Dermophis oaxacae

Number of Pages: 2Integrative BiologyGeological Science

Calculus from the past: multiple delay systems arising in cancer cell modelling

Non-local calculus is often overlooked in the mathematics curriculum. In this paper we present an interesting new class of non-local problems that arise from modelling the growth and division of cells, especially cancer cells, as they progress through the cell cycle. The cellular biomass is assumed to be unstructured in size or position, and its evolution governed by a time-dependent system of ordinary differential equations with multiple time delays. The system is linear and taken to be autonomous. As a result, it is possible to reduce its solution to that of a nonlinear matrix eigenvalue problem. This method is illustrated by considering case studies, including the model of the cell cycle developed in Simms K, Bean N, & Koeber A. [10]. The paper concludes by explaining how asymptotic expressions for the distribution of cells across the compartments can be determined and used to assess the impact of different chemotherapeutic agents

Field Study for Remote Sensing: An instructor's manual

The need for and value of field work (surface truthing) in the verification of image identification from high atitude infrared and multispectral space sensor images are discussed in this handbook which presents guidelines for developing instructional and research procedures in remote sensing of the environment

Minascaecilia sartoria

Number of Pages: 1Integrative BiologyGeological Science

Gymnopis, G. multiplicata

Number of Pages: 2Integrative BiologyGeological Science

Constraining recent lead pollution sources in the North Pacific using ice core stable lead isotopes

Trends and sources of lead (Pb) aerosol pollution in the North Pacific rim of North America from 1850 to 2001 are investigated using a high-resolution (subannual to annual) ice core record recovered from Eclipse Icefield (3017 masl; St. Elias Mountains, Canada). Beginning in the early 1940s, increasing Pb concentration at Eclipse Icefield occurs coevally with anthropogenic Pb deposition in central Greenland, suggesting that North American Pb pollution may have been in part or wholly responsible in both regions. Isotopic ratios (208Pb/207Pb and 206Pb/207Pb) from 1970 to 2001 confirm that a portion of the Pb deposited at Eclipse Icefield is anthropogenic, and that it represents a variable mixture of East Asian (Chinese and Japanese) emissions transported eastward across the Pacific Ocean and a North American component resulting from transient meridional atmospheric flow. Based on comparison with source material Pb isotope ratios, Chinese and North American coal combustion have likely been the primary sources of Eclipse Icefield Pb over the 1970–2001 time period. The Eclipse Icefield Pb isotope composition also implies that the North Pacific mid-troposphere is not directly impacted by transpolar atmospheric flow from Europe. Annually averaged Pb concentrations in the Eclipse Icefield ice core record show no long-term trend during 1970–2001; however, increasing 208Pb/207Pb and decreasing 206Pb/207Pb ratios reflect the progressive East Asian industrialization and increase in Asian pollutant outflow. The post-1970 decrease in North American Pb emissions is likely necessary to explain the Eclipse Icefield Pb concentration time series. When compared with low (lichen) and high (Mt. Logan ice core) elevation Pb data, the Eclipse ice core record suggests a gradual increase in pollutant deposition and stronger trans-Pacific Asian contribution with rising elevation in the mountains of the North Pacific rim

Experimental demonstration of digital predistortion for orthogonal frequency-division multiplexing-radio over fibre links near laser resonance

Radio over fibre (RoF), an enabling technology for distribution of wireless broadband service signals through analogue optical links, suffers from non-linear distortion. Digital predistortion has been demonstrated as an effective approach to overcome the RoF non-linearity. However, questions remain as to how the approach performs close to laser resonance, a region of significant dynamic non-linearity, and how resilient the approach is to changes in input signal and link operating conditions. In this work, the performance of a digital predistortion approach is studied for directly modulated orthogonal frequency-division multiplexing RoF links operating from 2.47 to 3.7 GHz. It extends previous works to higher frequencies, and to higher quadrature amplitude modulation (QAM) levels. In addition, the resilience of the predistortion approach to changes in modulation level of QAM schemes, and average power levels are investigated, and a novel predistortion training approach is proposed and demonstrated. Both memoryless and memory polynomial predistorter models, and a simple off-line least-squares-based identification method, are used, with excellent performance improvements demonstrated up to 3.0 GHz

Preventing preschool mental health problems: Population-based cluster randomized controlled trial

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Objective Prevention of child behavior problems may reduce later mental health problems. We compared the effectiveness, at the population level, of an efficacious targeted prevention program alone or following a universal parenting program. Method Three arm, cluster randomized controlled trial. 1353 primary caregivers and healthy eight-month-old babies recruited July 2010 to January 2011 from well-child centers (randomization unit). Primary outcome: Child Behavior Checklist (CBCL) externalizing and internalizing scales* at child age three and 4.5 years. Secondary outcomes: Parenting Behavior Checklist* and over-involved/protective parenting (primary caregiver report). Secondary caregivers completed starred measures at age three. Results Retention was 76% and 77% at ages three and 4.5 years, respectively. At three years, intention-to-treat analyses found no statistically significant differences (adjusted mean difference (95% CI; p-value)) for externalizing (Targeted versus Usual Care -0.2 (-1.7 to 1.2; p= 0.76); Combined versus Usual Care 0.4 (-1.1 to 1.9; p=0.60)) or internalizing behavior problems (Targeted versus Usual Care 0.2 (-1.2 to 1.6; p= 0.76); Combined versus Usual Care 0.4 (-1.1 to 2.0; p=0.58)). Primary outcomes were similar at 4.5 years. At three years, primary and secondary caregivers reported less over-involved/protective parenting in both the Combined and Targeted versus Usual Care arm; secondary caregivers also reported less harsh discipline in the Combined and Targeted versus Usual Care arm. Mean program costs per family were $A218 (Targeted arm) and A$682 (Combined arm). Conclusion When translated to the population level by existing staff, pre-existing programs appeared ineffective in improving child behavior, alone or in combination, but improved parenting