Alternative Sequences Research Articles

Ultra-short-term forecasting of wind power based on multi-task learning and LSTM

In order to achieve high precision ultra-short-term prediction of wind power, a new ultra-short-term prediction method for wind power is proposed by combining the maximal information coefficient (MIC) with multi-task learning (MTL) and long short-term memory (LSTM) network. First, the correlation analysis method is used to analyze the MIC correlation of wind power sequence and wind speed sequence, the MIC correlation between the alternative sequence, the wind power sequence and the wind speed sequence, respectively. The feature input sequence of the neural network is constructed base on the correlation analysis results. Second, taking wind speed prediction as the auxiliary task and wind power prediction as the main task, LSTM based prediction network was constructed using MTL framework, and the network parameters were optimized by grid search. Finally, based on the historical data of a wind farm in the United States, the case study verifies that the proposed method gains higher prediction accuracy than other existing methods modeling wind speed as a feature, such as single-task LSTM neural network, BP neural network and traditional ARIMA model.

Abstract OT2-22-02: Sequencing of anthracyclines and taxanes during neoadjuvant therapy of locally advanced HER2-negative breast cancer (NEOSAMBA Study/LACOG 0419)

Abstract Background: Breast cancer (BC) is the most frequent cancer in women in Brazil, with more than 60,000 cases estimated annually. Forty percent of patients present with stages III and IV and neoadjuvant chemotherapy (NACT) remains the mainstay of treatment for locally advanced breast cancer (LABC). Taxanes usually follow anthracyclines in breast cancer neo/adjuvant treatment, likely because of their later introduction into clinical practice. However, the potential impact of alternative sequencing remains to be studied. A single-center phase II randomized clinical trial conducted in the Brazilian National Cancer Institute showed an improvement in overall survival with taxane-first compared with anthracycline-first sequencing in HER2-negative LABC (Bines J et al, The Oncologist 2020). As a taxane-before-anthracycline sequence carries neither an incremental cost nor increased toxicity, the optimal sequencing of these agents could have significant implications for clinical practice. To confirm this finding, we are currently conducting a multicenter randomized phase III trial comparing a taxane followed by an anthracycline-based regimen with the reverse sequence in the neoadjuvant setting. Trial Design: This randomized, open-label, phase III trial will be conducted in 15 research centers in Brazil. It was approved by the local ethics committee in 2020 and is registered in Clinicatrials.gov with the identifier NCT04540692. Women with HER2-negative LABC are randomized in a 1:1 ratio to anthracycline-before-taxane (AC-T arm) or taxane-before-anthracycline (T-AC arm), stratified by hormone receptor status (positive vs. negative) and axillary lymph node status (N0 vs. N+). The anthracycline-based therapy recommended in this trial is AC (doxorubicin 60 mg/m2 and cyclophosphamide 600 mg/m2) every three weeks for four cycles, whilst the taxane-based therapy is either weekly paclitaxel 80 mg/m2 weekly for 12 weeks, paclitaxel 175 mg/m2 every three weeks, or docetaxel 75-100 mg/m2 every three weeks. The use of carboplatin concomitantly with taxane for triple-negative tumors and dose-dense regimens is allowed following institutional guidelines. Further therapies (surgery, radiotherapy, and endocrine therapy) are performed according to the physicians’ discretion. Tumor samples are collected and stored for translational studies. Eligibility: Inclusion criteria: women ≥18 years of age; histologically confirmed HER2-negative breast cancer (by ASCO/CAP guidelines); stage ≥ IIB (if TNBC) or ≥ III (if HR-positive); PS ECOG 0-2 and adequate organ function. Exclusion criteria: previous use of anti-cancer therapies; bilateral BC and pregnancy. Specific Aims: The primary objective is invasive disease-free survival (iDFS). Secondary objectives include pathological complete response (pCR) rates, overall survival (OS) and safety. Statistical Methods: Considering an unicaudal type I error of 0.05, a type II error of 0.2, and an estimated iDFS of 50% in 5 years in the control arm, a total of 227 evaluable patients should be included per arm to demonstrate a HR of 0.7 favoring the taxane-first arm. Estimating a dropout rate of 10%, 494 patients will need to be included in the study. Present Accrual and Target Accrual: A total of 9 sites of 15 planned are activated. The first patient was enrolled on January 12, 2021, and as of June 24, 2022, a total of 113 patients have been accrued. The target goal of 494 patients is expected to be achieved by 2025 and initial study results will be reported by 2026. Funding: Brazilian Health MInistry, Programa Nacional de Apoio à Atenção Oncológica (PRONON), NUP 25000.183207/2019-50. Acknowledgements: CURA Project, SAS. Citation Format: Tomás Reinert, Cristiano P. Souza, Pedro Liedke, Gustavo Werutsky, Laura Testa, Vivian Antunes, Carlos Barrios, Vivian Vasconcelos, Heloísa Resende, Geraldo Silva Queiroz, Gisah Guilgen, Yeni Nerón, Lilian Arruda Bastos, Sabina Aleixo, Daniel Cubero, Maria Cristina F. Magalhães, Ana Coradazzi, Daniela Galvão B. de Oliveira, João S. Nunes, Rafaela G. Jesus, Gustavo Gössling, José Bines. Sequencing of anthracyclines and taxanes during neoadjuvant therapy of locally advanced HER2-negative breast cancer (NEOSAMBA Study/LACOG 0419) [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr OT2-22-02.

