Special Vector Research Articles

A note on closed vector fields

<abstract><p>Special vector fields, such as conformal vector fields and Killing vector fields, are commonly used in studying the geometry of a Riemannian manifold. Though there are Riemannian manifolds, which do not admit certain conformal vector fields or certain Killing vector fields, respectively. Closed vector fields exist in abundance on each Riemannian manifold. In this paper, we used closed vector fields to study the geometry of the Riemannian manifold. In the first result, we showed that a compact Riemannian manifold $ (M^{n}, g) $ admits a closed vector field $\boldsymbol{\omega }$ with $ \mathrm{div} \boldsymbol{\omega }$ non-constant and an eigenvector of the rough Laplace operator, the integral of the Ricci curvature $ Ric(\boldsymbol{\omega }, \boldsymbol{\omega }) $ has a suitable lower bound that is necessarily isometric to $ S^{n}(c) $ and that the converse holds. In the other result, we found a characterization of an Euclidean space using a closed vector field $\boldsymbol{\omega }$ with non-constant length that annihilates the rough Laplace operator and squared length of its covariant derivative that has a suitable upper bound. Finally, we used the closed vector field provided by the gradient of the non-trivial solution of the Fischer-Marsden equation on a complete and simply connected Riemannian manifold $ (M, g) $ and showed that it is necessary and sufficient for $ (M, g) $ to be isometric to a sphere and that the squared length of the covariant derivative of this closed vector field has a suitable upper bound.</p></abstract>

Viral Vectors for Gene Therapy Get the Industrial Design Treatment

Genetic Engineering & Biotechnology NewsVol. 42, No. 12 Special ReportViral Vectors for Gene Therapy Get the Industrial Design TreatmentNew capsid designs and platform technologies are enhancing the safety, efficacy, and overall manufacturability of viral vectorsGareth John MacdonaldGareth John MacdonaldSearch for more papers by this authorPublished Online:9 Dec 2022https://doi.org/10.1089/gen.42.12.16AboutSectionsView articleView Full TextPDF/EPUB Permissions & CitationsPermissionsDownload CitationsTrack CitationsAdd to favorites Back To Publication ShareShare onFacebookTwitterLinked InRedditEmail View articleFiguresReferencesRelatedDetails Volume 42Issue 12Dec 2022 Information© 2022 by GEN PublishingTo cite this article:Gareth John Macdonald.Viral Vectors for Gene Therapy Get the Industrial Design Treatment.Genetic Engineering & Biotechnology News.Dec 2022.43-45.http://doi.org/10.1089/gen.42.12.16Published in Volume: 42 Issue 12: December 9, 2022PDF download

Approximation algorithms for a virtual machine allocation problem with finite types

We study the virtual machine allocation (VMA) problem with physical machines (PMs) of identical configuration and virtual machines (VMs) of a constant number of types. Only CPU and memory (MEM) resources are considered, so it is a special two-dimensional vector bin packing (2-DVBP) problem. Applying the best fit heuristic, we develop a fast online algorithm, which uses 209OPT(L)+1 PMs at most, where OPT(L) is the optimal value. According to the limited types of VMs, the progress of combining VMs and dividing the PMs' capacity contributes to a linear-time offline algorithm that uses 109OPT(L)+2 PMs. It outperforms the state-of-the-art (1.405+ϵ)-asymptotic approximation algorithm for the general 2-DVBP problem. These ideas can be extended to develop fast and practical algorithms.

Simplified Universal Fault-Tolerant Direct Torque Control of FPFTPM Motor With Steady-Healthy Design Under Open-Circuit Fault

A simplified universal fault-tolerant direct torque control (FTDTC) strategy of five-phase fault-tolerant permanent magnet (FPFTPM) motors under various open-circuit faults is presented in this article. In the proposed FTDTC strategy, the fault-tolerant currents are derived from the fault-tolerant mechanism analysis and steady-healthy design. The problems of existing FTDTC strategies that need to change coordinate transformation and add extra voltage compensation can be overcome. Thus, the minimal control drive system reconfiguration under different faults can be realized in the real sense. Especially, the steady-healthy controller is designed to suppress the torque ripples and achieve the high-quality torque given even under fault operation conditions; then, it is not necessary to set a special voltage vector or add a PI controller. Furthermore, the FTDTC strategy is improved to be realized under the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dq</i> coordinate system based on the flux adaption. Hence, the reduced <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</i> -axis current under different operating conditions, including fault conditions, can be ensured. This FTDTC strategy without any control reconfiguration is proposed under the premise of ensuring good performance during both healthy and fault operations. Finally, the simulation and experimental results for an FPFTPM prototype are offered to verify the feasibility of the proposed strategy.

