cssi/SciSciGPT-SciSciNet huggingface dataset:
High-speed x-ray phase contrast imaging and digital image correlation analysis of microscale shock response of an additively manufactured energetic material simulant

The performance of energetic materials subjected to dynamic loading significantly depends on their micro- and meso-scale structural morphology. The geometric versatility offered by additive manufacturing opens new pathways to tailor the performance of these materials. Additively manufactured energetic materials (AMEMs) have a wide range of structural characteristics with a hierarchy of length scales and process-inherent heterogeneities, which are hitherto difficult to precisely control. It is important to understand how these features affect AMEMs’ response under dynamic/shock loading. Therefore, temporally and spatially resolved measurements of both macroscopic behavior and micro- and meso-level processes influencing macroscopic behavior are required. In this paper, we analyze the shock compression response of an AMEM simulant loaded under several impact conditions and orientations. X-ray phase contrast imaging (PCI) is used to track features across the observed shock front and determine the linear shock velocity vs particle velocity equation of state, as well as to quantify the interior deformation fields via digital image correlation (DIC) analyses. Photon Doppler velocimetry is simultaneously used to measure the particle velocities of the specimens, which are consistent with those obtained from x-ray PCI. The DIC analyses provide an assessment of the average strain fields inside the material, showing that the average axial strain depends on the loading intensity and reaches as high as 0.23 for impact velocities up to 1.5 km/s. The overall results demonstrate the utility of x-ray PCI for probing “in-material” equation of state and interior strains associated with dynamic shock compression behavior of the AMEM simulant.
Gelatin Promotes Cell Retention Within Decellularized Heart Extracellular Matrix Vasculature and Parenchyma.

Recellularization of organ decellularized extracellular matrix (dECM) offers a potential solution for organ shortage in allograft transplantation. Cell retention rates have ranged from 10 to 54% in varying approaches for reseeding cells in whole organ dECM scaffolds. We aimed to improve recellularization by using soluble gelatin as a cell carrier to deliver endothelial cells to the coronary vasculature and cardiomyocytes to the parenchyma in a whole decellularized rat heart. Rat aortic endothelial cells (RAECs) were perfused over decellularized porcine aorta in low (1%) and high (5%) concentrations of gelatin to assess attachment to a vascular dECM model. After establishing cell viability and proliferation in 1% gelatin, we used 1% gelatin as a carrier to deliver RAECs and neonatal rat cardiomyocytes (NRCMs) to decellularized adult rat hearts. Immediate cell retention in the matrix was quantified, and recellularized hearts were evaluated for visible contractions up to 35 days after recellularization. We demonstrated that gelatin increased RAEC attachment to decellularized porcine aorta; blocking integrin receptors reversed this effect. In the whole rat heart gelatin (1%) increased retention of both RAECs and NRCMs respectively, compared with the control group (no gelatin). Gelatin was associated with visible contractions of NRCMs within hearts (87% with gelatin vs. 13% control). Gelatin was an effective cell carrier for increasing cell retention and contraction in dECM. The gelatin-cell-ECM interactions likely mediated by integrin.
Trillium: The code is the IR

GPUs are the platform of choice for many general purpose workloads such as machine learning. This is driving demand for better GPGPU support in virtualized environments like the cloud. Despite significant research attention, GPGPU virtualization remains largely an open problem due to the challenge of balancing performance against key virtualization properties: compatibility, isolation, and interposition. Consequently, two different approaches to GPGPU virtualization have been adopted by the industry: Cloud service providers, such as AWS, support GPU-capable VMs using PCIe-passthrough techniques that bypass virtualization entirely, sacrificing its benefits; Virtualization vendors, such as BitFusion and Dell XaaS, support GPGPU virtualization using user-space API-remoting, which retains some of the benefits of virtualization, but elides hypervisor interposition, thereby giving up key virtualization properties.We hypothesize that while API-remoting may be the only viable software virtualization technique (as it interposes the only practical interface), API-remoting should not be implemented purely in user-space. We revisit VMware’s SVGA in the context of GPGPU computing and find that hypervisor-mediated API-remoting is efficient: Decoupling device virtualization from GPU ISA virtualization is key to preserving the raw speedup from GPGPU acceleration, while also preserving the benefits of hypervisor-mediation: migration, isolation, fairness, etc.
Estimating model inadequacy in ordinary differential equations with physics-informed neural networks

