cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Spin polarization of $Λ$ hyperons in $e^+e^-\toΛ\barΛ$ at BESIII
Creators: name: Li, Cui
name: Schoenning, Karin
Publisher: name: arXiv
Year: 2019
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The BESIII collaboration here reports the first observation of polarized $Λ$ and $\barΛ$ hyperons produced in two different processes: i) the resonant $e^+e^- \to J/ψ\toΛ\barΛ$, using a data sample of 1.31 $\times$ 10$^9$ $J/ψ$ events and ii) the non-resonant $e^+e^-\to γ^* \to Λ\barΛ$, using a 66.9 pb$^{-1}$ data sample collected at $\sqrt{s} =$ 2.396 GeV. In $e^+e^-\to J/ψ\toΛ\barΛ$, the phase between the electric and the magnetic amplitude is measured for the first time to be $42.3^{\mathrm{o}} \pm 0.6^{\mathrm{o}} \pm 0.5^{\mathrm{o}}$. The multi-dimensional analysis enables a model-independent measurement of the decay parameters for $Λ\to pπ^-$ ($α_-$), $\barΛ\to\bar{p}π^+$ ($α_+$) and $\barΛ\to\bar{n}π^0$ ($\barα_0$). The obtained value $α_-=0.750\pm0.009\pm0.004$ differs with ~5$σ$ from the PDG value. This value, together with the measurement $α_+=-0.758\pm0.010\pm0.007$ allow for the most precise test of CP violation in $Λ$ decays so far: $A_{CP} = (α_- + α_+)/(α_- - α_+)$ of $-0.006\pm0.012\pm0.007$. The decay asymmetry $\barα_0 = -0.692\pm0.016\pm0.006$ is measured for the first time. The $e^+e^- \to Λ\barΛ$ reaction at $\sqrt{s} =$ 2.396 GeV enables a first complete measurement of the time-like electric and magnetic form factor of any baryon, of the modulus of the ratio $R=|G_E/G_M|$ and of the relative phase $ΔΦ=Φ_E-Φ_M$. With the decay asymmetry parameters from the $J/ψ$ data, the obtained values are $R=0.96\pm0.14\pm0.02$ and $ΔΦ= 37^{\mathrm{o}} \pm 12^{\mathrm{o}} \pm 6^{\mathrm{o}}$. In addition, the cross section has been measured with unprecedented precision to be $σ= 119.0\pm 5.3\pm5.1$ pb, which corresponds to an effective form factor of $|G|=0.123 \pm 0.003 \pm 0.003$.
description: 1 Talk at BEACH 2018
Computational identification and antifungal bioassay reveals phytosterols as potential inhibitor of Alternaria arborescens
Creators: name: Prassan Choudhary
name: Hillol Chakdar
name: Singh, Arjun
name: Kumar, Sunil
name: Singh, Sanjeev Kumar
name: Murali Aarthy
name: Goswami, Sanjay Kumar
name: Srivastava, Alok Kumar
name: Saxena, Anil Kumar
Publisher: name: Taylor & Francis
Year: 2019
Subjects: subject: Biochemistry
subject: Pharmacology
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: Ecology
subject: FOS: Biological sciences
subject: 69999 Biological Sciences not elsewhere classified

description: Alternaria arborescens is a major pathogen for crops like tomato, tangerine etc. and its control is mostly dependent on the application of chemical agents. Plants as sources of natural products are very attractive option for developing eco-friendly and natural antifungal agents. In the present study, we modeled 3D structure of Chorismate Synthase (AaCS) enzyme from A. arborescens. Docking studies of phytosterols viz. γ-sitosterol and β-sitosterol with CS showed them to be potential inhibitor of CS. To explore the stability and conformational flexibility of all the AaCS complex systems, molecular dynamics simulations (MD) were performed. None of the putative inhibitors as well as β- and γ-sitosterol showed interaction with the FMNH2 binding pocket of the tomato chorismate synthase (major host of A. arborescens) indicating their suitability as antifungal compounds inhibiting the shikimate pathway without causing any harm to the host. An in vivo antifungal bioassay showed a significant reduction in fungal growth in the presence of β-sitosterol (500ppm) which resulted in ∼23% and ∼17% reduction in fungal fresh and dry weight respectively at eight days after inoculation. This study provides experimental evidence establishing natural sterols like β-sitosterol can be useful in curbing A. arborescens damage in an eco-friendly manner.
Antiferromagnetic Order of the Ru and Gd in Superconducting RuSr2GdCu2O8
Creators: name: Lynn, J. W.
name: Keimer, B.
name: Ulrich, C.
name: Bernhard, C.
name: Tallon, J. L.
Publisher: name: arXiv
Year: 2000
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Neutron diffraction has been used to study the magnetic order in RuSr{2}GdCu2O8. The Ru moments order antiferromagnetically at T{N}=136(2)K, coincident with the previously reported onset of ferromagnetism. Neighboring spins are antiparallel in all three directions, with a low T moment of 1.18(6) mu {B} along the c-axis. Our measurements put an upper limit of ~0.1 mu{B} to any net zero-field moment, with fields exceeding ~0.4T needed to induce a measurable magnetization. The Gd ions order independently at T{N}=2.50(2)K with the same spin configuration. PACS numbers: 74.72.Jt, 75.25.+z, 74.25.Ha, 75.30.Kz
description: Four pages, Latex, 5 eps figures
The Unwanted Sharing Economy: An Analysis of Cookie Syncing and User Transparency under GDPR
Creators: name: Urban, Tobias
name: Tatang, Dennis
name: Degeling, Martin
name: Holz, Thorsten
name: Pohlmann, Norbert
Publisher: name: arXiv
Year: 2018
Subjects: subject: Cryptography and Security (cs.CR)
subject: FOS: Computer and information sciences

