bluuebunny/crossref_metadata_2025 huggingface dataset:
Theories of Markets and Theories of Society
Authors: Fourcade Marion
Published: April 2007

Starting from the objectively dominant position of the sociology of markets in economic sociology, this article suggests that markets have served as a privileged terrain for the development and application of general theoretical arguments about the shape of the social order. I offer a critical overview of the sociology of markets as it relates to our concepts of society, focusing on four main representations of what is sociologically important about markets: the social networks that sustain them, the systems of social positions that organize them, the institutionalization processes that stabilize them, and the performative techniques that bring them into existence. I then speculate about the possible future directions that such theorizing might take, calling in particular for a stronger contribution of the sociology of markets to the analysis of societies as moral orders.
Pasts and Futures of Economic Sociology
Authors: Zelizer Viviana A.
Published: April 2007

Over the past few decades, economic sociology has moved from tight symbiosis with mainstream economics toward the construction of alternative explanations for economic activities. That move has allied economic sociologists increasingly with both innovative work inside economics and new analytic enterprises outside. Cumulatively, these developments have created a much more social interpretation of money and markets.
Economic Sociology and the Social Problem of Energy Inefficiency
Authors: Biggart Nicole Woolsey , Lutzenhiser Loren
Published: April 2007

The rebirth of economic sociology in the last decades of the 20th century was largely about intellectual identity formation and developing theoretical foundations. The authors argue that economic sociology is poised to make a contribution to the understanding and solution of social problems. They use the example of energy inefficiency in the commercial buildings industry to suggest that economic sociology offers useful alternatives to current economic-based policy analyses.
A Meta-Analysis of Testing Mode Effects in Grade K-12 Mathematics Tests
Authors: Shudong Wang  , Hong Jiao  , Young Michael J. , Brooks Thomas , Olson John
Published: April 2007

This study conducted a meta-analysis of computer-based and paper-and-pencil administration mode effects on K-12 student mathematics tests. Both initial and final results based on fixed- and random-effects models are presented. The results based on the final selected studies with homogeneous effect sizes show that the administration mode had no statistically significant effect on K-12 student mathematics tests. Only the moderator variable of computer delivery algorithm contributed to predicting the effect size. The differences in scores between test modes were larger for linear tests than for adaptive tests. However, such variables as study design, grade level, sample size, type of test, computer delivery method, and computer practice did not lead to differences in student mathematics scores between computer-based and paper-and-pencil modes.
Consistency of Fear of Failure Score Meanings Among 8- to 18-Year-Old Female Athletes
Authors: Conroy David E. , Coatsworth J. Douglas , Kaye Miranda P.
Published: April 2007

Fear of failure (FF) energizes individuals to avoid failure because of the learned aversive consequences of failing (e.g., shame). Although FF is socialized in childhood, little is known about the meaning of scores from FF measures used with children and adolescents. This study addresses that void by establishing a preliminary nomological network for FF scores from a younger population than has previously been studied. Girls ( N = 97) aged 8 to 18 years ( M = 13.2) completed measures of FF, situational motivation, sport anxiety, self-esteem, physical self-concept, and social competence during the first week of a recreational softball league. Results indicated that FF scores were positively associated with age. General FF also was associated with higher levels of sport anxiety and lower levels of self-determined motivation, self-esteem, skill-related physical self-concept, and social competence. Age did not moderate any of these relationships; thus, aspects of the nomological network for interpreting FF scores from the Performance Failure Appraisal Inventory can be extended to children as young as age 8.
Confidence Intervals for an Effect Size Measure in Multiple Linear Regression
Authors: Algina James , Keselman H. J. , Penfield Randall D.
Published: April 2007

The increase in the squared multiple correlation coefficient (ΔR 2) associated with a variable in a regression equation is a commonly used measure of importance in regression analysis. The coverage probability that an asymptotic and percentile bootstrap confidence interval includes Δρ2 was investigated. As expected, coverage probability for the asymptotic confidence interval was often inadequate (outside the interval .925 to .975 for a 95% confidence interval), even when sample size was quite large (i.e., 200). However, adequate coverage probability for the confidence interval based on a bootstrap interval could typically be obtained with a sample size of 200 or less, and moreover, this accuracy was obtained with relatively small sample sizes (100 or less) with six or fewer predictors.
Mixed Rasch Modeling of the Self-Rating Depression Scale
Authors: Hong Sehee , Min Sae-Young
Published: April 2007

In this study, mixed Rasch modeling was used on the Self-Rating Depression Scale (SDS), a widely used measure of depression, among a non-Western sample of 618 Korean college students. The results revealed three latent classes and confirmed the unidimensionality of the SDS. In addition, there was a significant effect for gender in terms of class membership. The implications for diagnosis and treatment for normal populations are discussed as well as the differences in depression profiles of those in Western and non-Western samples.
A Construct-Related Validity Study on a Korean Version of the Perceptual Learning Styles Preference Questionnaire
Authors: Isemonger Ian , Sheppard Chris
Published: April 2007

