cssi/SciSciGPT-SciSciNet huggingface dataset:
Cystic fibrosis HRCT scores correlate strongly with Pseudomonas infection.

Background In order to establish a valid surrogate outcome measure, it must be shown that the outcome measure (chest HRCT scores in cystic fibrosis [CF] patients) demonstrates strong statistical association with established endpoints of disease, such as Pseudomonas aeruginosa (Pa) airway acquisition, acute exacerbations, or mortality. Methods We estimated and tested the association between Pa infection status (Pa+ vs. Pa−) and baseline chest HRCT scores in 25 children with mild-to-moderate CF lung disease. For comparison, we estimated the association between Pa status and pulmonary function tests (PFTs), chest X-rays (CXR) scores, and BMI. Pa acquisition was determined from respiratory culture results and systematic review of clinic notes. Results All subjects had respiratory cultures performed prior to or at baseline with a median of 19 months of retrospective culture observation (SD = 15.7 months, range: 0–52.5 months). The difference between age-adjusted mean total HRCT score for Pa+ versus Pa− was highly significant (P < 0.00001) with a near-perfect separation between scores in Pa+ versus Pa− patients. Similar results were found for several HRCT sub-scores. Among PFTs, only residual volume-to-total lung capacity (RV/TLC) had a significant difference between group means (P = 0.03), but the overlap between groups in RV/TLC measurements was large. Conclusions CF HRCT scores correlate highly with Pa acquisition, a clinically meaningful measure of progressing CF lung disease. HRCT scores are highly sensitive at predicting Pa acquisition status, while most PFT measures, chest radiograph (CXR) scores, and body mass index are not. These results provide further evidence that HRCT is appropriate for use in patient care and as an outcome measure in clinical trials. Pediatr Pulmonol. 2009; 44:1107–1117. ©2009 Wiley-Liss, Inc.
KNOTS AND EXOTIC SMOOTH STRUCTURES ON 4-MANIFOLDS

In this paper we give a short survey of exotic smooth structures of 4-manifolds. Various methods of constructing exotic structures and their relation to “Shake-Sliceness” and the Zeeman conjecture is discussed.
Complex dynamics and the stimulated gain spectrum of pentylcyanobiphenyl in the isotropic phase

Abstract We have measured high resolution polarized and depolarized stimulated gain spectra of the liquid crystal pentylcyanobiphenyl (5CB) in its isotropic phase between 36.2 and 122°C. Spectral features associated with slow collective reorientation, acoustic waves (Brillouin peaks), and rapid anisotropy fluctuations are all present and can be simultaneously measured with high resolution in a single spectrum. Our results for both the slow and intermediate timescale reoirientational dynamics are in good agreement with recent transient-grating optical Kerr effect measurements on 5CB.
The proteasome regulates caspase-dependent and caspase-independent protease cascades during apoptosis of MO7e hematopoietic progenitor cells.

Abstract ABSTRACT: Withdrawal of trophic support from growth factor-dependent MO7e human myeloid progenitor cells induces apoptosis characterized by DNA fragmentation and degradation of the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs). Inhibitors of caspase (ICE) protease family members did not inhibit apoptosis or DNA fragmentation induced by factor withdrawal, but blocked degradation of DNA-PKcs. Thus, caspase activity accounts for only a component of the apoptotic program in MO7e hematopoietic cells. The protease inhibitor TPCK, but not other protease inhibitors, blocked DNA fragmentation, but not degradation of DNA-PKcs during apoptosis of MO7e cells. Thus, caspase-independent and caspase-dependent protease cascades mediate distinct features of MO7e cell apoptosis. The proteasome inhibitors calpain inhibitor I and lactacystin promoted DNA fragmentation, degradation of DNA-PKcs and apoptosis of MO7e cells. The ability of lactacystin to promote DNA fragmentation was abrogated by TPCK, but not by caspase inhibitors, whereas the ability of lactacystin to promote degradation of DNA-PKcs was blocked by caspase inhibitors, but not by TPCK. Thus, caspase-dependent and caspase-independent protease cascades are downstream of and regulated by the proteasome, which plays a central role in regulating the multiple protease cascades that induce apoptosis.
Multiring techniques for scalable battlespace group communications

Network-centric warfare must leverage off a common network to support different purposes. While group communications based on a single virtual ring overlay may satisfy the most important requirements for survivability and security, scalability may for cc redesign because a single ring generally has higher delay and delay jitter. In order to provide scalability as the number of group members grows, large single rings may be broken into, smaller multirings interconnected together. Thus, comparing the characteristics of different multiring techniques provides insight into which battlespace applications may be supported via virtual rings. In this article we consider different approaches to providing scalable battlespace group communications using multi-ring techniques, classifying the techniques according to the primary military requirements of QoS, security, and survivability. Some important design issues of multiring techniques, such as the number of ring levels and number of rings per level, are dependent on, application QoS requirements and the underlying network infrastructure in terms of topology (dense vs. sparse) and link bandwidths (bottleneck capacities). Through our survey, we conclude that while no existing multiring scheme provides the single solution to battlespace group communications, some aspects of existing multiring schemes do match specific scenarios and provide us useful insights for designing new schemes for battlespace group communication. To our knowledge, this is the first article to survey and categorize multiring algorithms.
A p* primer: logit models for social networks

