Local Strain Research Articles

Molecular Study of Varicella zoster virus in Cerebrospinal Fluid from Stroke Patients of Thi-Qar province.

Varicella zoster virus (VZV) is a type of alpha-herpesvirus that specifically targets the nervous system. The initial infection, typically occurring during childhood, results in varicella (commonly known as chickenpox), after which the virus enters a dormant state in cranial nerve ganglia, dorsal root ganglia, and autonomic ganglia throughout the entire neuroaxis. Molecular and genetic studies of viruses are an important tool for virus development and identifying viral treatments to combat the diseases. The aim of the study was to determine the whole ORF4 sequence of the local VZV strains for phylogenetic analysis to determine the variability in the viral sequence. Ten samples of VZV DNA were subjected to the sequencing of the whole ORF4 region following identification using the PCR method. Sequences from five samples have been successfully analyzed. All clinical strains were discovered to possess a genome with a length of 124,884 base pairs. The sequences exhibited the occurrence of two distinct mutations, one being a transversion and the other a transition, with the latter resulting in an alteration of the amino acid. A phylogenetic tree was constructed using the maximum likelihood method based on the sequences of five nucleotide sequences from clinical samples and nine reference VZV strains. The tree displayed the evolutionary distances between these sequences. The analysis of the phylogenetic tree revealed the presence of five primary clades, with four of them originating from India (isolates S1, S2, S4, S5), while S3 exhibited similarity to a strain from the United Kingdom.

Shape reconstruction of soft continuum robots via the fusion of local strains and global poses

Shape reconstruction of soft continuum robots via the fusion of local strains and global poses

Quantitative evaluation of local strain distribution induced by deformation twins and triggering effect of deformation twinning on neighboring grains in polycrystalline AZ31 magnesium alloys

{101‾2}<1‾011> deformation twinning commonly occurs in Mg/Mg alloys. In their polycrystals, however, twinning is not always activated at locations with high Schmid factor for {101‾2}<1‾011> twinning. It is believed that twinning behavior in polycrystalline Mg/Mg alloys can be understood with a consideration of interaction between adjacent twins as well as local deformation behavior on a micro- and meso‑structural scale. In this study, we theoretically estimate local plastic strain within twins by transforming coordinates and then compare it with that experimentally obtained from digital image correlation (DIC) analysis for understanding the reason for non-Schmid twinning in polycrystalline-Mg alloys. The theoretically estimated strain of twins was found to be in good agreement with the DIC-strain value. Furthermore, it was observed that the variant selection of twin can be explained by the compatibility parameter m’, rather than Schmid factor, suggesting that twin activation in polycrystalline-Mg is strongly influenced by adjacently appeared twins.

Theoretical study on the synthetic pathway of H and N co-doped diamonds

To search for potential n-type diamonds with shallow donor energy levels and low formation energies, the reaction energies, geometries, formation energies, electronic properties of hydrogen (H) and nitrogen (N) co-doped diamond have been investigated by density functional theory (DFT) and hybrid density functional theory (HSE06). The results of the investigations on isolated H- and N-doped diamonds do not meet the criteria for shallow n-type donors, in agreement with previous findings. Subsequently, the effect of the addition of N atoms as a co-dopant with H is investigated, which varies with the H:N ratio and whether H is substitutional or interstitial. By the results of the electronic structure, it is found that only the HN4 co-doped diamond is likely to exhibit a shallow donor, with a shallow donor level of 0.147 eV and formation energy of 0.02 eV. Then, the stability of the HN4 defect is analyzed, and the HN4 defect is more stable compared to the H-N3 + N and H-N2 + N2 defects, and its decomposition energy is also very large. Further, the bond strain brought by HN4 defect is considered, showing that the local bond strain of the HN4 defect is intermediate between that of the boron (B) and N defects, which proves that the defect can be realized. Finally, a non-molecular synthetic route for the preparation of HN4 defect is proposed by combining H-N + N3V or N2 + H-N2 defects.