This study examined the factor structure of a Korean version of the Perceptual Learning Styles Preference Questionnaire. The instrument was developed to measure the learning-style preferences of students of English as a second language and English as a foreign language and has gained wide currency as a classroom diagnostic tool and survey instrument for research on second-language acquisition. Reliability estimates (Cronbach's α) for scores on the six scales hypothesized by Reid were generally not good and corroborated results in the limited number of previous studies. A confirmatory factor analysis led to the rejection of the hypothesized model, and an exploratory factor analysis suggested a three-factor model as more appropriate. It is argued that the results of this study indicate that the instrument is flawed and that the results of previous research based on it are questionable. It is also argued that the continued use of the instrument within the research trajectory of second-language acquisition be suspended until the instrument has been revised.
Downsizing Survivors' Communication Networks and Reactions: A Longitudinal Examination of Information Flow and Turnover Intentions
Authors: Susskind Alex M.
Published: April 2007

The pre- and postdownsizing information flow and postdownsizing turnover intentions of downsizing survivors were examined in the corporate office of an international hotel company. Using a combination of network analysis and path analysis, the relationship between changes in downsizing survivors' betweenness centrality and perceptions of information adequacy relative to reported turnover intentions were examined across two postdownsizing time periods. Results of the path analyses provided general support for the model as hypothesized, indicating in postdownsizing periods that changes to network members' network centrality positively influenced changes in their perceptions of information adequacy, which then negatively influenced their turnover intentions. The article concludes with a discussion of the support for the hypotheses and the study's limitations and pragmatic implications.
Parental Mediation of Children's Emotional Responses to a Violent News Event
Authors: Buijzen Moniek , Walma van der Molen Juliette H. , Sondij Patricia
Published: April 2007

In a survey among 451 elementary school children (8 to 12 years old), the authors investigate (a) to what extent children's exposure to news coverage of a violent news event is related to their feelings of fear, worry, anger, and sadness and (b) to what extent active (i.e., helping children understand what they see on the news) and restrictive (i.e., keeping children from watching the news) parental mediation strategies moderate the impact of the news. Findings show that children's news exposure is significantly related to their emotional responses. Active mediation successfully reduces the relations between news exposure and fear, worry, and anger but only among the younger children in the sample. Restrictive mediation has no or even an opposite effect. However, findings also suggest that the effectiveness of the mediation may depend on the child's level of news exposure.
Family Role in the Reintegration Process of Recovering Drug Addicts
Authors: Gideon Lior
Published: April 2007

In an outcome evaluation of recovering addicts who participated in a prison-based therapeutic community, 39 clients, a nonrandomized subsample, are interviewed about their rehabilitation and reintegration experience. This study focuses on the family as the main source of support and as an agent of change for the recovering drug addict. Although many studies show marriage and family to be positively related to successful reintegration and rehabilitation, clients in this study report families as having a negative effect on the rehabilitation and reintegration process. This is especially true among those who reunite with their spouse. The findings are discussed in regard to role expectations and support mechanisms, and suggestions are made for further research.
Achieving Justice for Children
Authors: Borowski Allan , Ajzenstadt Mimi
Published: April 2007

In 1999, public defender (PD) representation of defendants appearing before Israel's juvenile courts began to be phased in. This article reports some of the major findings of a study that examined the impacts of the introduction of PDs. Analysis of interviews with 14 PDs yielded four major themes concerning the impact of the “arrival” of PDs, nature of the court, PDs' role, and PDs' interactions with other court actors. Analysis of interviews with eight prosecutors yielded seven themes concerning the need for PDs, PD as state agent, PDs' role, harms of legalization, disruption of the court, compromising the therapeutic value of the court hearing, and changes in court process. More generally, both PDs and prosecutors placed uncritical store in the value of rehabilitation alternatives. Indeed, the welfare model continues to shape their roles. The findings can largely be explained in terms of Eisenstein and Jacob's courtroom workgroup model.
Intensive Case Management as a Jail Diversion Program for People With a Serious Mental Illness
Authors: Loveland David , Boyle Michael
Published: April 2007

This article reviews the research on intensive case management (ICM) programs as a jail diversion intervention for people with a serious mental illness (SMI). The review includes two types of ICM programs: (a) general ICM programs that included an assessment of arrests and incarceration rates for people with an SMI and (b) ICM programs specifically implemented as a component of a jail diversion intervention for people with an SMI. Results indicate that general ICM programs (19) rarely led to reductions in jail or arrest rates over time, and these rates were similar to those found in standard mental health services. General ICM programs that included an integrated addiction treatment component (8) had mixed results but a trend toward reductions in rates of arrests and incarceration over time for individuals with an SMI and a co-occurring substance use disorder. Results were mixed for jail diversion interventions with an ICM program, but most ICM programs (8) led to significant reductions in arrests and incarcerations over time. Specific elements of effective ICM jail diversion programs are discussed.
Well-Being and Family Support Among Elderly Rural Mexicans in the Context of Migration to the United States
Authors: Gonzalez Vazquez Tonatiuh , Bonilla Fernandez Pastor , Jauregui Ortiz Berenice , Yamanis Thespina J. , Salgado de Snyder V. Nelly
Published: April 2007

