A replicated study on nuclear proliferation shows the critical necessity of reviewing accepted scientific results.

In replicating a 2009 study on the role of asymmetric nuclear weapons possession, Mark Bell and Nicholas Miller found that a computational error led to the overestimation of the deterrent effect of nuclear weapons by a factor of several million. It is only through constant re-evaluation of scholarly findings that scholars can reach sufficiently robust conclusions that merit the attention of policymakers

Caution, Drivers! Children Present: Traffic, Pollution, and Infant Health

Since the Clean Air Act Amendments of 1990 (CAAA), atmospheric concentration of local pollutants has fallen drastically. A natural question is whether further reductions will yield additional health benefits. We further this research by addressing two related research questions: (1) what is the impact of automobile driving (and especially congestion) on ambient air pollution levels, and (2) what is the impact of modern air pollution levels on infant health? Our setting is California (with a focus on the Central Valley and Southern California) in the years 2002-2007. Using an instrumental variables approach that exploits the relationship between traffic, ambient weather conditions, and various pollutants, our findings suggest that ambient pollution levels, specifically particulate matter, still have large impacts on weekly infant mortality rates. Our results also illustrate the importance of weather controls in measuring pollution’s impact on infant mortality.University of California Energy Institute and UC Davis Institute of Transportation Studies. UC Davis Institute of Governmental Affairs, the UC Davis Institute of Transportation Studies, and the TSR&TP through the Atmospheric Aerosols and Health (AAH) Lead Campus program

Coupled impacts of the diurnal cycle of sea surface temperature on the Madden–Julian oscillation

Author Posting. © American Meteorological Society, 2014. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Climate 27 (2014): 8422–8443, doi:10.1175/JCLI-D-14-00141.1.This study quantifies, from a systematic set of regional ocean–atmosphere coupled model simulations employing various coupling intervals, the effect of subdaily sea surface temperature (SST) variability on the onset and intensity of Madden–Julian oscillation (MJO) convection in the Indian Ocean. The primary effect of diurnal SST variation (dSST) is to raise time-mean SST and latent heat flux (LH) prior to deep convection. Diurnal SST variation also strengthens the diurnal moistening of the troposphere by collocating the diurnal peak in LH with those of SST. Both effects enhance the convection such that the total precipitation amount scales quasi-linearly with preconvection dSST and time-mean SST. A column-integrated moist static energy (MSE) budget analysis confirms the critical role of diurnal SST variability in the buildup of column MSE and the strength of MJO convection via stronger time-mean LH and diurnal moistening. Two complementary atmosphere-only simulations further elucidate the role of SST conditions in the predictive skill of MJO. The atmospheric model forced with the persistent initial SST, lacking enhanced preconvection warming and moistening, produces a weaker and delayed convection than the diurnally coupled run. The atmospheric model with prescribed daily-mean SST from the coupled run, while eliminating the delayed peak, continues to exhibit weaker convection due to the lack of strong moistening on a diurnal basis. The fact that time-evolving SST with a diurnal cycle strongly influences the onset and intensity of MJO convection is consistent with previous studies that identified an improved representation of diurnal SST as a potential source of MJO predictability.The authors gratefully acknowledge support from the Office of Naval Research (N00014-13-1-0133 and N00014-13-1-0139) and National Science Foundation EaSM-3 (OCE-1419235). HS especially thanks the Penzance Endowed Fund for their support of Assistant Scientists at WHOI.2015-05-1

Caution, Drivers! Children Present: Traffic, Pollution, and Infant Health

Since the Clean Air Act Amendments of 1990 (CAAA), atmospheric concentration of local pollutants has fallen drastically. A natural question is whether further reductions will yield additional health benefits. We further this research by addressing two related research questions: (1) what is the impact of automobile driving (and especially congestion) on ambient air pollution levels, and (2) what is the impact of modern air pollution levels on infant health? Our setting is California (with a focus on the Central Valley and Southern California) in the years 2002-2007. Using an instrumental variables approach that exploits the relationship between traffic, ambient weather conditions, and various pollutants, our findings suggest that ambient pollution levels, specifically particulate matter, still have large impacts on weekly infant mortality rates. Our results also illustrate the importance of weather controls in measuring pollution’s impact on infant mortality.

