cssi/SciSciGPT-SciSciNet huggingface dataset:
Requirements for comparing the performance of finite element models of biological structures.

Abstract The widespread availability of three-dimensional imaging and computational power has fostered a rapid increase in the number of biologists using finite element analysis (FEA) to investigate the mechanical function of living and extinct organisms. The inevitable rise of studies that compare finite element models brings to the fore two critical questions about how such comparative analyses can and should be conducted: (1) what metrics are appropriate for assessing the performance of biological structures using finite element modeling? and, (2) how can performance be compared such that the effects of size and shape are disentangled? With respect to performance, we argue that energy efficiency is a reasonable optimality criterion for biological structures and we show that the total strain energy (a measure of work expended deforming a structure) is a robust metric for comparing the mechanical efficiency of structures modeled with finite elements. Results of finite element analyses can be interpreted with confidence when model input parameters (muscle forces, detailed material properties) and/or output parameters (reaction forces, strains) are well-documented by studies of living animals. However, many researchers wish to compare species for which these input and validation data are difficult or impossible to acquire. In these cases, researchers can still compare the performance of structures that differ in shape if variation in size is controlled. We offer a theoretical framework and empirical data demonstrating that scaling finite element models to equal force: surface area ratios removes the effects of model size and provides a comparison of stress-strength performance based solely on shape. Further, models scaled to have equal applied force:volume ratios provide the basis for strain energy comparison. Thus, although finite element analyses of biological structures should be validated experimentally whenever possible, this study demonstrates that the relative performance of un-validated models can be compared so long as they are scaled properly.
(En)gendering Testimonial Bodies of Evidence and Italian Antimafia Culture: Rita Atria

Designed to provide a critical perspective on problems raised by cultural representations of the collaboratrice con la giustizia, this exploratory study examines the case of Rita Atria. Raised in a...
Cerebral phaeohyphomycosis mimics high-grade astrocytoma

The incidence of cerebral phaeohyphomycosis, an infection caused by a dark-pigmented fungus, is increasing. The infection may mimic a high-grade glioma clinically and radiographically. Magnetic resonance spectroscopy may be helpful in differentiating the two. We report two cases to increase the awareness of cerebral phaeohyphomycosis in the clinical neurosciences. Early biopsy establishing the diagnosis, followed by aggressive combined surgical and medical management is necessary for a good outcome.
On the applicability of diffusional flow to the creep of polycrystalline materials at low stresses and intermediate temperatures

Abstract It is shown that no evidence exists for diffusional (Coble) creep in single-phase metal-base polycrystals at intermediate temperatures and low stresses. At stresses above about 10−5E (where E is Young's modulus), grain boundary sliding is more facile than diffusional flow and, at stresses below 10−5E, plastic flow mechanisms not associated with diffusional flow dominate deformation. The recent statements of Sritharan and Jones regarding the inapplicability of a phenomenological relation based on grain boundary sliding in describing low stress creep are shown to be incorrect. Specifically, their arguments are invalid regarding (1) the representation of creep data as dotϵ ∫ σ2 (dotϵ is the creep rate and σ is the stress), (2) the use of an “empirical” equation for describing the grain boundary diffusivity and (3) the position of the boundary between diffusional creep and grain boundary sliding in a deformation mechanism map. Phenomenological creep relations for describing grain boundary sliding and diffusion-controlled dislocation creep correctly predict the influence of grain size on the range of stress and strain rate where dotϵ ∫ σ2.
Understanding storage starch biosynthesis in plants: a means to quality improvement

The many varied uses of starch in food and industrial applications often requires an understanding of its physicochemical properties and the detailed variations in granule structure that underpin these properties. The ability to manipulate storage starch structures depends on understanding the biosynthetic pathway, and in particular, how the many components of the pathway are coordinated and regulated. This article presents a current overview of starch structure and the known enzymes involved in the synthesis of the granule, with an emphasis on how current knowledge on the regulation of the pathway in cereals and other crops may be applied to the production of different functional starches.
The spatial attributes of stimulus frequency and their role in monaural localization of sound in the horizontal plane.

Listeners, whose right ears were blocked, located low-intensity sounds originating from loudspeakers placed 15 deg apart along the horizontal plane on the side of the open, or functioning, ear. In Experiment 1, the stimuli consisted of noise bursts, 1.0 kHz wide and centered at 4.0 through 14.0 kHz in steps of .5 kHz. We found that the apparent location of the noise bursts was governed by their frequency composition. Specifically, as the center frequency was increased from 4.0 to about 8.0 kHz, the sound appeared to move away from the frontal sector and toward the side. This migration pattern of the apparent sound source was observed again when the center frequency was increased from 8.0 to about 12.0 kHz. Then, with center frequencies of 13.0 and 14.0 kHz, the sound appeared once more in front. We referred to this relation between frequency composition and apparent location in terms of spatial referent maps. In Experiment 2, we showed that localization was more proficient if the frequency content of the stimulus served to connect adjacent spatial referent maps rather than falling within a single map. By these means, we have further elucidated the spectral cues utilized in monaural localization of sound in the horizontal plane.
Probabilistic description of fatigue crack growth in polycrystalline solids

