cssi/SciSciGPT-SciSciNet huggingface dataset:
Interaction of a Plane Shock and Oblique Plane Disturbances With Special Reference to Entropy Waves

The problem of the interaction between a plane entropy wave of arbitrary orientation and a plane oblique shock of infinite extent is investigated. As a result of the interaction, it is found that, in the perturbed flow field downstream of the shock, three kinds of disturbances are present—namety, an entropy mode, a vorticity mode, and a sound mode. The nature of the sound wave generated depends on the orientation of the upstream disturbance. Within certain orientations of the upstream disturbance, the sound waves generated downstream attenuate. Beyond these orientations, the sound waves generated have constant amplitudes. When the downstream sound waves are not attenuated, there is no phase shift in the entropy disturbance across the shock; when the downstream sound waves are attenuated, a phase shift occurs in the entropy disturbance across the shock. An illustrative example is given for the interaction between a plane normal shock and a sinusoidal entropy wave. At a given shock strength the amplitudes of the shock displacement and the downstream disturbances generated are plotted as functions of the orientation of the upstream disturbance.
Biochemistry of dimorphism in the fungus Mucor.

Publisher Summary The chapter summarizes the recent biochemical studies on various aspects of development in Mucor. The asexual life cycle of Mucor can be divided into three stages: sporangiospore germination, vegetative growth, and sporangiospore formation. Hyphal growth in Mucor racemosus, as in the other filamentous fungi, is characterized by apical growth of the cell wall. Yeast growth in M. racemosus is characterized by spherical multipolar budding cells with cell–wall synthesis uniformly distributed over the cell surface. Several environmental factors influence dimorphism in Mucor. In general, each factor acts equally well on sporangiospores or vegetative cells. The chapter explores that cellular morphogenesis involves the interaction of many types of molecules and probably the activation of new genetic information. One approach to the study of dimorphism in fungi has been to examine the focus of that morphogenetic change—namely, the cell wall. Another approach, which seems more likely to reveal the fundamental mechanisms of “genetic” expression is to study synthesis of macromolecules. The study of morphogenesis in Mucor species has the advantage that genetic studies are possible. Many species of Mucor are heterothallic and—when mated under suitable conditions—produce sexual spores, called “zygospores.”
New polyisobutylene stars. XI. Synthesis and characterization of allyl-telechelic octa-arm polyisobutylene stars

The synthesis and characterization of a novel star comprising eight allyl-terminated polyisobutylene (PIB) arms radiating from a calix[8]arene core is described. The synthesis was accomplished by a core-first method, by inducing the living polymerization of isobutylene (IB) by a suitably functionalized calix[8]arene initiator (1) in conjunction with BCl3-TiCl4 coinitiators, and terminating the growth of the living PIB⊕ arms by allyltrimethylsilane. The relative concentrations of BCl3 and TiCl4 are critical for the synthesis of well-defined 8-arm stars. Characterization of the products (which included triple detector GPC studies and 1H NMR spectroscopy) indicated quantitative allylation. A mechanism which summarizes the experimental observations is proposed.
The “weekend effect” in urgent general operative procedures

Background There is growing concern that the quality of inpatient care may differ on weekends versus weekdays. We assessed the “weekend effect” in common urgent general operative procedures. Methods The Healthcare Cost and Utilization Project Florida State Inpatient Database (2007−2010) was queried to identify inpatient stays with urgent or emergent admissions and surgery on the same day. Included were patients undergoing appendectomy, cholecystectomy for acute cholecystitis, and hernia repair for obstructed/gangrenous hernia. Outcomes included duration of stay, inpatient mortality, hospital-adjusted charges, and postoperative complications. Controlling for hospital and patient characteristics and type of surgery, we used multilevel mixed-effects regression modeling to examine associations between patient outcomes and admissions day (weekend vs weekday). Results A total of 80,861 same-day surgeries were identified, of which 19,078 (23.6%) occurred during the weekend. Patients operated on during the weekend had greater charges by $185 ( P P P P = .01), wound complications (OR 1.32, 95% CI 1.04–1.68; P P P P = .001) and greater charges ( P = .003). Conclusion Patients undergoing weekend surgery for common, urgent general operations are at risk for increased postoperative complications, duration of stay, and hospital charges. Because the cause of the “weekend effect” is still unknown, future studies should focus on elucidating the characteristics that may overcome this disparity.
Depletion of complement does not impact initiation of xenobiotic-induced autoimmune disease.

