cssi/SciSciGPT-SciSciNet huggingface dataset:
Unraveling the Ties that Bind: Affective Expression and Perceived Conflict in Parent adolescent Interactions

The purpose of this observational study was (1) to examine the process of parent-adolescent relationship change across puberty, and (2) to examine the relationship between affective expression in interactions and perceived relationship conflict. Data were collected on 85 intact families with adolescents in grades 5 to 9 (n = 44 males, 41 females). Each parent and adolescent took part in two 8-minute conversations one about an activity they reported enjoying together and one about a disagreement or area of conflict. Conversations were coded by speaker turn for positive, negative, neutral, mixed, and altered affect (kappa = .76). Regression analyses indicated that parents and adolescents expressed more negative and less positive affect in interactions as adolescents physically matured. In addition, adolescents' perceptions of relationship conflict were consistently related to parents' expressed emotions in interactions and paralleled trends for positive and negative affect across puberty. Findings are discu...
Hypercoagulability in Heart Failure

Thromboembolism is an important complication in patients with heart failure. A variety of factors associated with heart failure predispose to thrombosis. These include vascular pathology, increased coagulability, and impaired flow. The focus of this review is to summarize data on platelet function and coagulation indices in heart failure. Several studies have shown that patients with heart failure have increased plasma concentrations of beta-thromboglobulin, a marker of platelet activation. Increased plasma concentrations of fibrinopeptide A and thrombin activation have also been demonstrated. In addition, plasma concentrations of endothelial procoagulants, von Willebrand factor, fibrinolytic products, and D-dimer are also increased during heart failure. If platelet activation and hypercoagulability are a surrogate for clinical events, treatment with antiplatelet or anticoagulant therapy can potentially reduce thromboembolism and mortality in heart failure.
Recent Advances in Diagnostic Strategies for Giant Cell Arteritis

Giant cell arteritis (GCA) is a systemic vasculitis that affects the aorta and its major branches. Involvement of the ciliary artery can result in ischemic optic neuropathy and subsequent blindness, which is typically irreversible. If GCA is suspected, treatment with glucocorticoids should be initiated promptly to prevent further vision loss. However, given the need for prolonged therapy with glucocorticoids and the morbidity associated with their use, diagnosis should be confirmed. Clinical features and laboratory findings are neither sensitive nor specific for GCA. The mainstay of diagnosis remains histopathologic examination of a section of the superficial temporal artery. Several imaging studies have been used to evaluate the temporal artery but, at present, their utility as alternatives to a temporal artery biopsy is limited. Recent advances in imaging modalities have allowed detailed noninvasive imaging of the large arteries and are a useful adjunct for the diagnosis of GCA, particularly in patients with primarily large-vessel involvement in whom temporal artery biopsy is often negative.
MO-F-16A-06: Implementation of a Radiation Exposure Monitoring System for Surveillance of Multi-Modality Radiation Dose Data

Purpose: We have implemented a commercially available Radiation Exposure Monitoring System (REMS) to enhance the processes of radiation dose data collection, analysis and alerting developed over the past decade at our sites of practice. REMS allows for consolidation of multiple radiation dose information sources and quicker alerting than previously developed processes. Methods: Thirty-nine x-ray producing imaging modalities were interfaced with the REMS: thirteen computed tomography scanners, sixteen angiography/interventional systems, nine digital radiography systems and one mammography system. A number of methodologies were used to provide dose data to the REMS: Modality Performed Procedure Step (MPPS) messages, DICOM Radiation Dose Structured Reports (RDSR), and DICOM header information. Once interfaced, the dosimetry information from each device underwent validation (first 15–20 exams) before release for viewing by end-users: physicians, medical physicists, technologists and administrators. Results: Before REMS, our diagnostic physics group pulled dosimetry data from seven disparate databases throughout the radiology, radiation oncology, cardiology, electrophysiology, anesthesiology/pain management and vascular surgery departments at two major medical centers and four associated outpatient clinics. With the REMS implementation, we now have one authoritative source of dose information for alerting, longitudinal analysis, dashboard/graphics generation and benchmarking. REMS provides immediate automatic dose alerts utilizing thresholds calculated through dailymore » statistical analysis. This has streamlined our Closing the Loop process for estimated skin exposures in excess of our institutional specific substantial radiation dose level which relied on technologist notification of the diagnostic physics group and daily report from the radiology information system (RIS). REMS also automatically calculates the CT size-specific dose estimate (SSDE) as well as provides two-dimensional angulation dose maps for angiography/interventional procedures. Conclusion: REMS implementation has streamlined and consolidated the dosimetry data collection and analysis process at our institutions while eliminating manual entry error and providing immediate alerting and access to dosimetry data to both physicists and physicians. Brent Stewart has funded research through GE Healthcare.« less
Neurobehavioral assessment before birth

