julilili42/papers huggingface dataset:
Human capital formation under product market uncertainty
2002-08-01

The paper presents a microeconomic model of human capital formation in a local labour market, with heterogeneous workers and firms, when product markets are characterised by price uncertainty. We analyse a setting where firms are hit by demand shocks determining either a good or a bad state. Firms produce for a competitive output market with differing technologies, thus requiring diverse skills. In anticipation of firm behaviour, workers choose between specialising into a certain type of skills, and accumulating general skills. We thus look at the endogenous determination of the level of both horizontally differentiated and general human capital. Our findings suggest that, with equal probability on each shock scenario, a higher output price (booming industry) will raise the return to both general and specific human capital. Labour market size (skill diversification) however, has a differential impact. As the market is enlarged, workers are likely to form more general human capital at the expense of directly productive human capital. We then investigate a specific shock probability structure and find that under more symmetric shocks the incentive to invest in either kind of human capital is weaker. Interpreting the symmetry of shocks as an indicator of the degree of regional industrial specialisation, we infer that, everything else being constant, specialised regions will be less flexible in their response to structural change and also less productive. Bearing in mind the importance of human capital for economic growth, adverse effects on the growth rate of specialised regions may follow.
Pauli principle and nucleon$ndash$nucleon final state interaction
2002-08-01

Meson production processes with more than two identical nucleons in the exit channel are expected to be strongly Pauli blocked close to threshold. However, it is shown that this Pauli suppression becomes ineffective due to the final state interaction between the outgoing nucleons.
Microelectromagnets for trapping and manipulating ultracold atomic quantum gases
2002-08-05

We describe the production and characterization of microelectromagnets made for trapping and manipulating atomic ensembles. The devices consist of seven fabricated parallel copper conductors 3 μm thick, 25 mm long, with widths ranging from 3 to 30 μm, and are produced by electroplating a sapphire substrate. Maximum current densities in the wires up to 6.5×106 A cm−2 are achieved in continuous mode operation. The device operates successfully at a base pressure of 10−11 mbar. The microstructures permit the realization of a variety of magnetic field configurations and, hence, provide enormous flexibility for controlling the motion and the shape of Bose–Einstein condensates.
Combined therapy of cerebral arteriovenous malformations: histological differences between a non-adhesive liquid embolic agent and n-butyl 2-cyanoacrylate (NBCA).
2002-08-06

Onyx promises to be an embolic agent well suitable for subsequent neurosurgical resection. Further studies considering various intervals of time between embolization and resection as well as histopathological and electron microscopical examinations are necessary for evaluation of our first experience with this new embolization agent.
Structure of mistletoe lectin I fromViscum albumin complex with galactose, lactose and adenin
2002-08-06

Human neutrophil elastase (HNE) has been shown to contribute to the pathogenesis of destructive disease, such as acute respiratory distress syndrome, ischemia-reperfusion injury and multiple organ failure.Watersoluble HNE inhibitor that can be easily administrated intravenously would be desired for the treatment of such acute disorders.AE-3763 has potent in vivo activity (ED50=0.42mg/kg/hr on lung hemorrhage induced by HNE in hamsters) and high solubility (1g/ml H2O).We have determined the crystal structure of porcine pancreatic elastase complexed with AE-3763 at 1.55 Å resolution.A final complex model had crystallographic R-factor less than 0.19.A clear electron density was observed for the inhibitor molecule in the active site.In this presentation, we will describe the X-ray crystallographic study of the interaction of AE-3763 with the active site of PPE.AE-3763:S-[2-(3carboxymethyl-2-oxo-1-imidazolidinyl)-acetyl]-L-valyl-N-(3,3,3,-trifluoro-1isopropyl)-2-oxopropyl-L-prolinamide
Teaching modulated structures - a project-based approach
2002-08-06

