Report of the x ray and gamma ray sensors panel

Overall five major areas of technology are recommended for development in order to meet the science requirements of the Astrotech 21 mission set. These are: detectors for high resolution gamma ray spectroscopy, cryogenic detectors for improved x ray spectral and spatial resolution, advanced x ray charge coupled devices (CCDs) for higher energy resolution and larger format, extension to higher energies, liquid and solid position sensitive detectors for improving stopping power in the energy range 5 to 500 keV and 0.2 to 2 MeV. Development plans designed to achieve the desired capabilities on the time scales required by the technology freeze dates have been recommended in each of these areas

Sources of Nutrition Information in Recreational Ultra-marathon Runners: A Mixed Methods Analysis

Ultra-marathon events (i.e., .42.2-km) continue to grow in popularity; however, little is known regarding the sources of nutrition information which inform their beliefs and habits. The objective of this study was to characterize the acquisition of sport-specific nutrition information among ultra-endurance athletes using a mixed methods design. Qualitative data were collected through focus groups and analyzed using thematic analysis. Three primary higher order themes were identified: Optimal Diet for Ultra-Endurance Athletes, Common Sources of Information, and Barriers to Scientific Information. Then, a self-report inventory (Sources of Nutrition Information-SONI questionnaire) was developed to assess common sources of nutrition information and characterize their beliefs about those sources. Likert-type questions were used, and primary sources were scored out of 3, sub-questions out of 5. Differences between sources were assessed using RM-ANOVA. Participants (N = 224) accessed, responded to, and submitted the survey via a secure, study-specific web-based link. Peer reviewed literature was reported as the most frequently used (mean score = 1.64, p \u3c 0.001), credible (3.02, p \u3c 0.001), and interesting (2.62, p \u3c 0.002). Social media was the most accessible (2.81, p \u3c 0.001), but the least credible (1.87, p \u3c 0.001). While social media was perceived less credible than other sources, its accessibility could make it a promising tool to provide evidence-based nutrition information to this population

Palmitoylation of Desmoglein 2 Is a Regulator of Assembly Dynamics and Protein Turnover.

Desmosomes are prominent adhesive junctions present between many epithelial cells as well as cardiomyocytes. The mechanisms controlling desmosome assembly and remodeling in epithelial and cardiac tissue are poorly understood. We recently identified protein palmitoylation as a mechanism regulating desmosome dynamics. In this study, we have focused on the palmitoylation of the desmosomal cadherin desmoglein-2 (Dsg2) and characterized the role that palmitoylation of Dsg2 plays in its localization and stability in cultured cells. We identified two cysteine residues in the juxtamembrane (intracellular anchor) domain of Dsg2 that, when mutated, eliminate its palmitoylation. These cysteine residues are conserved in all four desmoglein family members. Although mutant Dsg2 localizes to endogenous desmosomes, there is a significant delay in its incorporation into junctions, and the mutant is also present in a cytoplasmic pool. Triton X-100 solubility assays demonstrate that mutant Dsg2 is more soluble than wild-type protein. Interestingly, trafficking of the mutant Dsg2 to the cell surface was delayed, and a pool of the non-palmitoylated Dsg2 co-localized with lysosomal markers. Taken together, these data suggest that palmitoylation of Dsg2 regulates protein transport to the plasma membrane. Modulation of the palmitoylation status of desmosomal cadherins can affect desmosome dynamics

Surveying structural complexity in quantum many-body systems

Quantum many-body systems exhibit a rich and diverse range of exotic behaviours, owing to their underlying non-classical structure. These systems present a deep structure beyond those that can be captured by measures of correlation and entanglement alone. Using tools from complexity science, we characterise such structure. We investigate the structural complexities that can be found within the patterns that manifest from the observational data of these systems. In particular, using two prototypical quantum many-body systems as test cases - the one-dimensional quantum Ising and Bose-Hubbard models - we explore how different information-theoretic measures of complexity are able to identify different features of such patterns. This work furthers the understanding of fully-quantum notions of structure and complexity in quantum systems and dynamics.Comment: 9 pages, 5 figure

Integrating Traditional and Scientific Knowledge through Collaborative Natural Science Field Research: Identifying Elements for Success

