648 research outputs found

    AN INVESTIGATION OF THE EFFECTIVENESS OF GESTURES TO ENHANCE CONCEPT RETENTION IN CHEMISTRY INSTRUCTION

    Get PDF
    The emergence of embodied cognition as a theory of learning has placed new emphasis on the interdependent relationship between what the mind perceives and what the body experiences. Movement and objects in the physical environment take on significant roles in the process of learning within this view and the role of gesturing in cognition has become increasingly interesting. Significant research suggests that the physical process of gesturing is connected to how the mind processes information. Gesturing during the recall of information is a universally known phenomena and one that seems to aid in the process of recall. More recent findings have suggested that the use of gestures may play a helpful role in assisting learners with processing information and particularly with retaining information longer. This study investigates this claim by using intentional gestures at the time of encoding new information to assist a group of first year chemistry students in high school process how to identify and label Lewis acids and bases in reaction schemes. A treatment group received an intervention lesson where key concepts were instantiated with the use of related gestures while the control group received the same lesson without the use of gestures. The intervention lesson involved students using BeSocratic, a web-based, interactive system currently under development. Performance was assessed with a pre-post test and a delayed post-test administered three weeks after the intervention to determine if the treatment group would retain the concepts significantly better than the control group. The results showed that two groups of students with similar backgrounds in the material exhibited similar gains in information from the intervention lesson. However, when given the same assessment three weeks later, the group of students who had received the gesture enhanced lesson significantly outperformed those students who did not. The gains were limited to questions most directly linked to the gestures. The results are part of a small but growing body of evidence that suggests that the use of gestures during the encoding of new information does offer a tool to help learners retain information

    Backwater controls of avulsion location on deltas

    Get PDF
    River delta complexes are built in part through repeated river-channel avulsions, which often occur about a persistent spatial node creating delta lobes that form a fan-like morphology. Predicting the location of avulsions is poorly understood, but it is essential for wetland restoration, hazard mitigation, reservoir characterization, and delta morphodynamics. Following previous work, we show that the upstream distance from the river mouth where avulsions occur is coincident with the backwater length, i.e., the upstream extent of river flow that is affected by hydrodynamic processes in the receiving basin. To explain this observation we formulate a fluvial morphodynamic model that is coupled to an offshore spreading river plume and subject it to a range of river discharges. Results show that avulsion is less likely in the downstream portion of the backwater zone because, during high-flow events, the water surface is drawn down near the river mouth to match that of the offshore plume, resulting in river-bed scour and a reduced likelihood of overbank flow. Furthermore, during low-discharge events, flow deceleration near the upstream extent of backwater causes enhanced deposition locally and a reduced channel-fill timescale there. Both mechanisms favor preferential avulsion in the upstream part of the backwater zone. These dynamics are fundamentally due to variable river discharges and a coupled offshore river plume, with implications for predicting delta response to climate and sea level change, and fluvio-deltaic stratigraphy

    High-Density Suspensions Formed Under Waves

    Get PDF
    We performed a series of laboratory experiments to investigate the interactions of a turbulent wave boundary layer with a predominantly silt-size sediment bed. Quasi-steady, turbulent, high-density suspensions (HDS) formed over a wide range of wave conditions and had near-bed (~1 mm above bed) concentrations ranging from 17 to 81 g/l scaling roughly with the wave orbital velocity. HDS were defined by the presence of a lutocline, an abrupt change in vertical concentration gradient. Despite the initial bed being 70% silt and 20% sand, HDS had significant near-bed sand fractions ranging from 27 to 78%. Winnowing of the bed caused more concentrated HDS to be coarser grained, which in turn caused the suspensions to be thinner because of the greater settling velocity of the sediment. Our experiments are consistent with a dynamic feedback model where suspended sediment is limited through sediment-induced stratification expressed with a bulk Richardson number. However, our computed values of the bulk Richardson number converge to a value that is an order of magnitude less than the critical value of 0.25 that is typically assumed. The experimental wave orbital velocities (15–60 cm/s) and periods (3–8 s), as well as the characteristics of the HDS and the bed in our experiments, were comparable to observations made on the Eel shelf, California, during storm conditions when fluid mud has been observed