Abstract A number of physical systems can be described by ordinary differential equations. When physics is well understood, the time dependent responses are easily obtained numerically. The particular numerical method used for integration depends on the application. Unfortunately, when physics is not fully understood, the discrepancies between predictions and observed responses can be large and unacceptable. In this paper, we propose an approach that uses observed data to estimate the missing physics in the original model (i.e., model-form uncertainty). In our approach, we first design recurrent neural networks to perform numerical integration of the ordinary differential equations. Then, we implement the recurrent neural network as a directed graph. This way, the nodes in the graph represent the physics-informed kernels found in the ordinary differential equations. We quantify the missing physics by carefully introducing data-driven in the directed graph. This allows us to estimate the missing physics (discrepancy term) even for hidden nodes of the graph. We studied the performance of our proposed approach with the aid of three case studies (fatigue crack growth, corrosion-fatigue crack growth, and bearing fatigue) and state-of-the-art machine learning software packages. Our results demonstrate the ability to perform estimation of discrepancy, reducing gap between predictions and observations, at reasonable computational cost.
Should an Eminent Domain Property Taking be Allowed to Cause a Mortgage Default and Possible Bankruptcy

This case exposes students to the ethical and legal issues property owners face during eminent domain proceedings in an environment of downward spiraling housing prices. Current federal and state eminent domain laws have no provisions for situations where property owners are significantly underwater on their mortgages. The potential outcome is an otherwise financially viable loan holder being saddled with a large deficiency judgment, possibly needing to file for bankruptcy protection.
Randomized controlled trial of an education-based intervention to improve medication adherence: Design considerations in the medication adherence in glaucoma to improve care study.

Background:Glaucoma treatment requires patients to follow daily, often times complex, eye drop regimens, but adherence is poor for many patients, putting them at risk for irreversible vision loss. ...
Library Director as Opportunity Identifier

Gary dropped into Will's office shortly after 9:00 a.m. for one of their occasional IT/Library breakfast meetings to catch up on projects and events at the law school. Today, Gary updated Will on the library's goals to redesign the library's computer lab to be more conducive to current teaching methods and technologies and to experiment with creating subject-specific intranet pages for faculty in specific areas. Will offered the assistance of his web designers on the intranet pages, but Gary politely declined, privately worried that the project would taken over by IT if it did well. Will spent a moment puzzling over this, but then shrugged his shoulders and ran down IT's upcoming projects: upgrading the moot court room's technology, prepping a new courseware system for beta testing, and building a database for the files of the recently established center for health and the environment. Will was becoming frustrated with the two latter projects, as he was having a hard time finding faculty willing to do the testing and the center director kept changing her mind on what she wanted in the database. The two commiserated on how difficult it was to get faculty input at the front end but how vocal they were after any change had been implemented.
Impact of Valve Type (Ross vs. Mechanical) on Health-Related Quality of Life in Children and Young Adults with Surgical Aortic Valve Replacement.

The impact of aortic valve replacement (AVR) type on health-related quality of life (HRQOL) in adolescents and young adults is unclear, but may vary depending on need for anticoagulation or re-intervention. We sought to determine the differences in HRQOL following AVR with either the Ross procedure or mechanical AVR in this young population. Patients 14–35 years old and at least 1 year post-AVR were included. HRQOL was assessed using the Short Form-36 (SF-36). Valve-specific concerns regarding anticoagulation and reoperation were also assessed. Clinical outcome data were obtained by chart review. A total of 51 patients were enrolled: 24 (47%) Ross and 27 (53%) mechanical AVR. Ross patients were younger at time of AVR (16 vs. 22 years, p < 0.01) and study enrollment (23.7 vs 29.5 years, p < 0.01). Median follow-up from AVR to study enrollment was similar (5.4 years for Ross vs. 5.6 years for mechanical, p = 0.62). At last follow-up, clinical outcomes including cardiac function, functional class, and aortic valve re-intervention rates were similar between groups, although mechanical valve patients had more bleeding events (p = 0.012). SF-36 scores were generally high for the entire cohort, with no significant difference between groups in any domain. Mechanical AVR patients reported more concern about frequency of blood draws (p < 0.01). Concern for reoperation was similar between both groups. Despite more bleeding events and concern about the frequency of blood draws, adolescents and young adults with mechanical AVR reported similarly high levels of HRQOL compared to those following Ross AVR.
Phase II multicenter study of talazoparib for somatic BRCA1/2 mutant metastatic breast cancer.

