Modeling Uptake and Translocation of Lead (PB) in Maize for the Purposes of Phytoextraction

Phytoextraction is a remediation technology that uses plants to remove heavy metals from soil. This technology has the potential to decrease the costs of remediating contaminated sites by several orders of magnitude compared to traditional technologies. To effectively implement this technology requires an understanding of the plant processes that control uptake and translocation of metals from the soil. Currently these processes are poorly understood, and especially so for Pb. The purpose of this thesis was to gain insights concerning the plant mechanisms that control uptake and translocation of Pb and how these mechanisms interact to control levels of Pb accumulation in the plant. This was accomplished by developing, testing, and implementing a system dynamics model that simulated a maize plant taking up and translocating Pb. As a result of a rigorous process of conceptualization, formulation, and testing, it appears that this model is a valid tool for studying uptake, translocation, and accumulation of Pb. The results suggest that precipitation of Pb as a Pb-phosphate at the root surface and throughout the plant is one of the most important mechanisms in this system. The maximal uptake rate of Pb (Vmax) and effective root mass may also be key plant parameters in this process. The model may also be used to test various phytoextraction management scenarios, two of which were tested in this study

PEAK MAGNITUDES OF DYNAMIC KNEE JOINT LOADING ARE NOT INFLUENCED BY CUSTOMISED BODY SEGMENT PARAMETERS

Although accurate body segment parameters (BSPs) do not appear to be important for peak joint moments recorded during walking, it is not clear whether joint moment magnitudes during highly dynamic activities can be modified when using individualised BSP data and having high frequency motion characteristics retained in the segmental acceleration data. Overall, it was found that BSPs had little influence on peak knee joint moment magnitudes during 45°cutting, drop jumping and fast running (even with high frequency signal components (up to 30 Hz) present in the dataset). This supports previous walking gait research that suggests BSPs have only a small effect on knee joint moment calculations

Cell patterning on photolithographically defined parylene-C:SiO2 substrates

Cell patterning platforms support broad research goals, such as construction of predefined in vitro neuronal networks and the exploration of certain central aspects of cellular physiology. To easily combine cell patterning with Multi-Electrode Arrays (MEAs) and silicon-based ‘lab on a chip’ technologies, a microfabrication-compatible protocol is required. We describe a method that utilizes deposition of the polymer parylene-C on SiO(2 )wafers. Photolithography enables accurate and reliable patterning of parylene-C at micron-level resolution. Subsequent activation by immersion in fetal bovine serum (or another specific activation solution) results in a substrate in which cultured cells adhere to, or are repulsed by, parylene or SiO(2) regions respectively. This technique has allowed patterning of a broad range of cell types (including primary murine hippocampal cells, HEK 293 cell line, human neuron-like teratocarcinoma cell line, primary murine cerebellar granule cells, and primary human glioma-derived stem-like cells). Interestingly, however, the platform is not universal; reflecting the importance of cell-specific adhesion molecules. This cell patterning process is cost effective, reliable, and importantly can be incorporated into standard microfabrication (chip manufacturing) protocols, paving the way for integration of microelectronic technology

Morbid obesity in women on the rise : an observational, population-based study

Background The obesity epidemic is generally monitored by the proportion of the population whose body mass index (BMI) exceeds 30 kg/m2 but this masks the growing proportion of those who are morbidly obese. This issue is important as the adverse health risks amplify as the level of obesity increases. The aim of this study was to determine how the prevalence of morbid obesity (BMI &gt;= 40.0 kg/m2) has changed over a decade among women living in south-eastern Australia.Methods BMI was determined for women in the Geelong Osteoporosis study (GOS) during two time periods, a decade apart. Height and weight were measured for 1,494 women (aged 20--94 years) during 1993--7 and for 1,076 women (aged 20--93 years), 2004--8, and the BMI calculated as weight in kilograms divided by the square of the height in metres (kg/m2). Prevalence estimates were age-standardised to enable direct comparisons.Results Mean BMI increased from 26.0 kg/m2 (95%CI 25.7-26.3) in 1993--7, to 27.1 kg/m2 (95%CI 26.8-27.4) in 2004--8. During this period, the prevalence of morbid obesity increased from 2.5% to 4.2% and the standardised morbidity ratio for morbid obesity was 1.69 (95%CI 1.26-2.27). Increases in mean BMI and prevalence of morbid obesity were observed for all ages and across the socioeconomic spectrum.Conclusions These findings reveal that over a decade, there has been an increase in mean BMI among women residing in south-eastern Australia, resulting in a measurable increase in the prevalence of morbid obesity.<br /

