cssi/SciSciGPT-SciSciNet huggingface dataset:
Reactive sintering of TiAl–Ti5Si3 in situ composites

TiAl with between 0 and 20 vol%Ti5Si3 was produced by reactive sintering (700 °C for 15 min in vacuum) of cold pressed compacts of elemental Ti, Al and Si powder. The results show that adding Si to Ti and Al reduces the swelling associated with reactive sintering of TiAl, as composites containing more than 5 vol%Ti5Si3 densified during reactive sintering. However, composites containing more than 10 vol%Ti5Si3 did not retain their shape and the TiAl+20 vol%Ti5Si3 composite completely melted during the sintering process. A thermodynamic analysis indicated that the simultaneous formation of TiAl and Ti5Si3 increases the adiabatic flame temperature during the reaction between the powders. In fact, the analysis predicted that the maximum temperature of the reaction associated with the formation TiAl+20 vol%Ti5Si3 should exceed the melting point of TiAl, and this was observed experimentally. Differential thermal analysis (DTA) revealed that an Al–Si eutectic reaction occurred in mixtures of Ti, Al and Si powders prior to the formation of the TiAl and Ti5Si3 phases. There was no such pre-reaction formation of a eutectic liquid in Ti and Al powder mixtures. The formation of the pre-reaction liquid and the increase in adiabatic flame temperature resulted in the melting that occurred and the enhanced densification (minimization of swelling) during reactive sintering of the in situ composites.
Perspectives on the renin-angiotensin-aldosterone system in hypertension.

Abstract In the syndrome of hyperaldosteronism, the abnormal electrolyte metabolism, secondary to mineralocorticoid excess, seems to play a predominant pathogenetic role in causing elevation of the blood pressure, since the renin-angiotensin system is depressed and unresponsive. The available evidence (results of treatment, consistent failure to cause high blood pressure by administration of excessive salt-remaining steroids to normotensive volunteers, the salt-hypertension model in experimental animals, the higher incidence of adrenal adenomas in hypertensive patients, etc.), however, suggests that other factors participate in the mechanism of hypertension. Angiotensin II stimulates aldosterone secretion, thereby affecting electrolyte balance; in addition, this polypeptide is the most powerful vasoconstrictor known today, the effectiveness of which is greater in a Na-replete condition. In some hypertensive states (renovascular hypertension, end-stage renal disease, malignant phase hypertension, hypertension related to oral-contraceptive medication, and primary reninism) both the renin-angiotensin system and aldosterone production may be elevated. In this group, however, correlation between the latter two variables and hypertension is not sufficiently consistent to implicate them as the sole pathogenetic factors. In the larger group of patients with essential hypertension, the renin-angiotensin-aldosterone system and electrolyte metabolism range from normal to subtle changes (depressed plasma renin, incomplete aldosterone suppression by salt load, decrease in aldosterone metabolism, exaggerated natriuresis, reversal of electrolyte circadian cycle) of difficult interpretation. We suggest that the same factors, clearly abnormal in hypertensive states of more defined etiology, are also at play in causing essential hypertension, perhaps through some as yet undefined abnormal interrelationship.
Dissociation in virtual reality: depersonalization and derealization

This paper looks at virtual worlds such as Second Life7 (SL) as possible incubators of dissociation disorders as classified by the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition3 (also known as the DSM-IV). Depersonalization is where "a person feels that he or she has changed in some way or is somehow unreal." Derealization when "the same beliefs are held about one's surroundings." Dissociative Identity Disorder (DID), previously known as multiple personality disorder fits users of Second Life who adopt "in-world" avatars and in effect, enact multiple distinct identities or personalities (known as alter egos or alters). Select questions from the Structured Clinical Interview for Depersonalization (SCI-DER)8 will be discussed as they might apply to the user's experience in Second Life. Finally I would like to consider the hypothesis that rather than a pathological disorder, dissociation is a normal response to the "artificial reality" of Second Life.
Status of the Tokamak Fusion Test Reactor (TFTR)

The Tokamak Fusion Test Reactor (TFTR). the key toroidal confinement device of the US fusion energy research program, is directed toward the goal of demonstrating energy break-even under DT conditions by 1988. TFTR now is completing its second year of research operation. In this period it has extended the study of scaling in ohmic heated plasmas and found scaling to vary with the cube of length including observations relative to that of the Princeton Large Torus (PLT) tokamak; it has explored impurity effects and the influence of neutral beam heating on confinement. The ongoing experimental campaign is being conducted with plasma/machine parameters up to BT ~ 40 kG, Ip ~ 1.5 MA, PNB ~ 2 MW(H) and τNB ~ 0.3 s with τc up to 0.3 s. With completion of this two year start-up phase the TFTR will be operated for a two-year period of machine optimization concluding with Q ~ 1 for DD operation, followed by a two year phase of plasma optimization culminating with DT operation at Q ~ 1 in 1988. A subsequent phase of D-T research is under consideration.
Tissue fluid pressures: from basic research tools to clinical applications

