Space shuttle: Basic hypersonic force data for Grumman delta wing orbiter configurations ROS-NB1 and ROS-WB1

Hypervelocity wind tunnel tests at Mach 10 of delta wing space shuttle model

Richard Nixon to C.C. Johnson Spink thanking him for his support. January 14, 1972

Richard Nixon to C.C. Johnson Spink thanking him for his support. January 14, 197

Impacts of Open Educational Resources on Enrollment Rates, Withdrawal Rates, and Academic Performance in the Virginia Community College System

The problem of this study was to evaluate the enrollment rates and academic performance of students in courses at Central Virginia Community College (CVCC) that utilize Open Educational Resources (OER) to help determine if the use of such materials should be encouraged and expanded in the Virginia Community College System. The population for this study consisted of students enrolled in at least one course at CVCC during the Fall 2015 and Spring 2016 semester, where there were courses that used OER as the course textbook. At the end of each semester, CVCC records enrollment, drop, and academic performance information for all enrolled students. These data were provided by CVCC’s Office of Institutional Research. The first research question of this study asked if the enrollment rate in courses at CVCC that use OER differs from other sections of the same course that use textbooks students are required to obtain. This question was examined with contingency tables. The second research question of this study asked if replacing a required text with OER increases the completion rate in those courses as compared to non-OER courses. A Chi-square analysis was used. The third research question of this study asked if CVCC students’ academic performance was affected by the use of OER. Multiple t-tests were performed to examine the question. A statistically significant difference in enrollment rates was found in two of the ten courses studied. The difference in withdrawal rates for all courses and subjects in aggregate was found to be statistically significant. A statistically significant difference in student academic performance was found in 12 out of 20 comparisons made. The results and conclusions of this study are at odds with other studies done in the subject area. The enrollment rate in OER taught courses in these subjects did not differ from the enrollment rate in non-OER taught courses. Students withdrew from OER sections at a significantly higher rate than from non-OER sections. Student performance of this sample in aggregate was extremely significantly affected by the use of OER

Synthetic Studies on Small Molecule Modulators of Src Homology 2 (SH2) Domain-Containing Inositol 5’-Phosphatase (SHIP)

Small molecule modulators of SH2-containing inositol 5’-phosphatase (SHIP) have recently become a hotly pursued area in medicinal chemistry. Pharmaceutical targeting of SHIP with small molecules has been identified as a new method to directly influence the phosphoinositide 3-kinase (PI3K) cell signaling pathway. Modulation of this pathway may be utilized in the development of interesting new therapeutics. A better understanding of the role that SHIP phosphatase activity plays in a number of disease states ranging from cancer to autoimmune disease to obesity may be ascertained by use of small molecule inhibitors. These investigations involved the synthesis of aminosteroid inhibitors and a variety of aminosteroid analogs to allow for further evaluation of structure-activity relationships in these systems for both potency and selectivity against both paralogs of SHIP, SHIP1 (primarily expressed in hematopoietic cells) and SHIP2 (expressed across all cell types). SHIP1 has also been recognized to be an allosterically activated enzyme, with several small molecule agonists having been reported in the literature. These studies have culminated in the identification of AQX-1125, which is currently undergoing phase III clinical evaluation for interstitial cystitis / bladder pain syndrome. To facilitate our own studies on SHIP1 signaling, a new synthetic route to the SHIP1 agonist AQX-1125 has been developed. This route allows for more rapid access to AQX-1125 from dehydroepiandrosterone than the published synthetic pathway, saving time and resources. Key features of the new route include utilizing an allylic oxidation, ozonolysis, and lactonization for a more selective and controlled synthesis. In addition, this work has led to the synthesis of several new AQX-1125 analogs, providing information on structure activity relationships in this structural class of SHIP1 agonists

Respuesta del Presidente de los Estados Unidos de América, señor Richard M. Nixon, al mensaje del Presidente de Colombia, doctor Misael Pastrana Borrero

Se presenta a continuación la respuesta del señor Richard M. Nixon, Presidente de los Estados Unidos de América, al mensaje dirigido por el Presidente de Colombia, doctor Misael Pastrana Borrero el 21 de diciembre próximo pasado, cuyo contenido se publicó en nuestra revista correspondiente al mes de diciembre de 1971

