A measles epidemic controlled by immunisation

AIM: In 1997, an immunisation campaign, using measles-mumps-rubella vaccine, was planned for children aged 2-10 years to prevent a measles epidemic predicted by mathematical modelling. The epidemic started before the campaign and is described here. METHOD: Measles hospitalisation, notification and laboratory data were combined. RESULTS: The epidemic started in April 1997 and was largely over by January 1998. No deaths were identified and only one hospitalisation was coded as measles encephalitis, compared to seven deaths and ten cases of measles encephalitis in the 1991 epidemic. For the 12 months from 1 March 1997 there were 2,169 (60 per 100,000) measles cases identified, 314 (9 per 100,000) of whom were hospitalised. Two-thirds of hospitalised cases were notified. The age-standardised measles incidence rates were 33, 34, and 174 per 100,000 for Europeans, Maori and Pacific people, respectively. The respective age-standardised hospitalisation rates were 4, 9 and 32 per 100,000. Measles incidence was highest for under one-year-olds (904 per 100,000) and low for 11-16 year-olds (27 per 100,000)--the cohort previously offered a second vaccine dose. Most cases were aged 10 years and under, and this group were the main drivers of virus transmission. CONCLUSIONS: The immunisation campaign prevented 90-95% of predicted cases. The campaign was appropriately targeted at children aged 10 years and under.     

Parametric sensitivity study of operating and design variables in wellbore heat exchangers

A numerical study was conducted to evaluate the potential for using Wellbore Heat Exchangers (WBHX) to extract heat for use in electricity generation. Variables studied included operational parameters such as wellbore geometries, working fluid properties, circulation rates, and regional properties including basal heat flux and formation rock type. Energy extraction is strongly affected by fluid residence time, heat transfer contact area, and formation thermal properties. Water appears to be the most appropriate working fluid. The effects of tubing properties and casing lengths are of second-order.On the basis of a sensitivity study, a Best Case model was simulated, and results compared against the geothermal fluid requirements of existing power generation plants that use low-temperature geothermal fluids. Even assuming ideal work conversion to electricity, a WBHX cannot supply sufficient energy to generate 200 kWe at the onset of pseudo-steady-state (PSS) conditions. Using realistic conversion efficiencies it is unlikely that the system would be able to generate 50 kWe at the onset of PSS.     

Open-ended categorization of chick-a-dee calls by black-capped chickadees (Poecile atricapilla).

The authors trained black-capped chickadees (Poecile atricapilla) in an operant discrimination with exemplars of black-capped and Carolina chick-a-dee calls, with the goal of determining whether the birds memorized the calls of conspecifics and heterospecifics or classified the calls by species. Black-capped calls served as both rewarded (S+) and unrewarded (S-) stimuli (the within-category discrimination), whereas Carolina chick-a-dee calls served as S-s (the between-category discrimination) in the black-capped chick-a-dee call S+ group. The Carolina call S+ group had Carolina calls as S+s and S-s (within-category) and black-capped calls as S-s (between-category). Both groups discriminated between call categories faster than within a call category. In 2 subsequent experiments, both S+ groups showed transfer to novel calls and propagation back to between-category calls. The results favor the hypothesis that the acoustically similar social calls of the 2 species constitute separate open-ended categories. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Abdominal compartment syndrome

The ACS is a clinical entity that develops from progressive, acute increases in IAP and affects multiple organ systems in a graded fashion because of differential susceptibilities. The gut is the organ most sensitive to IAH, and it develops evidence of end-organ damage before the development of the classic renal, pulmonary, and cardiovascular signs. Intracranial derangements with ACS are now well described. Treatment involves expedient decompression of the abdomen, without which the syndrome of end-organ damage and reduced oxygen delivery may lead to the development of multiple organ failure and, ultimately, death. Multiple trauma, massive hemorrhage, or protracted operation with massive volume resuscitation are the situations in which the ACS is most frequently encountered. Knowledge of the ACS, however, is also essential for the management of critically ill pediatric patients (especially those with AWD) and in understanding the limitations of laparoscopy. The role of IAH in the pathogenesis of NEC, central obesity co-morbidities, and pre-eclampsia/eclampsia remains to be fully studied.     

Acute myeloid leukemia-type chemotherapy for newly diagnosed patients without antecedent cytopenias having myelodysplastic syndrome as defined by French-American-British criteria: a Cancer and Leukemia Group B Study

PURPOSE: To determine the treatment outcome of standard acute myeloid leukemia (AML)-type chemotherapy in a subset of patients with newly diagnosed myelodysplastic syndromes (MDS) compared with that of patients with de novo AML as defined using French-American-British (FAB) criteria. In addition, to determine the pretreatment variables having prognostic significance for treatment outcome in patients with MDS. PATIENTS AND METHODS: Nine hundred seven newly diagnosed patients with no history of cytopenias having a local institutional de novo AML successfully karyotyped and treated on Cancer and Leukemia Group B (CALGB) protocols for AML from 1984 to 1992. Thirty-three of the 907 patients were reclassified as having MDS on central pathology review using FAB criteria and form the basis of this analysis. RESULTS: The treatment outcomes for patients with MDS and AML were similar; the complete remission (CR) rate was 79% and 68%, respectively (P = .37); median CR duration was 11 and 15 months, respectively (P = .28); and median survival was 13 and 16 months, respectively (P = .72). For the MDS patients, there were no prognostic variables for CR rate identified. For CR duration, only the Sanz classification had prognostic value. The prognostic factors for survival in a univariate analysis included age, WBC count, Sanz classification, and percent blood blasts. In a proportional hazards analysis of survival, age greater than 60 years and WBC less than 2.6 x 10(9)/L were adverse prognostic factors. CONCLUSION: In patients with no known history of cytopenias who are treated intensively at diagnosis, the FAB distinctions between MDS (refractory anemia with excess blasts and refractory anemia with excess blasts in transformation) and AML appear to have little therapeutic relevance.     

