A continuation of base-line studies for environmentally monitoring space transportation systems at John F. Kennedy Space Center. Executive summary

Studies conducted in and around John F. Kennedy Space Center, Merrit Island, Florida were designed to establish baseline conditions for various attributes of the biotic and abiotic environment. Features were described and quantitatively measured. Certain condition were found to be appropriate for the detection and assessment of possible environmental perturbations caused by future NASA activities. These include plant communities, mammal populations, rainfall chemistry, fish populations, and the status of rare and endangered species. On the basis of statistical analysis of quantitative data and logistic considerations, it was possible to refine the kinds and amounts of measurements needed to evaluate perturbations in selected environmental components

A Continuation of Base-Line Studies for Environmentally Monitoring Space Transportation System (STS) at John F. Kennedy Space Center

Vegetation and small mammal populations in or around the Merritt Island area were studied. Thirty sites were selected from plant communities which were relatively free of logging, grazing, and clearing operations. The vegetative analysis was designed to yield a quantitative description and ecological explanation of the major types of upland vegetation in order to determine the possible future effects of NASA space activities on them. Changes in the relative abundance of small mammal populations, species diversity, standing crop biomass, reproductive activity, and other demographic features were documented in order to gather sufficient information on these populations so that it would be possible to detect even the smaller nonnatural behavior changes in the mammals which might be attributable to NASA space activities

Ecological effects and environmental fate of solid rocket exhaust

Specific target processes were classified as to the chemical, chemical-physical, and biological reactions and toxic effects of solid rocket emissions within selected ecosystems at Kennedy Space Center. Exposure of Citris seedlings, English peas, and bush beans to SRM exhaust under laboratory conditions demonstrated reduced growth rates, but at very high concentrations. Field studies of natural plant populations in three diverse ecosystems failed to reveal any structural damage at the concentration levels tested. Background information on elemental composition of selected woody plants from two terrestrial ecosystems is reported. LD sub 50 for a native mouse (peromysous gossypinus) exposed to SRM exhaust was determined to be 50 ppm/g body weight. Results strongly indicate that other components of the SRM exhaust act synergically to enhance the toxic effects of HCl gas when inhaled. A brief summary is given regarding the work on SRM exhaust and its possible impact on hatchability of incubating bird eggs

Life History And Productivity Of Hexagenia Limbata (Ephemeroptera: Ephemeridae) And Selected Physico-Chemical Parameters In Two Tributaries Of The Wekiva River, Central Florida

Nymphal densities and size frequency distribution of Hexagenia limbata (Serville), a burrowing mayfly, were determined monthly for two years in two tributaries of the Wekiva River, central Florida, along with selected physico-chemical water parameters. Blackwater Creek supported a mean number of 112 (range 0-434) and Rock Springs Run 89 nymphs per m(2) (range 11-258). The mayfly species displayed a univoltine life history with adult emergence peaking in August. Productivity in Blackwater Creek was estimated at 4.688 g per m(2) and in Rock Springs Run at 3.123 g per m(2). Productivity/biomass ratios were estimated at 4.09 and 4.59 in Blackwater Creek and Rock Springs Run, respectively. The nymphal densities in both streams were positively correlated with water pH and negatively correlated with water volume. Apparently, water volume was the overriding abiotic factor in both streams, influencing several measured water parameters and as well as nymphal populations during the study period

Qualitative And Quantitative Studies On Chironomidae (Diptera) And Selected Physico-Chemical Parameters In Two Tributaries Of The Wekiva River, Central Florida

Aquatic midge (Chironomidae: Diptera) larval densities, 24-h adult emergence, and larval and adult dry biomass were estimated monthly for two years in two tributaries of the Wekiva River, central Florida, along with selected physico-chemical water parameters. Twenty-four genera of midges were identified in Blackwater Creek and 26 in Rock Springs Run, with subfamily Chironominae dominating the midge fauna. Larval densities in the former stream ranged from 56 to 757 per m(2), with 24-h periods adult emergence ranging from 0 to 95 per m(2). The latter stream supported 138 to 1277 larvae per m(2) with 0 to 68 emergent adults per m(2) taken during 24-h periods. Mean larval biomass in Rock Springs Run (42 mg per m(2)) was significantly (P \u3c 0.05) higher than in Blackwater Creek (27 mg per m(2)), while mean adult biomass in both habitats was essentially identical (1.1 mg per m(2)). Annual midge productivity estimates (1.12 g dry wt per m(2)) in each stream indicated that both were oligotrophic. Water volume was the overriding abiotic factor noted in both habitats, influencing many of the observed water parameters and altering the midge generic composition, especially in Blackwater Creek

