cssi/SciSciGPT-SciSciNet huggingface dataset:
Ocean overturning since the Late Cretaceous: Inferences from a new benthic foraminiferal isotope compilation

[1] Benthic foraminiferal oxygen isotopic (d 18 O) and carbon isotopic (d 13 C) trends, constructed from compilations of data series from multiple ocean sites, provide one of the primary means of reconstructing changes in the ocean interior. These records are also widely used as a general climate indicator for comparison with local and more specific marine and terrestrial climate proxy records. We present new benthic foraminiferal d 18 O and d 13 C compilations for individual ocean basins that provide a robust estimate of benthic foraminiferal stable isotopic variations to � 80Ma andtentatively to � 110Ma. First-order variations ininterbasinal isotopicgradients delineate transitions from interior ocean heterogeneity during the Late Cretaceous (>� 65 Ma) to early Paleogene (35– 65 Ma) homogeneity and a return to heterogeneity in the late Paleogene–early Neogene (35–0 Ma). We propose that these transitions reflect alterations in a first-order characteristic of ocean circulation: the ability of winds to make water in the deep ocean circulate. We document the initiation of large interbasinal d 18 O gradients in the early Oligocene and link the variations in interbasinal d 18 O gradients from the middle Eocene to Oligocene with the increasing influence of wind-driven mixing due to the gradual tectonic opening of Southern Ocean passages and initiation and strengthening of the Antarctic Circumpolar Current. The role of wind-driven upwelling, possibly associated with a Tethyan Circumequatorial Current, in controlling Late Cretaceous interior ocean heterogeneity should be the subject of further research.
The Antihypercholesterolemic Activity of Candicidin as a Function of Dietary Cholesterol in Cockerels

In the first of two experiments using White Leghorn cockerels, a multifactorial analysis of variance was employed to characterize the antihypercholesterolemic responses (AHC) to candicidin (a heptaene macrolide antifungal antibiotic)-containing diets and the manner in which hypercholesterolemic challenges of different magnitudes modify these responses. In hypercholesterolemic diets, oral candicidin reduced plasma cholesterol concentration in a dose-dependent manner. The relative AHC effects of the diet were dependent on and varied directly with the presence and magnitude of the hypercholesterolemic challenge. The AHC effects of oral candicidin appeared to be additive to the homeostatic mechanisms limiting the rise in plasma cholesterol concentration induced by hypercholesterolemic diets. In the second experiment the absorption of oral 14C-candicidin was studied. Radioactivity above background levels was not found in any of the sampled tissues 4 days after administration of the 14C-candicidin pulse. The total cumulative recovery of radioactivity in the excreta was approximately 95% of the administered dose after 4 days. Within the limits of detection, oral candicidin did not appear to be absorbed from the intestine and appeared to be rapidly and quantitatively eliminated from the body in the feces. Chronic provision of candicidin appeared to increase transit time through the gastrointestinal tract.
Enzymatic assay for glutathione.

Abstract Methods for measuring total glutathione are described. These are based on the ability of glutathione and glutathione reductase (EC 1.6.4.2.) to catalyze the oxidation of NADPH by Ellman's reagent. Except for highest glutathione levels, NADP + rather than the reduced Ellman compound is measured. For intermediate sensitivity (2 × 10 −12 mol) NADP + is measured stoichiometrically by conversion to NADPH and determination of fluorescence. For smaller amounts (10 −14 mol) the NADP + generated is amplified by enzymatic cycling. These procedures have been tested extensively on kidney and are probably applicable to tissues in general.
The Impact of Developmental Mathematics Courses and Age, Gender, and Race and Ethnicity on Persistence and Academic Performance in Virginia Community Colleges

This research study examined the 2006 cohort of First-Time-in-College students from all 23 community colleges in Virginia. The goal was to examine fall-to-fall persistence and success in the first college-level mathematics course. Predictor variables used were developmental status, age, gender, and race and ethnicity of the student. Interaction variables were created to determine if age, race and ethnicity, or gender moderates the effects of developmental status for both persistence and success. And a model was created using all main and interaction predictor variables to determine to what extent each variable accounts for persistence and success. It was found that neither gender nor race and ethnicity moderates developmental status for either persistence or success, but age moderates both success and persistence. Developmental courses are more effective for traditionally aged students and developmental courses are positively related to the persistence of nontraditionally aged students and negatively rela...
An Approach to Include the Effects of Diffuse Functions in Potential Energy Surface Calculations

