A STUDY ON THE FEASIBILITY OF UNIVERSAL CHIP CONTROL IN MACHINING

A novel solution to the long standing issue of chip entanglement and breakage in metal cutting is presented in this dissertation. Through this work, an attempt is made to achieve universal chip control in machining by using chip guidance and subsequent breakage by backward bending (tensile loading of the chip's rough top surface) to effectively control long continuous chips into small segments. One big limitation of using chip breaker geometries in disposable carbide inserts is that the application range is limited to a narrow band depending on cutting conditions. Even within a recommended operating range, chip breakers do not function effectively as designed due to the inherent variations of the cutting process. Moreover, for a particular process, matching the chip breaker geometry with the right cutting conditions to achieve effective chip control is a very iterative process. The existence of a large variety of proprietary chip breaker designs further exacerbates the problem of easily implementing a robust and comprehensive chip control technique. To address the need for a robust and universal chip control technique, a new method is proposed in this work. By using a single tool top form geometry coupled with a tooling system for inducing chip breaking by backward bending, the proposed method achieves comprehensive chip control over a wide range of cutting conditions. A geometry based model is developed to predict a variable edge inclination angle that guides the chip flow to a predetermined target location. Chip kinematics for the new tool geometry is examined via photographic evidence from experimental cutting trials. Both qualitative and quantitative methods are used to characterize the chip kinematics. Results from the chip characterization studies indicate that the chip flow and final form show a remarkable consistency across multiple levels of workpiece and tool configurations as well as cutting conditions. A new tooling system is then designed to comprehensively break the chip by backward bending. Test results with the new tooling system prove that by utilizing the chip guidance and backward bending mechanism, long continuous chips can be more consistently broken into smaller segments that are generally deemed acceptable or good chips. It is found that the proposed tool can be applied effectively over a wider range of cutting conditions than present chip breakers thus taking possibly the first step towards achieving universal chip control in machining.

How well do radiographic absorptiometry and quantitative ultrasound predict osteoporosis at spine or hip? A cost-effectiveness analysis

Dual energy X-ray absorptiometry (DXA) is widely accepted as the reference method for diagnosis and monitoring of osteoporosis and for assessment of fracture risk, especially at hip. However, axial-DXA is not suitable for mass screening, because it is usually confined to specialized centers. We propose a two-step diagnostic approach to postmenopausal osteoporosis: the first step, using an inexpensive, widely available screening technique, aims at risk stratification in postmenopausal women; the second step, DXA of spine and hip is applied only to potentially osteoporotic women preselected on the basis of the screening measurement. In a group of 110 healthy postmenopausal woman, the capability of various peripheral bone measurement techniques to predict osteoporosis at spine and/or hip (T-score < -2.5SD using DXA) was tested using receiver operating characteristic (ROC) curves: radiographic absorptiometry of phalanges (RA), ultrasonometry at calcaneus (QUS. CALC), tibia (SOS.TIB), and phalanges (SOS.PHAL). Thirty-three women had osteoporosis at spine and/or hip with DXA. Areas under the ROC curves were 0.84 for RA, 0.83 for QUS.CALC, 0.77 for SOS.PHAL (p < 0.04 vs RA) and 0.74 for SOS.TIB (p < 0.02 vs RA and p = 0.05 vs QUS.CALC). For levels of sensitivity of 90%, the respective specificities were 67% (RA), 64% (QUS.CALC), 48% (SOS.PHAL), and 39% (SOS.TIB). In a cost-effective two-step, the price of the first step should not exceed 54% (RA), 51% (QUS.CALC), 42% (SOS.PHAL), and 25% (SOS.TIB). In conclusion, RA, QUS.CALC, SOS.PHAL, and SOS.TIB may be useful to preselect postmenopausal women in whom axial DXA is indicated to confirm/exclude osteoporosis at spine or hip.

Improving follow-up of abnormal cancer screens using electronic health records: trust but verify test result communication.

