cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Polymorphism analysis in estrogen receptors alpha and beta genes and their association with infertile population in Pakistan
Creators: name: Liaqat, Sinha
name: Hasnain, Shahida
name: Muzammil, Saima
name: Hayat, Sumreen
Publisher: name: Technische Universität Dortmund
Year: 2015
Subjects: subject: estrogen receptor
subject: infertility
subject: polymorphism
subject: haplotype
subject: genetic
subject: linkage disequilibrium
subject: 610

description: Studies on polymorphism of estrogen receptor (ESR) alpha and beta genes have been mostly implicated in infertility, but the results have been controversial due to lack of comprehensive data. The present study focused on association of ESR genes with both male and female infertility. In ESRα, PvuII (rs2234693) and XbaI (rs9340799) were studied while in ESRβ gene, risk of infertility was determined for silent G/A RsaI (rs1256049) polymorphism. Total 124 subjects (74 cases and 50 controls) were part of this study having primary infertility. Restriction fragment length polymorphism (RFLP) was performed with PvuII, XbaI and RsaI to determine polymorphism. Correlation between age and follicle stimulating hormone (FSH) of cases and controls was determined and no association was found between infertility and FSH hormone. Heterozygous AG genotype of XbaI polymorphism (P= 2.505e-06) and heterozygous TC genotype (P= 0.00003) in PvuII polymorphism were strongly associated with risk of infertility. In ESRβ gene, there was lack of polymorphism for RsaI in our population as all subjects were homozygous (GG). Haplotype frequencies showed that XbaI and PvuII polymorphisms are in strong linkage disequilibrium. This study shows that in our population XbaI and PvuII polymorphisms of ESRα are associated with risk of infertility.
description: EXCLI Journal;Vol. 14, 2015
Maximally-fast coarsening algorithms
Creators: name: Cheng, Mowei
name: Rutenberg, Andrew
Publisher: name: arXiv
Year: 2005
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We present maximally-fast numerical algorithms for conserved coarsening systems that are stable and accurate with a growing natural time-step $Δt=A t_s^{2/3}$. For non-conserved systems, only effectively finite timesteps are accessible for similar unconditionally stable algorithms. We compare the scaling structure obtained from our maximally-fast conserved systems directly against the standard fixed-timestep Euler algorithm, and find that the error scales as $\sqrt{A}$ -- so arbitrary accuracy can be achieved.
description: 5 pages, 3 postscript figures, Latex
Anisotropic magnetoresistance and spin polarization of La0.7Sr0.3MnO3 / SrTiO3 superlattices
Creators: name: Wang, L. M.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The crystalline structure, anisotropic magnetoresistance (AMR), and magnetization of La0.7Sr0.3MnO3/SrTiO3 (LSMO/STO) superlattices grown by an rf sputtering system are systematically analyzed to study the spin polarization of manganite at interfaces. A perfectly epitaxial growth with sharp interfaces between LSMO and STO layers is confirmed by the transmission electron microscopy (TEM) image and the x-ray diffraction. The presence of positive low-temperature AMR in LSMO/STO superlattices with thinner LSMO layers or thicker STO layers implies that two bands of majority and minority character contribute to the transport properties, leading to a reduced spin polarization. Furthermore, the magnetization of superlattices follows the T3/2 law at low temperatures and decays more quickly as the thickness ratio dSTO/dLSMO increases, corresponding to a reduced exchange coupling. The results clearly show that the spin polarization is strongly correlated with the influence of interface-induced strain on the structure.
description: 21 pages, 5 figures
Using Spatio-temporal Deep Learning for Forecasting Demand and Supply-demand Gap in Ride-hailing System with Anonymised Spatial Adjacency Information
Creators: name: Rahman, M. H.
name: Rifaat, S. M.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: To reduce passenger waiting time and driver search friction, ride-hailing companies need to accurately forecast spatio-temporal demand and supply-demand gap. However, due to spatio-temporal dependencies pertaining to demand and supply-demand gap in a ride-hailing system, making accurate forecasts for both demand and supply-demand gap is a difficult task. Furthermore, due to confidentiality and privacy issues, ride-hailing data are sometimes released to the researchers by removing spatial adjacency information of the zones, which hinders the detection of spatio-temporal dependencies. To that end, a novel spatio-temporal deep learning architecture is proposed in this paper for forecasting demand and supply-demand gap in a ride-hailing system with anonymized spatial adjacency information, which integrates feature importance layer with a spatio-temporal deep learning architecture containing one-dimensional convolutional neural network (CNN) and zone-distributed independently recurrent neural network (IndRNN). The developed architecture is tested with real-world datasets of Didi Chuxing, which shows that our models based on the proposed architecture can outperform conventional time-series models (e.g., ARIMA) and machine learning models (e.g., gradient boosting machine, distributed random forest, generalized linear model, artificial neural network). Additionally, the feature importance layer provides an interpretation of the model by revealing the contribution of the input features utilized in prediction.
description: arXiv admin note: text overlap with arXiv:2012.15408
RISK AND EQUITY IN AGRICULTURAL COOPERATIVES
Creators: name: Parliament, Claudia
name: Lerman, Zvi
name: Huseby, Dana
name: Parliament, Claudia
name: Lerman, Zvi
name: Huseby, Dana
Publisher: name: Unknown
Year: 1991
Subjects: Agribusiness

description: This research examines the effects of risk-related factors on the proportion of equity held by agricultural cooperatives. The empirical analysis indicates that capital structure is significantly affected by the level and variation of profitability, commodities handled, and market function. The proportion of equity is not affected by size or pooling. Contrary to expectations, the results indicate an inverse relation between profit variability and the proportion of equity. Cooperatives rely on profit for equity accumulation through retained earnings. If this source of equity is unstable, the cooperative may not be able to generate sufficient equity causing the estimated inverse relationship.
Effects of zinc against mercury toxicity in female rats 12 and 48 hours after HgCl2 exposure
Creators: name: Mesquita, Mariana
name: Pedroso, Taíse F.
name: Oliveira, Cláudia S.
name: Oliveira, Vitor A.
name: Do Santos, Rafael Francisco
name: Bizzi, Cezar Augusto
name: Pereira, Maria E.
Publisher: name: Technische Universität Dortmund
Year: 2016
Subjects: subject: females
subject: nephrotoxicity
subject: acute
subject: mercury
subject: zinc
subject: 610

