From Agents to Continuous Change via Aesthetics: Learning Mechanics with Visual Agent-Based Computational Modeling

ERIC Educational Resources Information Center

Sengupta, Pratim; Farris, Amy Voss; Wright, Mason

2012-01-01

Novice learners find motion as a continuous process of change challenging to understand. In this paper, we present a pedagogical approach based on agent-based, visual programming to address this issue. Integrating agent-based programming, in particular, Logo programming, with curricular science has been shown to be challenging in previous research…

Agent Orange exposure and disease prevalence in Korean Vietnam veterans: the Korean veterans health study.

PubMed

Yi, Sang-Wook; Hong, Jae-Seok; Ohrr, Heechoul; Yi, Jee-Jeon

2014-08-01

Between 1961 and 1971, military herbicides were used by the United States and allied forces for military purposes. Agent Orange, the most-used herbicide, was a mixture of 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid, and contained an impurity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Many Korean Vietnam veterans were exposed to Agent Orange during the Vietnam War. The aim of this study was to evaluate the association between Agent Orange exposure and the prevalence of diseases of the endocrine, nervous, circulatory, respiratory, and digestive systems. The Agent Orange exposure was assessed by a geographic information system-based model. A total of 111,726 Korean Vietnam veterans were analyzed for prevalence using the Korea National Health Insurance claims data from January 2000 to September 2005. After adjusting for covariates, the high exposure group had modestly elevated odds ratios (ORs) for endocrine diseases combined and neurologic diseases combined. The adjusted ORs were significantly higher in the high exposure group than in the low exposure group for hypothyroidism (OR=1.13), autoimmune thyroiditis (OR=1.93), diabetes mellitus (OR=1.04), other endocrine gland disorders including pituitary gland disorders (OR=1.43), amyloidosis (OR=3.02), systemic atrophies affecting the nervous system including spinal muscular atrophy (OR=1.27), Alzheimer disease (OR=1.64), peripheral polyneuropathies (OR=1.09), angina pectoris (OR=1.04), stroke (OR=1.09), chronic obstructive pulmonary diseases (COPD) including chronic bronchitis (OR=1.05) and bronchiectasis (OR=1.16), asthma (OR=1.04), peptic ulcer (OR=1.03), and liver cirrhosis (OR=1.08). In conclusion, Agent Orange exposure increased the prevalence of endocrine disorders, especially in the thyroid and pituitary gland; various neurologic diseases; COPD; and liver cirrhosis. Overall, this study suggests that Agent Orange/2,4-D/TCDD exposure several decades earlier may increase morbidity

Effect of a Dispersant Agent in Fine Coal Recovery from Washery Tailings by Oil Agglomeration (Preliminary Study)

NASA Astrophysics Data System (ADS)

Yasar, Özüm; Uslu, Tuncay

2017-12-01

Among the fine coal cleaning methods, the oil agglomeration process has important advantages such as high process recovery, more clean product, simple dewatering stage. Several coal agglomeration studies have been undertaken recently and effects of different variables on the process performance have been investigated. However, unlike flotation studies, most of the previous agglomeration studies have not used dispersing agents to minimize slime coating effects of clays. In this study, agglomeration process was applied for recovery of fine coals from coal washery tailings containing remarkable amount of fine coal. Negative effect of fine clays during recovery was tried to be eliminated by using dispersing agent instead of de-sliming. Although ash reductions over 90 % were achieved, performance remained below expectations in terms of combustible matter recovery. However, this study is a preliminary one. It is considered that more satisfied results will be obtained in the next studies by changing the variables such as solid ratio, oil dosage, dispersant type and dosage.

Revised Study Design for Final Phase of the Change Agent Study. Study of Change Agent Programs: A Working Note.

ERIC Educational Resources Information Center

Bass, G.; And Others

The Rand change agent study was designed to determine the factors for successful implementation and continuation of selected federal programs--the Elementary and Secondary Education Act, Title III, Innovation Projects; ESEA Title VII, Bilingual Projects; Vocational Education Part D, Exemplary Programs; and the Right-to-Read program. This report…

Doxorubicin Delivery into Tumor Cells by Stable Cavitation without Contrast Agents.

PubMed

Chettab, Kamel; Mestas, Jean-Louis; Lafond, Maxime; Saadna, Djamel Eddine; Lafon, Cyril; Dumontet, Charles

2017-02-06

Doxorubicin, alone or in combination with other anticancer agents, is one of the most widely used chemotherapeutic agents and is administered in a wide range of cancers. However, the use of doxorubicin is limited due to its potential serious adverse reactions. Previous studies have established the ability of high intensity focused ultrasound (HIFU) in combination with various contrast agents to increase intracellular doxorubicin delivery in a targeted and noninvasive manner. In this study, we developed a new sonoporation device generating and monitoring acoustic cavitation bubbles without any addition of contrast agents. The device was used to potentiate the delivery of active doxorubicin into both adherent and suspended cell lines. Combining doxorubicin with ultrasound resulted in a significant enhancement of doxorubicin intracellular delivery and a decrease in cell viability at 48 and 72 h, in comparison to doxorubicin alone. More importantly and unlike previous investigations, our procedure does not require the addition of contrast agents to generate acoustic cavitation and to achieve high levels of doxorubicin delivery. The successful translation of this approach for an in vivo application may allow a significant reduction in the dosage and the adverse effects of doxorubicin therapy in patients.

40 CFR 152.93 - Citation of a previously submitted valid study.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Data Submitters' Rights § 152.93 Citation of a previously submitted valid study. An applicant may demonstrate compliance for a data requirement by citing a valid study previously submitted to the Agency. The... the original data submitter, the applicant may cite the study only in accordance with paragraphs (b...

Chemoprevention of colorectal cancer in individuals with previous colorectal neoplasia: systematic review and network meta-analysis

PubMed Central

Dulai, Parambir S; Marquez, Evelyn; Khera, Rohan; Prokop, Larry J; Limburg, Paul J; Gupta, Samir; Murad, Mohammad Hassan

2016-01-01

Objective To assess the comparative efficacy and safety of candidate agents (low and high dose aspirin, non-aspirin non-steroidal anti-inflammatory drugs (NSAIDs), calcium, vitamin D, folic acid, alone or in combination) for prevention of advanced metachronous neoplasia (that is, occurring at different times after resection of initial neoplasia) in individuals with previous colorectal neoplasia, through a systematic review and network meta-analysis. Data sources Medline, Embase, Web of Science, from inception to 15 October 2015; clinical trial registries. Study selection Randomized controlled trials in adults with previous colorectal neoplasia, treated with candidate chemoprevention agents, and compared with placebo or another candidate agent. Primary efficacy outcome was risk of advanced metachronous neoplasia; safety outcome was serious adverse events. Data extraction Two investigators identified studies and abstracted data. A Bayesian network meta-analysis was performed and relative ranking of agents was assessed with surface under the cumulative ranking (SUCRA) probabilities (ranging from 1, indicating that the treatment has a high likelihood to be best, to 0, indicating the treatment has a high likelihood to be worst). Quality of evidence was appraised with GRADE criteria. Results 15 randomized controlled trials (12 234 patients) comparing 10 different strategies were included. Compared with placebo, non-aspirin NSAIDs were ranked best for preventing advanced metachronous neoplasia (odds ratio 0.37, 95% credible interval 0.24 to 0.53; SUCRA=0.98; high quality evidence), followed by low-dose aspirin (0.71, 0.41 to 1.23; SUCRA=0.67; low quality evidence). Low dose aspirin, however, was ranked the safest among chemoprevention agents (0.78, 0.43 to 1.38; SUCRA=0.84), whereas non-aspirin NSAIDs (1.23, 0.95 to 1.64; SUCRA=0.26) were ranked low for safety. High dose aspirin was comparable with low dose aspirin in efficacy (1.12, 0.59 to 2.10; SUCRA=0.58) but

A decontamination study of simulated chemical and biological agents

NASA Astrophysics Data System (ADS)

Uhm, Han S.; Lee, Han Y.; Hong, Yong C.; Shin, Dong H.; Park, Yun H.; Hong, Yi F.; Lee, Chong K.

2007-07-01

A comprehensive decontamination scheme of the chemical and biological agents, including airborne agents and surface contaminating agents, is presented. When a chemical and biological attack occurs, it is critical to decontaminate facilities or equipments to an acceptable level in a very short time. The plasma flame presented here may provide a rapid and effective elimination of toxic substances in the interior air in isolated spaces. As an example, a reaction chamber, with the dimensions of a 22cm diameter and 30cm length, purifies air with an airflow rate of 5000l/min contaminated with toluene, the simulated chemical agent, and soot from a diesel engine, the simulated aerosol for biological agents. Although the airborne agents in an isolated space are eliminated to an acceptable level by the plasma flame, the decontamination of the chemical and biological agents cannot be completed without cleaning surfaces of the facilities. A simulated sterilization study of micro-organisms was carried out using the electrolyzed ozone water. The electrolyzed ozone water very effectively kills endospores of Bacillus atrophaeus (ATCC 9372) within 3min. The electrolyzed ozone water also kills the vegetative micro-organisms, fungi, and virus. The electrolyzed ozone water, after the decontamination process, disintegrates into ordinary water and oxygen without any trace of harmful materials to the environment.

[Prevalence of previously diagnosed diabetes mellitus in Mexico.

PubMed

Rojas-Martínez, Rosalba; Basto-Abreu, Ana; Aguilar-Salinas, Carlos A; Zárate-Rojas, Emiliano; Villalpando, Salvador; Barrientos-Gutiérrez, Tonatiuh

2018-01-01

To compare the prevalence of previously diagnosed diabetes in 2016 with previous national surveys and to describe treatment and its complications. Mexico's national surveys Ensa 2000, Ensanut 2006, 2012 and 2016 were used. For 2016, logistic regression models and measures of central tendency and dispersion were obtained. The prevalence of previously diagnosed diabetes in 2016 was 9.4%. The increase of 2.2% relative to 2012 was not significant and only observed in patients older than 60 years. While preventive measures have increased, the access to medical treatment and lifestyle has not changed. The treatment has been modified, with an increase in insulin and decrease in hypoglycaemic agents. Population aging, lack of screening actions and the increase in diabetes complications will lead to an increase on the burden of disease. Policy measures targeting primary and secondary prevention of diabetes are crucial.

Retention of Gadolinium-Based Contrast Agents in Multiple Sclerosis: Retrospective Analysis of an 18-Year Longitudinal Study.

PubMed

Forslin, Y; Shams, S; Hashim, F; Aspelin, P; Bergendal, G; Martola, J; Fredrikson, S; Kristoffersen-Wiberg, M; Granberg, T

2017-07-01

Gadolinium-based contrast agents have been associated with lasting high T1-weighted signal intensity in the dentate nucleus and globus pallidus, with histopathologically confirmed gadolinium retention. We aimed to longitudinally investigate the relationship of multiple gadolinium-based contrast agent administrations to the Signal Intensity Index in the dentate nucleus and globus pallidus and any associations with cognitive function in multiple sclerosis. The Signal Intensity Index in the dentate nucleus and globus pallidus was retrospectively evaluated on T1-weighted MR imaging in an 18-year longitudinal cohort study of 23 patients with MS receiving multiple gadolinium-based contrast agent administrations and 23 healthy age- and sex-matched controls. Participants also underwent comprehensive neuropsychological testing. Patients with MS had a higher Signal Intensity Index in the dentate nucleus ( P < .001), but not in the globus pallidus ( P = .19), compared with non-gadolinium-based contrast agent-exposed healthy controls by an unpaired t test. Increasing numbers of gadolinium-based contrast agent administrations were associated with an increased Signal Intensity Index in the dentate nucleus (β = 0.45, P < .001) and globus pallidus (β = 0.60, P < .001). This association remained stable with corrections for the age, disease duration, and physical disability for both the dentate nucleus (β = 0.43, P = .001) and globus pallidus (β = 0.58, P < .001). An increased Signal Intensity Index in the dentate nucleus among patients with MS was associated with lower verbal fluency scores, which remained significant after correction for several aspects of disease severity (β = -0.40 P = .013). Our data corroborate previous reports of lasting gadolinium retention in brain tissues. An increased Signal Intensity Index in the dentate nucleus and globus pallidus was associated with lower verbal fluency, which does not prove causality but encourages further studies on cognition

Rituximab, alkylating agents or combination therapy for gastric mucosa-associated lymphoid tissue lymphoma: a monocentric non-randomised observational study.

PubMed

Amiot, A; Lévy, M; Copie-Bergman, C; Dupuis, J; Szablewski, V; Le Baleur, Y; Baia, M; Belhadj, K; Sobhani, I; Leroy, K; Haioun, C; Delchier, J-C

2014-03-01

There is no consensus on the standard treatment of gastric mucosa-associated lymphoid tissue (MALT) lymphoma for Helicobacter pylori-negative patients and for patients with persistent disease despite H. pylori eradication. To evaluate the comparative efficacy and safety of alkylating agents and rituximab alone or in combination. In this monocentric retrospective study, which included 106 patients who had not been previously treated with anti-cancer agents, we evaluated the efficacy and safety of oral alkylating agents monotherapy (n = 48), rituximab monotherapy (n = 28) and the therapy combining both drugs (n = 30). Evaluations were performed at weeks 6 (W6), 25 (W25), and 52 (W52) and after 2 years (W104). After a median follow-up period of 4.9 years (range 0.4-17.2 years), complete remission and overall response were significantly higher in patients in the combination therapy group at W104 (92% and 100% respectively) compared with patients treated with alkylating agents alone (66% and 68%) and rituximab alone (64% and 73%). The 5-year progression-free survival probabilities were 68%, 70% and 89% in patients treated with alkylating agents alone, rituximab alone and combination therapy respectively. Haematological adverse events were reported in 32 (30%) patients (mostly grade 1) and were more frequent in the two groups receiving alkylating agents (P = 0.05 and P < 0.001). No toxicity-related death was reported. The use of anti-cancer systemic therapy is safe and efficient in gastric MALT lymphoma. In this retrospective study, the combination of rituximab plus chlorambucil seems more efficient than rituximab or alkylating agents alone. Rituximab has a better safety profile than regimens containing alkylating agents. © 2014 John Wiley & Sons Ltd.

Opportunistic Behavior in Motivated Learning Agents.

PubMed

Graham, James; Starzyk, Janusz A; Jachyra, Daniel

2015-08-01

This paper focuses on the novel motivated learning (ML) scheme and opportunistic behavior of an intelligent agent. It extends previously developed ML to opportunistic behavior in a multitask situation. Our paper describes the virtual world implementation of autonomous opportunistic agents learning in a dynamically changing environment, creating abstract goals, and taking advantage of arising opportunities to improve their performance. An opportunistic agent achieves better results than an agent based on ML only. It does so by minimizing the average value of all need signals rather than a dominating need. This paper applies to the design of autonomous embodied systems (robots) learning in real-time how to operate in a complex environment.

Studies of the transmissibility of the agent of bovine spongiform encephalopathy to the domestic chicken

PubMed Central

2011-01-01

Background Transmission of the prion disease bovine spongiform encephalopathy (BSE) occurred accidentally to cattle and several other mammalian species via feed supplemented with meat and bone meal contaminated with infected bovine tissue. Prior to United Kingdom controls in 1996 on the feeding of mammalian meat and bone meal to farmed animals, the domestic chicken was potentially exposed to feed contaminated with the causal agent of BSE. Although confirmed prion diseases are unrecorded in avian species a study was undertaken to transmit BSE to the domestic chicken by parenteral and oral inoculations. Transmissibility was assessed by clinical monitoring, histopathological examinations, detection of a putative disease form of an avian prion protein (PrP) in recipient tissues and by mouse bioassay of tissues. Occurrence of a progressive neurological syndrome in the primary transmission study was investigated by sub-passage experiments. Results No clinical, pathological or bioassay evidence of transmission of BSE to the chicken was obtained in the primary or sub-passage experiments. Survival data showed no significant differences between control and treatment groups. Neurological signs observed, not previously described in the domestic chicken, were not associated with significant pathology. The diagnostic techniques applied failed to detect a disease associated form of PrP. Conclusion Important from a risk assessment perspective, the present study has established that the domestic chicken does not develop a prion disease after large parenteral exposures to the BSE agent or after oral exposures equivalent to previous exposures via commercial diets. Future investigations into the potential susceptibility of avian species to mammalian prion diseases require species-specific immunochemical techniques and more refined experimental models. PMID:22093239

Desensitizing Agent Reduces Dentin Hypersensitivity During Ultrasonic Scaling: A Pilot Study.

PubMed

Suda, Tomonari; Kobayashi, Hiroaki; Akiyama, Toshiharu; Takano, Takuya; Gokyu, Misa; Sudo, Takeaki; Khemwong, Thatawee; Izumi, Yuichi

2015-09-01

Dentin hypersensitivity can interfere with optimal periodontal care by dentists and patients. The pain associated with dentin hypersensitivity during ultrasonic scaling is intolerable for patient and interferes with the procedure, particularly during supportive periodontal therapy (SPT) for patients with gingival recession. This study proposed to evaluate the desensitizing effect of the oxalic acid agent on pain caused by dentin hypersensitivity during ultrasonic scaling. This study involved 12 patients who were incorporated in SPT program and complained of dentin hypersensitivity during ultrasonic scaling. We examined the availability of the oxalic acid agent to compare the degree of pain during ultrasonic scaling with or without the application of the dentin hypersensitivity agent. Evaluation of effects on dentin hypersensitivity was determined by a questionnaire and visual analog scale (VAS) pain scores after ultrasonic scaling. The statistical analysis was performed using the paired Student t-test and Spearman rank correlation coefficient. The desensitizing agent reduced the mean VAS pain score from 69.33 ± 16.02 at baseline to 26.08 ± 27.99 after application. The questionnaire revealed that >80% patients were satisfied and requested the application of the desensitizing agent for future ultrasonic scaling sessions. This study shows that the application of the oxalic acid agent considerably reduces pain associated with dentin hypersensitivity experienced during ultrasonic scaling. This pain control treatment may improve patient participation and treatment efficiency.

A Systematic Review of the Effectiveness of Antianxiety and Antidepressive Agents for Functional Dyspepsia.

PubMed

Hojo, Mariko; Nagahara, Akihito; Asaoka, Daisuke; Shimada, Yuji; Sasaki, Hitoshi; Matsumoto, Kohei; Takeda, Tsutomu; Ueyama, Hiroya; Matsumoto, Kenshi; Watanabe, Sumio

2017-12-01

Objective Functional dyspepsia (FD) is defined as persistent or recurrent pain or discomfort centered in the upper abdomen without organic disease. Psychosocial factors have been proposed as an important element in the pathophysiology of FD. Therefore, psychotropic agents having antianxiety or antidepressive action are expected to alleviate FD. We previously reported on the treatment of FD using such agents in a systematic review, wherein the effectiveness of the agents on FD was suggested, although there were several limitations. We searched for articles on this subject after our systematic review and re-reviewed them systematically. Methods Articles were searched for in MEDLINE from 2003 to 2014 using terms related to antianxiety or antidepressive agents. Clinical studies in which the effectiveness of such agents was clearly stated were selected from the retrieved articles. The newly selected and previously selected studies were combined, and statistical analyses were carried out. Results Nine studies were selected. Five of the studies indicated a significant symptomatic improvement using psychotropic drugs. A statistical analysis suggested a significant treatment effect of psychotropic agents having antianxiety or antidepressive action [pooled relative risk (PRR), 0.72; 95% confidence interval (95% CI), 0.52-0.99; p=0.0406] but did not show a significant benefit of treatment with agents having an antidepressive action alone (PRR, 0.63; 95% CI, 0.38-1.03; p=0.0665). Conclusion Our systematic review suggested that psychotropic drugs having antianxiety and antidepressive actions as a whole might be effective in alleviating FD symptoms, whereas those having only antidepressive action were not effective.

A Systematic Review of the Effectiveness of Antianxiety and Antidepressive Agents for Functional Dyspepsia

PubMed Central

Hojo, Mariko; Nagahara, Akihito; Asaoka, Daisuke; Shimada, Yuji; Sasaki, Hitoshi; Matsumoto, Kohei; Takeda, Tsutomu; Ueyama, Hiroya; Matsumoto, Kenshi; Watanabe, Sumio

2017-01-01

Objective Functional dyspepsia (FD) is defined as persistent or recurrent pain or discomfort centered in the upper abdomen without organic disease. Psychosocial factors have been proposed as an important element in the pathophysiology of FD. Therefore, psychotropic agents having antianxiety or antidepressive action are expected to alleviate FD. We previously reported on the treatment of FD using such agents in a systematic review, wherein the effectiveness of the agents on FD was suggested, although there were several limitations. We searched for articles on this subject after our systematic review and re-reviewed them systematically. Methods Articles were searched for in MEDLINE from 2003 to 2014 using terms related to antianxiety or antidepressive agents. Clinical studies in which the effectiveness of such agents was clearly stated were selected from the retrieved articles. The newly selected and previously selected studies were combined, and statistical analyses were carried out. Results Nine studies were selected. Five of the studies indicated a significant symptomatic improvement using psychotropic drugs. A statistical analysis suggested a significant treatment effect of psychotropic agents having antianxiety or antidepressive action [pooled relative risk (PRR), 0.72; 95% confidence interval (95% CI), 0.52-0.99; p=0.0406] but did not show a significant benefit of treatment with agents having an antidepressive action alone (PRR, 0.63; 95% CI, 0.38-1.03; p=0.0665). Conclusion Our systematic review suggested that psychotropic drugs having antianxiety and antidepressive actions as a whole might be effective in alleviating FD symptoms, whereas those having only antidepressive action were not effective. PMID:29021437

Systemic use of tumor necrosis factor alpha as an anticancer agent

PubMed Central

Roberts, Nicholas J.; Zhou, Shibin; Diaz, Luis A.; Holdhoff, Matthias

2011-01-01

Tumor necrosis factor-α (TNF-α) has been discussed as a potential anticancer agent for many years, however initial enthusiasm about its clinical use as a systemic agent was curbed due to significant toxicities and lack of efficacy. Combination of TNF-α with chemotherapy in the setting of hyperthermic isolated limb perfusion (ILP), has provided new insights into a potential therapeutic role of this agent. The therapeutic benefit from TNF-α in ILP is thought to be not only due to its direct anti-proliferative effect, but also due to its ability to increase penetration of the chemotherapeutic agents into the tumor tissue. New concepts for the use of TNF-α as a facilitator rather than as a direct actor are currently being explored with the goal to exploit the ability of this agent to increase drug delivery and to simultaneously reduce systemic toxicity. This review article provides a comprehensive overview on the published previous experience with systemic TNF-α. Data from 18 phase I and 10 phase II single agent as well as 18 combination therapy studies illustrate previously used treatment and dose schedules, response data as well as the most prominently observed adverse effects. Also discussed, based on recent preclinical data, is a potential future role of systemic TNF-α in combination with liposomal chemotherapy to facilitate increased drug uptake into tumors. PMID:22036896

Desensitizing Agent Reduces Dentin Hypersensitivity During Ultrasonic Scaling: A Pilot Study

PubMed Central

Suda, Tomonari; Akiyama, Toshiharu; Takano, Takuya; Gokyu, Misa; Sudo, Takeaki; Khemwong, Thatawee; Izumi, Yuichi

2015-01-01

Background Dentin hypersensitivity can interfere with optimal periodontal care by dentists and patients. The pain associated with dentin hypersensitivity during ultrasonic scaling is intolerable for patient and interferes with the procedure, particularly during supportive periodontal therapy (SPT) for patients with gingival recession. Aim This study proposed to evaluate the desensitizing effect of the oxalic acid agent on pain caused by dentin hypersensitivity during ultrasonic scaling. Materials and Methods This study involved 12 patients who were incorporated in SPT program and complained of dentin hypersensitivity during ultrasonic scaling. We examined the availability of the oxalic acid agent to compare the degree of pain during ultrasonic scaling with or without the application of the dentin hypersensitivity agent. Evaluation of effects on dentin hypersensitivity was determined by a questionnaire and visual analog scale (VAS) pain scores after ultrasonic scaling. The statistical analysis was performed using the paired Student t-test and Spearman rank correlation coefficient. Results The desensitizing agent reduced the mean VAS pain score from 69.33 ± 16.02 at baseline to 26.08 ± 27.99 after application. The questionnaire revealed that >80% patients were satisfied and requested the application of the desensitizing agent for future ultrasonic scaling sessions. Conclusion This study shows that the application of the oxalic acid agent considerably reduces pain associated with dentin hypersensitivity experienced during ultrasonic scaling. This pain control treatment may improve patient participation and treatment efficiency. PMID:26501012

Illusory versus genuine control in agent-based games

NASA Astrophysics Data System (ADS)

Satinover, J. B.; Sornette, D.

2009-02-01

In the Minority, Majority and Dollar Games (MG, MAJG, G) agents compete for rewards, acting in accord with the previously best-performing of their strategies. Different aspects/kinds of real-world markets are modelled by these games. In the MG, agents compete for scarce resources; in the MAJG agents imitate the group to exploit a trend; in the G agents attempt to predict and benefit both from trends and changes in the direction of a market. It has been previously shown that in the MG for a reasonable number of preliminary time steps preceding equilibrium (Time Horizon MG, THMG), agents’ attempt to optimize their gains by active strategy selection is “illusory”: the hypothetical gains of their strategies is greater on average than agents’ actual average gains. Furthermore, if a small proportion of agents deliberately choose and act in accord with their seemingly worst performing strategy, these outperform all other agents on average, and even attain mean positive gain, otherwise rare for agents in the MG. This latter phenomenon raises the question as to how well the optimization procedure works in the THMAJG and THG. We demonstrate that the illusion of control is absent in THMAJG and THG. This provides further clarification of the kinds of situations subject to genuine control, and those not, in set-ups a priori defined to emphasize the importance of optimization.

Blaptica dubia as sentinels for exposure to chemical warfare agents - a pilot study.

PubMed

Worek, Franz; Seeger, Thomas; Neumaier, Katharina; Wille, Timo; Thiermann, Horst

2016-11-16

The increased interest of terrorist groups in toxic chemicals and chemical warfare agents presents a continuing threat to our societies. Early warning and detection is a key component for effective countermeasures against such deadly agents. Presently available and near term solutions have a number of major drawbacks, e.g. lack of automated, remote warning and detection of primarily low volatile chemical warfare agents. An alternative approach is the use of animals as sentinels for exposure to toxic chemicals. To overcome disadvantages of vertebrates the present pilot study was initiated to investigate the suitability of South American cockroaches (Blaptica dubia) as warning system for exposure to chemical warfare nerve and blister agents. Initial in vitro experiments with nerve agents showed an increasing inhibitory potency in the order tabun - cyclosarin - sarin - soman - VX of cockroach cholinesterase. Exposure of cockroaches to chemical warfare agents resulted in clearly visible and reproducible reactions, the onset being dependent on the agent and dose. With nerve agents the onset was related to the volatility of the agents. The blister agent lewisite induced signs largely comparable to those of nerve agents while sulfur mustard exposed animals exhibited a different sequence of events. In conclusion, this first pilot study indicates that Blaptica dubia could serve as a warning system to exposure of chemical warfare agents. A cockroach-based system will not detect or identify a particular chemical warfare agent but could trigger further actions, e.g. specific detection and increased protective status. By designing appropriate boxes with (IR) motion sensors and remote control (IR) camera automated off-site warning systems could be realized. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Incorporating BDI Agents into Human-Agent Decision Making Research

NASA Astrophysics Data System (ADS)

Kamphorst, Bart; van Wissen, Arlette; Dignum, Virginia

Artificial agents, people, institutes and societies all have the ability to make decisions. Decision making as a research area therefore involves a broad spectrum of sciences, ranging from Artificial Intelligence to economics to psychology. The Colored Trails (CT) framework is designed to aid researchers in all fields in examining decision making processes. It is developed both to study interaction between multiple actors (humans or software agents) in a dynamic environment, and to study and model the decision making of these actors. However, agents in the current implementation of CT lack the explanatory power to help understand the reasoning processes involved in decision making. The BDI paradigm that has been proposed in the agent research area to describe rational agents, enables the specification of agents that reason in abstract concepts such as beliefs, goals, plans and events. In this paper, we present CTAPL: an extension to CT that allows BDI software agents that are written in the practical agent programming language 2APL to reason about and interact with a CT environment.

Effect of Antithrombotic Agents on the Patency of PTFE-Covered Stents in the Inferior Vena Cava: An Experimental Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Makutani, Shiro; Kichikawa, Kimihiko; Uchida, Hideo

Purpose: To evaluate the efficacy of antithrombotic agents in the prevention of stenosis of polytetrafluoroethylene (PTFE)-covered stents in the venous system. Methods: Spiral Z stents covered with PTFE (PTFE-covered stents) were placed in the inferior vena cava (IVC) of 34 dogs. Nineteen dogs, used as a control group, were sacrificed at 2, 4, and 12 weeks. Fifteen dogs, previously given antithrombotic agents [cilostazol (n= 5), warfarin potassium (n= 5), cilostazol plus warfarin potassium (n= 5)] were sacrificed at 4 weeks, and then examined angiographically and histopathologically. The effect of the antithrombotic agents was compared between groups. Results: The patency ratemore » of the antithrombotic agent group was 93% (14/15), which was higher than the control group rate of 63% (12/19). The mean stenosis rate of the patent stent at both ends and at the midportion was lower at 4 weeks in the antithrombotic agent group than in the control group. In particular, the mean stenosis rate in the cilostazol plus warfarin potassium group was significantly lower than the control group (Tukey's test, p < 0.05). The mean neointimal thickness of the patent stent at both ends and at the midportion was thinner at 4 weeks in the antithrombotic agent group than in the control group. In particular, the thickness of the neointima in the cilostazol plus warfarin potassium group was significantly decreased when compared with the control group (Tukey's test p < 0.05). At 4 weeks, endothelialization in the antithrombotic agent group tended to be almost identical to that in the control group. Conclusion: The present study suggests that administration of an antithrombotic agent is an effective way of preventing the stenosis induced by a neointimal thickening of PTFE-covered stents in the venous system.« less

Embodied Agents, E-SQ and Stickiness: Improving Existing Cognitive and Affective Models

NASA Astrophysics Data System (ADS)

de Diesbach, Pablo Brice

This paper synthesizes results from two previous studies of embodied virtual agents on commercial websites. We analyze and criticize the proposed models and discuss the limits of the experimental findings. Results from other important research in the literature are integrated. We also integrate concepts from profound, more business-related, analysis that deepens on the mechanisms of rhetoric in marketing and communication, and the possible role of E-SQ in man-agent interaction. We finally suggest a refined model for the impacts of these agents on web site users, and limits of the improved model are commented.

Model of mobile agents for sexual interactions networks

NASA Astrophysics Data System (ADS)

González, M. C.; Lind, P. G.; Herrmann, H. J.

2006-02-01

We present a novel model to simulate real social networks of complex interactions, based in a system of colliding particles (agents). The network is build by keeping track of the collisions and evolves in time with correlations which emerge due to the mobility of the agents. Therefore, statistical features are a consequence only of local collisions among its individual agents. Agent dynamics is realized by an event-driven algorithm of collisions where energy is gained as opposed to physical systems which have dissipation. The model reproduces empirical data from networks of sexual interactions, not previously obtained with other approaches.

Spatiotemporal trends in the discovery of new swine infectious agents.

PubMed

Fournié, Guillaume; Kearsley-Fleet, Lianne; Otte, Joachim; Pfeiffer, Dirk Udo

2015-09-28

A literature review was conducted to assess the spatiotemporal trend and diversity of infectious agents that were newly found in pigs between 1985 and 2010. We identified 173 new variants from 91 species, of which 73 species had not been previously described in pigs. These new species, of which one third was zoonotic, were taxonomically diverse. They were identified throughout the study period, predominantly in the main pork producing countries, with the rate of discovery of new virus variants doubling within the last 10 years of the study period. Whilst infectious agent species newly detected in high-income countries were more likely to be associated with higher virulence, zoonotic agents prevailed in low- and middle-income countries. Although this trend is influenced by factors conditioning infectious agent detection - diagnostic methods, surveillance efforts, research interests -, it may suggest that different scales and types of production systems promote emergence of certain types of infectious agents. Considering the rapid transformation of the swine industry, concerted efforts are needed for improving our understanding of the factors influencing the emergence of infectious agents. This information then needs to inform the design of risk-based surveillance systems and strategies directly mitigating the risk associated with these factors.

Antihyperglycemic Agents Are Inversely Associated With Intracranial Aneurysm Rupture.

PubMed

Can, Anil; Castro, Victor M; Yu, Sheng; Dligach, Dmitriy; Finan, Sean; Gainer, Vivian S; Shadick, Nancy A; Savova, Guergana; Murphy, Shawn; Cai, Tianxi; Weiss, Scott T; Du, Rose

2018-01-01

Previous studies have suggested a protective effect of diabetes mellitus on aneurysmal subarachnoid hemorrhage risk. However, reports are inconsistent, and objective measures of hyperglycemia in these studies are lacking. Our aim was to investigate the association between aneurysmal subarachnoid hemorrhage and antihyperglycemic agent use and glycated hemoglobin levels. The medical records of 4701 patients with 6411 intracranial aneurysms, including 1201 prospective patients, diagnosed at the Massachusetts General Hospital and Brigham and Women's Hospital between 1990 and 2016 were reviewed and analyzed. Patients were separated into ruptured and nonruptured groups. Univariate and multivariate logistic regression analyses were performed to determine the association between aneurysmal subarachnoid hemorrhage and antihyperglycemic agents and glycated hemoglobin levels. Propensity score weighting was used to account for selection bias. In both unweighted and weighted multivariate analysis, antihyperglycemic agent use was inversely and significantly associated with ruptured aneurysms (unweighted odds ratio, 0.58; 95% confidence interval, 0.39-0.87; weighted odds ratio, 0.57; 95% confidence interval, 0.34-0.96). In contrast, glycated hemoglobin levels were not significantly associated with rupture status. Antihyperglycemic agent use rather than hyperglycemia is associated with decreased risk of aneurysmal subarachnoid hemorrhage, suggesting a possible protective effect of glucose-lowering agents in the pathogenesis of aneurysm rupture. © 2017 American Heart Association, Inc.

Academic and Nonacademic Validating Agents on Latinas Mathematics and Science Self Concept A Quantitative Study Utilizing the High School Longitudinal Study of 2009

NASA Astrophysics Data System (ADS)

Garza, Jennifer M.

The purpose of this study is to inform and further the discussion of academic (i.e. teachers and school counselors) and non-academic (i.e. parents, family, friends, etc.) validating agents on Latina students' mathematics and science self-concepts. This study found a relationship between Latina students' interactions with academic and non-academic validating agents and their math and science self-concept at the K-12 level. Through the review of the literature the researcher addresses identifiable factors and strategies that inform the field of education in the areas of validation theory, family characteristics, and access to STEM fields for Latina students. The researcher used an established instrument designed, administered, and validated through the National Center for Education Statistics (NCES). For purposes of this study, a categorical subset of participants who self-identified as being a Latina student was used. As a result, the total subset number in this study was N=1,882. To determine if academic and non-academic validating agents had an observable statistically significant relationship with Latina students' math and science self-concept, a series of one-way ANOVAs were calculated to compare differences in students' math and science self-concept based on academic and non-academic validating agents for the weighted sample of Latinas for the HLS:09 survey. A path analysis was also employed to assess the factors involved in Latina students' math and science self-concepts. The findings are consistent with previous research involving the influence that academic and non-academic validating agents have on the math and science self-concept of Latina students. The results indicated that students who had teachers that believed in the students, regardless of family background, social economic status or home environment influences had higher math and science self concepts than those who did not. Similarly, it was found that students who had counselors that set high

Agent-based modeling of the spread of the 1918-1919 flu in three Canadian fur trading communities.

PubMed

O'Neil, Caroline A; Sattenspiel, Lisa

2010-01-01

Previous attempts to study the 1918-1919 flu in three small communities in central Manitoba have used both three-community population-based and single-community agent-based models. These studies identified critical factors influencing epidemic spread, but they also left important questions unanswered. The objective of this project was to design a more realistic agent-based model that would overcome limitations of earlier models and provide new insights into these outstanding questions. The new model extends the previous agent-based model to three communities so that results can be compared to those from the population-based model. Sensitivity testing was conducted, and the new model was used to investigate the influence of seasonal settlement and mobility patterns, the geographic heterogeneity of the observed 1918-1919 epidemic in Manitoba, and other questions addressed previously. Results confirm outcomes from the population-based model that suggest that (a) social organization and mobility strongly influence the timing and severity of epidemics and (b) the impact of the epidemic would have been greater if it had arrived in the summer rather than the winter. New insights from the model suggest that the observed heterogeneity among communities in epidemic impact was not unusual and would have been the expected outcome given settlement structure and levels of interaction among communities. Application of an agent-based computer simulation has helped to better explain observed patterns of spread of the 1918-1919 flu epidemic in central Manitoba. Contrasts between agent-based and population-based models illustrate the advantages of agent-based models for the study of small populations. © 2010 Wiley-Liss, Inc.

Impact of novel agents on patient-relevant outcomes in patients with previously untreated chronic lymphocytic leukemia who are not eligible for fludarabine-based therapy.

PubMed

Singh, Moushmi; Mealing, Stuart; Baculea, Simona; Cote, Sarah; Whelan, Jo

2017-10-01

Chronic lymphocytic leukemia (CLL) is an orphan disease that primarily affects the elderly. The majority of symptomatic patients eligible for frontline treatment are unfit for fludarabine based chemoimmunotherapy. Historical treatment includes chlorambucil (Chl), bendamustine/rituximab (BR), and chlorambucil/rituximab/ChlR combination. Clinical guidelines now recommend the use of novel agents, such as ibrutinib (Ibr), in both frontline and relapse settings and other novel agents, such as idelalisib (with rituximab), in relapse settings. Despite compelling clinical results for novel agents, follow-up in clinical trials is relatively short and, thus, the comparative long-term benefits are still unknown. The authors developed a simulation model to generate treatment specific lifetime estimates of Overall Survival (OS) and Quality Adjusted Life Years (QALYs) for treatment with BR, Chl, ChlR, and Ibr. Two potential clinical scenarios were modelled: with and without novel agents for treating CLL. The model was based on health states relating to first- and second-line progression-free survival (PFS), post-progression survival, and death. Where novel agents were assumed unavailable, mean OS ranged from 5.4-8.5 years and QALYs from 3.5-6.1. Where novel agents were available, the mean OS increased to 10.0 years, with a corresponding increase in QALYs to 7.6. Frontline Ibr use followed by Physician's Choice, including novel agents at relapse, resulted in projected increase in OS of between 18% (1.5 years) and 85% (4.6 years), corresponding to a 25-117% increase in QALYs, compared with currently available traditional therapies. The limitations of this analysis include immature OS data and the assumption of equivalent efficacy across all novel agents in terms of their impact on PFS and OS. The use of novel agents is predicted to yield substantive gains in predicted lifetime OS and QALY improvements compared to traditional therapies in CLL patients who are ineligible for

X-ray spatial frequency heterodyne imaging of protein-based nanobubble contrast agents

PubMed Central

Rand, Danielle; Uchida, Masaki; Douglas, Trevor; Rose-Petruck, Christoph

2014-01-01

Spatial Frequency Heterodyne Imaging (SFHI) is a novel x-ray scatter imaging technique that utilizes nanoparticle contrast agents. The enhanced sensitivity of this new technique relative to traditional absorption-based x-ray radiography makes it promising for applications in biomedical and materials imaging. Although previous studies on SFHI have utilized only metal nanoparticle contrast agents, we show that nanomaterials with a much lower electron density are also suitable. We prepared protein-based “nanobubble” contrast agents that are comprised of protein cage architectures filled with gas. Results show that these nanobubbles provide contrast in SFHI comparable to that of gold nanoparticles of similar size. PMID:25321797

Optimal Wonderful Life Utility Functions in Multi-Agent Systems

NASA Technical Reports Server (NTRS)

Wolpert, David H.; Tumer, Kagan; Swanson, Keith (Technical Monitor)

2000-01-01

The mathematics of Collective Intelligence (COINs) is concerned with the design of multi-agent systems so as to optimize an overall global utility function when those systems lack centralized communication and control. Typically in COINs each agent runs a distinct Reinforcement Learning (RL) algorithm, so that much of the design problem reduces to how best to initialize/update each agent's private utility function, as far as the ensuing value of the global utility is concerned. Traditional team game solutions to this problem assign to each agent the global utility as its private utility function. In previous work we used the COIN framework to derive the alternative Wonderful Life Utility (WLU), and experimentally established that having the agents use it induces global utility performance up to orders of magnitude superior to that induced by use of the team game utility. The WLU has a free parameter (the clamping parameter) which we simply set to zero in that previous work. Here we derive the optimal value of the clamping parameter, and demonstrate experimentally that using that optimal value can result in significantly improved performance over that of clamping to zero, over and above the improvement beyond traditional approaches.

Agent Model Development for Assessing Climate-Induced Geopolitical Instability.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boslough, Mark B.; Backus, George A.

2005-12-01

We present the initial stages of development of new agent-based computational methods to generate and test hypotheses about linkages between environmental change and international instability. This report summarizes the first year's effort of an originally proposed three-year Laboratory Directed Research and Development (LDRD) project. The preliminary work focused on a set of simple agent-based models and benefited from lessons learned in previous related projects and case studies of human response to climate change and environmental scarcity. Our approach was to define a qualitative model using extremely simple cellular agent models akin to Lovelock's Daisyworld and Schelling's segregation model. Such modelsmore » do not require significant computing resources, and users can modify behavior rules to gain insights. One of the difficulties in agent-based modeling is finding the right balance between model simplicity and real-world representation. Our approach was to keep agent behaviors as simple as possible during the development stage (described herein) and to ground them with a realistic geospatial Earth system model in subsequent years. This work is directed toward incorporating projected climate data--including various C02 scenarios from the Intergovernmental Panel on Climate Change (IPCC) Third Assessment Report--and ultimately toward coupling a useful agent-based model to a general circulation model.3« less

Unsilencing Critical Conversations in Social-Studies Teacher Education Using Agent-Based Modeling

ERIC Educational Resources Information Center

Hostetler, Andrew; Sengupta, Pratim; Hollett, Ty

2018-01-01

In this article, we argue that when complex sociopolitical issues such as ethnocentrism and racial segregation are represented as complex, emergent systems using agent-based computational models (in short agent-based models or ABMs), discourse about these representations can disrupt social studies teacher candidates' dispositions of teaching…

Bidding Agents That Perpetrate Auction Fraud

NASA Astrophysics Data System (ADS)

Trevathan, Jarrod; McCabe, Alan; Read, Wayne

This paper presents a software bidding agent that inserts fake bids on the seller's behalf to inflate an auction's price. This behaviour is referred to as shill bidding. Shill bidding is strictly prohibited by online auctioneers, as it defrauds unsuspecting buyers by forcing them to pay more for the item. The malicious bidding agent was constructed to aid in developing shill detection techniques. We have previously documented a simple shill bidding agent that incrementally increases the auction price until it reaches the desired profit target, or it becomes too risky to continue bidding. This paper presents an adaptive shill bidding agent which when used over a series of auctions with substitutable items, can revise its strategy based on bidding behaviour in past auctions. The adaptive agent applies a novel prediction technique referred to as the Extremum Consistency (EC) algorithm, to determine the optimal price to aspire for. The EC algorithm has successfully been used in handwritten signature verification for determining the maximum and minimum values in an input stream. The agent's ability to inflate the price has been tested in a simulated marketplace and experimental results are presented.

Moral actor, selfish agent.

PubMed

Frimer, Jeremy A; Schaefer, Nicola K; Oakes, Harrison

2014-05-01

People are motivated to behave selfishly while appearing moral. This tension gives rise to 2 divergently motivated selves. The actor-the watched self-tends to be moral; the agent-the self as executor-tends to be selfish. Three studies present direct evidence of the actor's and agent's distinct motives. To recruit the self-as-actor, we asked people to rate the importance of various goals. To recruit the self-as-agent, we asked people to describe their goals verbally. In Study 1, actors claimed their goals were equally about helping the self and others (viz., moral); agents claimed their goals were primarily about helping the self (viz., selfish). This disparity was evident in both individualist and collectivist cultures, attesting to the universality of the selfish agent. Study 2 compared actors' and agents' motives to those of people role-playing highly prosocial or selfish exemplars. In content (Study 2a) and in the impressions they made on an outside observer (Study 2b), actors' motives were similar to those of the prosocial role-players, whereas agents' motives were similar to those of the selfish role-players. Study 3 accounted for the difference between the actor and agent: Participants claimed that their agent's motives were the more realistic and that their actor's motives were the more idealistic. The selfish agent/moral actor duality may account for why implicit and explicit measures of the same construct diverge, and why feeling watched brings out the better angels of human nature.

Reinforcement Learning Multi-Agent Modeling of Decision-Making Agents for the Study of Transboundary Surface Water Conflicts with Application to the Syr Darya River Basin

NASA Astrophysics Data System (ADS)

Riegels, N.; Siegfried, T.; Pereira Cardenal, S. J.; Jensen, R. A.; Bauer-Gottwein, P.

2008-12-01

In most economics--driven approaches to optimizing water use at the river basin scale, the system is modelled deterministically with the goal of maximizing overall benefits. However, actual operation and allocation decisions must be made under hydrologic and economic uncertainty. In addition, river basins often cross political boundaries, and different states may not be motivated to cooperate so as to maximize basin- scale benefits. Even within states, competing agents such as irrigation districts, municipal water agencies, and large industrial users may not have incentives to cooperate to realize efficiency gains identified in basin- level studies. More traditional simulation--optimization approaches assume pre-commitment by individual agents and stakeholders and unconditional compliance on each side. While this can help determine attainable gains and tradeoffs from efficient management, such hardwired policies do not account for dynamic feedback between agents themselves or between agents and their environments (e.g. due to climate change etc.). In reality however, we are dealing with an out-of-equilibrium multi-agent system, where there is neither global knowledge nor global control, but rather continuous strategic interaction between decision making agents. Based on the theory of stochastic games, we present a computational framework that allows for studying the dynamic feedback between decision--making agents themselves and an inherently uncertain environment in a spatially and temporally distributed manner. Agents with decision-making control over water allocation such as countries, irrigation districts, and municipalities are represented by reinforcement learning agents and coupled to a detailed hydrologic--economic model. This approach emphasizes learning by agents from their continuous interaction with other agents and the environment. It provides a convenient framework for the solution of the problem of dynamic decision-making in a mixed cooperative / non

Toxicity potential of disinfection agent in tannery wastewater.

PubMed

Tisler, Tatjana; Zagorc-Koncan, Jana; Cotman, Magda; Drolc, Andreja

2004-09-01

Wastewater from a tannery was investigated using chemical-specific analyses and assessment of the acute toxicity of the whole effluent over a 2-year period. The wastewater samples were overloaded with organic and inorganic compounds, and measured concentrations of the chemical parameters as well as dilution factors estimating acute toxicity, frequently exceeded the permissible limits for the discharge of wastewater from a tannery into the receiving stream. In the later part of the monitoring programme, the toxicity of the samples was significantly increased in comparison to the previous samples. The agent for hide disinfection was assumed to be the reason for the increased toxicity of the wastewater samples, and the extremely high acute and chronic toxicity of the agent to bacteria, algae, daphnids, and fish confirmed this suspicion. The most sensitive species was Daphnia magna; the 48 h EC50 was 0.70 x 10(-5)v/v% and the 21d IC25 was 0.40 x 10(-6)v/v% of the agent. After withdrawal of this highly toxic agent for hide disinfection from the technological process in the tannery, the toxicity of the wastewater declined to the previous level.

Development of Medical Technology for Contingency Response to Marrow Toxic Agents

DTIC Science & Technology

2014-01-31

Agents October 01, 2013 through December 31, 2013 11 of 20 o S1203: A Randomized Phase III Study of Standard Cytarabine plus Daunorubicin (7+3...Therapy or Idarubicin with High Dose Cytarabine (IA) versus IA with Vorinostat (IA+V) in Younger Patients with Previously Untreated Acute Myeloid

Agent-based simulation of a financial market

NASA Astrophysics Data System (ADS)

Raberto, Marco; Cincotti, Silvano; Focardi, Sergio M.; Marchesi, Michele

2001-10-01

This paper introduces an agent-based artificial financial market in which heterogeneous agents trade one single asset through a realistic trading mechanism for price formation. Agents are initially endowed with a finite amount of cash and a given finite portfolio of assets. There is no money-creation process; the total available cash is conserved in time. In each period, agents make random buy and sell decisions that are constrained by available resources, subject to clustering, and dependent on the volatility of previous periods. The model proposed herein is able to reproduce the leptokurtic shape of the probability density of log price returns and the clustering of volatility. Implemented using extreme programming and object-oriented technology, the simulator is a flexible computational experimental facility that can find applications in both academic and industrial research projects.

Ifosfamide and etoposide in previously treated patients with advanced breast cancer.

PubMed

Kiraz, S; Baltali, E; Güler, N; Barişta, I; Benekli, M; Celik, I; Güllü, I H; Kars, A; Tekuzman, G; Firat, D

1997-01-01

Ifosfamide is an active alkylating agent in the treatment of breast cancer, as a first-line therapy and in advanced disease. Since the combination of etoposide with an alkylating agent produces a synergistic and tolerable activity in various malignancies, in the present study, ifosfamide and etoposide were administered to patients with advanced breast cancer to evaluate the response characteristics and the toxicity profile. The combination of ifosfamide, mesna and etoposide was prospectively administered to 41 previously treated patients with stage IV breast carcinoma. The treatment schedule consisted of ifosfamide, 1500 mg/m2, infused over 24 hrs with 1500 mg/m2 mesna on days 1 to 5 and 120 mg/m2 etoposide, infused over 1 hr on days 1 to 3, to be repeated every 4th week. After a median follow-up of 10 months, an objective response rate of 23% (overall 2.5% complete remission and 20.5% partial remission) and a median response duration of 5.3 months were obtained in 39 assessable patients. The non-responder group consisted of 28.3% stable disease and 48.7% progressive disease. The prior status of chemotherapy was the only significant prognostic factor with an impact on the response rate. The overall toxicity was generally mild, with grade 3 myelotoxicity encountered in 25.7% of patients. The tolerable side effect profile of the ifosfamide and etoposide combination might be advantageous as regards the quality of life. To improve the rate and/or the duration of response and to clarify the precise role of the ifosfamide-etoposide combination in previously treated advanced breast cancer, further trials are warranted.

Contrast agent comparison for three-dimensional micro-CT angiography: A cadaveric study.

PubMed

Kingston, Mitchell J; Perriman, Diana M; Neeman, Teresa; Smith, Paul N; Webb, Alexandra L

2016-07-01

Barium sulfate and lead oxide contrast media are frequently used for cadaver-based angiography studies. These contrast media have not previously been compared to determine which is optimal for the visualisation and measurement of blood vessels. In this study, the lower limb vessels of 16 embalmed Wistar rats, and four sets of cannulae of known diameter, were injected with one of three different contrast agents (barium sulfate and resin, barium sulfate and gelatin, and lead oxide combined with milk powder). All were then scanned using micro-computed tomography (CT) angiography and 3-D reconstructions generated. The number of branching generations of the rat lower limb vessels were counted and compared between the contrast agents using ANOVA. The diameter of the contrast-filled cannulae, were measured and used to calculate the accuracy of the measurements by comparing the bias and variance of the estimates. Intra- and inter-observer reliability were calculated using intra-class correlation coefficients. There was no significant difference (mean difference [MD] 0.05; MD 95% confidence interval [CI] -0.83 to 0.93) between the number of branching generations for barium sulfate-resin and lead oxide-milk powder. Barium sulfate-resin demonstrated less bias and less variance of the estimates (MD 0.03; standard deviation [SD] 1.96 mm) compared to lead oxide-milk powder (MD 0.11; SD 1.96 mm) for measurements of contrast-filled cannulae scanned at high resolution. Barium sulfate-resin proved to be more accurate than lead oxide-milk powder for high resolution micro-CT scans and is preferred due to its non-toxicity. This technique could be applied to any embalmed specimen model. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Metareasoning and Social Evaluations in Cognitive Agents

NASA Astrophysics Data System (ADS)

Pinyol, Isaac; Sabater-Mir, Jordi

Reputation mechanisms have been recognized one of the key technologies when designing multi-agent systems. They are specially relevant in complex open environments, becoming a non-centralized mechanism to control interactions among agents. Cognitive agents tackling such complex societies must use reputation information not only for selecting partners to interact with, but also in metareasoning processes to change reasoning rules. This is the focus of this paper. We argue about the necessity to allow, as a cognitive systems designers, certain degree of freedom in the reasoning rules of the agents. We also describes cognitive approaches of agency that support this idea. Furthermore, taking as a base the computational reputation model Repage, and its integration in a BDI architecture, we use the previous ideas to specify metarules and processes to modify at run-time the reasoning paths of the agent. In concrete we propose a metarule to update the link between Repage and the belief base, and a metarule and a process to update an axiom incorporated in the belief logic of the agent. Regarding this last issue we also provide empirical results that show the evolution of agents that use it.

Forest Service special agent in charge report: nationwide study

Treesearch

Deborah J. Chavez; Joanne F. Tynon

2007-01-01

This study is the second in a series of studies to evaluate perceptions of USDA Forest Service law enforcement personnel of the roles, responsibilities, and issues entailed in their jobs. An e-mail survey was administered to the nine Forest Service special agents in charge (SACs) across the United States. All nine completed and returned the survey. Communication with...

Fairness emergence from zero-intelligence agents

NASA Astrophysics Data System (ADS)

Duan, Wen-Qi; Stanley, H. Eugene

2010-02-01

Fairness plays a key role in explaining the emergence and maintenance of cooperation. Opponent-oriented social utility models were often proposed to explain the origins of fairness preferences in which agents take into account not only their own outcomes but are also concerned with the outcomes of their opponents. Here, we propose a payoff-oriented mechanism in which agents update their beliefs only based on the payoff signals of the previous ultimatum game, regardless of the behaviors and outcomes of the opponents themselves. Employing adaptive ultimatum game, we show that (1) fairness behaviors can emerge out even under such minimalist assumptions, provided that agents are capable of responding to their payoff signals, (2) the average game payoff per agent per round decreases with the increasing discrepancy rate between the average giving rate and the average asking rate, and (3) the belief update process will lead to 50%-50% fair split provided that there is no mutation in the evolutionary dynamics.

Survival of dental implants placed in sites of previously failed implants.

PubMed

Chrcanovic, Bruno R; Kisch, Jenö; Albrektsson, Tomas; Wennerberg, Ann

2017-11-01

To assess the survival of dental implants placed in sites of previously failed implants and to explore the possible factors that might affect the outcome of this reimplantation procedure. Patients that had failed dental implants, which were replaced with the same implant type at the same site, were included. Descriptive statistics were used to describe the patients and implants; survival analysis was also performed. The effect of systemic, environmental, and local factors on the survival of the reoperated implants was evaluated. 175 of 10,096 implants in 98 patients were replaced by another implant at the same location (159, 14, and 2 implants at second, third, and fourth surgeries, respectively). Newly replaced implants were generally of similar diameter but of shorter length compared to the previously placed fixtures. A statistically significant greater percentage of lost implants were placed in sites with low bone quantity. There was a statistically significant difference (P = 0.032) in the survival rates between implants that were inserted for the first time (94%) and implants that replaced the ones lost (73%). There was a statistically higher failure rate of the reoperated implants for patients taking antidepressants and antithrombotic agents. Dental implants replacing failed implants had lower survival rates than the rates reported for the previous attempts of implant placement. It is suggested that a site-specific negative effect may possibly be associated with this phenomenon, as well as the intake of antidepressants and antithrombotic agents. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A study on etiologic agents and clinical manifestations of dermatophytosis in Yazd, Iran

PubMed Central

Rashidian, S; Falahati, M; Kordbacheh, P; Mahmoudi, M; Safara, M; Sadeghi Tafti, H; Mahmoudi, S; Zaini, F

2015-01-01

Background and Purpose: Dermatophytosis is one of the most common infections of skin, hair, and nails, caused by a group of keratinophilic fungi known as dermatophytes. Species identification of these fungi is of great significance from epidemiological and therapeutic points of view. The objective of the present study was to investigate dermatophytosis and its causative agents in patients, referring to the Central Mycology Laboratory of Yazd University of Medical Sciences, Yazd, Iran. Materials and Methods: In total, 139 clinically suspected cases of dermatophytosis were examined during 12 months from February 2014 to February 2015. Skin scrapings were assessed through direct microscopic examinations and culture studies. Dermatophyte isolates were identified based on colony morphology on potato dextrose agar and dermatophyte test medium, nutritional requirements, urease and hair perforation tests, and microscopic characteristics on slide cultures. Results: Dermatophytosis was mycologically confirmed in 26 (18.70%) out of 139 cases. Although there was a statistically insignificant difference between male and female subjects, men were dominantly affected. Infection was significantly common in the age group of ≤ 29 years (P<0.043). The most common clinical manifestation of dermatophytosis was tinea corporis (69.2%), followed by tinea cruris (15.4%), tinea manuum (11.5%), and tinea pedis (3.8%). Trichophyton mentagrophytes complex was the main etiologic agent (38.5%), followed by T. rubrum (23%), T. violaceum (15.5%), T. verrucosum (11.5%), Microsporum canis (7.7%), and Epidermophyton floccosum (3.8%). Conclusion: In comparison with previous research, epidemiology of dermatophytosis has changed in Yazd over the past decades. Therefore, periodical investigations on the epidemiological aspects of this infection are required for efficient control and prevention of this cutaneous dermatophytic disease. PMID:28681000

Matched cohort study of external cephalic version in women with previous cesarean delivery.

PubMed

Keepanasseril, Anish; Anand, Keerthana; Soundara Raghavan, Subrahmanian

2017-07-01

To evaluate the efficacy and safety of external cephalic version (ECV) among women with previous cesarean delivery. A retrospective study was conducted using data for women with previous cesarean delivery and breech presentation who underwent ECV at or after 36 weeks of pregnancy during 2011-2016. For every case, two multiparous women without previous cesarean delivery who underwent ECV and were matched for age and pregnancy duration were included. Characteristics and outcomes were compared between groups. ECV was successful for 32 (84.2%) of 38 women with previous cesarean delivery and 62 (81.6%) in the control group (P=0.728). Multivariate regression analysis confirmed that previous cesarean was not associated with ECV success (odds ratio 1.89, 95% confidence interval 0.19-18.47; P=0.244). Successful vaginal delivery after successful ECV was reported for 19 (59.4%) women in the previous cesarean delivery group and 52 (83.9%) in the control group (P<0.001). No ECV-associated complications occurred in women with previous cesarean delivery. To avoid a repeat cesarean delivery, ECV can be offered to women with breech presentation and previous cesarean delivery who are otherwise eligible for a trial of labor. © 2017 International Federation of Gynecology and Obstetrics.

The effects of hemostatic agents on peripheral nerve function: an experimental study.

PubMed

Alkan, Alper; Inal, Samet; Yildirim, Mehmet; Baş, Burcu; Ağar, Erdal

2007-04-01

In the practice of oral and maxillofacial surgery, hemostatic agents are sometimes placed in close proximity to peripheral nerves. In the present study, we evaluated immediate and delayed effects of 4 hemostatic agents (oxidized regenerated cellulose, 5% colloid silver-added gelatine sponge, bovine collagen, bone wax) on peripheral nerve function. A total of 25 rat sciatic nerves were prepared, and the amplitudes were recorded with a physiological data acquisition system. Animals were randomly assigned to 5 groups: control, oxidized regenerated cellulose, gelatine sponge, bone wax, and bovine collagen. The first hour records are defined as immediate effects of these hemostatic agents on nerve function. The animals were then allowed to recover for 4 weeks. At the end of this period, the same surgical and recording procedures were performed. These final records are defined as delayed effects of hemostatic agents on nerve function. According to nerve conduction velocity (NCV) and compound action potential (CAP) values of the experimental groups, early and delayed effects of each hemostatic agent were statistically compared with Bonferroni corrected test (P < .05). Statistically, NCV was significantly reduced, and the CAP was significantly increased 1 hour after surgery (P < .05) in the group of oxidized regenerated cellulose. However, there were no significant differences after 4 weeks compared with the first records. In the gelatine sponge group, CAP was significantly increased 4 weeks after the application. In the bovine collagen and bone wax groups, NCV and CAP values (1 hour and 4 weeks after the application) were not statistically significant compared with initial control records. The present study shows that bovine collagen is the most suitable hemostatic agent applicable for peripheral nerves.

