The exposome concept: a challenge and a potential driver for environmental health research.

PubMed

Siroux, Valérie; Agier, Lydiane; Slama, Rémy

2016-06-01

The exposome concept was defined in 2005 as encompassing all environmental exposures from conception onwards, as a new strategy to evidence environmental disease risk factors. Although very appealing, the exposome concept is challenging in many respects. In terms of assessment, several hundreds of time-varying exposures need to be considered, but increasing the number of exposures assessed should not be done at the cost of increased exposure misclassification. Accurately assessing the exposome currently requires numerous measurements, which rely on different technologies; resulting in an expensive set of protocols. In the future, high-throughput 'omics technologies may be a promising technique to integrate a wide range of exposures from a small numbers of biological matrices. Assessing the association between many exposures and health raises statistical challenges. Due to the correlation structure of the exposome, existing statistical methods cannot fully and efficiently untangle the exposures truly affecting the health outcome from correlated exposures. Other statistical challenges relate to accounting for exposure misclassification or identifying synergistic effects between exposures. On-going exposome projects are trying to overcome technical and statistical challenges. From a public health perspective, a better understanding of the environmental risk factors should open the way to improved prevention strategies. Copyright ©ERS 2016.

Expanding on Successful Concepts, Models, and Organization

EPA Science Inventory

If the goal of the AEP framework was to replace existing exposure models or databases for organizing exposure data with a concept, we would share Dr. von Göetz concerns. Instead, the outcome we promote is broader use of an organizational framework for exposure science. The f...

Maternal exposure to the Dutch Famine before conception and during pregnancy: quality of life and depressive symptoms in adult offspring

PubMed Central

Stein, Aryeh D.; Pierik, Frank H.; Verrips, G.H.W.; Susser, Ezra S.; Lumey, L. H.

2013-01-01

Background Gestational exposure to famine has been associated with several chronic diseases in adulthood, but few studies in humans have related prenatal famine exposure to health-related quality of life. We used the circumstances of the Dutch Famine of 1944-1945 (during which official rations were =900 kcal/day for 24 weeks) to assess whether exposure to famine prior to conception or at specified stages of pregnancy was related to self-reported health-related quality of life and depressive symptoms in adulthood. Methods We studied 923 individuals including persons born in western Holland between January 1945 and March 1946, persons born in the same 3 institutions in 1943 and 1947 and same-sex siblings of persons in series 1 or 2. Between 2003 and 2005 (mean age 59 y), we assessed self-reported quality of life with the Short Form 36 questionnaire and derived mental and physical component scores. Depressive symptoms were assessed with the Center for Epidemiologic Studies Depression scale. Results Mean mental and physical component scores were 52.4 (SD = 9.4) and 48.9 (9.0), respectively. The mean depression score was 11.6 (7.4). Age-, sex- and schooling-adjusted estimates for mutually adjusted exposures were -2.48 for the mental component score with exposure before conception (95% confidence interval = -4.46 to 0.50) and 0.07 with exposure during pregnancy (-1.15 to 1.29). Adjusted estimates for the physical component score were 1.26 with exposure before conception (-0.67 to 3.19) and -0.73 with exposure during pregnancy (1.94 to 0.48). Adjusted estimates for the depression score were 2.07 with exposure before conception (0.60 to 3.54) and 0.96 with exposure during pregnancy (0.09 to 1.88). There was no evidence of heterogeneity of effects by specific periods of pregnancy exposed to famine. Conclusions A mother's exposure to famine prior to conception of her offspring was associated with lower self-reported measures of mental health and quality of life in her adult offspring. PMID:19752733

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

Sobinoff, A.P.; Pye, V.; Nixon, B.

Benzo(a)pyrene (BaP) is an ovotoxic constituent of cigarette smoke associated with pre-mature ovarian failure and decreased rates of conception in IVF patients. Although the overall effect of BaP on female fertility has been documented, the exact molecular mechanisms behind its ovotoxicity remain elusive. In this study we examined the effects of BaP exposure on the ovarian transcriptome, and observed the effects of in vivo exposure on oocyte dysfunction. Microarray analysis of BaP cultured neonatal ovaries revealed a complex mechanism of ovotoxicity involving a small cohort of genes associated with follicular growth, cell cycle progression, and cell death. Histomorphological and immunohistochemicalmore » analysis supported these results, with BaP exposure causing increased primordial follicle activation and developing follicle atresia in vitro and in vivo. Functional analysis of oocytes obtained from adult Swiss mice treated neonatally revealed significantly increased levels of mitochondrial ROS/lipid peroxidation, and severely reduced sperm-egg binding and fusion in both low (1.5 mg/kg/daily) and high (3 mg/kg/daily) dose treatments. Our results reveal a complex mechanism of BaP induced ovotoxicity involving developing follicle atresia and accelerated primordial follicle activation, and suggest short term neonatal BaP exposure causes mitochondrial leakage resulting in reduced oolemma fluidity and impaired fertilisation in adulthood. This study highlights BaP as a key compound which may be partially responsible for the documented effects of cigarette smoke on follicular development and sub-fertility. -- Highlights: ► BaP exposure up-regulates canonical pathways linked with follicular growth/atresia. ► BaP causes primordial follicle activation and developing follicle atresia. ► BaP causes oocyte mitochondrial ROS and lipid peroxidation, impairing fertilisation. ► Short term neonatal BaP exposure compromises adult oocyte quality.« less

Flood vulnerability evaluation in complex urban areas

NASA Astrophysics Data System (ADS)

Giosa, L.; Pascale, S.; Sdao, F.; Sole, A.; Cantisani, A.

2009-04-01

This paper deals the conception, the development and the subsequent validation of an integrated numerical model for the assessment of systemic vulnerability in complex and urbanized areas, subject to flood risk. The proposed methodology is based on the application of the concept of "systemic vulnerability", the model is a mathematician-decisional model action to estimate the vulnerability of complex a territorial system during a flood event. The model uses a group of "pressure pointers" in order to define, qualitatively and quantitatively, the influence exercised on the territorial system from factors like as those physicists, social, economic, etc.. The model evaluates the exposure to the flood risk of the elements that belong to a system. The proposed model, which is based on the studies of Tamura et al., 2000; Minciardi et al., 2004; Pascale et al., 2008; considers the vulnerability not as a characteristic of a particular element at risk, but as a peculiarity of a complex territorial system, in which the different elements are reciprocally linked in a functional way. The proposed model points out the elements with the major functional lost and that make the whole system critical. This characteristic makes the proposed model able to support a correct territorial planning and a suitable management of the emergency following natural disasters such as floods. The proposed approach was tested on the study area in the city of Potenza, southern Italy.

Microbiota as a mediator of cancer progression and therapy.

PubMed

Pope, Jillian L; Tomkovich, Sarah; Yang, Ye; Jobin, Christian

2017-01-01

Complex and intricate circuitries regulate cellular proliferation, survival, and growth, and alterations of this network through genetic and epigenetic events result in aberrant cellular behaviors, often leading to carcinogenesis. Although specific germline mutations have been recognized as cancer inducers, the vast majority of neoplastic changes in humans occur through environmental exposure, lifestyle, and diet. An emerging concept in cancer biology implicates the microbiota as a powerful environmental factor modulating the carcinogenic process. For example, the intestinal microbiota influences cancer development or therapeutic responses through specific activities (immune responses, metabolites, microbial structures, and toxins). The numerous effects of microbiota on carcinogenesis, ranging from promoting, preventing, or even influencing therapeutic outcomes, highlight the complex relationship between the biota and the host. In this review, we discuss the latest findings on this complex microbial interaction with the host and highlight potential mechanisms by which the microbiota mediates such a wide impact on carcinogenesis. Copyright © 2016 Elsevier Inc. All rights reserved.

Microbiota as a mediator of cancer progression and therapy

PubMed Central

Pope, Jillian L.; Tomkovich, Sarah; Yang, Ye; Jobin, Christian

2017-01-01

Complex and intricate circuitries regulate cellular proliferation, survival, and growth, and alterations of this network through genetic and epigenetic events result in aberrant cellular behaviors, often leading to carcinogenesis. Although specific germline mutations have been recognized as cancer inducers, the vast majority of neoplastic changes in humans occur through environmental exposure, lifestyle, and diet. An emerging concept in cancer biology implicates the microbiota as a powerful environmental factor modulating the carcinogenic process. For example, the intestinal microbiota influences cancer development or therapeutic responses through specific activities (immune responses, metabolites, microbial structures, and toxins). The numerous effects of microbiota on carcinogenesis, ranging from promoting, preventing, or even influencing therapeutic outcomes, highlight the complex relationship between the biota and the host. In this review, we discuss the latest findings on this complex microbial interaction with the host and highlight potential mechanisms by which the microbiota mediates such a wide impact on carcinogenesis. PMID:27554797

Concepts, Methods, and Data Sources for Cumulative Health Risk Assessment of Multiple Chemicals, Exposures and Effects: A Resource Document (Final Report, 2008)

EPA Science Inventory

EPA announced the availability of the final report, Concepts, Methods, and Data Sources for Cumulative Health Risk Assessment of Multiple Chemicals, Exposures and Effects: A Resource Document. This report provides the concepts, methods and data sources needed to assist in...

[Family violence and mental health in adolescence: complex trauma as a developmental disorder].

PubMed

Ricciutello, Cosimo; Cheli, Mariagnese; Montenegro, Maria Elena; Campieri, Michela; Fini, Andrea; Pincanelli, Francesca

2012-01-01

To highlight the harmfulness and pervasive of early and repeated exposure to family violence from the theoretical perspective of complex trauma as a developmental disorder. A study carried out on a sample of 22 adolescents between the ages of 15 and 18, who have been entrusted to Il Faro Bologna, a Specialist Centre for child abuse and neglect. Specific areas of psychological functioning were examined. According to the NCTSN these areas are considered vulnerable to violence in primary relationships and crucial for future mental health. They are attachment, self-concept, affect regulation, cognition and behavioural control. The data was correlated with the different forms of maltreatment and the main risk factors detected in the family environment and was collected by means of clinical interviews, family and social histories, structured interviews and self-reports recommended by the NASMHPD. The data highlights a correlation between the psychic functions examined and exposure to family violence, distortion of parental empathy and parental responsibility failure. The study indicates the need: a) to raise clinical awareness of the consequences of complex trauma on development; b) to adopt specific diagnostic tools for evaluating post-traumatic outcomes; c) to carry out regular screening in order to explore histories of maltreatment in patients cared for by mental health services.

Bioavailability and bioaccumulation of metal-based engineered nanomaterials in aquatic environments: concepts and processes: chapter 5

USGS Publications Warehouse

Luoma, Samuel N.; Khan, Farhan R.; Croteau, Marie-Noële

2014-01-01

Bioavailability of Me-ENMs to aquatic organisms links their release into the environment to ecological implications. Close examination shows some important differences in the conceptual models that define bioavailability for metals and Me-ENMs. Metals are delivered to aquatic animals from Me-ENMs via water, ingestion, and incidental surface exposure. Both metal released from the Me-ENM and uptake of the nanoparticle itself contribute to bioaccumulation. Some mechanisms of toxicity and some of the metrics describing exposure may differ from metals alone. Bioavailability is driven by complex interaction of particle attributes, environmental transformations, and biological traits. Characterization of Me-ENMs is an essential part of understanding bioavailability and requires novel methodologies. The relative importance of the array of processes that could affect Me-ENM bioavailability remains poorly known, but new approaches and models are developing rapidly. Enough is known, however, to conclude that traditional approaches to exposure assessment for metals would not be adequate to assess risks from Me-ENMs.

Epigenetics: origins and implications for cancer epidemiology.

PubMed

Nise, Melissa S; Falaturi, Puran; Erren, Thomas C

2010-02-01

This paper provides information on the evolution of the 'epigenetics' concept since Aristotle and draws attention to the importance of epigenetic implications for cancer epidemiology in the years to come. Clearly, to understand origins of the concept of epigenetics, it is worthwhile to consider historical arguments associated with evolution. Equally clearly, in the last half of the 20th century, great advances in the understanding of epigenetics and, more specifically, great advances in the understanding of epigenetics in cancer have been made. However, reaping the full benefits of epigenetics lies beyond the predominant experimental studies of today. In general, epigenetics opens many doors in the field of cancer, but it also adds another level of complex, inter-related, and multi-dimensional information to research, and to its interpretation. Overall, future cancer studies should consider, or at least be sensitive to, epigenetic effects and mechanisms. Moving the focus beyond 'pristine' inheritance via DNA alone, cancer epidemiology investigating epigenetic exposures such as environmental factors (exposure to heavy metals, air pollution, arsenic and other toxins), dietary patterns (starvation, famine, contamination), and lifestyle habits (smoking, level of physical activity, and BMI) in populations has the prospect to significantly benefit future cancer prevention and treatment schemes.

Relating Complexity and Error Rates of Ontology Concepts. More Complex NCIt Concepts Have More Errors.

PubMed

Min, Hua; Zheng, Ling; Perl, Yehoshua; Halper, Michael; De Coronado, Sherri; Ochs, Christopher

2017-05-18

Ontologies are knowledge structures that lend support to many health-information systems. A study is carried out to assess the quality of ontological concepts based on a measure of their complexity. The results show a relation between complexity of concepts and error rates of concepts. A measure of lateral complexity defined as the number of exhibited role types is used to distinguish between more complex and simpler concepts. Using a framework called an area taxonomy, a kind of abstraction network that summarizes the structural organization of an ontology, concepts are divided into two groups along these lines. Various concepts from each group are then subjected to a two-phase QA analysis to uncover and verify errors and inconsistencies in their modeling. A hierarchy of the National Cancer Institute thesaurus (NCIt) is used as our test-bed. A hypothesis pertaining to the expected error rates of the complex and simple concepts is tested. Our study was done on the NCIt's Biological Process hierarchy. Various errors, including missing roles, incorrect role targets, and incorrectly assigned roles, were discovered and verified in the two phases of our QA analysis. The overall findings confirmed our hypothesis by showing a statistically significant difference between the amounts of errors exhibited by more laterally complex concepts vis-à-vis simpler concepts. QA is an essential part of any ontology's maintenance regimen. In this paper, we reported on the results of a QA study targeting two groups of ontology concepts distinguished by their level of complexity, defined in terms of the number of exhibited role types. The study was carried out on a major component of an important ontology, the NCIt. The findings suggest that more complex concepts tend to have a higher error rate than simpler concepts. These findings can be utilized to guide ongoing efforts in ontology QA.

Panel discussion review: session 1--exposure assessment and related errors in air pollution epidemiologic studies.

PubMed

Sarnat, Jeremy A; Wilson, William E; Strand, Matthew; Brook, Jeff; Wyzga, Ron; Lumley, Thomas

2007-12-01

Examining the validity of exposure metrics used in air pollution epidemiologic models has been a key focus of recent exposure assessment studies. The objective of this work has been, largely, to determine what a given exposure metric represents and to quantify and reduce any potential errors resulting from using these metrics in lieu of true exposure measurements. The current manuscript summarizes the presentations of the co-authors from a recent EPA workshop, held in December 2006, dealing with the role and contributions of exposure assessment in addressing these issues. Results are presented from US and Canadian exposure and pollutant measurement studies as well as theoretical simulations to investigate what both particulate and gaseous pollutant concentrations represent and the potential errors resulting from their use in air pollution epidemiologic studies. Quantifying the association between ambient pollutant concentrations and corresponding personal exposures has led to the concept of defining attenuation factors, or alpha. Specifically, characterizing pollutant-specific estimates for alpha was shown to be useful in developing regression calibration methods involving PM epidemiologic risk estimates. For some gaseous pollutants such as NO2 and SO2, the associations between ambient concentrations and personal exposures were shown to be complex and still poorly understood. Results from recent panel studies suggest that ambient NO2 measurements may, in some locations, be serving as surrogates to traffic pollutants, including traffic-related PM2.5, hopanes, steranes, and oxidized nitrogen compounds (rather than NO2).

On the Concept Image of Complex Numbers

ERIC Educational Resources Information Center

Nordlander, Maria Cortas; Nordlander, Edvard

2012-01-01

A study of how Swedish students understand the concept of complex numbers was performed. A questionnaire was issued reflecting the student view of own perception. Obtained answers show a variety of concept images describing how students adopt the concept of complex numbers. These concept images are classified into four categories in order to…

Parental occupational pesticide exposure and the risk of childhood leukemia in the offspring: Findings from the Childhood Leukemia International Consortium

PubMed Central

Bailey, Helen D; Fritschi, Lin; Infante-Rivard, Claire; Glass, Deborah C; Miligi, Lucia; Dockerty, John D; Lightfoot, Tracy; Clavel, Jacqueline; Roman, Eve; Spector, Logan G; Kaatsch, Peter; Metayer, Catherine; Magnani, Corrado; Milne, Elizabeth; Polychronopoulou, Sophia; Simpson, Jill; Rudant, Jérémie; Sidi, Vasiliki; Rondelli, Roberto; Orsi, Laurent; Kang, Alice; Petridou, Eleni; Schüz, Joachim

2014-01-01

Maternal occupational pesticide exposure during pregnancy and/or paternal occupational pesticide exposure around conception have been suggested to increase risk of leukemia in the offspring. With a view to providing insight in this area we pooled individual level data from 13 case-control studies participating in the Childhood Leukemia International Consortium (CLIC). Occupational data were harmonized to a compatible format. Pooled individual analyses were undertaken using unconditional logistic regression. Using exposure data from mothers of 8,236 cases, and 14,850 controls, and from fathers of 8,169 cases and 14,201 controls the odds ratio (OR) for maternal exposure during pregnancy and the risk of acute lymphoblastic leukemia (ALL) was 1.01 (95% confidence interval (CI) 0.78, 1.30) and for paternal exposure around conception 1.20 (95% 1.06, 1.38). For acute myeloid leukemia (AML), the OR for maternal exposure during pregnancy was 1.94 (CI 1.19, 3.18) and for paternal exposure around conception 0.91 (CI 0.66, 1.24.) based on data from 1,329 case and 12,141 control mothers, and 1,231 case and 11,383 control fathers. Our finding of a significantly increased risk of AML in the offspring with maternal exposure to pesticides during pregnancy is consistent with previous reports. We also found a slight increase in risk of ALL with paternal exposure around conception which appeared to be more evident in children diagnosed at the age of five years or more and those with T cell ALL which raises interesting questions on possible mechanisms. PMID:24700406

When less is more: the consequences of affective primacy for subliminal priming effects.

PubMed

Stapel, Diederik A; Koomen, Willem

2005-09-01

This research investigates the consequences of the notion that one can distinguish early-evaluative (when exposure is short) and late-descriptive reactions (when exposure is long) to subliminally primed trait concepts. In three studies, it was found that the evaluative effects instigated by short exposure to primed concepts were bigger than the evaluative + descriptive effects instigated by long exposure: Less is more. Only when exposure was short, target interpretations were accompanied by evaluative inferences (Studies 1 and 3). Similarly, only when exposure was short, descriptively inapplicable trait primes affected the interpretation of an ambiguous target (Studies 2 and 3).

[Complexity of care: meanings and interpretation].

PubMed

Cologna, Marina; Zanolli, Daniela; Saiani, Luisa

2010-01-01

Although the concept of complexity of care is widely used and discussed, its meaning is blurred and its characteristics are not well defined. To identify the words used to define the concept of complexity in the literature and its meaning. A literature search was performed on the following databases: Pubmed, Medline, Ebsco, Cinahl and Cochrane. No temporal limits were set; publications written in English and Italian were included. Several terms are used to define the concept of complexity, often interchangeably notwithstanding their different meaning. Three main concepts were identified: nursing intensity that includes the concepts of dependency, severity and complexity of patients care; nursing workload that comprises the concept of nursing intensity and all the activities not patient-related; and the patient acuity that includes the severity of illness and the caring intensity. A common definition is needed to be able to use the concept of complexity of care to allocate nursing resources.

New solutions to realize complex optical systems by a combination of diffractive and refractive optical components

NASA Astrophysics Data System (ADS)

Brunner, Robert; Steiner, Reinhard; Dobschal, Hans-Juergen; Martin, Dietrich; Burkhardt, Matthias; Helgert, Michael

2003-11-01

Diffractive optical elements (DOEs) have a great potential in the complete or partial substitution of refractive or reflective optical elements in imaging systems. The greater design flexibility compared to an all-refractive/reflective solution allows a more convenient realization of the optical systems and additionally opens up new possibilities for optimizing the performance or compactness. To demonstrate the opportunities of the hybrid optical concept we discuss different imaging systems for various applications. We present the lens design of a hybrid microscope objective which is especially applicable for wafer inspection technologies. Meeting the requirements for such a system used in the deep-UV regime (248 nm) is very challenging. The short wavelength limits the material selection and demands cement free optical groups. The additional requirement of an autofocus system, working at a wavelength in the near infrared region, is fulfilled by the special combination of two selected and adjusted DOEs. Furthermore, we discuss the opportunities of the hybrid concept c of a slit lamp used for ophthalmologic examinations. The DOEs are the basic elements of this hybrid concept. We demonstrate that holographic lithography is an appropriate technology to realize a wide variety of elements with different profile geometries. We address in particular the additional possibilities of an UV-laser system as an exposure tool. Additionally to the high spatial frequencies, the 266 nm exposure wavelength allows the use of novel photo resists with advantageous development behavior.

A multimodal imaging workflow to visualize metal mixtures in the human placenta and explore colocalization with biological response markers.

PubMed

Niedzwiecki, Megan M; Austin, Christine; Remark, Romain; Merad, Miriam; Gnjatic, Sacha; Estrada-Gutierrez, Guadalupe; Espejel-Nuñez, Aurora; Borboa-Olivares, Hector; Guzman-Huerta, Mario; Wright, Rosalind J; Wright, Robert O; Arora, Manish

2016-04-01

Fetal exposure to essential and toxic metals can influence life-long health trajectories. The placenta regulates chemical transmission from maternal circulation to the fetus and itself exhibits a complex response to environmental stressors. The placenta can thus be a useful matrix to monitor metal exposures and stress responses in utero, but strategies to explore the biologic effects of metal mixtures in this organ are not well-developed. In this proof-of-concept study, we used laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) to measure the distributions of multiple metals in placental tissue from a low-birth-weight pregnancy, and we developed an approach to identify the components of metal mixtures that colocalized with biological response markers. Our novel workflow, which includes custom-developed software tools and algorithms for spatial outlier identification and background subtraction in multidimensional elemental image stacks, enables rapid image processing and seamless integration of data from elemental imaging and immunohistochemistry. Using quantitative spatial statistics, we identified distinct patterns of metal accumulation at sites of inflammation. Broadly, our multiplexed approach can be used to explore the mechanisms mediating complex metal exposures and biologic responses within placentae and other tissue types. Our LA-ICP-MS image processing workflow can be accessed through our interactive R Shiny application 'shinyImaging', which is available at or through our laboratory's website, .

The role of building models in the evaluation of heat-related risks

NASA Astrophysics Data System (ADS)

Buchin, Oliver; Jänicke, Britta; Meier, Fred; Scherer, Dieter; Ziegler, Felix

2016-04-01

Hazard-risk relationships in epidemiological studies are generally based on the outdoor climate, despite the fact that most of humans' lifetime is spent indoors. By coupling indoor and outdoor climates with a building model, the risk concept developed can still be based on the outdoor conditions but also includes exposure to the indoor climate. The influence of non-linear building physics and the impact of air conditioning on heat-related risks can be assessed in a plausible manner using this risk concept. For proof of concept, the proposed risk concept is compared to a traditional risk analysis. As an example, daily and city-wide mortality data of the age group 65 and older in Berlin, Germany, for the years 2001-2010 are used. Four building models with differing complexity are applied in a time-series regression analysis. This study shows that indoor hazard better explains the variability in the risk data compared to outdoor hazard, depending on the kind of building model. Simplified parameter models include the main non-linear effects and are proposed for the time-series analysis. The concept shows that the definitions of heat events, lag days, and acclimatization in a traditional hazard-risk relationship are influenced by the characteristics of the prevailing building stock.

Third Conference on Fibrous Composites in Flight Vehicle Design, part 1

NASA Technical Reports Server (NTRS)

1976-01-01

The use of fibrous composite materials in the design of aircraft and space vehicle structures and their impact on future vehicle systems are discussed. The topics covered include: flight test work on composite components, design concepts and hardware, specialized applications, operational experience, certification and design criteria. Contributions to the design technology base include data concerning material properties, design procedures, environmental exposure effects, manufacturing procedures, and flight service reliability. By including composites as baseline design materials, significant payoffs are expected in terms of reduced structural weight fractions, longer structural life, reduced fuel consumption, reduced structural complexity, and reduced manufacturing cost.

[Showing skin (or not) on the hot Tunisian sand: an impossible version of Sea, Sex and Sun?].

PubMed

Héas, Stéphane; Héas, Corinne

2011-01-01

Beaches are places where human behavior is highly codified. The revealing or on the contrary concealing of one's body responds to complex cultural imperatives. Exposure of skin is never trivial, or harmless from a health point of view, and it always has repercussions in terms of social relations. This article is based on direct observations over several years in a small coastal town in Tunisia. The presentation of the body is described in particular with regard to the wearing of veils and in terms of relationships between men and women. Contact with water or sand and sun exposure play a role in the system of exchange of gestures observed. The strategies they use are presented in terms of the concept of social pollution and according to the beaches that distinguish between the different types of beachgoers.

Large prospective birth cohort studies on environmental contaminants and child health - goals, challenges, limitations and needs.

PubMed

Luo, Zhong-Cheng; Liu, Jian-Meng; Fraser, William D

2010-02-01

The adverse health effects of environmental contaminants (ECs) are a rising public health concern, and a major threat to sustainable socioeconomic development. The developing fetuses and growing children are particularly vulnerable to the adverse effects of ECs. However, assessing the health impact of ECs presents a major challenge, given that multiple outcomes may arise from one exposure, multiple exposures may result in one outcome, and the complex interactions between ECs, and between ECs, nutrients and genetic factors, and the dynamic temporal changes in EC exposures during the life course. Large-scale prospective birth cohort studies collecting extensive data and specimen starting from the prenatal or pre-conception period, although costly, hold promise as a means to more clearly quantify the health effects of ECs, and to unravel the complex interactions between ECs, nutrients and genotypes. A number of such large-scale studies have been launched in some developed counties. We present an overview of "why", "what" and "how" behind these efforts with an objective to uncover major unidentified limitations and needs. Three major limitations were identified: (1) limited data and bio-specimens regarding early life EC exposure assessments in some birth cohort studies; (2) heavy participant burdens in some birth cohort studies may bias participant recruitment, and risk substantial loss to follow-up, protocol deviations limiting the quality of data and specimens collection, with an overall potential bias towards the null effect; (3) lack of concerted efforts in building comparable birth cohorts across countries to take advantage of natural "experiments" (large EC exposure level differences between countries) for more in-depth assessments of dose-response relationships, threshold exposure levels, and positive and negative effect modifiers. Addressing these concerns in current or future large-scale birth cohort studies may help to produce better evidence on the health effects of ECs.

Prenatal exposure of a girl with autism spectrum disorder to 'horsetail' (Equisetum arvense) herbal remedy and alcohol: a case report

PubMed Central

2011-01-01

Introduction Autism is a complex neurodevelopmental disorder in which the interactions of genetic, epigenetic and environmental influences are thought to play a causal role. In humans, throughout embryonic and fetal life, brain development is exquisitely susceptible to injury caused by exposure to toxic chemicals present in the environment. Although the use of herbal supplements during pregnancy is relatively common, little information is available on their association with fetal neurodevelopment. This is, to the best of our knowledge, the first report in the literature to associate a new plausible mechanism of neurodevelopmental toxicity with a case of autism spectrum disorder through a vitamin deficiency potentiated by concomitant use of herbal supplements and ethanol exposure. Case presentation We describe the pediatric environmental history of a three-year-old Caucasian girl with an autism spectrum disorder. We utilized her pediatric environmental history to evaluate constitutional, genetic, and environmental factors pertinent to manifestation of neurodevelopment disorders. Both parents reported prenatal exposure to several risk factors of interest. A year prior to conception the mother began a weight loss diet and ingested 1200 mg/day of 'horsetail' (Equisetum arvense) herbal remedies containing thiaminase, an enzyme that with long-term use can lead to vitamin deficiency. The mother reported a significant weight loss during the pregnancy and a deficiency of B-complex vitamins. Thiamine (vitamin B1) deficiency could have been potentiated by the horsetail's thiaminase activity and ethanol exposure during pregnancy. No other risk factors were identified. Conclusions A detailed and careful pediatric environmental history, which includes daily intake, herbal remedies and ethanol exposure, should be obtained from all patients with autism spectrum disorder. Maternal consumption of ethanol and of herbal supplements with suspected or potential toxicity should be avoided during pregnancy. The prospective parents should perform preconception planning before pregnancy. PMID:21453474

Measurement Error Correction for Predicted Spatiotemporal Air Pollution Exposures.

PubMed

Keller, Joshua P; Chang, Howard H; Strickland, Matthew J; Szpiro, Adam A

2017-05-01

Air pollution cohort studies are frequently analyzed in two stages, first modeling exposure then using predicted exposures to estimate health effects in a second regression model. The difference between predicted and unobserved true exposures introduces a form of measurement error in the second stage health model. Recent methods for spatial data correct for measurement error with a bootstrap and by requiring the study design ensure spatial compatibility, that is, monitor and subject locations are drawn from the same spatial distribution. These methods have not previously been applied to spatiotemporal exposure data. We analyzed the association between fine particulate matter (PM2.5) and birth weight in the US state of Georgia using records with estimated date of conception during 2002-2005 (n = 403,881). We predicted trimester-specific PM2.5 exposure using a complex spatiotemporal exposure model. To improve spatial compatibility, we restricted to mothers residing in counties with a PM2.5 monitor (n = 180,440). We accounted for additional measurement error via a nonparametric bootstrap. Third trimester PM2.5 exposure was associated with lower birth weight in the uncorrected (-2.4 g per 1 μg/m difference in exposure; 95% confidence interval [CI]: -3.9, -0.8) and bootstrap-corrected (-2.5 g, 95% CI: -4.2, -0.8) analyses. Results for the unrestricted analysis were attenuated (-0.66 g, 95% CI: -1.7, 0.35). This study presents a novel application of measurement error correction for spatiotemporal air pollution exposures. Our results demonstrate the importance of spatial compatibility between monitor and subject locations and provide evidence of the association between air pollution exposure and birth weight.

Concepts of risk assesment of complex chemical mixtures in laser pyrolysis fumes

NASA Astrophysics Data System (ADS)

Weber, Lothar W.; Meier, Thomas H.

1996-01-01

Laser-tissue interaction may generate by energy absorption a complex mixture of gaseous, volatile, semi-volatile and particular substances. At the time about 150 different components are known from IR-laser interaction with different organ tissues like liver, fat, muscle and skin. The laser-tissue interaction process thereby is dominated by heating processes, which is confirmed by the similarity of formed chemical products in comparison with conventional cooking processes for food preparation. With the identified chemical substances and relative amounts in backmind a walk along the think path of risk assessment with special reference to pyrolysis products is given. The main way of intake of pyrolysis products is the inhalative one, which results from the fine aerosols formed and the high spreading energy out of the irradiated source. The liberated amounts of irritative chemicals as (unsaturated) aldehydes, heterocycles of bad odor and possibly cancerogenic acting substances relates to some (mu) g/g of laser vaporized tissue. With regard to this exposure level in a hypothetic one cubic meter volume the occupational limit settings are far away. Even indoor air exposure levels are in nearly all cases underwent, for the content of bad smelling substances forces an effective ventilation. Up to now no laser typical chemical substance could be identified, which was not elsewhere known by frying or baking processes of meat, food or familiar. Starting with the GRAS concept of 1957 the process of risk assessment by modified food products and new ingredients is still improofing. The same process of risk assessment is governing the laser pyrolysis products of mammalian tissues. By use of sufficient suction around the laser tissue source the odor problems as well as the toxicological problems could be solved.

The Concept of Equivalent Radon Concentration for Practical Consideration of Indoor Exposure to Thoron

PubMed Central

Chen, Jing; Moir, Deborah

2012-01-01

To consider the total exposure to indoor radon and thoron, a concept of equivalent radon concentration for thoron is introduced, defined as the radon concentration that delivers the same annual effective dose as that resulting from the thoron concentration. The total indoor exposure to radon and thoron is then the sum of the radon concentration and the equivalent radon concentration for thoron. The total exposure should be compared to the radon guideline value, and if it exceeds the guideline value, appropriate remedial action is required. With this concept, a separate guideline for indoor thoron exposure is not necessary. For homes already tested for radon with radon detectors, Health Canada’s recommendation of a 3-month radon test performed during the fall/winter heating season not only ensures a conservative estimate of the annual average radon concentration but also covers well any potentially missing contribution from thoron exposure. In addition, because the thoron concentration is much lower than the radon concentration in most homes in Canada, there is no real need to re-test homes for thoron. PMID:22470292

Reconstructive microsurgery of the female reproductive tract using a CO 2 laser

NASA Astrophysics Data System (ADS)

Bellina, J. H.

1982-04-01

Laser tubal microsurgery was carried out on a sample of 82 patients. Employing current laser surgical systems, 21 conceptions occured in 20 patients, after limited exposure to conception risk during the 13-month study. This represents 48% of the 42 patients at risk. Tubal patency was demonstrated in 94% of the 82 cases. Based upon experience to date, more conceptions are expected as more patients become at risk and as exposure increases.

The complex patient: A concept clarification.

PubMed

Manning, Eli; Gagnon, Marilou

2017-03-01

Over the last decade, the concept of the "complex patient" has not only been more widely used in multidisciplinary healthcare teams and across various healthcare disciplines, but it has also become more vacuous in meaning. The uptake of the concept of the "complex patient" spans across disciplines, such as medicine, nursing, and social work, with no consistent definition. We review the chronological evolution of this concept and its surrogate terms, namely "comorbidity," "multimorbidity," "polypathology," "dual diagnosis," and "multiple chronic conditions." Drawing on key principles of concept clarification, we highlight disciplinary usage in the literature published between 2005 and 2015 in health sciences, attending to overlaps and revealing nuances of the complex patient concept. Finally, we discuss the implications of this concept for practice, research, and theory. © 2017 John Wiley & Sons Australia, Ltd.

The human early-life exposome (HELIX): project rationale and design.

PubMed

Vrijheid, Martine; Slama, Rémy; Robinson, Oliver; Chatzi, Leda; Coen, Muireann; van den Hazel, Peter; Thomsen, Cathrine; Wright, John; Athersuch, Toby J; Avellana, Narcis; Basagaña, Xavier; Brochot, Celine; Bucchini, Luca; Bustamante, Mariona; Carracedo, Angel; Casas, Maribel; Estivill, Xavier; Fairley, Lesley; van Gent, Diana; Gonzalez, Juan R; Granum, Berit; Gražulevičienė, Regina; Gutzkow, Kristine B; Julvez, Jordi; Keun, Hector C; Kogevinas, Manolis; McEachan, Rosemary R C; Meltzer, Helle Margrete; Sabidó, Eduard; Schwarze, Per E; Siroux, Valérie; Sunyer, Jordi; Want, Elizabeth J; Zeman, Florence; Nieuwenhuijsen, Mark J

2014-06-01

Developmental periods in early life may be particularly vulnerable to impacts of environmental exposures. Human research on this topic has generally focused on single exposure-health effect relationships. The "exposome" concept encompasses the totality of exposures from conception onward, complementing the genome. The Human Early-Life Exposome (HELIX) project is a new collaborative research project that aims to implement novel exposure assessment and biomarker methods to characterize early-life exposure to multiple environmental factors and associate these with omics biomarkers and child health outcomes, thus characterizing the "early-life exposome." Here we describe the general design of the project. In six existing birth cohort studies in Europe, HELIX will estimate prenatal and postnatal exposure to a broad range of chemical and physical exposures. Exposure models will be developed for the full cohorts totaling 32,000 mother-child pairs, and biomarkers will be measured in a subset of 1,200 mother-child pairs. Nested repeat-sampling panel studies (n = 150) will collect data on biomarker variability, use smartphones to assess mobility and physical activity, and perform personal exposure monitoring. Omics techniques will determine molecular profiles (metabolome, proteome, transcriptome, epigenome) associated with exposures. Statistical methods for multiple exposures will provide exposure-response estimates for fetal and child growth, obesity, neurodevelopment, and respiratory outcomes. A health impact assessment exercise will evaluate risks and benefits of combined exposures. HELIX is one of the first attempts to describe the early-life exposome of European populations and unravel its relation to omics markers and health in childhood. As proof of concept, it will form an important first step toward the life-course exposome.

OSL surface exposure dating of wave-emplaced coastal boulders - Research concept and first results from the Rabat coast, Morocco

NASA Astrophysics Data System (ADS)

Brill, Dominik; May, Simon Matthias; Mhammdi, Nadia; King, Georgina; Brückner, Helmut

2017-04-01

Fields of wave-emplaced blocks and boulders represent impressive evidence of cyclone and tsunami flooding over Holocene time scales. Unfortunately, their use for coastal hazard assessment is in many cases impeded by the absence of appropriate dating approaches, which are needed to generate robust chronologies. The commonly applied AMS-14C, U/Th or ESR dating of coral-reef rocks and marine organisms attached to the clasts depends on a - mostly hypothetical - coincidence between the organisms' death and boulder displacement, and inferred event chronologies may be biased by the marine 14C-reservoir effect and reworked organisms. Here we discuss the potential of the recently developed optically stimulated luminescence (OSL) surface exposure dating technique to directly date the relocation process of wave-emplaced boulders. By measuring the depth-dependent resetting of luminescence signals in exposed rock surfaces and comparing it to the signal-depth profiles of known-age samples, OSL surface exposure dating may be capable to model direct depositional ages for boulder transport. Thereby, it promises to overcome the limitations of existing dating techniques, and to decipher complex transport histories of clasts that underwent multiple phases of exposure and burial. The concept and some first results of OSL surface exposure dating shall be presented for coastal boulders from the Rabat coast, Morocco, where the preconditions for successful dating are promising: (i) Several coastal boulders show clear indication of overturning during wave transport in the form of downward-facing bio-eroded surfaces; (ii) the boulders are composed of different types of sandstone that contain quartz and feldspar, the required dosimeters for OSL dating; (iii) all boulders are of Holocene age and, therefore, in the dating range of OSL surface exposure dating. The main challenges for a successful application are the intensive bio-erosion and weathering of some surfaces exposed after transport, and the need for method calibration using surfaces with similar lithology and known exposure ages. However, in the best case, OSL surface exposure dating will provide quantitative information about the frequency-magnitude relationship of extreme wave events at the Rabat coast, in particular determining whether severe tsunami-induced flooding can be expected (e.g. during the 1755 Lisbon tsunami and similar events), or if boulders were only moved during flooding by exceptional winter storms.

Contributions of Music Video Exposure to Black Adolescents' Gender and Sexual Schemas

ERIC Educational Resources Information Center

Ward, L. Monique; Hansbrough, Edwina; Walker, Eboni

2005-01-01

Although music videos feature prominently in the media diets of many adolescents, little is known of their impact on viewers' conceptions of femininity and masculinity. Accordingly, this study examines the impact of both regular and experimental music video exposure on adolescent viewers' conceptions about gender. Across two testing sessions, 152…

75 FR 58387 - Notice of Issuance of Exposure Draft of a Concepts Statement on Measurement of the Elements of...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-24

... FEDERAL ACCOUNTING STANDARDS ADVISORY BOARD Notice of Issuance of Exposure Draft of a Concepts Statement on Measurement of the Elements of Accrual-Basis Financial Statements in Periods After Initial Recording AGENCY: Federal Accounting Standards Advisory Board. ACTION: Notice. Board Action: Pursuant to 31...

Issues and approaches for ensuring effective communication on acceptable daily exposure (ADE) values applied to pharmaceutical cleaning.

PubMed

Olson, Michael J; Faria, Ellen C; Hayes, Eileen P; Jolly, Robert A; Barle, Ester Lovsin; Molnar, Lance R; Naumann, Bruce D; Pecquet, Alison M; Shipp, Bryan K; Sussman, Robert G; Weideman, Patricia A

2016-08-01

This manuscript centers on communication with key stakeholders of the concepts and program goals involved in the application of health-based pharmaceutical cleaning limits. Implementation of health-based cleaning limits, as distinct from other standards such as 1/1000th of the lowest clinical dose, is a concept recently introduced into regulatory domains. While there is a great deal of technical detail in the written framework underpinning the use of Acceptable Daily Exposures (ADEs) in cleaning (for example ISPE, 2010; Sargent et al., 2013), little is available to explain how to practically create a program which meets regulatory needs while also fulfilling good manufacturing practice (GMP) and other expectations. The lack of a harmonized approach for program implementation and communication across stakeholders can ultimately foster inappropriate application of these concepts. Thus, this period in time (2014-2017) could be considered transitional with respect to influencing best practice related to establishing health-based cleaning limits. Suggestions offered in this manuscript are intended to encourage full and accurate communication regarding both scientific and administrative elements of health-based ADE values used in pharmaceutical cleaning practice. This is a large and complex effort that requires: 1) clearly explaining key terms and definitions, 2) identification of stakeholders, 3) assessment of stakeholders' subject matter knowledge, 4) formulation of key messages fit to stakeholder needs, 5) identification of effective and timely means for communication, and 6) allocation of time, energy, and motivation for initiating and carrying through with communications. Copyright © 2016 Elsevier Inc. All rights reserved.

Association between exposure to ambient air pollution before conception date and likelihood of giving birth to girls in Guangzhou, China

NASA Astrophysics Data System (ADS)

Lin, Hualiang; Liang, Zhijiang; Liu, Tao; Di, Qian; Qian, Zhengmin; Zeng, Weilin; Xiao, Jianpeng; Li, Xing; Guo, Lingchuan; Ma, Wenjun; Zhao, Qingguo

2015-12-01

A few studies have linked ambient air pollution with sex ratio at birth. Most of these studies examined the long-term effects using spatial or temporal comparison approaches. This study aimed to investigate whether parental exposure to air pollution before conception date could affect the likelihood of the offspring being male or female. We used the information collected in a major maternal hospital in Guangzhou, China. The parental exposure to air pollution was assessed using the air pollution concentration before the conception date. Logistic regression models were used to assess the association between air pollution exposure and birth sex with adjustment for potential confounding factors, such as maternal age, parental education levels, long-term trend, season, and weather condition (mean temperature and relative humidity). The analysis revealed that higher air pollution was associated with higher probability of female newborns, with the effective exposure around one week prior to conception date. In the one-pollutant models, PM10, SO2 and NO2 had significant effects. For example, the excess risk was 0.61% (95% confidence interval (95% CI): 0.36%, 0.86%) for a 10 ug/m3 increase in lag 2 day's PM10, 0.42% (95% CI: 0.21%, 0.64%) for lag 3 day's SO2 and 0.97% (95% CI: 0.44%, 1.50%) for lag 3 day's NO2; and in two-pollutant models, PM10 remained statistically significant. These results suggest that parental exposure to ambient air pollution a few days prior to conception might be a contributing factor to higher probability of giving birth to female offspring in Guangzhou.

Completing the Link between Exposure Science and Toxicology for Improved Environmental Health Decision Making: The Aggregate Exposure Pathway Framework.

PubMed

Teeguarden, Justin G; Tan, Yu-Mei; Edwards, Stephen W; Leonard, Jeremy A; Anderson, Kim A; Corley, Richard A; Kile, Molly L; Simonich, Staci M; Stone, David; Tanguay, Robert L; Waters, Katrina M; Harper, Stacey L; Williams, David E

2016-05-03

Driven by major scientific advances in analytical methods, biomonitoring, computation, and a newly articulated vision for a greater impact in public health, the field of exposure science is undergoing a rapid transition from a field of observation to a field of prediction. Deployment of an organizational and predictive framework for exposure science analogous to the "systems approaches" used in the biological sciences is a necessary step in this evolution. Here we propose the aggregate exposure pathway (AEP) concept as the natural and complementary companion in the exposure sciences to the adverse outcome pathway (AOP) concept in the toxicological sciences. Aggregate exposure pathways offer an intuitive framework to organize exposure data within individual units of prediction common to the field, setting the stage for exposure forecasting. Looking farther ahead, we envision direct linkages between aggregate exposure pathways and adverse outcome pathways, completing the source to outcome continuum for more meaningful integration of exposure assessment and hazard identification. Together, the two frameworks form and inform a decision-making framework with the flexibility for risk-based, hazard-based, or exposure-based decision making.

Concept Mapping as a Tool to Develop and Measure Students' Understanding in Science

ERIC Educational Resources Information Center

Tan, Sema; Erdimez, Omer; Zimmerman, Robert

2017-01-01

Concept maps measured a student's understanding of the complexity of concepts, and interrelationships. Novak and Gowin (1984) claimed that the continuous use of concept maps increased the complexity and interconnectedness of students' understanding of relationships between concepts in a particular science domain. This study has two purposes; the…

Mere Exposure to Money Increases Endorsement of Free-Market Systems and Social Inequality

ERIC Educational Resources Information Center

Caruso, Eugene M.; Vohs, Kathleen D.; Baxter, Brittani; Waytz, Adam

2013-01-01

The present research tested whether incidental exposure to money affects people's endorsement of social systems that legitimize social inequality. We found that subtle reminders of the concept of money, relative to nonmoney concepts, led participants to endorse more strongly the existing social system in the United States in general (Experiment 1)…

A survey of residents' experience with patient safety and quality improvement concepts in radiation oncology.

PubMed

Spraker, Matthew B; Nyflot, Matthew; Hendrickson, Kristi; Ford, Eric; Kane, Gabrielle; Zeng, Jing

The safety and quality of radiation therapy have recently garnered increased attention in radiation oncology (RO). Although patient safety guidelines expect physicians and physicists to lead clinical safety and quality improvement (QI) programs, trainees' level of exposure to patient safety concepts during training is unknown. We surveyed active medical and physics RO residents in North America in February 2016. Survey questions involved demographics and program characteristics, exposure to patient safety topics, and residents' attitude regarding their safety education. Responses were collected from 139 of 690 (20%) medical and 56 of 248 (23%) physics RO residents. More than 60% of residents had no exposure or only informal exposure to incident learning systems (ILS), root cause analysis, failure mode and effects analysis (FMEA), and the concepts of human factors engineering. Medical residents had less exposure to FMEA than physics residents, and fewer medical than physics residents felt confident in leading FMEA in clinic. Only 27% of residents felt that patient safety training was adequate in their program. Experiential learning through practical workshops was the most desired educational modality, preferred over web-based learning. Residents training in departments with ILS had greater exposure to patient safety concepts and felt more confident leading clinical patient safety and QI programs than residents training in departments without an ILS. The survey results show that most residents have no or only informal exposure to important patient safety and QI concepts and do not feel confident leading clinical safety programs. This represents a gaping need in RO resident education. Educational programs such as these can be naturally developed as part of an incident learning program that focuses on near-miss events. Future research should assess the needs of RO program directors to develop effective RO patient safety and QI training programs. Copyright © 2016 American Society of Radiation Oncology. Published by Elsevier Inc. All rights reserved.

Application of simplified Complexity Theory concepts for healthcare social systems to explain the implementation of evidence into practice.

PubMed

Chandler, Jacqueline; Rycroft-Malone, Jo; Hawkes, Claire; Noyes, Jane

2016-02-01

To examine the application of core concepts from Complexity Theory to explain the findings from a process evaluation undertaken in a trial evaluating implementation strategies for recommendations about reducing surgical fasting times. The proliferation of evidence-based guidance requires a greater focus on its implementation. Theory is required to explain the complex processes across the multiple healthcare organizational levels. This social healthcare context involves the interaction between professionals, patients and the organizational systems in care delivery. Complexity Theory may provide an explanatory framework to explain the complexities inherent in implementation in social healthcare contexts. A secondary thematic analysis of qualitative process evaluation data informed by Complexity Theory. Seminal texts applying Complexity Theory to the social context were annotated, key concepts extracted and core Complexity Theory concepts identified. These core concepts were applied as a theoretical lens to provide an explanation of themes from a process evaluation of a trial evaluating the implementation of strategies to reduce surgical fasting times. Sampled substantive texts provided a representative spread of theoretical development and application of Complexity Theory from late 1990's-2013 in social science, healthcare, management and philosophy. Five Complexity Theory core concepts extracted were 'self-organization', 'interaction', 'emergence', 'system history' and 'temporality'. Application of these concepts suggests routine surgical fasting practice is habituated in the social healthcare system and therefore it cannot easily be reversed. A reduction to fasting times requires an incentivised new approach to emerge in the surgical system's priority of completing the operating list. The application of Complexity Theory provides a useful explanation for resistance to change fasting practice. Its utility in implementation research warrants further attention and evaluation. © 2015 John Wiley & Sons Ltd.

The complexity of gene expression dynamics revealed by permutation entropy

PubMed Central

2010-01-01

Background High complexity is considered a hallmark of living systems. Here we investigate the complexity of temporal gene expression patterns using the concept of Permutation Entropy (PE) first introduced in dynamical systems theory. The analysis of gene expression data has so far focused primarily on the identification of differentially expressed genes, or on the elucidation of pathway and regulatory relationships. We aim to study gene expression time series data from the viewpoint of complexity. Results Applying the PE complexity metric to abiotic stress response time series data in Arabidopsis thaliana, genes involved in stress response and signaling were found to be associated with the highest complexity not only under stress, but surprisingly, also under reference, non-stress conditions. Genes with house-keeping functions exhibited lower PE complexity. Compared to reference conditions, the PE of temporal gene expression patterns generally increased upon stress exposure. High-complexity genes were found to have longer upstream intergenic regions and more cis-regulatory motifs in their promoter regions indicative of a more complex regulatory apparatus needed to orchestrate their expression, and to be associated with higher correlation network connectivity degree. Arabidopsis genes also present in other plant species were observed to exhibit decreased PE complexity compared to Arabidopsis specific genes. Conclusions We show that Permutation Entropy is a simple yet robust and powerful approach to identify temporal gene expression profiles of varying complexity that is equally applicable to other types of molecular profile data. PMID:21176199

Joined up Thinking? Evaluating the Use of Concept-Mapping to Develop Complex System Learning

ERIC Educational Resources Information Center

Stewart, Martyn

2012-01-01

In the physical and natural sciences, the complexity of natural systems and their interactions is becoming better understood. With increased emphasis on learning about complex systems, students will be encountering concepts that are dynamic, ill-structured and interconnected. Concept-mapping is a method considered particularly valuable for…

Exploring violence exposure, stress, protective factors and behavioral problems among inner-city youth.

PubMed

Youngstrom, Eric; Weist, Mark D; Albus, Kathleen E

2003-09-01

This study examined relationships between violence exposure, other stressors, family support, and self-concept on self-reported behavioral problems among 320 urban adolescents (aged 11-18) referred for mental health treatment. Overall, participants reported high levels of violence exposure, with a median of six past encounters with violence as a witness, victim, or through the experiences of associates. All forms of violence exposure (witnessing, being a victim, knowing of victims) were correlated with internalizing and externalizing behavioral problems for males and females. Total violence exposure predicted behavioral problems among participants, even after controlling for the effects of other risk, demographic and protective factors. Family support and self-concept moderated the influence of life stress and cumulative risk on problem behavior outcomes, but these protective variables did not significantly moderate violence exposure.

Complex overlapping concepts: An effective auditing methodology for families of similarly structured BioPortal ontologies.

PubMed

Zheng, Ling; Chen, Yan; Elhanan, Gai; Perl, Yehoshua; Geller, James; Ochs, Christopher

2018-05-28

In previous research, we have demonstrated for a number of ontologies that structurally complex concepts (for different definitions of "complex") in an ontology are more likely to exhibit errors than other concepts. Thus, such complex concepts often become fertile ground for quality assurance (QA) in ontologies. They should be audited first. One example of complex concepts is given by "overlapping concepts" (to be defined below.) Historically, a different auditing methodology had to be developed for every single ontology. For better scalability and efficiency, it is desirable to identify family-wide QA methodologies. Each such methodology would be applicable to a whole family of similar ontologies. In past research, we had divided the 685 ontologies of BioPortal into families of structurally similar ontologies. We showed for four ontologies of the same large family in BioPortal that "overlapping concepts" are indeed statistically significantly more likely to exhibit errors. In order to make an authoritative statement concerning the success of "overlapping concepts" as a methodology for a whole family of similar ontologies (or of large subhierarchies of ontologies), it is necessary to show that "overlapping concepts" have a higher likelihood of errors for six out of six ontologies of the family. In this paper, we are demonstrating for two more ontologies that "overlapping concepts" can successfully predict groups of concepts with a higher error rate than concepts from a control group. The fifth ontology is the Neoplasm subhierarchy of the National Cancer Institute thesaurus (NCIt). The sixth ontology is the Infectious Disease subhierarchy of SNOMED CT. We demonstrate quality assurance results for both of them. Furthermore, in this paper we observe two novel, important, and useful phenomena during quality assurance of "overlapping concepts." First, an erroneous "overlapping concept" can help with discovering other erroneous "non-overlapping concepts" in its vicinity. Secondly, correcting erroneous "overlapping concepts" may turn them into "non-overlapping concepts." We demonstrate that this may reduce the complexity of parts of the ontology, which in turn makes the ontology more comprehensible, simplifying maintenance and use of the ontology. Copyright © 2018. Published by Elsevier Inc.

The Importance of Adolescents' Sexually Outgoing Self-Concept: Differential Roles of Self- and Other-Generated Sexy Self-Presentations in Social Media.

PubMed

van Oosten, Johanna M F; de Vries, Dian A; Peter, Jochen

2018-01-01

The present study investigated the relationships between (exposure to) sexy self-presentations on social network sites (SNSs) and adolescents' sexual self-concept over time. Results from a three-wave panel study among 1,288 Dutch adolescents (aged 13-17 years) showed that more frequent engagement in sexy self-presentation, rather than exposure to sexy self-presentations of others, on SNSs positively predicted the importance of being sexually outgoing (e.g., sexy, seductive, and wild) in adolescents' self-concept 6 months later.

Dynamic equilibrium behaviour observed on two contrasting tidal flats from daily monitoring of bed-level changes

NASA Astrophysics Data System (ADS)

Hu, Zhan; van der Wal, Daphne; Cai, Huayang; van Belzen, Jim; Bouma, Tjeerd J.

2018-06-01

Dynamic equilibrium theory (DET) has been applied to tidal flats to systematically explain intertidal morphological responses to various distributions of bed shear stress (BSS). However, it is difficult to verify this theory with field observations because of the discrepancy between the idealized conceptions of theory and the complex reality of intertidal dynamics. The core relation between intertidal morphodynamics and BSS distribution can be easily masked by noise in complex datasets, leading to conclusions of insufficient field evidence to support DET. In the current study, hydrodynamic and morphodynamic data were monitored daily for one year on two tidal flats with contrasting wave exposures. BSS distribution was obtained by validated numerical models. Tidal flat dynamic equilibrium behaviour and BSS were linked via Empirical Orthogonal Function (EOF) analysis. We show that the principal morphodynamic modes corresponded well with the respective modes of BSS found at both sites. Tide-induced BSS was the dominant force at both sites, regardless of the level of wave exposure. The overall erosional and steepening trend found at the two flats can be attributed to the prevailing action of tidal forcing and reduced sediment supply. Hence, EOF analysis confirmed that tidal flat morphodynamics are consistent with DET, providing both field and model evidence to support this theory.

The Role of Sociability Self-Concept in the Relationship between Exposure to and Concern about Aggression in Middle School

ERIC Educational Resources Information Center

Miller, Janice Williams

2013-01-01

This study examined middle grades students' sociability self-concept and their perceptions about feeling safe at school. Participants' (N = 420) exposure to school aggression and concern about the potential for violence at school were measured across four critical areas: fighting, bullying, stealing, and seeing weapons. Results indicated a limited…

Concept Mapping: A Graphical System for Understanding the Relationship between Concepts. ERIC Digest.

ERIC Educational Resources Information Center

Plotnick, Eric

This ERIC Digest discusses concept mapping, a technique for representing the structure of information visually. Concept mapping can be used to brainstorm, design complex structures, communicate complex ideas, aid learning by explicitly integrating new and old knowledge, and assess understanding or diagnose misunderstanding. Visual representation…

Biologically-Inspired Concepts for Self-Management of Complexity

NASA Technical Reports Server (NTRS)

Sterritt, Roy; Hinchey, G.

2006-01-01

Inherent complexity in large-scale applications may be impossible to eliminate or even ameliorate despite a number of promising advances. In such cases, the complexity must be tolerated and managed. Such management may be beyond the abilities of humans, or require such overhead as to make management by humans unrealistic. A number of initiatives inspired by concepts in biology have arisen for self-management of complex systems. We present some ideas and techniques we have been experimenting with, inspired by lesser-known concepts in biology that show promise in protecting complex systems and represent a step towards self-management of complexity.

HUMAN EXPOSURE MODELING: CONCEPTS, METHODS, AND TOOLS

EPA Science Inventory

Understanding human exposure is critical when estimating the occurrence of deleterious effects that could follow contact with environmental contaminants. For many pollutants, the intensity, duration, frequency, route, and timing of exposure is highly variable, particularly whe...

Stress model for research into preterm delivery among black women.

PubMed

Hogue, Carol J Rowland; Bremner, J Douglas

2005-05-01

The disparity between black and white infant mortality rates increased over the last decade, despite overall improvement in infant survival. Because most black infant deaths are related to preterm delivery, the discovery of the cause of premature birth in general and excess premature birth for black infants in particular is of paramount importance for reproductive health research. Substantial theoretic support exists for maternal stress as a risk factor for preterm birth. Traumatic events early in life may sensitize the adult to contemporary stresses and increase her vulnerability to stress-induced neuroendocrine or infection/inflammatory pathways to early parturition. In addition, an individual may prematurely age as a result of cumulative stress or a major traumatic event. This "stress age," which is synonymous with the concept of weathering and similar to the concept of allostatic load, may affect parturition through chronic conditions (such as hypertension) and in poorly understood pathophysiologic mechanisms that are related to increased chronologic age. One potential measure of stress age is maternal serum dehydroepiandrosterone sulfate. Maternal stress is a potential explanatory factor for excess preterm delivery among black women because of their exposure to racism-associated stress. However, few studies have addressed this question, and results are mixed. Future etiologic research must take into account the complexities of the measurement of stress age and past and current exposures to stress, which includes internalized racism and interpersonal racism.

Auditing complex concepts of SNOMED using a refined hierarchical abstraction network.

PubMed

Wang, Yue; Halper, Michael; Wei, Duo; Gu, Huanying; Perl, Yehoshua; Xu, Junchuan; Elhanan, Gai; Chen, Yan; Spackman, Kent A; Case, James T; Hripcsak, George

2012-02-01

Auditors of a large terminology, such as SNOMED CT, face a daunting challenge. To aid them in their efforts, it is essential to devise techniques that can automatically identify concepts warranting special attention. "Complex" concepts, which by their very nature are more difficult to model, fall neatly into this category. A special kind of grouping, called a partial-area, is utilized in the characterization of complex concepts. In particular, the complex concepts that are the focus of this work are those appearing in intersections of multiple partial-areas and are thus referred to as overlapping concepts. In a companion paper, an automatic methodology for identifying and partitioning the entire collection of overlapping concepts into disjoint, singly-rooted groups, that are more manageable to work with and comprehend, has been presented. The partitioning methodology formed the foundation for the development of an abstraction network for the overlapping concepts called a disjoint partial-area taxonomy. This new disjoint partial-area taxonomy offers a collection of semantically uniform partial-areas and is exploited herein as the basis for a novel auditing methodology. The review of the overlapping concepts is done in a top-down order within semantically uniform groups. These groups are themselves reviewed in a top-down order, which proceeds from the less complex to the more complex overlapping concepts. The results of applying the methodology to SNOMED's Specimen hierarchy are presented. Hypotheses regarding error ratios for overlapping concepts and between different kinds of overlapping concepts are formulated. Two phases of auditing the Specimen hierarchy for two releases of SNOMED are reported on. With the use of the double bootstrap and Fisher's exact test (two-tailed), the auditing of concepts and especially roots of overlapping partial-areas is shown to yield a statistically significant higher proportion of errors. Copyright © 2011 Elsevier Inc. All rights reserved.

Complex adaptive systems and their relevance for nursing: An evolutionary concept analysis.

PubMed

Notarnicola, Ippolito; Petrucci, Cristina; De Jesus Barbosa, Maria Rosimar; Giorgi, Fabio; Stievano, Alessandro; Rocco, Gennaro; Lancia, Loreto

2017-06-01

This study aimed to analyse the concept of "complex adaptive systems." The construct is still nebulous in the literature, and a further explanation of the idea is needed to have a shared knowledge of it. A concept analysis was conducted utilizing Rodgers evolutionary method. The inclusive years of bibliographic search started from 2005 to 2015. The search was conducted at PubMed©, CINAHL© (EBSCO host©), Scopus©, Web of Science©, and Academic Search Premier©. Retrieved papers were critically analysed to explore the attributes, antecedents, and consequences of the concept. Moreover, surrogates, related terms, and a pattern recognition scheme were identified. The concept analysis showed that complex systems are adaptive and have the ability to process information. They can adapt to the environment and consequently evolve. Nursing is a complex adaptive system, and the nursing profession in practice exhibits complex adaptive system characteristics. Complexity science through complex adaptive systems provides new ways of seeing and understanding the mechanisms that underpin the nursing profession. © 2017 John Wiley & Sons Australia, Ltd.

Completing the Link between Exposure Science and Toxicology for Improved Environmental Health Decision Making: The Aggregate Exposure Pathway Framework

PubMed Central

Teeguarden, Justin. G.; Tan, Yu-Mei; Edwards, Stephen W.; Leonard, Jeremy A.; Anderson, Kim A.; Corley, Richard A.; Harding, Anna K; Kile, Molly L.; Simonich, Staci M; Stone, David; Tanguay, Robert L.; Waters, Katrina M.; Harper, Stacey L.; Williams, David E.

2016-01-01

Synopsis Driven by major scientific advances in analytical methods, biomonitoring, computational tools, and a newly articulated vision for a greater impact in public health, the field of exposure science is undergoing a rapid transition from a field of observation to a field of prediction. Deployment of an organizational and predictive framework for exposure science analogous to the “systems approaches” used in the biological sciences is a necessary step in this evolution. Here we propose the Aggregate Exposure Pathway (AEP) concept as the natural and complementary companion in the exposure sciences to the Adverse Outcome Pathway (AOP) concept in the toxicological sciences. Aggregate exposure pathways offer an intuitive framework to organize exposure data within individual units of prediction common to the field, setting the stage for exposure forecasting. Looking farther ahead, we envision direct linkages between aggregate exposure pathways and adverse outcome pathways, completing the source to outcome continuum for more efficient integration of exposure assessment and hazard identification. Together, the two pathways form and inform a decision-making framework with the flexibility for risk-based, hazard-based, or exposure-based decision making. PMID:26759916

Completing the link between exposure science and toxicology for improved environmental health decision making: The aggregate exposure pathway framework

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

Teeguarden, Justin G.; Tan, Yu -Mei; Edwards, Stephen W.