BACKGROUND: Early detection of colorectal cancer through timely follow-up of positive Fecal Occult Blood Tests (FOBTs) remains a challenge. In our previous work, we found 40% of positive FOBT results eligible for colonoscopy had no documented response by a treating clinician at two weeks despite procedures for electronic result notification. We determined if technical and/or workflow-related aspects of automated communication in the electronic health record could lead to the lack of response. METHODS: Using both qualitative and quantitative methods, we evaluated positive FOBT communication in the electronic health record of a large, urban facility between May 2008 and March 2009. We identified the source of test result communication breakdown, and developed an intervention to fix the problem. Explicit medical record reviews measured timely follow-up (defined as response within 30 days of positive FOBT) pre- and post-intervention. RESULTS: Data from 11 interviews and tracking information from 490 FOBT alerts revealed that the software intended to alert primary care practitioners (PCPs) of positive FOBT results was not configured correctly and over a third of positive FOBTs were not transmitted to PCPs. Upon correction of the technical problem, lack of timely follow-up decreased immediately from 29.9% to 5.4% (p<0.01) and was sustained at month 4 following the intervention. CONCLUSION: Electronic communication of positive FOBT results should be monitored to avoid limiting colorectal cancer screening benefits. Robust quality assurance and oversight systems are needed to achieve this. Our methods may be useful for others seeking to improve follow-up of FOBTs in their systems.

The role of substance abuse treatment in preventing human immunodeficiency virus transmission among injecting drug users

This exploratory study assesses the utility of substance abuse treatment as a strategy for preventing human immunodeficiency virus (HIV) transmission among injecting drug users (IDUs). Data analyzed in this study were collected in San Antonio, TX, 1989 through 1995 using both qualitative and quantitative methods. Qualitative data included ethnographic interviews with 234 active IDUs; quantitative data included baseline risk assessments and HIV screening plus interviews follow-up interviews administered approximately six months later to 823 IDUs participating in a Federally-funded AIDS community outreach demonstration project.^ Findings that have particularly important implications for substance abuse treatment as an HIV prevention strategy for IDUs are listed below. (1) IDUs who wanted treatment were significantly more likely to be daily heroin users. (2) IDUs who want treatment were significantly more likely to have been to treatment previously. (3) IDUs who wanted treatment at baseline reported significantly higher levels of HIV risk than IDUs who did not want treatment. (4) IDUs who went to treatment between their baseline and follow-up interviews reported significantly higher levels of HIV risk at baseline than IDUs who did not go to treatment. (5) IDUs who went to treatment between their baseline and follow-up interviews reported significantly greater decreases in injection-related HIV risk behaviors. (6) IDUs who went to treatment reported significantly greater decreases in sexual HIV risk behaviors than IDUs who did not go to treatment.^ This study also noted a number of factors that may limit the effectiveness of substance abuse treatment in reducing HIV risk among IDUs. Findings suggest that the impact of methadone maintenance on HIV risk behaviors among opioid dependent IDUs may be limited by the negative manner in which it is perceived by IDUs as well as other elements of society. One consequence of the negative perception of methadone maintenance held by many elements of society may be an unwillingness to provide public funding for an adequate number of methadone maintenance slots. Thus many IDUs who would be willing to enter methadone maintenance are unable to enter it and many IDUs who do enter it are forced to drop out prematurely. ^

Mouse models and quantitative trait loci of susceptibility to bleomycin- and radiation-induced pulmonary fibrosis

Radiotherapy involving the thoracic cavity and chemotherapy with the drug bleomycin are both dose limited by the development of pulmonary fibrosis. From evidence that there is variation in the population in susceptibility to pulmonary fibrosis, and animal data, it was hypothesized that individual variation in susceptibility to bleomycin-induced, or radiation-induced, pulmonary fibrosis is, in part, genetically controlled. In this thesis a three generation mouse genetic model of C57BL/6J (fibrosis prone) and C3Hf/Kam (fibrosis resistant) mouse strains and F1 and F2 (F1 intercross) progeny derived from the parental strains was developed to investigate the genetic basis of susceptibility to fibrosis. In the bleomycin studies the mice received 100 mg/kg (125 for females) of bleomycin, via mini osmotic pump. The animals were sacrificed at eight weeks following treatment or when their breathing rate indicated respiratory distress. In the radiation studies the mice were given a single dose of 14 or 16 Gy (Co$\sp{60})$ to the whole thorax and were sacrificed when moribund. The phenotype was defined as the percent of fibrosis area in the left lung as quantified with image analysis of histological sections. Quantitative trait loci (QTL) mapping was used to identify the chromosomal location of genes which contribute to susceptibility to bleomycin-induced pulmonary fibrosis in C57BL/6J mice compared to C3Hf/Kam mice and to determine if the QTL's which influence susceptibility to bleomycin-induced lung fibrosis in these progenitor strains could be implicated in susceptibility to radiation-induced lung fibrosis. For bleomycin, a genome wide scan revealed QTL's on chromosome 17, at the MHC, (LOD = 11.7 for males and 7.2 for females) accounting for approximately 21% of the phenotypic variance, and on chromosome 11 (LOD = 4.9), in male mice only, adding 8% of phenotypic variance. The bleomycin QTL on chromosome 17 was also implicated for susceptibility to radiation-induced fibrosis (LOD = 5.0) and contributes 7% of the phenotypic variance in the radiation study. In conclusion, susceptibility to both bleomycin-induced and radiation-induced pulmonary fibrosis are heritable traits, and are influenced by a genetic factor which maps to a genomic region containing the MHC. ^

