Students' Recognition of Concepts of Reflection and Refraction in Multiple Representational Formats

A complete understanding of reflection and refraction is achieved when students can recognize the concepts in different representations such as verbal, mathematical, and ray diagrams. The study explores the inconsistencies and difficulties in the students' understanding of image formation by mirrors and lenses. The primary researcher analyzed data on students' performance on a 20-item test consisting of verbal, mathematical, and ray diagram representation items. Two hundred thirty-one (231) grade 10 students took the test after 52-hour instructions on light reflection and refraction. The test results reveal a recognition of the concepts of image formation better in verbal representation by the students. In addition, chi-square results implied that students had drawn the rays in their ray diagrams of spherical mirrors based on their equivalent understanding of the situation in verbal representation. Inconsistencies in their knowledge of reflection by mirrors and refraction by lenses were identified by the differences in the students' responses to verbal and ray diagram representations and supported by the number of students who correctly answered the same items in these two representations. Inconsistencies with the mirror or lens equation were also determined by comparing the results of the items in mathematical representation. Students are found to have difficulties applying the mirror or lens equation and ray-tracing method in problem situations. These observed inconsistencies and problems in multiple representations imply that students have a poor and incomplete understanding of the topic under study

The Dynamics of Boundary Objects, Social Infastructures and Social Identities

This paper takes a dynamic approach to understanding the nature and role of boundary objects by examining them in relation to the social infrastructures within which they are embedded and to the social identities of the groups that share them. We present a case study that describes the introduction of 3D modelling technologies into the AEC industry and the changes that consequently occurred. Based on the case study we suggest that boundary objects are used not only as a translation device, but also as a resource to form and express social identities. We further suggest the occurrence of a dynamic process whereby changes in boundary objects enable changes in social infrastructures and social identities in one group. These changes, in turn, create the conditions for change in bordering groups through shared boundary objects and boundary practices

ResQbot: a mobile rescue robot with immersive teleperception for casualty extraction

In this work, we propose a novel mobile rescue robot equipped with an immersive stereoscopic teleperception and a teleoperation control. This robot is designed with the capability to perform safely a casualty-extraction procedure. We have built a proof-of-concept mobile rescue robot called ResQbot for the experimental platform. An approach called “loco-manipulation” is used to perform the casualty-extraction procedure using the platform. The performance of this robot is evaluated in terms of task accomplishment and safety by conducting a mock rescue experiment. We use a custom-made human-sized dummy that has been sensorised to be used as the casualty. In terms of safety, we observe several parameters during the experiment including impact force, acceleration, speed and displacement of the dummy’s head. We also compare the performance of the proposed immersive stereoscopic teleperception to conventional monocular teleperception. The results of the experiments show that the observed safety parameters are below key safety thresholds which could possibly lead to head or neck injuries. Moreover, the teleperception comparison results demonstrate an improvement in task-accomplishment performance when the operator is using the immersive teleperception

Demographic Characteristics of Academic Advisors for Intercollegiate Athletics of NCAA D-I Member Institutions

This investigation examined selected demographic factors of National Association of Academic Advisors for Atlhetics (N4A) professionals. A 23 item self-reported questionnaire was mailed in Spring 2001. A non-experimental descriptive exploratory design was implemented utilizing the field survey format. Research variables investigated were individual primary & secondary diversity characteristics. Primary diversity characteristics refer to human differences that are inborn and cannot be changed or modified during a person's life such as age, race, ethnicity, gender, physical abilities, and sexual orientation (Gardenswartz & Rowe, 1994). Secondary diversity characteristics are human differences that are inherited from the environment and can be changed or modified during a person's life such as educational level, work experience, income, marital status, religious beliefs, geographical location, parental status, behavioral style, etc. (Loden & Rosener, 1991). The responses from 213 questionnaires were coded and included in the SPSS computer analysis. Not all participants responded to all items; as a result, the sample sub-totals varied from 202-213. Results indicated 2/3 (67.4%) of advisors were likely to be 39 years or less in age and 113 (32.6%) were 40 years or older. Cross-tabulations implied male and female advisors were likely to have earned degrees at the same levels. White females were more often employed as academic athletic advisors in NCAA D-1 institutions than male or females of other ethnic minority groups collectively. Gender results from 212 responses indicated 83 (39.3%) were males and 129 (60.7%) were females. The average age of the respondents was 36.9 years and they ranged in age from 23 to 66 years (median age 34; mode age 29). Annual mean salaries of the advisors were $40,956 and ranged from$18,000 to $96,000 (median salary$39,000, mode $30,000). The average salary for the male advisors was 8.45$6,804 higher han the average salary for the female advisors. A similar trend was also shown for salary. The median salary for male advisors was $42,000 and$36,000 for female advisors. The difference in salary depicted an 8.57% or $6,000 increase for the males than female

