cssi/SciSciGPT-SciSciNet huggingface dataset:
Tissue compatibility to different surfaces of dental implants: in vitro studies.

Factors affecting cell and tissue responses to dental implant biomaterials are typically characterized as spatial and temporal. Spatially, a dental implant must form an interface with both bone tissue for the development and maintenance of biomechanical stability and soft tissue for the prevention of microbial infection that can lead to peri-implantitis. There is a developing body of knowledge regarding the reactions of host tissues to implant materials, although the specific mechanisms by which these responses are not yet totally understood. From a temporal standpoint, there seems to be a sequence of events after placement of an implant that involves cell attachment, migration, and differentiation. These early wound healing responses appear to be influenced significantly by the properties of the underlying implant surface. Our laboratory has focused its attention on the first cellular event, i.e., cell attachment at the interface between bone and the implant surface. An in vitro primary cell model has been developed and used to study the influence of materials selection (Ti, Ti-6Al-4V, hydroxyapatite-like coatings), surface topography (smooth to rough), and surface chemistry (as a function of preparation treatments) on the cellular events that occur at implant surfaces. Currently, we believe that both uncoated Ti implants and those fabricated with calcium phosphate or hydroxyapatite-like coatings are capable of supporting initial cellular attachment, although they probably occur by different and incompletely understood mechanisms. The initial interactions of the host tissues with the implant surface remain key for long-term acceptance and must be understood if new generations of tissue engineered devices are to be developed and used clinically.
Effect of Different Incubation Temperatures on Mortality of Chick Embryos

Abstract IT IS a matter of common knowledge that relatively slight variations from the optimum in incubation temperature influence adversely embryonic development and hatchability. Elevation of incubation temperature above normal is more serious than depression below normal but long continued deviations in either direction often lead to poor hatches. It is desirable to know when embryonic death occurs when eggs are incubated at abnormal temperatures and the immediate causes of death, as aids in the diagnosis of the causes of poor hatches. It is also important to know whether embryos in eggs of inherently high hatchability differ in resistance to abnormal temperature from embryos in eggs of inherently low hatchability. Papers by Henderson (1930), Barott (1937), and by Taylor, Gunns, and Moses (1933) contains summaries of the voluminous literature on the effects of abnormal temperatures on early embryonic development. Henderson (1930) measured the growth in weight and nitrogen content of embryos . . .
Cyclooxygenase- and lipoxygenase-mediated DNA damage

Cancer is a disease of aging, and so with the increasing age of the US population, the incidence of cancer is also increasing. Furthermore the global burden of cancer continues to increase largely because of aging and growth of the world population together with increasing smoking rates in economically developing countries. Tumor formation is critically dependent upon two processes—initiation and progression. The initiation step is mediated by DNA damage, which causes activating mutations in proto-oncogenes and inactivation of tumor suppressor genes in many cancers. This is then thought to facilitate tumor progression and metastasis. Cyclooxygenase-2 (COX-2) is upregulated at an early stage in tumorigenesis and has been implicated as an important mediator of proliferation through the increased formation of bioactive arachidonic acid (AA) metabolites such as prostaglandin E2. Significantly, we have found that COX-2-mediated AA metabolism also results in the formation of heptanone-etheno (He)-DNA adducts. Furthermore, we showed that the He-DNA adducts arose from the reaction of DNA with the lipid hydroperoxide-derived bifunctional electrophile, 4-oxo-2(E)-nonenal (ONE). Similarly, 5-lipoxoygenase-mediated AA metabolism also results in the formation of ONE-derived DNA adducts. The resulting He-DNA adducts are highly mutagenic in mammalian cell lines suggesting that these pathways could be (in part) responsible for the somatic mutations observed in tumorigenesis. As approximately 80% of cancers arise from somatic mutations, this provides an additional link between the upregulation of COX-2 and tumorigenesis.
Serum hepatitis specific antigen (SH) in commercial and volunteer sources of blood.

Blood from various commercial sources used for transfusion at two New York City hospitals, samples from a large commercial blood bank, and samples from the city's major volunteer blood source, Were tested for SH antigen by the Ouchterlony technic. The different commercial sources averaged an antigen positive incidence of 1.2 per 100 units, whereas the volunteer source had less than one positive per thousand. The relative risk of transfusion hepatitis between the two sources was approximately 12: 1. This is in accord with follow-up studies of patients. Improvements in the sensitivity of the antigen test and exclusion of positive units would reduce the absolute risk of posttransfusion hepatitis but would not be expected to alter the relative risk. Because of this, volunteer blood sources should be considered preferable to commercial sources, at least in large urban areas.
Identification and Classification of Consumer Food-Handling Behaviors for Food Safety Education