The importance attributed to modulated structures in recent years is reflected by a rapidly increasing number of publications.Modulated structures can be considered as crystals of a basic structure with a periodic distortion.The distortion can be either displacive (variable atomic positions) and/or occupational (variable composition) in nature.In either case this variability reveals itself by the existence of so-called satellite reflections, often weaker than the main reflections of the underlying basic structure.The introduction of area detectors has enabled structural scientists to recognize these characteristic diffraction patterns more easily and with JANA2000 a software tool is available that allows to handle the resulting intensity data according to the specific requirements of superspace refinement.KNbOB2O5, a recent problem from our Application Lab, provides an excellent example for an understandable modulated structure, which, at the same time, fully demonstrates how to proceed with indexing, data processing, structure solution, and refinement.The underlying concepts of the superspace approach will be presented and discussed step by step via our sample structure.We believe that this type of project-based learning is a valuable addition to the traditional textbook method and will gain more significance in the future as the subjects of crystallographic teaching become more and more complex.
Investigation of magnetism in PrMn2−xTxGe2(T=Fe and Co) by neutron diffraction
2002-08-06

The importance attributed to modulated structures in recent years is reflected by a rapidly increasing number of publications.Modulated structures can be considered as crystals of a basic structure with a periodic distortion.The distortion can be either displacive (variable atomic positions) and/or occupational (variable composition) in nature.In either case this variability reveals itself by the existence of so-called satellite reflections, often weaker than the main reflections of the underlying basic structure.The introduction of area detectors has enabled structural scientists to recognize these characteristic diffraction patterns more easily and with JANA2000 a software tool is available that allows to handle the resulting intensity data according to the specific requirements of superspace refinement.KNbOB2O5, a recent problem from our Application Lab, provides an excellent example for an understandable modulated structure, which, at the same time, fully demonstrates how to proceed with indexing, data processing, structure solution, and refinement.The underlying concepts of the superspace approach will be presented and discussed step by step via our sample structure.We believe that this type of project-based learning is a valuable addition to the traditional textbook method and will gain more significance in the future as the subjects of crystallographic teaching become more and more complex.
Iron transport and signaling in Escherichia coli
2002-08-14

Bacteria solve the iron supply problem caused by the insolubility of Fe 3+ by synthesizing iron‐complexing compounds, called siderophores, and by using iron sources of their hosts, such as heme and iron bound to transferrin and lactoferrin. Escherichia coli , as an example of Gram‐negative bacteria, forms sophisticated Fe 3+ –siderophore and heme transport systems across the outer membrane. The crystal structures of three outer membrane transport proteins now allow insights into energy‐coupled transport mechanisms. These involve large long‐range structural transitions in the transport proteins in response to substrate binding, including substrate gating. Energy is provided by the proton motive force of the cytoplasmic membrane through the activity of a protein complex that is inserted in the cytoplasmic membrane and that contacts the outer membrane transporters. Certain transport proteins also function in siderophore‐mediated signaling cascades that start at the cell surface and flow to the cytoplasm to initiate transcription of genes encoding proteins for transport and siderophore biosynthesis.
A comparative review of extracorporeal shock wave generation
2002-08-14

Summary Shock waves are specific sound waves produced by shock‐wave generators; the generators currently available have different physical properties and represent different technical solutions. The measurement of shock‐wave pressure is necessary in laboratory settings to define the physical characteristics of a given shock‐wave source. Under clinical conditions other variables, e.g. the stone‐free rate or the percentage of complications, are used to describe the efficacy and safety of a lithotripter.
High Level Expression of Chorismate Pyruvate-Lyase (UbiC) and HMG-CoA Reductase in Hairy Root Cultures of Lithospermum erythrorhizon
2002-08-15

Shikonin, a red naphthoquinone pigment, is produced by cell cultures of Lithospermum erythrorhizon (Boraginaceae). It is biosynthetically derived from two key precursors, 4-hydroxybenzoate (4HB) and geranyldiphosphate (GPP). The bacterial ubiC gene, encoding chorismate pyruvate-lyase (CPL) which converts chorismate to 4-hydroxybenzoate, was expressed in L. erythrorhizon under the control of the strong (ocs)(3)mas-promoter. This introduced an efficient biosynthetic pathway to 4HB, i.e. a one-step reaction from chorismate, in addition to the endogeneous multi-step phenylpropanoid pathway. Feeding experiments with [1,7-(13)C(2)]shikimic acid showed that in the most active transgenic line, 73% of 4HB was synthesized via the genetically introduced pathway. However, there was no correlation between CPL activity and 4HB glucoside or shikonin accumulation in the transgenic lines. HMG-CoA reductase (HMGR) is involved in the biosynthesis of GPP in L. erythrorhizon. Two forms of HMGR1 of Arabidopsis thaliana were expressed in Lithospermum under control of the (ocs)(3)mas promoter. Only moderate increases in enzyme activity were obtained with the complete enzyme, but high activity was achieved using the soluble cytosolic domain of HMGR1. Shikonin accumulation remained unchanged even upon high expression of soluble HMGR.
Probing the Stereointegrity of Tröger's Base—A Dynamic Electrokinetic Chromatographic Study
2002-08-16

