cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
$D_{sJ}$(2317) meson production at RHIC
Creators: name: Chen, L. W.
name: Ko, C. M.
name: Liu, W.
name: Nielsen, M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Production of $D_{sJ}$(2317) mesons in relativistic heavy ion collisions at RHIC is studied. Using the quark coalescence model, we first determine the initial number of $D_{sJ}$(2317) mesons produced during hadronization of created quark-gluon plasma. The predicted $D_{sJ}$(2317) abundance depends sensitively on the quark structure of the $D_{sJ}$(2317) meson. An order-of-magnitude larger yield is obtained for a conventional two-quark than for an exotic four-quark $D_{sJ}$(2317) meson. To include the hadronic effect on the $D_{sJ}$(2317) meson yield, we have evaluated the absorption cross sections of the $D_{sJ}$(2317) meson by pion, rho, anti-kaon, and vector anti-kaon in a phenomenological hadronic model. Taking into consideration the absorption and production of $D_{sJ}$(2317) mesons during the hadronic stage of heavy ion collisions via a kinetic model, we find that the final yield of $D_{sJ}$(2317) mesons remains sensitive to its initial number produced from the quark-gluon plasma, providing thus the possibility of studying the quark structure of the $D_{sJ}$(2317) meson and its production mechanism in relativistic heavy ion collisions.
description: 12 pages, 6 figures
Spirituality and COVID-19 pandemic: A qualitative inquiry of real time experiences in Pakistan
Creators: name: Barolia, Rubina
name: Ajani, Khairulnissa
name: Iqbal, Sajid
name: Abdullah, Muhammad
name: Danish, Sumera
name: Sajjad, Sehrish
name: Gowani, Ambreen
name: Barolia, Mehak
name: Petrucka, Pammla
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Medicine
subject: Evolutionary Biology
subject: FOS: Biological sciences
subject: Environmental Sciences not elsewhere classified
subject: Sociology
subject: FOS: Sociology
subject: Biological Sciences not elsewhere classified
subject: Cancer
subject: Mental Health
subject: Computational Biology

description: Many individuals are now reflecting on spirituality and religiosity being essential parts of their life that helped them cope and overcome the fears associated with COVID-19 during the quarantine period. Although medical interventions remained vital in managing the COVID-19 outbreak, little attention was given to the contributions of spirituality as a personal coping mechanism in South Asian culture. Through a qualitative descriptive exploratory approach, we explored the roles which spirituality and faith played in lives of COVID-19 patients and their families during the quarantine period in Karachi, Pakistan. Twenty-two dyads of COVID-19 patients and their family members were purposively selected and interviewed via telephone or Zoom. Quarantine was a reflective opportunity to focus on one’s inner-self and make spiritual connection or re-connection with God. Participants felt the pandemic reminded them that humanity must come closer, act as one household, and extend help to each other. However, there were conflicting views regarding the impacts of spirituality and religiosity during the restrictions and quarantine period.
Brownian soliton motion
Creators: name: Kartashov, Yaroslav V.
name: Vysloukh, Victor A.
name: Torner, Lluis
Publisher: name: arXiv
Year: 2008
Subjects: subject: Optics (physics.optics)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: We reveal fundamental analogies between soliton dynamics in light-induced random photonic lattices and Brownian motion of particles. In particular, we discover that the average squared soliton displacement increases linearly with distance after an initial ballistic regime of propagation. We also find that in shallow lattices the average soliton displacement grows linearly with increasing lattice depth.
description: 14 pages, 4 figures, to appear in Physical Review A
THE UNIFORM RATE OF COPPER UPTAKE BY Lemna Minor L. AND AN ALTERNATIVE TO USING FLAME ATOMIC ABSORPTION SPECTROPHOTOMETRY FOR DETERMINING COPPER CONTENT
Creators: name: Brown, Sarah M.
Publisher: name: Maryland Shared Open Access Repository
Year: 1997

