cssi/SciSciGPT-SciSciNet huggingface dataset:
Biochemical studies of a human low-activity galactose-1-phosphate uridyl transferase variant.

A low activity galactose-1-phosphate uridyl transferase (transferase) variant in a newborn infant has been demonstrated by biochemical studies in erythrocytes and cultured skin fibroblasts. The newborn infant was a galactosaemic suspect identified in a neonatal metabolic screening programme. On breast feeding, he did well without clinical symptoms of galactosaemia during the first 15 days of life. However, substantial amounts of erythrocyte galactose-1-phosphate and urinary galactitol corresponding to the levels in untreated galactosaemic patients, along with mild amino aciduria, were found. The transferase activity, as measured by a sensitive micro kinetic radioisotopic method, was about 7–10% of the normal. On starch gel electrophoresis, the enzyme from the haemolysate had similar mobility as the normal in Tris-glycine buffer, pH 8.8 and phosphate buffer, pH 7.0, but had a slower mobility than that of the normal in the histidine buffer, pH 7.8. The mobility difference was much clearer in a semipurified enzyme preparation. The transferase enzyme in the haemolysate appeared to be more heat labile.
Self-Interest and Altruism in Intergenerational Relations *

Self-interest and altruism in the relationships between generations can be manifested both within the family and in the public arena. The present study compares levels of support between age groups 40-49,50-59, 60-69, 70-79, and 80+ on a series of attitudes about “appropriate” parent-child relations and governmental programs for older people. On both kinds of measures, older people tend consistently to be least likely to adopt the “pro-elderly” position. This association is maintained when controls are introduced in multivariate analyses. Altruism, not self-interest, seems to govern the attitudes of the older generation in this sample. This finding should mitigate potential conflicts over issues of intergenerational equity and fairness, both within the family and in public policy.
The use of hypertonic saline infusions in the differential diagnosis of diabetes insipidus and psychogenic polydipsia.

OBJECTIVE methods for differentiating polyuria and polydipsia of neurohypophysial origin from psychogenic polydipsia have hitherto been limited to prolonged urine concentration tests (2), a difficult procedure to carry out in many instances because of the attendant discomfort and lack of cooperation on the part of the patient. Gilman and Goodman (4, 5) found that dehydration, as well as the oral administration of hypertonic saline, led to the appearance of an antidiuretic substance in the urine of normal, but not of hypophysectomized rats; an observation which has been confirmed in several other species of experimental animals (1, 7, 9, 11, 12, 14, 15, 16, 17). Hare and his associates in a series of studies on normal dogs (8) have shown that the concentration of chlorides in the tubular reabsorbate (R) or the ratio of R to plasma chlorides (R/P) and the urine flow, are all decreased following infusions of hypertonic saline, concomitantly with an increase of antidiuretic substance in the urine. In hypophys...
Achievement and Ascriptive Processes in the Recognition of Scientific Articles

Most studies in the sociology of science have used individuals or organizations as their units of analysis. Using scientific articles provides an alternative method for studying the distribution of recognition or influence in science. The study of citations to articles not only permits a better examination of the functionalist distinction between achievement and ascriptive processes (relying on universalistic and "Matthew effect" criteria, respectively) but also considers intellectual factors in scientific communications-some of the major concerns of the critics of functionalism. This paper develops a methodfor the study of citations and applies it to a sample of geoscience articles. The results indicate that achievement processes are more important than ascriptive processes in the distribution of scientific influence. Most research in the sociology of science has employed two principal units of analysis: individuals and organizations. But Randall Collins suggests that one might get further insight into social processes by studying more elemental units of analysis-for example, the study of conversations and discovery of the reasons that some conversations have more influence than others. Given the difficulty of such studies of everyday life, Collins proposes that the scientific community has several advantages for micro-level analysis: scientific articles are obvious micro-units of analysis, which are analogous to conversations; articles are available for public inspection; they constitute a key element in gaining scientific influence; and citations to articles provide a measure of their influence on others. This paper illustrates how an article level of analysis can provide a valuable supplement to our knowledge about the distribution of influence in science. The first section of this paper outlines the functionalist perspective in the sociology of science (Merton, a) and suggests how two of the pro
Influence of cycles of high and low turbulent shear on the growth rate and equilibrium size of mud flocs

