cssi/SciSciGPT-SciSciNet huggingface dataset:
Role of PTEN in butyrate-induced colon cancer cell growth arrest, apoptosis, and differentiation.

5084 HDAC inhibitors induce cell-cycle arrest in the G1 and/or G2 phase, apoptosis and/or differentiation in cancer cells and are showing promise as treatment for a variety of human cancers. Their precise mechanism of action however, has not been fully elucidated. We identified a significant upregulation of PTEN mRNA in a microarray database of Caco-2 colon carcinoma cells treated with the HDAC inhibitor, sodium butyrate. PTEN (phosphatase and tensin homologue deleted on chromosome 10) is a dual phosphatase, acting at both serine-threonine and tyrosine sites. PTEN inhibits the activation of Akt/protein kinase B by phosphatidylinositol 3,4,5-triphosphate, thus modulating a major pathway controlling cell proliferation and survival. This study, therefore, aimed to examine the role of PTEN in HDAC inhibitor-induced colon cell maturation. Consistent with the microarray data, we found that butyrate upregulated PTEN mRNA and protein expression in a dose- and time-dependent manner in Caco-2, HT-29, and HCT116 colon cancer cells. PTEN induction was first observed 48-72 hours following butyrate treatment suggesting its upregulation is an indirect effect of butyrate treatment. Upregulated PTEN expression in response to butyrate was also observed in Hela cells, indicating this effect was not specific to colon cancer cells. The structurally related HDAC inhibitor, valproic acid, also induced PTEN expression in colon cancer cells. To determine whether upregulation of PTEN is specific to butyrate induced differentiation or a consistent feature of intestinal cell differentiation, we examined its expression in the Caco-2 in vitro model of colon cell differentiation and along the crypt-villus axis in vivo. PTEN expression was increased during spontaneous differentiation of Caco-2 cells, and along the mouse small intestinal crypt to villus axis in vivo, indicating PTEN is consistently upregulated during intestinal cell differentiation. To directly determine the role of PTEN in butyrate-induced growth inhibition, differentiation and apoptosis in colon cancer cells, PTEN was inhibited using siRNA in colon cancer cells. Western blot analysis confirmed a >80% inhibition of PTEN protein expression following 72-120h exposure to small interfering RNA. Silencing of PTEN partially attenuated butyrate-induced growth inhibition and apoptosis in HCT116 cells, and butyrate-mediated induction of the differentiation marker, alkaline phosphatase activity, in Caco-2 cells. Screening of a panel of 30 colon cancer cell lines identified 2 cell lines, LIM2405 and KM12 that had no detectable PTEN expression, and PTEN was not induced by butyrate in these cell lines. Collectively, these results demonstrate that upregulation of PTEN plays a role in mediating butyrate-induced growth inhibition, apoptosis and differentiation in vitro.
The long and winding path to understanding kidney structure in amphioxus - a review.

The history of studies on amphioxus kidney morphology is reviewed with special attention to four zoologists who made important early contributions. In 1884, Hatschek described a single anterior nephridial tubule in larval and adult amphioxus. Subsequently, in 1890, Weiss and Boveri independently found multiple branchial nephridia (morphologically similar to Hatschek’s nephridium) associated with the pharyngeal gill slits. These initial discoveries set the stage for Goodrich to criticize Boveri repeatedly for the latter’s contention that amphioxus nephridia develop from mesoderm and are connected to neighboring coeloms throughout the life history. In the end, Boveri was almost certainly correct about amphioxus nephridia developing from mesoderm and at least partly right about the lumen of the nephridial tubules being connected to nearby coeloms—the openings are present during larval stages but are closed off later in development. The more detailed structure of amphioxus nephridial tubules was ultimately revealed by electron microscopy. The tubule epithelium includes specialized excretory cells (cyrtopodocytes), each characterized by a basal region similar to that of a vertebrate renal podocyte and an apical region bearing a flagellar/microvillar process reminiscent of an invertebrate protonephridium. At present, in spite of considerable progress toward understanding the development and structure of amphioxus nephridia, virtually nothing is yet known about how they function, and no consensus has been reached about their phylogenetic significance.
Use of Spring Plates in Fixation of Comminuted Posterior Wall Acetabular Fractures.

Objectives:Surgical management of comminuted posterior wall acetabular fractures with marginal fragments remains difficult. The purpose of this study was to evaluate the use of spring plates as adjunctive fixation in comminuted posterior wall acetabular fractures.Methods:A retrospective review of pa
Synthetic Optical Anisotropy via Plasmonic Resonant Tuning of Nanorod Orientation

We demonstrate tunable orientation of gold nanorods in colloidal suspensions via plasmonic resonant solitons. Wavelength-dependent polarizability and optical torque lead to synthetic anisotropic optical properties (birefringence and dichroism) of the nanorods along the soliton channel.
3D photonic structure for plug-and-play fiber to waveguide coupling

We show a 3D photonic structure for passive high alignment tolerance fiber to waveguide coupling. We measured a coupling efficiency of 2.5dB+/-0.4dB from fiber to a polymeric waveguide for fiber misalignments within a 17 μm diameter.
Revised declaration of Helsinki. Ethics is not just for ethicists.