Abstract A major criticism of the statistical models for analyzing social networks developed by Holland, Leinhardt, and others [Holland, P.W., Leinhardt, S., 1977. Notes on the statistical analysis of social network data; Holland, P.W., Leinhardt, S., 1981. An exponential family of probability distributions for directed graphs. Journal of the American Statistical Association. 76, pp. 33–65 (with discussion); Fienberg, S.E., Wasserman, S., 1981. Categorical data analysis of single sociometric relations. In: Leinhardt, S. (Ed.), Sociological Methodology 1981, San Francisco: Jossey-Bass, pp. 156–192; Fienberg, S.E., Meyer, M.M., Wasserman, S., 1985. Statistical analysis of multiple sociometric relations. Journal of the American Statistical Association, 80, pp. 51–67; Wasserman, S., Weaver, S., 1985. Statistical analysis of binary relational data: Parameter estimation. Journal of Mathematical Psychology. 29, pp. 406–427; Wasserman, S., 1987. Conformity of two sociometric relations. Psychometrika. 52, pp. 3–18] is the very strong independence assumption made on interacting individuals or units within a network or group. This limiting assumption is no longer necessary given recent developments on models for random graphs made by Frank and Strauss [Frank, O., Strauss, D., 1986. Markov graphs. Journal of the American Statistical Association. 81, pp. 832–842] and Strauss and Ikeda [Strauss, D., Ikeda, M., 1990. Pseudolikelihood estimation for social networks. Journal of the American Statistical Association. 85, pp. 204–212]. The resulting models are extremely flexible and easy to fit to data. Although Wasserman and Pattison [Wasserman, S., Pattison, P., 1996. Logit models and logistic regressions for social networks: I. An introduction to Markov random graphs and p*. Psychometrika. 60, pp. 401–426] present a derivation and extension of these models, this paper is a primer on how to use these important breakthroughs to model the relationships between actors (individuals, units) within a single network and provides an extension of the models to multiple networks. The models for multiple networks permit researchers to study how groups are similar and/or how they are different. The models for single and multiple networks and the modeling process are illustrated using friendship data from elementary school children from a study by Parker and Asher [Parker, J.G., Asher, S.R., 1993. Friendship and friendship quality in middle childhood: Links with peer group acceptance and feelings of loneliness and social dissatisfaction. Developmental Psychology. 29, pp. 611–621].
Duopolists’ Retail Pricing Behavior in Multiple Markets

The law of one price asserts that, with costless trade, prices for identical goods in different countries should be equal after accounting for the exchange rate. The empirical literature suggests that exchange rate pass-through to prices is low and that the law of one price fails; instead, firms are more likely to price to market. This study adds to the literature by examining the pricing strategy of comic book firms within the context of the competition’s pricing behavior in a duopoly industry. Comic books, uniquely, display their retail prices in multiple countries on their cover giving us detailed information about the pricing behavior of each individual firm and their competition which allows us to test a pricing-to-market model. We find that an empirical model of an imperfectly applied law of one price outperforms a simple competitive, pricing-to-market model of pricing. Retail exchange rate pass-through rates between Canada and the United States average 76.8 %. This high exchange rate pass-through rate for comic books exists despite the existence of sticky prices and convenience pricing.
Characterization of methamphetamine effects on the striatal-nigral dynorphin system

Abstract Multiple high doses of methamphetamine (METH) induced 200–300% increases in the concentration of striatal and nigral dynorphin-like immunoreactivity (DLI). Increases in striatal and nigral DLI levels also were seen within 6 h following a single administration. The changes in the striatal-nigral dynorphin system had subsided 48 h after either acute or multiple treatments with METH. Selective lesioning of the nigral-striatal dopamine pathway blocked the effects; thus, the METH-induced changes appeared to be mediated by dopamine released from the nigral-striatal dopamine projection. Administration of the METH analog, 3,4-methylenedioxymethamphetamine, appeared to alter striatal and nigral DLI concentrations in a manner similar to that of METH.
Inhibition of arachidonic acid release by nordihydroguaiaretic acid and its antioxidant action in rat alveolar macrophages and Chinese hamster lung fibroblasts.

