cssi/SciSciGPT-SciSciNet huggingface dataset:
Visualizing a nonmeasurable set

In most real analysis textbooks, the standard example of a nonmeasurable set is a subset of the real line that is due to Vitali [3]. We describe a similar nonmeasurable subset of the torus (and hence the plane), where we can more easily visualize the set. In the process of constructing the set, students get an opportunity to experience how topics they learned in algebra and topology can be used in analysis. The idea of Vitali's example is to express the unit interval I as a disjoint union of countably many mutually congruent sets Ak. The nonmeasurability of each Ak follows from the observation that I = UkEz Ak and that countable additivity of measure implies that 1 = m(I) = Lkez m(Ak). Since each set Ak must have the same measure, the last equation shows that no nonnegative value can be assigned as the measure of each Ak. We will use this same idea with the square [0, 1] x [0, 1] in the plane R2. The advantage is that we will now have a more visual object than that of Vitali's example because the example will appear as a subset of a torus.
New skeletal muscle model for the longitudinal study of alterations in microcirculation following contusion and cryotherapy

This preliminary report describes the use of a rat model developed to study in vivo the effect of anesthesia, contusion, and cryotherapy on skeletal muscle microcirculation by use of an implanted chamber. The diameters of arterioles and venules within the chamber were determined by photomicroscopy in the contusion study and by compound videomicroscopy in the anesthesia study; microvascular perfusion was determined by laser Doppler fluxmetry (LDF). Combined ketamine and xylazine anesthesia significantly reduced (P < 0.05) arteriolar and venular diameters by 32.4% and 37.8%, respectively, and average LDF measurements by 36.1%. Contusion significantly increased arteriolar diameters over baseline values (P < 0.05); cryotherapy did not alter arteriolar diameters but increased venular diameters (P < 0.05). It is hypothesized that this increase in venular diameter may, by increasing the surface area available for reabsorption, explain one mechanism by which cryotherapy decreases the edema of contusion. Use of this model should help to advance the understanding of microcirculatory dynamics following contusion and cryotherapy. © 1993 Wiley-Liss Inc.
Precision frequency measurement of the /sup 2/S/sub 1/2/-/sup 2/D/sub 5/2/ transition of Sr/sup +/ with a 674-nm diode laser locked to an ultrastable cavity

We have measured the frequency of the 5s /sup 2/S/sub 1/2/-4d /sup 2/D/sub 5/2/ clock transition of a single Sr ion confined in a Paul trap. A diode laser locked to an ultrastable Fabry-Perot (F-P) cavity was used to probe the transition with a resolution of 3.5 kHz. The absolute frequency was determined from heterodyne measurements referenced to an iodine stabilized HeNe laser and a CO/sub 2/ laser yielding a value for the S-D transition of (444 779 043 963/spl plusmn/30) kHz. This work could lead to the development of a new optical frequency standard at 674 nm.
In vitro fertilization, GIFT and related technologies--hope in a test tube.

In vitro fertilization (IVF) is demanding, expensive and inefficient. Nevertheless, tens of thousands of couples have un- dertaken the procedure because of their intense desire to have a biological child. Modifications of the current IVF process - simplifica-tion of ovulation induction and prediction of successful cycles; use of ultrasound instead of laparoscopy for egg retrieval; freezing of excess embryos for later replacement; and the substitution of GIFT (gamete intra-fallopian transfer) for IVF when it is indicated - may increase its acceptability to couples and improve success rates. Meanwhile, IVF has had tremendous impact on our understanding of fertility and should help physicians in their approach to infertility in the future. It has also ushered in a new era of genetic engineering whose potential we have not yet begun to realize.
Iconic memory of dot patterns: preliminary report.

Pairs of complementary dot-pattern stimuli whereby each stimulus pair forms a bigram were used in an iconic memory paradigm. The variables of stimulus dutation, interstimulus interval, dot density,...
Absorption spectrum of the peptide bond: Basic properties of peptides and proteins

Abstract The basicity of a series of peptides and proteins has been determined in the sulfuric acid system and in acetic acid. The values of pKa all fall in a narrow range of values. The relation between these findings and the theory of energy transfer by peptide bonds is considered.
Cytogenetic analysis of thyroid tumors after cryopreservation

Current cytogenetic evaluation of solid tumors is performed on fresh tissue specimens requiring on-call tissue culture facilities. The application of cryopreservation to tumor samples prior to cytogenetic analysis allows collection of tumors to a desired sample size. We evaluated methods of cryopreservation for their effects on growth potential from 11 benign thyroids and one papillary thyroid cancer. Mitotic indices and thyroglobulin expression applying imunocytology were analyzed. Compared to fresh tumors, the revived tumor samples showed unaltered thyroglobulin expression. A statistically significant (p < 0.004) prolongation to develop mitotic activity occurred in samples received after the freezing of dispase digested tissues, but not in samples frozen as thinly cut pieces. In addition, the data show that cytogenetic analysis at the 400-band level can be achieved in cryopreserved thyroid tissues.
Sedimentary Phosphorites-An Example: Phosphoria Formation, Southeastern Idaho, U.S.A.

