An assessment and validation study of nuclear reactors for low power space applications

The feasibility and safety of six conceptual small, low power nuclear reactor designs was evaluated. Feasibility evaluations included the determination of sufficient reactivity margins for seven years of full power operation and safe shutdown as well as handling during pre-launch assembly phases. Safety evaluations were concerned with the potential for maintaining subcritical conditions in the event of launch or transportation accidents. These included water immersion accident scenarios both with and without water flooding the core. Results show that most of the concepts can potentially meet the feasibility and safety requirements; however, due to the preliminary nature of the designs considered, more detailed designs will be necessary to enable these concepts to fully meet the safety requirements

Indian Meal Moth Survivability in Stored Corn With Different Levels of Broken Kernels

Survivability of Indian meal moth, Plodia interpunctella (Hübner) (Lepi-doptera: Pyralidae), larvae fed a standard laboratory diet and whole corn with 0, 5 to 7, and 100% broken corn kernels, was assessed under laboratory conditions at 28o C, 65% relative humidity, and 14:10 h (L:D) photoperiod. A conventional yellow dent corn hybrid (about 3.9% oil content, dry basis) and a high-oil corn hybrid (about 7.7% oil content, dry basis) were tested. Survivability was measured as the percentage of pre-pupae, pupae, and adults observed at the end of the rearing period. For the standard laboratory diet, a mean of 97.5% larvae survived. Percentage of larval survival increased as the percentage of broken corn increased. Mean percentages of larval survival for the conventional yellow dent corn were 6.7, 63.8, and 80.0 for 0, 7, and 100% broken kernels, respectively. The mean percentages of larval survival for the high-oil corn hybrid were 28.3, 81.3, and 100.0 for 0, 5, and 100% broken kernels, respectively. Larval growth rate for high-oil corn was faster than for conventional corn. Results indicate that cleaning corn before storage could reduce P. interpunctella problems

Heterogeneous nucleation is required for crystallization of the ZnuA domain of pneumococcal AdcA

Zn2+ is an essential nutrient for all known forms of life. In the major human pathogen Streptococcus pneumoniae, the acquisition of Zn2+ is facilitated by two Zn2+-specific solute-binding proteins: AdcA and AdcAII. To date, there has been a paucity of structural information on AdcA, which has hindered a deeper understanding of the mechanism underlying pneumococcal Zn2+ acquisition. Native AdcA consists of two domains: an N-terminal ZnuA domain and a C-terminal ZinT domain. In this study, the ZnuA domain of AdcA was crystallized. The initial crystals of the ZnuA-domain protein were obtained using dried seaweed as a heterogeneous nucleating agent. No crystals were obtained in the absence of the heterogeneous nucleating agent. These initial crystals were subsequently used as seeds to produce diffraction-quality crystals. The crystals diffracted to 2.03 angstrom resolution and had the symmetry of space group P1. This study demonstrates the utility of heterogeneous nucleation. The solution of the crystal structures will lead to further understanding of Zn2+ acquisition by S. pneumoniae

NASA newsletters for the Weber Student Shuttle Involvement Project

Biweekly reports generated for the Weber Student Shuttle Involvement Project (SSIP) are discussed. The reports document the evolution of science, hardware, and logistics for this Shuttle project aboard the eleventh flight of the Space Transportation System (STS-41B), launched from Kennedy Space Center on February 3, 1984, and returned to KSC 8 days later. The reports were intended to keep all members of the team aware of progress in the project and to avoid redundancy and misunderstanding. Since the Weber SSIP was NASA's first orbital rat project, documentation of all actions was essential to assure the success of this complex project. Eleven reports were generated: October 3, 17 and 31; November 14 and 28; and December 12 and 17, 1983; and January 3, 16, and 23; and May 1, 1984. A subject index of the reports is included. The final report of the project is included as an appendix

Advanced high temperature static strain sensor development

An examination was made into various techniques to be used to measure static strain in gas turbine liners at temperatures up to 1150 K (1600 F). The methods evaluated included thin film and wire resistive devices, optical fibers, surface acoustic waves, the laser speckle technique with a heterodyne readout, optical surface image and reflective approaches and capacitive devices. A preliminary experimental program to develop a thin film capacitive device was dropped because calculations showed that it would be too sensitive to thermal gradients. In a final evaluation program, the laser speckle technique appeared to work well up to 1150 K when it was used through a relatively stagnant air path. The surface guided acoustic wave approach appeared to be interesting but to require too much development effort for the funds available. Efforts to develop a FeCrAl resistive strain gage system were only partially successful and this part of the effort was finally reduced to a characterization study of the properties of the 25 micron diameter FeCrAl (Kanthal A-1) wire. It was concluded that this particular alloy was not suitable for use as the resistive element in a strain gage above about 1000 K