Summary Deficiency in Daf1, a complement regulatory protein, has been shown to exacerbate development of various autoimmune diseases and recent studies have suggested that this may be explained by Daf1 acting to limit T-cell hyper-responsiveness. It has been suggested that the absence of Daf1 aggravates autoimmune disease in a complement-dependent manner, but others have shown that activation of T cells in the absence of Daf1 can be complement independent. However, the relationship between Daf1, complement components, lymphocyte activation, cytokine expression and antibody production remains to be determined in mice that are not Daf1 deficient. We have recently demonstrated, in murine mercuryinduced autoimmunity (mHgIA), that an accumulation of CD44 high Daf low CD4 + T cells is associated with the development of autoimmunity. In this study we observed that complement depletion does not affect the accumulation of activated CD4 + T cells, elevation of splenic interleukin-4 expression and autoantibody production in mHgIA. In addition, neither the accumulation of CD44 high Daf low CD4 + T cells nor the down-regulation of Daf1 expression on CD4 + T cells was influenced by a lack of
When a House Is More Than a Home: Performance of the Household Portfolio

Home equity investment comprises a substantial portion of the household portfolio, consequently, it can be an important source of wealth accumulation. Several studies have suggested that the United...
A GM2-specific beta-hexosaminidase from the roe of striped mullet (Mugil cephalus).

Abstract The roe of striped mullet (Mugil cephalus) was found to contain a beta-hexosaminidase different from the beta-hexosaminidases isolated from other sources. The enzyme from mullet roe is able to cleave GalNAc from GM2 without the assistance of either an activator protein or a detergent. It also cleaves the oligosaccharide derived from GM2 and other oligosaccharides containing the GM2 sequence GalNAc beta 4(NeuAc alpha 3)Gal-. However, it is not effective in hydrolyzing neutral glycosphingolipids containing terminal GalNAc or GlcNAc, such as GbOse4Cer, GgOse3Cer, or LcOse3Cer. These results indicate that mullet roe beta-hexosaminidase can specifically cleave GalNAc from the glycoconjugates containing the GM2 sequence. No beta-hexosaminidase with such specificity has been previously described. Thus, this unique enzyme should be very useful for the detection and analysis of glycoconjugates containing the oligosaccharide chains with GM2 sequence.
Teaching Science to Academically Underprepared Students

A major problem facing science education in the United States today is its failure to produce enough well-educated minority students in the natural sciences and engineering. In most cases, the early difficulties encountered by these students in middle schools persists for years and prevent majority of them from pursuing advanced degrees and careers in the sciences and engineering. Thus, the need for new teaching approaches that will motivate and channel these students, who represent the fastest growing segment of our society into science and engineering. A number of factors contribute to this underrepresentation, amongst which are perception, exclusion, and instructional strategies. Here, we report on some important factors and teaching strategies, which, when proper considered, would influence the success of minority students in the sciences. Transitional strategies are techniques that facilitators may use to help underprepared students to learn to bridge or relate different parts or situations to one common idea, fact, or skill. It is hoped that when this strategy is infused with content, along with study skills, learning styles, and sequence as well as students' personal inventories, minority performance in science and mathematics will improve.
Underestimation of left atrial volume by three-dimensional echocardiography validated by magnetic resonance imaging: a meta-analysis and investigation of the source of bias.

Background: Left atrial volume (LAV) is a fundamental prognostic factor in a variety of cardiac diseases including atrial fibrillation, heart failure, and valvular diseases. Developing a repeatable, noninvasive, and accurate method of measuring LAV is crucial. Three-dimensional echocardiography (3DE) has achieved better estimation of LAV than two-dimensional echocardiography. However, underestimation of LAV by 3DE has often been reported and no previous study has synthesized these data. The present study aimed at revealing existence and extent of bias in LAV measurement by 3DE and investigating related factors affecting the bias. Methods: Studies comparing LAV between 3DE and magnetic resonance imaging published before August 15, 2011 were eligible. A meta-analysis with random effects model was performed to evaluate the systematic bias. Factors affecting the bias were investigated by univariate followed by multivariate analysis. Results: A total of 14 studies including 395 subjects revealed underestimation of LAV by 3DE (−9.4 mL; 95% confidence interval, −13.2 to −5.6mL; P < 0.00001, Fig. 2). Existence of cardiac disease led to more underestimation, whereas increasing the number of plane included in the analysis counteracted the underestimation (P < 0.00001 for each comparison). Conclusions: Only by synthesizing a number of small studies as a meta-analysis could we display underestimation of LAV by 3DE and factors influencing the systematic bias. These data provide a more detailed basis for analyzing and improving the accuracy of 3DE, an indispensable step toward further clinical application in LAV assessment. (Echocardiography 2012;29:385-390) Figure 2. Meta-analysis of difference in left atrial volume between 3D-echocardiography and magnetic resonance imaging. Note the significant underestimation of left atrial volume by 3D-echocardiography. 3DE = three-dimensional echocardiography; CI = confidence interval; Max = maximal volume; Min = minimal volume; MRI = magnetic resonance imaging; Nl = normal subjects; pl = planes; Pt = patients. Download figure to PowerPoint
Structures and a Two-Band Model for the System V 1-x Cr x O 2