Abstract The ability of nordihydroguaiaretic acid (NDGA) to inhibit arachidonic acid (AA) release from rat alveolar macrophages treated with t -butyl hydroperoxide (tBOOH) or from Chinese hamster lung fibroblasts (V79 cells) treated with linoleic acid hydroperoxide (LOOH) was examined. Treatment of alveolar macrophages with 100 μ m tBOOH significantly increased arachidonic acid release and its conversion to metabolites. Pretreatment of macrophages with NDGA (≥2.5 μ m ) inhibited the release of AA and its subsequent metabolism following addition of tBOOH. Treatment of V79 cells with 1 μ m LOOH stimulated the release of AA. Pretreatment with either 1 or 10 μ m NDGA prior to the addition of LOOH inhibited the release of AA. A23187 (2 μ m )-stimulated release of AA from V79 cells was less sensitive to NDGA inhibition. Pretreatment with 10 μ m NDGA, but not with 1 μ m NDGA, inhibited A23187-stimulated release of AA. PLA 2 -dependent hydrolysis of micelle preparations of disaturated phosphatidylcholine was not inhibited by NDGA. Previous studies have suggested that the addition of peroxides alters cells by inducing lipid peroxidation so that the action of phospholipases upon their membranes is enhanced. The results suggest that NDGA, a lipid-soluble antioxidant which traps free radicals, indirectly blocked the action of phospholipases upon cell membranes by inhibiting lipid peroxidation.
A method to predict blood-brain barrier permeability of drug-like compounds using molecular dynamics simulations.

The blood-brain barrier (BBB) is formed by specialized tight junctions between endothelial cells that line brain capillaries to create a highly selective barrier between the brain and the rest of the body. A major problem to overcome in drug design is the ability of the compound in question to cross the BBB. Neuroactive drugs are required to cross the BBB to function. Conversely, drugs that target other parts of the body ideally should not cross the BBB to avoid possible psychotropic side effects. Thus, the task of predicting the BBB permeability of new compounds is of great importance. Two gold-standard experimental measures of BBB permeability are logBB (the concentration of drug in the brain divided by concentration in the blood) and logPS (permeability surface-area product). Both methods are time-consuming and expensive, and although logPS is considered the more informative measure, it is lower throughput and more resource intensive. With continual increases in computer power and improvements in molecular simulations, in silico methods may provide viable alternatives. Computational predictions of these two parameters for a sample of 12 small molecule compounds were performed. The potential of mean force for each compound through a 1,2-dioleoyl-sn-glycero-3-phosphocholine bilayer is determined by molecular dynamics simulations. This system setup is often used as a simple BBB mimetic. Additionally, one-dimensional position-dependent diffusion coefficients are calculated from the molecular dynamics trajectories. The diffusion coefficient is combined with the free energy landscape to calculate the effective permeability (Peff) for each sample compound. The relative values of these permeabilities are compared to experimentally determined logBB and logPS values. Our computational predictions correlate remarkably well with both logBB (R2 = 0.94) and logPS (R2 = 0.90). Thus, we have demonstrated that this approach may have the potential to provide reliable, quantitatively predictive BBB permeability, using a relatively quick, inexpensive method.
Arbuscular mycorrhizal development in three crucifers

To determine the developmental patterns of arbuscular mycorrhizae (AM) in three crucifers (Brassicaceae) of differing life histories, we inoculated seedlings of the annual Capsella bursa-pastoris, biennial Hesperis matronalis, and the perennial Matthiola incana with Glomus intraradices. The plants were grown either alone or in a matrix of living roots of the mycotrophic grass Sorghum sudanense. The percent root length colonized was greatest in C. bursa-pastoris and least in H. matronalis. Colonization was greater in plants grown in the grass matrix than in plants grown alone, and colonization in grass matrix-grown plants continued to increase over the 90-day growth period, whereas colonization leveled off or decreased near the end of the growth period in crucifers grown alone. No arbuscules were observed in crucifer roots at any time, which suggests that AM in these crucifers is nonfunctional. Furthermore, the increase in colonization only in pots with both crucifers and active mycotrophic roots suggests that AM development in crucifer roots is primarily the consequence of progressive root senescence in the crucifer and continued inoculum spread from the mycotrophic plant.
A grid nesting method for large-eddy simulation of planetary boundary-layer flows

A method for performing nested grid calculations with a large-eddy simulation code is described. A common numerical method is used for all meshes, and the grid architecture consists of a single outer or coarse grid, and nested or fine grids, which overlap in some common region. Inter-grid communication matches the velocity, pressure and potential temperature fields in the overlap region. Resolved and sub-grid scale (SGS) turbulent fluxes and kinetic energy on the fine grid are averaged to the coarse grid using a conservation rule equivalent to Germano's identity used to develop dynamic SGS models. Simulations of a slightly convective, strong shear planetary boundary layer were carried out with varying surface-layer resolutions. Grid refinements in the (x, y, z) directions of up to (5, 5, 2) times were employed. Two-way interaction solutions on the coarse and fine meshes are successfully matched in the overlap region on an instantaneous basis, and the turbulent motions on the fine grid blend smoothly into the coarse grid across the grid interface. With surface-layer grid nesting, significant increases in resolved eddy fluxes and variances are found. The energy-scale content of the vertical velocity, and hence vertical turbulent fluxes, appear to be most influenced by increased grid resolution. Vertical velocity spectra show that the dominant scale shifts towards higher wavenumbers (smaller scales) and the magnitude of the peak energy is increased by more than a factor of 3 with finer resolution. Outside of the nested region the average heat and momentum fluxes and spectra are slightly influenced by the fine resolution in the surface layer. From these results we conclude that fine resolution is required to resolve the details of the turbulent motions in the surface layer. At the same time, however, increased resolution in the surface layer does not appreciably alter the ensemble statistics of the resolved and SGS motions outside of the nested region.
Stogdill on Punishment and Punitive Aspects of Leadership: A Response to Sims

