3,495 research outputs found
A window into learning: case studies of online group communication and collaboration
The two case studies presented explore the potential offered by inâdepth qualitative analysis of studentsâ online discussion to enhance our understanding of how students learn. Both cases are used to illustrate how the monitoring and moderation of online student group communication can open up a âwindow into learningâ, providing us with new insights into complex problemâsolving and thinking processes. The cases offer examples of studentsâ âthinking aloudâ while problemâsolving, showing how and why they arrived at particular outcomes and the underlying thought processes involved. It is argued that these insights into studentsâ learning processes can in turn offer us the opportunity to adapt our own teaching practice in order to achieve a better pedagogical âfitâ with the learning needs of our students; for example, through a more precise or more timely intervention. It is also suggested that looking through this âwindowâ enables us to concentrate our assessment more closely on the process of task completion, rather than focusing solely on the end product
Finding Ways
In 2008 I was commissioned to write a poem which was subsequently set into a 700m ribbon of steel that meanders throughout the interior and exterior spaces of the development. The project was designated the title âFinding Waysâ, which I used loosely to explore the notion of discovery and getting back on track with oneâs life.
I began this challenging project with a view to achieving three key aims: to produce a poem, or series of poems, that would enliven the new medical facility of Roseberry Park by commenting on the areaâs heritage and the journeys that form a part of the medical facilityâs purpose; to promote positive interaction and reflection within the residents and users of the facility through the poem; to produce a poem that adhered to the severe restrictions imposed by the building plans, at the same time as it appeared seamless and unforced
Observations on wasting as a sign of disease in infancy
(1) "Wasting" is common amongst poor-class infants.
The careful management of pregnancy, labour, the early days of
infancy, and of breast feeding, is a factor of vast importance
in prophylaxis.(2) The main cause - unsuitable feeding - is preventable
by lay and medical education.(3) It is essential to diagnose between a "functional"
and an "organic dyspepsia ", since wasting may result from a considerable number of organic conditions.(4) Persistence in unsuitable feeding leads to "dyspepsia ",
which form a large group of infantile "upsets ", and which is a frequent cause of wasting.The causation, pathology and treatment of "dyspepsia"
(including "summer diarrhoea ") are discussed.(5) Congenital pyloric stenosis is not a rare condition
and should be constantly born in mind. The age and general
condition of the infant, and the length and type of history, vary
very considerably. Visible gastric peristalsis occurs to a slight extent, in certain other, less common conditions.(6) "Pink disease" - the cause as yet unknown - may lead
to a considerable degree of wasting, even in the breast fed.
The diagnosis is usually easy.(7) In childhood, there is a very important interdependence
between the absorption and utilization of fat,
calcium and phosphorus. Thomson considers the three main causes
of wasting to be:- inanition,
fat dyspepsia,
parental infection;
even in the second of these however, namely cases in which there
is a reduced tolerance to fat as shown by the passage of large
crumbly and pale motions (the "mĂŹlehnĂĄhrschaden" of Czerny, and
Finkelstein's "bilanz.storung "), the digestion and absorption
of fat are quite normal.(8) Fat splitting and absorption is normal in infantile
atrophy and in pyloric stenosis; but in atrophy, fat indigestion
occurs under two conditions: - (a) if diarrhoea develops, and
(b) with the use of the high fat content
dried milks.(9) Starvation is a frequent cause of wasting and the
"mehlr_ĂĄhrschaden "of Czerny and Keller is due rather to a deficiency of protein, vitamines and minerals, than to an excess
of carbohydrate. Such defieiency syndromes may be superadded
to the picture of malnutrition.(10) The effects of a high protein intake are little
to be feared.(11) The presence of infection is an important factor
in reducing the carbohydrate tolerance.(12) It is suggested that the estimation of the urinary
creatinine of wasted infants, would, by indicating the extent of
tissue breakdown, at least be of assistance in prognosis.(13) In infantile atrophy, no characteristic lesions are found post -mortem, even in the most severe cases.(14) Animals vary greatly in their susceptibility to
the various vitamin deficiencies, a fact which necessitates the
very cautious interpretation of animal experiments in relation
to human. disease.(15) In some animals, the health of the gastro -intestinal
tract depends upon the presence of accessory food factors in the
diet.(16) The thyroid gland is very sensitive to food conditions,
and especially so in early life.(17) The pathology of idiopathic oedema is uncertain,
but the condition requires thorough dietetic treatment.(18) The important and common "nutritional anaemia" of
infancy, is preventable.(19) A slight degree of vitamin A. deficiency is not
uncommon in poor children. LIilk is a poor source of A. and D,
and supplementary dosage of these vitamins is necessary in
infancy, especially at the time of weaning.(20) Egg yolk is the only known foodstuff containing
anti- rachitic power, to any extent.(21) Some workers are investigating the possibility of
a relationship between the phenomena associated with rickets,
malignant disease, and sex activity.(22) Vitamin D. prevents tetany, as it prevents Rickets;
it also promotes perfect tooth formation.(23) Several important points regarding the etiology
and pathogenesis of Pellagra, remain obscure. The conception
of the presence of "toxamins" in the normal basic foodstuffs
should be thoroughly tested or abandoned.(24) Certain factors in acidosis and alkalosis are discussed. The pathogenesis of "cyclical vomiting" is still
obscure. Ketosis is, in all probability, not the cause.(25) Of 146 infants below 1 year of age admitted to the
Sheffield Childrens' Hospital from 1.2.34. to 1.6.34, 91 were
"medical" cases. Of these 91, 41 were "dyspeptic ", and 11 had
congenital pyloric stenosis (including twin brothers). These
two groups are discussed in greater detail.(26) The importance to the infant, of an adequate diet
for the mother, and instruction and perseverance in breastfeeding,
is obvious, but neglected. Only thus is the subject
of artificial feeding one of the most important in the whole
field of therapeutics.(27) The great benefits of special dietaries (including
the administration of vitamin preparations) will be more
extensively enjoyed when time and intensive teaching increases
the faith in them.(28) Factors in the failure of breast -feeding are discussed.(29) Every hand fed baby should be raised, as quickly as
is compatible with its digestion, to a diet of full (boiled or pasteurised) cow's milk, with an added one ounce of sugar daily.
The majority consider that full milk should be reached by three
months of age; others consider this too strong for those below
nine months of age.(30) The more digestible modifications required by
special cases (especially in wasting and in prematurity) are
discussed. The dried milks ( "h ĂŹf- cream"), which cost a little more than fresh milk, are acceptedly the next choice.(31) "Partial vitamin deficiency" is no vague theory and
the employment of the vitamins (especially in infancy) abounds with
practical applications, which are of vital value to the practitioner,
but which are by no means fully realised. The fault of this lies
partly in the mal- organisation of society
The Enhancement of Peroxide-Cured Fluoroelastomer Rubber to Metal Bonding
A combi-cured& fluoroelastomer (FKM) rubber formulation was designed to yield 100% cohesive rubber failure when cured to cold-rolled steel with derivatives of polymeric silane adhesives. Three different categories of adhesives were tested: Unsaturated Polymeric Silane with Phosphonium Salt (UPSP-D), Unsaturated Polymeric Silane (UPS-L), and Saturated Polymeric Silane (SPS-L). Adhesion Inserts molded using ASTM Method D429 Method C all consistently yielded 100% cohesive rubber failure and showed adhesion strength in the range of 700 to 800 psi after being pulled at 2 per minute until break. After obtaining consistent 100% rubber failure, a design of experiment (DOE) was implemented to determine optimum metal pretreatment conditions as well as optimal rubber ingredients to yield maximum rubber retention and adhesion strength. A method was also developed to determine the locus of failure when the failure occurred at an interface using Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR FT-IR)
Thermosetting Polymers via Azide Alkyne Cycloaddition
This dissertation exploits properties inherent to azide-alkyne cycloaddition and applies practical solutions to difficult problems. Chapter II addresses structure-property relationships in glassy azido-alkyne matrices by varying the identity of the central linkage within tetrapropargyl bis-aniline-type crosslinkers, and by the addition or omission of Cu(I) catalyst. This systematic study showed that an ether or methylene linkage yielded lower melting tetrapropargyl crosslinkers that were soluble in, and produced homogeneous, networks when cured with, a standard azido resin, di(3-azido-2-hydroxypropyl) ether of bisphenol-A; in contrast, a sulfone linkage yielded a relatively insoluble crosslinker and poorly dispersed, heterogeneous networks when reacted with the same resin. The study also showed that the presence of Cu(I) and the concomitant network regularity afforded by a single triazole regioisomer increased compression modulus and Tg. However, due to increased kinetics of reaction the catalyzed system was much harder to process.
Chapter III introduces the use of azide-alkyne cycloaddition as an alternative curing mechanism in non-isocyanate polyurethanes (NIPU). Several commercial polyisocyanate resins derived from hexamethylene diisocyanate were converted to propargyl carbamates by reaction with propargyl alcohol; azidated co-reactants were synthesized from several different commercial polyols including polyether, polyester, and polyacrylic types. Each resin/coreactant combination was rendered into a two-component coating system and cured in the presence and absence of Cu(I) catalyst. Coating properties were compared to the precursor polyisocyanate/polyol coating systems, and the best-performing NIPU coating was found to result from a propargylated allophanate resin, XP2580, and an azidated polyacrylic resin, Setalux DA870. The latter coatings met or exceeded the properties of the precursor polyurethane coatings except for uncatalyzed rate of cure at ambient temperature.
Chapter IV focused on increasing the sluggish curing kinetics observed for the azide-propargyl systems. In Chapter III, this was overcome by the addition of Cu(I). However, this also caused discoloration to the coating. This chapter focused on making an aesthetically pleasing coating that cured similarly to the as received material. This was achieved by the synthesis of 2-hydroxyethyl propiolate (2-HEP) and its subsequent reaction with XP2580 to form a propiolate modified polyurethane resin. Incorporation of the propiolate functionality increased the rate of reaction with the azidated Setalux DA870, such that the observed curing kinetics were approximately the same as that of the as-received resin pairs.