Abstract Effects of repeated exposure to multiple cycles of high and low turbulent shear on mud floc growth pattern and equilibrium size were investigated through a laboratory study. The specific research questions examined were: (1) do repeated cycles of floc growth and breakup change the equilibrium floc size from one cycle to the next?; and (2) do these repeated cycles impact the floc growth rate and path to equilibrium? For the experiments, a 50 mg/l mixture of kaolinite and montmorillonite clay was sonicated and introduced to a mixing chamber to allow for flocculation under a mean turbulent shear rate of G = 35 s− 1. Floc size time series, floc circularity index, and time series of the number of flocs were measured using a camera system and image processing routines. After the flocs reached an equilibrium size, the floc suspension was broken down with vigorous turbulent mixing (G = 400 s− 1) for 15 h. Flocs were then allowed to regrow at a shear rate of G = 35 s− 1. This procedure was repeated seven consecutive times. The data show that the different initial particle size distributions after sonication and after intense shearing had almost no effect on the equilibrium floc size, but that difference in initial size did significantly impact the floc growth pattern before the equilibrium was reached. With each repeated floc breakup and growth cycle, the rate of floc growth decreased. Each of the seven regrowth cycles was modeled with the Winterwerp (1998) equation for the mean floc size by calibrating the collision and breakup efficiency coefficients for each cycle. To obtain a good fit to the data, both the collision and breakup efficiency coefficients had to be reduced with each successive cycle. The observations and modeling results suggest that flocs become slightly stronger and less reactive with each repeated cycle of growth and breakup. The consistency of the equilibrium floc size in the experiment suggest that given enough time, floc settling velocity maybe reasonably modeled as a function of local conditions. However, if the time it takes to reach equilibrium is larger than the time scale of the flow of interest, then the floc settling velocity may be difficult to define without knowledge of the turbulent shear conditions encountered prior to the point of analysis; even when using a size evolving floc modeling approach.
The hairless promoter is differentially regulated by thyroid hormone in keratinocytes and neuroblastoma cells

The hair cycle is an extraordinarily complex process relying on spatially and temporally coordinated integration of intercellular signaling, cell division and death, cell migration, and gene expression. The hairless gene (hr) is expressed with hair-cycle-dependent kinetics, and pathogenic mutations in hr are responsible for the hairless and rhino phenotypes in mice and atrichia with papular lesions in humans. In addition to its expression in the skin and hair follicle, hr is also highly expressed in the brain, yet the factors governing its differential cell-type-specific expression have not yet been defined. A thyroid hormone responsive element was previously identified in the rat hr promoter which confers thyroid hormone (T3) responsiveness to heterologous promoter constructs; however, prior studies have not focused on the hr promoter itself. The hairless promoter was cloned, and it is shown that the hr promoter is transactivated by T3 in neuroblastoma cells but not in keratinocytes. Therefore, while T3 has a significant role in the regulation of neuronal expression of hairless, its upregulation in keratinocytes is T3 independent. Furthermore, hr is subject to cell-type-specific negative autoregulation, inhibiting the activity of its own promoter in keratinocytes but not neuroblastoma cells. These findings illustrate a molecular distinction between the regulation of hr expression in defined cell populations.
Involvement of deoxyribonuclease activity in the differential sedimentation rates of nucleoids from non-transformed and transformed mouse embryo fibroblasts.

Abstract Lysis of non-transformed confluent C3H10T1/2C18 mouse embryo fibroblasts in the presence of detergents, high concentrations of salt and EDTA on top of neutral sucrose gradients revealed a reduced sedimentation rate of the resulting nucleoids from these cells compared to those from exponentially growing non-transformed cells or from transformed cells. Exposure of confluent cells to 1000 rads of X-ray had no effect on this rate of nucleoid sedimentation; and ethidium bromide tritration and alkaline sucrose analysis suggested the presence of discontinuities in the DNA. An endocnucleolytic activity could be extracted from nuclei of these cells with 0.5 M NaCl, indicating a very tight association with the chromatin. Such an enzyme in non-transformed confluent cells may account for the differences in nucleoid structure and may be related to changes in cell function with normal arrest of cell growth. There was no growth-phase effect on the properties of nucleoids from transformed cells.
Nonlinear time perception.

Abstract Sensitivity to time was investigated to test the linear-timing hypothesis. A long duration was adjusted until accuracy was 75% correct for a short duration in a two-choice procedure. Short durations (2, 4, 6, 8, 10, 12, 14, 16 and 18 s) were selected from previous research that suggests that sensitivity to time is nonlinear in this range. Rats were tested with a single short interval (Experiment 1, n=13) or a random order (Experiment 2, n=7). A local maximum in sensitivity (d' from signal detection theory) was observed at approximately 8–12 s. Sensitivity to time was reliably correlated (r's=0.759–0.941) with previous data. Weber fractions exhibited a U-shape and were negatively correlated with sensitivity to time (r=−0.800). These results provide additional evidence that sensitivity to time is nonlinearly related to physical time.
Synthesis and characterization of dimethacrylates containing quaternary ammonium functionalities for dental applications.

