cssi/SciSciGPT-SciSciNet huggingface dataset:
Kernel-Based Constrained Energy Minimization for Hyperspectral Mixed Pixel Classification

One fundamental task of hyperspectral imaging is spectral unmixing. In this case, the conventional pure pixel-based hyperspectral image classification (HSIC) may not work effectively for mixed pixels. This article presents a kernel-based approach to hyperspectral mixed pixel classification (HMPC) which includes two nonlinear mixed pixel classifiers, kernel constrained energy minimization (KCEM) and kernel linearly constrained minimum variance (KLCMV) to replace the widely used pure pixel-based support vector machine (SVM) classifier. Interestingly, what the binary-class and multiclass SVM classifiers are to pure pixel-based HSIC can be similarly derived for what a single-class KCEM detector and a multiclass KLCMV detector are to HMPC. In particular, the commonly used discrete classification map-based hard classification measures, average accuracy (AA) and overall accuracy (OA) for performance evaluation can be further generalized to real-valued mixed class abundance fractional map-based soft classification measures via 3-D receiver operating characteristic (3-D ROC) analysis-derived detection measures. Extensive experiments are conducted to demonstrate the utility of HMPC where KCEM/KLCMV not only significantly improve the classification performance of CEM/LCMV-based classifiers but also outperform many existing spectral-spatial classification methods.
Annotating modernism: marginalia and pedagogy from Virginia Woolf to the confessional poets

Annotating Modernism: Marginalia and Pedagogy from Virginia Woolf to the Confessional Poets by Amanda Golden contributes to modernist studies by investigating how contemporary poet-teachers engaged...
A Systematic Investigation of Commonsense Understanding in Large Language Models.

Large language models have shown impressive performance on many natural language processing (NLP) tasks in a zero-shot setting. We ask whether these models exhibit commonsense understanding -- a critical component of NLP applications -- by evaluating models against four commonsense benchmarks. We find that the impressive zero-shot performance of large language models is mostly due to existence of dataset bias in our benchmarks. We also show that the zero-shot performance is sensitive to the choice of hyper-parameters and similarity of the benchmark to the pre-training datasets. Moreover, we did not observe substantial improvements when evaluating models in a few-shot setting. Finally, in contrast to previous work, we find that leveraging explicit commonsense knowledge does not yield substantial improvement.
Growth of the Normal Human Heart

During fetal development, the majority of organogenesis is completed during the first trimester of pregnancy. The heart is the first organ to form and the process of cardiac development has been well described in multiple species. In humans, the earliest recognizable cardiac structure is evident at 3 weeks of gestation and is soon followed by the onset of rhythmic heartbeats. By the middle of the third week of gestation, a functioning cardiovascular system is essential to satisfy the nutritional requirements of the developing human embryo, and by the eighth week of gestation, the majority of cardiac morphogenesis is complete. This review will summarize the stages of cardiac development from early cardiomyocyte specification to the later stages of chamber and septa formation, valvulogenesis, and development of the outflow tracts. In addition, the roles of the multiple cellular contributors that are necessary for normal heart formation will be discussed. Lastly, the intricacies of the molecular pathways regulating cardiac embryogenesis are beginning to be elucidated, and this review includes a summary of the key regulators and signaling pathways. This increased knowledge of normal cardiac morphogenetic processes has implications for human disease as mild perturbation of these developmental pathways results in congenital heart disease, the most common type of birth defect in humans.
Infrastructure and Manufacturing Productivity: Regional Accessibility and Development Level Effects

Infrastructure — and its consequences for regional development — has been treated in business, urban economics, regional science, geography and engineering literatures. Depending upon the tradition favored by the analyst, one might frame rather different questions. Duffy-Deno and Eberts (1991), for example, claim “The importance of public capital for regional growth stems from its effect on production and location decisions of private industry”. Accordingly, infrastructure might be studied to detect whether its early availability stimulates substantial accumulations of private capital investment. Assuming first that infrastructure is fixed capital — subsidized or wholly provided by the state — this could be approached as some variant of the industrial location question. Roads, bridges, railways, water supply, basic utilities (gas, electricity), assembled land and public services, and traditional public works are the staple infrastructure elements considered in such studies.
Determination of zirconium, hafnium, niobium, tantalum, molybdenum, and tungsten in aqueous solutions by radioisotopic excited x-ray fluorescence.

