当前共找到 1063 篇文献分享,本页显示第 1 - 20 篇。
1.
林海onrush (2024-10-01 00:41):
#paper, https://doi.org/10.1038/s41586-024-08032-5, Addendum: A graph placement methodology for fast chip design, 谷歌Deepmind团队更新了Alpha智能体家族,提出用于芯片领域的AlphaChip,这种基于深度强化学习的芯片设计方法,已经在生成高效芯片布局方面表现出超越人类专家的能力。通过预训练,AlphaChip能够随着解决更多的芯片布局问题而变得更快更强。这种方法已应用于谷歌多代Tensor处理单元(TPU)芯片设计中,并且在减少布线长度和提升性能方面显著超越了人类专家的成果。AlphaChip的方法对AI驱动的芯片设计领域产生了广泛而深刻的影响。Deepmind的Alpha系列,基本每次提出,必登Nature,而且几乎霸榜了Nature的主刊封面,可见实力之强。
2.
庞庞 (2024-09-30 23:49):
#paper https://doi.org/10.1038/s44220-024-00309-y A mega-analysis of functional connectivity and network abnormalities in youth depression 本文使用了迄今为止青少年抑郁症最大的数据集进行了功能连接和网络异常的mega分析,发现异常的脑区主要在hub节点,并且异常的连接和临床症状存在关联。
3.
muton (2024-09-30 23:40):
#paper https://doi.org/10.1038/s41586-024-07973-1 Human hippocampal and entorhinal neurons encode the temporal structure of experience. 从经验中提取出深层的时序结构是学习和记忆的核心,它使我们能够预测接下来可能发生的事情。作者记录了颅内电极个体的单个神经元活动,并发现人类海马和齿状回神经元会逐渐调整其活动,用以编码复杂图像呈现序列的时序结构。这种表征会迅速形成,无需向被试提供具体指令,并且在规则不再存在的情况下仍然存在。此外,从海马-齿状回神经元群体活动的结构与定义序列的结构图非常相似,同时,也反映了即将到来的刺激的概率。最后,学习序列图与个体神经元自发地、压缩时间地重放与其先前经历的图轨迹相对应的活动有关。这些发现表明,海马体和齿状回的神经元整合“什么”和“何时”的信息,以提取人类经历的持久且可预测的时间结构表征。
Abstract:
AbstractExtracting the underlying temporal structure of experience is a fundamental aspect of learning and memory that allows us to predict what is likely to happen next. Current knowledge about the … >>>
AbstractExtracting the underlying temporal structure of experience is a fundamental aspect of learning and memory that allows us to predict what is likely to happen next. Current knowledge about the neural underpinnings of this cognitive process in humans stems from functional neuroimaging research1–5. As these methods lack direct access to the neuronal level, it remains unknown how this process is computed by neurons in the human brain. Here we record from single neurons in individuals who have been implanted with intracranial electrodes for clinical reasons, and show that human hippocampal and entorhinal neurons gradually modify their activity to encode the temporal structure of a complex image presentation sequence. This representation was formed rapidly, without providing specific instructions to the participants, and persisted when the prescribed experience was no longer present. Furthermore, the structure recovered from the population activity of hippocampal–entorhinal neurons closely resembled the structural graph defining the sequence, but at the same time, also reflected the probability of upcoming stimuli. Finally, learning of the sequence graph was related to spontaneous, time-compressed replay of individual neurons’ activity corresponding to previously experienced graph trajectories. These findings demonstrate that neurons in the hippocampus and entorhinal cortex integrate the ‘what’ and ‘when’ information to extract durable and predictive representations of the temporal structure of human experience. <<<
翻译
4.
白鸟 (2024-09-30 23:10):
#paper doi.org/10.1101/2023.06.30.547258, Mitigating autocorrelation during spatially resolved transcriptomics data analysis. 此文为预刊文章,作者提出了一种空间整合 (SPIN)方法。我们在空间分析时,通常想识别组织中具有相似分子特征的区域或生态位。 对组织特异性邻域进行聚类,产生解剖学上的 "组织区域“。大多数的方法是平滑组织的基因表达特征,把每个细胞的特征向量用自身及其空间近邻的加权和表示。平滑会增加相邻细胞间的自相关性,导致区域划分的模糊性。SPIN方法在平滑之前对每个细胞的空间邻域进行随机抽样,可降低空间自相关性 ,将细胞自身的表达谱与邻近细胞的表达谱进行差异放大,同时仍能捕捉到它们的总体分子组成,"组织区域“的识别更为真实。
Abstract:
AbstractSeveral computational methods have recently been developed for characterizing molecular tissue regions in spatially resolved transcriptomics (SRT) data. However, each method fundamentally relies on spatially smoothing transcriptomic features across neighboring … >>>
AbstractSeveral computational methods have recently been developed for characterizing molecular tissue regions in spatially resolved transcriptomics (SRT) data. However, each method fundamentally relies on spatially smoothing transcriptomic features across neighboring cells. Here, we demonstrate that smoothing increases autocorrelation between neighboring cells, causing latent space to encode physical adjacency rather than spatial transcriptomic patterns. We find that randomly sub-sampling neighbors before smoothing mitigates autocorrelation, improving the performance of existing methods and further enabling a simpler, more efficient approach that we callspatialintegration (SPIN). SPIN leverages the conventional single-cell toolkit, yielding spatial analogies to each tool: clustering identifies molecular tissue regions; differentially expressed gene analysis calculates region marker genes; trajectory inference reveals continuous, molecularly defined ana tomical axes; and integration allows joint analysis across multiple SRT datasets, regardless of tissue morphology, spatial resolution, or experimental technology. We apply SPIN to SRT datasets from mouse and marmoset brains to calculate shared and species-specific region marker genes as well as a molecularly defined neocortical depth axis along which several genes and cell types differ across species. <<<
翻译
5.