The Future of Clinical Trials of Myopia Control

In the field of myopia control, effective optical or pharmaceutical therapies are now available to patients in many markets. This creates challenges for the conduct of placebo-controlled, randomised clinical trials, including ethics, recruitment, retention, selective loss of faster progressors and non-protocol treatments: 1. Ethics: It is valid to question whether withholding treatment in control subjects is ethical. 2. Recruitment: Availability of treatments is making recruitment into clinical trials more difficult. 3. Retention: If masking is not possible, parents may immediately withdraw their child if randomised to no treatment. 4. Selective loss: Withdrawal of fast progressors in the control group leading to a control group biased towards low progression. 5. Non-protocol treatment: Parents may access other myopia treatments in addition to those within the trial. We propose that future trials may adopt one of the following designs: A Non-inferiority trials using an approved drug or device as the control. The choice will depend on whether a regulatory agency has approved the drug or device. B Short conventional efficacy trials where data are subsequently entered into a model created from previous clinical trials, which allows robust prediction of long-term treatment efficacy from the initial efficacy. C Virtual control group trials based on data relating to axial elongation, myopia progression or both, accounting for subject\u27s age and race. D Short-term control data from a cohort, for example, 1 year or less, and applying an appropriate, proportional annual reduction in axial elongation to that population and extrapolating to subsequent years. E Time-to- treatment- failure trials using survival analysis; once a treated or control subject progresses or elongates by a given amount, they exit the study and can be offered treatment. In summary, the future development of new treatments in myopia control will be hampered if significant changes are not made to the design of clinical trials in this area

A Mixed-Methods Investigation of Community Attachment in Rural Romania

This article explores the intricacies of community attachment using a multidimensional construct; attachment to the social and natural environment. A central focus is to assess whether attachment to the social and natural environment are distinctively predicted by length of residence, social interaction, and sociodemographic characteristics. Furthermore, this work elaborates on current understandings of community attachment by qualitatively exploring feelings of attachment toward the place of residence. All are explored in the context of rural Romania and communities managing the natural resources available to them. The results show the effect of several independent variables on attachment to social and natural environments. Residency was a stronger predictor of attachment to the social environment, while social interaction was a stronger predictor of attachment to the natural environment. Residents’ narratives underscored the importance, and interconnection, of the social and natural environment in defining feelings of local attachment. We conclude that community attachment is grounded in different facets of the locale that each play unique roles in shaping citizen perceptions

Long-term safety and efficacy of antithymocyte globulin induction: Use of integrated national registry data to achieve ten-year follow-up of 10-10 Study participants

BACKGROUND: Rabbit antithymocyte globulin (rATG, Thymoglobulin®) is the most common induction immunosuppression therapy in kidney transplantation. We applied a database integration strategy to capture and compare long-term (10-year) outcome data for US participants in a clinical trial of rATG versus FDA-approved basiliximab. METHODS: Records for US participants in an international, 1-year, randomized clinical trial comparing rATG and basiliximab induction in deceased donor kidney transplantation were integrated with records from the US national Organ Procurement and Transplantation (OPTN) registry using center, transplant dates, recipient sex, and birthdates. The OPTN captures center-reported acute rejection, graft failure, death, and cancer events, and incorporates comprehensive death records from the Social Security Death Master File. Ten-year outcomes according to randomized induction regimen were compared by Kaplan–Meier analysis (two-sided P). Non-inferiority of rATG was assessed using a one-tailed equivalence test (a-priori equivalence margins of 0–10 %). RESULTS: Of 183 US trial participants, 89 % (n = 163) matched OPTN records exactly; the remainder were matched by extending agreement windows for transplant and birthdates. Matches were validated by donor and recipient blood types. By Kaplan–Meier analysis, 10 years post-transplant, freedom from acute rejection, graft failure, or death was 32.6 % and 24.0 % in the rATG and basiliximab arms, respectively (P = 0.09). The incidence of acute rejection with rATG versus basiliximab induction was 21.0 % versus 32.8 % (P = 0.07). Patient survival (52.5 % versus 52.2 %, P = 0.92) and graft survival (34.3 % versus 30.9 %, P = 0.56) rates were numerically and statistically similar for both arms. Comparison of the composite outcome meets non-inferiority criteria even with a 0 % equivalence margin (one-sided P = 0.04). With a 10 % equivalence margin, the odds that rATG is no worse than basiliximab for 10-year risk of the composite endpoint are >99 %. CONCLUSIONS: Ten years post-transplant, rATG induction has comparable efficacy and safety to FDA-approved basiliximab. Integration of clinical trial records with national registry data can enable long-term monitoring of trial participants in transplantation, circumventing logistical and cost barriers of extended follow-up. TRIAL REGISTRATION: ClinicalTrials.gov NCT00235300 ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13063-015-0891-y) contains supplementary material, which is available to authorized users

