cssi/SciSciGPT-SciSciNet huggingface dataset:
Toplogy Design and Optimization of Nonlinear Metamaterials

We consider topology optimization of lumped and continuous nonlinear metamaterial systems. Structures that consist of alternating layers of material with high impedance contrast are a simple example of a continuous phononic crystal that may exhibit nonlinearity. Analysis of this system, subject to prescribed constraints, shows that optimal design for a bilayered system consists of a thin nonlinear layer. Optimal, in this context, refers to a design which maximizes the frequency shift (and thus bandgap shift) at the edge of the first Brillouin Zone for the acoustic branch. Computer simulations of this system validate the predicted dispersion behavior. Optimization of two-dimensional arrays is presented using lumped-parameter models with nonlinear spring elements. Pattern-search algorithms identify topology (discrete mass distributions) that produce large increases in complete bandgap width. The analytical expression used in calculating nonlinear frequency shifts reveals that the largest contributions to the frequency shift are primarily produced from the resonant components of the system. Optimizing continuous multidimensional unit cells using a commercial finite-element code is briefly addressed.Copyright © 2012 by ASME
Dextran and Insulin in Rats

WHILE testing the effects of insulin on the circulatory reaction of laboratory rats to dextran, we found that many animals died after combined doses of the two agents which were not lethal when administered separately. The validity of this observation was put to experimental test. Male Sprague-Dawley rats weighing at least 150 gm. and fasted 24 hr. were sub-cutaneously injected with zinc insulin (‘Iletin’) at two dose-levels, 7.5 or 10 U./kgm. body-weight. An hour later dextran was administered by vein in a total volume of 10 ml./kgm. 0.85 per cent sodium chloride containing either 60 or 600 mgm. dextran (‘Expandex’). Control animals received saline without dextran. Fatalities due to these amounts of dextran have not occurred in our work. The results of eight experiments are summarized in Table 1, which shows the incidence of survival after 24 hr. Animals that died exhibited convulsions usually within 3 hr. of insulin administration. Few signs of the dextran reaction characteristic of this species were noticed.
Electrochemical oxidation of 6,8-dioxypurine

Abstract The electrochemical oxidation of 6,8-dioxypurine has been studied in aqueous solution at graphite electrodes. At pH 2.0 the single voltammetric oxidation peak observed corresponds at a 2 e− −2 H+ oxidation of 6,8-dioxypurine to a very unstable quinonoid which is attacked by water to give a 4,5-diol intermediate. The latter diol can be observed using thin-layer spectroelectrochemistry and has been isolated using HPLC techniques. The diol is hydrolyzed in solution to 5-(N-formyl)carboxamide-5-hydroxyhydantoin which in turn decomposes to 5-hydroxyhydantoin-5-carboxylic acid and 5-hydroxyhydantoin-5-carboxamide. Hypoxanthine is electrochemically oxidized at more positive potentials to 6,8-dioxypurine which is immediately further oxidized to the latter products. At pH 7.0 the oxidation of 6,8-dioxypurine follows a similar pathway to that at pH 2.0. In the case of hypoxanthine at pH 7.0 the major oxidation reaction appears to proceed by initial formation of 6,8-dioxypurine but alternative minor routes are also apparently available.
Chromogranin A does not mediate glucocorticoid inhibition of adrenocorticotropin secretion

It has recently been proposed that chromogranin A (CgA), a 50-kilodalton acidic glycoprotein that is costored and cosecreted with hormones and neurotransmitters in a variety of tissues, mediates glucocorticoid inhibition of ACTH secretion from AtT20/D16v mouse anterior pituitary corticotroph tumor cells by an undefined autocrine mechanism. We used AtT20/D16v cells, RIAs for murine CgA and ACTH, complementary DNA probes for CgA and POMC, the precursor of ACTH, antiserum that reacts with murine CgA, highly purified bovine CgA, and synthetic rat and porcine pancreastatin, a bioactive cleavage product of CgA in some systems, to study the kinetics of the effect of glucocorticoids on CgA and ACTH synthesis and secretion and of CgA's subsequent effects on ACTH secretion. Exposure to 100 nM dexamethasone (DEX) did not alter the size of CgA or POMC messenger RNA (mRNA) transcripts but increased cell CgA mRNA content 42% by 3 h and 192% by 48 h. DEX decreased cell POMC mRNA content 22% by 6 h and 57% by 48 h. These...
Development of a Telerobotic System to Assist Persons With Disabilities

This paper describes the development of intelligent mapping from a haptic user interface to a remote manipulator to assist individuals with disabilities performing manipulation tasks. This mapping, referred to an assistance function, is determined on the basis of environmental model or sensory data to guide the motion of a telerobotic manipulator while performing a given task. Human input is enhanced rather than superseded by the computer. Three manual dexterity assessment tests commonly used in occupational therapy field were chosen to implement several forms of assistance functions designed to augment the human performance. The test bed used for these tasks consisted of a six-degree-of-freedom force-reflecting haptic interface device, PHANToM with the GHOST SDK Software. One of the tests was chosen to be implemented in a real telerobotic system consisting of the haptic device as a Master and the Robotics Research Corporation manipulator (RRC K-2107) with a vision system and laser range data as a Slave. The results demonstrated that the forms of assistance provided reduced the execution times and increased the performance of the chosen tasks. In addition, these results suggest that the introduction of the haptic rendering capabilities, including the force feedback, offers special benefit to motion-impaired users by augmenting their performance on job-related tasks.Copyright © 2002 by ASME
Stretched exponential relaxation arising from a continuous sum of exponential decays

