bluuebunny/crossref_metadata_2025 huggingface dataset:
Commitment and its theorized determinants: A meta–analysis of the Investment Model
Authors: Le Benjamin , Agnew Christopher R.
Published: March 2003

We conducted a meta–analysis of Rusbult's Investment Model of commitment. Across 52 studies, including 60 independent samples and 11,582 participants, satisfaction with, alternatives to, and investments in a relationship each correlated significantly with commitment to that relationship. Moreover, these three variables collectively accounted for nearly two–thirds of the variance in commitment. Commitment, in turn, was found to be a significant predictor of relationship breakup. Support for the model was obtained in predicting commitment in both relational domains (e.g., commitment to a romantic partnership) and nonrelational domains (e.g., commitment to one's job), but was significantly stronger in relational domains. Additional moderator analyses suggested that the associations between commitment and its theorized bases vary minimally as a function of demographic (e.g., ethnicity) or relational (e.g., duration) factors. We review theoretical strengths and shortcomings of the Investment Model and identify directions for future research.
Juggling Models of Masculinity: Russian‐Jewish Immigrants in the Israeli Army
Authors: Lomsky‐Feder Edna , Rapoport Tamar
Published: March 2003

The present study addresses the question “What is masculinity?” by exploring how male immigrants interpret local masculinity and the models of masculinity they portray while situating themselves in the male hierarchy of the new society. The study is based on “immigration stories” elicited by in‐depth interviews conducted with 43 university students who immigrated to Israel at the beginning of the 1990s from the former Soviet Union. The analysis of the stories reveals that the immigrants employ four major practices (avoidance, mockery, maneuvering, and provocation) that unfasten the takenfor‐granted link between masculinity and army service in the Israeli society, thereby resisting the hegemonic, military model of masculinity in Israel. The immigrants render meaning to their resistance of the indigenous model (“The Warrior”) via the harnessing of cultural models that they carry with them from their native home—“The Russian Soldier” and “The Jewish Man”—without seeking to alter gender power relations as such. They discursively juggle between the three contesting and competing models of masculinity that together constitute a fluid and elusive “interpretative field” of masculinity. Via their interpretative work, the Russian male immigrants reconstitute their masculine identity, seeking to assert their distinctiveness and to receive social legitimation for their different conception of masculinity.
A framework for policy formulation for small‐scale mines: the case of coal in China
Authors: Andrews‐Speed Philip , Zamora Armando , Rogers Christopher D. , Shen Lei , Cao Shelley , Yang Minying
Published: March 2003

The effective management of small‐scale mines is one of the major challenges for governments in the mining sector. Small‐scale mining may bring tangible, short‐term benefits to the communities involved. However, these benefits are frequently outweighed by the costs incurred in terms of illness, injury, pollution, waste of natural resources and market distortions. Governments, international agencies and advisers are generally able to draw up lists of actions which are required to regulate and manage small‐scale mines more effectively, but turning plans into sustained action has proved more difficult. Two aspects of policy implementation are crucial to success: the alignment of interests, and the attitude and effectiveness of government. Using a case study of township and village coal mines in China, this article develops an approach to analysing these issues that could assist regional policy makers and advisers in formulating policy, in identifying key obstacles to policy implementation, and in identifying particular parties which need to be infiuenced or educated in order for the policy to succeed.
The Scientific Status of Projective Techniques
Authors: Lilienfeld Scott O. , Wood James M. , Garb Howard N.
Published: March 2003

Although projective techniques continue to be widely used in clinical and forensic settings, their scientific status remains highly controversial. In this monograph, we review the current state of the literature concerning the psychometric properties (norms, reliability, validity, incremental validity, treatment utility) of three major projective instruments: Rorschach Inkblot Test, Thematic Apperception Test (TAT), and human figure drawings. We conclude that there is empirical support for the validity of a small number of indexes derived from the Rorschach and TAT. However, the substantial majority of Rorschach and TAT indexes are not empirically supported. The validity evidence for human figure drawings is even more limited. With a few exceptions, projective indexes have not consistently demonstrated incremental validity above and beyond other psychometric data. In addition, we summarize the results of a new meta-analysis intended to examine the capacity of these three instruments to detect child sexual abuse. Although some projective instruments were better than chance at detecting child sexual abuse, there were virtually no replicated findings across independent investigative teams. This meta-analysis also provides the first clear evidence of substantial file drawer effects in the projectives literature, as the effect sizes from published studies markedly exceeded those from unpublished studies. We conclude with recommendations regarding the (a) construction of projective techniques with adequate validity, (b) forensic and clinical use of projective techniques, and (c) education and training of future psychologists regarding projective techniques.
We Know Some Things: Parent–Adolescent Relationships in Retrospect and Prospect
Authors: Steinberg Laurence
Published: March 2003