The evolution with $x$ of the monoclinic-to-tetragonal transition temperature and of the room-temperature monoclinic structures of the system ${\mathrm{V}}_{1\ensuremath{-}x}{\mathrm{Cr}}_{x}{\mathrm{O}}_{2}$ have been reexamined and extended to cover the entire solid-solution range $0\ensuremath{\le}xl0.20$. The space group of the room-temperature monoclinic phase changes from $\frac{P{2}_{1}}{c}$ at $x=0$ to $\frac{C2}{m}$ for $0.005\ensuremath{\le}x\ensuremath{\le}0.065$ and $\frac{P2}{m}$ for $0.07\ensuremath{\le}xl0.20$. The monoclinic $\frac{P2}{m}$ structure is determined for the first time. The distortion from tetragonal symmetry is accomplished by a contraction of the V-O bonds in the tetragonal ${(110)}_{r}$ planes and an expansion in the ${(1\overline{1}0)}_{r}$ planes. The structures and the conductivity changes are interpreted in terms of two overlapping bands that change their relative stabilities with $x$. The substitutional ${\mathrm{Cr}}^{3+}$ ions, which have a localized-electron ${d}^{3}$ configuration, also perturb the electron potential sufficiently to induce, at larger $x$, a $3d$-electron localization on the vanadium ions.
Object Displays Do Not Always Support Better Integrated Task Performance

This study examines Wickens' compatibility of proximity hypothesis of visual display design and proposes that an emergent-features approach might carry more explanatory power. Two studies show that a bar graph display is superior to an object display in an integration task if the bar graph has a strong emergent feature that maps directly onto a goal-relevant task invariant. Earlier results by Wickens and colleagues showing an object display advantage could not be replicated or generalized. These new findings suggest that object display advantages occur only under limited conditions and that the exploitation of emergent features may more predictably lead to an advantage of one display over another.
Solubility of K in Fe-S liquid, silicate-K-(Fe-S) liq equilibria, and their planetary implications

Potassium has been found to have extremely limited absolute solubility in Fe-S liquid in the pressure-temperature range of 18 to 40 kbars, 1050 to 1150 C, and fO2 within the field of metallic iron. It also partitioned into a certain silicate phase highly in preference to Fe-S liquid at 30 kbar and 1100 C. The dependence of the partitioning of K between solid silicate and Fe-S liquid on fO2 and compositions of mineral solid solutions have been analyzed. These experimental data, along with those of others, limit the amount of K that could fractionate in Fe-S liquid layers or a core in the early history of the moon and, thus, act as localized heat sources in its thermal history models; the data also seem to argue against a chondritic abundance of potassium for earth. The question of fractionation of enough K-40 in an Fe-S liquid outer core of earth to provide the necesary thermal energy for the geomagnetic dynamo remains unresolved.
Comparison of spatial and temporal characteristics between microplasma jet arrays and a single macroplasma jet

When low temperature plasma is generated in a flowing gas system, interactions with a material surface provide a versatile candidate for biochemical processing. By controlling the surrounding medium or tailoring the input gas, specific radicals and excited species can be produced within the plasma, which greatly benefit its applications in medical therapeutics and materials processing. The propagation of plasma jets into atmospheric pressure air is accompanied by spatially and temporally-resolved emission profiles that have been compared between microplasma jet arrays and a single macroplasma jet having the same cross-sectional area. The plasma-background gas interaction surface area, over which where plasma chemistry reactions occur has been significantly increased with a microplasma array. Multiple ionization bullets, with velocities of 0.3 –0.5 km/s, have been produced from a microchannel with a diameter of 355 µm. An order of magnitude increase in the velocity of the plasma jets has been observed by inserting a ground electrode and a dielectric barrier downstream to the jet aperture. The shape and velocity of propagation can be strongly influenced by the design of the jet aperture and the external ground. Spatial emission profiles confirm the advantage of large area treatment of tissue or a material surface with the microplasma array. The details will be discussed.
Caught in the act: α-synuclein is the culprit in Parkinson's disease

Abstract Previous reports on Parkinson's disease indicate that genetic mutations in α-synuclein result in the aberrant accumulation of this protein, causing toxic gain of function leading to the development of Parkinson's. A recent report on the Iowan kindred, an extended pedigree with an autosomal dominant form of this disease, provides new mechanistic insight into Parkinson's disease by showing that an elevation in wild-type α-synuclein protein is sufficient to develop the early-onset form of the disorder. This review discusses how insights gained from these studies of α-synuclein may direct future research into Parkinson's disease.
Oxidative detoxification of sulfide by mitochondria of the California killifish Fundulus parvipinnis and the speckled sanddab Citharichthys sitgmaeus

Earlier whole-animal experiments have shown that the California killifish (Fundulus parvipinnis) from tidal marshes is highly tolerant to sulfide while the speckled sanddab (Citharichtys stigmaeus) from the open coast is intolerant to sulfide. In the present paper, we demonstrate that the liver mitochondria of the California killifish detoxify sulfide by oxidizing it to thiosulfate and produce ATP in the process. Sulfide oxidation is obligately and stoichiometrically linked to mitochondrial electron transport to oxygen. Concentrations up to 20 μM sulfide stimulate mitochondrial respiration while 50 μM sulfide causes half-inhibition. Sulfide oxidation by mitochondria is adversely affected at pH<7.4. ATP production is maximal at 10 μM sulfide. The finding of sulfide oxidation coupled to ATP production by killifish mitochondria is unprecedented among vertebrates. In comparison, mitochondria of the specked sanddab oxidize sulfide at a much lower rate. This is the first demonstration of biochemical adaptation to sulfide among coastal marine fishes.
Levomepromazine as a treatment for non-epileptic movement disorder in advanced neurodegenerative lysosomal disorders