Abstract A stochastic model describing the crack evolution and scatter associated with the crack propagation process has been built on the basis of the discontinuous Markovian process. The evolution and scatter are identified in terms of constant probability curves whose equation is derived as In P r (i) = B(e KI 0 − e Ki ) , i ≥ I 0 , where i is the number of cycles, B and K are crack-length-dependent variables, P r (i) is the probabiliity of the crack being at position r along the fracture surface after i cycles elapse and I 0 is the minimum number of cycles required for the crack to advance from one position on the fracture surface to the next. The validity of the model is established by comparing the crack growth curves generated for Al 2024-T3 at a specific loading condition with those experimentally obtained.
The McCollough effect with plaids and gratings: evidence for a plaid-selective visual mechanism.

We investigate if adapting to colored plaids produces a McCollough effect on plaids or gratings and if adapting to colored gratings produces a McCollough effect on plaids. We find that the answer is unambiguously yes in all cases, though the strength of the effect differs significantly depending on the inducing and testing stimuli. Furthermore, we show that plaids and gratings can simultaneously support opposite color aftereffects, suggesting that plaids drive a population of cells which are not stimulated by the same component gratings in isolation.
Effects of Initiation of 3′-Azido,3′-Deoxythymidine (Zidovudine) Treatment at Different Times after Infection of Rhesus Monkeys with Simian Immunodeficiency Virus

The effects of initiating treatment with 3'-azido-3'-deoxythymidine (zidovudine) at different times after inoculation of simian immunodeficiency virus (SIV) were investigated in rhesus monkeys. Zidovudine treatments of 100 mg/kg/day (25 mg/kg, subcutaneously every 6 h) were initiated 1, 8, 24, or 72 h after intravenous inoculation of 10 ID50 of SIV. Treatments continued for 28 days, and results were compared with those of saline-treated controls. Serum infectious virus titers 14 days after inoculation (AI) significantly decreased after treatment initiation 1, 8, or 24 h AI. Titers were correlated with the time treatment was initiated. Treatments initiated 1-72 h AI prevented the establishment of persistent SIV antigenemia; greater effects were observed with earlier initiation of treatment. Treatments initiated 1-8 h AI resulted in decreased levels of viral antigenemia 14 days AI and delayed decreases in CD4+CD29+ blood lymphocytes. Earlier treatment initiation resulted in delayed recurrence of antigenemia, with a tendency for longer survival. Early initiation of treatment may be important for limiting initial viral replication and dissemination in cases of known exposure.
Pulmonary edema with low pulmonary capillary wedge pressure after acute myocardial infarction: Clinical features and prognostic implications

Abstract Pulmonary edema is a frequent finding after acute myocardial infarction, and is generally thought to be the result of myocardial dysfunction, particularly when an elevated pulmonary capillary wedge pressure (PCWP) is observed. Several recent reports suggest that pulmonary edema without an elevated PCWP can also occur after myocardial infarction. Therefore, we performed a retrospective review of patients with acute infarction to see whether individuals with this complication could be identified. Among 104 patients with myocardial infarction, persistent (>24 hours) pulmonary edema with a low PCWP (≤16 mm mercury) was present in ten patients. In these cases, pulmonary edema was preceded by hypotension in five patients. Individuals with this clinical picture compared to those with pulmonary edema and a high PCWP (≥16 mm mercury, cardiogenic), had more severe hypoxemia (P
Genomic profile of maize response to Aspergillus flavus infection.

The opportunistic pathogen Aspergillus flavus infects important seed crops, including corn, peanuts, and cotton. A. flavus is capable of producing mycotoxins called aflatoxins. Aflatoxin B1, the major mycotoxin contaminant of maize, is a potent carcinogen and has been directly linked to hepatocellular carcinoma. Natural sources of maize fungal resistance exist, but efforts to increase resistance through traditional plant breeding have yielded little success. Using the maize Unigene 1-1.05 arrays, a comparison of resistant (Mp313E) and susceptible (Va35) inbred maize lines 48 hours post-A. flavus infection identified 236 genes as significant. During infection, 135 genes were up-regulated in the susceptible maize line Va35, 112 genes were up-regulated in the resistant maize line Mp313E, 12 genes were up-regulated in both lines, and 1 gene was down-regulated in both lines compared to uninfected lines. Comparisons of the biological profile responses of these maize lines revealed a striking difference in react...
Rigorous optimization of heat-integrated and Petlyuk column distillation configurations based on feed conditions