尹志 (2024-09-30 23:02):
#paper https://doi.org/10.48550/arXiv.2405.20328 mRNA secondary structure prediction using utility-scale quantum computers。 这是今年IBM和Moderna合作的一篇工作。作者用CVaR-based VQE算法对mRNA的二级结构做了预测。RNA由于其单链多变的特性,非常难以预测。当然也正是这个原因,在计算上很容易被归类到组合优化问题的范畴。因此利用量子计算机去设计特定算法来加速解决,并给出最优结构显得顺理成章。文章使用了IBM的量子处理器Eagle和Heron, 得出的结果和经典算法CPLEX保持一致。当然,考虑到使用了NISQ的方式,如何保证机器的校准及错误抑制文章并没有交代的很细致,默认Eagle和Heron已经做到了吧。当然,这也给VQC算法(包括VQE、QAOA)解决组合优化问题做了一个很好的示范,充分证明了变分算法的灵活性。
arXiv, 2024-05-30T17:58:17Z. DOI: 10.48550/arXiv.2405.20328
Abstract:
Recent advancements in quantum computing have opened new avenues for tacklinglong-standing complex combinatorial optimization problems that are intractablefor classical computers. Predicting secondary structure of mRNA is one suchnotoriously difficult problem … >>>
Recent advancements in quantum computing have opened new avenues for tacklinglong-standing complex combinatorial optimization problems that are intractablefor classical computers. Predicting secondary structure of mRNA is one suchnotoriously difficult problem that can benefit from the ever-increasingmaturity of quantum computing technology. Accurate prediction of mRNA secondarystructure is critical in designing RNA-based therapeutics as it dictatesvarious steps of an mRNA life cycle, including transcription, translation, anddecay. The current generation of quantum computers have reached utility-scale,allowing us to explore relatively large problem sizes. In this paper, weexamine the feasibility of solving mRNA secondary structures on a quantumcomputer with sequence length up to 60 nucleotides representing problems in thequbit range of 10 to 80. We use Conditional Value at Risk (CVaR)-based VQEalgorithm to solve the optimization problems, originating from the mRNAstructure prediction problem, on the IBM Eagle and Heron quantum processors. Toour encouragement, even with ``minimal'' error mitigation and fixed-depthcircuits, our hardware runs yield accurate predictions of minimum free energy(MFE) structures that match the results of the classical solver CPLEX. Ourresults provide sufficient evidence for the viability of solving mRNA structureprediction problems on a quantum computer and motivate continued research inthis direction. <<<
翻译
6.
盼盼 (2024-09-30 22:36):
#paper doi: 10.1002/mds.29430 Application value of serum neurofilament light protein for disease staging in Huntington's disease. 该研究收集了大规模HTT突变携带者生物样本,纳入了症前个体和疾病早中晚期的HD患者以及大片段CAG重复片段携带者,详细阐述了血清神经丝轻链(sNfL)在HD疾病发展过程中的变化轨迹,并利用7.0T磁共振和统一亨廷顿评定量表探究了sNfL与疾病严重程度的关系。结果表明,虽然sNfL浓度在HD发病阶段趋于稳定,但sNfL可精准预测HD发病年龄。此外,sNfL的浓度与认知下降及大脑萎缩呈负相关,且受到年龄和三联核苷酸CAG复制频次的影响。
Abstract:
AbstractBackgroundNeurofilament light protein (NfL) has been proven to be a sensitive biomarker for Huntington's disease (HD). However, these studies did not include HD patients at advanced stages or with larger … >>>
AbstractBackgroundNeurofilament light protein (NfL) has been proven to be a sensitive biomarker for Huntington's disease (HD). However, these studies did not include HD patients at advanced stages or with larger CAG repeats (>50), leading to a knowledge gap of the characteristics of NfL.MethodsSerum NfL (sNfL) levels were quantified using an ultrasensitive immunoassay. Participants were assessed by clinical scales and 7.0 T magnetic resonance imaging. Longitudinal samples and clinical data were obtained.ResultsBaseline samples were available from 110 controls, 90 premanifest HD (pre‐HD) and 137 HD individuals. We found levels of sNfL significantly increased in HD compared to pre‐HD and controls (both P < 0.0001). The increase rates of sNfL were differed by CAG repeat lengths. However, there was no difference in sNfL levels in manifest HD from early to late stages. In addition, sNfL levels were associated with cognitive measures in pre‐HD and manifest HD group, respectively. The increased levels of sNfL were also closely related to microstructural changes in white matter. In the longitudinal analysis, baseline sNfL did not correlate with subsequent clinical function decline. Random forest analysis revealed that sNfL had good power for predicting disease onset.ConclusionsAlthough sNfL levels are independent of disease stages in manifest HD, it is still an optimal indicator for predicting disease onset and has potential use as a surrogate biomarker of treatment effect in clinical trials. © 2023 International Parkinson and Movement Disorder Society. <<<
翻译
7.
