Space-based geoengineering: challenges and requirements

The prospect of engineering the Earth's climate (geoengineering) raises a multitude of issues associated with climatology, engineering on macroscopic scales, and indeed the ethics of such ventures. Depending on personal views, such large-scale engineering is either an obvious necessity for the deep future, or yet another example of human conceit. In this article a simple climate model will be used to estimate requirements for engineering the Earth's climate, principally using space-based geoengineering. Active cooling of the climate to mitigate anthropogenic climate change due to a doubling of the carbon dioxide concentration in the Earth's atmosphere is considered. This representative scenario will allow the scale of the engineering challenge to be determined. It will be argued that simple occulting discs at the interior Lagrange point may represent a less complex solution than concepts for highly engineered refracting discs proposed recently. While engineering on macroscopic scales can appear formidable, emerging capabilities may allow such ventures to be seriously considered in the long term. This article is not an exhaustive review of geoengineering, but aims to provide a foretaste of the future opportunities, challenges, and requirements for space-based geoengineering ventures

Moving Beyond Lip Service: The Clinical Reasoning Behind Practicing Strengths

Social work has a long tradition of advocating for practice from the strengths perspective. However, it is unclear whether schools are truly preparing students for strengths based practice or whether they are simply teaching them to use the vocabulary of strengths without the clinical reasoning skills to switch paradigms from deficits to strengths, moving beyond lip service to real strengths-based practice. To explore this issue, data from an exercise in an MSW course was explored using qualitative methodology. The findings support that in addition to using a strengths vocabulary, other components are necessary for true implementation of a strengths approach. First, the data revealed a strengths-oriented structural model of an ideal process of clinical reasoning for approaching a client situation. Second, the process includes recognizing client strengths, reflecting on them with the client, and encouraging repetition and reinforcement of the client’s positive attitudes and actions. Finally, true strengths based understanding requires moving from social worker in the role of expert to social worker engaged in collaborative empowerment practice. These findings have implications for social work practice and education

Cumulative and Differential Effects of Early Child Care and Middle Childhood Out-of-School Time on Adolescent Functioning.

Effects associated with early child care and out-of-school time (OST) during middle childhood were examined in a large sample of U.S. adolescents (N = 958). Both higher quality early child care AND more epochs of organized activities (afterschool programs and extracurricular activities) during middle childhood were linked to higher academic achievement at age 15. Differential associations were found in the behavioral domain. Higher quality early child care was associated with fewer externalizing problems, whereas more hours of early child care was linked to greater impulsivity. More epochs of organized activities was associated with greater social confidence. Relations between early child care and adolescent outcomes were not mediated or moderated by OST arrangements in middle childhood, consistent with independent, additive relations of these nonfamilial settings

Survival and Response Molting of Mud Crab (Scylla Olivacea) Injected with Murbey (Morus Spp.) Leave Extract

The soft shell crab productivity has been hampered due to the long rearing time and unsimultaneous molting of the crab. This study aimed to determine the effect of murbey (Morus spp.) leave extract as molting stimulant on Scylla olivacea and its best extract dosage to be applied in soft shell crabs production technology. Application of murbey extract was conducted by using injection method with 5 treatments such as (a) 0 ppm (as control); (b) 100 ppm; (c) 125 ppm; and (d) 150 ppm for 12 individual per treatment. The results showed that the highest molting percentage (50%) was obtained at the concentration of 100 ppm. Meanwhile, the control (0 ppm), 125 ppm, and 150 ppm treatments displayed the same molting response (33.3%). The fastest latent molting time (29 days) was found at the treatment of 125 ppm and the slowest one of 44 days at 100 and 150 ppm treatments. The best growth of crabs injected with murbey leaves extract was at the concentration of 100 ppm with the carapace width of 6.0 mm and the body weight of 32.98 g, while the lowest was obtained at the concentration of 150 ppm with the carapace width of 3.8 mm and the body weight of 25.43 g. Crabs treated with murbey extract at the concentrations of 100, 125, and 150 ppm exhibited survival rate of 91.7 % vs. the control of 83.3%. Murbey leaves extract have been proven to be effective in stimulating molting mud crab (Scylla olivacea). The 100 ppm exhibited the best response for growth and molting percentage, while the 125 ppm showed the best performance for latent period molting of the crab

Optical Relay for Future NASA Geosynchronous Orbiting Satellite for High Data Rate Links to NASA User Missions