Objective: To explore perceptions of well-being, family support, and economic resources in relation to level of contact with migration to the U.S. among a sample of elderly males from rural Mexico. Method: The snowballing technique was used to obtain a sample of 372 participants. Four groups were created according to the level of contact with migration among older adults and their children. Results: Greater level of contact with migration was associated with a higher likelihood that an older adult was literate, married or living with someone, self-employed, and retired or pensioned. In addition, greater level of contact with migration to the U.S. was associated with a higher level of perceived well-being, family support, and economic security. Discussion: Elderly, rural Mexican men with a greater degree of contact with migration to the U.S. seem to have more security and well-being in their old age.
Bereavement Among African American and White Older Adults
Authors: Williams Beverly Rosa , Sawyer Baker Patricia , Allman Richard M. , Roseman Jeffrey M.
Published: April 2007

Purpose: The authors examined epidemiology and sociodemographic predictors of spousal, nonspousal family, and friendship bereavement among African American and White community-dwelling older adults using longitudinal data from 839 participants of the University of Alabama at Birmingham Study of Aging, a prospective cohort study of a random sample of Alabama Medicare beneficiaries. Method: Authors calculated cumulative incidences of each type of loss and used logistic regression to identify factors significantly and independently associated with loss. Results: Of participants, 71% reported at least one loss; 50% reported nonspousal family loss, and 37% reported friendship loss. For married participants, the cumulative incidence of spousal loss was 8.1%. Female sex and income < $12,000 were predictors of spousal loss. Female sex and education ≥ 12 years were predictors of friendship loss. Higher educated African American women were at greater risk of nonspousal family loss. Discussion: Future research should examine bereavement burden and identify health outcomes of multiple losses.
California Nursing Facility Quality and Union Environments
Authors: Swan James H. , Harrington Charlene
Published: April 2007

Objectives: Many studies have examined quality effects of nursing facility (NF) staffing, but few have examined effects of unionization. Concerned with possible effects of unionization on quality, we analyzed unionization and local market climate of unionization, predicting both complaints (reflecting either quality problems or better monitoring and advocacy) and the substantiation of serious complaints (indicating major quality problems). Method: Data were analyzed on California freestanding NFs in 1999 ( N= 1,155). OLS regression was employed to predict both quality complaints and serious violations, the latter both controlling and not controlling for numbers of complaints. Results: Unionized NFs showed more complaints than did nonunionized NFs. Nonunionized NFs had more serious violations, particularly when the proportion of other county facilities unionized was higher. Discussion: These findings suggest that unionization enhances problem reporting while, especially in stronger union environments, reducing the incidence of serious quality violations.
Predatory vs. Dialogic Ethics
Authors: Cannella Gaile S. , Lincoln Yvonna S.
Published: April 2007

The ethical conduct of research is addressed from two perspectives, as a regulatory enterprise that creates an illusion of ethical practice and as a philosophical concern for equity and the imposition of power within the conceptualization and practice of research itself. The authors discuss various contemporary positions that influence conceptualizations of ethical practices that include imperialist market imperatives for research that marginalize ethical concerns, positions held by peoples who have themselves been traditionally placed in the margins of societal power, academic positions and the selves of individual researchers, and locations created for the specific regulation of research. The final section of the paper introduces the articles in this special issue; these articles illustrate the complexity and cultural embeddedness of research regulation as well as the need for reflexive critical discourses that recognize the moral and ethical dimensions of everything but especially as related to the construction and practice of research.
Rethinking Ethics Review as Institutional Discourse
Authors: Halse Christine , Honey Anne
Published: April 2007

In this article, the authors trace the emergence of an institutional discourse of ethical research and interrogate its effects in constituting what ethical research is taken to be and how ethical researchers are configured. They illuminate the dissonance between this regime of truth and research practice and the implications for the injunction to respect others, illustrating their case with instances from their interview study with anorexic teenage girls. The authors propose that conceptualising the regulation of research ethics as an institutional discourse opens up the possibility for asserting counterdiscourses that place relational ethics at the center of moral decision making in research.
Canadian University Ethics Review
Authors: Tilley Susan , Gormley Louise
Published: April 2007

Drawing from educational research conducted in Canada and Mexico, university researchers explore how culture complicates both the ethics review process and the translation of ethical research principles into practice. University researchers in Canadian contexts seek approval from university Research Ethics Boards to conduct research, following policies outlined in the Tri-Council Policy Statement: Ethical Conduct for Research Involving Humans. In this article, the authors consider some cross-cultural ethical dilemmas in relation to educational research, which is often qualitative and interpretive in nature and conducted in schooling settings. Drawing from educational research, the authors conduct both in Canada and in an international context an exploration of how culture complicates both the ethics review process and the translation of ethical research principles into practice. As a result of their experiences, the authors focus specifically on issues related to consent, reciprocity, anonymity and confidentiality, and data representation.
Informed Consent, Deception, and Research Freedom in Qualitative Research
Authors: Marzano Marco
Published: April 2007

