Arrangement Of Filaments Research Articles

Architectural dissection of adhesive bacterial cell surface appendages from a "molecular machines" viewpoint.

The ability of bacteria to interact with and respond to their environment is crucial to their lifestyle and survival. Bacterial cells routinely need to engage with extracellular target molecules, in locations spatially separated from their cell surface. Engagement with distant targets allows bacteria to adhere to abiotic surfaces and host cells, sense harmful or friendly molecules in their vicinity, as well as establish symbiotic interactions with neighboring cells in multicellular communities such as biofilms. Binding to extracellular molecules also facilitates transmission of information back to the originating cell, allowing the cell to respond appropriately to external stimuli, which is critical throughout the bacterial life cycle. This requirement of bacteria to bind to spatially separated targets is fulfilled by a myriad of specialized cell surface molecules, which often have an extended, filamentous arrangement. In this review, we compare and contrast such molecules from diverse bacteria, which fulfil a range of binding functions critical for the cell. Our comparison shows that even though these extended molecules have vastly different sequence, biochemical and functional characteristics, they share common architectural principles that underpin bacterial adhesion in a variety of contexts. In this light, we can consider different bacterial adhesins under one umbrella, specifically from the point of view of a modular molecular machine, with each part fulfilling a distinct architectural role. Such a treatise provides an opportunity to discover fundamental molecular principles governing surface sensing, bacterial adhesion, and biofilm formation.

Salvia tainingensis, a neglected new species of Lamiaceae from Fujian Province, China

A species could not be known to the world of science if it not be discovered and described, considerable number of new species are neglected due to the plant itself and some other external restricted factors. On the basis of morphological and molecular evidences, a new species previously identified as Salvia scapiformis is now described and illustrated as Salvia tainingensis, named after Taining County in Fujian Province, where it was discovered. S. tainingensis does not closely resemble S. scapiformis, but is more similar to Salvia glabrifolia and Salvia daiguii, which were once identified as S. scapiformis, in terms of leaf shape, apex, base, corolla color, and connective length. However, it can be easily distinguished from the latter two by its thinly leathery leaves, serrate leaf margins, densely villous or glabrescent leaf abaxial, and the X-shaped arrangement of connective and filament.

Fog water collection of harp-like single smooth and texturized filaments under field conditions

Harp-like arrangements of filaments have been proposed as a more efficient alternative to cross-linked screens for fog water collection. We investigate the fog capture capabilities of both smooth and texturized single vertical nylon threads under field conditions. Redefining the Stokes number in terms of the wetted string and the pinning drop geometry allowed the average fog water collection efficiency to be described using a physically based droplet impaction model with acceptable fit (NSE = 0.614; RMSE = 0.093). In addition, rugosity of the filaments was found to affect the long-term fog water yield (up to 41 % lower), while parallel grooves along the filaments maximised the fog collection, with 51 % improvement, under real field conditions.

Microstructure-based nuclear lamina constitutive model.

The nuclear lamina is widely recognized as the most crucial component in providing mechanical stability to the nucleus. However, it is still a significant challenge to model the mechanics of this multilayered protein network. We developed a constitutive model of the nuclear lamina network based on its microstructure, which accounts for the deformation phases at the dimer level, as well as the orientational arrangement and density of lamin filaments. Instead of relying on homology modeling in the previous studies, we conducted molecular simulations to predict the force-extension response of a highly accurate lamin dimer structure obtained through X-ray diffraction crystallography experimentation. Furthermore, we devised a semiflexible worm-like chain extension-force model of lamin dimer as a substitute, incorporating phases of initial stretching, uncoiling of the dimer coiled-coil, and transition of secondary structures. Subsequently, we developed a 2D network continuum model for the nuclear lamina by using our extension-force lamin dimer model and derived stress resultants. By comparing with experimentally measured lamina modulus, we found that the lamina network has sharp initial strain-hardening behavior. This also enabled us to carry out finite element simulations of the entire nucleus with an accurate microstructure-based nuclear lamina model. Finally, we conducted simulations of transendothelial transmigration of a nucleus and investigated the impact of varying network density and uncoiling constants on the critical force required for successful transmigration. The model allows us to incorporate the microstructure characteristics of the nuclear lamina into the nucleus model, thereby gaining insights into how laminopathies and mutations affect nuclear mechanics.

