Hydrologic Properties of Subarctic Organic Soils

Completion Report for U. S. Forest Service Institute of Northern Forestry Cooperative Agreement No. 16 USC 581; 581a-581iThe need for understanding the natural system and how it responds to various stresses is important; this is especially so in an environment where the climate not only sustains permafrost, but develops massive seasonal frost as well. Consequently, the role of the shallow surface organic layer is also quite important. Since a slight change in the soil thermal regime may bring about a phase change in the water or ice, therefore, the system response to surface alterations such as burning can be quite severe. The need for a better understanding of the behavior and properties of the organic layer is, therefore, accentuated. The central theme of this study was the examination of the hydrologic and hydraulic properties of subarctic organic soils. Summarized in this paper are the results of three aspects of subarctic organic soil examinations conducted during the duration of the project. First, a field site was set up in Washington Creek with the major emphasis on measuring numerous variables of that soil system during the summer. The greatest variations in moisture content occur in the thick organic soils that exist at this site. Our major emphasis was to study the soil moisture levels in these soils. This topic is covered in the first major section, including associated laboratory studies. Those laboratory studies include investigations of several hydraulic and hydrologic properties of taiga organic and mineral soils. Second, some field data on organic moisture levels was collected at the site of prescribed burns in Washington Creek to ascertain the sustainability of fires as a function of moisture levels. This portion of the study is described under the second major heading. The last element of this study was a continued application of the two-dimensional flow model that was developed in an earlier study funded by the U. S. Forest Service, Institute of Northern Forestry, and reported by Kane, Luthin, and Taylor (1975a). Many of the results and concepts gathered in the field work were integrated into the modeling effort, which is aimed at producing better estimates of the hydrologic effects of surface disturbances in the black spruce taiga subarctic ecosystem. This knowledge should also contribute to better fire management decisions of the same system.The work upon which this report is based was made possible by a cooperative aid agreement funded by the U. S. Forest Service, Institute of Northern Forestry, Fairbanks, Alaska. Contribution to this study was also made by Ohio State University

How Will the Greenhouse Industry Utilize Waste Heat?

Recent regulatory and economic change encourage waste heat use in the northern United States. In this article, the value of that form of energy to growers of greenhouse crops is assessed. It is found that production of rooted floricultural crops is likely to be the dominant activity at facilities supplied with waste heat. Waste heat utilization is unlikely to cause interregional relocation of vegetable production in the U.S

Comparison of Theoretical and Multi-Fidelity Optimum Aerostructural Solutions for Wing Design

As contemporary aerostructural research for aircraft design trends toward high-fidelity computational methods, aerostructural solutions based on theory are often neglected or forgotten. In fact, in many modern aerostructural wing optimization studies, the elliptic lift distribution is used as a benchmark in place of theoretical aerostructural solutions with more appropriate constraints. In this paper, we review several theoretical aerostructural solutions that could be used as benchmark cases for wing design studies, and we compare them to high-fidelity solutions with similar constraints. Solutions are presented for studies with 1) constraints related to the wing integrated bending moment, 2) constraints related to the wing root bending moment, and 3) structural constraints combined with operational constraints related to either wing stall or wing loading. It is shown that for each set of design constraints, the theoretical optimum lift distribution is consistently in excellent agreement with high-fidelity results. It follows that theoretical optimum lift distributions can often serve as a good benchmark for higher fidelity aerostructural wing optimization methods. Moreover, a review of solutions for the optimum wingspan and corresponding drag reveals important insights into the effects of viscosity, aeroelasticity, and compressibility on the aerodynamic and structural coupling involved in wing design and optimization

Alterations of T cell activation signalling and cytokine production by postmenopausal estrogen levels