Does there exist only one, universally valid, research ethic? Are informed consent and ethical committees the best means to ensure the moral correctness of research? Again, what consequences ensue from the introduction of these instruments for the freedom of research and the quality of its results? This article addresses these issues by first recounting an ethnography conducted by its author in the oncology department of a large Italian hospital. To carry out his research the author initially had to conceal his identity and the purpose of his presence from the patients. Only later was this mode of conducting his fieldwork abandoned. The rest of the article compares this experience with very different ones reported by a number of American ethnographers. The article concludes by examining problems, such as the influence of the cultural context on the ethnographer's moral choices, or the value of informed consent and ethical committees, in the light of the empirical materials previously presented.
The Phantoms of Home Care: Home Care Nurses' Care Decisions for Medicare Home Health Alzheimer's Disease Patients
Authors: Cabin William D.
Published: April 2007

Early indications are that the Medicare home health prospective payment system (PPS) has controlled Medicare home health expenditures. However, studies indicate many unresolved questions about whether PPS improves patient quality of care and is cost-effective. The article reviews effective home-based palliative care interventions and presents the views of seven home health care nurses regarding the impact of Medicare requirements on their care decisions for one chronic disease population—Alzheimer's disease. The article asserts the current failure to simultaneously address the cost and quality-of-life issues of home health Alzheimer's patients is analogous to the end-of-life care situation Medicare confronted in the 1970s prior to the Medicare hospice demonstration program that preceded the Hospice Medicare Benefit. The article asserts that a similar demonstration is appropriate to determine how PPS might better meet patient quality-of-life needs and the government's need to reduce costs.
Outcomes in Rural and Urban Home Health Agencies
Authors: Sutton Janet P.
Published: April 2007

This study used Home Health Compare data to determine whether rural and urban home care agencies differ in terms of patient care outcomes. Small differences in the quality of care provided by home health agencies in urban and rural areas were found. Measured in terms of improvement in functional outcomes, differences were generally less than 2 percentage points, and rural agencies' performance was neither consistently better nor consistently worse than that of their urban counterparts. When measured as adverse events, rural and urban differences were not significant. Even though results were statistically significant, this does not imply that they were important or clinically meaningful; rather, results suggest that rural and urban agencies' performance on the set of outcomes measured in this study is relatively comparable. This is an encouraging result given concerns that access to skilled providers (e.g., occupational therapists) is limited in many rural communities. Additional research is needed to identify the factors driving performance in rural home health agencies.
Effect of heterogeneous deformation on precipitate distribution in Al–3·7Cu and Al–3·8Cu–1·8Mg alloys
Authors: Blaz L. , Piela K.
Published: April 2007

Cold rolling and hot rolling of solution treated Al–3·7Cu and Al–3·8Cu–1·8Mg alloys were performed to test the effect of inhomogeneous precipitation in shear bands during following aging of the material. The most effective inhomogeneous distribution of particles was observed for samples hot deformed and aged within the temperature range 473–573 K. It was noted that magnesium addition intensifies coarse shear bands development and following coarsening of particles within sheared area.
Compressive behaviour of open cell Al–Al2O3 composite foams fabricated by sintering and dissolution process
Authors: Yang Y. J. , Han F. S. , Yang D. K. , Zheng K.
Published: April 2007

The sintering and dissolution process (SDP) was used to produce the fine open cell Al–Al2O3 composite and pure Al foams with the relative density of 0·25–0·40 and the pore size of 112–400 μm. The composite foam exhibited much higher yield strength and Young's modulus than the pure Al foam, and thus had an elevated plateau stress. Moreover, the composite foam showed a unique dependence of the compression stress on the pore size, i.e. it increased with increasing pore size, which was quite different from that for the common metal foams.
Effect of predeformation on microstructure and mechanical properties of Al–Cu–Li–Zr alloy containing Sc
Authors: Liang W.-J. , Pan Q.-L. , He Y.-B. , Zhu Z.-M. , Liu Y.-F.
Published: April 2007

The effects of prior cold deformation on the microstructures and the room temperature mechanical properties of an Al–3·5Cu–1·5Li–0·22(Sc + Zr) alloy have been observed by using TEM and tensile test at room temperature. The results show that the alloy has the character of aging hardening, and the major phase of precipitation and strengthening is T1 phase. The result also show that prior cold deformation leads to more dispersive and uniform distribution of T1 precipitations. It accelerates aging response, causes earlier aging peak occurrence, and enhances strength greatly. However, the plasticity of the alloy is declined with prior cold deformation. In contrast, excessive prior cold deformation causes coarsening and heterogeneous distribution of T1 phase. It also reduces the strength of the alloy, therefore, influences the composite properties of the alloy. The favourable prior cold deformation is about 3·5% under the experimental condition.
Influence of thermomechanical processing on superplastic forming of Mg–Al alloys
Authors: Pérez-Prado M. T. , del Valle J. A. , Salort F. , Peñalba F. , Gómez X. , Ruano O. A.
Published: April 2007

The aim of this paper is to study the influence of the initial microstructure of several Mg–Al alloys on their superplastic formability and on their post-forming microstructure and mechanical properties. Various thermomechanical processing routes, such as annealing, conventional rolling, severe rolling and cross rolling, were used in order to fabricate AZ31 and AZ61 alloys with different grain sizes. These materials were then blow formed into a hat shaped die. It was found that the processing route has only a small effect in the formability of Mg–Al alloys or on the post-forming microstructures and properties due to rapid dynamic grain growth taking place at the forming temperatures. Nevertheless, good formability is achieved as a result of the simultaneous operation of grain boundary sliding and crystallographic slip during forming.
Investigation of quenching effect on mechanical property and abrasive wear behaviour of high boron cast steel
Authors: Fu H. G. , Wu Z. W. , Xing J. D.
Published: April 2007