description: The floating aquatic plant Lemna minor L., a species of duckweed, has been used as an indicator of heavy metal pollution and also as a method of removing metals and nutrients from wastewater at treatment plants. However, the rate of metal uptake by duckweed has not been thoroughly investigated, and plant operators need to know the optimum time for duckweed removal and replacement so that metal removal from the effluent stream will remain efficient. In addition, the method of determining the amount of metals in plant tissue usually involves the use of a flame atomic absorption spectrophotometer (AAS), which is not commonly available in a wastewater treatment plant. The first goal of this study was to track the rate of copper uptake by L. minor. The second goal was to develop and evaluate a new and different method of copper determination in plant tissues. This new method, which was designed for ease of use, required only nitric acid for frond digestion and sodium hydroxide and ammonium hydroxide solutions for sample processing to allow for visible spectrophotometric analysis on site at a treatment plant. It was found that during days 10-20 of exposure to media containing copper, the amount of copper present in L. minor samples decreased. This indicates that under the environmental conditions of this study, the optimum time for duckweed removal was in the first 10 days. It was also found that this experimental colorimetric method had a detection limit between 200-250 ppm (w/v ) copper. The results of this investigation demonstrate that duckweed fronds did not take up enough copper for the samples to be read colorimetrically, so the method could not be thoroughly evaluated. However, previous experiments have shown that under different environmental conditions, duckweed has the ability to take up far more copper than was observed. Although the colorimetric method was not useful for determining copper content at this time, it is possible that under different conditions it may become a practical method.
Order and Disorder in AKLT Antiferromagnets in Three Dimensions
Creators: name: Parameswaran, Siddharth A.
name: Sondhi, S. L.
name: Arovas, Daniel P.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The models constructed by Affleck, Kennedy, Lieb, and Tasaki describe a family of quantum antiferromagnets on arbitrary lattices, where the local spin S is an integer multiple M of half the lattice coordination number. The equal time quantum correlations in their ground states may be computed as finite temperature correlations of a classical O(3) model on the same lattice, where the temperature is given by T=1/M. In dimensions d=1 and d=2 this mapping implies that all AKLT states are quantum disordered. We consider AKLT states in d=3 where the nature of the AKLT states is now a question of detail depending upon the choice of lattice and spin; for sufficiently large S some form of Neel order is almost inevitable. On the unfrustrated cubic lattice, we find that all AKLT states are ordered while for the unfrustrated diamond lattice the minimal S=2 state is disordered while all other states are ordered. On the frustrated pyrochlore lattice, we find (conservatively) that several states starting with the minimal S=3 state are disordered. The disordered AKLT models we report here are a significant addition to the catalog of magnetic Hamiltonians in d=3 with ground states known to lack order on account of strong quantum fluctuations.
description: 7 pages, 2 figures
Limitations on the extent of off-center displacements in TbMnO3 from EXAFS measurements
Creators: name: Bridges, F.
name: Downs, C.
name: O'Brien, T.
name: Jeong, Il-K
name: Kimura, T.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We present EXAFS data at the Mn K and Tb L3 edges that provide upper limits on the possible displacements of any atoms in TbMnO3. The displacements must be less than 0.005-0.01A for all atoms which eliminates the possibility of moderate distortions (0.02A) with a small c-axis component, but for which the displacements in the ab plane average to zero. Assuming the polarization arises from a displacement of the O2 atoms along the c-axis, the measured polarization then leads to an O2 displacement that is at least 6X10^{-4}A, well below our experimental limit. Thus a combination of the EXAFS and the measured electrical polarization indicate that the atomic displacements likely lie in the range 6X10^{-4} - 5X10^{-3}A.
description: submitted to PRB; 11 pages (preprint form) 7 figures
Spin and charge interconversion in Dirac semimetal thin films
Creators: name: Yanez, Wilson
name: Ou, Yongxi
name: Xiao, Run
name: Koo, Jahyun
name: Held, Jacob T.
name: Ghosh, Supriya
name: Rable, Jeffrey
name: Pillsbury, Timothy
name: Delgado, Enrique Gonzalez
name: Yang, Kezhou
name: Chamorro, Juan
name: Grutter, Alexander J.
name: Quarterman, Patrick
name: Richardella, Anthony
name: Sengupta, Abhronil
name: McQueen, Tyrel
name: Borchers, Julie A.
name: Mkhoyan, K. Andre
name: Yan, Binghai
name: Samarth, Nitin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We report spin-to-charge and charge-to-spin conversion at room temperature in heterostructure devices that interface an archetypal Dirac semimetal, Cd3As2, with a metallic ferromagnet, Ni0.80Fe0.20 (permalloy). The spin-charge interconversion is detected by both spin torque ferromagnetic resonance and ferromagnetic resonance driven spin pumping. Analysis of the symmetric and anti-symmetric components of the mixing voltage in spin torque ferromagnetic resonance and the frequency and power dependence of the spin pumping signal show that the behavior of these processes is consistent with previously reported spin-charge interconversion mechanisms in heavy metals, topological insulators, and Weyl semimetals. We find that the efficiency of spin-charge interconversion in Cd3As2/permalloy bilayers can be comparable to that in heavy metals. We discuss the underlying mechanisms by comparing our results with first principles calculations.
$0^{++}$ Resonances Observed at BES
Creators: name: Zou, B. S.
name: Collaboration, for BES
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: In last 10 years, $0^{++}$ resonances have been observed and studied at BES in many processes, such as $J/ψ\toγπ^+π^-π^+π^-$, $γπ^+π^-$, $γπ^0π^0$, $γK^+K^-$, $γK_SK_S$, $γωϕ$, $ωπ^+π^-$, $ωK^+K^-$, $ϕπ^+π^-$, $ϕK^+K^-$, $ψ(2S)\to J/ψπ^+π^-$, $χ_{c0}\toπ^+π^-K^+K^-$, $π^+π^-π^+π^-$ etc.. The results on $0^{++}$ resonances observed at BES are reviewed.
description: Plenary talk at SCADRON70, Lisbon, Feb. 2008
Quasinormal modes and shadow of a Schwarzschild black hole with GUP
Creators: name: Anacleto, M. A.
name: Campos, J. A. V.
name: Brito, F. A.
name: Passos, E.
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We consider quantum corrections for the Schwarzschild black hole metric by using the generalized uncertainty principle (GUP) to investigate quasinormal modes, shadow and their relationship in the eikonal limit. We calculate the quasinormal frequencies of the quantum-corrected Schwarzschild black hole by using the sixth-order Wentzel-Kramers-Brillouin (WKB) approximation, and also perform a numerical analysis that confirms the results obtained from this approach. We also find that the shadow radius is nonzero even at very small mass limit for finite GUP parameter.
description: 14 pages, 7 figures, matches version published in Annals of Physics
Urban open space : the effect of objectives and regulations
Creators: name: Pringle, Barbara L.
Publisher: name: University of British Columbia
Year: 2010