Stretched exponential relaxation of a quantity $n$ versus time $t$ according to $n={n}_{0}\phantom{\rule{0.2em}{0ex}}\mathrm{exp}[\ensuremath{-}{({\ensuremath{\lambda}}^{*}t)}^{\ensuremath{\beta}}]$ is ubiquitous in many research fields, where ${\ensuremath{\lambda}}^{*}$ is a characteristic relaxation rate and the stretching exponent $\ensuremath{\beta}$ is in the range $0l\ensuremath{\beta}l1$. Here we consider systems in which stretched exponential relaxation arises from global relaxation of a system containing independently exponentially relaxing species with a probability distribution $P(\ensuremath{\lambda}∕{\ensuremath{\lambda}}^{*},\ensuremath{\beta})$ of relaxation rates $\ensuremath{\lambda}$. We study the properties of $P(\ensuremath{\lambda}∕{\ensuremath{\lambda}}^{*},\ensuremath{\beta})$ and their dependence on $\ensuremath{\beta}$. Physical interpretations of ${\ensuremath{\lambda}}^{*}$ and $\ensuremath{\beta}$, derived from consideration of $P(\ensuremath{\lambda}∕{\ensuremath{\lambda}}^{*},\ensuremath{\beta})$ and its moments, are discussed.
End user behavior on an online information retrieval system: a computer monitoring study

We report on a computer monitoring study of users of the Ohio State University Libraries' online catalog, an established and heavily used information retrieval system. To our knowledge, this is the first monitoring study of an online catalog performed without system-defined user sessions. Online catalogs represent a class of retrieval systems which are designed for end users, require little or no formal training, and replace an existing manual system. The study characterizes user behavior in terms of types of searches done, patterns of use, time spent on searching, errors, and system problems. Preliminary results suggest that users have much shorter sessions than on other types of retrieval systems. Patterns of use vary between campus libraries, academic quarters, and between short and long sessions. Results of the study will be applied to improving the user interface and other system features.
Clinical Features of Bacterial Vaginosis in a Murine Model of Vaginal Infection with Gardnerella vaginalis

Bacterial vaginosis (BV) is a dysbiosis of the vaginal flora characterized by a shift from a Lactobacillus-dominant environment to a polymicrobial mixture including Actinobacteria and Gram-negative bacilli. BV is a common vaginal condition in women and is associated with increased risk of sexually transmitted infection and adverse pregnancy outcomes such as preterm birth. Gardnerella vaginalis is one of the most frequently isolated bacterial species in BV. However, there has been much debate in the literature concerning the contribution of G. vaginalis to the etiology of BV, since it is also present in a significant proportion of healthy women. Here we present a new murine vaginal infection model with a clinical isolate of G. vaginalis. Our data demonstrate that this model displays key features used clinically to diagnose BV, including the presence of sialidase activity and exfoliated epithelial cells with adherent bacteria (reminiscent of clue cells). G. vaginalis was capable of ascending uterine infection, which correlated with the degree of vaginal infection and level of vaginal sialidase activity. The host response to G. vaginalis infection was characterized by robust vaginal epithelial cell exfoliation in the absence of histological inflammation. Our analyses of clinical specimens from women with BV revealed a measureable epithelial exfoliation response compared to women with normal flora, a phenotype that, to our knowledge, is measured here for the first time. The results of this study demonstrate that G. vaginalis is sufficient to cause BV phenotypes and suggest that this organism may contribute to BV etiology and associated complications. This is the first time vaginal infection by a BV associated bacterium in an animal has been shown to parallel the human disease with regard to clinical diagnostic features. Future studies with this model should facilitate investigation of important questions regarding BV etiology, pathogenesis and associated complications.
SU‐E‐T‐694: Correlation Between Geometric Information and Dose Fractionation in Lung SBRT Treatment Plans

