cssi/SciSciGPT-SciSciNet huggingface dataset:
Differentiating between Models of Epothilone Binding to Microtubules Using Tubulin Mutagenesis, Cytotoxicity, and Molecular Modeling

Microtubule stabilizers are powerful antimitotic compounds and represent a proven cancer treatment strategy. Several classes of compounds in clinical use or trials, such as the taxanes and epothilones, bind to the same region of β-tubulin. Determining how these molecules interact with tubulin and stabilize microtubules is important both for understanding the mechanism of action and enhancing chemotherapeutic potential, for example, minimizing side effects, increasing solubility, and overcoming resistance. Structural studies using non-polymerized tubulin or stabilized polymers have produced different models of epothilone binding. In this study we used directed mutagenesis of the binding site on Saccharomyces cerevisiae β-tubulin to analyze interactions between epothilone B and its biologically relevant substrate, dynamic microtubules. Five engineered amino acid changes contributed to a 125-fold increase in epothilone B cytotoxicity independent of inherent microtubule stability. The mutagenesis of endogenous β-tubulin was done in otherwise isogenic strains. This facilitated the correlation of amino acid substitutions with altered cytotoxicity using molecular mechanics simulations. The results, which are based on the interaction between epothilone B and dynamic microtubules, most strongly support the binding mode determined by NMR spectroscopy-based studies. This work establishes a system for discriminating between potential binding modes and among various compounds and/or analogues using a sensitive biological activity-based readout.
Isolation and characterization of polyphenol oxidase isozymes of clingstone peach.

The polyphenol oxidase system in clingstone peach (Prunus persica) was investigated. Polyacrylamide disc-gel electrophoresis indicated four bands with polyphenol oxidase activity in extracts from acetone powder of clingstone peach. These four isozymes were then isolated from a buffer extract of peach acetone powder by cold acetone precipitation, followed by diethylaminoethyl cellulose column chromatography. All isozymes had different heat stabilities. At 55 C, polyphenol oxidases A, B, and D had half-lives of 5.4, 14.6, and 14.1 minutes, respectively. Polyphenol oxidase C was stable over a period of 50 minutes of incubation at 55 C, but had a half-life of 2.2 minutes at 76 C. None of the isozymes had monophenolase activity, and they varied in their specificity for several diphenols. The following values were found for polyphenol oxidases A, B, C, and D, respectively, with catechol as substrate: optimal pH: 6.8, 6.5, 7.2, and 7.0; Michaelis constant: 6.6, 4.2, 7.0, and 36 mm; Vmax/(E0): 4.95, 39.4, 2.16, and 80.0 (ΔA min−1 mg−1). Each isozyme showed a different amount of inhibition by NaHSO3, NaCl, NaCN, l-ascorbic acid, glutathione, ethylenediaminetetraacetate, and sodium diethyldithiocarbamate.
Prototype expert system to evaluate risk factor from hazardous substances

A hazardous material is a substance or material which has been determined by the US secretary of Transportation to be capable of posing an unreasonable risk to health, safety and property when transported or stored in commerce. These substances are stored at different industrial and government storage facilities in communities and are also transported across the nation using roads, waterways and airways. These dangerous materials range from toxic chemicals to nuclear waste. The exposure of these materials to air, water or ground may produce serious consequences to the health of all living beings and the surrounding environment. A community must know the 'risk factor' they are subjected to from storage and/or transportation of hazardous materials. This would allow the local emergency management agency to look at their existing 'level of preparedness' and consequently their vulnerability to a disaster. The dynamics of a situation involving hazardous substances may also evolve because of proposed change in traffic pattern and/or proposed change in storage facilities in the community. This may require frequent evaluation and monitoring of the 'risk factor' for the community. Documents are available from Federal Emergency Management Agency, US EPA, US Department of Transportation, State Emergency Management Agency, etc for risk and vulnerability assessment.
Coupling of large haptens to proteins and cell surfaces: Preparation of stable, optimally sensitized erhythrocytes for hapten-specific, hemolytic plaque assays

Abstract Procedures are described for converting tertiary-butyloxycarbonyl (Boc) hydrazides of large haptenic structures to reactive acyl azides and for using these intermediates in the preparation of a sereis of highly specific immunochemical reagents. The synthesis of the initial C-terminal Boc hydrazides, which are tripeptide derivatives, is described in a companion report (Inman et al. (1973) Immunochemistry10, 153). The converted azides react readily and specifically with amino groups in mildly alkaline, aqueous media and thereby provide an excellent means for covalently coupling haptens to immunogen carriers, proteins, or cells. The azide groups have relatively uniform reactivity due to an adjacent, common, glycylglycyl structure. Thus, it has been possible to prepare groups of immunochemical reagents, representing numerous specificities, by use of a single convenient procedure. Erythrocytes bound with large haptens by this method have functioned as highly stable and sensitive indicator cells in hapten-specific hemolytic plaque and hemagglutination assays. Conditions for preparing optimally sensitized erythrocytes for quantitative studies of hapten-specific plaque forming cells have been studies. Maximum numbers of plaque forming cells were detected when about 300,000 hapten molecules were bound per indicator erythrocyte. Plaque counts decreased progressively when indicator red cells had been conjugated with appreciably more or less than this amount of hapten. It has not been previously recognized that excessively hapten derivatization of erythrocytes regularly and profoundly impedes their susceptibility to specific immune lysis. Estimates have been made of the molecular circumstances which may explain this phenomenon. Its generaly implications for complement mediated cytolysis are discussed.
The Wages of Sickness: The Politics of Health Insurance in Progressive America