description: This work investigated the toxicity of inorganic mercury and zinc preventive effects in female rats sacrificed 12 or 48 h after HgCl2 exposure. Female Wistar rats were subcutaneously injected with ZnCl2 (27 mg/kg) or saline (0.9 %), and 24 h later they were exposed to HgCl2 (5 mg/kg) or saline (0.9 %). Rats sacrificed 12 hours after Hg administration presented an increase in kidney weight and a decrease in renal ascorbic acid levels. Zinc pretreatment prevented the renal weight increase. Rats sacrificed 48 h after Hg exposure presented a decrease in body weight gain, an increase in renal weight, a decrease in renal δ-aminolevulinic acid dehydratase activity, an increase in serum creatinine and urea levels, and a decrease in kidney total thiol levels. Zinc pretreatment partly prevented the decrease in body weight gain and increase in creatinine levels, in addition to totally preventing renal δ-aminolevulinic acid dehydratase inhibition. Mercury accumulation in the kidney and liver in both periods was observed after Hg administration. These results show the different Hg effects along the time of intoxication, and a considerably preventive effect of zinc against Hg toxicity.
description: EXCLI Journal;Vol. 15, 2016
Central Charges in Non(anti)commutative N=2 Supersymmetric U(N) Gauge Theory
Creators: name: Ito, Katsushi
name: Nakajima, Hiroaki
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study the central charge of the deformed N=(1,0) supersymmetry algebra in non(anti)commutative N=2 supersymmetric U(N) gauge theory. In the cases of N=1/2 superspace and N=2 harmonic superspace with the singlet deformation, we find that the central charge is deformed by the non(anti)commutative parameters but depends on the electric and magnetic charges. For generic deformation of N=2 harmonic superspace, we compute the O(C) correction to the central charges in the case of U(1) gauge group.
description: 13 pages, No figure, v2:minor corrections, references added
The Minimum Leidenfrost Temperature on Smooth Surfaces
Creators: name: Harvey, Dana
name: Harper, Joshua Mendez
name: Burton, Justin C.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: During the Leidenfrost effect, a thin insulating vapor layer separates an evaporating liquid from a hot solid. Here we demonstrate that Leidenfrost vapor layers can be sustained at much lower temperatures than those required for formation. Using a high-speed electrical technique to measure the thickness of water vapor layers over smooth, metallic surfaces, we find that the explosive failure point is nearly independent of material and fluid properties, suggesting a purely hydrodynamic mechanism determines this threshold. For water vapor layers of several millimeters in size, the minimum temperature for stability is $\approx 140^{\circ}$C, corresponding to an average vapor layer thickness of 10-20$μ$m.
description: 6 pages, 4 figures, Supplemental information attached. Supplemental videos available upon request
title: Πολυπληθυσμιακά μοντέλα πρόβλεψης του ρυθμού θνησιμότητας στην Ελλάδα και επιπτώσεις στα συνταξιοδοτικά ταμεία
title: Multi-population modelling of Greek mortality rates and applications to pension plans
titleType: AlternativeTitle
Creators: name: Κρατημένου, Ελένη
Publisher: name: Πανεπιστήμιο Πειραιώς
Year: 2020
Subjects: subject: Mortality rates
subject: Population
subject: Projection
subject: Forecast
subject: Pricing
subject: Multi-population models
subject: Lee-Carter model

description: Μια από τις πιο έντονες προκλήσεις της εποχής μας σε κοινωνικό και οικονομικό επίπεδο είναι η ραγδαία αύξηση της μακροζωίας και η γήρανση του πληθυσμού σε παγκόσμια κλίμακα. Στη προσπάθεια να αντιμετωπιστεί αυτή η πρόκληση αναπτύσσονται συνεχώς μοντέλα με σκοπό την πρόβλεψη του ρυθμού θνησιμότητας. Κύρια πηγή πληροφοριών για την ανάπτυξη αυτών των μοντέλων είναι τα ιστορικά στοιχεία, αλλά κρίνεται απαραίτητη και η κριτική σκέψη ειδικών επιστημόνων. Η παρούσα εργασία παρουσιάζει μερικά από τα κυριότερα μοντέλα θνησιμότητας της βιβλιογραφίας και δίνεται ιδιαίτερη έμφαση στο μοντέλο Lee-Carter (1992) καθώς είναι ένα μοντέλο ευρέως γνωστό για την πρόβλεψη της θνησιμότητας. Στη συνέχεια, αναλύονται τρία από τα κύρια πολύ-πληθυσμιακά μοντέλα, τα οποία έχουν ως βάση το μοντέλο Lee-Carter (1992) και παρέχουν τη δυνατότητα ταυτόχρονης μοντελοποίησης δύο και άνω πληθυσμών. Με δεδομένα από τον πληθυσμό της Ελλάδας, για άνδρες και γυναίκες, εφαρμόζεται η μεθοδολογία των μοντέλων και για τους δύο πληθυσμούς ταυτόχρονα και υπολογίζονται οι προβλέψεις των δεικτών θνησιμότητας. Έπειτα, κατασκευάζονται πίνακες θνησιμότητας με βάσει τους προβεβλημένους δείκτες θνησιμότητας με σκοπό την τιμολόγηση ασφαλιστικών προϊόντων. Σκοπός της εργασίας είναι να εξετάσει την προβλεπτική ικανότητα των πολύ-πληθυσμιακών μοντέλων θνησιμότητας δύο πληθυσμών σε σύγκριση με τις ανεξάρτητες προβλέψεις μέσω του μοντέλου Lee-Carter (1992).
Σύγχρονες πρακτικές διοίκησης ανθρώπινου δυναμικού: επιπτώσεις στην εργασιακή ικανοποίηση και στην εργασιακή απόδοση
Creators: name: Καλκανάκου, Λουκία
Publisher: name: Πανεπιστήμιο Πειραιώς
Year: 2021
Subjects: subject: Διοίκηση ανθρώπινου δυναμικού
subject: Επιλογή προσωπικού
subject: Εκπαίδευση
subject: Αξιολόγηση απόδοσης
subject: Ικανοποίηση εργαζομένων

