Automated, objective texture segmentation of multibeam echosounder data - Seafloor survey and substrate maps from James Island to Ozette Lake, Washington Outer Coast

Without knowledge of basic seafloor characteristics, the ability to address any number of critical marine and/or coastal management issues is diminished. For example, management and conservation of essential fish habitat (EFH), a requirement mandated by federally guided fishery management plans (FMPs), requires among other things a description of habitats for federally managed species. Although the list of attributes important to habitat are numerous, the ability to efficiently and effectively describe many, and especially at the scales required, does not exist with the tools currently available. However, several characteristics of seafloor morphology are readily obtainable at multiple scales and can serve as useful descriptors of habitat. Recent advancements in acoustic technology, such as multibeam echosounding (MBES), can provide remote indication of surficial sediment properties such as texture, hardness, or roughness, and further permit highly detailed renderings of seafloor morphology. With acoustic-based surveys providing a relatively efficient method for data acquisition, there exists a need for efficient and reproducible automated segmentation routines to process the data. Using MBES data collected by the Olympic Coast National Marine Sanctuary (OCNMS), and through a contracted seafloor survey, we expanded on the techniques of Cutter et al. (2003) to describe an objective repeatable process that uses parameterized local Fourier histogram (LFH) texture features to automate segmentation of surficial sediments from acoustic imagery using a maximum likelihood decision rule. Sonar signatures and classification performance were evaluated using video imagery obtained from a towed camera sled. Segmented raster images were converted to polygon features and attributed using a hierarchical deep-water marine benthic classification scheme (Greene et al. 1999) for use in a geographical information system (GIS). (PDF contains 41 pages.

Microwave Characterization of Polymeric Microparticle Morphology

Biological cell function and overall health are highly defined by the cell’s morphology. Sorting cells based on their shape is recently a major interest to the biomedical field for the future of medical treatments and health diagnostics. This work presents a new shape-based particle sorting technique using a novel microwave sensing system as a step toward biological cell sorting. The new sensing system consists of a grounded coplanar waveguide (GCPW) transmission line that simultaneously serves as a single-particle microfluidic channel and a microwave sensor, which is paired with a microwave interferometer to boost signal-to-noise ratio (SNR). Polystyrene microspheres, a common organic polymer, are differentiated into different aspect ratios (ARs) using a custom stretching technique to simulate non-spherical biological cells, ideal for isolating volume-effects on the microwave signal due to the low coefficient of variation (CV \u3c 2%) of particle size. Although some microwave measurement data suggests the signal is dependent on microparticle shape, more data points and a machine learning algorithm is needed. The GCPW sensor demonstrates a previously-unattainable level of sensitivity. An early investigation into the effects of orientation of elongated particles on the microwave signal is also explored, as well as the design of an improved GCPW sensor

On the potential for extinction by Muller's Ratchet in Caenorhabditis elegans

<p>Abstract</p> <p>Background</p> <p>The self-fertile hermaphrodite worm <it>C. elegans </it>is an important model organism for biology, yet little is known about the origin and persistence of the self-fertilizing mode of reproduction in this lineage. Recent work has demonstrated an extraordinary degree of selfing combined with a high deleterious mutation rate in contemporary populations. These observations raise the question as to whether the mutation load might rise to such a degree as to eventually threaten the species with extinction. The potential for such a process to occur would inform our understanding of the time since the origin of self-fertilization in <it>C. elegans </it>history.</p> <p>Results</p> <p>To address this issue, here we quantify the rate of fitness decline expected to occur via Muller's ratchet for a purely selfing population, using both analytical approximations and globally distributed individual-based simulations from the evolution@home system to compute the rate of deleterious mutation accumulation. Using the best available estimates for parameters of how <it>C. elegans </it>evolves, we conclude that pure selfing can persist for only short evolutionary intervals, and is expected to lead to extinction within thousands of years for a plausible portion of parameter space. Credible lower-bound estimates of nuclear mutation rates do not extend the expected time to extinction much beyond a million years.</p> <p>Conclusion</p> <p>Thus we conclude that either the extreme self-fertilization implied by current patterns of genetic variation in <it>C. elegans </it>arose relatively recently or that low levels of outcrossing and other factors are key to the persistence of <it>C. elegans </it>into the present day. We also discuss results for the mitochondrial genome and the implications for <it>C. briggsae</it>, a close relative that made the transition to selfing independently of <it>C. elegans</it>.</p

Late results of surgical and medical therapy for patients with coronary artery disease and depressed left ventricular function

