Top PDF The Fundamentals of Longitudinal Research: An Overview

The Fundamentals of Longitudinal Research: An Overview

The Fundamentals of Longitudinal Research: An Overview

One of the surprising puzzles in social science research is that researchers seem to need more (and ‘better’) data even as more and more data are being collected. Policy research in particular needs an integrated and coherent data system for making any realistic inferences. Different surveys tap on different information and all these data need to be integrated and ‘matched’ for meaningful research on development. (See LeBourdais’ reflections above) One of the recent state-of-the- art approaches to meeting these demands in the social sciences (an old art in the physical sciences though) is the technique of microsimulation modeling. Douglas Wolf shares with us his experiences of using microsimulation techniques and shows how useful it can be for model builders. Among the many models suitable for longitudinal data, he selects those models that are often used in demographic applications: Models of duration and of sequences, failure-time (hazard) models, as well as linear models for continuous and discrete outcomes, and shows how microsimulation can be done for these models. The point that he emphasizes in this paper echoes Burch’s reflections – see above): Models should be taken seriously. Pointing out the various other uses of microsimulation and advantages and disadvantages of using microsimulation, he addresses one of the particularly useful areas mentioned in an earlier section, namely the problem of missing data. For lack of space, it was not possible to include illustrations for the different procedures that Wolf suggests in this paper, but extensive references to other research works that have used these procedures should be helpful to those who are interested in using this handy tool.
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Chemistry Inspired by the Colors of Fruits, Flowers and Wine

Chemistry Inspired by the Colors of Fruits, Flowers and Wine

An overview is provided of the status of research at the frontiers of investigation of the chemistry and photochemistry of two classes of natural plant pigments, the anthocyanins and the betalains, as well as of the pyranoanthocyanin pigments formed from anthocyanins during the maturation of red wine. Together, anthocyanins and betalains are responsible for almost all of the red, purple and blue colors of fruits and flowers and anthocyanins and pyranoanthocyanins are major contributors to the color of red wines. All three types of pigments are cationic below about pH 3, highly colored, non-toxic, reasonably soluble in water or alcohol and fairly stable to light. They exhibit good antioxidant or antiradical activity and, as part of our diet, confer a number of important health benefits. Systematic studies of model compounds containing the basic chromophoric groups of these three types of pigments are providing a deeper understanding of the often complex chemistry and photochemistry of these pigments and their relationship to the roles in vivo of these pigments in plants. These natural pigments are currently being exploited as starting materials for the preparation of novel semi-synthetic dyes, pigments and fluorescence probes.
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An overview of three decades of mergers and acquisitions research

An overview of three decades of mergers and acquisitions research

Acquirer firms often pay large acquisition premiums on the acquired firms not only because they expect to recoup the investment via synergies (Hitt, Ireland & Harrison, 2001) but due to other reasons. Through M&A deals, firms may arguably augment their market power (Chatterjee, 1986) and redeploy assets and resources to more productive uses. Acquiring a new firm may allow the acquirer to generate economies of scale and scope, combining trademarks and workforces (e.g. in manufacturing and sales) and using concurrent distribution channels (Rumelt, 1974; Capron, 1999) to reduce costs and build (or reinforce) a competitive advantage (Barney, 1991; Capron, 1999). Therefore, firms arguably pay acquisition premiums to capture these synergies insofar as the premium does not exceed the potential synergy (Sirower, 1997). Another reason for acquisition premiums is the opportunistic behavior of the managers which use M&A deals to obtain personal gains (e.g. employment risk reduction, executive compensation and power increase) (Hitt et al., 2012). The managerial hubris (Roll, 1986) – where executives’ overconfidence in creating synergies
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An overview of the contribution of studies with cladocerans to environmental stress research

An overview of the contribution of studies with cladocerans to environmental stress research

