Deletion Of Element Research Articles

Almost Difference Set Pairs and Ideal Three-Level Correlation Binary Sequence Pairs

Almost difference set pairs are used in cryptography and coding theory, and a majority of the acknowledged almost difference set pairs are constructed by Chinese remainder theorem, cyclotomy or interleaving. In this paper, through the addition or deletion of elements from difference sets and difference set pairs, we ourselves construct almost difference set pairs and sequences thereof. Further, we obtain the ideal three-level correlation binary sequence pairs with high energy efficiency by some renown difference sets or difference set pairs, e.g. Palay-Hardmard difference sets.

Structural and catalytic effects of surface loop-helix transplantation within haloalkane dehalogenase family

Engineering enzyme catalytic properties is important for basic research as well as for biotechnological applications. We have previously shown that the reshaping of enzyme access tunnels via the deletion of a short surface loop element may yield a haloalkane dehalogenase variant with markedly modified substrate specificity and enantioselectivity. Here, we conversely probed the effects of surface loop-helix transplantation from one enzyme to another within the enzyme family of haloalkane dehalogenases. Precisely, we transplanted a nine-residue long extension of L9 loop and α4 helix from DbjA into the corresponding site of DbeA. Biophysical characterization showed that this fragment transplantation did not affect the overall protein fold or oligomeric state, but lowered protein stability (ΔTm = −5 to 6 °C). Interestingly, the crystal structure of DbeA mutant revealed the unique structural features of enzyme access tunnels, which are known determinants of catalytic properties for this enzyme family. Biochemical data confirmed that insertion increased activity of DbeA with various halogenated substrates and altered its enantioselectivity with several linear β-bromoalkanes. Our findings support a protein engineering strategy employing surface loop-helix transplantation for construction of novel protein catalysts with modified catalytic properties.

Angiogenesis-Centered Molecular Cross-Talk in Amyotrophic Lateral Sclerosis Survival: Mechanistic Insights.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that is characterized with progressive muscle atrophy. We have attempted to establish the link between angiogenesis and cellular survival in the pathogenesis of ALS by compiling evidence described in various scientific reports. The phenotypes of human ALS have earlier been captured in the mutant SOD1 mice as well as by targeted deletion of the hypoxia response element (HRE) from the promoter of the mouse gene for vascular endothelial growth factor (VEGF). Indirect evidence shows that angiogenesis can help prevent oxidative stress, and hence, enhance cell survival. VEGF and angiogenin chiefly regulate the process of angiogenesis. Transactive response DNA-binding protein 43 (TDP-43) is usually found inside the nucleus, but in large number of cases of ALS, it accumulates in the cytoplasm (TDP-43 proteinopathy). Interestingly, TDP-43 proteinopathy is found to be aggravated in the presence of the OPTN mutation, which is the genetic factor that is responsible for such accumulation. Interaction of TDP-43 with progranulin can further affect the angiogenesis in ALS patients by regulating activity of VEGF receptors, but conclusive evidence is needed to establish its role in pathogenesis of ALS. Certain mutations in UBQLN2 and UBQLN4 indicate that ubiquitination has a role in ALS pathobiology, but its link to angiogenesis has not been adequately studied. Recent studies have shown that several mutations in RNA-binding proteins (RBPs) can also cause ALS. Conclusively, in this review, we have attempted to argue the role of angiogenesis in enhanced ALS survival rate is probably regulated with the activation of NF-κβ. Additionally, interaction between OPTN and TDP-43 can also impact the transcription of various angiogenic molecules. Whether targeting angiogenic substances or TDP-43 can provide clues about extending ALS survival rate, in combination with current treatments, can only be evaluated after additional studies.

Finite Element Analysis to Investigate the Effect of Loading Modes on the CTOA of DWTT Specimens

To replace the traditional Charpy-test-based fracture arrest methodology, the crack tip opening angle (CTOA) has been proposed as a fracture propagation parameter for prediction of fast ductile fracture propagation and arrest of axial cracks in pipelines. Transferability of CTOA from the DWTT specimens determined according to ASTM E3039 to other specimens and especially pipes is critical to the applications of CTOA. As part of the research effort to investigate the transferability of crack tip opening angle (CTOA) from the drop weight tear test (DWTT) specimens to pipelines, this work focuses on the effect of loading modes (bending vs. tension) of DWTT specimens on CTOA based on finite element analysis. The damage-mechanics model (Modified Mohr-Coulomb Model) and element deletion technique to simulate crack initiation and propagation is found to be accurate and agrees well with test data. This model accounted for variations in stress triaxiality and Lode angle at the crack front. For the DWTT model under bending, the surface CTOA is considerably larger than the interior CTOA consistent with the experimental observations. However, for the DWTT specimen under tension, the CTOA on surface and interior are almost the same. The interior CTOA is found to be very similar in all cases. The CTOA distribution as a function of distance behind the crack tip is found to be very consistent up to one half-thickness behind the crack tip, where CTOA starts to increase gradually. For both the bending and tension DWTT simulations, steady-state crack growth was achieved at a reasonably low crack extension. These results support the transferability of CTOA from standard DWTT tests according to ASTM E3039 to other loading cases.

