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1.
1.?State space models are starting to replace more simple time series models in analyses of temporal dynamics of populations that are not perfectly censused. By simultaneously modelling both the dynamics and the observations, consistent estimates of population dynamical parameters may be obtained. For many data sets, the distribution of observation errors is unknown and error models typically chosen in an ad-hoc manner. 2.?To investigate the influence of the choice of observation error on inferences, we analyse the dynamics of a replicated time series of red kangaroo surveys using a state space model with linear state dynamics. Surveys were performed through aerial counts and Poisson, overdispersed Poisson, normal and log-normal distributions may all be adequate for modelling observation errors for the data. We fit each of these to the data and compare them using AIC. 3.?The state space models were fitted with maximum likelihood methods using a recent importance sampling technique that relies on the Kalman filter. The method relaxes the assumption of Gaussian observation errors required by the basic Kalman filter. Matlab code for fitting linear state space models with Poisson observations is provided. 4.?The ability of AIC to identify the correct observation model was investigated in a small simulation study. For the parameter values used in the study, without replicated observations, the correct observation distribution could sometimes be identified but model selection was prone to misclassification. On the other hand, when observations were replicated, the correct distribution could typically be identified. 5.?Our results illustrate that inferences may differ markedly depending on the observation distributions used, suggesting that choosing an adequate observation model can be critical. Model selection and simulations show that for the models and parameter values in this study, a suitable observation model can typically be identified if observations are replicated. Model selection and replication of observations, therefore, provide a potential solution when the observation distribution is unknown.  相似文献   

2.
This paper discusses regression analysis of longitudinal data in which the observation process may be related to the longitudinal process of interest. Such data have recently attracted a great deal of attention and some methods have been developed. However, most of those methods treat the observation process as a recurrent event process, which assumes that one observation can immediately follow another. Sometimes, this is not the case, as there may be some delay or observation duration. Such a process is often referred to as a recurrent episode process. One example is the medical cost related to hospitalization, where each hospitalization serves as a single observation. For the problem, we present a joint analysis approach for regression analysis of both longitudinal and observation processes and a simulation study is conducted that assesses the finite sample performance of the approach. The asymptotic properties of the proposed estimates are also given and the method is applied to the medical cost data that motivated this study.  相似文献   

3.
Recently, automated observation systems for animals using artificial intelligence have been proposed. In the wild, animals are difficult to detect and track automatically because of lamination and occlusions. Our study proposes a new approach to automatically detect and track wild Japanese macaques (Macaca fuscata) using deep learning and a particle filter algorithm. Macaque likelihood is derived through deep learning and used as an observation model in a particle filter to predict the macaques’ position and size in an image. By using deep learning as an observation model, it is possible to simplify the observation model and improve the accuracy of the classifier. We investigated whether the algorithm could find body regions of macaques in video recordings of free‐ranging groups at Katsuyama, Japan to evaluate our model. Experimental results showed that our method with deep learning as an observation model had higher tracking accuracy than a method that uses a support vector machine. More generally, our study will help researchers to develop automatic observation systems for animals in the wild.  相似文献   

4.
The present study aimed to examine the working conditions of shift workers in a multinational enterprise in Thailand and to identify practical support measures for improvements. A multinational, glass-manufacturing factory employing 1,500 workers was selected as the research site. Three shift systems in three teams were adopted. A direct observation study and a fatigue feeling monitoring study were carried out to compare the differences between different shifts. A 10-day time-budget study was conducted for 30 shift workers to know their work and sleep patterns. The direct observation study identified safety and health risks during the night work periods. The risks included insufficient lighting, height gaps on the floor, excessive exposure to heat, inappropriate workstations, and sleepiness and fatigue feelings among shift workers. Working consecutive double shifts and overtime work was often seen. An advisory meeting was held based on the study findings to assist managers and workers in improving their working conditions. A follow-up visit six months later confirmed that the glass factory implemented several improvements to help night and shift workers. It was concluded that the direct observation methods associated with the time-budget study were helpful for identifying practical action points and strengthening workplace initiatives.  相似文献   

