNb 6 O 17 , tetragonal tungsten-bronze (TTB). A structural evolution toward a pure tetragonal structure with the increasing sintering time was observed, associated with the decrease of TTB phase. A correlation between higher tetragonality and higher piezoelectric response was clearly evidenced. Contrary to the case of the LiTaO 3 modified KNN, very large abnormal grains with TTB structure were not detected. As a consequence, the simultaneous modification by tantalum and antimony seems to induce during sintering a different behaviour from the one of LiTaO 3 modified KNN.

  5. Role of sintering time, crystalline phases and symmetry in the piezoelectric properties of lead-free KNN-modified ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Rubio-Marcos, F., E-mail: frmarcos@icv.csic.es [Electroceramic Department, Instituto de Ceramica y Vidrio, CSIC, Kelsen 5, 28049 Madrid (Spain); Marchet, P.; Merle-Mejean, T. [SPCTS, UMR 6638 CNRS, Universite de Limoges, 123, Av. A. Thomas, 87060 Limoges (France); Fernandez, J.F. [Electroceramic Department, Instituto de Ceramica y Vidrio, CSIC, Kelsen 5, 28049 Madrid (Spain)

    2010-09-01

    Lead-free KNN-modified piezoceramics of the system (Li,Na,K)(Nb,Ta,Sb)O{sub 3} were prepared by conventional solid-state sintering. The X-ray diffraction patterns revealed a perovskite phase, together with some minor secondary phase, which was assigned to K{sub 3}LiNb{sub 6}O{sub 17}, tetragonal tungsten-bronze (TTB). A structural evolution toward a pure tetragonal structure with the increasing sintering time was observed, associated with the decrease of TTB phase. A correlation between higher tetragonality and higher piezoelectric response was clearly evidenced. Contrary to the case of the LiTaO{sub 3} modified KNN, very large abnormal grains with TTB structure were not detected. As a consequence, the simultaneous modification by tantalum and antimony seems to induce during sintering a different behaviour from the one of LiTaO{sub 3} modified KNN.

  6. Method of combined radionuclide assessment of the greater and uteroplacental circulation in plural pregnency

    International Nuclear Information System (INIS)

    Illarionova, N.M.; Fuks, M.A.; Ehventov, A.Z.

    1987-01-01

    The paper is concerned with the results of the clinical testing of a combined radionuclide method of assessment of the greater and uteroplacentral circulation in 15 women with plural pregnancy. The method permits the detection of hemodynamic changes without increasing radiation exposure to the mother's body and fetuses, the determination of a type of plural pregnancy (monochorionic or dichorial twins), and the prediction of pregnancy outcome that is very important for the choice of appropriate and timely therapy

  7. Spectroscopic studies of copper doped alkaline earth lead zinc phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Sastry, S. Sreehari, E-mail: sreeharisastry@yahoo.com [Department of Physics, Acharya Nagarjuna University, Nagarjunanagar 522510 (India); Rao, B. Rupa Venkateswara [Department of Physics, Acharya Nagarjuna University, Nagarjunanagar 522510 (India); Department of Physics, V.R. Siddhartha Engineering College, Vijayawada 52007 (India)

    2014-02-01

    In this paper spectroscopic investigation of Cu{sup 2+} doped alkaline earth lead zinc phosphate glasses was done through the spectroscopic techniques like X-ray diffraction, Ultra Violet (UV) absorption Spectroscopy, Electron Paramagnetic Resonance (EPR – X band), Fourier Transform Infra Red (FTIR) and Raman Spectroscopy. Alkaline earth lead zinc phosphate glasses containing 0.1% copper oxide (CuO) were prepared by the melt quenching technique. Spectroscopic studies indicated that there is a greater possibility for the copper ions to exist in Cu{sup 2+} state in these glasses. The optical absorption spectra indicated that the absorption peak of Cu{sup 2+} is a function of composition. The maxima absorption peak was reported at 862 nm for strontium lead zinc phosphate glass. Bonding parameters were calculated for the optical and EPR data. All these spectral results indicated clearly that there are certain structural changes in the present glass system with different alkaline earth contents. The IR and Raman spectra noticed the breaking of the P–O–P bonds and creating more number of new P–O–Cu bonds.