Abstract Objective To identify key behaviors associated with major food safety pathogen control factors. Design World Wide Web-based descriptive study with 4 tasks: compile a list of food-handling behaviors from the literature; use Delphi process to build consensus, rank order, and edit lists of behaviors; assess content and construct validity; and review results of Delphi process at a summit meeting of selected experts to make final recommendations for a food safety behavior list. Subjects/setting A convenience sample of 10 epidemiologists, 11 food microbiologists, 10 food safety educators, and 10 food safety policy makers was recruited from lists of nationally known experts. Twenty-four experts completed 4 rounds of surveys presented to them via a Web site. Six experts attended a face-to-face meeting to finalize behavior lists. Statistical analyses performed Descriptive statistics and sum of observation data were used to determine rank order and validity. Results Twenty-nine key food-handling behaviors for maintaining the safety of food and reducing the number of cases and outbreaks of foodborne illness were identified. These were rank-ordered within 5 pathogen control factors: practice personal hygiene, cook foods adequately, avoid cross-contamination, keep foods at safe temperatures, and avoid foods from unsafe sources. Applications/conclusions This list of rank-ordered behaviors grouped by pathogen control factor should help dietitians and educators confidently teach food safety guidance that will be most effective in preventing illness. J Am Diet Assoc. 2001;101:1326-1332, 1337-1339.
DOSAGE EFFECTS OF THE LANCEOLATE GENE IN TOMATO

In contrast to the odd-pinnately compound leaf of the normal (+/+) tomato plant (Lycopersicon esculentumn), the single-gene mutant lanceolate (La/+) generally has a simple leaf. Lanceolate plants, also, have small fruits and flowers, weak apical dominance, and exhibit variation in the position and fusion of cotyledons. Homozygous mutants (La/La) appear in 3 different phenotypes, 1 of which, narrow, has narrow simple leaves, sterile infloreseences, and extremely weak apical dominance. The other 2, modified, and reduced, lack an organized shoot. After selfing La/ + plants for 9 generations, autotetraploids were produced with the aid of colchicine. In addition, several triploid plants arose spontaneously. The study of diploid, triploid, and tetraploid material with various proportions of the La allele revealed in many characters a graded series as a function of the La dosage. With increasing La dose, there was a gradual reduction in: (1) total leaf length; (2) the number and size of primary and secondary lateral leaflets; (3) the number and size of marginal lobes of the terminal leaflet, associated with an increase in the proportional length of the terminal leaflet. Many leaves were found with the basal lobes of the terminal leaflet resembling incompletely separated lateral leaflets. The differences in leaf shape between different genotypes came about before the leaf primordium was 3 mm long. There was a progressive delay in the initiation of lateral primordia with increasing La dosage. It is proposed that the gradual changes from compound to simple leaves with increasing La dosage are produced by successively greater restrictions of meristematic activity after the terminal leaflet is formed. With increasing proportion of La alleles, the reproductive structures showed: (1) a decrease in the number of flowers per inflorescence; (2) a decrease in the length of the sepals; (3) an increase in the proportion of flowers with dialytic anthers. Dialytic anthers had narrow adaxial lobes and were frequently twisted along their main axes. The common denominator for most trends affected by the La allele seems to be a general reduction of growth, but more so in lateral than in longitudinal growth. Histological data suggest that the reduction in lateral growth is mainly brought about by a reduction of cell division in lateral meristems.
Some Limitations of the In Vivo Fluorescence Technique

Thein vivo chlorophylla fluorescence technique for phytoplankton depends on the effective absorption and fluorescence quantum yield of chlorophylla. The range of variation in the ratio ofin vivo fluorescence: extractable chlorophylla was found to be nearly 10-fold in natural Chesapeake Bay phytoplankton populations with significant areal and seasonal differences in addition to ambient light dependent fluorescence inhibition. Diel variations in chlorophylla fluorescence ratios were found to be species specific responses of some diatom and dinoflagellate populations. Observed changes in fluorescence ratios of several natural populations from day to night levels were as great as 8-fold when diatomsCerataulina bergonii andRhizosolenia sp. dominated the phytoplankton biomass. The diel response was changes in ambient light, the Kautsky Induction Effect, were associated with the degree of nutritional stress in natural samples and in unialgal cultures of phytoplankton. These observations may serve to explain some of the variations encountered in the application of thein vivo chlorophylla fluorescence technique and to provide a basis for an assessment of the physiological conditional of natural phytoplankton populations. Differences in cellularin vivo fluorescence ratios in vertical profiles of natural populations which might have been associated with variations in species composition variation with depth were eliminated by uniform dark treatment and suggest the observedin vivo chlorophylla fluorescence is in part related toin situ adaptation to the spectral quality of ambient light.
Sharing the Financial Burden for U.N. and NATO Peacekeeping, 1976-1996

The article examines how NATO and two larger samples shared the U.N. peacekeeping financial burden from 1976 to 1996. Based on the share of gross domestic product devoted to U.N. peacekeeping, there is evidence that the rich nations are assuming a disproportionate burden of peacekeeping in the post-cold war period. This evidence is stronger for NATO than for the two larger samples. When efforts for peacekeeping not financed through the United Nations are included, the disproportionality is even clearer in the 1990s for NATO and the largest samples (accounting for 97% of U.N. peacekeeping support). Problems with alternative peacekeeping burden-sharing measures also are considered. In light of current developments, future patterns of burden sharing are anticipated, with the richer NATO allies assuming ever greater financial burdens of peacekeeping.
Developmental expression of genes for the stereoidogenic enzymes P450scc (20,22-desmolase), P450c17 (17 alpha-hydroxylase/17,20-lyase), and P450c21 (21-hydroxylase) in the human fetus

