bluuebunny/crossref_metadata_2025 huggingface dataset:
Advances in precision agriculture in south-eastern Australia. IV. Spatial variability in plant-available water capacity of soil and its relationship with yield in site-specific management zones
Authors: Rab M. A. , Fisher P. D. , Armstrong R. D. , Abuzar M. , Robinson N. J. , Chandra S.
Published: September 2009

Spatial variability in grain yield can arise from variation in many different soil and terrain properties. Identification of important sources of variation that bear significant relationship with grain yield can help achieve more effective site-specific management. This study had three aims: (i) a geostatistical description/modelling of the paddock-level spatial structure in variability of plant-available water capacity (PAWC) and related soil properties, (ii) to determine optimal number of management zones in the paddock, and (iii) to assess if the variability in PAWC and related soil properties is significantly associated with the variability in grain yield across the management zones. Particle size distribution, bulk density (BD), field capacity (FC), permanent wilting point (PWP), and soil water content (SWC) at sowing were measured at 4 soil depths (to 0.60 m) at 50 representative spatial sampling locations across a paddock near Birchip (Victoria). PAWC and plant-available water at sowing (PAWs) were derived from these data. Moderate to strong spatial dependence across the paddock was observed. The magnitude of the structural variation and of range varied widely across different soil properties and depths. The south-east edge and the central areas of the paddock had higher clay content, FC, PWP, PAWC, and lower PAWs. The paddock was divided into 6 potential management zones using combined header yield and normalised difference vegetation index (NDVI). The adequacy of zoning was evaluated using relative variability (RV) of header yield and soil properties. The mean RV for 3 zones differed little from that of 6 management zones for header yield and for each measured soil property, indicating division of the paddock into 3 zones to be adequate. The results from residual maximum likelihood (ReML) analysis showed that low yield zones had significantly higher clay content, FC, PWP, SWC, and PAWC and significantly lower PAWs than both medium and high yield zones. The mean FC, PWP, and PAWC in the low yield zones were, respectively, 25%, 26%, and 28% higher, and PAWs 36% lower than their corresponding values in the high yield zones. Linear regression analysis indicated that 59–96% of the observed variation in grain yield across management zones could be explained by variation in PWP. The practical implications of these results are discussed.
Does re-vegetating poor-performing patches in agricultural fields improve ecosystem function in the northern sandplain of the Western Australian wheatbelt?
Authors: Lawes R. A. , Dodd M. B.
Published: September 2009

There is an impetus to re-vegetate components of the Western Australian wheatbelt to address salinity and improve ecosystem function. In this study we use precision agriculture (PA) technologies and other methods to identify poor-performing patches for three farms, using historical yield maps to assess the ecological value associated with their potential re-vegetation. We also investigate how these patches changed with varying definitions of poor performance. Overall, poor-performing patches were rare and occupied 11.3, 13.5, and 25.3% of farmland across three farms, using the most aggressive definition of poor performance, which included the greatest proportion of arable land. We subsequently assessed the effect that re-vegetating these patches had on a suite of landscape metrics quantifying ecological value. On two farms, mean patch sizes were less than 1.2 ha for all definitions of poor performance. On the third farm, mean patch size increased from 0.9 ha to 2.6 ha as the definition of poor crop performance was altered to include more arable land. Patches were generally small and dispersed, did not significantly enhance connectivity in the landscape, and were therefore of limited ecological value. In general, re-vegetating poor-performing patches alone will provide little ecological benefit when re-vegetation is restricted to unproductive land. The ecological value of re-vegetation strategies in this landscape will improve only if some additional productive agricultural land is also taken out of production and re-vegetated.
Australian primary mental health care: improving access and outcomes
Authors: Fletcher Justine R. , Pirkis Jane E. , Bassilios Bridget , Kohn Fay , Blashki Grant A. , Burgess Philip M.
Published: September 2009

The progressive achievements over time of the Access to Allied Psychological Services (ATAPS) component of the Better Outcomes in Mental Health Care program are examined using a web-based, purpose-designed minimum dataset that collects provider-, consumer- and session-level data on the projects. Findings indicate that the ATAPS projects have established themselves over time as a cornerstone of mental health service provision in Australia. Despite the more recent introduction of the complementary Better Access to Psychiatrists, Psychologists and General Practitioners through the Medicare Benefits Schedule program, the ATAPS projects have continued, since 2001, to attract substantial numbers of general practitioners and allied health professionals and deliver services to significant numbers of consumers. The profile of consumers being referred to the projects is now very consistent, with the majority being women with high prevalence disorders who may have had difficulty accessing mental health care in the past. The nature of sessions being delivered through the projects has also reached a point of consistency, with the majority being individual-level, cognitive behavioural therapy-based sessions of around 1 h in length. The only variation in session delivery is related to the charging of a co-payment. There is good evidence that the projects are achieving positive outcomes for consumers.
β-Catenin promotes respiratory progenitor identity in mouse foregut
Authors: Harris-Johnson Kelley S. , Domyan Eric T. , Vezina Chad M. , Sun Xin
Published: September 2009

