118 research outputs found
Simulation of temperature distribution and discharge crater of SiCp/Al composites in a single-pulsed arc discharge
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The impact of the COVID-19 pandemic lockdown on rhegmatogenous retinal detachment services—Experiences from the Tongren eye center in Beijing
Purpose-
To investigate the impact on services for rhegmatogenous retinal detachment (RRD) patients during the COVID-19 (2019coronal virus disease) pandemic in one tertiary center in Beijing.
Methods-
A retrospective cohort study. Two reviewed consecutive RRD patients cohorts of the same length were treated during two different periods: the COVID-19 pandemic and the pre-COVID-19 group. The characteristics of patients, surgery, anesthesia methods, length of hospital stay, and the latest follow-up were recorded and analyzed.
Results-
There were 79 patients in the COVID-19 pandemic group with a 55.9% reduction (179). Compared to patients in the pre-COVID-19, patients in the COVID-19 pandemic had a longer presurgical waiting times (28days, 3days, p<0.001), a higher percentage of patients with presurgical poor (less than 0.02) visual acuity (55.7%, 32.4%, p = 0.009), and a higher percentage of patients with presurgical choroidal detachment (34.2%, 19.6%, p = 0.01). There was no significant difference in the severity of presurgical proliferative vitreoretinopathy between the two groups (p = 0.64). Surgeries on pathological myopia patients with macular hole retinal detachment were postponed in the COVID-19 pandemic. There was a lower percentage of scleral buckling (27.8%, 41.3%, p = 0.02) and a lower rate of subretinal fluid drainage (45.4%, 75.7%, p = 0.01) in the COVID-19 pandemic. There was no significant difference in either postoperative visual acuity (p = 0.73) or the rate of single-surgery retinal attachment (p = 1) between the two groups. Patients in the COVID-19 pandemic had a shorter length of hospital stay (3hours, 35 hours, p<0.001), and a lower percentage of patients received general anesthesia (48.1%, 83.2%, p<0.001). None was infected with COVID-19 disease during the pandemic.
Conclusion-
The COVID-19 pandemic lockdown caused prolonged presurgical waiting times, shorter hospital stays, less general anesthesia, and a significant reduction of RRD surgeries. The RD were more complicated, the surgeons were more conservative on procedures and patients selection, while the surgery outcomes were comparable
Yet another Improvement of Plantard Arithmetic for Faster Kyber on Low-end 32-bit IoT Devices
This paper presents another improved version of Plantard arithmetic that
could speed up Kyber implementations on two low-end 32-bit IoT platforms (ARM
Cortex-M3 and RISC-V) without SIMD extensions. Specifically, we further enlarge
the input range of the Plantard arithmetic without modifying its computation
steps. After tailoring the Plantard arithmetic for Kyber's modulus, we show
that the input range of the Plantard multiplication by a constant is at least
2.45 times larger than the original design in TCHES2022. Then, two optimization
techniques for efficient Plantard arithmetic on Cortex-M3 and RISC-V are
presented. We show that the Plantard arithmetic supersedes both Montgomery and
Barrett arithmetic on low-end 32-bit platforms. With the enlarged input range
and the efficient implementation of the Plantard arithmetic on these platforms,
we propose various optimization strategies for NTT/INTT. We minimize or
entirely eliminate the modular reduction of coefficients in NTT/INTT by taking
advantage of the larger input range of the proposed Plantard arithmetic on
low-end 32-bit platforms. Furthermore, we propose two memory optimization
strategies that reduce 23.50% to 28.31% stack usage for the speed-version Kyber
implementation when compared to its counterpart on Cortex-M4. The proposed
optimizations make the speed-version implementation more feasible on low-end
IoT devices. Thanks to the aforementioned optimizations, our NTT/INTT
implementation shows considerable speedups compared to the state-of-the-art
