bluuebunny/crossref_metadata_2025 huggingface dataset:
Chapter. 23. Features of pharmacotherapy, surgical technique of phacoemulsification and principles of working with devices to achieve mydriasis in patients with impaired diaphragmatic pupil function
Authors:   S. Fyodorov Eye Microsurgery Federal State Institution, Moscow, Russia, Malyugin Boris
Published: March 2021

Узкий зрачок – один из хорошо известных факторов риска в хирургии катаракты. Он может стать причиной целого ряда осложнений как во время операции, так и после неё. Сужение операционного поля ограничивает обзор хирурга, лимитирует его движения и вынуждает манипулировать в непосредственной близости от деликатных тканевых структур переднего отрезка глазного яблока. Это увеличивает вероятность их травмы, включая повреждение радужки, кровотечение из её сосудов, разрыв передней и задней капсул хрусталика, ретенцию фрагментов ядра и кортикальных масс, и приводит в ряде случаев к внекапсульной фиксации интраокулярной линзы (ИОЛ). Недостаточный мидриаз – не только механическое препятствие, затрудняющее проведение оперативного вмешательства. Это еще и симптом, вызванный различными системными и локальными сопутствующими заболеваниями, приводящими к нарушению гемато-офтальмического барьера, повышению проницаемости сосудистой стенки, дегенеративных изменений тканей переднего отрезка глаза, потере биомеханических свойств радужки, капсулы хрусталика и зонулярных волокон. К таковым заболеваниям относят глаукому, псевдоэксфолиативный синдром, диабет, увеит, ревматоидный артрит и ряд других. Глаза таких пациентов более склонны к послеоперационной экссудативно-воспалительной реакции, выпадению фибрина, образованию передних и задних синехий, фимозу и контрактуре капсульного мешка, помутнению задней капсулы, кистозному макулярному отёку и т.д. Интраоперационный флоппи-ирис-синдром (ИФИС), или синдром трепетания радужки, описанный в 2005 году докторами Д. Чангом и Д. Кэмпбеллом, является хорошим примером побочных эффектов системного применения ряда фармакологических препаратов. Первоначально к таковым относили исключительно альфа-агонисты, используемые для лечения аденомы простаты (тамсулосин, альфузосин и др.). Позднее круг лекарственных средств был расширен и теперь включает некоторые виды гипотензивных средств и антидепрессантов. При этом было отмечено, что эссенциальный ИФИС, не связанный с приемом лекарственных средств, характерен для ~14% глаз и, по-видимому, связан с особенностями анатомического строения радужки. Известно, что ИФИС приводит к целому ряду негативных последствий, включающих снижение биомеханической ригидности ткани радужки, ее трепетание под токами ирригации, прогрессивному сужению зрачка во время катарактальной операции и вставлению радужки в основной и дополнительные разрезы
On the structure of nonstabilizer Cliford codes
Authors: Klappenecker A.A. , Rotteler M.
Published: March 2021

Clifford codes are a class of quantum error control codes that form a natural generalization of stabilizer codes. These codes were introduced in 1996 by Knill, but only a single Clifford code was known, which was not already a stabilizer code. We derive a necessary and sufficient condition that allows one to decide when a Clifford code is a stabilizer code, and compile a table of all true Clifford codes for error groups of small order.
Simple construction of quantum universal variable-length source coding
Authors: Hayashi M. , Matsumoto K.
Published: March 2021

We simply construct a quantum universal variable-length source code in which, independent of information source, both of the average error and the probability that the coding rate is greater than the entropy rate H(\overline{\rho}_p), tend to 0. If H(\overline{\rho}_p) is estimated, we can compress the coding rate to the admissible rate H(\overline{\rho}_p) with a probability close to 1. However, when we perform a naive measurement for the estimation of H(\overline{\rho}_p), the input state is demolished. By smearing the measurement, we successfully treat the trade-off between the estimation of H(\overline{\rho}_p) and the non-demolition of the input state. Our protocol can be used not only for the Schumacher's scheme but also for the compression of entangled states.
Multipartite entanglement and hyperdeterminants
Authors: Miyake A. , Wadati M.
Published: March 2021

We classify multipartite entanglement in a unified manner, focusing on a duality between the set of separable states and that of entangled states. Hyperdeterminants, derived from the duality, are natural generalizations of entanglement measures, the concurrence, 3-tangle for 2, 3 qubits respectively. Our approach reveals how inequivalent multipartite entangled classes of pure states constitute a partially ordered structure under local actions, significantly different from a totally ordered one in the bipartite case. Moreover, the generic entangled class of the maximal dimension, given by the nonzero hyperdeterminant, does not include the maximally entangled states in Bell's inequalities in general (e.g., in the \(n \!\geq\! 4\) qubits), contrary to the widely known bipartite or 3-qubit cases. It suggests that not only are they never locally interconvertible with the majority of multipartite entangled states, but they would have no grounds for the canonical \(n\)-partite entangled states. Our classification is also useful for that of mixed states.
Limit theorems and absorption problems for quantum radom walks in one dimension
Authors: Konno N.
Published: March 2021

In this paper we consider limit theorems, symmetry of distribution, and absorption problems for two types of one-dimensional quantum random walks determined by $2 \times 2$ unitary matrices using our PQRS method. The one type was introduced by Gudder in 1988, and the other type was studied intensively by Ambainis et al. in 2001. The difference between both types of quantum random walks is also clarified.
Between entropy and subentropy
Authors: Nichols S.R. , Wootters W.K.
Published: March 2021