Editor—Singer and Benatar's editorial on revisions of the Declaration of Helsinki proposes “capacity development,” defined as an increased number of professionals trained in ethics.1 Although this is indeed a step that needs to be taken, I cannot agree that it alone will advance the cause of ethical research, especially with the plans that the authors propose. The assumption that having more trained people will change the system satisfies a necessary but not sufficient criterion. The fact that there are more doctors in the developing world today than there were 20 years ago does not mean either that the practice of medicine is better or that health needs are addressed. It depends on what these people trained in ethics do, where they do it, how they sustain their efforts, and how they integrate their contributions within the overall health development of nations. The numbers and budgets presented in the proposal are simply arbitrary—they are not defended and so are difficult to evaluate. If $100m is available, what are the alternative pathways for investment for the developing world? If one considers all the health and staffing needs then the need for ethics training may not be the most important: community health workers, trained birth attendants, and others may be higher on the list. Another major issue is where the money goes. Implicit in the editorial is that the money will have to go to training centres in the West. This means that 90% of the money is not going to the developing world—a feature of “aid” well known to those in the South. The editorial severely underplays the role of other stakeholders. The importance of roles for professionals from a wide variety of disciplines, of decision makers, of community leaders, and of business leaders in shaping the practice of ethics in the South needs to be recognised. A “global alliance for health ethics” and the proposed influence on the World Bank and World Trade Organisation are only distant visions. Is this the most effective or most efficient way to achieve that vision? Activists, lobbyists, and social scientists will beg to differ. As long as ethics is viewed as something that is only for ethicists, or for those who have only been trained, it will never have the profound influence we all hope that it will have in both the developing and developed world.
Localized Excitations in Discrete Hamiltonian Systems

The modification of soliton properties (e. g. of kinks and breathers) in discrete systems has been studied over a rather long period of time1. Recently Takeno2 has discussed a new type of nonlinear localized excitations (NLE) in one-dimensional discrete lattices. Despite the fact that the existence of NLE was confirmed by computer simulations and approximate one-frequency solutions for the NLE could be found (Q l (t) = Q l (t + 2π/ω1), where Q l is the l-th particle displacement from the ground state position), the reason for the existence of the NLE remained unclear.
CHAPTER 19 – ADVERSE EFFECTS OF VIRAL VACCINES

Publisher Summary This chapter discusses the adverse effects of viral vaccines. A number of other adverse effects of vaccines have been described in association with both natural viral disease as well as following the use of certain viral vaccines. The occurrence of joint manifestations and neuropathy has been observed in association with natural rubella infection, and to a lesser extent with several rubella vaccines. Following the use of rubeola vaccine, thrombocytopenia has been observed in some cases severe enough to be associated with purpura. Of greater clinical significance have been recent reports of the association of subacute sclerosing panencephalitis (SSPE) in association with rubeola vaccine. The number of cases of SSPE associated with natural rubeola virus disease has been decreasing and an upward trend has been observed in a number of cases associated with rubeola vaccine. Another adverse effect of many vaccines has been the encephalitis, which is seen as a postvaccinal event.
Moving Forward: A Research Agenda for SHAPE America.

The research arm of SHAPE America – Society of Health and Physical Educators (and before that the American Alliance for Health, Physical Education, Recreation and Dance [AAHPERD]) has a long histor...
Analyses and measurements of gamma-ray heating in the Demonstration Benchmark plutonium-fueled critical assembly

Absolute gamma-ray heating was investigated in Assembly 2 of the Zero Power Plutonium Reactor (during operation in support of the Demonstration Reactor Benchmark critical program). Three loading co...
Early Tumor and Nodal Response in Patients with Locally Advanced Non-Small Cell Lung Carcinoma Predict for Oncologic Outcomes in Patients Treated with Concurrent Proton Therapy and Chemotherapy

Purpose There are no established imaging biomarkers that predict response during chemoradiation for patients with locally advanced non-small cell lung carcinoma. At our institution, proton therapy (PT) patients undergo repeat computed tomography (CT) simulations twice during radiation. We hypothesized that tumor regression measured on these scans would separate early and late responders and that early response would translate into better outcomes. Methods and Materials Patients underwent CT simulations before starting PT (CT0) and between weeks 1 to 3 (CT1) and weeks 4 to 7 (CT2) of PT. Primary tumor volume (TVR) and nodal volume (NVR) reduction were calculated at CT1 and CT2. Based on recursive partitioning analysis, early response at CT1 and CT2 was defined as ≥20% and ≥40%, respectively. Locoregional and overall progression-free survival (PFS), distant metastasis–free survival, and overall survival by response status were measured using Kaplan–Meier analysis. Results Ninety-seven patients with locally advanced non-small cell lung carcinoma underwent definitive PT to a median dose of 66.6 Gy with concurrent chemotherapy. Median TVR and NVR at CT1 were 19% (0-79%) and 19% (0-75%), respectively. At CT2, they were 33% (2-98%) and 35% (0-89%), respectively. With a median follow-up of 25 months, the median overall survival and PFS for the entire cohort was 24.9 and 13.2 months, respectively. Compared with patients with TVR and NVR Conclusions Significantly improved outcomes in patients with early responses to therapy, as measured by TVR and NVR, were seen. Further study is warranted to determine whether treatment intensification will improve outcomes in slow-responding patients.
Activating Standardization Bodies Around Medical Apps

