cssi/SciSciGPT-SciSciNet huggingface dataset:
A Simple Model-Free Method for Direct Assessment of Fluorescent Ligand Binding by Linear Spectral Summation

Fluorescent tagged ligands are commonly used to determine binding to proteins. However, bound and free ligand concentrations are not directly determined. Instead the response in a fluorescent ligand titration experiment is considered to be proportional to the extent of binding and, therefore, the maximum value of binding is scaled to the total protein concentration. Here, a simple model-free method is presented to be performed in two steps. In the first step, normalized bound and free spectra of the ligand are determined. In the second step, these spectra are used to fit composite spectra as the sum of individual components or linear spectral summation. Using linear spectral summation, free and bound 1-Anilinonaphthalene-8-Sulfonic Acid (ANS) fluorescent ligand concentrations are directly calculated to determine ANS binding to tear lipocalin (TL), an archetypical ligand binding protein. Error analysis shows that the parameters that determine bound and free ligand concentrations were recovered with high certainty. The linear spectral summation method is feasible when fluorescence intensity is accompanied by a spectral shift upon protein binding. Computer simulations of the experiments of ANS binding to TL indicate that the method is feasible when the fluorescence spectral shift between bound and free forms of the ligand is just 8 nm. Ligands tagged with environmentally sensitive fluorescent dyes, e.g., dansyl chromophore, are particularly suitable for this method.
NONIMPULSIVELY STARTED STEADY FLOW ABOUT A CIRCULAR CYLINDER

The effect of constant acceleration, prior to the establishment of a steady uniform flow, on some of the characteristics of the resulting time-dependent flow about a circular cylinder is investigated experimentally. It is shown that the occurrence of a local maximum drag, the onset of wake asymmetry, and the evolution of the transverse force are dependent on the parameters characterizing the nonimpulsive nature of the ambient flow.
The Central American Conflict: A Bibliography

Until recently, most North Americans thought of Central America as the land of bananas and exotic vacations. Today, government, media, and public concern are focused on the region's instability and the United States' role in it. This “crisis” in Central America has generated a barrage of publications. Perhaps an appropriate title for this article would have been “Central America: Crisis in the Library.” The growing number of publications on Central America is matched by growing demand for them in both public and academic libraries. This bibliography will help librarians build an adequate and balanced collection on Central America without having to locate and examine each book.
Potential impacts of long-term subsidence on the wetlands and evacuation routes in coastal Louisiana

A steady-state subsidence forecast model was developed as a proof of concept to estimate changes in surface elevations of the wetlands and evacuation routes across coastal Louisiana for the years 2015, 2025, 2050, and 2100. Subsidence estimates were derived from an empirical study published by the National Geodetic Survey. Forecasted vertical change was subtracted from current surface elevations. Land and evacuation routes estimated to have surfaces at or below 0 m in elevation, NAVD88, were quantified and classified as vulnerable to inundation hazards. The extent of the coastal zone susceptible to hurricane induced storm surge was also evaluated relative to surge models published by the National Weather Service. The results indicate spatially heterogeneous rates of subsidence that are forecasted to consume nearly 50 % of the existing coastal margin wetlands by 2100. The most significant rate increases are anticipated between 2015 and 2050. Relative to the impact on evacuation routes, subsidence occurring between the 2015 and 2025 forecast years expanded at slower rates when compared to the latter half of the century. Subsidence adjusted storm surge forecasts reveal similar patterns. The methods employed and findings produced demonstrate forecasting capabilities that provide emergency managers and transportation engineers with resources applicable to evacuation modeling, hazard mitigation, environmental sustainability research, costal restoration efforts, and more.
Translating orality in the postcolonial Arabic novel: A study of two cases of translation into English and French

This article explores the translation of orality in two postcolonial Arabic novels, namely Najīb Mahfūz's Awlād Hāratinā and Muhammad Shukrī's al-Khubz al-Hāfī, into English and French. It is argued that assimilation and non-assimilation of cultural aspects of foreign texts can have both positive and negative effects depending on the case examined. Specific examples are analyzed to show the various factors that can influence the way orality is translated as well as the hybridity of the methods used by the translators. This article further illustrates the complexity of evaluating assimilation and non-assimilation as they have an impact on linguistic, semantic, aesthetic, discursive, and cultural levels. It also sheds light on the translator's role by analyzing the effects of his/her interpretation and choices and the patterns detected in his/her work.
The electron microscopy of onion root tip cells

Abstract A series of electron micrographs has been made of thinly sectioned onion root tip fixed with several types of fixative and embedded in methacrylate. With acid fixation the cellular protoplasm appears shredded at these high magnifications, but after neutral fixation the cellular contents form continuous networks that indicate a better state of preservation at macromolecular dimensions. The electron micrographs show the fine structure of the protoplasm and chromosomes of cells in a number of stages of division. Prophase and telophase chromosomes appear to have a fibrillar structure which is no longer visible at metaphase and anaphase.
On the Search for Fundamental Performance Limitations in Fluid-Mechanical Systems

