Controlling harmful cyanobacterial blooms in a world experiencing anthropogenic and climatic-induced change

Harmful (toxic, food web altering, hypoxia generating) cyanobacterial algal blooms (CyanoHABs) are proliferating world-wide due to anthropogenic nutrient enrichment, and they represent a serious threat to the use and sustainability of our freshwater resources. Traditionally, phosphorus (P) input reductions have been prescribed to control CyanoHABs, because P limitation is widespread and some CyanoHABs can fix atmospheric nitrogen (N₂) to satisfy their nitrogen (N) requirements. However, eutrophying systems are increasingly plagued with non N₂ fixing CyanoHABs that are N and P co-limited or even N limited. In many of these systems N loads are increasing faster than P loads. Therefore N and P input constraints are likely needed for long-term CyanoHAB control in such systems. Climatic changes, specifically warming, increased vertical stratification, salinization, and intensification of storms and droughts play additional, interactive roles in modulating CyanoHAB frequency, intensity, geographic distribution and duration. In addition to having to consider reductions in N and P inputs, water quality managers are in dire need of effective tools to break the synergy between nutrient loading and hydrologic regimes made more favorable for CyanoHABs by climate change. The more promising of these tools make affected waters less hospitable for CyanoHABs by 1) altering the hydrology to enhance vertical mixing and/or flushing and 2) decreasing nutrient fluxes from organic rich sediments by physically removing the sediments or capping sediments with clay. Effective future CyanoHAB management approaches must incorporate both N and P loading dynamics within the context of altered thermal and hydrologic regimes associated with climate change.     

Symbolic pixel labeling for curvilinear feature detection

This paper describes a method of detecting thin curvilinear features in an image based on a detailed analysis of the local gray level patterns at each pixel. This allows operations such as thinning and gap filling to be based on more accurate information.     

Delamination detection with carbon nanotube thread in self-sensing composite materials

Laminated composite materials can reach high mechanical properties at low weight. Composite materials, however, are susceptible to damage due to their low interlaminar mechanical properties and poor heat and charge transport in the transverse direction to the laminate. Moreover, methods to inspect and ensure the reliability of composites are expensive and labor intensive. Recently carbon nanotube forests were spun into thread that is tough and electrically conductive. The thread was integrated into composite materials and used for the first time as a sensor to monitor strains and detect damage including delamination in the material. These self-sensing composites were found to be very sensitive to damage and will help to revolutionize the maintenance of composite structures, which will now be based on their condition and not their amount of use.     

Thermal pasteurization of ready-to-eat foods and vegetables: Critical factors for process design and effects on quality

Increasing consumer desire for high quality ready-to-eat foods makes thermal pasteurization important to both food producers and researchers. To be in compliance with the Food Safety Modernization Act (FSMA), food companies seek regulatory and scientific guidelines to ensure that their products are safe. Clearly understanding the regulations for chilled or frozen foods is of fundamental importance to the design of thermal pasteurization processes for vegetables that meet food safety requirements. This article provides an overview of the current regulations and guidelines for pasteurization in the U.S. and in Europe for control of bacterial pathogens. Poorly understood viral pathogens, in terms of their survival in thermal treatments, are an increasing concern for both food safety regulators and scientists. New data on heat resistance of viruses in different foods are summarized. Food quality attributes are sensitive to thermal degradation. A review of thermal kinetics of inactivation of quality-related enzymes in vegetables and the effects of thermal pasteurization on vegetable quality is presented. The review also discusses shelf-life of thermally pasteurized vegetables.     

Micro- and macroreference frames: Specifying the relations between spatial categories in memory.