The mammalian respiratory system, consisting of both trachea and lung, initiates from the foregut endoderm. The molecular program that instructs endodermal cells to adopt the respiratory fate is not fully understood. Here we show that conditional inactivation of β-
Catenin
(also termed
Ctnnb1
) in foregut endoderm leads to absence of both the trachea and lung due to a failure in maintaining the respiratory fate. In converse, conditional expression of an activated form of β-
Catenin
leads to expansion of
Nkx2.1
, an early marker for the trachea and lung, into adjacent endoderm including the stomach epithelium. Analyses of these mutants show that the loss or gain of trachea/lung progenitor identity is accompanied by an expansion or contraction of esophagus/stomach progenitor identity, respectively. Our findings reveal an early role for β-
Catenin
in the establishment of respiratory progenitors in mouse foregut endoderm.
Iranian Cinema in the Twentieth Century: A Sensory History
Authors: Mottahedeh Negar
Published: September 2009

This essay addresses itself to the century long history of cinema in Iran, focusing on the history of the senses as they combine with and are extended by film technologies. It argues that Khomeini's aim was to produce a transformed and Shi'ite Iran by purifying the sensorial national body by means of film technologies.
The Study of Ancient Iran in the Twentieth Century
Authors: Daryaee Touraj
Published: September 2009

The following article discusses the development of ancient Iranian studies, namely the important philological, archaeological, religious, and historical discoveries in the twentieth century and how they have changed our views of ancient Iran and its impact on modern Iranian identity. The essay also previews the use and abuse of ancient Iranian studies by the state and their focus on the newly discovered Achaemenid Empire at the cost of Arsacid and Sasanian dynasties.
Displaced Masculinity: Gender and Ethnicity among Iranian men in Sweden
Authors: Khosravi Shahram
Published: September 2009

Masculinity, like other kinds of social identity, is an ongoing construction in a dialogue between one's self-image and others' perceptions of one. The interplay between ethnicity and masculinity is a main theme in this article. Due to geographical displacement, the Iranian man's masculine identity has been challenged and renegotiated on the one hand by Iranian women's struggle for emancipation and on the other hand by the Swedish mediawork. Iranian men are displaced from the position of having a powerful gaze, which fixed and controlled women into a position of being an object of the gaze of others. The dominant gaze in Sweden makes them (in)visible in the same way their gaze makes women (in)visible in Iran.
Iranian Studies at the University of Toronto
Authors: Sandler Rivanne
Published: September 2009

The International Society for Iranian Studies (ISIS) fortieth anniversary celebration at the University of Toronto provided an opportunity to research and record the development of Iranian studies at the university. Iranian studies emerged in 1961 as a major sub-field of the newly established Department of Islamic Studies (now the Department of Near and Middle Eastern Civilizations (NMC)). Presently, the university has a diverse and yet cohesive cadre of academic talent and offers a breadth of courses, which makes it unique in Canada. The language-based discipline of an earlier generation of scholars has become the present multi-faceted program of today, addressing a wide variety of academic and community interests. The University of Toronto academic tradition, the scholarship of early faculty, and the immigration of Iranians have contributed to shaping Iranian studies in Toronto.
Pedagogy for knowledge recognition and acquisition: knowing and being at the close of the mechanical age
Authors: Jaros Milan
Published: September 2009

It is the outstanding intellectual challenge of our age to find ways of providing citizens with access to and competent acquisition of the new applications and systems of knowledge. The purpose of this article is twofold. First, it is to justify at the conceptual level that we are facing an unprecedented shift in the way knowledge is generated and acquired, and to draw attention to the specificity of the emerging curricula pathways along which learners and their mentors may respond to this challenge. For this it draws upon the work of Walter Benjamin. Second, the aim is to outline and open for discussion a ‘bottom‐up’ approach to learning and curriculum in higher education that would be complementary to the traditional methods of delivery, and to draw guidelines for bridging the gap between the conceptual ideas and the pragmatic, pedagogical steps needed to implement this approach.
Educational reform, enquiry‐based learning and the re‐professionalisation of teachers
Authors: Williamson Ben , Morgan John
Published: September 2009

This article explores the implications for teacher education and continuous professional development (CPD) of enquiry‐based learning, by drawing specifically on data collected during a four‐year curriculum development and research project, Enquiring Minds (2005–9). Within the partnership approach to curriculum design endorsed by the project, teachers need to demonstrate commitment to the personal narratives of those they teach. Participating teachers have experienced this shift in their practice as a challenge both to their established routines and to their own professional narratives. Furthermore, it has become evident that adopting enquiry‐based practices is at least partly influenced by teachers' own narrative pathways and professional biographies. In particular, some teachers have interpreted their renewed role as preparing children for a ‘high skills’ new media age, while others have developed a more child‐centred focus that draws on their own prior experiences of informal youth work and volunteering. The focus will therefore be on teacher re‐professionalisation in the context of enquiry learning as well as in a policy context where child‐centred ‘enquiry‐based learning’ and a ‘high skills’ economy are in a taut relationship.
Pilot Study of Postexposure Prophylaxis for Hepatitis C Virus in Healthcare Workers
Authors: Corey Kathleen E. , Servoss Julie C. , Casson Deborah R. , Kim Arthur Y. , Robbins Gregory K. , Franzini Jean , Twitchell Katherine , Loomis Susan C. , Abraczinskas Diane R. , Terella Adam M. , Dienstag Jules L. , Chung Raymond T.
Published: September 2009

Background and Objective.