Abstract Objectives The widespread incidence of recurrent caries highlights the need for improved dental restorative materials. The objective of this study was to synthesize low viscosity ionic dimethacrylate monomers (IDMAs) that contain quaternary ammoniums groups (antimicrobial functionalities) and are compatible with existing dental dimethacrylate-based monomers. Such monomers have the potential to copolymerize with other methacrylate monomers and produce antibacterial polymers. Methods Two monomers (IDMA-1 and IDMA-2) were synthesized using the Menschutkin reaction and incorporated at 0–30% (by mass) into a 1:1 (by mass) bisphenol A glycerolate dimethacrylate (BisGMA):triethylene glycol dimethacrylate (TEGDMA) resin. Resin viscosity was quantified using rheology, and polymer degree of conversion (DC) and surface charge density were measured using Fourier transform infrared spectroscopy (FTIR) and fluorescein binding, respectively. Effects of IDMA-1 on initial attachment of Streptococcus mutans and on viability and metabolic activity (via reductase enzymes) of RAW 264.7 macrophage-like cells were quantified. Results IDMA-1 and IDMA-2 were prepared and characterized. IDMA-1 was miscible with BisGMA:TEGDMA and slightly increased the resin viscosity and DC. As expected, polymeric surface charge density increased with increasing IDMA-1. Incorporation of 10% IDMA-1 into BisGMA:TEGDMA reduced bacterial colonization without affecting viability or metabolic activity of mammalian cells. Increasing IDMA-1 up to 30% had no additional effect on bacterial coverage, but ≥20% IDMA-1 significantly reduced macrophage density, viability, and metabolic activity. Leachables from polymers containing IDMA-1 were not cytotoxic. Significance The Menschutkin reaction provides a facile, convenient means to synthesize new monomers with quaternary ammonium groups for dental and medical applications.
Financing Public Education and the Property Tax

THIS PAPER BRIEFLY EXPLORES the American historical background of the property tax and the financing of elementary and secondary public education. The close relationship of the two is demonstrated to have been a happenstance, but one that has had a very important effect on both the American development of primary and secondary education and the administration of the property tax. It is against this background that today's conditions are examined to establish education and property tax trends. Finally this base is utilized to develop an integrated program of education financing and policy-making.
On Free Food for Millionaires

and Blanca are pursuing has its drawbacks: "Graduate, get a good job, save, buy house but those ways were slow. And like Nazario's and Bodega's ways, they held n guarantees of success just because they were legal. They, too, were gambles, olls of the di " (p. 160). With these passa es, Quinonez skillfully reminds the reader of the uncertainty that characterizes life in low-income neighborhoods like East Harlem. Illegal pursuits might be dangerous for the individual, or harmful to the community, but the prescribed ladder to upward mobility looks awfully rickety from where Chino stands. Nazario has combined both approaches, and is leaning on Chino to do the same. Chino comes of age when he stands face to face with Nazario and makes his choice.
A PC- and lotus-based data acquisition/reduction system for an ICP spectrometer

Abstract Three new Lotus macro programs have been written to automate interfacing and data acquisition, data-file creation, and analytical drift correction for the output of an inductively coupled plasma (ICP) spectrometer. These programs, in conjunction with an IBM-compatible PC, collectively represent a low-cost alternative or supplement to commercial data stations. Although primarily intended to facilitate reduction of research-related data, the drift-correction macro is useful also as a pedagogical aid in teaching instrumental geochemical analysis. The three macro programs are described in sufficient detail to facilitate adaptation for use with diverse analytical instrumentation.
Restructuring socialist housing estates and its impact on residents’ perceptions: “Renovatsiia” of khrushchevki in St. Petersburg, Russia

This paper explores the issue of restructuring socialist housing estates in St. Petersburg, Russia, with an emphasis on residents’ perceptions of the wide range of economic, social, and environmental impacts of that restructuring. A new housing renewal program, “renovatsiia” (renovation) of khrushchevki, has been controversial from the very beginning and involves the demolition of existing khrushchevki and the construction of new housing on the same sites. By examining the issue within the framework of housing regeneration in the post-socialist context, the paper aims to provide insights into some of the challenges of urban renewal in the housing sector in the second largest Russian city. The paper at the same time investigates the viability of the collaborative planning model in the context of the post-socialist city.
Synthesis of a New EPM-Polystyrene Graft Terpolymer

An EPDM graft terpolymer was prepared using the macromer polystyryldicyclopentadiene (PSt-DCp). Terpolymerization of PSt-DCp with ethylene and propylene led to a new material containing five branches per chain. The terpolymer was characterized by GPC, osmometric measurements, and NMR spectroscopy.
Separation of some enantiomeric di- and tripeptides on chiral stationary phases

The chromatographic behavior of the N-3,5-dinitrobenzoyl derivatives of twelve dipeptide esters and two tripeptide esters was investigated on three different chiral stationary phases (CSPs). It is observed that the stereoisomers present in each sample may be cleanly separated on each chiral phase. A degree of regularity is noted in the elution order of the enantiomers and often of the diastereomers. Elution order of the enantiomers is related to a chiral recognition model for each CSP.
Misalignment-Tolerant Spot-Size Converter for Efficient Coupling Between Single-Mode Fibers and Integrated Optical Receivers

We design a spot-size converter (SSC) on silicon-on-insulator (SOI) platform to interface an integrated optical receiver (IOR) with a single-mode fiber (SMF). Because of the capability of coupling higher order modes by the proposed device, the tolerance of fiber-to-waveguide misalignment is much improved. The concept is suitable for receivers consisting of multimode-compatible components such as the echelle grating demultiplexer and the Ge waveguide photodetector.
Pushing and Pulling: Microtubules Mediate Meiotic Pairing and Synapsis

