cssi/SciSciGPT-SciSciNet huggingface dataset:
The locking of 35° 〈1 1 0〉 dislocations in NiAl

Abstract Using high-resolution TEM, we observed the core structure of 〈1 1 0〉 dislocations in NiAl locked in 35° directions. These observations showed no evidence of climb decomposition. We conclude that the dislocations are not locked by climb decomposition but by the threefold core spreading of the large screw component of 35° 〈1 1 0〉 dislocations. In NiAl, 〈1 1 0〉 slip is more difficult than 〈1 1 1〉 slip because 〈1 1 0〉 dislocations are locked along two directions, whereas 〈1 1 1〉 dislocations are locked along the screw orientation only.
Brønsted acidic ionic liquids: the dependence on water of the Fischer esterification of acetic acid and ethanol

Initial studies involving the Fischer esterification of acetic acid utilizing task specific ionic liquid (TSIL) 1 and ethanol revealed an interesting trend when comparing overall conversions with the level of reuse. A rise in product yield was observed up to the third recycling of the ionic liquid (IL) medium. Post-run analyses revealed that the TSIL remained unchanged and the by-products of the reaction, acetic acid and water, were being retained. Use of TSILs in the Fischer esterification reaction was both high yielding and programmable if the proper ratio of both water and reagents to immobilized medium was observed.
Partial and complete reduction of O2 by hydrogen on transition metal surfaces

Abstract The metal-catalyzed reduction of di-oxygen (O2) by hydrogen is at the heart of direct synthesis of hydrogen peroxide (HOOH) and power generation by proton exchange membrane fuel cells. Despite its apparent simplicity, how the reaction proceeds on different metals is not yet well understood. We present a systematic study of O2 reduction on the (111) facets of eight transition metals (Rh, Ir, Ni, Pd, Pt, Cu, Ag, and Au) based on periodic density functional theory (DFT-GGA) calculations. Analysis of ten surface elementary reaction steps suggests three selectivity regimes as a function of the binding energy of atomic oxygen (BEO), delineated by the opposite demands to catalyze O–O bond scission and O–H bond formation: The dissociative adsorption of O2 prevails on Ni, Rh, Ir, and Cu; the complete reduction to water via associative (peroxyl, peroxide, and aquoxyl) mechanisms prevails on Pd, Pt, and Ag; and HOOH formation prevails on Au. The reducing power of hydrogen is decreased electrochemically by increasing the electrode potential. This hinders the hydrogenation of oxygen species and shifts the optimal selectivity for water to less reactive metals. Our results point to the important role of the intrinsic reactivity of metals in the selectivity of O2 reduction, provide a unified basis for understanding the metal-catalyzed reduction of O2 to H2O and HOOH, and offer useful insights for identifying new catalysts for desired oxygen reduction products.
Application of renormalization-group techniques to a homogeneous Bose gas at finite temperature

A homogeneous Bose gas is investigated at finite temperature using renormalization-group techniques. A nonperturbative flow equation for the effective potential is derived using sharp and smooth cutoff functions. Numerical solutions of these equations show that the system undergoes a second-order phase transition in accordance with universality arguments. We obtain the critical exponent {nu}=0.73. {copyright} {ital 1999} {ital The American Physical Society}
Component Balance in Mixed Lactic Starters as Influenced by Preservative Procedures

Abstract Relative storage efficiency of freezing at −20 C, lyophilization, and ultra-low temperature freezing (−196 C) in maintaining the component-strain balance of mixed lactic cultures was evaluated. Liquid nitrogen freezing, followed by lyophilization and freezing at −20 C, was the best preservative procedure for retaining the original strain balance and acid-producing ability of mixed lactic cultures.
On the Role of Interphases in the Transverse Failure of Fiber Composites

A numerical investigation into the effect of interphase properties on the transverse strength of unidirectional fiber-reinforced composites is carried out in the con text of plane strain linear elasticity. The phase geometry of the composite is modeled by a regular hexagonal array of fibers in a matrix, and the interphase behavior is represented by a constrained spring layer model. A variationally coupled finite element-boundary ele ment method is used to obtain the mechanical response of a cell containing a center fiber and parts of surrounding fibers. We assume matrix cracking to be the predominant mode of failure. It is demonstrated that the interphase properties significantly affect the overall cracking patterns. Issues regarding the strength and integrity of the composite are dis cussed.
Insulin and glucose regulation of glycogen synthase in rat calvarial osteoblastlike cells

