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We use data from the Stanford Education Data Archive to describe district-level trends in average academic achievement between 2009 and 2019. Although on average school districts’ test scores improved very modestly (by about 0.001 standard deviations per year), there is significant variation among districts. Moreover, we find that average test score disparities between nonpoor and poor students and between White and Black students are growing; those between White and Hispanic students are shrinking. We find no evidence of achievement-equity synergies or trade-offs: Improvements in overall achievement are uncorrelated with trends in achievement disparities. Finally, we find that the strongest predictors of achievement disparity trends are the levels and trends in within-district racial and socioeconomic segregation and changes in differential access to certified teachers.

This study complements literature on state policymaking by exploring one state’s achievement trends and policymaking during a period of remarkable achievement gains. I use mixed methods, drawing on hierarchical linear modeling and semi-structured interviews with policy actors, to explore the case of Tennessee in the post-recession period. Results indicate that Tennessee’s school districts improved faster than districts in other states during this period without doing so at the expense of historically disadvantaged student groups. I argue that Tennessee’s trends are a result of strong policies and a robust approach to the policymaking process.

Dual enrollment is an increasingly popular avenue for high school students to earn college credit. However, low-income students are underrepresented among dual enrollment participants. In this study, we use a difference-in-differences design to evaluate a unique federal pilot program that allowed high school students to access Pell Grants to fund their dual enrollment. Generally, we find a negative effect of the pilot program on dual enrollment participation, with no effect on subsequent college attendance. Our qualitative analysis suggests this initiative did not sufficiently meet students’ specific needs, required strong partnerships with high schools to ensure high school counselors informed students about the program, and involved substantial financial and administrative burden for participating institutions.

This study considers the role of religious habitus and self-concept in educational stratification. We follow 3,238 adolescents for 13 years by linking the National Study of Youth and Religion to the National Student Clearinghouse. Survey data reveal that girls with a Jewish upbringing have two distinct postsecondary patterns compared to girls with a non-Jewish upbringing, even after controlling for social origins: (1) they are 23 percentage points more likely to graduate college, and (2) they graduate from much more selective colleges. We then analyze 107 interviews with 33 girls from comparable social origins interviewed repeatedly between adolescence and emerging adulthood. Girls raised by Jewish parents articulate a self-concept marked by ambitious career goals and an eagerness to have new experiences. For these girls, elite higher education and graduate school are central to attaining self-concept congruence. In contrast, girls raised by non-Jewish parents tend to prioritize motherhood and have humbler employment aims. For them, graduating from college, regardless of its prestige, is sufficient for self-concept congruence. We conclude that religious subculture is a key factor in educational stratification, and divergent paths to self-concept congruence can help explain why educational outcomes vary by religion in gendered ways.

We present new discoveries and results from long-term timing of 72 pulsars discovered in the Arecibo PALFA survey, including precise determination of astrometric and spin parameters, and flux density and scatter broadening measurements at 1.4 GHz. Notable discoveries include two young pulsars (characteristic ages $\sim$30 kyr) with no apparent supernova remnant associations, three mode changing, 12 nulling and two intermittent pulsars. We detected eight glitches in five pulsars. Among them is PSR J1939+2609, an apparently old pulsar (characteristic age $\sim$1 Gy), and PSR J1954+2529, which likely belongs to a newly-emerging class of binary pulsars. The latter is the only pulsar among the 72 that is clearly not isolated: a non-recycled neutron star with a 931-ms spin period in an eccentric ($e\,=\,0.114$) wide ($P_b\,=\,82.7\,$d) orbit with a companion of undetermined nature having a minimum mass of $\sim0.6\,M_{\odot}$. Since operations at Arecibo ceased in 2020 August, we give a final tally of PALFA sky coverage, and compare its 207 pulsar discoveries to the known population. On average, they are 50% more distant than other Galactic plane radio pulsars; PALFA millisecond pulsars (MSP) have twice the dispersion measure per unit spin period than the known population of MSP in the Plane. The four intermittent pulsars discovered by PALFA more than double the population of such objects, which should help to improve our understanding of pulsar magnetosphere physics. The statistics for these, RRATS, and nulling pulsars suggest that there are many more of these objects in the Galaxy than was previously thought., 39 pages, 18 figures, 9 tables. Accepted for publication in ApJ

