Sixth Form Examinations in Art and Design

Examinations - in any subject - at 'A' level form the major influence on teaching the Sixth Form and the backwash effect of this form of examination has its effect through the earlier years of secondary education. The main objections to the present system is that examinations in the Sixth Form are too specialised and syllabuses require much study in depth. Contrarywise, when Art examinations are under scrutiny they are often criticised for lack of specialisation and depth of study. Often criticisms of art examination are vague and are simply side-swipes, which examining bodies are adept at parrying, whose power has been generated simply on the basis that certain students have not passed or gained the right grades, which a teacher believed they should have done

Nitric Oxide Bioavailability and Its Potential Relevance to the Variation in Susceptibility to the Renal and Vascular Complications in Patients With Type 2 Diabetes

OBJECTIVE—We compared the renal and systemic vascular (renovascular) response to a reduction of bioavailable nitric oxide (NO) in type 2 diabetic patients without nephropathy and of African and Caucasian heritage. RESEARCH DESIGN AND METHODS—Under euglycemic conditions, renal blood flow was determined by a constant infusion of paraminohippurate and changes in blood pressure and renal vascular resistance estimated before and after an infusion of l-Ng-monomethyl-l-arginine. RESULTS—In the African-heritage group, there was a significant fall in renal blood flow (Δ−46.0 ml/min per 1.73 m(2); P < 0.05) and rise in systolic blood pressure (Δ10.0 mmHg [95% CI 2.3–17.9]; P = 0.017), which correlated with an increase in renal vascular resistance (r(2) = 0.77; P = 0.004). CONCLUSIONS—The renal vasoconstrictive response associated with NO synthase inhibition in this study may be of relevance to the observed vulnerability to renal injury in patients of African heritage

Intensified Liquid-Liquid Extraction Technologies in Small Channels: A Review

Solvent extraction is a key separation process in several industries. Mixer-settlers and agitated or pulsed columns are mainly used as liquid-liquid contactors. However, these units require large solvent inventories and long residence times, while flow fields are often not uniform and mixing is poor. These drawbacks can be overcome with process intensification approaches where small channel extractors are used instead. The reduced volumes of small units in association with the increased efficiencies facilitate the use of novel, often expensive, but more efficient and environmentally friendly solvents, such as ionic liquids. The small throughputs of intensified contactors, however, can limit their full usage in industrial applications, thus robust scale-up strategies need to be developed. This paper reviews promising intensified technologies for liquid-liquid extractions based on small channels. In particular, extractions in single channels and in confined impinging jets are considered. The increase in throughput via scale-out approaches with appropriate manifolds is discussed, based on the use of many channels in parallel. The combination of small channels and centrifugal forces is exploited in counter-current chromatography (CCC) systems where many mixing and settling steps are combined within the contactors. Scale up is possible via centrifugal partition chromatography (CPC) configurations

Bostonia. Volume 6

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs

Homotopy types of stabilizers and orbits of Morse functions on surfaces

Let $M$ be a smooth compact surface, orientable or not, with boundary or without it, $P$ either the real line $R^1$ or the circle $S^1$, and $Diff(M)$ the group of diffeomorphisms of $M$ acting on $C^{\infty}(M,P)$ by the rule $h\cdot f\mapsto f \circ h^{-1}$, where $h\in Diff(M)$ and $f \in C^{\infty}(M,P)$. Let $f:M \to P$ be a Morse function and $O(f)$ be the orbit of $f$ under this action. We prove that $\pi_k O(f)=\pi_k M$ for $k\geq 3$, and $\pi_2 O(f)=0$ except for few cases. In particular, $O(f)$ is aspherical, provided so is $M$. Moreover, $\pi_1 O(f)$ is an extension of a finitely generated free abelian group with a (finite) subgroup of the group of automorphisms of the Reeb graph of $f$. We also give a complete proof of the fact that the orbit $O(f)$ is tame Frechet submanifold of $C^{\infty}(M,P)$ of finite codimension, and that the projection $Diff(M) \to O(f)$ is a principal locally trivial $S(f)$-fibration.Comment: 49 pages, 8 figures. This version includes the proof of the fact that the orbits of a finite codimension of tame action of tame Lie group on tame Frechet manifold is a tame Frechet manifold itsel

Multipurpose High Frequency Electron Spin Resonance Spectrometer for Condensed Matter Research

We describe a quasi-optical multifrequency ESR spectrometer operating in the 75-225 GHz range and optimized at 210 GHz for general use in condensed matter physics, chemistry and biology. The quasi-optical bridge detects the change of mm wave polarization at the ESR. A controllable reference arm maintains a mm wave bias at the detector. The attained sensitivity of 2x10^10 spin/G/(Hz)1/2, measured on a dilute Mn:MgO sample in a non-resonant probe head at 222.4 GHz and 300 K, is comparable to commercial high sensitive X band spectrometers. The spectrometer has a Fabry-Perot resonator based probe head to measure aqueous solutions, and a probe head to measure magnetic field angular dependence of single crystals. The spectrometer is robust and easy to use and may be operated by undergraduate students. Its performance is demonstrated by examples from various fields of condensed matter physics.Comment: submitted to Journal of Magnetic Resonanc