Insulin has been shown to stimulate collagen, noncollagen protein and nucleic acid synthesis in bone cellsin vitro. However, the effects of insulin on intermediary carbohydrate metabolism in osteoblasts, and in particular on the key regulatory enzyme glycogen synthase, have not been directly examined. Accordingly, we developed a microassay for glycogen synthase (GS) to examine insulin and glucose regulation of this enzyme in cultured osteoblastlike cells. In osteoblast-enriched rat calvarial bone explants incubated for 24 hours in 5 mM glucose, insulin (0.1–100 nM) produced a dose-related stimulation of GSa (glucose-6-phosphate independent GS activity). The insulin-stimulated increase in GSa ranged from a 30% increase in the presence of 0.1 nM insulin to a 163% increase produced by 100 nM insulin, both significant atP<0.01. In contrast, GSb (glucose-6-phosphate dependent GS activity) was significantly increased only at a supraphysiologic insulin concentration (100 nM). The GS activity ratio (GSa/GSb) increased with insulin concentration from 0.1–100 nM. Basal values for GSa and GSb activity did not differ between explants incubated in 5mM or 15 mM glucose for 24 hours. However, incubation in the presence of 15 mM glucose blunted the insulin-stimulated increase in GSa activity, with 100 nM insulin producing only a 75% increase in GSa activity. In contrast, maximal insulin-stimulated GSb levels were not affected by high glucose medium. In explants incubated in glucose-free medium, basal GSa activity was significantly greater than in the presence of glucose. In addition, in explants incubated in the absence of glucose for 24 hours, 100 nM insulin produced a significant increase in GSa activity, demonstrating that exogenous glucose is not required for insulin stimulation of GS activity in the osetoblast. Therefore, both glucose and insulin regulate GS activity in osteoblastlike cells, and GS activity appears to be a highly sensitive marker for the effects of insulin on intermediary glucose metabolism in the osteoblast.
In vitro activity of moxifloxacin, a new 8-methoxyquinolone, against gram-positive bacteria.

Abstract The in vitro activity of moxifloxacin, formerly BAY 12-8039, against gram-positive bacteria was tested by the agar dilution method. A total of 189 isolates that included Staphylococcus aureus, Enterococcus faecalis, Enterococcus faecium, streptococci, rhodococci, leuconostocs, pediococci, lactobacilli, and diphtheroids were tested. Moxifloxacin showed greater potency than ciprofloxacin against S. aureus, streptococci, and enterococci, having Minimal Inhibitory Concentrations (MICs) lower than those of ciprofloxacin by 2- to 64-fold. This improved activity was most prominent for S. aureus. Moxifloxacin was active against Leuconostoc and Rhodococcus species. Time-kill studies using moxifloxacin at a concentration of 3 μg/mL against one isolate each of methicillin-resistant S. aureus (MSSA) (MIC, 0.031 μg/mL), MRSA (MIC, 1 μg/mL), two isolates of E. faecalis (MICs, 0.25 and 2 μg/mL), and two isolates of vancomycin-resistant E. faecium (MICs, 0.25 and 2 μg/mL) revealed an average decrease in colony forming unit (CFU) by 3.8, 0.4, 4.0, 2.0, 4.2, and 1.8 log 10 CFU/mL at 24 h, respectively. Moxifloxacin is a new 8-methoxyquinolone with improved in vitro activity against gram-positive bacteria. Further studies of the in vivo activity of this compound appear warranted.
A two-stage approach to multi-period allocation of savings among investment plans

This paper presents a two-stage multi-period decision model for allocation of the individual's savings into several investment plans. Although the U.S. economy is used as the background, the modelling methods are general enough to accommodate any tax law. The first stage of the model uses an asset-allocation method based on the single-index model. Because this method is static and does not provide for tax considerations and other constraints, it alone is not enough. The output of this optimal selection is used as exogenous parameters and controls for the second stage of the model which is an integer program. The IP includes fixed charges, statutory and budgetary constraints, a discount rate, and the risk level. We provide an example of this approach to illustrate how an individual can achieve his goals of terminal accumulations while maintaining the risk level, measured by the aggregate beta, he prefers. A linear programming relaxation of the IP model is utilized for sensitivity analysis to examine whether future adjustments in investment strategies are required. The model remains tractable enough for implementation by individuals who may not be experts in mathematical programming and financial planning.
Low power method for estimating the magnetization transfer bound‐pool macromolecular fraction

We present a practical method to estimate the magnetization transfer (MT) bound-pool fraction (M:). The method is based on a first-order approximation of the saturation equation and allows an in vivo estimate of M:, previously estimated only in vitro and requiring multiple (on the order of 10(2)) measurements. This method requires one saturation measurement, a T1 estimate, an accurate value for input power, and uses to advantage the low power limitations of clinical scanners. The approximation is shown to be feasible in expected tissue parameter ranges using simulations. Unlike the phenomenologic magnetization transfer ration (MTR), M: is a true tissue parameter representing the semisolid proton concentration involved in saturation transfer, allowing comparability of MT effect independent of input power, off-resonance frequency, or equipment.
C 60 nanoparticle quenching used as a biological label

Carbon 60 has been used in a functionalized form in a bioassay for a common herbicide, atrazine. It was found that the C60 is a very effective quencher of fluorescence from a number of common dyes. C60 was conjugated to atrazine for use in an immunoassay in which fluorescence from rhodamine was measured. Quenching of the rhodamine emission provided a detection scheme in this assay that yielded a very good limit of detection. The C60 quenching scheme can be used with a wide variety of fluorescent dyes, permitting the potential use of a range of small, cheap excitation sources.
Treatment of lethal cowpox virus respiratory infections in mice with 2-amino-7-[(1,3-dihydroxy-2-propoxy)methyl]purine and its orally active diacetate ester prodrug.