The von Neumann entropy and the subentropy of a mixed quantum state are upper and lower bounds, respectively, on the accessible information of any ensemble consistent with the given mixed state. Here we define and investigate a set of quantities intermediate between entropy and subentropy.
On the problem of authentication in a quantum protocol to detect traffic analysis
Authors: Muller-Quade J. , Steinwandt R.
Published: March 2021

Recently, a basic design for a quantum protocol to detect a perpetual traffic analysis of a communication channel has been proposed\cite{SJB01}. As it stands, this protocol does not take the problem of authentication into account. We show that a `standard' authentication procedure does not apply in this context, as the attacker is only interested in the number of transmitted bits. Moreover, we demonstrate how to use a one-time pad like construction for solving this authentication problem.
On the structure of a reversible entanglement generating set for tripartite states
Authors: Acin A. , Vidal G. , Cirac J.I.
Published: March 2021

We show that Einstein--Podolsky--Rosen--Bohm (EPR) and Greenberger--Horne--Zeilinger--Mermin (GHZ) states can not generate, through local manipulation and in the asymptotic limit, all forms of tripartite pure--state entanglement in a reversible way. The techniques that we use indicate that there is a connection between this result and the irreversibility that occurs in the asymptotic preparation and distillation of bipartite mixed states.
Local vs. joint measurements for the entanglement of assistance
Authors: Laustsen T. , Verstraete F. , van Enk S. J.
Published: March 2021

We consider a variant of the entanglement of assistance, as independently introduced by D.P. DiVincenzo et al. (quant-ph/9803033) and O. Cohen (Phys. Rev. Lett. 80, 2493 (1998)). Instead of considering three-party states in which one of the parties, the assistant, performs a measurement such that the remaining two parties are left with on average as much entanglement as possible, we consider four-party states where two parties play the role of assistants. We answer several questions that arise naturally in this scenario, such as (i) how much more entanglement can be produced when the assistants are allowed to perform joint measurements, (ii) for what type of states are local measurements sufficient, (iii) is it necessary for the second assistant to know the measurement outcome of the first, and (iv) are projective measurements sufficient or are more general POVMs needed?
Entanglement and nonlocality for a mixture of a pair-coherent state
Authors: Mancini S. , Tombesi P.
Published: March 2021

We consider a bipartite continuous variables quantum mixture coming from phase randomization of a pair-coherent state. We study the nonclassical properties of such a mixture. In particular, we quantify its degree of entanglement, then we show possible violations of Bell's inequalities. We also consider the use of this mixture in quantum teleportation. Finally, we compare this mixture with that obtained from a pair-coherent state by single photon loss.
Entanglement transformations of pure Gaussian states
Authors: Giedke G. , Eisert J. , Cirac J.I. , Plenio M.B.
Published: March 2021

We present a theory of entanglement transformations of Gaussian pure states with local Gaussian operations and classical communication. This is the experimentally accessible set of operations that can be realized with optical elements such as beam splitters, phase shifts and squeezers, together with homodyne measurements. We provide a simple necessary and sufficient condition for the possibility to transform a pure bipartite Gaussian state into another one. We contrast our criterion with what is possible if general local operations are available.
Logical network implementation for graph codes and cluster states
Authors: Schlingemann D.
Published: March 2021

In a previous paper a straight forward construction method for quantum error correcting codes, based on graphs, has been presented. These graph codes are directly related to cluster states which have been introduced by Briegel and Raussendorf. We show that the preparation of a cluster state as well as the coding operation for a graph code, can be implemented by a logical network by only using one type of two-qubit gate, e.g. CNOT or controlled Phase, and one type of one-qubit gate, e.g. the Hadamard transform. Concerning the qubit case each vertex corresponds to an Hadamard gate and each edge corresponds to a controlled not gate.
Fabrication of micro-magnetic traps for cold neutral atoms
Authors: Lev B.
Published: March 2021

Many proposals for quantum information processing require precise control over the motion of neutral atoms, as in the manipulation of coherent matter waves or the confinement and localization of individual atoms. Patterns of micron-sized wires, fabricated lithographically on a flat substrate, can conveniently produce large magnetic-field gradients and curvatures to trap cold atoms and to facilitate the production of Bose-Einstein condensates. The intent of this paper is to provide the researcher who has access to a standard clean-room enough information to design and fabricate such devices.
Generalized Bell inequalities with parametric down-conversion
Authors: Lamas-Linares A. , Irvine W.T.M. , Howell J.C. , Bouwmeester D.
Published: March 2021

We analize the suitability of states generated by stimulated parametric down-conversion for the testing of high dimensional Bell-type inequalities. Two families of bipartite inequalities are considered. For both it is found that the states are good candidates for the tests and some experimental results for one spin-1 inequality are given. The influence of noise and the possibility of supurious results are discussed.
Ground state entanglement in quantum spin chains
Authors: Latorre J.I. , Rico E. , Vidal G.
Published: March 2021

A microscopic calculation of ground state entanglement for the XY and Heisenberg models shows the emergence of universal scaling behavior at quantum phase transitions. Entanglement is thus controlled by conformal symmetry. Away from the critical point, entanglement gets saturated by a mass scale. Results borrowed from conformal field theory imply irreversibility of entanglement loss along renormalization group trajectories. Entanglement does not saturate in higher dimensions which appears to limit the success of the density matrix renormalization group technique. A possible connection between majorization and renormalization group irreversibility emerges from our numerical analysis.
Simplifying Schmidt number witnesses via higher-dimensional embeddings
Authors: Hulpke F. , Bruss D. , Levenstein M. , Sanpera A.
Published: March 2021