Here, driven by major scientific advances in analytical methods, biomonitoring, computation, and a newly articulated vision for a greater impact in public health, the field of exposure science is undergoing a rapid transition from a field of observation to a field of prediction. Deployment of an organizational and predictive framework for exposure science analogous to the “systems approaches” used in the biological sciences is a necessary step in this evolution. Here we propose the aggregate exposure pathway (AEP) concept as the natural and complementary companion in the exposure sciences to the adverse outcome pathway (AOP) concept in the toxicological sciences.more » Aggregate exposure pathways offer an intuitive framework to organize exposure data within individual units of prediction common to the field, setting the stage for exposure forecasting. Looking farther ahead, we envision direct linkages between aggregate exposure pathways and adverse outcome pathways, completing the source to outcome continuum for more meaningful integration of exposure assessment and hazard identification. Together, the two frameworks form and inform a decision-making framework with the flexibility for risk-based, hazard-based, or exposure-based decision making.« less

Completing the link between exposure science and toxicology for improved environmental health decision making: The aggregate exposure pathway framework

DOE PAGES

Teeguarden, Justin G.; Tan, Yu -Mei; Edwards, Stephen W.; ...

2016-01-13

Here, driven by major scientific advances in analytical methods, biomonitoring, computation, and a newly articulated vision for a greater impact in public health, the field of exposure science is undergoing a rapid transition from a field of observation to a field of prediction. Deployment of an organizational and predictive framework for exposure science analogous to the “systems approaches” used in the biological sciences is a necessary step in this evolution. Here we propose the aggregate exposure pathway (AEP) concept as the natural and complementary companion in the exposure sciences to the adverse outcome pathway (AOP) concept in the toxicological sciences.more » Aggregate exposure pathways offer an intuitive framework to organize exposure data within individual units of prediction common to the field, setting the stage for exposure forecasting. Looking farther ahead, we envision direct linkages between aggregate exposure pathways and adverse outcome pathways, completing the source to outcome continuum for more meaningful integration of exposure assessment and hazard identification. Together, the two frameworks form and inform a decision-making framework with the flexibility for risk-based, hazard-based, or exposure-based decision making.« less

Influence of worklife on public health.

PubMed

Aronsson, G

1999-12-01

The paper discusses worklife changes with broad public health impacts. Central concepts for the analysis of the labor market are flexibility and differentiation. One conclusion is that there is ongoing polarization and differentiation--with an increased group of people in time-restricted (contingent) employment and self-employment and a reduced group of core workers. Greater demands for adaptability are being imposed on the majority of employees. Concepts related to flexibility and differentiation at an individual level are adaptability, identity formation, loss of control, trust and lack of trust, allostatic load, long-term strain, and psychological contracting. The labor market and organizational changes are discussed in relation to what can be called "institutional effectiveness". These changes refer to how institutions commissioned to act for the prevention of injuries and to contribute to worklife quality handle the new conditions. Finally, work-environment research is discussed in relation to a new and more complex pattern of exposures and interactions. One conclusion drawn is that it is becoming increasingly difficult to identify workplaces at risk.

Mendelian Randomization.

PubMed

Grover, Sandeep; Del Greco M, Fabiola; Stein, Catherine M; Ziegler, Andreas

2017-01-01

Confounding and reverse causality have prevented us from drawing meaningful clinical interpretation even in well-powered observational studies. Confounding may be attributed to our inability to randomize the exposure variable in observational studies. Mendelian randomization (MR) is one approach to overcome confounding. It utilizes one or more genetic polymorphisms as a proxy for the exposure variable of interest. Polymorphisms are randomly distributed in a population, they are static throughout an individual's lifetime, and may thus help in inferring directionality in exposure-outcome associations. Genome-wide association studies (GWAS) or meta-analyses of GWAS are characterized by large sample sizes and the availability of many single nucleotide polymorphisms (SNPs), making GWAS-based MR an attractive approach. GWAS-based MR comes with specific challenges, including multiple causality. Despite shortcomings, it still remains one of the most powerful techniques for inferring causality.With MR still an evolving concept with complex statistical challenges, the literature is relatively scarce in terms of providing working examples incorporating real datasets. In this chapter, we provide a step-by-step guide for causal inference based on the principles of MR with a real dataset using both individual and summary data from unrelated individuals. We suggest best possible practices and give recommendations based on the current literature.

Refining the aggregate exposure pathway.

PubMed

Tan, Yu-Mei; Leonard, Jeremy A; Edwards, Stephen; Teeguarden, Justin; Egeghy, Peter

2018-03-01

Advancements in measurement technologies and modeling capabilities continue to result in an abundance of exposure information, adding to that currently in existence. However, fragmentation within the exposure science community acts as an obstacle for realizing the vision set forth in the National Research Council's report on Exposure Science in the 21 st century to consider exposures from source to dose, on multiple levels of integration, and to multiple stressors. The concept of an Aggregate Exposure Pathway (AEP) was proposed as a framework for organizing and integrating diverse exposure information that exists across numerous repositories and among multiple scientific fields. A workshop held in May 2016 followed introduction of the AEP concept, allowing members of the exposure science community to provide extensive evaluation and feedback regarding the framework's structure, key components, and applications. The current work briefly introduces topics discussed at the workshop and attempts to address key challenges involved in refining this framework. The resulting evolution in the AEP framework's features allows for facilitating acquisition, integration, organization, and transparent application and communication of exposure knowledge in a manner that is independent of its ultimate use, thereby enabling reuse of such information in many applications.

Stakeholder attitudes towards cumulative and aggregate exposure assessment of pesticides.

PubMed

Verbeke, Wim; Van Loo, Ellen J; Vanhonacker, Filiep; Delcour, Ilse; Spanoghe, Pieter; van Klaveren, Jacob D

2015-05-01

This study evaluates the attitudes and perspectives of different stakeholder groups (agricultural producers, pesticide manufacturers, trading companies, retailers, regulators, food safety authorities, scientists and NGOs) towards the concepts of cumulative and aggregate exposure assessment of pesticides by means of qualitative in-depth interviews (n = 15) and a quantitative stakeholder survey (n = 65). The stakeholders involved generally agreed that the use of chemical pesticides is needed, primarily for meeting the need of feeding the growing world population, while clearly acknowledging the problematic nature of human exposure to pesticide residues. Current monitoring was generally perceived to be adequate, but the timeliness and consistency of monitoring practices across countries were questioned. The concept of cumulative exposure assessment was better understood by stakeholders than the concept of aggregate exposure assessment. Identified pitfalls were data availability, data limitations, sources and ways of dealing with uncertainties, as well as information and training needs. Regulators and food safety authorities were perceived as the stakeholder groups for whom cumulative and aggregate pesticide exposure assessment methods and tools would be most useful and acceptable. Insights obtained from this exploratory study have been integrated in the development of targeted and stakeholder-tailored dissemination and training programmes that were implemented within the EU-FP7 project ACROPOLIS. Copyright © 2014 Elsevier Ltd. All rights reserved.

Principles and Practices of Neurodevelopmental Assessment in Children: Lessons Learned from the Centers for Children’s Environmental Health and Disease Prevention Research

PubMed Central

Dietrich, Kim N.; Eskenazi, Brenda; Schantz, Susan; Yolton, Kimberly; Rauh, Virginia A.; Johnson, Caroline B.; Alkon, Abbey; Canfield, Richard L.; Pessah, Isaac N.; Berman, Robert F.

2005-01-01

Principles and practices of pediatric neurotoxicology are reviewed here with the purpose of guiding the design and execution of the planned National Children’s Study. The developing human central nervous system is the target organ most vulnerable to environmental chemicals. An investigation of the effects of environmental exposures on child development is a complex endeavor that requires consideration of numerous critical factors pertinent to a study’s concept, design, and execution. These include the timing of neurodevelopmental assessment, matters of biologic plausibility, site, child and population factors, data quality assurance and control, the selection of appropriate domains and measures of neurobehavior, and data safety and monitoring. Here we summarize instruments for the assessment of the neonate, infant, and child that are being employed in the Centers for Children’s Environmental Health and Disease Prevention Research, sponsored by the National Institute of Environmental Health Sciences and the U.S. Environmental Protection Agency, discuss neural and neurobiologic measures of development, and consider the promises of gene–environment studies. The vulnerability of the human central nervous system to environmental chemicals has been well established, but the contribution these exposures may make to problems such as attention deficit disorder, conduct problems, pervasive developmental disorder, or autism spectrum disorder remain uncertain. Large-scale studies such as the National Children’s Study may provide some important clues. The human neurodevelopmental phenotype will be most clearly represented in models that include environmental chemical exposures, the social milieu, and complex human genetic characteristics that we are just beginning to understand. PMID:16203260

Deciphering the complex: methodological overview of statistical models to derive OMICS-based biomarkers.

PubMed

Chadeau-Hyam, Marc; Campanella, Gianluca; Jombart, Thibaut; Bottolo, Leonardo; Portengen, Lutzen; Vineis, Paolo; Liquet, Benoit; Vermeulen, Roel C H

2013-08-01

Recent technological advances in molecular biology have given rise to numerous large-scale datasets whose analysis imposes serious methodological challenges mainly relating to the size and complex structure of the data. Considerable experience in analyzing such data has been gained over the past decade, mainly in genetics, from the Genome-Wide Association Study era, and more recently in transcriptomics and metabolomics. Building upon the corresponding literature, we provide here a nontechnical overview of well-established methods used to analyze OMICS data within three main types of regression-based approaches: univariate models including multiple testing correction strategies, dimension reduction techniques, and variable selection models. Our methodological description focuses on methods for which ready-to-use implementations are available. We describe the main underlying assumptions, the main features, and advantages and limitations of each of the models. This descriptive summary constitutes a useful tool for driving methodological choices while analyzing OMICS data, especially in environmental epidemiology, where the emergence of the exposome concept clearly calls for unified methods to analyze marginally and jointly complex exposure and OMICS datasets. Copyright © 2013 Wiley Periodicals, Inc.

Stress, Anxiety, and Immunomodulation: A Pharmacological Analysis.

PubMed

Ray, A; Gulati, K; Rai, N

2017-01-01

Stress and stressful events are common occurrences in our daily lives and such aversive situations bring about complex changes in the biological system. Such stress responses influence the brain and behavior, neuroendocrine and immune systems, and these responses orchestrate to increase or decrease the ability of the organism to cope with such stressors. The brain via expression of complex behavioral paradigms controls peripheral responses to stress and a bidirectional link exists in the modulation of stress effects. Anxiety is a common neurobehavioral correlate of a variety of stressors, and both acute and chronic stress exposure could precipitate anxiety disorders. Psychoneuroimmunology involves interactions between the brain and the immune system, and it is now being increasingly recognized that the immune system could contribute to the neurobehavioral responses to stress. Studies have shown that the brain and its complex neurotransmitter networks could influence immune function, and there could be a possible link between anxiogenesis and immunomodulation during stress. Physiological and pharmacological data have highlighted this concept, and the present review gives an overview of the relationship between stress, anxiety, and immune responsiveness. © 2017 Elsevier Inc. All rights reserved.

EPIDEMIOLOGIC CONCEPTS FOR INTERPRETING FINDINGS IN STUDIES OF DRINKING WATER EXPOSURES

EPA Science Inventory

To the inexperienced, environmental epidemiology may appear to be an uncomplicated, straightforward approach to studying exposure-disease associations in human populations. The studies can provide useful information about the risks of environmental exposures that human populatio...

Concept Maps for Improved Science Reasoning and Writing: Complexity Isn’t Everything

PubMed Central

Dowd, Jason E.; Duncan, Tanya; Reynolds, Julie A.

2015-01-01

A pervasive notion in the literature is that complex concept maps reflect greater knowledge and/or more expert-like thinking than less complex concept maps. We show that concept maps used to structure scientific writing and clarify scientific reasoning do not adhere to this notion. In an undergraduate course for thesis writers, students use concept maps instead of traditional outlines to define the boundaries and scope of their research and to construct an argument for the significance of their research. Students generate maps at the beginning of the semester, revise after peer review, and revise once more at the end of the semester. Although some students revised their maps to make them more complex, a significant proportion of students simplified their maps. We found no correlation between increased complexity and improved scientific reasoning and writing skills, suggesting that sometimes students simplify their understanding as they develop more expert-like thinking. These results suggest that concept maps, when used as an intervention, can meet the varying needs of a diverse population of student writers. PMID:26538388

Completing the Link between Exposure Science and ...

EPA Pesticide Factsheets

Driven by major scientific advances in analytical methods, biomonitoring, computation, and a newly articulated vision for a greater impact in public health, the field of exposure science is undergoing a rapid transition from a field of observation to a field of prediction. Deployment of an organizational and predictive framework for exposure science analogous to the “systems approaches” used in the biological sciences is a necessary step in this evolution. Here we propose the aggregate exposure pathway (AEP) concept as the natural and complementary companion in the exposure sciences to the adverse outcome pathway (AOP) concept in the toxicological sciences. Aggregate exposure pathways offer an intuitive framework to organize exposure data within individual units of prediction common to the field, setting the stage for exposure forecasting. Looking farther ahead, we envision direct linkages between aggregate exposure pathways and adverse outcome pathways, completing the source to outcome continuum for more meaningful integration of exposure assessment and hazard identification. Together, the two frameworks form and inform a decision-making framework with the flexibility for risk-based, hazard-based, or exposure-based decision making. The National Exposure Research Laboratory (NERL) Human Exposure and Atmospheric Sciences Division (HEASD) conducts research in support of EPA mission to protect human health and the environment. HEASD research program supports G

Pregnancy outcomes after paternal radiofrequency field exposure aboard fast patrol boats.

PubMed

Baste, Valborg; Moen, Bente E; Oftedal, Gunnhild; Strand, Leif Age; Bjørge, Line; Mild, Kjell Hansson

2012-04-01

To investigate adverse reproductive outcomes among male employees in the Royal Norwegian Navy exposed to radiofrequency electromagnetic fields aboard fast patrol boats. Cohort study of Royal Norwegian Navy servicemen linked to the Medical Birth Registry of Norway, including singleton offspring born between 1967 and 2008 (n = 37,920). Exposure during the last 3 months before conception (acute) and exposure more than 3 months before conception (nonacute) were analyzed. Perinatal mortality and preeclampsia increased after service aboard fast patrol boats during an acute period and also after increased estimated radiofrequency exposure during an acute period, compared with service aboard other vessels. No associations were found between nonacute exposure and any of the reproductive outcomes. Paternal work aboard fast patrol boats during an acute period was associated with perinatal mortality and preeclampsia, but the cause is not clear.

Using behavioral economics to promote healthy behavior toward sun exposure in adolescents and young adults.

PubMed

García-Romero, Maria T; Geller, Alan C; Kawachi, Ichiro

2015-12-01

Skin cancer represents an important public health problem, and it is associated with ultraviolet radiation exposure, particularly at early ages. Unhealthy sun exposure and intentional tanning continue to be the trend among young people. Multiple interventions to raise awareness of the risks of sun exposure have been implemented, without necessarily translating into decreased unhealthy behaviors or skin cancer incidence rates. Behavioral economics adds a set of concepts and tools to potentially boost the efficacy of existing approaches to decrease unhealthy sun exposure. This paper reviews public health interventions that have been based in behavioral economics concepts and their results, and provides examples of new and creative ways physicians and health professionals can actively apply insights from behavioral economics to counsel teenagers and young adults about skin cancer prevention. Copyright © 2015 Elsevier Inc. All rights reserved.

RadWorks Storm Shelter Design for Solar Particle Event Shielding

NASA Technical Reports Server (NTRS)

Simon, Matthew A.; Cerro, Jeffrey; Clowdsley, Martha

2013-01-01

In order to enable long-duration human exploration beyond low-Earth orbit, the risks associated with exposure of astronaut crews to space radiation must be mitigated with practical and affordable solutions. The space radiation environment beyond the magnetosphere is primarily a combination of two types of radiation: galactic cosmic rays (GCR) and solar particle events (SPE). While mitigating GCR exposure remains an open issue, reducing astronaut exposure to SPEs is achievable through material shielding because they are made up primarily of medium-energy protons. In order to ensure astronaut safety for long durations beyond low-Earth orbit, SPE radiation exposure must be mitigated. However, the increasingly demanding spacecraft propulsive performance for these ambitious missions requires minimal mass and volume radiation shielding solutions which leverage available multi-functional habitat structures and logistics as much as possible. This paper describes the efforts of NASA's RadWorks Advanced Exploration Systems (AES) Project to design minimal mass SPE radiation shelter concepts leveraging available resources. Discussion items include a description of the shelter trade space, the prioritization process used to identify the four primary shelter concepts chosen for maturation, a summary of each concept's design features, a description of the radiation analysis process, and an assessment of the parasitic mass of each concept.

VDR gene methylation as a molecular adaption to light exposure: Historic, recent and genetic influences.

PubMed

Beckett, Emma L; Jones, Patrice; Veysey, Martin; Duesing, Konsta; Martin, Charlotte; Furst, John; Yates, Zoe; Jablonski, Nina G; Chaplin, George; Lucock, Mark

2017-09-10

The vitamin D receptor (VDR) is a member of the nuclear receptor family of transcription factors. We examined whether degree of VDR gene methylation acts as a molecular adaptation to light exposure. We explored this in the context of photoperiod at conception, recent UV irradiance at 305 nm, and gene-latitude effects. Eighty subjects were examined for VDR gene-CpG island methylation density. VDR gene variants were also examined by PCR-RFLP. Photoperiod at conception was significantly positively related to VDR methylation density, explaining 17% of the variance in methylation (r 2  = 0.17; P = .001). Within this model, photoperiod at conception and plasma 25(OH)D independently predicted methylation density at the VDR-CpG island. Recent UV exposure at 305 nm led to a fivefold increase in mean methylation density (P = .02). Again, UV exposure and plasma 25(OH)D independently predicted methylation density at the VDR-CpG island. In the presence of the BsmI mutant allele, methylation density was increased (P = .01), and in the presence of the TaqI or FokI mutant allele, methylation density was decreased (P = .007 and .04 respectively). Multivariate modelling suggests plasma 25(OH)D, photoperiod at conception, recent solar irradiance, and VDR genotype combine as independent predictors of methylation at the VDR-CpG island, explaining 34% of the variance in methylation (R 2  = 0.34, P < .0001). Duration of early-life light exposure and strength of recent irradiance, along with latitudinal genetic factors, influence degree of VDR gene methylation consistent with this epigenetic phenomenon being a molecular adaptation to variation in ambient light exposure. Findings contribute to our understanding of human biology. © 2017 Wiley Periodicals, Inc.

Microbial Genetic Memory to Study Heterogeneous Soil Processes

NASA Astrophysics Data System (ADS)

Fulk, E. M.; Silberg, J. J.; Masiello, C. A.

2017-12-01

Microbes can be engineered to sense environmental conditions and produce a detectable output. These microbial biosensors have traditionally used visual outputs that are difficult to detect in soil. However, recently developed gas-producing biosensors can be used to noninvasively monitor complex soil processes such as horizontal gene transfer or cell-cell signaling. While these biosensors report on the fraction of a microbial population exposed to a process or chemical signal at the time of measurement, they do not record a "memory" of past exposure. Synthetic biologists have recently developed a suite of genetically encoded memory circuits capable of reporting on historical exposure to the signal rather than just the current state. We will provide an overview of the microbial memory systems that may prove useful to studying microbial decision-making in response to environmental conditions. Simple memory circuits can give a yes/no report of any past exposure to the signal (for example anaerobic conditions, osmotic stress, or high nitrate concentrations). More complicated systems can report on the order of exposure of a population to multiple signals or the experiences of spatially distinct populations, such as those in root vs. bulk soil. We will report on proof-of-concept experiments showing the function of a simple permanent memory system in soil-cultured microbes, and we will highlight additional applications. Finally, we will discuss challenges still to be addressed in applying these memory circuits for biogeochemical studies.

Key concepts relevant to quality of complex and shared decision-making in health care: a literature review.

PubMed

Dy, Sydney M; Purnell, Tanjala S

2012-02-01

High-quality provider-patient decision-making is key to quality care for complex conditions. We performed an analysis of key elements relevant to quality and complex, shared medical decision-making. Based on a search of electronic databases, including Medline and the Cochrane Library, as well as relevant articles' reference lists, reviews of tools, and annotated bibliographies, we developed a list of key concepts and applied them to a decision-making example. Key concepts identified included provider competence, trustworthiness, and cultural competence; communication with patients and families; information quality; patient/surrogate competence; and roles and involvement. We applied this concept list to a case example, shared decision-making for live donor kidney transplantation, and identified the likely most important concepts as provider and cultural competence, information quality, and communication with patients and families. This concept list may be useful for conceptualizing the quality of complex shared decision-making and in guiding research in this area. Copyright © 2011 Elsevier Ltd. All rights reserved.

EXPOSURES TO ENVIRONMENTAL AGENTS

EPA Science Inventory

The planned interagency National Children's Study (NCS) will be studying a number of exposure issues in the context of health and well-being of infants and young children from pre-conception to age 21. Some of the important environmental exposure questions for NCS, include: how c...

The Conceptual Complexity of Vocabulary in Elementary-Grades Core Science Program Textbooks

ERIC Educational Resources Information Center

Fitzgerald, W. Jill; Elmore, Jeff; Kung, Melody; Stenner, A. Jackson

2017-01-01

The researchers explored the conceptual complexity of vocabulary in contemporary elementary-grades core science program textbooks to address two research questions: (1) Can a progression of concepts' complexity level be described across grades? (2) Was there gradual developmental growth of the most complex concepts' networks of associated concepts…

Evaluation and characterization of fetal exposures to low frequency magnetic fields generated by laptop computers.

PubMed

Zoppetti, Nicola; Andreuccetti, Daniele; Bellieni, Carlo; Bogi, Andrea; Pinto, Iole

2011-12-01

Portable - or "laptop" - computers (LCs) are widely and increasingly used all over the world. Since LCs are often used in tight contact with the body even by pregnant women, fetal exposures to low frequency magnetic fields generated by these units can occur. LC emissions are usually characterized by complex waveforms and are often generated by the main AC power supply (when connected) and by the display power supply sub-system. In the present study, low frequency magnetic field emissions were measured for a set of five models of portable computers. For each of them, the magnetic flux density was characterized in terms not just of field amplitude, but also of the so called "weighted peak" (WP) index, introduced in the 2003 ICNIRP Statement on complex waveforms and confirmed in the 2010 ICNIRP Guidelines for low frequency fields. For the model of LC presenting the higher emission, a deeper analysis was also carried out, using numerical dosimetry techniques to calculate internal quantities (current density and in-situ electric field) with reference to a digital body model of a pregnant woman. Since internal quantities have complex waveforms too, the concept of WP index was extended to them, considering the ICNIRP basic restrictions defined in the 1998 Guidelines for the current density and in the 2010 Guidelines for the in-situ electric field. Induced quantities and WP indexes were computed using an appropriate original formulation of the well known Scalar Potential Finite Difference (SPFD) numerical method for electromagnetic dosimetry in quasi-static conditions. Copyright © 2011 Elsevier Ltd. All rights reserved.

Using Concept Maps to Monitor Knowledge Structure Changes in a Science Classroom

NASA Astrophysics Data System (ADS)

Cook, Leah J.

The aim of this research is to determine what differences may exist in students' structural knowledge while using a variety of concept mapping assessments. A concept map can be used as an assessment which connects concepts in a knowledge domain. A single assessment may not be powerful enough to establish how students' new knowledge relates to prior knowledge. More research is needed to establish how various aspects of the concept mapping task influence the output of map creation by students. Using multiple concept maps and pre-instruction and post-instruction VNOS instruments during a 16-week semester, this study was designed to investigate the impact of concept map training and the impact of assessment design on the created maps. Also, this study was designed to determine what differences can be observed between expert and novice maps and if similarities and differences exist between concept maps and an open-ended assessment. Participants created individual maps and the maps were analyzed for structural complexity, overall structure, and content. The concept maps were then compared by their timing, design, and scores. The results indicate that concept mapping training does significantly impact the shape and structure complexity of the map created by students. Additionally, these data support that students should be frequently reminded of appropriate concept mapping skills and opportunities so that good mapping skills will be utilized. Changing the assessment design does appear to be able to impact the overall structure and complexity of created maps, while narrowing the content focus of the map does not necessarily restrict the overall structure or the complexity. Furthermore, significant differences in structural complexity were observed between novice and expert mappers. The fluctuations of NOS concepts identified in student created maps may suggest why some students were still confused or had incorrect conceptions of NOS, despite explicit and reflective instruction throughout the semester.

Auditing Complex Concepts of SNOMED using a Refined Hierarchical Abstraction Network

PubMed Central

Wang, Yue; Halper, Michael; Wei, Duo; Gu, Huanying; Perl, Yehoshua; Xu, Junchuan; Elhanan, Gai; Chen, Yan; Spackman, Kent A.; Case, James T.; Hripcsak, George

2012-01-01

Auditors of a large terminology, such as SNOMED CT, face a daunting challenge. To aid them in their efforts, it is essential to devise techniques that can automatically identify concepts warranting special attention. “Complex” concepts, which by their very nature are more difficult to model, fall neatly into this category. A special kind of grouping, called a partial-area, is utilized in the characterization of complex concepts. In particular, the complex concepts that are the focus of this work are those appearing in intersections of multiple partial-areas and are thus referred to as overlapping concepts. In a companion paper, an automatic methodology for identifying and partitioning the entire collection of overlapping concepts into disjoint, singly-rooted groups, that are more manageable to work with and comprehend, has been presented. The partitioning methodology formed the foundation for the development of an abstraction network for the overlapping concepts called a disjoint partial-area taxonomy. This new disjoint partial-area taxonomy offers a collection of semantically uniform partial-areas and is exploited herein as the basis for a novel auditing methodology. The review of the overlapping concepts is done in a top-down order within semantically uniform groups. These groups are themselves reviewed in a top-down order, which proceeds from the less complex to the more complex overlapping concepts. The results of applying the methodology to SNOMED’s Specimen hierarchy are presented. Hypotheses regarding error ratios for overlapping concepts and between different kinds of overlapping concepts are formulated. Two phases of auditing the Specimen hierarchy for two releases of SNOMED are reported on. With the use of the double bootstrap and Fisher’s exact test (two-tailed), the auditing of concepts and especially roots of overlapping partial-areas is shown to yield a statistically significant higher proportion of errors. PMID:21907827

Cognitive reserve: implications for assessment and intervention.

PubMed

Stern, Yaakov

2013-01-01

The concept of reserve is used to explain the observation that some individuals function better than others in the presence of brain pathology. This article reviews the concept of reserve from its theoretical basis to the implication of reserve for clinical practice. A distinction between brain reserve, referring to individual differences in the anatomic substrate, and cognitive reserve, referring to differences in the flexibility or adaptivity of cognitive networks, is useful. Epidemiologic evidence indicates that a set of life exposures including higher educational and occupational attainment, and engaging in leisure activities is associated with a lower risk of incident dementia, suggesting that these life exposures may enhance cognitive reserve. This provides a basis for controlled clinical studies that can test specific exposures that may enhance reserve. The concept of cognitive reserve also has important implications for clinical practice in terms of diagnosis and prognosis. © 2013 S. Karger AG, Basel.

Cognitive Reserve: Implications for Assessment and Intervention

PubMed Central

Stern, Yaakov

2014-01-01

The concept of reserve is used to explain the observation that some individuals function better than others in the presence of brain pathology. This paper reviews the concept of reserve from its theoretical basis to the implication of reserve for clinical practice. A distinction between brain reserve, referring to individual differences in the anatomic substrate, and cognitive reserve, referring to differences in the flexibility or adaptivity of cognitive networks, is useful. Epidemiologic evidence indicates that a set of life exposures including higher educational and occupational attainment, and engaging in leisure activities is associated with a lower risk of incident dementia, suggesting that these life exposures may enhance cognitive reserve. This provides a basis for controlled clinical studies can test specific exposures that may enhance reserve. The concept of cognitive reserve also has important implications for clinical practice in terms of diagnosis and prognosis. PMID:23941972

Subfertility in relation to welding. A case referent study among male welders.

PubMed

Bonde, J P

1990-02-01

A recent report indicates that welding work is associated with increased risk of reduced semen quality. The purpose of this study was to investigate a possible association between welding exposure and male subfertility. A cross-sectional population of 673 metal workers and electricians employed at six major Danish work places in the same geographic area constituted the study population. Data on reproductive and occupational experience was obtained by means of a self-administered postal questionnaire. The response rate was 79 percent among welders and 83 percent among the other workers. A significantly increased rate of delayed conception in relation to welding work at the time of this event was observed when self-reported welding exposure among cases of delayed conception was compared to welding exposure both among age-matched referents and among referents with a child born without delay in conception. However, in the first approach the risk dropped to insignificant levels when adjustments were made for potential confounding factors. This preliminary study has methodological drawbacks, and the association between welding exposure and male fertility should be investigated further.

Embedding Sustainability and Renewable Energy Concepts into Undergraduate Curriculum

NASA Astrophysics Data System (ADS)

Belu, R.; Cioca, L.

2017-12-01

Human society is facing an uncertain future due to the present unsustainable use of natural resources and the growing imbalance with our natural environment. Creation of a sustainable society is a complex multi-disciplinary and multi-stage project, believed to dominate our century, requiring collaboration, teamwork, and abilities to work with respect and learn from other disciplines and professions. Sustainable development means technological progress meeting the present needs without compromising future generation ability to meet its needs and aspirations. It has four aspects: environment, technology, economy, and societal organizations. Students are often taught to deal with technological developments and economic analysis to assess the process or product viability, but are not fully familiar with sustainability and optimization of technology development benefits and the environment. Schools in many disciplines are working to include sustainability concepts into their curricula. Teaching sustainability and renewable energy has become an essential feature today higher education. Sustainable and green design is about designs recognizing the constraints of the natural resource uses and the environment. It applies to all of engineering and science areas, as all systems interact with the environment in complex and important ways. Our project goals are to provide students with multiple and comprehensive exposures to sustainability and renewable energy concepts, facilitating the development of passion and skills to integrate them into practice. The expected outcomes include an increased social responsibility; development of innovative thinking skills; understanding of sustainability issues, and increasing student interests in the engineering and science programs. The project aims to incorporate sustainability and renewable energy concepts into our undergraduate curricula, employing the existing course resources, and developing new courses and laboratory experiments. Approaches described are: 1) redesigning existing courses through development of new materials that still meet the original course objectives and 2) developing upper division elective courses, addressing specific topics related to sustainability, renewable energy and green design.

Health effects of prenatal radiation exposure.

PubMed

Williams, Pamela M; Fletcher, Stacy

2010-09-01

Pregnant women are at risk of exposure to nonionizing and ionizing radiation resulting from necessary medical procedures, workplace exposure, and diagnostic or therapeutic interventions before the pregnancy is known. Nonionizing radiation includes microwave, ultrasound, radio frequency, and electromagnetic waves. In utero exposure to nonionizing radiation is not associated with significant risks; therefore, ultrasonography is safe to perform during pregnancy. Ionizing radiation includes particles and electromagnetic radiation (e.g., gamma rays, x-rays). In utero exposure to ionizing radiation can be teratogenic, carcinogenic, or mutagenic. The effects are directly related to the level of exposure and stage of fetal development. The fetus is most susceptible to radiation during organogenesis (two to seven weeks after conception) and in the early fetal period (eight to 15 weeks after conception). Noncancer health effects have not been detected at any stage of gestation after exposure to ionizing radiation of less than 0.05 Gy (5 rad). Spontaneous abortion, growth restriction, and mental retardation may occur at higher exposure levels. The risk of cancer is increased regardless of the dose. When an exposure to ionizing radiation occurs, the total fetal radiation dose should be estimated and the mother counseled about the potential risks so that she can make informed decisions about her pregnancy management.

Vertical leadership in highly complex and unpredictable health systems.

PubMed

Till, Alex; Dutta, Nina; McKimm, Judy

2016-08-02

This article explores how the concept of vertical leadership development might help health organizations cope with and thrive within highly complex and unpredictable health systems, looking at concepts of VUCA (volatility, uncertainty, complexity and ambiguity) and RUPT (rapid, unpredictable, paradoxical and tangled).

High-throughput PBPK and Microdosimetry: Cell-level Exposures in a Virtual Tissue Context (WC9)

EPA Science Inventory

Toxicokinetic (TK) models can determine whether chemical exposures produce potentially hazardous tissue concentrations. Tissue microdosimetry TK models relate whole-body chemical exposures to cell-scale concentrations. As a proof of concept, we approximated the micro-anatomic arc...

Truncated Lévy flights and agenda-based mobility are useful for the assessment of personal human exposure.

PubMed

Schlink, Uwe; Ragas, Ad M J

2011-01-01

Receptor-oriented approaches can assess the individual-specific exposure to air pollution. In such an individual-based model we analyse the impact of human mobility to the personal exposure that is perceived by individuals simulated in an exemplified urban area. The mobility models comprise random walk (reference point mobility, RPM), truncated Lévy flights (TLF), and agenda-based walk (RPMA). We describe and review the general concepts and provide an inter-comparison of these concepts. Stationary and ergodic behaviour are explained and applied as well as performance criteria for a comparative evaluation of the investigated algorithms. We find that none of the studied algorithm results in purely random trajectories. TLF and RPMA prove to be suitable for human mobility modelling, because they provide conditions for very individual-specific trajectories and exposure. Suggesting these models we demonstrate the plausibility of their results for exposure to air-borne benzene and the combined exposure to benzene and nonane. Copyright © 2011 Elsevier Ltd. All rights reserved.

Translating concepts of complexity to the field of ergonomics.

PubMed

Walker, Guy H; Stanton, Neville A; Salmon, Paul M; Jenkins, Daniel P; Rafferty, Laura

2010-10-01

Since 1958 more than 80 journal papers from the mainstream ergonomics literature have used either the words 'complex' or 'complexity' in their titles. Of those, more than 90% have been published in only the past 20 years. This observation communicates something interesting about the way in which contemporary ergonomics problems are being understood. The study of complexity itself derives from non-linear mathematics but many of its core concepts have found analogies in numerous non-mathematical domains. Set against this cross-disciplinary background, the current paper aims to provide a similar initial mapping to the field of ergonomics. In it, the ergonomics problem space, complexity metrics and powerful concepts such as emergence raise complexity to the status of an important contingency factor in achieving a match between ergonomics problems and ergonomics methods. The concept of relative predictive efficiency is used to illustrate how this match could be achieved in practice. What is clear overall is that a major source of, and solution to, complexity are the humans in systems. Understanding complexity on its own terms offers the potential to leverage disproportionate effects from ergonomics interventions and to tighten up the often loose usage of the term in the titles of ergonomics papers. STATEMENT OF RELEVANCE: This paper reviews and discusses concepts from the study of complexity and maps them to ergonomics problems and methods. It concludes that humans are a major source of and solution to complexity in systems and that complexity is a powerful contingency factor, which should be considered to ensure that ergonomics approaches match the true nature of ergonomics problems.

Diagnosis, monitoring and prevention of exposure-related non-communicable diseases in the living and working environment: DiMoPEx-project is designed to determine the impacts of environmental exposure on human health.

PubMed

Budnik, Lygia Therese; Adam, Balazs; Albin, Maria; Banelli, Barbara; Baur, Xaver; Belpoggi, Fiorella; Bolognesi, Claudia; Broberg, Karin; Gustavsson, Per; Göen, Thomas; Fischer, Axel; Jarosinska, Dorota; Manservisi, Fabiana; O'Kennedy, Richard; Øvrevik, Johan; Paunovic, Elizabet; Ritz, Beate; Scheepers, Paul T J; Schlünssen, Vivi; Schwarzenbach, Heidi; Schwarze, Per E; Sheils, Orla; Sigsgaard, Torben; Van Damme, Karel; Casteleyn, Ludwine

2018-01-01

The WHO has ranked environmental hazardous exposures in the living and working environment among the top risk factors for chronic disease mortality. Worldwide, about 40 million people die each year from noncommunicable diseases (NCDs) including cancer, diabetes, and chronic cardiovascular, neurological and lung diseases. The exposure to ambient pollution in the living and working environment is exacerbated by individual susceptibilities and lifestyle-driven factors to produce complex and complicated NCD etiologies. Research addressing the links between environmental exposure and disease prevalence is key for prevention of the pandemic increase in NCD morbidity and mortality. However, the long latency, the chronic course of some diseases and the necessity to address cumulative exposures over very long periods does mean that it is often difficult to identify causal environmental exposures. EU-funded COST Action DiMoPEx is developing new concepts for a better understanding of health-environment (including gene-environment) interactions in the etiology of NCDs. The overarching idea is to teach and train scientists and physicians to learn how to include efficient and valid exposure assessments in their research and in their clinical practice in current and future cooperative projects. DiMoPEx partners have identified some of the emerging research needs, which include the lack of evidence-based exposure data and the need for human-equivalent animal models mirroring human lifespan and low-dose cumulative exposures. Utilizing an interdisciplinary approach incorporating seven working groups, DiMoPEx will focus on aspects of air pollution with particulate matter including dust and fibers and on exposure to low doses of solvents and sensitizing agents. Biomarkers of early exposure and their associated effects as indicators of disease-derived information will be tested and standardized within individual projects. Risks arising from some NCDs, like pneumoconioses, cancers and allergies, are predictable and preventable. Consequently, preventative action could lead to decreasing disease morbidity and mortality for many of the NCDs that are of major public concern. DiMoPEx plans to catalyze and stimulate interaction of scientists with policy-makers in attacking these exposure-related diseases.

Abstraction of complex concepts with a refined partial-area taxonomy of SNOMED

PubMed Central

Wang, Yue; Halper, Michael; Wei, Duo; Perl, Yehoshua; Geller, James

2012-01-01

An algorithmically-derived abstraction network, called the partial-area taxonomy, for a SNOMED hierarchy has led to the identification of concepts considered complex. The designation “complex” is arrived at automatically on the basis of structural analyses of overlap among the constituent concept groups of the partial-area taxonomy. Such complex concepts, called overlapping concepts, constitute a tangled portion of a hierarchy and can be obstacles to users trying to gain an understanding of the hierarchy’s content. A new methodology for partitioning the entire collection of overlapping concepts into singly-rooted groups, that are more manageable to work with and comprehend, is presented. Different kinds of overlapping concepts with varying degrees of complexity are identified. This leads to an abstract model of the overlapping concepts called the disjoint partial-area taxonomy, which serves as a vehicle for enhanced, high-level display. The methodology is demonstrated with an application to SNOMED’s Specimen hierarchy. Overall, the resulting disjoint partial-area taxonomy offers a refined view of the hierarchy’s structural organization and conceptual content that can aid users, such as maintenance personnel, working with SNOMED. The utility of the disjoint partial-area taxonomy as the basis for a SNOMED auditing regimen is presented in a companion paper. PMID:21878396

Messages that increase women’s intentions to abstain from alcohol during pregnancy: results from quantitative testing of advertising concepts

PubMed Central

2014-01-01

Background Public awareness-raising campaigns targeting alcohol use during pregnancy are an important part of preventing prenatal alcohol exposure and Fetal Alcohol Spectrum Disorder. Despite this, there is little evidence on what specific elements contribute to campaign message effectiveness. This research evaluated three different advertising concepts addressing alcohol and pregnancy: a threat appeal, a positive appeal promoting a self-efficacy message, and a concept that combined the two appeals. The primary aim was to determine the effectiveness of these concepts in increasing women’s intentions to abstain from alcohol during pregnancy. Methods Women of childbearing age and pregnant women residing in Perth, Western Australia participated in a computer-based questionnaire where they viewed either a control or one of the three experimental concepts. Following exposure, participants’ intentions to abstain from and reduce alcohol intake during pregnancy were measured. Other measures assessed included perceived main message, message diagnostics, and potential to promote defensive responses or unintended consequences. Results The concepts containing a threat appeal were significantly more effective at increasing women’s intentions to abstain from alcohol during pregnancy than the self-efficacy message and the control. The concept that combined threat and self-efficacy is recommended for development as part of a mass-media campaign as it has good persuasive potential, provides a balance of positive and negative emotional responses, and is unlikely to result in defensive or unintended consequences. Conclusions This study provides important insights into the components that enhance the persuasiveness and effectiveness of messages aimed at preventing prenatal alcohol exposure. The recommended concept has good potential for use in a future campaign aimed at promoting women’s intentions to abstain from alcohol during pregnancy. PMID:24410764

Messages that increase women's intentions to abstain from alcohol during pregnancy: results from quantitative testing of advertising concepts.

PubMed

France, Kathryn E; Donovan, Robert J; Bower, Carol; Elliott, Elizabeth J; Payne, Janet M; D'Antoine, Heather; Bartu, Anne E

2014-01-13

Public awareness-raising campaigns targeting alcohol use during pregnancy are an important part of preventing prenatal alcohol exposure and Fetal Alcohol Spectrum Disorder. Despite this, there is little evidence on what specific elements contribute to campaign message effectiveness. This research evaluated three different advertising concepts addressing alcohol and pregnancy: a threat appeal, a positive appeal promoting a self-efficacy message, and a concept that combined the two appeals. The primary aim was to determine the effectiveness of these concepts in increasing women's intentions to abstain from alcohol during pregnancy. Women of childbearing age and pregnant women residing in Perth, Western Australia participated in a computer-based questionnaire where they viewed either a control or one of the three experimental concepts. Following exposure, participants' intentions to abstain from and reduce alcohol intake during pregnancy were measured. Other measures assessed included perceived main message, message diagnostics, and potential to promote defensive responses or unintended consequences. The concepts containing a threat appeal were significantly more effective at increasing women's intentions to abstain from alcohol during pregnancy than the self-efficacy message and the control. The concept that combined threat and self-efficacy is recommended for development as part of a mass-media campaign as it has good persuasive potential, provides a balance of positive and negative emotional responses, and is unlikely to result in defensive or unintended consequences. This study provides important insights into the components that enhance the persuasiveness and effectiveness of messages aimed at preventing prenatal alcohol exposure. The recommended concept has good potential for use in a future campaign aimed at promoting women's intentions to abstain from alcohol during pregnancy.

Growth as a mirror: Is endocrine disruption challenging Tanner's concept?

PubMed Central

Schell, Lawrence M.; Burnitz, Kristopher K.; Gallo, Mia V.

2012-01-01

Background James Tanner coined the expression `Growth as a Mirror' and summarized in four words the results of more than a century of research on growth. Nineteenth century social reformers saw poor child growth as a reflection of terrible environmental conditions of the working class. Later investigators in anthropology and other fields clarified the connections between poor nutrition, disease, psychosocial stress and poor growth. Aim To evaluate the growth as a mirror concept in light of recent studies of endocrine disruption. Papers and Implications Pollution is recognized as a prominent component of the modern environment. From studies of many pollutants it is clear that some pollutants depress growth while others speed sexual maturation and increase growth, primarily in weight and fatness. While such unwelcome environmental features do not always suppress growth, growth still mirrors the environment in all its complexity and this relationship is key to understanding growth patterns today. For example, Akwesasne Mohawk adolescents are characterized by high rates of obesity and overweight. Their growth reflects the multiple intersecting influences of psychosocial stress, several pollutant exposures and limited dietary chokes. Conclusion Although Tanner did not anticipate the myriad influences of pollutants, the growth as a mirror concept continues to have great validity and utility. PMID:22780455

Exploring the practicing-connections hypothesis: using gesture to support coordination of ideas in understanding a complex statistical concept.

PubMed

Son, Ji Y; Ramos, Priscilla; DeWolf, Melissa; Loftus, William; Stigler, James W

2018-01-01

In this article, we begin to lay out a framework and approach for studying how students come to understand complex concepts in rich domains. Grounded in theories of embodied cognition, we advance the view that understanding of complex concepts requires students to practice, over time, the coordination of multiple concepts, and the connection of this system of concepts to situations in the world. Specifically, we explore the role that a teacher's gesture might play in supporting students' coordination of two concepts central to understanding in the domain of statistics: mean and standard deviation. In Study 1 we show that university students who have just taken a statistics course nevertheless have difficulty taking both mean and standard deviation into account when thinking about a statistical scenario. In Study 2 we show that presenting the same scenario with an accompanying gesture to represent variation significantly impacts students' interpretation of the scenario. Finally, in Study 3 we present evidence that instructional videos on the internet fail to leverage gesture as a means of facilitating understanding of complex concepts. Taken together, these studies illustrate an approach to translating current theories of cognition into principles that can guide instructional design.

Systems for Teaching Complex Texts: A Proof-of-Concept Investigation

ERIC Educational Resources Information Center

Fisher, Douglas; Frey, Nancy

2016-01-01

In this article we investigate the systems that need to be in place for students to learn from increasingly complex texts. Our concept, drawn from past research, includes clear learning targets, teacher modeling, collaborative conversations, close reading, small group reading, and wide reading. Using a "proof of concept" model, we follow…

Defining Product Intake Fraction to Quantify and Compare Exposure to Consumer Products.

PubMed

Jolliet, Olivier; Ernstoff, Alexi S; Csiszar, Susan A; Fantke, Peter

2015-08-04

There is a growing consciousness that exposure studies need to better cover near-field exposure associated with products use. To consistently and quantitatively compare human exposure to chemicals in consumer products, we introduce the concept of product intake fraction, as the fraction of a chemical within a product that is eventually taken in by the human population. This metric enables consistent comparison of exposures during consumer product use for different product-chemical combinations, exposure duration, exposure routes and pathways and for other life cycle stages. We present example applications of the product intake fraction concept, for two chemicals in two personal care products and two chemicals encapsulated in two articles, showing how intakes of these chemicals can primarily occur during product use. We demonstrate the utility of the product intake fraction and its application modalities within life cycle assessment and risk assessment contexts. The product intake fraction helps to provide a clear interface between the life cycle inventory and impact assessment phases, to identify best suited sentinel products and to calculate overall exposure to chemicals in consumer products, or back-calculate maximum allowable concentrations of substances inside products.

Is patient size important in dose determination and optimization in cardiology?

NASA Astrophysics Data System (ADS)

Reay, J.; Chapple, C. L.; Kotre, C. J.

2003-12-01

Patient dose determination and optimization have become more topical in recent years with the implementation of the Medical Exposures Directive into national legislation, the Ionising Radiation (Medical Exposure) Regulations. This legislation incorporates a requirement for new equipment to provide a means of displaying a measure of patient exposure and introduces the concept of diagnostic reference levels. It is normally assumed that patient dose is governed largely by patient size; however, in cardiology, where procedures are often very complex, the significance of patient size is less well understood. This study considers over 9000 cardiology procedures, undertaken throughout the north of England, and investigates the relationship between patient size and dose. It uses simple linear regression to calculate both correlation coefficients and significance levels for data sorted by both room and individual clinician for the four most common examinations, left ventrical and/or coronary angiography, single vessel stent insertion and single vessel angioplasty. This paper concludes that the correlation between patient size and dose is weak for the procedures considered. It also illustrates the use of an existing method for removing the effect of patient size from dose survey data. This allows typical doses and, therefore, reference levels to be defined for the purposes of dose optimization.

Female reproductive disorders: the roles of endocrine-disrupting compounds and developmental timing

PubMed Central

Crain, D. Andrew; Janssen, Sarah J.; Edwards, Thea M.; Heindel, Jerrold; Ho, Shuk-mei; Hunt, Patricia; Iguchi, Taisen; Juul, Anders; McLachlan, John A.; Schwartz, Jackie; Skakkebaek, Niels; Soto, Ana M.; Swan, Shanna; Walker, Cheryl; Woodruff, Teresa K.; Woodruff, Tracey J.; Giudice, Linda C.; Guillette, Louis J.

2014-01-01

Objective To evaluate the possible role of endocrine-disrupting compounds (EDCs) on female reproductive disorders emphasizing developmental plasticity and the complexity of endocrine-dependent ontogeny of reproductive organs. Declining conception rates and the high incidence of female reproductive disruptions warrant evaluation of the impact of EDCs on female reproductive health. Design Publications related to the contribution of EDCs to disorders of the ovary (aneuploidy, polycystic ovary syndrome, and altered cyclicity), uterus (endometriosis, uterine fibroids, fetal growth restriction, and pregnancy loss), breast (breast cancer, reduced duration of lactation), and pubertal timing were identified, reviewed, and summarized at a workshop. Conclusion(s) The data reviewed illustrate that EDCs contribute to numerous human female reproductive disorders and emphasize the sensitivity of early life-stage exposures. Many research gaps are identified that limit full understanding of the contribution of EDCs to female reproductive problems. Moreover, there is an urgent need to reduce the incidence of these reproductive disorders, which can be addressed by correlative studies on early life exposure and adult reproductive dysfunction together with tools to assess the specific exposures and methods to block their effects. This review of the EDC literature as it relates to female health provides an important platform on which women’s health can be improved. PMID:18929049

Enhanced LOD Concepts for Virtual 3d City Models

NASA Astrophysics Data System (ADS)

Benner, J.; Geiger, A.; Gröger, G.; Häfele, K.-H.; Löwner, M.-O.

2013-09-01

Virtual 3D city models contain digital three dimensional representations of city objects like buildings, streets or technical infrastructure. Because size and complexity of these models continuously grow, a Level of Detail (LoD) concept effectively supporting the partitioning of a complete model into alternative models of different complexity and providing metadata, addressing informational content, complexity and quality of each alternative model is indispensable. After a short overview on various LoD concepts, this paper discusses the existing LoD concept of the CityGML standard for 3D city models and identifies a number of deficits. Based on this analysis, an alternative concept is developed and illustrated with several examples. It differentiates between first, a Geometric Level of Detail (GLoD) and a Semantic Level of Detail (SLoD), and second between the interior building and its exterior shell. Finally, a possible implementation of the new concept is demonstrated by means of an UML model.

Effects of Lifetime Occupational Pesticide Exposure on Postural Control Among Farmworkers and Non-Farmworkers.

PubMed

Sunwook, Kim; Nussbaum, Maury A; Quandt, Sara A; Laurienti, Paul J; Arcury, Thomas A

2016-02-01

The aim of the study was to assess potential chronic effects of pesticide exposure on postural control, by examining postural balance of farmworkers and non-farmworkers diverse self-reported lifetime exposures. Balance was assessed during quiet upright stance under four experimental conditions (2 visual × 2 cognitive difficulty). Significant differences in baseline balance performance (eyes open without cognitive task) between occupational groups were apparent in postural sway complexity. When adding a cognitive task to the eyes open condition, the influence of lifetime exposure on complexity ratios appeared different between occupational groups. Removing visual information revealed a negative association of lifetime exposure with complexity ratios. Farmworkers and non-farmworkers may use different postural control strategies even when controlling for the level of lifetime pesticide exposure. Long-term exposure can affect somatosensory/vestibular sensory systems and the central processing of sensory information for postural control.

Effects of lifetime occupational pesticide exposure on postural control among farmworkers and non-farmworkers

PubMed Central

Sunwook, Kim; Nussbaum, Maury A.; Quandt, Sara A.; Laurienti, Paul J.; Arcury, Thomas A.

2015-01-01

Objective Assess potential chronic effects of pesticide exposure on postural control, by examining postural balance of farmworkers and non-farmworkers diverse self-reported lifetime exposures. Methods Balance was assessed during quiet upright stance under four experimental conditions (2 visual × 2 cognitive difficulty). Results Significant differences in baseline balance performance (eyes open without cognitive task) between occupational groups were apparent in postural sway complexity. When adding a cognitive task to the eyes open condition, the influence of lifetime exposure on complexity ratios appeared different between occupational groups. Removing visual information revealed a negative association of lifetime exposure with complexity ratios. Conclusions Farmworkers and non-farmworkers may use different postural control strategies even when controlling for the level of lifetime pesticide exposure. Long-term exposure can affect somatosensory/vestibular sensory systems and the central processing of sensory information for postural control. PMID:26849257

For good measure: Origins and prospects of exposure science (2007 Wesolowski Award Lecture).

PubMed

Fenske, Richard A

2010-09-01

Measurement is the foundation of exposure science. Associations between illness and environmental agents have been observed for millennia, but the ability to quantify exposure and dose has been possible only in the last century. Improved means of measurement and refined concepts of who, what, when, where, and why to measure have been the seminal contributions of exposure science to the study of disease causation and prevention. This paper examines critical advancements in exposure assessment associated with workplace health and safety, and the groundbreaking work of the US Public Health Service. Many of the key concepts of modern exposure science have their origin in these early studies. Occupational hygiene scientists have conducted receptor-based exposure analyses for more than 80 years, evaluating indoor air, defining microenvironments, and developing personal sampling techniques. Biological monitoring of community populations including children, dermal exposure monitoring, duplicate diet studies, and multi-pathway, aggregate exposure assessments can be traced to early public health studies. As we look to the future, we see that new technologies and techniques are expanding the scope of exposure science dramatically. We need to ensure that the highest of scientific standards are maintained, make a greater effort to include occupational hygiene scientists, microbiologists, and behavioral scientists in the field, and promote new sources of training and research support. Exposure science has a critical role to play in the prevention strategy that is central to public health.

Teaching surgical exposures to undergraduate medical students: an integration concept for anatomical and surgical education.

PubMed

Hammer, Niels; Hepp, Pierre; Löffler, Sabine; Schleifenbaum, Stefan; Steinke, Hanno; Klima, Stefan

2015-06-01

Decreasing numbers of students are interested in starting a surgical career, posing substantial challenges to patient care in the next years. The anatomy course is one of the key subjects in medical training, especially in surgical disciplines. Innovative teaching concepts that integrate surgically relevant anatomy and manual dexterity might help boost student interest in surgery. A preclinical workshop entitled "Surgical exposures" was developed. A team of anatomists and surgeons introduced the surgical exposures, demonstrating the procedures on Thiel-fixed body donors. Following this introduction, students practiced the exposures in an operating room-like manner. A six-point Likert scale was used to evaluate the workshop and to compare it to the first-year dissection course. The overall evaluation result for the surgical exposures was excellent, proving to be a significantly better result when compared to the first-year dissection course. The students were more satisfied with the teaching time invested by the peers and regarded the workshop as clinically highly relevant. Furthermore, they felt that questions were addressed better and that the overall atmosphere was better than in the gross anatomy course. Subject to criticism was the course size and practicing time in both cases. The surgical exposures workshop provides preclinical students with clinically relevant anatomy and manual dexterity. It may positively influence the decision to follow a surgical career. This course, however, requires extensive teaching resources. The given concept may help implement practical medical skills in the preclinical curriculum, strengthening the professional identity of surgeons and anatomists.

An essay on 'health capital' and the Faustian bargains struck by workers in the globalised shipping industry.

PubMed

Bloor, Michael

2011-11-01

It has long been understood that work directly generates ill health and disability through injuries and occupational exposure to toxic and carcinogenic materials, but the more complex relationship between work and ill health that is seemingly mediated through psychological distress is more controversial. For example, the 'Karasek model', whereby high job demands coupled with limited latitude in decision making were thought to generate ill health, has not been supported in large-scale surveys. This paper postulates an alternative linking mechanism between work and health, namely Mildred Blaxter's concept of 'health capital', and specifically explores the value of the concept in understanding lay theorising about the links between labour intensification and self-perceived health: workers' perceptions that their work has become more effortful may be bracketed with their belief that their continuing employment is demanding accelerating expenditure of their health capital. The argument is illustrated by qualitative interviews with an international sample of seafarers, a proto-typically globalised labour force. 2011 The Author. Sociology of Health & Illness, 2011 Foundation for the Sociology of Health & Illness/Blackwell Publishing Ltd.

Thinking of God Moves Attention

ERIC Educational Resources Information Center

Chasteen, Alison L.; Burdzy, Donna C.; Pratt, Jay

2010-01-01

The concepts of God and Devil are well known across many cultures and religions, and often involve spatial metaphors, but it is not well known if our mental representations of these concepts affect visual cognition. To examine if exposure to divine concepts produces shifts of attention, participants completed a target detection task in which they…

Natural Conception May Be an Acceptable Option in HIV-Serodiscordant Couples in Resource Limited Settings.

PubMed

Sun, Lijun; Wang, Fang; Liu, An; Xin, Ruolei; Zhu, Yunxia; Li, Jianwei; Shao, Ying; Ye, Jiangzhu; Chen, Danqing; Li, Zaicun

2015-01-01

Many HIV serodiscordant couples have a strong desire to have their own biological children. Natural conception may be the only choice in some resource limited settings but data about natural conception is limited. Here, we reported our findings of natural conception in HIV serodiscordant couples. Between January 2008 and June 2014, we retrospectively collected data on 91 HIV serodiscordant couples presenting to Beijing Youan Hospital with childbearing desires. HIV counseling, effective ART on HIV infected partners, pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP) in negative female partners and timed intercourse were used to maximally reduce the risk of HIV transmission. Of the 91 HIV serodiscordant couples, 43 were positive in male partners and 48 were positive in female partners. There were 196 unprotected vaginal intercourses, 100 natural conception and 97 newborns. There were no cases of HIV seroconversion in uninfected sexual partners. Natural conception may be an acceptable option in HIV-serodiscordant couples in resource limited settings if HIV-positive individuals have undetectable viremia on HAART, combined with HIV counseling, PrEP, PEP and timed intercourse.

A concept analysis of women's vulnerability during pregnancy, birth and the postnatal period.

PubMed

Briscoe, Lesley; Lavender, Tina; McGowan, Linda

2016-10-01

To report an analysis of the concept of vulnerability associated with pregnancy, birth and the postnatal period. The concept of vulnerability during childbirth is complex and the term, 'to be vulnerable' frequently attains a vague application. Analysis about vulnerability is needed to guide policy, practice, education and research. Clarity around the concept has the potential to improve outcomes for women. Concept analysis. Searches were conducted in CINAHL, EMBASE, PubMed, Psychinfo, MEDLINE, MIDIRS and ASSIA and limited to between January 2000 - June 2014. Data were collected over 12 months during 2014. This concept analysis drew on Morse's qualitative methods. Vulnerability during pregnancy, birth and the postnatal period can be defined by three main attributes: (a) Threat; (b) Barrier; and (c) Repair. Key attributes have the potential to influence outcome for women. Inseparable sub-attributes such as mother and baby attachment, the woman's free will and choice added a level of complexity about the concept. This concept analysis has clarified how the term vulnerability is currently understood and used in relation to pregnancy, birth and the postnatal period. Vulnerability should be viewed as a complex phenomenon rather than a singular concept. A 'vulnerability journey plan' has the potential to identify how reparative interventions may develop the woman's capacity for resilience and influence the degree of vulnerability experienced. Methodology based around complex theory should be explored in future work about vulnerability. © 2016 John Wiley & Sons Ltd.

Exposure to cigarette advertising and adolescents' intentions to smoke: the moderating role of the developing self-concept.

PubMed

Shadel, William G; Tharp-Taylor, Shannah; Fryer, Craig S

2008-08-01

Increased exposure to cigarette advertisements is associated with increases in adolescent smoking but the reasons for this association are not known. This study evaluated whether the developmental maturity of the self-concept, operationalized as self-conflict, moderated smoking intentions following exposure to cigarette advertisements among adolescents who have never smoked. Eighty-seven adolescents (ages 11-17): (a) completed measures of self-conflict; (b) were exposed to 30 contemporary cigarette advertisements; and (c) rated their intentions to smoke following exposure to each ad. Younger adolescents with higher numbers of self-conflicts who also said that cigarette advertising was relevant to them had stronger smoking intentions compared to younger adolescents with lower numbers of self-conflicts after exposure to cigarette advertising. Self-conflict did not play as strong a role with older adolescents. Younger adolescents (i.e., middle school aged) who are having the most difficulty figuring out "who they are" are most susceptible to the effects of cigarette advertising.

The optimisation of occupational potential exposures - preliminary considerations

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

Crouail, P.; Guimaraes, L.

1995-03-01

One of the major innovation brought about the ICRP 60 recommendations and emphasized by the ICRP 64 publication, is the introduction of the concept of potential exposures into the system of radiological protection. Potential exposures are characterized by {open_quotes}probability of occurrence lesser than unity{close_quotes} and {open_quotes}radiological risks exceeding normal levels{close_quotes} where normal must be interpreted as not exceeding the planned routine exposures. It is then necessary to develop consensual methods to look for and choose the optimum scenarios (i.e. those for which probability of events and possible consequences have been reduced as low as reasonably achievable). Moreover, the boundaries formore » the unacceptable levels of risks for workers should be defined, as well as reasonable risk indicators. The aim of this paper is to discuss the actual changes in the field of occupational radiological protection, induced by the potential exposure concept with particular emphasize on the optimization of protection.« less

Is Lead Exposure in Early Life An Environmental Risk Factor for Schizophrenia? Neurobiological Connections and Testable Hypotheses

PubMed Central

Guilarte, Tomás R.; Opler, Mark; Pletnikov, Mikhail

2013-01-01

Schizophrenia is a devastating neuropsychiatric disorder of unknown etiology. There is general agreement in the scientific community that schizophrenia is a disorder of neurodevelopmental origin in which both genes and environmental factors come together to produce a schizophrenia phenotype later in life. The challenging questions have been which genes and what environmental factors? Although there is evidence that different chromosome loci and several genes impart susceptibility for schizophrenia; and epidemiological studies point to broad aspects of the environment, only recently there has been an interest in studying gene × environment interactions. Recent evidence of a potential association between prenatal lead (Pb2+) exposure and schizophrenia precipitated the search for plausible neurobiological connections. The most promising connection is that in schizophrenia and in developmental Pb2+ exposure there is strong evidence for hypoactivity of the N-methyl-d-aspartate (NMDA) subtype of excitatory amino acid receptors as an underlying neurobiological mechanism in both conditions. A hypofunction of the NMDA receptor (NMDAR) complex during critical periods of development may alter neurobiological processes that are essential for brain growth and wiring, synaptic plasticity and cognitive and behavioral outcomes associated with schizophrenia. We also describe on-going proof of concept gene-environment interaction studies of early life Pb2+ exposure in mice expressing the human mutant form of the disrupted in schizophrenia 1 (DISC-1) gene, a gene that is strongly associated with schizophrenia and allied mental disorders. PMID:22178136

CSEO – the Cigarette Smoke Exposure Ontology

PubMed Central

2014-01-01

Background In the past years, significant progress has been made to develop and use experimental settings for extensive data collection on tobacco smoke exposure and tobacco smoke exposure-associated diseases. Due to the growing number of such data, there is a need for domain-specific standard ontologies to facilitate the integration of tobacco exposure data. Results The CSEO (version 1.0) is composed of 20091 concepts. The ontology in its current form is able to capture a wide range of cigarette smoke exposure concepts within the knowledge domain of exposure science with a reasonable sensitivity and specificity. Moreover, it showed a promising performance when used to answer domain expert questions. The CSEO complies with standard upper-level ontologies and is freely accessible to the scientific community through a dedicated wiki at https://publicwiki-01.fraunhofer.de/CSEO-Wiki/index.php/Main_Page. Conclusions The CSEO has potential to become a widely used standard within the academic and industrial community. Mainly because of the emerging need of systems toxicology to controlled vocabularies and also the lack of suitable ontologies for this domain, the CSEO prepares the ground for integrative systems-based research in the exposure science. PMID:25093069

Some Exercises Reflecting Green Chemistry Concepts

ERIC Educational Resources Information Center

Song, Yu-Min; Wang, Yong-Cheng; Geng, Zhi-Yuan

2004-01-01

Some exercises to introduce students to the concept of green chemistry are given. By doing these exercises, students develop an appreciation for the role of green chemistry on feedstock substitution, milder reaction conditions, reduced environmental exposure, and resource conservation.