Fetal adrenal steroidogenesis is required for the production of placental estrogen, and fetal testicular steroidogenesis is required for the development of male external genitalia. We studied the ontogeny and tissue specificity of expression of the genes for three steroidogenic enzymes: P450scc (the cholesterol side-chain cleavage enzyme), P450c17 (17 alpha-hydroxylase/17,20-lyase), and P450c21 (21-hydroxylase) in the human fetus. RNA from fetal tissues was probed with homologous human P450scc, P450c17, and P450c21 cDNAs cloned in our laboratory. At 20-21 weeks gestation, P450scc mRNA was most abundant in the adrenal, followed by testis, placenta, and ovary. P450c17 mRNA was also most abundant in the adrenal, followed by testis and ovary, but was undetectable in the placenta. P450c21 mRNA was detected only in the adrenal. None of these mRNAs was detected in kidney, liver, spleen, intestine, or muscle. Twenty-two fetal testis samples (13-25.8 weeks gestation) were studied. P450scc and P450c17 mRNAs were most abundant at 14-16 weeks and diminished to 35 and 19% of their peak values, respectively, by 20-25.8 weeks. Ovarian P450scc and P450c17 mRNAs were present, respectively, in only 6.2% and 1.8% of the maximum amount in the testis and did not vary detectably from 14.9 to 21.5 weeks gestation. The testicular and ovarian steroidogenic enzyme mRNA data correlate well with previously reported changes in gonadal steroidogenesis with gestational age. The presence of P450scc mRNA, but not P450c17 mRNA, in the placenta indicates that the placenta is able to initiate the synthesis of some steroid hormones, but is not able to synthesize estrogen de novo. Since P450c21 was found only in the adrenal, the extraadrenal 21-hydroxylation of progesterone to deoxycorticosterone, a common event in the fetus, is probably mediated by an enzyme(s) other than P450c21.
Decentralization of Government Agencies: What Does It Accomplish?.

Decentralization of government has been one way of increasing government responsiveness. This is true for municipal systems where a city-wide government may be decentralized to subdistrict units as well as the federal system, where responsibilities may be delegated to state or local units. This paper reviews advantages and disadvantages of decentralized units.
Self-assembly of organic molecules on montmorillonite

Abstract Smectite clays have been modified via ion exchange reactions with organic onium ions for five decades and are of industrial importance in diverse industries including oil well drilling, paint, grease, ink, cosmetics, environmental clean-up, polymer nanocomposites and pharmaceuticals. Over the past decade, a substantial amount of research has been conducted on other methods of organic modification of smectite clays. One method that has seen increased attention is surface treatment via ion–dipole bonding of organic molecules, oligomers or polymers to the exchangeable cation on the clay surface. Utilizing this method, a unique self-assembly of certain organic molecules has been discovered in which the molecules form rigid posts around each cation on the surface. This paper reports a parametric study coupled with molecular modeling of a series of three different families of ion–dipole bonding molecules. The bonding trends and controlling factors in the self-assembly of these molecules are described in detail. In general, it appears that the head group of the molecule is one of the principal factors controlling self-assembly but the chain length of the alkyl group also plays a role.
Desorption isotherms and thermodynamics properties of anchovy in natura and enzymatic modified paste

Abstract The thermodynamic properties of anchovy fillets and enzymatic modified pastes in two hydrolysis degrees (3% HD and 14% HD), at 50, 60 and 70 °C were evaluated. The GAB model was used to calculate the values of the monolayer moisture content and the thermodynamic properties of the samples. The enzymatic modification led to the increases of the superficial area and differential enthalpies, and decrease of the differential entropies in relation the samples in natura . The enthalpy–entropy compensation showed that the process was controlled by the enthalpy, it was only spontaneous for the samples in natura . Pore size decreased with enzymatic modification, and all samples were in the limit of region between micropores and mesopores (
Neuroprotectin D1 induces neuronal survival and downregulation of amyloidogenic processing in Alzheimer's disease cellular models.

The mediator neuroprotectin D1 (NPD1) is an enzymatic derivative of the omega-3 essential fatty acid docosahexaenoic acid. NPD1 stereoselectively and specifically binds to human retinal pigment epithelium (RPE) cells and neutrophils. In turn, this lipid mediator induces dephosphorylation of Bcl-xL in a PP2A-dependent manner and induces PI3K/Akt and mTOR/p70S6K pathways leading to RPE cell survival during oxidative stress-induced apoptosis. As a proof of principle of its systemic in vivo bioactivity, NPD1 attenuates laser-induced choroidal neovascularization in mice. Using human neural cells transfected with amyloid precursor protein (APP)sw (Swedish double mutation APP695sw, K595N, M596L), NPD1 was shown to regulate secretase-mediated production of Aβ peptide, downregulates pro-inflammatory gene expression, and promotes cell survival. In human neural cells overexpressing beta-amyloid precursor protein (βAPP), the lipid mediator suppressed Aβ42 shedding by downregulating β-secretase (BACE1) while activating the α-secretase (ADAM10), thus shifting the βAPP cleavage from the noxious amyloidogenic pathway into a non-amyloidogenic, neurotrophic pathway. Furthermore, downregulation of Aβ42 peptide release by NPD1 may be dependent upon PPARγ activation. In conclusion, NPD1 exhibits anti-inflammatory, anti-amyloidogenic, and anti-apoptotic bioactivities in human neural cells in part via PPARγ signaling and through the targeting of α- and β-secretase systems.
Comparison of three models predicting developmental milestones given environmental and individual variation.