Based on these recent results with cladocerans, we propose a simplified conceptual model of the effects of multiple stressors (Figure 4), considering a scenario of exposure of the organism to two stressors sequentially and cumulatively. This scenario is representative, for example, of a coastal lagoon with fluctuating HSs content and subject to occasional salinity increases due to marine intrusions and storms (Caliman et al., 2010). The shaded area in the graph represents the combinations of intensities of both stressors upon which the organism would not benefit from the exposure to the first stressor for acquiring resistance against the second one. Under those conditions, the upcoming energetic demands are overwhelming in the final balance, and this is the scenario most commonly found in studies on stress, with synergistic detrimental effects of multiple stressors. Above a certain intensity of the first stressor, this would be by itself too harsh, not rendering the organisms more resistant to further stressors (Figure  4). The dotted area represents the combinations of intensities where the first stressor would be efficient in promoting resistance against the second one, due to the “training” of stress defense systems (Figure  4). This pattern would be closely related to the phenomenon of hormesis, which describes positive effects of toxic compounds and other stressors at low doses to fitness parameters, while detrimental effects show up with the progressive dose increase (Calabrese & Baldwin, 2003). The positive effects of the first stressor would take place only above a threshold intensity, bellow which this stressor would not be effective in stimulating the stress defense systems (white area, Figure 4). In general, the higher the intensity of the second stressor, the less likely are the beneficial effects (i.e., stress resistance) against the second one (narrowing of the dotted region, Figure 4), irrespective of the intensity of the first stressor. The dotted area in the graph represents the situations where mild stress—which is certainly a present factor at environmentally realistic Figure 4. A conceptual model of the overall effects of
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PKM: A pendulum for consultative-relational selling

PKM: A pendulum for consultative-relational selling

Marketing and knowledge management convergence is a key trend of 21 st century competitive business environment, in which, key account managers play an important strategic organisational role due to their blended expertise: technical (organisational and personal knowledge) and relational (trust and ethical behaviour). Although it remains a mystery how their personal knowledge is a key assumption for achieving long term results with customers, namely in consultative-relational selling. This manuscript aims to explore the importance of personal knowledge management in consultative-relational selling (pendulum), and to promote a plausible justification the authors will shed some light over Aureliano Pinheiro MPhil research project (consultative-relational selling influence over customer loyalty in Portuguese luxury hotels and resorts). Thus, the paper recognizes seven sections: research project (aims and objectives, as well as, framing the discussion); case study (an overview, role of theory and role of researcher); customer loyalty (concept and the bond to selling); consultative sale (concept, technical issues and relational issues); relational selling (concept, trust and ethical behaviour); personal knowledge management; pendulum; a metaphorical discussion (the pendulum metaphor and empirical evidences).
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Ciênc. saúde coletiva  vol.13 número6

Ciênc. saúde coletiva vol.13 número6

asthma in the past three decades it has also be- come clear that it is a socially patterned disease, based on demographic and socioeconomic indica- tors clustered by areas of residence. This trend is not readily explained by traditional genetic para- digms or physical environmental exposures when considered alone. This has led to consideration of the interplay among physical and psychosocial en- vironmental hazards and the molecular and ge- netic determinants of risk (i.e., biomedical fram- ing) within the broader socioenvironmental con- text including socioeconomic position as an up- stream “cause of the causes” (i.e., ecological fram- ing). Transdisciplinary research strategies or pro- gram s that em brace this com plexity through a shared conceptual framework that integrates di- verse discipline-specific theories, models, measures, and analytical methods into ongoing asthma re- search may contribute most significantly toward furthering our understanding of socially patterned disease. This paper provides an overview of a mul- tilevel, multimethod longitudinal study, the Asth- ma Coalition on Community, Environment and Social Stress (ACCESS), as a case study to exem- plify both the opportunities and challenges of transdisciplinary research on urban asthma ex- pression in the United States.
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Research on eggshell structure and quality: An historical overview

Research on eggshell structure and quality: An historical overview

Getting the calcium to the laying hen Until the late 1960’s most of the calcium was provided to layers as finely ground limestone. This was cheap to buy, and easily incorporated into layer feeds. At this time, the hens laid at least 15% less than today’s flocks. But even then, producers were beginning to experience shell quality problems. In the 1960’s, Scott and colleagues at Cornell University showed that calcium carbonate supplied in the form of oyster shells was more effective than the same amount of calcium from finely ground limestone (Scott et al., 1971). The reason for this was that the larger particles of the oyster shells took longer to digest, and more was absorbed into the blood stream than from the limestone. Subsequent research showed that hens would seek out oyster shells or large calcium particles late in the day, prior to the most rapid period of shell formation (which mostly occurs during the night, when feed is not consumed) and thus provide themselves with a continuous supply of calcium when it was most needed.
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Invited Review Physiological responses of growing pigs to high ambient temperature andor inflammatory challenges