We apply the generalised concept of witness operators to arbitrary convex sets, and review the criteria for the optimisation of these general witnesses. We then define an embedding of state vectors and operators into a higher-dimensional Hilbert space. This embedding leads to a connection between any Schmidt number witness in the original Hilbert space and a witness for Schmidt number two (i.e. the most general entanglement witness) in the appropriate enlarged Hilbert space. Using this relation we arrive at a conceptually simple method for the construction of Schmidt number witnesses in bipartite systems.
Quantum solution to the hidden subgroup problem for Poly-Near-Hamiltonian groups
Authors: Gavinsky D.
Published: March 2021

The Hidden Subgroup Problem (HSP) has been widely studied in the context of quantum computing and is known to be efficiently solvable for Abelian groups, yet appears to be difficult for many non-Abelian ones. An efficient algorithm for the HSP over a group \f G\ runs in time polynomial in \f{n\deq\log|G|.} For any subgroup \f H\ of \f G, let \f{N(H)} denote the normalizer of \f H. Let \MG\ denote the intersection of all normalizers in \f G (i.e., \f{\MG=\cap_{H\leq G}N(H)}). \MG\ is always a subgroup of \f G and the index \f{[G:\MG]} can be taken as a measure of ``how non-Abelian'' \f G is (\f{[G:\MG] = 1} for Abelian groups). This measure was considered by Grigni, Schulman, Vazirani and Vazirani, who showed that whenever \f{[G:\MG]\in\exp(O(\log^{1/2}n))} the corresponding HSP can be solved efficiently (under certain assumptions). We show that whenever \f{[G:\MG]\in\poly(n)} the corresponding HSP can be solved efficiently, under the same assumptions (actually, we solve a slightly more general case of the HSP and also show that some assumptions may be relaxed).
Connections between relative entropy of entanglement and geometric measure of entanglement
Authors: Wei T.-C. , Ericsson M. , Goldbart P.M. , Munro W.J.
Published: March 2021

As two of the most important entanglement measures---the entanglement of formation and the entanglement of distillation---have so far been limited to bipartite settings, the study of other entanglement measures for multipartite systems appears necessary. Here, connections between two other entanglement measures---the relative entropy of entanglement and the geometric measure of entanglement---are investigated. It is found that for arbitrary pure states the latter gives rise to a lower bound on the former. For certain pure states, some bipartite and some multipartite, this lower bound is saturated, and thus their relative entropy of entanglement can be found analytically in terms of their known geometric measure of entanglement. For certain mixed states, upper bounds on the relative entropy of entanglement are also established. Numerical evidence strongly suggests that these upper bounds are tight, i.e., they are actually the relative entropy of entanglement.
Cluster states, algorithms and graphs
Authors: Schlingemann D.
Published: March 2021

The present paper is concerned with the concept of the one-way quantum computer, beyond binary-systems, and its relation to the concept of stabilizer quantum codes. This relation is exploited to analyze a particular class of quantum algorithms, called graph algorithms, which correspond in the binary case to the Clifford group part of a network and which can efficiently be implemented on a one-way quantum computer. These algorithms can ``completely be solved" in the sense that the manipulation of quantum states in each step can be computed explicitly. Graph algorithms are precisely those which implement encoding schemes for graph codes. Starting from a given initial graph, which represents the underlying resource of multipartite entanglement, each step of the algorithm is related to a explicit transformation on the graph.
Optimal realizations of simplified Toffoli gates
Authors: Song G. , Klappenecker A.
Published: March 2021

A simplified Toffoli gate coincides with the Toffoli gate except that the result is allowed to differ on one computational basis state by a phase factor. We prove that the simplified Toffoli gate implementation by Margolus is optimal, in the sense that it attains a lower bound of {\em three} controlled-not gates, and subject to that, a sharp lower bound of {\em four} single-qubit gates. We also discuss optimal implementations of other simplified Toffoli gates, and explain why the phase factor $-1$ invariably occurs in such implementations.
Local invariants for multi-partite entangled states allowing for a simple entanglement criterion
Authors: Aschauer H. , Calsamiglia J. , Hein M. , Briegel H.J.
Published: March 2021

We present local invariants of multi-partite pure or mixed states, which can be easily calculated and have a straight-forward physical meaning. As an application, we derive a new entanglement criterion for arbitrary mixed states of $n$ parties. The new criterion is weaker than the partial transposition criterion but offers advantages for the study of multipartite systems. A straightforward generalization of these invariants allows for the construction of a complete set of observable polynomial invariants.
A New Library-Search Algorithm for Mixture Analysis Using DART-MS
Authors: Moorthy Arun , Sisco Edward
Published: March 2021

This manuscript introduces a new library-search algorithm for identifying components of a mixture using in-source collision-induced dissociation (is-CID) mass spectra. The two-stage search, titled the Inverted Library-Search Algorithm (ILSA), identifies potential components in a mixture by first searching its low fragmentation mass spectrum for target peaks, assuming these peaks are protonated molecules, and then scoring each target peak with possible library matches using one of two schemes. Utility of the ILSA is demonstrated through several example searches of model mixtures of acetyl fentanyl, benzyl fentanyl, amphetamine and methamphetamine searched against a small library of select compounds and the NIST DART-MS Forensics library. Discussion of the search results and several open areas of research to further extend the method are provided. A prototype implementation of the ILSA is available at https://github.com/asm3-nist/DART-MS-DST.
Selective Manganese-Catalyzed Dimerization and Cross-Coupling of Terminal Alkynes
Authors: Weber Stefan , Veiros Luis F. , Kirchner Karl
Published: March 2021