The accuracy and safety of the information provided by medical and health related apps are of concern to medical and healthcare professionals. In the United States medical and certain health related devices are regulated for safety and accuracy by the U.S. Food and Drug Administration (FDA). Wireless devices, like smart phones, are regulated by the US Federal Communications Commission (FCC). Until now, the approval process was limited to complete devices. An FDA regulated medical device can contain software but the regulatory approval process involves the complete device, not each of its components separately. But what about apps? Apps are software which may turn an otherwise non-medical or non-healthcare device into a medical or healthcare device. Do you regulate the software? It only has value when running on a device. Should you regulate the combination of device and software? It seems that every day a new smart phone is introduced and new apps become available. Do you have to test every combination? This paper will discuss the approach being taken in the United States by the government as well as by private industry.
Sequential extraction of the phosphate and collagen fractions of small bone samples for the analysis of multiple isotope systems (δ18OPO4, δ13C, δ15N)

RATIONALE Stable isotope analyses are used on precious archeological and paleontological materials despite their destructive nature, because the information gained by these methods on, for example, feeding habits, migration and health of individuals cannot otherwise be obtained. We approached this issue by devising a new sequential extraction scheme aimed at producing multiple (O, C, N) isotope proxies from small amounts of sample. METHODS The new extraction scheme includes dissolution of the bone in dilute HNO3 followed by separate treatments of the collagenous and phosphate fractions. The collagen fraction is treated further adopting the methods presented in the literature for collagen extraction, modified to accommodate small sample sizes. The phosphate-containing fraction is purified from organic contaminants by H2 O2 and the phosphate is precipitated as Ag3 PO4 following methods presented in the literature. The use of HF as demineralization agent is also tested. RESULTS A starting amount of ca 2 mg produced enough material for meaurement by isotope ratio mass spectrometry of the collagen C and N isotope compositions and bone phosphate O isotope composition. We show that the isotopic data obtained from the sequential extraction scheme are comparable with the isotopic composition measured following conventional methodologies that are usually based on 100-500 mg sample sizes. CONCLUSIONS The new sequential extraction scheme combines the preparation for stable isotope analysis of bone mineral and organic phases, thus minimizing the amounts of sample needed and damage caused on a sample piece. The method may allow analysis of skeletal samples previously excluded from isotope analysis due to material limitations.
Evaluation Of Computed Tomographic Units

A method is presented to systematize the selection of a CT Scanner. The method consist of four parts: initial contact with vendor, paper analysis of the machine, physical survey of the machine, and final analysis. The paper discusses the details of the method and presents the results of the physical surveys of about twenty-five scanners.
Research Methods and Applications for Student Affairs

Through its organization and content, this book may serve as a course text as well as a valuable resource for student affairs professionals whose skills in assessment and research are essential in ...
Bayesian networks: regenerative Gibbs samplings

Gibbs samplings is a Markov Chain Monte Carlo technique for estimating conditional probabilities in Bayesian networks. A major problem of Gibbs sampling is the dependency of the generated chain of ...
WE-EF-204-02: Murine Model Systems for Co-Clinical Trials

As molecular biology breakthroughs in understanding cancers and other diseases, hundreds of new drugs wait testing. In the last decade, mouse models have been evolved to better mimic human diseases genetically and biologically. These reliable mouse models allow us to determine which genetic elements, pathways and mutations impact on therapy. The co-clinical trial strategy is to conduct a human clinical trial for a therapeutic drug and test it in mouse models at the same time. This strategy has the potential to accelerate the drug testing process and identify the patient population that will respond to the drug. Imaging plays an important role in co-clinical trials. In this symposium, four speakers will discuss advancements and issues in pre-clinical imaging, murine models, imaging hardware and software, and funding opportunities in co-clinical trials. Learning Objectives: 1. Multi-modality pre-clinical imaging hardware and software, and new technologies (e.g., hyperpolarized MRI) 2. Selection of animal models from physiological and genetic perspectives with examples in colon, pancreatic and lung cancers 3. NCI funding opportunities
Further Properties of the Representations

In this chapter we derive several important properties of the representations we constructed in the previous chapter. Throughout the chapter, \(\mathfrak{g} = \mathfrak{k}_{\mathbb{C}}\) denotes a complex semisimple Lie algebra, \(\mathfrak{h} = \mathfrak{t}_{\mathbb{C}}\) denotes a fixed Cartan subalgebra of \(\mathfrak{g},\) and R denotes the set of roots for \(\mathfrak{g}\) relative to \(\mathfrak{h}.\)
Uniformity of ventilation in the newborn infant: direct assessment of the arterial-alveolar N2 difference.