A new approach is proposed and investigated for approximately including the effects of diffuse functions in one-particle basis sets when high accuracy is desired. The method is cost-effective for use in computing quartic force fields (QFFs), global potential energy surfaces (PESs), or other situations when a large part of the PES is needed. It is conservatively estimated that the use of this approximation leads to a computational savings of a factor of five, and it is argued that this could be significantly larger if input/output wait times are considered. It can be used when extrapolation to the one-particle basis set limit is performed, or it can be used simply to approximate the effect of diffuse functions for a larger basis set. The new approach is based on scaling the diffuse function effect for a smaller basis set to approximate the effect for a larger basis or an extrapolated energy in which larger basis set(s) are used. The scale factor is written as a function of the geometrical coordinates of the molecule and thus it includes a geometry dependence. We report results where the scale factor is a constant, includes through gradient terms, includes through second derivative terms, and includes through diagonal second and third derivative terms. The method has been tested in the calculation of accurate QFFs, equilibrium structures, and harmonic and fundamental vibrational frequencies for NH(2)(-), OH(-), H(2)O, and CH(3)OH. It is found that including up through diagonal second derivative terms leads to reliable fundamental vibrational frequencies and is cost-effective. It is also concluded that the use of a 5Z-quality basis set is essential if high accuracy is desired for these properties, even with extrapolation to the one-particle basis set limit.
Piezoreflectivity of the Noble Metals

The piezoreflectance spectra of evaporated films of copper, silver, and gold have been measured in the range 1.5-5.0 eV. The experimental results were subjected to a Kramers-Kronig analysis in order to determine the corresponding phase changes $\ensuremath{\Delta}\ensuremath{\theta}$. In this manner a complete specification of the optical properties of the strained material is made. The conditions which must be fulfilled if this Kramers-Kronig inversion is to be made are discussed. The strain-induced changes in the real and imaginary parts of the dielectric constant tensor are found to be quite similar for all three materials. The over-all structure shows qualitative agreement with the deformation-potential model, and the signs of the deformation potentials of some of the transitions are tentatively assigned. The results for all three metals show additional structure in a region lower in energy than that for which structure has been previously detected. The most reasonable explanation for this is that there are interband transitions possible at lower energy than has previously been presumed. The similarity of this structure in $\ensuremath{\Delta}{\ensuremath{\epsilon}}_{2}$ for all three metals indicates that the same transitions are involved for copper, silver, and gold.
Assay of organic liquid contents in predominantly water-wet unconsolidated porous media

Abstract Immiscible organic liquids may be extracted from moist soil or other hydrophilic porous media by shaking a suspension of water and soil in a glass jar with a piece of porous polyethylene. The water displaces the organic liquid from the predominantly hydrophilic sample and the hydrophobic polyethylene preferentially absorbs the organic liquid, excluding water unless there is a detergent associated with the organic. Because most soils have some hydrophobic surfaces, the extraction of organic liquids by displacement with water is not quite complete. A correction is therefore made in the assay method by including samples with known organic liquid content as controls. The amount of organic liquid not displaced from the control samples can also be used to indicate the extent of hydrophobic sites in predominantly water-wet porous media. Organic liquid extractions were made by using three soils and two organic liquids. The standard deviation among replicated extractions was 0.010 g organic liquid. By applying a correction to the mass of organic liquid recovered, the assay accuracy was ±0.001 g organic liquid/g soil with 20.0-g oven-dry soil samples. It is likely that this assay method could be scaled up and used as a remediation method for removing and recovering organic liquids from earth excavated from spill or leak sites.
Subcutaneous mastectomy and immediate reconstruction for prevention of breast cancer for high-risk patients

Breast cancer is the most common malignant tumor among females in the USA, with one out of eight American females developing breast cancer in their lifetimes. The latest studies [1] show that 212,920 new cases of invasive cancer developed in 2006, which is 2.5 times more common than the incidence of lung cancer, and that 40,970 females will die from this disease each year. Therefore, awareness of this cancer is an important health issue, with more women beginning to assess their risk of breast cancer, either informally or with instruments such as the GAIL model [2]. The availability of genetic testing for BRCA-1 and BRCA-2 has revealed many women who are at significantly increased risk. Many aggressive surveillance programs have been developed using advanced MRI and ultrasound, and reductions in breast cancer risk of 50% or more have been proven using chemoprevention strategies with tamoxifen and raloxifene. However, many women are starting to seriously consider prophylactic mastectomy for near-total reduction of breast cancer risk. At our institution, we have developed a procedure for prophylactic subcutaneous mastectomy via an inframammary incision that spares the nipple and is combined with immediate silicone implant reconstruction with the assistance of Alloderm®. In this article we will describe the procedure and some of the important issues surrounding its implementation from our experience.
Regulatory mechanisms underlying the differential growth of dendrites and axons

A typical neuron is comprised of an information input compartment, or the dendrites, and an output compartment, known as the axon. These two compartments are the structural basis for functional neural circuits. However, little is known about how dendritic and axonal growth are differentially regulated. Recent studies have uncovered two distinct types of regulatory mechanisms that differentiate dendritic and axonal growth: dedicated mechanisms and bimodal mechanisms. Dedicated mechanisms regulate either dendritespecific or axon-specific growth; in contrast, bimodal mechanisms direct dendritic and axonal development in opposite manners. Here, we review the dedicated and bimodal regulators identified by recent Drosophila and mammalian studies. The knowledge of these underlying molecular mechanisms not only expands our understanding about how neural circuits are wired, but also provides insights that will aid in the rational design of therapies for neurological diseases.
The Sr and Rb contents of the granite G-1 and the diabase W-1☆