Abstract The acyclic purine nucleoside analog, 2-amino-7-[(1,3-dihydroxy-2-propoxy)methyl]purine (S2242) and its orally active diacetate ester prodrug (HOE961) were reported to be potent inhibitors of vaccinia virus replication in cell culture and in infected mice. These compounds were evaluated further, using infections with the related cowpox virus. Against a wild-type (WT) cowpox virus strain in mouse C127I cell culture, 50% effective concentrations (EC 50 , determined by plaque reduction assays) of S2242 and cidofovir (a positive control) were 3.5 and 1.0 μM, respectively. EC 50 values obtained against a cidofovir-resistant strain of the virus were 33 and 230 μM, respectively. Compounds were at least ten-fold less potent against WT virus in Vero cells than C127I cells. S2242 and cidofovir were 50% inhibitory to the proliferation of uninfected C127I cells at 340 and 180 μM, respectively, but neither compound inhibited Vero cell growth at 1000 μM. Mice were lethally infected with cowpox virus by intranasal inoculation, followed 24 h later by antiviral treatment for 5 consecutive days. Once or twice daily intraperitoneal (i.p.) treatments with either S2242 or HOE961 at 100 mg/kg per day resulted in ≥70 survival compared with no survivors in the placebo group. Lower doses of these compounds (10 and 30 mg/kg per day) were not protective, however. Cidofovir was 100% protective at 30 mg/kg per day. A 10-day course of treatment gave comparable survival results and demonstrated the oral efficacy of HOE961. Treatments with S2242 (100 mg/kg per day) and cidofovir (30 mg/kg per day) each reduced lung and nasal virus titers by approximately ten-fold, whereas, HOE961 (100 mg/kg per day) was less active. Overall, S2242 and HOE961 were found to be effective against cowpox virus infections in mice but were less potent than cidofovir. Since, HOE961 was orally active, it may have advantages over the other parenterally administered compounds for treating orthopoxvirus infections.
Complete fourier direct magnetic resonance imaging (CFD-MRI) for diffusion MRI

The foundation for an accurate and unifying Fourier based theory of diffusion weighted magnetic resonance imaging (DW-MRI) is constructed by carefully re-examining the first principles of DW-MRI signal formation and deriving its mathematical model from scratch. The derivations are specifically obtained for DW-MRI signal by including all of its elements (e.g., imaging gradients) using complex values. Particle methods are utilized in contrast to conventional partial differential equations approach. The signal is shown to be the Fourier transform of the joint distribution of number of the magnetic moments (at a given location at the initial time) and magnetic moment displacement integrals. In effect, the k-space is augmented by three more dimensions, corresponding to the frequency variables dual to displacement integral vectors. The joint distribution function is recovered by applying the Fourier transform to the complete high-dimensional data set. In the process, to obtain a physically meaningful real valued distribution function, phase corrections are applied for the re-establishment of Hermitian symmetry in the signal. Consequently, the method is fully unconstrained and directly presents the distribution of displacement integrals without any assumptions such as symmetry or Markovian property. The joint distribution function is visualized with isosurfaces, which describe the displacement integrals, overlaid on the distribution map of the number of magnetic moments with low mobility. The model provides an accurate description of the molecular motion measurements via DW-MRI. The improvement of the characterization of tissue microstructure leads to a better localization, detection and assessment of biological properties such as white matter integrity. The results are demonstrated on the experimental data obtained from an ex-vivo baboon brain.
Boundary recovery for Delaunay tetrahedral meshes using local topological transformations

Numerous high-quality, volume mesh-generation systems exist. However, no strategy can address all geometry situations without some element qualities being compromised. Many 3D mesh generation algorithms are based on Delaunay tetrahedralization which frequently fails to preserve the input boundary surface topology. For biomedical applications, this surface preservation can be critical as they usually contain multiple material regions of interest coherently connected. In this paper we present an algorithm as a post-processing method that optimizes local regions of compromised element quality and recovers the original boundary surface facets (triangles) regardless of the original mesh generation strategy. The algorithm carves out a small sub-volume in the vicinity of the missing boundary facet or compromised element, creating a cavity. If the task is to recover a surface boundary facet, a natural exit hole in the cavity will be present. This hole is patched with the missing boundary surface face first followed by other patches to seal the cavity. If the task was to improve a compromised region, then the cavity is already sealed. Every triangular facet of the cavity shell is classified as an active face and can be connected to another shell node creating a tetrahedron. In the process the base of the tetrahedron is removed from the active face list and potentially three new active faces are created. This methodology is the underpinnings of our LAST RESORT method. Each active face can be viewed as the trunk of a tree. An exhaustive breath and depth search will identify all possible tetrahedral combinations to uniquely fill the cavity. We have streamlined this recursive process reducing the time complexity by orders of magnitude. The original surfaces boundaries (internal and external) are fully restored and the quality of compromised regions improved.
On the use of consistent approximations in the solution of semi-infinite optimization and optimal control problems