<p>Abstract</p> <p>Background</p> <p>Immunosenescence is an age-associated disorder occurring primarily in T cell compartments, including altered subset composition, functions, and activation. In women, evidence implicates diminished estrogen in the postmenopausal period as a contributing factor to diminished T cell responsiveness. Since hypoestrogenism is present in postmenopausal women, our objective focused on whether T cell activation, defined as signalling molecule expressions and activation, and function, identified as IL-2 production, were affected by low estrogen.</p> <p>Methods</p> <p>Using Jurkat 6.1 T cells, consequences of 4 pg/ml (corresponding to postmenopausal levels) or 40 pg/ml (premenopausal levels) of estradiol (E₂) were analyzed on signalling proteins, CD3-zeta, JAK2, and JAK3, determined by Western immunoblotting. These consequences were correlated with corresponding gene expressions, quantified by real time-polymerase chain reaction. Tyrosine phosphorylation of CD3-zeta was defined by immunoprecipitation and western immunoblotting following activation by T cell receptor (TcR) cross-linking. CD3-zeta expression and modulation was also confirmed in T cells from pre- and postmenopausal women. To assess functional consequences, IL-2 production, induced by PMA and ionomycin, was determined using enzyme-linked immunosorbent spot assay (ELISpot).</p> <p>Results</p> <p>At 40 pg/ml E₂, the level of signalling protein CD3-zeta was elevated 1.57-fold, compared with cells exposed to 4 pg/ml E₂. The CD3-zeta proteins also exhibited altered levels of activation-induced phosphorylation in the presence of 40 pg/ml E₂versus 4 pg/ml: 23 kD phosphorylated form increased 2.64-fold and the 21 kD form was elevated 2.95-fold. Examination of kinases associated with activation signalling also demonstrated that, in the presence of 40 pg/ml E₂, JAK2 protein expression was increased 1.64-fold (p < 0.001) and JAK3 enhanced 1.79-fold (p < 0.001) compared to 4 pg/ml. mRNA levels for CD3-zeta, JAK2, and JAK3 were significantly increased following exposure to 40 pg/ml E₂(2.39, 2.01, and 2.21 fold, respectively) versus 4 pg/ml. These findings were confirmed in vivo, since T cells from postmenopausal women exhibited 7.2-fold diminished CD3-zeta expression, compared to pre-menopausal controls and this expression was elevated 3.8-fold by addition of 40 pg/ml E₂. Functionally, Jurkat cells exposed to 40 pg/ml E₂and activated exhibited significantly elevated numbers of IL-2 producing colonies compared to 4 pg/ml (75.3 ± 2.2 versus 55.7 ± 2.1 colonies, p < 0.0001).</p> <p>Conclusion</p> <p>Jurkat T cells exposed to 4 pg/ml E₂expressed significantly diminished activation signalling proteins, correlating with reduced IL-2 production. Lower signalling protein levels appear to result from decreased CD3-zeta, JAK2, and JAK3 gene expressions. These findings may provide a molecular basis for immunosenescence associated with the postmenopausal state.</p

Dielectric Fundamental Strings in Matrix String Theory

Matrix string theory is equivalent to type IIA superstring theory in the light-cone gauge, together with extra degrees of freedom representing D-brane states. It is therefore the appropriate framework in which to study systems of multiple fundamental strings expanding into higher-dimensional D-branes. Starting from Matrix theory in a weakly curved background, we construct the linear couplings of closed string fields to type IIA Matrix strings. As a check, we show that at weak coupling the resulting action reproduces light-cone gauge string theory in a weakly curved background. Further dualities give a type IIB Matrix string theory and a type IIA theory of Matrix strings with winding. We comment on the dielectric effect in each of these theories, giving some explicit solutions describing fundamental strings expanding into various Dp-branes.Comment: Plain LaTeX, 25 pages. Reference added. Version to appear to NP

Aerodynamic Centers of Arbitrary Airfoils Below Stall

The aerodynamic center of an airfoil is commonly estimated to lie at the quarter-chord. This traditional estimate is based on thin airfoil theory, which neglects aerodynamic and geometric nonlinearities. Even below stall, these nonlinearities can have a significant effect on the location of the aerodynamic center. Here, a method is presented for accurately predicting the aerodynamic center of any airfoil from known lift, drag, and pitching-moment data as a function of angle of attack. The method accounts for aerodynamic and geometric nonlinearities, and it does not include small-angle, small-camber, and thin-airfoil approximations. It is shown that the aerodynamic center of an airfoil with arbitrary amounts of thickness and camber in an inviscid flow is a single, deterministic point, independent of angle of attack, and lies at the quarter-chord only in the limit as the airfoil thickness and camber approach zero. Furthermore, it is shown that, once viscous effects are included, the aerodynamic center is not a single point but is a function of angle of attack. Differences between this general solution and that predicted by the thin airfoil theory can be on the order of 3%, which is significant when predicting flutter speeds. Additionally, the results have implications for predicting the neutral point of a complete aircraft