Abstract The interlaboratory calibration granite and diabase standards G-1 and W-1 have been analysed for Rb and Sr mass spectrometrically by the stable isotope dilution method. G-1 was found to contain 216 p.p.m. Rb and 233 p.p.m. Sr, and W-1 to contain 28.5 p.p.m. Rb and 177 p.p.m. Sr. These results are compared to other published analyses for these elements. If these new analyses are accurate, several published works, in which G-1 and W-1 were used as standards for Rb and Sr, are in need of revision
Diagnostic least squares

Abstract In the determination of a set of parameters from a set of observations by the method of least squares, it often occurs that the relationships provided by the observations are not really linearly independent when the random errors in the observations are considered. A method for finding physically reasonable parameters and confidence limits for parameters is described. This method is based on parameter scaling and diagonalization of the matrix of the normal equations.
HIPAA and information security risk: implementing an enterprise-wide risk management strategy

The Health Insurance Portability and Accountability Act (HIPAA) of 1996 effectively establishes a standard of due care forhealthcare information security. One of the challenges of implementing policies, procedures, and practices consistent withHIPAA requirements in the Department of Defense Military Health System (MHS) is the need for a method that can tailorthe requirements to a variety of organizational contexts. This paper will describe a self-directed information security riskevaluation that will enable military healthcare providers to assess their risks and to develop mitigation strategies consistentwith HIPAA guidelines. The self-directed risk assessment can be tailored for the ranges of operating environments found inthe MHS. It will focus on both organizational and technological improvements using the HIPAA regulations as a benchmarkfor information security readiness. The evaluation will utilize a interdisciplinary team in an organization to oversee theprocess and apply recommendations generated by the team. In addition, staff from multiple organizational levels in theorganization will contribute their unique knowledge of the enterprise's operations. This information combined withtechnology-based vulnerabilities yields the organization's risks. This paper will also describe the results of early field tests ofthe evaluation and provide a summary of lessons learned.Keywords: HIPAA, information security risk, information security readiness, OCTAVE, practice, asset, threat, vulnerability
Metal ion and ligand binding of integrin α5β1

Integrin α5β1 binds to an Arg–Gly–Asp (RGD) motif in its ligand fibronectin. We report high-resolution crystal structures of a four-domain α5β1 headpiece fragment, alone or with RGD peptides soaked into crystals, and RGD peptide affinity measurements. The headpiece crystallizes in a closed conformation essentially identical to that seen previously for α5β1 complexed with a Fab that allosterically inhibits ligand binding by stabilizing the closed conformation. Soaking experiments show that binding of cyclic RGD peptide with 20-fold higher affinity than a linear RGD peptide induces conformational change in the β1-subunit βI domain to a state that is intermediate between closed (low affinity) and open (high affinity). In contrast, binding of a linear RGD peptide induces no shape shifting. However, linear peptide binding induces shape shifting when Ca2+ is depleted during soaking. Ca2+ bound to the adjacent to metal ion-dependent adhesion site (ADMIDAS), at the locus of shape shifting, moves and decreases in occupancy, correlating with an increase in affinity for RGD measured when Ca2+ is depleted. The results directly demonstrate that Ca2+ binding to the ADMIDAS stabilizes integrins in the low-affinity, closed conformation. Comparisons in affinity between four-domain and six-domain headpiece constructs suggest that flexible integrin leg domains contribute to conformational equilibria. High-resolution views of the hybrid domain interface with the plexin–semaphorin–integrin (PSI) domain in different orientations show a ball-and-socket joint with a hybrid domain Arg side chain that rocks in a PSI domain socket lined with carbonyl oxygens.
Performance of the Expressnet with voice/data traffic

In the past few years, local area networks have come into widespread use for the interconnection of computers. Together with the trend towards digital transmission in voice telephony, this has spurred interest in integrated voice/data networks. The Expressnet, an implicit-token round-robin scheme using unidirectional busses, achieves high performance even at bandwidths of 100 Mb/s. Other features that make the protocol attractive for voice/data traffic are bounded delays and priorities. The latter is achieved by devoting alternate rounds to one or the other of the two traffic types. By the use of accurate simulation, the performance of the Expressnet with voice/data traffic is characterized. It is shown that the Expressnet satisfies the real-time constraints of voice traffic adequately even at bandwidths of 100 Mb/s. Data traffic is able to effectively utilize bandwidth unused by voice traffic. The trade-offs in the alternating round priority mechanism are quantified. Loss of voice samples under overload is shown to occur regularly in small, frequent clips, subjectively preferable to irregular clips. In a comparison of the Expressnet, the contention-based Ethernet and the round-robin Token Bus protocols, the two round-robin protocols are found to perform better than the Ethernet under heavy load owing to the more deterministic mode of operation. The comparison of the two round-robin protocols highlights the importance of minimizing scheduling overhead at high bandwidths.
Photoassisted Access to Enantiopure Conformationally Locked Ribofuranosylamines Spiro-Linked to Oxazolidino-Diketopiperazines.

