Torque measurement as a tool to monitor the breakdown of cassava starch gels, by the effect of Fenton's initiator for graft copolymerization

The use of a combined stirrer-torque meter allows for monitoring viscosity during polymerizations and other reactions, much faster and more continuous than off-line viscosity measurements. This method was applied in previous research about the grafting of acrylic acid onto cassava starch using Fenton's initiator. In this article the method is used to assess the effect of Fenton's initiator on gels of cassava starch in the absence of the monomer. The intention here is to activate the starch selectively first, which could improve graft selectivity. The interaction of a redox graft copolymerization initiator with starch gels when there is no monomer in the system yet, is hardly ever addressed in grafting literature. Remarkably, the present experimental study shows a rapid viscosity decrease of the starch gel, in the order of 70% in less than 2 min, at conditions reflecting graft copolymerization. This result must be considered a major setback for the application of pre-initiation. Torque measurement also allows to identify the important steps in the reaction of Fenton's reagent with starch without the need to do other, more intensive analyses on the chemistry. For example, it could be concluded that the second stage of Fenton's reaction, the slower decomposition of hydrogen peroxide by Fe3+ ions, accounts for another 20% loss of the original gel viscosity but over a longer period, some 30–60 min. Possible further decrease over a longer period is too slow or small relative to the measuring accuracy of the torque meter. FTIR analyses show the occurrence of peaks at 1730–1740 cm−1 in starch which has been subjected to reaction with Fenton's. These peaks are in the range of the vibrational frequencies associated to C[dbnd]O bonds, that are not present in the original starch. This provides at least a strong indication for oxidative degradation of the starch chains

Accelerated discharge of patients in the event of a major incident: observational study of a teaching hospital

BACKGROUND: Since October 2002 in the UK Primary Care Trusts (PCTs) have had statutory responsibility for having and maintaining a Major Incident plan and since 2005 they have been obliged to co-operate with other responders to an incident. We aimed to establish the number of beds in our Trust which could be freed up over set periods of time in the event of a major incident and the nature and quantity of support which might be required from PCTs in order to achieve this. METHODS: Repeated survey over 12 days in 3 months of hospital bed occupancy by type of condition and discharge capacity in an 855-bed UK tertiary teaching hospital also providing secondary care services. Outcome measures were bed spaces which could be generated, timescale over which this could happen and level and type of PCT support which would be required to achieve this. RESULTS: Mean beds available were 78 immediately, a further 69 in 1–4 hours and a further 155 in 4–12 hours, generating a total of 302 beds (36% of hospital capacity) within 12 hours of an incident. This would require support from a PCT of 150,000 population of 10 nursing care beds, 20 therapy-supported intermediate care beds, and 25 care packages in patients' own homes. CONCLUSION: In order to fulfill the requirements of the Civil Contingencies Act 2004, PCTs should plan to have surge capacity in the order of 30 residential placements and 25 community support packages per 150,000 population to support Acute Trusts in the event of a major incident

Improving Geographical Locality of Data for Shared Memory Implementations of PDE Solvers

On cc-NUMA multi-processors, the non-uniformity of main memory latencies motivates the need for co-location of threads and data. We call this special form of data locality, geographical locality, as the non-uniformity is a consequence of the physical distance between the cc-NUMA nodes. In this article, we compare the well established method of exploiting the rst-touch strategy using parallel initialization of data to an application-initiated page migration strategy as means of increasing the geographical locality for a set of important scienti c applications. Four PDE solvers parallelized using OpenMP are studied; two standard NAS NPB3.0-OMP benchmarks and two kernels from industrial applications. The solvers employ both structured and unstructured computational grids. The main conclusions of the study are: (1) that geographical locality is important for the performance of the applications, (2) that application-initiated migration outperforms the rsttouch scheme in almost all cases, and in some cases even results in performance which is close to what is obtained if all threads and data are allocated on a single node. We also suggest that such an application-initiated migration could be made fully transparent by letting the OpenMP compiler invoke it automatically.

A counterbalanced cross-over study of the effects of visual, auditory and no feedback on performance measures in a simulated cardiopulmonary resuscitation

<p>Abstract</p> <p>Background</p> <p>Previous research has demonstrated that trained rescuers have difficulties achieving and maintaining the correct depth and rate of chest compressions during both in and out of hospital cardiopulmonary resuscitation (CPR). Feedback on rate and depth mitigate decline in performance quality but not completely with the residual performance decline attributed to rescuer fatigue. The purpose of this study was to examine the effects of feedback (none, auditory only and visual only) on the quality of CPR and rescuer fatigue.</p> <p>Methods</p> <p>Fifteen female volunteers performed 10 minutes of 30:2 CPR in each of three feedback conditions: none, auditory only, and visual only. Visual feedback was displayed continuously in graphic form. Auditory feedback was error correcting and provided by a voice assisted CPR manikin. CPR quality measures were collected using SkillReporter^®software. Blood lactate (mmol/dl) and perceived exertion served as indices of fatigue. One-way and two way repeated measures analyses of variance were used with alpha set <it>a priori </it>at 0.05.</p> <p>Results</p> <p>Visual feedback yielded a greater percentage of correct compressions (78.1 ± 8.2%) than did auditory (65.4 ± 7.6%) or no feedback (44.5 ± 8.1%). Compression rate with auditory feedback (87.9 ± 0.5 compressions per minute) was less than it was with both visual and no feedback (p < 0.05). CPR performed with no feedback (39.2 ± 0.5 mm) yielded a shallower average depth of compression and a lower percentage (55 ± 8.9%) of compressions within the accepted 38-50 mm range than did auditory or visual feedback (p < 0.05). The duty cycle for auditory feedback (39.4 ± 1.6%) was less than it was with no feedback (p < 0.05). Auditory feedback produced lower lactate concentrations than did visual feedback (p < 0.05) but there were no differences in perceived exertion.</p> <p>Conclusions</p> <p>In this study feedback mitigated the negative effects of fatigue on CPR performance and visual feedback yielded better CPR performance than did no feedback or auditory feedback. The perfect confounding of sensory modality and periodicity of feedback (visual feedback provided continuously and auditory feedback provided to correct error) leaves unanswered the question of optimal form and timing of feedback.</p