The Properties of Radio Galaxies and the Effect of Environment in Large Scale Structures at z∼1z\sim1

In this study we investigate 89 radio galaxies that are spectroscopically-confirmed to be members of five large scale structures in the redshift range of $0.65 \le z \le 0.96$. Based on a two-stage classification scheme, the radio galaxies are classified into three sub-classes: active galactic nucleus (AGN), hybrid, and star-forming galaxy (SFG). We study the properties of the three radio sub-classes and their global and local environmental preferences. We find AGN hosts are the most massive population and exhibit quiescence in their star-formation activity. The SFG population has a comparable stellar mass to those hosting a radio AGN but are unequivocally powered by star formation. Hybrids, though selected as an intermediate population in our classification scheme, were found in almost all analyses to be a unique type of radio galaxies rather than a mixture of AGN and SFGs. They are dominated by a high-excitation radio galaxy (HERG) population. We discuss environmental effects and scenarios for each sub-class. AGN tend to be preferentially located in locally dense environments and in the cores of clusters/groups, with these preferences persisting when comparing to galaxies of similar colour and stellar mass, suggesting that their activity may be ignited in the cluster/group virialized core regions. Conversely, SFGs exhibit a strong preference for intermediate-density global environments, suggesting that dusty starbursting activity in LSSs is largely driven by galaxy-galaxy interactions and merging.Comment: 28 pages, 10 figures, accepted to MNRA

Supplemental Appendix for "The Enrollment of Racially Minoritized Students in Law School: Factors Predicting Within-School Changes Over Time"

Given the substantial lack of racial diversity within the U.S. legal profession, it is important to understand how to improve the representation of racially minoritized students at law schools. This study uses panel data from the 2010s to consider several types of factors that may shape the number and percentage of incoming law school students from several racially minoritized groups: finances (regarding financial aid and cost of attendance), demographic representation (of current students, faculty, and community members), and rankings (from U.S. News). The results of fixed effects analyses revealed that increases in the representation of Latinx and Asian students as well as Faculty of Color predict subsequent decreases in the percentage of incoming racially minoritized students, which suggests that law schools' efforts to recruit racially minoritized students may depend on recent changes in student and faculty representation. Moreover, increases in the ingroup racial representation within the state (in which the law school is primarily housed) and U.S. News rankings are both associated with greater subsequent numbers of incoming Black and Latinx law students; the provision of conditional scholarships and the combined total of tuition and fees are also significant predictors. These findings have salient implications for policy and practice.Table S1. Descriptive Statistics for All Variables Table S2. Unstandardized Coefficients for Random Effects Analyses Predicting Law School Student Enrollment Percentages among All Students Table S3. Unstandardized Coefficients for Random Effects Analyses Predicting Student Enrollment Count

The skill of atmospheric linear inverse models in hindcasting the Madden–Julian Oscillation

A suite of statistical atmosphere-only linear inverse models of varying complexity are used to hindcast recent MJO events from the Year of Tropical Convection and the Cooperative Indian Ocean Experiment on Intraseasonal Variability/Dynamics of the Madden–Julian Oscillation mission periods, as well as over the 2000–2009 time period. Skill exists for over two weeks, competitive with the skill of some numerical models in both bivariate correlation and root-mean-squared-error scores during both observational mission periods. Skill is higher during mature Madden–Julian Oscillation conditions, as opposed to during growth phases, suggesting that growth dynamics may be more complex or non-linear since they are not as well captured by a linear model. There is little prediction skill gained by including non-leading modes of variability.National Science Foundation (U.S.) (Grant 0731520)United States. Office of Naval Research (Grants N00014-10-1-0541, N00014-13-1-0139 and N00014-13-1-0704)National Science Foundation (U.S.) (Grant OCE-0960770

