Effects of temperature and diet on length-weight relationship and condition factor of the juvenile Malabar blood snapper (<Emphasis Type="Italic">Lutjanus malabaricus</Emphasis> Bloch &amp; Schneider, 1801)

In this study we aimed to analyze the effects of water temperature and diet on the length-weight relationship and condition of juvenile Malabar blood snapper Lutjanus malabaricus over a 30-d experimental period. The experiment was conducted in the laboratory using a flow-through-sea-water system. The fish were subjected to four different temperatures (22, 26, 30, and 34 °C) and two diets (commercial pellet and natural shrimp). Fish were fed twice daily. L. malabaricus exhibited negative allometric growth (b<3) at the beginning of the experiment (Day 0) at all temperatures and both diets except for 22 °C fed with shrimp, which showed isometric growth (b=3). Conversely, at the end of the experiment (Day 30) fish showed isometric growth (b=3) at 30 °C fed with the pellet diet, indicating that the shape of the fish did not change with increasing weight and length, and a positive allometric growth (b>3) at 30 °C fed with shrimp diet, which indicated that fish weight increases faster than their length. The rest of the temperatures represented negative allometric growth (b<3) on both diet, meaning that fish became lighter with increasing size. The condition factors in the initial and final measurements were greater than 1, indicating the state of health of the fish, except for those fed on a pellet diet at 34 °C. However, the best condition was obtained at 30 °C on both diets. Nevertheless, diets did not have a significant effect on growth and condition of juvenile L. malabaricus. The data obtained from this study suggested culturing L. malabaricus at 30 °C and feeding on the pellet or shrimp diet, which will optimize the overall production and condition of this commercially important fish species.     

The impact of technology on the enactment of “inquiry” in a technology enthusiast's sixth grade science classroom

This study investigated the impact of the use of computer technology on the enactment of “inquiry” in a sixth grade science classroom. Participants were 42 students (38% female) enrolled in two sections of the classroom and taught by a technology‐enthusiast instructor. Data were collected over the course of 4 months during which several “inquiry” activities were completed, some of which were supported with the use of technology. Non‐participant observation, classroom videotaping, and semi‐structured and critical‐incident interviews were used to collect data. The results indicated that the technology in use worked to restrict rather than promote “inquiry” in the participant classroom. In the presence of computers, group activities became more structured with a focus on sharing tasks and accounting for individual responsibility, and less time was dedicated to group discourse with a marked decrease in critical, meaning‐making discourse. The views and beliefs of teachers and students in relation to their specific contexts moderate the potential of technology in supporting inquiry teaching and learning and should be factored both in teacher training and attempts to integrate technology in science teaching. © 2006 Wiley Periodicals, Inc. J Res Sci Teach     

Does Melatonin Ameliorate Neurological Changes Associated With Alzheimer’s Disease in Ovariectomized Rat Model?

This study aimed to elucidate the mechanisms of melatonin to manage neurological damage in Alzheimer’s disease (AD) induced in ovariectomized rats. Forty adult female rats were enrolled in our study and were classified as; gonad intact control, ovariectomized control group, ovariectomized rats received melatonin, ovariectomized rats injected with AlCl₃ to induce AD and AD-induced rats treated with melatonin. Hydrogen peroxide (H₂O₂), malondialdehyde (MDA), total antioxidant capacity (TAC), superoxide dismutase (SOD), catalase (CAT), B cell lymphoma 2 (Bcl-2), brain derived neurotrophic factor (BDNF), acetylcholinesterase (AchE) and acetylcholine (Ach) were estimated in the brain tissues of the different groups. Treatment of AD-induced rats with melatonin produced marked improvement in the most studied biomarkers which was confirmed by histological investigation of the brain. In Conclusion, melatonin significantly ameliorates the neurodegeneration characteristic of AD in experimental animal model due to its antioxidant, antiapoptotic, neurotrophic and anti-amyloidogenic activities.     

Utilization of discrete transforms to conquer the problems of multi-tone systems

This paper presents a new implementation of discrete multi-tone (DMT) systems based on different discrete transforms that include the discrete sine transform (DST), discrete cosine transform (DCT), and discrete wavelet transform (DWT). The implementation also considers time-domain equalization to mitigate channel distortion. Compared to the fast Fourier transform discrete multi-tone (FFT-DMT) system, the proposed implementations have an advantage in that their energy-compaction property helps in reducing the channel effects. The performance of the DST-DMT, DCT-DMT, DWT-DMT, and FFT-DMT systems, employing a time-domain equalizer (TEQ), is investigated in the paper. It has been demonstrated by computer simulations that the proposed implementations outperform the FFT-DMT system and that the utilization of the TEQ can lead to higher bit rates     

Challenges Faced by Subject Librarians in an Academic Library and Initiatives Toward Overcoming Them: UPM Library Experience

ABSTRACT

Subject Librarians play an important role in an academic library, a role which it is crucial to study. There have been many published studies that have highlighted the lack of evidence on the competencies of Subject Librarians. This paper discusses the challenges faced by the Subject Librarians of the Universiti Putra Malaysia Library. The aim was to gather information from published documents regarding the experiences and practices carried out in efforts to increase the competencies of Subject Librarians. The outcomes from this conceptual paper serve as an important instructional tool for the training and development of Subject Librarians. The results might also provide guidance for the implementation of a similar program or relevant problem-solving plans for other libraries in the region.     

