Desegregation and Equity in Higher Education and Employment: Is Progress Related to the Desegregation of Elementary and Secondary Schools?

After describing racial inequalities and segregation in higher education and employment, this article considers how the desegregation of elementary and secondary schools may affect these long-term outcomes

Cannabis in Asia: its center of origin and early cultivation, based on a synthesis of subfossil pollen and archaeobotanical studies

Biogeographers assign the center of origin of Cannabis to Central Asia, mostly based on wildtype plant distribution data. We sought greater precision by adding new data: 155 fossil pollen studies (FPSs) in Asia. Many FPSs assign pollen of Cannabis or Humulus (C-H) to collective names (e.g., Cannabis/Humulus or Cannabaceae). To dissect these aggregate data, we used ecological proxies. C-H pollen in a steppe assemblage (with Poaceae, Artemisia, Chenopodiaceae) was identified as wild-type Cannabis. C-H pollen in a forest assemblage (Alnus, Salix, Quercus, Betula, Robinia, Juglans) was identified as Humulus. C-H pollen curves that upsurged alongside crop pollen were identified as cultivated hemp. Subfossil seeds (achenes) at archaeological sites also served as evidence of cultivation. FPSs and archaeological sites were mapped using geographic information system (GIS) software. The oldest C-H pollen consistent with C. sativa dated to 19.6 million years ago (mya), in northwestern China. However, Cannabis and Humulus diverged 27.8 mya, based on molecular clock analysis. We bridged the temporal gap between the divergence date and the oldest pollen by mapping the earliest appearance of Artemisia. These data converge on the northeastern Tibetan Plateau, which we deduce as the C. sativa center of origin. This co-localizes with the first steppe community that evolved in Asia. From there, Cannabis first dispersed west (Europe by 6 mya) then east (eastern China by 1.2 mya). Cannabis pollen in South Asia appeared by 32.6 kya. The earliest Cannabis seeds were found in Japan, 10,000 BCE, followed by China

Tatyana Yakovlevna Serebryakova: a forgotten hemp expert

Tatyana Yakovlevna Serebryakova (1893-?) conducted taxonomic research on Cannabis sativa L. for 20 years. She published important papers and a book on the subject. Next to every great man stands a great woman, and Serebryakova was Vavilov’s hemp expert. Yet her biography has never been written, and many details are lost. We have reconstructed her history based on historical archives, her publications, and her-barium specimen labels. Highlights of her scientific contributions are presented

The Role of Cyclone Activity in Snow Accumulation on Arctic Sea Ice

Identifying the mechanisms controlling the timing and magnitude of snow accumulation on sea ice is crucial for understanding snows net effect on the surface energy budget and sea-ice mass balance. Here, we analyze the role of cyclone activity on the seasonal buildup of snow on Arctic sea ice using model, satellite, and in situ data over 19792016. On average, 44% of the variability in monthly snow accumulation was controlled by cyclone snowfall and 29% by sea-ice freeze-up. However, there were strong spatio-temporal differences. Cyclone snowfall comprised ~50% of total snowfall in the Pacific compared to 83% in the Atlantic. While cyclones are stronger in the Atlantic, Pacific snow accumulation is more sensitive to cyclone strength. These findings highlight the heterogeneity in atmosphere-snow-ice interactions across the Arctic, and emphasize the need to scrutinize mechanisms governing cyclone activity to better understand their effects on the Arctic snow-ice system with anthropogenic warming

Female Salix viminalis are more severely infected by Melampsora spp. but neither sex experiences associational effects

Associational effects of plant genotype or species on plant biotic interactions are common, not least for disease spread, but associational effects of plant sex on interactions have largely been ignored. Sex in dioecious plants can affect biotic interactions with herbivores and pollinators; however, its effects on plant-pathogen interactions are understudied and associational effects are unknown. In a replicated field experiment, we assessed Melampsora spp. leaf rust infection in monosexual and mixed sex plots of dioecious Salix viminalis L. to determine whether plant sex has either direct or associational effects on infection severity. We found no differences in Melampsora spp. infection severity among sexual monocultures and mixtures in our field experiment. However, female plants were overall more severely infected. In addition, we surveyed previous studies of infection in S. viminalis clones and reevaluated the studies after we assigned sex to the clones. We found that females were generally more severely infected, as in our field study. Similarly, in a survey of studies on sexbiased infection in dioecious plants, we found more female-biased infections in plant-pathogen pairs. We conclude that there was no evidence for associational plant sex effects of neighboring conspecifics for either females or males on infection severity. Instead, plant sex effects on infection act at an individual plant level. Our findings also suggest that female plants may in general be more severely affected by fungal pathogens than males