The steady-state design and rigorous simulation of conventional distillation configurations and several energy-integrated configurations has been studied for ternary mixture separation. The studied configurations are optimized rigorously based on total annual cost as the economic objective function. The energy-integrated distillation configurations are compared with conventional configurations to find the maximum achievable total annual cost savings. Changing feed conditions is considered as one of the optimization variables by investigating different states of feed conditions; feed at 15.5°C temperature, liquid at bubble point and vapor at dew point. The investigated configurations are conventional direct and indirect separation sequence, heat-integrated direct sequences, Petlyuk column, heat-integrated sloppy sequence, and double heat-integrated sloppy sequence. Optimization results indicate that saving in energy and total annual cost of the configurations is affected by the states of the feed conditions.
The Stability of the Competitive System which contains Gross Complementary Goods

1. It is well known that the Walrasian tatonnement adjustment process is dynamically stable if all commodities are gross substitutes and if the matrix of excess demand coefficients satisfies the Hicksian conditions (Metzler [5]). The process can be stable under more general conditions such as when some non-nume'raire goods are gross complements. For instance, when the matrix is a symmetric matrix or a Morishima matrix, and satisfies the Hicksian conditions (Samuelson [9], Morishima [6, 7]), or when it is a quasi-negative definite matrix (Samuelson [9]) or a dominant (negative) diagonal matrix, the adjustment process is dynamically stable even if not all commodities are gross substitutes. If we consider the Morishima case as being representative of the systems in which all commodities are not necessarily gross substitutes, the matrix of excess demand coefficients, A, satisfies the conditions, sign aij = sign aji and sign aik.akj = sign aij (i # j). This means that if the jth commodity is a substitute of a substitute (or a complement of a complement) for the ith commodity, then the jth commodity is necessarily a substitute for the ith commodity. If the jth commodity is a complement of a substitute (or a substitute of a complement) for the ith commodity, then thejth commodity is necessarily a complement with the ith commodity.3 The substitute-complement relationships in the Morishima matrix represent, certainly, an important and ingenious step forward in the study of the competitive system with complementary goods, in particular, when some commodities are not differentiated in use. (For instance, the economy which contains tea from India, tea from Ceylon, sugar from Cuba, sugar from Hawaii, etc.). However, in reality the substitute-complement relationships may not obey these simple rules.
On the modeling of periodic structures using the finite-difference time-domain algorithm

In this paper, we present a technique for modeling periodic structures, such as spatial filters and photonic bandgap materials, using the finite-difference time-domain (FDTD) algorithm, for both the normal and oblique incidence cases. A waveguide simulator technique is employed to model these periodic structures, and the issue of arbitrary angles of incidence as well as the problem of sweeping frequency of the illuminating wave, that are difficult to handle in the FDTD waveguide simulator approach, are addressed. Comparisons with results derived using other techniques are presented, and good agreement is demonstrated. © 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 24: 151–155, 2000.
Normativity and Instrumentalism in David Lewis’ Convention

David Lewis presented Convention as an alternative to the conventionalism characteristic of early-twentieth-century analytic philosophy. Rudolf Carnap is well known for suggesting the arbitrariness of any particular linguistic convention for engaging in scientific inquiry. Analytic truths are self-consistent, and are not checked against empirical facts to ascertain their veracity. In keeping with the logical positivists before him, Lewis concludes that linguistic communication is conventional. However, despite his firm allegiance to conventions underlying not just languages but also social customs, he pioneered the view that convening need not require any active agreement to participate. Lewis proposed that conventions arise from “an exchange of manifestations of a propensity to conform to a regularity” (87–8). In reasserting the conventional quality of languages and other practices resting on mutual expectations, Lewis comfortably works within the analytic tradition. Yet he also deviates from his predece...
The Impact of Multisatellite Data on the Initialization and Simulation of Hurricane Lili’s (2002) Rapid Weakening Phase

Abstract Numerical experiments have been conducted to examine the impact of multisatellite data on the initialization and forecast of the rapid weakening of Hurricane Lili (in 2002) from 0000 UTC to landfall in Louisiana on 1300 UTC 3 October 2002. Fifth-generation Pennsylvania State University–National Center for Atmospheric Research (PSU–NCAR) Mesoscale Model (MM5) 4DVAR sensitivity runs were conducted separately with QuikSCAT surface winds, the Geostationary Operational Environmental Satellite-8 (GOES-8) cloud drift–water vapor winds, and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) temperature–dewpoint sounding data to investigate their individual impact on storm track and intensity. The results were compared against a simulation initialized from a Global Forecast System background interpolated to the MM5 grid. Assimilating QuikSCAT surface wind data improves the analyzed outer-core surface winds, as well as the inner-core low-level temperature and moisture fields. Substantial adjustment...
Disagreement in bargaining: An empirical analysis of OPEC

Abstract We consider a stylised model in which two cartel members bargain over the aggregate-production quota in a world of asymmetric information. We show that when the two cartel members are sufficiently different, the probability of agreement depends on both the current state of demand and initial production. Specifically, the probability of agreement is much lower when demand is low (and initial production is relatively high) than when demand is high (and initial production is relatively low). We also find that, regardless of the current demand state, the more extreme is initial production, the higher is the probability of agreement. Using an event study, where we take as events OPEC production quota announcements, we demonstrate empirically that the predictions of the model are borne out.
Isolation of the dorsal locus of Drosophila