Development of a New Self-flaring Rivet Geometry Using Finite Element Method and Design of Experiments

The paper presents a new joining process for mixed joints of metallic and non-metallic materials. The process bases on a self-flaring rivet, which lances the joining partners and, due to its geometry, produces an interlock. In contrast to conventional self-piercing processes such as self-pierce riveting with semi-tubular rivets (SPR), the new process does not require a special shaped die as counter tool. The development of the rivet geometry is carried out with the aid of FEM analyses in SFTC Deform-3D. Design of experiments (DoE) is used to find a suitable rivet geometry that is stable enough to lance high-strength steel. However, the rivet element must be flaring to produce an interlock. The challenges and solution approaches associated with the modelling of material damage and separation in the three-dimensional calculation models of the riveting process are presented. The consideration of macromechanical and geometrical criteria for element deletion is important in order to obtain robust models with useful results. The validation of the model is done by comparing the simulation results with experimental data.

Synta-Pragmatics of The Conjunctions in Kurdish Language

The title of this research is (The Syntax-Pragmatics of the Conjunctions in Kurdish Language). The conjunctions have a great role in language by connecting between words, phrases and sentences. They also have a significant role in deletion of reduction extra elements. These are some examples of them in Kurdish; ‘belam, û, belku, ne…ne, keçî, and so on’. They have a great role in clarifying the aims of the speaker and its ideas. The study consists of two main parts and the bibliography. In the first part of the research, the syntactical role of the conjunctions is shown. Furthermore, the places of the conjunctions in compound sentences are explained. According to the Kurdish language grammatical rules, there is not a specified gap for the conjunctions, and their places are changeable within compound sentences. Besides that, compound sentences also categorized according their dual or multi branches. Each part of the compound sentences have its importance, and their level are not same. The second part of the research deals with the pragmatics role of the conjunction. The focus is on the new meaning that are made in collocation with other parts of the sentence to send the message of the speaker. This is because their meaning is very related with the context. Eventually, the conclusion is drawn.

Determination of optimum numerical parameters in a 3D model of finish turning operation applied to Inconel 718

Finish turning operation consists in a three-dimensional cutting process carried out to accurate size removing a very thin chip section from the work-piece. In this paper, we propose a numerical model of finish turning operation applied to Inconel® 718. The work is focused on the determination of optimum numerical parameters (mesh size and deletion element criterion) for the modeling of chip removing process: 1/ at least 10 elements in the feed direction are needed to predict the cutting forces with accuracy; 2/ the calibration of shear element deletion is a fundamental key: its value affects drastically the temperature distribution in the machined piece. A numerical study on global variables (cutting forces and chip morphology) and local variables (strain, strain rates and temperature) in the chip is presented and discussed. Finally a comparison with experimental measurements in term of forces shows a good accuracy with numerical predictions (the average relative error between numerical and experimental forces is around 2% considering a cutting speed Vc = 300 m/min).

Interrogating the Grainyhead-like 2 (Grhl2) genomic locus identifies an enhancer element that regulates palatogenesis in mouse

The highly-conserved Grainyhead-like (Grhl) transcription factors are critical regulators of embryogenesis that regulate cellular survival, proliferation, migration and epithelial integrity, especially during the formation of the craniofacial skeleton. Family member Grhl2 is expressed throughout epithelial tissues during development, and loss of Grhl2 function leads to significant defects in neurulation, abdominal wall closure, formation of the face and fusion of the maxilla/palate. Whereas numerous downstream target genes of Grhl2 have been identified, very little is known about how this crucial developmental transcription factor itself is regulated. Here, using in silico and in utero expression analyses and functional deletion in mice, we have identified a novel 2.4 ​kb enhancer element (mm1286) that drives reporter gene expression in a pattern that strongly recapitulates endogenous Grhl2 in the craniofacial primordia, modulates Grhl2 expression in these tissues, and augments Grhl2-mediated closure of the secondary palate. Deletion of this genomic element, in the context of inactivation of one allele of Grhl2 (through generation of double heterozygous Grhl2+/−;mm1286+/− mice), results in a significant predisposition to palatal clefting at birth. Moreover, we found that a highly conserved 325 bp region of mm1286 is both necessary and sufficient for mediating the craniofacial-specific enhancer activity of this region, and that an extremely well-conserved 12-bp sequence within this element (CTGTCAAACAGGT) substantially determines full enhancer function. Together, these data provide valuable new insights into the upstream genomic regulatory landscape responsible for transcriptional control of Grhl2 during palatal closure.