Contrary to Sims's claim [1980], Stogdill [1974] does discuss punishment within organizations, although there is no entry under punishment or punitive per se.
The long-term volume of East Europe's foreign trade: An estimate

The transformation process of East European (EE) countries led to the disappearance of the Council for Mutual Economic Assistance, the former Soviet-bloc economic integration scheme, as well as to other changes in the foreign trade sector of those economies. This study seeks to identify the potential long run modifications in the volume of trade of EE countries by using a well-established model employed in the foreign trade literature, the gravity equation. Quantitative results suggest that in the next decades trade between East and West European countries could double from its present level.
Challenges in epidemiological and statistical evaluations of effect modifiers and confounders.

In multiple adjusted regression models, researchers sometimes do not know when the interaction occurs and how to interpret the exposure effect estimate while adjusting for the interaction term, resulting in a misinterpretation of the results; this issue has been raised in previous epidemiologic studies. In addition, when the positions of exposure and outcome are switched in the multiple regression, interpreting covariates is challenging. Here, we present the epidemiological and statistical challenges in evaluating the effect modifier and confounding factor.
Medical error disclosure among pediatricians: choosing carefully what we might say to parents.

Objective To determine whether and how pediatricians would disclose serious medical errors to parents. Design Cross-sectional survey. Setting St Louis, Missouri, and Seattle, Washington. Participants University-affiliated hospital and community pediatricians and pediatric residents. Main Exposure Anonymous 11-item survey administered between July 1, 2003, and March 31, 2004, containing 1 of 2 scenarios (less or more apparent to the child's parent) in which the respondent had caused a serious medical error. Main Outcome Measures Physician's intention to disclose the error to a parent and what information the physician would disclose to the parent about the error. Results The response rate was 56% (205/369). Overall, 53% of all respondents (109) reported that they would definitely disclose the error, and 58% (108) would offer full details about how the error occurred. Twenty-six percent of all respondents (53) would offer an explicit apology, and 50% (103) would discuss detailed plans for preventing future recurrences of the error. Twice as many pediatricians who received the apparent error scenario would disclose the error to a parent (73% [75] vs 33% [34]; P P = .04) compared with the less apparent error scenario. Conclusions This study found marked variation in how pediatricians would disclose a serious medical error and revealed that they may be more willing to do so when the error is more apparent to the family. Further research on the impact of professional guidelines and innovative educational interventions is warranted to help improve the quality of error disclosure communication in pediatric settings.
Sequence Determinants of GLUT1-mediated Accelerated-exchange Transport ANALYSIS BY HOMOLOGY-SCANNING MUTAGENESIS

The class 1 equilibrative glucose transporters GLUT1 and GLUT4 are structurally similar but catalyze distinct modes of transport. GLUT1 exhibits trans-acceleration, in which the presence of intracellular sugar stimulates the rate of unidirectional sugar uptake. GLUT4-mediated uptake is unaffected by intracellular sugar. Using homology-scanning mutagenesis in which domains of GLUT1 are substituted with equivalent domains from GLUT4 and vice versa, we show that GLUT1 transmembrane domain 6 is both necessary and sufficient for trans-acceleration. This region is not directly involved in GLUT1 binding of substrate or inhibitors. Rather, transmembrane domain 6 is part of two putative scaffold domains, which coordinate membrane-spanning amphipathic helices that form the sugar translocation pore. We propose that GLUT1 transmembrane domain 6 restrains import when intracellular sugar is absent by slowing transport-associated conformational changes.
The mobA gene is required for assimilatory and respiratory nitrate reduction but not xanthine dehydrogenase activity in Pseudomonas aeruginosa.

The requirement for the mobA gene in key assimilatory and respiratory nitrogen metabolism of Pseudomonas aeruginosa PAO1 was investigated by mutational analysis of PA3030 (mobA; MoCo guanylating enzyme), PA1779 (nasA; assimilatory nitrate reductase), and PA3875 (narG; respiratory nitrate reductase). The mobA mutant was deficient in both assimilatory and respiratory nitrate reductase activities, whereas xanthine dehydrogenase activity remained unaffected. Thus, P. aeruginosa requires both the molybdopterin (MPT) and molybdopterin guanine dinucleotide (MGD) forms of the molybdenum cofactor for a complete spectrum of nitrogen metabolism, and one form cannot substitute for the other. Regulation studies using a Φ(PA3030-lacZGm) reporter strain suggest that expression of mobA is not influenced by the type of nitrogen source or by anaerobiosis, whereas assimilatory nitrate reductase activity was detected only in the presence of nitrate.
Paleomagnetic data from the Redding section of the eastern Klamath belt, northern California

