Culture and genomic analysis of Symbiopectobacterium purcellii, gen.nov. sp. nov., isolated from the leafhopper Empoasca decipiens

Bacterial endosymbionts are found in multiple arthropod species, where they play crucial roles as nutritional symbionts, defensive symbionts or reproductive parasites. Recent work has highlighted a new clade of heritable microbes within the gammaproteobacteria that enter into both obligate and facultative symbioses, with an obligately required unculturable symbiont recently given the name Cand. Symbiopectobacterium. In this study, we describe a culturable rod shaped non-flagellated bacterial symbiont from this clade isolated from the leafhopper Empoasca decipiens. The symbiont is related to the transovarially-transmitted 'BEV' bacterium that was first isolated from the leafhopper Euscelidius variegatus by Alexander Purcell, and we therefore name the symbiont Symbiopectobacterium purcellii sp. nov. gen. nov. We further report the closed genome sequence for S. purcellii. The genome is atypical for a heritable microbe, being large in size, without profound AT bias and with little evidence of pseudogenization. The genome is predicted to encode Type II, III and VI secretion systems and associated effectors and a non-ribosomal peptide synthase array likely to produce bioactive small molecules. Predicted metabolism is more complete than for other symbionts in the Symbiopectobacterium clade, and the microbe is predicted to synthesize a range of B vitamins. However, Biolog plate analysis indicate metabolism is depauperate compared to the sister clade, represented by Pectobacterium carotovorum. A quorum-sensing pathway related to that of Pectobacterium spp. (containing an overlapping expI-expR1 pair in opposite directions and a "solo" expR2) is evidenced, and LC-MS/MS analysis reveals the presence of 3-hydroxy-C10-HSL as the sole N-acylhomoserine lactone (AHL) in our strain. This AHL profile is profoundly divergent from that of other Erwinia and Pectobacterium spp., which produce mostly 3-oxo-C6- and 3-oxo-C8-HSL and could aid group identification. Thus, this microbe denotes one that has lost certain pathways associated with a saprophytic lifestyle but represents an important baseline against which to compare other members of the genus Symbiopectobacterium that show more profound integration into host biology.

Composite plate analysis made in an unsymmetric configuartion

The work presents a thin-walled plate element with the central rectangular cut-out which can be use as an elastic or load-bearing element. Plates were made of carbon epoxy laminate and subjected to uniform compression. Plates were simply supported on shorter edges, and loaded axial load. The study included analysis of the critical and weakly post-critical behavior using experimental and numerical methods. Numerical analysis was performed with using linear analysis of eigenvalue problem to determination critical loads. The second step connected nonlinear analysis of structure with initiated geometrically imperfection corresponding to the flexural-torsional buckling mode of the plate. To the numerical calculations the commercial ABAQUS program was used.

Analytical Study of Bending Characteristics of an Elastic Rectangular Plate using Direct Variational Energy Approach with Trigonometric Function

In this paper, an analytical three-dimensional (3D) bending characteristic of an isotropic rectangular thick plate with all edges simply supported (SSSS) and carrying uniformly distributed transverse load using the energy technique is presented. The three-dimensional constitutive relations which involves six stress components were used in the established, refined shear deformation theory to obtain a total potential energy functional. This theory obviates application of the shear correction factors for the solution to the problem. The governing equation of a thick plate was obtained by minimizing the total potential energy functional with respect to the out of plane displacement. The deflection functions which are in form of trigonometric were obtained as the solution of the governing equation. These deflection functions which are the product of the coefficient of deflection and shape function of the plate were substituted back into the energy functional, thereafter a realistic formula for calculating the deflection and stresses were obtained through minimizations with respect to the rotations and deflection coefficients. The values of the deflections and stresses obtained herein were tabulated and compared with those of previous 3D plate theory, refined plate theories and, classical plate theory (CPT) accordingly. It was observed that the result obtained herein varied more with those of CPT and RPT by 25.39% and 21.09% for all span-to-thickness ratios respectively. Meanwhile, the recorded percentage differences are as close as 7.17% for all span-to-thickness ratios, when compared with three dimensional plate analysis. This showed that exact 3D plate theory is more reliable than the shear deformation theory which are quite coarse for thick plate analysis. Doi: 10.28991/esj-2021-01320 Full Text: PDF

Outcome after Modified Maquet Procedure in dogs with unilateral cranial cruciate ligament rupture: Evaluation of recovery limb function by use of force plate gait analysis

