Lateral Elements Research Articles

Study of Dimension Variation Effect on a Batter Piled Wharf Structure with Seismic Isolation Systems

In a conventional wharf design, batter piles are incorporated in the design as a primary lateral resistance element, however in recent years it is mostly discouraged to use batter piles in the design of wharf structure, especially in higher seismic zone. The use of seismic isolation in the design of wharf structure has been introduced since 2005 in UFC 4-152-01 code as an alternative design for wharf structure, from several studies it is shown that the usage of seismic isolation systems in wharf design has offered many benefits either in new design or structure retrofitting design. The objective of this research is to study the application of seismic isolation system on wharf structure with batter piles, with study case of the wharf design on Kendari, Sulawesi Tenggara, Indonesia. This objective will be achieved by comparing the length per width (L/W) ratio of wharf structure model to evaluate base reaction, natural period and deflection of structure, from these results, a clearer understanding about the advantages of seismic isolation system in wharf structure, so it will be encouraging the application of seismic isolation systems.

Three-Dimensional Measurement of the Lateral Lip Element Sacrificed in Primary Repair of a Unilateral Cleft Lip

In most children with a unilateral cleft lip (UCL), because lateral lip tissue on the cleft side is congenitally short, the lateral lip element should be appropriately excised during primary cheiloplasty so that symmetric nasolabial features are obtained after surgery. The purpose of this study was to measure how much of the lateral lip element is removed during primary cheiloplasty and compare the amount of sacrifice between different incision designs. Preoperative 3-dimensional images of 50 infants with UCL were randomly selected. The incision designs of 3 representative techniques (Millard, Onizuka, and Fisher) were drawn on the images that were obtained before the primary repair. The lateral lip tissue excised by each technique was estimated as a percentage of the surface area of the sacrificed lateral lip to the entire lateral lip of the cleft side. In the case of incomplete UCL, the median values (range) were 3.2% (1.1%-5.9%), 11.6% (8.3%-20.1%), and 27.2% (15.1%-42.3%) for the Millard, Onizuka, and Fisher repairs, respectively. In cases of complete UCL, no sacrifice was needed for the Millard repair, whereas the median values (range) were 10.6% (5.2%-28.9%) and 22.5% (11.5%-48.6%) for the Onizuka and Fisher repairs, respectively. In Millard repair, the median values (range) of the lateral lip element that was resected before skin closure according to the "cut-as-you-go" policy were 5.8% (2.2%-11.8%) in cases with an incomplete UCL and 4.9% (2.7%-9.1%) in cases with a complete UCL. Our study demonstrated that sacrifice of the lateral lip element was minimal in the Millard repair, whereas it could exceed 20% in the Fisher repair. However, additional sacrifice of the advancement flap was needed in the Millard-type repair. The ratio of the lateral lip sacrifice varied between patients. Although UCL repair techniques should not be evaluated with the sacrifice ratio, excessive sacrifice of the lateral lip tissue can complicate the secondary lip correction. We recommend that surgeons estimate preoperatively how much lateral lip element will be sacrificed with each incision design using a 3-dimensional image for each child with a UCL.

Nasal Alar Surface Area Differences After Unilateral Cleft Lip Repair: Long-Term Effects of the Perialar Incision.

The Millard rotation-advancement cleft lip repair is the most commonly performed cleft lip repair. An extended perialar incision allows for further advancement of the lateral lip element and improved positioning of the alar base. There is a lack of data evaluating differences in nasal alar growth when the perialar incision is utilized. This study compares the long-term effects of a perialar incision on the alar surface area of unilateral cleft lip patients who underwent a Millard cleft lip repair. Thirty-seven patients with a diagnosis of unilateral cleft lip treated with a Millard primary lip repair were studied. A perialar incision was utilized in 16 patients while 21 patients underwent a standard Millard repair. 3dMD facial images were taken at least 10 years after the initial lip repair. Using the patient's non-cleft side as an internal control, the Alar Ratio (AR) was calculated, defined as the cleft alar surface area divided by the non-cleft alar surface area. The AR was significantly greater in the standard Millard repair group compared to the perialar incision group, 0.74 and 0.64 respectively (P = .02). The incomplete cleft population demonstrated a more profound difference between the treatment groups (0.82 and 0.62, respectively). This study reveals an association between a perialar incision and decreased alar surface area. Long-term follow up results suggest a perialar scar restricts alar growth leading to significant asymmetry between the cleft and non-cleft sides. Therefore, surgical technique must be carefully considered prior to utilizing a perialar incision during unilateral cleft lip repair.