The Clinton administration's failed health care reform was not the first attempt to establish government-sponsored medical coverage in the United States. From 1915 to 1920, Progressive reformers led a spirited but ultimately unsuccessful crusade for compulsory health insurance in New York State. Beatrix Hoffman argues that this first health insurance campaign was a crucial moment in the creation of the American welfare state and health care system. Its defeat, she says, gave rise to an uneven and inegalitarian system of medical coverage and helped shape the limits of American social policy for the rest of the century. Hoffman examines each of the major combatants in the battle over compulsory health insurance. While physicians, employers, the insurance industry, and conservative politicians forged a uniquely powerful coalition in opposition to health insurance proposals, she shows, reformers' potential allies within women's organizations and the labor movement were bitterly divided. Against the backdrop of World War I and the Red Scare, opponents of reform denounced government-sponsored health insurance as ""un-American"" and, in the process, helped fashion a political culture that resists proposals for universal health care and a comprehensive welfare state even today. |Shows how the issues that prevented passage of the 1915-1920 campaign for compulsory health insurance in New York helped to shape a national political culture that continues to resist proposals for universal health care as ""un-American.
Simultaneous Donor Quenching and Acceptor Sensitization in Phosphorescence Studies of Triplet Energy Transfer: The Biacetyl—Benzil System

The simultaneous measurement of donor quenching and acceptor sensitization of a triplet‐energy‐transfer system as studied by phosphorescence techniques is presented. The quenching constant (KQ = 900±90 liter mole−1) is found to be different than the sensitization constant (KS = 390±40 liter mole−1). A general mechanism is proposed which accounts for these results, and also for cases where KS = KQ. Arguments are presented for the reevaluation of the triplet energies of benzil and anisil, and the newly appraised values are ET (benzil) = 19 000 cm−1 and ET (anisil) = 19 300 cm−1.
GIRL FRIENDS ARE BETTER: GENDER, FRIENDS, AND CRIME AMONG SCHOOL AND STREET YOUTH*

In recent years, popular media has drawn attention to “mean girls” and their negative treatment of others, particularly other females. But while the attention to girls' aggression and their mistreatment of their peers highlights understudied aspects of female behavior, it neglects the beneficial aspects of female friendship. We argue that compared to relationships with males, friendships with females provide more social control, fewer opportunities and less motivation for offending and may therefore discourage crime. Because an adolescent's gender likely influences the association between the gender of one's friends and crime, we anticipate that the association will be stronger for females than for males. The relationship is also likely affected by the context in which relationships originate; we expect that those that develop in less conventional contexts will have weaker effects on crime. We explore these hypotheses with a comparative analysis of effects of friendships on property crime in two samples of youth: those who live at home and attend school and those who are homeless and spend their days and nights on the street. Our findings support our hypotheses. The relationship between female-dominated friendship networks and property crime is negative and significant; however, this association is strongest for school females, weaker for school males and females who live on the street, and nonsignificant for homeless males.
Numerical and Experimental Investigations of Key Assumptions in Analytical Failure Models for Sheet Metal Forming

In this paper, the key assumptions in the M-K and effective stress ratio models are investigated for AISI 1018 steel specimens with a thickness of 0.78 mm using experimental and numerical data from Marciniak tests. The experimental procedure included Digital Imaging Correlation (DIC) to measure the major and minor in-plane strains. Strain components were obtained at points inside (i.e., the defect region) and adjacent (i.e., the safe regions) to the high strain concentrations for four different strain paths. In the numerical analysis, FEA simulations with Marc Mentat were performed with shell elements to investigate the four specimen geometries. The key assumptions of interest are the incremental major strain ratio from M-K model and the critical stress concentration factor from effective stress ratio model. Thus, the mechanics- and material-based failure phenomena in these two analytical models are examined in this paper to provide insight into the material behavior at failure.Copyright © 2012 by ASME
Microarthropod communities associated with biological soil crusts in the Colorado Plateau and Chihuahuan deserts