For the first time, an efficient manganese-catalyzed dimerization of terminal alkynes to afford 1,3-enynes is described. This reaction is atom economic, implementing an inexpensive, earth abundant non-precious metal catalyst. The pre-catalyst is the bench-stable alkyl bisphosphine Mn(I) complex fac-[Mn(dippe)(CO)3(CH2CH2CH3)]. The catalytic process is initiated by migratory insertion of a CO ligand into the Mn-alkyl bond to yield an acyl intermediate which undergoes rapid C-H bond cleavage of the alkyne forming an active Mn(I) acetylide catalyst [Mn(dippe)(CO)2(C≡CPh)(η2-HC≡CPh)] together with liberated butanal. A range of aromatic and aliphatic terminal alkynes were efficiently and selectively converted into head-to-head Z-1,3-enynes and head-to-tail gem-1,3-enynes, respectively, in good to excellent yields. Moreover, cross-coupling of aromatic and aliphatic alkynes yields selectively head-to-tail gem-1,3-enynes. In all cases, the reactions were performed at 70 °C with a catalyst loading of 1-2 mol %. A mechanism based on DFT calculations is presented.
Ultrafast Energy Transfer Between Lipid-Linked Chromophores and Plant Light-Harvesting Complex II
Authors: Hancock Ashley M. , Son Minjung , Nairat Muath , Wei Tiejun , Jeuken Lars J. C. , Duffy Christopher D. P. , Schlau-Cohen Gabriela S. , Adams Peter G.
Published: March 2021

Light-Harvesting Complex II (LHCII) is a membrane protein found in plant chloroplasts that has the crucial role of absorbing solar energy and subsequently performing excitation energy transfer to the reaction centre subunits of Photosystem II. LHCII provides strong absorption of blue and red light, however, it has minimal absorption in the green spectral region where solar irradiance is maximal. In a recent proof-of-principle study, we enhanced the absorption in this spectral range by developing a biohybrid system where LHCII proteins together with lipid-linked Texas Red (TR) chromophores were assembled into lipid membrane vesicles. The utility of these systems was limited by significant LHCII quenching due to protein-protein interactions and heterogeneous lipid structures. Here, we organise TR and LHCII into a lipid nanodisc, which provides a homogeneous, well-controlled platform to study the interactions between TR molecules and single LHCII complexes. Fluorescence spectroscopy determined that TR-to-LHCII energy transfer has an efficiency of at least 60%, resulting in a 255% enhancement of LHCII fluorescence, two-fold greater than in the previous system. Ultrafast transient absorption spectroscopy revealed two time constants of 3.7 and 128 ps for TR-to-LHCII energy transfer. Structural modelling and theoretical calculations indicate that these timescales correspond to TR-lipids that are loosely- or tightly-associated with the protein, respectively, with estimated TR-to-LHCII separations of ~3.5 nm and ~1 nm. Overall, we demonstrate that a nanodisc-based biohybrid system provides an idealised platform to explore the photophysical interactions between extrinsic chromophores and membrane proteins with potential applications in understanding more complex natural or artificial photosynthetic systems.
Ruthenium Complex Hydride Catalysts as a Platform for Ammonia Synthesis
Authors: Wang Qianru , Guo Jianping , Chen Ping
Published: March 2021

Mild-condition ammonia synthesis from N2 and H2 is a long-sought-after scientific goal and a practical need, especially for the intensively pursued “Green Ammonia” production using renewable H2. Under this context, there have been growing interests in the development of new catalysts for effectively catalyzing N2+H2 to NH3. Particular attention has been given to Ru-based catalysts because they are well known to be more active at lower temperatures and pressures than non-noble-metal based catalysts. Here, we demonstrate that a series of Ru complex hydrides An[RuHm], where A is alkali or alkaline earth metal, n= 2, 3 or 4 and m = 6 or 7, exhibit universal and high catalytic activities that far exceed the benchmark Ru metal catalysts under mild conditions. Detailed investigations on the ternary Ru complex hydride catalytic system disclose that the kinetic behaviors depend strongly on the identity of alkali or alkaline earth metal cations. In clear contrast to the closed packed Ru metal catalyst, the unique configuration and synergized scenario of the Ru complex hydride center prefer a non-dissociative mechanism for N2 activation and hydrogenation, which provides a new platform for the design and development of efficient NH3 synthesis catalysts.
Fixation of Dinitrogen at an Asymmetric Binuclear Titanium N2 Complex
Authors: Bae Dae Young , Lee Gunhee , Lee Eunsung
Published: March 2021

We report the first example of a binuclear Ti–N2 complex withtriphenolamine that adopts trigonal bipyramidal and octahedralgeometries on the Ti centers. The activated N2 was reduced toammonia with 154% yield (per Ti atom) in the presence ofproton and electron sources.
Engineering P450 TamI as an Iterative Biocatalyst for Selective Late-Stage C-H Functionalization and Epoxidation of Tirandamycin Antibiotics
Authors: Espinoza Rosa V. , Caddell Haatveit Kersti , Grossman S. Wald , Tan Jin Yi , McGlade Caylie A. , Khatri Yogan , Newmister Sean A. , Schmidt Jennifer J. , Garcia-Borràs Marc , Montgomery John , Houk Kendall N , Sherman David H.
Published: March 2021