In this paper we present a brief summary of prehistoric agricultural develop­ ments as they are presently understood in the New World. Constraints prevent detailed evaluation of all of the cultural areas defined in the New World. Emphasis is placed, therefore, on Mesoamerica and the Central Andes, where aboriginal high cultures were found. The American Southwest, Midwest, Southeast, and Eastern Woodlands are not treated even though agriculture was an important part of cultural development in those areas. The fact that many important cultigens now shared by the world came from the Mesoamerican and Central Andean areas places a priority on understanding something about food production of the American past. Within these cultural areas we attempt to show research trends that have occurred over the past two decades. Since more intensive work has been done in Mesoamerica, it receives the greatest attention. The central question for Mesoamerica and the Central Andes has been the relationship of food produc­ tion to the rise and fall of the state ( 15, 57, 73, 108, 1 17). Over the past decade the question has been redefined in terms of a significant increase in information obtained from an extensive amount of fieldwork.

Obsidian artifacts from Edzna, Dzibilnocac, and Santa Rosa Xtampak in northern Campeche, Mexico, have been analyzed by means of X-ray fluorescence in order to determine their trace element composition. The results are compared to the trace element composition of obsidian sources in Guatemala and Mexico. It is postulated that the obsidian from the three sites in northern Campeche came from highland Guatemala, mostly from El Chayal. Our data are compared to the published data of other archaeological sites in Mesoamerica from which obsidian samples have been analyzed. Finally, obsidian transport routes are postulated between northern Campeche, Mexico, and highland Guatemala.

Heavy jungle growth prevented economical surveying of Aguacatal (Campeche, Mexico) and the adjacent area despite the efforts of two brief seasons in the field. Aerial photography was used to supplement and expeditiously complete the ground survey work. The operation was inexpensive and utilized readily available equipment such as the K-20 aerial camera. Super-XX, infrared, and color films were used on an experimental basis to determine which film was best suited for archaeologic purposes. All films were found to have special values: Super-XX — the best general film for gray tonal renditions of vegetal differentiation; infrared — for the delineation of wet areas and water courses; and color — for the maximum readability of color differences. Photographic interpretation proved reliable and allowed the archaeologist to extract topographic, ecologic, and archaeologica data from the photographs with little laboratory study.

