bluuebunny/crossref_metadata_2025 huggingface dataset:
Religion and Value Systems
Authors: Roccas Sonia
Published: November 2005

Uncovering the complex relationships between religiosity and values may provide a better understanding of what it means to be religious or nonreligious. This article reviews research on values and religiosity across cultural and religious groups. Although religious groups differ in the importance they attribute to different values, the pattern of correlations between religiosity and values is strikingly consistent across monotheistic religions: Persons more committed to religion attribute relatively high importance to values expressing motivation to avoid uncertainty and change and relatively low importance to values expressing motivations to follow one's hedonistic desires, or to be independent in thought and action.
Religion and World Change: Violence and Terrorism versus Peace
Authors: Silberman Israela , Higgins E. Tory , Dweck Carol S.
Published: November 2005

Our article portrays religion as a double‐edged sword that can both encourage and discourage world change, and can facilitate both violent and peaceful activism. The article demonstrates how the meaning system approach to religion can shed light on the complicated relationship between religion and world change by illuminating the meaning of world change and the means to achieve it, inherent differences across religious groups, the complexity and malleability of religious meaning systems, and processes that can facilitate either the status quo or violent and peaceful activism. The article discusses context and personality variables that may determine whether religion supports world change and either violent or peaceful activism. It recommends intensive collaboration between researchers, policy–makers, and religious leaders in the contexts of national and international conflicts and religious terrorism.
Psychometric and Rationalization Accounts of the Religion‐Forgiveness Discrepancy
Authors: Tsang Jo‐Ann , McCullough Michael E. , Hoyt William T.
Published: November 2005

World events and psychological research often fail to support a relationship between religion and forgiveness. We suggest that the gap between general religious support of forgiveness and actual forgiveness by religious individuals (the religion‐forgiveness discrepancy) described by McCullough and Worthington (1999) may be partly due to methodological shortcomings. We present three studies with 452 undergraduate participants to illustrate how psychometric weaknesses can obscure the relationship between religiousness and transgression‐specific forgiveness. We also propose a rationalization explanation that describes how religion might justify unforgiveness. We present a pilot study of 38 undergraduate participants that demonstrates correlations between retributive and compassionate religious beliefs, and transgression‐specific forgiveness. We discuss future research directions addressing the religion‐forgiveness discrepancy on psychometric and theoretical levels.
The Three Monotheistic World Religions and International Human Rights
Authors: Martin J. Paul
Published: November 2005

Judaism, Christianity, and Islam, and the human rights movement lay claim to much of the same moral territory, notably concepts of human dignity, equality, and social justice. In practice there are many tensions. This article argues that common standards are necessary to govern relationships among religions and that international human rights standards best play that role. To achieve greater consensus and mutual understanding, the religious and human rights communities must examine how their meaning systems can and have changed over time, and differ across regions. Recognition of these variations and empirical evidence that religiosity is not necessarily inherently linked to prejudice can enable both the religious and human rights meaning systems to evolve toward greater consensus on common social norms.
Religion as a Meaning System: Policy Implications for the New Millennium
Authors: Maton Kenneth I. , Dodgen Daniel , Sto. Domingo Mariano R. , Larson David B.
Published: November 2005

The development of social policy related to religion has received increasing focus in recent years, yet psychology continues to play a relatively minor role in this important domain. In the current article, religion's positive and negative influences as a meaning system on individual, community, and societal well‐being are delineated. The challenges facing psychology in contributing to public policy development in the religious arena are examined, challenges that stem from profound differences in the meaning systems of religion, government, and psychology. These challenges notwithstanding, a number of different pathways in the domains of applied research, community practice, and policy development are delineated through which psychology can help to maximize positive, and minimize negative, outcomes in the religion and social policy arena.
The Economic Effects of Federal Participation in Terrorism Risk
Authors: Hubbard R. Glenn , Deal Bruce , Hess Peter
Published: November 2005

Abstract

The catastrophic terrorist attack of September 11, 2001 caused unprecedented insured losses. While the insurance industry covered these losses, it also took swift steps to limit its exposure to such risks in the future. In response to ensuing market dislocations, the Terrorism Risk Insurance Act (TRIA) was passed in 2002. The law temporarily requires primary insurers to offer terrorism coverage and creates a federal “backstop” to limit losses on such coverage. In anticipation of the program's scheduled expiration, and to inform debate on its possible extension, this article analyzes market developments in the wake of 9/11 and the passage of TRIA. We find that to date, TRIA has facilitated private sector participation in the market for terrorism insurance by lending structure to an otherwise ill‐defined risk. While alternative terrorism risk bearing mechanisms are evolving, none appear ready to replace federal involvement presently. We conclude that a continuation of TRIA for a period of time would enhance U.S. economic performance in the near term. Failing to extend TRIA in the near term would result in decreased economic performance absent another major terrorist attack and greater instability, job loss, and bankruptcy in the event of another attack.
Regulating Genetic Information in Insurance Markets
Authors: Hoy Michael , Ruse Michael
Published: November 2005