The phosphorous cycle filters through both the biological and geological worlds, and sedimentary phosphates exist at the interface between these two portions of the global phosphorous cycle. Sedimentary phosphates form only when the proper physical conditions and biological activity coincide. Once deposited, the phosphate (PO43−) crystallizes into the mineral carbonate-fluorapatite (CFA). This mineral, with substitution of CO32− for PO43−, compositionally falls between the familiar forms of fluorapatite found in igneous and metamorphic rocks and the apatites found in biological material, including our own bones and teeth. Finally, through mining and processing, it is these sedimentary phosphates that are used as fertilizers and additives for food production and other activities and are subsequently returned to the biosphere. The unique settings in which phosphorites form, those areas where phosphate is concentrated millions of times above normal and sedimentation rates are drastically slowed, are not fully understood, and have been the subject of sometimes intense scientific debate over the last century and a half. Furthermore, the mineralogy of these deposits is unique, difficult to study, and contentious. Because of our dependence on phosphate for use in fertilizers and other agricultural and chemical uses, these deposits are interesting not only from a scientific viewpoint but from an economic standpoint as well. However, like many mining operations, phosphate mining has environmental problems that must be addressed. This chapter provides an overview of the salient points in phosphorite formation, mineralogy, and mining and puts into context the current work being undertaken on the Phosphoria Formation in southeastern Idaho. This chapter does not provide a full description of all the sedimentalogical, mineralogical, and industrial work that has been done on sedimentary phosphates; indeed numerous full volumes have been published on phosphorites and more will undoubtedly follow. For large-scale phosphorites to …
Reactions between Hot‐Pressed Calcium Hexaluminate and Silicon Carbide in the Presence of Oxygen

The reactions between hot-pressed calcium hexaluminate (CaAl12O19, hibonite) and silicon carbide (SiC) at 1100°-1400°C in air and nominal argon atmospheres were investigated. In inert atmospheres, there was no evidence of reaction at temperatures up to at least 1400°C. In air, the oxidation of SiC produced a layer of silica or a multicomponent amorphous silicate (depending on impurities) that reacted with CaAl12O19. At temperatures below 1300°C, the reaction resulted in the stratification of two distinct interfacial layers: a partially devitrified CaO-Al2O3-SiO2 glass adjacent to SiC and a CaAl2Si2O8 (anorthite) layer adjacent to hibonite. At 1400°C, a large amount of liquid was formed, the majority of which was squeezed out from between the reaction couple. No distinct layer of anorthite was present; instead, the anorthite was replaced by a layer of alumina between the glass-rich layer and hibonite. An activation energy of 290 kJ/mol was determined for the reaction, which is consistant with oxygen diffusion through a calcium aluminosilicate glass. The reaction between rare-earth hexaluminates and SiO2 was predicted to produce a more-viscous glass than CaAl12O19 and SiO2 and, therefore, have slower reaction kinetics, because of lower mass transport in the glass.
The role of impurities in bubble formation during directed light processing of tantalum

The utility of directed-light fabrication (DLF) as a method for the manufacture of refractory metal parts has been hampered by the formation of bubbles in the finished product. This study examines the connection between these bubbles and impurities found in several Ta feedstock powders. Bulk and surface impurities associated with the powders were determined using glow-discharge mass spectroscopy (GDMS), thermal desorption and X-ray photoelectron spectroscopy (XPS). A cylindrical part with a high bubble density was fabricated from the Ta powder using DLF and was subsequently fractured in vacuum. The exposed bubble surfaces were examined with Auger electron spectroscopy (AES) and secondary electron microscopy (SEM). Unlike the surrounding region, the bubble surfaces were coated with a K-rich layer. Potassium was an impurity found in the feedstock powder by GDMS. Due to incompletely understood process dynamics, a simple equilibrium model was used to examine the likelihood that gaseous K was trapped in the molten Ta to produce the bubble growth. The results suggest that another impurity, such as hydrogen, may have a primary role in the bubble formation. Analysis of recycled powder that had not been fused during DLF processing showed a decreased concentration of K, Na, F, H and water impurities, implying that some high-temperature purification of the feedstock powder might improve the quality of parts fabricated in this manner.
The orders of documents, the orders of activity, and the orders of information

The invention of literacy was also the invention of written information. Humanly usable information has been (and will likely continue to be for the foreseeable future) tied to human documents. Any order we impose on or find in information is closely tied to human uses that give rise to it or for which it is repurposed, and those orders are expressed in the documentary genres that mediate human communicative action within social activity systems. These social forms of genres and activity systems shape our consciousnesses, cognitive capacities, social identities, and potentials for action. Making sense of a single claim, sentence, or even datum requires an understanding of what kind of text it appears in, engaged in what sort of inquiry using what methods, and where it stands within the evolving intertextual discussion of the field. Sense making requires integrity of the text and visibility of the provenance and socio-historic dynamic from which it arises. Even as the processes of communication have been less tied to immediate social circumstances, they have fostered new kinds of social relations and communicative circumstances that maintain their social character and functionality. As we convert older technologies of information storage based on the physical texts, to digital technologies that can readily draw together heterogeneous pieces from more heterogeneous circumstances, the user ultimately must make sense of the information, and the technologies will need to find ways to support that sense making.
Structural characterization of nanoporous Pd films grown via ballistic deposition

