Interpreting a period-adding bifurcation scenario in neural bursting patterns using border-collision bifurcation in a discontinuous map of a slow control variable

To further identify the dynamics of the period-adding bifurcation scenarios observed in both biological experiment and simulations with differential Chay model, this paper fits a discontinuous map of a slow control variable of Chay model based on simulation results. The procedure of period adding bifurcation scenario from period k to period k ＋ 1 bursting （k = 1, 2, 3, 4） involved in the period-adding cascades and the stochastic effect of noise near each bifurcation point is also reproduced in the discontinuous map. Moreover, dynamics of the border-collision bifurcation is identified in the discontinuous map, which is employed to understand the experimentally observed period increment sequence. The simple discontinuous map is of practical importance in modeling of collective behaviours of neural populations like synchronization in large neural circuits.

Period-doubling bifurcation in two-stage power factor correction converters using the method of incremental harmonic balance and Floquet theory

In this paper, period-doubling bifurcation in a two-stage power factor correction converter is analyzed by using the method of incremental harmonic balance （IHB） and Floquet theory. A two-stage power factor correction converter typically employs a cascade configuration of a pre-regulator boost power factor correction converter with average current mode control to achieve a near unity power factor and a tightly regulated post-regulator DC-DC Buck converter with voltage feedback control to regulate the output voltage. Based on the assumption that the tightly regulated postregulator DC-DC Buck converter is represented as a constant power sink and some other assumptions, the simplified model of the two-stage power factor correction converter is derived and its approximate periodic solution is calculated by the method of IHB. And then, the stability of the system is investigated by using Floquet theory and the stable boundaries are presented on the selected parameter spaces. Finally, some experimental results are given to confirm the effectiveness of the theoretical analysis.

Stochastic period-doubling bifurcation analysis of stochastic Bonhoeffer-van der Pol system

In this paper, the Chebyshev polynomial approximation is applied to the problem of stochastic period-doubling bifurcation of a stochastic Bonhoeffer-van der Pol （BVP for short） system with a bounded random parameter. In the analysis, the stochastic BVP system is transformed by the Chebyshev polynomial approximation into an equivalent deterministic system, whose response can be readily obtained by conventional numerical methods. In this way we have explored plenty of stochastic period-doubling bifurcation phenomena of the stochastic BVP system. The numerical simulations show that the behaviour of the stochastic period-doubling bifurcation in the stochastic BVP system is by and large similar to that in the deterministic mean-parameter BVP system, but there are still some featured differences between them. For example, in the stochastic dynamic system the period-doubling bifurcation point diffuses into a critical interval and the location of the critical interval shifts with the variation of intensity of the random parameter. The obtained results show that Chebyshev polynomial approximation is an effective approach to dynamical problems in some typical nonlinear systems with a bounded random parameter of an arch-like probability density function.

Fourier Power Spectrum Analysis of Exons for the Period-3 Behavior

The period-3 behaviors of 105 exons from 20 genes in human were studied by Fourier power spectrum. The results indicated that not all exons show the period-3 behavior. The exons were adjusted in order to make them accord with the order of the protein translated, and we found that the period-3 character is relation to the length of exons and the bases distribution in the three codon position. Furthermore, as long as the exons with period-3 behavior accord with the order of protein translated, they would exhibit the synonymous codons usage preference, and the codons with g/c at the third position are used in higher frequency. The results are significant to the gene prediction and the research on the introns.

Period-One Rotating Solutions of Horizontally Excited Pendulum Based on Iterative Harmonic Balance

In this study, the iterative harmonic balance method was used to develop analytical solutions of period-one rotations of a pendulum driven horizontally by harmonic excitations. The performance of the method was evaluated by two criteria, one based on the system energy error and the other based on the global residual error. As a comparison, analytical solutions based on the multi-scale method were also considered. Numerical solutions obtained from the Dormand-Prince method (ODE45 in MATLAB&#169) were used as the baseline for evaluation. It was found that under lower-level excitations, the multi-scale method performed better than the iterative method. At higher-level excitations, however, the performance of the iterative method was noticeably more accurate.

Ultrashort optical pulse shaper based on complex-modulated long-period-grating coupler

In this paper,we present a novel ultrashort pulse shaper based on complex-modulated long-period-grating coupler（CM-LPGC）.Temporal rectangular waveform with 2-ps full width at half maximum（FWHM） is obtained by transforming the input Gaussian pulse.Tolerances of the CM-LPGC-based shaper to various non-ideal excitation conditions and fabricating errors are investigated.Results confirm that CM-LPGC is stable and suitable for optical pulse shaping operation.

