The effect of surface water removal on selected quality factors of minimally processed lettuce

Spin drying (1, 15, and 30 min) and tunnel drying (5, 10, and 15 min) were used to study the effects of surface moisture removal on the quality of minimally processed and modified atmosphere packaged lettuce over a 16-day storage period. A control sample was used to test the effects of no surface moisture removal on the quality of lettuce over the 16-day storage period. Lettuce was inoculated with indigenous lettuce spoilage flora at a level of 5x105 cfu/g. The parameters used to test the quality of the stored lettuce were percent moisture, color, package atmosphere, and microbial counts. Moisture analysis results indicated that spin drying for 1, 15, or 30 min or tunnel drying for 10 and 15 min, were less dry than the lettuce with no surface moisture removal (P\u3c0.5). Tunnel drying for 15 minutes and spin drying for 30 minutes were the most effective surface moisture removal treatments, removing 0.9 and 0.8% moisture from the lettuce surface respectively. A correlation of r = 0.996 was found between the aerobic plate counts (30°C) and the psychrotrophic counts (7°C) in the microbial study (P\u3c0.05). Spin drying produced lower microbial counts compared to the control (P\u3c0.5). Tunnel drying had no significant effect on the microbial counts (P\u3e0.05). The most effective treatments were spin drying for 15 or 30 min, removing approximately 0.5 log10 cfu/g from the lettuce (P\u3c0.05). Lettuce that was tunnel dried for 10 or 15 min or spin dried for 30 min had a higher hue angle, indicating less browning, than the control (P\u3c0.1). The total change in Color (ΔE) results were similar. The analysis of the percent carbon dioxide in the package atmosphere revealed that spin drying the lettuce significantly reduced the amount of carbon dioxide inside the package (P\u3c0.05). However, tunnel drying the lettuce had no effect on the amount of carbon dioxide inside the package (P\u3e0.05). Results from a consumer sensory panel indicated that after 4 days of storage, only 15% of the panelists would purchase the control lettuce while 40% would purchase the lettuce spin dried for 15 or 30 min or tunnel dried for 15 min. The results of this study illustrated that technique of moisture removal does make a difference in the number of microorganisms and the amount of carbon dioxide produced inside the package with only spin drying being effective. However, tunnel drying (10 and 15 min) was equally as effective as spin drying (30 min) for controlling change in color of the lettuce over storage time

How consistent are the transcriptome changes associated with cold acclimation in two species of the Drosophila virilis group?

This work was financially support by a Marie Curie Initial Training Network grant, “Understanding the evolutionary origin of biological diversity” (ITN-2008–213780 SPECIATION), grants from the Academy of Finland to A.H. (project 132619) and M.K. (projects 268214 and 272927), a grant from NERC, UK to M.G.R. (grant NE/J020818/1), and NERC, UK PhD studentship to D.J.P. (NE/I528634/1).For many organisms the ability to cold acclimate with the onset of seasonal cold has major implications for their fitness. In insects, where this ability is widespread, the physiological changes associated with increased cold tolerance have been well studied. Despite this, little work has been done to trace changes in gene expression during cold acclimation that lead to an increase in cold tolerance. We used an RNA-Seq approach to investigate this in two species of the Drosophila virilis group. We found that the majority of genes that are differentially expressed during cold acclimation differ between the two species. Despite this, the biological processes associated with the differentially expressed genes were broadly similar in the two species. These included: metabolism, cell membrane composition, and circadian rhythms, which are largely consistent with previous work on cold acclimation/cold tolerance. In addition, we also found evidence of the involvement of the rhodopsin pathway in cold acclimation, a pathway that has been recently linked to thermotaxis. Interestingly, we found no evidence of differential expression of stress genes implying that long-term cold acclimation and short-term stress response may have a different physiological basis.PostprintPeer reviewe

Downtown living: for families? : the Vancouver, BC urban livability experience and lessons for other cities

Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 2008.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Page 159 blank.Includes bibliographical references (p. 149-158).Across North America, downtowns are experiencing revitalization and population growth, as "urban pioneers" are making their homes in city centers. While downtowns are typically thought of as places for empty nesters and young, single professionals, some North American cities are experiencing recent growth in families moving downtown, despite its tradeoffs, and others are working to attract families with children to their downtowns. With an increasing number of families living in central city neighborhoods, cities are presented with unique opportunities and challenges. Initiatives to make cities more family-friendly for residents of all backgrounds and income levels will help attract and retain families downtown, as well as contribute to healthy, thriving cities overall. Using Vancouver, BC as a case study, this thesis explores urban livability in general and with specific reference to Vancouver's family-oriented downtown as one component of livability. Vancouver is consistently ranked as one of the world's most livable cities and has been a pioneer city in embracing family-friendly urban living, beginning its efforts several decades ago, while many other cities have only recently begun to address issues of livability. This thesis investigates how Vancouver has accommodated families living downtown and what elements have contributed to its world-renowned status as a model city. However, the story of this perceived "urban utopia" is not complete without consideration of the dilemmas that have come hand-in-hand with Vancouver's success, such as increasing housing prices that are unaffordable to many. These challenges reveal potential implications for other cities hoping to emulate the "Vancouver Model."(cont.) Lessons learned consider under what circumstances the elements attributable to Vancouver's "success" are applicable and realizable in other cities in North America, with a focus on Seattle, WA and Portland, OR. Recommendations are offered for both how Vancouver can improve and other cities can create more family-friendly urban environments, while avoiding the pitfalls that have come with Vancouver's success. As the case of Vancouver has demonstrated, downtown living is a complex issue and perceived successes can create powerful externalities that may diminish the city's achievements in the long-term if challenges are not properly addressed.by Sabra Elysia Loewus.M.C.P