Crio-fixation of Pachytene Cells

AbstractGenetic variability in organisms with sexual reproduction is produced by a complex mechanism of cell division of the germ line cells known as meiosis. During meiosis, homologous chromosomes pair and exchange genetic material (meiotic recombination), process that is essential to complete the meiotic division and to produce variability. Homologous chromosome pairing is mediated by the synaptonemal complex (SC). The SC is a proteinaceous structure composed of two lateral elements (LEs) and a central region (CR). Any defect in SC structure impairs meiotic recombination leading to blockage of the cell division process and infertility1. The SC has been observed since the introduction of the electron microscope (EM) in the biological field and it has been reported to be present in almost all the organisms with sexual reproduction, conserving a very similar structure and organisation along the different species2,3. The classic approach to study the SC structure is to chemically fixate the sexual tissues (gonads), dehydrate and embedded them in plastic resins that provide a support for sample sectioning and observation under the EM. However, chemical fixation followed by dehydration is well known to produce artefacts in the structure of many biological samples. Recently, we have combined fluorescence activated cell sorting of cells with SCs with high-pressure freezing and freeze- substitution and have found that the structure of the CR looks different from that observed in chemically fixated samples. These data have prompted us to analyse the organization of the CR components under cryo-processing.

Modeling Hysteretic Behavior of Lateral Load-Resisting Elements in Traditional Chinese Timber Structures

AbstractDou-gong connections and mortise-tenon jointed traditional timber frames are widely used in traditional Chinese timber structures to resist lateral loads. Such elements exhibit strong nonli...

Engineered Lateral Roughness Element Implementation and Working Fluid Alteration to Intensify Hydrodynamic Cavitating Flows on a Chip for Energy Harvesting.

Hydrodynamic cavitation is considered an effective tool to be used in different applications, such as surface cleaning, ones in the food industry, energy harvesting, water treatment, biomedical applications, and heat transfer enhancement. Thus, both characterization and intensification of cavitation phenomenon are of great importance. This study involves design and optimization of cavitation on chip devices by utilizing wall roughness elements and working fluid alteration. Seven different microfluidic devices were fabricated and tested. In order to harvest more energy from cavitating flows, different roughness elements were used to decrease the inlet pressure (input to the system), at which cavitation inception occurs. The implemented wall roughness elements were engineered structures in the shape of equilateral triangles embedded in the design of the microfluidic devices. The cavitation phenomena were also studied using ethanol as the working fluid, so that the fluid behavior differences in the tested cavitation on chip devices were explained and compared. The employment of the wall roughness elements was an effective approach to optimize the performances of the devices. The experimental results exhibited entirely different flow patterns for ethanol compared to water, which suggests the dominant effect of the surface tension on hydrodynamic cavitation in microfluidic channels.

Static connectivity of stacked deep-water channel elements constrained by high-resolution digital outcrop models

High-resolution digital outcrop models of stacked deep-water channel elements are constructed from the Laguna Figueroa section of the well-exposed Upper Cretaceous Tres Pasos Formation in Chilean Patagonia. The models are based on greater than 1600 m (>5250 ft) of centimeter-scale measured sections, greater than 100 paleoflow measurements, and thousands of differential global positioning system points (10-cm [4-in.] accuracy) from an outcrop belt that is approximately 2.5 km (∼1.5 mi) long and 130 m (425 ft) thick. The models elucidate the effects bed-to-geobody–scale architecture has on static sandstone connectivity among a series of stacked deep-water channel elements and how that connectivity is altered by grid cell size. Static connectivity analyses show that channel element base drapes can strongly influence sandstone connectivity and that smaller channel element widths are more likely to produce disconnected sandstone geobodies. Net-to-gross (NTG) is not directly correlated with connectivity because of the presence of thin channel element base drapes, which do not significantly contribute to NTG. Upscaling the models consistently increases channel element contact (up to 10%) but decreases sandstone connectivity (up to 2%–3%). Channel element stacking patterns strongly impact connectivity. For example, connectivity is reduced in cases of high lateral channel element offsets. Increasing drape coverage markedly decreases connectivity. Evaluating connectivity in a vertical, along-system profile is critical to understanding flow units and reservoir piping. Ultimately, this work constrains uncertainty related to the impact of subseismic-scale stratigraphic architecture on reservoir connectivity by providing concrete knowledge that can be used to guide the model building process.