N-Furoylated l-threonine-, serine-, or cysteine-based aminoacetals are coupled with o-aminoketones or aldehydes to offer rapid access to diverse enantiopure polyheterocycles possessing conformationally locked aminoglycoside-containing molecular scaffolds. The key step involves photogeneration of azaxylylenes which undergo [4 + 4] or [4 + 2] cycloadditions to the tethered furoyl pendants.
On K s -free subgraphs in K s + k -free graphs and vertex Folkman numbers

Extending the problem of determining Ramsey numbers Erdős and Rogers introduced the following function. For given integers 2 ≤ s 0 and sufficiently large integers 1 ≪ k ≪ s, Ω(n 1/2−ɛ ) ≤ f s,s+k (n) ≤ O(n 1/2+ɛ . In addition, we also discuss some connections between the function f s,t and vertex Folkman numbers.
Changing Patterns of Violence and Justice In Fourteenth- and Fifteenth-Century Florence

The Otto di Guardia was a powerful magistracy established in the late fourteenth century just after Florence's experiment with democratized government (1378). The new regime was much perturbed by fear of revolution and replication of the terrible events of the Ciompi uprising. Intelligent commentators such as Francesco Guicciardini were to argue a century and a half later that formation of the Otto had saved the Repub- lic from anarchy. Without the fear of this dread tribunal, seditious and factious Florentines would certainly have toppled the regime. Many modern interpreters of these events follow this grand generalization, but few have bothered to study the day-to-day activities of this court or in fact of any of its adjuncts.
Feedback controlling oxygen production in a cross-reaction between two photosystems in photosynthesis.

Abstract The non-linear light-saturation curve for oxygen production in both Chlorella vulgaris and Phormidium luridium at low light intensities, under anaerobic conditions is shown to be caused by the reduction of a pool of electron carriers coupled to both an endogenous reducing agent R, and to oxygen. The light dependence of oxygen production in these algae was studied by a repetitive-flash method, which allows a direct analysis of the steady-state kinetics of pool reduction. We propose a kinetic model which quantitatively accounts for these kinetics and several transient phenomena. This model centers on a novel cross reaction at the pool of photo and dark electron input and output, allowing a delicate poising of oxygen production by the environment. This model shows a positive feedback of oxygen on oxygen production.
Protecting the navajo people through tribal regulation of research

This essay explores the process and issues related to community collaborative research that involves Native Americans generally, and specifically examines the Navajo Nation’s efforts to regulate research within its jurisdiction. Researchers need to account for both the experience of Native Americans and their own preconceptions about Native Americans when conducting research about Native Americans. The Navajo Nation institutionalized an approach to protecting members of the nation when it took over Institutional Review Board (IRB) responsibilities from the US Indian Health Service (IHS) in 1996. While written regulations for the Navajo Nation IRB are not dissimilar, and in some ways are less detailed than those of the IHS IRB, in practice the Navajo Nation allows less flexibility. Primary examples of this include not allowing expedited review and requiring prepublication review of all manuscripts. Because of its broad mandate, the Navajo Nation IRB may also require review of some projects that would not normally be subject to IRB approval, including investigative journalism and secondary research about Navajo People that does not involve direct data collection from human subjects.
Collateralization of reticulospinal axons from the nucleus reticularis gigantocellularis to the cerebellum and diencephalon. A double-labelling study in the rat

Abstract Use of True blue and Nuclear yellow in double labelling experiments reveals that, in the rat, neurons of the nucleus reticularis gigantocellularis which innervate the spinal cord, cerebellum and diencephalon, are present in at least partially overlapping areas. However, relatively few reticulospinal neurons provide collaterals to either the cerebellum or diencephalon.
Lyme disease and optic neuritis: long-term follow-up of seropositive patients

In 1991 my colleagues and I at the Marshfield Clinic performed a prospective evaluation of the frequency of seropositivity of Borrelia burgdorferi , the infectious agent that causes Lyme disease, in patients with acute and isolated optic neuritis.1 Marshfield Clinic provides medical care for patients residing in an area endemic for Lyme disease.2 Four of 20 (20%) patients were seropositive with both an indirect fluorescent assay and ELISA (table). The three of four patients with follow-up ELISA testing had higher levels of Borrelia -specific immunoglobulin M. Of three patients who underwent evaluation of CSF, two had lymphocytic pleocytosis and two had elevated Borrelia antibody index. We recommended that patients with newly diagnosed optic neuritis who live in endemic regions should be tested for Lyme disease. We further recommended antibiotic treatment for those seropositive patients with unexplained CSF pleocytosis, elevated CSF Lyme antibody index, or rising serum levels of Borrelia -specific antibodies.1 View this table: Table Serologic results from the original cohort of four patients with …
A Generalized Sum-Rate Optimizer for Cooperative Multiuser Massive MIMO Link Topologies