description: The European General Data Protection Regulation (GDPR), which went into effect in May 2018, leads to important changes in this area: companies are now required to ask for users' consent before collecting and sharing personal data and by law users now have the right to gain access to the personal information collected about them. In this paper, we study and evaluate the effect of the GDPR on the online advertising ecosystem. In a first step, we measure the impact of the legislation on the connections (regarding cookie syncing) between third-parties and show that the general structure how the entities are arranged is not affected by the GDPR. However, we find that the new regulation has a statistically significant impact on the number of connections, which shrinks by around 40%. Furthermore, we analyze the right to data portability by evaluating the subject access right process of popular companies in this ecosystem and observe differences between the processes implemented by the companies and how they interpret the new legislation. We exercised our right of access under GDPR with 36 companies that had tracked us online. Although 32 companies (89%) we inquired replied within the period defined by law, only 21 (58%) finished the process by the deadline set in the GDPR. Our work has implications regarding the implementation of privacy law as well as what online tracking companies should do to be more compliant with the new regulation.
Pulp colour and pigment composition have no genetic correlation with seed hardness in guava (Psidium guajava L.)
Creators: name: Bishnoi, Pooja
name: Thakre, Madhubala
name: Maurya, Poonam
name: Jagga, Shubham
name: Gangappa, Nayan Deepak
name: Nagaraja, Arumugam
name: Verma, Mahendra Kumar
name: Krishnan, S. Gopala
name: Varghese, Eldho
name: Sevanthi, Amitha Mithra
Publisher: name: Taylor & Francis
Year: 2024
Subjects: subject: Biophysics
subject: Medicine
subject: Environmental Sciences not elsewhere classified
subject: Ecology
subject: FOS: Biological sciences
subject: Biological Sciences not elsewhere classified
subject: Science Policy
subject: Plant Biology

description: Guava (Psidium guajava L.) is a ‘super fruit’, also known as the ‘apple of the tropics’. This study was conducted on five guava parents and their 42 F1s. They were studied for their pigment composition (lycopene, total anthocyanin, and total carotenoid content) and seed-based parameters (seed hardness, index, length, and width). Transgressive segregation was present for pigment composition, seed index, and seed hardness. For lycopene and total carotenoids content, F1s had maximum values. However, for total anthocyanins content, only guava parent BG had a considerably higher value (8.881 mg/100 g) and had a purple pulp colour. Most F1s belonged to the soft seed category (28 F1s out of 42) and intermediate seed index 1–1.5 g (24 F1s out of 42). The findings indicate that, in guava, pulp colour is not correlated with seed hardness. However, a significantly positive correlation between seed hardness and other seed-related parameters (namely seed index, seed length, and seed width) indicates that a bigger seed size is associated with seed hardness.
Consciousness as neurological phenomenon
Creators: name: Timalsina, Staneshwar
Publisher: name: Zenodo
Year: 2024
Subjects: Spanda
shakti
Kula
yantra
Īśāna
saivadvaita
Chandi
Shiva
sthaneshwar timalsina
trika
Tantra
Camunda
Kali
Durga
mahadeva
Vasugupta
Saundaryalahari
vedanta
vimarsha-foundation
Tantric philosophy
anava upaya
Devi Mahatmya
sarvamnaya
Sarvamnaya
Sadāśiva
shakta upāya
sarvamnaya-oral-tradition-archive
advaita vedanta
agama
Shaiva
amnaya
Tripurasundari
tantraloka
tripura
Bhairava
Abhinavagupta
krama
Divine Mother
Kubjika
shambhava
Kaula
timalsina
Mahakali
consciousness
Mālinīvijayottaratantra
Tripura Rahasya
Shiva Sutra
Guhyakālī
Kashmir Shaivism

description: This video is an introductory discussion on Tantra led by Ācārya Dr. Sthaneshwar Timalsina. Dr. Timalsina discusses Consciousness as neurological phenomenon

***** Thank you for watching *****

Remember to like this video and subscribe to our channel.

**** Follow us *****
X-Twitter: https://twitter.com/vimarshafdn
Facebook: https://www.facebook.com/vimarshafoundation
Instagram:https://www.instagram.com/vimarshafoundation/

**** Courses *****

Courses offered by Acharya Dr. Sthaneshwar Timalsina
Introduction to Sarvāmnāya Tantra
https://www.vimarshafoundation.org/challenge-page/introtosarvamnaya
Yoga Vāsiṣṭha
https://www.vimarshafoundation.org/challenge-page/yogavasistha
Foundational Śaivism
https://www.vimarshafoundation.org/challenge-page/foundationalsaivism
See more: https://www.vimarshafoundation.org/courses

**** Help us grow our foundation ******
https://www.vimarshafoundation.org/supportus

**** About Vimarsha Foundation *****
Vimarsha Foundation is a modern school (gurukula) for teaching and reflecting on the ancient wisdom of r̥ṣis and siddhas. Through Vimarsha Foundation, a non-profit organization, Acharya Sthaneshwar teaches shastra and sādhanā to students of all backgrounds. The Vimarsha Foundation hosts free semester length courses on classic texts of the Tantric Tradition and offers many more free video and written teachings. Visit our website to learn more: https://www.vimarshafoundation.org/

**** Acharya Dr. Sthaneshwar Timalsina ****
Acharya Dr. Sthaneshwar Timalsina is an esteemed traditionally consecrated teacher of Shaiva-Shakta Hindu Tantra. He is also the Endowed Chair of Indic Studies in New York, U.S.A. at Stony Brook University's College of Arts & Sciences in the Department of Asian & Asian-American Studies. Acharya Sthaneshwar founded Vimarsha Foundation as a modern school (gurukula) for teaching and reflecting on the ancient wisdom of r̥ṣis and siddhas. Through Vimarsha Foundation, a non-profit organization, Acharya Sthaneshwar teaches shastra and sādhanā to students of all backgrounds. The Vimarsha Foundation hosts free semester length courses on classic texts of the Tantric Tradition and offers many more free video and written teachings.

