X-Ray Diffraction Studies on Alicyclic Saturated Discotic Liquid Crystals

The discotic liquid crystalline phase of a new class of disc-like molecules (hexa-O-alkanoylscyllo- inositoles) is studied by small angle X-ray scattering, DSC and optical observations. Comparison of these three methods allows the determination of the structural arrangement. X-ray film exposures of oriented samples clearly demonstrate the hexagonal columnar ordered type of mesophases. A simple model calculation shows that the alkyl chains of neighbouring columns interpenetrate each other to a small extent

Digitalisierungsforschung: Wie wir die digitale Transformation wissenschaftlich erfassen können

Die Digitalisierungsforschung ist ein junges und sehr dynamisches Feld. Sie umfasst die Erforschung der Bedingungen und Auswirkungen der sozialen, politischen, wirtschaftlichen, kulturellen und technischen Veränderungen, die mit der Digitalisierung einhergehen. Neben zahlreichen neuen Forschungsfragen, die es zu beantworten gilt, fordert die Digitalisierung die Organisation von Forschung und den Umgang mit Daten heraus. Das ist sowohl Chance als auch Herausforderung für die Forschung. Die vorliegende Ausgabe von "easy_social_sciences" möchte sich in vier Beiträgen mit verschiedenen Aspekten der Digitalisierungsforschung befassen. Dabei werden unterschiedliche Perspektiven von der Konzeption relevanter Forschungsfragen über die Erhebung und Verarbeitung neuer Datentypen bis zur Kommunikation wissenschaftlicher Ergebnisse beleuchtet.Research on digital transformation is a young and very dynamic field. It encompasses research regarding the conditions and effects of the social, political, economic, cultural, and technical changes that accompany the digital transformation. In addition to numerous new research questions that need to be answered, digital transformation challenges the organization of research and the handling of data. This is both an opportunity and a challenge for research. This issue of "easy_social_sciences" aims to take a closer look at different aspects of research on digital transformation ranging from the conceptualization of relevant research questions to collecting and processing data and communicating results to the general public. In doing so, different perspectives on the challenges for working with digital data, as well as questions dealing with the dialogue between science and society in the context of digitization research are highlighted

The Crystal and Mesophase Structure of Hexakis(alkylsulfono)- benzene Homologues by X-Ray Diffractometry

A powder X-ray diffractometer study of hexakis(tridecylsulfono)benzene (HASB13) has been carried out over the temperature range 20 to above 80 °C. In this range three phase transitions are observed by sharp discontinuities in the diffraction pattern indicating a solid-solid, solidmesophase, and mesophase-liquid transition. The mesomorphic phase is identified as a hexagonal columnar discotic mesophase, Dhd, with intercolumnar spacing of 25.7 Å and average stacking distance of 4.9 Å. Both distances are independent of temperature but there appears to be a gradual increase in the stacking disorder as the temperature is increased. The magnitude of the intercolumnar distance suggests a considerable degree of side chain disorder. A detailed X-ray diffraction study was also performed at room temperature on a single crystal of hexakis(propylsulfono) benzene (HASB3), which is not mesogenic. The results provide detailed information on the structure of HASB 3 which is used in the interpretation of HASB 13 results

Digitalisierungsforschung: Ein Einblick in die Bandbreite der Forschung zu und mit digitalen Daten