We discuss two recent projects to examine the role of collaborative environmental fieldwork both in research and in the interactions between academically trained researchers and experienced local residents. The Bidarki Project studied black leather chitons (Katharina tunicata) in the lower Kenai Peninsula, Alaska. Its conclusion that chiton declines are part of a serial decline of intertidal invertebrates drew on collaborative fieldwork, archaeological data, historical records, and interviews with local residents. The Siku-Inuit-Hila Project studied sea ice in Barrow, Alaska; Clyde River, Nunavut; and Qaanaaq, Greenland. Quantitative data from locally maintained observation sites were supplemented by knowledge exchanges among hunters from the communities and by discussion in local working groups to develop an understanding of the physical dynamics and human uses of sea ice at each locale. We conclude that careful planning and preparation, along with the effort to build strong personal relationships, can increase the likelihood that collaborative fieldwork will be productive, enjoyable, and rewarding.Nous discutons de deux récents projets ayant eu pour but d’examiner le rôle d’études environnementales collaboratives sur le terrain, tant sur le plan de la recherche que sur le plan des interactions entre les chercheurs universitaires et les résidents expérimentés des localités visées. Le projet Bidarki se penchait sur les chitons noirs (Katharina tunicata) de la basse péninsule Kenai, en Alaska. La conclusion selon laquelle le déclin des chitons fait partie d’un déclin en série d’invertébrés intertidaux s’appuie sur des études collaboratives sur le terrain, sur des données archéologiques, sur des dossiers historiques ainsi que sur des entrevues de résidents des localités. Pour sa part, le projet Siku-Inuit-Hila a eu comme objectif d’étudier la glace de mer à Barrow, en Alaska; à Clyde River, au Nunavut; et à Qaanaaq, au Groenland. Les données quantitatives provenant de lieux d’observation entretenus localement ont été supplémentées par les échanges de connaissances des chasseurs des collectivités et par les discussions de groupes de travail locaux visant à mieux comprendre la dynamique physique et l’utilisation humaine de la glace de mer à chaque endroit. Nous en concluons que des travaux de planification et de préparation attentionnés, accompagnés d’efforts visant à nouer des liens personnels étroits, peuvent accroître la possibilité que les études collaboratives sur le terrain soient productives, agréables et valorisantes

Sea-Ice Distribution in the Bering and Chukchi Seas: Information from Historical Whaleships’ Logbooks and Journals

Satellite data have revealed dramatic losses of Northern Hemisphere sea ice since the end of the 1970s. To place these changes in a longer-term context, we draw on daily observations taken from logbooks and journals of whaling vessels cruising in the Bering and Chukchi seas to investigate sea-ice conditions in this region of the Arctic between 1850 and 1910. We compare these observations to sea-ice data from 1972 to 1982, which predate the majority of the recent changes and cover a period recognized as a relative maximum in recent Bering Sea ice extent. Records from May indicate that end-of-winter sea-ice extent in the Bering Sea during the mid 19th century closely resembled that in the 1972 – 82 data. However, the historical data reveal that sea ice was more extensive during summer, with the greatest difference occurring in July. This pattern indicates a later and more rapid seasonal retreat. These conclusions highlight the value of historical data, which we have far from exhausted in this study.Des données satellitaires révèlent que l’hémisphère nord a enregistré des pertes dramatiques de glaces de mer depuis la fin des années 1970. Afin de mettre ces changements dans un plus long contexte, nous nous appuyons sur les observations quotidiennes tirées de journaux et de carnets de bord de baleiniers ayant parcouru la mer de Béring et la mer des Tchouktches dans le but d’étudier les glaces de mer de cette région de l’Arctique entre les années 1850 et 1910. Nous comparons ces observations aux données sur les glaces de mer recueillies de 1972 à 1982 – soit avant que la plupart des récents changements n’aient été enregistrés – ce qui couvre une période reconnue comme un maximum relatif en matière d’étendue récente des glaces dans la mer de Béring. Les données enregistrées en mai laissent entrevoir que l’étendue des glaces de mer en fin d’hiver dans la mer de Béring au milieu du XIXe siècle ressemblait beaucoup à l’étendue des glaces dont témoignent les données prélevées entre 1972 et 1982. Cependant, les données historiques révèlent que les glaces de mer étaient plus considérables au cours de l’été, la plus grande différence se manifestant au mois de juillet. Cette tendance indique donc un retrait saisonnier plus tardif et plus rapide. Les conclusions mettent en évidence l’importance des données historiques, que nous sommes loin d’avoir épuisées dans le cadre de cette étude