Internal quantum efficiency improvement of InGaN-based red LED by using double V-pits layers as strain relief layer

Micro/mini light emitting diodes (LEDs) based on AlInGaN material system have vast potential in display applications. Nevertheless, the low internal quantum efficiency (IQE) of InGaN-based red LED limits its development and application. In the epitaxial structure of our designed red LED, double V-pits layers were used as strain relief layers to reduce compressive strain and improve the IQE of the active layer. First, InGaN/GaN superlattices (SLs) were grown below the active layer to form low-density large V-pits layer. Subsequently, multi-period green and red composite quantum wells were adopted as the active layer. A high-density small V-pits layer was introduced into the active region to release the compressive strain by adjusting the growth parameters of green multiple quantum wells (MQWs). The V-shaped pits divide the continuous large-area of active layer into mutually isolated small pieces, which prevents the transmission of strain and converts the long-range strain into separated local strain. The peak IQEs of LED A2 with single V-pits layer and LED B4 with double V-pits layers were measured to be 10.5% at 613 nm and 21.5% at 612.1 nm, respectively. The IQE is greatly improved by 204.7%. The research results indicate that the double V-pits layers structure can alleviate the compressive strain of InGaN QWs more effectively, reduce the influence of piezoelectric polarization field, and improve the IQE.

Site Disorder Drives Cyanide Dynamics and Fast Ion Transport in Li6PS5CN.

Halide argyrodite solid-state electrolytes of the general formula Li6PS5 X exhibit complex static and dynamic disorder that plays a crucial role in ion transport processes. Here, we unravel the rich interplay between site disorder and dynamics in the plastic crystal argyrodite Li6PS5CN and the impact on ion diffusion processes through a suite of experimental and computational methodologies, including temperature-dependent synchrotron powder X-ray diffraction, AC electrochemical impedance spectroscopy, 7Li solid-state NMR, and machine learning-assisted molecular dynamics simulations. Sulfide and (pseudo)halide site disorder between the two anion sublattices unilaterally improves long-range lithium diffusion irrespective of the (pseudo)halide identity, which demonstrates the importance of site disorder in dictating bulk ionic conductivity in the argyrodite family. Furthermore, we find that anion site disorder modulates the presence and time scales of cyanide rotational dynamics. Ordered configurations of anions enable fast, quasi-free rotations of cyanides that occur on time scales of 1011 Hz at T = 300 K. In contrast, we find that cyanide dynamics are slow or frozen in Li6PS5CN when site disorder between the cyanide and sulfide sublattices is present at T = 300 K. We rationalize the observed differences in cyanide dynamics in the context of elastic dipole interactions between neighboring cyanide anions and local strain induced by the configurations of site disorder that may impact the energetic landscape for cyanide rotational dynamics. Through this study, we find that anion disorder plays a decisive role in dictating the extent and time scales of both lithium ion and cyanide dynamics in Li6PS5CN.

Role of prior austenite grain boundary and retained austenite in strain localization of medium-carbon high-strength steels

Exploring the micromechanical behavior of lath-martensitic quenching and tempering (Q&T), as well as quenching and partitioning (Q&P) steels presents a significant challenge due to their complex multi-phase constituents and hierarchical structures. This study conducts a comprehensive comparative analysis using medium-carbon Q&T and Q&P steels with identical chemical compositions. Atom probe tomography (APT) was used to investigate the distribution of chemical elements, while high-resolution digital image correlation (HR-DIC) provided insights into nanoscopic strain localization and partitioning. Both Q&T and Q&P steels exhibit significant strain localization at prior austenite grain boundaries (PAGBs) due to substantial carbon segregation. Strain localization in Q&T steel at PAGBs and packet boundaries strongly depends on preferred geometric orientations, with boundaries inclined 45° to the loading direction experiencing severe deformation. Conversely, in Q&P steel, PAGBs adjacent to large clusters of fine lath martensite, lacking a packet with a longitudinal direction parallel to boundaries and a feasible in-lath slip system, primarily undergo deformation. Carbon partitioning from martensite to retained austenite (RA), along with coexisting carbon and manganese segregation at phase interfaces, stabilizes the RA, resulting in a neighborhood-dependent deformation behavior of RA. The existence of RA not only absorbs carbon, maintaining low strength and high deformability, but also uniformly distributes and induces stable interfaces to hinder the formation of large packets with easily activated in-lath slip transmission.

Productive chemistry induced by mechanochemically generated macroradicals.