Encapsulation of pentacene/C₆₀ organic solar cells with Al₂O₃ deposited by atomic layer deposition

© 2007 American Institute of Physics. The electronic version of this article is the complete one and can be found at: http://dx.doi.org/10.1063/1.2751108DOI: 10.1063/1.2751108Organic solar cells based on pentacene/C₆₀ heterojunctions were encapsulated using a 200-nm-thick film of Al₂O₃ deposited by atomic layer deposition (ALD). Encapsulated devices maintained power conversion efficiency after exposure to ambient atmosphere for over 6000 h, while devices with no encapsulation degraded rapidly after only 10 h of air exposure. In addition, thermal annealing associated with the ALD deposition is shown to improve the open-circuit voltage and power conversion efficiency of the solar cells

Hernioplastia inguinal segundo procedimento de Stoppa: drenar ou não drenar

OBJETIVO: O objetivo do presente estudo é avaliar os benefícios da drenagem no procedimento de Stoppa no tratamento da hérnia inguinal. PACIENTES E MÉTODOS: O uso da drenagem de aspiração contínua foi randomizado ao final do procedimento cirúrgico em 26 pacientes submetidos à correção da hérnia inguinal e divididos em dois grupos: Grupo A, com 12 pacientes submetidos à drenagem e Grupo B, com 14 pacientes não submetidos à drenagem. No segundo dia de pós-operatório, todos os pacientes foram submetidos à tomografia computadorizada de abdome para a verificação de coleções abdominais. RESULTADOS: No Grupo A, nenhum paciente apresentou coleção no espaço pré-peritonial. Por outro lado, um paciente desenvolveu abcesso no espaço pré-peritonial no décimo quinto dia de pós-operatório. No Grupo B, 12 pacientes apresentaram coleção pré-peritonial à tomografia. Entretanto, somente três apresentaram complicações menores. Nenhum paciente apresentou complicação maior. CONCLUSÃO: O uso de drenagem de aspiração contínua no procedimento de Stoppa não traz nenhum benefício.OBJECTIVE: The objective of this study is to evaluate the benefits of drainage in the Stoppa procedure for inguinal repair. PATIENTS AND METHODS: The use of a suction drain was randomized at the end of the surgical intervention in 26 male patients undergoing inguinal hernia repair, divided into 2 groups: Group A, 12 patients undergoing drainage, and group B, 14 patients not undergoing drainage. On the second postoperative day, all patients underwent abdominal pelvic computed tomography scan examination to detect the presence of abdominal fluid collection. RESULTS: In group A, no patient developed fluid collection in the preperitoneal space, and 1 patient presented with an abscess in the preperitoneal space on the 15th postoperative day. In group B, 12 patients presented with fluid collections in the preperitoneal space on computed tomography scan evaluation. However, only 3 patients presented minor complications. None of the patients developed a major complication. CONCLUSION: The use of suction drainage with the Stoppa procedure does not provide any benefit

Mitogen Kinase Kinase (MKK7) Controls Cytokine Production In Vitro and In Vivo in Mice