Hepatitis C virus (HCV) transmission occurs in 0.2%-10% of people after accidental needlestick exposures. However, postexposure prophylaxis is not currently recommended. We sought to determine the safety, tolerability, and acceptance of postexposure prophylaxis with peginterferon alfa-2b in healthcare workers (HCWs) exposed to blood from HCV-infected patients.

Design.

Open-label pilot trial of peginterferon alfa-2b for HCV postexposure prophylaxis.

Setting.

TWO academic tertiary-referral centers.

Methods.

HCWs exposed to blood from HCV-infected patients were informed of the availability of postexposure prophylaxis. Persons who elected postexposure prophylaxis were given weekly doses of peginterferon alfa-2b for 4 weeks.

Results.

Among 2,702 HCWs identified with potential exposures to bloodborne pathogens, 213 (7.9%) were exposed to an HCV antibody-positive source. Of 51 HCWs who enrolled in the study, 44 (86%) elected to undergo postexposure prophylaxis (treated group). Seven subjects elected not to undergo postexposure prophylaxis (untreated group). No cases of HCV transmission were observed in either the treated or untreated group, and no cases occurred in the remaining 162 HCWs who did not enroll in this study. No serious adverse events related to a peginterferon alfa-2b regimen were recorded, but minor adverse events were frequent.

Conclusion.

In this pilot study, there was a lower than expected frequency of HCV transmission after accidental occupational exposure. Although peginterferon alfa-2b was safe, because of the lack of HCV transmission in either the treated or untreated groups there is little evidence to support routine postexposure prophylaxis against HCV in HCWs.
Summary of inertial fusion sessions
Authors: Tanaka Kazuo A.
Published: September 2009

Laser and ion beam inertial fusion research has made remarkable progress during the last two years. As a highlight of the 22nd IAEA Fusion Energy Conference among over 30 presentations the National Ignition Facility has been reported for completion as of 27 March 2009 to achieve the first fusion shot within 2010 or 2011 with a central ignition scheme. The LFEX and OMEGA-EP fast ignition lasers have also been completed to start fast ignition feasibility studies as early as in 2009. Relativistic physics revealed many new findings on hot electron energy transport and production. For example, several proposals have been reported to control the hot electron divergence angle. Laser technology has challenged to meet the specification required for fast ignition experiments such as in the LFEX and OMEGA-EP. Target development is making steady progress to be ready for the forthcoming fast ignition integral and ion beam experiments. The LIFE engine (Laser Inertial-Confinement Fusion Fission Energy) was announced from the USA to accelerate the energy production making use of the NIF type fusion outputs in order to prepare for ‘beyond the ignition’ as early as 2020. KOYO-F from Osaka University, Z-machine and HiPER European projects have been reported.
Recent experiments in the EAST and HT-7 superconducting tokamaks
Authors: Wanfor the EAST and HT-7 Teams Baonian
Published: September 2009

First divertor plasma configuration in Experimental Advanced Superconducting Tokamak (EAST) was obtained in the second campaign after the last IAEA meeting. To achieve long pulse diverted plasma discharges, new capabilities including the fully actively water cooled in-vessel components, current drive and heating systems, diagnostics and real-time plasma control algorithm were developed. Pre-programmed shape and feedback control of plasma position and current (RZIP) produced a variety of shaped plasma configurations, covering most of the configurations foreseen at the design stage of the machine. Control algorithm based on real-time equilibrium reconstruction and iso-flux control for the last closed magnetic flux surface (RTEFIT/ISOFLUX) has also been realized. A number of operational issues, such as plasma initiation and ramp up under constraints of superconducting coils were successfully investigated. First LHCD experiments demonstrated long pulse discharges longer than 20 s and nearly full non-inductive current drive. The physical engineering capability on the superconducting magnetic system was assessed by simulating discharges. Since the last IAEA meeting, experiments in HT-7 have been focusing on long pulse operation to support the EAST experiments on both physics and technical aspects. Long pulse discharges up to 400 s have now been achieved in HT-7. Investigation of sawtooth activities in ohmic and LHCD plasmas supports the turbulence model instead of the fast reconnection of the m = 1 magnetic island. Coexistence of electron mode and ion mode in high density ohmic plasmas has been observed by 2D ECE imaging (ECEI) in HT-7. The spectral characteristics of geodesic acoustic mode at the plasma boundary have been investigated by Langmuir probe arrays.
Overview of experimental results on HL-2A
Authors: Duan X.R. , Ding X.T. , Dong J.Q. , Yang Q.W. , Yan L.W. , Liu Yi , Zou X.L. , Liu D.Q. , Xuan W.M. , Chen L.Y. , Rao J. , Song X.M. , Mao W.C. , Wang Q.M. , Cao Z. , Li B. , Cao J.Y. , Lei G.J. , Zhang J.H. , Li X.D. , Wang S.J. , Liu A.D. , Bu M.N. , Chen Y.H. , Chen W. , Cheng J. , Cui C.H. , Cui Z.Y. , Deng Z.C. , Dong Y.B. , Feng B.B. , Gao Q.D. , Han X.Y. , Hong W.Y. , Hu H.T. , Huang M. , Huang Y. , Ji X.Q. , Kang Z.H. , Lan T. , Li G.S. , Li H.J. , Li Qing , Li Qiang , Li W. , Li Y.G. , Li Z.J. , Liu Z.T. , Luo C.W. , Mao X.H. , Pan Y.D. , Peng J.F. , Shao K. , Song X.Y. , Sun H.J. , Wang A.K. , Wang H. , Wang M.X. , Wang Y.Q. , Wang Z.T. , Xiao W.W. , Xiao Z.G. , Xie Y.F. , Yao L.H. , Yao L.Y. , Yu D.L. , Yuan B.S. , Zhao K.J. , Zheng Y.Z. , Zhong G.W. , Zhou C.P. , Zhou J. , Zhou Y. , Yan J.C. , Yu C.X. , Pan C.H. , Liu Yong
Published: September 2009