Purpose: Previously, a database‐driven decision support tool to assist clinical staff in assessing and improving lung SBRT treatment plans was developed. Using planning data collected by this software, we determined a simple metric that can be used for early identification of cases for which it will be particularly difficult to achieve desired dosimetric goals. Early detection of these cases will be of clinical value. Methods: This retrospective IRB‐approved study utilizes an existing database of treatment planning data for 121 lung SBRT patients. Patients who had multiple SBRT treatments or more than one lung tumor were excluded. In our department, SBRT patients receive treatment in either 3 fractions of 18Gy or 5 fractions of 10‐12Gy. Five fractions are generally used for cases in which planning goals are difficult to achieve in terms of target coverage vs. dose to OAR. Using the specific fractionation as a surrogate for plan difficulty, we examined possible correlations between fractionation and parameters including target size, total prescribed dose, number of fields and distance to OAR. Results: 84 patients received 3 fractions of treatment and 37 received 5 fractions. Patients with PTVs greater than 70 cm3 in size and ITVs greater than 40 cm3 were always treated with 5 fractions. These patients constituted approximately 20% of the 5 fraction patients. Tumors smaller than this size were sometimes (e.g. when situated close to an OAR) treated with 5 fractions. No correlation was observed between the fractionation and the number of fields. Conclusion: With large volume targets we can predict a treatment of 5 fractions. However, this represents a minority of patients. More powerful predictions could be possible by combining target size information with other metrics such as distance to nearby OARs. The ability to predict fractionation early in planning would allow for more efficient scheduling of LINAC time. Kaye Scholar Grant
Crosslinking of isocyanate functional acrylic latex with telechelic polybutadiene. II. Film formation/crosslinking

The mechanism of film formation and crosslinking in a poly(methyl methacrylate/n-butyl acrylate/TMI®) (PMBT) and amino-telechelic polybutadiene (PBD-NH 2 ) latex blend was studied. Films cast from the latex blends were ultramicrotomed and examined by transmission electron microscopy. The PBD-NH 2 was found to be located primarily at the surface of the PMBT particles due to a crosslinking reaction. Without the possibility of crosslinking ( when TMI was absent in the acrylic copolymer), the PBD-NH 2 only formed segregated phases in the acrylic polymer matrix due to the incompatibility of the two polymers. While this PBD-NH 2 could be extracted with toluene, the PBD-NH 2 crosslinked at the PMBT particle surfaces was not extractable. FTIR results showed that the isocyanate groups in the PMBT were completely consumed when the PBD-NH 2 concentration was sufficiently high, indicating that the PBD-NH 2 had diffused and reacted inside the PMBT particles. Thus, the crosslinking reaction was considered to be the driving force for the diffusion of the PBD-NH 2 into the PMBT particles.
Business Intelligence Analytics [Guest editors' introduction]

This special issue turns the spotlight on business intelligence (BI) as an area of inquiry and explores beyond the current standard practices. The articles in the issue describe the processes that practitioners currently follow in this area and how new BI techniques and capabilities will help users understand and act on widely disparate types of data. The articles also report on how organizations make decisions around datasets, what purposes visualizations are used for, and what different representations people use to show and explore data.
In vitro effects of serum proteins and lipids on lipid synthesis in human skin fibroblasts and leukocytes grown in culture.

Abstract Cultures of human skin fibroblasts incubated overnight in medium containing solvent-extracted serum showed a large increase in incorporation of labeled acetate into nonsaponifiable lipids. Freshly prepared monolayers of blood leukocytes were similarly stimulated following an incubation with solvent-extracted serum. No stimulation occurred with native serum. Incorporation of 3 H 2 O into nonsaponifiable lipids also increased substantially in both systems after the solvent-extracted serum treatment. The effect of solvent-extracted serum on nonsaponifiable lipids synthesis was paralleled in some cells by a stimulation of incorporation of acetate into fatty acids and of alanine into proteins. The stimulation of acetate incorporation into nonsaponifiable lipids was rapidly reversed in fibroblast cultures by whole serum, by low- and high-density lipoproteins, or by suspensions of cholesterol. These findings indicate that a feedback regulation of cholesterol synthesis may be operating in vitro both in cells grown in culture and in cells directly derived from the organism.
Intersection theorems for group divisible difference sets

Let D be an (m,n;k;@l"1,@l"2)-group divisible difference set (GDDS) of a group G, written additively, relative to H, i.e. D is a k-element subset of G, H is a normal subgroup of G of index m and order n and for every nonzero element g of G,@?{(d"1,d"2)@?,d"1,d"[email protected],d"1-d"2=g}@? is equal to @l"1 if g is in H, and equal to @l"2 if g is not in H. Let H"1,H"2,...,H"m be distinct cosets of H in G and S"[email protected]?H"i for all i=1,2,...,m. Some properties of S"1,S"2,...,S"m are studied here. Table 1 shows all possible cardinalities of S"i's when the order of G is not greater than 50 and not a prime. A matrix characterization of cyclic GDDS's with @l"1=0 implies that there exists a cyclic affine plane of even order, say n, only if n is divisible by 4 and there exists a cyclic (n-1,12n-1,14n-1)-difference set.
Two new silicate hydrates (C20H30N2)8 · [Si8O20]2 · 110H2O and (C20H30N2)4 · [Si8O20] · 42H2O, and their implications for the role of non-covalent interactions in high-silica zeolite synthesis