"Daten sind das neue Öl" - dieser plakative Slogan der Werbeindustrie verdeutlicht den Boom in der Auswertung und Nutzung digitaler Daten in den letzten beiden Jahrzehnten. Kommerzielle Anbieter nutzen diese Daten, um immer mehr und immer detailliertere Informationen über ihre Nutzenden und Kund*innen zu erheben und ihre Produkte so personalisieren und weiterentwickeln zu können. Aber digitale Daten können nicht nur zur Gewinnmaximierung genutzt werden. Auch die (sozial-)wissenschaftliche Forschung nutzt immer häufiger solche Daten und erforscht Verhalten im digitalen Kontext. Digitale Forschungsdaten bringen dabei, genau wie das "alte Öl", enorme Potenziale, aber auch große Herausforderungen mit sich. In dieser Ausgabe von easy_social_sciences möchten wir daher einen Einblick in die vielfältigen disziplinären, methodischen und inhaltlichen Ansätze zur Forschung mit und über digitale Daten geben, um einen Eindruck zu vermitteln, wie sie genutzt werden können, um neue Forschungspotenziale zu erschließen."Data is the new oil" - this illustrative quote from the advertising industry underlines the boom in the analysis and use of digital data in recent decades. Commercial providers use this data to collect increasingly detailed information about their users and customers in order to develop and personalize their products and services. But digital data cannot only be used to maximize profits. (Social) scientific research is also making increasing use of such data and investigating behavior in a digital context. However, digital research data, just like the proverbial "oil", comes not only with enormous potentials but also great challenges. In this issue of easy_social_sciences, we thus provide an overview of the diverse disciplinary, methodological, and substantive approaches to research with and about digital data. In doing do, we aim to underline how these kinds of data can be used to exploit new research opportunities

Phase I study of intermittent and chronomodulated oral therapy with capecitabine in patients with advanced and/or metastatic cancer

BACKGROUND: The combination of capecitabine and gemcitabine at Fixed Dose Rate (FDR) has been demonstrated to be well tolerated, with apparent efficacy in patients with advanced cancers. FDR gemcitabine infusion leads to enhanced intracellular accumulation of drug and possible augmented clinical effect. The goals of this phase I study were to determine the maximum-tolerated dose (MTD) of chronomodulated capecitabine in patients with advanced cancer and to describe the dose-limiting toxicities (DLT), the safety profile of this way of administration. METHODS: Patients with advanced solid tumours who had failed to response to standard therapy or for whom no standard therapy was available were elegible for this study. Capecitabine was administered orally according to following schedule: 1/4 of dose at 8:00 a.m.; 1/4 of dose at 6:00 p.m. and 1/2 of dose at 11:00 p.m. each day for 14 consecutive days, followed by a 7-day rest period. RESULTS: All 27 patients enrolled onto the study were assessable for toxicity. The most common toxicities during the first two cycles of chemotherapy were fatigue, diarrhoea and hand foot syndrome (HFS). Only one out of the nine patients treated at capecitabine dose of 2,750 mg/m(2 )met protocol-specified DLT criteria (fatigue grade 4). However, at these doses the majority of cycles of therapy were delivered without dose reduction or delay. No other episodes of DLT were observed at the same dose steps and at the lower dose steps of capecitabine (1,500/1,750/2,000/2,250/2,500 mg/m(2)). The dose of 2,750 mg/m(2 )is recommended for further study. Tumor responses were observed in patients with metastatic breast and colorectal cancer. CONCLUSION: High doses of chronomodulated capecitabine can be administered with acceptable toxicity. The evidence of antitumor activity deserves further investigation in phase II combination chemotherapy studies

Multi-Jet Event Rates in Deep Inelastic Scattering and Determination of the Strong Coupling Constant

Jet event rates in deep inelastic ep scattering at HERA are investigated applying the modified JADE jet algorithm. The analysis uses data taken with the H1 detector in 1994 and 1995. The data are corrected for detector and hadronization effects and then compared with perturbative QCD predictions using next-to-leading order calculations. The strong coupling constant alpha_S(M_Z^2) is determined evaluating the jet event rates. Values of alpha_S(Q^2) are extracted in four different bins of the negative squared momentum transfer~\qq in the range from 40 GeV2 to 4000 GeV2. A combined fit of the renormalization group equation to these several alpha_S(Q^2) values results in alpha_S(M_Z^2) = 0.117+-0.003(stat)+0.009-0.013(syst)+0.006(jet algorithm).Comment: 17 pages, 4 figures, 3 tables, this version to appear in Eur. Phys. J.; it replaces first posted hep-ex/9807019 which had incorrect figure 4

