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Uma proposta de sistema robótico para manipulação e interação física segura em ambientes não estruturados; A proposal of a robotic manipulation system for safe physical interaction in non-structured environments

Pedro, Leonardo Marquez
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 28/06/2013 PT
Relevância na Pesquisa
25.84%
Este trabalho propõe um sistema de manipulação robótica para interação física segura com objetos ou humanos em ambientes não estruturados. A proposta considera a execução de tarefas de manipulação e a prevenção e tratamento de colisões utilizando apenas uma lei de controle, o controle de impedância. A inovação científica consiste em um sistema multifuncional implementado com uma única lei de controle em contraste com os sistemas já existem que utilizam chaveamento entre controladores para cada diferente funcionalidade do sistema, e que apresentam diversas desvantagens como instabilidade e oscilações, aumento da complexidade de programação, entre outras. Inicialmente é proposto um planejador de manipulação e regrasping baseado na combinação de trajetórias suaves e na adaptação dos parâmetros de um controle de impedância em tempo de execução. A mudança da impedância para cada etapa é obtida pela modificação dos parâmetros de inércia, rigidez e amortecimento do controlador. A estabilidade desta mudança dinâmica é possível pela utilização de trajetórias suaves obtidas com planejador Squeezed Screw modificado, cujas trajetórias geradas são livres de descontinuidades na posição e na velocidade. Adicionalmente...

Incorporação de um sistema nobreak com ultracapacitor em um microcomputador

Gouvêa, Evaldo Chagas
Fonte: Universidade Estadual Paulista (UNESP) Publicador: Universidade Estadual Paulista (UNESP)
Tipo: Trabalho de Conclusão de Curso
POR
Relevância na Pesquisa
26.01%
The objective of this work is to analyze the viability of incorporation in a microcomputer box of a nobreak with an ultracapacitor as energy storage device, substituting the conventional chemical battery. An advantage of this inclusion is cost reduction because a specific metallic or plastic frame won’t be necessary to protect the components of the nobreak; the microcomputer metallic frame offers the necessary protection for both equipments. Moreover, a large quantity of internal space of microcomputers box isn’t used, and is possible to use it to wrap up the nobreak. This work uses data about average power consumption of microcomputers; operation of switching mode power supplies for microcomputers; electrical and mechanical characteristics of ultracapacitors and operation of power circuits of nobreaks, with the purpose of present a study of energy storage capacity that an ultracapacitor should have to allow a safe switching off of a microcomputer in case of electrical network fail. It was noticed that the use of ultracapacitors is feasible to feed an 180 W load for 75 s, using a capacitive bank with sixteen ultracapacitors, with a total capacitance of 350 F and voltage of 10,8 V. The use of the proposed nobreak increases the reliability of the microcomputer by reducing the probability of user data losses in case of an electrical network fail...

Recombinant Ochrobactrum anthropi Expressing Brucella abortus Cu,Zn Superoxide Dismutase Protects Mice against B. abortus Infection Only after Switching of Immune Responses to Th1 Type

He, Yongqun; Vemulapalli, Ramesh; Schurig, Gerhardt G.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /05/2002 EN
Relevância na Pesquisa
25.84%
The members of the genus Brucella are gram-negative, facultatively intracellular bacterial pathogens that cause brucellosis in many animal species and humans. Although live, attenuated vaccines are available to protect several animal species from the disease, there is no safe and effective vaccine for human use. Here we report that a bacterium that is closely related to Brucella species, Ochrobactrum anthropi, can be used as a vaccine vector for the delivery of Brucella antigens to mice, leading to the elicitation of protective immunity against brucellosis. Brucella abortus Cu,Zn superoxide dismutase (SOD), a protective Brucella antigen, was expressed in large amounts in O. anthropi strain 49237 by use of the broad-host-range plasmid pBBR1MCS. Neither O. anthropi strain 49237 nor the recombinant O. anthropi strain 49237SOD, expressing B. abortus Cu,Zn SOD, provided protection against virulent Brucella infection in mice. Analysis of immune responses indicated that strains 49237 and 49237SOD stimulated a mix of Th1 and Th2 type responses in the mice. After the immune response was switched to a Th1-biased response by addition of oligonucleotides containing unmethylated CpG motifs, both O. anthropi strain 49237 and the recombinant O. anthropi strain 49237SOD induced protection in mice. However...