符毓 Yu (2024-09-30 18:24):
#paper doi.org/10.3390/en16041594 Euspen, 2023, A comprehensive review on the application of 3D-printed ferromagnetic parts in electric machines。通过在电机设计领域引入增材制造技术,电机的设计灵活性显著提高。本文旨在全面回顾目前如何利用这种扩展的设计自由度。其中许多已经成功打印出来并通过了实验验证。在其他情况下,实验验证不足或结果有限。本文的第二部分简要介绍了印刷铁磁材料应用的两个缺点,即较差的磁性能和单一材料打印的涡流损耗缓解复杂。但是,尽管铁磁材料增材制造技术及其应用尚未完全成熟和发展,但值得期待。
Abstract:
This paper presents a prototype of a low-cost two-phase axial-gap transverse flux generator, in which the magnetic and electric circuits have been made of reused materials, and the stator housing … >>>
This paper presents a prototype of a low-cost two-phase axial-gap transverse flux generator, in which the magnetic and electric circuits have been made of reused materials, and the stator housing has been manufactured by 3D printing of plastic. Therefore, this work presents as a novelty the combination of the novel transverse flux topology and two challenging trends in electrical machines manufacturing, such as reusing of components and additive manufacturing. Axial-gap transverse flux machines potentially enable the combination of two of the main advantages of axial flux machines and transverse flux machines, i.e., short axial length and a high number of poles. The two-phase arrangement with shared air gap is of great interest in order to reduce further the axial length while avoiding the use of magnetic materials in the rotor, such as iron or soft magnetic composites. However, the equivalent air gap might be large, with significant leakage and fringing effects as the magnetic flux closes through the air. Therefore, in this paper the accuracy of the analytical equations and the magnetic equivalent circuit is firstly investigated. The two-phase axial-gap transverse flux machine is prone to misalignment between phases and rotor imbalances that alter the air gap length, so these effects have been included in the simulations with the finite element method. Experimental tests have been conducted throughout the investigation, from the prototype characterization to the steady-state operation, both with no load and with resistive loads. <<<
翻译
8.
哪有情可长 (2024-09-30 17:09):
#paper An ethylene biosynthesis enzyme controls quantitative variation in maize ear length and kernel yield, Nature Communications, 05 October 2021, DOI:10.1038/s41467-021-26123-z. 玉米穗的大小和粒数在不同品种间有所差异,然而关于穗长及其对粒数影响的分子基础所知甚少。玉米雌穗授粉后,由花序分生组织(IM)衍生的小穗分生组织(SMs)发育成籽粒,因此,IM的生长发育决定了玉米花序上的小穗和籽粒的数量。作者鉴定出一个qEL7的数量性状位点,该位点控制穗长、籽粒数目和育性,利用NIL群体发现qEL7SL17和qEL7Ye478在穗长、花期、行粒数、百粒重、穗重之间存在显著的差异。后续对SMs统计发现qEL7Ye478 长穗 NIL 品种中的小花败育率(~18.7%)显著低于 qEL7SL17 短穗 NIL 品种中的小花败育率(~44.7%)。这些结果表明,长穗 qEL7Ye478 中玉米粒的增多是由于发育成种子的小花比例更高,而不是由于小花产量增加。利用精细定位确定一个Zm0001d020686的基因为候选基因,该基因编码 1-氨基环丙烷-1-羧酸氧化酶 2 (ACO2),称之为 ZmACO2。对来自 QTL 亲本的 ZmACO2 进行测序,发现其 5ʹ-非翻译区 (UTR) 和启动子区中有 5 个插入/缺失 (InDels) 和 11 个单核苷酸多态性 (SNP),但编码区中的序列完全相同 。与非编码区域的这些差异一致,ZmACO2 在发育中的穗中的表达在亲本系中存在差异,长穗 qEL7Ye478 系中的表达低于短穗 qEL7SL17 系 (P < 0.01) 。这些结果表明启动子中的序列变异导致 qEL7Ye478 和 qEL7SL17 之间 ZmACO2 表达和穗表型的差异。该基因在乙烯生物合成的最后一步起作用,并特定表达于发育中的花序域中。通过编辑ZmACO2基因确认qEL7,导致发育中穗的乙烯产量减少,并促进分生组织和花朵发展,结果使得杂交种每穗谷物产量增加了约13.4%。最后作者提出,乙烯是花序发展中的关键信号,影响小穗数量、花的育性、穗长和粒数,并且还提供了一种通过优化玉米或其他谷物中的乙烯水平来提高谷物生产力的工具。
Abstract:
AbstractMaize ear size and kernel number differ among lines, however, little is known about the molecular basis of ear length and its impact on kernel number. Here, we characterize a … >>>
AbstractMaize ear size and kernel number differ among lines, however, little is known about the molecular basis of ear length and its impact on kernel number. Here, we characterize a quantitative trait locus, qEL7, to identify a maize gene controlling ear length, flower number and fertility. qEL7 encodes 1-aminocyclopropane-1- carboxylate oxidase2 (ACO2), a gene that functions in the final step of ethylene biosynthesis and is expressed in specific domains in developing inflorescences. Confirmation of qEL7 by gene editing of ZmACO2 leads to a reduction in ethylene production in developing ears, and promotes meristem and flower development, resulting in a ~13.4% increase in grain yield per ear in hybrids lines. Our findings suggest that ethylene serves as a key signal in inflorescence development, affecting spikelet number, floral fertility, ear length and kernel number, and also provide a tool to improve grain productivity by optimizing ethylene levels in maize or in other cereals. <<<
翻译
9.