The arterial-alveolar pressure difference for nitrogen (aADN2) was directly measured during the first 4 hours after birth in nine clinically normal infants. Transient gross elevations of the aADN2 were seen in most babies, indicating early maldistribution of ventilation. However, by 4 hours of age, the aADN2 had subsided to 6 ± 22 mm Hg, a value characteristic of normal older infants and children. These findings are in conflict with previous indirect assessments of aADN2 by analyses of urinary nitrogen pressure. It is concluded that normal infants achieve excellent uniformity of pulmonary distribution of gas and blood soon after birth.
It's About Time An Undergraduate Honors Course on the Topic of Time

This paper presents information concerning a specific undergraduate honors course on the interdisciplinary topic of time. True to the cross-cutting nature of time, the course was both led by and primarily taught by two professors from the distinctly different disciplines of information systems and psychology, respectively. It was offered as a special topic honors course in the Burnett Honors College at the University of Central Florida whose rubric ensured that enrollment was limited to a maximum of twenty undergraduate, honors students only. Additionally, selected auditors were allowed to attend specific, special events. The ceiling on enrollment proved critical since it allowed for a broad, discussion-based exploration of time, led on a number of occasions by specialist guest lecturers drawn from the arts, the sciences, and other speakers from well beyond the traditional confines of academe. There was a high demand for, and an excellent reception of, the course as offered. Due to the external constraints of the two professors involved, it proved to be a unique offering. However, the following description is provided for use by other teachers and professors who might wish to peruse and adopt the basic structure and/or some of the content that was collected and created.
Bachelors, Manhood, and the Novel, 1850-1925

Introduction 1. Trouble in paradise: bachelors and bourgeois domesticity: 2. Sickness and the single man: sympathy, vicariousness, and the bachelor invalid in James and Bronte 3. 'An artist and a bachelor': Henry James, discipleship, and mastering the life of art 4. 'A way of looking on': male feminism and male fetishism in Conrad's Under Western Eyes 5. 'The necessary melancholy of bachelors': melancholy, manhood and modernist narrative in Conrad, Ford and Fitzgerald Bibliography.
Seismic Response of Cohesive Marine Soils

A nonlinear hysteretic soil model and an energy transmitting boundary are utilized in the method. The model allows a failure criterion to be incorporated and accounts for stiffness degradation under repeated loading. The energy transmitting boundary provides the means for representation of typical marine soil profiles without the need for specifying rigid bedrock at a finite depth. Results showing acceleration and displacement time histories and response spectra for several different marine soil profiles and different levels of shaking are presented. Cases where the shear modulus increases linearly with depth as well as "crust" type shear strength profiles are studied. The analyses show that correct representation of soil properties both above and below the point of ground motion input is a major factor in controlling the nature of seismic response. (ASCE)
Efficient routing and wavelength assignment algorithm minimizes wavelength fragmentations in WDM mesh networks

This paper proposes a novel routing and wavelength assignment algorithm that minimizes wavelength fragmentations in WDM mesh networks. Our evaluation shows that more number of provisionable paths increase by using the proposed algorithm.
Appendectomy incidental to postpartum sterilization procedures

Abstract Despite many studies advocating incidental appendectomy, many physicians continue to fear intra-abdominal infection. Patients who have previously had cesarean sections or postpartum sterilization procedures without appendectomy may later present with appendicitis or symptoms which require that appendicitis be included in the differential diagnosis. The morbidity with and without appendectomy following cesarean section, cesarean tubal ligation, cesarean hysterectomy, postpartum tubal ligation, and postpartum hysterectomy is presented. No significant difference in morbidity with or without appendectomy was found in this series. Indications for routine performance of incidental appendectomy are presented.
Hemoglobin F-Caltech: alpha 2 G gamma 2 120Lys replaced by Gln.

During cord blood screening, a fast moving γ-chain variant was detected in an infant of French-Swedish-Hispanic extraction. In this variant, lysine at residue 120(GH 3) in the Gγ chain is replaced by glutamine. Because the AγT chain is also present, this girl has four types of γ chain. The percentage is unusually high for a γ-chain variant.
Simulation from a known Cox MSM using standard parametric models for the g‐formula

It is routinely argued that, unlike standard regression-based estimates, inverse probability weighted (IPW) estimates of the parameters of a correctly specified Cox marginal structural model (MSM) may remain unbiased in the presence of a time-varying confounder affected by prior treatment. Previously proposed methods for simulating from a known Cox MSM lack knowledge of the law of the observed outcome conditional on the measured past. While unbiased IPW estimation does not require this knowledge, standard regression-based estimates rely on correct specification of this law. Thus, in typical high-dimensional settings, such simulation methods cannot isolate bias due to complex time-varying confounding as it may be conflated with bias due to misspecification of the outcome regression model. In this paper, we describe an approach to Cox MSM data generation that allows for a comparison of the bias of IPW estimates versus that of standard regression-based estimates in the complete absence of model misspecification. This approach involves simulating data from a standard parametrization of the likelihood and solving for the underlying Cox MSM. We prove that solutions exist and computations are tractable under many data generating mechanisms. We show analytically and confirm in simulations that, in the absence of model misspecification, the bias of standard regression-based estimates for the parameters of a Cox MSM is indeed a function of the coefficients in observed data models quantifying the presence of a time-varying confounder affected by prior treatment. We discuss limitations of this approach including that implied by the “g-null paradox”.
SEEDS: a software engineer's energy-optimization decision support framework