work. Overall, we demonstrate the applicability of the speed-version Kyber
implementation on memory-constrained IoT platforms and set new speed records
for Kyber on these platforms
CcRR5 interacts with CcRR14 and CcSnRK2s to regulate the root development in citrus
Response regulator (RR) is an important component of the cytokinin (CK) signal transduction system associated with root development and stress resistance in model plants. However, the function of RR gene and the molecular mechanism on regulating the root development in woody plants such as citrus remain unclear. Here, we demonstrate that CcRR5, a member of the type A RR, regulates the morphogenesis of root through interacting with CcRR14 and CcSnRK2s in citrus. CcRR5 is mainly expressed in root tips and young leaves. The activity of CcRR5 promoter triggered by CcRR14 was proved with transient expression assay. Seven SnRK2 family members with highly conserved domains were identified in citrus. Among them, CcSnRK2.3, CcSnRK2.6, CcSnRK2.7, and CcSnRK2.8 can interact with CcRR5 and CcRR14. Phenotypic analysis of CcRR5 overexpressed transgenic citrus plants indicated that the transcription level of CcRR5 was associated with root length and lateral root numbers. This was also correlated to the expression of root-related genes and thus confirmed that CcRR5 is involved in the root development. Taken together, the results of this study indicate that CcRR5 is a positive regulator of root growth and CcRR14 directly regulates the expression of CcRR5. Both CcRR5 and CcRR14 can interact with CcSnRK2s
Improved Plantard Arithmetic for Lattice-based Cryptography
This paper presents an improved Plantard’s modular arithmetic (Plantard arithmetic) tailored for Lattice-Based Cryptography (LBC). Based on the improved Plantard arithmetic, we present faster implementations of two LBC schemes, Kyber and NTTRU, running on Cortex-M4. The intrinsic advantage of Plantard arithmetic is that one multiplication can be saved from the modular multiplication of a constant. However, the original Plantard arithmetic is not very practical in LBC schemes because of the limitation on the unsigned input range. In this paper, we improve the Plantard arithmetic and customize it for the existing LBC schemes with theoretical proof. The improved Plantard arithmetic not only inherits its aforementioned advantage but also accepts signed inputs, produces signed output, and enlarges its input range compared with the original design. Moreover, compared with the state-of-the-art Montgomery arithmetic, the improved Plantard arithmetic has a larger input range and smaller output range, which allows better lazy reduction strategies during the NTT/INTT implementation in current LBC schemes. All these merits make it possible to replace the Montgomery arithmetic with the improved Plantard arithmetic in LBC schemes on some platforms. After applying this novel method to Kyber and NTTRU schemes using 16-bit NTT on Cortex-M4 devices, we show that the proposed design outperforms the known fastest implementation that uses Montgomery and Barrett arithmetic. Specifically, compared with the state-of-the-art Kyber implementation, applying the improved Plantard arithmetic in Kyber results in a speedup of 25.02% and 18.56% for NTT and INTT, respectively. Compared with the reference implementation of NTTRU, our NTT and INTT achieve speedup by 83.21% and 78.64%, respectively. As for the LBC KEM schemes, we set new speed records for Kyber and NTTRU running on Cortex-M4
Mitigating the Alignment Tax of RLHF
LLMs acquire a wide range of abilities during pre-training, but aligning LLMs
under Reinforcement Learning with Human Feedback (RLHF) can lead to forgetting,
which is also known as the alignment tax. To empirically verify this
hypothesis, we conducted experiments with existing RLHF algorithms using
OpenLLaMA-3B, which revealed a pronounced alignment tax in NLP tasks. On the
other hand, despite various techniques to mitigate forgetting, they are often
at odds with the RLHF performance, leading to a trade-off between reward
maximization and forgetting mitigation.
