225 research outputs found

    Using peer tutors to improve the legal writing skills of first-year law students at University of KwaZulu-Natal, Howard College School of Law

    Get PDF
    Over the past few decades, the University of KwaZulu-Natal’s Howard College School of Law (UKZN School of Law) has paid considerable attention to improving the legal writing skills of its first-year law (LLB) students. In its quest to improve these skills, the School of Law has implemented a number of writing interventions, which have focussed on finding a creative solution to the problem of balancing the need for time-intensive student support and the lack of staff capacity to provide it. This article argues that one such solution could be to use senior Law School students acting in the capacity of peer writing tutors. The article begins by discussing the concept of using peer tutors to teach persuasive legal writing to first-year LLB students within the context of a collaborative andsocial constructivist teaching and learning paradigm. It proceeds to discuss the substantial benefits of using senior law students as peer tutors and the training that must be provided to them. This tutor training is essential, since many of the peer tutors, despite being senior law students, lack experience in teaching persuasive writing and therefore must still develop these skills. Thus, the article explores the significance of the training aspect of using senior law students to tutor persuasive writing to first-year law students, including the theoretical underpinnings of this training as well as its practical application. In this discussion, two models of peer tutor development are examined – “participatory peer-tutor development” and “peer-tutor development sequencing” – before discussing the practical (and necessary) application of both of these models in the module Teaching Legal Skills (“TLS”) at the UKZN School of Law. Finally, the article makes recommendations that could inform the design of a viable, cost-effective, energy- efficient future legal writing programme, and suggests possible ways of overcoming or avoiding the challenges identified

    Comparing [C II], H I, and CO dynamics of nearby galaxies

    No full text
    The HI and CO components of the interstellar medium (ISM) are usually used to derive the dynamical mass M-dyn of nearby galaxies. Both components become too faint to be used as a tracer in observations of high-redshift galaxies. In those cases, the 158 mu m line of atomic carbon ([CII]) may be the only way to derive M-dyn. As the distribution and kinematics of the ISM tracer affects the determination of M-dyn, it is important to quantify the relative distributions of HI, CO, and [CII]. HI and CO are well-characterized observationally, however, for [CII] only very few measurements exist. Here we compare observations of CO, HI, and [CII] emission of a sample of nearby galaxies, drawn from the HERACLES, THINGS, and KINGFISH surveys. We find that within R-25, the average [CII] exponential radial profile is slightly shallower than that of the CO, but much steeper than the HI distribution. This is also reflected in the integrated spectrum ("global profile"), where the [CII] spectrum looks more like that of the CO than that of the HI. For one galaxy, a spectrally resolved comparison of integrated spectra was possible; other comparisons were limited by the intrinsic line-widths of the galaxies and the coarse velocity resolution of the [CII] data. Using high-spectral-resolution SOFIA [CII] data of a number of star forming regions in two nearby galaxies, we find that their [CII] linewidths agree better with those of the CO than the HI. As the radial extent of a given ISM tracer is a key input in deriving M-dyn from spatially unresolved data, we conclude that the relevant length-scale to use in determining M-dyn based on [CII] data, is that of the well-characterized CO distribution. This length scale is similar to that of the optical disk

    Measuring every particle's size from three-dimensional imaging experiments

    Full text link
    Often experimentalists study colloidal suspensions that are nominally monodisperse. In reality these samples have a polydispersity of 4-10%. At the level of an individual particle, the consequences of this polydispersity are unknown as it is difficult to measure an individual particle size from microscopy. We propose a general method to estimate individual particle radii within a moderately concentrated colloidal suspension observed with confocal microscopy. We confirm the validity of our method by numerical simulations of four major systems: random close packing, colloidal gels, nominally monodisperse dense samples, and nominally binary dense samples. We then apply our method to experimental data, and demonstrate the utility of this method with results from four case studies. In the first, we demonstrate that we can recover the full particle size distribution {\it in situ}. In the second, we show that accounting for particle size leads to more accurate structural information in a random close packed sample. In the third, we show that crystal nucleation occurs in locally monodisperse regions. In the fourth, we show that particle mobility in a dense sample is correlated to the local volume fraction.Comment: 7 pages, 5 figure

    Resolving the far-IR line deficit : photoelectric heating and far-IR line cooling in NGC 1097 and NGC 4559