Abstract

The debate on whether insurance companies should be allowed to use results of genetic tests for underwriting purposes is both lively and increasingly relevant as both technology and lawmaking efforts are progressing rapidly. In this article we outline the primary economic and non‐economic arguments made in favor of and against allowing insurers to risk‐rate premiums on the basis of genetic test results. While economic analysis has much to offer in enlightening this debate and informing policy makers, we argue that such work must be cast within the overall perspective of the genetic testing debate. Moreover, despite substantial strides by economists in understanding the role of information in the way insurance markets operate, much work still needs to be done in order for economic analysis to be confidently applied to the looming social issues of the continuing genetic revolution.
The Evolution of the Role of Risk Communication in Effective Risk Management
Authors: Nielson Norma L. , Kleffner Anne E. , Lee Ryan B.
Published: November 2005

Abstract

Risk management has evolved significantly over the past decades causing dramatic changes in the communication channels required to effectively handle the ever‐changing risks a firm faces. The first generation of risk management dealt primarily with risks inside a company creating a need for internal risk communication. The second generation, which arose with the growth in third‐party liability claims, involved many more stakeholders external to the company and forced the risk management function to deal with communications to these external parties. The third generation, which began as an expansion of the external risks that firms are exposed to, involves the board and senior management in the risk communication function.
Functional response: rigorous estimation and sensitivity to genetic variation in prey
Authors: Tully Thomas , Cassey Phillip , Ferrière Régis
Published: November 2005

Holling's type II functional response is a cornerstone of community ecology and coevolutionary theory. The so‐called disc equation is the most widely used model of the type II response, yet thus far no robust experimental assessment has been achieved in any single system. Fundamental issues that remain to be assessed include whether the assumptions of the disc equation are fulfilled, whether the disc equation yields accurate estimates of predation‐related individual traits, and whether differences in disc equation parameters can capture genetic variation in prey behaviour. This paper provides a rigorous approach to all of these questions. The functional response of the predatory mitePergamasus crassipeson three genetically distinct clones of the springtailFolsomia candidawas measured at six levels of prey density in controlled conditions where prey number and arena size were concomitantly manipulated. A crucial assumption of Holling's disc equation was fulfilled by maintaining a constant prey density for the entire experimental period of predation. The timing of each attack and capture, as well as the duration of the handling time, were recorded by constant observation. We contrasted three different methods to calculate functional response curves: (1) indirect estimation of the disc equation's parameters from the number of prey killed by the end of each experimental run; (2) direct estimation of the parameters via a unique protocol of constant observation; and (3) independently deriving a function based on direct measurements of encounter rate and attack success. The basic assumptions of the disk equation were globally fulfilled. Estimations of the functional response's parameters (type II) were remarkably congruent across approach (1) and (2). A single genetic effect was detected – the relationship between the encounter rate and prey density differed significantly between clones – whereas a direct comparison of functional response across clones failed to reveal genetic variation.
Sex‐biased herbivory: a meta‐analysis of the effects of gender on plant‐herbivore interactions
Authors: Cornelissen Tatiana , Stiling Peter
Published: November 2005

We used sets of meta‐analyses to review the evidence of sex‐biased herbivory in dioecious plants as well as intersexual differences in plant characteristics that might affect herbivores. Thirtythree studies were reviewed to assess the effects of plant sex on herbivore abundance, survivorship and damage imposed to host plants, whereas 54 studies were reviewed for the effects of plant sex on plant morphological, physiological, and nutritional characteristics. The standardized mean difference between males and females was chosen as the measure to calculate effect sizes. Male plants exhibited significantly higher numbers of herbivores (d++=1.074) and significantly higher herbivory measured in terms of plant damage (d++=0.577) compared to female plants. Effects of plant sex on herbivore abundance were stronger for folivores and gallformers compared to the other guilds, whereas effects of plant sex on herbivore damage were stronger for flower predators compared to browsers and folivores. No difference in herbivore survivorship was observed between sexes. Male plants exhibited significantly more leaves (d++=0.202), larger leaves (d++=0.91), fewer flowers (d++=−0.89) and longer stems (d++=0.614) than female plants. Although male plants exhibited significantly lower concentrations of secondary compounds (d++=−0.209) and other defenses (d++=−0.53) than female plants, no difference in nutrient concentration, such as foliar nitrogen, was observed between sexes.
Community structure and positive interactions in constraining environments
Authors: Tirado Reyes , I. Pugnaire Francisco
Published: November 2005