Original YouTube video: https://www.youtube.com/watch?v=VNWpnpFvxn8

This presentation is part of the Sarvāmnāya Oral Tradition Archive.
Vimarsha Foundation. (2025). The Sarvāmnāya Oral Tradition Archive [Data set]. Zenodo. https://doi.org/10.5281/zenodo.15188107
Time-dependent linear response of an inhomogeneous Bose superfluid: Microscopic theory and connection to current-density functional theory
Creators: name: Chiofalo, M. L.
name: Minguzzi, A.
name: Tosi, M. P.
Publisher: name: arXiv
Year: 1998
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: The dynamics of a confined fluid of Bose atoms is treated within the linear response regime, with a view to establishing a current-density functional formalism for an inhomogeneous superfluid state. After evaluating in full detail a simplified case of an external coupling to the density and phase of the condensate, the theory is extended to include the coupling to the total current density. The Kohn-Sham response functions of the condensate and all the exchange-correlation kernels for the superfluid are introduced from the microscopic equations of motion and are expressed in a physically transparent way through functional derivatives of correlation functions. A microscopic formula for the superfluid density is derived and used to introduce a generalized hydrodynamic approach for a weakly inhomogeneous two-fluid model in isothermal conditions. Local-density expressions are thereby derived for the velocities of first and second sound in the weakly inhomogeneous superfluid and for visco-elastic functions describing the transition from the hydrodynamic to the collisionless regime. Landau's hydrodynamic theory and known results in Green's functions language are recovered in the limiting case of a homogeneous superfluid.
description: 25 pages, no figures, Postscript file
Μεθοδολογικές προσεγγίσεις των εκπαιδευτικών της πρωτοβάθμιας και της δευτεροβάθμιας εκπαίδευσης κατά τη διδασκαλία της σχολικής ιστορίας : μια συγκριτική μελέτη.
Creators: name: Θώδης, Γεώργιος
name: Μουταβελής, Αδριανός
Publisher: name: Παιδαγωγική Επιθεώρηση
Year: 2015

description: The present research is aimed at the examination of the ways of thinking and apprehension of educators concerning the method of teaching History at Primary school, High school and Lycee. The educators answered to 51 statements-propositions about methods concerning History lesson in an improvised scale. These teaching methods had direct relationship to the afore¬mentioned epistemologic theories about teaching and learning. There was significant correlation among these epistemologic theories and various demographic factors, such as the years of work, the age and the education. There was also correlation between the theories that were applied by the educators and the class they were teaching; the «personal» theory, which influenced the selection of teaching aims by the educators, emerged dis¬tinctly.
description: Παιδαγωγική Επιθεώρηση, Vol. 53 (2012)
Electronic supplementary information from Effects of landscape complexity on pollinators are moderated by pollinators' association with mass-flowering crops
Creators: name: Fijen, Thijs P. M.
name: Scheper, Jeroen A.
name: Bastiaen Boekelo
name: Raemakers, Ivo
name: Kleijn, David
Publisher: name: The Royal Society
Year: 2019
Subjects: subject: Ecology
subject: FOS: Biological sciences

description: Results of analyses using alternative classifications for dominant crop pollinators.
Retina U-Net: Embarrassingly Simple Exploitation of Segmentation Supervision for Medical Object Detection
Creators: name: Jaeger, Paul F.
name: Kohl, Simon A. A.
name: Bickelhaupt, Sebastian
name: Isensee, Fabian
name: Kuder, Tristan Anselm
name: Schlemmer, Heinz-Peter
name: Maier-Hein, Klaus H.
Publisher: name: arXiv
Year: 2018
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: The task of localizing and categorizing objects in medical images often remains formulated as a semantic segmentation problem. This approach, however, only indirectly solves the coarse localization task by predicting pixel-level scores, requiring ad-hoc heuristics when mapping back to object-level scores. State-of-the-art object detectors on the other hand, allow for individual object scoring in an end-to-end fashion, while ironically trading in the ability to exploit the full pixel-wise supervision signal. This can be particularly disadvantageous in the setting of medical image analysis, where data sets are notoriously small. In this paper, we propose Retina U-Net, a simple architecture, which naturally fuses the Retina Net one-stage detector with the U-Net architecture widely used for semantic segmentation in medical images. The proposed architecture recaptures discarded supervision signals by complementing object detection with an auxiliary task in the form of semantic segmentation without introducing the additional complexity of previously proposed two-stage detectors. We evaluate the importance of full segmentation supervision on two medical data sets, provide an in-depth analysis on a series of toy experiments and show how the corresponding performance gain grows in the limit of small data sets. Retina U-Net yields strong detection performance only reached by its more complex two-staged counterparts. Our framework including all methods implemented for operation on 2D and 3D images is available at github.com/pfjaeger/medicaldetectiontoolkit.
Η αξιοποίηση των λαϊκών μύθων στην προώθηση της διαπολιτισμικής εκπαίδευσης.
Creators: name: Ερμογένους, Καίτη
name: Παντέλα, Σούλα
Publisher: name: Παιδαγωγική Επιθεώρηση
Year: 2015

description: The purpose of the present research is to investigate whether teaching with the use of folktales can contribute to the promotion of Intercultural Educa¬tion. Data were collected following qualitative research methods (observa¬tion of teaching of two Cyprus folktales, interviews with pupils and inter¬views with two teachers, who observed the teaching) from two 4th grade classes of two primary schools in Nicosia, Cyprus. The results of the re¬search showed that the children of the two classes got stereotypes against black race. They also showed that appropriate teaching of folktales can help pupils change their attitude and raises participation and critical reflection.
description: Παιδαγωγική Επιθεώρηση, Vol. 53 (2012)
Pourouma bicolor subsp. digitata C. C. Berg & Heusden
Creators: name: Molino, Jean-François
name: Sabatier, Daniel
name: Grenand, Pierre
name: Engel, Julien
name: Frame, Dawn
name: Delprete, Piero G.
name: Fleury, Marie
name: Odonne, Guillaume
name: Davy, Damien
name: Lucas, Eve J.
name: Martin, Claire A.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Rosales
Urticaceae
Pourouma
Pourouma bicolor
Pourouma bicolor subsp. digitata (trécul) c.c.berg & heusden