Iterative P450 enzymes are powerful biocatalysts for selective late-stage C-H oxidation of complex natural product scaffolds. These enzymes represent new tools for selectivity and cascade reactions, facilitating direct access to core structure diversification. Recently, we reported the structure of the multifunctional bacterial P450 TamI and elucidated the molecular basis of its substrate binding and strict reaction sequence at distinct carbon atoms of the substrate. Here, we report the design and characterization of a toolbox of TamI biocatalysts, generated by mutations at Leu101, Leu244 and/or Leu295, that alter the native selectivity, step sequence and number of reactions catalyzed, including the engineering of a variant capable of catalyzing a four-step oxidative cascade without the assistance of the flavoprotein and oxidative partner TamL. The tuned enzymes override inherent substrate reactivity enabling catalyst- controlled C-H functionalization and alkene epoxidation of the tetramic acid-containing natural product tirandamycin. Five new, bioactive tirandamycin derivatives (6-10) were generated through TamI-mediated enzymatic synthesis. Quantum mechanics calculations and MD simulations provide important insights on the basis of altered selectivity and underlying biocatalytic mechanisms for enhanced continuous oxidation of the iterative P450 TamI.
Manganese Catalyzed Anti-Markovnikov Hydroamination of Allyl Alcohols via Hydrogen Borrowing Catalysis
Authors: Das Kuhali , Sarkar Koushik , Maji Biplab
Published: March 2021

A phosphine ligand free manganese(I)-complex catalyzed the selective anti-Markovnikov hydroamination of allylic alcohols via waste-free hydrogen transfer mechanism. The γ-amino alcohol products are versatile synthetic intermediates for the synthesis of several drug molecules.
Diverse Proton-Conducting Nanotubes via a Tandem Macrocyclization and Assembly Strategy
Authors: Strauss Michael , Jia Manping , Evans Austin , Castano Ioannina , Li Rebecca , Aguilar-Enriquez Xavier , Roesner Emily , Swartz Jeremy , Chavez Anton , Enciso Alan E. , Stoddart J. Fraser , Rolandi Marco , Dichtel William
Published: March 2021

Macrocycles that assemble into nanotubes exhibit emergent properties stemming from their low dimensionality, structural regularity, and distinct interior environments. Here, we report a versatile strategy to synthesize diverse nanotube structures in a single, efficient reaction by using a conserved building block bearing a pyridine ring. Imine condensation of a 2,4,6-triphenylpyridine-based diamine with various aromatic dialdehydes yields chemically distinct pentagonal [5+5], hexagonal [3+3], and diamond-shaped [2+2] macrocycles depending on the substitution pattern of the aromatic dialdehyde monomer. Atomic force microscopy and in solvo X-ray diffraction demonstrate that protonation of the macrocycles under the mild conditions used for their synthesis drives assembly into high-aspect ratio nanotubes. Each of the pyridine-containing nanotube assemblies exhibited measurable proton conductivity by electrochemical impedance spectroscopy, with values as high as 10-3 S m-1 (90% R.H., 25°C) that we attribute to differences in their internal pore sizes. This synthetic strategy represents a general method to access robust nanotube assemblies from a universal pyridine-containing monomer, which will enable systematic investigations of their emergent properties.
Comparative evaluation of anti-diabetic action and pancreatic histopathology of rats treated with two alkaloidal plant extracts
Authors: Bonagiri Sreedevi  , Vijaya Kuchana  , Shobharani S
Published: March 2021

This study aimed to understand Strychnosnuxvomica and Holarrhena pubescens Stem bark extract action towards M3 receptor in controlling blood glucose levels. Strychnos nux vomica  and Holarrhena pubescens are both alkaloidal drugs can help in controlling Hyperglycemic level. This will be useful in the formulation of a new herbal drug molecule for treating diabetes. Chloroform and ethanolic extracts of selected alkaloidal plants were extracted using the soxhlet apparatus and obtained quotes were tested for acute toxicity studies and carried out anti-diabetic action on Wister albino rats for 21 days. Results obtained from Blood glucose levels and histopathological study of test groups are compared with blood glucose levels of standard group, and highly significant action was identified by the chloroform extract of Strychnos nux vomica and Holarrhena pubescens group. Moderate anti-diabetic action was observed remaining two groups of ethanolic extracts. Strychnos nux vomica and Holarrhena pubescens ethanolic extract groups are acting on M3 receptors and controlling Hyperglycemic levels.
Assessment of anti-diabetic activity of alcoholic and hydro-alcoholic extract of Terminalia arjuna & Syzygium cumini in streptozotocin-induced diabetes in Wistar rats
Authors: Takru Harshit  , Dixit Praveen K  , Kumar Kapil  , Nagarajan K
Published: March 2021

We aimed to evaluate the effect of anti-diabetic activity of Terminalia arjuna, and Syzygium cumini extracts in Streptozotocin (STZ) induced diabetes in Wistar rats. STZ (55mg/kg) followed by nicotinamide (100mg/kg) was given to rats by intraperitoneal route to induce diabetes. Oral administration of alcoholic and hydro-alcoholic extracts of T. arjuna (TAAE) (250mg/kg and 500mg/kg), S. cumini (SCAE) (200mg/kg and 400mg/kg) and their composite extract were given to rats along with standard anti-diabetic drug Glibenclamide (5mg/kg). We evaluated body weight, glucose level, lipid profile and biochemical parameters in STZ induced diabetic rats. Also, histopathological studied were done in liver, kidney and pancreatic tissues of rats. Our finding revealed that TAAE and TAHE at 250mg/kg b.w. and 500mg/kg b.w., SCAE and SCHE at 400mg/kg b.w. and combination of TAAE (250mg/kg b.w.)+SCAE (400mg/kg b.w.) had a positive effect in lowering the blood glucose level and body weight on 28th day as compared to the initial observation on 0th day and also restored all the biochemical parameters such as LDL, VLDL, triglycerides and total Cholesterol and HDL towards the normal levels as well as histopathological improvement in Kidney, Liver and Pancreas. Data analysis showed that composite extract of TAAE (250mg/kg) and SCAE (400mg/kg ) improved diabetic consequences more effectively than composite extract of TAHE (500mg/kg) and SCHE (400mg/kg). TAAE and SCHE, in combination, demonstrate as a potential therapeutic agent against diabetes.
Redefining the reference librarian in the university environment
Authors: Ursachi Lenuța
Published: March 2021

The reference librarian and the services provided hold more than ever the attention of users at the “Dun?rea de Jos” University Library of Galati (DJULG). The Internet, technology and struggle for survival left a significant mark on both librarians' skills and reference services in the new context of the information society. In order to align with new trends in librarianship and to respond effectively to the increasingly complex demands of users, the reference librarians had to move beyond the traditional and reinvent themselves. As a result, new skills have been acquired and new services emerged in the information landscape of the university library.