TPS1110Background: PARP inhibitors are approved for the treatment of HER2 negative metastatic breast cancer (MBC) with germline BRCA1/2 mutations, based on phase III studies demonstrating an improv...
Comparing numerical accuracy and stability for different horizontal discretizations in MPAS-Ocean

Abstract This manuscript investigates the effectiveness of two possible horizontal discretizations for the global ocean model MPAS-Ocean, both applied to Spherical Centroidal Voronoi Tessellations (SCVTs). The first discretization is TRiSK, a C-grid, finite-volume method, that possesses many desirable mimetic properties, but has a low order accuracy. The second discretization was introduced for the first time by Peixoto (2016), and consists of modifications to the TRiSK scheme designed to achieve at least first-order accuracy in the L ∞ norm, with the loss of some of the mimetic properties. Tests on shallow-water and primitive-equation models show that the scheme due to Peixoto is indeed more accurate, but presents stability issues with respect to TRiSK. TRiSK is indeed found to be often more stable in time and more robust with respect to errors in the geometric properties of the grid.
Research and Practice in Distance Education for K-12 Students with Disabilities:

This review of literature highlights the empirical work to date in the area of K-12 distance education and online learning. While research indicates that distance and online learning can be equally effective as compared to more traditional learning environments for many students, there is little empirical evidence to suggest that previously validated face-to-face best practices can be effective in the online environment or if students with disabilities have similarly parallel experiences. Technology/media—the debate as to whether it is a part of instructional design or an inert component of the learning environment seems to be ending as the sophistication of technology changes the very nature of instruction and demonstrates the need for empirically validating practices in this new environment. The potential impact on rural schools and districts is of particular import in light of their often-critical need for access to qualified teachers and advanced coursework for their students. We conclude with conside...
Voltammetry study of quinoxaline in aqueous electrolytes

Abstract Organic compounds have recently received considerable attention as active materials in redox flow batteries (RFBs) due to their good electrochemical reversibility, high theoretical energy densities, and promise for low cost production. Until now, organic active material candidates for aqueous RFBs have been limited to the quinone family, a set of aromatic-derived organic molecules, distinguished by an even number of ketone (R C( O) R′) groups. This work aims to elucidate and optimize the electrochemical behavior of quinoxaline, an organic molecule consisting of fused benzene and pyrazine rings, in aqueous electrolytes. More than 30 electrolytes are screened by cyclic voltammetry, and the five most promising electrolytes are investigated further using rotating disk voltammetry. Electrochemical behavior of quinoxaline shows pH dependent thermodynamics and reaction mechanisms, while chloride-containing supporting electrolytes greatly enhance solubility. This study sheds light on the promising characteristics of quinoxaline as a low potential compound for aqueous RFBs; quinoxaline has a redox potential of E° ≈ −0.02 V vs. RHE, is soluble up to ∼4.5 M in water, exhibits a two-electron transfer capability, and possesses a low molecular weight (130.15 g mol −1 ), resulting in a theoretical capacity of 410 mAh g −1 .
Teaching parametric cubic curves with applets

We are investigating the use of Java applets as an instructional aid in a Computer Graphics course. The properties and behaviors of parametric cubic curves are difficult to explain using static media and the mathematics involved often results in student anxiety and disinterest. In an attempt to help the students gain a meaningful understanding of these important concepts, we are developing a series of applets illustrating key concepts. We hope to find the applets effective in a variety of ways; as a demonstration tool during lecture, as an interactive hand-on experimentation tool for the individual student, as well as a key component in a web-based learning environment.Currently we are illustrating various aspects of Bezier Curves, but plan to extend the set of applets to include other parametric curves and perhaps surfaces. Interactive applets allow students to observe curve behavior as control points are moved and to observe the bounding convex hull property. Such applets are easy to write and commonly found on the web. We are attempting a more intensive learning experience by illustrating the relationship between blending functions (the Bernstein Polynomials) and the curve shape. The de Castlejau approach to finding a point on the curve and general curve subdivision are also illustrated. We furthermore attempt to explain different types of continuity at the juncture of two curves by allowing the student to experiment with curves under various continuity constraints.
The carboxyl-terminal sequence of porcine pepsin.

Abstract The sequence of 27 residues at the carboxyl end of the single polypeptide chain of porcine pepsin has been found to be: -Ile-Leu-Gly-Asp-Val-Phe-Ile-Arg-Gln-Tyr-Tyr-Thr-Val-Phe-Asp-Arg-Ala-Asn-Asn-Lys-Val-Gly-Leu-Ala-Pro-Val-Ala. The peptides from which this sequence has been derived were isolated from tryptic and chymotryptic digests of pepsin and its reduced aminoethylated and trifluoracetylated derivatives. All 3 of the strongly basic residues in pepsin (1 lysine and 2 arginine residues) are thus found in this terminal segment of the chain. There is no half-cystine residue in this portion of the molecule, and hence the crosslinking of the enzyme by three —S—S— bonds occurs within a highly acidic sequence of about 300 residues in which the only basic residue is that of the single histidine. The absence of positive charges in this sequence undoubtedly contributes to the acid stability and alkali lability of the enzyme.
Illumination modelling in 3D sonar images