Significant experimental advances have been made on the HL-2A tokamak along with substantial improvement and development of the hardware. A spontaneous particle transport barrier has been observed in Ohmic discharges without any external momentum input. The barrier was evidenced by a density perturbation study using modulated supersonic molecular beam injection (SMBI) and microwave reflectometry. The new features of the non-local transport effect induced with SMBI have been analysed. The three-dimensional spectral structures of the low frequency zonal flow, the geodesic acoustic mode (GAM) and the quasi-mode-like low frequency fluctuations have been observed simultaneously for the first time. In addition, the spectral structure of the density fluctuations of GAM was also identified. The e-fishbone instability excited by energetic electrons deviated from Maxwellian distribution has been investigated via a 10-channel CdTe hard x-ray detector. It was found that the e-fishbone was correlated with the existence of energetic electrons of 30–70 keV. The MHD experiment has indicated that the suppression of m/n = 2/1 tearing modes may be sustained by ECRH modulation at a frequency of about 10 Hz.
HOPS Interacts with Apl5 at the Vacuole Membrane and Is Required for Consumption of AP-3 Transport Vesicles
Authors: Angers Cortney G. , Merz Alexey J.
Published: September 2009

Adaptor protein complexes (APs) are evolutionarily conserved heterotetramers that couple cargo selection to the formation of highly curved membranes during vesicle budding. In Saccharomyces cerevisiae , AP-3 mediates vesicle traffic from the late Golgi to the vacuolar lysosome. The HOPS subunit Vps41 is one of the few proteins reported to have a specific role in AP-3 traffic, yet its function remains undefined. We now show that although the AP-3 δ subunit, Apl5, binds Vps41 directly, this interaction occurs preferentially within the context of the HOPS docking complex. Fluorescence microscopy indicates that Vps41 and other HOPS subunits do not detectably colocalize with AP-3 at the late Golgi or on post-Golgi (Sec7-negative) vesicles. Vps41 and HOPS do, however, transiently colocalize with AP-3 vesicles when these vesicles dock at the vacuole membrane. In cells with mutations in HOPS subunits or the vacuole SNARE Vam3, AP-3 shifts from the cytosol to a membrane fraction. Fluorescence microscopy suggests that this fraction consists of post-Golgi AP-3 vesicles that have failed to dock or fuse at the vacuole membrane. We propose that AP-3 remains associated with budded vesicles, interacts with Vps41 and HOPS upon vesicle docking at the vacuole, and finally dissociates during docking or fusion.
5. Food consumption, nutrient intake, and the use of food composition tables
Authors: West Clive E. , van Staveren Wija A.
Published: September 2009

This chapter summarizes the approaches to measuring food consumption and nutrient intake at the individual level. It then examines the role of food analysis in determining nutrient intake, and the issues in the development, maintenance, and application of food composition data to estimates of nutrient intake. It touches on missing values, cooking and recipe analysis (and the problems of estimating water losses and vitamin and mineral retention values), and bioavailability. It looks at comparability between databases. Lastly, it summarizes the issues relating to accurate determination of estimates of nutrient intake using databases (such as coding and errors in data entry), and concludes by looking at food groups and food scores, and the limitations of food composition tables and nutrient databases in nutritional epidemiological studies.
16. Experimental studies: clinical trials, field trials, community trials, and intervention studies
Authors: Margetts Barrie M. , Rouse Ian L.
Published: September 2009