Biological soil crusts provide habitat for microarthropods of various trophic groups in arid systems, but the community composition and functional role of microarthropods in these unique systems are not well characterized for many desert locations. This study examined the microarthropod community, including mites, collembolans, and tardigrades, associated with early- and late-successional stage biological soil crusts at two locations, Colorado Plateau (southeastern Utah) and Chihuahuan Desert (southern New Mexico). Most microarthropod groups were more abundant in Colorado Plateau than Chihuahuan Desert, and tardigrades were more abundant near the surface (0–10 cm) than at depth (10–30 cm). Although the microarthropod community composition differed between Colorado Plateau and Chihuahuan Desert, Aphelacaridae, Cosmochthoniidae, Micropsammidae, Nanorchestidae, Stigmaeidae, and Tydeidae were families common to both locations, both crust stages and both depths. Most families present were microphytophagous, either strictly or as facultative predators. These findings are compatible with the microfloral nature of biological soil crusts dominated by lichen, moss, and cyanobacteria. Occasional predation of nematodes and protozoa grazing on the crust flora is likely. Other groups identified included zoophages, necrophages and macrophytophages. Proposed is a ‘core community’ of five strict microphytophages, four facultative predators, two zoophages, and one necrophage family.
Clinical Reasoning: A 69-year-old man with leukocytosis and hemorrhagic brain lesions

A 69-year-old man was admitted to our hospital with left upper quadrant pain, splenomegaly, acute renal failure, hyperuricemia, thrombocytopenia (platelet count 32,000/mm3), and leukocytosis (leukocyte count 88,000/mm3). His medical history was significant for prior diagnosis of myelodysplastic syndrome (MDS) by bone marrow biopsy at an outside institution treated with the hypomethylating chemotherapeutic agent decitabine, atrial fibrillation, cardiomyopathy, and complete pacemaker dependence. Neurologic examination upon admission was normal. The initial diagnostic considerations were tumor lysis syndrome from decitabine treatment vs transformation of MDS to acute myeloid leukemia (AML).
Preparation and alcohol oxidation studies of the ferrate(VI) ion, FeO42−

The preparation and properties of the very strong oxidizing ion, FeO42−, are reviewed. A shortened method for preparing samples of potassium ferrate(VI) which are usable in oxidation studies was developed. A study of the oxidation of various polyhydric alcohols by potassium ferrate(VI) indicates that the oxidation begins at terminal OH groups of the alcohols. During the course of the oxidation of some polyhydric alcohols by K2FeO4, polymerization of the alcohols is indicated.
Hopping Model for the Non-Debye Dielectric Response in Ionic Crystals

A model based on ion hopping in potential double-wells is proposed to explain the non-Debye dielectric response in solids. Relying on some assumptions, an attempt is made to remove the ''average'' nature of previous diffusion theories. This results in a distribution of activation energies, G(E), which decays exponentially on both sides of some given value E/sub o/. It is shown that the existence of a dielectric loss peak is a result of the decay of G(E) for E > E/sub 0/ the constant-phase-angle behavior above the loss peak is associated with the decay of G(E) for E < E/sub 0/, and G(E) can produce all the main features of the empirical Havriliak-Negami function. An interesting property of this G(E) is that it broadens with increasing temperature, consistent with many experimental observations. 18 refs., 3 figs.
Costeffectiveness of diagnostic tests.

Summary We review the principles underlying cost-effectiveness analysis of diagnostic tests and procedures. We use two clinical examples, diagnostic testing for early multiple sclerosis and for Helicobacter pylori to illustrate the methods of analysis and to show how the results can be useful for physicians or payers of health services in making decisions about provision and use of diagnostic services. Economic assessments of diagnostic tests are inherently more difficult than assessments of therapeutic interventions, mainly because of uncertainty about the relation between diagnosis and end results (outcomes) of care. Nonetheless, because of the increasing importance of diagnostic technology in medicine and healthcare, only with such assessments will the most value be gained from restricted medical resources.
Wavelength shift of the reflectivity peak of Bragg reflector structures

We discuss the wavelength for maximum reflectivity of a Bragg reflector that has both index and absorption modulation. We show there that the blue shift away from the Bragg wavelength can be no larger than that given by the wavelength of maximum coupling, which we derive analytically. For gratings with fewer layers, the blue shift will be smaller than this maximum value. In typical semiconductor Bragg reflectors, this shift may be as much as 32 nm.
Assessing Integrity of Intervention Implementation: Critical Factors and Future Directions

The series of articles on assessing integrity of intervention implementation advance the field by articulating three interrelated themes including that intervention integrity is a complex, multifaceted construct; integrity should be fostered and monitored in a proactive fashion; and multiple methods and respondents are necessary to comprehensively assess intervention integrity. These themes are discussed with a view towards important directions for future research in this area.
Modeling The Lifecycle Of Ebola Virus Under Biosafety Level 2 Conditions With Virus-like Particles Containing Tetracistronic Minigenomes

