279 research outputs found
Autonomous space processor for orbital debris
This work continues to develop advanced designs toward the ultimate goal of a GETAWAY SPECIAL to demonstrate economical removal of orbital debris utilizing local resources in orbit. The fundamental technical feasibility was demonstrated last year through theoretical calculations, quantitative computer animation, a solar focal point cutter, a robotic arm design and a subscale model. During this reporting period, several improvements are made in the solar cutter, such as auto track capabilities, better quality reflectors and a more versatile framework. The major advance has been in the design, fabrication and working demonstration of a ROBOTIC ARM that has several degrees of freedom. The functions were specifically tailored for the orbital debris handling. These advances are discussed here. Also a small fraction of the resources were allocated towards research in flame augmentation in SCRAMJETS for the NASP. Here, the fundamental advance was the attainment of Mach numbers up to 0.6 in the flame zone and a vastly improved injection system; the current work is expected to achieve supersonic combustion in the laboratory and an advanced monitoring system
Spillover Effects in Disclosure-Related Securities Litigation
Securities litigation is relatively rare but can significantly affect sued firms. We extend this research by examining the spillover effect of securities litigation on industry peers using a sample of disclosure-related litigation—distinct from events such as restatements and SEC enforcement. We find investors respond immediately as peers exhibit negative abnormal returns before and after case filings. Additionally, peers provide more voluntary earnings and sales forecasts. Notably, investors and peers respond primarily to cases that eventually settle, where litigation costs are concentrated. Further, disclosure results are concentrated in growth firms, where voluntary disclosure is most important, and in low litigation industries, where litigation is more noteworthy. Peers also adjust attributes of mandatory disclosures: disclosures become shorter, more readable, and contain fewer litigation-related terms. These changes appear successful as peers have lower future litigation incidence. Collectively, our findings indicate securities litigation has significant effects beyond the firms that directly face litigation
Short-term acclimation in adults does not predict offspring acclimation potential to hypoxia
Abstract The prevalence of hypoxic areas in coastal waters is predicted to increase and lead to reduced biodiversity. While the adult stages of many estuarine invertebrates can cope with short periods of hypoxia, it remains unclear whether that ability is present if animals are bred and reared under chronic hypoxia. We firstly investigated the effect of moderate, short-term environmental hypoxia (40% air saturation for one week) on metabolic performance in adults of an estuarine amphipod, and the fitness consequences of prolonged exposure. We then reared the offspring of hypoxia-exposed parents under hypoxia, and assessed their oxyregulatory ability under declining oxygen tensions as juveniles and adults. Adults from the parental generation were able to acclimate their metabolism to hypoxia after one week, employing mechanisms typically associated with prolonged exposure. Their progeny, however, did not develop the adult pattern of respiratory regulation when reared under chronic hypoxia, but instead exhibited a poorer oxyregulatory ability than their parents. We conclude that species apparently hypoxia-tolerant when tested in short-term experiments, could be physiologically compromised as adults if they develop under hypoxia. Consequently, we propose that the increased prevalence of hypoxia in coastal regions will have marked effects in some species currently considered hypoxia tolerant
Associations of Starch Gel Hardness, Granule Size, Waxy Allelic Expression, Thermal Pasting, Milling Quality, and Kernel Texture of 12 Soft Wheat Cultivars