Stochastic period-doubling bifurcation in biharmonic driven Duffing system with random parameter

Stochastic period-doubling bifurcation is explored in a forced Duffing system with a bounded random parameter as an additional weak harmonic perturbation added to the system. Firstly, the biharmonic driven Duffing system with a random parameter is reduced to its equivalent deterministic one, and then the responses of the stochastic system can be obtained by available effective numerical methods. Finally, numerical simulations show that the phase of the additional weak harmonic perturbation has great influence on the stochastic period-doubling bifurcation in the biharmonic driven Duffing system. It is emphasized that, different from the deterministic biharmonic driven Duffing system, the intensity of random parameter in the Duffing system can also be taken as a bifurcation parameter, which can lead to the stochastic period-doubling bifurcations.

Incidence trend of nasopharyngeal carcinoma from 1987 to 2011 in Sihui County,Guangdong Province,South China:an age-period-cohort analysis

Introduction:In the past several decades,declining incidences of nasopharyngeal carcinoma(NPC) have been observed in Chinese populations in Hong Kong,Taiwan,Los Angeles,and Singapore.A previous study indicated that the incidence of NPC in Sihui County,South China remained stable until 2002,but whether age,diagnosis period,and birth cohort affect the incidence of NPC remains unknown.Methods:Age-standardized rates(ASRs) of NPC incidence based on the world standard population were examined in both males and females in Sihui County from 1987 to 2011.Joinpoint regression analysis was conducted to quantify the changes in incidence trends.A Poisson regression age-period-cohort model was used to assess the effects of age,diagnosis period,and birth cohort on the risk of NPC.Results:The ASRs of NPC incidence during the study period were 30.29/100,000 for males and 13.09/100,000 for females.The incidence of NPC remained stable at a non-significant average annual percent change of 0.2%for males and-1.6%for females throughout the entire period.A significantly increased estimated annual percent change of 6.8%(95%confidence interval,0.1%-14.0%) was observed from 2003 to 2009 for males.The relative risk of NPC increased with advancing age up to 50-59 and decreased at ages >60 years.The period effect curves on NPC were nearly flat for males and females.The birth cohort effect curve for males showed an increase from the1922 cohort to the 1957 cohort and a decrease thereafter.In females,there was an undulating increase in the relative risk from the 1922 cohort to the 1972 cohort.Conclusions:The incidence trends for NPC remained generally stable in Sihui from 1987 to 2011,with an increase from 2003 to 2009.The relative risks of NPC increased in younger females.

Analysis of space harmonic selectivity of period-varying folded waveguide

A period-varying folded waveguide is formed by varying the period of a folded waveguide. It has the advantages of the space harmonic selectivity and the wide bandwidth. However, the regularities of the variety of these period-varying folded waveguides are unavailable from the published papers. In order to solve this problem, the principle of the space harmonic selectivity of a period-varying folded waveguide is analysed, and the conditions to select the space harmonic for this slow wave system are obtained. In addition, the space harmonic selectivities for a linear period-varying folded waveguide and a hyperbolic sine-varying period folded waveguide are also analysed as examples.

A reduced computational load protein coding predictor using equivalent amino acid sequence of DNA string with period-3 based time and frequency domain analysis

Development of efficient gene prediction algorithms is one of the fundamental efforts in gene prediction study in the area of genomics. In genomic signal processing the basic step of the identification of protein coding regions in DNA sequences is based on the period-3 property exhibited by nucleotides in exons. Several approaches based on signal processing tools and numerical representations have been applied to solve this problem, trying to achieve more accurate predictions. This paper presents a new indicator sequence based on amino acid sequence, called as aminoacid indicator sequence, derived from DNA string that uses the existing signal processing based time-domain and frequency domain methods to predict these regions within the billions long DNA sequence of eukaryotic cells which reduces the computational load by one-third. It is known that each triplet of bases, called as codon, instructs the cell machinery to synthesize an amino acid. The codon sequence therefore uniquely identifies an amino acid sequence which defines a protein. Thus the protein coding region is attributed by the codons in amino acid sequence. This property is used for detection of period-3 regions using amino acid sequence. Physico-chemical properties of amino acids are used for numerical representation. Various accuracy measures such as exonic peaks, discriminating factor, sensitivity, specificity, miss rate, wrong rate and approximate correlation are used to demonstrate the efficacy of the proposed predictor. The proposed method is validated on various organisms using the standard data-set HMR195, Burset and Guigo and KEGG. The simulation result shows that the proposed method is an effective approach for protein coding prediction.