Ultrasensitive detection of explosives and chemical warfare agents by low-pressure photoionization mass spectrometry.

PubMed

Sun, Wanqi; Liang, Miao; Li, Zhen; Shu, Jinian; Yang, Bo; Xu, Ce; Zou, Yao

2016-08-15

On-spot monitoring of threat agents needs high sensitive instrument. In this study, a low-pressure photoionization mass spectrometer (LPPI-MS) was employed to detect trace amounts of vapor-phase explosives and chemical warfare agent mimetics under ambient conditions. Under 10-s detection time, the limits of detection of 2,4-dinitrotoluene, nitrotoluene, nitrobenzene, and dimethyl methyl phosphonate were 30, 0.5, 4, and 1 parts per trillion by volume, respectively. As compared to those obtained previously with PI mass spectrometric techniques, an improvement of 3-4 orders of magnitude was achieved. This study indicates that LPPI-MS will open new opportunities for the sensitive detection of explosives and chemical warfare agents. Copyright © 2016 Elsevier B.V. All rights reserved.

New rodent models for studies of chemopreventive agents.

PubMed

Lipkin, M

1997-01-01

Some recent studies of the effects of chemopreventive agents have begun to use new rodent models to improve the analysis of stages of colonic preneoplasia, and how chemopreventive agents modify progressive abnormal cell development. In one of the models of inherited predisposition to colon cancer, mice carrying a truncated Apc allele with a nonsense mutation in exon 15 have been generated by gene targeting and embryonic stem cell technology (Apc1638 mice). These mice develop multiple gastrointestinal lesions, including adenomas and carcinomas, focal areas of high-grade dysplasia (FAD), and polypoid hyperplasias with FADS. The incidence of inherited colonic neoplasms has now been modulated by a chemopreventive regimen. Colonic lesions significantly increased in Apc1638 mice on a Western-style diet, which has higher fat content and lower calcium and vitamin D compared to the same mice on AIN-76A diet. In another rodent model, Min mice were treated with sulindac, which markedly reduced the incidence of intestinal tumors. A third new rodent model containing a targeted mutation in the gene Mcc (mutated in colorectal cancer) recently became available for chemoprevention studies. These mice develop multiple types of neoplasms including adenocarcinomas, focal areas of gastrointestinal dysplasia, papillomas of the forestomach, and tumors in other organs including lung, liver, and lymphoid tissue. Feeding a Western-style diet to the Mcc mutant mice also resulted in significantly increased gastrointestinal lesions. These nutrient modifications also have been given to normal mice, demonstrating without any chemical carcinogen that a Western-style diet induced colonic tumorigenesis. Western-style diets also have now induced modulation of cell proliferation in other organs including mammary gland, pancreas, and prostate. These findings help develop new preclinical rodent models to aid the analysis of genetic and environmental factors leading to neoplasia, as well as new methods

Assessment of antibacterial properties of newer dentin bonding agents: An in vitro study.

PubMed

Sampath, Pavitra B; Hegde, Mithra N; Hegde, Priyadarshini

2011-07-01

To evaluate and compare the antibacterial activity of newer dentin bonding agents on Streptococcus mutans using the direct contact test. Streptococcus mutans was used as test organism and a direct contact test was performed. The dentin bonding agents to be tested were grouped as Group I, Clearfil Protect Bond, Group II, Adper Easy One, and Group III, Prime and Bond NT. For the direct contact test, three microtiter plates consisting of 96 wells each were taken (288 wells). These wells were divided into three groups of 96 wells; 16 wells of a microtiter plate were utilized, of which four were designated as 'A' wells (with the dentin bonding agent and bacterial suspension), another four as 'B' wells (without the dentin bonding agent, but with the bacterial suspension), another four as the 'C' wells (with the tested material, but without bacteria, which served as the negative control), and the remaining four as the 'D' wells (without the dentin bonding agent, which served as the positive control). Each group was treated with their respective bonding agents as per the manufactures instructions. Broth of 15 μL was then transferred from the A wells into an adjacent set of B wells containing fresh medium (215 μL). This resulted in two sets of four wells for each tested material containing an equal volume of liquid medium, so that bacterial growth was monitored both in the presence and in the absence of the tested material. The plate was placed for incubation at 37°C in the microplate reader and the optical density in each well was measured at 600 nm. The readings were taken at regular intervals. (Every 30 minutes for 16 hours). The Dentin bonding agents evaluated in this study showed different inhibitory effects. Clearfil Protect Bond and Prime and Bond NT were most effective, and Adper Easy One was least effective against Streptococcus mutans. The Dentin bonding agents evaluated in this study showed different inhibitory effects. Clearfil Protect Bond and Prime and Bond

Anesthetic agent-specific effects on synaptic inhibition.

PubMed

MacIver, M Bruce

2014-09-01

Anesthetics enhance γ-aminobutyric acid (GABA)-mediated inhibition in the central nervous system. Different agents have been shown to act on tonic versus synaptic GABA receptors to different degrees, but it remains unknown whether different forms of synaptic inhibition are also differentially engaged. With this in mind, we tested the hypothesis that different types of GABA-mediated synapses exhibit different anesthetic sensitivities. The present study compared effects produced by isoflurane, halothane, pentobarbital, thiopental, and propofol on paired-pulse GABAA receptor-mediated synaptic inhibition. Effects on glutamate-mediated facilitation were also studied. Synaptic responses were measured in rat hippocampal brain slices. Orthodromic paired-pulse stimulation was used to assess anesthetic effects on either glutamate-mediated excitatory inputs or GABA-mediated inhibitory inputs to CA1 neurons. Antidromic stimulation was used to assess anesthetic effects on CA1 background excitability. Agents were studied at equieffective concentrations for population spike depression to compare their relative degree of effect on synaptic inhibition. Differing degrees of anesthetic effect on paired-pulse facilitation at excitatory glutamate synapses were evident, and blocking GABA inhibition revealed a previously unseen presynaptic action for pentobarbital. Although all 5 anesthetics depressed synaptically evoked excitation of CA1 neurons, the involvement of enhanced GABA-mediated inhibition differed considerably among agents. Single-pulse inhibition was enhanced by propofol, thiopental, and pentobarbital, but only marginally by halothane and isoflurane. In contrast, isoflurane enhanced paired-pulse inhibition strongly, as did thiopental, but propofol, pentobarbital, and halothane were less effective. These observations support the idea that different GABA synapses use receptors with differing subunit compositions and that anesthetics exhibit differing degrees of selectivity for

Marine Mollusk‐Derived Agents with Antiproliferative Activity as Promising Anticancer Agents to Overcome Chemotherapy Resistance

PubMed Central

Lefranc, Florence; Carbone, Marianna; Mollo, Ernesto; Gavagnin, Margherita; Betancourt, Tania; Dasari, Ramesh

2016-01-01

Abstract The chemical investigation of marine mollusks has led to the isolation of a wide variety of bioactive metabolites, which evolved in marine organisms as favorable adaptations to survive in different environments. Most of them are derived from food sources, but they can be also biosynthesized de novo by the mollusks themselves, or produced by symbionts. Consequently, the isolated compounds cannot be strictly considered as “chemotaxonomic markers” for the different molluscan species. However, the chemical investigation of this phylum has provided many compounds of interest as potential anticancer drugs that assume particular importance in the light of the growing literature on cancer biology and chemotherapy. The current review highlights the diversity of chemical structures, mechanisms of action, and, most importantly, the potential of mollusk‐derived metabolites as anticancer agents, including those biosynthesized by mollusks and those of dietary origin. After the discussion of dolastatins and kahalalides, compounds previously studied in clinical trials, the review covers potentially promising anticancer agents, which are grouped based on their structural type and include terpenes, steroids, peptides, polyketides and nitrogen‐containing compounds. The “promise” of a mollusk‐derived natural product as an anticancer agent is evaluated on the basis of its ability to target biological characteristics of cancer cells responsible for poor treatment outcomes. These characteristics include high antiproliferative potency against cancer cells in vitro, preferential inhibition of the proliferation of cancer cells over normal ones, mechanism of action via nonapoptotic signaling pathways, circumvention of multidrug resistance phenotype, and high activity in vivo, among others. The review also includes sections on the targeted delivery of mollusk‐derived anticancer agents and solutions to their procurement in quantity. PMID:27925266

An agent-based simulation model to study accountable care organizations.

PubMed

Liu, Pai; Wu, Shinyi

2016-03-01

Creating accountable care organizations (ACOs) has been widely discussed as a strategy to control rapidly rising healthcare costs and improve quality of care; however, building an effective ACO is a complex process involving multiple stakeholders (payers, providers, patients) with their own interests. Also, implementation of an ACO is costly in terms of time and money. Immature design could cause safety hazards. Therefore, there is a need for analytical model-based decision-support tools that can predict the outcomes of different strategies to facilitate ACO design and implementation. In this study, an agent-based simulation model was developed to study ACOs that considers payers, healthcare providers, and patients as agents under the shared saving payment model of care for congestive heart failure (CHF), one of the most expensive causes of sometimes preventable hospitalizations. The agent-based simulation model has identified the critical determinants for the payment model design that can motivate provider behavior changes to achieve maximum financial and quality outcomes of an ACO. The results show nonlinear provider behavior change patterns corresponding to changes in payment model designs. The outcomes vary by providers with different quality or financial priorities, and are most sensitive to the cost-effectiveness of CHF interventions that an ACO implements. This study demonstrates an increasingly important method to construct a healthcare system analytics model that can help inform health policy and healthcare management decisions. The study also points out that the likely success of an ACO is interdependent with payment model design, provider characteristics, and cost and effectiveness of healthcare interventions.

DYNACLIPS (DYNAmic CLIPS): A dynamic knowledge exchange tool for intelligent agents

NASA Technical Reports Server (NTRS)

Cengeloglu, Yilmaz; Khajenoori, Soheil; Linton, Darrell

1994-01-01

In a dynamic environment, intelligent agents must be responsive to unanticipated conditions. When such conditions occur, an intelligent agent may have to stop a previously planned and scheduled course of actions and replan, reschedule, start new activities and initiate a new problem solving process to successfully respond to the new conditions. Problems occur when an intelligent agent does not have enough knowledge to properly respond to the new situation. DYNACLIPS is an implementation of a framework for dynamic knowledge exchange among intelligent agents. Each intelligent agent is a CLIPS shell and runs a separate process under SunOS operating system. Intelligent agents can exchange facts, rules, and CLIPS commands at run time. Knowledge exchange among intelligent agents at run times does not effect execution of either sender and receiver intelligent agent. Intelligent agents can keep the knowledge temporarily or permanently. In other words, knowledge exchange among intelligent agents would allow for a form of learning to be accomplished.

Review of CO₂ as a Euthanasia Agent for Laboratory Rats and Mice.

PubMed

Boivin, Gregory P; Hickman, Debra L; Creamer-Hente, Michelle A; Pritchett-Corning, Kathleen R; Bratcher, Natalie A

2017-09-01

Selecting an appropriate, effective euthanasia agent is controversial. Several recent publications provide clarity on the use of CO2 in laboratory rats and mice. This review examines previous studies on CO2 euthanasia and presents the current body of knowledge on the subject. Potential areas for further investigation and recommendations are provided.

Lossed in translation: an off-the-shelf method to recover probabilistic beliefs from loss-averse agents.

PubMed

Offerman, Theo; Palley, Asa B

2016-01-01

Strictly proper scoring rules are designed to truthfully elicit subjective probabilistic beliefs from risk neutral agents. Previous experimental studies have identified two problems with this method: (i) risk aversion causes agents to bias their reports toward the probability of [Formula: see text], and (ii) for moderate beliefs agents simply report [Formula: see text]. Applying a prospect theory model of risk preferences, we show that loss aversion can explain both of these behavioral phenomena. Using the insights of this model, we develop a simple off-the-shelf probability assessment mechanism that encourages loss-averse agents to report true beliefs. In an experiment, we demonstrate the effectiveness of this modification in both eliminating uninformative reports and eliciting true probabilistic beliefs.

An agent-based computational model for tuberculosis spreading on age-structured populations

NASA Astrophysics Data System (ADS)

Graciani Rodrigues, C. C.; Espíndola, Aquino L.; Penna, T. J. P.

2015-06-01

In this work we present an agent-based computational model to study the spreading of the tuberculosis (TB) disease on age-structured populations. The model proposed is a merge of two previous models: an agent-based computational model for the spreading of tuberculosis and a bit-string model for biological aging. The combination of TB with the population aging, reproduces the coexistence of health states, as seen in real populations. In addition, the universal exponential behavior of mortalities curves is still preserved. Finally, the population distribution as function of age shows the prevalence of TB mostly in elders, for high efficacy treatments.

Cosmetic Preservatives as Therapeutic Corneal and Scleral Tissue Cross-Linking Agents

PubMed Central

Babar, Natasha; Kim, MiJung; Cao, Kerry; Shimizu, Yukari; Kim, Su-Young; Takaoka, Anna; Trokel, Stephen L.; Paik, David C.

2015-01-01

Purpose. Previously, aliphatic β-nitroalcohols (BNAs) have been studied as a means to chemically induce tissue cross-linking (TXL) of cornea and sclera. There are a number of related and possibly more potent agents, known as formaldehyde releasers (FARs), that are in commercial use as preservatives in cosmetics and other personal care products. The present study was undertaken in order to screen such compounds for potential clinical utility as therapeutic TXL agents. Methods. A chemical registry of 62 FARs was created from a literature review and included characteristics relevant to TXL such as molecular weight, carcinogenicity/mutagenicity, toxicity, hydrophobicity, and commercial availability. From this registry, five compounds [diazolidinyl urea (DAU), imidazolidinyl urea (IMU), sodium hydroxymethylglycinate (SMG), DMDM hydantoin (DMDM), 5-Ethyl-3,7-dioxa-1-azabicyclo [3.3.0] octane (OCT)] were selected for efficacy screening using two independent systems, an ex vivo rabbit corneal cross-linking simulation setup and incubation of cut scleral tissue pieces. Treatments were conducted at pH 7.4 or 8.5 for 30 minutes. Efficacy was evaluated using thermal denaturation temperature (Tm), and cell toxicity was studied using the trypan blue exclusion method. Results. Cross-linking effects in the five selected FARs were pH and concentration dependent. Overall, the Tm shifts were in agreement with both cornea and sclera. By comparison with BNAs previously reported upon, the FARs identified in this study were significantly more potent but with similar or better cytotoxicity. Conclusions. The FARs, a class of compounds well known to the cosmetic industry, may have utility as therapeutic TXL agents. The compounds studied thus far show promise and will be further tested. PMID:25634979

Agent-based model for rural-urban migration: A dynamic consideration

NASA Astrophysics Data System (ADS)

Cai, Ning; Ma, Hai-Ying; Khan, M. Junaid

2015-10-01

This paper develops a dynamic agent-based model for rural-urban migration, based on the previous relevant works. The model conforms to the typical dynamic linear multi-agent systems model concerned extensively in systems science, in which the communication network is formulated as a digraph. Simulations reveal that consensus of certain variable could be harmful to the overall stability and should be avoided.

Alkali Burn of the Ocular Surface Associated With a Commonly Used Antifog Agent for Eyewear: Two Cases and a Review of Previous Reports.

PubMed

Welling, John D; Pike, Evan C; Mauger, Thomas F

2016-02-01

To report 2 cases of ocular chemical burns associated with the use of a swim goggle antifog agent and to review the literature for this and similar antifog products. Case reports and systematic review of the medical literature, material safety data, product safety reports, and consumer reviews. Two males, one 46 years and the other 41 years, were referred to our clinic with chemical burns of the ocular surface after using the same goggle antifog agent while swimming in a triathlon. Both sustained significant epithelial defects. Fortunately, with prompt treatment, both of our patients returned to their baseline vision within a few weeks without suffering sight-threatening complications. These are the first cases of ocular chemical burn secondary to use of an eyewear antifog agent to be reported in the medical literature. Similar reports found in consumer forums suggest that our cases are not isolated and these products may have the potential to cause vision-threatening chemical burns.

Serological studies on the infection of dogs in Ontario with Borrelia burgdorferi, the etiological agent of Lyme disease

PubMed Central

Artsob, Harvey; Barker, Ian K.; Fister, Richard; Sephton, Gregory; Dick, Daryl; Lynch, John A.; Key, Doug

1993-01-01

A serological study was undertaken to determine whether dogs in Ontario are being exposed to Borrelia burgdorferi, the etiological agent of Lyme disease. This study consisted of a survey of randomly selected dogs and testing of diagnostic submissions from candidate Lyme disease cases. The survey of 1,095 dogs, bled between January 1988 and August 1989, revealed a total of 65 (5.9%) enzyme-linked immunosorbent assay (ELISA) reactors, of which 22 had immuno-fluorescent antibody assay (IFA) titers ≥1:32. All but one of the IFA-positive and 10 of the ELISA-positive, IFA-negative sera were further tested by western blot. Eight western blot positive and three equivocal reactors were obtained. Three of the eight confirmed reactors had visited areas known to be endemic for Lyme disease, leaving five reactors that might have been infected in previously undocumented areas for B. burgdorferi activity in Ontario. Diagnostic submissions of sera from 223 dogs were received between August 1987 and February 1992. Test results revealed 21 (9.4%) IFA reactors, of which only six had significant titers (≥1:256) and were reactive by an immunodot Borrelia test. All six dogs had travelled to known Lyme endemic areas. Based on results obtained from this study, it seems likely that the agent of Lyme disease is not widespread in Ontario. PMID:17424284

Hydrolysis of Nerve Agents by Model Nucleophiles: A Computational Study

PubMed Central

Beck, Jeremy M.

2008-01-01

Density functional theory calculations were employed to study the reaction of five nerve agents with model nucleophiles, including EtX− and EtXH (X = O, S, Se) for serine, cysteine and selenocysteine, respectively. Calculations at the B3LYP/6-311++G(2d,p) level of theory predict an exothermic reaction between ethoxide and all of the nerve agents studied. As compared to EtO− as a nucleophile, these reactions become ~30 kcal/mol more endothermic for EtS−, and by ~40 kcal/mol for EtSe−. The equivalent reactions with the neutral nucleophiles (EtXH) were more endothermic. The effect of solvation on the reaction thermochemistry was determined using a polarizable continuum model simulating the dielectric constant of chloroform. While there was a large exothermic shift for reactions involving charged nucleophiles with solvation modeling, the corresponding shift was minimal for the reaction with neutral nucleophiles. PMID:18538754

Motion Planning in a Society of Intelligent Mobile Agents

NASA Technical Reports Server (NTRS)

Esterline, Albert C.; Shafto, Michael (Technical Monitor)

2002-01-01

The majority of the work on this grant involved formal modeling of human-computer integration. We conceptualize computer resources as a multiagent system so that these resources and human collaborators may be modeled uniformly. In previous work we had used modal for this uniform modeling, and we had developed a process-algebraic agent abstraction. In this work, we applied this abstraction (using CSP) in uniformly modeling agents and users, which allowed us to use tools for investigating CSP models. This work revealed the power of, process-algebraic handshakes in modeling face-to-face conversation. We also investigated specifications of human-computer systems in the style of algebraic specification. This involved specifying the common knowledge required for coordination and process-algebraic patterns of communication actions intended to establish the common knowledge. We investigated the conditions for agents endowed with perception to gain common knowledge and implemented a prototype neural-network system that allows agents to detect when such conditions hold. The literature on multiagent systems conceptualizes communication actions as speech acts. We implemented a prototype system that infers the deontic effects (obligations, permissions, prohibitions) of speech acts and detects violations of these effects. A prototype distributed system was developed that allows users to collaborate in moving proxy agents; it was designed to exploit handshakes and common knowledge Finally. in work carried over from a previous NASA ARC grant, about fifteen undergraduates developed and presented projects on multiagent motion planning.

Study on the E-commerce platform based on the agent

NASA Astrophysics Data System (ADS)

Fu, Ruixue; Qin, Lishuan; Gao, Yinmin

2011-10-01

To solve problem of dynamic integration in e-commerce, the Multi-Agent architecture of electronic commerce platform system based on Agent and Ontology has been introduced, which includes three major types of agent, Ontology and rule collection. In this architecture, service agent and rule are used to realize the business process reengineering, the reuse of software component, and agility of the electronic commerce platform. To illustrate the architecture, a simulation work has been done and the results imply that the architecture provides a very efficient method to design and implement the flexible, distributed, open and intelligent electronic commerce platform system to solve problem of dynamic integration in ecommerce. The objective of this paper is to illustrate the architecture of electronic commerce platform system, and the approach how Agent and Ontology support the electronic commerce platform system.

Contract Monitoring in Agent-Based Systems: Case Study

NASA Astrophysics Data System (ADS)

Hodík, Jiří; Vokřínek, Jiří; Jakob, Michal

Monitoring of fulfilment of obligations defined by electronic contracts in distributed domains is presented in this paper. A two-level model of contract-based systems and the types of observations needed for contract monitoring are introduced. The observations (inter-agent communication and agents’ actions) are collected and processed by the contract observation and analysis pipeline. The presented approach has been utilized in a multi-agent system for electronic contracting in a modular certification testing domain.

The Study on Collaborative Manufacturing Platform Based on Agent

NASA Astrophysics Data System (ADS)

Zhang, Xiao-yan; Qu, Zheng-geng

To fulfill the trends of knowledge-intensive in collaborative manufacturing development, we have described multi agent architecture supporting knowledge-based platform of collaborative manufacturing development platform. In virtue of wrapper service and communication capacity agents provided, the proposed architecture facilitates organization and collaboration of multi-disciplinary individuals and tools. By effectively supporting the formal representation, capture, retrieval and reuse of manufacturing knowledge, the generalized knowledge repository based on ontology library enable engineers to meaningfully exchange information and pass knowledge across boundaries. Intelligent agent technology increases traditional KBE systems efficiency and interoperability and provides comprehensive design environments for engineers.

Phase 2 study of ABT-510 in patients with previously untreated advanced renal cell carcinoma.

PubMed

Ebbinghaus, Scot; Hussain, Maha; Tannir, Nizar; Gordon, Michael; Desai, Apurva A; Knight, Raymond A; Humerickhouse, Rod A; Qian, Jiang; Gordon, Gary B; Figlin, Robert

2007-11-15

Angiogenesis is a characteristic of renal cell carcinoma. ABT-510 is an angiogenesis inhibitor that mimics the antiangiogenic properties of thrombospondin-1. This study was designed to assess the safety and efficacy of ABT-510 in patients with advanced renal cell carcinoma. Patients with previously untreated metastatic or unresectable renal cell carcinoma were randomized to treatment with one of two doses of ABT-510, self-administered s.c. twice daily in 28-day treatment periods without intervening rest periods. End points were progression-free survival (PFS), objective response rate, overall survival, and toxicity. The objective response rate was 4% in the 10 mg twice daily group, and there were two unconfirmed PRs in the 100 mg twice daily group. Respective median PFS was 4.2 and 3.3 months, with a 6-month PFS of 39% and 32%. Median overall survival was 27.8 months (10 mg twice daily) and 26.1 months (100 mg twice daily). The most frequent adverse events were injection site reactions (84%), fatigue (50%), headache (20%), and nausea (19%). The incidence of treatment-related, grade 3/4 adverse events was low and included three bleeding episodes (gastrointestinal hemorrhage, intracranial hemorrhage, and hemoptysis) and one thrombotic event (deep vein thrombosis). No deaths were attributed to ABT-510. There was little evidence of clinical activity for ABT-510, and further evaluation as a single agent for treating advanced renal cell carcinoma is not warranted. The evidence of a favorable safety profile may justify further evaluation in combination therapy.

Time-Extended Policies in Mult-Agent Reinforcement Learning

NASA Technical Reports Server (NTRS)

Tumer, Kagan; Agogino, Adrian K.

2004-01-01

Reinforcement learning methods perform well in many domains where a single agent needs to take a sequence of actions to perform a task. These methods use sequences of single-time-step rewards to create a policy that tries to maximize a time-extended utility, which is a (possibly discounted) sum of these rewards. In this paper we build on our previous work showing how these methods can be extended to a multi-agent environment where each agent creates its own policy that works towards maximizing a time-extended global utility over all agents actions. We show improved methods for creating time-extended utilities for the agents that are both "aligned" with the global utility and "learnable." We then show how to crate single-time-step rewards while avoiding the pi fall of having rewards aligned with the global reward leading to utilities not aligned with the global utility. Finally, we apply these reward functions to the multi-agent Gridworld problem. We explicitly quantify a utility's learnability and alignment, and show that reinforcement learning agents using the prescribed reward functions successfully tradeoff learnability and alignment. As a result they outperform both global (e.g., team games ) and local (e.g., "perfectly learnable" ) reinforcement learning solutions by as much as an order of magnitude.

CATS-based Air Traffic Controller Agents

NASA Technical Reports Server (NTRS)

Callantine, Todd J.

2002-01-01

This report describes intelligent agents that function as air traffic controllers. Each agent controls traffic in a single sector in real time; agents controlling traffic in adjoining sectors can coordinate to manage an arrival flow across a given meter fix. The purpose of this research is threefold. First, it seeks to study the design of agents for controlling complex systems. In particular, it investigates agent planning and reactive control functionality in a dynamic environment in which a variety perceptual and decision making skills play a central role. It examines how heuristic rules can be applied to model planning and decision making skills, rather than attempting to apply optimization methods. Thus, the research attempts to develop intelligent agents that provide an approximation of human air traffic controller behavior that, while not based on an explicit cognitive model, does produce task performance consistent with the way human air traffic controllers operate. Second, this research sought to extend previous research on using the Crew Activity Tracking System (CATS) as the basis for intelligent agents. The agents use a high-level model of air traffic controller activities to structure the control task. To execute an activity in the CATS model, according to the current task context, the agents reference a 'skill library' and 'control rules' that in turn execute the pattern recognition, planning, and decision-making required to perform the activity. Applying the skills enables the agents to modify their representation of the current control situation (i.e., the 'flick' or 'picture'). The updated representation supports the next activity in a cycle of action that, taken as a whole, simulates air traffic controller behavior. A third, practical motivation for this research is to use intelligent agents to support evaluation of new air traffic control (ATC) methods to support new Air Traffic Management (ATM) concepts. Current approaches that use large, human

A Diversified Investment Strategy Using Autonomous Agents

NASA Astrophysics Data System (ADS)

Barbosa, Rui Pedro; Belo, Orlando

In a previously published article, we presented an architecture for implementing agents with the ability to trade autonomously in the Forex market. At the core of this architecture is an ensemble of classification and regression models that is used to predict the direction of the price of a currency pair. In this paper, we will describe a diversified investment strategy consisting of five agents which were implemented using that architecture. By simulating trades with 18 months of out-of-sample data, we will demonstrate that data mining models can produce profitable predictions, and that the trading risk can be diminished through investment diversification.

Intelligent Agent Transparency in Human-Agent Teaming for Multi-UxV Management.

PubMed

Mercado, Joseph E; Rupp, Michael A; Chen, Jessie Y C; Barnes, Michael J; Barber, Daniel; Procci, Katelyn

2016-05-01

We investigated the effects of level of agent transparency on operator performance, trust, and workload in a context of human-agent teaming for multirobot management. Participants played the role of a heterogeneous unmanned vehicle (UxV) operator and were instructed to complete various missions by giving orders to UxVs through a computer interface. An intelligent agent (IA) assisted the participant by recommending two plans-a top recommendation and a secondary recommendation-for every mission. A within-subjects design with three levels of agent transparency was employed in the present experiment. There were eight missions in each of three experimental blocks, grouped by level of transparency. During each experimental block, the IA was incorrect three out of eight times due to external information (e.g., commander's intent and intelligence). Operator performance, trust, workload, and usability data were collected. Results indicate that operator performance, trust, and perceived usability increased as a function of transparency level. Subjective and objective workload data indicate that participants' workload did not increase as a function of transparency. Furthermore, response time did not increase as a function of transparency. Unlike previous research, which showed that increased transparency resulted in increased performance and trust calibration at the cost of greater workload and longer response time, our results support the benefits of transparency for performance effectiveness without additional costs. The current results will facilitate the implementation of IAs in military settings and will provide useful data to the design of heterogeneous UxV teams. © 2016, Human Factors and Ergonomics Society.

Role of Glutamate Release and Metabotropic Autoreceptors in Seizureogenic Actions of Cholinomimetic Agents

DTIC Science & Technology

2001-10-01

produced by centrally-active cholinomimetic agents and to evaluate possible palliative treatments for central cholinomimetic toxicity. The scope of...REPORT: 10/01/00-09/30/01 AWARD NUMBER: DAMD17-98-1-8617 evaluation of the effects by intracerebral infusion of the organophosphate agent paraoxon on EEG...agents. Previously, we had reported successful induction of seizure-like changes in EEG activity of anesthetized rats following intracerebral infusion

Nondestructive Intervention to Multi-Agent Systems through an Intelligent Agent

PubMed Central

Han, Jing; Wang, Lin

2013-01-01

For a given multi-agent system where the local interaction rule of the existing agents can not be re-designed, one way to intervene the collective behavior of the system is to add one or a few special agents into the group which are still treated as normal agents by the existing ones. We study how to lead a Vicsek-like flocking model to reach synchronization by adding special agents. A popular method is to add some simple leaders (fixed-headings agents). However, we add one intelligent agent, called ‘shill’, which uses online feedback information of the group to decide the shill's moving direction at each step. A novel strategy for the shill to coordinate the group is proposed. It is strictly proved that a shill with this strategy and a limited speed can synchronize every agent in the group. The computer simulations show the effectiveness of this strategy in different scenarios, including different group sizes, shill speed, and with or without noise. Compared to the method of adding some fixed-heading leaders, our method can guarantee synchronization for any initial configuration in the deterministic scenario and improve the synchronization level significantly in low density groups, or model with noise. This suggests the advantage and power of feedback information in intervention of collective behavior. PMID:23658695

Effect of donepezil in patients with Alzheimer's disease previously untreated or treated with memantine or nootropic agents in Germany: an observational study.

PubMed

Klinger, Tatjana; Ibach, Bernd; Schoenknecht, Peter; Kamleiter, Martin; Silver, Gabrielle; Schroeder, Johannes; Mielke, Ruediger

2005-05-01

This open-label, prospective, observational, Post-Marketing Surveillance (PMS) study assessed the efficacy and safety of donepezil in patients who had been switched from therapies currently used in Germany to treat Alzheimer's disease (AD), such as memantine and nootropics, due to insufficient efficacy or poor tolerability. A treatment-naive population was included as a comparator. Patients with AD were treated with donepezil and observed for a period of approximately 3 months. A cognitive assessment was made using the Mini-Mental State Examination (MMSE). Quality of life (QoL) was assessed by the investigators who answered the question 'How did therapy with donepezil influence the QoL of the patient and/or his family over the observation period?' and was graded using three ratings: improved/unchanged/worsened. Adverse events (AEs) were also monitored. A total of 913 patients entered the study (mean +/- SD MMSE score 18.03 +/- 5.34). Efficacy assessments were analyzed for three groups: an overall group of patients who had received any form of prior AD drug therapy (N+ group; n = 709); a subgroup of patients from the N+ group who had received prior memantine therapy only (M+ group; n = 111) and patients who were drug treatment naive (N- group; n = 204). In the evaluable population donepezil improved MMSE scores by 2.21 +/- 3.47 points on average, with similar improvements observed in all three groups. QoL was judged to be improved in at least 70% of patients, again with similar results obtained for all three groups. Donepezil was well tolerated, with 85 of 913 (9.3%) patients reporting AEs. The most common AEs were those typically seen with cholinergic therapies (i.e., diarrhoea, vomiting and nausea). In this observational PMS study, donepezil was shown to be efficacious and well tolerated in patients who were being insufficiently treated with memantine or nootropic therapy. The magnitude of response was similar to that observed in patients who were previously

Adaptive behaviors in multi-agent source localization using passive sensing.

PubMed

Shaukat, Mansoor; Chitre, Mandar

2016-12-01

In this paper, the role of adaptive group cohesion in a cooperative multi-agent source localization problem is investigated. A distributed source localization algorithm is presented for a homogeneous team of simple agents. An agent uses a single sensor to sense the gradient and two sensors to sense its neighbors. The algorithm is a set of individualistic and social behaviors where the individualistic behavior is as simple as an agent keeping its previous heading and is not self-sufficient in localizing the source. Source localization is achieved as an emergent property through agent's adaptive interactions with the neighbors and the environment. Given a single agent is incapable of localizing the source, maintaining team connectivity at all times is crucial. Two simple temporal sampling behaviors, intensity-based-adaptation and connectivity-based-adaptation, ensure an efficient localization strategy with minimal agent breakaways. The agent behaviors are simultaneously optimized using a two phase evolutionary optimization process. The optimized behaviors are estimated with analytical models and the resulting collective behavior is validated against the agent's sensor and actuator noise, strong multi-path interference due to environment variability, initialization distance sensitivity and loss of source signal.

Source Update Capture in Information Agents

NASA Technical Reports Server (NTRS)

Ashish, Naveen; Kulkarni, Deepak; Wang, Yao

2003-01-01

In this paper we present strategies for successfully capturing updates at Web sources. Web-based information agents provide integrated access to autonomous Web sources that can get updated. For many information agent applications we are interested in knowing when a Web source to which the application provides access, has been updated. We may also be interested in capturing all the updates at a Web source over a period of time i.e., detecting the updates and, for each update retrieving and storing the new version of data. Previous work on update and change detection by polling does not adequately address this problem. We present strategies for intelligently polling a Web source for efficiently capturing changes at the source.

Increasing nerve agent treatment efficacy by P-glycoprotein inhibition.

PubMed

Joosen, Marloes J A; Vester, Stefanie M; Hamelink, Jouk; Klaassen, Steven D; van den Berg, Roland M

2016-11-25

One of the shortcomings of current treatment of nerve agent poisoning is that not all drugs effectively penetrate the blood-brain barrier (BBB), whereas most nerve agents easily do. P-glycoprotein (Pgp) efflux transporters at the BBB may contribute to this aspect. It was previously shown that Pgp inhibition by tariquidar enhanced the efficacy of nerve agent treatment when administered as a pretreatment. In the present study soman-induced seizures were also substantially prevented when the animals were intravenously treated with tariquidar post-poisoning, in addition to HI-6 and atropine. In these animals, approximately twice as much AChE activity was present in their brain as compared to control rats. The finding that tariquidar did not affect distribution of soman to the brain indicates that the potentiating effects were a result of interactions of Pgp inhibition with drug distribution. In line with this, atropine appeared to be a substrate for Pgp in in vitro studies in a MDR1/MDCK cell model. This indicates that tariquidar might induce brain region specific effects on atropine distribution, which could contribute to the therapeutic efficacy increase found. Furthermore, the therapeutic enhancement by tariquidar was compared to that of the less specific and less potent Pgp inhibitor cyclosporine A. This compound appeared to induce a protective effect similar to tariquidar. In conclusion, treatment with a Pgp inhibitor resulted in enhanced therapeutic efficacy of HI-6 and atropine in a soman-induced seizure model in the rat. The mechanism underlying these effects should be further investigated. To that end, the potentiating effect of nerve agent treatment should be addressed against a broader range of nerve agents, for oximes and atropine separately, and for those at lower doses. In particular when efficacy against more nerve agents is shown, a Pgp inhibitor such as tariquidar might be a valid addition to nerve agent antidotes. Copyright © 2016 Elsevier Ireland

Agent Architectures for Compliance

NASA Astrophysics Data System (ADS)

Burgemeestre, Brigitte; Hulstijn, Joris; Tan, Yao-Hua

A Normative Multi-Agent System consists of autonomous agents who must comply with social norms. Different kinds of norms make different assumptions about the cognitive architecture of the agents. For example, a principle-based norm assumes that agents can reflect upon the consequences of their actions; a rule-based formulation only assumes that agents can avoid violations. In this paper we present several cognitive agent architectures for self-monitoring and compliance. We show how different assumptions about the cognitive architecture lead to different information needs when assessing compliance. The approach is validated with a case study of horizontal monitoring, an approach to corporate tax auditing recently introduced by the Dutch Customs and Tax Authority.

Fronto-parietal coding of goal-directed actions performed by artificial agents.

PubMed

Kupferberg, Aleksandra; Iacoboni, Marco; Flanagin, Virginia; Huber, Markus; Kasparbauer, Anna; Baumgartner, Thomas; Hasler, Gregor; Schmidt, Florian; Borst, Christoph; Glasauer, Stefan

2018-03-01

With advances in technology, artificial agents such as humanoid robots will soon become a part of our daily lives. For safe and intuitive collaboration, it is important to understand the goals behind their motor actions. In humans, this process is mediated by changes in activity in fronto-parietal brain areas. The extent to which these areas are activated when observing artificial agents indicates the naturalness and easiness of interaction. Previous studies indicated that fronto-parietal activity does not depend on whether the agent is human or artificial. However, it is unknown whether this activity is modulated by observing grasping (self-related action) and pointing actions (other-related action) performed by an artificial agent depending on the action goal. Therefore, we designed an experiment in which subjects observed human and artificial agents perform pointing and grasping actions aimed at two different object categories suggesting different goals. We found a signal increase in the bilateral inferior parietal lobule and the premotor cortex when tool versus food items were pointed to or grasped by both agents, probably reflecting the association of hand actions with the functional use of tools. Our results show that goal attribution engages the fronto-parietal network not only for observing a human but also a robotic agent for both self-related and social actions. The debriefing after the experiment has shown that actions of human-like artificial agents can be perceived as being goal-directed. Therefore, humans will be able to interact with service robots intuitively in various domains such as education, healthcare, public service, and entertainment. © 2017 Wiley Periodicals, Inc.

[Management of Patients on Antithrombotic Agents Undergoing Endoscopy].

PubMed

Kim, Joon Sung; Kim, Byung Wook

2018-05-25

Antithrombotic agents are used increasingly in Asia. The management of patients on antithrombotics undergoing elective or emergency endoscopy has become an increasing clinical challenge for gastroenterologists. Current practice guidelines have been developed by societies from western countries. On the other hand, these guidelines cannot meet the specific needs of the Asian Pacific region, raising the need for separate guidelines in Asia. This review compares the recommendations of previous guidelines with the most recently published Asian guidelines regarding the management of patients on antithrombotic agents undergoing elective and emergency endoscopy.

Study on Heat Transfer Agent Models of Transmission Line and Transformer

NASA Astrophysics Data System (ADS)

Wang, B.; Zhang, P. P.

2018-04-01

When using heat transfer simulation to study the dynamic overload of transmission line and transformer, it needs to establish the mathematical expression of heat transfer. However, the formula is a nonlinear differential equation or equation set and it is not easy to get general solutions. Aiming at this problem, some different temperature change processes caused by different initial conditions are calculated by differential equation and equation set. New agent models are developed according to the characteristics of different temperature change processes. The results show that the agent models have high precision and can solve the problem that the original equation cannot be directly applied in some practical engineers.

Review of CO2 as a Euthanasia Agent for Laboratory Rats and Mice

PubMed Central

Boivin, Gregory P; Hickman, Debra L; Creamer-Hente, Michelle A; Pritchett-Corning, Kathleen R; Bratcher, Natalie A

2017-01-01

Selecting an appropriate, effective euthanasia agent is controversial. Several recent publications provide clarity on the use of CO2 in laboratory rats and mice. This review examines previous studies on CO2 euthanasia and presents the current body of knowledge on the subject. Potential areas for further investigation and recommendations are provided. PMID:28903819

Anesthetic Agent-Specific Effects on Synaptic Inhibition

PubMed Central

MacIver, M. Bruce

2014-01-01

Background Anesthetics enhance gamma-aminobutyric acid (GABA)-mediated inhibition in the central nervous system. Different agents have been shown to act on tonic versus synaptic GABA receptors to different degrees, but it remains unknown whether different forms of synaptic inhibition are also differentially engaged. With this in mind, we tested the hypothesis that different types of GABA-mediated synapses exhibit different anesthetic sensitivities. The present study compared effects produced by isoflurane, halothane, pentobarbital, thiopental and propofol on paired pulse GABAA receptor-mediated synaptic inhibition. Effects on glutamate-mediated facilitation were also studied. Methods Synaptic responses were measured in rat hippocampal brain slices. Orthodromic paired pulse stimulation was used to assess anesthetic effects on either glutamate-mediated excitatory inputs or GABA-mediated inhibitory inputs to CA1 neurons. Antidromic stimulation was used to assess anesthetic effects on CA1 background excitability. Agents were studied at equi-effective concentrations for population spike depression to compare their relative degree of effect on synaptic inhibition. Results Differing degrees of anesthetic effect on paired pulse facilitation at excitatory glutamate synapses were evident, and blocking GABA inhibition revealed a previously unseen presynaptic action for pentobarbital. Although all five anesthetics depressed synaptically evoked excitation of CA1 neurons, the involvement of enhanced GABA-mediated inhibition differed considerably among agents. Single pulse inhibition was enhanced by propofol, thiopental and pentobarbital, but only marginally by halothane and isoflurane. In contrast, isoflurane enhanced paired pulse inhibition strongly, as did thiopental, but propofol, pentobarbital and halothane were less effective. Conclusions These observations support the idea that different GABA synapses use receptors with differing subunit compositions, and that anesthetics

Design, Implementation and Case Study of WISEMAN: WIreless Sensors Employing Mobile AgeNts

NASA Astrophysics Data System (ADS)

González-Valenzuela, Sergio; Chen, Min; Leung, Victor C. M.

We describe the practical implementation of Wiseman: our proposed scheme for running mobile agents in Wireless Sensor Networks. Wiseman’s architecture derives from a much earlier agent system originally conceived for distributed process coordination in wired networks. Given the memory constraints associated with small sensor devices, we revised the architecture of the original agent system to make it applicable to this type of networks. Agents are programmed as compact text scripts that are interpreted at the sensor nodes. Wiseman is currently implemented in TinyOS ver. 1, its binary image occupies 19Kbytes of ROM memory, and it occupies 3Kbytes of RAM to operate. We describe the rationale behind Wiseman’s interpreter architecture and unique programming features that can help reduce packet overhead in sensor networks. In addition, we gauge the proposed system’s efficiency in terms of task duration with different network topologies through a case study that involves an early-fire-detection application in a fictitious forest setting.

Progress in the development of gelling agents for improved culturability of microorganisms

PubMed Central

Das, Nabajit; Tripathi, Naveen; Basu, Srijoni; Bose, Chandra; Maitra, Susmit; Khurana, Sukant

2015-01-01

Gelling agents are required for formulating both solid and semisolid media, vital for the isolation of microorganisms. Gelatin was the first gelling agent to be discovered but it soon paved the way for agar, which has far superior material qualities. Source depletion, issues with polymerase-chain-reaction and inability to sustain extermophiles etc., necessitate the need of other gelling agents. Many new gelling agents, such as xantham gum, gellan gum, carrageenan, isubgol, and guar gum have been formulated, raising the hopes for the growth of previously unculturable microorganisms. We evaluate the progress in the development of gelling agents, with the hope that our synthesis would help accelerate research in the field. PMID:26257708

Current and Developing Technologies for Monitoring Agents of Bioterrorism and Biowarfare

PubMed Central

Lim, Daniel V.; Simpson, Joyce M.; Kearns, Elizabeth A.; Kramer, Marianne F.

2005-01-01

Recent events have made public health officials acutely aware of the importance of rapidly and accurately detecting acts of bioterrorism. Because bioterrorism is difficult to predict or prevent, reliable platforms to rapidly detect and identify biothreat agents are important to minimize the spread of these agents and to protect the public health. These platforms must not only be sensitive and specific, but must also be able to accurately detect a variety of pathogens, including modified or previously uncharacterized agents, directly from complex sample matrices. Various commercial tests utilizing biochemical, immunological, nucleic acid, and bioluminescence procedures are currently available to identify biological threat agents. Newer tests have also been developed to identify such agents using aptamers, biochips, evanescent wave biosensors, cantilevers, living cells, and other innovative technologies. This review describes these current and developing technologies and considers challenges to rapid, accurate detection of biothreat agents. Although there is no ideal platform, many of these technologies have proved invaluable for the detection and identification of biothreat agents. PMID:16223949

Design and Control of Large Collections of Learning Agents

NASA Technical Reports Server (NTRS)

Agogino, Adrian

2001-01-01

The intelligent control of multiple autonomous agents is an important yet difficult task. Previous methods used to address this problem have proved to be either too brittle, too hard to use, or not scalable to large systems. The 'Collective Intelligence' project at NASA/Ames provides an elegant, machine-learning approach to address these problems. This approach mathematically defines some essential properties that a reward system should have to promote coordinated behavior among reinforcement learners. This work has focused on creating additional key properties and algorithms within the mathematics of the Collective Intelligence framework. One of the additions will allow agents to learn more quickly, in a more coordinated manner. The other will let agents learn with less knowledge of their environment. These additions will allow the framework to be applied more easily, to a much larger domain of multi-agent problems.

Microbioassay of Antimicrobial Agents

PubMed Central

Simon, Harold J.; Yin, E. Jong

1970-01-01

A previously described agar-diffusion technique for microbioassay of antimicrobial agents has been modified to increase sensitivity of the technique and to extend the range of antimicrobial agents to which it is applicable. This microtechnique requires only 0.02 ml of an unknown test sample for assay, and is capable of measuring minute concentrations of antibiotics in buffer, serum, and urine. In some cases, up to a 20-fold increase in sensitivity is gained relative to other published standardized methods and the error of this method is less than ±5%. Buffer standard curves have been established for this technique, concurrently with serum standard curves, yielding information on antimicrobial serum-binding and demonstrating linearity of the data points compared to the estimated regression line for the microconcentration ranges covered by this technique. This microassay technique is particularly well suited for pediatric research and for other investigations where sample volumes are small and quantitative accuracy is desired. Dilution of clinical samples to attain concentrations falling with the range of this assay makes the technique readily adaptable and suitable for general clinical pharmacological studies. The microassay technique has been standardized in buffer solutions and in normal human serum pools for the following antimicrobials: ampicillin, methicillin, penicillin G, oxacillin, cloxacillin, dicloxacillin, cephaloglycin, cephalexin, cephaloridine, cephalothin, erythromycin, rifamycin amino methyl piperazine, kanamycin, neomycin, streptomycin, colistin, polymyxin B, doxycycline, minocycline, oxytetracycline, tetracycline, and chloramphenicol. PMID:4986725

Development of inhibition as a function of the presence of a supernatural agent.

PubMed

King, Ashley C

2011-01-01

In this study the author examined the developmental differences in inhibition and cognition of 4-8-year-old children as a function of the suggested presence of a supernatural agent. Previous evolutionarily-relevant research has suggested that humans are naturally primed to think in terms of supernatural agents and that, given the correct context, individuals readily accept novel supernatural entities and alter their behavior accordingly. All children in this study played 4 games designed to assess their present level of inhibitory and cognitive development. Children in the experimental condition were also introduced to an invisible Princess Alice and were told that she was watching during the games. Following these measures, all children engaged in a resistance-to-temptation task. Results revealed that cognitively advanced children were more likely to express belief in Princess Alice than were less cognitively advanced children. This research provides support that cognitive maturity, rather than immaturity, may be necessary for children to express belief in novel supernatural agents.

Anticlotting agents and the surgical management of glaucoma.

PubMed

Sozeri, Yasemin; Salim, Sarwat

2018-03-01

A large subset of patients with glaucoma uses anticlotting agents. No standardized guidelines currently exist for managing these agents in the specific perioperative setting of glaucoma surgery. The present review focuses on currently available anticlotting agents, their influence on hemorrhagic complications following glaucoma surgery, and management strategies for their use in the perioperative period RECENT FINDINGS: Anticlotting agents increase the risk of perioperative hemorrhagic complications following glaucoma surgery. Other factors that increase that risk have been identified as well, including the type of glaucoma surgery, preoperative intraocular pressure, postoperative hypotony, previous ocular surgeries, and race. Although general guidelines in the perioperative management of blood thinning agents exist, the best way to apply these guidelines specifically to glaucoma surgery remains unclear. Blood thinners are widely used and can increase the risk of hemorrhagic complications in patients undergoing glaucoma surgery. Managing these agents in the perioperative setting is challenging and should be done in collaboration with the patient's primary care provider, hematologist, or cardiologist. Management strategies should be tailored to each individual's risk of hemorrhage versus thromboembolism. Additionally, surgical plans can be modified to help minimize hemorrhagic outcomes, especially in patients who are deemed to be at high risk for perioperative bleeding.

Security patterns and a weighting scheme for mobile agents

NASA Astrophysics Data System (ADS)

Walker, Jessie J.

The notion of mobility has always been a prime factor in human endeavor and achievement. This need to migrate by humans has been distilled into software entities, which are their representatives on distant environments. Software agents are developed to act on behalf of a user. Mobile agents were born from the understanding that many times it was much more useful to move the code (program) to where the resources are located, instead of connecting remotely. Within the mobile agent research community, security has traditionally been the most defining issue facing the community and preventing the paradigm from gaining wide acceptance. There are still numerous difficult problems being addressed with very few practical solutions, such as the malicious host and agent problems. These problems are some of the most active areas of research within the mobile agent community. The major principles, facets, fundamental concepts, techniques and architectures of the field are well understood within the community. This is evident by the many mobile agent systems developed in the last decade that share common core components such as agent management, communication facilities, and mobility services. In other words new mobile agent systems and frameworks do not provide any new insights into agent system architecture or mobility services, agent coordination, communication that could be useful to the agent research community, although these new mobile agent systems do in many instances validate, refine, demonstrate the reuse of many previously proposed and discussed mobile agent research elements. Since mobile agent research for the last decade has been defined by security and related issues, our research into security patterns are within this narrow arena of mobile agent research. The research presented in this thesis examines the issue of mobile agent security from the standpoint of security pattern documented from the universe of mobile agent systems. In addition, we explore how

Decomposing Animacy Reversals between Agents and Experiencers: An ERP Study

ERIC Educational Resources Information Center

Bourguignon, Nicolas; Drury, John E.; Valois, Daniel; Steinhauer, Karsten

2012-01-01

The present study aimed to refine current hypotheses regarding thematic reversal anomalies, which have been found to elicit either N400 or--more frequently--"semantic-P600" (sP600) effects. Our goal was to investigate whether distinct ERP profiles reflect aspectual-thematic differences between Agent-Subject Verbs (ASVs; e.g., "to eat") and…

Retrospective cohort study of anti-tumor necrosis factor agent use in a veteran population

PubMed Central

Madkour, Nermeen; Kazerooni, Rashid

2014-01-01

Introduction. Anti-tumor necrosis factor (TNF) agents are effective for several immunologic conditions (rheumatoid arthritis (RA), Crohn’s disease (CD), and psoriasis). The purpose of this study was to evaluate the efficacy and safety of anti-TNF agents via chart review. Methods. Single-site, retrospective cohort study that evaluated the efficacy and safety of anti-TNF agents in veterans initiated between 2010 and 2011. Primary aim evaluated response at 12 months post-index date. Secondary aims evaluated initial response prior to 12 months post-index date and infection events. Results. A majority of patients were prescribed anti-TNF agents for CD (27%) and RA (24%). Patients were initiated on etanercept (41%), adalimumab (40%), and infliximab (18%) between 2010 and 2011. No differences in patient demographics were reported. Response rates were high overall. Sixty-five percent of etanercept patients, 82% of adalimumab patients, and 59% of infliximab patients were either partial or full responders, respectively. Approximately 16%, 11%, and 12% of etanercept, adalimumab, and infliximab were non-responders, respectively. Infections between the groups were non-significant. Etanercept and adalimumab patients had higher but non-significant odds of being a responder relative to infliximab. Conclusions. Most patients initiated with anti-TNF agent were responders at 12 months follow-up for all indications in a veteran population. PMID:24883246

LAPAROSCOPY AFTER PREVIOUS LAPAROTOMY

PubMed Central

Godinjak, Zulfo; Idrizbegović, Edin; Begić, Kerim

2006-01-01

Following the abdominal surgery, extensive adhesions often occur and they can cause difficulties during laparoscopic operations. However, previous laparotomy is not considered to be a contraindication for lap-aroscopy. The aim of this study is to present that an insertion of Veres needle in the region of umbilicus is a safe method for creating a pneumoperitoneum for laparoscopic operations after previous laparotomy. In the last three years, we have performed 144 laparoscopic operations in patients that previously underwent one or two laparotomies. Pathology of digestive system, genital organs, Cesarean Section or abdominal war injuries were the most common causes of previous laparotomy. During those operations or during entering into abdominal cavity we have not experienced any complications, while in 7 patients we performed conversion to laparotomy following the diagnostic laparoscopy. In all patients an insertion of Veres needle and trocar insertion in the umbilical region was performed, namely a technique of closed laparoscopy. Not even in one patient adhesions in the region of umbilicus were found, and no abdominal organs were injured. PMID:17177649

Rates of, and risk factors for, severe infections in patients with systemic autoimmune diseases receiving biological agents off-label

PubMed Central

2011-01-01

Introduction The purpose of this observational study was to analyze the rates, characteristics and associated risk factors of severe infections in patients with systemic autoimmune diseases (SAD) who were treated off-label with biological agents in daily practice. Methods The BIOGEAS registry is an ongoing Spanish prospective cohort study investigating the long-term safety and efficacy of the off-label use of biological agents in adult patients with severe, refractory SAD. Severe infections were defined according to previous studies as those that required intravenous treatment or that led to hospitalization or death. Patients contributed person-years of follow-up for the period in which they were treated with biological agents. Results A total of 344 patients with SAD treated with biological agents off-label were included in the Registry until July 2010. The first biological therapies included rituximab in 264 (77%) patients, infliximab in 37 (11%), etanercept in 21 (6%), adalimumab in 19 (5%), and 'other' agents in 3 (1%). Forty-five severe infections occurred in 37 patients after a mean follow-up of 26.76 months. These infections resulted in four deaths. The crude rate of severe infections was 90.9 events/1000 person-years (112.5 for rituximab, 76.9 for infliximab, 66.9 for adalimumab and 30.5 for etanercept respectively). In patients treated with more than two courses of rituximab, the crude rate of severe infection was 226.4 events/1000 person-years. A pathogen was identified in 24 (53%) severe infections. The most common sites of severe infection were the lower respiratory tract (39%), bacteremia/sepsis (20%) and the urinary tract (16%). There were no significant differences relating to gender, SAD, agent, other previous therapies, number of previous immunosuppressive agents received or other therapies administered concomitantly. Cox regression analysis showed that age (P = 0.015) was independently associated with an increased risk of severe infection

Preclinical Studies of a Kidney Safe Iodinated Contrast Agent.

PubMed

Rowe, Elizabeth S; Rowe, Vernon D; Biswas, Sangita; Mosher, Gerold; Insisienmay, Lovella; Ozias, Marlies K; Gralinski, Michael R; Hunter, John; Barnett, James S

2016-09-01

Contrast-induced acute kidney injury (CI-AKI) is a serious complication of the use of iodinated contrast agents. This problem is particularly acute in interventional neurology and interventional cardiology, probably due to the intra-arterial route of injection, high contrast volumes, and preexisting risk factors of these patients. In an attempt to develop a contrast agent that is less damaging to the kidneys, we have studied the effects of adding a small amount of the substituted cyclodextrin, sulfobutyl-ether-β-cyclodextrin (SBECD), to iohexol in rodent models of renal toxicity. Renally compromised mice and rats were injected with iohexol and iohexol-SBECD via the tail vein. The renal pathology, creatinine clearance, and survival benefits of iohexol-SBECD were studied. The safety of direct intra-arterial injection of the iohexol-SBECD formulation was studied in a dog heart model system. Mechanism of action studies in cell culture model using a human kidney cell line was performed using flow cytometry. Nephrotoxicity was significantly reduced using iohexol-SBECD compared to iohexol alone, at mole ratios of iohexol:SBECD of 1:0.025. SBECD increased survival from 50% to 88% in a rat survival study. In the dog heart model, iohexol-SBECD was safe. Cell culture studies suggest that SBECD interferes with the early stages of contrast-induced apoptosis in a human renal cell line. We have shown that the addition of a small amount of SBECD (one molecule of SBECD per 40 iohexol molecules) significantly protects rodent kidneys from CI-AKI. Further development of this new formulation of iodinated contrast is warranted. © 2016 The Authors. Journal of Neuroimaging published by Wiley Periodicals, Inc. on behalf of American Society of Neuroimaging.

Attenuation of a select agent-excluded Burkholderia pseudomallei capsule mutant in hamsters.

PubMed

Gutierrez, Maria G; Warawa, Jonathan M

2016-05-01

Burkholderia pseudomallei is a Tier 1 select agent and potential bioweapon. Given it is potential to cause a lethal respiratory disease, research with fully virulent B. pseudomallei is conducted in Biosafety Level 3 (BSL-3) laboratory spaces. The logistical, financial, and administrative burden of Tier 1 select agent BSL-3 research has created an interest in mitigating such burdens through the use of either attenuated B. pseudomallei strains at BSL-2, or research with surrogate species, such as Burkholderia thailandensis. Previously, attenuated B. pseudomallei auxotroph mutants (asd and purM) have been approved for exclusion from select agent requirements, allowing for in vitro studies to be conducted at BSL-2. Acapsular B. pseudomallei mutants are known to be strongly attenuated in a variety of animal models, and yet acapsular B. pseudomallei mutants do not require nutritional supplementation, and can be studied within cultured macrophages, performing phenotypically similarly to parent strains. We demonstrate that the loss of a 30.8 kb region of the wcb capsule operon allows for a dramatic >4.46 log attenuation in a hamster intraperitoneal infection model, and report that this strain, JW270, has met criteria for exclusion from select agent requirements. Copyright © 2016 Elsevier B.V. All rights reserved.

Evaluation of new antiemetic agents and definition of antineoplastic agent emetogenicity--an update.

PubMed

Grunberg, Steven M; Osoba, David; Hesketh, Paul J; Gralla, Richard J; Borjeson, Sussanne; Rapoport, Bernardo L; du Bois, Andreas; Tonato, Maurizio

2005-02-01

Development of effective antiemetic therapy depends upon an understanding of both the antiemetic agents and the emetogenic challenges these agents are designed to address. New potential antiemetic agents should be studied in an orderly manner, proceeding from phase I to phase II open-label trials and then to randomized double-blind phase III trials comparing new agents and regimens to best standard therapy. Use of placebos in place of antiemetic therapy against highly or moderately emetogenic chemotherapy is unacceptable. Nausea and vomiting should be evaluated separately and for both the acute and delayed periods. Defining the emetogenicity of new antineoplastic agents is a challenge, since such data are often not reliably recorded during early drug development. A four-level classification system is proposed for emetogenicity of intravenous antineoplastic agents. A separate four-level classification system for emetogenicity of oral antineoplastic agents, which are often given over an extended period of time, is also proposed.

Topical antifungal agents: an update.

PubMed

Diehl, K B

1996-10-01

So many topical antifungal agents have been introduced that it has become very difficult to select the proper agent for a given infection. Nonspecific agents have been available for many years, and they are still effective in many situations. These agents include Whitfield's ointment, Castellani paint, gentian violet, potassium permanganate, undecylenic acid and selenium sulfide. Specific antifungal agents include, among others, the polyenes (nystatin, amphotericin B), the imidazoles (metronidazole, clotrimazole) and the allylamines (terbinafine, naftifine). Although the choice of an antifungal agent should be based on an accurate diagnosis, many clinicians believe that topical miconazole is a relatively effective agent for the treatment of most mycotic infections. Terbinafine and other newer drugs have primary fungicidal effects. Compared with older antifungal agents, these newer drugs can be used in lower concentrations and shorter therapeutic courses. Studies are needed to evaluate the clinical efficacies and cost advantages of both newer and traditional agents.