Meiotic pairing in the nematode Caenorhabditis elegans is facilitated by chromosomal sites known as pairing centers that are tethered to the nuclear envelope. Sato et al. (2009) and Penkner et al. (2009) provide insight into how proteins linking pairing centers and the microtubule cytoskeleton mediate homolog pairing and restrict synapsis to homologous pairs of chromosomes.
Smoking Prevention in Childhood Cancer Survivors

In the year 2000, there may be 220,000 adult survivors of childhood cancer. This creates new emphasis on the health of long-term survivors. The oncology team is responsible for educating patients about methods of modifiable risk reduction for the development of cancer. Smoking is the single most avoidable risk factor implicated in the development of cancer, yet survivors of childhood cancer have been found to smoke at the same rate as their peers. Nurses play a key role in developing patients' knowledge, beliefs and skills to avoid smoking behaviors.
Occupancy and detection of benthic macroinvertebrates: a case study of unionids in the lower Flint River, Georgia, USA

AbstractPresence/absence sampling designs are commonly used approaches for documenting the occurrence of benthic invertebrates, but these methods often provide biased indices of occupancy or abundance. Unionids are particularly susceptible to bias associated with nondetection because of their generally low abundance and burrowing behavior. We present a case study in which we used an occupancy-modeling approach that incorporates estimation of detection probability to assess the occurrence of unionids at 39 locations along a 119-km reach of Flint River, Georgia. We fitted models relating site- and reach-level variables to detection and occupancy for 3 species of conservation concern and contrasted inferences drawn between models accounting for variable imperfect detection and models assuming constant imperfect detection. We collected 20 unionid species among 39 sites. Among species, detection probabilities averaged 0.25 and ranged from 0.01 to 0.69, and estimated occupancy averaged 0.56 and ranged from 0.03...
Molecular cloning and regional distribution of rat brain cyclophilin

Abstract Cyclosporine A (CsA) is a potent immunosuppressive drug that has widespread clinical uses in organ transplantation and the treatment of autoimmune disorders. However, the drug's clinical applications are on an empiric basis with a poor understanding of the basic mechanism(s) of action. CsA may exert some of its effects by binding to a cellular receptor protein — the cyclosporine receptor (also called cyclophilin). Cyclophilin (CyP) is an ubiquitous, soluble, cytoplasmic 17 kDa protein which has recently been shown to be a peptide-prolyl isomerase. CsA specifically binds to this protein and inhibits its isomerase activity. A rat cyclophilin cDNA clone was isolated from a rat brain lambda gt11 cDNA library. Northern blot analysis shows a single a single 1 kb messenger RNA in rat brain. In order to determine the regional distribution of the Cyp mRNA in situ hybridization was performed. The Cyp mRNA appeared to be expressed throughout the brain but there were particularly high levels in the cerebral cortex and hippocampus compared to the relatively low levels in white matter areas and tracts. At the cellular level, the Cyp mRNa is expressed at much higher levels in neurons than in glia. The high levels of Cyp in cortical (neuronal) areas may, in part, explain the global encephalopathic symptoms clinically observed in CsA neurotoxicity.
Silicon photonics: Nonlinear optics in the mid-infrared

Carefully designed nanophotonic silicon waveguides, when pumped at long wavelengths to avoid inherent losses, are opening the door to useful nonlinear processes in the mid-infrared.
Immunoaffinity purification of the RAP30 subunit of human transcription factor IIF.

RAP30, an RNA polymerase-associated protein (RAP) of approximately 30 kDa, is a component of the eukaryotic general transcription factor IIF (TFIIF). We have isolated a monoclonal antibody (MAb) that can be used to purify RAP30 under nondenaturing conditions. This MAb (designated 1RAP1) is a unique type of MAb that we have designated "polyol-responsive MAb." Polyol-responsive MAbs are high-affinity antibodies that release antigen in a buffer containing a low-molecular-weight polyhydroxylated compound (polyol) and a nonchaotropic salt. RAP30, contained on pET11d, was expressed in Escherichia coli by culturing and inducing protein expression at 26 degrees C. Under these conditions, approximately 50% of the RAP30 remains soluble. Inclusion bodies were removed from the cell lysate by centrifugation, the supernatant was treated with polyethyleneimine at 0.5 M NaCl to remove nucleic acids, and the soluble protein was applied directly to MAb-conjugated Sepharose. After extensive washing, RAP30 was eluted with buffer containing 0. 75 M ammonium sulfate and 40% propylene glycol. RAP30 produced by this procedure stimulates transcription from a minimal promoter. This is a rapid method for purifying unmodified RAP30 without renaturing the protein from inclusion bodies.
Alcohol and hepatitis C: Implications for disease progression and treatment

