Electronics systems test laboratory testing of shuttle communications systems

Shuttle communications and tracking systems space to space and space to ground compatibility and performance evaluations are conducted in the NASA Johnson Space Center Electronics Systems Test Laboratory (ESTL). This evaluation is accomplished through systems verification/certification tests using orbiter communications hardware in conjunction with other shuttle communications and tracking external elements to evaluate end to end system compatibility and to verify/certify that overall system performance meets program requirements before manned flight usage. In this role, the ESTL serves as a multielement major ground test facility. The ESTL capability and program concept are discussed. The system test philosophy for the complex communications channels is described in terms of the major phases. Results of space to space and space to ground systems tests are presented. Several examples of the ESTL's unique capabilities to locate and help resolve potential problems are discussed in detail

Rigid ball-polyhedra in Euclidean 3-space

A ball-polyhedron is the intersection with non-empty interior of finitely many (closed) unit balls in Euclidean 3-space. One can represent the boundary of a ball-polyhedron as the union of vertices, edges, and faces defined in a rather natural way. A ball-polyhedron is called a simple ball-polyhedron if at every vertex exactly three edges meet. Moreover, a ball-polyhedron is called a standard ball-polyhedron if its vertex-edge-face structure is a lattice (with respect to containment). To each edge of a ball-polyhedron one can assign an inner dihedral angle and say that the given ball-polyhedron is locally rigid with respect to its inner dihedral angles if the vertex-edge-face structure of the ball-polyhedron and its inner dihedral angles determine the ball-polyhedron up to congruence locally. The main result of this paper is a Cauchy-type rigidity theorem for ball-polyhedra stating that any simple and standard ball-polyhedron is locally rigid with respect to its inner dihedral angles.Comment: 11 pages, 2 figure

Differentiating c8-t1 radiculopathy from ulnar neuropathy: A survey of 24 spine surgeons

Study Design Questionnaire. Objective To evaluate the ability of spine surgeons to distinguish C8–T1 radiculopathies from ulnar neuropathy. Methods Twenty-four self-rated “experienced” cervical spine surgeons completed a questionnaire with the following items. (1) If the ulnar nerve is cut at the elbow, which of the following would be numb: ulnar forearm, small and ring fingers; only the ulnar forearm; only the small and ring fingers; or none of the above? (2) Which of the following muscles are weak with C8–T1 radiculopathies but intact with ulnar neuropathy at the elbow: flexor digiti minimi brevis, flexor pollicis brevis, abductor digiti minimi, abductor pollicis brevis, adductor pollicis, opponens digiti minimi, opponens pollicis, medial lumbricals, lateral lumbricals, dorsal interossei, palmar interossei? Results Fifteen of 24 surgeons (63%) correctly answered the first question—that severing the ulnar nerve results in numbness of the fifth and fourth fingers. None correctly identified all four nonulnar, C8–T1-innervated options in the second question without naming additional muscles. Conclusion The ulnar nerve provides sensation to the fourth and fifth fingers and medial border of the hand. The medial antebrachial cutaneous nerve provides sensation to the medial forearm. The ulnar nerve innervates all intrinsic hand muscles, except the abductor and flexor pollicis brevis, opponens pollicis, and lateral two lumbricals, which are innervated by C8 and T1 via the median nerve. By examining these five muscles, one can clinically differentiate cubital tunnel syndrome from C8–T1 radiculopathies. Although all participants considered themselves to be experienced cervical spine surgeons, this study reveals inadequate knowledge regarding the clinical manifestations of C8–T1 radiculopathies and cubital tunnel syndrome

The effect of manipulating training demands and consequences on experiences of pressure in elite netball

Testing the efficacy of a pressure training framework (Stoker, Lindsay, Butt, Bawden, & Maynard, 2016), the present study investigated whether manipulating training demands and consequences altered experiences of pressure. Elite Netballers (Mage = 26.14 years) performed a Netball exercise in a randomized, within subject design with four conditions: a control, consequences, demands, and demands plus consequences condition. Compared with the control, self-reported pressure was significantly higher in the consequences and demands plus consequences condition, but not in the demands condition. The findings provide mixed support for manipulating demands and strong support for manipulating consequences as a means for producing pressure. Key words: pressure training, stress, anxiety, stressor, coping, choking, demands, consequence, forfeit, reward, judgmen

Metabolic responses of osteochondral allografts to re-warming after MOPS(TM) preservation versus standard of care storage

Osteoarthritis (OA) affects ~90% of people older than 65, and associated costs top $100 billion annually in the U.S. One treatment available for large cartilage defects seen in osteoarthritis is osteochondral allograft (OCA) transplantation. Currently, tissue banks store OCAs at 4 degree C and implantation is recommended within 28 days after procurement due to significant loss in chondrocyte viability after this time. Because mandatory disease screening protocols typically take 14 days to complete, the window for surgical implantation is narrow, which severely limits clinical use. The MOPS(TM) protocol can maintain OCAs for 56 days. In this study, OCAs stored using MOPS(TM) and SOC protocol were assessed for cell viability and metabolic biomarker production