    Get PDF
    The physical state of interstellar gas and dust is dependent on the processes which heat and cool this medium. To probe heating and cooling of the interstellar medium over a large range of infrared surface brightness, on sub-kiloparsec scales, we employ line maps of [C II] 158 mu m, [O I] 63 mu m, and [N II] 122 mu m in NGC 1097 and NGC 4559, obtained with the Photodetector Array Camera & Spectrometer on board Herschel. We matched new observations to existing Spitzer Infrared Spectrograph data that trace the total emission of polycyclic aromatic hydrocarbons (PAHs). We confirm at small scales in these galaxies that the canonical measure of photoelectric heating efficiency, ([C II] + [O I])/TIR, decreases as the far-infrared (far-IR) color, nu f(nu)(70 mu m) nu f(nu)(100 mu m), increases. In contrast, the ratio of far-IR cooling to total PAH emission, ([C II] + [O I])/PAH, is a near constant similar to 6% over a wide range of far-IR color, 0.5 , derived from models of the IR spectral energy distribution. Emission from regions that exhibit a line deficit is characterized by an intense radiation field, indicating that small grains are susceptible to ionization effects. We note that there is a shift in the 7.7/11.3 mu m PAH ratio in regions that exhibit a deficit in ([C II] + [O I])/PAH, suggesting that small grains are ionized in these environments

    Interpreting the Global Enteric Multicenter Study (GEMS) Findings on Sanitation, Hygiene, and Diarrhea

    Get PDF
    Sanitation and hygiene are global concerns, as reflected in international development and human rights policy . The Sustainable Development Goals (SDGs) include target 6.2: to “achieve access to adequate and equitable sanitation and hygiene for all and end open defecation”. Globally, about 2.5 billion people do not use improved sanitation, of whom 1 billion defecate in the open. Fecal contamination of the environment and poor handwashing are responsible for an estimated 577,000 deaths annually. This is likely an underestimation: there is emerging evidence that poor sanitation and hygiene contribute to undernutrition and could be responsible for approximately half of all child stunting. Much of the health impact of inadequate sanitation and hygiene is attributed to diarrheal disease and its secondary effects. However, diarrhea is difficult to measure, and sanitation and hygiene are difficult to link to health outcomes

    Active microrheology and simultaneous visualization of sheared phospholipid monolayers

    Get PDF
    Two-dimensional films of surface-active agents—from phospholipids and proteins to nanoparticles and colloids—stabilize fluid interfaces, which are essential to the science, technology and engineering of everyday life. The 2D nature of interfaces present unique challenges and opportunities: coupling between the 2D films and the bulk fluids complicates the measurement of surface dynamic properties, but allows the interfacial microstructure to be directly visualized during deformation. Here we present a novel technique that combines active microrheology with fluorescence microscopy to visualize fluid interfaces as they deform under applied stress, allowing structure and rheology to be correlated on the micron-scale in monolayer films. We show that even simple, single-component lipid monolayers can exhibit viscoelasticity, history dependence, a yield stress and hours-long time scales for elastic recoil and aging. Simultaneous visualization of the monolayer under stress shows that the rich dynamical response results from the cooperative dynamics and deformation of liquid-crystalline domains and their boundaries

    Dimethyl sulfide production: what is the contribution of the coccolithophores?

    Get PDF

    Quantitative imaging of concentrated suspensions under flow

    Full text link
    We review recent advances in imaging the flow of concentrated suspensions, focussing on the use of confocal microscopy to obtain time-resolved information on the single-particle level in these systems. After motivating the need for quantitative (confocal) imaging in suspension rheology, we briefly describe the particles, sample environments, microscopy tools and analysis algorithms needed to perform this kind of experiments. The second part of the review focusses on microscopic aspects of the flow of concentrated model hard-sphere-like suspensions, and the relation to non-linear rheological phenomena such as yielding, shear localization, wall slip and shear-induced ordering. Both Brownian and non-Brownian systems will be described. We show how quantitative imaging can improve our understanding of the connection between microscopic dynamics and bulk flow.Comment: Review on imaging hard-sphere suspensions, incl summary of methodology. Submitted for special volume 'High Solid Dispersions' ed. M. Cloitre, Vol. xx of 'Advances and Polymer Science' (Springer, Berlin, 2009); 22 pages, 16 fig
    corecore