Abstract Nanoporous Pd films were vapor-deposited onto an oxidized Mo(1 0 0) substrate at 22 K and various dosing angles. Temperature programmed desorption (TPD) of N 2 was used to determine the surface area of the Pd films immediately after deposition at 22 K, and following annealing. The surface area of Pd films was found to depend dramatically on the Pd dosing angle and annealing temperature. Pd films grown at 22 K with a 85° deposition angle exhibit the highest surface area of 120 m 2 /g. Ex situ SEM imaging reveals that these films consist of a tilted array of nanocrystalline filaments. The annealing studies show that the films densify upon annealing and lose approximately 50% of their surface area by 300 K and are almost completely dense by 500 K. Pd deposition at elevated temperatures (
Natural convection flow of a nanofluid over a vertical plate with uniform surface heat flux

Natural convective flow of a nanofluid over a vertical plate with a constant surface heat flux is investigated numerically, following a similarity analysis of the transport equations. The transport model employed includes the effect of Brownian motion and thermophoresis. The analysis shows that velocity, temperature and concentration profiles in the respective boundary layers depend, besides the Prandtl and Lewis numbers, on three additional dimensionless parameters, namely a Brownian motion parameter Nb, a thermophoresis parameter Nt, a buoyancy ratio parameter Nr. In addition to the study of these parameters on the boundary layer flow characteristics (velocity, temperature, nanoparticle concentration, skin friction, and heat transfer), correlations for the Nusselt and Sherwood numbers have been developed based on a regression analysis of the data. These correlations predict the numerical results with a maximum error of 5.5% for the reduced Nusselt number and 3.2% for the reduced Sherwood number.
Progestin Content of Ovaries and the Effect on Assessment of Luteal Activity in the Bovine

Abstract Samples of ovarian venous blood and ovaries collected by laparotomy from 114 animals following estrus and breeding, during pregnancy and post-partum, were assayed for the progestins, progesterone and 20 β -hydroxy-Δ 4 -pregnene-3-one (20 β -ol). The objective was to determine if progestin content of the corpus luteum (CL) adequately reflected the progestin content of both ovaries. Progestins in ovaries and CL were measured spectrophotometrically, and progesterone in jugular venous plasma was measured by double isotope derivative reaction. Ovarian venous plasma progesterone was measured by both methods. The CL contained 94% of the total progestin in 100 ovaries, bearing a CL of which 80% was progesterone and 14% was 20 β -ol. The CL content averaged 214±9.5 µ g of progesterone and 38.4±3.2 of 20 β -ol. Progesterone and 20 β -ol in the residual ovary were not correlated ( r = 0.11). The part-whole linear correlations comparing the progestins in CL with total in the ovary ranged from 0.96 to 0.99 for CL content and 0.81 to 0.87 for CL concentrations. The progestins in ovaries without a CL were low and often not detectable and content was not significantly correlated with progestin in the ovary containing a CL (19 pairs of ovaries). Progesterone concentration in the ovarian venous plasma from the CL-bearing ovary was four times higher as compared to plasma from the opposite ovary (P
Coherent-mode propagation in spatially band-limited wave fields

Some new results are established regarding a recently developed coherent-mode representation of steady-state sources and fields of any state of coherence. It is shown that when a planar source is spatially band limited in the sense that its cross-spectral density function contains only spatial frequencies smaller than the corresponding wave number, the mode representation has some very simple and useful properties. Some potential applications of the results are mentioned.
Experimentally Determined Evaporation Rates in Pervious Concrete Systems

AbstractAs the use of pervious concrete pavements increases, evaporation of storm water retained in the pervious concrete system becomes an important design parameter. This paper extends the knowle...
Chloroplast DNA reassociation and grass phylogeny

Sequence variation in chloroplast DNA (cpDNA) as measured by DNA reassociation was examined in 12 grass species to address systematic problems in thePoaceae at the subfamilial and tribal levels. Two species,Petunia (Solanaceae) andGlycine (Leguminosae), were included to determine degrees of sequence divergence in cpDNA between monocots and dicots. The data were analyzed phenetically and phylogenetically. Species were segregated into four major groups that corresponded to the subfamiliesPooideae, Oryzoideae, Chloridoideae, andPanicoideae. Representatives of thePooideae andOryzoideae grouped together as did members of theChloridoideae andPanicoideae. ThePooideae split into two major groups corresponding to the recently recognized supertribesTriticanae andPoanae. Internodes between subfamily branches were short which might indicate a burst of divergence in the family early in its evolution. Sequence similarity values between the monocot grass species and the two dicot taxa ranged from 0.15 to 0.27, representing the highly conserved sequences of the chloroplast genome.
Aldosterone esters and the heart.