Under acidic conditions the enantiomers of Tröger's base 1 (2,8-dimethyl-6 H,12 H-5,11-methanodibenzo[b,f][1,5]diazozine) are subject to enantiomerization. During enantioselective dynamic electrokinetic chromatography using 10 mM hydroxypropyl-beta-cyclodextrin as the chiral mobile phase additive in 50 mM tris/phosphate buffer at pH 2.2, enantiomerization of Tröger's base gives rise to characteristic elution profiles featuring plateau formation and peak broadening. Introduction of a permanent positive charge attributed to quaternization in the monobenzylated derivative of Tröger's base 2 (5-benzyl-2,8-dimethyl-6 H,12 H-5,11-methanodibenzo[b,f][1,5]diazozinium bromide) decreases the enantiomerization barrier significantly. To determine the rate constants of enantiomerization the experimental chromatograms were evaluated by a direct calculation method and by using the computer simulation program ChromWin. From temperature-dependent measurements the Eyring activation parameters for 1 and 2 were determined: 1: DeltaG( not equal ) (298 K)=100.9+/-0.5 kJ mol(-1), DeltaH( not equal )=89.5+/-2.0 kJ mol(-1), DeltaS( not equal )=-42+/-10 J K(-1) mol(-1); 2: DeltaG( not equal ) (298 K)=90.2+/-0.5 kJ mol(-1), DeltaH( not equal )=91.4+/-2.0 kJ mol(-1), DeltaS( not equal )=9.8+/-10 J K(-1) mol(-1).
ULTRA Loaded Resins Based on the Cross-Linking of Linear Poly(ethylene imine). Improving the Atom Economy of Polymer-Supported Chemistry J.R. gratefully acknowledges support from Prof. G. Jung and Prof. M. E. Maier, TÃ¼bingen, the Strukturfonds of the University of TÃ¼bingen, DFG project âReactive Intermediates in Polymeric Gelsâ (Ra 895/2), the Fonds der Chemischen Industrie, and from the DFG graduate college âChemistry in Interphasesâ (project 6, Rademann), from which M.B. receives a stipend. We are grateful to Rainer Fischer, Elke Gesele, Dr. Klaus Eichele, and Nicole Sessler for analytical and technical support. We thank Personal Chemistry GmbH, Constance, Germany, for lending us a microwave synthesizer.
2002-08-16

ULTRA resins (see picture), useful for making polymer reagents, heterocycles, and peptides, were prepared by thermodynamically controlled cross-linking of linear poly(ethylene imine)s with a loading of up to 15 mmol g−1. During characterization, the secondary amines in the resin backbone of the novel carriers were found to be very accessible to chemical modification.
Gliomatosis cerebri: Molecular pathology and clinical course
2002-08-19

Abstract Gliomatosis cerebri is a rare, diffusely growing neuroepithelial tumor characterized by extensive brain infiltration involving more than two cerebral lobes. Among 13 patients with gliomatosis cerebri (median age, 46 years), biopsies showed features of diffuse astrocytoma (n = 4), oligoastrocytoma (n = 1), anaplastic astrocytoma (n = 5), anaplastic oligoastrocytoma (n = 1), or glioblastoma (n = 2). Molecular genetic investigation showed TP53 mutations in three of seven tumors and both PTEN mutation and epidermal growth factor receptor overexpression in one tumor. Amplification of CDK4 or MDM2 or homozygous deletion of CDKN2A was not detected. Three of 10 patients receiving radiotherapy showed a partial response (one patient) or had stable disease (two patients) lasting for more than 1 year. Four of six patients treated with procarbazine, carmustine, vincristine chemotherapy demonstrated partial remission (one patient), minor response (two patients), or stable disease (one patient). Median survival time from diagnosis was 14 months (range, 4–91+ months). Infratentorial involvement was associated with shorter survival. We conclude that (1) the molecular genetic alterations in gliomatosis cerebri resemble those in diffuse astrocytomas; (2) the prognosis of gliomatosis cerebri is variable but for at least 50% of patients as poor as for glioblastoma; and (3) some patients respond to radiotherapy and/or procarbazine, carmustine, vincristine chemotherapy.
Modulation of growth and radiochemosensitivity of human malignant glioma cells by acidosis
2002-08-19