The complexities of neurobehavioral assessment of the fetus, which can be neither directly viewed nor manipulated, cannot be understated. Impetus to develop methods for measuring fetal neurobehavioral development has been provided by the recognition that individual differences in neurobehavioral functioning do not originate with birth and acceptance of the key contribution of the antenatal period to postnatal life. Research has centered around four aspects of fetal functioning: heart rate, motor activity, behavioral state, and responsivity to stimulation. Longitudinal studies have revealed that the developmental trajectories of these characteristics parallel the developing nervous system, detected a transitional period between 28 and 32 weeks gestation, and established within-fetal stability during the second half of gestation. Despite the promise of fetal stimulation and habituation paradigms as measures of neural functioning, significant safety and ethical concerns exist. Construction of a unified fetal neurobehavioral scale is premature until a sufficient degree of normative data is available and the predictive validity of specific aspects of fetal neurobehavior to child developmental outcomes is better established.
Addressing the Mental Health Needs of Victims and Responders to the Boston Marathon Bombings

The response to the Boston Marathon bombings demonstrated the value of networks and collaborative practices in many ways. Although three people died at the scene, all of the remaining injured survived due to the extraordinary care provided by primary care providers, hospitals, ambulance services, other first responders, and citizens. This was also a disaster in which effective mental health care was provided from the start by networks of local, state, and federal organizations and continued for the victims, responders, and the community. It demonstrated the value of integrated behavioral responses as a critical component of all disaster and terrorist attack planning and services. This case study highlights the roles of the agencies involved in the initial response to the attack.
Hartree-fock techniques in the liouville theory of non-equilibrium Fermi systems

Abstract Hartree-Fock resummation techniques are applied to the time-dependent Liouville theory of non-equilibrium Fermi systems. Expressions for the reduced density matrices are obtained in terms of Liouville expansions which depend only upon single-particle energies modified to include the effects of interaction with the medium.
Determination of Fumonisins in Rodent Feed Using HPLC with Electrospray Mass Spectrometric Detection

A method based on liquid chromatography with electrospray ionization mass spectrometry was validated for analysis of low-level contamination of rodent feed by fumonisins B1 (10−200 ppb) and also applied to the analysis of fumonisin B2 and B3. The quantitation limit for a fumonisin B1 standard was 1.1 ppb using the protonated molecule signal (m/z 722), and similar sensitivity was observed for protonated molecules for fumonisins B2 and B3 in feed. To increase specificity of the mass spectrometric analysis, two fragment ions for fumonisin B1 (m/z 352 and 334) were also acquired by using rapid sampling cone-skimmer potential switching in concert with acquisition of the respective ion. This permitted the use of ion intensity ratios for structural confirmation of fumonisin B1 at levels >10 ppb. Intra-assay precision for fumonisin B1 determination in feed (6−16% relative standard deviation) was comparable to inter-assay precision (7.7−16.0%) and appeared to be affected most by the variability in recovery of anal...
Relationship between conjugation length and third-order nonlinearity in bis-donor substituted diphenyl polyenes

In the design of new organic materials with enhanced nonlinear optical activity, it has been predicted that (gamma) , the third order hyperpolarizability (second hyperpolarizability) will not increase indefinitely in a regular fashion as the conjugation length increases. In regular polyenes, for example, (gamma) has been predicted to level off after circa 10 - 15 repeat units. However, very few experimental systems have been investigated in which the number of repeat units approach these limits. Synthetic difficulties and the lack of solubility of longer oligomers has precluded accurate measures of (gamma) in polyenylic series of well- characterized compounds. In the present study, we discuss how long, and branched-chain alkyl groups attached via alkoxy-substituted phenyl rings can greatly increase the solubility of long polyene oligomers for D,D- and D,A- substituent patterns. This allows, for the first time, a comprehensive study of how (gamma) varies with conjugation length and symmetrical versus asymmetrical substitution.
Aquinas and Luther on War and Peace: Sovereign Authority and the Use of Armed Force

Recent just war thought has tended to prioritize just cause among the moral criteria to be satisfied for resort to armed force, reducing the requirement of sovereign authority to a secondary, supporting role: such authority is to act in response to the establishment of just cause. By contrast, Aquinas and Luther, two benchmark figures in the development of Christian thought on just war, unambiguously gave priority to the requirement of sovereign authority as instituted by God to carry out the responsibilities of ensuring a just and peaceful order in the world. On this conception it is the sovereign, in deciding whether to resort to armed force, who must make sure to satisfy the other moral requirements of the jus ad bellum. This paper examines Aquinas and Luther on sovereign authority for use of armed force. Recapturing the importance of this conception is important both for the proper understanding of just war tradition and for working out its implications for such contemporary issues as humanitarian intervention and “regime change.”
An authorization model for temporal and derived data: securing information portals

The term information portals refers to Web sites that serve as main providers of focused information, gathered from distributed data sources. Gathering and disseminating information through information portals introduce new security challenges. In particular, the authorization specifications, as well as the granting process, are temporal by nature. Also, more often than not, the information provided by the portal is in fact derived from more than one backend data source. Therefore, any authorization model for information portals should support access control based on temporal characteristics of the data, and also should provide tools to prevent indirect unauthorized access through the use of derived data. In this article we focus our attention on devising such an authorization model. The distinguishing features of this model include: (1) the specification of authorizations based on temporal characteristics of data, and (2) a formal framework to derive authorizations in a consistent and safe manner, based on relationships among data.
Nonzero-order fringe-adjusted joint transform correlation using binary random phase mask

In this paper, we proposed a new architecture, called nonzero-order fringe-adjusted joint transform correlator (FJTC) using a binary random phase mask, for real time pattern recognition applications. The binary random phase mask encodes the reference image by two equal probability phases before it is introduced in the joint input image. The joint power spectrum is then multiplied by the same phase mask to remove the zero-order term and false alarms that may be generated in the correlation plane due to the presence of multiple identical target or non-target objects in the input scene. The criteria used for measuring the performance of nonzero-order fringe-adjusted JTC include correlation peak intensity, peak-to-correlation energy, and peak-to-sidelobe ratio. Detailed analysis for the proposed nonzero-order FJTC using binary random phase mask is presented. Simulation results verify the effectiveness of the proposed technique.
Chinese Kindergarten Education and Its Reform.