There are clinical and experimental situations in which symptoms of mineralocorticoid excess are remediable with mineralocorticoid receptor antagonist treatment, in spite of paradoxically low levels of plasma renin and aldosterone. Several decades ago, a factor isolated from the heart was described that had mineralocorticoid properties like those of aldosterone, but much more potent. It was thought to be similar to aldosterone-18-monoacetate or -21-monoacetate, acetyl derivatives of aldosterone that are very rapidly hydrolyzed in the circulation. In our efforts to confirm and extend these observations, we extracted rat hearts and plasma harvested in a manner that would minimize hydrolysis. The product was subjected to several forms of TLC and HPLC and compared to several acetylated derivatives of aldosterone standards. We found that 68% of the aldosterone extracted from fresh myocardium corresponded to an aldosterone derivative that migrates at the same rate as aldosterone-20-monoacetate. The identity of this compound awaits definitive analysis. Tritiated aldosterone-21-monoacetate hydrolyzed to form aldosterone very rapidly; negligible monoacetate remained in blood left at 37°C for 5 min or in hearts left at room temperature for 30 min. Regulation of aldosterone production serves the requirements of fluid and electrolyte homeostasis provided by transport epithelia, primarily that of the kidney. Nonepithelial actions of aldosterone would be freed of these regulatory constraints if the formation of a more potent derivative of the parent compound to which it is almost immediately hydrolyzed in the circulation were regulated within the nonepithelial target tissues.
TiC growth in C fiber/Ti alloy composites during liquid infiltration

A cylindrical model is developed for predicting the reaction zone thickness of carbon fiber-reinforced Ti-matrix composites, and good agreement is obtained between its predicted values and experimental results. The reaction-rate constant for TiC formation is estimated to be 1.5 x 10 exp -9 sq cm/sec. The model is extended to evaluate the relationship between C-coating thicknesses on SiC fibers and processing times.
Molecular-dynamics approach to lattice-relaxation effects on deep levels in semiconductors

Une dynamique moleculaire est utilisee pour calculer la relaxation de reseau autour d'une impurete. Ses effets sur les niveaux profonds associes sont simules a l'aide d'une methode de fonction de Green. Exemples avec des impuretes dans GaP et Si
Electronic micrometer system for precise recording of coordinates from ultracentrifuge plates

Abstract The reading of position coordinates from ultracentrifuge schlieren and interference plates is greatly facilitated by the use of a zero-backlash transducer that can be attached to a standard microcomparator stage. On command from the operator, an electronic system controls the operation of a Flexowriter which prints and punches paper tape records of micrometer positions to the nearest 1 μ for all points selected throughout the full range of micrometer movements. The combination of human control with automatic recording of digital data by a mechanically simple system is believed to utilize the capabilities of man and machine to best advantage in performing the measuring tasks of an ultracentrifuge laboratory.
Plasticity of Adult Stem Cells

Recent years have seen much excitement over the possibility that adult mammalian stem cells may be capable of differentiating across tissue lineage boundaries, and as such may represent novel, accessible, and very versatile effectors of therapeutic tissue regeneration. Yet studies proposing such "plasticity" of adult somatic stem cells remain controversial, and in general, existing evidence suggests that in vivo such unexpected transformations are exceedingly rare and in some cases can be accounted for by equally unexpected alternative explanations.
Modulation of integrin antagonist signaling by ligand binding of the heparin binding domain of vitronectin to the αVβ3 integrin

The interaction between the arginine glycine and aspartic acid motif (RGD) of integrin ligands such as vitronectin and the integrin receptor αVβ3 in mediating cell attachment has been well described. Similarly, the ability of disintegrins, small RGD containing peptides, to inhibit cell attachment and other cellular processes has also been studied extensively. Recently, we characterized a second site of interaction between vitronectin and its integrin partner. We determined that amino acids within the heparin-binding domain of vitronectin bind to a cysteine loop (C-loop) region of β3 and that this interaction is required for the positive effects of αVβ3 ligand occupancy on IGF-I signaling in smooth muscle cells. In this study we examine the signaling events activated following ligand binding of disintegrins to the αVβ3 and the ability of these signals to be regulated by binding of the heparin-binding domain of vitronectin. We demonstrate that disintegrin ligand binding activates a series of events including the sequential activation of the tyrosine kinases c-Src and Syk. This leads to the activation of calpain and the cleavage of the β3 cytoplasmic tail. Addition of vitronectin or a peptide homologous to the heparin-binding domain inhibited activation of this pathway. Our results suggest that the signaling events that occur following ligand binding to the αVβ3 integrin reflects a balance between the effects mediated through the RGD binding site interaction and the effects mediated by the heparin binding site interaction and that for intact vitronectin the effect of the heparin-binding domain predominates. J. Cell. Biochem. 105: 437–446, 2008. © 2008 Wiley-Liss, Inc.
Toward an Enhanced Understanding of the Psychological Mechanisms by which Spirituality Aids Recovery in Alcoholics Anonymous

