Intensity of parasitic infestation in silver carp, Hypophthalmichthys molitrix

Silver carp, Hypopthalmichthys molitrix is one of the most economically valuable fish species in Bangladesh. However, its production is often hindered by parasite-induced mortality. The present study reports the intensity of parasitic infestation in 216 specimens of H. molitrix collected from different fish markets in Rajshahi City, Bangladesh. Nine different parasite species (Trichodina pediculatus, Dactylogyrus vastator, Ichthyophthirius multifilis, Gyrodactylus elegans, Lernaea sp., Apiosoma sp., Myxobolus rohitae, Camallanus ophiocephali, and Pallisentis ophiocephali) were recovered from the gill, skin, stomach, and intestine of host fish. The highest level of infection was observed for host skin, while lower levels were observed for host gill, stomach, and intestine. The results also revealed that the intensity of parasite infection in different organs of H. molitrix varied with the season. In particular, the highest levels of infection were recorded during the winter period (November-February), when fish are most susceptible to parasites. The findings of the study will help in the management and conservation of H. molitrix.     

Relationships of attitude toward classroom environment with attitude toward and achievement in science among tenth grade biology students

The purpose of the study was to examine the relationship of classroom environment to attitudes toward science and achievement in science among tenth grade biology students. An attitude instrument was administered at three times during the school year to measure student attitudes toward science and the classroom environment. The classroom environment measures examined six areas: emotional climate of the science classroom, science curriculum, physical environment of the science classroom, science teacher, other students in the science classroom, and friends attitudes toward science. Student achievement in science was measured by teacher reported semester grades. The results of the study indicated: (1) student attitudes toward the classroom environment predicted between 56 to 61% of the variance in attitudes toward science, (2) student attitudes toward the classroom environment predicted between 5 to 14% of the variance in achievement in science, (3) student attitudes toward science and attitudes toward the classroom environment predicted between 8 and 18% of the variance in achievement in science.     

Effects of manipulating relative and absolute motion information during observational learning of an aiming task.

In the visual perception perspective of observational learning, the manipulation of relative and absolute motion information in visual demonstrations optimally directs learners' search towards appropriate task solutions. We assessed the effect of emphasizing transformational information and removal of structural information using point-light kinematic displays in approximating the model's relative motion patterns. Participants viewed computer-simulated point-light demonstrations or normal video demonstrations before and intermittently throughout 100 acquisition trials with knowledge of results on an underarm modified-dart aiming task. On the next day, all participants performed 20 retention trials without demonstrations. The kinematics of spatial and temporal coordination and control variables were examined relative to the model's action, as well as performance scores. The results indicated that approximation of the model's spatial and temporal coordination and control patterns was achieved after observation of either type of demonstrations. No differences were found in movement outcomes. In a second experiment, the effects of manipulating absolute motion information by slow-motion demonstrations were examined relative to real-time demonstrations. Real-time demonstrations led to a closer approximation to the model's spatial and temporal coordination patterns and better outcome scores, contradicting predictions that slow-motion displays convey intact relative motion information. We speculate that the effect of visual demonstration speed on action perception and reproduction is a function of task constraints--that is, novelty or familiarity of relative motion of demonstrated activities.     

The Reading–Spelling Connection: Developing and Evaluating a Beginning Spelling Intervention for Children at Risk of Reading Disability

Abstract In this article, we describe the development and evaluation of a beginning spelling intervention for young children at risk of reading disability. We first summarize the literature that supports beginning spelling as an ideal method for strategically integrating the beginning reading big ideas of phonemic awareness and alphabetic understanding. We then summarize the literature on effective instructional principles for students at risk of reading disability. Next, we describe how instructional design was applied to the development of an intervention for young children at risk of reading disability, then summarize the findings of an experimental study supporting the effectiveness of this intervention. Finally, we provide selected examples from the spelling intervention to illustrate the findings' translation into instructional practice.     

Examining the specificity of practice hypothesis: is learning modality specific?

The specificity of practice hypothesis was examined using a tracking task. In Experiment 1, visual or auditory feedback about performance was provided. Vision was more useful than audition early in acquisition. Performance gains found in acquisition were maintained during retention, but learning was specific only if the acquisition modality was visual. Specificity did not increase with the amount of practice. In Experiment 2, visual and auditory information were combined. Again, the specificity of practice hypothesis was supported. Also, instructing participants to attend to one information source allowed us to demonstrate that information can be explicitly or implicitly processed. Further, specificity effects may occur because of different rates of development for error detection and correction processes.     

A simultaneous model of nonprofit symphony orchestra behavior

In this paper, we test a six equation simultaneous model of nonprofit symphony orchestra behavior. The model is based on Hansmann's theory of nonprofit behavior in the performing arts. The results show that the most prestigious of the orchestras practise a pricing policy that encourages patrons to make a tax deductible contribution. In this manner, they achieve a pattern of price discrimination that, instead of increasing revenues, reduces revenues. Following conditions suggested by Hansmann, we are also able to draw conclusions about the objectives of nonprofit symphony orchestras.     

A Conceptual Framework for a Psychometric Theory for Standard Setting with Examples of Its Use for Evaluating the Functioning of Two Standard Setting Methods

A conceptual framework is proposed for a psychometric theory of standard setting. The framework suggests that participants in a standard setting process (panelists) develop an internal, intended standard as a result of training and the participant's background. The goal of a standard setting process is to convert panelists' intended standards to points on a test's score scale. Psychometrics is involved in this process because the points on the score scale are estimated from ratings provided by participants. The conceptual framework is used to derive three criteria for evaluating standard setting processes. The use of these criteria is demonstrated by applying them to variations of bookmark and modified Angoff standard setting methods.