Beyond Spheroids and Discs: Classifications of CANDELS Galaxy Structure at 1.4 < z < 2 via Principal Component Analysis

Important but rare and subtle processes driving galaxy morphology and star-formation may be missed by traditional spiral, elliptical, irregular or S\'ersic bulge/disk classifications. To overcome this limitation, we use a principal component analysis of non-parametric morphological indicators (concentration, asymmetry, Gini coefficient, $M_{20}$, multi-mode, intensity and deviation) measured at rest-frame $B$-band (corresponding to HST/WFC3 F125W at 1.4 $10^{10} M_{\odot}$) galaxy morphologies. Principal component analysis (PCA) quantifies the correlations between these morphological indicators and determines the relative importance of each. The first three principal components (PCs) capture $\sim$75 per cent of the variance inherent to our sample. We interpret the first principal component (PC) as bulge strength, the second PC as dominated by concentration and the third PC as dominated by asymmetry. Both PC1 and PC2 correlate with the visual appearance of a central bulge and predict galaxy quiescence. PC1 is a better predictor of quenching than stellar mass, as as good as other structural indicators (S\'ersic-n or compactness). We divide the PCA results into groups using an agglomerative hierarchical clustering method. Unlike S\'ersic, this classification scheme separates compact galaxies from larger, smooth proto-elliptical systems, and star-forming disk-dominated clumpy galaxies from star-forming bulge-dominated asymmetric galaxies. Distinguishing between these galaxy structural types in a quantitative manner is an important step towards understanding the connections between morphology, galaxy assembly and star-formation.Comment: 31 pages, 24 figures, accepted for publication in MNRA

Neural correlates of eye contact and social function in autism spectrum disorder

Reluctance to make eye contact during natural interactions is a central diagnostic criterion for autism spectrum disorder (ASD). However, the underlying neural correlates for eye contacts in ASD are unknown, and diagnostic biomarkers are active areas of investigation. Here, neuroimaging, eye-tracking, and pupillometry data were acquired simultaneously using two-person functional near-infrared spectroscopy (fNIRS) during live "in-person" eye-to-eye contact and eye-gaze at a video face for typically-developed (TD) and participants with ASD to identify the neural correlates of live eye-to-eye contact in both groups. Comparisons between ASD and TD showed decreased right dorsal-parietal activity and increased right ventral temporal-parietal activity for ASD during live eye-to-eye contact (p≤0.05, FDR-corrected) and reduced cross-brain coherence consistent with atypical neural systems for live eye contact. Hypoactivity of right dorsal-parietal regions during eye contact in ASD was further associated with gold standard measures of social performance by the correlation of neural responses and individual measures of: ADOS-2, Autism Diagnostic Observation Schedule, 2nd Edition (r = -0.76, -0.92 and -0.77); and SRS-2, Social Responsiveness Scale, Second Edition (r = -0.58). The findings indicate that as categorized social ability decreases, neural responses to real eye-contact in the right dorsal parietal region also decrease consistent with a neural correlate for social characteristics in ASD

Center for Research on the Education of Students Placed at Risk: Report #2

The Center for Research on the Education of Students Placed at Risk (CRESPAR) was established in 1994 and continued until 2004. It was a collaboration between Johns Hopkins University and Howard University. CRESPAR’s mission was to conduct research, development, evaluation, and dissemination of replicable strategies designed to transform schooling for students who were placed at risk due to inadequate institutional responses to such factors as poverty, ethnic minority status, and non-English-speaking home background.The first Talent Development High School was established in September 1995 at Patterson High School in Baltimore, Maryland. The model at Patterson, which features career-focused academies for the upper grades, a ninth grade academy with teams of teachers and students, and other key Talent Development components, was designed and developed by the school’s faculty and administration with the participation of Johns Hopkins’ CRESPAR staff as partners. Priorities set for the first year included improvements in school climate, student attendance, and student promotion rates. Early evidence after the first seven months of the 1995–96 school year indicates that, compared to previous years, there is dramatic improvement in overall school climate (student behavior and faculty collegial support), in student attendance, and in expected student promotion rates, especially from ninth grade to tenth grade.Office of Educational Research and Improvement, U. S. Department of Education (R-117-D40005)