A simple pressure-based feedback control strategy for wall-transpiration control of incompressible unsteady 2D channel flow was recently investigated by Aamo, Krstic, & Bewley (2001). Nonlinear 2D channel flow simulations which implemented this control strategy resulted in flow transients with instantaneous drag far lower than that of the corresponding laminar flow. The present note examines the physical mechanism by which this very low level of instantaneous drag was attained. It then explores the possibility of achieving sustained drag reductions to below the laminar level by initiating such low-drag transients on a periodic basis. All attempts at sustaining the mean flow drag below the laminar level fail, providing further evidence in favor of the conjecture that the laminar state provides a fundamental “performance limitation” in such flows.Copyright © 2002 by ASME
The Effects of Levonantradol Hydrochloride on Tumor Growth and Therapy

The effects of levonantradol on tumor growth, both directly and in combination with the cytotoxic agent cyclophosphamide, were determined. Levonantradol hydrochloride administered alone had no effect on the progression of either murine sarcoma 180J or leukemia L-1210. Likewise, the increased survival obtained in both tumor systems with cyclophosphamide was not altered by concurrent administration of levonantradol hydrochloride. Levonantradol did not affect the incidence or extent of artificial melanotic lung metastases, nor did it modify lymphoreticular cell stimulation. These data support the use of levonantradol in conjunction with chemotherapy in cancer patients.
Fiber Kinematics of Small Intestinal Submucosa Subjected to Biaxial Stretch

Small intestinal submucosa (SIS) of the porcine has been used extensively over the past decade for repair of a variety of connective tissues, and is now being considered for functional tissue engineering applications. Thus, it is important to consider the kinematics of its fibers. The current study investigated the fiber kinematics of SIS in response to multiple stretch patterns using a modified version of a biaxial stretching device integrated with a small angle light scattering (SALS) apparatus (Billiar and Sacks 1997). Each sample was loaded to equibiaxial strain of 10% by stretching in each of the following stretch patterns: 1) first in the preferred fiber direction, then in the cross-preferred direction, 2) first in the cross-preferred direction, then in the preferred direction, and 3) simultaneously in both directions equally. The collagen fiber distributions for the equibiaxial strain states were found to be relatively insensitive to the stretch pattern. Further, an affine transformation calculation based on Lanir (1979) and Billiar and Sacks (1997) was used to predict the strip biaxial and equibiaxial collagen fiber distributions and it was found that while the tissue generally followed the trends expected for an affine material, the intensity levels were not predictive.Copyright © 2003 by ASME
On the Use of Boundary Layer Theory to Determine the Internal Circulation of Falling Drops

Abstract The standard boundary layer model for the flow past a circulating drop neglects the stress reduction caused by motion of the drop surface. A modified boundary layer model which incorporates this effect is presented, and is shown to yield good agreement with a numerical solution for the strength of the drop internal circulation.
A Game Theoretic Model for Farm Planning under Uncertainty

NCERTAINTY has long been recognized as an important aspect of farm planning. It was only recently, however, that different approaches to the problem of uncertainty in farm planning have been suggested [2, 5, 6, 7, 9]. These approaches employed techniques such as dynamic programming, game theory, quadratic programming, simulation, and stochastic linear programming. The game approach suggested by McInemey [5] was the first attempt that we have found in the farm management literature to incorporate farm constraints in a game against nature. McInerey's model, however, provides solutions only for the Wald maximin criterion. Decision criteria other than the Wald maximin may be more appealing to some farmers. This paper presents a model that incorporates farm constraints in a game against nature in a different manner from that of McInerney's model. The proposed model enables a farmer to obtain solutions for the maximin criterion and other decision criteria.
Selective inverse multiple bond analysis. A simple 1D experiment for the measurement of long-range heteronuclear coupling constants

The general concept of selective excitation is well established and the methodology has been utilized on numerous occasions in a wide range of applications. An interesting application of selective pulses has been in the development of selective analogues of two-dimensional NMR experiments. The first such effort germane to our work was that of Bax and Freeman ( 1)) in which they described the selective heteronuclear 2D J spectrum. Davis applied semiselective proton pulses to the Ha resonances of peptides (2) to establish long-range correlations to carbonyl resonances with high resolution in both frequency domains. In a paper published very shortly thereafter, Bermal and co-workers (3) described a group of two-dimensional pulse sequences intended to provide access to heteronuclear coupling constants that employed semiselective Gaussian 13C pulses. Kessler and colleagues have employed semiselective 13C pulses to improve the Fi resolution in proton-detected heteronuclear long-range correlation experiments (4). Supportive ancillary work has addressed the problem of extracting coupling constants from complex cross-peak multiplets observed in proton-detected heteronuclear correlation spectra (5, 6). The importance of measuring small heteronuclear coupling constants has not waned, as evidenced by recently reported heteronuclear two( 7, 8) and three-dimensional (9) studies designed to determine and utilize small heteronuclear coupling constants of biologically important molecules. In a departure from existing multidimensional methods, we report a simple, one-dimensional pulse sequence designed to allow the measurement of long-range heteronuclear coupling constants and to provide the means for establishing long-range heteronuclear connectivities. The earliest reports of one-dimensional analogs of two-dimensional NMR experiments were those of Berger ( IO, II), which were followed by the work of Kessler and colleagues (12, 13). In an extension of these efforts, we describe a one-dimensional analogue of the HMBC experiment ( 14)) for which we propose the acronym SIMBA (selective inverse multiple bond analysis). With this new experiment, each proton with a resolved long-range coupling to the selected carbon simultaneously appears in the resultant spectrum with an apparent
Shifting the Paradigm of Testosterone and Prostate Cancer: The Saturation Model and the Limits of Androgen-Dependent Growth