This article examines the most important ideas to have emerged from the last 25 years of research on adolescent development in the family context and suggests some directions for the future. Two major sets of questions organize the review. First, how can we best characterize normative family relationships during adolescence, and, more specifically, is adolescence a time of parent Ã child conflict? Second, how do variations in parent – child relationships affect the developing adolescent? The answer to the first question depends on what is meant by conflict and, more importantly, from whom one gathers data. There is a need for a new perspective on the family, one that emphasizes the different viewpoints and stakes that parents and adolescents bring to their relationship with each other. Special attention should be paid to studies of the mental health of parents of adolescents. With regard to the second question, it is argued that there is enough evidence to conclude that adolescents benefit from having parents who are authoritative: warm, firm, and accepting of their needs for psychological autonomy. Therefore, it would seem most beneficial to institute a systematic, large‐scale, multifaceted, and ongoing public health campaign to educate parents about adolescence, one that draws on the collective resources and expertise of health‐care professionals, scientists, governmental agencies, community organizations, schools, religious institutions, and the mass media.
Globalization, Societal Change, and New Technologies: What They Mean for the Future of Adolescence
Authors: Larson Reed W.
Published: March 2003

Nations around the world are undergoing rapid changes that are altering the nature of adolescence in their societies. This volume examines current trends in adolescent experience across nations, with the objective of identifying emerging problems and opportunities in adolescents' preparation for adulthood. This introduction reviews methods used by futurists and how these methods are applicable to adolescence, and provides an overview of some of the macrochanges that are shaping the societies in which adolescents of the future will live. The macrochanges considered include demographic trends, globalization, trends in government, and changes in technology. Subsequent articles in this volume examine how these and other changes are altering adolescents' transition to adult work, preparation for adult interpersonal lives, civic and community engagement, and health and well‐being. The final article focuses on social policy and is followed by a conclusion with the main points and trends in the volume.
Coping with Family Conflict and Economic Strain: The Adolescent Perspective
Authors: Wadsworth Martha E. , Compas Bruce E.
Published: March 2003

This study tested two models of family economic problems and adolescent psychological adjustment. Using adolescents’ survey data and information regarding school lunch program enrollment, the associations among family SES, perceived economic strain, family conflict, and coping responses were examined in a sample of 364 adolescents from rural New England. Two theoretical models were tested using structural equation modeling — one tested coping as a mediator of the stress – psychopathology relation and the other tested coping as a moderator. Results revealed that family economic hardship was related to aggression and anxiety/depression primarily through two proximal stressors: perceived economic strain and conflict among family members. Family conflict partially mediated the relation between economic strain and adolescent adjustment, and coping further mediated the relation between family conflict and adjustment. These analyses identified two types of coping that were associated with fewer anxiety/depression and aggression problems in the face of these stressors — primary and secondary control coping. Although primary and secondary control coping were associated with fewer adjustment problems, youth who were experiencing higher amounts of stress tended to use less of these potentially helpful coping strategies and used more of the potentially detrimental disengagement coping. The models did not differ according to the age or gender of the adolescents, nor whether they lived with two parents or fewer. No support was found for coping as a moderator of stress. Implications of these findings and suggestions for future research involving coping with economic stressors are reviewed.
Adolescents' and Mothers' Understanding of Children's Rights in the Home
Authors: Ruck Martin D. , Peterson‐Badali Michele , Day David M.
Published: March 2003

Adolescents' and mothers' understanding of children's self‐determination and nurturance rights was examined in the context of the home. In individual interviews, 141 sixth, eighth, and tenth graders and their mothers responded to hypothetical vignettes in which a child story character wished to exercise a right that conflicted with parental practices. For each vignette, participants were asked to judge whether the story character should have the right in question and to provide a justification for their decision. Generally, eighth and tenth graders were more likely than their mothers to endorse requests for self‐determination and less likely than their mothers to support requests for nurturance. Mothers of tenth graders were more likely to support requests for self‐determination and less likely to favor adolescents' request for nurturance in the home than were mothers of sixth and eighth graders. In terms of reasoning, adolescents and mothers were more likely to consider the individuals' rights when discussing self‐determination situations, whereas nurturance situations elicited responses pertaining to participants' understanding of familial roles and relationships. Furthermore, mothers' reasoning about childrenÃs rights reflected sensitivity to the developmental level of their children. The findings are discussed in terms of previous research on the development of children's understanding of rights and adolescent autonomy.
What Adolescents Learn in Organized Youth Activities: A Survey of Self‐Reported Developmental Experiences
Authors: Hansen David M. , Larson Reed W. , Dworkin Jodi B.
Published: March 2003

This research inventoried adolescents' reports on different developmental and negative experiences in organized youth activities, including extracurricular and community‐based activities. High school students' experiences were assessed using a newly developed instrument, the Youth Experiences Survey (YES). These youth reported higher rates of learning experiences in youth activities than in 2 other major contexts of their lives. Youth activities were associated with experiences related to initiative, identity exploration and reflection, emotional learning, developing teamwork skills, and forming ties with community members. The findings also suggest that different youth activities offer distinct patterns of learning experiences. Service, faith‐based, community, and vocational activities were reported to be frequent contexts for experiences related to identity, prosocial norms, and links to adults. Sports were a frequent context for those related to identity work and emotional development.
Measuring Perceptions of Synergistic Circulatory Disease Risk Due to Smoking and the Oral Contraceptive Pill
Authors: French David P. , Gayton Emma L. , Burton Jessica , Thorogood Margaret , Marteau Theresa M.
Published: March 2003