This paper describes clinical applications of two basic research tools developed and refined in the past 20 years: the wick catheter (for measuring tissue fluid pressure) and the colloid osmometer (for measuring osmotic pressure). Applications of the osmometer include estimations of the reduced osmotic pressure of sickle-cell hemoglobin with deoxygenation, and of reduced swelling pressure of human nucleus pulposus with hydration or upon action of certain enzymes. Clinical uses of the wick-catheter technique include an improvement of diagnosis and treatment of acute and chronic compartment syndromes, the elucidation of the tissue pressure thresholds for neuromuscular dysfunction, and the development of a better tourniquet for orthopedics.
Nonlinear Response of a Taut String to Longitudinal and Transverse End Excitation

The nonlinear response of a taut string to an end excitation with components both parallel and transverse to its axis is theoretically and experimentally studied. A model for the transverse vibration of the string is developed by neglecting its longitudinal inertia. The method of multiple scales is applied directly to the governing partial-differential equations and boundary conditions. A continuation method is then employed to determine the constant amplitude and phase solutions and their stability. Resonant responses are predicted to occur simultaneously in as many as three modes. An experimental study is conducted and the results are found to be in good agreement with the theory.
On the Smale theorem in weak shape theory

We modify various lemmas from Dydak's paper on the Vietoris-Smale theorem to obtain more general results. We consider closed subsets X and Y of paracompact spaces M, N respectively, and a map F:M→N such that F∥X:X→Y is closed and surjective and X=F-1(Y) to obtain the following result. (Theorem). If F-1(y)ϵACnM(K) for each y ϵ Y and N is LCn+1, then the morphism in-pro-πk[F]:πkUKM(X,x)→πkUKN(Y,y) induced by the morphism [F]:UKM(X,x)→UKN(Y,y) is an isomorphism of in-pro-Grp for k⩽n and an epimorphism for k=n+1.
First-principles calculation of optical properties of C60 in the fcc lattice.

The electronic and optical properties of C{sub 60} in the fcc lattice have been studied by a first-principles method. It is shown that C{sub 60} has a low dielectric constant and an optical spectrum rich in structures; this is drastically different from diamond and graphite. The spectrum shows five disconnected absorption bands in the 1.4 to 7.0 eV region with sharp structures in each band that can be attributed to critical-point transitions. This is a manifestation of the localized molecular structure coupled with long-range crystalline order.
Idiotype selection is an immunoregulatory mechanism which contributes to the pathogenesis of systemic lupus erythematosus

Abstract Several experiments are reviewed to support the following suggestions: (1) Idiotypes can be used to identify pathogenic autoantibodies in murine and human systemic lupus erythematosus; (2) Those idiotypes are targets for immune upregulation which causes them to expand and dominate immunoglobulin responses; (3) Those idiotypes require autoreactive T-cell help; and (4) Both T cells and B cells participating in this response are polyclonal. These observations are used to construct an hypothesis to explain the sustained production of pathogenic autoantibody subsets.
Distributed beamforming with software-defined radios: Frequency synchronization and digital feedback

We present an implementation of distributed transmit beamforming using software-defined radios. The transmit nodes synchronize in carrier frequency using a pilot signal sent by a master node, and employ feedback from the receiver to adjust their carrier phases so as to add up coherently at the receiver. Our implementation advances the state of the art for all-wireless distributed beamforming in two important ways. The first is the implementation of extended Kalman filters for frequency synchronization at the slave nodes, which is shown to be effective despite the high local oscillator (LO) offsets typical of software-defined radios, and the low duty cycle of the pilot transmitted by the master node. The second advance is the implementation of the well-known one bit feedback scheme for phase adjustment using digital feedback from the receiver. We present experimental results that show the efficacy of our implementation for frequency synchronization and beamforming.
Assessment of Atherosclerosis in Chronic Granulomatous Disease

Background— Patients with chronic granulomatous disease (CGD) experience immunodeficiency because of defects in the phagocyte NADPH oxidase and the concomitant reduction in reactive oxygen intermediates. This may result in a reduction in atherosclerotic injury. Methods and Results— We prospectively assessed the prevalence of cardiovascular risk factors, biomarkers of inflammation and neutrophil activation, and the presence of magnetic resonance imaging and computed tomography quantified subclinical atherosclerosis in the carotid and coronary arteries of 41 patients with CGD and 25 healthy controls in the same age range. Univariable and multivariable associations among risk factors, inflammatory markers, and atherosclerosis burden were assessed. Patients with CGD had significant elevations in traditional risk factors and inflammatory markers compared with control subjects, including hypertension, high-sensitivity C-reactive protein, oxidized low-density lipoprotein, and low high-density lipoprotein. Despite this, patients with CGD had a 22% lower internal carotid artery wall volume compared with control subjects (361.3±76.4 mm3 versus 463.5±104.7 mm3; P <0.001). This difference was comparable in p47phox- and gp91phox-deficient subtypes of CGD and independent of risk factors in multivariate regression analysis. In contrast, the prevalence of coronary arterial calcification was similar between patients with CGD and control subjects (14.6%, CGD; 6.3%, controls; P =0.39). Conclusions— The observation by magnetic resonance imaging and computerized tomography of reduced carotid but not coronary artery atherosclerosis in patients with CGD despite the high prevalence of traditional risk factors raises questions about the role of NADPH oxidase in the pathogenesis of clinically significant atherosclerosis. Additional high-resolution studies in multiple vascular beds are required to address the therapeutic potential of NADPH oxidase inhibition in cardiovascular diseases. Clinical Trial Registration— URL: . Unique identifier: [NCT01063309][1]. # CLINICAL PERSPECTIVE {#article-title-52} [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT01063309&atom=%2Fcirculationaha%2F130%2F23%2F2031.atom
The critical window for the classical Ramsey-Turán problem