This paper presents a profile of Chinese kindergartens. The problems discussed are related to (a) the provision of kindergarten education, (b) the only child, (c) teacher training, (d) the knowledge base of kindergarten education, and (e) reform of the kindergarten curriculum. The Chinese are reforming the kindergarten to support creativity and individualy. Kindergarten educators are being introduced to Western educational theories. The content, methods, and materials will have to be altered, the administration of kindergarten education modified, and the qualifications for kindergarten teachers improved. Progress in reform will require additional resources for new kindergarten classes and for more and better educational resources, and to improve the qualifications of current teachers and the preparation of incoming teachers, as well as to increase the number of teachers. Chinese kindergarten educators must also modify the curriculum, making it more responsive to the needs of the children and the evolving culture.
Precipitation and dew in a soybean canopy: Spatial variations in leaf wetness and implications for Phakopsora pachyrhizi infection

With the occurrence of soybean rust (Phakopsora pachyrhizi) now a seasonal problem in the United States, increased research is needed to ascertain the potential transmission of this disease among soybean (Glycine max L.) in major growing regions throughout the nation. The fungal disease spores are deposited on leaves in the lower region of the canopy through rain events or wind transport from nearby plants during the growing season and must then have moist conditions on the lower trifoliolates for several hours in order to infect the plant. These moist conditions can be achieved through any form of wetness. This wetness was measured in a soybean canopy at West Lafayette, IN, during the summer of 2007 using resistance-grid wetness sensors located at three heights representative of the top, mid-level, and lowest trifoliate of the canopy. Temperature, relative humidity, wind speed, and precipitation measurements were used to determine the cause of wetness. Over the course of the experiment, wetness events were classified as dew, rain, or neither. The dew events were then compared to rain events with an emphasis on differences in vertical and horizontal duration of wetness. Dew events were found to be the dominant wetness source in the upper canopy. Rain events were the most dominant cause of wetness in the lower canopy. Upper canopy wetness events had the longest duration. Horizontal variation in wetness and wetness duration was large.
Tensile properties and fractography of aged hastelloy B2 (550–850°C for up to 1200 H)

Abstract The 0.2% yield strength and elongation at fracture have been measured at 25°C for Hastelloy B2 samples that were aged for up to 1200 h from 550 to 850°C. This alloy is very similar in composition to the binary Ni-20 at.% Mo alloy. At 550 and 750°C, the strength increased significantly (approximately tripling after 1200 h at 550°C). Upon aging at 750°C, the strength passed through a maximum (of about twice that of the solution-annealed condition) then decresed. In the solution-annealed condition, the ductility is approximately 60%, but after aging at 550 and 850°C for 400 h or more, the ductility was In the ductile condition, the fracture surface topology was dimpled. As aging increased and ductility decreased, the fracture became increasingly intergranular and transgranular. The fracture surface topology is related to the microstructural changes that occur upon aging.
Conformational Changes in a Pore-lining Helix Coupled to Cystic Fibrosis Transmembrane Conductance Regulator Channel Gating

Cystic fibrosis transmembrane conductance regulator (CFTR), the protein dysfunctional in cystic fibrosis, is unique among ATP-binding cassette transporters in that it functions as an ion channel. In CFTR, ATP binding opens the channel, and its subsequent hydrolysis causes channel closure. We studied the conformational changes in the pore-lining sixth transmembrane segment upon ATP binding by measuring state-dependent changes in accessibility of substituted cysteines to methanethiosulfonate reagents. Modification rates of three residues (resides 331, 333, and 335) near the extracellular side were 10–1000-fold slower in the open state than in the closed state. Introduction of a charged residue by chemical modification at two of these positions (resides 331 and 333) affected CFTR single-channel gating. In contrast, modifications of pore-lining residues 334 and 338 were not state-dependent. Our results suggest that ATP binding induces a modest conformational change in the sixth transmembrane segment, and this conformational change is coupled to the gating mechanism that regulates ion conduction. These results may establish a structural basis of gating involving the dynamic rearrangement of transmembrane domains necessary for vectorial transport of substrates in ATP-binding cassette transporters.
Initial historical descriptions of the angina pectoris

The first description of angina pectoris available in history was given in the 17th century by Edward Hyde (1609-1674), a nonmedical person, in his biography, Life of Edward, Earl of Clarendon. The case described is an in-detail history of his father's ailment, which eventually resulted in his sudden death. Although the word Angina Pectoris was not used in this manuscript, the description is very suggestive of it. The first detailed account of the angina pectoris given by a medical person was by Dr. William Heberden (1710-1801) in the 18th century. He used the term Angina Pectoris (Pectoris Dolor) for the first time. Both of these initial historical descriptions of angina pectoris are portrayed.
Lutetium-based Trimetallic Nitride Endohedral Metallofullerenes: New Contrast Agents