Statistical physics of the spatial Prisoner's Dilemma with memory-aware agents

NASA Astrophysics Data System (ADS)

Javarone, Marco Alberto

2016-02-01

We introduce an analytical model to study the evolution towards equilibrium in spatial games, with `memory-aware' agents, i.e., agents that accumulate their payoff over time. In particular, we focus our attention on the spatial Prisoner's Dilemma, as it constitutes an emblematic example of a game whose Nash equilibrium is defection. Previous investigations showed that, under opportune conditions, it is possible to reach, in the evolutionary Prisoner's Dilemma, an equilibrium of cooperation. Notably, it seems that mechanisms like motion may lead a population to become cooperative. In the proposed model, we map agents to particles of a gas so that, on varying the system temperature, they randomly move. In doing so, we are able to identify a relation between the temperature and the final equilibrium of the population, explaining how it is possible to break the classical Nash equilibrium in the spatial Prisoner's Dilemma when considering agents able to increase their payoff over time. Moreover, we introduce a formalism to study order-disorder phase transitions in these dynamics. As result, we highlight that the proposed model allows to explain analytically how a population, whose interactions are based on the Prisoner's Dilemma, can reach an equilibrium far from the expected one; opening also the way to define a direct link between evolutionary game theory and statistical physics.

SAR Studies on Trisubstituted Benzimidazoles as Inhibitors of Mtb FtsZ for the Development of Novel Antitubercular Agents

PubMed Central

Awasthi, Divya; Kumar, Kunal; Knudson, Susan E.; Slayden, Richard A.; Ojima, Iwao

2014-01-01

FtsZ, an essential protein for bacterial cell division, is a highly promising therapeutic target, especially for the discovery and development of new-generation anti-TB agents. Following up the identification of two lead 2,5,6-trisubstituted benzimidazoles, 1 and 2, targeting Mtb-FtsZ in our previous study, an extensive SAR study for optimization of these lead compounds was performed through systematic modification of the 5 and 6 positions. This study has successfully led to the discovery of a highly potent advanced lead 5f (MIC 0.06 µg/mL) and several other compounds with comparable potencies. These advanced lead compounds possess a dimethylamino group at the 6 position. The functional groups at the 5 position exhibit substantial effects on the antibacterial activity as well. In vitro experiments such as the FtsZ polymerization inhibitory assay and TEM analysis of Mtb-FtsZ treated with 5f and others indicate that Mtb-FtsZ is the molecular target for their antibacterial activity. PMID:24266862

SAR studies on trisubstituted benzimidazoles as inhibitors of Mtb FtsZ for the development of novel antitubercular agents.

PubMed

Awasthi, Divya; Kumar, Kunal; Knudson, Susan E; Slayden, Richard A; Ojima, Iwao

2013-12-12

FtsZ, an essential protein for bacterial cell division, is a highly promising therapeutic target, especially for the discovery and development of new-generation anti-TB agents. Following up the identification of two lead 2,5,6-trisubstituted benzimidazoles, 1 and 2, targeting Mtb-FtsZ in our previous study, an extensive SAR study for optimization of these lead compounds was performed through systematic modification of the 5 and 6 positions. This study has successfully led to the discovery of a highly potent advanced lead 5f (MIC = 0.06 μg/mL) and several other compounds with comparable potencies. These advanced lead compounds possess a dimethylamino group at the 6 position. The functional groups at the 5 position exhibit substantial effects on the antibacterial activity as well. In vitro experiments such as the FtsZ polymerization inhibitory assay and TEM analysis of Mtb-FtsZ treated with 5f and others indicate that Mtb-FtsZ is the molecular target for their antibacterial activity.

Utilization and costs of antipsychotic agents: a Canadian population-based study, 1996-2006.

PubMed

Alessi-Severini, Silvia; Biscontri, Robert G; Collins, David M; Kozyrskyj, Anita; Sareen, Jitender; Enns, Murray W

2008-05-01

This study evaluated the prescribing patterns and costs for antipsychotic agents in the population of the Canadian province of Manitoba over the past decade. A population-based study of antipsychotic utilization and costs was conducted on data collected from the administrative databases of the Manitoba Population Health Data Repository and the Statistics Canada census between index years 1996 and 2006 (April 1, 1995, through March 31, 2006). The total annual number of antipsychotic prescriptions dispensed in Manitoba increased by 227% between 1996 and 2006, and the prevalence of antipsychotic users increased by 62% over the same time interval. The fastest-growing segment of antipsychotic users in Manitoba appears to be young males, who increased from .16% in 1996 to .88% in 2006. The highest numbers of prescriptions were reported for schizophrenia, dementia, and conduct disorder. Annual expenditures for antipsychotics increased from $1.7 million in 1996 to $22.0 million in 2006 (expenditures are in Canadian dollars). The cost of second-generation agents reached 80% of total antipsychotic expenditures in 2006; risperidone was the most prescribed agent in all age groups of patients. The per-patient annual cost of antipsychotic pharmacotherapy increased by approximately 680% between 1996 and 2006 in Manitoba. The number of antipsychotic prescriptions and the prevalence of users of antipsychotic medications increased significantly in Manitoba over the study period, despite a steady-state population of approximately 1.2 million. Incremental costs relative to the use of antipsychotic medications can be explained by the market penetration of the second-generation agents and their expanded use in the treatment of various diagnoses.

Inner conflict in patients receiving oral anticancer agents: a qualitative study.

PubMed

Yagasaki, Kaori; Komatsu, Hiroko; Takahashi, Tsunehiro

2015-04-14

To explore the experiences of patients receiving oral anticancer agents. A qualitative study using semistructured interviews with a grounded theory approach. A university hospital in Japan. 14 patients with gastric cancer who managed their cancer with oral anticancer agents. Patients with cancer experienced inner conflict between rational belief and emotional resistance to taking medication due to confrontation with cancer, doubt regarding efficacy and concerns over potential harm attached to use of the agent. Although they perceived themselves as being adherent to medication, they reported partial non-adherent behaviours. The patients reassessed their lives through the experience of inner conflict and, ultimately, they recognised their role in medication therapy. Patients with cancer experienced inner conflict, in which considerable emotional resistance to taking their medication affected their occasional non-adherent behaviours. In patient-centred care, it is imperative that healthcare providers understand patients' inner conflict and inconsistency between their subjective view and behaviour to support patient adherence. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Father's occupational exposure to carcinogenic agents and childhood acute leukemia: a new method to assess exposure (a case-control study)

PubMed Central

Perez-Saldivar, Maria Luisa; Ortega-Alvarez, Manuel Carlos; Fajardo-Gutierrez, Arturo; Bernaldez-Rios, Roberto; del Campo-Martinez, Maria de los Angeles; Medina-Sanson, Aurora; Palomo-Colli, Miguel Angel; Paredes-Aguilera, Rogelio; Martínez-Avalos, Armando; Borja-Aburto, Victor Hugo; Rodriguez-Rivera, Maria de Jesus; Vargas-Garcia, Victor Manuel; Zarco-Contreras, Jesus; Flores-Lujano, Janet; Mejia-Arangure, Juan Manuel

2008-01-01

Background Medical research has not been able to establish whether a father's occupational exposures are associated with the development of acute leukemia (AL) in their offspring. The studies conducted have weaknesses that have generated a misclassification of such exposure. Occupations and exposures to substances associated with childhood cancer are not very frequently encountered in the general population; thus, the reported risks are both inconsistent and inaccurate. In this study, to assess exposure we used a new method, an exposure index, which took into consideration the industrial branch, specific position, use of protective equipment, substances at work, degree of contact with such substances, and time of exposure. This index allowed us to obtain a grade, which permitted the identification of individuals according to their level of exposure to known or potentially carcinogenic agents that are not necessarily specifically identified as risk factors for leukemia. The aim of this study was to determine the association between a father's occupational exposure to carcinogenic agents and the presence of AL in their offspring. Methods From 1999 to 2000, a case-control study was performed with 193 children who reside in Mexico City and had been diagnosed with AL. The initial sample-size calculation was 150 children per group, assessed with an expected odds ratio (OR) of three and a minimum exposure frequency of 15.8%. These children were matched by age, sex, and institution with 193 pediatric surgical patients at secondary-care hospitals. A questionnaire was used to determine each child's background and the characteristics of the father's occupation(s). In order to determine the level of exposure to carcinogenic agents, a previously validated exposure index (occupational exposure index, OEI) was used. The consistency and validity of the index were assessed by a questionnaire comparison, the sensory recognition of the work area, and an expert's opinion. Results The

When nightclub security agents assault clients more insight through a qualitative approach.

PubMed

Romain-Glassey, Nathalie; Gut, Melody; De Puy, Jacqueline; Mangin, Patrice

2014-08-01

Between 2007 and 2009, aggressions by security agents of nightclubs on clients increased from 6% to 10% among community violence situations encountered at the Violence Medical Unit (VMU) at the Lausanne University Hospital in Switzerland. Most victims were young men who had been drinking alcohol before the assault. About one quarter (25.7%) presented with one or several fractures, all of them in the head area. (For more details, refer to the previous article "When nightclub security agents assault clients" published in 2012(1).) Following this first study, we performed a second qualitative study in order to bring more information about the context and highlight victims' behaviors and experiences. Four themes emerged: how the assault began; the assault itself; third-party involvement; and the psychological state of victims when they consulted the VMU. The findings of this second study complemented the statistical results of the first study by showing under what circumstances security agents of nightclubs respond with physical violence to situations they consider a threat to security. Furthermore, the study described consequences for the victims that could be quite serious. Our findings support the need for nightclubs to improve selection and training of security staff. Copyright © 2014 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Ambient agents: embedded agents for remote control and monitoring using the PANGEA platform.

PubMed

Villarrubia, Gabriel; De Paz, Juan F; Bajo, Javier; Corchado, Juan M

2014-07-31

Ambient intelligence has advanced significantly during the last few years. The incorporation of image processing and artificial intelligence techniques have opened the possibility for such aspects as pattern recognition, thus allowing for a better adaptation of these systems. This study presents a new model of an embedded agent especially designed to be implemented in sensing devices with resource constraints. This new model of an agent is integrated within the PANGEA (Platform for the Automatic Construction of Organiztions of Intelligent Agents) platform, an organizational-based platform, defining a new sensor role in the system and aimed at providing contextual information and interacting with the environment. A case study was developed over the PANGEA platform and designed using different agents and sensors responsible for providing user support at home in the event of incidents or emergencies. The system presented in the case study incorporates agents in Arduino hardware devices with recognition modules and illuminated bands; it also incorporates IP cameras programmed for automatic tracking, which can connect remotely in the event of emergencies. The user wears a bracelet, which contains a simple vibration sensor that can receive notifications about the emergency situation.

Ambient Agents: Embedded Agents for Remote Control and Monitoring Using the PANGEA Platform

PubMed Central

Villarrubia, Gabriel; De Paz, Juan F.; Bajo, Javier; Corchado, Juan M.

2014-01-01

Ambient intelligence has advanced significantly during the last few years. The incorporation of image processing and artificial intelligence techniques have opened the possibility for such aspects as pattern recognition, thus allowing for a better adaptation of these systems. This study presents a new model of an embedded agent especially designed to be implemented in sensing devices with resource constraints. This new model of an agent is integrated within the PANGEA (Platform for the Automatic Construction of Organiztions of Intelligent Agents) platform, an organizational-based platform, defining a new sensor role in the system and aimed at providing contextual information and interacting with the environment. A case study was developed over the PANGEA platform and designed using different agents and sensors responsible for providing user support at home in the event of incidents or emergencies. The system presented in the case study incorporates agents in Arduino hardware devices with recognition modules and illuminated bands; it also incorporates IP cameras programmed for automatic tracking, which can connect remotely in the event of emergencies. The user wears a bracelet, which contains a simple vibration sensor that can receive notifications about the emergency situation. PMID:25090416

Physics-based agent to simulant correlations for vapor phase mass transport.

PubMed

Willis, Matthew P; Varady, Mark J; Pearl, Thomas P; Fouse, Janet C; Riley, Patrick C; Mantooth, Brent A; Lalain, Teri A

2013-12-15

Chemical warfare agent simulants are often used as an agent surrogate to perform environmental testing, mitigating exposure hazards. This work specifically addresses the assessment of downwind agent vapor concentration resulting from an evaporating simulant droplet. A previously developed methodology was used to estimate the mass diffusivities of the chemical warfare agent simulants methyl salicylate, 2-chloroethyl ethyl sulfide, di-ethyl malonate, and chloroethyl phenyl sulfide. Along with the diffusivity of the chemical warfare agent bis(2-chloroethyl) sulfide, the simulant diffusivities were used in an advection-diffusion model to predict the vapor concentrations downwind from an evaporating droplet of each chemical at various wind velocities and temperatures. The results demonstrate that the simulant-to-agent concentration ratio and the corresponding vapor pressure ratio are equivalent under certain conditions. Specifically, the relationship is valid within ranges of measurement locations relative to the evaporating droplet and observation times. The valid ranges depend on the relative transport properties of the agent and simulant, and whether vapor transport is diffusion or advection dominant. Published by Elsevier B.V.

Iodine-131 induced hepatotoxicity in previously healthy patients with Grave's disease.

PubMed

Jhummon, Navina Priya; Tohooloo, Bhavna; Qu, Shen

2013-01-01

To describe the association of the rare and serious complication of liver toxicity in previously healthy Grave's disease (GD) patients after the treatment with radioactive iodine (131)I (RAI). We report the clinical, laboratory and pathologic findings of 2 cases of severe liver toxicity associated with the treatment with RAI in previously healthy patients with GD. Clinical examination and laboratory investigations excluded viral hepatitis, autoimmune hepatitis, granulomatous disease, primary biliary disease, extrahepatic biliary obstruction, and heart failure. Case 1: A previously healthy 52-years old man reportedly having a typical GD but following RAI treatment, concomitantly developed severe liver toxicity that required 1 week of treatment in hospital. Case 2: A previously healthy 34-years old woman is reported as having a typical GD but developed jaundice following RAI treatment that required several weeks of in hospital treatment in the hepato-biliary department. In both cases, the liver dysfunction resolved after intensive treatment with hepato-protective agents. In this report the therapeutic considerations as well as the pathogenetic possibilities are reviewed. To the best of our knowledge, this is the first description of the association observed, which is rare but may be severe and should be considered in any case of thyrotoxicosis where a liver dysfunction develops after the treatment with radioactive iodine (131)I.

Alpha-hydroxyacid chemical peeling agents: case studies and rationale for safe and effective use.

PubMed

Briden, M Elizabeth

2004-02-01

Chemical peeling is an in-office procedure that involves the application of a chemical agent to the skin to induce controlled destruction or exfoliation of old skin and stimulation of new epidermal growth with more evenly distributed melanin. When peel agents reach the dermal layer, important wound-healing activities occur that cause skin remodeling and skin smoothing, both antiaging benefits. There are a number of key factors in selecting a peeling agent and procedure, and each is discussed. Variables to consider are the peeling agent and its formulation, the concentration of the agent, the patient's skin type, the site to be peeled, the skin preparation procedure prior to and immediately preceding the application of the agent, the application method, the duration of contact, and the patient's medical history and lifestyle. Various types of peels are discussed. Of particular interest are superficial chemical peels, which offer great flexibility over a range of skin types and conditions with minimal to no "downtime." Alpha-hydroxyacid (AHA) peels are superficial and can be combined with other cosmetic procedures in the office to maximize benefits. In addition, AHA peels work well when combined with supportive homecare products including AHAs or polyhydroxy acids (PHAs), topical retinoids, and antiacne/antirosacea treatments. Case studies are presented of patients using AHA peels for the treatment of acne and hyperpigmentation in a variety of skin types, including Asian skin.

Agent-Based vs. Equation-based Epidemiological Models:A Model Selection Case Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sukumar, Sreenivas R; Nutaro, James J

This paper is motivated by the need to design model validation strategies for epidemiological disease-spread models. We consider both agent-based and equation-based models of pandemic disease spread and study the nuances and complexities one has to consider from the perspective of model validation. For this purpose, we instantiate an equation based model and an agent based model of the 1918 Spanish flu and we leverage data published in the literature for our case- study. We present our observations from the perspective of each implementation and discuss the application of model-selection criteria to compare the risk in choosing one modeling paradigmmore » to another. We conclude with a discussion of our experience and document future ideas for a model validation framework.« less

The application of embodied conversational agents for mentoring African American STEM doctoral students

NASA Astrophysics Data System (ADS)

Gosha, Kinnis

This dissertation presents the design, development and short-term evaluation of an embodied conversational agent designed to mentor human users. An embodied conversational agent (ECA) was created and programmed to mentor African American computer science majors on their decision to pursue graduate study in computing. Before constructing the ECA, previous research in the fields of embodied conversational agents, relational agents, mentorship, telementorship and successful mentoring programs and practices for African American graduate students were reviewed. A survey used to find areas of interest of the sample population. Experts were then interviewed to collect information on those areas of interest and a dialogue for the ECA was constructed based on the interview's transcripts. A between-group, mixed method experiment was conducted with 37 African American male undergraduate computer science majors where one group used the ECA mentor while the other group pursued mentoring advice from a human mentor. Results showed no significant difference between the ECA and human mentor when dealing with career mentoring functions. However, the human mentor was significantly better than the ECA mentor when addressing psychosocial mentoring functions.

Clinicopathological features of mycosis fungoides in patients exposed to Agent Orange during the Vietnam War.

PubMed

Jang, Min Soo; Jang, Jun Gyu; Han, Sang Hwa; Park, Jong Bin; Kang, Dong Young; Kim, Sang Tae; Suh, Kee Suck

2013-08-01

There are no reports on the clinicopathological features of mycosis fungoides (MF) among veterans exposed to Agent Orange, one of the herbicides used during the Vietnam War. To evaluate the clinical, histopathological and genotypic findings of Vietnam War veterans with MF and a positive history of exposure to Agent Orange, we performed a comparative clinicopathological study between MF patients with a history of Agent Orange exposure and those without a history of Agent Orange exposure. Twelve Vietnam War veterans with MF were identified. The mean interval from Agent Orange exposure to diagnosis was 24.5 years (range, 9-35). Skin lesions were significantly present on exposed and unexposed areas. Most patients (75%) experienced pruritus (mean visual analog scale score of 6.7). MF was manifested by plaques in 10 patients and by lichenification in five. Histopathological features of most cases were consistent with MF. Biopsy specimens also demonstrated irregular acanthosis (66.7%). In the comparative study, MF patients with a history of Agent Orange exposure differed significantly from those without exposure to Agent Orange in demographic and clinical characteristics. In addition, patients with exposure had an increased tendency for lesions in the exposed area. Notably, our patients showed a higher frequency (33.3%) of mycosis fungoides palmaris et plantaris than in previous studies. Histologically, irregular acanthosis was more frequently observed than ordinary MF. Our results indicate that dermatologists should pay close attention to these clinicopathological differences. Careful assessment of history of exposure to defoliants is warranted in some cases suspicious for MF. © 2013 Japanese Dermatological Association.

Safety and activity of temsirolimus and bevacizumab in patients with advanced renal cell carcinoma previously treated with tyrosine kinase inhibitors: a phase 2 consortium study.

PubMed

Merchan, Jaime R; Qin, Rui; Pitot, Henry; Picus, Joel; Liu, Glenn; Fitch, Tom; Maples, William J; Flynn, Patrick J; Fruth, Briant F; Erlichman, Charles

2015-03-01

Bevacizumab or temsirolimus regimens have clinical activity in the first-line treatment of advanced renal cell carcinoma (RCC). This phase I/II trial was conducted to determine the safety of combining both agents and its efficacy in RCC patients who progressed on at least one prior anti-VEGF receptor tyrosine kinase inhibitor (RTKI) agent. In the phase I portion, eligible patients were treated with temsirolimus (25 mg IV weekly) and escalating doses of IV bevacizumab (level 1 = 5 mg/kg; level 2 = 10 mg/kg) every other week. The primary endpoint for the phase II portion (RTKI resistant patients) was the 6-month progression-free rate. Secondary endpoints were response rate, toxicity evaluation, and PFS and OS. Maximum tolerated dose was not reached at the maximum dose administered in 12 phase I patients. Forty evaluable patients were treated with the phase II recommended dose (temsirolimus 25 mg IV weekly and bevacizumab 10 mg/kg IV every 2 weeks). The 6-month progression-free rate was 40 % (16/40 pts). Median PFS was 5.9 (4-7.8) months, and median OS was 20.6 (11.5-23.7) months. Partial response, stable disease, and progressive disease were seen in 23, 63, and 14 % of patients, respectively. Most common grade 3-4 AEs included fatigue (17.8 %), hypertriglyceridemia (11.1 %), stomatitis (8.9 %), proteinuria (8.9 %), abdominal pain (6.7 %), and anemia (6.7 %). Baseline levels of serum sFLT-1 and VEGF-A were inversely correlated with PFS and OS, respectively. Temsirolimus and bevacizumab is a feasible combination in patients with advanced RCC previously exposed to oral anti-VEGF agents. The safety and efficacy results warrant further confirmatory studies in this patient population.

SAFETY AND ACTIVITY OF TEMSIROLIMUS AND BEVACIZUMAB IN PATIENTS WITH ADVANCED RENAL CELL CARCINOMA PREVIOUSLY TREATED WITH TYROSINE KINASE INHIBITORS: A PHASE 2 CONSORTIUM STUDY

PubMed Central

Merchan, Jaime R.; Qin, Rui; Pitot, Henry; Picus, Joel; Liu, Glenn; Fitch, Tom; Maples, William J.; Flynn, Patrick J.; Fruth, Briant F.; Erlichman, Charles

2015-01-01

Purpose Bevacizumab or Temsirolimus regimens have clinical activity in the first line treatment of advanced renal cell carcinoma (RCC). This phase I/II trial was conducted to determine the safety of combining both agents and its efficacy in RCC patients who progressed on at least one prior anti-VEGF receptor tyrosine kinase inhibitor (RTKI) agent. Methods In the phase I portion, eligible patients were treated with Temsirolimus (25 mg IV weekly) and escalating doses of IV Bevacizumab (level 1=5mg/kg; level 2=10 mg/kg) every other week. The primary endpoint for the phase II portion (RTKI resistant patients) was the 6-month progression free rate. Secondary endpoints were response rate, toxicity evaluation, PFS and OS. Results MTD was not reached at the maximum dose administered in 12 phase I patients. Forty evaluable patients were treated with the phase II recommended dose (Temsirolimus 25 mg IV weekly and Bevacizumab 10 mg/kg IV every two weeks). The 6-month progression free rate was 40% (16/40 pts). Median PFS was 5.9 (4-7.8) months, and median OS was 20.6 (11.5-23.7) months. Partial response/stable/progressive disease were seen in 23%/63%/14% of patients. Most common grade 3-4 AEs included fatigue (17.8%), hypertriglyceridemia (11.1%), stomatitis (8.9%), proteinuria (8.9%), abdominal pain (6.7%), and anemia (6.7%). Baseline levels of serum sFLT-1 and VEGF-A were inversely correlated with PFS and OS, respectively. Conclusions Temsirolimus and Bevacizumab is a feasible combination in patients with advanced RCC previously exposed to oral anti-VEGF agents. The safety and efficacy results warrant further confirmatory studies in this patient population. PMID:25556030

Safe motion planning for mobile agents: A model of reactive planning for multiple mobile agents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fujimura, Kikuo.

1990-01-01

The problem of motion planning for multiple mobile agents is studied. Each planning agent independently plans its own action based on its map which contains a limited information about the environment. In an environment where more than one mobile agent interacts, the motions of the robots are uncertain and dynamic. A model for reactive agents is described and simulation results are presented to show their behavior patterns. 18 refs., 2 figs.

Impact of Various Irrigating Agents on Root Fracture: An in vitro Study.

PubMed

Tiwari, Sukriti; Nikhade, Pradnya; Chandak, Manoj; Sudarshan, C; Shetty, Priyadarshini; Gupta, Naveen K

2016-08-01

Irrigating solutions are used for cleaning and removing dentinal debris, and the other remains from pulpal space during biomechanical preparation. Therefore, we evaluated the impact of various irrigating agents on root fracture at 5-minute time exposure. We sectioned 60 permanent maxillary premolars with fully formed root structures transversely maintaining the root length of approximately 14 mm. Five study groups were made comprising ethylenediaminetetraacetic acid (EDTA), cetrimide, citric acid, and so on as various irrigating agents. A universal force test machine was used to calculate the force which was enough to fracture each root. Analysis of variance (ANOVA) test was used to access the level of significance. About 10% citric acid solution as an irrigating agent showed minimal fracture opposing results, whereas 10% EDTA solution showed the maximum fracture resistance of root portion. Selection of suitable EDTA concentration that has minimal adverse effect on the mechanical properties of the tooth is very important for the successful management of tooth fracture. About 10% EDTA provided the highest fracture resistance, necessitating the use of irrigating solution in root canal therapy (RCT). Further research with higher and different study groups is required to search for more efficient irrigating solution to improve the outcome of RCT.

A case-crossover study of transient risk factors influence on occupational injuries: a study protocol based on a review of previous studies.

PubMed

Oesterlund, Anna H; Lander, Flemming; Lauritsen, Jens

2016-10-01

The occupational injury incident rate remains relatively high in the European Union. The case-crossover study gives a unique opportunity to study transient risk factors that normally would be very difficult to approach. Studies like this have been carried out in both America and Asia, but so far no relevant research has been conducted in Europe. Case-crossover studies of occupational injuries were collected from PubMed and Embase and read through. Previous experiences concerning method, exposure and outcome, time-related measurements and construction of the questionnaire were taken into account in the preparation of a pilot study. Consequently, experiences from the pilot study were used to design the study protocol. Approximately 2000 patients with an occupational injury will be recruited from the emergency departments in Herning and Odense, Denmark. A standardised questionnaire will be used to collect basic demographic data and information on eight transient risk factors. Based on previous studies and knowledge on occupational injuries the transient risk factors we chose to examine were: time pressure, performing a task with a different method/using unaccustomed technique, change in working surroundings, using a phone, disagreement, feeling ill, being distracted and using malfunctioning machinery/tools or work material. Exposure time 'just before the injury' will be compared with two control periods, 'previous day at the same time of the injury' (pair match) and the previous work week (usual frequency). This study protocol describes a unique opportunity to calculate the effect of transient risk factors on occupational injuries in a European setting. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

A comparative study of different bleaching agents on the morphology of human enamel: an in vitro SEM study.

PubMed

Uthappa, Roshan; Suprith, M L; Bhandary, Shreetha; Dash, Sumit

2012-11-01

The purpose of the study was to compare two different commercial bleaching agents, Opalescence with Colgate Platinum, and 30% phosphoric acid used as aggressive agent on the morphology of human enamel. Ten freshly extracted, noncarious, human maxillary central incisors extracted for periodontal reasons were used in this study. The labial surface of the disinfected teeth were polished using a polishing paste with the help of rubber cup and a slow speed handpiece. Each tooth was sectioned at cement-enamel junction and the crown was separated into four specimens, all taken from labial surface. Group 1 was treated with Colgate Platinum for 7 hours, group 2 with Opalescence for 7 hours, group 3 was treated with 30% phosphoric acid for 30 seconds and group 4 was untreated and used as control. After the treatment period, the specimens were washed with normal saline and stored in sterile bottle and sealed. Photomicrographs obtained from the scanning electron microscopy (SEM) after surface treatments were examined for no alteration, slight alteration, moderate alteration and severe alterations. The specimens treated with commercial bleaching agents revealed no enamel surface morphologic alterations compared to control group. The specimen treated with phosphoric acid showed severe alterations. Ten percent carbamide peroxide evaluated in this study does not etch tooth enamel or alter enamel surface morphology as do conventional etching techniques. Carbamine peroxide is a safe and effective tooth whitening agent even when used for extended period of time. The enamel surface remains smooth which reduces caries due to plaque collection.

Chlamydia gallinacea: a widespread emerging Chlamydia agent with zoonotic potential in backyard poultry.

PubMed

Li, L; Luther, M; Macklin, K; Pugh, D; Li, J; Zhang, J; Roberts, J; Kaltenboeck, B; Wang, C

2017-10-01

Chlamydia gallinacea, a new chlamydial agent, has been reported in four European countries as well as Argentina and China. Experimentally infected chickens with C. gallinacea in previous study showed no clinical signs but had significantly reduced gains in body weight (6·5-11·4%). Slaughterhouse workers exposed to infected chickens have developed atypical pneumonia, indicating C. gallinacea is likely a zoonotic agent. In this study, FRET-PCR confirmed that C. gallinacea was present in 12·4% (66/531) of oral-pharyngeal samples from Alabama backyard poultry. Phylogenetic comparisons based on ompA variable domain showed that 16 sequenced samples represented 14 biotypes. We report for the first time the presence of C. gallinacea in North America, and this warrants further research on the organism's pathogenicity, hosts, transmission, and zoonotic potential.

A study on agent-based secure scheme for electronic medical record system.

PubMed

Chen, Tzer-Long; Chung, Yu-Fang; Lin, Frank Y S

2012-06-01

Patient records, including doctors' diagnoses of diseases, trace of treatments and patients' conditions, nursing actions, and examination results from allied health profession departments, are the most important medical records of patients in medical systems. With patient records, medical staff can instantly understand the entire medical information of a patient so that, according to the patient's conditions, more accurate diagnoses and more appropriate in-depth treatments can be provided. Nevertheless, in such a modern society with booming information technologies, traditional paper-based patient records have faced a lot of problems, such as lack of uniform formats, low data mobility, slow data transfer, illegible handwritings, enormous and insufficient storage space, difficulty of conservation, being easily damaged, and low transferability. To improve such drawbacks, reduce medical costs, and advance medical quality, paper-based patient records are modified into electronic medical records and reformed into electronic patient records. However, since electronic patient records used in various hospitals are diverse and different, in consideration of cost, it is rather difficult to establish a compatible and complete integrated electronic patient records system to unify patient records from heterogeneous systems in hospitals. Moreover, as the booming of the Internet, it is no longer necessary to build an integrated system. Instead, doctors can instantly look up patients' complete information through the Internet access to electronic patient records as well as avoid the above difficulties. Nonetheless, the major problem of accessing to electronic patient records cross-hospital systems exists in the security of transmitting and accessing to the records in case of unauthorized medical personnels intercepting or stealing the information. This study applies the Mobile Agent scheme to cope with the problem. Since a Mobile Agent is a program, which can move among hosts and

QUICR-learning for Multi-Agent Coordination

NASA Technical Reports Server (NTRS)

Agogino, Adrian K.; Tumer, Kagan

2006-01-01

Coordinating multiple agents that need to perform a sequence of actions to maximize a system level reward requires solving two distinct credit assignment problems. First, credit must be assigned for an action taken at time step t that results in a reward at time step t > t. Second, credit must be assigned for the contribution of agent i to the overall system performance. The first credit assignment problem is typically addressed with temporal difference methods such as Q-learning. The second credit assignment problem is typically addressed by creating custom reward functions. To address both credit assignment problems simultaneously, we propose the "Q Updates with Immediate Counterfactual Rewards-learning" (QUICR-learning) designed to improve both the convergence properties and performance of Q-learning in large multi-agent problems. QUICR-learning is based on previous work on single-time-step counterfactual rewards described by the collectives framework. Results on a traffic congestion problem shows that QUICR-learning is significantly better than a Q-learner using collectives-based (single-time-step counterfactual) rewards. In addition QUICR-learning provides significant gains over conventional and local Q-learning. Additional results on a multi-agent grid-world problem show that the improvements due to QUICR-learning are not domain specific and can provide up to a ten fold increase in performance over existing methods.

A Retrospective Case-Control Study Evaluating the Role of Mifepristone for Induction of Labor in Women with Previous Cesarean Section.

PubMed

Sharma, Chanderdeep; Soni, Anjali; Soni, Pawan K; Verma, Suresh; Verma, Ashok; Gupta, Amit

2016-10-01

To investigate the role of "mifepristone" for induction of labor (IOL) in pregnant women with prior cesarean section (CS). In this retrospective study, all pregnant women with prior CS who received oral mifepristone (400 mg) for IOL (as per clear obstetric indications) [group 1] were compared with pregnant women with prior CS who had spontaneous onset of labor (SOL) [group 2], with respect to incidence of vaginal delivery, CS, duration of labor, and various maternal and fetal outcomes. During the study period, 72 women received mifepristone (group 1) for IOL and 346 had SOL (group 2). In group 1 after mifepristone administration, 40 (55.6 %) women had labor onset, and 24 (33.3 %) women had cervical ripening (Bishop Score ≥ 8) within 48 h. There were no statistically significant differences with respect to duration of labor (p value: 0.681), mode of delivery (i.e., normal delivery or CS-p value: 0.076 or 0.120, respectively), or maternal (blood loss or scar dehiscence/rupture uterus), or fetal outcomes (NICU admission) compared to women with previous CS with SOL (group 2). However, the need of oxytocin (p value 0.020) and dose of oxytocin requirement (p value 0.008) were more statistically significant in group 1. Mifepristone may be considered as an agent for IOL in women with prior CS.

Influence of bleaching agents on surface roughness of sound or eroded dental enamel specimens.

PubMed

Azrak, Birgül; Callaway, Angelika; Kurth, Petra; Willershausen, Brita

2010-12-01

The aim of the present in vitro study was to assess the effect of bleaching agents on eroded and sound enamel specimens. Enamel specimens prepared from human permanent anterior teeth were incubated with different bleaching agents containing active ingredients as 7.5 or 13.5% hydrogen peroxide or 35% carbamide peroxide, ranging in pH from 4.9 to 10.8. The effect of the tooth whitening agents on surface roughness was tested for sound enamel surfaces as well as for eroded enamel specimens. To provoke erosive damage, the enamel specimens were incubated for 10 hours with apple juice (pH = 3.4). Afterwards, pretreated and untreated dental slices were incubated with one of the bleaching agents for 10 hours. The surface roughness (R(a)) of all enamel specimens (N = 80) was measured using an optical profilometric device. A descriptive statistical analysis of the R(a) values was performed. The study demonstrated that exposure to an acidic bleaching agent (pH = 4.9) resulted in a higher surface roughness (p = 0.043) than treatment with a high peroxide concentration (pH = 6.15). If the enamel surface was previously exposed to erosive beverages, subsequent bleaching may enhance damage to the dental hard tissue. Bleaching agents with a high concentration of peroxide or an acidic pH can influence the surface roughness of sound or eroded enamel. © 2010, COPYRIGHT THE AUTHORS. JOURNAL COMPILATION © 2010, WILEY PERIODICALS, INC.

The effects of previous open renal stone surgery types on PNL outcomes

PubMed Central

Ozgor, Faruk; Kucuktopcu, Onur; Ucpinar, Burak; Sarilar, Omer; Erbin, Akif; Yanaral, Fatih; Sahan, Murat; Binbay, Murat

2016-01-01

Introduction: Our aim was to demonstrate the effect of insicion of renal parenchyma during open renal stone surgery (ORSS) on percutaneous nephrolithotomy (PNL) outcomes. Methods: Patients with history of ORSS who underwent PNL operation between June 2005 and June 2015 were analyzed retrospectively. Patients were divided into two groups according to their type of previous ORSS. Patients who had a history of ORSS with parenchymal insicion, such as radial nephrotomies, anatrophic nephrolithotomy, lower pole resection, and partial nephrectomy, were included in Group 1. Other patients with a history of open pyelolithotomy were enrolled in Group 2. Preoperative characteristics, perioperative data, stone-free status, and complications were compared between the groups. Stone-free status was defined as complete clearance of stone(s) or presence of residual fragments smaller than 4 mm. The retrospective nature of our study, different experience level of surgeons, and lack of the evaluation of anesthetic agents and cost of procedures were limitations of our study. Results: 123 and 111 patients were enrolled in Groups 1 and 2, respectively. Preoperative characteristics were similar between groups. In Group 1, the mean operative time was statistically longer than in Group 2 (p=0.013). Stone-free status was significantly higher in Group 2 than in Group 1 (p=0.027). Complication rates were similar between groups. Hemorrhage requiring blood transfusion was the most common complication in both groups (10.5% vs. 9.9%). Conclusions: Our study demonstrated that a history of previous ORSS with parenchymal insicion significantly reduces the success rates of PNL procedure. PMID:28255416

The effects of previous open renal stone surgery types on PNL outcomes.

PubMed

Ozgor, Faruk; Kucuktopcu, Onur; Ucpinar, Burak; Sarilar, Omer; Erbin, Akif; Yanaral, Fatih; Sahan, Murat; Binbay, Murat

2016-01-01

Our aim was to demonstrate the effect of insicion of renal parenchyma during open renal stone surgery (ORSS) on percutaneous nephrolithotomy (PNL) outcomes. Patients with history of ORSS who underwent PNL operation between June 2005 and June 2015 were analyzed retrospectively. Patients were divided into two groups according to their type of previous ORSS. Patients who had a history of ORSS with parenchymal insicion, such as radial nephrotomies, anatrophic nephrolithotomy, lower pole resection, and partial nephrectomy, were included in Group 1. Other patients with a history of open pyelolithotomy were enrolled in Group 2. Preoperative characteristics, perioperative data, stone-free status, and complications were compared between the groups. Stone-free status was defined as complete clearance of stone(s) or presence of residual fragments smaller than 4 mm. The retrospective nature of our study, different experience level of surgeons, and lack of the evaluation of anesthetic agents and cost of procedures were limitations of our study. 123 and 111 patients were enrolled in Groups 1 and 2, respectively. Preoperative characteristics were similar between groups. In Group 1, the mean operative time was statistically longer than in Group 2 (p=0.013). Stone-free status was significantly higher in Group 2 than in Group 1 (p=0.027). Complication rates were similar between groups. Hemorrhage requiring blood transfusion was the most common complication in both groups (10.5% vs. 9.9%). Our study demonstrated that a history of previous ORSS with parenchymal insicion significantly reduces the success rates of PNL procedure.

Integrated Agent-Based and Production Cost Modeling Framework for Renewable Energy Studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gallo, Giulia

The agent-based framework for renewable energy studies (ARES) is an integrated approach that adds an agent-based model of industry actors to PLEXOS and combines the strengths of the two to overcome their individual shortcomings. It can examine existing and novel wholesale electricity markets under high penetrations of renewables. ARES is demonstrated by studying how increasing levels of wind will impact the operations and the exercise of market power of generation companies that exploit an economic withholding strategy. The analysis is carried out on a test system that represents the Electric Reliability Council of Texas energy-only market in the year 2020.more » The results more realistically reproduce the operations of an energy market under different and increasing penetrations of wind, and ARES can be extended to address pressing issues in current and future wholesale electricity markets.« less

Mesoscopic Effects in an Agent-Based Bargaining Model in Regular Lattices

PubMed Central

Poza, David J.; Santos, José I.; Galán, José M.; López-Paredes, Adolfo

2011-01-01

The effect of spatial structure has been proved very relevant in repeated games. In this work we propose an agent based model where a fixed finite population of tagged agents play iteratively the Nash demand game in a regular lattice. The model extends the multiagent bargaining model by Axtell, Epstein and Young [1] modifying the assumption of global interaction. Each agent is endowed with a memory and plays the best reply against the opponent's most frequent demand. We focus our analysis on the transient dynamics of the system, studying by computer simulation the set of states in which the system spends a considerable fraction of the time. The results show that all the possible persistent regimes in the global interaction model can also be observed in this spatial version. We also find that the mesoscopic properties of the interaction networks that the spatial distribution induces in the model have a significant impact on the diffusion of strategies, and can lead to new persistent regimes different from those found in previous research. In particular, community structure in the intratype interaction networks may cause that communities reach different persistent regimes as a consequence of the hindering diffusion effect of fluctuating agents at their borders. PMID:21408019

Mesoscopic effects in an agent-based bargaining model in regular lattices.

PubMed

Poza, David J; Santos, José I; Galán, José M; López-Paredes, Adolfo

2011-03-09

The effect of spatial structure has been proved very relevant in repeated games. In this work we propose an agent based model where a fixed finite population of tagged agents play iteratively the Nash demand game in a regular lattice. The model extends the multiagent bargaining model by Axtell, Epstein and Young modifying the assumption of global interaction. Each agent is endowed with a memory and plays the best reply against the opponent's most frequent demand. We focus our analysis on the transient dynamics of the system, studying by computer simulation the set of states in which the system spends a considerable fraction of the time. The results show that all the possible persistent regimes in the global interaction model can also be observed in this spatial version. We also find that the mesoscopic properties of the interaction networks that the spatial distribution induces in the model have a significant impact on the diffusion of strategies, and can lead to new persistent regimes different from those found in previous research. In particular, community structure in the intratype interaction networks may cause that communities reach different persistent regimes as a consequence of the hindering diffusion effect of fluctuating agents at their borders.

[Study on expert system of infrared spectral characteristic of combustible smoke agent].

PubMed

Song, Dong-ming; Guan, Hua; Hou, Wei; Pan, Gong-pei

2009-05-01

The present paper studied the application of expert system in prediction of infrared spectral characteristic of combustible anti-infrared smoke agent. The construction of the expert system was founded, based on the theory of minimum free energy and infrared spectral addition. After the direction of smoke agent was input, the expert system could figure out the final combustion products. Then infrared spectrogram of smoke could also be simulated by adding the spectra of all of the combustion products. Meanwhile, the screening index of smoke was provided in the wave bands of 3-5 im and 8-14 microm. FTIR spectroscope was used to investigate the performance of one kind of HC smoke. The combustion products calculated by the expert system were coincident with the actual data, and the simulant infrared spectrum was also similar to the real one of the smoke. The screening index given by the system was consistent with the known facts. It was showed that a new approach was offered for the fast discrimination of varieties of directions of smoke agent.

Preparing Change Agents for Change Agent Roles.

ERIC Educational Resources Information Center

Sedlacek, James R.

Seventy-seven Spanish- and Portuguese-speaking agricultural change agents from developing Central and South American countries responded to a questionnaire which sought perceptions of the roles in which the change agents felt they were involved and the roles for which they felt they were being trained. The agents were participating in training…

Product Distribution Theory for Control of Multi-Agent Systems

NASA Technical Reports Server (NTRS)

Lee, Chia Fan; Wolpert, David H.

2004-01-01

Product Distribution (PD) theory is a new framework for controlling Multi-Agent Systems (MAS's). First we review one motivation of PD theory, as the information-theoretic extension of conventional full-rationality game theory to the case of bounded rational agents. In this extension the equilibrium of the game is the optimizer of a Lagrangian of the (probability distribution of) the joint stare of the agents. Accordingly we can consider a team game in which the shared utility is a performance measure of the behavior of the MAS. For such a scenario the game is at equilibrium - the Lagrangian is optimized - when the joint distribution of the agents optimizes the system's expected performance. One common way to find that equilibrium is to have each agent run a reinforcement learning algorithm. Here we investigate the alternative of exploiting PD theory to run gradient descent on the Lagrangian. We present computer experiments validating some of the predictions of PD theory for how best to do that gradient descent. We also demonstrate how PD theory can improve performance even when we are not allowed to rerun the MAS from different initial conditions, a requirement implicit in some previous work.

Use of antithrombotic agents in patients with intracerebral cavernous malformations.

PubMed

Flemming, Kelly D; Link, Michael J; Christianson, Teresa J H; Brown, Robert D

2013-01-01

The goal of this study was to determine the risk of using antithrombotic agents in patients with established intracerebral cavernous malformations (ICMs). From a previously described cohort of 292 patients with radiographically defined ICMs, 40 required an antithrombotic after the ICM was diagnosed. Patients underwent follow-up to determine the incidence of hemorrhage. The mean age of these 40 patients was 62.4 years; there were 21 male and 19 female patients. Five (12.5%) of the 40 patients initially presented with hemorrhage and 4 (10%) had multiple ICMs. Of these patients, 32 were placed on an antiplatelet agent alone, 6 on an anticoagulant alone, and 2 were placed on both. In patients necessitating any antithrombotic agent, 1 patient developed a prospective hemorrhage over the 258 person-years of follow-up (prospective hemorrhage rate 0.41% per person-year). Antithrombotics likely do not precipitate hemorrhage in patients with known ICMs. However, caution should be exercised in the use of antithrombotics in patients with ICMs at high risk for hemorrhage. The risks and benefits of antithrombotics in each situation should be carefully weighed against the natural history of ICM.

Control of Synchronization Regimes in Networks of Mobile Interacting Agents

NASA Astrophysics Data System (ADS)

Perez-Diaz, Fernando; Zillmer, Ruediger; Groß, Roderich

2017-05-01

We investigate synchronization in a population of mobile pulse-coupled agents with a view towards implementations in swarm-robotics systems and mobile sensor networks. Previous theoretical approaches dealt with range and nearest-neighbor interactions. In the latter case, a synchronization-hindering regime for intermediate agent mobility is found. We investigate the robustness of this intermediate regime under practical scenarios. We show that synchronization in the intermediate regime can be predicted by means of a suitable metric of the phase response curve. Furthermore, we study more-realistic K -nearest-neighbor and cone-of-vision interactions, showing that it is possible to control the extent of the synchronization-hindering region by appropriately tuning the size of the neighborhood. To assess the effect of noise, we analyze the propagation of perturbations over the network and draw an analogy between the response in the hindering regime and stable chaos. Our findings reveal the conditions for the control of clock or activity synchronization of agents with intermediate mobility. In addition, the emergence of the intermediate regime is validated experimentally using a swarm of physical robots interacting with cone-of-vision interactions.

Influence of anionic surface-active agents on the uptake of heavy metals by water hyacinth (Eichhornia crassipes)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muramoto, S.; Oki, Y.

1984-10-01

In a previous paper, the ability of water hyacinth to remove toxic heavy metals, cadmium, lead, and mercury, from a metal-containing solution was reported. However, information on the effects of surface-active agents on the metal uptake from waste water by water hyacinth is insufficient. Surface-active agents including anionic detergents have been found in lake, ponds, and rivers polluted by waste from industry and municipal sewage treatment plants. The present study examines the uptake of cadmium or nickel in the presence of the anionic detergent sodium dedecyl sulfate.

Change Agent Strategies: A Study of the Michigan-Ohio Regional Educational Laboratory.

ERIC Educational Resources Information Center

Miller, Peggy Lynne

This dissertation reports on a study of the planning and development activities of the Michigan-Ohio Regional Educational Laboratory (MOREL). The study attempted to assess (1) whether MOREL has accepted a change agent role, and (2) whether it has taken action that indicates recognition of what is known through the literature and research about…

[Alkylating agents].

PubMed

Pourquier, Philippe

2011-11-01

With the approval of mechlorethamine by the FDA in 1949 for the treatment of hematologic malignancies, alkylating agents are the oldest class of anticancer agents. Even though their clinical use is far beyond the use of new targeted therapies, they still occupy a major place in specific indications and sometimes represent the unique option for the treatment of refractory diseases. Here, we are reviewing the major classes of alkylating agents and their mechanism of action, with a particular emphasis for the new generations of alkylating agents. As for most of the chemotherapeutic agents used in the clinic, these compounds are derived from natural sources. With a complex but original mechanism of action, they represent new interesting alternatives for the clinicians, especially for tumors that are resistant to conventional DNA damaging agents. We also briefly describe the different strategies that have been or are currently developed to potentiate the use of classical alkylating agents, especially the inhibition of pathways that are involved in the repair of DNA lesions induced by these agents. In this line, the development of PARP inhibitors is a striking example of the recent regain of interest towards the "old" alkylating agents.

A cost effectiveness study of eribulin versus standard single-agent cytotoxic chemotherapy for women with previously treated metastatic breast cancer.

PubMed

Lopes, Gilberto; Glück, Stefan; Avancha, Kiran; Montero, Alberto J

2013-01-01

Eribulin was FDA approved in 2012 as a treatment for patients with MBC who have previously received at least two prior chemotherapy regimens. The aim of this analysis was to assess the cost effectiveness of eribulin versus the three most commonly utilized drugs (TPC) in the EMBRACE trial: vinorelbine, gemcitabine, and capecitabine (X); and to other branded FDA approved drugs: ixabepilone (I), liposomal-doxorubicin (D), and nab-paclitaxel. We created a decision-analytical and a Markov model using clinical data from the EMBRACE trial. Health utilities were derived from the published literature. Costs for drug acquisition, physician visits, and laboratory tests were obtained from Medicare Services Drug Payment Table and Physician Fee Schedule and are represented in 2012 USD. Life-years saved (LY), quality-adjusted life years (QALY), and incremental cost effectiveness ratio (ICER) were calculated. Eribulin added 0.208 LY and 0.119 QALY with an incremental cost over TPC of $25,458, and therefore an ICER of $213,742 per QALY. The main drivers of the model were drug cost, PFS, OS, and health utility values. The results of the model were robust in sensitivity analyses. Relative to I, D, A, and X, the ICER for eribulin was $76,823, $109,283, $129,773, and $167,267, respectively. Even with a more contemporary willingness-to-pay threshold of approximately $120,000 per QALY, eribulin was not found to be cost effective in the treatment of MBC relative to TPC; relative to some more expensive branded drugs, eribulin appears to be cost effective.

New agents for prostate cancer.

PubMed

Agarwal, N; Di Lorenzo, G; Sonpavde, G; Bellmunt, J

2014-09-01

The therapeutic landscape of metastatic castration-resistant prostate cancer (mCRPC) has been revolutionized by the arrival of multiple novel agents in the past 2 years. Immunotherapy in the form of sipuleucel-T, androgen axis inhibitors, including abiraterone acetate and enzalutamide, a chemotherapeutic agent, cabazitaxel, and a radiopharmaceutical, radium-223, have all yielded incremental extensions of survival and have been recently approved. A number of other agents appear promising in early studies, suggesting that the armamentarium against castrate-resistant prostate cancer is likely to continue to expand. Emerging androgen pathway inhibitors include androgen synthesis inhibitors (TAK700), androgen receptor inhibitors (ARN-509, ODM-201), AR DNA binding domain inhibitors (EPI-001), selective AR downregulators or SARDs (AZD-3514), and agents that inhibit both androgen synthesis and receptor binding (TOK-001/galeterone). Promising immunotherapeutic agents include poxvirus vaccines and CTLA-4 inhibitor (ipilimumab). Biologic agents targeting the molecular drivers of disease are also being investigated as single agents, including cabozantinib (Met and VEGFR2 inhibitor) and tasquinimod (angiogenesis and immune modulatory agent). Despite the disappointing results seen from studies evaluating docetaxel in combination with other agents, including GVAX, anti-angiogentic agents (bevacizumab, aflibercept, lenalinomide), a SRC kinase inhibitor (dasatinib), endothelin receptor antagonists (atrasentan, zibotentan), and high-dose calcitriol (DN-101), the results from the trial evaluating docetaxel in combination with the clusterin antagonist, custirsen, are eagerly awaited. New therapeutic hurdles consist of discovering new targets, understanding resistance mechanisms, the optimal sequencing and combinations of available agents, as well as biomarkers predictive for benefit. Novel agents targeting bone metastases are being developed following the success of zoledronic acid

Agent Reward Shaping for Alleviating Traffic Congestion

NASA Technical Reports Server (NTRS)

Tumer, Kagan; Agogino, Adrian

2006-01-01

Traffic congestion problems provide a unique environment to study how multi-agent systems promote desired system level behavior. What is particularly interesting in this class of problems is that no individual action is intrinsically "bad" for the system but that combinations of actions among agents lead to undesirable outcomes, As a consequence, agents need to learn how to coordinate their actions with those of other agents, rather than learn a particular set of "good" actions. This problem is ubiquitous in various traffic problems, including selecting departure times for commuters, routes for airlines, and paths for data routers. In this paper we present a multi-agent approach to two traffic problems, where far each driver, an agent selects the most suitable action using reinforcement learning. The agent rewards are based on concepts from collectives and aim to provide the agents with rewards that are both easy to learn and that if learned, lead to good system level behavior. In the first problem, we study how agents learn the best departure times of drivers in a daily commuting environment and how following those departure times alleviates congestion. In the second problem, we study how agents learn to select desirable routes to improve traffic flow and minimize delays for. all drivers.. In both sets of experiments,. agents using collective-based rewards produced near optimal performance (93-96% of optimal) whereas agents using system rewards (63-68%) barely outperformed random action selection (62-64%) and agents using local rewards (48-72%) performed worse than random in some instances.

Disease-associated prion protein detected in lymphoid tissues from pigs challenged with the agent of chronic wasting disease

USDA-ARS?s Scientific Manuscript database

Aims: Chronic wasting disease (CWD) is a naturally-occurring, fatal neurodegenerative disease of cervids. We previously demonstrated that disease-associated prion protein (PrPSc) can be detected in the brain and retina from pigs challenged intracranially or orally with the CWD agent. In that study,...

Element-specific spectral imaging of multiple contrast agents: a phantom study

NASA Astrophysics Data System (ADS)

Panta, R. K.; Bell, S. T.; Healy, J. L.; Aamir, R.; Bateman, C. J.; Moghiseh, M.; Butler, A. P. H.; Anderson, N. G.

2018-02-01

This work demonstrates the feasibility of simultaneous discrimination of multiple contrast agents based on their element-specific and energy-dependent X-ray attenuation properties using a pre-clinical photon-counting spectral CT. We used a photon-counting based pre-clinical spectral CT scanner with four energy thresholds to measure the X-ray attenuation properties of various concentrations of iodine (9, 18 and 36 mg/ml), gadolinium (2, 4 and 8 mg/ml) and gold (2, 4 and 8 mg/ml) based contrast agents, calcium chloride (140 and 280 mg/ml) and water. We evaluated the spectral imaging performances of different energy threshold schemes between 25 to 82 keV at 118 kVp, based on K-factor and signal-to-noise ratio and ranked them. K-factor was defined as the X-ray attenuation in the K-edge containing energy range divided by the X-ray attenuation in the preceding energy range, expressed as a percentage. We evaluated the effectiveness of the optimised energy selection to discriminate all three contrast agents in a phantom of 33 mm diameter. A photon-counting spectral CT using four energy thresholds of 27, 33, 49 and 81 keV at 118 kVp simultaneously discriminated three contrast agents based on iodine, gadolinium and gold at various concentrations using their K-edge and energy-dependent X-ray attenuation features in a single scan. A ranking method to evaluate spectral imaging performance enabled energy thresholds to be optimised to discriminate iodine, gadolinium and gold contrast agents in a single spectral CT scan. Simultaneous discrimination of multiple contrast agents in a single scan is likely to open up new possibilities of improving the accuracy of disease diagnosis by simultaneously imaging multiple bio-markers each labelled with a nano-contrast agent.

Dynamics of three-agent games

NASA Astrophysics Data System (ADS)

Mungan, Muhittin; Rador, Tonguç

2008-02-01

We study the dynamics and resulting score distribution of three-agent games where after each competition a single agent wins and scores a point. A single competition is described by a triplet of numbers p, t and q denoting the probabilities that the team with the highest, middle or lowest accumulated score wins. The three-agent game can be regarded as a social model where a player can be favored or disfavored for advancement, based on his/her accumulated score. We study the full family of solutions in the regime, where the number of agents and competitions is large, which can be regarded as a hydrodynamic limit. Depending on the parameter values (p, q, t), we find six qualitatively different asymptotic score distributions and we provide a qualitative explanation of these results. We also compare our analytical results against numerical simulations of the microscopic model and find these to be in excellent agreement. It is possible to decide the outcome of a three-agent game through a mini-tournament of two-agent competitions among the participating players and it turns out that the resulting possible score distributions are a subset of those obtained for the general three-agent games. We discuss how one can add a steady and democratic decline rate to the model and present a simple geometric construction that allows one to obtain the score evolution equations for n-agent games.

The value of less connected agents in Boolean networks

NASA Astrophysics Data System (ADS)

Epstein, Daniel; Bazzan, Ana L. C.

2013-11-01

In multiagent systems, agents often face binary decisions where one seeks to take either the minority or the majority side. Examples are minority and congestion games in general, i.e., situations that require coordination among the agents in order to depict efficient decisions. In minority games such as the El Farol Bar Problem, previous works have shown that agents may reach appropriate levels of coordination, mostly by looking at the history of past decisions. Not many works consider any kind of structure of the social network, i.e., how agents are connected. Moreover, when structure is indeed considered, it assumes some kind of random network with a given, fixed connectivity degree. The present paper departs from the conventional approach in some ways. First, it considers more realistic network topologies, based on preferential attachments. This is especially useful in social networks. Second, the formalism of random Boolean networks is used to help agents to make decisions given their attachments (for example acquaintances). This is coupled with a reinforcement learning mechanism that allows agents to select strategies that are locally and globally efficient. Third, we use agent-based modeling and simulation, a microscopic approach, which allows us to draw conclusions about individuals and/or classes of individuals. Finally, for the sake of illustration we use two different scenarios, namely the El Farol Bar Problem and a binary route choice scenario. With this approach we target systems that adapt dynamically to changes in the environment, including other adaptive decision-makers. Our results using preferential attachments and random Boolean networks are threefold. First we show that an efficient equilibrium can be achieved, provided agents do experimentation. Second, microscopic analysis show that influential agents tend to consider few inputs in their Boolean functions. Third, we have also conducted measurements related to network clustering and centrality

[Analytic study of foaming agents in imported beers].

PubMed

Scriban, R; Hebert, J P; Benard, M

1978-01-01

The French consumer expects a natural high-quality drink. It was therefore of interest to ascertain the quality of imported beers (they reached 2,440,000 hl in 1976, or 9.8 f. 100 of total sales) as well as how far their composition complies with present French legislation. Fifteen imported bottled beers were analyzed, from the following countries: West Germany, England, Belgium, Denmark, Luxemburg and the Netherlands. Attempts were first of all made to detect the presence in these beers of iron and cobalt, since both metals are recognized froth-improving agents. The search for cobalt produced negative results for all the beers. On the other hand we found that five of the 15 samples examined were questionable for their iron content (0.56--1.52 mg/l). We than looked for alginates in these imported beers, using a method comprising the following sequence of operations: concentration of the beer, dextrine hydrolysis, alginate precipitation at pH 5 by calcium chloride, treatment of the heated preparation with sodium hexametaphosphate, and colorimetric measurement at 670 nm with a reagent comprising orcinol, ferric sulfate and hydrochloric acid. In most of the 15 imported beers studied, the presence of alginates (up to 16.5 mg/l) was indisputable. The French consumer therefore has a right to expect the composition of foreign beers to comply with the French food laws, especially as regards the absence of frothing agents.

What makes virtual agents believable?

NASA Astrophysics Data System (ADS)

Bogdanovych, Anton; Trescak, Tomas; Simoff, Simeon

2016-01-01

In this paper we investigate the concept of believability and make an attempt to isolate individual characteristics (features) that contribute to making virtual characters believable. As the result of this investigation we have produced a formalisation of believability and based on this formalisation built a computational framework focused on simulation of believable virtual agents that possess the identified features. In order to test whether the identified features are, in fact, responsible for agents being perceived as more believable, we have conducted a user study. In this study we tested user reactions towards the virtual characters that were created for a simulation of aboriginal inhabitants of a particular area of Sydney, Australia in 1770 A.D. The participants of our user study were exposed to short simulated scenes, in which virtual agents performed some behaviour in two different ways (while possessing a certain aspect of believability vs. not possessing it). The results of the study indicate that virtual agents that appear resource bounded, are aware of their environment, own interaction capabilities and their state in the world, agents that can adapt to changes in the environment and exist in correct social context are those that are being perceived as more believable. Further in the paper we discuss these and other believability features and provide a quantitative analysis of the level of contribution for each such feature to the overall perceived believability of a virtual agent.

Delay-dependent coupling for a multi-agent LTI consensus system with inter-agent delays

NASA Astrophysics Data System (ADS)

Qiao, Wei; Sipahi, Rifat

2014-01-01

Delay-dependent coupling (DDC) is considered in this paper in a broadly studied linear time-invariant multi-agent consensus system in which agents communicate with each other under homogeneous delays, while attempting to reach consensus. The coupling among the agents is designed here as an explicit parameter of this delay, allowing couplings to autonomously adapt based on the delay value, and in order to guarantee stability and a certain degree of robustness in the network despite the destabilizing effect of delay. Design procedures, analysis of convergence speed of consensus, comprehensive numerical studies for the case of time-varying delay, and limitations are presented.