Abstract Two new silicate hydrates, (C20H30N2)8 · [Si8O20]2 · 110H2O (1) and (C20H30N2)4 · [Si8O20] · 42H2O (2) have been prepared and their structures determined using single-crystal X-ray diffraction. The structures of 1 and 2 are formed from silicate octameric cubes bridged by hydrogen-bonded water molecules. Crystal data for 1: P-1, Z=1, a=18.508(1) A, b=20.393(1) A, c=20.784(1) A, α=97.747(4)°, β=92.249(5)°, γ=116.396(3)°; 2: P-1, Z=1, a=14.345(1) A, b=14.855(1) A, c=16.162(1) A, α=80.339(5)°, β=84.916(5)°, γ=67.805(5)°. Both 1 and 2 have apertures formed by hydrogen-bonded water molecules which are approximately 9.5×5.5 and 12.0×9.0 A in 1 and 2, respectively. The structures of both hydrates have numerous weak C–H ⋯ O hydrogen bonds between the organic cations and water molecules. The importance of these and organic–inorganic electrostatic forces are discussed in the context of zeolite synthesis.
Fluorescence molecular-tomography reconstruction with a priori anatomical information

In this study, we combine a generalized Tikhonov regularization method with a priori anatomical information to reconstruct the concentration of fluorophores in mouse with Chronic Obstructive Pulmonary disease (COPD) from in vivo optical and Magnetic Resonance (MR) measurements. Generalized Tikhonov regularization incorporates a penalty term in the optimization formulation of the fluorescence molecular tomography (FMT) inverse problem. Our design involves two penalty terms to make use of a priori anatomical structural information from segmented MR images. The choice of the penalty terms guide the fluorophores in reconstructed image concentrates in the region where it is supposed to be and assure smooth flourophore distribution within tissue of same type and enhances the discontinuities between different tissue types. We compare our results with traditional Tikhanov regularization techniques in extensive simulations and demonstrate the performance our approach in vivo mouse data. The results show that the increased fluorophore concentration in the mouse lungs is consistent with an increased inflammatory response expected from the corresponding animal disease model.© (2008) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Cell-Specific Differences in DNase I Hypersensitivity between the Two Promoters of the Rat Glucokinase Gene

Abstract Glucokinase (GK) gene transcription occurs in the liver and the B cell of the endocrine pancreas where it is subject to different modes of regulation. This is accomplished largely through the use of two linked, cell-specific promoters separated by at least 12 kbp. We have used DNase I hypersensitivity to explore the chromatin structure surrounding the two promoters in cells that express either the liver or B cell form of the GK gene, as well as cells that do not express GK. In RIN38 cells, a β-cell-derived cell line, hypersensitive sites are detected over both the proximal and distal promoters. In liver, hypersensitive sites are present in the proximal promoter but not the distal promoter. Interestingly, in H4IIEC3 cells, a hepatoma cell line that has lost the ability to express GK, hypersensitive sites are also found in the proximal promoter but not the distal promoter.
Long-Term Associative Memory Capacity in Man

Long-term episodic memory depends on the retention of associative information, such as the relationship between a friend’s face and his name, a home and its neighborhood, and a mint and its odor. How many of these associative links can be stored and recalled? Many have considered memory’s capacity, but relevant data are scant. Some previous experiments on humans have assessed the retention of thousands of visual impressions using forced-choice picture recognition and have concluded that there are virtually no constraints on how much information can be successfully retained. However, no previous experiments on humans have investigated the capacity of associative memory. I describe the first relevant data, which I obtained by systematically probing my own capacity during 58,560 memory trials for picture-response associations (approximately 1 year of testing). Estimated capacity was on the order of several thousand associations, and this and other indicators of memory function were remarkably similar to those obtained for baboons (Papio papio) under comparable circumstances. These findings, along with other data, suggest conservation of long-term memory mechanisms and effectiveness in humans relative to nonhuman primates, despite at least 20 million years of divergent evolution and vastly different behavioral and cognitive repertoires. The present findings also indicate that the associative processes that support our ability to remember episodes are limited in capacity relative to processes that support picture recognition.
Local area network analysis using end-to-end delay tomography

There has been considerable interest over the last few years in collecting and analyzing internet traffic data in order to estimate quality of service parameters such as packet loss rates and delay distributions. In this paper, we focus on fast and efficient estimation methods for network link delay distributions based on end-to-end measurements obtained by probing the underlying. We introduce a rigorous statistical framework for designing the necessary probing experiments and examine the properties of the proposed estimators. The proposed framework and the resulting methodology are validated using data collected on the University of North Carolina (UNC) local area network.
Active/Passive, Acts/Passions: Greek and Roman Sexualities

GREEK AND ROMAN ANTIQUITY once impinged on the consciousness of modern historians for the models they provided of democracy and empire, political theory and military strategy. Today, if modern historians think about ancient Greece and Rome, they are quite likely to do so in the context of the history of sexuality. One reason for the relatively high visibility of the ancient world in this subdiscipline is the apparent Greek acceptance of (some) male same-sex relations, which makes such an apparent contrast with the contemporary situation. Since 1978, when Kenneth Dover broke the taboo on discussion of ancient same-sex relations in polite scholarly circles with Greek Homosexuality, scholarly works have followed one another fast and furiously.t The level of discourse in this discussion has been both extremely scholarly-whole theories often turning on the interpretation of certain words or individual passages in fairly arcane documents-and extremely vehement, revealing that these are issues about which scholars care even more than most historians usually care about their subjects.2 The reasons are not far to seek: scholars' approaches to issues of gender and sexuality often have real-world political antecedents or ramifications, which they see no reason to hide. Recent scholarship on ancient sexualities (or the lack of ancient sexualities, since some scholars deny the applicability of "sexuality" to the period) has reached consensus, if not complete agreement, on two main points: the social construction of sexuality (that "sexuality" is not a thing that can be found in all cultures but is created by the various discourses of particular societies), and the active/passive dichotomy (that the ancient world, both Greek and Roman, categorized sexual behaviors or identities not by the gender of the participants but by the sexual role each played). These ideas are still relatively novel, especially to nonspecialists, and
Tunable dye laser configurations

