A model for evaluating knowledge exchange in a network context

There is growing interest in the use of networks to facilitate the exchange and transfer of knowledge in health-care settings. The province of Ontario's Seniors Health Research Transfer Network (SHRTN) brings together caregivers, policymakers, and researchers working in the area of seniors' health to share knowledge derived from research and best practices. As part of an evaluation of SHRTN, the authors developed a model for assessing the effectiveness of knowledge exchange activities in a network context. The model considers the key elements of successful application of research evidence proposed in the Promoting Action on Research in Health Services (PARiHS) framework, as well as the results of these efforts, at 3 levels of network functioning. This model was used in a test of SHRTN's effectiveness as a knowledge exchange system. The results suggest that the framework has potential as a guide for evaluating other knowledge networks.     

Hemispheric specialization of the lateral prefrontal cortex for strategic processing during spatial and shape working memory

OBJECTIVE: We investigated whether spatial working memory (WM) is associated with functional specialization of the right prefrontal cortex (PFC) relative to WM for shapes. We designed spatial and shape WM tasks that are relatively easy to perform and that minimize both task-switching and manipulation demands. The tasks use identical stimuli and require the same motor response. METHODS: We presented 12 subjects with target shapes that appeared in particular locations. Subjects maintained either the location or the shape of the targets in WM and responded to each probe by indicating whether it was a target. During a non-WM control task, subjects indicated whether the probe appeared on the right or left side of the screen. Subjects were scanned with a 3.0 T Siemens scanner and data were analyzed using SPM99. The WM tasks were compared to identify PFC activation that was different for spatial versus shape WM. Each WM task was also compared to the control task. RESULTS: compared with shape WM, spatial WM performance was faster and more accurate and was associated with increased right ventrolateral and frontopolar PFC activation. In contrast, compared to spatial WM, shape WM was associated with increased left ventrolateral PFC activity. CONCLUSIONS: These findings demonstrate hemispheric specialization for spatial versus shape WM in the ventrolateral PFC. The increased activity in the right PFC for spatial WM cannot be attributed to increased task difficulty, the stimuli used, or the response requirements. Rather, we propose that differences in performance and activation reflect the use of configural processing strategies for spatial WM.     

Boundary-aware context neural network for medical image segmentation

Medical image segmentation can provide a reliable basis for further clinical analysis and disease diagnosis. With the development of convolutional neural networks (CNNs), medical image segmentation performance has advanced significantly. However, most existing CNN-based methods often produce unsatisfactory segmentation masks without accurate object boundaries. This problem is caused by the limited context information and inadequate discriminative feature maps after consecutive pooling and convolution operations. Additionally, medical images are characterized by high intra-class variation, inter-class indistinction and noise, extracting powerful context and aggregating discriminative features for fine-grained segmentation remain challenging. In this study, we formulate a boundary-aware context neural network (BA-Net) for 2D medical image segmentation to capture richer context and preserve fine spatial information, which incorporates encoder-decoder architecture. In each stage of the encoder sub-network, a proposed pyramid edge extraction module first obtains multi-granularity edge information. Then a newly designed mini multi-task learning module for jointly learning segments the object masks and detects lesion boundaries, in which a new interactive attention layer is introduced to bridge the two tasks. In this way, information complementarity between different tasks is achieved, which effectively leverages the boundary information to offer strong cues for better segmentation prediction. Finally, a cross feature fusion module acts to selectively aggregate multi-level features from the entire encoder sub-network. By cascading these three modules, richer context and fine-grain features of each stage are encoded and then delivered to the decoder. The results of extensive experiments on five datasets show that the proposed BA-Net outperforms state-of-the-art techniques.     

Neural correlates of context memory with real-world events

There has been little evidence for the difference in the retrieval processes of when and where something happened, one of the important factors in understanding episodic memory. We used positron emission tomography (PET) to identify the neural networks associated with temporal and spatial context memory of events experienced under experimental conditions similar to those of everyday life. Before PET, subjects experienced 36 events. The events were divided into four groups of nine each. The subjects experienced the first two groups of events before a 15-min recess and the other two after the recess; they experienced the first and last groups of events in one room, took a recess in another room, and experienced the second and third groups in a different room. During PET, the subjects were scanned under three different retrieval tasks: a time-retrieval task, a place-retrieval task, and a simple recognition task. The results showed that the retrieval of time and space, compared with the simple recognition, was associated with activity in substantially different regions as well as a common region: time retrieval with the posterior part of the right orbitofrontal cortex and left inferior parietal lobule, place retrieval with two regions in right parietal association cortex, right posterior cingulate gyrus, left precentral gyrus, and right cerebellum, and both with the right inferior frontal gyrus. These findings indicate that there are unique areas, in addition to a common area, for retrieving temporal and spatial context.     