张浩彬 (2024-09-30 17:03):
#paper DOI 10.48550/arXiv.1902.00751 Parameter-Efficient Transfer Learning for NLP 。ICML 2019 Google 提出了Adapter,这算是peft方法中的开篇文章了。最近在整理大模型的peft的经典文章准备给学生上课,这篇作为开篇最为合适。 微调大型预训练模型是NLP中有效的迁移机制。然而,在存在许多下游任务的情况下,微调在参数效率方面不佳:每个任务都需要一个全新的模型。作为替代方案,我们提出了使用适配器模块进行迁移。适配器模块产生紧凑且可扩展的模型;它们只为每个任务添加少量可训练参数,并且可以在不重新访问之前任务的情况下添加新任务。原始网络的参数保持固定,从而产生高度的参数共享。为了证明适配器的有效性,我们将最近提出的BERT Transformer模型迁移到26个不同的文本分类任务,包括GLUE基准测试。适配器达到了接近最先进的性能,同时每个任务只添加少量参数。在GLUE上,我们达到了完全微调性能的0.4%以内,每个任务只增加3.6%的参数。相比之下,微调每个任务训练100%的参数。 论文中提出了以往的领域适应方法,我们都需要单独对模型进行训练,一般来说包括了两种办法,分别是基于特征的迁移和微调。基于特征的迁移就是基于预训练的embedding模型进行作为特征输入,然后输入到特定的下游任务模型中。
arXiv, 2019-02-02T16:29:47Z. DOI: 10.48550/arXiv.1902.00751
Abstract:
Fine-tuning large pre-trained models is an effective transfer mechanism inNLP. However, in the presence of many downstream tasks, fine-tuning isparameter inefficient: an entire new model is required for every task. … >>>
Fine-tuning large pre-trained models is an effective transfer mechanism inNLP. However, in the presence of many downstream tasks, fine-tuning isparameter inefficient: an entire new model is required for every task. As analternative, we propose transfer with adapter modules. Adapter modules yield acompact and extensible model; they add only a few trainable parameters pertask, and new tasks can be added without revisiting previous ones. Theparameters of the original network remain fixed, yielding a high degree ofparameter sharing. To demonstrate adapter's effectiveness, we transfer therecently proposed BERT Transformer model to 26 diverse text classificationtasks, including the GLUE benchmark. Adapters attain near state-of-the-artperformance, whilst adding only a few parameters per task. On GLUE, we attainwithin 0.4% of the performance of full fine-tuning, adding only 3.6% parametersper task. By contrast, fine-tuning trains 100% of the parameters per task. <<<
翻译
10.
前进 (2024-09-30 16:31):
#paper DOI 10.1186/1471-2105-12-451 Frazer Meacham, Dario Boffelli, Joseph , Identification and correction of systematic error in high-throughput sequence data 这篇论文主要研究了高通量测序数据中系统性错误的问题。系统性错误是指在基因组(或转录组)特定位置的测序读段中,以统计上不太可能的方式累积出现的错误。作者们通过使用高覆盖率数据中的重叠配对读段来表征和描述系统性错误,发现这类错误大约每1000个碱基对中发生一次,并且在不同实验中高度可复制。他们识别了在系统性错误位点频繁出现的序列,并设计了一个分类器,用于区分杂合位点和系统性错误。这个分类器可以用于处理杂合位点等位基因频率不一定为0.5的实验数据,并且可以用于单端数据集。论文的结论是,系统性错误可能很容易被误认为是个体中的杂合位点,或者是群体分析中的SNPs。作者们通过系统性错误的特征描述,开发了一个名为SysCall的程序,用于识别和纠正这类错误,并得出结论认为,在设计和解释高通量测序实验时,考虑纠正系统性错误是很重要的。
Abstract:
Abstract Background A feature common to all DNA sequencing technologies is the presence of base-call errors in the sequenced reads. The implications of such errors are application specific, ranging from … >>>
Abstract Background A feature common to all DNA sequencing technologies is the presence of base-call errors in the sequenced reads. The implications of such errors are application specific, ranging from minor informatics nuisances to major problems affecting biological inferences. Recently developed "next-gen" sequencing technologies have greatly reduced the cost of sequencing, but have been shown to be more error prone than previous technologies. Both position specific (depending on the location in the read) and sequence specific (depending on the sequence in the read) errors have been identified in Illumina and Life Technology sequencing platforms. We describe a new type of systematic error that manifests as statistically unlikely accumulations of errors at specific genome (or transcriptome) locations. Results We characterize and describe systematic errors using overlapping paired reads from high-coverage data. We show that such errors occur in approximately 1 in 1000 base pairs, and that they are highly replicable across experiments. We identify motifs that are frequent at systematic error sites, and describe a classifier that distinguishes heterozygous sites from systematic error. Our classifier is designed to accommodate data from experiments in which the allele frequencies at heterozygous sites are not necessarily 0.5 (such as in the case of RNA-Seq), and can be used with single-end datasets. Conclusions Systematic errors can easily be mistaken for heterozygous sites in individuals, or for SNPs in population analyses. Systematic errors are particularly problematic in low coverage experiments, or in estimates of allele-specific expression from RNA-Seq data. Our characterization of systematic error has allowed us to develop a program, called SysCall, for identifying and correcting such errors. We conclude that correction of systematic errors is important to consider in the design and interpretation of high-throughput sequencing experiments. <<<
翻译
11.
