A picture speaks a thousand words? Vision,visuality and authorization

Abstract

Images of brains circulate today as rationales for decision-making and selectivity in policies, curriculum, preservice teacher education and inservice professional development. The excitement over brain-based research, its visual reach and authorizing role accompanies longstanding debates in which the status attributed to biology, physiology and allied psychological approaches has been considered prejudicial. This article traces a series of dislocations in the linkages forged between discourses of vision and epistemic authorization, and how they still inhere in contemporary debates over brain imaging. The critical history that the article offers within the general framework of Visual science and technology studies requires questioning some of the core tenets of visual culture, including what gets to count as the visual, ‘its’ role in legitimation, and the primacy assigned to looking and observation as strategies of truth-production.     

“Let's Get Physical”: Advantages of a physical model over 3D computer models and textbooks in learning imaging anatomy

Three‐dimensional (3D) information plays an important part in medical and veterinary education. Appreciating complex 3D spatial relationships requires a strong foundational understanding of anatomy and mental 3D visualization skills. Novel learning resources have been introduced to anatomy training to achieve this. Objective evaluation of their comparative efficacies remains scarce in the literature. This study developed and evaluated the use of a physical model in demonstrating the complex spatial relationships of the equine foot. It was hypothesized that the newly developed physical model would be more effective for students to learn magnetic resonance imaging (MRI) anatomy of the foot than textbooks or computer‐based 3D models. Third year veterinary medicine students were randomly assigned to one of three teaching aid groups (physical model; textbooks; 3D computer model). The comparative efficacies of the three teaching aids were assessed through students' abilities to identify anatomical structures on MR images. Overall mean MRI assessment scores were significantly higher in students utilizing the physical model (86.39%) compared with students using textbooks (62.61%) and the 3D computer model (63.68%) (P < 0.001), with no significant difference between the textbook and 3D computer model groups (P = 0.685). Student feedback was also more positive in the physical model group compared with both the textbook and 3D computer model groups. Our results suggest that physical models may hold a significant advantage over alternative learning resources in enhancing visuospatial and 3D understanding of complex anatomical architecture, and that 3D computer models have significant limitations with regards to 3D learning. Anat Sci Educ 6: 216–224. © 2013 American Association of Anatomists.     

The benefits and limitations of using ultrasonography to supplement anatomical understanding

Anatomical understanding is critical to medical education. With reduced teaching time and limited cadaver availability, it is important to investigate how best to utilize in vivo imaging to supplement anatomical understanding and better prepare medical graduates for the proliferation of point‐of‐care imaging in the future. To investigate whether using short sessions of in vivo imaging using ultrasonography could benefit students' anatomical knowledge and clinical application, we conducted a 2‐hour session on abdominal anatomy using ultrasonography in small groups of five to six students, for both first‐ and second‐year student cohorts. Individual feedback was collected to assess student perceptions. To measure retention and understanding, a short examination containing ultrasound images and questions and performance of a clinical skill (gastrointestinal' tract examination) were assessed. Ultrasonography sessions were highly valued by the students, with 90% of the students reporting their understanding was improved, and over 70% reporting increased confidence in their anatomical knowledge. However, the assessments showed no appreciable impact on skills or understanding related to abdominal anatomy and examination. We conclude that the risk associated with limited exposure increasing confidence without increasing skills remains real and that in vivo imaging is not effective when used as a short adjunct teaching tool. The widespread use of ultrasonography means finding the best way to incorporate ultrasound into medical education remains important. To this end, we are currently implementing an extended program including echocardiography and multiple anatomical sessions that will determine if frequency and repetition of use can positively impact on student performance and understanding. Anat Sci Educ. © 2013 American Association of Anatomists.     