Spatial patterns in plant communities are thought to be controlled by the interplay of species interactions and environmental constraints. To evaluate the role of plant–plant interactions in shaping these communities we quantified species co‐occurrence and interaction in seven environmentally distinct communities. These included four different semiarid habitats in southeast Spain, one alpine system in the Sierra Nevada range (Spain), and two sites in Venezuela, a secondary savanna near Caracas (Altos de Pipe), and a sclerophyllous shrubland in the Gran Sabana plateau. We expected that facilitation would be stronger at sites with more spatial associations. The four semiarid sites in Spain and the shrubland in Gran Sabana showed a high degree of positive species associations. Of the other two communities, one showed both positive and negative associations while negative ones predominated in Altos de Pipe. The direct experimental measure of neighbors’ effect showed that positive interactions among species prevailed in communities where positive species associations dominated. The appearance of benefactor species in patches increased species richness compared with the surrounding inter‐shrub spaces. Our results provide a link between spatial patterns and species interactions, where aggregation points to positive interactions and segregation to competitive or interference effects. Facilitation appears as a relevant process shaping communities under environmental constraints.
Temperature‐associated upper limits to body size in terrestrial poikilotherms
Authors: Makarieva Anastassia M. , Gorshkov Victor G. , Li Bai‐Lian
Published: November 2005

We show that the largest tropical species of terrestrial poikilotherms from 25 taxa exceed, in linear body size, the largest representatives of the same taxa from the temperate (e.g. Great Britain) and polar (e.g. Wrangel Island) zones by 3.2 and 5.7 times, respectively. Here we develop a theoretical approach which quantitatively explains the observed body size patterns and relates them to ambient temperature under the assumption that there exists a temperature‐independent critical minimum value of mass‐specific metabolic rate bmin, a fall below which is incompatible with successful biological performance. This value sets an upper limit to linear body size within a taxon. Mass‐specific metabolic rate decreases with increasing body size but, in poikilotherms, grows exponentially with ambient temperature. Such compensation of the size‐related drop in mass‐specific metabolic rate b by higher ambient temperature extends the permitted range of body sizes for which b≥bmin. As a result, the maximum linear body size grows approximately twofold per each ten degrees of increase in ambient temperature. We also discuss why this prediction does not apply to interspecific comparisons of aquatic poikilotherms, for which an opposite trend is to be expected. We quantify in theory the maximum body size patterns recently reported for benthic gammaridean amphipods.
Parasite establishment and host extinction in model communities
Authors: De Castro Francisco , M. Bolker Benjamin
Published: November 2005

Studies of host–parasite dynamics usually consider one, or at most two, host species, neglecting the possible effects of other species on the focal hosts and vice versa. To explore the interaction of community structure with host–parasite dynamics, we model the invasion of stable communities of varying size by a parasite. The communities are generated with random interaction coefficients and connectance 0.5. Each community is invaded by parasites with different values of virulence (disease‐induced host mortality rate), specificity and transmission rate. The result of each invasion is determined by numerically simulating the dynamics of the community. We classify the outcomes by whether the parasite successfully establishes in the focal host population(s), and, if so, by the proportion of host and non‐host species that go extinct as a result of the parasite's introduction. We discuss how the structure of the community and the interaction between hosts and other species affect several important processes of disease ecology: the density threshold for parasite invasion, extinction cascades caused by the parasite, and the frequency of extinctions of hosts and non‐hosts. In our simulated communities, non‐host species went extinct more frequently than hosts, suggesting the importance of the community context of disease. In some cases, the parasite's invasion induced regular population cycles in the previously stable community.
When can noise induce chaos and why does it matter: a critique
Authors: Ellner S. P. , Turchin P.
Published: November 2005

Noise‐induced chaos illustrates how small amounts of exogenous noise can have disproportionate qualitative impacts on the long term dynamics of a nonlinear system. This property is particularly clear in chaotic systems but is also important for the majority of ecological systems which are nonchaotic, and has direct implications for analyzing ecological time series and testing models against field data. Dennis et al. point out that a definition of chaos which we advocated allows a noise‐dominated system to be classified as chaotic when its Lyapunov exponent λ is positive, which misses what is really going on. As a solution, they propose to eliminate the concept of noise‐induced chaos: chaos “should retain its strictly deterministic definition”, hence “ecological populations cannot be strictly chaotic”. Instead, they suggest that ecologists ask whether ecological systems are strongly influenced by “underlying skeletons with chaotic dynamics or whatever other dynamics”– the skeleton being the hypothetical system that would result if all external and internal noise sources were eliminated. We agree with Dennis et al. about the problem – noise‐dominated systems should not be called chaotic – but not the solution. Even when an estimated skeleton predicts a system's short term dynamics with extremely high accuracy, the skeleton's long term dynamics and attractor may be very different from those of the actual noisy system. Using theoretical models and empirical data on microtine rodent cycles and laboratory populations of Tribolium, we illustrate how data analyses focusing on attributes of the skeleton and its attractor – such as the “deterministic Lyapunov exponent”λ0 that Dennis et al. have used as their primary indicator of chaos – will frequently give misleading results. In contrast, quantitative measures of the actual noisy system, such as λ, provide useful information for characterizing observed dynamics and for testing proposed mechanistic explanations.
Testing the importance of patch scale on forest birds
Authors: Chan Kai M. A. , Ranganathan Jai
Published: November 2005