Summary form only given. Software has been developed to obtain a 3D perspective view of Pacific Ocean bottom terrain by merging side-looking sonar images with ocean bottom terrain elevation data (bathymetry). The observer can be positioned at various locations and see the terrain from different viewpoints. However, the side-looking sonar images published by the USGS are mosaic images manually compiled from the postprocessed raw data. Different pieces of the data may have different processing parameters, leading to difficulty of interpretation. The author has performed line-source illumination modeling for five areas of the Pacific Ocean. The reflectivity of a pixel in the image depends on the acoustic coefficient mismatch and the geometrical relationship between the incoming ray and the orientation of the surface. The synthesized image from the illumination of the model is due to geometric effect. It is displayed in a separate window side by side with the perspective view. The intent is to be able to identify the dominant geometrical effect in the perspective view so that interpretation of acoustic reflectance is better. >
Modeling: The Role Of Atomistic Simulations

A major advantage of atomistic simulations is that a detailed picture of the model under investigation is available, and so they have been very instrumental in explaining the connection of macroscopic properties to the atomic scale. Simulations play a significant role in the development and testing of theories. For example, simulations have been extensively used to test the mode-coupling theory (MCT). The theory predicts that at some critical temperature Tc, known as the mode-coupling temperature, the supercooled liquid undergoes a structural arrest, prohibiting the system from accessing all possible states, thus, essentially undergoing an ergodic to nonergodic transition. It gives definite predictions on various correlation functions that can be calculated directly in simulations. Simulations and MCT have played a tremendous role in elucidating a majority of what we now understand about the dynamics of glass-forming systems. Simulations can also be used to compare with experimental results to validate the model, so that one can use simulation results to measure properties not accessible to experiments. In many cases, as will be illustrated in the next sections, results of simulations motivate experimental investigations. Part of the goal of this chapter is to examine the contributions of atomic simulations to the current statemore » of understanding of metallic glasses.« less
Sound Speed and Attenuation in Multiphase Media

Abstract : This report discusses an investigation of the sound speed and attenuation in multiphase media, sandy and muddy sediments, that has shown that a simplified-Biot theory adequately predicts the sound speed and attenuation in sandy sediments with porosities of less than 65%. In addition for muddy sediments with porosities of greater than 70% mixture theory can describe the sound speed. This report discusses the experimental and theoretical basis for these conclusions and related this investigation to other contemporary ONR sponsored research projects. A key finding is the conclusion that in waveguides with a sandy boundary that the effective attenuation obeys a power law with an exponent of 1.8 as proposed by Rosenfeld (2001) and Holmes (2007). Theory predicted a quadratic dependence, exponent of 2. This research has shown that energy removed by shear wave conversion explains this difference, that is the exponent of 1.8 compared to 2. Finally a card house theory was developed to explain the properties of high porosity muddy sediments and that a Mallock-Wood mixture equation describes the slow sound speed.
Enhancing Protocol Evaluation Through Semantic Modification of Local Benchmarks

A computer based evaluation is essential to allow us to assess students’ protocols without human intervention in R SAT (Reading Strategy Assessment Tool). Word matching and Latent Semantic Analysis (LSA) approaches were explored for use in the evaluation of protocols and. experimentally it was found that word matching alone outperformed LSA or LSA in combination with word matching. Why does LSA not work well with the R SAT protocol evaluation? This paper demonstrates that modifying the benchmarks on which it is based can indeed benefit its performance. A variety of local benchmark modifications are investigated and results are compared against human expert. The preliminary results show that modified local benchmarks improve the R SAT protocol evaluation on local bridging strategy: 0.1 increase in correlation and 8% increase in percent agreement between original benchmarks and modified benchmarks.
Measuring buffer-gas pressure in sealed glass cells

In alkali rf-discharge lamps used for optical pumping in atomic clocks and magnetometers, a buffer-gas (Kr or Xe) allows electrons to extract energy from an rf-field, and these energized electrons eventually produce alkali resonant light. Contrary to naive intuition, rf-discharge lamps can lose their noble-gas buffer over time. Recently, we began a long-term experimental program to better understand the mechanism of noble-gas loss in rf-discharge lamps, and needed a non-destructive means of measuring buffer-gas pressure in sealed glass cells. For this purpose, we employ the Kazantsev, Smirnova, and Khutorshchikov (KSK) technique, which is based on inferring buffer-gas pressure from the collision shift of an alkali ground-state hyperfine transition frequency ν hfs . Here, we discuss the basic the KSK technique and two modifications that we have implemented for its improvement: use of a diode laser for optical pumping, and extrapolation of ν hfs to zero magnetic field. Testing our system's long-term performance with a very low pressure reference cell (i.e., 3.3 torr Xe), we find a reproducibility of 0.2% and an absolute accuracy of 5%. Further, our systematic drift is less than one mtorr/month.
Distribution of flunixin meglumine and firocoxib into aqueous humor of horses.