Context The traditional belief that prostate cancer (PCa) growth is dependent on serum testosterone (T) level has been challenged by recent negative studies in noncastrated men. Objective To provide an improved framework for understanding the relationship of PCa to serum T level that is consistent with current evidence and is based on established biochemical principles of androgen action within the prostate. Evidence acquisition A literature search was performed of publications dating from 1941 to 2008 that addressed experimental and clinical effects of androgens on prostate growth. Review of studies investigating the prostatic effects of manipulation of androgen concentrations in human and animal studies, and in PCa cell lines. Evidence synthesis Prostate growth is exquisitely sensitive to variations in androgen concentrations at very low concentrations, but becomes insensitive to changes in androgen concentrations at higher levels. This pattern is consistent with the observation that androgens exert their prostatic effects primarily via binding to the androgen receptor (AR), and that maximal androgen-AR binding is achieved at serum T concentrations well below the physiologic range. A Saturation Model is proposed that accounts for the seemingly contradictory results in human PCa studies. Changes in serum T concentrations below the point of maximal androgen-AR binding will elicit substantial changes in PCa growth, as seen with castration, or with T administration to previously castrated men. In contrast, once maximal androgen-AR binding is reached the presence of additional androgen produces little further effect. Conclusions The evidence clearly indicates that there is a limit to the ability of androgens to stimulate PCa growth. A Saturation Model based on androgen-AR binding provides a satisfactory conceptual framework to account for the dramatic effects seen with castration as well as the minor impact of T administration in noncastrated men.
Distributed Mass Damper System for Integrating Structural and Environmental Controls in Buildings

The writers recently proposed a new type of mass damper system to integrate structural and environmental control systems for buildings. External shading fins are used as mass dampers such that they can (1) control building energy consumption by adjusting the fins and, thus, the amount of sunlight entering the building; and (2) control structural movements by dissipating energy with the dampers during strong motions. Because shading fins are placed along the height of the building, the mass dampers are distributed along the building height instead of concentrated in one or a few locations like traditional tuned mass dampers (TMDs). The distributed mass damper (DMD) system is formulated and simulated for earthquake motions. Optimization is performed on damper parameters (i.e., masses, stiffness, and damping coefficients) of the passive DMD system to minimize structural responses. A near-optimal DMD system outperforms a single TMD system. The movable shading fins are also briefly discussed; they show a subst...
Placental villous hypermaturation is associated with idiopathic preterm birth

AbstractObjective: Pregnancy complications such as intra-amniotic infection, preeclampsia, and fetal intrauterine growth restriction (IUGR) account for most cases of preterm birth (PTB), but many spontaneous PTB cases do not have a clear etiology. We hypothesize that placental insufficiency may be a potential cause of idiopathic PTB.Methods: Secondary analysis of 82 placental samples from women with PTB obtained from a multicenter trial of repeat versus single antenatal corticosteroids. Samples were centrally reviewed by a single placental pathologist masked to clinical outcomes. The histopathologic criterion for infection was the presence of acute chorioamnionitis defined as neutrophils marginating into the chorionic plate. Placental villous hypermaturation (PVH) was defined as a predominance of terminal villi (similar to term placenta) with extensive syncytial knotting. Idiopathic PTB comprised a group without another known etiology such as preeclampsia, IUGR or infection.Results: Acute chorioamnionitis...
Unitals and ovals of symmetric block designs in LDPC and space-time coding

An approach to the design of LDPC (low density parity check) error-correction and space-time modulation codes involves starting with known mathematical and combinatorial structures, and deriving code properties from structure properties. This paper reports on an investigation of unital and oval configurations within generic symmetric combinatorial designs, not just classical projective planes, as the underlying structure for classes of space-time LDPC outer codes. Of particular interest are the encoding and iterative (sum-product) decoding gains that these codes may provide. Various small-length cases have been numerically implemented in Java and Matlab for a number of channel models.
Decision-making for intracranial aneurysm treatment: when to select surgery, and when to select endovascular therapy.