Reducing the energy usage of software is becoming more important in many environments, in particular, battery-powered mobile devices, embedded systems and data centers. Recent empirical studies indicate that software engineers can support the goal of reducing energy usage by making design and implementation decisions in ways that take into consideration how such decisions impact the energy usage of an application. However, the large number of possible choices and the lack of feedback and information available to software engineers necessitates some form of automated decision-making support. This paper describes the first known automated support for systematically optimizing the energy usage of applications by making code-level changes. It is effective at reducing energy usage while freeing developers from needing to deal with the low-level, tedious tasks of applying changes and monitoring the resulting impacts to the energy usage of their application. We present a general framework, SEEDS, as well as an instantiation of the framework that automatically optimizes Java applications by selecting the most energy-efficient library implementations for Java's Collections API. Our empirical evaluation of the framework and instantiation show that it is possible to improve the energy usage of an application in a fully automated manner for a reasonable cost.
POLICING PHYSICIANS: PRACTITIONER FRAUD AND ABUSE IN A GOVERNMENT MEDICAL PROGRAM*

Fraud and abuse by physicians participating in government medical programs incurs physical and fiscal costs to society. This paper focuses on the enforcement process by which such behavior is detected, defined, and sanctioned. Interviews with officials in California's Medi-Cal program reveal the special problems associated with the influence of physicians' professional power on the enforcement process. In addition, the occupational status of physicians protects them against damaging interpretations of acts that may be in violation of the law.
Characterization of Particulate Structures

Abstract A number of techniques for studying particulate structure are described. These techniques involve a combination of electronic particle sizing, gas adsorption surface area measurements and scanning electron microscopy (CC, BET and SEM). Data are presented to show the change in particulate properties during milling, classifying, firing and surface treatments of a variety of materials which include fluorescent powders, alumina, silica, cobalt oxide and titanium dioxide powders. Each of the techniques utilized is described in detail with examples of how these tools may be employed in the characterization of particulates. The presence of agglomerate structures in certain powders is shown by employing in unison all three of the above methods. Each of the separate methods by itself is incapable of unambiguously characterizing such structure. At least two and preferably three are required for differentiating primary particles, agglomerates and aggregates.
Further Development of the k-? (Enstrophy) Turbulence Closure Model

The k‐‡ model is extended to the study of two-dimensional and three-dimensional separated external e ows where Morkovin’ s hypothesis is expected to hold. The resulting model is free of damping and wall functions and is coordinate independent. Further, all modeled correlations are tensorially consistent and Galilean invariant. Applications include a variety of separated e ows over airfoils and a cylinder/offset e are juncture. Comparisons are made with other turbulence models and experiment. In general, good agreement with experiment is indicated. The results demonstrate that it is possible to develop a two-equation turbulence model that is capable of predicting separated e ows without sacrie cing performance for free shear layers.
Topaz: A Mineralogical Review

Abstract Coveted by mineralogists and gemologists alike, November's birthstone has been named the featured mineral at the 1995 Tucson Gem & Mineral Show.
Computational analysis of muscular dystrophy sub-types using a novel integrative scheme

To construct biologically interpretable gene sets for muscular dystrophy (MD) sub-type classification, we propose a novel computational scheme to integrate protein-protein interaction (PPI) network, functional gene set information, and mRNA profiling data. The workflow of the proposed scheme includes the following three major steps: firstly, we apply an affinity propagation clustering (APC) approach to identify gene sub-networks associated with each MD sub-type, in which a new distance metric is proposed for APC to combine PPI network information and gene-gene co-expression relationship; secondly, we further incorporate functional gene set knowledge, which complements the physical PPI information, into our scheme for biomarker identification; finally, based on the constructed sub-networks and gene set features, we apply multiclass support vector machines (MSVMs) for MD sub-type classification, with which to highlight the biomarkers contributing to sub-type prediction. The experimental results show that our scheme can help identify sub-networks and gene sets that are more relevant to MD than those constructed by other conventional approaches. Moreover, our integrative strategy improves the prediction accuracy substantially, especially for those 'hard-to-classify' sub-types.
Revisiting bistability in the lysis/lysogeny circuit of bacteriophage lambda.

The lysis/lysogeny switch of bacteriophage lambda serves as a paradigm for binary cell fate decision, long-term maintenance of cellular state and stimulus-triggered switching between states. In the literature, the system is often referred to as “bistable.” However, it remains unclear whether this term provides an accurate description or is instead a misnomer. Here we address this question directly. We first quantify transcriptional regulation governing lysogenic maintenance using a single-cell fluorescence reporter. We then use the single-cell data to derive a stochastic theoretical model for the underlying regulatory network. We use the model to predict the steady states of the system and then validate these predictions experimentally. Specifically, a regime of bistability, and the resulting hysteretic behavior, are observed. Beyond the steady states, the theoretical model successfully predicts the kinetics of switching from lysogeny to lysis. Our results show how the physics-inspired concept of bistability can be reliably used to describe cellular phenotype, and how an experimentally-calibrated theoretical model can have accurate predictive power for cell-state switching.
The thermodynamics of solvent exchange.