Stochastic period-doubling bifurcation analysis of a Rssler system with a bounded random parameter

This paper aims to study the stochastic period-doubling bifurcation of the three-dimensional Rossler system with an arch-like bounded random parameter. First, we transform the stochastic RSssler system into its equivalent deterministic one in the sense of minimal residual error by the Chebyshev polynomial approximation method. Then, we explore the dynamical behaviour of the stochastic RSssler system through its equivalent deterministic system by numerical simulations. The numerical results show that some stochastic period-doubling bifurcation, akin to the conventional one in the deterministic case, may also appear in the stochastic Rossler system. In addition, we also examine the influence of the random parameter intensity on bifurcation phenomena in the stochastic Rossler system.

中青年缓解期精神分裂症患者社会疏离体验的质性研究

背景精神分裂症患者在整个生存期常感知到的较为严重的社会歧视,出现自我疏离或者社会性疏离。目前针对中青年缓解期精神分裂症患者社会疏离方面的研究较少。目的描述中青年缓解期精神分裂症患者社会疏离的体验,旨在为缓解该人群社会疏离体验制订支持干预方案提供一定的借鉴和参考。方法采用目的抽样法选取18~59岁,曾在新乡医学院第二附属医院住院且出院后愿意继续接受随访的中青年缓解期精神分裂症患者为研究对象,于2022年5—12月通过对受访者进行面对面半结构式深入访谈,并以内容分析法归纳和提炼主题。结果共纳入18名中青年缓解期精神分裂症患者。通过对访谈资料进行分析,共提炼出3个主题和8个亚主题:中青年缓解期精神分裂症患者社会疏离的表现(包括2个亚主题:负性情感体验、期待与行为之间的退缩);中青年缓解期精神分裂症患者社会疏离的主观原因(包括2个亚主题:自我疏离、自我歧视)、中青年缓解期精神分裂症患者社会疏离的客观原因(包括4个亚主题:社会歧视和被动疏离、药物不良反应的影响、精神疾病引起的生活和照护负担加重、缺乏社会支持)。结论中青年缓解期精神分裂症患者由于生理健康受损、心理状况不良、社会支持不足等存在社会疏离,医护人员应加强对该人群的症状管理和心理疏导,政府及社会各界应积极引导对精神疾病的正向认知并给予一定的社会支持;同时强化家庭内部支持,以帮助其重返和适应社会。

北五味子的采收加工与炮制研究进展

总结近年采收期对北五味子中木脂素、有机酸、多糖等多种成分的影响,考察晒干、阴干、烘干等产地初加工方法,以及醋制工艺、酒制工艺、盐制工艺等,炮制后北五味子中化学成分的变化,炮制后北五味子镇静催眠、降血糖、保肝和保肾等药理作用变化情况,指出北五味子具有多种药理活性,在多种常用复方中均有使用,应用前景广泛,但仍需要运用现代科学技术全面开展北五味子采收、加工、炮制等方面的研究,为北五味子的临床合理应用提供参考。

电针干预围绝经期失眠大鼠睡眠觉醒的实验研究

目的观察电针干预围绝经期失眠大鼠睡眠觉醒的效应并探索其相关机制。方法100只雌性成熟SD大鼠,随机分为假手术组(Sham组)、模型组(OVX组)、电针组(EA组)、假电针组(sham EA组),每组25只,除假手术组外,其余3组采用去卵巢(ovariectomized,OVX)术制备围绝经期大鼠失眠模型,电针组与假电针组于造模后给予电针或假电针干预,观察各组大鼠造模后、电针干预后睡眠觉醒状态、体质量、阴道脱落细胞、血清性激素水平、肾上腺皮质结构变化。结果OVX术后,模型组大鼠较假手术组大鼠日间觉醒增多,睡眠增多(rapid eye movement,REM),睡眠减少(non-rapid eye movement,NREM),难以维持长期睡眠,大鼠动情周期消失,停留在动情间期,体质量增加(P<0.05),血清雌激素水平降低(P<0.05),卵泡刺激素水平升高(P<0.05),肾上腺网状带细胞增生。电针干预后,OVX大鼠日间觉醒减少,NREM睡眠增多,NREM睡眠持续时间延长,大鼠阴道涂片中出现了类似动情后期表现的脱落细胞,体质量减少(P<0.05),血清雌激素水平升高(P<0.05),卵泡刺激素水平降低(P<0.05),肾上腺网状带细胞增生明显。结论(1)去卵巢手术使大鼠睡眠觉醒状态发生变化,呈现类似于人的围绝经期失眠。(2)电针干预能够改善OVX大鼠睡眠觉醒状态,增加NREM睡眠量,并增加NREM睡眠稳定性。(3)电针改善OVX大鼠睡眠状态可能是通过提高雌激素水平实现的,而肾上腺皮质网状带代偿性增生可能是雌激素水平升高的原因。

