Useful applications of earth-oriented satellites - Systems for remote-sensing information and distribution, panel 8

Problems and potential use of data gathered by remote sensing from satellites or aircraf

Supersonic crack propagation in a class of lattice models of Mode III brittle fracture

We study a lattice model for mode III crack propagation in brittle materials in a stripe geometry at constant applied stretching. Stiffening of the material at large deformation produces supersonic crack propagation. For large stretching the propagation is guided by well developed soliton waves. For low stretching, the crack-tip velocity has a universal dependence on stretching that can be obtained using a simple geometrical argument.Comment: 4 pages, 3 figure

AAPM medical physics practice guideline 10.a.: Scope of practice for clinical medical physics.

The American Association of Physicists in Medicine (AAPM) is a nonprofit professional society whose primary purposes are to advance the science, education, and professional practice of medical physics. The AAPM has more than 8000 members and is the principal organization of medical physicists in the United States. The AAPM will periodically define new practice guidelines for medical physics practice to help advance the science of medical physics and to improve the quality of service to patients throughout the United States. Existing medical physics practice guidelines will be reviewed for the purpose of revision or renewal, as appropriate, on their fifth anniversary or sooner. Each medical physics practice guideline (MPPG) represents a policy statement by the AAPM, has undergone a thorough consensus process in which it has been subjected to extensive review, and requires the approval of the Professional Council. The medical physics practice guidelines recognize that the safe and effective use of diagnostic and therapeutic radiation requires specific training, skills, and techniques as described in each document. As the review of the previous version of AAPM Professional Policy (PP)-17 (Scope of Practice) progressed, the writing group focused on one of the main goals: to have this document accepted by regulatory and accrediting bodies. After much discussion, it was decided that this goal would be better served through a MPPG. To further advance this goal, the text was updated to reflect the rationale and processes by which the activities in the scope of practice were identified and categorized. Lastly, the AAPM Professional Council believes that this document has benefitted from public comment which is part of the MPPG process but not the AAPM Professional Policy approval process. The following terms are used in the AAPM's MPPGs: Must and Must Not: Used to indicate that adherence to the recommendation is considered necessary to conform to this practice guideline. Should and Should Not: Used to indicate a prudent practice to which exceptions may occasionally be made in appropriate circumstances

Spalling uniaxial strength of Al2O3 at high strain rates

In this article research into the uniaxial tensile strength of Al2O3 monolithic ceramic is presented. The experimental procedure of the spalling of long bars is investigated from different approaches. This method is used to obtain the tensile strength at high strain rates under uniaxial conditions. Different methodologies proposed by several authors are used to obtain the tensile strength. The hypotheses needed for the experimental set-up are also checked, and the requirements of the set-up and the variables are also studied by means of numerical simulations. The research shows that the shape of the projectile is crucial to achieve successfully tests results. An experimental campaign has been carried out including high speed video and a digital image correlation system to obtain the tensile strength of alumina. Finally, a comparison of the test results provided by three different methods proposed by different authors is presented. The tensile strength obtained from the three such methods on the same specimens provides contrasting results. Mean values vary from one method to another but the trends are similar for two of the methods. The third method gives less scatter, though the mean values obtained are lower and do not follow the same trend as the other methods for the different specimens

Public health performance of sanitation technologies in Tamil Nadu, India: Initial perspectives based on E. coli release