A model for solvation in mixed solvents, which was developed for the free energy and preferential interaction [J. A. Schellman (1987), Biopolymers, Vol. 26, pp. 549–559; (1990), Biophysical Chemistry, Vol. 37, pp. 121–140; (1993), Biophysical Chemistry, Vol. 45, pp. 273–279], is extended in this paper to cover the thermal properties: enthalpy, entropy, and heat capacity. An important result is that the enthalpy of solvation H responds directly to the fraction of site occupation. This differs from the free energy Ḡ and preferential interaction Γ32, which are measures of the excess binding above a random distribution of solvent molecules. In other words, the enthalpy is governed by K while Ḡ and Γ32 are governed by (K − 1) where K is the equilibrium constant on a mole fraction scale [Schellman (1987)]. The solvation heat capacity Cp consists of two term: (1) the intrinsic heat capacity of species in solution with no change in composition, and (2) a term that accounts for the change in composition that accompanies solvent exchange. Binding to biological macromolecules is heterogeneous but experiementalists must use binding isotherms that assume the homogeneity of sites. Equations are developed for the interpretation of the experimental parameters (number of sites nexp, equilibrium constant Kexp, and enthalpy, Δhexp), when homogeneous formulas are applied to the heterogeneous case. It is shown that the experimental parameters for the occupation and enthalpy are simple functions of the moments of the distribution of equilibrium constants over the sites. In general, nexp is greater than the true number of sites and Kexp is greater than the average of the equilibrium constants. The free energy and preferential interaction can be fit to a homogenious formula, but the parameters of the curve are not easily represented in terms of the moments of distributions over the sites. The strengths and deficiencies of this type of thermodynamic model are discussed. © 1994 John Wiley & Sons, Inc.
Air cargo as an economic development engine: A note on opportunities and constraints

Abstract This note examines the role that air cargo plays in economic development and factors that condition its impact. After presenting basic empirical relationships between air cargo and both trade and gross domestic product per capita, we discuss three factors that can enhance air cargo's positive impact: air service liberalization, improving customs quality, and reducing corruption. We then model and assess the effects of these three factors on per capita net inward foreign investment and gross domestic product per capita in 63 countries around the world.
Cefotaxime use in pediatric infections

Cefotaxime has been used extensively in many pediatric centers in the United States for the past 10 or more years. Its main usage has been for the treatment of various serious bacterial infections in pediatric patients, primarily meningitis and sepsis. It has also been used to treat intraabdominal, urinary tract, soft tissue, bone, and joint infections. Although there has been a marked reduction in the incidence of invasive Haemophilus influenzae type b infections following the introduction of effective vaccines, cefotaxime remains very useful against the other common pathogens causing serious infections in pediatric patients. The increasing number of pneumococci resistant to penicillin and third-generation cephalosporins has created a new challenge for the management of serious pneumococcal infections. In many institutions, cephalosporins in general have been overused and abused, resulting in the emergence of resistant organisms and an increasing burden on resources. The judicious use of cefotaxime and other cephalosporins should be emphasized.
An Assessment Framework for the Development of Internet GIS

The popularity of Internet technology has brought about some fundamental changes in the field of GIS. Internet GIS is emerging as a new technology to access, process, and disseminate spatial information over the Internet. Internet GIS cover a much wider audience than the traditional GIS. This raises many issues that are distinct from traditional desktop GIS, such as easy access, web-compatible user interface, and file transfer security. I will first discuss the definition and features of Internet GIS. Two major approaches used in the Internet GIS development—server-side processing and client-side processing—are then described. These approaches are compared according to their performance, user interactivity, and other criteria. The server-side approach is appropriate to provide users easy access and inquiry of large databases, whereas the client-side Internet GIS offer better user interactions. The technology of Internet GIS is evolving rapidly. It is therefore important for the GIS community to monitor an...
Arylonium photoacid generators containing environmentally compatible aryloxyperfluoroalkanesulfonate groups

Photoacid generators (PAGs) producing environmentally benign 2-phenoxytetrafluoroethanesulfonate fluoroorganic sulfonic acids were synthesized. Synthesis and characterization of the new PAGs composed of 2-phenoxytetrafluoroethanesulfonate with diphenyliodonium or triphenylsulfonium units are described. Characteristics of the onium PAGs were evaluated and compared with perfluorobutanesulfonate (PFBS)-based onium PAGs. The newly synthesized compounds efficiently produced sulfonic acid photochemically upon exposure to selected radiation (254 nm, e-beam, and 13.4 nm wavelengths). The sulfonic acid generated from the new PAGs contains far fewer perfluorinated carbon atoms than those found in widely used perfluorooctanesulfonate (PFOS) PAGs and successfully catalyzed deprotection of the acid-labile tert-butoxycarbonyl, methyladamantyl ester, and tert-butyl ester groups present in model positive tone chemically amplified resists (CARs). Their influence on the lithographic performance of chemically amplified resi...
Weak Collision Effects in the Reaction CH3CO → CH3 + CO