There is evidence that the oral contraceptive pill (OCP) and smoking contribute independently to risk of circulatory disease. There is mixed evidence that the combined risk may be greater than the sum of these factors operating in isolation. Little is known about how the general population views the risks from OCP use, singly and in combination with smoking. Previous attempts at assessing whether the public views risks as operating synergistically have generally found evidence for subadditive models, where the combined risk is less than the sum of factors operating in isolation. However, concerns have been expressed over the validity of the measures of risk perception used. Therefore, this study used three distinct methods of measurement to assess the extent to which 241 undergraduate students perceive the risks of smoking and the OCP, separately and combined, for circulatory disease. For all three methods, respondents read each of four vignettes describing information about a woman's risk factors (with high and low levels of both OCP and smoking), and then estimated risk of circulatory disease using one of the three risk measures. The three measures produced similar ratings. Consistent with the epidemiological evidence, information about smoking had more impact on estimates of overall risk than did information about the OCP. For all three measures, responses were consistent with an additive model of risk from smoking and the OCP. This convergence of results from different methods suggests that all three methods of measurement employed, which all had a large number of response options, may be valid.
Health and Well–Being in the Young Old and Oldest Old
Authors: Smith Jacqui , Borchelt Markus , Maier Heiner , Jopp Daniela
Published: March 2003

Most individuals experience a decline in health status during old age. Paradoxically, there are proposals that older adults nevertheless maintain a positive sense of well–being, an indicator of successful aging. Data from the Berlin Aging Study (BASE: Baltes & Mayer, 1999), a locally representative sample of men and women aged 70 to 100+ (N= 516, M= 85 years), suggest that cumulative health–related chronic life strains set a constraint on the potential of oldest old individuals to experience the positive side of life. The young old in BASE reported significantly higher positive SWB than did the oldest old. Chronic illness and functional impairments (e.g., vision, hearing, mobility, strength) limit well–being especially in very old age.
Appendix C: Potential Effects on Children's Performance of Child Language and Gender
Authors: Bauer Patricia J. , Wenner Jennifer , Dropik Patricia L. , Wewerka Sandi S.
Published: March 2003

In addition to the variables manipulated in this research, children's performance may have been affected by individual and group differences among the participants. This Appendix is a report of analyses of two child variables that might have influenced their performance. First, to determine whether initial differences in facility with language by children in the different delay conditions may have influenced the patterns obtained, we compared children's levels of productive vocabulary at the time of enrollment in the study. Second, we report analyses designed to determine whether there were any differences in performance associatedd with child gender. Although with regard to child gender, some effects obtained, in no case did the findings present substantive qualifications to the major patterns described in the body of the text.
Industrial Companies' Evaluation Criteria in New Product Development Gates
Authors: Hart Susan , Jan Hultink Erik , Tzokas Nikolaos , Commandeur Harry R.
Published: March 2003

This article presents the results of a study on the evaluation criteria that companies use at several gates in the NPD process. The findings from 166 managers suggest that companies use different criteria at different NPD evaluation gates. While such criteria as technical feasibility, intuition and market potential are stressed in the early‐screening gates of the NPD process, a focus on product performance, quality, and staying within the development budget are considered of paramount importance after the product has been developed. During and after commercialization, customer acceptance and satisfaction and unit sales are primary considerations.

In addition, based on the performance dimensions developed by Griffin and Page (1993), we derive patterns of use of various evaluative dimensions at the NPD gates. Our results show that while the market acceptance dimension permeates evaluation at all the gates in the NPD process, the financial dimension is especially important during the business analysis gate and after‐market launch. The product performance dimension figures strongly in the product and market testing gates. The importance of our additional set of criteria (i.e., product uniqueness, market potential, market chance, technical feasibility, and intuition) decreases as the NPD process unfolds. Overall the above pattern of dimensions' usage holds true for both countries in which we collected our data, and across firms of different sizes, holding different market share positions, with different NPD drivers, following different innovation strategies, and developing different types of new products. The results also are stable for respondents that differ in terms of expertise and functional background.

The results of this study provide useful guidelines for project selection and evaluation purposes and therefore can be helpful for effective investment decision‐making at gate‐meetings and for project portfolio management. We elaborate on these guidelines for product developers and marketers wishing to employ evaluation criteria in their NPD gates, and we discuss directions for further research.
To Manage Is to Govern
Authors: Feldman Martha S. , Khademian Anne M.
Published: March 2003

Governance structures constrain and enable the actions of public managers. Principal–agent theory has played a dominant role in our understanding of governance structures. This theory suggests that politicians create relatively static governance structures in a top–down fashion and hold managers accountable for mandated results. In other words, public managers are influenced by governance structures but do not affect governance structures. However, we argue that public managers do affect governance structures, and, in order to understand how this influence takes place, we need a new way of thinking about governance structures. We propose thinking about governance structures as relationships created through the interactions of people in different and reciprocal roles that are relatively dynamic. Public managers are an important source of the multiple, reciprocal, and dynamic interactions that produce governance (relationship) structures. As such, managers are accountable not only for policy outcomes, but also for the appropriateness of the relationships they create and support.
The Ex–Dividend Pricing of REITs
Authors: Hardin III William G. , Liano Kartono , Huang Gow–cheng
Published: March 2003