From scientific practice to high school science classrooms: Transfer of scientific technologies and realizations of authentic inquiry

The Biology Workbench (BW) is a web‐based tool enabling scientists to search a wide array of protein and nucleic acid sequence databases with integrated access to a variety of analysis and modeling tools. The present study examined the development of this scientific tool and its consequent adoption into the context of high school science teaching in the form of the Biology Student Workbench (BSW). Participants included scientists, programmers, science educators, and science teachers who played key roles along the pathway of the design and development of BW, and/or the adaptation and implementation of BSW in high school science classrooms. Participants also included four teachers who, with their students, continue to use BSW. Data sources included interviews, classroom observations, and relevant artifacts. Contrary to what often is advocated as a major benefit accruing from the integration of authentic scientific tools into precollege science teaching, classroom enactments of BSW lacked elements of inquiry and were teacher‐centered with prescribed convergent activities. Students mostly were preoccupied with following instructions and a focus on science content. The desired and actual realizations of BSW fell on two extremes that reflected the disparity between scientists' and educators' views on science, inquiry science teaching, and the related roles of technological tools. Research on large‐scale adoptions of technological tools into precollege science classrooms needs to expand beyond its current focus on teacher knowledge, skills, beliefs, and practices to examine the role of the scientists, researchers, and teacher educators who often are involved in such adoptions. © 2010 Wiley Periodicals, Inc. J Res Sci Teach 48: 37–70, 2011     

Influence of explicit and reflective versus implicit inquiry‐oriented instruction on sixth graders' views of nature of science

This study investigated the influence of an explicit and reflective inquiry‐oriented compared with an implicit inquiry‐oriented instructional approach on sixth graders' understandings of nature of science (NOS). The study emphasized the tentative, empirical, inferential, and imaginative and creative NOS. Participants were 62 sixth‐grade students in two intact groups. The intervention or explicit group was engaged in inquiry activities followed by reflective discussions of the target NOS aspects. The comparison or implicit group was engaged in the same inquiry activities. However, these latter activities included no explicit references to or discussion of any NOS aspects. Engagement time was balanced for both groups. An open‐ended questionnaire in conjunction with semistructured interviews was used to assess participants' NOS views before and at the conclusion of the intervention, which spanned 2.5 months. Before the intervention, the majority of participants in both groups held naive views of the target NOS aspects. The views of the implicit group participants were not different at the conclusion of the study. By comparison, substantially more participants in the explicit group articulated more informed views of one or more of the target NOS aspects. Thus, an explicit and reflective inquiry‐oriented approach was more effective than an implicit inquiry‐oriented approach in promoting participants' NOS conceptions. These results do not support the intuitively appealing assumption that students would automatically learn about NOS through engagement in science‐based inquiry activities. Developing informed conceptions of NOS is a cognitive instructional outcome that requires an explicit and reflective instructional approach. © 2002 Wiley Periodicals, Inc. J Res Sci Teach 39: 551–578, 2002     

Teaching elements of nature of science: A yearlong case study of a fourth‐grade teacher

This study examined and supported the efforts of Tina, an experienced elementary teacher, in helping her fourth graders internalize informed views of the inferential, tentative, and creative nature of science (NOS). Tina held informed views of, and was motivated to teach about, NOS. The study aimed to answer the following question: What specific supports were needed to enable Tina to make the target NOS elements explicit in her teaching? The lead researcher visited Tina's classroom every week and interacted with her on a continuous basis. Data sources included classroom observations and videotapes, teacher NOS questionnaires and associated interviews, teacher–researcher communications, and teacher and researcher logs. Although Tina's understandings and intentions were necessary to enable her to teach about NOS, they were not sufficient. Tina needed support to translate her NOS views and intentions into pedagogically appropriate instructional activities that would make the target NOS aspects accessible to her students. Socially mediated support was needed at the personal level in terms of helping Tina activate her tacit NOS understandings, and at the professional level in terms of modeling explicit NOS instruction in Tina's own classroom by the lead researcher. © 2003 Wiley Periodicals, Inc. J Res Sci Teach 40: 1025–1049, 2003