bluuebunny/crossref_metadata_2025 huggingface dataset:
Child support and the postdivorce economic well-being of mothers, fathers, and children
Authors: Bartfeld Judi
Published: March 2007

This article provides national estimates of the current and potential impact of private child support transfers on the economic well-being of custodial and noncustodial families following marital dissolution. Mothers and children fare dramatically worse than fathers after marital dissolution; these differences, however, would be much more pronounced in the absence of private child support. Simulations of four existing child support guidelines show that substantial increases in economic well-being among mother-custody families are possible within the structure of the existing child support system, with minimal impact on poverty among nonresident fathers. Under all of these guidelines, however, custodial-mother families would continue to fare substantially worse than nonresident fathers.
Credit programs for the poor and reproductive behavior in low-income countries: Are the reported causal relationships the result of heterogeneity bias?
Authors: Pin Mark M. , Khandker Shahidur R. , Mckernan Signe-Mary , Latif M. Abdul
Published: March 2007

Group-based lending programs for the poor have drawn much attention recently. As many of these programs target women, an important research question is whether program participation significantly changes reproductive behavior and whether the gender of the participant matters. Using survey data from 87 Bangladeshi villages, we estimate the impact of female and male participation in group-based credit programs on reproductive behavior while attending to issues of self-selection and endogeneity. Wefind no evidence that women s participation in group-based credit programs increases contraceptive use or reduces fertility. Men So participation reduces fertility and may slightly increase contraceptive use.
Quality, accessibility, and contraceptive use in rural tanzania
Authors: Mroz Thomas A. , Bollen Kenneth A. , Speizer Ilene S. , Mancini Dominic J.
Published: March 2007

We examine how informants’reports on community perceptions of the quality and accessibility offamily planningfacilities relate to the use of modern contraceptives by individuals in rural Tanzania. Using information on individual-level contraceptive use in conjunction with community-level information on the accessibility and quality of family planning facilities, we employ two distinct statistical procedures to illustrate the impacts of accessibility and quality on contraceptive use. Both procedures treat the community-level variables as imperfect indicators of characteristics of the facilities, and they yield nearly identical implications. Wefind that a communitylevel, subjective perception of a family planning facility s quality has a significant impact on community members’ contraceptive use whereas other community measures such as time, distance, and subjective perception of accessibility have trivial and insignificant direct impacts, net of the control variables. Future research that uncovers the determinants of perceptions of both community-level and individual-level quality could provide key insights for developing effective and efficientfamily planning programs.
Racial inequality in active life among adult americans
Authors: Hayward Mark D. , Heron Melonie
Published: March 2007

Is a shorter life with more years lived in poor health a defining attribute of the life cycle of disadvantaged groups? Based on the J990 5% Public Use Microdata Survey, we develop life table models of healthy (or active) life for the major racial groups, by sex, in the United States. The analysis underscores the complexity of the relationship between morbidity and mortality in the population. For Asians, longer life is associated with fewer years lived in poor health. In contrast, Native Americans’ relatively longer lives are accompanied by extended periods of chronic health problems. of all racial groups, blacks live the fewest years, and they live a high proportion of those years with a chronic health problem. Hispanics also live substantially fewer years, yet the period of life they spend with a health problem is relatively compressed. Racial differences in the link between morbidity and mortality point to the importance of investigating how chronic diseases and disease prevention and treatment are related to active life across the population subgroups.
Public assistance receipt among immigrants and natives: How the unit of analysis affects research findings
Authors: Van Hook Jennifer , Glick Jennifer E. , Bean Frank D.
Published: March 2007

Differences between immigrant and native households in rates of welfare receipt depend on nativity differences in individual-level rates of receipt, in household size, in mean number of recipients in receiving households, and in household nativity composition. We present algebraic derivations of these relationships and use data from the 1990 and 1991 panels of the Survey of Income and Program Participation to examine empirically the extent to which levels of welfare receipt for immigrants and natives are sensitive to the use of household-, family-, or individual-level units of analysis or presentation. The findings show that nativity differences are statistically significant only at the level of larger units. The results also indicate that if immigrants and natives had identical living arrangements, immigrants’ household-level receipt of Supplemental Security Income would significantly exceed natives’ receipt even more than it actually does, but the nativity difference in receipt of Aid to Families with Dependent Children (AFDC) would reverse directions. Moreover, the level of AFDC receipt of immigrant households falls significantly below that of native households when native-born children living in households headed by immigrants are treated as if they were foreign born.
How much do we count? interpretation and error-making in the decennial census
Authors: Iversen Roberta Rehner , Furstenberg Frank F. , Belzer Alisa A.
Published: March 2007

Following a critique of the 1990 decennial census procedures, we conducted a field study among low-income, inner-city residents in 1991 to examine how they conceptualized and managed the civic task of census response. Interpretations about the purpose and meaning of the census, about commitment to the task, and about connection to government, singly and together with literacy skills (e.g., reading and general literacy competence), were associated with errors that are not detectable by evaluative methodologies used regularly by the Census Bureau. The validity and reliability of census data, and possibly other self-administered survey research. will be increased by greater use of knowledge about both interpretation and literacy skills informulating data collection procedures.
Demography and the environment
Authors: Pebley Anne R.
Published: March 2007