Large-scale, or massive, multiple-input multiple-output (MIMO) systems are typified by the number of antennas contributing to a communication link. This type of link can consist of single nodes with a large number of antennas or a large number of cooperating nodes-each contributing a small number of antennas. Such massive systems naturally lead to link topologies that are not often considered in studies of smaller scale cooperative MIMO scenarios. For this system to be economically practical, each node participating in the massive link likely has limited transmit power capability, and therefore properly limiting the per-node transmit power must be incorporated into the signal processing algorithm. This paper develops a generalized multiuser massive MIMO (G4M) optimization algorithm for colocated or cooperative signaling, subject to any sum-, per-antenna, or per-node power constraint, and that can also accommodate nonlinear precoding and detection and any number of antennas. Using the G4M algorithm, a number of topologies unique to cooperative massive MIMO are described, demonstrating the facility this algorithm provides in optimizing the performance of multiuser massive links with atypical topologies.
Spectral Data Reduction via Wavelet Decomposition

The greatest advantage gained from hyperspectral imagery is that narrow spectral features can be used to give more information about materials than was previously possible with broad-band multispectral imagery. For many applications, the new larger data volumes from such hyperspectral sensors, however, present a challenge for traditional processing techniques. For example, the actual identification of each ground surface pixel by its corresponding reflecting spectral signature is still one of the most difficult challenges in the exploitation of this advanced technology, because of the immense volume of data collected. Therefore, conventional classification methods require a preprocessing step of dimension reduction to conquer the so-called "curse of dimensionality." Spectral data reduction using wavelet decomposition could be useful, as it does not only reduce the data volume, but also preserves the distinctions between spectral signatures. This characteristic is related to the intrinsic property of wavelet transforms that preserves high- and low-frequency features during the signal decomposition, therefore preserving peaks and valleys found in typical spectra. When comparing to the most widespread dimension reduction technique, the Principal Component Analysis (PCA), and looking at the same level of compression rate, we show that Wavelet Reduction yields better classification accuracy, for hyperspectral data processed with a conventional supervised classification such as a maximum likelihood method.
Auditory Analysis Of Temporally Distorted Sentential Approximations

Previous investigators have emphasized the significant role of time in auditory perceptual processing. Two factors important in this process are word duration and interstimulus interval. This study was designed to investigate the perceptual consequences of independent modification of these two factors, using two orders of sentential approximations. The results show that while both temporal factors operate in perceptual accuracy, word duration plays a more significant role than interstimulus interval. Also, perceptual errors may be offset by increasing the order of sentential approximations. The results are discussed in view of their implications for audiological assessment.
Synthesis of bismuth and antimony complexes of the “larger” calix[n]arenes (n = 6–8); from mononuclear to tetranuclear complexes

A series of calix[n]arene (n = 6–8) bismuth and antimony complexes were synthesized and fully characterized by NMR, X-ray, IR, UV-Vis and elemental analysis. The monobismuth calix[6]arene complex [Bi{tBuC6(H)3}]21 was prepared by the reaction of para-tert-butylcalix[6]arene (tBuC6(H)6) with one equivalent of Bi[N(SiMe3)2]3. Complex 1 featured a Bi2(μ-O)2 central core similar to other bismuth calixarene complexes prepared by our group. Reaction of calix[6]arene (HC6(H)6) with two equivalents of Bi(OtBu)3 yielded different outcomes depending on the reaction solvent. If THF was used, complex [Bi{HC6(H)3}] 2 was obtained in 72% yield; however, when toluene was used, complexes 2 and [Bi2{HC6}] 3 were isolated in 23 and 57% yields, respectively. Mononuclear complexes 1 and 2 displayed dimeric structures in the solid state with cone-like conformations for the calixarene ligands. The 1H NMR spectrum of complex 2 displays patterns for an asymmetric structure with two signals in a 2 : 1 ratio for the unreacted OH groups. Treatment of calix[6]arenes RC6(H)6 (R = H, tBu) with two equivalents of SbR3 (R = OtBu, NMe2) produced dinuclear complexes [Sb2{HC6}] 4, and [Sb2{tBuC6}] 5, respectively. The 1H NMR spectra for the dinuclear complexes 3, 4, and 5 showed the characteristic calixarene pattern for a 1,2,3-alternate conformer. In the process of recrystallization of complex 4 an unexpected trimetallic complex with composition [Sb3O2{HC6(H)}] 4a was obtained in low yield. Treatment of para-tert-butylcalix[7]arene (tBuC7(H)7) with two equivalents of Bi(OtBu)3 produced the bimetallic complex [Bi2O{tBuC7(H)3}]26. Complex 6 contains an overall Bi4O2(OAr)8 core system with a structural resemblance to other bimetallic bismuth calixarene complexes reported by our group. The larger para-benzylcalix[8]arene (BnC8(H)8) and calix[8]arene (HC8(H)8) reacted with excess Bi(OtBu)3 to produce the tetranuclear complexes [Bi4O2{HC8}] 7 and [Bi4O2{BnC8}] 8, respectively. The solid state structure of complex 8 featured a dimeric unit with the calixarene ligands in pinched-cone conformation and displaying an overall Bi8O4(OAr)16·H2O core. No metal π-arene interactions were observed.
Middle-Class African American Pilots The Continuing Significance of Racism