Maintenance and manipulation in spatial working memory: dissociations in the prefrontal cortex

Two experiments were conducted to compare thec ries of the functional organization of spatial working memory within the human prefrontal cortex. In Experiment I, memory set size for locations was parametrically varied, allowing for the assessment of BOLD signal across maintenance requirements. In the sec ond experiment, manipulation of spatial information held in working memory was contrasted with simple maintenance of that information. Both experiment evoked significant activity in a distributed spatia working memory network. Although dorsolateral prefrontal activation increased monotonically with memory set size, this region was differentially engaged in task conditions involving explicit manipulation of in ternal representations. Activation in the superior frontal sulcal region was associated with maintenance of spatial information, increasing with memory se size. In contrast, ventrolateral prefrontal activation was present only at the highest memory set size, possibly due to the differential use of organizational strategies with more complex stimuli. These results sup port claims that the dorsolateral prefrontal cortex is involved in the manipulation of internal representa tions and that the superior frontal sulcal region is involved in the maintenance of spatial information but they suggest a complex role for the ventrolatera prefrontal region.     

PainNetworks: A web-based resource for the visualisation of pain-related genes in the context of their network associations

Hundreds of genes are proposed to contribute to nociception and pain perception. Historically, most studies of pain-related genes have examined them in isolation or alongside a handful of other genes. More recently the use of systems biology techniques has enabled us to study genes in the context of the biological pathways and networks in which they operate.     

The posterior cingulate and medial prefrontal cortex mediate the anticipatory allocation of spatial attention

The purpose of this study was to identify brain regions underlying internally generated anticipatory biases toward locations where significant events are expected to occur. Subjects fixated centrally and responded to peripheral targets preceded by a spatially valid (predictive), invalid (misleading), or neutral central cue while undergoing fMRI scanning. In some validly cued trials, reaction time was significantly shorter than in trials with neutral cues, indicating that the cue had successfully induced a spatial redistribution of motivational valence, manifested as expectancy. The largest cue benefits led to selectively greater activations within the posterior cingulate and medial prefrontal cortex. These two areas thus appear to establish a neural interface between attention and motivation. An inverse relationship to cue benefit was seen in the parietal cortex, suggesting that spatial expectancy may entail the inhibition of attention-related areas to reduce distractibility by events at irrelevant locations.     

Functional network in the prefrontal cortex during episodic memory retrieval

A recent consistent finding in neuroimaging studies of human memory is that the prefrontal cortex (PFC) is activated during episodic memory retrieval. To date, however, there has been no direct evidence to explain how activity in the right and left PFC and in the anterior and posterior PFC are functionally interconnected. The goal of the present study was to obtain such evidence by event-related functional magnetic resonance imaging (MRI) and the functional connectivity method. Subjects were first asked to try to remember a series of associate-word lists outside the MRI scanner in preparation for a later recognition test. In the MRI scanning phase, they were asked to make recognition judgments in regard to old words, semantically related lure words, and unrelated new words. The analysis of functional connectivity revealed that the posterior PFC in each hemisphere had strong functional interconnections with the contralateral posterior PFC, whereas the anterior PFC in each hemisphere had only weak functional interconnections with the contralateral anterior PFC. No strong functional interconnections were found between the anterior and posterior PFC in either hemisphere. These findings support the hypothesis of an associative contribution of the bilateral posterior PFC to episodic memory retrieval and a dissociative contribution of the bilateral anterior PFC.     

Ventromedial prefrontal volume predicts understanding of others and social network size

Cognitive abilities such as Theory of Mind (ToM), and more generally mentalizing competences, are central to human sociality. Neuroimaging has associated these abilities with specific brain regions including temporo-parietal junction, superior temporal sulcus, frontal pole, and ventromedial prefrontal cortex. Previous studies have shown both that mentalizing competence, indexed as the ability to correctly understand others' belief states, is associated with social network size and that social group size is correlated with frontal lobe volume across primate species (the social brain hypothesis). Given this, we predicted that both mentalizing competences and the number of social relationships a person can maintain simultaneously will be a function of gray matter volume in these regions associated with conventional Theory of Mind. We used voxel-based morphometry of Magnetic Resonance Images (MRIs) to test this hypothesis in humans. Specifically, we regressed individuals' mentalizing competences and social network sizes against gray matter volume. This revealed that gray matter volume in bilateral posterior frontal pole and left temporoparietal junction and superior temporal sucus varies parametrically with mentalizing competence. Furthermore, gray matter volume in the medial orbitofrontal cortex and the ventral portion of medial frontal gyrus, varied parametrically with both mentalizing competence and social network size, demonstrating a shared neural basis for these very different facets of sociality. These findings provide the first fine-grained anatomical support for the social brain hypothesis. As such, they have important implications for our understanding of the constraints limiting social cognition and social network size in humans, as well as for our understanding of how such abilities evolved across primates.     