In this study, we tried to determine the crystal structure of human α-l-iduronidase (hIDUA) and elucidate the structural basis of mucopolysaccharidosis type I (MPS I). We crystallized and solved the structure of hIDUA by the single isomorphous replacement with anomalous scattering method. A deglycosylation study was performed to examine the involvement of N-glycan in the substrate interaction. Then, we built structural models of mutant hIDUA due to 57 amino acid substitutions that had been identified in 27 severe, 1 severeintermediate, 13 intermediate, 1 attenuated-intermediate and 15 attenuated type MPS I patients by means of homology modeling using the crystal hIDUA structure as a template. The structural changes were examined by calculating the root-mean-square distances (RMSDs) and the number of atoms influenced by the amino acid replacements. We solved the crystal structures of apoand iduronic acid -bound hIDUA consisting of three domains: a triosephosphate isomerase barrel fold, a β-sandwich domain and an immunoglobulin-like domain. The mannose residue of the N-glycan attached to N372 constituted a part of the substrate-binding pocket and interacted directly with a substrate. The result of deglycosylation study showed that the hIDUA enzyme activity was highly correlated with the N-glycan attached to N372. Structural analysis revealed that W306 interacts with the N-glycan at N372 and the W306L mutation may cause MPS I through the effect on the conformation of theN-glycan atN372. Further structural study revealed that the RMSD values and the numbers of atoms influenced by amino acid substitutions found in severeMPS I patients were larger than those in intermediate and attenuated MPS I ones, suggesting that the structural changes of hIDUA tended to be correlated with the severity of the disease. Coloring of atoms influenced by an amino acid substitution was performed in each case. On the basis of these results, we constructed a database and disclosed the structural information involving MPS I. Structural investigation is useful for elucidating the basis of MPS I.
Dental Therapists Evidence of Technical Competence

Dental therapists are members of the dental team in many countries, where they perform a limited number of irreversible restorative procedures. In the United States, they practice only in Alaska and Minnesota, though other states are considering adding them in an effort to improve access to care. While critics of this workforce model cite concern for patient safety, proponents argue that dental therapists provide treatment that is as technically competent as that provided by dentists. Though nearly 2 dozen studies from industrialized countries address this subject, this article systematically reviews all 23 of them. Of these reports, all but 2 conclude that dental therapists perform at an acceptable level. Every study that directly compared the work of dental therapists with that of dentists found that they performed at least as well. Regardless of whether dental therapists would be the most effective intervention for improving access to oral health care in the United States, the evidence clearly suggests...
The molecular biology of polycystic kidney disease.

In recent years there have been a number of developments in polycystic kidney disease (PKD) research. The genes associated with the predominant forms of autosomal dominant PKD have been cloned, and the gene associated with a mouse model for autosomal recessive PKD has been identified and characterized. Other studies have yielded new information regarding the role of the epidermal growth factor receptor gene in promoting renal cyst formation. In this review article we summarize recent pulished data on the molecular genetics of autosomal dominant and autosomal recessive PKD and provide a working model of how multiple genes participate in the PKD disease pathway.
Growth and Characterization of Highly Oxygen-Doped GaAs

High levels (≃ 1018cm-3) of oxygen were introduced into GaAs by using dimethyl aluminum methoxide (DMAlM0) as an oxygen-bearing precursor during metalorganic vapor phase epitaxy. Layers co-doped with oxygen and intentionally added silicon, both to concentrations of ≃ 1018 cm-3, were depleted of free carriers and had no measurable luminescence. Deep levels were present in layers grown with lower oxygen incorporation, but the compensation mechanism due to oxygen incorporation is not apparently tied to a specific defect level. The material with the electronic deep levels also possessed deep luminescence energy lines. All layers exhibited excellent surface morphology. For comparison, other layers were grown by introducing low levels of 02 and trimethyl aluminum during GaAs growth. The surface morphology of these layers was usually hazy and the layers did not exhibit the same well defined electrical and optical characteristics as the layers grown with DMAlMO.
Disorientation of Suprathermally Rotating Grains and the Grain Alignment Problem

We discuss the dynamics of dust grains subjected to torques arising from H2 formation. In particular, we discuss grain dynamics when a grain spins down and goes through a "crossover" event. As first pointed out by Spitzer & McGlynn, the grain angular momentum before and after a crossover event are correlated, and the degree of this correlation critically affects the alignment of dust grains by paramagnetic dissipation. We calculate the correlation including the important effects of thermal fluctuations within the grain material. These fluctuations limit the degree to which the grain angular momentum J is coupled with the grain principal axis a1 of maximal inertia. We show that this imperfect coupling of a1 with J plays a critical role during crossovers and can substantially increase the efficiency of paramagnetic alignment for grains larger than 0.1 μm. As a result, we show that for reasonable choices of parameters, the observed alignment of a 0.1 μm grains could be achieved by paramagnetic dissipation in suprathermally rotating grains, if radiative torques caused by starlight were not present. We also show that the efficiency of mechanical alignment in the limit of long alignment times is not altered by the thermal fluctuations in the grain material.
NQR-NMR spin-1 zero-splitting ellipse☆