Experimental studies set out to alter, rather than just observe, relevant exposures of interest, and to assess over time their impact on health status or disease outcomes. This chapter begins with an historical perspective, and goes on to define experimental studies with tables illustrating the differences between the types of study. This is followed by an outline of the practical approaches to study design, including selection of study populations, allocation of treatment regimes, length of follow up, observer and participant effects, compliance, ascertainment of exposure and outcome, and sample size and power. The chapter concludes with a consideration of analysis and interpretation, some useful variations in design (e.g., factorial designs), and the role of systematic review and meta-analysis.
Disorders associated with high blood pressure
Authors: Swiet Michael de , Leck Ian
Published: September 2009

This chapter discusses measurement of blood pressure as a means of screening for pregnancies that would have adverse outcomes and specifically considers pre-eclampsia. It is not possible to determine the efficacy of blood pressure screening and treatment in preventing all such outcomes, but there is evidence that perinatal mortality falls when women with raised blood pressure are given additional care (mainly an early elective delivery).
Congenital hypothyroidism
Authors: Hollowell Joseph G. , Therrell Bradford L. , Hannon W. Harry
Published: September 2009

This chapter describes screening and diagnosis for congenital hypothyroidism (CH). CH is a well-established cause of mental retardation which can be prevented by screening and treatment with thyroxine.
Continuous electronic fetal monitoring during labour
Authors: Leck Ian , Thacker Stephen B.
Published: September 2009

This chapter describes electronic fetal monitoring (EFM) during labour. EFM during labour involves recording the fetal heart rate by means of an electrode on the fetal scalp or an ultrasound probe on the mother's abdomen. The aim is to identify fetal hypoxia at an early enough stage in labour to carry out a Caesarean or instrumental delivery before the hypoxia can lead to perinatal death or lasting neuropsychiatric disability.
The objectives of preventive medicine
Authors: Rose Geoffrey
Published: September 2009

This chapter examines the scope and reasons for preventive medicine. It argues that the knowledge that we already possess is sufficient, if put into practice, to achieve great health gains for all and to reduce our scandalous international and national inequalities in health. Factors that impede its translation into action include widespread ignorance and lack of understanding of the issues and possibilities, and the deliberate opposition of powerful vested interests.
Individuals and populations
Authors: Rose Geoffrey
Published: September 2009

This chapter begins with a discussion of individual variations in health, identifying the genetic and social determinants of diversity. It then considers variation between populations and the importance of society in public health.
In search of health
Authors: Rose Geoffrey
Published: September 2009

This chapter begins with a discussion of how populations change. It then explores the scientific justification for change, social engineering versus individual freedom, war as the biggest largest threat to public health, social and economic deprivation, and the responsibility for health.
What Is a Cause?
Authors: Susser Ezra , Schwartz Sharon , Morabia Alfredo , Bromet Evelyn J.
Published: September 2009

Risk factor designs are still the most fully developed methods for the investigation of causes. Although new approaches are emerging in the current era, these approaches retain the risk factor paradigm as the basis for epidemiologic investigation in some very important contexts. This chapter discusses the underlying principles that have guided the era of risk factor epidemiology.
Choosing Controls
Authors: Susser Ezra , Schwartz Sharon , Morabia Alfredo , Bromet Evelyn J.
Published: September 2009

This chapter sharpens the focus to a central pitfall of case-control studies in psychiatric research: selecting valid controls. It revisits the logic of control selection and the guideline of balancing the odds. It proposes that this guideline can be used to operationalize the selection of controls in almost any context. It shows a practical application by taking up the problem of control selection in the context of comorbid disorders, a central dilemma for psychiatric case-control studies.
Comparability and the Case-Control Study
Authors: Susser Ezra , Schwartz Sharon , Morabia Alfredo , Bromet Evelyn J.
Published: September 2009

The validity of a case-control study depends upon sampling controls from the noncases in an unbiased way, that is, independent of exposure status. Although this safeguard will prevent introducing bias when the controls are selected, any bias already present in the underlying cohort will still be reflected in the case-control study. When the exposed and unexposed groups in the underlying cohort are not fully comparable, the resulting odds ratio will not reflect the causal effect of the exposure. It will be biased. In general, bias are handled in parallel fashion for cohort and case-control studies. But the logical connections between the problem and its resolution are more difficult to see in the context of the case-control design. This chapter explains these connections and their practical implications for the selection of controls. It discusses in turn the main sources of noncomparability: confounding, unequal attrition, and differential misclassification. It uses the nested case-control study to portray a logic that in large part also applies to the ordinary case-control study.
Choosing Cases in Biologic Psychiatry
Authors: Susser Ezra , Schwartz Sharon , Morabia Alfredo , Bromet Evelyn J.
Published: September 2009

The previous chapter proposed that biologic studies comparing cases with controls often correspond well to the case-control design. This chapter shows how this perspective can be useful for advancing biological psychiatry, focusing on the selection and the definition of cases in biologic studies. It argues that in biological studies comparing cases and controls, the principles developed by epidemiologists for the selection of cases in ordinary case-control studies can often be put in practice and substantially strengthen the design. However, these practices would impose unnecessary constraints on some biological studies in psychiatry, and their application must always be tailored to yield a net advantage.
Modern Family History Studies
Authors: Susser Ezra , Schwartz Sharon , Morabia Alfredo , Bromet Evelyn J.
Published: September 2009