Synthesis and Catalytic Activity of (3,4-Diphenylcyclopentadienone)Iron Tricarbonyl Compounds in Transfer Hydrogenations and Dehydrogenations

Four (3,4-diphenylcyclopentadienone)iron tricarbonyl compounds were synthesized, and their activities in transfer hydrogenations of carbonyl compounds and transfer dehydrogenations of alcohols were explored and compared to those of the well-established [2,5-(SiMe3)2-3,4-(CH2)4(η4-C4C═O)]Fe(CO)3 (3). A new compound, [2,5-bis(3,5-dimethylphenyl)-3,4-diphenylcyclopentadienone]iron tricarbonyl (7), was the most active catalyst in both transfer hydrogenations and dehydrogenations, and compound 3 was the least active catalyst in transfer hydrogenations. Evidence was found for product inhibition of both 3 and 7 in a transfer dehydrogenation reaction, with the activity of 3 being more heavily affected. A monomeric iron hydride derived from 7 was spectroscopically observed during a transfer hydrogenation, and no diiron bridging hydrides were found under reductive or oxidative conditions. Initial results in the transfer hydrogenation of N-benzylideneaniline showed that 3 was a significantly less active catalyst in comparison to the (3,4-diphenylcyclopentadienone)iron tricarbonyl compounds

on Performance

Abstract Ultra-marathons (footraces greater than 42.2 km) are increasing in popularity, however little is known about the habitual dietary intake of these runners. The aim of this investigation was to empirically describe the habitual training diet of ultra-marathon runners and determine if macronutrient intake was associated with 161-km race performance. To assess habitual diet, runners recruited from five 161-km ultra-marathons across the U.S. (N = 47) completed a diet and training questionnaire, and a web-based 24-hour dietary recall on three separate days within 1-4 weeks prior to a 161-km race. Multiple linear regression was used to predict finish time with covariates carbohydrate, fat and protein, expressed relative to body weight (g·kg -1 ) and total intake (% of diet). To determine differences in macronutrient intake between finishers and non-finishers, two-sample t-tests were used. Dietary intake was varied among participants; mean carbohydrate intake (5.19±2.62 g·kg ) predicted finish time (R 2 = 0.232, P =0.036), however fat was the only significant covariate (t = -2.90, P =0.007). Relative macronutrient intake (% of diet) did not predict finish time (R 2 =0.145, P =0.155). No significant differences were found in macronutrient intake between finishers (n=36) and non-finishers (n=11). Habitual dietary fat intake in ultra-marathon runners was a significant predictor of 161-km finish time, regardless of carbohydrate or protein intake. Further investigation is warranted to determine the optimal nutrient intake in ultra-marathon runners to maximize performance

Telomere length associations with cognition depend on Alzheimer's disease biomarkers

Introduction While telomere shortening, a marker of cellular aging, may impact the progression of age‐related neurodegenerative diseases, its association with cognition is unclear, particularly in the context of Alzheimer's disease (AD) pathology. Methods Telomere, cognitive, and CSF data from 482 participants in the AD Neuroimaging Initiative (148 cognitively normal, 283 mild cognitive impairment, 51 AD) was leveraged to assess telomere length associations with cognition (measured by memory and executive function) and interactions with CSF amyloid‐β, tau, and APOE‐ε4. Secondary analyses assessed brain volume and thickness outcomes. Results Longer telomeres at baseline were associated with faster executive function decline. Amyloid‐β and tau interacted with telomere length on cognition, with longer telomeres related to faster decline among biomarker‐positive individuals. Discussion Telomere associations with cognition shift with AD progression, with longer telomeres related to worse outcomes as pathology increases, highlighting the need for further investigation of telomere length along the AD neuropathological cascade