In all organisms, phenotypic variability is an evolutionary stipulation. Because the development of poikilothermic organisms depends directly on the temperature of their habitat, environmental variability is also an integral factor in models of their phenology. In this paper we present two existing phenology models, the distributed delay model and the Sharpe and DeMichele model, and develop an alternate approach, called the Extended von Foerster model, based on the age-structured McKendrick-von Foerster partial differential model. We compare the models theoretically by examining the biological assumptions made in the basic derivation of each approach. In particular, we focus on each model’s ability to incorporate variability among individuals as well as variability in the environment. When compared against constant temperaturemountain pine beetle (Dendroctonus ponderosae Hopkins) laboratory developmental data, the Extended von Foerster model exhibits the highest correlation between theory and observation.
On the formation of bottom water in the Norwegian Basin

The formation of Norwegian Basin bottom water has generally been considered to result from surface cooling during March, April, and early May followed by overturning of the water column to produce homogeneity throughout. Recent data confirm much of the earlier theory but suggest that the cooled surface water may flow toward the bottom along a gently tilted path, and that a homogeneous water column may not play any role in bottom water formation.
Circulating Tumor Cells and Melanoma Progression

Circulating tumor cells (CTCs) are cancer cells shed from either a primary tumor or its metastases that circulate in the peripheral blood. CTCs are potential seeds for metastases, and analyses of CTCs may allow earlier detection of metastasis-capable malignancy, monitoring for tumor recurrence, and accurate prognostication. Studies on CTCs have focused mainly on the detection of epithelial cancer cells. In this issue, De Giorgi et al. show that CTCs can be detected in melanoma patients using a filtration method, and that a higher percentage of patients with metastatic melanoma have detectable CTCs than do patients with primary melanoma.
The crystal structure of cesium perbromate

The crystal structure of CsBrO4 was determined by single-crystal X-ray diffraction and found to be different from the structures of the lighter alkali perbromates. Cesium perbromate crystallizes in the tetragonal space group I41/a, with unit cell constants of a = 5.751(4)A and c = 14.821(12)A. Full-matrix least-squares analyses indicate that tetrahedral perbromate ions are situated in the lattice so that all corresponding tetrahedral faces are parallel. The observed BrO distance is 1.591(6) A. The Cs+ ions reside in twelve coordinate positions with CsO distances of 3.146(7), 3.383(9), and 3.389(9) A. This unique stucture causes CsBrO4 crystals to have noticeable plasticity.
Histamine H1 receptor activation blocks two classes of potassium current, IK(rest) and IAHP, to excite ferret vagal afferents.

1. Intracellular recordings were made in intact and acutely dissociated vagal afferent neurones (nodose ganglion cells) of the ferret to investigate the membrane effects of histamine. 2. In current-clamp or voltage-clamp recordings, histamine (10 microM) depolarized the membrane potential (10 +/- 0.8 mV; mean +/- S.E.M.; n = 27) or produced an inward current of 1.6 +/- 0.35 nA (n = 27) in approximately 80% of the neurones. 3. Histamine (10 microM) also blocked the post-spike slow after-hyperpolarization (AHP slow) present in 80% of these neurones (95 +/- 3.2%; n = 5). All neurones possessing AHPslow in ferret nodose were C fibre neurones; all AHPslow neurones had conduction velocities < or = 1 m s-1 (n = 7). 4. Both the histamine-induced inward current and the block of AHPslow were concentration dependent and each had an estimated EC50 value of 2 microM. These histamine-induced effects were mimicked by the histamine H1 receptor agonist 2-(2-aminoethyl) thiazole dihydrochloride (10 microM) and blocked by the H1 antagonists pyrilamine (100 nM) or diphenhydramine (100 nM). Schild plot analysis of the effect of pyrilamine on the histamine-induced inward current revealed a pA2 value of 9.7, consistent with that expected for an H1 receptor. Neither impromidine (10 microM) nor R(-)-alpha-methylhistamine (10 microM), selective H2 or H3 agonists, respectively, significantly affected the membrane potential, input resistance or AHPslow. 5. The reversal potential (Vrev) for the histamine-induced inward current was -84 +/- 2.1 mV (n = 4). The Vrev for the histamine response shifted in a Nernstian manner with changes in the extracellular potassium concentration. Alterations in the extracellular chloride concentration had no significant effect on the Vrev of the histamine response (n = 3). The Vrev for the AHPslow was -85 +/- 1.7 mV (n = 4). 6. These results indicate that histamine increases the excitability of ferret vagal afferent somata by interfering with two classes of potassium current: the resting or 'leak' potassium current (IK(rest)) and the potassium current underlying a post-spike slow after-hyperpolarization (IAHP). Both these effects can occur in the same neurone and involve activation of the same histamine receptor subtype, the histamine H1 receptor.
Cytochrome C553 and bacteriochlorophyll interaction at 77 K in chromatophores and a subchromatophore preparation from Chromatium D.