Asymmetric response emerges between creation and disintegration of force-bearing subcellular structures as revealed by percolation analysis.

Cells dynamically remodel their internal structures by modulating the arrangement of actin filaments (AFs). In this process, individual AFs exhibit stochastic behavior without knowing the macroscopic higher-order structures they are meant to create or disintegrate, but the mechanism allowing for such stochastic process-driven remodeling of subcellular structures remains incompletely understood. Here we employ percolation theory to explore how AFs interacting only with neighboring ones without recognizing the overall configuration can nonetheless create a substantial structure referred to as stress fibers (SFs) at particular locations. We determined the interaction probabilities of AFs undergoing cellular tensional homeostasis, a fundamental property maintaining intracellular tension. We showed that the duration required for the creation of SFs is shortened by the increased amount of preexisting actin meshwork, while the disintegration occurs independently of the presence of actin meshwork, suggesting that the coexistence of tension-bearing and non-bearing elements allows cells to promptly transition to new states in accordance with transient environmental changes. The origin of this asymmetry between creation and disintegration, consistently observed in actual cells, is elucidated through a minimal model analysis by examining the intrinsic nature of mechano-signal transmission. Specifically, unlike the symmetric case involving biochemical communication, physical communication to sense environmental changes is facilitated via AFs under tension, while other free AFs dissociated from tension-bearing structures exhibit stochastic behavior. Thus, both the numerical and minimal models demonstrate the essence of intracellular percolation, in which macroscopic asymmetry observed at the cellular level emerges not from microscopic asymmetry in the interaction probabilities of individual molecules, but rather only as a consequence of the manner of the mechano-signal transmission. These results provide novel insights into the role of the mutual interplay between distinct subcellular structures with and without tension-bearing capability. Insight: Cells continuously remodel their internal elements or structural proteins in response to environmental changes. Despite the stochastic behavior of individual structural proteins, which lack awareness of the larger subcellular structures they are meant to create or disintegrate, this self-assembly process somehow occurs to enable adaptation to the environment. Here we demonstrated through percolation simulations and minimal model analyses that there is an asymmetry in the response between the creation and disintegration of subcellular structures, which can aid environmental adaptation. This asymmetry inherently arises from the nature of mechano-signal transmission through structural proteins, namely tension-mediated information exchange within cells, despite the stochastic behavior of individual proteins lacking asymmetric characters in themselves.

Toxic effects of triclocarban on the histological morphology, physiological and immune response in the gills of the black tiger shrimp Penaeus monodon

Triclocarban (TCC) is a widely used broad-spectrum antimicrobial agent that has become a pollutant threatening the health of aquatic animals. However, the toxic effects of TCC on Penaeus monodon are still lacking. In this study, we exposed P. monodon to 1 μg/L (TCC-1) and 10 μg/L TCC (TCC-10) for 14 days, and the changes of histological morphology, physiological and immune responses in the gills were investigated. The results showed that TCC exposure caused the deformation of the gill vessels and the disordered arrangement of the gill filaments. Oxidative stress biochemical indexes such as H2O2 content, CAT and GPx activity and the relative expression levels of antioxidant-related genes (SOD, GPx and Nrf2) were increased in the TCC-1 and TCC-10 groups; the levels of CAT and HSP70 genes were increased but POD activity was decreased in the TCC-10 group. The relative expression levels of endoplasmic reticulum (ER) stress indexes such as ERP15 and ATF-6 genes were increased in the TCC-10 group, while the level of GRP78 gene was decreased in the TCC-1 and TCC-10 groups. The relative expression levels of apoptosis indexes such as p53 and JNK genes were increased, but CytC and Casp-3 genes were decreased in the TCC-1 and TCC-10 groups. Furthermore, the relative expression levels of detoxification metabolism-related genes (cytP450 and GST) and osmotic regulation-related genes (NKA-α, NKA-β, CA, AQP, CLC and CCP) were increased in the TCC-10 group. The results showed that TCC exposure could affect the physiological homeostasis in the gills of P. monodon, probably via damaging histological morphology, inducing oxidative stress, and disordering ER stress, apoptosis, detoxification and osmotic regulation.