Patients with chronic hepatitis C are counseled by their physicians to abstain from alcohol intake. This recommendation is based on multiple epidemiologic studies showing that heavy alcohol intake correlates with worse hepatitis C virus-associated liver disease, as well as published international consensus guidelines. It is also logical, because alcohol intake is likely second only to hepatitis C as a cause of liver disease in the Western world. Abstaining from alcohol removes a major hepatotoxin. When one evaluates critically what has been clearly demonstrated about the relationship between hepatitis C and alcohol, however, the data remain limited. Heavy alcohol intake in association with chronic hepatitis C has been shown unequivocally, at a patient population level, to lead to worse liver disease. The role of light alcohol intake on disease remains controversial. Alcohol has been linked to the development of hepatocellular carcinoma, likely substantially through its role in the development of cirrhosis. Alcohol use also seems to lead to diminished response to interferon-based treatment of hepatitis C, although whether this is a direct effect is not known.
Comment: Making a case for seeing more cases but not a case for more case logs.

Albert et al.1 examined the relationship between number of cases encountered by medical students in a 1-week outpatient component of a 4-week neurology clerkship and performance on the National Board of Medical Examiners Neurology Subject Examination and an objective standardized clinical examination (OSCE). They found a significant correlation between the number of outpatients logged and scores on the subject test and written component of the OSCE. These findings contrast with those of Poisson et al.,2 who found no correlation between number of patients logged and final clerkship performance or total written examination scores, and a negative correlation between number of patients seen in diagnostic categories and test disease category subscores.
Hypothesis Tests for Markov Process Models Estimated from Aggregate Frequency Data

Abstract When the only data available for estimating the transition probabilities of a Markov chain are state occupation frequencies (rather than interstate transition frequencies), a least squares estimation technique and an accompanying hypothesis-testing methodology are proposed. This general hypothesis-testing procedure is used to develop three tests for adequacy of the simple stationary model. Null hypotheses of a zero-order process, stationarity, and homogeneity are considered. The distributions of the test statistics are investigated in a factorially designed Monte Carlo study. In general, it is found that treating the test statistics as having F distributions with appropriate degrees of freedom under the null hypothesis of interest leads to rejection proportions close to the desired levels. Additional Monte Carlo results indicate favorable power of the proposed tests.
Assessing the performance of construction projects: Implementing earned value management at the General Services Administration

There are many potential measures of performance for evaluating the success of a construction project. All address performance in three key areas: scope, schedule and budget. In a performance measurement framework where senior management wishes to minimise the numberof performance measures it employs, while ensuring maximal coverage or visibility into the programme, having a tool that captures each of the three areas would be ideal. Project managers have used Earned Value Management (EVM) for over 40 years to track actual schedule progress and actual costs against project plans. Earned Value Management has traditionally been applied to individual projects on which the manager is accountable for both schedule and cost variances. This paper proposes methods to apply EVM principles to allow: (1) analysis of portfolios of construction projects; (2) incorporation of the analysis into an innovative pay‐for‐performance human resources practice; and (3) use of regression analysis to develop baseline earned value ...
Global convergence of a semi-infinite optimization method

A new algorithm for minimizing locally Lipschitz functions using approximate function values is presented. It yields a method for minimizing semi-infinite exact penalty functions that parallels the trust-region methods used in composite nondifferentiable optimization. A finite method for approximating a semi-infinite exact penalty function is developed. A uniform implicit function theorem is established during this development. An implementation and test results for the approximate penalty function are included.
CRYSTAL CHEMISTRY AND ENERGETICS OF PHARMACOSIDERITE-RELATED MICROPOROUS PHASES IN THE K2O-CS2O-SIO2-TIO2-H2O SYSTEM

Abstract A complete series of solid solutions with compositions (K1−xCsx)3Ti4Si3O15(OH) · nH2O (n=4–6, 0⩽x⩽1) and having the pharmacosiderite structure (space group P 4 3m) has been synthesized using hydrothermal and ion-exchange methods. Rietveld analysis of synchrotron XRD data shows that the unit-cell parameter a increases linearly with increasing Cs+ content. In the structure, K+ is situated in the center of the eight-membered titanosilicate ring, whereas Cs+ is displaced from the ring center, and the displacement increases with higher K+/(Cs+ + K+) ratio. The enthalpies of formation from the oxides and from the elements were determined by drop solution calorimetry into molten 2PbO · B2O3 solvent at 974 K. The formation enthalpies from oxides become more exothermic with increasing Cs+/(Cs+ + K+), suggesting a stabilizing effect of K+ → Cs+ on the pharmacosiderite structure. Calculation of the enthalpy of the K+ → Cs+ exchange reaction based on the measured formation enthalpies indicates that the Cs+ uptake in these phases is probably thermodynamically (rather than kinetically) driven.
Crumbs from the crust of Vesta: Achondritic cosmic spherules from the South Pole water well