Family history studies are now used for a much wider range of purposes than in the past. This chapter discusses their usefulness for refining phenotype definitions, targeting preventive interventions, characterizing genetic effects, and exploring gene-environment interaction. These are in addition to their original role in genetic research, which was to examine whether diseases aggregate in families. The chapter also elaborates on their relationship to the risk factor designs described in previous chapters.
Causal Explanation within a Risk Factor Framework
Authors: Susser Ezra , Schwartz Sharon , Morabia Alfredo , Bromet Evelyn J.
Published: September 2009

This chapter focuses on construct validity and external validity. Causal explanation enhances research endeavors both by increasing researchers' confidence in the causal effect of their risk factors and by delineating the extent to which the results of their study applies to other populations. Within the risk factor paradigm, construct validity and external validity form the basis of causal explanation.
Dependent and Dynamic Processes
Authors: Susser Ezra , Schwartz Sharon , Morabia Alfredo , Bromet Evelyn J.
Published: September 2009

Although critiques of current epidemiologic methods frequently invoke concepts derived from a complexity framework, applications of these approaches to epidemiologic problems are scarce. Broader application awaits both conceptual and methodological development. This chapter describes the broad outlines of this approach to explore and envision its potential for psychiatric epidemiologic research. It also draws attention to some nascent examples on the horizon.
Chapter Twelve The Upper South Debates Slavery and Colonization
Authors: Ford, Jr. Lacy K.
Published: September 2009

This chapter examines the upper South's political and policy response to the Turner insurrection. In the pensive months following Nat Turner's rebellion, Virginia formally reconsidered its official policy toward both slavery as an institution and the free black population within its borders. Pro-slavery planters from Virginia's Southside region advocated tough new measures to enhance white security, including tighter control over the free black population and greater vigilance over the institution of slavery itself. But with the state's tobacco plantations in relative decline and the comparative return on slave labor diminished, many Old Dominion leaders wanted to use the sense of urgency spawned by the Turner insurrection to take bolder steps toward addressing the problem of slavery.
Regression Models for Proportions
Authors: Holford Theodore R.
Published: September 2009

This chapter considers the problem of fitting binary response models to data in which there are multiple regressor variables that may be either discrete or continuous in nature. The linear logistic model, the most commonly used model for this type of response, provides estimates of parameters that are assumed to have linear effects on the log odds ratio, thus yielding values that can be interpreted as log odds ratios. The more flexible generalized linear models family that can readily be adapted for fitting many alternative forms for the relationship between exposure and disease outcome are considered: the log-linear hazard, the probit model, the linear odds model, and the linear power of the odds model. Exercises are provided at the end of the chapter.
Proportional Hazards Regression
Authors: Holford Theodore R.
Published: September 2009

This chapter relaxed the parametrically restrictive parameterization for time considered in Chapter 8, adopting instead a nonparametric set of models in which the exact form for the effect of time was left as an arbitrary function. This proportional hazards (or Cox) model provides a very rich framework for data analysis, enabling not only the consideration of factors that were measured at the beginning of follow-up but also to update the risk status over time. Exercises are provided at the end of the chapter.
Models of public health genetic policy development
Authors: Wilfond Benjamin S. , Thomson Elizabeth J.
Published: September 2009

This chapter begins with a history of policy development for genetic services in the United States. It includes a discussion of early genetic screening programs, a review of part policy statements about genetic screening, and a more detailed discussion of the consistent substantive criteria for genetic diagnostic services that have been recommended by various policy-making bodies. The chapter also presents two conceptual models for the development of public policy: the extemporaneous and the evidentiary models.
Newborn screening for cystic fibrosis: A paradigm for public health genetics policy development
Authors: Farrell Philip M. , Kosorok Michael R. , Rock Michael J. , Laxova Anita , Zeng Lan , Hoffman Gary , Laessig Ronald H. , Splaingard Mark L. ,   Wisconsin Cystic Fibrosis Neonatal Screening Study Group
Published: September 2009

This chapter illustrates how scientific studies can be used to facilitate public health policy decisions, particularly those concerned with newborn screening programs. More specifically, it reviews the autosomal recessive hereditary disorder cystic fibrosis (CF) and describes how it has become a model disease for policy development in the application of molecular genetics testing to newborn screening. The chapter includes a summary of the salient characteristics of CF, with particular emphasis on epidemiologic and diagnostic considerations; a brief overview of the immunoreactive trypsinogen (IRT) and IRT/DNA tests used to facilitate CF diagnosis in the newborn period through screening; and detailed information on the unique features and results of the Wisconsin CF Neonatal Screening Project, including how and why it was planned, organized, and conducted to access the benefits, risks, and costs of CF neonatal screening.
Using the internet to disseminate genetics information for public health
Authors: O'Leary Leslie A. , Collins Debra L.
Published: September 2009

This chapter focuses on the use of the Internet as a method of disseminating genetic information for public health. Topics covered include the history of the Internet, using the Internet to educate public health professionals in genetics, public health and the Internet, and genetic resources on the Internet.
Measurement and Analysis
Authors: Nelson Lorene M. , Tanner Caroline M. , Van Den Eeden Stephen K. , McGuire Valerie M.
Published: September 2009

