182 research outputs found
An early Pennsylvanian Flora with \u3cem\u3eMegalopteris\u3c/em\u3e and Noeggerathiales from west-central Illinois
The Spencer Farm Flora is a compression-impression flora of early Pennsylvanian age (Namurian B, or possibly Namurian C) from Brown County, west-central Illinois. The plant fossils occur in argillaceous siltstones and sandstones of the Caseyville Formation that were deposited in a ravine eroded in Mississippian carbonate rocks. The plant-bearing beds are the oldest deposits of Pennsylvanian age yet discovered in Illinois. They were formed before extensive Pennsylvanian coal swamps developed.
The flora consist of 29 species and a few problematical forms. It represents an unusual biofacies, in which the generally rare genera Megalopteris, Lesleya, Palaeopteridium, and Lacoea are quite common. Noeggerathiales, which are seldom present in roof-shale floras, make up 20% of the specimens. The Spencer Farm Flora is and extrabasinal (= upland ) flora that was growing on the calcareous soils in the vicinity of the ravine in which they were deposited.
It is suggested here that Noeggerathiales may belong to the Progymnosperms and that Noeggerathialian cones might be derived from Archaeopteris-like fruitifications. The cone genus Lacoea is intermediate between Noeggerathiostrobus and Discinites in its morphology. Two new species, Lesleya cheimarosa and Rhodeopteridium phillipsii, are described, and Gulpenia limburgensis is reported from North America for the first time
Innovative interstellar explorer
An interstellar "precursor" mission has been under discussion in the scientific community for at least 30 years. Fundamental scientific questions about the interaction of the Sun with the interstellar medium can only be answered with in situ measurements that such a mission can provide. The Innovative Interstellar Explorer (IIE) and its use of Radioisotope Electric Propulsion (REP) is being studied under a NASA "Vision Mission" grant. Speed is provided by a combination of a high-energy launch, using current launch vehicle technology, a Jupiter gravity assist, and long-term, low-thrust, continuous acceleration provided by an ion thruster running off electricity provided by advanced radioisotope electric generators. A payload of ten instruments with an aggregate mass of ~35 kg and requiring ~30 W has been carefully chosen to address the compelling science questions. The nominal 20-day launch window opens on 22 October 2014 followed by a Jupiter gravity assist on 5 February 2016. The REP system accelerates the spacecraft to a "burnout" speed of 7.8 AU per year at 104 AU on 13 October 2032 (Voyager 1's current speed is ~3.6 AU/yr). The spacecraft will return at least 500 bits per second from at least 200 AU ~30 years after launch. Additional (backup) launch opportunities occur every 13 months to early 2018. In addition to addressing basic heliospheric science, the mission will ensure continued information on the far-heliospheric galactic cosmic ray population after the Voyagers have fallen silent and as the era of human Mars exploration begins
Seismic imaging in Long Valley, California, by surface and borehole techniques: An investigation of active tectonics
The search for silicic magma in the upper crust is converging on the Long Valley Caldera of eastern California, where several lines of geophysical evidence show that an active magma chamber exists at mid‐to lower‐crustal depths. There are also other strong indications that magma may be present at depths no greater than about 5 km below the surface. In this paper, we review the history of the search for magma at Long Valley. We also present the preliminary results from a coordinated suite of seismic experiments, conducted by a consortium of institutions in the summer and fall of 1984, that were designed to refine our knowledge of the upper extent of the magma chamber. Major funding for the experiments was provided by the Geothermal Research Program of the U.S. Geological Survey (USGS) and by the Magma Energy Technology Program of the U.S. Department of Energy (DOE), a program to develop the technology necessary to extract energy directly from crustal magma. Additional funding came from DOE's Office of Basic Energy Sciences and the National Science Foundation (NSF). Also, because extensive use was made of a 0.9‐km‐deep well lent to us by Santa Fe Geothermal, Inc., the project was conducted partly under the auspices of the Continental Scientific Drilling Program (CSDP). As an integrated seismic study of the crust within the caldera that involved the close cooperation of a large number of institutions, the project was moreover viewed as a prototype for future scientific experiments to be conducted under the Program for Array Seismic Studies of the Continental Lithosphere (PASSCAL). The experiment thus represented a unique blend of CSDP and PASSCAL methods, and achieved goals consistent with both programs
Structural outcomes in the Cleft Care UK study. Part 2:Dento-facial outcomes
OBJECTIVES: To compare facial appearance and dento-alveolar relationship outcomes from the CSAG (1998) and CCUK (2013) studies. SETTING AND SAMPLE POPULATION: Five-year-olds born with non-syndromic unilateral cleft lip and palate. Those in the original CSAG were treated in a dispersed model of care with low-volume operators. Those in CCUK were treated in a more centralized, high-volume operator model. MATERIALS AND METHODS: We compared facial appearance using frontal view photographs (252 CCUK, 239 CSAG) and dental relationships using study models (198 CCUK, 223 CSAG). Facial appearance was scored by a panel of six assessors using a standardized and validated outcome tool. Dento-alveolar relationships were scored by two assessors using the 5-Year-Olds’ Index. Ordinal regression was used to compare results between surveys. RESULTS: Excellent or good facial appearance was seen in 36.2% of CCUK compared with 31.9% in CSAG. In CCUK, 21.6% were rated as having poor or very poor facial appearance compared with 27.6% in CSAG. The percentage rated as having excellent or good dento-alveolar relationships was 53.0% in CCUK compared with 29.6% in CSAG. In CCUK, 19.2% were rated as having poor or very poor dento-alveolar relationships compared to 36.3% in CSAG. The odds ratios for improved outcome in CCUK compared to CSAG were 1.43 (95% CI 1.03, 1.97) for facial appearance and 2.29 (95% CI 1.47, 3.55) for dento-alveolar relationships. CONCLUSIONS: Facial and dento-alveolar outcomes were better in CCUK children compared to those in CSAG