Background: Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used systemically for the treatment of inflammatory ocular disease in horses. However, little information exists regarding the ocular penetration of this class of drugs in the horse. Objective: To determine the distribution of orally administered flunixin meglumine and firocoxib into the aqueous humor of horses. Animals: Fifteen healthy adult horses with no evidence of ophthalmic disease. Methods: Horses were randomly assigned to a control group and 2 treatment groups of equal sizes (n = 5). Horses assigned to the treatment groups received an NSAID (flunixin meglumine, 1.1 mg/kg PO q24h or firocoxib, 0.1 mg/kg PO q24h for 7 days). Horses in the control group received no medications. Concentrations of flunixin meglumine and firocoxib in serum and aqueous humor and prostaglandin (PG) E2 in aqueous humor were determined on days 1, 3, and 5 and aqueous : serum ratios were calculated. Results: Firocoxib penetrated the aqueous humor to a significantly greater extent than did flunixin meglumine at days 3 and 5. Aqueous : serum ratios were 3.59 ± 3.32 and 11.99 ± 4.62% for flunixin meglumine and firocoxib, respectively. Ocular PGE2 concentrations showed no differences at any time point among study groups. Conclusions and Clinical Importance: Both flunixin meglumine and firocoxib penetrated into the aqueous humor of horses. This study suggests that orally administered firocoxib penetrates the aqueous humor better than orally administered flunixin meglumine at label dosages in the absence of ocular inflammation. Firocoxib should be considered for the treatment of inflammatory ophthalmic lesions in horses at risk for the development of adverse effects associated with nonselective NSAID administration.
Reservoir management to balance ecosystem and human needs: Incorporating the paradigm of the ecological flow regime

[1] The history of environmental flow analysis shows a shift from an emphasis on a flat line minimum flow requirement to the development of a holistic, regime-based, approach to flow management. The ecological flow regime determines environmental flow by embracing the multitude of species within an ecosystem rather than emphasizing a single species. Moreover, this paradigm recognizes that flow magnitude, duration, frequency, timing, and predictability must be incorporated into any flow management strategy. In this study, the ecological flow regime paradigm is used to establish such comprehensive and complex management targets for operating a reservoir to satisfy a downstream aquatic ecosystem. The new paradigm incorporates the intermediate disturbance hypothesis, which holds that ecosystems are healthier under disturbances that are neither too small nor too large. The nondominated sorting genetic algorithm is used to find the Pareto set of operating rules that provides decision makers with the optimal trade-off between human needs and ecological flow regime maintenance.
Attention Deficit/Hyperactivity Disorder and Substance Abuse

Patterns of association between attention deficit hyperactivity disorder (ADHD) and substance-use disorders are considered. Recent investigations have found that up to 50% of individuals with continuing ADHD symptoms have a substance-use disorder. ADHD appears to represent an independent risk factor for substance abuse. We review clinical challenges posed by the diagnosis of ADHD in substance-abusing populations. Nicotine dependence is also substantially more common among adults with ADHD (40%) than in the general population (26%). While several classes of substances of abuse may ameliorate various symptoms of ADHD, individuals with ADHD may also be vulnerable to substance use because of poor judgment or impulsive behavior in social settings. Evidence is reviewed from genetic studies examining the role of the dopamine D2 (DRD2) gene in the etiology of ADHD. The presence of ADHD may affect the course of adolescent substance abuse in several ways: predicting earlier age of onset, longer duration of substance-use disorder, and progression of alcohol abuse to another drug-use disorder. Individuals with ADHD have been noted to have a shorter interval between the onsets of drug abuse and drug dependence. Such individuals are also at greater risk for treatment failure, as their disruptive behaviors interfere with treatment access and response. Lastly, we review advances in pharmacotherapeutic agents used for treating ADHD and consider the impact of these interventions on comorbid substance-use disorders. We suggest promising areas of focus for clinical research trials targeting the subpopulation of substance abusers with concurrent ADHD.
University Student Perceptions of Seasonal and Local Foods

Abstract This study examined how university students conceptualize “seasonal” and “local” in relation to food. Because starting college often represents the first time many people assume primary responsibility for their meals, food beliefs of students are particularly relevant. A one-page written questionnaire was developed, pretested, and used to survey 166 undergraduate students from a nutrition and an economics class at one university. Students were asked to describe the concepts of “seasonal” and “local” foods and to name “seasonal” and “local” foods. Three-fourths of the students had heard the terms “seasonal” and “local,” but only about one-fourth reported using the terms themselves. A multitude of meanings were attached to the concepts of “seasonal” and “local” foods. Meanings having to do with food availability or production were most common for the seasonal food concept. Fewer meanings were identified for the concept of local foods; most commonly, those having to do with local foods had to do with where food is produced. Virtually all students could name “seasonal” and “local” foods. Nutrition students were more familiar with these terms than economics students. These results suggest that assessing and understanding how people define concepts such as “seasonal” and “local” may be beneficial in developing and implementing effective food and nutrition education.
Building Community: The Neighborhood Context of Social Organization