Chemoresistance in acute myeloid leukemia: An alternative single-cell RNA sequencing approach.

Our previous study demonstrated that myc, mitochondrial oxidative phosphorylation, mTOR, and stemness are independently responsible for chemoresistance in acute myeloid leukemia (AML) cells. This study aimed to identify potential mechanisms of chemoresistance of the "7+3" induction in AML by using a single-cell RNA sequencing (scRNA-seq) approach. In the present study, 13 untreated patients with de novo AML were enrolled and stratified into two groups: complete remission (CR; n=8) and non-CR (n=5). Single-cell RNA sequencing was used to analyze genetic profiles of 28,950 AML cells from these patients; results were validated using a previously published bulk RNA-seq dataset. Our study results showed chemoresistant AML cells had premature accumulation during early hematopoiesis. Hematopoietic stem cell-like cells from the non-CR group expressed more leukemic stem cell markers (CD9, CD82, IL3RA, and IL1RAP) than those from the CR group. Chemoresistant progenitor cells had impaired myeloid differentiation owing to early arrest of hematopoiesis. Notably, AML cells analyzed by scRNA-seq and bulk RNA-seq harbored a comparable myeloid lineage cell fraction, which internally validated our results. Using the TCGA database, our analysis demonstrated that patients with AML with higher expression of chemoresistant genetic markers (IL3RA and IL1RAP) had a worse overall survival (p<0.01 for IL3RA; p<0.05 for IL1RAP). In conclusion, AML cells responsive and resistant to the "7+3" induction were derived from a diverse cancerous hematopoietic stem cell population, as indicated by the specific genetic biomarkers obtained using scRNA-seq approach. Furthermore, arrest of hematopoiesis was shown to occur earlier in chemoresistant AML cells, furthering the current understanding of chemoresistance in AML.

Early Selection of the Amino Acid Alphabet Was Adaptively Shaped by Biophysical Constraints of Foldability.

Whereas modern proteins rely on a quasi-universal repertoire of 20 canonical amino acids (AAs), numerous lines of evidence suggest that ancient proteins relied on a limited alphabet of 10 "early" AAs and that the 10 "late" AAs were products of biosynthetic pathways. However, many nonproteinogenic AAs were also prebiotically available, which begs two fundamental questions: Why do we have the current modern amino acid alphabet and would proteins be able to fold into globular structures as well if different amino acids comprised the genetic code? Here, we experimentally evaluate the solubility and secondary structure propensities of several prebiotically relevant amino acids in the context of synthetic combinatorial 25-mer peptide libraries. The most prebiotically abundant linear aliphatic and basic residues were incorporated along with or in place of other early amino acids to explore these alternative sequence spaces. The results show that foldability was likely a critical factor in the selection of the canonical alphabet. Unbranched aliphatic amino acids were purged from the proteinogenic alphabet despite their high prebiotic abundance because they generate polypeptides that are oversolubilized and have low packing efficiency. Surprisingly, we find that the inclusion of a short-chain basic amino acid also decreases polypeptides' secondary structure potential, for which we suggest a biophysical model. Our results support the view that, despite lacking basic residues, the early canonical alphabet was remarkably adaptive at supporting protein folding and explain why basic residues were only incorporated at a later stage of protein evolution.