This article examines the experiences of African Americans employed in the historically white airline industry. We conducted in-depth interviews with African American pilots currently employed in our nation’s commercial aviation industry. In recent decades, a strong argument has been made that race has been declining in significance as African American professionals make great strides in levels of education and positions of power. As our research suggests, this perspective does not take into account the often racialized experiences or the marginalization African Americans face once they have entered various industries. Ultimately, our research suggests that an extensive theory of systemic racism remains necessary in order to understand the mechanisms by which middle-class African Americans maneuver and cope with racism in predominately white work spaces.
Termination of DNA synthesis in vitro at apurinic sites but not at ethyl adducts on the template

The effects of DNA lesions produced by the carcinogenic alkylating agents ethylnitrosourea and diethylsulfate on the extent of DNA synthesis have been studied in a system utilizing circular single-stranded φX174 DNA as template and a 392-base restriction fragment as primer with E. coli polymerase I (Klenow fragment). Apurinic sites produced by loss of unstable ethylated bases from the template terminate DNA synthesis at the first such site encountered, but ethyl adducts at most, if not all, locations permit readthrough.
Interactive effects of pentachlorophenol and hypoxia in the abalone (Haliotis rufescens) as measured by in vivo 31P NMR spectroscopy

Abstract The effects of hypoxia and pentachlorophenol (PCP) were investigated in red abalones (Haliotis rufescens) using flow-through exposure and in vivo 31P nuclear magnetic resonance spectroscopy (NMR). Following acclimation to clean seawater, three abalones were separately exposed to a 6-h sublethal concentration of PCP (1.2 mg 1−1) until the spectral resonance for inorganic monophosphate (Pi) was half-height to that of phosphoarginine (PA); the endpoint assured that all individuals were metabolically equivalent at the start of air exposure. They were exposed to clean seawater for 2 h to allow the effects from PCP to stabilize, then air for 45 min, and finally clean seawater for 15 h to check recovery. The effects of PCP in foot muscle included a decrease in the concentrations of PA and adenosine triphosphate ([PA] and [ATP], respectively), an increase in Pi, and a decrease in intracellular pH (pHi). Upon air exposure, [PA] and pHi rapidly declined further, [Pi] increased, and [ATP] did not change; the magnitudes were similar to those from emergence alone. After resubmergence, both [PA] and [Pi] recovered rapidly from the effects of hypoxia, but slowly from those of PCP. While pHi initially declined further, both [ATP] and pHi recovered to near-initial levels after 15 h. In general, the metabolic effects of hypoxia did not change upon pretreatment with PCP; the biochemical interaction of the two factors was additive. Another three abalones were separately exposed to PCP at an environmentally relevant concentration of 120 μg 1−1 for 6 h, air for 1 h, then the same PCP concentration for 2.5 h to check recovery. At the lower concentration, PCP produced no discernable effects, and those of hypoxia were similar to those without PCP. Since PCP produced no additional effects with or without hypoxia, it does not significantly impact red abalones at currently measured environmental concentrations. Use of in vivo NMR allows measurement of the interactive effects of multiple stress factors in live aquatic organisms, allowing assessment of the actual environmental effects of pollutants in the laboratory.
Effects of Frequent Classroom Testing.

ABSTRACT The educational effects of frequent classroom testing have been studied and discussed since the early part of this century. Testing advocates have suggested that more frequent classroom testing stimulates practice and review, gives students more opportunities for feedback on their work, and has a positive influence on student study time. Reviewers of relevant research and evaluation literature, however, have expressed uncertainty about whether such benefits are actually realized in classrooms. The present review distinguishes research on frequent classroom testing from research in two related areas, research on adjunct questions and research on mastery testing, and provides results from a meta-analysis of findings on frequency of classroom testing. The meta-analysis showed that students who took at least one test during a 15-week term scored about one half of a standard deviation higher on criterion examinations than did students who took no tests. Better criterion performance was associated with...
Stone granuloma causes ureteropelvic junction obstruction after percutaneous nephrolithotomy and antegrade endopyelotomy.

Stone granuloma is a rare cause of ureteral obstruction. To our knowledge only 1 case of secondary ureteropelvic junction obstruction following percutaneous nephrolithotomy and ultrasonic lithotripsy has been reported in the literature. It has been postulated that perforation with migration of stone fragments into the ureteral wall may be a mechanism for this occurrence. We report a case of recurrent ureteropelvic junction obstruction due to stone granuloma after simultaneous percutaneous nephrolithotomy and antegrade cold knife endopyelotomy.
An Empirical Test of Trust-Building Processes and Outcomes in Sales Manager-Salesperson Relationships

This study examines three trust-building processes and outcomes in sales manager-salesperson relationships. This study, based on a sample of more than 400 business-to-business salespeoples from a variety of industries, shows two trust-building processes (predictive and identification) to be significantly related to salesperson trust in the sales manager. Interpersonal trust was found to be most strongly related to shared values and respect. Trust was directly related to job satisfaction and relationalism, and indirectly related to organizational commitment and turnover intention.
Maturation of cerebral oxidative metabolism in the cat: a cytochrome oxidase histochemistry study.