This study explores how neighborhood context influences participation in local social organization through a multilevel-spatial analysis of residents in Chicago neighborhoods. We construct a typology of community participation based on two dimensions: instrumental vs. expressive motivations for participation and formal vs. informal modes of participation. Both instrumental and expressive participation are generally higher in more disadvantaged neighborhoods. However, the association is nonlinear for instrumental organization, such that beyond a certain threshold, additional increases in disadvantage are associated with diminishing rates of participation. Rates of instrumental participation are also higher in neighborhoods where residents perceive more disorder. Rates of expressive participation are higher in more stable neighborhoods. These findings suggest that theories of urban poverty and social need are more applicable to instrumental forms of social organization, whereas the systemic perspective is more applicable to expressive forms. Finally, most forms of participation are related to the characteristics of both the immediate neighborhood and surrounding geographic areas.
Temperature gradients during cooling and freezing in the human brain.

Abstract Instrumentation has been devised which makes it possible to cool or freeze a controlled area within the human brain. Cooling, for purposes of physiological inhibition, and freezing for cryogenic production of intracerebral lesions are widely employed for various types of brain surgery. This report describes temperature gradients within the human brain during cooling and freezing.
Discount cosmetic surgery: industry trends and strategies for success.

Discount cosmetic surgery is a topic of interest to plastic surgeons. To understand this trend and its effects on plastic surgeons, it is necessary to review the economics of cosmetic surgery, plastic surgery's practice environment, and the broader business principles of service industries. Recent work looked at the economics of the plastic surgery market. This analysis demonstrated that increased local density of plastic surgeons was associated with lower adjusted fees for cosmetic procedures. A survey of plastic surgeons about their practice environment revealed that 93 percent categorized the majority of their patients as very or moderately price-sensitive. Fully 98 percent described their business climate as very or moderately competitive and most plastic surgeons thought they lost a sizable number of cosmetic patients within the last year for reasons of price.A standard industry analysis, when applied to cosmetic surgery, reveals the following: an increased number of surgeons leads to lower fees (reducing their bargaining power as suppliers), patients are price-sensitive (increasing their bargaining power as buyers), and there are few barriers to entry among providers (allowing potential new entrants into the market). Such a situation is conducive to discounting taking hold-and even becoming the industry norm. In this environment, business strategy dictates there are three protocols for success: discounting, differentiation, and focus. Discounting joins the trend toward cutting fees. Success comes from increasing volume and efficiency and thus preserving profits. Differentiation creates an industrywide perception of uniqueness; this requires broadly positioning plastic surgeons as holders of a distinct brand identity separate from other "cosmetic surgeons." The final strategy is to focus on a particular buyer group to develop a market niche, such as establishing a "Park Avenue" practice catering to patients who demand a prestigious surgeon, although this is likely a small segment of the overall patient population. Plastic surgeons that buck the trend toward discount cosmetic surgery must take concrete and potentially costly steps to implement a plausible strategy for distinguishing their practices within the crowded cosmetic surgery market.
Can a perceptual peer deviance measure accurately measure a peer's self-reported deviance?

Abstract Purpose Social learning theory and self-control theory differ considerably in their interpretation of what qualifies as a “valid” measure of peer deviance. While the two theories are epistemological opposites in regards to how to operationalize the peer deviance construct, their differences are reconcilable. The current study seeks to identify a set of perceptual items that accurately measure a peer's self-reported deviance. This measure would satisfy the preferences of both learning and control theories because the measure is perceptual but also accurate. Methods Using data from 2,154 individuals in friendship pairs where each respondent perceived 26 peer behaviors and self-reported the same behaviors, regression, item-response, and mean difference tests are used to perform item deletion. Results Five perceptual peer deviance items are identified which are not significantly different from the peer's self-reported deviance. When scaled together and inserted into multivariate regressions, however, the perceptual peer deviance items are still related to the respondent's deviance more strongly than the peer's self-reported deviance. Conclusions We are unable to identify a set of perceptual items that is interchangeable with a peer's self-reported deviance. Accordingly, the theoretical debate between Akers and Gottfredson and Hirschi regarding the measurement of differential association may not be empirically resolvable.
Influence of chicken and human lipoproteins on steroidogenesis in granulosa cells of the domestic fowl (Gallus domesticus).