description: [1750] Pourouma bicolor subsp. digitata (Trécul) C.C.Berg & Heusden
 Proc. Kon. Ned. Akad. Wetensch. C 91 (2): 106 (Berg & Heusden 1988). — Pourouma digitata Trécul, Ann. Sci. Nat., Bot. sér. 3, 8: 106 (Trécul 1847).
VERNACULAR NAMES. — Pa: kwem, kwem-purubumna • Wp: a’ɨlea, kulumã tololo • Cr: mal-bwa-kannon • Br: imbaúbarana, mapatirana.
 HERBARIUM DATA (FG). — 31 collections at CAY. Sel. exs.: P.A. Poiteau s.n. (lecto-, P[P00753657], designated by Berg & van Heusden [Berg et al. 1990: 137]; isolecto-, B[B100248462]).
INVENTORY DATA (FG). — 39 trees in 22 plots; Fmax = 1.2 %; dbhinv = 46.9 cm.
description: Published as part of Molino, Jean-François, Sabatier, Daniel, Grenand, Pierre, Engel, Julien, Frame, Dawn, Delprete, Piero G., Fleury, Marie, Odonne, Guillaume, Davy, Damien, Lucas, Eve J. & Martin, Claire A., 2022, An annotated checklist of the tree species of French Guiana, including vernacular nomenclature, pp. 345-903 in Adansonia (3) (3) 44 (26) on page 714, DOI: 10.5252/adansonia2022v44a26, http://zenodo.org/record/7458777
Biological Evolution and Statistical Physics
Creators: name: Drossel, Barbara
Publisher: name: arXiv
Year: 2001
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: Quantitative Biology (q-bio)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: This review is an introduction to theoretical models and mathematical calculations for biological evolution, aimed at physicists. The methods in the field are naturally very similar to those used in statistical physics, although the majority of publications appeared in biology journals. The review has three parts, which can be read independently. The first part deals with evolution in fitness landscapes and includes Fisher's theorem, adaptive walks, quasispecies models, effects of finite population sizes, and neutral evolution. The second part studies models of coevolution, including evolutionary game theory, kin selection, group selection, sexual selection, speciation, and coevolution of hosts and parasites. The third part discusses models for networks of interacting species and their extinction avalanches. Throughout the review, attention is paid to giving the necessary biological information, and to pointing out the assumptions underlying the models, and their limits of validity.
description: Review article accepted for publication in Advances in Physics. 106 pages
UMUMIY PЕDАGОGIKА DАRSLАRIDА RАQАMLI TЕHNОLОGIYАLАR VА SUN'IY INTЕLЕKTDАN FОYDАLАNISH MЕTОDLАRI
Creators: name: Nо'mоnxоnоvа, Muаttаrxоn
Publisher: name: Zenodo
Year: 2025

description: Rаqаmli tеxnоlоgiyаlаr vа sun’iy intеllеktning (АI) umumiy pеdаgоgikа dаrslаrigа intеgrаtsiyаlаshuvi аn’аnаviy о‘qitish usullаrini sеzilаrli dаrаjаdа о‘zgаrtirdi. Rаqаmli vоsitаlаr vа sun'iy intеllеktgа аsоslаngаn plаtfоrmаlаr talabalаrning fаоlligini vа pеdаgоgik sаmаrаdоrligini оshirаdigаn shаxsiylаshtirilgаn о'rgаnish tаjribаsi, аvtоmаtlаshtirilgаn bаhоlаsh vа intеrаktiv kоntеntni tаklif еtаdi. Ushbu mаqоlа rаqаmli tеxnоlоgiyаlаr vа АIni pеdаgоgikаgа kiritishning turli usullаrini, jumlаdаn аdаptiv tаʼlim tizimlаri, virtuаl sinflаr, sunʼiy intеllеkt аsоsidаgi rеpеtitоrlik vа оʻquvсhilаr tаrаqqiyоtini kuzаtish uсhun mаʼlumоtlаr tаhlilini оʻrgаnаdi. Zаmоnаviy tа'lim tаdqiqоtсhilаrining fikrlаrigа tаyаngаn hоldа, tаdqiqоt umumiy pеdаgоgikа dаrslаridа ushbu tеxnоlоgiyаlаrni sаmаrаli intеgrаtsiyаlаshning аfzаlliklаri, muаmmоlаri vа ilg'оr tаjribаlаrini tа'kidlаydi.
Direct Measurement of the Top Quark Mass
Creators: name: D0 Collaboration
name: Abachi, S.
Publisher: name: arXiv
Year: 1997
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We measure the top quark mass m_t using t tbar pairs produced in the D0 detector by root(s) = 1.8 TeV p pbar collisions in a 125 pb^-1 exposure at the Fermilab Tevatron. We make a two constraint fit to m_t in t tbar --> b W^+ bbar W^- final states with one W decaying to q qbar and the other to e nu or mu nu. Events are binned in fit mass versus a measure of probability for events to be signal rather than background. Likelihood fits to the data yield m_t = 173.3 +- 5.6 (stat) +- 6.2 (syst) GeV/c^2.
description: 11 pages with 3 encapsulated PostScript figures and 1 encapsulated PostScript table included in the body of the article
Compaction of Rods: Relaxation and Ordering in Vibrated, Anisotropic Granular Material
Creators: name: Villarruel, Fernando X.
name: Lauderdale, Benjamin E.
name: Mueth, Daniel M.
name: Jaeger, Henrich M.
Publisher: name: arXiv
Year: 2000
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We report on experiments to measure the temporal and spatial evolution of packing arrangements of anisotropic, cylindrical granular material, using high-resolution capacitive monitoring. In these experiments, the particle configurations start from an initially disordered, low-packing-fraction state and under vertical vibrations evolve to a dense, highly ordered, nematic state in which the long particle axes align with the vertical tube walls. We find that the orientational ordering process is reflected in a characteristic, steep rise in the local packing fraction. At any given height inside the packing, the ordering is initiated at the container walls and proceeds inward. We explore the evolution of the local as well as the height-averaged packing fraction as a function of vibration parameters and compare our results to relaxation experiments conducted on spherically shaped granular materials.
description: 9 pages incl. 7 figures
Pourouma guianensis Aubl.
Creators: name: Molino, Jean-François
name: Sabatier, Daniel
name: Grenand, Pierre
name: Engel, Julien
name: Frame, Dawn
name: Delprete, Piero G.
name: Fleury, Marie
name: Odonne, Guillaume
name: Davy, Damien
name: Lucas, Eve J.
name: Martin, Claire A.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Rosales
Urticaceae
Pourouma
Pourouma guianensis