Abstract 1. The liquid dye laser (868 nm) induced spectral changes at 77°K of Chromatium D chromatophores poised at different oxidation-reduction potentials, demonstrate that P600 is a spectral component of the reaction center bacteriochlorophyll which oxidizes cytochrome C553 ( t 1 2 = 2−2.5 msec ). At −60 mV when cytochrome C553 is chemically reduced and its photooxidation is evident, P600+ (formed in less than 0.5 μsec) is reduced over a time range similar to that of cytochrome oxidation. The photooxidation of C553 is non-reversible; a second laser pulse induces no further oxidation of cytochrome C553 or P600. At +300 mV when cytochrome C553 is chemically oxidized, reduction of the light-generated P600+ takes longer ( t 1 2 = 20–25 msec ). At −350 mV no laser-induced reactions are observed at 77°K since the primary electron acceptor of reaction center bacteriochlorophyll is chemically reduced at this potential. 2. The reactions displayed by the subchromatophore preparation are essentially the same as those of the chromatophore. The studies indicate that the membrane is not an obligatory part of the early chemical events of bacterial photosynthesis. 3. An Arrhenius plot of laser-induced cytochrome C553 oxidation suggests the existence of two modes of electron transfer from this cytochrome to bacteriochlorophyll+. 4. There were no detectable differences in the reactions studied when induced by laser light of wavelength 694 or 868 nm.
Teens in the grey zone: the structural violence of substance-using youth being raised in the system

Substance abuse is highly prevalent among youth involved in the child welfare and juvenile systems. For these youth, the need for treatment and a safe recovery environment is essential. This paper uses a structural violence approach to analyze the systems youth are involved with and the impact these systems have on achieving and maintaining healthy living placements. The analysis uses qualitative methods to explore two in-depth case studies from youth in Tucson, Arizona. Findings indicate that systems have become impotent, at times, to the point of inhibiting such recovery.
Thermodynamics of grain boundary premelting in alloys. II. Atomistic simulation

Abstract We apply the semi-grand-canonical Monte Carlo method with an embedded-atom potential to study grain boundary (GB) premelting in Cu-rich Cu–Ag alloys. The Σ 5 GB chosen for this study becomes increasingly disordered near the solidus line while its local chemical composition approaches the liquidus composition at the same temperature. This behavior indicates the formation of a thin layer of the liquid phase in the GB when the grain composition approaches the solidus. The thickness of the liquid layer remains finite and the GB can be overheated/oversaturated to metastable states slightly above the solidus. The premelting behavior found by the simulations is qualitatively consistent with the phase-field model of the same binary system presented in Part I of this work [Mishin Y, Boettinger WJ, Warren JA, McFadden GB. Acta Mater, in press]. Although this agreement is encouraging, we discuss several problems arising when atomistic simulations are compared with phase-field modeling.
The effects of non-continuum hydrodynamics on the Brownian coagulation of aerosol particles

Most theoretical predictions of the rate of Brownian-induced coagulation have considered the continuum hydrodynamic resistance of the suspending gas or liquid as well as van der Waals and/or electrostatic forces. However, the mean-free path of the gas is comparable with the length scale at which van der Waals forces become important during the collision of two Brownian aerosol particles. We predict the initial rate of coagulation in a monodisperse aerosol driven by Brownian motion in the presence of van der Waals forces and non-continuum lubrication forces when the Knudsen number (ratio of the mean-free path to the particle radius) is small but non-zero. A comparison with experiments demonstrates the accuracy of the predictions and the importance of accounting for non-continuum effects to provide quantitative predictions of coagulation rates.
A multichannel integrator and scanner for wire plane beam profile displays

Abstract A multichannel analog integrator followed by an electronic scanner routinely generates oscilloscope displays of external proton beam profiles from wire plane monitors at the Zero Gradient Synchrotron. The profiles are generated each machine cycle of the synchrotron or more frequently. Beam line monitoring is now possible by directly sensing the fundamental properties of the beam such as beam position and size. As a result, a simple, meaningful, quantitative monitoring tool is provided as an alternative to monitoring all beam transport elements.
Adequacy evaluation of fine-needle aspiration biopsy in the breast health clinic setting.

BACKGROUND Breast health clinics (BHC) are an unfamiliar source of fine-needle aspiration biopsies (FNABs) in the U.S. and create challenges for adequacy evaluation. The current study described the experience with breast FNAB adequacy evaluation over a 2-year period, the issues that emerged, and the problem-solving employed to mitigate these issues. METHODS The rate of unsatisfactory FNABs and core biopsies was determined for pathologists, BHC providers, and other clinicians and compared for two different periods. Adequacy criteria during both periods required correlation of the cytologic findings with the clinical and breast imaging findings, and did not require identification of a specific number of ductal epithelial cells. RESULTS During the first time period, 25% of breast FNABs performed in the BHC received an inadequate evaluation versus 6% performed by pathologists and 14% performed by other clinicians. The BHC adequacy rate exceeded the 20% upper threshold recommended by the National Cancer Institute (NCI), and did not decrease after additional FNAB training. During the first time period, 24% of core biopsies received an adequacy evaluation of unsatisfactory. During the second time interval, the core biopsy volume increased and 12% received an unsatisfactory adequacy evaluation. CONCLUSIONS It is appropriate to use noncellular features such as clinical and imaging findings as adequacy criteria for breast FNABs rather than identification of a minimal number of ductal epithelial cells. However, the 20% upper threshold for unsatisfactory breast FNABs recommended by the NCI was not appropriate for the BHC setting because the nature of the lesions seen in this type of practice can lead to an increase in inadequate specimens and cause unnecessary concern regarding quality. The authors recommended that laboratories receiving a large number of clinician-performed FNABs from a community population, especially a BHC, define their own unsatisfactory threshold above which they will investigate for technical or other problems. Cancer (Cancer Cytopathol) 2004. © 2004 American Cancer Society.
The challenge of safe lunar landing