Demographers' interest in the environment has generally been enmeshed in broader issues of population growth and economic development. Empirical research by demographers on environmental issues other than natural-resource constraints is limited. In this paper, I briefly review past demographic thinking about population and the environment and suggest reasons for the limited scope of demographic research in this area. Next, I describe more recent demographic research on the environment and suggest several newer areas for demographic research. Finally, I consider the future of research on the environment in the field of demography.
Deceleration in the age pattern of mortality at olderages
Authors: Horiuchi Shiro , Wilmoth John R.
Published: March 2007

The rate of mortality increase with age tends to slow down at very old ages. One explanation proposed for this deceleration is the selective survival of healthier individuals to older ages. Data on mortality in Sweden and Japan are generally compatible with three predictions of this hypothesis: (1) decelerations for most major causes of death; (2) decelerations starting at younger ages for more “selective” causes; and (3) a shift of the deceleration to older ages with declining levels of mortality. A parametric model employed to illustrate the third prediction relies on the distinction between senescent and background mortality. This dichotomy, though simplistic, helps to explain the observed timing of the deceleration.
A methodology for identifying married couples in medicare data: Mortality, morbidity, and health care use among the married elderly
Authors: Iwashyna Theodore J. , Zhang James X. , Lauderdale Diane S. , Christakis Nicholas A.
Published: March 2007

Wedescribe a method for the development of cohorts of up to three quarters of the 14 million married couples aged 65 and over in the United States. The health care experiences, illness histories, and mortality of these identified couples can be assessed longitudinally using Medicare data. We summarize strengths and limitations of using data from Medicare administrative records for the study of marriage, health, and aging. We illustrate the method by demonstrating substantial differences in survival in a cohort of hospice patients as a function of not only the patient's own diagnosis and illness burden but also the patient's spouse's illness burden.
Contraceptive use in South Africa under apartheid
Authors: Kaufman Carol E.
Published: March 2007

In this paper, patterns of contraceptive use among black South African women in the late 1980s are examined. Multilevel logit models are used to evaluate the extent to which segregation of the African population into homelands gave rise to uneven patterns of contraceptive use; how this pattern was shaped by variations in family-planning acceptability; and the way in which the system of male labor migration and social and economic inequities across communities affected women's use of contraceptives. Results show that variation in contraceptive use across homeland areas diminished with the addition of community controls for development and migration. Controlling for unobserved heterogeneity indicated that localized conditions could offset the advantages or disadvantages of living in a former homeland.
The long-term impact of parents' childbearing decisions on children's self-esteem
Authors: Axinn William G. , Barber Jennifer S. , Thornton Arland
Published: March 2007

We examine the long-term impact of parents' childbearing decisions on children's self-esteem. We focus on subjective aspects of the home environment in the creation of children's internalized sense of self-worth. Unique 23-year family panel data combining measures of mothers' childbearing, mothers' childbearing intentions, and children's self-esteem allow us to examine the overall links between parents' childbearing and children's self-esteem. The results demonstrate that parents' childbearing intentions can have a significant long-term impact on their children's self-esteem. Children who were unintended by their mothers have significantly lower self-esteem 23 years later. Our findings indicate that giving birth to an unintended child can have a long-term negative impact on subjective aspects of the child's well-being, at least in terms of self-esteem. Unintended childbearing has received an increasing amount of research attention in recent years.
Revisiting occupational sex segregation in the United States, 1910–1990: Results from a log-linear approach
Authors: Weeden Kim A.
Published: March 2007

I reexamine trends in the strength and structure of occupational sex segregation in the United States from 1910 to 1990. Log-multiplicative models show significant change in the association between gender and occupation. Contrary to conventional characterizations, a substantial proportion of this change occurred before 1970. Likewise, a margin-free index shows more integration over the century than do conventional indices. These discrepancies arise from occupation-specific variations in the trajectory of sex segregation: Highly segregated occupations were especially likely to integrate between 1930 and 1940. I identify regions of the occupational structure and pivotal periods in which shifts in segregation occurred and compare these results with conventional historical accounts.
Occupational gender segregation: Index measureiient and econometric modeling
Authors: Watts Martin
Published: March 2007

Empirical studies of gender segregation by occupation must be founded on rigorous measurement procedures. There appears to be a consensus that any index used in the analysis of time-series or international cross-section employment data must be either margin-free or decomposable to yield a margin-free component. On the other hand, Charles and Grusky (1995) advocate the use of multiplicative log models from which a margin-free odds ratio can be derived. In this paper, I contrast the construction and interpretation of the index of dissimilarity and the Karmel-MacLachlan index with the multiplicative modeling of gender segregation and the associated log index.
Comment on “compromised birth outcomes and infant mortality among racial and ethnic groups”
Authors: Van Der Veen Willem Jan
Published: March 2007