School-Based Study of Complex Environmental Exposures and Related Health Effects in Children: Part A - Exposure. Final Report and Executive Summary.

ERIC Educational Resources Information Center

Minnesota Univ., Minneapolis. School of Public Health.

The School Health Initiative: Environment, Learning, and Disease (SHIELD) study examined children's exposure to complex mixtures of environmental agents (i.e., volatile organic chemicals, environmental tobacco smoke, allergens, bioaerosols, metals, and pesticides). Environmental, personal, and biological data were collected on ethnically and…

The core learning objectives education model: an approach to the teaching of core concepts in the clinical clerkship.

PubMed

Rapp, David E; Lyon, Mark B; Orvieto, Marcelo A; Zagaja, Gregory P

2005-10-01

The classical approach to the undergraduate medical clerkship has several limitations, including variability of clinical exposure and method of examination. As a result, the clerkship experience does not ensure exposure to and reinforcement of the fundamental concepts of a given specialty. This article reviews the classic approach to clerkship education within the undergraduate medical education. Specific attention is placed on clinical exposure and clerkship examination. We describe the introduction of the Core Learning Objective (CLO) educational model at the University of Chicago Section of Urology. This model is designed to provide an efficient exposure to and evaluation of core clerkship learning objectives. The CLO model has been successfully initiated, focusing on both technical and clinical skill sets. The proposed model has been introduced with positive initial results and should allow for an efficient approach to the teaching and evaluation of core objectives in clerkship education.

EUVL mask dual pods to be used for mask shipping and handling in exposure tools

NASA Astrophysics Data System (ADS)

Gomei, Yoshio; Ota, Kazuya; Lystad, John; Halbmair, Dave; He, Long

2007-03-01

The concept of Extreme Ultra-Violet Lithography (EUVL) mask dual pods is proposed for use in both mask shipping and handling in exposure tools. The inner pod was specially designed to protect masks from particle contamination during shipping from mask houses to wafer factories. It can be installed in a load-lock chamber of exposure tools and evacuated while holding the mask inside. The inner pod upper cover is removed just before the mask is installed to a mask stage. Prototypes were manufactured and tested for shipping and for vacuum cycling. We counted particle adders through these actions with a detectable level of 54 nm and up. The adder count was close to zero, or we can say that the obtained result is within the noise level of our present evaluation environment. This indicates that the present concept is highly feasible for EUVL mask shipping and handling in exposure tools.

A Call for a Multifaceted Approach to Language Learning Motivation Research: Combining Complexity, Humanistic, and Critical Perspectives

ERIC Educational Resources Information Center

Pigott, Julian

2012-01-01

In this paper I give an overview of recent developments in the L2 motivation field, in particular the movement away from quantitative, questionnaire-based methodologies toward smaller-scale qualitative studies incorporating concepts from complexity theory. While complexity theory provides useful concepts for exploring motivation in new ways, it…

Expanding on Successful Concepts, Models, and Organization

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

Teeguarden, Justin G.; Tan, Yu-Mei; Edwards, Stephen W.

In her letter to the editor1 regarding our recent Feature Article “Completing the Link between Exposure Science and Toxicology for Improved Environmental Health Decision Making: The Aggregate Exposure Pathway Framework” 2, Dr. von Göetz expressed several concerns about terminology, and the perception that we propose the replacement of successful approaches and models for exposure assessment with a concept. We are glad to have the opportunity to address these issues here. If the goal of the AEP framework was to replace existing exposure models or databases for organizing exposure data with a concept, we would share Dr. von Göetz concerns. Instead,more » the outcome we promote is broader use of an organizational framework for exposure science. The framework would support improved generation, organization, and interpretation of data as well as modeling and prediction, not replacement of models. The field of toxicology has seen the benefits of wide use of one or more organizational frameworks (e.g., mode and mechanism of action, adverse outcome pathway). These frameworks influence how experiments are designed, data are collected, curated, stored and interpreted and ultimately how data are used in risk assessment. Exposure science is poised to similarly benefit from broader use of a parallel organizational framework, which Dr. von Göetz correctly points out, is currently used in the exposure modeling community. In our view, the concepts used so effectively in the exposure modeling community, expanded upon in the AEP framework, could see wider adoption by the field as a whole. The value of such a framework was recognized by the National Academy of Sciences.3 Replacement of models, databases, or any application with the AEP framework was not proposed in our article. The positive role broader more consistent use of such a framework might have in enabling and advancing “general activities such as data acquisition, organization…,” and exposure modeling was discussed in some detail. Like Dr. von Göetz, we recognized the challenges associated with acceptance of the terminology, definitions, and structure proposed in the paper. To address these challenges, an expert workshop was held in May, 2016 to consider and revise the “basic elements” outlined in the paper. The attendees produced revisions to the terminology (e.g., key events) that align with terminology currently in use in the field. We were also careful in our paper to acknowledge a point raised by Dr. von Göetz, that the term AEP implies aggregation, providing these clarifications: “The simplest form of an AEP represents a single source and a single pathway and may more commonly be referred to as an exposure pathway,”; and “An aggregate exposure pathway may represent multiple sources and transfer through single pathways to the TSE, single sources and transfer through multiple pathways to the target site exposure (TSE), or any combination of these.” These clarifications address the concern that the AEP term is not accurate or logical, and further expands upon the word “aggregate” in a broader context. Our use of AEP is consistent with the definition for “aggregate exposure”, which refers to the combined exposures to a single chemical across multiple routes and pathways.3 The AEP framework embraces existing methods for collection, prediction, organization, and interpretation of human and ecological exposure data cited by Dr. von Göetz. We remain hopeful that wider recognition and use of an organizing concept for exposure information across the exposure science, toxicology and epidemiology communities advances the development of the kind of infrastructure and models Dr. von Göetz discusses. This outcome would be a step forward, rather than a step backward.« less

Wh-Questions in Child L2 French: Derivational Complexity and Its Interactions with L1 Properties, Length of Exposure, Age of Exposure, and the Input

ERIC Educational Resources Information Center

Prévost, Philippe; Strik, Nelleke; Tuller, Laurie

2014-01-01

This study investigates how derivational complexity interacts with first language (L1) properties, second language (L2) input, age of first exposure to the target language, and length of exposure in child L2 acquisition. We compared elicited production of "wh"-questions in French in two groups of 15 participants each, one with L1 English…

Why is metal bioaccumulation so variable? Biodynamics as a unifying concept

USGS Publications Warehouse

Luoma, Samuel N.; Rainbow, Philip S.

2005-01-01

Ecological risks from metal contaminants are difficult to document because responses differ among species, threats differ among metals, and environmental influences are complex. Unifying concepts are needed to better tie together such complexities. Here we suggest that a biologically based conceptualization, the biodynamic model, provides the necessary unification for a key aspect in risk:  metal bioaccumulation (internal exposure). The model is mechanistically based, but empirically considers geochemical influences, biological differences, and differences among metals. Forecasts from the model agree closely with observations from nature, validating its basic assumptions. The biodynamic metal bioaccumulation model combines targeted, high-quality geochemical analyses from a site of interest with parametrization of key physiological constants for a species from that site. The physiological parameters include metal influx rates from water, influx rates from food, rate constants of loss, and growth rates (when high). We compiled results from 15 publications that forecast species-specific bioaccumulation, and compare the forecasts to bioaccumulation data from the field. These data consider concentrations that cover 7 orders of magnitude. They include 7 metals and 14 species of animals from 3 phyla and 11 marine, estuarine, and freshwater environments. The coefficient of determination (R2) between forecasts and independently observed bioaccumulation from the field was 0.98. Most forecasts agreed with observations within 2-fold. The agreement suggests that the basic assumptions of the biodynamic model are tenable. A unified explanation of metal bioaccumulation sets the stage for a realistic understanding of toxicity and ecological effects of metals in nature.

The risk of infertility and delayed conception associated with exposures in the Danish workplace

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

Rachootin, P.; Olsen, J.

1983-05-01

The association between infertility and a number of occupations and occupational exposures was examined in a case-control study utilizing data collected from medical records and mailed questionnaires. The results suggest that male exposure to heat and female exposure to noise, textile dyes and lead, mercury, and cadmium are associated with infertility. Further research is needed to examine the entire spectrum of abnormal reproductive and developmental outcomes of exposure to these agents and to identify their full effects.

Students' conceptual performance on synthesis physics problems with varying mathematical complexity

NASA Astrophysics Data System (ADS)

Ibrahim, Bashirah; Ding, Lin; Heckler, Andrew F.; White, Daniel R.; Badeau, Ryan

2017-06-01

A body of research on physics problem solving has focused on single-concept problems. In this study we use "synthesis problems" that involve multiple concepts typically taught in different chapters. We use two types of synthesis problems, sequential and simultaneous synthesis tasks. Sequential problems require a consecutive application of fundamental principles, and simultaneous problems require a concurrent application of pertinent concepts. We explore students' conceptual performance when they solve quantitative synthesis problems with varying mathematical complexity. Conceptual performance refers to the identification, follow-up, and correct application of the pertinent concepts. Mathematical complexity is determined by the type and the number of equations to be manipulated concurrently due to the number of unknowns in each equation. Data were collected from written tasks and individual interviews administered to physics major students (N =179 ) enrolled in a second year mechanics course. The results indicate that mathematical complexity does not impact students' conceptual performance on the sequential tasks. In contrast, for the simultaneous problems, mathematical complexity negatively influences the students' conceptual performance. This difference may be explained by the students' familiarity with and confidence in particular concepts coupled with cognitive load associated with manipulating complex quantitative equations. Another explanation pertains to the type of synthesis problems, either sequential or simultaneous task. The students split the situation presented in the sequential synthesis tasks into segments but treated the situation in the simultaneous synthesis tasks as a single event.

Feasibility of Telementoring for Microneurosurgical Procedures Using a Microscope: A Proof-of-Concept Study.

PubMed

Ladd, Bryan M; Tackla, Ryan D; Gupte, Akshay; Darrow, David; Sorenson, Jeffery; Zuccarello, Mario; Grande, Andrew W

2017-03-01

Our pilot study evaluated the effectiveness of our telementoring-telescripting model to facilitate seamless communication between surgeons while the operating surgeon is using a microscope. As a first proof of concept, 4 students identified 20 anatomic landmarks on a dry human skull with or without telementoring guidance. To assess the ability to communicate operative information, a senior neurosurgery resident evaluated the student's ability and timing to complete a stepwise craniotomy on a cadaveric head, with and without telementoring guidance; a second portion included exposure of the anterior circulation. The mentor was able to annotate directly onto the operator's visual field, which was visible to the operator without looking away from the binocular view. The students showed that they were familiar with half (50% ± 10%) of the structures for identification and none was familiar with the steps to complete a craniotomy before using our system. With the guidance of a remote surgeon projected into the visual field of the microscope, the students were able to correctly identify 100% of the structures and complete a craniotomy. Our system also proved effective in guiding a more experienced neurosurgery resident through complex operative steps associated with exposure of the anterior circulation. Our pilot study showed a platform feasible in providing effective operative direction to inexperienced operators while operating using a microscope. A remote mentor was able to view the visual field of the microscope, annotate on the visual stream, and have the annotated stream appear in the binocular view for the operating mentee. Copyright © 2016 Elsevier Inc. All rights reserved.

Perspectives for integrating human and environmental exposure assessments.

PubMed

Ciffroy, P; Péry, A R R; Roth, N

2016-10-15

Integrated Risk Assessment (IRA) has been defined by the EU FP7 HEROIC Coordination action as "the mutual exploitation of Environmental Risk Assessment for Human Health Risk Assessment and vice versa in order to coherently and more efficiently characterize an overall risk to humans and the environment for better informing the risk analysis process" (Wilks et al., 2015). Since exposure assessment and hazard characterization are the pillars of risk assessment, integrating Environmental Exposure assessment (EEA) and Human Exposure assessment (HEA) is a major component of an IRA framework. EEA and HEA typically pursue different targets, protection goals and timeframe. However, human and wildlife species also share the same environment and they similarly inhale air and ingest water and food through often similar overlapping pathways of exposure. Fate models used in EEA and HEA to predict the chemicals distribution among physical and biological media are essentially based on common properties of chemicals, and internal concentration estimations are largely based on inter-species (i.e. biota-to-human) extrapolations. Also, both EEA and HEA are challenged by increasing scientific complexity and resources constraints. Altogether, these points create the need for a better exploitation of all currently existing data, experimental approaches and modeling tools and it is assumed that a more integrated approach of both EEA and HEA may be part of the solution. Based on the outcome of an Expert Workshop on Extrapolations in Integrated Exposure Assessment organized by the HEROIC project in January 2014, this paper identifies perspectives and recommendations to better harmonize and extrapolate exposure assessment data, models and methods between Human Health and Environmental Risk Assessments to support the further development and promotion of the concept of IRA. Ultimately, these recommendations may feed into guidance showing when and how to apply IRA in the regulatory decision-making process for chemicals. Copyright © 2015 Elsevier B.V. All rights reserved.

Panarchy: Theory and Application

EPA Science Inventory

The concept of panarchy was introduced by Gunderson et al. (1995) and refined by Gunderson and Holling (2002) as a heuristic model to help explain complex changes in ecosystem processes and structures within and across scales of organization. The concept takes a complex systems a...

Racial microstressors, racial self-concept, and depressive symptoms among male African Americans during the transition to adulthood.

PubMed

Kogan, Steven M; Yu, Tianyi; Allen, Kimberly A; Brody, Gene H

2015-04-01

Racial discrimination is a pervasive stressor that can undermine mental health among African American youth and young adults. Several studies identify links between racial discrimination and depressive symptoms; however, this research base does not focus on male African American youth who experience significant racism-related stress during the transition to young adulthood. Moreover, few prospective studies consider significant confounding variables that affect exposure to and perception of discriminatory treatment. In response to this need, we examined the effect of exposure to racial discrimination from ages 16 to 18 on depressive symptoms among male African Americans at age 20. Racial self-concept, one's sense of positivity about one's race, was examined as a mediator and self-control as a moderator. Hypotheses were tested with 222 participants, age 16 at baseline and age 20 at the endpoint. Participants provided self-report data at five time points. Exposure to racial discrimination from ages 16 to 18 predicted depressive symptoms at age 20, net of confounding influences. Racial self-concept mediated this effect. Self-control moderated the influence of discrimination on racial self-concept. This study underscores the salience of racial discrimination in the development of depressive symptoms among African American male youth and the clinical utility of interventions targeting racial pride and self-control.

The early origins of obesity and insulin resistance: timing, programming and mechanisms.

PubMed

Nicholas, L M; Morrison, J L; Rattanatray, L; Zhang, S; Ozanne, S E; McMillen, I C

2016-02-01

Maternal obesity is associated with an increased risk of developing gestational diabetes mellitus and it also results in an increased risk of giving birth to a large baby with increased fat mass. Furthermore, it is also contributes to an increased risk of obesity and insulin resistance in the offspring in childhood, adolescence and adult life. It has been proposed that exposure to maternal obesity may therefore result in an 'intergenerational cycle' of obesity and insulin resistance. There is significant interest in whether exposure to maternal obesity around the time of conception alone contributes directly to poor metabolic outcomes in the offspring and whether dieting in the obese mother before pregnancy or around the time of conception has metabolic benefits for the offspring. This review focusses on experimental and clinical studies that have investigated the specific impact of exposure to maternal obesity during the periconceptional period alone or extending beyond conception on adipogenesis, lipogenesis and on insulin signalling pathways in the fat, liver and muscle of the offspring. Findings from these studies highlight the need for a better evidence base for the development of dietary interventions in obese women before pregnancy and around the time of conception to maximize the metabolic benefits and minimize the metabolic costs for the next generation.

From the exposome to mechanistic understanding of chemical ...

EPA Pesticide Factsheets

BACKGROUND: Current definitions of the exposome expand beyond the initial idea to consider the totality of exposure and aim to relate to biological effects. While the exposome has been established for human health, its principles can be extended to include broader ecological issues. The assessment of exposure is tightly interlinked with hazard assessment. OBJECTIVES: We explore if mechanistic understanding of the causal links between exposure and adverse effects on human health and the environment can be improved by integrating the exposome approach with the adverse outcome pathway (AOP) concept - a framework to structure and organize the sequence of toxicological events from an initial molecular interaction of a chemical to an adverse outcome.METHODS: This review was informed by a Workshop organized by the Integrated Project EXPOSOME at the UFZ Helmholtz Centre for Environmental Research in Leipzig, Germany. DISCUSSION: The exposome encompasses all chemicals, including exogenous chemicals and endogenous compounds that are produced in response to external factors. By complementing the exposome research with the AOP concept, we can achieve a better mechanistic understanding, weigh the importance of various components of the exposome, and determine primary risk drivers. The ability to interpret multiple exposures and mixture effects at the mechanistic level requires a more holistic approach facilitated by the exposome concept.CONCLUSION: Incorporating the AOP conc

The Automated Dynamic Directed Evolution Chamber: A Tool for Studying Extremophile-Environment Interactions in Real Time

NASA Astrophysics Data System (ADS)

Wong, N.; Grace, J. M.; Liang, J.; Owyang, S.; Storrs, A.; Zhou, J.; Rothschild, L. J.; Gentry, D.

2014-12-01

Life acclimated to harsh conditions is frequently difficult to study using normal lab techniques and conventional equipment. Simplified studies using in-lab 'simulated' extreme environments, such as UV bulbs or cold blocks, are manually intensive, error-prone, and lose many complexities of the microbe/environment interaction. We have built a prototype instrument to address this dilemma by allowing automated iterations of microbial cultures to be subject to combinations of modular environmental pressures such as heat, radiation, and chemical exposure. The presence of multiple sensors allows the state of the culture and internal environment to be continuously monitored and adjusted in response.Our first prototype showed successful iterations of microbial growth and thermal exposure. Our second prototype, presented here, performs an demonstration of repeated exposure of Escherichia coli to ultraviolet radiation, a well-established procedure. As the E. coli becomes more resistant to ultraviolet radiation, the device detects their increased survival and growth and increases the dosage accordingly. Calibration data for the instrument was generated by performing the same proof-of-concept exposure experiment, at a smaller scale, by hand. Current performance data indicates that our finalized instrument will have the ability to run hundreds of iterations with multiple selection pressures. The automated sensing and adaptive exposure that the device provides will inform the challenges of managing and culturing life tailored to uncommon environmental stresses. We have designed this device to be flexible, extensible, low-cost and easy to reproduce. We hope that it enter wide use as a tool for conducting scalable studies of the interaction between extremophiles and multiple environmental stresses, and potentially for generating artificial extremophiles as analogues for life we might find in extreme environments here on Earth or elsewhere.

Fitness and Individuality in Complex Life Cycles.

PubMed

Herron, Matthew D

2016-12-01

Complex life cycles are common in the eukaryotic world, and they complicate the question of how to define individuality. Using a bottom-up, gene-centric approach, I consider the concept of fitness in the context of complex life cycles. I analyze the fitness effects of an allele (or a trait) on different biological units within a complex life history and how these effects drive evolutionary change within populations. Based on these effects, I attempt to construct a concept of fitness that accurately predicts evolutionary change in the context of complex life cycles.

Modeling Environment for Total Risk-1A

EPA Science Inventory

MENTOR-1A uses an integrated, mechanistically consistent source-to-dose modeling framework to quantify inhalation exposure and dose for individuals and/or populations due to co-occurring air pollutants. It uses the "One Atmosphere" concept to characterize simultaneous exposures t...

PROSPECTIVE PREGNANCY STUDY DESIGNS FOR ASSESSING REPRODUCTIVE AND DEVELOPMENTAL TOXICANTS

EPA Science Inventory

Of late, there is increasing recognition that exposures before, at or shortly after conception have life-long implications for human reproduction and development. Despite this evolving literature, few research initiatives have been designed to empirically evaluate exposures durin...

Concept Maps for Improved Science Reasoning and Writing: Complexity Isn't Everything.

PubMed

Dowd, Jason E; Duncan, Tanya; Reynolds, Julie A

2015-01-01

A pervasive notion in the literature is that complex concept maps reflect greater knowledge and/or more expert-like thinking than less complex concept maps. We show that concept maps used to structure scientific writing and clarify scientific reasoning do not adhere to this notion. In an undergraduate course for thesis writers, students use concept maps instead of traditional outlines to define the boundaries and scope of their research and to construct an argument for the significance of their research. Students generate maps at the beginning of the semester, revise after peer review, and revise once more at the end of the semester. Although some students revised their maps to make them more complex, a significant proportion of students simplified their maps. We found no correlation between increased complexity and improved scientific reasoning and writing skills, suggesting that sometimes students simplify their understanding as they develop more expert-like thinking. These results suggest that concept maps, when used as an intervention, can meet the varying needs of a diverse population of student writers. © 2015 J. E. Dowd et al. CBE—Life Sciences Education © 2015 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). 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).

Precision-Based Item Selection for Exposure Control in Computerized Adaptive Testing

ERIC Educational Resources Information Center

Carroll, Ian A.

2017-01-01

Item exposure control is, relative to adaptive testing, a nascent concept that has emerged only in the last two to three decades on an academic basis as a practical issue in high-stakes computerized adaptive tests. This study aims to implement a new strategy in item exposure control by incorporating the standard error of the ability estimate into…

Using Stereoscopy to Teach Complex Biological Concepts

ERIC Educational Resources Information Center

Ferdig, Richard; Blank, James; Kratcoski, Annette; Clements, Robert

2015-01-01

Used effectively, stereoscopic three-dimensional (3D) technologies can engage students with complex disciplinary content as they are presented with informative representations of abstract concepts. In addition, preliminary evidence suggests that stereoscopy may enhance learning and retention in some educational settings. Biological concepts…

Unravelling the differences between complexity and frailty in old age: findings from a constructivist grounded theory study.

PubMed

McGeorge, S J

2011-02-01

UK health policy has used the terms 'frailty' and 'complexity' synonymously but there is no common definition for either. Understanding these concepts is important if demand for health care created by the increasing number of older people in society is to be managed effectively. This paper explores some findings from a study into how mental health nurses who work with older people construct and operationalize the concept of 'age-related complexity'. Constructivist grounded theory was used. Audio-taped interviews were undertaken with 13 registered nurses and were analysed using a constant comparative method. This paper addresses the relationship between frailty and complexity, which was identified as a theme within the category 'dynamic complexity'. The findings suggest that nurses understand important differences between the two concepts. Frailty is exclusively used to describe physical states while complexity is a more encompassing term that has resonance and relevance in mental health services. The dynamic nature of complexity means that older people can become both more and less complex and this has implications for nursing practice that require further study. © 2010 Blackwell Publishing.

An emergentist vs a linear approach to social change processes: a gender look in contemporary India between modernity and Hindu tradition.

PubMed

Condorelli, Rosalia

2015-01-01

Using Census of India data from 1901 to 2011 and national and international reports on women's condition in India, beginning with sex ratio trends according to regional distribution up to female infanticides and sex-selective abortions and dowry deaths, this study examines the sociological aspects of the gender imbalance in modern contemporary India. Gender inequality persistence in India proves that new values and structures do not necessarily lead to the disappearance of older forms, but they can co-exist with mutual adaptations and reinforcements. Data analysis suggests that these unexpected combinations are not comprehensible in light of a linear concept of social change which is founded, in turn, on a concept of social systems as linear interaction systems that relate to environmental perturbations according to proportional cause and effect relationships. From this perspective, in fact, behavioral attitudes and interaction relationships should be less and less proportionally regulated by traditional values and practices as exposure to modernizing influences increases. And progressive decreases should be found in rates of social indicators of gender inequality like dowry deaths (the inverse should be found in sex ratio trends). However, data does not confirm these trends. This finding leads to emphasize a new theoretical and methodological approach toward social systems study, namely the conception of social systems as complex adaptive systems and the consequential emergentist, nonlinear conception of social change processes. Within the framework of emergentist theory of social change is it possible to understand the lasting strength of the patriarchal tradition and its problematic consequences in the modern contemporary India.

Enhanced Systemic Understanding of the Information Environment in Complex Crisis Management - Analytical Concept, Version 1.0

DTIC Science & Technology

2010-10-22

4. TITLE AND SUBTITLE Enhanced Systemic Understanding of the Information Environment in Complex Crisis Management Analytical Concept, Version 1.0...Email: schmidtb@iabg.de UNCLASSIFIED FOR PUBLIC RELEASE – Enhanced Systemic Understanding of the Information Environment in Complex Crisis ...multinational crisis management and the security sector about the significance and characteristics of the information environment. The framework is

Early-life metal exposure and schizophrenia: A proof-of-concept study using novel tooth-matrix biomarkers.

PubMed

Modabbernia, A; Velthorst, E; Gennings, C; De Haan, L; Austin, C; Sutterland, A; Mollon, J; Frangou, S; Wright, R; Arora, M; Reichenberg, A

2016-08-01

Despite evidence for the effects of metals on neurodevelopment, the long-term effects on mental health remain unclear due to methodological limitations. Our objective was to determine the feasibility of studying metal exposure during critical neurodevelopmental periods and to explore the association between early-life metal exposure and adult schizophrenia. We analyzed childhood-shed teeth from nine individuals with schizophrenia and five healthy controls. We investigated the association between exposure to lead (Pb(2+)), manganese (Mn(2+)), cadmium (Cd(2+)), copper (Cu(2+)), magnesium (Mg(2+)), and zinc (Zn(2+)), and schizophrenia, psychotic experiences, and intelligence quotient (IQ). We reconstructed the dose and timing of early-life metal exposures using laser ablation inductively coupled plasma mass spectrometry. We found higher early-life Pb(2+) exposure among patients with schizophrenia than controls. The differences in log Mn(2+) and log Cu(2+) changed relatively linearly over time to postnatal negative values. There was a positive correlation between early-life Pb(2+) levels and psychotic experiences in adulthood. Moreover, we found a negative correlation between Pb(2+) levels and adult IQ. In our proof-of-concept study, using tooth-matrix biomarker that provides direct measurement of exposure in the fetus and newborn, we provide support for the role of metal exposure during critical neurodevelopmental periods in psychosis. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Integrated therapy safety management system

PubMed Central

Podtschaske, Beatrice; Fuchs, Daniela; Friesdorf, Wolfgang

2013-01-01

Aims The aim is to demonstrate the benefit of the medico-ergonomic approach for the redesign of clinical work systems. Based on the six layer model, a concept for an ‘integrated therapy safety management’ is drafted. This concept could serve as a basis to improve resilience. Methods The concept is developed through a concept-based approach. The state of the art of safety and complexity research in human factors and ergonomics forms the basis. The findings are synthesized to a concept for ‘integrated therapy safety management’. The concept is applied by way of example for the ‘medication process’ to demonstrate its practical implementation. Results The ‘integrated therapy safety management’ is drafted in accordance with the six layer model. This model supports a detailed description of specific work tasks, the corresponding responsibilities and related workflows at different layers by using the concept of ‘bridge managers’. ‘Bridge managers’ anticipate potential errors and monitor the controlled system continuously. If disruptions or disturbances occur, they respond with corrective actions which ensure that no harm results and they initiate preventive measures for future procedures. The concept demonstrates that in a complex work system, the human factor is the key element and final authority to cope with the residual complexity. The expertise of the ‘bridge managers’ and the recursive hierarchical structure results in highly adaptive clinical work systems and increases their resilience. Conclusions The medico-ergonomic approach is a highly promising way of coping with two complexities. It offers a systematic framework for comprehensive analyses of clinical work systems and promotes interdisciplinary collaboration. PMID:24007448

The Affordable Care Act: a case study for understanding and applying complexity concepts to health care reform.

PubMed

Larkin, D Justin; Swanson, R Chad; Fuller, Spencer; Cortese, Denis A

2016-02-01

The current health system in the United States is the result of a history of patchwork policy decisions and cultural assumptions that have led to persistent contradictions in practice, gaps in coverage, unsustainable costs, and inconsistent outcomes. In working toward a more efficient health system, understanding and applying complexity science concepts will allow for policy that better promotes desired outcomes and minimizes the effects of unintended consequences. This paper will consider three applied complexity science concepts in the context of the Patient Protection and Affordable Care Act (PPACA): developing a shared vision around reimbursement for value, creating an environment for emergence through simple rules, and embracing transformational leadership at all levels. Transforming the US health system, or any other health system, will be neither easy nor quick. Applying complexity concepts to health reform efforts, however, will facilitate long-term change in all levels, leading to health systems that are more effective, efficient, and equitable. © 2014 John Wiley & Sons, Ltd.

Environmental management on the basis of Complex Regional Indicators Concept: case of the Murmansk region

NASA Astrophysics Data System (ADS)

Kozlov, A.; Gutman, S.; Zaychenko, I.; Rytova, E.; Nijinskaya, P.

2015-09-01

The article presents an approach to sustainable environmental development of the Murmansk region of the Russian Federation based on the complex regional indicators as a transformation of a balance scorecard method. The peculiarities of Murmansk region connected with sustainable environmental development are described. The complex regional indicators approach allows to elaborate the general concept of complex regional development taking into consideration economic and non-economic factors with the focus on environmental aspects, accumulated environmental damage in particular. General strategic chart of sustainable environmental development of the Murmansk region worked out on the basis of complex regional indicators concept is composed. The key target indicators of sustainable ecological development of the Murmansk region are presented for the following strategic chart components: regional finance; society and market; industry and entrepreneurship; training, development and innovations. These charts are to be integrated with international environmental monitoring systems.

Biomonitoring - An Exposure Science Tool for Exposure and Risk Assessment

EPA Science Inventory

Biomonitoring studies of environmental stressors are useful for confirming exposures, estimating dose levels, and evaluating human health risks. However, the complexities of exposure-biomarker and biomarker-response relationships have limited the use of biomarkers in exposure sc...

A Complex Exposure History of the Gold Basin L4-Chondrite Shower from Cosmogenic Radionuclides and Noble Gases

NASA Technical Reports Server (NTRS)

Welten, K. C.; Nishiizumi, K.; Caffee, M. W.; Masarik, J.; Wieler, R.

2001-01-01

Cosmogenic radionuclides and noble gases in samples of the Gold Basin L-chondrite shower indicate a complex exposure history, with a first stage exposure on the parent body, followed by a second stage of approx. 19 Myr in a meteoroid 3-4 m in radius. Additional information is contained in the original extended abstract.

Levels of blood lead and urinary cadmium in industrial complex residents in Ulsan.

PubMed

Kim, Sang Hoon; Kim, Yang Ho; An, Hyun Chan; Sung, Joo Hyun; Sim, Chang Sun

2017-01-01

Populations neighboring industrial complexes are at an increased health risk, due to constant exposure to various potentially hazardous compounds released during industrial production activity. Although there are many previous studies that focus on occupational exposure to heavy metals, studies that focused on environmental exposure to lead and cadmium are relatively rare. The purpose of this study is to evaluate the extent of the environmental exposure of heavy metals in residents of industrial area. Four areas in close proximity to the Ulsan petrochemical industrial complex and the Onsan national industrial complex were selected to be included in the exposure group, and an area remotely located from these industrial complexes was selected as the non-exposure group. Among the residents of our study areas, a total of 1573 subjects aged 20 years and older were selected and all study subjects completed a written questionnaire. Blood and urine samples were obtained from about one third of the subjects (465 subjects) who provided informed consent for biological sample collection. Total 429 subjects (320 subjects from exposure area, 109 subjects from non-exposure area) were included in final analysis. The geometric mean blood lead level among the subjects in the exposed group was 2.449 μg/dL, which was significantly higher than the non-exposure group's level of 2.172 μg/dL. Similarly, the geometric mean urine cadmium levels between the two groups differed significantly, at 1.077 μg/g Cr. for the exposed group, and 0.709 μg/g Cr. for the non-exposure group. In a multiple linear regression analysis to determine the relationship between blood lead level and related factors, the results showed that blood lead level had a significant positive correlation with age, the male, exposure area, and non-drinkers. In the same way, urine cadmium level was positively correlated with age, the female, exposure area, and smokers. This study found that blood lead levels and urine cadmium levels were significantly higher among the residents of industrial areas than among the non-exposure area residents, which is thought to be due to the difference in environmental exposure of lead and cadmium. Furthermore, it was clear that at a low level of exposure, differences in blood lead or urine cadmium levels based on age, gender, and smoking status were greater than the differences based on area of residence. Therefore, when evaluating heavy metal levels in the body at a low level of exposure, age, gender, and smoking status must be adjusted, as they are significant confounding factors.

A Topical Overview of Cumulative Risk Assessment Concepts, Methods, and Applications (2007–2016)

EPA Science Inventory

Cumulative risk assessments (CRAs) address combined risks from exposures to multiple chemical and nonchemical stressors and may focus on vulnerable communities or populations. Significant contributions have been made to the development of concepts, methods, and applications for C...

Alpha-Particle-Induced Complex Chromosome Exchanges Transmitted through Extra-Thymic Lymphopoiesis In Vitro Show Evidence of Emerging Genomic Instability

PubMed Central

Sumption, Natalia; Goodhead, Dudley T.; Anderson, Rhona M.

2015-01-01

Human exposure to high-linear energy transfer α-particles includes environmental (e.g. radon gas and its decay progeny), medical (e.g. radiopharmaceuticals) and occupational (nuclear industry) sources. The associated health risks of α-particle exposure for lung cancer are well documented however the risk estimates for leukaemia remain uncertain. To further our understanding of α-particle effects in target cells for leukaemogenesis and also to seek general markers of individual exposure to α-particles, this study assessed the transmission of chromosomal damage initially-induced in human haemopoietic stem and progenitor cells after exposure to high-LET α-particles. Cells surviving exposure were differentiated into mature T-cells by extra-thymic T-cell differentiation in vitro. Multiplex fluorescence in situ hybridisation (M-FISH) analysis of naïve T-cell populations showed the occurrence of stable (clonal) complex chromosome aberrations consistent with those that are characteristically induced in spherical cells by the traversal of a single α-particle track. Additionally, complex chromosome exchanges were observed in the progeny of irradiated mature T-cell populations. In addition to this, newly arising de novo chromosome aberrations were detected in cells which possessed clonal markers of α-particle exposure and also in cells which did not show any evidence of previous exposure, suggesting ongoing genomic instability in these populations. Our findings support the usefulness and reliability of employing complex chromosome exchanges as indicators of past or ongoing exposure to high-LET radiation and demonstrate the potential applicability to evaluate health risks associated with α-particle exposure. PMID:26252014

Assessing correlations between geological hazards and health outcomes: Addressing complexity in medical geology.

PubMed

Wardrop, Nicola Ann; Le Blond, Jennifer Susan

2015-11-01

The field of medical geology addresses the relationships between exposure to specific geological characteristics and the development of a range of health problems: for example, long-term exposure to arsenic in drinking water can result in the development of skin conditions and cancers. While these relationships are well characterised for some examples, in others there is a lack of understanding of the specific geological component(s) triggering disease onset, necessitating further research. This paper aims to highlight several important complexities in geological exposures and the development of related diseases that can create difficulties in the linkage of exposure and health outcome data. Several suggested approaches to deal with these complexities are also suggested. Long-term exposure and lengthy latent periods are common characteristics of many diseases related to geological hazards. In combination with long- or short-distance migrations over an individual's life, daily or weekly movement patterns and small-scale spatial heterogeneity in geological characteristics, it becomes problematic to appropriately assign exposure measurements to individuals. The inclusion of supplementary methods, such as questionnaires, movement diaries or Global Positioning System (GPS) trackers can support medical geology studies by providing evidence for the most appropriate exposure measurement locations. The complex and lengthy exposure-response pathways involved, small-distance spatial heterogeneity in environmental components and a range of other issues mean that interdisciplinary approaches to medical geology studies are necessary to provide robust evidence. Copyright © 2015. Published by Elsevier Ltd.

Response of single bacterial cells to stress gives rise to complex history dependence at the population level

PubMed Central

Mathis, Roland; Ackermann, Martin

2016-01-01

Most bacteria live in ever-changing environments where periods of stress are common. One fundamental question is whether individual bacterial cells have an increased tolerance to stress if they recently have been exposed to lower levels of the same stressor. To address this question, we worked with the bacterium Caulobacter crescentus and asked whether exposure to a moderate concentration of sodium chloride would affect survival during later exposure to a higher concentration. We found that the effects measured at the population level depended in a surprising and complex way on the time interval between the two exposure events: The effect of the first exposure on survival of the second exposure was positive for some time intervals but negative for others. We hypothesized that the complex pattern of history dependence at the population level was a consequence of the responses of individual cells to sodium chloride that we observed: (i) exposure to moderate concentrations of sodium chloride caused delays in cell division and led to cell-cycle synchronization, and (ii) whether a bacterium would survive subsequent exposure to higher concentrations was dependent on the cell-cycle state. Using computational modeling, we demonstrated that indeed the combination of these two effects could explain the complex patterns of history dependence observed at the population level. Our insight into how the behavior of single cells scales up to processes at the population level provides a perspective on how organisms operate in dynamic environments with fluctuating stress exposure. PMID:26960998

Comparison of different approaches of estimating effective dose from reported exposure data in 3D imaging with interventional fluoroscopy systems

NASA Astrophysics Data System (ADS)

Svalkvist, Angelica; Hansson, Jonny; Bâth, Magnus

2014-03-01

Three-dimensional (3D) imaging with interventional fluoroscopy systems is today a common examination. The examination includes acquisition of two-dimensional projection images, used to reconstruct section images of the patient. The aim of the present study was to investigate the difference in resulting effective dose obtained using different levels of complexity in calculations of effective doses from these examinations. In the study the Siemens Artis Zeego interventional fluoroscopy system (Siemens Medical Solutions, Erlangen, Germany) was used. Images of anthropomorphic chest and pelvis phantoms were acquired. The exposure values obtained were used to calculate the resulting effective doses from the examinations, using the computer software PCXMC (STUK, Helsinki, Finland). The dose calculations were performed using three different methods: 1. using individual exposure values for each projection image, 2. using the mean tube voltage and the total DAP value, evenly distributed over the projection images, and 3. using the mean kV and the total DAP value, evenly distributed over smaller selection of projection images. The results revealed that the difference in resulting effective dose between the first two methods was smaller than 5%. When only a selection of projection images were used in the dose calculations the difference increased to over 10%. Given the uncertainties associated with the effective dose concept, the results indicate that dose calculations based on average exposure values distributed over a smaller selection of projection angles can provide reasonably accurate estimations of the radiation doses from 3D imaging using interventional fluoroscopy systems.

Complex adaptive systems: concept analysis.

PubMed

Holden, Lela M

2005-12-01

The aim of this paper is to explicate the concept of complex adaptive systems through an analysis that provides a description, antecedents, consequences, and a model case from the nursing and health care literature. Life is more than atoms and molecules--it is patterns of organization. Complexity science is the latest generation of systems thinking that investigates patterns and has emerged from the exploration of the subatomic world and quantum physics. A key component of complexity science is the concept of complex adaptive systems, and active research is found in many disciplines--from biology to economics to health care. However, the research and literature related to these appealing topics have generated confusion. A thorough explication of complex adaptive systems is needed. A modified application of the methods recommended by Walker and Avant for concept analysis was used. A complex adaptive system is a collection of individual agents with freedom to act in ways that are not always totally predictable and whose actions are interconnected. Examples include a colony of termites, the financial market, and a surgical team. It is often referred to as chaos theory, but the two are not the same. Chaos theory is actually a subset of complexity science. Complexity science offers a powerful new approach--beyond merely looking at clinical processes and the skills of healthcare professionals. The use of complex adaptive systems as a framework is increasing for a wide range of scientific applications, including nursing and healthcare management research. When nursing and other healthcare managers focus on increasing connections, diversity, and interactions they increase information flow and promote creative adaptation referred to as self-organization. Complexity science builds on the rich tradition in nursing that views patients and nursing care from a systems perspective.

Positive deviance: an elegant solution to a complex problem.

PubMed

Lindberg, Curt; Clancy, Thomas R

2010-04-01

As systems evolve over time, their natural tendency is to become increasingly more complex. Studies in the field of complex systems have generated new perspectives on management in social organizations such as hospitals. Much of this research appears as a natural extension of the cross-disciplinary field of systems theory. This is the 13th in a series of articles applying complex systems science to the traditional management concepts of planning, organizing, directing, coordinating, and controlling. This article provides one example of how concepts taken from complex systems theory can be applied to real-world problems facing nurses today.

Divergent effects of activating thoughts of God on self-regulation.

PubMed

Laurin, Kristin; Kay, Aaron C; Fitzsimons, Gráinne M

2012-01-01

Despite the cultural ubiquity of ideas and images related to God, relatively little is known about the effects of exposure to God representations on behavior. Specific depictions of God differ across religions, but common to most is that God is (a) an omnipotent, controlling force and (b) an omniscient, all-knowing being. Given these 2 characteristic features, how might exposure to the concept of God influence behavior? Leveraging classic and recent theorizing on self-regulation and social cognition, we predict and test for 2 divergent effects of exposure to notions of God on self-regulatory processes. Specifically, we show that participants reminded of God (vs. neutral or positive concepts) demonstrate both decreased active goal pursuit (Studies 1, 2, and 5) and increased temptation resistance (Studies 3, 4, and 5). These findings provide the first experimental evidence that exposure to God influences goal pursuit and suggest that the ever-present cultural reminders of God can be both burden and benefit for self-regulation.

Label-free optical biosensors based on aptamer-functionalized porous silicon scaffolds.

PubMed

Urmann, Katharina; Walter, Johanna-Gabriela; Scheper, Thomas; Segal, Ester

2015-02-03

A proof-of-concept for a label-free and reagentless optical biosensing platform based on nanostructured porous silicon (PSi) and aptamers is presented in this work. Aptamers are oligonucleotides (single-stranded DNA or RNA) that can bind their targets with high affinity and specificity, making them excellent recognition elements for biosensor design. Here we describe the fabrication and characterization of aptamer-conjugated PSi biosensors, where a previously characterized his-tag binding aptamer (6H7) is used as model system. Exposure of the aptamer-functionalized PSi to the target proteins as well as to complex fluids (i.e., bacteria lysates containing target proteins) results in robust and well-defined changes in the PSi optical interference spectrum, ascribed to specific aptamer-protein binding events occurring within the nanoscale pores, monitored in real time. The biosensors show exceptional stability and can be easily regenerated by a short rinsing step for multiple biosensing analyses. This proof-of-concept study demonstrates the possibility of designing highly stable and specific label-free optical PSi biosensors, employing aptamers as capture probes, holding immense potential for application in detection of a broad range of targets, in a simple yet reliable manner.

Hydrogen disposal investigation for the Space Shuttle launch complex at Vandenberg Air Force Base

NASA Technical Reports Server (NTRS)

Breit, Terry J.; Elliott, George

1987-01-01

The concern of an overpressure condition on the aft end of the Space Shuttle caused by ignition of unburned hydrogen being trapped in the Space Shuttle Main Engine exhaust duct at the Vandenberg AFB launch complex has been investigated for fifteen months. Approximately twenty-five concepts have been reviewed, with four concepts being thoroughly investigated. The four concepts investigated were hydrogen burnoff ignitors (ignitors located throughout the exhaust duct to continuously ignite any unburned hydrogen), jet mixing (utilizing large volumes of high pressure air to ensure complete combustion of the hydrogen), steam inert (utilizing flashing hot water to inert the duct with steam) and open duct concept (design an open duct or above grade J-deflector to avoid trapping hydrogen gas). Extensive studies, analyses and testing were performed at six test sites with technical support from twenty-two major organizations. In December 1986, the Air Force selected the steam inert concept to be utilized at the Vandenberg launch complex and authorized the design effort.

Mining Concept Maps to Understand University Students' Learning

ERIC Educational Resources Information Center

Yoo, Jin Soung; Cho, Moon-Heum

2012-01-01

Concept maps, visual representations of knowledge, are used in an educational context as a way to represent students' knowledge, and identify mental models of students; however there is a limitation of using concept mapping due to its difficulty to evaluate the concept maps. A concept map has a complex structure which is composed of concepts and…

Spacecraft Complexity Subfactors and Implications on Future Cost Growth

NASA Technical Reports Server (NTRS)

Leising, Charles J.; Wessen, Randii; Ellyin, Ray; Rosenberg, Leigh; Leising, Adam

2013-01-01

During the last ten years the Jet Propulsion Laboratory has used a set of cost-risk subfactors to independently estimate the magnitude of development risks that may not be covered in the high level cost models employed during early concept development. Within the last several years the Laboratory has also developed a scale of Concept Maturity Levels with associated criteria to quantitatively assess a concept's maturity. This latter effort has been helpful in determining whether a concept is mature enough for accurate costing but it does not provide any quantitative estimate of cost risk. Unfortunately today's missions are significantly more complex than when the original cost-risk subfactors were first formulated. Risks associated with complex missions are not being adequately evaluated and future cost growth is being underestimated. The risk subfactor process needed to be updated.

Integrating Multimedia Instructional Design Principles with Complex Physiological Concepts in Reproductive Science

ERIC Educational Resources Information Center

Oki, Angela Christine

2011-01-01

This dissertation examines the effect of digital multimedia presentations as a method to teach complex concepts in reproductive physiology. The digital presentations developed for this research consisted of two-dimensional (2-D) and three-dimensional (3-D) animations, scriptmessaging and narration. The topics were "Mammalian Ovarian…

The Internationalisation of Curricula: The Complexity and Diversity of Meaning in and beyond Japanese Universities

ERIC Educational Resources Information Center

Takagi, Hiroyuki

2015-01-01

The interpretation and implementation of ideas about the internationalisation of curricula (IoC) are complicated and multi-faceted. The complex and diverse perspectives on IoC reflect two concepts: "internationalisation" and "curriculum". These concepts embody contrasting perspectives on issues, including the competition-type…

Racial Microstressors, Racial Self-Concept, and Depressive Symptoms Among Male African Americans During the Transition to Adulthood

PubMed Central

Kogan, Steven M.; Yu, Tianyi; Allen, Kimberly A.; Brody, Gene H.

2015-01-01

Racial discrimination is a pervasive stressor that can undermine mental health among African American youth and young adults. Several studies identify links between racial discrimination and depressive symptoms; however, this research base does not focus on male African American youth who experience significant racism-related stress during the transition to young adulthood. Moreover, few prospective studies consider significant confounding variables that affect exposure to and perception of discriminatory treatment. In response to this need, we examined the effect of exposure to racial discrimination from ages 16–18 on depressive symptoms among male African Americans at age 20. Racial self-concept, one’s sense of positivity about one’s race, was examined as a mediator and self-control as a moderator. Hypotheses were tested with 222 participants, age 16 at baseline and age 20 at the endpoint. Participants provided self-report data at 5 time points. Exposure to racial discrimination from ages 16–18 predicted depressive symptoms at age 20, net of confounding influences. Racial self-concept mediated this effect. Self-control moderated the influence of discrimination on racial self-concept. This study underscores the salience of racial discrimination in the development of depressive symptoms among African American male youth and the clinical utility of interventions targeting racial pride and self-control. PMID:25344920

Prenatal exposure to tetrachloroethylene-contaminated drinking water and the risk of congenital anomalies: a retrospective cohort study

PubMed Central

2009-01-01

Background Prior animal and human studies of prenatal exposure to solvents including tetrachloroethylene (PCE) have shown increases in the risk of certain congenital anomalies among exposed offspring. Objectives This retrospective cohort study examined whether PCE contamination of public drinking water supplies in Massachusetts influenced the occurrence of congenital anomalies among children whose mothers were exposed around the time of conception. Methods The study included 1,658 children whose mothers were exposed to PCE-contaminated drinking water and a comparable group of 2,999 children of unexposed mothers. Mothers completed a self-administered questionnaire to gather information on all of their prior births, including the presence of anomalies, residential histories and confounding variables. PCE exposure was estimated using EPANET water distribution system modeling software that incorporated a fate and transport model. Results Children whose mothers had high exposure levels around the time of conception had an increased risk of congenital anomalies. The adjusted odds ratio of all anomalies combined among children with prenatal exposure in the uppermost quartile was 1.5 (95% CI: 0.9, 2.5). No meaningful increases in the risk were seen for lower exposure levels. Increases were also observed in the risk of neural tube defects (OR: 3.5, 95% CI: 0.8, 14.0) and oral clefts (OR 3.2, 95% CI: 0.7, 15.0) among offspring with any prenatal exposure. Conclusion The results of this study suggest that the risk of certain congenital anomalies is increased among the offspring of women who were exposed to PCE-contaminated drinking water around the time of conception. Because these results are limited by the small number of children with congenital anomalies that were based on maternal reports, a follow-up investigation should be conducted with a larger number of affected children who are identified by independent records. PMID:19778411

Evaluating Motivation for the Use of an Electronic Health Record Simulation Game.

PubMed

McLeod, Alexander; Hewitt, Barbara; Gibbs, David; Kristof, Caitlin

2017-01-01

Experiential learning via simulation offers a variety of benefits including reduced risks, repetitive exposure, and mastery of complex processes. How to motivate people to engage in and enjoy playing games is an important concept in the creation of serious games focused on learning new skills. This study sought to determine the motivators that increase users' pleasurable experience when playing an electronic health record simulation game. To examine how intrinsic and extrinsic motivation affected both engagement and enjoyment, we surveyed students of health professions at one university. Results indicate that while both forms of motivation are significant in increasing engagement and enjoyment, extrinsic motivation such as badges, points, and scoreboards were much more important than internal motivations for our participants. These findings have implications for the development of an electronic health record simulation game.

Evaluating Motivation for the Use of an Electronic Health Record Simulation Game

PubMed Central

McLeod, Alexander; Hewitt, Barbara; Gibbs, David; Kristof, Caitlin

2017-01-01

Experiential learning via simulation offers a variety of benefits including reduced risks, repetitive exposure, and mastery of complex processes. How to motivate people to engage in and enjoy playing games is an important concept in the creation of serious games focused on learning new skills. This study sought to determine the motivators that increase users’ pleasurable experience when playing an electronic health record simulation game. To examine how intrinsic and extrinsic motivation affected both engagement and enjoyment, we surveyed students of health professions at one university. Results indicate that while both forms of motivation are significant in increasing engagement and enjoyment, extrinsic motivation such as badges, points, and scoreboards were much more important than internal motivations for our participants. These findings have implications for the development of an electronic health record simulation game. PMID:28566987

Power Balance Analysis of the Prototype-Material Plasma Exposure eXperiment

NASA Astrophysics Data System (ADS)

Showers, M. A.; Biewer, T. M.; Caneses, J. F.; Caughman, J. B. O.; Lumsdaine, A.; Owen, L.; Rapp, J.; Youchison, D.; Beers, C. J.; Donovan, D. C.; Kafle, N.; Ray, H. B.

2017-10-01

The Prototype-Material Plasma Exposure eXperiment (Proto-MPEX) is a test bed for the plasma source concept for the planned Material Plasma Exposure eXperiment (MPEX), a steady-state linear device studying plasma material interactions for fusion reactors. A power balance of Proto-MPEX attempts to identify machine operating parameters that will improve Proto-MPEX's performance, potentially impacting the MPEX design concept. A power balance has been performed utilizing an extensive diagnostic suite to identify mechanisms and locations of power loss from the main plasma. The diagnostic package includes infrared cameras, double Langmuir probes, fluoroptic probes, Mach probes, a Thomson scattering diagnostic, a McPherson spectrometer and in-vessel thermocouples. Radiation losses are estimated with absolute calibrated spectroscopic signals. This work was supported by the U.S. D.O.E. contract DE-AC05-00OR22725.

PRELIMINARY INVESTIGATION OF THE PARALLELOGRAM CONCEPT IN GENETIC MONITORING AND RISK ESTIMATION

EPA Science Inventory

The main objective of genetic monitoring in human health surveillance is to prevent excessive exposure to genotoxic agents and to ensure the safety of the exposed or potentially-exposed populace. To attain fully this objective one must understand low dose exposure and associated ...

Obesity and perinatal TCDD exposure increases mammary tumor incidence in FVB mice

EPA Science Inventory

Breast cancer risk consistently correlates with total lifetime exposure to estrogens. Because both TCDD and adipocytes impact the estrogen pathway, we examined how TCDD and obesity interact to alter mammary cancer susceptibility. At 12.5 days post conception, we exposed FVB fema...

Food environments and dietary intakes among adults: does the type of spatial exposure measurement matter? A systematic review.

PubMed

Bivoltsis, Alexia; Cervigni, Eleanor; Trapp, Gina; Knuiman, Matthew; Hooper, Paula; Ambrosini, Gina Leslie

2018-06-09

The relationships between food environments and dietary intake have been assessed via a range of methodologically diverse measures of spatial exposure to food outlets, resulting in a largely inconclusive body of evidence, limiting informed policy intervention. This systematic review aims to evaluate the influence of methodological choice on study outcomes by examining the within-study effect of availability (e.g., counts) versus accessibility (e.g., proximity) spatial exposure measures on associations with diet. (PROSPERO registration: CRD42018085250). PubMed, Web of Science, Scopus and ScienceDirect databases were searched for empirical studies from 1980 to 2017, in the English language, involving adults and reporting on the statistical association between a dietary outcome and spatial exposure measures of both availability and accessibility. Studies were appraised using an eight-point quality criteria with a narrative synthesis of results. A total of 205 associations and 44 relationships (i.e., multiple measures of spatial exposure relating to a particular food outlet type and dietary outcome) were extracted from 14 eligible articles. Comparative measures were dominated by counts (availability) and proximity (accessibility). Few studies compared more complex measures and all counts were derived from place-based measures of exposure. Sixteen of the 44 relationships had a significant effect involving an availability measure whilst only 8 had a significant effect from an accessibility measure. The largest effect sizes in relationships were mostly for availability measures. After stratification by scale, availability measure had the greatest effect size in 139 of the 176 pairwise comparisons. Of the 33% (68/205) of associations that reached significance, 53/68 (78%) were from availability measures. There was no relationship between study quality and reported study outcomes. The limited evidence suggests that availability measures may produce significant and greater effect sizes than accessibility measures. However, both availability and accessibility measures may be important concepts of spatial exposure depending on the food outlet type and dietary outcome examined. More studies reporting on multi-method effects are required to differentiate findings by the type of spatial exposure assessment and build an evidence base regarding the appropriateness and robustness of measures under different circumstances.

Design of Two RadWorks Storm Shelters for Solar Particle Event Shielding

NASA Technical Reports Server (NTRS)

Simon, Matthew; Cerro, Jeffery; Latorella, Kara; Clowdsley, Martha; Watson, Judith; Albertson, Cindy; Norman, Ryan; Le Boffe, Vincent; Walker, Steven

2014-01-01

In order to enable long-duration human exploration beyond low-Earth orbit, the risks associated with exposure of astronaut crews to space radiation must be mitigated with practical and affordable solutions. The space radiation environment beyond the magnetosphere is primarily a combination of two types of radiation: galactic cosmic rays (GCR) and solar particle events (SPE). While mitigating GCR exposure remains an open issue, reducing astronaut exposure to SPEs is achievable through material shielding because they are made up primarily of medium-energy protons. In order to ensure astronaut safety for long durations beyond low-Earth orbit, SPE radiation exposure must be mitigated. However, the increasingly demanding spacecraft propulsive performance for these ambitious missions requires minimal mass and volume radiation shielding solutions which leverage available multi-functional habitat structures and logistics as much as possible. This paper describes the efforts of NASA's RadWorks Advanced Exploration Systems (AES) Project to design two minimal mass SPE radiation shelter concepts leveraging available resources: one based upon reconfiguring habitat interiors to create a centralized protection area and one based upon augmenting individual crew quarters with waterwalls and logistics. Discussion items include the design features of the concepts, a radiation analysis of their implementations, an assessment of the parasitic mass of each concept, and the result of a human in the loop evaluation performed to drive out design and operational issues.

Exposure assessment for endocrine disruptors: some considerations in the design of studies.

PubMed Central

Rice, Carol; Birnbaum, Linda S; Cogliano, James; Mahaffey, Kathryn; Needham, Larry; Rogan, Walter J; vom Saal, Frederick S

2003-01-01

In studies designed to evaluate exposure-response relationships in children's development from conception through puberty, multiple factors that affect the generation of meaningful exposure metrics must be considered. These factors include multiple routes of exposure; the timing, frequency, and duration of exposure; need for qualitative and quantitative data; sample collection and storage protocols; and the selection and documentation of analytic methods. The methods for exposure data collection and analysis must be sufficiently robust to accommodate the a priori hypotheses to be tested, as well as hypotheses generated from the data. A number of issues that must be considered in study design are summarized here. PMID:14527851

Method for evaluating human exposure to 60 HZ electric fields

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

Deno, D.W.; Silva, M.

1984-07-01

This paper describes a method that has been successfully used to evaluate human exposure to 60 Hz electric fields. An exposure measuring system that uses an electric field sensor vest and data collection instrumentation is presented. Exposure concepts and activity factors are discussed and experimental data collected with the exposure system are provided. This method can be used to measure exposure to a wide range of electric field with intensities from less than 1 V/m to more than 10 kV/m. Results may be translated to characterize various exposure criteria (time histogram of unperturbed field, surface fields, internal current density, totalmore » body current, etc).« less

Students' Affordance of Teleologic Explanations and Anthropomorphic Language in Eliciting Concepts in Physics

ERIC Educational Resources Information Center

Bautista, Romiro G.

2015-01-01

This study ascertains that the students' affordance of teleologic explanations and anthropomorphic language in eliciting concepts in Physics is influenced by their age and learning exposure and experience. Using Explicative-Reductive Method of Descriptive Research, this study focused on the determinants of students' affordance of…

Threshold Concepts and Pedagogic Representation

ERIC Educational Resources Information Center

Meyer, Jan H. F.

2016-01-01

Purpose: The purpose of this paper is to present a brief exposure to the development of the threshold concepts framework (TCF), the intention being to illuminate for interested readers a broader landscape of research activity than that perhaps conveyed by the individual contributions to this special edition. Design/Methodology/Approach: There is…

Public magnetic field exposure based on internal current density for electric low voltage systems.

PubMed

Keikko, Tommi; Seesvuori, Reino; Hyvönen, Martti; Valkealahti, Seppo

2009-04-01

A measurement concept utilizing a new magnetic field exposure metering system has been developed for indoor substations where voltage is transformed from a medium voltage of 10 or 20 kV to a low voltage of 400 V. The new metering system follows the guidelines published by the International Commission on Non-Ionizing Radiation Protection. It can be used to measure magnetic field values, total harmonic distortion of the magnetic field, magnetic field exposure ratios for public and workers, load current values, and total harmonic distortion of the load current. This paper demonstrates how exposure to non-sinusoidal magnetic fields and magnetic flux density exposure values can be compared directly with limit values for internal current densities in a human body. Further, we present how the magnetic field and magnetic field exposure behaves in the vicinity of magnetic field sources within the indoor substation and in the neighborhood. Measured magnetic fields around the substation components have been used to develop a measurement concept by which long-term measurements in the substations were performed. Long-term measurements revealed interesting and partly unexpected dependencies between the measured quantities, which have been further analyzed. The principle of this paper is to substitute a demanding exposure measurement with measurements of the basic quantities like the 50 Hz fundamental magnetic field component, which can be estimated based on the load currents for certain classes of substation lay-out.

Assessing chemical exposure and ecological impacts of environmental surface waters using cell culture-based metabolomic

EPA Science Inventory

Waste water treatment plants (WWTPs), as well as industrial and agricultural operations release complex mixtures of anthropogenic chemicals that negatively affect surface water quality. Previous studies have shown that exposure to such complex chemical mixtures can produce adver...

Assessment of exposure to the Penicillium glabrum complex in cork industry using complementing methods.

PubMed

Viegas, Carla; Sabino, Raquel; Botelho, Daniel; dos Santos, Mateus; Gomes, Anita Quintal

2015-09-01

Cork oak is the second most dominant forest species in Portugal and makes this country the world leader in cork export. Occupational exposure to Chrysonilia sitophila and the Penicillium glabrum complex in cork industry is common, and the latter fungus is associated with suberosis. However, as conventional methods seem to underestimate its presence in occupational environments, the aim of our study was to see whether information obtained by polymerase chain reaction (PCR), a molecular-based method, can complement conventional findings and give a better insight into occupational exposure of cork industry workers. We assessed fungal contamination with the P. glabrum complex in three cork manufacturing plants in the outskirts of Lisbon using both conventional and molecular methods. Conventional culturing failed to detect the fungus at six sampling sites in which PCR did detect it. This confirms our assumption that the use of complementing methods can provide information for a more accurate assessment of occupational exposure to the P. glabrum complex in cork industry.

Shedding Light on the Etiology of Sports Injuries: A Look Behind the Scenes of Time-to-Event Analyses.

PubMed

Nielsen, Rasmus Østergaard; Malisoux, Laurent; Møller, Merete; Theisen, Daniel; Parner, Erik Thorlund

2016-04-01

The etiological mechanism underpinning any sports-related injury is complex and multifactorial. Frequently, athletes perceive "excessive training" as the principal factor in their injury, an observation that is biologically plausible yet somewhat ambiguous. If the applied training load is suddenly increased, this may increase the risk for sports injury development, irrespective of the absolute amount of training. Indeed, little to no rigorous scientific evidence exists to support the hypothesis that fluctuations in training load, compared to absolute training load, are more important in explaining sports injury development. One reason for this could be that prospective data from scientific studies should be analyzed in a different manner. Time-to-event analysis is a useful statistical tool in which to analyze the influence of changing exposures on injury risk. However, the potential of time-to-event analysis remains insufficiently exploited in sports injury research. Therefore, the purpose of the present article was to present and discuss measures of association used in time-to-event analyses and to present the advanced concept of time-varying exposures and outcomes. In the paper, different measures of association, such as cumulative relative risk, cumulative risk difference, and the classical hazard rate ratio, are presented in a nontechnical manner, and suggestions for interpretation of study results are provided. To summarize, time-to-event analysis complements the statistical arsenal of sports injury prevention researchers, because it enables them to analyze the complex and highly dynamic reality of injury etiology, injury recurrence, and time to recovery across a range of sporting contexts.

Emotional tagging--a simple hypothesis in a complex reality.

PubMed

Bergado, Jorge A; Lucas, Morgan; Richter-Levin, Gal

2011-06-01

At the psychological level, the notion that emotional events may be better remembered is a long accepted view. Its translation into neurobiological mechanisms has led to the proposal of the 'emotional tag' concept, according to which, the activation of the amygdala by emotionality would result in modulation of neural plasticity in brain regions (e.g. hippocampus) involved in forming memory of the emotional event. In line with this idea, amygdala activation (by electrical stimulation or exposure to an emotional event) has been demonstrated to affect synaptic plasticity in the hippocampus. Furthermore, the mechanisms associated with the formation of a 'synaptic tag', which is a mechanism proposed to explain the specificity of synaptic plasticity, could subserve the effects of the 'emotional tag' on synaptic plasticity in the hippocampus. The literature reviewed here supports this view but points also to additional factors that should be taken into consideration, such as intensity, duration, controllability of the emotional experience, age of exposure and relations between the emotional aspects of the experience and the event-to-be-remembered. These factors do not only affect the behavioral outcome of the stressful experience but also find their expression in variations in the neuronal and biochemical pathways that are activated, and in the way those will interact with memory formation mechanisms. While adding complexity to the notion of the 'emotional tag', taking such factors into consideration is likely to bring us closer to elucidating the neural mechanisms involved in emotional memory modulation and to our understanding of the neurobiology of associated disorders, such as PTSD. Copyright © 2011 Elsevier Ltd. All rights reserved.