Starches were isolated from 12 soft wheat (Triticum aestivum L.) cultivars and were characterized for waxy (Wx) allelic expression, thermal pasting characteristics, and starch granule size. Gels were produced from the thermally degraded starches and were evaluated using large deformation rheological measurements. Data were compared with cultivar kernel texture, milling characteristics, starch chemical analyses, and flour pasting characteristics. Larger flour yields were produced from cultivars that had larger starch granules. Flour yield also was correlated with lower amylose content and greater starch content. Harder starch gels were correlated with higher levels of amylose content and softer kernel texture. The cultivar Fillmore, which had a partial waxy mutation at the B locus, produced the highest peak pasting viscosity and the lowest gel hardness. Softer textured wheats had greater lipid‐complexed amylose and starch phosphorus contents and had less total starch content. Among these wheats of the soft market class, softer textured wheats had larger starch granules and harder textured wheats had smaller starch granules. In part, this may explain why soft wheats vary in texture. The smaller granules have larger surface area available for noncovalent bonding with the endosperm protein matrix and they also may pack more efficiently, producing harder endosperm.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141588/1/cche0163.pd
Climate Change Effects on Fishes
Fishes comprise the most diverse group of aquatic vertebrates and are found across the world’s aquatic biomes and ecosystems — in freshwater, estuaries, as well as in the ocean. With this diversity also comes an extensive array of life histories, behaviors, physiologies, and adaptations. In addition to long-term direct human perturbations on fish populations and communities, such as overfishing, habitat destruction, and aquatic pollution, indirect human stressors such as various climate change stressors are now increasingly having an impact on many fish species as well. It is predicted that climate change stressors such as warming, acidification, and hypoxia will alter fish biodiversity, change their geographic distributions, alter their fitness and performance, and create novel community structures. Due to their rich diversity, it is difficult to predict how each fish species will respond to the interplay of various climate stressors. However, fish species can often be classified into guilds, functional groups, life history strategies, etc., based on various traits. As such, some generalizable patterns may emerge on how specific (taxonomic/functional) groups of fish species might respond to current and future climate change. This bibliography covers key studies on climate change effects on (predominantly marine) fishes, through the lens of fish ecology. It assesses the current published literature in terms of various research fields in fish ecology, scaling up from cellular, individual, and population levels to higher levels of biological organization such as communities, ecosystems, and biogeographies. Such a broad bibliography might provide for a better appreciation of the complexity of studying climate change impacts on fishes, as their ecology is intertwined with that of many other species, habitats, and environmental drivers. The ecological responses of fishes at multiple levels of biological organization mediate their fitness, performance, and persistence, and generalizable insights are needed for their biodiversity conservation, and to evaluate their importance for various ecosystem services, including fisheries.</p
Coastal Ocean Processes : a science prospectus
CoOP (Coastal Ocean Processes) is an organization meant to study major interdisciplinary scientific
problems in the coastal ocean. Its goal is "to obtain a new level of quantitative understanding of the processes
that dominate the transformations, transport and fates of biologically, chemically and geologically important matter on the continental margin". Central to obtaining this understanding will be advances in observing and
modeling the cross-shelf component of transport. More specific objectives are to understand 1) cross-margin
exchanges, 2) air sea exchanges, 3) benthic-pelagic exchanges, 4) terrestrial inputs and 5) biological and
chemical transformations within the water column. CoOP research will be carried out primarly through a
series of process-oriented field studies, each involving about two years of measurements. Each of these field
studies is to be initiated and defined through a community workshop. In addition to the process studies, CoOP
will also involve modeling, long time series, exploratory studies, remote sensing, technological innovation, data
archiving and communications. A CoOP pilot study has been approved for funding by the National Science
Foundation, and funding will begin in 1992. The CoOP science effort is thus already underway.Funding was provided by the National Science Foundation under
Grant No. OCE-9108993
Evaluation of Textural and Sensory Properties on Typical Spanish Small Cakes Designed Using Alternative Flours
[EN] The objective of this study was to evaluate the effect of wheat flour substitution with toasted corn, quinoa, and sorghum flours on the overall perception and texture of typical Spanish small cakes
named madeleine. In order to evaluate these characteristics, a texture profile analysis (TPA) and a sensory analysis were carried out.
