13,369 research outputs found
Analysis of partial-reflection data from the solar eclipse of 10 Jul. 1972
Partial-reflection data collected for the eclipse of July 10, 1972 as well as for July 9 and 11, 1972, are analyzed to determine eclipse effects on D-region electron densities. The partial-reflection experiment was set up to collect data using an on-line PDP-15 computer and DECtape storage. The electron-density profiles show good agreement with results from other eclipses. The partial-reflection programs were changed after the eclipse data collection to improve the operation of the partial-reflection system. These changes were mainly due to expanded computer hardware and have simplified the operations of the system considerably
The Effect of Test Difficulty on Perceived Memory Performance
Neuropsychological testing is a critical element of the assessment and treatment of a host of neurological disorders, such as Alzheimer’s Disease, stroke, and traumatic brain injury. Certain non-neurological variables may also affect an individual’s test performance. Such secondary factors may include current psychiatric issues, chronic pain, sleep, and the effort put forth during testing. Little is known, however, about the effect the testing process itself has on people’s actual and perceived cognitive abilities. For example, the process of undergoing memory testing may, through a variety of mechanisms, influence memory performance and impact the person such that their view of their memory function changes. To effectively assess and treat patients, it is necessary to understand the influence our assessment methods have on patients’ memory test scores and the extent to which the assessment experience alters their self-concept. Thus, this project examined the effects of test difficulty on self-reported memory ability. A sample (n = 59) of undergraduate students and healthy older adults took two standardized neuropsychological tests of memory with differing levels of difficulty and rated their memory abilities at baseline and after each test. It was hypothesized that self-reported memory abilities would be higher after taking the easy test, and lower after taking the hard test. The results of this study may help clinicians better understand the impact their assessment techniques may have on examinees and how results from neuropsychological evaluations may be best used to help individuals make appropriate adjustments to their memory difficulties
Overview of the Main Propulsion System for a Nuclear Thermal Propulsion Flight Demonstrator
A demonstration of a Nuclear Thermal Propulsion (NTP) engine has not been conducted in over 50 years. Several tests were conducted during the NERVA program but no NTP engine was ever flown in space. In the last several years there has been a considerable amount of conceptual design work on NTP engines conducted. With the prospect of human Mars missions in the 2030s there has been a renewed interest in NTP engines. A concept design study was conducted with the intent to design 2 flight demonstrator vehicles that would buy down programmatic and technical risks associated with launching and operating nuclear reactors in space. The intent of the first demonstrator mission would be to employ a simplified NTP engine and buy down programmatic risks whereas the second demonstrator would buy down technical risks with a NTP engine designed to be similar to an operational NTP model. The results of the study showed that a simplified NTP engine demonstrator could be feasibly built and flown in the near term with mostly high TRL, commercial off-the-shelf components
Conservation evo-devo: preserving biodiversity by understanding its origins
Unprecedented rates of species extinction increase the urgency for effective conservation biology management practices. Thus, any improvements in practice are vital and we suggest that conservation can be enhanced through recent advances in evolutionary biology, specifically advances put forward by evolutionary developmental biology (i.e., evo-devo). There are strong overlapping conceptual links between conservation and evo-devo whereby both fields focus on evolutionary potential. In particular, benefits to conservation can be derived from some of the main areas of evo-devo research, namely phenotypic plasticity, modularity and integration, and mechanistic investigations of the precise developmental and genetic processes that determine phenotypes. Using examples we outline how evo-devo can expand into conservation biology, an opportunity which holds great promise for advancing both fields
Assessing the Impacts of Inorganic and Organic Fertilizer on Crop Performance Under a Microirrigation-Plastic Mulch Regime
Abstract
This study was conducted at S & B Farm located in Eufaula, AL in 2014. The treatments were Inorganic fertilizer/“Farmer’s Mix” (NPK 13:13:13 + ammonium nitrate mixed in 3:1 ratio); Inorganic fertilizer/“Farmer’s Mix” (NPK 13:13:13 + ammonium nitrate mixed in 3:1 ratio + Bio-grow) plus microbe mix; and Organic Fertilizer – Mighty Grow (4-3-4) with a microbe mix. All fertilizers were applied prior to mulch application after which the following crops squash (Cucurbita pepo L.), cucumber (Cucumis sativus L.), and okra (Abelmoschus esculentus L. Moench) were directly seeded in a complete randomized design. The results showed that the inorganic fertilizer had higher yields (lbs/acre) than organic fertilizer. The addition of microbes to the inorganic fertilizer significantly increased the numbers of cucumbers and okra per acre. Overall, the “Farmer mix” with or without the addition of microbes significantly increased yields for all crops compared to the organic-based fertilizer
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