Past studies have shown that ex–dividend stock prices are not fully reflective of dividend payments. A tax–induced clientele effect and micromarket limitations in stock pricing have been used to explain this pricing anomaly. This study focuses on the ex–dividend behavior of real estate investment trusts (REITs). Due to a low correlation between dividend size and dividend yield, REITs permit a cleaner examination of a tax–induced clientele effect. The results indicate that tick constraints in pricing ex–dividend stocks create the appearance of a tax–induced clientele effect in REITs when none should exist.
The Social Adaptation of Children of Mexican Immigrants: Educational Aspirations Beyond Junior High School
Authors: St–Hilaire Aonghas
Published: March 2003

Objective. This article draws on the concept of segmented assimilation to analyze the values toward, aspirations for, and realistic expectations of pursuing formal education among Mexican–origin students in southern California. Methods. Survey data inform the analyses, which include regression of educational aspirations and expectations on a series of potentially significant independent variables. Results. The evidence of segmented assimilation is mixed. Informants are nearly unanimous in professing positive values toward formal education. However, length of residency in the United States is negatively and fluent bilingualism in Spanish and English is positively associated with educational aspirations and expectations. Conclusions. At the cusp of entering high school, Mexican–origin students profess positive educational values, aspirations, and expectations, belying documented elevated rates of high school dropout and low rates of college attendance.
Have Americans' Attitudes Become More Polarized?—An Update*
Authors: Evans John H.
Published: March 2003

Objective I examine polarization in public opinion using the method of DiMaggio, Evans, and Bryson (DEB) (1996), but go further than DEB by using newly available years of survey data.

Method Like DEB, I derive aggregate distributional parameters for social groups in each year of the surveys, and then regress the year of the surveys on each parameter.

Results As in DEB's original paper, there is little evidence of general polarization in attitudes between the early 1970s and today. However, while DEB found some evidence that polarization in the public may be the result of polarization in our political system, with the additional years of data this conclusion is inescapable.

Conclusions Although political scientists have recently found polarization among our elected officials on economic issues, it seems clear that members of the public who identify with the partisan labels of our political system are becoming polarized on moral issues.
What Drives Firm‐Level Stock Returns?
Authors: Vuolteenaho Tuomo
Published: March 2003

I use a vector autoregressive model (VAR) to decompose an individual firm's stock return into two components: changes in cash‐flow expectations (i.e., cash‐flow news) and changes in discount rates (i.e., expected‐return news). The VAR yields three main results. First, firm‐level stock returns are mainly driven by cash‐flow news. For a typical stock, the variance of cash‐flow news is more than twice that of expected‐return news. Second, shocks to expected returns and cash flows are positively correlated for a typical small stock. Third, expected‐return‐news series are highly correlated across firms, while cash‐flow news can largely be diversified away in aggregate portfolios.
The Effects of Banking Mergers on Loan Contracts
Authors: Sapienza Paola
Published: March 2003

This paper studies the effects of banking mergers on individual business borrowers. Using information on individual loan contracts between banks and companies, I analyze the effect of banking consolidation on banks' credit policies. I find that inmarket mergers benefit borrowers if these mergers involve the acquisition of banks with small market shares. Interest rates charged by the consolidated banks decrease, but as the local market share of the acquired bank increases, the efficiency effect is offset by market power. Mergers have different distributional effects across borrowers. When banks become larger, they reduce the supply of loans to small borrowers.
Does Corporate Diversification Destroy Value?
Authors: Graham John R. , Lemmon Michael L. , Wolf Jack G.
Published: March 2003

We analyze several hundred firms that expand via acquisition and/or increase their number of business segments. The combined market reaction to acquisition announcements is positive but acquiring firm excess values decline after the diversifying event. Much of the excess value reduction occurs because our sample firms acquire already discounted business units, and not because diversifying destroys value. This implies that the standard assumption that conglomerate divisions can be benchmarked to typical stand‐alone firms should be carefully reconsidered. We also show that excess value does not decline when firms increase their number of business segments because of pure reporting changes.
The Volatility and Price Sensitivities of Managerial Stock Option Portfolios and Corporate Hedging
Authors: Knopf John D. , Nam Jouahn , Thornton John H.
Published: March 2003

We use estimates of the Black—Scholes sensitivity of managers' stock option portfolios to stock return volatility and the sensitivity of managers' stock and stock option portfolios to stock price to test the relationship between managers' risk preferences and hedging activities. We find that as the sensitivity of managers' stock and stock option portfolios to stock price increases, firms tend to hedge more. However, as the sensitivity of managers' stock option portfolios to stock return volatility increases, firms tend to hedge less.
Liquidity Provision and the Organizational Form of NYSE Specialist Firms
Authors: Coughenour Jay F. , Deli Daniel N.
Published: March 2003