    Ad libitum suckling by a foster calf in the presence or absence of the cow\u27s own calf prolongs postpartum anestrus to first ovarian cycle

    Get PDF
    Five treatments were initiated approximately 15 days after calving: 1) calf was weaned from its dam (CW); 2) calf was present continually with its own dam (CP-O); 3) calf was present continually with its own dam but contact with the udder was restricted (CR); 4) foster calf was pre sent continually but the cow\u27s own calf was absent (CP-F); and 5) foster calf was present continually, and the dam\u27s own calf was present but restricted (CR+F). Cows weaned at 15 days (CW) cycled in about 2 weeks, whereas cows in the CR treatment cycled 1 week later, and cows in the CP-O treatment did not cycle for about 5 weeks. Cows fostering calves in the presence (CR+F) or absence (CP-F) of their own calves had extended anestrus periods similar to those in cows nursing their own calve s (CP-O). If a cow bonds with a foster calf (as in the CP-F treatment), then the duration of anestrus is lengthened. We conclude that anestrus is prolonged only when milk is removed by a calf (her own or a foster calf) to which the cow is bonded

    The Use Of Statistical Sampling And A Single-Point Estimator To Establish Punitive Fines In Compliance Auditing: A Cautionary Note

    Get PDF
    This paper describes current practices relating to statistical sampling used by auditors performing compliance audits.  An example audit case is presented where a compliance audit is performed using statistical sampling.  Fines for non-compliance are based upon the sample results.  While the practice is quite common and generally accepted, there are significant ramifications associated with the use of a single-point estimator.  Approximately half of the time, an auditee will be charged more than is actually deserved.  We explore the shortcomings associated with the use of a single-point estimator and the appropriateness of the use of a one-tailed confidence interval to provide greater assurance that fines are appropriate and reasonable

    Effective Use of Case Studies in the MIS Capstone Course through Semi-Formal Collaborative Teaching

    Get PDF
    This paper provides the theoretical grounding for the development of an instrument to assess the effectiveness of the case study approach in teaching the higher-level concepts associated with the MIS capstone course. The instrument was administered to students in the capstone class over three semesters. The resulting findings from the survey, combined with an understanding of each instructor’s approach to teaching case studies are then used collaboratively by the instructors as a means to identify strengths and areas for improvement. Items in the survey were developed from applicable prior research on teaching and learning and collaborative teaching. Responses to the survey items were subjected to an exploratory factor analysis, resulting in two dimensions of interest – teaching substance and teaching technique. The results of the survey indicate widespread satisfaction by students with the case study approach

    Presynchronizing PGF2α and GnRH injections before timed artificial insemination CO-Synch + CIDR program

    Get PDF
    Fixed-time artificial insemination is an effective management tool that reduces the labor associated with more conventional artificial insemination programs requiring detection of estrus. The 7-day CO-Synch + controlled internal drug release (CIDR) insert protocol has been shown to effectively initiate estrus and ovulation in cycling and non-cycling suckled beef cows, producing pregnancy rates at or greater than 50% in beef cows. The gonadotropin-releasing hormone (GnRH) injection that begins the CO-Synch + CIDR program initiates ovulation in a large proportion of cows, particularly anestrous cows. The CIDR, which releases progesterone intravaginally, prevents short estrous cycles that usually follow the first postpartum ovulation in beef cows. Our hypothesis was that inducing estrus with a prostaglandin injection followed 3 days later with a GnRH injection, 7 days before applying the 7-day CO-Synch + CIDR protocol, might increase the percentage of cycling cows that would exhibit synchronous follicular waves after the onset of the CO-Synch + CIDR protocol. We also hypothesized that the additional GnRH injection would increase the percentage of anestrous cows that would ovulate, thereby increasing pregnancy outcomes

    Fixed-time inseminaton of suckled beef cows. 2. Cosynch and progesterone

    Get PDF
    The Cosynch protocol (GnRH 7 days before and again 48 h after PGF2 with AI at the second GnRH injection) produced pregnancy rates in suckled beef cows that exceeded 50% without heat detection and with only three handlings of all cows. The addition of an intravaginal progesterone insert to the Cosynch protocol improved pregnancy rates in two of the three breeds of cows studied
    • …
    corecore