Abstract When freshly dispersed granulosa cells from the largest preovulatory follicle were incubated in the presence of very low density (VLDL), low density (LDL), or high density (HDL) lipoproteins isolated from sera of laying hens, production of both basal and LH-stimulated progresterone was significantly increased in a dose-related manner. VLDL, the principal transporter of cholesterol to the ovum, appeared to be the most efficacious. A highly significant potentiation of the steroidogenic action of 8-bromo-cyclic adenosine monophosphate and forskolin was also observed. Human LDL, and especially HDL, caused significant stimulation of progesterone production by these cells. It is suggested that the release of cholesterol from lipoproteins taken up by granulosa cells raises the precursor pool for steroidogenesis. This mechanism is further enhanced by a cyclic AMP-mediated mechanism.
How sensitive is physician performance to alternative compensation schedules? Evidence from a large network of primary care clinics

Despite its centrality for the provision of health care, physician compensation remains understudied, and existing studies either fail to control for time trends, cover small samples from highly particular settings, or examine empirically negligible changes in reward levels. Using a four-year sample of 59 physicians and 1.1 million encounters, we study how physicians at a network of primary care clinics responded when their salaried compensation plan was replaced with a lower salary plus substantial piece rates for encounters and select procedures. Although patient characteristics remained unchanged, physicians increased encounters by 11 to 61%, both by increasing encounters per day and days worked at the network, and increased procedures to the maximum reimbursable level.
Evolution of photosynthesis and oxygen evolution: Implications from the structural comparison of Photosystems I and II

Two large membrane protein complexes, Photosystem I and II (PS I and PS II), perform the first step in the conversion of the light energy from the sun into chemical energy: the light-induced transmembrane charge separation. They function in series; PS II provides the strong positive redox potential for water oxidation, while PS I generates a strong negative redox potential, which makes it able to reduce ferredoxin and deliver the electrons for the reduction of hydrogen in the form of NADPH. The structural comparison of PS I and PS II sheds light on the evolution of oxygenic photosynthesis. Both Photosystems show similarities in their core structure, indicating that they have been derived from a common ancestor. Striking differences in the arrangement and coordination of cofactors and in their protein environment, however, may contain the secret to the functional differences between the Photosystems. In this article, we address how the oxygen-evolving complex may have developed, and the main similarities and differences in the electron carriers and the organization of the antenna systems of these two complexes.
Improved frequency regulation in mini-grids with high wind contribution using online genetic algorithm for PID tuning

Mini-grids with high wind contribution tend to be relatively more dynamic and less stable than wind integration in large interconnected grids. This instability is primarily due to frequency fluctuations introduced from highly variable wind generation, multiple single-phase distribution branches with highly unbalanced single-phase loads, large pseudo-instantaneous changes in load, over compensation of reactive power, and lower machine inertias providing less damping. The objective of this research is to investigate the use of a genetic algorithm (GA) based proportional integral derivative (PID) diesel speed controller to improve frequency regulation in standalone high contribution wind-diesel mini-grid systems. A dynamic model of a standalone high contribution wind-diesel system was developed to study frequency regulation under variable wind and load conditions. The results using GA-based PID diesel speed control demonstrate improved frequency regulation as compared to standard diesel speed controls.
Cytogenetic aspects of adult primary myelodysplastic syndromes : Clinical implications

Abstract Myelodysplastic syndrome (MDS) is a heterogeneous disease from the clinical, biological and morphological point of view. The pathogenesis of MDS is not well established and it appears to occur complex changes in the stem cell biology. Clonal chromosomal aberrations are found in 30–50% of primary MDS and no specific cytogenetic abnormality has as yet been defined. The chromosomal abnormalities are predominantly characterized by partial/total chromosomal losses or chromosomal gains. These chromosomal abnormalities include mainly −5/del(5q), −7/del(7q), del(11q), del(12p), del(20q), −Y, and +8. The role of cytogenetic analysis in the diagnosis, prognosis, taking treatment decisions and follow up of patients with MDS has been clearly defined. Despite its difficulties in obtaining for analysis high quality metaphases conventional cytogenetics continues to be the basic technique for cytogenetic evaluation of a MDS patient. Other molecular cytogenetic methods have been shown to be complementary, without replacing the information obtained with this technique. Further investigations with both conventional and molecular cytogenetics in relation to clinical features as well as other molecular methods will undoubtedly contribute to improve understanding of the underlying genetic events responsible for the development and evolution of MDS leading to more accurate classification and management of MDS patients.
Fermions and associated bosons of one-dimensional model