We examine the influence of NYSE specialist firm organizational form on the nature of liquidity provision. We compare closely held firms whose specialists provide liquidity with their own capital to widely held firms whose specialists provide liquidity with diffusely owned capital. We argue that specialists using their own capital have a greater incentive and ability to reduce adverse selection costs, but face a greater cost of capital. Differences in the proportion of spreads due to adverse selection costs, large trade frequency, the sensitivity between depth and spreads, and price stabilization support this argument.
Dividends, Share Repurchases, and the Substitution Hypothesis
Authors: Grullon Gustavo , Michaely Roni
Published: March 2003

We show that repurchases have not only became an important form of payout for U.S. corporations, but also that firms finance their share repurchases with funds that otherwise would have been used to increase dividends. We find that young firms have a higher propensity to pay cash through repurchases than they did in the past and that repurchases have become the preferred form of initiating a cash payout. Although large, established firms have generally not cut their dividends, they also show a higher propensity to pay out cash through repurchases. These findings indicate that firms have gradually substituted repurchases for dividends. Our results also suggest that before 1983, regulatory constraints inhibited firms from aggressively repurchasing shares.
Long‐Run Performance following Private Placements of Equity
Authors: Hertzel Michael , Lemmon Michael , Linck James S. , Rees Lynn
Published: March 2003

Public firms that place equity privately experience positive announcements effects, with negative post‐announcement stock‐price performance. This finding is inconsistent with the underreaction hypothesis. Instead, it suggests that investors are overoptimistic about the prospects of firms issuing equity, regardless of the method of issuance. Further, in contrast to public offerings, private issues follow periods of relatively poor operating performance. Thus, investor overoptimism at the time of private issues is not due to the behavioral tendency to overweight recent experience at the expense of long‐term averages.
Entrepreneurship and Bank Credit Availability
Authors: Black Sandra E. , Strahan Philip E.
Published: March 2003

The literature is divided on the expected effects of increased competition and consolidation in the financial sector on the supply of credit to relationship borrowers. This paper tests whether policy changes fostering competition and consolidation in U.S. banking helped or harmed entrepreneurs. We find that the rate of new incorporations increases following deregulation of branching restrictions, and that deregulation reduces the negative effect of concentration on new incorporations. We also find the formation of new incorporations increases as the share of small banks decreases, suggesting that diversification benefits of size outweigh the possible comparative advantage small banks may have in forging relationships.
Asset Pricing with Conditioning Information: A New Test
Authors: Wang Kevin Q.
Published: March 2003

This paper presents a new test of conditional versions of the Sharpe‐Lintner CAPM, the Jagannathan and Wang (1996) extension of the CAPM, and the Fama and French (1993) three‐factor model. The test is based on a general nonparametric methodology that avoids functional form misspecification of betas, risk premia, and the stochastic discount factor. Our results provide a novel view of empirical performance of these models. In particular, we find that a nonparametric version of the Fama and French model performs well, even when challenged by momentum portfolios.
Disassembly of Human Immunodeficiency Virus Type 1 Cores In Vitro Reveals Association of Nef with the Subviral Ribonucleoprotein Complex
Authors: Forshey Brett M. , Aiken Christopher
Published: March 2003

The human immunodeficiency virus type 1 (HIV-1) virulence factor Nef enhances viral infectivity in single-cycle infection assays and accelerates HIV-1 replication in vitro. It has been reported that the effects of Nef are mediated early after viral entry and before the completion of reverse transcription, as viral DNA synthesis is strongly attenuated during infection by Nef-defective virions. Our previous work has demonstrated that Nef is associated with mature HIV-1 cores, implicating Nef in the regulation of HIV-1 core stability. Here we report a comparative analysis of HIV-1 cores isolated from wild-type and Nef-defective particles. We observed no effect of Nef on HIV-1 core structure or stability; however, Nef cosedimented with a subviral ribonucleoprotein complex following dissociation of CA. These results indicate that Nef interacts tightly with an internal component of the HIV-1 core. They further suggest that virion-associated Nef may facilitate an early step in HIV-1 infection following dissociation of the viral capsid in the target cell.
HADRON SPECTROSCOPY WITH CLEO DATA
Authors: Urner D.
Published: March 2003

The CLEO collaboration will explore the charm sector starting 2003. It is foreseen to collect on the order of 6 million [Formula: see text] pairs, 300000 [Formula: see text] pair at threshold and one billion J/ψ decays. High precision charm data will enable us to validate upcoming lattice QCD calculations that are expected to produce 1-3% errors for some non-perturbative QCD quantities. Virtually background free, they will provide interesting decay mechanisms to explore light meson spectroscopy. The radiative J/ψ decays will be the first high statistics data set well suited for meson spectroscopy between 1600 and 3000 MeV. Together with the already existing data from the ϒ resonances, data sets for a large number of decay mechanisms will be available, which, combined, can be used to extract the nature of many resonances.
A NOTE ON THE TRIPLE-ZERO LINEAR DEGENERACY: NORMAL FORMS, DYNAMICAL AND BIFURCATION BEHAVIORS OF AN UNFOLDING
Authors: FREIRE E. , GAMERO E. , RODRÍGUEZ-LUIS A. J. , ALGABA A.
Published: March 2003