The first application of Szemeredi's powerful regularity method was the following celebrated Ramsey-Turan result proved by Szemeredi in 1972: any K4-free graph on n vertices with independence number o(n) has at most $$(\tfrac{1} {8} + o(1))n^2$$ edges. Four years later, Bollobas and Erd?s gave a surprising geometric construction, utilizing the isoperimetric inequality for the high dimensional sphere, of a K4-free graph on n vertices with independence number o(n) and $$(\tfrac{1} {8} - o(1))n^2$$ edges. Starting with Bollobas and Erd?s in 1976, several problems have been asked on estimating the minimum possible independence number in the critical window, when the number of edges is about n2/8. These problems have received considerable attention and remained one of the main open problems in this area. In this paper, we give nearly best-possible bounds, solving the various open problems concerning this critical window.
Competitive channels in the jet-cooled photodissociation of the CH2Cl radical

Abstract The photodissociation of CH2Cl is studied by the ion imaging technique. At 235–243 nm, Cl photofragments are produced via the simultaneous excitation of the perpendicular (1 2 A 1 ←1 2 B 1 ) and parallel (2 2 B 1 ←1 2 B 1 ) electronic transitions. The relative populations and translational energy distributions of Cl fragments generated via each transition are extracted. H-atom products, which are detected in a one-color experiment at 243.1 nm, exhibit an angular distribution characteristic of perpendicular transitions only. They may be produced via excitation to the valence 1 2 A 1 and/or Rydberg 2 2 A 1 (3s) states.
Identity and Competence: The Use of Culture in the Interpretation of Sexual Images

Cultural sociology agrees that meanings attributed to objects vary depending upon the cultural competencies of viewers, but tends to ignore the role of identities in interpretation. This article argues that both identities and competencies influence interpretation. Through an analysis of how 307 undergraduate students at a Midwestern state university interpreted a black-and-white photograph of an individual masturbating, this article finds that assessments of the degree to which the image should be considered art and/or pornography are associated with self-reported indicators of both cultural competencies and identities. Indicators of religious and conventional identities and of training with regard to photography stand out in this regard. The intersection of the constructions of pornography and art enabled the authors to classify participants as Nonartistic Conservatives, Nonartistic Liberals, Artistic Liberals, and Artistic Conservatives and to show that interpretations are a consequence of how persons ...
Theory of Exchange-Narrowed Magnetic-Resonance Linewidth at Finite Temperature

General formulas are derived for the width of an exchange-narrowed magnetic-resonance absorption line at a finite temperature where the Zeeman and/or exchange energies can be comparable to the thermal energy $\mathrm{kT}$. The perturbation which gives rise to line broadening also is allowed to be comparable to $\mathrm{kT}$ in our treatment, and this marks a departure from previous theories of exchange narrowing. The relaxation-function approach of Kubo and Tomita is used, and it is assumed, as in the infinite-temperature limit, that the appropriate correlation times are sufficiently short. We show that the correlation function $〈{M}_{x}(t){M}_{x}(0)〉$ of the $x$ component of the magnetization has an apparent relaxation rate which is given by an obvious extension of the Van Vleck moments formula to finite temperature. This relation holds for an arbitrary ratio of perturbation energy to $\mathrm{kT}$. However, it appears that only if the perturbation energy is much less than $\mathrm{kT}$ can this relaxation function be simply related to ${\overline{M}}_{x}(t)$, which describes relaxation of the macroscopic magnetization. If this is the case, then an unambiguous result for the linewidth is obtained which is clearly related to Van Vleck's infinite-temperature theory.
Does water use restrict the location of industrial air polluters

The paper examines water use in industrial production as a cause of geographical clustering of major air polluting industries. It shows that the majority of particulate and sulfur oxide emissions in the State of Illinois is emitted by industries using more than five billion liters of water per establishment per year. It also shows that the majority of industrial air pollutants is emitted within urban areas which are on water bodies with high and consistent volumes of water available. These and other results cited in the paper imply that any policy directly or indirectly promoting geographic dispersal as a means of reducing air pollution concentrations and population exposure rates is likely to be limited in effectiveness. It is suggested that such a policy can be effective only if at least one of two specified conditions is met. However, these conditions do not, by themselves, insure the success of such a policy. Finally, it is observed that the conjunction of air pollution with industrial water use indicates that much closer attention is needed to the relationship between air pollution and water pollution policies.
Assessing the solubility of inorganic compounds from size-segregated coal fly ash aerosol impactor samples