The Impact of Acoustic Clutter on Large Array Abdominal Imaging.

Abdominal imaging suffers from a particularly difficult acoustic environment-targets are located deep and overlying tissue layers with varying properties generate acoustic clutter. Increasing array size can overcome the penetration and lateral resolution problems in ideal conditions, but how the impact of clutter scales with increasing array extent is unknown and may limit the benefits in vivo. Previous ex vivo experimental work showed the promise of large arrays but was technically limited to a length of 6.4 cm and to only partial sampling of the array elements. We present an extension of those studies using the Fullwave simulation tool to create a 10 cm ×2 cm matrix array with full lateral element sampling. We used a numerical model of the abdomen based on the maps of tissue acoustical properties and found that propagation through the modeled abdominal layers generated on average 25.4 ns of aberration and 0.74 cm of reverberation clutter across the array extent. Growing the full aperture from 2 to 10 cm improved contrast by 8.6 dB and contrast-to-noise ratio by 22.9% in addition to significantly improving target resolution. Alternative array strategies that may be useful for implementation-mismatched aperture sizes or a swept synthetic aperture-also produced improved quality with growing aperture size. These results motivate the development of larger diagnostic imaging arrays for the purpose of high-resolution imaging in challenging environments.

Quantitative basis of meiotic chromosome synapsis analyzed by electron tomography

The synaptonemal complex is a multiprotein complex, which mediates the synapsis and recombination between homologous chromosomes during meiosis. The complex is comprised of two lateral elements and a central element connected by perpendicular transverse filaments (TFs). A 3D model based on actual morphological data of the SC is missing. Here, we applied electron tomography (ET) and manual feature extraction to generate a quantitative 3D model of the murine SC. We quantified the length (90 nm) and width (2 nm) of the TFs. Interestingly, the 80 TFs/µm are distributed asymmetrically in the central region of the SC challenging available models of SC organization. Furthermore, our detailed 3D topological analysis does not support a bilayered organization of the central region as proposed earlier. Overall, our quantitative analysis is relevant to understand the functions and dynamics of the SC and provides the basis for analyzing multiprotein complexes in their morphological context using ET.

Molecular architecture of the SYCP3 fibre and its interaction with DNA.

The synaptonemal complex (SC) keeps homologous chromosomes in close alignment during meiotic recombination. A hallmark of the SC is the presence of its constituent protein SYCP3 on the chromosome axis. During SC assembly, SYCP3 is deposited on both axes of the homologue pair, forming axial elements that fuse into the lateral element (LE) in the tripartite structure of the mature SC. We have used cryo-electron tomography and atomic force microscopy to study the mechanism of assembly and DNA binding of the SYCP3 fibre. We find that the three-dimensional architecture of the fibre is built on a highly irregular arrangement of SYCP3 molecules displaying very limited local geometry. Interaction between SYCP3 molecules is driven by the intrinsically disordered tails of the protein, with no contact between the helical cores, resulting in a flexible fibre assembly. We demonstrate that the SYCP3 fibre can engage in extensive interactions with DNA, indicative of an efficient mechanism for incorporation of DNA within the fibre. Our findings suggest that SYCP3 deposition on the chromosome axis might take place by polymerization into a fibre that is fastened to the chromosome surface via DNA binding.

Molecular organization of mammalian meiotic chromosome axis revealed by expansion STORM microscopy

During prophase I of meiosis, chromosomes become organized as loop arrays around the proteinaceous chromosome axis. As homologous chromosomes physically pair and recombine, the chromosome axis is integrated into the tripartite synaptonemal complex (SC) as this structure's lateral elements (LEs). While the components of the mammalian chromosome axis/LE-including meiosis-specific cohesin complexes, the axial element proteins SYCP3 and SYCP2, and the HORMA domain proteins HORMAD1 and HORMAD2-are known, the molecular organization of these components within the axis is poorly understood. Here, using expansion microscopy coupled with 2-color stochastic optical reconstruction microscopy (STORM) imaging (ExSTORM), we address these issues in mouse spermatocytes at a resolution of 10 to 20 nm. Our data show that SYCP3 and the SYCP2 C terminus, which are known to form filaments in vitro, form a compact core around which cohesin complexes, HORMADs, and the N terminus of SYCP2 are arrayed. Overall, our study provides a detailed structural view of the meiotic chromosome axis, a key organizational and regulatory component of meiotic chromosomes.