Abstract BACKGROUND Glioblastoma commonly is characterized by hypoxia and acidosis and the histologic features of tissue necrosis and neovascularization. Current approaches of adjuvant radiochemotherapy for patients with glioblastoma have only a modest impact on the natural course of this disease. METHODS The authors examined the effects of acidosis on growth and response to irradiation and chemotherapy in cultured human malignant glioma cells. RESULTS The authors found that mild acidosis (pH 7.0) inhibited the growth of cell lines that retained wild type p53 activity but did not inhibit the growth of cell lines that were devoid of p53 function. Transfer of a dominant‐negative p53 gene into p53 wild type cells failed to override the acidosis‐conferred growth arrest, suggesting that loss of p53 activity per se does not mediate escape from acidosis‐induced growth inhibition. Moderate acidosis (pH 6.6) inhibited the growth of all cell lines. Acidosis‐mediated growth arrest was not associated with a specific type of cell cycle arrest, e.g., in G0/G1 or G2/M phase. Acidosis did not result in consistent changes in radiosensitivity; however, it enhanced the cytotoxic effects of lomustine but conferred protection from topotecan, vincristine, teniposide, and cisplatin cytotoxicity. Lomustine exhibited enhanced stability at low pH, providing a putative mechanism for the enhanced cytotoxic effects of lomustine in acidotic conditions. Decreased sensitivity to the other drugs did not result from altered multidrug resistance drug transport activity. CONCLUSIONS Taken together, the current results suggest that tissue acidosis may be an important determinant of glioma cell responses to adjuvant radiochemotherapy. The superior activity of nitrosoureas, such as lomustine, compared with other agents in patients with glioblastoma may result in part from prolonged drug stability in an acidotic microenvironment. Cancer 2002;95:1113–9. © 2002 American Cancer Society. DOI 10.1002/cncr.10767
Electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry to reveal the substrate specificity of the peptidyl‐cysteine decarboxylase EpiD
2002-08-19

Abstract The microbial flavoenzyme EpiD catalyzes the oxidative decarboxylation of peptidyl‐cysteines to peptidyl‐aminoenethiols. These unusual C‐terminally modified peptides are intermediates in the biosynthesis of the tetracyclic peptide antibiotic epidermin, which belongs to the lantibiotics family. The peptide SFNSYCC represents the C‐terminal partial sequence of the natural precursor peptide EpiA. EpiA is posttranslationally modified to form finally the lantibiotic epidermin. The substrate specificity of EpiD was investigated using high‐resolution mass spectrometry and the heptapeptide library SFNS X CC. The enzymatic conversion of particular peptides can be observed by a mass loss of m/z 46. In contrast to the previously used triple quadrupole instrument, electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI‐FTICR‐MS) was able to resolve and detect all precursor and converted peptides with identical nominal masses in a single measurement, avoiding the necessity to investigate single peptides. Furthermore, a new substrate SFNS C CC of the enzyme EpiD was detected within the reaction mixture. Copyright © 2002 John Wiley &amp; Sons, Ltd.
Prediction of personality disorder traits by psychosis proneness scales in a German sample of young adults
2002-08-19

Abstract Prior research has focused on schizophrenia‐spectrum disorder traits in psychosis‐prone subjects. The whole range of personality disorders were only explored in patient samples and with the relatives of patients. In light of this situation, the predictive value of Physical Anhedonia (PhA), Perceptual Aberration (PER), and Magical Ideation (MI) for personality disorder traits were examined dimensionally and categorically in a non‐patient sample. We selected a non‐student sample ( n = 404) and focused on two risk groups (PhA: n = 14; combined PER/MI: n = 36), and a control group ( n = 19) using the SCID II to assess personality disorders at a time period two years later. MI explained most of the variance in clinically relevant schizotypal personality disorder symptoms, while PER and PhA dimensionally were associated with the number of diagnostic criteria met for other personality disorders. While both risk groups exceeded the control group in clinically relevant borderline traits, only the PER/MI‐individuals differed in fulfilling more criteria for schizotypal personality disorder. © 2002 Wiley Periodicals, Inc. J Clin Psychol 58: 1091–1101, 2002.
Erratum: Expectation values of four-quark operators in pions [Phys. Rev. D65,074015 (2002)]
2002-08-19