Fatigue and sleep-disordered breathing in multiple sclerosis: a clinically relevant association?

Background. Fatigue in patients with multiple sclerosis (MS) is highly prevalent and severely impacts quality of life. Recent studies suggested that sleep-disordered breathing (SDB) significantly contributes to fatigue in MS. Study Objective. To evaluate the importance of routine respirography in MS patients with severe fatigue and to explore the effects of treatment with continuous positive airway pressure (CPAP). Patients and Methods. We prospectively assessed the presence of severe fatigue, as defined by a score of ≥5.0 on the Fatigue Severity Scale (FSS), in 258 consecutive MS patients. Ninety-seven patients (38%) suffered from severe fatigue, whereof 69 underwent overnight respirography. Results. We diagnosed SDB in 28 patients (41%). Male sex was the only independent associate of SDB severity (P = 0.003). CPAP therapy in 6 patients was associated with a significant reduction of FSS scores (5.8 ± 0.5 versus 4.8 ± 0.6, P = 0.04), but the scores remained pathological (≥4.0) in all patients. Conclusion. Respirography in MS patients with severe fatigue should be considered in daily medical practice, because SDB frequency is high and CPAP therapy reduces fatigue severity. However, future work is needed to understand the real impact of CPAP therapy on quality of life in this patient group.

More volunteers in football clubs. An evaluation of a method to increase the number of volunteers

An increasing number of clubs experience difficulties in recruiting and retaining sufficient numbers of volunteers to manage and staff their clubs (Lamprecht, Fischer, & Stamm, 2012). In order to facilitate volunteer recruitment, sport clubs need a specific strategy to recruit and retain volunteers for both formal positions and ad hoc tasks. Therefore, the intervention “More Volunteers in Football Clubs” was designed and its impact was evaluated in detail. The question this evaluation research wants to address is: Can football clubs recruit and retain volunteers successfully by implementing the intervention “More Volunteers in Football Clubs”? The designed intervention is based on the different expectations and needs of volunteers, as well as non-profit human resource management and organisational development management, with a strong emphasis on club-specific counseling and support. Task forces of the twelve participating football clubs attended four workshops in which they received tailor made counseling to reach the desired number of volunteers. The intervention has been implemented and its effectiveness tested in cooperation with the Swiss Football Federation with twelve Swiss football clubs following a pretest, intervention, posttest design Data have been gathered and analysed using a combination of qualitative and quantitative methods. Outcome measurements are: volunteer rate, number of recruited volunteers, number of filled volunteer positions and volunteer satisfaction. Four months after the intervention all clubs that completed the proposed intervention were successful in recruiting the desired number of volunteers. Further, all participating clubs found the intervention helpful and would recommend other clubs to participate as well. With the development of this practical intervention a solution for football clubs is provided to overcome the difficulties in recruiting and retaining sufficient numbers of volunteers. Lamprecht, M., Fischer, A., & Stamm, H.-P. (2012). Sportvereine in der Schweiz. Strukturen, Leistungen, Herausforderungen. Zürich, Switzerland: Seismo.

All-ceramic or metal-ceramic tooth-supported fixed dental prostheses (FDPs)? A systematic review of the survival and complication rates. Part II: Multiple-unit FDPs.