The relationship between population density and habitat area is of central importance to conservation biology, particularly for species dependent on declining habitat. A recent study by Lee et al. in Oikos in 2002 found that the densities of three forest interior bird species (ovenbirds, wood thrushes, and red‐eyed vireos) decline with increasing patch size, contradicting many other studies that demonstrate a positive correlation between area and density for these species. The authors’ argument is based on a misapplied criticism of the prevailing approach based on density‐and on an inappropriate statistical methodology, caused by incorrect specification of the null hypothesis after log–transformation. We use three different methods of testing area‐dependence: a corrected log–abundance log–area regression; a similar abundance–area regression; and the prevailing density‐area approach. For each species, all three methods agree broadly, suggesting the robustness of each approach. For ovenbirds and wood thrushes, we do not find that population density is negatively correlated to patch size. While our analyses of the red‐eyed vireo data find a negative correlation between the two factors, the strength of the correlation is far weaker than that of Lee et al. and may derive from landscape factors unconsidered in the original data. Nevertheless, we do not find positive density–area relationships for any of these forest‐interior species, further underscoring the site‐specificity of the underlying mechanisms of area‐ sensitivity.
Shape can influence the rate of colony fragmentation in ground nesting seabirds
Authors: Jackson Andrew L. , Bearhop Stuart , Thompson David R.
Published: November 2005

There have been catastrophic population declines at a number of rockhopper penguin Eudyptes chrysocome rookeries over the past 50 years or so. At Campbell Island, New Zealand, large contiguous rookeries have fragmented into much smaller subcolonies and although the underlying cause of the major part decline was possibly diet related, it seems likely that predation may be having an increasingly important impact. In an extension of selfish herd ideas, we hypothesised that since predation and colony contraction are edge related, the initial shape of the colony may play an important role in how quickly it might fragment and in turn how long it might persist. Intuition tells us that fragmentation is likely to occur on these smaller subcolonies and that their shape will likely affect their rate of fragmentation. We provide the first quantitative assessment of this qualitative theory of fragmentation risk as a function of colony shape for a range of hypothetical colonies.
Intraspecific and interspecific larval interaction in Drosophila assessed by integrated fitness measure
Authors: Takahashi Kazuo H. , Kimura Masahito T.
Published: November 2005

Intraspecific density effect was investigated for D. simulans, D. suzukii, D. auraria, D. rufa and D. immigrans, and interspecific density effect was examined for combinations of D. simulans, D. rufa and D. immigrans. Different numbers of their eggs were introduced to artificial substrates, and intra‐ and interspecific interaction were evaluated on the basis of per capita egg production of individuals (eggs) introduced. If individuals died before pupation, their per capita egg production was zero; if individuals survived to pupae, their per capita egg production was estimated from their size based on the relation between the pupal size and lifetime egg production. Per capita egg production thus estimated generally decreased with the increase of the density of conspecific larvae, although a slight increase was detected at high densities in some cases. When two species were introduced, per capita egg production of a species was reduced only when the larval density of co‐introduced species was very high, suggesting weak interspecific competition. Interspecific interaction was asymmetric; the effect of D. simulans on D. rufa and D. immigrans was often significantly negative, but the effect of D. rufa or D. immigrans on D. simulans was not significant.
The relationship between species richness of vertebrate mutualists and their food plants in tropical and subtropical communities differs among hemispheres
Authors: H. Fleming Theodore
Published: November 2005

Non‐random statistical patterns have long been of interest to community ecologists. Recent studies of communities of mutualists have revealed non‐random patterns in terms of connectance, degree of specialization, and nestedness. Currently unstudied, however, are the detailed statistical relationships between tropical vertebrate mutualists and their food plants in different parts of the world. Here, I review 87 studies that quantify the relationship between species richness of nectar‐ or fruit‐eating birds and bats and species richness of their food plants in New and Old World, mostly tropical, communities. This analysis revealed that in the New World, number of plant‐visiting birds and bats per community was significantly correlated with number of food plants and that the slopes of regression equations were the same for nectarivores and frugivores. The New World quantitative assembly rule states that it takes about three species of flowers or fruits to support one species of plant‐visiting bird or bat. This relationship does not appear to exist in Old World communities, in which species richness of nectar‐ or fruit‐eating birds or bats was independent of species richness of their food plants. These geographic differences likely reflect a greater degree of feeding specialization in plant‐visiting vertebrates in the New World than in the Old World. I hypothesize that hemispheric differences in the spatio‐temporal predictability (STP) of food resources ultimately determine levels of dietary specialization and structure in communities of New and Old World plant‐visiting vertebrates.
Can adaptation lead to extinction?
Authors: J. Rankin Daniel , López‐Sepulcre Andrés
Published: November 2005