description: Η διοίκηση ανθρώπινου δυναμικού αποτελεί μία από τις σημαντικότερες λειτουργίες σε έναν οργανισμό, καθώς οι άνθρωποι αποτελούν σημαντικό ανταγωνιστικό πλεονέκτημα για μία επιχείρηση. Ιδιαίτερα, μάλιστα, στη σύγχρονη εποχή, καλείται να αντιμετωπίσει ένα σύνολο από προκλήσεις, οι οποίες επιβάλλουν την ύπαρξη ευελιξίας αλλά και την ανάπτυξη μεθοδολογιών, οι οποίες θέτουν τον εργαζόμενο στο επίκεντρο. Οι βασικές λειτουργίες του τμήματος διοίκησης ανθρώπινων πόρων, όπως η επιλογή προσωπικού, η εκπαίδευση και η αξιολόγηση της απόδοσης, δύνανται να συμβάλλουν στην αύξηση του βαθμού εργασιακής ικανοποίησης και, συνακόλουθα, στην αποδοτικότητα των εργαζομένων. Σκοπός της παρούσας εργασίας είναι να παρουσιαστούν οι σύγχρονες πρακτικές της διοίκησης ανθρώπινου δυναμικού, διερευνώντας τις συνέπειες τους στην εργασιακή ικανοποίηση και απόδοση. Για το σκοπό αυτό, πραγματοποιήθηκε μελέτη περίπτωσης την εταιρεία Leroy Merlin, στην οποία παρουσιάστηκαν οι απόψεις των εργαζομένων, αναφορικά με σημαντικές συνιστώσες της διοίκησης ανθρώπινου δυναμικού, όπως η επιλογή, η εκπαίδευση και η αξιολόγηση. Όπως καταδείχθηκε, η υιοθέτηση σαφώς καθορισμένων διαδικασιών έχει ως επακόλουθο την ύπαρξη ικανοποιημένων εργαζομένων, οι οποίοι διαθέτουν υψηλή δέσμευση και ταύτιση με την κουλτούρα του οργανισμού.
Formation and Evolution of Planetary Systems: Placing Our Solar System in Context with Spitzer
Creators: name: Meyer, Michael R.
name: Team, the FEPS Legacy Science
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We summarize the progress to date of our Legacy Science Program entitled "The Formation and Evolution of Planetary Systems" (FEPS) based on observations obtained with the Spitzer Space Telescope during its first year of operation. In addition to results obtained from our ground-based preparatory program and our early validation program, we describe new results from a survey for near-infrared excess emission from the youngest stars in our sample as well as a search for cold debris disks around sun-like stars. We discuss the implications of our findings with respect to current understanding of the formation and evolution of our own solar system.
description: 8 postscript pages including 3 figures. To appear in "Spitzer New Views of the Cosmos" ASP Conference Series, eds. L. Armus et al. FEPS website at http://feps.as.arizona.edu
MINNESOTA CURRENT FARM SITUATION
Creators: name: Buhr, Brian L.
name: Lazarus, William F.
name: Nefstead, Ward E.
name: Nordquist, Dale W.
name: Olson, Kent D.
name: Stevens, Stanley C.
name: Weness, Erlin J.
name: Buhr, Brian L.
name: Lazarus, William F.
name: Nefstead, Ward E.
name: Nordquist, Dale W.
name: Olson, Kent D.
name: Stevens, Stanley C.
name: Weness, Erlin J.
Publisher: name: Unknown
Year: 1998
Subjects: Farm Management

description: These papers describe the current economic conditions and outline some of the opportunities facing Minnesota farmers as they complete 1998 and develop plans for 1999. The first paper, Prospects For Farm Income in 1998, describes the variation in net farm income farmers in the Southeastern and Southwestern Farm Management Associations have experienced over the past twenty years. The possible effects of 1998's low commodity prices and government program payments on net farm income are discussed in the context of this historical variation. This paper points out that some farmers are experiencing a very good year in 1998, while others may have very low net farm income this year. Those with high incomes in 1998 may be primarily interested in opportunities to enhance their cash flow for 1999, while those experiencing financial stress during 1998 may need to consider a wider range of adjustments as they plan for the coming year. The remaining papers provide information farmers may want to consider as they plan their marketing and financial strategies for the coming year. Financial Management Alternatives outlines a wide range of financial management alternatives that can be used to deal with cash flow problems. Some of these alternatives will be of interest to farmers who have difficulty in projecting a positive net cash flow with the relatively low commodity prices being projected for 1999. Others are of primary interest to farmers who have relatively high debt levels and must find ways to improve both their net cash flow and their debt/asset position. Some observers have suggested that the low commodity prices projected for 1999 may lead to reductions in cash rental rates. The paper, Cropland Rental Market Impacts of Low Crop Prices, discusses a procedure to estimate "fair rental rates", and provides an historical perspective of the impact low commodity prices have had on land rental rates. The remaining two papers, Situation and Outlook For the Livestock Sector, and Considerations in Developing a Corn/Soybean Marketing Plan for 1998/1999, discuss the major factors to evaluate and options to consider in developing a marketing plan for corn, soybeans, hogs and cattle for the coming year.
title: Determination of rail vehicle speed with acoustic signal processed using continuous wavelet transform
Creators: name: Mokrzan, Daniel
name: Nowakowski, Tomasz
name: Szymański, Grzegorz M.
Publisher: name: Publishing House of Poznan University of Technology
Year: 2023