Previous investigations on the quantitative determination of sulfur, chlorine, potassium, calcium, scandium and titanium in aqueous solutions by a radioisotopic excited fluorescent spectrometer has been extended to include other elements which are very difficult to separate and determine quantitatively by chemical methods. Six elements taken for the investigation and some of the results to be presented in this paper are: (1) zirconium, (2) hafnium, (3) niobium, (4) tantalum, (5) molybdenum and (6) tungsten. As in previous investigations, aqueous solutions have been used because of the ease in obtaining exact concentrations and homogeneous mixtures of the elements under investigation.
Life Limiting Properties of Uncoated and Environmetal‐Barrier Coated Silicon Nitride at Higher Temperature

Life limiting properties of a commercial gas-turbine grade silicon nitride were determined with and without environmental barrier coatings (EBCs) at 1371°C in air. Uncoated silicon nitride, AS800, exhibited a significant life limiting phenomenon with a relatively low life prediction parameter n ≈ 10 either in dynamic fatigue or in stress rupture under flexure. This enhanced susceptibility to life limiting was also consistent in tensile stress rupture loading. By contrast, despite some limited data, AS800 with plasma-sprayed rare-earth multi-component hafnia or yittriahafnia EBCs showed much improved resistance to life limiting over the uncoated AS800, resulting in four to seven-fold life extension.
The Impact of Adding Improvisation to Sequential NPD Processes on Cost: TheModerating Effects of Turbulence

The ability to develop new products efficiently has become an important consideration in the current atmosphere of constrained budgets and fast-changing environments. New product development (NPD) researchers and practitioners have taken note, but there are limited and conflicting findings on the relationship between the type of NPD framework used for development and the ability to meet cost expectations under conditions of environmental change. In a study of over 400 NPD projects, we examined the impact of adding improvisation to sequential NPD process on meeting cost expectations under different conditions of turbulence. Our results support previous findings, but also demonstrate that turbulence moderates the direct effect, with the penalty for improvisation being less severe as environmental turbulence increases. For the practitioner, our results suggest that when efficiency is paramount, they may consider adopting a “throttled” approach to NPD, loosening control to allow for more improvisation where fruitful, while tightening control in other stages.
Real Options for Real Ventures

Black-Scholes is useful for valuing real options, but not in the way often used for new ventures. The use rests on an apparent analogy between real and stock options. Although conceptually helpful, a direct analogy is flawed for most real ventures. The most critical flaw is the assumption that the variance in new venture outcomes is a continuous time function and must be derived from a so-called tracking stock. The analogy also requires that the present value of venture cash flows be the equivalent of a current stock price in the Black-Scholes equation. Determining this certainty equivalent requires subjective inputs, for which guidance is usually lacking. This paper reviews the analogy problems and ways to resolve them for new venture situations, including the problem of estimating risk discounts for new ventures.
Students and computers: literacy, access, and standardization

During the past three semesters, course materials for a lower division undergraduate technology course have been placed on the campus computer network and Internet. The impetus for this is to create a paperless course, with materials and assignments accessed and submitted electronically. Due to problems with access, skill levels and software compatibility during the first semester, students enrolled in subsequent classes begin by responding to a survey that determines their skill levels in word processing, spreadsheets, databases, computer aided drafting (CAD), email and Internet applications. The survey also identifies where they use computers, whether they have one at home, and what software is being used.
Modeling Defect-Induced Phenomena

Elucidation of dissociation mechanisms, energy localization, and transfer phenomena in the course of explosive decomposition of energetic materials (EMs) are central for understanding, controlling, and enhancing the performance of these materials as fuels, propellants, and explosives. Quality of energetic materials is often judged using two main parameters: sensitivity to detonation and its performance. Low sensitivity is desired to make the material relatively stable to external stimuli, i.e., controllable and able of triggering rapid dissociation only when needed and not accidentally. Performance, on the other hand, is to be high to provide larger heat of the explosive reaction. These parameters do not necessarily correlate with each other and depend on many variables such as molecular and crystalline structures, history of samples, the particle size, crystal hardness and orientation, external stimuli, aging, storage conditions, and others. Mechanisms governing performance are fairly well understood whereas mechanisms of sensitivity are poorly known and need to be much more extensively studied. It is widely accepted though that the thermal decomposition reactions of the materials play a significant role in their sensitivity to mechanical stimuli and their explosive properties [1]. The decomposition of energetic materials can be initiated with a mechanical impact, thermal heating, a shock wave, or a spark. Such events in solids generate molecules in highly excited vibronic and/or electronic states. Clearly, the decomposition of solid explosives under shock, spark, laser, or plasma ignition must include contributions from both ground and excited electronic states. Excitation in the UV can markedly reduce the power requirements for detonation of some secondary explosives. Therefore, establishing the initial steps of high explosive (HE) decomposition is an important goal to pursue. Decomposition triggered by excited electronic states seems appealing because electronic excitation of the system to an unstable potential energy surface can result in rapid dissociation of a molecule and consequent chain reaction.
Hemagglutination by Bordetella bronchiseptica