Thermomechanical coupling investigation in Ti-6Al-4V orthogonal cutting: Experimental and numerical confrontation

The constant industrial need of detail data on the chip formation meets with the lack of a physical understanding of the thermo-mechanical couplings during hard metal cutting. In the present paper, numerical and experimental investigations at micro scale (about 0.5 × 0.5 mm2 area), is performed in order to highlight the mechanisms responsible for the poor Ti-6Al-4V machinability. In a first step, strain, strain-rates, temperatures, dissipated powers along with displacements, velocity and crack propagation are obtained at each pixel by means of VISIR apparatus. Experimental observations have highlighted the dependency of the physical phenomena to both cutting speed and rake angle and provide valuable evidences on the different nature of the coupling phenomenon. Secondly, a 3D FE orthogonal cutting model is then developed to bring a multi-scale comprehension of Ti-6Al-4V chip genesis and to predict the kinematics and thermal quantities. The numerical and experimental confrontation revealed the robustness of the developed FE model as well as its limits. Hence, the element deletion method and the friction model are identified as the main weak spots of the proposed FE model. Finally, a particular attention is paid to the chip formation steps and their impact on the final part.

Parallel evolution of ancient, pleiotropic enhancers underlies butterfly wing pattern mimicry

Color pattern mimicry in Heliconius butterflies is a classic case study of complex trait adaptation via selection on a few large effect genes. Association studies have linked color pattern variation to a handful of noncoding regions, yet the presumptive cis-regulatory elements (CREs) that control color patterning remain unknown. Here we combine chromatin assays, DNA sequence associations, and genome editing to functionally characterize 5 cis-regulatory elements of the color pattern gene optix We were surprised to find that the cis-regulatory architecture of optix is characterized by pleiotropy and regulatory fragility, where deletion of individual cis-regulatory elements has broad effects on both color pattern and wing vein development. Remarkably, we found orthologous cis-regulatory elements associate with wing pattern convergence of distantly related comimics, suggesting that parallel coevolution of ancestral elements facilitated pattern mimicry. Our results support a model of color pattern evolution in Heliconius where changes to ancient, multifunctional cis-regulatory elements underlie adaptive radiation.

Damage simulation of fiber reinforced composites using mean‐field homogenization methods

AbstractOur work presents a two‐scale mean‐field homogenization framework for constitutive multiscale (meso‐macro) modeling of fiber reinforced composites (FRC) including damage. The FRC is decomposed into three distinct linear thermo‐chemo‐elastic material phases. The three phases are unidirectional fibers surrounded by an interface, which is surrounded by a matrix material. Different mean‐field homogenization methods can be used to determine the effective properties. For the damage a distinction is made between four different damage modes namely matrix damage, fiber damage, interface damage and a simultaneous damage of the matrix and the fiber called matrix‐fiber damage. An element deletion algorithm is used to simulate a crack propagation. A representative example demonstrates the different types of damage and a resulting crack propagation in an FRC.

ZmDREB1A Regulates RAFFINOSE SYNTHASE Controlling Raffinose Accumulation and Plant Chilling Stress Tolerance in Maize.

Raffinose accumulation is positively correlated with plant chilling stress tolerance; however, the understanding of the function and regulation of raffinose metabolism under chilling stress remains in its infancy. RAFFINOSE SYNTHASE (RAFS) is the key enzyme for raffinose biosynthesis. In this study, we report that two independent maize (Zea mays) zmrafs mutant lines, in which raffinose was completely abolished, were more sensitive to chilling stress and their net photosynthetic product (total soluble sugars and starch) accumulation was significantly decreased compared with controls after chilling stress. A similar characterization of the maize dehydration responsive element (DRE)-binding protein 1A mutant (zmdreb1a) showed that ZmRAFS expression and raffinose content were significantly decreased compared with its control under chilling stress. Overexpression of maize ZmDREB1A in maize leaf protoplasts increased ZmDREB1A amounts, which consequently upregulated the expression of maize ZmRAFS and the Renilla LUCIFERASE (Rluc), which was controlled by the ZmRAFS promoter. Deletion of the single dehydration-responsive element (DRE) in the ZmRAFS promoter abolished ZmDREB1A's influence on Rluc expression, while addition of three copies of the DRE in the ZmRAFS promoter dramatically increased Rluc expression when ZmDREB1A was simultaneously overexpressed. Electrophoretic mobility shift assays and chromatin immunoprecipitation-quantitative PCR demonstrated that ZmDREB1A directly binds to the DRE motif in the promoter of ZmRAFS both in vitro and in vivo. These data demonstrate that ZmRAFS, which was directly regulated by ZmDREB1A, enhances both raffinose biosynthesis and plant chilling stress tolerance.