Origin and arrangement of actin filaments for gliding motility in apicomplexan parasites revealed by cryo-electron tomography

The phylum Apicomplexa comprises important eukaryotic parasites that invade host tissues and cells using a unique mechanism of gliding motility. Gliding is powered by actomyosin motors that translocate host-attached surface adhesins along the parasite cell body. Actin filaments (F-actin) generated by Formin1 play a central role in this critical parasitic activity. However, their subcellular origin, path and ultrastructural arrangement are poorly understood. Here we used cryo-electron tomography to image motile Cryptosporidium parvum sporozoites and reveal the cellular architecture of F-actin at nanometer-scale resolution. We demonstrate that F-actin nucleates at the apically positioned preconoidal rings and is channeled into the pellicular space between the parasite plasma membrane and the inner membrane complex in a conoid extrusion-dependent manner. Within the pellicular space, filaments on the inner membrane complex surface appear to guide the apico-basal flux of F-actin. F-actin concordantly accumulates at the basal end of the parasite. Finally, analyzing a Formin1-depleted Toxoplasma gondii mutant pinpoints the upper preconoidal ring as the conserved nucleation hub for F-actin in Cryptosporidium and Toxoplasma. Together, we provide an ultrastructural model for the life cycle of F-actin for apicomplexan gliding motility.

(197) Hormone Receptor Distribution and Innervation in Neuroproliferative Vestibulodynia: Immunohistochemical Evidence

Abstract Introduction There are limited hormonal and neurological studies of the vestibule despite its importance to sexual health and its pathophysiologic role in entrance dyspareunia. It is widely accepted that the vulva and vagina have estrogen receptors, but little is known regarding the types and density of various hormone receptors in the vestibule. Tactile and pressure sensations of the vestibule during sexual activity are likely transmitted via pudendal (somatic) and pelvic (visceral) nerve branches. The vestibule also releases mucinous lubrication from minor and major vestibular glands, likely induced by efferent pelvic (parasympathetic) nerve activation and terminated by efferent hypogastric (sympathetic) nerve activation. Immunohistochemical (IHC) studies of nerve structures and of androgen, estrogen, progesterone receptors in human vestibular tissue would aid in better understanding of relevant physiologic functions of the vestibule. Objective To better understand vestibular hormonal and neurological physiology through IHC studies of vestibulectomy tissue and to help improve clinical management of vestibulodynia. Methods IHC was performed on 7 vestibular specimens with confirmation of NPV diagnosis by positive CD117 and PGP9.5 staining, consistent with excess mast cells and nerve endings, respectively. Specimens were also studied with primary antibodies (Anti-ERα, Ab 32063; Anti-AR, MI 06680; Anti-PR, Dako PGR636; Anti-Synapsin, Cell Signaling 5297T). Finally, sections were lightly counterstained with Gill-modified hematoxylin. Results Androgen and estrogen alpha receptors were richly expressed in tissue samples of all 7 patients. Dense labeling of both receptor types was noted in the germinal layer of the epithelium (Fig. 1a,b) and mucinous vestibular glands (Fig. 2a,b), with comparatively sparse expression in the subepithelial stroma. While labeling of progesterone receptors was highly variable (Fig. 3a,b), all samples showed evidence of moderate progesterone receptor labeling in the subepithelial stroma. Variability may be due to menstrual cycle phase in which samples were obtained. Synapsin labeling showed thin filamentous arrangement in the rete pegs, thicker filamentous arrangement in the subepithelial stroma, and dense labeling in blood vessel endothelium and epithelium of mucinous vestibular glands (Fig, 4a, b). Conclusions This preliminary study provides evidence of dense androgen and estrogen receptor expression in the vestibule, consistent with the observation that in patients with hormonal deficiency, entrance dyspareunia may be more successfully treated at the vestibule with combined testosterone and estradiol cream than with topical estradiol alone. Also consistent with these findings is that treatment with intravaginal DHEA, converted to testosterone and estradiol intracrinologically and subsequently diffusing to the vestibule, successfully resolves entrance dyspareunia. While the significance of variable vestibular progesterone receptor expression is unclear, the addition of topical progesterone in these patients may be considered. Synapsin staining in rete pegs, stroma, surrounding blood vessels, and mucinous vestibular glands supports functional sensory innervation and autonomic regulation of vestibular lubrication that occurs during sexual activity. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Endoceutics.