OBJECTIVE To assess the 5-year survival of metal-ceramic and all-ceramic tooth-supported fixed dental prostheses (FDPs) and to describe the incidence of biological, technical and esthetic complications. METHODS Medline (PubMed), Embase and Cochrane Central Register of Controlled Trials (CENTRAL) searches (2006-2013) were performed for clinical studies focusing on tooth-supported FDPs with a mean follow-up of at least 3 years. This was complemented by an additional hand search and the inclusion of 10 studies from a previous systematic review [1]. Survival and complication rates were analyzed using robust Poisson's regression models to obtain summary estimates of 5-year proportions. RESULTS Forty studies reporting on 1796 metal-ceramic and 1110 all-ceramic FDPs fulfilled the inclusion criteria. Meta-analysis of the included studies indicated an estimated 5-year survival rate of metal-ceramic FDPs of 94.4% (95% CI: 91.2-96.5%). The estimated survival rate of reinforced glass ceramic FDPs was 89.1% (95% CI: 80.4-94.0%), the survival rate of glass-infiltrated alumina FDPs was 86.2% (95% CI: 69.3-94.2%) and the survival rate of densely sintered zirconia FDPs was 90.4% (95% CI: 84.8-94.0%) in 5 years of function. Even though the survival rate of all-ceramic FDPs was lower than for metal-ceramic FDPs, the differences did not reach statistical significance except for the glass-infiltrated alumina FDPs (p=0.05). A significantly higher incidence of caries in abutment teeth was observed for densely sintered zirconia FDPs compared to metal-ceramic FDPs. Significantly more framework fractures were reported for reinforced glass ceramic FDPs (8.0%) and glass-infiltrated alumina FDPs (12.9%) compared to metal-ceramic FDPs (0.6%) and densely sintered zirconia FDPs (1.9%) in 5 years in function. However, the incidence of ceramic fractures and loss of retention was significantly (p=0.018 and 0.028 respectively) higher for densely sintered zirconia FDPs compared to all other types of FDPs. CONCLUSIONS Survival rates of all types of all-ceramic FDPs were lower than those reported for metal-ceramic FDPs. The incidence of framework fractures was significantly higher for reinforced glass ceramic FDPs and infiltrated glass ceramic FDPs, and the incidence for ceramic fractures and loss of retention was significantly higher for densely sintered zirconia FDPs compared to metal-ceramic FDPs.

Plant strengtheners enhance parasitoid attraction to herbivore-damaged cotton via qualitative and quantitative changes in induced volatiles

BACKGROUND Herbivore-damaged plants release a blend of volatile organic compounds (VOCs) that differs from undamaged plants. These induced changes are known to attract the natural enemies of the herbivores and therefore are expected to be important determinants of the effectiveness of biological control in agriculture. One way of boosting this phenomenon is the application of plant strengtheners, which has been shown to enhance parasitoid attraction in maize. It is unclear whether this is also the case for other important crops. RESULTS The plant strengtheners BTH [benzo (1,2,3) thiadiazole-7-carbothioic acid S-methyl ester] and laminarin were applied to cotton plants, and the effects on volatile releases and the attraction of three hymenopteran parasitoids, Cotesia marginiventris, Campoletis sonorensis and Microplitis rufiventris, were studied. After treated and untreated plants were induced by real or simulated caterpillar feeding, it was found that BTH treatment increased the attraction of the parasitoids, whereas laminarin had no significant effect. BTH treatment selectively increased the release of two homoterpenes and reduced the emission of indole, the latter of which had been shown to interfere with parasitoid attraction in earlier studies. Canonical variate analyses of the data show that the parasitoid responses were dependent on the quality rather than the quantity of volatile emission in this tritrophic interaction. CONCLUSION Overall, these results strengthen the emerging paradigm that induction of plant defences with chemical elicitors such as BTH could provide a sustainable and environmentally friendly strategy for biological control of pests by enhancing the attractiveness of cultivated plants to natural enemies of insect herbivores. © 2014 Society of Chemical Industry

People, protected areas and ecosystem services: a qualitative and quantitative analysis of local people's perception and preferences in Côte d'Ivoire

The long-term integrity of protected areas (PAs), and hence the maintenance of related ecosystem services (ES), are dependent on the support of local people. In the present study, local people's perceptions of ecosystem services from PAs and factors that govern local preferences for PAs are assessed. Fourteen study villages were randomly selected from three different protected forest areas and one control site along the southern coast of Côte d'Ivoire. Data was collected through a mixed-method approach, including qualitative semi-structured interviews and a household survey based on hypothetical choice scenarios. Local people's perceptions of ecosystem service provision was decrypted through qualitative content analysis, while the relation between people's preferences and potential factors that affect preferences were analyzed through multinomial models. This study shows that rural villagers do perceive a number of different ecosystem services as benefits from PAs in Côte d'Ivoire. The results based on quantitative data also suggest that local preferences for PAs and related ecosystem services are driven by PAs' management rules, age, and people's dependence on natural resources.