Novel direct algorithm for computing simultaneous all-level reliability of multistate flow networks

Different types of networks, such as, Internet of Things, social networks, wireless sensor networks, transportation networks, and 4g/5G serve to benefit and help our daily lives. The multistate flow network (MFN) is used to model the network structures and applications. The level d reliability, Rd, of the MFN is the success probability of sending at least d units of integer flow from the nodes 1 to n and is a popular index for designing, managing, controlling, and evaluating MFNs. The traditional indirect algorithms must have all d-MPs (special connected vectors) or (d-1)-MCs (special disconnected vectors) first, and then use inclusion-exclusion technique (IET) or sum-of-disjoint product (SDP) in terms of found d-MPs or (d-1)-MCs to calculate Rd. The above four procedures are all NP-Hard and #P-Hard and cannot calculate Rd for d = 1, 2, …, dMAX simultaneously, that is, they can only calculate R1, R2, …, and RdMAX sequentially. Thus, in this study a novel algorithm is proposed to calculate the Rd directly for all d simultaneously, eliminating the need of using the above four procedures. The time complexity and demonstration of the proposed algorithm were analyzed with suitable examples. Furthermore, an experiment was conducted on 12 benchmark networks to validate the proposed algorithm.

Color from within: A new vector in the studies of urban coloristics

The most important feature of modern studies of urban coloristics is a special vector of viewing: not “from above”, but “from within”, “from a close distance”, from the perspective of a citizen. This principle completely changes the usual research practice and requires special tools that can capture how citizens actually see urban colors, how they feel, how they remember and use peculiarities of the color environment.

Automatic Detection of Human Maxillofacial Tumors by Using Thermal Imaging: A Preliminary Study.

Traditional computed tomography (CT) delivers a relatively high dose of radiation to the patient and cannot be used as a method for screening of pathologies. Instead, infrared thermography (IRT) might help in the detection of pathologies, but interpreting thermal imaging (TI) is difficult even for the expert. The main objective of this work is to present a new, automated IRT method capable to discern the absence or presence of tumor in the orofacial/maxillofacial region of patients. We evaluated the use of a special feature vector extracted from face and mouth cavity thermograms in classifying TIs against the absence/presence of tumor (n = 23 patients per group). Eight statistical features extracted from TI were used in a k-nearest neighbor (kNN) classifier. Classification accuracy of kNN was evaluated by CT, and by creating a vector with the true class labels for TIs. The presented algorithm, constructed from a training data set, gives good results of classification accuracy of kNN: sensitivity of 77.9%, specificity of 94.9%, and accuracy of 94.1%. The new algorithm exhibited almost the same accuracy in detecting the absence/presence of tumor as CT, and is a proof-of-principle that IRT could be useful as an additional reliable screening tool for detecting orofacial/maxillofacial tumors.

Nonlinear Generation of Perfect Vector Beams in Ultraviolet Wavebands

Perfect vector beams are a class of special vector beams with invariant radius and intensity profiles under changing topological charges. However, with the limitation of current devices, the generation of these vector beams is limited in the visible and infrared wavebands. Herein, we generate perfect vector beams in the ultraviolet region assisted by nonlinear frequency conversion. Experimental and simulation results show that the radius of the generated ultraviolet perfect vector beams remains invariant and is thus independent of the topological charge. Furthermore, we measure the power of the generated ultraviolet perfect vector beams with the change of their topological charges. This study provides an alternative approach to generating perfect vector beams for ultraviolet wavebands and may promote their application to optical trapping and optical communication.

Proper efficiency in linear fractional vector optimization via Benson's characterization

Linear fractional vector optimization problems are special non-convex vector optimization problems. They were introduced and first studied by E.U. Choo and D.R. Atkins in the period 1982–1984. This paper investigates the properness in the sense of Geoffrion of the efficient solutions of linear fractional vector optimization problems with unbounded constraint sets. Sufficient conditions for an efficient solution to be Geoffrion's properly efficient solution are obtained via Benson's characterization [An improved definition of proper efficiency for vector maximization with respect to cones. J Math Anal Appl. 1979;71:232–241] of Geoffrion's proper efficiency.