description: This thesis is focused on one component of the urban environment: open space, specifically open space in the downtown core. Taking the position that supplying adequate and appropriate open space is an important civic responsibility, the thesis investigates the proposition that such open space can be created through the combined effect of urban open space objectives and urban regulations. The proposition is investigated in three parts. First, the influence of urban regulations on urban open space development is examined. The regulatory histories of New York's, San Francisco's and Vancouver's downtown cores are reviewed to identify regulations that have influenced open space. Most attention is given to Vancouver's regulatory history and urban development patterns. In general, the investigation revealed that, while San Francisco defined what constitutes adequate and appropriate urban open space, New York and Vancouver did not. Because of this lack of definition the regulations continued to be developed in response to immediate situations rather than in response to open space objectives. The second part uses the historic shifts in the understanding of open space to identify four fundamental objectives for the development of adequate and appropriate urban open space. The objectives are: open space for public use; open space to shape the urban environment; open space to improve environmental quality; and open space as a network. The third part compares the regulations, identified as influencing open space, with the proposed objectives. This comparision determines how effectively the regulations achieve the objectives. Finally, a decision-making process is outlined that would enable the narrow and effective actions of the regulations achieve the broad objectives identified for urban open space. The thesis concludes that through the combined effect of urban open space objectives and urban regulations, cities can define adequate and appropriate open space and influence development to create such spaces.
PRODUCTION AND ANALYSIS OF A FIBROBLAST GROWTH FACTOR RECEPTOR UTILIZING THE BACULOVIRUS/INSECT CELL SYSTEM
Creators: name: Brown, Sharron A. N.
Publisher: name: Maryland Shared Open Access Repository
Year: 1993

description: Fibroblast growth factors (FGFs) and their receptors (FGFRs) are known to play a role in Xenopus development. FGF-2 and FGFR-1 mRNA and protein are present in the oocyte and early embryo at the appropriate time and in sufficient concentration to be a mesodermal inducing factor in vivo. The purpose of this project was to produce and purify recombinant Xenopus FGFR- 1(rXFGFR-1) that was biologically and biochemically active. The Baculovirus/insect cell system was employed. Recombinant viral infection and protein production in infected insect cells were optimized. Antibodies raised against a peptide corresponding to XFGFR-1 were used to construct immunoaffinity columns for protein purification. Yield was 10Oug per 10⁸ infected insect cells. Functional rXFGFR-1 were found to be presented on the surface of infected insect cells and bound FGF-1 and FGF-2 specifically. Scatchard analysis of competitive binding studies revealed a dissociation constant of 1.5 nM with 3x10⁵ binding sites per cell. Kinase activity of the rXFGFR-1 was confirmed by immunoblotting cell extracts using an antiphosphotyrosine antibody, and autophosphorylation studies. Specificity of kinase activity was determined by phosphoamino acid analysis followed by thin layer chromatography. Post-translational modifications performed by the insect cells included signal peptide cleavage and glycosylation. The recombinant XFGFR-1 produced in the baculovirus/insect cell system has been shown to bind ligand, have functional and specific tyrosine kinase activity. The quantity of rXFGFR-1 produced and purified was adequate and the quality acceptable for further experimentation. Several lines of inquiry will be pursued involving library screening and other substrate searches, as well as ligand binding and receptor dimerization studies.
On the localized phase of a copolymer in an emulsion: subcritical percolation regime
Creators: name: Hollander, Frank den
name: Petrelis, Nicolas
Publisher: name: arXiv
Year: 2008
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60F10, 60K37, 82B27

description: The present paper is a continuation of \cite{dHP07b}. The object of interest is a two-dimensional model of a directed copolymer, consisting of a random concatenation of hydrophobic and hydrophilic monomers, immersed in an emulsion, consisting of large blocks of oil and water arranged in a percolation-type fashion. The copolymer interacts with the emulsion through an interaction Hamiltonian that favors matches and disfavors mismatches between the monomers and the solvents, in such a way that the interaction with the oil is stronger than with the water. The model has two regimes, supercritical and subcritical, depending on whether the oil blocks percolate or not. In \cite{dHP07b} we focussed on the supercritical regime and obtained a complete description of the phase diagram, which consists of two phases separated by a single critical curve. In the present paper we focus on the subcritical regime and show that the phase diagram consists of four phases separated by three critical curves meeting in two tricritical points.
description: 31 pages
SUBSPECIES IDENTIFICATION, GENETIC VARIATION, AND CONSERVATION OF THE CLOUDED LEOPARD (Neofelis nebulosa)
Creators: name: Buckley-Beason, Valerie A.
Publisher: name: Maryland Shared Open Access Repository
Year: 2004