The Role of Mesotocin on Social Bonding in Pinyon Jays

The neuropeptide oxytocin influences mammalian social bonding by facilitating the building and maintenance of parental, sexual, and same‐sex social relationships. However, we do not know whether the function of the avian homologue mesotocin is evolutionarily conserved across birds. While it does influence avian prosocial behavior, mesotocin\u27s role in avian social bonding remains unclear. Here, we investigated whether mesotocin regulates the formation and maintenance of same‐sex social bonding in pinyon jays (Gymnorhinus cyanocephalus), a member of the crow family. We formed squads of four individually housed birds. In the first, “pair‐formation” phase of the experiment, we repeatedly placed pairs of birds from within the squad together in a cage for short periods of time. Prior to entering the cage, we intranasally administered one of three hormone solutions to both members of the pair: mesotocin, oxytocin antagonist, or saline. Pairs received repeated sessions with administration of the same hormone. In the second, “pair‐maintenance” phase of the experiment, all four members of the squad were placed together in a large cage, and no hormones were administered. For both phases, we measured the physical proximity between pairs as our proxy for social bonding. We found that, compared with saline, administering mesotocin or oxytocin antagonist did not result in different proximities in either the pair‐formation or pair‐maintenance phase of the experiment. Therefore, at the dosages and time frames used here, exogenously introduced mesotocin did not influence same‐sex social bond formation or maintenance. Like oxytocin in mammals, mesotocin regulates avian prosocial behavior; however, unlike oxytocin, we do not have evidence that mesotocin regulates social bonds in birds

Exploring barriers to and enablers of adequate healthcare for Indigenous Australian prisoners with cancer: a scoping review drawing on evidence from Australia, Canada and the United States

Published: 3 May 2016Background: International frameworks supported by national principles in Australia stipulate that prisoners should be provided with health services equivalent to those provided in the general community. However, a number of barriers unique to the prison system may hinder the provision of equitable healthcare for this population. In Australia, Indigenous people carry a greater burden of cancer mortality, which the Cancer Data and Aboriginal Disparities (CanDAD) project is seeking to address. During the course of recruiting participants to the CanDAD study, Indigenous Australian prisoners with cancer emerged as an important, under-researched but difficult to access sub-group. Methods: This scoping review sought to identify barriers and facilitators of access to adequate and equitable healthcare for Indigenous Australian prisoners with cancer in Australia. This review demonstrated a lack of research and, as such, the scoping review was extended to prisoners with cancer in Australia, New Zealand, the United States and Canada. This approach was taken in order to summarise the existing body of evidence regarding the barriers and facilitators of access to adequate and equitable healthcare for those who are incarcerated and suffering from cancer, and highlight areas that may require further investigation. Results: Eight studies or commentaries were found to meet the inclusion criteria. This limited set of findings pointed to a range of possible barriers faced by prisoners with cancer, including a tension between the prisons’ concern with security versus the need for timely access to medical care. Conclusion: Findings identified here offer potential starting points for research and policy development. Further research is needed to better elucidate how barriers to adequate cancer care for prisoners may be identified and overcome, in Australia and internationally. Furthermore, given Indigenous Australians’ over-burden of cancer mortality and over-representation in the prison system, further research is needed to identify whether there are a unique set of barriers for this group.Jessica Olds, Rachel Reilly, Paul Yerrell, Janet Stajic, Jasmine Micklem, Kim Morey and Alex Brow

Combination high-speed, natural-air corn drying

1 online resource (PDF, 8 pages)This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu

Incommensurate magnetism near quantum criticality in CeNiAsO

Two phase transitions in the tetragonal strongly correlated electron system CeNiAsO were probed by neutron scattering and zero field muon spin rotation. For $T <T_{N1}$ = 8.7(3) K, a second order phase transition yields an incommensurate spin density wave with wave vector $\textbf{k} = (0.44(4), 0, 0)$. For $T < T_{N2}$ = 7.6(3) K, we find co-planar commensurate order with a moment of $0.37(5)~\mu_B$, reduced to $30 \%$ of the saturation moment of the $|\pm\frac{1}{2}\rangle$ Kramers doublet ground state, which we establish by inelastic neutron scattering. Muon spin rotation in $\rm CeNiAs_{1-x}P_xO$ shows the commensurate order only exists for x $\le$ 0.1 so the transition at $x_c$ = 0.4(1) is from an incommensurate longitudinal spin density wave to a paramagnetic Fermi liquid

Integrated cross-domain object storage in working memory: Evidence from a verbal-spatial memory task

Working-memory theories often include domain-specific verbal and visual stores (e.g., the phonological and visuospatial buffers of Baddeley, 1986), and some also posit more general stores thought to be capable of holding verbal or visuospatial materials (Baddeley, 2000; Cowan, 2005). However, it is currently unclear which type of store is primarily responsible for maintaining objects that include components from multiple domains. In these studies, a spatial array of letters was followed by a single probe identical to an item in the array or differing systematically in spatial location, letter identity, or their combination. Concurrent verbal rehearsal suppression impaired memory in each of these trial types in a task that required participants to remember verbal-spatial binding, but did not impair memory for spatial locations if the task did not require verbal-spatial binding for a correct response. Thus, spatial information might be stored differently when it must be bound to verbal information. This suggests that a cross-domain store such as the episodic buffer of Baddeley (2000) or the focus of attention of Cowan (2001) might be used for integrated object storage, rather than the maintenance of associations between features stored in separate domain-specific buffers