Ambient Geochemical and Isotopic Variations in Groundwaters Across an Area of Accelerating Shale Gas Development

One of the main challenges associated with Marcellus Formation shale gas development is to ensure proper management and disposal of flowback water produced as a result of hydraulic fracturing of gas wells. The flowback water consists of a mixture of returned frac\u27ing fluids and highly saline formation brines. As a result, improper management or disposal of this flowback can potentially contaminate the fresh surface waters and groundwaters of the area. To better assess any detrimental effect on water quality, there is need to understand the natural geochemical variations prior to the rapid expansion of gas drilling in the area.;This study focuses on documenting the baseline geochemical characteristics of groundwaters in different formations lying stratigraphically above the Marcellus Formation. 41 groundwater well sites in north central West Virginia were sampled with the USGS Water Science Center of West Virginia. These private and public sampling locations were chosen from within the United States Geological Survey database and represent different formation aquifers with differing well depths. Geochemical data was obtained for major cations and anions, dissolved gas concentrations of methane, oxygen and hydrogen isotopic compositions of water (delta18OH2O and delta 2HH2O), carbon isotopic compositions of dissolved inorganic carbon (delta13CDIC), sulfur and oxygen isotope compositions of dissolved sulfate (delta34SSO4 and delta18OSO4) and carbon and hydrogen isotope compositions of dissolved methane (delta13CCH4 and delta2HCH4). Field parameters of temperature, conductivity, pH, dissolved oxygen, turbidity, and oxidation reduction potential were also collected. I hypothesize that the baseline variations of stable isotopes can be used in conjunction with other geochemical parameters to identify groundwater aquifers that have received significant contribution from frac flowback waters

Low prevalence of an acute phase response in asymptomatic children from a malaria-endemic area of Papua New Guinea

Levels of C-reactive protein (CRP), a classic marker for the acute phase response (APR), were measured in children with asymptomatic malaria infection in the Amele region of Papua New Guinea (PNG). Despite the presence of parasitemia, the prevalence of CRP levels consistent with an APR (CRP > 10 (xg/mL) was very low (< 10%). Splenomegaly was significantly associated with increased parasitemia (P < 0.001) and CRP levels (P < 0.001), highlighting the importance of splenomegaly as an indicator of recent high density infection in this population. Multivariate analysis showed that CRP levels were significantly associated with splenomegaly, fever, hemoglobin, and age (P < 0.002). CRP levels also increased with increasing parasitemia (P < 0.001) but remained < 3.5 (xg/mL. The low levels of CRP indicate that children in the Amele modulate inflammation associated with malaria

Parametrically excited helicopter ground resonance dynamics with high blade asymmetries

The present work is aimed at verifying the influence of high asymmetries in the variation of in-plane lead-lag stiffness of one blade on the ground resonance phenomenon in helicopters. The periodical equations of motions are analyzed by using Floquet's Theory (FM) and the boundaries of instabilities predicted. The stability chart obtained as a function of asymmetry parameters and rotor speed reveals a complex evolution of critical zones and the existence of bifurcation points at low rotor speed values. Additionally, it is known that when treated as parametric excitations; periodic terms may cause parametric resonances in dynamic systems, some of which can become unstable. Therefore, the helicopter is later considered as a parametrically excited system and the equations are treated analytically by applying the Method of Multiple Scales (MMS). A stability analysis is used to verify the existence of unstable parametric resonances with first and second-order sets of equations. The results are compared and validated with those obtained by Floquet's Theory. Moreover, an explanation is given for the presence of unstable motion at low rotor speeds due to parametric instabilities of the second order

Ultrastructural plasma membrane asymmetries in tension and curvature promote yeast cell fusion.