Workflow and Proof of Concept for Non-Targeted Analysis of Environmental Samples by LC-MS/MS

EPA Science Inventory

The human exposure includes thousands of chemicals acquired through various routes of exposure such as inhalation, ingestion, dermal contact, and indirect ingestion. Rapid assessment and screening of these chemicals is a difficult challenge facing EPA in its mission to protect pu...

Chemical Mixtures Health Risk Assessment: Overview of Exposure Assessment, Whole Mixtures Assessments; Basic Concepts

EPA Science Inventory

This problems-based, half-day, introductory workshop focuses on methods to assess health risks posed by exposures to chemical mixtures in the environment. Chemical mixtures health risk assessment methods continue to be developed and evolve to address concerns over health risks f...

WORKSHOP TO IDENTIFY CRITICAL WINDOWS OF EXPOSURE FOR CHILDREN'S HEALTH: REPRODUCTIVE HEALTH IN CHILDREN AND ADOLESCENTS WORK GROUP SUMMARY

EPA Science Inventory

This workgroup report addresses the central question: what are the critical windows during development (pre-conception through puberty) when exposure to xenobiotics may have the greatest adverse impact on subsequent reproductive health. The reproductive system develops in stages...

Role of complex organic arsenicals in food in aggregate exposure to arsenic.

PubMed

Thomas, David J; Bradham, Karen

2016-11-01

For much of the world's population, food is the major source of exposure to arsenic. Exposure to this non-essential metalloid at relatively low levels may be linked to a wide range of adverse health effects. Thus, evaluating foods as sources of exposure to arsenic is important in assessing risk and developing strategies that protect public health. Although most emphasis has been placed on inorganic arsenic as human carcinogen and toxicant, an array of arsenic-containing species are found in plants and animals used as foods. Here, we 2evaluate the contribution of complex organic arsenicals (arsenosugars, arsenolipids, and trimethylarsonium compounds) that are found in foods and consider their origins, metabolism, and potential toxicity. Commonalities in the metabolism of arsenosugars and arsenolipids lead to the production of di-methylated arsenicals which are known to exert many toxic effects. Evaluating foods as sources of exposure to these complex organic arsenicals and understanding the formation of reactive metabolites may be critical in assessing their contribution to aggregate exposure to arsenic. Copyright © 2016. Published by Elsevier B.V.

Concept locator: a client-server application for retrieval of UMLS metathesaurus concepts through complex boolean query.

PubMed

Nadkarni, P M

1997-08-01

Concept Locator (CL) is a client-server application that accesses a Sybase relational database server containing a subset of the UMLS Metathesaurus for the purpose of retrieval of concepts corresponding to one or more query expressions supplied to it. CL's query grammar permits complex Boolean expressions, wildcard patterns, and parenthesized (nested) subexpressions. CL translates the query expressions supplied to it into one or more SQL statements that actually perform the retrieval. The generated SQL is optimized by the client to take advantage of the strengths of the server's query optimizer, and sidesteps its weaknesses, so that execution is reasonably efficient.

Secondary Teachers' Conception of Various Forms of Complex Numbers

ERIC Educational Resources Information Center

Karakok, Gulden; Soto-Johnson, Hortensia; Dyben, Stephenie Anderson

2015-01-01

This study explores in-service high school mathematics teachers' conception of various forms of complex numbers and ways in which they transition between different representations of these forms. One 90-min interview was conducted with three high school mathematics teachers after they completed three professional development sessions, each 4 h, on…

[Locomotive syndrome and frailty. Musculoskeletal ambulation disorder symptom complex and locomotive syndrome].

PubMed

Yamamoto, Noriaki

2012-04-01

Musculoskeletal ambulation disorder symptom complex is the new concept of musculoskeletal disorders with disability in walking and balance, which lead to the high risk of fall and lower activity in elderly. Locomotive syndrome is another concept to aware of healthy locomotive organ for early prevention of orthopedic disease.

Complex trauma and mental health in children and adolescents placed in foster care: findings from the National Child Traumatic Stress Network.

PubMed

Greeson, Johanna K P; Briggs, Ernestine C; Kisiel, Cassandra L; Layne, Christopher M; Ake, George S; Ko, Susan J; Gerrity, Ellen T; Steinberg, Alan M; Howard, Michael L; Pynoos, Robert S; Fairbank, John A

2011-01-01

Many children in the child welfare system (CWS) have histories of recurrent interpersonal trauma perpetrated by caregivers early in life often referred to as complex trauma. Children in the CWS also experience a diverse range of reactions across multiple areas of functioning that are associated with such exposure. Nevertheless, few CWSs routinely screen for trauma exposure and associated symptoms beyond an initial assessment of the precipitating event. This study examines trauma histories, including complex trauma exposure (physical abuse, sexual abuse, emotional abuse, neglect, domestic violence), posttraumatic stress, and behavioral and emotional problems of 2,251 youth (age 0 to 21; M = 9.5, SD = 4.3) in foster care who were referred to a National Child Traumatic Stress Network site for treatment. High prevalence rates of complex trauma exposure were observed: 70.4% of the sample reported at least two of the traumas that constitute complex trauma; 11.7% of the sample reported all 5 types. Compared to youth with other types of trauma, those with complex trauma histories had significantly higher rates of internalizing problems, posttraumatic stress, and clinical diagnoses, and differed on some demographic variables. Implications for child welfare practice and future research are discussed.

Ontology patterns for complex topographic feature yypes

USGS Publications Warehouse

Varanka, Dalia E.

2011-01-01

Complex feature types are defined as integrated relations between basic features for a shared meaning or concept. The shared semantic concept is difficult to define in commonly used geographic information systems (GIS) and remote sensing technologies. The role of spatial relations between complex feature parts was recognized in early GIS literature, but had limited representation in the feature or coverage data models of GIS. Spatial relations are more explicitly specified in semantic technology. In this paper, semantics for topographic feature ontology design patterns (ODP) are developed as data models for the representation of complex features. In the context of topographic processes, component assemblages are supported by resource systems and are found on local landscapes. The topographic ontology is organized across six thematic modules that can account for basic feature types, resource systems, and landscape types. Types of complex feature attributes include location, generative processes and physical description. Node/edge networks model standard spatial relations and relations specific to topographic science to represent complex features. To demonstrate these concepts, data from The National Map of the U. S. Geological Survey was converted and assembled into ODP.

Focus on the legislative approach to short half life radioactive hospital waste releasing.

PubMed

Petrucci, Caterina; Traino, Antonio Claudio

2015-11-01

We propose to summarize the advancements introduced by the new Directive 2013/59/Euratom concerning the concept of clearance, for which the radioactive medical waste represents a typical candidate. We also intend to spotlight disputable points in the regulatory scheme in force in Italy, as well to make a contribution to evaluate whether the practice of patients' urine storing, stated by it, can be regarded to be proper. With directing our interest to radionuclides used in Nuclear Medicine, we first present an overview of how the clearance concept, and that of exemption closely related to it, have been developed from the previous Directive 96/29 to the new one; then we describe the implementation of these concepts in the Italian legislation. Subsequently we estimate the exposure due both to keeping the effluent on site and to direct discharging it to the environment. In line with a well established international consensus, the Directive 2013/59 drives simple and harmonized regulation of clearance. On the contrary, some complexity and lack of consistency can be found in the framework of the national legislation affecting the radioactive medical waste handling. In addition the practice of excreta storing is disputed not to be really beneficial. The opportunity should be taken to make the whole system of these requirements simpler and more consistent and effective when it is revised to transpose the new Directive. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Animating the Discussion about Climate Change

NASA Astrophysics Data System (ADS)

Ratner, A.

2016-12-01

Abstract concepts such as climate change are extremely difficult for both students and adults to grasp. Given that many of these concepts involve issues at global scales or at a microscopic level, photos and video are simply insufficient much of the time. Through an innovative partnership between The Marine Mammal Center, a marine mammal hospital and education facility, and the California College of the Arts Animation Department, we have been able to provide animation students real-world experience in producing scientific animations, and the Center has been able to create an animated video highlighting the science of climate change and effects on marine mammals. Using the science direct from our veterinary and research teams, along with scientifically tested communication strategies related to climate change from the National Network of Ocean and Climate Change Interpretation and Frameworks Institute, this video enables us to teach students and adults of all ages these complex scientific concepts in a fun, engaging, and easily understandable way. Utilizing the skill set and expertise of the College professor as director (currently a lead animator at Pixar Animation), this video provided animation students critical experience in the animation field, exposure and engagement in a critical environmental issue, and an understanding of the opportunities available within the field of animation for educational and scientific purposes. This presentation will highlight the opportunities to utilize animation for educational purposes and provide resources surrounding climate change that could be beneficial to educators at their own organizations.

Concept Mapping to Assess Learning and Understanding of Complexity in Courses on Global Climate Change

NASA Astrophysics Data System (ADS)

Rebich-Hespanha, S.; Gautier, C.

2010-12-01

The complex nature of climate change science poses special challenges for educators wishing to broaden and deepen student understanding of the climate system and its sensitivity to and impacts upon human activity. Learners have prior knowledge that may limit their perception and processing of the multiple relationships between processes (e.g., feedbacks) that arise in global change science, and these existing mental models serve as the scaffold for all future learning. Because adoption of complex scientific concepts is not likely if instruction includes presentation of information or concepts that are not compatible with the learners’ prior knowledge, providing effective instruction on this complex topic requires learning opportunities that are anchored upon an evaluation of the limitations and inaccuracies of the learners’ existing understandings of the climate system. The formative evaluation that serves as the basis for planning such instruction can also be useful as a baseline against which to evaluate subsequent learning. We will present concept-mapping activities that we have used to assess students’ knowledge and understanding about global climate change in courses that utilized multiple assessment methods including presentations, writings, discussions, and concept maps. The courses in which these activities were completed use a variety of instructional approaches (including standard lectures and lab assignments and a mock summit) to help students understand the inherently interdisciplinary topic of global climate change, its interwoven human and natural causes, and the connections it has with society through a complex range of political, social, technological and economic factors. Two instances of concept map assessment will be presented: one focused on evaluating student understanding of the major components of the climate system and their interconnections, and the other focused on student understanding of the connections between climate change and the global food system. We will discuss how concept mapping can be used to demonstrate evidence of learning and conceptual change, and also how it can be used to provide information about gaps in knowledge and misconceptions students have about the topic.

Jupyter Notebooks as tools for interactive learning of Concepts in Structural Geology and efficient grading of exercises.

NASA Astrophysics Data System (ADS)

Niederau, Jan; Wellmann, Florian; Maersch, Jannik; Urai, Janos

2017-04-01

Programming is increasingly recognised an important skill for geoscientists - however, the hurdle to jump into programming for students with little or no experience can be high. We present here teaching concepts on the basis of Jupyter notebooks that combine, in an intuitive way, formatted instruction text with code cells in a single environment. This integration allows for an exposure to programming on several levels: from a complete interactive presentation of content, where students require no or very limited programming experience, to highly complex geoscientific computations. We consider these notebooks therefore as an ideal medium to present computational content to students in the field of geosciences. We show here how we use these notebooks to develop digital documents in Python for undergrad-students, who can then learn about basic concepts in structural geology via self-assessment. Such notebooks comprise concepts such as: stress tensor, strain ellipse, or the mohr circle. Students can interactively change parameters, e.g. by using sliders and immediately see the results. They can further experiment and extend the notebook by writing their own code within the notebook. Jupyter Notebooks for teaching purposes can be provided ready-to-use via online services. That is, students do not need to install additional software on their devices in order to work with the notebooks. We also use Jupyter Notebooks for automatic grading of programming assignments in multiple lectures. An implemented workflow facilitates the generation, distribution of assignments, as well as the final grading. Compared to previous grading methods with a high percentage of repetitive manual grading, the implemented workflow proves to be much more time efficient.

The margin of internal exposure (MOIE) concept for dermal risk assessment based on oral toxicity data - A case study with caffeine.

PubMed

Bessems, Jos G M; Paini, Alicia; Gajewska, Monika; Worth, Andrew

2017-12-01

Route-to-route extrapolation is a common part of human risk assessment. Data from oral animal toxicity studies are commonly used to assess the safety of various but specific human dermal exposure scenarios. Using theoretical examples of various user scenarios, it was concluded that delineation of a generally applicable human dermal limit value is not a practicable approach, due to the wide variety of possible human exposure scenarios, including its consequences for internal exposure. This paper uses physiologically based kinetic (PBK) modelling approaches to predict animal as well as human internal exposure dose metrics and for the first time, introduces the concept of Margin of Internal Exposure (MOIE) based on these internal dose metrics. Caffeine was chosen to illustrate this approach. It is a substance that is often found in cosmetics and for which oral repeated dose toxicity data were available. A rat PBK model was constructed in order to convert the oral NOAEL to rat internal exposure dose metrics, i.e. the area under the curve (AUC) and the maximum concentration (C max ), both in plasma. A human oral PBK model was constructed and calibrated using human volunteer data and adapted to accommodate dermal absorption following human dermal exposure. Use of the MOIE approach based on internal dose metrics predictions provides excellent opportunities to investigate the consequences of variations in human dermal exposure scenarios. It can accommodate within-day variation in plasma concentrations and is scientifically more robust than assuming just an exposure in mg/kg bw/day. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Effect of NET-1 siRNA conjugated sub-micron bubble complex combined with low-frequency ultrasound exposure in gene transfection

PubMed Central

Wu, Bolin; Liang, Xitian; Jing, Hui; Han, Xue; Sun, Yixin; Guo, Cunli; Liu, Ying; Cheng, Wen

2018-01-01

The present study evaluated the effect of NET-1 siRNA-conjugated sub-micron bubble (SMB) complexes combined with low-frequency ultrasound exposure in gene transfection. The NET-1 gene was highly expressed level in SMMC-7721 human hepatocellular carcinoma cell line. The cells were divided into seven groups and treated with different conditions. The groups with or without low-frequency ultrasound exposure, groups of adherent cells, and suspension cells were separated. The NET-1 siRNA-conjugated SMB complexes were made in the laboratory and tested by Zetasizer Nano ZS90 analyzer. Flow cytometry was used to estimate the transfection efficiency and cellular apoptosis. Western blot and quantitative real-time polymerase chain reaction (qPCR) were used for the estimation of the protein and mRNA expressions, respectively. Transwell analysis determined the migration and invasion capacities of the tumor cells. The results did not show any difference in the transfection efficiency between adherent and suspension cells. However, the NET-1 siRNA-SMB complexes combined with low-frequency ultrasound exposure could enhance the gene transfection effectively. In summary, the NET-1 siRNA-SMB complexes appeared to be promising gene vehicle. PMID:29423111

The concept of the set to objectification of LLLT exposure

NASA Astrophysics Data System (ADS)

Gryko, Lukasz; Gilewski, Marian; Szymanska, Justyna; Zajac, Andrzej; Rosc, Danuta

2013-01-01

In this article authors present the developed optoelectronic set for controlled, repeatable exposure by electromagnetic radiation of biological structures in the spectral band of tissue transmission window 600-1000 nm. The set allows for an objective selection and control of exposure parameters and comparison of results for variable energetic, spectral and polarization parameters of radiation beam. Possibility of objective diagnostics of tissue state during laser treatment was provided in the presented optoelectronic set.

THE POWER TO DETECT A DIFFERENCE: DETERMINING SAMPLE SIZE REQUIREMENTS FOR EVALUATION OF REPRODUCTIVE/DEVELOPMENTAL EFFECTS FROM EXPOSURE TO COMPLEX MIXTURES OF DISINFECTION BYPRODUCTS

EPA Science Inventory

Toxicological assessment of environmentally-realistic complex mixtures of drinking-water disinfection byproducts (DBPs) are needed to address concerns raised by some epidemiological studies showing associations between exposure to chemically disinfected water and adverse reproduc...

Using Concept Maps to Assess Interdisciplinary Integration of Green Engineering Knowledge

ERIC Educational Resources Information Center

Borrego, Maura; Newswander, Chad B.; McNair, Lisa D.; McGinnis, Sean; Paretti, Marie C.

2009-01-01

Engineering education, like many fields, has started to explore the benefits of concept maps as an assessment technique for knowledge integration. Because they allow students to graphically link topics and represent complex interconnections among diverse concepts, we argue that concept maps are particularly appropriate for assessing…

Concept Mapping for Critical Thinking: Efficacy, Timing, & Type

ERIC Educational Resources Information Center

Harris, Charles M.; Zha, Shenghua

2017-01-01

Many college students are not progressing in the development of their critical thinking skills. Concept mapping is a technique for facilitating validation of one's critical thinking by graphically depicting the structure of complex concepts. Each of our three studies of concept mapping involved approximately 240 students enrolled in four sections…

Computer Literacy Project. A General Orientation in Basic Computer Concepts and Applications.

ERIC Educational Resources Information Center

Murray, David R.

This paper proposes a two-part, basic computer literacy program for university faculty, staff, and students with no prior exposure to computers. The program described would introduce basic computer concepts and computing center service programs and resources; provide fundamental preparation for other computer courses; and orient faculty towards…

Structured Interviews on Children's Conceptions of Computers. Technical Report No. 19.

ERIC Educational Resources Information Center

Mawby, Ronald; And Others

The terms and concepts children used to explain their beliefs about computers before and after classroom exposure to microcomputers were studied to identify misconceptions about computers that could interfere with computer-based learning. Children in each of two classrooms at the Bank Street School for Children were interviewed individually on…

Resilience: Revisiting the Concept and Its Utility for Social Research

ERIC Educational Resources Information Center

Kolar, Katarina

2011-01-01

Researchers of resilience seek to understand why some people will recover from or avoid negative outcomes against the odds associated with exposure to particular adversities. Over the last two decades the concept of resilience has experienced "burgeoning interest" (Ungar, 2005, p. xvii). However, due to a lack of consistency in defining and…

Beyond Pleasure: Exploring the Eudaimonic Entertainment Experience

ERIC Educational Resources Information Center

Wirth, Werner; Hofer, Matthias; Schramm, Holger

2012-01-01

We examine the notion of eudaimonic entertainment during exposure to a sad but meaningful movie, using a new measure consisting of 5 dimensions derived from research on positive psychology. We, thereby, transfer the conception of eudaimonic well-being to the conception of entertainment. Results of a confirmatory factor analysis show that the 5…

Computer-assisted concept mapping: Visual aids for knowledge construction

PubMed Central

Mammen, Jennifer R.

2016-01-01

Background Concept mapping is a visual representation of ideas that facilitates critical thinking and is applicable to many areas of nursing education. Computer-Assisted Concept Maps are more flexible and less constrained than traditional paper methods, allowing for analysis and synthesis of complex topics and larger amounts of data. Ability to iteratively revise and collaboratively create computerized maps can contribute to enhanced interpersonal learning. However, there is limited awareness of free software that can support these types of applications. Discussion This educational brief examines affordances and limitations of Computer-Assisted Concept Maps and reviews free software for development of complex, collaborative malleable maps. Free software such as VUE, Xmind, MindMaple, and others can substantially contribute to utility of concept-mapping for nursing education. Conclusions Computerized concept-mapping is an important tool for nursing and is likely to hold greater benefit for students and faculty than traditional pen and paper methods alone. PMID:27351610

The development of structural complexity in the child's concept of family: the effect of cognitive stage, sex, and intactness of family.

PubMed

Wedemeyer, N V; Bickhard, M H; Cooper, R G

1989-12-01

Twenty-eight boys and 28 girls at each of the Piagetian preoperational, concrete operational, and formal operational cognitive stages were given an interview focusing on their concepts of family. Half of each group were from intact families, and half were from divorced families. Interviews were scored for two structural aspects of the concept of family: conceptual level, and use of dimensions that structure the concept. The complexity of children's concepts was strongly related to cognitive stage and, to a lesser degree, to sex. Frequency of use of concept dimensions was strongly affected by general developmental level, though not specifically cognitive stage, and by intactness of family, but to a lesser degree by sex. Specific information is provided on the effect of these factors on perceptions of family composition, parental roles, and breadth of family activities.

Using Concepts from Complexity Science to Accelerate Curricular Revision

ERIC Educational Resources Information Center

Goldman, Ellen F.; Mintz, Matthew L.

2017-01-01

Curricular revision can be an arduous and challenging process. The literature favors a rational planned process for doing so, but offers little advice regarding how to proceed when the time required for such an approach is not available. This article describes our use of four concepts from complexity science to revise a medical school curriculum…

Semantic Features, Perceptual Expectations, and Frequency as Factors in the Learning of Polar Spatial Adjective Concepts.

ERIC Educational Resources Information Center

Dunckley, Candida J. Lutes; Radtke, Robert C.

Two semantic theories of word learning, a perceptual complexity hypothesis (H. Clark, 1970) and a quantitative complexity hypothesis (E. Clark, 1972) were tested by teaching 24 preschoolers and 16 college students CVC labels for five polar spatial adjective concepts having single word representations in English, and for three having no direct…

The Complex Case of Fear and Safe Space

ERIC Educational Resources Information Center

Stengel, Barbara S.

2010-01-01

Here I shine light on the concept of and call for safe space and on the implicit argument that seems to undergird both the concept and the call, complicating and problematizing the taken for granted view of this issue with the goal of revealing a more complex dynamic worthy of interpretive attention when determining educational response. I…

Board Games and Board Game Design as Learning Tools for Complex Scientific Concepts: Some Experiences

ERIC Educational Resources Information Center

Chiarello, Fabio; Castellano, Maria Gabriella

2016-01-01

In this paper the authors report different experiences in the use of board games as learning tools for complex and abstract scientific concepts such as Quantum Mechanics, Relativity or nano-biotechnologies. In particular we describe "Quantum Race," designed for the introduction of Quantum Mechanical principles, "Lab on a chip,"…

Experiences Using Pre-Exposure Prophylaxis for Safer Conception Among HIV Serodiscordant Heterosexual Couples in the United States.

PubMed

Bazzi, Angela R; Leech, Ashley A; Biancarelli, Dea L; Sullivan, Meg; Drainoni, Mari-Lynn

2017-08-01

Antiretroviral pre-exposure prophylaxis (PrEP) is a promising HIV prevention strategy for HIV serodiscordant couples (HIV-infected male, uninfected female) seeking safer conception. However, most research on PrEP for safer conception has focused on couples in sub-Saharan Africa; little is known about the perspectives or experiences of heterosexual couples in the United States. We conducted qualitative interviews with six couples (six women and five of their male partners) receiving PrEP for conception services at an urban safety net hospital in the US Northeast. In-depth interview guides explored couple relationships and contextual factors and attitudes, perceptions, and decision-making processes surrounding PrEP for safer conception. Thematic analyses focused on identifying the following emergent themes. We found that couple relationships were situated within broader social and cultural contexts of immigration, family, and community that shaped their experiences with HIV and serodiscordant relationship status. Despite strong partner support within relationships, HIV stigma and disapproval of serodiscordant relationships contributed to couples' feelings of social isolation and subsequent aspirations to have "normal" families. By enabling "natural" conception through condomless sex, PrEP for safer conception provided a sense of enhanced relationship intimacy. Couples called for increasing public awareness of PrEP through positive messaging as a way to combat HIV stigma. Findings suggest that relationship dynamics and broader social contexts appear to shape HIV serodiscordant couples' fertility desires and motivations to use PrEP. However, increased public awareness of PrEP for safer conception may be needed to combat HIV stigma at the community level.

Skull base tumors: a comprehensive review of transfacial swing osteotomy approaches.

PubMed

Moreira-Gonzalez, Andrea; Pieper, Daniel R; Cambra, Jorge Balaguer; Simman, Richard; Jackson, Ian T

2005-03-01

Numerous techniques have been proposed for the resection of skull base tumors, each one unique with regard to the region exposed and degree of technical complexity. This study describes the use of transfacial swing osteotomies in accessing lesions located at various levels of the cranial base. Eight patients who underwent transfacial swings for exposure and resection of cranial base lesions between 1996 and 2002 were studied. The mandible was the choice when wide exposure of nasopharyngeal and midline skull base tumors was necessary, especially when they involved the infratemporal fossa. The midfacial swing osteotomy was an option when access to the entire clivus was necessary. An orbital swing approach was used to access large orbital tumors lying inferior to the optic nerve and posterior to the globe, a region that is often difficult to visualize. Gross total tumor excision was possible in all patients. Six patients achieved disease control and two had recurrences. The complications of cerebrospinal fluid leak, infection, hematoma, or cranial nerve damage did not occur. After surgery, some patients experienced temporary symptoms caused by local swelling. The aesthetic result was considered good. Transfacial swing osteotomies provide a wide exposure to tumors that occur in the central skull base area. Excellent knowledge of the detailed anatomy of this region is paramount to the success of this surgery. The team concept is essential; it is built around the craniofacial surgeon and an experienced skull base neurosurgeon.

Planning and management of the Nido Reef Complex Oil Field development, Philippines

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

Harry, R.Y.

1981-01-01

As Operator for the Northeast Palawan consortium, Philippines-Cities Service, Inc., commenced the Philippines first commercial offshore oil production from the Nido Reef Complex Oil Field on February 1, 1979, some 11 months after a decision by management to start development. The relative speed at which design, fabrication, and construction were accomplished is attributed to the use of the concepts of project planning, task force approach, and project management. This paper presents the above concepts as applied to the Nido Complex.

The Complex Exposure History of a Very Large L/LL5 Chondrite Shower: Queen Alexandra Range 90201

NASA Technical Reports Server (NTRS)

Welten, K. C.; Nishiizumi, K.; Caffee, M. W.; Hillegonds, D. J.; Leya, I.; Wieler, R.; Mararik, J.

2004-01-01

Compared to iron meteorites, large stony meteorites (less than 100 kg) are relatively rare. Most large stony meteoroids fragment during atmospheric entry, producing large meteorite showers. Interestingly, many of these large chondrites, such as Bur Gheluai, Gold Basin, Jilin and Tsarev appear to have a complex exposure history with a first-stage exposure on the parent body. The question is whether complex exposure histories are simply more readily detected in large objects or large objects are more likely to experience a complex exposure. Investigation of these two hypotheses is the motivation for this work in which we report on the exposure history of QUE 90201, a large L/LL5 chondrite shower found near Queen Alexandra Range, Antarctica. Previous cosmogenic nuclide studies have led to the consensus that most of the approx. 2000 L5 and LL5 chondrites from the QUE area are derived from a single object with a pre-atmospheric radius of 1-2 m. The terrestrial age of the QUE 90201 shower was determined at 125 20 kyr. Here, we present a more complete set of cosmogenic radionuclide results in the metal and stone fractions of eleven L/LL5 chondrites from the QUE stranding area, as well as noble gases in seven of these samples. The main goal of this work is to unravel the cosmic-ray exposure history of the QUE 90201 meteoroid. In addition, we will discuss the pre-atmospheric size and exposure history of QUE 93013 (H5) and 93081 (H4) with similar shielding conditions as the QUE 90201 shower and a terrestrial age of 145 +/- 25 kyr.

Photo from Space Shuttle Mission 41-C of the Long Duration Exposure

NASA Image and Video Library

1989-12-06

Photo from Space Shuttle Mission 41-C of the Long Duration Exposure Facility (LDEF) deploy by CHALLENGER and a Langley Research Center (LRC) supplied art concept of the LDEF recovery by COLUMBIA during Space Shuttle Mission STS-32. LRC # L-89-11-720 for JSC # S89-50779

Perspective: Crowd-based breath analysis: assessing behavior, activity, exposures, and emotional response of people in groups

EPA Science Inventory

A new concept for exhaled breath analysis has emerged wherein groups, or even crowds of people are simultaneously sampled in enclosed environments to detect overall trends in their activities and recent exposures. The basic idea is to correlate the temporal profile of known breat...

40 CFR 79.63 - Fertility assessment/teratology.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., conception, and fertility. Since this is a one-generation test that ends with examination of full-term... females in both test and control groups are mated after nine weeks of exposure. Exposures for pregnant... subchronic toxicity study, pursuant to the provisions in § 79.62. (d) Limit test. If a test at one dose level...

40 CFR 79.63 - Fertility assessment/teratology.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., conception, and fertility. Since this is a one-generation test that ends with examination of full-term... females in both test and control groups are mated after nine weeks of exposure. Exposures for pregnant... subchronic toxicity study, pursuant to the provisions in § 79.62. (d) Limit test. If a test at one dose level...

40 CFR 79.63 - Fertility assessment/teratology.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., conception, and fertility. Since this is a one-generation test that ends with examination of full-term... females in both test and control groups are mated after nine weeks of exposure. Exposures for pregnant... subchronic toxicity study, pursuant to the provisions in § 79.62. (d) Limit test. If a test at one dose level...

40 CFR 79.63 - Fertility assessment/teratology.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., conception, and fertility. Since this is a one-generation test that ends with examination of full-term... females in both test and control groups are mated after nine weeks of exposure. Exposures for pregnant... subchronic toxicity study, pursuant to the provisions in § 79.62. (d) Limit test. If a test at one dose level...

40 CFR 79.63 - Fertility assessment/teratology.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., conception, and fertility. Since this is a one-generation test that ends with examination of full-term... females in both test and control groups are mated after nine weeks of exposure. Exposures for pregnant... subchronic toxicity study, pursuant to the provisions in § 79.62. (d) Limit test. If a test at one dose level...

The Articulation of Integration of Clinical and Basic Sciences in Concept Maps: Differences between Experienced and Resident Groups

ERIC Educational Resources Information Center

Vink, Sylvia; van Tartwijk, Jan; Verloop, Nico; Gosselink, Manon; Driessen, Erik; Bolk, Jan

2016-01-01

To determine the content of integrated curricula, clinical concepts and the underlying basic science concepts need to be made explicit. Preconstructed concept maps are recommended for this purpose. They are mainly constructed by experts. However, concept maps constructed by residents are hypothesized to be less complex, to reveal more tacit basic…

Vulnerability related to oral health in early childhood: a concept analysis.

PubMed

Mattheus, Deborah J

2010-09-01

This article is a report of the analysis of the concept of vulnerability and its relationship to oral health in early childhood. Poor oral health is a continued problem for children worldwide. Vulnerability increases the probability of poor oral health outcomes. The lack of clarity of the concept of vulnerability creates difficulty in understanding this multi-factoral condition. Data source included 34 articles covering the period 2000-2009 from a variety of disciplines, including nursing, dentistry, medicine and public health. The concept analysis was conducted using Rodgers' evolutionary method. The literature was analysed and a social ecology model was used to frame the discussion, recognizing family and community influences on children's oral health. The context of oral health in early childhood contributes to the changes in the concept vulnerability. The attributes are closely related to family and community factors and identified as limited parental income, parental education, community-based services and fluoride; and exposure to poor parental habits, parental neglect and harmful toxins. The primary antecedent is identified as a form of limited protection from exposure to various circumstances. Children with limited protection have increased vulnerability and greater probability of poor health outcomes. Nurses who understand the concept of vulnerability related to oral health and can identify factors that create protection and are capable of decreasing vulnerability through parent education, community awareness and policy changes that support children and families.

An analysis of species boundaries and biogeographic patterns in a cryptic species complex: the rotifer--Brachionus plicatilis.

PubMed

Suatoni, Elizabeth; Vicario, Saverio; Rice, Sean; Snell, Terry; Caccone, Adalgisa

2006-10-01

Since the advent of molecular phylogenetics, there is increasing evidence that many small aquatic and marine invertebrates--once believed to be single, cosmopolitan species--are in fact cryptic species complexes. Although the application of the biological species concept is central to the identification of species boundaries in these cryptic complexes, tests of reproductive isolation do not frequently accompany phylogenetic studies. Because different species concepts generally identify different boundaries in cryptic complexes, studies that apply multiple species concepts are needed to gain a more detailed understanding of patterns of diversification in these taxa. Here we explore different methods of empirically delimiting species boundaries in the salt water rotifer Brachionus plicatilis by comparing reproductive data (i.e., the traditional biological species concept) to phylogenetic data (the genealogical species concept). Based on a high degree of molecular sequence divergence and largely concordant genetic patterns in COI and ITS1, the genealogical species hypothesis indicates the existence of at least 14 species--the highest estimate for the group thus far. A test of the genealogical species concept with biological crosses shows a fairly high level of concordance, depending on the degree of reproductive success used to draw boundaries. The convergence of species concepts in this group suggests that many of the species within the group may be old. Although the diversity of the group is higher than previously understood, geographic distributions remain broad. Efficient passive dispersal has resulted in global distributions for many species with some evidence of isolation by distance over large geographic scales. These patterns concur with expectations that micro-meiofauna (0.1-1mm) have biogeographies intermediate to microbial organisms and large vertebrates. Sympatry of genetically distant strains is common.

Cohort Trends in Premarital First Births: What Role for the Retreat From Marriage?

PubMed Central

Wu, Lawrence L.; Shafer, Emily Fitzgibbons

2015-01-01

We examine cohort trends in premarital first births for U.S. women born between 1920 and 1964. The rise in premarital first births is often argued to be a consequence of the retreat from marriage, with later ages at first marriage resulting in more years of exposure to the risk of a premarital first birth. However, cohort trends in premarital first births may also reflect trends in premarital sexual activity, premarital conceptions, and how premarital conceptions are resolved. We decompose observed cohort trends in premarital first births into components reflecting cohort trends in (1) the age-specific risk of a premarital conception taken to term; (2) the age-specific risk of first marriages not preceded by such a conception, which will influence women’s years of exposure to the risk of a premarital conception; and (3) whether a premarital conception is resolved by entering a first marriage before the resulting first birth (a “shotgun marriage”). For women born between 1920–1924 and 1945–1949, increases in premarital first births were primarily attributable to increases in premarital conceptions. For women born between 1945–1949 and 1960–1964, increases in premarital first births were primarily attributable to declines in responding to premarital conceptions by marrying before the birth. Trends in premarital first births were affected only modestly by the retreat from marriages not preceded by conceptions—a finding that holds for both whites and blacks. These results cast doubt on hypotheses concerning “marriageable” men and instead suggest that increases in premarital first births resulted initially from increases in premarital sex and then later from decreases in responding to a conception by marrying before a first birth. PMID:24072609

Lagged kernel machine regression for identifying time windows of susceptibility to exposures of complex mixtures.

PubMed

Liu, Shelley H; Bobb, Jennifer F; Lee, Kyu Ha; Gennings, Chris; Claus Henn, Birgit; Bellinger, David; Austin, Christine; Schnaas, Lourdes; Tellez-Rojo, Martha M; Hu, Howard; Wright, Robert O; Arora, Manish; Coull, Brent A

2018-07-01

The impact of neurotoxic chemical mixtures on children's health is a critical public health concern. It is well known that during early life, toxic exposures may impact cognitive function during critical time intervals of increased vulnerability, known as windows of susceptibility. Knowledge on time windows of susceptibility can help inform treatment and prevention strategies, as chemical mixtures may affect a developmental process that is operating at a specific life phase. There are several statistical challenges in estimating the health effects of time-varying exposures to multi-pollutant mixtures, such as: multi-collinearity among the exposures both within time points and across time points, and complex exposure-response relationships. To address these concerns, we develop a flexible statistical method, called lagged kernel machine regression (LKMR). LKMR identifies critical exposure windows of chemical mixtures, and accounts for complex non-linear and non-additive effects of the mixture at any given exposure window. Specifically, LKMR estimates how the effects of a mixture of exposures change with the exposure time window using a Bayesian formulation of a grouped, fused lasso penalty within a kernel machine regression (KMR) framework. A simulation study demonstrates the performance of LKMR under realistic exposure-response scenarios, and demonstrates large gains over approaches that consider each time window separately, particularly when serial correlation among the time-varying exposures is high. Furthermore, LKMR demonstrates gains over another approach that inputs all time-specific chemical concentrations together into a single KMR. We apply LKMR to estimate associations between neurodevelopment and metal mixtures in Early Life Exposures in Mexico and Neurotoxicology, a prospective cohort study of child health in Mexico City.

Quantitative verification of the keyhole concept: a comparison of area of exposure in the parasellar region via supraorbital keyhole, frontotemporal pterional, and supraorbital approaches.

PubMed

Cheng, Cheng-Mao; Noguchi, Akio; Dogan, Aclan; Anderson, Gregory J; Hsu, Frank P K; McMenomey, Sean O; Delashaw, Johnny B

2013-02-01

This study was designed to determine if the "keyhole concept," proposed by Perneczky's group, can be verified quantitatively. Fourteen (3 bilateral and 8 unilateral) sides of embalmed latex-injected cadaveric heads were dissected via 3 sequential craniotomy approaches: supraorbital keyhole, frontotemporal pterional, and supraorbital. Three-dimensional cartesian coordinates were recorded using a stereotactic localizer. The orthocenter of the ipsilateral anterior clinoid process, the posterior clinoid process, and the contralateral anterior clinoid process are expressed as a center point (the apex). Seven vectors project from the apex to their corresponding target points in a radiating manner on the parasellar skull base. Each 2 neighboring vectors border what could be considered a triangle, and the total area of the 7 triangles sharing the same apex was geometrically expressed as the area of exposure in the parasellar region. Values are expressed as the mean ± SD (mm(2)). The total area of exposure was as follows: supraorbital keyhole 1733.1 ± 336.0, pterional 1699.3 ± 361.9, and supraorbital 1691.4 ± 342.4. The area of exposure on the contralateral side was as follows: supraorbital keyhole 602.2 ± 194.7, pterional 595.2 ± 228.0, and supraorbital 553.3 ± 227.2. The supraorbital keyhole skull flap was 2.0 cm(2), and the skull flap size ratio was 1:5:6.5 (supraorbital keyhole/pterional/supraorbital). The area of exposure of the parasellar region through the smaller supraorbital keyhole approach is as adequate as the larger pterional and supraorbital approaches. The keyhole concept can be verified quantitatively as follows: 1) a wide area of exposure on the skull base can be obtained through a small keyhole skull opening, and 2) the side opposite the opening can also be visualized.

Towards Integration of Ecosystem and Human Health: A Novel Conceptual Framework to Operationalise Ecological Public Health and to Incorporate Distal and Proximal Effects of Climate Change

NASA Astrophysics Data System (ADS)

Reis, S.; Fleming, L. E.; Beck, S.; Austen, M.; Morris, G.; White, M.; Taylor, T. J.; Orr, N.; Osborne, N. J.; Depledge, M.

2014-12-01

Conceptual models for problem framing in environmental (EIA) and health impact assessment (HIA) share similar concepts, but differ in their scientific or policy focus, methodologies and underlying causal chains, and the degree of complexity and scope. The Driver-Pressure-State-Impact-Response (DPSIR) framework used by the European Environment Agency, the OECD and others and the Integrated Science for Society and the Environment (ISSE) frameworks are widely applied in policy appraisal and impact assessments. While DPSIR is applied across different policy domains, the ISSE framework is used in Ecosystem Services assessments. The modified Driver-Pressure-State-Exposure-Effect-Action (DPSEEA) model extends DPSIR by separating exposure from effect, adding context as a modifier of effect, and susceptibility to exposures due to socio-economic, demographic or other determinants. While continuously evolving, the application of conceptual frameworks in policy appraisals mainly occurs within established discipline boundaries. However, drivers and environmental states, as well as policy measures and actions, affect both human and ecosystem receptors. Furthermore, unintended consequences of policy actions are seldom constrained within discipline or policy silos. Thus, an integrated conceptual model is needed, accounting for the full causal chain affecting human and ecosystem health in any assessment. We propose a novel model integrating HIA methods and ecosystem services in an attempt to operationalise the emerging concept of "Ecological Public Health." The conceptual approach of the ecosystem-enriched DPSEEA model ("eDPSEEA") has stimulated wide-spread debates and feedback. We will present eDPSEEA as a stakeholder engagement process and a conceptual model, using illustrative case studies of climate change as a starting point, not a complete solution, for the integration of human and ecosystem health impact assessment as a key challenge in a rapidly changing world. Rayner G and Lang T Ecological Public Health: Reshaping the Conditions for Good Health. Routledge Publishers; 2012.Reis S, Morris G, Fleming LE, Beck S, Taylor T, White M, Depledge MH, Steinle S, Sabel CE, Cowie H, Hurley F, Dick JMcP, Smith RI, Austen M (2013) Integrating Health & Environmental Impact Analysis. Public Health.

A Study on Contingency Learning in Introductory Physics Concepts

ERIC Educational Resources Information Center

Scaife, Thomas M.

2010-01-01

Instructors of physics often use examples to illustrate new or complex physical concepts to students. For any particular concept, there are an infinite number of examples, thus presenting instructors with a difficult question whenever they wish to use one in their teaching: which example will most effectively illustrate the concept so that student…

Students' Proficiency Scores within Multitrait Item Response Theory

ERIC Educational Resources Information Center

Scott, Terry F.; Schumayer, Daniel

2015-01-01

In this paper we present a series of item response models of data collected using the Force Concept Inventory. The Force Concept Inventory (FCI) was designed to poll the Newtonian conception of force viewed as a multidimensional concept, that is, as a complex of distinguishable conceptual dimensions. Several previous studies have developed…

How Do Parenting Concepts Vary within and between the Families?

ERIC Educational Resources Information Center

Roskam, Isabelle; Meunier, Jean Christophe

2009-01-01

How do parenting concepts vary within and between the families? The present study regards parenting as a complex family process by considering three concepts of parenting: styles, differential treatment and coparenting consistency. A main question was addressed: whether and how these parenting concepts vary within the families towards siblings or…

Rethinking the Concept of Acculturation

PubMed Central

Schwartz, Seth J.; Unger, Jennifer B.; Zamboanga, Byron L.; Szapocznik, José

2013-01-01

This article presents an expanded model of acculturation among international migrants and their immediate descendants. Acculturation is proposed as a multidimensional process consisting of the confluence among heritage-cultural and receiving-cultural practices, values, and identifications. The implications of this reconceptualization for the acculturation construct, as well as for its relationship to psychosocial and health outcomes, are discussed. In particular, an expanded operationalization of acculturation is needed to address the “immigrant paradox,” whereby international migrants with more exposure to the receiving cultural context report poorer mental and physical health outcomes. We discuss the role of ethnicity, cultural similarity, and discrimination in the acculturation process, offer an operational definition for context of reception, and call for studies on the role that context of reception plays in the acculturation process. The new perspective on acculturation presented in this article is intended to yield a fuller understanding of complex acculturation processes and their relationships to contextual and individual functioning. PMID:20455618

California Breast Cancer Prevention Initiatives: Setting a research agenda for prevention.

PubMed

Sutton, P; Kavanaugh-Lynch, M H E; Plumb, M; Yen, I H; Sarantis, H; Thomsen, C L; Campleman, S; Galpern, E; Dickenson, C; Woodruff, T J

2015-07-01

The environment is an underutilized pathway to breast cancer prevention. Current research approaches and funding streams related to breast cancer and the environment are unequal to the task at hand. We undertook the California Breast Cancer Prevention Initiatives, a four-year comprehensive effort to set a research agenda related to breast cancer, the environment, disparities and prevention. We identified 20 topics for Concept Proposals reflecting a life-course approach and the complex etiology of breast cancer; considering the environment as chemical, physical and socially constructed exposures that are experienced concurrently: at home, in the community and at work; and addressing how we should be modifying the world around us to promote a less carcinogenic environment. Redirecting breast cancer research toward prevention-oriented discovery could significantly reduce the incidence and associated disparities of the disease among future generations. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Interactions of microplastic debris throughout the marine ecosystem.

PubMed

Galloway, Tamara S; Cole, Matthew; Lewis, Ceri

2017-04-20

Marine microscopic plastic (microplastic) debris is a modern societal issue, illustrating the challenge of balancing the convenience of plastic in daily life with the prospect of causing ecological harm by careless disposal. Here we develop the concept of microplastic as a complex, dynamic mixture of polymers and additives, to which organic material and contaminants can successively bind to form an 'ecocorona', increasing the density and surface charge of particles and changing their bioavailability and toxicity. Chronic exposure to microplastic is rarely lethal, but can adversely affect individual animals, reducing feeding and depleting energy stores, with knock-on effects for fecundity and growth. We explore the extent to which ecological processes could be impacted, including altered behaviours, bioturbation and impacts on carbon flux to the deep ocean. We discuss how microplastic compares with other anthropogenic pollutants in terms of ecological risk, and consider the role of science and society in tackling this global issue in the future.

Low doses of ionizing radiation to mammalian cells may rather control than cause DNA damage

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

Feinendegen, L.E.; Bond, V.P.; Sondhaus, C.A.

This report examines the origin of tissue effects that may follow from different cellular responses to low-dose irradiation, using published data. Two principal categories of cellular responses are considered. One response category relates to the probability of radiation-induced DNA damage. The other category consists of low-dose induced metabolic changes that induce mechanisms of DNA damage mitigation, which do not operate at high levels of exposure. Modeled in this way, tissue is treated as a complex adaptive system. The interaction of the various cellular responses results in a net tissue dose-effect relation that is likely to deviate from linearity in themore » low-dose region. This suggests that the LNT hypothesis should be reexamined. This paper aims at demonstrating tissue effects as an expression of cellular responses, both damaging and defensive, in relation to the energy deposited in cell mass, by use of microdosimetric concepts.« less

Precision cut lung slices as an efficient tool for in vitro lung physio-pharmacotoxicology studies.

PubMed

Morin, Jean-Paul; Baste, Jean-Marc; Gay, Arnaud; Crochemore, Clément; Corbière, Cécile; Monteil, Christelle

2013-01-01

1.We review the specific approaches for lung tissue slices preparation and incubation systems and the research application fields in which lung slices proved to be a very efficient alternative to animal experimentation for biomechanical, physiological, pharmacological and toxicological approaches. 2.Focus is made on air-liquid interface dynamic organ culture systems that allow direct tissue exposure to complex aerosol and that best mimic in vivo lung tissue physiology. 3.A compilation of research applications in the fields of vascular and airway reactivity, mucociliary transport, polyamine transport, xenobiotic biotransformation, chemicals toxicology and complex aerosols supports the concept that precision cut lung slices are a very efficient tool maintaining highly differentiated functions similar to in vivo lung organ when kept under dynamic organ culture. They also have been successfully used for lung gene transfer efficiency assessment, for lung viral infection efficiency assessment, for studies of tissue preservation media and tissue post-conditioning to optimize lung tissue viability before grafting. 4.Taken all together, the reviewed studies point to a great interest for precision cut lung slices as an efficient and valuable alternative to in vivo lung organ experimentation.

Parental occupational paint exposure and risk of childhood leukemia in the offspring: Findings from the Childhood Leukemia International Consortium

PubMed Central

Bailey, Helen D; Fritschi, Lin; Metayer, Catherine; Infante-Rivard, Claire; Magnani, Corrado; Petridou, Eleni; Roman, Eve; Spector, Logan G; Kaatsch, Peter; Clavel, Jacqueline; Milne, Elizabeth; Dockerty, John D; Glass, Deborah C; Lightfoot, Tracy; Miligi, Lucia; Rudant, Jérémie; Baka, Margarita; Rondelli, Roberto; Amigou, Alicia; Simpson, Jill; Kang, Alice; Moschovi, Maria; Schüz, Joachim

2014-01-01

Purpose It has been suggested that parental occupational paint exposure around the time of conception or pregnancy increases the risk of childhood leukemia in the offspring. Methods We obtained individual level data from 13 case-control studies participating in the Childhood Leukemia International Consortium (CLIC). Occupational data were harmonized to a compatible format. Meta-analyses of study-specific odds ratios (ORs) were undertaken, as well as pooled analyses of individual data using unconditional logistic regression. Results Using individual data from fathers of 8,185 cases and 14,210 controls, the pooled OR for paternal exposure around conception and risk of acute lymphoblastic leukaemia (ALL) was 0.93 (95% confidence interval (CI) 0.76, 1.14). Analysis of data from 8,156 ALL case mothers and 14,568 control mothers produced a pooled OR of 0.81 (95% CI 0.39, 1.68) for exposure during pregnancy. For acute myeloid leukaemia (AML), the pooled ORs for paternal and maternal exposure were 0.96 (95% CI 0.65, 1.41) and 1.31 (95% CI 0.38, 4.47) respectively, based on data from 1,231 case and 11,392 control fathers and 1,329 case and 12,141 control mothers. Heterogeneity among the individual studies ranged from low to modest. Conclusions Null findings for paternal exposure for both ALL and AML are consistent with previous reports. Despite the large sample size, results for maternal exposure to paints in pregnancy were based on small numbers of exposed. Overall, we found no evidence that parental occupational exposure to paints increases the risk of leukemia in the offspring, but further data on home exposure are needed. PMID:25088805

A safe strategy to decrease fetal lead exposure in a woman with chronic intoxication.

PubMed

Leiba, Adi; Hu, Howard; Zheng, Amin; Kales, Stefanos N

2010-08-01

During pregnancy skeletal lead is mobilized by maternal bone turnover and can threaten fetal development. The exact strategy suggested to women of childbearing age, who were chronically exposed to lead, and, thus, have high bone lead burden, is not well established. We describe 4 years of follow-up of a 29-year-old woman with chronic lead intoxication. We (a) advised her to delay conception until 'toxicological clearance', (b) treated her with multiple courses of lead chelator, DMSA, and (c) prescribed oral calcium. Patient had low blood lead and protoporphyrin level during pregnancy until delivery. Delaying conception, lead chelation, and calcium supplementation can decrease fetal exposure.

The Winning Number: An Heuristic Approach with the Geogebra's Help

ERIC Educational Resources Information Center

Alves, Francisco Regis Vieira

2016-01-01

Admittedly, the study of Complex Analysis (CA) requires of the student considerable mental effort characterized by the mobilization of a related thought to the complex mathematical concepts. Thus, with the aid of the dynamic system Geogebra, we discuss in this paper a particular concept in CA. In fact, the notion of winding number v[f(gamma),P] =…

X-Ray Crystallography Analysis of Complexes Synthesized with Tris(2-pyridylmethyl)amine: A Laboratory Experiment for Undergraduate Students Integrating Interdisciplinary Concepts and Techniques

ERIC Educational Resources Information Center

Bazley, Isabel J.; Erie, Ellen A.; Feiereisel, Garrett M.; LeWarne, Christopher J.; Peterson, Jack M.; Sandquist, Katherine L.; Oshin, Kayode D.; Zeller, Matthias

2018-01-01

An integrated laboratory experiment applying concepts and techniques from organic chemistry, inorganic chemistry, and instrumental analysis is presented for use in the undergraduate curriculum. This experiment highlights the synthesis, characterization, and use of tris(2-pyridylmethyl)amine (TPMA) to make complexes with different metal salts. It…

"We're Trying to Take Action": Transformative Agency, Role Re-Mediation, and the Complexities of Youth Participatory Action Research

ERIC Educational Resources Information Center

Bertrand, Melanie; Durand, E. Sybil; Gonzalez, Taucia

2017-01-01

This article seeks to illuminate the complexity of youth participatory action research (YPAR) through the use of two concepts: (1) transformative agency, a collective initiative to address conflicts and contradictions in activity systems, and (2) role re-mediation, the disruption of power relations. We demonstrate that these concepts, in…

An Empirical Study of Gender Difference in the Relationship between Self-Concept and Mathematics Achievement

ERIC Educational Resources Information Center

Wang, Jianjun

2005-01-01

In the western literature, mathematics achievement and its related student self-concept are important education outcomes reciprocally linked and mutually reinforcing. The reciprocal relation model is examined in this study to assess its generalization in a cross-cultural setting. Hong Kong is the site of choice because of its exposure to…

Emerging Concept of Internationalisation in South African Higher Education: Conversations on Local and Global Exposure at the University of the Witwatersrand (Wits)

ERIC Educational Resources Information Center

Cross, Michael; Mhlanga, Ehpraim; Ojo, Emmanuel

2011-01-01

Rather than paying attention to the specific approaches emerging from different contexts, current debates tend to privilege Western-universalizing concepts of internationalisation, unproblematically accepted as globally established truths. In South Africa, where the legacy of isolation and the dominance of Eurocentricism in academia have inspired…

Differential Effects of Exposure to Maternal Obesity or Maternal Weight Loss during the Periconceptional Period in the Sheep on Insulin Signalling Molecules in Skeletal Muscle of the Offspring at 4 Months of Age

PubMed Central

Nicholas, Lisa M.; Morrison, Janna L.; Rattanatray, Leewen; Ozanne, Susan E.; Kleemann, Dave O.; Walker, Simon K.; MacLaughlin, Severence M.; Zhang, Song; Martin-Gronert, Malgorzata S.; McMillen, Isabella C.

2013-01-01

Exposure to maternal obesity before and/or throughout pregnancy may increase the risk of obesity and insulin resistance in the offspring in childhood and adult life, therefore, resulting in its transmission into subsequent generations. We have previously shown that exposure to maternal obesity around the time of conception alone resulted in increased adiposity in female lambs. Changes in the abundance of insulin signalling molecules in skeletal muscle and adipose tissue precede the development of insulin resistance and type 2 diabetes. It is not clear, however, whether exposure to maternal obesity results in insulin resistance in her offspring as a consequence of the impact of increased adiposity on skeletal muscle or as a consequence of the programming of specific changes in the abundance of insulin signalling molecules in this tissue. We have used an embryo transfer model in the sheep to investigate the effects of exposure to either maternal obesity or to weight loss in normal and obese mothers preceding and for one week after conception on the expression and abundance of insulin signalling molecules in muscle in the offspring. We found that exposure to maternal obesity resulted in lower muscle GLUT-4 and Ser 9 phospho-GSK3α and higher muscle GSK3α abundance in lambs when compared to lambs conceived in normally nourished ewes. Exposure to maternal weight loss in normal or obese mothers, however, resulted in lower muscle IRS1, PI3K, p110β, aPKCζ, Thr 642 phospho-AS160 and GLUT-4 abundance in the offspring. In conclusion, maternal obesity or weight loss around conception have each programmed specific changes on subsets of molecules in the insulin signalling, glucose transport and glycogen synthesis pathways in offspring. There is a need for a stronger evidence base to ensure that weight loss regimes in obese women seeking to become pregnant minimize the metabolic costs for the next generation. PMID:24386400

A generalized approach to complex networks

NASA Astrophysics Data System (ADS)

Costa, L. Da F.; da Rocha, L. E. C.

2006-03-01

This work describes how the formalization of complex network concepts in terms of discrete mathematics, especially mathematical morphology, allows a series of generalizations and important results ranging from new measurements of the network topology to new network growth models. First, the concepts of node degree and clustering coefficient are extended in order to characterize not only specific nodes, but any generic subnetwork. Second, the consideration of distance transform and rings are used to further extend those concepts in order to obtain a signature, instead of a single scalar measurement, ranging from the single node to whole graph scales. The enhanced discriminative potential of such extended measurements is illustrated with respect to the identification of correspondence between nodes in two complex networks, namely a protein-protein interaction network and a perturbed version of it.

STUDIES IN WORKMEN'S COMPENSATION AND RADIATION INJURY. VOLUME III, A REPORT ON IONIZING RADIATION RECORD KEEPING.

ERIC Educational Resources Information Center

Atomic Energy Commission, Washington, DC.

THE SUCCESSFUL OPERATION OF THE PERMISSIBLE LEVEL CONCEPT OF RADIATION CONTROL NECESSARILY ENTAILS A COMPREHENSIVE SYSTEM UNDER WHICH EXPOSURE MUST BE RECORDED AND EMPLOYEES NOTIFIED OF THEIR EXPOSURE HISTORY. IN AN INVESTIGATION OF RECORD KEEPING NECESSARY TO PROCESS RADIATION CLAIMS, QUESTIONNAIRES OR LETTERS WERE RECEIVED FROM 45 STATE AGENCIES…

In the Orchard: Farm Worker Children's Moral and Environmental Reasoning

ERIC Educational Resources Information Center

Severson, Rachel L.; Kahn, Peter H., Jr.

2010-01-01

In this study, farm worker children (N = 40) in 2nd and 5th grade were interviewed about (a) their conceptions and judgments of pesticide exposure and (b) their reasoning about the moral standing of nature. First, results showed that all participants negatively judged pesticide exposure based on moral obligatory criteria. Yet, most children…

Lasting Effects on Body Weight and Mammary Gland Gene Expression in Female Mice upon Early Life Exposure to n-3 but Not n-6 High-Fat Diets

EPA Science Inventory

Exposure to an imbalance of nutrients prior to conception and during critical developmental periods can have lasting consequences on physiological processes resulting in chronic diseases later in life. Developmental programming has been shown to involve structural and functional ...

The Zero Exposure Project: A Community Initiative Addressing Substance Abusing Women and Their Newborns

ERIC Educational Resources Information Center

Colen, Lisa Price

2007-01-01

The Zero Exposure Project is a public awareness campaign in Hillsborough County, Florida, designed to educate the public on the dangers of combining substance use with pregnancy. The authors describe the process of building the campaign from its original conception and share the challenges and successes of their collaborations with community…

Integrated information theory of consciousness: an updated account.

PubMed

Tononi, G

2012-01-01

This article presents an updated account of integrated information theory of consciousness (IIT) and some of its implications. IIT stems from thought experiments that lead to phenomenological axioms and ontological postulates. The information axiom asserts that every experience is one out of many, i.e. specific - it is what it is by differing in its particular way from a large repertoire of alternatives. The integration axiom asserts that each experience is one, i.e. unified - it cannot be reduced to independent components. The exclusion axiom asserts that every experience is definite - it is limited to particular things and not others and flows at a particular speed and resolution. IIT formalizes these intuitions with three postulates. The information postulate states that only "differences that make a difference" from the intrinsic perspective of a system matter: a mechanism generates cause-effect information if its present state has specific past causes and specific future effects within a system. The integration postulate states that only information that is irreducible matters: mechanisms generate integrated information only to the extent that the information they generate cannot be partitioned into that generated within independent components. The exclusion postulate states that only maxima of integrated information matter: a mechanism specifies only one maximally irreducible set of past causes and future effects - a concept. A complex is a set of elements specifying a maximally irreducible constellation of concepts, where the maximum is evaluated at the optimal spatio-temporal scale. Its concepts specify a maximally integrated conceptual information structure or quale, which is identical with an experience. Finally, changes in information integration upon exposure to the environment reflect a system's ability to match the causal structure of the world. After introducing an updated definition of information integration and related quantities, the article presents some theoretical considerations about the relationship between information and causation and about the relational structure of concepts within a quale. It also explores the relationship between the temporal grain size of information integration and the dynamic of metastable states in the corticothalamic complex. Finally, it summarizes how IIT accounts for empirical findings about the neural substrate of consciousness, and how various aspects of phenomenology may in principle be addressed in terms of the geometry of information integration.

Integrated information theory of consciousness: an updated account.

PubMed

Tononi, G

2012-12-01

This article presents an updated account of integrated information theory of consciousness (liT) and some of its implications. /IT stems from thought experiments that lead to phenomenological axioms (existence, compositionality, information, integration, exclusion) and corresponding ontological postulates. The information axiom asserts that every experience is spec~fic - it is what it is by differing in its particular way from a large repertoire of alternatives. The integration axiom asserts that each experience is unified- it cannot be reduced to independent components. The exclusion axiom asserts that every experience is definite - it is limited to particular things and not others and flows at a particular speed and resolution. /IT formalizes these intuitions with postulates. The information postulate states that only "differences that make a difference" from the intrinsic perpective of a system matter: a mechanism generates cause-effect information if its present state has selective past causes and selective future effects within a system. The integration postulate states that only information that is irreducible matters: mechanisms generate integrated information only to the extent that the information they generate cannot be partitioned into that generated within independent components. The exclusion postulate states that only maxima of integrated information matter: a mechanism specifies only one maximally irreducible set of past causes and future effects - a concept. A complex is a set of elements specifying a maximally irreducible constellation of concepts, where the maximum is evaluated over elements and at the optimal spatiatemporal scale. Its concepts specify a maximally integrated conceptual information structure or quale, which is identical with an experience. Finally, changes in information integration upon exposure to the environment reflect a system's ability to match the causal structure of the world. After introducing an updated definition of information integration and related quantities, the article presents some theoretical considerations about the relationship between information and causation and about the relational structure of concepts within a qua/e. It also explores the relationship between the temporal grain size of information integration and the dynamic of metastable states in the corticothalamic complex. Finally, it summarizes how liT accounts for empirical findings about the neural substrate of consciousness, and how various aspects of phenomenology may in principle be addressed in terms of the geometry of information integration.

Developing and applying the adverse outcome pathway ...

EPA Pesticide Factsheets

To support a paradigm shift in regulatory toxicology testing and risk assessment, the Adverse Outcome Pathway (AOP) concept has recently been proposed. This concept is similar to that for Mode of Action (MOA), describing a sequence of measurable key events triggered by a molecular initiating event in which a stressor interacts with a biological target. The resulting cascade of key events includes molecular, cellular, structural and functional changes in biological systems, resulting in a measurable adverse outcome. Thereby, an AOP ideally provides information relevant to chemical structure-activity relationships as a basis to predict effects for structurally similar compounds. AOPs could potentially also form the basis for qualitative and quantitative predictive modeling of the human adverse outcome resulting from molecular initiating or other key events for which higher-throughput testing methods are available or can be developed.A variety of cellular and molecular processes are known to be critical to normal function of the central (CNS) and peripheral nervous systems (PNS). Because of the biological and functional complexity of the CNS and PNS, it has been challenging to establish causative links and quantitative relationships between key events that comprise the pathways leading from chemical exposure to an adverse outcome in the nervous system. Following introduction of principles of the description and assessment of MOA and AOPs, examples of adverse out

Identity as a Moderator and Mediator of Communication Effects: Evidence and Implications for Message Design.

PubMed

Comello, Maria Leonora G; Farman, Lisa

2016-10-02

Advertisements, movies, and other forms of media content have potential to change behaviors and antecedent psychological states by appealing to identity. However, the mechanisms that are responsible for persuasive effects of such content have not been adequately specified. A recently proposed model of communication effects (the prism model) advances the study of mechanisms and argues that identity can serve as both a moderator and mediator of communication effects on behavior-relevant outcomes. These intervening roles are made possible by the complex nature of identity (including multiple self-concepts and sensitivity to cues) and messages that cue the importance of and activate particular self-concepts. This article builds on development of the model by presenting empirical support based on re-analysis of an experiment in which participants viewed either a more-stigmatizing or less-stigmatizing portrayal of a recovering drug addict. In line with the model's propositions, exposure to the less-stigmatizing condition led to increases in perspective taking which then led to more acceptance (mediation by identity), while level of perspective taking also changed the effect of condition on acceptance (moderation by identity). These results provide support for the model's proposition of simultaneous intervening roles. The authors discuss implications for strategic communication research and practice.

Economic Concepts for Nebraska's Junior High School Students.