Invited Review Physiological responses of growing pigs to high ambient temperature andor inflammatory challenges

ABSTRACT - Global warming is one of the major environmental threats facing the world in the 21st century. This fact will have a significant impact on pig production due to its direct effects on welfare, health, and performance of pigs. Besides, the effects of high temperatures will presumably become more important over the next decades due to the development of pig production in developing countries mainly located in tropical and subtropical areas, where animals are often exposed to ambient temperatures above their thermal comfort zone. Furthermore, pigs reared in tropical areas are often confronted to sanitary challenges including poor hygiene conditions, lack of respect for sanitary rules, and pathogens. This results in the stimulation of the immune system and, as a consequence, in the production of pro-inflammatory cytokines and neuroendocrine adjustments that, in turn, usually have a negative impact on growth and feed efficiency. Although the effects of high ambient temperature and disease on pig physiology and performance have been well documented in literature, little is known about the associated effects of both factors. This understanding may contribute to a better quantification and comprehension of the physiological and metabolic disturbances occurring in practical conditions of pig production in tropical areas and, more generally, in many other geographic areas that will be influenced by the perspective of global warming. Therefore, the objective of this work is to provide an overview of recent research advances on the physiological responses of growing pigs during acclimation to high ambient temperature and on the potential effects of high ambient temperature on the ability of growing pigs to resist, cope with, or recover from an inflammatory challenge.
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Braz. J. Pharm. Sci.  vol.46 número4

Braz. J. Pharm. Sci. vol.46 número4

The plant of the genus Pterodon (Fabaceae, Leguminosae), commonly known as ‘sucupira’ or ‘faveira’, are disseminated throughout the central region of Brazil and has frequently been used in popular medicine for its anti-rheumatic, analgesic, and anti-inlammatory properties. In recent years, interest in these plants has increased considerably. The biological effects of different phytoextracts and pure metabolites have been investigated in several experimental models in vivo and in vitro. The literature describes lavonoids, triterpene and steroids, while one paper presented studies with proteins isolated from the genus. This review provides an overview of phytochemical and pharmacological research in Pterodon, showing the main chemical compounds studied to date, and focusing on the relationship between these molecules and their biological activity. Furthermore, this study paves the way for more in-depth investigation, isolation and characterization of the molecules of this plant genus.
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Rev. Bras. Saude Mater. Infant.  vol.14 número4

Rev. Bras. Saude Mater. Infant. vol.14 número4

This participation of all is extremely important, since care with regard to the methods used for scientific in- vestigation and the publication of new proposals or reviews of the subject are always necessary for the ad- vancement of knowledge. An investigation of this subject is particularly apposite at this point in time. In fact, an overview of the literature on the adequate use of research methods in the field of health reveals countless questions that lead us to reflect on the importance of methodological quality for the execution and analysis of every study, which is a fundamental element for consistency and later clear dissemination. And there are more than a few problems in this area.
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The modest but growing Brazilian presence in psychiatric, psychobiological and mental health research: assessment of the 1998-2002 period

The modest but growing Brazilian presence in psychiatric, psychobiological and mental health research: assessment of the 1998-2002 period

The increase in medical research produc- tion has been followed by an increased num- ber of citations of Brazilian papers. The number of citation of Brazilian articles in Psychiatry/Psychology has been rising steadily in the last decade; it was 320 during the 1993-1997 period and increased to 740 during the 1998-2002 period (7). Brazil leads scientific production in Latin America and ranks twenty-eighth in the ISI Psychiatry/ Psychology section (7). Although Brazil’s leading position in Latin America is evident, countries such as Mexico and Chile seem to be more efficient regarding the investment they receive for research (12). Chilean and Mexican per capita investment in science and technology is lower than the Brazilian investment, so the per capita cost of a high- quality article is lower, suggesting that these investments are more cost-effective (11). In our study, the variability of productivity in- dexes among GPs suggests that there is room for improvement in terms of research ad- viser productivity. Data regarding grant re- sources would allow calculations of the cost- effectiveness of the GPs’ scientific produc- tion, providing a better overview of the sys- tem. Accreditation of graduate research ad- visers has changed during the last few years. There is now a more stringent criterion based on the quality and quantity of the scientific production. As a consequence, the GPs are
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AN OVERVIEW ON THE BRAZILIAN ORANGE JUICE PRODUCTION CHAIN