We consider a pair consisting of an optimization problem and its optimality function (P,θ), and define consistency of approximating problem-optimality function pairs, (P N ,θ N ) to (P,θ), in terms of the epigraphical convergence of the P N to P, and the hypographical convergence of the optimality functionsθ N toΛ. We then show that standard discretization techniques decompose semi-infinite optimization and optimal control problems into families of finite dimensional problems, which, together with associated optimality functions, are consistent discretizations to the original problems. We then present two types of techniques for using consistent approximations in obtaining an approximate solution of the original problems. The first is a “filter” type technique, similar to that used in conjunction with penalty functions, the second one is an adaptive discretization technique that can be viewed as an implementation of a conceptual algorithm for solving the original problems.
Phase II trials of 5-day vinblastine infusion (NSC 49842), L-alanosine (NSC 153353), acivicin (NSC 163501), and aminothiadiazole (NSC 4728) in patients with recurrent or metastatic renal cell carcinoma.

One hundred and forty-four evaluable patients with recurrent or metastatic renal cell carcinoma (RCC) were treated with vinblastine infusion (n = 35), L-alanosine (n = 36), acivicin (n = 27), or aminothiadiazole (n = 46). Observed objective response rates of 9%, 3%, 4%, and 2%, respectively indicate that none of these agents has significant antineoplastic activity in recurrent or metastatic RCC. Multivariate analysis of survival data suggests that initial performance status, time from initial diagnosis to study entry, and the presence or absence of lung metastases are important prognostic factors for survival. After adjustment for these factors, treatment assignment was also seen to be of prognostic value. All four treatments were generally well tolerated. There were no reports of life-threatening or lethal toxicities; however, 37% of the patients experienced severe reactions to treatment, primarily myelosuppression, anemia, neuropathies, and mucositis.
Primary photophysical processes of discrete pseudotetrahedral oxovanadium centers dispersed in a silica xerogel matrix

The photophysical properties of discrete, catalytically relevant, oxovanadium (VO) sites dispersed in a transparent silica xerogel matrix have been measured by time-resolved techniques. The lowest excited state of this chromophore is a long-lived, emissive 3E state with phosphorescence lifetimes of ∼4 and ∼13 ms at room temperature and 14 K, respectively. The temperature dependence of the nonradiative decay rate from this state shows two well defined deactivation regions. A high frequency region occurring at T > 200 K with an activation energy of 2029 ± 171 cm−1 and a low frequency region at T < 200K with an activation energy of 43 ± 17 cm−1. It is suggested that the low frequency deactivation process is due to coupling between the oxovanadium chromophore and phonon modes of the silica matrix. The quantum yield for intersystem crossing from the high energy 1A1 singlet state to the triplet emissive state was also determined. This process proved to be very efficient with values of the intersystem crossing quantum yield approaching unity at 14 K and showing a weak temperature dependence over the range measured.
In vivo phenobarbital treatment increases protein binding to a putative AP-1 site in the CYP2B2 promoter

Phenobarbital (PB) is a potent inducer of cytochrome P450 enzymes, particularly CYP2B1/2B2. Although the mechanism(s) of PB induction of CYP2B1/2B2 is not fully understood, current research is focusing on the role PB may play in altering the binding of nuclear proteins to critical DNA response elements in the 5'-flanking region of these genes. In this study, rat liver nuclear proteins were analyzed for DNA binding ability using both a general consensus and a CYP2B2 sequence-specific AP-1 oligonucleotide. We demonstrate that in vivo PB treatment enhances protein binding activity to the consensus AP-1 oligonucleotide. Likewise, a putative AP-1 site, identified at -1441 in the CYP2B2 5'-flanking region, also formed a sequence specific DNA/protein complex which was enhanced after PB exposure. These data may support a role of AP-1 in the PB induction mechanism of CYP2B1/2B2.
Stereopsis from a performance perspective.

Purpose. A patient can demonstrate a poor stereoscopic test or task performance for reasons inherent within the test/task itself for reasons dependent on normal physiology common to all human subjects, and also for reasons that are outside of normal physiology and are unique or idiosyncratic to a particular person’s visual system. This article reviews the literature for the first two reasons, but emphasizes the pathophysiology involved in the idiosyncratic and abnormal reasons. Results. Using control systems analysis, it is shown that deficits in stereoscopic performance can be explained by reference to the quantitative aspect of stereoscopic threshold and qualitative aspects such as speed of response, reliability–robustness, and strength of percept. The relationship between fixation disparity and stereopsis is seen to be central to this explanation. Conclusions. Proceeding from diagnosis to treatment, control systems analysis offers physiologically based explanations for the corrective procedures necessary to ameliorate abnormal conditions. Several topics for applied research in stereopsis are suggested.
The design of 3D haptic widgets