New perspectives in architecture through transformable structures: A simulation study

Structures enabling transformability of buildings, components and materials at different levels gain significance in view of a sustainable built environment. Such structures are capable of obtaining different shapes in response to varying functional, environmental or loading conditions. Certain limitations of classic tensegrity and scissor-like structures, applied so far in an architectural and engineering context, are attributed to a limited number of possible configurations and a big number of actuators required. In this context, rigid-bar linkages offer a promising alternative with regard to constructability, modularity, transformability and control components integration. In achieving improved flexibility and controllability with a reduced number of actuation devices, a kinematics principle has been previously proposed by the authors that involves the reduction of the system to an externally controlled one degree-of-freedom mechanism in a multistep transformation process. The paper presents application of the kinematics principle in two classes of a transformable spatial rigid-bar linkage structure. Investigation of the system kinematics was conducted using parametric associative design. The kinematics principle is applied on a torus-shaped spatial structural system composed of planar interconnected linkages. Alternative motion sequences of multiple transformation steps by the planar linkages can be implemented for the stepwise adjustment of the joints to their desired values. The actuators employed are positioned at the ground supports and are detached from the main structural body. Thus, minimum structural self-weight, simplicity and reduced energy consumption become possible. The transformation approaches using parametric associative design are exemplified based on a selected motion sequence pattern. The case study demonstrates the high degree of control flexibility and transformability of the system.

Supramolecular alternating copolymers with highly efficient fluorescence resonance energy transfer.

This article reports alternating supramolecular copolymerization of two naphthalene-diimide (NDI)-derived building blocks (NDI-1 and NDI-2) under thermodynamic control. Both monomers contain a central NDI chromophore, attached to a hydrocarbon-chain and a carboxylic-acid group. The NDI core in NDI-2 is symmetrically substituted with two butane-thiol groups, which makes it distinct from NDI-1. In decane, a 1 : 1 mixture of NDI-1 and NDI-2 shows spontaneous gelation and a typical fibrillar network, unlike the behavior of either of the components individually. The solvent-dependent UV/vis spectrum of the mixed sample in decane shows bathochromically shifted sharp absorption bands and a sharp emission band (holds a mirror-image relationship) with a significantly small Stokes shift compared to those in CHCl3, indicating J-aggregation. In contrast, the aggregated spectra of the individual monomers show broad structureless features, suggesting ill-defined aggregates. Cooling curves derived from the temperature-dependent UV/vis spectroscopy studies revealed early nucleation and a signature of well-defined cooperative polymerization for the mixed sample, unlike either of the individual components. Molecular dynamics simulations predicted the greatest dimer formation tendency for the NDI-1 + NDI-2 (1 : 1), followed by pure NDI-1 and NDI-2. Theoretical studies further revealed a partial positive charge in the NDI ring of NDI-1 when compared to NDI-2, promoting the alternating stacking propensity, which is also favored by the steric factor as NDI-2 is core-substituted with alkyl thiols. Such theoretical predictions fully corroborate with the experimental results showing 1 : 1 stoichiometry (from Job's plot) of the two monomers, indicating alternate stacking sequences in the H-bonded (syn-syn catemer type) supramolecular copolymer. Such alternating supramolecular copolymers showed highly efficient (>93%) fluorescence resonance energy transfer (FRET).