In light of the above pressing issue in aligning LLMs, in this paper we
explore model averaging, which interpolates between pre and post RLHF model
weights, to achieve a more efficient reward-tax Pareto front. To understand its
effectiveness, We offer theoretical insights into model averaging, revealing
that it enhances performance Pareto front by increasing feature diversity on
the layers where tasks share overlapped feature spaces. Empirical evidence
corroborates our analysis by showing the benefits of averaging low-level
transformer layers. Building on the analysis and the observation that averaging
different layers of the transformer leads to significantly different reward-tax
trade-offs, we propose Adaptive Model Averaging (AMA) to adaptively find
various combination ratios of model layers. AMA seeks to maximize the alignment
reward while incurring minimal alignment tax. Moreover, we validate AMA's
performance across a range of RLHF algorithms over OpenLLaMA-3B and further
extend our findings to Mistral-7B.Comment: 28 Page
siAKR1C3@PPA complex nucleic acid nanoparticles inhibit castration-resistant prostate cancer in vitro
IntroductionAKR1C3, as a crucial androgenic enzyme, implicates the androgen biosynthesis and promoting prostate cancer cell growth in vitro. This study provides a new gene therapy strategy for targeting AKR1C3 to treat castration-resistant prostate cancer.MethodssiAKR1C3@PPA is assembled from PEG3500, PAMAM, Aptamer-PSMA, and siRNA for AKR1C3. We analyzed the relationship between AKR1C3 expression and the survival rate of prostate cancer patients based on the GEPIA online database to perform disease-free survival, and found that AKR1C3 may be an important factor leading to poor prognosis in prostate cancer. Considering AKR1C3 as a therapeutic target for castration-resistant prostate cancer, we constructed a complex nucleic acid nanoparticle, siAKR1C3@PPA to investigate the inhibitory effect on castration-resistant prostate cancer.ResultsAptamer-PSMA acts as a target to guide siAKR1C3@PPA into PSMA-positive prostate cancer cells and specifically down regulate AKR1C3. Cyclin D1 was decreased as a result of siAKR1C3@PPA treatment. Changes in Cyclin D1 were consistent with decreased expression of AKR1C3 in LNCaP-AKR1C3 cells and 22RV1 cells. Furthermore, in the LNCaP-AKR1C3 group, 1070 proteins were upregulated and 1015 proteins were downregulated compared to the LNCaP group according to quantitative 4D label-free proteomics. We found 42 proteins involved in cell cycle regulation. In a validated experiment, we demonstrated that PCNP and CINP were up-regulated, and TERF2 and TP53 were down-regulated by western blotting.ConclusionWe concluded that siAKR1C3@PPA may arrest the cell cycle and affect cell proliferation
LRP6 Knockdown Ameliorates Insulin Resistance via Modulation of Autophagy by Regulating GSK3β Signaling in Human LO2 Hepatocytes
Recent studies suggest that autophagy is highly involved in insulin resistance (IR). Inhibition of the PI3K/AKT/mTOR signaling pathway induces autophagy activation. Additionally, depletion of LRP6 has been shown to increase insulin sensitivity but its mechanism is still not clear. We hypothesized that LRP6 contributes to IR by regulating mTOR mediated autophagy through GSK3β in hepatocytes. LO2 hepatocytes were treated with palmitate (PA) and insulin to induced IR. Levels of LRP6 mRNA and protein expression were measured by real time-PCR and western blot analysis. LRP6 knock down was achieved by adenovirus mediated Si-LRP6 expression and its roles in IR, glucose, GSK3β, mTOR signaling, and autophagy were explored. Finally, GSK3β was overexpressed and its involvement in autophagy and IR was examined. We found that PA treatment led to a reduced glucose uptake and IR in hepatocytes, which was accompanied by an upregulation of LRP6 expression. Knocking down of LRP6 enhanced glucose uptake and insulin sensitivity in PA treated cells, probably through increasing GSK3b activity. Overexpression of GSK3b mimicked LRP6 reduction by enhancing autophagy and ameliorating IR. Our study revealed a significant molecular mechanism connecting LRP6 to insulin sensitivity through GSK3β-mTOR mediated autophagy
Boosting with an aerosolized Ad5-nCoV elicited robust immune responses in inactivated COVID-19 vaccines recipients