The effect of quenching temperature from 900 to 1050°C on the microstructures, mechanical properties and abrasion resistance of modified high born cast steel containing 0·3 wt-%C and 3·0 wt-%B was studied by optical microscopy, scanning electron microscopy, X-ray diffraction analysis, tensile tester, impact tester, hardness tester and abrasion tester. Quenching at 900°C resulted in structures containing a small amount of pearlite. The existence of pearlite led to poor hardness and wear resistance of modified high born cast steel. Quenching at temperatures between 900 and 950°C resulted in the decrease in pearlite and the increase in hardness and abrasion resistance in comparison with 900°C quenching. The metallic matrix all transformed into the martensite quenching at 1000°C; the modified high born cast steel had high hardness, tensile strength, impact toughness and excellent abrasion resistance. The hardness, tensile strength and impact toughness of modified high born cast steel had no obvious change quenching over 1000°C. The increase in quenching temperature also led to the transformation of boride from continuous shape to isolated shape and promoted the coarsening of boride.
Effect of ECAP and annealing treatment on ϵ martensite and damping capacity of Fe–18·39Mn alloy
Authors: Huang S. K. , Wen Y. H. , Li N. , Ding S. , Teng J.
Published: April 2007

The microstructure and damping capacity of Fe–18·39Mn alloy after equal channel angular pressing (ECAP) and annealing treatment were studied. The damping capacity was measured using reversal torsion pendulum. The microstructure was observed using SEM and TEM. The phase structures were determined using XRD. The results indicated that the damping capacity of Fe–18·39Mn alloy all vanished after ECAP and annealing at 600°C, increased rapidly at 700°C, reached the maximum at 900°C and then decreased at 1000°C. All these were ascribed to the change of the size of ϵ martensite plates.
Investigation on patterned structures formed on p-type silicon and its morphological dependence on current density
Authors: Balakrishnan S. , Gun'ko Y. K. , Perova T. S. , Patrick J. , Moore R. A.
Published: April 2007

The electrochemical etching of p-type silicon was carried out at different current densities using aqueous electrolytes on the same resistivity samples. The morphology of the pores, formed at different current densities and etching time, has been characterised using scanning electron microscopy. The present work is centred on the formation of islandlike structures. These structures are uniformly distributed and a possible mechanism for the formation of these structures is discussed. Photoluminescence studies on these structures revealed the microporous nature of the patterns.
Artificial neural network modelling of solidification mode in austenitic stainless steel welds
Authors: Vasudevan M. , Bhaduri A. K. , Raj Baldev , Rao K. Prasad
Published: April 2007

In austenitic stainless steel welds it is necessary to control the weld metal composition to promote primary ferritic mode of solidification for minimising the solidification cracking susceptibility of welds and to reduce the amount of slag formation during arc welding. Modern approach for predicting the solidification mode as a function of weld metal composition is by application of artificial neural network (ANN) based model. In the present work, composition only dependent Bayesian classification neural network model for classification of solidification modes is developed. Nickel was found to exhibit a clear pattern in influencing the solidification mode in austenitic stainless steel welds. Analysis of combined effect of nickel and other alloying elements showed that in addition to nickel, chromium, manganese and nitrogen were the other alloying elements whose concentrations determine the solidification mode in austenitic stainless steel welds. There was good agreement between the model predictions and the experimental data and the accuracy of the model predictions on an independent dataset was determined as 81%.
Varying velocity scan in laser forming of plates
Authors: Shen H. , Zhou J. , Shi Y. J. , Yao Z. Q. , Hu J.
Published: April 2007

Laser forming of metal plates offers the advantages of requiring no external forces, cost reduction and increasing flexibility. It also enables forming of some materials and shapes that are impossible by using the traditional methods. This paper presents a three-dimensional non-linear, indirectly coupled thermal structural model to simulate the process of laser forming of plates. The model is used to investigate the edge effects of the laser bending. To verify the model, bending angles along the scan path simulated are compared with those measured experimentally. The results show that the numerical results are consistent with the experimental observations. The present numerical study shows that if the scan speed varies properly, the edge effect can be reduced significantly.
Natural killer cell–derived human granzyme H induces an alternative, caspase-independent cell-death program
Authors: Fellows Edward , Gil-Parrado Shirley , Jenne Dieter E. , Kurschus Florian C.
Published: April 2007

