Interaction of Temperature and Light in the Development of Freezing Tolerance in Plants

Abstract Freezing tolerance is the result of a wide range of physical and biochemical processes, such as the induction of antifreeze proteins, changes in membrane composition, the accumulation of osmoprotectants, and changes in the redox status, which allow plants to function at low temperatures. Even in frost-tolerant species, a certain period of growth at low but nonfreezing temperatures, known as frost or cold hardening, is required for the development of a high level of frost hardiness. It has long been known that frost hardening at low temperature under low light intensity is much less effective than under normal light conditions; it has also been shown that elevated light intensity at normal temperatures may partly replace the cold-hardening period. Earlier results indicated that cold acclimation reflects a response to a chloroplastic redox signal while the effects of excitation pressure extend beyond photosynthetic acclimation, influencing plant morphology and the expression of certain nuclear genes involved in cold acclimation. Recent results have shown that not only are parameters closely linked to the photosynthetic electron transport processes affected by light during hardening at low temperature, but light may also have an influence on the expression level of several other cold-related genes; several cold-acclimation processes can function efficiently only in the presence of light. The present review provides an overview of mechanisms that may explain how light improves the freezing tolerance of plants during the cold-hardening period

Sourcing a Stone Paver from the Colonial St. Inigoes Manor, Maryland

The objective of this study is to determine the source of a limestone paver recovered from the colonial era Old Chapel Field archaeological site (18ST329-183) in St. Inigoes, Maryland. The site is in the Coastal Plain physiographic province, where there are no viable local sources of rock. As the site was a Jesuit manor, the primary hypothesis is that the stone came from England, the emigration origin point for the Maryland colonists. The secondary objective is to determine whether the stone paver was from the Jesuit Brick Chapel at St. Mary’s City (18ST1-103), reused after the chapel was torn down by 1705. Based on paleontological, lithological, and chemical analysis of the paver, sources in the Florida Platform (U.S.), Hampshire Basin (UK), Paris Basin (France), and the Belgian Basin were ruled out. The most likely source is the Aquitaine Basin in southwest France. Comparison with limestone fragments from the chapel supports reuse of the paver from the St. Mary’s City Brick Chapel

Strategic implications of valuation methods

Author's OriginalStrategy is ultimately aimed at creating shareholder value, placing valuation in a central role linking finance and strategy. Focusing on growth options, this paper uses a unique "perfect information" model to examine, from a strategy point of view, the relationship between the market value of the firm and its intrinsic, or DCF, value. Although the research is at the level of the firm, the results have implications at the level of individual strategies and projects, since a firm can be conceptualized as a collection of projects. The findings highlight the relationship between the value of growth options and macroeconomic conditions, industry characteristics, and firm-specific factors. A revised version of this paper has since been published in the journal Advances in Strategic Management. Please use this version in your citations.Alessandri, T. M., Lander, D. M., & Bettis, R. A. (2007), Strategic Implications of Valuation: Evidence from Valuing Growth Options, in Professor Brian Silverman (ed.) Real Options Theory. Advances in Strategic Management, 24, 459-48

Real-World Treatment Patterns, Survival, and Costs for Ovarian Cancer in Canada: A Retrospective Cohort Study Using Provincial Administrative Data

Background: In 2020, approximately 3100 Canadian women were diagnosed with ovarian cancer (OC), with 1950 women dying of this disease. Prognosis for OC remains poor, with 70% to 75% of cases diagnosed at an advanced stage and an overall 5-year survival of 46%. Current standard of care in Canada involves a combination of cytoreductive surgery and platinum-based chemotherapy. Objective: There are few studies reporting current OC costs. This study sought to determine patient characteristics and costs to the health system for OC in Ontario, Canada. Methods: Women diagnosed with OC in Ontario between 2010 and 2017 were identified. The cohort was linked to provincial administrative databases to capture treatment patterns, survival, and costs. Overall total and mean cost per patient (unadjusted) were reported in 2017 Canadian dollars, using a macro-based costing methodology called GETCOST. It is programmed to determine the costs of short-term and long-term episodes of health-care resources utilized. Results: Of the 2539 OC patients included in the study, the mean age at diagnosis was 60.4±11.35 years. The majority were diagnosed with stage III disease (n=1247). The only treatment required for 74% of stage I patients and 54% of stage II patients was first-line (1L) platinum chemotherapy; in advanced stages (III/IV) 24% and 20%, respectively, did not receive further treatment after 1L therapy. The median overall survival (mOS) for the whole cohort was 5.13 years. Survival was highest in earlier stage disease (mOS not reached in stage I/II), and dropped significantly in advanced stage patients (stage III: mOS=4.09 years; stage IV: mOS=3.47 years). Overall mean costs in patients stage I were CAD $58 099 compared to CAD$124 202 in stage IV. Discussion: The majority of OC patients continue to be diagnosed with advanced disease, which is associated with poor survival and increased treatment costs. Increased awareness and screening could facilitate diagnosis of earlier stage disease and reduce high downstream costs for advanced disease. Conclusion: Advanced OC is associated with poor survival and increased costs, mainly driven by hospitalizations or cancer clinic visits. The introduction of new targeted therapies such as olaparib could impact health system costs, by offsetting higher downstream costs while also improving survival

School absence and (primary) school connectedness: evidence from the Millennium Cohort Study