Ever since J.B.S. Haldane proposed the idea, evolutionary biologists are aware that individual level adaptations do not necessarily lead to optimal population performance. A few deeply mathematical models, drawing from a diverse range of systems, even predict that individual selection can lead to the extinction of the whole population, a phenomenon which has become known as evolutionary suicide. Due to the complexity of both following adaptation and determining the exact cause of an extinction, evolutionary suicide has remained untested empirically. However, three recent empirical studies suggest that it may occur, and that suicide should be taken seriously as a potentially important evolutionary phenomenon. Here we ask whether or not evolutionary suicide can occur, briefly reviewing the theoretical and empirical evidence. We further highlight systems which may be used to test whether or not individual level selection can cause extinction.
Template‐independent ligation of single‐stranded DNA by T4 DNA ligase
Authors: Kuhn Heiko , Frank‐Kamenetskii Maxim D.
Published: November 2005

T4 DNA ligase is one of the workhorses of molecular biology and used in various biotechnological applications. Here we report that this ligase, unlike Escherichia coli DNA ligase, Taq DNA ligase and Ampligase, is able to join the ends of single‐stranded DNA in the absence of any duplex DNA structure at the ligation site. Such nontemplated ligation of DNA oligomers catalyzed by T4 DNA ligase occurs with a very low yield, as assessed by quantitative competitive PCR, between 10−6 and 10−4 at oligonucleotide concentrations in the range 0.1–10 nm, and thus is insignificant in many molecular biological applications of T4 DNA ligase. However, this side reaction may be of paramount importance for diagnostic detection methods that rely on template‐dependent or target‐dependent DNA probe ligation in combination with amplification techniques, such as PCR or rolling‐circle amplification, because it can lead to nonspecific background signals or false positives. Comparison of ligation yields obtained with substrates differing in their strandedness at the terminal segments involved in ligation shows that an acceptor duplex DNA segment bearing a 3′‐hydroxy end, but lacking a 5′‐phosphate end, is sufficient to play a role as a cofactor in blunt‐end ligation.
Haplotyping of the canine MHC without the need for DLA typing
Authors: McLure C. A. , Kesners P. W. , Lester S. , Male D. , Amadou C. , Dawkins J. R. , Stewart B. J. , Williamson J. F. , Dawkins R. L.
Published: November 2005

The genomic matching technique has proven useful in MHC haplotyping in humans. We have adopted a similar approach in Australian cattle dogs and report that genotyping can be achieved with a single assay.
Variability in TRBV haplotype frequency and composition in Caucasian, African American, Western African and Chinese populations
Authors: Brzezinski J. L. , Deka R. , Menon A. G. , Glass D. N. , Choi E.
Published: November 2005

The polymorphic T‐cell receptor Vβ (TRBV) genes encode much of the variable region of the T‐cell receptor β chain. Analysis of allele frequencies of three closely linked polymorphic TRBV genes, TRBV7‐3, TRBV9 and TRBV6‐4, was undertaken in several populations. The frequencies of these alleles are not significantly different in populations of Caucasians, African Americans and Western Africans. However, Chinese population is extremely homogenous at all three loci. The current study identifies the existence of haplotypic relationships between alleles of these genes in the Caucasian population. The ORF allele TRBV7‐3*A3 is found exclusively on chromosomes bearing TRBV9*A2 and TRBV6‐4*A2 in this cohort. In contrast, TRBV7‐3*A1 and the null allele TRBV7‐3*A2 are associated only with TRBV9*A1 and TRBV6‐4*A1. This pattern of linkage disequilibrium (LD) is altered in the African American and Western African populations. In these cohorts, there is a marked reduction in LD between alleles of TRBV7‐3 and TRBV9. This study is consistent with previous population genetic studies wherein African‐derived samples have a greater level of genetic diversity compared to Caucasians. These data also demonstrate that patterns of LD are not consistent across the entire TRBV locus.
Central Obesity, the Metabolic Syndrome, and Plasminogen Activator Inhibitor‐1 in Young Adults
Authors: Appel Susan J. , Harrell Joanne S. , Davenport Marsha L.
Published: November 2005

Purpose

To determine the association of central obesity with the components of the metabolic syndrome (i.e., hyperinsulinemia, hypertension, hypertriglyceridemia, low levels of high‐density lipoprotein cholesterol [HDL‐C]) and plasma levels of plasminogen activator inhibitor‐1 (PAI‐1) in young adults. We hypothesized that central obesity as determined by waist circumference would be predictive of components of the metabolic syndrome and of PAI‐1.

Data sources

Participants in this descriptive study consisted of 85 healthy young adults aged 19–22 years, 62% women who fasted for 12 h prior to data collection in the General Clinical Research Center at a major university hospital medical center in the southeastern United States.

Conclusions

The majority of the participants had one or more components of the metabolic syndrome (n= 43, 51%). Central obesity was present in 14.1% and was more common in women than men (χ2= 5.11; p= 0.021). Central obesity was significantly and positively correlated with elevated blood pressure (BP) and levels of insulin and PAI‐1 while being negatively correlated with HDL‐C. In multiple regression analyses, diastolic BP, insulin, and HDL‐C were predictors of waist circumference (R2= 0.615). In a separate multiple regression, PAI‐1 was predicted by waist circumference (R2= 0.331).