Actin cytoskeleton in the control of vesicle transport, cytoplasmic organization, and pollen tube tip growth.

Pollen tubes extend rapidly via tip growth. This process depends on a dynamic actin cytoskeleton, which has been implicated in controlling organelle movements, cytoplasmic streaming, vesicle trafficking, and cytoplasm organization in pollen tubes. In this update review, we describe the progress in understanding the organization and regulation of the actin cytoskeleton and the function of the actin cytoskeleton in controlling vesicle traffic and cytoplasmic organization in pollen tubes. We also discuss the interplay between ion gradients and the actin cytoskeleton that regulates the spatial arrangement and dynamics of actin filaments and the organization of the cytoplasm in pollen tubes. Finally, we describe several signaling components that regulate actin dynamics in pollen tubes.

Liquid-like assembly of VASP catalyzes actin polymerization and bundling.

Actin filament bundling underlies many critical cellular processes including morphogenesis, cell division, and motility. Actin filament bundling is regulated by a family of actin-binding proteins. Recent work has revealed that several proteins comprising this cytoskeletal network have been found to undergo liquid-liquid phase separation. How might liquid-like phases contribute to filament organization and bundling? Here, we show that the processive actin polymerase and bundling protein, VASP, forms liquid-like droplets under physiological conditions. These VASP droplets catalyze actin polymerization and bundling through a mechanism that depends on the relative material properties of the filaments and the droplets. Specifically, as actin polymerizes within VASP droplets, elongating filaments partition to the perimeter of the droplet to minimize filament curvature, forming an actin-rich ring within the droplet. The rigidity of this ring is balanced by the droplet's surface tension, as predicted by a continuum-scale computational model. However, as actin polymerizes and the ring grows thicker, its rigidity increases and eventually overcomes the surface tension of the droplet, deforming into a linear bundle. The resulting bundles contain long, parallel actin filaments that grow from their tips, reminiscent of filopodia. Once the parallel arrangement of filaments is created within a VASP droplet, it propagates through the addition of new actin monomers to achieve a length that is many times greater than the initial droplet. Significantly, the fluid nature of the droplets is critical for bundling, as more solid droplets resist deformation by preventing the rearrangement of filaments that is necessary to form bundles. These results reveal a novel mechanism of filament bundling that may be relevant to the assembly of cellular architectures such as filopodia, stress fibers, and focal adhesions.

Discovery of a new black fly species in the Simulium (Simulium) striatum species-group (Diptera: Simuliidae) from northeastern Thailand and its phylogenetic relationships with seven Thai related species

The female, male, pupa and mature larva of Simulium (Simulium) poolpholi sp. nov. collected from a large and seasonal stream in northeastern Thailand are described. This new species is placed in the S. striatum species-group by the female sternite 8 concave posteromedially in form of the inverted-U shape, ovipositor valve with a ventrally produced process along its inner margin, male ventral plate saddle-shaped, style with a basal protuberance, and pupal gill with 10 filaments. It is morphologically similar to S. (S.) phraense Takaoka, Srisuka & Saeung from northern Thailand by lacking annular ridges on the surface of pupal gill filaments but it is distinguished from the latter species by the arrangement of pupal gill filaments. Molecular analysis using the fast-evolving nuclear big zinc finger (BZF) gene shows that S. (S.) poolpholi sp. nov. formed a distinct clade, being separated from the seven other Thai species of this species-group by a genetic distance of 1.84–4.55%. Our discovery increases the number of species in the S. striatum species-group in Thailand to nine.