Sensor Selection for Optimal Target localization with 3-D Angle of Arrival Estimation in Underwater Wireless Sensor Networks

This paper investigates a sensor selection scheme for optimal target localization with three-dimensional (3-D) Angle of Arrival (AOA) estimation in Underwater Wireless Sensor Networks (UWSN). Specifically, we present a new 3-D AOA-based localization measurement model, which considers correlated noises and Gaussian priors. The trace of Cramer–Rao lower bound (CRLB) for the 3-D AOA measurement model is derived by introducing a special vector to denote the selected sensors with the azimuth and elevation angle measurements. Based on the presenting expressions of the CRLB, we formulate the sensor selection problem as an optimization problem, which has been transformed into the semidefinite problem program by convex relaxation, and a randomization method is adopted to improve the quality of the SDP solution. Simulation results illustrate that the proposed method receives better estimation performance over the reference methods and approaches the exhaustive search method.

Harmonic sections of vector bundles with spherically symmetric metrics

Abstract We equip an arbitrary vector bundle over a Riemannian manifold, endowed with a fiber metric and a compatible connection, with a spherically symmetric metric (cf. [4]), and westudy harmonicity of its sections firstly as smooth maps and then as critical points of the energy functional with variations through smooth sections.We also characterize vertically harmonic sections. Finally, we give some examples of special vector bundles, recovering in some situations some classical harmonicity results.

Some results on a-cosympletic manifolds

In this paper, we deal with some geometric properties of an -cosymplectic manifold. First, we give some classi cations for an alpha-cosymplectic manifold endowed with some special vector elds such as projective, concircular and torse-forming. Then, we study alpha-cosymplectic manifold admitting eta-Ricci solitons with projective, a ne conformal vector elds. Finally, we obtain some haracterizations for such a manifold to be Einstein, eta-Einstein, cosymplectic.

Generalized Methodology Application for System Design

The design process for analogue circuit design is formulated on the basis of the optimum control theory. The artificially introduced special control vector is defined for the redistribution of computational costs between network analysis and parametric optimization. This redistribution minimizes computer time. The problem of the minimal-time network design can be formulated in this case as a classical problem of the optimal control for some functional minimization. There is a principal difference between the new approach and before elaborated methodology. This difference is based on a higher level of the problem generalization. In this case the structural basis of design strategies is more complete and this circumstance gives possibility to obtain a great value of computer time gain. Numerical results demonstrate the effectiveness and prospects of a more generalized approach to circuit optimization. This approach generalizes the design process and generates an infinite number of the different design strategies that will serve as the structural basis for the minimal time algorithm construction. This paper is advocated to electronic systems built with transistors. The main equations for the system design process were elaborated.

Derivations of Vector Area and Volume Elements in Curved Coordinate Systems for Flux Vector Fields Helping Eye Disease

Our aim in this paper is to interest retinal eye specialists in preventing dry macula degeneration by a special flurry vector field through open or closed curved surfaces. The flux of vector fields through surfaces is based on vector element area and volume element. Therefore, we explain a few geometrical derivations of area and volume elements in curved orthogonal coordinate systems. We hope that by derivation of a spatial vector field flurry against drusen through open or closed surfaces due to the Gauss theorem might select drusen under eye retina cells without destroying the cells and prevent macula degeneration. A changed flurry of a magnetic or electric vector field through a closed line causes an electric or magnetic vector field on the surface closed by the line. We also hope that derivation by Stokes’ and Greens’ theorems, with the help of iron, might help eye cells to get in life.

Circuit Optimization Study According to the Maximum Principle

The minimization of the processor time of designing can be formulated as a problem of time minimization for transitional process of dynamic system. A special control vector that changes the internal structure of the equations of optimization procedure serves as a principal tool for searching the best strategies with the minimal CPU time. In this case a well-known maximum principle of Pontryagin is the best theoretical approach for finding of the optimum structure of control vector. Practical approach for realization of the maximum principle is based on the analysis of behavior of a Hamiltonian for various strategies of optimization. The possibility of applying the maximum principle to the problem of optimization of electronic circuits is analyzed. It is shown that in spite of the fact that the problem of optimization is formulated as a nonlinear task, and the maximum principle in this case isn't a sufficient condition for obtaining a minimum of the functional, it is possible to obtain the decision in the form of local minima. The relative acceleration of the CPU time for the best strategy found by means of maximum principle compared with the traditional approach is equal two to three orders of magnitude.