A Fail-safe Mechanism for Negative Selection of Isotype-switched B Cell Precursors Is Regulated by the Fas/FasL Pathway

Seagal, Jane; Edry, Efrat; Keren, Zohar; Leider, Nira; Benny, Ofra; Machluf, Marcelle; Melamed, Doron
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 17/11/2003 EN
Relevância na Pesquisa
26.1%
In B lymphocytes, immunoglobulin (Ig)M receptors drive development and construction of naive repertoire, whereas IgG receptors promote formation of the memory B cell compartment. This isotype switching process requires appropriate B cell activation and T cell help. In the absence of T cell help, activated B cells undergo Fas-mediated apoptosis, a peripheral mechanism contributing to the establishment of self-tolerance. Using Igμ-deficient μMT mouse model, where B cell development is blocked at pro-B stage, here we show an alternative developmental pathway used by isotype-switched B cell precursors. We find that isotype switching occurs normally in B cell precursors and is T independent. Ongoing isotype switching was found in both normal and μMT B cell development as reflected by detection of IgG1 germline and postswitch transcripts as well as activation-induced cytidine deaminase expression, resulting in the generation of IgG-expressing cells. These isotype-switched B cells are negatively selected by Fas pathway, as blocking the Fas/FasL interaction rescues the development of isotype-switched B cells in vivo and in vitro. Similar to memory B cells, isotype-switched B cells have a marginal zone phenotype. We suggest a novel developmental pathway used by isotype-switched B cell precursors that effectively circumvents peripheral tolerance requirements. This developmental pathway...

Are the new SSRIs safe for pregnant women?

Kulin, N. A.; Pastuszak, A.; Koren, G.
Fonte: College of Family Physicians of Canada Publicador: College of Family Physicians of Canada
Tipo: Artigo de Revista Científica
Publicado em /10/1998 EN
Relevância na Pesquisa
26%
QUESTION: More and more of my female patients are switching to the new selective serotonin reuptake inhibitors. Are they safe during pregnancy? ANSWER: Our data suggest these drugs do not increase the malformation rate, but there are no data on neurodevelopment. Because such data do exist on fluoxetine and tricyclic antidepressants, those drugs should be considered first.

Promotion of well-switching to mitigate the current arsenic crisis in Bangladesh.

Van Geen, Alexander; Ahsan, Habibul; Horneman, Allan H.; Dhar, Ratan K.; Zheng, Yan; Hussain, Iftikhhar; Ahmed, Kazi Matin; Gelman, Andrew; Stute, Martin; Simpson, H. James; Wallace, Sean; Small, Christopher; Parvez, Faruque; Slavkovich, Vesna; Loiacono,
Fonte: World Health Organization Publicador: World Health Organization
Tipo: Artigo de Revista Científica
Publicado em //2002 EN
Relevância na Pesquisa
26.15%
OBJECTIVE: To survey tube wells and households in Araihazar upazila, Bangladesh, to set the stage for a long-term epidemiological study of the consequences of chronic arsenic exposure. METHODS: Water samples and household data were collected over a period of 4 months in 2000 from 4997 contiguous tube wells serving a population of 55000, the position of each well being determined to within +/- 30 m using Global Positioning System receivers. Arsenic concentrations were determined by graphite-furnace atomic-absorption spectrometry. In addition, groundwater samples collected every 2 weeks for an entire year from six tube wells were analysed for arsenic by high-resolution inductively coupled plasma-mass spectrometry. FINDINGS: Half of the wells surveyed in Araihazar had been installed in the previous 5 years; 94% were privately owned. Only about 48% of the surveyed wells supplied water with an arsenic content below 50 micro g/l, the current Bangladesh standard for drinking-water. Similar to other regions of Bangladesh and West Bengal, India, the distribution of arsenic in Araihazar is spatially highly variable (range: 5-860 micro g/l) and therefore difficult to predict. Because of this variability, however, close to 90% of the inhabitants live within 100 m of a safe well. Monitoring of six tube wells currently meeting the 50 micro g/l standard showed no indication of a seasonal cycle in arsenic concentrations coupled to the hydrological cycle. This suggests that well-switching is a viable option in Araihazar...

