Dual Vector Research Articles

High Fat Diet Suppresses Energy Expenditure Via Neurons in the Brainstem

Oxidation of fat by brown adipose tissue (BAT) contributes to energy balance and heat production. During cold exposure, BAT thermogenesis produces heat to warm the body. Obese subjects and rodents, however, show impaired BAT thermogenesis to the cold. Our previous studies suggest that vagal afferents synapsing in the nucleus tractus solitarius (NTS), tonically inhibit BAT thermogenesis to the cold in obese rats. NTS neurons send projections to the dorsal aspect of the lateral parabrachial nucleus (LPBd), which is a major integrative center that receives warm afferent inputs from the periphery and promotes inhibition of BAT thermogenesis. This study investigated the contribution of LPBd neurons in the impairment of BAT thermogenesis in rats fed a high-fat diet (HFD). By using a targeted dual viral vector approach, we found that chemogenetic activation of an NTS-LPB pathway inhibited BAT thermogenesis to the cold. We also found that the number of Fos-labelled neurons in the LPBd was higher in rats fed a HFD than in chow diet-fed rats after exposure to a cold ambient temperature. Nanoinjections of a GABAA receptor agonist into the LPBd area rescued BAT thermogenesis to the cold in HFD rats. These data reveal the LPBd as a critical brain area that tonically suppresses energy expenditure in obesity during skin cooling. These findings reveal novel effects of high-fat diets in the brain and in the control of metabolism and can contribute to the development of therapeutic approaches to regulate fat metabolism.

Mucosal and systemic neutralizing antibodies to norovirus induced in infant mice orally inoculated with recombinant rotaviruses

Rotaviruses (RVs) preferentially replicate in the small intestine and frequently cause severe diarrheal disease, and the following enteric infection generally induces variable levels of protective systemic and mucosal immune responses in humans and other animals. Rhesus rotavirus (RRV) is a simian RV that was previously used as a human RV vaccine and has been extensively studied in mice. Although RRV replicates poorly in the suckling mouse intestine, infection induces a robust and protective antibody response. The recent availability of plasmid only-based RV reverse genetics systems has enabled the generation of recombinant RVs expressing foreign proteins. However, recombinant RVs have not yet been experimentally tested as potential vaccine vectors to immunize against other gastrointestinal pathogens invivo. This is a newly available opportunity because several live-attenuated RV vaccines are already widely administered to infants and young children worldwide. To explore the feasibility of using RV as a dual vaccine vector, we rescued replication-competent recombinant RRVs harboring bicistronic gene segment 7 that encodes the native RV nonstructuralprotein 3 (NSP3) protein and a human norovirus (HuNoV) VP1 protein or P domain from the predominant genotype GII.4. The rescued viruses expressed HuNoV VP1 or P protein in infected cells invitro and elicited systemic and local antibody responses to HuNoV and RRV following oral infection of suckling mice. Serum IgG and fecal IgA from infected suckling mice bound to and neutralized both RRV and HuNoV. These findings have encouraging practical implications for the design of RV-based next-generation multivalent enteric vaccines to target HuNoV and other human enteric pathogens.

PXOOY: A dual-function vector for expression of membrane proteins in Saccharomyces cerevisiae and Xenopus laevis oocytes.