Docking Based 3D-QSAR Study of Tricyclic Guanidine Analogues of Batzelladine K as anti-malarial agents

NASA Astrophysics Data System (ADS)

Ahmed, Nafees; Anwar, Sirajudheen; Thet Htar, Thet

2017-06-01

The Plasmodium falciparum Lactate Dehydrogenase enzyme (PfLDH) catalyzes inter-conversion of pyruvate to lactate during glycolysis producing the energy required for parasitic growth. The PfLDH has been studied as a potential molecular target for development of anti-malarial agents. In an attempt to find the potent inhibitor of PfLDH, we have used Discovery studio to perform molecular docking in the active binding pocket of PfLDH by CDOCKER, followed by three-dimensional quantitative structure-activity relationship (3D-QSAR) studies of tricyclic guanidine batzelladine compounds, which were previously synthesized in our laboratory. Docking studies showed that there is a very strong correlation between in silico and in vitro results. Based on docking results, a highly predictive 3D-QSAR model was developed with q2 of 0.516. The model has predicted r2 of 0.91 showing that predicted IC50 values are in good agreement with experimental IC50 values. The results obtained from this study revealed the developed model can be used to design new anti-malarial compounds based on tricyclic guanidine derivatives and to predict activities of new inhibitors.

Docking Based 3D-QSAR Study of Tricyclic Guanidine Analogues of Batzelladine K As Anti-Malarial Agents.

PubMed

Ahmed, Nafees; Anwar, Sirajudheen; Thet Htar, Thet

2017-01-01

The Plasmodium falciparum Lactate Dehydrogenase enzyme ( Pf LDH) catalyzes inter-conversion of pyruvate to lactate during glycolysis producing the energy required for parasitic growth. The Pf LDH has been studied as a potential molecular target for development of anti-malarial agents. In an attempt to find the potent inhibitor of Pf LDH, we have used Discovery studio to perform molecular docking in the active binding pocket of Pf LDH by CDOCKER, followed by three-dimensional quantitative structure-activity relationship (3D-QSAR) studies of tricyclic guanidine batzelladine compounds, which were previously synthesized in our laboratory. Docking studies showed that there is a very strong correlation between in silico and in vitro results. Based on docking results, a highly predictive 3D-QSAR model was developed with q 2 of 0.516. The model has predicted r 2 of 0.91 showing that predicted IC 50 values are in good agreement with experimental IC 50 values. The results obtained from this study revealed the developed model can be used to design new anti-malarial compounds based on tricyclic guanidine derivatives and to predict activities of new inhibitors.

Docking Based 3D-QSAR Study of Tricyclic Guanidine Analogues of Batzelladine K As Anti-Malarial Agents

PubMed Central

Ahmed, Nafees; Anwar, Sirajudheen; Thet Htar, Thet

2017-01-01

The Plasmodium falciparum Lactate Dehydrogenase enzyme (PfLDH) catalyzes inter-conversion of pyruvate to lactate during glycolysis producing the energy required for parasitic growth. The PfLDH has been studied as a potential molecular target for development of anti-malarial agents. In an attempt to find the potent inhibitor of PfLDH, we have used Discovery studio to perform molecular docking in the active binding pocket of PfLDH by CDOCKER, followed by three-dimensional quantitative structure-activity relationship (3D-QSAR) studies of tricyclic guanidine batzelladine compounds, which were previously synthesized in our laboratory. Docking studies showed that there is a very strong correlation between in silico and in vitro results. Based on docking results, a highly predictive 3D-QSAR model was developed with q2 of 0.516. The model has predicted r2 of 0.91 showing that predicted IC50 values are in good agreement with experimental IC50 values. The results obtained from this study revealed the developed model can be used to design new anti-malarial compounds based on tricyclic guanidine derivatives and to predict activities of new inhibitors. PMID:28664157

A Generalized Quantum-Inspired Decision Making Model for Intelligent Agent

PubMed Central

Loo, Chu Kiong

2014-01-01

A novel decision making for intelligent agent using quantum-inspired approach is proposed. A formal, generalized solution to the problem is given. Mathematically, the proposed model is capable of modeling higher dimensional decision problems than previous researches. Four experiments are conducted, and both empirical experiments results and proposed model's experiment results are given for each experiment. Experiments showed that the results of proposed model agree with empirical results perfectly. The proposed model provides a new direction for researcher to resolve cognitive basis in designing intelligent agent. PMID:24778580

Relationship of deer and moose populations to previous winters' snow

USGS Publications Warehouse

Mech, L.D.; McRoberts, R.E.; Peterson, R.O.; Page, R.E.

1987-01-01

(1) Linear regression was used to relate snow accumulation during single and consecutive winters with white-tailed deer (Odocoileus virginianus) fawn:doe ratios, mosse (Alces alces) twinning rates and calf:cow ratios, and annual changes in deer and moose populations. Significant relationships were found between snow accumulation during individual winters and these dependent variables during the following year. However, the strongest relationships were between the dependent variables and the sums of the snow accumulations over the previous three winters. The percentage of the variability explained was 36 to 51. (2) Significant relationships were also found between winter vulnerability of moose calves and the sum of the snow accumulations in the current, and up to seven previous, winters, with about 49% of the variability explained. (3) No relationship was found between wolf numbers and the above dependent variables. (4) These relationships imply that winter influences on maternal nutrition can accumulate for several years and that this cumulative effect strongly determines fecundity and/or calf and fawn survivability. Although wolf (Canis lupus L.) predation is the main direct mortality agent on fawns and calves, wolf density itself appears to be secondary to winter weather in influencing the deer and moose populations.

Agents Play Mix-game

NASA Astrophysics Data System (ADS)

Gou, Chengling

In recent years, economics and finance see the shift of paradigm from representative agent models to heterogeneous agent models [1, 2]. More and more economists and physicists made efforts in research on heterogeneous agent models for financial markets. Minority game (MG) proposed by D. Challet, and Y. C. Zhang [3] is an example among such efforts. Challet and Zhang's MG model, together with the original bar model of Arthur, attracts a lot of following studies [4-6]. Given MG's richness and yet underlying simplicity, MG has also received much attention as a financial market model [4]. MG comprises an odd number of agents choosing repeatedly between the options of buying (1) and selling (0) a quantity of a risky asset. The agents continually try to make the minority decision, i.e. buy assets when the majority of other agents are selling, and sell when the majority of other agents are buying. Neil F. Johnson [4, 5] and coworkers extended MG by allowing a variable number of active traders at each timestep— they called their modified game as the Grand Canonical Minority Game (GCMG). GCMG, and to a lesser extent the basic MG itself, can reproduce the stylized facts of financial markets, such as volatility clustering and fat-tail distributions.

Indoor sorption of surrogates for sarin and related nerve agents.

PubMed

Singer, Brett C; Hodgson, Alfred T; Destaillats, Hugo; Hotchi, Toshifumi; Revzan, Kenneth L; Sextro, Richard G

2005-05-01

Sorption rate parameters were determined for three organophosphorus (OP) compounds [dimethyl methylphosphonate (DMMP), diethyl ethylphosphonate (DEEP), and triethyl phosphate (TEP)] as surrogates for the G-type nerve agents sarin (GB), soman (GD), and tabun (GA). OP surrogates were injected and vaporized with additional volatile organic compounds into a 50 m3 chamber finished with painted wallboard. Experiments were conducted at two furnishing levels: (i) chamber containing only hard surfaces including a desk, a bookcase, tables, and chairs and (ii) with the addition of plush materials including carpet with cushion, draperies, and upholstered furniture. Each furnishing level was studied with aged and new painted wallboard. Gas-phase concentrations were measured during sealed chamber adsorb and desorb phases and then fit to three mathematical variations of a previously proposed sorption model having a surface sink and allowing for an embedded sink. A four-parameter model allowing unequal transport rates between surface and embedded sinks provided excellent fits for all conditions. To evaluate the potential effect of sorption, this model was incorporated into an indoor air quality simulation model to predict indoor concentrations of a G-type agent and a nonsorbing agent for hypothetical outdoor releases with shelter-in-place (SIP) response. Sorption was simulated using a range of parameters obtained experimentally. Simulations considered outdoor Gaussian plumes of 1- and 5-h duration and infiltration rates of 0.1, 0.3, and 0.9 h(-1). Indoor toxic loads (TL) for a 10-h SIP were calculated as integral C2 dt for a G-type agent. For the 5-h plume, sheltering reduced TLs for the nonsorbing agent to approximately 10-65% of outdoor levels. Analogous TLs for a G-type agent were 2-31% or 0.3-12% of outdoor levels assuming slow or moderate sorption. The relative effect of sorption was more pronounced for the longer plume and higher infiltration rates.

Venetoclax in Patients with Previously Treated Chronic Lymphocytic Leukemia.

PubMed

Roberts, Andrew W; Stilgenbauer, Stephan; Seymour, John F; Huang, David C S

2017-08-15

Venetoclax is the first BCL2 inhibitor to enter routine clinical practice. It is an orally bioavailable small molecule that binds BCL2 very specifically. Acting as a pharmacologic mimic of the proteins that initiate apoptosis (a so-called BH3 mimetic), venetoclax rapidly induces apoptosis in chronic lymphocytic leukemia (CLL) cells, which express high levels of BCL2 and rely on it to maintain their survival. As a single agent, daily venetoclax treatment induced durable responses in 79% of patients with relapsed or refractory CLL or small lymphocytic lymphoma in a phase I study, including complete remissions in 20% of patients. Its use was approved by the FDA in April 2016 for patients with previously treated del(17p) CLL on the basis of a single-arm phase II trial demonstrating a 79% response rate and an estimated 1-year progression-free survival of 72% with 400 mg/day continuous therapy. This review focuses on venetoclax, its mechanism of action, pharmacology, and clinical trial data and seeks to place it in the context of rapid advances in therapy for patients with relapsed CLL, especially those with del(17p) CLL. Clin Cancer Res; 23(16); 4527-33. ©2017 AACR . ©2017 American Association for Cancer Research.

Iodine-131 induced hepatotoxicity in previously healthy patients with Grave’s disease

PubMed Central

2013-01-01

Objective To describe the association of the rare and serious complication of liver toxicity in previously healthy Grave’s disease (GD) patients after the treatment with radioactive iodine 131I (RAI). Case presentation We report the clinical, laboratory and pathologic findings of 2 cases of severe liver toxicity associated with the treatment with RAI in previously healthy patients with GD. Clinical examination and laboratory investigations excluded viral hepatitis, autoimmune hepatitis, granulomatous disease, primary biliary disease, extrahepatic biliary obstruction, and heart failure. Case 1: A previously healthy 52-years old man reportedly having a typical GD but following RAI treatment, concomitantly developed severe liver toxicity that required 1 week of treatment in hospital. Case 2: A previously healthy 34-years old woman is reported as having a typical GD but developed jaundice following RAI treatment that required several weeks of in hospital treatment in the hepato-biliary department. In both cases, the liver dysfunction resolved after intensive treatment with hepato-protective agents. In this report the therapeutic considerations as well as the pathogenetic possibilities are reviewed. Conclusion To the best of our knowledge, this is the first description of the association observed, which is rare but may be severe and should be considered in any case of thyrotoxicosis where a liver dysfunction develops after the treatment with radioactive iodine 131I. PMID:23497434

Characterization of chemical warfare G-agent hydrolysis products by surface-enhanced Raman spectroscopy

NASA Astrophysics Data System (ADS)

Inscore, Frank E.; Gift, Alan D.; Maksymiuk, Paul; Farquharson, Stuart

2004-12-01

The United States and its allies have been increasingly challenged by terrorism, and since the September 11, 2001 attacks and the war in Afghanistan and Iraq, homeland security has become a national priority. The simplicity in manufacturing chemical warfare agents, the relatively low cost, and previous deployment raises public concern that they may also be used by terrorists or rogue nations. We have been investigating the ability of surface-enhanced Raman spectroscopy (SERS) to detect extremely low concentrations (e.g. part-per-billion) of chemical agents, as might be found in poisoned water. Since trace quantities of nerve agents can be hydrolyzed in the presence of water, we have expanded our studies to include such degradation products. Our SERS-active medium consists of silver or gold nanoparticles incorporated into a sol-gel matrix, which is immobilized in a glass capillary. The choice of sol-gel precursor allows controlling hydrophobicity, while the porous silica network offers a unique environment for stabilizing the SERS-active metals. Here we present the use of these metal-doped sol-gels to selectively enhance the Raman signal of the hydrolyzed products of the G-series nerve agents.

Chemical warfare agents.

PubMed

Kuca, Kamil; Pohanka, Miroslav

2010-01-01

Chemical warfare agents are compounds of different chemical structures. Simple molecules such as chlorine as well as complex structures such as ricin belong to this group. Nerve agents, vesicants, incapacitating agents, blood agents, lung-damaging agents, riot-control agents and several toxins are among chemical warfare agents. Although the use of these compounds is strictly prohibited, the possible misuse by terrorist groups is a reality nowadays. Owing to this fact, knowledge of the basic properties of these substances is of a high importance. This chapter briefly introduces the separate groups of chemical warfare agents together with their members and the potential therapy that should be applied in case someone is intoxicated by these agents.

Sertraline versus other antidepressive agents for depression.

PubMed

Cipriani, Andrea; La Ferla, Teresa; Furukawa, Toshi A; Signoretti, Alessandra; Nakagawa, Atsuo; Churchill, Rachel; McGuire, Hugh; Barbui, Corrado

2010-04-14

The National Institute for Health and Clinical Excellence clinical practice guideline on the treatment of depressive disorder recommended that selective serotonin reuptake inhibitors should be the first-line option when drug therapy is indicated for a depressive episode. Preliminary evidence suggested that sertraline might be slightly superior in terms of effectiveness. To assess the evidence for the efficacy, acceptability and tolerability of sertraline in comparison with tricyclics (TCAs), heterocyclics, other SSRIs and newer agents in the acute-phase treatment of major depression. MEDLINE (1966 to 2008), EMBASE (1974 to 2008), the Cochrane Collaboration Depression, Anxiety and Neurosis Controlled Trials Register and the Cochrane Central Register of Controlled Trials up to July 2008. No language restriction was applied. Reference lists of relevant papers and previous systematic reviews were hand-searched. Pharmaceutical companies and experts in this field were contacted for supplemental data. Randomised controlled trials allocating patients with major depression to sertraline versus any other antidepressive agent. Two review authors independently extracted data. Discrepancies were resolved with another member of the team. A double-entry procedure was employed by two reviewers. Information extracted included study characteristics, participant characteristics, intervention details and outcome measures in terms of efficacy (the number of patients who responded or remitted), acceptability (the number of patients who failed to complete the study) and tolerability (side-effects). A total of 59 studies, mostly of low quality, were included in the review, involving multiple treatment comparisons between sertraline and other antidepressant agents. Evidence favouring sertraline over some other antidepressants for the acute phase treatment of major depression was found, either in terms of efficacy (fluoxetine) or acceptability/tolerability (amitriptyline, imipramine

Sertraline versus other antidepressive agents for depression.

PubMed

Cipriani, Andrea; La Ferla, Teresa; Furukawa, Toshi A; Signoretti, Alessandra; Nakagawa, Atsuo; Churchill, Rachel; McGuire, Hugh; Barbui, Corrado

2009-04-15

The National Institute for Health and Clinical Excellence clinical practice guideline on the treatment of depressive disorder recommended that selective serotonin reuptake inhibitors should be the first-line option when drug therapy is indicated for a depressive episode. Preliminary evidence suggested that sertraline might be slightly superior in terms of effectiveness. To assess the evidence for the efficacy, acceptability and tolerability of escitalopram in comparison with tricyclics (TCAs), heterocyclics, other SSRIs and newer agents in the acute-phase treatment of major depression. MEDLINE (1966 to 2008), EMBASE (1974 to 2008), the Cochrane Collaboration Depression, Anxiety and Neurosis Controlled Trials Register and the Cochrane Central Register of Controlled Trials up to July 2008. No language restriction was applied. Reference lists of relevant papers and previous systematic reviews were hand-searched. Pharmaceutical companies and experts in this field were contacted for supplemental data. Randomised controlled trials allocating patients with major depression to sertraline versus any other antidepressive agent. Two review authors independently extracted data. Discrepancies were resolved with another member of the team. A double-entry procedure was employed by two reviewers. Information extracted included study characteristics, participant characteristics, intervention details and outcome measures in terms of efficacy (the number of patients who responded or remitted), acceptability (the number of patients who failed to complete the study) and tolerability (side-effects). A total of 59 studies, mostly of low quality, were included in the review, involving multiple treatment comparisons between sertraline and other antidepressant agents. Evidence favouring sertraline over some other antidepressants for the acute phase treatment of major depression was found, either in terms of efficacy (fluoxetine) or acceptability/tolerability (amitriptyline, imipramine

Sertraline versus other antidepressive agents for depression.

PubMed

Cipriani, Andrea; La Ferla, Teresa; Furukawa, Toshi A; Signoretti, Alessandra; Nakagawa, Atsuo; Churchill, Rachel; McGuire, Hugh; Barbui, Corrado

2010-01-20

The National Institute for Health and Clinical Excellence clinical practice guideline on the treatment of depressive disorder recommended that selective serotonin reuptake inhibitors should be the first-line option when drug therapy is indicated for a depressive episode. Preliminary evidence suggested that sertraline might be slightly superior in terms of effectiveness. To assess the evidence for the efficacy, acceptability and tolerability of sertraline in comparison with tricyclics (TCAs), heterocyclics, other SSRIs and newer agents in the acute-phase treatment of major depression. MEDLINE (1966 to 2008), EMBASE (1974 to 2008), the Cochrane Collaboration Depression, Anxiety and Neurosis Controlled Trials Register and the Cochrane Central Register of Controlled Trials up to July 2008. No language restriction was applied. Reference lists of relevant papers and previous systematic reviews were hand-searched. Pharmaceutical companies and experts in this field were contacted for supplemental data. Randomised controlled trials allocating patients with major depression to sertraline versus any other antidepressive agent. Two review authors independently extracted data. Discrepancies were resolved with another member of the team. A double-entry procedure was employed by two reviewers. Information extracted included study characteristics, participant characteristics, intervention details and outcome measures in terms of efficacy (the number of patients who responded or remitted), acceptability (the number of patients who failed to complete the study) and tolerability (side-effects). A total of 59 studies, mostly of low quality, were included in the review, involving multiple treatment comparisons between sertraline and other antidepressant agents. Evidence favouring sertraline over some other antidepressants for the acute phase treatment of major depression was found, either in terms of efficacy (fluoxetine) or acceptability/tolerability (amitriptyline, imipramine

Sertraline versus other antidepressive agents for depression

PubMed Central

Cipriani, Andrea; La Ferla, Teresa; Furukawa, Toshi A; Signoretti, Alessandra; Nakagawa, Atsuo; Churchill, Rachel; McGuire, Hugh; Barbui, Corrado

2014-01-01

Background The National Institute for Health and Clinical Excellence clinical practice guideline on the treatment of depressive disorder recommended that selective serotonin reuptake inhibitors should be the first-line option when drug therapy is indicated for a depressive episode. Preliminary evidence suggested that sertraline might be slightly superior in terms of effectiveness. Objectives To assess the evidence for the efficacy, acceptability and tolerability of sertraline in comparison with tricyclics (TCAs), heterocyclics, other SSRIs and newer agents in the acute-phase treatment of major depression. Search methods MEDLINE (1966 to 2008), EMBASE (1974 to 2008), the Cochrane Collaboration Depression, Anxiety and Neurosis Controlled Trials Register and the Cochrane Central Register of Controlled Trials up to July 2008. No language restriction was applied. Reference lists of relevant papers and previous systematic reviews were hand-searched. Pharmaceutical companies and experts in this field were contacted for supplemental data. Selection criteria Randomised controlled trials allocating patients with major depression to sertraline versus any other antidepressive agent. Data collection and analysis Two review authors independently extracted data. Discrepancies were resolved with another member of the team. A double-entry procedure was employed by two reviewers. Information extracted included study characteristics, participant characteristics, intervention details and outcome measures in terms of efficacy (the number of patients who responded or remitted), acceptability (the number of patients who failed to complete the study) and tolerability (side-effects). Main results A total of 59 studies, mostly of low quality, were included in the review, involving multiple treatment comparisons between sertraline and other antidepressant agents. Evidence favouring sertraline over some other antidepressants for the acute phase treatment of major depression was found, either

A Chronic Longitudinal Characterization of Neurobehavioral and Neuropathological Cognitive Impairment in a Mouse Model of Gulf War Agent Exposure

PubMed Central

Zakirova, Zuchra; Crynen, Gogce; Hassan, Samira; Abdullah, Laila; Horne, Lauren; Mathura, Venkatarajan; Crawford, Fiona; Ait-Ghezala, Ghania

2016-01-01

Gulf War Illness (GWI) is a chronic multisymptom illness with a central nervous system component that includes memory impairment as well as neurological and musculoskeletal deficits. Previous studies have shown that in the First Persian Gulf War conflict (1990–1991) exposure to Gulf War (GW) agents, such as pyridostigmine bromide (PB) and permethrin (PER), were key contributors to the etiology of GWI. For this study, we used our previously established mouse model of GW agent exposure (10 days PB+PER) and undertook an extensive lifelong neurobehavioral characterization of the mice from 11 days to 22.5 months post exposure in order to address the persistence and chronicity of effects suffered by the current GWI patient population, 24 years post-exposure. Mice were evaluated using a battery of neurobehavioral testing paradigms, including Open Field Test (OFT), Elevated Plus Maze (EPM), Three Chamber Testing, Radial Arm Water Maze (RAWM), and Barnes Maze (BM) Test. We also carried out neuropathological analyses at 22.5 months post exposure to GW agents after the final behavioral testing. Our results demonstrate that PB+PER exposed mice exhibit neurobehavioral deficits beginning at the 13 months post exposure time point and continuing trends through the 22.5 month post exposure time point. Furthermore, neuropathological changes, including an increase in GFAP staining in the cerebral cortices of exposed mice, were noted 22.5 months post exposure. Thus, the persistent neuroinflammation evident in our model presents a platform with which to identify novel biological pathways, correlating with emergent outcomes that may be amenable to therapeutic targeting. Furthermore, in this work we confirmed our previous findings that GW agent exposure causes neuropathological changes, and have presented novel data which demonstrate increased disinhibition, and lack of social preference in PB+PER exposed mice at 13 months after exposure. We also extended upon our previous work to

Biological Agents

MedlinePlus

... E-Tools Safety and Health Topics / Biological Agents Biological Agents This page requires that javascript be enabled ... 202) 693-2300 if additional assistance is required. Biological Agents Menu Overview In Focus: Ebola Frederick A. ...

Modeling of a production system using the multi-agent approach

NASA Astrophysics Data System (ADS)

Gwiazda, A.; Sękala, A.; Banaś, W.

2017-08-01

The method that allows for the analysis of complex systems is a multi-agent simulation. The multi-agent simulation (Agent-based modeling and simulation - ABMS) is modeling of complex systems consisting of independent agents. In the case of the model of the production system agents may be manufactured pieces set apart from other types of agents like machine tools, conveyors or replacements stands. Agents are magazines and buffers. More generally speaking, the agents in the model can be single individuals, but you can also be defined as agents of collective entities. They are allowed hierarchical structures. It means that a single agent could belong to a certain class. Depending on the needs of the agent may also be a natural or physical resource. From a technical point of view, the agent is a bundle of data and rules describing its behavior in different situations. Agents can be autonomous or non-autonomous in making the decision about the types of classes of agents, class sizes and types of connections between elements of the system. Multi-agent modeling is a very flexible technique for modeling and model creating in the convention that could be adapted to any research problem analyzed from different points of views. One of the major problems associated with the organization of production is the spatial organization of the production process. Secondly, it is important to include the optimal scheduling. For this purpose use can approach multi-purposeful. In this regard, the model of the production process will refer to the design and scheduling of production space for four different elements. The program system was developed in the environment NetLogo. It was also used elements of artificial intelligence. The main agent represents the manufactured pieces that, according to previously assumed rules, generate the technological route and allow preprint the schedule of that line. Machine lines, reorientation stands, conveyors and transport devices also represent the

Evaluation of New Cleanup Agents for Analysis of Pesticide Residues in Tea.

PubMed

Ueda, Yuko; Honda, Katsuhisa

2017-01-01

We evaluated the effectiveness of new cleanup agents (S-NH 2 and S-Si) compared with other previously reported cleanup agents (octadecylsilane, graphitized carbon, aminopropyl and silica gel) for removal of interfering substances such as catechin and caffeine prior to analysis of pesticide residues in tea. S-NH 2 and S-Si were highly efficient in removal of catechin and caffeine, respectively. Recoveries of 80 pesticides using S-NH 2 and S-Si were tested, and more than 70% of pesticides showed recovery greater than 70%. These results indicate that S-NH 2 and S-Si agents will be useful for analysis of pesticide residues in tea.

Fluorescent and scattering contrast agents in a mouse model of colorectal cancer

NASA Astrophysics Data System (ADS)

Winkler, Amy M.; Rice, Photini F. S.; Troutman, Timothy S.; Backer, Marina V.; Backer, Joseph M.; Drezek, Rebekah A.; Romanowski, Marek; Barton, Jennifer K.

2008-02-01

In previous work we have demonstrated the utility of laser-induced fluorescence (LIF) and optical coherence tomography (OCT) to identify adenoma in mouse models of colorectal cancer with high sensitivity and specificity. However, improved sensitivity to early disease, as well as the ability to distinguish confounders (e.g. fecal contamination, natural variations in mucosal thickness), is desired. In this study, we investigated the signal enhancement of fluorescent and scattering contrast agents in the colons of AOM-treated mice. The fluorescent tracer scVEGF/Cy, targeted to receptors for vascular endothelial growth factor, was visualized on a dual modality OCT/LIF endoscopic system with 1300-nm center wavelength OCT source and 635-nm LIF excitation. Scattering agents were tested with an 890-nm center wavelength endoscopic OCT system. Agents included nanoshells, 120-nm in diameter, and nanorods, 20-nm in diameter by 80-nm in length. Following imaging, colons were excised. Tissue treated with fluorophore was imaged on an epifluorescence microscope. Histological sections were obtained and stained with H&E and silver enhancer to verify disease and identify regions of gold uptake, respectively. Non-specific signal enhancement was observed with the scattering contrast agents. Specificity for adenoma was seen with the scVEGF/Cy dye.

Do Low Molecular Weight Agents Cause More Severe Asthma than High Molecular Weight Agents?

PubMed

Meca, Olga; Cruz, María-Jesús; Sánchez-Ortiz, Mónica; González-Barcala, Francisco-Javier; Ojanguren, Iñigo; Munoz, Xavier

2016-01-01

The aim of this study was to analyse whether patients with occupational asthma (OA) caused by low molecular weight (LMW) agents differed from patients with OA caused by high molecular weight (HMW) with regard to risk factors, asthma presentation and severity, and response to various diagnostic tests. Seventy-eight patients with OA diagnosed by positive specific inhalation challenge (SIC) were included. Anthropometric characteristics, atopic status, occupation, latency periods, asthma severity according to the Global Initiative for Asthma (GINA) control classification, lung function tests and SIC results were analysed. OA was induced by an HMW agent in 23 patients (29%) and by an LMW agent in 55 (71%). A logistic regression analysis confirmed that patients with OA caused by LMW agents had a significantly higher risk of severity according to the GINA classification after adjusting for potential confounders (OR = 3.579, 95% CI 1.136-11.280; p = 0.029). During the SIC, most patients with OA caused by HMW agents presented an early reaction (82%), while in patients with OA caused by LMW agents the response was mainly late (73%) (p = 0.0001). Similarly, patients with OA caused by LMW agents experienced a greater degree of bronchial hyperresponsiveness, measured as the difference in the methacholine dose-response ratio (DRR) before and after SIC (1.77, range 0-16), compared with patients with OA caused by HMW agents (0.87, range 0-72), (p = 0.024). OA caused by LMW agents may be more severe than that caused by HMW agents. The severity of the condition may be determined by the different mechanisms of action of these agents.

Ferrimagnetic susceptibility contrast agents.

PubMed

Bach-Gansmo, T

1993-01-01

Contrast agents based on superparamagnetic particles have been in clinical development for more than 5 years, and the complexity of their effects is still not elucidated. The relaxivities are frequently used to give an idea of their efficacy, but these parameters can only be used if they are concentration independent. For large superparamagnetic systems, the evolution of the transverse magnetization is biexponential, after an initial loss of magnetization. Both these characteristics of large superparamagnetic systems should lead to prudence in using the relaxivities as indicators of contrast medium efficacy. Susceptibility induced artefacts have been associated with the use of superparamagnetic contrast agents since the first imaging evaluation took place. The range of concentrations where good contrast effect was achieved without inducing artefacts, as well as blurring and metal artefacts were evaluated. The influence of motion on the induction of artefacts was studied, and compared to the artefacts induced by a paramagnetic agent subject to motion. With a suitable concentration of a negative contrast agent, a signal void could be achieved in the region prone to motion, and no artefacts were induced. If the concentration was too high, a displacement of the region close to the contrast agent was observed. The artefacts occurred in a volume surrounding the contrast agent, i.e., also outside the imaging plane. In comparison a positive, paramagnetic contrast agent induced heavy artefacts in the phase encoding direction, appearing as both high intensity regions and black holes, in a mosaic pattern. Clinical trials of the oral contrast agent OMP for abdominal MR imaging showed this agent to be safe and efficacious. OMP increased the diagnostic efficacy of abdominal MR imaging in 2 of 3 cases examined, with a significant decrease in motion artefacts. Susceptibility contrast agents may also be of use in the evaluation of small lesions in the liver. Particulate material

Online Deception Detection Using BDI Agents

ERIC Educational Resources Information Center

Merritts, Richard A.

2013-01-01

This research has two facets within separate research areas. The research area of Belief, Desire and Intention (BDI) agent capability development was extended. Deception detection research has been advanced with the development of automation using BDI agents. BDI agents performed tasks automatically and autonomously. This study used these…

"Design characteristics of the CORRONA CERTAIN study: a comparative effectiveness study of biologic agents for rheumatoid arthritis patients".

PubMed

Pappas, Dimitrios A; Kremer, Joel M; Reed, George; Greenberg, Jeffrey D; Curtis, Jeffrey R

2014-04-01

Comparative effectiveness research has recently attracted considerable attention. The Comparative Effectiveness Registry to study Therapies for Arthritis and Inflammatory Conditions (CERTAIN) is an ongoing prospective cohort study of adult patients with Rheumatoid Arthritis (RA). CERTAIN uses the existing Consortium of Rheumatology Researchers of North America (CORRONA) network of participating private and academic sites in order to recruit patients fulfilling the 1987 ACR criteria that have at least moderate disease activity. Patients starting or switching biologic agents either anti-TNF therapy or a non anti-TNF biologic are eligible for enrollment, depending on the treatment selected by their physician. Enrollment is expected to be completed by March of 2014, and 2711 patients will participate in the study. As of October 7th 2013, 2234 patients have been enrolled. Patient visits and laboratory blood work are mandated every three months for one year. Safety data is collected through one year and beyond. The primary comparative effectiveness endpoint is attainment of low RA disease activity at one year among patients who have been exposed to at least one prior TNF-α inhibitor agent prior to enrollment. Multiple secondary effectiveness and safety endpoints will be addressed by investigating the entire population enrolled (naïve and biologic experienced). The unique design features of CERTAIN will inform comparative effectiveness and safety questions for choosing biologic agents for the management of RA.

Designing Agent Utilities for Coordinated, Scalable and Robust Multi-Agent Systems

NASA Technical Reports Server (NTRS)

Tumer, Kagan

2005-01-01

Coordinating the behavior of a large number of agents to achieve a system level goal poses unique design challenges. In particular, problems of scaling (number of agents in the thousands to tens of thousands), observability (agents have limited sensing capabilities), and robustness (the agents are unreliable) make it impossible to simply apply methods developed for small multi-agent systems composed of reliable agents. To address these problems, we present an approach based on deriving agent goals that are aligned with the overall system goal, and can be computed using information readily available to the agents. Then, each agent uses a simple reinforcement learning algorithm to pursue its own goals. Because of the way in which those goals are derived, there is no need to use difficult to scale external mechanisms to force collaboration or coordination among the agents, or to ensure that agents actively attempt to appropriate the tasks of agents that suffered failures. To present these results in a concrete setting, we focus on the problem of finding the sub-set of a set of imperfect devices that results in the best aggregate device. This is a large distributed agent coordination problem where each agent (e.g., device) needs to determine whether to be part of the aggregate device. Our results show that the approach proposed in this work provides improvements of over an order of magnitude over both traditional search methods and traditional multi-agent methods. Furthermore, the results show that even in extreme cases of agent failures (i.e., half the agents failed midway through the simulation) the system's performance degrades gracefully and still outperforms a failure-free and centralized search algorithm. The results also show that the gains increase as the size of the system (e.g., number of agents) increases. This latter result is particularly encouraging and suggests that this method is ideally suited for domains where the number of agents is currently in the

Analysis of Nerve Agent Metabolites from Hair for Long-Term Verification of Nerve Agent Exposure

DTIC Science & Technology

2016-05-09

Analysis of Nerve Agent Metabolites from Hair for Long-Term Verification of Nerve Agent Exposure Amanda S. Appel,† John H. McDonough,‡ Joseph D...feasible. In this study, hair was evaluated as a long-term repository of nerve agent hydrolysis products. Pinacolyl methylphosphonic acid (PMPA...hydrolysis product of soman) and isopropyl methylphosphonic acid (IMPA; hydrolysis product of sarin) were extracted from hair samples with N,N

Detection of human pathogenic Ehrlichia muris-like agent in Peromyscus leucopus.

PubMed

Castillo, Caroline G; Eremeeva, Marina E; Paskewitz, Susan M; Sloan, Lynne M; Lee, Xia; Irwin, William E; Tonsberg, Stefan; Pritt, Bobbi S

2015-03-01

An Ehrlichia muris-like (EML) bacterium was recently detected in humans and Ixodes scapularis ticks in Minnesota and Wisconsin. The reservoir for this agent is unknown. To investigate the occurrence of the EML agent, groEL PCR testing and sequencing was performed on blood from small mammals and white-tailed deer that were collected in areas where human and tick infections were previously demonstrated. DNA of the EML agent was detected in two Peromyscus leucopus of 146 small mammals (1.4%); while 181 O. virginianus tested negative. This report provides the first evidence that DNA from the EML agent is found in P. leucopus, the same animal that is a reservoir for Anaplasma phagocytophilum in this region. The role of white-tailed deer remains inconclusive. Further sampling is warranted to understand the spatial and temporal distribution, transmission and maintenance of this pathogen. Copyright © 2014 Elsevier GmbH. All rights reserved.

Instructable autonomous agents. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Huffman, Scott Bradley

1994-01-01

In contrast to current intelligent systems, which must be laboriously programmed for each task they are meant to perform, instructable agents can be taught new tasks and associated knowledge. This thesis presents a general theory of learning from tutorial instruction and its use to produce an instructable agent. Tutorial instruction is a particularly powerful form of instruction, because it allows the instructor to communicate whatever kind of knowledge a student needs at whatever point it is needed. To exploit this broad flexibility, however, a tutorable agent must support a full range of interaction with its instructor to learn a full range of knowledge. Thus, unlike most machine learning tasks, which target deep learning of a single kind of knowledge from a single kind of input, tutorability requires a breadth of learning from a broad range of instructional interactions. The theory of learning from tutorial instruction presented here has two parts. First, a computational model of an intelligent agent, the problem space computational model, indicates the types of knowledge that determine an agent's performance, and thus, that should be acquirable via instruction. Second, a learning technique, called situated explanation specifies how the agent learns general knowledge from instruction. The theory is embodied by an implemented agent, Instructo-Soar, built within the Soar architecture. Instructo-Soar is able to learn hierarchies of completely new tasks, to extend task knowledge to apply in new situations, and in fact to acquire every type of knowledge it uses during task performance - control knowledge, knowledge of operators' effects, state inferences, etc. - from interactive natural language instructions. This variety of learning occurs by applying the situated explanation technique to a variety of instructional interactions involving a variety of types of instructions (commands, statements, conditionals, etc.). By taking seriously the requirements of flexible

Antimicrobial activity of topical agents against Propionibacterium acnes: an in vitro study of clinical isolates from a hospital in Shanghai, China.

PubMed

Ma, Ying; Zhang, Nanxue; Wu, Shi; Huang, Haihui; Cao, Yanpei

2016-12-01

This study aimed to compare the antimicrobial activities of topical agents against Propionibacterium acnes isolated from patients admitted to a hospital in Shanghai, China. The minimal inhibitory concentrations of the cultured P. acnes were determined in accordance with the Clinical and Laboratory Standards Institute. Susceptibilities to clindamycin and erythromycin were compared in terms of gender, age, disease duration, previous treatment, and disease severity. A total of 69 P. acnes strains were isolated from 98 patients (70.41%). The susceptibility to triple antibiotic ointment (neomycin/bacitracin/polymyxin B) and bacitracin was 100%. The susceptibility to fusidic acid was 92.7%. The resistance rates to neomycin sulfate, erythromycin, and clindamycin were 11.7%, 49.3%, and 33.4%, respectively. The high resistance rate to clindamycin and erythromycin was significantly affected by gender, previous treatment, and disease severity rather than by age and disease duration. Topical antibiotics should not be used separately for long-term therapy to avoid multiresistance. The use of topical antibiotics should be determined by clinicians on the basis of clinical conditions.

Summary of Previous Chamber or Controlled Anthrax Studies and Recommendations for Possible Additional Studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Piepel, Gregory F.; Amidan, Brett G.; Morrow, Jayne B.

2010-12-29

This report and an associated Excel file(a) summarizes the investigations and results of previous chamber and controlled studies(b) to characterize the performance of methods for collecting, storing and/or transporting, extracting, and analyzing samples from surfaces contaminated by Bacillus anthracis (BA) or related simulants. This report and the Excel are the joint work of the Pacific Northwest National Laboratory (PNNL) and the National Institute of Standards and Technology (NIST) for the Department of Homeland Security, Science and Technology Directorate. The report was originally released as PNNL-SA-69338, Rev. 0 in November 2009 with limited distribution, but was subsequently cleared for release withmore » unlimited distribution in this Rev. 1. Only minor changes were made to Rev. 0 to yield Rev. 1. A more substantial update (including summarizing data from other studies and more condensed summary tables of data) is underway« less

Toxicity and efficiency study of plant extracts-based bleaching agents.

PubMed

Baldea, Ioana; Olteanu, Diana Elena; Filip, Adriana Gabriela; Cenariu, Mihai; Dudea, Diana; Tofan, Alina; Alb, Camelia; Moldovan, Marioara

2017-05-01

Tooth bleaching is one of the most required dental esthetic treatments. However, it can generate side effects like oral irritation, enamel alteration, tooth sensitivity, especially caused by hydrogen peroxide, the main bleaching component of the commercial products. Therefore, development of new tooth bleaching agents, based on natural products, with comparable esthetic results and lower side effects is needed. The aim of this study was to evaluate the biological effects and bleaching efficacy of four experimental bleaching agents, derived from fruit juices, against the commercially available Opalescence (Ultradent, USA). Organic acid composition of the gels was characterized by HPLC. Bleaching efficiency was tested by spectrophotometry on composite restorative materials. Biological testing was done in vitro, on human fibroblasts. Cells were exposed to dilutions of the bleaching gel-conditioned medium. Viability was measured by MTS, apoptosis by FACS-AnnexinV FITC/Propidium iodide, NF-kB activation by western blot, malondyaldehide, and superoxide dismutase activity by spectrophotometry. All gels exhibited physical stability and dental bleaching capabilities. Experimental gels induced significantly better viability and apoptosis rates, lower lipid peroxidation, and increased antioxidant defense, compared to Opalescence. The studied experimental gel formulations exhibited a good safety profile in vitro, as well as bleaching efficiency on restorative composite materials. These data open new possibilities for the use of new natural products in dental bleaching treatments that can insure significant esthetic results and lower side effects.

Autonomy in robots and other agents.

PubMed

Smithers, T

1997-06-01

The word "autonomous" has become widely used in artificial intelligence, robotics, and, more recently, artificial life and is typically used to qualify types of systems, agents, or robots: we see terms like "autonomous systems," "autonomous agents," and "autonomous robots." Its use in these fields is, however, both weak, with no distinctions being made that are not better and more precisely made with other existing terms, and varied, with no single underlying concept being involved. This ill-disciplined usage contrasts strongly with the use of the same term in other fields such as biology, philosophy, ethics, law, and human rights, for example. In all these quite different areas the concept of autonomy is essentially the same, though the language used and the aspects and issues of concern, of course, differ. In all these cases the underlying notion is one of self-law making and the closely related concept of self-identity. In this paper I argue that the loose and varied use of the term autonomous in artificial intelligence, robotics, and artificial life has effectively robbed these fields of an important concept. A concept essentially the same as we find it in biology, philosophy, ethics, and law, and one that is needed to distinguish a particular kind of agent or robot from those developed and built so far. I suggest that robots and other agents will have to be autonomous, i.e., self-law making, not just self-regulating, if they are to be able effectively to deal with the kinds of environments in which we live and work: environments which have significant large scale spatial and temporal invariant structure, but which also have large amounts of local spatial and temporal dynamic variation and unpredictability, and which lead to the frequent occurrence of previously unexperienced situations for the agents that interact with them.

Integrated Agent-Based and Production Cost Modeling Framework for Renewable Energy Studies: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gallo, Giulia

The agent-based framework for renewable energy studies (ARES) is an integrated approach that adds an agent-based model of industry actors to PLEXOS and combines the strengths of the two to overcome their individual shortcomings. It can examine existing and novel wholesale electricity markets under high penetrations of renewables. ARES is demonstrated by studying how increasing levels of wind will impact the operations and the exercise of market power of generation companies that exploit an economic withholding strategy. The analysis is carried out on a test system that represents the Electric Reliability Council of Texas energy-only market in the year 2020.more » The results more realistically reproduce the operations of an energy market under different and increasing penetrations of wind, and ARES can be extended to address pressing issues in current and future wholesale electricity markets.« less

Resolving the Framework Position of Organic Structure-Directing Agents in Hierarchical Zeolites via Polarized Stimulated Raman Scattering.

PubMed

Fleury, Guillaume; Steele, Julian A; Gerber, Iann C; Jolibois, F; Puech, P; Muraoka, Koki; Keoh, Sye Hoe; Chaikittisilp, Watcharop; Okubo, Tatsuya; Roeffaers, Maarten B J

2018-04-05

The direct synthesis of hierarchically intergrown silicalite-1 can be achieved using a specific diquaternary ammonium agent. However, the location of these molecules in the zeolite framework, which is critical to understand the formation of the material, remains unclear. Where traditional characterization tools have previously failed, herein we use polarized stimulated Raman scattering (SRS) microscopy to resolve molecular organization inside few-micron-sized crystals. Through a combination of experiment and first-principles calculations, our investigation reveals the preferential location of the templating agent inside the linear pores of the MFI framework. Besides illustrating the attractiveness of SRS microscopy in the field of material science to study and spatially resolve local molecular distribution as well as orientation, these results can be exploited in the design of new templating agents for the preparation of hierarchical zeolites.

Dermatomyositis-like syndrome induced by nonsteroidal anti-inflammatory agents.

PubMed

Grob, J J; Collet, A M; Bonerandi, J J

1989-01-01

A dermatomyositis-like syndrome developed in a patient treated with a nonsteroidal anti-inflammatory agent (NSAI), niflumic acid, and regressed after the cessation of treatment. Previously an eruption had occurred under treatment with another NSAI, diclofenac. Our report shows that NSAI can induce not only lupus-like syndromes but also other connective tissue disorders.

Cost-effectiveness of oral antiplatelet agents--current and future perspectives.

PubMed

Arnold, Suzanne V; Cohen, David J; Magnuson, Elizabeth A

2011-08-09

Cardiovascular disease is both highly prevalent and exceedingly costly to treat. Several novel antiplatelet agents have been found to be effective in reducing the morbidity and mortality associated with cardiovascular disease. Understanding both the economic and the clinical implications of these novel therapies is particularly important. In this article, the results of published evaluations of the cost-effectiveness of oral antiplatelet strategies for use across a range of clinical conditions and treatment settings are reviewed. The results of these studies support the use of aspirin for primary prevention in high-risk patients and for secondary prevention in all patients with previous cardiovascular events. Although the optimal duration of dual antiplatelet therapy after an event remains uncertain, favorable cost-effectiveness estimates have been demonstrated for aspirin plus clopidogrel versus aspirin alone after a myocardial infarction or percutaneous coronary intervention. Moreover, prasugrel has been shown to be more cost-effective than clopidogrel for patients with an acute coronary syndrome and planned percutaneous coronary intervention. As novel antiplatelet agents emerge and existing agents are tested in different patient populations, the evaluation of the relative economic efficiency of these oral antiplatelet treatment strategies will continue to be instrumental to optimally inform clinical and health-policy decision-making.

22 CFR 51.22 - Passport agents and passport acceptance agents.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Passport agents and passport acceptance agents. 51.22 Section 51.22 Foreign Relations DEPARTMENT OF STATE NATIONALITY AND PASSPORTS PASSPORTS Application § 51.22 Passport agents and passport acceptance agents. (a) U.S. citizen employees of the...

22 CFR 51.22 - Passport agents and passport acceptance agents.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Passport agents and passport acceptance agents. 51.22 Section 51.22 Foreign Relations DEPARTMENT OF STATE NATIONALITY AND PASSPORTS PASSPORTS Application § 51.22 Passport agents and passport acceptance agents. (a) U.S. citizen employees of the...

22 CFR 51.22 - Passport agents and passport acceptance agents.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Passport agents and passport acceptance agents. 51.22 Section 51.22 Foreign Relations DEPARTMENT OF STATE NATIONALITY AND PASSPORTS PASSPORTS Application § 51.22 Passport agents and passport acceptance agents. (a) U.S. citizen employees of the...

22 CFR 51.22 - Passport agents and passport acceptance agents.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Passport agents and passport acceptance agents. 51.22 Section 51.22 Foreign Relations DEPARTMENT OF STATE NATIONALITY AND PASSPORTS PASSPORTS Application § 51.22 Passport agents and passport acceptance agents. (a) U.S. citizen employees of the...

22 CFR 51.22 - Passport agents and passport acceptance agents.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Passport agents and passport acceptance agents. 51.22 Section 51.22 Foreign Relations DEPARTMENT OF STATE NATIONALITY AND PASSPORTS PASSPORTS Application § 51.22 Passport agents and passport acceptance agents. (a) U.S. citizen employees of the...

Analysis of genetic diversity of Fusarium tupiense, the main causal agent of mango malformation disease in southern Spain

USDA-ARS?s Scientific Manuscript database

Mango malformation disease (MMD) has become an important global disease affecting this crop. The aim of this study was to identify the main causal agents of MMD in the Axarquía region of southern Spain and determine their genetic diversity. Fusarium mangiferae was previously described in the Axarquí...

Sofosbuvir, Velpatasvir, and Voxilaprevir for Previously Treated HCV Infection.

PubMed

Bourlière, Marc; Gordon, Stuart C; Flamm, Steven L; Cooper, Curtis L; Ramji, Alnoor; Tong, Myron; Ravendhran, Natarajan; Vierling, John M; Tran, Tram T; Pianko, Stephen; Bansal, Meena B; de Lédinghen, Victor; Hyland, Robert H; Stamm, Luisa M; Dvory-Sobol, Hadas; Svarovskaia, Evguenia; Zhang, Jie; Huang, K C; Subramanian, G Mani; Brainard, Diana M; McHutchison, John G; Verna, Elizabeth C; Buggisch, Peter; Landis, Charles S; Younes, Ziad H; Curry, Michael P; Strasser, Simone I; Schiff, Eugene R; Reddy, K Rajender; Manns, Michael P; Kowdley, Kris V; Zeuzem, Stefan

2017-06-01

Patients who are chronically infected with hepatitis C virus (HCV) and who do not have a sustained virologic response after treatment with regimens containing direct-acting antiviral agents (DAAs) have limited retreatment options. We conducted two phase 3 trials involving patients who had been previously treated with a DAA-containing regimen. In POLARIS-1, patients with HCV genotype 1 infection who had previously received a regimen containing an NS5A inhibitor were randomly assigned in a 1:1 ratio to receive either the nucleotide polymerase inhibitor sofosbuvir, the NS5A inhibitor velpatasvir, and the protease inhibitor voxilaprevir (150 patients) or matching placebo (150 patients) once daily for 12 weeks. Patients who were infected with HCV of other genotypes (114 patients) were enrolled in the sofosbuvir-velpatasvir-voxilaprevir group. In POLARIS-4, patients with HCV genotype 1, 2, or 3 infection who had previously received a DAA regimen but not an NS5A inhibitor were randomly assigned in a 1:1 ratio to receive sofosbuvir-velpatasvir-voxilaprevir (163 patients) or sofosbuvir-velpatasvir (151 patients) for 12 weeks. An additional 19 patients with HCV genotype 4 infection were enrolled in the sofosbuvir-velpatasvir-voxilaprevir group. In the three active-treatment groups, 46% of the patients had compensated cirrhosis. In POLARIS-1, the rate of sustained virologic response was 96% with sofosbuvir-velpatasvir-voxilaprevir, as compared with 0% with placebo. In POLARIS-4, the rate of response was 98% with sofosbuvir-velpatasvir-voxilaprevir and 90% with sofosbuvir-velpatasvir. The most common adverse events were headache, fatigue, diarrhea, and nausea. In the active-treatment groups in both trials, the percentage of patients who discontinued treatment owing to adverse events was 1% or lower. Sofosbuvir-velpatasvir-voxilaprevir taken for 12 weeks provided high rates of sustained virologic response among patients across HCV genotypes in whom treatment with a DAA regimen

Overcoming platinum drug resistance with copper-lowering agents.

PubMed

Chen, Helen H W; Kuo, Macus Tien

2013-10-01

Platinum (Pt)-based antitumor agents have been the mainstay of cancer chemotherapy for the last three decades. While multiple mechanisms are responsible for treatment failure, deficiency in drug transport is an important contributor. The human high-affinity copper (Cu) transporter-1 (hCtr1) can also transport Pt-based drugs including cisplatin (cDDP) and carboplatin. Reduced hCtr1 expression frequently occurs in cDDP-resistant cell lines and in cancer in patients who failed chemotherapy with these drugs. We previously demonstrated that Cu chelation induces the expression of transcription factor Sp1 which binds the promoters of Sp1 and hCtr1, thereby, up-regulating their expression, whereas Cu overload shuts down hCtr1 and Sp1 expression by dissociating Sp1 from their promoter promoters. Thus, mammalian Cu homeostasis is transcriptionally regulated within a loop consisting of Sp1, hCtr1, and Cu in a three-way mutually regulated manner. These findings suggest that it is feasible to module cDDP transport capacity through intervention of mammalian Cu homeostasis. Indeed, we found that cDDP resistance can be overcome by Cu-lowering agents through enhanced hCtr1 expression by up-regulation of Sp1 in cultured cells. This discovery provided a mechanistic basis for the ongoing clinical study using Cu chelator to overcome cDDP resistance in ovarian cancer chemotherapy. Preliminary study using copper chelator (trientine) for enhancing the treatment efficacy of carboplatin in 5 ovarian cancer patients showed encouraging results. This short review describes the perspectives of using Cu-lowering agents in overcoming Pt resistance in cancer chemotherapy.

Outcomes after Stroke in Patients with Previous Pressure Ulcer: A Nationwide Matched Retrospective Cohort Study.

PubMed

Lee, Shang-Yi; Chou, Chia-Lun; Hsu, Sanford P C; Shih, Chun-Chuan; Yeh, Chun-Chieh; Hung, Chih-Jen; Chen, Ta-Liang; Liao, Chien-Chang

2016-01-01

Factors associated with poststroke adverse events were not completely understood. The purpose of this study was to investigate whether stroke patients with previous pressure ulcers had more adverse events after stroke. Using the claims data from Taiwan's National Health Insurance Research Database, we conducted a retrospective cohort study matched by propensity score. Three thousand two first-ever stroke patients with previous pressure ulcer and 3002 first-ever stroke patients without pressure ulcer were investigated between 2002 and 2009. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of complications and 30-day mortality after stroke associated with previous pressure ulcer were calculated in the multivariate logistic regressions. Patients with pressure ulcer had significantly higher risk than control for poststroke urinary tract infection (OR: 1.56, 95% CI: 1.38-1.78), pneumonia (OR: 1.35, 95% CI: 1.16-1.58), gastrointestinal bleeding (OR: 1.31, 95% CI: 1.04-1.66), and epilepsy (OR: 1.84, 95% CI: 1.83-1.85). Stroke patients with pressure ulcer had increased 30-day poststroke mortality (OR: 2.01, 95% CI: 1.55-2.61), particularly in those treated with debridement (OR: 2.87, 95% CI: 1.85-4.44) or high quantity of antibiotics (OR: 4.01, 95% CI: 2.10-7.66). Pressure ulcer was associated with poststroke mortality in both genders and patients aged 60 years or older. This study showed increased poststroke complications and mortality in patients with previous pressure ulcer, which suggests the urgent need for monitoring stroke patients for pressure ulcer history. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Dynamical systems approach to the study of a sociophysics agent-based model

NASA Astrophysics Data System (ADS)

Timpanaro, André M.; Prado, Carmen P. C.

2011-03-01

The Sznajd model is a Potts-like model that has been studied in the context of sociophysics [1,2] (where spins are interpreted as opinions). In a recent work [3], we generalized the Sznajd model to include assymetric interactions between the spins (interpreted as biases towards opinions) and used dynamical systems techniques to tackle its mean-field version, given by the flow: ησ = ∑ σ' = 1Mησησ'(ησρσ'→σ-σ'ρσ→σ'). Where hs is the proportion of agents with opinion (spin) σ', M is the number of opinions and σ'→σ' is the probability weight for an agent with opinion σ being convinced by another agent with opinion σ'. We made Monte Carlo simulations of the model in a complex network (using Barabási-Albert networks [4]) and they displayed the same attractors than the mean-field. Using linear stability analysis, we were able to determine the mean-field attractor structure analytically and to show that it has connections with well known graph theory problems (maximal independent sets and positive fluxes in directed graphs). Our dynamical systems approach is quite simple and can be used also in other models, like the voter model.

Petri Nets as Modeling Tool for Emergent Agents

NASA Technical Reports Server (NTRS)

Bergman, Marto

2004-01-01

Emergent agents, those agents whose local interactions can cause unexpected global results, require a method of modeling that is both dynamic and structured Petri Nets, a modeling tool developed for dynamic discrete event system of mainly functional agents, provide this, and have the benefit of being an established tool. We present here the details of the modeling method here and discuss how to implement its use for modeling agent-based systems. Petri Nets have been used extensively in the modeling of functional agents, those agents who have defined purposes and whose actions should result in a know outcome. However, emergent agents, those agents who have a defined structure but whose interaction causes outcomes that are unpredictable, have not yet found a modeling style that suits them. A problem with formally modeling emergent agents that any formal modeling style usually expects to show the results of a problem and the results of problems studied using emergent agents are not apparent from the initial construction. However, the study of emergent agents still requires a method to analyze the agents themselves, and have sensible conversation about the differences and similarities between types of emergent agents. We attempt to correct this problem by applying Petri Nets to the characterization of emergent agents. In doing so, the emergent properties of these agents can be highlighted, and conversation about the nature and compatibility of the differing methods of agent creation can begin.

[Hantavirus as important emerging agents in South America].

PubMed

Ondoño, Andrés F; Levis, Silvana; Rodas, Juan D

2011-01-01

The dawning of the 20th century was marked by the emergence of new infectious disease agents and the appearance of others previously thought controlled. Both phenomena were possibly connected with ecological disturbances that led to the recognition of a dramatic climate change, of which the effects are only now becoming noticeable. Among the variety of agents to be considered, the many new viruses stand out, not only for their numerical proliferation, but also for their genetic versatility. It is this quality that provides them dexterity for evolving new strategies and adaptations to changing environmental conditions. Recently, some of the most ubiquitous and well-publicized viral agents in the American continents have been the rodent-borne viruses, and among these are the hantaviruses, etiological agents of pulmonary syndromes. Approximately 18 hantaviruses (belonging to the family Bunyaviridae), have been discovered in South America during the last 20 years, and although most of them cause persistent infections and subclinical infections in wild rodents (particularly members of the subfamily Sigmodontinae) and humans respectively; some others might also be highly lethal for humans. The goal herein is to review the state of the art regarding general aspects of hantaviruses and the diseases they cause around the world, highlighting the most recent findings in Colombia. Finally, the many unanswered questions will be recognized and highlighted concerning clinical importance and socio-economic impact of these agents on quality of public health in Colombia.

The study of life change unit as stressor agents among Tehran University of Medical Sciences Hospitals' employees.

PubMed

Dargahi, Hossein; Sharifiy Yazdi, Mohammad Kazem

2010-01-01

Life crises as stressor agents can disrupt the best stress management regime. Different life crises have different impacts. A standard scale to rate change and its related stress impact has been developed commonly referred to as LCU (life change unit) rating. This allocates a number of life crisis units or life change units (LCUs) to different event and then evaluates them and takes action accordingly. This idea behind this approach of is to rundown the LCU table, totaling the LCUs for life crisis that have occurred in the previous one year. A cross-sectional, descriptive and analytical study was conducted among 900 Tehran University of Medical Sciences (TUMS) employees by a Holms and Rahe LCU questionnaire at 15 hospitals. The respondents were asked to determine their demographic information, list of stress symptoms which suffered from these diseases in the previous one year and finally, responded to 45 Life Change Unit as stressful life events and the value of each in "stress units" which occurred in the previous one year. The results showed that there is significant correlation between the employees LCU rating by sex, educational degree and size of hospital. Also we found that there are significant correlations between the employees stress symptoms with their LCU rating. Totally, 40% of the employees have less than 150 LCU rating (normal range) and 60% of them have 150-300 or more than 300 LCU rating (abnormal range). In conclusion most of TUMS hospitals' employees who had stress symptoms have more LCU rating. One third of these employees are not in danger of suffering the illness effect, while two third of them are in danger.

An Exploratory Study on How Children Interact with Pedagogic Conversational Agents

ERIC Educational Resources Information Center

Pérez-Marín, Diana; Pascual-Nieto, Ismael

2013-01-01

A pedagogic conversational agent (PCA) can be defined as a computer system that interacts with the student in natural language assuming the role of the instructor, a student or a companion. It can have a personality and can generate different sentences according to the agent or the student mood. Empathy with the students' feelings seems to…

Abstract-Reasoning Software for Coordinating Multiple Agents

NASA Technical Reports Server (NTRS)

Clement, Bradley; Barrett, Anthony; Rabideau, Gregg; Knight, Russell

2003-01-01

A computer program for scheduling the activities of multiple agents that share limited resources has been incorporated into the Automated Scheduling and Planning Environment (ASPEN) software system, aspects of which have been reported in several previous NASA Tech Briefs articles. In the original intended application, the agents would be multiple spacecraft and/or robotic vehicles engaged in scientific exploration of distant planets. The program could also be used on Earth in such diverse settings as production lines and military maneuvers. This program includes a planning/scheduling subprogram of the iterative repair type that reasons about the activities of multiple agents at abstract levels in order to greatly improve the scheduling of their use of shared resources. The program summarizes the information about the constraints on, and resource requirements of, abstract activities on the basis of the constraints and requirements that pertain to their potential refinements (decomposition into less-abstract and ultimately to primitive activities). The advantage of reasoning about summary information is that time needed to find consistent schedules is exponentially smaller than the time that would be needed for reasoning about the same tasks at the primitive level.

A numerical study of combined use of two biocontrol agents with different biocontrol mechanisms in controlling foliar pathogens.