A paleomagnetic analysis of units of Devonian to Triassic age within the Redding section of the eastern Klamath Mountains indicates clockwise rotation of 83°–116° with respect to stable North America. In the kinematic model presented here, shear zones within the Franciscan Complex, with separation antithetic to the San Andreas, are used to effect this rotation.
Microshutters arrays for the JWST near-infrared spectrometer

The Near Infrared Spectrograph (NIRSpec) for the James Webb Space Telescope (JWST) is a multi-object spectrograph operating in the 0.6-5.0 μm spectral range. One of the primary scientific objectives of this instrument is to measure the number and density evolution of galaxies following the epoch of initial formation. NIRSpec is designed to allow simultaneous observation of a large number of sources, vastly increasing the capability of JWST to carry out its objectives. A critical element of the instrument is the programmable field selector, the Microshutter Array. The system consists of four 175 x 384 close packed arrays of individually operable shutters, each element subtending 0.2” x 0.4”on the sky. This device allows simultaneous selection of over 200 candidates for study over the 3.6’ x 3.6’ field of the NIRSpec, dramatically increasing its efficiency for a wide range of investigations. Here, we describe the development, production, and test of this critical element of the NIRSpec.
Advances in Screening, Diagnosis, and Treatment of Breast Cancer

Breast cancer is the most common cancer in women in the United States; this year, approximately 215,900 new cases will be diagnosed. Mammography remains the cornerstone of screening, with technologies such as ultrasonography and magnetic resonance imaging having an increasingly defined role. Improved risk assessment and prevention strategies have been implemented, and current research in these areas includes better identification of patients at risk, the use of aromatase inhibitors and other agents to reduce risk, and the use of surrogate markers. Breast cancer staging has been optimized recently; also, local management of breast cancer, adjuvant systemic therapies, and treatment of patients with advanced disease have been evolving. Advances in screening, diagnosis, and treatment of breast cancer continue to influence our approach to patients with this disease. Many improvements have been made as well in supportive care, including increased tolerability of therapy and notable amelioration of disease symptoms.
Teaching Thermodynamics via Analysis of the West Point Power Plant

Thermodynamic analyses can be performed based on energy-gross and exergy-net quantities. These topics are discussed in the context of the United States Military Academy at West Point's power plant and the project that students work on as a part of their course requirements for three courses. A systematic, detailed, and comprehensive methodology is presented based on recent experiences that can be a standard for similar academic instruction of thermodynamic concepts and power plants. A well-defined case study for the classroom will yield more effective learning of and inspire a greater appreciation for critical power technologies.
Isolated Parotid Acinar Cells from Patients With Cystic Fibrosis. Functional Characterization

Studies of the homeostasis and secretory function of isolated parotid acinar cells from patients with cystic fibrosis were conducted. It was demonstrated that the transmembrane fluxes of Na and the muscarinic cholinergic receptor stimulus-secretion coupling were depressed, while the stimulus-secretion coupling of the beta-adrenergic receptor was hyper-reactive.
Representing the Discipline: The Operations of Architecture's Discursive Imagery

This article examines the lineage of the discursive image and its capacity to represent the discipline of architecture. Emanating historically from Diderot and d’Alembert’s Encyclopedie, and its desire to make cultural production intelligible, the paper considers this practice of representing the discipline through the techniques it deploys and considers the consequences, both representationally and with respect to our understanding of disciplinary knowledge. The author questions whether it is more appropriate to represent architectural techniques or the situated practices of the architect. Given that disciplinary discourse shapes our representations, while simultaneously exceeding the limits of representation, why is there a profusion of architectural images whose sole aspiration is to communicate the techniques of their own making?
Establishing public accountability, speaking truth to power and inducing political will for disaster risk reduction: ‘Ocho Rios + 25’

The problem is that disaster risk reduction (DRR) is still more a zone of political darkness than of light. Therefore, the purpose of our contribution to this theme issue is to illuminate at least some of that zone of political darkness and to suggest a more proactive, but for many career professionals a personally problematic, way forward for DRR. The career problematic derives from the fact that the way forward would involve moving from applauding the emergence of elected and/or appointed champions (from mayors to cabinet ministers to presidents/prime ministers) for action to raising the political costs of inaction by leaders not otherwise disposed. The essential element of this way forward would be greatly enhanced public accountability. We will draw preliminary accountability lessons from the Haiti earthquake catastrophe and the Chile earthquake disaster 2010 events towards the conclusion of this paper as we outline a possible future paradigm.
Photomask/resist capability—An approach to assessment

