828 research outputs found
A rare novel mutation in TECTA causes autosomal dominant nonsyndromic hearing loss in a Mongolian family
BACKGROUND: The genetic basis of autosomal dominant nonsyndromic hearing loss is complex. Genetic factors are responsible for approximately 50% of cases with congenital hearing loss. However, no previous studies have documented the clinical phenotype and genetic basis of autosomal dominant nonsyndromic hearing loss in Mongolians. METHODS: In this study, we performed exon capture sequencing of a Mongolian family with hereditary hearing loss and identified a novel mutation in TECTA gene, which encodes α -tectorin, a major component of the inner ear extracellular matrix that contacts the specialized sensory hair cells. RESULTS: The novel G → T missense mutation at nucleotide 6016 results in a substitution of amino acid aspartate at 2006 with tyrosine (Asp2006Tyr) in a highly conserved zona pellucida (ZP) domain of α-tectorin. The mutation is not found in control subjects from the same family with normal hearing and a genotype-phenotype correlation is observed. CONCLUSION: A novel missense mutation c.6016 G > T (p.Asp2006Tyr) of TECTA gene is a characteristic TECTA-related mutation which causes autosomal dominant nonsyndromic hearing loss. Our result indicated that mutation in TECTA gene is responsible for the hearing loss in this Mongolian family
Similar operation template attack on RSA-CRT as a case study
A template attack, the most powerful side-channel attack methods, usually first builds the leakage profiles from a controlled profiling device, and then uses these profiles to recover the secret of the target device. It is based on the fact that the profiling device shares similar leakage characteristics with the target device. In this study, we focus on the similar operations in a single device and propose a new variant of the template attack, called the similar operation template attack (SOTA). SOTA builds the models on public variables (e.g., input/output) and recovers the values of the secret variables that leak similar to the public variables. SOTA’s advantage is that it can avoid the requirement of an additional profiling device. In this study, the proposed SOTA method is applied to a straightforward RSA-CRT implementation. Because the leakage is (almost) the same in similar operations, we reduce the security of RSA-CRT to a hidden multiplier problem (HMP) over GF(q), which can be solved byte-wise using our proposed heuristic algorithm. The effectiveness of our proposed method is verified as an entire prime recovery procedure in a practical leakage scenario
CloudFort: Enhancing Robustness of 3D Point Cloud Classification Against Backdoor Attacks via Spatial Partitioning and Ensemble Prediction
The increasing adoption of 3D point cloud data in various applications, such
as autonomous vehicles, robotics, and virtual reality, has brought about
significant advancements in object recognition and scene understanding.
However, this progress is accompanied by new security challenges, particularly
in the form of backdoor attacks. These attacks involve inserting malicious
information into the training data of machine learning models, potentially
compromising the model's behavior. In this paper, we propose CloudFort, a novel
defense mechanism designed to enhance the robustness of 3D point cloud
classifiers against backdoor attacks. CloudFort leverages spatial partitioning
and ensemble prediction techniques to effectively mitigate the impact of
backdoor triggers while preserving the model's performance on clean data. We
evaluate the effectiveness of CloudFort through extensive experiments,
demonstrating its strong resilience against the Point Cloud Backdoor Attack
(PCBA). Our results show that CloudFort significantly enhances the security of
3D point cloud classification models without compromising their accuracy on
benign samples. Furthermore, we explore the limitations of CloudFort and
discuss potential avenues for future research in the field of 3D point cloud
security. The proposed defense mechanism represents a significant step towards
ensuring the trustworthiness and reliability of point-cloud-based systems in
real-world applications
Research on Preference Polyhedron Model Based Evolutionary Multiobjective Optimization Method for Multilink Transmission Mechanism Conceptual Design