5.
Sonodynamic therapy (SDT) is one of antitumor strategies that kill tumor cells through the synergistic effects caused by the combined use of HpD and US[1]. SDT is based on the following principle. Ultrasound used in SDT can penetrate the deep tissue and activate HpD, which accu- mulated in tumor cell, and produce highly active oxygen species[2] such as singlet oxygen (1O2), which can destroy the structure of tumor cells. So far the studies on the SDT have focused mainly on the mechan…  相似文献   

6.
The inhibition of ascitic S180 and induced sarcoma 180 in vivo was studied with the combination of hematoporphyrin derivatives (HpD) and ultrasound (US) at the frequency of 1.1 MHz and different intensities by light microscopy observation, electronic microscopy observation, cytochemical analysis and fluorescence labeling. The present study indicated that the injury of ascitic S180 increased as time passed and the inhibitory effect was stronger in US plus HpD group than that in other groups. Our results also indicated that the changes in cell structure, cytochrome C oxidase activity, the degradation and missing of DNA were the important factors that inhibited the tumor cell growth and even induced celldeath. The phenomenon of apoptosis of tumor cells indicated that cell death andinduced apoptosis exist in the treatment of sonodynamic therapy (SDT). Our study investigated the mechanism underlying the killing effect of S180 induced by USactivating HpD by the observation of cell morphology and dynamic changes from seminal injury to succeeded injury even to death. It would provide rich referencefor the study of SDT.  相似文献   

7.
Wild chimpanzees make and use tools with far greater frequency and variety than wild baboons. Sampling differences; differences in the sensory, motor, or cognitive capacities for skilled tool use; or environmental differences are not responsible. Fortuitous discovery of novel forms of tool behavior probably occurs as rarely among chimpanzees as among baboons. However, research on wild and captive chimpanzees reveals that the discovery is transmitted quickly among chimpanzee groups by observation learning, and thus becomes well-established in the group's behavioral repertoire. In contrast, study of captive baboons reveals that they acquire little information about tool behavior by observation. With little observation learning the behavior is not likely to be acquired by other group members since repeated independent discovery is improbable. Thus chimpanzees' more proficient tool behavior is due mainly to their greater capacity for observation learning. This suggests that the advent of hominid tool traditions was accompanied by a capacity for facile observation learning and thus, perhaps, by language ability.  相似文献   

8.
为探讨认知护理干预对肝癌患者术后恢复的影响,本研究选取接受肝癌手术患者150例为观察对象,其中接受认知护理干预的患者84例,为观察组,接受普通护理的患者66例,为对照组。观察患者的疾病不确定感、疼痛程度、焦虑与抑郁(SAS与SDS)、生活质量和睡眠质量,评价认知干预对患者的影响。研究发现两组患者护理前疾病不确定感、SAS和SDS评分、睡眠质量和生活质量均无显著差异;护理后,观察组的疾病不确定感、SAS和SDS评分均极显著低于对照组(p<0.01),而睡眠质量和生活质量均显著高于对照组(p<0.01),观察组中度疼痛和重度疼痛患者明显少于对照组。研究表明认知护理干预有助于肝癌患者术后的恢复。  相似文献   

9.
This study was undertaken to identify the temporal characteristics of corticospinal excitability of tibialis anterior muscle during the observation of the initial phase of gait. For this purpose, using transcranial magnetic stimulation, we recorded motor evoked potentials (MEPs) during the observation of the second step of an actor’s first three steps of gait initiation with (complex gait) or without (normal gait) an obstacle and unstable surface. The results demonstrate that (1) MEPs during the observation of the initial phase of normal gait were significantly increased only at early swing phase, but not other phases (mid-swing, heel contact, mid-stance, and heel off) and (2) MEPs during the observation of the initial phase of complex gait were significantly increased at early swing and also at mid-swing and heel contact phases. These findings provide the first evidence that corticospinal excitability during the observation of gait, especially the initial phase, is modulated in phase- and motor-demanded-dependent manners.  相似文献   

