Critical soft landing technology issues for future US space missions

A programmatic need for research and development to support parachute-based landing systems has not existed since the end of the Apollo missions in the mid-1970s. Now, a number of planned space programs require advanced landing capabilities for which the experience and technology base does not currently exist. New requirements for landing on land with controllable, gliding decelerators and for more effective impact attenuation devices justify a renewal of the landing technology development effort that existed during the Mercury, Gemini, and Apollo programs. A study was performed to evaluate the current and projected national capability in landing systems and to identify critical deficiencies in the technology base required to support the Assured Crew Return Vehicle and the Two-Way Manned Transportation System. A technology development program covering eight landing system performance issues is recommended

Minimally invasive reduction and percutaneous fixation versus open reduction and internal fixation for displaced intra-articular calcaneal fractures : a systematic review of the literature

The aim of this article is to systematically identify and analyse research evidence available to compare the outcomes of minimally invasive reduction and percutaneous fixation (MIRPF) versus open reduction and internal fixation (ORIF) for displaced intra-articular calcaneal fractures. Articles from 2000 to 2016 were searched through MEDLINE (PubMed), Cochrane Library, Embase, ScienceDirect, Scopus and ISI Web of Knowledge using Boolean logic and text words. Of the 570 articles identified initially, nine were selected including three randomized controlled trials and six retrospective comparative studies. All nine studies had a total of 1,031 patients with 1,102 displaced intra-articular calcaneal fractures. Mean follow-up was 33 months. Of these, 602 (54.6%) were treated with MIRPF and 500 (45.4%) were treated with ORIF. Overall incidence of wound-related complications in patients treated with MIRPF was 4.3% (0% to 13%) compared with 21.2% (11.7% to 35%) in the ORIF group Functional outcomes were reported to be better in the minimally invasive group in all studies; however, the results did not reach statistical significance in some studies. All the studies had methodological flaws that put them at either ‘unclear’ or ‘high’ risk of bias for multiple domains. Overall quality of the available evidence is poor in support of either surgical technique due to small sample size, flaws in study designs and high risk of bias for various elements. Individual studies have reported minimally invasive techniques to be an effective alternative with lower risk of wound complications and better functional outcomes.</ul

HLA gene expression is altered in whole blood and placenta from women who later developed preeclampsia

Preeclampsia is a multi-system disease that significantly contributes to maternal and fetal morbidity and mortality. In this study, we used a non-biased microarray approach to identify dysregulated genes in maternal whole blood samples which may be associated with the development of preeclampsia. Whole blood samples were obtained at 28 weeks of gestation from 5 women who later developed preeclampsia (cases) and 10 matched women with normotensive pregnancies (controls). Placenta samples were obtained from an independent cohort of 19 women with preeclampsia matched with 19 women with normotensive pregnancies. We studied gene expression profiles using Illumina microarray in blood and validated changes in gene expression in whole blood and placenta tissue by qPCR. We found a transcriptional profile differentiating cases from controls; 236 genes were significantly dysregulated in blood from women who developed preeclampsia. Functional annotation of microarray results indicated that most of the genes found to be dysregulated were involved in inflammatory pathways. Whilst general trends were preserved, only HLA-A was validated in whole blood samples from cases using qPCR (2.30 ± 0.9 fold change) whereas in placental tissue HLA-DRB1 expression was found to be significantly increased in samples from women with preeclampsia (5.88 ± 2.24 fold change). We have identified that HLA-A is up-regulated in the circulation of women who went on to develop preeclampsia. In placenta of women with preeclampsia we identified that HLA-DRB1 is up-regulated. Our data provide further evidence for involvement of the HLA gene family in the pathogenesis of preeclampsia

Pitfalls in the use of the lung colony assay to assess T-cell function in irradiated mice.

Mice depleted of T lymphocytes by thymectomy, whole-body irradiation and bone-marrow reconstitution showed a marked increase in susceptibility to the development of lung colonies after i.v. injection of cells of an immunogenic fibrosarcoma. However, a similar increase was observed in unthymectomized, irradiated and reconstituted mice that had recovered their T-cell function, as evidenced by rejection of allogeneic skin grafts. In both thymectomized and unthymectomized mice subjected to whole-body irradiation, the lung-colony-forming efficiency was high 1 day after irradiation, declined to a minimum at 7 days, and thereafter increased again, unless the animals were held in a pathogen-free environment. Reconstitution of T-cell-depleted mice with thymocytes and/or a thymic lobe graft tended to increase further, rather than reduce, lung-colony-forming efficiency. Induction of profound lymphopenia, by irradiation of the whole body except the thorax, did not significantly increase lung colony yields. These studies show that the lung colony assay is not a reliable method of assessing T-cell function in irradiated mice