An important issue for the coal-fired utility industry is the release of heavy metals contained in fly ash. Before companies can plan emission minimization strategies for these compounds, they must have an accurate means of predicting the forms of occurrence in the waste stream and the solubility of these forms into the surrounding environment. The EPA's Toxicity Characterization Leaching Protocol (TCLP) Method 1310 was modified to allow the testing of inorganic compounds contained on greased impactor membranes. The modified method was used to explore the solubility of four trace elements from five different types of coal fly ash. For most coals, selenium has limited solubility at pH 5.0 and is not expected to significantly impact groundwater sources. Arsenic, antimony, and cobalt are typically partially soluble at pH 5.0 and a portion of these metals may migrate out of the ash particles. Further, these metals show increased solubility at pH 2.9.
Thermal stresses in a multilayered thin film thermoelectric structure

Abstract This work investigates thermally induced stresses and deformations in a multilayered thin film thermoelectric (TE) structure for assessing thermomechanical reliability of the TE devices. The multilayered structure consists of a n-type and p-type thermocouple separated by an insulating layer, and an additional supporting membrane layer. The one-dimensional thermoelectricity is used to compute the temperature distribution with heat transfer by radiation and convection at the film surfaces being considered. The thermoelasticity theory of laminated composites is employed to determine the stresses and deformations in the thin film structure. It is found that the thermal stress calculated using the present laminate model has a significantly higher magnitude than that predicted by the strength of materials model. Effects of heat transfer coefficient at the film surfaces are also examined.
Prevention of vaccinia virus infection in imiminodeficient mice by vector-directed IL-2 expression

Recombinant vaccinia viruses have been proposed as live vaccines against a variety of infectious diseases, including AIDS (acquired immune deficiency syndrome)1. Objections have been concerned primarily with side effects of the vaccinia virus vector itself. Recently it has been shown that inactivation of the vaccinia virus thymidine kinase gene or deletion of certain other non-essential genes is associated with a marked reduction in pathogenicity2. Nevertheless, the ability of vaccinia virus to produce a progressive infection in immunodeficient individuals remains a most serious problem. Indeed, an incident of this type in a vaccinated man seropositive for human immunodeficiency virus was recently reported3. We have used immunodeficient athymic nude mice to establish a model of disseminated vaccinia virus infection, and to demonstrate a novel approach to virus attenuation which involves insertion of a gene encoding human interleukin-2 into the genome of vaccinia virus vectors.
Wavelets and power system transients: feature detection and classification

This paper presents a methodology for the development of software for classifying power system disturbances by type from the transient waveform signature. The implementation of classification capability in future transient recorders will enable such features as selective storage of transient data (to better utilize limited storage media) and automated reporting of disturbances to central control facilities. The wavelet transform provides an effective and efficient means of decomposing voltage and current signals of power system transients to detectable and discriminant features. Similarities of power system transients to wide-band signals in other domains, the simultaneous presence of a resonant frequency, its harmonics, and impulse (high-frequency, time-localized) components, make this technique extendible to other classification systems. The classification algorithm uses statistical pattern recognition on features derived from the extreme representation of the transient waveform after processing the transient waveform by a non-orthogonal, quadratic spline wavelet. Training and classification testing use simulated waveforms of a 200 mile, three-phase transmission line produced by the Electromagnetic Transients Program (EMTP). A simple Bayesian classifier identifies an unknown transient waveform as a capacitor switching or fault transient, and locates the point of disturbance from one of two possible locations on the transmission line. Due to the effectiveness of the wavelet transform preprocessing, the classification system currently performs at 100 percent accuracy on four transient classes.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Embracing Strategies While Avoiding Bandwagons in the Design of Manufacturing and Quality Systems

In this article, the authors make the observation that North American manufacturers often follow major trends in manufacturing or quality management strategies. This is not necessarily bad policy if these trends support long-term business objectives as ..
Minimal features of paxillin that are required for the tyrosine phosphorylation of focal adhesion kinase