10.
为探讨护理行为感知在前置胎盘剖宫产手术患者中应用的价值,本研究选取我院拟实施剖宫产的前置胎盘妊娠妇女90例,收集时间为2015年1月至2017年4月,随机将其分为观察组(手术期护理实施护理行为感知模式)和常规组(常规护理模式)各45例,并对比两组产妇术中出血量、术后24 h出血量、新生儿基本情况及产妇焦虑情绪变化情况。研究发现,观察组产妇的术中、术后24 h出血量均显著低于常规组,差异具有统计学意义(p<0.05);观察组和常规组的新生儿体质量差异无统计学意义(p>0.05);观察组新生儿1 min及5 min Apgar评分高于常规组,差异具有统计学意义(p<0.05);观察组的产后并发症发生概率为15.56%,显著低于常规组的35.56%,差异具有统计学意义(p<0.05);产前24 h、产后24 h,观察组的HAMA评分均低于常规组,差异具有统计学意义(p<0.05)。结果表明,护理行为感知在前置胎盘剖宫产手术患者中应用有利于减轻产妇的焦虑情绪、减少术中及术后出血量,提高新生儿的Apgar评分,并降低手术并发症的风险。  相似文献   

11.
Khurram Nadeem  Subhash R. Lele 《Oikos》2012,121(10):1656-1664
Population viability analysis (PVA) entails calculation of extinction risk, as defined by various extinction metrics, for a study population. These calculations strongly depend on the form of the population growth model and inclusion of demographic and/or environmental stochasticity. Form of the model and its parameters are determined based on observed population time series data. A typical population time series, consisting of estimated population sizes, inevitably has some observation error and likely has missing observations. In this paper, we present a likelihood based PVA in the presence of observation error and missing data. We illustrate the importance of incorporation of observation error in PVA by reanalyzing the population time series of song sparrow Melospiza melodia on Mandarte Island, British Columbia, Canada from 1975–1998. Using Akaike information criterion we show that model with observation error fits the data better than the one without observation error. The extinction risks predicted by with and without observation error models are quite different. Further analysis of possible causes for observation error revealed that some component of the observation error might be due to unreported dispersal. A complete analysis of such data, thus, would require explicit spatial models and data on dispersal along with observation error. Our conclusions are, therefore, two‐fold: 1) observation errors in PVA matter and 2) integrating these errors in PVA is not always enough and can still lead to important biases in parameter estimates if other processes such as dispersal are ignored.  相似文献   

12.
玉米叶面积指数动态模拟的最适野外观测资料   总被引:2,自引:0,他引:2  
基于锦州农田生态系统野外观测站2005-2011年多个品种的玉米大田试验资料,结合已经建立的玉米叶面积指数动态普适模型,探讨了准确模拟玉米叶面积指数动态所需的最适野外观测资料.结果表明: 准确模拟玉米叶面积指数动态至少需要3年的野外观测数据,且每年在生育期内至少需要进行4次观测.玉米生育期内的理想观测应为在出苗后20 d左右进行第1次观测,此后每月观测1次.
  相似文献   

13.
The coupling process between observed and performed actions is thought to be performed by a fronto-parietal perception-action system including regions of the inferior frontal gyrus and the inferior parietal lobule. When investigating the influence of the movements' characteristics on this process, most research on action observation has focused on only one particular variable even though the type of movements we observe can vary on several levels. By manipulating the visual perspective, transitivity and meaningfulness of observed movements in a functional magnetic resonance imaging study we aimed at investigating how the type of movements and the visual perspective can modulate brain activity during action observation in healthy individuals. Importantly, we used an active observation task where participants had to subsequently execute or imagine the observed movements. Our results show that the fronto-parietal regions of the perception action system were mostly recruited during the observation of meaningless actions while visual perspective had little influence on the activity within the perception-action system. Simultaneous investigation of several sources of modulation during active action observation is probably an approach that could lead to a greater ecological comprehension of this important sensorimotor process.  相似文献   