Sanitation is intended to reduce the spread and burden of diseases transmitted from excreta. Pathogen reduction from excreta before sludge or effluent discharge to the environment would seem a logical and useful performance indicator for sanitation systems. However, the relative magnitudes of pathogen release from common sanitation technologies are not well understood. We, therefore, investigated the feasibility of performance measurement of different sanitation technologies in Tamil Nadu, India in reducing the release of the pathogen indicator Escherichia coli (E. coli). After conducting users’ surveys and technical assessments of the locally prevalent sanitation systems, we classified them into 7 distinct categories (based on both observed physical characteristic and usage) within a widely-accepted physical typology. Faecal sludge and wastewater samples were collected and analysed for E. coli and total solids from 136 household systems, 24 community systems, and 23 sanitary sewer oveflows. We estimated the average volumetric release rates of wastewater and faecal sludge from the different sanitation technologies. Average daily per capita E. coli release was computed, and used as one indicator of the public health performance of technologies. We found that on-site installations described by owners as “septic systems” included diverse forms of tanks and pits of uncertain performance. We observed a statistically significant difference in the average daily per capita E. coli release from different sanitation technologies (p = 0.00001). Pathogen release from the studied on-site sanitation technologies varied by as much as 5 orders of magnitude from “lined pits” (5.4 Log10 E. coli per person per day) to “overflowing sanitary sewers” and “direct discharge pipes” (10.3–10.5 Log10 E. coli per person per day). Other technologies lay between these extremes, and their performances in E. coli removal also varied significantly, in both statistical and practical terms. Our results suggest that although faecal sludge management along the sanitation service chain is important, sanitation planners of the observed systems (and probably elsewhere) should direct higher priority to proper management of the liquid effluents from these systems to minimize public health hazards. We conclude that (i) the work demonstrates a new and promising approach for estimating the public health performance of differing sanitation technologies, (ii) if E.coli is accepted as an indicator of the public health hazard of releases from sanitation systems, our results strongly suggest that safe containment of excreta for an extended period substantially reduces pathogen numbers and the risk of pathogen release into the environment; and (iii) there are some simple but little-used technical improvements to design and construction of on-site sanitation systems which could significantly reduce the release of pathogens to the environment

Development and evaluation of copper-67 and samarium-153 labeled conjugates for tumor radioimmunotherapy

The potential of utilizing receptor-specific agents such as monoclonal antibodies (MAb), and MAb-derived smaller molecules, as carriers of radionuclides for the selective destruction of tumors has stimulated much research activity. The success of such applications depends on many factors, especially the tumor binding properties of the antibody reagent, the efficiency of labeling and in-vivo stability of the radioconjugate and, on the careful choice of the radionuclide best suited to treat the tumor under consideration. The radiolabeled antibody technique for radioimmunotherapy (RIT), however, has experienced many limitations, and its success has not matched the expectations that were raised more than a decade ago. The problems that have been identified include: (i) degradation of antibody immunoreactivity resulting from chemical manipulations required for labeling; (ii) lack of suitable radioisotopes and methods for stable attachment of the radiolabel; (iii) in-vivo instability of the radioimmunoconjugates; (iv) excessive accumulation of activity in non-target locations; and (v) lack of radioimmunoconjugate accessibility to cells internal to a tumor mass. A careful choice of the radionuclide(s) best suited to treat the tumor under consideration is one of the most important requirements for successful radioimmunotherapy. This study evaluates copper 67 and samarium 153 for tumor radioimmunotherapy

A study of localisation in dual-phase high-strength steels under dynamic loading using digital image correlation and FE analysis

Tensile tests were conducted on dual-phase high-strength steel in a Split-Hopkinson Tension Bar at a strain-rate in the range of 150-600/s and in a servo-hydraulic testing machine at a strain-rate between 10-3 and 100/s. A novel specimen design was utilized for the Hopkinson bar tests of this sheet material. Digital image correlation was used together with high-speed photography to study strain localisation in the tensile specimens at high rates of strain. By using digital image correlation, it is possible to obtain in-plane displacement and strain fields during non-uniform deformation of the gauge section, and accordingly the strains associated with diffuse and localised necking may be determined. The full-field measurements in high strain-rate tests reveal that strain localisation started even before the maximum load was attained in the specimen. An elasto-viscoplastic constitutive model is used to predict the observed stress-strain behaviour and strain localisation for the dual-phase steel. Numerical simulations of dynamic tensile tests were performed using the non-linear explicit FE code LS-DYNA. Simulations were done with shell (plane stress) and brick elements. Good correlation between experiments and numerical predictions was achieved, in terms of engineering stress-strain behaviour, deformed geometry and strain fields. However, mesh density plays a role in the localisation of deformation in numerical simulations, particularly for the shell element analysis