Granzyme H (GzmH) belongs to a family of 5 human serine proteases that are expressed by cytotoxic immune effector cells. Although GzmH is most closely related to the caspase-activating granzyme B (GzmB), neither a natural substrate nor a role in immune defense reactions has been demonstrated for this orphan granzyme. In rodents, multiple related genes exist, but none of these can be regarded as functional homologs. Here we show that host cells are efficiently killed by GzmH after perforin and streptolysin O–mediated delivery into the cytosol. Dying cells show typical hallmarks of programmed cell death, such as mitochondrial depolarization, reactive oxygen species (ROS) generation, DNA degradation, and chromatin condensation. Contrary to GzmB, cell death by GzmH does not involve the activation of executioner caspases, the cleavage of Bid or inhibitor of caspase-activated DNase (ICAD), or the release of cytochrome c. The high expression levels of GzmH in naive natural killer (NK) cells and its potent killing ability strongly support the role of the protease in triggering an alternative cell-death pathway in innate immunity.
Acute myeloid leukemia with the 8q22;21q22 translocation: secondary mutational events and alternative t(8;21) transcripts
Authors: Peterson Luke F. , Boyapati Anita , Ahn Eun-Young , Biggs Joseph R. , Okumura Akiko Joo , Lo Miao-Chia , Yan Ming , Zhang Dong-Er
Published: April 2007

Nonrandom and somatically acquired chromosomal translocations can be identified in nearly 50% of human acute myeloid leukemias. One common chromosomal translocation in this disease is the 8q22;21q22 translocation. It involves the AML1 (RUNX1) gene on chromosome 21 and the ETO (MTG8, RUNX1T1) gene on chromosome 8 generating the AML1-ETO fusion proteins. In this review, we survey recent advances made involving secondary mutational events and alternative t(8;21) transcripts in relation to understanding AML1-ETO leukemogenesis.
Two‐Photon Imaging of Astrocytic Ca2+ Signaling and the Microvasculature in Experimental Mice Models of Alzheimer's Disease
Authors: TAKANO TAKAHIRO , HAN XIAONING , DEANE RASHID , ZLOKOVIC BERISLAV , NEDERGAARD MAIKEN
Published: April 2007

Abstract:  The sequence of events leading to neurodegeneration in Alzheimer's disease (AD) remains poorly understood. One prominent hypothesis is that neurovascular dysfunction contributes to both disease initiation and progression. Histologic analysis has supported this idea by demonstrating that vascular abnormalities are present early in the disease and most often perivascular amyloid deposits in the microvasculature. Two‐photon in vivo imaging of mouse models of AD represents a unique approach to studying microvascular dysfunction in intact animals. We report here that a subpopulation of mice in early stages of AD (2–4 months) displays instability of vascular tone. Some, but not all animals exhibited oscillatory changes in arteriole diameter and poor vasodilation in response to sensory stimulation. An increased frequency of spontaneous astrocytic Ca2+ increases was noted in animals with unstable vasculature. Because astrocytes recently have been shown to control local microcirculation and contribute to functional hyperemia, we suggest that abnormal astrocytic activity may contribute to vascular instability in AD and thereby to neuronal demise.
Top‐Down Modulation and Normal Aging
Authors: GAZZALEY ADAM , D'ESPOSITO MARK
Published: April 2007

Abstract: Normal aging is characterized by cognitive deficits that cross multiple domains and impair the ability of some older individuals to lead productive, high‐quality lives. One of the primary goals of research in our laboratories is to study age‐related alterations in neural mechanisms that underlie a wide range of cognitive processes so that we may generate a unifying principle of cognitive aging. Top‐down modulation is the mechanism by which we enhance neural activity associated with relevant information and suppress activity for irrelevant information, thus establishing a foundation for both attention and memory processes. We use three converging technologies of human neurophysiology to study top‐down modulation in aging: functional magnetic resonance imaging (fMRI), electroencephalography (EEG), and transcranial magnetic stimulation (TMS). Using these tools we have discovered that healthy older adults exhibit a selective inability to effectively suppress neural activity associated with distracting information and that this top‐down suppression deficit is correlated with their memory impairment. We are now further characterizing the basis of these age‐related alterations in top‐down modulation and investigating interventions to remedy them.
Imaging and CSF Studies in the Preclinical Diagnosis of Alzheimer's Disease
Authors: De LEON M. J. , MOSCONI L. , BLENNOW K. , DeSANTI S. , ZINKOWSKI R. , MEHTA P. D. , PRATICO D. , TSUI W. , LOUIS L. A. SAINT , SOBANSKA L. , BRYS M. , LI Y. , RICH K. , RINNE J. , RUSINEK H.
Published: April 2007

