Collecting Feedback during Software Engineering Experiments

Objective: To improve the qualitative data obtained from software engineering experiments by gathering feedback during experiments. Rationale: Existing techniques for collecting quantitative and qualitative data from software engineering experiments do not provide sufficient information to validate or explain all our results. Therefore, we would like a cost-effective and unobtrusive method of collecting feedback from subjects during an experiment to augment other sources of data. Design of study: We formulated a set of qualitative questions that might be answered by collecting feedback during software engineering experiments. We then developed a tool to collect such feedback from experimental subjects. This feedback-collection tool was used in four different experiments and we evaluated the usefulness of the feedback obtained in the context of each experiment. The feedback data was triangulated with other sources of quantitative and qualitative data collected for the experiments. Results: We have demonstrated that the collection of feedback during experiments provides useful additional data to: validate the data obtained from other sources about solution times and quality of solutions; check process conformance; understand problem solving processes; identify problems with experiments; and understand subjects perception of experiments. Conclusions: Feedback collection has proved useful in four experiments and we intend to use the feedback-collection tool in a range of other experiments to further explore the cost-effectiveness and limitations of this technique. It is also necessary to carry out a systematic study to more fully understand the impact of the feedback-collecting tool on subjects performance in experiments.     

Oxidation of α-tocopherol to α-tocopheryl quinone by carbon tetrachloride-ethanol solvent

The addition of small amounts of CCl₄ to ethanolic solutions of α-tocopherol, vitamin A acetate or β-carotene caused destruction of these fat-soluble compounds. The oxidation product of α-tocopherol was identified as α-tocopheryl quinone by UV and IR spectral analysis. Maximum conversion to the quinone occurred with a ratio of CCl₄ to ethanol of 25∶75 (v/v).     

Encoding crystal microstructure and chain folding in the chemical structure of synthetic polymers

The development of robust methodologies to control the solid-state structure of polymeric materials by appropriate design of the macromolecular architecture has a crucial impact on the mechanical properties of these materials. Here, we demonstrate the feasibility of controlling chain folding of polymers by steric interactions only, in contrast to previous attempts aimed at engineering polymer crystallization through hydrogen bonding. In a linear synthetic macromolecule similar to polyethylene, we encoded structural instructions that are translated during a crystallization process to generate a unique, semi-crystalline morphology with structure-controlled crystal thickness of approximately 5 nm that remains constant over a wide temperature range. The molecular code consists of a linear backbone alternating crystallizable, long alkyl sequences of monodisperse sizes separated by short spacers containing side-chains and acting as stops and fold-controlling units. This simple strategy could be used to produce advanced polymeric materials with fine control of the crystalline and amorphous regions.     

Phenotype, cytokine production and cytolytic capacity of fresh (uncultured) tumour-infiltrating T lymphocytes in human renal cell carcinoma

Abnormalities in the vestibulo-ocular reflex (VOR) after unilateral vestibular injury may cause symptomatic gaze instability. We compared five subjects who had unilateral vestibular lesions with normal control subjects. Gaze stability and VOR gain were measured in three axes using scleral magnetic search coils, in light and darkness, testing different planes of rotation (yaw and pitch), types of stimulus (sinusoids from 0.8 to 2.4 Hz, and transient accelerations) and methods of rotation (active and passive). Eye velocity during horizontal tests reached saturation during high-velocity/acceleration ipsilesional rotation. Rapid vertical head movements triggered anomalous torsional rotation of the eyes. Gaze instability was present even during active rotation in the light, resulting in oscillopsia. These abnormal VOR responses are a consequence of saturating nonlinearities, which limit the usefulness of frequency-domain analysis of rotational test data in describing these lesions.     