Observer-invariant time derivatives on moving surfaces

Observer-invariance is regarded as a minimum requirement for an appropriate definition of time derivatives. We derive various time derivatives systematically from a spacetime setting, where observer-invariance is a special case of a covariance principle and covered by Ricci-calculus. The analysis is considered for tangential n-tensor fields on moving surfaces and provides formulations which are applicable for numerical computations. For various special cases, e.g., vector fields (n=1) and symmetric and trace-less tensor fields (n=2) we compare material and convected derivatives and demonstrate the different underlying physics.

The field-theoretical methods in Lovelock gravity

The field-theoretical methods are used to construct conserved currents and related superpotentials for perturbations on arbitrary backgrounds in the Lovelock gravity. The perturbations are considered as a dynamic field configuration propagating in a given spacetime. The field-theoretical formalism is exact (without approximations) and equivalent to the original metric theory. As Lagrangian based formalism, it allows us to apply the Noether theorem. As a result, we construct conserved currents and superpotentials, where we use arbitrary displacement vectors, not only the Killing ones or other special vectors. The developed formalism is checked in calculating mass of the Schwarzschild-anti-de Sitter (AdS) black hole. The new formalism is adopted to the case of a so-called pure Lovelock gravity, where in the Lagrangian only a one polynomial in Riemannian tensor presents. We construct conserved charges and currents for static and dynamic black holes of the Vaidya type with AdS, dS and flat asymptotics. New properties of the solutions under consideration have been found. The more results are discussed. The first section in your paper

On Generalized Recurrent and Generalized Concircularly Recurrent Weyl Manifolds

In the present work, generalized recurrent and generalized concircularly recurrent Weyl manifolds are examined. We define nearly quasi-Einstein Weyl manifolds and we proved that if a generalized recurrent or generalized concircularly recurrent Weyl manifold admits a special concircular vector field, then the manifold reduces to a nearly quasi-Einstein Weyl manifold. Also, some other results are presented.

SOME VECTORS FIELDS ON THE TANGENT BUNDLE WITH A SEMI-SYMMETRIC METRIC CONNECTION

Let $M$ is a (pseudo-)Riemannian manifold and $TM$ be its tangent bundlewith the semi-symmetric metric connection $\overline{\nabla }$. In thispaper, we examine some special vector fields, such as incompressible vectorfields, harmonic vector fields, concurrent vector fields, conformal vectorfields and projective vector fields on $TM$ with respect to thesemi-symmetric metric connection $\overline{\nabla }$ and obtain someproperties related to them.

USING A NONVIRAL AND NONINTEGRATING DNA VECTOR TO GENERATE SAFE CAR-T CELLS

CAR-T cell therapy has proven its importance in cancer treatment and currently there are five approved products on the market. However, these products are based on viral vectors, which presents a risk of insertional mutagenesis, it can also be immunogenic and its manufacture is extremely expensive. The development of a nonviral vector, suitable for an efficient and stable transfection of NK and T cells is the goal of this study. In this study we use a special episomal vector (extrachromosomal vectors) with i) scaffold/matrix attachment region (S/MAR) motifs that can actively mediate the episomal maintenance, ii) a plasmid replication enhancer, the replication-Initiation Region (IR) from the β-globin locus (pEP-IR) and iii) a CAR anti CD19 (pEP-IR-CAR). We electroporated activated and non-activated T cells and NK cells with different plasmid concentrations. We evaluated transfection efficiency and viability. Our findings showed that unstimulated T cells are transfected more efficiently than activated T cells. Transfection of unstimulated T cells with 20 ug of supercoiled pEP-IR-GFP plasmid reached 22 to 63% of GFP and viability around 54% depending on the culture condition used after electroporation (FBS% and IL2). We then accessed the efficacy of pEP-IR-CAR and CAR expression, confirmed in 3,2% of the cells with 89% of viability. Cells expressing CAR on their surface were marked with anti-CAR antibody Biotin-SP-conjugated and selected by anti-Biotin microbeads, achieving an enrichment of 54,9% CAR+ cells. Our results showed that we established an optimized protocol resulting in an acceptable transfection efficiency and the transfected cells can be selected. So, the next step is to perform in vitro cytotoxicity and in vivo assays with the episomal CAR+ cells. Financially supported by FAPESP 2020/09206-4, FAPESP 2019/25309-0, CTC Center for Cell-based Therapy (FAPESP 2013/08135-2), and National Institute of Science and Technology in Stem Cell and Cell Therapy (CNPq 573754-2008-0 and FAPESP 2008/578773).