To make the optimal design of the multilink transmission mechanism applied in mechanical press, the intelligent optimization techniques are explored in this paper. A preference polyhedron model and new domination relationships evaluation methodology are proposed for the purpose of reaching balance among kinematic performance, dynamic performance, and other performances of the multilink transmission mechanism during the conceptual design phase. Based on the traditional evaluation index of single target of multicriteria design optimization, the robust metrics of the mechanism system and preference metrics of decision-maker are taken into consideration in this preference polyhedron model and reflected by geometrical characteristic of the model. At last, two optimized multilink transmission mechanisms are designed based on the proposed preference polyhedron model with different evolutionary algorithms, and the result verifies the validity of the proposed optimization method
Neural Radiance Field-based Visual Rendering: A Comprehensive Review
In recent years, Neural Radiance Fields (NeRF) has made remarkable progress
in the field of computer vision and graphics, providing strong technical
support for solving key tasks including 3D scene understanding, new perspective
synthesis, human body reconstruction, robotics, and so on, the attention of
academics to this research result is growing. As a revolutionary neural
implicit field representation, NeRF has caused a continuous research boom in
the academic community. Therefore, the purpose of this review is to provide an
in-depth analysis of the research literature on NeRF within the past two years,
to provide a comprehensive academic perspective for budding researchers. In
this paper, the core architecture of NeRF is first elaborated in detail,
followed by a discussion of various improvement strategies for NeRF, and case
studies of NeRF in diverse application scenarios, demonstrating its practical
utility in different domains. In terms of datasets and evaluation metrics, This
paper details the key resources needed for NeRF model training. Finally, this
paper provides a prospective discussion on the future development trends and
potential challenges of NeRF, aiming to provide research inspiration for
researchers in the field and to promote the further development of related
technologies.Comment: 35 pages, 22 figures, 14 tables, 18 formula
Sparse general non-negative matrix factorization based on left semi-tensor product
The dimension reduction of large scale high-dimensional data is a challenging task, especially the dimension reduction of face data and the accuracy increment of face recognition in the large scale face recognition system, which may cause large storage space and long recognition time. In order to further reduce the recognition time and the storage space in the large scale face recognition systems, on the basis of the general non-negative matrix factorization based on left semi-tensor (GNMFL) without dimension matching constraints proposed in our previous work, we propose a sparse GNMFL/L (SGNMFL/L) to decompose a large number of face data sets in the large scale face recognition systems, which makes the decomposed base matrix sparser and suppresses the decomposed coefficient matrix. Therefore, the dimension of the basis matrix and the coefficient matrix can be further reduced. Two sets of experiments are conducted to show the effectiveness of the proposed SGNMFL/L on two databases. The experiments are mainly designed to verify the effects of two hyper-parameters on the sparseness of basis matrix factorized by SGNMFL/L, compare the performance of the conventional NMF, sparse NMF (SNMF), GNMFL, and the proposed SGNMFL/L in terms of storage space and time efficiency, and compare their face recognition accuracies with different noises. Both the theoretical derivation and the experimental results show that the proposed SGNMF/L can effectively save the storage space and reduce the computation time while achieving high recognition accuracy and has strong robustness
Cloning, reassembling and integration of the entire nikkomycin biosynthetic gene cluster into Streptomyces ansochromogenes lead to an improved nikkomycin production
<p>Abstract</p> <p>Background</p> <p>Nikkomycins are a group of peptidyl nucleoside antibiotics produced by <it>Streptomyces ansochromogenes</it>. They are competitive inhibitors of chitin synthase and show potent fungicidal, insecticidal, and acaricidal activities. Nikkomycin X and Z are the main components produced by <it>S. ansochromogenes</it>. Generation of a high-producing strain is crucial to scale up nikkomycins production for further clinical trials.</p> <p>Results</p> <p>To increase the yields of nikkomycins, an additional copy of nikkomycin biosynthetic gene cluster (35 kb) was introduced into nikkomycin producing strain, <it>S. ansochromogenes </it>7100. The gene cluster was first reassembled into an integrative plasmid by Red/ET technology combining with classic cloning methods and then the resulting plasmid(pNIK)was introduced into <it>S. ansochromogenes </it>by conjugal transfer. Introduction of pNIK led to enhanced production of nikkomycins (880 mg L<sup>-1</sup>, 4 -fold nikkomycin X and 210 mg L<sup>-1</sup>, 1.8-fold nikkomycin Z) in the resulting exconjugants comparing with the parent strain (220 mg L<sup>-1 </sup>nikkomycin X and 120 mg L<sup>-1 </sup>nikkomycin Z). The exconjugants are genetically stable in the absence of antibiotic resistance selection pressure.</p> <p>Conclusion</p> <p>A high nikkomycins producing strain (1100 mg L<sup>-1 </sup>nikkomycins) was obtained by introduction of an extra nikkomycin biosynthetic gene cluster into the genome of <it>S. ansochromogenes</it>. The strategies presented here could be applicable to other bacteria to improve the yields of secondary metabolites.</p
