COHABITATION: AN ELUSIVE CONCEPT

Rates of out-of-wedlock births in the US have increased over the past three decades and rates of cohabitation among unwed parents have risen. Consequently, unwed parenthood is decreasingly synonymous with single parenthood. As we focus more attention on unwed parents, their living arrangements, and relationships, it is becoming clear that cohabitation is an ambiguous concept that is difficult to measure. In this study, we use the Fragile Families and Child Wellbeing data to document how sensitive cohabitation estimates can be to various sources of information and we demonstrate that relationships among unwed parents fall along a continuum, from marriage-like cohabitation at one extreme to parents who have no contact at all with one another at the other. The results underscore the limitations of using binary measures of cohabitation to characterize parent relationships.

Mental Illness as a Barrier to Marriage Among Mothers With Out-of-Wedlock Births

This study explores how mental illness shapes transitions to marriage among unwed mothers using augmented data from the Fragile Families and Child Wellbeing study. We estimate proportional hazard models to assess the effects of mental illness on the likelihood of marriage over a five year period following a non-marital birth. Diagnosed mental illness was obtained from the survey respondents' prenatal medical records. We find that mothers with mental illness were about two thirds as likely as mothers without mental illness to marry, even after controlling for demographic characteristics, and that human capital, relationship quality, partner selection, and substance abuse explain only a small proportion of the effect of mental illness on marriage.

NCEAS: Promoting Creative Collaborations

NCEAS -- an ecological synthesis center -- is changing the way ecological research is conducted by fostering new forms of collaboration and interdisciplinary researc

Effects of Welfare Participation on Marriage

Despite interest in the potential of the welfare system as a tool to affect marriage behaviors among low-income women, little is known about how welfare participation affects decisions to marry. We employ an event history approach to examine transitions to marriage over a five-year period among mothers who have had a non-marital birth. We find that welfare participation under the Temporary Assistance to Needy Families program (TANF) reduces the likelihood of transitioning to marriage (hazard ratio is .67, p

The Role of Welfare in New Parents’ Lives

Welfare caseloads have declined substantially since the landmark PRWORA legislation of 1996, which was designed to shift the burden of supporting needy families from government to families themselves. These caseload declines have been well documented, and characteristics of recipients following the implementation of PRWORA can be gleaned from administrative and agency records. Less readily available is documentation of recent rates of welfare dependency for specific population subgroups. Mothers giving birth in the aftermath of the 1996 legislation are of particular interest since they are more likely than other potential recipients to meet work requirements and hit time limits before their children are in school.

Avalanches and Dynamical Correlations in supercooled liquids

We identify the pattern of microscopic dynamical relaxation for a two dimensional glass forming liquid. On short timescales, bursts of irreversible particle motion, called cage jumps, aggregate into clusters. On larger time scales, clusters aggregate both spatially and temporally into avalanches. This propagation of mobility, or dynamic facilitation, takes place along the soft regions of the systems, which have been identified by computing isoconfigurational Debye-Waller maps. Our results characterize the way in which dynamical heterogeneity evolves in moderately supercooled liquids and reveal that it is astonishingly similar to the one found for dense glassy granular media.Comment: 4 pages, 3 figure

The Roots of Defense: Plant Resistance and Tolerance to Belowground Herbivory

There is conclusive evidence that there are fitness costs of plant defense and that herbivores can drive selection for defense. However, most work has focused on above-ground interactions, even though belowground herbivory may have greater impacts on individual plants than above-ground herbivory. Given the role of belowground plant structures in resource acquisition and storage, research on belowground herbivores has much to contribute to theories on the evolution of plant defense. Pocket gophers (Geomyidae) provide an excellent opportunity to study root herbivory. These subterranean rodents spend their entire lives belowground and specialize on consuming belowground plant parts. produced significantly more fruit than either damaged or undamaged mainland individuals.These results suggest that mainland plants are effective at deterring and tolerating pocket gopher herbivory. Results also suggest that both forms of defense are costly to fitness and thus reduced in the absence of the putative target herbivore

Glasslike Arrest in Spinodal Decomposition as a Route to Colloidal Gelation

Colloid-polymer mixtures can undergo spinodal decomposition into colloid-rich and colloid-poor regions. Gelation results when interconnected colloid-rich regions solidify. We show that this occurs when these regions undergo a glass transition, leading to dynamic arrest of the spinodal decomposition. The characteristic length scale of the gel decreases with increasing quench depth, and the nonergodicity parameter exhibits a pronounced dependence on scattering vector. Mode coupling theory gives a good description of the dynamics, provided we use the full static structure as input.Comment: 14 pages, 4 figures; replaced with published versio

Academic Freedom and Electronic Communications

In November 2004, the Association’s Council adopted Academic Freedom and Electronic Communications, a report prepared by a subcommittee of Committee A on Academic Freedom and Tenure and approved by Committee A. That report affirmed one “overriding principle”: Academic freedom, free inquiry, and freedom of expression within the academic community may be limited to no greater extent in electronic format than they are in print, save for the most unusual situation where the very nature of the medium itself might warrant unusual restrictions—and even then only to the extent that such differences demand exceptions or variations. Such obvious differences between old and new media as the vastly greater speed of digital communication, and the far wider audiences that electronic messages may reach, would not, for example, warrant any relaxation of the rigorous precepts of academic freedom. This fundamental principle still applies, but developments since publication of the 2004 report suggest that a fresh review of issues raised by the continuing growth and transformation of electronic-communications technologies and the evolution of law in this area is appropriate. For instance, the 2004 report focused largely on issues associated with e-mail communications and the posting of materials on websites, online bulletin boards, learning-management systems, blogs, and listservs. Since then, new social media, such as Facebook, LinkedIn, Reddit, Tumblr, and Twitter, have emerged as important vehicles for electronic communication in the academy