Tyrosine phosphorylation of FAK (focal adhesion kinase) regulates signalling that results from the interaction of integrins with extracellular matrix and growth factor receptors. A critical step in this process is the phosphorylation of Tyr397 of FAK, which creates a binding site for Src family kinases, PI3K (phosphoinositide 3-kinase) and Shc (Src homology and collagen homology). An intact Tyr397 site is required for FAK-mediated regulation of cell migration, survival signals and full responsiveness to soluble growth factors. We showed previously that the adaptor protein paxillin is required for the overall tyrosine phosphorylation of FAK in embryonic stem cells [Wade, Bohl and Vande Pol (2002) Oncogene 21, 96-107]. In the present paper, we identify the minimal structural features of paxillin that are required to support overall FAK tyrosine phosphorylation and Tyr397 phosphorylation. Paxillin contains N-terminal leucine-rich LD motifs that bind directly to FAK and four LIM (Lin-11, Isl-1 and Mec-3) domains in the C-terminus. We show that paxillin LIM domains 1, 2 and 3 are each required for FAK tyrosine phosphorylation, while LIM4 is dispensable. In addition to paxillin LIM domains 1, 2 and 3, a single LD motif on paxillin is required to support FAK tyrosine phosphorylation in embryonic stem cells. Both sequence and spatial requirements exist for LD motifs to support FAK tyrosine phosphorylation. Interestingly, synthetic LD motifs that fail to bind FAK in vitro are able to fully support FAK tyrosine phosphorylation, indicating that minimal interactions of LD motifs with FAK suffice. Our results demonstrate at least four distinct structural domains of paxillin support at least three distinct functions that are each required for FAK tyrosine phosphorylation.
Electron bunching and output gap interaction in broad-band klystrons

Broad-band klystron operation is investigated using a large-signal digital computer simulation of electron bunching and output gap interaction. Electron bunching is examined as a function of beam voltage and perveance for a prototype series of klystrons. The development of a low energy "spur" of electrons is shown to limit efficiency at high perveance, particularly at the high band edge. The output gap interaction is computed in a broad fashion so that klystron performance can be evaluated for a variety of cold output cavity impedances. Application is made to a practical commercial klystron. Measured klystron efficiency is shown to agree well with computed efficiency over most of the frequency band. The limitations of using the "merit figure" concept for efficiency are discussed.
Mesenchymal stem cells: Will they have a role in the clinic?

In addition to hematopoietic stem cells (HSC), human post natal bone marrow contains another stem cell capable of giving rise to multiple mesenchymal cell lineages. Termed mesenchymal stem cells (MSCs) based on their capacity for multi-lineage differentiation, these cells can easily be obtained following a simple bone marrow aspiration procedure and subsequently expanded in culture through as many as 50 population doublings. This extensive capacity for expansion in vitro at clinical scale has recently facilitated the development of clinical trials designed to assess the safety, feasibility, and efficacy of transplanting MSC for a variety of pathological conditions. This review focuses on the background and rationale for performing clinical studies of MSC transplantation and will discuss the potential role that MSC may play in the correction or modification of human diseases.
Endogenous opioid peptides and the control of the menstrual cycle

This paper reviews recent experimental evidence which supports a role for endogenous opioid peptides in the control of gonadotropin function. In primates, cell bodies containing endogenous opioid peptides have been located within the hypothalamus in areas rich in gonadotropin-releasing hormone (GnRH) and dopamine. The release of beta-endorphin from these hypothalamic neurons is influenced by gonadal steroids, maximal release being observed when both estradiol and progesterone are present. beta-Endorphin has been shown to decrease LH secretion, and naloxone, an opiate antagonist, reverses this action. The LH-releasing activity of naloxone parallels variations in hypothalamic beta-endorphin secretory activity, so that maximal effects are seen during the luteal phase of the cycle. Present evidence indicates that opiates exert their effect on LH via a hypothalamic site. It is concluded that increased opioid inhibition of the GnRH-LH axis is responsible for the decline in LH pulse frequency during the luteal phase. The studies provide evidence for a chemical basis rationalizing relationships between reproductive function and stress, and have further implication on other forms of amenorrhea.
Fitness Epistasis among 6 Biosynthetic Loci in the Budding Yeast Saccharomyces cerevisiae

We generated all possible haploid and homozygous diploid genotypes at 6 biosynthetic loci in yeast and scored their fitness to examine whether there was any pattern of weak synergistic epistasis, which is a requirement of the deterministic mutation model for the evolution of sex. We measured 4 components of fitness: haploid growth rate, haploid mating efficiency, diploid growth rate, and diploid sporulation efficiency. We found that in agreement with previous work in yeast, epistasis tended to be small in magnitude and variable in sign, regardless of the fitness component measured. The number of background mutations had either no effect or no consistent effect on epistasis distributions. For every combination of 2 loci in a mutation-free background, we also generated all heterozygous genotypes so that we could partition diploid epistasis into additive x additive, additive x dominance, and dominance x dominance epistasis. Our main interest was in determining whether dominance by dominance epistasis was large and negative, which is a requirement of diploid models with inbreeding to explain high levels of recombination. Dominance by dominance epistasis estimates obtained by partitioning diploid epistasis for growth rates were both positive and negative. With the caveat that our results are based on only 6 biosynthetic loci, epistasis for fitness is not supported as an explanation for the maintenance of sex or the high rate of meiotic recombination in yeast.
Physiological Ecology of a Gliding Bacterium Containing Bacteriochlorophyll a