On the quest for solving structures of membrane proteins by X-ray crystallography or cryo-EM, large quantities of ultra-pure protein are a paramount prerequisite. Obtaining enough protein of such high standard is not a trivial task, especially for difficult-to-express membrane proteins. Producing membrane protein for structural studies is often performed in Escherichia coli or Saccharomyces cerevisiae and is frequently complemented with functional studies. Ion channels and electrogenic receptors are traditionally studied in terms of their electrophysiological behavior, which cannot be performed in neither E. coli nor yeast. Therefore, they are frequently characterized in mammalian cells or in Xenopus laevis oocytes. To avoid generating two different plasmids, we here describe the construction of a dual-function plasmid, pXOOY, for membrane protein production in yeast and for electrophysiology in oocytes. pXOOY was constructed such that all elements required for oocyte expression were copied from the dual Xenopus-mammalian vector pXOOM and meticulously introduced into the high-yield yeast expression vector pEMBLyex4. pXOOY is thus designed to preserve the high yield of protein from pEMBLyex4 while simultaneously permitting in vitro transcription for expression in oocytes. We evaluated the performance of pXOOY by comparing expression of two yeast codon optimized human potassium channels, ohERG and ohSlick (Slo2.1) from pXOOY to expression of these channels obtained from the reference vectors pEMBLyex4 and pXOOM. Our proof-of-concept study indicates that accumulation in PAP1500 yeast cells was higher when the channels were expressed from pXOOY, which was verified both qualitatively and quantitatively. Two-electrode voltage clamp measurements in oocytes showed that the pXOOY constructs encoding ohERG and ohSlick gave currents with full preservation of electrophysiological characteristics. Our results show that it is possible to design a dual-function Xenopus-yeast vector without compromising expression in yeast and simultaneously maintaining channel activity in oocytes.

Low complexity VLSI architecture for improved primal–dual support vector machine learning core

Support Vector Machine (SVM) is an efficient classification tool providing good accuracy and reliability. The primal–dual method is an interior-point method for SVM training with considerable scalability and accuracy. In this paper, an improved primal–dual method for SVM learning is proposed. The proposed primal–dual method offers faster convergence of the SVM learning core by up to 25%, which is made possible by reducing the number of iterations required for obtaining the optimal solution while maintaining its accuracy. We also propose a low-complexity pipelined very large scale integration (VLSI) architecture for implementing the improved primal–dual method both on field-programmable gate array (FPGA) and 65 nm application specific integrated circuit (ASIC) platforms. The computational complexity of the proposed VLSI architecture is independent of the size of the training data and the feature vector.

Efficacy, pharmacokinetics, and safety in the mouse and primate retina of dual AAV vectors for Usher syndrome type 1B

Gene therapy of Usher syndrome type 1B (USH1B) due to mutations in the large Myosin VIIA (MYO7A) gene is limited by the packaging capacity of adeno-associated viral (AAV) vectors. To overcome this, we have previously developed dual AAV8 vectors which encode human MYO7A (dual AAV8.MYO7A). Here we show that subretinal administration of 1.37E+9 to 1.37E+10 genome copies of a good-manufacturing-practice-like lot of dual AAV8.MYO7A improves the retinal defects of a mouse model of USH1B. The same lot was used in non-humanprimates at doses 1.6× and 4.3× the highest dose proposedfor the clinical trial which was based on mouse efficacy data. Long-lasting alterations in retinal function and morphology were observed following subretinal administration of dual AAV8.MYO7A at the high dose. These findings were modest and improved over time in the low-dose group, as also observed in other studies involving the use of AAV8 in non-human primates and humans. Biodistribution andshedding studies confirmed the presence of vector DNA mainly in the visual pathway. Accordingly, we detected human MYO7A mRNA expression predominantly in the retina. Overall, these studies pave the way for the clinical translation of subretinal administration of dual AAV vectors in USH1B subjects.

Experimental study of single-shot polarization dynamics of dual dissipative solitons

The state of polarization provides an additional dimension to the pulse dynamics of dissipative solitons. However, due to lack of appropriate measuring instruments, the polarization evolution of dual pulse vector solitons is still unclear. Here, for an erbium-doped fiber laser mode-locked with carbon nanotubes, we characterize the single-shot polarization evolution of dual dissipative solitons in detail using a high-speed wave-resolved measurement technique. For the different birefringence distributions in the laser cavity, the coupling between the orthogonal components of the vector soliton has a great influence on its physical properties, which may lead to various physical images of the vector soliton. We observed typical polarization-locked vector solitons and polarization attractors in the dual soliton pulses. We also observed that the polarization dynamics of the lead and tail vector pulses have similar evolution dynamics on the Poincaré sphere, while they have a distinct phase difference. By virtue of the difference of the processing SOPs between the leading and trailing pulses, we resolve three kinds of two solitons pulses with distinct relative phase evolutions. Our results enrich the vector soliton dynamics in fiber lasers.