14.
为了比较丝线悬吊和微型钛板两种椎板固定方法对颈椎单开门椎管扩大成形术治疗多节段脊髓型颈椎病的影响,2016年4月至2018年1月期间,本研究选择我院收治的64例多节段脊髓型颈椎病患者作为研究对象。将患者随机分为对照组(丝线悬吊)和观察组(微型钛板固定),每组32例。比较两组的围手术期指标和治疗1年后的神经功能(JOA评分)、疼痛程度(VAS评分)、颈椎轴性症状、颈椎曲度和并发症。研究显示,两组患者的手术时间、术中出血量和引流量均无统计学差异(p>0.05)。两组患者术后的JOA评分和神经功能改善率无显著差异(86.36%vs.81.41%)(p>0.05)。术后观察组的VAS评分显著低于对照组(p=0.036)。观察组患者的颈椎轴性症状发生率(16.33%)显著低于对照组(25.58%)(Z=-2.024,p=0.043)。治疗12个月后观察组和对照组患者的颈椎曲度分别丢失了1.30%和4.62%,观察组颈椎曲度丢失量显著低于对照组(p=0.032)。本研究说明,在应用颈椎单开门椎管扩大成形术治疗多节段脊髓型颈椎病中,与丝线悬吊椎板固定相比,微型钛板固定可明显减少疼痛程度、颈椎曲度丢失和轴性症状的出现。  相似文献   

15.
栗黄枯叶蛾(Trabala vishnou Lefebure)属卷叶蛾属,危害10多种果树和林木花卉。1989年我们从四川大学校园内自然罹病死亡的大量栗黄枯叶蛾幼虫中,分离到一种栗黄枯叶蛾病原物。经纯化后,通过感染试验,涂片染色,电镜形态观察,超微结构研究,组织病理研究等,确认 该病原物为一种核型多角体病毒。  相似文献   

16.
This study aimed at assessing the effect of the observation method (direct or from video) and the effect of the presence of an observer on the behavioural results in veal calves kept on a commercial farm. To evaluate the effect of the observation method, 20 pens (four to five calves per pen) were observed by an observer for 60 min (two observation sessions of 30 min) and video-recorded at the same time. To evaluate the effect of the presence of the observer in front of the pen, 24 pens were video-recorded on 4 consecutive days and an observer was present in front of each pen for 60 min (two observation sessions of 30 min) on the third day. Behaviour was recorded using instantaneous scan sampling. For the study of the observer's effect, the analysis was limited to the posture, abnormal oral behaviour and manipulation of substrates. The two observation methods gave similar results for the time spent standing, but different results for all other behaviours. The presence of an observer did not affect the behaviour of calves at day level; however, their behaviour was affected when the observer was actually present in front of the pens. A higher percentage of calves were standing and were manipulating substrate in the presence of the observer, but there was no effect on abnormal oral behaviour. In conclusion, direct observations are a more suitable observation method than observations from video recordings for detailed behaviours in veal calves. The presence of an observer has a short-term effect on certain behaviours of calves that will have to be taken into consideration when monitoring these behaviours.  相似文献   