A filamentous, gliding, thermophilic bacterium, found growing abundantly as a surface mat in a limited number of alkaline hot springs in Oregon, is described and designated F-1. The bacteria were studied in the field and in coculture with an aerobic chemoheterotroph. The bacteria are phototrophic and contain bacteriochlorophyll a and several carotenoid pigments. Unlike the other gliding phototrophic bacteria, members of the family Chloroflexaceae, F-1 does not contain chlorosomes or bacteriochlorophyll c or d. The light-dependent uptake of simple organic compounds (acetate and glucose) was demonstrated in field populations. Near-infrared radiation sustained this uptake, which occurred equally well under aerobic or anaerobic conditions and was insensitive to 3-(3,4-dichlorophenyl)-1,1-dimethylurea. The bacteria formed conspicuous dominant mats from about 35 to 56 degrees C, and they covered mats of cyanobacteria in the spring, summer, and autumn months. It appears that they depend on high light intensities to maintain a dense population.
Enantiomerically pure vinylketene acetals in the Diels-Alder reaction. Catalysis and facial selectivity.☆

Abstract A series of enantiomerically pure vinylketene acetals which function as diastereoselective dienes in the Diels-Alder reaction have been developed. Most selective are (4 R , 5 R )-4,5-diphenyl-2-(2-methyl-2-propenidene)-1,3-dioxolane ( 8 ) and (4 R , 5 R )-4,5-diphenyl-2-(( E )-2-butenidene)-1,3-dioxolane ( 9 ), which utilize phenyl rings as asymmetric directing groups. It was shown through NOE analysis that the major product obtained from the reaction of diene 9 and N -methylmaleimide is due to Re exo approach of the dienophile to the diene, with the two endo transition states also being manifest in the product mixture in small amounts. The relative order of the transition state energies were determined to be Re exo Re endo Si endo Si exo . Both molecular mechanics and π-charge density calculations were used to rationalize the high level of diastereoselectivity observed in the reactions of diene 8 and N -methylmaleimide (48:1).
Multiuser switched scheduling systems with per-user threshold and post-user selection

A multiuser switched diversity scheduling scheme with per-user feedback threshold is proposed in this paper. Unlike the conventional multiuser switched diversity scheduling scheme where a single threshold is used by all the users in order to determine whether to transmit a feedback, the proposed scheme deploys per-user threshold, where each user uses a potentially different threshold than other users thresholds. This paper first provides a generic analytical framework for the optimal feedback thresholds in a closed form. Then we investigates the impact of user sequence strategies and post selection strategies on the performance of the multiuser switched scheduling scheme with per-user threshold. Numerical and simulation results show that the proposed scheme provides a higher system capacity compared to the conventional scheme.
Programmable Microcapsules from Self-Immolative Polymers

For the autonomous repair of damaged materials, microcapsules are needed that release their contents in response to a variety of physical and chemical phenomena, not just by direct mechanical rupture. Herein we report a general route to programmable microcapsules. This method creates core-shell microcapsules with polymeric shell walls composed of self-immolative polymer networks. The polymers in these networks undergo a head-to-tail depolymerization upon removal of the triggering end group, leading to breakdown of the shell wall and subsequent release of the capsule's liquid interior. We report microcapsules with shell walls bearing both Boc and Fmoc triggering groups. The capsules release their contents only under conditions known to remove these triggering groups; otherwise, they retain their contents under a variety of conditions. In support of the proposed release mechanism, the capsule shell walls were observed to undergo physical cracking upon exposure to the triggering conditions.
The Targeted Synthesis of Single Site Vanadyl Species on the Surface and in the Framework of Silicate Building Block Materials

A new synthetic methodology for the targeted preparation of single site, atomically dispersed vanadyl groups in silicate matrices is described. This methodology requires functionalized silicate building blocks Si{sub 8}O{sub 20}(OSnMe{sub 3}){sub 8} that become linked together through vanadyl ({triple_bond}V=O) groups in the matrix. A sequential addition strategy is illustrated which allows the targeting of specific connectivities for the vanadyl group to the silicate building block matrix (i.e. the number of V-O-Si bonds linking the vanadyl unit). Silicate matrices containing exclusively 3-connected (OV(OSi{sub cube}){sub 3}), 2-connected (OV(OR)(OSi{sub cube}){sub 2}) or 1-connected (OVCl{sub 2}(OSi{sub cube})) vanadyl sites are described and characterized via a wide variety spectroscopic and physical techniques (gravimetric analysis, EXAFS, AA and solid state NMR ({sup 51}V, {sup 29}Si, and {sup 17}O)). We demonstrate how the combination of gravimetric, solid state NMR (SSNMR) and EXAFS data can be used to uniquely define the vanadyl sites in these matrices. Furthermore, the use of {sup 17}O SSNMR (1D and MQMAS) is illustrated as an indirect spectroscopic probe to follow changes in the ligands bound to vanadium atom within the vanadyl groups in these matrices.
The Densities of Colloidal Iron Hydroxide Particles Bound to Microvilli and the Spaces between them: Studies on Glutaraldehyde-Fixed Ehrlich Ascites Tumour Cells