From qualitative data to correlation using deep generative networks: Demonstrating the relation of nuclear position with the arrangement of actin filaments.

The cell nucleus is a dynamic structure that changes locales during cellular processes such as proliferation, differentiation, or migration, and its mispositioning is a hallmark of several disorders. As with most mechanobiological activities of adherent cells, the repositioning and anchoring of the nucleus are presumed to be associated with the organization of the cytoskeleton, the network of protein filaments providing structural integrity to the cells. However, demonstrating this correlation between cytoskeleton organization and nuclear position requires the parameterization of the extraordinarily intricate cytoskeletal fiber arrangements. Here, we show that this parameterization and demonstration can be achieved outside the limits of human conceptualization, using generative network and raw microscope images, relying on machine-driven interpretation and selection of parameterizable features. The developed transformer-based architecture was able to generate high-quality, completed images of more than 8,000 cells, using only information on actin filaments, predicting the presence of a nucleus and its exact localization in more than 70 per cent of instances. Our results demonstrate one of the most basic principles of mechanobiology with a remarkable level of significance. They also highlight the role of deep learning as a powerful tool in biology beyond data augmentation and analysis, capable of interpreting-unconstrained by the principles of human reasoning-complex biological systems from qualitative data.

Spaghetti Tracer: A Framework for Tracing Semiregular Filamentous Densities in 3D Tomograms.

Within cells, cytoskeletal filaments are often arranged into loosely aligned bundles. These fibrous bundles are dense enough to exhibit a certain regularity and mean direction, however, their packing is not sufficient to impose a symmetry between—or specific shape on—individual filaments. This intermediate regularity is computationally difficult to handle because individual filaments have a certain directional freedom, however, the filament densities are not well segmented from each other (especially in the presence of noise, such as in cryo-electron tomography). In this paper, we develop a dynamic programming-based framework, Spaghetti Tracer, to characterizing the structural arrangement of filaments in the challenging 3D maps of subcellular components. Assuming that the tomogram can be rotated such that the filaments are oriented in a mean direction, the proposed framework first identifies local seed points for candidate filament segments, which are then grown from the seeds using a dynamic programming algorithm. We validate various algorithmic variations of our framework on simulated tomograms that closely mimic the noise and appearance of experimental maps. As we know the ground truth in the simulated tomograms, the statistical analysis consisting of precision, recall, and F1 scores allows us to optimize the performance of this new approach. We find that a bipyramidal accumulation scheme for path density is superior to straight-line accumulation. In addition, the multiplication of forward and backward path densities provides for an efficient filter that lifts the filament density above the noise level. Resulting from our tests is a robust method that can be expected to perform well (F1 scores 0.86–0.95) under experimental noise conditions.

Spef1/CLAMP binds microtubules and actin-based structures and regulates cell migration and epithelia cell polarity.

During migration, cells invade, repair, and create barriers leading to the formation of new cellular contacts in target tissues. Cell migration requires many proteins that collectively form the cytoskeleton. The main cytoskeletal elements are actin filaments, microtubules (MTs), and intermediate filaments. These structures work in concert with a large number of accessory proteins that contribute in a variety of ways to regulate filament assembly and turnover, to alter the configuration or arrangement of filaments by bundling or crosslinking, to link the cytoskeleton to other structures in the cell, such as membranes and junctions, and to transport cargo along the filaments. Sperm flagella protein-1 (Spef1), also designated calponin homology and microtubules-associated protein (CLAMP), is a multifunctional protein that interacts with cytoskeletal structures, including MTs, actin filaments, and focal adhesions in epithelia. In this review, we outline Spef1/CLAMP structure and expression in several cellular models. The function of Spef1/CLAMP in flagellar and ciliary motility, MT-binding and stability, regulation of planar cell polarity, and potential contribution to the maintenance of actin-based structures, such as lamellipodia and filopodia during cell migration, are also discussed.