护理不良事件计算机网络管理系统的设计与临床应用

目的提高护理不良事件报告的准确性和及时性,为护理不良事件的管理提供依据。方法建立护理不良事件网络上报与监管系统,通过模块分析,找准事件原因、修订制度和流程、强化重点环节及重点人群的管理。结果护理不良事件上报时间缩短、护理不良事件的重复发生率及严重程度降低(P<0.05)。结论护理不良事件计算机系统是实现护理不良事件网络上报和管理的有效手段。     

The challenges of searching for and retrieving qualitative studies

The authors' purpose in this article is to report the results of their search and retrieval efforts to date in an ongoing study to develop the procedural, analytic, and interpretive techniques to conduct qualitative meta-synthesis projects, using studies on women with HIV infection as the method case. For researchers conducting qualitative meta-synthesis projects, the ideal goal is to retrieve all of the relevant studies in a field--not simply a sample of them. Bates's model of berrypicking is used as the framework to describe the techniques used to conduct these searches. The authors discuss, in particular, the challenges of working with bibliographic databases, including choosing which databases to search, learning about the idiosyncrasies of working with each database, developing a list of search terms, and refining inclusion criteria regarding which studies to include in the meta-synthesis. Recommendations are given for searchers and writers of qualitative research.     

Dissociable brain activations during the retrieval of different kinds of spatial context memory

Although memory for spatial information has often been regarded as unitary, it may be divided into two distinct types: memory for the place where an individual experienced an event and memory for the location of an experienced event within a specific reference object. We used functional magnetic resonance imaging (fMRI) to elucidate the distinctions between the retrieval of these two types of spatial context memory. During scanning, subjects judged the room (Place task) in which a photograph had been presented or the location of the photograph on the computer display (R-L task) during the encoding phase. In a control task, subjects were asked to judge whether the photograph had been presented or not. The left middle frontal gyrus, lateral parietal and occipital regions, and bilateral precunei were found to be active during both the Place task and the R-L task compared with the control task. Critically, the place task, compared with the R-L task, was associated with activations in the right lateral prefrontal gyri, the posterior part of the left parahippocampal gyrus, bilateral retrosplenial and lateral parieto-occipital areas, whereas the R-L task, relative to the place task, with activation only in the right lateral parietal cortex. These findings indicate that the retrieval processes of spatial context memory are not associated with a single network, but may vary and recruit different neural networks depending on the type of spatial information to be retrieved.     

Refined prefrontal working memory network as a neuromarker for Alzheimer’s disease

Detecting Alzheimer’s disease (AD) is an important step in preventing pathological brain damage. Working memory (WM)-related network modulation can be a pathological feature of AD, but is usually modulated by untargeted cognitive processes and individual variance, resulting in the concealment of this key information. Therefore, in this study, we comprehensively investigated a new neuromarker, named “refined network,” in a prefrontal cortex (PFC) that revealed the pathological features of AD. A refined network was acquired by removing unnecessary variance from the WM-related network. By using a functional near-infrared spectroscopy (fNIRS) device, we evaluated the reliability of the refined network, which was identified from the three groups classified by AD progression: healthy people (N=31), mild cognitive impairment (N=11), and patients with AD (N=18). As a result, we identified edges with significant correlations between cognitive functions and groups in the dorsolateral PFC. Moreover, the refined network achieved a significantly correlating metric with neuropsychological test scores, and a remarkable three-class classification accuracy (95.0%). These results implicate the refined PFC WM-related network as a powerful neuromarker for AD screening.     