We report the isolation and characterization of an endohedral metallofullerene encapsulating three lanthanide atoms inside a nanoscale C80 cage, Lu3N@C80. In addition, we also report encapsulated mixed-metal species of gadolinium/lutetium and holmium/lutetium, Lu3-xAxN@C80 (x = 0−2), which may prove useful as multifunctional contrast agents for X-ray, MRI, and radiopharmaceuticals.
Partial purification and characterization of various β-glucosidases associated with cellular components of corn roots

Abstract β-Glucosidases were isolated from various cellular components from corn root cortical tissue. The subcellular components were separated and the enzymes were partially purified and characterized. The pH-activity profile of the cytosolic enzyme and the unidentified particulate-associated β-glucosidase were identical. Further kinetic analyses of these two enzymes at pH 5.5 and 7.5 suggests that the unidentified particulate-associated β-glucosidase is the bound from of the cytosolic enzyme. The ionically bound cell wall enzyme (in muro) had a pH optimum of 5.5 while the free from (salt solubilized) had a pH optimum of 5.0. The enzyme kinetics of the extracellular enzymes were compared to the intracellular forms with particular reference to bound versus free enzymes. The K m values and the shape of the kinetic curves of free enzymes were not changed when enzymes were assayed in the bound state. The tightly bound cell wall enzyme had a very broad pH-activity profile and had a K m value approximately one-half the K m value of the other β-glucosidases.
LOWTRAN 7 comparisons with field measurements

This paper presents comparisons between LOWTRAN 7 and field measurements taken during a number of field tests conducted by the US ARMY Center for Night Vision and Electro- Optics at several different locations. The data was collected by the TECOM Ft Belvoir Meteorological Team. Data includes transmission at 0.4 - 0.7 microns, 1.54 microns, 3 - 5 microns, and 8 - 12 microns. A brief description of the equipment and meteorological parameters are presented along with the measured transmission and calculations using LOWTRAN 7 and in one example, MODTRAN.
Synthesis of syn- and anti-1-amino-3-[18F]fluoromethyl-cyclobutane-1-carboxylic acid (FMACBC), potential PET ligands for tumor detection.

syn- and anti-1-Amino-3-[18F]fluoromethyl-cyclobutane-1-carboxylic acid (FMACBC, 16 and 17), analogues of anti-1-amino-3-[18F]fluorocyclobutyl-1-carboxylic acid (FACBC), were prepared to evaluate t...
The maxillary complete denture opposing natural teeth: Problems and some solutions

The problems involved in providing comfort, function, proper esthetics, and retention for the maxillary complete denture patient with natural opposing dentition can be challenging. Careful preparation of the patient is important. It provides the new complete denture patient the opportunity to adapt to a complete denture and allows the dentist to evaluate his patient physically and emotionally before fabrication of the final complete denture. Methods for planning and fabrication of a denture that provide comfort, function, and stability have been described.
A Generalized Inland Fishery Simulator for Management Biologists

Abstract Presently available fishery models are either too simplified or too complicated to be useful to inland fishery managers. This research was directed toward developing a simplified but realistic computerized simulator useful to fishery managers. The model developed is basically an age-class structured simulator with features built in to allow easy but effective use by fishery managers. It includes provisions for input of all important parameters plus provisions for density-dependent relationships where applicable. Examples of model use are given for a put-and-take rainbow trout (Salmo gairdneri) fishery and a self-sustaining walleye (Stizostedion vitreum) population.
Identification of Cable Forces on Cable-Stayed Bridges: A Novel Application of the MUSIC Algorithm

Proper identification of the cable’s resonant frequencies is critical to provide an accurate estimate of cable force. The MUltiple SIgnal Classification (MUSIC) algorithm is implemented to estimate cable-stayed bridge cable tensions noninvasively from measured cable motion. This algorithm performs eigenanalysis on the data sequence to estimate and eliminate noise contributions before creating its frequency spectrum, providing a more robust estimation approach than traditional Fourier based frequency spectrums. To aid in the selection of cable frequencies, a comprehensive finite difference cable model is simulated and compared to the estimated MUSIC spectrums.
Photoexcitation and Auger decay of the Renner-Teller split C 1s{sup -1} {pi}{sub u}{sup *} state in CO{sub 2}