The Invariants of Dual Parallel Equidistant Ruled Surfaces

In this paper, we calculate the Gaussian curvatures of the dual spherical indicatrix curves formed on unit dual sphere by the Blaschke vectors and dual instantaneous Pfaff vectors of dual parallel equidistant ruled surfaces (DPERS) and we give the relationships between these curvatures. In addition to—in cases where the base curves of these DPERS are closed—computing the dual integral invariants of the indicatrix curves. Additionally, we show the relationships between them. Finally, we provide an example for each of these indicatrix curves.

A new approach to Jacobsthal, Jacobsthal-Lucas numbers and dual vectors

<abstract><p>This paper gives a detailed study of a new generation of dual Jacobsthal and dual Jacobsthal-Lucas numbers using dual numbers. Also some formulas, facts and properties about these numbers are presented. In addition, a new dual vector called the dual Jacobsthal vector is presented. Some properties of this vector apply to various properties of geometry which are not generally known in the geometry of dual space. Finally, this study introduces the dual Jacobsthal and the dual Jacobsthal-Lucas numbers with coefficients of dual numbers. Some fundamental identities are demonstrated, such as the generating function, the Binet formulas, the Cassini's, Catalan's and d'Ocagne identities for these numbers.</p></abstract>

Dual Attitude Representations and Kinematics for Six-Degree-of-Freedom Spacecraft Dynamics

This paper focuses on the development of three newly formed representations of dual attitude and their respective kinematics equations - Dual Classical Rodrigues Parameters, Dual Modified Rodrigues Parameters, Dual Principal Axis and Principal Angle (Dual Principal Rotation Vector). These three formulations are developed by building off of the theories and concepts used with Dual Quaternions and utilizing numerous attitude identities for quaternions to create new identities using dual quaternions and dual attitudes while detailing the process used throughout the derivation. The accompanying dual kinematic equations using these dual attitude parameters are also generated using their respective dual attitude coordinate systems. Furthermore, the new dual attitude representations with their respective, distinct kinematic equations and identities are validated against a simulated 6-DOF rigid body spacecraft control problem to verify equivalency across equations using the dual quaternion as a baseline.

High-Throughput IgG Reformatting and Expression Using Hybrid Secretion Signals and InTag Positive Selection Technology.

We have previously published protocols for high-throughput IgG reformatting and expression, that enable rapid reformatting of phage-displayed antibody Fab fragments into a single dual expression vector for full IgG expression in Expi293F cells (Chen et al. Nucleic Acids Res 42:e26, 2014; Chen et al. Methods in Molecular Biology, vol 1701, 2018). However, when working with phage clones from a naïve library containing highly diverse N-terminal sequences, where the 5' PCR primers bind, the PCR step can become cumbersome. To overcome this limitation, we have investigated and found that the C-terminal 7 amino acid residues of the human antibody VH1 secretion signal can be replaced with those from ompA or pelB bacterial signals to form hybrid signal sequences that can drive strong IgG expression in Expi293F cells. The use of such hybrid signals allows any Fab fragment in the library to be amplified and cloned into the IgG expression vector using only a single 5' PCR primer targeting the bacterial secretion signal of the light or heavy chain, thus dramatically simplifying the IgG reformatting workflow.

Creation of poxvirus expressing foot-and-mouth and peste des petits ruminant disease virus proteins

Foot-and-mouth disease (FMD) and Peste des petits ruminant disease (PPR) are acute and severe infectious diseases of sheep and are listed as animal diseases for compulsory immunization. However, there is no dual vaccine to prevent these two diseases. The Modified Vaccinia virus Ankara strain (MVA) has been widely used in the construction of recombinant live vector vaccine because of its large capacity of foreign gene, wide hostrange, high safety, and immunogenicity. In this study, MVA-GFP recombinant virus skeleton was used to construct dual live vector vaccines against FMD and PPR. The recombinant plasmid pUC57-FMDV P1-2A3CPPRV FH was synthesized and transfected into MVA-GFP infected CEF cells for homologous recombination. The results showed that a recombinant virus without fluorescent labeling was obtained after multiple rounds of plaque screening. The recombinant virus successfully expressed the target proteins, and the empty capsid of FMDV could be observed by transmission electron microscope (TME), and the expression levels of foreign proteins (VP1 and VP3) detected by ELISA were like those detected in FMDV-infected cells. This study laidthe foundation for the successful construction of a live vector vaccine against FMD and PPR. • A recombinant MVA expressing FMDVP12A3C and PRRV HF proteins • Both the FMDV and PRRV proteins inserted into the virus were expressed • The proteins expressed by the recombinant poxvirus were assembled into VLPs.