The maturation of brain oxidative capacity was studied in kittens, using cytochrome oxidase histochemistry, at different ages throughout development. Optical densitometry values of reacted tissue were obtained for 50 different structures of the brain. In general, most structures reached adult levels of oxidative capacity by 30 days of age with some motor areas (e.g., cerebellum, red nucleus) exhibiting adult values as early as 7 days of age. Thereafter, some structures (e.g., basal ganglia, thalamus) exhibited levels of cytochrome oxidase activity that exceeded adult values for varying periods of time. These findings indicate regional heterogeneity in the maturation of cerebral oxidative capacity. Furthermore, these maturational patterns appear to correlate well with previous observations from anatomical, physiological and neuro-behavioral studies.
Prolonged diving and recovery in the freshwater turtle, Pseudemys scripta—II magnitude of depression of O2 requirements and the relation to body O2 stores

Abstract 1. 1. The magnitude of post-diving repayment of apparent O 2 deficit that occurred during a 6-hr diving period was determined in the freshwater turtle ( Pseudemys scripta elegans ) and analyzed in terms of body O 2 stores and O 2 utilization. 2. 2. Oxygen stores were exhausted in 1 hr, indicating that there was a 39% reduction in O 2 reduction in O 2 utilization during the first hour of diving. 3. 3. Post-diving repayment of total apparent O 2 deficit averaged 33.8± 31% and repayment of metabolic apparent O 2 deficit averaged 22%. 4. 4. These results support the hypothesis that energy requirements are depressed during prolonged diving and that reduction of energy requirements is a major mechanism for survival during this process.
Designing transonic wind-tunnel test sections for flow diagnostics and laser velocimeter applications

The design, fabrication, and validation of the Basic Aerodynamic Facility (BARF), developed for the direct comparison of three-dimensional laser velocimetry (LV) and hot-wire techniques at transonic speeds, are discussed. To accommodate the installation of the three-dimensional orthogonal LV system in the BARF, the transonic slots were redesigned to house windows, and the test section mounting was redesigned to facilitate LV transversing. Two-dimensional and three-dimensional code validation tests of the LV test section showed uniform mean flow through the test section to sonic speeds, and fluctuating pressure measurements at subsonic speeds which are consistent with facilities with good flow quality.
Anorexia nervosa—clinical features and long term follow-up

Abstract The clinical features of 60 patients hospitalized with the diagnosis of anorexia nervosa were reviewed. Weight loss, amenorrhea, psychological disturbances, and mild hypotension were frequent clinical manifestations. Laboratory data revealed that a low protein bound iodine and basal metabolism rate were frequently found, however, the patients were euthyroid. Serum proteins and other chemical studies were within the normal limits in the majority of patients. The most consistent endocrinologic abnormality was that of absent or low urinary gonadotropins. The disorder can be a mild one with complete recovery or can persist for many years occasionally terminating in death. Mis-diagnosis of the syndrome is not uncommon and must be differentiated from other diseases which result in malnutrition and emaciation. Follow-up information was reviewed in 53 out of the 60 patients. Sixty-eight per cent of these patients were categorized as either in “satisfactory” or “partially satisfactory” condition. Nine patients have died and the other 11 patients are incapacitated by their illness. The prognosis can often be determined by a careful assessment of the clinical features. Short duration of symptoms, a relatively small weight loss, high educational achievement, age of onset below 30 yr, and mild associated symptoms were correlated with improved prognosis. The type of treatment during hospitalization did not seem to alter the course of the disease.
The limitations of crisis theory as an explanatory mechanism in social gerontology.

This study examines five specific assumptions of crisis theory as this orientation relates to the prediction of life satisfaction following retirement. Pre-retirement and post-retirement interviews were conducted with a group of 114 men (mean age 68.2 years) residing in an urban area of central Missouri. The data reveal a significant decline in life satisfaction as predicted. Contrary to the theory, however, no significant changes in role behavior in three related areas-family, voluntary associations, and community-were found subsequent to retirement. In addition, the role changes accompanying retirement were not significantly associated with negative changes in satisfaction. Also, increases in role performance were not significantly related to positive changes in satisfaction. Finally, the correlation between work commitment and change in satisfaction proved negative and non significant. On the other hand, the correlation between work commitment and the desire for subsequent employment was negative and s...
EFFECT OF ASPIRIN ON CIRCULATORY RESPONSES TO CATECHOLAMINES.