Abstract The nuclear spin Hamiltonian for an I = 1 nucleus is solved exactly in the case where the Zeeman and quadrupole interactions are of comparable magnitude. A geometrical method is described for obtaining the asymmetry parameter η and the EFG principal axes' directions by means of a “zero-splitting ellipse” when the condition |e 2 qQ| h H 0 can be met. The results lead to a simplified experimental procedure for obtaining the nuclear quadrupole coupling parameters in 14 N and 2 H.
Forward AGC design considerations in transistorized television receivers

Similar considerations govern the age circuit design of both tube and transistor television receivers.
Gordon McLendon: The Maverick of Radio

Introduction Childhood, Education and Military Career KNET and KLIF: First Ventures into Radio The Liberty Broadcasting System: Halcyon Days The Liberty Broadcasting System: Finis KLIF and Top 40 Radio McLendon Station Group: Acquisition and Management McLendon Station Format Innovations McLendon Station Editorials Departure from Radio Politics, Moviemaking and Other Interests Reflections Reference List Bibliography Index
Ischemic preconditioning or heat shock pretreatment ameliorates neuronal apoptosis following hypothermic circulatory arrest.

Abstract Objective Hypothermic circulatory arrest has been widely used in complex cardiac and aortic surgery. Stroke and/or neurologic injury can occur after prolonged hypothermic circulatory arrest, possibly due to apoptosis. Ischemic preconditioning has been widely used as a neuroprotective tool, but its application in neuronal injury under hypothermic circulatory arrest has never been studied. Methods Forty male New Zealand white rabbits were placed on closed-chest cardiopulmonary bypass, subjected to hypothermic circulatory arrest, and rewarmed to normothermia. Experimental groups were treated with heat shock or ischemic preconditioning before hypothermic circulatory arrest. Hippocampal CA1 neurons were analyzed histopathologically. Apoptosis was confirmed by TUNEL assay and Western blot analysis, and serum S-100β levels, c-Fos and Bcl-2 antibodies, and caspase-3 and heat shock protein 70 levels were measured. Results After 2-hour hypothermic circulatory arrest and 4-hour reperfusion, apoptosis was observed in hippocampal CA1 neurons with elevation of serum S-100β levels, which could be ameliorated by ischemic preconditioning or heat shock manipulations. TUNEL-positive nuclear expression of caspase-3 increased after hypothermic circulatory arrest (3.08% ± 0.71%, P Conclusions Ischemic preconditioning and heat shock can attenuate hippocampal CA1 neuronal apoptosis after prolonged hypothermic circulatory arrest under cardiopulmonary bypass. The expression of heat shock protein 70 may not play a major role in the first window of ischemic preconditioning-induced neuroprotection.
Muslims and the media in the blogosphere

In the past two decades a virtual Ummah has evolved in cyberspace. While some of these websites are targeted specifically at Muslims, others attempt to provide outreach on Islam or counter Islamophobic bias. As noted by Jon Anderson, in his pioneering work on Islam in cyberspace, Muslims were among the first engineering students to create websites at the dawn of the Internet, before mainstream Islamic organizations posted official websites. There is a wealth of material by Muslims in English and Western languages, some of it archived for research. This article explores the methodological problems posed in studying the range of Islam-content blogs, from private individuals to religious scholars, as well as Muslim websites that feature comments from readers. The focus of the paper is an analysis of blogs about Islam or by Muslims that either act as watchdogs on the media or try to provide alternative views to the mainstream media of competing Muslim groups. Researching these blogs as a form of e-ethnography calls for a rethinking and refining of anthropological methodology as e-ethnography.
Revisiting community-based disaster risk management

This paper examines whether the hypothesis presented in Ocho Rios in 1984 is still valid and relevant. The first part of the paper revisits the central tenets of the 1984 paper. The second part of the paper gives a broad overview of how community-based approaches have been taken up and evolved over the last quarter-century. The third part of the paper examines, with the benefit of hindsight, to what extent the approaches advocated in Ocho Rios are still valid. Finally, the paper examines the role of community-based and local-level approaches looking into the future. The paper is written as a personal reflection, without any pretence to academic rigour and also without systematically surveying the thousands of ongoing community-based or local-level initiatives in disaster risk management, referred to in this paper as community-based disaster risk management and local-level disaster risk management, respectively.
Lewis K. Dahl Memorial Lecture: The Renin-Angiotensin System and Aging