The economic implications of HLA matching in cadaveric renal transplantation.

Abstract Background: The potential economic effects of the allocation of cadaveric kidneys on the basis of tissue-matching criteria are controversial. We analyzed the economic costs associated with the transplantation of cadaveric kidneys with various numbers of HLA mismatches and examined the potential economic benefits of a local, as compared with a national, system designed to minimize HLA mismatches between donor and recipient in first cadaveric renal transplantations. Methods: All data were supplied by the U.S. Renal Data System. Data on all payments made by Medicare from 1991 through 1997 for the care of recipients of a first cadaveric renal transplant were analyzed according to the number of HLA-A, B, and DR mismatches between donor and recipient and the duration of cold ischemia before transplantation. Results: Average Medicare payments for renal-transplant recipients in the three years after transplantation increased from $60,436 per patient for fully HLA-matched kidneys (those with no HLA-A, B, or DR mismatches) to$80,807 for kidneys with six HLA mismatches between donor and recipient, a difference of 34 percent (P\u3c0.001). By three years after transplantation, the average Medicare payments were $64,119 for transplantations of kidneys with less than 12 hours of cold-ischemia time and$74,997 for those with more than 36 hours (P\u3c0.001). In simulations, the assignment of cadaveric kidneys to recipients by a method that minimized HLA mismatching within a local geographic area (i.e., within one of the approximately 50 organ-procurement organizations, which cover widely varying geographic areas) produced the largest cost savings ($4,290 per patient over a period of three years) and the largest improvements in the graft-survival rate (2.3 percent) when the potential costs of longer cold-ischemia time were considered. Conclusions: Transplantation of better-matched cadaveric kidneys could have substantial economic advantages. In our simulations, HLA-based allocation of kidneys at the local level produced the largest estimated cost savings, when the duration of cold ischemia was taken into account. No additional savings were estimated to result from a national allocation program, because the additional costs of longer cold-ischemia time were greater than the advantages of optimizing HLA matching

Socioeconomic status, obesity and lifestyle in men : the Geelong Osteoporosis Study

Background : Although the association between lower socioeconomic status (SES) and obesity in women in developed countries is well-documented, current evidence regarding the relationship between obesity in men and area-based SES (equivalised for advantage and disadvantage) is inconsistent. Therefore, we aimed to examine obesity, lifestyle behaviours, physical activity in different domains and demographics in men using area-based SES.Methods : We performed a descriptive cross-sectional study of 1467 randomly selected white men (mean age 56 year (inter-quartile range (IQR) = 39&ndash;73 year)) recruited from the Barwon Statistical Division, South Western Victoria, Australia between 2001&ndash;06.Results : Age-adjusted BMI, waist circumference, % fat and lean mass and blood pressure were inversely associated with SES, with differences between low and upper SES (P for difference &lt;0.05), independent of country of birth. Age-adjusted lifestyle behaviours associated with obesity and/or adverse health (especially cardiovascular disease), were also associated with lower SES.Conclusions : Subjects from lower SES had greater measures of obesity despite being more physically active at work, but were less likely to be physically active in the domains of sports and/or leisure. These findings suggest the possible influence of lifestyle behaviours and occupation upon obesity in men and should be investigated further.<br /