Systematic Influences on Teaching Evaluations : The Case for Caution

The evaluation of teaching and learning has become an important activity in tertiary education institutions. Student surveys provide information about student perceptions and judgments of a particular subject. However, as is widely recognised, the appropriate interpretation of this data is problematic. There is a large literature, mainly for the US, on the use and usefulness of student subject evaluations. This literature has highlighted a number of ‘mitigating factors’ such as subject difficulty, discipline area, etc., that should be taken into account in interpreting the results of these questionnaires. In this paper we examine 8 years of QOT responses from an Economics Department in an Australian University which accounted for more than 79,000 student subject enrolments in 565 subjects. The purpose of this analysis is to establish how the information contained in these data can be used to interpret the responses. In particular, we determine to what extent other factors besides the instructor in charge of the subject have an impact on the raw average student evaluation scores. We find that the following characteristics of the students in these classes had an influence on the average QOT score: year level, enrolment size, the quantitative nature of the subject, the country of origin of the students, the proportion that are female, Honours status of the student, the differential in their mark from previous marks, quality of workbook, quality of textbook and the relative QOT score versus other subjects taught at the same time. However, a number of other factors proposed in the literature to be important influences were found not to be. These include the student’s fee paying status, whether they attended a public, private or catholic secondary school, which other faculty within the University they came from, and if the subject was taught in multiple sessions.

A Bose-Einstein condensate in a random potential

An optical speckle potential is used to investigate the static and dynamic properties of a Bose-Einstein condensate in the presence of disorder. For strong disorder the condensate is localized in the deep wells of the potential. With smaller levels of disorder, stripes are observed in the expanded density profile and strong damping of dipole and quadrupole oscillations is seen. Uncorrelated frequency shifts of the two modes are measured for a weak disorder and are explained using a sum-rules approach and by the numerical solution of the Gross-Pitaevskii equation

Amplified fragment length polymorphisms (AFLPs) analysis of species of Solanum section Solanum (Solanaceae) from Uganda

The taxonomy of species belonging to Solanum section Solanum (sometimes referred to as the Solanum nigrum complex or black nightshades) is known to be difficult and has resulted in extensive synonymy. Yet, these species play a significant role in nutrition and food security, especially in developing countries. The amplified fragment length polymorphisms (AFLPs) technique was used to assess the genetic relationships among 107 accessions representing eight species of the section Solanum and to obtain new insight into the taxonomic status of the S. nigrum complex. Four primer combinations yielded 510 AFLP bands, only 29 of which were monomorphic. Neighbor-joining and principal coordinates analyses were performed. The AFLP data only partially correlated with earlier classifications based on morphology. We have been able to confirm the presence of only 5 out of eight species of this complex previously recognized from Uganda, that is, Solanum americanum, Solanum scabrum, Solanum hirsutum, Solanum florulentum/Solanum tarderemotum and Solanum villosum. In addition, S. villosum did not separate in accordance with previous subspecific ranks. It is likely that neither Solanum grossidentatum, S. nigrum nor Solanum sarrachoides occurred in Uganda. Also, there was no correlation between geographic localities for the Ugandan material and the AFLP results, indicating that most of the studied species are introduced.Key words: Amplified fragment length polymorphisms (AFLPs), Solanum nigum complex, Africa, genetic variation, taxonomy, Uganda

Effect of optical disorder and single defects on the expansion of a Bose-Einstein condensate in a one-dimensional waveguide

We investigate the one-dimensional expansion of a Bose-Einstein condensate in an optical guide in the presence of a random potential created with optical speckles. With the speckle the expansion of the condensate is strongly inhibited. A detailed investigation has been carried out varying the experimental conditions and checking the expansion when a single optical defect is present. The experimental results are in good agreement with numerical calculations based on the Gross-Pitaevskii equation.Comment: 5 pages, 5 figure

An evidence map of the effect of Tai Chi on health outcomes.