Ultrastructure and Dynamics of Synaptonemal Complex Components During Meiotic Pairing and Synapsis of Standard (A) and Accessory (B) Rye Chromosomes.

During prophase I a meiosis-specific proteinaceous tripartite structure, the synaptonemal complex (SC), forms a scaffold to connect homologous chromosomes along their lengths. This process, called synapsis, is required in most organisms to promote recombination between homologs facilitating genetic variability and correct chromosome segregations during anaphase I. Recent studies in various organisms ranging from yeast to mammals identified several proteins involved in SC formation. However, the process of SC disassembly remains largely enigmatic. In this study we determined the structural changes during SC formation and disassembly in rye meiocytes containing accessory (B) chromosomes. The use of electron and super-resolution microscopy (3D-SIM) combined with immunohistochemistry and FISH allowed us to monitor the structural changes during prophase I. Visualization of the proteins ASY1, ZYP1, NSE4A, and HEI10 revealed an extensive SC remodeling during prophase I. The ultrastructural investigations of the dynamics of these four proteins showed that the SC disassembly is accompanied by the retraction of the lateral and axial elements from the central region of the SC. In addition, SC fragmentation and the formation of ball-like SC structures occur at late diakinesis. Moreover, we show that the SC composition of rye B chromosomes does not differ from that of the standard (A) chromosome complement. Our ultrastructural investigations indicate that the dynamic behavior of the studied proteins is involved in SC formation and synapsis. In addition, they fulfill also functions during desynapsis and chromosome condensation to realize proper recombination and homolog separation. We propose a model for the homologous chromosome behavior during prophase I based on the observed dynamics of ASY1, ZYP1, NSE4A, and HEI10.

Metal-triggered fluorescence enhancement of multicolor carbon dots in sensing and bioimaging

In this paper, two multicolor CDs have been prepared with eco-friendly folic acid and glucose as precursors by means of a facile hydrothermal strategy. The microscopic and spectroscopic results comprehensively confirmed that both of them exhibited well-defined spherical particles, amorphous structures and similar surface chemistry properties, but with different lateral dimensions and element contents. Moreover, CDs1 and CDs2 show the favorable biocompatibility and low cytotoxicity, in vitro and in vivo CLSM images of HeLa cells and zebrafish larvae tagged with CDs1 and CDs2 revealed multicolor emission (blue, green and red) at different excitation wavelengths. More importantly, the fluorescence of CDs1 could be remarkably enhanced with the increase of Mn2+ concentration in aqueous solution through the bonding of Mn2+ with C–OH and N–H groups on the surface of CDs1. A wide linear range was obtained from 0.5 to 90 μM with a detection limit of 0.42 μM.

The E3 ubiquitin ligase Sina regulates the assembly and disassembly of the synaptonemal complex in Drosophila females.

During early meiotic prophase, homologous chromosomes are connected along their entire lengths by a proteinaceous tripartite structure known as the synaptonemal complex (SC). Although the components that comprise the SC are predominantly studied in this canonical ribbon-like structure, they can also polymerize into repeated structures known as polycomplexes. We find that in Drosophila oocytes, the ability of SC components to assemble into canonical tripartite SC requires the E3 ubiquitin ligase Seven in absentia (Sina). In sina mutant oocytes, SC components assemble into large rod-like polycomplexes instead of proper SC. Thus, the wild-type Sina protein inhibits the polymerization of SC components, including those of the lateral element, into polycomplexes. These polycomplexes persist into meiotic stages when canonical SC has been disassembled, indicating that Sina also plays a role in controlling SC disassembly. Polycomplexes induced by loss-of-function sina mutations associate with centromeres, sites of double-strand breaks, and cohesins. Perhaps as a consequence of these associations, centromere clustering is defective and crossing over is reduced. These results suggest that while features of the polycomplexes can be recognized as SC by other components of the meiotic nucleus, polycomplexes nonetheless fail to execute core functions of canonical SC.