Abstract:  It is widely believed that the path to early and effective treatment for Alzheimer's disease (AD) requires the development of early diagnostic markers that are both sensitive and specific. To this aim, using longitudinal study designs, we and others have examined magnetic resonance imaging (MRI), 2‐fluoro‐2‐deoxy‐d‐glucose‐positron emission tomography (FDG/PET), and cerebrospinal fluid (CSF) biomarkers in cognitively normal elderly (NL) subjects and in patients with mild cognitive impairment (MCI). Such investigations have led to the often replicated findings that structural evidence of hippocampal atrophy as determined by MRI, as well as metabolic evidence from FDG‐PET scan of hippocampal damage, predicts the conversion from MCI to AD. In this article we present a growing body of evidence of even earlier diagnosis. Brain pathology can be detected in NL subjects and used to predict future transition to MCI. This prediction is enabled by examinations revealing reduced glucose metabolism in the hippocampal formation (hippocampus and entorhinal cortex [EC]) as well as by the rate of medial temporal lobe atrophy as determined by MRI. However, neither regional atrophy nor glucose metabolism reductions are specific for AD. These measures provide secondary not primary evidence for AD. Consequently, we will also summarize recent efforts to improve the diagnostic specificity by combining imaging with CSF biomarkers and most recently by evaluating amyloid imaging using PET. We conclude that the combined use of conventional imaging, that is MRI or FDG‐PET, with selected CSF biomarkers incrementally contributes to the early and specific diagnosis of AD. Moreover, selected combinations of imaging and CSF biomarkers measures are of importance in monitoring the course of AD and thus relevant to evaluating clinical trials.
[123I]5‐IA‐85380 SPECT Imaging of β2‐Nicotinic Acetylcholine Receptor Availability in the Aging Human Brain
Authors: MITSIS EFFIE M. , COSGROVE KELLY P. , STALEY JULIE K. , FROHLICH ERIN B. , BOIS FREDERIC , TAMAGNAN GILLES D. , ESTOK KRISTINA M. , SEIBYL JOHN P. , VAN DYCK CHRISTOPHER H.
Published: April 2007

Abstract:  Human postmortem studies have reported decreases with age in high‐affinity nicotine binding in brain. We have been investigating in vivo the availability of the β2‐containing nicotinic acetylcholine receptor (β2‐nAChR) in healthy nonsmokers (18–85 years of age) using [123I]5‐IA‐85380 SPECT imaging. Age and regional β2‐nAChR availability (VT,) have been observed to be inversely correlated in all brain regions analyzed, with decline ranging from 21% (cerebellum) to 36% (thalamus), or by up to 5% per decade of life. Preliminary results have confirmed postmortem reports of age‐related decline in high‐affinity nicotine binding with age and may elucidate the role of β2‐nAChRs in the cognitive decline associated with aging.
Synaptic and Mitochondrial Morphometry Provides Structural Correlates of Successful Brain Aging
Authors: BERTONI‐FREDDARI CARLO , FATTORETTI PATRIZIA , GIORGETTI BELINDA , GROSSI YESSICA , BALIETTI MARTA , CASOLI TIZIANA , Di STEFANO GIUSEPPINA , PERRETTA GEMMA
Published: April 2007

Abstract:  Average synaptic size (S), synaptic numeric density (Nv) and surface density (Sv), average mitochondrial volume, mitochondrial numeric density, and mitochondrial volume density were measured by morphometry in the frontal (FC) and temporal (TC) cortex from adult and old monkeys (Macaca fascicularis). In relation to aging, Sv did not change, while Nv was significantly decreased in TC, but not in FC. S was significantly increased in FC and TC. No significant difference due to age was found with regard to mitochondrial ultrastructure. Considering the functional significance of the above parameters, their substantial age‐related constancy suggests that they may reasonably represent structural correlates of successful brain aging.
Alzheimer Amyloid β‐Peptide A‐β25‐35 Blocks Adenylate Cyclase‐Mediated Forms of Hippocampal Long‐Term Potentiation
Authors: BISEL BLAINE E. , HENKINS KRISTEN M. , PARFITT KAREN D.
Published: April 2007

Abstract:  Progressive memory loss and deposition of amyloid β (Aβ) peptides throughout cortical regions are hallmarks of Alzheimer's disease (AD). Several studies in mice and rats have shown that overexpression of amyloid precursor protein (APP) or pretreatment with Aβ peptide fragments results in the inhibition of hippocampal long‐term potentiation (LTP) as well as impairments in learning and memory of hippocampal‐dependent tasks. For these studies we have investigated the effects of the Aβ25‐35 peptide fragment on LTP induced by adenylate cyclase stimulation followed immediately by application of Mg++‐free aCSF (“chemLTP”). Treatment of young adult slices with the Aβ25‐35 peptide had no significant effect on basal synaptic transmission in area CA1, but treatment with the peptide for 20 min before inducing chemLTP with isoproterenol (ISO; 1 μM) or forskolin (FSK;10 μM) + Mg++‐free aCSF resulted in complete blockade of LTP. In contrast, normal ISO‐chemLTP was observed after treatment with the control peptide Aβ35‐25. The ability of the Aβ25‐35 peptide fragment to block this and other forms of synaptic plasticity may help elucidate the mechanisms underlying hippocampal deficits observed in animal models of AD and/or AD individuals.
Diffusion Tensor Imaging of Normal Appearing White Matter and Its Correlation with Cognitive Functioning in Mild Cognitive Impairment and Alzheimer's Disease
Authors: HUANG JUEBIN , AUCHUS ALEXANDER P.
Published: April 2007

Abstract:  Diffusion tensor imaging (DTI) was used to examine the microstructural integrity of normal appearing white matter (NAWM) in subjects with mild cognitive impairment (MCI) and Alzheimer's disease (AD). Significant frontal, temporal, and parietal white matter diffusion tensor changes were demonstrated in MCI and AD compared with normal controls. These changes were correlated with cognitive functioning, and are consistent with a hypothesized loss of axonal processes in affected regions.
Enhanced Ryanodine‐Mediated Calcium Release in Mutant PS1‐Expressing Alzheimer's Mouse Models
Authors: STUTZMANN GRACE E. , SMITH IAN , CACCAMO ANTONELLA , ODDO SALVATORE , PARKER IAN , LAFERLA FRANK
Published: April 2007