A total of 53 isolates of Bordetella bronchiseptica from dogs and pigs were tested for their ability to agglutinate chicken, horse, sheep, dog, pig, and guinea pig erythrocytes. No differences in hemagglutinating activity were attributed to the animal origin of the bordetella isolates. Horse and dog erythrocytes consistently resulted in the strongest hemagglutination reactions, whereas only 4% of the B. bronchiseptica isolates produced weak agglutination of chicken erythrocytes. A total of 85% of the isolates agglutinated horse, sheep, dog, pig, and guinea pig erythrocytes. One canine isolate with hemagglutinating activity, strain 110H, was examined to determine the nature of the hemagglutinin(s) involved. Hemagglutination was always accompanied by hemadsorption, as determined by dark-field or phase-contrast microscopy. Treatment of cells and cell extracts with heat or protease K inhibited the hemagglutination reaction. Sonicated bacterial cells had a greater hemagglutinating ability than did unsonicated live bacteria. The hemagglutination reaction was not inhibited by any of 17 sugars nor by N- acetylglucosamine or ethylene glycol-bis-(β-aminoethyl ether)-N, N-tetraacetic acid. Hemagglutinins were not detected in sonic extracts nor in several bacterial subunit fractions, including isolated pili. Antigens in some of these preparations were, however, detectable by indirect hemagglutination with anti-B. bronchiseptica serum. Isolated pili could not be detected on the erythrocyte surface by electron microscopy; however, serial sections of erythrocytes agglutinated by the live Bordetella organisms showed that the bacterial outer membrane and the erythrocyte surface were separated by a space of approximately 20 nm. This study provided additional circumstantial evidence that B. bronchiseptica pili or at least heat-labile surface proteins which extend some distance from the bacterial surface are involved in hemagglutination. Multiple hemagglutinins are likely to exist within this species since one isolate lacking pili also agglutinated canine erthyrocytes. The hemagglutinins of B. bronchiseptica need to be isolated and characterized before the hemagglutination reaction can be applied to studies of attachment.
Fetal heart rate and tissue pH changes associated with repetitive aortic occlusion in the pregnant dog

Variations in fetal heart rate (FHR) and tissue pH (tpH) were studied simultaneously in 10 pregnant dogs at term during experimental fetal distress produced by subjecting the fetuses to short episodes of acute anoxia, which was produced by occlusion of thr maternal aorta. The fetal response to these anoxic episodes dependent on the initial value of the tpH. With tpH higher than or equal to 7.20, the tpH and FHR showed minimal or no response. With tpH between 7.20 and 7.10, the FHR showed a "delayed" deceleration and there was a sharp decline in tpH. With lower tpH, the variations in FHR and tpH were less accentuated. Also noted were unusual variations, such as "transient" or "irregular" FHR decelerations, and tpH "reactive alkalosis." In this acute experimental situation, tpH seemed to be a very sensitive indicator of fetal anoxia. The combined continuous monitoring of FHR and tpH for the diagnosis of fetal distress deserves further investigation.
On Burgers equation on a time-space scale

The Lax equation is introduced on a time-space scale. The viscous Burgers and the nonlinear Schrodinger dynamic equations on a time-space scale are deduced from the Lax equation by using the Ablowitz-Kaup-Newel-Segur-Ladik method. It is shown that the Burgers equation turns to the heat equation on a time-space scale by the Cole-Hopf transformation. Further, using the separation of variables, we deduce the formula for solutions of the boundary value problem for the heat and Burgers equation on a time-space scale in terms of Fourier series by Hilger exponential functions.
Prediction of formulation effects on dermal absorption of topically applied ectoparasiticides dosed in vitro on canine and porcine skin using a mixture-adjusted quantitative structure permeability relationship.

Topical application of ectoparasiticides for flea and tick control is a major focus for product development in animal health. The objective of this work was to develop a quantitative structure permeability relationship (QSPeR) model sensitive to formulation effects for predicting absorption and skin deposition of five topically applied drugs administered in six vehicle combinations to porcine and canine skin in vitro. Saturated solutions (20 μL) of (14) C-labeled demiditraz, fipronil, permethrin, imidacloprid, or sisapronil were administered in single or binary (50:50 v/v) combinations of water, ethanol, and transcutol (6 formulations, n = 4-5 replicates per treatment) nonoccluded to 0.64 cm(2) disks of dermatomed pig or dog skin mounted in flow-through diffusion cells. Perfusate flux over 24 h and skin deposition at termination were determined. Permeability (logKp), absorption, and penetration endpoints were modeled using a four-term Abrahams and Martin (hydrogen-bond donor acidity and basicity, dipolarity/polarizability, and excess molar refractivity) linear free energy QSPeR equation with a mixture factor added to compensate for formulation ingredient interactions. Goodness of fit was judged by r(2) , cross-validation coefficient, coefficients (q(2) s), and Williams Plot to visualize the applicability domain. Formulation composition was the primary determinant of permeation. Compounds generally penetrated dog skin better than porcine skin. The vast majority of permeated penetrant was deposited within the dosed skin relative to transdermal flux, an attribute for ectoparasiticides. The best QSPeR logKp model for pig skin permeation (r(2) = 0.86, q(2) s = 0.85) included log octanol/water partition coefficient as the mixture factor, while for dogs (r(2) = 0.91, q(2) s = 0.90), it was log water solubility. These studies clearly showed that the permeation of topical ectoparasiticides could be well predicted using QSPeR models that account for both the physical-chemical properties of the penetrant and formulation components.
An optimization model for gate reassignment in response to flight delays

In this paper, a binary integer program is formulated for the optimal reassignment of planes to gates in response to day-of flight delays. This program minimizes the total walking distance of those passengers either connecting or originating at an airport whose boarding passes for affected flights were issued prior to the reassignment of gates. A numerical illustration using operations of Continental Airlines at the George W. Bush Intercontinental Airport in Houston, Texas demonstrates the speed and efficiency of this program in both a real world and real time setting.
Reported changes in sexual behavior in response to AIDS in the United States.

