A high-rate telemetry system for the Mariner Mars 1969 mission

High rate telemetry system for Mariner Mars 1969 missio

An approach to the preliminary evaluation of Closed Ecological Life Support System (CELSS) scenarios and control strategies

Life support systems for manned space missions are discussed. A scenario analysis method was proposed for the initial step of comparing possible partial or total recycle scenarios. The method is discussed in detail

Ccdc11 is a novel centriolar satellite protein essential for ciliogenesis and establishment of left-right asymmetry

The establishment of left–right (L-R) asymmetry in vertebrates is dependent on the sensory and motile functions of cilia during embryogenesis. Mutations in CCDC11 disrupt L-R asymmetry and cause congenital heart disease in humans, yet the molecular and cellular functions of the protein remain unknown. Here we demonstrate that Ccdc11 is a novel component of centriolar satellites—cytoplasmic granules that serve as recruitment sites for proteins destined for the centrosome and cilium. Ccdc11 interacts with core components of satellites, and its loss disrupts the subcellular organization of satellite proteins and perturbs primary cilium assembly. Ccdc11 colocalizes with satellite proteins in human multiciliated tracheal epithelia, and its loss inhibits motile ciliogenesis. Similarly, depletion of CCDC11 in Xenopus embryos causes defective assembly and motility of cilia in multiciliated epidermal cells. To determine the role of CCDC11 during vertebrate development, we generated mutant alleles in zebrafish. Loss of CCDC11 leads to defective ciliogenesis in the pronephros and within the Kupffer’s vesicle and results in aberrant L-R axis determination. Our results highlight a critical role for Ccdc11 in the assembly and function of motile cilia and implicate centriolar satellite–associated proteins as a new class of proteins in the pathology of L-R patterning and congenital heart disease

Telecommunications systems design techniques handbook

Handbook presents design and analysis of tracking, telemetry, and command functions utilized in these systems with particular emphasis on deep-space telecommunications. Antenna requirements are also discussed. Handbook provides number of tables outlining various performance criteria. Block diagrams and performance charts are also presented

Accessory Mineral Eu Anomalies in Suprasolidus Rocks: Beyond Feldspar

Accessory mineral Eu anomalies (Eu/Eu*) are routinely measured to infer changes in the amount of feldspar over time, allowing accessory mineral U‐Pb dates to be linked to the progressive crystallization of igneous and metamorphic rocks and, by extension, geodynamic processes. However, changes in Eu/Eu* can reflect any process that changes the relative availability of Eu2+ and Eu3+. We constructed partitioning budgets for Sm, Eu2+, Eu3+, and Gd in suprasolidus metasedimentary rocks to investigate processes that can influence accessory mineral Eu anomalies. We modeled three scenarios: (1) closed‐system, equilibrium crystallization; (2) fractionation of Eu by feldspar growth during melt crystallization; and (3) removal of Eu by melt extraction. In the closed‐system equilibrium model, accessory mineral Eu/Eu* changes as a function of fO2 and monazite stability; Eu/Eu* changes up to 0.3 over a pressure‐temperature range of 4–12 kbar and 700–950°C. Fractionation of Eu by feldspar growth is modeled to decrease accessory mineral Eu/Eu* by ~0.05–0.15 per 10 wt% feldspar crystallized. Melt extraction has a smaller effect; removal of 10% melt decreases accessory mineral Eu/Eu* in the residue by ≤0.05. Although these models demonstrate that fractionation of Eu by feldspar growth can be a dominant control on a rocks u budget, they also show that the common interpretation that Eu/Eu* only records feldspar growth and breakdown is an oversimplification that could lead to incorrect interpretation about the duration and rates of tectonic processes. Consideration of other processes that influence Eu anomalies will allow for a broader range of geological processes to be investigated by petrochronology.Plain Language SummaryMetamorphic rocks—rocks in which new minerals grew in response to increase in pressure and temperature related to deep burial or subduction—and igneous rocks—rocks that formed as magmas cool and crystallize—provide a direct record of how Earth’s continents have moved and changed through time. To read this record, geologists need to be able to measure the ages of metamorphism and magmatism: When did it happen? How long did it last? How does it relate to other rocks around the world? A common approach to addressing these questions is using U‐Pb dating of the minerals zircon, monazite, and apatite. The elements these minerals incorporate are indicative of how hot and how deep in the Earth they were when they grew. In this study we explore how geologists can use the concentrations of the element Europium (Eu) in these minerals to provide new insights into the geological meaning of U‐Pb dates, leading to more robust interpretations of Earth’s plate tectonic history.Key PointsEu anomalies in suprasolidus rocks record any process that changes the relative availability of Eu2+ and Eu3+, not just feldspar growthDisequilibrium is required for feldspar growth to strongly influence accessory mineral Eu anomaliesComparing accessory mineral Eu anomalies and Sr concentrations leads to more robust interpretation than evaluating Eu anomalies alonePeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156481/1/ggge22268_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156481/3/ggge22268.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156481/2/ggge22268-sup-0001-2020GC009052-Text_SI-S01.pd