D interaction with a computer is hard. As human interaction in the real world is quite dependent on haptics, we believe that adding haptics will alleviate many of the problems of 3D interaction with a computer. The naive approach to incorporating haptics would be to simply find existing objects and imitate them. This, however, would not seem to adequately leverage what is possible with a rea- sonably general force feedback device, as it does not take advantage of the ability to provide forces that are not physically based, or to simulate objects and behavior that could have been physically real- ized but weren't, or which would have been prohibitively difficult to physically realize. From our extensive experience with design- ing haptic computer user interfaces and using haptic interfaces in the real world we have abstracted from those interactions certain qualities which we present in this paper. In addition, this paper demonstrates how to use these qualities in the analysis and design of a suite of 3D haptic widgets, most of which are novel and many of which include non-physically based forces.
Error estimates using the cell discretization method for steady-state convection-diffusion equations

The cell discretization algorithm is applied to generate approximate solutions for some second-order non-self-adjoint elliptic equations. General convergence for homogeneous problems is shown by obtaining suitable error estimates. The method is applied using polynomial bases; this provides a nonconforming extension of the finite element method that can also produce the continuous approximations of an h-p finite element method. Numerical tests on convection-diffusion problems are made that confirm the theoretical estimates, and methods for dealing with boundary layer problems are illustrated.
Leading Coherent Professional Development: A Comparison of Three Districts

A comparison of three urban school systems suggests that district offices can influence teaching through professional development. District leaders can structure their programs to provide coherent and content-focused professional development. The district orientation (vision, emphasis on professional development, use of human resources) set by the dominant coalition of leaders—including but not limited to the superintendent—in each district influenced the coherence and content focus of the professional development programs. District differences in their organizational capacity affected coordination and planning of professional development. The district with the most coherent focus on helping teachers develop deeper knowledge about select subject areas had the greatest teacher-reported influence on teaching practice.
Digital content delivery in higher education: Expanded mechanisms for subordinating the professoriate and academic precariat

This paper suggests that the latest digital mechanisms for delivering higher education course content are yet another step in subordinating academic labor. The two main digital delivery mechanisms discussed in the paper are MOOCs and flexible option degrees. The paper advances the argument that, despite a relatively privileged position vis-a-vis other workers, academic cognitive laborers are caught up within and subject to some of the constraining and exploitative practices of capitalist accumulation processes. This capture within capitalist circuits of accumulation threatens to increase in velocity and scale through digital delivery mechanisms such as MOOCs and flexible option programs/degrees.
Pareto-improving congestion pricing on multimodal transportation networks

Abstract This paper determines a Pareto-improving pricing scheme for alleviating congestion in a multimodal transportation network that includes, e.g., transit services, high-occupancy/toll and general-purpose lanes. In this setting, a pricing scheme refers to a strategy for tolling roads and highways as well as adjusting fares on various transit lines. In addition, such a scheme is Pareto-improving if it maximizes the social benefit without increasing travel-related expense of stakeholders that include individual road users, transit passengers, transit operators, transportation authorities, etc. The user equilibrium and system optimum problem in the multimodal transportation network are discussed along with a model for determining Pareto-improving tolls. The latter is formulated as a mathematical program with complementarity constraints. Two numerical examples are presented to illustrate results from various models.
Application of distributed control to mitigate disturbance propagations in large power networks

During the past decades the electric power infrastructure has evolved into one of the largest and most complex systems due to its extreme dimension, geographic reach and high reliability requirements. Maintaining sufficient security margins requires major enhancement of the existing control. Particular emphasis should be placed on improving the ability of the system to survive extreme contingencies, triggered by very unlikely chains of events, but capable of propagating into widespread outages. In this paper, a distributed control scheme is proposed to mitigate disturbance propagations in large power networks. We find a linear state feedback that simultaneously optimizes a standard Linear Quadratic Regulator (LQR) cost criterion and induces a pre-defined communication structure. The proposed controller provides supplementary damping through the excitation of the generators. The main advantage of this approach lies in the limited communication and limited model information required for the design which makes it practically applicable for large scale systems. We use a large two-dimensional mesh structure test system with homogenous parameters, to demonstrate that the proposed controller performs almost as well as the optimal centralized control with far less amount of communication and computation. The choice of test system is due to the fact that electromechanical wave propagation behavior observed in actual power systems can be readily recognized in that structure.
Impact of a medical school course in clinical epidemiology and health care systems

Many physicians have inadequate knowledge of the science of medical decision making and the health care system. We tested the impact of a medical school course in Clinical Epidemiology and Health Services Delivery using a prospective cohort design with participants from two classes. A 15 item pre-test was given to second-year students followed by the course which covered clinical and classical epdemiology, research methodology, biostatistics and health services delivery. The questions were embedded in the final examination and were also administered to a subset of the class prior to graduation. In addition, the survey was completed just prior to graduation by randomly selected students from the class without the course. The average score increased from 29.2% before to 85.5% after the course and 65.3% at graduation (p < 0.01). The scores from the non-course class averaged 45.476, and were significantly lower than scores of those who had taken the course (p < 0.001). The course increased students' knowledge...
Impact of a confounding variable on a regression coefficient