Optimum Filament Positions Within a MgB$_{2}$ Wire Resulting in Maximum Reduction of AC Losses

Transport current capability of MgB <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_{2}$</tex-math></inline-formula> multifilamentary wires is intrinsically affected by the self and mutual magnetic inductance between superconducting filaments, which is a problem that depends on the geometrical distribution of the filaments. Any rise on this magnetic interaction can cause an increase in the AC losses of the system, which counteracts the efficiency of the wire and rises the cryogenics costs. Thus, in order to reduce the AC losses of multifilamentary MgB <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_{2}$</tex-math></inline-formula> wires by finding an optimal arrangement of the MgB <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_{2}$</tex-math></inline-formula> filaments, we present a comprehensive study for the optimal positioning of up to 7 and 13 filament wire configurations as common benchmarks. Varying the positions of the filaments within the copper matrix has shown a remarkable reduction in the AC losses of up to 60 <bold xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><inline-formula><tex-math notation="LaTeX">$\%$</tex-math></inline-formula></b> the standard losses, a phenomenon which we have explained as a function of the calculated distributions of current density and magnetic field for the new wire designs. Likewise, a sudden rise in the AC losses of the multifilamentary wires with concentric arrangements of filaments has been found under certain configurations, where the magnetic saturation of the outer filaments can cause a notorious rise in the AC losses. This reveals how some multifilamentary designs can show enhanced energy loss characteristics whilst maintaining the same transport current conditions if a proper arrangement of the MgB <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_{2}$</tex-math></inline-formula> wires is conceived prior to its manufacturing.

An enhancer sequence in the intrinsically disordered region of FtsZ promotes polymer-guided substrate processing by ClpXP protease.

The essential bacterial division protein in Escherichia coli, FtsZ, assembles into the FtsZ-ring at midcell and recruits other proteins to the division site to promote septation. A region of the FtsZ amino acid sequence that links the conserved polymerization domain to a C-terminal protein interaction site was predicted to be intrinsically disordered and has been implicated in modulating spacing and architectural arrangements of FtsZ filaments. While the majority of cell division proteins that directly bind to FtsZ engage either the polymerization domain or the C-terminal interaction site, ClpX, the recognition and unfolding component of the bacterial ClpXP proteasome, has a secondary interaction with the predicted intrinsically disordered region (IDR) of FtsZ when FtsZ is polymerized. Here, we use NMR spectroscopy and reconstituted degradation reactions in vitro to demonstrate that this linker region is indeed disordered in solution and, further, that amino acids in the IDR of FtsZ enhance the degradation in polymer-guided interactions.

A new species of the Simulium (Simulium) striatum species-group (Diptera: Simuliidae) from Thailand: Description and phylogenetic relationship with its Thai members

Simulium (Simulium) thilorsuense sp. nov. is described from females, males, pupae and mature larvae in Thailand. It is placed to the S. striatum species-group, and is distinguished from all the seven species of this species-group recorded from Thailand in the male by the greater number of male upper-eye (large) facets in 20 vertical columns and 19 or 20 horizontal rows, and in the pupa by the combination of the arrangement (2+3+3+2 from dorsal to ventral) and subequal thickness of gill filaments, and tubercles on the frons without secondary projection. It is similar in the female, male and pupa to S. (S.) pingtungense Huang & Takaoka from Taiwan but is distinguished in the larva by the presence of paired protuberances on abdominal segments 1–8 (absence in the latter species). It is similar to S. (S.) grisescens Brunetti from India, S. (S.) perakense Takaoka &Ya'cob from Peninsular Malaysia, and S. (S.) taythienense Takaoka, Sofian-Azirun & Ya'cob from Vietnam by sharing many characteristics including the haired basal portion of the female radius, dark legs of both female and male, male scutum with brassy short hairs, pupal gill with 10 filaments of the almost same thickness, arranged as 2+3+3+2 from dorsal to ventral, and larval abdomen with paired dorsal protuberances, but is distinguished from these three species by the greater number of male upper-eye (large) facets. Our genetic analysis using the fast-evolving nuclear big zinc finger (BZF) gene sequences revealed that this new species has an intraspecific variation ranging from 0.00% to 1.38%, and is separated from six Thai known species of the S. striatum species-group with an interspecific variation of 2.00–4.56%.