Frisbie, Forbes, and Pullum (1996) show that it is meaningful to account for low birth weight, preterm delivery, and intrauterine growth-retardation when analyzing differences in compromised birth outcomes and infant mortality among racial and ethnic groups. I compare their findings for the 1987 U.S. birth cohort with findings for the 1988 U.S. birth cohort, using linked birth and infant death vital statistics from the National Center for Health Statistics. I focus on their calculation of fetal growth curves, which are highly at odds with the curves commonly used in the obstetric and pediatric literature. I compare birth outcome distributions and infant death probabilities using Frisbie et al. 's method and other standards. I conclude that Frisbie et al. 's method is not suited for the study of intrauterine growth-retardation at the population level because of the major flaws in gestational age measurement that exist in the type of data they use. An appropriate alternative is to apply a standard of normal intrauterine growth derived from antenatal estimation of fetal weight-for-gestational-age to the vital statistics data.
The ecology of race and socioeconomic distress: Infant and working-age mortality in Chicago
Authors: Guest Avery M. , Almgren Gunnar , Hussey Jon M.
Published: March 2007

We examine the effects of education, unemployment, and racial segregation on age-, sex-, and race-specific mortality rates in racially defined Chicago community areas from 1989 to 1991. Community socioeconomic factors account for large observed areal variations in infant and working-age mortality, but especially working-age mortality for the black population. For black men, the mortality consequences of living in economically distressed communities are quite severe. Segregation effects on mortality are more modest and largely operate through neighborhood socioeconomic conditions, although some direct effects of segregation on mortality for blacks are apparent.
Population growth and air quality in California
Authors: Cramer James C.
Published: March 2007

Demographers are often interested in the environmental impacts of population growth. I examine the impact of growth specifically on air quality in California. In recent decades, California has suffered from notoriously polluted air and has experienced rapid population growth. Despite the population .growth, air quality actually has improved since the early 1980s due to aggressive regulatory efforts. Using data for 56 counties, I analyze the contribution of population growth to trends in atmospheric emissions of five regulated pollutants from 1980 to 1990, controlling for trends in per capita income and regulatory efforts. The analysis is disaggregated by source of emissions and demonstrates that population growth is strongly associated with some sources of emissions but not with others. Thus, the overall impact of population growth depends upon the composition of production and consumption activities in each county. I also explore whether the trend in number of households predicts better than the trend in number of persons, and whether the impact of population growth depends upon the age structure or source of growth (immigration or domestic increase). Generally, these alternative specifications of population do not improve the models of atmospheric emissions.
Maternal education and child health: Is there a strong causal relationship?
Authors: Desai Sonalde , Alva Soumya
Published: March 2007

Using data from the first round of Demographic and Health Surveys for 22 developing countries, we examine the effect of maternal education on three markers of child health: infant mortality, children s height-for-age, and immunization status. In contrast to other studies, we argue that although there is a strong correlation between maternal education and markers of child health, a causal relationship is far from established. Education acts as a proxy for the socioeconomic status of the family and geographic area of residence. Introducing controls for husband’s education and access to piped water and toilet attenuate the impact of maternal education on infant mortality and children’s height-for-age. This effect is further reduced by controlling for area of residence through the use of fixed-effects models. In the final model. maternal education has a statistically significant impact on infant mortality and height-forage in only a handful of countries. In contrast. maternal education remains statistically significant for chidren’s immunization status in about one-half of the countries even after individual-level and community-level controls are introduced.
A dynamic analysis of turnover in employment and child care
Authors: Blau David M. , Robins PhiliP K.
Published: March 2007

The causes of turnover in child-care arrangements and maternal employment are analyzed using panel data from the National Longitudinal Survey of Youth, supplemented with state-level information on child-care markets. The results indicate that turnover in child care is quite high and that child and family characteristics help explain turnover. Important factors include the mother’s wage, the cost of child care, age of the child, and previous child-care decisions. The reduced-form nature of the analysis makes it difficult to determine whether these factors are important because they are associated with unstable child-care supply or because they affect family decisions, conditional on supply factors. The results provide no direct evidence that child-care turnover is higher in states with more unstable child-care markets.
Changes in assortative mating: The impact of age and education, 1970–1890
Authors: Qian Zhenchao
Published: March 2007

Data from the U.S. Census and Current Population Survey are used to examine trends in the propensity to marry or to cohabit by the age and educational attainment of potential partners. Marriage rates declined sharply across all age and educational combinations between 1970 and 1980 and declined more sharply for less-educated persons between 1980 and 1990. The rise in cohabitation compensated somewhat for the decline in marriage rates, but the compensation was unequally spread among age and educational combinations. Highly educated men were more likely, and highly educated women were no more or less likely, to marry than to cohabit with less-educated partners in 1970 and 1980. By 1990, however, educational assortative-mating patterns between these two types of unions were similar. In 1990, marriages and cohabitations involving women who were better educated than their partners were more common than those involving women who were less educated than their partners. In addition, men and women in their early 20s tend to have partners better educated than themselves, but persons in their 30s tend to cross the less-than-high-school/ more-than-high-school educational barrier when partners differ in educational attainment.
Family and sociodemographic influences on patterns of leaving home in Postwar Britain
Authors: Murphy Mike , Wang Duolao
Published: March 2007