Ten glass cosmic spherules (CS) from the South Pole water well collection were analyzed by electron microprobe. Nine of them have Fe/Mn and Fe/Mg ratios in the range typical of chondrites. One of them (SP37-3), along with up to six other previously analyzed CS, have nonchondritic Fe/Mn and Fe/Mg ratios that agree well with values typical of either (basaltic) howardite, eucrite, and diogenite (HED) meteorites or Martian basalts, but not of lunar samples. SP37-3 also contains an anorthite relic grain. Anorthite has not previously been reported in cosmic spherules, but is well known in HED meteorites. The much greater frequency of HEDs among hand-sized meteorites suggests but does not prove that HED precursors are more likely for the nonchondritic spherules.We estimate that HED-like micrometeorites constitute 0.5 ± 0.4% of the total population of micrometeorites in the South Pole water well, a fraction that translates to a flux of 1.6 ± 0.3 x 10^(-8) g HED micrometeorites/m^2-y. The ratio of HED-like objects to carbonaceous objects is about 100 times less in micrometeorites than among hand-size specimens. We infer that the comparative mechanical weakness of carbonaceous precursor materials tends to encourage spherule formation.
Collaborative diffusion: programming antiobjects

Object-oriented programming has worked quite well - so far. What are the objects, how do they relate to each other? Once we clarified these questions we typically feel confident to design and implement even the most complex systems. However, objects can deceive us. They can lure us into a false sense of understanding. The metaphor of objects can go too far by making us try to create objects that are too much inspired by the real world. This is a serious problem, as a resulting system may be significantly more complex than it would have to be, or worse, will not work at all. We postulate the notion of an antiobject as a kind of object that appears to essentially do the opposite of what we generally think the object should be doing. As a Gedankenexperiment antiobjects allow us to literally think outside the proverbial box or, in this case outside the object. This article discusses two examples, a Pacman game and a soccer simulation where antiobjects are employed as part of a game AI called Collaborative Diffusion. In Collaborative-Diffusion based soccer the player and grass tile agents are antiobjects. Counter to the intuition of most programmers the grass tile agents, on top of which all the players are moving, are doing the vast majority of the computation, while the soccer player agents are doing almost no computation. This article illustrates that this role reversal is not only a different way to look at objects but, for instance, in the case with Collaborative Diffusion, is simple to implement, incremental in nature and more robust than traditional approaches.
Barefoot-Pedestrian Tribometry: In Vivo Method of Measurement of Available Friction between the Human Heel and the Walkway

We have developed an in vivo tribometer for characterizing the friction of a human heel against a planar test surface. The pedestrian steps down on an angled test surface and an observer determines if the person's heel slips. In the simplest variation, the subject simply steps down onto the test surface. The second variation has the standing subject's lower leg constrained to a vertically running carriage, forcing the pedestrian's leg to descend vertically. The third variation has the subject sitting, with an operator raising and lowering the carriage to which the leg is attached. The test surface was fixed at a given angle, a set of repeated tests was run, and the number of tests and slips were recorded. The test-surface angle was incremented through a range that varied from no slips to all slips. We analyzed the data using logistic regression. We found that the unconstrained test subject's logistic-regression curves varied greatly from subject to subject. The standing, constrained subjects were significantly closer to each other, but at the expense of a much higher spread of the angular range. The seated, constrained test subject's results were both extremely close and had extremely low angular spread.
Impact of service attributes on customer satisfaction and loyalty in a healthcare context

– The purpose of this paper is to examine the role of perceived service attributes in the development of overall customer satisfaction (OCS) and customer loyalty (CL) in a health-care setting. This paper also sheds light on the role of hospitalist physicians (HPs) and offers suggestions to improve patient satisfaction and loyalty. , – A telephone survey was used to collect data from recently hospitalized patients with respect to their HP. Structural equations modeling (SEM) was used to confirm the overall relationships between perceived service quality (PSQ), OCS and CL. The sample was then divided into customer relationship groups (CRGs) based on satisfaction and loyalty measures. Discriminant analysis was used to determine which attributes differentiated most between high and low satisfaction and loyalty groups. , – Overall relationships among PSQ, OCS and CL were in conformity with the conceptual model. Findings also revealed that service attributes played an important role in distinguishing between high and low satisfaction and loyalty groups, although some attributes were more important than others and different attributes emerged as being key influencers for satisfaction and loyalty. , – The conceptual model used is a fairly straight forward model, and we have not considered the impact of individual factors such as expectations and value perceptions or involvement levels and demographic characteristics on service quality and overall satisfaction. The data for this study were provided by a major health maintenance organization (HMO), and there is room for improvement in the manner in which certain constructs were measured. For example, OCS, recommendation and retention all used single item measures, and it might have been preferable to use multiple item measures for these constructs. , – The study shows that organizations can benefit by identifying and focusing on critical attributes as part of their customer relationship management program. , – The SEM results provide strong support for the overall model linking service quality, OCS and CL in a health-care setting. As one would expect, PSQ has a strong impact on OCS, which, in turn, has a fairly strong impact on CL. However, there is also a significant direct linkage between PSQ and CL. This linkage shows that at least a certain portion of CL could evolve independent of the satisfaction level with the HP. This shows that, in addition to trying to improve satisfaction, organizations should also explore influencing loyalty directly, perhaps by the strategic use of service attribute perceptions. , – The study shows that customer perceptions at the service attribute level can often be the key to the generation and management of customer satisfaction and loyalty. It also has significance for how satisfaction and loyalty with HPs can be improved in a hospital setting.
Electric and magnetic susceptibilities and shielding factors for closed-shell atoms and ions of high nuclear charge