Alcoholics Anonymous (AA) is based on a spiritual program of action. In keeping with AA's spiritually based recovery theory, rigorous studies have revealed that spirituality may be one of the mechanisms through which AA aids recovery. A question that has lingered, however, is how exactly does an increase in spiritual beliefs and practices translate into more abstinence and remission? To help answer this question, this article reviews theory and research related to AA and spirituality as a mechanism of behavior change and offers five possible psychological pathways that may help explain how increases in spirituality may translate into enhanced abstinence and remission rates.
Redox response model for partly substituted cuprates

Abstract Inhomogeneous substitutions (e.g. clustering and preferential site occupations) in compounds such as YBa 2 (Cu 1−x M x ) 3 O y with M = Fe, Co, Ni, etc. are an unavoidable response to the changing redox environments in these O intercalation compounds. We collect here experimental evidence for various types of inhomogeneous distributions predicted on a thermodynamic model which considers the preferential “desorption” of O from various local environments. The parameter organizing the redox environment is ΔH∗ (incremental enthalpy of oxygen desorption per mol O 2 ). Theory suggests a sequence of discernible states represented by the acronym CLUSTER. With decreasing ΔH∗, indications for several of these states are obtained from Mossbauer and other experiments. These states are characteristically shifted in ΔH∗ for different M. Also, further substitutions according to (YX)(BaZ) 2 (CuM) 3 O y with X = Ca, Z = Sr, La can change the relevant ΔH∗ for these states, allowing prediction of their preparation conditions. Aspects of the complex electronic phase diagram as a function of redox preparation are discussed.
A class of deformational flow test cases for linear transport problems on the sphere

A class of new benchmark deformational flow test cases for the two-dimensional horizontal linear transport problems on the sphere is proposed. The scalar field follows complex trajectories and undergoes severe deformation during the simulation; however, the flow reverses its course at half-time and the scalar field returns to its initial position and shape. This process makes the exact solution available at the end of the simulation, and facilitates assessment of the accuracy of the underlying transport scheme. A procedure to eliminate possible cancellations of errors when the flow reverses is proposed. The test suite consists of four cases. Three are based on non-divergent flow fields and one on a divergent flow. The initial conditions are prescribed in terms of regular latitude-longitude spherical coordinates and are easy to implement. The divergent flow is specifically aimed for conservative global transport schemes to test for conservation, consistency and monotonicity (or positivity) of limiters/filters in a challenging flow environment. In the context of semi-Lagrangian schemes, the time-varying flow fields can be used to test trajectory algorithms where the exact trajectories do not follow great-circle arcs. The characteristics of the test cases are demonstrated with two different transport schemes.
In Silico Models of Aerosol Delivery to the Respiratory Tract – Development and Applications

This review discusses the application of computational models to simulate the transport and deposition of inhaled pharmaceutical aerosols from the site of particle or droplet formation to deposition within the respiratory tract. Traditional one-dimensional (1-D) whole-lung models are discussed briefly followed by a more in-depth review of three-dimensional (3-D) computational fluid dynamics (CFD) simulations. The review of CFD models is organized into sections covering transport and deposition within the inhaler device, the extrathoracic (oral and nasal) region, conducting airways, and alveolar space. For each section, a general review of significant contributions and advancements in the area of simulating pharmaceutical aerosols is provided followed by a more in-depth application or case study that highlights the challenges, utility, and benefits of in silico models. Specific applications presented include the optimization of an existing spray inhaler, development of charge-targeted delivery, specification of conditions for optimal nasal delivery, analysis of a new condensational delivery approach, and an evaluation of targeted delivery using magnetic aerosols. The review concludes with recommendations on the need for more refined model validations, use of a concurrent experimental and CFD approach for developing aerosol delivery systems, and development of a stochastic individual path (SIP) model of aerosol transport and deposition throughout the respiratory tract.
Radiation induction of immediate early genes: Effectors of the radiation-stress response

Recent studies have demonstrated that the early response genes c-jun, Egr-1, c-fos, and NF kappa B are induced following exposure of mammalian cells to ionizing radiation. We propose that the products of these early response genes regulate downstream genes that are important in the adaptation of cells and tissues to radiation-induced stress. Potential downstream targets include cytokine and growth factor genes as well as deoxyribonucleic acid (DNA) repair genes. Early response gene products may also regulate cell cycle progression following cellular x-irradiation. Signal transduction pathways that allow cells to adapt to radiation may provide molecular targets to modify tumor and normal responses to radiotherapy.
Serous cystadenoma of the pancreas: clinical and pathological features in 33 patients.