We identify child-level and parent-level characteristics associated with children’s patterns of leaving home. We use a multilevel discrete-time hazards model to examine the impact of family and demographic factors at both levels, and utilize the Alternating Conditional Expectation algorithm optimally to transform the dependent and independent variables. We find that measured variables at both the child and the parent level have important influences, as do period and cohort factors. However, unmeasured parent-level factors have an influence on the departure of children that is broadly similar in magnitude to measured factors.
Couple childbearing plans and births in Sweden
Authors: Thomson Elizabeth , Hoem Jan M.
Published: March 2007

We use data from a nationally representative sample of Swedish couples to estimate effects of partners’ childbearing plans on the rate of subsequent childbearing. Only 11% of the couples in this sample expressed plans in opposite directions (plan to have a child versus not to have a child), but 24% had differing levels of certainty about their plans. Of the couples in which both partners said they definitely planned to have another child, 44% had a child within two years. If neither partner planned to have another child, less than 2% of couples had a birth. The figure was 6% if the partners had opposing childbearing plans. Thus, both men and women exerted veto power over further childbearing. Disagreements were equally likely to be resolved in favor of the woman as of the man, and effects of partners’ plans on the birth hazard did not depend on the couple’s gender arrangements, family ideologies, or marital status. We discuss these results in the context of Sweden’s public support for gender equality and for childrearing, its pervasive contraceptive regime, and its high rates of cohabitation. We also argue for the collection of data from partners in future family and fertility surveys.
Who gets custody?
Authors: Cancian Maria , Meyer Daniel R.
Published: March 2007

Changes in the living arrangements of children have implications for social policy and children’s well-being. Understanding who gets custody on divorce—mother, father, or both sharing custody—can also inform our understanding of family organization and the merits of alternative theories of marriage and divorce. We examine physical-custody outcomes among recent Wisconsin divorces in an effort to understand the factors associated with shared custody as well as mother-sole custody and father-sole custody. Although mother-sole custody remains the dominant arrangement, shared custody has increased over a nine-year period. We find that the probability of shared custody increases with parent’s income. Prior marital history. parents’ ages, the age and gender of children, and the legal process also have an impact on the probability of shared custody. In contrast to shared custody, the probability of father-sole custody decreases with parent’s income, while the relationship with other significant factors is generally similar. The notable exception is that, unlike shared custody, we find no evidence for an increase over time in the probability of father-sole custody. We also find that when the father has a higher proportion of the Couple’s total income, both shared custody and father-sole custody are more likely.
The impact of child support on cognitive outcomes of young children
Authors: Argys Laura M. , Peters H. Elizabeth , Brooks-Gunn Jeanne , Smith Judith R.
Published: March 2007

We use the National Longitudinal Survey of Youth-Child data to address three questions. First, does the receipt of child support have beneficial effects for children with absent fathers apart from increasing income? Second, do the effects of child support differ when child-support awards and payments are made cooperatively as opposed to being court ordered? Third, are any positive effects of child support solely a product of unmeasured differences among fathers and families? Controlling for the socioeconomic characteristics of the child and family, we find some evidence that receipt of child support has a positive impact on children’s cognitive test scores over and above its contribution to total income. However, the effects vary by test, by race, and by reason for Father’s absence. Our results also indicate that the distinction between cooperative and noncooperative awards is important. Finally, our instrumental variables estimates show that the effects of child support persist after we control for unobserved characteristics of fathers and families.
Parenting from a distance: The effects of paternal characteristics on contact between nonresidential fathers and their children
Authors: Cooksey Elizabeth C. , Craig Patricia H.
Published: March 2007

Changes in marital and fertility behavior have influenced the role of father for many men. We use data from the first two waves of the National Survey of Families and Households to examine various sociodemographic, situational, and attitudinal characteristics that might influence the degree of contact between nonresidential fathers and their minor children. We tap two different dimensions of distance parenting and find that although several variables influence both visiting and talking on the telephone or writing letters, some factors (the presence of multiple children in a household) predict visiting only, while others (child’s age and gender) predict only verbal/written contact. Similarly, some of the life-course decisions made by fathers appear to crowd out their involvement with nonresidential children, whereas other decisions reinforce their parenting behavior.
Paternal involvement with adolescents in intact families: The influence of fathers over the life course
Authors: Harris Kathleen Mullan , Furstenberg Frank F. , Marmer Jeremy K.
Published: March 2007