The broad $(\ensuremath{\approx}700$ meV) C $1\stackrel{\ensuremath{\rightarrow}}{s}{\ensuremath{\pi}}_{u}^{*}$ resonance in the absorption spectrum of ${\mathrm{CO}}_{2}$ has been decomposed into contributions from two Renner-Teller split core-excited states with bent and linear equilibrium geometries using resonant Auger spectroscopy. The C ${1s}^{\ensuremath{-}1} {\ensuremath{\pi}}^{*}$ excited state was found to decay primarily via participator Auger transitions to the $A{}^{2}{\ensuremath{\Pi}}_{u}$ state of ${\mathrm{CO}}_{2}^{+}.$ Analysis of the vibrational structure in the high-resolution Auger spectra, measured at several photon energies across the broad C $1\stackrel{\ensuremath{\rightarrow}}{s}{\ensuremath{\pi}}_{u}^{*}$ resonance, was accomplished using calculated Franck-Condon factors for the electronic excitation and de-excitation processes. Estimations of the geometries of the Renner-Teller split core-excited states were obtained from a comparison of the calculations with the resonant Auger spectra. Transitions to the bent core-excited state were found to contribute to the absorption profile exclusively at the photon energies below the maximum of the C $1\stackrel{\ensuremath{\rightarrow}}{s}{\ensuremath{\pi}}_{u}^{*}$ resonance, whereas the linear core-excited state becomes accessible at higher photon energies. The symmetric stretch vibrational progression of the linear core-excited state was identified and assigned. The minimum of the potential energy surface of the C ${1s}^{\ensuremath{-}1}{\ensuremath{\pi}}^{*}$ core-excited state at its linear configuration was estimated to be 290.4 eV above the ground vibrational level of the ground electronic state of ${\mathrm{CO}}_{2}.$
Another Horse in the Meta-Stable State of Pluripotency

Reports of heterogeneity within embryonic stem cell lines suggest that pluripotent stem cells captured in culture may be less homogeneous than previously assumed. In a recent issue of Cell , Scholer and colleagues (Han et al., 2010) demonstrate the existence of a dynamic subpopulation of epiblast stem cells that shows features of earlier pluripotent cells.
Critical Analysis of the Thermodynamic Data for Pt and a Prediction of Θ DW ( T )

The available thermodynamic data for Pt are reviewed. A ${\ensuremath{\Theta}}^{c}(T)$ curve is constructed, and anharmonicity and volume expansion are explicitly allowed for. Values of ${〈{\ensuremath{\omega}}^{n}〉}_{\mathrm{av}}$ for both positive and negative $n$ are derived and correlated in the usual way, by constructing a Barron plot. The ${\ensuremath{\Theta}}_{\mathrm{DW}}(T)$ versus $T$ curve is constructed by using a Pad\'e approximant to link the high- and the low-temperature expansion. The resultant ${\ensuremath{\Theta}}_{\mathrm{DW}}(T)$ is corrected for the volume expansion. Other anharmonic effects in ${\ensuremath{\Theta}}_{\mathrm{DW}}(T)$ are neglected for $T\ensuremath{\lesssim}\ensuremath{\Theta}$. We find ${\ensuremath{\Theta}}_{\mathrm{DW}}(O)=(232\ifmmode\pm\else\textpm\fi{}3)\ifmmode^\circ\else\textdegree\fi{}$K and ${\ensuremath{\Theta}}_{\mathrm{DW}}(\ensuremath{\infty})=(231\ifmmode\pm\else\textpm\fi{}3)\ifmmode^\circ\else\textdegree\fi{}$K. These results are compared with experiment in the preceding paper by Harris, Benczer-Koller, and Rothberg.
The solubility of gases in liquids. 5. The solubility of N2, O2, CO, and CO2 in cyclohexane at 283 to 313 K

The solubilities of N2, O2, CO, and CO2 in cyclohexane were determined at atmospheric pressure in the range 283 to 313 K. The solubility, Gibbs energy, enthalpy, and entropy of solution for 1 atm partial pressure of gas and 298.15 K were calculated from the experimental results. These values were compared with results calculated by use of the scaled particle theory.
Kinetic Mechanism for the Excision of Hypoxanthine by Escherichia coli AlkA and Evidence for Binding to DNA Ends

The integrity of the genome is challenged by spontaneous reactions that modify the nucleobases of DNA. These deleterious reactions include oxidation, deamination, and a variety of alkylation reactions involving endogenous metabolites and exogenous reactive compounds. Failure to repair these many forms of DNA damage can block DNA-templated activities such as transcription and replication and lead to permanent mutations or cell death (1, 2). The base excision repair (BER) pathway corrects the majority of damaged bases. This pathway is initiated by a DNA glycosylase that searches the genome to locate the sites of damage and then catalyzes the hydrolysis of the N-glycosidic bond to release the base lesion and create an abasic site. Downstream enzymes subsequently process this abasic site and use the information on the undamaged strand to restore the original coding sequence. Escherichia coli contains two 3-methyladenine DNA glycosylases that are encoded by the tag and alkA genes (3). Tag (3-methyladenine DNA glycosylase I) is constitutively expressed and has high specificity for 3-methyladenine. In contrast, AlkA (3-methyladenine DNA glycosylase II) is induced as part of adaptive response to alkylation stress and recognizes a diverse group of damaged bases (3, 4). Studies exploring potential substrates for AlkA have established glycosylase activity toward more than a dozen lesions, including the alkylation adducts 3mA, 7mG, and 1,N6-ethenoadenine (eA), and the deaminated bases hypoxanthine (Hx) and xanthine (5–9). Many of the alkylated nucleotides have unstable N-glycosidic bonds and they are difficult to work with, but previous work suggests that AlkA has similar rate enhancements for a wide range of disparate lesions (10). We have focused on the excision of Hx, because the homogenous substrate can be prepared and it has a stable N-glycosidic bond. A wealth of structural information is available for the interaction of AlkA with DNA. AlkA has been crystallized in complex with a 1-azaribose transition state analog (11) and there are several structures of AlkA bound to the ends of oligonucleotides (12, 13). Most recently, engineered protein-DNA crosslinks were used to obtain structures of AlkA interacting with undamaged DNA (14). Remarkably, all of these structures show a very similar overall set of protein-DNA interactions with only subtle rearrangements that are localized to the active site pocket and neighboring residues (14). Mechanistic insights into the AlkA reaction have lagged behind the structural studies. In the current work we have characterized the single- and multiple-turnover kinetics for excision of Hx from oligonucleotides in which the lesion is located different distances from the ends. Comparison of these substrates provides evidence that AlkA binds to DNA ends more tightly than to Hx lesions, and this restricts the binding of subsequent AlkA protamers. We identified a well-behaved substrate that is amenable to kinetic studies and describe the minimal kinetic mechanism for recognition and excision of Hx.
Methylation and processing of mitochondrial ribosomal RNAs in poky and wild-type Neurospora crassa