Test excavations at Aguacatal, located on the Xicalango peninsula, western Campeche, revealed chultuns (water cisterns) of the Late Classic period. Modern chultun construction by Chontal Indians, as late as the 1940's, followed the Late Classic period methods and style. First hand descriptions of the construction and use of chultuns by the Chontol is an aid in archaeological interpretation. Department of Anthropology and Archaeology Brigham Young University December, 1970 The site of Aguacatal is located on the Xicalango peninsula, western coast of Campeche, about 20 km east of Atasta, and about 15 km west of the Laguna de Terminos. The peninsula is built up of recent alluvial and eaty recently enacted b twe n th United tates and Mexico which may result in a mar n sediments which are only 3 m above sea level at the highest point. Ground water is high, fluctuating with the tides, and is brackish. Vegetation is tropical, bordering to a rainforest type on the highest points of land, changing to a swamp type where the land is low. Modern wells, which are necessarily shallow, supply water for cattle, gardening, washing clothes, and for drinking in time of drought. Most households obtain drinking and cooking water from above-ground, concrete cisterns, built next to houses. These cisterns collect rainwater from grass and palm frond thatched roofs by means of board gutters temporarily placed under the eaves. Cisterns are 2-3xlxl m or smaller, holding potentially up to about 30001 of water. Rains, occurring from the end of May through September, usually provide enough water to fill the cisterns plus take care of normal needs for drinking and cooking for much of the year. However, cisterns are dry or nearly dry the following April unless a tropical storm occurs which temporarily replenishes the water supply. Some cisterns are capped with planks, or concrete slabs; others are left open. All have a heavy growth of algae a few months into the rainy season and provide a hatching place for many visible forms of animal life. Test excavations at Aguacatal in mound structures revealed several Late Classic period chultuns. These chultuns are always located on earthen constructions well above ground level and probably were adjacent to house structures. Chultuns are often found close to one another. Some are built over others, or show evidence of rebuilding, using the same excavation. Chultuns are always constructed in earthen mounds, none being found in limestone as are found elsewhere on the Yucatan peninsula (Thompson, PMAAE HARVARD, MEM. 1, 1897:3; Pollock, PMAAE HARVARD, PAPS. 61, 1970). The latter chultuns of the Yucatan peninsula are carved in solid limestone bedrock with walls curving outward, permitting a huge volume of space below the neck (Fig. 1). The Aguacatal chultuns, being excavations in soil, do not permit much expansion below the neck because of a lack of strength in the soil and in cross section, some are bottle-shaped, that is, have a restricted neck, a larger volume of space below, but with interior walls tapering inward or i are o l 3 above sea i t. round ater is high, i es, a d is brackish. i l, eri g to a rainforest i ts of land, changing to e la is lo . odern ssa il s a lo , supply i , ashing clothes, i i e of drought. ost i i a d cooking water , c ete cisterns, built 473 This content downloaded from 157.55.39.35 on Thu, 01 Sep 2016 05:34:21 UTC All use subject to http://about.jstor.org/terms [Vol. 36, No. 4, 1971 nearly vertical (Fig. 2). In plan form, some of the chultuns are clover-shaped (Fig. 2), probably to increase the strength of the earthen structure. The Aguacatal chultuns are small in comparison to those found on the Yucatan peninsula. Dimensions of the former constructions will have interior walls 70-120 cm in diameter and 150-180 cm deep, giving a potential capacity for the larger type of about 1600 1. The Yucatan chultuns have huge capacities, ranging from 7 m3 to over 50 m3 of space and having the potential of holding from 71,000 to over 500,0001. The Aguacatal chultuns are lined with clay 20-25 cm thick which has been fired. The clay was fired in place on the interior walls showing gray colors and pieces of charcoal imbedded into it. Earth behind the clay liner is bured. Mollusk shells used in mound construction are often reduced to lime concretions, indicating considerable heat generated during the firing process. In 1 instance, lime cement was used to form the rim, which probably supported a protective cap, at the mouth of a chultun (Fig. 2). Chontal-speaking Indians were employed in excavation at the site. When asked whether or not they recognized the structure that was being excavated, they all agreed and called it a chultun. Then 2 men in their late thirties related the following experience with chultuns: In their youth (late 1930's, early 1940's), they had helped their fathers construct chultuns similar to those being excavated. First, the excavation was made on high ground at a suitable location for a

Publisher Summary This chapter focuses on the two elements vital to man's survival, that is, water and soil, and describes how the ancient Maya manipulated these elements in lowland and highland settings. It appears that the lowland and highland Maya left little to chance when it came to water and soil resources. Technologies for extracting, collecting, and retrieving water in both areas were highly developed. At large sites, this often involved the organization of a large number of laborers and the conceptualization of a complex plan. At small- and medium-sized sites in the lowlands and highlands, a number of smaller scale manipulations of soil and water resources were carried out. In many cases, the Maya used a number of techniques at the same site to insure that there would be enough food and water to support their population. After the initial investment of building the systems of soil and water control, additional investment was required to maintain and preserve the systems. In the case of the larger sites, this may have proved burdensome and difficult to maintain, particularly during periods of decline or political instability. Present evidence leaves no doubt that the Maya devised and used a large number of techniques in both lowland and highland settings to give them control over soil and water.

Metabolism in males and females is distinct. Differences are usually linked to sexual reproduction, with circulating signals (e.g. hormones) playing major roles. By contrast, sex differences prior to sexual maturity and intrinsic to individual metabolic tissues are less understood. We analyzed Drosophila melanogaster larvae and find that males store more fat than females, the opposite of the sexual dimorphism in adults. We show that metabolic differences are intrinsic to the major fat storage tissue, including many differences in the expression of metabolic genes. Our previous work identified fat storage roles for Spenito (Nito), a conserved RNA-binding protein and regulator of sex determination. Nito knockdown specifically in the fat storage tissue abolished fat differences between males and females. We further show that Nito is required for sex-specific expression of the master regulator of sex determination, Sex-lethal (Sxl). "Feminization" of fat storage cells via tissue-specific overexpression of a Sxl target gene made larvae lean, reduced the fat differences between males and females, and induced female-like metabolic gene expression. Altogether, this study supports a model in which Nito autonomously controls sexual dimorphisms and differential expression of metabolic genes in fat cells in part through its regulation of the sex determination pathway.