Use of ordination and classification procedures to evaluate phytoplankton communities during Superflux II

Cluster analysis and an ordination procedure were performed on two data matrices to investigate real and environmental spatial relationships. Multiple regression analysis was used to relate the measured environmental variables to the phytoplankton community changes. Qualitative type phytoplankton data proved to be less structured in both of these spaces, relative to the biomass data. The salinity gradients of the northern transects covaried significantly with the phytoplankton association changes. In the southern transects the light variable was most important in explaining the variance in the ordination axes. These data suggest the close relationships between phytoplankton community changes and the physical hydrology of the area

A systems biology analysis of brain microvascular endothelial cell lipotoxicity.

BackgroundNeurovascular inflammation is associated with a number of neurological diseases including vascular dementia and Alzheimer's disease, which are increasingly important causes of morbidity and mortality around the world. Lipotoxicity is a metabolic disorder that results from accumulation of lipids, particularly fatty acids, in non-adipose tissue leading to cellular dysfunction, lipid droplet formation, and cell death.ResultsOur studies indicate for the first time that the neurovascular circulation also can manifest lipotoxicity, which could have major effects on cognitive function. The penetration of integrative systems biology approaches is limited in this area of research, which reduces our capacity to gain an objective insight into the signal transduction and regulation dynamics at a systems level. To address this question, we treated human microvascular endothelial cells with triglyceride-rich lipoprotein (TGRL) lipolysis products and then we used genome-wide transcriptional profiling to obtain transcript abundances over four conditions. We then identified regulatory genes and their targets that have been differentially expressed through analysis of the datasets with various statistical methods. We created a functional gene network by exploiting co-expression observations through a guilt-by-association assumption. Concomitantly, we used various network inference algorithms to identify putative regulatory interactions and we integrated all predictions to construct a consensus gene regulatory network that is TGRL lipolysis product specific.ConclusionSystem biology analysis has led to the validation of putative lipid-related targets and the discovery of several genes that may be implicated in lipotoxic-related brain microvascular endothelial cell responses. Here, we report that activating transcription factors 3 (ATF3) is a principal regulator of TGRL lipolysis products-induced gene expression in human brain microvascular endothelial cell

Disposal of Household Wastewater in Soils of High Stone Content (1981-1983)

Four experimental filter fields were constructed with built-in monitoring equipment in Nixa soils. These soils contain many chert fragments and a fragipan about 60 cm below the soil surface. The fragipan restricts downward movement of water and is the designlimitingfeature. The four filter fields were: 1. A standard filter field, 76 cm deep. The bottom of the trench was in the fragipan. 2. A modified standard filter field, 30 cm deep. The bottom of the trench was above the fragipan. 3. A modified pressure filter field, 40 cm deep. The bottom of the trench was above the fragipan. In addition, a pressure-distribution system was used to insure uniform distribution of effluent in the trench. Inadvertently, this field was installed in a different soil, and the results cannot be compared directly with the other three. 4. Another modified pressure filter field with the bottom of the trench only 6 cm below the soil surface. Observation of these systems confirms that placing filter fields higher in the soil above the hydraulically limiting horizon results in improved hydraulic performance. The presence of the fragipan amplified the adverse effects attributable to climatic stress. The seepage beds which are higher in the soil profile are able to handle the effluent load and climate load with less danger of surfacing

Effect of tethering chemistry of cationic surfactants on clay exfoliation, electrospinning and diameter of PMMA/clay nanocomposite fibers

We examine the influence of tethering chemistry of cationic surfactants on exfoliation of montmorillonite (MMT) clay dispersed in methyl methacrylate (MMA) followed by in-situ polymerization to form poly(methyl methacrylate) (PMMA) nanocomposites, the effect of exfoliation and clay loading on the rheology of polymer/clay dispersions in dimethyl formamide, and the diameters of nanocomposite fibers formed from these dispersions by electrospinning. Incorporation of an additional reactive tethering group of methacryl functionality significantly improves the intercalation and exfoliation of clays in both in-situ polymerized PMMA nanocomposites and the corresponding electrospun fibers. The proper surfactant chemistry also increases the dispersion stability, extensional viscosity, extent of strain hardening and thus the electrospinnablity of the nanocomposite dispersions, especially at low nanocomposite concentrations. The degree of the enhancement in electrospinnability by clays with proper tethering chemistry is at least the same as or greater than that obtained with three times higher loading level of clay particles without proper tethering chemistry in the nanocomposites. These results suggest a new strategy to produce smaller diameter fibers from very dilute polymer solutions, which are otherwise not electrospinnable, by incorporating a small amount of well-exfoliated clays.Massachusetts Institute of Technology. Institute for Soldier Nanotechnologies (Contract DAAD-19-02-D0002

Molecular Simulation of Flow-Enhanced Nucleation in n-Eicosane Melts Under Steady Shear and Uniaxial Extension

Non-equilibrium molecular dynamics is used to study crystal nucleation of n-eicosane under planar shear and, for the first time, uniaxial extension. A method of analysis based on the mean first-passage time is applied to the simulation results in order to determine the effect of the applied flow field type and strain rate on the steady-state nucleation rate and a characteristic growth rate, as well as the effects on kinetic parameters associated with nucleation: the free energy barrier, critical nucleus size, and monomer attachment pre-factor. The onset of flow-enhanced nucleation (FEN) occurs at a smaller critical strain rate in extension as compared to shear. For strain rates larger than the critical rate, a rapid increase in the nucleation rate is accompanied by decreases in the free energy barrier and critical nucleus size, as well as an increase in chain extension. These observations accord with a mechanism in which FEN is caused by an increase in the driving force for crystallization due to flow-induced entropy reduction. At high applied strain rates, the free energy barrier, critical nucleus size, and degree of stretching saturate, while the monomer attachment pre-factor and degree of orientational order increase steadily. This trend is indicative of a significant diffusive contribution to the nucleation rate under intense flows that is correlated with the degree of global orientational order in a nucleating system. Both flow fields give similar results for all kinetic quantities with respect to the reduced strain rate, which we define as the ratio of the applied strain rate to the critical rate. The characteristic growth rate increases with increasing strain rate, and shows a correspondence with the nucleation rate that does not depend on the type of flow field applied. Additionally, a structural analysis of the crystalline clusters indicates that the flow field suppresses the compaction and crystalline ordering of clusters, leading to the formation of large articulated clusters under strong flow fields, and compact well-ordered clusters under weak flow fields