Ebola viruses cause severe hemorrhagic fevers in humans and non-human primates, with case fatality rates as high as 90%. There are no approved vaccines or specific treatments for the disease caused by these viruses, and work with infectious Ebola viruses is restricted to biosafety level 4 laboratories, significantly limiting the research on these viruses. Lifecycle modeling systems model the virus lifecycle under biosafety level 2 conditions; however, until recently such systems have been limited to either individual aspects of the virus lifecycle, or a single infectious cycle. Tetracistronic minigenomes, which consist of Ebola virus non-coding regions, a reporter gene, and three Ebola virus genes involved in morphogenesis, budding, and entry (VP40, GP1,2, and VP24), can be used to produce replication and transcription-competent virus-like particles (trVLPs) containing these minigenomes. These trVLPs can continuously infect cells expressing the Ebola virus proteins responsible for genome replication and transcription, allowing us to safely model multiple infectious cycles under biosafety level 2 conditions. Importantly, the viral components of this systems are solely derived from Ebola virus and not from other viruses (as is, for example, the case in systems using pseudotyped viruses), and VP40, GP1,2 and VP24 are not overexpressed in this system, making it ideally suited for studying morphogenesis, budding and entry, although other aspects of the virus lifecycle such as genome replication and transcription can also be modeled with this system. Therefore, the tetracistronic trVLP assay represents the most comprehensive lifecycle modeling system available for Ebola viruses, and has tremendous potential for use in investigating the biology of Ebola viruses in future. Here, we provide detailed information on the use of this system, as well as on expected results.
Kinetic and Mechanistic Study of the Displacement of η2-Coordinated Arenes from Cp*Re(CO)2(η2-C6H5R) (R = H, CH3, C(CH3)3): Evidence for a Dissociative Mechanism and Estimation of the Re−(η2-Arene) Bond Strength

The displacement of the arene molecule from Cp*Re(CO)2(η2-arene) (arene = benzene, toluene, tert-butylbenzene) by pyridine in heptane solution is studied. The rate constants for arene dissociation from the Re center are found to vary in the order Cp*(CO)2Re−(η2-toluene) < Cp*(CO)2Re−(η2-benzene) ≈ Cp*(CO)2Re−(η2-tert-butylbenzene) and are a function of the steric and electronic properties of the arene substituents. Activation parameters yield a lower limit of 19−21 kcal/mol for the Cp*(CO)2Re−(η2-arene) bond strength.
Rhesus monkey (Macaca mulatta) cool sensitivity measured by a signal detection method

Two rhesus monkeys were trained to detect cool stimuli (decrements in skin temperature from the adapted temperature) presented to the palm of the left hand after the skin had been preadapted to a 33°C temperature. The procedure was analogous to the signal detection “yes-no” method used with human observers. Receiver operating characteristic curves were generated by varying the a priori probability of stimulus oecurrence. The proportion of hits and of false alarms increased with increases in the a priori probability of stimulation. The points of isosensitivity of both subjects for cool intensities of 0.3°C, but not at greater intensities, yielded straight lines with slopes of approximately one when plotted on normal-normal coordinates. The values of the d’s detectability index decreased from 3.52 to 0.75 for one subject and from 2.81 1to 1.28 for the other as the stimulus intensity was decreased from 0.8° to 0.15° cooling from the adapting temperature. Cool thresholds for each subject of 0.19° and 0.12°C were computed from classical psychometric functions when threshold was defined as 50% hits at a 50% probability of stimulus occurrence. These thresholds are comparable to published reports of the cool threshold for the rhesus.
Valuing the Effect of Acidification Damages in the Adirondack Fishery: Reply

Our reply to Shaw's comment on our original paper (Mullen and Menz) considers three issues: (a) theoretical and empirical concerns raised by Shaw concerning our use of a zone demand travel cost model for estimating acidification damages, (b) whether Shaw's proposed utility-theoretic model represents an improved procedure for estimating acidification damages in the Adirondack fishery, and (c) other issues regarding valuation of environmental damages due to acid deposition. Shaw raises several issues concerning our use of the zone demand model to estimate acidification damages. The first is whether the equations we estimated were true demand equations so as to allow welfare measures consistent with the theory of consumer behavior. Shaw's concern about the validity of our demand equations is unwarranted. Our admittedly vague discussion of estimating a system of demand equations was not intended to suggest that ours was such a system. We did discuss the validity of symmetry constraints and their implications for calculating welfare losses via consumer surplus changes in both single-equation and systems approaches. We also pointed out that use of a single-equation approach is justified if marshallian consumer surplus is an acceptable approximation of the true welfare change (Hof and King).' Our decision to rely on "system" estimation-Zellner's seemingly unrelated regression technique (SUR)-was based solely on empirical consid
Airfoil self noise - Effect of scale

Key data from a comprehensive airfoil broadband self-noise study are reported. Attention here is restricted to two-dimensional sharp trailing-edge models. The models include seven NACA 0012 airfoil sections and five 'flat plate' sections with chordlengths ranging from 2.54 to 60.96 cm. Testing parameters include flow velocity, angle of attack to the flow, and boundary layer turbulence through natural transition and through tripping. Detailed aerodynamic measurements, of pertinence to the scaling problem of airfoil self-noise, were conducted in the near-wake of the trailing edges. Presented are mean and rms turbulent velocity profiles as well as boundary layer thicknesses and integral thickness parameters for a large range of conditions. The noise spectra of the self-noise sources were determined by the use of a cross-spectral technique. The spectra were normalized using the measured aerodynamic parameters in order to evaluate the most common scaling law now in use. An examination of the Reynolds number dependence of the overall self-noise levels has revealed a new and useful scaling result. This result appears to quantify the transition between turbulent-boundary-layer trailing edge noise and laminar-boundary-layer vortex shedding noise.
Serum Alkaline Phosphatase Reflects Post-Fontan Hemodynamics in Children