Highly Similar Average Collateral Effect of Synonymous Mutations Across Alternative Reading Frames: A Potential Role In Evolvability

Abstract Synonymous mutations in a protein coding gene lead to a remarkably similar average “collateral” mutation effect size across alternative reading frames (1). Here we quantify the rarity of this feature among possible block structure codes as 0.77%. Then we develop a simple model of evolutionary search with two types of mutation. Across different mutation step sizes and ratios of the two types, the fitness-maximizing region corresponds to using a single average mutation value. The analogous constant average collateral mutation effect observed for the standard genetic code may likewise facilitate evolutionary search in alternative frame sequences.

Structural characterization and electronic properties of Ni/rubrene bilayers with alternative stacking sequences.

Recent progress in organic electronics has attracted interest due to their excellent characteristics that include photovoltaic, light emission, and semiconducting behaviours. Spin-induced properties play important roles in organic electronics, while introducing spin into an organic layer in which spin responses, such as a weak spin-orbital coupling and long spin-relaxation time, allows a variety of spintronic applications to be achieved. However, such spin responses are rapidly attenuated by misalignment in the electronic structure of hybrid structures. We report herein on the energy level diagrams of Ni/rubrene bilayers that can be tuned by an alternating stacking. The band edges of the highest occupied molecular orbital (HOMO) levels were determined to be 1.24 and 0.48 eV relative to the Fermi level for Ni/rubrene/Si and rubrene/Ni/Si bilayers, respectively. This raises a possibility of accumulating electric dipoles at the ferromagnetic/organic semiconductor (FM/OSC) interface, which would inhibit the transfer of spin in the OSC layer. This phenomenon is caused by the formation of a Schottky-like barrier in the rubrene/Ni heterostructures. According to the information about the band edges of the HOMO levels, schematic plots of the HOMO shift in the electronic structure of the bilayers are presented. Based on the lower value of the effective uniaxial anisotropy for Ni/rubrene/Si, the uniaxial anisotropy was suppressed compared to that of rubrene/Ni/Si. The characteristics of the formation of Schottky barriers at the FM/OSC interface have an impact on the temperature-dependent spin states in the bilayers.

On uniform consistency of Neyman’s type nonparametric tests

The goodness-of-fit problem is explored, when the test statistic is a linear combination of squared Fourier coefficients’ estimates coming from the Fourier decomposition of a probability density. Common examples of such statistics include Neyman’s test statistics and test statistics, generated by L2-norms of kernel estimators. We prove the asymptotic normality of the test statistic for both the null and alternative hypothesis. Using these results we deduce conditions of uniform consistency for nonparametric sets of alternatives, which are defined in terms of distribution or density functions. Results on uniform consistency, related to the distribution functions, can be seen as a statement showing to what extent the distance method, based on a given test statistic, makes the hypothesis and alternatives distinguishable. In this case, the deduced conditions of uniform consistency are close to necessary. For sequences of alternatives - defined in terms of density functions - approaching the hypothesis in L2-metric, we find necessary and sufficient conditions for their consistency. This result is obtained in terms of the concept of maxisets, the description of which for given test statistics is found in this publication.

Evaluation of Enhanced 3D Brain Image Using Ultrashort TE Sequence with Inversion Recovery for Preoperative Examination of Brain Tumor: Phantom Study Compared with MPRAGE

It is important to obtain accurate anatomical information with little distortion in preoperative examination of brain tumors. Using PETRA, which is an ultrashort echo time (UTE) sequence that is less affected by magnetic susceptibility artifacts, we determined the optimal imaging conditions (radial views [RV] and inversion time [TI]) for IR-PETRA using the inversion recovery (IR) method and compared it with MPRAGE. IR-PETRA was found to be slightly inferior to MPRAGE in sharpness under the optimum conditions (RV=100,000 and TI=500 ms), but it was significantly improved by using a high RV value, and SNR and CNR were higher than or equal to MPRAGE. It is suggested that IR-PETRA may be an alternative sequence of MPRAGE in preoperative examination of brain tumors.