末次冰期东海嵊山岛黄土粒度端元分析及其环境意义

【目的】东海岛屿晚更新世风尘黄土堆积是我国黄土在东部长三角及外延海域重要的拓展,深化这一区域风尘黄土沉积的物源特征和后期演化问题研究,对于认识晚更新世区域古环境变化尤为重要。【方法】在OSL测年和磁化率测试基础上,基于东海岛屿典型风尘黄土剖面(嵊山岛黄土)的粒度分析,开展了粒度组成的端元分析,探讨了其蕴含的古环境信息。【结果与结论】嵊山岛黄土沉积可提取出3个粒度端元(EM1~EM3),进一步分析发现EM1可能代表通过高空西风气流传输的远源黏粒组分,EM2可能代表以浮尘形式远距离悬浮搬运并随风力减弱而沉降堆积的细粉砂组分,EM3可能代表冬季风驱动下的近地表短距离搬运堆积的粗粉砂组分。粒度端元分析结果表明,高空西风输送的黏粒端元组分和远距离悬浮运移的浮尘端元组分可能是沉积剖面主要粉尘来源;综合年代学结果、百分频率磁化率和颗粒中值粒径等参数分析,认为东海嵊山岛黄土沉积过程在MIS3阶段先后经历暖湿—冷干—暖湿的旋回波动;并且,所记录的MIS3阶段气候波动以及MIS2阶段末次冰盛期和冰消期的古环境变化同深海氧同位素和古海平面变化趋势相对应,说明东海陆架区域该时期环境演变与全球性气候波动相协同。

溯源弹簧形变过程的断路器振动信号递归量化分析辨识方法

从锁止机构脱扣引起储能弹簧释能,经部件带动动触头运动再到静止的每个动作具有严格阶段特征,伴随断路器动作的机械振动展现了能量传递及设备健康状态。该文提出一种溯源弹簧形变过程的断路器振动信号递归量化分析方法,首先由高速相机捕捉断路器操动时储能弹簧的动作图像,通过计算机视觉跟踪动态提取反映弹簧形变特征帧,再依据特征帧时序划分操动过程;然后将不同阶段振动信号映射至高维相空间,经递归分析得到体现动力系统变化特征的递归图,并递归量化分析其纹理结构特征;最后利用支持向量机模型对正常及故障状态下的断路器振动特征样本进行分析辨识,对比结果证明,由弹簧释能时序细化振动信号特征分析有效提高了分类识别准确率。该文方法在断路器操动机构状态辨识中具有广阔的应用前景。

泥石流危险范围Laharz修正模型及其应用

泥石流危险区研究涉及触发条件、物源与地形等多种因素,需要开发快速、有效的方法进行危险范围分析。本文基于Laharz基本原理,以泥石流样本为数据基础拟合得到修正模型,并以重庆市巫溪县杨家湾沟为例,采用修正的Laharz ArcGIS工具包,在不同降雨重现期条件下对泥石流堆积范围进行模拟计算。结果表明:1)采用修正参数使Laharz模型统计量参数的和方差(SSE)和均方根误差(RMSE)减小,确定系数(R^(2))增大,拟合优度得到明显提高;2)基于数字高程模型,结合现场调查推算的物源体积,在ArcGIS平台采用Laharz工具包可快速模拟不同降雨重现期(10、20、50、100 a)条件下的泥石流堆积范围,并且模拟泥石流堆积宽度与现场调查堆积范围接近,大部分重合;3)采用Laharz修正模型与传统的FLO-2D软件模拟进行对比,其中最远冲出距离、最大堆积宽度和堆积面积在两种方法下模拟结果的差值比率分别在10.00%、15.00%和20.00%量级,采用两种方法模拟结果与实地勘查结果也相近,表明Laharz修正模型具可靠性。