Although survivors of Fontan palliation for a single ventricle are known to have lower cardiac index than patients with two-ventricle surgical reconstructions, it is unclear whether two frequently observed sequelae, short stature and protein-losing enteropathy (PLE), have hemodynamic origins. A serum marker that reflects hemodynamic status would be a tremendous asset in the long-term management of children with these sequelae. The authors recently noted severely reduced total alkaline phosphatase (TALP) levels in two children with early-onset PLE after Fontan operations, both of whom had low cardiac output at cardiac catheterization. Catheter-based or surgical interventions that rapidly increased cardiac output in these two patients resulted not only in relief of PLE but also in a prompt TALP rise. To examine whether the apparent correlation of low TALP with impaired cardiac output also is seen in Fontan patients without PLE, this study retrospectively examined the TALP data from two other Fontan patients who underwent cardiac catheterization specifically to assess the potential benefit of vasodilator therapy. The TALP levels were abnormally low in both cases but increased after uptitration of angiotensin-converting enzyme inhibition. Serum TALP activity, an indicator of osteoblastic function particularly in preadolescence, may be a marker of low cardiac output after a Fontan operation.
Palmitic acid and initiation of mammary glyceride synthesis via phosphatidic acid

Abstract Palmityl-CoA was by far the preferred substrate for the initial acylation of l -α-glycerolphosphate by acyl transferase of bovine mammary microsomes. The rate of acylation of palmityl-CoA was eight to ten times the rate observed when myristyl, stearyl or oleyl-CoA was used. All of the above acyl-CoA species were facilely esterified when 1-palmityl sn -glycero-3-phosphate was provided as acyl acceptor. Phosphatidic acid was the major product. Monoolein was a poor acyl acceptor in the presence of bovine mammary microsomes. The significance of these observations in relation to milk glyceride synthesis is discussed.
Stereotactic radiosurgery as the primary treatment for new and recurrent paragangliomas: is open surgical resection still the treatment of choice?

Objective Paragangliomas (PGs) or glomus tumors are rare, and publications comparing treatment alternatives are few. We sought to analyze our experience with stereotactic radiosurgery (SRS), review the literature, and develop treatment guidelines. Methods We retrospectively examined the outcomes of 41 PGs in 36 patients treated with SRS at Stanford. Our data from medical records, telephone interviews, and imaging studies were combined with previously reported SRS data and compared to results following other treatments. Results With a median clinical follow-up of 4.8 years (3.9 years radiographic), local control was 100%. Complications included increase in preexistent vertigo in one patient and transient cranial neuropathies in two patients. Published surgical series describe a lower local control rate as well as more frequent and severe complications. Published radiation therapy (RT) series document a slightly lower local control rate than SRS, but SRS can be delivered more quickly and conveniently. Open surgery and other combinations of treatments appear to be required for several subpopulations of PG patients. Conclusions We feel that SRS should be the primary treatment for most new and recurrent PGs. Even some very large PGs are appropriate for SRS. RT remains an appropriate option in some centers, especially those where SRS is not available. PGs occurring in the youngest patients, catecholamine secreting PGs, and PGs causing rapidly progressing neurologic deficits may be more appropriate for open resection. Metastatic PGs may benefit from combinations of chemotherapy and SRS or RT. Treatment guidelines are proposed.
Infection imaging of children and adolescents undergoing cancer therapy: A review of modalities and an organ system approach

Abstract Diagnostic imaging plays an integral role in accurately and expeditiously diagnosing and determining the extent of infections in immunocompromised children. A histologic diagnosis can seldom be made based on imaging. However, recognition of patterns and distribution of processes, as well as familiarity with imaging methods can help limit the differential possibilities. This report reviews contemporary imaging modalities, discusses the strengths and limitations of these modalities, and describes the imaging appearances of the most common infections found in children receiving cancer therapy. Copyright © 2000 by W.B. Saunders Company
Strangers at the Benchside: Research Ethics Consultation

Institutional ethics consultation services for biomedical scientists have begun to proliferate, especially for clinical researchers. We discuss several models of ethics consultation and describe a team-based approach used at Stanford University in the context of these models. As research ethics consultation services expand, there are many unresolved questions that need to be addressed, including what the scope, composition, and purpose of such services should be, whether core competencies for consultants can and should be defined, and how conflicts of interest should be mitigated. We make preliminary recommendations for the structure and process of research ethics consultation, based on our initial experiences in a pilot program.
Treatment of rape-induced trauma: Proposed behavioral conceptualization and review of the literature

Abstract Rape-induced trauma has been identified as a precipitant of post-traumatic stress disorder, a new diagnostic category introduced in DSM III. The present paper reviews the existing theoretical models, assessment strategies, and treatment techniques applied with victims of postrape trauma, and discusses methodological problems in the existing literature. A behavioral theoretical conceptualization adapted from Stampfl and Levis is presented as having heuristic value to explain the development of post-rape trauma. The treatment implications which extend from such a conceptualization are discussed and suggestions for future research directions offered.
The Problem of Pressure Sores in a Nursing Home Population: Statistical Data