Experimental evaluation of variable thickness 3D printing of continuous carbon fiber-reinforced composites

Conventional 3D printers automatically create complex continuous carbon fiber-reinforced polymer (CFRP) composite structures with excellent specific strength and specific stiffness. However, such printing is performed at a constant thickness, which neither provides design freedom in the thickness direction nor an optimal arrangement of CFRP filaments. This study experimentally verified a high-degree-of-freedom 3D printing method in which the layer thickness and path width were controlled by changing the nozzle height during the CFRP printing. From the basic verification of changing the layer thickness, the range where the thickness change is possible was determined. In addition, the fiber orientation and layer thickness were optimized based on the stress distribution for the open-hole tensile problem. Three types of specimens based on constant-thickness straight-line (CTSL) model, optimized fiber path model, and optimized fiber path and thickness (OFPT) model, were prepared and their weight and tensile properties were evaluated. The results showed that the OFPT model successfully reduced the weight by 4.51% and increased the strength by 15.3% compared to the CTSL model.

Tracing Filaments in Simulated 3D Cryo-Electron Tomography Maps Using a Fast Dynamic Programming Algorithm.

We propose a fast, dynamic programming-based framework for tracing actin filaments in 3D maps of subcellular components in cryo-electron tomography. The approach can identify high-density filament segments in various orientations, but it takes advantage of the arrangement of actin filaments within cells into more or less tightly aligned bundles. Assuming that the tomogram can be rotated such that the filaments can be oriented to be directed in a dominant direction (i.e., the , , or axis), the proposed framework first identifies local seed points that form the origin of candidate filament segments (CFSs), which are then grown from the seeds using a fast dynamic programming algorithm. The CFS length can be tuned to the nominal resolution of the tomogram or the separation of desired features, or it can be used to restrict the curvature of filaments that deviate from the overall bundle direction. In subsequent steps, the CFSs are filtered based on backward tracing and path density analysis. Finally, neighboring CFSs are fused based on a collinearity criterion to bridge any noise artifacts in the 3D map that would otherwise fractionalize the tracing. We validate our proposed framework on simulated tomograms that closely mimic the features and appearance of experimental maps.

Redescription of Simulium (Gomphostilbia) omutaense Ogata & Sasa (Diptera: Simuliidae) from Japan and its phylogenetic relationship with other members of the S. batoense species-group

Simulium (Gomphostilbia) omutaense Ogata & Sasa, 1954 is the only named species in the Simulium batoense species-group of the subgenus Gomphostilbia Enderlein recorded from Honshu and Kyushu, Japan. It represents the northernmost distribution of this species-group, of which most members are distributed in the Oriental region. This species, the only member of the Simulium omutaense subgroup, is unique among the seven subgroups of the S. batoense species-group by having the pupal gill with one long filament and seven short filaments, similar to the arrangement of the pupal gill filaments in the S. zonatum subgroup of the S. epistum species-group in the same subgenus. This species is fully redescribed based on adults, pupal exuviae and mature larvae, and is most similar to species of the S. decuplum subgroup, based on adult morphological characteristics, although the pupal gill of the latter subgroup is markedly different by having 10 or 12 short filaments. Its close relationship to the S. decuplum subgroup is supported by a DNA analysis using COI gene sequences, with genetic distances of 9.30–11.02%. On the other hand, genetic distances between S. (G.) omutaense and species of the S. zonatum subgroup were 16.32–16.93%. Our study shows that a similar arrangement of the pupal gills in two different species-groups, which is rarely seen, has evolved independently and its occurrence does not necessarily reflect phylogenetic relationships.