Psychoanalysis and Constructionalism: Clinical and Metapsychological Implications

Attempts to reconceptualize the epistemological basis of psychoanalytic metapsychology and clinical praxis from constructionalist perspectives are reviewed and critiqued. The constructionalist epistemology of the American philosopher, Nelson Goodman, is absent in these discussions. Goodman offers a relativism with restraints, a constructionalist epistemology that asserts no one given reality to which our constructions must answer, but does not accept that therefore all constructions are equally valid. Instead, constructions, or what Goodman calls world versions must answer to standards of Rightness . Goodman\u27s reconception of philosophy subsumes the concept of truth as a special class of rightness, and replaces the concept of knowledge with that of understanding, the concept of certainty with that of adoption. Goodman\u27s epistemology is based on a detailed theory of symbolic reference. This dissertation applies his constructionalist thesis and the symbol theory to psychoanalytic metapsychology and clinical praxis. Psychoanalytic praxis is seen as inhering in the humanities rather than the sciences, more an art form than a scientific practice. The works of Donald Spence, Roy Schafer, Donnel Stern, and Irwin Hoffman are examined in light of Goodman\u27s thinking. Finally, the dissertation offers its own view of the analytic clinical situation based on Goodman\u27s epistemology and using the metaphor of improvisational musical performance

State Route 542: Warnick Bluff Stabilization : WSDOT-Identified Chronic Environmental Deficiencies Mitigation to Protect Infrastructure and Reduce Potential Environmental Damage

The beginning sections of this EIA give an overview of the project location. SR 542, Mt. Baker Highway runs parallel to the NF Nooksack River near the top of Warnick Bluff. Chronic repetitive erosion has been a problem that is exacerbated by severe flood events throughout the past decade. The Washington State Department of Transportation (WSDOT) estimates that the bank has eroded at a rate of approximately five feet per year since 1994. At the site of the proposed project, the SR 542 currently lies fifteen feet away from the edge of the bluff. The highway could potentially be washed into the river within three years. This site has been designated under the WSDOT Chronic Environmental Deficiencies Mitigation program to protect infrastructure and reduce potential environmental damage

Metabolic effects of elevated temperature on organic acid degradation in ripening <em>Vitis vinifera</em> fruit

First published online: September 1, 2014Berries of the cultivated grapevine Vitis vinifera are notably responsive to temperature, which can influence fruit quality and hence the future compatibility of varieties with their current growing regions. Organic acids represent a key component of fruit organoleptic quality and their content is significantly influenced by temperature. The objectives of this study were to (i) manipulate thermal regimes to realistically capture warming-driven reduction of malate content in Shiraz berries, and (ii) investigate the mechanisms behind temperature-sensitive malate loss and the potential downstream effects on berry metabolism. In the field we compared untreated controls at ambient temperature with longer and milder warming (2-4 °C differential for three weeks; Experiment 1) or shorter and more severe warming (4-6 °C differential for 11 days; Experiment 2). We complemented field trials with control (25/15 °C) and elevated (35/20 °C) day/night temperature controlled-environment trials using potted vines (Experiment 3). Elevating maximum temperatures (4-10 °C above controls) during pre-véraison stages led to higher malate content, particularly with warmer nights. Heating at véraison and ripening stages reduced malate content, consistent with effects typically seen in warm vintages. However, when minimum temperatures were also raised by 4-6 °C, malate content was not reduced, suggesting that the regulation of malate metabolism differs during the day and night. Increased NAD-dependent malic enzyme activity and decreased phosphoenolpyruvate carboxylase and pyruvate kinase activities, as well as the accumulation of various amino acids and γ-aminobutyric acid, suggest enhanced anaplerotic capacity of the TCA cycle and a need for coping with decreased cytosolic pH in heated fruit.C. Sweetman, V. O. Sadras, R. D. Hancock, K. L. Soole and C. M. For

Short-Lived Trace Gases in the Surface Ocean and the Atmosphere

The two-way exchange of trace gases between the ocean and the atmosphere is important for both the chemistry and physics of the atmosphere and the biogeochemistry of the oceans, including the global cycling of elements. Here we review these exchanges and their importance for a range of gases whose lifetimes are generally short compared to the main greenhouse gases and which are, in most cases, more reactive than them. Gases considered include sulphur and related compounds, organohalogens, non-methane hydrocarbons, ozone, ammonia and related compounds, hydrogen and carbon monoxide. Finally, we stress the interactivity of the system, the importance of process understanding for modeling, the need for more extensive field measurements and their better seasonal coverage, the importance of inter-calibration exercises and finally the need to show the importance of air-sea exchanges for global cycling and how the field fits into the broader context of Earth System Science