Crowd abnormal event detection based on motion entropy and dual support vector data description

Abnormal event detection is a popular research direction in the field of intelligent transportation and public safety. The features that characterize abnormal events are extracted from given video sequence through computer vision technology. Then the abnormal events in the video are automatically detected through the classification model. In order to describe the motion characteristics of events more accurately, a new feature based on motion entropy is proposed in this paper. The entropy value of motion pixels in the video frame is calculated as the input feature of the classification model. Motion entropy is suitable to regard as a feature to distinguish normal events from abnormal events due to the big differences between normal and abnormal events. In addition, an abnormal event detection model based on motion entropy and dual support vector data description (ME-DSVDD) is presented to solve the problem of insufficient sample diversity. The standard data set is tested to analyze the performance of the proposed model. The experimental results show that the proposed method can effectively improve the performance of the abnormal event detection model.

Construction and development of a novel dual-gene coexpression system to promote heterologous protein secretion for Streptomyces.

Streptomyces lividans is a potent host for the extracellular overproduction of heterologous proteins. To further improve the usability and productivity of S. lividans, a dual gene expression vector of "pTSKr duet" containing two strong constitutive promoters, scmpPc and kasOp*, was constructed. The success in the overproduction of two secretory enzymes simultaneously without interference with each other indicated that the "pTSKr duet" vector can realize the coexpression of two genes simultaneously and independently. Further, using the two-gene coexpression vector, we screened the effects of the overexpression of five factors that possibly promote secretion on the extracellular overproduction of heterologous secretory proteins. Interestingly, the coexpression of a quality control regulator (CssR) promoted the overproduction level to 1.3-fold for a stable heterologous protein of SMTG (transglutaminase from S. mobaraensis), while other four factors limited the overproduction of SMTG at different degrees.

The graphs of non-degenerate linear codes

We consider the Grassmann graph of k-dimensional subspaces of an n-dimensional vector space over the q-element field and its subgraph Γ(n,k)q which consists of all non-degenerate linear [n,k]q codes. We assume that 1<k<n−1. It is well-known that every automorphism of the Grassmann graph is induced by a semilinear automorphism of the corresponding vector space or a semilinear isomorphism to the dual vector space and the second possibility is realized only for n=2k. Our result is the following: if q≥3 or k≠2, then every isomorphism of Γ(n,k)q to a subgraph of the Grassmann graph can be uniquely extended to an automorphism of the Grassmann graph; in the case when q=k=2, there are subgraphs of the Grassmann graph isomorphic to Γ(n,k)q and such that isomorphisms between these subgraphs and Γ(n,k)q cannot be extended to automorphisms of the Grassmann graph.

Precise integration solutions for the static and dynamic responses of axially graded solid beams

By virtue of the scaled boundary finite element method (SBFEM), the precise integration solutions (PIS) to deflections, stresses and transverse vibration parameters of the functionally graded solid beams are provided. It is worth to note that the mechanical parameters of the graded beams are altered across the x-axis according to power-law, exponential, trigonometric or other arbitrary theories. In SBFEM, the in-homogeneous beam is simplified into the one-dimensional model and just two high-order linear spectral elements are exploited to discretize the axially non-homogeneous beam. Nevertheless, the high accuracy can be ensured. It is essential to remind that the displacement-based beam spectral element is characterized by owning only two degrees of freedom. Additionally, the changing patterns of the displacement and stress field through the transverse direction can be expressed as an analytical matrix exponent. Aided by the two-dimensional fundamental equations of elastic materials and the employed scaled boundary coordinate, the governing equation of the axially graded solid beam is derived in the form of second order ordinary differential equation. Furthermore, the stiffness matrix and PIS of displacements and stresses are acquired from evaluating the governing equation by means of the dual vector technology and precise integration methodology (PIM). Applying the kinetic energy theory constructs the mass matrix of the axially heterogeneous beam. Afterwards the PIS to natural frequencies are obtained according to solving the eigenvalue equation. Finally, numerical exercises are presented to portray the excellent agreement and fast convergence ratio of the introduced PIS and discuss influences of supported conditions, gradient exponents, length-to-thickness ratios and formulae of gradation functions on the flexural behaviors and free vibration responses of the axially graded elastic beams.