ERIC Educational Resources Information Center

Myers, Dwain

This booklet identifies 14 basic economic concepts that have been selected for emphasis in junior high social studies classes in Nebraska. The booklet is accompanied by a series of related instructional units (see SO 011 416). In this booklet, the concepts are listed in a sequence from the simplest to the most complex, with concepts one through…

Student Difficulties in Learning Density: A Distributed Cognition Perspective

ERIC Educational Resources Information Center

Xu, Lihua; Clarke, David

2012-01-01

Density has been reported as one of the most difficult concepts for secondary school students (e.g. Smith et al. 1997). Discussion about the difficulties of learning this concept has been largely focused on the complexity of the concept itself or student misconceptions. Few, if any, have investigated how the concept of density was constituted in…

MALE REPRODUCTIVE EFFECTS OF SOLVENT AND FUEL EXPOSURE DURING AIRCRAFT MAINTENANCE

EPA Science Inventory

Few studies have addressed the effects of mixed, low level exposures to complex mixtures on a man's reproductive potential. In this prospective study, each subject was evaluated prior to first exposure and at 15 and 30 weeks after exposures had begun. A total of 50 men working ...

Recruitment and Retention Strategies for Environmental Exposure Studies: Lessons from the Detroit Exposure and Aerosol Research Study

EPA Science Inventory

The Environmental Protection Agency’s Detroit Exposure and Aerosol Research Study (DEARS) was a complex 3-year personal exposure study. The six geographically defined areas in the Detroit (Wayne County), Michigan, area used as study locations are ethnically diverse; the majority ...

Adverse outcome pathway networks II: Network analytics.

PubMed

Villeneuve, Daniel L; Angrish, Michelle M; Fortin, Marie C; Katsiadaki, Ioanna; Leonard, Marc; Margiotta-Casaluci, Luigi; Munn, Sharon; O'Brien, Jason M; Pollesch, Nathan L; Smith, L Cody; Zhang, Xiaowei; Knapen, Dries

2018-06-01

Toxicological responses to stressors are more complex than the simple one-biological-perturbation to one-adverse-outcome model portrayed by individual adverse outcome pathways (AOPs). Consequently, the AOP framework was designed to facilitate de facto development of AOP networks that can aid in the understanding and prediction of pleiotropic and interactive effects more common to environmentally realistic, complex exposure scenarios. The present study introduces nascent concepts related to the qualitative analysis of AOP networks. First, graph theory-based approaches for identifying important topological features are illustrated using 2 example AOP networks derived from existing AOP descriptions. Second, considerations for identifying the most significant path(s) through an AOP network from either a biological or risk assessment perspective are described. Finally, approaches for identifying interactions among AOPs that may result in additive, synergistic, or antagonistic responses (or previously undefined emergent patterns of response) are introduced. Along with a companion article (part I), these concepts set the stage for the development of tools and case studies that will facilitate more rigorous analysis of AOP networks, and the utility of AOP network-based predictions, for use in research and regulatory decision-making. The present study addresses one of the major themes identified through a Society of Environmental Toxicology and Chemistry Horizon Scanning effort focused on advancing the AOP framework. Environ Toxicol Chem 2018;37:1734-1748. © 2018 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America. © 2018 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

Self-organized minimum-energy structures for dielectric elastomer actuators

NASA Astrophysics Data System (ADS)

Kofod, G.; Paajanen, M.; Bauer, S.

2006-11-01

When a stretched elastomer is laminated to a flat plastic frame, a complex shape is formed, which is termed a minimum-energy structure. It is shown how self-organized structures can be applied in the development of actuators with complex, out-of-plane actuationmodes. This unusual concept is then demonstrated in the case of dielectric elastomer actuators. Among advantages of this approach are the simplicity in manufacturing, the potential complexity and sophistication of the manufactured structures, and the general benefits of the concept when applied to other electro-mechanically active materials.

Exposure to violent video games increases automatic aggressiveness.

PubMed

Uhlmann, Eric; Swanson, Jane

2004-02-01

The effects of exposure to violent video games on automatic associations with the self were investigated in a sample of 121 students. Playing the violent video game Doom led participants to associate themselves with aggressive traits and actions on the Implicit Association Test. In addition, self-reported prior exposure to violent video games predicted automatic aggressive self-concept, above and beyond self-reported aggression. Results suggest that playing violent video games can lead to the automatic learning of aggressive self-views.

Environmental risk factors and their role in the management of atopic dermatitis

PubMed Central

Kantor, Robert; Silverberg, Jonathan I.

2016-01-01

Introduction The etiology of atopic dermatitis (AD) is multifactorial with interaction between genetics, immune and environmental factors. Areas covered We review the role of prenatal exposures, irritants and pruritogens, pathogens, climate factors, including temperature, humidity, ultraviolet radiation, outdoor and indoor air pollutants, tobacco smoke exposure, water hardness, urban vs. rural living, diet, breastfeeding, probiotics and prebiotics on AD. Expert commentary The increased global prevalence of AD cannot be attributed to genetics alone, suggesting that evolving environmental exposures may trigger and/or flare disease in predisposed individuals. There is a complex interplay between different environmental factors, including individual use of personal care products and exposure to climate, pollution, food and other exogenous factors. Understanding these complex risk factors is crucial to developing targeted interventions to prevent the disease in millions. Moreover, patients require counseling on optimal regimens for minimization of exposure to irritants and pruritogens and other harmful exposures. PMID:27417220

Environmental risk factors and their role in the management of atopic dermatitis.

PubMed

Kantor, Robert; Silverberg, Jonathan I

2017-01-01

The etiology of atopic dermatitis (AD) is multifactorial with interaction between genetics, immune and environmental factors. Areas covered: We review the role of prenatal exposures, irritants and pruritogens, pathogens, climate factors, including temperature, humidity, ultraviolet radiation, outdoor and indoor air pollutants, tobacco smoke exposure, water hardness, urban vs. rural living, diet, breastfeeding, probiotics and prebiotics on AD. Expert commentary: The increased global prevalence of AD cannot be attributed to genetics alone, suggesting that evolving environmental exposures may trigger and/or flare disease in predisposed individuals. There is a complex interplay between different environmental factors, including individual use of personal care products and exposure to climate, pollution, food and other exogenous factors. Understanding these complex risk factors is crucial to developing targeted interventions to prevent the disease in millions. Moreover, patients require counseling on optimal regimens for minimization of exposure to irritants and pruritogens and other harmful exposures.

Revitalizing Complex Analysis: A Transition-to-Proof Course Centered on Complex Topics

ERIC Educational Resources Information Center

Sachs, Robert

2017-01-01

A new transition course centered on complex topics would help in revitalizing complex analysis in two ways: first, provide early exposure to complex functions, sparking greater interest in the complex analysis course; second, create extra time in the complex analysis course by eliminating the "complex precalculus" part of the course. In…

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

Barry D. Michael; Kathryn Held; Kevin Prise

The management of the risks of exposure of people to ionizing radiation is important in relation to its uses in industry and medicine, also to natural and man-made radiation in the environment. The vase majority of exposures are at a very low level of radiation dose. The risks are of inducing cancer in the exposed individuals and a smaller risk of inducing genetic damage that can be transmitted to children conceived after exposure. Studies of these risks in exposed population studies with any accuracy above the normal levels of cancer and genetic defects unless the dose levels are high. Inmore » practice, this means that our knowledge depends very largely on the information gained from the follow-up of the survivors of the atomic bombs dropped on Japanese cities. The risks calculated from these high-dose short-duration exposures then have to be projected down to the low-dose long-term exposures that apply generally. Recent research using cells in culture has revealed that the relations hi between high- and low-dose biological damage may be much more complex than had previously been thought. The aims of this and other projects in the DOE's Low-Dose Program are to gain an understanding of the biological actions of low-dose radiation, ultimately to provide information that will lead to more accurate quantification of low-dose risk. Our project is based on the concept that the processes by which radiation induces cancer start where the individual tracks of radiation impact on cells and tissues. At the dose levels of most low-dose exposures, these events are rare and any individual cells only ''sees'' radiation tracks at intervals averaging from weeks to years apart. This contracts with the atomic bomb exposures where, on average, each cell was hit by hundreds of tracks instantaneously. We have therefore developed microbeam techniques that enable us to target cells in culture with any number of tracks, from one upwards. This approach enables us to study the biological basis of the relationship between high- and low-dose exposures. The targeting approach also allows us to study very clearly a newly recognized effect of radiation, the ''bystander effect'', which appears to dominate some low-dose responses and therefore may have a significant role in low-dose risk mechanisms. Our project also addresses the concept that the background of naturally occurring oxidative damage that takes place continually in cells due to byproducts of metabolism may play a role in treatments that modify the levels of oxidative damage, either alone or in combination with low-dose irradiation. In this project, we have used human and rodent cell lines and each set of experiments has been carried out on a single cell type. However, low-dose research has to extend into tissues because signaling between cells of different types is likely to influence the responses. Our studies have therefore also included microbeam experiments using a model tissue system that consists of an explant of a small piece of pig ureter grown in culture. The structure of this tissue is similar to that of epithelium and there it relates to the tissues in which carcinoma arises. Our studies have been able to measure bystander-induced changes in the cells growing out from the tissue fragment after it has been targeted with a few radiation tracks to mimic a low-dose exposure.« less

Artificial gravity as a countermeasure for mitigating physiological deconditioning during long-duration space missions.

PubMed

Clément, Gilles R; Bukley, Angelia P; Paloski, William H

2015-01-01

In spite of the experience gained in human space flight since Yuri Gagarin's historical flight in 1961, there has yet to be identified a completely effective countermeasure for mitigating the effects of weightlessness on humans. Were astronauts to embark upon a journey to Mars today, the 6-month exposure to weightlessness en route would leave them considerably debilitated, even with the implementation of the suite of piece-meal countermeasures currently employed. Continuous or intermittent exposure to simulated gravitational states on board the spacecraft while traveling to and from Mars, also known as artificial gravity, has the potential for enhancing adaptation to Mars gravity and re-adaptation to Earth gravity. Many physiological functions are adversely affected by the weightless environment of spaceflight because they are calibrated for normal, Earth's gravity. Hence, the concept of artificial gravity is to provide a broad-spectrum replacement for the gravitational forces that naturally occur on the Earth's surface, thereby avoiding the physiological deconditioning that takes place in weightlessness. Because researchers have long been concerned by the adverse sensorimotor effects that occur in weightlessness as well as in rotating environments, additional study of the complex interactions among sensorimotor and other physiological systems in rotating environments must be undertaken both on Earth and in space before artificial gravity can be implemented.

Myosin light chain kinase and Src control membrane dynamics in volume recovery from cell swelling

PubMed Central

Barfod, Elisabeth T.; Moore, Ann L.; Van de Graaf, Benjamin G.; Lidofsky, Steven D.

2011-01-01

 The expansion of the plasma membrane, which occurs during osmotic swelling of epithelia, must be retrieved for volume recovery, but the mechanisms are unknown. Here we have identified myosin light chain kinase (MLCK) as a regulator of membrane internalization in response to osmotic swelling in a model liver cell line. On hypotonic exposure, we found that there was time-dependent phosphorylation of the MLCK substrate myosin II regulatory light chain. At the sides of the cell, MLCK and myosin II localized to swelling-induced membrane blebs with actin just before retraction, and MLCK inhibition led to persistent blebbing and attenuated cell volume recovery. At the base of the cell, MLCK also localized to dynamic actin-coated rings and patches upon swelling, which were associated with uptake of the membrane marker FM4-64X, consistent with sites of membrane internalization. Hypotonic exposure evoked increased biochemical association of the cell volume regulator Src with MLCK and with the endocytosis regulators cortactin and dynamin, which colocalized within these structures. Inhibition of either Src or MLCK led to altered patch and ring lifetimes, consistent with the concept that Src and MLCK form a swelling-induced protein complex that regulates volume recovery through membrane turnover and compensatory endocytosis under osmotic stress. PMID:21209319

Estimating topological properties of weighted networks from limited information.

PubMed

Cimini, Giulio; Squartini, Tiziano; Gabrielli, Andrea; Garlaschelli, Diego

2015-10-01

A problem typically encountered when studying complex systems is the limitedness of the information available on their topology, which hinders our understanding of their structure and of the dynamical processes taking place on them. A paramount example is provided by financial networks, whose data are privacy protected: Banks publicly disclose only their aggregate exposure towards other banks, keeping individual exposures towards each single bank secret. Yet, the estimation of systemic risk strongly depends on the detailed structure of the interbank network. The resulting challenge is that of using aggregate information to statistically reconstruct a network and correctly predict its higher-order properties. Standard approaches either generate unrealistically dense networks, or fail to reproduce the observed topology by assigning homogeneous link weights. Here, we develop a reconstruction method, based on statistical mechanics concepts, that makes use of the empirical link density in a highly nontrivial way. Technically, our approach consists in the preliminary estimation of node degrees from empirical node strengths and link density, followed by a maximum-entropy inference based on a combination of empirical strengths and estimated degrees. Our method is successfully tested on the international trade network and the interbank money market, and represents a valuable tool for gaining insights on privacy-protected or partially accessible systems.

Estimating topological properties of weighted networks from limited information

NASA Astrophysics Data System (ADS)

Cimini, Giulio; Squartini, Tiziano; Gabrielli, Andrea; Garlaschelli, Diego

2015-10-01

A problem typically encountered when studying complex systems is the limitedness of the information available on their topology, which hinders our understanding of their structure and of the dynamical processes taking place on them. A paramount example is provided by financial networks, whose data are privacy protected: Banks publicly disclose only their aggregate exposure towards other banks, keeping individual exposures towards each single bank secret. Yet, the estimation of systemic risk strongly depends on the detailed structure of the interbank network. The resulting challenge is that of using aggregate information to statistically reconstruct a network and correctly predict its higher-order properties. Standard approaches either generate unrealistically dense networks, or fail to reproduce the observed topology by assigning homogeneous link weights. Here, we develop a reconstruction method, based on statistical mechanics concepts, that makes use of the empirical link density in a highly nontrivial way. Technically, our approach consists in the preliminary estimation of node degrees from empirical node strengths and link density, followed by a maximum-entropy inference based on a combination of empirical strengths and estimated degrees. Our method is successfully tested on the international trade network and the interbank money market, and represents a valuable tool for gaining insights on privacy-protected or partially accessible systems.

Inhaled Pollutants: The Molecular Scene behind Respiratory and Systemic Diseases Associated with Ultrafine Particulate Matter

PubMed Central

Traboulsi, Hussein; Guerrina, Necola; Iu, Matthew; Maysinger, Dusica; Ariya, Parisa; Baglole, Carolyn J.

2017-01-01

Air pollution of anthropogenic origin is largely from the combustion of biomass (e.g., wood), fossil fuels (e.g., cars and trucks), incinerators, landfills, agricultural activities and tobacco smoke. Air pollution is a complex mixture that varies in space and time, and contains hundreds of compounds including volatile organic compounds (e.g., benzene), metals, sulphur and nitrogen oxides, ozone and particulate matter (PM). PM0.1 (ultrafine particles (UFP)), those particles with a diameter less than 100 nm (includes nanoparticles (NP)) are considered especially dangerous to human health and may contribute significantly to the development of numerous respiratory and cardiovascular diseases such as chronic obstructive pulmonary disease (COPD) and atherosclerosis. Some of the pathogenic mechanisms through which PM0.1 may contribute to chronic disease is their ability to induce inflammation, oxidative stress and cell death by molecular mechanisms that include transcription factors such as nuclear factor κB (NF-κB) and nuclear factor (erythroid-derived 2)-like 2 (Nrf2). Epigenetic mechanisms including non-coding RNA (ncRNA) may also contribute towards the development of chronic disease associated with exposure to PM0.1. This paper highlights emerging molecular concepts associated with inhalational exposure to PM0.1 and their ability to contribute to chronic respiratory and systemic disease. PMID:28125025

The Species Problem and the Value of Teaching and the Complexities of Species

ERIC Educational Resources Information Center

Chung, Carl

2004-01-01

Discussions on species taxa directly refer to a range of complex biological phenomena. Given these phenomena, biologists have developed and continue to appeal to a series of species concepts and do not have a clear definition for it as each species concept tells us part of the story or helps the biologists to explain and understand a subset of…

Complex Dynamic Systems View on Conceptual Change: How a Picture of Students' Intuitive Conceptions Accrue from Dynamically Robust Task Dependent Learning Outcomes

ERIC Educational Resources Information Center

Koponen, Ismo T.; Kokkonen, Tommi; Nousiainen, Maiji

2017-01-01

We discuss here conceptual change and the formation of robust learning outcomes from the viewpoint of complex dynamic systems (CDS). The CDS view considers students' conceptions as context dependent and multifaceted structures which depend on the context of their application. In the CDS view the conceptual patterns (i.e. intuitive conceptions…

The Nature of Conceptual Understanding in Biomedicine: The Deep Structure of Complex Ideas and the Development of Misconceptions. Technical Report No. 440.

ERIC Educational Resources Information Center

Feltovich, Paul J.; And Others

This report presents a general framework for studying the acquisition and cognitive representation of biomedical concepts and analyzing the nature and development of misconceptions. The central approach of the report is a selective and highly concentrated analysis of the true nature of clusters of complex concepts and the manner in which they are…

Adaptive Prompts for Learning Evolution with Worked Examples--Highlighting the Students between the "Novices" and the "Experts" in a Classroom

ERIC Educational Resources Information Center

Neubrand, Charlotte; Borzikowsky, Christoph; Harms, Ute

2016-01-01

Evolutionary theory constitutes the overarching concept in biology. There is hardly any other concept that is more complex, and causes more difficulties in learning and teaching. One instructional approach in optimizing the learning of complex topics is to use worked examples combined with self-explanation prompts that fit to the prior knowledge…

A structural equation model of soil metal bioavailability to earthworms: confronting causal theory and observations using a laboratory exposure to field-contaminated soils.

PubMed

Beaumelle, Léa; Vile, Denis; Lamy, Isabelle; Vandenbulcke, Franck; Gimbert, Frédéric; Hedde, Mickaël

2016-11-01

Structural equation models (SEM) are increasingly used in ecology as multivariate analysis that can represent theoretical variables and address complex sets of hypotheses. Here we demonstrate the interest of SEM in ecotoxicology, more precisely to test the three-step concept of metal bioavailability to earthworms. The SEM modeled the three-step causal chain between environmental availability, environmental bioavailability and toxicological bioavailability. In the model, each step is an unmeasured (latent) variable reflected by several observed variables. In an exposure experiment designed specifically to test this SEM for Cd, Pb and Zn, Aporrectodea caliginosa was exposed to 31 agricultural field-contaminated soils. Chemical and biological measurements used included CaC12-extractable metal concentrations in soils, free ion concentration in soil solution as predicted by a geochemical model, dissolved metal concentration as predicted by a semi-mechanistic model, internal metal concentrations in total earthworms and in subcellular fractions, and several biomarkers. The observations verified the causal definition of Cd and Pb bioavailability in the SEM, but not for Zn. Several indicators consistently reflected the hypothetical causal definition and could thus be pertinent measurements of Cd and Pb bioavailability to earthworm in field-contaminated soils. SEM highlights that the metals present in the soil solution and easily extractable are not the main source of available metals for earthworms. This study further highlights SEM as a powerful tool that can handle natural ecosystem complexity, thus participating to the paradigm change in ecotoxicology from a bottom-up to a top-down approach. Copyright © 2016 Elsevier B.V. All rights reserved.

The Pathogenesis of Autoimmune Liver Disease.

PubMed

Arndtz, Katherine; Hirschfield, Gideon M

Autoimmune liver disease (AILD) encompasses 3 main distinct clinical diseases: autoimmune hepatitis, primary biliary cholangitis (formally known as cirrhosis, PBC) and primary sclerosing cholangitis (PSC). These conditions are an important, yet under-appreciated cause of patient morbidity and mortality with ongoing unmet needs for further research and clinical advances. There is observational evidence for genetic predisposition, with all 3 conditions being more common in first degree relatives. AILD is associated with the presence of auto-antibodies and higher risks of other non-hepatic auto-immune conditions. Genetic risk association studies have identified HLA and non-HLA risk loci for the development of disease, with some HLA loci providing prognostic information. This re-enforces the concept that genetic predisposition to autoimmunity is important, likely in the context of environmental exposures. Such environmental triggers are unclear but relevant risks include smoking, drug and xenobiotic exposure as well as the complexities of the microbiome. There is evidence for a loss of immune tolerance to self-antigens playing a part in the development of these conditions. In particular the IL-2 and IL-12 regulatory pathways have been implicated in pre-disposing to an unopposed inflammatory response within the liver. Main immunological themes revolve around loss of immune tolerance leading to T-cell mediated injury, imbalance in the regulation of immune cells and defective immune response to foreign antigens. For PBC and PSC, there is then the added complexity of the consequences of cholestasis on hepato-biliary injury, immune regulation and liver fibrosis. Whilst specific disease causes and triggers are still lacking, AILD arises on the background of collective genetic and environmental risk, leading to chronic and abnormal hepato-biliary immune responses. Effective and more rational therapy will ultimately be developed when the multiple pathways to liver injury are better understood. © 2016 S. Karger AG, Basel.

Constraining coastal change: A morpho-sedimentological concept to infer sea-level oscillation

NASA Astrophysics Data System (ADS)

Mauz, Barbara; Shen, Zhixiong

2016-04-01

One of the responders to Milankovitch-scale climate changes is sea level which, in turn, is a driver of coastal change. In literature, the sedimentary sequences representing the coastal change are often linked to high sea-level stands, to intermediate sea-level positions or to regressive shorelines. We note apparent contradictions that indicate a lack of concept and inconsistent usage of sea level-related terms. To overcome this, we combine an integrated morpho-sedimentological concept for microtidal, mid-latitudinal coasts with chronologies based on Bayesian statistics. The concept regards the coastal sedimentary system as a depositional complex consisting of shallow-marine, aeolian and alluvial facies. These facies are in juxtaposition and respond simultaneously to external forcing. Bayesian statistics constrains the timing of the sequence based on optical or radiocarbon ages. Here, we present the site Hergla located on the North African coast of the central Mediterranean Sea as a case study to illustrate how the approach helps eliminating contradictions. The site has been cited frequently for confirming the hypothesis of a global two peak sea-level highstand during the last interglacial (MIS 5e). The ~2 km cliff exposure at Hergla was surveyed, mapped, logged and sampled for further describing the sediments and their depositional environment through thin section and Bayesian modelling of optical ages. Using our concept based on sequence stratigraphy tools, the section is interpreted as representing a coastal barrier with two bounding surfaces in the succession. Both surfaces mark the falling sea level of, first, MIS 5e and, second, MIS 5a and hence bound the falling stage system tract of a forced regression. Part of the deposits between the two surfaces are pulled up onto the shoulder of a small rising horst and the associated tectonic event coincided with the MIS 5a sea-level rise enhancing locally the accommodation space for a second foreshore environment. Our presentation will provide theoretical background of the concept and critically discuss the global dataset for last interglacial sea-level oscillations using both the stratigraphic record and age distributions.

Concept "Medical Museum" as a Sociocultural Phenomenon

ERIC Educational Resources Information Center

Chizh, Nina V.; Slyshkin, Gennady G.; Zheltukhina, Marina R.; Privalova, Irina V.; Kravchenko, Olga A.

2016-01-01

The article examines the concept "medical museum" as a sociocultural phenomenon. The register of medical museums in Russia makes the material of research. The complex methods of analysis of the concept "medical museum" are used. The philosophical, historical, cultural, structural, communicative and semantic analysis is carried…

Brain Research and Learning.

ERIC Educational Resources Information Center

Claycomb, Mary

Current research on brain activity has many implications for educators. The triune brain concept and the left and right hemisphere concepts are among the many complex theories evolving from experimentation and observation. The triune brain concept suggests that the human forebrain has expanded while retaining three structurally unique formations…

Computer-Assisted Concept Mapping: Visual Aids for Knowledge Construction.

PubMed

Mammen, Jennifer R

2016-07-01

Concept mapping is a visual representation of ideas that facilitates critical thinking and is applicable to many areas of nursing education. Computer-assisted concept maps are more flexible and less constrained than traditional paper methods, allowing for analysis and synthesis of complex topics and larger amounts of data. Ability to iteratively revise and collaboratively create computerized maps can contribute to enhanced interpersonal learning. However, there is limited awareness of free software that can support these types of applications. This educational brief examines affordances and limitations of computer-assisted concept maps and reviews free software for development of complex, collaborative malleable maps. Free software, such as VUE, XMind, MindMaple, and others, can substantially contribute to the utility of concept mapping for nursing education. Computerized concept-mapping is an important tool for nursing and is likely to hold greater benefit for students and faculty than traditional pen-and-paper methods alone. [J Nurs Educ. 2016;55(7):403-406.]. Copyright 2016, SLACK Incorporated.

Used tire recycling to produce granulates: evaluation of occupational exposure to chemical agents.

PubMed

Savary, Barbara; Vincent, Raymond

2011-10-01

Exposure was assessed in four facilities where used tires are turned into rubber granulates. Particulate exposure levels were measured using filter samples and gravimetric analysis. In parallel, volatile organic compounds (VOCs) screening was carried out using samples taken on activated carbon supports, followed by an analysis using a gas chromatograph coupled to a spectrometric detector. The exposure level medians are between 0.58 and 3.95 mg m(-3). Clogging of the textile fiber separation systems can lead to worker exposure; in this case, the measured concentrations can reach 41 mg m(-3). However, in contrast to the data in the literature, VOC levels >1 p.p.m. were not detected. The particulate mixtures deposited on the installation surfaces are complex; some of the chemical agents are toxic to humans. The results of this study indicate significant exposure to complex mixtures of rubber dust. Optimizing exhaust ventilation systems inside the shredders, with a cyclone for example, is essential for reducing the exposure of workers in this rapidly developing sector.

Characterizing Risks of Exposures to Combined Stressors: An Overview

EPA Science Inventory

Cumulative risk assessment (CRA) addresses the impacts of multiple chemical and nonchemical stressors on communities, resulting from complex exposures for populations with a variety of vulnerabilities. These efforts focus on real world exposure scenarios and applications that ra...

Landscape analysis of pesticide use patterns and ecological exposure

EPA Science Inventory

Background/Question/Methods The pesticide exposure landscape in the US is spatially and temporally complex. Researchers studying ecological exposure and effects of pesticides must consider a number of dimensions when framing experiments and conducting assessments. These dimension...

Controlled human exposures to diesel exhaust

EPA Science Inventory

Diesel exhaust (DE) is a complex mixture of gaseous and particulate compounds resulting from an incomplete combustion of diesel fuel. Controlled human exposures to DE and diesel exhaust particles (DEP) have contributed to understanding health effects. Such exposure studies of h...

Electrical stimulation vs thermal effects in a complex electromagnetic environment.

PubMed

Paniagua, Jesús M; Rufo, Montaña; Jiménez, Antonio; Antolín, Alicia; Sánchez, Miguel

2009-08-01

Studies linking exposure to low levels of radiofrequencies with adverse health effects, notwithstanding their present apparent inconsistency, have contributed to a steady improvement in the quality of evaluating that exposure. In complex electromagnetic environments, with a multitude of emissions of different frequencies acting simultaneously, knowledge of the spectral content is fundamental to evaluating human exposure to non-ionizing radiation. In the present work, we quantify the most significant spectral components in the frequency band 0.5-2200 MHz in an urban area. The measurements were made with a spectrum analyzer and monopole, biconical, and log-periodic antennas. Power density levels were calculated separately for the medium wave, short wave, and frequency modulation radio broadcasting bands, and for the television and GSM, DCS, and UMTS mobile telephony bands. The measured levels were compared with the ICNIRP reference levels for exposure to multiple frequency sources for thermal effects and electrical stimulation. The results showed the criterion limiting exposure on the basis of preventing electrical stimulation of peripheral nerves and muscles to be stricter (exposure quotient 24.7 10(-4)) than that based on thermal considerations (exposure quotient 0.16 10(-4)). The bands that contribute most to the latter are short wave, with 46.2%, and mobile telephony with 32.6% of the total exposure. In a complex electromagnetic environment, knowledge of the radiofrequency spectrum is essential in order to quantify the contribution of each type of emission to the public's exposure. It is also necessary to evaluate the electrical effects as well as the thermal effects because the criterion to limit exposure on the basis of the effect of the electrical stimulation of tissues is stricter than that based on thermal effects.

Analysis of the Effect of Sequencing Lecture and Laboratory Instruction on Student Learning and Motivation Towards Learning Chemistry in an Organic Chemistry Lecture Course

ERIC Educational Resources Information Center

Pakhira, Deblina

2012-01-01

Exposure to organic chemistry concepts in the laboratory can positively affect student performance, learning new chemistry concepts and building motivation towards learning chemistry in the lecture. In this study, quantitative methods were employed to assess differences in student performance, learning, and motivation in an organic chemistry…

A developmental approach to complex PTSD: childhood and adult cumulative trauma as predictors of symptom complexity.

PubMed

Cloitre, Marylene; Stolbach, Bradley C; Herman, Judith L; van der Kolk, Bessel; Pynoos, Robert; Wang, Jing; Petkova, Eva

2009-10-01

Exposure to multiple traumas, particularly in childhood, has been proposed to result in a complex of symptoms that includes posttraumatic stress disorder (PTSD) as well as a constrained, but variable group of symptoms that highlight self-regulatory disturbances. The relationship between accumulated exposure to different types of traumatic events and total number of different types of symptoms (symptom complexity) was assessed in an adult clinical sample (N = 582) and a child clinical sample (N = 152). Childhood cumulative trauma but not adulthood trauma predicted increasing symptom complexity in adults. Cumulative trauma predicted increasing symptom complexity in the child sample. Results suggest that Complex PTSD symptoms occur in both adult and child samples in a principled, rule-governed way and that childhood experiences significantly influenced adult symptoms. Copyright © 2009 International Society for Traumatic Stress Studies.

Maternal exposure to brominated flame retardants and infant Apgar Scores

PubMed Central

Terrell, Metrecia L.; Hartnett, Kathleen P.; Lim, Hyeyeun; Wirth, Julie; Marcus, Michele

2014-01-01

Brominated flame retardants (BFRs) and other persistent organic pollutants have been associated with adverse health outcomes in humans and may be particularly toxic to the developing fetus. We investigated the association between in utero polybrominated biphenyl (PBB) and polychlorinated biphenyl (PCB) exposures and infant Apgar scores in a cohort of Michigan residents exposed to PBB through contaminated food after an industrial accident. PBB and PCB concentrations were measured in serum at the time the women were enrolled in the cohort. PBB concentrations were also estimated at the time of conception for each pregnancy using a validated elimination model. Apgar scores, a universal measure of infant health at birth, measured at 1 and 5 minutes, were taken from birth certificates for 613 offspring born to 330 women. Maternal PCB concentrations at enrollment were not associated with below–median Apgar scores in this cohort. However, maternal PBB exposure was associated with a dose–related increase in the odds of a below–median Apgar score at 1 minute and 5 minutes. Among infants whose mothers had an estimated PBB at conception above the limit of detection of 1 part per billion, the odds ratio was 2.32 (95 % CI: 1.22– 4.40); for those with PBB ≥ 2.5 ppb the OR=2.62 (95% CI: 1.38-4.96; test for trend p< 0.01). Likewise, the odds of a below–median 5–minute Apgar increased with higher maternal PBB at conception. It remains critical that future studies examine possible relationships between in utero exposures to brominated compounds and adverse health outcomes. PMID:25203650

Selection of appropriate tumour data sets for Benchmark Dose Modelling (BMD) and derivation of a Margin of Exposure (MoE) for substances that are genotoxic and carcinogenic: considerations of biological relevance of tumour type, data quality and uncertainty assessment.

PubMed

Edler, Lutz; Hart, Andy; Greaves, Peter; Carthew, Philip; Coulet, Myriam; Boobis, Alan; Williams, Gary M; Smith, Benjamin

2014-08-01

This article addresses a number of concepts related to the selection and modelling of carcinogenicity data for the calculation of a Margin of Exposure. It follows up on the recommendations put forward by the International Life Sciences Institute - European branch in 2010 on the application of the Margin of Exposure (MoE) approach to substances in food that are genotoxic and carcinogenic. The aims are to provide practical guidance on the relevance of animal tumour data for human carcinogenic hazard assessment, appropriate selection of tumour data for Benchmark Dose Modelling, and approaches for dealing with the uncertainty associated with the selection of data for modelling and, consequently, the derived Point of Departure (PoD) used to calculate the MoE. Although the concepts outlined in this article are interrelated, the background expertise needed to address each topic varies. For instance, the expertise needed to make a judgement on biological relevance of a specific tumour type is clearly different to that needed to determine the statistical uncertainty around the data used for modelling a benchmark dose. As such, each topic is dealt with separately to allow those with specialised knowledge to target key areas of guidance and provide a more in-depth discussion on each subject for those new to the concept of the Margin of Exposure approach. Copyright © 2013 ILSI Europe. Published by Elsevier Ltd.. All rights reserved.

Maternal occupational exposure to polycyclic aromatic hydrocarbons and craniosynostosis among offspring in the National Birth Defects Prevention Study.

PubMed

O'Brien, Jacqueline L; Langlois, Peter H; Lawson, Christina C; Scheuerle, Angela; Rocheleau, Carissa M; Waters, Martha A; Symanski, Elaine; Romitti, Paul A; Agopian, A J; Lupo, Philip J

2016-01-01

Evidence in animal models and humans suggests that exposure to polycyclic aromatic hydrocarbons (PAHs) may lead to birth defects. To our knowledge, this relationship has not been evaluated for craniosynostosis, a birth defect characterized by the premature closure of sutures in the skull. We conducted a case-control study to examine associations between maternal occupational exposure to PAHs and craniosynostosis. We used data from craniosynostosis cases and control infants in the National Birth Defects Prevention Study (NBDPS) with estimated delivery dates from 1997 to 2002. Industrial hygienists reviewed occupational data from the computer-assisted telephone interview and assigned a yes/no rating of probable occupational PAH exposure for each job from 1 month before conception through delivery. We used logistic regression to assess the association between occupational exposure to PAHs and craniosynostosis. The prevalence of exposure was 5.3% in case mothers (16/300) and 3.7% in control mothers (107/2,886). We observed a positive association between exposure to PAHs during the 1 month before conception through the third month of pregnancy and craniosynostosis (odds ratio [OR] = 1.75; 95% confidence interval [CI], 1.01-3.05) after adjusting for maternal age and maternal education. The number of cases for each craniosynostosis subtype limited subtype analyses to sagittal craniosynostosis; the odds ratio remained similar (OR = 1.76, 95% CI, 0.82-3.75), but was not significant. Our findings support a moderate association between maternal occupational exposure to PAHs and craniosynostosis. Additional work is needed to better characterize susceptibility and the role PAHs may play on specific craniosynostosis subtypes. © 2015 Wiley Periodicals, Inc.

Gene and protein expression following exposure to radiofrequency fields from mobile phones.

PubMed

Vanderstraeten, Jacques; Verschaeve, Luc

2008-09-01

Since 1999, several articles have been published on genome-wide and/or proteome-wide response after exposure to radiofrequency (RF) fields whose signal and intensities were similar to or typical of those of currently used mobile telephones. These studies were performed using powerful high-throughput screening techniques (HTSTs) of transcriptomics and/or proteomics, which allow for the simultaneous screening of the expression of thousands of genes or proteins. We reviewed these HTST-based studies and compared the results with currently accepted concepts about the effects of RF fields on gene expression. In this article we also discuss these last in light of the recent concept of microwave-assisted chemistry. To date, the results of HTST-based studies of transcriptomics and/or proteomics after exposure to RF fields relevant to human exposure are still inconclusive, as most of the positive reports are flawed by methodologic imperfections or shortcomings. In addition, when positive findings were reported, no precise response pattern could be identified in a reproducible way. In particular, results from HTST studies tend to exclude the role of a cell stressor for exposure to RF fields at nonthermal intensities. However, on the basis of lessons from microwave-assisted chemistry, we can assume that RF fields might affect heat-sensitive gene or protein expression to an extent larger than would be predicted from temperature change only. But in all likelihood, this would concern intensities higher than those relevant to usual human exposure. The precise role of transcriptomics and proteomics in the screening of bioeffects from exposure to RF fields from mobile phones is still uncertain in view of the lack of positively identified phenotypic change and the lack of theoretical, as well as experimental, arguments for specific gene and/or protein response patterns after this kind of exposure.

Personality Traits in Miners with Past Occupational Elemental Mercury Exposure

PubMed Central

Grum, Darja Kobal; Kobal, Alfred B.; Arnerič, Niko; Horvat, Milena; Ženko, Bernard; Džeroski, Sašo; Osredkar, Joško

2006-01-01

In this study, we evaluated the impact of long-term occupational exposure to elemental mercury vapor (Hg0) on the personality traits of ex-mercury miners. Study groups included 53 ex-miners previously exposed to Hg0 and 53 age-matched controls. Miners and controls completed the self-reporting Eysenck Personality Questionnaire and the Emotional States Questionnaire. The relationship between the indices of past occupational exposure and the observed personality traits was evaluated using Pearson’s correlation coefficient and on a subgroup level by machine learning methods (regression trees). The ex-mercury miners were intermittently exposed to Hg0 for a period of 7–31 years. The means of exposure-cycle urine mercury (U-Hg) concentrations ranged from 20 to 120 μg/L. The results obtained indicate that ex-miners tend to be more introverted and sincere, more depressive, more rigid in expressing their emotions and are likely to have more negative self-concepts than controls, but no correlations were found with the indices of past occupational exposure. Despite certain limitations, results obtained by the regression tree suggest that higher alcohol consumption per se and long-term intermittent, moderate exposure to Hg0 (exposure cycle mean U-Hg concentrations > 38.7 < 53.5 μg/L) in interaction with alcohol remain a plausible explanation for the depression associated with negative self-concept found in subgroups of ex-mercury miners. This could be one of the reason for the higher risk of suicide among miners of the Idrija Mercury Mine in the last 45 years. PMID:16451870

Mixed-method research protocol: defining and operationalizing patient-related complexity of nursing care in acute care hospitals.

PubMed

Huber, Evelyn; Kleinknecht-Dolf, Michael; Müller, Marianne; Kugler, Christiane; Spirig, Rebecca

2017-06-01

To define the concept of patient-related complexity of nursing care in acute care hospitals and to operationalize it in a questionnaire. The concept of patient-related complexity of nursing care in acute care hospitals has not been conclusively defined in the literature. The operationalization in a corresponding questionnaire is necessary, given the increased significance of the topic, due to shortened lengths of stay and increased patient morbidity. Hybrid model of concept development and embedded mixed-methods design. The theoretical phase of the hybrid model involved a literature review and the development of a working definition. In the fieldwork phase of 2015 and 2016, an embedded mixed-methods design was applied with complexity assessments of all patients at five Swiss hospitals using our newly operationalized questionnaire 'Complexity of Nursing Care' over 1 month. These data will be analysed with structural equation modelling. Twelve qualitative case studies will be embedded. They will be analysed using a structured process of constructing case studies and content analysis. In the final analytic phase, the quantitative and qualitative data will be merged and added to the results of the theoretical phase for a common interpretation. Cantonal Ethics Committee Zurich judged the research programme as unproblematic in December 2014 and May 2015. Following the phases of the hybrid model and using an embedded mixed-methods design can reach an in-depth understanding of patient-related complexity of nursing care in acute care hospitals, a final version of the questionnaire and an acknowledged definition of the concept. © 2016 John Wiley & Sons Ltd.

Prenatal alcohol exposure and cellular differentiation: a role for Polycomb and Trithorax group proteins in FAS phenotypes?

PubMed

Veazey, Kylee J; Muller, Daria; Golding, Michael C

2013-01-01

Exposure to alcohol significantly alters the developmental trajectory of progenitor cells and fundamentally compromises tissue formation (i.e., histogenesis). Emerging research suggests that ethanol can impair mammalian development by interfering with the execution of molecular programs governing differentiation. For example, ethanol exposure disrupts cellular migration, changes cell-cell interactions, and alters growth factor signaling pathways. Additionally, ethanol can alter epigenetic mechanisms controlling gene expression. Normally, lineage-specific regulatory factors (i.e., transcription factors) establish the transcriptional networks of each new cell type; the cell's identity then is maintained through epigenetic alterations in the way in which the DNA encoding each gene becomes packaged within the chromatin. Ethanol exposure can induce epigenetic changes that do not induce genetic mutations but nonetheless alter the course of fetal development and result in a large array of patterning defects. Two crucial enzyme complexes--the Polycomb and Trithorax proteins--are central to the epigenetic programs controlling the intricate balance between self-renewal and the execution of cellular differentiation, with diametrically opposed functions. Prenatal ethanol exposure may disrupt the functions of these two enzyme complexes, altering a crucial aspect of mammalian differentiation. Characterizing the involvement of Polycomb and Trithorax group complexes in the etiology of fetal alcohol spectrum disorders will undoubtedly enhance understanding of the role that epigenetic programming plays in this complex disorder.

Role of complex organic arsenicals in food in aggregate exposure to arsenic

EPA Science Inventory

For much of the world’s population, food is the major source of exposure to arsenic. Exposure to this non-essential metalloid at relatively low levels has been linked to a wide range of adverse health effects. Thus, evaluating foods as sources of exposure to arsenic is important ...

Categorizing Teacher Behavior: Test Manual.

ERIC Educational Resources Information Center

Pugh, Richard C.; And Others

Categorizing Teacher Behavior, developed to measure acquisition of concepts portrayed in the Concepts and Patterns in Teacher-Pupil Interaction film series, measures the ability to identify and categorize instances of the specificed concepts as they are portrayed in reasonably complex filmed classroom interactions. The film series itself is based…

Assessment of the potential human health risks from exposure to complex substances in accordance with REACH requirements. "White spirit" as a case study.

PubMed

McKee, Richard H; Tibaldi, Rosalie; Adenuga, Moyinoluwa D; Carrillo, Juan-Carlos; Margary, Alison

2018-02-01

The European chemical control regulation (REACH) requires that data on physical/chemical, toxicological and environmental hazards be compiled. Additionally, REACH requires formal assessments to ensure that substances can be safely used for their intended purposes. For health hazard assessments, reference values (Derived No Effect levels, DNELs) are calculated from toxicology data and compared to estimated exposure levels. If the ratio of the predicted exposure level to the DNEL, i.e. the Risk Characterization Ratio (RCR), is less than 1, the risk is considered controlled; otherwise, additional Risk Management Measures (RMM) must be applied. These requirements pose particular challenges for complex substances. Herein, "white spirit", a complex hydrocarbon solvent, is used as an example to illustrate how these procedures were applied. Hydrocarbon solvents were divided into categories of similar substances. Representative substances were identified for DNEL determinations. Adjustment factors were applied to the no effect levels to calculate the DNELs. Exposure assessments utilized a standardized set of generic exposure scenarios (GES) which incorporated exposure predictions for solvent handling activities. Computer-based tools were developed to automate RCR calculations and identify appropriate RMMs, allowing consistent communications to users via safety data sheets. Copyright © 2017 ExxonMobil Biomedical Sciences Inc. Published by Elsevier Inc. All rights reserved.

Bilingual Children's Acquisition of English Verb Morphology: Effects of Language Exposure, Structure Complexity, and Task Type

ERIC Educational Resources Information Center

Paradis, Johanne

2010-01-01

This study investigated whether bilingual-monolingual differences would be apparent in school-age children's use and knowledge of English verb morphology and whether differences would be influenced by amount of exposure to English, complexity of the morphological structure, or the type of task given. French-English bilinguals (mean age = 6;10)…

A DYNAMIC PHYSIOLOGICALLY-BASED TOXICOKINETIC (DPBTK) MODEL FOR SIMULATION OF COMPLEX TOLUENE EXPOSURE SCENARIOS IN HUMANS

EPA Science Inventory

A GENERAL PHYSIOLOGICAL AND TOXICOKINETIC (GPAT) MODEL FOR SIMULATION OF COMPLEX TOLUENE EXPOSURE SCENARIOS IN HUMANS. E M Kenyon1, T Colemen2, C R Eklund1 and V A Benignus3. 1U.S. EPA, ORD, NHEERL, ETD, PKB, RTP, NC, USA; 2Biological Simulators, Inc., Jackson MS, USA, 3U.S. EP...

Developing and applying the adverse outcome pathway concept for understanding and predicting neurotoxicity

PubMed Central

Bal-Price, Anna; Lein, Pamela J.; Keil, Kimberly P.; Sethi, Sunjay; Shafer, Timothy; Barenys, Marta; Fritsche, Ellen; Sachana, Magdalini; Meek, M.E. (Bette)

2016-01-01

The Adverse Outcome Pathway (AOP) concept has recently been proposed to support a paradigm shift in regulatory toxicology testing and risk assessment. This concept is similar to the Mode of Action (MOA), in that it describes a sequence of measurable key events triggered by a molecular initiating event in which a stressor interacts with a biological target. The resulting cascade of key events includes molecular, cellular, structural and functional changes in biological systems, resulting in a measurable adverse outcome. Thereby, an AOP ideally provides information relevant to chemical structure-activity relationships as a basis for predicting effects of structurally similar compounds. AOPs could potentially also form the basis for qualitative and quantitative predictive modeling of the human adverse outcome resulting from molecular initiating or other key events for which higher-throughput testing methods are available or can be developed. A variety of cellular and molecular processes are known to be critical for normal function of the central (CNS) and peripheral nervous systems (PNS). Because of the biological and functional complexity of the CNS and PNS, it has been challenging to establish causative links and quantitative relationships between key events that comprise the pathways leading from chemical exposure to an adverse outcome in the nervous system. Following introduction of the principles of MOA and AOPs, examples of potential or putative adverse outcome pathways specific for developmental or adult neurotoxicity are summarized and aspects of their assessment considered. Their possible application in developing mechanistically informed Integrated Approaches to Testing and Assessment (IATA) is also discussed. PMID:27212452

High fat diet and in utero exposure to maternal obesity disrupts circadian rhythm and leads to metabolic programming of liver in rat offspring

USDA-ARS?s Scientific Manuscript database

The risk of obesity in adulthood is subject to programming beginning at conception. In animal models, exposure to maternal obesity and high fat diets influences the risk of obesity in the offspring. Among other long-term changes, offspring from obese rats develop hyperinsulinemia, hepatic steatosi...

A Systems-Based Conceptual Framework for Assessing the Determinants of a Social License to Operate in the Mining Industry

NASA Astrophysics Data System (ADS)

Prno, Jason; Slocombe, D. Scott

2014-03-01

The concept of a "social license to operate" (SLO) was coined in the 1990s and gained popularity as one way in which "social" considerations can be addressed in mineral development decision making. The need for a SLO implies that developers require the widespread approval of local community members for their projects to avoid exposure to potentially costly conflict and business risks. Only a limited amount of scholarship exists on the topic, and there is a need for research that specifically addresses the complex and changeable nature of SLO outcomes. In response to these challenges, this paper advances a novel, systems-based conceptual framework for assessing SLO determinants and outcomes in the mining industry. Two strands of systems theory are specifically highlighted—complex adaptive systems and resilience—and the roles of context, key system variables, emergence, change, uncertainty, feedbacks, cross-scale effects, multiple stable states, thresholds, and resilience are discussed. The framework was developed from the results of a multi-year research project which involved international mining case study investigations, a comprehensive literature review, and interviews conducted with mining stakeholders and observers. The framework can help guide SLO analysis and management efforts, by encouraging users to account for important contextual and complexity-oriented elements present in SLO settings. We apply the framework to a case study in Alaska, USA before discussing its merits and challenges. We also illustrate knowledge gaps associated with applications of complex adaptive systems and resilience theories to the study of SLO dynamics, and discuss opportunities for future research.

A systems-based conceptual framework for assessing the determinants of a social license to operate in the mining industry.

PubMed

Prno, Jason; Slocombe, D Scott

2014-03-01

The concept of a "social license to operate" (SLO) was coined in the 1990s and gained popularity as one way in which "social" considerations can be addressed in mineral development decision making. The need for a SLO implies that developers require the widespread approval of local community members for their projects to avoid exposure to potentially costly conflict and business risks. Only a limited amount of scholarship exists on the topic, and there is a need for research that specifically addresses the complex and changeable nature of SLO outcomes. In response to these challenges, this paper advances a novel, systems-based conceptual framework for assessing SLO determinants and outcomes in the mining industry. Two strands of systems theory are specifically highlighted-complex adaptive systems and resilience-and the roles of context, key system variables, emergence, change, uncertainty, feedbacks, cross-scale effects, multiple stable states, thresholds, and resilience are discussed. The framework was developed from the results of a multi-year research project which involved international mining case study investigations, a comprehensive literature review, and interviews conducted with mining stakeholders and observers. The framework can help guide SLO analysis and management efforts, by encouraging users to account for important contextual and complexity-oriented elements present in SLO settings. We apply the framework to a case study in Alaska, USA before discussing its merits and challenges. We also illustrate knowledge gaps associated with applications of complex adaptive systems and resilience theories to the study of SLO dynamics, and discuss opportunities for future research.

Analysis of complex-type chromosome exchanges in astronauts' lymphocytes after space flight as a biomarker of high-LET exposure

NASA Technical Reports Server (NTRS)

George, Kerry; Wu, Honglu; Willingham, Veronica; Cucinotta, Francis A.

2002-01-01

High-LET radiation is more efficient in producing complex-type chromosome exchanges than sparsely ionizing radiation, and this can potentially be used as a biomarker of radiation quality. To investigate if complex chromosome exchanges are induced by the high-LET component of space radiation exposure, damage was assessed in astronauts' blood lymphocytes before and after long duration missions of 3-4 months. The frequency of simple translocations increased significantly for most of the crewmembers studied. However, there were few complex exchanges detected and only one crewmember had a significant increase after flight. It has been suggested that the yield of complex chromosome damage could be underestimated when analyzing metaphase cells collected at one time point after irradiation, and analysis of chemically-induced PCC may be more accurate since problems with complicated cell-cycle delays are avoided. However, in this case the yields of chromosome damage were similar for metaphase and PCC analysis of astronauts' lymphocytes. It appears that the use of complex-type exchanges as biomarker of radiation quality in vivo after low-dose chronic exposure in mixed radiation fields is hampered by statistical uncertainties.

Biological markers of intermediate outcomes in studies of indoor air and other complex mixtures.

PubMed Central

Wilcosky, T C

1993-01-01

Biological markers of intermediate health outcomes sometimes provide a superior alternative to traditional measures of pollutant-related disease. Some opportunities and methodologic issues associated with using markers are discussed in the context of exposures to four complex mixtures: environmental tobacco smoke and nitrogen dioxide, acid aerosols and oxidant outdoor pollution, environmental tobacco smoke and radon, and volatile organic compounds. For markers of intermediate health outcomes, the most important property is the positive predictive value for clinical outcomes of interest. Unless the marker has a known relationship with disease, a marker response conveys no information about disease risk. Most markers are nonspecific in that various exposures cause the same marker response. Although nonspecificity can be an asset in studies of complex mixtures, it leads to problems with confounding and dilution of exposure-response associations in the presence of other exposures. The timing of a marker's measurement in relation to the occurrence of exposure influences the ability to detect a response; measurements made too early or too late may underestimate the response's magnitude. Noninvasive markers, such as those measured in urine, blood, or nasal lavage fluid, are generally more useful for field studies than are invasive markers. However, invasive markers, such as those measured in bronchoalveolar lavage fluid or lung specimens from autopsies, provide the most direct evidence of pulmonary damage from exposure to air pollutants. Unfortunately, the lack of basic information about marker properties (e.g., sensitivity, variability, statistical link with disease) currently precludes the effective use of most markers in studies of complex mixtures. PMID:8206030

Computer simulation of functioning of elements of security systems

NASA Astrophysics Data System (ADS)

Godovykh, A. V.; Stepanov, B. P.; Sheveleva, A. A.

2017-01-01

The article is devoted to issues of development of the informational complex for simulation of functioning of the security system elements. The complex is described from the point of view of main objectives, a design concept and an interrelation of main elements. The proposed conception of the computer simulation provides an opportunity to simulate processes of security system work for training security staff during normal and emergency operation.

Hierarchical ferroelectric and ferrotoroidic polarizations coexistent in nano-metamaterials

PubMed Central

Shimada, Takahiro; Lich, Le Van; Nagano, Koyo; Wang, Jie; Kitamura, Takayuki

2015-01-01

Tailoring materials to obtain unique, or significantly enhanced material properties through rationally designed structures rather than chemical constituents is principle of metamaterial concept, which leads to the realization of remarkable optical and mechanical properties. Inspired by the recent progress in electromagnetic and mechanical metamaterials, here we introduce the concept of ferroelectric nano-metamaterials, and demonstrate through an experiment in silico with hierarchical nanostructures of ferroelectrics using sophisticated real-space phase-field techniques. This new concept enables variety of unusual and complex yet controllable domain patterns to be achieved, where the coexistence between hierarchical ferroelectric and ferrotoroidic polarizations establishes a new benchmark for exploration of complexity in spontaneous polarization ordering. The concept opens a novel route to effectively tailor domain configurations through the control of internal structure, facilitating access to stabilization and control of complex domain patterns that provide high potential for novel functionalities. A key design parameter to achieve such complex patterns is explored based on the parity of junctions that connect constituent nanostructures. We further highlight the variety of additional functionalities that are potentially obtained from ferroelectric nano-metamaterials, and provide promising perspectives for novel multifunctional devices. This study proposes an entirely new discipline of ferroelectric nano-metamaterials, further driving advances in metamaterials research. PMID:26424484

An Approach for Autonomy: A Collaborative Communication Framework for Multi-Agent Systems

NASA Technical Reports Server (NTRS)

Dufrene, Warren Russell, Jr.

2005-01-01

Research done during the last three years has studied the emersion properties of Complex Adaptive Systems (CAS). The deployment of Artificial Intelligence (AI) techniques applied to remote Unmanned Aerial Vehicles has led the author to investigate applications of CAS within the field of Autonomous Multi-Agent Systems. The core objective of current research efforts is focused on the simplicity of Intelligent Agents (IA) and the modeling of these agents within complex systems. This research effort looks at the communication, interaction, and adaptability of multi-agents as applied to complex systems control. The embodiment concept applied to robotics has application possibilities within multi-agent frameworks. A new framework for agent awareness within a virtual 3D world concept is possible where the vehicle is composed of collaborative agents. This approach has many possibilities for applications to complex systems. This paper describes the development of an approach to apply this virtual framework to the NASA Goddard Space Flight Center (GSFC) tetrahedron structure developed under the Autonomous Nano Technology Swarm (ANTS) program and the Super Miniaturized Addressable Reconfigurable Technology (SMART) architecture program. These projects represent an innovative set of novel concepts deploying adaptable, self-organizing structures composed of many tetrahedrons. This technology is pushing current applied Agents Concepts to new levels of requirements and adaptability.

Evaluation of human exposure to complex waveform magnetic fields generated by arc-welding equipment according to European safety standards.

PubMed

Zoppetti, Nicola; Bogi, Andrea; Pinto, Iole; Andreuccetti, Daniele

2015-02-01

In this paper, a procedure is described for the assessment of human exposure to magnetic fields with complex waveforms generated by arc-welding equipment. The work moves from the analysis of relevant guidelines and technical standards, underlining their strengths and their limits. Then, the procedure is described with particular attention to the techniques used to treat complex waveform fields. Finally, the procedure is applied to concrete cases encountered in the workplace. The discussion of the results highlights the critical points in the procedure, as well as those related to the evolution of the technical and exposure standards. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Enrollment Management: An Introduction to Concepts and Structures

ERIC Educational Resources Information Center

Bontrager, Bob

2004-01-01

In the increasingly complex world of managing enrollments, success or failure hinges on building a solid foundation of concepts, structures, and strategies. This first of a two-part series reviews the core concepts and structural considerations that underlie successful enrollment management organizations. The purpose of this article is to…

An Empirical Exploration of Metacognitive Assessment Activities in a Third-Year Civil Engineering Hydraulics Course

ERIC Educational Resources Information Center

Meyer, Jan H. F.; Knight, David B.; Callaghan, David P.; Baldock, Tom E.

2015-01-01

Threshold concepts are transformative, integrative, and provocative; understanding these difficult concepts allows students to be capable of solving advanced problems. This investigation and evaluation of a metacognitive curricular approach explore variation in students' and teachers' discernment of structural complexity of concepts and its…

Opening the World of Mathematics: The Daily Math Discussion

ERIC Educational Resources Information Center

Donoahue, Zoe

2016-01-01

During the author's everyday math discussions with her class, young children talk about mathematical ideas, theories, and concepts within a predictable structure. These discussions include many concepts from--and beyond--the first-grade math curriculum, and their depth and complexity build throughout the school year. Concepts and skills include…

Harnessing Technology to Improve Formative Assessment of Student Conceptions in STEM: Forging a National Network

ERIC Educational Resources Information Center

Haudek, Kevin C.; Kaplan, Jennifer J.; Knight, Jennifer; Long, Tammy; Merrill, John; Munn, Alan; Nehm, Ross; Smith, Michelle; Urban-Lurain, Mark

2011-01-01

Concept inventories, consisting of multiple-choice questions designed around common student misconceptions, are designed to reveal student thinking. However, students often have complex, heterogeneous ideas about scientific concepts. Constructed-response assessments, in which students must create their own answer, may better reveal students'…

Developing Conceptions of Authority and Contract across the Lifespan: Two Perspectives.

ERIC Educational Resources Information Center

Dawson, Theo L.; Gabrielian, Sonya

2003-01-01

Compares concepts defining Kohlbergian stages of moral development with those associated with orders of hierarchical complexity determined with a generalized content-independent stage-scoring system. Finds that Kohlberg's sequence generally matches that identified with the scoring system and that contract and authority concepts match the concepts…

Children's Naive Concepts of OCD and How They Are Affected by Biomedical Versus Cognitive Behavioural Psychoeducation.

PubMed

Butlin, B; Wilson, C

2018-04-04

How we conceptualize mental health conditions is important as it impacts on a wide range of mediators of treatment outcome. We do not know how children intuitively conceptualize obsessive-compulsive disorder (OCD), nor do we know the relative impact of biomedical or cognitive behavioural conceptual explanations, yet both are being widely used in psychoeducation for children with OCD. This study identified children's naive concepts of OCD, and the comparative impact of biomedical versus cognitive behavioural psychoeducation on perceived prognosis. A within- and between-subjects experimental design was used. After watching a video of a young person describing their OCD, 202 children completed a questionnaire examining their concepts of the condition. They repeated the questionnaire following a second equivalent video, this time preceded by either biomedical or cognitive behavioural psychoeducation. Participants' naive concepts of OCD reflected predominant models of OCD in healthcare. Even at the minimal dose of psychoeducation, participants' conceptualizations of OCD changed. Prior exposure to OCD resulted in a stronger alignment with the biomedical model. Exposure to biomedical psychoeducation resulted in participants predicting a slower recovery with less chance of complete remission. Psychoeducation for childhood OCD is impactful. Despite its wide use by clinicians and mental health services, biomedical psychoeducation appears to have deleterious effects. Children's concepts of OCD merit attention but caution should be applied in how they are targeted.

Problem formulation for risk assessment of combined exposures to chemicals and other stressors in humans.

PubMed

Solomon, Keith R; Wilks, Martin F; Bachman, Ammie; Boobis, Alan; Moretto, Angelo; Pastoor, Timothy P; Phillips, Richard; Embry, Michelle R

2016-11-01

When the human health risk assessment/risk management paradigm was developed, it did not explicitly include a "problem formulation" phase. The concept of problem formulation was first introduced in the context of ecological risk assessment (ERA) for the pragmatic reason to constrain and focus ERAs on the key questions. However, this need also exists for human health risk assessment, particularly for cumulative risk assessment (CRA), because of its complexity. CRA encompasses the combined threats to health from exposure via all relevant routes to multiple stressors, including biological, chemical, physical and psychosocial stressors. As part of the HESI Risk Assessment in the 21st Century (RISK21) Project, a framework for CRA was developed in which problem formulation plays a critical role. The focus of this effort is primarily on a chemical CRA (i.e., two or more chemicals) with subsequent consideration of non-chemical stressors, defined as "modulating factors" (ModFs). Problem formulation is a systematic approach that identifies all factors critical to a specific risk assessment and considers the purpose of the assessment, scope and depth of the necessary analysis, analytical approach, available resources and outcomes, and overall risk management goal. There are numerous considerations that are specific to multiple stressors, and proper problem formulation can help to focus a CRA to the key factors in order to optimize resources. As part of the problem formulation, conceptual models for exposures and responses can be developed that address these factors, such as temporal relationships between stressors and consideration of the appropriate ModFs.

Assessing, mapping and validating site-specific ecotoxicological risk for pesticide mixtures: a case study for small scale hot spots in aquatic and terrestrial environments.

PubMed

Vaj, Claudia; Barmaz, Stefania; Sørensen, Peter Borgen; Spurgeon, David; Vighi, Marco

2011-11-01

Mixture toxicity is a real world problem and as such requires risk assessment solutions that can be applied within different geographic regions, across different spatial scales and in situations where the quantity of data available for the assessment varies. Moreover, the need for site specific procedures for assessing ecotoxicological risk for non-target species in non-target ecosystems also has to be recognised. The work presented in the paper addresses the real world effects of pesticide mixtures on natural communities. Initially, the location of risk hotspots is theoretically estimated through exposure modelling and the use of available toxicity data to predict potential community effects. The concept of Concentration Addition (CA) is applied to describe responses resulting from exposure of multiple pesticides The developed and refined exposure models are georeferenced (GIS-based) and include environmental and physico-chemical parameters, and site specific information on pesticide usage and land use. As a test of the risk assessment framework, the procedures have been applied on a suitable study areas, notably the River Meolo basin (Northern Italy), a catchment characterised by intensive agriculture, as well as comparative area for some assessments. Within the studied areas, the risks for individual chemicals and complex mixtures have been assessed on aquatic and terrestrial aboveground and belowground communities. Results from ecological surveys have been used to validate these risk assessment model predictions. Value and limitation of the approaches are described and the possibilities for larger scale applications in risk assessment are also discussed. Copyright © 2011 Elsevier Inc. All rights reserved.

Revolutionary Concepts of Radiation Shielding for Human Exploration of Space

NASA Technical Reports Server (NTRS)

Adams, J. H., Jr.; Hathaway, D. H.; Grugel, R. N.; Watts, J. W.; Parnell, T. A.; Gregory, J. C.; Winglee, R. M.

2005-01-01

This Technical Memorandum covers revolutionary ideas for space radiation shielding that would mitigate mission costs while limiting human exposure, as studied in a workshop held at Marshall Space Flight Center at the request of NASA Headquarters. None of the revolutionary new ideas examined for the .rst time in this workshop showed clear promise. The workshop attendees felt that some previously examined concepts were de.nitely useful and should be pursued. The workshop attendees also concluded that several of the new concepts warranted further investigation to clarify their value.

Stereotaxy, navigation and the temporal concatenation.