description: The clouded leopard, Neofelis nebulosa, is one of the largest felids in Southeast Asia and is currently threatened by human persecution, habitat loss and fragmentation. We used modern molecular genetic techniques to examine the validity of traditionally used taxonomic nomenclature and investigated the molecular genetic variation for the clouded leopard in order to gain insight on its evolutionary history. We examined 51 microsatellites, and 3,900 base pairs of mitochondria' and nuclear genes to assess and compare genetic variation in 108 clouded leopards, 118 individuals of the five Panthera genus species, and 3 domestic cats. Clouded leopards showed similar levels of microsatellite genetic variation to the individual species of Panthera, but low levels of mtDNA and nuclear variation relative to species within Panthera genus. Evidence of divergences was found between the subspecies N. n. diardi and the mainland subspecies in all the nuclear and mitochondrial analyses. These differences were supported by a karyotype analysis where comparisons showed a distinct difference in the F3 chromosome between N. n. nebulosa and N. n. diardi. Based upon the molecular data and karyotype analysis, we recommend that the Bomean clouded leopards be classified as a distinct species. Conservation strategies for clouded leopards and the Bornean species should be reevaluated to incorporate the new taxonomic units.
title: Βαλλιστική μελέτη μεταλλικών βλημάτων σε στόχο νανοσύνθετου υλικού, με χρήση τεχνικής Laser Induced Forward Transfer
titleType: AlternativeTitle
Creators: name: Σαρηγιαννίδης, Σάββας
name: Sarigiannidis, Savvas
Publisher: name: National Technological University of Athens
Year: 2025
Subjects: Laser Transfer
Νανοσύνθετα υλικά
Βαλλιστική
High-speed imaging

description: Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) “Μικροσυστήματα και Νανοδιατάξεις”
Universal Scalar Leptoquark Action for Matching
Creators: name: Dedes, Athanasios
name: Mantzaropoulos, Kostas
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In this study we present a universal effective action for one-loop matching of all scalar leptoquarks. We use both the Universal One-Loop Effective Action (UOLEA) and covariant diagrams to evaluate the Wilson coefficients directly in the Green basis for up-to dimension-6 operators. On the technical side, we use the newly developed method of evaluating supertraces, to further validate the results stemming from the use of covariant diagrams. As an application, we perform a fully functional matching onto Standard Model Effective Field Theory (SMEFT) of a model with two scalar leptoquark fields: a weak isospin singlet and a doublet. We demonstrate its use by calculating several observables, such as lepton magnetic and electric dipole moments, neutrino masses, proton decay rate, while we comment upon fine tuning issues in this model. Apart from its phenomenological interest, this model generates the majority of dimension-6 operators and provides an EFT benchmark towards future matching automation.
description: 69 pages, v2: references added, v3: few sign errors and typos corrected, refs added, version matches JHEP publication
A Comparison of the Personality Dimensions and Parental Attitudes of Highly Creative and Less Creative Eighth Grade Students
Creators: name: Burke, Jane G.
Publisher: name: Maryland Shared Open Access Repository
Year: 1975

description: In the past thirty years many sychologists have focused their attention on creative behavior. Recent research in the field has concentrated on the concept of creativity as apart from, although somewhat dependent upon, intelligence and on the process of creative production. Research to determine the factors responsible for the development of creativity has included the study of the personality characteristics of highly creative individuals and the family attitude patterns of these individuals. This study compares the personality dimensions and parental attitudes of two groups of eight grade students, the high creative and the low creative.
Genomica avanzata per lo studio dei geni di resistenza a patogeni in pianta
Creators: name: Sanseverino, Walter
Publisher: name: Università degli Studi di Napoli Federico II
Year: 2009

description: I geni di resistenza hanno grossa importanza nel settore della genetica vegetale e del miglioramento genetico. Le loro caratteristiche genetiche e strutturali li rendono interessanti sia da un punto di vista scientifico sia nell’ottica di un loro utilizzo pratico. Sono una famiglia affascinante da studiare e capire i loro meccanismi evolutivi e di interazione con altre proteine rappresenta una sfida per il chiarimento di molte caratteristiche molecolari e di funzionamento. Questo studio propone un approccio innovativo per l’analisi dei geni R, utilizzando dati prodotti da esperimenti di genomica su larga scala, ed integra i risultati al fine di creare un corpus unico di conoscenze.
Un importante obbiettivo del miglioramento genetico è, da sempre, l’utilizzo dei geni R in programmi per la produzione di varietà con resistenze naturali nel rispetto dell’uomo e dell’ambiente. La creazione di una risorsa accessibile gratuitamente via web, specifica per i geni R; la loro catalogazione e caratterizzazione; lo sviluppo di strumenti di predizione genica specifici; la selezione di nuovi candidati per la lotta agli stress biotici, fa di questo lavoro una base salda per l’esplorazione dei meccanismi molecolari d’interazione pianta-patogeno e per l’isolamento di nuovi geni R da utilizzare, attraverso programmi di miglioramento genetico, nelle varietà del prossimo futuro.
Gravitational effects of intense electromagnetic fields
Creators: name: Marx, Pierre
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: In the presence of an electromagnetic (EM) field the space-time metrics are affected by the field potential. The principle of superposition, which usually rules EM fields, is no longer valid for the biggest fields and Maxwell's equations, for the free field, generally have a non-zero right-hand side. For weak potentials the metrics are very close to Euclidean metrics i.e. the gravitational field is negligible. Very high EM potentials and fields are necessary to create a measurable gravitational field and even higher to fail the principle of superposition. In this last case, the energy-impulsion tensor of the EM field has to be modified and the linearization of Einstein's equations is no longer possible.
description: 21 pages, translated to English by Pascal Segui
EVALUATION OF SEVERAL ANAEROBIC MARINE BACTERIA FOR THE PRODUCTION OF NOVEL BIOACTIVE COMPOUNDS
Creators: name: Burns, Michael
Publisher: name: Maryland Shared Open Access Repository
Year: 1993