Initiating or Switching to Biphasic Insulin Aspart 30/70 Therapy in Subjects with Type 2 Diabetes Mellitus. An Observational Study

Breum, Leif; Almdal, Thomas; Eiken, Pia; Lund, Per; Christiansen, Erik; on behalf of the Danish BIAsp Study Group,
Fonte: SBDR - Society for Biomedical Diabetes Research Publicador: SBDR - Society for Biomedical Diabetes Research
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
26.01%
OBJECTIVE: To investigate tolerability and glycemic control over 26 weeks in patients with type 2 diabetes (T2D) who initiated insulin with, or switched to, biphasic insulin aspart 30/70 (BIAsp 30) in routine clinical care. METHODS: This was a non-randomized, non-interventional, open-label, observational study involving patients under the care of approximately 150 insulin-prescribing physicians in Denmark. All patients enrolled were prescribed BIAsp 30 in routine care. Starting dose, dose titration and injection frequency were determined individually by each physician. Information on serious adverse drug reactions (SADR), glycemic parameters and hypoglycemic events were obtained from patients’ notes, patients’ diaries and recall, and transferred to case report forms by physicians at baseline (during 4 weeks prior to BIAsp 30 therapy) and after 12 and 26 weeks of treatment. RESULTS: 421 subjects were recruited and 392 provided safety data. The age (mean ± SD) was 62.0 ± 11.4 years, body mass index (BMI) 30.4 ± 6.4 kg/m2, duration of diabetes 9.1 ± 8.1 years and HbA1c (%) 9.4 ± 1.7. 199 subjects were prior insulin users and 193 were insulin-naïve patients. Four patients reported a SADR (3 hypoglycemia, 1 severe hypoglycemia). HbA1c was significantly reduced after 26 weeks of BIAsp 30 therapy: prior insulin users -1.2%...

Safety and feasibility of switching from phenytoin to levetiracetam monotherapy for glioma-related seizure control following craniotomy: a randomized phase II pilot study

Lim, Daniel A.; Tarapore, Phiroz; Chang, Edward; Burt, Marlene; Chakalian, Lenna; Barbaro, Nicholas; Chang, Susan; Lamborn, Kathleen R.; McDermott, Michael W.
Fonte: Springer US Publicador: Springer US
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
26.01%
Seizures are common in patients with gliomas, and phenytoin (PHT) is frequently used to control tumor-related seizures. PHT, however, has many undesirable side effects (SEs) and drug interactions with glioma chemotherapy. Levetiracetam (LEV) is a newer antiepileptic drug (AED) with fewer SEs and essentially no drug interactions. We performed a pilot study testing the safety and feasibility of switching patients from PHT to LEV monotherapy for postoperative control of glioma-related seizures. Over a 13-month period, 29 patients were randomized in a 2:1 ratio to initiate LEV therapy within 24 h of surgery or to continue PHT therapy. 6 month follow-up data were available for 15 patients taking LEV and for 8 patients taking PHT. In the LEV group, 13 patients (87%) were seizure-free. In the PHT group, 6 patients (75%) were seizure-free. Reported SEs at 6 months was as follows (%LEV/%PHT group): dizziness (0/14), difficulty with coordination (0/29), depression (7/14) lack of energy or strength (20/43), insomnia (40/43), mood instability (7/0). The pilot data presented here suggest that it is safe to switch patients from PHT to LEV monotherapy following craniotomy for supratentorial glioma. A large-scale, double-blinded, randomized control trial of LEV versus PHT is required to determine seizure control equivalence and better assess differences in SEs.