徐炳祥 (2024-09-30 14:55):
#paper doi: 10.1038/s42003-024-06904-0 Communications Biology, 2024, Crosslinking intensity modulates the reliability and sensitivity of chromatin conformation detection at different structural levels。甲醛(FA)是生物化学分析中常用的交联剂,用以固定生物大分子间的相互作用,其效果受反应条件的直接影响。然而对这些影响的定量分析尚十分不足。本文以染色质构象捕获技术为模型,系统性的探讨了甲醛浓度和反应体系温度两个重要参数对甲醛交联过程的影响。结果显示,甲醛的交联效率随浓度和反应温度的提升而提升,交联效率显著影响了所有已知染色质构象层次的检测。随着他们的升高,实验结果的灵敏度和可信度提高,稳定性降低。这些效果可以被一个简单的反应扩散模型解释。本文对解释三维基因组学中普遍存在的矛盾结果,和后续表观组学新技术的开发均有一定指导意义。
12.
钟鸣 (2024-09-29 15:36):
#paper doi:10.1016/j.tics.2021.02.007 The Psychology of Fake News 人们为什么会相信假新闻(谣言)?作者以美国人为主要对象在这里做了简要回顾。读者的政治立场并不会影响到其轻信谣言的可能性,这与此前的认识是不同的。然而,对谣言的熟悉度、权威/精英发布或转载的谣言、点赞量多的谣言、以及能引起读者强烈情绪反应的谣言,更容易被轻信。这些原因似乎指向一个共同的现象就是读者被骗时是处于一种很自然的无意识状态,没有对信息真实性做真假判断。对此,也有一些有效的对策可减轻谣言的传播:媒体识别并限流谣言(风险是错误识别造成的不合理审查);为谣言内容附上警告;对读者进行简明扼要的识别谣言的教育,如“12个技巧列表”;使用众裁代替专业人员识别和鉴定谣言;
13.
zhujie (2024-09-29 12:48):
#paper doi.org:10.1038/s41586-024-07970-4, Nature, 2024, Intragenic DNA inversions expand bacterial coding capacity. 源自单个细菌的细菌种群并非严格意义上的克隆,通常包含具有不同表型的亚群。细菌可以通过相位变异产生异质性——这是一种预先编程的可逆机制,可改变整个种群的基因表达水平。一种研究充分的相位变异类型涉及酶介导的基因组 DNA 特定区域的倒位。通常,这些 DNA 倒位会改变启动子的方向,从而打开或关闭相邻编码区域的转录。通过这种机制,倒位可以影响适应性、生存或群体动态。在这里,Bhatt 实验室开发了 PhaVa,这是一种使用长读长数据集识别 DNA 倒位的计算工具。研究者们还在细菌和古细菌分离株的基因组中鉴定了 372 个“基因内倒位”,这是一类完全在基因内发现的新型 DNA 倒位。基因内倒位允许基因通过翻转编码区内的 DNA 序列来编码两个或更多版本的蛋白质,从而在不增加基因组大小的情况下增加编码能力。 研究者们也验证了肠道共生菌 Bacteroides thetaiotaomicron 中的十种基因内转化子,并通过实验表征了硫胺素生物合成基因 thiC 中的基因内转化子。 推荐这篇研究的理由是研究者们第一次报道了基因内倒位现象,提升了我们对微生物基因组编码潜力的认知。同时,研究者们通过计算工具系统性的鉴定出372个基因内倒位。这些基因内倒位的遗传学机制还有待探索,并且让我们意识到从头基因预测工具有待提高。
14.