Introduction Cranial cruciate ligament failure is one of the principal causes of canine lameness. Several surgical procedures were proposed to achieve joint stabilisation; among these, the Modified Maquet Procedure involves using a titanium foam wedge to achieve and maintain the tibial tuberosity advancement. The force-plate analysis provides to objectively assess normal and abnormal gait and the outcome of different surgical techniques. The study evaluates the outcome of limbs that underwent Modified Maquet Procedure using land-force plate analysis comparing the operated limb with its healthy contralateral one as a control. Materials and methods Thirty-five dogs with unilateral cranial cruciate ligament rupture were evaluated. Outcome after surgery was assessed by orthopaedic and radiographic evaluations and force plate gait analysis performed before surgery, at 15, 30 and 90 days after surgery. For objective comparison of ground reaction forces, data of operated limb were compared to contralateral limb on each time control and Symmetry Index at 90 days was determined. Healing radiographic signs, minor and major complication were reported. Results A significant improvement in ground reaction forces was reached in all the treated limbs between set time intervals. The median percentage increase in ground reaction forces was constant from 15 to 90 days, with a Symmetry Index >9 in 54.2% of patients suggesting a normal gait symmetry. A complete bone healing was noticed at 90 days follow-up radiographic assessment. We experienced three major (8.5%) and one minor (2.8%) complications. Conclusions To the Authors’ knowledge, this is the first study in the veterinary literature that assessed outcomes of dogs undergoing Modified Maquet Procedure for the treatment of cranial cruciate ligament rupture using force plate gait analysis and healthy contralateral limb as a control group. Our results confirm that Modified Maquet Procedure is an effective method to stabilise the stifle joint.

Biomechanics of running: An overview on gait cycle

This review article summarized the literature regarding running gait. It describes characteristics of running gait and running gait cycle, explains running anatomy in relation to lower and upper body mechanism; contribution of muscles, and joint running gait cycle. The concept of running kinematics and kinetics has described motion characteristics such as position, velocity, acceleration, and force applied during the running cycle. Running gait analysis techniques has discussed such as motion analysis, force plate analysis, and electromyography.

About the B-spline wavelet discrete-continual finite element method of the local plate analysis

Introduction. This distinctive paper addresses the local semi-analytical solution to the problem of plate analysis. Isotropic plates featuring the regularity (constancy) of physical and geometric parameters (modulus of elasticity of the plate material, Poisson’s ratio of the plate material, dimensions of the cross section of the plate) along one direction (dimension) are under consideration. This direction is conventionally called the basic direction. Materials and methods. The B-spline wavelet discrete-continual finite element method (DCFEM) is used. The initial operational formulation of the problem was constructed using the theory of distribution and the so-called method of extended domain, proposed by Prof. Alexander B. Zolotov. Results. Some relevant issues of construction of normalized basis functions of the B-spline are considered; the technique of approximation of corresponding vector functions and operators within DCFEM is described. The problem remains continual if analyzed along the basic direction, and its exact analytical solution can be obtained, whereas the finite element approximation is used in combination with a wavelet analysis apparatus in respect of the non-basic direction. As a result, we can obtain a discrete-continual formulation of the problem. Thus, we have a multi-point (in particular, two-point) boundary problem for the first-order system of ordinary differential equations with constant coefficients. A special correct analytical method of solving such problems was developed, described and verified in the numerous papers of the co-authors. In particular, we consider the simplest sample analysis of a plate (rectangular in plan) fixed along the side faces exposed to the influence of the load concentrated in the center of the plate. Conclusions. The solution to the verification problem obtained using the proposed version of wavelet-based DCFEM was in good agreement with the solution obtained using the conventional finite element method (the corresponding solutions were constructed with and without localization; these solutions almost completely coincided, while the advantages of the numerical-analytical approach were quite obvious). It is shown that the use of B-splines of various degrees within wavelet-based DCFEM leads to a significant reduction in the number of unknowns.

AXENIC CULTURE OF PHILONOTIS FALCATA (HOOK.) MITT., AN ALTERNATIVE TO REDUCE THE IMPACT OF LARGE-SCALE COLLECTION FROM NATIVE HABITAT

Axenic culture of Philonotis falcata, collected from Idukki district of Kerala was established. Spores were surface sterilized in sodium dichloroisocyanurate (NaDCC) and inoculated into half strength Hoagland’s Basal media of pH 6.0. The inoculated tubes were incubated at 25°C at 18h light, 6h dark cycle for 30 days. The protonema developed were transferred to 30 ml fresh half strength media in conical flasks with different pH and kinetin concentrations and incubated for 45 days. Gametophyte proliferation, growth pattern and photosynthetic pigment content were estimated. Among the various media composition, pH5.0 with 0.5 mg/L kinetin supported maximum bud proliferation and growth. Pigment production was higher at pH 6.0, 0.5 mg/L kinetin. There seem to have interaction between pH and kinetin in growth, biomass production and pigment production. TLC plate analysis revealed similar banding pattern between wild and in vitro plant metabolites, indicating the possibility of using axenic plants in extraction of bioactive compounds thereby reducing the impact of collection from native habitat