Vitamin C acts indirectly to modulate isotype switching in mouse B cells

Woo, Ami; Kim, Jin-Hee; Jeong, Young-Joo; Maeng, Hyung Gun; Lee, Yong-Taek; Kang, Jae Seung; Lee, Wang Jae; Hwang, Young-il
Fonte: Korean Association of Anatomists Publicador: Korean Association of Anatomists
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
26.19%
Vitamin C, one of essential micronutrients, has been reported to modulate the humoral immune responses in some mammals. We investigated whether vitamin C might modulate this response in mice by directly affecting B cells. Splenic B cells were isolated and activated by CD40- and B cell receptor-ligation in vitro. The cells were cultured with a pretreatment of vitamin C from 0 to 1 mM of concentrations. Vitamin C slightly increased apoptosis of B cells dose-dependently and behaved as an antioxidant. We found that in vivo administration of vitamin C by intraperitoneal injection affected isotype switching as previously reported: the titer of antigen-specific IgG1 antibody was decreased, while that of IgG2a was unaffected. Somewhat different from those observed in vivo, in vitro exposure to vitamin C slightly decreased isotype switching to IgG1 and increased isotype switching to IgG2a. Pretreatment with vitamin C in the safe range did not affect either proliferation of cultured B cells or the expression of CD80 and CD86 in those cells. Taken together, in vivo results suggest that vitamin C acts to modulate isotype switching in the mouse. However, because of our in vitro results, we suggest that the modulation exerted by vitamin C in vivo is by indirectly affecting B cells...

Clinically meaningful treatment responses after switching to galantamine and with addition of memantine in patients with Alzheimer’s disease receiving donepezil

Kano, Osamu; Ito, Hirono; Takazawa, Takanori; Kawase, Yuji; Murata, Kiyoko; Iwamoto, Konosuke; Nagaoka, Tetsuro; Hirayama, Takehisa; Miura, Ken; Nagata, Riya; Kiyozuka, Tetsuhito; Aoyagi, Jo; Sato, Ryuta; Eguchi, Teruo; Ikeda, Ken; Iwasaki, Yasuo
Fonte: Dove Medical Press Publicador: Dove Medical Press
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
26.1%
Clinical trials have shown the benefits of acetylcholinesterase inhibitors, such as donepezil and galantamine, and an N-methyl-D-aspartate receptor antagonist, memantine, in patients with Alzheimer’s disease (AD). However, little is known regarding the effects of switching from donepezil 5 mg/day to galantamine 16 or 24 mg/day, or regarding the effects of adding memantine to established therapy compared with increasing the dose of donepezil. This report discusses two studies conducted to evaluate treatment with galantamine and memantine with respect to cognitive benefits and caregiver evaluations in patients with AD receiving donepezil 5 mg/day for more than 6 months. Patients with mild or moderate AD (scores 10–22 on the Mini-Mental State Examination) were enrolled in the Galantamine Switch study and switched to galantamine (maximum doses 16 mg versus 24 mg). Patients with moderate to severe AD (Mini-Mental State Examination scores 3–14) were enrolled in the Donepezil Increase versus Additional Memantine study and either had their donepezil dose increased to 10 mg/day or memantine 20 mg/day added to their existing donepezil dose. Patients received the study treatment for 28 weeks and their Disability Assessment for Dementia...