PubMed

Apuzzo, M L; Chen, J C

1999-01-01

Nautical and cerebral navigation share similar elements of functional need and similar developmental pathways. The need for orientation necessitates the development of appropriate concepts, and such concepts are dependent on technology for practical realization. Occasionally, a concept precedes technology in time and requires periods of delay for appropriate development. A temporal concatenation exists where time allows the additive as need, concept and technology ultimately provide an endpoint of elegant solution. Nautical navigation has proceeded through periods of dead reckoning and celestial navigation to satellite orientation with associated refinements of instrumentation and charts for guidance. Cerebral navigation has progressed from craniometric orientation and burr hole mounted guidance systems to simple rectolinear and arc-centered devices based on radiographs to guidance by complex anatomical and functional maps provided as an amalgam of modern imaging modes. These maps are now augmented by complex frame and frameless systems which allow not only precise orientation, but also point and volumetric action. These complex technical modalities required and developed in part from elements of maritime navigation that have been translated to cerebral navigation in a temporal concatenation. Copyright 2000 S. Karger AG, Basel

A model-based design and validation approach with OMEGA-UML and the IF toolset

NASA Astrophysics Data System (ADS)

Ben-hafaiedh, Imene; Constant, Olivier; Graf, Susanne; Robbana, Riadh

2009-03-01

Intelligent, embedded systems such as autonomous robots and other industrial systems are becoming increasingly more heterogeneous with respect to the platforms on which they are implemented, and thus the software architecture more complex to design and analyse. In this context, it is important to have well-defined design methodologies which should be supported by (1) high level design concepts allowing to master the design complexity, (2) concepts for the expression of non-functional requirements and (3) analysis tools allowing to verify or invalidate that the system under development will be able to conform to its requirements. We illustrate here such an approach for the design of complex embedded systems on hand of a small case study used as a running example for illustration purposes. We briefly present the important concepts of the OMEGA-RT UML profile, we show how we use this profile in a modelling approach, and explain how these concepts are used in the IFx verification toolbox to integrate validation into the design flow and make scalable verification possible.

DEVELOPMENT OF CHEMICAL METHODS TO CHARACTERIZE EXPOSURE TO EDCS IN THE NEUSE RIVER BASIN

EPA Science Inventory

To develop a quantitative health and environmental risk assessment of endocrine disrupting compounds (EDCs), information on exposures is essential. A full exposure assessment has complex requirements that require preliminary information to direct further research in this area....

ISSUES AND CHALLENGES IN MODELING CHILDREN'S LONGITUDINAL EXPOSURES: AN OZONE STUDY

EPA Science Inventory

Modeling children's exposures is a complicated, data-intensive process. Modeling longitudinal exposures, which are important for regulatory decision making, especially for most air toxics, adds another level of complexity and data requirements. Because it is difficult to model in...

Maximizing information exchange between complex networks

NASA Astrophysics Data System (ADS)

West, Bruce J.; Geneston, Elvis L.; Grigolini, Paolo

2008-10-01

Science is not merely the smooth progressive interaction of hypothesis, experiment and theory, although it sometimes has that form. More realistically the scientific study of any given complex phenomenon generates a number of explanations, from a variety of perspectives, that eventually requires synthesis to achieve a deep level of insight and understanding. One such synthesis has created the field of out-of-equilibrium statistical physics as applied to the understanding of complex dynamic networks. Over the past forty years the concept of complexity has undergone a metamorphosis. Complexity was originally seen as a consequence of memory in individual particle trajectories, in full agreement with a Hamiltonian picture of microscopic dynamics and, in principle, macroscopic dynamics could be derived from the microscopic Hamiltonian picture. The main difficulty in deriving macroscopic dynamics from microscopic dynamics is the need to take into account the actions of a very large number of components. The existence of events such as abrupt jumps, considered by the conventional continuous time random walk approach to describing complexity was never perceived as conflicting with the Hamiltonian view. Herein we review many of the reasons why this traditional Hamiltonian view of complexity is unsatisfactory. We show that as a result of technological advances, which make the observation of single elementary events possible, the definition of complexity has shifted from the conventional memory concept towards the action of non-Poisson renewal events. We show that the observation of crucial processes, such as the intermittent fluorescence of blinking quantum dots as well as the brain’s response to music, as monitored by a set of electrodes attached to the scalp, has forced investigators to go beyond the traditional concept of complexity and to establish closer contact with the nascent field of complex networks. Complex networks form one of the most challenging areas of modern research overarching all of the traditional scientific disciplines. The transportation networks of planes, highways and railroads; the economic networks of global finance and stock markets; the social networks of terrorism, governments, businesses and churches; the physical networks of telephones, the Internet, earthquakes and global warming and the biological networks of gene regulation, the human body, clusters of neurons and food webs, share a number of apparently universal properties as the networks become increasingly complex. Ubiquitous aspects of such complex networks are the appearance of non-stationary and non-ergodic statistical processes and inverse power-law statistical distributions. Herein we review the traditional dynamical and phase-space methods for modeling such networks as their complexity increases and focus on the limitations of these procedures in explaining complex networks. Of course we will not be able to review the entire nascent field of network science, so we limit ourselves to a review of how certain complexity barriers have been surmounted using newly applied theoretical concepts such as aging, renewal, non-ergodic statistics and the fractional calculus. One emphasis of this review is information transport between complex networks, which requires a fundamental change in perception that we express as a transition from the familiar stochastic resonance to the new concept of complexity matching.

Attempt to generalize fractional-order electric elements to complex-order ones

NASA Astrophysics Data System (ADS)

Si, Gangquan; Diao, Lijie; Zhu, Jianwei; Lei, Yuhang; Zhang, Yanbin

2017-06-01

The complex derivative {D}α +/- {{j}β }, with α, β \\in R+ is a generalization of the concept of integer derivative, where α=1, β=0. Fractional-order electric elements and circuits are becoming more and more attractive. In this paper, the complex-order electric elements concept is proposed for the first time, and the complex-order elements are modeled and analyzed. Some interesting phenomena are found that the real part of the order affects the phase of output signal, and the imaginary part affects the amplitude for both the complex-order capacitor and complex-order memristor. More interesting is that the complex-order capacitor can do well at the time of fitting electrochemistry impedance spectra. The complex-order memristor is also analyzed. The area inside the hysteresis loops increases with the increasing of the imaginary part of the order and decreases with the increasing of the real part. Some complex case of complex-order memristors hysteresis loops are analyzed at last, whose loop has touching points beyond the origin of the coordinate system.

Direct-Write Printing on Three-Dimensional Geometries for Miniaturized Detector and Electronic Assemblies

NASA Technical Reports Server (NTRS)

Paquette, Beth; Samuels, Margaret; Chen, Peng

2017-01-01

Direct-write printing techniques will enable new detector assemblies that were not previously possible with traditional assembly processes. Detector concepts were manufactured using this technology to validate repeatability. Additional detector applications and printed wires on a 3-dimensional magnetometer bobbin will be designed for print. This effort focuses on evaluating performance for direct-write manufacturing techniques on 3-dimensional surfaces. Direct-write manufacturing has the potential to reduce mass and volume for fabrication and assembly of advanced detector concepts by reducing trace widths down to 10 microns, printing on complex geometries, allowing new electronic concept production, and reduced production times of complex those electronics.

Space Station Simulation Computer System (SCS) study for NASA/MSFC. Concept document

NASA Technical Reports Server (NTRS)

1990-01-01

NASA's Space Station Freedom Program (SSFP) planning efforts have identified a need for a payload training simulator system to serve as both a training facility and as a demonstrator to validate operational concepts. The envisioned MSFC Payload Training Complex (PTC) required to meet this need will train the Space Station Payload of experiments that will be onboard the Space Station Freedom. The simulation will support the Payload Training Complex at MSFC. The purpose of this SCS Study is to investigate issues related to the SCS, alternative requirements, simulator approaches, and state-of-the-art technologies to develop candidate concepts and designs.

CFD-RANS prediction of individual exposure from continuous release of hazardous airborne materials in complex urban environments

NASA Astrophysics Data System (ADS)

Efthimiou, G. C.; Andronopoulos, S.; Bartzis, J. G.; Berbekar, E.; Harms, F.; Leitl, B.

2017-02-01

One of the key issues of recent research on the dispersion inside complex urban environments is the ability to predict individual exposure (maximum dosages) of an airborne material which is released continuously from a point source. The present work addresses the question whether the computational fluid dynamics (CFD)-Reynolds-averaged Navier-Stokes (RANS) methodology can be used to predict individual exposure for various exposure times. This is feasible by providing the two RANS concentration moments (mean and variance) and a turbulent time scale to a deterministic model. The whole effort is focused on the prediction of individual exposure inside a complex real urban area. The capabilities of the proposed methodology are validated against wind-tunnel data (CUTE experiment). The present simulations were performed 'blindly', i.e. the modeller had limited information for the inlet boundary conditions and the results were kept unknown until the end of the COST Action ES1006. Thus, a high uncertainty of the results was expected. The general performance of the methodology due to this 'blind' strategy is good. The validation metrics fulfil the acceptance criteria. The effect of the grid and the turbulence model on the model performance is examined.

Conceptual Foundations of Systems Biology Explaining Complex Cardiac Diseases.

PubMed

Louridas, George E; Lourida, Katerina G

2017-02-21

Systems biology is an important concept that connects molecular biology and genomics with computing science, mathematics and engineering. An endeavor is made in this paper to associate basic conceptual ideas of systems biology with clinical medicine. Complex cardiac diseases are clinical phenotypes generated by integration of genetic, molecular and environmental factors. Basic concepts of systems biology like network construction, modular thinking, biological constraints (downward biological direction) and emergence (upward biological direction) could be applied to clinical medicine. Especially, in the field of cardiology, these concepts can be used to explain complex clinical cardiac phenotypes like chronic heart failure and coronary artery disease. Cardiac diseases are biological complex entities which like other biological phenomena can be explained by a systems biology approach. The above powerful biological tools of systems biology can explain robustness growth and stability during disease process from modulation to phenotype. The purpose of the present review paper is to implement systems biology strategy and incorporate some conceptual issues raised by this approach into the clinical field of complex cardiac diseases. Cardiac disease process and progression can be addressed by the holistic realistic approach of systems biology in order to define in better terms earlier diagnosis and more effective therapy.

Prospects of application of additive technologies for increasing the efficiency of impeller machines

NASA Astrophysics Data System (ADS)

Belova, O. V.; Borisov, Yu. A.

2017-08-01

Impeller machine is a device in which the flow path carries out the supply (or retraction) of mechanical energy to the flow of a working fluid passing through the machine. To increase the efficiency of impeller machines, it is necessary to use design modern technologies, namely the use of numerical methods for conducting research in the field of gas dynamics, as well as additive manufacturing (AM) for the of both prototypes and production model. AM technologies are deservedly rightly called revolutionary because they give unique possibility for manufacturing products, creating perfect forms, both light and durable. The designers face the challenge of developing a new design methodology, since AM allows the use of the concept of "Complexity For Free". The "Complexity For Free" conception is based on: complexity of the form; hierarchical complexity; complexity of the material; functional complexity. The new technical items design method according to a functional principle is also investigated.

Loss of 'complexity' and aging. Potential applications of fractals and chaos theory to senescence

NASA Technical Reports Server (NTRS)

Lipsitz, L. A.; Goldberger, A. L.

1992-01-01

The concept of "complexity," derived from the field of nonlinear dynamics, can be adapted to measure the output of physiologic processes that generate highly variable fluctuations resembling "chaos." We review data suggesting that physiologic aging is associated with a generalized loss of such complexity in the dynamics of healthy organ system function and hypothesize that such loss of complexity leads to an impaired ability to adapt to physiologic stress. This hypothesis is supported by observations showing an age-related loss of complex variability in multiple physiologic processes including cardiovascular control, pulsatile hormone release, and electroencephalographic potentials. If further research supports this hypothesis, measures of complexity based on chaos theory and the related geometric concept of fractals may provide new ways to monitor senescence and test the efficacy of specific interventions to modify the age-related decline in adaptive capacity.

Health and reproductive outcomes among American legionnaires in relation to combat and herbicide exposure in Vietnam

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

Stellman, S.D.; Stellman, J.M.; Sommer, J.F. Jr.

1988-12-01

History of diagnosed illnesses, medical symptoms, and reproductive outcomes and their relation to combat intensity and herbicide exposure were studied, via a mailed questionnaire, among 6,810 American Legionnaires who served during the Vietnam War (42% in Southeast Asia, 58% elsewhere). Heart disease, venereal disease, and benign fatty tumors were reported significantly more often by Vietnam veterans than by controls. Combat intensity was significantly dosage-related to history of high blood pressure, ulcers, arthritis and rheumatism, genito-urinary problems, nervous system disease, major injury, hepatitis, and benign fatty tumors. Agent Orange exposure was significantly dosage-related to history of benign fatty tumors, adult acne,more » skin rash with blisters, and increased sensitivity of eyes to light. Rates of the latter two conditions and of change in skin color were especially elevated in men whose military occupations involved direct handling of herbicides. Neither combat nor Agent Orange exposure was associated with difficulty in conception, time to conception of first child, or to birthweight or sex ratio of offspring, but maternal smoking was strongly related to reduced birthweight. The percentage of spouses' pregnancies which resulted in miscarriages was significantly higher for Vietnam veterans than controls. Logistic regression analysis showed that Agent Orange exposure and maternal smoking were both independently and significantly associated with miscarriage rates in a dose-related manner.« less

A generic multi-hazard and multi-risk framework and its application illustrated in a virtual city

NASA Astrophysics Data System (ADS)

Mignan, Arnaud; Euchner, Fabian; Wiemer, Stefan

2013-04-01

We present a generic framework to implement hazard correlations in multi-risk assessment strategies. We consider hazard interactions (process I), time-dependent vulnerability (process II) and time-dependent exposure (process III). Our approach is based on the Monte Carlo method to simulate a complex system, which is defined from assets exposed to a hazardous region. We generate 1-year time series, sampling from a stochastic set of events. Each time series corresponds to one risk scenario and the analysis of multiple time series allows for the probabilistic assessment of losses and for the recognition of more or less probable risk paths. Each sampled event is associated to a time of occurrence, a damage footprint and a loss footprint. The occurrence of an event depends on its rate, which is conditional on the occurrence of past events (process I, concept of correlation matrix). Damage depends on the hazard intensity and on the vulnerability of the asset, which is conditional on previous damage on that asset (process II). Losses are the product of damage and exposure value, this value being the original exposure minus previous losses (process III, no reconstruction considered). The Monte Carlo method allows for a straightforward implementation of uncertainties and for implementation of numerous interactions, which is otherwise challenging in an analytical multi-risk approach. We apply our framework to a synthetic data set, defined by a virtual city within a virtual region. This approach gives the opportunity to perform multi-risk analyses in a controlled environment while not requiring real data, which may be difficultly accessible or simply unavailable to the public. Based on the heuristic approach, we define a 100 by 100 km region where earthquakes, volcanic eruptions, fluvial floods, hurricanes and coastal floods can occur. All hazards are harmonized to a common format. We define a 20 by 20 km city, composed of 50,000 identical buildings with a fixed economic value. Vulnerability curves are defined in terms of mean damage ratio as a function of hazard intensity. All data are based on simple equations found in the literature and on other simplifications. We show the impact of earthquake-earthquake interaction and hurricane-storm surge coupling, as well as of time-dependent vulnerability and exposure, on aggregated loss curves. One main result is the emergence of low probability-high consequences (extreme) events when correlations are implemented. While the concept of virtual city can suggest the theoretical benefits of multi-risk assessment for decision support, identifying their real-world practicality will require the study of real test sites.

Metabolomics Tools for Describing Complex Pesticide Exposure in Pregnant Women in Brittany (France)

PubMed Central

Bonvallot, Nathalie; Tremblay-Franco, Marie; Chevrier, Cécile; Canlet, Cécile; Warembourg, Charline; Cravedi, Jean-Pierre; Cordier, Sylvaine

2013-01-01

Background The use of pesticides and the related environmental contaminations can lead to human exposure to various molecules. In early-life, such exposures could be responsible for adverse developmental effects. However, human health risks associated with exposure to complex mixtures are currently under-explored. Objective This project aims at answering the following questions: What is the influence of exposures to multiple pesticides on the metabolome? What mechanistic pathways could be involved in the metabolic changes observed? Methods Based on the PELAGIE cohort (Brittany, France), 83 pregnant women who provided a urine sample in early pregnancy, were classified in 3 groups according to the surface of land dedicated to agricultural cereal activities in their town of residence. Nuclear magnetic resonance-based metabolomics analyses were performed on urine samples. Partial Least Squares Regression-Discriminant Analysis (PLS-DA) and polytomous regressions were used to separate the urinary metabolic profiles from the 3 exposure groups after adjusting for potential confounders. Results The 3 groups of exposure were correctly separated with a PLS-DA model after implementing an orthogonal signal correction with pareto standardizations (R2 = 90.7% and Q2 = 0.53). After adjusting for maternal age, parity, body mass index and smoking habits, the most statistically significant changes were observed for glycine, threonine, lactate and glycerophosphocholine (upward trend), and for citrate (downward trend). Conclusion This work suggests that an exposure to complex pesticide mixtures induces modifications of metabolic fingerprints. It can be hypothesized from identified discriminating metabolites that the pesticide mixtures could increase oxidative stress and disturb energy metabolism. PMID:23704985

Activity of amikacin against Mycobacterium avium complex under simulated in vivo conditions.

PubMed Central

Gangadharam, P R; Kesavalu, L; Rao, P N; Perumal, V K; Iseman, M D

1988-01-01

We studied the activity of amikacin against Mycobacterium avium complex strain 101 by using continuous-level, changing concentrations which simulated levels in serum in a patient, and pulsed exposures. Amikacin at a concentration of 5 or 15 micrograms/ml showed rapid bactericidal action following constant exposure of the organisms. With the in vitro model, using a peak concentration of 10 or 20 micrograms/ml, complete sterilization was obtained by day 7. In pulsed-exposure studies, a minimum period of contact of 72 or 96 h at a concentration of 10 micrograms/ml was needed for complete sterilization. PMID:3415209

Interpretation of biomonitoring data in clinical medicine and the exposure sciences

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

Williams, Bryan L.; Barr, Dana B.; Wright, J. Michael

2008-11-15

Biomonitoring has become a fundamental tool in both exposure science and clinical medicine. Despite significant analytical advances, the clinical use of environmental biomarkers remains in its infancy. Clinical use of environmental biomarkers poses some complex scientific and ethical challenges. The purpose of this paper is compare how the clinical and exposure sciences differ with respect to their interpretation and use of biological data. Additionally, the clinical use of environmental biomonitoring data is discussed. A case study is used to illustrate the complexities of conducting biomonitoring research on highly vulnerable populations in a clinical setting.

Property-Based Software Engineering Measurement

NASA Technical Reports Server (NTRS)

Briand, Lionel; Morasca, Sandro; Basili, Victor R.

1995-01-01

Little theory exists in the field of software system measurement. Concepts such as complexity, coupling, cohesion or even size are very often subject to interpretation and appear to have inconsistent definitions in the literature. As a consequence, there is little guidance provided to the analyst attempting to define proper measures for specific problems. Many controversies in the literature are simply misunderstandings and stem from the fact that some people talk about different measurement concepts under the same label (complexity is the most common case). There is a need to define unambiguously the most important measurement concepts used in the measurement of software products. One way of doing so is to define precisely what mathematical properties characterize these concepts regardless of the specific software artifacts to which these concepts are applied. Such a mathematical framework could generate a consensus in the software engineering community and provide a means for better communication among researchers, better guidelines for analysis, and better evaluation methods for commercial static analyzers for practitioners. In this paper, we propose a mathematical framework which is generic, because it is not specific to any particular software artifact, and rigorous, because it is based on precise mathematical concepts. This framework defines several important measurement concepts (size, length, complexity, cohesion, coupling). It is not intended to be complete or fully objective; other frameworks could have been proposed and different choices could have been made. However, we believe that the formalism and properties we introduce are convenient and intuitive. In addition, we have reviewed the literature on this subject and compared it with our work. This framework contributes constructively to a firmer theoretical ground of software measurement.

Property-Based Software Engineering Measurement

NASA Technical Reports Server (NTRS)

Briand, Lionel C.; Morasca, Sandro; Basili, Victor R.

1997-01-01

Little theory exists in the field of software system measurement. Concepts such as complexity, coupling, cohesion or even size are very often subject to interpretation and appear to have inconsistent definitions in the literature. As a consequence, there is little guidance provided to the analyst attempting to define proper measures for specific problems. Many controversies in the literature are simply misunderstandings and stem from the fact that some people talk about different measurement concepts under the same label (complexity is the most common case). There is a need to define unambiguously the most important measurement concepts used in the measurement of software products. One way of doing so is to define precisely what mathematical properties characterize these concepts, regardless of the specific software artifacts to which these concepts are applied. Such a mathematical framework could generate a consensus in the software engineering community and provide a means for better communication among researchers, better guidelines for analysts, and better evaluation methods for commercial static analyzers for practitioners. In this paper, we propose a mathematical framework which is generic, because it is not specific to any particular software artifact and rigorous, because it is based on precise mathematical concepts. We use this framework to propose definitions of several important measurement concepts (size, length, complexity, cohesion, coupling). It does not intend to be complete or fully objective; other frameworks could have been proposed and different choices could have been made. However, we believe that the formalisms and properties we introduce are convenient and intuitive. This framework contributes constructively to a firmer theoretical ground of software measurement.

Risk equivalent of exposure versus dose of radiation

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

Bond, V.P.

This report describes a risk analysis study of low-dose irradiation and the resulting biological effects on a cell. The author describes fundamental differences between the effects of high-level exposure (HLE) and low-level exposure (LLE). He stresses that the concept of absorbed dose to an organ is not a dose but a level of effect produced by a particular number of particles. He discusses the confusion between a linear-proportional representation of dose limits and a threshold-curvilinear representation, suggesting that a LLE is a composite of both systems. (TEM)

Toxicity of cobalt-complexed cyanide to Oncorhynchus mykiss, Daphnia magna, and Ceriodaphnia dubia: Potentiation by ultraviolet radiation and attenuation by dissolved organic carbon and adaptive UV tolerance

USGS Publications Warehouse

Little, Edward E.; Calfee, Robin D.; Theodorakos, Peter M.; Brown, Zoe Ann; Johnson, Craig A.

2007-01-01

BackgroundCobalt cyanide complexes often result when ore is treated with cyanide solutions to extract gold and other metals. These have recently been discovered in low but significant concentrations in effluents from gold leach operations. This study was conducted to determine the potential toxicity of cobalt-cyanide complexes to freshwater organisms and the extent to which ultraviolet radiation (UV) potentiates this toxicity. Tests were also conducted to determine if humic acids or if adaptation to UV influenced sensitivity to the cyanide complexes.MethodsRainbow trout (Oncorhynchus mykiss), Daphnia magna, and Ceriodaphnia dubia were exposed to potassium hexacyanocobaltate in the presence and absence of UV radiation, in the presence and absence of humic acids. Cyano-cobalt exposures were also conducted with C. dubia from cultures adapted to elevated UV.ResultsWith an LC50 concentration of 0.38 mg/L, cyanocobalt was over a 1000 times more toxic to rainbow trout in the presence of UV at a low, environmentally relevant irradiance level (4 μW/cm2 as UVB) than exposure to this compound in the absence of UV with an LC50 of 112.9 mg/L. Toxicity was immediately apparent, with mortality occurring within an hour of the onset of exposure at the highest concentration. Fish were unaffected by exposure to UV alone. Weak-acid dissociable cyanide concentrations were observed in irradiated aqueous solutions of cyanocobaltate within hours of UV exposure and persisted in the presence of UV for at least 96 hours, whereas negligible concentrations were observed in the absence of UV. The presence of humic acids significantly diminished cyanocobalt toxicity to D. magna and reduced mortality from UV exposure. Humic acids did not significantly influence survival among C. dubia. C. dubia from UV-adapted populations were less sensitive to metallocyanide compounds than organisms from unadapted populations.ConclusionsThe results indicate that metallocyanide complexes may pose a hazard to aquatic life through photochemically induced processes. Factors that decrease UV exposure such as dissolved organic carbon or increased pigmentation would diminish toxicity.

The biological effect of asbestos exposure is dependent on ...

EPA Pesticide Factsheets

Abstract Functional groups on the surface of fibrous silicates can complex iron. We tested the postulate that 1) asbestos complexes and sequesters host cell iron resulting in a disruption of metal homeostasis and 2) this loss of essential metal results in an oxidative stress and biological effect in respiratory epithelial cells. Exposure of BEAS-2B cells to 50 μg/mL chrysotile resulted in diminished concentrations of mitochondrial iron. Pre-incubation of these cells with 200 μM ferric ammonium citrate (FAC) prevented significant mitochondrial iron loss following the same exposure. The host response to chrysotile included increased expression of the importer divalent metal transporter-1 (DMT1) supporting a functional iron deficiency. Incubation of BEAS-2B cells with both 200 μM FAC and 50 μg/mL chrysotile was associated with a greater cell accumulation of iron relative to either iron or chrysotile alone reflecting increased import to correct metal deficiency immediately following fiber exposure. Cellular oxidant generation was elevated after chrysotile exposure and this signal was diminished by co-incubation with 200 μM FAC. Similarly, exposure of BEAS-2B cells to 50 µg/mL chrysotile was associated with release of the pro-inflammatory mediators interleukin (IL)-6 and IL-8 and these changes were diminished by co-incubation with 200 μM FAC. We conclude that 1) the biological response following exposure to chrysotile is associated with complexation an

Palmdale International Airport, Palmdale, California. Airport Development Program

DTIC Science & Technology

1982-01-01

and ONT have rendered this system concept academic. • Concept B, described starting on page 209, is basically a reflection of the current situation...very different, and impacts the PIA in a very different manner. For example, the almost continuous use of the Complex 1 and Complex 4 MOAs will render ...been described in considerable detail by Underhill (n.d.), Strong (1929), and others ( Heizer 1978). Groups were subdivided into s~all bands

Factorials of real negative and imaginary numbers - A new perspective.

PubMed

Thukral, Ashwani K

2014-01-01

Presently, factorials of real negative numbers and imaginary numbers, except for zero and negative integers are interpolated using the Euler's gamma function. In the present paper, the concept of factorials has been generalised as applicable to real and imaginary numbers, and multifactorials. New functions based on Euler's factorial function have been proposed for the factorials of real negative and imaginary numbers. As per the present concept, the factorials of real negative numbers, are complex numbers. The factorials of real negative integers have their imaginary part equal to zero, thus are real numbers. Similarly, the factorials of imaginary numbers are complex numbers. The moduli of the complex factorials of real negative numbers, and imaginary numbers are equal to their respective real positive number factorials. Fractional factorials and multifactorials have been defined in a new perspective. The proposed concept has also been extended to Euler's gamma function for real negative numbers and imaginary numbers, and beta function.

Ingredients for Life (Artist's Concept)

NASA Technical Reports Server (NTRS)

2005-01-01

[figure removed for brevity, see original site] Figure 1: Artist's Conception Symbolically Represents Complex Organic Molecules

This artist's conception symbolically represents complex organic molecules, known as polycyclic aromatic hydrocarbons, seen in the early universe. These large molecules, comprised of carbon and hydrogen, are considered among the building blocks of life.

NASA's Spitzer Space Telescope is the first telescope to see polycyclic aromatic hydrocarbons so early -- 10 billion years further back in time than seen previously. Spitzer detected these molecules in galaxies when our universe was one-fourth of its current age of about 14 billion years.

These complex molecules are very common on Earth. They form any time carbon-based materials are not burned completely. They can be found in sooty exhaust from cars and airplanes, and in charcoal broiled hamburgers and burnt toast.

Polycyclic aromatic hydrocarbons are pervasive in galaxies like our own Milky Way, and play a significant role in star and planet formation.

Behaviour-Changing Ingredients in Soft Drinks: An Experiment Developed by School Children in Partnership with a Research Scientist

ERIC Educational Resources Information Center

Judge, Sarah; Delgaty, Laura; Broughton, Mark; Dyter, Laura; Grimes, Callum; Metcalf, James; Nicholson, Rose; Pennock, Erin; Jankowski, Karl

2017-01-01

A team of six children (13-14 years old) developed and conducted an experiment to assess the behaviour of the planarian flatworm, an invertebrate animal model, before, during and after exposure to chemicals. The aim of the project was to engage children in pharmacology and toxicology research. First, the concept that exposure to chemicals can…

Characterizing the Nature of Students' Feature Noticing-and-Using with Respect to Mathematical Symbols across Different Levels of Algebra Exposure

ERIC Educational Resources Information Center

Sullivan, Patrick

2013-01-01

The purpose of this study is to examine the nature of what students notice about symbols and use as they solve unfamiliar algebra problems based on familiar algebra concepts and involving symbolic inscriptions. The researcher conducted a study of students at three levels of algebra exposure: (a) students enrolled in a high school pre-calculus…

An empirical assessment of exposure measurement errors and effect attenuation in bi-pollutant epidemiologic models

EPA Science Inventory

Using multipollutant models to understand the combined health effects of exposure to multiple pollutants is becoming more common. However, the complex relationships between pollutants and differing degrees of exposure error across pollutants can make health effect estimates from ...

An empirical assessment of exposure measurement error and effect attenuation in bi-pollutant epidemiologic models

EPA Science Inventory

Background: Using multipollutant models to understand combined health effects of exposure to multiple pollutants is becoming more common. However, complex relationships between pollutants and differing degrees of exposure error across pollutants can make health effect estimates f...

Ingredients for Life Artist Concept

NASA Image and Video Library

2005-07-27

This artist conception symbolically represents complex organic molecules, known as polycyclic aromatic hydrocarbons, seen in the early universe. These large molecules, comprised of carbon and hydrogen, are considered among the building blocks of life.

Impact of a Small Cell on the RF-EMF Exposure in a Train

PubMed Central

Aerts, Sam; Plets, David; Thielens, Arno; Martens, Luc; Joseph, Wout

2015-01-01

The deployment of a miniature mobile-phone base station or small cell in a train car significantly improves the coverage and the capacity of a mobile network service on the train. However, the impact of the small cell on the passengers’ exposure to radio-frequency electromagnetic fields (RF-EMF) is unknown. In this study, we assessed experimentally the RF-EMF exposure of a mobile-phone user who is either connected to the outdoor macrocell network or to an in-train small cell, while traveling on the train, by means of the absorbed-dose concept, which combines the base station downlink exposure with the mobile-phone uplink exposure. For Global System for Mobile Communications (GSM) technology at 1800 MHz, we found that by connecting to a small cell, the brain exposure of the user could realistically be reduced by a factor 35 and the whole-body exposure by a factor 11. PMID:25734793

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

Kathy Held; Kevin Prise; Barry Michael

The management of the risks of exposure of people to ionizing radiation is important in relation to its uses in industry and medicine, also to natural and man-made radiation in the environment. The vase majority of exposures are at a very low level of radiation dose. The risks are of inducing cancer in the exposed individuals and a smaller risk of inducing genetic damage that can be indicate that they are low. As a result, the risks are impossible to detect in population studies with any accuracy above the normal levels of cancer and genetic defects unless the dose levelsmore » are high. In practice, this means that our knowledge depends very largely on the information gained from the follow-up of the survivors of the atomic bombs dropped on Japanese cities. The risks calculated from these high-dose short-duration exposures then have to be projected down to the low-dose long-term exposures that apply generally. Recent research using cells in culture has revealed that the relationship between high- and low-dose biological damage may be much more complex than had previously been thought. The aims of this and other projects in the DOE's Low-Dose Program are to gain an understanding of the biological actions of low-dose radiation, ultimately to provide information that will lead to more accurate quantification of low-dose risk. Our project is based on the concept that the processes by which radiation induces cancer start where the individual tracks of radiation impact on cells and tissues. At the dose levels of most low-dose exposures, these events are rare and any individual cells only ''sees'' radiation tracks at intervals averaging from weeks to years apart. This contrasts with the atomic bomb exposures where, on average, each cell was hit by hundreds of tracks instantaneously. We have therefore developed microbeam techniques that enable us to target cells in culture with any numbers of tracks, from one upwards. This approach enables us to study the biological ha sis of the relationship between high- and low-dose exposures. The targeting approach also allows us to study very clearly a newly recognized effect of radiation, the ''bystander effect'', which appears to dominate some low-dose responses and therefore may have a significant role in low-dose risk mechanisms. Our project also addresses the concept that the background of naturally occurring oxidative damage that takes place continually in cells due to byproducts of metabolism may play a role in low-dose radiation risk. This project therefore also examines how cells are damaged by treatments that modify the levels of oxidative damage, either alone or in combination with low-dose irradiation. In this project, we have used human and rodent cell lines and each set of experiments has been carried out on a single cell type. However, low-dose research has to extend into tissues because signaling between cells of different types is likely to influence the responses. Our studies have therefore also included microbeam experiments using a model tissue system that consists of an explant of a small piece of pig ureter grown in culture. The structure of this tissue is similar to that of epithelium and therefore it relates to the tissues in which carcinoma arises. Our studies have been able to measure bystander-induced changes in the cells growing out from the tissue fragment after it has been targeted with a few radiation tracks to mimic a low-dose exposure.« less

Spontaneous heparin-induced thrombocytopenia presenting as bilateral adrenal hemorrhages and pulmonary embolism after total knee arthroplasty.

PubMed

Elshoury, Amro; Khedr, Maha; Abousayed, Mostafa M; Mehdi, Syed

2015-09-01

Heparin-induced thrombocytopenia syndrome is an acquired potentially life-threatening prothrombotic disorder caused by antibodies that recognize complexes of platelet factor 4 bound to heparin or heparin-like molecules. It typically occurs after exposure to unfractionated heparin, to a lesser extent after exposure to low-molecular-weight heparins, and rarely after exposure to fondaparinux. Herein, we report the case of a 48-year-old woman who developed severe thrombocytopenia, bilateral pulmonary embolism, and bilateral adrenal hemorrhages after total knee arthroplasty without evidence of heparin exposure. Antibodies to the heparin-platelet factor 4 complex and serotonin-release assay were positive. Spontaneous heparin-induced thrombocytopenia syndrome should be considered in patients with unexplained thrombocytopenia after knee replacement surgery even without heparin exposure, and a high index of suspicion for adrenal hemorrhage is needed in patients with fever, abdominal pain, and shock.

Workplace Exposures and Cognitive Function During Adulthood: Evidence From National Survey of Midlife Development and the O*NET.

PubMed

Grzywacz, Joseph G; Segel-Karpas, Dikla; Lachman, Margie E

2016-06-01

Expand understanding of the role of selected workplace exposures (ie, occupational complexity, conflict in the workplace, pace of work, and physical hazards) in adults' cognitive function. Cross-sectional data (n = 1991) from the second wave of the Midlife in the United States (MIDUS) study; restricted to participants who completed telephone-based cognitive assessments of episodic memory, executive functioning, and self-perceived memory. Occupational exposure data were harvested from the ONET Release 6.0. Greater complexity was associated with better self-perceived memory among women and men, and better episodic memory and executive functioning among women. Greater physical hazards were independently associated with poorer episodic memory and executive functioning. Objective assessments of physical and psychosocial exposures in the workplace are independently associated with cognitive outcomes in adulthood, with psychosocial exposures being particularly pronounced among women.

Informatics Metrics and Measures for a Smart Public Health Systems Approach: Information Science Perspective

PubMed Central

Shea, Christopher Michael

2017-01-01

Public health informatics is an evolving domain in which practices constantly change to meet the demands of a highly complex public health and healthcare delivery system. Given the emergence of various concepts, such as learning health systems, smart health systems, and adaptive complex health systems, health informatics professionals would benefit from a common set of measures and capabilities to inform our modeling, measuring, and managing of health system “smartness.” Here, we introduce the concepts of organizational complexity, problem/issue complexity, and situational awareness as three codependent drivers of smart public health systems characteristics. We also propose seven smart public health systems measures and capabilities that are important in a public health informatics professional's toolkit. PMID:28167999

Informatics Metrics and Measures for a Smart Public Health Systems Approach: Information Science Perspective.

PubMed

Carney, Timothy Jay; Shea, Christopher Michael

2017-01-01

Public health informatics is an evolving domain in which practices constantly change to meet the demands of a highly complex public health and healthcare delivery system. Given the emergence of various concepts, such as learning health systems, smart health systems, and adaptive complex health systems, health informatics professionals would benefit from a common set of measures and capabilities to inform our modeling, measuring, and managing of health system "smartness." Here, we introduce the concepts of organizational complexity, problem/issue complexity, and situational awareness as three codependent drivers of smart public health systems characteristics. We also propose seven smart public health systems measures and capabilities that are important in a public health informatics professional's toolkit.

Sustainability: an evolutionary concept analysis. Exploring nursing's role within the sustainability movement.

PubMed

McMillan, Kimberly

2014-04-01

This paper aimed to explore the evolution of the concept of sustainability to facilitate further knowledge development in the discipline of nursing. The concept of 'sustainability' emerged in the 1950s as a result of the environmental movement. The concept has been adapted by the discipline of management and is increasingly discussed in the context of health care. The concept remains ambiguous in the discipline of nursing, resulting in a struggle to articulate the role of nursing in the sustainability movement. Rodgers evolutionary method of concept analysis was used. Literature was searched from 1987-2011, including English, peer reviewed texts in the databases CINAHL and ABI/INFORM global. Two book chapters and grey literature were also included. References were read and analysed according to antecedents, attributes, consequences, surrogate terms and related terms. Defining antecedents, attributes and consequences highlight the complexity and diversity of the concept. Attributes include: sustainability as a condition of change, as process, as outcome, as dependent of multiple stakeholders, and as social consciousness. 'Sustainability' is a fragile concept highly dependent on the processes and stakeholders involved in its fruition. There is a distinct difference in the level of concept clarity between the disciplines of management and nursing. The complexities associated with the concept of 'Sustainability' have led to its ambiguity. Nursing must, however, work to further clarify the concept to fully understand nursing's potential role in the sustainability movement. © 2013 John Wiley & Sons Ltd.

Concepts and their dynamics: a quantum-theoretic modeling of human thought.

PubMed

Aerts, Diederik; Gabora, Liane; Sozzo, Sandro

2013-10-01

We analyze different aspects of our quantum modeling approach of human concepts and, more specifically, focus on the quantum effects of contextuality, interference, entanglement, and emergence, illustrating how each of them makes its appearance in specific situations of the dynamics of human concepts and their combinations. We point out the relation of our approach, which is based on an ontology of a concept as an entity in a state changing under influence of a context, with the main traditional concept theories, that is, prototype theory, exemplar theory, and theory theory. We ponder about the question why quantum theory performs so well in its modeling of human concepts, and we shed light on this question by analyzing the role of complex amplitudes, showing how they allow to describe interference in the statistics of measurement outcomes, while in the traditional theories statistics of outcomes originates in classical probability weights, without the possibility of interference. The relevance of complex numbers, the appearance of entanglement, and the role of Fock space in explaining contextual emergence, all as unique features of the quantum modeling, are explicitly revealed in this article by analyzing human concepts and their dynamics. © 2013 Cognitive Science Society, Inc.

The Complexity of Teaching Density in Middle School

ERIC Educational Resources Information Center

Hashweh, Maher Z.

2016-01-01

Background: Density is difficult to learn and teach in middle schools. This study, hypothesizing that the density concept develops as part of a conceptual system, used a conceptual change approach to teaching density. The approach emphasized the use of multiple strategies to teach the density concept and the associated concepts in the conceptual…

Dialysis, Albumin Binding, and Competitive Binding: A Laboratory Lesson Relating Three Chemical Concepts to Healthcare

ERIC Educational Resources Information Center

Domingo, Jennifer P.; Abualia, Mohammed; Barragan, Diana; Schroeder, Lianne; Wink, Donald J.; King, Maripat; Clark, Ginevra A.

2017-01-01

Introductory Chemistry laboratories must go beyond "cookbook" methods to illustrate how chemistry concepts apply to complex, real-world problems. In our case, we are preparing students to use their chemistry knowledge in the healthcare profession. The experiment described here explicitly models three important chemical concepts: dialysis…

Exploring High School Students' Perceptions of Solar Energy and Solar Cells

ERIC Educational Resources Information Center

Kishore, Padmini; Kisiel, James

2013-01-01

Although studies examining student understanding of key concepts are common throughout the science education literature, few have examined science concepts linked to conservation or environmental issues such as global warming and alternative energy. How students make sense of these complex concepts has the potential to influence their role as…

From Access to Success: An Integrated Approach to Quality Higher Education Informed by Social Inclusion Theory and Practice

ERIC Educational Resources Information Center

Gidley, Jennifer M.; Hampson, Gary P.; Wheeler, Leone; Bereded-Samuel, Elleni

2010-01-01

Equitable access, success and quality in higher education are examined from a variety of ideological perspectives. "Quality" is positioned as a complex generic concept while "access" and "success" are identified as key concepts in the social inclusion domain, supplemented by the concept of "participation."…

American Homelands: Classroom Approaches towards a Complex Concept

ERIC Educational Resources Information Center

Post, Chris W.

2008-01-01

Geographers, along with anthropologists and sociologists, have been debating the homeland concept as it applies in North America for decades. In recent years, the political ideology of the war on terror has added another dimension to this discussion. If the attention given to the concept by introductory textbooks is any indication, homelands are…

Integrating Six Sigma Concepts in an MBA Quality Management Class

ERIC Educational Resources Information Center

Weinstein, Larry B.; Petrick, Joseph; Castellano, Joseph; Vokurka, Robert J.

2008-01-01

Instructors face enormous challenges in presenting effective instruction on concepts and tools of quality management. Most textbooks focus on presenting individual concepts or tools and fail to address complex issues confronted in real-world problem-solving situations. The supplementary use of cases does not help students to understand the dynamic…

Complex Multi-Chamber Airbag Performance Simulation Final Report CRADA No. TSB-961-94

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

Kay, Gregory; Kithil, Philip

The purpose of this small business CRADA was to evaluate the performance of new airbag concepts which were developed by the Advanced Safety Concepts, Inc. (ASCI). These new airbag concepts, if successful, could have major potential savings to society in terms of fewer injuries, lost time and lives.

A theory-based approach to teaching young children about health: A recipe for understanding

PubMed Central

Nguyen, Simone P.; McCullough, Mary Beth; Noble, Ashley

2011-01-01

The theory-theory account of conceptual development posits that children’s concepts are integrated into theories. Concept learning studies have documented the central role that theories play in children’s learning of experimenter-defined categories, but have yet to extensively examine complex, real-world concepts such as health. The present study examined whether providing young children with coherent and causally-related information in a theory-based lesson would facilitate their learning about the concept of health. This study used a pre-test/lesson/post-test design, plus a five month follow-up. Children were randomly assigned to one of three conditions: theory (i.e., 20 children received a theory-based lesson); nontheory (i.e., 20 children received a nontheory-based lesson); and control (i.e., 20 children received no lesson). Overall, the results showed that children in the theory condition had a more accurate conception of health than children in the nontheory and control conditions, suggesting the importance of theories in children’s learning of complex, real-world concepts. PMID:21894237

New head exposure system for use in human provocation studies with EEG recording during GSM900- and UMTS-like exposure.

PubMed

Schmid, Gernot; Cecil, Stefan; Goger, Christoph; Trimmel, Michael; Kuster, Niels; Molla-Djafari, Hamid

2007-12-01

A new head exposure system for double blinded human provocation studies, which requires EEG recording during exposure with GSM900- and UMTS-like signals has been developed and dosimetrically evaluated. The system uses planar patch antennas fixed at 65 mm distance from the subject's head by a special headset, which provides minimum impairment of the test subjects and ensures an almost constant position of the antennas with respect to the head, even in case of head movements. Compared to exposure concepts operating small antennas in close proximity to the head, the concept of planar antennas at a certain distance from the head produces a much more homogeneous SAR distribution in the temporal and parietal lobe of the brain. At the same time the resulting uncertainty of exposure due to variations in head size, variations of the dielectric properties of tissues and unavoidable small changes of the antenna's position with respect to the head, is reduced to the order of approximately 3 dB, which is a significant improvement to comparable head exposure systems reported in literature in the past. To avoid electromagnetic interference on the EEG recording caused by the incident RF-field an appropriate double-shielded filter circuit has been developed. Furthermore, the effect of the presence of the sintered Ag/AgCl EEG electrodes and electrode wires on the SAR distribution inside the head has been investigated and was found to be minimal if the electrode wires are arranged orthogonal to the incident electric field vector. EEG electrode arrangement parallel to the incident field vector, however, might cause drastic changes in the SAR distribution inside the head. (c) 2007 Wiley-Liss, Inc.

How Does Exposure to Cigarette Advertising Contribute to Smoking in Adolescents? The Role of the Developing Self-Concept and Identification with Advertising Models

PubMed Central

Shadel, William G.; Tharp-Taylor, Shannah; Fryer, Craig S.

2009-01-01

Increased exposure to cigarette advertisements is associated with increases in adolescent smoking but the reasons for this association are not well established. This study evaluated whether self-concept development (operationalized as level of self-conflict) and identifying with the models used in cigarette print advertising contributed to smoking intentions among adolescents. Ninety-five adolescents (ages 11-17) participated in this two session study. In session 1, they rated the extent to which they identified with the models used in 10 current cigarette print ads (the models were isolated digitally from the cigarette advertisements) and their level of self-conflict was assessed. In session 2, participants viewed each of the 10 cigarette advertisements from which the models were drawn and rated their intentions to smoke following exposure to each ad. Model identification was associated with similar levels of post ad exposure smoking intentions for both younger and older adolescents when they also exhibited no self-conflict. A contrasting set of findings emerged for younger and older adolescents when they exhibited high levels of self-conflict: Young adolescents who strongly identified with the models used in cigarette advertisements had higher post ad exposure smoking intentions compared to younger adolescents who weakly identified with the models used in the advertisements; in contrast, older adolescents who weakly identified with the models used in cigarette advertisements had stronger post ad exposure smoking intentions compared to older adolescents who strongly identified with the models used in the advertisements. These results point to the importance of examining developmentally-relevant moderators for the effects of cigarette advertising exposure. PMID:19505768

How does exposure to cigarette advertising contribute to smoking in adolescents? The role of the developing self-concept and identification with advertising models.

PubMed

Shadel, William G; Tharp-Taylor, Shannah; Fryer, Craig S

2009-11-01

Increased exposure to cigarette advertisements is associated with increases in adolescent smoking but the reasons for this association are not well established. This study evaluated whether self-concept development (operationalized as level of self-conflict) and identifying with the models used in cigarette print advertising contributed to smoking intentions among adolescents. Ninety-five adolescents (ages 11-17) participated in this two session study. In session 1, they rated the extent to which they identified with the models used in 10 current cigarette print ads (the models were isolated digitally from the cigarette advertisements) and their level of self-conflict was assessed. In session 2, participants viewed each of the 10 cigarette advertisements from which the models were drawn and rated their intentions to smoke following exposure to each ad. Model identification was associated with similar levels of post ad exposure smoking intentions for both younger and older adolescents when they also exhibited no self-conflict. A contrasting set of findings emerged for younger and older adolescents when they exhibited high levels of self-conflict: Young adolescents who strongly identified with the models used in cigarette advertisements had higher post ad exposure smoking intentions compared to younger adolescents who weakly identified with the models used in the advertisements; in contrast, older adolescents who weakly identified with the models used in cigarette advertisements had stronger post ad exposure smoking intentions compared to older adolescents who strongly identified with the models used in the advertisements. These results point to the importance of examining developmentally-relevant moderators for the effects of cigarette advertising exposure.

Objects and processes: Two notions for understanding biological information.

PubMed

Mercado-Reyes, Agustín; Padilla-Longoria, Pablo; Arroyo-Santos, Alfonso

2015-09-07

In spite of being ubiquitous in life sciences, the concept of information is harshly criticized. Uses of the concept other than those derived from Shannon׳s theory are denounced as metaphoric. We perform a computational experiment to explore whether Shannon׳s information is adequate to describe the uses of said concept in commonplace scientific practice. Our results show that semantic sequences do not have unique complexity values different from the value of meaningless sequences. This result suggests that quantitative theoretical frameworks do not account fully for the complex phenomenon that the term "information" refers to. We propose a restructuring of the concept into two related, but independent notions, and conclude that a complete theory of biological information must account completely not only for both notions, but also for the relationship between them. Copyright © 2015 Elsevier Ltd. All rights reserved.

Are archetypes transmitted or emergent? A response to Christian Roesler.

PubMed

Martin-Vallas, François

2013-04-01

In this paper the author argues that Jung's concept of archetype should not be reduced to an univocal definition. Jung himself proposed many definitions of this concept, some of them being partially or totally contradictory to others. A univocal and logical way of thinking can lead us to refute and reject part of those definitions, but a complex way of thinking, as proposed by Edgar Morin or Roy Bhaskar for example, can allow us to consider that those apparent contradictions in Jung's definitions of archetype reflect the complexity of the psychic reality. The main argument of the author is that Jung was missing the epistemological concept of emergence (which appeared in science at the time of his death) and that he tried to express it with the epistemological concepts of his time. © 2013, The Society of Analytical Psychology.

Quality assurance of chemical ingredient classification for the National Drug File - Reference Terminology.

PubMed

Zheng, Ling; Yumak, Hasan; Chen, Ling; Ochs, Christopher; Geller, James; Kapusnik-Uner, Joan; Perl, Yehoshua

2017-09-01

The National Drug File - Reference Terminology (NDF-RT) is a large and complex drug terminology consisting of several classification hierarchies on top of an extensive collection of drug concepts. These hierarchies provide important information about clinical drugs, e.g., their chemical ingredients, mechanisms of action, dosage form and physiological effects. Within NDF-RT such information is represented using tens of thousands of roles connecting drugs to classifications. In previous studies, we have introduced various kinds of Abstraction Networks to summarize the content and structure of terminologies in order to facilitate their visual comprehension, and support quality assurance of terminologies. However, these previous kinds of Abstraction Networks are not appropriate for summarizing the NDF-RT classification hierarchies, due to its unique structure. In this paper, we present the novel Ingredient Abstraction Network (IAbN) to summarize, visualize and support the audit of NDF-RT's Chemical Ingredients hierarchy and its associated drugs. A common theme in our quality assurance framework is to use characterizations of sets of concepts, revealed by the Abstraction Network structure, to capture concepts, the modeling of which is more complex than for other concepts. For the IAbN, we characterize drug ingredient concepts as more complex if they belong to IAbN groups with multiple parent groups. We show that such concepts have a statistically significantly higher rate of errors than a control sample and identify two especially common patterns of errors. Copyright © 2017 Elsevier Inc. All rights reserved.

The joint effect of air pollution exposure and copy number variation on risk for autism.

PubMed

Kim, Dokyoon; Volk, Heather; Girirajan, Santhosh; Pendergrass, Sarah; Hall, Molly A; Verma, Shefali S; Schmidt, Rebecca J; Hansen, Robin L; Ghosh, Debashis; Ludena-Rodriguez, Yunin; Kim, Kyoungmi; Ritchie, Marylyn D; Hertz-Picciotto, Irva; Selleck, Scott B

2017-09-01

Autism spectrum disorder is a complex trait with a high degree of heritability as well as documented susceptibility from environmental factors. In this study the contributions of copy number variation, exposure to air pollutants, and the interaction between the two on autism risk, were evaluated in the population-based case-control Childhood Autism Risks from Genetics and Environment (CHARGE) Study. For the current investigation, we included only those CHARGE children (a) who met criteria for autism or typical development and (b) for whom our team had conducted both genetic evaluation of copy number burden and determination of environmental air pollution exposures based on mapping addresses from the pregnancy and early childhood. This sample consisted of 158 cases of children with autism and 147 controls with typical development. Multiple logistic regression models were fit with and without environmental variable-copy number burden interactions. We found no correlation between average air pollution exposure from conception to age 2 years and the child's CNV burden. We found a significant interaction in which a 1SD increase in duplication burden combined with a 1SD increase in ozone exposure was associated with an elevated autism risk (OR 3.4, P < 0.005) much greater than the increased risks associated with either genomic duplication (OR 1.85, 95% CI 1.25-2.73) or ozone (OR 1.20, 95% CI 0.93-1.54) alone. Similar results were obtained when CNV and ozone were dichotomized to compare those in the top quartile relative to those having a smaller CNV burden and lower exposure to ozone, and when exposures were assessed separately for pregnancy, the first year of life, and the second year of life. No interactions were observed for other air pollutants, even those that demonstrated main effects; ozone tends to be negatively correlated with the other pollutants examined. While earlier work has demonstrated interactions between the presence of a pathogenic CNV and an environmental exposure [Webb et al., 2016], these findings appear to be the first indication that global copy number variation may increase susceptibility to certain environmental factors, and underscore the need to consider both genomics and environmental exposures as well as the mechanisms by which each may amplify the risks for autism associated with the other. Autism Res 2017, 10: 1470-1480. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

Complex mixtures, complex responses: Assessing pharmaceutical mixtures using field and laboratory approaches

USGS Publications Warehouse

Schoenfuss, Heiko L.; Furlong, Edward T.; Phillips, Patrick J.; Scott, Tia-Marie; Kolpin, Dana W.; Cetkovic-Cvrlje, Marina; Lesteberg, Kelsey E.; Rearick, Daniel C.

2016-01-01

Pharmaceuticals are present in low concentrations (<100 ng/L) in most municipal wastewater effluents but may be elevated locally because of factors such as input from pharmaceutical formulation facilities. Using existing concentration data, the authors assessed pharmaceuticals in laboratory exposures of fathead minnows (Pimephales promelas) and added environmental complexity through effluent exposures. In the laboratory, larval and mature minnows were exposed to a simple opioid mixture (hydrocodone, methadone, and oxycodone), an opioid agonist (tramadol), a muscle relaxant (methocarbamol), a simple antidepressant mixture (fluoxetine, paroxetine, venlafaxine), a sleep aid (temazepam), or a complex mixture of all compounds. Larval minnow response to effluent exposure was not consistent. The 2010 exposures resulted in shorter exposed minnow larvae, whereas the larvae exposed in 2012 exhibited altered escape behavior. Mature minnows exhibited altered hepatosomatic indices, with the strongest effects in females and in mixture exposures. In addition, laboratory-exposed, mature male minnows exposed to all pharmaceuticals (except the selective serotonin reuptake inhibitor mixture) defended nest sites less rigorously than fish in the control group. Tramadol or antidepressant mixture exposure resulted in increased splenic T lymphocytes. Only male minnows exposed to whole effluent responded with increased plasma vitellogenin concentrations. Female minnows exposed to pharmaceuticals (except the opioid mixture) had larger livers, likely as a compensatory result of greater prominence of vacuoles in liver hepatocytes. The observed alteration of apical endpoints central to sustaining fish populations confirms that effluents containing waste streams from pharmaceutical formulation facilities can adversely impact fish populations but that the effects may not be temporally consistent. The present study highlights the importance of including diverse biological endpoints spanning levels of biological organization and life stages when assessing contaminant interactions.

Modulation of redox regulatory molecules and electron transport chain activity in muscle of air breathing fish Heteropneustes fossilis under air exposure stress.

PubMed

Paital, Biswaranjan

2014-01-01

Responses of redox regulatory system to long-term survival (>18 h) of the catfish Heteropneustes fossilis in air are not yet understood. Lipid and protein oxidation level, oxidant (H2O2) generation, antioxidative status (levels of superoxide dismutase, catalase, glutathione peroxidase and reductase, ascorbic acid and non-protein sulfhydryl) and activities of respiratory complexes (I, II, III and IV) in mitochondria were investigated in muscle of H. fossilis under air exposure condition (0, 3, 6, 12 and 18 h at 25 °C). The increased levels of both H2O2 and tissue oxidation were observed due to the decreased activities of antioxidant enzymes in muscle under water deprivation condition. However, ascorbic acid and non-protein thiol groups were the highest at 18 h air exposure time. A linear increase in complex II activity with air exposure time and an increase up to 12 h followed by a decrease in activity of complex I at 18 h were observed. Negative correlation was observed for complex III and V activity with exposure time. Critical time to modulate the above parameters was found to be 3 h air exposure. Dehydration induced oxidative stress due to modulation of electron transport chain and redox metabolizing enzymes in muscle of H. fossilis was clearly observed. Possible contribution of redox regulatory system in muscle tissue of the fish for long-term survival in air is elucidated. Results of the present study may be useful to understand the redox metabolism in muscle of fishes those are exposed to air in general and air breathing fishes in particular.

Maternal exposure to brominated flame retardants and infant Apgar scores.

PubMed

Terrell, Metrecia L; Hartnett, Kathleen P; Lim, Hyeyeun; Wirth, Julie; Marcus, Michele

2015-01-01

Brominated flame retardants (BFRs) and other persistent organic pollutants have been associated with adverse health outcomes in humans and may be particularly toxic to the developing fetus. We investigated the association between in utero polybrominated biphenyl (PBB) and polychlorinated biphenyl (PCB) exposures and infant Apgar scores in a cohort of Michigan residents exposed to PBB through contaminated food after an industrial accident. PBB and PCB concentrations were measured in serum at the time the women were enrolled in the cohort. PBB concentrations were also estimated at the time of conception for each pregnancy using a validated elimination model. Apgar scores, a universal measure of infant health at birth, measured at 1 and 5min, were taken from birth certificates for 613 offspring born to 330 women. Maternal PCB concentrations at enrollment were not associated with below-median Apgar scores in this cohort. However, maternal PBB exposure was associated with a dose-related increase in the odds of a below-median Apgar score at 1min and 5min. Among infants whose mothers had an estimated PBB at conception above the limit of detection of 1 part per billion (ppb) to <2.5ppb, the odds ratio=2.32 (95% CI: 1.22-4.40); for those with PBB⩾2.5ppb the OR=2.62 (95% CI: 1.38-4.96; test for trend p<0.01). Likewise, the odds of a below-median 5min Apgar score increased with higher maternal PBB at conception. It remains critical that future studies examine possible relationships between in utero exposures to brominated compounds and adverse health outcomes. Copyright © 2014 Elsevier Ltd. All rights reserved.

Complexity in Soil Systems: What Does It Mean and How Should We Proceed?

NASA Astrophysics Data System (ADS)

Faybishenko, B.; Molz, F. J.; Brodie, E.; Hubbard, S. S.

2015-12-01

The complex soil systems approach is needed fundamentally for the development of integrated, interdisciplinary methods to measure and quantify the physical, chemical and biological processes taking place in soil, and to determine the role of fine-scale heterogeneities. This presentation is aimed at a review of the concepts and observations concerning complexity and complex systems theory, including terminology, emergent complexity and simplicity, self-organization and a general approach to the study of complex systems using the Weaver (1948) concept of "organized complexity." These concepts are used to provide understanding of complex soil systems, and to develop experimental and mathematical approaches to soil microbiological processes. The results of numerical simulations, observations and experiments are presented that indicate the presence of deterministic chaotic dynamics in soil microbial systems. So what are the implications for the scientists who wish to develop mathematical models in the area of organized complexity or to perform experiments to help clarify an aspect of an organized complex system? The modelers have to deal with coupled systems having at least three dependent variables, and they have to forgo making linear approximations to nonlinear phenomena. The analogous rule for experimentalists is that they need to perform experiments that involve measurement of at least three interacting entities (variables depending on time, space, and each other). These entities could be microbes in soil penetrated by roots. If a process being studied in a soil affects the soil properties, like biofilm formation, then this effect has to be measured and included. The mathematical implications of this viewpoint are examined, and results of numerical solutions to a system of equations demonstrating deterministic chaotic behavior are also discussed using time series and the 3D strange attractors.

EXPOSURE-DOSE-RESPONSE MODELING OF THE NEUROTOXIC EFFECTS OF ORGANIC SOLVENTS.

EPA Science Inventory

Risk assessments based on exposure to volatile organic compounds (VOCs) are hampered by the complexities of exposure scenarios, a lack of data regarding the mode of action of the VOCs, and uncertainties about extrapolating from animal data to human health risk. We are developing ...

Control of Future Air Traffic Systems via Complexity Bound Management

NASA Technical Reports Server (NTRS)

Alexandrov, Natalia

2013-01-01

The complexity of the present system for managing air traffic has led to "discreteness" in approaches to creating new concepts: new concepts are created as point designs, based on experience, expertise, and creativity of the proposer. Discrete point designs may be highly successful but they are difficult to substantiate in the face of equally strong substantiation of competing concepts, as well as the state of the art in concept evaluation via simulations. Hybrid concepts may present a compromise - the golden middle. Yet a hybrid of sometimes in principle incompatible concepts forms another point design that faces the challenge of substantiation and validation. We are faced with the need to re-design the air transportation system ab initio. This is a daunting task, especially considering the problem of transitioning from the present system to any fundamentally new system. However, design from scratch is also an opportunity to reconsider approaches to new concept development. In this position paper we propose an approach, Optimized Parametric Functional Design, for systematic development of concepts for management and control of airspace systems, based on optimization formulations in terms of required system functions and states. This reasoning framework, realizable in the context of ab initio system design, offers an approach to deriving substantiated airspace management and control concepts. With growing computational power, we hope that the approach will also yield a methodology for actual dynamic control of airspace

Chronic exposure to nitric oxide alters the free iron pool in endothelial cells: Role of mitochondrial respiratory complexes and heat shock proteins

PubMed Central

Ramachandran, Anup; Ceaser, Erin; Darley-Usmar, Victor M.

2004-01-01

The mechanisms of nitric oxide (NO) signaling include binding to the iron centers in soluble guanylate cyclase and cytochrome c oxidase and posttranslational modification of proteins by S-nitrosation. Low levels of NO control mitochondrial number in cells, but little is known of the impact of chronic exposure to high levels of NO on mitochondrial function in endothelial cells. The focus of this study is the interaction of NO with mitochondrial respiratory complexes in cell culture and the effect this has on iron homeostasis. We demonstrate that chronic exposure of endothelial cells to NO decreased activity and protein levels of complexes I, II, and IV, whereas citrate synthase and ATP synthase were unaffected. Inhibition of these respiratory complexes was accompanied by an increase in cellular S-nitrosothiol levels, modification of cysteines residues, and an increase in the labile iron pool. The NO-dependent increase in the free iron pool and inhibition of complex II was prevented by inhibition of mitochondrial protein synthesis, consistent with a major contribution of the organelle to iron homeostasis. In addition, inhibition of mitochondrial protein synthesis was associated with an increase in heat shock protein 60 levels, which may be an additional mechanism leading to preservation of complex II activity. PMID:14691259

Lesion complexity drives age related cancer susceptibility in human mammary epithelial cells

DOE PAGES

Sridharan, Deepa M.; Enerio, Shiena; Stampfer, Martha M.; ...

2017-02-28

Exposures to various DNA damaging agents can deregulate a wide array of critical mechanisms that maintain genome integrity. It is unclear how these processes are impacted by one's age at the time of exposure and the complexity of the DNA lesion. To clarify this, we employed radiation as a tool to generate simple and complex lesions in normal primary human mammary epithelial cells derived from women of various ages. We hypothesized that genomic instability in the progeny of older cells exposed to complex damages will be exacerbated by age-associated deterioration in function and accentuate age-related cancer predisposition. Centrosome aberrations andmore » changes in stem cell numbers were examined to assess cancer susceptibility. Our data show that the frequency of centrosome aberrations proportionately increases with age following complex damage causing exposures. However, a dose-dependent increase in stem cell numbers was independent of both age and the nature of the insult. Phospho-protein signatures provide mechanistic clues to signaling networks implicated in these effects. Together these studies suggest that complex damage can threaten the genome stability of the stem cell population in older people. Propagation of this instability is subject to influence by the microenvironment and will ultimately define cancer risk in the older population.« less

Lesion complexity drives age related cancer susceptibility in human mammary epithelial cells

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

Sridharan, Deepa M.; Enerio, Shiena; Stampfer, Martha M.