BackgroundThis evidence map describes the volume and focus of Tai Chi research reporting health outcomes. Originally developed as a martial art, Tai Chi is typically taught as a series of slow, low-impact movements that integrate the breath, mind, and physical activity to achieve greater awareness and a sense of well-being.MethodsThe evidence map is based on a systematic review of systematic reviews. We searched 11 electronic databases from inception to February 2014, screened reviews of reviews, and consulted with topic experts. We used a bubble plot to graphically display clinical topics, literature size, number of reviews, and a broad estimate of effectiveness.ResultsThe map is based on 107 systematic reviews. Two thirds of the reviews were published in the last five years. The topics with the largest number of published randomized controlled trials (RCTs) were general health benefits (51 RCTs), psychological well-being (37 RCTs), interventions for older adults (31 RCTs), balance (27 RCTs), hypertension (18 RCTs), fall prevention (15 RCTs), and cognitive performance (11 RCTs). The map identified a number of areas with evidence of a potentially positive treatment effect on patient outcomes, including Tai Chi for hypertension, fall prevention outside of institutions, cognitive performance, osteoarthritis, depression, chronic obstructive pulmonary disease, pain, balance confidence, and muscle strength. However, identified reviews cautioned that firm conclusions cannot be drawn due to methodological limitations in the original studies and/or an insufficient number of existing research studies.ConclusionsTai Chi has been applied in diverse clinical areas, and for a number of these, systematic reviews have indicated promising results. The evidence map provides a visual overview of Tai Chi research volume and content.Systematic review registrationPROSPERO CRD42014009907

ENV-653: PRODUCTION OF BIOSURFACTANT BY RHODOCOCCUS ERYTHROPOLIS SP. CULTIVATED IN A NOVEL FISH WASTE COMPOST EXTRACT SUBSTRATE

Compost generated through fish waste composting could provide an effective source of nutrient-rich organic matter for microbial growth, leading to the production of valuable products such as biosurfactants. Existing biosurfactant production is a relative expensive process and raw materials contribute about 30% of the production cost. Utilizing waste streams such as fish waste compost (FWC) as a substrate is an economically viable alternative. In this study, biosurfactant was produced by Rhodococcus erythropolis sp. P6-4P, a strain isolated from the North Atlantic Ocean. Biosurfactant production with FWC extract was compared with other soluble and insoluble carbon and nitrogen sources using emulsification assay and surface tension measurement. FWC extract showed good potential as an unconventional source of nutrient for microbial growth. The produced biosurfactant under optimum condition obtained via response surface methodology was further characterized for total carbohydrate, total lipid and total protein content. The results provided evidence for using FWC extract as a novel substrate for biosurfactant production

Ultra scale-down approaches to enhance the creation of bioprocesses at scale: impacts of process shear stress and early recovery stages

The sensitivity of biological materials to shear stress conditions encountered during large-scale bioprocessing makes successful scale up from the bench challenging. Ultra scale-down technologies seek to use just millilitre quantities to enhance our understanding of the impact of the process environment as a basis for process optimisation. They can help speed translation of new biological discoveries to market and reduce risks encountered in scale up. They are important both as process discovery tools and as preparative tools to yield material for study of subsequent stages. In this review the focus is on the early recovery stages post fermentation or cell culture and in particular the use of continuous-flow and dead-end centrifugation integrated with preparative stages (e.g. flocculation) and subsequent depth filtration. Examples range from therapeutic antibodies, to rationally engineered (synthetic biology) host strains, to stem cells for therapy

Unstable regimes for a Bose-Einstein condensate in an optical lattice

We report on the experimental characterization of energetic and dynamical instability, two mechanisms responsible for the breakdown of Bloch waves in a Bose-Einstein condensate interacting with a 1D optical lattice. A clear separation of these two regimes is obtained performing measurements at different temperatures of the atomic sample. The timescales of the two processes have been determined by measuring the losses induced in the condensate. A simple phenomenological model is introduced for energetic instability while a full comparison is made between the experiment and the 3D Gross-Pitaevskii theory that accounts for dynamical instability

Observation of dynamical instability for a Bose-Einstein condensate in a moving 1D optical lattice

We have experimentally studied the unstable dynamics of a harmonically trapped Bose-Einstein condensate loaded into a 1D moving optical lattice. The lifetime of the condensate in such a potential exhibits a dramatic dependence on the quasimomentum state. This is unambiguously attributed to the onset of dynamical instability, after a comparison with the predictions of the Gross-Pitaevskii theory. Deeply in the unstable region we observe the rapid appearance of complex structures in the atomic density profile, as a consequence of the condensate phase uniformity breakdown

Minimally-destructive detection of magnetically-trapped atoms using frequency-synthesised light

We present a technique for atomic density measurements by the off-resonant phase-shift induced on a two-frequency, coherently-synthesised light beam. We have used this scheme to measure the column density of a magnetically trapped atom cloud and to monitor oscillations of the cloud in real time by making over a hundred non-destructive local density measurments. For measurements using pulses of 10,000-100,000 photons lasting ~10 microsecond, the precision is limited by statistics of the photons and the photodiode avalanche. We explore the relationship between measurement precision and the unwanted loss of atoms from the trap and introduce a figure of merit that characterises it. This method can be used to probe the density of a BEC with minimal disturbance of its phase.Comment: Submitted to New Journal of Physic