PubMed

Xu, X-M; Jeffries, P; Pautasso, M; Jeger, M J

2011-09-01

Effective use of biocontrol agents is an important component of sustainable agriculture. A previous numerical study of a generic model showed that biocontrol efficacy was greatest for a single biocontrol agent (BCA) combining competition with mycoparasitism or antibiosis. This study uses the same mathematical model to investigate whether the biocontrol efficacy of combined use of two BCAs with different biocontrol mechanisms is greater than that of a single BCA with either or both of the two mechanisms, assuming that two BCAs occupy the same host tissue as the pathogen. Within the parameter values considered, a BCA with two biocontrol mechanisms always outperformed the combined use of two BCAs with a single but different biocontrol mechanism. Similarly, combined use of two BCAs with a single but different biocontrol mechanism is shown to be far less effective than that of a single BCA with both mechanisms. Disease suppression from combined use of two BCAs was very similar to that achieved by the more efficacious one. As expected, a higher BCA introduction rate led to increased disease suppression. Incorporation of interactions between two BCAs did not greatly affect the disease dynamics except when a mycoparasitic and, to a lesser extent, an antibiotic-producing BCA was involved. Increasing the competitiveness of a mycoparasitic BCA over a BCA whose biocontrol mechanism is either competition or antibiosis may lead to improved biocontrol initially and reduced fluctuations in disease dynamics. The present study suggests that, under the model assumptions, combined use of two BCAs with different biocontrol mechanisms in most cases only results in control efficacies similar to using the more efficacious one alone. These predictions are consistent with published experimental results, suggesting that combined use of BCAs should not be recommended without clear understanding of their main biocontrol mechanisms and relative competitiveness, and experimental evaluation.

Efficient priority queueing routing strategy on networks of mobile agents

NASA Astrophysics Data System (ADS)

Wu, Gan-Hua; Yang, Hui-Jie; Pan, Jia-Hui

2018-03-01

As a consequence of their practical implications for communications networks, traffic dynamics on complex networks have recently captivated researchers. Previous routing strategies for improving transport efficiency have paid little attention to the orders in which the packets should be forwarded, just simply used first-in-first-out queue discipline. Here, we apply a priority queuing discipline and propose a shortest-distance-first routing strategy on networks of mobile agents. Numerical experiments reveal that the proposed scheme remarkably improves both the network throughput and the packet arrival rate and reduces both the average traveling time and the rate of waiting time to traveling time. Moreover, we find that the network capacity increases with an increase in both the communication radius and the number of agents. Our work may be helpful for the design of routing strategies on networks of mobile agents.

Induction of abnormal respiratory sounds by capsaicin in rats previously infected with Bordetella pertussis.

PubMed

Parton, R; Hall, E; Wardlaw, A C

1998-02-01

Sprague Dawley rats, previously infected with Phase-I Bordetella pertussis, developed more severe abnormal respiratory sounds than normal animals, but not coughing, when exposed to aerosolized capsaicin, one of several cough-inducing agents tested. Stethoscope examination suggested that greater production of pulmonary mucus might be occurring after capsaicin challenge of the infected animals, compared to the uninfected controls. Rats of three other strains gave characteristically different responses from the Sprague Dawleys. The administration of capsaicin to B. pertussis-infected rats may provide useful insights into the pathophysiology of excess mucus secretion in human pertussis.

Cognitive, cultural, and linguistic sources of a handshape distinction expressing agentivity.

PubMed

Brentari, Diane; Di Renzo, Alessio; Keane, Jonathan; Volterra, Virginia

2015-01-01

In this paper the cognitive, cultural, and linguistic bases for a pattern of conventionalization of two types of iconic handshapes are described. Work on sign languages has shown that handling handshapes (H-HSs: those that represent how objects are handled or manipulated) and object handshapes (O-HSs: those that represent the class, size, or shape of objects) express an agentive/non-agentive semantic distinction in many sign languages. H-HSs are used in agentive event descriptions and O-HSs are used in non-agentive event descriptions. In this work, American Sign Language (ASL) and Italian Sign Language (LIS) productions are compared (adults and children) as well as the corresponding groups of gesturers in each country using "silent gesture." While the gesture groups, in general, did not employ an H-HS/O-HS distinction, all participants (signers and gesturers) used iconic handshapes (H-HSs and O-HSs together) more often in agentive than in no-agent event descriptions; moreover, none of the subjects produced an opposite pattern than the expected one (i.e., H-HSs associated with no-agent descriptions and O-HSs associated with agentive ones). These effects are argued to be grounded in cognition. In addition, some individual gesturers were observed to produce the H-HS/O-HS opposition for agentive and non-agentive event descriptions-that is, more Italian than American adult gesturers. This effect is argued to be grounded in culture. Finally, the agentive/non-agentive handshape opposition is confirmed for signers of ASL and LIS, but previously unreported cross-linguistic differences were also found across both adult and child sign groups. It is, therefore, concluded that cognitive, cultural, and linguistic factors contribute to the conventionalization of this distinction of handshape type. Copyright © 2014 Cognitive Science Society, Inc.

Synthesis and SAR studies of very potent imidazopyridine antiprotozoal agents.

PubMed

Biftu, Tesfaye; Feng, Dennis; Fisher, Michael; Liang, Gui-Bai; Qian, Xiaoxia; Scribner, Andrew; Dennis, Richard; Lee, Shuliang; Liberator, Paul A; Brown, Chris; Gurnett, Anne; Leavitt, Penny S; Thompson, Donald; Mathew, John; Misura, Andrew; Samaras, Samantha; Tamas, Tamas; Sina, Joseph F; McNulty, Kathleen A; McKnight, Crystal G; Schmatz, Dennis M; Wyvratt, Matthew

2006-05-01

Compounds 10a (IC50 110 pM) and 21 (IC50 40 pM) are the most potent inhibitors of Eimeria tenella cGMP-dependent protein kinase activity reported to date and are efficacious in the in vivo antiparasitic assay when administered to chickens at 12.5 and 6.25 ppm levels in the feed. However, both compounds are positive in the Ames microbial mutagenesis assay which precludes them from further development as antiprotozoal agents in the absence of negative lifetime rodent carcinogenicity studies.

Agent-based modeling: case study in cleavage furrow models

PubMed Central

Mogilner, Alex; Manhart, Angelika

2016-01-01

The number of studies in cell biology in which quantitative models accompany experiments has been growing steadily. Roughly, mathematical and computational techniques of these models can be classified as “differential equation based” (DE) or “agent based” (AB). Recently AB models have started to outnumber DE models, but understanding of AB philosophy and methodology is much less widespread than familiarity with DE techniques. Here we use the history of modeling a fundamental biological problem—positioning of the cleavage furrow in dividing cells—to explain how and why DE and AB models are used. We discuss differences, advantages, and shortcomings of these two approaches. PMID:27811328

TACtic- A Multi Behavioral Agent for Trading Agent Competition

NASA Astrophysics Data System (ADS)

Khosravi, Hassan; Shiri, Mohammad E.; Khosravi, Hamid; Iranmanesh, Ehsan; Davoodi, Alireza

Software agents are increasingly being used to represent humans in online auctions. Such agents have the advantages of being able to systematically monitor a wide variety of auctions and then make rapid decisions about what bids to place in what auctions. They can do this continuously and repetitively without losing concentration. To provide a means of evaluating and comparing (benchmarking) research methods in this area the trading agent competition (TAC) was established. This paper describes the design, of TACtic. Our agent uses multi behavioral techniques at the heart of its decision making to make bidding decisions in the face of uncertainty, to make predictions about the likely outcomes of auctions, and to alter the agent's bidding strategy in response to the prevailing market conditions.

The Effects of Peer-Like and Expert-Like Pedagogical Agents on Learners' Agent Perceptions, Task-Related Attitudes, and Learning Achievement

ERIC Educational Resources Information Center

Liew, Tze Wei; Tan, Su-Mae; Jayothisa, Chandrika

2013-01-01

The present study examined the impact of peer-like and expert-like agent stereotypes, as operationalized by agent's image and voice, on learners' agent perceptions, task-related attitudes, and learning achievement. 56 university freshmen (23 males and 33 females) interacted with either the peer-like agent (female college student) or the…

Multifunctional ultra-high vacuum apparatus for studies of the interactions of chemical warfare agents on complex surfaces

NASA Astrophysics Data System (ADS)

Wilmsmeyer, Amanda R.; Gordon, Wesley O.; Davis, Erin Durke; Mantooth, Brent A.; Lalain, Teri A.; Morris, John R.

2014-01-01

A fundamental understanding of the surface chemistry of chemical warfare agents is needed to fully predict the interaction of these toxic molecules with militarily relevant materials, catalysts, and environmental surfaces. For example, rules for predicting the surface chemistry of agents can be applied to the creation of next generation decontaminants, reactive coatings, and protective materials for the warfighter. Here, we describe a multifunctional ultra-high vacuum instrument for conducting comprehensive studies of the adsorption, desorption, and surface chemistry of chemical warfare agents on model and militarily relevant surfaces. The system applies reflection-absorption infrared spectroscopy, x-ray photoelectron spectroscopy, and mass spectrometry to study adsorption and surface reactions of chemical warfare agents. Several novel components have been developed to address the unique safety and sample exposure challenges that accompany the research of these toxic, often very low vapor pressure, compounds. While results of vacuum-based surface science techniques may not necessarily translate directly to environmental processes, learning about the fundamental chemistry will begin to inform scientists about the critical aspects that impact real-world applications.

Multifunctional ultra-high vacuum apparatus for studies of the interactions of chemical warfare agents on complex surfaces.

PubMed

Wilmsmeyer, Amanda R; Gordon, Wesley O; Davis, Erin Durke; Mantooth, Brent A; Lalain, Teri A; Morris, John R

2014-01-01

A fundamental understanding of the surface chemistry of chemical warfare agents is needed to fully predict the interaction of these toxic molecules with militarily relevant materials, catalysts, and environmental surfaces. For example, rules for predicting the surface chemistry of agents can be applied to the creation of next generation decontaminants, reactive coatings, and protective materials for the warfighter. Here, we describe a multifunctional ultra-high vacuum instrument for conducting comprehensive studies of the adsorption, desorption, and surface chemistry of chemical warfare agents on model and militarily relevant surfaces. The system applies reflection-absorption infrared spectroscopy, x-ray photoelectron spectroscopy, and mass spectrometry to study adsorption and surface reactions of chemical warfare agents. Several novel components have been developed to address the unique safety and sample exposure challenges that accompany the research of these toxic, often very low vapor pressure, compounds. While results of vacuum-based surface science techniques may not necessarily translate directly to environmental processes, learning about the fundamental chemistry will begin to inform scientists about the critical aspects that impact real-world applications.

Multifunctional ultra-high vacuum apparatus for studies of the interactions of chemical warfare agents on complex surfaces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilmsmeyer, Amanda R.; Morris, John R.; Gordon, Wesley O.

2014-01-15

A fundamental understanding of the surface chemistry of chemical warfare agents is needed to fully predict the interaction of these toxic molecules with militarily relevant materials, catalysts, and environmental surfaces. For example, rules for predicting the surface chemistry of agents can be applied to the creation of next generation decontaminants, reactive coatings, and protective materials for the warfighter. Here, we describe a multifunctional ultra-high vacuum instrument for conducting comprehensive studies of the adsorption, desorption, and surface chemistry of chemical warfare agents on model and militarily relevant surfaces. The system applies reflection-absorption infrared spectroscopy, x-ray photoelectron spectroscopy, and mass spectrometry tomore » study adsorption and surface reactions of chemical warfare agents. Several novel components have been developed to address the unique safety and sample exposure challenges that accompany the research of these toxic, often very low vapor pressure, compounds. While results of vacuum-based surface science techniques may not necessarily translate directly to environmental processes, learning about the fundamental chemistry will begin to inform scientists about the critical aspects that impact real-world applications.« less

A Questionnaire Study on the Attitudes and Previous Experience of Croatian Family Physicians toward their Preparedness for Disaster Management.

PubMed

Pekez-Pavliško, Tanja; Račić, Maja; Jurišić, Dinka

2018-04-01

To explore family physicians' attitudes, previous experience and self-assessed preparedness to respond or to assist in mass casualty incidents in Croatia. The cross-sectional survey was carried out during January 2017. Study participants were recruited through a Facebook group that brings together family physicians from Croatia. They were asked to complete the questionnaire, which was distributed via google.docs. Knowledge and attitudes toward disaster preparedness were evaluated by 18 questions. Analysis of variance, Student t test and Kruskal-Wallis test t were used for statistical analysis. Risk awareness of disasters was high among respondents (M = 4.89, SD=0.450). Only 16.4 of respondents have participated in the management of disaster at the scene. The majority (73.8%) of physicians have not been participating in any educational activity dealing with disaster over the past two years. Family physicians believed they are not well prepared to participate in national (M = 3.02, SD=0.856) and local community emergency response system for disaster (M = 3.16, SD=1.119). Male physicians scored higher preparedness to participate in national emergency response system for disaster ( p =0.012), to carry out accepted triage principles used in the disaster situation ( p =0.003) and recognize differences in health assessments indicating potential exposure to specific agents ( p =0,001) compared to their female colleagues. Croatian primary healthcare system attracts many young physicians, who can be an important part of disaster and emergency management. However, the lack of experience despite a high motivation indicates a need for inclusion of disaster medicine training during undergraduate studies and annual educational activities.

Gryphon: A Hybrid Agent-Based Modeling and Simulation Platform for Infectious Diseases

NASA Astrophysics Data System (ADS)

Yu, Bin; Wang, Jijun; McGowan, Michael; Vaidyanathan, Ganesh; Younger, Kristofer

In this paper we present Gryphon, a hybrid agent-based stochastic modeling and simulation platform developed for characterizing the geographic spread of infectious diseases and the effects of interventions. We study both local and non-local transmission dynamics of stochastic simulations based on the published parameters and data for SARS. The results suggest that the expected numbers of infections and the timeline of control strategies predicted by our stochastic model are in reasonably good agreement with previous studies. These preliminary results indicate that Gryphon is able to characterize other future infectious diseases and identify endangered regions in advance.

Brief introductory guide to agent-based modeling and an illustration from urban health research.

PubMed

Auchincloss, Amy H; Garcia, Leandro Martin Totaro

2015-11-01

There is growing interest among urban health researchers in addressing complex problems using conceptual and computation models from the field of complex systems. Agent-based modeling (ABM) is one computational modeling tool that has received a lot of interest. However, many researchers remain unfamiliar with developing and carrying out an ABM, hindering the understanding and application of it. This paper first presents a brief introductory guide to carrying out a simple agent-based model. Then, the method is illustrated by discussing a previously developed agent-based model, which explored inequalities in diet in the context of urban residential segregation.

Brief introductory guide to agent-based modeling and an illustration from urban health research

PubMed Central

Auchincloss, Amy H.; Garcia, Leandro Martin Totaro

2017-01-01

There is growing interest among urban health researchers in addressing complex problems using conceptual and computation models from the field of complex systems. Agent-based modeling (ABM) is one computational modeling tool that has received a lot of interest. However, many researchers remain unfamiliar with developing and carrying out an ABM, hindering the understanding and application of it. This paper first presents a brief introductory guide to carrying out a simple agent-based model. Then, the method is illustrated by discussing a previously developed agent-based model, which explored inequalities in diet in the context of urban residential segregation. PMID:26648364

Synthesis and evaluation of novel caged DNA alkylating agents bearing 3,4-epoxypiperidine structure.

PubMed

Kawada, Yuji; Kodama, Tetsuya; Miyashita, Kazuyuki; Imanishi, Takeshi; Obika, Satoshi

2012-07-14

Previously, we reported that the 3,4-epoxypiperidine structure, whose design was based on the active site of DNA alkylating antitumor antibiotics, azinomycins A and B, possesses prominent DNA cleavage activity. In this report, novel caged DNA alkylating agents, which were designed to be activated by UV irradiation, were synthesized by the introduction of four photo-labile protecting groups to a 3,4-epoxypiperidine derivative. The DNA cleavage activity and cytotoxicity of the caged DNA alkylating agents were examined under UV irradiation. Four caged DNA alkylating agents showed various degrees of bioactivity depending on the photosensitivity of the protecting groups.

Studies of Opinion Stability for Small Dynamic Networks with Opportunistic Agents

NASA Astrophysics Data System (ADS)

Sobkowicz, Pawel

There are numerous examples of societies with extremely stable mix of contrasting opinions. We argue that this stability is a result of an interplay between society network topology adjustment and opinion changing processes. To support this position we present a computer model of opinion formation based on some novel assumptions, designed to bring the model closer to social reality. In our model, the agents, in addition to changing their opinions due to influence of the rest of society and external propaganda, have the ability to modify their social network, forming links with agents sharing the same opinions and cutting the links with those they disagree with. To improve the model further we divide the agents into "fanatics" and "opportunists," depending on how easy it is to change their opinions. The simulations show significant differences compared to traditional models, where network links are static. In particular, for the dynamical model where inter-agent links are adjustable, the final network structure and opinion distribution is shown to resemble real world observations, such as social structures and persistence of minority groups even when most of the society is against them and the propaganda is strong.

Persistent agents in Axelrod's social dynamics model

NASA Astrophysics Data System (ADS)

Reia, Sandro M.; Neves, Ubiraci P. C.

2016-01-01

Axelrod's model of social dynamics has been studied under the effect of external media. Here we study the formation of cultural domains in the model by introducing persistent agents. These are agents whose cultural traits are not allowed to change but may be spread through local neighborhood. In the absence of persistent agents, the system is known to present a transition from a monocultural to a multicultural regime at some critical Q (number of traits). Our results reveal a dependence of critical Q on the occupation probability p of persistent agents and we obtain the phase diagram of the model in the (p,Q) -plane. The critical locus is explained by the competition of two opposite forces named here barrier and bonding effects. Such forces are verified to be caused by non-persistent agents which adhere (adherent agents) to the set of traits of persistent ones. The adherence (concentration of adherent agents) as a function of p is found to decay for constant Q. Furthermore, adherence as a function of Q is found to decay as a power law with constant p.

Functionality study of santalin as tyrosinase inhibitor: A potential depigmentation agent.

PubMed

Hridya, Hemachandran; Amrita, Anantharaman; Mohan, Sankari; Gopalakrishnan, Mohan; Dakshinamurthy, Thirumal Kumar; Doss, George Priya; Siva, Ramamoorthy

2016-05-01

Excessive melanin production leads to hyperpigmentation disorders which results in distressing aesthetic values. Though there are some synthetic depigmentation agents available it has been reported to possess cytotoxic and mutagenic effects. Hence there is a need for the development of safe and non toxic natural tyrosinase inhibitors. Here we report the role of santalin, the chief constituent of Pterocarpus santalinus in inhibition of tyrosinase and melanin synthesis. Santalin inhibited tyrosinase activity dose dependently. Inhibitory kinetic studies revealed mixed type of inhibition with reversible mechanism. Santalin was found to interact with the fluorophore amino acid residue of tyrosinase. Analysis of circular dichroism spectra showed the binding of santalin to tyrosinase which induced the loss of secondary helical structure. Molecular docking result suggested that santalin interact with the catalytic core of tyrosinase through strong hydrogen and hydrophobic bonding. The results of in vitro studies showed santalin inhibited melanogenesis through down regulation of MITF, tyrosinase, TRP-1 and TRP-2 without any cytotoxic effects towards B16F0 melanoma cells. Therefore, our results suggested that santalin possesses anti-tyrosinase activity, which could be utilized as a safe depigmentation agent in the cosmetic field for the treatment of hyperpigmentation disorder. Copyright © 2016 Elsevier B.V. All rights reserved.

Potential of Microbispora sp. V2 as biocontrol agent against Sclerotium rolfsii, the causative agent of southern blight of Zea mays L (Baby corn)--in vitro studies.

PubMed

Patil, N N; Waghmode, M S; Gaikwad, P S; Gajbhiye, M H; Gunjal, A B; Nawani, N N; Kapadnis, B P

2014-11-01

The study was undertaken with the aim of exploring novel and beneficial agro activities of rare actinomycetes like Microbispora sp. V2. The antagonistic activity of Microbispora sp. V2 was evaluated as a biocontrol agents against Sclerotium rolfsii, a soil-borne fungal plant pathogen. The methodology performed for evaluation of biocontrol agent was in vitro evaluation assay which comprised of three tests viz., cellophane overlay technique, seed germination test and Thiram (fungicide) tolerance of Microbispora sp. V2. The isolate was found to inhibit the fungal pathogen Sclerotium rolfsii to 91.43% in cellophane assay. In seed germination assay, Microbispora sp. V2 treated seeds resulted in 25.75% increased germination efficiency, as compared to seeds infected by Sclerotium rolfsii. The isolate Microbispora sp. V2 could tolerate 1000 microg mL(-1) of Thiram (fungicide). The in vitro assay studies proved that Microbispora sp. V2 can be used as antifungal antagonist and thus posses' great potential as biocontrol agent against southern blight caused by Sclerotium rolfsii in Zea mays L (Baby corn) which causes large economical losses.

Pharmacotherapy for obesity: novel agents and paradigms

PubMed Central

Manning, Sean; Pucci, Andrea

2014-01-01

Public health initiatives focused on obesity prevention and lifestyle intervention programmes for patients with obesity have struggled to contain the obesity epidemic to date. In recent years, antiobesity drug therapies have had a limited role in clinical treatment algorithms for patients with obesity. Indeed, a number of high-profile antiobesity drug suspensions have markedly impacted upon the landscape of obesity pharmacotherapy. In this review, we discuss the advent of an increasing array of pharmacotherapeutic agents, which are effective both in inducing weight loss and in maintaining weight loss achieved by lifestyle measures. The development of these drugs as antiobesity agents has followed varying paths, ranging from lorcaserin, a selective serotonin agent, exploiting the beneficial central actions of fenfluramine but without the associated systemic side effects, to liraglutide, a gut hormone already used as a glucose-lowering drug but with appetite-suppressant properties, or the novel drug combination of phentermine/topiramate, two ‘old’ drugs used in lower doses than with previous therapeutic uses, resulting in an additive effect on weight loss and fewer side effects. We summarize the key findings from recent randomized controlled trials of these three drugs. Although these agents lead to clinically important weight loss when used as monotherapy, the use of antiobesity drugs as adjunctive therapy post intensive lifestyle intervention could prove to be the most successful strategy. Moreover, a progressive approach to obesity pharmacotherapy perhaps offers the best opportunity to finally address the obesity crisis on a mass scale. PMID:24790728

Peri-Prosthetic Knee Infection Management: Spacers Loaded with Two or Three Antibiotic Agents.

PubMed

Ortola, David Joaquin; Fenga, Domenico; Marcellino, Sandra; Rosi, Massimiliano; Centofanti, Francesco; Rosa, Michele Attilio

2017-07-01

The purpose of this work was to compare pre-made antibiotic-loaded spacers with two commercially available antibiotic agents and custom-made cements with three antibiotic agents added. We evaluated: (a) the validity of our procedures, (b) the control of the rate of infection in the long term, (c) complications, and (d) quality of life and patient satisfaction. A retrospective cohort study was performed on 112 consecutively treated patients between January 2010 and December 2013; 56 patients were treated with a pre-formed cement spacer (clindamycin + gentamicin), and 56 patients were treated with a spacer loaded with three antibiotic agents (clindamycin + gentamicin + vancomycin). Demographic data were collected: Classification of infection according to criteria of Cierny-Mader; microbiologic results; number of previous operations; and years of disease. Infection control or relapse after at least 18 months of follow-up was evaluated. Complications were recorded. Every patient completed the SF-36 test and Oxford Knee Score. With a follow-up of 32.87 months (standard deviation 12.04), at the end of treatment, amputation occurred in three of 112 patients because of recurrence of infection, and one patient died from other causes not related to the infection. The study population presented a rate of recurrence of infection of 2.70%. Our results suggest that a two stage re-implant with three antibiotic agents added to the spacer should be considered to avoid rescue procedures, especially in patients with multi-resistant micro-organism infections.

Etiologic agent of an epidemic of cutaneous leishmaniasis in Tolima, Colombia.

PubMed

Rodríguez-Barraquer, Isabel; Góngora, Rafael; Prager, Martín; Pacheco, Robinson; Montero, Luz Mery; Navas, Adriana; Ferro, Cristina; Miranda, Maria Consuelo; Saravia, Nancy G

2008-02-01

American cutaneous leishmaniasis (ACL) has been characterized as a zoonotic disease. However, peridomestic and domestic transmission have been recorded in at least nine countries in Central and South America. The present study was undertaken to identify the etiologic agent of a peridomestic epidemic of ACL in the Department of Tolima, Colombia. Leishmania isolates were obtained during the diagnosis of 56 patients with ACL who consulted the local leishmaniasis control program in three municipalities in Tolima. Species were identified using monoclonal antibodies and isoenzyme electrophoresis. A total of 53 (94.6%) of 56 isolates were identified as Leishmania (Viannia) guyanensis. Three isolates (5.4%) were identified as L. (V.) panamensis. Leishmania (V.) guyanensis is the probable etiologic agent of the largest epidemic of cutaneous leishmaniasis recorded in Colombia. This species has not previously been reported outside the Amazon and southeastern regions of Colombia, and has not been described in the peridomestic setting or linked with an epidemic.

Everolimus Plus Exemestane in Advanced Breast Cancer: Safety Results of the BALLET Study on Patients Previously Treated Without and with Chemotherapy in the Metastatic Setting.

PubMed

Generali, Daniele; Montemurro, Filippo; Bordonaro, Roberto; Mafodda, Antonino; Romito, Sante; Michelotti, Andrea; Piovano, Pierluigi; Ionta, Maria Teresa; Bighin, Claudia; Sartori, Donata; Frassoldati, Antonio; Cazzaniga, Marina Elena; Riccardi, Ferdinando; Testore, Franco; Vici, Patrizia; Barone, Carlo Antonio; Schirone, Alessio; Piacentini, Federico; Nolè, Franco; Molino, Annamaria; Latini, Luciano; Simoncini, Edda Lucia; Roila, Fausto; Cognetti, Francesco; Nuzzo, Francesco; Foglietta, Jennifer; Minisini, Alessandro Marco; Goffredo, Francesca; Portera, Giuseppe; Ascione, Gilda; Mariani, Gabriella

2017-06-01

The BALLET study was an open-label, multicenter, expanded access study designed to allow treatment with everolimus plus exemestane in postmenopausal women with hormone receptor-positive metastatic breast cancer progressed following prior endocrine therapy. A post hoc analysis to evaluate if previous chemotherapy in the metastatic setting affects the safety profile of the combination regimen of everolimus and exemestane was conducted on the Italian subset, as it represented the major part of the patients enrolled (54%). One thousand one hundred and fifty-one Italian patients were included in the present post hoc analysis, which focused on two sets of patients: patients who never received chemotherapy in the metastatic setting (36.1%) and patients who received at least one chemotherapy treatment in the metastatic setting (63.9%). One thousand one hundred and sixteen patients (97.0%) prematurely discontinued the study drug, and the main reasons reported were disease progression (39.1%), local reimbursement of everolimus (31.1%), and adverse events (AEs) (16.1%). The median duration of study treatment exposure was 139.5 days for exemestane and 135.0 days for everolimus. At least one AE was experienced by 92.5% of patients. The incidence of everolimus-related AEs was higher (83.9%) when compared with those that occurred with exemestane (29.1%), and the most commonly reported everolimus-related AE was stomatitis (51.3%). However, no significant difference in terms of safety related to the combination occurred between patients without and with chemotherapy in the metastatic setting. Real-life data of the Italian patients BALLET-related cohort were an adequate setting to state that previous chemotherapy did not affect the safety profile of the combination regimen of everolimus and exemestane. With the advent of new targeted agents for advanced or metastatic breast cancer, multiple lines of therapy may be possible, and components of the combined regimens can overlap from

Risk of retained placenta in women previously delivered by caesarean section: a population-based cohort study.

PubMed

Belachew, J; Cnattingius, S; Mulic-Lutvica, A; Eurenius, K; Axelsson, O; Wikström, A K

2014-01-01

To evaluate whether women with a caesarean section at their first delivery have an increased risk of retained placenta at their second delivery. Population-based cohort study. Sweden. All women with their first and second singleton deliveries in Sweden during the years 1994-2006 (n = 258,608). Women with caesarean section or placental abruption in their second pregnancy were not included in the study population. The risk of retained placenta at second delivery was estimated for women with a first delivery by caesarean section (n = 19,458), using women with a first vaginal delivery as reference (n = 239,150). Risks were calculated as odds ratios by unconditional logistic regression analysis with 95% confidence intervals (95%) after adjustments for maternal, delivery, and infant characteristics. Retained placenta with normal (≤1000 ml) and heavy (>1000 ml) bleeding. The overall rate of retained placenta was 2.07%. In women with a previous caesarean section and in women with previous vaginal delivery, the corresponding rates were 3.44% and 1.96%, respectively. Compared with women with a previous vaginal delivery, women with a previous caesarean section had an increased risk of retained placenta (adjusted OR 1.45; 95% CI 1.32-1.59), and the association was more pronounced for retained placenta with heavy bleeding (adjusted OR 1.61; 95% CI 1.44-1.79). Our report shows an increased risk for retained placenta in women previously delivered by caesarean section, a finding that should be considered in discussions of mode of delivery. © 2013 Royal College of Obstetricians and Gynaecologists.

Pain-relieving agents for infantile colic.

PubMed

Biagioli, Elena; Tarasco, Valentina; Lingua, Carla; Moja, Lorenzo; Savino, Francesco

2016-09-16

Infantile colic is a common disorder in the first months of life, affecting somewhere between 4% and 28% of infants worldwide, depending on geography and definitions used. Although it is self limiting and resolves by four months of age, colic is perceived by parents as a problem that requires action. Pain-relieving agents, such as drugs, sugars and herbal remedies, have been suggested as interventions to reduce crying episodes and severity of symptoms. To assess the effectiveness and safety of pain-relieving agents for reducing colic in infants younger than four months of age. We searched the following databases in March 2015 and again in May 2016: CENTRAL, Ovid MEDLINE, Embase and PsycINFO, along with 11 other databases. We also searched two trial registers, four thesis repositories and the reference lists of relevant studies to identify unpublished and ongoing studies. We included randomised controlled trials (RCTs) and quasi-RCTs evaluating the effects of pain-relieving agents given to infants with colic. We used the standard methodological procedures of The Cochrane Collaboration. We included 18 RCTs involving 1014 infants. All studies were small and at high risk of bias, often presenting major shortcomings across multiple design factors (e.g. selection, performance, attrition, lack of washout period).Three studies compared simethicone with placebo, and one with Mentha piperita; four studies compared herbal agents with placebo; two compared sucrose or glucose with placebo; five compared dicyclomine with placebo; and two compared cimetropium - one against placebo and the other at two different dosages. One multiple-arm study compared sucrose and herbal tea versus no treatment. Simethicone. Comparison with placebo revealed no difference in daily hours of crying reported for simethicone at the end of treatment in one small, low-quality study involving 27 infants. A meta-analysis of data from two cross-over studies comparing simethicone with placebo showed no

A pilot study: the efficacy of virgin coconut oil as ocular rewetting agent on rabbit eyes.

PubMed

Mutalib, Haliza Abdul; Kaur, Sharanjeet; Ghazali, Ahmad Rohi; Chinn Hooi, Ng; Safie, Nor Hasanah

2015-01-01

Purpose. An open-label pilot study of virgin coconut oil (VCO) was conducted to determine the safety of the agent as ocular rewetting eye drops on rabbits. Methods. Efficacy of the VCO was assessed by measuring NIBUT, anterior eye assessment, corneal staining, pH, and Schirmer value before instillation and at 30 min, 60 min, and two weeks after instillation. Friedman test was used to analyse any changes in all the measurable variables over the period of time. Results. Only conjunctival redness with instillation of saline agent showed significant difference over the period of time (P < 0.05). However, further statistical analysis had shown no significant difference at 30 min, 60 min, and two weeks compared to initial measurement (P > 0.05). There were no changes in the NIBUT, limbal redness, palpebral conjunctiva redness, corneal staining, pH, and Schirmer value over the period of time for each agent (P > 0.05). Conclusion. VCO acts as safe rewetting eye drops as it has shown no significant difference in the measurable parameter compared to commercial brand eye drops and saline. These study data suggest that VCO is safe to be used as ocular rewetting agent on human being.

A Pilot Study: The Efficacy of Virgin Coconut Oil as Ocular Rewetting Agent on Rabbit Eyes

PubMed Central

Mutalib, Haliza Abdul; Kaur, Sharanjeet; Ghazali, Ahmad Rohi; Chinn Hooi, Ng; Safie, Nor Hasanah

2015-01-01

Purpose. An open-label pilot study of virgin coconut oil (VCO) was conducted to determine the safety of the agent as ocular rewetting eye drops on rabbits. Methods. Efficacy of the VCO was assessed by measuring NIBUT, anterior eye assessment, corneal staining, pH, and Schirmer value before instillation and at 30 min, 60 min, and two weeks after instillation. Friedman test was used to analyse any changes in all the measurable variables over the period of time. Results. Only conjunctival redness with instillation of saline agent showed significant difference over the period of time (P < 0.05). However, further statistical analysis had shown no significant difference at 30 min, 60 min, and two weeks compared to initial measurement (P > 0.05). There were no changes in the NIBUT, limbal redness, palpebral conjunctiva redness, corneal staining, pH, and Schirmer value over the period of time for each agent (P > 0.05). Conclusion. VCO acts as safe rewetting eye drops as it has shown no significant difference in the measurable parameter compared to commercial brand eye drops and saline. These study data suggest that VCO is safe to be used as ocular rewetting agent on human being. PMID:25802534

Contrast echocardiography: new agents.

PubMed

Miller, Andrew P; Nanda, Navin C

2004-04-01

In this report, we review the history, rationale, current status and future directions of contrast agents in echocardiography. First, we discuss the historic development of contrast agents through a review of important physical principles of microbubbles in ultrasonography. Second, we identify attributes of an ideal contrast agent and review those that are currently available or in the "pipeline" for clinical use. Third, we review indications for contrast echocardiography, including endocardial border detection, perfusion quantification and reperfusion assessment, and validate these observations by comparisons with other imaging modalities. Then, we briefly review different methodologies of performing a contrast study, including interrupted, real-time and a hybrid modality. Finally, we identify novel future applications of the newest contrast agents. These newer concepts in contrast echocardiography should form a foundation for nearly limitless application of echocardiography in improved anatomical assessment, perfusion imaging and even special applications, such as detection of vascular inflammation and site-specific drug delivery.

Exogenous contrast agents for thermoacoustic imaging: An investigation into the underlying sources of contrast

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ogunlade, Olumide, E-mail: o.ogunlade@ucl.ac.uk; Beard, Paul

2015-01-15

Purpose: Thermoacoustic imaging at microwave excitation frequencies is limited by the low differential contrast exhibited by high water content tissues. To overcome this, exogenous thermoacoustic contrast agents based on gadolinium compounds, iron oxide, and single wall carbon nanotubes have previously been suggested and investigated. However, these previous studies did not fully characterize the electric, magnetic, and thermodynamic properties of these agents thus precluding identification of the underlying sources of contrast. To address this, measurements of the complex permittivity, complex permeability, DC conductivity, and Grüneisen parameter have been made. These measurements allowed the origins of the contrast provided by each substancemore » to be identified. Methods: The electric and magnetic properties of the contrast agents were characterized at 3 GHz using two rectangular waveguide cavities. The DC conductivity was measured separately using a conductivity meter. Thermoacoustic signals were then acquired and compared to those generated in water. Finally, 3D electromagnetic simulations were used to decouple the different contributions to the absorbed power density. Results: It was found that the gadolinium compounds provided appreciable electric contrast but not originating from the gadolinium itself. The contrast was either due to dissociation of the gadolinium salt which increased ionic conductivity or its nondissociated polar fraction which increased dielectric polarization loss or a combination of both. In addition, very high concentrations were required to achieve appreciable contrast, to the extent that the Grüneisen parameter increased significantly and became a source of contrast. Iron oxide particles were found to produce low but measurable dielectric contrast due to dielectric polarization loss, but this is attributed to the coating of the particles not the iron oxide. Single wall carbon nanotubes did not provide measurable contrast of any

Adoption of innovations with contrarian agents and repentance

NASA Astrophysics Data System (ADS)

Gordon, Mirta B.; Laguna, M. F.; Gonçalves, S.; Iglesias, J. R.

2017-11-01

The dynamics of adoption of innovations is an important subject in many fields and areas, like technological development, industrial processes, social behavior, fashion or marketing. The number of adopters of a new technology generally increases following a kind of logistic function. However, empirical data provide evidences that this behavior may be more complex, as many factors influence the decision to adopt an innovation. On the one hand, although some individuals are inclined to adopt an innovation if many people do the same, there are others who act in the opposite direction, trying to differentiate from the ;herd;. People who prefer to behave like the others are called mimetic, whereas individuals who resist adopting new products, the stronger the greater the number of adopters, are named contrarians. Besides, in the real world new adopters may have second thoughts and change their decisions accordingly. In this contribution we include this possibility by means of repentance, a feature which was absent in previous models. The model of adoption of an innovation has all the ingredients of a previous version, in which the agents decision to adopt depends on the appeal of the novelty, the inertia or resistance to adopt it, and the social interactions with other agents, but now agents can repent and turn back to the old technology. We present analytic calculations and numerical simulations to determine the conditions for the establishment of the new technology. The inclusion of repentance can modify the balance between the global incentive to adopt and the number of contrarians who prevent full adoption, generating a rich landscape of temporal evolution that includes cycles of adoption.

Facile synthesis and biological evaluation of novel symmetrical biphenyls as antitumor agents.

PubMed

Zhang, Jie; Zhang, Yanmin; Pan, Xiaoyan; Wang, Chen; Hu, Zhigang; Wang, Sicen; He, Langchong

2012-03-01

As a continuation to our previous work in developing anticancer agents, eighteen symmetrical biphenyl derivatives structurally related to taspine were synthesized and evaluated in vitro and in vivo. All the compounds were prepared with varied substitutions in the phenyl ring of aniline moiety. The cytotoxicity and anticancer activity of biphenyls was evaluated against various human tumor and normal cell line. Antiproliferative assays indicated that some of them exhibited potent anticancer activity. The potent antiproliferative activity of these compounds against ECV304 suggested that these biphenyls could be served as antiangiogenic agents. The highly active compound (2) also exhibited potent growth inhibition against cancer cell lines in vivo. Our findings demonstrated that these symmetrical biphenyl derivatives would be a promising candidate as novel anticancer agents.

Effect of Addition of Antifungal Agents on Physical and Biological Properties of a Tissue Conditioner: An In-Vitro Study.

PubMed

Rawat, Pragati; Agarwal, Swatantra; Tripathi, Siddhi

2017-09-01

Purpose: Tissue conditioners are used for healing of abused oral tissues. They may harbour microorganisms causing oral diseases such as candidiasis compromising the health of the patient. Also, addition of antifungal agents into tissue conditioner may alter its properties. This study compares the anti-fungal property and mechanical properties of tissue conditioner containing different antifungal agents. Methods: Three antifungal agents, one synthetic - fluconazole, and two natural - oregano oil and virgin coconut oil were added into the tissue conditioner (Viscogel) in different concentrations. The antifungal property, tensile bond strength and viscoelasticity of Viscogel containing these antifungal agents were assessed after 24 hours, three days and seven days. Results: While, the highest antifungal activity was shown by Viscogel containing fluconazole, the maximum tensile bond strength was found to be of Viscogel alone (control). Although Viscogel alone and in combination of fluconazole showed deterioration in viscoelasticity, Viscogel in combination of natural agents showed no significant changes over the period of seven days. Conclusion: Incorporation of the natural agents in the tissue conditioner can be used as an effective alternative to systemic or topical synthetic antifungal agents.

Mathematical modeling of malaria infection with innate and adaptive immunity in individuals and agent-based communities.

PubMed

Gurarie, David; Karl, Stephan; Zimmerman, Peter A; King, Charles H; St Pierre, Timothy G; Davis, Timothy M E

2012-01-01

Agent-based modeling of Plasmodium falciparum infection offers an attractive alternative to the conventional Ross-Macdonald methodology, as it allows simulation of heterogeneous communities subjected to realistic transmission (inoculation patterns). We developed a new, agent based model that accounts for the essential in-host processes: parasite replication and its regulation by innate and adaptive immunity. The model also incorporates a simplified version of antigenic variation by Plasmodium falciparum. We calibrated the model using data from malaria-therapy (MT) studies, and developed a novel calibration procedure that accounts for a deterministic and a pseudo-random component in the observed parasite density patterns. Using the parasite density patterns of 122 MT patients, we generated a large number of calibrated parameters. The resulting data set served as a basis for constructing and simulating heterogeneous agent-based (AB) communities of MT-like hosts. We conducted several numerical experiments subjecting AB communities to realistic inoculation patterns reported from previous field studies, and compared the model output to the observed malaria prevalence in the field. There was overall consistency, supporting the potential of this agent-based methodology to represent transmission in realistic communities. Our approach represents a novel, convenient and versatile method to model Plasmodium falciparum infection.

Advances in the Preclinical Study of Some Flavonoids as Potential Antidepressant Agents

PubMed Central

German-Ponciano, León Jesús; Rosas-Sánchez, Gilberto Uriel; Rivadeneyra-Domínguez, Eduardo

2018-01-01

Flavonoids are phenolic compounds found commonly in plants that protect them against the negative effects of environmental insults. These secondary metabolites have been widely studied in preclinical research because of their biological effects, particularly as antioxidant agents. Diverse flavonoids have been studied to explore their potential therapeutic effects in the treatment of disorders of the central nervous system, including anxiety and depression. The present review discusses advances in the study of some flavonoids as potential antidepressant agents. We describe their behavioral, physiological, and neurochemical effects and the apparent mechanism of action of their preclinical antidepressant-like effects. Natural flavonoids produce antidepressant-like effects in validated behavioral models of depression. The mechanism of action of these effects includes the activation of serotonergic, dopaminergic, noradrenergic, and γ-aminobutyric acid-ergic neurotransmitter systems and an increase in the production of neural factors, including brain-derived neurotrophic factor and nerve growth factor. Additionally, alterations in the function of tropomyosin receptor kinase B and activity of the enzyme monoamine oxidase A have been reported. In conclusion, preclinical research supports the potential antidepressant effects of some natural flavonoids, which opens new possibilities of evaluating these substances to develop complementary therapeutic alternatives that could ameliorate symptoms of depressive disorders in humans. PMID:29623232

Feasibility Study for the Use of Green, Bio-Based, Efficient Reactive Sorbent Material to Neutralize Chemical Warfare Agents

DTIC Science & Technology

2012-08-02

REPORT Feasibility study for the use of green, bio-based, efficient reactive sorbent material to neutralize chemical warfare agents 14. ABSTRACT 16...way cellulose, lignin and hemicelluloses interact as well as whole wood dissolution occurs in ILs. The present project was conducted to 1. REPORT...Feasibility study for the use of green, bio-based, efficient reactive sorbent material to neutralize chemical warfare agents Report Title ABSTRACT Over the

Rural-urban migration including formal and informal workers in the urban sector: an agent-based numerical simulation study

NASA Astrophysics Data System (ADS)

Branco, Nilton; Oliveira, Tharnier; Silveira, Jaylson

2012-02-01

The goal of this work is to study rural-urban migration in the early stages of industrialization. We use an agent-based model and take into account the existence of informal and formal workers on the urban sector and possible migration movements, dependent on the agents' social and private utilities. Our agents are place on vertices of a square lattice, such that each vertex has only one agent. Rural, urban informal and urban formal workers are represented by different states of a three-state Ising model. At every step, a fraction a of the agents may change sectors or migrate. The total utility of a given agent is then calculated and compared to a random utility, in order to check if this agent turns into an actual migrant or changes sector. The dynamics is carried out until an equilibrium state is reached and equilibrium variables are then calculated and compared to available data. We find that a generalized Harris-Todaro condition is satisfied [1] on these equilibrium regimes, i.e, the ratio between expected wages between any pair of sectors reach a constant value. [4pt] [1] J. J. Silveira, A. L. Esp'indola and T. J. Penna, Physica A, 364, 445 (2006).

Riot Control Agents

MedlinePlus

... Submit What's this? Submit Button Facts About Riot Control Agents Interim document Recommend on Facebook Tweet Share Compartir What riot control agents are Riot control agents (sometimes referred to ...

Major bleeding events and risk stratification of antithrombotic agents in hemodialysis: Results from the DOPPS

PubMed Central

Sood, Manish M.; Larkina, Maria; Thumma, Jyothi R.; Tentori, Francesca; Gillespie, Brenda W.; Fukuhara, Shunichi; Mendelssohn, David C.; Chan, Kevin; de Sequera, Patricia; Komenda, Paul; Rigatto, Claudio; Robinson, Bruce M.

2013-01-01

Benefits and risks of antithrombotic agents remain unclear in the hemodialysis population. We aimed to determine variation in antithrombotic agent use, rates of major bleeding events, and to determine factors predictive of stroke and bleeding to allow for risk stratification, enabling more rational decisions about using antithrombotic agents. The sample included 48,144 patients in 12 countries in the Dialysis Outcomes and Practice Patterns Study Phase I–IV. Antithrombotic agents included oral anticoagulants (OAC), ASA and anti-platelet agents (APA). OAC prescription, comorbidities and vascular access were assessed at study entry; data on clinical events including hospitalization due to bleeding were collected every four months during follow-up. There was wide variation in OAC (0.3–18%), APA (3–25%) and ASA use (8–36%), and major bleeding rates (0.05–0.22 events/year) among countries. Rates of all-cause mortality, cardiovascular mortality, and bleeding events requiring hospitalization were elevated in patients prescribed OAC across adjusted models. The CHADS2 score predicted the risk of stroke in atrial fibrillation patients. Gastrointestinal bleeding in the past 12 months was highly predictive of major bleeding events; for patients with previous gastrointestinal bleeding, the rate of bleeding exceeded the rate of stroke by at least 2-fold across categories of CHADS2 score. Prescription of antithrombotic agents varied greatly. The CHADS2 score and a history of gastrointestinal bleeding were predictive of stroke and bleeding events, respectively, with bleeding rates substantially exceeding stroke rates in all groups including patients at high stroke risk. Appropriate risk stratification and a cautious approach should be considered before OAC use in the dialysis population. PMID:23677245

A case study of preservation of semi-solid preparations using the European Pharmacopoeia test: comparative efficacy of antimicrobial agents in zinc gelatin.

PubMed

Favet, J; Chappuis, M L; Doelker, E

2001-09-01

The present study was undertaken with the aim of finding an alternative preservative system to methyl parahydroxybenzoate in zinc gelatin, which was described in the monographs of the Swiss Pharmacopoeia (until Ph. Helv. 8) and in previous editions of the German Pharmacopoeia (until DAB 7). This antimicrobial agent has now been withdrawn in the DAB, because of its potential allergy risks. As for the USP and DAB-DDR zinc gelatin preparations, they have always been devoid of any preservative agent, probably relying on the mild antimicrobial activity of zinc. A literature survey did not reveal if such an aqueous preparation containing the water-insoluble zinc oxide shows efficacious antimicrobial activity by itself. Thus, a comparative evaluation of differently preserved zinc gelatin preparations was performed using a test for the efficacy of antimicrobial preservation that has been modified with regard to the European Pharmacopoeia (EP) test to take into account the solid state of the preparations and the bactericidal effect of the zinc. Three zinc gelatin preparations were checked, either: (i), without any agent; or (ii), with 0.1% methyl parahydroxybenzoate; or (iii), with 0.5% phenoxyethanol, a broad-spectrum antimicrobial agent almost devoid of allergy risks. The three preparations behave quite differently, in particular with respect to fungi. All three preparations passed the modified EP test as far as bacteria are concerned. Even zinc gelatin without preservative is very effective, not only because of the mild antimicrobial activity of zinc (the soluble fraction of zinc oxide in the liquid phase of zinc gelatin was determined to be 13 microg/ml), but most probably because of the low water activity of the preparation (measured as around 0.81), as shown by the absence of growth of a zinc-resistant strain of Pseudomonas aeruginosa. Zinc gelatin preserved with methyl parahydroxybenzoate has a weak, although satisfactory, activity against Staphylococcus aureus

Information-Seeking Practices of County Extension Agents

ERIC Educational Resources Information Center

Bailey, Nikki; Hill, Alexandra; Arnold, Shannon

2014-01-01

The purpose of the study reported here was to examine the educational resources used by Montana State University Extension county agents. An online survey was administered to evaluate agents' informational needs. Agents reported client questions (93.8%) and program/workshop planning and presentations (91.7%) as the main reasons for seeking…

New antithrombotic agents in the ambulatory setting.

PubMed

Gibbs, Neville M; Weightman, William M; Watts, Stephen A

2014-12-01

Many patients presenting for surgical or other procedures in an ambulatory setting are taking new antiplatelet or anticoagulant agents. This review assesses how the novel features of these new agents affect the management of antithrombotic therapy in the ambulatory setting. There have been very few studies investigating the relative risks of continuing or ceasing new antithrombotic agents. Recent reviews indicate that the new antithrombotic agents offer greater efficacy or ease of administration but are more difficult to monitor or reverse. They emphasize the importance of assessing the bleeding risk of the procedure, the thrombotic risk if the agent is ceased, and patient factors that increase the likelihood of bleeding. The timing of cessation of the agent, if required, depends on its pharmacokinetics and patients' bleeding risks. Patients at high risk of thrombotic complications may require bridging therapy. Once agreed upon, the perioperative plan should be made clear to all involved. As there are few clinical studies to guide management, clinicians must make rational decisions in relation to continuing or ceasing new antithrombotic agents. This requires knowledge of their pharmacokinetics, and a careful multidisciplinary assessment of the relative thrombotic and bleeding risks in individual patients.

Influence of anti-adhesive agent on incidence of bile leakage after liver resection: A prospective cohort study.

PubMed

Yu, Young-Dong; Kim, Dong-Sik; Jung, Sung-Won; Han, Jae-Hyun; Suh, Sung-Ock

2016-07-01

Anti-adhesive agents are increasingly used to reduce the incidence of postoperative adhesions following abdominal surgery. Bile leakage after liver resection remains a major cause of postoperative morbidity. The aim of this study was to examine the effect of anti-adhesive agent on bile leakage after liver resection. 77 patients were enrolled to receive an anti-adhesive agent (study group) during liver resection between May 2012 and August 2013. The study group was compared to a match-paired control group. Clinical data were collected including bilirubin concentration in serum and drain fluid and bile leakage rate. In addition, a separate analysis was performed between patients with and without postoperative bile leakage. There was no difference in bile leakage rate or hospital stay between the study group (n = 77) and control group (n = 77). Of the total number of patients (n = 154), there were 29 patients with postoperative bile leak and 125 patients without bile leak. On univariate analysis, patients without history of hepatitis were significantly associated with bile leakage. In addition, liver resection with broader cut surface area was associated with bile leakage. Application of anti-adhesive agent was not associated with bile leakage. On multivariate analysis, resection with broader cut surface area (OR = 2.788, p = 0.026) and patients without history of hepatitis (OR = 5.153, p = 0.039) were significantly associated with bile leakage. Larger area of cut-surface and patients without history of hepatitis were significant risk factors for bile leakage. The use of anti-adhesive agent was not associated with increased risk of bile leakage. Copyright © 2016 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

The Use of Published Clinical Study Reports to Support U.S. Food and Drug Administration Approval of Imaging Agents.

PubMed

Rieves, Dwaine; Jacobs, Paula

2016-12-01

Pharmaceutical companies typically perform prospective, multicenter phase 3 clinical studies to support approval of a new imaging agent by the U.S. Food and Drug Administration (FDA). In uncommon situations, the FDA has approved imaging agents based solely, or in large part, on the clinical study experience described in published reports, including reports of exploratory (i.e., phase 1 or 2) studies performed at a single clinical site. We performed a survey of published reports to assess the potential of the reported information to support FDA approval of a commonly cited investigational imaging agent. Our survey revealed critical data limitations in most publications, all of which reported exploratory clinical studies. Here we summarize the precedent for FDA approval of imaging agents using effectiveness data from publications, FDA guidance, and our experience in reviewing publications. We also present a key-data checklist for investigators to consider in the design, conduct, and reporting of exploratory clinical studies for publication. We encourage editors and peer reviewers to consider requiring these key data when reviewing these reports for publication. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Continuum mechanics analysis of fracture progression in the vitrified cryoprotective agent DP6

PubMed Central

Steif, Paul S.; Palastro, Matthew C.; Rabin, Yoed

2008-01-01

As part of an ongoing effort to study the continuum mechanics effects associated with cryopreservation, the current report focuses on the prediction of fracture formation in cryoprotective agents. Fractures had been previously observed in 1 mℓ samples of the cryoprotective agent cocktail DP6, contained in a standard 15 mℓ glass vial, and subjected to various cooling rates. These experimental observations were obtained by means of a cryomacroscope, which has been recently presented by the current research team. High and low cooling rates were found to produce very distinct patterns of cracking. The current study seeks to explain the observed patterns on the basis of stresses predicted from finite element analysis, which relies on a simple viscoelastic constitutive model and on estimates of the critical stress for cracking. The current study demonstrates that the stress which results in instantaneous fracture at low cooling rates is consistent with the stress to initiate fracture at high cooling rate. This consistency supports the credibility of the proposed constitutive model and analysis, and the unified criterion for fracturing, that is, a critical stress threshold. PMID:18412493

The sources, fate, and toxicity of chemical warfare agent degradation products.

PubMed Central

Munro, N B; Talmage, S S; Griffin, G D; Waters, L C; Watson, A P; King, J F; Hauschild, V

1999-01-01

We include in this review an assessment of the formation, environmental fate, and mammalian and ecotoxicity of CW agent degradation products relevant to environmental and occupational health. These parent CW agents include several vesicants: sulfur mustards [undistilled sulfur mustard (H), sulfur mustard (HD), and an HD/agent T mixture (HT)]; nitrogen mustards [ethylbis(2-chloroethyl)amine (HN1), methylbis(2-chloroethyl)amine (HN2), tris(2-chloroethyl)amine (HN3)], and Lewisite; four nerve agents (O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate (VX), tabun (GA), sarin (GB), and soman (GD)); and the blood agent cyanogen chloride. The degradation processes considered here include hydrolysis, microbial degradation, oxidation, and photolysis. We also briefly address decontamination but not combustion processes. Because CW agents are generally not considered very persistent, certain degradation products of significant persistence, even those that are not particularly toxic, may indicate previous CW agent presence or that degradation has occurred. Of those products for which there are data on both environmental fate and toxicity, only a few are both environmentally persistent and highly toxic. Major degradation products estimated to be of significant persistence (weeks to years) include thiodiglycol for HD; Lewisite oxide for Lewisite; and ethyl methyl phosphonic acid, methyl phosphonic acid, and possibly S-(2-diisopropylaminoethyl) methylphosphonothioic acid (EA 2192) for VX. Methyl phosphonic acid is also the ultimate hydrolysis product of both GB and GD. The GB product, isopropyl methylphosphonic acid, and a closely related contaminant of GB, diisopropyl methylphosphonate, are also persistent. Of all of these compounds, only Lewisite oxide and EA 2192 possess high mammalian toxicity. Unlike other CW agents, sulfur mustard agents (e.g., HD) are somewhat persistent; therefore, sites or conditions involving potential HD contamination should include an

Ultrasound Contrast Agents

NASA Astrophysics Data System (ADS)

Cachard, Christian; Basset, Olivier

While the use of contrast agents in other imaging modalities (X ray, MRI, PET, …) has been routinely accepted for many years, the development and commercialization of contrast agents designed specifically for ultrasound imaging has occurred only very recently. As in the other imaging modalities, the injection of contrast agents during an ultrasound examination is intended to facilitate the detection and diagnosis of specific pathologies. Contrast agents efficiency is based on the backscattering of ultrasound by microbubbles. These microparticules are intravenously injected in the blood flow. After an introduction and generalities on ultrasound contrast agents (UCA) the microbubble physics in an acoustic field will be developed. Second, physics characteristics of contrast agents will be compared (bubbles with or without shell, gas nature, size distribution). Influence of acoustic pressure on the behaviour of the microparticules (linear, non linear and destruction) will be discussed. Finally, a review of specific imaging adapted to contrast agent properties as harmonic imaging, pulse inversion imaging will be presented.

Study on the influence of the decoking agent on the activity of limestone in wet flue gas desulfurization

NASA Astrophysics Data System (ADS)

Li, Qianjun; Xu, Dongyang; Wu, Yunxia; Yu, Jin

2017-01-01

Influence of the main components of decoking agent (magnesium nitrate, aluminum nitrate, copper nitrate, ammonium nitrate and actual decoking agent) on the activity of limestone is studied in laboratory by MET method. Results show that magnesium nitrate, ammonium nitrate and copper nitrate almost has no effect on the activity of limestone. With the concentration increasing, aluminum nitrate has an increasing inhibition on the dissolution of limestone. Fly ash has inhibition on dissolution of limestone due to the blockage of limestone pore by fly ash. The actual decoking agent has almost no effect on the limestone.

Remote Agent Demonstration

NASA Technical Reports Server (NTRS)

Dorais, Gregory A.; Kurien, James; Rajan, Kanna

1999-01-01

We describe the computer demonstration of the Remote Agent Experiment (RAX). The Remote Agent is a high-level, model-based, autonomous control agent being validated on the NASA Deep Space 1 spacecraft.

“Design characteristics of the CORRONA CERTAIN study: a comparative effectiveness study of biologic agents for rheumatoid arthritis patients”

PubMed Central

2014-01-01

Background Comparative effectiveness research has recently attracted considerable attention. The Comparative Effectiveness Registry to study Therapies for Arthritis and Inflammatory Conditions (CERTAIN) is an ongoing prospective cohort study of adult patients with Rheumatoid Arthritis (RA). Methods/Design CERTAIN uses the existing Consortium of Rheumatology Researchers of North America (CORRONA) network of participating private and academic sites in order to recruit patients fulfilling the 1987 ACR criteria that have at least moderate disease activity. Patients starting or switching biologic agents either anti-TNF therapy or a non anti-TNF biologic are eligible for enrollment, depending on the treatment selected by their physician. Enrollment is expected to be completed by March of 2014, and 2711 patients will participate in the study. As of October 7th 2013, 2234 patients have been enrolled. Patient visits and laboratory blood work are mandated every three months for one year. Safety data is collected through one year and beyond. The primary comparative effectiveness endpoint is attainment of low RA disease activity at one year among patients who have been exposed to at least one prior TNF-α inhibitor agent prior to enrollment. Multiple secondary effectiveness and safety endpoints will be addressed by investigating the entire population enrolled (naïve and biologic experienced). Discussion The unique design features of CERTAIN will inform comparative effectiveness and safety questions for choosing biologic agents for the management of RA. PMID:24690143

Genomic phenotyping by barcode sequencing broadly distinguishes between alkylating agents, oxidizing agents, and non-genotoxic agents, and reveals a role for aromatic amino acids in cellular recovery after quinone exposure.

PubMed

Svensson, J Peter; Quirós Pesudo, Laia; McRee, Siobhan K; Adeleye, Yeyejide; Carmichael, Paul; Samson, Leona D

2013-01-01

Toxicity screening of compounds provides a means to identify compounds harmful for human health and the environment. Here, we further develop the technique of genomic phenotyping to improve throughput while maintaining specificity. We exposed cells to eight different compounds that rely on different modes of action: four genotoxic alkylating (methyl methanesulfonate (MMS), N-Methyl-N-nitrosourea (MNU), N,N'-bis(2-chloroethyl)-N-nitroso-urea (BCNU), N-ethylnitrosourea (ENU)), two oxidizing (2-methylnaphthalene-1,4-dione (menadione, MEN), benzene-1,4-diol (hydroquinone, HYQ)), and two non-genotoxic (methyl carbamate (MC) and dimethyl sulfoxide (DMSO)) compounds. A library of S. cerevisiae 4,852 deletion strains, each identifiable by a unique genetic 'barcode', were grown in competition; at different time points the ratio between the strains was assessed by quantitative high throughput 'barcode' sequencing. The method was validated by comparison to previous genomic phenotyping studies and 90% of the strains identified as MMS-sensitive here were also identified as MMS-sensitive in a much lower throughput solid agar screen. The data provide profiles of proteins and pathways needed for recovery after both genotoxic and non-genotoxic compounds. In addition, a novel role for aromatic amino acids in the recovery after treatment with oxidizing agents was suggested. The role of aromatic acids was further validated; the quinone subgroup of oxidizing agents were extremely toxic in cells where tryptophan biosynthesis was compromised.

Anabolic agents and bone quality.