Exposures to various DNA damaging agents can deregulate a wide array of critical mechanisms that maintain genome integrity. It is unclear how these processes are impacted by one's age at the time of exposure and the complexity of the DNA lesion. To clarify this, we employed radiation as a tool to generate simple and complex lesions in normal primary human mammary epithelial cells derived from women of various ages. We hypothesized that genomic instability in the progeny of older cells exposed to complex damages will be exacerbated by age-associated deterioration in function and accentuate age-related cancer predisposition. Centrosome aberrations andmore » changes in stem cell numbers were examined to assess cancer susceptibility. Our data show that the frequency of centrosome aberrations proportionately increases with age following complex damage causing exposures. However, a dose-dependent increase in stem cell numbers was independent of both age and the nature of the insult. Phospho-protein signatures provide mechanistic clues to signaling networks implicated in these effects. Together these studies suggest that complex damage can threaten the genome stability of the stem cell population in older people. Propagation of this instability is subject to influence by the microenvironment and will ultimately define cancer risk in the older population.« less

Reexamination of METMAN, Recommendations on Enhancement of LCVG, and Development of New Concepts for EMU Heat Sink

NASA Technical Reports Server (NTRS)

Karimi, Amir

1990-01-01

METMAN is a 41-node transient metabolic computer code developed in 1970 and revised in 1989 by Lockheed Engineering and Sciences, Inc. This program relies on a mathematical model to predict the transient temperature distribution in a body influenced by metabolic heat generation and thermal interaction with the environment. A more complex 315-node model is also available that not only simulates the thermal response of a body exposed to a warm environment, but is also capable of describing the thermal response resulting from exposure to a cold environment. It is important to compare the two models for the prediction of the body's thermal response to metabolic heat generation and exposure to various environmental conditions. Discrepancies between the twi models may warrant an investigation of METMAN to ensure its validity for describing the body's thermal response in space environment. The Liquid Cooling and Ventilation Garment is a subsystem of the Extravehicular Mobility Unit (EMU). This garment, worn under the pressure suit, contains the liquid cooling tubing and gas ventilation manifolds; its purpose is to alleviate or reduce thermal stress resulting from metabolic heat generation. There is renewed interest in modifying this garment through identification of the locus of maximum heat transfer at body-liquid cooled tubing interface. The sublimator is a vital component of the Primary Life Support System (PLSS) in the EMU. It acts as a heat sink to remove heat and humidity from the gas ventilating circuit and the liquid cooling loop of the LCVG. The deficiency of the sublimator is that the ice, used as the heat sink, sublimates into space. There is an effort to minimize water losses in the feedwater circuit of the EMU. This requires developing new concepts to design an alternative heat sink system. Efforts are directed to review and verify the heat transfer formulation of the analytical model employed by METMAN. A conceptual investigation of regenerative non-venting heat-sink subsystem for the EMU is recommended.

Optical monitoring of gases with cholesteric liquid crystals.

PubMed

Han, Yang; Pacheco, Katherine; Bastiaansen, Cees W M; Broer, Dirk J; Sijbesma, Rint P

2010-03-10

A new approach to optical monitors for gases is introduced using cholesteric liquid crystals doped with reactive chiral compounds. The approach is based on cholesteric pitch length changes caused by a change in helical twisting power (HTP) of the chiral dopants upon reaction with the analyte. The concept is demonstrated for monitoring carbon dioxide via reversible carbamate formation and for oxygen using the irreversible oxidation of a chiral dithiol to a disulfide. Monitoring of CO(2) was achieved by doping a commercial cholesteric liquid crystalline mixture (E7) with 1.6% mol of the 1:1 complex of an optically pure diamine with a TADDOL derivative. Upon exposure to carbon dioxide, the reflection band of a thin film of the mixture shifted from 637 to 495 nm as a consequence of dissociation of the complex after carbamate formation of the diamine. An O(2) monitor was obtained by doping E7 with a chiral binaphthyl dithiol derivative and a nonresponsive codopant. The reflection band of the oxygen monitor film changed from 542 to 600 nm, due to the conformational change accompanying oxidation of the dithiol to disulfide. These monitoring mechanisms hold promise for application in smart packaging, where carbon dioxide and oxygen are of special interest because of their roles in food preservation.

Application of multi-function display and control technology

NASA Technical Reports Server (NTRS)

Spiger, R. J.; Farrell, R. J.; Holcomb, G. A.

1982-01-01

The NASA orbiter spacecraft incorporates a complex array of systems, displays, and controls. The incorporation of discrete dedicated controls into a multifunction display and control system (MFDCS) offers the potential for savings in weight, power, panel space, and crew training time. Technology identified as applicable to a MFDCS is applied to the orbiter orbital maneuvering system (OMS) and the electrical power distribution and control system (EPDCS) to derive concepts for a MFDCS design. Several concepts of varying degrees of performance and complexity are discussed and a suggested concept for further development is presented in greater detail. Both the hardware and software aspects and the human factors considerations of the designs are included.

The Nordic concept of 'faellesskab'.

PubMed Central

Riis, P

1991-01-01

The complex of cultural, political and societal affiliations, both in a historic and a contemporary perspective, is expressed by a special term in the Nordic languages, 'faellesskab', often with the addition of 'folkelig', as 'folkeligt faellesskab', where 'folkelig' means of the people. No corresponding term exists in English. For medical ethics the concept 'faellesskab', or whatever wording is chosen to serve the semantics of this term, is vital. In research ethics and clinical decision-making complex ethical analyses and normative evaluations are necessary. They cannot be based solely on moral relativism, whether being based on results of opinion polls or on a widespread 'every man minds his own business' concept. 'Faellesskab' possesses the necessary base of common values. PMID:2033630

The BAF (BRG1/BRM-Associated Factor) chromatin-remodeling complex exhibits ethanol sensitivity in fetal neural progenitor cells and regulates transcription at the miR-9-2 encoding gene locus.

PubMed

Burrowes, Sasha G; Salem, Nihal A; Tseng, Alexander M; Balaraman, Sridevi; Pinson, Marisa R; Garcia, Cadianna; Miranda, Rajesh C

2017-05-01

Fetal alcohol spectrum disorders are a leading cause of intellectual disability worldwide. Previous studies have shown that developmental ethanol exposure results in loss of microRNAs (miRNAs), including miR-9, and loss of these miRNAs, in turn, mediates some of ethanol's teratogenic effects in the developing brain. We previously found that ethanol increased methylation at the miR-9-2 encoding gene locus in mouse fetal neural stem cells (NSC), advancing a mechanism for epigenetic silencing of this locus and consequently, miR-9 loss in NSCs. Therefore, we assessed the role of the BAF (BRG1/BRM-Associated Factor) complex, which disassembles nucleosomes to facilitate access to chromatin, as an epigenetic mediator of ethanol's effects on miR-9. Chromatin immunoprecipitation and DNAse I-hypersensitivity analyses showed that the BAF complex was associated with both transcriptionally accessible and heterochromatic regions of the miR-9-2 locus, and that disintegration of the BAF complex by combined knockdown of BAF170 and BAF155 resulted in a significant decrease in miR-9. We hypothesized that ethanol exposure would result in loss of BAF-complex function at the miR-9-2 locus. However, ethanol exposure significantly increased mRNA transcripts for maturation-associated BAF-complex members BAF170, SS18, ARID2, BAF60a, BRM/BAF190b, and BAF53b. Ethanol also significantly increased BAF-complex binding within an intron containing a CpG island and in the terminal exon encoding precursor (pre)-miR-9-2. These data suggest that the BAF complex may adaptively respond to ethanol exposure to protect against a complete loss of miR-9-2 in fetal NSCs. Chromatin remodeling factors may adapt to the presence of a teratogen, to maintain transcription of critical miRNA regulatory pathways. Copyright © 2017 Elsevier Inc. All rights reserved.

The Aristotle method: a new concept to evaluate quality of care based on complexity.

PubMed

Lacour-Gayet, François; Clarke, David R

2005-06-01

Evaluation of quality of care is a duty of the modern medical practice. A reliable method of quality evaluation able to compare fairly institutions and inform a patient and his family of the potential risk of a procedure is clearly needed. It is now well recognized that any method that purports to evaluate quality of care should include a case mix/risk stratification method. No valuable method was available until recently in pediatric cardiac surgery. The Aristotle method is a new concept of evaluation of quality of care in congenital heart surgery based on the complexity of the surgical procedures. Involving a panel of expert surgeons, the project started in 1999 and included 50 pediatric surgeons from 23 countries. The basic score adjusts the complexity of a given procedure and is calculated as the sum of potential for mortality, potential for morbidity and anticipated technical difficulty. The Comprehensive Score further adjusts the complexity according to the specific patient characteristics (anatomy, associated procedures, co-morbidity, etc.). The Aristotle method is original as it introduces several new concepts: the calculated complexity is a constant for a given patient all over the world; complexity is an independent value and risk is a variable depending on the performance; and Performance = Complexity x Outcome. The Aristotle score is a good vector of communication between patients, doctors and insurance companies and may stimulate the quality and the organization of heath care in our field and in others.

Understanding Environmental Tobacco Smoke Exposure and Effects in Asthmatic Children through Determination of Urinary Cotinine and Targeted Metabolomics of Plasma

EPA Science Inventory

Understanding Environmental Tobacco Smoke Exposure and Effects in Asthmatic Children through Determination of Urinary Cotinine and Targeted Metabolomics of Plasma Introduction Asthma is a complex disease with multiple triggers and causal factors, Exposure to environmental tob...

Co-exposure to ultrafine particulate matter and ozone causes electrocardiogram changes indicative of increased arrhythmia risk in mice

EPA Science Inventory

Numerous studies have shown a relationship between acute air pollution exposure and increased risk for cardiovascular morbidity and mortality. Due to the inherent complexity of air pollution, recent studies have focused on co-exposures to better understand potential interactions....

Witnessing versus Experiencing Direct Violence in Childhood as Correlates of Adulthood PTSD

ERIC Educational Resources Information Center

Kulkarni, Madhur R.; Graham-Bermann, Sandra; Rauch, Sheila A. M.; Seng, Julia

2011-01-01

Research has established that childhood violence exposure plays a considerable role in the development of deleterious outcomes in childhood and adulthood. However, important gaps remain in understanding the complex relationships between early violence exposure, adulthood trauma exposure, and posttraumatic stress disorder (PTSD). This study…

[The remote effects of chronic exposure to ionizing radiation and electromagnetic fields with respect to hygienic standardization].

PubMed

Grigor'ev, Iu G; Shafirkin, A V; Nikitina, V N; Vasin, A L

2003-01-01

A variety and rate of non-cancer diseases occurred in humans as a result of chronic exposure to ionizing radiation or to electromagnetic radiation (EMR) of high and superhigh frequency have been compared. The intensity of EMR was slightly higher than a sanitary standard for population. A risk of health impairments in workers having occupational exposure to EMR was assessed on the basis of Selie's concept of development of non-specific reaction of the body to chronic stress factors (general adaptation syndrome), models of changes in the body compensatory reserves and calculations of radiation risk after severe and chronic exposure to ionizing radiation.

Development of improved wildfire smoke exposure estimates for health studies in the western U.S.

NASA Astrophysics Data System (ADS)

Ivey, C.; Holmes, H.; Loria Salazar, S. M.; Pierce, A.; Liu, C.

2016-12-01

Wildfire smoke exposure is a significant health concern in the western U.S. because large wildfires have increased in size and frequency over the past four years due to drought conditions. The transport phenomena in complex terrain and timing of the wildfire emissions make the smoke plumes difficult to simulate using conventional air quality models. Monitoring data can be used to estimate exposure metrics, but in rural areas the monitoring networks are too sparse to calculate wildfire exposure metrics for the entire population in a region. Satellite retrievals provide global, spatiotemporal air quality information and are used to track pollution plumes, estimate human exposures, model emissions, and determine sources (i.e., natural versus anthropogenic) in regulatory applications. Particulate matter (PM) exposures can be estimated using columnar aerosol optical depth (AOD), where satellite AOD retrievals serve as a spatial surrogate to simulate surface PM gradients. These exposure models have been successfully used in health effects studies in the eastern U.S. where complex mountainous terrain and surface reflectance do not limit AOD retrival from satellites. Using results from a chemical transport model (CTM) is another effective method to determine spatial gradients of pollutants. However, the CTM does not adequately capture the temporal and spatial distribution of wildfire smoke plumes. By combining the spatiotemporal pollutant fields from both satellite retrievals and CTM results with ground based pollutant observations the spatial wildfire smoke exposure model can be improved. This work will address the challenge of understanding the spatiotemporal distributions of pollutant concentrations to model human exposures of wildfire smoke in regions with complex terrain, where meteorological conditions as well as emission sources significantly influence the spatial distribution of pollutants. The focus will be on developing models to enhance exposure estimates of elevated PM and ozone concentrations from wildfire smoke plumes in the western U.S.

How students process equations in solving quantitative synthesis problems? Role of mathematical complexity in students' mathematical performance

NASA Astrophysics Data System (ADS)

Ibrahim, Bashirah; Ding, Lin; Heckler, Andrew F.; White, Daniel R.; Badeau, Ryan

2017-12-01

We examine students' mathematical performance on quantitative "synthesis problems" with varying mathematical complexity. Synthesis problems are tasks comprising multiple concepts typically taught in different chapters. Mathematical performance refers to the formulation, combination, and simplification of equations. Generally speaking, formulation and combination of equations require conceptual reasoning; simplification of equations requires manipulation of equations as computational tools. Mathematical complexity is operationally defined by the number and the type of equations to be manipulated concurrently due to the number of unknowns in each equation. We use two types of synthesis problems, namely, sequential and simultaneous tasks. Sequential synthesis tasks require a chronological application of pertinent concepts, and simultaneous synthesis tasks require a concurrent application of the pertinent concepts. A total of 179 physics major students from a second year mechanics course participated in the study. Data were collected from written tasks and individual interviews. Results show that mathematical complexity negatively influences the students' mathematical performance on both types of synthesis problems. However, for the sequential synthesis tasks, it interferes only with the students' simplification of equations. For the simultaneous synthesis tasks, mathematical complexity additionally impedes the students' formulation and combination of equations. Several reasons may explain this difference, including the students' different approaches to the two types of synthesis problems, cognitive load, and the variation of mathematical complexity within each synthesis type.

The mere exposure effect in the domain of haptics.

PubMed

Jakesch, Martina; Carbon, Claus-Christian

2012-01-01

Zajonc showed that the attitude towards stimuli that one had been previously exposed to is more positive than towards novel stimuli. This mere exposure effect (MEE) has been tested extensively using various visual stimuli. Research on the MEE is sparse, however, for other sensory modalities. We used objects of two material categories (stone and wood) and two complexity levels (simple and complex) to test the influence of exposure frequency (F0 = novel stimuli, F2 = stimuli exposed twice, F10 = stimuli exposed ten times) under two sensory modalities (haptics only and haptics & vision). Effects of exposure frequency were found for high complex stimuli with significantly increasing liking from F0 to F2 and F10, but only for the stone category. Analysis of "Need for Touch" data showed the MEE in participants with high need for touch, which suggests different sensitivity or saturation levels of MEE. This different sensitivity or saturation levels might also reflect the effects of expertise on the haptic evaluation of objects. It seems that haptic and cross-modal MEEs are influenced by factors similar to those in the visual domain indicating a common cognitive basis.

Media Exposure in Very Young Girls: Prospective and Cross-Sectional Relationships with BMIz, Self-Esteem and Body Size Stereotypes

ERIC Educational Resources Information Center

Rodgers, Rachel F.; Damiano, Stephanie R.; Wertheim, Eleanor H.; Paxton, Susan J.

2017-01-01

Media exposure among young children has been suggested to influence self-concept and the adoption of social stereotypes regarding body weight, as well as being associated with increased weight. The aim of this study was to examine the role of TV/DVD viewing in the development of positive stereotypes toward thinness, self-esteem and body mass index…

Minimizing radiation exposure during percutaneous nephrolithotomy.

PubMed

Chen, T T; Preminger, G M; Lipkin, M E

2015-12-01

Given the recent trends in growing per capita radiation dose from medical sources, there have been increasing concerns over patient radiation exposure. Patients with kidney stones undergoing percutaneous nephrolithotomy (PNL) are at particular risk for high radiation exposure. There exist several risk factors for increased radiation exposure during PNL which include high Body Mass Index, multiple access tracts, and increased stone burden. We herein review recent trends in radiation exposure, radiation exposure during PNL to both patients and urologists, and various approaches to reduce radiation exposure. We discuss incorporating the principles of As Low As reasonably Achievable (ALARA) into clinical practice and review imaging techniques such as ultrasound and air contrast to guide PNL access. Alternative surgical techniques and approaches to reducing radiation exposure, including retrograde intra-renal surgery, retrograde nephrostomy, endoscopic-guided PNL, and minimally invasive PNL, are also highlighted. It is important for urologists to be aware of these concepts and techniques when treating stone patients with PNL. The discussions outlined will assist urologists in providing patient counseling and high quality of care.

Two mothers and a donor: exploration of children's family concepts in lesbian households.

PubMed

Raes, I; Van Parys, H; Provoost, V; Buysse, A; De Sutter, P; Pennings, G

2015-01-01

Although children from lesbian families appear to make a distinction between a residential father and a donor, defining these two concepts seems to be a challenge. They need to appeal to more familiar concepts such as the hetero-normative concept of 'mother' to give a definition of the unfamiliar concepts they are confronted with. The study is based on qualitative in-depth interviews with 6 children (9-10 years old) from lesbian families, all of which have been conceived using anonymous sperm donation. Semi-structured interviews were conducted. Two findings stand out. First, in defining the concepts of biological and non-biological mother, both mothers were described as equal parents. No difference was attached by the children to the mothers' position as a parent. Second, the concepts 'non-biological mother' and 'donor' were defined by looking at the hetero-normative concepts of 'mummy' and 'daddy'. To define the non-biological mother, both a 'mummy' and a 'daddy' were used as a reference. To define the donor concept, often references were made to a daddy. This comparison with a 'daddy' turned out to be complex due to the conflict between the role as a progenitor and the lack of a social relationship. The lack of language surrounding this concept turned out to be difficult. This study illustrates the complexity and ambiguity of children's experiences and perceptions when dealing with issues related to genetic and social parenthood.

A New Look at Preservice Teachers' Conceptions of Classroom Management and Organization: Uncovering Complexity and Dissonance

ERIC Educational Resources Information Center

Kaufman, Douglas; Moss, David M.

2010-01-01

This article examines preservice teachers' conceptions of classroom management and organization in light of their training and beliefs about good teaching. Students in their final year of a 5-year program discussed their definitions and conceptions of classroom management, organization, and rule systems through an open-ended questionnaire.…

Enhancing Concept Comprehension in a Web-Based Course Using a Framework Integrating the Learning Cycle with Variation Theory

ERIC Educational Resources Information Center

Hsu, Chih-Chao; Wang, Tzone-I

2014-01-01

Concept comprehension is an important foundation for more complex thoughts. To enhance concept comprehension, teachers of traditional classrooms have been using instructional strategies and specific course designs, which have been proven effective. It initiates a hypothesis that integrating instructional strategies in the course designs of an…

Mars Rover Concept Vehicle

NASA Image and Video Library

2017-06-05

Crowds gather around the scientifically-themed Mars rover concept vehicle at the Kennedy Space Center Visitor Complex. It is a part of the "Summer of Mars" program designed to provide a survey of NASA's studies of the Red Planet. The builders of the rover, Parker Brothers Concepts of Port Canaveral, Florida, incorporated input into its design from NASA subject matter experts.

Surfacing the Structures of Patriarchy: Teaching and Learning Threshold Concepts in Women's Studies

ERIC Educational Resources Information Center

Hassel, Holly; Reddinger, Amy; van Slooten, Jessica

2011-01-01

Patriarchy is a threshold concept in women's studies--a significant, defining concept that transforms students' understanding of the discipline. This article reviews our design, implementation, and findings of a lesson study crafted to teach women's studies students the complex idea of patriarchy as a social system. We analyze the lesson using…

Changes in Geologic Time Understanding in a Class for Preservice Teachers

ERIC Educational Resources Information Center

Teed, Rebecca; Slattery, William

2011-01-01

The paradigm of geologic time is built on complex concepts, and students master it in multiple steps. Concepts in Geology is an inquiry-based geology class for preservice teachers at Wright State University. The instructors used the Geoscience Concept Inventory (GCI) to determine if students' understanding of key ideas about geologic time and…

An Experiment in Mind-Mapping and Argument-Mapping: Tools for Assessing Outcomes in the Business Curriculum

ERIC Educational Resources Information Center

Gargouri, Chanaz; Naatus, Mary Kate

2017-01-01

Distinguished from other teaching-learning tools, such as mind and concept mapping in which students draw pictures and concepts and show relationships and correlation between them to demonstrate their own understanding of complex concepts, argument mapping is used to demonstrate clarity of reasoning, based on supporting evidence, and come to a…

Use of the Concept of "Bildung" in the International Science Education Literature, Its Potential, and Implications for Teaching and Learning

ERIC Educational Resources Information Center

Sjöström, Jesper; Frerichs, Nadja; Zuin, Vânia G.; Eilks, Ingo

2017-01-01

"Bildung" is a complex educational concept that emerged in Germany in the mid eighteenth century. Especially in Germany and Scandinavia conceptions of "Bildung" became the general philosophical framework to guide both formal and informal education. "Bildung" concerns the whole range of education from setting…

Discourse, Complexity, Normativity: Tracing the Elaboration of Foucault's Materialist Concept of Discourse

ERIC Educational Resources Information Center

Olssen, Mark

2014-01-01

In this article, I want to suggest that it is through the elaboration of the concept of discourse that the differences between Foucault and thinkers like Habermas, Hegel and Marx can best be understood. Foucault progressively develops a conception of discourse as a purely historical category that resists all reference to transcendental principles…

Analysis of Discourse Accent and Discursive Practices I&W

DTIC Science & Technology

2010-09-01

events in a cultural memory. Episodic discourse encompasses general principles, concepts , symbols and rituals used by actors to address problems in...COGNITIVE/INTEGRATIVE COMPLEXITY PROOF-OF- CONCEPT ............................ 51 5.1 Historical Background and Literature...formal training or expertise in critical discourse analysis. In addition, a proof-of- concept was conducted of an existing methodology for tracking

The Identification of Threshold Concepts: A Review of Theoretical Complexities and Methodological Challenges

ERIC Educational Resources Information Center

Barradell, Sarah

2013-01-01

While the study of threshold concepts is a growing area of research, their identification has not proven to be an easy process. However, identification matters because of the potential impact of threshold concepts on the learning experiences of students. A dialogue amongst lecturers and/or students is common to the literature on identification of…

Concept analysis: malpractice and modern-day nursing practice.

PubMed

Weld, Konstantine Keian; Garmon Bibb, Sandra C

2009-01-01

The concept of malpractice can mean different things depending upon the context in which the term is used. This can lead to confusion about the standard of care required for nurses engaged in modern-day nursing practice. This paper examines the attributes and characteristics of the concept of malpractice using Walker and Avant's (2005) eight-step methodology. CINAHL, PubMed, and PsychINFO. Exposure to malpractice liability is an unfortunate consequence of modern-day nursing practice. An understanding of malpractice will assist nurses in identifying situations that may expose them to legal liability and hopefully lead to improved patient care.

Placental 11 β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) expression very early during human pregnancy.

PubMed

Salvante, K G; Milano, K; Kliman, H J; Nepomnaschy, P A

2017-04-01

Maternal physiologic stress during gestation has been reported to be associated with negative developmental outcomes, including intra-uterine growth restriction and reduced birth weight, which can impact postnatal development, behavior and health. The human fetus is partially protected from elevated cortisol exposure by placental 11 β-hydroxysteroid dehydrogenase type 2 (11β-HSD2), which oxidizes bioactive cortisol into bio-inactive cortisone. Importantly, despite the critical protective role hypothesized for 11β-HSD2, the onset of its placental expression has yet to be clearly established. To this aim, we present immunocytochemical analysis of placentas collected 3-6 weeks post-conception. 11β-HSD2 was present as early as 3 weeks post-conception in syncytiotrophoblasts, where most maternal-fetal exchange occurs, and in columnar epithelial cells encircling uterine endometrial glands, which provide early histiopathic nutrition to the embryo. 11β-HSD2 expression in these critical maternal-fetal exchange areas is consistent with its hypothesized protective role. Future studies should investigate the mechanisms that may modulate embryonic glucocorticoid exposure earlier, immediately post-conception.

Shifting conceptions of complexity in forest management and silviculture

Treesearch

Robert T. Fahey; Brandon C. Alveshere; Julia I. Burton; Anthony W. D' Amato; Yvette L. Dickinson; William S. Keeton; Christel C. Kern; Andrew J. Larson; Brian J. Palik; Klaus J. Puettmann; Michael R. Saunders; Christopher R. Webster; Jeff W. Atkins; Christopher M. Gough; Brady S. Hardiman

2018-01-01

In the past several decades, a trend in forestry and silviculture has been toward promoting complexity in forest ecosystems, but how complexity is conceived and described has shifted over time as new ideas and terminology have been introduced. Historically, ecologically-focused silviculture has focused largely on manipulation of structural complexity, but often with...

C.A.D. and ergonomic workstations conception

NASA Astrophysics Data System (ADS)

Keravel, Francine

1986-07-01

Computer Aided Design is able to perform workstation's conception. An ergonomic data could be complete this view and warrant a coherent fiability conception. Complexe form representation machines, anthropometric data and environment factors are allowed to perceive the limit points between humain and new technology situation. Work ability users, safety, confort and human efficiency could be also included. Such a programm with expert system integration will give a complete listing appreciation about workstation's conception.

Homeostatis and Complexity as Integrating Tools in Gerontological Education.

ERIC Educational Resources Information Center

Richardson, Daniel; McCulloch, B. Jan; Rowles, Graham D.

2001-01-01

A gerontology doctoral program used the concepts of homeostasis and complexity to present biomedical and psychosocial issues. Data from 14 students showed that homeostasis was more useful for biomedical than psychosocial issues. Complexity helped in understanding interactions between the two. (SK)

Expanding application of the Wiggers diagram to teach cardiovascular physiology

PubMed Central

Wang, Jiun-Jr

2014-01-01

Dr. Carl Wiggers' careful observations have provided a meaningful resource for students to learn how the heart works. Throughout the many years from his initial reports, the Wiggers diagram has been used, in various degrees of complexity, as a fundamental tool for cardiovascular instruction. Often, the various electrical and mechanical plots are the novice learner's first exposure to simulated data. As the various temporal relationships throughout a heartbeat could simply be memorized, the challenge for the cardiovascular instructor is to engage the learner so the underlying mechanisms governing the changing electrical and mechanical events are truly understood. Based on experience, we suggest some additions to the Wiggers diagram that are not commonly used to enhance cardiovascular pedagogy. For example, these additions could be, but are not limited to, introducing the concept of energy waves and their role in influencing pressure and flow in health and disease. Also, integrating concepts of exercise physiology, and the differences in cardiac function and hemodynamics between an elite athlete and normal subject, can have a profound impact on student engagement. In describing the relationship between electrical and mechanical events, the instructor may find the introduction of premature ventricular contractions as a useful tool to further understanding of this important principle. It is our hope that these examples can aid cardiovascular instructors to engage their learners and promote fundamental understanding at the expense of simple memorization. PMID:24913453

Expanding application of the Wiggers diagram to teach cardiovascular physiology.

PubMed

Mitchell, Jamie R; Wang, Jiun-Jr

2014-06-01

Dr. Carl Wiggers' careful observations have provided a meaningful resource for students to learn how the heart works. Throughout the many years from his initial reports, the Wiggers diagram has been used, in various degrees of complexity, as a fundamental tool for cardiovascular instruction. Often, the various electrical and mechanical plots are the novice learner's first exposure to simulated data. As the various temporal relationships throughout a heartbeat could simply be memorized, the challenge for the cardiovascular instructor is to engage the learner so the underlying mechanisms governing the changing electrical and mechanical events are truly understood. Based on experience, we suggest some additions to the Wiggers diagram that are not commonly used to enhance cardiovascular pedagogy. For example, these additions could be, but are not limited to, introducing the concept of energy waves and their role in influencing pressure and flow in health and disease. Also, integrating concepts of exercise physiology, and the differences in cardiac function and hemodynamics between an elite athlete and normal subject, can have a profound impact on student engagement. In describing the relationship between electrical and mechanical events, the instructor may find the introduction of premature ventricular contractions as a useful tool to further understanding of this important principle. It is our hope that these examples can aid cardiovascular instructors to engage their learners and promote fundamental understanding at the expense of simple memorization. Copyright © 2014 The American Physiological Society.

Bruising Hands and Arms

MedlinePlus

... due to the weakened state of blood vessel walls from many years of sun exposure. Blood thinners, ... Spring Current Concepts in Dermatology 2902 North Baltimore Street | P.O. Box 7525 | Kirksville, Missouri 63501 660- ...

Children's understanding of the immune system: Integrating the cognitive-developmental and intuitive theories' perspectives

NASA Astrophysics Data System (ADS)

Landry-Boozer, Kristine L.

Traditional cognitive-developmental researchers have provided a large body of evidence supporting the stage-like progression of children's cognitive development. Further, from this body of research comes evidence that children's understanding of HIV/AIDS develops in much the same way as their understanding of other illness-related concepts. Researchers from a newer perspective assert that biological concepts develop from intuitive theories. In general, as children are exposed to relevant content and have opportunities to organize this information, their theories become more accurate and differentiated. According to this perspective, there are no broad structural constraints on developing concepts, as asserted by cognitive developmental theorists. The purpose of the current study was two-fold: to provide support for both theoretical perspectives, while at the same time to explore children's conceptualizations of the immune system, which has not been done previously in the cognitive-developmental literature. One hundred ninety children ranging in age from 4 years old through 11 years old, and a group of adults, participated. Each participant was interviewed regarding health concepts and the body's function in maintaining health. Participants were also asked to report if they had certain experiences that would have led to relevant content exposure. Qualitative analyses were utilized to code the interviews with rubrics based on both theoretical perspectives. Quantitative analyses consisted of a series of univariate ANOVAs (and post hoc tests when appropriate) examining all three coding variables (accuracy, differentiation, and developmental level) across various age-group combinations and exposure groups. Results of these analyses provided support for both theoretical perspectives. When the data were analyzed for developmental level by all ages, a stage-like progression consistent with Piagetian stages emerged. When accuracy and differentiation were examined (intuitive theories perspective), discrete groups could not be formed. Instead, a gradual increase in accuracy and differentiation was observed. Additional support for this perspective was found when the responses of participants who had additional exposure provided responses that were more accurate, differentiated, and sophisticated than those of participants with no additional exposure. Theoretical and educational implications of these findings are discussed.

UV-LIGA technique for ECF micropumps using back UV exposure and self-alignment

NASA Astrophysics Data System (ADS)

Han, D.; Xia, Y.; Yokota, S.; Kim, J. W.

2017-12-01

This paper proposes and develops a novel UV-LIGA technique using back UV exposure and self-alignment to realize high aspect ratio micromachining (HARM) in high power density electro-conjugate fluid (ECF) micropumps. ECF is a functional fluid designed to be able to generate strong and active jet flow (ECF jetting) between anode and cathode in ECF when high DC voltage is applied. We have developed high power density ECF micropumps consisting of triangular prism and slit electrode pairs (TPSEs) fabricated by HARM. The traditional UV-LIGA technique for HARM is mainly divided into two approaches: (a) single thick layer and (b) multiple thin layers. Both methods have limitations—deformed molds in the former and misalignment between layers in the latter. Using the finite element method software COMSOL Multiphysics, we demonstrate that the deformed micro-molds critically impair the performance of ECF micropumps. In addition, we experimentally prove that the misalignment would easily trigger electric discharge in the ECF micropumps. To overcome these limitations, we conceive a new concept utilizing the seed electrode layer for electroforming as the UV shield and pattern photoresist (KMPR) by back UV exposure. The seed electrode layer should be composed of a non-transparent conductor (Au/Ti) for patterning and a transparent conductor (ITO) for wiring. Instead of ITO, we propose the concept of transparency-like electrodes comprised of thin metal line patterns. To verify this concept, KMPR layers with thicknesses of 70, 220, and 500 µm are experimentally investigated. In the case of 500 µm KMPR thickness, the concept of transparency-like electrode was partially proved. As a result, TPSEs with a height of 440 µm were successfully fabricated. Characteristic experiments demonstrated that ECF micropumps (367 mW cm-3) fabricated by back UV achieved almost the same output power density as ECF micropumps (391 mW cm-3) fabricated by front UV. This paper proves that the proposed UV-LIGA technique, using back UV exposure and self-alignment, can effectively fabricate TPSEs for ECF micropumps with high output power density.

Understanding environmental contributions to autism: Causal concepts and the state of science.

PubMed

Hertz-Picciotto, Irva; Schmidt, Rebecca J; Krakowiak, Paula

2018-04-01

The complexity of neurodevelopment, the rapidity of early neurogenesis, and over 100 years of research identifying environmental influences on neurodevelopment serve as backdrop to understanding factors that influence risk and severity of autism spectrum disorder (ASD). This Keynote Lecture, delivered at the May 2016 annual meeting of the International Society for Autism Research, describes concepts of causation, outlines the trajectory of research on nongenetic factors beginning in the 1960s, and briefly reviews the current state of this science. Causal concepts are introduced, including root causes; pitfalls in interpreting time trends as clues to etiologic factors; susceptible time windows for exposure; and implications of a multi-factorial model of ASD. An historical background presents early research into the origins of ASD. The epidemiologic literature from the last fifteen years is briefly but critically reviewed for potential roles of, for example, air pollution, pesticides, plastics, prenatal vitamins, lifestyle and family factors, and maternal obstetric and metabolic conditions during her pregnancy. Three examples from the case-control CHildhood Autism Risks from Genes and the Environment Study are probed to illustrate methodological approaches to central challenges in observational studies: capturing environmental exposure; causal inference when a randomized controlled clinical trial is either unethical or infeasible; and the integration of genetic, epigenetic, and environmental influences on development. We conclude with reflections on future directions, including exposomics, new technologies, the microbiome, gene-by-environment interaction in the era of -omics, and epigenetics as the interface of those two. As the environment is malleable, this research advances the goal of a productive and fulfilling life for all children, teen-agers and adults. Autism Res 2018, 11: 554-586. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. This Keynote Lecture, delivered at the 2016 meeting of the International Society for Autism Research, discusses evidence from human epidemiologic studies of prenatal factors contributing to autism, such as pesticides, maternal nutrition and her health. There is no single cause for autism. Examples highlight the features of a high-quality epidemiology study, and what comprises a compelling case for causation. Emergent research directions hold promise for identifying potential interventions to reduce disabilities, enhance giftedness, and improve lives of those with ASD. © 2018 International Society for Autism Research, Wiley Periodicals, Inc.

Ultraviolet-B radiation mobilizes uranium from uranium-dissolved organic carbon complexes in aquatic systems, demonstrated by asymmetrical flow field-flow fractionation.

PubMed

Nehete, Sachin Vilas; Christensen, Terje; Salbu, Brit; Teien, Hans-Christian

2017-05-05

Humic substances have a tendency to form complexes with metal ions in aquatic medium, impacting the metal mobility, decreasing bioavailability and toxicity. Ultraviolet-B (UV-B) radiation exposure degrades the humic substance, changes their molecular weight distribution and their metal binding capacity in aquatic medium. In this study, we experimented the effect of UV-B radiation on the uranium complexed with fulvic acids and humic acids in a soft water system at different pH, uranium concentrations and radiant exposure. The concentration and distribution of uranium in a complexed form were investigated by asymmetrical flow field-flow fractionation coupled to multi detection technique (AsFlFFF-UV-ICP-MS). The major concentration of uranium present in complexes was primarily associated with average and higher molecular weight fulvic and humic acids components. The concentration of uranium in a complexed form increased with increasing fulvic and humic acid concentrations as well as pH of the solution. The higher molecular weight fraction of uranium was degraded due to the UV-B exposure, transforming about 50% of the uranium-dissolved organic carbon complexes into low molecular weight uranium species in complex form with organic ligands and/or free form. The result also suggests AsFlFFF-UV-ICP-MS to be an important separation and detection technique for understanding the interaction of radionuclides with dissolved organic matter, tracking size distribution changes during degradation of organic complexes for understanding mobility, bioavailability and ecosystem transfer of radionuclides as well as metals. Copyright © 2017 Elsevier B.V. All rights reserved.

Prenatal Alcohol Exposure and Cellular Differentiation

PubMed Central

Veazey, Kylee J.; Muller, Daria; Golding, Michael C.

2013-01-01

Exposure to alcohol significantly alters the developmental trajectory of progenitor cells and fundamentally compromises tissue formation (i.e., histogenesis). Emerging research suggests that ethanol can impair mammalian development by interfering with the execution of molecular programs governing differentiation. For example, ethanol exposure disrupts cellular migration, changes cell–cell interactions, and alters growth factor signaling pathways. Additionally, ethanol can alter epigenetic mechanisms controlling gene expression. Normally, lineage-specific regulatory factors (i.e., transcription factors) establish the transcriptional networks of each new cell type; the cell’s identity then is maintained through epigenetic alterations in the way in which the DNA encoding each gene becomes packaged within the chromatin. Ethanol exposure can induce epigenetic changes that do not induce genetic mutations but nonetheless alter the course of fetal development and result in a large array of patterning defects. Two crucial enzyme complexes—the Polycomb and Trithorax proteins—are central to the epigenetic programs controlling the intricate balance between self-renewal and the execution of cellular differentiation, with diametrically opposed functions. Prenatal ethanol exposure may disrupt the functions of these two enzyme complexes, altering a crucial aspect of mammalian differentiation. Characterizing the involvement of Polycomb and Trithorax group complexes in the etiology of fetal alcohol spectrum disorders will undoubtedly enhance understanding of the role that epigenetic programming plays in this complex disorder. PMID:24313167

Advancing Porous Silicon Biosensor Technology for Use in Clinical Diagnostics

NASA Astrophysics Data System (ADS)

Bonanno, Lisa Marie

Inexpensive and robust analytical techniques for detecting molecular recognition events are in great demand in healthcare, food safety, and environmental monitoring. Despite vast research in this area, challanges remain to develop practical biomolecular platforms that, meet the rigorous demands of real-world applications. This includes maintaining low-cost devices that are sensitive and specific in complex test specimens, are stable after storage, have short assay time, and possess minimal complexity of instrumentation for readout. Nanostructured porous silicon (PSi) material has been identified as an ideal candidate towards achieving these goals and the past decade has seen diverse proof-of-principle studies developing optical-based sensing techniques. In Part 1 of this thesis, the impact of surface chemistry and PSi morphology on detection sensitivity of target molecules is investigated. Initial proof-of-concept that PSi devices facilitate detection of protein in whole blood is demonstrated. This work highlights the importance of material stability and blocking chemistry for sensor use in real world biological samples. In addition, the intrinisic filtering capability of the 3-D PSi morphology is shown as an advantage in complex solutions, such as whole blood. Ultimately, this initial work identified a need to improve detection sensitivity of the PSI biosensor technique to facilitate clinical diagnostic use over relevant target concentration ranges. The second part of this thesis, builds upon sensitivity challenges that are highlighted in the first part of the thesis and development of a surface-bound competitive inhibition immunoassay facilitated improved detection sensitivity of small molecular weight targets (opiates) over a relevant clinical concentration range. In addition, optimization of assay protocol addressed issues of maintaining stability of sensors after storage. Performance of the developed assay (specificity and sensitivity) was then validated in a blind clinical study that screened real patient urine samples (n=70) for opiates in collaboration with Strong Memorial Hospital Clinical Toxicology Laboratory. PSI sensor results showed improved clinical specificity over current commercial opiate immunoassay techniques and therefore, identified potential for a reduction in false-negative and false-positive screening results. Here, we demonstrate for the first time, successful clinical capability of a PSi sensor to detect opiates as a model target in real-world patient samples. The final part of this thesis explores novel sensor designs to leverage the tunable optical properties of PSi photonic devices and facilitate colorimetric readout of molecular recognition events by the unaided eye. Such a design is ideal for uncomplicated diagnostic screening at point-of-care as no instrumentation is needed for result readout. The photonic PSi transducers were integrated with target analyte-responsive hydrogels (TRAP-gels) that upon exposure to a target solution would swell and dissolute, inducing material property changes that were optically detected by the incorporated PSi transducer. This strategy extends target detection throughout the 3-ll internal volume of the PSi, improving upon current techniques that limit detection to the surface area (2-ll) of PSi. Work to acheive this approach involved design of TRAP-gel networks, polymer synthesis and characterization techniques, and optical characterization of the hybrid hydrogel-PSi material sensor. Successful implementation of a hybrid sensor design was exhibited for a. model chemical target (reducing agent), in which visual colorimetric change from red to green was observed for above-threshold exposure to the chemical target. In addition, initial proof-of-concept of an opiate responsive TRAP-gel is also demonstrated where cross-links are formed between antibody-antigen interactions and exposure to opiates induces bulk gel dissolution.

Habitat Design Considerations for Implementing Solar Particle Event Radiation Protection

NASA Technical Reports Server (NTRS)

Simon, Mathew A.; Clowdsley, Martha S.; Walker, Steven A.

2013-01-01

Radiation protection is an important habitat design consideration for human exploration missions beyond Low Earth Orbit. Fortunately, radiation shelter concepts can effectively reduce astronaut exposure for the relatively low proton energies of solar particle events, enabling moderate duration missions of several months before astronaut exposure (galactic cosmic ray and solar particle event) approaches radiation exposure limits. In order to minimize habitat mass for increasingly challenging missions, design of radiation shelters must minimize dedicated, single-purpose shielding mass by leveraging the design and placement of habitat subsystems, accommodations, and consumables. NASA's Advanced Exploration Systems RadWorks Storm Shelter Team has recently designed and performed radiation analysis on several low dedicated mass shelter concepts for a year-long mission. This paper describes habitat design considerations identified during the study's radiation analysis. These considerations include placement of the shelter within a habitat for improved protection, integration of human factors guidance for sizing shelters, identification of potential opportunities for habitat subsystems to compromise on individual subsystem performances for overall vehicle mass reductions, and pre-configuration of shelter components for reduced deployment times.

Intra‐Target Microdosing – A Novel Drug Development Approach: Proof of Concept, Safety, and Feasibility Study in Humans

PubMed Central

MacLeod, D; Lee, K; Santoro, A; DeMasi, DK; Hawk, T; Feinglos, M; Rowland, M; Noveck, RJ

2017-01-01

Abstract Intra‐Target Microdosing (ITM) is a novel drug development approach aimed at increasing the efficiency of first‐in‐human (FIH) testing of new molecular entities (NMEs). ITM combines intra‐target drug delivery and “microdosing,” the subpharmacological systemic exposure. We hypothesized that when the target tissue is small (about 1/100th of total body mass), ITM can lead to target therapeutic‐level exposure with minimal (microdose) systemic exposure. Each of five healthy male volunteers received insulin microdose into the radial artery or full therapeutic dose intravenously in separate visits. Insulin and glucose levels were similar between systemic administration and ITM administration in the ipsilateral hand, and glucose levels demonstrated a reduction in the ipsilateral hand but not in the contralateral hand. Positron emission tomography (PET) imaging of 18F‐fluorodeoxyglucose (FDG) uptake demonstrated differences between the ipsilateral and contralateral arms. The procedures were safe and well‐tolerated. Results are consistent with ITM proof‐of‐concept (POC) and demonstrate the ethical, regulatory, and logistical feasibility of the approach. PMID:28689370

A Chemical Engineer's Perspective on Health and Disease

PubMed Central

Androulakis, Ioannis P.

2014-01-01

Chemical process systems engineering considers complex supply chains which are coupled networks of dynamically interacting systems. The quest to optimize the supply chain while meeting robustness and flexibility constraints in the face of ever changing environments necessitated the development of theoretical and computational tools for the analysis, synthesis and design of such complex engineered architectures. However, it was realized early on that optimality is a complex characteristic required to achieve proper balance between multiple, often competing, objectives. As we begin to unravel life's intricate complexities, we realize that that living systems share similar structural and dynamic characteristics; hence much can be learned about biological complexity from engineered systems. In this article, we draw analogies between concepts in process systems engineering and conceptual models of health and disease; establish connections between these concepts and physiologic modeling; and describe how these mirror onto the physiological counterparts of engineered systems. PMID:25506103

Evaluating biomarkers to model cancer risk post cosmic ray exposure

PubMed Central

Sridhara, Deepa M.; Asaithamby, Aroumougame; Blattnig, Steve R.; Costes, Sylvain V.; Doetsch, Paul W.; Dynan, William S.; Hahnfeldt, Philip; Hlatky, Lynn; Kidane, Yared; Kronenberg, Amy; Naidu, Mamta D.; Peterson, Leif E.; Plante, Ianik; Ponomarev, Artem L.; Saha, Janapriya; Snijders, Antoine M.; Srinivasan, Kalayarasan; Tang, Jonathan; Werner, Erica; Pluth, Janice M.

2017-01-01

Robust predictive models are essential to manage the risk of radiation-induced carcinogenesis. Chronic exposure to cosmic rays in the context of the complex deep space environment may place astronauts at high cancer risk. To estimate this risk, it is critical to understand how radiation-induced cellular stress impacts cell fate decisions and how this in turn alters the risk of carcinogenesis. Exposure to the heavy ion component of cosmic rays triggers a multitude of cellular changes, depending on the rate of exposure, the type of damage incurred and individual susceptibility. Heterogeneity in dose, dose rate, radiation quality, energy and particle flux contribute to the complexity of risk assessment. To unravel the impact of each of these factors, it is critical to identify sensitive biomarkers that can serve as inputs for robust modeling of individual risk of cancer or other long-term health consequences of exposure. Limitations in sensitivity of biomarkers to dose and dose rate, and the complexity of longitudinal monitoring, are some of the factors that increase uncertainties in the output from risk prediction models. Here, we critically evaluate candidate early and late biomarkers of radiation exposure and discuss their usefulness in predicting cell fate decisions. Some of the biomarkers we have reviewed include complex clustered DNA damage, persistent DNA repair foci, reactive oxygen species, chromosome aberrations and inflammation. Other biomarkers discussed, often assayed for at longer points post exposure, include mutations, chromosome aberrations, reactive oxygen species and telomere length changes. We discuss the relationship of biomarkers to different potential cell fates, including proliferation, apoptosis, senescence, and loss of stemness, which can propagate genomic instability and alter tissue composition and the underlying mRNA signatures that contribute to cell fate decisions. Our goal is to highlight factors that are important in choosing biomarkers and to evaluate the potential for biomarkers to inform models of post exposure cancer risk. Because cellular stress response pathways to space radiation and environmental carcinogens share common nodes, biomarker-driven risk models may be broadly applicable for estimating risks for other carcinogens. PMID:27345199

Evaluating biomarkers to model cancer risk post cosmic ray exposure

NASA Astrophysics Data System (ADS)

Sridharan, Deepa M.; Asaithamby, Aroumougame; Blattnig, Steve R.; Costes, Sylvain V.; Doetsch, Paul W.; Dynan, William S.; Hahnfeldt, Philip; Hlatky, Lynn; Kidane, Yared; Kronenberg, Amy; Naidu, Mamta D.; Peterson, Leif E.; Plante, Ianik; Ponomarev, Artem L.; Saha, Janapriya; Snijders, Antoine M.; Srinivasan, Kalayarasan; Tang, Jonathan; Werner, Erica; Pluth, Janice M.

2016-06-01

Robust predictive models are essential to manage the risk of radiation-induced carcinogenesis. Chronic exposure to cosmic rays in the context of the complex deep space environment may place astronauts at high cancer risk. To estimate this risk, it is critical to understand how radiation-induced cellular stress impacts cell fate decisions and how this in turn alters the risk of carcinogenesis. Exposure to the heavy ion component of cosmic rays triggers a multitude of cellular changes, depending on the rate of exposure, the type of damage incurred and individual susceptibility. Heterogeneity in dose, dose rate, radiation quality, energy and particle flux contribute to the complexity of risk assessment. To unravel the impact of each of these factors, it is critical to identify sensitive biomarkers that can serve as inputs for robust modeling of individual risk of cancer or other long-term health consequences of exposure. Limitations in sensitivity of biomarkers to dose and dose rate, and the complexity of longitudinal monitoring, are some of the factors that increase uncertainties in the output from risk prediction models. Here, we critically evaluate candidate early and late biomarkers of radiation exposure and discuss their usefulness in predicting cell fate decisions. Some of the biomarkers we have reviewed include complex clustered DNA damage, persistent DNA repair foci, reactive oxygen species, chromosome aberrations and inflammation. Other biomarkers discussed, often assayed for at longer points post exposure, include mutations, chromosome aberrations, reactive oxygen species and telomere length changes. We discuss the relationship of biomarkers to different potential cell fates, including proliferation, apoptosis, senescence, and loss of stemness, which can propagate genomic instability and alter tissue composition and the underlying mRNA signatures that contribute to cell fate decisions. Our goal is to highlight factors that are important in choosing biomarkers and to evaluate the potential for biomarkers to inform models of post exposure cancer risk. Because cellular stress response pathways to space radiation and environmental carcinogens share common nodes, biomarker-driven risk models may be broadly applicable for estimating risks for other carcinogens.

Evaluating biomarkers to model cancer risk post cosmic ray exposure.

PubMed

Sridharan, Deepa M; Asaithamby, Aroumougame; Blattnig, Steve R; Costes, Sylvain V; Doetsch, Paul W; Dynan, William S; Hahnfeldt, Philip; Hlatky, Lynn; Kidane, Yared; Kronenberg, Amy; Naidu, Mamta D; Peterson, Leif E; Plante, Ianik; Ponomarev, Artem L; Saha, Janapriya; Snijders, Antoine M; Srinivasan, Kalayarasan; Tang, Jonathan; Werner, Erica; Pluth, Janice M

2016-06-01

Robust predictive models are essential to manage the risk of radiation-induced carcinogenesis. Chronic exposure to cosmic rays in the context of the complex deep space environment may place astronauts at high cancer risk. To estimate this risk, it is critical to understand how radiation-induced cellular stress impacts cell fate decisions and how this in turn alters the risk of carcinogenesis. Exposure to the heavy ion component of cosmic rays triggers a multitude of cellular changes, depending on the rate of exposure, the type of damage incurred and individual susceptibility. Heterogeneity in dose, dose rate, radiation quality, energy and particle flux contribute to the complexity of risk assessment. To unravel the impact of each of these factors, it is critical to identify sensitive biomarkers that can serve as inputs for robust modeling of individual risk of cancer or other long-term health consequences of exposure. Limitations in sensitivity of biomarkers to dose and dose rate, and the complexity of longitudinal monitoring, are some of the factors that increase uncertainties in the output from risk prediction models. Here, we critically evaluate candidate early and late biomarkers of radiation exposure and discuss their usefulness in predicting cell fate decisions. Some of the biomarkers we have reviewed include complex clustered DNA damage, persistent DNA repair foci, reactive oxygen species, chromosome aberrations and inflammation. Other biomarkers discussed, often assayed for at longer points post exposure, include mutations, chromosome aberrations, reactive oxygen species and telomere length changes. We discuss the relationship of biomarkers to different potential cell fates, including proliferation, apoptosis, senescence, and loss of stemness, which can propagate genomic instability and alter tissue composition and the underlying mRNA signatures that contribute to cell fate decisions. Our goal is to highlight factors that are important in choosing biomarkers and to evaluate the potential for biomarkers to inform models of post exposure cancer risk. Because cellular stress response pathways to space radiation and environmental carcinogens share common nodes, biomarker-driven risk models may be broadly applicable for estimating risks for other carcinogens. Copyright © 2016 The Committee on Space Research (COSPAR). All rights reserved.

Complexity Analysis of Traffic in Corridors-in-the-Sky

NASA Technical Reports Server (NTRS)

Xue, Min; Zelinski, Shannon Jean

2010-01-01

The corridors-in-the-sky concept imitates the highway system in ground transportation. The benefit expected from a corridor relies on its capability of handling high density traffic with negligible controller workload, the acceptance of extra fuel or distance, and the complexity reduction in underlying sectors. This work evaluates a selected corridor from these perspectives through simulations. To examine traffic inside the corridor, a corridor traffic simulation tool that can resolve conflicts is developed using C language. Prescribed conflict resolution maneuvers mimic corridor users behaviors and conflict resolution counts measure complexity. Different lane options and operational policies are proposed to examine their impacts on complexity. Fuel consumption is calculated and compared for corridor traffic. On the other hand, to investigate the complexity of non-corridor traffic in underlying sectors, the existing Airspace Concept Evaluation System tool is utilized along with the Automated Airspace Concept tool. The number of conflict resolutions is examined and treated as the complexity measurement. The results show heavy traffic can be managed with low complexity for a historical traffic schedule simulated with appropriate operational policies and lane options. For instance, with 608 flights and peak aircraft count of 100, only 84 actions need to be taken in a 24-hour period to resolve the conflicts for an 8-lane corridor. Compared with the fuel consumptions with great circle trajectories, the simulation of corridor traffic shows that the total extra fuel for corridor flights is 26,373 gallons, or 2.76%, which is 0.38% less than flying filed flight plans. Without taking climb and descent portions of corridor traffic, the complexity of underlying sectors is reduced by 17.71%. However the climb and descent portions will eliminate the reduction and the overall complexity of sectors is actually increased by 9.14%.

Cumulative trauma and symptom complexity in children: a path analysis.

PubMed

Hodges, Monica; Godbout, Natacha; Briere, John; Lanktree, Cheryl; Gilbert, Alicia; Kletzka, Nicole Taylor

2013-11-01

Multiple trauma exposures during childhood are associated with a range of psychological symptoms later in life. In this study, we examined whether the total number of different types of trauma experienced by children (cumulative trauma) is associated with the complexity of their subsequent symptomatology, where complexity is defined as the number of different symptom clusters simultaneously elevated into the clinical range. Children's symptoms in six different trauma-related areas (e.g., depression, anger, posttraumatic stress) were reported both by child clients and their caretakers in a clinical sample of 318 children. Path analysis revealed that accumulated exposure to multiple different trauma types predicts symptom complexity as reported by both children and their caretakers. Copyright © 2013 Elsevier Ltd. All rights reserved.

Systems medicine: a new approach to clinical practice.

PubMed

Cardinal-Fernández, Pablo; Nin, Nicolás; Ruíz-Cabello, Jesús; Lorente, José A

2014-10-01

Most respiratory diseases are considered complex diseases as their susceptibility and outcomes are determined by the interaction between host-dependent factors (genetic factors, comorbidities, etc.) and environmental factors (exposure to microorganisms or allergens, treatments received, etc.) The reductionist approach in the study of diseases has been of fundamental importance for the understanding of the different components of a system. Systems biology or systems medicine is a complementary approach aimed at analyzing the interactions between the different components within one organizational level (genome, transcriptome, proteome), and then between the different levels. Systems medicine is currently used for the interpretation and understanding of the pathogenesis and pathophysiology of different diseases, biomarker discovery, design of innovative therapeutic targets, and the drawing up of computational models for different biological processes. In this review we discuss the most relevant concepts of the theory underlying systems medicine, as well as its applications in the various biological processes in humans. Copyright © 2013 SEPAR. Published by Elsevier Espana. All rights reserved.

High wettability of liquid caesium iodine with solid uranium dioxide.

PubMed

Kurosaki, Ken; Suzuki, Masanori; Uno, Masayoshi; Ishii, Hiroto; Kumagai, Masaya; Anada, Keito; Murakami, Yukihiro; Ohishi, Yuji; Muta, Hiroaki; Tanaka, Toshihiro; Yamanaka, Shinsuke

2017-09-13

In March 2011, the Fukushima Daiichi Nuclear Power Plant accident caused nuclear fuel to melt and the release of high-volatility fission products into the environment. Caesium and iodine caused environmental contamination and public exposure. Certain fission-product behaviours remain unclear. We found experimentally that liquid CsI disperses extremely favourably toward solid UO 2 , exhibiting a contact angle approaching zero. We further observed the presence of CsI several tens of micrometres below the surface of the solid UO 2 sample, which would be caused by the infiltration of pores network by liquid CsI. Thus, volatile fission products released from molten nuclear fuels with complex internal composition and external structure migrate or evaporate to varying extents, depending on the nature of the solid-liquid interface and the fuel material surface, which becomes the pathway for the released fission products. Introducing the concept of the wettability of liquid chemical species of fission products in contact with solid fuels enabled developing accurate behavioural assessments of volatile fission products released by nuclear fuel.

Order Matters: Sequencing Scale-Realistic Versus Simplified Models to Improve Science Learning

NASA Astrophysics Data System (ADS)

Chen, Chen; Schneps, Matthew H.; Sonnert, Gerhard

2016-10-01

Teachers choosing between different models to facilitate students' understanding of an abstract system must decide whether to adopt a model that is simplified and striking or one that is realistic and complex. Only recently have instructional technologies enabled teachers and learners to change presentations swiftly and to provide for learning based on multiple models, thus giving rise to questions about the order of presentation. Using disjoint individual growth modeling to examine the learning of astronomical concepts using a simulation of the solar system on tablets for 152 high school students (age 15), the authors detect both a model effect and an order effect in the use of the Orrery, a simplified model that exaggerates the scale relationships, and the True-to-scale, a proportional model that more accurately represents the realistic scale relationships. Specifically, earlier exposure to the simplified model resulted in diminution of the conceptual gain from the subsequent realistic model, but the realistic model did not impede learning from the following simplified model.

Innovative Use of Service-Learning to Enhance Baccalaureate Nursing Education.

PubMed

Taylor, Wanda; Pruitt, Rosanne; Fasolino, Tracy

2017-09-01

Service-learning is an established pedagogical approach to nursing education found primarily in community nursing. With changing health care landscapes, the expansion of service-learning projects throughout the nursing program provides opportunities to enrich assessment and critical thinking and amplify exposure to determinants of health. Implementing service-learning in foundational nursing courses allows students to be challenged with the application of complex care management within a context of caring, cultural competence, social responsibility, and self-care initiatives. Integrating service-learning throughout the nursing curriculum has the potential to make positive, sustainable changes within a community, while simultaneously preparing students to view clients holistically, think critically, and develop cultural competence. Enhancing nursing curriculum by integrating service-learning opportunities can strengthen the learning experience and foster concepts of caring, social responsibility, cultural competence, and self-care. Working with community leaders from diverse groups can lead to sustainable projects that simultaneously benefit the community and nursing education. [J Nurs Educ. 2017;56(9):560-563.]. Copyright 2017, SLACK Incorporated.

A Dimensional Bus model for integrating clinical and research data.

PubMed

Wade, Ted D; Hum, Richard C; Murphy, James R

2011-12-01

Many clinical research data integration platforms rely on the Entity-Attribute-Value model because of its flexibility, even though it presents problems in query formulation and execution time. The authors sought more balance in these traits. Borrowing concepts from Entity-Attribute-Value and from enterprise data warehousing, the authors designed an alternative called the Dimensional Bus model and used it to integrate electronic medical record, sponsored study, and biorepository data. Each type of observational collection has its own table, and the structure of these tables varies to suit the source data. The observational tables are linked to the Bus, which holds provenance information and links to various classificatory dimensions that amplify the meaning of the data or facilitate its query and exposure management. The authors implemented a Bus-based clinical research data repository with a query system that flexibly manages data access and confidentiality, facilitates catalog search, and readily formulates and compiles complex queries. The design provides a workable way to manage and query mixed schemas in a data warehouse.

Behavioral responses of juvenile Daphnia magna after exposure to glyphosate and glyphosate-copper complexes.

PubMed

Hansen, Lone Rykær; Roslev, Peter

2016-10-01

Glyphosate (N-(phosphonomethyl)glycine) is the active ingredient in a range of popular broad-spectrum herbicide formulations. Glyphosate is a chelating agent that can form stable complexes with divalent metal ions including Cu(II). Little is known about the bioavailability and ecotoxicity of glyphosate-Cu(II) complexes to aquatic organisms. In this study, we used video tracking and behavior analysis to investigate sublethal effects of binary mixtures of glyphosate and Cu(II) to juvenile D. magna. Behavioral responses were quantified for individual D. magna after 24h and 48h exposure to glyphosate and glyhosate-Cu(II) mixtures. Sublethal concentrations resulted in decreases in swimming velocity, acceleration speed, and distance moved whereas inactive time of D. magna increased. Distance moved and inactive time were the most responsive parameters to glyphosate and glyphosate-Cu(II) exposure. On a molar basis, glyphosate-Cu(II) complexes appeared more toxic to D. magna than glyphosate alone. The 48h EC50 for glyphosate and glyphosate-Cu(II) determined from swimming distance were 75.2μM and 8.4μM, respectively. In comparison, traditional visual observation of mobility resulted in 48h EC50 values of 52.8μM and 25.5μM for glyphosate and glyphosate-Cu(II), respectively. The behavioral responses indicated that exposure of D. magna to mixtures of glyphosate and Cu(II) attenuated acute metal toxicity but increased apparent glyphosate toxicity due to complexation with Cu(II). The study suggests that glyphosate is a likely mediator of aquatic metal toxicity, and that video tracking provides an opportunity for quantitative studies of sublethal effects of pesticide complexes. Copyright © 2016 Elsevier B.V. All rights reserved.

Systems biology as a conceptual framework for research in family medicine; use in predicting response to influenza vaccination.

PubMed

Majnarić-Trtica, Ljiljana; Vitale, Branko

2011-10-01

To introduce systems biology as a conceptual framework for research in family medicine, based on empirical data from a case study on the prediction of influenza vaccination outcomes. This concept is primarily oriented towards planning preventive interventions and includes systematic data recording, a multi-step research protocol and predictive modelling. Factors known to affect responses to influenza vaccination include older age, past exposure to influenza viruses, and chronic diseases; however, constructing useful prediction models remains a challenge, because of the need to identify health parameters that are appropriate for general use in modelling patients' responses. The sample consisted of 93 patients aged 50-89 years (median 69), with multiple medical conditions, who were vaccinated against influenza. Literature searches identified potentially predictive health-related parameters, including age, gender, diagnoses of the main chronic ageing diseases, anthropometric measures, and haematological and biochemical tests. By applying data mining algorithms, patterns were identified in the data set. Candidate health parameters, selected in this way, were then combined with information on past influenza virus exposure to build the prediction model using logistic regression. A highly significant prediction model was obtained, indicating that by using a systems biology approach it is possible to answer unresolved complex medical uncertainties. Adopting this systems biology approach can be expected to be useful in identifying the most appropriate target groups for other preventive programmes.