Theoretical expressions for the electric and magnetic susceptibilities and shielding factors of closed-shell atoms and ions are derived from the point of view of the relativistic random-phase approximation. These expressions are evaluated to determine electric-dipole, electric-quadrupole, and magnetic-dipole susceptibilities, and shielding factors for ions of the noble-gas isoelectronic sequences, as well as for selected ions having closed $s$, $d$, and $f$ shells. Comparisons are given with previous theoretical work and with experiment.
Going beyond demographic characteristics in arthritis research: reflections on process in the experience of arthritis.

When the disease began I didn't know what it was. I was sitting at a sewing machine for forty hours a week. I was thinking of taking off some time and having it checked out but the kind of job I did have, there wasn't any coverage, no insurance or anything, so if I did leave I would lose the income. It wasn't a big-paying job. I make $150 per week, and take home $130, so I have to be careful and take in the forty hours in order to come home with something. I was turned down for disability (1).
Synthesis and characterization of polyiminobenzothiazoles

A series of polyiminobenzothiazoles was synthesized by the polymerization of either 2,6-dichloro- or 2,6-diphenoxybenzobisthiazole with a number of aromatic diamines. A polymer was also obtained from the self-condensation of either 2-chloro- or 2-phenoxy-6-aminobenzothiazole. The polymers were characterized by their elemental analysis and infrared spectra. Thermogravimetric analysis, differential thermal analysis, and softening under load were used to evaluate their thermal properties. The polymers were found to be light tan to brown powders which showed only slight softening below their decomposition temperatures. Onset of breakdown under thermogravimetric analysis in a nitrogen atmosphere generally occurred at 375–400°C. The polymers were sparingly soluble in organic solvents and had inherent viscosities in the range of 0.11–0.55.
GEOGRAPHIC DATABASE FOR TRAFFIC OPERATIONS DATA

State Transportation Departments nationwide manage huge amounts of information. Examples include geometric plans, sign inventories, maintenance records, engineering studies, and so on. In many cases, no indexing or archiving system is available for storing and retrieving this data. A prototype computer-based model was developed in order to address these indexing needs. The model focuses on engineering report tracking but can be extended to accommodate other types of information. The model is based on a procedure that links signalized intersections and road segments to nonspatial attribute data in a Geographic Information System (GIS) environment. A paper form was developed in order to facilitate the extraction of data from engineering reports. The indexing model also includes a computerized version of the paper form to assist in data entry, and another form for query purposes. The indexing model was applied to 10 years of engineering report data from East Baton Rouge Parish, La.
The VORTEX document preparation environment

VORTEX (Visually-ORiented TEX) is a TEX-based document preparation environment being developed at Berkeley. The system will have three major features: (1) Both source and target representations of a document will be maintained and displayed. Changes made to one representation will propagate to the other automatically. (2) It will reformat and redisplay a document incrementally. (3) A high degree of interactivity and a good user interface will be provided. Our approach is to derive an internal representation based on which transformations between source and target can be realized efficiently. This paper describes the objectives and motivations of the project. An outline of the internal representation as well as VORTEX's basic functionalities and user interface is presented.
Change in net primary production and heterotrophic respiration: How much is necessary to sustain the terrestrial carbon sink?

In recent years, the chief approaches used to describe the terrestrial carbon sink have been either (1) inferential, based on changes in the carbon content of the atmosphere and other elements of the global carbon cycle, or (2) mechanistic, applying our knowledge of terrestrial ecology to ecosystem scale processes. In this study, the two approaches are integrated by determining the change in terrestrial properties necessary to match inferred change in terrestrial carbon storage. In addition, a useful mathematical framework is developed for understanding the important features of the terrestrial carbon sink. The Carnegie-Ames-Stanford Approach (CASA) biosphere model, a terrestrial carbon cycle model that uses a calibrated, semimechanistic net primary production model and a mechanistic plant and soil carbon turnover model, is employed to explore carbon turnover dynamics in terms of the specific features of terrestrial ecosystems that are most important for the potential development of a carbon sink and to determine the variation in net primary production (NPP) necessary to satisfy various carbon sink estimates. Given the existence of a stimulatory mechanism acting on terrestrial NPP, net ecosystem uptake is expected to be largest where NPP is high and the turnover of carbon through plants and the soil is slow. In addition, it was found that (1) long-term, climate-induced change in heterotrophic respiration is not as important in determining long-term carbon exchange as is change in NPP and (2) the terrestrial carbon sink rate is determined not by the cumulative increase in production over some pre-industrial baseline, but rather by the rate of increase in production over the industrial period.
Differential diagnosis of renal tumours with clear cell histology