description: [1751] Pourouma guianensis Aubl.
 Hist. Pl. Guiane 2: 892 [Jun.-Dec. 1775] (Aublet 1775).
 Pourouma palmata Poepp. & Endl., Nova genera ac species plantarum [Poeppig & Endlicher] 2: 29 [Jan.-Sep. 1838] (Poeppig & Endlicher 1838).
 Pourouma acutiflora Trécul, Ann. Sci. Nat., Bot. sér. 3, 8: 105 (Trécul 1847).
 Pourouma cinerascens Mart. ex Miq., Fl. Bras. [Martius] 4 (1): 125 [1 Dec. 1853] (Miquel 1853).
 Pourouma heterophylla Mart. ex Miq., Fl. Bras. [Martius] 4 (1): 125 [1 Dec. 1853] (Miquel 1853).
 Pourouma fuliginea Miq., Fl. Bras. [Martius] 4 (1): 129 [1 Dec. 1853] (Miquel 1853).
 Pourouma scabra Rusby, Bull. New York Bot. Gard. 6 (22): 498 [30 Nov. 1910] (Rusby 1910).
 Pourouma radula Benoist, Bull. Mus. Natl. Hist. Nat. 28: 320 (Benoist 1922).
 Pourouma subtriloba Rusby, Mem. New York Bot. Gard. 7: 232 (Rusby 1927).
 Pourouma substrigosa Mildbr., Notizbl. Bot. Gart. Berlin-Dahlem 10: 192 [20 Dec. 1927] (Mildbraed 1927).
 Pourouma mildbraediana Standl., Publ. Field Mus. Nat. Hist., Bot. Ser. 17 (2): 183 (Standley 1937).
 NOTE. — Hyperdominant in Amazonia (ter Steege et al. 2020).
VERNACULAR NAMES. — Ka: puluma, yalayala • Wp: kulumã kalate, kulumã sĩ• Cr: mal-bwa-kannon • Br: embaúba-bengué.
 HERBARIUM DATA (FG). — 21 collections at CAY. Sel. exs.: J.B. Aublet s.n. (original material BM[BM000993430]).
INVENTORY DATA (FG). — 28 trees in 14 plots; Fmax <1 %; dbhinv = 38.5 cm.
description: Published as part of Molino, Jean-François, Sabatier, Daniel, Grenand, Pierre, Engel, Julien, Frame, Dawn, Delprete, Piero G., Fleury, Marie, Odonne, Guillaume, Davy, Damien, Lucas, Eve J. & Martin, Claire A., 2022, An annotated checklist of the tree species of French Guiana, including vernacular nomenclature, pp. 345-903 in Adansonia (3) (3) 44 (26) on pages 714-715, DOI: 10.5252/adansonia2022v44a26, http://zenodo.org/record/7458777
Magnetic excitations in charge- ordered NaV2O5
Creators: name: Thalmeier, P.
name: Yaresko, A. N.
Publisher: name: arXiv
Year: 1999
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: An investigation of the spin excitation spectrum of charge ordered (CO) NaV2O5 is presented. We discuss several different exchange models which may be relevant for this compound, namely in- line and zig-zag chain models with weak as well as strong inter- chain coupling and also a ladder model and a CO/MV (mixed valent) model. We put special emphasis on the importance of large additional exchange across the diagonals of V- ladders and the presence of exchange anisotropies on the excitation spectrum. It is shown that the observed splitting of transverse dispersion branches may both be interpreted as anisotropy effect as well as acoustic- optic mode splitting in the weakly coupled chain models. In addition we calculate the field dependence of excitation modes in these models. Furthermore we show that for strong inter- chain coupling, as suggested by recent LDA+U results, an additional high energy optical excitation appears and the spin gap is determined by anisotropies. The most promising CO/MV model predicts a spin wave dispersion perpendicular to the chains which agrees very well with recent results obtained by inelastic neutron scattering.
description: Revtex, 22 pages, 7 postscript figures
Current-density functional theory of time-dependent linear response in quantal fluids: recent progress
Creators: name: Tosi, M. P.
name: Chiofalo, M. L.
name: Minguzzi, A.
name: Nifosi`, R.
Publisher: name: arXiv
Year: 1998
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Vignale and Kohn have recently formulated a local density approximation to the time-dependent linear response of an inhomogeneous electron system in terms of a vector potential for exchange and correlation. The vector potential depends on the induced current density through spectral kernels to be evaluated on the homogeneous electron-gas. After a brief review of their theory, the case of inhomogeneous Bose superfluids is considered, with main focus on dynamic Kohn-Sham equations for the condensate in the linear response regime and on quantal generalized hydrodynamic equations in the weak inhomogeneity limit. We also present the results of calculations of the exchange-correlation spectra in both electron and superfluid boson systems.
description: 12 pages, 2 figures, Postscript file
Supplementary Information from Quantifying dissipation in actomyosin networks
Creators: name: Floyd, Carlos
name: Papoian, Garegin A.
name: Jarzynski, Christopher
Publisher: name: The Royal Society
Year: 2019
Subjects: subject: Biophysics
subject: 60104 Cell Metabolism
subject: FOS: Biological sciences
subject: 60199 Biochemistry and Cell Biology not elsewhere classified
subject: 69999 Biological Sciences not elsewhere classified
subject: Computational Biology