The optimal treatment of an intracranial aneurysm provides complete and permanent occlusion of the aneurysm without compromise of the parent artery or adjacent small arterial branches, and without inducing medical or neurological complications. The cost of the treatment, the length of hospital stay, and the duration of the convalescent period are additional factors to be taken into account when selecting treatment. With recent developments in interventional neuroradiology, both surgical clipping and endovascular embolization are reasonable options for many, if not most, intracranial aneurysms. Surgical treatment requires craniotomy under general anesthesia, brain retraction, exposure and isolation of the aneurysm neck with separation of adjacent small perforating vessels, and collapse of the neck of the aneurysm by a spring-loaded microclip. Endovascular therapy requires intra-arterial navigation (Fig 1) of a microcatheter into the aneurysm sac and deposition of embolic material (coils usually) to fill completely the aneurysm sac without compromising the parent artery. In certain cases, endovascular therapy involves permanent balloon parent artery occlusion (Fig 2) in the case of unclippable-uncoilable aneurysms. The anatomic and physiological impact of these two types of treatment are somewhat different, and because of this, neither technique is optimal for all patients or all types of aneurysms. It is important to understand the advantages and disadvantages of each technique when selecting the best modality for treatment.
Beyond stereotypes of IT professionals: implications for IT HR practices

IT professionals are complicated---managers need to go beyond stereotypes to truly understand them.
On optimality conditions for structured families of nonlinear programming problems

Optimality conditions for families of nonlinear programming problems inRn are studied from a generic point of view. The objective function and some of the constraints are assumed to depend on a parameter, while others are held fixed. Techniques of differential topology are used to show that under suitable conditions, certain strong second-order conditions are necessary for optimality except possibly for parameter values lying in a negligible set.
Involuntary treatment laws: one of the "talking points" after the Tucson shootings.

Edited by Marian W. Roman, PhDThe University of Tennessee, College of Nursing, Knoxville, Tennessee, USAAfter the January 2011 shootings in Tucson, Arizona, that resulted in 6 deaths and 13 injured...
National Agricultural Policies and Market Relations

The domestic agricultural policies of the United States and Canada have far more similarities than differences. Except for dairy products and sugar (and peanuts in the United States), both have price policies that keep market prices at moderate levels, at least by comparison with most other industrial countries. Both protect agricultural producers by direct payments for many products when market prices fall below some politically determined level. While the agricultures of both countries are dependent upon exports as a market outlet, both directly control the imports of some farm products, such as dairy and beef, and indirectly influence imports of other products through subsidizing their production. Thus, while both press for reductions in trade barriers by other nations, both follow some domestic and trade policies that are nearly as restrictive as those of the European Community and Japan. There are, of course, some differences in domestic policies. The Canadian Wheat Board has monopoly control over trade in grains produced in the Prairie Provinces and part of British Columbia, both internally and externally. Canada is currently relying on direct payments more extensively than the United States with substantial direct payments to producers of dairy products, sugar, beef, sheep, hogs, feed grains, soybeans, and a number of fruits and vegetables. In contrast to the United States, Canada makes a significant effort to limit dairy production while the United States undertakes to engage in supply management for the major grains and cotton. Agricultural economists should be more than a little chagrined that both countries now depend upon measures of production costs to determine price support or target levels. Few agricultural economists, if any, south of the border paid any attention when in 1975 the Canadians introduced changes in production costs into the formula determining their support levels. Thus, most of us were caught by surprise when the present U.S. administration and Congress so fully embraced cost of production as the primary guide to support or target levels. Our failure to understand that contagious diseases can move either way across the border left us incapable of mounting a defense against the use of an economically indefensible concept.
The USAEC heavy section steel technology program: Objectives and status

Abstract The Heavy Section Steel Technology (HSST) program is concerned with the primary vessels for water reactors with the main thrust being placed on the effects of flaws, material inhomogeneities and discontinuities on the behavior of the vessels under normal operating and accident conditions. Emphasis is placed on developing a technology that can be used to establish the margin of safety against failure of the vessels, particularly catastrophic vessel failure beyond the control of plant safety features. Fracture phenomena under the environmental conditions of interest and the effects of section thickness on the fracture behavior of the large reactor vessels are being examined through a systematic progression of specimen sizes up to the equivalent of a full section thickness of 12 in. The program will culminate in a series of simulated service tests in which deliberately flawed vessels of substantial thickness will be tested to fracture. In this paper the status of the various investigations will be presented and the significant accomplishments in each of the areas of investigation will be summarized.
Simulations of the solution structure of HIV-1 protease in the presence and absence of bound zinc