TPA showed that the replacement of wheat flour by sorghum flour did not affect significantly texture parameters of cakes. Hedonic sensory tests were also conducted revealing that the cake prepared
with sorghum flour was highly appreciated by the consumers as it got scores similar to traditional cakes made with wheat flour.Casas Moreno, MDM.; Barreto Palacios, VJ.; González Carrascosa, R.; Iborra Bernad, MDC.; Andrés Bello, MD.; Martínez Monzó, J.; García-Segovia, P. (2015). Evaluation of Textural and Sensory Properties on Typical Spanish Small Cakes Designed Using Alternative Flours. Journal of Culinary Science and Technology. 13(1):19-28. doi:10.1080/15428052.2014.952475S1928131Baldwin, R. R., Baldry, R. P., & Johansen, R. G. (1972). Fat systems for bakery products. Journal of the American Oil Chemists’ Society, 49(8), 473-477. doi:10.1007/bf02582482Beleia, A., Miller, R. A., & Hoseney, R. C. (1996). Starch Gelatinization in Sugar Solutions. Starch - Starke, 48(7-8), 259-262. doi:10.1002/star.19960480705Brannan, G. L., Setser, C. S., Kemp, K. E., Seib, P. A., & Roozeboom, K. (2001). Sensory Characteristics of Grain Sorghum Hybrids with Potential for Use in Human Food. Cereal Chemistry Journal, 78(6), 693-700. doi:10.1094/cchem.2001.78.6.693Cauvain, S. P., & Young, L. S. (Eds.). (2006). Baked Products. doi:10.1002/9780470995907Chieh, C. (s. f.). Water. Bakery Products, 211-232. doi:10.1002/9780470277553.ch11Conforti, F. D. (s. f.). Cake Manufacture. Bakery Products, 393-410. doi:10.1002/9780470277553.ch22Ghotra, B. S., Dyal, S. D., & Narine, S. S. (2002). Lipid shortenings: a review. Food Research International, 35(10), 1015-1048. doi:10.1016/s0963-9969(02)00163-1Kiosseoglou, V., & Paraskevopoulou, A. (s. f.). Eggs. Bakery Products, 161-172. doi:10.1002/9780470277553.ch8Lai, H.-M., & Lin, T.-C. (s. f.). Bakery Products: Science and Technology. Bakery Products, 3-68. doi:10.1002/9780470277553.ch1Lau, M. ., Tang, J., & Paulson, A. . (2000). Texture profile and turbidity of gellan/gelatin mixed gels. Food Research International, 33(8), 665-671. doi:10.1016/s0963-9969(00)00111-3LINDLEY, M. G. (1987). Sucrose in baked products. Nutrition Bulletin, 12(1), 41-45. doi:10.1111/j.1467-3010.1987.tb00011.xMastromatteo, M., Chillo, S., Iannetti, M., Civica, V., & Del Nobile, M. A. (2011). Formulation optimisation of gluten-free functional spaghetti based on quinoa, maize and soy flours. International Journal of Food Science & Technology, 46(6), 1201-1208. doi:10.1111/j.1365-2621.2011.02613.xOreopoulou, V. (s. f.). Fat Replacers. Bakery Products, 193-210. doi:10.1002/9780470277553.ch10Peressini, D., Pin, M., & Sensidoni, A. (2011). Rheology and breadmaking performance of rice-buckwheat batters supplemented with hydrocolloids. Food Hydrocolloids, 25(3), 340-349. doi:10.1016/j.foodhyd.2010.06.012Sanz, T., Salvador, A., Baixauli, R., & Fiszman, S. M. (2009). Evaluation of four types of resistant starch in muffins. II. Effects in texture, colour and consumer response. European Food Research and Technology, 229(2), 197-204. doi:10.1007/s00217-009-1040-1Taylor, J. R. N., Schober, T. J., & Bean, S. R. (2006). Novel food and non-food uses for sorghum and millets. Journal of Cereal Science, 44(3), 252-271. doi:10.1016/j.jcs.2006.06.009Wilderjans, E., Luyts, A., Brijs, K., & Delcour, J. A. (2013). Ingredient functionality in batter type cake making. Trends in Food Science & Technology, 30(1), 6-15. doi:10.1016/j.tifs.2013.01.001Wilderjans, E., Pareyt, B., Goesaert, H., Brijs, K., & Delcour, J. A. (2008). The role of gluten in a pound cake system: A model approach based on gluten–starch blends. Food Chemistry, 110(4), 909-915. doi:10.1016/j.foodchem.2008.02.079Wilson, N. L. W. (2011). How the Cookie Crumbles: A Case Study of Gluten-Free Cookies and Random Utility. American Journal of Agricultural Economics, 94(2), 576-582. doi:10.1093/ajae/aar081Zhu, J.-H., Yang, X.-Q., Ahmad, I., Li, L., Wang, X.-Y., & Liu, C. (2008). Rheological properties of κ-carrageenan and soybean glycinin mixed gels. Food Research International, 41(3), 219-228. doi:10.1016/j.foodres.2007.11.00
Mycoplasma genitalium: an efficient strategy to generate genetic variation from a minimal genome