Implications for practice

Many otherwise healthy young adults have one or more components of the metabolic syndrome. Assessment and institution of preventative measures for obesity and the components of the metabolic syndrome should begin in childhood. Furthermore, determination of waist circumference especially in young women may aid the practitioner to identify those at risk for the metabolic syndrome earlier in their disease trajectory. Furthermore, insulin resistance is believed to occur initially in the trajectory of the metabolic syndrome, making it a principal contender for suitable interventions to reduce risk for both type 2 diabetes and cardiovascular disease (CVD). Homeostatic model assessment for insulin resistance was used to assess for insulin resistance among the euglycemic participants. Recording the presence of insulin resistance will aid the practitioner in determining if a low‐risk patient is in peril for development of type 2 diabetes and/or CVD. Early cardiovascular risk recognition is vital to clinical practice as it allows more time for the practitioner to counsel patients for the essential planning needed to make lifestyle changes.
The Paradox of Obesity in Patients with Heart Failure
Authors: Hall Jill A. , French Thomas K. , Rasmusson Kismet D. , Vesty Jill C. , Roberts Colleen A. , Rimmasch Holly L. , Kfoury A. G. , Renlund Dale G.
Published: November 2005

Purpose

Heart failure (HF) patients often have comorbid conditions that confound management and adversely affect prognosis. The purpose of this study was to determine whether the obesity paradox is also present in hospitalized HF patients in an integrated healthcare system.

Data sources

A cohort of 2707 patients with a primary diagnosis of HF was identified within an integrated, 20‐hospital healthcare system. Patients were identified by ICD‐9 codes or a left ventricular ejection fraction ≤40% dating back to 1995. Body mass index (BMI) was calculated using the first measured height and weight when hospitalized with HF. Survival rates were calculated using Kaplan Meier estimation. Hazard ratios for 3‐year mortality with 95% confidence intervals were assessed using Cox regression, controlling for age, gender, and severity of illness at time of diagnosis.

Conclusions

Three‐year survival rates paradoxically improved for patients with increasing BMI. Survival rates for the larger three BMI quartiles were significantly better than for the lowest quartile after adjusting for severity of illness, age, and gender.

Implications for practice

While obesity increases the risk of developing HF approximately twofold, reports involving stable outpatients suggest that obesity is associated with improved survival after the development of HF. This finding is paradoxical because obesity increases the risk and worsens the prognosis of other cardiovascular diseases.
BRCA1 Genetic Mutation and Its Link to Ovarian Cancer: Implications for Advanced Practice Nurses
Authors: Brunsvold Amy N. , Wung Shu‐Fen , Merkle Carrie J.
Published: November 2005

Purpose

The purpose of this paper is to review (a) the linkage between the BRCA1 gene and ovarian cancer and (b) BRCA1 testing and its related issues. This review is aimed for nurse practitioners (NPs), who may be in positions to identify those at risk for BRCA1‐associated ovarian cancer and to assist patients with related issues.

Data sources

Data sources include reviews and original research from scholarly journals and Internet sites.

Conclusions

Ovarian cancer is a deadly disease. Identification of those at risk because of BRCA1 mutation is possible through genetic testing. Testing for BRCA1 gene mutations has many implications whether results are positive or negative. Those with positive results will be faced with decisions regarding the best management strategies. Negative results do not completely eliminate ovarian cancer risk. Current management options for carriers of the BRCA1 mutation include taking no action, increasing surveillance for ovarian cancer, and chemoprevention with oral contraceptives or prophylactic oophorectomy for those who have completed childbearing. It is essential that NPs have knowledge underlying the issues and concerns of patients and their families at risk for BRCA1‐associated ovarian cancer.

Implications for practice

NPs are in a unique position to help identify BRCA1 mutation carriers and to assist them and their families with the complex issues involving genetic testing and management options. Understanding these issues will allow NPs to give appropriate care that may include making appropriate referrals to certified genetic counselors and having balanced discussions on treatment options. Such measurements may improve early diagnosis of ovarian cancer and increase survival from this disease.
Transformations of Nonlinear Systems to High-Order Generalized Chained Forms
Authors: Laiou Maria-Christina , Astolfi Alessandro
Published: November 2005

A variety of stabilization methods for nonlinear systems in chained form can be found in the literature. However, very few results exist in the area of systematically converting a general nonlinear system with two inputs to a chained form. This paper presents an algorithm for the conversion of a class of nonlinear systems with two inputs to a high-order chained, or generalized chained, form. The feedback transformation accomplishing this conversion is derived, provided certain conditions hold, by solving a system of partial differential equations. The proposed algorithm is illustrated by means of a physically motivated example, namely an under-actuated surface vessel.
On the Minimum Phase Property of Mass-Dashpot-Spring Sampled Systems
Authors: Chan Kuo-Chin , Lin Jong-Lick
Published: November 2005