Dr Lewis K. Dahl identified many of the relationships that underlie our current thinking and focus of research on hypertension. Among the first to establish the interactions between salt and hypertension, the realization that genetic factors played a major role in how the kidney responded to salt loads1 led to development of the genetically predisposed Dahl salt-sensitive rat. His research, although not specifically directed toward aging, recognized that the effects of high-salt diets were not necessarily immediate. In fact, he suggested that at least one third of the life span was required for salt-induced changes in systolic blood pressure (SBP). I am very grateful for the honor of presenting the Dahl lectureship on work, which, over the past several years, has had aging as the focus. The emphasis has been on the autonomic nervous system, as influenced by the renin-angiotensin system (RAS), specifically, the balance between angiotensin (Ang) II and Ang-(1-7) and the contributions of brain cardiovascular areas to the constellation of changes occurring with advancing age. The overall message derived is that, although the brain RAS plays a major role in all of the age-related changes in cardiovascular and metabolic function, neither the SBP nor the metabolic changes appear to be initiating factors in the activation of the intrarenal RAS or the decline in kidney function during aging (Figure 1). Figure 1. Diagram depicting the proposed relationships among SBP and metabolic dysfunction in the regulation of the intrarenal RAS and renal function during aging. Components of the classical circulating RAS, in particular, renin release from the juxtaglomerular cells of the kidney, undergo a decline in older animals. This includes reductions in renal tissue renin mRNA, juxtaglomerular cell renin content, responsiveness of renin release to various challenges, and plasma renin and angiotensin (Ang) II.2–9 The renal vasoconstrictor responses …
Development of spin resistance criteria for light general aviation airplanes

A brief history of stall/spin technology for light general aviation airplanes is presented. Criteria needed to describe desirable characteristics of a spin-resistant airplane and means to evaluate airplanes for compliance with the criteria have been developed. Initial results from limited flight tests of an experimental high-wing airplane indicated that the basic configuration would not meet the spin resistance criteria. Further tests with the airplane modified to enhance its spin resistance are planned.
Processing of atmospheric nitrogen by clouds above a forest environment

[1] Dissolved inorganic ions (NH4+, Ca2+, Mg2+, K+, H+, NO3−, and SO42−) and organic nitrogen (DON) were measured in cloud water samples collected over the northern lower peninsula of Michigan. Within a given cloud field, several altitudes were sampled to examine changes in concentration and speciation with altitude. Several samples were analyzed for bacterial content and activity. Convective cumulus (cumulus congestus) were more concentrated than fair weather cumulus (cumulus humilis) for all major ions and DON, with the cloudy air DON concentrations in convective cumulus being twice as large as for fair weather cumulus, and for all other ions, the droplets were 4–6 times more concentrated. The molar average distribution of nitrogen in the cloud water was 43 (±10, 1σ)% ammonium, 39 (±7)% nitrate and 18 (±11)% DON. High concentrations of bacteria were observed in the clouds with an average concentration of 2.9 × 105 (±1.0 × 105, 1σ) bacteria m−3 of cloudy air but which contributed less than 1% of the nitrogen in the cloud water. In addition, nitrifying bacteria were identified, indicating bacterial processing of nitrogen in the cloud water may occur. Air mass origin and altitude influence observed cloud water concentrations, with the exception of DON. The correlation of ammonium and sulfate, and calcium and nitrate suggest that ammonium sulfate and calcium nitrate aerosol may be important sources of these ions.
Microstructural and mold resistant properties of environment‐friendly oil‐modified polyurethane based wood‐finish products containing polymerized whey proteins

Environmental concerns associated with the level of volatile organic compounds used in surface coatings have stimulated increased scientific research toward novel methods of developing environment-friendly coatings. Prototype wood finish products containing polymerized whey proteins (PWP) were formulated. The microstructural characteristics of dry films prepared from environment-friendly wood finishes containing PWP were examined using atomic force microscopy (AFM) and confocal laser scanning microscopy (CLSM). The susceptibility of the coatings to microbial degradation was also examined using an accelerated mold test. AFM analysis revealed that increased addition of PWP resulted in films with increased surface roughness, decreased number of voids, and increased void size due to excessive aggregation among polymer components. CLSM analysis showed that the PWP distribution in the films is enhanced by homogenization of the coating mixes. There was no significant increase (P > 0.05) in mold growth between panels coated with finish containing PWP and those without PWP. Test panels coated with formulation containing PWP and low levels of biocide (0.3%) resulted in a significant decrease in mold growth in comparison to commercially available water-based polyurethane coatings (P < 0.05). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3519–3530, 2006
A little VEGF goes a long way. Therapeutic angiogenesis by direct injection of vascular endothelial growth factor-encoding plasmid DNA.