Antimalarijska, antimikobakterijska i antiproliferativna aktivnost fenil-supstituisanih tetraoksana

Mixed tetraoxanes of the 4"-phenyl-substituted cyclohexyl-spirotetraoxacyclohexyl-spirocholate series have been prepared and evaluated as possible antimalarials, anti-proliferatives and antimycobacterials. The activity of the (4"R or S)-phenyl series against P falciarum D6 and W2 strains was found to be at the level of artemisinin. with two compounds. the acid 4 and the amide 6, exhibiting encouraging anti-TB activity as well. Very promising in vitro results of the said tetraoxanes were obtained against solid tumours and, in some instances. the activity against a selected number of cell lines was higher than that of the antitumor drug paclitaxel.U ovom radu prikazana je sinteza serije mešovitih tetraoksana 4"-fenil-supstituisanih cikloheksil-spirotetraoksacikloheksil-spiroholata, a ispitana je i njihova in vitro aktivnost kao mogućih antimalarika, anti-TBC agenasa i antiproliferativnih jedinjenja. Aktivnost (4"R ili S)-fenil serije na D6 i W2 sojeve P. falciparum vrlo je slična aktivnosti poznatog antimalarika artemizinina. Izraženu anti-TBC aktivnost iskazala su jedinjenja 4 i 6, čija antiproliferativna in vitro aktivnost prema nekim kompaktnim tumorima prevazilazi aktivnost leka paklitaksela

Shikimate pathway in apicomplexan parasites

No abstract available

Sediment transport in a gravel-bottomed stream

Sediment transport in a gravel-bottomed stream located in the Oregon Coast Range was studied to determine the effects of a single layer of large particles (the armour layer) located at the surface of the bed material. The bed load transport system was studied jointly with suspended sediment transport to understand the total transport system. The bed load was sampled using a vortex trough in the stream bed which transported the bed load material into a sampling pit adjacent to the stream. It was found that the armour layer controls the bed load transport system by preventing sand and finer material from the bed from being entrained in the flow unless the armouring particles are first moved. The bed load of an armoured stream can be calculated using the simplified Einstein bed load function with a representative diameter for the stability parameter equal to the particle size of armouring material at which 35% of the material is finer (D35 size) and a representative size for the transport parameter equal to the median site of bed material below the armour layer. The critical discharge for disturbing the armour layer is related to a size equal to 69% of the D65 size. The critical shear stress of the armouring material is at a minimum for a particle equal to the 0.69 D65 size. Smaller particles are hidden in the armour layer and larger particles are heavier than the critical particle. From observation of the maximum size of particles transported for various stream discharges, the Shields parameter was found to be 0.025 for a rough bed and for a transport rate of very nearly zero. The suspended sediment transport system was found to be partially related to the past history of the stream because the past history f flows and sediment load controls the ability of the armour layer to remove sand and finer material from the water in the stream or to supply these smaller particles to the water. Both the bed load and suspended load of Oak Creek are quite variable when the discharge is below the critical discharge of the armour layer

O peroksidnim antimalaricima

Several dicyclohexylidene tetraoxanes were prepared in order to gain a further insight into structure-activity relationship of this kind of antimalarials. The tetraoxanes 2-5, obtained as a cis/trans mixture, showed pronounced antimalarial activity against Plasmodium falciparum chloroquine susceptible D6, chloroquine resistant W2 and multidrug-resistant TM91C235 (Thailand) strains. They have better than or similar activity to the corresponding desmethyl dicyclohexylidene derivatives. Two chimeric endoperoxides with superior antimalarial activity to the natural product ascaridole were also synthesized.U ovom radu prikazana je sinteza nekoliko dicikiloheksilidenskih tetraoksana u cilju sagledavanja odnosa struktura-aktivnost ove vrste antimalarika. Jedinjenja 2-5 dobijena kao (cis,trans)-smese pokazala su izraženu antimalarijsku aktivnost prema D6, W2 i TM91C235 (Thailand) sojevima P. falciparum. Ona imaju bolju ili sličnu aktivnost od odgovarajućih desmetil cikloheksilidenskih derivata. Sintetisana su i dva endoperoksida himerne strukture znatno izraženije aktivnosti od prirodnog proizvoda askaridola.