description: Vibrations in Physical Systems, 34(2), 2023223-1 - 2023223-8
HDAC inhibitors, MS-275 and salermide, potentiates the anticancer effect of EF24 in human pancreatic cancer cells
Creators: name: Yar Saglam, Atiye Seda
name: Yilmaz, Akın
name: Onen, Hacer Ilke
name: Alp, Ebru
name: Kayhan, Handan
name: Ekmekci, Abdullah
Publisher: name: Technische Universität Dortmund
Year: 2016
Subjects: subject: BxPC-3 cells
subject: EF24
subject: HDACI
subject: MS-275
subject: salermide
subject: pancreatic cancer
subject: 610

description: Histone deacetylases (HDACs) play a major role in the regulation of chromatin structure and gene expression by changing acetylation status of histone and non-histone proteins. MS-275 (entinostat, MS) is a well-known benzamide-based HDACI and Salermide (SAL), a reverse amide compound HDACI, have antiproliferative effects on several human cancer cells. In this study, we aimed to investigate the effects of HDACIs (MS and SAL) alone and/or combined use with EF24 (EF), a novel synthetic curcumin analog, on human pancreatic cancer cell line (BxPC-3). In vitro, BxPC-3 cells were exposed to varying concentrations of MS, SAL with or without EF, and their effects on cell viability, acetylated Histone H3 and H4 levels, cytotoxicity, and cleaved caspase 3 levels, and cell cycle distribution were measured. The viability of BxPC-3 cells decreased significantly after treatment with EF, MS and SAL treatments. MS and SAL treatment increased the acetylation of histone H3 and H4 in a dose dependent manner. MS and SAL alone or combined with EF were increased the number of cells in G1 phase. In addition, treatment with agents significantly decreased the ratio of cell in G2/M phase. There were significant dose-dependent increases at cleaved Caspase 3 levels after MS treatment but not after SAL treatment. Our results showed that HDAC inhibitors (MS and SAL), when combined with EF, may effectively reduce pancreatic cancer cell (BxPC-3) progression and stop the cell cycle at G1 phase. Further molecular analyses are needed to understand the fundamental molecular consequences of HDAC inhibition in pancreas cancer cells.
description: EXCLI Journal;Vol. 15, 2016
Spiral Arm Pattern Motion in the SAO 206462 Protoplanetary Disk
Creators: name: Xie, Chengyan
name: Ren, Bin
name: Dong, Ruobing
name: Pueyo, Laurent
name: Ruffio, Jean-Baptiste
name: Fang, Taotao
name: Mawet, Dimitri
name: Stolker, Tomas
Publisher: name: arXiv
Year: 2020
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Spiral arms have been observed in more than a dozen protoplanetary disks, yet the origin of nearly all systems is under debate. Multi-epoch monitoring of spiral arm morphology offers a dynamical way in distinguishing two leading arm formation mechanisms: companion-driven, and gravitational instability induction, since these mechanisms predict distinct motion patterns. By analyzing multi-epoch J-band observations of the SAO 206462 system using the SPHERE instrument on the Very Large Telescope (VLT) in 2015 and 2016, we measure the pattern motion for its two prominent spiral arms in polarized light. On one hand, if both arms are comoving, they can be driven by a planet at $86_{-13}^{+18}$ au on a circular orbit, with gravitational instability motion ruled out. On the other hand, they can be driven by two planets at $120_{-30}^{+30}$ au and $49_{-5}^{+6}$ au, offering a tentative evidence (3.0$σ$) that the two spirals are moving independently. The independent arm motion is possibly supported by our analysis of a re-reduction of archival observations using the NICMOS instrument onboard the Hubble Space Telescope (HST) in 1998 and 2005, yet artifacts including shadows can manifest spurious arm motion in HST observations. We expect future re-observations to better constrain the motion mechanism for the SAO 206462 spiral arms.
description: 9 pages, 4 figures, 1 table. Updated correct data files for SPHERE and NICMOS observations available in ancillary folder
Οι διαστάσεις της πράσινης επιχειρηματικότητας: το φαινόμενο του greenwashing
Creators: name: Στεφάνου, Παναγιώτης
Publisher: name: Πανεπιστήμιο Πειραιώς
Year: 2020
Subjects: subject: Πράσινη επιχειρηματικότητα
subject: Πράσινο μάρκετινγκ
subject: Greenwashing