Abstract The current activity in LSI and high density semiconductor memory development has increased emphasis on the need for the reduction of process-induced defects. An appreciable number of these defects is associated with photofabrication steps due to photomask and/or photoresist variations. In order to minimize defects caused by these steps, it is necessary to determine the type and density of photomask/resist faults that result in any given device defect. The evaluation techniques used should not require highly sophisticated and expensive equipment that would prevent their use in a normal production environment. With these objectives in mind, a test pattern has been designed to evaluate both photomask and photoresist process variables. Test procedures using typical production processes have been developed for this pattern to evaluate such parameters as average alignment accuracy, mask image distortion, etching control, and mask durability. The test pattern and associated evaluation test procedures are described. The more significant aspects are discussed and some illustrative results are presented where appropriate.
The stages of amelogenesis as observed in molar teeth of young rats

The basal lamina that is seen between the preameloblasts and the odontoblasts is removed before the deposition of mineral in the developing molar tooth of the rat. No dentino-enamel membrane is to be seen between the enamel and dentine. The formation of enamel occurs in such a manner as to indicate that a mineralization front exists. Tomes' processes quickly develop after the initiation of amelogenesis. They extend from the level of the terminal bars, and have been divided into proximal and distal parts. The proximal part extends as far as the mineralization front and is surrounded by stippled material. The distal part dips into the enamel. The processes contain: coated vesicles, multivesiculated bodies, dense granules, large granules, microtubules, filaments, and agranular endoplasmic reticulum. Microvilli project from the sides of the Tomes' processes, into the stippled material. The presence of coated vesicles and microvilli are interpreted as evidence that absorptive activity also occurs at the distal end of “secretory” ameloblasts. Correlation of electron and light micrographs clarifies the nature of “pre-enamel.”
Problem-Solving Appraisal and the Prediction of Depression during Pregnancy and in the Postpartum Period.

Based on the presumed mood-regulatory properties of the problem orientation component delineated in the social problem-solving model, a positive problem orientation was predicted to influence ongoing levels of positive and negative affect during pregnancy. Higher levels of positive affect and lower levels of negative affect would then in turn predict depression during pregnancy and in the postpartum period. This hypothesis was tested in 100 women. Path analyses supported the predicted relation of the problem orientation components to trait affectivity, and indirectly to peripartum and postpartum depression. Trait negative and positive affectivity was also associated with peripartum depression, and indirectly with postpartum depression, as expected. Implications for the integrated social problem-solving model are discussed. Recommendations for assessment and counseling interventions with expectant women are offered.
Idealized two-dimensional detonation waves in gaseous mixtures

Abstract The major role in propagation of detonation is played by the collision processes between wave intersections. Our study deals with the dynamic behavior of this phenomenon in the gaseous phase. The most informative records of this phenomenon are those showing cellular traces inscribed by the detonation wave on the tube wall. Such records not only reveal the sizes and shapes of the individual cells and their dependence on the initial conditions, but also allow insight into the processes that take place within these cells. Using a graphical technique for oblique discontinuities, we did a systematic analysis for a range of parameters to determine how they affect the dynamic behavior of the process. We found that the most significant parameter of the intersection is the incident angle θ. The orientation of θ changes during a cycle, but its magnitude suffers almost no change. Thus, once the detonation wave is established, the geometry of the cell stays constant. Fluctuations in pressure and velocity also remain invariant. The decay factor and the two extreme values between which the fluctuations occur depend only on one parameter, θ. Good agreement with experimental results leads us to conclude that instabilities which are considered to be inherent to any detonation processes are quite stable and invariant in their own small scale.
Ornithine accumulation and metabolism in rat lens

Abstract The non-protein amino acid ornithine is readily accumulated into rat lenses cultured in TC-199 bicarbonate medium. This accumulation, measured by the lens water/lens medium ratios of radiolabeled ornithine, appears to be the result of an apparent energy-dependent basic amino acid transport system. Moreover, competition studies suggest that increased levels of ornithine can depress the concomitant lenticular accumulation of arginine and lysine. Examination of the trichloroacetic acid protein precipitates of these cultured lenses indicates that the radiolabel from ornithine can also be incorporated into lens proteins as proline. This results from the conversion by ornithine aminotransferase (EC 2. 6. 1. 13) of radiolabeled ornithine to delta1-pyrroline-5-carboxylic acid (P5C), which is subsequently converted to proline by P5C reductase (EC 1. 5. 1. 2). This incorporation of radiolabel into cultured lens proteins is reduced upon addition of either 1 m m proline or P5C to the culture medium or inhibited by the addition of the protein synthesis inhibitor, puromycin.
A fetus with sirenomelia, omphalocele, and meningomyelocele, but normal kidneys