In literature, it is shown by Åström et al. that a sampled system may become nonminimum phase for sufficiently fast sampling, even though the continuous-time system is minimum phase. However, it is verified in this paper that the sampled system of a modal damping mass-dashpot-spring structural dynamics with sufficient condition B=CTΓ is minimum phase independent of the sampling period. From a control point of view, this significant result is essential and beneficial to the digital controllers design for a large-scale structure. In addition, it also provides a criterion to locate the sensors and actuators of a structural system.
Impedance Control of Space Robots Using Passive Degrees of Freedom in Controller Domain
Authors: Pathak Pushpraj Mani , Mukherjee Amalendu , Dasgupta Anirvan
Published: November 2005

Impedance control is an efficient and stable method of providing trajectory and force control in robotic systems. The procedure by which the impedance of the manipulator is changed is a very important aspect in the design of impedance based control schemes. In this work, a scheme is presented in which the control of impedance at the interface of the end effector and the space structure is achieved by introduction of a passive degree of freedom (DOF) in the controller of the robotic system. The impedance is shown to depend upon a compensation gain for the dynamics of the passive DOF. To illustrate the methodology, an example of a two DOF planer space robot is considered.
Guaranteed Cost Observer-Based Control for a Class of Uncertain Time-Delay Systems
Authors: Lien Chang-Hua , Hou Yi-You
Published: November 2005

In this paper, the robust guaranteed cost observer-based controls for a class of uncertain time-delay systems are considered. The linear matrix inequality approach is used to design the feedback controls. Optimal guaranteed cost observer-based controls which minimize the upper bound of cost function are provided. A numerical example is given to illustrate our results.
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Robust Static Output Feedback Control Design via Mixed Genetic Algorithm and Linear Matrix Inequalities
Authors: Sun Chein-Chung , Chung Hung-Yuan , Chang Wen-Jer
Published: November 2005

This paper is concerned with the synthesis of a mixed H2∕H∞ robust static output feedback with a bounded control bandwidth for continuous-time uncertainty systems. To this end, genetic algorithms and a linear matrix inequality solver are employed to regulate the static output feedback gains and to examine the Lyapunov stability conditions, respectively. The fitness function of this paper, which is called a hierarchical fitness function structure (HFFS), is able to deal with the stability conditions and the performance constraints in turn. This HFFS not only saves computing time but can also identify the infeasible stability condition. Designers can use the proposed idea to deal with many complex output feedback control problems. It also limits elaborate mathematical derivations and extra constraints.
Modeling and Multivariable Control Design Methodologies for Hexapod-Based Satellite Vibration Isolation
Authors: Joshi Alok , Kim Won-jong
Published: November 2005

A mathematical model of a six-degree-of-freedom (6-DOF) hexapod system for vibration isolation was derived in the discrete-time domain on the basis of the experimental data obtained from a satellite. Using a Box–Jenkins model structure, the transfer functions between six piezoelectric actuator input voltages and six geophone sensor output voltages were identified empirically. The 6×6 transfer function matrix is symmetric, and its off-diagonal terms indicate the coupling among different input/output channels. Various multi-input multi-output (MIMO) control techniques such as Linear Quadratic Gaussian and H∞ were proposed for active vibration isolation in the broadband up to 100 Hz. The simulation results using these controllers obtain 13 and 8 dB vibration attenuation at 25 and 35 Hz, respectively.
Robust Decentralized Adaptive Control for Interconnected Systems With Time Delays
Authors: Hua Changchun , Guan Xinping , Shi Peng
Published: November 2005

The problem of robust stabilization for a class of time-varying nonlinear large-scale systems subject to multiple time-varying delays in the interconnections is considered. The interconnections satisfy the match condition, and are bounded by nonlinear functions that may contain a high-order polynomial with a time delay. Without the knowledge of these bounds, we present adaptive state feedback controllers that are continuous and independent of time delays. Based on the Lyapunov stability theorem, we prove that the controllers can render the closed loop systems uniformly ultimately bounded stable. We also apply the result to constructing adaptive feedback controllers to stabilize a class of interconnected systems whose nominal systems are linear. Finally, several examples are given to show the potential of the proposed techniques.
Natural Observer Design for Singularly Perturbed Vector Second-Order Systems
Authors: Demetriou Michael A. , Kazantzis Nikolaos
Published: November 2005