基于投影寻踪模型的特高含水油藏剩余油可采潜力评价方法

影响特高含水油藏剩余油可采潜力的因素极其复杂,且各因素的影响程度差异明显,常规方法多以剩余油饱和度或剩余油储量丰度等单一指标评价剩余油潜力,难以有效指导特高含水油藏剩余油挖潜。在充分考虑特高含水油藏剩余油可采潜力影响因素的基础上,综合表征储层非均质性、剩余油可采储量规模、水淹状况以及油水分流能力的差异,构建了特高含水油藏剩余油可采潜力量化评价指标体系,并考虑不同指标对剩余油可采潜力控制程度的差异,将加速遗传算法与投影寻踪模型相结合来确定各评价指标的客观权重,从而构建了剩余油可采潜力指数,形成特高含水油藏剩余油可采潜力量化评价新方法。以渤海Q油田南区主力产层NmIL砂体为例,开展特高含水油藏剩余油可采潜力量化评价,结果表明,新方法可综合表征不同区域位置的储层物性、可采储量丰度和油水分流能力对剩余油可采潜力的影响,实现了主力产层NmIL砂体剩余油可采潜力分布的差异化定量评价,优势可采潜力区域刻画明显,将其作为NmIL砂体下一步井网加密调整潜力区域,以精准指导加密水平井的部署,为特高含水油藏剩余油挖潜提供了一种全新的分析方法与思路。

近50年滇池流域汛期降水时空演变特征分析

以滇池流域1970—2020年汛期(5—10月)降水量资料为依据,利用地理信息技术,采用Mann-Kendall检验法、小波分析等方法,分析近50年来滇池流域汛期降水年际变化的趋势性、周期性以及集中度、集中期、降水中心和旱涝发生频率等演变特征。结果表明:(1)近50年来,滇池流域汛期降水总体呈减少趋势,中部地区降水呈增加趋势,盘龙江上游的松华坝水库以上区域及南部地区降水呈减少趋势;(2)汛期降水年际变化存在31 a的主周期,中部主城区降水集中度高于南部地区;(3)汛期降水的中心整体呈现向东部、南部方向偏移的态势,且移动趋势显著;(4)滇池流域旱涝频发,尤其盘龙江中段昆明主城区为旱涝多发区。该成果对滇池流域水旱灾害防御及水资源管理具有参考意义。

卡瑞利珠单抗、阿帕替尼联合卡培他滨二线治疗晚期三阴性乳腺癌的临床研究

目的探究卡瑞利珠单抗、阿帕替尼联合卡培他滨二线治疗晚期三阴性乳腺癌的临床效果。方法前瞻性选取2020年1月至2022年1月郑州大学第二附属医院收治的122例晚期三阴性乳腺癌患者纳入研究,按随机数表法分为观察组和对照组各61例,对照组患者采用阿帕替尼+卡培他滨二线治疗,观察组患者在对照组治疗的基础上联合卡瑞利珠单抗治疗。一个疗程21 d,治疗2个疗程。治疗2个疗程后,比较两组患者的临床疗效,以及治疗前后的肿瘤标志物水平[糖类抗原15-3(CA15-3)、癌胚抗原(CEA)]和免疫功能,同时比较两组患者治疗期间的药物不良反应。随访1年,比较两组患者的生存情况。结果观察组患者的客观缓解率和疾病控制率分别为59.02%、81.97%,明显高于对照组的39.34%、65.57%,差异均有统计学意义(P<0.05);治疗前,两组患者的血清CA15-3、CEA水平比较差异均无统计学意义(P>0.05),治疗后,两组患者的血清CA15-3、CEA水平均降低,且观察组明显低于对照组,差异均有统计学意义(P<0.05);治疗后,两组患者的CD3+、CD8+水平均升高,且观察组明显高于对照组,治疗后,两组患者的CD4+均降低,且观察组明显低于对照组,差异均有统计学意义(P<0.05);两组患者治疗期间的不良反应发生率比较差异均无统计学意义(P>0.05)。随访1年,观察组失访1例,对照组失访2例,观察组患者的中位无进展生存时间为11.55个月,明显长于对照组的6.98个月,差异有统计学意义(P<0.05)。结论卡瑞利珠单抗、阿帕替尼联合卡培他滨二线治疗晚期三阴性乳腺癌,可有效调节患者的肿瘤标志物,提高客观缓解率,促进免疫功能的恢复、延长患者的生存期且安全性良好。