Local application of LDL promotes intimal thickening in the collared carotid artery of the rabbit

Oxidized LDL (oxLDL) has been implicated in atherogenesis on the basis of in vitro studies and is present in atherosclerotic lesions. The aim of this study was to investigate the effects of LDL and oxLDL on intimal thickening in vivo. Intimal thickening was evoked by the placement of silicone collars around the carotid arteries of rabbits for 2 weeks. The collars were connected to osmotic minipumps containing LDL (7 micrograms h-1, n = 16 arteries), oxLDL (Cu2+ oxidized, 7 micrograms h-1, n = 16), or phosphate-buffered saline (5 microL h-1, n = 16). Segments proximal to the collars served as controls. Collar placement without lipoprotein application resulted in the appearance of alpha-SMC actin-immunoreactive cells in the intima, thereby increasing the intimal thickness from 5 +/- 1 to 26 +/- 5 microns. The perivascular infusion of LDL or oxLDL within the collar significantly enhanced the development of the intima ninefold and sevenfold, respectively. The large intimas resulting from lipoprotein exposure were infiltrated by macrophages and T lymphocytes, and the intimal collagen area was increased from 5 +/- 2% in the discrete collar-induced intima to approximately 20% in the lipoprotein-evoked lesions. In conclusion, the local vascular application of LDL, oxidized in vitro or possibly in vivo, elicited an inflammatory-fibroproliferative response characteristic of arteriosclerotic lesions, thereby demonstrating an active role for this class of lipoproteins in the disease process.     

Achilles tendon rupture. Surgical or non-surgical treatment

Opinions differ about the proper treatment of Achilles tendon rupture. 38 patients with acute total rupture of the Achilles tendon were included in a comparative study of operative as against non-operative treatment. 21 of the patients were treated operatively and 17 non-operatively. The follow-up time was 6-53 months. Three of the non-operated patients but none of the operated group experienced major complications. Ten of the non-operated patients and 14 of the non-operated group experienced minor complications. In the non-operated patients the plantar-flexion range was significantly reduced in the injured foot compared with the other foot (p = 0.03). Because of more re-ruptures and reduced muscle strength in the non-operative group, operative treatment is recommended for active persons. Non-operative treatment may be considered for older people.     

Gate length electric parameter dependences of ultra-submicrometre delta -doped pseudomorphic HEMTs

AlGaAs/InGaAs/GaAs MODFETs having 20% indium in the channel and Si planar doping (5*10/sup 12/ cm/sup -2/) have been fabricated with gate lengths of 0.1-0.7 mu m and a width of 100 mu m. Gates that are longer than 0.2 mu m are T-shaped and the narrower gates (0.1 and 0.15 mu m) are triangular. From DC measurement a maximum G/sub m/ of 1100 mS/mm has been obtained. The current gain cutoff frequency F/sub t/ corrected for the access resistances is 145 GHz, corresponding to an intrinsic transition frequency of 220 GHz.<>     

Reduction of radiocesium transfer to animal products using sustained release boli with ammoniumiron(III)-hexacyanoferrate(II)

A sustained release bolus with the cesium binder ammoniumiron(III)-hexacyanoferrate (AFCF) has been developed as a countermeasure for small ruminants grazing pastures contaminated by radiocesium (134Cs+137Cs). The boli (40-50 g) are produced by compression of a mixture of AFCF, barite and wax. The release of AFCF from boli labelled with 137Cs-iron-hexacyanoferrate complex was studied in laboratory sheep. The release rate followed first order kinetics during the 108 d of observation and decreased from 40 to 22, 110 to 35 and 280 to 25 mg d-1 in sheep treated with 1, 2 or 3 boli respectively. The efficiency of boli in reducing radiocesium transfer to meat and milk was tested in laboratory studies with goats fed 134Cs tracer. Until 40 d after treatment the transfer of radiocesium to milk was reduced by 35%, 60% and 85% in goats given 1, 2 or 3 boli, respectively. The reduction in radiocesium transfer persisted for 90 d but with a lower efficiency. A similar relationship was found between number of boli and the reduction in radiocesium transfer to meat with an observed maximal reduction of 60%.