Abstract Various configurations for the successful operation of a continuous, tunable dye laser are described. Output powers as high as 100 milliwatts have been obtained using a 1.5 watt argon ion laser at 5145 A as the optical pump for the dye laser, with a tuning range of from 5640 A to 6150 A.
Development and psychometric testing of the Register - Connectedness Scale for Older Adults.

Connectedness, maintaining active engagement with life, is crucial to successful aging. Yet, no instruments were found to measure connectedness. The purpose of this study was to develop and test a connectedness scale for older adults. A 72-item instrument was administered to 428 community-dwelling older adults. The sample was largely female, White widows/widowers, with a mean age of 76 (SD 6.95) years. The instrument was reduced to 45 items representing five factors with loadings ranging from .40 to .86. The factor labels and their reliability estimates were: (a) self-regulating (.86), (b) facing aging (.85), (c) being part of a family (.87), (d) having friends (.87), and (e) being spiritual (.88). This promising instrument may advance the science of successful aging. © 2010 Wiley Periodicals, Inc. Res Nurs Health 34:60–72, 2011
A new microspectrophotometric method for measuring absorbance of rat photoreceptors

A method has been developed for obtaining visual pigment absorbance spectra from fixed, frozen sections of the albino rat retina. The retinas are transversely sectioned at various thicknesses on a cryo-microtome and the resulting slices are examined with a photon-counting microspectrophotometer. Problems caused by the limited pigment content of small receptors are reduced and measurements can be made at well-specified locations along the retinal section. This method is both precise and accurate and permits comparisons across sections and across animals.
Doubly differential measurements for multiple ionization of argon by electron impact: Comparison with positron impact and photoionization

Doubly differential cross sections for single and multiple ionization of Ar have been measured for 500, 750, and 1000 eV electron impact. The cross sections were measured as a function of projectile energy loss and scattering angle. The energy loss range was 0--85 % of the initial projectile energy and scattering angles were between $\ifmmode\pm\else\textpm\fi{}22\ifmmode^\circ\else\textdegree\fi{}.$ The data were put on an absolute scale by normalizing to total ionization cross sections available in the literature and found to be in good agreement with the absolute electron impact cross sections from DuBois and Rudd. For 750 eV impact, a comparison was made between the present electron impact data and positron impact data obtained using the same experimental conditions. The same energy dependence and yields for single ionization were found for both electron and positron impact. On the other hand, the double- and triple-ionization yields are smaller for positron impact as compared to electron impact. Comparisons with photoionization data showed that for outer shell ionization the fractions of double and triple ionization of argon by photon impact are in quite good agreement with the present electron impact data.
WOMEN, CRIME, AND DEPENDENCY An Application of the Theory of Law

This article seeks to show how economic dependency, a characteristic which is particularly representative of a woman's location in social life, is related to the outcome of criminal prosecution. A stratified random sample of 1034 cases of women offenders was drawn from the files of on Adult Probation Deportment in northern California. Based on multiple regression analysis, the findings give tentative support to the expectation that sentencing disparities within offense categories can be predicted from the degree to which a woman is economically dependent upon someone else for her day-to-day existence: the more dependent she is. the less severe her disposition.
Acetabular pressures during hip arthritis exercises.

Objective To examine in vivo maximum acetabular contact pressures during gait and hip arthritis exercises recommended by clinicians and the Arthritis Foundation. Methods Acetabular contact pressure data were collected for 2.5 years, at 3-4-month intervals, from an instrumented endoprosthesis implanted in an 84-year-old male who had sustained a left hip fracture. Maximum pressure data were compared for each activity. Results Mean pressures ranged from 9.0 +/- 2.3 megapascals (MPa) during maximum isometric hip abduction, 9.0 +/- 0.8 MPa during standing right hip abduction, and 8.9 +/- 2.8 MPa during standing left hip abduction to 1.2 +/- 0.3 MPa during quiet standing. Free-speed gait pressure averaged 5.6 +/- 0.9 MPa. The maximum mean pressure during side-lying hip abduction and straight leg raise at 30 degrees/second were less than the same activities at 60 degrees/second. Conclusions These in vivo hip pressure measurements challenge traditional protocols for patients with hip osteoarthritis and provide quantitative data as a framework for designing exercise programs. Maximum isometric hip exercise and standing exercise generated much higher hip pressures, and are therefore probably more stressful to acetabular cartilage, than gait or stationary cycling. Clinicians must consider exercise velocity because of its direct correlation with hip contact pressure. Walking generated lower pressure than most activities studied and, given its other benefits, is therefore probably beneficial for patients with hip osteoarthritis.
Optimization of Fan Flow Deflection for Supersonic Turbofan Engines