Abstract Background . The AIDS epidemic has profoundly affected public health policy and everyday choices of individuals. Understanding the self-protective strategies adopted by the general population is crucial to designing appropriate and more effective primary AIDS prevention strategies. Methods . A probability sample of the U.S. adult population in 1992, the National Health and Social Life Survey ( n = 3,159), addressed detailed aspects of sexual behavior. How respondents changed their sexual behavior due to AIDS was recorded verbatim and categorized for analysis. Results . Twenty-nine percent of U.S. adults reported some sexual behavior change, primarily, reducing numbers of partners (12%), using condoms more frequently (9%), selecting partners more carefully (7%), changing attitude toward sex (4%), and abstinence (3%). Individuals most at risk show the greatest propensity to change although the actual risk-reduction strategies and the meanings assigned to those strategies vary considerably. Strategies are not all compatible with each other nor equally likely to be adopted by individuals with different lifestyles. Conclusions . Self-protective strategies to avoid AIDS are widespread, but primary prevention efforts should be targeted to particular circumstances and the self-protective propensities of each individual.
Crystal Structure of the Intermetallic Compound Mg 32 (AI,Zn) 49 and Related Phases

PHASE-DIAGRAM studies of the magnesium–aluminium–zinc system have established the existence of a compound with approximate composition Mg3Al2Zn3. Laves, Lohberg and Witte1 reported this compound to have a body-centred cubic structure with a0 = 14.16 A., and with the calculated number of atoms per unit cube equal to 161. They reported also that the phase in the magnesium–aluminium–copper system with approximate composition Mg4Al6Cu gives a closely similar X-ray diagram. They were not able to determine the structure.
A simple technique for calculating line profiles of inhomogeneous planetary atmospheres

Abstract The computation of synthetic spectra for planetary atmospheres in which multiple scattering is important usually requires lengthy numerical work. We obtain solutions to the appropriate equation of radiative transfer by use of a variational principle whose extremum is essentially the reflectivity. When considering light diffusely reflected from the atmospheres of the outer planets, the technique reduces the computational work enormously and is applicable to models in which the albedo varies strongly with optical depth as well.
Improve the viability of transplanted neural cells with appropriate sized neurospheres coated with mesenchymal stem cells

Consequences of central nervous system (CNS) physical injuries and neurodegenerative diseases are severe because the CNS has limited capacity to replace neurons lost through injuries or diseases. Neural stem cells (NSCs) are the most versatile and promising cell source for the regeneration of injured and diseased CNS. However, cell therapy faces many problems related to cell survival, control of cell fate and proper cell engraftment after transplantation. Cell survival is one of the most challenging technical issues as only a small percentage of implanted cells can survive after transplantation. These cells often die in the first few days after transplantation due to acute inflammation/immune response, trophic factor withdrawal, oxidative stress, excitotoxicity, hypoxia, or anoikis. To use appropriate size of cell aggregates, such as neurospheres, rather than individual cell suspension, may prevent anoikis and improve viability. Cells in aggregates or groups can form a community to provide paracrine signaling or trophic support for neighboring transplanted cells to be able to survive in the community manner. One important parameter in the neurosphere structure is the size or diameter. If the sphere size is too big, the nutrient and oxygen support for the cells in the core of the neurosphere will be limited or insufficient. If the sphere size is too small, the beneficial impact of the multicellular community may be limited. To this end, we hypothesize that the survival of transplanted NSCs may be improved with the transplantation of multicellular neurospheres as compared to the transplantation of individual cells in suspension, and there is an optimal range of the sphere size to get the highest viability for the transplanted neural cells. Another major factor is the immune response to the transplanted neural cells. Even with immunosuppressant used, host immune response can still jeopardize the viability of the transplanted cells. Mesenchymal stem cells (MSCs) have been demonstrated to possess immunosuppressive and neuroprotective properties. We further hypothesize that the viability of transplanted neural cells may be further improved in neurospheres coated with layers of MSCs on the surface of neurospheres by suppressing the host immune response at the transplantation site.
Analysis of Mating-Type Genes in the Chestnut Blight Fungus, Cryphonectria Parasitica

In nature, the chestnut blight fungus, Cryphonectria parasitica, has a mixed mating system; i.e., individuals in the same population have the ability to self and outcross. In the laboratory, C. parasitica appears to have a bipolar self-incompatibility system, typical of heterothallic ascomycetes; selfing is rare, although demonstrable. In this report we describe the cloning and sequencing of both mating-type idiomorphs and their flanking regions at the MAT locus in C. parasitica. The two idiomorphs, MAT1-1 and MAT1-2, are structurally similar to those of other pyrenomycetes described to date. MAT1-1 encodes three genes (MAT1-1-1, MAT1-1-2, and MAT1-1-3) and MAT1-2 encodes a single gene (MAT1-2-1). Unlike MAT idiomorphs in some ascomycetes, the sequences at both ends of the idiomorphs in C. parasitica show a relatively gradual, rather than abrupt, transition from identity in the flanking regions to almost complete dissimilarity in the coding regions. The flanking regions have repetitive polypyrimidine (T/C) and polypurine (A/G) tracts; the significance of these repetitive tracts is unknown. Although we found repetitive tracts in the flanks and gradual transition zones at the ends of the idiomorphs, we found no special features that would explain how selfing occurs in an otherwise self-incompatible fungus.
Ares I-X Separation and Reentry Trajectory Analyses