17.
目的:研究肱骨近端锁定加压钢板与解剖钢板治疗老年肱骨外科颈骨折的临床疗效。方法:选取92例老年肱骨外科颈骨折患者作为研究对象。根据数字法随机将患者分成观察组及对照组,各含46例。其中对照组予以解剖钢板术式治疗,观察组则予以肱骨近端的锁定加压钢板术式治疗。对比两组不同治法的疗效,两组患者的手术相关指标,两组患者治疗后的肩关节活动度以及两组患者治疗前后的Constant评分及VAS评分。结果:观察组的优良率是89.13%(41/46),显著高于对照组的76.09%(35/46),差异有统计学意义(P0.05)。观察组的术程、手术出血量以及住院时间和骨折的愈合时间均分别显著少于对照组,差异均有统计学意义(均P0.05)。观察组的肩关节活动度显著大于对照组,差均有统计学意义(P0.05)。治疗后观察组的Constant评分及VAS评分均分别显著高于对照组,差异均有统计学意义(均P0.05)。结论:利用肱骨近端的锁定加压钢板术式治疗FSNH,能够帮助患者获得更为积极的临床预后,值得在临床治疗过程中推广应用。  相似文献   

18.
为探讨个性化定制穿刺导板在椎间孔镜靶向穿刺中的应用,本研究选取2016年1月至2017年9月在我院治疗的腰椎间盘突出症患者52例,根据最终选取的治疗方案分为观察组(n=23)和对照组(n=29),对照组给予椎间孔镜靶向穿刺,观察组在对照组基础上给予个性化定制穿刺导板,观察两组治疗疗效、手术情况、术后疼痛程度及腰椎功能。结果表明:观察组和对照组术后疗效比较差异无统计学意义(p>0.05),术后优良率分别为86.96%和82.76%;观察组术中出血量、穿刺次数和穿刺时间分别为(14.58±3.21) m L、(1.43±0.41)次和(5.82±1.01) min,明显少于对照组(p<0.05);观察组和对照组术后3个月、6个月腰腿痛视觉模拟量表(visual analogue scale, VAS)评分和Oswestry功能障碍指数(oswestry disability index, ODI)比较差异无统计学意义(p>0.05)。本研究结论表明个性化定制穿刺导板在椎间孔镜靶向穿刺中有较好的应用价值,可提供穿刺准确性,值得推广应用。  相似文献   

19.
为了探讨儿童过敏性紫癜发病的危险因素,本研究选取了2015年7月至2017年6月在本院治疗的过敏性紫癜患儿118例作为观察组研究对象,同时选取健康正常儿童120例作为对照组,调查分析两组微生物感染、食物过敏、药物过敏史等资料,同时观察治疗疗效。研究显示,观察组的幽门螺杆菌(Hp)、肺炎支原体、链球菌感染率和螨虫阳性率分别为61.02%、16.10%、10.17%和13.56%,明显高于对照组(p<0.05);观察组对牛奶、鸡蛋、虾过敏的比例分别为9.32%、11.02%和8.47%,明显高于对照组(p<0.05);观察组有药物过敏史、家中饲养猫、狗等动物、家中近3个月装修的比例为22.88%、45.76%和17.80%,明显高于对照组(p<0.05);Logistic回归分析显示,Hp感染是发生过敏性紫癜的危险因素(OR=1.613, p<0.05);Hp感染和无Hp感染患者治疗疗效差异比较无统计学意义(p>0.05)。本研究表明,Hp感染可能是儿童过敏性紫癜发生的影响因素,但Hp感染对治疗疗效无明显影响。  相似文献   

20.
《Science activities》2012,49(2):63-73
Abstract

This study aimed to support the development of the scientific observation skills of children at an early age using a pattern selected from nearby nature. For this purpose, a simple, innovative and authentic observation activity was designed using thorny burnet (Sarcopoterium spinosum L.), a plant unique to the Mediterranean region. The activity was conducted in a preschool institution with six-year-old children in the class hours of a weekly science course in three different environments (in-class, out-of-class, and out-of-school), and seven stages. In this activity, which aimed to transform children’s natural/spontaneous observation skills into scientific observation skills, patterns were revealed through systematic and sequential observation and drawings. At the end of the activity, it was found that the children had developed skills related to breaking a whole into its parts and putting the parts together according to patterns, making detailed observations, and systematic data collection, and they successfully implemented these skills outside the classroom and school.  相似文献   

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