Holding on to let go: Identity work in discontinuous and involuntary career transitions

This study examined the identity work processes of severely disabled soldiers who faced discontinuous and involuntary career transitions. As these individuals engaged in rehabilitation and vocational training at a military-affiliated facility, their identity transitions were not marked by deletions of past identity elements or reference groups. Instead, their transitions involved collectively and contextually edited imaginations of the future that allowed for continuity of their foundational self-narratives. The findings extend past research by identifying why the forging of continuity is generative during certain identity transitions. The findings also show that when similar others contribute to the script of one’s identity narrative within a familiar liminal context, maintaining a semblance of the status quo is construed as change.

Compression failure characterization of cancellous bone combining experimental testing, digital image correlation and finite element modeling

Cancellous bone yield strain has been reported in the literature to be relatively constant and independent from microstructure and apparent density, while fracture strain shows higher scattering. The objective of this work is to assess this hypothesis, characterizing the compression fracture in cancellous bone from a numerical approach and relating it to morphological parameters. Quasi-static compression fractures of cancellous bone samples are modeled using high-resolution image-based finite elements, correlating the numerical models and experimental results. The yield strain and the strain at fracture are inferred from the micro-CT-based finite element models by inverse analysis. The validation of the fracture models is carried out through digital image correlation (DIC). To develop this work, cancellous bone parallelepiped-shaped specimens were prepared and micro-CT scanned at 22 μm spatial resolution. A morphometric analysis was carried out for each specimen in order to characterize its microstructure. Quasi-static compression tests were conducted, recording the force-displacement response and a sequence of images during testing for the application of the DIC technique. This was applied without the need of a speckle pattern benefiting from the irregular microstructure of cancellous bone. The finite element models are also used to simulate the local fracture of trabeculae at the micro level using a combination of continuum damage mechanics and the element deletion technique. Equivalent strain, computed both from DIC and micro-FE, was the best predictor of the compression fracture pattern. The procedure followed in this work permits the estimation of failure parameters that are difficult to measure experimentally, which can be used in numerical models.

Numerical study of reinforced concrete slabs under extreme loading conditions: Impact and fire

In the present paper, the influence of thermally induced damage of reinforced concrete (RC) slabs on their impact properties are numerically investigated. The RC slabs are first pre-damaged through fire load and then loaded by the impact of hammer. Transient 3D finite element (FE) thermo-mechanical analysis is performed. Subsequently, impact simulation is conducted based on the explicit multi-body dynamic analysis and contact algorithm with adaptive element deletion technique. As a constitutive law for concrete rate and temperature, dependent microplane model is employed. The co-rotational Cauchy stress tensor and Green-Lagrange strain tensor are used in the framework of total Lagrange FE formulation. The numerical results are discussed and compared with those obtained experimentally. It is shown that pre-damage of RC slab through fire reduces the impact resistance of the slabs, and that the simulation is able to realistically replicate the experimental tests.

Thermal response analysis of reinforced concrete box girder during hot-mixed asphalt mixture paving

Hot-mixed asphalt (HMA) concrete has been extensively used in the concrete box-girder bridge deck pavement due to its excellent performance and driving comfort. Nevertheless, during HMA concrete construction, the high paving temperature may disturb the thermal field of the bridge, thereby causing the significant thermal response throughout the box girder. Therefore, this research aims to investigate the temperature behavior and thermal stress of a reinforced concrete box girder segment during HMA concrete paving. The transient thermal field theory and element deletion method were first adopted to establish a three-dimensional finite element model of a reinforced concrete box girder segment and simulate the dynamic paving process, respectively. Subsequently, the bridge monitoring data was used to validate the thermal field model and then the temperature distribution analysis was conducted. Finally, the thermal stress in the bridge was studied in cross-sectional area. Results demonstrate that the vertical temperature of the concrete box-girder during the paving process is declined with the increasing vertical distance to SFRC leveling layer, and its highest value occurs at 36min after starting to paving. Furthermore, in the vertical direction, the west web-plate is subjected to compressive stress at locations of two ends and tensile stress at locations of the middle. Meanwhile, the thermal stresses undergo a decline trend after short-term growth both in the box and flange slab in the transversal direction.