Sirenomelia, which has been reported for more than 450 years, is the most se- vere form of caudal dysplasia. This disorder is clas- sically associated with agenesis or severe dyspla- sia of the urinary tract. A 27-year-old gravida 3 para 0020 presented at 19 weeks' gestation with monoamniotic twins, one normal and one with sirenomelia. The pregnancy miscarried following invasive diagnostic testing. Autopsy confirmed the findings of sirenomelia, meningomyelocele, omphalocele, persistent clo- aca, and two normal kidneys. The abnormalities accompanying sirenomelia appear as a spectrum. The pathogenic theories of sirenomelia are reviewed in light of this case with normal kidneys. o 1994 ~~iey-t~ss, Inc. Sirenomelia, so named for the Greco-Roman mythi- cal siren with the tail of a fish and human upper body, has intrigued investigators for hundreds of years. Two reviews of many of the cases in the literature have been compiled. The first, by Kampmeier ('27), covered 79 reports from 1542-1927. The second (Stocker, '87) com- piled cases from 1928-1982, and reported on 33 cases from the Armed Forces Institute of Pathology. Varia- tions of the "fused' lower extremities are described, as are the accompanying anomalies. Every case in both these reviews had severe renal dysplasia or agenesis. However, two recent cases of children with sirenomelia and normally functioning renal tissue have been re- ported (Savader et al., '89; Murphy et al., '92; Clarke et al., '93). These children had more lateralization of limb tissue than most in the literature. Our patient demonstrated severe sirenomelia, mul- tiple other anomalies, and the presence of normal kid- neys. The presence of these normal kidneys forces a reappraisal of previous hypotheses regarding the pathogenesis of this disorder. CASE REPORT
Surveillance of hazardous substances releases due to system interruptions, 2002

The Hazardous Substances Emergency Events Surveillance (HSEES) system collected information on 9014 acute hazardous substance releases in 15 participating states in 2002. There were 3749 fixed-facility manufacturing events, of which 2100 involved "interruptions" to normal processing and 1649 "comparisons" that did not involve interruption. Equipment failure (69%) or intentional acts (20%) were the main root factor. Many events occurred in October and November in three states (Texas, Louisiana, and New Jersey), in three manufacturing industries (industrial and miscellaneous chemicals; petroleum refining; and plastics, synthetics, and resins). In interruption events, the substance categories most often released were mixtures, other inorganic substances, and volatile organic compounds and those most often causing injury were acids, chlorine, bases, and ammonia. Comparison events resulted in more acutely injured persons (408 versus 59) and more evacuees (11,318 versus 335) than interruption events and therefore may receive more public health attention. Because of the large number of interruption events, targeted prevention activities, including management of change procedures, lessons-learned implementation, process hazards analysis, and appropriate protection for workers could be economically advantageous and improve environmental quality. Efforts should focus on the identified areas of greater occurrence. The relationship of weather and equipment failure with interruption events needs further investigation.
Nitrogen Dynamics in Humic Fractions under Alternative Straw Management in Temperate Rice

Crop residue management practices can affect N immobilization and stabilization processes important to efficient utilization of N from fertilizers, crop residues, and soil organic matter (SOM). A 2-yr, 15 N-labeling field study was conducted to examine the effects of winter-fallow flooding (vs. unflooded) and straw residue incorporation (vs. burning) on the rates of sequestration and stability of specific SOM pools critical in sustaining N fertility in rice (Oryza sativa L.). Five SOM fractions were examined from soil samples obtained over Years 4 to 6 of a field trial: light fraction (LF), mobile humic acid (MHA), mobile fulvic acid (MFA), metal-associated humic acid (MAHA), and alkali-insoluble humics (HUM). After 4 yr of straw management treatments, soil incorporation of straw increased MHA and LF C and N compared with burned straw. Immobilization of N fertilizer peaked in all SOM fractions after one growing season (120 d) and was greatest in the MHA fraction over the 2-yr 15 N study. Nitrogen fertilizer sequestration in MHA and LF was greater with straw incorporation compared with burned. Turnover of immobilized 15 N-fertilizer in the stable organic components was fastest in the labile MHA and MFA fractions (7- to 9-yr half-life) compared with the half-lives of the moderately resistant MAHA fraction (53 yr) and most stable HUM fraction (153 yr). While the MAHA and HUM fractions played a significant role in N fertilizer immobilization and turnover, the MHA and LF fractions represented the primary active sink and source of sequestered N affecting both short- and long-term soil fertility.
Testing trade‐off and pecking order models of capital structure: does legal system matter?

Purpose – This paper aims to examine the link between financing patterns, information asymmetry and legal traditions in 37 countries during the 1990‐2004 period.Design/methodology/approach – The analysis is based on three theories: the trade‐off theory, pecking order hypothesis and market timing hypothesis. The authors test the predictions of these theories/hypotheses using regression analysis. The econometric method used is panel data with firm and country fixed effects. The authors develop a modified pecking order model which controls for short‐ and long‐term debt level changes and simultaneously test the predictions of all theories.Findings – Consistent with studies for US firms, the results show that firms across all countries adjust toward the target leverage, but with significantly different rate. The long‐term debt contribution in the rate of adjustment is 64 percent in common law countries and 51 percent in civil law countries. The ability of the model to explain changes in leverage ratios is high...
Embryonic stem cells and potency to induce transplantation tolerance.