We measure the quality and quantity of fathers’ involvement with adolescent children in intact families over time using longitudinal data from The National Survey of Children. We examine differentials in fathers’ involvement by children’s and family characteristics and model the long-term effects of fathers’ involvement on children’s outcomes in the transition to adulthood. Fathers are more involved with sons than with daughters and they disengage from adolescents with increasing marital conflict. We find beneficial effects for children of father’s involvement in three domains: educational and economic attainment, delinquent behavior, and psychological well-being. The course of affective relations throughout adolescence also has a beneficial effect on delinquent behavior and psychological well-being.
Fathers and absent fathers: Sociodemographic similarities in britain and the United States
Authors: Clarke Lynda , Cooksey Elizabeth C. , Verropoulou Georgia
Published: March 2007

Using data from the British Household Panel Survey and the National Survey of Families and Households in the United States, we present a sociodemographic profile of fathers and compare the determinants of absent fatherhood in each country. Although fatherhood has a younger profile in the United States, especially for blacks, predictors of fathers’ residency with their children are remarkably similar in the two countries. In both countries, the strongest predictor of a father’s absence is the parents’ relationship to each other at the time of the child’s birth. Policy implications of this finding are discussed.
Cohabiting partners’ economic circumstances and marriage
Authors: Smock Pamela J. , Manning Wendy D.
Published: March 2007

Past studies of the transition to marriage generally have relied on information about only one individual or have attempted to measure characteristics of potential spouses indirectly. Drawing on data from the two waves of the National Survey of Families and Households (NSFH), we examine the effects of economic circumstances of both partners in cohabiting unions on the transition to marriage. Focusing on both partners in a relationship affords a more direct test of the relative importance of men’s versus women s economic circumstances. Our findings suggest that only the male partner’s economic resources affect the transition to marriage, with positive economic situations accelerating marriage and deterring separation. Our results imply that despite trends toward egalitarian gender-role attitudes and increasing income provision among women, cohabiting men s economic circumstances carry far more weight than women’s in marriage formation.
Polygyny and reproductive behavior in sub-saharan Africa: A contextual analysis
Authors: Ezeh Alex Chika
Published: March 2007

In this paper I examine the effect of polygyny on aggregate reproductive behavior. I argue that within countries there exist different polygyny regimes, each exhibiting a unique reproductive pattern. Using the 1988/1989 Kenya Demographic and Health Survey (KDHS1) data, I identify three distinct regimes: low-polygyny, mid polygyny, and high-polygyny regimes. The results of the bivariate and multivariate analyses reveal strong differences in reproductive preferences and behaviors across polygyny regimes. High-polygyny regimes, for instance, maintain a value orientation that favors and encourages high reproductive performance. The force of this pronatalism operates equally for men and women; but whereas men in this regime attain their reproductive goals by marrying multiple wives, women attain theirs by maximizing their reproductive capabilities. This maximization occurs through early initiation of sexual/reproductive activity, universal marriage and minimal interruption of marriage, nonuse of contraception within a union, and a positive attitude toward high fertility.
Estimating childhood mortality trends from routine data: A simulation using the preceding birth technique in Bangladesh
Authors: Bairagi Radheshyam , Shuaib Muhammad , Hill Allan G.
Published: March 2007

The Preceding Birth Technique (PBT) has been proposed as a method suitable for ascertaining the prevailing level of under-2 mortality in countries without full vital registration. It is a monitoring tool rather than a method that will replace other established approaches to measuring childhood mortality levels and differentials that other demographers have developed over the last 30 years. The principle obstacle to the wider adoption of the PBT is the low proportion of women who give birth in maternity clinics and hospitals. A larger proportion of mothers, however, visit clinics and hospitals for antenatal care and to vaccinate their newborn. We used data from the Matlab surveillance system to test the accuracy of mortality estimates derived using the PBT with data obtained from mothers at antenatal visits and at the vaccination of their youngest children. The study shows that the PBT estimates under-3 rather than under-2 mortality in Bangladesh due to the long birth intervals. The data, when used to simulate the collection of the information at antenatal or postnatal visits, nonetheless provide an accurate description of under-3 mortality trends and differences for the two periods examined—before 1984 and before 1989.
Urban labor markets and individual transitions out of poverty
Authors: Iceland John
Published: March 2007

Using data from the Panel Study of Income Dynamics and the U.S. census, I examine the effect of four structural characteristics on individual poverty exits: (1) economic restructuring, (2) skills mismatches, (3) racial residential segregation, and (4) welfare benefit levels. Results show that these factors play a role in explaining African Americans’ economic disadvantages, but they have a weaker and often contrary impact on whites’ poverty exits. Overall, the differing impact of the contextual characteristics on African Americans and whites exacerbates social stratification and illustrates racial divisions that continue to pervade the labor market.
Migration, fertility, and state policy in Hubei Province, China
Authors: Goldstein Alice , White Michael , Goldstein Sidney
Published: March 2007