Large or repeated mechanical loads degrade polymeric materials by accelerating chain fragmentation. This mechanochemical backbone fracture usually occurs by homolysis of otherwise inert C-C, C-O and C-S bonds, generating highly reactive macroradicals. Because backbone fracture is detrimental on its own and the resulting macroradicals can initiate damaging reaction cascades, a major thrust in contemporary polymer mechanochemistry is to suppress it, usually by mechanochemical release of "hidden length" that dissipates local molecular strain. Here we summarize an emerging complementary strategy of channelling mechanochemically generated macroradicals in reaction cascades to form new load-bearing chemical bonds, which enables local self-healing or self-strengthening, and/or to generate mechanofluorescence, which could yield detailed quantitative molecular understanding of how material-failure-inducing macroscopic mechanical loads distribute across the network. We aim to identify generalizable lessons derivable from the reported implementations of this strategy and outline the key challenges in adapting it to diverse polymeric materials and loading scenarios.

Hybrid Additive Manufacturing for Site‐Specific Tensile Response in 316L Stainless Steel

Herein, an alternative way of achieving site‐specific mechanical properties is explored—the hybridization of a directed energy deposition technology with a secondary deformation process (hammer peening (HP)) which acts between deposited layers. By applying the peening in a selective manner, microstructure and hence mechanical properties can be locally varied. Microstructural characterization reveals recrystallization in the HP‐induced deformation zone. The columnar grains of as‐built regions with a grain size of ≈26 μm are transformed into a recrystallized zone with equiaxed grains having a size of ≈8 μm. There is also a highly strain‐hardened region below this recrystallized zone where the dislocation density is more than two times higher than in the as‐built condition. Subsequent tensile testing reveals that these microstructural zones corresponded to local enhancement in tensile strength normal to the build direction. The strengthening mechanisms are identified as Hall–Petch and dislocation (Taylor) strengthening, and their relative contributions are studied. The local strength enhancement comes at the expense of ductility in the build direction, which is studied via finite element modeling and attributed to strain localization into non‐strengthened areas. The results from this work show the possibility of achieving site‐specific properties via interlayer processing.

X-ray micro-computed tomography for mechanical behaviour analysis of Automated Fiber Placement (AFP) laminates with integrated gaps and overlaps

Automated Fiber Placement (AFP) is a manufacturing technique widely used for the serial production of aerospace parts. A deep understanding of the effect of lay-up defects is crucial for part and lay-up design. Currently, numerical models for structural simulation lack a precise representation of the internal structure of AFP laminates, which is crucial for understanding the impact of defects on mechanical properties. This paper presents a novel approach based on high-resolution micro-computed tomography (micro-CT) scans from specimens manufactured with AFP, which automatically creates a mesoscale numerical model incorporating as-fabricated defect morphologies. The hexahedral mesh, generated from the segmented plies of the micro-CT volume, accounts for ply thickness and out-of-plane fiber orientation. This approach is verified with mechanical testing and digital image correlation (DIC) under tensile loading. The simulation results align closely with experimental testing and accurately illustrate the influence of fiber waviness in various defect configurations, such as gaps and overlaps. The study shows that lay-up defects can lead to knockdown factors of up to 12% in tensile properties, with each defect creating a distinct pattern in the local strain. This model can serve as a benchmark for further numerical simulations and surrogate models of defect configurations under varying loading conditions.

Influence of Teachers’ Professional Training and Development on Students’ Academic Performance in Public Secondary Schools in Ndhiwa Sub-County Homabay County, Kenya

Purpose: The persistent academic underperformance in public secondary schools in Kenyan rural areas has raised concerns among educators, policymakers, and local communities. The purpose of the study is to evaluate how teacher professional training and development influence academic performance. One of the key factors believed to have contributed to this challenge is the lack of sufficient and effective professional training and development programs for teachers. There is a growing need to examine how teachers' professional training and development influence students' academic outcomes. The problem this study seeks to address is the unclear and under-researched relationship between teachers' professional development and students' academic performance in Ndhiwa Sub-County. Methodology: The study used descriptive research design and 15 public secondary schools, 113 teachers and 522 students were involved in the study as study respondents. The study used document analysis and semi structured questionnaires to collect the quantitative data, which was analyzed through descriptive statistics (frequencies and percentages). Findings: The study reveals that teachers' professional training and development have a significant impact on students' academic performance in public secondary schools in Ndhiwa Sub-County. The findings also indicated that teachers who undergo continuous professional development are better equipped with modern teaching strategies, content knowledge, and student engagement techniques, which in turn positively influence students' academic outcomes. Teachers with higher levels of training and access to ongoing professional development demonstrate improved classroom management, increased use of learner-centered methodologies, and more effective assessment technique. Unique Contribution to Theory, Practice and Policy: From the study findings, the study recommends that schools and educational authorities should develop more structured and regular Continuous Professional Development (CPD) programs that focus on subject-specific training, pedagogical skills, and updated teaching methodologies. This is because the study findings likely indicate that teachers who engage in regular training and development show better performance in student outcomes. The education policy makers should come up with the programs that forge partnerships between secondary schools and local universities or teacher training colleges to provide advanced training opportunities and access to educational research.