Abstract Mitochondrial ribosomal RNAs (25 S and 19 S) are produced by cleavage of a common high molecular weight precursor (32 S), which is a transcript of mitochondrial DNA. The poky strain in Neurospora crassa is characterized by a deficiency of mitochondrial small-subunit ribosomes. Pulse-labeling studies were carried out in poky indicating that the maturation and cleavage steps, which lead to the production of mitochondrial ribosomal RNAs, are abnormal. Studies of RNA methylation in methionine-requiring strains were also made. In control cells, the time course of incorporation of [C3H3]methionine label into mitochondrial RNAs, and the contents of methyl groups in the RNAs suggest that 32 S RNA is the major site for methylation. In poky, mitochondrial 25 S and 19 S RNAs have methyl contents of approximately 70% and 55%, respectively, of control values. The cytoplasmic ribosomal RNAs and mitochondrial 4 S RNAs, by contrast, show no differences between poky and control cultures. It is concluded that in poky, most of the putative 19 S RNA is degraded before it is incorporated into small ribosomal subunits. This defect could be a consequence of undermethylation, or both defects could result from a primary abnormality yet undefined.
Recurrent pancreatitis: a complication secondary to a retained pancreaticojejunostomy splint

Chronic recurrent pancreatitis is defined as chronic pancreatitis with periods of acute exacerbations. Alcohol abuse l is the most common cause of it in the United States and kwashiorkor in the underdeveloped countries. It has also been observed in patients with hyperlipidemia, hyperparathyroidism and hypercalcemia, pancreatic divisum,3. 4 biliary tract disease/' and rare genetic predisposition. To our knowledge there has been no case of foreign body in the pancreatic duct causing recurrent pancreatitis in the English literature. The following report is a case of recurrent pancreatitis secondary to a retained pancreaticojejunostomy splint.
Cutaneous and subcutaneous leiomyosarcoma: a clinicopathological review of 14 cases with reference to antidesmin staining and nuclear DNA patterns studied by flow cytometry

Summary Among 14 patients (11 female and three male) with cutaneous and subcutaneous leiomyosarcomas, metastatic spread occurred in six of the 13 patients with adequate follow-up. The tumours were classified with regard to tumour grade, number of mitotic figures per 10 high-power fields, reactivity to antidesmin antibodies, and DNA pattern as assessed by flow cytometry. Antidesmin antibody staining was present in only six cases and seemed to be less common in the higher-grade tumours. The DNA pattern was aneuploid in five cases and non-classifiable in one case: all of these cases had metastatic spread. None of the eight remaining diploid cases had metastatic spread. DNA content was a strong predictor of metastatic potential.
Isolation of plasma lipoproteins by a combination of differential and density gradient ultracentrifugation

A method for preparative isolation of serum lipoproteins by a combination of differential and density gradient ultracentrifugation is presented. Total plasma lipoproteins are first isolated in a concentrated form by ultracentrifugation in a fixed angle rotor at a plasma background density of 1.21 kg/l. Subsequently, the various lipoprotein classes are separated by density gradient ultracentrifugation in a swinging bucket rotor. The procedure requires only two ultracentrifugation steps and combines advantages of both ultracentrifugation techniques.
Companion problems in quasispin and isospin

We note that the same mathematical results apply to problems involving quasispin and isospin, but the problems per se are different. In the quasispin case, one deals with a system of identical fermions (e.g., neutrons) and addresses the problem of how many seniority-conserving interactions there are. In the isospin case, one deals with a system of both neutrons and protons and the problem in question is the number of neutron-proton pairs with a given total angular momentum. Other companion problems are also discussed.
α-Tocopherol in the developing rat retina: A high pressure liquid chromatographic analysis