In the past 40 years, many protocols have been extensively studied for the induction of sustainable transplantation tolerance which might lead to protection of allografts from immunological injury in the clinical setting. Despite the enormous success in rodents, there is still no established protocol available yet for widespread clinical trials. Whilst clonal deletion, clonal anergy and suppression, now coined regulation, have been elucidated as the key immunological elements of tolerance, a better understanding of these mechanisms has so far done little to improve on the survival of organ transplants in humans. Haematopoietic chimaerism, as previously described by Medawar and colleagues [1], remains the most robust tool for tolerance induction. Unfortunately, bone marrow or haematopoietic stem cell transplantation for patients awaiting solid organ transplantation remains a high risk therapy, due to the dangers of graft-versus-host disease. Most recent data, however, indicate the potential of embryonic st...
Expectations of millennial nurse graduates transitioning into practice.

Aims Identified as Millennials, nurses born after 1980 are anticipated to redefine the employer-employee relationship as one based on the employee's wants and needs. The purpose of this study is to portray the expectations of Millennial student nurses immediately before graduation. Understanding these expectations may provide insight for leaders who are responsible for crafting a successful transition experience. Successful transition and decreased turnover are important elements of cost management for the nursing enterprise. Methods/subjects A qualitative descriptive design was used to collect data from 14 students enrolled in a traditional BSN academic nursing program approximately 2 months prior to graduation. Upon completion of private, confidential semistructured interviews, data were transcribed, coded, and analyzed. Demographic data were compiled and interview data summarized according to identified themes. Results/conclusions Three overarching themes emerged: the expectation that transition would be stressful, the expectation that there would be a safety net of support, and the expectation to be valued and respected as a professional. Revealing was the expectation of supportive relationships and a collaborative approach to patient care. Failure to meet those expectations may result in turnover as Millennials seek opportunities that meet their expectations.
Rigidity, Locally Symmetric Varieties, and the Grothendieck-Katz Conjecture

Using Margulis's results on lattices in semisimple Lie groups, we prove the Grothendieck-Katz p-curvature conjecture for many locally symmetric varieties, including Hilbert-Blumenthal modular varieties and the moduli space of abelian varieties when g > 1.
THE COMPLEXITY OF THE FLUORESCENCE OF CHLORELLA PYRENOIDOSA

— The complexity of the room-temperature emission spectrum of Chlorella was investigated by a matrix analysis method. This approach revealed the presence of two independently fluorescent components in the short-wave region of the spectrum. These components, maximal at about 687 and 695 nm, appeared to correspond to the fluorescence of the bulk pigments of PS II and PS I respectively. The analysis was insensitive to the individual species within the photosystems. As such, other minor fluorescent species, usually observed at low temperatures, which presumably correspond to fluorescence from the trapping centres, did not appreciably complicate the analysis. The absorption spectra of the two photosystems were calculated from the fluorescence data. The results were similar to those that have been obtained by other workers from oxygen evolution and DCMU poisoning data but differed from those obtained by computer analysis of the absorption spectrum. Addition of reduced DCPIP was observed to reverse the increase in fluorescence yield and changes in the spectral distribution of emission taking place on poisoning the algae. The correlation between this and the catalysis of photophos-phorylation in aged or poisoned chloroplasts was noted. This correlation was tentatively interpreted as evidence for a direct interaction between the donor system and the photochemical apparatus associated with PS II, rather than with a member of the electron transport chain as is normally assumed.
Thermally assisted atom transfer on surfaces

The low-temperature rates for site-to-site transfer of single atoms and molecules adsorbed on surfaces have been determined in recent scanning tunneling microscopy (STM) studies within the temperature regime where the dominant transfer mechanism changes from mostly activated transmission over to thermally assisted tunneling through the intersite (transition-state) barrier as the temperature is reduced. A model that has provided useful conceptual and quantitative insights into thermally assisted field emission of electrons is used here as the basis for a theory of site-to-site atom transfer in this temperature range where proper account of atomic tunneling and quantum reflection, for energies below and above the transition state barrier, is required. The predicted transfer rates, which are very sensitive to barrier shape as well as height, agree well with those observed in the STM studies of Co and Cu on surfaces in the interesting transition range which is relevant in the atom-by-atom fabrication of thermally stable surface nanostructures.
Asymmetric Synthesis of an MMP-3 Inhibitor Incorporating a 2-Alkyl Succinate Motif

An efficient and practical synthesis is presented of the pharmaceutically active MMP-3 inhibitor UK-370,106 (1) via an olefination/catalytic asymmetric hydrogenation sequence. Commercially available 5-bromo-2-iodotoluene was converted in two steps to the biarylpropanal equivalent (11), which was reacted with the phosphonosuccinate (10) to selectively afford the trans-β-substituted itaconate (12). Catalytic asymmetric hydrogenation of the itaconate (12) was achieved in good conversion and with 86−96% enantiomeric excess with a range of phosphine-modified rhodium and ruthenium cationic complexes. The resulting enantiomerically enriched 2-alkyl succinate (2) was elaborated to the desired drug substance (1) in two steps. The synthesis benefits from several crystalline intermediates, allowing control of process impurities, and can be operated safely within parameters readily achievable on scale. Investigations into the polymorphic forms of (1) have shown that the compound crystallizes in planar sheets, based o...