Coupled-channels analysis of the 16^{{\bf 16}}O+208^{{\bf 208}}Pb fusion barrier distribution

Analyses using simplified coupled-channels models have been unable to describe the shape of the previously measured fusion barrier distribution for the doubly magic $^{16}$O+$^{208}$Pb system. This problem was investigated by re-measuring the fission excitation function for $^{16}$O+$^{208}$Pb with improved accuracy and performing more exact coupled-channels calculations, avoiding the constant-coupling and first-order coupling approximations often used in simplified analyses. Couplings to the single- and 2-phonon states of $^{208}$Pb, correctly taking into account the excitation energy and the phonon character of these states, particle transfers, and the effects of varying the diffuseness of the nuclear potential, were all explored. However, in contrast to other recent analyses of precise fusion data, no satisfactory simultaneous description of the shape of the experimental barrier distribution and the fusion cross-sections for $^{16}$O+$^{208}$Pb was obtained.Comment: RevTex, 29 pages, 7 postscript figures, to appear in PR

Kleptoparasitic melees--modelling food stealing featuring contests with multiple individuals

Kleptoparasitism is the stealing of food by one animal from another. This has been modelled in various ways before, but all previous models have only allowed contests between two individuals. We investigate a model of kleptoparasitism where individuals are allowed to fight in groups of more than two, as often occurs in real populations. We find the equilibrium distribution of the population amongst various behavioural states, conditional upon the strategies played and environmental parameters, and then find evolutionarily stable challenging strategies. We find that there is always at least one ESS, but sometimes there are two or more, and discuss the circumstances when particular ESSs occur, and when there are likely to be multiple ESSs

Shear Heating Reconciles Thermal Models with the Metamorphic Rock Record of Subduction

Some commonly referenced thermal-mechanical models of current subduction zones imply temperatures that are 100–500 °C colder at 30–80-km depth than pressure–temperature conditions determined thermobarometrically from exhumed metamorphic rocks. Accurately inferring subduction zone thermal structure, whether from models or rocks, is crucial for predicting metamorphic reactions and associated fluid release, subarc melting conditions, rheologies, and fault-slip phenomena. Here, we compile surface heat flow data from subduction zones worldwide and show that values are higher than can be explained for a frictionless subduction interface often assumed for modeling. An additional heat source––likely shear heating––is required to explain these forearc heat flow values. A friction coefficient of at least 0.03 and possibly as high as 0.1 in some cases explains these data, and we recommend a provisional average value of 0.05 ± 0.015 for modeling. Even small coefficients of friction can contribute several hundred degrees of heating at depths of 30–80 km. Adding such shear stresses to thermal models quantitatively reproduces the pressure–temperature conditions recorded by exhumed metamorphic rocks. Comparatively higher temperatures generally drive rock dehydration and densification, so, at a given depth, hotter rocks are denser than colder rocks, and harder to exhume through buoyancy mechanisms. Consequently––conversely to previous proposals––exhumed metamorphic rocks might overrepresent old-cold subduction where rocks at the slab interface are wetter and more buoyant than in young-hot subduction zones

Dietary assessment of British police force employees: A description of diet record coding procedures and cross-sectional evaluation of dietary energy intake reporting (The Airwave Health Monitoring Study)

Objectives: Dietary intake is a key aspect of occupational health. To capture the characteristics of dietary behaviour that is affected by occupational environment that may affect disease risk, a collection of prospective multiday dietary records is required. The aims of this paper are to: (1) collect multiday dietary data in the Airwave Health Monitoring Study, (2) describe the di etary coding procedures applied and (3) investigate the plausibility of dietary reporting in this occupational cohort. Design: A dietary coding protocol for this large-scale study was developed to minimise coding error rate. Participants (n 4412) who completed 7-day food records were included for cross-sectional analyses. Energy intake (EI) misreporting was estimated using the Goldberg method. Multivariate logistic regression models were applied to determine participant characteristics associated with EI misreporting. Setting: British police force employees enrolled (2007-2012) into the Airwave Health Monitoring Study. Results: The mean code error rate per food diary was 3.7% (SD 3.2%). The strongest predictors of EI under-reporting were body mass index (BMI) and physical activity. Compared with participants with BMI 30 kg/m2 had increased odds of being classified as under-reporting EI (men OR 5.20 95% CI 3.92 to 6.89; women OR 2.66 95% CI 1.85 to 3.83). Men and women in the highest physical activity category compared with the lowest were also more likely to be classified as underreporting (men OR 3.33 95% CI 2.46 to 4.50; women OR 4.34 95% CI 2.91 to 6.55). Conclusions: A reproducible dietary record coding procedure has been developed to minimise coding error in complex 7-day diet diaries. The prevalence of EI under-reporting is comparable with existing national UK cohorts and, in agreement with previous studies, classification of under-reporting was biased towards specific subgroups of participants