This chapter focuses on measurement of exposures, risk factors, prognostic factors, in addition to statistical analysis methods for assessing the association of those factors with disease outcomes. Separate sections of the chapter are devoted to disease severity measures, general health and quality of life measures, and functional status measures, as well as methods of data collection (medical record abstraction, questionnaires, biological measures). The middle section of the chapter addresses issues regarding measurement error, including types of measurement error (random error, systematic error), misclassification (differential, nondifferential), and the effects of these errors on study validity. Methods for assessing and improving data reliability and validity are discussed. The last section of the chapter provides a concise but informative overview of statistical techniques for analyzing epidemiologic data.
Genetic Epidemiology of Neurologic Disease
Authors: Nelson Lorene M. , Tanner Caroline M. , Van Den Eeden Stephen K. , McGuire Valerie M.
Published: September 2009

This chapter begins with a discussion of Mendelian versus complex (non-Mendelian) neurological disorders, followed by an overview of the structure of DNA and the molecular basis of disease. It considers the methods of genetic epidemiology, differentiating family-based studies from population-based studies of unaffected individuals. The options for genetic epidemiology study designs are presented, with a discussion of strengths and limitations of each approach. Recent technological developments are discussed, as are the important ethical and social implications of genetic epidemiologic research in the study of neurological disorders.
Evidence-Based Medicine in Neurology
Authors: Nelson Lorene M. , Tanner Caroline M. , Van Den Eeden Stephen K. , McGuire Valerie M.
Published: September 2009

This chapter describes the principals and practice of evidence-based medicine (EBM), its limitations, and future directions for EBM. The goal of EBM is to provide high quality information in “real time” for neurologists to use in practice. Evidence-based medicine provides a set of tools to formulate a clinically important question about a particular patient and to efficiently access and critically evaluate relevant information. Neuroepidemiologic studies provide the groundwork for evidence-based medicine by supplying research about patient risk, prognosis, and harm.
The Examination of Neighborhood Effects on Health: Conceptual and Methodological Issues Related to the Presence of Multiple Levels of Organization
Authors: Diez Roux Ana V.
Published: September 2009

The investigation of neighborhood effects on health raises a series of conceptual and methodological issues related to the presence of observations at a lower level (e.g., individuals) nested within observations at a higher level (e.g., neighborhoods). Many of these issues are generalizable to a broad set of common situations in epidemiology involving nested data structures. The presence of multiple levels of organization (or nested sources of variability) requires the development of theories about how factors defined at different levels are related to health outcomes, and identifying the most appropriate research design for the question being investigated based on the level about which inferences are to be made and the level (or levels) at which the constructs relevant to the outcome are defined and measured. This chapter reviews the use of group-level variables in epidemiology; summarizes the characteristics of ecological studies, studies of individuals, and multilevel studies; and discusses some of the conceptual and methodological challenges that multilevel analysis faces, using the example of the investigation of neighborhood effects on health.
Multilevel Methods for Public Health Research
Authors: Subramanian S. V. , Jones Kelvyn , Duncan Craig
Published: September 2009

This chapter begins by outlining the conceptual motivation behind multilevel analyses and by identifying a core set of research questions that this approach addresses. It then introduces the idea of multilevel structures and discusses simple and complex multilevel models. It emphasizes that the key strength of multilevel models lies in modeling heterogeneity at different levels and shows how multilevel models can be extended to additional contextual levels (e.g., neighborhoods nested within regions). The estimation procedures underlying such models are discussed, showing how a multilevel framework can provide a general, unified approach to data analysis and how this can be achieved by extensions to the basic hierarchical structure of individuals nested within contexts. The chapter concludes with a discussion of issues that researchers should be aware of when applying multilevel methods.
Neighborhood-Level Context and Health: Lessons from Sociology
Authors: Sampson Robert J.
Published: September 2009

A new generation of neighborhood-level research has emerged in recent years to address the question of why so many health-related outcomes are concentrated ecologically. This chapter highlights the implications of such research for our knowledge about the community-level context of public health and safety. Drawing on recent lessons from sociological research, it identifies what it is about neighborhoods—above and beyond the status and attributes of the individuals who live there—that might lead to various health outcomes.
Area-Based Deprivation Measures: a U.K. Perspective
Authors: Gordon David
Published: September 2009

This chapter describes how the practice of measuring poverty at small area level in Britain differs significantly from that in the United States. In Britain deprivation indexes tend to be used, whereas in the United States low-income thresholds are preferred. The key question for health researchers is which is the most significant for studies of ill health and mortality. Studies in the United States have demonstrated that a clear and continuous gradient exists between mortality and income at ZIP code level. Studies in the United Kingdom, however, have also shown high levels of association between deprivation indexes and morbidity and mortality at various geographical levels.
Putting Asthma into Context: Community Influences on Risk, Behavior, and Intervention
Authors: Wright Rosalind J. , Fisher Edwin B.
Published: September 2009