High pressure liquid chromatography was used to measure alpha-tocopherol in the retinas of rats reared in a cyclic light or dark environment. These measurements were performed on extracts of whole retinas during the developmental period, 18-60 days, and on isolated ROS from adult animals. Similar alpha-tocopherol determinations were performed on retinas and isolated ROS following exposure of rats to intense visible light for 24 hr periods. The results show that alpha-tocopherol is chromatographically separated from the vitamin A derivatives found in the retina and is pure, as judged by mass spectrometry. In the retinas of cyclic light and dark reared rats, alpha-tocopherol accumulates in an age dependent fashion, so that at 60 days the level is nearly double that of animals at 18-20 days of age (P less than 0.001). Because the age dependent accumulation of rhodopsin is greater in dark reared rats, the average molar ratio of rhodopsin to alpha- tocopherol in the retina of dark reared animals is 25% higher than in cyclic light rats. Following exposure of rats to intense visible light for 24 hr periods, alpha-tocopherol concentrations in the retina were unchanged from the levels in control animals. In adult animals the concentration of alpha-tocopherol in ROS is 2.5-3.5 times higher than in whole retina. ROS from adult cyclic light reared rats also contain an average of 43% more alpha-tocopherol per mg protein than ROS from dark maintained animals (P less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)
Mass spectrometry imaging of small molecules using desorption/ionization on silicon.

Development of novel tools to image spatial distribution of small molecules in biological samples is essential in disease diagnosis and biomarker discovery. To simplify sample preparation and reduce background noise in the low-mass region, we describe here the use of a matrix-free mass spectrometric imaging method, i.e., desorption/ionization on silicon (DIOS), for biological surface analysis. The imaging parameters, such as the laser beam diameter and the translation stage movement, were studied and optimized to improve imaging performance. The use of DIOS imaging to map small molecules on mouse liver tissues was demonstrated. In addition, phosphatidylcholine (PC) and propidium iodide (PI) were used as the cell membrane and nucleus markers, respectively, to “visualize” the presence of HEK 293 cells. The reconstructed ion maps of PC and PI were compared with the optical images collected from the same sample using bright-field and fluorescence microscopy. A good correlation of the spatial distribution of c...
On the physics of Aitken particles in polar air mass systems

Abstract Experiments on the size distribution of Aitken nuclei (AN) (suspended particles of radius r ≲ 10 −5 cm) indicate that the mean radius of the AN in cold, Arctic-derived air masses is larger than in warm, Pacific marine air mass systems. We hypothesize that this is due predominantly to loss of the smallest, highly mobile, particles by diffusive attachment to cloud droplets during the time when the air mass resides in the semidarkness of the polar night. While air masses meander in the polar regions it is hypothesized that particle production by nucleation ceases. A model is developed to interpret the relationship between size and airmass types. Pacific Marine air masses are inferred to have been exposed on average for about 10 h in cloud, while Arctic air on average has been in clouds for 2 days. The length of the time during which cloud scavenging can occur is consistent with estimated frequency of cloud occurrence and residence times of air masses in the Arctic.
An experimental and theoretical study of growth in horizontal epitaxial reactors

In this paper we describe an experimental and theoretical study of the effects of susceptor slope and natural convection on the growth rate in horizontal epitaxial reactors. A mathematical model for mass, momentum and energy transfer was developed for this purpose. The growth of gallium arsenide by the reaction of trimethylgallium and arsine gas in hydrogen was used as the experimental vehicle for this study. The growth rates predicted by this model were compared with experimental data for reactor pressures from 76–760 Torr and for susceptor slopes spanning the range from conventional low angle (7°) to near stagnation flow geometries (81°). Excellent correlation between modeled and experimental results was demonstrated over this range of susceptor slopes, with no adjustable parameters. Natural convection effects were found to dominate at higher reactor pressure and steeper susceptor slopes. Growth rate uniformity and growth efficiency issues are also discussed in this paper. It is shown that, for the reactor geometry considered here, the usable area growth efficiency is maximized for susceptor slopes around 5°. However, optimization of this parameter is not of itself sufficient, since material quality considerations necessitate operation at pressures where recirculation effects are absent.
The viscoelastic and aging characteristics of polymers

Study of mechanics for polymeric materials must consider both geometric and material nonlinearities. The additional viscoelastic and aging effects make the analytical study very difficult. In this paper, the viscoelastic effect of polymers subjected to simple extension is presented. The constitutive equation developed by Christensen is used. With two more material property functions, the constitutive equation is extended to include the aging effect of polymers. In experiments, the relaxation data for both unaged and aged specimens are obtained. Based on the formulation and test data, the viscoelastic and aging material properties are determined.
A knowledge-based system for the determination of activity indicators for self-adaptive grid methods

Abstract Many important physical problems exhibit phenomena that require local grid resolution. Activity indicators are used by local grid refinement schemes to determine where to place or remove local grids, in order to achieve a better accuracy on the numerical procedure. We present a methodology for the selection of activity indicators and show how to automate the process using a knowledge-based system that adjusts its parameters based on its previous experiences with similar problems. The methodology is: a class of model problems is constructed; then we specify the set of relevant parameters to be used in the quantification of the results obtained when solving a problem with a particular indicator. A database is created to maintain all the parameters used in the quantification process, as well as the particular scores for each indicator. For each problem, the database is updated and the total scores are modified to reflect the new experience. As the number of problems considered increases, the scores in the database will stabilize providing information about the relative “goodness” of each indicator.
Baboon lipoprotein lipase: cDNA sequence and variable tissue-specific expression of two transcripts.