Mycoplasma genitalium, a human pathogen associated with sexually transmitted diseases, is unique in that it has smallest genome of any known free-living organism. The goal of this study was to investigate if and how M. genitalium uses a minimal genome to generate genetic variations. We analysed the sequence variability of the third gene (MG192 or mgpC) of the M. genitalium MgPa adhesion operon, demonstrated that the MG192 gene is highly variable among and within M. genitalium strains in vitro and in vivo, and identified MG192 sequence shifts in the course of in vitro passage of the G37 type strain and in sequential specimens from an M. genitalium-infected patient. In order to establish the origin of the MG192 variants, we examined nine genomic loci containing partial copies of the MgPa operon, known as MgPar sequences. Our analysis suggests that the MG192 sequence variation is achieved by recombination between the MG192 expression site and MgPar sequences via gene cross-over and, possibly, also by gene conversion. It appears plausible that M. genitalium has the ability to generate unlimited variants from its minimized genome, which presumably allows the organism to adapt to diverse environments and/or to evade host defences by antigenic variation
Anticipating and Adapting to the Future Impacts of Climate Change on the Health, Security and Welfare of Low Elevation Coastal Zone (LECZ) Communities in Southeastern USA
Low elevation coastal zones (LECZ) are extensive throughout the southeastern United States. LECZ communities are threatened by inundation from sea level rise, storm surge, wetland degradation, land subsidence, and hydrological flooding. Communication among scientists, stakeholders, policy makers and minority and poor residents must improve. We must predict processes spanning the ecological, physical, social, and health sciences. Communities need to address linkages of (1) human and socioeconomic vulnerabilities; (2) public health and safety; (3) economic concerns; (4) land loss; (5) wetland threats; and (6) coastal inundation. Essential capabilities must include a network to assemble and distribute data and model code to assess risk and its causes, support adaptive management, and improve the resiliency of communities. Better communication of information and understanding among residents and officials is essential. Here we review recent background literature on these matters and offer recommendations for integrating natural and social sciences. We advocate for a cyber-network of scientists, modelers, engineers, educators, and stakeholders from academia, federal state and local agencies, non-governmental organizations, residents, and the private sector. Our vision is to enhance future resilience of LECZ communities by offering approaches to mitigate hazards to human health, safety and welfare and reduce impacts to coastal residents and industries
High-Resolution Positional Tracking for Long-Term Analysis of Drosophila Sleep and Locomotion Using the “Tracker” Program
Drosophila melanogaster has been used for decades in the study of circadian behavior, and more recently has become a popular model for the study of sleep. The classic method for monitoring fly activity involves counting the number of infrared beam crosses in individual small glass tubes. Incident recording methods such as this can measure gross locomotor activity, but they are unable to provide details about where the fly is located in space and do not detect small movements (i.e. anything less than half the enclosure size), which could lead to an overestimation of sleep and an inaccurate report of the behavior of the fly. This is especially problematic if the fly is awake, but is not moving distances that span the enclosure. Similarly, locomotor deficiencies could be incorrectly classified as sleep phenotypes. To address these issues, we have developed a locomotor tracking technique (the “Tracker” program) that records the exact location of a fly in real time. This allows for the detection of very small movements at any location within the tube. In addition to circadian locomotor activity, we are able to collect other information, such as distance, speed, food proximity, place preference, and multiple additional parameters that relate to sleep structure. Direct comparisons of incident recording and our motion tracking application using wild type and locomotor-deficient (CASK-β null) flies show that the increased temporal resolution in the data from the Tracker program can greatly affect the interpretation of the state of the fly. This is especially evident when a particular condition or genotype has strong effects on the behavior, and can provide a wealth of information previously unavailable to the investigator. The interaction of sleep with other behaviors can also be assessed directly in many cases with this method
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