Population dynamics of fruitflies in British Columbia

Fluctuations in the populations of three species of the genus Drosophila were studied for fourteen months at an isolated fruitdump in the southern Okanagan Valley of British Columbia. The fruitdump was considered to provide ideal conditions for overwintering since it contained vast quantities of food and generated abundant heat. However, only D. hydei overwintered, whereas D. pseudoobscura and D. melanogaster did not. D. hydei seemed to occupy the most desirable location on the fruitdump, to the exclusion of the other species. None of the three species oversummered at the dump. The question of maintenance of D. pseudoobscura and D. melanogaster populations is discussed

Automorphisms of graphs of cyclic splittings of free groups

We prove that any isometry of the graph of cyclic splittings of a finitely generated free group $F_N$ of rank $N\ge 3$ is induced by an outer automorphism of $F_N$. The same statement also applies to the graphs of maximally-cyclic splittings, and of very small splittings.Comment: 22 pages, 5 figures. Small modifications. To appear in Geometriae Dedicat

Stratigraphy, Radiocarbon Dating and Culture History of Charlie Lake Cave, British Columbia

Three seasons of fieldwork at Charlie Lake Cave, British Columbia, have revealed a sequence of stratified deposits that spans the Late Pleistocene and entire Holocene. Analyses of sediments, radiocarbon dates, faunal remains, and artifacts show that the site was first occupied by people at about 10 500 B.P., when local environments were more open than today. By 9500 B.P., boreal forest had moved into the area, and human use of the site was minimal until about 7000 B.P., when a brief occupation of the site probably included a human burial. Use of the site intensified after about 4500 B.P., possibly because the cave became more accessible. The site was used both as a residential base camp and as a more temporary hunting station or lookout. &nbsp; Article Summary by Jonathan C. Driver, May 2015 &nbsp; After we had completed our excavations in 1991 we decided that we should focus on writing up what we had excavated, and not undertake further excavations at the site. This paper was written to summarize our state of knowledge about the archaeological remains at the site, and focused on describing the stone tools, the overall stratigraphy, and the dating. The stratigraphic summary replaced earlier work based on the 1983 excavations, and we were able to refine our dating of the site as a result of more radiocarbon dates. The different cultural periods were based mainly on the work done by Martin Handly for his M.A. thesis at Trent University. The long list of authors reflects the need for a team approach to archaeological work, and include the project directors (Knut Fladmark and Jon Driver), stone tool analysis and development of the cultural sequence (Martin Handly), animal bone analysis (Randall Preston and Jon Driver), sediment analysis (Greg Sullivan and Knut Fladmark), and radiocarbon dating (Erle Nelson). The most important aspect of the site is that it preserves a very rare record of humanly made artifacts dating from the end of the last ice age (at least 10,500 BC) to very recent times. The many layers at the site allow us to separate the different cultural periods. Good preservation of bone allowed us to submit radiocarbon dates that provide approximate ages for the various cultures that used the site. The artifacts that exhibit the most change through time are projectile points – the sharp stone tips for spears, darts and arrows. In much of western Canada it is difficult to date archaeological sites, because many of them are found in shallow soils where radiocarbon dating is difficult for two reasons. First, animal bone is often not preserved due to the acidic nature of the soils. Second, although charcoal is often found, it cannot be reliably associated with human activity, because natural forest fires also produce charcoal. As a result, archaeologists look at the style of the projectile points to assign approximate ages. Tse’K’wa provides an opportunity to link artifacts of different styles to radiocarbon dates in a site with many distinct layers. So Tse’K’wa is a foundation for understanding the sequence of different cultures in the region. The article also discusses the possible early presence of microblade technology. Microblades are the most efficient way of producing a cutting edge when the base technology is chipped stone. A small piece of high-quality raw material (known as the core) is shaped in such a way that numerous parallel-sided slivers of stone can be removed. These “microblades” can then be hafted in wood or antler to form knives or arrow barbs. The concept is rather like our utility knives that have replaceable blades. This technology allows people to carry small quantities of high quality stone with them, ensuring that they always have a sharp blade available. Not all archaeologists agree that the early microblade core from Tse’K’wa is part of this technology, because it doesn’t conform to the classic methods of core manufacture. However, we argue that evidence for the removal of microblades is very obvious, and the lack of classic core preparation is because of the tabular nature of the raw material. The paper also introduces some information about animal bones, including the raven burials, evidence for environmental change, and the presence of collared lemming. These topics were subsequently explored in more detail in other papers