This paper is devoted to the analysis of bifurcations in a three-parameter unfolding of a linear degeneracy corresponding to a triple-zero eigenvalue. We carry out the study of codimension-two local bifurcations of equilibria (Takens–Bogdanov and Hopf-zero) and show that they are nondegenerate. This allows to put in evidence the presence of several kinds of bifurcations of periodic orbits (secondary Hopf,…) and of global phenomena (homoclinic, heteroclinic). The results obtained are applied in the study of the Rössler equation.
AN EQUATION FOR GENERATING CHAOS AND ITS MONOLITHIC IMPLEMENTATION
Authors: ELWAKIL A. S. , SALAMA K. N. , KENNEDY M. P.
Published: March 2003

We propose a simple continuous-time system for chaos generation based on a third-order abstract canonical mathematical model. Nonlinearity in this model is introduced by a bipolar switching constant, which reflects the behavior of a digital inverter. A simple area efficient implementation of the system in a 1.2 μ CMOS process is presented. Experimental results from a tested chip are shown.
AN EXPERIMENTAL SUPPRESSION OF SPATIAL INSTABILITY IN ONE-WAY OPEN COUPLED CHUA'S CIRCUITS
Authors: IMAI TAKUYA , KONISHI KEIJI , KOKAME HIDEKI , HIRATA KENTARO
Published: March 2003

This letter shows an experimental suppression of spatial instability in one-way open coupled Chua's circuits. A continuous-time version of the decentralized delayed feedback method is used for a suppression scheme. Furthermore, we confirm that the control method also succeeds in suppressing chaotic behavior in the coupled circuits.
CONTROL OF COMPLEX PEAK-TO-PEAK DYNAMICS
Authors: PICCARDI CARLO , RINALDI SERGIO
Published: March 2003

The paper illustrates a method for the design of suitable controllers of chaotic systems characterized by complex peak-to-peak dynamics, namely by a recursive relationship between consecutive peaks (relative maxima) of a scalar output variable. For such systems, a reduced model can be defined which, in general, is a hybrid model composed of a one-dimensional map and a finite-state automaton. The issues related to the identification and control of such a reduced model are discussed with the help of three applications: the Chua's circuit, a market with advertizing, and a CO2laser.
ESTIMATING THE APPROXIMATION ERROR IN LEARNING THEORY
Authors: SMALE STEVE , ZHOU DING-XUAN
Published: March 2003

Let B be a Banach space and (ℋ,‖·‖ℋ) be a dense, imbedded subspace. For a ∈ B, its distance to the ball of ℋ with radius R (denoted as I(a, R)) tends to zero when R tends to infinity. We are interested in the rate of this convergence. This approximation problem arose from the study of learning theory, where B is the L2 space and ℋ is a reproducing kernel Hilbert space.

The class of elements having I(a, R) = O(R-r) with r > 0 is an interpolation space of the couple (B, ℋ). The rate of convergence can often be realized by linear operators. In particular, this is the case when ℋ is the range of a compact, symmetric, and strictly positive definite linear operator on a separable Hilbert space B. For the kernel approximation studied in Learning Theory, the rate depends on the regularity of the kernel function. This yields error estimates for the approximation by reproducing kernel Hilbert spaces. When the kernel is smooth, the convergence is slow and a logarithmic convergence rate is presented for analytic kernels in this paper. The purpose of our results is to provide some theoretical estimates, including the constants, for the approximation error required for the learning theory.
Analysis of Breast Cancer Mortality in the US—1975 to 2019
Authors: Caswell-Jin Jennifer L. , Sun Liyang P. , Munoz Diego , Lu Ying , Li Yisheng , Huang Hui , Hampton John M. , Song Juhee , Jayasekera Jinani , Schechter Clyde , Alagoz Oguzhan , Stout Natasha K. , Trentham-Dietz Amy , Lee Sandra J. , Huang Xuelin , Mandelblatt Jeanne S. , Berry Donald A. , Kurian Allison W. , Plevritis Sylvia K.
Published: January 2024

Importance

Breast cancer mortality in the US declined between 1975 and 2019. The association of changes in metastatic breast cancer treatment with improved breast cancer mortality is unclear.

Objective

To simulate the relative associations of breast cancer screening, treatment of stage I to III breast cancer, and treatment of metastatic breast cancer with improved breast cancer mortality.

Design, Setting, and Participants

Using aggregated observational and clinical trial data on the dissemination and effects of screening and treatment, 4 Cancer Intervention and Surveillance Modeling Network (CISNET) models simulated US breast cancer mortality rates. Death due to breast cancer, overall and by estrogen receptor and ERBB2 (formerly HER2) status, among women aged 30 to 79 years in the US from 1975 to 2019 was simulated.

Exposures

Screening mammography, treatment of stage I to III breast cancer, and treatment of metastatic breast cancer.

Main Outcomes and Measures

Model-estimated age-adjusted breast cancer mortality rate associated with screening, stage I to III treatment, and metastatic treatment relative to the absence of these exposures was assessed, as was model-estimated median survival after breast cancer metastatic recurrence.