Zinc ions have been shown to inhibit human immunodeficiency virus type 1 (HIV-1) protease in vitro at neutral pH [Zhang et al. Biochemistry, 36, 8717 (1991)]. Kinetic data from this study support a reversible binding mechanism of zinc in the active site. Preliminary calculations of the ion–protein potential energy based on the geometry of the crystallographic structure [Wlodawer et al. Science, 245, 616 (1989)] are consistent with this proposed mechanism. To examine the structure of HIV-1 protease with zinc bound in the active site, molecular dynamics simulations in the presence and absence of zinc at this site have been carried out to 200 ps. These simulations suggest zinc remains stably bound to the catalytic aspartate residues without disruption of the dimer or significant alteration of the active site structure. These data are consistent with those observed by Zhang et al. (1991), and together give strong evidence that this is the binding site that leads to inactivation. A proposed model of zinc binding at the active site based on quantum mechanical calculations indicates Zn+2 coordination is monodentate with each catalytic aspartate, leaving at least two ligand positions potentially free (occupied by water molecules in the calculations). © 1994 by John Wiley & Sons, Inc.
Trajectories of Gaussian processes and interpolation of Banach spaces

Abstract We investigate a condition for a Gaussian process with trajectories in a Banach space E to actually have trajectories in a “more regular” Banach space E θ (0 . “More regular” here means that E θ is an interpolation space between E and some sub-space of the reproducing kernel Hilbert space of the process. As an illustration we give an interpolation-theoretic proof of Holder property for trajectories of some Gaussian processes related to a Wiener process.
Isolation of cDNAs that are differentially expressed between androgen‐dependent and androgen‐independent prostate carcinoma cells using differential display PCR

In the development of prostate cancer there is an important transition from androgen-dependent growth (which can be treated) to androgen-independent growth (which is beyond medical control). This transition is probably accompanied by genetic changes, resulting in the activation of oncogenes or the inactivation of tumor suppressor genes. In the present manuscript, the isolation of genes that may be involved in advanced, androgen-independent prostate cancer growth is described. Using differential display PCR, 13 cDNAs were isolated representing genes that are differentially expressed between the androgen-dependent prostate carcinoma cell line LNCaP and the androgen-independent prostate carcinoma cell lines PC-3 and DU 145. These clones were divided into four groups: androgen-responsive genes (TL5, TL25, TL32, and TL35); genes with a marked decreased expression in one of the prostate cancer cell lines (TL27); genes with a marked, increased expression in one or more of the prostate cancer cell lines (TL4, TL16, TL21, and TL22); and genes with minor (but repeatable) changes in expression between prostate cancer cell lines (TL7, TL15, TL18, and TL33). The 13 genes were analyzed for their sequence information, tissue specificity, and androgen responsiveness in order to identify genes of interest. In summary, differential display PCR appears to provide an attractive alternative to existing molecular techniques to screen for differentially expressed genes in prostate cancer cells.
Flipping a genetic switch by subunit exchange

The bacteriophage T4 AsiA protein is a multifunctional protein that simultaneously acts as both a repressor and activator of gene expression during the phage life cycle. These dual roles with opposing transcriptional consequences are achieved by modification of the host RNA polymerase in which AsiA binds to conserved region 4 (SR4) of σ70, altering the pathway of promoter selection by the holoenzyme. The mechanism by which AsiA flips this genetic switch has now been revealed, in part, from the three-dimensional structure of AsiA and the elucidation of its interaction with SR4. The structure of AsiA is that of a novel homodimer in which each monomer is constructed as a seven-helix bundle arranged in four overlapping helix–loop–helix elements. Identification of the protein interfaces for both the AsiA homodimer and the AsiA–σ70 complex reveals that these interfaces are coincident. Thus, the AsiA interaction with σ70 necessitates that the AsiA homodimer dissociate to form an AsiA–SR4 heterodimer, exchanging one protein subunit for another to alter promoter choice by RNA polymerase.
Understanding Preferences for Recycling Electronic Waste in California The Influence of Environmental Attitudes and Beliefs on Willingness to Pay

Increasing stockpiles of electronic waste (e-waste) combined with low recycling rates are threatening human and environmental health because of the hazardous materials in electronic products. To da...
Location of Substrate Binding Sites within the Integral Membrane Protein Microsomal Glutathione Transferase-1†

Microsomal glutathione transferase-1 (MGST1) is a trimeric, membrane-bound enzyme with both glutathione (GSH) transferase and hydroperoxidase activities. As a member of the MAPEG superfamily, MGST1 aids in the detoxication of numerous xenobiotic substrates and in cellular protection from oxidative stress through the GSH-dependent reduction of phospholipid hydroperoxides. However, little is known about the location of the different substrate binding sites, including whether the transferase and peroxidase activities overlap structurally. Although molecular density attributed to GSH has been observed in the 3.2 A resolution electron crystallographic structure of MGST1, the electrophilic and phospholipid hydroperoxide substrate binding sites remain elusive. Amide H-D exchange kinetics and H-D ligand footprinting experiments indicate that GSH and hydrophobic substrates bind within similar, but distinct, regions of MGST1. Site-directed mutagenesis, guided by the H-D exchange results, demonstrates that specific residues within the GSH footprint effect transferase activity toward 1-chloro-2,4-dinitrobenzene. In addition, cytosolic residues surrounding the chemical stress sensor C49 but not modeled in the crystal structure appear to play an important role in the formation of the binding site for hydrophobic substrates. Although the fatty acid/phospholipid binding site structurally overlaps that for GSH, it does not appear to be localized to the same region as other hydrophobic substrates. Finally, H-D exchange mass spectrometry reveals a specific conformational transition that may mediate substrate binding and/or product release. Such structural changes in MGST1 are essential for activation of the enzyme and are important for its biological function.
Effects of loading orientation on the morphology of the predicted yielded regions in trabecular bone

