Circadian Rhythms of the Spider Pholcus phalangeoides in Activity Monitors and Web Boxes

Circadian rhythms are endogenous molecular clocks that correspond to the 24-hour day and are regulated by light stimulus, allowing organisms to entrain to the dawn-dusk cycle. These clocks may allow organisms to anticipate daily events, influencing their behavior. In arthropods, including spiders, circadian rhythmicity is tested using activity monitors, which house individuals in tubes. However, this does not reflect the natural habitat of many spiders. We compared the locomotor activity of the cellar spider Pholcus phalangiodes in activity monitors with the locomotor activity in web boxes. After being entrained to a 12:12 light:dark cycle, the spiders were recorded in constant darkness. The resulting free-running periods demonstrated similar clock data for spiders in tubes as in boxes. This validates the activity-monitor research method

Black and White Student Achievement Gaps in Tennessee

Achievement gaps between Black students and White students have existed since public education was desegregated, and they still persist despite efforts to close the gap. This research describes the achievement gaps between Black and White 3rd through 8th grade students in the state of Tennessee from 2017-2019. This is a non-experimental, quantitative, comparative-analysis describing the ELA and math test scores of Black students and White students in each of the three geographic regions of Tennessee. Data were arranged in 2x2 contingency matrixes to compare the expected frequencies of students in each race scoring on-track and mastered versus below and approaching. The data from the matrixes were analyzed in SPSS using Chi Squared tests to determine if the difference between Black student scores and White student scores was statistically significant. All twelve test score groupings showed an achievement gap between Black students and White students. The largest achievement gap was in West Tennessee’s elementary school ELA scores. The smallest achievement gap was in West Tennessee’s middle school math scores. Although there were gaps between Black students and White students in all twelve groupings, East Tennessee’s gaps were the smallest overall, ELA scores had smaller gaps than math scores in general, and middle school had smaller gaps than elementary school. These significant findings suggest there is much work to be done in Tennessee to close the gap between Black students and White students in order to provide a more equitable school experience

Sedimenting canals

CER60RDD2.For presentation at the 9th annual meeting of Four States Irrigation Council, Denver, Colorado, January 14-15, 1960

Bentonite sediment sealing activities in lateral E-65-19.3 of the Central Nebraska Public Power and Irrigation District

CER58RDD23.June 1958.Preliminary report-subject to revision.CSU Research Foundation project 108.Includes bibliographical references.Prepared for Agricultural Research Service, U.S. Department of Agriculture, under terms of ARS contract no. 12-14-100-507(41)

Field trip report relating to bentonite sedimenting of canals in Wheatland Irrigation District, Wheatland, Wyoming

CER57RDD30.Prepared for the Wyoming Natural Resource Board and the Wheatland Irrigation District

Review of development of the bentonite sedimenting method of sealing irrigation canals, A

CER59RDD8.March 1959

Investigating the impact of land-use land-cover change on Indian summer monsoon daily rainfall and temperature during 1951–2005 using a regional climate model

Daily moderate rainfall events, which constitute a major portion of seasonal summer monsoon rainfall over central India, have decreased significantly during the period 1951 through 2005. On the other hand, mean and extreme near-surface daily temperature during the monsoon season have increased by a maximum of 1–1.5 °C. Using simulations made with a high-resolution regional climate model (RegCM4) and prescribed land cover of years 1950 and 2005, it is demonstrated that part of the changes in moderate rainfall events and temperature have been caused by land-use/land-cover change (LULCC), which is mostly anthropogenic. Model simulations show that the increase in seasonal mean and extreme temperature over central India coincides with the region of decrease in forest and increase in crop cover. Our results also show that LULCC alone causes warming in the extremes of daily mean and maximum temperatures by a maximum of 1–1.2 °C, which is comparable with the observed increasing trend in the extremes. Decrease in forest cover and simultaneous increase in crops not only reduces the evapotranspiration over land and large-scale convective instability, but also contributes toward decrease in moisture convergence through reduced surface roughness. These factors act together in reducing significantly the moderate rainfall events and the amount of rainfall in that category over central India. Additionally, the model simulations are repeated by removing the warming trend in sea surface temperatures over the Indian Ocean. As a result, enhanced warming at the surface and greater decrease in moderate rainfall events over central India compared to the earlier set of simulations are noticed. Results from these additional experiments corroborate our initial findings and confirm the contribution of LULCC in the decrease in moderate rainfall events and increase in daily mean and extreme temperature over India. Therefore, this study demonstrates the important implications of LULCC over India during the monsoon season. Although, the regional climate model helps in better resolving land–atmosphere feedbacks over the Indian region, the inferences do depend on the fidelity of the model in capturing the features of Indian monsoon realistically. It is proposed that similar studies using a suite of climate models will further enrich our understanding about the role of LULCC in the Indian monsoon climate

The Sensitivity of Simulated River Discharge to Land Surface Representation and Meteorological Forcings

Abstract The discharge of freshwater into oceans represents a fundamental process in the global climate system, and this flux is taken into account in simulations with general circulation models (GCMs). Moreover, the availability of realistic river routing schemes is a powerful instrument to assess the validity of land surface components, which have been recognized to be crucial for the global climate simulation. In this study, surface and subsurface runoff generated by the 13 land surface schemes (LSSs) participating in the Second Global Soil Wetness Project (GSWP-2) are used as input fields for the Hydrology Discharge (HD) routing model to simulate discharge for 30 of the world's largest rivers. The simplest land surface models do not provide a good representation of runoff, and routed river flows using these inputs are affected by many biases. On the other hand, HD shows the best simulations when forced by two of the more sophisticated schemes. The multimodel ensemble GSWP-2 generates the best phasing of the annual cycle as well as a good representation of absolute values, although the ensemble mean tends to smooth the peaks. Finally, the intermodel comparison shows the limits and deficiencies of a velocity-constant routing model such as HD, particularly in the phase of mean annual discharge. The second part of the study assesses the sensitivity of river discharge to the variation of external meteorological forcing. The Center for Ocean–Land–Atmosphere Studies version of the SSiB model is constrained with different meteorological fields and the resulting runoff is used as input for HD. River flow is most sensitive to precipitation variability, but changes in radiative forcing affect discharge as well, presumably because of the interaction with evaporation. Also, this analysis provides an estimate of the sensitivity of river discharge to precipitation variations. A few areas (e.g., central and eastern Asia, the Mediterranean, and much of the United States) show a magnified response of river discharge to a given percentage change in precipitation. Hence, an amplified effect of droughts as indicated by the consensus of climate change predictions may occur in places such as the Mediterranean. Conversely, increasing summer precipitation foreseen in places like southern and eastern Asia may amplify floods in these poor and heavily populated regions. Globally, a 1% fluctuation in precipitation forcing results in an average 2.3% change in discharge. These results can be used for the definition and assessment of new strategies for land use and water management in the near future