*† This study involves the application of fan flow deflectors for suppression of jet noise from low-bypass turbofan engines for next-generation supersonic aircraft. Experiments using canonical vane deflectors seek to establish correlations between aerodynamics, distortion of the mean velocity field in the jet plume, and noise reduction. The maximum radial velocity gradient, as a function of axial distance and azimuth angle, is used to quantify distortions of the plume. Vanes mounted at low azimuth angles (with respect to the downward vertical) reduce gradients in the downward direction, while vanes mounted at high azimuth angles reduce gradients in the sideline reduction. There is a significant correlation between gradient reduction and noise suppression in the azimuthal direction of the gradient. In addition, it is found that vanes with cambered airfoils perform better than vanes with symmetric airfoils. The trends obtained were used in the successful design of deflector configurations consisting of two pairs of vanes which resulted in cumulative peak overall sound pressure level (OASPL) and effective perceived noise level (EPNL) reductions of 8.8 dB and 6.7 dB respectively.
An optimal time-invariant approximation for wind turbine dynamics using the multi-blade coordinate transformation

Wind turbines are subject to periodic loads that result in a time-varying “trim” condition. Linearizing the nonlinear turbine dynamics around this trim condition yields a periodic, linear time-varying (PLTV) system. A linear time-invariant (LTI) approximation is typically obtained in two steps. First, the multi-blade coordinate transformation is applied to the PLTV system to obtain a weakly periodic system. Second, the state matrices of the weakly periodic system are averaged over one period to obtain an LTI approximation. This paper presents an alternative approach to construct optimal LTI approximations using convex optimization. It is also shown that the multi-blade coordinate transformation followed by averaging is equivalent to a special case of the proposed convex optimization procedure. The proposed approach is demonstrated on a linearized model of a utility-scale turbine.
Early time course of myocardial electrical impedance during acute coronary artery occlusion in pigs, dogs, and humans

Changes in myocardial electrical impedance (MEI) and physiological end points have been correlated during acute ischemia. However, the importance of MEI's early time course is not clear. This study evaluates such significance, by comparing the temporal behavior of MEI during acute total occlusion of the left anterior descending coronary artery in anesthetized humans, dogs, and pigs. Here, interspecies differences in three MEI parameters (baseline, time to plateau onset, and plateau value normalized by baseline) were evaluated using Kruskal-Wallis ANOVA and post hoc tests (P < 0.05). Noteworthy differences in the MEI time to plateau onset were observed: In dogs, MEI ischemic plateau was reached after 46.3 min (SD 12.9) min of occlusion, a significantly longer period compared with that of pigs and humans [4.7 (SD 1.2) and 4.1 min (SD 1.9), respectively]. However, no differences could be observed between both animal species regarding the normalized MEI ischemic plateau value (15.3% (SD 4.7) in pigs, vs. 19.6% (SD 2.6) in dogs). For all studied MEI parameters, only swine values resembled those of humans. The severity of myocardial supply ischemia, resulting from coronary artery occlusion, is known to be dependent on collateral flow. Thus, because dogs possess a well-developed collateral system (unlike humans or pigs), they have shown superior resistance to occlusion of a coronary artery. Here, the early MEI time course after left anterior descending coronary artery occlusion, represented by the time required to reach ischemic plateau, was proven to reflect such interspecies differences.
The effect of column purification on cDNA indirect labelling for microarrays

Background: The success of the microarray reproducibility is dependent upon the performance of standardized procedures. Since the introduction of microarray technology for the analysis of global gene expression, reproducibility of results among different laboratories has been a major problem. Two of the main contributors to this variability are the use of different microarray platforms and different laboratory practices. In this paper, we address the latter question in terms of how variation in one of the steps of a labelling procedure affects the cDNA product prior to microarray hybridization. Results: We used a standard procedure to label cDNA for microarray hybridization and employed different types of column chromatography for cDNA purification. After purifying labelled cDNA, we used the Agilent 2100 Bioanalyzer and agarose gel electrophoresis to assess the quality of the labelled cDNA before its hybridization onto a microarray platform. There were major differences in the cDNA profile (i.e. cDNA fragment lengths and abundance) as a result of using four different columns for purification. In addition, different columns have different efficiencies to remove rRNA contamination. This study indicates that the appropriate column to use in this type of protocol has to be experimentally determined. Finally, we present new evidence establishing the importance of testing the method of purification used during an indirect labelling procedure. Our results confirm the importance of assessing the quality of the sample in the labelling procedure prior to hybridization onto a microarray platform. Conclusion: Standardization of column purification systems to be used in labelling procedures will improve the reproducibility of microarray results among different laboratories. In addition, implementation of a quality control check point of the labelled samples prior to microarray hybridization will prevent hybridizing a poor quality sample to expensive micorarrays.
MAGMA IN A BEAKER: ANALOG EXPERIMENTS WITH WATER AND VARIOUS SALTS OR SUGAR FOR TEACHING IGNEOUS PETROLOGY