PubMed

Sibai, Tarek; Morgan, Elise F; Einhorn, Thomas A

2011-08-01

The definition of bone quality is evolving particularly from the perspective of anabolic agents that can enhance not only bone mineral density but also bone microarchitecture, composition, morphology, amount of microdamage, and remodeling dynamics. This review summarizes the molecular pathways and physiologic effects of current and potential anabolic drugs. From a MEDLINE search (1996-2010), articles were identified by the search terms "bone quality" (1851 articles), "anabolic agent" (5044 articles), "PTH or parathyroid hormone" (32,229 articles), "strontium" or "strontium ranelate" (283 articles), "prostaglandin" (77,539 articles), and "statin" or "statins" (14,233 articles). The search strategy included combining each with the phrase "bone quality." Another more limited search aimed at finding more novel potential agents. Parathyroid hormone is the only US Food and Drug Administration-approved bone anabolic agent in the United States and has been the most extensively studied in in vitro animal and human trials. Strontium ranelate is approved in Europe but has not undergone Food and Drug Administration trials in the United States. All the studies on prostaglandin agonists have used in vivo animal models and there are no human trials examining prostaglandin agonist effects. The advantages of statins include the long-established advantages and safety profile, but they are limited by their bioavailability in bone. Other potential pathways include proline-rich tyrosine kinase 2 (PYK2) and sclerostin (SOST) inhibition, among others. The ongoing research to enhance the anabolic potential of current agents, identify new agents, and develop better delivery systems will greatly enhance the management of bone quality-related injuries and diseases in the future.

[Decontamination of chemical warfare agents by photocatalysis].

PubMed

Hirakawa, Tsutomu; Mera, Nobuaki; Sano, Taizo; Negishi, Nobuaki; Takeuchi, Koji

2009-01-01

Photocatalysis has been widely applied to solar-energy conversion and environmental purification. Photocatalyst, typically titanium dioxide (TiO(2)), produces active oxygen species under irradiation of ultraviolet light, and can decompose not only conventional pollutants but also different types of hazardous substances at mild conditions. We have recently started the study of photocatalytic decontamination of chemical warfare agents (CWAs) under collaboration with the National Research Institute of Police Science. This article reviews environmental applications of semiconductor photocatalysis, decontamination methods for CWAs, and previous photocatalytic studies applied to CWA degradation, together with some of our results obtained with CWAs and their simulant compounds. The data indicate that photocatalysis, which may not always give a striking power, certainly helps detoxification of such hazardous compounds. Unfortunately, there are not enough data obtained with real CWAs due to the difficulty in handling. We will add more scientific data using CWAs in the near future to develop useful decontamination systems that can reduce the damage caused by possible terrorism.

The effect of antimicrobial agents on bond strength of orthodontic adhesives: a meta-analysis of in vitro studies.

PubMed

Altmann, A S P; Collares, F M; Leitune, V C B; Samuel, S M W

2016-02-01

Antimicrobial orthodontic adhesives aim to reduce white spot lesions' incidence in orthodontic patients, but they should not jeopardizing its properties. Systematic review and meta-analysis were performed to answer the question whether the association of antimicrobial agents with orthodontic adhesives compromises its mechanical properties and whether there is a superior antimicrobial agent. PubMed and Scopus databases. In vitro studies comparing shear bond strength of conventional photo-activated orthodontic adhesives to antimicrobial photo-activated orthodontic adhesives were considered eligible. Search terms included the following: orthodontics, orthodontic, antimicrobial, antibacterial, bactericidal, adhesive, resin, resin composite, bonding agent, bonding system, and bond strength. The searches yielded 494 citations, which turned into 467 after duplicates were discarded. Titles and abstracts were read and 13 publications were selected for full-text reading. Twelve studies were included in the meta-analysis. The global analysis showed no statistically significant difference between control and experimental groups. In the subgroup analysis, only the chlorhexidine subgroup showed a statistically significant difference, where the control groups had higher bond strength than the experimental groups. Many studies on in vitro orthodontic bond strength fail to report test conditions that could affect their outcomes. The pooled in vitro data suggest that adding an antimicrobial agent to an orthodontic adhesive system does not influence bond strength to enamel. It is not possible to state which antimicrobial agent is better to be associated. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Neuroprotective "agents" in surgery. Secret "agent" man, or common "agent" machine?

NASA Technical Reports Server (NTRS)

Andrews, R. J.

1999-01-01

The search for clinically-effective neuroprotective agents has received enormous support in recent years--an estimated $200 million by pharmaceutical companies on clinical trials for traumatic brain injury alone. At the same time, the pathophysiology of brain injury has proved increasingly complex, rendering the likelihood of a single agent "magic bullet" even more remote. On the other hand, great progress continues with technology that makes surgery less invasive and less risky. One example is the application of endovascular techniques to treat coronary artery stenosis, where both the invasiveness of sternotomy and the significant neurological complication rate (due to microemboli showering the cerebral vasculature) can be eliminated. In this paper we review aspects of intraoperative neuroprotection both present and future. Explanations for the slow progress on pharmacologic neuroprotection during surgery are presented. Examples of technical advances that have had great impact on neuroprotection during surgery are given both from coronary artery stenosis surgery and from surgery for Parkinson's disease. To date, the progress in neuroprotection resulting from such technical advances is an order of magnitude greater than that resulting from pharmacologic agents used during surgery. The progress over the last 20 years in guidance during surgery (CT and MRI image-guidance) and in surgical access (endoscopic and endovascular techniques) will soon be complemented by advances in our ability to evaluate biological tissue intraoperatively in real-time. As an example of such technology, the NASA Smart Probe project is considered. In the long run (i.e., in 10 years or more), pharmacologic "agents" aimed at the complex pathophysiology of nervous system injury in man will be the key to true intraoperative neuroprotection. In the near term, however, it is more likely that mundane "agents" based on computers, microsensors, and microeffectors will be the major impetus to improved

Effective Treatment of Folliculitis Decalvans Using Selected Antimicrobial Agents

PubMed Central

Sillani, Caulloo; Bin, Zhang; Ying, Zhao; Zeming, Cai; Jian, Yang; Xingqi, Zhang

2010-01-01

Folliculitis Decalvans (FD) is a rare neutrophilic infammation of the scalp characterized by painful, recurrent purulent follicular exudation resulting in primary cicatricial alopecia. However, unclear etiology makes FD treatment a difficult task. A wide variety of topical and systemic agents have been tried previously, with varied results. We present here a case series report of a set of 13 patients with FD on antimicrobial therapy. PMID:21188019

Reevaluation of 1999 Health-Based Environmental Screening Levels (HBESLs) for Chemical Warfare Agents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watson, Annetta Paule; Dolislager, Fredrick G

2007-05-01

This report evaluates whether new information and updated scientific models require that changes be made to previously published health-based environmental soil screening levels (HBESLs) and associated environmental fate/breakdown information for chemical warfare agents (USACHPPM 1999). Specifically, the present evaluation describes and compares changes that have been made since 1999 to U.S. Environmental Protection Agency (EPA) risk assessment models, EPA exposure assumptions, as well as to specific chemical warfare agent parameters (e.g., toxicity values). Comparison was made between screening value estimates recalculated with current assumptions and earlier health-based environmental screening levels presented in 1999. The chemical warfare agents evaluated include themore » G-series and VX nerve agents and the vesicants sulfur mustard (agent HD) and Lewisite (agent L). In addition, key degradation products of these agents were also evaluated. Study findings indicate that the combined effect of updates and/or changes to EPA risk models, EPA default exposure parameters, and certain chemical warfare agent toxicity criteria does not result in significant alteration to the USACHPPM (1999) health-based environmental screening level estimates for the G-series and VX nerve agents or the vesicant agents HD and L. Given that EPA's final position on separate Tier 1 screening levels for indoor and outdoor worker screening assessments has not yet been released as of May 2007, the study authors find that the 1999 screening level estimates (see Table ES.1) are still appropriate and protective for screening residential as well as nonresidential sites. As such, risk management decisions made on the basis of USACHPPM (1999) recommendations do not require reconsideration. While the 1999 HBESL values are appropriate for continued use as general screening criteria, the updated '2007' estimates (presented below) that follow the new EPA protocols currently under development are also

Introduction to Agent Mining Interaction and Integration

NASA Astrophysics Data System (ADS)

Cao, Longbing

In recent years, more and more researchers have been involved in research on both agent technology and data mining. A clear disciplinary effort has been activated toward removing the boundary between them, that is the interaction and integration between agent technology and data mining. We refer this to agent mining as a new area. The marriage of agents and data mining is driven by challenges faced by both communities, and the need of developing more advanced intelligence, information processing and systems. This chapter presents an overall picture of agent mining from the perspective of positioning it as an emerging area. We summarize the main driving forces, complementary essence, disciplinary framework, applications, case studies, and trends and directions, as well as brief observation on agent-driven data mining, data mining-driven agents, and mutual issues in agent mining. Arguably, we draw the following conclusions: (1) agent mining emerges as a new area in the scientific family, (2) both agent technology and data mining can greatly benefit from agent mining, (3) it is very promising to result in additional advancement in intelligent information processing and systems. However, as a new open area, there are many issues waiting for research and development from theoretical, technological and practical perspectives.

Detecting agency from the biological motion of veridical vs animated agents

PubMed Central

Kelley, William M.; Heatherton, Todd F.; Macrae, C. Neil

2007-01-01

The ability to detect agency is fundamental for understanding the social world. Underlying this capacity are neural circuits that respond to patterns of intentional biological motion in the superior temporal sulcus and temporoparietal junction. Here we show that the brain's blood oxygenation level dependent (BOLD) response to such motion is modulated by the representation of the actor. Dynamic social interactions were portrayed by either live-action agents or computer-animated agents, enacting the exact same patterns of biological motion. Using an event-related design, we found that the BOLD response associated with the perception and interpretation of agency was greater when identical physical movements were performed by real rather than animated agents. This finding has important implications for previous work on biological motion that has relied upon computer-animated stimuli and demonstrates that the neural substrates of social perception are finely tuned toward real-world agents. In addition, the response in lateral temporal areas was observed in the absence of instructions to make mental inferences, thus demonstrating the spontaneous implementation of the intentional stance. PMID:18985141

The Design of Collectives of Agents to Control Non-Markovian Systems

NASA Technical Reports Server (NTRS)

Lawson, John W.; Wolpert, David H.

2004-01-01

The Collective Intelligence (COIN) framework concerns the design of collectives of reinforcement-learning agents such that their interaction causes a provided "world" utility function concerning the entire collective to be maximized. Previously, we applied that framework to scenarios involving Markovian dynamics where no re-evolution of the system from counter-factual initial conditions (an often expensive calculation) is permitted. This approach sets the individual utility function of each agent to be both aligned with the world utility, and at the same time, easy for the associated agents to optimize. Here we extend that approach to systems involving non-Markovian dynamics. In computer simulations, we compare our techniques with each other and with conventional "team games". We show whereas in team games performance often degrades badly with time, it steadily improves when our techniques are used. We also investigate situations where the system's dimensionality is effectively reduced. We show that this leads to difficulties in the agents ability to learn. The implication is that learning is a property only of high-enough dimensional systems.

The Design of Collectives of Agents to Control Non-Markovian Systems

NASA Technical Reports Server (NTRS)

Lawson, John W.; Wolpert, David H.; Clancy, Daniel (Technical Monitor)

2002-01-01

The 'Collective Intelligence' (COIN) framework concerns the design of collectives of reinforcement-learning agents such that their interaction causes a provided 'world' utility function concerning the entire collective to be maximized. Previously, we applied that framework to scenarios involving Markovian dynamics where no re-evolution of the system from counter-factual initial conditions (an often expensive calculation) is permitted. This approach sets the individual utility function of each agent to be both aligned with the world utility, and at the same time, easy for the associated agents to optimize. Here we extend that approach to systems involving non-Markovian dynamics. In computer simulations, we compare our techniques with each other and with conventional-'team games'. We show whereas in team games performance often degrades badly with time, it steadily improves when our techniques are used. We also investigate situations where the system's dimensionality is effectively reduced. We show that this leads to difficulties in the agents' ability to learn. The implication is that 'learning' is a property only of high-enough dimensional systems.

Effective Teaching and Learning Environments and Principal Self-Efficacy in Oklahoma: Replication of a Previous Study

ERIC Educational Resources Information Center

Berry, Kathryn

2013-01-01

The purpose of this study was to replicate a previous study by Smith et al. (2006) that explored principal self-efficacy beliefs for facilitating effective instructional environments at their schools. There has been limited research conducted on principal's self-efficacy, and the studies that have been completed on the topic have not been…

Evaluation of an experimental rat model for comparative studies of bleaching agents.

PubMed

Cintra, Luciano Tavares Angelo; Benetti, Francine; Ferreira, Luciana Louzada; Rahal, Vanessa; Ervolino, Edilson; Jacinto, Rogério de Castilho; Gomes Filho, João Eduardo; Briso, André Luiz Fraga

2016-04-01

Dental materials in general are tested in different animal models prior to the clinical use in humans, except for bleaching agents. Objectives To evaluate an experimental rat model for comparative studies of bleaching agents, by investigating the influence of different concentrations and application times of H2O2 gel in the pulp tissue during in-office bleaching of rats' vital teeth. Material and Methods The right and left maxillary molars of 50 Wistar rats were bleached with 20% and 35% H2O2 gels, respectively, for 5, 10, 15, 30, or 45 min (n=10 rats/group). Ten animals were untreated (control). The rats were killed after 2 or 30 days, and the maxillae were examined by light microscopy. Inflammation was evaluated through histomorphometric analysis with inflammatory cell count in the coronal and radicular thirds of the pulp. Fibroblasts were also counted. Scores were attributed to odontoblastic layer and vascular changes. Tertiary dentin area and pulp chamber central area were measured histomorphometrically. Data were compared by analysis of variance and Kruskal-Wallis test (p<0.05). Results After 2 days, the amount of inflammatory cells increased in the coronal pulp occlusal third up to the 15-min application groups of each bleaching gel. In the groups exposed to each concentration for 30 and 45 min, the number of inflammatory cells decreased along with the appearance of necrotic areas. After 30 days, reduction on the pulp chamber central area and enlargement of the tertiary dentin area were observed, without the detection of inflammation areas. Conclusion The rat model of extracoronal bleaching showed to be adequate for studies of bleaching protocols, as it was possible to observe alterations in the pulp tissues and tooth structure caused by different concentrations and application periods of bleaching agents.

Evaluation of an experimental rat model for comparative studies of bleaching agents

PubMed Central

Cintra, Luciano Tavares Angelo; Benetti, Francine; Ferreira, Luciana Lousada; Rahal, Vanessa; Ervolino, Edilson; Jacinto, Rogério de Castilho; Gomes, João Eduardo; Briso, André Luiz Fraga

2016-01-01

ABSTRACT Dental materials, in general, are tested in different animal models prior to their clinical use in humans, except for bleaching agents. Objectives To evaluate an experimental rat model for comparative studies of bleaching agents by investigating the influence of different concentrations and application times of H2O2 gel in the pulp tissue during in-office bleaching of rats’ vital teeth. Material and methods The right and left maxillary molars of 50 Wistar rats were bleached with 20% and 35% H2O2 gels, respectively, for 5, 10, 15, 30, or 45 min (n=10 rats/group). Ten animals (control) were untreated. The rats were killed after 2 or 30 days, and the maxillae were examined by light microscopy. Inflammation was evaluated by histomorphometric analysis with inflammatory cell counting in the coronal and radicular thirds of the pulp. The counting of fibroblasts was also performed. Scores were attributed to the odontoblastic layer and to vascular changes. The tertiary dentin area and the pulp chamber central area were histomorphometrically measured. Data were compared by the analysis of variance and the Kruskal-Wallis test (p<0.05). Results After 2 days, the amount of inflammatory cells increased in the occlusal third of the coronal pulp until the time of 15 min for both concentrations of bleaching gels. In 30 and 45 min groups of each concentration, the number of inflammatory cells decreased along with the appearance of necrotic areas. After 30 days, a reduction in the pulp chamber central area and an enlargement of tertiary dentin area were observed without the detection of inflammation areas. Conclusion The rat model of extra coronal bleaching showed to be adequate for bleaching protocols studies, as it was possible to observe alterations in the pulp tissues and in the tooth structure caused by different concentrations and periods of application of bleaching agents. PMID:27008262

Evaluation of an experimental rat model for comparative studies of bleaching agents

PubMed Central

CINTRA, Luciano Tavares Angelo; BENETTI, Francine; FERREIRA, Luciana Louzada; RAHAL, Vanessa; ERVOLINO, Edilson; JACINTO, Rogério de Castilho; GOMES, João Eduardo; BRISO, André Luiz Fraga

2016-01-01

ABSTRACT Dental materials in general are tested in different animal models prior to the clinical use in humans, except for bleaching agents. Objectives To evaluate an experimental rat model for comparative studies of bleaching agents, by investigating the influence of different concentrations and application times of H2O2 gel in the pulp tissue during in-office bleaching of rats’ vital teeth. Material and Methods The right and left maxillary molars of 50 Wistar rats were bleached with 20% and 35% H2O2 gels, respectively, for 5, 10, 15, 30, or 45 min (n=10 rats/group). Ten animals were untreated (control). The rats were killed after 2 or 30 days, and the maxillae were examined by light microscopy. Inflammation was evaluated through histomorphometric analysis with inflammatory cell count in the coronal and radicular thirds of the pulp. Fibroblasts were also counted. Scores were attributed to odontoblastic layer and vascular changes. Tertiary dentin area and pulp chamber central area were measured histomorphometrically. Data were compared by analysis of variance and Kruskal-Wallis test (p<0.05). Results After 2 days, the amount of inflammatory cells increased in the coronal pulp occlusal third up to the 15-min application groups of each bleaching gel. In the groups exposed to each concentration for 30 and 45 min, the number of inflammatory cells decreased along with the appearance of necrotic areas. After 30 days, reduction on the pulp chamber central area and enlargement of the tertiary dentin area were observed, without the detection of inflammation areas. Conclusion The rat model of extracoronal bleaching showed to be adequate for studies of bleaching protocols, as it was possible to observe alterations in the pulp tissues and tooth structure caused by different concentrations and application periods of bleaching agents. PMID:27119766

Evaluation of an experimental rat model for comparative studies of bleaching agents.

PubMed

Cintra, Luciano Tavares Angelo; Benetti, Francine; Ferreira, Luciana Lousada; Rahal, Vanessa; Ervolino, Edilson; Jacinto, Rogério de Castilho; Gomes Filho, João Eduardo; Briso, André Luiz Fraga

2016-01-01

Dental materials, in general, are tested in different animal models prior to their clinical use in humans, except for bleaching agents. To evaluate an experimental rat model for comparative studies of bleaching agents by investigating the influence of different concentrations and application times of H2O2 gel in the pulp tissue during in-office bleaching of rats' vital teeth. The right and left maxillary molars of 50 Wistar rats were bleached with 20% and 35% H2O2 gels, respectively, for 5, 10, 15, 30, or 45 min (n=10 rats/group). Ten animals (control) were untreated. The rats were killed after 2 or 30 days, and the maxillae were examined by light microscopy. Inflammation was evaluated by histomorphometric analysis with inflammatory cell counting in the coronal and radicular thirds of the pulp. The counting of fibroblasts was also performed. Scores were attributed to the odontoblastic layer and to vascular changes. The tertiary dentin area and the pulp chamber central area were histomorphometrically measured. Data were compared by the analysis of variance and the Kruskal-Wallis test (p<0.05). After 2 days, the amount of inflammatory cells increased in the occlusal third of the coronal pulp until the time of 15 min for both concentrations of bleaching gels. In 30 and 45 min groups of each concentration, the number of inflammatory cells decreased along with the appearance of necrotic areas. After 30 days, a reduction in the pulp chamber central area and an enlargement of tertiary dentin area were observed without the detection of inflammation areas. The rat model of extra coronal bleaching showed to be adequate for bleaching protocols studies, as it was possible to observe alterations in the pulp tissues and in the tooth structure caused by different concentrations and periods of application of bleaching agents.

Integrated multimedia medical data agent in E-health.

PubMed

di Giacomo, P; Ricci, Fabrizio L; Bocchi, Leonardo

2006-01-01

E-Health is producing a great impact in the field of information distribution of the health services to the intra-hospital and the public. Previous researches have addressed the development of system architectures in the aim of integrating the distributed and heterogeneous medical information systems. The easing of difficulties in the sharing and management of medical data and the timely accessibility to these data is a critical need for health care providers. We have proposed a client-server agent that allows a portal to the every permitted Information System of the Hospital that consists of PACS, RIS and HIS via the Intranet and the Internet. Our proposed agent enables remote access into the usually closed information system of the hospital and a server that indexes all the medical data which allows for in-depth and complex search queries for data retrieval.

Diarrheal diseases of infancy in Cali, Colombia: study design and summary report on isolated disease agents.

PubMed

Newell, K W; Dover, A S; Clemmer, D I; D'Alessandro, A; Duenas, A; Gracián, M; LeBlanc, D R

1976-01-01

For public health reasons, it is important that the etiologic agents of early childhood diarrhea be isolated and identified, and that their routes of transmission be defined. This is especially true in tropical and subtropical developing countries, where childhood patterns of exposure to diarrheal disease agents usually differ from those in developed countries, and where diarrheal illness is a frequent harbinger of death among children under five years of age. This artical describes a study designed to identify diarrheal disease agents and transmission patterns in Cali, a large city of western Colombia's fertile Cauca River Valley. The study area, composed of five working-class districts with a total population of some 40,000, appeared to provide an environment fairly similar to those of many other "average" working-class communities in Latin America. Beginning in July 1962, a cohort of 296 children being born in these districts was studied, the period of investigation starting with the date of birth and continuing until each child's second birthday or its premature withdrawal from the study. Weekly home visits were made to establish defecation patterns, feeding practices, and anthropometry. The resulting data were then analyzed in terms of defecation frequencies, occurrence of liquid stools, and the presence of blood, mucus, or pus in the stools. Differences were noted in male and female defecation patterns and in the defecation frequencies of different age groups. Stool specimens for bacteriologic, virologic, and parasitologic examination were collected monthly on a regular basis and weekly when diarrhea occurred. Numerically, viruses were isolated and identified more often than other agents. The most commonly isolated parasite species and viral and bacterial serotypes were G. lamblia (from 222 subjects), echovirus 11 (from 166 subjects), and enteropathogenic Escherichia coli 026:B6 (from 138 subjects). Compared with the findings of several studies in other

Hemostatic Agents in Periapical Surgery: A Randomized Study of Gauze Impregnated in Epinephrine versus Aluminum Chloride.

PubMed

Menéndez-Nieto, Isabel; Cervera-Ballester, Juan; Maestre-Ferrín, Laura; Blaya-Tárraga, Juan Antonio; Peñarrocha-Oltra, David; Peñarrocha-Diago, Miguel

2016-11-01

Adequate bleeding control is essential for the success of periapical surgery. The aim of this study was to evaluate the effects of 2 hemostatic agents on the outcome of periapical surgery and their relationship with patient and teeth parameters. A prospective study was designed with 2 randomized parallel groups, depending on the hemostatic agent used: gauze impregnated in epinephrine (epinephrine group) and aluminum chloride (aluminum chloride group). The analysis of the hemorrhage control was judged before and after the application of the hemostatic agents by the surgeon, and 2 examiners independently recorded it as adequate (complete hemorrhage control) or inadequate (incomplete hemorrhage control). Ninety-nine patients with a periradicular lesion were enrolled in this study and divided into 2 groups: gauze impregnated in epinephrine in 48 patients (epinephrine group) or aluminum chloride in 51 (aluminum chloride group). In epinephrine group adequate hemostasis was achieved in 25 cases, and in aluminum chloride group it was achieved in 37 cases (P < .05). The outcome was better in the aluminum chloride group than in the gauze impregnated in epinephrine group. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Adenosine triphosphate-sensitive potassium channel blocking agent ameliorates, but the opening agent aggravates, ischemia/reperfusion-induced injury. Heart function studies in nonfibrillating isolated hearts.

PubMed

Tosaki, A; Hellegouarch, A

1994-02-01

This study was conducted to elucidate the role of the adenosine triphosphate (ATP)-sensitive potassium channel blocking agent glibenclamide and the opener cromakalim in the mechanism of reperfusion-induced injury. Recently, ATP-sensitive potassium channel openers have been proposed to reduce ischemia/reperfusion-induced injury, including arrhythmias and heart function. Thus, one might hypothesize that pharmacologic agents that enhance the loss of potassium ions in the myocardium through ATP-sensitive potassium channels would be arrhythmogenic, and agents that interfere with tissue potassium ion loss would be antiarrhythmic. Isolated "working" guinea pig hearts and phosphorus-31 nuclear magnetic resonance spectroscopy were used to study the recovery of myocardial function and phosphorus compounds after 30, 40 and 50 min of normothermic global ischemia followed by reperfusion in untreated control and glibenclamide- and cromakalim-treated groups. After 30 min of ischemia, 1, 3, 10 and 30 mumol/liter of glibenclamide dose-dependently reduced the incidence of reperfusion-induced ventricular fibrillation (total) from its control value of 92% to 75%, 33% (p < 0.05), 33% (p < 0.05) and 42% (p < 0.05), respectively. The incidence of ventricular tachycardia followed the same pattern. A reduction of arrhythmias was also observed after 40 and 50 min of ischemia followed by reperfusion in the glibenclamide-treated hearts. Cromakalim, at the same concentrations, did not reduce the incidence of reperfusion-induced arrhythmias. During reperfusion, glibenclamide (3 and 10 mumol/liter) improved the recovery of coronary blood flow, aortic flow, myocardial contractility and tissue ATP and creatine phosphate content, but cromakalim failed to ameliorate the recovery of postischemic myocardium compared with that in the drug-free control hearts. The preservation of myocardial potassium ions and phosphorus compounds by glibenclamide can improve the recovery of postischemic function, but

Dogs (Canis familiaris) adjust their social behaviour to the differential role of inanimate interactive agents.

PubMed

Petró, Eszter; Abdai, Judit; Gergely, Anna; Topál, József; Miklósi, Ádám

2016-03-01

Dogs are able to flexibly adjust their social behaviour to situation-specific characteristics of their human partner's behaviour in problem situations. However, dogs do not necessarily detect the specific role played by the human in a particular situation: they may form expectations about their partners' behaviour based on previous experiences with them. Utilising inanimate objects (UMO-unidentified moving object) as interacting agents offers new possibilities for investigating social behaviour, because in this way we can remove or control the influence of previous experience with the partner. The aim of the present study was to investigate whether dogs are able to recognise the different roles of two UMOs and are able to adjust their communicative behaviour towards them. In the learning phase of the experiment, dogs were presented with a two-way food-retrieval problem in which two UMOs, which differed in their physical appearance and abilities, helped the dog obtain a piece of food in their own particular manner. After a short experience with both UMOs, dogs in the test phase faced one of the problems in the presence of both inanimate agents. Overall, dogs displayed similar levels of gazing behaviour towards the UMOs, but in the first test they looked, approached and touched the relevant partner first. This rapid adjustment of social behaviour towards UMOs suggests that dogs may generalise their experiences with humans to unfamiliar agents and are able to select the appropriate partner when facing a problem situation.

Joint Chemical Agent Detector (JCAD): the future of chemical agent detection

NASA Astrophysics Data System (ADS)

Laljer, Charles E.; Owen, Jeffery L.

2002-06-01

The Joint Chemical Agent Detector (JCAD) will provide state of the art chemical warfare agent detection capability to ground vehicle operators. Intelligence sources estimate that over twenty counties have active chemical weapons programs. The spread of chemical weapons to third world nations, coupled with the potential for US involvement in these areas in an operational or support capacity, increases the probability that the Joint Services may encounter chemical agents and toxic industrial materials anywhere in the world. Currently, fielded chemical agent detectors are bulky, labor intensive, and subject to false readings. No legacy detector is sensitive enough to provide detection and warning of the low dose hazards associated with miosis contamination. The JCAD will provide a small, lightweight chemical agent detector for vehicle interiors, aircraft, individual personnel, shipboard, and fixed site locations. The system provides a common detection components across multi-service platforms. This common detector system will allow the Joint Services to use the same operational and support concept for more efficient utilization of resources. The JCAD will detect, identify, quantify, and warn of the presence of chemical agents prior to onset of miosis. Upon detection of chemical agents, the detector will provide local and remote audible and visual alarms to the operators. Advance warning will provide the vehicle crew with the time necessary to protect themselves from the lethal effects of chemical agents. The JCAD will also be capable of being upgraded to protect against future chemical agent threats. The JCAD will provide the vehicle operators with the warning necessary to survive and fight in a chemical warfare agent threat environment.

Joint chemical agent detector (JCAD): the future of chemical agent detection

NASA Astrophysics Data System (ADS)

Laljer, Charles E.

2003-08-01

The Joint Chemical Agent Detector (JCAD) has continued development through 2002. The JCAD has completed Contractor Validation Testing (CVT) that included chemical warfare agent testing, environmental testing, electromagnetic interferent testing, and platform integration validation. The JCAD provides state of the art chemical warfare agent detection capability to military and homeland security operators. Intelligence sources estimate that over twenty countries have active chemical weapons programs. The spread of weapons of mass destruction (and the industrial capability for manufacture of these weapons) to third world nations and terrorist organizations has greatly increased the chemical agent threat to U.S. interests. Coupled with the potential for U.S. involvement in localized conflicts in an operational or support capacity, increases the probability that the military Joint Services may encounter chemical agents anywhere in the world. The JCAD is a small (45 in3), lightweight (2 lb.) chemical agent detector for vehicle interiors, aircraft, individual personnel, shipboard, and fixed site locations. The system provides a common detection component across multi-service platforms. This common detector system will allow the Joint Services to use the same operational and support concept for more efficient utilization of resources. The JCAD detects, identifies, quantifies, and warns of the presence of chemical agents prior to onset of miosis. Upon detection of chemical agents, the detector provides local and remote audible and visual alarms to the operators. Advance warning will provide the vehicle crew and other personnel in the local area with the time necessary to protect themselves from the lethal effects of chemical agents. The JCAD is capable of being upgraded to protect against future chemical agent threats. The JCAD provides the operator with the warning necessary to survive and fight in a chemical warfare agent threat environment.

Pasteurella aerogenes as an Asymptomatic Bacteriuria Agent.

PubMed

Alaygut, Demet; Engin, Aynur

2018-02-01

'Asymptomatic bacteriuria' (ASB) is isolation of a specified quantitative count of bacteria in an appropriately collected urine specimen obtained from a person without symptoms or signs referable to urinary infection. Catheterized specimens are less likely to be contaminated compared with voided specimens; therefore, positive cultures of catheterized specimens are more likely to reflect true bladder bacteriuria even with low colony counts. The common pathogens for ASB are Escherichia coli, Klebsiella and Streptococcus spp. Pasteurella spp. was not previously reported as an ASB agent. ASB is important for pregnant women, children, individuals with obstructive uropathy, chronic renal failure and neutropenia, before the urologic procedures and after renal transplantation. Treatment of ASB is required for above situations. We report an 11-year-old-girl with neurogenic bladder who made clean intermittent catheterization and had Pasteurella aerogenes as an ASB agent. © The Author [2017]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The highly intelligent virtual agents for modeling financial markets

NASA Astrophysics Data System (ADS)

Yang, G.; Chen, Y.; Huang, J. P.

2016-02-01

Researchers have borrowed many theories from statistical physics, like ensemble, Ising model, etc., to study complex adaptive systems through agent-based modeling. However, one fundamental difference between entities (such as spins) in physics and micro-units in complex adaptive systems is that the latter are usually with high intelligence, such as investors in financial markets. Although highly intelligent virtual agents are essential for agent-based modeling to play a full role in the study of complex adaptive systems, how to create such agents is still an open question. Hence, we propose three principles for designing high artificial intelligence in financial markets and then build a specific class of agents called iAgents based on these three principles. Finally, we evaluate the intelligence of iAgents through virtual index trading in two different stock markets. For comparison, we also include three other types of agents in this contest, namely, random traders, agents from the wealth game (modified on the famous minority game), and agents from an upgraded wealth game. As a result, iAgents perform the best, which gives a well support for the three principles. This work offers a general framework for the further development of agent-based modeling for various kinds of complex adaptive systems.

Sunscreening Agents

PubMed Central

Martis, Jacintha; Shobha, V; Sham Shinde, Rutuja; Bangera, Sudhakar; Krishnankutty, Binny; Bellary, Shantala; Varughese, Sunoj; Rao, Prabhakar; Naveen Kumar, B.R.

2013-01-01

The increasing incidence of skin cancers and photodamaging effects caused by ultraviolet radiation has increased the use of sunscreening agents, which have shown beneficial effects in reducing the symptoms and reoccurrence of these problems. Many sunscreen compounds are in use, but their safety and efficacy are still in question. Efficacy is measured through indices, such as sun protection factor, persistent pigment darkening protection factor, and COLIPA guidelines. The United States Food and Drug Administration and European Union have incorporated changes in their guidelines to help consumers select products based on their sun protection factor and protection against ultraviolet radiation, whereas the Indian regulatory agency has not yet issued any special guidance on sunscreening agents, as they are classified under cosmetics. In this article, the authors discuss the pharmacological actions of sunscreening agents as well as the available formulations, their benefits, possible health hazards, safety, challenges, and proper application technique. New technologies and scope for the development of sunscreening agents are also discussed as well as the role of the physician in patient education about the use of these agents. PMID:23320122

Embodied artificial agents for understanding human social cognition.

PubMed

Wykowska, Agnieszka; Chaminade, Thierry; Cheng, Gordon

2016-05-05

In this paper, we propose that experimental protocols involving artificial agents, in particular the embodied humanoid robots, provide insightful information regarding social cognitive mechanisms in the human brain. Using artificial agents allows for manipulation and control of various parameters of behaviour, appearance and expressiveness in one of the interaction partners (the artificial agent), and for examining effect of these parameters on the other interaction partner (the human). At the same time, using artificial agents means introducing the presence of artificial, yet human-like, systems into the human social sphere. This allows for testing in a controlled, but ecologically valid, manner human fundamental mechanisms of social cognition both at the behavioural and at the neural level. This paper will review existing literature that reports studies in which artificial embodied agents have been used to study social cognition and will address the question of whether various mechanisms of social cognition (ranging from lower- to higher-order cognitive processes) are evoked by artificial agents to the same extent as by natural agents, humans in particular. Increasing the understanding of how behavioural and neural mechanisms of social cognition respond to artificial anthropomorphic agents provides empirical answers to the conundrum 'What is a social agent?' © 2016 The Authors.

Agent neutralization studies III. Detoxification of VX in aqueous persulfate. Final report, May-August 1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hovanec, J.W.; Albizo, J.M.; Henderson, V.D.

1994-06-01

Aqueous solutions of persulfate salts are frequently used to mineralize organic substrates in the course of total organic carbon analyses. A study has been conducted at the U.S. Army Edgewood Research, Development and Engineering Center to determine whether this approach may be useful to neutralize the nerve agent VX. VX was reacted with aqueous ammonium persulfate at 90 deg C and 70 deg C. The concentration of agent and the acidity of the mixture were varied. 31P-NMR was used to monitor the destruction of VX as well as the formation and degradation of the phosphorus-containing products. A titration procedure usingmore » ferrous sulfate and ceric ammonium nitrate was used to monitor the consumption of persulfate. The products formed and their stabilities were found to vary significantly with the acidity of the solution. Nuclear magnetic resonance, Oxidation, VX, Ammonium persulfate, Mineralization, Temperature effects, Chemical agent disposal.« less

Occupation, exposure to chemicals, sensitizing agents, and risk of multiple myeloma in Sweden.

PubMed

Lope, Virginia; Pérez-Gómez, Beatriz; Aragonés, Nuria; López-Abente, Gonzalo; Gustavsson, Per; Plato, Nils; Zock, Jan-Paul; Pollán, Marina

2008-11-01

This study sought to identify occupations with high incidence of multiple myeloma and to investigate possible excess risk associated with occupational exposure to chemicals and sensitizing agents in Sweden. A historical cohort of 2,992,166 workers was followed up (1971--1989) through record linkage with the National Cancer and Death Registries. For each job category, age and period standardized incidence ratios and age and period adjusted relative risks of multiple myeloma were calculated using Poisson models. Exposure to chemicals and to sensitizing agents was also assessed using two job-exposure matrices. Men and women were analyzed separately. During follow-up, 3,127 and 1,282 myelomas were diagnosed in men and women, respectively. In men, excess risk was detected among working proprietors, agricultural, horticultural and forestry enterprisers, bakers and pastry cooks, dental technicians, stone cutters/carvers, and prison/reformatory officials. In women, this excess was observed among attendants in psychiatric care, metal workers, bakers and pastry cooks, and paper/paperboard product workers. Workers, particularly bakers and pastry cooks, exposed to high molecular weight sensitizing agents registered an excess risk of over 40% across the sexes. Occasional, although intense, exposure to pesticides was also associated with risk of myeloma in our cohort. Our study supports a possible etiologic role for farming and use of pesticides in myeloma risk. The high incidence found in both female and male bakers and pastry cooks has not been described previously. Further research is required to assess the influence of high molecular weight sensitizing agents on risk of multiple myeloma.

Younger and Older Users’ Recognition of Virtual Agent Facial Expressions

PubMed Central

Beer, Jenay M.; Smarr, Cory-Ann; Fisk, Arthur D.; Rogers, Wendy A.

2015-01-01

As technology advances, robots and virtual agents will be introduced into the home and healthcare settings to assist individuals, both young and old, with everyday living tasks. Understanding how users recognize an agent’s social cues is therefore imperative, especially in social interactions. Facial expression, in particular, is one of the most common non-verbal cues used to display and communicate emotion in on-screen agents (Cassell, Sullivan, Prevost, & Churchill, 2000). Age is important to consider because age-related differences in emotion recognition of human facial expression have been supported (Ruffman et al., 2008), with older adults showing a deficit for recognition of negative facial expressions. Previous work has shown that younger adults can effectively recognize facial emotions displayed by agents (Bartneck & Reichenbach, 2005; Courgeon et al. 2009; 2011; Breazeal, 2003); however, little research has compared in-depth younger and older adults’ ability to label a virtual agent’s facial emotions, an import consideration because social agents will be required to interact with users of varying ages. If such age-related differences exist for recognition of virtual agent facial expressions, we aim to understand if those age-related differences are influenced by the intensity of the emotion, dynamic formation of emotion (i.e., a neutral expression developing into an expression of emotion through motion), or the type of virtual character differing by human-likeness. Study 1 investigated the relationship between age-related differences, the implication of dynamic formation of emotion, and the role of emotion intensity in emotion recognition of the facial expressions of a virtual agent (iCat). Study 2 examined age-related differences in recognition expressed by three types of virtual characters differing by human-likeness (non-humanoid iCat, synthetic human, and human). Study 2 also investigated the role of configural and featural processing as a

A functional form for injected MRI Gd-chelate contrast agent concentration incorporating recirculation, extravasation and excretion

NASA Astrophysics Data System (ADS)

Horsfield, Mark A.; Thornton, John S.; Gill, Andrew; Jager, H. Rolf; Priest, Andrew N.; Morgan, Bruno

2009-05-01

A functional form for the vascular concentration of MRI contrast agent after intravenous bolus injection was developed that can be used to model the concentration at any vascular site at which contrast concentration can be measured. The form is based on previous models of blood circulation, and is consistent with previously measured data at long post-injection times, when the contrast agent is fully and evenly dispersed in the blood. It allows the first-pass and recirculation peaks of contrast agent to be modelled, and measurement of the absolute concentration of contrast agent at a single time point allows the whole time course to be rescaled to give absolute contrast agent concentration values. This measure of absolute concentration could be performed at a long post-injection time using either MRI or blood-sampling methods. In order to provide a model that is consistent with measured data, it was necessary to include both rapid and slow extravasation, together with excretion via the kidneys. The model was tested on T1-weighted data from the descending aorta and hepatic portal vein, and on T*2-weighted data from the cerebral arteries. Fitting of the model was successful for all datasets, but there was a considerable variation in fit parameters between subjects, which suggests that the formation of a meaningful population-averaged vascular concentration function is precluded.

Social Dynamics in Web Page through Inter-Agent Interaction

NASA Astrophysics Data System (ADS)

Takeuchi, Yugo; Katagiri, Yasuhiro

Social persuasion abounds in human-human interactions. Attitudes and behaviors of people are invariably influenced by the attitudes and behaviors of other people as well as our social roles/relationships toward them. In the pedagogic scene, the relationship between teacher and learner produces one of the most typical interactions, in which the teacher makes the learner spontaneously study what he/she teaches. This study is an attempt to elucidate the nature and effectiveness of social persuasion in human-computer interaction environments. We focus on the social dynamics of multi-party interactions that involve both human-agent and inter-agent interactions. An experiment is conducted in a virtual web-instruction setting employing two types of agents: conductor agents who accompany and guide each learner throughout his/her learning sessions, and domain-expert agents who provide explanations and instructions for each stage of the instructional materials. In this experiment, subjects are assigned two experimental conditions: the authorized condition, in which an agent respectfully interacts with another agent, and the non-authorized condition, in which an agent carelessly interacts with another agent. The results indicate performance improvements in the authorized condition of inter-agent interactions. An analysis is given from the perspective of the transfer of authority from inter-agent to human-agent interactions based on social conformity. We argue for pedagogic advantages of social dynamics created by multiple animated character agents.

Synthesis and mechanistic studies of curcumin analog-based oximes as potential anticancer agents.

PubMed

Qin, Hua-Li; Leng, Jing; Youssif, Bahaa G M; Amjad, Muhammad Wahab; Raja, Maria Abdul Ghafoor; Hussain, Muhammad Ajaz; Hussain, Zahid; Kazmi, Syeda Naveed; Bukhari, Syed Nasir Abbas

2017-09-01

The incidence of cancer can be decreased by chemoprevention using either natural or synthetic agents. Apart from synthetic compounds, numerous natural products have exhibited promising potential to inhibit carcinogenesis in vivo. In this study, α, β-unsaturated carbonyl-based anticancer compounds were used as starting materials to synthesize new oxime analogs. The findings from the antiproliferative assay using seven different human cancer cell lines provided a clear picture of structure-activity relationship. The oxime analogs namely 7a and 8a showed strong antiproliferative activity against the cell lines. The mechanistic effects of compounds on EGFR-TK kinases and tubulin polymerization and BRAF V 600E were investigated. In addition, the efficacy of compounds in reversing the efflux-mediated resistance developed by cancer cells was also studied. The compounds 5a and 6a displayed potent activity on various targets such as BRAF V 600E and EGFR-TK kinases and also exhibited strong antiproliferative activity against different cell lines hence showing potential of multifunctional anticancer agents. © 2017 John Wiley & Sons A/S.

Who is more efficient: Teacher or pedagogical agents?

NASA Astrophysics Data System (ADS)

Lee, Tien Tien; Mustapha, Nur Hanani

2017-05-01

The purpose of the study is to investigate the impact of pedagogical agent's and teacher's role on students' understanding and motivation in the learning of Electrochemistry. Interactive Multimedia Module with Pedagogical Agents, EC Lab (IMMPA EC Lab) was used in this study. IMMPA EC Lab consists of five subunits in Electrochemistry topic. The research was a non-equivalent control group quasi experimental design involving two treatment groups and one control group. The first treatment group studied Electrochemistry with expert agent (Professor T) while the second treatment group studied Electrochemistry with learning companion agent (Lisa). On the other hand, the control group learned Electrochemistry with their Chemistry teacher using the material in the IMMPA EC Lab. The study was conducted at a secondary science school in the Pasir Puteh district involving 74 form four students. The instruments used in this research were the Electrochemistry achievement tests in the form of pre-test and post-test, IMMPA EC Lab and motivation questionnaire. ANCOVA results found that there was no significant difference among the three groups in post-test. On the other hand, One-way ANOVA test proved that there were significant differences for the post-motivation scores between the control group and the treatment groups. Post motivation mean scores for expert agent treatment group and learning companion treatment group surpassed the control group. The study focus on the impact of pedagogical agents with different roles on students' learning and motivation should be promoted. Various versions of pedagogical agents that fulfil the good characteristics should be designed to enhance students' learning and motivation.

A study on expertise of agents and its effects on cooperative Q-learning.

PubMed

Araabi, Babak Nadjar; Mastoureshgh, Sahar; Ahmadabadi, Majid Nili

2007-04-01

Cooperation in learning (CL) can be realized in a multiagent system, if agents are capable of learning from both their own experiments and other agents' knowledge and expertise. Extra resources are exploited into higher efficiency and faster learning in CL as compared to that of individual learning (IL). In the real world, however, implementation of CL is not a straightforward task, in part due to possible differences in area of expertise (AOE). In this paper, reinforcement-learning homogenous agents are considered in an environment with multiple goals or tasks. As a result, they become expert in different domains with different amounts of expertness. Each agent uses a one-step Q-learning algorithm and is capable of exchanging its Q-table with those of its teammates. Two crucial questions are addressed in this paper: "How the AOE of an agent can be extracted?" and "How agents can improve their performance in CL by knowing their AOEs?" An algorithm is developed to extract the AOE based on state transitions as a gold standard from a behavioral point of view. Moreover, it is discussed that the AOE can be implicitly obtained through agents' expertness in the state level. Three new methods for CL through the combination of Q-tables are developed and examined for overall performance after CL. The performances of developed methods are compared with that of IL, strategy sharing (SS), and weighted SS (WSS). Obtained results show the superior performance of AOE-based methods as compared to that of existing CL methods, which do not use the notion of AOE. These results are very encouraging in support of the idea that "cooperation based on the AOE" performs better than the general CL methods.

Experimental Study of Ultrasound Contrast Agent Mediated Heat Transfer for Therapeutic Applications

NASA Astrophysics Data System (ADS)

Razansky, D.; Adam, D. R.; Einziger, P. D.

2006-05-01

Ultrasound Contrast Agents (UCA) have been recently suggested as efficient enhancers of ultrasonic power deposition in tissue. The ultrasonic energy absorption by UCA, considered as disadvantageous in diagnostic imaging, might be valuable in therapeutic applications such as targeted hyperthermia or ablation treatments. The current study, based on theoretical predictions, was designed to experimentally measure the dissipation and heating effects of encapsulated UCA (Optison™) in a well-controlled and calibrated environment.

The time course of indirect moral judgment in gossip processing modulated by different agents.

PubMed

Peng, Xiaozhe; Jiao, Can; Cui, Fang; Chen, Qingfei; Li, Peng; Li, Hong

2017-10-01

Previous studies have investigated personal moral violations with different references (i.e., the protagonists in moral scenarios are the participants themselves or unknown other individuals). However, the roles of various agents in moral judgments have remained unclear. In the present study, ERPs were used to investigate moral judgments when the participants viewed gossip that described (im)moral behaviors committed by different agents (self, friend, celebrity). The results demonstrate that the P2 and late positive component (LPC) correspond to two successive processes of indirect moral judgment when individuals process gossip. Specifically, the P2 amplitude in the celebrity condition was more sensitive in distinguishing immoral behaviors from moral behaviors than that in the other two conditions, whereas the moral valence effect on the LPC was predominately driven by the self-reference. These findings expand our current understanding of moral judgments in a gossip evaluation task and demonstrate that the early processing of gossip depends on both the entertainment value of the agent and the salience of moral behaviors. Processing in the later stage reflects reactions to intensified affective stimuli, or reflects cognitive effort that was required to resolve the conflict between negative gossip about self and the self-positivity bias. © 2017 Society for Psychophysiological Research.

[Infective fungal endocarditis in patients with no previous cardiac disease].

PubMed

Marcano Sanz, L; Naranjo Ugalde, A; González Guillén, A; Bermúdez Gutiérrez, G; Frías Griskho, F

2013-02-01

Infective endocarditis is a serious and uncommon condition affecting the endocardium. Less than 10% of these cases are of fungal origin. A growing number of individuals are at high risk, due to insertion of central venous catheters, total parenteral nutrition and prolonged exposure to broad-spectrum antibiotics, even without previous heart diseases. We retrospectively analysed the records of six children with Candida endocarditis, reviewing the comorbidities, clinical outcome, and treatment. The antifungal agents used were amphotericin B, 5-fluorocytosine and fluconazole. Patients underwent surgical excision of vegetation, five tricuspid valve repairs and one mitral valve replacement. There were no hospital deaths, and one child needed a new valvuloplasty one year later. The mean follow up was five years, and all have good valvular function without recurrent endocarditis. A combination of synergistic long-term antifungal treatment and early surgical intervention is recommended. Copyright © 2011 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

Co-prescription of gastroprotective agents and their efficacy in elderly patients taking nonsteroidal anti-inflammatory drugs: a systematic review of observational studies.

PubMed

Medlock, Stephanie; Eslami, Saeid; Askari, Marjan; Taherzadeh, Zhila; Opondo, Dedan; de Rooij, Sophia E; Abu-Hanna, Ameen

2013-10-01

Guidelines recommend prescribing gastroprotective agents (proton pump inhibitors, misoprostol) to older patients (primarily ≥65 years old) taking nonsteroidal anti-inflammatory drugs (NSAIDs) to prevent gastrointestinal ulcers. Older individuals are underrepresented in clinical trials of these agents. We systematically reviewed evidence from observational studies on the use of gastroprotective agents in elderly patients and their ability to prevent NSAID-related ulcers in this population. We performed a systematic search of Embase and MEDLINE and identified 23 observational studies that focused on elderly patients and reported data on co-prescription of gastroprotective agents and NSAIDs and/or the effectiveness of the agents in preventing gastrointestinal events in NSAID users. We collected data on rates of co-prescription and NSAID-related gastrointestinal events in patients with and without gastroprotection. A median of 24% (range, 10%-69%) of elderly patients taking NSAIDs received a co-prescription for gastroprotective agents; this percentage was only slightly higher in the oldest age groups. All studies of efficacy showed a positive effect of gastroprotection. However, the adjusted results were not suitable for synthesis, and the 5 studies reporting unadjusted results were too heterogeneous for meta-analysis (I(2) = 97%). The studies differed in outcomes, definitions of co-prescription, and differences in baseline risk factors between patients with and without gastroprotection. None of the studies assessed adverse effects of gastroprotective agents. The 2 cost-effectiveness studies reached opposing conclusions. In a systematic review, the observational evidence for the efficacy of gastroprotective agents in preventing NSAID-associated gastrointestinal events was in agreement with results of randomized controlled trials. However, because of heterogeneity of included studies, it is not clear what the effect would be if more patients were treated, or at what

To what extent have functional studies of ischaemia in animals been useful in the assessment of potential neuroprotective agents?

PubMed

Hunter, A J; Mackay, K B; Rogers, D C

1998-02-01

A general consensus is being reached on the use of a combination of mortality and functional end-points in clinical trials of neuroprotective agents. However, to date, few preclinical studies have examined the effects of putative neuroprotective agents on functional outcome after ischaemia. The data described in this review show the importance of combining both histopathological and neurobehavioural studies when evaluating the neuroprotective efficacy of anti-ischaemic agents in animal models of cerebral ischaemia. Here, Jackie Hunter, Ken Mackay and Derek Rogers argue that measures of functional improvement in models of ischaemia should be incorporated to characterize further the neuroprotection afforded by a compound that could aid the selection of doses and end-point measures in early clinical trials.

Reproductive studies with the anti-inflammatory agent, piroxicam: modification of classical protocols.

PubMed

Perraud, J; Stadler, J; Kessedjian, M J; Monro, A M

1984-02-14

Reproductive toxicology studies were conducted in rabbits and rats given piroxicam, a non-steroidal anti-inflammatory agent (NSAI), orally at 2, 5 and 10 mg/kg/day. In teratology studies there was neither drug-related embryotoxicity nor teratogenicity. As piroxicam, like other NSAI, affects parturition in rats and leads to a progressive toxicity in lactating females, standard protocols were modified: dams of the female fertility study were treated from 2 weeks prior to mating until day 6 of gestation and females of the post-natal toxicity study were treated from parturition until day 12 of lactation. No other adverse effects on reproduction, fertility and postnatal development were observed.

Infections and exposure to anti-infective agents and the risk of severe mental disorders: a nationwide study.

PubMed

Köhler, O; Petersen, L; Mors, O; Mortensen, P B; Yolken, R H; Gasse, C; Benros, M E

2017-02-01

Severe infections are associated with increased risks of mental disorders; however, this is the first large-scale study investigating whether infections treated with anti-infective agents in the primary care setting increase the risks of schizophrenia and affective disorders. We identified all individuals born in Denmark 1985-2002 (N = 1 015 447) and studied the association between infections treated with anti-infective agents and the subsequent risk of schizophrenia and affective disorders during 1995-2013. Cox regression analyses were adjusted for important confounders. Infections treated with anti-infective agents were associated with increased risks of schizophrenia by a hazard rate ratio (HRR) of 1.37 (95%-CI = 1.20-1.57) and affective disorders by a HRR of 1.64 (95%-CI = 1.48-1.82), fitting a dose-response and temporal relationship (P < 0.001). The excess risk was primarily driven by infections treated with antibiotics, whereas infections treated with antivirals, antimycotics, and antiparasitic agents were not significant after mutual adjustment. Individuals with infections requiring hospitalization had the highest risks for schizophrenia (HRR = 2.05; 95%-CI = 1.77-2.38) and affective disorders (HRR = 2.59; 95%-CI = 2.31-2.89). Infections treated with anti-infective agents and particularly infections requiring hospitalizations were associated with increased risks of schizophrenia and affective disorders, which may be mediated by effects of infections/inflammation on the brain, alterations of the microbiome, genetics, or other environmental factors. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Burnout among Extension Agents in the Ohio Cooperative Extension Service.

ERIC Educational Resources Information Center

Igodan, O. Chris; Newcomb, L. H.

A study examined the extent and causes of burnout among extension agents in Ohio. From the 241 extension agents working in the 88 counties of Ohio, researchers selected a random sample of 101 agents. Included in the sample were 34 agriculture agents, 33 home economics agents. Included in the sample agents were asked to complete a survey…

Internet-enabled collaborative agent-based supply chains

NASA Astrophysics Data System (ADS)

Shen, Weiming; Kremer, Rob; Norrie, Douglas H.

2000-12-01

This paper presents some results of our recent research work related to the development of a new Collaborative Agent System Architecture (CASA) and an Infrastructure for Collaborative Agent Systems (ICAS). Initially being proposed as a general architecture for Internet based collaborative agent systems (particularly complex industrial collaborative agent systems), the proposed architecture is very suitable for managing the Internet enabled complex supply chain for a large manufacturing enterprise. The general collaborative agent system architecture with the basic communication and cooperation services, domain independent components, prototypes and mechanisms are described. Benefits of implementing Internet enabled supply chains with the proposed infrastructure are discussed. A case study on Internet enabled supply chain management is presented.

Efficacy and safety of retreatment with nivolumab in metastatic melanoma patients previously treated with nivolumab.

PubMed

Nomura, Motoo; Otsuka, Atsushi; Kondo, Tomohiro; Nagai, Hiroki; Nonomura, Yumi; Kaku, Yo; Matsumoto, Shigemi; Muto, Manabu

2017-11-01

Nivolumab is a monoclonal antibody directed against programmed death-1 that has been shown to improve survival in patients with metastatic melanoma. However, the efficacy of nivolumab and other agents in melanoma remains limited. The objective of this study was to evaluate the efficacy and safety of retreatment with nivolumab in metastatic melanoma patients who previously progressed on nivolumab. A retrospective review was performed on eight consecutive metastatic melanoma patients retreated with nivolumab who progressed on previous nivolumab. These patients received nivolumab 2 mg/kg every 3 weeks. Best responses to each treatment were assessed using RECIST 1.1. Of eight metastatic melanoma patients, three patients received chemotherapy before first nivolumab. The median first nivolumab treatment period was 4.1 months. During first nivolumab, 3 (37.5%) patients achieved a partial response and 3 (37.5%) patients achieved stable disease as their best response. First nivolumab was discontinued due to disease progression in seven patients and grade 3 colitis in 1 patient. Patients were subsequently treated with ipilimumab (n = 6), vemurafenib (n = 1), or no other medical treatment (n = 1). The median treatment period between first and second nivolumab was 3.0 months. Four patients received radiation therapy between first and second nivolumab. The median second nivolumab treatment period was 4.3 months. Among the eight patients who received second nivolumab, 2 (25%) patients achieved a partial response and 3 (37.5%) patients achieved stable disease as their best response. Second nivolumab was discontinued due to disease progression in seven patients. One patient continues to receive second nivolumab. Among the four patients treated with ipilimumab and radiotherapy between first and second nivolumab, the response rate was 50% and the disease control rate was 75%. This study showed that retreatment with nivolumab is an option for select metastatic melanoma

Relay tracking control for second-order multi-agent systems with damaged agents.

PubMed

Dong, Lijing; Li, Jing; Liu, Qin

2017-11-01

This paper investigates a situation where smart agents capable of sensory and mobility are deployed to monitor a designated area. A preset number of agents start tracking when a target intrudes this area. Some of the tracking agents are possible to be out of order over the tracking course. Thus, we propose a cooperative relay tracking strategy to ensure the successful tracking with existence of damaged agents. Relay means that, when a tracking agent quits tracking due to malfunction, one of the near deployed agents replaces it to continue the tracking task. This results in jump of tracking errors and dynamic switching of topology of the multi-agent system. Switched system technique is employed to solve this specific problem. Finally, the effectiveness of proposed tracking strategy and validity of the theoretical results are verified by conducting a numerical simulation. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Development of haemostatic decontaminants for treatment of wounds contaminated with chemical warfare agents. 3: Evaluation of in vitro topical decontamination efficacy using damaged skin.

PubMed

Lydon, Helen L; Hall, Charlotte A; Dalton, Christopher H; Chipman, J Kevin; Graham, John S; Chilcott, Robert P

2017-08-01

Previous studies have demonstrated that haemostatic products with an absorptive mechanism of action retain their clotting efficiency in the presence of toxic materials and are effective in decontaminating chemical warfare (CW) agents when applied to normal, intact skin. The purpose of this in vitro study was to assess three candidate haemostatic products for effectiveness in the decontamination of superficially damaged porcine skin exposed to the radiolabelled CW agents, soman (GD), VX and sulphur mustard (HD). Controlled physical damage (removal of the upper 100 μm skin layer) resulted in a significant enhancement of the dermal absorption of all three CW agents. Of the haemostatic products assessed, WoundStat™ was consistently the most effective, being equivalent in performance to a standard military decontaminant (fuller's earth). These data suggest that judicious application of haemostatic products to wounds contaminated with CW agents may be a viable option for the clinical management of casualties presenting with contaminated, haemorrhaging injuries. Further studies using a relevant animal model are required to confirm the potential clinical efficacy of WoundStat™ for treating wounds contaminated with CW agents. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Resistance profiles to antimicrobial agents in bacteria isolated from acute endodontic infections: systematic review and meta-analysis.

PubMed

Lang, Pauline M; Jacinto, Rogério C; Dal Pizzol, Tatiane S; Ferreira, Maria Beatriz C; Montagner, Francisco

2016-11-01

Infected root canal or acute apical abscess exudates can harbour several species, including Fusobacterium, Porphyromonas, Prevotella, Parvimonas, Streptococcus, Treponema, Olsenella and not-yet cultivable species. A systematic review and meta-analysis was performed to assess resistance rates to antimicrobial agents in clinical studies that isolated bacteria from acute endodontic infections. Electronic databases and the grey literature were searched up to May 2015. Clinical studies in humans evaluating the antimicrobial resistance of primary acute endodontic infection isolates were included. PRISMA guidelines were followed. A random-effect meta-analysis was employed. The outcome was described as the pooled resistance rates for each antimicrobial agent. Heterogeneity and sensitivity analyses were performed. Subgroup analyses were conducted based upon report or not of the use of antibiotics prior to sampling as an exclusion factor (subgroups A and B, respectively). Data from seven studies were extracted. Resistance rates for 15 different antimicrobial agents were evaluated (range, 3.5-40.0%). Lower resistance rates were observed for amoxicillin/clavulanic acid and amoxicillin; higher resistance rates were detected for tetracycline. Resistance rates varied according to previous use of an antimicrobial agent as demonstrated by the subgroup analyses. Heterogeneity was observed for the resistance profiles of penicillin G in subgroup A and for amoxicillin, clindamycin, metronidazole and tetracycline in subgroup B. Sensitivity analyses demonstrated that resistance rates changed for metronidazole, clindamycin, tetracycline and amoxicillin. These findings suggest that clinical isolates had low resistance to β-lactams. Further well-designed studies are needed to clarify whether the differences in susceptibility among the antimicrobial agents may influence clinical responses to treatment. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights

Fundamental Study on the Development of Structural Lightweight Concrete by Using Normal Coarse Aggregate and Foaming Agent

PubMed Central

Lee, Han-Seung; Ismail, Mohamed A.; Woo, Young-Je; Min, Tae-Beom; Choi, Hyun-Kook

2014-01-01

Structural lightweight concrete (SLWC) has superior properties that allow the optimization of super tall structure systems for the process of design. Because of the limited supply of lightweight aggregates in Korea, the development of structural lightweight concrete without lightweight aggregates is needed. The physical and mechanical properties of specimens that were cast using normal coarse aggregates and different mixing ratios of foaming agent to evaluate the possibility of creating structural lightweight concrete were investigated. The results show that the density of SLWC decreases as the dosage of foaming agent increases up to a dosage of 0.6%, as observed by SEM. It was also observed that the foaming agent induced well separated pores, and that the size of the pores ranged from 50 to 100 μm. Based on the porosity of concrete specimens with foaming agent, compressive strength values of structural lightweight foam concrete (SLWFC) were obtained. It was also found that the estimated values from proposed equations for compressive strength and modulus of elasticity of SLWFC, and values obtained by actual measurements were in good agreement. Thus, this study confirms that new structural lightweight concrete using normal coarse aggregates and foaming agent can be developed successfully. PMID:28788691

Mobile Agents Applications.

