Abstract
One aspect of earthquake physics not adequately addressed is why some earthquakes generate thousands of aftershocks while other earthquakes generate few, if any, aftershocks. It also remains ...unknown why aftershock rates decay as ~1/time. Here, I show that these two are linked, with a dearth of aftershocks reflecting the absence of high-pressure fluid sources at depth, while rich and long-lasting aftershock sequences reflect tapping high-pressure fluid reservoirs that drive aftershock sequences. Using a physical model that captures the dominant aspects of permeability dynamics in the crust, I show that the model generates superior fits to observations than widely used empirical fits such as the Omori-Utsu Law, and find a functional relationship between aftershock decay rates and the tectonic ability to heal the co- and post-seismically generated fracture networks. These results have far-reaching implications, and can help interpret other observations such as seismic velocity recovery, attenuation, and migration.
The field of sustainable polymers is growing and evolving at unprecedented rates. Researchers are increasingly concerned with the feedstock origins and the degradation behavior of, especially, ...large-scale commodity packaging plastics. A perspective is offered here for the design of sustainable polymers, specifically addressing opportunities for monomer development and polymer degradation. Key concepts include: water degradability instead of biodegradability; incorporation of novel main-chain functionality, such as acetals; utilization of lignin-based aromatics; and direct polymerization of biogenic C1 feedstocks.
Cognitive interventions may improve cognition, delay age-related cognitive declines, and improve quality of life for older adults. The current meta-analysis was conducted to update and expand ...previous work on the efficacy of cognitive interventions for older adults and to examine the impact of key demographic and methodological variables. EBSCOhost and Embase online databases and reference lists were searched to identify relevant randomized-controlled trials (RCTs) of cognitive interventions for cognitively healthy or mildly impaired (MCI) older adults (60+ years). Interventions trained a single cognitive domain (e.g., memory) or were multi-domain training, and outcomes were assessed immediately post-intervention using standard neuropsychological tests. In total, 279 effects from 97 studies were pooled based on a random-effects model and expressed as Hedges’
g
(unbiased). Overall, results indicated that cognitive interventions produce a small, but significant, improvement in the cognitive functioning of older adults, relative to active and passive control groups (
g
= 0.298,
p
< .001, 95% CI = 0.248–0.347). These results were confirmed using multi-level analyses adjusting for nesting of effect sizes within studies (
g =
0.362,
p
< .001, 95% CI = 0.275, 0.449). Age, education, and cognitive status (healthy vs. MCI) were not significant moderators. Working memory interventions proved most effective (
g
= 0.479), though memory, processing speed, and multi-domain interventions also significantly improved cognition. Effects were larger for directly trained outcomes but were also significant for non-trained outcomes (i.e., “transfer effects”). Implications for future research and clinical practice are discussed. This project was pre-registered with PROSPERO (#42016038386).
Building on Viazovska's recent solution of the sphere packing problem in eight dimensions, we prove that the Leech lattice is the densest packing of congruent spheres in twenty-four dimensions and ...that it is the unique optimal periodic packing. In particular, we find an optimal auxiliary function for the linear programming bounds, which is an analogue of Viazovska's function for the eight-dimensional case.
This study examined the relationship between Executive Function (EF) and Theory of Mind (ToM) using the Delis-Kaplan Executive Function System (D-KEFS) and three tests of ToM (Reading the Mind in the ...Eyes test (RMET), Strange Stories test, and Faux Pas test). Separate regression analyses were conducted, and EF predictors varied by ToM test. No EF domains accounted for significant variance in RMET scores; only estimated IQ scores were significant predictors of RMET performance. Verbal fluency and deductive reasoning were significant predictors of performance on the Strange Stories test, while verbal fluency, problem solving, and gender accounted for a significant variance in the Faux Pas test. Results suggest that the ToM tests each utilized differing cognitive mechanisms.
Summary
Observations noting the presence of white blood cell infiltrates within tumors date back more than a century, however the cellular and molecular mechanisms regulating tumor immunity continue ...to be elucidated. The recent successful use of monoclonal antibodies to block immune regulatory pathways to enhance tumor‐specific immune responses for the treatment of cancer has encouraged the identification of additional immune regulatory receptor/ligand pathways. Over the past several years, a growing body of data has identified B7‐H4 (VTCN1/B7x/B7S1) as a potential therapeutic target for the treatment of cancer. The potential clinical significance of B7‐H4 is supported by the high levels of B7‐H4 expression found in numerous tumor tissues and correlation of the level of expression on tumor cells with adverse clinical and pathologic features, including tumor aggressiveness. The biological activity of B7‐H4 has been associated with decreased inflammatory CD4+ T‐cell responses and a correlation between B7‐H4‐expressing tumor‐associated macrophages and FoxP3+ regulatory T cells (Tregs) within the tumor microenvironment. Since B7‐H4 is expressed on tumor cells and tumor‐associated macrophages in various cancer types, therapeutic blockade of B7‐H4 could favorably alter the tumor microenvironment allowing for antigen‐specific clearance tumor cells. The present review highlights the therapeutic potential of targeting B7‐H4.
According to Alexis de Tocqueville's influential work on the Old
Regime and the French Revolution, royal centralisation had so
weakened the feudal power of the nobles that their remaining
privileges ...became glaringly intolerable to commoners . This
book challenges the theory by showing that when Louis XVI convened
assemblies of landowners in the late 1770s and 1780s to discuss
policies needed to resolve the budgetary crisis, he faced
widespread opposition from lords and office holders. These elites
regarded the assemblies as a challenge to their hereditary power
over commoners. The king's government comprised seigneurial
jurisdictions and venal offices. Lordships and offices upheld
inequality on behalf of the nobility and bred the discontent
motivating the people to make the French Revolution.
Effective next-generation leadership is central to the multi-generational survival of family businesses. This study of 100 next-generation family business leaders found that business-owning families ...that openly express their opinions, take time to listen to each other, and squarely address difficult issues positively influence the development of the emotional and social intelligence competencies in next-generation family leaders that drive their leadership effectiveness. That kind of open and transparent communication in the family also makes it more likely next-generation leaders will be held accountable for their leadership performance by others, which increases the degree to which they are positively engaged with their work in the family firm. On the other hand, the results suggest that senior-generation family leaders who lead autocratically, a leadership style often observed in entrepreneurs who found family firms, make it less likely that next-generation family leaders will learn the emotional and social intelligence competencies that predict their leadership effectiveness. The study also found that autocratic senior-generation leaders negatively affect next-generation leader self-efficacy and make it less likely that others will hold them accountable, which limits their engagement with work in the family business. One of the study's most important findings is that next-generation leader acceptance of personal responsibility for their leadership behaviors and results serves as a mediator through which the nature of the family climate influences their leadership effectiveness and work engagement. This suggests that while the nature of family relationships may make it easier or more difficult, next-generation family leaders have ultimate control over the development of their leadership talent and the inspiration, enthusiasm, energy, and pride they feel when working in the family business.
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