Local production of small amounts of a potent, secreted growth factor with built-in specificity for endothelial cells may bypass the need for highly efficient gene transfer vectors and elaborate treatment protocols to produce effective therapeutic angiogenesis in ischemic peripheral vascular disease. That is the message of a report by Tsurumi et al that appears in this issue of Circulation 1 in which naked plasmid DNA encoding the 165–amino acid secreted form of human vascular endothelial growth factor (hVEGF-165) is introduced by direct intramuscular injection into ischemic rabbit hindlimbs. Thirty days after injection of 100 μg hVEGF-165 plasmid DNA at each of five sites within ischemic hindlimb muscles, increased collateral vessel formation, improved blood flow, and an increased number of capillary profiles could be demonstrated compared with control hindlimbs that received injections of plasmid DNA only. The simplicity of the gene transfer approach described in this study suggests a potentially useful alternative for patients with extensive peripheral vascular disease in whom intravascular angioplasty catheter–based gene delivery methods are inadvisable or not possible. VEGF was discovered in the early 1980s by Dvorak and coworkers as a factor that made blood vessels leaky; hence, it was given the name of vascular permeability factor (VPF).2 3 Then, in the late 1980s, several groups showed that VEGF/VPF stimulated endothelial cell migration and replication and was a potent angiogenic factor in vivo.4 5 6 VEGF is a heat-stable, 46-kD dimeric protein with structural similarity to placenta growth factor (PlGF) (≈53% amino acid identity) and more distant homology (18% to 20%, including all eight cysteines) to the platelet-derived growth factor family (for review, see Reference 6). VEGF is made by many different cell types, and its production is upregulated in hypoxic tissues.7 Indeed, a 28-bp element has been identified in the promoter region of …
Reservoir stimulation and induced seismicity: Roles of fluid pressure and thermal transients on reactivated fractured networks

Abstract We utilize a continuum model of reservoir behavior subject to coupled THMC (thermal, hydraulic, mechanical and chemical) processes to explore the evolution of stimulation-induced seismicity and related permeability in EGS reservoirs. Our continuum model is capable of accommodating changes in effective stresses that result due to the evolving spatial variations in fluid pressure as well as thermal stress and chemical effects. Discrete penny-shaped fractures (∼10–1200 m) are seeded within the reservoir volume at both prescribed (large faults) and random (small fractures) orientations and with a Gaussian distribution of lengths and location. Failure is calculated from a continuum model using a Coulomb criterion for friction. Energy release magnitude is utilized to obtain the magnitude-moment relation for induced seismicity by location and with time. This model is applied to a single injector (stimulation) to the proposed Newberry EGS field (USA). Reservoir stimulation is assumed to be completed in four zones at depths of 2000, 2500, 2750 and 3000 m. The same network of large fractures (density of 0.003 m −1 and spacing 300 m) is applied in all zones and supplemented by more closely spaced fractures with densities from 0.26 m −1 (deepest zone) through 0.5 m −1 (shallow zone) to 0.9 m −1 (intermediate depth zone). We show that permeability enhancement is modulated by hydraulic, thermal, and chemical (THMC) processes and that permeability increases by an order of magnitude during stimulation at each depth. For the low density fracture networks, the increase in permeability reaches a smaller radius from the injection point and permeability evolution is slower with time compared to the behavior of the higher density fracture network. For seismic events that develop with the stimulation, event magnitude ( M s ) varies from −2 to +1.9 and the largest event size (∼1.9) corresponds to the largest fractures (∼1200 m) within the reservoir. We illustrate that the model with the highest fracture density generates both the most and the largest seismic events ( M s = 1.9) within the 21 day stimulation. Rate of hydraulic and thermal transport has a considerable influence on the frequency, location and time of failure and ultimately event rate. Thus the event rate is highest when the fracture network has the largest density (0.9 m −1 ) and is located at depth where the initial stresses are also highest. Also apparent from these data is that the closely spaced fracture network with the higher stress regime (at the deeper level) has the largest b -value ∼0.74.
Failure of strong asymptotic conditions in four-dimensional field theories†

It is shown that the renormalization group imposes severe restrictions on analytic continuation in coupling constant in the case of field theories in four dimensions.
Oxidative transformation of fluoroquinolone antibacterial agents and structurally related amines by manganese oxide.

Various members of the popular fluoroquinolone antibacterial agents (FQs) have been frequently detected in municipal wastewater and surface water bodies in recent years. This study was conducted to gain a better understanding of the fate of FQs in the sediment−water environment. Seven FQs were examined for adsorptive and oxidative interactions with δ-MnO2 under environmental conditions and exhibited reactivity in the order of ciprofloxacin ∼ enrofloxacin ∼ norfloxacin ∼ ofloxacin > lomefloxacin > pipemidic acid ≫ flumequine. Four amines that are structurally related to the aniline and piperazine functional groups of FQs showed reactivity to oxidation by δ-MnO2 in the order of 1-phenylpiperazine > aniline > N-phenylmorpholine > 4-phenylpiperidine. Comparison among the above compounds clearly indicates that the piperazine moiety of FQs is the predominant adsorptive and oxidative site to MnO2. Product analyses showed that oxidation by MnO2 results in dealkylation and hydroxylation at the piperazine moiety of...
Ground state of a spin-phonon system. III: Small-B limit

The ground state of the spin-one-half acoustic phonon system is studied in the limitB≪1. The technique is to combine the Brillouin-Wigner variational perturbation theory with a source canonical transformation. With theB=0 source transform the energy is calculated as a function of coupling constant through terms of orderB 2. To this order there is no phase transition. The theory gives the crossover from perturbation theory to an improved classical theory with quantum fluctuations. With a source transform with a nonzero inverse lengthβ the energy estimate is further improved to next order in the coupling constant and for larger values ofB. The soft, infinite-order transition of the modified source theory is removed in the limitB≪1.
Effect of Undercut Etch on Performance and Fabrication Robustness of Metal-Clad Semiconductor Nanolasers