Effects of switching from a reduced dose imiglucerase to velaglucerase in type 1 Gaucher disease: clinical and biochemical outcomes

van Dussen, Laura; Cox, Timothy M.; Hendriks, Erik J.; Morris, Elizabeth; Akkerman, Erik M.; Maas, Mario; Groener, Johanna E. M.; Aerts, Johannes M.F.G.; Deegan, Patrick B.; Hollak, Carla E. M.
Fonte: Ferrata Storti Foundation Publicador: Ferrata Storti Foundation
Tipo: Artigo de Revista Científica
Publicado em /12/2012 EN
Relevância na Pesquisa
26.01%
This paper describes the effects of a switch to velaglucerase alfa in a group of adult patients with type 1 Gaucher disease, all of whom had previously had their dose reduced as a consequence of the worldwide imiglucerase shortage. Thirty-two patients from two large European Gaucher centers switched to treatment with velaglucerase alfa after 1-8.5 months of dose reduction. The course of important Gaucher disease parameters was studied at four time points: one year before the shortage, just before the shortage, before a switch to velaglucerase and after up to one year of treatment with velaglucerase. These parameters included hemoglobin concentration, platelet count, plasma chitotriosidase activity in all patients, and spleen and liver volumes (as well as bone marrow fat fraction images) in 10 patients. Decreases in platelet counts as a result of reduced treatment with imiglucerase were quickly restored on treatment with velaglucerase alfa. Chitotriosidase activity declined overall after switching. Five out of 10 patients had an increase in liver volume of at least 10% after six months of velaglucerase treatment, which was reversible in 3. Most patients received infusions at home and no important side effects were observed. Velaglucerase alfa appears to be a safe and effective alternative for imiglucerase.

Safe Direct Current Stimulator 2: Concept and Design

Fridman, Gene Y.; Della Santina, Charles C.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em //2013 EN
Relevância na Pesquisa
26.08%
Essentially all neuroprostheses use alternating biphasic current pulses to stimulate neural tissue. While this method can effectively excite neurons, it is not very effective for inhibiting them. In contrast, direct current (DC) can excite, inhibit, and modulate sensitivity of neurons. However, DC stimulation is biologically unsafe because it violates safe charge injection criteria. We have previously described the concept of a safe direct current stimulator (SDCS) that overcomes this constraint. The SDCS drives DC ionic current into the tissue by switching fluid valves in phase with biphasic current pulses delivered to the metal electrodes within the device. The original prototype of this device, SDCS1, could both suppress and excite the vestibular nerve with DC stimulation delivered by the device. In the process of building the SDCS1 we identified several problems that must be addressed to further develop this technology. Consequently, we designed the SDCS2, which eliminates periodic interruptions in stimulation current flow observed in the original SDCS1 design and is small enough for head-mounted use in chronic animal studies.

Safe Direct Current Stimulation to Expand Capabilities of Neural Prostheses

Fridman, Gene Y.; Della Santina, Charles C.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /03/2013 EN
Relevância na Pesquisa
26.08%
While effective in treating some neurological disorders, neuroelectric prostheses are fundamentally limited because they must employ charge-balanced stimuli to avoid evolution of irreversible electrochemical reactions and their byproducts at the interface between metal electrodes and body fluids. Charge-balancing is typically achieved by using brief biphasic alternating current (AC) pulses, which typically excite nearby neural tissues but cannot efficiently inhibit them. In contrast, direct current (DC) applied via a metal electrode in contact with body fluids can excite, inhibit and modulate sensitivity of neurons; however, DC stimulation is biologically unsafe because it violates “safe charge injection” limits that have long been considered unavoidable constraints. In this report, we describe the design and fabrication of a safe DC stimulator (SDCS) that overcomes this constraint. The SCDS drives DC ionic current into target tissue via salt-bridge micropipette electrodes by switching valves in phase with AC square waves applied to metal electrodes contained within the device. This approach achieves DC ionic flow through tissue while still adhering to charge-balancing constraints at each electrode-saline interface. We show the SDCS’s ability to both inhibit and excite neural activity to achieve improved dynamic range during prosthetic stimulation of the vestibular part of the inner ear in chinchillas.