The paper examines the evolution of the reference services at DJULG over the last ten years, emphasizing the changes of the librarian profile in this area. The variety of information sources, the emergence of new information technologies, the movement on open access have been the main elements that contributed to the professional development of the reference librarian and the implementation of new models of services for users. The case of the university library in this study reveals different profiles of the reference librarian: researcher, educator in information literacy, bibliometrician, wikilibrarian, digital resources manager, reference manager etc. Not far from the truth, we can say that the reference librarian became a chameleon, from the perspective of information evolution and ensuring sustainable library services.
(پەرتووكا "الاكراد فی بهدینان" د خواندنەكا رەخنەیی و ڕاستڤەكرنێن دیرۆكی دا (ڤەكۆلینەكا بەڵگەنامەیی
Authors: Kemal Rekani Hersh
Published: March 2021

په‌رتووكا (الاكراد فی بهدینان) یا نڤیسه‌ر و مێژوونڤیسێ به‌رنیاسێ به‌هدینان (مه‌لا ئەنوه‌رێ مایی) ، كو په‌رتووكه كا تایبه‌ت دهێته‌ هژمارتن یا تایبه‌تمه‌ند ل سه‌ر دیرۆكا كوردێن ده‌ڤه‌را به‌هدینان ئەوا ل سالا 1960 ل مووسل هاتیه‌ چاپكرن ، ژ بۆ خواندنه‌كا ره‌خنه‌یی و دیاركرنا چه‌ندین تێبینی و راستڤه‌كرنێن دیرۆكی ل سه‌ر ڤێ په‌رتووكێ ل دویڤ به‌لگه‌نامه‌ و ده‌ستنڤیسان، ژ به‌ركو ئەڤ په‌رتووكه‌ وه‌ك لێڤه‌گه‌ر مشه‌ دهێته‌ بكارینان ، دا پتر ببیته‌ جهێ مفای و بۆ چاپێن بهێت راوه‌ستاندنه‌كا زانستی ل سه‌ر بهێته‌ كرن ، ئەڤ ڤه‌كۆلینه‌ دێ بزاڤێ كه‌ت ل دویڤ به‌لگه‌نامه‌یێن ره‌سه‌ن و ده‌ستنڤیسان چه‌ندین شاشی و تێكه‌لكرنێن دیرۆكی د ڤێ په‌رتووكێ دا راستڤه‌كه‌ت و ل سه‌ر بنه‌مایه‌كێ زانستی شرۆڤه‌كه‌ت، و دێ پتر گرنگیێ ده‌ته‌ دیرۆكا ل سه‌رده‌مێ میرگه‌ها به‌هدینان و ده‌وله‌تا عوسمانی. ڤەكۆلین ل سەر سێ‌ تەوەران هاتیە دابەشكرن : ئێك : میرێن میرگەها بەهدینان دوو : زانا و هۆزانڤان و ناڤدار سێ‌ : روودان.
La investigación formativa en Educación Superior: modelo para docentes y estudiantes
Authors: Cabrera-Berrezueta Bolívar , Cárdenas-Cordero Nancy , García-Herrera Darwin Gabriel
Published: March 2021

El presente artículo aborda temas que se relacionan con la investigación formativa en la Educación Superior, mediante la relación de los ejes sustantivos como: docencia, investigación y vinculación con la sociedad. Estas funciones van encaminadas a establecer un modelo para los docentes y los estudiantes con la finalidad de desarrollar competencias investigativas a través de una adecuada fundamentación epistemológica y filosófica, con el uso de metodologías activas y el aprovechamiento de las tecnologías emergentes. La metodología empleada es de tipo bibliográfica descriptiva. Para el modelo propuesto se utilizó la modelación como método de investigación. Finalmente, la calidad de la educación exige docentes y estudiantes investigadores con nuevos retos y desafíos, lo cual implica el desarrollo del pensamiento crítico, reflexivo e innovador de forma que les permita ser gestores en la búsqueda de problemas educativos que enfrenta la sociedad y la capacidad de brindarles la solución oportuna en bien del país.
Percepción y programación deportiva en los estudiantes de la Universidad Estatal Península de Santa Elena
Authors: Paula-Chica Maritza Gisella
Published: March 2021