Chapter V, the final chapter, addressed problem that plagued the carbamates synthesized in the previous two chapters. Upon propargylation, the viscosity increased dramatically, making the resins difficult to work with unless diluted by an appreciable amount of organic solvents. This was overcome by sacrificing a fraction of the isocyanate functionality to attach internal plasticizing moieties consisting of a monoalkyl ether of either ethylene glycol (EG) or diethylene glycol (DEG). This approach was successful in reducing coating system viscosity, and created a softer and more flexible coating with a lower glass transition. This study showed that the length of alkyl chain, rather than the choice of EG or DEG, produced the larger effect on viscosity and coating properties, i.e., butyl provided a much greater plasticizing effect than ethyl
Single site observations of \textit{TESS} single transit detections
Context: TESS has been successfully launched and has begin data acquisition.
To expedite the science that may be performed with the resulting data it is
necessary to gain a good understanding of planetary yields. Given the observing
strategy employed by TESS the probability of detecting single transits in long
period systems is increased. These systems require careful consideration.
Aims: To simulate the number of TESS transit detections during its 2 year
mission with a particular emphasis on single transits. Additionally, to
determine the feasibility of ground-based follow-up observations from a single
site.
Methods: A distribution of planets is simulated around the 4 million
stars in the TESS Candidate Target List. These planets are tested for
detectable transits and characterised. Based on simulated parameters the single
transit detections are further analysed to determine which are amenable to
ground-based follow-up.
Results: TESS will discover an approximate lower bound of 4700 planets with
around 460 being single transits. A large fraction of these will be observable
from a single ground-based site. This paper finds that, in a single year,
approximately 1000 transit events of around 320 unique TESS single transit
detections are theoretically observable.
Conclusions: As we consider longer period exoplanets the need for exploring
single transit detections increases. For periods days the number of
single transit detections outnumber multitransits by a factor of 3 (8218
and 257 respectively) a factor which only grows as longer period
detections are considered. Therefore, it is worth expending the extra effort
required to follow-up these more challenging, but potentially very rewarding,
discoveries. Additionally, we conclude that a large fraction of these targets
can be theoretically observed from just a single ground-based site.Comment: 12 pages, 19 figures. To be published in Astronomy and Astrophysic
Acoustic measurements of boundary layer flux profiles over a sandy rippled bed under regular waves
The study of boundary layer sediment transport processes requires contemporaneous measurements of the bedforms, the flow and the sediment movement. Obtaining these three parameters, at the required temporal-spatial resolutions, has been traditionally difficult, especially within a few centimetres of the bed. To circumvent some of the deployment of an acoustic backscatter system, ABS, an acoustic ripple profiler, ARP, and an acoustic Doppler velocity profiler, ADVP, to measure sediment entrainment processes above a rippled bed under regular waves. High resolution acoustic observations of the suspend sediment concentration, flow and bedforms have been collected. Here we report on some of the initial results obtained from this study
The goal dependent automaticity of drinking habits
In recent treatments of habitual social behaviour, habits are conceptualised as a form of goal-directed automatic behaviour that are mentally represented as goal-action links. Three experiments tested this conceptualisation in the context of studentsâ drinking (alcohol consumption) habits. Participants were randomly assigned to conditions where either a goal related to drinking behaviour (socialising) was activated, or an unrelated goal was activated. In addition, participantsâ drinking habits were measured. The dependent variable in Experiments 1 and 2 was readiness to drink, operationalised by speed of responding to the action concept âdrinkingâ in a verb verification task. Experiment 3 used uptake of a voucher to measure drinking behaviour. Findings supported the view that when habits are established, simply activating a goal related to the focal behaviour automatically elicits that behaviour. These findings are consistent with a goal-dependent conception of habit. Possibilities for interventions designed to attenuate undesirable habitual behaviours are considered
Do gender and year of study affect the ability of the theory of planned behaviour to predict binge-drinking intentions and episodes?
Background: The present study tested the utility of the theory of planned behaviour (TPB), augmented with anticipated regret, as a model to predict binge-drinking intentions and episodes among female and male undergraduates and undergraduates in different years of study. Method: Undergraduate students (Nâ=â180, 54 males, 126 females, 60 per year of study) completed baseline measures of demographic variables, binge-drinking episodes (BDE), TPB constructs and anticipated regret. BDE were assessed one-week later. Results: The TPB accounted for 60% of the variance in female undergraduates' intentions and 54% of the variance in male undergraduates' intentions. The TPB accounted for 57% of the variance in intentions in first-year undergraduates, 63% of the variance in intentions in second-year undergraduates and 68% of the variance in intentions in final-year undergraduates. Follow-up BDE was predicted by intentions and baseline BDE for female undergraduates as well as second- and final-year undergraduates. Baseline BDE predicted male undergraduatesâ follow-up BDE and first-year undergraduatesâ follow-up BDE. Conclusion: Results show that while the TPB constructs predict undergraduatesâ binge-drinking intentions, intentions only predict BDE in female undergraduates, second- and final-year undergraduates. Implications of these findings for interventions to reduce binge drinking are outlined
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