The establishment of embryonic polarity is a crucial step in pattern formation and morphogenesis. In the fruitfly Drosophila melanogaster, embryonic polarity depends primarily on genes expressed in the female during oogenesis. Mutations in these 'maternal effect' genes can lead to major disruptions in normal pattern formation. Two classes of maternal genes essential for the establishment of polarity in the embryo have been identified. Lesions in one class, the 'bicaudal' genes, disrupt the anterior-posterior axis; lesions in the other class disrupt dorsal-ventral polarity, and in the most extreme cases embryos fail to form any ventral or lateral structures. Genetic studies suggest that the anterior-posterior and dorsal-ventral axes may be independent as the defects observed in mutants from each class seem to be restricted to one axis only. The dorsal (dl) locus is one of the maternal effect genes involved in the establishment of dorsal-ventral polarity. Homozygous dl females produce embryos exhibiting the mutant phenotype--complete lack of dorsal-ventral polarity in the strongest alleles--irrespective of the genotype of the father. Although dl is a maternal effect locus and must be expressed during oogenesis, the gene product, or a substance depending on the normal function of the dl gene, seems to be active early in embryogenesis, as the dl phenotype can be partially rescued by injection of cytoplasm from wild-type cleavage-stage embryos. Here we report the molecular cloning of the dorsal locus and a study of its expression.
The Plane Poiseuille Flow of a Particle-Fluid Mixture

The “laminar” shear flow of a particle-fluid mixture is studied using the two-fluid model, which is based on equations of conservation of mass and momentum for each material. The equations are applied to plane parallel flow, where the equations or mixture axial momentum and an equation for the concentration across the channel are derived. An asymptotic solution to the equations is derived which shows that the particles move to the center of the channel, forming a core which does not shear. The core is surrounded by clear fluid layers where all the shear occurs.
Physiologic responses to non-startling tones in Vietnam veterans with post-traumatic stress disorder

We evaluated eyeblink and autonomic reactivity to non-startling acoustic stimuli in a convenience sample of Vietnam combat veterans. Twenty veterans with current PTSD and 19 veterans who never had PTSD were exposed to 15 consecutive 86-dB, 500-ms, 100-Hz tones with 40-ms rise and fall times, while orbicularis oculi electromyogram (EMG), skin conductance (SC) and heart rate (HR) responses were measured. PTSD subjects had higher resting HR levels and produced larger averaged HR responses across the 15 tone presentations compared to non-PTSD subjects. Skin conductance and EMG responses did not differ between the groups. Results suggest that previous findings of larger HR responses to loud tones in PTSD extend to lower intensity, non-startling stimuli, but that the magnitude of the HR response appears smaller to the lower intensity stimuli. Previously observed differences in the magnitude of the eyeblink response and rate of decline of SC responses in PTSD to high intensity stimuli appear to disappear when using non-startling stimuli.
Project HealthDesign: Rethinking the power and potential of personal health records

Project HealthDesign, a multi-year, multi-site project sponsored by the Robert Wood Johnson Foundation with additional support from the California HealthCare Foundation, is designed to stimulate innovation in personal health records (PHRs). Project HealthDesign teams employed user-centered design processes to create designs and prototypes of computer-based applications to support and enhance human health for a wide range of patients, from children with chronic health conditions to elders transitioning from hospital to home. A program design philosophy encouraged designers to envision PHRs as a suite of personal health information management tools, or applications, separate from, but drawing upon, personal health data from a variety of sources. In addition to information contained in one's medical record, these personal health data included patient-supplied clinical parameters such as blood glucose and daily weights; as well as patient-generated observations of daily living (ODLs) - the unique, idiosyncratic cues, such as sleep adequacy or confidence in self care, that inform patients about their abilities to manage health challenges and take healthy action. A common technical platform provided infrastructure services such as data standards and identity-management protocols, and helped to demonstrate a scalable, efficient approach to user-centered design of personal health information management systems. The program's ethical, legal and social issues consultancy identified challenges to acceleration of action-focused PHRs: personal control of privacy choices, management of privacy in home conditions, and rebalancing power structures in shared decision making.
Productive Influences on High School Student Achievement

AbstractA secondary analysis of the High School and Beyond (HSB) data was performed in order to retest the private-school superiority hypothesis and to examine determinants of high school achievement. This analysis attempted to explain the fixed and alterable conditions which influence the achievement of 26,279 sophomores in reading, writing, mathematics, science, and civics. Multiple regression and partial correlations indicated that those variables beyond the control of educators (i.e., amount of homework completed, television viewing, parental involvement with education) explained much of the achievement variation. However, variables under school control, such as quantity and appropriateness of academic instruction, were found to explain significant and educationally meaningful amounts of achievement variance. With background variables controlled, private schools did not outperform public schools.
Universal leukoreduction of cellular blood components in 2001? No.