  8. Spectroscopic studies of copper doped alkaline earth lead zinc phosphate glasses

    International Nuclear Information System (INIS)

    Sastry, S. Sreehari; Rao, B. Rupa Venkateswara

    2014-01-01

    In this paper spectroscopic investigation of Cu 2+ doped alkaline earth lead zinc phosphate glasses was done through the spectroscopic techniques like X-ray diffraction, Ultra Violet (UV) absorption Spectroscopy, Electron Paramagnetic Resonance (EPR – X band), Fourier Transform Infra Red (FTIR) and Raman Spectroscopy. Alkaline earth lead zinc phosphate glasses containing 0.1% copper oxide (CuO) were prepared by the melt quenching technique. Spectroscopic studies indicated that there is a greater possibility for the copper ions to exist in Cu 2+ state in these glasses. The optical absorption spectra indicated that the absorption peak of Cu 2+ is a function of composition. The maxima absorption peak was reported at 862 nm for strontium lead zinc phosphate glass. Bonding parameters were calculated for the optical and EPR data. All these spectral results indicated clearly that there are certain structural changes in the present glass system with different alkaline earth contents. The IR and Raman spectra noticed the breaking of the P–O–P bonds and creating more number of new P–O–Cu bonds

  9. Progress and challenges in bipolar lead-acid battery development

    Science.gov (United States)

    Bullock, Kathryn R.

    1995-05-01

    Bipolar lead-acid batteries have higher power densities than any other aqueous battery system. Predicted specific powers based on models and prototypes range from 800 kW/kg for 100 ms discharge times to 1.6 kW/kg for 10 s. A 48 V automotive bipolar battery could have 2 1/2 times the cold cranking rate of a monopolar 12 V design in the same size. Problems which have precluded the development of commercial bipolar designs include the instability of substrate materials and enhanced side reactions. Design approaches include pseudo-bipolar configurations, as well as true bipolar designs in planar and tubular configurations. Substrate materials used include lead and lead alloys, carbons, conductive ceramics, and tin-oxide-coated glass fibers. These approaches are reviewed and evaluated.

  10. Lead Test

    Science.gov (United States)

    ... to do renovation and repair projects using lead-safe work practices to avoid creating more lead dust or ... in a dangerous area? Yes. If you are working in a potentially harmful environment with exposure to lead dust or fumes: Wash ...

  11. Leading in a Technological Age

    Science.gov (United States)

    Yadgir, Sheri A.

    2011-01-01

    Technology is advancing more rapidly than at any time in history since the beginning of the Industrial Revolution. In fact, experts say that the world is leaving the Industrial Age of the 20th century and entering an Information Age that will lead into the future. These advances mean that important changes are being made in all areas of life--and…

  12. Trunk and Shank Position Influences Patellofemoral Joint Stress in the Lead and Trail Limbs During the Forward Lunge Exercise.

    Science.gov (United States)

    Hofmann, Cory L; Holyoak, Derek T; Juris, Paul M

    2017-01-01

    Study Design Controlled laboratory study, repeated-measures design. Background The effects of trunk and shank position on patellofemoral joint stress of the lead limb have been well studied; however, the effects on the trail limb are not well understood. Objectives To test the hypothesis that trunk and shank position may influence patellofemoral joint stress in both limbs during the forward lunge exercise. Methods Patellofemoral kinetics were quantified from 18 healthy participants performing the lunge exercise with different combinations of trunk and shank positions (vertical or forward). A 2-by-3 (limb-by-lunge variation) repeated-measures analysis of variance was performed, using paired t tests for post hoc comparisons. Results The trail limb experienced greater total patellofemoral joint stress relative to the lead limb, regardless of trunk and shank position (Ppatellofemoral joint stress in the trail limb relative to the lead limb (Ppatellofemoral stress in the lead limb (Ppatellofemoral joint loading of both limbs during the forward lunge, with the trail limb generally experiencing greater total joint stress. Restricting forward translation of the lead-limb shank may reduce patellofemoral joint stress at the expense of increased stress in the trail limb. Technique recommendations should consider the demands imposed on both knees during this exercise. J Orthop Sports Phys Ther 2017;47(1):31-40. Epub 4 Nov 2016. doi:10.2519/jospt.2017.6336.

  13. Bulk diffusion and solubility of silver and nickel in lead, lead-silver and lead-nickel solid solutions

    International Nuclear Information System (INIS)

    Amenzou-Badrour, H.; Moya, G.; Bernardini, J.