Aim: To report the clinicopathological features of patients with serous cystadenomas of the pancreas. Methods: Thirty-three cases of serous cystadenoma diagnosed
Formative Research on the Heuristic Task Analysis Process

Corporate and educational settings increasingly address more decision-making, problem-solving and other complex cognitive skills to handle complex cognitive, or heuristic, tasks, but the ever-increasing need for heuristic knowledge has outpaced the refinement of task analysis methods for heuristic expertise. Utilizing the Heuristic Task Analysis (HTA) process, a method developed for eliciting, analyzing, and representing expertise in complex cognitive tasks, a formative research study was conducted on the task of group counseling to further improve the HTA process. Implications of the findings include the need for incorporating various interview strategies and techniques, developing strategies for working with multiple experts, and considering the level of task expertise of the analyst. A revised version of the HTA process is presented based on these implications.
Pseudo-isotopy and invariant theory—I

such that f(M X 0 = id; the space of all such pseudo-isotopies (with the C” Whitney topology) is denoted P(M). This paper looks at the problem of computing the rational homotopy groups qP( M>@0 for i G dim M, under the assumption that M is simpiyconnected. These homotopy groups are very closely related to corresponding rational homotopy groups of the space of diffeomorphisms of M [ l-41. According to [ 1,3] there is a natural suspension map
Oxygen gradients for open well cellular cultures via microfluidic substrates

Controlling oxygen concentration at a microscale level can benefit experimental investigations involving oxidative stress, ischemia, and reactive oxygen species (ROS) mediated cellular pathways. Here, we report the application of microfluidic gradient generation in an open-well culture model, in which a gradient of gas is delivered via diffusion through a gas permeable substrate that separates cells from the gas microchannels below. By using diffusion to localize oxygen delivery, microgradients of oxygen concentrations can be rapidly and controllably applied without exposing cells to mechanical stresses or reducing culture volumes inside microfluidic culture chambers. Furthermore, we demonstrate the modulation of intracellular ROS levels in Madin–Darby Canine Kidney (MDCK) cells by applying these oxygen microgradients. Increases in ROS levels consistent with both oxidative stress and hypoxic exposures were observed in MDCK cells. The measured ROS increases were comparable to 100 µM hydrogen peroxide exposure in a control comparison, which is within the range of standard ROS induction methods. Incubation with 200 µM vitamin C was able to demodulate the ROS response at both hypoxic and hyperoxic exposures. By providing microfluidic controlled gradients, constant ROS exposure, and a shear-free open well design, the devices introduced here greatly improve upon standard oxygen-based culturing methods.
The duration inventory: Subjective extensions of temporal zones

Abstract Perceptions of the duration of the present, distant and near past, and distant and near future are measured with a Duration Inventory. Interrelationships among these perceived durations are examined along with an empirical demonstration of asymmetric present perceptions. The discussion includes variations in the perceptions of the temporal horizon, and particularly the sense of a continuity of its various sectors. A distinction is made finally, between subjective and objective evaluations of time zones.
A new variant of a vehicle routing problem: Lower and upper bounds

Abstract This paper deals with a combinatorial optimization problem that arises in the design of a semi-automatic system for cutting leather skins called the laser multi-scanner problem (LMSP). The problem occurs in the first part of the cutting process: the parts to be cut are placed on the cutting board by using a new technique, the so-called `lasernest'; the outlines of the pieces are projected onto the board by several laser rays. The optimization goal is to assign the pieces to the laser rays such that the maximum length of a laser route is minimal. This can be modelled as a new variant of a vehicle routing problem. Due to severe time restrictions we are only interested in fast heuristic solutions. We construct feasible solutions by opening heuristics, namely, insertion algorithms and greedy variants. In a second step we improve the solutions using local search based on arc exchanges. We evaluate the quality of solutions by lower bounds which are derived from combinatorial and LP-relaxations. Thereby, we examine directed Q -forests on a multi-digraph which have matroid structure. Finally, we present some computational results on real-world data.
A self-optimizing single-step algorithm for the numerical integration of parabolic equations

Abstract An unconditionally stable single step time marching algorithm for parabolic equations is presented. In this algorithm, time stepping parameters are chosen according to an error condition such that large time step accuracy is achieved, and the solution is also free from oscillations. It is different from conventional algorithms, such as the Crank-Nicolson scheme, in that it uses a matrix of time stepping parameters rather than a single scalar value. These parameters can be approximated inexpensively. This algorithm is easily programmed and comparisons are made with other methods for different cases of a heat conduction problem. It is found that the algorithm gives a more accurate solution for all degrees-of-freedom for the cases considered. It is therefore advantageous over the conventional variably weighted Euler θ-method which has a constraint that the same θ value must be used for all degrees-of-freedom and that θ values have to be changed by trial and error for different time step sizes and mesh refinements in order to achieve best results.
Role of TiB2 and Bi2O3 additives on the rechargeability of MnO2 in alkaline cells