Late survival and freedom from myocardial infarction were determined for 192 patients with coronary artery disease and depressed left ventricular ejection fraction at rest (<35%) determined by biplane angiography who were evaluated between 1970 and 1977. Seventy-seven patients had coronary artery bypass grafting and 115 patients were treated medically and were considered surgical candidates. The medical and surgical groups were comparable in all baseline characteristics examined except frequency of three vessel disease and angina pectoris, which occurred in a significantly greater percent of the surgically treated patients (p < 0.01). Only three medically treated patients (2.6%) underwent coronary bypass grafting in the follow-up period.Seven year actuarial survival was 63% in the surgical and 34% in the medical group (p < 0.001). Ninety-three percent of patients in the surgical group and 81% of those in the medical group were free of nonfatal myocardial infarction (p = 0.01), and 62 and 33%, respectively, were alive and free of myocardial infarction (p < 0.001) at 7 years. Significant differences in survival favoring surgical treatment were observed for the subsets of patients with an ejection fraction of 25% or less (p = 0.0002) and 26 to 35% (p = 0.01), and for the subsets with three vessel coronary disease (p < 0.001), normal left ventricular end-diastolic volume (<100 ml/m2) (p = 0.005) and elevated end-diastolic volume (>100 ml/m2)(p = 0.001). After adjustment for other important prognostic variables, the type of treatment remained significant in predicting the relative risk (medical to surgical) of mortality at 5 and 7 years (2.58 and 2.12, respectively).These data corroborate the trends observed in several randomized trials of medical and surgical therapy in patients with abnormal left ventricular function. If hospital mortality for coronary artery bypass grafting is less than 5%, substantial benefit can be anticipated for the majority of patients with depressed ventricular function

Impacts of Forest Management Activities on Selected Hardwood Wood Quality Attributes: A Review

Hardwoods are increasingly being viewed as an important raw material component of the forest products industry, and this has spurred awareness of the impact of forest management on tree and wood quality. The impacts of various forest management activities on tree and wood quality in hardwoods are presented from the standpoint of the activities themselves rather than that of the wood properties. These silvicultural activities include genetic manipulation, intensive culture, fertilization and/or irrigation, pruning, thinning, weed control, and prescribed fire. A broad literature cited section is included as an aid to future scientists

Genetically Distinct Behavioral Modules Underlie Natural Variation in Thermal Performance Curves

Thermal reaction norms pervade organismal traits as stereotyped responses to temperature, a fundamental environmental input into sensory and physiological systems. Locomotory behavior represents an especially plastic read-out of animal response, with its dynamic dependence on environmental stimuli presenting a challenge for analysis and for understanding the genomic architecture of heritable variation. Here we characterize behavioral reaction norms as thermal performance curves for the nematode Caenorhabditis briggsae, using a collection of 23 wild isolate genotypes and 153 recombinant inbred lines to quantify the extent of genetic and plastic variation in locomotory behavior to temperature changes. By reducing the dimensionality of the multivariate phenotypic response with a function-valued trait framework, we identified genetically distinct behavioral modules that contribute to the heritable variation in the emergent overall behavioral thermal performance curve. Quantitative trait locus mapping isolated regions on Chromosome II associated with locomotory activity at benign temperatures and Chromosome V loci related to distinct aspects of sensitivity to high temperatures, with each quantitative trait locus explaining up to 28% of trait variation. These findings highlight how behavioral responses to environmental inputs as thermal reaction norms can evolve through independent changes to genetically distinct modular components of such complex phenotypes

Research Notes: University of Wisconsin

Tissue culture methods may benefit soybean breeders if whole plants can be differentiated from aneuploid, mutated, fused, or haploid cells. However, in order to realize this potential, it must be possible to derive plantlets from previously undifferentiated tissues - and ultimately from masses of callus cells. This report summarizes the information we obtained concerning adventitious budding from soybean tissues (Kimball and Bingham, 1973), early stages of embryo formation within masses of callus cells, and actual differentiation of plantlets from callus tissue

A systematic review of climate change education: giving children and young people a ‘voice’ and a ‘hand’ in redressing climate change

The reality of anthropogenic climate change has been established ‘beyond reasonable doubt’ by leading scientists worldwide. Applying a systematic literature review process, we analysed existing literature from 1993 to 2014 regarding climate change education for children and young people, with the aim of identifying key areas for further research. While a number of studies have indicated that young people’s understandings of climate change are generally limited, erroneous and highly influenced by mass media, other studies suggest that didactic approaches to climate change education have been largely ineffectual in affecting students’ attitudes and behaviour. The review identifies the need for participatory, interdisciplinary, creative, and affect-driven approaches to climate change education, which to date have been largely missing from the literature. In conclusion, we call for the development of new forms of climate change education that directly involve young people in responding to the scientific, social, ethical, and political complexities of climate change