Solutions of water and a salt or sugar make excellent experimental analog magmas for teaching concepts of igneous petrology because of the comparatively low temperatures involved, the simplicity of the apparatus needed, and the responsiveness of familiar chemical systems. Boiling of these aqueous solutions on a hot plate can be used to increase the concentration of a dissolved salt or sugar to levels that may be predicted by steam-saturation curves. Sufficiently concentrated solutions will crystallize, partially or completely, upon cooling to room temperature. Binary temperature–composition phase diagrams for H 2 O and KCl, NaCl, MgCl 2 , CaCl 2 , or C 12 H 22 O 11 have been drawn to provide guidance for experiments, and equations are given for the saturation curves. Possible instructional activities with these simple systems include: (1) determination of saturation (liquidus) curves on binary phase diagrams, (2) measurement of the relative proportions of liquid and solid in a system that has partially crystallized, and comparison with predictions of the lever rule, (3) observation of some consequences of peritectic reactions on crystallization, (4) observation of the kinetic effects of temperature and concentration on crystallization, (5) simulation of a magma chamber with crystals settling because of their density and rising owing to convection, and (6) observation of simultaneous boiling and crystallization that buffer temperature, which can lead to a solid with vapor cavities. Movies of interesting aspects of these experiments are available online as supplementary documents.
Propensity-matched analysis of the effect of preoperative intraaortic balloon pump in coronary artery bypass grafting after recent acute myocardial infarction on postoperative outcomes

There is substantial variability in the preoperative use of intraaortic balloon pumps (IABPs) in patients undergoing coronary artery bypass grafting post myocardial infarction. The objective of this study is to determine the effect of preoperative IABPs on postsurgical outcomes in this subset of patients. From 2007 to 2012, 877 patients underwent isolated coronary artery bypass post myocardial infarction. Four hundred and six patients were propensity-score matched based on the likelihood of receiving a preoperative balloon pump. Total blood transfusion requirements, composite in-hospital morbidity and/or mortality end point, total hours in the intensive care unit, and length of hospital stay were compared between the two groups. No significant differences in demographics, preoperative risk factors, intraoperative variables or length of hospital stay were found between patients with and without balloon pumps after propensity score matching. Compared to patients without balloon pumps, a higher percentage of patients with preoperative IABPs required transfusions. Patients with preoperative balloon pumps were more likely to have the composite end point of in-hospital morbidity (24.1% versus 12.8%, P <0.004), and increased hours in the intensive care unit (median hours: 69.0 versus 46.0, P <0.013) as compared to patients without balloon pumps. The use of preoperative IABPs in patients undergoing isolated coronary artery bypass grafting after myocardial infarction is associated with increased transfusion requirements, increased in-hospital morbidity and longer postoperative intensive care unit stay as compared to patients without IABPs.
Transvaginal ultrasound: does it help in the diagnosis of placenta previa?

The purpose of this study is to evaluate the use of transvaginal ultrasound in the diagnosis of placenta previa and to assess the risk of bleeding secondary to the placement of the vaginal transducer. Thirty-eight patients with an estimated gestational age equal to or greater than 26 weeks and the diagnosis of suspected placenta previa gave their consent and were randomized to two groups. Randomization was stratified by patient weight and anterior or posterior placental location. Group 1 (n = 20) had complete obstetric ultrasounds using linear and sector transducers. Group 2 (n = 18) had similar examinations followed by transvaginal ultrasound scans. Patients were rescanned to follow placental location and fetal growth parameters. On abdominal ultrasound, the posterior placenta (n = 17) was often shadowed by fetal parts. The ease of placental visualization was rated on a four-point scale with 1 being the clearest. The mean clarity score for posterior placentas on abdominal ultrasound in Group 2 was 1.6 and on transvaginal ultrasound was 1.0, p < 0.04. The use of transvaginal ultrasound consistently revealed greater clarity of diagnosis in these patients. No patient in either group experienced increased vaginal bleeding following the scanning sessions. Transvaginal ultrasound was most beneficial for those patients with posterior placenta previas because of increased clarity of diagnosis, decreased time of scanning, and no increased incidence of hemorrhage.
Attenuation characteristics of high rate home-networking PLC signals

This paper reports an experimental investigation of the influence of the high-frequency (HF) signal attenuation on the load in residences and offices. A laboratory test and actual measurements were performed in a residence and an office. The experiments show that the attenuation characteristics are more dependent on the number of loads than the type of loads connected. In addition, the concentration of loads was found to determine where the maximum attenuation of the HF signals would occur. The types and the size of the loads, however, did not affect the attenuation characteristics of the HF signals. Therefore, for a successful high-rate power line carrier (PLC) home networking, the analysis on the placement of the loads may have to be considered for better understanding of signal attenuation for PLC modems and other PLC-to-media adapters.
Cutting-edge Science and Coffee: Auditory System Gordon Research Conference and Seminar 2012 Report