Expression of the neural cell adhesion molecule CD56 is associated with short remission duration and survival in acute myeloid leukemia with t(8;21)(q22;q22)

Although acute myeloid leukemia (AML) with t(8;21) (q22;q22) is associated with a high complete remission (CR) rate and prolonged disease-free survival, treatment outcome is not universally favorable. Identifying factors that predict for treatment outcome might allow therapy to be optimized based on risk. AML with t(8;21) has a distinctive immunophenotype, characterized by expression of the myeloid and stem cell antigens CD13, CD15, CD34, and HLADr, and frequent expression of the B-cell antigen CD19 and the neural cell adhesion molecule CD56, a natural killer cell/stem cell antigen. Because CD56 expression has been associated with both extramedullary leukemia and multidrug resistance, we sought to correlate CD56 expression with treatment outcome in AML with t(8;21). Pretreatment leukemia cells from 29 adult de novo AML patients with t(8;21) treated on Cancer and Leukemia Group B (CALGB) protocols were immunophenotyped by multiparameter flow cytometry as part of a prospective immunophenotyping study of adult AML (CALGB 8361). CD56 was expressed in 16 cases (55%). There was no correlation between CD56 expression and age, sex, white blood cell count, granulocyte count, the presence of additional cytogenetic abnormalities, or the presence of extramedullary disease at diagnosis. The CR rate to standard-dose cytarabine and daunorubicin was similar for cases with and without CD56 expression (88% v 92%; P = 1.0). Post-CR therapy included at least one course of high-dose cytarabine in 24 of 26 patients who achieved CR; numbers of courses administered were similar in cases with and without CD56 expression. Although post-CR therapy did not differ, CR duration was significantly shorter in cases with CD56 expression compared with those without (median, 8.7 months v not reached; P = .01), as was survival (median, 16.5 months v not reached; P = .008). We conclude that CD56 expression in AML with t(8;21) is associated with significantly shorter CR duration and survival. Our results suggest that CD56 expression may be useful in stratifying therapy for this subtype of AML.     

A conservative theory for long-term reliability-growth prediction[of software]

This paper describes a different approach to software reliability growth modeling which enables long-term predictions. Using relatively common assumptions, it is shown that the average value of the failure rate of the program, after a particular use-time, t, is bounded by N/(e·t), where N is the initial number of faults. This is conservative since it places a worst-case bound on the reliability rather than making a best estimate. The predictions might be relatively insensitive to assumption violations over the longer term. The theory offers the potential for making long-term software reliability growth predictions based solely on prior estimates of the number of residual faults. The predicted bound appears to agree with a wide range of industrial and experimental reliability data. Less pessimistic results can be obtained if additional assumptions are made about the failure rate distribution of faults     

The reaction between water-soluble tree leaf constituents and ferric oxide in relation to podzolisatlon

Sterile aqueous extracts of tree leaves dissolve ferric oxide, and the reaction products are sorbed on residual ferric oxide. Extracts of autumn-fallen leaves and needles of oak, beech and larch, and picked Scots pine needles, were allowed to react with ferric oxide under conditions in which both the solution and sorption processes may be assumed to go to completion, and the effect on the composition of the extracts was determined. Under these conditions the net excess of solution of iron over sorption was quite small, and polyphenols, sugars, α-amino acids and carboxylic acids were retained on the ferric oxide.     

Ultrasound backscatter microscope analysis of mouse melanoma progression

The incidence and mortality rate of cutaneous melanoma continue to increase throughout the world, making the study of melanoma biology an important area of current research. While recent breakthroughs in transgenic mouse technology have led to promising mouse skin models of melanoma, there is presently no technique available for quantitatively studying subsurface melanoma progression, in vivo. We demonstrate the first application of an imaging method called ultrasound backscatter microscopy (UBM) for imaging early murine melanomas with spatial resolution of 30 microns axial and 60 microns lateral. Murine B16 F10 melanomas have been imaged from their earliest detection, over several days, until they are 2 to 5 mm in diameter. Melanoma dimensions measured by UBM were found to be in excellent agreement with those determined histopathologically on the excised tumours. The relative rms errors in UBM-determined melanoma height and width were found to be 8.7% and 4.2%, respectively. The mean rate of increase in tumour height of early murine melanoma was found to be 0.37 +/- 0.06 mm/day. Computer-generated volumetric renderings of melanomas have been produced from three-dimensional image data, allowing quantitative comparisons of tumour volumes to be made. Using a priori assumptions of ellipsoid tumour shape, the relative error in UBM-determined volume was shown to be less than 17%. These results should be of considerable interest to investigators studying melanoma biology using mouse skin models, and have implications in the use of high frequency ultrasound imaging for the clinical assessment of cutaneous melanoma.     

Programs as higher level subroutines

The subroutine call is one of the most fundamental of program control constructs. Despite this, it is rarely implemented at the job control or task level in existing commercially available software systems. When the feasibility of adding a general program calling mechanism to an existing system was investigated, it was apparent that there exist constraints on the amount of state information which could be saved on behalf of the calling program. A mechanism with low run-time overhead which saves a minimal amount of state information has proven to be easily integratable into a commercially available operating system. This mechanism has had a significant impact on the ease of development and support of large systems of programs. Examples of the use of the new calling mechanism include a program development system and a recursive directory manager for hierarchical directories.