The translucent cadaver: A follow‐up study to gauge the efficacy of implementing changes suggested by students

In a study conducted in 2011, the use of full body digital X‐ray images (Lodox^® Statscan^®) and drawings were described for surface anatomy education during which suggestions were made by students on how to improve the method. Educational innovations should continuously be adjusted and improved to provide the best possible scenario for student learning. This study, therefore, reports on the efficacy of implementing some of these suggestions. Suggestions incorporated into the follow‐up study included: (1) The inclusion of eight strategically placed labeled digital X‐ray images to the dissection halls, (2) The placement of both labeled and unlabeled digital X‐ray images online, (3) The inclusion of informal oral questions on surface anatomy during dissection, (4) The requirement of students to submit individual drawings in addition to group drawings into their portfolios, and (5) Integrating information on how to recognize anatomical structures on X‐rays into gross anatomy lectures given prior to dissection. Students were requested to complete an anonymous questionnaire. The results of the drawings, tests and questionnaires were compared to the results from the 2011 cohort. During 2012, an increased usage of the digital X‐rays and an increase in practical test marks in three out of the four modules (statistically significant only in the cardiovascular module) were reported. More students from the 2012 cohort believed the images enhanced their experience of learning surface anatomy and that its use should be continued in future. The suggested changes, therefore, had a positive effect on surface anatomy education. Anat Sci Educ 6: 433–439. © 2013 American Association of Anatomists.     

Multilayered polyelectrolyte-coated gold nanorods as multifunctional optical contrast agents for cancer cell imaging

We report the application of multilayered polyelectrolyte-coated gold nanorods(GNRs) as multifunctional optical contrast agents for cancer cell imaging.The surface modification of GNRs improves their chemical stability and facilitates them to be taken up by cancer cells through electrostatic interaction.The unique longitudinal surface plasmon resonance property of GNRs makes them suitable as both scattering contrast agents and Raman contrast agents.In our experiments,the staining of GNRs in cells was furthe...     

Application of electrical capacitance tomography for imaging industrial processes

INTRODUCTION In recent years, developments in the technology have led to widespread use of electrical tomography for industrial applications. Electrical tomography i based on the use of an array of the sensors located along the pipe axis or the reactor circumference Images obtained from electrical tomography show th cross-sectional spatial variation of dielectric constan or resistivity. With proper calibration these image depict the distribution of phase density or phas concentration in t…     

基于方位调制的快速分解因子BP算法

BP算法的低效极大地限制了其在大范围场景和实时性要求高的场合下的应用。利用空间上相邻的点存在近似相等的"等效距离"原理,基于已有的两类快速BP算法,提出一种基于方位调制的快速分解因子BP算法。一方面利用基于方位调制的BP算法减少等效合成孔径长度,另一方面利用快速分解因子BP算法减少合成孔径范围内孔径点数。该算法在已有的快速BP算法基础上进一步提高效率,且能够并行实现,在机载实时成像和卫星在轨实时成像方面有一定的应用潜力。仿真和实测数据验证了该算法的有效性。     

Genetically encoded X-ray cellular imaging for nanoscale protein localization

Spatial resolution defines the physical limit of microscopes for probing biomolecular localization and interactions in cells. Whereas synchrotron-based X-ray microscopy (XRM) represents a unique approach for imaging a whole cell with nanoscale resolution due to its intrinsic nanoscale resolution and great penetration ability, existing approaches to label biomolecules rely on the use of exogenous tags that are multi-step and error-prone. Here, we repurpose engineered peroxidases as genetically encoded X-ray-sensitive tags (GXET) for site-specific labeling of protein-of-interest in mammalian cells. We find that 3,3^′-diaminobenzidine (DAB) polymers that are in-situ catalytically formed by fusion-expressed peroxidases are visible under XRM. Using this new tag, we imaged the protein location associated with the alteration of a DNA-methylation pathway with an ultra-high resolution of 30 nanometers. Importantly, the excellent energy resolution of XRM enables multicolor imaging using different peroxidase tags. The development of GXET enlightens the way to nanoscopic imaging for biological studies.     

二次成像法凸透镜移动距离的研究与应用

二次成像法中凸透镜的移动距离是一个重要的参数,分析凸透镜的移动距离与相关变量之间的关系,并举例说明了它的应用。