Despite China s one-child family planning policy, the nation experienced a slight rise in the birth rate in the mid-1980s. Many observers attributed this rise to the heightened fertility of those rural-to-urban migrants who moved without a change in registration (temporary migrants), presumably to avoid the surveillance of family planning programs at origin and destination. Using a sequential logit analysis with life-history data from a 1988 survey of Hubei Province, we test this possibility by comparing nonmigrants, permanent migrants, and temporary migrants. While changing family planning policies have a strong impact on timing of first birth and on the likelihood of higher-order births, migrants generally do not have more children than nonmigrants. In fact, migration tends to lower the propensity to have a child. More specifically, the fertility of temporary migrants does not differ significantly from that of other women.
An occupational tale of two cities: Minorities in London and New York
Authors: Model Suzanne
Published: March 2007

In this paper, queuing theory is tested through an examination of the occupational attainment of six groups of non-whites in London and New York. Workers in the dominant economy are distinguished from those in the niche economy and emphasis is placed on the former. Black male immigrants in New York and black female immigrants in London hold more favorable occupational status. These results reflect differences in (1) the presence of indigenous minorities—African Americans and Puerto Ricans—in New York but not London, and (2) the relatively low position of indigenous minority males compared to the relatively middling position of indigenous minority females in New York:S labor queue.
Age-distribution dynamics and aging indexes
Authors: Chu C. Y. Cyrus
Published: March 2007

I analyze the dynamics of the age distribution as some vital rates change. When the fertility or mortality rate declines, the age distribution often manifests a dynamic stochastic-dominance relationship. I also propose some alternative indexes for measuring population aging. These indexes are closely connected with the age-distribution dynamics and contain more refined information about the distribution of age among the old.
Artificial Intelligence–Generated Draft Replies to Patient Inbox Messages
Authors: Garcia Patricia , Ma Stephen P. , Shah Shreya , Smith Margaret , Jeong Yejin , Devon-Sand Anna , Tai-Seale Ming , Takazawa Kevin , Clutter Danyelle , Vogt Kyle , Lugtu Carlene , Rojo Matthew , Lin Steven , Shanafelt Tait , Pfeffer Michael A. , Sharp Christopher
Published: March 2024

Importance

The emergence and promise of generative artificial intelligence (AI) represent a turning point for health care. Rigorous evaluation of generative AI deployment in clinical practice is needed to inform strategic decision-making.

Objective

To evaluate the implementation of a large language model used to draft responses to patient messages in the electronic inbox.

Design, Setting, and Participants

A 5-week, prospective, single-group quality improvement study was conducted from July 10 through August 13, 2023, at a single academic medical center (Stanford Health Care). All attending physicians, advanced practice practitioners, clinic nurses, and clinical pharmacists from the Divisions of Primary Care and Gastroenterology and Hepatology were enrolled in the pilot.

Intervention

Draft replies to patient portal messages generated by a Health Insurance Portability and Accountability Act–compliant electronic health record–integrated large language model.

Main Outcomes and Measures

The primary outcome was AI-generated draft reply utilization as a percentage of total patient message replies. Secondary outcomes included changes in time measures and clinician experience as assessed by survey.

Results

A total of 197 clinicians were enrolled in the pilot; 35 clinicians who were prepilot beta users, out of office, or not tied to a specific ambulatory clinic were excluded, leaving 162 clinicians included in the analysis. The survey analysis cohort consisted of 73 participants (45.1%) who completed both the presurvey and postsurvey. In gastroenterology and hepatology, there were 58 physicians and APPs and 10 nurses. In primary care, there were 83 physicians and APPs, 4 nurses, and 8 clinical pharmacists. The mean AI-generated draft response utilization rate across clinicians was 20%. There was no change in reply action time, write time, or read time between the prepilot and pilot periods. There were statistically significant reductions in the 4-item physician task load score derivative (mean [SD], 61.31 [17.23] presurvey vs 47.26 [17.11] postsurvey; paired difference, −13.87; 95% CI, −17.38 to −9.50; P < .001) and work exhaustion scores (mean [SD], 1.95 [0.79] presurvey vs 1.62 [0.68] postsurvey; paired difference, −0.33; 95% CI, −0.50 to −0.17; P < .001).

Conclusions and Relevance

In this quality improvement study of an early implementation of generative AI, there was notable adoption, usability, and improvement in assessments of burden and burnout. There was no improvement in time. Further code-to-bedside testing is needed to guide future development and organizational strategy.
Effect of the Heating/Cooling Rate of Nonisothermal Aging on Microstructure and Mechanical Properties of 2050 Al–Li Alloy
Authors: Xu Guofu , Tang Yuan , Li Yao , Yi Zhihao , Li Haoran , Li Jinfeng , Tang Lei
Published: March 2024