Clear cell renal cell carcinoma is the most common malignant renal epithelial tumour and constitutes 90% of cases that metastasise. Nevertheless, it is important to recognise that not all clear cell carcinomas contain a preponderance of clear cells and that other renal tumours with different biologies and sensitivities to systemic therapeutic agents may exhibit clear cell cytology. Close attention to the cytological and growth pattern characteristics will allow us to arrive at the proper diagnosis, sometimes with the aid of immunohistochemistry.
A macro approach to estimating correlated random variables in engineering production projects

An important consideration in cost risk analysis is the amount of correlation between different cost elements. If correlation is ignored, both the probability and magnitude of costs overruns could be significantly underestimated. The two major difficulties in implementing correlation addressed are estimating correlation coefficients and providing an accurate theoretical risk analysis approach to account for these correlations. Since detailed correlation data are often difficult or impossible to obtain, an intuitive approach is proposed, which estimates correlations for cost estimates relative to several underlying macro factors. The correlation matrix obtained by this method is positive semi‐definite and a case study based upon three macro factors is given. The cost risk distributions are computed and compared using the beta fit model and two other more complicated models. This study shows negligible differences in cost risk dollars when computed by the various models. This method of using macro factors t...
A Unified Procedure for Continuous-Time and Discrete-time Root-Locus and Bode Design

As an alternative to the numerous distinct controller design algorithms in continuous-time and discrete-time classical control textbooks, a simple, unified design approach is presented for all standard continuous-time and discrete-time, classical compensators that is independent of the form of the linear system information. This approach is based on a simple root locus design procedure for a proportional-derivative (PD) compensator. From this procedure, design procedures for unified notation lead, proportional-integral (PI), proportional-integral-derivative (PID), and Pi-lead compensator are developed. The delta operator, which serves as a link between the continuous-time and discrete-time procedures, offers improved numerical properties to the traditional discrete - time shift operator. With this proposed approach, designers can concentrate on the larger control system design issues, such as compensator selection and closed-loop performance, rather than the intricacies of a particular design procedure.
Enrichment of Enhanced Assumed Strain Approximations for Representing Strong Discontinuities : Addressing Volumetric Incompressibility and the Discontinuous Patch Test

SUMMARY We present a geometrically nonlinear assumed strain method that allows for the presence of arbitrary, intra-finite-element discontinuities in the deformation map. Special attention is placed on the coarsemesh accuracy of these methods and their ability to avoid mesh locking in the incompressible limit. Given an underlying mesh and an arbitrary failure surface, we first construct an enriched approximation for the deformation map with the nonlinear analogue of the extended finite element method (X-FEM). With regard to the richer space of functions spanned by the gradient of the enriched approximation, we then adopt a broader interpretation of variational consistency for the construction of the enhanced strain. In particular, in those elements intersected by the failure surface, we construct enhanced strain approximations which are orthogonal to piecewise-constant stress fields. Contrast is drawn with existing strong discontinuity approaches where the enhanced strain variations in localized elements were constructed to be orthogonal to constant nominal stress fields. Importantly, the present formulation gives rise to a symmetric tangent stiffness matrix, even in localized elements. The present modification also allows for the satisfaction of a discontinuous patch test, wherein two different constant stress fields (on each side of the failure surface) lie in the solution space. We demonstrate how the proposed modifications eliminate spurious stress oscillations along the failure surface, particularly for nearly incompressible material response. Additional numerical examples are provided to illustrate the efficacy of the modified method for problems in hyperelastic fracture mechanics. Copyright c � 2000 John Wiley & Sons, Ltd.
Limited Liver Resection: A Good Indication for the Treatment of Hepatocellular Carcinoma in Elderly Patients

Objective: Hepatocellular carcinoma is often diagnosed in elderly people. Methods: One hundred and seventy-five patients older than 70 years were operated on for hepatocellular carcinoma (Group 1). The results were compared with 276 resected patients younger than 70 (Group 2) and to 108 aged patients with chronic liver disease without hepatocellular carcinoma (Group 3). Results: Hepatocellular carcinoma in the elderly is more frequently associated with hepatitis C virus, less frequently capsulated and less frequently diagnosed by screening programs than in young patients. After resection, no difference was noted in post-operative complications and in mortality rates (3.2%); major hepatic resection in cirrhosis carried a high risk of death (22%). Five years survival was 42%, comparable with the young surgical patients but significantly lower than the medical patients in Group 3. Recurrence of hepatocellular carcinoma was the main reason of death, but it was suitable for a radical treatment in 37.6% of cases, including surgery, with a mean survival of 31 months. Conclusions: Liver resection is a valid option for the treatment of hepatocellular carcinoma in the elderly; major resections in cirrhotic old patients must be reserved for selected cases. Recurrence may be suitable of a radical approach, including surgery.