Practical and clinical considerations in assessing patients with atrial fibrillation for switching to non-vitamin K antagonist oral anticoagulants in primary care

Guimarães, Patrícia O; Kaatz, Scott; Lopes, Renato D
Fonte: Dove Medical Press Publicador: Dove Medical Press
Tipo: Artigo de Revista Científica
Publicado em 07/09/2015 EN
Relevância na Pesquisa
25.84%
Atrial fibrillation (AF) is an important risk factor for thromboembolic events, and anticoagulation therapy can reduce this risk. Vitamin K antagonists (VKAs), such as warfarin, have been used for decades in patients with AF for stroke prevention. Currently, non-VKA oral anticoagulants (NOACs) are approved and available for non-valvular AF patients who are at increased risk of stroke. These agents are safe and effective and have important advantages over VKAs, such as significant reduction in intracranial hemorrhage and no need for routine laboratory monitoring. Thus, should all VKA-treated patients be switched to a NOAC? The aims of this article are: 1) to review the advantages of NOACs over VKAs; 2) to identify the group of patients who most benefit from receiving a NOAC and, therefore, are higher priority to be switched from VKAs; and 3) to provide clinical and practical guidance on how to switch patients safely from VKAs to NOACs.

Greening China’s Rural Energy : New Insights on the Potential of Smallholder Biogas

Christiaensen, Luc; Heltberg, Rasmus
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
EN_US
Relevância na Pesquisa
25.84%
Clean, safe energy for rural areas is an important component of green growth and sustainable development. Biogas could be an important contributor, if its record in reality lives up to its expected potential. This paper provides a preliminary assessment of biogas use by smallholder farmers in rural China, using data collected from 2,700 households in five provinces. The authors find that user satisfaction is high, and environmental and economic benefits appear tangible. There are strong indications of reduced use of wood and crop residues for fuel. Less time is spent on collecting fuel wood and cooking, which is especially beneficial to women. Adopters also save on fertilizers, because of the use of biogas residues. Moreover, problems with suspension of biogas use, whether due to technical or human factors, remained limited. However, few tangible benefits to respiratory health were detected. Overall, these findings are grounds for optimism about the potential for of smallholder biogas to contribute to more sustainable development...

A case of infliximab-induced lupus in a patient with ankylosing spondylitis: is it safe switch to another anti-TNF-α agent?

Santiago, T; Santiago, MG; Rovisco, J; Duarte, C; Malcata, A; Pereira da Silva, ja
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
Publicado em //2013 ENG
Relevância na Pesquisa
26.01%
Anti-TNF-α therapies are the latest class of medications found to be associated with drug-induced lupus, a distinctive entity known as anti-TNF-α-induced lupus (ATIL) (Williams et al., Rheumatology (Oxford) 48:716-20, 2009; De Rycke et al., Lupus 14:931-7, 2005; De Bandt et al., Clin Rheumatol 22:56-61, 2003). With the widespread use of these agents, it is likely that the incidence of ATIL will increase. The onset of ATIL in patients with rheumatoid arthritis and Crohn's disease has been described, but the literature regarding the occurrence of this entity in patients with ankylosing spondylitis (AS) is scarce (De Bandt et al., Clin Rheumatol 22:56-61, 2003; Ramos-Casals et al., Autoimmun Rev 9:188-93, 2010; Perez-Garcia et al., Rheumatology 45:114-116, 2006). To our knowledge, few reports of switching anti-TNF-α therapy after ATIL in AS have been reported (Akgül et al., Rheumatol Int, 2012). Therefore, it is not clear whether the development of ATIL should prohibit switch to another therapy, since patients may respond to another anti-TNF-α agent (Akgül et al., Rheumatol Int, 2012; Bodur et al., Rheumatol Int 29:451-454, 2009; Mounach et al., Clin Exp Rheumatol 26:1116-8, 2008; Williams and Cohen, Int J Dermatol 50:619-625, 2011; Ye et al....