The effect of the heating/cooling rates of nonisothermal aging (NIA) on microstructure and mechanical properties of 2050 Al–Li alloy are investigated. The 2050 Al–Li alloy is first solid solutioned and predeformed and then heated from 130 to 220 °C at different rates of 20, 30 °C h−1, or 40 °C h−1 and then cooled to 150 °C. The results show that the mechanical properties of the alloy subjected to NIA treatment can be improved by adjusting the heating and cooling rate. When the heating and cooling rate is 30 °C h−1, the alloy achieves the best mechanical properties; the hardness, ultimate tensile strength (UTS), yield strength (YS), and elongation are 182.9 HV, 597, 571 MPa, and 9.6%, respectively. With the decrease of heating (or cooling) rate of NIA, the diameter and thickness of the T1 precipitate increase and the volume fraction decreases, resulting in the variation in mechanical properties. Therefore, herein, premier precipitation behavior and improved mechanical properties are both achieved by modifying the heating and cooling rate of NIA; the effect of the heating/cooling rate of NIA on the microstructure evolution of 2050 Al–Li alloy is revealed, and the underlying strengthening mechanism is investigated in detail.
Thermopneumatic Liquid Metal Radiofrequency Switch Actuated by Low‐Boiling‐Point Fluid
Authors: Li Chunwei , Qiao Mengwen , Zhang Huimin , Zhou Yixin , Liu Jing , Wang Lei , Deng Zhongshan
Published: March 2024

Existing radiofrequency (RF) switches used in reconfigurable antennas often encounter performance issues such as high insertion loss, low isolation, and nonlinear effects of the switch. To address these issues, this article presents a liquid metal RF switch that utilizes a heated low‐boiling‐point fluid (LBPF) to drive the movement of a eutectic gallium‐indium alloy (EGaIn) plunger to turn the switch on/off. The operating principle of the switch is to use the pressure difference generated by the liquid–vapor phase change of the LBPF to make the EGaIn plunger to contact with, or disconnect from the copper electrodes of the switch. The performances of the RF switches actuated by different LBPFs are respectively investigated, and the results show that all RF switches have millisecond response times, and the contact resistances are as low as 0.14 mΩ. In addition, good RF performances are achieved, with an insertion loss of less than 3 dB and isolation of more than 17 dB in the frequency band from 0 to 2 GHz, and no nonlinear effects. This study also validates the performance of the proposed switch for frequency reconfiguration of a folded monopole antenna.
Nanocarbon/Co3O4/Epoxy Composites for Microwave Shielding and Absorption
Authors: Vovchenko Ludmila , Matzui Ludmila , Zagorodnii Volodymyr , Oliynyk Victor , Borovoy Mykola
Published: March 2024

The epoxy composite materials (CMs) with a random distribution of nanosized Co3O4 and carbon nanoparticles (graphite nanoplatelets GNP and carbon nanotubes CNT) are fabricated. Complex permittivity, permeability, and shielding properties of composite materials with 30 wt% of Co3O4 and (2–5) wt% of nanocarbon are measured in the frequency range of 1–67 GHz using the transmission–reflection method. A significant increase of microwave permittivity and presence of several peaks on the dependencies of the imaginary part of permittivity on the frequency are found for three‐phase nanocarbon/Co3O4/epoxy CMs. The observed microwave shielding efficiency of three‐phase epoxy composites is enhanced compared to two‐phase nanocarbon–epoxy composites. Such enhancement of shielding efficiency correlates with the increase of DC conductivity of these three‐phase composites. The measured complex permittivity and permeability spectra for nanocarbon/Co3O4/epoxy CMs are used for modeling the reflection loss for studied composites. It is shown that the most preferable for microwave absorption is the composites containing 2 wt% of nanocarbon filler for a sample thickness of 0.5–0.7 mm. The highest reflection loss  = 30 dB with an absorption bandwidth of 15 GHz is found for epoxy composite filled with 2 wt% of GNP and 30 wt% of Co3O4 for a sample thickness of 0.5 mm.
Biomimetic Platelet‐Cloaked Nanoparticles for the Delivery of Anti‐Inflammatory Curcumin in the Treatment of Atherosclerosis
Authors: Fontana Flavia , Molinaro Giuseppina , Moroni Sofia , Pallozzi Giulia , Ferreira Mónica P. A. , Tello Rubén Pareja , Elbadri Khalil , Torrieri Giulia , Correia Alexandra , Kemell Marianna , Casettari Luca , Celia Christian , Santos Hélder A.
Published: March 2024

Atherosclerosis still represents a major driver of cardiovascular diseases worldwide. Together with accumulation of lipids in the plaque, inflammation is recognized as one of the key players in the formation and development of atherosclerotic plaque. Systemic anti‐inflammatory treatments are successful in reducing the disease burden, but are correlated with severe side effects, underlining the need for targeted formulations. In this work, curcumin is chosen as the anti‐inflammatory payload model and further loaded in lignin‐based nanoparticles (NPs). The NPs are then coated with a tannic acid (TA)− Fe (III) complex and further cloaked with fragments derived from platelet cell membrane, yielding NPs with homogenous size. The two coatings increase the interaction between the NPs and cells, both endothelial and macrophages, in steady state or inflamed status. Furthermore, NPs are cytocompatible toward endothelial, smooth muscle and immune cells, while not inducing immune activation. The anti‐inflammatory efficacy is demonstrated in endothelial cells by real‐time quantitative polymerase chain reaction and ELISA assay where curcumin‐loaded NPs decrease the expression of Nf‐κb, TGF‐β1, IL‐6, and IL‐1β in lipopolysaccharide‐inflamed cells. Overall, due to the increase in the cell−NP interactions and the anti‐inflammatory efficacy, these NPs represent potential candidates for the targeted anti‐inflammatory treatment of atherosclerosis.
A Power‐Managed Tribovoltaic Nanogenerator and Self‐Powered Wireless Temperature Monitoring System
Authors: Cao Jie , Dong Zefang , Zhang Zhi , Gong Likun , Gao Yikui , Dai Yiming , Liu Guoxu , Feng Yuan , Jin Zhelin , Luan Ruifei , Wang Zhaozheng , Dong Sicheng , Cheng Guanggui , Zhang Chi , Ding Jianning
Published: March 2024

