Extraction of artefactual MRS patterns from a large database using non-negative matrix factorization

Despite the success of automated pattern recognition methods in problems of human brain tumor diagnostic classification, limited attention has been paid to the issue of automated data quality assessment in the field of MRS for neuro-oncology. Beyond some early attempts to address this issue, the current standard in practice is MRS quality control through human (expert-based) assessment. One aspect of automatic quality control is the problem of detecting artefacts in MRS data. Artefacts, whose variety has already been reviewed in some detail and some of which may even escape human quality control, have a negative influence in pattern recognition methods attempting to assist tumor characterization. The automatic detection of MRS artefacts should be beneficial for radiology as it guarantees more reliable tumor characterizations, as well as the development of more robust pattern recognition-based tumor classifiers and more trustable MRS data processing and analysis pipelines. Feature extraction methods have previously been used to help distinguishing between good and bad quality spectra to apply subsequent supervised pattern recognition techniques. In this study, we apply feature extraction differently and use a variant of a method for blind source separation, namely Convex Non-Negative Matrix Factorization, to unveil MRS signal sources in a completely unsupervised way. We hypothesize that, while most sources will correspond to the different tumor patterns, some of them will reflect signal artefacts. The experimental work reported in this paper, analyzing a combined short and long echo time ¹H-MRS database of more than 2000 spectra acquired at 1.5T and corresponding to different tumor types and other anomalous masses, provides a first proof of concept that points to the possible validity of this approach.     

The acquisition of allophones among bilingual Spanish–English and French–English 3-year-old children

Children are exposed to highly variable input from multiple sources within their speech community. This study examines the acquisition of allophones in Spanish and French by monolingual and bilingual children. We hypothesised that two factors would influence allophone acquisition: (1) the amount of exposure to phonological input, and (2) the degree of variability of the allophonic pattern. Thirty-four typically developing 3-year-old participated in the study. The analyses revealed that regardless of the language, the monolingual children produced similar error rates in the production of the target allophones. In contrast, the bilingual children produced different patterns of acquisition of the allophones: the Spanish–English bilinguals produced higher error rates than the monolinguals, whereas the French–English bilinguals produced lower error rates than the monolinguals. Possibilities for these differences are discussed within the context of structural complexity as well as in light of the effects of between-language interaction on bilingual phonological development.     

Divergently Seeking Clarification: The Emergence of Clarification Interaction

Clarification requests, queries posed in response to a “problematic” (misheard, misunderstood, etc.) utterance, are a challenge to mainstream semantic theories because they call into question notions such as “shared content” or “the context.” Given their strong parallelism requirements, elliptical clarification requests introduce in addition significant complexities concerning the need for long-term maintenance of non-semantic information in context. In this paper, we consider a puzzle concerning the emergence of elliptical clarification requests in child English: Data from the Belfast and Manchester corpora from CHILDES demonstrate that reprise fragments, the highest frequency clarification request construction among adults, emerges with significant delay in comparison with reprise sluices, bare wh-phrases used to request clarification. This is a puzzling finding a priori: first, since reprise fragments are by most plausible measures the most readily available clarification request form in that it involves mere repetition of material primed by the previous utterance and children have the ability to repeat parts of the previous utterance from the earliest stages of speech. Moreover, as we show, reprise fragments predominate—in some cases vastly so, over sluicing in the input of fragmentary clarification requests available to the child—and it would, therefore, be difficult to construct an explanation for order of emergence primarily based on frequency of the construction in the children's input. Our account is based on grammatical explication of the difference between the constructions, how constructional difference is represented in a hierarchy of constructions, and in terms of a notion of semantic complexity that suggests reprise sluicing is, in fact, less complex than reprise fragments.     

Development of constructed phrases in a child with language impairment

The emerging use of constructed utterances by a pre-school boy who initially used single words and routine phrases is described during a 7-month period, from 4;8-5;3. Emerging constructed phrases were consistent with a mixture of gestalt and analytic acquisition strategies. Some constructed phrases were variations on earlier routine phrases, and others were combinations of words that did not appear in earlier routines. Discussion of the child's course of language development is related to the literature on typical language acquisition and a model of language development in individuals with autism.     