Numerical Algorithm for Wing-Structure Design

Low-fidelity aerostructural optimization routines have often focused on determining the optimal spanloads for a given wing configuration. Several analytical approaches have been developed that can predict optimal lift distributions on rectangular wings with a specific payload distribution. However, when applied to wings of arbitrary geometry and payload distribution, these approaches fail. Increasing the utility and accuracy of these analytical methods can result in important benefits during later design phases. In this paper, an iterative algorithm is developed that uses numerical integration to predict the distribution of structural weight required to support the bending moments on a wing with arbitrary geometry and payload distribution. It is shown that the algorithm’s predictions for the structural weight of a rectangular test wing match those found using an analytical approach. The structural weight distribution for a spanwise-constant non-structural weight distribution is also found. Coupling the algorithm with an optimization routine, the optimal lift distributions for the rectangular test wing are found and are shown to match analytical results. Finally, the optimal lift distributions for a test wing configuration with a spanwise-constant non-structural weight distribution are found using the algorithm

On The Interaction Of D0-Brane Bound States And RR Photons

We consider the problem of the interaction between D0-brane bound state and 1-form RR photons by the world-line theory. Based on the fact that in the world-line theory the RR gauge fields depend on the matrix coordinates of D0-branes, the gauge fields also appear as matrices in the formulation. At the classical level, we derive the Lorentz-like equations of motion for D0-branes, and it is observed that the center-of-mass is colourless with respect to the SU(N) sector of the background. Using the path integral method, the perturbation theory for the interaction between the bound state and the RR background is developed. We discuss what kind of field theory may be corresponded to the amplitudes which are calculated by the perturbation expansion in world-line theory. Qualitative considerations show that the possibility of existence of a map between the world-line theory and the non-Abelian gauge theory is very considerable.Comment: LaTeX, 28 pages, 4 eps figures. v2 and v3: eqs. (3.18) and (B.2) are corrected, very small change

Petrology and Geochemistry of Mafic Lavas near Glacier Peak, North Cascades, Washington

Major element, trace element, and mineral compositions have been determined for four Quaternary mafic monogenetic cinder cones and flows south of Glacier Peak, a dacitic stratovolcano in the northern Cascade arc. The flows are the Whitechuck basalt, and the basaltic andesites of Indian Pass, Lightning Creek, and Dishpan Gap. Whitechuck has high concentrations of AI2O3 (≥ 18 wt.%) and low concentrations of K2O (≤ 0.45 wt.%) and shares similar trace element characteristics with high alumina olivine tholeiites reported in the central and southern Cascades. The three basaltic andesites are calc-alkaline. Indian Pass and Lighting Creek have primitive compositions, with Mg# [100*Mg/(Mg+Fe*)] \u3e 65, Cr \u3e 200 ppm, and Ni \u3e 100 ppm. Most samples have olivine in equilibrium with bulk rock compositions. Rb and Sr are relatively low in most flows, especially at Whitechuck and Dishpan Gap. Sr and La decrease with increasing SiO2 in the Lightning Creek and Dishpan Gap cinder cones, indicating possible mixing with a Sr and La-poor felsic component represented by the most evolved Glacier Peak dacites. Petrographic observations of disequilibrium textures such as xenocrysts, xenoliths, quenched glass inclusions, and strongly-zoned phenocrysts in these two flows also indicate possible melting. All flows are enriched in large ion lithophile elements and light rare earth elements relative to high field strength elements, showing that the mantle beneath Glacier Peak has been fluxed by a hydrous subduction component. Ba/Nb ratios (~40-110) are highest for the three basaltic andesites, indicating that they had the greatest amount of subduction component enrichment. Nb and Ta abundances are highest at Indian Pass (Nb =~7 ppm) and lowest at Whitechuck (Nb = ~2-3), indicating that Indian Pass and the other two basaltic andesites were produced by relatively low degree hydrous melts of depleted mantle. In comparison, the Whitechuck basalts were produced by relatively dry (2O) slightly higher degree melting of a more depleted mantle (similar to NMORB) source. Of the three mantle-domains inferred beneath the Cascades, only a MORB-like mantle and a subduction-fluxed depleted mantle are represented beneath the Glacier Peak region. No OIB-like mantle domain is thus far represented in the Cascades north of the Mt. Rainier region

A Nonparametric Method for the Derivation of α/β Ratios from the Effect of Fractionated Irradiations

Multifractionation isoeffect data are commonly analysed under the assumption that cell survival determines the observed tissue or tumour response, and that it follows a linear-quadratic dose dependence. The analysis is employed to derive the α/β ratios of the linear-quadratic dose dependence, and different methods have been developed for this purpose. A common method uses the so-called Fe plot. A more complex but also more rigorous method has been introduced by Lam et al. (1979). Their method, which is based on numerical optimization procedures, is generalized and somewhat simplified in the present study. Tumour-regrowth data are used to explain the nonparametric procedure which provides α/β ratios without the need to postulate analytical expressions for the relationship between cell survival and regrowth delay