description: Τις τελευταίες δεκαετίες, παρατηρείται στην Ελλάδα, όπως και σε πολλά άλλα ανεπτυγμένα κράτη, ένα συνεχώς αυξανόμενο ενδιαφέρον για το περιβάλλον, που πλαισιώνεται από μια συνεχή αναζήτηση τρόπων προστασίας του από τις διάφορες απειλές. Το γεγονός αυτό έχει συμβάλλει στη δημιουργία και την προώθηση της πράσινης επιχειρηματικής δράσης, καθώς και των πράσινων προϊόντων και υπηρεσιών. Αυτό είναι επακόλουθο της γενικότερης ευαισθητοποίησης των καταναλωτών όσον αφορά τα περιβαλλοντικά θέματα και δημιουργεί μία νέα πραγματικότητα στην αγορά. Η προσπάθεια προσαρμογής σε αυτή τη νέα πραγματικότητα, σε συνδυασμό με τον υψηλό ανταγωνισμό μεταξύ των επιχειρήσεων, όμως, έχουν οδηγήσει ένα, εκ πρώτης όψεως εξολοκλήρου θετικό φαινόμενο, αυτό της πράσινης επιχειρηματικότητας και του πράσινου μάρκετινγκ, να εμφανίζει κάποιες αρνητικές πτυχές. Το φαινόμενο του «greenwashing» είναι ένα από τα κυριότερα ψεγάδια της σύγχρονης οικολογικής δράσης των επιχειρήσεων και των οργανισμών. Στην παρούσα διπλωματική εργασία, παρουσιάζονται όλες οι διαστάσεις της πράσινης επιχειρηματικότητας και αναλύονται οι όροι πράσινο μάρκετινγκ και πράσινο ξέπλυμα. Κύριος στόχος της εργασίας είναι η διερεύνηση των παραπάνω εννοιών και η περεταίρω εμβάθυνση στον όρο «greenwashing» και την επιρροή που έχει στους καταναλωτές και στις επιχειρήσεις. Την θεωρητική ανάλυση, λοιπόν, συμπληρώνουν η μελέτη πραγματικών περιπτώσεων greenwashing που παρατηρήθηκαν σε επιχειρήσεις του εξωτερικού, αλλά και η έρευνα με τη μορφή ερωτηματολογίου που έγινε σε ένα δείγμα του ελληνικού καταναλωτικού κοινού.
Testing the chemical homogeneity of chemically tagged dissolved birth clusters
Creators: name: Cheng, Chloe M.
name: Price-Jones, Natalie
name: Bovy, Jo
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Chemically tagging stars back to common formation sites in the Milky Way and establishing a high level of chemical homogeneity in these chemically tagged birth clusters is crucial for understanding the chemical and dynamical history of the Galactic disc. We constrain the intrinsic abundance scatter in 17 newly chemically tagged dissolved birth clusters found in the APOGEE survey by modelling APOGEE spectra as a one-dimensional function of initial stellar mass, performing forward modelling of the observed stellar spectra, then comparing the data and simulations using Approximate Bayesian Computation. We exemplify this method with the well-known open clusters M67, NGC 6819, and NGC 6791. We study 15 elements measured by APOGEE and find that, in general, we are able to obtain very strong constraints on the intrinsic abundance scatter of most elements in the chemically tagged birth clusters, with upper limits of $\lesssim 0.02$ dex for C, $\lesssim 0.03$ dex for O, Mn, and Fe, $\lesssim 0.04$ dex for Si and Ni, and $\lesssim 0.05$ dex for N, Mg, and Ca. While we find some evidence for a small amount of chemical inhomogeneity in the remaining elements (i.e. Na, Al, S, K, Ti, and V), we are still able to obtain similar or stronger limits compared to those found for open clusters, consistent with previous findings. By strongly constraining their level of chemical homogeneity, we can strengthen the statement that these groups of stars represent birth clusters, with promising implications for future chemical tagging studies.
description: MNRAS, in press
title: Η ικανοποίηση των εργαζομένων σε δημόσιο νοσοκομείο
title: Job satisfaction of employees in a public hospital
titleType: AlternativeTitle
Creators: name: Μιχαλοπούλου, Αικατερίνη
Publisher: name: Πανεπιστήμιο Πειραιώς
Year: 2020
Subjects: subject: Επαγγελματική ικανοποίηση
subject: Παράγοντες επαγγελματικής ικανοποίησης
subject: Δημόσια νοσοκομεία

description: Η επαγγελματική ικανοποίηση εδώ και κάποιες δεκαετίες μελετάται και έχει κινήσει το ενδιαφέρον πολλών ερευνητών. Η επαγγελματική ικανοποίηση ουσιαστικά, είναι το πώς αισθάνεται ένας εργαζόμενος για τη θέση εργασίας του, δείχνοντας τον βαθμό που αγαπά ή αντιπαθεί τη δουλειά του. Εξαρτάται από διάφορες προϋποθέσεις όπως τις αμοιβές, την προαγωγή, τη φύση της εργασίας, την αναγνώριση, τις συνθήκες λειτουργίας ,τους συναδέλφους, την επικοινωνία κ.α. Στην παρούσα έρευνα μελετήθηκε ο βαθμός ικανοποίησης των εργαζομένων ενός Ελληνικού δημόσιου νοσοκομείου. Η έρευνα ασχολείται με το ποσό οι παράγοντες που επηρεάζουν την επαγγελματική ικανοποίηση, επιδρούν στους εργαζομένους του νοσοκομείου. Στη συνέχεια, ακολουθεί συσχέτιση με δημογραφικούς και εργασιακούς παράγοντες όπως την ηλικία, τον κλάδο στον οποίο ανήκουν και το μορφωτικό τους επίπεδο. Συγκεκριμένα, στην έρευνα συμμετείχαν 80 εργαζόμενοι του νοσοκομείου, στους οποίους μοιράστηκε ένα ερωτηματολόγιο τον Ιούνιο του 2020. Το πρώτο μέρος του ερωτηματολογίου αφορά ερωτήσεις δημογραφικών χαρακτηριστικών και το δεύτερο αποτελείται από ερωτήσεις του γνωστού ερωτηματολογίου "Job Satisfaction Survey" του Paul Spector, που μετρά την εργασιακή ικανοποίηση. Τα ευρήματα της έρευνας, μας οδήγησαν στο συμπέρασμα πως οι εργαζόμενοι του νοσοκομείου βρίσκονται σε μέτρια επίπεδα ικανοποίησης, στα πρόθυρα δυσαρέσκειας. Τέλος, βρέθηκε ότι οι παράγοντες που επηρεάζουν αρνητικά την ικανοποίηση των εργαζόμενων είναι οι αμοιβές, η αναγνώριση, οι συνθήκες λειτουργίας, τα προνόμια και οι συνάδελφοι.
XMM-Newton observations of Abell 2255 : a test case of a merger after `core-crossing'
Creators: name: Sakelliou, Irini
name: Ponman, Trevor J.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: It has been known that Abell 2255 is not a relaxed cluster, but it is undergoing a merger. Here, we report on the analysis of the XMM-Newton observations of this cluster. The X-ray data give us the opportunity to reveal the complexity of the cluster, especially its temperature distribution. The integrated spectrum is well fitted by a single temperature thermal model, indicating a mean temperature of ~7 keV. However, the cluster is not isothermal at this temperature: its eastern regions are significantly cooler, at ~5.5 keV, whilst towards the West the temperature reaches ~8.5 keV. These temperature asymmetries can be explained if Abell 2255 has been assembled recently by the merging of smaller subunits. It is now in the phase after the cores of these subunits have collided (the `core-crossing' phase) some 0.1-0.2 Gyr ago. A comparison with numerical simulations suggests that it will settle down into a single relaxed cluster in ~(2-3) Gyr.
description: 9 pages, 6 figures, accepted by MNRAS
QSAR study of HCV NS5B polymerase inhibitors using the genetic algorithm-multiple linear regression (GA-MLR)
Creators: name: Rafiei, Hamid
name: Khanzadeh, Marziyeh
name: Mozaffari, Shahla
name: Bostanifar, Mohammad Hassan
name: Avval, Zhila Mohajeri
name: Aalizadeh, Reza
name: Pourbasheer, Eslam
Publisher: name: Technische Universität Dortmund
Year: 2016
Subjects: subject: QSAR
subject: genetic algorithms
subject: multiple linear regression
subject: HCV
subject: 610