Cyclic lateral load test and finite element analysis of high-strength concrete-filled steel box columns under high axial compression

This paper presents an experimental study of the seismic performance of high-strength concrete-filled box columns (CFBCs) under combined axial and cyclic lateral loads. Specimens were made of high-strength SM 570 M steel (with yield strengths between 520 and 580 MPa), and concrete with compressive strength (fc') greater than 80 MPa. Three parameters that affect the seismic performance of CFBCs were investigated: the width-to-thickness (b/t) ratio of the steel column, magnitude of the axial load, and the addition of concrete infill. The specimens, which were 280–420 mm in width and 2000 mm in height, were tested under combined axial (4058–10,090 kN) and cyclic lateral loads. Experimental results indicated that the lateral displacement ductility decreases significantly with an increase in either the axial load or b/t ratio. The addition of concrete infill inside a hollow steel box column does not improve the lateral displacement ductility of CFBCs under high axial load. Although the CFBC specimens satisfied the b/t requirement of a highly ductile member, as per AISC Seismic Provisions (2016), specimens under high axial load (40%Pn) failed at 4% drift, indicating that the requirement does not guarantee that CFBCs will sustain high axial load under significant drift (i.e., >3%). The Eurocode 4 (2009), AISC Specification (2010), and Architectural Institute of Japan (2014) reasonably estimate the flexural strength of high-strength CFBCs under axial load; however, ACI 318 (2011) does not. The finite element analysis program ABAQUS can be used to estimate the hysteretic behavior of specimens before significant strength degradation.

Disassembly of the synaptonemal complex in chicken oocytes analyzed by super-resolution microscopy.

The synaptonemal complex is an evolutionarily conserved, supramolecular structure that holds the homologous chromosomes together during the pachytene stage of the first meiotic prophase. Among vertebrates, synaptonemal complex dynamics has been analyzed in mouse spermatocytes following the assembly of its components from leptotene to pachytene stages. With few exceptions, a detailed study of the disassembly of SCs and the behavior of SC components at recombination sites at the onset of diplotene has not been accomplished. Here, we describe for the first time the progressive disassembly of the SC in chicken oocytes during the initial steps of desynapsis using immunolocalization of specific SC proteins and super-resolution microscopy. We found that transverse filament protein SYCP1 and central element component SYCE3 remain associated with the lateral elements at the beginning of chromosomal axis separation. As the separation between lateral elements widens, these proteins eventually disappear, without any evidence of subsequent association. Our observations support the idea that post-translational modifications of the central region components have a role at the initial phases of the SC disassembly. At the crossover sites, signaled by persistent MLH1 foci, the central region proteins are no longer detected when the SYCP3-positive lateral elements are widely separated. These findings are indicative that SC disassembly follows a general pattern along the desynaptic bivalents. The present work shows that the use of avian oocytes at prophase I provides a valuable model to explore the time course and chromosomal localization of SC proteins and its relationship with local changes along meiotic bivalents.

Experimental evaluation of the lateral load distribution in the elastic-plastic phase of timber-steel hybrid structures with a novel light timber-steel diaphragm

A cyclic loading experiment involving a timber-steel hybrid structure consisting of a steel frame and a novel light timber-steel diaphragm is presented to quantify the flexibility of the diaphragm and its ability to distribute lateral loads in the elastic-plastic phase of the structure. A lateral load-distribution factor was proposed, and its relationship to the ratio of the stiffness of the diaphragm to that of the lateral load-resisting elements was investigated. The diaphragm was classified based on these variables. The results indicated that the failure modes of the structure were associated with the forms of damage experienced by the lateral load-resisting elements, whereas little damage was observed for the diaphragm. The diaphragm exhibited the ability to continuously adjust the distribution of lateral loads to each lateral load-resisting element; accordingly, each lateral load-resisting element had approximately the same shear force, the same lateral stiffness, and the same lateral displacement during the loading process. As the lateral displacement increased, the stiffness ratio and load-distribution factor both gradually increased, and the diaphragm correspondingly changed from semi-rigid to rigid. At times, as the lateral displacement increased, the diaphragm rapidly became rigid, and it was unnecessarily rigid during the initial loading phase when the in-plane stiffness reached a certain threshold.