金平区居民防癌知识及获取途径的调查

目的 了解汕头市金平区居民对防癌知识的认知情况以及获取途径,为有针对性开展健康教育提供依据.方法 采用自制的居民癌症预防知、信、行调查问卷对3678 名居民进行调查.结果 居民对癌症病因、诱因知晓率最高的是工业产生的废气、废水（88.4%）,癌症常见的早期症状知晓率最高的是身体任何部位出现无痛性肿块并逐渐增大（75.7%）,癌症预防行为认知率最高的是保持良好的卫生习惯（81.6%）.居民认为较好的健康教育途径是社区卫生服务中心（ 或） 站防癌讲座（53.3%）、向医务人员咨询（51.5%）.结论 金平区居民对癌症知识的认知不够,应开展多种形式健康教育,提高居民防癌意识.     

医学会议文献的传播模式和获取策略研究

介绍医学会议文献发展状况及特点，总结归纳它的传播模式及存在形式，分析医学文献获取成本，并进一步提出正式出版、有权限限制、开放获取及个人形式发布的医学会议文献的获取策略。     

A new method for the acquisition of ultrasonic strain image volumes

This article presents a new method for acquiring three-dimensional (3-D) volumes of ultrasonic axial strain data. The method uses a mechanically-swept probe to sweep out a single volume while applying a continuously varying axial compression. Acquisition of a volume takes 15-20 s. A strain volume is then calculated by comparing frame pairs throughout the sequence. The method uses strain quality estimates to automatically pick out high quality frame pairs, and so does not require careful control of the axial compression. In a series of in vitro and in vivo experiments, we quantify the image quality of the new method and also assess its ease of use. Results are compared with those for the current best alternative, which calculates strain between two complete volumes. The volume pair approach can produce high quality data, but skillful scanning is required to acquire two volumes with appropriate relative strain. In the new method, the automatic quality-weighted selection of image pairs overcomes this difficulty and the method produces superior quality images with a relatively relaxed scanning technique. (E-mail: rjh80@eng.cam.ac.uk)     

A comparative study of the phonology of pre-school children with specific language impairment (SLI), language delay (LD) and normal acquisition

The phonology of two groups of SLI (n =5) and LD (n =5) children was analysed at age 3 and compared with two control groups: an age control (n =5) and a language level control (measured using the MLU-W) (n =5). Children with SLI and LD showed a delay in the acquisition of segments, syllabic structures and word structures, and in the simplification processes, compared with their age control group. However, SLI children also displayed significant differences vis-à-vis their language level controls, mainly in early acquisitions: vowels, nasals and stops at the segmental level, and in CV structures at the syllabic level. There is also a simplification process that seems to be more prevalent in these children than in their language level controls, namely, the deletion of unstressed syllables, mainly initial ones. The results enable SLI to be distinguished from LD and suggest that the development of SLI phonology is deviant. This deviation is interpreted as being a plateau in early acquisitions when later acquisitions have already appeared. The results are considered in the light of Leonard's surface hypothesis and an exclusively linguistic cause for this disorder is ruled out.     

Development and validation of an instrument to measure nurse educator perceived confidence in clinical teaching

Teaching nursing in clinical environments is considered complex and multi‐faceted. Little is known about the role of the clinical nurse educator, specifically the challenges related to transition from clinician, or in some cases, from newly‐graduated nurse to that of clinical nurse educator, as occurs in developing countries. Confidence in the clinical educator role has been associated with successful transition and the development of role competence. There is currently no valid and reliable instrument to measure clinical nurse educator confidence. This study was conducted to develop and psychometrically test an instrument to measure perceived confidence among clinical nurse educators. A multi‐phase, multi‐setting survey design was used. A total of 468 surveys were distributed, and 363 were returned. Data were analyzed using exploratory and confirmatory factor analyses. The instrument was successfully tested and modified in phase 1, and factorial validity was subsequently confirmed in phase 2. There was strong evidence of internal consistency, reliability, content, and convergent validity of the Clinical Nurse Educator Skill Acquisition Assessment instrument. The resulting instrument is applicable in similar contexts due to its rigorous development and validation process.     

飞利浦DR图像处理计算机工作原理及软件安装

目的:为减少飞利浦DR图像处理计算机停机时间,排除飞利浦DR图像处理计算机的软件故障.方法:通过介绍飞利浦DR图像处理计算机的硬件结构及工作原理,详细描述图像处理流程,讲解软件安装和校准方法,解决安装过程中所遇到的各种问题.结果:通过优化后的安装方法,可以快速排除软件故障.结论:医院医疗仪器维修工程师通过研究技术资料,不断总结经验,可以对大型医疗设备进行维修