NASA is exploring options for its Next Generation Relay (NGR) architecture while the current Tracking Data Relay Satellite System (TDRSS) completes its mission. The plan is to start implementation of the NGR beginning around 2025. The new system of proposed relay satellites will greatly increase the data rates between low Earth orbiting (LEO) satellite missions and the NASA TDRSS relay satellites. This increase in data rates will allow an unprecedented increase in data throughput from the LEO satellite missions back to the principal investigators (PI). This can be accomplished at Ka-band frequencies with high order modulation or at optical frequencies using Differential Phase Shift Keying (DPSK). The first satellite in the next set of relay satellites will have to be backward compatible with current technology to support ongoing and planned missions. The new set of satellites will be launched over a 10-year period with design lifetimes of at least 15 years. To meet these requirements, we analyzed various architectures and designed both the communication payloads on the relay satellite and candidate payloads on the user spacecraft by utilizing optical heads already designed. From this analysis, a demonstration optical satellite named the Next Generation Optical Relay Pathfinder with Ka-band capabilities was proposed to be built and launched with the purpose of evaluating an integrated high-speed optical and Ka-band communication system. Given a cost limit for the demonstration satellite, various satellite configurations were developed by varying the number of optical communication payloads. The communication payload on the relay satellite consisted of three major sub-systems: 1) Optical communication payload, 2) Ka-band communication payload, 3) Digital processing and routing of signals. The size, mass (weight), and power (SWaP) of the communication payload and other sub-systems of the satellite were obtained. The NASA Glenn Research Center COMPASS team designed the Pathfinder satellite and performed a cost analysis for its build and launch. In this paper, we first describe the needs, drivers, and the associated challenges for the Next Generation Optical Relay Pathfinder to be capable of connecting multiple LEO and GEO satellites at high data rates. Second, we detail the concept of operations (ConOps) and the system architecture, including the satellite configurations considered, their attributes and limitations, and the size of the satellite needed for each configuration. Third, we provide a summary of the Next Generation Optical Relay Pathfinder satellite design trades and its key elements. Finally, we present the path needed for implementation and operations

Properties of HxTaS2

The preparation of Hx TaS2 (0 \u3c x \u3c 0.87) is described. The compounds are only marginally stable at room temperature, slowly evolving H2S and H2 (and possibly Hp in air). Magnetic susceptibility data show that a low temperature transformation in 2H ... TaS2 (at so•K) is suppressed with the addition of hydrogen, and· at the same time the superconducting transition temperature T c rises from 0.8 to ~4.2•K at x = 0.11. Heat capacity measurements near this concentration show the superconductivity to be a bulk effect. Finally, by correlation of this data with susceptibility and T c measurements in other intercalation compounds, we suggest that the rise of T c (at low electron transfer) is due to suppression of the low temperature transformation and not due to an excitonic mechanism of superconductivity

Socioeconomic risk, parenting during the preschool years and child health age 6 years

Parent–child relationships and parenting processes are emerging as potential life course determinants of health. Parenting is socially patterned and could be one of the factors responsible for the negative effects of social inequalities on health, both in childhood and adulthood. This study tests the hypothesis that some of the effect of socioeconomic risk on health in mid childhood is transmitted via early parenting. Methods: Prospective cohort study in 10 USA communities involving 1041 mother/ child pairs, selected at birth at random with conditional sampling. Exposures: income, maternal education, maternal age, lone parenthood, ethnic status and objective assessments of mother child interaction in the first 4 years of life covering warmth, negativity and positive control. Outcomes: mother’s report of child’s health in general at 6 years. Modelling: multiple regression analyses with statistical testing of mediational processes. Results: All five indicators of socioeconomic status (SES) were correlated with all three measures of parenting, such that low SES was associated with poor parenting. Among the measures of parenting maternal warmth was independently predictive of future health, and among the socioeconomic variables maternal education, partner presence and ‘other ethnic group’ proved predictive. Measures of parenting significantly mediated the impact of measures of SES on child health. Conclusions: Parenting mediates some, but not all of the detectable effects of socioeconomic risk on health in childhood. As part of a package of measures that address other determinants, interventions to support parenting are likely to make a useful contribution to reducing childhood inequalities in health

Subharmonic Shapiro steps and assisted tunneling in superconducting point contacts

We analyze the current in a superconducting point contact of arbitrary transmission in the presence of a microwave radiation. The interplay between the ac Josephson current and the microwave signal gives rise to Shapiro steps at voltages V = (m/n) \hbar \omega_r/2e, where n,m are integer numbers and \omega_r is the radiation frequency. The subharmonic steps (n different from 1) are a consequence of the ocurrence of multiple Andreev reflections (MAR) and provide an unambiguous signature of the peculiar ac Josephson effect at high transmission. Moreover, the dc current exhibits a rich subgap structure due to photon-assisted MARs.Comment: Revtex, 4 pages, 4 figure