AN OVERVIEW ON THE BRAZILIAN ORANGE JUICE PRODUCTION CHAIN

ABSTRACT - Brazil is the world’s largest producer of oranges and uses more than 70% of the harvested fruits in the production of juices. The amount of processed orange is growing about 10% per year, confirming the trend of the Brazilian citrus for juice production. This research aimed to investigate the Brazilian orange juice production chain from 2005 to 2009. Data from the amount of frozen juice produced and exported, international price of orange juice, and intermediate transactions were assessed in order to make possible selection of all interveners involved in the chain. The study using the Social Network Analysis (SNA) showed that the densest relationships in the network are from exporters to importers and from orange growers to the orange processing industry. No difference was found in the values of the network geodesic distance or the clustering coefficients from 2005 to 2009. The degree of centrality increased steadily throughout the years indicating that the processing industry attempts to minimize the risks by centralizing the actions. A decrease in export of orange juice from 2007 (2.07 10 6 t) to 2008 (2.05 10 6 t) was found, probably due to the world’s
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An overview of the Brazilian natural product community.

An overview of the Brazilian natural product community.

No domínio das substâncias voláteis é expressivo o número de artigos de pesquisadores brasileiros publicados no Journal of Essential Oil Research (~10%) e no Flavour Fragrance and Journal (~8%). Por outro lado, dada a sua especificidade, este domínio é pouco re- presentativo no JBCS e na QN. Há uma tradição no estudo de óleos essenciais no Pará, cujo grupo estava anteriormente no estado do Amazonas e no Ceará. Observa-se ainda um número significativo de artigos do Rio Grande do Sul e Ceará. Tanto na QN como no JBCS o número de trabalhos publicados sobre a determinação da consti- tuição de óleos essenciais e de compostos voláteis, em geral, é redu- zido, face ao número de artigos que são publicados por pesquisado- res brasileiros no FFJ e no JEOR. Neste campo o Brasil está bem representado, até mesmo pelo potencial de sua flora odorífera, uma das mais pujantes do planeta.
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READING RESEARCH AND DIGITAL READING RESEARCH: an overview of the current scientific scenario

READING RESEARCH AND DIGITAL READING RESEARCH: an overview of the current scientific scenario

ABSTRACT: Historically, Reading Research has always been a broad and multidisciplinary research field, motivated by the complexity of the act of reading. Based on a review of the literature, the aim of this paper is to provide a current overview of Reading Research, starting from the study of new factors that have influenced the growth of this field. To this end, a bibliometric analysis was carried out, focusing on four main points: areas of knowledge; the most prolific authors; the contrast between Reading Research and Digital Reading Research; and the main topic areas being studied. The methodology used involves an extensive collection of data originating from different sources, data analyses, the calculation of efficiency rates and the solutions used to the address disparity in the amount and type of data found. This study confirms that the onset of the use of technological devices for reading stimulated the growth of Reading Research. Since 2009, when the use of the Kindle e-reader (Amazon) stabilized, preceding the launch of the iPad tablet (Apple) in 2010, digital reading played an important role in Reading Research, attracting new topics and research prospects.
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An Overview of Current Research on Automated Essay Grading

An Overview of Current Research on Automated Essay Grading

chiarelli, & Panti., 2002) more than forty commercial CbAS are currently available on the ma rket. Most of those tools are based on the use of the so-called objective-type questions: i.e. multiple choice, multi- ple answer, short answer, selection/association, hot spot and visual identification (Valenti et al., 2000). Most researchers in this field agree on the thesis that some aspects of complex achievement are difficult to measure using objective-type questions. Learning outcomes implying the ability to recall, organize and integrate ideas, the ability to express oneself in writing and the ability to supply merely than identify interpretation and application of data, require less structuring of response than that imposed by objective test items (Gronlund, 1985). It is in the measurement of such outcomes, corresponding to the higher lev- els of the Bloom’s (1956) taxonomy (namely evaluation and synthesis) that the essay question serves its most useful purpose.
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Fundamentals of Implementation Science: an intensive course on an emerging field of research