Regression coefficients cannot be interpreted as causal if the relationship can be attributed to an alternate mechanism. One may control for the alternate cause through an experiment (e.g., with ra...
Wrist Arthroscopy: Standard Portals and Arthroscopic Anatomy

Wrist arthroscopy has become an indispensable tool for the hand surgeon. An effective arthroscopy is possible only with an appreciation for the surface anatomy, sound technique for establishing portals, and an understanding of intra-articular anatomy. This article reviews the radiocarpal, midcarpal, and special-use portals of wrist arthroscopy.
On the Fracture of Glass Which Is Subjected to Slowly Increasing Stress

A single number called the “strength” does not serve to describe adequately the fracture properties of glass subjected to a slowly increasing tensile stress. Instead, it is found that the surface where fracture originates may be represented as a continuum over which flaws of differing “critical breaking stresses” are distributed. The distribution function for the flaws is given by Sσ where σ is the tensile stress initiating fracture and S and b are constants which are properties of the surface for slowly increasing stresses. The testing procedure and nature of the flaws are discussed.
Loop Shaping with the Circle Criterion-Bode Plot with Application to Active Tape Steering

A drawback of the circle criterion for controller design for systems with memory-less nonlinearities is that it employs the Nyquist plot, for which frequency is an implicit variable. This paper presents a method for translating the circle criterion into allowable and forbidden regions on the Bode plot of a single-input/single-output system. This circle criterion-bode plot facilitates controller synthesis with loop shaping. The design concept is to shape the open loop response to avoid intersections between the forbidden regions and the magnitude and phase graphs. An application to the design of the controller for a lateral tape motion compensation system shows the utility of the plot.
NATURAL SELECTION AND AGE-STRUCTURED POPULATIONS

This paper studies the properties of a new class of demographic parameters for age-structured populations and analyzes the effect of natural selection on these parameters. Two new demographic variables are introduced: the entropy of a population and the reproductive potential. The entropy of a population measures the variability of the contribution of the different age classes to the stationary population. The reproductive potential measures the mean of the contribution of the different age classes to the Malthusian parameter. The Malthusian parameter is precisely the difference between the entropy and the reproductive potential. The effect of these demographic variables on changes in gene frequency is discussed. The concept of entropy of a genotype is introduced and it is shown that in a random mating population in Hardy-Weinberg equilibrium and under slow selection, the rate of change of entropy is equal to the genetic variance in entropy minus the covariance in entropy and reproductive potential. This result is an information theoretic analog of Fisher's fundamental theorem of natural selection.
''Filling-in'' colour in natural scenes

Our subjective experience of the world as being in full colour across the entire visual field is at odds with the highly fovea-biased distribution of cones in the retina. It is unclear how this percept of ‘‘pan-field colour’’ comes about. We use novel stimuli *‘‘colour chimeras’’ *to demonstrate a related visual phenomenon in which observers perceive rich colour throughout images with large achromatic regions. This percept appears to critically depend on natural scene statistics. By separately manipulating chromatic and structural content in such images, we demonstrate that both the spatial distribution of colour and the presence of recognizable scene structure contribute to the experience of pan-field colour in these stimuli. Our results suggest that this percept is unlikely to be due to a low-level colour spreading process. Instead, we suggest that mechanisms dependent on natural scenes’ chromatic and luminance statistics provide the basis for the phenomenon. It is remarkable that during everyday scene perception human observers subjectively experience a uniform visual world. The human retina is quite heterogeneous across its surface, both in terms of spatial acuity (Anstis, 1998) and the distribution of rods and cones (Roorda & Williams, 1999). Despite this variation in resolution and colour sensitivity, observers generally perceive uniformity in colour and focus throughout the visual field. Though ubiquitous to our visual experience, this very basic phenomenon has been little examined. In the current study, we direct our attention to the perception of what we call ‘‘pan-field colour’’, the name we give to the subjective experience of rich
Statistical emission of deuterons and tritons from highly excited compound nuclei

Statistical model calculations, employing optical model transmission coefficients for particle emission, have been able to describe in a satisfactory way {ital n}, {ital p}, {ital d}, {ital t}, and {alpha} emission properties of compound nuclei at excitation energies below 100 MeV. Recent experimental data have shown that the same model systematically overpredicts the deuteron and triton yields observed at higher excitation energies up to 405 MeV. The predictions of the statistical model with transmission coefficients derived from an ingoing-wave boundary condition and a direct reaction approach to fusion method are discussed. It is shown that a description of the deuteron and triton data is possible, provided that the corresponding inverse cross sections are reduced from the optical model predictions. For deuteron emission in particular, the required reduction is found to be consistent with experimental deuteron fusion cross sections. The breakdown of the traditional approach is attributed to the large percentage of nonfusion components contained in the optical model absorption cross section.
RIC: Ranking with Interaction Chains and Its Application in Computational Clinical Proteomics Studies