Integrated manufacturing of powder metallurgy preparation-thixoforming for Al0.8Co0.5Cr1.5CuFeNi HEA: Excellent formability and enhancement by in-situ generated Al2O3 in liquid phase

Thixoforming displays wild application prospects in manufacturing Cu containing high entropy alloy (HEA) product. In current work, we proposed a novel manufacturing strategy on powder metallurgy preparation-thixoforming for Cu containing HEAs, integrating material preparation, shaping and strengthening objectives. During thixoforming, oxide in-situ generation in liquid phase was utilized to reinforce soft phase, achieving the strengthening of component. Based on this strategy, manufacturing of disc-shaped component for a model Al0.8Co0.5Cr1.5CuFeNi HEA was studied. Compared to 1175 °C thixoforming, room-temperature strength experiences a breakthrough increase at 1200 °C and 1225 °C, accompanied by an increase in yield strength of 323.8 MPa and 314.8 MPa, an increase in ultimate strength of 374.2 MPa and 470.0 MPa, meanwhile, fracture strain improves, which is caused by a considerable amount of in-suit generated Al2O3. Homogeneous and almost defect free microstructure obtained under higher temperature conditions ensures uniformity of mechanical properties for the whole component. As thixoforming temperature increases, preferred orientation of grain fiber shape becomes random, plastic deformation of solid grain (PDS) turns to flow of liquid incorporating solid particles (FLS), sliding between solid particles (SS) during material flow filling, which effectively reduces material damage risk caused by strain localization. In-situ generated Al2O3 in liquid phase helps to hinder crack propagation and blunt crack tip in Cu rich soft phase. Al2O3 only strengthens soft phase, relieving mismatch of strength-plasticity properties between soft and hard phase, accordingly, failure of soft phase is delayed and simultaneous improvement of strength and plasticity is achieved.

Study of Microstructural Evolution and Strain Analysis in SiOx/C Negative Electrodes Using In‐situ X‐ray Tomography and Digital Volume Correlation

Increasing the silicon content in batteries is expected to enhance their capacity. However, its implementation comes with challenges, as silicon exhibits a large volumetric expansion. This is a significant factor contributing to the decreased lifespan of these batteries, one of the critical degradation mechanisms from a mechanical perspective is the delamination of electrode structure. The cyclability of these anodes is noted to be influenced by the interaction between the binder and particles during battery cycling. The heavy local strain experienced by particles in these electrodes often leads to binder failure, resulting in particle detachment, or delamination over multiple cycles. A good understanding of the local evolution of the strain is essential in advancing the mechanical modelling of the degradation mechanism and in realizing the complete potential of silicon‐based electrodes. In this work, in situ global and local strain measurements were performed by combining synchrotron tomography with Digital volume correlation (DVC). The measurements showed that there is significant local strain in these electrodes which can lead to delamination. In addition to this, the spatial variability of the composite electrodes was characterized by estimating the characteristic length to strain, which can be used to replicate the strain field and model the delamination.

Bidirectional Corrective Model-Contrastive Federated Adversarial Training

When dealing with non-IID data, federated learning confronts issues such as client drift and sluggish convergence. Therefore, we propose a Bidirectional Corrective Model-Contrastive Federated Adversarial Training (BCMCFAT) framework. On the client side, we design a category information correction module to correct biases caused by imbalanced local data by incorporating the local client’s data distribution information. Through local adversarial training, more robust local models are obtained. Secondly, we propose a model-based adaptive correction algorithm in the server that leverages a self-attention mechanism to handle each client’s data distribution information and introduces learnable aggregation tokens. Through the self-attention mechanism, model contrast learning is conducted on each client to obtain aggregation weights of corrected client models, thus addressing the issues of accuracy degradation and slow convergence caused by client drift. Our algorithm achieves the best natural accuracy on the CIFAR-10, CIFAR-100, and SVHN datasets and demonstrates excellent adversarial defense performance against FGSM, BIM, and PGD attacks.