Customs brokerage company selection problem with hybrid method

Purpose- Customs are the main transit points in cross-border trade activities. Customs logistics activities are carried out by authorized customs brokerage companies (CBC). Export/import companies that execute customs clearance with the right CBC partners gain competitive advantage. Therefore, selecting the right CBC is an important decision-making problem. In this research, CBC selection problem is handled with fuzzy-based multi criteria decision-making (MCDM) methods. Methodology- The research application covers the CBC selection process of an export firm. The criteria for the problem are obtained as a result of the literature review. The opinions of the decision makers are also taken. Seven criteria have been identified. These criteria are cost/price, service quality, information system and technology, flexibility, relationship, professionalism, reputation. Fuzzy-based stepwise weight assessment ratio analysis (F-SWARA) method is used for criterion weighting. In order of alternatives, ranking of alternatives through functional mapping of criterion sub-intervals into single interval (F-RAFSI) method is applied. Four decision makers are used to compare the criteria. Findings- Four CBC alternative rankings based on criteria are made. According to the research findings, the highest criterion weight is determined as service quality. The first alternative is chosen as the best alternative. Conclusion- CBC alternative sequencing has been made for the export company by applying fuzzy-based MCDM methods. Thus, the applicability of MCDM methods is supported in CBC company selection. In addition, the CBC selection criteria are determined, and the CBC selection problem are shed light on. Suggestions are also made to export companies and researchers based on the results of the research.

Qualitative and Quantitative Image Analysis of MRCP Imaging in T2 SS-FSE and T2* FIESTA Fat Saturation

The T2 weighted imaging of coronal MRCP can used a sequence derived from spin echo is the SS-FSE sequence and the gradient echo fast imaging is FIESTA. SS-FSE can be done with the fat saturation technique to suppress the fat signal so that it will be hypointense. The use of the breath-hold technique can also be used in both sequences. This study was to compared the differences in coronal MRCP image information between SS-FSE and FIESTA fat saturation to evaluate their ability to depict the image quality of MRCP. 15 patients performed 2D T2 SS-FSE and FIESTA fat saturation coronal MRCP. The images analyzed by qualitative study that was carried out by MRCP questionnaire which was examined by radiologist. Quantitative analysis was conducted by measuring the signal-to-noise ratio (SNR) values. The result is the FIESTA fat saturation sequence shows better image information and more optimized SNR than the SS-FSE on coronal MRCP because it can reveal more clear and informative anatomy such as common bile duct, pancreatic duct, cystic duct and intrahepatic duct. Finally, FIESTA fat saturation can be used as a effective alternative sequence and can improve billiary system of MRCP image quality

0-1 mathematical programming models for flexible process planning

Flexible Process Planning (FPP) is one of the key intelligent manufacturing techniques. The FPP problem is exactly and concisely formulated using 0-1 mathematical programming. Compared with the existing models, the new formulation simultaneously considers alternative operation selection and sequencing and operational method assignment under two optimization criteria. The new formulation does not need to plot the common AND/OR-network that often depicts partial possible processing routes. Distinctively, the important operational precedence constraint is beforehand transformed into the possible successor set of each operation and the possible immediate successor set. Three methods are creatively proposed to prohibit from generating a cycle in sequencing. The complicated criteria involving the machine, tool and setup changeover identification are linearly expressed. The experimental results indicate that the proposed 0-1 linear programming models are able to quickly obtain the optimal solution of the small-scale problems and stably find a satisfactory solution of the large-scale problems within acceptable time. Compared with the existing mathematical programming models for process planning, the proposed linear models have lower complexity and better performance in solving benchmark instances. In two groups of comparative experiments, the number of constraints of the proposed linear models dramatically reduces by 99.6% and 70%, respectively. Moreover, all benchmark instances are exactly solved by the Cplex solver using the proposed linear models within one hour.