The Ares I-X Flight Test Vehicle was launched on October 28, 2009 and was the first and only test flight of NASA s two-stage Ares I launch vehicle design. The launch was successful and the flight test met all of its primary and secondary objectives. This paper discusses the stage separation and reentry trajectory analysis that was performed in support of the Ares I-X test flight. Pre-flight analyses were conducted to assess the risk of stage recontact during separation, to evaluate the first stage flight dynamics during reentry, and to define the range safety impact ellipses of both stages. The results of these pre-flight analyses were compared with available flight data. On-board video taken during flight showed that the flight test vehicle successfully separated without any recontact. Reconstructed trajectory data also showed that first stage flight dynamics were well characterized by pre-flight Monte Carlo results. In addition, comparisons with flight data indicated that the complex interference aerodynamic models employed in the reentry simulation were effective in capturing the flight dynamics during separation. Finally, the splash-down locations of both stages were well within predicted impact ellipses.
Test stand for shock compression of gas-impregnated solids

Electrically launched flyer plates are being used to produce shockwaves in gas-impregnated solids. A test stand has been constructed to deliver capacitively stored energy to a copper foil load. When the copper foil vaporizes and expands, a flyer plate is launched and collides with a gas-impregnated target. An RLC circuit was designed to minimize the effects of the underdamped circuit and variable impedance of the vaporizing copper foil while delivering the energy needed to accelerate the flyer plate. Velocity data will be collected with a framing camera and correlated with the mass of the flyer plate and the charge voltage. These data make it possible to determine the velocity in future experiments when the target is blocking the line of sight of the framing camera.
Androgen receptors, sex behavior, and aggression.

Androgens are intricately involved in reproductive and aggressive behaviors, but the role of the androgen receptor in mediating these behaviors is less defined. Further, activity of the hypothalamic-pituitary-gonadal axis and hypothalamic-pituitary-adrenal axis can influence each other at the level of the androgen receptor. Knowledge of the mechanisms for androgens’ effects on behaviors through the androgen receptor will guide future studies in elucidating male reproductive and aggressive behavior repertoires.
Computer Science, Mathematics, and the Undergraduate Curricula in Both.

(1981). Computer Science, Mathematics, and the Undergraduate Curricula in Both. The American Mathematical Monthly: Vol. 88, No. 7, pp. 472-485.
Protecting the Vulnerable

Too often, discussions of justice in health care take for granted a distributive framework. Such an approach holds that justice is primarily a problem of distributing scarce goods fairly among diff...
Quantum Cryptography with Optical Entanglement at 1.5 μm

We report on the engineering, preparation, and utilization of polarization entangled-photon states in the telecommunications window of 1.5 μm for secure quantum key distribution.
QPAR: A Quasi-Passive and Reconfigurable node for green next-generation optical access networks

Passive optical network (PON) is regarded as a promising solution for the broadband bandwidth bottleneck problem. However, due to its passive nature, legacy PON is limited by the static power distribution, which makes it power inefficient. To address this problem, we propose QPAR [4], a Quasi-Passive and Reconfigurable node, which enables dynamic power and wavelength assignment so as to save optical power budget in PON. In this paper, we study the power gains that can be achieved in PON employing QPAR, as well as different factors that may facilitate or prevent real QPAR deployments. We conduct extensive simulations to demonstrate the merits of QPAR. Results show that QPAR can achieve high optical power saving by intelligently redistributing the unnecessary power assigned to “close” optical network units (ONUs) in the network. The saved power can either be used to connect more ONUs, or extend the network reach without increasing the optical power budget.
A model for locating repair stations in a sequential manufacturing process

With the increasing complexity of final products, the sequential manufacturing process becomes very important. It breaks a production line into a linear sequence of simpler individual operations. By performing each individual operation step by step, we can manufacture a final product with the desired high complexity. For a given sequential manufacturing process with n operations S1, S2, …, Sn, we assume there is an operational cost ci and a success probability pi associated with each operation Si. After each operation, it is possible to locate a repair station Ri. In the repair station, the first task is to test defective products at a unit test cost ti, j (which may depend on the location of the previous repair station Rj). Then the defectives are fixed at a unit repair cost ri, j (which may also depend on the location of the previous station Rj). The settings of repair stations affect both the total manufacturing cost and final yield. Our major economic incentive is to minimize the unit manufacturing cost per fault — free final product by locating a number of repair stations at proper places. Obviously there are 2n possible combinations in total. A dynamic programming model with an algorithm of 0(n3) complexity is used to solve this problem.
Effect of retinoic acid on cell-cell adhesiveness in cloned BHK21/C13 cells which form piling-up colonies