description: This file contains supplementary methodological information, a description of a mean-field model of dissipation resulting from actin filament treadmilling, and supplementary figures.
A six-factor asset pricing model
Creators: name: Roy, Rahul
name: Shijin, Santhakumar
Publisher: name: arXiv
Year: 2018
Subjects: subject: Statistical Finance (q-fin.ST)
subject: FOS: Economics and business

description: The present study introduce the human capital component to the Fama and French five-factor model proposing an equilibrium six-factor asset pricing model. The study employs an aggregate of four sets of portfolios mimicking size and industry with varying dimensions. The first set consists of three set of six portfolios each sorted on size to B/M, size to investment, and size to momentum. The second set comprises of five index portfolios, third, a four-set of twenty-five portfolios each sorted on size to B/M, size to investment, size to profitability, and size to momentum, and the final set constitute thirty industry portfolios. To estimate the parameters of six-factor asset pricing model for the four sets of variant portfolios, we use OLS and Generalized method of moments based robust instrumental variables technique (IVGMM). The results obtained from the relevance, endogeneity, overidentifying restrictions, and the Hausman's specification, tests indicate that the parameter estimates of the six-factor model using IVGMM are robust and performs better than the OLS approach. The human capital component shares equally the predictive power alongside the factors in the framework in explaining the variations in return on portfolios. Furthermore, we assess the t-ratio of the human capital component of each IVGMM estimates of the six-factor asset pricing model for the four sets of variant portfolios. The t-ratio of the human capital of the eighty-three IVGMM estimates are more than 3.00 with reference to the standard proposed by Harvey et al. (2016). This indicates the empirical success of the six-factor asset-pricing model in explaining the variation in asset returns.
Pourouma melinonii Benoist
Creators: name: Molino, Jean-François
name: Sabatier, Daniel
name: Grenand, Pierre
name: Engel, Julien
name: Frame, Dawn
name: Delprete, Piero G.
name: Fleury, Marie
name: Odonne, Guillaume
name: Davy, Damien
name: Lucas, Eve J.
name: Martin, Claire A.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Rosales
Urticaceae
Pourouma
Pourouma melinonii

description: [1752] Pourouma melinonii Benoist
 Bull. Mus. Natl. Hist. Nat. 28: 318 (Benoist 1922).
 Pourouma apaporiensis Cuatrec., Caldasia 7 (34): 297 (Cuatrecasas 1956).
 Pourouma apaporiensis var. macrophylla Cuatrec., Caldasia 7 (34): 298 (Cuatrecasas 1956), “fma. macrophylla Cuatr., var. nov. ”.
VERNACULAR NAMES. — Pa: kwem purubumna • Ka:puluma, yalayala • Te: pulumã • Wp: kule p ɨ, kulumã tololo • Wn: ulumapi • Nt: busi papay • Cr: mal-bwa-kannon • Fr: pourouma • Br: imbaúbada-mata, imbaúbarana, tararanga.
 HERBARIUM DATA (FG). — 35 collections at CAY. Sel. exs.: P.A. Sagot 990, Nov. 1856 (lecto-, P [P06855173], designated by Berg [Berg & Dewolf 1975: 274]; isolecto-, B [B100248451], K [K000512469]).
INVENTORY DATA (FG). — 147 trees in 63 plots; Fmax = 2.1 %; dbhinv = 50.3 cm.
description: Published as part of Molino, Jean-François, Sabatier, Daniel, Grenand, Pierre, Engel, Julien, Frame, Dawn, Delprete, Piero G., Fleury, Marie, Odonne, Guillaume, Davy, Damien, Lucas, Eve J. & Martin, Claire A., 2022, An annotated checklist of the tree species of French Guiana, including vernacular nomenclature, pp. 345-903 in Adansonia (3) (3) 44 (26) on page 715, DOI: 10.5252/adansonia2022v44a26, http://zenodo.org/record/7458777
Description of the method used to calculate the viscosity of the LJ fluid from Cross-over in the dynamics of polymer confined between two liquids of different viscosity
Creators: name: Giunta, Giuliana
name: Carbone, Paola
Publisher: name: The Royal Society
Year: 2019
Subjects: subject: 30699 Physical Chemistry not elsewhere classified
subject: FOS: Chemical sciences
subject: 100799 Nanotechnology not elsewhere classified
subject: FOS: Nanotechnology