In clinical proteomics, a major goal is to identify important proteins in proteomics data that is based on biological samples. Using biological connections such as protein interactions that link directly or indirectly proteins from earlier studies with those in current proteomics studies, we propose a new algorithm called Ranking with Interaction Chains (RIC) to rank protein biomarker candidates. With RIC, we use statistical measures to set the best parameter values and applied it to proteomics-based breast cancer biomarker studies. Such ranking strategy may also be generalized where a functional priority score for each biomolecule can be computed from different Omics data types.
Reversi: Post-silicon validation system for modern microprocessors

Verification remains an integral and crucial phase of todaypsilas microprocessor design and manufacturing process. Unfortunately, with soaring design complexities and decreasing time-to-market windows, todaypsilas verification approaches are incapable of fully validating a microprocessor before its release to the public. Increasingly, post-silicon validation is deployed to detect complex functional bugs in addition to exposing electrical and manufacturing defects. This is due to the significantly higher execution performance offered by post-silicon methods, compared to pre-silicon approaches. Validation in the post-silicon domain is predominantly carried out by executing constrained-random test instruction sequences directly on a hardware prototype. However, to identify errors, the state obtained from executing tests directly in hardware must be compared to the one produced by an architectural simulation of the designpsilas golden model. Therefore, the speed of validation is severely limited by the necessity of a costly simulation step. In this work we address this bottleneck in the traditional flow and present a novel solution for post-silicon validation that exposes its native high performance. Our framework, called Reversi, generates random programs in such a way that their correct final state is known at generation time, eliminating the need for architectural simulations. Our experiments show that Reversi generates tests exposing more bugs faster, and can speed up post-silicon validation by 20x compared to traditional flows.
Soil drying and nitrogen availability modulate carbon and water exchange over a range of annual precipitation totals and grassland vegetation types.

Increased intensity in precipitation events and longer periods of water deficit are predicted as a general trend under future climate scenarios with potentially large effects on terrestrial ecosystem function. The primary objective of this study was to understand how variation in the intensity of precipitation inputs followed by intermittent soil drying events influence leaf and ecosystem carbon dioxide (CO2) and water exchange in a California annual grassland mesocosm experiment. We further examined how nitrogen (N) availability, and differences in plant community composition (grass-forb combinations) affected gas exchange responses to the precipitation treatments. Net ecosystem CO2 exchange (NEE) and evapotranspiration (ET) increased significantly with greater precipitation and were positively correlated with soil moisture. A repeated 10-day soil drying period, following 11 days of watering, strongly depressed NEE over a range of annual precipitation totals (297, 657 and 987mm), and plant community types. Ecosystem dark respiration (Re) and leaf level photosynthesis (Amax) showed greater sensitivity to periods of soil drying in the low precipitation plots (297mm). N additions significantly increased NEE and Re, particularly as water availability was increased. Across the range of precipitation totals and plant community types, intermittent periods of soil moisture deficit and native soil N availability constrained leaf and ecosystem level CO2 exchange, while the influence on water vapor exchange was less pronounced.
On the capacity of multiple unicast sessions in undirected graphs

Li and Li conjectured that in an undirected network with multiple unicast sessions, network coding does not lead to any coding gain. Surprisingly enough, this conjecture could not so far be verified even for the simple network consisting of K/sub 3,2/ with four source-sink pairs. Using entropy calculus, we provide the first verification of the Li-Li conjecture for this network. We extend our bound to the case of an arbitrary directed bipartite network.
Discovery of plastoquinones: a personal perspective

The discovery and the rediscovery of plastoquinone (PQ) are described together with the definition of its structure as a 2,3-dimethyl 5 solanosyl benzoquinone. The discovery, by M. Kofler, was a result of a search for Vitamin K. Its rediscovery was made by me, when I was at The Enzyme Institute of the University of Wisconsin, analyzing animals and plants for the newly discovered coenzyme Q. In green plants, I found another lipophilic quinone in addition to coenzyme Q. Some misleading evidence suggested as if the new quinone had coenzyme Q activity in mitochondria, but improved methods gave negative results. When I found that the quinone was concentrated in chloroplasts, I considered a role for it in photosynthesis analogous to the role of coenzyme Q in mitochondria. After moving to the Chemistry Department, University of Texas at Austin, I used a plain light bulb and some spinach chloroplasts to show that PQ could be involved in photosynthetic redox reactions. This effect was supported by Norman Bishop’s restoration of chloroplast electron transport after solvent extraction, with PQ and photoreduction studies by E. R. Redfern and J. Friend in R. A. Morton’s laboratory in Liverpool, UK. We also found an additional analog of PQ in addition to a second analog found in Wisconsin. We called the new analogs PQB and PQC. Although we found some restoration effects with PQC, the discovery by W. T. Griffiths in Morton’s laboratory, that PQB and PQC consisted of six forms of PQ each, made it more likely that the new analogs were breakdown products. Morton’s group established the structure of the PQCs as a series of PQs, with a hydroxyl group on the prenyl side chain, and the PQB series as having fatty acids esterified to the hydroxyl groups of PQC. Possible functions of the analogs are also discussed in this article.
Robotics and automation applications of drives and converters

