Students in rural schools have limited access to advanced mathematics courses

This Carsey brief reveals that students in rural areas and small towns have less access to higher-level mathematics courses than students in urban settings, which results in serious educational consequences, including lower scores on assessment tests and fewer qualified students entering science, technology, engineering, and mathematics (STEM) job pipelines

Mathematics achievement gaps between suburban students and their rural and urban peers increase over time

In this brief, authors Suzanne Graham and Lauren Provost examine whether attending a school in a rural, urban, or suburban community is related to children’s mathematics achievement in kindergarten, and whether increases in mathematics achievement between kindergarten and eighth grade differ for children in rural, urban, and suburban schools. They also consider whether achievement differs by region of the country and for children of different racial and ethnic groups. Finally, they discuss the impact of a family’s socioeconomic status, and the ways in which place and socioeconomic status together affect both early mathematics achievement levels and change over time. They report that rural and urban kindergarten students have slightly lower average mathematics achievement levels than their suburban peers. In addition, the average increase in mathematics achievement from kindergarten to eighth grade for rural and urban children is smaller than the increase for suburban children, resulting in a widening achievement gap over time

Prime divisors of sequences associated to elliptic curves

We consider the primes which divide the denominator of the x-coordinate of a sequence of rational points on an elliptic curve. It is expected that for every sufficiently large value of the index, each term should be divisible by a primitive prime divisor, one that has not appeared in any earlier term. Proofs of this are known in only a few cases. Weaker results in the general direction are given, using a strong form of Siegel's Theorem and some congruence arguments. Our main result is applied to the study of prime divisors of Somos sequences

Reading levels of rural and urban third graders lag behind their suburban peers

This brief examines the complex interplay of family, school, and place factors in the reading achievement levels of third grade students. Third grade reading achievement is critical to later academic and occupational success. Using data from the Early Childhood Longitudinal Study, the authors report that suburban children realize greater gains in reading achievement from kindergarten to Grade 3 than their rural or urban counterparts. Rural students who were struggling readers at the beginning of kindergarten have lower average reading achievement in third grade than both urban and suburban students when children of the same socioeconomic status are compared. The differences in third grade reading achievement between rural and nonrural children who were low achievers in kindergarten most likely reflect different educational opportunities and school resources available to these children. The authors suggest that improved professional development opportunities for rural teachers may help narrow the differences in the third grade reading achievement of rural, urban, and suburban students who were struggling readers in kindergarten

Interrupting the Response of \u3ci\u3eDendroctonus Simplex\u3c/i\u3e Leconte (Coleoptera: Curculionidae: Scolytinae) to Compounds That Elicit Aggregation of Adults

The eastern larch beetle, Dendroctonus simplex LeConte (Coleoptera: Curculionidae: Scolytinae), is a native bark beetle that has caused significant mortality to tamarack, Larix laricinia, in the Upper Peninsula of Michigan. The effectiveness of potentially attractive chemicals for D. simplex was tested and the most attractive compound, seudenol, was used in subsequent studies to test interruptants against D. simplex. Verbenone, methylcyclohexenone (MCH), and 4-allylanisole were tested as potential interruptants in combination with seudenol. Catches of D. simplex in traps baited with seudenol and MCH were not significantly different from catches in unbaited control traps, indicating successful interruption of the response to seudenol by MCH. Verbenone released at commercially available doses significantly increased catches of D. simplex in traps baited with seudenol, however it did not catch significantly more D. simplex than the unbaited control traps when released alone. Traps baited with 4-allylanisole did not significantly reduce the number of D. simplex captured compared to traps baited solely with seudenol. The potential for MCH to be used to protect individual trees and in stand level management of D. simplex is discussed

Acoustic emission frequency discrimination

In acoustic emission nondestructive testing, broadband frequency noise is distinguished from narrow banded acoustic emission signals, since the latter are valid events indicative of structural flaws in the material being examined. This is accomplished by separating out those signals which contain frequency components both within and beyond (either above or below) the range of valid acoustic emission events. Application to acoustic emission monitoring during nondestructive bond verification and proof loading of undensified tiles on the Space Shuttle Orbiter is considered