The role of chemotherapeutic drugs in the evaluation of breast tumour response to chemotherapy using serial FDG-PET

INTRODUCTION: The aims of this study were to investigate whether drug sequence (docetaxel followed by anthracyclines or the drugs in reverse order) affects changes in the maximal standard uptake volume (SUVmax) on [18F]fluorodeoxyglucose positron emission tomography (FDG-PET) during neoadjuvant chemotherapy in women with locally advanced breast cancer. METHODS: Women were randomly assigned to receive either drug sequence, and FDG-PET scans were taken at baseline, after four cycles and after eight cycles of chemotherapy. Tumour response to chemotherapy was evaluated based on histology from a surgical specimen collected upon completion of chemotherapy. RESULTS: Sixty women were enrolled into the study. Thirty-one received docetaxel followed by anthracyclines (Arm A) and 29 received drugs in the reverse order (Arm B). Most women (83%) had ductal carcinoma and 10 women (17%) had lobular or lobular/ductal carcinoma. All but one tumour were downstaged during therapy. Overall, there was no significant difference in response between the two drug regimens. However, women in Arm B who achieved complete pathological response had mean FDG-PET SUVmax reduction of 87.7% after four cycles, in contrast to those who had no or minor pathological response. These women recorded mean SUVmax reductions of only 27% (P < 0.01). Women in Arm A showed no significant difference in SUVmax response according to pathological response. Sensitivity, specificity, accuracy and positive and negative predictive values were highest in women in Arm B. CONCLUSIONS: Our results show that SUVmax uptake by breast tumours during chemotherapy can be dependent on the drugs used. Care must be taken when interpreting FDG-PET in settings where patients receive varied drug protocols

The effect of a sports chiropractic manual therapy intervention on the prevention of back pain, hamstring and lower limb injuries in semi-elite Australian Rules footballers: a randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>Hamstring injuries are the most common injury in Australian Rules football. It was the aims to investigate whether a sports chiropractic manual therapy intervention protocol provided in addition to the current best practice management could prevent the occurrence of and weeks missed due to hamstring and other lower-limb injuries at the semi-elite level of Australian football.</p> <p>Methods</p> <p>Sixty male subjects were assessed for eligibility with 59 meeting entry requirements and randomly allocated to an intervention (n = 29) or control group (n = 30), being matched for age and hamstring injury history. Twenty-eight intervention and 29 control group participants completed the trial. Both groups received the current best practice medical and sports science management, which acted as the control. Additionally, the intervention group received a sports chiropractic intervention. Treatment for the intervention group was individually determined and could involve manipulation/mobilization and/or soft tissue therapies to the spine and extremity. Minimum scheduling was: 1 treatment per week for 6 weeks, 1 treatment per fortnight for 3 months, 1 treatment per month for the remainder of the season (3 months). The main outcome measure was an injury surveillance with a missed match injury definition.</p> <p>Results</p> <p>After 24 matches there was no statistical significant difference between the groups for the incidence of hamstring injury (OR:0.116, 95% CI:0.013-1.019, p = 0.051) and primary non-contact knee injury (OR:0.116, 95% CI:0.013-1.019, p = 0.051). The difference for primary lower-limb muscle strains was significant (OR:0.097, 95%CI:0.011-0.839, p = 0.025). There was no significant difference for weeks missed due to hamstring injury (4 v14, χ2:1.12, p = 0.29) and lower-limb muscle strains (4 v 21, χ2:2.66, p = 0.10). A significant difference in weeks missed due to non-contact knee injury was noted (1 v 24, χ2:6.70, p = 0.01).</p> <p>Conclusions</p> <p>This study demonstrated a trend towards lower limb injury prevention with a significant reduction in primary lower limb muscle strains and weeks missed due to non-contact knee injuries through the addition of a sports chiropractic intervention to the current best practice management.</p> <p>Trial registration</p> <p>The study was registered with the Australian and New Zealand Clinical Trials Registry (ACTRN12608000533392).</p