We use optical, thermal, and electrical simulation to evaluate the effects of using varying amounts of undercut etch on wavelength-scale and subwavelength metal-clad semiconductor nanolasers (MCSELs). We find that as MCSEL diameter decreases, the optical performance becomes more sensitive to slight amounts of sidewall tilt. A modest amount of undercut (25%) dramatically improves the optical performance, reducing modal threshold gain to 100 $\mathrm{cm}^{-1}$ or less for lasers with core radius of 225, 550, or 775 nm, even in the presence of significant sidewall tilt (20° gain sidewall or ±8° pedestal sidewall tilt). Finally, we examine the effects of the increased undercut on nanolaser thermal performance and find that the increased resistive heating is insignificant near threshold, even for subwavelength nanolasers.
Novel pressure-induced interactions in silane-hydrogen.

We report novel molecular compound formation from silane-hydrogen mixtures with intermolecular interactions unprecedented for hydrogen-rich solids. A complex ${\mathrm{H}}_{2}$ vibron spectrum with anticorrelated pressure-frequency dependencies and a striking H-D exchange below 10 GPa reveal strong and unusual attractive interactions between ${\mathrm{SiH}}_{4}$ and ${\mathrm{H}}_{2}$ and molecular bond destabilization at remarkably low pressure. The unique features of the observed ${\mathrm{SiH}}_{4}({\mathrm{H}}_{2}{)}_{2}$ compound suggest a new range of accessible pressure-driven intermolecular interactions for hydrogen-bearing simple molecular systems and a new approach to perturb the hydrogen covalent bond.
Emission-based attenuation correction of myocardial perfusion studies.

Nonuniform attenuation in the thorax can generate artifacts in single-photon emission computed tomographic myocardial perfusion studies that mimic coronary artery disease. In this article we present both phantom and simulation data, as well as clinical data, in support of an emission-based method that provides reliable correction for attenuation effects without the need for a transmission measurement. The attenuation map is derived from the measured distribution of 99mTc-labeled macroaggregated albumin in the lungs and a radioactive binder wrapped about the thorax. This information is acquired as part of a dual-isotope acquisition during the rest 201TI study. Segmentation is used to define the interiors of lung and body compartments, which are assigned a single attenuation coefficient for each of the two tissue types. The appropriateness of this approach was investigated by examining the measured attenuation coefficients in a group of 80 individuals (40 male, 40 female) from positron emission tomographic transmission studies. The correction technique was evaluated with computer simulations, a physical phantom, and clinical data acquired from 20 patients. Analysis of the positron emission tomographic data found a small SD in the mean attenuation coefficients for the body (<5%) and lungs (<15%). The application of emission-based attenuation-correction technique produced a substantial reduction in the magnitude of the attenuation artifact in images obtained from both the phantom and the simulation studies. The emission-based attenuation-correction technique was easily applied to myocardial perfusion studies, where it had a significant effect, resulting in changes in interpretation for nine of 20 patients. The results of this study provide strong support for the concept that an attenuation map can be generated with fixed attenuation values in place of those that are directly measured. Thus the emission-based attenuation-correction technique can be considered an inexpensive alternative to transmission-based correction methods. Because the emission-based correction technique does not require any additional hardware, it has the major advantage of being applicable to all single-photon emission computed tomographic systems.
Analysis of migratory behavior of neural crest and fibroblastic cells in embryonic tissues

Abstract The precise migration of neural crest cells is apparently controlled by their environment. We have examined whether the embryonic tissue spaces in which crest cells normally migrate are sufficient to account for the pattern of crest cell distribution and whether other migratory cells could also distribute themselves along these pathways. To this end, we grafted a variety of cell types into the initial crest cell migratory pathway in chicken embryos. These cell types included (a) undifferentiated neural crest cells isolated from cultured neural tubes, intact crest from cranial neural folds, and crest derivatives (pigment cells and spinal ganglia); (b) normal embryonic fibroblastic cells from somite, limb bud, lateral plate, and heart ventricle; and (c) a transformed fibroblastic cell line (Sarcoma 180). Crest cells or their derivatives grafted into the crest migratory pathway all distributed normally, although in contrast to the result when neural tubes were grafted in situ , fewer cells were observed in the epithelium and few or none were localized in the nascent spinal ganglia. Grafted quail somite cells contributed to normal somitic structures and did not migrate extensively in the chicken host. Other fibroblasts did not migrate along cranial or trunk crest pathways, or invade adjacent tissues, but remained intact at the graft site. Sarcoma 180 cells, however, distributed themselves along the normal trunk crest pathway. Cranial and trunk crest cells and crest derivatives grafted ectopically in the limb bud or somite also dispersed, and were found along the ventral migratory pathway. Fibroblastic cells grafted into ectopic sites again remained intact and did not invade host tissue. We conclude (1) that neural crest cells and their derivatives are highly motile and invasive in their normal pathway, as well as in unfamiliar embryonic environments; and (2) that the crest pathway does not act solely to direct neural crest cells, since at least one transformed cell can follow the crest migratory route.