While the effects of bone mineral density and architecture in osteoporotic bone have been studied extensively, the micromechanics of yielding and failure have received less attention. However, understanding architectural features associated with failure should provide insight into assessing bone quality. In this study, microstructural finite element models were used to compute regions of tissue level yielding in ten bovine tibial trabecular bone samples. The morphology, number, and mean volume of the yielded regions were quantified for four apparent strains under two loading conditions. For on-axis loading, the mean aspect ratio of the tissue that yielded due to compressive strain increased with increasing apparent strain, expanding along the principal trabecular orientation. This suggests that tissue level yielding progresses along vertical trabeculae when a specimen is loaded on-axis. The number, but not the volume, of the regions yielded due to tensile strain increased with increasing applied load, consistent with relaxation and redistribution of stresses around the yielded regions. When the specimens were compressed perpendicular to the principal axis, the aspect ratio of the yielded regions was close to one, while the number, mean volume, and mean thickness of the yielded regions increased. This indicates that localized high strains consistent with bending rather than axial deformation of struts occur at the tissue level. Overall, the results provide new insight into trabecular bone failure, which is relevant to assessing diagnostic tests for fracture risk or evaluating osteoporosis treatments.
The Presenilin-1 ΔE9 Mutation Results in Reduced γ-Secretase Activity, but Not Total Loss of PS1 Function, in Isogenic Human Stem Cells

Presenilin 1 (PS1) is the catalytic core of γ-secretase, which cleaves type 1 transmembrane proteins, including the amyloid precursor protein (APP). PS1 also has γ-secretase-independent functions, and dominant PS1 missense mutations are the most common cause of familial Alzheimer's disease (FAD). Whether PS1 FAD mutations are gain- or loss-of-function remains controversial, primarily because most studies have relied on overexpression in mouse and/or nonneuronal systems. We used isogenic euploid human induced pluripotent stem cell lines to generate and study an allelic series of PS1 mutations, including heterozygous null mutations and homozygous and heterozygous FAD PS1 mutations. Rigorous analysis of this allelic series in differentiated, purified neurons allowed us to resolve this controversy and to conclude that FAD PS1 mutations, expressed at normal levels in the appropriate cell type, impair γ-secretase activity but do not disrupt γ-secretase-independent functions of PS1. Thus, FAD PS1 mutations do not act as simple loss of PS1 function but instead dominantly gain an activity toxic to some, but not all, PS1 functions.
An integrated active-passive soil moisture retrieval algorithm for SMAP for bare surfaces

An integrated soil moisture retrieval algorithm is presented in this work wherein both radar and radiometer measurements are used simultaneously to retrieve surface soil moisture. This method is applied to bare rough surfaces with varying soil moisture and roughness distributions. A thresholding method based on physical models of scattering and emission is presented to obtain equivalent estimated brightness temperatures from active radar measurements. This technique is used as a constraint to link active and passive data within the optimization scheme. Numerical simulations are performed to investigate the proposed inversion technique using the method of Simulated Annealing.
Computation of magnetic field in memdia with hysteresis

The vector Preisach hysteresis model is employed for the calculation of static magnetic fields in media with hysteresis. A time-stepping technique is used to trace a history of the magnetizing process. At each time step, a magnetization integral equation is employed, and a special technique for the solution of this equation is discussed. Theoretical considerations are illustrated by a numerical example. The attractive features of the model considered are its computational efficiency, ability to describe nonsymmetrical minor hysteresis loops, and the existence of well-developed identification procedures. >
Dihalocarbene insertion reactions into C-H bonds of compounds containing small rings: mechanisms and regio- and stereoselectivities.

Novel insertion reactions of dichloro- and dibromocarbene into carbon−hydrogen bonds adjacent to cyclopropane rings are reported. It is found that the predominant isomers formed in the reactions with bicyclo[4.1.0]heptane result from insertion into the endo carbon−hydrogen bonds alpha to the three-membered ring. In the reactions of bicyclo[3.1.0]hexane, however, the exo dihalocarbene insertion products are formed as the major isomers. In some compounds cyclopropane rings “activate” adjacent carbon−hydrogen bonds, whereas other systems containing three-membered rings do not. Moreover, the influence of various substituents (methyl, geminal dimethyl, phenyl, methoxy, and ethoxy) attached to bicyclo[3.1.0]hexane and bicyclo[4.1.0]heptane in dihalocarbene reactions has been studied. The findings can be explained by the concept of maximum orbital overlaps of Walsh orbitals of the cyclopropane rings and the α carbon−hydrogen bonds. In stark contrast, selective insertion into the tertiary carbon−hydrogen bonds of...
Binding of Mercurials to Membrane Suspensions and Undenatured Proteins