This chapter examines the contextual factors related to the occurrence and risk of asthma, health behaviors, access to health care, and the design of effective interventions to reduce the burden of asthma. The latter is exemplified through the discussion of a specific community-based approach to asthma management: the Neighborhood Asthma Coalition.
Neighborhoods, Health Research, and Its Relevance to Public Policy
Authors: Heymann Jody , Fischer Aron
Published: September 2009

This chapter begins with a discussion of whether research on the health effects of neighborhoods will have an impact on public policy. It then discusses the barriers that research can help break down, past efforts to improve neighborhoods, challenges to conducting research, and addressing challenges to solution-oriented research.
The Task Is a Political One: The Promotion of Fluoridation
Authors: Reilly Gretchen Ann
Published: September 2009

In the first fifty years of efforts to fluoridate community water supplies in the United States, profluoridationists in many cities found their efforts thwarted by a vocal opposition able to convince local elected officials and voters to reject fluoridation. The antifluoridation movement was a coalition of various groups and individuals whose objections to fluoridation ranged widely. Some questioned the scientific evidence supporting fluoridation, but often their arguments extended beyond the realm of scientific debate to include sweeping philosophical and social concerns. Initially, profluoridationists focused on promoting fluoridation in much the same way that as they would other standard public health campaigns. In the face of continuing failures, however, their tactics evolved over time to include more directly political approaches.
Drivers, Wheels, and Roads: Motor Vehicle Safety in the Twentieth Century
Authors: Dellinger Ann M. , Sleet David A. , Jones Bruce H.
Published: September 2009

The public health problem of motor-vehicle-related death and injury emerged in the 20th century with the advent of new technology-the automobile. In the past 100 years, more than 2.8 million persons have died and nearly 100 million persons have been injured on U.S. roads and highways. Despite these statistics, substantial gains in driver behavior, vehicle safety, and road design improved the safety of motor-vehicle travel despite increases in motorization, shifting demographics, and changing social patterns. This chapter defines the modern public health problem of motor-vehicle travel. It highlights the leadership of William Haddon in revolutionizing the approach to the prevention of motor-vehicle injuries, the role of community organizations such as Mothers Against Drunk Driving in changing social norms, and outlines governmental and private industry efforts to reduce the incidence of death and injury attributable to motor-vehicles. The chapter looks forward to the challenges of transportation safety in the 21st century.
Heart Disease and Stroke Mortality in the Twentieth Century
Authors: Greenlund Kurt J. , Giles Wayne H. , Keenan Nora L. , Malarcher Ann Marie , Zheng Zhi Jie , Casper Michele L. , Croft Janet B.
Published: September 2009

Heart disease has been the leading cause of death in the United States since 1921, and stroke has been the third leading cause since 1938. Heart disease and stroke account for most cardiovascular disease (CVD) deaths in the United States. Although heart disease and stroke remain leading causes of death, age-adjusted death rates from all CVD have declined by 55% since 1950. This decline reflects an increased understanding of the causes of CVD, identification of preventable risk factors, improvements in treatment of heart disease and stroke and their antecedents such as hypertension, and implementation of intervention and prevention programs. This chapter summarizes the trends in heart disease and stroke in the 20th century, advances in the understanding of risk factors for these diseases, and development of prevention and intervention programs to reduce the risks of developing and dying from heart disease and stroke.
A Framework for Investigating Change over Time
Authors: Singer Judith D. , Willett John B.
Published: September 2009

This chapter describes why longitudinal data are necessary for studying change. Section 1.1 introduces three longitudinal studies of change. Section 1.2 distinguishes between the two types of issues these examples address: within-individual change, how does each person change over time? Interindividual differences in change, what predicts differences among people in their changes? This distinction provides an appealing heuristic for framing research questions and underpins the statistical models we ultimately present. Section 1.3 identifies three requisite methodological features of any study of change: the availability of multiple waves of data; a substantively meaningful metric for time; and an outcome that changes systematically.
Examining the Multilevel Model’s Error Covariance Structure
Authors: Singer Judith D. , Willett John B.
Published: September 2009

The previous chapters emphasized the fixed effects in the multilevel model for change. This chapter, in contrast, focuses on the model's random effects as embodied in its error covariance structure. Section 7.1 begins by reviewing the “standard” multilevel model for change, expressed in composite form. Section 7.2 examines this model's random effects, demonstrating that the composite error term is indeed both heteroscedastic and autocorrelated, as preferred for longitudinal data. Section 7.3 compares several alternative error covariance structures and provide strategies for choosing among them.
Modeling Change Using Covariance Structure Analysis
Authors: Singer Judith D. , Willett John B.
Published: September 2009

This chapter describes how to conceptualize, postulate, fit, and interpret a latent growth model. Section 8.1 begins by reviewing the general covariance structure model. Section 8.2 maps the multilevel model for change onto the general covariance structure model. Section 8.3 illustrates an invaluable extension of this approach that allows you to investigate whether change in one construct is related to change in another. Section 8.4 concludes by listing additional extensions of the basic approach briefly.