description: Using molecular dynamics simulations, we analysed the polymer dynamics of chains of different molecular weights entrapped at the interface between two immiscible liquids. We showed that increasing the viscosity of one of the two liquids the dynamic behaviour of the chain changes from a Zimm-like dynamics typical of dilute polymer solutions, to a Rouse-like dynamics where hydrodynamic interactions are screened. We observed that when the polymer is in contact with a high viscosity liquid, the number of solvent molecules closed to the polymer beads is reduced and ascribed the screening effect to this reduced number of polymer-solvent contacts. For the longest chain simulated, we calculated the distribution of loops length and compared the results with the theoretical distribution developed for solid/liquid interfaces. We showed that the polymer tends to form loops (although flat against the interface) and that the theory works reasonably well also for liquid/liquid interfaces.
Stability of exact solutions of the defocusing nonlinear Schrodinger equation with periodic potential in two dimensions
Creators: name: Deconinck, Bernard
name: Frigyik, Bela A.
name: Kutz, J. Nathan
Publisher: name: arXiv
Year: 2001
Subjects: subject: Condensed Matter (cond-mat)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: The cubic nonlinear Schrodinger equation with repulsive nonlinearity and elliptic function potential in two-dimensions models a repulsive dilute gas Bose--Einstein condensate in a lattice potential. A family of exact stationary solutions is presented and its stability is examined using analytical and numerical methods. All stable trivial-phase solutions are off-set from the zero level. Our results imply that a large number of condensed atoms is sufficient to form a stable, periodic condensate.
description: 12 pages, Latex, High resolution version available at http://www.amath.washington.edu/~kutz/research.html
Verifiable Round-Robin Scheme for Smart Homes
Creators: name: Panwar, Nisha
name: Sharma, Shantanu
name: Wang, Guoxi
name: Mehrotra, Sharad
name: Venkatasubramanian, Nalini
Publisher: name: arXiv
Year: 2019
Subjects: subject: Cryptography and Security (cs.CR)
subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: Advances in sensing, networking, and actuation technologies have resulted in the IoT wave that is expected to revolutionize all aspects of modern society. This paper focuses on the new challenges of privacy that arise in IoT in the context of smart homes. Specifically, the paper focuses on preventing the user's privacy via inferences through channel and in-home device activities. We propose a method for securely scheduling the devices while decoupling the device and channels activities. The proposed solution avoids any attacks that may reveal the coordinated schedule of the devices, and hence, also, assures that inferences that may compromise individual's privacy are not leaked due to device and channel level activities. Our experiments also validate the proposed approach, and consequently, an adversary cannot infer device and channel activities by just observing the network traffic.
description: Accepted in ACM Conference on Data and Application Security and Privacy (CODASPY), 2019. 12 pages
Limit on the Two-Photon Production of the Glueball Candidate $f_{J}(2220)$ at CLEO
Creators: name: CLEO Collaboration
name: Godang, R.
Publisher: name: arXiv
Year: 1997
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We use the CLEO detector at the Cornell electron-positron storage ring, CESR, to search for the two-photon production of the glueball candidate f_J(2220) in its decay to K_s K_s. We present a restrictive upper limit on the product of the two-photon partial width and the K_s K_s branching fraction. We use this limit to calculate a lower limit on the stickiness, which is a measure of the two-gluon coupling relative to the two-photon coupling. This limit on stickiness indicates that the f_J(2220) has substantial glueball content.
description: 9 page postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLNS
Pourouma minor Benoist
Creators: name: Molino, Jean-François
name: Sabatier, Daniel
name: Grenand, Pierre
name: Engel, Julien
name: Frame, Dawn
name: Delprete, Piero G.
name: Fleury, Marie
name: Odonne, Guillaume
name: Davy, Damien
name: Lucas, Eve J.
name: Martin, Claire A.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Rosales
Urticaceae
Pourouma
Pourouma minor

description: [1753] Pourouma minor Benoist
 Bull. Mus. Natl. Hist. Nat. 30: 103 (Benoist 1924).
 Pourouma aurea Mildbr., Notizbl. Bot. Gart. Berlin-Dahlem 10: 418 [1 Dec. 1928] (Mildbraed 1928).
 Pourouma folleata J.F.Macbr., Publ. Field Mus. Nat. Hist., Bot. Ser. 8 (2): 114 (Macbride 1930).
 Pourouma isophlebia Standl., Publ. Field Mus. Nat. Hist., Bot. Ser. 17 (2): 182 (Standley 1937).
 Pourouma subplicata Standl., Publ. Field Mus. Nat. Hist., Bot. Ser. 17 (2): 184 (Standley 1937).
 Pourouma umbellata Standl., Publ. Field Mus. Nat. Hist., Bot. Ser. 17 (2): 185 (Standley 1937).
 Coussapoa emarginata Killip ex J.F.Macbr., Publ. Field Mus. Nat. Hist., Bot. Ser. 13 (2.2): 296 [15 Mar. 1937] (Macbride 1937).
 Pourouma cuatrecasasii Standl., Revista Acad. Colomb. Ci. Exact. 9 (36/37): 339 [May 1956] (Standley 1956).
 Pourouma umbellifera W.C.Burger, Phytologia 26 (6): 430 [11 Oct. 1973] (Burger 1973).
 NOTE. — Hyperdominant in Amazonia (ter Steege et al. 2020). Benoist (1924: 104) cited three collections in the protologue of P. minor: R. Benoist 960, R. Benoist 978, and Wachenheim, 3 e série, 18. Berg & van Heusden (1990: 186) cited for the type “ Benoist 960 (lectotype, P, chosen here)”; their lectotype corresponds to two specimens at P (P00756799 and P00756800). Both are labelled “ Pourouma minor R. Ben. ” by Benoist, but only one of them (P00756800) is labelled “Revised for Flora Neotropica. Pourouma minor Benoist. Lectotype ” by Berg and van Heusden. It is therefore hereafter choosen as the lectotype.
VERNACULAR NAMES. — Pa: kwem-seinõ, kwem-tino • Wp: kulumã sĩ• Cr: mal-bwa-kannon • Br: mapatirana, purumaí, tourém.
 HERBARIUM DATA (FG). — 64 collections at CAY. Sel. exs.: R. Benoist 960 (lecto-, P[P00756800, here designated; isolecto-, P[P00756799]).
INVENTORY DATA (FG). — 250 trees in 51 plots; Fmax = 4.9 %; dbhinv = 45 cm.
description: Published as part of Molino, Jean-François, Sabatier, Daniel, Grenand, Pierre, Engel, Julien, Frame, Dawn, Delprete, Piero G., Fleury, Marie, Odonne, Guillaume, Davy, Damien, Lucas, Eve J. & Martin, Claire A., 2022, An annotated checklist of the tree species of French Guiana, including vernacular nomenclature, pp. 345-903 in Adansonia (3) (3) 44 (26) on page 715, DOI: 10.5252/adansonia2022v44a26, http://zenodo.org/record/7458777
Στρατηγικές κατανόησης κειμένου και μαθησιακή προσέγγιση από παιδιά γυμνασίου με μαθησιακές δυσκολίες.
Creators: name: Αντωνίου, Σταμάτης
name: Πολυχρόνη, Φωτεινή
name: Κοτρώνη, Χριστίνα
Publisher: name: Παιδαγωγική Επιθεώρηση
Year: 2015