: This study on 93 patients was conducted at a skilled nursing facility. Twenty-two of the 93 patients had pressure sores; 34 of the 54 sores were present when the patients were admitted and 20 developed after admission. Only 5 of the 54 sores healed. Healing times ranged from 15 to 55 days after the beginning of treatment. Thirteen deaths occurred among the 71 patients without sores, and 17 deaths among the 22 patients with sores. Specific treatment regimens varied (cleaning solutions, antimicrobial drugs, heat, enzymatic debridement) but always included frequent changes in the position of the patient. Ten of the 22 patients with sores were anemic vs. 19 of the 71 patients without sores. Half of the patients with sores were maintained with tube feedings whereas more than half of the patients without sores received regular house diets. Pressure sores are a serious problem among geriatric patients in nursing homes. All those who care for the aged should be fully aware of the procedures involved in the prevention and management of these sores.
Vision Screening to Detect Refractive ErrorVision Screening to Detect Refractive Error

Jody Fay Leone, BAppSci(Orth)Hons; Paul Mitchell, MD, PhD, FRANZCO; Ian George Morgan, PhD; Annette Kifley, MBBS, MAppStat; Kathryn Ailsa Rose, PhDObjective: To detect significant refractive error in a population-based random cluster sample of 12-year-old schoolchildren by using sensitivity and specificity of uncorrected visual acuity (VA).Methods: The Sydney Myopia Study randomly selected 21 secondary schools stratified by socioeconomic status. All year 7 students (mean age, 12.7 years) were invited to participate. We tested VA monocularly, unaided at 2.44 m, using a retroilluminated logMAR chart. Cycloplegic autorefraction (induced with instillation of cyclopentolate hydrochloride, 1%) was used to define clinically significant refractive error as a spherical equivalent of −1.00 diopters (D) or less for myopia; at least +2.00 D for hyperopia; and −1.00 D or less cylinder power for astigmatism.Results: Data for both eyes were pooled for a total of 4497 observations. The sensitivity and specificity for all clinically significant refractive errors at the best VA cutoff level of 53 letters (6/6 −2 ) were 72.2% and 93.3%, respectively. Myopia had the highest sensitivity and specificity of any of the refractive errors for detection using VA (97.8% and 97.1%, respectively, for a 45-letter VA cutoff [6/9.5]). The best VA cutoffs for hyperopia and astigmatism were 57 (6/6 +2 ) and 55 (6/6) letters, respectively, with sensitivities of 69.2% and 77.4%, respectively, and specificities of 58.1% and 75.4%, respectively.Conclusions: In this adolescent group, a VA cutoff of 6/9.5 or less detects myopic refractive error reliably. However, there is no reliable VA cutoff for clinically significant hyperopia or astigmatism. Improved VA screening methods are required to improve detection of these conditions. Even so, with the methods described herein, the prevalence of uncorrected VA may provide a reasonably accurate estimate of the prevalence of myopia.
Violence and the politics of prestige: the fascist turn in colonial Libya

In 1922–1923, Fascist Party leaders hoped to define a sharp break from previous approaches to colonial rule and imperial expansion in Italy's Libyan territories. Mussolini's nomination of Luigi Federzoni, a leading figure of the Italian Nationalist Association, as the Minister of Colonies at the end of 1922 signalled a new era in Italian colonial administration focused on aggressive expansion and the institution of what was known as a ‘politics of prestige’. This definition of a fascist style of colonial rule appealed to the enthusiasm for violence among blackshirt militias and early fascist supporters in the Libyan territories. This definition of a fascist style of colonial rule, however, inspired immediate reaction from both colonial officials, with stakes in maintaining a measure of continuity and stability, and from those within the nascent Fascist Party who wanted to promote an alternative model of fascism in the colonies. This article examines contests to define fascism and fascist colonial rule in ...
Assessing the appropriateness of using markov decision processes for RF spectrum management

The stochastic nature of wireless communication suggests a Markov Decision Process (MDP) as a formalism for identifying and evaluating spectrum control policies. However, in practice numerous factors influence the success or failure of a transmission, so that the applicability of particular MDP models to real spectrum management problems must itself be examined. This paper presents a series of model validation studies in which correspondence between an MDP model and a discrete-event simulation (DES) model is evaluated. We test several hypotheses that together provide a foundation and an exemplar for the idea of using MDPs to guide management of shared spectrum. We conclude that there is sufficient similarity between the performance predictions made by the MDP model and the DES model that MDPs can be used effectively to determine spectrum control policies.
Effects of blueberry supplementation on measures of functional mobility in older adults

Limited functional mobility in older adults has been associated with declines in tests of motor, psychomotor, and executive function. Animal studies have demonstrated reversals in indices of motor ...
Kinetics and convection in the combustion of alkane droplets