Leukocytes are known to have a number of biologic effects associated with allogeneic blood transfusion ❚Table 1❚. The potential clinical importance of these effects, which are the focus of current debate over the merits of “universal” leukocyte reduction (leukoreduction; cellular components with <5 × 106 leukocytes) include the following: febrile-associated transfusion reactions (FATRs), transfusion-related alloimmunization to platelets, and transfusion-related immunomodulation. Several recent reviews1,2 of this topic, along with commentaries3-6 about the use of leukocytedepleted blood components, have been published. The Blood Products Advisory Committee (BPAC) to the US Food and Drug Administration (FDA) voted 13-0 on September 18, 1998, in favor of universal leukoreduction of blood components,7 but the minutes stated that many committee members agreed there were insufficient good studies, and everyone wanted more data.8 To date, both leukoreduced and nonleukoreduced blood components remain FDA-approved. This commentary will summarize my view of this controversy and the need for additional controlled clinical trials to provide data to resolve this issue. ❚Table 2❚ summarizes the percentage of blood components transfused that were leukoreduced in the United States in 1994 and 1997. The percentages for RBCs (17.6% and 18.3%) and platelets (16.5% and 15.5%) remained static, despite commercial advertisements to clinicians about leukocyte-depletion filters during this period.9 For the first 9 months of 1999, 3,592 (13%) of 27,663 RBC units transfused at our hospital were leukoreduced; our indications for leukoreduction reflect those published previously,4 and are summarized in ❚Table 3❚. FATRs occur in only 0.5% of RBC transfusions; of these, 18% and 8% of patients experience a second or third FATR.10 Approximately 18% of platelet transfusions are
Comments on: "Development, validity, and reliability of The Assessment of Pain and Occupational Performance (POP)--a new instrument using two dimensions in the investigation of disability in low back pain: psychometric issues associated with the POP".

In developing a new assessment test, it is of utmost importance to adhere to the best psychometric properties for test construction to ensure the highest reliability and validity for that test. In an earlier publication, I have discussed these properties [1]. In reviewing the procedure used in the development of The Assessment of Pain and Occupational Performance (POP) appearing in this issue [2], there are some major issues that can be raised in its development, as will be delineated here: Reliability refers to the reproducibility of a test from one administration to the next. It should be expected that if a test is administered at two points in time, with no major intervening circumstances possibly affecting the construct or dimension being measured (eg, pain, level of activity, and so forth), then the test-retest reliability should be high. If not, there may be flaws in the test that make it less than acceptable for use. Nowhere in the present study of the POP was patient test-retest reliability ever calculated! Only the occupational therapists’ interrater reliability was reported. Moreover, this was computed for only 25 patients from primary care. Validity refers to the appropriateness and usefulness of a test in making an inference about a patient’s behavior (eg, the level of pain intensity being experienced, the level of physical activity, and so forth). There are, in turn, different types of validity. B Predictive validity refers to whether test scores can predict subsequent measures or behaviors. For example, will a high score on the POP predict whether a patient will require a greater amount of pain management, medication, and so forth? In the present study, predictive validity was not evaluated. B Concurrent (or convergent) validity refers to whether test scores are correlated with other current measures or behaviors. In the present study, certain portions of the Oswestry Disability Index were used in assessing their relationship with portions of the POP. Two major issues arose when evaluating these data. The first was why only 91 patients from the ‘‘specific’’ pain group were used for these analyses, rather than the larger entire cohort of 220 patients? The second concerns the less than perfect correlations found (0.70‐0.78) that account for only 0.49 and 0.61 of the variance, respectively. B Content validity refers to whether test scores are representative of the quality being measured. This is most often evaluated by having experts in the field who agree that a measure of pain/functioning is actually evaluating that quality. In the present study, the patients themselves were used to determine the relevance or ‘‘face validity’’ of the 34 activities. However, only 53 patients with chronic musculoskeletal pain were used for this analysis. B Construct validity is somewhat abstract and difficult
Mouse Models of Human Lysosomal Diseases

Genetically authentic animal models of human lysosomal diseases occur spontaneously in many mammalian species. However, most are among larger domestic or farm animals with only two well-defined genetic lysosomal diseases known among rodents. This status changed dramatically in recent years with the advent of the combined homologous recombination and embryonic stem cell technology, which allows directed generation of mouse models that are genetically equivalent to human diseases. Almost all known human sphingolipidoses, two mucopolysaccharidoses and aspartylglycosaminuria have so far been duplicated in mice and more are expected in the near future. This technology also allows generation of mouse mutants that are not known or are highly unlikely to exist in humans, such as "double-knockouts." These animal models will play an important role in studies of the pathogenesis and treatment of these disorders. While the utility of these mouse models is obvious, species differences in brain development and metabolic pathways must be always remembered, if the ultimate goal of the study is application to human patients.
Hypotension in a woman with a metastatic dopamine-secreting carotid body tumor.