The Apollo lunar landings were both incredibly successful and challenging. As the world watched, each of the six landing missions faced potentially mission ending hazards within each of the landing sites while simultaneously dealing with diminishing fuel reserves and a unique landing environment. Hazards in the form of rocks, craters and slopes all were perilously close to each of the successfully landed missions and brought to light the incredible challenge each mission faced.
Determination of air brake adjustment from air pressure data

AbstractContinuing research in brake condition monitoring for vehicles equipped with air brakes considers the feasibility of using air pressure data to determine brake stroke, a vital parameter in determining the effectiveness of the total braking system. Recent statistics show there is an alarming number of vehicles operating with brakes that are out of adjustment even with the introduction and requirement of automatic slack adjustment in 1994. The importance of brake stroke information is thus highlighted. To address this problem, a mathematical model of an air brake chamber is developed and used to investigate parameter sensitivity. A method capable of indirectly determining brake stroke by examining air pressure data is formulated and its effectiveness is proven through simulation and testing.
On the space‐time characteristics of wall‐pressure fluctuations

A database obtained by direct numerical simulation of turbulent channel flow was used to compute the three‐dimensional frequency/wave‐number spectrum of wall‐pressure fluctuations. The spectrum was used to deduce scaling laws for pressure fluctuations and to evaluate the similarity form for the power spectrum. The convection velocity as a function of frequency, wave number, and spatial and temporal separations was calculated and compared with the experimental data. The problem of artificial ‘‘acoustics’’ in numerical simulation of incompressible flows is discussed.
Detection and measurement of sulfur mustard offgassing from the weanling pig following exposure to saturated sulfur mustard vapor

Animal models are employed to investigate mechanisms of injury and to evaluate protective measures against sulfur mustard (HD) exposure. The ability to detect and quantify HD enables the researcher to follow safe procedures in handling skin samples. We designed an experimental procedure to measure HD offgassing from animal models. A Minicams--a portable gas chromatograph equipped with a flame photometric detector and on-line sorbent collection and desorption--was used to monitor the HD concentration. Confirming measurements were made using a two-step process that trapped HD on a Tenax sorbent off-line and then transferred the sample by means of an ACEM 900 to a gas chromatograph equipped with either a flame photometric detector or a mass spectrometer. Sulfur mustard offgassing data are presented from three experiments in which weanling pigs were exposed to saturated HD vapor via vapor caps containing 10 microl of HD. The HD concentration was measured in time-weighted-average (TWA) units at a specific HD application site. The current 8-h maximum exposure limit for HD is 3-ng l(-1), (1 TWA unit). The largest TWA value measured near a 3 h time point was a Minicams measurement of 0.48 TWA at 2 h and 53 min after removal of a vapor cap containing HD from a single exposure site on an animal that had 24 concurrent dorsal exposure sites. Gas chromatography/flame photometric detection and gas chromatography/mass spectrometry were used to confirm the Minicams data and to provide greater sensitivity and selectivity down to 0.1 TWA. The gas chromatography/mass spectrometry data confirmed that HD concentrations fell below 0.1 TWA in <5 h for a specific site. These measurements of HD concentrations provided information on the expeditious and safe handling of HD-exposed tissue.
Omar Khayyam: Poet, Rebel, Astronomer

Omar Khayyam: Poet, Rebel, Astronomer, Hazhir Teimourian, Stroud: Sutton, 2007, ISBN 978-0-7509-4715-2, xiv + 365pp. As a life-long admirer of Omar Khayyam, who spent many years unearthing evidence...
Structures of dNTP Intermediate States during DNA Polymerase Active Site Assembly

DNA polymerase and substrate conformational changes are essential for high-fidelity DNA synthesis. Structures of DNA polymerase (pol) β in complex with DNA show the enzyme in an "open" conformation. Subsequent to binding the nucleotide, the polymerase "closes" around the nascent base pair with two metals positioned for chemistry. However, structures of substrate/active site intermediates prior to closure are lacking. By destabilizing the closed complex, we determined unique ternary complex structures of pol β with correct and incorrect incoming nucleotides bound to the open conformation. These structures reveal that Watson-Crick hydrogen bonding is assessed upon initial complex formation. Importantly, nucleotide-bound states representing intermediate metal coordination states occur with active site assembly. The correct, but not incorrect, nucleotide maintains Watson-Crick hydrogen bonds during interconversion of these states. These structures indicate that the triphosphate of the incoming nucleotide undergoes rearrangement prior to closure, providing an opportunity to deter misinsertion and increase fidelity.
Morphometric study of the anteroventral cochlear nucleus of two mouse models of presbycusis