The current design limits of power electronics have a significant effect on robotics and automation applications of drives and converters. This paper treats the major design limits that include dynamic range, reliability of power electronics, precision engineering and reliability, productivity and reliability, and drive motion control standards. For each of these limits, the paper identifies and discusses the salient issues and relates them to promising new technologies and, thus, to the future challenges in power electronic systems.
Pdd1p associates with germline-restricted chromatin and a second novel anlagen-enriched protein in developmentally programmed DNA elimination structures

Programmed DNA rearrangements, including DNA diminution, characterize the differentiation of somatic from germline nuclei in several developmental systems. Pdd1p (Programmed DNA degradation protein 1), a development-restricted polypeptide, has been implicated in heterochromatin assembly and DNA degradation during ciliate macronuclear development. Here, cross-linking and co-immunoprecipitation were used to verify that Pdd1p-associated chromatin is enriched in germline-restricted DNA. Pdd1p-associated proteins include general core histones and a second anlagen-enriched polypeptide (Pdd2p, formerly known as p43). Immunoblotting analyses demonstrate that, like Pdd1p, Pdd2p is developmentally regulated and present in conjugating cells during the time of germline DNA rearrangements and degradation. Pdd2p is post-translationally modified by phosphorylation at a time in development corresponding to dephosphorylation of Pdd1p and the formation of heterochromatic DNA elimination structures. Following gene cloning, the derived amino acid sequence of the PDD2 gene predicts a novel polypeptide containing multiple putative phosphorylation sites. In situ analyses, using both light and electron microscopy, demonstrate that Pdd1p and Pdd2p co-localize in DNA elimination structures within developing macronuclei. However, unlike Pdd1p, which also localizes to apoptotic macronuclei, Pdd2p appears to be restricted to a higher degree to germline DNA elimination structures. Taken together, the data presented here demonstrate a physical link between Pdd1p and germline-restricted chromatin and establish Pdd2p as the second member of a small group of developmentally restricted polypeptides implicated in programmed DNA elimination.
Impact of very low physical activity, BMI, and comorbidities on mortality among breast cancer survivors

The purpose of this study was to examine post-diagnosis BMI, very low physical activity, and comorbidities, as predictors of breast cancer-specific and all-cause mortality. Data from three female US breast cancer survivor cohorts were harmonized in the After Breast Cancer Pooling Project (n = 9513). Delayed entry Cox proportional hazards models were used to examine the impact of three post-diagnosis lifestyle factors: body mass index (BMI), select comorbidities (diabetes only, hypertension only, or both), and very low physical activity (defined as physical activity <1.5 MET h/week) in individual models and together in multivariate models for breast cancer and all-cause mortality. For breast cancer mortality, the individual lifestyle models demonstrated a significant association with very low physical activity but not with the selected comorbidities or BMI. In the model that included all three lifestyle variables, very low physical activity was associated with a 22 % increased risk of breast cancer mortality (HR 1.22, 95 % CI 1.05, 1.42). For all-cause mortality, the three individual models demonstrated significant associations for all three lifestyle predictors. In the combined model, the strength and significance of the association of comorbidities (both hypertension and diabetes versus neither: HR 2.16, 95 % CI 1.79, 2.60) and very low physical activity (HR 1.35, 95 % CI 1.22, 1.51) remained unchanged, but the association with obesity was completely attenuated. These data indicate that after active treatment, very low physical activity, consistent with a sedentary lifestyle (and comorbidities for all-cause mortality), may account for the increased risk of mortality, with higher BMI, that is seen in other studies.
Visiting the Neo-Liberal University: New Public Management and Conflicting Normative Ideas. A Danish Case.

At Danish universities, the governance structure is regulated by law. This structure was radically changed in 2003, abolishing the republican rule of the senate consisting of academics, students, and staff in favour of an authoritarian system assigning all executive power to the vice-chancellor, or as we say in Denmark, the rector. To introduce the current situation at Danish universities, in the first two sections of this article, I will compare them with more well-known counterparts in other countries. This situation is reflected in exemplary cases, and in the third section, I focus on the most dramatic controversy ever encountered at a Danish university, the Koldau case, which reached national newspaper headlines and broadcasting in two rounds in 2011 and 2012. In the fourth section, I will interpret the case as an educational controversy in light of two conflicting ideas of the modern university, which may be attributed to two leading Enlightenment figures, Wilhelm von Humboldt and Denis Diderot. The conclusion is that to some extent, 1 Sorensen: Visiting the Neo-Liberal University Published by Western CEDAR, 2015 the failure to resist the neo-liberal university reforms in Denmark and the UK, and the drama of the Koldau case, may be explained with reference to the conflicting ideologies of those involved in these controversies.
The Evaluation of Summations with Binomial Coefficients

(1961). The Evaluation of Summations with Binomial Coefficients. Mathematics Magazine: Vol. 34, No. 3, pp. 161-163.