description: The aim of the present study was to investigate approaches to learning and strategies for reading comprehension employed by students with LD particu¬larly in humanities courses. The sample consisted of 40 1 students diagnosed with LD and 371 students without LD attending the 1st, 2nd, and 3rd grades of Junior High School. The Study Process Questionnaire and the Questionnaire of Strategies for Text Reading Comprehension were administered to the par¬ticipants. Students with LD reported higher use of a surface approach to learning, lower use of reading comprehension strategies as compared to their average and high performance peers but no significant difference was found betw een the groups in terms of the deep approach to learning. Finally, deep strategies were the strongest predictor of the students’ performance in the literature subject.
description: Παιδαγωγική Επιθεώρηση, Vol. 53 (2012)
Classes of behavior of small-world networks
Creators: name: Amaral, Luis A. Nunes
name: Scala, Antonio
name: Barthelemy, Marc
name: Stanley, H. Eugene
Publisher: name: arXiv
Year: 2000
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Small-world networks are the focus of recent interest because they appear to circumvent many of the limitations of either random networks or regular lattices as frameworks for the study of interaction networks of complex systems. Here, we report an empirical study of the statistical properties of a variety of diverse real-world networks. We present evidence of the occurrence of three classes of small-world networks: (a) scale-free networks, characterized by a vertex connectivity distribution that decays as a power law; (b) broad-scale networks, characterized by a connectivity distribution that has a power-law regime followed by a sharp cut-off; (c) single-scale networks, characterized by a connectivity distribution with a fast decaying tail. Moreover, we note for the classes of broad-scale and single-scale networks that there are constraints limiting the addition of new links. Our results suggest that the nature of such constraints may be the controlling factor for the emergence of different classes of networks.
Effective interaction between star polymers
Creators: name: Jusufi, A.
name: Watzlawek, M.
name: Loewen, H.
Publisher: name: arXiv
Year: 1999
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: The distance-resolved effective interaction between two star polymers in a good solvent is calculated by Molecular Dynamics computer simulations. The results are compared with a pair potential proposed recently by Likos et al. [Phys. Rev. Lett. 1998, 80, 4450] which is exponentially decaying for large distances and crosses over, at the corona diameter of the star, to an ultrasoft logarithmic repulsion for small distances. Excellent agreement is found in a broad range of star arm numbers.
description: final version as published, 9 pages + 5 ps-figures
The EDIBLES survey IV. Cosmic ray ionization rates in diffuse clouds from near-ultraviolet observations of interstellar OH$^+$
Creators: name: Bacalla, Xavier L.
name: Linnartz, Harold
name: Cox, Nick L. J.
name: Cami, Jan
name: Roueff, Evelyne
name: Smoker, Jonathan V.
name: Farhang, Amin
name: Bouwman, Jordy
name: Zhao, Dongfeng
Publisher: name: arXiv
Year: 2018
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We report cosmic ray ionization rates towards ten reddened stars studied within the framework of the EDIBLES (ESO Diffuse Interstellar Bands Large Exploration Survey) program, using the VLT-UVES. For each sightline, between 2 and 10 individual rotational lines of OH$^+$ have been detected in its (0,0) and (1,0) $A^3Π-X^3Σ^-$ electronic band system. This allows constraining of OH$^+$ column densities towards different objects. Results are also presented for 28 additional sightlines for which only one or rather weak signals are found. An analysis of these data makes it possible to derive the primary cosmic ray ionization rate $ζ_p$ in the targeted diffuse interstellar clouds. For the ten selected targets, we obtain a range of values for $ζ_p$ equal to $(3.9-16.4) \times 10^{-16}~\mathrm{s}^{-1}$. These values are higher than the numbers derived in previous detections of interstellar OH$^+$ in the far-infrared / sub-millimeter-wave regions and in other near-ultraviolet studies. This difference is a result of using new OH$^+$ oscillator strength values and a more complete picture of all relevant OH$^+$ formation and destruction routes (including the effect of proton recombinations on PAHs), and the relatively high $N$(OH$^+$) seen toward those ten targets.
Pourouma mollis Trécul
Creators: name: Molino, Jean-François
name: Sabatier, Daniel
name: Grenand, Pierre
name: Engel, Julien
name: Frame, Dawn
name: Delprete, Piero G.
name: Fleury, Marie
name: Odonne, Guillaume
name: Davy, Damien
name: Lucas, Eve J.
name: Martin, Claire A.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Rosales
Urticaceae
Pourouma
Pourouma mollis

description: [1754] Pourouma mollis Trécul
 Ann. Sci. Nat., Bot. sér. 3, 8: 102 (Trécul 1847).
VERNACULAR NAMES. — Pa: kwem-duwõ, kwem-puvemna • Wp: wɨlau pɨyũ’ ã • Cr: mal-bwa-kannon • Br: tararanga-vermelha, uvade-macaco.
 HERBARIUM DATA (FG). — 29 collections at CAY. Sel. exs.: F.M.R. Leprieur 141 (lecto-, P[P00757085], designated by Berg [Berg & Dewolf 1975: 272]; isolecto-, G[G00438436]).
INVENTORY DATA (FG). — 115 trees in 49 plots; Fmax = 1.5 %; dbhinv = 45.5 cm.
description: Published as part of Molino, Jean-François, Sabatier, Daniel, Grenand, Pierre, Engel, Julien, Frame, Dawn, Delprete, Piero G., Fleury, Marie, Odonne, Guillaume, Davy, Damien, Lucas, Eve J. & Martin, Claire A., 2022, An annotated checklist of the tree species of French Guiana, including vernacular nomenclature, pp. 345-903 in Adansonia (3) (3) 44 (26) on page 715, DOI: 10.5252/adansonia2022v44a26, http://zenodo.org/record/7458777
Observation of Diffractive W Boson Production at the Tevatron
Creators: name: CDF Collaboration
Publisher: name: arXiv
Year: 1997
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We report the first observation of diffractively produced W bosons. In a sample of W -> e nu events produced in p-barp collisions at sqrt{s}=1.8 TeV, we find an excess of events with a forward rapidity gap, which is attributed to diffraction. The probability that this excess is consistent with non-diffractive production is 1.1 10^{-4} (3.8 sigma). The relatively low fraction of W+Jet events observed within this excess implies that mainly quarks from the pomeron, which mediates diffraction, participate in W production. The diffractive to non-diffractive W production ratio is found to be R_W=(1.15 +/- 0.55)%.
description: 9pp, LaTex file, uses psfig, 3 PS figures, to be published in PRL