Feasibility of manufacturing high-aspect-ratio hollow tubes of SS410 through wire-arc directed energy deposition

This study reports new observations from the fabrication of high-aspect-ratio hollow tubes of SS410 through wire-arc directed energy deposition (wire-arc DED) process. Characterisation work was performed on a single tube as a function of its build height. The maximum ultimate tensile strength (UTS) of 1372 MPa and maximum yield strength (YS) of 980 MPa were achieved in the middle region of the tube. The highest UTS in the middle was attributed to the low delta ferrite content. The reduction of delta ferrite was found to be linked with the repetitive heating and cooling. In contrast, the top and bottom sections exhibit a substantial presence of delta ferrite, indicating that the cyclic effects were not considerable. Nevertheless, the presence of significant ductility in the bottom region of the component indicated the occurrence of tempering effects. This observation is further supported by the lower levels of local strain observed using KAM mapping. Overall, this work proposes a novel fabrication method for producing hollow sections with superior strength and ductile properties.

Assessment of Different Cucurbit Genotypes for Resistance to Zucchini Yellow Mosaic Virus (ZYMV)

Members of the Cucurbitaceae family, which includes species with quite different characteristics, have been used for food, medicine, and ornamental purposes for a long time. However, most plant diseases and pests cause yield and quality losses in cucurbits, and one of the most important of these diseases is zucchini yellow mosaic virus (ZYMV), which one of the most common potyviruses worldwide and causes serious yield losses in cucurbit production worldwide. Zucchini Yellow Mosaic Virus shows symptoms such as yellowing, mottling, curling, deformation, mosaic, shortening and thickening of the internodes, and may also cause loss of yield and quality. As widely known, there is no effective chemical control of viral diseases, and the use of resistant or tolerant varieties is the most effective solution. In this study, 92 watermelon genotypes, 14 zucchinis (pumpkin seeds) and 29 ornamental pumpkins collected from different parts of Türkiye were tested against ZYMV. Symptoms of ZYMV in different watermelon genotypes and pumpkins were observed for 21 days. Genotypes showing systemic infection after inoculation were evaluated on a scale of 0-5. Also, RT-PCR studies were carried out on selecting nine symptomless control plants, seven ZYMV-sensitive genotypes showing 5-scale value, one genotype with 1-scale value considered tolerant, and one genotype belongs to C. lanatus var. citroides. According to the results, it was determined that some watermelon and ornamental pumpkin genotypes could be considered as tolerant. Watermelon, which was having accession number PI560016, was found resistant to Turkish local strain of ZYMV. Although different susceptibility levels were detected between watermelon genotypes, all pumpkin genotypes were discovered to be susceptible to the Turkish local strain of ZYMV.

High strain rate tensile deformation of similar and dissimilar AA6082 and AA7075 friction-stir-welded blanks

Friction-stir-welding process has become an established solid-state technique for joining of dissimilar lightweight materials over the past decade by overcoming fundamental welding challenges such as solidification cracking, phase segregation and surface oxidation. Despite these unique capabilities, the resulting microstructure feature in the weld zone consisting of fine grains with a high dislocation density, challenges further heat treatment and forming processes. Hence, a high solution annealing temperature results in degradation of the adjusted microstructure and in a lower to reduced mechanical properties in case of dissimilar joints of precipitation-hardenable aluminum alloys. Subsequent hot forming therefore involves a great effort and requires further heat treatment steps. Thus, the present study investigates the effect of a recently introduced novel thermo-mechanical forming process on local deformation behavior of similar as well as dissimilar joints processed by friction-stir-welding technique of thin-walled AA6082 and AA7075 blanks. To avoid the complete elimination of the adjusted microstructure, the welding process is performed after a thermo-mechanical process consisting of solution annealing, die cooling and peak aging. Uniaxial tensile tests are then carried out at high strain rates ranging from ε˙ = 40 s-1 to ε˙ = 400 s-1. The results show an increase in yield and ultimate tensile strength as well as in total elongation after failure with increasing strain rates. As the strain rate increases, the flow stress of similar weld of AA7075 is higher than those of AA6082 and the dissimilar weld of AA6082 and AA7075. Local deformation measurements reveal higher strain localization in the welded zone for similar welds, which leads to micro-crack initiation and failure due to strain accumulation. Microstructure analysis shows very fine equiaxed grain structure in the nugget zone and homogenous distribution of precipitates after friction stir welding process, which explain the plastic deformation behavior.