小年 (2024-09-29 08:53):
#paper doi: 10.1177/20416695241258748 Perceptual ripening of oranges, i-Perception, 2024, Karl R. Gegenfurtner https://journals.sagepub.com/doi/10.1177/20416695241258748 挺有意思的文章,但感觉有点水,讲了Karl Gegenfurtner买橙子被骗,看起来成熟且颜色鲜艳的橙子从橙色网中拿出来以后橙子变成了绿色,然后研究发现是颜色同化现象导致的,于是发了篇文章讲了下颜色同化现象的研究历史和一些例子以及一些原理。 文章讲的比较浅自己查了下关于颜色同化现象相关的原理,有三个方面的因素:视觉神经机制因素、认知与心理因素、光学与物理因素。个人感觉视觉神经机制因素应该是影响最大的,主要是神经的侧抑制:相邻的神经元之间存在相互抑制的关系,当一个神经元被激活时,它会抑制周围相邻神经元的活动。在颜色感知中,侧抑制机制可以增强颜色边界的对比度,同时也可能影响颜色在空间上的扩散和同化。例如,在一个颜色区域周围,如果存在与之不同的颜色,侧抑制可能会使边界更加清晰,但在某些情况下,也可能导致颜色在一定程度上向相邻区域扩散或同化,使得边界附近的颜色感知发生变化,从而导致颜色同化现象。挺有意思的一个对日常生活现象解释的知识。
Abstract:
We present a practical example for the phenomenon of color assimilation. We describe the advances in research on color assimilation from von Bezold, to Albers and Munker, and provide a … >>>
We present a practical example for the phenomenon of color assimilation. We describe the advances in research on color assimilation from von Bezold, to Albers and Munker, and provide a compelling example of the recently described “Confetti-illusion” by Novick. Our research introduces a novel aspect by showing how unripe and greenish looking oranges can be perceived as ripe and vibrantly colored when viewed through an orange net. These findings highlight the significant implications of color assimilation in everyday consumer environments, offering a fresh perspective on how visual perception can be manipulated. <<<
翻译
15.
颜林林 (2024-09-28 00:05):
#paper doi:10.1126/science.1255905, Science, 2015, Correlated gene expression supports synchronous activity in brain networks. 最近我参与到一项脑科学相关的课题中,于是,开始深入挖挖一些历史上的重要相关文献。这篇应该是第一次将fMRI(功能核磁共振)数据与转录组数据联系起来的文章。作者们先使用静息态 fMRI 数据,使用独立成分分析(Independent Component Analysis, ICA)方法,构建出14个功能网络,通过其 MNI 坐标,映射到来自 Allen Institute 提供的上千个转录组样本数据,确定每个样本所属功能网络。之后,通过置换检验验证了功能网络内基因表达的显著性。采用稳定性选择方法筛选出 136 个关键基因,这些基因与离子通道和突触功能相关,并在阿尔茨海默病和精神分裂症中具有显著作用。之后在青少年 IMAGEN 数据集、小鼠数据集、其他啮齿类研究以及疾病关联分析上验证了基因表达与功能网络的关系,并在不同物种和细胞类型中证实了这些基因的稳定作用。该研究首次在分子层面揭示了基因表达与大脑功能网络的关系。
Science, 2015-6-12. DOI: 10.1126/science.1255905
Jonas Richiardi, Andre Altmann, Anna-Clare Milazzo, Catie Chang, M. Mallar Chakravarty, Tobias Banaschewski, Gareth J. Barker, Arun L.W. Bokde, Uli Bromberg, Christian Büchel, Patricia Conrod, Mira Fauth-Bühler, Herta Flor, Vincent Frouin, Jürgen Gallinat, Hugh Garavan, Penny Gowland, Andreas Heinz, Hervé Lemaître, Karl F. Mann, Jean-Luc Martinot, Frauke Nees, Tomáš Paus, Zdenka Pausova, Marcella Rietschel, Trevor W. Robbins, Michael N. Smolka, Rainer Spanagel, Andreas Ströhle, Gunter Schumann, Mike Hawrylycz, Jean-Baptiste Poline, Michael D. Greicius, , Lisa Albrecht, Chris Andrew, Mercedes Arroyo, Eric Artiges, Semiha Aydin, Christine Bach, Tobias Banaschewski, Alexis Barbot, Gareth Barker, Nathalie Boddaert, Arun Bokde, Zuleima Bricaud, Uli Bromberg, Ruediger Bruehl, Christian Büchel, Arnaud Cachia, Anna Cattrell, Patricia Conrod, Patrick Constant, Jeffrey Dalley, Benjamin Decideur, Sylvane Desrivieres, Tahmine Fadai, Herta Flor, Vincent Frouin, Jürgen Gallinat, Hugh Garavan, Fanny Gollier Briand, Penny Gowland, Bert Heinrichs, Andreas Heinz, Nadja Heym, Thomas Hübner, James Ireland, Bernd Ittermann, Tianye Jia, Mark Lathrop, Dirk Lanzerath, Claire Lawrence, Hervé Lemaitre, Katharina Lüdemann, Christine Macare, Catherine Mallik, Jean-François Mangin, Karl Mann, Jean- Luc Martinot, Eva Mennigen, Fabiana Mesquita de Carvahlo, Xavier Mignon, Ruben Miranda, Kathrin Müller, Frauke Nees, Charlotte Nymberg, Marie-Laure Paillere, Tomas Paus, Zdenka Pausova, Jean-Baptiste Poline, Luise Poustka, Michael Rapp, Gabriel Robert, Jan Reuter, Marcella Rietschel, Stephan Ripke, Trevor Robbins, Sarah Rodehacke, John Rogers, Alexander Romanowski, Barbara Ruggeri, Christine Schmäl, Dirk Schmidt, Sophia Schneider, MarkGunter Schumann, Florian Schubert, Yannick Schwartz, Michael Smolka, Wolfgang Sommer, Rainer Spanagel, Claudia Speiser, Tade Spranger, Alicia Stedman, Sabina Steiner, Dai Stephens, Nicole Strache, Andreas Ströhle, Maren Struve, Naresh Subramaniam, Lauren Topper, Robert Whelan, Steve Williams, Juliana Yacubian, Monica Zilbovicius, C Peng Wong, Steven Lubbe, Lourdes Martinez-Medina, Alinda Fernandes, Amir Tahmasebi <<<
Abstract:
Cooperating brain regions express similar genesWhen the brain is at rest, a number of distinct areas are functionally connected. They tend to be organized in networks. Richiardiet al.compared brain imaging … >>>
Cooperating brain regions express similar genesWhen the brain is at rest, a number of distinct areas are functionally connected. They tend to be organized in networks. Richiardiet al.compared brain imaging and gene expression data to build computational models of these networks. These functional networks are underpinned by the correlated expression of a core set of 161 genes. In this set, genes coding for ion channels and other synaptic functions such as neurotransmitter release dominate.Science, this issue p.1241 <<<
翻译
16.