Rate constants for the unimolecular decomposition of CH3CO have been obtained as a function of temperature (420 - 500 K) and helium density (3 - 18 · 1016 atom cm−3), conditions which are in the second order region of the fall-off curve. An Arrhenius expression for the low-pressure limit unimolecular rate constant was obtained from the results, k1±(He) = (6.7 ± 1.8) · 10−9 exp[(-6921 ± 126 K)/T] cm3 molecule−1 s−1. Using a Master Equation formalism to calculate values of k1, a set of the two energy parameters needed in the calculations, E± and ΔE)down (including its temperature dependence), was found that is within the range of expected values (including a temperature dependence in the case of ΔEdown), which, when incorporated into the Master Equation, provides calculated rate constants which agree well with the measured ones. They are E± = 65.3 ± 4.0 kJ mol−1 and ΔEdown = 65.6 + 0.271 T cm−1 (the latter, a parameterized expression, is valid only in the temperature range of this study). A transition state model for the unimolecular decomposition of CH3CO was produced which provides high-pressure limit rate constants for this reaction (k1±(CH3CO ± CH3 + CO) = 2.50 · 1013 exp(-8244 K/T) s−1 and k−1±(CH3 + CO ± CH3CO) = 7.64 · 10−13 exp(-3073 K/T) cm3 molecule−1 s−1) and k(E) values for solving the Master Equation for reaction conditions that are in the fall-off region. Fall-off behavior of k1 and k−1 reported by others for several different bath gases was reproduced within the uncertainty limits of the experimental results using the Master Equation formalism incorporating the transition state model, the energy parameter E± given above, and reasonable values for ΔEdown for the different bath gases used. This Master Equation formalism and transition state model should provide unimolecular rate constants for reaction (1, - 1) in the fall-off region for additional bath gases using reasonable estimates of ΔEdown (e. g., values obtained for this energy-transfer parameter for collisions between other polyatomic radicals and the bath gases of interest).
Characterization of genes encoding topoisomerase IV of Mycoplasma genitalium.

Abstract A type-II topoisomerase (Topo-IV) encoded by the parC and parE genes in Escherichia coli and Salmonella typhimurium is thought to be involvd in cell septation and in the decatenation of newly replicated chromosomes. We have identified parC and parE homologs in the pleomorphic, wall-less organism Mycoplasma genitalium. Since the mechanics of cell septation in conventional eubacterial species is believed to be mediated by cell-wall constituents, there is no clear understanding of what coordinates that process in wall-less species. The presence of par genes in this bacterium, which has the smallest genome of any free-living organism, suggests that Top-IV has been evolutionarily conserved because of an essential role in mediating cell division.
Passive constraint and new shape-change devices for heart failure

Abstract Lessons learned from ventricular remodeling procedures have shown that Laplace mechanics, whereby mural tension is related to ventricular diameter, may be beneficially applied to the left ventricle (LV). Recently developed devices, predicated on the Law of Laplace, are directed at interrupting the heart-failure cascade without removing functioning myocardium. The Acorn cardiac support device is a polyester-mesh jacket placed snugly around the heart to provide end-diastolic support and prevent LV dilation. The Myosplint device uses transmural tension members to bisect the dilated LV to create a bilobed LV with decreased mural tension in each cavity. Preclinical and early clinical data with both devices appears promising and may offer a new surgical alternative for patients with worsening heart failure. Copyright 2002, Elsevier Science (USA). All rights reserved.
Rats withdrawn from ethanol rapidly re-acquire membrane tolerance after resumption of ethanol feeding

Abstract The time course for the re-acquisition of membrane tolerance to the disordering effects of ethanol in vitro has been determined for liver microsomes obtained from chronically ethanol-fed rats that were withdrawn from ethanol for 2–4 days (during which tolerance is lost) followed by resumption of ethanol feeding. Naive rats require 28–35 days of chronic ethanol feeding to develop membrane tolerance. Microsomal membranes regain partial sensitivity to ethanol disordering after 2–3 days of withdrawal and regain the complete sensitivity observed in membranes from untreated control rats after 4 days of withdrawal. The period of ethanol re-feeding required for the reacquisition of membrane tolerance was dependent on the withdrawal period, with tolerance appearing sooner if the withdrawal period was shorter. The time course for the re-development of tolerance in previously tolerant animals was considerably faster (4–14 days) than in naive rats being administered the ethanol diet for the first time (35 days). Microsomes from rats that were withdrawn for 2 days (which retained partial tolerance) and then re-fed the ethanolic-diet required only 4 days to re-acquire membrane tolerance. Micrsomes from rats withdrawn 3 days required 8 days and those withdrawn 4 days required 15 days for full tolerance to re-develop. The same timecourse for the re-acquisition of membrane tolerance was observed in either intact microsomes or in liposomes prepared from extracted microsomal total phospholipids. Phosphatidylinositol (PI) has previously been reported to be responsible for conferring membrane tolerance to liver microsomes in ethanol-fed rats (Taraschi, T.F., Ellingson, J.S., Wu, A., Zimmerman, R. and Rubin, E. (1986) Proc. Natl. Acad. Sci. USA 83, 9398–9402). The time course for re-acquisition of membrane tolerance by liver microsomes following ethanol withdrawal and resumption of ethanol feeding correlated with the ability of PI to confer tolerance.
Computed tomography for internal derangements of the temporomandibular joint: a technical report.