    1988-01-01

    The results of a study of solubility and bulk diffusion of /sup 110/Ag and /sup 63/Ni in lead, lead-silver and lead-nickel solid solutions in the temperature range 220 to 88 0 C are reported. Owing to the low solubility of silver and nickel in lead, Fick's solution corresponding to the boundary condition of a constant concentration of solute at the surface has been used. Depth profile concentration analysis suggests a fundamental difference between the diffusion mechanisms of silver and nickel. Since silver penetration profiles in pure lead give diffusion coefficients independent of the penetration depth and silver concentration, it is suggested that slight decreases of silver diffusivity in lead-silver solid solutions have no significance. This implies that the interstitial silver atoms do not associate significantly with each other to form Ag-Ag dimers. In contrast, different behaviors of /sup 63/Ni depth profile concentration in pure lead and saturated PbNi solid solutions agree with a Ni-Ni interaction leading to the formation of less mobile dimers near the surface in pure lead

  14. Lower inhibitory control interacts with greater pain catastrophizing to predict greater pain intensity in women with migraine and overweight/obesity.

    Science.gov (United States)

    Galioto, Rachel; O'Leary, Kevin C; Thomas, J Graham; Demos, Kathryn; Lipton, Richard B; Gunstad, John; Pavlović, Jelena M; Roth, Julie; Rathier, Lucille; Bond, Dale S

    2017-12-01

    Pain catastrophizing (PC) is associated with more severe and disabling migraine attacks. However, factors that moderate this relationship are unknown. Failure of inhibitory control (IC), or the ability to suppress automatic or inappropriate responses, may be one such factor given previous research showing a relationship between higher PC and lower IC in non-migraine samples, and research showing reduced IC in migraine. Therefore, we examined whether lower IC interacts with increased PC to predict greater migraine severity as measured by pain intensity, attack frequency, and duration. Women (n = 105) aged 18-50 years old (M = 38.0 ± 1.2) with overweight/obesity and migraine who were seeking behavioral treatment for weight loss and migraine reduction completed a 28-day smartphone-based headache diary assessing migraine headache severity. Participants then completed a modified computerized Stroop task as a measure of IC and self-report measures of PC (Pain Catastrophizing Scale [PCS]), anxiety, and depression. Linear regression was used to examine independent and joint associations of PC and IC with indices of migraine severity after controlling for age, body mass index (BMI) depression, and anxiety. Participants on average had BMI of 35.1 ± 6.5 kg/m 2 and reported 5.3 ± 2.6 migraine attacks (8.3 ± 4.4 migraine days) over 28 days that produced moderate pain intensity (5.9 ± 1.4 out of 10) with duration of 20.0 ± 14.2 h. After adjusting for covariates, higher PCS total (β = .241, SE = .14, p = .03) and magnification subscale (β = .311, SE = .51, p migraine attacks. Future studies are needed to determine whether interventions to improve IC could lead to less painful migraine attacks via improvements in PC.

  15. Multimodal route choice models of public transport passengers in the Greater Copenhagen Area

    DEFF Research Database (Denmark)

    Anderson, Marie Karen; Nielsen, Otto Anker; Prato, Carlo Giacomo

    2014-01-01

    Understanding route choice behavior is crucial to explain travelers’ preferences and to predict traffic flows under different scenarios. A growing body of literature has concentrated on public transport users without, however, concentrating on multimodal public transport networks because......,641 public transport users in the Greater Copenhagen Area.A two-stage approach consisting of choice set generation and route choice model estimation allowed uncovering the preferences of the users of this multimodal large-scale public transport network. The results illustrate the rates of substitution...... not only of the in-vehicle times for different public transport modes, but also of the other time components (e.g., access, walking, waiting, transfer) composing the door-to-door experience of using a multimodal public transport network, differentiating by trip length and purpose, and accounting...

  16. [Discovery and follow-up of a lead-poisoning outbreak in a shantytown of Le Port, Reunion Island].

    Science.gov (United States)

    Solet, J-L; Renault, P; Denys, J-C; Teulé, G; Dennemont, R-M; Domonte, F; Garnier, C; Aubert, L; Filleul, L; Polycarpe, D

    2013-08-01

    A national survey conducted in 2008-2009 by the French Institute for Public Health Surveillance for detection of lead impact in childhood identified a high blood lead level in a young boy living in the town of "Le Port", Reunion Island. Previously, cases of lead-poisoning on the island had been exceptional; only a dozen cases were reported in the 1980s in adults, related to the use of lead-containing instruments for food preparations. The family of the index case was invited to participate in screening tests and an environmental investigation was conducted using a standardized questionnaire. Screening was then broadened to the neighborhood of the index case and samples of soil outside the home and in the immediate vicinity were taken. The environmental survey was then extended with soil samples taken from the entire geographical area. Information was then provided to local inhabitants (87 families and 287 people) in order to encourage lead blood testing for all children under six years and all pregnant women living in the area. The index case lived in the neighborhood of "The Oasis", a shantytown of Le Port. The results of soil analysis revealed heterogeneous pollution of superficial soils by lead throughout the area of the shantytown, the highest level recorded (5200mg/kg) reached more than 300 times the background level of the natural soils of the island. The screening identified 76 cases of childhood lead-poisoning (blood lead level greater or equal to 100μg/L) among 148 samples (51%). All cases of blood poisoning involved children under the age of 15 years. The median age of children with a positive test was 5.6 years; the median blood lead level was 196μg/L [102-392μg/L]. The main hypothesis to explain the contamination of the soil in the area of the shantytown is the presence of waste deposits (car batteries) and diffuse activities of metal recovery. The authorities managed to remove all the families from the environmental exposure to lead by