Multiplicity Structure of the Hadronic Final State in Diffractive Deep-Inelastic Scattering at HERA

The multiplicity structure of the hadronic system X produced in deep-inelastic processes at HERA of the type ep -> eXY, where Y is a hadronic system with mass M_Y< 1.6 GeV and where the squared momentum transfer at the pY vertex, t, is limited to |t|<1 GeV^2, is studied as a function of the invariant mass M_X of the system X. Results are presented on multiplicity distributions and multiplicity moments, rapidity spectra and forward-backward correlations in the centre-of-mass system of X. The data are compared to results in e+e- annihilation, fixed-target lepton-nucleon collisions, hadro-produced diffractive final states and to non-diffractive hadron-hadron collisions. The comparison suggests a production mechanism of virtual photon dissociation which involves a mixture of partonic states and a significant gluon content. The data are well described by a model, based on a QCD-Regge analysis of the diffractive structure function, which assumes a large hard gluonic component of the colourless exchange at low Q^2. A model with soft colour interactions is also successful.Comment: 22 pages, 4 figures, submitted to Eur. Phys. J., error in first submission - omitted bibliograph

Differential (2+1) Jet Event Rates and Determination of alpha_s in Deep Inelastic Scattering at HERA

Events with a (2+1) jet topology in deep-inelastic scattering at HERA are studied in the kinematic range 200 < Q^2< 10,000 GeV^2. The rate of (2+1) jet events has been determined with the modified JADE jet algorithm as a function of the jet resolution parameter and is compared with the predictions of Monte Carlo models. In addition, the event rate is corrected for both hadronization and detector effects and is compared with next-to-leading order QCD calculations. A value of the strong coupling constant of alpha_s(M_Z^2)= 0.118+- 0.002 (stat.)^(+0.007)_(-0.008) (syst.)^(+0.007)_(-0.006) (theory) is extracted. The systematic error includes uncertainties in the calorimeter energy calibration, in the description of the data by current Monte Carlo models, and in the knowledge of the parton densities. The theoretical error is dominated by the renormalization scale ambiguity.Comment: 25 pages, 6 figures, 3 tables, submitted to Eur. Phys.

Measurements of Transverse Energy Flow in Deep-Inelastic Scattering at HERA

Measurements of transverse energy flow are presented for neutral current deep-inelastic scattering events produced in positron-proton collisions at HERA. The kinematic range covers squared momentum transfers Q^2 from 3.2 to 2,200 GeV^2, the Bjorken scaling variable x from 8.10^{-5} to 0.11 and the hadronic mass W from 66 to 233 GeV. The transverse energy flow is measured in the hadronic centre of mass frame and is studied as a function of Q^2, x, W and pseudorapidity. A comparison is made with QCD based models. The behaviour of the mean transverse energy in the central pseudorapidity region and an interval corresponding to the photon fragmentation region are analysed as a function of Q^2 and W.Comment: 26 pages, 8 figures, submitted to Eur. Phys.

Energy Flow in the Hadronic Final State of Diffractive and Non-Diffractive Deep-Inelastic Scattering at HERA

An investigation of the hadronic final state in diffractive and non--diffractive deep--inelastic electron--proton scattering at HERA is presented, where diffractive data are selected experimentally by demanding a large gap in pseudo --rapidity around the proton remnant direction. The transverse energy flow in the hadronic final state is evaluated using a set of estimators which quantify topological properties. Using available Monte Carlo QCD calculations, it is demonstrated that the final state in diffractive DIS exhibits the features expected if the interaction is interpreted as the scattering of an electron off a current quark with associated effects of perturbative QCD. A model in which deep--inelastic diffraction is taken to be the exchange of a pomeron with partonic structure is found to reproduce the measurements well. Models for deep--inelastic $ep$ scattering, in which a sizeable diffractive contribution is present because of non--perturbative effects in the production of the hadronic final state, reproduce the general tendencies of the data but in all give a worse description.Comment: 22 pages, latex, 6 Figures appended as uuencoded fil