双侧前额叶中度损伤大鼠执行控制和空间学习与记忆功能的研究

摘要 目的：通过控制性皮质撞击法,制作双侧前额叶中度损伤模型并观察其对大鼠的执行控制功能和空间学习与记忆功能的影响。 方法：40只雄性SD大鼠随机分成3组：正常对照组（n=10）、假手术组（n=10）、控制性皮质撞击（CCI）组（n=20）。CCI组大鼠应用控制性皮质撞击法制作双侧额叶打击颅脑创伤模型,其中打击速度：3.5m/s,打击深度：1.5mm,停留时间：400ms。于CCI后第4周末及第8周末分别进行GO/NO GO任务测试及水迷宫测试。 结果：造模前各组各测试均无显著差异。造模后第4周CCI组GO/NO GO任务测试可见正确率显著下降（P＜0.01）,造模后第8周,各组的正确率下降和造模前比均有显著性差异（P＜0.05）。造模后定位航行实验可见各组潜伏期均有下降,对照组和假手术组下降有显著性差异（P＜0.05）,但CCI组无显著性差异;第4、8周,与对照组相比,CCI组则均有显著性差异（P＜0.01）。造模后第4周空间探索实验可见,对照组和假手术组与造模前相比无显著性差异（P＞0.05）,CCI组则有显著下降（P＜0.01）;造模后第8周,假手术组和CCI组与造模前相比差异有显著性意义（P＞0.05）,CCI组则与第4周相比也有显著差异（P＜0.01）。 结论：应用CCI方法进行双侧前额叶撞击制备大鼠中度颅脑创伤模型,可以造成大鼠执行控制能力的显著下降,并对大鼠的空间学习和记忆能力均有严重影响。在伤后一定时间内,执行控制能力可能会有部分的自然恢复,但空间学习和记忆能力损害则可能进行性加重。     

浙江省护理不良事件网络上报系统的构建和应用

目的 构建浙江省护理不良事件网络上报系统,建立统一模式的信息化平台,使护理不良事件的管理更加规范化和科学化.方法 根据5W1H(what\where\when\who\why\how)的思路和国家患者安全机构(national patient safety agency)推荐的不良事件因子分类系统及相关文献,结合浙江省的实际情况,构建了护理不良事件网络上报系统.结果 该上报系统具有非惩罚性、保密性、独立性、时效性、专家分析、针对系统等特点,充分体现7护理安全管理中科学、人性化的特点.结论 该上报系统实现了最大限度地收集、分析、交流、共享安全信息,促进了护理安全管理的持续改进.     

Deriving the optimal number of events for an event-related fMRI study based on the spatial extent of activation

Event-related fMRI is a powerful tool for localising psychological functions to specific brain areas. However, the number of events required to produce stable activation maps is a poorly investigated and understood problem. Huettel and McCarthy [Huettel, S.A., McCarthy, G., 2001. The effects of single-trial averaging upon the spatial extent of fMRI activation. NeuroReport 12, 2411-2416] have shown that the spatial extent of activation increases monotonically with the number of events in an analysis. In the present paper, this result is replicated and shown to be a consequence of the cross-correlation technique used to determine active voxels and does not hold, for example, for a GLM analysis. Another analysis technique, that does not depend on goodness-of-fit to the data, is also proposed. This technique calculates an impulse response function (IRF) for each voxel, finds the best fitting haemodynamic shape to the IRF and returns an area-under-the-curve (%AUC) activation measure. Using spatial extent as a measure, asymptotic behaviour is evident after as few as 25 events for the %AUC analysis technique in a finger-tapping task with non-overlapping haemodynamic responses and for both the GLM and %AUC techniques in a similar task that allows responses to overlap. The experimental validity of the %AUC technique to identify active brain regions while minimising false positive levels is demonstrated in a group study with 25 participants.     

Techniques for locating, filing, and retrieving scientific information

Guidelines for improving the effectiveness and efficiency of conducting a search of scientific literature are presented. Initial leads can be gained by contacting a local expert or consulting a textbook. An impression of advances being made in a particular field can be gained efficiently by scanning weekly issues of Current Contents, containing the tables of contents of most scientific journals. Recent review articles on most topics can usually be found listed in the Index Medicus. With at least one significant reference dealing with a specific topic of interest, the Science Citation Index may be used to identify articles published during a particular indexing period which cited the article as a reference. Practical guidelines are also presented for establishing a simple but comprehensive personal system for filing and retrieving on demand reprints, pamphlets, and notes.     

A model for evaluating the context of nursing care delivery

This study used a mixed method to test a model of demands on nurses. Factors were identified that affect demands, and a model was tested using structural equation modeling. Teamwork and expertise had significant effects on nurse-sensitive outcomes. Leadership was a strong determinant of stability and expertise. Workload was not a significant predictor of outcomes, but this is likely due to the difficulty in measuring nursing work. These results provide administrators with actionable recommendations that can be used to reduce the demands on nursing staff.