Binding capacities of membrane suspensions and dissolved compounds for mercurials were titrated by a new potentiometric method. Critical steps included a silver electrode of new design, the use of L-cysteine as a thiol buffer, a nitrogen atmosphere, and pretreatment of samples with equimolar mercurial and cysteine. Titrations had a sharp endpoint, accurate ±26 nmole methylmercury or ±8 nmole mercuric salt. Measurements of binding capacity of bovine serum albumin averaged 93% of the titer predicted for one SH group per molecule; those of human hemoglobin yielded 86-91% of the titer predicted for two SH groups per molecule. Yields dropped with exposure of protein solutions or membrane suspensions to atmospheric oxygen. Brain microsomes had significantly higher binding capacities (per milligram of protein) than red blood cell ghosts. The ratio of endpoint titers of CH3 HgCl to HgCl2 averaged 2:1 in assays of cysteine, proteins, and membranes, showing that the assay was free of denaturation artifacts and prot...
Theory of the four-photon parametric oscillator

The quantum statistics of parametric oscillation in a medium with cubic polarization is investigated in parametric approximation. Starting from an effective hamiltonian containing Bose operators of the signal, idler and pump mode and their coupling to heat baths, we obtain a c-number Fokker-Planck equation and the stochastically equivalent Langevin equations. These equations are solved, below threshold, well above threshold and near threshold. The linewidth of the signal and idler wave and their autocorrelation and crosscorrelation functions are calculated, characteristic differences between the four-photon and the three-photon parametric oscillators are discussed. The solution of the Fokker-Planck equation near threshold for a multimode pump laser is also obtained.
A NEW GENUS OF THE FAMILY DOLICHOPSYLLIDAE (SIPHONAPTERA) FROM CANADA

This new genus is apparently more closely related to the genus Dolichopsylla Baker 1906 than to any other known North American genus of Siphonaptera. But one specimen, a female, has been collected; however, it is so distinctive that the description of the genus is warranted.
Skeletal muscle fiber regeneration following heterotopic autotransplantation in cats.

Abstract Whole 3 g extensor digitorum longus (EDL) muscles of cats were autotransplanted. The EDL muscles were either transplanted without denervation prior to transplantation (normal transplants) or denervated 3 to 4 weeks prior to transplantation (pre-denervated transplants). A few peripheral skeletal muscle fibers survived transplantation but most fibers degenerated and then regenerated as the transplant became revascularized. Both normal and pre-denervated muscles regenerated successfully and by 50 days after transplantation fibers which had reinnervated showed high and low myofibrillar ATPase activity. Compared to controls, the smaller mean fiber cross-sectional area of the transplants was due to the large number of small fibers, but some fibers in the transplant were larger than any fibers observed in the controls. Transplants regained 57 percent of the muscle mass of the controls. Contraction and half relaxation times of transplanted muscles were slower than controls, but peak isometric tetanus tension per cm2 of muscle was nearly normal. Fifty to 170 days after transplantation, muscles showed low oxidative capacity and fatigued rapidly.
Practical electricity generation from a paper based biofuel cell powered by glucose in ubiquitous liquids

Abstract This paper introduces a novel enzymatic fuel cell design that employs cellulose paper-based quasi-2D microfluidic system to supply biofuel to the enzymatic layer. The state of the art nanoarchitectural design, employing carbon nanotube-based papers for the bioelectrodes, allows a single cell to maintain 400 mV for 16 days of continuous operation in glucose solution and reach 1 mA of current output. Stacks of cells connected in series show successful performance using glucose in Gatorade® resulting in stack-cell potential of 1.8 V, employed to power a digital clock for 36 h, continuously. These designs open the possibility for obtaining enzymatic fuel cells that can run small portable devices on easily available ubiquitous liquids while addressing environmental concerns that are prevalent in traditional fuel cells.
THE INTRASPLENIC INJECTION OF ESTROGENS AND THEIR ESTERS

EVIDENCE has been gradually accumulating from diverse lines of investigation which would indicate that the liver is the site of extensive estrogen inactivation. Several workers have demonstrated independently that of all animal tissues studied in vitro only liver slices and liver extracts are capable of completely inactivating estrogens (Zondek, 1941; Heller, 1940). Studies in vivo, comparing the activity of ovaries or pellets of estrogen implanted in the portal field with that of ovaries or pellets having venous drainage-into the systemic circulation, have also demonstrated that the liver is a major site of estrogen inactivation (Golden and Severinghaus, 1938; Biskind and Mark, 1939). There is, in addition, indirect evidence in that hepatotoxic agents apparently increase the effectiveness of endogenous and exogenous estrogens (Talbot, 1939; Pincus and Martin, 1940). On the other hand, Cantarow and his co-workers (1942 a, b) have presented evidence which they interpret as indicating that a major loss of e...
Linker Scanning Analysis of TBP Promoter Binding Factor DNA Binding, Activation, and Repression Domains *