Abstract The effect was studied of retinoic acid (RA) on cell-ceil adhesiveness in Ag8-1 cells, which are piling-up colony-forming cells cloned from a Syrian hamster kidney fibroblastic cell line BHK21/C13. From the piled-up part of the colonies grown with RA (10 μM), many cells were dissociated by mere shaking or pipetting. The dissociated cells soon adhered to and spread on plastic surfaces in the presence of RA. The number of cells per colony increased almost at the same rate in the presence or absence of RA. The effect of RA on the appearance of cells dissociable from colonies was noticeable above 0.1 μM, prominent from 1 to 10 μM, greater when added in the earlier stages of colony formation and negligible when added just before the dissociation assay. Single cells from the monolayer culture grown with RA (10 μM) had less tendency to aggregate than did those from the control culture. Cells from the colonies grown with RA adhered to and spread on a plastic dish for bacterial use, but control cells seldom adhered. These results indicate that RA decreases the cell-cell adhesiveness or suppresses the development of it but increases cell-substratum adhesiveness.
Effects of biofilms on zebra mussel postveliger attachment to artificial surfaces

. The zebra mussel is an introduced fouling organism in North American inland waters. This field study tested whether natural biofilms, formed by covering substrata with a 100-μm mesh that allows microorganisms to attach and films to develop in the absence of postveligers, influenced the attachment of zebra mussel postveligers to artificial surfaces. Low-wettable polycarbonate and wettable glass surfaces were used in the experiments over four field seasons to study biofilm formation (1997–1998) and mussel attachment (1998–2000). The presence of the mesh did not quantitatively affect biofilm development on either substratum as determined by microscopic direct counts and colony-forming units on R2A agar. Natural biofilms on polycarbonate surfaces positively influenced postveliger attachment compared to substrata that initially had no film (ANOVA, p-values ranged from ≤.05 to ≤.001). Biofilms did not influence postveliger attachment to glass surfaces (ANOVA, p>.05). Attachment to both substrata was similar on surfaces with and without previously settled postveligers. Based on these results, we conclude that biofilms can enhance postveliger attachment to some but not all artificial surfaces.
Noninvasive assessment of left atrial maximum dP/dt by a combination of transmitral and pulmonary venous flow.

OBJECTIVES: The study assessed whether hemodynamic parameters of left atrial (LA) systolic function could be estimated noninvasively using Doppler echocardiography. BACKGROUND: Left atrial systolic function is an important aspect of cardiac function. Doppler echocardiography can measure changes in LA volume, but has not been shown to relate to hemodynamic parameters such as the maximal value of the first derivative of the pressure (LA dP/dt(max)). METHODS: Eighteen patients in sinus rhythm were studied immediately before and after open heart surgery using simultaneous LA pressure measurements and intraoperative transesophageal echocardiography. Left atrial pressure was measured with a micromanometer catheter, and LA dP/dt(max) during atrial contraction was obtained. Transmitral and pulmonary venous flow were recorded by pulsed Doppler echocardiography. Peak velocity, and mean acceleration and deceleration, and the time-velocity integral of each flow during atrial contraction was measured. The initial eight patients served as the study group to derive a multilinear regression equation to estimate LA dP/dt(max) from Doppler parameters, and the latter 10 patients served as the test group to validate the equation. A previously validated numeric model was used to confirm these results. RESULTS: In the study group, LA dP/dt(max) showed a linear relation with LA pressure before atrial contraction (r = 0.80, p 0.30. By stepwise and multiple linear regression analysis, LA dP/dt(max) was best described as follows: LA dP/dt(max) = 0.1 M-AC +/- 1.8 P-V - 4.1; r = 0.88, p < 0.0001, where M-AC is the mean acceleration of transmitral flow and P-V is the peak velocity of pulmonary venous flow during atrial contraction. This equation was tested in the latter 10 patients of the test group. Predicted and measured LA dP/dt(max) correlated well (r = 0.90, p < 0.0001). Numerical simulation verified that this relationship held across a wide range of atrial elastance, ventricular relaxation and systolic function, with LA dP/dt(max) predicted by the above equation with r = 0.94. CONCLUSIONS: A combination of transmitral and pulmonary venous flow parameters can provide a hemodynamic assessment of LA systolic function.
Aortic sinotubular atherosclerotic debris associated with cerebral embolic events can be identified by transthoracic echocardiography.