  17. Food chain transfer of cadmium and lead to cattle in a lead-zinc smelter in Guizhou, China

    International Nuclear Information System (INIS)

    Cai Qiu; Long Meili; Zhu Ming; Zhou Qingzhen; Zhang Ling; Liu Jie

    2009-01-01

    Cadmium (Cd) and Lead (Pb) are environmental pollutants. Environmental samples and bovine tissues were collected from the areas around a lead-zinc smelter in Guizhou, China for Cd, Pb, zinc (Zn) and copper (Cu) analysis. Cd in soil (10 mg/kg) and feed (6.6 mg/kg) from the polluted areas was 10 times higher than the Chinese Standards, resulting in higher Cd in bovine kidney (38 mg/kg) and liver (2.5 mg/kg). Pb in feed (132 mg/kg) from the polluted area was much higher than unpolluted areas, causing higher Pb levels in bovine tissues. Environmental Zn was elevated, but bovine tissue Zn was normal. Cu in bovine liver decreased with increased Cd and Pb. Metals in drinking water and in bovine muscle were within the Standard range. Thus, in the areas of this lead-zinc smelter, the environment has been contaminated with Cd and Pb, which has been transferred to cattle through the food chain. - Cd and Pb from lead-zinc smelters contaminate the environment and accumulate in bovine tissues.

  18. The change of β-adrenergic system after cessation of lead exposure

    International Nuclear Information System (INIS)

    Chang, H.-R.; Tsao, D.-A.; Yu, H.-S.; Ho, C.-K.

    2005-01-01

    For understanding a reversible or irreversible harm of β-adrenergic system in lead induced cardiovascular disease (hypertension), We set up animal model to estimate the change of blood pressure and sympathetic nervous system after lead exposure withdrawn in the study. We address three topics in this study: (a) the relationship between withdrawal time of lead exposure and β-adrenergic receptor, plasma catecholamine level, blood pressure, and lead level in heart, aorta, and kidney in lead-induced hypertensive rats after lead exposure stopped; (b) the relationship between blood pressure and β-adrenergic receptor in heart, aorta, and kidney; (c) the estimation of relationship between lead withdrawn and the variation of β-adrenergic system. Wistar rats were chronically fed with 2% lead acetate (experimental group) and water (control group) for 2 months. The rats were divided into 8 groups by withdrawal time of lead exposure stopped. Plasma catecholamine level was measured by high-performance liquid chromatography. Radioligand binding assay was measured by a method that fulfilled strict criteria of β-adrenergic receptor using the ligand [ 125 I]iodocyanopindolol. The levels of lead were determined by electrothermal atomic absorption spectrometry. The results showed that a close relation between reduced lead level and the plasma catecholamine level decreased, aorta β-adrenergic receptor increased, kidney β-adrenergic receptor diminished, heart β-adrenergic receptor increased, and blood pressure dropped after lead exposure withdrawn. The study on the regulation of β-adrenergic system in lead-induced hypertension after lead withdrawn might also provide insight about the nature of this disease state

  19. A high-performance, low-cost, leading edge discriminator

    Indian Academy of Sciences (India)

    Abstract. A high-performance, low-cost, leading edge discriminator has been designed with a timing performance comparable to state-of-the-art, commercially available discrim- inators. A timing error of 16 ps is achieved under ideal operating conditions. Under more realistic operating conditions the discriminator displays a ...

  20. Breeding of Greater and Lesser Flamingos at Sua Pan, Botswana ...

    African Journals Online (AJOL)

    to fledging was unknown owing to the rapid drying of the pan in late March 1999. No Greater Flamingo breeding was seen that season. Exceptional flooding during 1999–2000 produced highly favourable breeding conditions, with numbers of Greater and Lesser Flamingos breeding estimated to be 23 869 and 64 287 pairs, ...