Results

The breast cancer mortality rate in the US (age adjusted) was 48/100 000 women in 1975 and 27/100 000 women in 2019. In 2019, the combination of screening, stage I to III treatment, and metastatic treatment was associated with a 58% reduction (model range, 55%-61%) in breast cancer mortality. Of this reduction, 29% (model range, 19%-33%) was associated with treatment of metastatic breast cancer, 47% (model range, 35%-60%) with treatment of stage I to III breast cancer, and 25% (model range, 21%-33%) with mammography screening. Based on simulations, the greatest change in survival after metastatic recurrence occurred between 2000 and 2019, from 1.9 years (model range, 1.0-2.7 years) to 3.2 years (model range, 2.0-4.9 years). Median survival for estrogen receptor (ER)–positive/ERBB2-positive breast cancer improved by 2.5 years (model range, 2.0-3.4 years), whereas median survival for ER−/ERBB2− breast cancer improved by 0.5 years (model range, 0.3-0.8 years).

Conclusions and Relevance

According to 4 simulation models, breast cancer screening and treatment in 2019 were associated with a 58% reduction in US breast cancer mortality compared with interventions in 1975. Simulations suggested that treatment for stage I to III breast cancer was associated with approximately 47% of the mortality reduction, whereas treatment for metastatic breast cancer was associated with 29% of the reduction and screening with 25% of the reduction.
Ligand‐Selective Targeting of Macrophage Hydrogel Elicits Bone Immune‐Stem Cell Endogenous Self‐Healing Program to Promote Bone Regeneration
Authors: Wang Jiahao , Zhang Liang , Wang Lingjun , Tang Jincheng , Wang Wei , Xu Yichang , Li Ziang , Ding Zhouye , Jiang Xinzhao , Xi Kun , Chen Liang , Gu Yong
Published: January 2024

Targeting macrophages can facilitate the site‐specific repair of critical bone defects. Herein, a composite hydrogel, gelatin‐Bletilla striata polysaccharide‐mesoporous bioactive glass hydrogel (GBMgel), is constructed via the self‐assembly of mesoporous bioactive glass on polysaccharide structures, through the Schiff base reaction. GBMgel can efficiently capture macrophages and drive the recruitment of seed stem cells and vascular budding required for regeneration in the early stages of bone injury, and the observed sustained release of inorganic silicon ions further enhances bone matrix deposition, mineralization, and vascular maturation. Moreover, the use of macrophage‐depleted rat calvarial defect models further confirms that GBMgel, with ligand‐selective macrophage targeting, increases the bone regeneration area and the proportion of mature bone. Mechanistic studies reveal that GBMgel upregulates the TLR4/NF‐κB and MAPK macrophage pathways in the early stages and the JAK/STAT3 pathway in the later stages; thus initiating macrophage polarization at different time points. In conclusion, this study is based on the endogenous self‐healing properties of bone macrophages, which enhances stem cell homing, and provides a research and theoretical basis upon which bone tissue can be reshaped and regenerated using the body's immune power, providing a new strategy for the treatment of critical bone defects.
High Performance Self‐Powered and Vis–Infrared Broadband Photodetectors Based on MoTe2/InSe Van der Waals Heterostructure
Authors: He Sixian , Feng Pu , Du Yuan , Ma Yupeng , Dang Congcong , Shan Aidang , Zhao Liancheng , Wei Tian‐Ran , Li Ming , Gao Liming
Published: January 2024

Self‐powered and broadband photodetectors have important applications in modern technologies and have garnered significant research interest with the increasing concern for green and energy‐saving. The emerging 2D materials InSe is considered to be a promising candidate for next‐generation photodetectors due to the high carrier mobility, excellent photoelectric response, and flexibility. However, due to its weak absorption of infrared light, it remains a challenging task to achieve high‐performance, self‐powered, and broadband photodetection. Here, a MoTe2/InSe van der Waals heterostructure (vdWH) device is successfully constructed. Benefiting from the unique band alignment of the heterostructure, a strong built‐in electric field is formed. Excitingly, the device exhibits excellent photovoltaic performance with a large open voltage and short circuit current of 390.19 mV and 20.32 nA, respectively. In particular, in self‐powered mode, the responsivity (R) is up to 433.88 mA W−1 and the specific detectivity (D*) reaches 1.65 × 1012 Jones under 405 nm irradiation. Meanwhile, an ultrahigh Ilight/Idark ratio over 104, a fast response speed of 99/117 µs, and a broadband photoresponse range from 405 to 980 nm are achieved. The device demonstrates excellent comprehensive self‐powered photodetection performance. This work reveals the great potential of the MoTe2/InSe vdWH for high‐performance, broadband, and self‐powered photodetection.
Chiral Multidentate Ligand Facilitating Perovskite Nanocrystals with Circularly Polarized Luminescence and Chiral Assembly
Authors: Chen Shuhua , Fu Jie , Zhang Congyang , Hu Yiqi , Qiu Yinghua , Chen Jinxing , Zhang Qiao , Cao Muhan
Published: January 2024