Our aim in the present research study is to develop a systematic natural observer design framework for vector second-order systems in the presence of time-scale multiplicity. Specifically, vector second-order mechanical systems are considered along with fast sensor dynamics, and the primary objective is to obtain accurate estimates of the unmeasurable slow system state variables that are generated by an appropriately designed model-based observer. Within a singular perturbation framework, the proposed observer is designed on the basis of the system dynamics that evolves on the slow manifold, and the dynamic behavior of the estimation error that induces is analyzed and mathematically characterized in the presence of the unmodeled fast sensor dynamics. It is shown, that the observation error generated by neglecting the (unmodeled) fast sensor dynamics is of order O(ε), where ε is the singular perturbation parameter and a measure of the relative speed/time constant of the fast (sensor) and the slow component (vector second-order system) of the overall instrumented system dynamics. Finally, the performance of the proposed method and the convergence properties of the natural observer designed are evaluated in an illustrative example of a two-degree of freedom mechanical system.
Identification of the Twin Independent Variable Cam Timing Engines for AFR Control
Authors: Genç A. Umut , Glover Keith
Published: November 2005

A control-oriented air-fuel ratio path model is developed to represent a spark-ignited, port-fuel-injected, twin-independent variable cam timing engine. Following a recent publication [Genç et al., SAE 2002-01-2752 (2002)] showing that cam timing not only affects the cylinder air flow but also the transient cylinder fuel flow, this paper constructs a mean value model that describes both air and fuel dynamics. While steady-state engine tests have been performed in order to identify the air path dynamics, a combination of linear and nonlinear identification methods have been used in order to identify the fuel path model including the wall-wetting dynamics. The resulting parameter-varying model has been validated with independent experimental data and can be used in powertrain controller design and development.
Constrained Control Design for Magnetic Bearing Systems
Authors: Hu Tingshu , Lin Zongli , Jiang Wei , Allaire Paul E.
Published: November 2005

We study control problems in magnetic bearing systems that are subject to both input and state constraints. Apart from the usual restrictions on voltages and currents in the circuit systems, most magnetic bearing systems are subject to a severe state constraint: the motion of the rotor (the suspended object) is only allowed in an extremely small airgap, otherwise the collision of the rotor and the stator would cause severe damages. Traditional methods for avoiding a collision include increasing the airgap and increasing the currents, which would usually result in unnecessarily large capacity of power supply and power loss. In this paper we present a systematic approach for dealing with all the input and state constraints by using some recently developed tools for constrained control design. Issues on the stability region, robustness, disturbance rejections, and transient response are addressed. We hope that by dealing with the constraints properly, safety operation can be ensured with relatively small currents and power consumption. Experiments on the balance beam test rig in our laboratory show that the design techniques are effective.
Dynamic Responses of an Atomic Force Microscope Interacting with Samples
Authors: Ha Jih-Lian , Fung Rong-Fong , Chen Yi-Chan
Published: November 2005

The objective of this paper is to formulate the equations of motion and to analyze the vibrations of an atomic force microscope (AFM), which contains a piezoelectric rod coupling with a cantilever beam, and the tip mass interacting with samples. The governing equations of the AFM system are formulated completely by Hamilton’s principle. The piezoelectric rod is treated as an actuator to excite the cantilever beam via an external voltage. The repulsive forces between the tip and samples are modeled by the Hertzian, the Derjaguin-Müller-Toporov, and Johnson-Kendall-Roberts models in the contact region. Finally, numerical results are provided to illustrate the coupling effects between the piezoelectric actuator and the cantilever beam and the interaction effects between the tip and samples on the dynamic responses.
Vibrio cholerae
ToxT Independently Activates the Divergently Transcribed
aldA
and
tagA
Genes
Authors: Withey Jeffrey H. , DiRita Victor J.
Published: November 2005

The
Vibrio cholerae
ToxT regulon includes the genes encoding cholera toxin (CT) and the toxin-coregulated pilus (TCP), which are the major virulence factors required for causing cholera disease and colonizing the upper small intestine of the host, respectively. The genes encoding CT,
ctxAB
, and the genes encoding the components of the TCP,
tcpA
to
tcpJ
, are organized within operons, upstream of which are DNA binding sites for the transcriptional activator ToxT. ToxT is a member of the large AraC/XylS family of transcriptional regulators and also activates transcription of five other genes whose roles in
V. cholerae
pathogenesis, if any, are poorly understood.
acfA
and
acfD
are divergently transcribed genes required for efficient colonization of the intestine. Transcriptional activation of
acfA
and
acfD
requires a pair of central ToxT binding sites in an inverted-repeat configuration for ToxT-directed transcription of both genes.
tcpI
has an unknown role in pathogenesis.
aldA
and
tagA
are divergently transcribed genes that also have unknown roles in pathogenesis. In this study, we map the
aldA
and
tagA
promoters and identify the ToxT binding sites upstream of each gene. Our results suggest that two ToxT binding sites in an inverted-repeat configuration are required for ToxT-directed transcription of
tagA
and that a single ToxT binding site is required for ToxT-directed transcription of
aldA
. Furthermore, to direct transcription of
tagA
and
aldA
, ToxT uses independent binding regions upstream of each gene, in contrast to what we previously found for the divergently transcribed
acfA
and
acfD
genes, which share ToxT binding sites between the two genes.