Determination of alternation sequence for additive and subtractive manufacturing based on subtractive manufacturing simulation

Hybrid manufacturing, a combination of subtractive manufacturing (SM) and additive manufacturing (AM), is employed to fabricate complicated shapes and reduce the total process time. The process time of SM, such as the milling process, depends on the cutting tool. A long cutting tool is used for finishing complicated shapes to avoid collisions between the cutting tool and workpiece, but it increases the processing time. However, high-speed cutting conditions can be applied if a short cutting tool is used. However, this requires some alternation between AM and SM. For optimal process planning, the alternation sequence and process time should be estimated in advance. In this study, an SM process simulator and alternation-sequence proportion system was developed. This system can simulate the SM process and propose an alternation sequence while avoiding collisions during the SM process. In addition, the process time can be estimated using the system. Therefore, the system user can plan the hybrid manufacturing process by considering the total process time and alternation sequence. The verification-experiment results confirmed that two patterns of hybrid manufacturing were successfully conducted, and the process time could be estimated with high accuracy using the proposed system.

Mate-pair genome sequencing reveals structural variants for idiopathic male infertility.

Currently, routine genetic investigation for male infertility includes karyotyping analysis and PCR for Y chromosomal microdeletions to provide prognostic information such as sperm retrieval success rate. However, over 85% of male infertility remain idiopathic. We assessed 101 malepatients with primary infertility in a retrospective cohort analysis who have previously received negative results from standard-of-care tests. Mate-pair genome sequencing (large-insert size library), an alternative long-DNA sequencing method, was performed to detect clinically significant structural variants (SVs) and copy-number neutral absence of heterozygosity (AOH). Candidate SVs were filtered against our in-house cohort of 1077 fertile men. Genes disrupted bypotentially clinically significant variants were correlated with single-cellgene expression profiles ofhuman fetal and postnatal testicular developmental lineages and adult germ cells. Follow-up studies were conducted for each patient with clinically relevant finding(s). Molecular diagnoses were madein 11.1% (7/63) of patients with non-obstructive azoospermia and 13.2% (5/38) of patients with severe oligozoospermia. Among them, 12 clinically significant SVs were identified in 12 cases, including five known syndromes, one inversion, and six SVs with direct disruption of genes by intragenic rearrangements or complex insertions. Importantly, a genetic defect related to intracytoplasmic sperm injection (ICSI) failure was identified in a patient withnon-obstructive azoospermia, illustrating the additional value of an etiologic diagnosis in addition to determining sperm retrieval rate. Our study reveals a landscape of various genomic variants in 101 males with idiopathic infertility, not only advancing understanding of the underlying mechanisms of male infertility, but also impacting clinical management.

Full-length transcriptome sequencing and comparative transcriptome analysis of Eriocheir sinensis in response to infection by the microsporidian Hepatospora eriocheir.

As a new generation of high-throughput sequencing technology, PacBio Iso-Seq technology (Iso-Seq) provides a better alternative sequencing method for the acquisition of full-length unigenes. In this study, a total of 22.27 gigabyte (Gb) subread bases and 128,614 non-redundant unigenes (mean length: 2,324 bp) were obtained from six main tissues of Eriocheir sinensis including the heart, nerve, intestine, muscle, gills and hepatopancreas. In addition, 74,732 unigenes were mapped to at least one of the following databases: Non-Redundant Protein Sequence Database (NR), Gene Ontology (GO), Kyoto Encyclopaedia of Genes and Genomes (KEGG), KEGG Orthology (KO) and Protein family (Pfam). In addition, 6696 transcription factors (TFs), 28,458 long non-coding RNAs (lncRNAs) and 94,230 mRNA-miRNA pairs were identified. Hepatospora eriocheir is the primary pathogen of E. sinensis and can cause hepatopancreatic necrosis disease (HPND); the intestine is the main target tissue. Here, we attempted to identify the key genes related to H. eriocheir infection in the intestines of E. sinensis. By combining Iso-Seq and Illumina RNA-seq analysis, we identified a total of 12,708 differentially expressed unigenes (DEUs; 6,696 upregulated and 6,012 downregulated) in the crab intestine following infection with H. eriocheir. Based on the biological analysis of these DEUs, several key processes were identified, including energy metabolism-related pathways, cell apoptosis and innate immune-related pathways. Twelve selected genes from these DEUs were subsequently verified by quantitative real-time PCR (qRT-PCR) analysis. Our findings enhance our understanding of the E. sinensis transcriptome and the specific association between E. sinensis and H. eriocheir infection.