The dimensions and volume of the anterior ventral cochlear nucleus (AVCN), the density and number of AVCN neurons, and the size of neuronal somata nuclei (in Nissl-stained tissue) were determined in two mouse models of age-related hearing loss: the C57BL/6J strain, which undergoes progressive chronic sensorineural hearing loss with onset during young adulthood, and the CBA/J, which demonstrates only moderate hearing loss with onset late in life. Frontal and horizontal AVCN sections, as well as cochleas, were analyzed in 4 C57 age-groups (1, 7, 12, 19+ months) and in 3 CBA groups (1, 10, 22 months). Within each strain no significant changes in AVCN dimensions or volume occur with aging. In C57 mice, packing density and cell number decrease between 1 and 7 months, but remain stable thereafter, despite chronic severe hearing impairment. CBA mice show a reduction in AVCN cell number and packing density only during the second year of life. In aging C57 mice, the size of spherical and perhaps globular cells increases, whereas the size of multipolar cells tends to decrease slightly. In CBA mice, all three AVCN cell types tend to decrease in size with aging. The early cell loss and cell size increases in C57 mice are most consistent in the dorsal (high frequency) region of the AVCN. Likewise, loss of cochlear spiral ganglion cells is most pronounced in the base of the cochlea, which provides input to this region. The data indicate that aging is associated with rather different central effects, depending on AVCN cell type, cochleotopic organization, genotype, and/or the type of peripheral hearing loss involved. The C57 and CBA AVCNs also differ in several aspects irrespective of age. The volume of AVCN and number of AVCN neurons are significantly greater in C57 mice.
Analytical model for a one-dimensional slotted stand-off layer damping treatment

Passive stand-off layer and slotted stand-off layer damping treatments are presently being implemented in many commercial and defense designs. In a passive stand-off layer damping treatment, a stand-off or spacer layer is added to a conventional passive constrained layer damping treatment. Additionally, this stand-off layer can be slotted in order to reduce the bending rigidity and total mass of the damping treatment. A preliminary analytical model has being developed for a slotted stand-off layer damping treatment applied to a beam. This mathematical model is based on Euler-Bernoulli beam theory, and may be able to provide an analytical solution of the frequency response for a beam treated with slotted stand- off layer damping.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Further Studies on Total Synthesis of Sarain A. Efforts Toward Annulation of the Macrocyclic Rings

Studies have been conducted on testing strategies for annulation of the two macrocyclic rings onto the central tricyclic nucleus of sarain A (1). In particular, methodology has been developed for introduction into the core of C-3‘ and C-3 substituents, which are necessary for construction of the “eastern” and “western” macrocyclic rings of 1, respectively. Formation of the western ring has been successfully addressed via a ring-closing olefin metathesis strategy utilizing the Grubbs ruthenium catalyst. With this macrocyclization approach, a key intermediate lactam has been prepared which will be utilized in a total synthesis of the natural product.
Reduction of spinal loading through the use of handles

A study was performed to investigate how different types of handle coupling affect the loading on the spine. Ten male grocery item selectors performed a laboratory simulation of a warehouse palletizing task. Participants transferred the cases from a pallet in a storage bin to the destination pallet. The trunk motions and muscle activities were monitored by a Lumbar Motion Monitor (LMM) and electromyographic electrodes, respectively, and used as input to an EMG-assisted biomechanical model. The results of the study revealed that the presence of handles reduced the complex loads on the spine. This was particuarly true when lifting to the lowest positions of the pallet, where the highest forces occurred. It was determined that the maximum spinal compression forces were reduced by an average of 6.8% when handles were added to the cases. The presence of handles affected the moments imposed on the trunk in the lower regions on the pallet, indicating a difference in lifting style and/or more sagittal flexion. The results of this study suggest that the multiplier for handle coupling in the 1991 NIOSH Revised Lifting Equation was appropriate for higher lifts (at 133.8 cm), but needs to be more protective for 'poor' coupling conditions with lower vertical heights, which are the most common in industry. Based on these results, it is recommended that handles be designed into the cases that are commonly lifted from low levels in warehousing and other manual materials handling situations.
Wages, Incentive Schemes, and the Role of Gender

Goldin (1986) adds to this subject by introducing the role of gender into the choice of a compensation scheme. Goldin argues that women are more likely to be paid according to an incentive scheme because their behavior cannot be influenced as readily by the judicious use of time rates designed to elicit effort. By rearranging the profile of lifetime earnings so that workers accumulate unpaid rents during early years which are paid out during later years, effort levels may be improved without directly linking pay to performance (Lazear, 1979, 1981). Goldin claims such escalating time rates (ETR) are less likely to be successful with women who, historically, have been short-term workers and less inclined to be motivated by delayed rents. Thus, use of ETR may dictate the hiring of mostly men because of their long-term status while women will disproportionately be paid by piece rates or similar incentive schemes. In addition to predicting that women will be more likely to be paid by incentive schemes, Goldin's logic also predicts a resulting wage pattern. Women paid according to incentive schemes should enjoy a larger earnings advantage over women not receiving incentive pay than men on such schemes do over their counterparts not on incentive pay. This results because those on time rates consist of a combination of
Sophistry In and As Its Course