Abstract We have isolated two lipoprotein lipase (LPL)-encoding cDNA ( LPL ) clones from a baboon cardiac cDNA library, one of which spans a region from nucleotide (nt) 705 of the coding sequence to the poly(A) tail (2.8 kb). We used reverse transcription followed by PCR (RT-PCR), and anchor-ligated rapid amplification of cDNA ends (RACE) to amplify the remaining 5' region of the LPL transcript. Sequence comparisons reveal that the baboon nt sequence is 95% identical to the human cDNA sequence (ranging from 97.5 to 92.7% in the coding and noncoding regions, respectively). Less than 2% of nt substitutions cause changes between baboon and human amino acid (aa) sequences. The aa in the catalytic triad residues, the heparin-binding site in exon 6, as well as aa in positions where missense mutations cause LPL deficiency, are identical in baboons and humans. Characterization of the tissue-specific expression of LPL using Northern blots of total RNA showed that spinal cord expressed the most LPL transcripts of all baboon tissues examined. Like humans, baboons have two transcript sizes of approx. 3.6 and 3.4 kb in most tissues that express LPL, and sequencing of the 3' untranslated region (UTR) shows this is due to two polyadenylation sites. In contrast, only the larger 3.6-kb transcript is detected in RNA isolated from central nervous system (CNS) tissues. We used RT-PCR to show that the polyadenylation signal that produces the 3.4-kb message is present in CNS LPL transcripts, but is not utilized.
Planck−Benzinger Thermal Work Function: Thermodynamic Approach to Site-Specific S-Protein and S-Peptides Interactions in the Ribonuclease S‘ System

The Planck−Benzinger thermal work function ΔW(T) represents the strictly thermal components of any intra- or intermolecular bonding term in a system, that is, energy other than the inherent difference of the 0 K portion of the interaction energy. The latter, the temperature-invariant enthalpy, is the only energy term at absolute zero Kelvin. The magnitude of ΔH(T0) or ΔH°(T0), the temperature-invariant enthalpy, is determined by the type of macromolecular interaction taking place under experimental conditions, and thus, this thermodynamic function should be particularly applicable to studies on the ribonuclease S-protein interaction with S-peptides with various substitutions at methionine-13. Values for ΔH(T0) for the S-protein−S-peptides interaction with such substitution at Met-13 were determined to be 25.67 ± 0.63 (Met-13 → Ala), 85.69 ± 0.35 (Met-13 → Phe), and 22.32 ± 0.19 kcal mol-1 (Met-13 → α-amino-N-butyric acid). A possible model for the fragment complementation reaction of S-peptide with S-prot...
Preferential Cocrystallization among Distyrylbenzene Derivatives

A combination of powder and single-crystal X-ray diffraction techniques were used to probe the generality of phenyl−perfluorophenyl stacking among a small library of 1,4-distyrylbenzene derivatives. The specific derivatives in the present study are 1,4-bis-(4-dimethylaminostyryl)benzene (DMADSB), 1,4-distyrylbenzene (DSB), 1,4-di(1-cyano-2-phenylethenyl)benzene(CNDSB), 1,4-di(1-cyano-2-(4-methylphenyl)ethenyl)benzene (MeCNDSB) 1,4-bis(styryl)-2,5-difluorobenzene (2Fc), 1,4-bis(4-fluorostyryl)-2,5-difluorobenzene (2Fc2Ft), 1,4-bis(pentaflourostyryl)benzene (10Ft), and 1,4-bis(pentafluorostyryl)-2,5-difluorobenzene (2Fc10Ft). Electrostatic distribution diagrams aid in assessing the likelihood of success in pair formation. Powder diffraction provides a means to determine both positive and negative results for binary phase formation. Four new structures are presented and discussed including (DSB/2Fc10Ft), (DMADSB/2Fc10Ft), (CNDSB/2Fc10Ft), and (MeCNDSB/2Fc10Ft). Single-crystal diffraction work confirms that t...
Pediatric salivary gland lesions

The salivary glands comprise three main pairs of glands (ie, the parotid, the submandibular, and the sublingual) and a number of minor glands found in the mucosa of the upper aerodigestive tract. Lesions may be inflammatory or obstructive in nature or may stem from granulomatous or neoplastic disease. As such, establishing a definitive diagnosis is often quite challenging. This article reviews widely used diagnostic approaches and briefly describes various salivary gland lesions within an etiologic framework.
BRER RABBIT, A PLAY OF THE HUMAN SPIRIT: RECREATING BLACK CULTURE THROUGH BRER RABBIT STORIES

For centuries, Brer Rabbit stories have communicated the values and experiences of enslaved Africans and of indigenous African American culture (Abrahams, 1985; Brewer, 1968; Levine, 1977). According to Blassingame (1972, p. 127), Brer Rabbit stories are “a projection of the slave's personal experiences, dreams and hopes.” Dunn (1979, p.183) explained that the stories are “paradigms dictating how to act and how to live,” and Stuckey (1977, p.xuii) observed that they “revealed more about slave culture than… whole books on slavery by experts. Levine (1977) maintaned that Brer Rabbit stories survived the experiences of slavery and urban poverty because they were a vehicle by which African American cultural values could be shared by the masses of African American people, and Leslie (forthcoming) observed that urban Black mothers continue to share in these values by teaching their children that Brer Rabbit's tricks demonstrate the importance of “protecting the physically small and weak against the physically big and powerful.”