Molecular Classification of the PORTEC-3 Trial for High-Risk Endometrial Cancer:Impact on Prognosis and Benefit From Adjuvant Therapy
PURPOSE The randomized Adjuvant Chemoradiotherapy Versus Radiotherapy Alone in Women With High-Risk Endometrial Cancer (PORTEC-3) trial investigated the benefit of combined adjuvant chemotherapy and radiotherapy (CTRT) versus radiotherapy alone (RT) for women with high-risk endometrial cancer (EC). Because The Cancer Genome Atlas defined an EC molecular classification with strong prognostic value, we investigated prognosis and impact of chemotherapy for each molecular subgroup using tissue samples from PORTEC-3 trial participants. METHODS Paraffin-embedded tissues of 423 consenting patients were collected. Immunohistochemistry for p53 and mismatch repair (MMR) proteins, and DNA sequencing for POLE exonuclease domain were done to classify tumors as p53 abnormal (p53abn), POLE-ultramutated (POLEmut), MMR-deficient (MMRd), or no specific molecular profile (NSMP). The primary end point was recurrence-free survival (RFS). Kaplan-Meier method, log-rank test, and Cox model were used for analysis. RESULTS Molecular analysis was successful in 410 high-risk EC (97%), identifying the 4 subgroups: P53abn EC (n = 93; 23%), POLEmut (n = 51; 12%), MMRd (n = 137; 33%), and NSMP (n = 129; 32%). Five-year RFS was 48% for patients with p53abn EC, 98% for POLEmut EC, 72% for MMRd EC, and 74% for NSMP EC (P <001). The 5-year RFS with CTRT versus RT for p53abn EC was 59% versus 36% (P =019); 100% versus 97% for patients with POLEmut EC (P =637); 68% versus 76% (P =428) for MMRd EC; and 80% versus 68% (P =243) for NSMP EC. CONCLUSION Molecular classification has strong prognostic value in high-risk EC, with significantly improved RFS with adjuvant CTRT for p53abn tumors, regardless of histologic type. Patients with POLEmut EC had an excellent RFS in both trial arms. EC molecular classification should be incorporated in the risk stratification of these patients as well as in future trials to target specific subgroups of patients
Long-lived charged states of single porphyrin-tape junctions under ambient conditions
The ability to control the charge state of individual molecules wired in two-terminal single-molecule junctions is a key challenge in molecular electronics, particularly in relation to the development of molecular memory and other computational componentry. Here we demonstrate that single porphyrin molecular junctions can be reversibly charged and discharged at elevated biases under ambient conditions due to the presence of a localised molecular eigenstate close to the Fermi edge of the electrodes. In particular, we can observe long-lived charge-states with lifetimes upwards of 1–10 seconds after returning to low bias and large changes in conductance, in excess of 100-fold at low bias. Our theoretical analysis finds charge-state lifetimes within the same time range as the experiments. The ambient operation demonstrates that special conditions such as low temperatures or ultra-high vacuum are not essential to observe hysteresis and stable charged molecular junctions
Why organizational and community diversity matter:Representativeness and the Emergence of Incivility and Organizational Performance
Integrating sociological and psychological perspectives, this research considers the value of organizational ethnic diversity as a function of community diversity. Employee and patient surveys, census data, and performance indexes relevant to 142 hospitals in the United Kingdom suggest that intraorganizational ethnic diversity is associated with reduced civility toward patients. However, the degree to which organizational demography was representative of community demography was positively related to civility experienced by patients and ultimately enhanced organizational performance. These findings underscore the understudied effects of community context and imply that intergroup biases manifested in incivility toward out-group members hinder organizational performance
Bias-driven conductance increase with length in porphyrin tapes
A key goal in molecular electronics has been to find molecules that facilitate efficient charge transport over long distances. Normally molecular wires become less conductive with increasing length. Here we report a series of fused porphyrin oligomers for which the conductance increases substantially with length by > 10-fold at a bias of 0.7 V. This exceptional behavior can be attributed to the rapid decrease of the HOMO-LUMO gap with the length of fused porphyrins. In contrast, for butadiyne-linked porphyrin oligomers with moderate inter-ring coupling, a normal conductance decrease with length is found for all bias voltages explored (± 1 V), although the attenuation factor (β) decreases from ca. 2 nm-1 at low bias to < 1 nm-1 at 0.9 V, highlighting that β is not an intrinsic molecular property. Further theoretical analysis using density functional theory underlines the role of inter-site coupling and indicates that this large increase in conductance with length at increasing voltages can be generalized to other molecular oligomers
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