The representation of the canonical commutation relations involved in the construction of boson operators from fermion operators according to the recipe of the neutrino theory of light is studied. Starting from a cyclic Fock-representation for the massless fermions the boson operators are reduced by the spectral projectors of two charge-operators and form an infinite direct sum of cyclic Fock-representations. Kronig's identity expressing the fermion kinetic energy in terms of the boson kinetic energy and the squares of the charge operators is verified as an identity for strictly selfadjoint operators. It provides the key to the solubility ofLuttinger's model. A simple sufficient condition is given for the unitary equivalence of the representations linked by the canonical transformation which diagonalizes the total Hamiltonian.
Transverse-Isotropic Elastic and Viscoelastic Solids

A set of invariants are presented for transverse-isotropic materials whose gradients produce strain fields, instead of deformation fields as is typically the case. Finite-strain theories for elastic and K-BKZ-type viscoelastic solids are derived. Shear-free and simple shearing deformations are employed to illustrate the constitutive theory.
New technology developments make passive laser/fiber alignment a reality

In this paper we report on the combination of a precision cleaved large spot laser and a silicon micromachined optical bench to achieve high coupling efficiencies by purely passive alignment. Coupling efficiencies of over 50% have been obtained by passively aligning precision cleaved large spot sized lasers to singlemode fiber on a silicon micromachined substrate. This is the highest known coupling figure reported for passive alignment. The packaging of semiconductor laser chips has always presented a range of technical problems due to the sub-micron tolerances required to obtain optimum coupling of the small laser spot size to the larger spot size of a singlemode fiber. Lasers have been developed that can ease these tolerances by matching the laser spot size to that of cleaved fiber. This is achieved by tapering the active layer to adiabatically expand the laser mode size. A method of controlling the physical size of laser diode chips to sub-micron accuracy has enabled these lasers to be bonded against substantial alignment features on a silicon micro-engineered optical bench which also includes a V-groove into which a cleaved single-mode optical fiber can be fixed. Results are also discussed for an alternative ferrule-based, non-hermetic laser packaging design which utilizes the relaxed alignment tolerances of the large spot lasers to give simple package assembly suitable for automation. Both of the packaging technologies discussed offer a viable route to obtaining the very low cost optoelectronic components required for fiber to the home networks.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Methyl 3,4-di-O-acetyl-2-deoxy-2(R)-[1h,3h-2,4-dioxo-1-pyrimidinyl]-2-fluoro-β-D-arabinopyranoside: Novel nucleoside analogues via condensation of gem-2,2-difluoro methyl glycosides with silylated heterocyclic bases.

Abstract Methyl 3,4-di-O-acetyl-2-deoxy-2,2-di fluoro-D- erythro -pentopyranoside(III) reacts, in the presence of boron trifluoride etherate, with the trimethylsilyl derivative of uracil to form a novel nucleoside analogue bearing tine heterocyclic moiety and fluorine at the 2-position.
Effect of lisinopril monotherapy on renal hemodynamics.

Nineteen essential hypertensive patients were entered into a protocol to assess the BP, humoral and renal effects of the angiotensin converting enzyme inhibitor, lisinopril (MK 521, 20 to 80 mg once daily), administered for 52 weeks. Specifically monitored prior to, and following 12 and 52 weeks of lisinopril monotherapy were plasma renin activity and plasma aldosterone, the clearances of creatinine, inulin and para-aminohippurate, and the 24hour urinary excretion of protein. BP was well controlled. Plasma renin activity was stimulated, and plasma aldosterone was suppressed throughout the entire protocol. In contrast to the reported short-term and long-term renal effects of enalapril, lisinopril (a lysine analog of enalapril) had no short-term effect on renal function: glomerular filtration rate, effective renal plasma flow, filtration fraction (FF), renal vascular resistance (RVR), and protein excretion were all unchanged. However, following long-term therapy, both FF and RVR were decreased. Lisinopril appears to convey no specific renal pharmacological benefit.
Optimal semijoin schedules for query processing in local distributed database systems

Semijoin strategies are a technique for query processing in distributed database systems. In the past, methodologies for constructing minimum communication-cost strategies for solving tree queries have been developed. These assume point-to-point communication and ignore local processing costs and the limited communication capacity of the system. In this paper, query processing in bus or loop systems is considered. The definition of strategy is extended to allow for broadcast mode of communication. We then address the problem of finding the minimum response-time schedule for executing a given strategy in an m-bus system taking into account local processing and system capacity. It is shown that the problem is computationally intractable for general tree queries, even in a 1-bus system, and for special classes of tree queries in an m-bus system. However, there is a polynomial-time algorithm for simple queries in a 1-bus system.
Mandatory Continuing Education for Clinical Laboratory Personnel.

Continuing education is imperative for clinical laboratory professionals because of continuous rapid changes in the field. The authors review the pros and cons of mandatory continuing education in current literature and present arguments for its adoption. By reference to recent well-designed studies that show continuing education alters professional practice they respond to the argument that continuing education has not been proven effective. A system for mandatory continuing education for laboratory professionals is proposed.