The values of four-quark operators averaged over pions are expressed through those averaged over vacuum.The specific values are obtained in the framework of the factorization assumption.For the condensates of the light quarks of the same flavour qΓq qΓq the scalar condensate is shown to be an order of magnitude larger than the other ones.The condensates containing the strange quarks qqss appear to be only about twice smaller than those of the light quarks.The degeneracy of the ground state in the Nambu-Jona-Lasinio model is shown explicitly.
Protein Secretion in Plants: from the trans‐Golgi Network to the Outer Space
2002-08-20

Functional analysis of exocytosis in yeast and animal cells has led to the identification of conserved elements and mechanisms of the trafficking machinery over the last decade. Although functional studies of protein secretion in plants are still fairly limited, the Arabidopsis genome sequence provides an opportunity to identify key players of vesicle trafficking that are conserved across the eukaryotic kingdoms. Here, we review and add to recent genome analyses of trafficking components and highlight some plant‐specific modifications of the common eukaryotic machinery. Furthermore, we discuss the evidence for targeted, polarised secretion in plant cells, and speculate about possible underlying cargo sorting processes at the trans ‐Golgi network and endosomes, based on what is known in animals and yeast.
Discrimination of Methanol and Ethanol Vapors by the Use of a Single Optical Sensor with a Microporous Sensitive Layer
2002-08-22

The sorption of methanol and ethanol vapors by a microporous glassy polycarbonate is studied. The increase of the refractive index of the polymer during analyte sorption is measured by surface plasmon resonance. Both analytes are sorbed into the micropores of the polymer showing different diffusion kinetics. The sensor response during analyte exposure is subdivided into different time channels. By evaluating this additional data dimension by neural networks, a simultaneous multicomponent analysis of binary mixtures of ethanol and methanol vapors is possible using the sensor response of only one single sensor. A feature extraction results in an interpretable model and an improved prediction with errors of 2.0% for methanol and 2.4% for ethanol.
Hybrid Cell Vaccination for Cancer Immune Therapy
2002-08-27

This chapter contains sections titled: Introduction Immunological Basis of the HCV Approach to Cancer Immune Therapy Tumor Antigenicity T-T Cell Collaboration in the Induction of Cellular Cytotoxic Immune Responses Vaccination Strategies for Cancer Immune Therapy HCV Conceptual Basis HCV in Preclinical Studies Clinical Experience with HCV Conclusion and Prospects
ChemInform Abstract: The Network Structure of RbNb4Cl11.
2002-08-27

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Syntheses, Antibacterial, Cytotoxic and Antifungal Effects of New 3‐Carboxy‐1‐phenacylpyridinium Salts (III).
2002-08-27

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Multiplicative renormalizability and quark propagator
2002-08-29

The renormalized Dyson-Schwinger equation for the quark propagator is\\nstudied, in Landau gauge, in a novel truncation which preserves multiplicative\\nrenormalizability. The renormalization constants are formally eliminated from\\nthe integral equations, and the running coupling explicitly enters the kernels\\nof the new equations. To construct a truncation which preserves multiplicative\\nrenormalizability, and reproduces the correct leading order perturbative\\nbehavior, non-trivial cancellations involving the full quark-gluon vertex are\\nassumed in the quark self-energy loop. A model for the running coupling is\\nintroduced, with infrared fixed point in agreement with previous\\nDyson-Schwinger studies of the gauge sector, and with correct logarithmic tail.\\nDynamical chiral symmetry breaking is investigated, and the generated quark\\nmass is of the order of the extension of the infrared plateau of the coupling,\\nand about three times larger than in the Abelian approximation, which violates\\nmultiplicative renormalizability. The generated scale is of the right size for\\nhadronic phenomenology, without requiring an infrared enhancement of the\\nrunning coupling.\\n