Abstract With an aim to understand the role of recently reported Ti-containing additives like TiB 2 on the rechargeability of manganese oxide cathodes in alkaline cells, a redox reaction involving the chemical oxidation of Mn(OH) 2 with H 2 O 2 in KOH solution and a non-redox reaction involving the reaction of Mn(III) acetate with KOH have been carried out in the presence and absence of 1 wt% TiB 2 and 0.5 wt% TiB 2 + 4.5 wt% Bi 2 O 3 additives. The solid products formed during the reactions have been analyzed by X-ray diffraction and a redox titration to determine the oxidation state of manganese while the filtrate has been analyzed to determine the amount of dissolved manganese with reaction time. The results suggest that irreversible reactions that follow the disproportionation reaction of dissolved Mn 3+ , which leads to the formation of electrochemically inactive phases like birnessite (δ-MnO 2 ) and hausmannite (Mn 3 O 4 ) and a consequent decline in capacity retention, are suppressed in the presence of the TiB 2 additive, with the suppression being more effective when Bi 2 O 3 is present along with TiB 2 .
A Quantum Chemical Study of the C-C Bond Fission Pathways of Alkoxy Radicals Formed following OH Addition to Isoprene

Isoprene is one of the most important non-methane organic compounds in tropospheric chemistry, yet its atmospheric degradation pathways remain incompletely understood. The uncertain fates of alkoxy radicals formed in the first stages of the OH-initiated degradation of isoprene contribute significantly to our ignorance. This paper examines the C−C bond fission pathways of these radicals at the B3LYP/6-311G(2df,2p) level of theory. For the four β-hydroxyalkoxy radicals that are expected to be formed, C−C bond fission (decomposition) pathways exist with very low barriers (0.7−2.1 kcal/mol) that are likely to dominate the chemistry. These radicals appear to possess intramolecular hydrogen bonds which typically persist in the transition states. For the two δ-hydroxyalkoxy radicals formed, C−C bond fission is endothermic (16−20 kcal/mol) and this pathway is unlikely to be important.
Anomalous gate dependence of the Kondo effect in single-molecule transistors

In semiconductor quantum dots, the Kondo temperature has been observed to depend exponentially on the gate voltage. This dependence arises because in these structures the gate capacitively shifts the energy of the singly occupied Kondo-active level relative to the chemical potential of the conduction electrons in the source and drain. In single-molecule transistors incorporating transition metal complexes, we find that the expected gate dependence in the Kondo regime is not observed. While the data show that the gate does shift electronic levels, the Kondo temperature found from both the differential conductance temperature and bias voltage dependence is approximately independent of gate voltage. We discuss possible explanations for this surprising observation, including the possible effect of molecular vibrational modes.
Mass transfer during ice particle collisions in planetary rings

Experimental results are presented from laboratory environment simulations of the ice particle collisional properties defining the structure and dynamical evolution of planetary rings. It is inferred from these data that there is a dependence of the interacting volume on the impact velocity. Although the volume fraction exchanged during a collision is small, the net amount of material transferred can be substantially smaller. Attention is given to the implications of these determinations for planetary ring structure and evolution.
Nuclear magnetic resonance blood flow measurements in the human brain

Timed sequences of nuclear magnetic resonance imaging signals in the human head were used to quantitatively measure blood flow in the internal jugular veins. The procedure can be straightforwardly applied to any vein or artery in the body.
Membrane insertion kinetics of a protein domain in vivo. The bacterioopsin n terminus inserts co-translationally.

The pathway by which segments of a polytopic membrane protein are inserted into the membrane has not been resolvedin vivo. We have developed an in vivo kinetic assay to examine the insertion pathway of the polytopic protein bacterioopsin, the apoprotein of Halobacterium salinarumbacteriorhodopsin. Strains were constructed that express the bacteriorhodopsin mutants I4C:H6 and T5C:H6, which carry a unique Cys in the N-terminal extracellular domain and a polyhistidine tag at the C terminus. Translocation of the N-terminal domain was detected using a membrane-impermeant gel shift reagent to derivatize the Cys residue of nascent radiolabeled molecules. Derivatization was assessed by gel electrophoresis of the fully elongated radiolabeled population. The time required to translocate and fully derivatize the Cys residues of I4C:H6 and T5C:H6 is 46 ± 9 and 61 ± 6 s, respectively. This is significantly shorter than the elongation times of the proteins, which are 114 ± 26 and 169 ± 16 s, respectively. These results establish that translocation of the bacterioopsin N terminus and insertion of the first transmembrane segment occur co-translationally and confirm the use of the assay to monitor the kinetics of polytopic membrane protein insertion in vivo.
Magnetostatic interactions between sub-micrometer patterned magnetic elements

We have investigated the effect of the magnetostatic interaction field between submicrometer patterned magnetic elements in arrays (/spl sim/10/sup 8/ elements) using Alternating Gradient Force Magnetometry. Single layer NiFe elements were studied over a range of width (0.12 to 0.48 /spl mu/m), length to width aspect ratio (1.5 to 4) and thickness (30 /spl Aring/ to 60 /spl Aring/). The arrays were patterned using e-beam lithography in a rectangular lattice with bit separation equal to element width. Effective interaction fields were obtained using a novel application of /spl Delta/M plots to these patterned arrays. The /spl Delta/M plot is derived by subtracting remanent magnetization curves that had initial states of full magnetization from those that were initially demagnetized. Interaction fields were quantified using H/sub int/=/spl Delta/M//spl chi//sub irr/, where /spl Delta/M is the difference in these remanent loops and /spl chi//sub irr/ is the derivative of the remanent magnetization with respect to field. We found H/sub int/ to increase with element aspect ratio, thickness and inverse width. For structures with the largest aspect ratio, thickness and smallest width, H/sub int//spl ap/6 Oe. We calculated the actual dipolar interaction fields using micromagnetic simulation and used these fields in a simple 2-d Ising model to simulate the experiment. We found H/sub int/ that is a good measure of the difference in interaction fields tending to magnetize or demagnetize the sample.
Benchmarking the Accuracy of Inertial Measurement Units for Estimating Joint Reactions