Fundamentals of Implementation Science: an intensive course on an emerging field of research

The DeWorm3 Hybrid Trial, presented during the course, exemplifies an ongoing hybrid study that, given the global epidemiological profile of the estimated 1.5 billion people infected with soil-transmitted helminths (STH), whose persistent infections can lead to malnutrition and anemia, resulting in the physical and cognitive delay of children and reduced productivity and income generation in adults, seeks to develop a viable and effective approach that uses a plan to interrupt the transmission of STH on a large scale. Such a plan will be an IS strategy in countries such as Malawi, India, Benin, Kenya, and others, based on studies demonstrating strategies different from current WHO guidelines, which recommends treating school children annually in places where STH prevalence falls by 20 % and 50%, and biannually where it exceeds 50%. 22
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Image Information Retrieval: An Overview of Current Research

Image Information Retrieval: An Overview of Current Research

Most of the research in visual information seeking behavior and use has been conducted in non-digitized collections with written or verbal queries. The seminal work in this area was conducted by Enser (1993) who analyzed nearly 3000 written requests from 1000 request forms at the Hulton Deutsch ar- chive. Results indicated that queries for visual materials ex- hibited a greater level of specificity than requests for textual materials, and that the majority of requests were for specific instances of a general category ("London Bridge" rather than the generic "Bridges"). Armitage and Enser (1997) extended this research by categorizing requests across seven picture archives. Their work resulted in a framework for queries with 4 main categories (who, what, when, where) and 3 levels of abstraction (specific, generic, abstract). Similarly, Keister's (1994) analysis of query logs at the National Library of Medi- cine demonstrated that most queries were structured using both abstract concepts as well as concrete image elements. She concluded that the aesthetic and emotional needs of the user are highly subjective and do not lend themselves to in- dexing.
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An overview on the treatment of postmenopausal osteoporosis

An overview on the treatment of postmenopausal osteoporosis

Intermittent administration of low-dose PTH enhances osteoblast activity and bone formation. Two PTH pep- tides have been approved for the treatment of osteo- porosis: teriparatide (PTH 1-34) and PTH 1-84, but only teriparatide is available in Brazil. It is administered as a 20-mcg subcutaneous daily injection. There was a 65% and 54% reduction in fracture risk in vertebral and non-vertebral fractures. Due to a small number of hip fractures, no signiicant fracture risk reduction was demonstrated (53). The concomitant use of bisphos- phonates may attenuate bone mass improvement seen with PTH alone, but the administration of an anti-re- sorptive agent has to be considered after the treatment in order to maintain the bone gain achieved (54). Max- imum treatment duration of 2 years is recommended because preclinical studies showed the development of osteosarcoma in rats (53). Asymptomatic hypercal- cemia, occasional nausea, dizziness, leg cramps, and headache were associated with teriparatide use. Teripa- ratide is contraindicated in clinical situations with high risk of osteosarcoma, such as children and adolescents, Paget’s disease, bone metastasis, skeletal irradiation, or unexplained elevations of alkaline phosphatase. The use of teriparatide is limited to severe osteoporosis because of the high cost of the treatment.
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SOCIAL ECONOMY – A FORM OF INCLUSION AND OF ''REACTIVATING'' OF LABOR IN THE CONTEXT OF THE CURRENT CRISIS

SOCIAL ECONOMY – A FORM OF INCLUSION AND OF ''REACTIVATING'' OF LABOR IN THE CONTEXT OF THE CURRENT CRISIS

Despite the exigencies of the European Union regarding the active inclusion , which means to ensure labor markets for those looking for a job and for the disadvantaged persons , in several countries Greece, Ţortugal, Romania, etc. some passive policies were promoted, resource consuming, outside the system of social economy, that have aggravated the local crises and have extended the global crisis of the current society European Commission , p. .

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A Method To Find The Area Of Sector Without The Usage Of Angle Made By The Chord

A Method To Find The Area Of Sector Without The Usage Of Angle Made By The Chord

The two points considered at the alternate sides, of the tangents through the diameter of the circle, and then the line joining these points divides the circle in the ratio of the distances between the considered points to the points of contacts.

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