李翛然 (2024-09-27 21:35):
#paper doi:10.13345/j.cjb.220582 《工程菌种自动化高通量编辑与筛选研究进展》该论文主要讨论了合成生物学领域中工程菌种的自动化高通量编辑与筛选技术的研究进展。合成生物学通过标准化和模块化生物实验对象、方法、技术和流程,创建自动化与高通量的合成生物铸造模式。 这种模式结合了复杂生物过程与自动化设施,颠覆了传统的劳动密集型研究方式,提高了技术迭代能力,促进了合成生物学的发展和产业化应用。 研究进展: 自动化基因编辑: 论文回顾了天津工业生物技术研究所在自动化高通量编辑与筛选领域的工作进展。 讨论了基因克隆、基因组编辑、编辑序列设计的自动化实现。 介绍了CRISPR/Cas9系统等基因编辑技术在自动化操作中的应用。 高通量筛选技术: 论文分析了流式细胞、液滴微流控、全基因组规模扰动测序等高通量筛选技术。 讨论了这些技术在筛选工程菌株中的应用和效果。 最近在读博,高级制药工程需要读中文论文…………
17.
半面阳光 (2024-09-25 15:13):
#paper DOI: https://doi.org/10.1038/s41436-019-0634-7, Genetics in Medicine, 2020, Low-pass genome sequencing versus chromosomal microarray analysis: implementation in prenatal diagnosis. 这篇文章比较了 low-pass genome sequencing (GS)与chromosomal microarray analysis (CMA)两种方法在染色体异常的产前检测中的表现。征集了1023个产前诊断的样本,同时进行了低深度WGS和CMA来检测CNVs. 分析结果显示,低深度的WGS检测出124例的染色体数目异常和致病(p)或可能致病(lp)CNVs121例,同时还检测出17例其他临床相关的p/lpCNVs. 低深度WGS检测显著降低了需要进一步进行CMA检测的重复检测率(4.6%,47/1023),并且其所需DNA样本量更低(50ng)。文章认为,与CMA相比而言,低深度的WGS能够提供共临床有效信息,并且提升了检测的分辨率,增强了检测出嵌合性(mosaicism)异常的敏感性。这篇文献为低深度的WGS用于产前检测CNVs提供了证据支持。
18.
龙海晨 (2024-09-19 12:12):
#paper Zhu Q, Wan NB, Deng HW, Lu LL, Zhang Y, He X, Liu H, He Y. SEC14L3 plays a tumor-suppressive role in breast cancer through a Wnt/β-catenin-related way. Exp Cell Res. 2022 Aug 1;417(1):113161. doi: 10.1016/j.yexcr.2022.113161. Epub 2022 Apr 18. PMID: 35447102.这是一篇生物信息与分子生物学细胞生物学实验相结合的文章。文章先对TCGA-BRCA数据集进行挖掘,发现IL1F6、MRGPRX1、SEC14L3与乳腺癌患者总生存期显著相关。SEC14L3对乳腺癌的生存益处最大,选择SEC14L3进行后续研究(细胞生物学,分子生物层面)。在后续的研究重发现,SEC14L3 mRNA表达和蛋白表达情况,乳腺癌细胞系明显低于正常的乳腺上皮细胞。SEC14L3 过度表达可以抑制癌细胞迁移和侵袭的能力。SEC14L3 过表达降低了间质标志物的水平,而 SEC14L3 敲低则促进了乳腺癌细胞的恶性行为。SEC14L3 过表达还抑制了 Wnt/β-catenin 激活。乳腺癌细胞和组织中低表达的SEC14L3可能通过Wnt /β-catenin相关的方式发挥肿瘤抑制作用。
Abstract:
Breast cancer, the most prevalent malignancy in women, is also the leading cause of cancer-related deaths in women worldwide. The activation of the Wnt pathway plays a pivotal role in … >>>
Breast cancer, the most prevalent malignancy in women, is also the leading cause of cancer-related deaths in women worldwide. The activation of the Wnt pathway plays a pivotal role in the metastatic abilities of breast cancer. In this study, IL1F6, MRGPRX1, and SEC14L3 were significantly correlated to breast cancer patients'overall survival based on TCGA-BRCA dataset. Although IL1F6, MRGPRX1 and SEC14L3 high expression were associated with better survival in breast cancer patients, SEC14L3 had the biggest survival benefit for breast cancer; therefore, SEC14L3 was selected for the subsequent investigation. SEC14L3 mRNA expression and protein levels within breast cancer cell lines decreased compared with normal human breast epithelial cells. Overexpressing SEC14L3 in breast cancer cells inhibited the malignant phenotypes of cancer cells, including the capacity of cells to migrate and invade. SEC14L3 overexpression decreased the levels of mesenchymal markers, whereas SEC14L3 knockdown facilitated the malignant behaviors of breast cancer cells. SEC14L3 overexpression also inhibited Wnt/β-catenin activation. The Wnt agonist strengthened the malignant phenotypes of breast cancer cells; moreover, the anti-tumor effects of SEC14L3 overexpression were partially attenuated by the Wnt agonist. Conclusively, SEC14L3, which is underexpressed in breast cancer cells and tissues, could play a tumor-suppressive role in a Wnt/β-catenin-related way. <<<
翻译
19.