Cell-cell fusion is central for sexual reproduction, and generally involves gametes of different shapes and sizes. In walled fission yeast Schizosaccharomyces pombe, the fusion of h+ and h- isogametes requires the fusion focus, an actin structure that concentrates glucanase-containing vesicles for cell wall digestion. Here, we present a quantitative correlative light and electron microscopy (CLEM) tomographic dataset of the fusion site, which reveals the fusion focus ultrastructure. Unexpectedly, gametes show marked asymmetries: a taut, convex plasma membrane of h- cells progressively protrudes into a more slack, wavy plasma membrane of h+ cells. Asymmetries are relaxed upon fusion, with observations of ramified fusion pores. h+ cells have a higher exo-/endocytosis ratio than h- cells, and local reduction in exocytosis strongly diminishes membrane waviness. Reciprocally, turgor pressure reduction specifically in h- cells impedes their protrusions into h+ cells and delays cell fusion. We hypothesize that asymmetric membrane conformations, due to differential turgor pressure and exocytosis/endocytosis ratios between mating types, favor cell-cell fusion

Sharp large time behaviour in n-dimensional Fisher-KPP equations

We study the large time behaviour of the Fisher-KPP equation ∂tu = ∆u+u−u2 in spatial dimension N, when the initial datum is compactly supported. We prove the existence of a Lipschitz function s∞ of the unit sphere, such that u(t, x) approaches, as t goes to infinity, the function Uc∗ ( |x| − c∗t + Nc+∗2 lnt + s∞(|xx| )) , where Uc∗ is the 1D travelling front with minimal speed c∗ = 2. This extends an earlier result of Gärtner

Design, fabrication, and delivery of a charge injection device as a stellar tracking device

Six 128 x 128 CID imagers fabricated on bulk silicon and with thin polysilicon upper-level electrodes were tested in a star tracking mode. Noise and spectral response were measured as a function of temperature over the range of +25 C to -40 C. Noise at 0 C and below was less than 40 rms carriers/pixel for all devices at an effective noise bandwidth of 150 Hz. Quantum yield for all devices averaged 40% from 0.4 to 1.0 microns with no measurable temperature dependence. Extrapolating from these performance parameters to those of a large (400 x 400) array and accounting for design and processing improvements, indicates that the larger array would show a further improvement in noise performance -- on the order of 25 carriers. A preliminary evaluation of the projected performance of the 400 x 400 array and a representative set of star sensor requirements indicates that the CID has excellent potential as a stellar tracking device

Condensation of the fusion focus by the intrinsically disordered region of the formin Fus1 is essential for cell-cell fusion.

Secretory vesicle clusters transported on actin filaments by myosin V motors for local secretion underlie various cellular processes, such as neurotransmitter release at neuronal synapses, &lt;sup&gt;1&lt;/sup&gt; hyphal steering in filamentous fungi, &lt;sup&gt;2&lt;/sup&gt; &lt;sup&gt;,&lt;/sup&gt; &lt;sup&gt;3&lt;/sup&gt; and local cell wall digestion preceding the fusion of yeast gametes. &lt;sup&gt;4&lt;/sup&gt; During fission yeast Schizosaccharomyces pombe gamete fusion, the actin fusion focus assembled by the formin Fus1 concentrates secretory vesicles carrying cell wall digestive enzymes. &lt;sup&gt;5-7&lt;/sup&gt; The position and coalescence of the vesicle focus are controlled by local signaling and actin-binding proteins to prevent inappropriate cell wall digestion that would cause lysis, &lt;sup&gt;6&lt;/sup&gt; &lt;sup&gt;,&lt;/sup&gt; &lt;sup&gt;8-10&lt;/sup&gt; but the mechanisms of focusing have been elusive. Here, we show that the regulatory N terminus of Fus1 contains an intrinsically disordered region (IDR) that mediates Fus1 condensation in vivo and forms dense assemblies that exclude ribosomes. Fus1 lacking its IDR fails to concentrate in a tight focus and causes cell lysis during attempted cell fusion. Remarkably, the replacement of Fus1 IDR with a heterologous low-complexity region that forms molecular condensates fully restores Fus1 focusing and function. By contrast, the replacement of Fus1 IDR with a domain that forms more stable oligomers restores focusing but poorly supports cell fusion, suggesting that condensation is tuned to yield a selectively permeable structure. We propose that condensation of actin structures by an IDR may be a general mechanism for actin network organization and the selective local concentration of secretory vesicles