Cutting Edge: Tcf1 Instructs T Follicular Helper Cell Differentiation by Repressing Blimp1 in Response to Acute Viral Infection.

Differentiation of T follicular helper (TFH) cells is regulated by a complex transcriptional network, with mutually antagonistic Bcl6-Blimp1 as a core regulatory axis. It is well established that Tcf1 acts upstream of Bcl6 for its optimal induction to program TFH cell differentiation. In this study, we show that whereas genetic ablation of Tcf1 in mice greatly diminished TFH cells in response to viral infection, compound deletion of Blimp1 with Tcf1 restored TFH cell frequency, numbers, and generation of germinal center B cells. Aberrant upregulation of T-bet and Id2 in Tcf1-deficient TFH cells was also largely rectified by ablating Blimp1. Tcf1 chromatin immunoprecipitation sequencing in TFH cells identified two strong Tcf1 binding sites in the Blimp1 gene at a 24-kb upstream and an intron-3 element. Deletion of the intron-3 element, but not the 24-kb upstream element, compromised production of TFH cells. Our data demonstrate that Tcf1-mediated Blimp1 repression is functionally critical for safeguarding TFH cell differentiation.

Thermal damage analysis of aircraft composite laminate suffered from lightning swept stroke and arc propagation

Lightning strike is a complicated process involving multi-field coupling. In order to investigate the thermal damage mechanism of carbon fiber reinforced composites subject to lightning swept stroke, a complete numerical method is presented. Numerical model of lightning discharge is established based on Magneto Hydro Dynamics (MHD) and calculated by FLUENT secondary development technology. Considering aerodynamic flow effect, channel formation and evolution process during lightning discharge is analyzed for lightning current waveform A. Thermal-electric Coupling model is presented according to Radial Basis Function (RBF) interpolation theory, which is implemented by compiling program to make lightning current and heat energy inject into composite laminate. Consequently, damage mechanism of composite laminate under lightning swept stroke is studied based on the coupled numerical model and element deletion method. Ablation damage morphology of composite laminate is analyzed to understand plasma expansion and reattachment in arc root. The results show that aerodynamic flow makes the lightning channel move fast and composite laminate is deteriorated due to thermal damage.

Engineering Escherichia coli for enhanced sensitivity to the autoinducer-2 quorum sensing signal.

The autoinducer-2 (AI-2) quorum sensing system is involved in a range of population-based bacterial behaviors and has been engineered for cell-cell communication in synthetic biology systems. Investigation into the cellular mechanisms of AI-2 processing has determined that overexpression of uptake genes increases AI-2 uptake rate, and genomic deletions of degradation genes lowers the AI-2 level required for activation of reporter genes. Here, we combine these two strategies to engineer an Escherichia coli strain with enhanced ability to detect and respond to AI-2. In an E. coli strain that does not produce AI-2, we monitored AI-2 uptake and reporter protein expression in a strain that overproduced the AI-2 uptake or phosphorylation units LsrACDB or LsrK, a strain with the deletion of AI-2 degradation units LsrF and LsrG, and an "enhanced" strain with both overproduction of AI-2 uptake and deletion of AI-2 degradation elements. By adding up to 40 μM AI-2 to growing cell cultures, we determine that this "enhanced" AI-2 sensitive strain both uptakes AI-2 more rapidly and responds with increased reporter protein expression than the others. This work expands the toolbox for manipulating AI-2 quorum sensing processes both in native environments and for synthetic biology applications.

Nested retrotransposition in the East Asian mouse genome causes the classical nonagouti mutation

Black coat color (nonagouti) is a widespread classical mutation in laboratory mouse strains. The intronic insertion of endogenous retrovirus VL30 in the nonagouti (a) allele of agouti gene was previously reported as the cause of the nonagouti phenotype. Here, we report agouti mouse strains from East Asia that carry the VL30 insertion, indicating that VL30 alone does not cause the nonagouti phenotype. We find that a rare type of endogenous retrovirus, β4, was integrated into the VL30 region at the a allele through nested retrotransposition, causing abnormal splicing. Targeted complete deletion of the β4 element restores agouti gene expression and agouti coat color, whereas deletion of β4 except for a single long terminal repeat results in black-and-tan coat color. Phylogenetic analyses show that the a allele and the β4 retrovirus originated from an East Asian mouse lineage most likely related to Japanese fancy mice. These findings reveal the causal mechanism and historic origin of the classical nonagouti mutation.