Abstract A technique for maximizing the ability to perform direct sagittal CT scanning of the TMJ with the GE 8800 CT scanner gantry is described.
Reversible inhibition of cytochrome c oxidase by peroxynitrite proceeds through ascorbate-dependent generation of nitric oxide.

Reversible inhibition of cytochrome c oxidase (CcOX) by nitric oxide (NO•) has potential physiological roles in the regulation of mitochondrial respiration, redox signaling, and apoptosis. However peroxynitrite (ONOO–), an oxidant formed from the reaction of NO• and superoxide, appears mostly detrimental to cell function. This occurs both through direct oxidant reactions and by decreasing the availability of NO• for interacting with CcOX. When isolated CcOX respires with ascorbate as a reducing substrate, the conversion of ONOO– to NO• is observed. It is not known whether this can be ascribed to a direct interaction of the enzyme with ONOO–. In this investigation, the role of ascorbate in this system was examined using polarographic methods to measure NO• production and CcOX activity simultaneously in both the purified enzyme and isolated mitochondria. It was found that ascorbate alone accounts for >90% of the NO• yield from ONOO– in the presence or absence of purified CcOX in turnover. The yield of NO was CcOX-independent but was dependent on ascorbate and ONOO– concentrations and was not affected by metal chelators. Consistent with this, the interaction of ONOO– with CcOX in respiring isolated mitochondria only yielded NO• when ascorbate was also present in the incubation. These observations are discussed in the context of ONOO–/ascorbate reactivity and the interaction of CcOX with reactive nitrogen species.
Visual interfaces to computers : A systems-oriented first course in reliable control via imagery (visual interfaces)

We present the rationale, description, and critique of a first course in image computing that is not a traditional computer vision principles-and-tools course. "Visual Interfaces to Computers" is instead complementary to standard Computer Vision, User Interface, and Graphics courses; in fact, VI:CV::UI:G. It is organized by case studies of working visual systems that use camera input for data or control information in service of higher user goals, such as GUI control, user identification, or automobile steering. Many CV scientific principles and engineering tools are therefore taught, as well as those of psychophysics, AI, and EE, but taught selectively and always within the context of total system design. Course content is derived from conference and journal articles and Ph.D. theses, augmented with video tapes and real-time web site demos. Students do two homework assignments, one to design a "visual combination lock", and one to parse an image into English. They also do a final paper or project of their own choosing, often in teams of two, and often with surprisingly deep results. The course is assisted by a custom C-based tool kit, "XILite", a user-friendly (and comparatively bug-free) modification of Sun's X-windows Image Library for our lab's camera-equipped Sun workstations. The course has been offered twice to a wide audience with good reviews.
Reconstitution of Multidrug Resistance Efflux Pumps in Giant Liposomes

Multidrug resistance (MDR), a phenomenon in which cells become resistant to a number of drugs, is a growing obstacle for treatment of cancer and bacterial infections. A group of membrane transporters, known as MDR efflux pumps that bind to a wide range of foreign molecules and pump them out of the cell, are suspected to be the main contributors to MDR. P-glycoprotein (Pgp), which is the most well studied MDR efflux pump, has a critical role in the distribution of drugs in the body. As a result, screening the interactions between this protein and candidate drugs has recently become a required step in the FDA approval process. Biophysical characterization of Pgp and its transport activity may provide key information for the design and development of effective therapeutics. Giant unilamellar vesicles (GUV) are excellent models for natural cell membranes and present appealing platforms for biophysical studies of Pgp under well-defined conditions. Here, we reconstitute Pgp from Chinese hamster ovary B30 cells in giant unilamellar vesicles and investigate its ATPase activity as well as its transport activity.In this study, we applied small proteoliposomes with reconstituted Pgp for electroformation of Pgp-containing giant vesicles via our recently reported technique of hydrogel-assisted electroformation. These electroformed giant vesicles were characterized using fluorescence microscopy, immunohistochemistry, and ATPase assays. Fluorescence immunostaining confirmed the presence of Pgp in the membrane of GUVs. ATPase assay demonstrated that Pgp in GUVs retained its ATPase activity upon electroformtion. The specific ATPase activity of Pgp in GUVs was about 640 nmol/mg⋅min, comparable to that of this protein in small proteoliposomes, ∼660 nmol/mg⋅min. Moreover, we are investigating the transport activity of Pgp in these giant liposomes using fluorescence microscopy. The present study may provide valuable insight to the function of this MDR efflux pump.