description: Cultures of anaerobic marine bacteria belonging to the genera Desulfovibrio and Spirochaeta were isolated from their natural environment and evaluated for the production of bioactive metabolites. The extracts from cultures of nine isolates were tested on bioassays including antibacterial, antifungal, anti-AIDS, genotoxic and antineoplastic bioassay systems. Several extracts from cultures of isolates of Desulfovibrio spp. exhibited antibacterial activity against Gram positive bacteria. This activity was due to a nonpolar constituent of the spent culture medium.
Liquid State Genetic Programming
Creators: name: Oltean, Mihai
Publisher: name: arXiv
Year: 2023
Subjects: subject: Neural and Evolutionary Computing (cs.NE)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: A new Genetic Programming variant called Liquid State Genetic Programming (LSGP) is proposed in this paper. LSGP is a hybrid method combining a dynamic memory for storing the inputs (the liquid) and a Genetic Programming technique used for the problem solving part. Several numerical experiments with LSGP are performed by using several benchmarking problems. Numerical experiments show that LSGP performs similarly and sometimes even better than standard Genetic Programming for the considered test problems.
description: 10 pages, 1 figure, ICANNGA 2007, Lecture Notes in Computer Science, pp 220-229, vol 4431. Springer. arXiv admin note: text overlap with arXiv:2110.02014, arXiv:2111.14790
A Comparison of the Male Persona in Western Literature
Creators: name: Burtner, John T.
Publisher: name: Maryland Shared Open Access Repository
Year: 2016

description: The essay follows a selection of Western Literature including Homer's Odyssey, Marquez' s One Hundred Years of Solitude, Kundera' s The Unbelievable Lightness of Being, selected poetry by Walt Whitman and Williams' Cat on a Hot Tin Roof to examine the male persona as portrayed in different genres beginning as long ago as the writings of Homer and as recently as Tennessee Williams. While all have some similarities, there is a move toward recognizing the validity of a changing male persona in today's society. While there remains a definite perception of maleness, there is an apparent fluidity in the expectations and realities of being male.
Fine-Tuning in DBI Inflationary Mechanism
Creators: name: Chen, Xingang
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Astrophysics (astro-ph)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We show a model-independent fine-tuning issue in the DBI inflationary mechanism. DBI inflation requires a warp factor h small enough to sufficiently slow down the inflaton. On the other hand, the Einstein equation in extra dimensions under the inflationary background deforms the warp space in the IR side. Generically these two locations coincide with each other, spoiling the DBI inflation. The origin and tuning of this ``h-problem'' is closely related, through the AdS/CFT duality, to those of the well-known ``eta-problem'' in the slow-roll inflationary mechanism.
description: 13 pages; v4, several discussions expanded, JCAP version
Functional role of the CXCR4 chemokine receptor in thyroid cancer
Creators: name: Avilla, Elvira
Publisher: name: Università degli Studi di Napoli Federico II
Year: 2009