El objetivo de esta investigación ha sido el análisis de la eficacia del rendimiento deportivo mediante un programa basado desde un diagnóstico previo en la asimilación de contenidos. Se ha utilizado un diseño casi-experimental de tipo pre-during programación. Un total de 82 estudiantes de la carrera de Educación Básica de la UPSE, han participado en este estudio desarrollado desde sus hogares en tiempos de pandemia. Utilizando 55 sesiones de entrenamientos. En una primera fase se evaluaron las adaptaciones de tiempos, repeticiones, pesos y movimientos visuales, posturales y técnicos del tiempo de respuesta a estímulos periféricos, la estereopsis y la atención selectiva focalizada durante la práctica deportiva. Los estudiantes y docente valoraron el rendimiento deportivo mediante los parámetros y estándares sobre tiempo, repeticiones, pesos y movimientos de concentración, velocidad perceptiva y visión periférica, que se concretan en los resultados diarios de cada wod de la programación. En una segunda fase de intervención se identifica el aumento progresivo de la carga según diagnóstico previo que permitía el ingreso de la programación desde la primera sesión. Repartidas de la siguiente manera: Sesiones adaptativas, sesiones con aumento de carga, sesiones con aumentos de tiempos y repeticiones, sesiones de restauración, sesiones de la continuidad del aumento progresivo. Adicionalmente, tanto los estudiantes como su entrenadora siguieron valorando cada sesión para el mencionado aumento progresivo de carga vista desde un macrociclo de entrenamiento. Se sigue dando continuidad a la programación con otros grupos más vulnerables; Los resultados obtenidos indican que el programa de entrenamiento proporciona mejoras estadísticamente significativas en la mayor parte de habilidades evaluadas (tiempos, repeticiones, pesos, movimientos visuales, posturales y técnicos), potenciando así mismo el rendimiento deportivo.
El estrés laboral y su incidencia en el desempeño del personal administrativo
Authors: Soriano-Tumbaco Claudio Eduardo
Published: March 2021

Los recursos humanos son parte de los componentes más importantes de los procesos dentro de una organización. En la UPSE, existe un estudio socioeconómico del trabajador, desarrollado por la Unidad Administrativa de Talento Humano, pero en la actualidad no existe una caracterización de sus grupos profesionales, según los riesgos psicosociales, pues su estudio se encuentra en desarrollo. El objetivo de este trabajo es contribuir al desarrollo de los perfiles de riesgos psicosociales y de salud, desde la perspectiva del desempeño laboral. Se tomó el cuestionario Maslach Burnout Inventory (MBI) como instrumento principal para medir el estrés laboral del personal administrativo. Su función es medir el desgaste profesional, así como la frecuencia y la intensidad con la que se sufre el Burnout. Este test es conocido como el test de Burnout y está estandarizado para ámbitos laborales. En este estudio se buscó medir la confiabilidad de las respuestas ofrecidas, para lo que se utilizó el Coeficiente Alfa de Cronbach. Se recibieron respuestas de 78 encuestados, que significan el 40,6% de la población total. Las respuestas no alcanzaron el tamaño de la muestra, aun cuando el cuestionario fue enviado en tres ocasiones. Los resultados obtenidos en esta investigación permiten afirmar que  no existe presencia de estrés laboral en el personal administrativo de la Universidad Estatal Península de Santa Elena.  Al analizar las dimensiones del Síndrome de Burnout en la muestra estudiada se confirma que existe un nivel bajo de indicios de Cansancio emocional y de despersonalización.
Investigación sobre la aceptación de la soya en La Troncal
Authors: Olivo-Olivo Martha Alejandra , Zambrano-Garces Rosa Maria , Tenempaguay-Pogyo Jonathan , Quinteros Cortazar Marcos
Published: March 2021

El presente trabajo tiene como objetivo principal presentar los resultados del estudio de mercado realizado por la Universidad Católica de Cuenca extensión San Pablo de La Troncal, con los estudiantes de la carrera de empresas. En la línea de Gestión empresarial con responsabilidad social en el ámbito de creación de empresas y creación de PYMES. Bajo la dirección de 3 docentes principales. La soya es un grano que pertenece a la familia de la leguminosa cuyo contenido principal es el aceite y el alto contenido de proteína, por este motivo se emplea de alimento tanto para el consumo humano y/o animal, como principal beneficio reduce el azúcar en la sangre de aquellas personas diabéticas, además reduce el colesterol, entre otros beneficios. Los objetivos en el proceso de la presente investigación fueron analizar la demanda potencial de los productos derivados de la soya, valoración sensorial, y diseño de estrategias de mercado en el cantón La Troncal. El modelo de investigación empleado fue el cuantitativo probabilístico. La recolección de la información se hizo mediante encuesta. La población objeto de estudio del cantón La Troncal correspondió a 54.389 habitantes. La muestra calculada fue de 276 personas con un nivel de confianza del 94% y un margen de error del 6%. Los resultados y conclusiones nos permiten determinar que el mercado potencial de nuestro emprendimiento tiene 82% de aceptación, quienes los consumirían como mínimo dos veces por semana, lo cual permite determinar la viabilidad comercial de los productos derivados de la soya. Siendo el derivado de mayor aceptación de los consumidores la “leche de soya”. Las estrategias se formularon con base en la mezcla de mercadeo (precio, producto, plaza promoción y publicidad).
Sounding-derived parameters associated with severe hail events in Romania
Authors: Istrate Vasilică , Dobri Radu Vlad , Bărcăcianu Florentina , Ciobanu Răzvan Alin , Apostol Liviu
Published: March 2021

The present paper analyzes 549 severe weather events reported to the ESWD (European Severe Weather Database) that caused large hail in the territory of Romania. Values of atmospheric instability indices have been analyzed for these episodes using data from Bucharest and Budapest sounding stations. For a period of 140 days with episodes of large hail, 24 instability indices were analyzed to describe the atmospheric conditions of the main daily convective activity. The mean values for most indices characterize an unstable atmospheric environment. Of the indices that measure potential instability, VT (vertical totals index) and TT (totals index) had values that described a conductive atmospheric environment for the development of hailstorms. In addition, the interquartile values of LIV (lifted index using virtual temperature) had values lower than zero. For SWEAT (severe weather threat index) and CAPEV (convective available potential energy index using virtual temperature), only the values in the 75th percentile describe a very unstable environment (according to the literature). Strong linear correlations were registered between several pairs of indices such as CAPEV-LIV and SWEAT-SI that can be used for the operational forecast of hail.
A statistical analysis of the relationship between domestic hot water consumption and mean outdoor temperature in Budapest
Authors: Horkai András
Published: March 2021