OBJECTIVE To describe a woman with metastatic carotid body tumor in whom hypotension occurred in the setting of exceedingly high plasma dopamine levels. METHODS We present a case report and review the literature on the topic of dopamine-secreting paraganglioma or pheochromocytoma. RESULTS A previously healthy 40-year-old Asian woman noted difficulty with swallowing and hoarseness. No neck mass was visible, and she had no symptoms of catecholamine excess and no family history of endocrine disorders or malignant disease. Indirect laryngoscopy revealed a paralyzed left vocal cord and a nonulcerating mass in the left parapharyngeal space. An initial needle biopsy was interpreted as undifferentiated carcinoma. After a second biopsy, this mass was diagnosed as a neuroendocrine tumor, consistent with paraganglioma. The patient underwent surgical resection and radiation therapy (total dose, 40 Gy), after which she remained asymptomatic for 11 years. Then loss of weight, fatigue, nausea, and hypotensive episodes (blood pressures as low as 70/35 mm Hg) prompted whole-body imaging with bone scans, computed tomography, and magnetic resonance imaging, which disclosed several lesions in the liver, lungs, and spine, suggestive of metastatic disease. The adrenal glands were unremarkable. A metaiodobenzylguanidine scan with use of (131)I was negative. Liver biopsy of a hypodense lesion revealed a neuroendocrine tumor by histologic and immunohistochemical studies. Because of the patient's history, malignant paraganglioma was diagnosed. The tumor secreted predominantly dopamine at extraordinary levels (plasma concentration 27,942 pg/mL; normal, <30). The patient died before further treatment could be initiated. CONCLUSION Carotid body tumors usually do not secrete catecholamines but frequently metastasize. During progression, these neuroendocrine tumors may become able to produce and secrete selected catecholamines such as dopamine. Dopamine can lower the blood pressure rather than causing hypertension, even though hypertension is one of the main symptoms of a pheochromocytoma.
Hybrid vector quantization/neural tree network classifiers for speaker recognition

A new classification system for text-independent speaker recognition is presented. Text- independent speaker recognition systems generally model each speaker with a single classifier. The traditional methods use unsupervised training algorithms, such as vector quantization (VQ), to model each speaker. Such methods base their decision on the distortion between an observation and the speaker model. Recently, supervised training algorithms, such as neural networks, have been successfully applied to speaker recognition. Here, each speaker is represented by a neural network. Due to their discriminative training, neural networks capture the differences between speakers and use this criteria for decision making. Hence, the output of a neural network can be considered as an interclass measure. The VQ classifier, on the other hand, uses a distortion which is independent of the other speaker models, and can be considered as an intraclass measure. Since these two measures are based on different criteria, they can be effectively combined to yield improved performance. This paper uses data fusion concepts to combine the outputs of the neural tree network and VQ classifiers. The combined system is evaluated for text-independent speaker identification and verification and is shown to outperform either classifier when used individually.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
An equational framework for the flow analysis of higher order functional programs

We present a simple method for the general flow analysis of high-order functional programs. The method computes an abstraction of the program's runtime environment via a system of monotonic equations. As the environment can grow unbounded, we exploit patterns in the program's control structure (i.e., the call-tree) to determine some static partition of the environment, and merge points in the environment belonging to the same equivalent-class. High order functions are handled by embedding control information into closures. The method is proven correct with respect to a rewriting system based operational semantics. Various implementation issues are also considered.
Processes of nickel and cobalt uptake by a manganese oxide forming sediment in Pinal creek, Globe Mining District, Arizona

A series of column experiments was conducted using manganese oxide coated sediments collected from the hyporheic zone in Pinal Creek (AZ), a metal-contaminated stream, to study the uptake and retention of Mn, Ni, and Co. Experimental variables included the absence (abiotic) and presence (biotic) of active Mn-oxidizing bacteria, the absence and presence of dissolved Mn, and sediment manganese oxide content. Uptake of Mn under biotic conditions was between 8 and 39% higher than under abiotic conditions. Continuous uptake of Mn due to biotic oxidation was evident from extraction of column sediments. Manganese uptake is hypothesized to initially occur as adsorption, which led to subsequent surface and/or microbial oxidation. Complete breakthrough of Ni within 100 pore volumes indicated no process of continuous uptake and was modeled as an equilibrium adsorption process. Nickel uptake in the presence of dissolved Mn was 67-100% reversible. Sediment extractions suggest that Ni uptake occurred through weak and strong adsorption. Continuous uptake of cobalt increased with sediment manganese oxide content, and Co uptake was up to 75% greater under biotic than abiotic conditions. Cobalt uptake was controlled by both existing and newly formed manganese oxides. Only a small amount of Co uptake was reversible (10-25%). XANES spectral analysis indicated that most Co(II) was oxidized to Co(III) and probably incorporated structurally into manganese oxides. Although manganese oxides were the primary phase controlling uptake and retention of Mn, Ni, and Co, the mechanisms varied among the metals.
Eigenvalue comparisons for a class of boundary value problems of second order difference equations