A substantial amount of research has demonstrated the importance of reference frames in organizing memory of object locations in both small and large environments. However, to date, little research has examined how the object locations represented in one reference frame are specified relative to object locations represented in another. In a series of 4 experiments, we demonstrate that multiple microreference frames can be established in memory for sets of objects that are spatially and semantically distinct, and that the spatial relations between these microreference frames are specified in memory by means of a more global, macroreference frame. Additionally, these experiments demonstrate that an established macroreference frame can influence which of several microreference frames will be coded in memory, but that a previously established microreference frame had no appreciable influence on the subsequent formation of a macroreference frame. These results are interpreted as indicating that the same cognitive mechanisms underlie interobject coding across multiple environmental scales. The implications for reference frame theories and theories positing hierarchical memory organization are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Validity and reliability of the Lesbian, Gay, Bisexual Working Alliance Self-Efficacy Scales.

In this paper, the authors report on the development and initial psychometric evaluation of the Lesbian, Gay, and Bisexual Working Alliance Self-Efficacy Scales (LGB-WASES) with data collected from two studies and 534 counseling trainees. Exploratory factor analysis results yielded a 32-item scale with a three-factor model (a) Emotional Bond, (b) Establishing Tasks, and (c) Setting Goals. LGB-WASES scores were internally consistent and remained stable over a 3-week period. Construct validity evidence suggests the LGB-WASES scores were (a) positively related to general perceptions of counseling self-efficacy and multicultural counseling competency, (b) negatively related to attitudes toward lesbians and gay men, and (d) unrelated to social desirability. Recommendations for future research are also discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of clays on the rheology of cement pastes

The fresh state of concrete is becoming increasingly important in furthering the types of applications of today's construction world. Processing techniques have resulted in technologies such as self-consolidating concrete and depend on the microstructural changes that take place during and immediately after mixing and placing. These changes to the microstructure reflect the flocculation behavior between the particles in suspension. The ability to modify this behavior allows control over the balance among flowability and shape-stability of concrete. This study investigates how clay admixtures affect the microstructure of cement pastes from a rheological stand point. Shear and compressive rheology techniques are used to measure how the solids volume fraction of suspensions with different admixtures evolves with stress. Based on these relationships, the effectiveness of clays on the balance between flowability and shape-stability is measured. Results are consistent with green strength tests performed on concrete mixes derived from the cement paste mixes.     

Sensor Network Localization,Euclidean Distance Matrix completions,and graph realization

We study Semidefinite Programming, SDP, relaxations for Sensor Network Localization, SNL, with anchors and with noisy distance information. The main point of the paper is to view SNL as a (nearest) Euclidean Distance Matrix, EDM, completion problem that does not distinguish between the anchors and the sensors. We show that there are advantages for using the well studied EDM model. In fact, the set of anchors simply corresponds to a given fixed clique for the graph of the EDM problem.     

Isolation of Ambient Particles of Known Critical Supersaturation: The Differential Activation Separator (DAS)

A field-deployable instrument has been developed that isolates from an ambient aerosol those particles that have critical supersaturations, S_c, within a narrow, user-specified, range. This Differential Activation Separator (DAS) consists of two continuous flow diffusion chambers housed within a single enclosure. Particles are introduced into the upstream chamber referred to as the CCN remover (CCNR) near the centerline between a warm, water-soaked, plate and a cool, continuously circulated, water bath. Those particles that activate at the resulting peak supersaturation, S_p, grow quickly and fall into the water bath. The remaining aerosol enters the second chamber referred to as the CCN separator (CCNS), which differs from the CCNR primarily in the use of a salt solution in the lower bath. The imposed temperature differential establishes an S_p slightly higher than that maintained in the upstream chamber, while the presence of a salt solution at the lower boundary results in a subsaturated region in roughly the lower half of the chamber. Those particles having (S_p)_CCNR < S _c < (S_p)_CCNS activate in this chamber and begin to fall due to gravitational settling. Before reaching the lower bath, the droplets evaporate in the subsaturated environment and continue to travel towards the chamber exit. The previously activated particles in the lower half of the chamber and the unactivated particles in the upper half are extracted in separate flows that are subsequently dried. Calibration of the DAS was achieved by measuring the size distribution of separated particles when a polydisperse ammonium sulfate aerosol was introduced.