Small strain dynamic behavior of two types of carbonate sands

The study reports on the small-strain dynamic behavior of two types of carbonate sands from Western Australia and the Philippines. Basic characterization of the soils was performed in terms of specific gravity, grading information, angle of shear strength at critical state, particle shape characterization and composition analysis. Piezo-element inserts were utilized to carry out the dynamic tests. For the Western Australia (WA) carbonate sand, both bender and extender element tests were performed, thus the shear modulus, the Young’s modulus and the Poisson’s ratio were examined. Both vertical and lateral bender element tests were performed on a set of specimens from the Philippines (PH) carbonate sand to study the shear modulus and, from which, no fabric anisotropy of the reconstituted specimens was found. It was observed that the overconsolidated specimens had higher stiffness than those during the first loading stages for both carbonate sands. In the pressure range of the study, grain breakage was small and its effect on the behavior of the samples was almost negligible. Empirical equations in the literature proposed from quartz sands could not predict the stiffness of the carbonate soils satisfactorily. In this regard, a preliminary study was carried out adopting the assumed void ratio that only considers the inter-particle voids instead of the summation of inter- and intra-particle voids; based on this concept, the predicted and measured stiffness (including both small-strain shear modulus, Gmax and small-strain Young’s modulus, Emax) were found to be satisfactorily close.

Male Meiotic Recombination in the Steppe Agama, Trapelus sanguinolentus (Agamidae, Iguania, Reptilia)

Meiotic recombination rates and patterns of crossover distributions along the chromosomes vary considerably even between closely related species. The adaptive significance of these differences is still unclear due to the paucity of empirical data. Most data on recombination come from mammalian species, while other vertebrate clades are poorly explored. Using immunolocalization of the protein of the lateral element of the synaptonemal complex (SYCP3) and the mismatch-repair protein MLH1, which marks mature recombination nodules, we analyzed recombination rates and crossover distribution in meiotic prophase chromosomes of the steppe agama (Trapelus sanguinolentus, Agamidae, Acrodonta, Iguania) and compared them with data obtained for the genus Anolis (Dactyloidae, Pleurodonta, Iguania). We found that, despite a smaller genome size, the total SC length and the MLH1 focus number per cell are much higher in the agama than in the anoles. The distributions of the MLH1 foci in the agama are multimodal in larger chromosomes and bimodal in smaller chromosomes without a significant centromere effect, resembling the patterns known for birds. A possible relationship between karyotype remodeling and the evolution of recombination in Iguania is discussed.

Progressive collapse potential of different types of irregular buildings located in diverse seismic sites

This paper evaluates the effects of severity of Torsional Irregularity (TI) and In-plane Discontinuity in Vertical Lateral force-resisting element Irregularity (IDVLI) together with seismic strength of the building on the progressive collapse potential of steel Special Moment-Resisting Frames (steel SMRFs), which were designed based on common seismic codes. In order to investigate the progressive collapse potential according to GSA 2013 guidelines, an interior or exterior column is removed in 3D modeled building using nonlinear dynamic analysis. Various TIs by defining the ratio of maximum relative lateral displacement of the story to average relative lateral displacement of the story between 1 to 1.6 and IDVLIs by disconnecting one or two columns in the first and second stories are selected. Buildings are 3, 6 and 9 stories high, and Los Angeles, California andGeorgia sites with high, moderate and low levels of seismicity, respectively, are considered. All corresponding buildings have similar seismic mass and are designed for approximately equal values of earthquake base shear, so the comparison process can be possible due to the comparison of equivalent-designed buildings. Gravity and seismic loads of buildings are applied based on ASCE 7-05, and steel design is carried out based on AISC 2010. The results show that buildings designed with greater TI have greater resistance to the progressive collapse phenomenon. Furthermore, buildings in a site with higher seismicity level have less progressive collapse potential. In IDVLI, the buildings located in a site with low seismicity are always rejected against progressive failure based on GSA 2013, whereas buildings located in a site with high seismicity are always acceptable. In addition, in a system with IDVLI, the scenario of external column removal always creates more critical conditions. Results toward the combined effects of irregularity and seismicity level of sites are presented.