Rockall Continental Margin Report. Final geological report (5 volumes)

The Rockall Continental Margin Project was a 3-year research programme, undertaken between April 1992 and March 1995, designed to investigate the geology and resource potential of part of the frontier area west of Scotland. The programme was funded by a consortium comprising the British Geological Survey (BGS) and 8 exploration companies - BP, British Gas, Conoco, EE Caledonia, Elf, Enterprise, Esso and Mobil. The study has focused on the central and northern Rockall Trough, although several long transect lines were run across the Rockall Plateau and into the Iceland Basin to provide a margin-wide assessment of the geological framework. Over the duration of the project, multichannel seismic, gravity, magnetic and bathymetry data, together with boreholes and shallow-sample information were acquired by the consortium. These data form the basis of this 5-volume report. A descriptiono f the geology and prospectivityo f the surveyed area comprises volume 1, whilst the data on which the geological interpretation is based, including biostratigraphy, petrology and geochemistry of the boreholes and shallow samples, are presented in volumes 2 to 5. The widespread distribution of Upper Cretaceous to lower Palaeogene volcanic rocks continues to hinder our understandionfg t he geological frameworkof the Rockall Continental Margin. Whilst it has been proved that Lower Proterozoic gneisses form continental basement on Rockall Bank, and are therefore part of the Islay structural terrane, the pre-Cretaceous supracrustal infill of the Rockall Trough and Hatton-Rockall Basin remains conjectural. Reworked palynomorphs of Carboniferous, Jurassic and Early Cretaceous age have been identified in lower Palaeogene sediments recovered on the western margin of the Rockall Trough, but their provenance is uncertain. The present morphological expressiono f the Rockall Continental Margin largely reflects late Mesozoic-Cenozoic extensional tectonism associated with North Atlantic sea-floor spreading. In mid-Cretaceous time, the Rockall Trough was the focus of extreme crustal attenuation associated with abortive continental breakup along the axis of the basin. The growth of the axid Rosemary Bank and Anton D o h s eamounts may have been initiated duringth is phase of crustal thinning. When the axis of spreading shifted westwards, the margin was affected by extensive volcanism concomitant with the split between Rockall Plateau and Greenland, that formed the North-East Atlantic OceaInn. the study area, this volcanismis manifested by the areally extensive, Paleocene to lower Eocene lavas and sills. The continental margin subsequently underwent regional differential subsidence punctuated by intermittent tectonism. This is reflected in the post-volcanic, sedimentary succession for which, for the first time, a unified seismic stratigraphy linking the Rockall Trough and Hatton-Rockall Basin has been established. Three main post-volcanic seismic-stratigraphical sequences have been defined; upper Paleocene to lower upper Eocene, upper Eocene to middle Miocene, and middle Miocene to Holocene. Stratigraphical control and inter-basin correlation are based on a databaseo f BGS boreholes and shallow samples, DSDP boreholes and well 164/25-2 (courtesy of BP). Late Paleocene to early late Eocene sedimentation occurred amidst continuing tectonic instability across the margin. This has been well demonstrated on the edge of Rockall Bank where a prograding shelf-margin sequence penetratebdy borehole 94/3 preserves a record of fluctuating alluvial to shallow-marine sedimentation, interrupted by phases of uplift, erosion and sporadic volcanism. Late Eocene subsidence in the Rockall Trough and Hatton-Rockall Basin provided the downwarped, basin-margin unconformity onto which upper Eocene to middle Miocene sediments onlap. This is a major sequence boundary and essentially marks the onset of deep-water, current-controlled sedimentation in both basins. In the Rockall Trough, the main buildup of the Feni Ridge sediment drift occurred during this interval. A phase of mid-Miocene tectonism resulted in the initiationo f the Barra Fan, on the eastern margin of the Rockall Trough, and may also have instigated a change in regional palaeoceanography culminating in the developmenotf a widespread unconformity across the Rockall Trough and Hatton-Rockall Basin. On the Hebrides Slope, middle Miocene to Holocene sediments form a thick, prograding, clastic weAd gthei.n ner package of deep-water sediments is preserved in the Rockall Trough and, on the western margin of the trough, an erosional regime has prevailed throughout this interval. This has resulted in a marked asymmetry to the depositional sequence architecture across the Rockall Trough. The Hatton- Rockall Basin was similarly dominated by deep-water processes but, in contrast to the Rockall Trough, a much thicker sedimentary succession has accumulated in this basin. In terms of prospectivity, circumstantial evidence suggests that Carboniferous, Mesozoic or lower Tertiary source rocks may be present in the Rockall Trough, but no definite thermogenic source has been proved. Potential hydrocarbon indicators include gas blanking, fluid-migration structures and locally high methane concentrations in surface sediments. The identification of tilted fault blocks on the western margoifn the Rockall Trough, in bothU K and Irish waters, illustrates one possible hydrocarbon-trapping mechanism that may be applicable to this area. Other potential trapping styles include fault-scarp fans and lowstand slope-apron or basin-floor fans