Clinical Diagnosis of Placenta Accreta and Clinicopathological Outcomes

Objective To investigate the association between the intraoperative diagnosis of placenta accreta at the time of cesarean hysterectomy and pathological diagnosis. Study Design This is a retrospective cohort study of all patients undergoing cesarean hysterectomy for suspected placenta accreta from 2000 to 2016 at Barnes-Jewish Hospital. The primary outcome was the presence of invasive placentation on the pathology report. We estimated predictive characteristics of clinical diagnosis of placenta accreta using pathological diagnosis as the correct diagnosis. Results There were 50 cesarean hysterectomies performed for suspected abnormal placentation from 2000 to 2016. Of these, 34 (68%) had a diagnosis of accreta preoperatively and 16 (32%) were diagnosed intraoperatively at the time of cesarean delivery. Two patients had no pathological evidence of invasion, corresponding to a false-positive rate of 4% (95% confidence interval [CI]: 0.5%, 13.8%) and a positive predictive value of 96% (95% CI: 86.3%, 99.5%). There were no differences in complications among patients diagnosed intraoperatively compared with those diagnosed preoperatively. Conclusion Most patients undergoing cesarean hysterectomy for placenta accreta do have this diagnosis confirmed on pathology. However, since the diagnosis of placenta accreta was made intraoperatively in nearly a third of cesarean hysterectomies, intraoperative vigilance is required as the need for cesarean hysterectomy may not be anticipated preoperatively

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Critical temperature of a fully anisotropic three-dimensional Ising model

The critical temperature of a three-dimensional Ising model on a simple cubic lattice with different coupling strengths along all three spatial directions is calculated via the transfer matrix method and a finite size scaling for L x L oo clusters (L=2 and 3). The results obtained are compared with available calculations. An exact analytical solution is found for the 2 x 2 oo Ising chain with fully anisotropic interactions (arbitrary J_x, J_y and J_z).Comment: 17 pages in tex using preprint.sty for IOP journals, no figure

Parallel, Adaptive‐Mesh‐Refinement MHD for Global Space‐Weather Simulations

The first part of this paper reviews some issues representing major computational challenges for global MHD models of the space environment. These issues include mathematical formulation and discretization of the governing equations that ensure the proper jump conditions and propagation speeds, regions of relativistic Alfvén speed, and controlling the divergence of the magnetic field. The second part of the paper concentrates on modern solution methods that have been developed by the aerodynamics, applied mathematics and DoE communities. Such methods have recently begun to be implemented in space‐physics codes, which solve the governing equations for a compressible magnetized plasma. These techniques include high‐resolution upwind schemes, block‐based solution‐adaptive grids and domain decomposition for parallelization. We describe the space physics MHD code developed at the University of Michigan, based on the developments listed above. © 2003 American Institute of PhysicsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87656/2/807_1.pd

Predictive value of midtrimester universal cervical length screening based on parity

OBJECTIVES: To evaluate the effect of parity on performance characteristics of midtrimester cervical length (CL) in predicting spontaneous preterm birth (sPTB) before 37 weeks. METHODS: This was a retrospective cohort study of 13,508 women with no history of sPTB undergoing universal transvaginal CL screening at 17 to 23 weeks\u27 gestation from 2011 to 2016. Patients who declined screening or with unknown delivery outcomes were excluded. Areas under the receiver operator characteristic curves were used to assess and compare the predictive ability of CL screening for sPTB. The sensitivity, specificity, and positive and negative predictive values were estimated for specific CL cutoffs for prediction of sPTB. RESULTS: There were 20,100 patients, of whom 2087 (10%) declined screening and 4505 (22%) did not meet inclusion criteria. Of the remaining 13,508 patients, 43% were nulliparous. The incidence rates of sPTB were 6.5% in nulliparas and 4.9% in multiparas (P \u3c .001). The mean CLs were 39.9 mm in nulliparas and 41.8 mm in multiparas (P \u3c .001), and those of the first percentiles were 19.0 mm in nulliparas and 24.0 mm in multiparas. Cervical length was significantly more predictive of sPTB in nulliparas (area under the curve, 0.67; 95% confidence interval, 0.63-0.70; versus 0.61, 95% confidence interval, 0.57-0.63; P = .008). At CL cutoffs of 10, 15, 20, and 25 mm or less, the sensitivity was lower in multiparas, and the specificity was comparable between the groups. CONCLUSIONS: Midtrimester CL is less predictive of sPTB in multiparas compared to nulliparas. The poor predictive ability, especially in multiparas, calls into question the value of universal CL screening in this population