Abstract Measurements were made of burning rates of hexadecane droplets 0.5 to 1 mm in diameter, suspended on quartz fibers in room-temperature air, at pressures from 1 to 0.1 atm. Correction factors for effects of natural convection and finite-rate gas-phase chemical kinetics are determined by least-square fitting of the burning-rate constant. Reexamination of a large amount of earlier data on burning rates of unbranched alkanes reveals appreciable influences of forced and/or natural convection. If corrections for these effects are calculated by evaluating properties at the arithmetic mean of the ambient and flame temperature, then theoretical and experimental burning rates agree within 15%.
The Forgotten Compass of Death: Apocalypse Then and Now in the Social History of South Africa

A decade after South Africa's transition from apartheid to democracy, HIV/AIDS has superseded freedom struggles as the urgent matter of the day. With one of the highest national rates of HIV infection in the world, South Africa faces a bleak demographic future. The principal mode of HIV transmission, unprotected intercourse, and the stigma that surrounds this issue have recently spurred historians to probe patterns of sexual and etiological socialization. But an equally important and related theme, perceptions of mortality, has yet to receive this level of recognition. Indeed, comprehensive studies of death seldom feature in the social history of South Africa. This exploratory article traces the intellectual and topical currents propelling social historians to broaden their understanding of sexuality and health, two phenomena determining views of mortality in the age of AIDS. It reasserts a forte of the "new" social history—the study of the "ways of death"—to offer insights to researchers seeking to integrate analyses of sexuality, disease, and mortality. Finally, by examining three epidemics in South Africa, this article explores penitential mourning as both a medium of power (through which people command deference, assign blame, or challenge authority) and a ritual of coping with the "pollution" of death and sexual transgression.
Patterns of pathologic response in the cornea

The cornea, like most tissues, manifests only a limited number of responses to the wide variety of diseases and insults that assault it. To facilitate a systematic understanding of these responses, we have divided the cornea into four zones: the epithelium; the epithelial basement membrane, Bowman's layer and anterior stroma; the stroma; and the endothelium and Descemet's membrane. We describe six pathologic processes or responses in each zone: defects; fibrosis and vascularization; edema and cysts; inflammation and immune response; deposits; and proliferation. We illustrate this paradigm with a chart that contains examples of each pathologic process in each zone.
Implementing Systems Engineering in the U. S. Department of Energy Office of the Biomass Program

The DOE Biomass Program is tackling the challenge of advancing biomass energy technologies and systems from concept to commercial adoption with a goal of enabling the production and use of biofuels to help reduce future U.S. oil consumption. The complexity of the biomass-to-biofuels system of systems and the combined dynamics of the existing agriculture, forestry, energy and transportation markets within which it operates pose challenges for reaching consensus on both a concept of operations and preferred strategies for transitioning to a significantly larger biofuels industry that is secure, reliable, environmentally responsible, and supportive of a thriving economy. To ensure that the program is focused on the activities critical to achieving its goal, the program is implementing systems engineering processes, practices, and tools to guide informed decision-making.
The auscultatory findings in primary myocardial disease.

Abstract The auscultatory abnormalities in primary myocardial disease have been reviewed. These abnormalities occur as manifestations of conduction defects, ectopic rhythms, myocardial failure, and associated pericarditis.
Longitudinal FDG-PET Revealed Regional Functional Heterogeneity of Bone Marrow, Site-Dependent Response to Treatment and Correlation with Hematological Parameters

Purpose: The purposes of this study were: 1) to show bone marrow (BM) functional heterogeneity, 2) to demonstrate site-dependent responses of BM to cancer treatment utilizing whole body FDG-PET/CT and 3) to identify correlations between FDG uptake in different bone sites and long term complete blood count (CBC). Methods: Thirty two patients who had pre- and post-treatment FDG-PET/CT scans were selected retrospectively. Each patient received either head and neck radiation for cancer of the tongue, or pelvic radiation for rectal or cervical cancer with chemotherapy. Patients had FDG-PET/CT performed prior to the first radiation therapy session and at least one FDG-PET/CT after completion of the prescribed radiation therapy. Results: FDG uptake before radiotherapy was significantly different among bone regions (p < 0.01). This heterogeneity was felt to reflect site-dependent amounts of BM contents possibly due to structural and functional requirements. FDG uptake in the irradiated regions was significantly decreased on the first and second follow-ups after radiation. Feasibly, this could be due to a reduction in the number of active BM cells following intensive radiation in addition to concurrent chemotherapy. Overall, CBC significantly decreased after treatment. Correlation values of each hematological parameter with FDG uptake varied among skeletal regions and scan time points. FDG uptake in sacrum and lumbar regions had better correlation with white blood cells and neutrophils. Conclusions: Longitudinal FDG-PET revealed a regional functional heterogeneity of the BM site-dependent response to treatment. Patients experienced immediate and prolonged marrow metabolic damage that correlates with hematological parameters. FDG-PET/CT may provide additional capabilities to assess BM health.
Income Taxation and Tax Evasion in a Finite Economy