Multiple model adaptive control with safe switching

Anderson, Brian; Brinsmead, Thomas; Liberzon, Daniel; Morse, A
Fonte: John Wiley & Sons Inc Publicador: John Wiley & Sons Inc
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
56.42%
The purpose of this paper is to marry the two concepts of multiple model adaptive control and safe adaptive control. In its simplest form, multiple model adaptive control involves a supervisor switching among one of a finite number of controllers as more

Markov switching negative binomial models: an application to vehicle accident frequencies

Malyshkina, Nataliya V.; Mannering, Fred L.; Tarko, Andrew P.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
26.15%
In this paper, two-state Markov switching models are proposed to study accident frequencies. These models assume that there are two unobserved states of roadway safety, and that roadway entities (roadway segments) can switch between these states over time. The states are distinct, in the sense that in the different states accident frequencies are generated by separate counting processes (by separate Poisson or negative binomial processes). To demonstrate the applicability of the approach presented herein, two-state Markov switching negative binomial models are estimated using five-year accident frequencies on Indiana interstate highway segments. Bayesian inference methods and Markov Chain Monte Carlo (MCMC) simulations are used for model estimation. The estimated Markov switching models result in a superior statistical fit relative to the standard (single-state) negative binomial model. It is found that the more frequent state is safer and it is correlated with better weather conditions. The less frequent state is found to be less safe and to be correlated with adverse weather conditions.; Comment: This is a preprint, the final paper is available on Accident Analysis and Prevention website (the preprint has 21 pages, 3 tables, 2 figures...

Non-minimal coupling in Higgs-Yukawa model with asymptotically safe gravity

Oda, Kin-ya; Yamada, Masatoshi
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
26.08%
We study the fixed point structure of the Higgs-Yukawa model, with its scalar being non-minimally coupled to the asymptotically safe gravity, using the functional renormalization group. We have obtained the renormalization group equations for the cosmological and Newton constants, the scalar mass-squared and quartic coupling constant, and the Yukawa and non-minimal coupling constants, taking into account all the scalar, fermion, and graviton loops. We find that switching on the fermionic quantum fluctuations makes the non-minimal coupling constant irrelevant around the Gaussian-matter fixed point with the asymptotically safe gravity.; Comment: 49 pages, 5 figures; Typos corrected in Eqs.(25), (58), and (145)

Promotion of well-switching to mitigate the current arsenic crisis in Bangladesh

van Geen,Alexander; Ahsan,Habibul; Horneman,Allan H.; Dhar,Ratan K.; Zheng,Yan; Hussain,Iftikhhar; Ahmed,Kazi Matin; Gelman,Andrew; Stute,Martin; Simpson,H. James; Wallace,Sean; Small,Christopher; Parvez,Faruque; Slavkovich,Vesna; LoIacono,Nancy J.; Becke
Fonte: World Health Organization Publicador: World Health Organization
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2002 EN
Relevância na Pesquisa
26.15%
OBJECTIVE: To survey tube wells and households in Araihazar upazila, Bangladesh, to set the stage for a long-term epidemiological study of the consequences of chronic arsenic exposure. METHODS: Water samples and household data were collected over a period of 4 months in 2000 from 4997 contiguous tube wells serving a population of 55 000, the position of each well being determined to within ± 30 m using Global Positioning System receivers. Arsenic concentrations were determined by graphite-furnace atomic-absorption spectrometry. In addition, groundwater samples collected every 2 weeks for an entire year from six tube wells were analysed for arsenic by high-resolution inductively coupled plasma-mass spectrometry. FINDINGS: Half of the wells surveyed in Araihazar had been installed in the previous 5 years; 94% were privately owned. Only about 48% of the surveyed wells supplied water with an arsenic content below 50 mug/l, the current Bangladesh standard for drinking-water. Similar to other regions of Bangladesh and West Bengal, India, the distribution of arsenic in Araihazar is spatially highly variable (range: 5-860 mug/l) and therefore difficult to predict. Because of this variability, however, close to 90% of the inhabitants live within 100 m of a safe well. Monitoring of six tube wells currently meeting the 50 mug/l standard showed no indication of a seasonal cycle in arsenic concentrations coupled to the hydrological cycle. This suggests that well-switching is a viable option in Araihazar...