A 23 GHz Survey of GRB Error Boxes

The Haystack 37-meter telescope was used in a pilot project in May 1995 to observe GRB error boxes at 23~GHz. Seven BATSE error boxes and two IPN arcs were scanned by driving the beam of the telescope rapidly across their area. For the BATSE error boxes, the radio observations took place two to eighteen days after the BATSE detection, and several boxes were observed more than once. Total power data were recorded continuously as the telescope was driven at a rate of 0.2~degrees/second, yielding Nyquist sampling of the beam with an integration time of 50~milliseconds, corresponding to a theoretical rms sensitivity of 0.5~Jy. Under conditions of good weather, this sensitivity was achieved. In a preliminary analysis of the data we detect only two sources, 3C273 and 0552+398, both catalogued sources that are known to be variable at 23~GHz. Neither had a flux density that was unusally high or low at the time of our observations.Comment: 5 pages, 1 postscript figure. To appear in Proceedings of the Third Huntsville Symposium on Gamma-Ray Bursts (eds. C. Kouveliotou, M. S. Briggs, and G. J. Fishman

The Host Galaxy and Central Engine of the Dwarf AGN POX 52

We present new multi-wavelength observations of the dwarf Seyfert 1 galaxy POX 52 in order to investigate the properties of the host galaxy and the active nucleus, and to examine the mass of its black hole, previously estimated to be ~ 10^5 M_sun. Hubble Space Telescope ACS/HRC images show that the host galaxy has a dwarf elliptical morphology (M_I = -18.4 mag, Sersic index n = 4.3) with no detected disk component or spiral structure, confirming previous results from ground-based imaging. X-ray observations from both Chandra and XMM show strong (factor of 2) variability over timescales as short as 500 s, as well as a dramatic decrease in the absorbing column density over a 9 month period. We attribute this change to a partial covering absorber, with a 94% covering fraction and N_H = 58^{+8.4}_{-9.2} * 10^21 cm^-2, that moved out of the line of sight in between the XMM and Chandra observations. Combining these data with observations from the VLA, Spitzer, and archival data from 2MASS and GALEX, we examine the spectral energy distribution (SED) of the active nucleus. Its shape is broadly similar to typical radio-quiet quasar SEDs, despite the very low bolometric luminosity of L_bol = 1.3 * 10^43 ergs/s. Finally, we compare black hole mass estimators including methods based on X-ray variability, and optical scaling relations using the broad H-beta line width and AGN continuum luminosity, finding a range of black hole mass from all methods to be M_bh = (2.2-4.2) * 10^5 M_sun, with an Eddington ratio of L_bol/L_edd = 0.2-0.5.Comment: 19 pages, 16 figures, accepted for publication in Ap

Clergy work-related satisfactions in parochial ministry: the influence of personality and churchmanship

The aim of this study was to test several hypotheses that clergy work-related satisfaction could be better explained by a multidimensional rather than a unidimensional model. A sample of 1071 male stipendiary parochial clergy in the Church of England completed the Clergy Role Inventory, together with the short-form Revised Eysenck Personality Questionnaire. Factor analysis of the Clergy Role Inventory identified five separate clergy roles: Religious Instruction, Administration, Statutory Duties (conducting marriages and funerals), Pastoral Care, and Role Extension (including extra-parochial activities). Respondents also provided an indication of their predispositions on the catholic-evangelical and liberal-conservative dimensions. The significant associations of the satisfactions derived from each of the roles with the demographic, personality, and churchmanship variables were numerous, varied, and, with few exceptions, small in magnitude. Separate hierarchical regressions for each of the five roles indicated that the proportion of total variance explained by churchmanship was, in general, at least as great as that explained by personality, and was greater for three roles: Religious Instruction, Statutory Duties, and Role Extension. It was concluded that clergy satisfactions derived from different roles are not uniform and that churchmanship is at least as important as personality in accounting for clergy work satisfaction

Disposal of Household Wastewater in Soils of High Stone Content (1977-1980)

Two experimental septic tank filter fields were constructed with built-in monitoring equipment in Nixa soils. These soils contain many chert fragments and a fragipan about 60 cm deep which restricts downward water movement and is the design-limiting feature. The standard filter field (76 cm deep) was built into the fragipan and the modified standard filter field (30 cm deep) was placed above it. During 30 months\u27 observation, the modified standard performed better than the standard filter field. Maximum rise of effluent in the standard and modified standard came within 11 and 19 cm of the soil surface, respectively. Performance of these systems indicates filter fields should be designed to function during climatic stresses, i.e. when the soil has a maximum hydraulic load and surfacing may occur. Filter fields should be designed to withstand a stress period of specified intensity. The filter fields in this study were observed under less than normal stress. Therefore, their long range performance is less clear. Our observations indicate that filter field performance is related more to rates of water movement than to stone content. Major influences on filter field performance are rates and directions of water movement, stress period intensity, designs, and construction techniques