Cross-coupling relative dynamics for on-orbit assembly in rotating frame of reference

Dual numbers are applied in this paper to relative dynamics between rigid-flex combination systems. In space cooperative missions, the relative dynamic equations with engineering applicability require description in rotating frame of reference. Taking advantages of dual numbers which can represent spiral movement in a compact form with respect to the rotating frame, the dual vector, dual momentum, dual inertia operator, dual coupling coefficient operator and dual modal coordinates of flexible modules are derived. The algebra of dual numbers for rigid-flex combination system is further developed. On this basis, relative equations of motion between two rigid-flex combination systems in rotating frame of reference are proposed. The behaviors of relative dynamics present complex cross-coupling effects between attitude-orbit coupling and rigid-flex coupling. An on-orbit assembly mission of flexible modules via free flying robots is presented as an exemplary application of the cross-coupling relative dynamics. Ground testing results illustrate the cross-coupling effects on the six degree-of-freedom motion of rigid-flex combination system. Simulation results prove the engineering significance of the cross-coupling relative dynamic model.

Model Predictive Torque Control for a Dual Three-phase PMSM Using Modified Dual Virtual Vector Modulation Method

Single voltage vectors applied in the conventional model predictive torque control (MPTC) for multiphase motors do not only suffer from serious torque and stator flux ripples but also cause the large harmonic current. To address the aforementioned challenges, an MPTC using a modified dual virtual vector modulation method is proposed to improve the operational performance of a dual three-phase permanent magnet synchronous motor. Virtual voltage vectors are synthesized as the candidate control set to restrain the harmonic current. A transformation method is introduced to consider both the stator flux and torque in the duty cycle modulation. The torque and stator flux ripples are simultaneously reduced by addressing the limitations of nonuniform units. Furthermore, the null voltage vector is then inserted to expand the modulation range and improve the steady-state performance. Moreover, the sawtooth carrier is adopted to address the challenge of the asymmetric switch sequence caused by the modified modulation. Finally, the experimental results are presented to verify the effectiveness and superiority of the proposed MPTC method.

Dual Three Phase Multilevel Space Vector Modulation Control of Diode Clamped Inverter for Dual Star Induction Motor Drive

This work suggests a dual three-phase Space Vector Modulation (SVM) for the Diode Clamped Multilevel Inverter (DCMI) to ensure a robust control of Dual Star Induction Motor (DSIM). The principal scheme is investigated to apply the same control of the six-phase multilevel inverter by two three-phase multilevel inverter to drive the DSIM. The use of classic SVM control offers significant simplifications for controlling a six phase five levels inverter. The proposed control approach employs according to the hybridization of various conversion functions to establish the modulation strategy for each voltage vector and its placement in the plane of voltage modulation in distinctly and easy manner. A numerical simulation under MATLAB/Simulink is carried out to evaluate the Indirect Field Oriented Control (IFOC) of DSIM drive fed by multilevel inverters. The simulation outcomes clearly reveal good performance of the designed control strategy in terms of THD and control efficiency.

Interaction between orthogonal components of single, dual and bound state vector solitons from a fiber laser

We report the interaction between orthogonal components of three types of vector solitons which are generated in a passively mode-locked fiber laser. By adjusting pump power and cavity birefringence, single, dual and bound state vector solitons can be selectively acquired, while all the types of vector solitons reveal energy exchange phenomenon on spectral sidebands. Moreover, the numerical simulation fully reproduces the experimental results, which confirms that the soliton separation is the key parameter that determines the formation of energy exchange sidebands. These results would provide inspirations for the evolution of interaction between solitons and greatly enhance the understanding of soliton dynamics.