Artificial gravity as a countermeasure for mitigating physiological deconditioning during long-duration space missions

PubMed Central

Clément, Gilles R.; Bukley, Angelia P.; Paloski, William H.

2015-01-01

In spite of the experience gained in human space flight since Yuri Gagarin’s historical flight in 1961, there has yet to be identified a completely effective countermeasure for mitigating the effects of weightlessness on humans. Were astronauts to embark upon a journey to Mars today, the 6-month exposure to weightlessness en route would leave them considerably debilitated, even with the implementation of the suite of piece-meal countermeasures currently employed. Continuous or intermittent exposure to simulated gravitational states on board the spacecraft while traveling to and from Mars, also known as artificial gravity, has the potential for enhancing adaptation to Mars gravity and re-adaptation to Earth gravity. Many physiological functions are adversely affected by the weightless environment of spaceflight because they are calibrated for normal, Earth’s gravity. Hence, the concept of artificial gravity is to provide a broad-spectrum replacement for the gravitational forces that naturally occur on the Earth’s surface, thereby avoiding the physiological deconditioning that takes place in weightlessness. Because researchers have long been concerned by the adverse sensorimotor effects that occur in weightlessness as well as in rotating environments, additional study of the complex interactions among sensorimotor and other physiological systems in rotating environments must be undertaken both on Earth and in space before artificial gravity can be implemented. PMID:26136665

Cancer Risk Assessment for Space Radiation

NASA Technical Reports Server (NTRS)

Richmond, Robert C.; Cruz, Angela; Bors, Karen; Curreri, Peter A. (Technical Monitor)

2001-01-01

Predicting the occurrence of human cancer following exposure to any agent causing genetic damage is a difficult task. This is because the uncertainty of uniform exposure to the damaging agent, and the uncertainty of uniform processing of that damage within a complex set of biological variables, degrade the confidence of predicting the delayed expression of cancer as a relatively rare event within any given clinically normal individual. The radiation health research priorities for enabling long-duration human exploration of space were established in the 1996 NRC Report entitled 'Radiation Hazards to Crews of Interplanetary Missions: Biological Issues and Research Strategies'. This report emphasized that a 15-fold uncertainty in predicting radiation-induced cancer incidence must be reduced before NASA can commit humans to extended interplanetary missions. That report concluded that the great majority of this uncertainty is biologically based, while a minority is physically based due to uncertainties in radiation dosimetry and radiation transport codes. Since that report, the biologically based uncertainty has remained large, and the relatively small uncertainty associated with radiation dosimetry has increased due to the considerations raised by concepts of microdosimetry. In a practical sense, however, the additional uncertainties introduced by microdosimetry are encouraging since they are in a direction of lowered effective dose absorbed through infrequent interactions of any given cell with the high energy particle component of space radiation. Additional information is contained in the original extended abstract.

Effects of NaCl, pH, and Potential on the Static Creep Behavior of AA1100

NASA Astrophysics Data System (ADS)

Wan, Quanhe; Quesnel, David J.

2013-03-01

The creep rates of AA1100 are measured during exposure to a variety of aggressive environments. NaCl solutions of various concentrations have no influence on the steady-state creep behavior, producing creep rates comparable to those measured in lab air at room temperature. However, after an initial incubation period of steady strain rate, a dramatic increase of strain rate is observed on exposure to HCl solutions and NaOH solutions, as well as during cathodic polarization of specimens in NaCl solutions. Creep strain produces a continuous deformation and elongation of the sample surface that is comparable to slow strain rates at crack tips thought to control the kinetics of crack growth during stress corrosion cracking (SCC). In this experiment, we separate the strain and surface deformation from the complex geometry of the crack tip to better understand the processes at work. Based on this concept, two possible explanations for the environmental influences on creep strain rates are discussed relating to the anodic dissolution of the free surface and hydrogen influences on deformation mechanisms. Consistencies of pH dependence between corrosion creep and SCC at low pH prove a creep-involved SCC mechanism, while the discrepancies between corrosion creep behavior and previous SCC results at high pH indicate a rate-limit step change in the crack propagation of the SCC process.

Clinical reasoning in neurology: use of the repertory grid technique to investigate the reasoning of an experienced occupational therapist.

PubMed

Kuipers, Kathy; Grice, James W

2009-08-01

The aim of this paper is to describe the use of a structured interview methodology, the repertory grid technique, for investigating the clinical reasoning of an experienced occupational therapist in the domain of upper limb hypertonia as a result of brain injury. Repertory grid interviews were completed before and after exposure to a protocol designed to guide clinical reasoning and decision-making in relation to upper limb neurological rehabilitation. Data were subjected to both qualitative and quantitative analyses. Qualitative analysis focussed on clinical reasoning content. Common themes across the pre- and post-exposure interviews were the use of theoretical frameworks and practice models, the significance of clinical expertise, and discrimination of 'broad' and 'specific' aspects, as well as differentiation between 'therapist and client-related' aspects of the clinical situation. Quantitative analysis indicated that for both pre- and post-exposure repertory grids, clinical reasoning was structured in terms of two main concepts. In the pre-exposure grid, these were related to the therapist's role, and to the 'scope' of practice tasks (either broad or specific). In the post-exposure grid the two main concepts were upper limb performance, and client-centred aspects of the therapy process. The repertory grid technique is proposed as an effective tool for exploring occupational therapy clinical reasoning, based on its capacity for accessing personal frames of reference, and elucidating both the meaning and the structure supporting clinical reasoning.

Disease-modifying drugs for multiple sclerosis in pregnancy: a systematic review.

PubMed

Lu, Ellen; Wang, Bing Wei; Guimond, Colleen; Synnes, Anne; Sadovnick, Dessa; Tremlett, Helen

2012-09-11

To systematically review the literature regarding safety of disease-modifying drug (DMD) use during pregnancy on perinatal and developmental outcomes in offspring of patients with multiple sclerosis (MS). A PubMed and EMBASE search up to February 2012 was conducted with a manual search of references from relevant articles. Selected studies were evaluated using internationally accepted criteria. Fifteen studies identified 761 interferon β-, 97 glatiramer acetate-, and 35 natalizumab-exposed pregnancies. Study quality ranged from poor to good; no study was rated excellent. Small sample sizes limited most studies. Compared with data for unexposed pregnancies, fair- to good-quality prospective cohort studies reported that interferon β exposure was associated with lower mean birth weight, shorter mean birth length, and preterm birth (<37 weeks), but not low birth weight (<2,500 g), cesarean delivery, congenital anomaly (including malformation), or spontaneous abortion. Fewer studies of fair quality were available for glatiramer acetate and natalizumab. Glatiramer acetate exposure was not associated with lower mean birth weight, congenital anomaly, preterm birth, or spontaneous abortion. Natalizumab exposure did not appear to be associated with shorter mean birth length, lower mean birth weight, or lower mean gestational age. No studies examined mitoxantrone or fingolimod exposure. One study of paternal DMD use during conception found no effect on gestational age or birth weight. Few studies examined longer-term developmental outcomes. Further studies are needed to determine the potential risks associated with preconceptional and in utero DMD exposure in patients with MS. Discontinuation of DMDs before conception is still recommended.

EMF Monitoring—Concepts, Activities, Gaps and Options

PubMed Central

Dürrenberger, Gregor; Fröhlich, Jürg; Röösli, Martin; Mattsson, Mats-Olof

2014-01-01

Exposure to electromagnetic fields (EMF) is a cause of concern for many people. The topic will likely remain for the foreseeable future on the scientific and political agenda, since emissions continue to change in characteristics and levels due to new infrastructure deployments, smart environments and novel wireless devices. Until now, systematic and coordinated efforts to monitor EMF exposure are rare. Furthermore, virtually nothing is known about personal exposure levels. This lack of knowledge is detrimental for any evidence-based risk, exposure and health policy, management and communication. The main objective of the paper is to review the current state of EMF exposure monitoring activities in Europe, to comment on the scientific challenges and deficiencies, and to describe appropriate strategies and tools for EMF exposure assessment and monitoring to be used to support epidemiological health research and to help policy makers, administrators, industry and consumer representatives to base their decisions and communication activities on facts and data. PMID:25216256

A modular framework for biomedical concept recognition

PubMed Central

2013-01-01

Background Concept recognition is an essential task in biomedical information extraction, presenting several complex and unsolved challenges. The development of such solutions is typically performed in an ad-hoc manner or using general information extraction frameworks, which are not optimized for the biomedical domain and normally require the integration of complex external libraries and/or the development of custom tools. Results This article presents Neji, an open source framework optimized for biomedical concept recognition built around four key characteristics: modularity, scalability, speed, and usability. It integrates modules for biomedical natural language processing, such as sentence splitting, tokenization, lemmatization, part-of-speech tagging, chunking and dependency parsing. Concept recognition is provided through dictionary matching and machine learning with normalization methods. Neji also integrates an innovative concept tree implementation, supporting overlapped concept names and respective disambiguation techniques. The most popular input and output formats, namely Pubmed XML, IeXML, CoNLL and A1, are also supported. On top of the built-in functionalities, developers and researchers can implement new processing modules or pipelines, or use the provided command-line interface tool to build their own solutions, applying the most appropriate techniques to identify heterogeneous biomedical concepts. Neji was evaluated against three gold standard corpora with heterogeneous biomedical concepts (CRAFT, AnEM and NCBI disease corpus), achieving high performance results on named entity recognition (F1-measure for overlap matching: species 95%, cell 92%, cellular components 83%, gene and proteins 76%, chemicals 65%, biological processes and molecular functions 63%, disorders 85%, and anatomical entities 82%) and on entity normalization (F1-measure for overlap name matching and correct identifier included in the returned list of identifiers: species 88%, cell 71%, cellular components 72%, gene and proteins 64%, chemicals 53%, and biological processes and molecular functions 40%). Neji provides fast and multi-threaded data processing, annotating up to 1200 sentences/second when using dictionary-based concept identification. Conclusions Considering the provided features and underlying characteristics, we believe that Neji is an important contribution to the biomedical community, streamlining the development of complex concept recognition solutions. Neji is freely available at http://bioinformatics.ua.pt/neji. PMID:24063607

Early gestation as the critical time-window for changes in the prenatal environment to affect the adult human blood methylome

PubMed Central

Tobi, Elmar W; Slieker, Roderick C; Stein, Aryeh D; Suchiman, H Eka D; Slagboom, P Eline; van Zwet, Erik W; Heijmans, Bastiaan T; Lumey, LH

2015-01-01

Background: The manipulation of pregnancy diets in animals can lead to changes in DNA methylation with phenotypic consequences in the offspring. Human studies have concentrated on the effects of nutrition during early gestation. Lacking in humans is an epigenome-wide association study of DNA methylation in relation to perturbations in nutrition across all gestation periods. Methods: We used the quasi-experimental setting of the Dutch famine of 1944–45 to evaluate the impact of famine exposure during specific 10-week gestation periods, or during any time in gestation, on genome-wide DNA methylation levels at age ∼ 59 years. In addition, we evaluated the impact of exposure during a shorter pre- and post-conception period. DNA methylation was assessed using the Illumina 450k array in whole blood among 422 individuals with prenatal famine exposure and 463 time- or sibling-controls without prenatal famine exposure. Results: Famine exposure during gestation weeks 1–10, but not weeks 11–20, 21–30 or 31-delivery, was associated with an increase in DNA methylation of CpG dinucleotides cg20823026 (FAM150B), cg10354880 (SLC38A2) and cg27370573 (PPAP2C) and a decrease of cg11496778 (OSBPL5/MRGPRG) (P < 5.9 × 10−7, PFDR < 0.031). There was an increase in methylation of TACC1 and ZNF385A after exposure during any time in gestation (P < 2.0 × 10−7, PFDR = 0.034) and a decrease of cg23989336 (TMEM105) after exposure around conception. These changes represent a shift of 0.3–0.6 standard deviations and are linked to genes involved in growth, development and metabolism. Conclusion: Early gestation, and not mid or late gestation, is identified as a critical time-period for adult DNA methylation changes in whole blood after prenatal exposure to famine. PMID:25944819

Gene and Protein Expression following Exposure to Radiofrequency Fields from Mobile Phones

PubMed Central

Vanderstraeten, Jacques; Verschaeve, Luc

2008-01-01

Background Since 1999, several articles have been published on genome-wide and/or proteome-wide response after exposure to radiofrequency (RF) fields whose signal and intensities were similar to or typical of those of currently used mobile telephones. These studies were performed using powerful high-throughput screening techniques (HTSTs) of transcriptomics and/or proteomics, which allow for the simultaneous screening of the expression of thousands of genes or proteins. Objectives We reviewed these HTST-based studies and compared the results with currently accepted concepts about the effects of RF fields on gene expression. In this article we also discuss these last in light of the recent concept of microwave-assisted chemistry. Discussion To date, the results of HTST-based studies of transcriptomics and/or proteomics after exposure to RF fields relevant to human exposure are still inconclusive, as most of the positive reports are flawed by methodologic imperfections or shortcomings. In addition, when positive findings were reported, no precise response pattern could be identified in a reproducible way. In particular, results from HTST studies tend to exclude the role of a cell stressor for exposure to RF fields at nonthermal intensities. However, on the basis of lessons from microwave-assisted chemistry, we can assume that RF fields might affect heat-sensitive gene or protein expression to an extent larger than would be predicted from temperature change only. But in all likelihood, this would concern intensities higher than those relevant to usual human exposure. Conclusions The precise role of transcriptomics and proteomics in the screening of bioeffects from exposure to RF fields from mobile phones is still uncertain in view of the lack of positively identified phenotypic change and the lack of theoretical, as well as experimental, arguments for specific gene and/or protein response patterns after this kind of exposure. PMID:18795152

Effects of Polar Bear and Killer Whale Derived Contaminant Cocktails on Marine Mammal Immunity.

PubMed

Desforges, Jean-Pierre; Levin, Milton; Jasperse, Lindsay; De Guise, Sylvain; Eulaers, Igor; Letcher, Robert J; Acquarone, Mario; Nordøy, Erling; Folkow, Lars P; Hammer Jensen, Trine; Grøndahl, Carsten; Bertelsen, Mads F; St Leger, Judy; Almunia, Javier; Sonne, Christian; Dietz, Rune

2017-10-03

Most controlled toxicity studies use single chemical exposures that do not represent the real world situation of complex mixtures of known and unknown natural and anthropogenic substances. In the present study, complex contaminant cocktails derived from the blubber of polar bears (PB; Ursus maritimus) and killer whales (KW; Orcinus orca) were used for in vitro concentration-response experiments with PB, cetacean and seal spp. immune cells to evaluate the effect of realistic contaminant mixtures on various immune functions. Cytotoxic effects of the PB cocktail occurred at lower concentrations than the KW cocktail (1 vs 16 μg/mL), likely due to differences in contaminant profiles in the mixtures derived from the adipose of each species. Similarly, significant reduction of lymphocyte proliferation occurred at much lower exposures in the PB cocktail (EC 50 : 0.94 vs 6.06 μg/mL; P < 0.01), whereas the KW cocktail caused a much faster decline in proliferation (slope: 2.9 vs 1.7; P = 0.04). Only the KW cocktail modulated natural killer (NK) cell activity and neutrophil and monocyte phagocytosis in a concentration- and species-dependent manner. No clear sensitivity differences emerged when comparing cetaceans, seals and PB. Our results showing lower effect levels for complex mixtures relative to single compounds suggest that previous risk assessments underestimate the effects of real world contaminant exposure on immunity. Our results using blubber-derived contaminant cocktails add realism to in vitro exposure experiments and confirm the immunotoxic risk marine mammals face from exposure to complex mixtures of environmental contaminants.

A simulation study to determine the attenuation and bias in health risk estimates due to exposure measurement error in bi-pollutant models

EPA Science Inventory

To understand the combined health effects of exposure to ambient air pollutant mixtures, it is becoming more common to include multiple pollutants in epidemiologic models. However, the complex spatial and temporal pattern of ambient pollutant concentrations and related exposures ...

Modeling Particle Exposure in US Trucking Terminals

PubMed Central

Davis, ME; Smith, TJ; Laden, F; Hart, JE; Ryan, LM; Garshick, E

2007-01-01

Multi-tiered sampling approaches are common in environmental and occupational exposure assessment, where exposures for a given individual are often modeled based on simultaneous measurements taken at multiple indoor and outdoor sites. The monitoring data from such studies is hierarchical by design, imposing a complex covariance structure that must be accounted for in order to obtain unbiased estimates of exposure. Statistical methods such as structural equation modeling (SEM) represent a useful alternative to simple linear regression in these cases, providing simultaneous and unbiased predictions of each level of exposure based on a set of covariates specific to the exposure setting. We test the SEM approach using data from a large exposure assessment of diesel and combustion particles in the US trucking industry. The exposure assessment includes data from 36 different trucking terminals across the United States sampled between 2001 and 2005, measuring PM2.5 and its elemental carbon (EC), organic carbon (OC) components, by personal monitoring, and sampling at two indoor work locations and an outdoor “background” location. Using the SEM method, we predict: 1) personal exposures as a function of work related exposure and smoking status; 2) work related exposure as a function of terminal characteristics, indoor ventilation, job location, and background exposure conditions; and 3) background exposure conditions as a function of weather, nearby source pollution, and other regional differences across terminal sites. The primary advantage of SEMs in this setting is the ability to simultaneously predict exposures at each of the sampling locations, while accounting for the complex covariance structure among the measurements and descriptive variables. The statistically significant results and high R2 values observed from the trucking industry application supports the broader use of this approach in exposure assessment modeling. PMID:16856739

The influence of teachers' conceptions on their students' learning: children's understanding of sheet music.

PubMed

López-Íñiguez, Guadalupe; Pozo, Juan Ignacio

2014-06-01

Despite increasing interest in teachers' and students' conceptions of learning and teaching, and how they influence their practice, there are few studies testing the influence of teachers' conceptions on their students' learning. This study tests how teaching conception (TC; with a distinction between direct and constructive) influences students' representations regarding sheet music. Sixty students (8-12 years old) from music conservatories: 30 of them took lessons with teachers with a constructive TC and another 30 with teachers shown to have a direct TC. Children were given a musical comprehension task in which they were asked to select and rank the contents they needed to learn. These contents had different levels of processing and complexity: symbolic, analytical, and referential. Three factorial ANOVAs, two-one-way ANOVAs, and four 2 × 3 repeated-measures ANOVAs were used to analyse the effects of and the interaction between the independent variables TC and class, both for/on total cards selected, their ranking, and each sub-category (the three processing levels). ANOVAs on the selection and ranking of these contents showed that teachers' conceptions seem to mediate significantly in the way the students understand the music. Students from constructive teachers have more complex and deep understanding of music. They select more elements for learning scores than those from traditional teachers. Teaching conception also influences the way in which children rank those elements. No difference exists between the way 8- and 12-year-olds learn scores. Children's understanding of the scores is more complex than assumed in other studies. © 2013 The British Psychological Society.

Exposure histories of lunar rocks 71135 and 71569

NASA Technical Reports Server (NTRS)

Niemeyer, S.

1977-01-01

Rare-gas isotopic analyses have been performed on lunar rocks 71135 and 71569. The conventional (Kr-81)-Kr cosmic-ray exposure ages are 103 + or - 3 m.y. for 71135 and 134 + or - 7 m.y. for 71569. An approach is outlined to deducing complex exposure histories from rare-gas data using depth profiles of the production rates of the cosmogenic rare-gas isotopes. Examination of the Xe isotopes by means of a 'concordia' plot suggests that 71569 may have a simple one-stage exposure history whereas 71135 has a more complex history. An attempt is made to construct exposure models for these two rocks which account for the abundances of all the cosmogenic rare gases, the Xe isotopic compositions, and the apparent (Kr-81)-Kr exposure ages. This study demonstrates the depreciation of (Kr-81)-Kr ages for rocks exposed at shallow depths, caused by the relatively rapid variation of the Kr-81 production as the rock is eroded. Possible implications of the tentative results for the formation age of the Central Cluster unit are discussed.

A Complex Interaction Between Reduced Reelin Expression and Prenatal Organophosphate Exposure Alters Neuronal Cell Morphology.

PubMed

Mullen, Brian R; Ross, Brennan; Chou, Joan Wang; Khankan, Rana; Khialeeva, Elvira; Bui, Kimberly; Carpenter, Ellen M

2016-06-01

Genetic and environmental factors are both likely to contribute to neurodevelopmental disorders including schizophrenia, autism spectrum disorders, and major depressive disorders. Prior studies from our laboratory and others have demonstrated that the combinatorial effect of two factors-reduced expression of reelin protein and prenatal exposure to the organophosphate pesticide chlorpyrifos oxon-gives rise to acute biochemical effects and to morphological and behavioral phenotypes in adolescent and young adult mice. In the current study, we examine the consequences of these factors on reelin protein expression and neuronal cell morphology in adult mice. While the cell populations that express reelin in the adult brain appear unchanged in location and distribution, the levels of full length and cleaved reelin protein show persistent reductions following prenatal exposure to chlorpyrifos oxon. Cell positioning and organization in the hippocampus and cerebellum are largely normal in animals with either reduced reelin expression or prenatal exposure to chlorpyrifos oxon, but cellular complexity and dendritic spine organization is altered, with a skewed distribution of immature dendritic spines in adult animals. Paradoxically, combinatorial exposure to both factors appears to generate a rescue of the dendritic spine phenotypes, similar to the mitigation of behavioral and morphological changes observed in our prior study. Together, our observations support an interaction between reelin expression and chlorpyrifos oxon exposure that is not simply additive, suggesting a complex interplay between genetic and environmental factors in regulating brain morphology. © The Author(s) 2016.

Soaring to New Heights.

ERIC Educational Resources Information Center

Schwerin, Alan

1994-01-01

Describes procedures for a hands-on activity for students that involves the construction of radio-controlled model sailplane (or glider) kits, exposure to basic aerodynamic theory and concepts, and some flight school on a midsized field. (ZWH)

Concepts for NASA longitudinal health studies

NASA Technical Reports Server (NTRS)

Nicogossian, A. E.; Pool, S. L.; Leach, C. S.; Moseley, E.; Rambaut, P. C.

1983-01-01

Clinical data collected from a 15-year study of the homogenous group of pre-Shuttle astronauts have revealed no significant long-term effects from spaceflight. The current hypothesis suggests that repeated exposures to the space environment in the Shuttle era will similarly have no long-term health effects. However, a much more heterogenous group of astronauts and non-astronaut scientists will fly in Shuttle, and data on this group's adaptation to the space environment and readaptation to earth are currently sparse. In addition, very little information is available concerning the short- and long-term medical consequences of long duration exposure to space and subsequent readaptation to the earth environment. In this paper, retrospective clinical information on astronauts is reviewed and concepts for conducting epidemiological studies examining long-term health effects of spaceflight on humans, including associated occupational risks factors, are presented.

Convergence of External Crohn’s Disease Risk Factors on Intestinal Bacteria

PubMed Central

Oberc, Alexander; Coombes, Brian K.

2015-01-01

Crohn’s disease (CD) is an immune-mediated intestinal illness that significantly compromises health in many developed countries. Although definitive causes remain elusive, the required contribution of microbes in the progression of disease has become an accepted concept. Known CD risk factors, such as antibiotic use and acute infectious gastroenteritis, may impact the gut. This concept is now being explored with a view toward understanding the beneficial and unfavorable microbes that may be altered in numbers during such external insults. A comprehensive understanding of the microbial component to CD could be useful clinically as future therapies may focus on preventing risk exposures on susceptible individuals, eliminating harmful microbes, or restoring a protective gut microbiome. Here, we examine how acute infectious gastroenteritis and antibiotic exposure may impact the gut microbiota in the context of inflammation in CD. PMID:26579131

Radiation protection effectiveness of a proposed magnetic shielding concept for manned Mars missions

NASA Technical Reports Server (NTRS)

Townsend, Lawrence W.; Wilson, John W.; Shinn, J. L.; Nealy, John E.; Simonsen, Lisa C.

1990-01-01

The effectiveness of a proposed concept for shielding a manned Mars vehicle using a confined magnetic field configuration is evaluated by computing estimated crew radiation exposures resulting from galactic cosmic rays and a large solar flare event. In the study the incident radiation spectra are transported through the spacecraft structure/magnetic shield using the deterministic space radiation transport computer codes developed at Langley Research Center. The calculated exposures unequivocally demonstrate that magnetic shielding could provide an effective barrier against solar flare protons but is virtually transparent to the more energetic galactic cosmic rays. It is then demonstrated that through proper selection of materials and shield configuration, adequate and reliable bulk material shielding can be provided for the same total mass as needed to generate and support the more risky magnetic field configuration.

Providing Experiential Business and Management Training for Biomedical Research Trainees

PubMed Central

Petrie, Kimberly A.; Carnahan, Robert H.; Brown, Abigail M.; Gould, Kathleen L.

2017-01-01

Many biomedical PhD trainees lack exposure to business principles, which limits their competitiveness and effectiveness in academic and industry careers. To fill this training gap, we developed Business and Management Principles for Scientists, a semester-long program that combined didactic exposure to business fundamentals with practical team-based projects aimed at solving real business problems encountered by institutional shared-­resource core facilities. The program also included a retreat featuring presentations by and networking with local life science entrepreneurs and final team presentations to expert judges. Quantitative and qualitative metrics were used to evaluate the program’s impact on trainees. A pretest–posttest approach was used to assess trainees’ baseline knowledge and mastery of module concepts, and each individual’s pretest and posttest responses were compared. The mean score improved by more than 17 percentage points. Trainees also took an online survey to provide feedback about the module. Nearly all participants agreed or strongly agreed that the module was a valuable use of their time and will help guide their career decisions and that project work helped drive home module concepts. More than 75% of trainees reported discussing the module with their research advisors, and all of these participants reported supportive or neutral responses. Collectively, the trainee feedback about the module, improvement in test scores, and trainee perception of advisor support suggest that this short module is an effective method of providing scientists with efficient and meaningful exposure to business concepts. PMID:28798213

Sexual and reproductive behaviour among single women aged 15-24 in eight Latin American countries: a comparative analysis.

PubMed

Ali, Mohamed M; Cleland, John

2005-03-01

A comparative analysis of exposure to sexual activity, contraceptive use, conceptions, and pregnancy resolutions among single women aged 15-24 in eight Latin American countries is presented. Using data from Demographic and Health Surveys complete contraceptive and reproductive histories are constructed for single women aged 15-24 during the 5 year period preceding each survey. Pre-marital conception rates and overall and cause-specific life-table probabilities of contraceptive discontinuation are estimated. Pregnancy outcome and intention status of births are summarized. Trends in virginity, contraceptive protection, and conception rates for five sites are documented. In all eight countries, virginity accounts for over half of all single woman-years of exposure between age 15 and 24. The percentage of sexually active time protected by contraception is less than 20% in five countries, is about 30% in Peru and 50% in Brazil and Colombia. The contribution of condoms to contraceptive protection ranges from one-tenth to one-fifth. Pre-marital conception rates among sexually active single women range from 14.1 per 100 woman-years in Nicaragua to 25.8 in Bolivia. Most pre-marital conceptions ended in live birth, and births that are legitimized by marriage or cohabitation are more likely to be wanted. In five settings, virginity has fallen over time, especially in Northeast Brazil and Colombia, and uptake of condoms has increased faster than use of other methods. Because of pervasive declines in the protective effect of virginity, conception rates among single women in Latin America are rising. Contraceptive uptake, particularly of condoms, is increasing but not sufficiently to offset the decline in virginity.

Typological diversity of tall buildings and complexes in relation to their functional structure

NASA Astrophysics Data System (ADS)

Generalov, Viktor P.; Generalova, Elena M.; Kalinkina, Nadezhda A.; Zhdanova, Irina V.

2018-03-01

The paper focuses on peculiarities of tall buildings and complexes, their typology and its formation in relation to their functional structure. The research is based on the analysis of tall buildings and complexes and identifies the following main functional elements of their formation: residential, administrative (office), hotel elements. The paper also considers the following services as «disseminated» in the space-planning structure: shops, medicine, entertainment, kids and sports facilities, etc., their location in the structure of the total bulk of the building and their impact on typological diversity. Research results include suggestions to add such concepts as «single-function tall buildings» and «mixed-use tall buildings and complexes» into the classification of tall buildings. In addition, if a single-function building or complex performs serving functions, it is proposed to add such concepts as «a residential tall building (complex) with provision of services», «an administrative (public) tall building (complex) with provision of services» into the classification of tall buildings. For mixed-use buildings and complexes the following terms are suggested: «a mixed-use tall building with provision of services», «a mixed-use tall complex with provision of services».

Adapting Strategic Aircraft Assets to a Changing World: Technology Insertion to Provide Flexibility

DTIC Science & Technology

1994-09-01

Distributed Processing ............................ 67 Unembedded Expansions ............................ 71 Concepts for, and Impacts on, Preflight...capabilities through the use of unembedded expansions to the existing avionics complex. But, before we explore these technology insertion concepts, we must... Unembedded Expansions The final hardware technology insertion area focuses on the concept of expanding the aircraft’s capabilities by inserting, or perhaps

Foundations of Children's Self-Concepts about Everyday Activities: Identities and Comparative Contexts

ERIC Educational Resources Information Center

Fisher, Laurel

2014-01-01

Children's motivations to engage in everyday activities draw on their experiences in thinking of oneself and the activities. In theory, these personal and social realities provide the complex foundations of self-concepts. The aim of this project was to define the foundations of children's self-concepts about everyday activities; to focus…

Concept-Based Curriculum and Instruction for the Thinking Classroom. Second Edition (Revised Edition). Concept-Based Curriculum and Instruction Series

ERIC Educational Resources Information Center

Erickson, H. Lynn; Lanning, Lois A.; French, Rachel

2017-01-01

Knowing the facts is not enough. If we want students to develop intellectually, creatively problem-solve, and grapple with complexity, the key is in "conceptual understanding." A Concept-Based curriculum recaptures students' innate curiosity about the world and provides the thrilling feeling of engaging one's mind. This updated edition…

Pre-Service Physics Teachers' Content Knowledge of Electric and Magnetic Field Concepts: Conceptual Facets and Their Balance

ERIC Educational Resources Information Center

Nousiainen, Maija; Koponen, Ismo T.

2017-01-01

The concepts of electricity and magnetism in physics are complex and demanding to learn because their meaning builds through several different phenomenological areas. Each of the phenomenological areas adds a certain facet of the meaning of the concept. All standard physics textbooks discuss at least 1) force, 2) energy and work, and 3) electric…

A Novel Approach to Exploring the Concept of Resilience and Principal Drivers in a Learning Environment

ERIC Educational Resources Information Center

Matzenberger, Julian

2013-01-01

Purpose: The concept of resilience has emerged recently in scientific debate. The aim of this paper is to outline different notions of the term resilience and explore how the concept of resilience can be applied in order to foster the understanding of complex systems in a learning environment. Design/methodology/approach: Characteristics of the…

Application of Relational Contracting Methods to Federal Construction Projects

DTIC Science & Technology

2011-03-24

59 viii List of Figures Page Figure 1 Wittgenstein Model (Chan et al., 2010...a precise and comprehensive definition of the concept (Chan et al, 2010). Ludwig Wittgenstein argued that complex concepts are unable to be defined...recently, Chan et al. (2010) utilized the Wittgenstein concept and both of these previous researchers’ work to develop a model of the elements of

The life of concepts: Georges Canguilhem and the history of science.

PubMed

Schmidgen, Henning

2014-01-01

Twelve years after his famous Essay on Some Problems Concerning the Normal and the Pathological (1943), the philosopher Georges Canguilhem (1904-1995) published a book-length study on the history of a single biological concept. Within France, his Formation of the Reflex Concept in the Seventeenth and Eighteenth Centuries (1955) contributed significantly to defining the "French style" of writing on the history of science. Outside of France, the book passed largely unnoticed. This paper re-reads Canguilhem's study of the reflex concept with respect to its historiographical and epistemological implications. Canguilhem defines concepts as complex and dynamic entities combining terms, definitions, and phenomena. As a consequence, the historiography of science becomes a rather complex task. It has to take into account textual and contextual aspects that develop independently of individual authors. In addition, Canguilhem stresses the connection between conceptual activities and other functions of organic individuals in their respective environments. As a result, biological concepts become tied to a biology of conceptual thinking, analogical reasoning, and technological practice. The paper argues that this seemingly circular structure is a major feature in Canguilhem's philosophical approach to the history of the biological sciences.

Exposure-time based modeling of nonlinear reactive transport in porous media subject to physical and geochemical heterogeneity.

PubMed

Sanz-Prat, Alicia; Lu, Chuanhe; Amos, Richard T; Finkel, Michael; Blowes, David W; Cirpka, Olaf A

2016-09-01

Transport of reactive solutes in groundwater is affected by physical and chemical heterogeneity of the porous medium, leading to complex spatio-temporal patterns of concentrations and reaction rates. For certain cases of bioreactive transport, it could be shown that the concentrations of reactive constituents in multi-dimensional domains are approximately aligned with isochrones, that is, lines of identical travel time, provided that the chemical properties of the matrix are uniform. We extend this concept to combined physical and chemical heterogeneity by additionally considering the time that a water parcel has been exposed to reactive materials, the so-called exposure time. We simulate bioreactive transport in a one-dimensional domain as function of time and exposure time, rather than space. Subsequently, we map the concentrations to multi-dimensional heterogeneous domains by means of the mean exposure time at each location in the multi-dimensional domain. Differences in travel and exposure time at a given location are accounted for as time difference. This approximation simplifies reactive-transport simulations significantly under conditions of steady-state flow when reactions are restricted to specific locations. It is not expected to be exact in realistic applications because the underlying assumption, such as neglecting transverse mixing altogether, may not hold. We quantify the error introduced by the approximation for the hypothetical case of a two-dimensional, binary aquifer made of highly-permeable, non-reactive and low-permeable, reactive materials releasing dissolved organic matter acting as electron donor for aerobic respiration and denitrification. The kinetically controlled reactions are catalyzed by two non-competitive bacteria populations, enabling microbial growth. Even though the initial biomass concentrations were uniform, the interplay between transport, non-uniform electron-donor supply, and bio-reactions led to distinct spatial patterns of the two types of biomass at late times. Results obtained by mapping the exposure-time based results to the two-dimensional domain are compared with simulations based on the two-dimensional, spatially explicit advection-dispersion-reaction equation. Once quasi-steady state has been reached, we find a good agreement in terms of the chemical-compound concentrations between the two approaches inside the reactive zones, whereas the exposure-time based model is not able to capture reactions occurring in the zones with zero electron-donor release. We conclude that exposure-time models provide good approximations of nonlinear bio-reactive transport when transverse mixing is not the overall controlling process and all reactions are essentially restricted to distinct reactive zones. Copyright © 2016 Elsevier B.V. All rights reserved.

Predicting and controlling risks from human exposures to vibration and mechanical shock: flag waving and flag weaving.

PubMed

Griffin, Michael J

2015-01-01

At work or in leisure activities, many people are exposed to vibration or mechanical shocks associated with risks of injury or disease. This paper identifies information that can be used to decide whether there may be a risk from exposure to hand-transmitted vibration or whole-body vibration and shock, and suggests actions that can control the risks. The complex and time-varying nature of human exposures to vibration and shock, the complexity of the different disorders and uncertainty as to the mechanisms of injury and the factors influencing injury have prevented the definition of dose-response relationships well proven by scientific study. It is necessary to wave a flag indicating when there is a need to control risks from exposure to vibration and shock while scientific enquiry provides understanding needed to weave a better flag. It is concluded that quantifying exposure severity is often neither necessary nor sufficient to either identify risks or implement measures that control the risks. The identification of risks associated with exposure to vibration and mechanical shock cannot, and need not, rely solely on the quantification of exposure severity. Qualitative methods can provide a sufficient indication of the need for control measures, which should not be restricted to reducing standardised measures of exposure severity.

Verification of E-Beam direct write integration into 28nm BEOL SRAM technology

NASA Astrophysics Data System (ADS)

Hohle, Christoph; Choi, Kang-Hoon; Gutsch, Manuela; Hanisch, Norbert; Seidel, Robert; Steidel, Katja; Thrun, Xaver; Werner, Thomas

2015-03-01

Electron beam direct write lithography (EBDW) potentially offers advantages for low-volume semiconductor manufacturing, rapid prototyping or design verification due to its high flexibility without the need of costly masks. However, the integration of this advanced patterning technology into complex CMOS manufacturing processes remains challenging. The low throughput of today's single e-Beam tools limits high volume manufacturing applications and maturity of parallel (multi) beam systems is still insufficient [1,2]. Additional concerns like transistor or material damage of underlying layers during exposure at high electron density or acceleration voltage have to be addressed for advanced technology nodes. In the past we successfully proved that potential degradation effects of high-k materials or ULK shrink can be neglected and were excluded by demonstrating integrated electrical results of 28nm node transistor and BEOL performance following 50kV electron beam dry exposure [3]. Here we will give an update on the integration of EBDW in the 300mm CMOS manufacturing processes of advanced integrated circuits at the 28nm SRAM node of GLOBALFOUNDRIES Dresden. The work is an update to what has been previously published [4]. E-beam patterning results of BEOL full chip metal and via layers with a dual damascene integration scheme using a 50kV VISTEC SB3050DW variable shaped electron beam direct writer at Fraunhofer IPMSCNT are demonstrated. For the patterning of the Metal layer a Mix & Match concept based on the sequence litho - etch -litho -etch (LELE) was developed and evaluated wherein several exposure fields were blanked out during the optical exposure. Etch results are shown and compared to the POR. Results are also shown on overlay performance and optimized e-Beam exposure time using most advanced data prep solutions and resist processes. The patterning results have been verified using fully integrated electrical measurement of metal lines and vias on wafer level. In summary we demonstrate the integration capability of EBDW into a productive CMOS process flow at the example of the 28nm SRAM technology node.

Non-targeted, high resolution mass spectrometry strategy for simultaneous monitoring of xenobiotics and endogenous compounds in green sea turtles on the Great Barrier Reef.

PubMed

Heffernan, Amy L; Gómez-Ramos, Maria M; Gaus, Caroline; Vijayasarathy, Soumini; Bell, Ian; Hof, Christine; Mueller, Jochen F; Gómez-Ramos, Maria J

2017-12-01

Chemical contamination poses a threat to ecosystem, biota and human health, and identifying these hazards is a complex challenge. Traditional hazard identification relies on a priori-defined targets of limited chemical scope, and is generally inappropriate for exploratory studies such as explaining toxicological effects in environmental systems. Here we present a non-target high resolution mass spectrometry environmental monitoring study with multivariate statistical analysis to simultaneously detect biomarkers of exposure (e.g. xenobiotics) and biomarkers of effect in whole turtle blood. Borrowing the concept from clinical chemistry, a case-control sampling approach was used to investigate the potential influence of xenobiotics of anthropogenic origin on free-ranging green sea turtles (Chelonia mydas) from a remote, offshore 'control' site; and two coastal 'case' sites influenced by urban/industrial and agricultural activities, respectively, on the Great Barrier Reef in North Queensland, Australia. Multiple biomarkers of exposure, including sulfonic acids (n=9), a carbamate insecticide metabolite, and other industrial chemicals; and five biomarkers of effect (lipid peroxidation products), were detected in case sites. Additionally, two endogenous biomarkers of neuroinflammation and oxidative stress were identified, and showed moderate-to-strong correlations with clinical measures of inflammation and liver dysfunction. Our data filtering strategy overcomes limitations of traditional a priori selection of target compounds, and adds to the limited environmental xenobiotic metabolomics literature. To our knowledge this is the first case-control study of xenobiotics in marine megafauna, and demonstrates the utility of green sea turtles to link internal and external exposure, to explain potential toxicological effects in environmental systems. Copyright © 2017 Elsevier B.V. All rights reserved.

Editor's Highlight: Congener-Specific Disposition of Chiral Polychlorinated Biphenyls in Lactating Mice and Their Offspring: Implications for PCB Developmental Neurotoxicity.

PubMed

Kania-Korwel, Izabela; Lukasiewicz, Tracy; Barnhart, Christopher D; Stamou, Marianna; Chung, Haeun; Kelly, Kevin M; Bandiera, Stelvio; Lein, Pamela J; Lehmler, Hans-Joachim

2017-07-01

Chiral polychlorinated biphenyl (PCB) congeners have been implicated by laboratory and epidemiological studies in PCB developmental neurotoxicity. These congeners are metabolized by cytochrome P450 (P450) enzymes to potentially neurotoxic hydroxylated metabolites (OH-PCBs). The present study explores the enantioselective disposition and toxicity of 2 environmentally relevant, neurotoxic PCB congeners and their OH-PCB metabolites in lactating mice and their offspring following dietary exposure of the dam. Female C57BL/6N mice (8-weeks old) were fed daily, beginning 2 weeks prior to conception and continuing throughout gestation and lactation, with 3.1 µmol/kg bw/d of racemic 2,2',3,5',6-pentachlorobiphenyl (PCB 95) or 2,2',3,3',6,6'-hexachlorobiphenyl (PCB 136) in peanut butter; controls received vehicle (peanut oil) in peanut butter. PCB 95 levels were higher than PCB 136 levels in both dams and pups, consistent with the more rapid metabolism of PCB 136 compared with PCB 95. In pups and dams, both congeners were enriched for the enantiomer eluting second on enantioselective gas chromatography columns. OH-PCB profiles in lactating mice and their offspring were complex and varied according to congener, tissue and age. Developmental exposure to PCB 95 versus PCB 136 differentially affected the expression of P450 enzymes as well as neural plasticity (arc and ppp1r9b) and thyroid hormone-responsive genes (nrgn and mbp). The results suggest that the enantioselective metabolism of PCBs to OH-PCBs may influence neurotoxic outcomes following developmental exposures, a hypothesis that warrants further investigation. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

A concept taxonomy and an instrument hierarchy: tools for establishing and evaluating the conceptual framework of a patient-reported outcome (PRO) instrument as applied to product labeling claims.

PubMed

Erickson, Pennifer; Willke, Richard; Burke, Laurie

2009-01-01

To facilitate development and evaluation of a PRO instrument conceptual framework, we propose two tools--a PRO concept taxonomy and a PRO instrument hierarchy. FDA's draft guidance on patient reported outcome (PRO) measures states that a clear description of the conceptual framework of an instrument is useful for evaluating its adequacy to support a treatment benefit claim for use in product labeling the draft guidance, however does not propose tools for establishing or evaluating a PRO instrument's conceptual framework. We draw from our review of PRO concepts and instruments that appear in prescription drug labeling approved in the United States from 1997 to 2007. We propose taxonomy terms that define relationships between PRO concepts, including "family,"compound concept," and "singular concept." Based on the range of complexity represented by the concepts, as defined by the taxonomy, we propose nine instrument orders for PRO measurement. The nine orders range from individual event counts to multi-item, multiscale instruments. This analysis of PRO concepts and instruments illustrates that the taxonomy and hierarchy are applicable to PRO concepts across a wide range of therapeutic areas and provide a basis for defining the instrument conceptual framework complexity. Although the utility of these tools in the drug development, review, and approval processes has not yet been demonstrated, these tools could be useful to improve communication and enhance efficiency in the instrument development and review process.

Occupational exposure of personnel operating military radio equipment: measurements and simulation.

PubMed

Paljanos, Annamaria; Miclaus, Simona; Munteanu, Calin

2015-09-01

Technical literature provides numerous studies concerning radiofrequency exposure measurements for various radio communication devices, but there are few studies related to exposure of personnel operating military radio equipment. In order to evaluate exposure and identify cases when safety requirements are not entirely met, both measurements and simulations are needed for accurate results. Moreover, given the technical characteristics of the radio devices used in the military, personnel mainly operate in the near-field region so both measurements and simulation becomes more complex. Measurements were made in situ using a broadband personal exposimeter equipped with two isotropic probes for both electric and magnetic components of the field. The experiment was designed for three different operating frequencies of the same radio equipment, while simulations were made in FEKO software using hybrid numerical methods to solve complex electromagnetic field problems. The paper aims to discuss the comparative results of the measurements and simulation, as well as comparing them to reference levels specified in military or civilian radiofrequency exposure standards.

Studying complex interventions: reflections from the FEMHealth project on evaluating fee exemption policies in West Africa and Morocco.

PubMed

Marchal, Bruno; Van Belle, Sara; De Brouwere, Vincent; Witter, Sophie

2013-11-08

The importance of complexity in health care policy-making and interventions, as well as research and evaluation is now widely acknowledged, but conceptual confusion reigns and few applications of complexity concepts in research design have been published. Taking user fee exemption policies as an entry point, we explore the methodological consequences of 'complexity' for health policy research and evaluation. We first discuss the difference between simple, complicated and complex and introduce key concepts of complex adaptive systems theory. We then apply these to fee exemption policies. We describe how the FEMHealth research project attempts to address the challenges of complexity in its evaluation of fee exemption policies for maternal care. We present how the development of a programme theory for fee exemption policies was used to structure the overall design. This allowed for structured discussions on the hypotheses held by the researchers and helped to structure, integrate and monitor the sub-studies. We then show how the choice of data collection methods and tools for each sub-study was informed by the overall design. Applying key concepts from complexity theory proved useful in broadening our view on fee exemption policies and in developing the overall research design. However, we encountered a number of challenges, including maintaining adaptiveness of the design during the evaluation, and ensuring cohesion in the disciplinary diversity of the research teams. Whether the programme theory can fulfil its claimed potential to help making sense of the findings is yet to be tested. Experience from other studies allows for some moderate optimism. However, the biggest challenge complexity throws at health system researchers may be to deal with the unknown unknowns and the consequence that complex issues can only be understood in retrospect. From a complexity theory point of view, only plausible explanations can be developed, not predictive theories. Yet here, theory-driven approaches may help.

RAFCON: A Graphical Tool for Engineering Complex, Robotic Tasks

DTIC Science & Technology

2016-10-09

Robotic tasks are becoming increasingly complex, and with this also the robotic systems. This requires new tools to manage this complexity and to...execution of robotic tasks, called RAFCON. These tasks are described in hierarchical state machines supporting concurrency. A formal notation of this concept

N-acetyltransferase single nucleotide polymorphisms: Emerging concepts serve as a paradigm for understanding complexities of personalized medicine

PubMed Central

Hein, David W.

2009-01-01

Arylamine N-acetyltransferase 1 (NAT1) and 2 (NAT2) exhibit single nucleotide polymorphisms (SNPs) in human populations that modify drug and carcinogen metabolism. This paper updates the identity, location, and functional effects of these SNPs and then follows with emerging concepts for understanding why pharmacogenetic findings may not be replicated consistently. Using this paradigm as an example, laboratory-based mechanistic analyses can reveal complexities such that genetic polymorphisms become biologically and medically relevant when confounding factors are more fully understood and considered. As medical care moves to a more personalized approach, the implications of these confounding factors will be important in understanding the complexities of personalized medicine. PMID:19379125

Air emissions from sour-gas processing plants and dairy-cattle reproduction in Alberta, Canada.

PubMed

Scott, H M; Soskolne, C L; Martin, S W; Shoukri, M M; Lissemore, K D; Coppock, R W; Guidotti, T L

2003-02-15

The dispersion of air pollutants from all 231 licensed sour-gas processing plants in Alberta, Canada, was modeled on a monthly basis over a 10-year period (1985-1994). Exposure estimates for sulfur dioxide (SO(2)-used as a surrogate for exposure to combusted emissions) then were assigned to 1382 provincial dairy farms using a geographical-information system. Individual average and peak exposure for periods prior to each of 15 months of age and conception (four exposure-averaging periods for each of two dispersion models) were estimated for 163,988 primiparous female dairy-cattle between 1986 and 1994. Monthly or annual average farm-site exposure estimates likewise were assigned to associated herd-level data sets for the biologically relevant period of interest for each of three additional reproductive outcomes: monthly herd-average calving interval, stillbirth risk, and twinning risk. In one of the main-effects models, the maximum (i.e., peak) monthly sour-gas exposure experienced by individual-animals from birth to conception was associated with an increased time to first-calving in the very-highest exposure category (hazard ratio=0.86, 95% CI=0.80, 0.92). This equates to a decreased hazard (lambda) of calving (in each month subsequent to 22 months of age) for the highest-exposure animals (lambda=0.170) versus the zero-exposure animals (lambda=0.198) in a model with referent values for agro-ecological region and season of birth. The dose-response was not consistent across the full range of exposure categories. There was significant (P=0.003) interaction of emissions with agro-ecological region. After accounting for the interaction, a more-consistent dose-response was evident for some (but not all) agro-ecological regions. This suggests that any effect of emissions on dairy-heifer reproduction is subject to modification by features of soil type, vegetative cover, and/or climate. The increase in monthly herd-average calving interval on farms exposed to the very-highest levels of emissions appeared quite small and of limited practical importance within the range of expected exposures. There was no association between exposure and the risk for twinning. Herds exposed to higher emissions exhibited a slight decrease in risk for stillbirth.

Assessing the Exposome with External Measures: Commentary on the State of the Science and Research Recommendations.

PubMed

Turner, Michelle C; Nieuwenhuijsen, Mark; Anderson, Kim; Balshaw, David; Cui, Yuxia; Dunton, Genevieve; Hoppin, Jane A; Koutrakis, Petros; Jerrett, Michael

2017-03-20

The exposome comprises all environmental exposures that a person experiences from conception throughout the life course. Here we review the state of the science for assessing external exposures within the exposome. This article reviews (a) categories of exposures that can be assessed externally, (b) the current state of the science in external exposure assessment, (c) current tools available for external exposure assessment, and (d) priority research needs. We describe major scientific and technological advances that inform external assessment of the exposome, including geographic information systems; remote sensing; global positioning system and geolocation technologies; portable and personal sensing, including smartphone-based sensors and assessments; and self-reported questionnaire assessments, which increasingly rely on Internet-based platforms. We also discuss priority research needs related to methodological and technological improvement, data analysis and interpretation, data sharing, and other practical considerations, including improved assessment of exposure variability as well as exposure in multiple, critical life stages.

Analysis of Students' Conceptions of Basic Magnetism from a Complex Systems Perspective

NASA Astrophysics Data System (ADS)

Lemmer, Miriam; Kriek, Jeanne; Erasmus, Benita

2018-03-01

This study established whether 12 South African secondary school physics students had incorrect conceptions of basic magnetism and if they had, to what extent they consistently applied such conceptions. Different scenarios in the form of thought experiments were presented in a clinical interview approach. A complex systems perspective underpinned the study and was firstly used to analyze 12 students' conceptions in terms of intuitive fragments of knowledge elements, structured misconceptions, and theory-like system of knowledge elements. Secondly, coherence in each student's ideas expressed across ten themes using thought experiments was analyzed in an effort to determine variations or coherence in responses. Examples of student explanations and sketches are discussed in the paper to illustrate the conceptual structures they applied. Most of the students in this study used a variety of knowledge elements in accord with a complex systems perspective, but three students seemed to prefer a specific perspective. One student's ideas tended to be mainly fragmented, a second exposed a number of structured misconceptions, while another student's reasoning can be described as a theory-like system of knowledge elements. Accordingly, the emphasis of physics education research should no longer be on the compilation of a list of misconceptions that have to be remedied or replaced, but on the conceptual connections, students make and their associative reasoning patterns (i.e., knowledge systems revealed). It remains for the teacher to use the complex systems perspective as a framework to facilitate students' conceptual development and understanding, proceeding on their existing knowledge systems.

Non-targeted and delayed effects of exposure to ionizing radiation: II. Radiation-induced genomic instability and bystander effects in vivo, clastogenic factors and transgenerational effects

NASA Technical Reports Server (NTRS)

Morgan, William F.

2003-01-01

The goal of this review is to summarize the evidence for non-targeted and delayed effects of exposure to ionizing radiation in vivo. Currently, human health risks associated with radiation exposures are based primarily on the assumption that the detrimental effects of radiation occur in irradiated cells. Over the years a number of non-targeted effects of radiation exposure in vivo have been described that challenge this concept. These include radiation-induced genomic instability, bystander effects, clastogenic factors produced in plasma from irradiated individuals that can cause chromosomal damage when cultured with nonirradiated cells, and transgenerational effects of parental irradiation that can manifest in the progeny. These effects pose new challenges to evaluating the risk(s) associated with radiation exposure and understanding radiation-induced carcinogenesis.

The GED4GEM project: development of a Global Exposure Database for the Global Earthquake Model initiative

USGS Publications Warehouse

Gamba, P.; Cavalca, D.; Jaiswal, K.S.; Huyck, C.; Crowley, H.

2012-01-01

In order to quantify earthquake risk of any selected region or a country of the world within the Global Earthquake Model (GEM) framework (www.globalquakemodel.org/), a systematic compilation of building inventory and population exposure is indispensable. Through the consortium of leading institutions and by engaging the domain-experts from multiple countries, the GED4GEM project has been working towards the development of a first comprehensive publicly available Global Exposure Database (GED). This geospatial exposure database will eventually facilitate global earthquake risk and loss estimation through GEM’s OpenQuake platform. This paper provides an overview of the GED concepts, aims, datasets, and inference methodology, as well as the current implementation scheme, status and way forward.

Is an ecosystem services-based approach developed for setting specific protection goals for plant protection products applicable to other chemicals?

PubMed

Maltby, Lorraine; Jackson, Mathew; Whale, Graham; Brown, A Ross; Hamer, Mick; Solga, Andreas; Kabouw, Patrick; Woods, Richard; Marshall, Stuart

2017-02-15

Clearly defined protection goals specifying what to protect, where and when, are required for designing scientifically sound risk assessments and effective risk management of chemicals. Environmental protection goals specified in EU legislation are defined in general terms, resulting in uncertainty in how to achieve them. In 2010, the European Food Safety Authority (EFSA) published a framework to identify more specific protection goals based on ecosystem services potentially affected by plant protection products. But how applicable is this framework to chemicals with different emission scenarios and receptor ecosystems? Four case studies used to address this question were: (i) oil refinery waste water exposure in estuarine environments; (ii) oil dispersant exposure in aquatic environments; (iii) down the drain chemicals exposure in a wide range of ecosystems (terrestrial and aquatic); (iv) persistent organic pollutant exposure in remote (pristine) Arctic environments. A four-step process was followed to identify ecosystems and services potentially impacted by chemical emissions and to define specific protection goals. Case studies demonstrated that, in principle, the ecosystem services concept and the EFSA framework can be applied to derive specific protection goals for a broad range of chemical exposure scenarios. By identifying key habitats and ecosystem services of concern, the approach offers the potential for greater spatial and temporal resolution, together with increased environmental relevance, in chemical risk assessments. With modifications including improved clarity on terminology/definitions and further development/refinement of the key concepts, we believe the principles of the EFSA framework could provide a methodical approach to the identification and prioritization of ecosystems, ecosystem services and the service providing units that are most at risk from chemical exposure. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Wearable camera-derived microenvironments in relation to personal exposure to PM2.5.

PubMed

Salmon, Maëlle; Milà, Carles; Bhogadi, Santhi; Addanki, Srivalli; Madhira, Pavitra; Muddepaka, Niharika; Mora, Amaravathi; Sanchez, Margaux; Kinra, Sanjay; Sreekanth, V; Doherty, Aiden; Marshall, Julian D; Tonne, Cathryn

2018-05-17

Data regarding which microenvironments drive exposure to air pollution in low and middle income countries are scarce. Our objective was to identify sources of time-resolved personal PM 2.5 exposure in peri-urban India using wearable camera-derived microenvironmental information. We conducted a panel study with up to 6 repeated non-consecutive 24 h measurements on 45 participants (186 participant-days). Camera images were manually annotated to derive visual concepts indicative of microenvironments and activities. Men had slightly higher daily mean PM 2.5 exposure (43 μg/m 3 ) compared to women (39 μg/m 3 ). Cameras helped identify that men also had higher exposures when near a biomass cooking unit (mean (sd) μg/m 3 : 119 (383) for men vs 83 (196) for women) and presence in the kitchen (133 (311) for men vs 48 (94) for women). Visual concepts associated in regression analysis with higher 5-minute PM 2.5 for both sexes included: smoking (+93% (95% confidence interval: 63%, 129%) in men, +29% (95% CI: 2%, 63%) in women), biomass cooking unit (+57% (95% CI: 28%, 93%) in men, +69% (95% CI: 48%, 93%) in women), visible flame or smoke (+90% (95% CI: 48%, 144%) in men, +39% (95% CI: 6%, 83%) in women), and presence in the kitchen (+49% (95% CI: 27%, 75%) in men, +14% (95% CI: 7%, 20%) in women). Our results indicate wearable cameras can provide objective, high time-resolution microenvironmental data useful for identifying peak exposures and providing insights not evident using standard self-reported time-activity. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Two mothers and a donor: exploration of children’s family concepts in lesbian households

PubMed Central

Raes, I.; Van Parys, H.; Provoost, V.; Buysse, A.; De Sutter, P.; Pennings, G.

2015-01-01

Background: Although children from lesbian families appear to make a distinction between a residential father and a donor, defining these two concepts seems to be a challenge. They need to appeal to more familiar concepts such as the hetero-normative concept of ‘mother’ to give a definition of the unfamiliar concepts they are confronted with. Methods: The study is based on qualitative in-depth interviews with 6 children (9-10 years old) from lesbian families, all of which have been conceived using anonymous sperm donation. Semi-structured interviews were conducted. Results: Two findings stand out. First, in defining the concepts of biological and non-biological mother, both mothers were described as equal parents. No difference was attached by the children to the mothers’ position as a parent. Second, the concepts ‘non-biological mother’ and ‘donor’ were defined by looking at the hetero-normative concepts of ‘mummy’ and ‘daddy’. To define the non-biological mother, both a ‘mummy’ and a ‘daddy’ were used as a reference. To define the donor concept, often references were made to a daddy. This comparison with a ‘daddy’ turned out to be complex due to the conflict between the role as a progenitor and the lack of a social relationship. The lack of language surrounding this concept turned out to be difficult. Wider implications of the findings: This study illustrates the complexity and ambiguity of children‘s experiences and perceptions when dealing with issues related to genetic and social parenthood. PMID:26175886

Against compassion: in defence of a "hybrid" concept of empathy.

PubMed

Morgan, Alastair

2017-07-01

In this article, I argue that the recent emphasis on compassion in healthcare practice lacks conceptual richness and clarity. In particular, I argue that it would be helpful to focus on a larger concept of empathy rather than compassion alone and that compassion should be thought of as a component of this larger concept of empathy. The first part of the article outlines a critique of the current discourse of compassion on three grounds. This discourse naturalizes, individualizes, and reifies compassion leading to a decontextualized and simplified understanding of failures in healthcare practice. The second part uses resources from phenomenology and contemporary moral philosophy to construct a "hybrid" concept of empathy that includes both pre-reflective/intuitive and cognitive/imaginative components. This "hybrid" concept of empathy leads to a more complex understanding of the multiple responses to others' distress. I conclude that there are no straightforward normative naturalistic responses to others' distress. Rather than conceptualizing compassion as a naturalistic impulse or a character-based trait, we need to consider the complexity of our empathic recognition of vulnerable others. © 2016 John Wiley & Sons Ltd.

The Concept of Oxidation States in Metal Complexes

ERIC Educational Resources Information Center

Steinborn, Dirk

2004-01-01

The concepts of oxidation numbers when applied means electrons that are shared between atoms in molecules are assigned to a specific atom. Oxidation numbers are assigned from the Lewis structure of a molecule, with knowledge of the electronegativities of elements.

STARTING SMALL IN STELLA: LEARNING HOW TO PLAN FOR SUSTAINABILITY

EPA Science Inventory

Concepts of sustainability are rarely clearly defined and their applications often seem abstract. Because these concepts must address systems scale, even simple strategies often seem complex, abstract, and overwhelming. The opportunity to apply a theory for sustainable developmen...

Analyses of rear-end crashes based on classification tree models.

PubMed

Yan, Xuedong; Radwan, Essam

2006-09-01

Signalized intersections are accident-prone areas especially for rear-end crashes due to the fact that the diversity of the braking behaviors of drivers increases during the signal change. The objective of this article is to improve knowledge of the relationship between rear-end crashes occurring at signalized intersections and a series of potential traffic risk factors classified by driver characteristics, environments, and vehicle types. Based on the 2001 Florida crash database, the classification tree method and Quasi-induced exposure concept were used to perform the statistical analysis. Two binary classification tree models were developed in this study. One was used for the crash comparison between rear-end and non-rear-end to identify those specific trends of the rear-end crashes. The other was constructed for the comparison between striking vehicles/drivers (at-fault) and struck vehicles/drivers (not-at-fault) to find more complex crash pattern associated with the traffic attributes of driver, vehicle, and environment. The modeling results showed that the rear-end crashes are over-presented in the higher speed limits (45-55 mph); the rear-end crash propensity for daytime is apparently larger than nighttime; and the reduction of braking capacity due to wet and slippery road surface conditions would definitely contribute to rear-end crashes, especially at intersections with higher speed limits. The tree model segmented drivers into four homogeneous age groups: < 21 years, 21-31 years, 32-75 years, and > 75 years. The youngest driver group shows the largest crash propensity; in the 21-31 age group, the male drivers are over-involved in rear-end crashes under adverse weather conditions and the 32-75 years drivers driving large size vehicles have a larger crash propensity compared to those driving passenger vehicles. Combined with the quasi-induced exposure concept, the classification tree method is a proper statistical tool for traffic-safety analysis to investigate crash propensity. Compared to the logistic regression models, tree models have advantages for handling continuous independent variables and easily explaining the complex interaction effect with more than two independent variables. This research recommended that at signalized intersections with higher speed limits, reducing the speed limit to 40 mph efficiently contribute to a lower accident rate. Drivers involved in alcohol use may increase not only rear-end crash risk but also the driver injury severity. Education and enforcement countermeasures should focus on the driver group younger than 21 years. Further studies are suggested to compare crash risk distributions of the driver age for other main crash types to seek corresponding traffic countermeasures.

Cross-cultural differences in meter perception.

PubMed

Kalender, Beste; Trehub, Sandra E; Schellenberg, E Glenn

2013-03-01

We examined the influence of incidental exposure to varied metrical patterns from different musical cultures on the perception of complex metrical structures from an unfamiliar musical culture. Adults who were familiar with Western music only (i.e., simple meters) and those who also had limited familiarity with non-Western music were tested on their perception of metrical organization in unfamiliar (Turkish) music with simple and complex meters. Adults who were familiar with Western music detected meter-violating changes in Turkish music with simple meter but not in Turkish music with complex meter. Adults with some exposure to non-Western music that was unmetered or metrically complex detected meter-violating changes in Turkish music with both simple and complex meters, but they performed better on patterns with a simple meter. The implication is that familiarity with varied metrical structures, including those with a non-isochronous tactus, enhances sensitivity to the metrical organization of unfamiliar music.

Chaos, Complexity, Learning, and the Learning Organization: Towards a Chaordic Enterprise

ERIC Educational Resources Information Center

van Eijnatten, Frans M.; Putnik, Goran D.

2004-01-01

In order to set the stage for this special issue, the prime concepts are defined: i.e. "chaos," "complexity," "learning" (individual and organizational), "learning organization," and "chaordic enterprise". Also, several chaos-and-complexity-related definitions of learning and learning organizations are provided. Next, the guest editors' main…