IntroductionThe SARS-CoV-2 Omicron variant has become the dominant SARS-CoV-2 variant and exhibits immune escape to current COVID-19 vaccines, the further boosting strategies are required.MethodsWe have conducted a non-randomized, open-label and parallel-controlled phase 4 trial to evaluate the magnitude and longevity of immune responses to booster vaccination with intramuscular adenovirus vectored vaccine (Ad5-nCoV), aerosolized Ad5-nCoV, a recombinant protein subunit vaccine (ZF2001) or homologous inactivated vaccine (CoronaVac) in those who received two doses of inactivated COVID-19 vaccines. ResultsThe aerosolized Ad5-nCoV induced the most robust and long-lasting neutralizing activity against Omicron variant and IFNg T-cell response among all the boosters, with a distinct mucosal immune response. SARS-CoV-2-specific mucosal IgA response was substantially generated in subjects boosted with the aerosolized Ad5-nCoV at day 14 post-vaccination. At month 6, participants boosted with the aerosolized Ad5-nCoV had remarkably higher median titer and seroconversion of the Omicron BA.4/5-specific neutralizing antibody than those who received other boosters. DiscussionOur findings suggest that aerosolized Ad5-nCoV may provide an efficient alternative in response to the spread of the Omicron BA.4/5 variant.Clinical trial registrationhttps://www.chictr.org.cn/showproj.html?proj=152729, identifier ChiCTR2200057278
Didactics of grammar in teaching French as a foreign language in China. Towards a methodological eclecticism : The example of the University of Anhui
En Chine, la recherche sur la didactique de la grammaire française est en retard et sur ce thème il n’existe pas un seul ouvrage de référence rédigé par des Chinois ; nous manquons de méthodes efficaces ; nous manquons de professeurs expérimentés. D’où l’idée de notre thèse et la question qui nous intéresse spécifiquement : « Comment enseigner la grammaire française aux étudiants chinois ? ». Pour répondre à cette question, nous avons fait des recherches dans le département de français de la faculté des langues étrangères de l’Université de l’Anhui. Nous proposons trois hypothèses :1. Dans l’enseignement de la grammaire française, il faut selon les objectifs de chaque cours varier les méthodes en appliquant une méthodologie éclectique. 2. À l’Université de l’Anhui il est impossible d’introduire dans l’enseignement de la grammaire du français l’intégralité des concepts d’enseignement du CECR. 3. Pour les étudiants chinois en Langue et littérature françaises de l’Université de l’Anhui, la grammaire déductive est plus efficace que la grammaire inductive.Tout d’abord, il faut signaler que les deux programmes nationaux chinois sont des documents officiels qui donnent des directives sur l’enseignement de la grammaire française. Mais, souples comme le CECR, ils ne préconisent pas l’utilisation d’une méthode précise et conseillent en revanche aux professeurs de tenir compte avant tout des besoins de l’enseignement pour faire leur choix parmi toutes les méthodes existantes. Par ailleurs, nous avons remarqué que, dans les parties grammaticales des deux tests nationaux chinois (le TFS4 et le TFS8), les questions portent plutôt sur les connaissances grammaticales mémorisées au détriment de la compétence grammaticale. Cette manière d’évaluation influence fortement le mode d’enseignement des professeurs et les amène inévitablement sur le chemin de la méthodologie traditionnelle.Nous analysons ensuite un certain nombre de travaux scientifiques traitant de l’enseignement de la grammaire. Dans ce cadre, il s’agit de comparer la grammaire linguistique à la grammaire pédagogique, la grammaire explicite à la grammaire implicite, la grammaire déductive à la grammaire inductive, d’analyser la place de la grammaire dans les différentes méthodologies, d’interpréter l’enseignement de la grammaire française dans la perspective psycholinguistique et neurolinguistique.De plus l’analyse des interviews et des questionnaires que nous avons effectués auprès des étudiants et des professeurs de l’Université de l’Anhui ainsi que l’observation de six cours de grammaire donnés par différents professeurs nous amène à faire les observations suivantes : en milieu universitaire chinois les grammaires explicite et déductive sont dominantes dans l’enseignement du FLE ; la compétence communicative des étudiants chinois est faible ; les connaissances grammaticales qu’ils apprennent en classe ne peuvent pas se transformer en compétence grammaticale leur permettant de parler et d’écrire correctement. Quant aux méthodes de français ou manuels de grammaire utilisés dans les universités chinoises, nous avons constaté que les manuels bilingues rédigés par des Chinois insistent sur l’exhaustivité, les explications grammaticales sont en général détaillées et précises, tandis que dans les manuels