Assessing Spectral Shortwave Cloud Observations at the Southern Great Plains Facility

The Atmospheric Radiation Measurement (ARM) program (now Atmospheric System Research) was established, in part, to improve radiation models so that they could be used reliably to compute radiation fluxes through the atmosphere, given knowledge of the surface albedo, atmospheric gases, and the aerosol and cloud properties. Despite years of observations, discrepancies still exist between radiative transfer models and observations, particularly in the presence of clouds. Progress has been made at closing discrepancies in the spectral region beyond 3 micron, but the progress lags at shorter wavelengths. Ratios of observed visible and near infrared cloud albedo from aircraft and satellite have shown both localized and global discrepancies between model and observations that are, thus far, unexplained. The capabilities of shortwave surface spectrometry have been improved in recent years at the Southern Great Plains facility (SGP) of the ARM Climate Research Facility through the addition of new instrumentation, the Shortwave Array Spectroradiometer, and upgrades to existing instrumentation, the Shortwave Spectroradiometer and the Rotating Shadowband Spectroradiometer. An airborne-based instrument, the HydroRad Spectroradiometer, was also deployed at the ARM site during the Routine ARM Aerial Facility Clouds with Low Optical Water Depths (CLOWD) Optical Radiative Observations (RACORO) field campaign. Using the new and upgraded spectral observations along with radiative transfer models, cloud scenes at the SGP are presented with the goal of characterizing the instrumentation and the cloud fields themselves

Molecular adaptation of ruminal epithelia to highly fermentable diets

Feeding highly fermentable diets to ruminants is one strategy to increase energy intake. The increase in short-chain fatty acid (SCFA) production and reduced ruminal pH associated with highly fermentable diets imposes a challenge to the metabolism and the regulation of intracellular pH homeostasis of ruminal epithelia. The ruminal epithelia respond to these challenges in a coordinated manner. Whereas the enlargement of absorptive surface area is well documented, emerging evidence at the mRNA and transporter and enzyme activity levels indicate that changes in epithelial cell function may be the initial response. It is not surprising that gene expression analysis has identified pathways involved in fatty acid metabolism, ion transport, and intracellular homeostasis to be the pathways dominantly affected during adaptation and after adaptation to a highly fermentable diet. These findings are important because the intraepithelial metabolism of SCFA, particularly butyrate, helps to maintain the concentration gradient between the cytosol and lumen, thereby facilitating absorption. Butyrate metabolism also controls the intracellular availability of butyrate, which is widely regarded as a signaling molecule. Current data indicate that for butyrate metabolism, 3-hydroxy-3 -methylglutaryl-CoA synthase and acetyl-CoA acetyltransferase are potential regulatory points with transient up- and downregulation during diet adaptation. In addition to nutrient transport and utilization, genes involved in the maintenance of cellular tight junction integrity and induction of inflammation have been identified as differentially expressed genes during adaptation to highly fermentable diets. This may have important implications on ruminal epithelial barrier function and the inflammatory response often associated with subacute ruminal acidosis. The objective of this review is to summarize ruminal epithelial adaptation to highly fermentable diets focusing on the changes at the enzyme and transporter activity levels, as well as the underlying molecular changes at the mRNA and protein expression levels

Differential expression of microRNA-206 and its target genes in pre-eclampsia

Objectives: Pre-eclampsia is a multi-system disease that significantly contributes to maternal and fetal morbidity and mortality. In this study, we used a non-biased microarray approach to identify novel circulating miRNAs in maternal plasma that may be associated with pre-eclampsia. Methods: Plasma samples were obtained at 16 and 28 weeks of gestation from 18 women who later developed pre-eclampsia (cases) and 18 matched women with normotensive pregnancies (controls). We studied miRNA expression profiles in plasma and subsequently confirmed miRNA and target gene expression in placenta samples. Placental samples were obtained from an independent cohort of 19 women with pre-eclampsia matched with 19 women with normotensive pregnancies. Results: From the microarray, we identified 1 miRNA that was significantly differentially expressed between cases and controls at 16 weeks of gestation and 6 miRNAs that were significantly differentially expressed at 28 weeks. Following qPCR validation only one, miR-206, was found to be significantly increased in 28 week samples in women who later developed pre-eclampsia (1.4 fold change ± 0.2). The trend for increase in miR-206 expression was mirrored within placental tissue from women with pre-eclampsia. In parallel, IGF-1, a target gene of miR-206, was also found to be down-regulated (0.41 ± 0.04) in placental tissue from women with pre-eclampsia. miR-206 expression was also detectable in myometrium tissue and trophoblast cell lines. Conclusions: Our pilot study has identified miRNA-206 as a novel factor up-regulated in pre-eclampsia within the maternal circulation and in placental tissue