At the third Gordon Research Conference and Gordon Research Seminar on the Auditory System (2012), investigators from all career stages reported on emerging research in a broad range of sub-fields. A distinguishing feature of these conferences is their attention to junior investigators, and their experience is the focus of this conference report.
Prospective evaluation of pain medication requirements and recovery after radical perineal prostatectomy

Abstract Objectives To perform a study to quantify the variables relating to postoperative pain, activity, and gastrointestinal function after radical perineal prostatectomy to allow comparisons with alternative treatments. Methods Ninety-eight consecutive radical perineal prostatectomy candidates between January 2001 and December 2001 with clinically localized prostate cancer were prospectively evaluated. The time to tolerate solid food, time to unassisted ambulation, postoperative pain levels (analog pain scale of 1 to 10), and perioperative analgesic requirements (in morphine equivalents) were selected as the analysis endpoints and correlated with preoperative (age, American Society of Anesthesiology class, body mass index, and serum prostate-specific antigen level), intraoperative (node dissection, operating room time, and estimated blood loss), and postoperative (Gleason score, tumor stage, and lower extremity neurapraxia) patient variables. Results The mean time to tolerate solid food and unassisted ambulation was 21.2 ± 1.4 and 22.4 ± 0.8 hours, respectively; 25.5% of patients experienced transient lower extremity neurapraxia, which was associated with longer operative times ( P = 0.001). In a multivariate regression analysis, lymph node dissection correlated with both a prolonged time to tolerate solid food ( P = 0.002) and unassisted ambulation ( P = 0.001) and neurapraxia with an extended time to unassisted ambulation ( P = 0.018). The narcotic requirements were greatest on postoperative day 1, totaling 31.7 ± 3.0 morphine equivalents, of which 90.5% ± 3.1% were met with oral analgesics. The average maximal pain scores were highest the first week after discharge (4.7 ± 0.3), yet approached baseline levels by 4 weeks (1.7 ± 0.2) after surgery at which time no patient required any pain medication. Conclusions Modern radical perineal prostatectomy offers a favorable outcome profile with early patient recovery and low narcotic requirements. A future prospective study should directly compare radical perineal, retropubic, and laparoscopic prostatectomy to document whether the latter offers any advantages with respect to these outcome parameters.
Properties of Trypsin from the Pyloric Ceca of Atlantic Cod (Gadus morhua)

Trypsin (EC 3.4.21.4) was isolated from the pyloric ceca of Atlantic cod and purified to homogeneity by affinity chromatography. The enzyme catalyzed the hydrolysis of benzoyl arginine p-nitroanilide (BAPA, pH 8.2 and 25°C) such that Vmax was 250 BAPA units per micromole trypsin and Km was 1.48 mM. For the hydrolysis of tosyl arginine methyl ester (TAME, pH 8.1 and 25°C), Vmax was 18.2 × 103 TAME units/micromole trypsin, and Km 0.22 mM. The pH and temperature optima with BAPA substrate were 7.5 and 40°C, respectively. Atlantic cod trypsin was most active and stable at alkaline pH. The enzyme was heat labile, losing more than 50% of its activity after incubation at 50°C for 30 min. Amino acid analysis of Atlantic cod trypsin revealed that the enzyme was rich in residues such as serine, glycine, glutamate and aspartate, but poor in basic amino acid residues compared to trypsins from warm blooded animals.
GAS CHROMATOGRAPHY OF SOME ANTIHISTAMINES.

The gas chromatographic behavior of 16 antihistamines was investigated using packed 0.010-in. diameter capillary and 0.065-in. open tubular columns. All packed columns were 6 ft. long, with a low phase to support ratio and were operated at 175°. The liquid phases used were Carbowax 20M, SE-30, XF-1150, and PDEAS. Of the seven solid supports evaluated for use in low loaded columns, only glass beads, Gas Chrom-P, and Chromosorb W-HMDS proved to be satisfactory. The most successful column for the separation of these antihistamines was a 6-ft.–0.08% PDEAS on 120/170 glass-bead column operated at a temperature of 175°. This column provided good separation and symmetrical peaks. Instrument limitations prevented any valid evaluation of the 0.010-in. capillary column and of the 0.065-in. open tubular column for antihistamine separation.
Induction-heated tool machining of elastomers - Part 2: Chip morphology, cutting forces, and machined surfaces

ABSTRACT The induction-heated tool and cryogenically cooled workpiece are investigated for end milling of elastomers to generate desirable shape and surface roughness. Elastomer end milling experiments are conducted to study effects of the cutting speed, tool heating, and workpiece cooling on the chip formation, cutting forces, groove width, and surface roughness. At high cutting speed, smoke is generated and becomes an environmental hazard. At low cutting speeds, induction heated tool, if properly utilized, has demonstrated to be beneficial for the precision machining of elastomer with better surface roughness and dimensional control. Frequency analysis of cutting forces shows that the soft elastomer workpiece has low frequency vibration, which can be correlated to the surface machining marks. The width of end-milled grooves is only 68 to 78% of the tool diameter. The correlation between the machined groove width and cutting force reveals the importance of the workpiece compliance to precision machining ...