Although sophistry has been characterized as separable from real philosophy, formal analysis does not work without it and one cannot always identify just where philosophy leaves off and sophistry begins. Whether sophistry offers anything to thinking reason has to do with what parties in dialogue do with sophistries. Sophistries can close down or open up philosophical perspectives, depending on the local work that sophistic strategies accomplish. Such local work of philosophers is rarely available to analyses of docile texts, but they can be furthered by ethnomethodological studies of illustrative philosophical argumentation presented and analyzed in videotaped format.
Minimal SO(10) Unification

It is shown that the doublet-triplet splitting problem can be solved in SO(10) with only a single adjoint Higgs field (as seems to be required by superstring theory), while at the same time avoiding the existence of light fields that would destroy the unification of gauge couplings. {copyright} {ital 1997} {ital The American Physical Society}
The DAZ gene cluster on the human Y chromosome arose from an autosomal gene that was transposed, repeatedly amplified and pruned

It is widely believed that most or all Y–chromosomal genes were once shared with the X chromosome. The DAZ gene is a candidate for the human Y–chromosomal Azoospermia Factor (AZF). We report multiple copies of DAZ (>99% identical in DNA sequence) clustered in the AZF region and a functional DAZ homologue (DAZH) on human chromosome 3. The entire gene family appears to be expressed in germ cells. Sequence analysis indicates that the Y–chromosomal DAZ cluster arose during primate evolution by (i) transposing the autosomal gene to the Y, (ii) amplifying and pruning exons within the transposed gene and (iii) amplifying the modified gene. These results challenge prevailing views of sex chromosome evolution, suggesting that acquisition of autosomal fertility genes is an important process in Y chromosome evolution.
Comparison of calculated and measured dislocation density in LEC-grown GaAs crystals

Abstract Dislocation densities in melt-grown GaAs crystals, ranging from 3 × 10 3 to 7 × 10 4 cm -2 , are compared to values predicted by a micro-mechanical creep model based on the Alexander-Haasen formulation of slip in diamond crystals. The temperature and thermal strain histories of the crystals are obtained from the numerical simulation of the growth and cool-down processes. These histories are used in the creep model, and the associated time-variation of dislocation densities are calculated. The measured and calculated dislocation densities show a remarkably good agreement in the central region of the crystal. Towards the crystal periphery, however, the measured dislocation densities are appreciably larger than the predicted values. The possible reasons for this anomaly are discussed. The reported agreement between model and experimental results indicates that dislocation densities as low as 10 3 cm -2 are related to thermal-stress-induced slip in the matrix. The implications of this finding on various approaches for reduction of the dislocation density in melt-grown crystals to below currently attainable levels of high-10 2 to low-10 3 cm -2 are discussed.
Enzymatic Characterization of a Nonmotile, Nonsolventogenic Clostridium acetobutylicum ATCC 824 Mutant

Decreased motility has been correlated with lower solvent yields in fermentations withClostridium acetobutylicum. A spontaneous mutant ofC. acetobutylicum was found to be nonmotile as evidenced by bright-field microscopy and motility-agar plates. The loss of motility was accompanied by the production of an altered flagellin. The mutant flagellin was much smaller than the wild-type (32 vs 43 kDa), although the NH2-terminal amino acid sequences of both flagellins were identical. This mutant was simultaneously incapable of producing the solvents acetone and butanol. In vitro enzyme activity analyses demonstrated the absence of three enzymes directly involved in solvent production: acetoacetate decarboxylase (EC 4.1.1.4), acetoacetyl-coenzyme A:acetate/butyrate coenzyme A-transferase (EC 2.8.3.9), and NADP-dependent butyraldehyde dehydrogenase (EC 1.2.1.10).
Evaluating mechanical properties of thin layers using nanoindentation and finite-element modeling: Implanted metals and deposited layers

We present a methodology based on finite-element modeling of nanoindentation data to extract reliable and accurate mechanical properties from thin, hard films and surface-modified layers on softer substrates. The method deduces the yield stress, Young`s modulus, and hardness from indentations as deep as 50% of the layer thickness.
Breast mass removal made easy by the lump extractor: introducing a new instrument in breast surgery.

The difficulty encountered in the removal of breast lumps has been addressed by the use of a new instrument. The lump extractor described in this paper allows minimal scar surgery and prevents crushing of the breast mass.
Determination of the interfacial tension by thermal grooving and zero creep in coaxial wires—theory

Abstract A model based on the thermal grooving and zero creep theory is developed to allow absolute measurements of the interfacial energy between two materials in the shape of bamboo coaxial wires.
Two general properties of the saddle-point solutions of dynamic games

In deterministic team problems every closed-loop representation of an optimal open-loop solution is also optimal. This property, however, no longer holds true when the optimization problem is a zero-sum or a nonzero-sum game. In zero-sum games, two weaker (but still general enough) versions of this statement are valid, which still fail to hold in the case of nonzero-sum games. In this correspondence we state and prove these two general properties of the saddle-point solution in dynamic games.