Calf and foot blood flow responses to intravenous epinephrine and norepinephrine were studied by venous occlusion plethysmography. Subjects were studied on two control days and after having ingested 3.6 gms. aspirin daily for two days. Epinephrine-induced vasoconstriction in the foot and vasodilation in the calf were significantly reduced after aspirin as was norepinephrine-induced vasoconstriction in both the foot and the calf. Skin temperatures confirmed the reduction of cutaneous vasoconstrictor responses by aspirin. Pulse and blood pressure responses were unaffected. Le responsas del fluxo de sanguine in sura e pede al administration intravenose de epinephrina e norepinephrina esseva studiate per plethysmographia a occlusion venose. Le subjectos esseva studiate in duo dies de controlo e post haber ingerite aspirina durante duo dies in un dosage de 3,6 g per die. Le vasoconstriction inducite in le pede per epinephrina e le vasodilatation inducite in le sura per ille mesme pharmaco esseva reducite de maniera significative post le uso de aspirina, e le mesmo valeva pro le vasoconstriction inducite per norepinephrina tanto in le pede como etiam in le sura. Le temperaturas cutanee confirmava le effecto reductori de aspirina super le cutanee responsas vasocontrictori. Le responsas del pulso e del tension sanguinee non esseva afficite.
Effects of changes in tonicity of the extracellular solution on the size of vesicles in frog motor nerve terminals.

Frog nerve-muscle preparations were soaked and then fixed in solutions roughly isotonic to frog plasma, or in solutions that were markedly hypertonic or hypotonic. The hypertonic solution decreased the cross-sectional area of the muscle fibres but not of the synaptic vesicles. The hypotonic solution increased the cross-sectional area of the muscle fibres but did not produce comparable increases in the areas of the synaptic vesicles. Apparently the vesiclesin situ do not behave as simple osmometers. This fact is significant for theories of exocytosis and for the mechanism of transmitter packaging in the vesicles.
Relationship Quality, Commitment, and Stability in Long-Distance Relationships

Using a nationally representative sample (N = 870), the present study compared long-distance romantic relationships to close-proximity romantic relationships in terms of relationship quality, commitment, and stability. Individuals in long-distance relationships generally reported higher levels of relationship quality on a number of relationship quality variables, as well as higher levels of dedication to their relationships and lower levels of feeling trapped (i.e., felt constraint), but were similar to individuals in close-proximity relationships in terms of perceived and material constraints. Although individuals in long-distance relationships perceived a lower likelihood of breaking up with their partner at the initial time point, they were as likely as the individuals in close-proximity relationships to have broken up by the follow-up assessment.
Toward the Solution Structure of Human Insulin: Sequential 2D 1H NMR Assignment of a Des-pentapeptide Analogue and Comparison with Crystal Structure

2D {sup 1}H NMR studies are presented of des-pentapeptide-insulin, an analogue of human insulin lacking the C-terminal five residues of the B chain. Removal of these residues, which are not required for function, is shown to reduce conformational broadening previously described in the spectrum of intact insulin. This difference presumably reflects more rapid internal motions in the fragment, which lead to more complete averaging of chemical shifts on the NMR time scale. Sequential {sup 1}H NMR assignment and preliminary structural analysis demonstrate retention in solution of the three {alpha}-helices observed in the crystal state and the relative orientation of the receptor-binding surfaces. These studies provide a foundation for determining the solution structure of insulin.
Nash bargaining with the option to wait

Abstract This paper derives the Generalized Nash Bargaining Solution for two-player games where each player has the option of postponing bargaining till a future period. This option endogenously determines the threat points of the initial game. The outcome is compared with the case where there is no such option, and with the usual Rubinstein bargaining game where one offer per period is made. © 1997 Elsevier Science S.A.
Acute pulmonary embolism. II. Clinical.

Abstract Pulmonary embolism is the commonest lethal pulmonary disease in the United States and is a contributing cause to the deaths of many additional patients. Yet its clinical recognition remains difficult and often impossible. This is so because the lung has no pain fibers, and has a large vascular reserve, and because clinical manifestations, when present, are variable, complex, and not infrequently completely obscured by the underlying disorder. It is unlikely that additional clinical observations will significantly increase accuracy of diagnosis. Increased accuracy of diagnosis will depend upon the development of new screening tests and the fullest use of those presently available. These latter are the triad of increased serum lactic dehydrogenase and bilirubin with a normal serum glutamic oxalacetic transaminase, frequently repeated electrocardiograms and roentgenograms of the chest, lung scanning, and (hopefully) ultrasound. There would appear to be no reason to use screening tests in the vast majority of instances of pulmonary embolism which are clinically silent and free of clinical precursors, and yet these emboli may be forerunners of an additional pulmonary embolism for which treatment is still not satisfactory. Hence the best hope for reducing the morbidity and mortality from pulmonary emboli lies not in treatment but in prevention.
Squamous cell carcinoma of scrotum

Squamous cell carcinoma of the scrotum is a rare malignancy in the United States. This series includes the eighth reported case of this lesion in a black American. Surgery still remains the only effective therapeutic modality. The use of sentinel and superficial inguinal node biopsies was important in determining whether or not radical ilioinguinal lymphadenectomy was needed in 2 patients.