Evolution of a multifunctional trait: shared effects of foraging ecology and thermoregulation on beak morphology, with consequences for song evolution

While morphological traits are often associated with multiple functions, it remains unclear how evolution balances the selective effects of different functions. Birds\u27 beaks function not only in foraging but also in thermoregulating and singing, among other behaviours. Studies of beak evolution abound, however, most focus on a single function. Hence, we quantified relative contributions of different functions over an evolutionary timescale. We measured beak shape using geometric morphometrics and compared this trait with foraging behaviour, climatic variables and song characteristics in a phylogenetic comparative study of an Australasian radiation of songbirds (Meliphagidae). We found that both climate and foraging behaviour were significantly correlated with the beak shape and size. However, foraging ecology had a greater effect on shape, and climate had a nearly equal effect on size. We also found that evolutionary changes in beak morphology had significant consequences for vocal performance: species with elongate-shaped beaks sang at higher frequencies, while species with large beaks sang at a slower pace. The evolution of the avian beak exemplifies how morphological traits can be an evolutionary compromise among functions, and suggests that specialization along any functional axis may increase ecological divergence or reproductive isolation along others

Effects of creatine monohydrate timing on resistance training adaptations and body composition after 8 weeks in male and female collegiate athletes

Background: Limited research is available on the potential impact of creatine monohydrate administration before or after workouts among athletes. This study aimed to investigate the effects of pre- vs. post-exercise creatine monohydrate supplementation on resistance training adaptations and body composition. Methods: In a randomized, double-blind, placebo-controlled, parallel design, 34 healthy resistance-trained male and female athletes were randomly assigned and matched according to fat free mass to consume a placebo, or 5-g dose of creatine monohydrate within 1 h before training, or within 1 h after training for 8 weeks, while completing a weekly resistance training program. Participants co-ingested 25-gram doses of both whey protein isolate and maltodextrin along with each assigned supplement dose. Body composition, muscular strength, and endurance, along with isometric mid-thigh pull were assessed before and after the 8-week supplementation period. A 3 × 2 mixed factorial (group x time) ANOVA with repeated measures on time were used to evaluate differences. Results: All groups experienced similar and statistically significant increases in fat free mass (+1.34 ± 3.48 kg, p = 0.04), upper (+2.21 ± 5.69 kg, p = 0.04) and lower body strength (+7.32 ± 10.01 kg, p \u3c 0.001), and decreases in body mass (−1.09 ± 2.71 kg, p = 0.03), fat mass (−2.64 ± 4.16 kg, p = 0.001), and percent body fat (−2.85 ± 4.39 kg, p \u3c 0.001). Conclusions: The timing of creatine monohydrate did not exert any additional influence over the measured outcomes

Influence of counteranion and humidity on the thermal, mechanical and conductive properties of covalently crosslinked ionenes

Thiol-ene photopolymerization was used to generate a series of covalently crosslinked, imidazolium-containing ionene networks. A variety of counteranions were chosen so as to investigate the influence of size and basicity on the thermal, mechanical and conductive properties of the resulting networks. Anhydrous conductivities at 20 °C were found to be on the order of 10−6 to 10−10 S/cm and correlated to some degree with Tg; however, Tg-normalization of the curves indicated that this relationship between polymer structure and conductivity was more complex. VFT fitting, along with free ion concentration and ion mobility data, were investigated in order to provide additional insight. Also of interest in this study was the influence of humidity on ionic conductivity. Hydrophilic networks with anions such as [Cl], [NO3] or [OMs] were found to exhibit 3- to 5-orders of magnitude enhancement in ionic conductivity (up to 10−3 S/cm) when the relative humidity was increased to 70% while the more hydrophobic networks ([PF6] and [NTf2]) were not influenced. Further experimentation (water uptake, DSC) indicated that the observed enhancements in conductivity were likely due to a combination of plasticization and water-assisted ion transport