Objective: To evaluate the association between the presence of aortic sinotubular debris (STAD) identified by transthoracic echocardiography (TTE) and embolic strokes. Background: The presence of atherosclerotic debris in the ascending aorta or aortic arch detected by transesophageal echocardiography or epiaortic echocardiography has been well established to be correlated with embolic stroke or other thromboembolic events. No data are available on the role of TTE in describing aortic pathology in thromboembolic events. Methods: We identified 60 transthoracic echocardiographic studies from 11,275 studies, in which STAD was diagnosed. The charts of these patients (group 1; mean age 67 ± 10 years) were reviewed and compared with those of 57 patients (group 2) without STAD, matched for age, gender and risk factors for advanced atherosclerosis. The results of brain imaging procedures, carotid duplex and coronary angiography were also reviewed. Results: Ischemic stroke was found in 15 of group 1 (25%) and 4 patients of group 2 (7%, odds ratio = 4.4; 95% confidence interval, 1.3–19.4, p = 0.008). The average thickness of STAD was 0.7 ± 0.2 cm in stroke patients and 0.6 ± 0.2 cm in patients without stroke (p = n.s.). STAD was associated with ≤40% carotid artery stenosis. Conclusion: STAD detected by TTE is strongly associated with embolic strokes. Our findings expand the role of TTE in the evaluation of patients with embolic strokes.
Intracavity laser intensity modulation at frequencies from 0.01 Hz to 1.2 GHz

An acoustooptic output coupler (cavity-dumper) is employed to intensity modulate the radiation produced by argon ion or dye lasers. By using an amplitude modulated rf carrier, heterodyning two acoustically upshifted beams, heterodyning one upshifted beam against the unshifted beam, or heterodyning an upshifted beam against a downshifted beam, a continuous range of frequencies from 0.01 Hz to 1.2 GHz could be generated. Phase fluorimetric determinations of subnanosecond lifetimes demonstrate the utility of the source.
Nest-Site Selection in a Postfire Landscape: Do Parents Make Tradeoffs Between Microclimate and Predation Risk?

ABSTRACT. Maternal preference for nest sites is predicted to be an adaptive consequence of selective pressures acting on parents and young at the nest site. Nest predation risk has been linked to nest-site placement in birds, but microclimatic extremes can impose fitness costs on both adults and young, and these two factors may conflict. I used the temporal and spatial variation in microclimatic conditions and nest predation risk generated by variation in wildfire severity to examine the relationship between nest-site preference, nest microclimate, and fitness costs to parents and young in the Dark-eyed Junco (Junco hyemalis), a facultative cavity-nester. Adults preferred to select exposed nest sites oriented toward the north—sites that consistently had the most moderate thermal regimes. Nestlings reared in burrow-type nests gained mass more slowly and experienced retarded skeletal growth compared with exposed nests, but slower growth was not explained by suboptimal nest temperatures, nestling provisionin...
Transition Metal Complex-Doped Hydroxyapatite Layers on Porous Silicon

In this work, the encapsulation of the transition metal complexes cis-Pt(NH3)2Cl2, Ru(bpy)32+, and Ru(phen)32+ within layers of hydroxyapatite on a porous Si/Si substrate are described. These specific complexes were selected as a consequence of their biological activity (cis-Pt(NH3)2Cl2) or polynucleotide binding ability (Ru(bpy)32+ and Ru(phen)32+). The complex-doped hydroxyapatite/porous Si/Si materials have been characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, secondary ion mass spectrometry, and photoluminescence spectroscopy. It is possible to exercise some control of the release of a given complex into the surrounding medium through thermal heating of the complex-doped hydroxyapatite/porous Si/Si structure.
Transcriptional Regulation of Cardiac Development: Implications for Congenital Heart Disease and DiGeorge Syndrome

In recent years, impressive advances have occurred in our understanding of transcriptional regulation of cardiac development. These insights have begun to elucidate the mystery of congenital heart disease at the molecular level. In addition, the molecular pathways emerging from the study of cardiac development are being applied to the understanding of adult cardiac disease. Preliminary results support the contention that a thorough understanding of molecular programs governing cardiac morphogenesis will provide important insights into the pathogenesis of human cardiac diseases. This review will focus on examples of transcription factors that play critical roles at various phases of cardiac development and their relevance to cardiac disease. This is an exciting and burgeoning area of investigation. It is not possible to be all-inclusive, and the reader will note important efforts in the areas of cardiomyocyte determination, left-right asymmetry, cardiac muscular dystrophies, electrophysiology and vascular disease are not covered. For a more complete discussion, the reader is referred to recent reviews including the excellent compilation of observations assembled by Harvey and Rosenthal (1).
Solvent effects on chemical processes. 8. Demethylation kinetics of aspartame in binary aqueous-organic solvents.

The kinetics of demethylation of aspartame were studied in binary aqueous–organic solvent mixtures at 25 °C under two solution conditions, namely 1.0 M HCl (pH 0.28 in water) and carbonate buffer (pH 10.1 in water). Under these conditions solvent effects on the acid dissociation constants of aspartame do not complicate the interpretation of the kinetics. The organic cosolvents were acetone, acetonitrile, dimethyl sulfoxide, dioxane, tetrahydrofuran, and methanol. The observed kinetic solvent effects were modest in magnitude, not exceeding a factor of 3 in rate constant, relative to the fully aqueous solution. The rate changes included both increases and decreases, and in some solvent mixtures extrema were observed. It is concluded that at least two contributory factors, identified as an electrostatic (dielectric constant) effect and a solvation effect, must be operating to produce the observed kinetic solvent effects.
Thermal polycondensation of poly(diol citrate)s with tethered quaternary ammonium biocides