Mitogen kinase kinase 4 (MKK4) and mitogen kinase kinase 7 (MKK7) are members of the MAP2K family that can activate downstream mitogen-activated protein kinases (MAPKs). MKK4 has been implicated in the activation of both c-Jun N-terminal kinase (JNK) and p38 MAPK, while MKK7 has been reported to activate only JNK in response to different stimuli. The stimuli, as well as the cell type determine which MAP2K member will mediate a given response. In various cell types, MKK7 contributes to the activation of downstream MAPKs, JNK, which is known to regulate essential cellular processes, such as cell death, differentiation, stress response, and cytokine secretion. Previous studies have also implicated the role of MKK7 in stress signaling pathways and cytokine production. However, little is known about the degree to which MKK4 and MKK7 contribute to innate immune responses in macrophages or during inflammation in vivo. To address this question and to elucidate the role of MKK4 and MKK7 in macrophage and in vivo, we developed MKK4- and MKK7-deficient mouse models with tamoxifen-inducible Rosa26 Cre(ERT). This study reports that MKK7 is required for JNK activation both in vitro and in vivo. Additionally, we demonstrated that MKK7 in macrophages is necessary for lipopolysaccharide (LPS)-induced cytokine production, M1 polarization, and migration, which appear to be a major contributor to the inflammatory response in vivo. Conversely, MKK4 plays a significant, but minor role in cytokine production in vivo

Finite element modeling and in vivo analysis of electrode configurations for selective stimulation of pudendal afferent fibers

<p>Abstract</p> <p>Background</p> <p>Intraurethral electrical stimulation (IES) of pudendal afferent nerve fibers can evoke both excitatory and inhibitory bladder reflexes in cats. These pudendovesical reflexes are a potential substrate for restoring bladder function in persons with spinal cord injury or other neurological disorders. However, the complex distribution of pudendal afferent fibers along the lower urinary tract presents a challenge when trying to determine the optimal geometry and position of IES electrodes for evoking these reflexes. This study aimed to determine the optimal intraurethral electrode configuration(s) and locations for selectively activating targeted pudendal afferents to aid future preclinical and clinical investigations.</p> <p>Methods</p> <p>A finite element model (FEM) of the male cat urethra and surrounding structures was generated to simulate IES with a variety of electrode configurations and locations. The activating functions (AFs) along pudendal afferent branches innervating the cat urethra were determined. Additionally, the thresholds for activation of pudendal afferent branches were measured in α-chloralose anesthetized cats.</p> <p>Results</p> <p>Maximum AFs evoked by intraurethral stimulation in the FEM and in vivo threshold intensities were dependent on stimulation location and electrode configuration.</p> <p>Conclusions</p> <p>A ring electrode configuration is ideal for IES. Stimulation near the urethral meatus or prostate can activate the pudendal afferent fibers at the lowest intensities, and allowed selective activation of the dorsal penile nerve or cranial sensory nerve, respectively. Electrode location was a more important factor than electrode configuration for determining stimulation threshold intensity and nerve selectivity.</p

A cross validation of Consumer-Based Brand Equity (CBBE) with Private Labels in Spain

Molinillo,S., Ekinci, Y., Japutra, A. (2014)'A cross validation of Consumer-Based Brand Equity (CBBE) with Private Labels in Spain'. in Martínez-López, Gázquez-Abad, J.C. and Sethuraman, R. J.A. (eds.) Advances in National Brand and Private Label Marketing. Second International Conference, 2015. Springer Proceedings in Business and Economics, pp. 113-125In recent years a number of Consumer-Based Brand Equity (CBBE) models and measurement scales have been introduced in the branding literature. However, examinations of brand equity in Private Labels (PL) are rather limited. This study aims to compare the validity of the two prominent CBBE models those introduced by Yoo and Donthu (2001) and Nam et al. (2011). In order to test the models and make this comparison, the study collected data from 236 respondents who rated private labels in Spain. A list of 30 different fashion and sportswear PL was introduced to respondents. These brands do not make any reference to the retail store in which they are sold. Research findings suggest that the extended CBBE model introduced by Nam et al. (2011) and Ciftci et al. (2014) is more reliable and valid than Yoo and Donthu’s model for assessing PL. Theoretical contributions and managerial implications are discussed.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Block-Diagonalization and f-electron Effects in Tight-Binding Theory

We extend a tight-binding total energy method to include f-electrons, and apply it to the study of the structural and elastic properties of a range of elements from Be to U. We find that the tight-binding parameters are as accurate and transferable for f-electron systems as they are for d-electron systems. In both cases we have found it essential to take great care in constraining the fitting procedure by using a block-diagonalization procedure, which we describe in detail.Comment: 9 pages, 6 figure