This study analyzes how outdoor temperature influences domestic hot water consumption in multiapartment large-panel system buildings in Budapest, Hungary. The analysis is based on data from the validated invoicing system of the district heating provider, and from two weather stations of the Hungarian Meteorological Service. The official monthly hot water consumption data of 72 buildings for 7 consecutive years and the corresponding monthly mean temperatures were used in this study. Linear regression analysis and time series decomposition were carried out. The results prove that the outdoor temperature and the domestic hot water consumption are definitely related. The model based on regression analysis could account for 74% of values. The time series decomposition model is able to estimate hot water consumption per apartment per day for a future month with 94% probability. The study relies on data obtained from a projection of two regional climate models each, namely ALADIN-Climate and RegCM. Based on these data, the model forecasts how the effects of climate change will probably influence domestic hot water consumption in the near future. These results shed light on the factors influencing hot water consumption, and may help authorities and decision makers to form sustainability policies and to plan sustainable resource management.
Geostatistical comparison of UERRA MESCAN-SURFEX daily temperatures against independent data sets
Authors: Chervenkov Hristo , Slavov Kiril
Published: March 2021

Regional reanalises are attractive new sources of meteorological data for the growing society of the end users, due to their physical consistency, dynamical coherency, and multivariate products at higher than the global reanalises spatio-temporal resolution. The assessment and quantification of uncertainties of the products of the regional reanalises and their added value are crucial for the interpretation. Hence these products could be also incorporated in the regional climatology, consistent comparisons of their long-term timeseries against independent and representative data sets have to be performed. The present study could be considered as step ahead in this direction - the MESCAN-SURFEX, which is the product with the most detailed spatial structure among all others in the UERRA (Uncertainties of Ensembles in Regional Reanalysis) project, is compared against two gridded observational data sets in South-east Europe: the well-known regional CARPATCLIM and the product of the Bulgarian National Institute of Meteorology and Hydrology ProData. The comparison aims to assess the skill of MESCAN-SURFEX to reproduce the climatological field of the mean temperature. Additionally, the daily extreme temperatures are estimated using the MESCAN-SURFEX output on sub daily basis and the results are compared against their CARPATCLIM- and ProData-counterparts. The computation of the mean and extreme temperatures with the MESCAN/SURFEX data are performed for the whole time span of this product and the comparison against the references for the whole time span of each of them on daily basis. The main conclusion of the study, which agrees with the outcomes of more detailed recent evaluations, is that MESCAN-SURFEX reproduces realistically the regional temperature field over Southeast Europe. According to the mean temperature, the differences remains under certain limits (RMSE generally below 2 °C) without, at least not apparent, systematic and spatial pattern. The estimation of the extreme temperatures produces results with biases comparable to the biases of the mean temperature, which makes the proposed method applicable for certain cases.
Early Silurian Benthic Foraminifera from Saudi Arabia - including the oldest known multichambered lituolids
Authors: Kaminski Michael A. , Perdana Pramudya R. D.
Published: March 2021

ABSTRACT: A diverse assemblage of early Silurian agglutinated foraminifera is described from the transitional facies between the Qusaiba and Sharawra Formations of theQalibah Group of Saudi Arabia. The agglutinated foraminiferal assemblage consists of 73 species belonging to 24 genera, and is found in in dark graptolite-bearing claystone of Aeronian age. The assemblage is highly diverse compared with coeval early Silurian assemblages reported from Europe and North America. The assemblage is comprised mainly of species belonging to the monothalamid genera Saccammina, Psammosphaera, Lagenammina, Thurammina, Thuramminoides, Amphitremoida, Bathysiphon, Rhabdammina, and the tubothalamid genera Hyperammina, Tolypammina and Turritellella. The new species Thuramminoides ellipsoidalis n. sp. is described herein, but many of the species left in open nomenclature are also likely to be new. The assemblage also includes rare specimens belonging to the globothalamid (lituolid) genera Ammobaculites and Simobaculites. This new finding revises our understanding of the early evolution of the multichambered globothalamid foraminifera. Although the simple multichambered with rectilinear chamber arrangement are known from the Ordovician, our new findings show that the coiled globothalamids belonging to the order Lituolida are older than previously thought, and were already present in Gondwana by about 440 Ma.
Benthic foraminiferal assemblages from maximum flooding surface J30, Middle Jurassic Dhruma Formation, Central Saudi Arabia
Authors: Kaminski Michael A. , Amao Abduljamiu O. , Babalola Lamidi O. , Balc Ramona , Chan Septriandi A. , Gull Hafiz M. , Khamsin Ali Bu , Malik Muhammad H.
Published: March 2021

ABSTRACT: The benthic foraminiferal have been studied from mudstone-wackestones of the D5 Unit of the Dhruma Formation that represent the Middle Jurassic J30 maximum flooding surface of Sharland et al. (2001). The benthic assemblage consists of a mixture of smaller agglutinated species, Haplophragmoides, Kutsevella, Sculptobaculites, Trochammina), and calcareous species (Nautiloculina, nodosariids, ophthalmidiids, polymorphinids, and spirillinids) without any larger foraminifera. The assemblage is indicative of open-marine midshelf conditions, and contains a number of cosmopolitan taxa that are known from the Middle Jurassic in other areas of the Tethys. The recovery of open-marine and cosmopolitan smaller benthic foraminifera in the D5 Unit of the Dhruma Formation provides a new tool for identifying the J30 maximum flooding surface and correlating the interval with other regions of the Tethys.