DeDe宝 (2024-09-12 14:24):
#paper, DOI: 10.1073/pnas.0805414105 ,Neural basis of the cognitive map: Path integration does not require hippocampus or entorhinal cortex. 研究主要探讨了海马体和内嗅皮层在记忆功能和空间认知中的作用,尤其是它们在路径整合能力中的作用。路径整合是指利用自身运动线索来跟踪参考位置的能力。当被试被要求蒙上眼睛导航并指向起点位置,海马体或内嗅皮层受损的被试表现与对照组相似。在距离估计任务中,受损组和对照组的估计也相似。只有在延迟和分心条件下,受损组表现不如对照组,显示了他们在长期记忆任务上的困难。上述结果表明,虽然海马体和内嗅皮层对于长期记忆至关重要,但它们对于路径整合的空间计算并不是必需的。
Abstract:
The hippocampus and entorhinal cortex have been linked to both memory functions and to spatial cognition, but it has been unclear how these ideas relate to each other. An important … >>>
The hippocampus and entorhinal cortex have been linked to both memory functions and to spatial cognition, but it has been unclear how these ideas relate to each other. An important part of spatial cognition is the ability to keep track of a reference location using self-motion cues (sometimes referred to as path integration), and it has been suggested that the hippocampus or entorhinal cortex is essential for this ability. Patients with hippocampal lesions or larger lesions that also included entorhinal cortex were led on paths while blindfolded (up to 15 m in length) and were asked to actively maintain the path in mind. Patients pointed to and estimated their distance from the start location as accurately as controls. A rotation condition confirmed that performance was based on self-motion cues. When demands on long-term memory were increased, patients were impaired. Thus, in humans, the hippocampus and entorhinal cortex are not essential for path integration. <<<
翻译
20.
惊鸿 (2024-09-11 14:53):
#paper Pub Date  : 2024-09-09 DOI : 10.1073/pnas.2403200121青春期是社会情感显着发展的时期,伴随着大脑结构和功能的巨大变化。由于 COVID-19 大流行而实施的封锁导致的社会隔离对青少年的心理健康产生了不利影响,其中女性的心理健康比男性受到的影响更大。我们评估了 COVID-19 大流行封锁对青少年大脑结构的影响,重点关注性别差异。我们纵向收集了大流行封锁前后青少年的 MRI 结构数据。新冠疫情前的数据用于创建典型青少年发育期间皮质厚度随年龄变化的规范模型。将新冠疫情后数据中的皮质厚度值与该规范模型进行了比较。分析显示,新冠疫情后大脑皮质加速变薄,这种现象在整个大脑中更为广泛,并且女性的程度比男性更大。当以同等发育年数来衡量时,女性的平均加速度为 4.2 岁,男性的平均加速度为 1.4 岁。发育过程中的慢性压力或逆境会导致大脑加速成熟,这一点已有充分记录。这些发现表明,与 COVID-19 大流行封锁相关的生活方式中断导致了大脑生物学的变化,并且对女性大脑的影响比男性大脑更严重。
Abstract:
Adolescence is a period of substantial social-emotional development, accompanied by dramatic changes to brain structure and function. Social isolation due to lockdowns that were imposed because of the COVID-19 pandemic … >>>
Adolescence is a period of substantial social-emotional development, accompanied by dramatic changes to brain structure and function. Social isolation due to lockdowns that were imposed because of the COVID-19 pandemic had a detrimental impact on adolescent mental health, with the mental health of females more affected than males. We assessed the impact of the COVID-19 pandemic lockdowns on adolescent brain structure with a focus on sex differences. We collected MRI structural data longitudinally from adolescents prior to and after the pandemic lockdowns. The pre-COVID data were used to create a normative model of cortical thickness change with age during typical adolescent development. Cortical thickness values in the post-COVID data were compared to this normative model. The analysis revealed accelerated cortical thinning in the post-COVID brain, which was more widespread throughout the brain and greater in magnitude in females than in males. When measured in terms of equivalent years of development, the mean acceleration was found to be 4.2 y in females and 1.4 y in males. Accelerated brain maturation as a result of chronic stress or adversity during development has been well documented. These findings suggest that the lifestyle disruptions associated with the COVID-19 pandemic lockdowns caused changes in brain biology and had a more severe impact on the female than the male brain. <<<
翻译
回到顶部