This paper introduces tax evasion in an optimal income taxation problem. It deals with finite economies. Two different problems are addressed. First, allowing the government to use generalized tax schedules (GTS, income distribution-contingent set of lump sum transfers) `a la Piketty, we show that any first best Pareto optimum can be implemented, by proposing beside the GTS well defined audit strategy and fine function. Second, restricting the government to use classical tax schedules, we show that with the same type of audit strategy and fine function, (only) a subset of the first best Pareto allocations is implementable; moreover, all the agents except the more able evade some income and are not audited.
Industry Trends and Market Structure

The primary objective of this chapter is to provide an overview of emerging trends in the U.S. telecommunications industry following the passage of the Telecommunications Act of 1996. No attempt is made to supply a comprehensive analysis and description of the regulatory and institutional events that precipitated these events, as these are described in detail elsewhere.1 We conclude this chapter with a forecast of likely future market and institutional developments in the U.S. telecommunications industry.
Recovery of function following simultaneous and serial telencephalon ablation in the teleost, Macropodus opercularis.

Previous investigations in male Macropodus showed that simultaneous bilateral removal of the telencephalon results in decreased sexual and nest-building behavior. The current investigation was to determine whether serial unilateral ablation of the telencephalic hemispheres, increased recovery time following simultaneous ablation, or prior spawning experience can produce savings in reproductive behavior. Preoperative sexual experience did not alter the behavioral effects of telencephalon ablation. All components of reproductive behavior were decreased following serial or simultaneous ablation of the telencephalon, but none were eliminated. When simultaneous ablation males were allowed to recover for a period of time equal to that following the second operation of the serial ablation, they showed less sexual behavior than the serial ablation males. When the recovery time was equal to that following the first operation of the serial ablation, the simultaneous and serial ablation males showed no significant differences in reproductive behavior. The results indicate that removal of one lobe of the telencephalon initiates alterations in nontelencephalic structures which result in increased savings in sexual behavior following removal of the second hemisphere. Similar neural alterations may be responsible for the recovery of function following simultaneous bilateral ablation of the telencephalon.
Connective tissue synthesis by cultured scleroderma fibroblasts. II. Incorporation of 3h-glucosamine and synthesis of glycosaminoglycans

Fibroblasts from normal and scleroderma skin, grown tissue culture, were incubated with 3H-glucosamine for 24 hours. No definite trends could be established in 3H-glucosamin incorporation or glycosaminoglycan synthesis. Over 90% of the total 3H activity as well as the glycosaminoglycans synthesized were secreted into the medium. Characterization of glycosaminoglycans showed that in both the medium and cells, hyaluronic acid ins the major glycosaminoglycan in normal and scleroderma fibroblasts. In the medium, hyaluronic acid represented 87% of the total glycosaminoglycans; it was slightly decreased in the cells. Fibroblasts were compared from the upper and lower areas of the affected dermis and an uninvolved dermal area of the same scleroderma patients.
Occasional reinforced trials during extinction can slow the rate of rapid reacquisition

Abstract Two appetitive conditioning experiments with rats examined reacquisition after conditioned responding was eliminated by either extinction or by a partial reinforcement procedure in which reinforced trials were occasionally presented among many nonreinforced trials. In Experiment 1, reacquisition to a conditional stimulus (CS) that had been conditioned and extinguished was more rapid than acquisition in a group that had received no prior conditioning. However, the addition of occasional reinforced trials to extinction slowed this rapid reacquisition effect. Experiment 2 replicated the result and showed that a procedure in which the CS and the unconditional stimulus (US) were unpaired in extinction interfered even further with reacquisition. The results suggest that rapid reacquisition is ordinarily produced when reinforced trials provide a contextual cue that can renew responding by signaling other acquisition trials ( Ricker & Bouton, 1996 ). The effects of partial reinforcement in extinction are surprising from several theoretical perspectives and have useful clinical implications.
Estimation of tibial shaft defect volume using standard radiographs: development and validation of a novel technique.

Abstract Background No simple clinical technique with which to measure the volume of bone gaps in the treatment of open fractures or nonunions of the tibia is currently available. It is difficult to compare the three-dimensional magnitude of bone defects in research studies on bone grafting without such a tool, and clinicians have no way of determining the magnitude of defects in clinical practice. The purposes of this study were to develop and to validate a technique with which to accurately measure bone gap volumes of the tibial shaft by using only simple measurements on already available clinical radiographs and a simple equation. We hypothesized that a technique could be developed using anteroposterior- and lateral-view radiographs of the tibia to accurately determine the volume of a tibial shaft fracture. Methods We created standardized fracture gap models using 45 synthetic tibiae cut in different locations and orientations, rendering 135 gaps. We developed and validated a hydrostatic suspension technique to determine the volume of each bone, which underwent anteroposterior- and lateral-view radiography after each cut. Radiographic measurements were used to calculate defect volumes based on a simple equation. Predicted volumes were compared with measured volumes. Results The triangular prism equation matched well with the actual volumes. Linear regression analysis showed a slope of 0.92 and R2 of 0.97. Conclusion The equation provides a simple technique with which to calculate three-dimensional gap volumes based on standard radiographs. The simplicity of the equation and availability of standard radiographs make this a practical research and perhaps clinical tool that might be useful in quantifying volumes of the tibial shaft defect.