The synthesis and characterization of a series of novel, antimicrobial, aliphatic polyesters based on citric acid, alkanediols, and quaternary ammonium salt (QAS) diols is described. These materials possess a wide range of mechanical and thermal properties (storage modulus, E′ = 1.03–17.53 MPa at 25 °C; Tg = −15.7–38.6 °C) primarily dictated by alkanediol selection and the presence of biocide. Surface analysis via contact angle and FTIR-ATR studies indicate the presence of biocide at the material/air interface providing high antimicrobial activity (5–7 log kill of S. aureus over controls) for all materials containing tethered QAS. Hydrolysis of these cross-linked materials was also highly controlled based on the QAS, alkanediol structure, and curing duration; and significant hydrolysis occurs in as little as 4 weeks.
A Computer-Assisted 3D Model for Analyzing the Aggregation of Tumorigenic Cells Reveals Specialized Behaviors and Unique Cell Types that Facilitate Aggregate Coalescence

We have developed a 4D computer-assisted reconstruction and motion analysis system, J3D-DIAS 4.1, and applied it to the reconstruction and motion analysis of tumorigenic cells in a 3D matrix. The system is unique in that it is fast, high-resolution, acquires optical sections using DIC microscopy (hence there is no associated photoxicity), and is capable of long-term 4D reconstruction. Specifically, a z-series at 5 μm increments can be acquired in less than a minute on tissue samples embedded in a 1.5 mm thick 3D Matrigel matrix. Reconstruction can be repeated at intervals as short as every minute and continued for 30 days or longer. Images are converted to mathematical representations from which quantitative parameters can be derived. Application of this system to cancer cells from established lines and fresh tumor tissue has revealed unique behaviors and cell types not present in non-tumorigenic lines. We report here that cells from tumorigenic lines and tumors undergo rapid coalescence in 3D, mediated by specific cell types that we have named “facilitators” and “probes.” A third cell type, the “dervish”, is capable of rapid movement through the gel and does not adhere to it. These cell types have never before been described. Our data suggest that tumorigenesis in vitro is a developmental process involving coalescence facilitated by specialized cells that culminates in large hollow spheres with complex architecture. The unique effects of select monoclonal antibodies on these processes demonstrate the usefulness of the model for analyzing the mechanisms of anti-cancer drugs.
Relationship between bone morphology and bone quality in male tibias: implications for stress fracture risk.

Biomechanical properties were assessed from the tibias of 17 adult males 17-46 years of age. Tissue-level mechanical properties varied with bone size. Narrower tibias were comprised of tissue that was more brittle and more prone to accumulating damage compared with tissue from wider tibias. Introduction: A better understanding of the factors contributing to stress fractures is needed to identify new prevention strategies that will reduce fracture incidence. Having a narrow (i.e., more slender) tibia relative to body mass has been shown to be a major predictor of stress fracture risk and fragility in male military recruits and male athletes. The intriguing possibility that slender bones, like those shown in animal models, may be composed of more damageable material has not been considered in the human skeleton. Materials and Methods: Polar moment of inertia, section modulus, and antero-posterior (AP) and medial-lateral (ML) widths were determined for tibial diaphyses from 17 male donors 17-46 years of age. A slenderness index was defined as the inverse ratio of the section modulus to tibia length and body weight. Eight prismatic cortical bone samples were generated from each tibia, and tissue-level mechanical properties including modulus, strength, total energy, postyield strain, and tissue damageability were measured by four-point bending from monotonic (n = 4/tibia) and damage accumulation (n = 4/tibia) test methods. Partial correlation coefficients were determined between each geometrical parameter and each tissue-level mechanical property while taking age into consideration. Results: Significant correlations were observed between tibial morphology and the mechanical properties that characterized tissue brittleness and damageability. Positive correlations were observed between measures of bone size (AP width) and measures of tissue ductility (postyield strain, total energy), and negative correlations were observed between bone size (moment of inertia, section modulus) and tissue modulus. Conclusions: The correlation analysis suggested that bone morphology could be used as a predictor of tissue fragility and stress fracture risk. The average mechanical properties of cortical tissue varied as a function of the overall size of the bone. Therefore, under extreme loading conditions (e.g., military training), variation in bone quality parameters related to damageability may be a contributing factor to the increased risk of stress fracture for individuals with more slender bones.
The plasma catecholamine stress response is characteristic for a given animal over a one-year period.

Abstract The same male and female rats with indwelling jugular catheters were stressed (immobilization) on two occasions at the ages of 3 to 4 and 15 to 16 months. Plasma levels of the catecholamines (CA) norepinephrine (NE) and epinephrine (E) were determined before and during stress at each session. During stress, plasma NE and E levels increased markedly. At the younger age, female animals showed markedly higher CA levels than male animals. After one year, stress CA levels were higher for both sexes, but had increased markedly in male and little in female animals. A positive correlation was found between the plasma CA stress response of individual animals at both sessions; this correlation was stronger for males and NE. This indicates that “high” responders usually remain high responders, “low” responders remain low and intermediate responders intermediate. In conclusion, the plasma CA stress response increases markedly in male, but little in female rats over the period of 1 year and the relative magnitude of the individual stress response remains a characteristic of each given animal.