The emerging tribovoltaic nanogenerators (TVNGs) has garnered considerable attention in recent years owing to its higher power density, but it is still limited by unstable output, mismatched impedance, and lower charging speed. Herein, a power‐managed GaN‐based TVNG is first proposed and a self‐powered wireless temperature monitoring system (SWTMS) is developed. The energy backflow from transition capacitor to TVNG is effectively suppressed by applying a high‐voltage‐resistant diode. Benefiting from the combination of the maximum power point tracking (MPPT and the buck converter, an autonomous power management unit (PMU) is designed. The internal impedance of TVNG with PMU decreases by ten times and the charging speed of capacitor increases by 7.18 times compared to those without PMU. Moreover, 100 LEDs and six parallel thermohygrometers can be constantly powered. The wireless temperature monitoring in industrial environments without external power supply is demonstrated through the developed SWTMS. This work proposes an effective power management strategy for TVNG with high output voltage, which exhibits great potential to promote the development of self‐powered sensors and Industrial Internet of Things (IIoT).
United States crop conditions: 1986–2022
Authors: Bundy Logan R. , Gensini Vittorio A. , Ashley Walker S. , Haberlie Alex M. , Changnon David
Published: March 2024

USDA National Agricultural Statistics Service general crop condition data are used to quantify the relationship between crop conditions and yield, condition tendencies during the growing season, how conditions vary across the United States, and how conditions have trended for the 1986–2022 period for a variety of crops: barley (Hordeum vulgare L.), corn (Zea mays L.), cotton (Gossypium hirsutum L.), oats (Avena sativa L.), peanuts (Arachis hypogaea L.), rice (Oryza sativa L.), sorghum (Sorghum bicolor L.), soybeans (Glycine max L.), and spring and winter wheat (Triticum aestivum L.). Crop conditions are a statistically significant covariate (90% significance level) for yield and can be used in practice on a weekly basis. This becomes increasingly important as, historically, crop conditions not only deteriorated on average, but also became more variable throughout the growing season. Spatial differences in conditions, variability, and trends in condition ratings and variability are caused by crop selection, regional climate, and management practices such as irrigation. Crop conditions were poorest and had the highest interannual variability across the southern Great Plains region. Since 1986, crop conditions in the Great Plains region have deteriorated significantly, while variability has increased. Meanwhile, crop conditions across the southwestern and southeastern United States have significantly improved, while interannual variability in conditions has experienced robust declines. Given climatic and hydrologic trends, to maintain a positive trend in yield, continued advancements in production management and technology are required. Critical decisions regarding real‐time or future management can be supplemented by using crop condition risk assessment information along with actively monitoring weekly conditions.
Messagenin–based Chalcones: Synthesis, Modification and Perspectives of Antidiabetic Potency
Authors: Galimova Zarema , Khusnutdinova Elmira , Smirnova Irina , Poptsov Alexander , Spirikhin Leonid , Gabdrakhmanova Svetlana , Makara Nina , Nguyen Thi Thu Ha , Thi Tu Anh Le , Thanh Tra Nguyen , Thi Cham Ba , Kazakova Oxana
Published: March 2024

A series of messagenin–based chalcones has been synthesized by Claisen‐Schmidt condensation and screened for in vitro α‐glucosidase inhibitory activity. The heterocyclization of 30‐(3‐pyridinylidene)‐messagenin led to syn/anti N‐acetyl‐pyrazoles in a ratio of 2 : 1 that were isolated by HPLC. Messagenin chalcones act as α‐glucosidase inhibitors with IC50 range from 0.055 to 80.70 μM. The lead nanomolar level α‐glucosidase inhibitor 30‐(4‐hydroxymethyl‐benzylidene)‐messagenin 10 was studied for antihyperglycemic activity on streptozotocin–induced diabetic animal models using in vivo mechanism–based assays. In a rat model of STZ‐induced T1DM, compound 10 (20 mg/kg, orally) exhibited antihyperlipidemic activity, reducing AIP (p>0.05) and CRI (p<0.05) compared to control. Compound 10 improved diabetic nephropathy, locomotor activity in rats, and reduced diabetes–related mortality.