Newly developed miniature wireless inertial measurement units (IMUs) hold great promise for measuring and analyzing multibody system dynamics. This relatively inexpensive technology enables non-invasive motion tracking in broad applications, including human motion analysis. The second part of this two-part paper advances the use of an array of IMUs to estimate the joint reactions (forces and moments) in multibody systems via inverse dynamic modeling. In particular, this paper reports a benchmark experiment on a double-pendulum that reveals the accuracy of IMU-informed estimates of joint reactions. The estimated reactions are compared to those measured by high precision miniature (6 dof) load cells. Results from ten trials demonstrate that IMU-informed estimates of the three dimensional reaction forces remain within 5.0% RMS of the load cell measurements and with correlation coefficients greater than 0.95 on average. Similarly, the IMU-informed estimates of the three dimensional reaction moments remain within 5.9% RMS of the load cell measurements and with correlation coefficients greater than 0.88 on average. The sensitivity of these estimates to mass center location is discussed. Looking ahead, this benchmarking study supports the promising and broad use of this technology for estimating joint reactions in human motion applications.Copyright © 2013 by ASME
"Biochemists and molecular biologists: laboratories, networks, disciplines": comments.

La multiplicite des perspectives et methodologies qui refletent les differents aspects de l'histoire complexe de la biologie moleculaire montre que la biochimie a joue un role fondamental dans le developpement de la biologie moleculaire
Multiple Scattering of Elastic Waves by Parallel Cylinders

The formal solution resulting from the scattering of a plane, time-harmonic, compressional elastic wave impinged on a group of parallel circular cylindrical inclusions in a finite domain is obtained. The inclusions are rigid as well as immovable and the geometry of their configuration is arbitrary. The technique of “multiple scattering” which was developed in acoustic and electromagnetic wave propagation is applied. The stress field around two identical circular cylindrical inclusions at a finite separation is studied in detail.
Customer-focused service management for contact centers

Customer-focused service management results when contact center metrics are based on the customer's expectations. Today, contact centers are a primary touch point between a customer and an enterprise. We identify customer communications, business intelligence, service improvement, and business impact as the four main components of service management. Using real life examples, we show that the voice of the customer is the main driving force for each of these components.
Evidence for the adaptive significance of allozymes in forest trees

Positive correlations between allozyme heterozygosity and fitness measures, primarily growth and fecundity, have been reported for a number of forest tree species. Because the amount of variation in growth explained by allozyme genotype is usually on the order of only a few percent, there has been little effort made towards using electrophoretic screening of allozymes as a tool in early selection on seedlings in production nurseries. We review the progress made in studies of heterozygosity in forest trees, focusing on how recent studies have utilized careful experimental design to allow testing of hypotheses as to the causative nature of the heterozygosity-fitness phenomena. We discuss evidence suggesting a deleterious nature for rare allozyme alleles, and present a case of apparent balancing selection across life history stages acting to maintain rare alleles in Pinus taeda. We also review the apparently common trend in natural stands toward increasing heterozygosity over time, and suggest how gains might be made through artificial selection based on allozyme survey data.
A QM/MM model for O( 3 P) reaction with an alkyl thiolate self-assembled monolayer

Abstract A QM/MM potential energy surface model is developed for the reaction of O( 3 P) with a self-assembled monolayer (SAM) of alkyl thiolate chains on Au{111}. The QM part of the model consists of O( 3 P) and CH 3 –(CH 2 ) n – surface moieties of a group of the SAM's central alkyl thiolate chains. A model for this QM part is developed by refitting the PM3 semiempirical electronic structure theory to specific reaction parameters (SRPs). In this model, the CH 3 –CH 2 – group represents the surface moieties and experimental and high-level ab initio data for the O( 3 P)+C 2 H 6 →OH+C 2 H 5 reaction are used to fit the SRPs. The resulting QM/MM potential energy surface is used in an initial trajectory simulation of O( 3 P) reaction with the n -hexyl thiolate SAM/Au{111} surface as a function of incident energy and azimuthal angle. The trajectories are restricted to the triplet potential energy surface. The results of this preliminary and incomplete trajectory study are compared with a related recent experimental study of O( 3 P) with liquid squalane (D.J. Garton, T.K. Minton, M. Alagia, N. Balucani, P. Casavecchio, G.G. Volpi, Faraday Discuss. 108 (1997) 387). A complete trajectory study of the O( 3 P)+ n -hexyl thiolate SAM reaction dynamics, based on this QM/MM model, will be reported later.