ERIC Educational Resources Information Center

Martins, Rosane Maria; Chaves, Magali Ribeiro; Pirmez, Luci; Rust da Costa Carmo, Luiz Fernando

2001-01-01

Discussion of the need to filter and retrieval relevant information from the Internet focuses on the use of mobile agents, specific software components which are based on distributed artificial intelligence and integrated systems. Surveys agent technology and discusses the agent building package used to develop two applications using IBM's Aglet…

Nonylphenolethoxylates as Malarial Chloroquine Resistance Reversal Agents

PubMed Central

Crandall, Ian; Charuk, Jeffrey; Kain, Kevin C.

2000-01-01

Malaria-associated morbidity and mortality are increasing because of widespread resistance to one of the safest and least expensive antimalarials, chloroquine. The availability of an inexpensive agent that is capable of reversing chloroquine resistance would have a major impact on malaria treatment worldwide. The interaction of nonylphenolethoxylates (NPEs, commercially available synthetic surfactants) with drug-resistant Plasmodium falciparum was examined to determine if NPEs inhibited the growth of the parasites and if NPEs could sensitize resistant parasites to chloroquine. NPEs inhibited the development of the parasite when present in the low- to mid-micromolar range (5 to 90 μM), indicating that they possess antimalarial activity. Further, the presence of <10 μM concentrations of NPEs caused the 50% inhibitory concentrations for chloroquine-resistant lines to drop to levels (≤12 nM) observed for sensitive lines and generally considered to be achievable with treatment courses of chloroquine. Long-chain (>30 ethoxylate units) NPEs were found to be most active in P. falciparum, which contrasts with previously observed maximal activity of short-chain (∼9 ethoxylate units) NPEs in multidrug-resistant mammalian cell lines. NPEs may be attractive chloroquine resistance reversal agents since they are inexpensive and may be selectively directed against P. falciparum without inhibiting mammalian tissue P glycoproteins. Antimalarial preparations that include these agents may prolong the effective life span of chloroquine and other antimalarials. PMID:10952591

Comparative Safety of Antidepressant Agents for Children and Adolescents Regarding Suicidal Acts

PubMed Central

Schneeweiss, Sebastian; Patrick, Amanda R.; Solomon, Daniel H.; Dormuth, Colin R.; Miller, Matt; Mehta, Jyotsna; Lee, Jennifer C.; Wang, Philip S.

2010-01-01

OBJECTIVE The objective of this study was to assess the risk of suicide attempts and suicides after initiation of antidepressant medication use by children and adolescents, for individual agents. METHODS We conducted a 9-year cohort study by using population-wide data from British Columbia. We identified new users of antidepressants who were 10 to 18 years of age with a recorded diagnosis of depression. Study outcomes were hospitalization attributable to intentional self-harm and suicide death. RESULTS Of 20 906 children who initiated antidepressant therapy, 16 774 (80%) had no previous antidepressant use. During the first year of use, we observed 266 attempted and 3 completed suicides, which yielded an event rate of 27.04 suicidal acts per 1000 person-years (95% confidence interval [CI]: 23.9–30.5 suicidal acts per 1000 person-years). There were no meaningful differences in the rate ratios (RRs) comparing fluoxetine with citalopram (RR: 0.97 [95% CI: 0.54–1.76]), fluvoxamine (RR: 1.05 [95% CI: 0.46–2.43]), paroxetine (RR: 0.80 [95% CI: 0.47–1.37]), and sertraline (RR: 1.02 [95% CI: 0.56–1.84]). Tricyclic agents showed risks similar to those of selective serotonin reuptake inhibitors (RR: 0.92 [95% CI: 0.43–2.00]). CONCLUSION Our finding of equal event rates among antidepressant agents supports the decision of the Food and Drug Administration to include all antidepressants in the black box warning regarding potentially increased suicidality risk for children and adolescents beginning use of antidepressants. PMID:20385637

Biological warfare agents

PubMed Central

Thavaselvam, Duraipandian; Vijayaraghavan, Rajagopalan

2010-01-01

The recent bioterrorist attacks using anthrax spores have emphasized the need to detect and decontaminate critical facilities in the shortest possible time. There has been a remarkable progress in the detection, protection and decontamination of biological warfare agents as many instrumentation platforms and detection methodologies are developed and commissioned. Even then the threat of biological warfare agents and their use in bioterrorist attacks still remain a leading cause of global concern. Furthermore in the past decade there have been threats due to the emerging new diseases and also the re-emergence of old diseases and development of antimicrobial resistance and spread to new geographical regions. The preparedness against these agents need complete knowledge about the disease, better research and training facilities, diagnostic facilities and improved public health system. This review on the biological warfare agents will provide information on the biological warfare agents, their mode of transmission and spread and also the detection systems available to detect them. In addition the current information on the availability of commercially available and developing technologies against biological warfare agents has also been discussed. The risk that arise due to the use of these agents in warfare or bioterrorism related scenario can be mitigated with the availability of improved detection technologies. PMID:21829313

Spacecraft sanitation agent development

NASA Technical Reports Server (NTRS)

1972-01-01

The development of an effective sanitizing agent that is compatible with the spacecraft environment and the human occupant is discussed. Experimental results show that two sanitation agents must be used to satisfy mission requirements: one agent for personal hygiene and one for equipment maintenance. It was also recommended that a water rinse be used with the agents for best results, and that consideration be given to using the agents pressure packed or in aerosol formulations.

Previous Exposure to Anesthesia and Autism Spectrum Disorder (ASD): A Puerto Rican Population-Based Sibling Cohort Study.

PubMed

Creagh, O; Torres, H; Rivera, K; Morales-Franqui, M; Altieri-Acevedo, G; Warner, D

2016-01-01

Autism Spectrum Disorder (ASD) is characterized by impaired social interaction and communication, and by restricted and repetitive behavior, that begins usually before a child is three years old.(1) Researchers have shown that prevalence rates in the U.S. may be as high as 1 in 68.(52) A number of studies have examined the effects of early exposure to anesthesia on brain development and subsequent impairment in neurocognitive function; yet, little is known about the possible effects of anesthetic agents on social-behavioral functioning. The association between exposure to anesthesia either in uterus, during the first years of life, or later and development of Autistic Spectrum Disorder (ASD) or its severity was determined in a retrospective population based cohort study. Identify if children who had previous exposure to anesthesia either in uterus, first years of life during their developing brain years, or later, are at risk of developing ASD and its severe form of the disease. Data was obtained from structured interviews administered to a sample of 515 parents/guardians distributed in two groups: ASD = 262 children diagnosed with this condition and Non-ASD: 253 children (siblings of ASD group) without diagnosis (95% confidence interval) that freely decided to participate and agreed to a consent form. Variables studied include: demographics, diagnosis and severity of ASD, exposure to anesthesia, method of childbirth, and age of exposure Children less than 2 years of age were considered into have developing brain period. Data was analyzed using Chi-square or Fisher exact test. In contrast to non-ASD group, most of the children within ASD group were male, 76% (p=0.0001). With regards to methods of childbirth, 64% of the ASD population were vaginal delivery (VD; Non-anesthesia exposure group) and 36% cesarean delivery (CD) compared to non-autistic population with 71% VD and 29% CD, which demonstrates no statistical difference between both groups (p=0.1113). Out of

Previous Exposure to Anesthesia and Autism Spectrum Disorder (ASD): A Puerto Rican Population-Based Sibling Cohort Study.

PubMed

Creagh, O; Torres, H; Rivera, K; Morales-Franqui, M; Altieri-Acevedo, G; Warner, D

2015-01-01

Autism Spectrum Disorder (ASD) is characterized by impaired social interaction and communication, and by restricted and repetitive behavior, that begins usually before a child is three years old.1 Researchers have shown that prevalence rates in the U.S. may be as high as 1 in 68.52 A number of studies have examined the effects of early exposure to anesthesia on brain development and subsequent impairment in neurocognitive function; yet, little is known about the possible effects of anesthetic agents on social-behavioral functioning. The association between exposure to anesthesia either in uterus, during the first years of life, or later and development of Autistic Spectrum Disorder (ASD) or its severity was determined in a retrospective population based cohort study. Identify if children who had previous exposure to anesthesia either in uterus, first years of life during their developing brain years, or later, are at risk of developing ASD and its severe form of the disease. Data was obtained from structured interviews administered to a sample of 515 parents/guardians distributed in two groups: ASD = 262 children diagnosed with this condition and Non-ASD: 253 children (siblings of ASD group) without diagnosis (p = 0.8069) when comparing exposure to anesthesia in uterus to subsequent severe form of ASD. Of the 262 ASD patients, 99 had exposure to anesthetics before their diagnosis, while in Non-ASD population, 110 had exposure to anesthesia, demonstrating no statistically significant association between both groups (p = 0.2091). Out of 99 ASD patients exposed to anesthesia prior to their diagnosis, 72 were exposed before age 2. When compared to the 110 Non-ASD patients exposed to anesthesia, 86 had exposure during this developing brain period, which indicates no statistically significant association (p = 0.4207). In addition, most of the ASD children exposed to anesthesia during developing brain were diagnosed with mild degree of the disorder when compared to ASD

Agents of support: psychometric properties of the Cancer Perceived Agents of Social Support (CPASS) questionnaire.

PubMed

Goldzweig, Gil; Hasson-Ohayon, Ilanit; Meirovitz, Amichay; Braun, Michal; Hubert, Ayala; Baider, Lea

2010-11-01

The current study presents the development and the evaluation of the psychometric properties of the Cancer Perceived Agents of Social Support (CPASS). The CPASS is a new self-rating instrument devised in order to enable both cancer patients and their spouses to report on the level of perceived social support they get. The CPASS evaluates the support given by different agents of support (spouse, family, friends and spiritual or religious beliefs) in several dimensions (emotional, cognitive and instrumental). The study sample comprised 662 cancer patients and their spouses recruited during a routine medical evaluation from three major cancer centers in Israel. The participants completed the CPASS and two other standardized instruments: The ENRICH Marital Satisfaction Scale (EMS) and the Brief Symptom Inventory (BSI). Principal component analysis confirmed a three-factor structure based upon the agent of support (spouse; friends/family; spiritual/religious beliefs). Cronbach's α coefficients for the agent of support indexes were high (0.80-0.95), while Cronbach's α levels for the kind of support were lower (0.45-0.72). Smallest Space Analysis (SSA) also confirmed the theoretical structure of the CPASS. Pearson correlation coefficients to the other study variables were high and significant. As a whole, the CPASS was found to be a valid tool for the current Israeli sample. Theoretical and practical conclusions and socio-cultural implications are discussed. Copyright © 2009 John Wiley & Sons, Ltd.

Reducing Interaction Costs for Self-interested Agents

NASA Astrophysics Data System (ADS)

Zhang, Yunqi; Larson, Kate

In many multiagent systems, agents are not able to freely interact with each other or with a centralized mechanism. They may be limited in their interactions by cost or by the inherent structure of the system. Using a combinatorial auction application as motivation, we study the impact of interaction costs and structure on the strategic behaviour of self-interested agents. We present a particular model of costly agent-interaction, and argue that self-interested agents may wish to coordinate their actions with their neighbours so as to reduce their individual costs. We highlight the issues that arise in such a setting, propose a cost-sharing mechanism that agents can use, and discuss group coordination procedures. Experimental work validates our model.

Spacecraft disinfectant/cleansing agent development

NASA Technical Reports Server (NTRS)

Abbate, M.

1977-01-01

The sanitation agent container, which was selected in a trade off study, employs two chambers, a rigid outer container and an inner flexible bladder. The bladder contains the sanitation agent formulation and its release is controlled by a manually operated valve. The outer container holds a high pressure vapor. There is no void in the bladder which makes the package operation independent of orientation and therefore usable in zero gravity. Foam is developed by a low boiling point fluid or dissolved in the product. When the product is dispensed at atmospheric presure, the evolved gas or vapor whips up a goam in the valve. The sanitation agents were initially formulated with freons which produces an excellent foam. However freon is incompatible with the life support system and was replaced with carbon dioxide dissolved at high pressure. The CO2 system may limit high temperature exposure to prevent leakage or package distortion. The sanitation agents have been shown to be effective in cleaning soils from personnel and material.

Randomised Comparative Study on Propofol and Diazepam as a Sedating Agent in Day Care Surgery.

PubMed

Nirwan, Amit S; Jain, Neha; Pragasm, Micheal; Kamblimath, Deepashri; Bhargava, Anurag; Tiwari, Saba

2014-12-01

The study was conducted to assess the usefulness by qualitative comparison between the two intravenous sedative drugs, Diazepam and Propofol and to provide sedation in apprehensive and uncooperative patients undergoing day care oral surgical procedures. The present study was conducted on 20 adult patients, 10 in each group (Propofol and Diazepam) irrespective of age and sex. Intravenous sedation of Propofol compared with Diazepam in terms of onset of action, recovery, and anterograde amnesia, patient co-operation, surgeon's convenience and side effects and other parameters. Propofol was found to be the superior sedating agent compared to Diazepam, having rapid onset and predictability of action, profoundness of amnesia and a faster recovery period, offering advantages of early patient discharge and better patient compliance. Propofol was found to be an ideal sedating agent in day care oral surgical procedures.

Genomic Phenotyping by Barcode Sequencing Broadly Distinguishes between Alkylating Agents, Oxidizing Agents, and Non-Genotoxic Agents, and Reveals a Role for Aromatic Amino Acids in Cellular Recovery after Quinone Exposure

PubMed Central

Svensson, J. Peter; Quirós Pesudo, Laia; McRee, Siobhan K.; Adeleye, Yeyejide; Carmichael, Paul; Samson, Leona D.

2013-01-01

Toxicity screening of compounds provides a means to identify compounds harmful for human health and the environment. Here, we further develop the technique of genomic phenotyping to improve throughput while maintaining specificity. We exposed cells to eight different compounds that rely on different modes of action: four genotoxic alkylating (methyl methanesulfonate (MMS), N-Methyl-N-nitrosourea (MNU), N,N′-bis(2-chloroethyl)-N-nitroso-urea (BCNU), N-ethylnitrosourea (ENU)), two oxidizing (2-methylnaphthalene-1,4-dione (menadione, MEN), benzene-1,4-diol (hydroquinone, HYQ)), and two non-genotoxic (methyl carbamate (MC) and dimethyl sulfoxide (DMSO)) compounds. A library of S. cerevisiae 4,852 deletion strains, each identifiable by a unique genetic ‘barcode’, were grown in competition; at different time points the ratio between the strains was assessed by quantitative high throughput ‘barcode’ sequencing. The method was validated by comparison to previous genomic phenotyping studies and 90% of the strains identified as MMS-sensitive here were also identified as MMS-sensitive in a much lower throughput solid agar screen. The data provide profiles of proteins and pathways needed for recovery after both genotoxic and non-genotoxic compounds. In addition, a novel role for aromatic amino acids in the recovery after treatment with oxidizing agents was suggested. The role of aromatic acids was further validated; the quinone subgroup of oxidizing agents were extremely toxic in cells where tryptophan biosynthesis was compromised. PMID:24040048

Exploratory Study on the Effects of Novel Diamine Curing Agents and Isocyanate Precursors on the Properties of New Epoxy and Urethane Adhesives

NASA Technical Reports Server (NTRS)

Glasgow, D. Gerald; Garthwait, Clayborn

1977-01-01

This report covers the results of investigations directed toward studying the effects of novel aromatic diamine structures on epoxy adhesive properties and includes work done under a modification to the original contract. Three aromatic diamines based on diphenylsulfone and benzophenone were studied as epoxy adhesive curing agents. Previously found differences in adhesive strengths for meta vs para orientation were not found in these series. The use of aluminum and alumina as fillers in a m,m'-methylene dianiline-cured epoxy adhesive was not found to be beneficial to adhesive strength. Alumina filled adhesives had much lower strength than unfilled adhesives. The unfilled m,m'-methylene dianiline-based epoxy adhesive had excellent resistance to moisture relative to a p,p'-methylene dianiline-based adhesive and maintained good strengths up to 250 F. A glass fiber composite based on a m,m'-methylene dianiline-cured epoxy appeared to be equivalent to the p,p'-methylene dianiline-cured epoxy as judged by short beam shear tests.

Infectious agents identified in aborted swine fetuses in a high-density breeding area: a three-year study.

PubMed

Salogni, Cristian; Lazzaro, Massimiliano; Giacomini, Enrico; Giovannini, Stefano; Zanoni, Mariagrazia; Giuliani, Matteo; Ruggeri, Jessica; Pozzi, Paolo; Pasquali, Paolo; Boniotti, Maria Beatrice; Alborali, Giovanni Loris

2016-09-01

Reproductive failure in sows is one of the most important factors affecting pig breeding. Many reproductive disorders are linked to both environmental factors and infectious agents. The goal of our study was to determine the presence of pathogens that are known to cause abortion, considering a set of conditioning factors, such as seasonality and pregnancy period. A large number of aborted fetuses (1,625 fetuses from 140 farms) from a high-density breeding area in northern Italy was analyzed for a period of 3 years. The pigs were diagnosed based on direct (culture, PCR) or indirect (enzyme-linked immunosorbent assay) evidence. An infectious etiologic agent was found in 323 of 549 cases of abortion (58.8%). These included viral agents (Porcine circovirus-2, 138/323; Porcine reproductive and respiratory syndrome virus, 108/323; porcine parvovirus, 20/323; pseudorabies virus, 6/323; and Encephalomyocarditis virus, 3/323) and bacteria (Escherichia coli, 64/323; Streptococcus sp., 63/323; Staphylococcus sp., 5/323; Pasteurella sp., 3/323; Shigella sp., 1/323; and Yersinia sp., 1/323). This study describes the prevalence of infectious agents involved in reproductive failure in a high-density swine population. The data can be useful to swine breeders, practitioners, and medical specialists in monitoring animal health and in supervising the breeding process. © 2016 The Author(s).

99m Tc-tazobactam, a novel infection imaging agent: Radiosynthesis, quality control, biodistribution, and infection imaging studies.

PubMed

Rasheed, Rashid; Naqvi, Syed Ali Raza; Gillani, Syed Jawad Hussain; Zahoor, Ameer Fawad; Jielani, Asif; Saeed, Nidda

2017-05-15

The radiolabeled drug 99m Tc-tazobactam ( 99m Tc-TZB) was developed and assessed as an infection imaging agent in Pseudomonas aeruginosa and Salmonella enterica infection-induced animal models by comparing with inflammation induced animal models. Radiosynthesis of 99m Tc-TZB was assessed while changing ligand concentration, reducing agent concentration, pH, and reaction time while keeping radioactivity constant (~370 MBq). Percent labeling of the resulting complex was measured using paper chromatography and instant thin layer chromatography. The analysis of the 99m Tc-TZB complex indicated >95% labeling yield and electrophoresis revealed complex is neutral in nature. The biodistribution study also showed predominantly renal excretion; however liver, stomach, and intestine also showed slight tracer agent uptake. The agent significantly accumulated in Pseudomonas aeruginosa and Salmonella enterica infection induced tissues 3.58 ± 0.26% and 2.43 ± 0.42% respectively at 1 hour postinjection. The inflamed tissue failed to uptake noticeable activity at 1 hour time point. The scintigraphic study results were found in accordance with biodistribution pattern. On the basis of our preliminary results, the newly developed 99m Tc-TZB can be used to diagnose bacterial infection and to discriminate between infected and inflamed tissues. Copyright © 2017 John Wiley & Sons, Ltd.

Non-operative anti-caries agents and dental caries increment among adults at high caries risk: a retrospective cohort study.

PubMed

Chaffee, Benjamin W; Cheng, Jing; Featherstone, John D B

2015-09-24

Consensus guidelines support non-operative preventives for dental caries management; yet, their use in practice is far from universal. The purpose of this study was to evaluate the effectiveness of non-operative anti-caries agents in caries prevention among high caries risk adults at a university clinic where risk-based caries management is emphasized. This retrospective observational study drew data from the electronic patient records of non-edentulous adult patients deemed to be at high risk for dental caries during baseline oral evaluations that were completed between July 1, 2007 and December 31, 2012 at a dental university in the United States. We calculated and compared adjusted mean estimates for the number of new decayed or restored teeth (DFT increment) from baseline to the next completed oral evaluation (N = 2,724 patients with follow-up) across three categories of delivery of non-operative anti-caries agents (e.g., high-concentration fluoride toothpaste, chlorhexidine rinse, xylitol products): never, at a single appointment, or at ≥2 appointments ≥4 weeks apart. Estimates were adjusted for patient and provider characteristics, baseline dental status, losses-to-follow-up, and follow-up time. Approximately half the patients did not receive any form of non-operative anti-caries agent. Most that received anti-caries agents were given more than one type of product in combination. One-time delivery of anti-caries agents was associated with a similar DFT increment as receiving no such therapy (difference in increment: -0.04; 95% CI: -0.28, 0.21). However, repeated, spaced delivery of anti-caries agents was associated with approximately one decayed or restored tooth prevented over 18 months for every three patients treated (difference in increment: -0.35; 95% CI: -0.65, -0.08). These results lend evidence that repeatedly receiving anti-caries agents can reduce tooth decay among high-risk patients engaged in regular dental care.

From automata to animate beings: the scope and limits of attributing socialness to artificial agents.

PubMed

Hortensius, Ruud; Cross, Emily S

2018-05-11

Understanding the mechanisms and consequences of attributing socialness to artificial agents has important implications for how we can use technology to lead more productive and fulfilling lives. Here, we integrate recent findings on the factors that shape behavioral and brain mechanisms that support social interactions between humans and artificial agents. We review how visual features of an agent, as well as knowledge factors within the human observer, shape attributions across dimensions of socialness. We explore how anthropomorphism and dehumanization further influence how we perceive and interact with artificial agents. Based on these findings, we argue that the cognitive reconstruction within the human observer is likely to be far more crucial in shaping our interactions with artificial agents than previously thought, while the artificial agent's visual features are possibly of lesser importance. We combine these findings to provide an integrative theoretical account based on the "like me" hypothesis, and discuss the key role played by the Theory-of-Mind network, especially the temporal parietal junction, in the shift from mechanistic to social attributions. We conclude by highlighting outstanding questions on the impact of long-term interactions with artificial agents on the behavioral and brain mechanisms of attributing socialness to these agents. © 2018 New York Academy of Sciences.

Indirect effects of host-specific biological control agents

Treesearch

Dean E. Pearson; Ragan M. Callaway

2003-01-01

Biological control is a crucial tool in the battle against biological invasions, but biocontrol agents can have a deleterious impact on native species. Recognition of risks associated with host shifting has increased the emphasis on host specificity of biocontrol agents for invasive weeds. However, recent studies indicate host-specific biocontrol agents can...

Preparing Students for Future Learning with Teachable Agents

ERIC Educational Resources Information Center

Chin, Doris B.; Dohmen, Ilsa M.; Cheng, Britte H.; Oppezzo, Marily A.; Chase, Catherine C.; Schwartz, Daniel L.

2010-01-01

One valuable goal of instructional technologies in K-12 education is to prepare students for future learning. Two classroom studies examined whether Teachable Agents (TA) achieves this goal. TA is an instructional technology that draws on the social metaphor of teaching a computer agent to help students learn. Students teach their agent by…

[Biological agents].

PubMed

Amano, Koichi

2009-03-01

There are two types of biological agents for the treatment of rheumatoid arthritis (RA); monoclonal antibodies and recombinant proteins. Among the latter, etanercept, a recombinant fusion protein of soluble TNF receptor and IgG was approved in 2005 in Japan. The post-marketing surveillance of 13,894 RA patients revealed the efficacy and safety profiles of etanercept in the Japanese population, as well as overseas studies. Abatacept, a recombinant fusion protein of CTLA4 and IgG, is another biological agent for RA. Two clinical trials disclosed the efficacy of abatacept for difficult-to-treat patients: the AIM for MTX-resistant cases and the ATTAIN for patients who are resistant to anti-TNF. The ATTEST trial suggested abatacept might have more acceptable safety profile than infliximab. These biologics are also promising for the treatment of RA for not only relieving clinical symptoms and signs but retarding structural damage.

Enhanced Positive-Contrast Visualization of Paramagnetic Contrast Agents Using Phase Images

PubMed Central

Mills, Parker H.; Ahrens, Eric T.

2009-01-01

Iron oxide–based MRI contrast agents are increasingly being used to noninvasively track cells, target molecular epitopes, and monitor gene expression in vivo. Detecting regions of contrast agent accumulation can be challenging if resulting contrast is subtle relative to endogenous tissue hypointensities. A postprocessing method is presented that yields enhanced positive-contrast images from the phase map associated with T2*-weighted MRI data. As examples, the method was applied to an agarose gel phantom doped with superparamagnetic iron-oxide nanoparticles and in vivo and ex vivo mouse brains inoculated with recombinant viruses delivering transgenes that induce overexpression of paramagnetic ferritin. Overall, this approach generates images that exhibit a 1- to 8-fold improvement in contrast-to-noise ratio in regions where paramagnetic agents are present compared to conventional magnitude images. This approach can be used in conjunction with conventional T2* pulse sequences, requires no prescans or increased scan time, and can be applied retrospectively to previously acquired data. PMID:19780169

A review of the possible mechanisms of action of tocotrienol - a potential antiosteoporotic agent.

PubMed

Chin, Kok-Yong; Mo, Huanbiao; Soelaiman, Ima-Nirwana

2013-12-01

Osteoporosis is posing a tremendous healthcare problem globally. Much effort has been invested in finding novel antiosteoporotic agents to stop the progression of this disease. Tocotrienol, one of the isoforms of vitamin E, is poised as a potential antiosteoporotic agent. Previous studies showed that tocotrienol as a single isomer or as a mixture demonstrated both anabolic and antiresorptive effects in various rodent models of osteoporosis. In vitro experiments further demonstrated that tocotrienol could up-regulate genes related to osteoblastogenesis and modify receptor activator of nuclear factor kappa B signaling against osteoclastogenesis. Additionally, tocotrienol was also shown to be a strong 3- hydroxy-3-methyl-glutaryl-CoA reductase down-regulator with a mechanism different from that of statins. Inhibition of the mevalonate pathway affects both osteoblast and osteoclast formation in favor of the former. Tocopherol, a more commonly used isoform of vitamin E does not possess similar effects. Tocotrienol is also a potent antioxidant. It can scavenge free radicals and prevent oxidative damage on osteoblast thus promoting its survival. It may also up-regulate the antioxidant defense network in osteoclast and indirectly act against free radical signaling essential in osteoclastogenesis. The effects of tocotrienol on Wnt/β-catenin signaling essential in osteoblastogenesis have not been determined. More mechanistic studies need to be conducted to illustrate the antiosteoporotic effects of tocotrienol. Clinical trials are also required to confirm its effects in humans. In conclusion, tocotrienol demonstrates great potential as an antiosteoporotic agent and much research effort should be invested to develop it as an agent to curb osteoporosis.

The importance of expressing antimicrobial agents on water basis in growth/no growth interface models: a case study for Zygosaccharomyces bailii.

PubMed

Dang, T D T; Vermeulen, A; Mertens, L; Geeraerd, A H; Van Impe, J F; Devlieghere, F

2011-01-31

In a previous study on Zygosaccharomyces bailii, three growth/no growth models have been developed, predicting growth probability of the yeast at different conditions typical for acidified foods (Dang, T.D.T., Mertens, L., Vermeulen, A., Geeraerd, A.H., Van Impe, J.F., Debevere, J., Devlieghere, F., 2010. Modeling the growth/no growth boundary of Z. bailii in acidic conditions: A contribution to the alternative method to preserve foods without using chemical preservatives. International Journal of Food Microbiology 137, 1-12). In these broth-based models, the variables were pH, water activity and acetic acid, with acetic acid concentration expressed in volume % on the total culture medium (i.e., broth). To continue the previous study, validation experiments were performed for 15 selected combinations of intrinsic factors to assess the performance of the model at 22°C (60days) in a real food product (ketchup). Although the majority of experimental results were consistent, some remarkable deviations between prediction and validation were observed, e.g., Z. bailii growth occurred in conditions where almost no growth had been predicted. A thorough investigation revealed that the difference between two ways of expressing acetic acid concentration (i.e., on broth basis and on water basis) is rather significant, particularly for media containing high amounts of dry matter. Consequently, the use of broth-based concentrations in the models was not appropriate. Three models with acetic acid concentration expressed on water basis were established and it was observed that predictions by these models well matched the validation results; therefore a "systematic error" in broth-based models was recognized. In practice, quantities of antimicrobial agents are often calculated based on the water content of food products. Hence, to assure reliable predictions and facilitate the application of models (developed from lab media with high dry matter contents), it is important to express

[Community health agents: profile and education].

PubMed

Marzari, Carla Kowalski; Junges, José Roque; Selli, Lucilda

2011-01-01

This research discusses the profile and education of the community health agents. There is no clarity about the kind of professional needed and the appropriate training to the fulfillment of the function. The research is a case study with exploratory methodology and qualitative approach. The data was collected with a focused group, formed by ten agents, intentional selected from those with more time in service in Family Health Strategy teams from the municipality of Santa Maria, Rio Grande do Sul State. The discussions were recorded and transcribed by the researcher. The data was interpreted by content analysis. The results pointed to some important questions concerning the identity of the community health agents: integration on the health team, insertion in the community, profile and education. The profile which emerges from the research, is not different from the one proposed by the Ministry of Health. However, the difference is the professionalization, an initiative assumed by the agent, guided by reality, which he faces in his activity. The gaps, perceived in his formation, cause the agent to construct his professional identity, determined more by the technical aspect of the scientific knowledge than by his social competence as a community agent.

Antimicrobial efficacy of oral topical agents on microorganisms associated with radiated head and neck cancer patients: an in vitro study.

PubMed

Bidra, Avinash S; Tarrand, Jeffery J; Roberts, Dianna B; Rolston, Kenneth V; Chambers, Mark S

2011-04-01

A variety of oral topical agents have been used for prevention and management of radiotherapy-induced adverse effects. The antimicrobial nature of some of the commonly used agents is unknown. The purpose of this study was to evaluate antimicrobial efficacies of various oral topical agents on common microorganisms associated with radiated head and neck cancer patients. Seven commonly used topical oral agents-0.12% chlorhexidine with alcohol, 0.12% chlorhexidine without alcohol, baking soda-salt rinse, 0.4% stannous fluoride gel, 0.63% stannous fluoride rinse, calcium phosphate mouthrinse, and acemannan hydrogel (aloe vera) rinse-were evaluated in vitro for their antimicrobial efficacies against four common microorganisms. A combination of baking soda-salt rinse and 0.4% stannous fluoride gel was evaluated as the eighth agent. The microorganisms used were Staphylococcus aureus, group B Streptococcus, Escherichia coli, and Candida albicans. An ELISA reader was used to measure the turbidity of microbial culture wells and optical density (OD) values for each of the 960 wells recorded. Mean OD values were rank ordered based on their turbidity. One-way ANOVA with Tukey HSD post hoc analysis was used to study differences in OD values (P < .05). Mean OD values classified for topical agents from lowest to highest were chlorhexidine with alcohol, chlorhexidine without alcohol, baking soda- salt, calcium phosphate rinse, and the combination of baking soda-salt and stannous fluoride gel. Mean OD values classified for microorganisms from lowest to highest were Escherichia coli, Staphylococcus aureus, group B Streptococcus, and Candida albicans. A significant difference among the antimicrobial efficacies of topical agents was evident for each of four microorganisms (P < .05). There was also a significant difference among the antimicrobial efficacies of the same topical agent on the four microorganisms tested (P < .05).

Agility: Agent - Ility Architecture

DTIC Science & Technology

2002-10-01

existing and emerging standards (e.g., distributed objects, email, web, search engines , XML, Java, Jini). Three agent system components resulted from...agents and other Internet resources and operate over the web (AgentGram), a yellow pages service that uses Internet search engines to locate XML ads for agents and other Internet resources (WebTrader).

CATS-based Agents That Err

NASA Technical Reports Server (NTRS)

Callantine, Todd J.

2002-01-01

This report describes preliminary research on intelligent agents that make errors. Such agents are crucial to the development of novel agent-based techniques for assessing system safety. The agents extend an agent architecture derived from the Crew Activity Tracking System that has been used as the basis for air traffic controller agents. The report first reviews several error taxonomies. Next, it presents an overview of the air traffic controller agents, then details several mechanisms for causing the agents to err in realistic ways. The report presents a performance assessment of the error-generating agents, and identifies directions for further research. The research was supported by the System-Wide Accident Prevention element of the FAA/NASA Aviation Safety Program.

[Reservation forms of plague infectious agent in Tuva natural focus].

PubMed

Bazanova, L P; Innokent'eva, T I

2012-01-01

Data characterizing the reservation forms of plague infectious agent in Tuva natural focus are presented in the review. Yersinia pestis was shown to persist most of the year in Citellophilus tesquorum altaicus imago --the main carrier, getting into the animal organism only for a short time. An increased ability to aggregate in autumn and accumulate in clumps of C. tesquorum altaicus females that are more adapted to survive the cold season compared with males promote the persistence of the microorganism. The plague infectious agent in the altered form survives in the organism of females not only the winter period but also longer periods of time that is demonstrated by the facts of detection of it after 646 days of staying in the carrier. Moreover Yersinia pestis can persist for more than 400 days in the substrate of the nest of long-tailed ground squirrel infected by excrements and corpses of plague fleas. The substrate of the nest infected in summer-autumn period of the previous year may determine the primary infection of ground squirrels by plague infectious agent in the next epizootic season. On ground squirrels infected during contact with nest substrate, infection of intact fleas may be possible, and so the initiation of a new cycle of transmission of the infectious agent. Adaptation of the plague infectious agent to unfavorable existence conditions in the carrier is expressed in the changes of its morphology and ultrastructure that is evidenced by the facts of isolation of the infectious agent from corpses of fleas situated in the substrate, in the L-form, as well as results of phase-contrast and electron microscopy of the digestive tract of C. tesquorum altaicus.

The influence of active vision on the exoskeleton of intelligent agents

NASA Astrophysics Data System (ADS)

Smith, Patrice; Terry, Theodore B.

2016-04-01

Chameleonization occurs when a self-learning autonomous mobile system's (SLAMR) active vision scans the surface of which it is perched causing the exoskeleton to changes colors exhibiting a chameleon effect. Intelligent agents having the ability to adapt to their environment and exhibit key survivability characteristics of its environments would largely be due in part to the use of active vision. Active vision would allow the intelligent agent to scan its environment and adapt as needed in order to avoid detection. The SLAMR system would have an exoskeleton, which would change, based on the surface it was perched on; this is known as the "chameleon effect." Not in the common sense of the term, but from the techno-bio inspired meaning as addressed in our previous paper. Active vision, utilizing stereoscopic color sensing functionality would enable the intelligent agent to scan an object within its close proximity, determine the color scheme, and match it; allowing the agent to blend with its environment. Through the use of its' optical capabilities, the SLAMR system would be able to further determine its position, taking into account spatial and temporal correlation and spatial frequency content of neighboring structures further ensuring successful background blending. The complex visual tasks of identifying objects, using edge detection, image filtering, and feature extraction are essential for an intelligent agent to gain additional knowledge about its environmental surroundings.

A Mobile Multi-Agent Information System for Ubiquitous Fetal Monitoring

PubMed Central

Su, Chuan-Jun; Chu, Ta-Wei

2014-01-01

Electronic fetal monitoring (EFM) systems integrate many previously separate clinical activities related to fetal monitoring. Promoting the use of ubiquitous fetal monitoring services with real time status assessments requires a robust information platform equipped with an automatic diagnosis engine. This paper presents the design and development of a mobile multi-agent platform-based open information systems (IMAIS) with an automated diagnosis engine to support intensive and distributed ubiquitous fetal monitoring. The automatic diagnosis engine that we developed is capable of analyzing data in both traditional paper-based and digital formats. Issues related to interoperability, scalability, and openness in heterogeneous e-health environments are addressed through the adoption of a FIPA2000 standard compliant agent development platform—the Java Agent Development Environment (JADE). Integrating the IMAIS with light-weight, portable fetal monitor devices allows for continuous long-term monitoring without interfering with a patient’s everyday activities and without restricting her mobility. The system architecture can be also applied to vast monitoring scenarios such as elder care and vital sign monitoring. PMID:24452256

Prospective, non-interventional, multicenter study of the intraocular pressure-lowering effects of prostaglandin analog/prostamide-containing therapies in previously treated patients with open-angle glaucoma or ocular hypertension

PubMed Central

Tamçelik, Nevbahar; Izgi, Belgin; Temel, Ahmet; Yildirim, Nilgun; Okka, Mehmet; Özcan, Altan; Yüksel, Nurşen; Elgin, Ufuk; Altan, Çiğdem; Ozer, Baris

2017-01-01

Objective The objective of this study was to assess the intraocular pressure (IOP)-lowering efficacy, tolerability, safety, and usage patterns of prostaglandin analog/prostamide (PGA/P)-containing topical ocular hypotensives in ocular hypertension (OHT) and primary open-angle glaucoma in the Turkish clinical setting. Methods This non-interventional, multicenter study enrolled previously treated patients who failed to achieve target IOP (or experienced unacceptable adverse events [AEs]) and were prescribed a PGA/P-containing IOP-lowering agent. Treatment was initiated at baseline (V1), and patients returned at weeks 4–6 (V2) and 8–12 (V3). The primary efficacy measure was the change in IOP from baseline at V3 in each eye. The secondary measures were physician’s assessment of IOP-lowering efficacy, patients (%) reaching target IOP determined at V1, hyperemia score, physician and patient assessment of study treatment tolerability at V3, and AE frequency/severity. A subgroup analysis of patients receiving the most common study treatment was conducted. All analyses were performed using the safety population (patients who received one or more doses and had any data available). Results Of 358 enrolled patients, 60.6% had primary open-angle glaucoma, 29.9% had secondary open-angle glaucoma (protocol amendment), and 13.1% had OHT; 13 patients had multiple diagnoses. At V3, the mean IOP change from baseline was ≥−4.2 mmHg (≥21.1%). IOP met or was lower than the target in 81.7% of patients, 95% exhibited none to mild conjunctival hyperemia (most common AE), and tolerability was rated good/very good by >91.1% of patients and physicians. The results were similar in patients who received the most common study treatment, bimatoprost 0.03%/timolol 0.5% (bim/tim; n=310). Conclusion PGA/P-containing medications, including bim/tim, significantly reduced IOP in previously treated patients with open-angle glaucoma or OHT; most reached their target IOP or an IOP even lower

Exploratory study on the effects of novel diamine curing agents and isocyanate precursors on the properties on new epoxy and urethane adhesives

NASA Technical Reports Server (NTRS)

Glasgow, D. G.; Garthwait, C.

1977-01-01

Aromatic diamines based on diphenyl sulfone and benzophenone were studied as epoxy adhesive curing agents. Previously found differences in adhesive strengths for meta vs para orientation were not found in these series. The use of aluminum and alumina as fillers in a m,m prime-methylene dianiline-cured epoxy adhesive was not found to be beneficial to adhesive strength. Alumina filled adhesives had much lower strength than unfilled adhesives. The unfilled m,m prime-methylene dianiline-based epoxy adhesive had excellent resistance to moisture relative to a p,p prime-methylene dianiline-based adhesive and maintained good strengths up to 250 F. A glass fiber composite based on a m,m prime-methylene dianiline-cured epoxy appeared to be equivalent to the p,p prime-methylene dianiline-cured epoxy as judged by short beam shear tests.

A Collective Case Study of Secondary Students' Model-Based Inquiry on Natural Selection through Programming in an Agent-Based Modeling Environment

ERIC Educational Resources Information Center

Xiang, Lin

2011-01-01

This is a collective case study seeking to develop detailed descriptions of how programming an agent-based simulation influences a group of 8th grade students' model-based inquiry (MBI) by examining students' agent-based programmable modeling (ABPM) processes and the learning outcomes. The context of the present study was a biology unit on…

Mechanistic and quantitative insight into cell surface targeted molecular imaging agent design.

PubMed

Zhang, Liang; Bhatnagar, Sumit; Deschenes, Emily; Thurber, Greg M

2016-05-05

Molecular imaging agent design involves simultaneously optimizing multiple probe properties. While several desired characteristics are straightforward, including high affinity and low non-specific background signal, in practice there are quantitative trade-offs between these properties. These include plasma clearance, where fast clearance lowers background signal but can reduce target uptake, and binding, where high affinity compounds sometimes suffer from lower stability or increased non-specific interactions. Further complicating probe development, many of the optimal parameters vary depending on both target tissue and imaging agent properties, making empirical approaches or previous experience difficult to translate. Here, we focus on low molecular weight compounds targeting extracellular receptors, which have some of the highest contrast values for imaging agents. We use a mechanistic approach to provide a quantitative framework for weighing trade-offs between molecules. Our results show that specific target uptake is well-described by quantitative simulations for a variety of targeting agents, whereas non-specific background signal is more difficult to predict. Two in vitro experimental methods for estimating background signal in vivo are compared - non-specific cellular uptake and plasma protein binding. Together, these data provide a quantitative method to guide probe design and focus animal work for more cost-effective and time-efficient development of molecular imaging agents.

Toxicity and medical countermeasure studies on the organophosphorus nerve agents VM and VX

PubMed Central

Rice, Helen; Dalton, Christopher H.; Price, Matthew E.; Graham, Stuart J.; Green, A. Christopher; Jenner, John; Groombridge, Helen J.; Timperley, Christopher M.

2015-01-01

To support the effort to eliminate the Syrian Arab Republic chemical weapons stockpile safely, there was a requirement to provide scientific advice based on experimentally derived information on both toxicity and medical countermeasures (MedCM) in the event of exposure to VM, VX or VM–VX mixtures. Complementary in vitro and in vivo studies were undertaken to inform that advice. The penetration rate of neat VM was not significantly different from that of neat VX, through either guinea pig or pig skin in vitro. The presence of VX did not affect the penetration rate of VM in mixtures of various proportions. A lethal dose of VM was approximately twice that of VX in guinea pigs poisoned via the percutaneous route. There was no interaction in mixed agent solutions which altered the in vivo toxicity of the agents. Percutaneous poisoning by VM responded to treatment with standard MedCM, although complete protection was not achieved. PMID:27547080

Toxicity and medical countermeasure studies on the organophosphorus nerve agents VM and VX.

PubMed

Rice, Helen; Dalton, Christopher H; Price, Matthew E; Graham, Stuart J; Green, A Christopher; Jenner, John; Groombridge, Helen J; Timperley, Christopher M

2015-04-08

To support the effort to eliminate the Syrian Arab Republic chemical weapons stockpile safely, there was a requirement to provide scientific advice based on experimentally derived information on both toxicity and medical countermeasures (MedCM) in the event of exposure to VM, VX or VM-VX mixtures. Complementary in vitro and in vivo studies were undertaken to inform that advice. The penetration rate of neat VM was not significantly different from that of neat VX, through either guinea pig or pig skin in vitro . The presence of VX did not affect the penetration rate of VM in mixtures of various proportions. A lethal dose of VM was approximately twice that of VX in guinea pigs poisoned via the percutaneous route. There was no interaction in mixed agent solutions which altered the in vivo toxicity of the agents. Percutaneous poisoning by VM responded to treatment with standard MedCM, although complete protection was not achieved.

An Agent-Based Cockpit Task Management System

NASA Technical Reports Server (NTRS)

Funk, Ken

1997-01-01

An agent-based program to facilitate Cockpit Task Management (CTM) in commercial transport aircraft is developed and evaluated. The agent-based program called the AgendaManager (AMgr) is described and evaluated in a part-task simulator study using airline pilots.

Mitochondrial Agents for Bipolar Disorder.

PubMed

Pereira, Círia; Chavarria, Victor; Vian, João; Ashton, Melanie Maree; Berk, Michael; Marx, Wolfgang; Dean, Olivia May

2018-03-27

Bipolar disorder is a chronic and often debilitating illness. Current treatment options (both pharmaco- and psychotherapy) have shown efficacy, but for many leave a shortfall in recovery. Advances in the understanding of the pathophysiology of bipolar disorder suggest that interventions that target mitochondrial dysfunction may provide a therapeutic benefit. This review explores the current and growing theoretical rationale as well as existing preclinical and clinical data for those therapies aiming to target the mitochondrion in bipolar disorder. A Clinicaltrials.gov and ANZCTR search was conducted for complete and ongoing trials on mitochondrial agents used in psychiatric disorders. A PubMed search was also conducted for literature published between January 1981 and July 2017. Systematic reviews, randomized controlled trials, observational studies, case series, and animal studies with an emphasis on agents affecting mitochondrial function and its role in bipolar disorder were included. The search was augmented by manually searching the references of key papers and related literature. The results were presented as a narrative review. Mitochondrial agents offer new horizons in mood disorder treatment. While some negative effects have been reported, most compounds are overall well tolerated and have generally benign side-effect profiles. The study of neuroinflammation, neurodegeneration, and mitochondrial function has contributed the understanding of bipolar disorder's pathophysiology. Agents targeting these pathways could be a potential therapeutic strategy. Future directions include identification of novel candidate mitochondrial modulators as well as rigorous and well-powered clinical trials.

Agent Based Study of Surprise Attacks:. Roles of Surveillance, Prompt Reaction and Intelligence

NASA Astrophysics Data System (ADS)

Shanahan, Linda; Sen, Surajit

Defending a confined territory from a surprise attack is seldom possible. We use molecular dynamics and statistical physics inspired agent-based simulations to explore the evolution and outcome of such attacks. The study suggests robust emergent behavior, which emphasizes the importance of accurate surveillance, automated and powerful attack response, building layout, and sheds light on the role of communication restrictions in defending such territories.

A study to define a set of requirements for cleansing agents for use in the Space Station whole body shower

NASA Technical Reports Server (NTRS)

1985-01-01

The objective of this research is to define a set of requirements for a whole body cleansing agent to be used in the Space Station Whole Body Shower System. In addition, cleansing agent candidates are to be identified that are likely to satisfy requirements defined in the first part of the study. It is understood that the main reason for having a Whole Body Shower is to satisfy the physiological, psychological and social needs of the crew throughout the duration of duty in the Space Station. The cleansing agent must also be compatible with the vortex water/gas separator and the water reclamation system. To accomplish these goals the study was divided into six tasks.

Study of photo-oxidative reactivity of sunscreening agents based on photo-oxidation of uric acid by kinetic Monte Carlo simulation.

PubMed

Moradmand Jalali, Hamed; Bashiri, Hadis; Rasa, Hossein

2015-05-01

In the present study, the mechanism of free radical production by light-reflective agents in sunscreens (TiO2, ZnO and ZrO2) was obtained by applying kinetic Monte Carlo simulation. The values of the rate constants for each step of the suggested mechanism have been obtained by simulation. The effect of the initial concentration of mineral oxides and uric acid on the rate of uric acid photo-oxidation by irradiation of some sun care agents has been studied. The kinetic Monte Carlo simulation results agree qualitatively with the existing experimental data for the production of free radicals by sun care agents. Copyright © 2015 Elsevier B.V. All rights reserved.

Social effects of an anthropomorphic help agent: humans versus computers.

PubMed

David, Prabu; Lu, Tingting; Kline, Susan; Cai, Li

2007-06-01

The purpose of this study was to examine perceptions of fairness of a computer-administered quiz as a function of the anthropomorphic features of the help agent offered within the quiz environment. The addition of simple anthropomorphic cues to a computer help agent reduced the perceived friendliness of the agent, perceived intelligence of the agent, and the perceived fairness of the quiz. These differences were observed only for male anthropomorphic cues, but not for female anthropomorphic cues. The results were not explained by the social attraction of the anthropomorphic agents used in the quiz or by gender identification with the agents. Priming of visual cues provides the best account of the data. Practical implications of the study are discussed.

Chemomechanical Caries Removal: A Review & Study of an Indigen-ously Developed Agent (Carie Care (TM) Gel) In Children.

PubMed

Venkataraghavan, Karthik; Kush, Anil; Lakshminarayana, Cs; Diwakar, Latha; Ravikumar, Puja; Patil, Shankargouda; Karthik, Sandhya

2013-08-01

The invention and application of engine driven or rotary instruments in operative treatment of carious lesions has resulted in removal of considerable toothe structure. However, with the introduction of adhesive materials for restorations, and the advent of minimal cavity design this principle has been challenged and is now considered to be too destructive to the tooth structure during caries removal. A number of techniques are available for cutting tooth tissue. The chemo mechanical method of caries removal/treatment is considered to be less painful when compared to the traditional treatment method (use of drill). The present study was carried to study the effect of an indigenously developed caries removal agent viz. Carie Care (TM) & its effectiveness as a chemo mechanical caries removal agent. How to cite this article: Venkataraghavan K, Kush A, Lakshminarayana CS, Diwakar L, Ravikumar P, Patil S, Karthik S. Chemomechanical Caries Removal: A Review & Study of an Indigenously Developed Agent (Carie Care (TM) Gel) In Children. J Int Oral Health 2013; 5(4):84-90.

Belief in supernatural agents in the face of death.

PubMed

Norenzayan, Ara; Hansen, Ian G

2006-02-01

Four studies examined whether awareness of mortality intensifies belief in supernatural agents among North Americans. In Studies 1 and 2, mortality salience led to more religiosity, stronger belief in God, and in divine intervention. In Studies 3 and 4, mortality salience increased supernatural agent beliefs even when supernatural agency was presented in a culturally alien context (divine Buddha in Study 3, Shamanic spirits in Study 4). The latter effects occurred primarily among the religiously affiliated, who were predominantly Christian. Implications for the role of supernatural agent beliefs in assuaging mortality concerns are discussed.

Toxicity studies on agent GA (Phase 2): 90 day subchronic study of GA (Tabun) in cd rats. Appendices. Final report, July 1985-August 1991

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1992-03-01

The purpose of the report is to provide essential toxicologic information on Tabun administration over a 90 day period. This toxicologic information may be used to adjust the maximum-tolerated dose for subsequent dominant-lethal and two-generation reproduction studies. The objectives were to determine the toxic effects of nerve agent exposure (e.g., target organs); and to determine the effects of nerve agent GA on sperm morphology and motility and vaginal cytology.

Preapproval and postapproval availability of published comparative efficacy research on biological agents.

PubMed

Thomas, Rachel Hutchins; Freeman, Maisha Kelly; Hughes, Peter J

2013-07-15

Preapproval and postapproval availability of published comparative efficacy studies on biological agents approved between 2000 and 2010 was investigated. Approval packages published on the Food and Drug Administration (FDA) website were examined for all biological agents approved between 2000 and 2010 to determine if comparative efficacy studies were available at the time of FDA approval. The availability of comparative efficacy studies published subsequent to approval was determined by searching PubMed for randomized, active-controlled experimental or observational study designs that measured efficacy as the primary endpoint and were relevant to the original FDA-approved indication. From 2000 to 2010, 107 biological agents were approved by FDA. Of the biological agents with alternative treatments, 54.6% had comparative efficacy data available at the time of approval. Although standard-reviewed biological agents were more likely to have comparative efficacy trials included in the FDA approval packages than priority-reviewed biological agents, statistically significant differences are unlikely. Subsequent to approval, 58.1% of biological agents had at least one published comparative efficacy trial, representing a 3.5% absolute increase in the availability of comparative efficacy studies since the time of approval. Vaccines and biological agents in the hematologic diseases, oncology, and miscellaneous diseases classes had fewer published postapproval comparative efficacy studies per agent compared with the overall group of biological agents. Nearly half of all biological agents approved for marketing between 2000 and 2010 lacked publicly accessible, active-controlled efficacy studies at the time of drug approval; a slightly greater proportion of biological agents had comparative efficacy data published subsequent to their approval.

Cutaneous challenge with chemical warfare agents in the SKH-1 hairless mouse. (I) Development of a model for screening studies in skin decontamination and protection.

PubMed

Dorandeu, F; Taysse, L; Boudry, I; Foquin, A; Hérodin, F; Mathieu, J; Daulon, S; Cruz, C; Lallement, G

2011-06-01

Exposure to lethal chemical warfare agents (CWAs) is no longer only a military issue due to the terrorist threat. Among the CWAs of concern are the organophosphorus nerve agent O-ethyl-S-(2[di-isopropylamino]ethyl)methyl-phosphonothioate (VX) and the vesicant sulfur mustard (SM). Although efficient means of decontamination are available, most of them lose their efficacy when decontamination is delayed after exposure of the bare skin. Alternatively, CWA skin penetration can be prevented by topical skin protectants. Active research in skin protection and decontamination is thus paramount. In vivo screening of decontaminants or skin protectants is usually time consuming and may be expensive depending on the animal species used. We were thus looking for a suitable, scientifically sound and cost-effective model, which is easy to handle. The euthymic hairless mouse Crl: SKH-1 (hr/hr) BR is widely used in some skin studies and has previously been described to be suitable for some experiments involving SM or SM analogs. To evaluate the response of this species, we studied the consequences of exposing male anaesthetized SKH-1 mice to either liquid VX or to SM, the latter being used in liquid form or as saturated vapours. Long-term effects of SM burn were also evaluated. The model was then used in the companion paper (Taysse et al.(1)).

Cognitive Modeling for Agent-Based Simulation of Child Maltreatment

NASA Astrophysics Data System (ADS)

Hu, Xiaolin; Puddy, Richard

This paper extends previous work to develop cognitive modeling for agent-based simulation of child maltreatment (CM). The developed model is inspired from parental efficacy, parenting stress, and the theory of planned behavior. It provides an explanatory, process-oriented model of CM and incorporates causality relationship and feedback loops from different factors in the social ecology in order for simulating the dynamics of CM. We describe the model and present simulation results to demonstrate the features of this model.

Liposome encapsulation of chelating agents

DOEpatents

Rahman, Yueh Erh

1976-01-13

A method for transferring a chelating agent across a cellular membrane by encapsulating the charged chelating agent within liposomes and carrying the liposome-encapsulated chelating agent to the cellular membrane where the liposomes containing the chelating agent will be taken up by the cells, thereby transferring the chelating agent across the cellular membrane. A chelating agent can be introduced into the interior of a cell of a living organism wherein the liposomes will be decomposed, releasing the chelating agent to the interior of the cell. The released chelating agent will complex intracellularly deposited toxic heavy metals, permitting the more soluble metal complex to transfer across the cellular membrane from the cell and subsequently be removed from the living organism.

Double agents and secret agents: the emerging fields of exogenous chemical exchange saturation transfer and T2-exchange magnetic resonance imaging contrast agents for molecular imaging.

PubMed

Daryaei, Iman; Pagel, Mark D

2015-01-01

Two relatively new types of exogenous magnetic resonance imaging contrast agents may provide greater impact for molecular imaging by providing greater specificity for detecting molecular imaging biomarkers. Exogenous chemical exchange saturation transfer (CEST) agents rely on the selective saturation of the magnetization of a proton on an agent, followed by chemical exchange of a proton from the agent to water. The selective detection of a biomarker-responsive CEST signal and an unresponsive CEST signal, followed by the ratiometric comparison of these signals, can improve biomarker specificity. We refer to this improvement as a "double-agent" approach to molecular imaging. Exogenous T 2 -exchange agents also rely on chemical exchange of protons between the agent and water, especially with an intermediate rate that lies between the slow exchange rates of CEST agents and the fast exchange rates of traditional T 1 and T 2 agents. Because of this intermediate exchange rate, these agents have been relatively unknown and have acted as "secret agents" in the contrast agent research field. This review exposes these secret agents and describes the merits of double agents through examples of exogenous agents that detect enzyme activity, nucleic acids and gene expression, metabolites, ions, redox state, temperature, and pH. Future directions are also provided for improving both types of contrast agents for improved molecular imaging and clinical translation. Therefore, this review provides an overview of two new types of exogenous contrast agents that are becoming useful tools within the armamentarium of molecular imaging.

Duloxetine versus other anti-depressive agents for depression

PubMed Central

Cipriani, Andrea; Koesters, Markus; Furukawa, Toshi A; Nosè, Michela; Purgato, Marianna; Omori, Ichiro M; Trespidi, Carlotta; Barbui, Corrado

2014-01-01

Background Although pharmacological and psychological interventions are both effective for major depression, in primary and secondary care settings antidepressant drugs remain the mainstay of treatment. Amongst antidepressants many different agents are available. Duloxetine hydrochloride is a dual reuptake inhibitor of serotonin and norepinephrine and has been licensed by the Food and Drug Administration in the US for major depressive disorder (MDD), generalised anxiety disorder, diabetic peripheral neuropathic pain, fibromyalgia and chronic musculoskeletal pain. Objectives To assess the evidence for the efficacy, acceptability and tolerability of duloxetine in comparison with all other antidepressant agents in the acute-phase treatment of major depression. Search methods MEDLINE (1966 to 2012), EMBASE (1974 to 2012), the Cochrane Collaboration Depression, Anxiety and Neurosis Controlled Trials Register and the Cochrane Central Register of Controlled Trials up to March 2012. No language restriction was applied. Reference lists of relevant papers and previous systematic reviews were hand-searched. Pharmaceutical company marketing duloxetine and experts in this field were contacted for supplemental data. Selection criteria Randomised controlled trials allocating patients with major depression to duloxetine versus any other antidepressive agent. Data collection and analysis Two review authors independently extracted data and a double-entry procedure was employed. Information extracted included study characteristics, participant characteristics, intervention details and outcome measures in terms of efficacy, acceptability and tolerability. Main results A total of 16 randomised controlled trials (overall 5735 participants) were included in this systematic review. Of these, three trials were unpublished. We found 11 studies (overall 3304 participants) comparing duloxetine with one selective serotonin reuptake inhibitor (SSRI) (six studies versus paroxetine, three studies

Studies on the chemical synthesis and characterization of lead oxide nanoparticles with different organic capping agents

NASA Astrophysics Data System (ADS)

Arulmozhi, K. T.; Mythili, N.

2013-12-01

Lead oxide (PbO) nanoparticles were chemically synthesized using Lead (II) acetate as precursor. The effects of organic capping agents such as Oleic acid, Ethylene Diamine Tetra Acetic acid (EDTA) and Cetryl Tri Methyl Butoxide (CTAB) on the size and morphology of the nanoparticles were studied. Characterization techniques such as X-ray diffraction (XRD), Fourier Transform-Infrared spectroscopy (FT-IR), Photoluminescence (PL) Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive Spectroscopy (EDS) and Transmission Electron Microscopy (TEM) were used to analyse the prepared nanoparticles for their physical, structural and optical properties. The characterization studies reveal that the synthesized PbO nanoparticles had well defined crystalline structure and sizes in the range of 25 nm to 36 nm for capping agents used and 40 nm for pure PbO nanoparticles.

A CSP-Based Agent Modeling Framework for the Cougaar Agent-Based Architecture

NASA Technical Reports Server (NTRS)

Gracanin, Denis; Singh, H. Lally; Eltoweissy, Mohamed; Hinchey, Michael G.; Bohner, Shawn A.