Abstract We consider the boundary value problem for second order difference equation Δ ( r i - 1 Δ y i - 1 ) - b i y i + λ a i y i = 0 , 1 ⩽ i ⩽ n , y 0 - τ y 1 = y n + 1 - δ y n = 0 . In this study we do not require the positiveness of { a k } k = 1 n . We focus on the structure of eigenvalues of this problem and comparisons of all eigenvalues as the coefficients { a i } i = 1 n , { b i } i = 1 n , { r i } i = 0 n and the parameters τ , δ change.
Sex chromosome mosaicism in disorders of sexual differentiation: Incidence in various tissues**

Some patients with sexual anomalies have sex chromosome mosaicism. It often is stated that unless cells from multiple tissues are cultured and karyotyped, many cases of sex chromosome mosaicism will be overlooked. In the present study, involving 31 cases of Turner's syndrome, 8 cases of male pseudohermaphroditism, and 4 cases of Klinefelter's syndrome, an effort was made to obtain cells from other tissues, as well as from peripheral blood for culture and karyotyping. In only one instance (Turner's syndrome) was there mosaicism in skin fibroblasts which was not detected in leukocyte cultures. In another patient (pseudohermaphrodite), mosaicism was present in leukocytes only. It is concluded that very few instances of sex chromosome mosaicism will escape detection if leukocyte cultures only are carried out. This finding is confirmed by the fact that in various reported cytogenetic studies involving patients with Turner's syndrome, the incidence of mosaicism, as in the present study, has been about 1:3, whether leukocytes alone or leukocytes plus cells from other tissues were studied.
Shadow of the head of Comet Kohoutek

An earlier reported shadow of the head of Comet Kohoutek (1973f) was not found in later photographs of the comet. However, linear dark areas were seen and are described as the space between the plasma and the dust tails. The discrepancy in earlier observations is attributed to low resolution in them. Observation of a shadow is also discounted in terms of cometary physics, due to low dust content and the weakness and curvature of the dust tail.
Mean Free Path of Hot Electrons and Holes in Metals

The mean free paths and attenuation lengths of hot electrons and holes in metals are calculated by Morte Cario methods. The results are compared with experimental results for electrons in Au,-Ag, Cu, and Pd and holes in Au. (T.F.H.)
Variational description of the ground state of the repulsive two-dimensional Hubbard model in terms of nonorthogonal symmetry-projected Slater determinants

The few-determinant (FED) methodology, introduced in our previous works [R. Rodr\'{\i}guez-Guzm\'an et al., Phys. Rev. B 87, 235129 (2013); Phys. Rev. B 89, 195109 (2014)] for one-dimensional (1D) lattices, is here adapted for the repulsive two-dimensional Hubbard model at half filling and with finite doping fractions. Within this configuration mixing scheme, a given ground state with well-defined spin and space group quantum numbers is expanded in terms of a nonorthogonal symmetry-projected basis determined through chains of variation-after-projection calculations. The results obtained for the ground-state and correlation energies of half-filled and doped $4\ifmmode\times\else\texttimes\fi{}4,\phantom{\rule{0.16em}{0ex}}6\ifmmode\times\else\texttimes\fi{}6,\phantom{\rule{0.16em}{0ex}}8\ifmmode\times\else\texttimes\fi{}8$, and $10\ifmmode\times\else\texttimes\fi{}10$ lattices, as well as momentum distributions and spin-spin correlation functions in small lattices, compare well with those obtained using other state-of-the-art approximations. The structure of the intrinsic determinants resulting from the variational strategy is interpreted in terms of defects that encode information on the basic units of quantum fluctuations in the considered 2D systems. The varying nature of the underlying quantum fluctuations, reflected in a transition to a stripe regime for increasing on-site repulsions, is discussed using the intrinsic determinants belonging to a $16\ifmmode\times\else\texttimes\fi{}4$ lattice with 56 electrons. Such a transition is further illustrated by computing spin-spin and charge-charge correlation functions with the corresponding multireference FED wave functions. In good agreement with previous studies, the analysis of the pairing correlation functions reveals a weak enhancement of the extended $s$-wave and ${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$ pairing modes. Given the quality of results here reported together with those previously obtained for 1D lattices and the parallelization properties of the FED scheme, we believe that symmetry projection techniques are very well suited for building ground-state wave functions of correlated electronic systems, regardless of their dimensionality.
Mitochondrial damage as a mechanism of cell injury in the killing of cultured hepatocytes by tert-butyl hydroperoxide