description: Quantitative structure–activity relationship (QSAR) study has been employed for predicting the inhibitory activities of the Hepatitis C virus (HCV) NS5B polymerase inhibitors. A data set consisted of 72 compounds was selected, and then different types of molecular descriptors were calculated. The whole data set was split into a training set (80 % of the dataset) and a test set (20 % of the dataset) using principle component analysis. The stepwise (SW) and the genetic algorithm (GA) techniques were used as variable selection tools. Multiple linear regression method was then used to linearly correlate the selected descriptors with inhibitory activities. Several validation technique including leave-one-out and leave-group-out cross-validation, Y-randomization method were used to evaluate the internal capability of the derived models. The external prediction ability of the derived models was further analyzed using modified r2, concordance correlation coefficient values and Golbraikh and Tropsha acceptable model criteria's. Based on the derived results (GA-MLR), some new insights toward molecular structural requirements for obtaining better inhibitory activity were obtained.
description: EXCLI Journal;Vol. 15, 2016
Orbifold Compactification and Solutions of M--Theory from Milne Spaces
Creators: name: Bytsenko, A. A.
name: Guimaraes, M. E. X.
name: Kerner, R.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: Geometric Topology (math.GT)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: In this paper, we consider solutions and spectral functions of M-theory from Milne spaces with extra free dimensions. Conformal deformations to the metric associated with the real hyperbolic space forms are derived. For the three-dimensional case, the orbifold identifications $SL(2,{\mathbb Z}+i{\mathbb Z})/\{\pm Id\}$, where $Id$ is the identity matrix, is analyzed in detail. The spectrum of a eleven-dimensional field theory can be obtained with the help of the theory of harmonic functions in the fundamental domain of this group and it is associated with the cusp forms and the Eisenstein series. The supersymmetry surviving for supergravity solutions involving real hyperbolic space factors is briefly discussed.
description: 14 pages, no figures. To appear in The European Physical Journal C - Particles and Fields
Universality in the onset of quantum chaos in many-body systems
Creators: name: LeBlond, Tyler
name: Sels, Dries
name: Polkovnikov, Anatoli
name: Rigol, Marcos
Publisher: name: arXiv
Year: 2020
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Gases (cond-mat.quant-gas)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We show that the onset of quantum chaos at infinite temperature in two many-body one-dimensional lattice models, the perturbed spin-1/2 XXZ and Anderson models, is characterized by universal behavior. Specifically, we show that the onset of quantum chaos is marked by maxima of the typical fidelity susceptibilities that scale with the square of the inverse average level spacing, saturating their upper bound, and that the strength of the integrability- or localization-breaking perturbation at these maxima decreases with increasing system size. We also show that the spectral function below the ``Thouless'' energy (in the quantum-chaotic regime) diverges when approaching those maxima. Our results suggest that, in the thermodynamic limit, arbitrarily small integrability- or localization-breaking perturbations result in quantum chaos in the many-body quantum systems studied here.
description: 12 pages, 13 figures, as published
The effect of cold application and lavender oil inhalation in cardiac surgery patients undergoing chest tube removal
Creators: name: Hasanzadeh, Farzaneh
name: Kashouk, Narges Mohammadi
name: Amini, Shahram
name: Asili, Javad
name: Emami, Seyed Ahmad
name: Vashani, Hamidreza Behnam
name: Sahebkar, Amirhossein
Publisher: name: Technische Universität Dortmund
Year: 2016
Subjects: subject: chest tube
subject: pain
subject: anxiety
subject: cold application
subject: Lavandula angustifolia
subject: nursing
subject: 610

description: Post-surgical chest tube removal (CTR) is associated with a significant pain and discomfort for patients. Current treatment strategies for reducing CTR-associated pain and anxiety are limited and partially efficacious. To determine the effects of cold application, inhalation of lavender essential oil, and their combination on pain and anxiety during CTR was investigated. This randomized controlled open-label trial was conducted with 80 p atients in the cardiac surgery intensive care unit who had a chest tube for duration of at least 24 hours after coronary artery bypass grafting (CABG). Patients were randomized (n=20 in each group) to receive cold application, aromatherapy with lavender oil, cold application in combination with lavender oil inhalation, or none of the above interventions (control group). The intensity and quality of pain and anxiety were evaluated using the visual analogue scale, short form and modified-McGill pain questionnaire (SFM-MPQ) and the Spielberger situational anxiety level inventory (STAII) scale, respectively. Patients in all treatment groups had significantly lower pain intensity and anxiety compared with the control group immediately, 5, 10 and 15 min after CTR. There was no statistically significant difference in the SFM-MPQ total scores between the intervention groups. With respect to anxiety score, there was a significantly reduced anxiety level immediately after CTR in the aromatherapy and cold-aromatherapy combination groups versus the cold application group. The present results suggested the efficacy of cold application and aromatherapy with lavender oil in reducing pain and anxiety associated with post-CABG CTR.
description: EXCLI Journal;Vol. 15, 2016
Fast and robust all-electron density functional theory calculations in solids using orthogonalized enriched finite elements
Creators: name: Rufus, Nelson D.
name: Kanungo, Bikash
name: Gavini, Vikram
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: We present a computationally efficient approach to perform systematically convergent real-space all-electron Kohn-Sham DFT calculations for solids using an enriched finite element (FE) basis. The enriched FE basis is constructed by augmenting the classical FE basis with atom-centered numerical basis functions, comprising of atomic solutions to the Kohn-Sham problem. Notably, to improve the conditioning, we orthogonalize the enrichment functions with respect to the classical FE basis, without sacrificing the locality of the resultant basis. In addition to improved conditioning, this orthogonalization procedure also renders the overlap matrix block-diagonal, greatly simplifying its inversion. Subsequently, we use a Chebyshev polynomial based filtering technique to efficiently compute the occupied eigenspace in each self-consistent field iteration. We demonstrate the accuracy and efficiency of the proposed approach on periodic unit-cells and supercells. The benchmark studies show a staggering $130\times$ speedup of the orthogonalized enriched FE basis over the classical FE basis. We also present a comparison of the orthogonalized enriched FE basis with the LAPW+lo basis, both in terms of accuracy and efficiency. Notably, we demonstrate that the orthogonalized enriched FE basis can handle large system sizes of $\sim$10,000 electrons.
Εφαρμογή της μεθόδου PBL σε ένα CSCL περιβάλλον για την διεπιστημονική προσέγγιση των Μαθηματικών στη Δευτεροβάθμια Εκπαίδευση
Creators: name: Λινάρδος, Ιωάννης
Publisher: name: Πανεπιστήμιο Πειραιώς
Year: 2020
Subjects: subject: PBL
subject: CSCL
subject: Interdisciplinary approach
subject: Εκπαίδευση
subject: Μαθηματικά
subject: MoodleCloud platform