Selectively improving nikkomycin Z production by blocking the imidazolone biosynthetic pathway of nikkomycin X and uracil feeding in Streptomyces ansochromogenes
<p>Abstract</p> <p>Background</p> <p>Nikkomycins are a group of peptidyl nucleoside antibiotics and act as potent inhibitors of chitin synthases in fungi and insects. Nikkomycin X and Z are the main components produced by <it>Streptomyces ansochromogenes</it>. Of them, nikkomycin Z is a promising antifungal agent with clinical significance. Since highly structural similarities between nikkomycin Z and X, separation of nikkomycin Z from the culture medium of <it>S. ansochromogenes </it>is difficult. Thus, generating a nikkomycin Z selectively producing strain is vital to scale up the nikkomycin Z yields for clinical trials.</p> <p>Results</p> <p>A nikkomycin Z producing strain (sanPDM) was constructed by blocking the imidazolone biosynthetic pathway of nikkomycin X via genetic manipulation and yielded 300 mg/L nikkomycin Z and abolished the nikkomycin X production. To further increase the yield of nikkomycin Z, the effects of different precursors on its production were investigated. Precursors of nucleoside moiety (uracil or uridine) had a stimulatory effect on nikkomycin Z production while precursors of peptidyl moiety (L-lysine and L-glutamate) had no effect. sanPDM produced the maximum yields of nikkomycin Z (800 mg/L) in the presence of uracil at the concentration of 2 g/L and it was approximately 2.6-fold higher than that of the parent strain.</p> <p>Conclusion</p> <p>A high nikkomycin Z selectively producing was obtained by genetic manipulation combined with precursors feeding. The strategy presented here might be applicable in other bacteria to selectively produce targeted antibiotics.</p
Immunotherapy resistance in non-small-cell lung cancer: From mechanism to clinical strategies
The high primary resistance incidence and unavoidable secondary resistance are the major clinical obstacle to lasting long-term benefits in Non-small-cell lung cancer (NSCLC) patients treated with immunotherapy. The mechanisms of immunotherapy resistance in NSCLC are complex, mainly involving tumor cells and tumor microenvironment (TME) infiltrating immune cells, including TAMs, B cells, NK cells, and T cells. The selection of clinical strategies for NSCLC progression after immunotherapy resistance should depend on the progressive mode. The progression pattern of NSCLC patients after immunotherapy resistance can be divided into oligo-progression and systemic/multiple progression, which should be considered for further treatment selection. In the future, it needs to explore how to optimize the combined therapy and explore strategies to reprogram infiltrating immune cells under various genetic backgrounds of tumor cells and timely reshape TME during antitumor treatments
NUMERICAL SIMULATION OF ICE MILLING LOADS ON PROPELLER BLADE WITH COHESIVE ELEMENT METHOD
In ice-infested waters, propellers of a polar ship are likely to be exposed to ice loads in different scenarios. Propeller milling with ice is one of the most dangerous cases for ice-propeller interaction. In this study, we try to simulate dynamic milling process of ice-propeller and reproduce resulting physical phenomena. Cohesive element method is used to model ice in the simulation. To simulate material properties of ice, an elastoplastic softening constitutive law is developed. Both crushing and fracture failures are included in the ice-propeller milling process. The ice loads in 6 Dofs acting on blades of a propeller are calculated in time domain. The average and standard deviations of simulated dominant ice loads are compared with those from model test. A good agreement is achieved. By varying propeller rotation speed, advance velocity and cutting depth on ice block, the sensitivity study has been carried out. The results show that dominant ice loads are affected much by the three parameters. It is shown that decreasing rotation speed, or increasing advance velocity and cutting depth may lead to higher ice loads. Care should be taken to avoid over-loading on propeller when operating in ice for polar ship
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