The densities of positively charged, colloidal iron hydroxide particles binding to the surfaces of glutaraldehyde-fixed cultured Ehrlich ascites tumour cells, were determined on cells maintained in suspension and monolayer cultures. In both cases, there was a higher density of particles bound to the surfaces of microvilli than to the spaces between them. Prior treatment of the cells with ribonuclease did not significantly alter the proportions of particles binding to the 2 different surface regions, indicating that the ribonuclease-susceptible binding sites are distributed with similar mean densities over the microvilli and the regions between them. Prior treatment of the cells with neuraminidase reduced the densities of particles binding to microvilli to those of the intermicrovillous spaces, indicating that the original higher density over the microvilli is due to an increased number of sialic acid residues at their surfaces. The findings are discussed in relationship to observed changes in the surface density of microvilli when these cells convert from suspension to monolayer cultures.
Elucidating mechanisms of solvent toxicity in ethanologenic Escherichia coli

Ethanol toxicity and its effect on ethanol production by the recombinant ethanologenic Escherichia coli strain KO11 were investigated in batch and continuous fermentation. During batch growth, ethanol produced by KO11 reduced both the specific cell growth rate (micro) and the cell yield (Y(X/S)). The extent of inhibition increased with the production of both acetate and lactate. Subsequent accumulation of these metabolites and ethanol resulted in cessation of cell growth, redirection of metabolism to reduce ethanol production, and increased requirements for cell maintenance. These effects were found to depend on both the glycolytic flux and the flux from pyruvate to ethanol. Pyruvate decarboxylase (Pdc) and alcohol dehydrogenase (Adh) activities measured during the batch fermentation suggested that decreased ethanol production resulted from enzyme inhibition rather than down-regulation of genes in the ethanol-producing pathway. Ethanol was added in continuous fermentation to provide an ethanol concentration of either 17 or 27 g/L, triggering sustained oscillations in the cell growth rate. Cell concentrations oscillated in-phase with ethanol and acetate concentrations. The amplitude of oscillations depended on the concentration of ethanol in the fermentor. Through multiple oscillatory cycles, the yield (Y(P/S)) and concentration of ethanol decreased, while production of acetate increased. These results suggest that KO11 favorably adapted to improve growth by synthesizing more ATP though acetate production, and recycling NADH by producing more lactate and less ethanol. Implications of these results for strategies to improve ethanol production are described.
Robust clinical outcome prediction based on Bayesian analysis of transcriptional profiles and prior causal networks.

Motivation: Understanding and predicting an individual’s response in a clinical trial is the key to better treatments and cost-effective medicine. Over the coming years, more and more large-scale omics datasets will become available to characterize patients with complex and heterogeneous diseases at a molecular level. Unfortunately, genetic, phenotypical and environmental variation is much higher in a human trial population than currently modeled or measured in most animal studies. In our experience, this high variability can lead to failure of trained predictors in independent studies and undermines the credibility and utility of promising high-dimensional datasets. Methods: We propose a method that utilizes patient-level genome-wide expression data in conjunction with causal networks based on prior knowledge. Our approach determines a differential expression profile for each patient and uses a Bayesian approach to infer corresponding upstream regulators. These regulators and their corresponding posterior probabilities of activity are used in a regularized regression framework to predict response. Results: We validated our approach using two clinically relevant phenotypes, namely acute rejection in kidney transplantation and response to Infliximab in ulcerative colitis. To demonstrate pitfalls in translating trained predictors across independent trials, we analyze performance characteristics of our approach as well as alternative feature sets in the regression on two independent datasets for each phenotype. We show that the proposed approach is able to successfully incorporate causal prior knowledge to give robust performance estimates. Contact: moc.rezifp@kemeiz.leinad Supplementary information: Supplementary data are available at Bioinformatics online.
MHD duct flows under hydrodynamic “slip” condition

Three classic MHD problems are revisited assuming hydrodynamic slip condition at the interface between the electrically conducting fluid and the insulating wall: (1) Hartmann flow; (2) fully developed flow in a rectangular duct; and (3) quasi-two-dimensional (Q2D) turbulent flow. The first two problems have been solved analytically. Additionally to the Hartmann number (Ha), a new dimensionless parameter S, the ratio of the slip length to the thickness of the Hartmann layer, has been identified. One of the most important conclusions of the paper is that the duct flows with the slip still exhibit Hartmann layers, whose thickness scales as 1/Ha, while the thickness of the side layers is a function of both Ha and S. In the case of Q2D flows, a new expression for the Hartmann braking time has been derived showing its increase at Ha >> 1 by factor (1+ S). Numerical simulations performed for a flow with the “M-shaped” velocity profile show that in the presence of the slip, a Q2D flow becomes more irregular as vortical structures experience less Joule and viscous dissipation in the Hartmann layers.
Nonlinear Stress-Strain Law for Metallic Meshes

A two-dimensiona l, orthotropic, nonlinear elastic stress-strain law is proposed herein for gold-coated tricot metallic mesh material of diamond-weave pattern. This constitutive relation accommodates the geometrically nonlinear behavior due to the large displacement of the diamond-shaped cell as well as the nonlinear behavior due to its woven configuration. Comparison with experimental data showed that the proposed constitutive law provides a reasonably good description of the stress-strain behavior of this material.
Children of the Philippines: attitudes toward visible physical impairment.