The killing of cultured hepatocytes by tert-butyl hydroperoxide (TBHP) occurs by different mechanisms depending on the presence or absence of the antioxidant N,N'-diphenylphenylenediamine (DPPD). In either situation there is evidence of mitochondrial damage. The mitochondrial inner membrane potential is lost, a result determined by the release from the cells of the lipophilic cation [3H]triphenylmethylphosphonium (TPMP+). Deenergization of the mitochondria is accompanied by a loss of ATP. Oligomycin reduced ATP stores without release of TPMP+ or without effect on the viability of the hepatocytes over the same time course that TBHP killed the majority of the cells. Monensin, a H+/Na+ ionophore, potentiated the toxicity of tert-butyl hydroperoxide in the presence or absence of DPPD. By contrast, extracellular acidosis reduced the toxicity of tert-butyl hydroperoxide in the presence or absence of DPPD. Neither monensin nor extracellular acidosis affected the metabolism of tert-butyl hydroperoxide, the release of TPMP+, or the extent of the peroxidation of cellular lipids. These data document the presence of mitochondrial damage in hepatocytes intoxicated with TBHP in both the presence and absence of DPPD. Furthermore, the potentiation by monensin is readily explained by the proposal that mitochondrial deenergization is accompanied by an intracellular acidosis. Such acidosis tends to delay the development of lethal cell injury. The protective effect of extracellular acidosis supports this interpretation.
Computing folding pathways between RNA secondary structures

Given an RNA sequence and two designated secondary structures A, B, we describe a new algorithm that computes a nearly optimal folding pathway from A to B. The algorithm, RNAtabupath, employs a tabu semi-greedy heuristic, known to be an effective search strategy in combinatorial optimization. Folding pathways, sometimes called routes or trajectories, are computed by RNAtabupath in a fraction of the time required by the barriers program of Vienna RNA Package. We benchmark RNAtabupath with other algorithms to compute low energy folding pathways between experimentally known structures of several conformational switches. The RNApathfinder web server, source code for algorithms to compute and analyze pathways and supplementary data are available at http://bioinformatics.bc.edu/clotelab/RNApathfinder.
Expectations and learning in Iowa

We study the rationality of learning and the biases in expectations in the Iowa Experimental Markets. Using novel tests developed in (Bossaerts, P., 1996. Martingale restrictions on equilibrium security prices under rational expectations and consistent beliefs. Caltech working paper; Bossaerts, P., 1997. The dynamics of equity prices in fallible markets. Caltech working paper), learning in the Iowa winner-take-all markets is found to be in accordance with the rules of conditional probability (Bayes' law). Hence, participants correctly update their beliefs using the available information. There is evidence, however, that beliefs do not satisfy the restrictions of rational expectations that they reflect the factual distribution of outcomes.
Barium evaluation of esophageal strictures: still useful or a bust?: Gupta S, Levine MS, Rubesin SE, et al., Usefulness of barium studies for differentiating benign and malignant strictures of the esophagus. Am J Roentgenol 2003;180:737–44

Abstract The purpose of this investigation was to determine the usefulness of barium radiological studies for differentiating benign and malignant strictures of the esophagus. Esophageal radiology has proved to be a useful technique for demonstrating luminal narrowing as a cause of dysphagia, with reported sensitivities exceeding 95% for the detection of strictures 1 , 2 , 3 . In this retrospective study, a search of the radiological and endoscopic records revealed 100 patients (50 women and 50 men, mean age 61 yr) with esophageal strictures who had both examinations. Of these patients, 74 presented with dysphagia, and endoscopic tissue sampling was performed in 57. The images from the barium studies (all digital fluoroscopy) were reviewed by two GI radiologists who were blinded to the clinical, endoscopic, and pathological findings. The strictures seen on the radiological images were classified into three categories: 1) benign, 2) malignant, and 3) equivocal in appearance. The quality of the examinations was also graded; 94 patients had double-contrast studies, and the remaining six patients had only single-contrast examinations. The radiographic data were correlated with the endoscopic and pathological findings to determine the usefulness of barium studies for differentiating benign strictures from malignant tumors. Of the 100 esophageal strictures detected on barium studies, 75 strictures (75%) had a benign radiographic appearance, 11 (11%) had a malignant appearance, and 14 (14%) had an equivocal appearance. Of the 75 strictures that were presumed to be benign on radiographic examination, none had malignant tumor shown by endoscopy; 48 patients had benign strictures on endoscopy, whereas the remaining 27 patients did not show definite strictures. All 11 patients (i.e., 100%) with strictures that were presumed to be malignant on barium studies had malignant tumor on endoscopy (squamous carcinomas in five patients, adenocarcinomas in four, and other malignancies in two). Finally, 13 of 14 patients (93%) with strictures that were equivocal in appearance radiologically had benign strictures without tumor on endoscopy and one patient (7%) had esophageal carcinoma. The authors conclude that benign esophageal strictures depicted on barium examination do not warrant endoscopy to exclude malignancy. However, radiographically malignant or equivocal strictures require early endoscopy and biopsy for a definitive diagnosis.
Designing and implementing branding strategies

A key aspect of managing brand equity is the proper brand strategy. Brand names of products typically do not consist of only one name but often consist of a combination of different brand names and other brand elements. A branding strategy for a firm identifies which brand elements a firm chooses to apply across the various products it sells. This paper describes two important tools to help design and implement branding strategies — brand hierarchies and brand portfolios. Combining these tools with customer, company, competitive considerations can help a marketing manager formulate the optimal branding strategy.