2005-01-01

Cognitive Agent Architecture (Cougaar) is a Java-based architecture for large-scale distributed agent-based applications. A Cougaar agent is an autonomous software entity with behaviors that represent a real-world entity (e.g., a business process). A Cougaar-based Model Driven Architecture approach, currently under development, uses a description of system's functionality (requirements) to automatically implement the system in Cougaar. The Communicating Sequential Processes (CSP) formalism is used for the formal validation of the generated system. Two main agent components, a blackboard and a plugin, are modeled as CSP processes. A set of channels represents communications between the blackboard and individual plugins. The blackboard is represented as a CSP process that communicates with every agent in the collection. The developed CSP-based Cougaar modeling framework provides a starting point for a more complete formal verification of the automatically generated Cougaar code. Currently it is used to verify the behavior of an individual agent in terms of CSP properties and to analyze the corresponding Cougaar society.

Complex social waves of giant honeybees provoked by a dummy wasp support the special-agent hypothesis.

PubMed

Kastberger, Gerald; Weihmann, Frank; Hoetzl, Thomas

2010-03-01

The social waves in giant honeybees termed as shimmering are more complex than mexican waves. it has been demonstrated1 that shimmering is triggered by special agents at the nest surface. in this paper, we have used a nest that originated by amalgamation of two previously separated nests and stimulated waves by a dummy wasp moved on a miniature cable car. we illustrate the plausibility of the special-agent hypothesis1 also for complex shimmering processes.

Complex social waves of giant honeybees provoked by a dummy wasp support the special-agent hypothesis

PubMed Central

Weihmann, Frank; Hoetzl, Thomas

2010-01-01

The social waves in giant honeybees termed as shimmering are more complex than mexican waves. it has been demonstrated1 that shimmering is triggered by special agents at the nest surface. in this paper, we have used a nest that originated by amalgamation of two previously separated nests and stimulated waves by a dummy wasp moved on a miniature cable car. we illustrate the plausibility of the special-agent hypothesis1 also for complex shimmering processes. PMID:20585516

Field experiments to evaluate host plant specificity of prospective agents of Onopordum acanthium in Bulgaria

USDA-ARS?s Scientific Manuscript database

Scotch thistle, Onopordum acanthium, is an invasive alien weed in North America that originates from Europe. Previous field observations in Bulgaria have confirmed the presence of prospective biological control agents including Cassida rubiginosa, Chaetostomella cylindrica, Eublemma amoena, Larinus ...

[New lipid lowering agents].

PubMed

Cuevas, Ada; Farías, María Magdalena; Alonso, Rodrigo

2014-07-01

Statins are the preferred treatment for hypercholesterolemia and several studies have demonstrated their long-term safety and efficacy in reducing cardiovascular morbidity and mortality. However, in some cases of severe hypercholesterolemia such as homozygous and heterozygous familial hypercholesterolemia or statin intolerant patients, statins can be less efficient. In recent years, new lipid-lowering agents with novel mechanisms of action have been developed to reduce LDL-cholesterol in patients with severe hypercholesterolemia, associated or not to conventional lipid-lowering therapy. These therapies include microsomal transfer protein inhibitor (Lomitapide), antisense oligonucleotide to Apo B100 (Mipomersen) and monoclonal antibodies against Proprotein convertase subtilisin/kexin type 9 (PCSK9). Different studies have shown the great effectiveness of these new therapies. Short-term studies confirmed their adequate security profile, especially in patients with homozygous familiar hypercholesterolemia or severe hypercholesterolemia. Some of these agents have been also tested in statin-intolerant patients. However, long-term studies are needed to evaluate their safety, effectiveness and impact on cardiovascular risk reduction.

Identification of walking human model using agent-based modelling

NASA Astrophysics Data System (ADS)

Shahabpoor, Erfan; Pavic, Aleksandar; Racic, Vitomir

2018-03-01

The interaction of walking people with large vibrating structures, such as footbridges and floors, in the vertical direction is an important yet challenging phenomenon to describe mathematically. Several different models have been proposed in the literature to simulate interaction of stationary people with vibrating structures. However, the research on moving (walking) human models, explicitly identified for vibration serviceability assessment of civil structures, is still sparse. In this study, the results of a comprehensive set of FRF-based modal tests were used, in which, over a hundred test subjects walked in different group sizes and walking patterns on a test structure. An agent-based model was used to simulate discrete traffic-structure interactions. The occupied structure modal parameters found in tests were used to identify the parameters of the walking individual's single-degree-of-freedom (SDOF) mass-spring-damper model using 'reverse engineering' methodology. The analysis of the results suggested that the normal distribution with the average of μ = 2.85Hz and standard deviation of σ = 0.34Hz can describe human SDOF model natural frequency. Similarly, the normal distribution with μ = 0.295 and σ = 0.047 can describe the human model damping ratio. Compared to the previous studies, the agent-based modelling methodology proposed in this paper offers significant flexibility in simulating multi-pedestrian walking traffics, external forces and simulating different mechanisms of human-structure and human-environment interaction at the same time.

Differential mobility spectroscopy for chemical agent detection

NASA Astrophysics Data System (ADS)

Griffin, M. Todd

2006-05-01

General Dynamics ATP (GDATP) and Sionex Corporation (Sionex) are carrying out a cooperative development for a handheld chemical agent detector, being called JUNO TM, which will have lower false positives, higher sensitivity, and improved interference rejection compared with presently available detectors. This enhanced performance is made possible by the use of a new principle of ion separation called Differential Mobility Spectrometry (DMS). The enhanced selectivity is provided by the field tunable nature of the Sionex differential mobility technology (microDMxTM) which forms the analytical heart of the JUNO system and enables fingerprinting of molecules by characterization of the ionized molecular behavior under multiple electric field conditions. This enhanced selectivity is valuable in addressing not only the traditional list of chemical warfare agents (CWA) but also the substantial list of Toxic Industrial Compounds (TICs) and Toxic Industrial Materials (TIMs) which may be released in warfare or terrorist situations. Experimental results showing the ability of the microDMx to reject interferences, detect and resolve live agents are presented. An additional breakthrough in the technology was realized by operating the device at a reduced pressure of around 0.5 atmospheres. This reduced pressure operation resulted in roughly doubling the spectrometers resolution over what has previously been reported [1]. Advances have also been made in power consumption and packaging leading to a device suitable for portable, handheld, applications. Experimental results illustrating the performance of the microDMx technology employed in JUNO are highlighted.

Prevention and treatment of cancer targeting chronic inflammation: research progress, potential agents, clinical studies and mechanisms.

PubMed

Zhang, Yong; Kong, Weijia; Jiang, Jiandong

2017-06-01

Numerous experimental and clinical studies indicate that chronic inflammation is closely related to the initiation, progression, and spread of cancer, in which proinflammatory cytokines, such as interleukin (IL)-6, IL-1β, and tumor necrosis factor-α (TNF-α), and transcription factors, such as nuclear factor-κB (NF-κB), and signal transducer and activator of transcription 3 (STAT3), play pivotal roles. Stimulated by proinflammatory cytokines, NF-κB and STAT3 can modulate the expression of target genes, most of which are oncogenic ones, and promote the survival, proliferation, invasion, and metastasis of cancer cells. Now it is generally accepted that inflammation-related molecules and pathways are useful targets for the prevention and treatment of cancer. In this review, we summarize the relationship between chronic inflammation and cancer and describe some potentially useful agents including aspirin, meformin, statins, and some natural products (green tea catechins, andrographolide, curcumin) for their cancer prevention and treatment activities targeting chronic inflammation. The results of typical clinical studies are included, and the influences of these agents on the proinflammatory cytokines and inflammation-related pathways are discussed. Data from the present review support that agents targeting chronic inflammation may have a broad application prospect for the prevention and treatment of cancer in the future.

Theoretical Studies Applied to the Evaluation of the DFPase Bioremediation Potential against Chemical Warfare Agents Intoxication

PubMed Central

Soares, Flávia V.; de Castro, Alexandre A.; Pereira, Ander F.; Leal, Daniel H. S.; Mancini, Daiana T.; da Cunha, Elaine F. F.; Kuca, Kamil

2018-01-01

Organophosphorus compounds (OP) are part of a group of compounds that may be hazardous to health. They are called neurotoxic agents because of their action on the nervous system, inhibiting the acetylcholinesterase (AChE) enzyme and resulting in a cholinergic crisis. Their high toxicity and rapid action lead to irreversible damage to the nervous system, drawing attention to developing new treatment methods. The diisopropyl fluorophosphatase (DFPase) enzyme has been considered as a potent biocatalyst for the hydrolysis of toxic OP and has potential for bioremediation of this kind of intoxication. In order to investigate the degradation process of the nerve agents Tabun, Cyclosarin and Soman through the wild-type DFPase, and taking into account their stereochemistry, theoretical studies were carried out. The intermolecular interaction energy and other parameters obtained from the molecular docking calculations were used to construct a data matrix, which were posteriorly treated by statistical analyzes of chemometrics, using the PCA (Principal Components Analysis) multivariate analysis. The analyzed parameters seem to be quite important for the reaction mechanisms simulation (QM/MM). Our findings showed that the wild-type DFPase enzyme is stereoselective in hydrolysis, showing promising results for the catalytic degradation of the neurotoxic agents under study, with the degradation mechanism performed through two proposed pathways. PMID:29690585

Theoretical Studies Applied to the Evaluation of the DFPase Bioremediation Potential against Chemical Warfare Agents Intoxication.

PubMed

Soares, Flávia V; de Castro, Alexandre A; Pereira, Ander F; Leal, Daniel H S; Mancini, Daiana T; Krejcar, Ondrej; Ramalho, Teodorico C; da Cunha, Elaine F F; Kuca, Kamil

2018-04-23

Organophosphorus compounds (OP) are part of a group of compounds that may be hazardous to health. They are called neurotoxic agents because of their action on the nervous system, inhibiting the acetylcholinesterase (AChE) enzyme and resulting in a cholinergic crisis. Their high toxicity and rapid action lead to irreversible damage to the nervous system, drawing attention to developing new treatment methods. The diisopropyl fluorophosphatase (DFPase) enzyme has been considered as a potent biocatalyst for the hydrolysis of toxic OP and has potential for bioremediation of this kind of intoxication. In order to investigate the degradation process of the nerve agents Tabun, Cyclosarin and Soman through the wild-type DFPase, and taking into account their stereochemistry, theoretical studies were carried out. The intermolecular interaction energy and other parameters obtained from the molecular docking calculations were used to construct a data matrix, which were posteriorly treated by statistical analyzes of chemometrics, using the PCA (Principal Components Analysis) multivariate analysis. The analyzed parameters seem to be quite important for the reaction mechanisms simulation (QM/MM). Our findings showed that the wild-type DFPase enzyme is stereoselective in hydrolysis, showing promising results for the catalytic degradation of the neurotoxic agents under study, with the degradation mechanism performed through two proposed pathways.

An in vivo study of the effect of a 38 percent hydrogen peroxide in-office whitening agent on enamel.

PubMed

Cadenaro, Milena; Navarra, Chiara Ottavia; Mazzoni, Annalisa; Nucci, Cesare; Matis, Bruce A; Di Lenarda, Roberto; Breschi, Lorenzo

2010-04-01

In an in vivo study, the authors tested the hypothesis that no difference in enamel surface roughness is detectable either during or after bleaching with a high-concentration in-office whitening agent. The authors performed profilometric and scanning electron microscopic (SEM) analyses of epoxy resin replicas of the upper right incisors of 20 participants at baseline (control) and after each bleaching treatment with a 38 percent hydrogen peroxide whitening agent, applied four times, at one-week intervals. The authors used analysis of variance for repeated measures to analyze the data statistically. The profilometric analysis of the enamel surface replicas after the in vivo bleaching protocol showed no significant difference in surface roughness parameters (P > .05) compared with those at baseline, irrespective of the time interval. Results of the correlated SEM analysis showed no relevant alteration on the enamel surface. Results of this in vivo study support the tested hypothesis that the application of a 38 percent hydrogen peroxide in-office whitening agent does not alter enamel surface roughness, even after multiple applications. The use of a 38 percent hydrogen peroxide in-office whitening agent induced no roughness alterations of the enamel surface, even after prolonged and repeated applications.

Agent tracking: a psycho-historical theory of the identification of living and social agents.

PubMed

Bullot, Nicolas J

To explain agent-identification behaviours, universalist theories in the biological and cognitive sciences have posited mental mechanisms thought to be universal to all humans, such as agent detection and face recognition mechanisms. These universalist theories have paid little attention to how particular sociocultural or historical contexts interact with the psychobiological processes of agent-identification. In contrast to universalist theories, contextualist theories appeal to particular historical and sociocultural contexts for explaining agent-identification. Contextualist theories tend to adopt idiographic methods aimed at recording the heterogeneity of human behaviours across history, space, and cultures. Defenders of the universalist approach tend to criticise idiographic methods because such methods can lead to relativism or may lack generality. To overcome explanatory limitations of proposals that adopt either universalist or contextualist approaches in isolation, I propose a philosophical model that integrates contributions from both traditions: the psycho-historical theory of agent-identification. This theory investigates how the tracking processes that humans use for identifying agents interact with the unique socio-historical contexts that support agent-identification practices. In integrating hypotheses about the history of agents with psychological and epistemological principles regarding agent-identification, the theory can generate novel hypotheses regarding the distinction between recognition-based, heuristic-based, and explanation-based agent-identification.

What Influences Agents to Pursue a Career in Extension?

ERIC Educational Resources Information Center

Arnold, Shannon; Place, Nick

2010-01-01

The qualitative study reported here explored why agricultural agents pursue an Extension career. A purposive sample was used to select twelve Florida agricultural agents. Interviews investigated positive and negative influences that affected agents' employment decisions. Grounded theory was used as the primary data analysis method (Strauss &…

Burnout among rural hospital doctors in the Western Cape: Comparison with previous South African studies.

PubMed

Liebenberg, Andrew R; Coetzee Jnr, Johan F; Conradie, Hofmeyr H; Coetzee, Johan F

2018-05-24

Burnout among doctors negatively affects health systems and, ultimately,patient care. To determine the prevalence of burnout among doctors working in the district health system in the Overberg and Cape Winelands districts of the Western Cape Province and to compare the findings with those of previous South African studies. Rural district hospitals. During 2013, a validated questionnaire (Maslach Burnout Inventory) was sent to 42 doctors working in the district health system within the referral area of the Worcester Hospital, consisting of the Overberg health district and the eastern half of the Cape Winelands. Response rate was 85.7%. Clinically significant burnout was found among 81% of respondents. High levels of burnout on all three subscales were present in 31% of participants.Burnout rates were similar to those of a previous study conducted among doctors working in the Cape Town Metropolitan Municipality primary health care facilities. Scores for emotional exhaustion (EE) and depersonalisation (DP) were greater than those of a national survey;however, the score for personal accomplishment (PA) was greater. EE and PA scores weresimilar to that of a study of junior doctors working in the Red Cross Children's Hospital;however, EE was smaller. This study demonstrates high burnout rates among doctors working at district level hospitals, similar to the prevalence thereof in the Cape Town Metropolitan primary health care facilities. Health services planning should include strategies to address and prevent burnout of which adequate staffing and improved work environment are of prime importance.

Representation in dynamical agents.

PubMed

Ward, Ronnie; Ward, Robert

2009-04-01

This paper extends experiments by Beer [Beer, R. D. (1996). Toward the evolution of dynamical neural networks for minimally cognitive behavior. In P. Maes, M. Mataric, J. Meyer, J. Pollack, & S. Wilson (Eds.), From animals to animats 4: Proceedings of the fourth international conference on simulation of adaptive behavior (pp. 421-429). MIT Press; Beer, R. D. (2003). The dynamics of active categorical perception in an evolved model agent (with commentary and response). Adaptive Behavior, 11 (4), 209-243] with an evolved, dynamical agent to further explore the question of representation in cognitive systems. Beer's environmentally-situated visual agent was controlled by a continuous-time recurrent neural network, and evolved to perform a categorical perception task, discriminating circles from diamonds. Despite the agent's high levels of discrimination performance, Beer found no evidence of internal representation in the best-evolved agent's nervous system. Here we examine the generality of this result. We evolved an agent for shape discrimination, and performed extensive behavioral analyses to test for representation. In this case we find that agents developed to discriminate equal-width shapes exhibit what Clark [Clark, A. (1997). The dynamical challenge. Cognitive Science, 21 (4), 461-481] calls "weak-substantive representation". The agent had internal configurations that (1) were understandably related to the object in the environment, and (2) were functionally used in a task relevant way when the target was not visible to the agent.

Use of antidepressive agents as a possibility in the management of periodontal diseases: A systematic review of experimental studies.

PubMed

Muniz, Francisco Wilker Mustafa Gomes; Melo, Iracema Matos; Rösing, Cassiano Kuchenbecker; de Andrade, Geanne Matos; Martins, Ricardo Souza; Moreira, Maria Mônica Studart Mendes; Carvalho, Rosimary de Sousa

2018-02-01

Antidepressant agents have anti-inflammatory functions that could be interesting as adjuvants in periodontal therapy. The aim of the present study was to analyze the effect of antidepressive drugs in the management of periodontal disease. The MEDLINE, Scopus, Embase, LILACS, and SciELO databases were searched. To be included, the studies had to be experimental studies; randomized, controlled; double-blinded; or blinded studies. A total of 565 articles were initially searched, of which five were selected for the systematic review. All studies used rats, and three different drugs were evaluated: tianeptine, venlafaxine, and fluoxetine. Two of these studies evaluated the effect of antidepressive agents in rats submitted to both ligature-induced periodontitis and depression models, showing that depressive rats had greater alveolar bone loss (ABL). Only the venlafaxine study was not able to find any significant ABL reduction in the group that used this antidepressive drug. The other four studies showed statistically-significant differences, favoring the group with the antidepressant agent. Treatments that are able to modulate the brain-neuroendocrine-immune system could be used as an adjuvant to periodontal disease management. However, studies on humans and animals are scarce, limiting the conclusion of a positive effect in the present systematic review. © 2017 John Wiley & Sons Australia, Ltd.

Synthesis and SAR studies of potent imidazopyridine anticoccidial agents.

PubMed

Liang, Gui-Bai; Qian, Xiaoxia; Feng, Dennis; Fisher, Michael; Brown, Christine M; Gurnett, Anne; Leavitt, Penny Sue; Liberator, Paul A; Misura, Andrew S; Tamas, Tamas; Schmatz, Dennis M; Wyvratt, Matthew; Biftu, Tesfaye

2007-07-01

Diaryl imidazo[1,2-a]pyridine derivatives, such as 6a and 7i, have been synthesized and found to be potent inhibitors of parasite PKG activity. The most potent compounds are the 7-isopropylaminomethyl analog 6a and 2-isopropylamino analog 7i. These compounds are also fully active in in vivo assay as anticoccidial agents at 25 ppm in feed.

An Agent-Based Model for Studying Child Maltreatment and Child Maltreatment Prevention

NASA Astrophysics Data System (ADS)

Hu, Xiaolin; Puddy, Richard W.

This paper presents an agent-based model that simulates the dynamics of child maltreatment and child maltreatment prevention. The developed model follows the principles of complex systems science and explicitly models a community and its families with multi-level factors and interconnections across the social ecology. This makes it possible to experiment how different factors and prevention strategies can affect the rate of child maltreatment. We present the background of this work and give an overview of the agent-based model and show some simulation results.

National Rates of Uterine Rupture are not Associated with Rates of Previous Caesarean Delivery: Results from the Nordic Obstetric Surveillance Study.

PubMed

Colmorn, Lotte B; Langhoff-Roos, Jens; Jakobsson, Maija; Tapper, Anna-Maija; Gissler, Mika; Lindqvist, Pelle G; Källen, Karin; Gottvall, Karin; Klungsøyr, Kari; Bøhrdahl, Per; Bjarnadóttir, Ragnhild I; Krebs, Lone

2017-05-01

Previous caesarean delivery and intended mode of delivery after caesarean are well-known individual risk factors for uterine rupture. We examined if different national rates of uterine rupture are associated with differences in national rates of previous caesarean delivery and intended mode of delivery after a previous caesarean delivery. This study is an ecological study based on data from a retrospective cohort in the Nordic countries. Data on uterine rupture were collected prospectively in each country as part of the Nordic obstetric surveillance study and included 91% of all Nordic deliveries. Information on the comparison population was retrieved from the national medical birth registers. Incidence rate ratios by previous caesarean delivery and intended mode of delivery after caesarean were modelled using Poisson regression. The incidence of uterine rupture was 7.8/10 000 in Finland and 4.6/10 000 in Denmark. Rates of caesarean (21.3%) and previous caesarean deliveries (11.5%) were highest in Denmark, while the rate of intended vaginal delivery after caesarean was highest in Finland (72%). National rates of uterine rupture were not associated with the population rates of previous caesarean but increased by 35% per 1% increase in the population rate of intended vaginal delivery and in the subpopulation of women with previous caesarean delivery by 4% per 1% increase in the rate of intended vaginal delivery. National rates of uterine rupture were not associated with national rates of previous caesarean, but increased with rates of intended vaginal delivery after caesarean. © 2017 John Wiley & Sons Ltd.

Multi-Agent Strategic Modeling in a Specific Environment

NASA Astrophysics Data System (ADS)

Gams, Matjaz; Bezek, Andraz

Multi-agent modeling in ambient intelligence (AmI) is concerned with the following task [19]: How can external observations of multi-agent systems in the ambient be used to analyze, model, and direct agent behavior? The main purpose is to obtain knowledge about acts in the environment thus enabling proper actions of the AmI systems [1]. Analysis of such systems must thus capture complex world state representation and asynchronous agent activities. Instead of studying basic numerical data, researchers often use more complex data structures, such as rules and decision trees. Some methods are extremely useful when characterizing state space, but lack the ability to clearly represent temporal state changes occurred by agent actions. To comprehend simultaneous agent actions and complex changes of state space, most often a combination of graphical and symbolical representation performs better in terms of human understanding and performance.

Biological agents for controlling excessive scarring.

PubMed

Berman, Brian

2010-01-01

The potential of various biological agents to reduce or prevent excessive scar formation has now been evaluated in numerous in-vitro studies, experimental animal models and preliminary clinical trials, in some cases with particularly promising results. Perhaps prominent among this group of biological agents, and, to some degree, possibly representing marketed compounds already being used 'off label' to manage excessive scarring, are the tumor necrosis factor alpha antagonist etanercept, and immune-response modifiers such as IFNalpha2b and imiquimod. Additional assessment of these novel agents is now justified with a view to reducing or preventing hypertrophic scars, keloid scars and the recurrence of post-excision keloid lesions.

Safety assessment of new antithrombotic agents: lessons from the EXTEND study on ximelagatran.

PubMed

Agnelli, G; Eriksson, B I; Cohen, A T; Bergqvist, D; Dahl, O E; Lassen, M R; Mouret, P; Rosencher, N; Andersson, M; Bylock, A; Jensen, E; Boberg, B

2009-01-01

Ximelagatran, the first oral direct thrombin inhibitor, was shown to be an effective antithrombotic agent but was associated with potential liver toxicity after prolonged administration. The aim of the EXTEND study was to assess safety and efficacy of extended administration (35 days) of ximelagatran or enoxaparin for the prevention of venous thromboembolism after elective hip replacement and hip fracture surgery. A follow-up period, including assessment of liver enzymes (in particular alanine aminotransferase; ALAT), until post-operative day 180 was planned, with visits at days 56 and 180. Randomization and administration of study drugs were stopped following a report of serious liver injury occurring 3 weeks after completion of ximelagatran treatment. At the time of study termination, 1158 patients had been randomized and 641 had completed the 35-day treatment; with 303 ximelagatran and 265 enoxaparin patients remaining in the study through to the day 56 follow-up visit. Overall, 58 patients showed an ALAT increase to >2x upper limit of normal: 31 treated with enoxaparin, 27 with ximelagatran. Three ximelagatran patients also showed symptoms potentially related to liver toxicity. Eleven ximelagatran patients showed an ALAT increase after study treatment ended. The clinical development of ximelagatran was terminated and the drug withdrawn from the market. Evaluation of the relative efficacy of the two treatments as specified in the protocol was impossible due to the premature termination of the study. Prolonged administration of ximelagatran was associated with an increased risk of liver toxicity. In a substantial proportion of patients, ALAT increase occurred after treatment withdrawal. The findings seen with ximelagatran should be considered when designing studies with new antithrombotic agents.

Effects of biological control agents and exotic plant invasion on deer mouse populations

Treesearch

Yvette K. Ortega; Dean E. Pearson; Kevin S. McKelvey

2004-01-01

Exotic insects are commonly introduced as biological control agents to reduce densities of invasive exotic plants. Although current biocontrol programs for weeds take precautions to minimize ecological risks, little attention is paid to the potential nontarget effects of introduced food subsidies on native consumers. Previous research demonstrated that two gall flies (...

Intraoperative imaging using intravascular contrast agent

NASA Astrophysics Data System (ADS)

Watson, Jeffrey R.; Martirosyan, Nikolay; Garland, Summer; Lemole, G. Michael; Romanowski, Marek

2016-03-01

Near-infrared (NIR) contrast agents are becoming more frequently studied in medical imaging due to their advantageous characteristics, most notably the ability to capture near-infrared signal across the tissue and the safety of the technique. This produces a need for imaging technology that can be specific for both the NIR dye and medical application. Indocyanine green (ICG) is currently the primary NIR dye used in neurosurgery. Here we report on using the augmented microscope we described previously for image guidance in a rat glioma resection. Luc-C6 cells were implanted in a rat in the left-frontal lobe and grown for 22 days. Surgical resection was performed by a neurosurgeon using augmented microscopy guidance with ICG contrast. Videos and images were acquired to evaluate image quality and resection margins. ICG accumulated in the tumor tissue due to enhanced permeation and retention from the compromised bloodbrain- barrier. The augmented microscope was capable of guiding the rat glioma resection and intraoperatively highlighted tumor tissue regions via ICG fluorescence under normal illumination of the surgical field.

Distractor Repetitions Retrieve Previous Responses and Previous Targets: Experimental Dissociations of Distractor-Response and Distractor-Target Bindings

ERIC Educational Resources Information Center

Giesen, Carina; Rothermund, Klaus

2014-01-01

Even an irrelevant distractor stimulus is integrated into event files. Subsequently repeating the distractor triggers retrieval of the event file; however, an unresolved issue concerns the question of "what" is retrieved by the distractor. While recent studies predominantly assume that the distractor retrieves the previous response, it…

Tuning the relaxation rates of dual-mode T1/T2 nanoparticle contrast agents: a study into the ideal system

NASA Astrophysics Data System (ADS)

Keasberry, Natasha A.; Bañobre-López, Manuel; Wood, Christopher; Stasiuk, Graeme. J.; Gallo, Juan; Long, Nicholas. J.

2015-09-01

Magnetic resonance imaging (MRI) is an excellent imaging modality. However the low sensitivity of the technique poses a challenge to achieving an accurate image of function at the molecular level. To overcome this, contrast agents are used; typically gadolinium based agents for T1 weighted imaging, or iron oxide based agents for T2 imaging. Traditionally, only one imaging mode is used per diagnosis although several physiological situations are known to interfere with the signal induced by the contrast agents in each individual imaging mode acquisition. Recently, the combination of both T1 and T2 imaging capabilities into a single platform has emerged as a tool to reduce uncertainties in MR image analysis. To date, contradicting reports on the effect on the contrast of the coupling of a T1 and T2 agent have hampered the application of these specialised probes. Herein, we present a systematic experimental study on a range of gadolinium-labelled magnetite nanoparticles envisioned to bring some light into the mechanism of interaction between T1 and T2 components, and advance towards the design of efficient (dual) T1 and T2 MRI probes. Unexpected behaviours observed in some of the constructs will be discussed. In this study, we demonstrate that the relaxivity of such multimodal probes can be rationally tuned to obtain unmatched potentials in MR imaging, exemplified by preparation of the magnetite-based nanoparticle with the highest T2 relaxivity described to date.Magnetic resonance imaging (MRI) is an excellent imaging modality. However the low sensitivity of the technique poses a challenge to achieving an accurate image of function at the molecular level. To overcome this, contrast agents are used; typically gadolinium based agents for T1 weighted imaging, or iron oxide based agents for T2 imaging. Traditionally, only one imaging mode is used per diagnosis although several physiological situations are known to interfere with the signal induced by the contrast agents in

Agent oriented programming

NASA Technical Reports Server (NTRS)

Shoham, Yoav

1994-01-01

The goal of our research is a methodology for creating robust software in distributed and dynamic environments. The approach taken is to endow software objects with explicit information about one another, to have them interact through a commitment mechanism, and to equip them with a speech-acty communication language. System-level applications include software interoperation and compositionality. A government application of specific interest is an infrastructure for coordination among multiple planners. Daily activity applications include personal software assistants, such as programmable email, scheduling, and new group agents. Research topics include definition of mental state of agents, design of agent languages as well as interpreters for those languages, and mechanisms for coordination within agent societies such as artificial social laws and conventions.

In Silico Design of DNP Polarizing Agents: Can Current Dinitroxides Be Improved?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Perras, Frédéric A.; Sadow, Aaron; Pruski, Marek

Numerical calculations of enhancement factors offered by dynamic nuclear polarization in solids under magic angle spinning (DNP-MAS) were performed to determine the optimal EPR parameters for a dinitroxide polarizing agent. We found that the DNP performance of a biradical is more tolerant to the relative orientation of the two nitroxide moieties than previously thought. In general, any condition in which the gyy tensor components of both radicals are perpendicular to one another is expected to have near-optimal DNP performance. These results highlight the important role of the exchange coupling, which can lessen the sensitivity of DNP performance to the inter-radicalmore » distance, but also lead to lower enhancements when the number of atoms in the linker becomes less than three. Finally, the calculations showed that the electron T1e value should be near 500μs to yield optimal performance. Importantly, the newest polarizing agents already feature all of the qualities of the optimal polarizing agent, leaving little room for further improvement. Further research into DNP polarizing agents should then target non-nitroxide radicals, as well as improvements in sample formulations to advance high-temperature DNP and limit quenching and reactivity.« less

In Silico Design of DNP Polarizing Agents: Can Current Dinitroxides Be Improved?

DOE PAGES

Perras, Frédéric A.; Sadow, Aaron; Pruski, Marek

2017-06-09

Numerical calculations of enhancement factors offered by dynamic nuclear polarization in solids under magic angle spinning (DNP-MAS) were performed to determine the optimal EPR parameters for a dinitroxide polarizing agent. We found that the DNP performance of a biradical is more tolerant to the relative orientation of the two nitroxide moieties than previously thought. In general, any condition in which the gyy tensor components of both radicals are perpendicular to one another is expected to have near-optimal DNP performance. These results highlight the important role of the exchange coupling, which can lessen the sensitivity of DNP performance to the inter-radicalmore » distance, but also lead to lower enhancements when the number of atoms in the linker becomes less than three. Finally, the calculations showed that the electron T1e value should be near 500μs to yield optimal performance. Importantly, the newest polarizing agents already feature all of the qualities of the optimal polarizing agent, leaving little room for further improvement. Further research into DNP polarizing agents should then target non-nitroxide radicals, as well as improvements in sample formulations to advance high-temperature DNP and limit quenching and reactivity.« less

Moving Just Like You: Motor Interference Depends on Similar Motility of Agent and Observer

PubMed Central

Kupferberg, Aleksandra; Huber, Markus; Helfer, Bartosz; Lenz, Claus; Knoll, Alois; Glasauer, Stefan

2012-01-01

Recent findings in neuroscience suggest an overlap between brain regions involved in the execution of movement and perception of another’s movement. This so-called “action-perception coupling” is supposed to serve our ability to automatically infer the goals and intentions of others by internal simulation of their actions. A consequence of this coupling is motor interference (MI), the effect of movement observation on the trajectory of one’s own movement. Previous studies emphasized that various features of the observed agent determine the degree of MI, but could not clarify how human-like an agent has to be for its movements to elicit MI and, more importantly, what ‘human-like’ means in the context of MI. Thus, we investigated in several experiments how different aspects of appearance and motility of the observed agent influence motor interference (MI). Participants performed arm movements in horizontal and vertical directions while observing videos of a human, a humanoid robot, or an industrial robot arm with either artificial (industrial) or human-like joint configurations. Our results show that, given a human-like joint configuration, MI was elicited by observing arm movements of both humanoid and industrial robots. However, if the joint configuration of the robot did not resemble that of the human arm, MI could longer be demonstrated. Our findings present evidence for the importance of human-like joint configuration rather than other human-like features for perception-action coupling when observing inanimate agents. PMID:22761853

Development of silica-encapsulated silver nanoparticles as contrast agents intended for dual-energy mammography.

PubMed

Karunamuni, Roshan; Naha, Pratap C; Lau, Kristen C; Al-Zaki, Ajlan; Popov, Anatoliy V; Delikatny, Edward J; Tsourkas, Andrew; Cormode, David P; Maidment, Andrew D A

2016-09-01

Dual-energy (DE) mammography has recently entered the clinic. Previous theoretical and phantom studies demonstrated that silver provides greater contrast than iodine for this technique. Our objective was to characterize and evaluate in vivo a prototype silver contrast agent ultimately intended for DE mammography. The prototype silver contrast agent was synthesized using a three-step process: synthesis of a silver core, silica encapsulation and PEG coating. The nanoparticles were then injected into mice to determine their accumulation in various organs, blood half-life and dual-energy contrast. All animal procedures were approved by the institutional animal care and use committee. The final diameter of the nanoparticles was measured to be 102 (±9) nm. The particles were removed from the vascular circulation with a half-life of 15 min, and accumulated in macrophage-rich organs such as the liver, spleen and lymph nodes. Dual-energy subtraction techniques increased the signal difference-to-noise ratio of the particles by as much as a factor of 15.2 compared to the single-energy images. These nanoparticles produced no adverse effects in mice. Silver nanoparticles are an effective contrast agent for dual-energy x-ray imaging. With further design improvements, silver nanoparticles may prove valuable in breast cancer screening and diagnosis. • Silver has potential as a contrast agent for DE mammography. • Silica-coated silver nanoparticles are biocompatible and suited for in vivo use. • Silver nanoparticles produce strong contrast in vivo using DE mammography imaging systems.

The safety of antiangiogenic agents and PARP inhibitors in platinum-sensitive recurrent ovarian cancer.

PubMed

Lorusso, Domenica; Fontanella, Caterina; Maltese, Giuseppa; Lepori, Stefano; Tripodi, Elisa; Bogani, Giorgio; Raspagliesi, Francesco

2017-06-01

Recurrence is a common event in endothelial ovarian cancer (EOC) patients, and the choice of the most appropriate treatment is driven by the platinum-free interval, molecular characteristics of the disease such as BRCA mutational status, previous treatments and toxicity. Areas covered: This review focuses on the main hematologic and non-hematologic toxicities correlated with the use of licensed antiangiogenic agents and PARP inhibitors in recurrent platinum-sensitive EOC, providing recommendations for their management. Expert opinion: The clinical research over the next years will be focused on a more precise characterization of molecular pathways underlying tumorigenesis of the five ovarian tumors, to improve the decision-making process in these rare diseases. For this purpose, new study designs and international collaborations will become mandatory. Immunotherapy, antiangiogenic agents and PARP inhibitors will be combined to build a treatment strategy algorithm which will allow patients to receive all the available treatment option, in the more appropriate sequence.

Evolution of a multi-agent system in a cyclical environment.

PubMed

Baptista, Tiago; Costa, Ernesto

2008-06-01

The synchronisation phenomena in biological systems is a current and recurring subject of scientific study. This topic, namely that of circadian clocks, served as inspiration to develop an agent-based simulation that serves the main purpose of being a proof-of-concept of the model used in the BitBang framework, that implements a modern autonomous agent model. Despite having been extensively studied, circadian clocks still have much to be investigated. Rather than wanting to learn more about the internals of this biological process, we look to study the emergence of this kind of adaptation to a daily cycle. To that end we implemented a world with a day/night cycle, and analyse the ways the agents adapt to that cycle. The results show the evolution of the agents' ability to gather food. If we look at the total number of agents over the course of an experiment, we can pinpoint the time when reproductive technology emerges. We also show that the agents adapt to the daily cycle. This circadian rhythm can be shown by analysing the variation on the agents metabolic rate, which is affected by the variation of their movement patterns. In the experiments conducted we can observe that the metabolic rate of the agents varies according to the daily cycle.

Comparison of transcutaneous contrast-enhanced ultrasound-guided injected hemostatic agents with traditional surgery treatment for liver, spleen and kidney trauma: a retrospective study.

PubMed

Wang, Dong; Lv, Faqin; Luo, Yukun; An, Lichun; Li, Junlai; Xie, Xia; Tian, Jiangke; Zhao, Weiyan; Tang, Jie

2012-10-01

There is lack of studies on the effectiveness of transcutaneous contrast-enhanced ultrasound-guided injections of hemostatic agents for liver. spleen and kidney trauma. We compared treatment by hemostatic agents to surgical treatment in a retrospective interventional human study. The study enrolled a total of 135 subjects from emergency unit of the Chinese People's Liberation Army General Hospital in Beijing. Within the cohort, 62 patients received contrast enhanced ultrasound-guided injection of hemostatic agents and the rest received surgical treatments. The injury severity score was lower in the hemostatic agent treatment group than surgical treatment group (p<0.05), but Glasgow coma scale scores did not reach statistical significance. The patients in the surgical treatment group had significantly higher hospital fees than those in the hemostatic treatment group (p<0.05), although the length of hospitalization did not significantly differ between two groups. Safety outcome variables pre- and post-treatment remained within normal limits in both groups. Hemostatic agents were more cost-effective than surgery to treat patients with liver, spleen and kidney trauma. However, given the limited sample size, subsequent studies drawing upon larger populations from multiple medical centers are necessary for follow-up.

Nitric oxide donors attenuate clongenic potential in rat C6 glioma cells treated with alkylating chemotherapeutic agents.

PubMed

Yang, Jir-Jei; Yin, Jiu-Haw; Yang, Ding-I

2007-05-11

1,3-Bis(2-chloroethyl)-1-nitrosourea (BCNU) kills tumor cells via multiple actions including alkylation and carbamoylation. Previously, we have reported that formation of S-nitrosoglutathione (GSNO) in glioma cells overexpressing inducible nitric oxide synthase (iNOS) contributed to nitric oxide (NO)-dependent carbamoylating chemoresistance against BCNU. To further characterize the effects of NO on alkylating cytotoxicity, colony formation assay was applied to evaluate the effects of various NO donors on rat C6 glioma cells challenged with alkylating agents. We demonstrate that NO donors including GSNO, diethylamine NONOate (DEA/NO), and sodium nitroprusside (SNP) substantially reduced the extent of colony formation in glioma cells treated with alkylating agents, namely methyl methanesulfonate (MMS), N-methyl-N-nitrosourea (MNU), and N-ethyl-N-nitrosourea (ENU). Without alkylating agents these NO-releasing agents alone had no effects on clongenic potential of rat C6 glioma cells. Among these three NO donors used, the effectiveness in potentiating alkylating cytotoxicity is in the order of "GSNO>DEA/NO>SNP" when applied at the same dosages. GSNO also exerted similar synergistic actions reducing the extents of colony formation when co-administrated with 1,2-bis(methylsulfonyl)-1-(2-chloroethyl)-hydrazine (compound #1), another alkylating agent that mimics the chloroethylating action of BCNU. Together with our previous findings, we propose that NO donors may be used as adjunct chemotherapy with alkylating agents for such malignant brain tumors as glioblastoma multiforme (GBM). In contrast, production of NO as a result of iNOS induction, such as that occurring after surgical resection of brain tumors, may compromise the efficacy of carbamoylating chemotherapy.

Tennessee Extension Agents' Perceptions of Performance Appraisal

ERIC Educational Resources Information Center

Donaldson, Joseph L.; French, Russell L.

2013-01-01

Performance appraisal is necessary for summative decisions about employees, such as merit pay and promotion. The research reported here describes Extension agent perceptions of their performance appraisal system. The population studied consisted of all Tennessee Extension agents (N = 312). Surveys were completed by 218 respondents, for a completed…

Adsorption study of a macro-RAFT agent onto SiO2-coated Gd2O3:Eu3+ nanorods: Requirements and limitations

NASA Astrophysics Data System (ADS)

Zou, Hua; Melro, Liliana; de Camargo Chaparro, Thaissa; de Souza Filho, Isnaldi Rodrigues; Ananias, Duarte; Bourgeat-Lami, Elodie; dos Santos, Amilton Martins; Barros-Timmons, Ana

2017-02-01

The use of a macromolecular RAFT (macro-RAFT) agent to encapsulate anisotropic nano-objects via emulsion polymerization is an emerging route to prepare polymer/inorganic colloidal nanocomposites. However, a number of requirements have to be fulfilled. This work aims at highlighting the effects of the preparative procedure and dispersion method on the amount of macro-RAFT agent adsorbed onto SiO2-coated Gd2O3:Eu3+ nanorods. The adsorption of macro-RAFT agent was studied using the depletion method with UV-vis spectrophotometry. Measurements were performed at a fixed concentration of nanorods and varying concentrations of the macro-RAFT agent in aqueous dispersion at room temperature. The adsorption isotherms showed that for the same initial macro-RAFT agent concentration, the highest adsorption capacity of the macro-RAFT agent on nanorods was usually achieved for non-calcined thin SiO2-coated nanorods under mild bath sonication.

An Embodied Agent Helps Anxious Students in Mathematics Learning

ERIC Educational Resources Information Center

Kim, Yanghee; Thayne, Jeffrey; Wei, Quan

2017-01-01

Mathematics anxiety is known to be detrimental to mathematics learning. This study explored if an embodied agent could be used to help alleviate student anxiety in classrooms. To examine this potential, agent-guided algebra lessons were developed, in which an animated agent was equipped with prescriptive instructional guidance and anxiety treating…

Preclinical animal acute toxicity studies of new developed MRI contrast agent based on gadolinium

NASA Astrophysics Data System (ADS)

Nam, I. F.; Zhuk, V. V.

2015-04-01

Acute toxicity test of new developed MRI contrast agent based on disodium salt of gadopentetic acid complex were carried out on Mus musculus and Sprague Dawley rats according to guidelines of preclinical studies [1]. Groups of six animals each were selected for experiment. Death and clinical symptoms of animals were recorded during 14 days. As a result the maximum tolerated dose (MTD) for female mice is 2.8 mM/kg of body weight, male mice - 1.4 mM/kg, female rats - 2.8 mM/kg, male rats - 5.6 mM/kg of body weight. No Observed Adverse Effect Dose (NOAEL) for female mice is 1.4 mM/kg, male mice - 0.7 mM/kg, male and female rats - 0.7 mM/kg. According to experimental data new developed MRI contrast agent based on Gd-DTPA complex is low-toxic.

Headspace Gas Chromatography Method for Studies of Reaction and Permeation of Volatile Agents with Solid Materials

DTIC Science & Technology

2015-01-01

HEADSPACE GAS CHROMATOGRAPHY METHOD FOR STUDIES OF REACTION AND PERMEATION OF...TITLE AND SUBTITLE Headspace Gas Chromatography Method for Studies of Reaction and Permeation of Volatile Agents with Solid Materials 5a...method is described for measuring the reactivity and permeability of fabrics, films, and other solid materials. Headspace gas chromatography (GC)

The effect of interstitial pressure on therapeutic agent transport: coupling with the tumor blood and lymphatic vascular systems

PubMed Central

Wu, Min; Frieboes, Hermann B.; Chaplain, Mark A.J.; McDougall, Steven R.; Cristini, Vittorio; Lowengrub, John

2014-01-01

Vascularized tumor growth is characterized by both abnormal interstitial fluid flow and the associated interstitial fluid pressure (IFP). Here, we study the effect that these conditions have on the transport of therapeutic agents during chemotherapy. We apply our recently developed vascular tumor growth model which couples a continuous growth component with a discrete angiogenesis model to show that hypertensive IFP is a physical barrier that may hinder vascular extravasation of agents through transvascular fluid flux convection, which drives the agents away from the tumor. This result is consistent with previous work using simpler models without blood flow or lymphatic drainage. We consider the vascular/interstitial/lymphatic fluid dynamics to show that tumors with larger lymphatic resistance increase the agent concentration more rapidly while also experiencing faster washout. In contrast, tumors with smaller lymphatic resistance accumulate less agents but are able to retain them for a longer time. The agent availability (area-under-the curve, or AUC) increases for less permeable agents as lymphatic resistance increases, and correspondingly decreases for more permeable agents. We also investigate the effect of vascular pathologies on agent transport. We show that elevated vascular hydraulic conductivity contributes to the highest AUC when the agent is less permeable, but leads to lower AUC when the agent is more permeable. We find that elevated interstitial hydraulic conductivity contributes to low AUC in general regardless of the transvascular agent transport capability. We also couple the agent transport with the tumor dynamics to simulate chemotherapy with the same vascularized tumor under different vascular pathologies. We show that tumors with an elevated interstitial hydraulic conductivity alone require the strongest dosage to shrink. We further show that tumors with elevated vascular hydraulic conductivity are more hypoxic during therapy and that the

Double agents and secret agents: the emerging fields of exogenous chemical exchange saturation transfer and T2-exchange magnetic resonance imaging contrast agents for molecular imaging

PubMed Central

Daryaei, Iman; Pagel, Mark D

2016-01-01

Two relatively new types of exogenous magnetic resonance imaging contrast agents may provide greater impact for molecular imaging by providing greater specificity for detecting molecular imaging biomarkers. Exogenous chemical exchange saturation transfer (CEST) agents rely on the selective saturation of the magnetization of a proton on an agent, followed by chemical exchange of a proton from the agent to water. The selective detection of a biomarker-responsive CEST signal and an unresponsive CEST signal, followed by the ratiometric comparison of these signals, can improve biomarker specificity. We refer to this improvement as a “double-agent” approach to molecular imaging. Exogenous T2-exchange agents also rely on chemical exchange of protons between the agent and water, especially with an intermediate rate that lies between the slow exchange rates of CEST agents and the fast exchange rates of traditional T1 and T2 agents. Because of this intermediate exchange rate, these agents have been relatively unknown and have acted as “secret agents” in the contrast agent research field. This review exposes these secret agents and describes the merits of double agents through examples of exogenous agents that detect enzyme activity, nucleic acids and gene expression, metabolites, ions, redox state, temperature, and pH. Future directions are also provided for improving both types of contrast agents for improved molecular imaging and clinical translation. Therefore, this review provides an overview of two new types of exogenous contrast agents that are becoming useful tools within the armamentarium of molecular imaging. PMID:27747191

Evaluation of CO2, N2 and He as Fire Suppression Agents in Microgravity

NASA Technical Reports Server (NTRS)

Ruff, Gary A.; Hicks, Michael; Pettegrew, Richard

2004-01-01

The U.S. modules of the International Space Station use gaseous CO2 as the fire extinguishing agent. This was selected as a result of extensive experience with CO2 as a fire suppressant in terrestrial applications, trade studies on various suppressants, and experiments. The selection of fire suppressants and suppression strategies for NASA s Lunar and Martian exploration missions will be based on the same studies and normal-gravity data unless reduced gravity fire suppression data is obtained. In this study, the suppressant agent concentrations required to extinguish a flame in low velocity convective flows within the 20-sec of low gravity on the KC-135 aircraft were investigated. Suppressant gas mixtures of CO2, N2, and He with the balance being oxygen/nitrogen mixtures with either 21% or 25% O2 were used to suppress flames on a 19-mm diameter PMMA cylinder in reduced gravity. For each of the suppressant mixtures, limiting concentrations were established that would extinguish the flame at any velocity. Similarly, concentrations were established that would not extinguish the flame. The limiting concentrations were generally consistent with previous studies but did suggest that geometry had an effect on the limiting conditions. Between the extinction and non-extinction limits, the suppression characteristics depended on the extinguishing agent, flow velocity, and O2 concentration. The limiting velocity data from the CO2, He, and N2 suppressants were well correlated using an effective mixture enthalpy per mole of O2, indicating that all act via O2 displacement and cooling mechanisms. In reduced gravity, the agent concentration required to suppress the flames increased as the velocity increased, up to approximately 10 cm/s (the maximum velocity evaluated in this experiment). The effective enthalpy required to extinguish flames at velocities of 10 cm/s is approximately the same as the concentrations in normal gravity. A computational study is underway to further

Proceedings of the Agent 2002 Conference on Social Agents : Ecology, Exchange, and Evolution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Macal, C., ed.; Sallach, D., ed.

2003-04-10

Welcome to the ''Proceedings'' of the third in a series of agent simulation conferences cosponsored by Argonne National Laboratory and The University of Chicago. The theme of this year's conference, ''Social Agents: Ecology, Exchange and Evolution'', was selected to foster the exchange of ideas on some of the most important social processes addressed by agent simulation models, namely: (1) The translation of ecology and ecological constraints into social dynamics; (2) The role of exchange processes, including the peer dependencies they create; and (3) The dynamics by which, and the attractor states toward which, social processes evolve. As stated in themore » ''Call for Papers'', throughout the social sciences, the simulation of social agents has emerged as an innovative and powerful research methodology. The promise of this approach, however, is accompanied by many challenges. First, modeling complexity in agents, environments, and interactions is non-trivial, and these representations must be explored and assessed systematically. Second, strategies used to represent complexities are differentially applicable to any particular problem space. Finally, to achieve sufficient generality, the design and experimentation inherent in agent simulation must be coupled with social and behavioral theory. Agent 2002 provides a forum for reviewing the current state of agent simulation scholarship, including research designed to address such outstanding issues. This year's conference introduces an extensive range of domains, models, and issues--from pre-literacy to future projections, from ecology to oligopolistic markets, and from design to validation. Four invited speakers highlighted major themes emerging from social agent simulation.« less

Flexible, secure agent development framework

DOEpatents

Goldsmith,; Steven, Y [Rochester, MN

2009-04-07

While an agent generator is generating an intelligent agent, it can also evaluate the data processing platform on which it is executing, in order to assess a risk factor associated with operation of the agent generator on the data processing platform. The agent generator can retrieve from a location external to the data processing platform an open site that is configurable by the user, and load the open site into an agent substrate, thereby creating a development agent with code development capabilities. While an intelligent agent is executing a functional program on a data processing platform, it can also evaluate the data processing platform to assess a risk factor associated with performing the data processing function on the data processing platform.

The early postpartum experience of previously infertile mothers.

PubMed

Ladores, Sigrid; Aroian, Karen

2015-01-01

To explore the lived experience of becoming a new mother from the unique perspectives of previously infertile women. A descriptive phenomenological design was used to extract the fundamental structure of the postpartum experience of previously infertile mothers. Central Florida. Twelve first-time, previously infertile mothers age 27 to 43 years. Face-to-face interviews were conducted twice with each participant. Recorded interviews were transcribed verbatim and analyzed using Colaizzi's approach. Two main themes emerged that described the early postpartum experience of first-time, previously infertile mothers: (a) lingering identity as infertile and (b) gratitude for the gift of motherhood. Participants reported that their lingering identities as infertile and immense gratitude for the gift of motherhood propelled them to establish unrealistic expectations to be perfect mothers. When they were unable to live up this expectation, they censored their feelings of inadequacy, guilt, and shame. Findings from this study may help to sensitize health care providers to the difficulties faced by previously infertile women during their transition to motherhood. © 2015 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses.

Effects of pH buffering agents on the anaerobic hydrolysis acidification stage of kitchen waste.

PubMed

Wang, Yaya; Zang, Bing; Gong, Xiaoyan; Liu, Yu; Li, Guoxue

2017-10-01

This study investigated effects of initial pH buffering agents on the lab-scale anaerobic hydrolysis acidification stage of kitchen waste (KW). Different cheap, available and suitable buffering agents (NaOH(s), NaOH(l), CaO(s)-NaOH, KOH(l)-NaOH, K 2 HPO 4 (s)-KOH, Na 2 CO 3 (s)-NaOH) were added under optimal adjusting mode (first two days: per 16h, after: one time per day) which was obtained in previous work. The effects of buffering agents were evaluated according to indexes of pH, VFAs, NH 4 + -N, TS, VS, VS/TS, TS and VS removal rate. The results showed treatment 5 with adding K 2 HPO 4 -KOH buffering agents had the most stable pH (6.7-7.0). Also treatment 5, 2, 4 and 6 provided stable pH ranging in 5-8. Among the treatments, treatment 6 with adding Na 2 CO 3 as initial buffering agents and 10mol/L NaOH as regulator was chosen as the optimal mode for highest VFAs content (44.05g/L) with high acetic acid and butyrate acid proportion (42.64%), TS and VS removal rate (44.84% and 58.67%, respectively), low VS/TS ratio (58.55), fewer adding dosage and low adjusting frequency. The VFAs content of treatment 6 at the end of hydrolysis acidification stage could be used for methanogenic phase of anaerobic two-phase digestion. Thus, treatment 6 (adding Na 2 CO 3 as initial buffering agents and 10mol/L NaOH as regulator) with highest VFAs content and TS and VS removal rate could be considered using in anaerobic hydrolysis acidification stage pH adjustment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Agent-based modeling: case study in cleavage furrow models.

PubMed

Mogilner, Alex; Manhart, Angelika

2016-11-07

The number of studies in cell biology in which quantitative models accompany experiments has been growing steadily. Roughly, mathematical and computational techniques of these models can be classified as "differential equation based" (DE) or "agent based" (AB). Recently AB models have started to outnumber DE models, but understanding of AB philosophy and methodology is much less widespread than familiarity with DE techniques. Here we use the history of modeling a fundamental biological problem-positioning of the cleavage furrow in dividing cells-to explain how and why DE and AB models are used. We discuss differences, advantages, and shortcomings of these two approaches. © 2016 Mogilner and Manhart. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Geometry of behavioral spaces: A computational approach to analysis and understanding of agent based models and agent behaviors

NASA Astrophysics Data System (ADS)

Cenek, Martin; Dahl, Spencer K.

2016-11-01

Systems with non-linear dynamics frequently exhibit emergent system behavior, which is important to find and specify rigorously to understand the nature of the modeled phenomena. Through this analysis, it is possible to characterize phenomena such as how systems assemble or dissipate and what behaviors lead to specific final system configurations. Agent Based Modeling (ABM) is one of the modeling techniques used to study the interaction dynamics between a system's agents and its environment. Although the methodology of ABM construction is well understood and practiced, there are no computational, statistically rigorous, comprehensive tools to evaluate an ABM's execution. Often, a human has to observe an ABM's execution in order to analyze how the ABM functions, identify the emergent processes in the agent's behavior, or study a parameter's effect on the system-wide behavior. This paper introduces a new statistically based framework to automatically analyze agents' behavior, identify common system-wide patterns, and record the probability of agents changing their behavior from one pattern of behavior to another. We use network based techniques to analyze the landscape of common behaviors in an ABM's execution. Finally, we test the proposed framework with a series of experiments featuring increasingly emergent behavior. The proposed framework will allow computational comparison of ABM executions, exploration of a model's parameter configuration space, and identification of the behavioral building blocks in a model's dynamics.

Geometry of behavioral spaces: A computational approach to analysis and understanding of agent based models and agent behaviors.

PubMed

Cenek, Martin; Dahl, Spencer K

2016-11-01

Systems with non-linear dynamics frequently exhibit emergent system behavior, which is important to find and specify rigorously to understand the nature of the modeled phenomena. Through this analysis, it is possible to characterize phenomena such as how systems assemble or dissipate and what behaviors lead to specific final system configurations. Agent Based Modeling (ABM) is one of the modeling techniques used to study the interaction dynamics between a system's agents and its environment. Although the methodology of ABM construction is well understood and practiced, there are no computational, statistically rigorous, comprehensive tools to evaluate an ABM's execution. Often, a human has to observe an ABM's execution in order to analyze how the ABM functions, identify the emergent processes in the agent's behavior, or study a parameter's effect on the system-wide behavior. This paper introduces a new statistically based framework to automatically analyze agents' behavior, identify common system-wide patterns, and record the probability of agents changing their behavior from one pattern of behavior to another. We use network based techniques to analyze the landscape of common behaviors in an ABM's execution. Finally, we test the proposed framework with a series of experiments featuring increasingly emergent behavior. The proposed framework will allow computational comparison of ABM executions, exploration of a model's parameter configuration space, and identification of the behavioral building blocks in a model's dynamics.

Dynamics and Steady States in Excitable Mobile Agent Systems

NASA Astrophysics Data System (ADS)

Peruani, Fernando; Sibona, Gustavo J.

2008-04-01

We study the spreading of excitations in 2D systems of mobile agents where the excitation is transmitted when a quiescent agent keeps contact with an excited one during a nonvanishing time. We show that the steady states strongly depend on the spatial agent dynamics. Moreover, the coupling between exposition time (ω) and agent-agent contact rate (CR) becomes crucial to understand the excitation dynamics, which exhibits three regimes with CR: no excitation for low CR, an excited regime in which the number of quiescent agents (S) is inversely proportional to CR, and, for high CR, a novel third regime, model dependent, where S scales with an exponent ξ-1, with ξ being the scaling exponent of ω with CR.

Knowledge focus via software agents

NASA Astrophysics Data System (ADS)

Henager, Donald E.

2001-09-01

The essence of military Command and Control (C2) is making knowledge intensive decisions in a limited amount of time using uncertain, incorrect, or outdated information. It is essential to provide tools to decision-makers that provide: * Management of friendly forces by treating the "friendly resources as a system". * Rapid assessment of effects of military actions againt the "enemy as a system". * Assessment of how an enemy should, can, and could react to friendly military activities. Software agents in the form of mission agents, target agents, maintenance agents, and logistics agents can meet this information challenge. The role of each agent is to know all the details about its assigned mission, target, maintenance, or logistics entity. The Mission Agent would fight for mission resources based on the mission priority and analyze the effect that a proposed mission's results would have on the enemy. The Target Agent (TA) communicates with other targets to determine its role in the system of targets. A system of TAs would be able to inform a planner or analyst of the status of a system of targets, the effect of that status, adn the effect of attacks on that system. The system of TAs would also be able to analyze possible enemy reactions to attack by determining ways to minimize the effect of attack, such as rerouting traffic or using deception. The Maintenance Agent would scheudle maintenance events and notify the maintenance unit. The Logistics Agent would manage shipment and delivery of supplies to maintain appropriate levels of weapons, fuel and spare parts. The central idea underlying this case of software agents is knowledge focus. Software agents are createad automatically to focus their attention on individual real-world entities (e.g., missions, targets) and view the world from that entities perspective. The agent autonomously monitors the entity, identifies problems/opportunities, formulates solutions, and informs the decision-maker. The agent must be

Gestational Diabetes Mellitus Management with Oral Hypoglycemic Agents

PubMed Central

Ryu, Rachel J.; Hays, Karen E.; Hebert, Mary F.

2014-01-01

Oral hypoglycemic agents such as glyburide (second generation sulfonylurea) and metformin (biguanide) are attractive alternatives to insulin due to lower cost, ease of administration, and better patient adherence. The majority of evidence from retrospective and prospective studies suggests comparable efficacy and safety of oral hypoglycemic agents such as glyburide and metformin as compared to insulin when used in the treatment of women with gestational diabetes mellitus (GDM). Glyburide and metformin have altered pharmacokinetics during pregnancy and both agents cross the placenta. In this article, we review the efficacy, safety and dosage of oral hypoglycemic agents for the treatment of gestational diabetes mellitus. Additional research is needed to evaluate optimal dosage for glyburide and metformin during pregnancy. Comparative studies evaluating the effects of glyburide and metformin on long-term maternal and fetal outcomes are also needed. PMID:25315294

Comparison of the clinical efficacy between single-agent and dual-agent concurrent chemoradiotherapy in the treatment of unresectable esophageal squamous cell carcinoma: a multicenter retrospective analysis.

PubMed

Li, Jie; Gong, Youling; Diao, Peng; Huang, Qingmei; Wen, Yixue; Lin, Binwei; Cai, Hongwei; Tian, Honggang; He, Bing; Ji, Lanlan; Guo, Ping; Miao, Jidong; Du, Xiaobo

2018-01-22