description: Η PBL (Problem Based Learning) είναι μια εκπαιδευτική στρατηγική η οποία εφαρμόστηκε αρχικά στον τομέα της ιατρικής και έπειτα επεκτάθηκε και σε πολλούς άλλους επιστημονικούς κλάδους. Είναι μια τεχνική μάθησης με την οποία οι μαθητές αποκτούν απαραίτητες δεξιότητες όπως η κριτική σκέψη, η συνεργασία ή η επίλυση ενός προβλήματος. Για τον λόγο αυτό, πολλοί εκπαιδευτικοί στον τομέα των μαθηματικών που επιθυμούν να βελτιώσουν την επίδοση των μαθητών, εφαρμόζουν την μέθοδο αυτή η οποία προσφέρει υψηλή βελτίωση. Ως αποτέλεσμα αυτού, κρίνεται αναγκαία η περαιτέρω έρευνα έτσι ώστε να ελεγχθεί κατά πόσο η μέθοδος αυτή μπορεί να επιφέρει θετικά αποτελέσματα στην διαδικασία επίλυσης ενός προβλήματος με υψηλό βαθμό δυσκολίας το οποίο απαιτεί πέρα από τις γνώσεις των μαθηματικών και γνώσεις φυσικής για την επιτυχημένη επίλυσή του. Η παρούσα εργασία υλοποιεί ένα σενάριο βασισμένο στις βασικές αρχές της PBL και της συνεργατικής στρατηγικής Think-Pair-Share σε ένα τεχνολογικά υποστηριζόμενο περιβάλλον MoodleCloud με σκοπό την ενίσχυση της συνεργασίας και της επίλυσης προβλήματος, καθώς και την αποτροπή απόκτησης επιφανειακών γνώσεων σε μαθητές Β’ Γυμνασίου. Ο σκοπός της έρευνας είναι η κατανόηση των μαθηματικών πάνω σε μία συγκεκριμένη ενότητα, εξισώσεις πρώτου βαθμού, με παράλληλη συσχέτιση των μαθηματικών με την φυσική, παρέχοντας έτσι την δυνατότητα κατανόησης της σπουδαιότητάς τους, ενώ ταυτόχρονα αναπτύσσονται σημαντικές δεξιότητες. Συνοψίζοντας τα αποτελέσματα της μελέτης μας, η χρήση ενός σεναρίου το οποίο βασίζεται στις αρχές του PBL μέσα σε ένα τεχνολογικά υποστηριζόμενο περιβάλλον ενισχύει τις δεξιότητες των μαθητών ως προς την συνεργασία, την επίλυση προβλήματος και την υπευθυνότητα. Επίσης, ο συνδυασμός των μαθηματικών και της φυσικής έγινε επιτυχημένα και οι μαθητευόμενοι αξιολογούν θετικά την βελτίωσή τους κατά την διάρκεια την εκπαίδευσης.
Suppression of low-energy Andreev states by a supercurrent in YBa_2Cu_3O_7-delta
Creators: name: Ngai, J.
name: Morales, P.
name: Wei, J. Y. T.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We report a coherence-length scale phenomenon related to how the high-Tc order parameter (OP) evolves under a directly-applied supercurrent. Scanning tunneling spectroscopy was performed on current-carrying YBa_2Cu_3O_7-delta thin-film strips at 4.2K. At current levels well below the theoretical depairing limit, the low-energy Andreev states are suppressed by the supercurrent, while the gap-like structures remain unchanged. We rule out the likelihood of various extrinsic effects, and propose instead a model based on phase fluctuations in the d-wave BTK formalism to explain the suppression. Our results suggest that a supercurrent could weaken the local phase coherence while preserving the pairing amplitude. Other possible scenarios which may cause the observed phenomenon are also discussed.
description: 6 pages, 4 figures, to appear in Physical Review B
Beckmann, Joachim: Kirchliches Jahrbuch für die evangelische Kirche in deutschland 1966
Creators: name: Kg.
Publisher: name: Ökumenische Rundschau
Year: 2025

description: Ökumenische Rundschau, Bd. 18 Nr. 2 (1969): Ökumenische Rundschau, Band 18, Heft 2
Δεδομένα και προκλήσεις στην ενέργεια και ασφάλεια του Αρκτικού Κύκλου
Creators: name: Αλμυράντη, Βασιλική-Ελένη
Publisher: name: Πανεπιστήμιο Πειραιώς
Year: 2020
Subjects: subject: Αρκτικός κύκλος
subject: Ενέργεια
subject: Νομικό καθεστώς στην Αρκτική
subject: Ζητήματα ασφαλείας