Synthesis of bioinspired gradient MoS2/TiO2 coatings for enhancing tribological performance of titanium alloys

To enhance the tribological performance of titanium alloys under high frictional load, a MoS2/TiO2 composite coating with grain size gradient (GSG) distribution was presented. Inspired by the design principles of dental structures, the coating was fabricated through precise control of step-up voltage during plasma electrolytic oxidation (PEO). The variation in the frequency distribution of MoS2 grain sizes along the coating growth direction, ranging from approximately 43.23 ∼ 48.46 nm and 5.32 ∼ 8.16 nm, is attributed to increased energy supply and a higher degree of subcooling as the PEO voltage was elevated. The GSG coating significantly reduces the average coefficient of friction and abrasion loss by 65.44 % and 30.62 % with loads increasing to 10 N, compared with the MoS2/TiO2 coating. This improvement is attributed to the cooperative deformation of grains with varying sizes within the GSG structure under high frictional loads, which promotes strain delocalization and facilitates the formation of strain transition zones. These mechanisms effectively mitigate strain localization and ultimately achieve superior anti-friction performance. This study is essential for enhancing the broad application of titanium alloys in high-frictional environments.

Strain rate sensitivity of rotating-square auxetic metamaterials

This study provides an in-depth analysis of the mechanical behavior of rotating-square auxetic structures under various strain rates. The structures are fabricated using stereolithography additive manufacturing with a flexible resin. Mechanical tests performed on structures include quasi-static, intermediate, and high strain rate compression tests, supplemented by high-speed optical imaging and two-dimensional digital image correlation analyses. In quasi-static conditions (5 × 10–3 s-1), multiscale measurements reveal the correlation between local and global strains. It is shown that cell hinges play a significant role in structural deformation and load-bearing capacity. In drop tower impact conditions (intermediate strain rate of ca. 200 s-1), the auxetic structures display significant strain rate hardening compared to loading at quasi-static rates. The thin-hinge structures maintain a Poisson's ratio of approximately -0.8, showing higher auxeticity than slow-rate compression tests. High strain rate conditions (ca. 2000s-1) activate additional deformation mechanisms, including a delayed state of equilibrium exemplified by a heterogeneous distribution of lateral strains, possibly due to stress wave interactions and inertial stresses. The study further reveals nonlinear correlations between Poisson's ratio, strain, and strain rate, indicating reduced auxeticity at higher strain rates. These observations are discussed in terms of complex wave interactions and the strain rate hardening characteristics of the base polymer.

Vector competence of Aedes albopictus field populations from Reunion Island exposed to local epidemic dengue viruses

Dengue virus (DENV) is the most prevalent mosquito-borne Flavivirus that affects humans worldwide. Aedes albopictus, which is naturally infected with the bacteria Wolbachia, is considered to be a secondary vector of DENV. However, it was responsible for a recent DENV outbreak of unprecedented magnitude in Reunion Island, a French island in the South West Indian Ocean. Moreover, the distribution of the cases during this epidemic showed a spatially heterogeneous pattern across the island, leading to questions about the differential vector competence of mosquito populations from different geographic areas. The aim of this study was to gain a better understanding of the vector competence of the Ae. albopictus populations from Reunion Island for local DENV epidemic strains, while considering their infection by Wolbachia. Experimental infections were conducted using ten populations of Ae. albopictus sampled across Reunion Island and exposed to three DENV strains: one strain of DENV serotype 1 (DENV-1) and two strains of DENV serotype 2 (DENV-2). We analyzed three vector competence parameters including infection rate, dissemination efficiency and transmission efficiency, at different days post-exposition (dpe). We also assessed whether there was a correlation between the density of Wolbachia and viral load/vector competence parameters. Our results show that the Ae. albopictus populations tested were not able to transmit the two DENV-2 strains, while transmission efficiencies up to 40.79% were observed for the DENV-1 strain, probably due to difference in viral titres. Statistical analyses showed that the parameters mosquito population, generation, dpe and area of sampling significantly affect the transmission efficiencies of DENV-1. Although the density of Wolbachia varied according to mosquito population, no significant correlation was found between Wolbachia density and either viral load or vector competence parameters for DENV-1. Our results highlight the importance of using natural mosquito populations for a better understanding of transmission patterns of dengue.