monolingues rédigés par des Français, le métalangage utilisé est généralement simple pour faciliter la compréhension des apprenants.Il est à noter enfin qu’en Chine les cultures d’enseignement des professeurs et les cultures d’apprentissage des étudiants sont particulières, chaque professeur enseigne différemment et chaque étudiant apprend différemment. Nous pensons donc qu’il est raisonnable de combiner plusieurs méthodes - en s’inspirant de leurs avantages respectifs et en dépassant leurs inconvénients - et d’appliquer dans l’enseignement de la grammaire française à l’Université de l’Anhui une méthodologie éclectique.In China, the research on the didactics of French grammar is lagging. There exist such problems as the lack of experienced teachers, effective teaching methods, and lack of reference materials written by the Chinese on this subject. Hence, the idea of this thesis specifically tackles the following question “how should Chinese students be taught French grammar?”To answer this question, research has been carried out in the French Department of the School of Foreign Languages of Anhui University. Through this research, three hypotheses are proposed as follows. 1. It is necessary to apply eclectic methodology when teaching French grammar. Methods must be changed timely and appropriately according to different objectives of courses. 2. It is impossible to fully introduce the CECR teaching concepts into the teaching of French grammar in Anhui University.3. For Chinese students majoring French Language and Literature in Anhui University, deductive grammar is more effective than inductive grammar.After having presented our field of research and analyzed practical needs, objectives and particularities of our students majoring French Language and Literature, we enter into the theoretical framework of our work. First of all, it should be noted that two Chinese national programs are designated as official documents and give instructions on the teaching of French grammar. But like the CECR, both of them are quite flexible. They don’t designate teachers to apply certain teaching approaches; instead, teachers are advised to choose freely among all the existing methods according to the practical teaching need.Secondly, results showed that, in the grammatical parts of two Chinese national tests (TFS4 and TFS8), questions are designed to evaluate students’ grammatical knowledge rather than grammatical competence. Such evaluation approach greatly affected teachers’ teaching methods, and inevitably makes them adopt traditional teaching methodology. Thirdly, analysis on a number of scientific works on French grammar teaching was carried out. In this context, several questions merit attention and further analysis, such as comparing linguistic grammar with pedagogical grammar, explicit grammar with implicit grammar, deductive grammar with inductive grammar; analyzing the role of grammar in different methodologies, interpreting the grammar teaching from psycholinguistic and neurolinguistic perspectives.Fourthly, after the detailed analysis of interviews and questionnaires towards students and professors of Anhui University and the observation of six grammar lessons taught by different teachers, we found that the explanatory and deductive methods dominate the teaching of FLE in Chinese universities. Concerning Chinese students, their communicative competence is rather poor, and the grammatical knowledge they learn in class can not be transformed into grammatical competence, allowing them to speak and write correctly.Fifthly, as for French methods or grammar books used in Chinese universities, we found that bilingual textbooks, written by Chinese, focus on completeness and include detailed and precise grammatical explanations, while in monolingual textbooks written by French, the metalanguage used is generally simple to facilitate the comprehension of the learners.Finally, it should be noted that compared with their counterparts in European countries, the teaching culture of Chinese teachers and the learning culture of Chinese students are quite different. Each teacher teaches differently and each student learns differently. We therefore argue that it is reasonable to combine several teaching methods (such as, traditional methodology, communicative approach, action-oriented approach and so forth) with several grammars by making best of their advantages and overcoming their disadvantages, and applying an eclectic methodology in the teaching of French grammar in Anhui University
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