Chiral ligand modification has emerged as a promising route to confer intrinsic chirality in perovskite nanocrystals (NCs), thereby imparting them with optically active properties and rendering great superiority in the next generation of circularly polarized luminescence. However, the functionalization of chiral ligand is not fully explored and the underlying mechanism governing chirality transfer remains elusive. Herein, tryptophan (Try), a naturally occurring chiral amino acid, is verified to serve as multidentate chiral ligands attaching on the surface of perovskite NCs. Such strong coordination favors the chirality imprinting on the electronic state of CsPbBr3, resulting in notable circular dichroism features and circularly polarized luminescence with a maximum glum of 2.3 × 10−3. It is intriguing that the intermolecular interaction between Try ligands anchored on two neighboring NCs contribute to chiral optical properties as well. The RDG‐NCI analysis have confirmed the hydrogen bond between the amine and carboxylic groups on chiral Try, which may drive the chiral assembly of perovskite NCs.
RNF43 Inactivation Enhances the B‐RAF/MEK Signaling and Creates a Combinatory Therapeutic Target in Cancer Cells
Authors: Hsu Shih‐Han , Tsai Ya‐Li , Wang Yeng‐Tseng , Shen Che‐Hung , Hung Yu‐Hsuan , Chen Li‐Tzong , Hung Wen‐Chun
Published: January 2024

RING finger 43 (RNF43), a RING‐type E3 ubiquitin ligase, is a key regulator of WNT signaling and is mutated in 6–10% of pancreatic tumors. However, RNF43‐mediated effects remain unclear, as only a few in vivo substrates of RNF43 are identified. Here, it is found that RNF43‐mutated pancreatic cancer cells exhibit elevated B‐RAF/MEK activity and are highly sensitive to MEK inhibitors. The depletion of RNF43 in normal pancreatic ductal cells also enhances MEK activation, suggesting that it is a physiologically regulated process. It is confirmed that RNF43 ubiquitinates B‐RAF at K499 to promote proteasome‐dependent degradation, resulting in reduced MEK activity and proliferative ability in cancer cells. In addition, phosphorylation of B‐RAF at T491 suppresses B‐RAF ubiquitination by decreasing the interaction between RNF43 and B‐RAF. Mutations at K499 in B‐RAF are identified in various cancer types. MEK and WNT inhibitors synergistically suppress the growth of RNF43‐mutated pancreatic cancer cells in vitro and in vivo. Collectively, the research reveals a novel mechanism by which RNF43 inhibits B‐RAF/MEK signaling to suppress tumor growth and provide a new strategy for the treatment of RNF43‐inactivated pancreatic cancer.
Tough Hydrogels for Load‐Bearing Applications
Authors: Petelinšek Nika , Mommer Stefan
Published: January 2024

Tough hydrogels have emerged as a promising class of materials to target load‐bearing applications, where the material has to resist multiple cycles of extreme mechanical impact. A variety of chemical interactions and network architectures are used to enhance the mechanical properties and fracture mechanics of hydrogels making them stiffer and tougher. In recent years, the mechanical properties of tough, high‐performance hydrogels have been benchmarked, however, this is often incomplete as important variables like water content are largely ignored. In this review, the aim is to clarify the reported mechanical properties of state‐of‐the‐art tough hydrogels by providing a comprehensive library of fracture and mechanical property data. First, common methods for mechanical characterization of such high‐performance hydrogels are introduced. Then, various modes of energy dissipation to obtain tough hydrogels are discussed and used to categorize the individual datasets helping to asses the material's (fracture) mechanical properties. Finally, current applications are considered, tough high‐performance hydrogels are compared with existing materials, and promising future opportunities are discussed.
Electro‐Sorting Create Heterogeneity: Constructing A Multifunctional Janus Film with Integrated Compositional and Microstructural Gradients for Guided Bone Regeneration
Authors: Lei Miao , Liao Haitao , Wang Shijia , Zhou Hang , Zhu Jianwei , Wan Haoran , Payne Gregory F. , Liu Changsheng , Qu Xue
Published: January 2024

Biology remains the envy of flexible soft matter fabrication because it can satisfy multiple functional needs by organizing a small set of proteins and polysaccharides into hierarchical systems with controlled heterogeneity in composition and microstructure. Here, it is reported that controlled, mild electronic inputs (<10 V; <20 min) induce a homogeneous gelatin‐chitosan mixture to undergo sorting and bottom‐up self‐assembly into a Janus film with compositional gradient (i.e., from chitosan‐enriched layer to chitosan/gelatin‐contained layer) and tunable dense‐porous gradient microstructures (e.g., porosity, pore size, and ratio of dense to porous layers). This Janus film performs is shown multiple functions for guided bone regeneration: the integration of compositional and microstructural features confers flexible mechanics, asymmetric properties for interfacial wettability, molecular transport (directional growth factor release), and cellular responses (prevents fibroblast infiltration but promotes osteoblast growth and differentiation). Overall, this work demonstrates the versatility of electrofabrication for the customized manufacturing of functional gradient soft matter.