description: Thyroid cancer is the most common endocrine malignancy and its incidence is increasing worldwide. We previously found that normal rat thyroid cells, transduced with papillary thyroid cancer (PTC)-related oncogenes, display an inflammatory signature, that includes cytokines, chemokines and their receptors (Melillo at al., 2005). One of the chemokine receptors we identified, CXCR4, is frequently up-regulated in thyroid cancer and the chemokine SDF-1, a CXCR4 ligand, induces proliferation, survival and invasive ability of PTC cells; moreover, CXCR4 blocking compounds inhibit thyroid cancer growth (Castellone et al., 2004; De Falco et al., 2007). In order to better understand the molecular mechanisms of the biological effects of CXCR4/SDF-1α in thyroid carcer, we performed a global genome expression profile, through DNA microarrays, of CXCR4-expressing human papillary thyroid carcinoma cells (TPC-1) treated or not with SDF-1α. We identified, as transcriptional targets of CXCR4/SDF-1α, two tyrosine-kinase receptors: TYRO3 and AXL. These proteins belong to a small Protein Tyrosine Kinase (PTK) subfamily of receptors that includes three members: TYRO3, AXL and MER, from which this family is named TAM; they can be activated by two ligands, GAS6 and Protein S, are involved in the regulation of immune response, and are overexpressed in some epithelial cancers (Linger et al., 2008). We found that TPC-1 cells, derived from a human PTC, constitutively express TYRO3 and AXL receptors, but SDF-1α stimulation increased their protein level and tyrosine phosphorylation. We found that most of the available thyroid cancer cell lines express both the receptors, albeit to different extent, and AXL was always much more abundant than TYRO3. In most cell lines, the two receptors display high levels of tyrosine-phosphorylation, due to constitutive expression of GAS6. An exception to this rule was the TPC-1 cell line, in which AXL was highly phosphorylated despite the fact that GAS6 is absent. AXL and its ligand GAS6 are also overexpressed in human thyroid carcinoma samples with respect to normal thyroid, as assessed by IHC. The inhibition of TYRO3 and AXL by blocking reagents or RNA interference targeting each receptor or the ligand decreased cell proliferation and resistance to apoptotic stimuli in different thryoid cancer cell lines. In cell lines that expressed both receptors and ligand, the simultaneous blockade of these molecules dramatically affected cell viability. Accordingly, we showed that the stimulation of GAS6-negative TPC-1 cells with exogenous GAS6 increased their proliferation and survival. Finally, we found that the blockade of AXL receptor consistently impaired thyroid carcinoma cell line invasiveness through Matrigel and, moreover, it inhibited tumor growth in nude mice. In this thesis project, we provide evidences that targeting CXCR4/SDF-1 or TYRO3/AXL/GAS6 axis might be exploited as novel anticancer therapyes for human thyroid carcinomas.
Simultaneous Tactile Exploration and Grasp Refinement for Unknown Objects
Creators: name: de Farias, Cristiana
name: Marturi, Naresh
name: Stolkin, Rustam
name: Bekiroglu, Yasemin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: This paper addresses the problem of simultaneously exploring an unknown object to model its shape, using tactile sensors on robotic fingers, while also improving finger placement to optimise grasp stability. In many situations, a robot will have only a partial camera view of the near side of an observed object, for which the far side remains occluded. We show how an initial grasp attempt, based on an initial guess of the overall object shape, yields tactile glances of the far side of the object which enable the shape estimate and consequently the successive grasps to be improved. We propose a grasp exploration approach using a probabilistic representation of shape, based on Gaussian Process Implicit Surfaces. This representation enables initial partial vision data to be augmented with additional data from successive tactile glances. This is combined with a probabilistic estimate of grasp quality to refine grasp configurations. When choosing the next set of finger placements, a bi-objective optimisation method is used to mutually maximise grasp quality and improve shape representation during successive grasp attempts. Experimental results show that the proposed approach yields stable grasp configurations more efficiently than a baseline method, while also yielding improved shape estimate of the grasped object.
description: IEEE Robotics and Automation Letters. Preprint Version. Accepted February, 2021
Production of HIV-1(MN) Nucleocapsid Protein (p7) by Recombinant DNA Technology
Creators: name: Chaput Busch, Laura K.
Publisher: name: Maryland Shared Open Access Repository
Year: 1994

description: Members of the Retroviridae family of RNA viruses exhibit an extraordinarily rapid mutation rate. This rate of mutation not only enables these viruses to evade immune surveillance and develop drug resistance but has also resulted in great molecular diversity so that very few sequences are conserved between diverse members of the family. However, all lentiviral and oncoviral gag nucleocapsid (NC) proteins contain one or two copies of a highly conserved amino acid sequence: C X₂ C X₄ H X₄ C. The conserved cysteine and histidine residues coordinate zinc ions and form retroviral zinc fingers. Strict conservation of these viral zinc fingers suggests that they are absolutely required by the virus and therefore may be mutation intolerant. Mutational analysis has shown that viral zinc fingers are required for viral RNA packaging and also play an additional role in viral infectivity. The HIV-1 (NC) protein contains two retroviral zinc fingers and strict conservation and requirements for these structures suggests that they are a good target for retroviral drug therapy to combat the AIDS pandemic. Highly pure NC protein is a fundamental requirement for research and development of drugs that attack retroviral zinc fingers. To provide sufficient protein, the NC protein gene sequence was cloned into a bacterial expression vector (pMal-cᵀᴹ) and expressed as a maltose-binding protein-NC fusion protein. The vector contains a factor Xa protease recognition site so that NC can be released from the fusion protein with no vector derived sequences. RP-HPLC purification of the final product yields NC protein that is >97% pure. Recombinant NC protein was characterized by amino acid analysis, amino acid sequencing, mass spectrometry and nuclear magnetic resonance and recombinant protein is identical to native protein. Purified NC protein is a key component of the AIDS drug screening program to identify compounds that serve as anti-viral "zinc finger" drugs.
An inquiry into the psychology of counterfactuals
Creators: name: Read, Daniel
Publisher: name: University of British Columbia
Year: 2010

description: The relationship between events and the way people imagine they "might have happened" was explored. A synthesis of norm theory (Kahneman & Miller, 1986) and slippability (Hofstadter, 1979) incorporating the concept of a narrative level at which events with a high probability of evoking imagined alternatives was proposed as a framework for study. To test a number of hypotheses derived from this theoretical framework, a recognition task was used: subjects first read stories and then indicated which of a number of alternatives to the stories they had thought of while reading. It is demonstrated that events at the narrative level have a higher probability of being changed in imagination than other events. In addition, while the outcomes of suspenseful situations are readily changed, their premises are not. Overall, the recogntion technique is shown to be a useful method for determining the availability of alternatives.
Comment: Boosting Algorithms: Regularization, Prediction and Model Fitting
Creators: name: Buja, Andreas
name: Mease, David
name: Wyner, Abraham J.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences

description: The authors are doing the readers of Statistical Science a true service with a well-written and up-to-date overview of boosting that originated with the seminal algorithms of Freund and Schapire. Equally, we are grateful for high-level software that will permit a larger readership to experiment with, or simply apply, boosting-inspired model fitting. The authors show us a world of methodology that illustrates how a fundamental innovation can penetrate every nook and cranny of statistical thinking and practice. They introduce the reader to one particular interpretation of boosting and then give a display of its potential with extensions from classification (where it all started) to least squares, exponential family models, survival analysis, to base-learners other than trees such as smoothing splines, to degrees of freedom and regularization, and to fascinating recent work in model selection. The uninitiated reader will find that the authors did a nice job of presenting a certain coherent and useful interpretation of boosting. The other reader, though, who has watched the business of boosting for a while, may have quibbles with the authors over details of the historic record and, more importantly, over their optimism about the current state of theoretical knowledge. In fact, as much as ``the statistical view'' has proven fruitful, it has also resulted in some ideas about why boosting works that may be misconceived, and in some recommendations that may be misguided. [arXiv:0804.2752]
description: Published in at http://dx.doi.org/10.1214/07-STS242B the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org)
The transcription complex Prep1-Pbx1 regulates the gene expression of tyrosine phosphatases and impairs insulin action in liver cells
Creators: name: Iovino, Salvatore
Publisher: name: Università degli Studi di Napoli Federico II
Year: 2009

description: Prep1 is an homeodomain transcription factor belonging to the MEINOX subfamily of the TALE (three amino acid loop extension) proteins. Prep1 forms DNA-independent dimeric complexes with all isoforms of the Pbx homeodomain transcription factor, enhancing target specificity and regulatory function. Recently, we have shown that Prep1 deficiency in mice induces protection from diabetes and increased insulin sensitivity in muscle tissue through a mechanism which involves increased protein and mRNA levels of the glucose transporter (GLUT)-4 and the PPAR gamma coactivator-1 alpha (PGC-1. Since PGC-1promotes the gluconeogenesis in hepatic tissue, I have studied the role of Prep1 in regulating insulin signaling in liver of Prep1 hypomorphic (Prep1i/i, Prep1i/+) mice, which expressed respectively only 5-7% and 55-57% of protein. Despite the results obtained in muscle tissue, Prep1i/i and Prep1i/+ mice did not show changes in PGC-1protein and mRNA levels, but surprisingly they have an improved insulin-stimulated phosphorylation of IR and IRS-1/2. This is paralleled by an increase of glycogen content and a reduction of Glucose-6-phosphatase and PEPCK expression. Western blot analysis and qRT-PCR experiments displayed a gene-dosage dependent reduction of protein and mRNA levels of SHP1 and SYP tyrosine phosphatases in liver extracts of Prep1i/i, Prep1i/+ mice. In parallel, the overexpression of Prep1 and Pbx1 in and HepG2 (Human Hepatoma cell line) cells induced insulin resistance by increasing the protein content and mRNA expression of SHP1 and SYP phosphatases, which were paralleled by an inhibition of insulin-stimulated phosphorylation of IR, IRS-1/2 and glycogen accumulation. Interestingly, the overexpression of an inactive form of Prep1 (Prep1HR1), lacking of the interaction site between Prep1 and Pbx1, did not impair SHP1 and SYP expression and insulin-signaling in HepG2 cells. Moreover, in Prep1 overexpressing cells, antisense silencing of SHP1 but not that of SYP rescued insulin-dependent IR phosphorylation and glycogen accumulation. Finally, ChIP and Re-Chip experiments pointed out that the dimeric complex Prep1-Pbx1 bound specific sequences upstream the ATG codon of SYP and SHP1 genes (-625bp and -2113bp respectively) suggesting a direct gene regulation. Luciferase assays confirmed that the regions upstream SYP and SHP1 genes, were functionally activated by Prep1 and Pbx1 overexpression. Thus, the dimeric complex Prep1-Pbx1 directly regulates the gene expression of SYP and SHP1 tyrosine phosphatases by promoting insulin-resistance in liver cells.
Crisi di impresa e responsabilità da fatto illecito delle società alla luce dell’esperienza dei sistemi di Common Law
Creators: name: Bruno, Ferdinando
Publisher: name: Università degli Studi di Napoli Federico II
Year: 2006