description: Ο Αρκτικός Κύκλος αποτελεί ένα από τα τρέχοντα ζητήματα της σύγχρονης εποχής, όπου σύμφωνα με τις μελέτες και τις έρευνες των επιστημόνων οι εξελίξεις στην περιοχή, πρόκειται να επηρεάσουν σημαντικά ολόκληρο τον κόσμο. Οι ραγδαίες περιβαλλοντικές αλλαγές, όπως είναι η κλιματική αλλαγή, έχουν αρχίσει ήδη να επιδρούν στην περιοχή της Αρκτικής, αυξάνοντας τη γεωπολιτική της σημασία. Οι εξελίξεις αυτές για κάποιους είναι θετικότερες, ενώ σε άλλους έχουν αρνητική επίδραση. Ιδιαιτέρως, το λιώσιμο των πάγων φέρνει στην επιφάνεια νέες πηγές ενέργειας προσελκύοντας όλο και περισσότερο το ενδιαφέρον τόσο των γειτονικών κρατών, όσο και διεθνών δρώντων. Στόχος της παρούσας εργασίας είναι, αρχικά, να σκιαγραφήσει την ευρύτερη περιοχή της Αρκτικής και να θέσει το νομικό πλαίσιο του Δικαίου της Θάλασσας σε σχέση με τον Αρκτικό Ωκεανό. Ιδιαίτερη αναφορά γίνεται στο Αρκτικό Συμβούλιο, καθώς αποτελεί το ανώτατο φόρουμ συνεργασίας μεταξύ των οκτώ αρκτικών κρατών. Εν συνεχεία, παρουσιάζονται τα κυριότερα ζητήματα που απασχολούν τους κύριους δρώντες της περιοχής και τα οποία εστιάζονται σε θέματα ενέργειας και ασφάλειας. Τέλος, η Αρκτική έχει μετατραπεί σε «μήλον της Έριδος» και οι προκλήσεις που έχει να αντιμετωπίσει είναι πολλές. Καθώς η γεωπολιτική της αξία αυξάνεται, τα κράτη δείχνουν όλο και μεγαλύτερο ενδιαφέρον, ώστε να αποκτήσουν το δικό τους μερίδιο στην περιοχή.
Hausdorff moments, Hardy spaces and power series
Creators: name: De Micheli, Enrico
name: Viano, Giovanni Alberto
Publisher: name: arXiv
Year: 2005
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: Complex Variables (math.CV)
subject: FOS: Mathematics
subject: 30B10; 30E05

description: In this paper we consider power and trigonometric series whose coefficients are supposed to satisfy the Hausdorff conditions, which play a relevant role in the moment problem theory. We prove that these series converge to functions analytic in cut domains. We are then able to reconstruct the jump functions across the cuts from the coefficients of the series expansions by the use of the Pollaczek polynomials. We can thus furnish a solution for a class of Cauchy integral equations.
description: 17 pages, 2 Postscript figures
Retinol-binding protein 4 and its potential roles in hypercholesterolemia revealed by proteomics
Creators: name: Jugnam-Ang, Watcharapong
name: Pannengpetch, Supitcha
name: Isarankura-Na-Ayudhya, Patcharee
name: Thippakorn, Chadinee
name: Isarankura-Na-Ayudhya, Chartchalerm
name: Lawung, Ratana
name: Prachayasittikul, Virapong
Publisher: name: Technische Universität Dortmund
Year: 2015
Subjects: subject: hypercholesterolemia
subject: proteomics
subject: retinol-binding protein
subject: inflammation
subject: 610

description: Effects of hypercholesterolemia on alterations of serum proteins have not been fully elucidated. Herein, using two-dimensional gel electrophoresis (2-DE) in conjunction with LC-MS searching has successfully been carried out to investigate the change of protein expression profiles as consequences of raised blood cholesterol at different levels (normal group: total cholesterol < 200 mg/dL; borderline high group: total cholesterol 200-239 mg/dL; and high group: total cholesterol ≥ 240 mg/dL) (n = 45). Results revealed that down-regulation of retinol-binding protein 4 (RBP4) (-2.26 fold), transthyretin (-1.25 fold) and gelsolin (-1.47 fold) was observed in the high group. Meanwhile, the other proteins such as haptoglobin, complement factor B and CD5 antigen-like protein were upregulated upto +3.24, +1.96 and +2.04 fold, respectively. Confirmation by Western blotting revealed a significant reduction of RBP4 (approximately 50 %) in individual samples derived from the high group. Presumptive conclusion can be drawn that down-regulation of RBP4 might be attributable to the inflammation of adipocytes caused by the release of proinflammatory cytokines (e.g. tumor necrosis factor α and interleukin-1β) from adipose tissues. Moreover, the decrease of transthyretin might also be taken into accounts since it is known that the transthyretin usually forms complex with RBP4 to prevent glomerular filtration and excretion through the kidney. The suppressing effect on RBP4 should be potentiated by the increase of complement factor B and CD5 antigen-like protein, which rendered the adipose tissues to overwhelm the liberation of RBP4 to blood circulation by metabolic and inflammatory processes. Such inflammation could further modulate the induction of cytokine release (e.g. IL-6 and IL-1β), resulting in the synthesis of acute phase protein, in particular, haptoglobin and Creactive proteins from hepatocytes. However, the mechanism of gelsolin reduction remains unclear. Among these differentially expressed proteins, the RBP4 has been proposed as a major linkage between hypercholesterolemia, adipose tissues, liver and kidney, which is believed to be a potential biomarker for metabolic and cardiovascular disorders associated with dyslipidemia in the future.
description: EXCLI Journal;Vol. 14, 2015
Superstatistics in random matrix theory
Creators: name: Abul-Magd, A. Y.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Using the superstatistics method, we propose an extension of the random matrix theory to cover systems with mixed regular-chaotic dynamics. Unlike most of the other works in this direction, the ensembles of the proposed approach are basis invariant but the matrix elements are not statistically independent. Spectral characteristics of the mixed systems are expressed by averaging the corresponding quantities in the standard random-matrix theory over the fluctuations of the inverse variance of the matrix elements. We obtain analytical expressions for the level density and the nearest-neighbor-spacing distributions for four different inverse-variance distributions. The resulting expressions agree with each others for small departures from chaos, measured by an effective non-extensivity parameter. Our results suggest, among other things, that superstatistics is suited only for the initial stage of transition from chaos to regularity.
description: 15 pages, 5 figures