The transcription activator TATA box-binding protein promoter-binding factor (TPBF) is both an activator and repressor of TBP gene expression in Acanthamoeba. TPBF bears little similarity to previously characterized families of factors. In order to identify domains that are involved in DNA binding, activation, and repression, we constructed several alanine linker scanning mutants and tested them for their ability to function in a variety of assays. The DNA binding domain comprises a large 100-amino acid domain within the central third of the protein, suggesting that DNA recognition is accomplished by interactions derived from several structural units within this domain. Surprisingly, transcription activation and repression are impaired by mutations within either of two discrete amino acid sequences located on either side of the DNA binding domain. These data suggest that TPBF activation and repression are accomplished by interactions with the same target. Since TATA elements can function bidirectionally, and in solution TBP can bind to TATA elements in either orientation, we propose that TPBF functions in part by orienting TBP or TFIID correctly on the TATA box.
Exchange coupled NiFe-TbCo thin films for use in self-biased magnetoresistive heads

It is found that the exchange field produced at the NiFe-TbCo interface has a maximum value at a TbCo layer composition of 27.5%. When proper sputtering conditions are used, this deposited composition produces an exchange field as large as 500 Oe when the layer is coupled to a 370-AA Permalloy layer. Torque and VSM data indicate that the TbCo layers have both in-plane and perpendicular anisotropy components and that the in-plane M-H loops of films that produce the maximum exchange field are square. A linear decrease in exchange field is observed as the NiFe layer thickness increases. The exchange field is independent of the TbCo layer thickness in the range of 1000-4000 AA. Films with a 500-AA layer of TbCo exhibited a greatly reduced exchange effect. A preliminary 500-AA-thick 128- mu m*20- mu m permalloy head biased with 2000 AA of TbCo exhibited at Delta R/R of 1.45%. The hard-axis coercivity is negligibly small ( 1 MHz. >
Laparoscopic radical parametrectomy and partial vaginectomy for recurrent endometrial cancer.

Abstract Background. Endometrial cancer recurrences in the vagina after surgery and radiation therapy are traditionally treated with pelvic exenteration. However, this operation is associated with significant morbidity and mortality, and thus alternative surgical options should be explored. Case. We present a case of laparoscopic resection of recurrent endometrial cancer at the vaginal apex in the setting of prior brachytherapy and 32 P intraperitoneal therapy. Conclusion. Laparoscopic radical parametrectomy and partial vaginectomy may be an option for patients with small central recurrences of endometrial cancer.
Perception of effort and respiratory sensitivity during exposure to ozone.

The purpose of this study was to examine the effects of exposure to the air pollutant ozone during exercise on perception of effort and to evaluate perceptual sensitivity to respiratory responses during this exposure. Fourteen male subjects were exposed to ozone concentrations of 000,030, and 0 50 p.p.m. during both resting and bicycle ergometer exercise treatments. Ratings of perceived exertion were obtained periodically during the 40min exercise period. Perceptual exponents were determined from magnitude estimation and production of lung volumes obtained before, at the approximate midpoint, and at the end of the 2 hour exposure period. Significant (p<0 01) decrements in FVC, FEV1, and MEF25-75 resulting from ozone exposure were greater immediately following an exercise bout. Perception of effort based on sensory input from above the waist (central) increased significantly (p<0 05) with increasing ozone concentrations. The increase in central perceived exertion appeared sooner in the exercise period and ...
Maintaining Mammalian Iron and Oxygen Homeostasis: Sensors, Regulation, and Cross-Talk

Though iron and oxygen are required to sustain essential biological processes, an excess of either can result in oxidative stress. Therefore, mammals tightly regulate cellular and systemic iron and oxygen homeostasis. At the cellular level, the hypoxia-inducible transcription factors (HIFs) are key mediators of oxygen homeostasis through their regulation of genes involved in anaerobic metabolism and oxygen delivery, among others. Iron regulatory proteins (IRPs) largely govern cellular iron homeostasis through their effects on the translation and stability of mRNAs involved in iron uptake, utilization, export, and storage. Here, we describe regulatory factors for each pathway that sense both iron and oxygen availability and coordinate the maintenance of mammalian iron and oxygen homeostasis at both the cellular and systemic levels.
Coupled physical-numerical analysis of flows in natural waterways

The recent digital-electronic revolution has helped experimental hydraulics benefit from a new generation of acoustic-, laser-, and imaging-based instrumentation. These newly developed techniques are not only of superior accuracy, but they have also expedited data collection. Powerful visualization software has been used increasingly to present and interpret experimental results. In addition, numerical models have become increasingly available in some cases providing turnkey solutions to complex flows. The outcome of this intensive development is powerful computer-based research tools that allow an unprecedented interaction between physical and numerical experiments. This integrated approach is considerably improving our understanding of numerous aspects and practical consequences of flow mechanics and allows a comprehensive treatment of space-time processes in fluid flows which is difficult to obtain using alternative means. This holistic experimental-numerical approach is readily available for integrati...