Long-Term Real-World Safety and Efficacy of Liver-Directed AAV Gene Therapy for Severe Hemophilia with and without Inbibitors in Privately Owned Dogs

Background Hemophilia A (HA) and hemophilia B (HB) are inherited bleeding disorders resulting from deficiency of coagulation factors VIII (FVIII) or factor IX (FIX) activity, respectively. HA and HB both occur naturally in dogs. The bleeding phenotype of severe canine HA and HB is analogous to the human patient experience with frequent spontaneous and trauma-induced bleeding. Previous studies of dogs from HA and HB colonies at research institutes have been highly informative about the safety and efficacy of adeno-associated virus (AAV) liver-directed gene therapy for HA and HB. However, these animals are housed in highly controlled environments; in contrast, pet dogs with HA or HB are exposed to real-world challenges that likely affect their bleeding phenotype and the efficacy of novel therapeutics. In this regard, privately owned dogs may better recapitulate the human patient experience. Aims To determine the real-world efficacy of liver-directed AAV gene therapy for HA/HB in privately owned canines with and without inhibitors. Methods Eleven dogs with severe HA and one dog with severe HB were treated with liver-directed AAV gene therapy with canine (c) FVIII or cFIX, as detailed in Table 1. Pre-existing neutralizing antibodies to AAV8 were detected using a luciferase-based transduction inhibition assay. Pre- and post-gene therapy annualized bleeding rates were calculated by cumulative bleeding events divided by the age at gene therapy (pre) or duration of follow-up (post). FVIII activity was determined using a chromogenic assay and FIX activity using a one-stage assay. Results All dogs had AAV8 neutralizing antibody titers ≤ 1:5 at enrollment. The HA dogs (10 males and 1 female) were treated with either dual chain vectors of cFVIII-SQ (n = 2, total dose of 5 x 1013 vg/kg) or single-chain vectors encapsidating high-expression cFVIII variants: cFVIII-ΔF (n = 2, 6x1012 vg/kg) or cFVIII-ΔF/V3 (n = 7, 5.4-9 x 1012 vg/kg). F8 genetic testing revealed intron 22 inversions (n=7), small deletion (n=2), missense (n=1) and complex mutation (n=1) all compatible with severe HA. Of note, one HA dog (PC3) had a pre-existing FVIII inhibitor which was eradicated following gene therapy. In all dogs with available data (n=10), FVIII activity is > 1% with 5 in the moderate hemophilia range and 4 in the mild range with a median FVIII activity of 3.2% (range 1.1-13.8%) after a median duration of 4.1 years (range 2.6-8.9 years). In HA dogs, the ABR post-gene therapy declined by an average of 93%. The sole HB dog carried two missense F9 mutations and was treated with wildtype cFIX at 3 x 1012 vg/kg and has been followed for 4.5 years with FIX activity of 5.7% and has had no bleeding episodes since gene therapy. Three animals have died during follow up. The previously inhibitor positive dog (PC3) died approximately 2 years after gene therapy from an unrelated cause. An HA dog (PC1) treated with dual chain vector with expression in the ~2% normal range died from a bleeding episode at 8.8 years after gene therapy. Notably, many of his bleeds were associated with real-world activities including having his legs being pulled by a toddler. A third HA dog (PC9) was euthanized 3.5 years post-gene therapy after being diagnosed with widely disseminated cancer; the details of the vector integration analysis of his tumor will be reported elsewhere. Conclusion AAV gene therapy was successful at substantially ameliorating the bleeding phenotype in both male and females dogs with > 1 year of follow-up. However, some dogs continued to have bleeding, especially animals with <5% normal cFVIII activity. One animal developed cancer after gene therapy; there were no other safety concerns. As we have described previously, liver-directed AAV gene therapy also induced immune tolerance in an HA dog with a pre-existing inhibitors. We show that AAV liver-directed gene therapy is safe and efficacious in a real-world experience of privately owned dogs with severe HA and HB. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal