Modular and Reusable Miniature Subsystems for Small Satellites: An Example Describing Surrey’s Nanosatellite S-Band Downlink

For more than a decade, engineers at Surrey and elsewhere have been advocating a modular approach to satellite engineering, and demonstrating this approach with practical missions. The electro-mechanical modularity pioneered by Surrey and AMSAT on their microsatellites has been emulated by many groups building satellites in the faster, better, cheaper paradigm. Paradoxically, the technique is now being applied to both larger satellites (minisatellites) and smaller satellites (nanosatellites). Simultaneously, the underlying technology is advancing and functional density is increasing rapidly. The standard 330 x 330 x 30 mm module characteristic of Surrey’s early satellites is inappropriate both for nanosatellites and for the increasingly dense electronics now available. As part of the Surrey Nanosatellite Applications Program (SNAP), we have investigated a smaller, more modern modular unit based on the “Eurocard” standard. This paper describes the new modular approach, and some of the subsystem functions which can now be embedded in the 120 x 160 x 20 mm unit. Using modules based on the in-house SNAP standard, Surrey can now design minisatellites, microsatellites and nanosatellites sharing common subsystem designs where appropriate. This updated modular approach still confers benefits in flight heritage, technology insertion, redundancy, system design and analysis and manufacturing

Introduction to the issue on novel and specialty fibers

The fiber optical communication revolution has been fueled by well publicized and relentless improvements of transmission fiber. Since the demonstration of the first low-loss optical fiber in 1972, there has been a continual stream of technology improvements designed to reduce impairments due to propagation loss and pulse dispersion. This steam of fiber technology has led the industry from multimode fiber operated at 800 nm, to standard single-mode fiber used at 1310 nm, then on to transmission fibers that now have attributes tuned for particular applications such as terrestrial or submarine transmission. There is every reason to believe that advances in technology will continue at the accelerating pace we have seen in the past decade, adding to the family of available transmission fibers. The special issue is dedicated to the increasing family of specialty fibers, and includes exciting papers on fibers for gratings and a unique amplification fiber. Fibers for specialized transmission spanning a broad range of applications are also described in three important articles. As is appreciated by all optical scientists, progress can be made only as quickly as one can improve measurement capabilities, so the issue includes two excellent papers dealing with the important measurement of chromatic dispersion.We hope that you enjoy the papers of this issue as much as we the editors have enjoyed reading and reviewing them

Sports Participation in Youth with Inflammatory Bowel Diseases: The Role of Disease Activity and Subjective Physical Health Symptoms

Background: Physical activity is important for youth with inflammatory bowel diseases (IBD), and sports participation is a common way in which youth are physically active. Yet, studies examining sports participation in youth with IBD and barriers to sports participation are lacking. This study examined the role of disease complications, body mass index (BMI), subjective physical health, and psychosocial functioning in influencing sports participation in a large sample of youth with IBD participating in the Crohn's and Colitis Foundation of America Partners (CCFA Partners) Kids and Teens Registry. Methods: CCFA Partners Kids and Teens is an internet-based cohort study in which participants and their parents self-report demographics, disease characteristics, anthropometrics, and validated assessments of physical health, psychosocial functioning, and perceived impairment in sports participation. We performed a cross-sectional analysis of 450 cohort participants, age 12-17 years. Results: Nearly two-thirds of the sample reported that their IBD resulted in some impairment in sports participation. IBD disease activity was associated with perceived impairment in sports participation. In a forward regression analysis controlling for disease activity, fatigue, pain, and past IBD-related surgery emerged as the most salient correlates of impairment in sports participation. Conclusions: Disease activity and subjective physical health symptoms were the most salient correlates of impairment in sports participation. Whether these barriers interfere with physical activity more generally deserves further study, as does replication of these findings longitudinally. Ultimately, a greater understanding of potential barriers to sports participation may be useful for generating targeted physical activity recommendations for youth with IBD

Shared Care, Elder and Family Member Skills Used to Manage Burden

Aim. The aim of this paper is to further develop the construct of Shared Care by comparing and contrasting it to related research, and to show how the construct can be used to guide research and practice. Background. While researchers have identified negative outcomes for family caregivers caused by providing care, less is known about positive aspects of family care for both members of a family dyad. Understanding family care relationships is important to nurses because family participation in the care of chronically ill elders is necessary to achieve optimal outcomes from nursing interventions. A previous naturalistic inquiry identified a new construct, Shared Care, which was used to describe a family care interaction that contributed to positive care outcomes. Methods. A literature review was carried out using the databases Medline, CINAHL, and Psych-info and the keywords home care, care receiver, disability, family, communication, decision-making and reciprocity. The results of the review were integrated to suggest how Shared Care could be used to study care difficulties and guide interventions. Results. The literature confirmed the importance of dyad relationships in family care. Shared Care extended previous conceptualizations of family care by capturing three critical components: communication, decision-making, and reciprocity. Shared Care provides a structure to expand the conceptualization of family care to include both members of a care dyad and account for positive and negative aspects of care. Conclusions. The extended view provided by the construct of Shared Care offers practitioners and scholars tools to use in the context of our ageing population to improve the effectiveness of family care relationships

A mitochondrial half-size ABC transporter is involved in cadmium tolerance in Chlamydomonas reinhardtii

Five cadmium-sensitive insertional mutants, all affected at the CDS1 ('cadmium-sensitive 1') locus, have been previously isolated in the unicellular green alga Chlamydomonas reinhardtii. We here describe the cloning of the Cds1 gene (8314 bp with 26 introns) and the corresponding cDNA. The Cds1 gene, strongly induced by cadmium, encodes a putative protein (CrCds1) of 1062 amino acid residues that belongs to the ATM/HMT subfamily of half-size ABC transporters. This subfamily includes both vacuolar HMT-type proteins transporting phytochelatin-cadmium complexes from the cytoplasm to the vacuole and mitochondrial ATM-type proteins involved in the maturation of cytosolic Fe/S proteins. Unlike the Delta sphmt1 cadmium-sensitive mutant of Schizosaccharomyces pombe that lacks a vacuolar HMT-type transporter, the cds1 mutant accumulates a high amount of phytochelatin-cadmium complexes. By epitope tagging, the CrCds1 protein was localized in the mitochondria. Even though mitochondria of cds1 do not accumulate important amounts of 'free' iron, the mutant cells are hypersensitive to high iron concentrations. Our data show for the first time that a mitochondrial ATM-like transporter plays a major role in tolerance to cadmium.Peer reviewe

Imaging of Spin Dynamics in Closure Domain and Vortex Structures

Time-resolved Kerr microscopy is used to study the excitations of individual micron- scale ferromagnetic thin film elements in their remnant state. Thin (18 nm) square elements with edge dimensions between 1 and 10 $\mu$m form closure domain structures with 90 degree Neel walls between domains. We identify two classes of excitations in these systems. The first corresponds to precession of the magnetization about the local demagnetizing field in each quadrant, while the second excitation is localized in the domain walls. Two modes are also identified in ferromagnetic disks with thicknesses of 60 nm and diameters from 2 $\mu$m down to 500 nm. The equilibrium state of each disk is a vortex with a singularity at the center. As in the squares, the higher frequency mode is due to precession about the internal field, but in this case the lower frequency mode corresponds to gyrotropic motion of the entire vortex. These results demonstrate clearly the existence of well-defined excitations in inhomogeneously magnetized microstructures.Comment: PDF File (Figures at reduced resolution

Hydroethanolic Allium sativum extract accelerates excision wound healing: evidence for roles of mast-cell infiltration and intracytoplasmic carbohydrate ratio

ABSTRACT The present study was designed to evaluate the in vivo effect of Allium sativum (garlic) hydroalcoholic extract on wound healing in rats. For this purpose, 72 mature Wistar rats were divided into four groups (n=18/each) to receive no treatment, placebo, Cicalfate(r), or 2% Allium sativum (AS) extract, administered topically to the wound area, for 21 days. Following the experimental period, tissue samples were dissected out and underwent to histopathological analyses. Fibroblasts, fibrocytes, mast cells, intra-cytoplasmic carbohydrate ratio, neovascularization, collagen deposition, and re-epithelialization were analyzed in all groups. Animals in the treated groups showed significant enhancement in fibroblast, fibrocyte, and mast-cell distribution. Significantly higher neovascularization was observed on day 3 after wound induction in AS-treated animals versus those in the placebo, Cicalfate, and untreated groups (P<0.05). A dose-dependent, significantly higher intra-cytoplasmic carbohydrate storage was observed in treated animals. Our data show that AS promotes wound healing due to its preliminary impact on mast-cell distribution, which enhanced collagen synthesis and upregulated angiogenesis, and shortened the healing process by enhancing the intra-cytoplasmic carbohydrate ratio

Peer support opportunities across the cancer care continuum: a systematic scoping review of recent peer-reviewed literature

Objective: Evidence suggests peer support (PS) is as an effective strategy for enhancing prevention and control of chronic and infectious diseases, including cancer. This systematic scoping review examines the range and variety of interventions on the use of PS across the cancer care continuum. Method: We used a broad definition of PS to capture a wide-range of interventions and characterize the current status of the field. Literature searches were conducted using PubMed, SCOPUS, and CINAHL to identify relevant articles published from January 2011 to June 2016. We screened the title and abstracts of 2087 articles, followed by full-text screening of 420 articles, resulting in a final sample of 242 articles of which the most recent 100 articles were reviewed (published June 2014 to May 2016). Results: A number of the recent intervention studies focused on breast cancer (32%, breast cancer only) or multiple cancer sites (23%). Although the interventions spanned all phases of the cancer care continuum, only 2% targeted end-of-life care. Seventy-six percent focused on clinical outcomes (e.g., screening, treatment adherence) and 72% on reducing health disparities. Interventions were primarily phone-based (44%) or delivered in a clinic setting (44%). Only a few studies (22%) described the impact of providing PS on peer supporters. Conclusion: PS appears to be a widely used approach to address needs across the cancer care continuum, with many opportunities to expand its reach

Quantitative importance of staminodes for female reproductive success in Parnassia palustris under contrasting environmental conditions.

The five sterile stamens, or staminodes, in Parnassia palustris act both as false and as true nectaries. They attract pollinators with their conspicuous, but non-rewarding tips, and also produce nectar at the base. We removed staminodes experimentally and compared pollinator visitation rate and duration and seed set in flowers with and without staminodes in two different populations. We also examined the relative importance of the staminode size to other plant traits. Finally, we bagged, emasculated, and supplementary cross-pollinated flowers to determine the pollination strategy and whether reproduction was limited by pollen availability. Flowers in both populations were highly dependent on pollinator visitation for maximum seed set. In one population pollinators primarily cross-pollinated flowers, whereas in the other the pollinators facilitated self-pollination. The staminodes caused increased pollinator visitation rate and duration to flowers in both populations. The staminodes increased female reproductive success, but only when pollen availability constrained female reproduction. Simple linear regression indicated a strong selection on staminode size, multiple regression suggested that selection on staminode size was mainly caused by correlation with other traits that affected female fitness. [ABSTRACT FROM AUTHOR