The Long and Short of Genome Sequencing: Using a Hybrid Sequencing Strategy to Sequence Oral Microbial Genomes.

Since our chapter on genome sequencing using the GS-FLX pyrosequencer in the First Edition of this book, significant advances have been made in next-generation DNA sequencing (NGS) technology. Not only has the GS-FLX become extinct, but the more recent introduction and establishment of the so-called third-generation DNA sequencers by Pacific Biosciences (PacBio) and Oxford Nanopore Technologies (ONT) has revolutionized genomics yet again by generating ultra-long (>100,000 basepair) sequence reads concomitant with an incredible reduction in cost per sequenced basepair. Unfortunately, the ultra-high sequence yields of third-generation sequencers are compromised by their inherent sequencing error rates, prompting an alternative sequencing strategy, i.e., a hybrid sequencing strategy, which combines PacBio/ONT primary datasets with complementary datasets generated by mainstream short-read NGS platforms, e.g., Illumina or Ion Torrent. Although the concept of a hybrid sequencing strategy is not new, existing yields and accuracy of ultra-long and short-read sequencing technologies makes such a strategy achievable, resulting in complete genome sequences in one hit. In this chapter, we describe our updated laboratory and bioinformatic protocols that will allow the average research group to obtain complete oral microbial genome sequences assembled from a combination of DNA sequence data generated by NGS and third-generation platforms.

Physical and mechanical properties of kenaf/flax hybrid composites

AbstractThis research investigates the physical and mechanical properties of hybrid composites made of epoxy reinforced by kenaf and flax natural fibers to investigate the hybridization influences of the composites. Pure and hybrid composites were fabricated using bi‐directional kenaf and flax fabrics at different stacking sequences utilizing the vacuum‐assisted resin infusion method. The pure and hybrid composites' physical properties, such as density, fiber volume fraction (FVF), water absorption capacity, and dimensional stability, were measured. The tests of tensile, flexural, interlaminar shear and fracture toughness (Mode II) were examined to determine the mechanical properties. The results revealed that density remained unchanged for the hybrid compared to pure kenaf/epoxy composites. The tensile, flexural, and interlaminar shear performance of flax/epoxy composite is improved by an increment of kenaf FVF in hybrid composites. The stacking sequence significantly affected the mechanical properties of hybrid composites. The highest tensile strength (59.8 MPa) was obtained for FK2 (alternative sequence of flax and kenaf fibers). However, FK3 (flax fiber located on the outer surfaces) had the highest interlaminar shear strength (12.5 MPa) and fracture toughness (3302.3 J/m2) among all tested hybrid composites. The highest water resistance was achieved for FK5 with the lowest thickness swelling.

U-statistic based on overlapping sample spacings

For testing goodness of fit, we consider a class of U-statistics of overlapping spacings of order two, and investigate their asymptotic properties. The standard U-statistic theory is not directly applicable here as the overlapping spacings form a dependent random sequence. The asymptotic distribution of the statistics under the null hypothesis and under a sequence of local alternatives are derived. In terms of the Pitman ARE, the U-statistic based on Gini’s mean square difference of overlapping spacings is found to be the asymptotically locally most powerful. Interestingly, this test has the same efficacy as the Greenwood test based on overlapping spacings.

A new bootstrap assisted test for checking second order stationarity

A new computationally driven method is proposed to check if a possibly nonlinear time series is second order stationary or not, which is important in time series modeling. The new test relies on blocks of blocks bootstrap covariance matrix estimates and Walsh transformations in order to capture the nonlinearity features of time series. The asymptotic normality of the Walsh coefficients and their asymptotic covariance matrix under the null hypothesis are derived for nonlinear processes. In addition, the asymptotic covariance matrix of an increasing dimension is shown to be consistently estimated by a blocks of blocks bootstrap procedure. In the framework of locally stationary nonlinear processes, it is shown that the proposed test is consistent under a sequence of local alternatives. A simulation study is conducted to examine the finite sample performance of the procedure. In many nonlinear time series settings, the proposed test works well while existing methods may have highly inflated type I error rates. The proposed test is applied to an analysis of a financial data set.