Abstract Objective: This pilot study was designed to evaluate children's attitudes and understanding of physical disabilities with special reference to those with craniofacial anomalies in the Philippines. Children with and without craniofacial anomalies were studied. Design: This was a two-group correlational design with additional statistical assessment of subgroup differences. Each group was interviewed and information obtained on a standard disability preference task, attributions for playmate choice, and frequency of contact with disabilities. Parents completed a structured interview. Setting: Participants were 122 children recruited from Negros, Philippines. Participants: Fifty-four children with craniofacial anomalies (aged 7 to 12 years) were enrolled in the study, and 68 children without any disabilities were recruited from a local school in Bacolod City, Negros, Philippines. Main Outcome Measures: Participants completed a picture-ranking interview of specific physical disabilities and provided t...
Parallel computing using memristive crossbar networks: Nullifying the processor-memory bottleneck

We are quickly reaching an impasse to the number of transistors that can be squeezed onto a single chip. This has led to a scramble for new nanotechnologies and the subsequent emergence of new computing architectures capable of exploiting these nano-devices. The memristor is a promising More-than-Moore device because of its unique ability to store and manipulate data on the same device. In this paper, we propose a flexible architecture of memristive crossbar networks for computing Boolean formulas. Our design nullifies the gap between processor and memory in von Neumann architectures by using the crossbar both for the storage of data and for performing Boolean computations. We demonstrate the effectiveness of our approach on practically important computations, including parallel Boolean matrix multiplication.
From a Tight Place: Crime, Punishment, and American Liberalism

It is surely one of the ironies of President Bill Clinton's remarkable career that he will be remembered both as the leader who helped save the Democratic Party from a near fatal lack of resolve on fighting crime and as a chief victim of a governmental culture obsessed with detecting and punishing crime. Clinton's saga is only one part of the story of how a great fear of crime and a powerful passion to punish have reshaped the dynamics of American elections and, ultimately, the administration of government at the federal and state levels during the last thirty years. Signs of this transformation were present far earlier than the 1990s. In 1964, presidential candidate Barry Goldwater's acceptance speech at the Republican National Convention addressed crime in the streets and a general threat to law and order in what he labeled the permissive climate of the early 1960s.1 Goldwater lost by a landslide,2 but the victorious Democrat, Lyndon Johnson, wasted little time in appointing a national
Water treatment control using the joint estimation outlier detection method

The loss of contaminated wastewater into the environment by leakage or other means is a serious problem. This problem is essentially the same as true of the loss of chemical reagents from a chemical production or purification process. The present article shows how the joint estimation method, an outlier detection method for time series analysis, can be used by a facility manager to deal with these problems.
Arms Transfers into Militarized Interstate Disputes

This paper uses a quantitative analysis to investigate the decision-making process of the major arms suppliers, which also serves as a test of the traditional international relations paradigms. States cannot fight without arms, however, few states are capable of producing major weapons systems. Supplier states do not have an unlimited supply of arms to sell or give away as aid, thus, a strategic decision-making process is present. During MIDs, suppliers must take into account their relationship to both sides of the conflict, which can complicate the decision-making process, depending on which paradigms assumption are used to determine the relationship.
Very fast averaging of thermal properties of crystals by molecular simulation

Knowledge of approximate harmonic behavior of crystals is introduced into a new ``mapped averaging'' framework to yield alternative expressions for the thermodynamic properties of crystalline systems. The expressions separate the known harmonic behavior from residual averages, which thus encapsulate anharmonic contributions to the properties. With harmonic contributions removed, direct measurement of these anharmonic contributions by molecular simulation can be accomplished without contamination by noise produced by the already-known harmonic behavior. We show with application to the Lennard-Jones model that first-derivative properties (pressure, energy) can be obtained to a given precision via this harmonically mapped averaging at least 10 times faster than by using conventional averaging, and second-derivative properties (e.g., heat capacity) are obtained at least 100 times faster; in more favorable cases, the speedup exceeds a millionfold. Free-energy calculations are accelerated by 50 to 1000 times. Data obtained using these formulations are rigorous and not subject to any added approximation, and in fact are less sensitive to inaccuracies relating to finite-size effects, potential truncation, equilibration, and similar considerations. Moreover, the approach does not require any alteration in how sampling is performed during the simulation, so it may be used with standard Monte Carlo or molecular dynamics methods. However, the mapped averages do require evaluation of first and second derivatives of the intermolecular potential, for evaluation of first and second thermodynamic-derivative properties, respectively. Apart from its usefulness to simulation, the formalism developed here may constitute a basis for new theoretical treatments of crystals.