Abstract:  Intracellular Ca2+ signaling involves Ca2+ liberation through both inositol triphosphate and ryanodine receptors (IP3R and RyR). However, little is known of the functional interactions between these Ca2+ sources in either neuronal physiology, or during Ca2+ disruptions associated with Alzheimer's disease (AD). By the use of whole‐cell recordings and 2‐photon Ca2+ imaging in cortical slices we distinguished between IP3R‐ and RyR‐mediated Ca2+ components in nontransgenic (non‐Tg) and AD mouse models and demonstrate powerful signaling interactions between these channels. Ca2+‐induced Ca2+ release (CICR) through RyR contributed modestly to Ca2+ signals evoked by photoreleased IP3 in cortical neurons from non‐Tg mice. In contrast, the exaggerated signals in 3×Tg‐AD and PS1KI mice resulted primarily from enhanced CICR through RyR, rather than through IP3R, and were associated with increased RyR expression levels. Moreover, membrane hyperpolarizations evoked by IP3 in neurons from AD mouse models were even greater than expected simply from the exaggerated Ca2+ signals, pointing to an increased coupling efficiency between cytosolic [Ca2+] and K+ channel regulation. Our results highlight the critical roles of RyR‐mediated Ca2+ signaling in both neuronal physiology and pathophysiology, and point to presenilin‐linked disruptions in RyR signaling as an important genetic factor in AD.
The regulation of genes and genomes by small RNAs
Authors: Ambros Victor , Chen Xuemei
Published: April 2007

A recent Keystone Symposium on `MicroRNAs and siRNAs: Biological Functions and Mechanisms' was organized by David Bartel and Shiv Grewal (and was held in conjunction with `RNAi for Target Validation and as a Therapeutic', organized by Stephen Friend and John Maraganore). The `MicroRNAs and siRNAs' meeting brought together scientists working on diverse biological aspects of small regulatory RNAs, including microRNAs, small interfering RNAs (siRNAs) and Piwi-interacting RNAs (piRNAs and rasiRNAs). Among the themes discussed were the diversity of small regulatory RNAs and their developmental functions,their biogenesis, the identification of their regulatory targets, their mechanisms of action, and their roles in the elaboration of multicellular complexity.
grp(chk1) replication-checkpoint mutations and DNA damage trigger a Chk2-dependent block at theDrosophilamidblastula transition
Authors: Takada Saeko , Kwak Seongae , Koppetsch Birgit S. , Theurkauf William E.
Published: April 2007

The 13 syncytial cleavage divisions that initiate Drosophilaembryogenesis are under maternal genetic control. The switch to zygotic regulation of development at the midblastula transition (MBT) follows mitosis 13, when the cleavage divisions terminate, transcription increases and the blastoderm cellularizes. Embryos mutant for grp, which encodes Checkpoint kinase 1 (Chk1), are DNA-replication-checkpoint defective and fail to cellularize, gastrulate or to initiate high-level zygotic transcription at the MBT. The mnk (also known as loki) gene encodes Checkpoint kinase 2 (Chk2), which functions in DNA-damage signal transduction. We show that mnk grp double-mutant embryos are replication-checkpoint defective but cellularize, gastrulate and activate high levels of zygotic gene expression. We also show that grp mutant embryos accumulate DNA double-strand breaks and that DNA-damaging agents induce a mnk-dependent block to cellularization and zygotic gene expression. We conclude that the DNA-replication checkpoint maintains genome integrity during the cleavage divisions, and that checkpoint mutations lead to DNA damage that induces a novel Chk2-dependent block at the MBT.
tailup, a LIM-HD gene, and Iro-C cooperate inDrosophiladorsal mesothorax specification
Authors: de Navascués Joaquín , Modolell Juan
Published: April 2007

The LIM-HD gene tailup (tup; also known as islet) has been categorised as a prepattern gene that antagonises the formation of sensory bristles on the notum of Drosophila by downregulating the expression of the proneural achaete-scutegenes. Here we show that tup has an earlier function in the development of the imaginal wing disc; namely, the specification of the notum territory. Absence of tup function causes cells of this anlage to upregulate different wing-hinge genes and to lose expression of some notum genes. Consistently, these cells differentiate hinge structures or modified notum cuticle. The LIM-HD co-factors Chip and Ssdp are also necessary for notum specification. This suggests that Tup acts in this process in a complex with Chip and Ssdp. Overexpression of tup, together with araucan, a `pronotum' gene of the iroquois complex (Iro-C),synergistically reinforces the weak capacity of either gene, when overexpressed singly, to induce ectopic notum-like development. Whereas the Iro-C genes are activated in the notum anlage by EGFR signalling, tupis positively regulated by Dpp signalling. Our data support a model in which the EGFR and Dpp signalling pathways, with their respective downstream Iro-C and tup genes, converge and cooperate to commit cells to the notum developmental fate.