description: Nel primo capitolo, intitolato Piercing the Corporate Veil negli ordinamenti di Common Law è stato esaminato il principio del piercing the corporate veil in Inghilterra. L'esame inizia con una ricognizione dei modelli societari utilizzati in tale paese, dei principi giuridici rilevanti in tema di società. Sono state poi esaminate le ipotesi di piercing the corporate veil e le posizioni della dottrina e della giurisprudenza, concludendo, poi, con un breve esame dell'esperienza americana. Nel secondo capitolo, intitolato Il problema del superamento della personalità giuridica in Italia, è stata trattata la problematica rispetto all'ordinamento italiano, iniziando con un breve esame della responsabilità patrimoniale prevista dall'art. 2740 c.c.. Sono state poi esaminate alcune di quelle che potrebbero essere ipotesi legislative di superamento della personalità giuridica, le ipotesi di repressione di abuso della personalità giuridica ed, infine, l'istituto dei patrimoni separati in relazione alla problematica de quo. L’analisi effettuata nella tesi sembrerebbe consentire di affermare che anche l’ordinamento italiano conosce ed applica il piercing the corporate veil, nel senso inteso nei paesi anglosassoni. Tale concetto, come emerso nel corso della ricerca, indica una moltitudine di casi in cui un soggetto che non ha speso in alcun modo il proprio nome con i terzi, si ritrova responsabile per obbligazioni, offrendo così un ulteriore patrimonio da aggredire ai creditori. Tale estensione la si rinviene, per le obbligazioni da atti leciti, nelle figure dell’amministratore di fatto (corrispondente allo shadow director anglosassone), la si ritrovava nell'ipotesi disciplinata dall'art. 2362 c.c., precedentemente alla riforma, e nelle ipotesi di abuso della personalità giuridica, in cui, come visto, la sanzione sarebbe quella di privare i soci tiranni del beneficio della responsabilità limitata. Infine, con la disciplina dei patrimoni separati, il Legislatore della recente riforma del diritto societario sembrerebbe avere aperto alla possibilità del superamento della personalità giuridica nei casi di illecito extracontrattuale imputabili ad una società di capitali.
Impersonating a Superconductor: High-Pressure BaCoO$_3$, an Insulating Ferromagnet
Creators: name: Wang, Haozhe
name: Xu, Xianghan
name: Ni, Danrui
name: Walker, David
name: Li, Jie
name: Cava, Robert J.
name: Xie, Weiwei
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We report the high-pressure synthesis (6 GPa, 1200 $^{\circ}$C) and ambient pressure characterization of hexagonal HP-BaCoO$_3$. The material (with the 2H crystal structure) has a short intrachain Co-Co distance of about 2.07 $\text{Å}$. Our magnetization investigation revealed robust diamagnetic behavior below approximately 130 K when exposed to weak applied magnetic fields (10 Oe) and a distinct half-levitation phenomenon below that temperature, such as is often observed for superconductors. Its field-dependent magnetization profile, however, unveils the characteristics of ferromagnetism, marked by a substantial magnetic retentivity of 0.22(1) $μ_B$/Co at a temperature of 2 K. Electrical resistivity measurements indicate that HP-BaCoO$_3$ is a ferromagnetic insulator, not a superconductor.
STag: Supernova Tagging and Classification
Creators: name: Davison, William
name: Parkinson, David
name: Tucker, Brad E.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Supernovae classes have been defined phenomenologically, based on spectral features and time series data, since the specific details of the physics of the different explosions remain unrevealed. However, the number of these classes is increasing as objects with new features are observed, and the next generation of large-surveys will only bring more variety to our attention. We apply the machine learning technique of multi-label classification to the spectra of supernovae. By measuring the probabilities of specific features or `tags' in the supernova spectra, we can compress the information from a specific object down to that suitable for a human or database scan, without the need to directly assign to a reductive `class'. We use logistic regression to assign tag probabilities, and then a feed-forward neural network to filter the objects into the standard set of classes, based solely on the tag probabilities. We present STag, a software package that can compute these tag probabilities and make spectral classifications.
description: 20 pages, 9 figures. Pages 13-20 are long tables. The code can be found at https://github.com/wdavison909/STag
Electron energy level statistics in graphene quantum dots
Creators: name: De Raedt, H.
name: Katsnelson, M. I.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Motivated by recent experimental observations of size quantization of electron energy levels in graphene quantum dots \cite{ponomarenko} we investigate the level statistics in the simplest tight-binding model for different dot shapes by computer simulation. The results are in a reasonable agreement with the experiment which confirms qualitatively interpretation of observed level statistics in terms of "Dirac billiards" without taking into account many-body effects. It is shown that edge effects are in general sufficient to produce the observed level distribution and that even strong bulk disorder does not change the results drastically.
description: Published: Pis'ma v ZhETF, vol. 88, iss. 9, pp. 698 -- 701 (2008)
Short-wavelength soliton in ultrarelativistic electron-positron-ion plasmas
Creators: name: Lashkin, V. M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: We derive a nonlinear equation governing dynamics of short-wavelength longitudinal waves in ultrarelativistic electron-positron-ion plasmas. In contrast to the recent work by Lashkin [Phys. Plasmas {\textbf{27}}, 102302 (2020)], where a similar equation was suggested in the framework of the Wigner function approach for a nonrelativistic electron-ion degenerate plasma, in our case which is based on the Vlasov kinetic equation all three species of particles (electrons, positrons and ions) should be present. The nonlinearity arises only in the presence of a population of ions. By numerical simulations we demonstrate that collisions between even four solitons are fully elastic.
description: arXiv admin note: text overlap with arXiv:2103.06082