School-mandated exclusion, or school absence, is on the increase in England. Earlier analyses focused on the characteristics of children, rather than the relationship with school. Using the Millennium Cohort Study, we explore the relationship between school exclusion/school absence and school satisfaction. The Millennium Cohort Study is a UK birth cohort study of around 19,000 children born at the start of the twenty-first century and includes measures relating to school satisfaction, including liking school, being interested in school and being happy. We ask: What are the exclusion risk factors? What is the predictive relationship between school satisfaction and school exclusion and school absence? And what is the predictive relationship between school exclusion and school absence and subsequent school satisfaction over time? Our analysis applied fixed effect models based on within-child comparisons across time (age 11, 14 and 17). Results confirm that Millennium Cohort Study children miss school through exclusion (9 per cent) and absence (14 per cent), are disproportionately male and have special educational needs. School satisfaction was protective; a high level of satisfaction with school at age 7 and 11 reduced the likelihood of exclusion and truancy at age 14 in secondary school. Girls who experienced primary school exclusion reported significantly lower satisfaction with secondary school. We discuss the relationship between school satisfaction and school connectedness measures, with a view to a more nuanced understanding of the interaction between school attitudes to children and children’s attitudes to school. We conclude with tentative implications for policy and future research

Do concentration or activity of selenoproteins change in acute stroke patients? A systematic review and meta-analyses

IntroductionStroke is characterized by deleterious oxidative stress. Selenoprotein enzymes are essential endogenous antioxidants and detailed insight into their role after stroke could define new therapeutic treatments. This systematic review aims to elucidate how blood selenoprotein concentration and activity change in the acute phase of stroke.MethodsWe searched PubMed, EMBASE and Medline databases for studies measuring serial blood selenoprotein concentration or activity in acute stroke patients or in stroke patients compared to non-stroke controls. Meta-analyses of studies stratified by type of stroke, blood compartment and type of selenoprotein measurement were conducted.ResultsEighteen studies and data from 941 stroke patients and 708 non-stroke controls were included in this review. Glutathione peroxidase (GPx) was the only identified selenoprotein and its activity was most frequently measured. Results from 12 studies and 693 patients, showed that, compared to non-stroke controls, in acute ischaemic stroke patients GPx activity increased in haemolysate (standardised mean difference (SMD): 0.27, 95% CI 0.07 to 0.47) but decreased in plasma (mean difference (MD): -1.08 U/L, 95% CI -1.94 to -0.22) and serum (SMD: -0.54, 95% CI -0.91 to -0.17). From four identified studies in 106 acute haemorrhagic stroke patients, GPx activity decreased in haemolysate (SMD: -0.40, 95% CI - 0.68 to -0.13) and remained unchanged in plasma (MD: -0.10 U/L, 95% CI -0.81 to 0.61) and serum (MD: -5.00 U/mL, 95% CI -36.17 to 26.17) compared to non-stroke controls. Results from studies assessing GPx activity in the haemolysate compartment were inconsistent and characterized by high heterogeneity.ConclusionsOur results suggest a reduction of blood GPx activity in acute ischaemic stroke patients, a lack of evidence regarding a role for GPx in haemorrhagic stroke patients and insufficient evidence for other selenoproteins

Improved methodology for tracing a pulse of 13C-labelled tree photosynthate carbon to ectomycorrhizal roots, other soil biota and soil processes in the field

Isotopic pulse-labelling of photosynthate allows tracing of carbon (C) from tree canopies to below-ground biota and calculations of its turnover in roots and recipient soil microorganisms. A high concentration of label is desirable but is difficult to achieve in field studies of intact ecosystem patches with trees. Moreover, root systems of trees overlap considerably in most forests, which requires a large labelled area to minimize the impact of C allocated below-ground by un-labelled trees. We describe a method which combines a high level of labelling at ambient concentrations of CO2, [CO2], with undisturbed root systems and a model to account for root C and root-derived C from un-labelled trees. We raised 5-m-tall chambers, each covering 50 m2 of ground (volume 250 m3) in a young boreal Pinus sylvestris L. forest with up to 5 m tall trees. Rather than a conventional single release of 13CO2, we used five consecutive releases, each followed by a draw-down period, thus avoiding high [CO2]. Hence, we elevated successively the 13CO2 from 1.1 to 23 atom% after the first release to 61 atom% after the fifth, while maintaining [CO2] below 500 p.p.m. during 4–4.5 h of labelling. The average abundance of 13CO2 was as high as 42 atom%. We used the central 10 m2 of the 50 m2 area for sampling of roots and other soil biota. We modelled the dilution of labelled C across the plots by un-labelled C from roots of trees outside the area. In the central 10 m2 area, ~85% of roots and root-associated biota received C from labelled trees. In summary, we elevated the labelling of roots and associated soil biota four-fold compared with previous studies and described the commonly overlooked impact of roots from un-labelled trees outside the labelled area

Managing deliberate self-harm in young people: An evaluation of a training program developed for school welfare staff using a longitudinal research design

BACKGROUND: Although deliberate self-harm is prevalent among young people, many who engage in deliberate self-harm receive sub-optimal care. Although schools are a well placed setting to support young people who engage in self-harm there are no specific training packages designed to assist school welfare staff to support these young people.The current study aimed to design, deliver and evaluate a training course specifically for school staff. METHODS: The study employed a longitudinal design. Two hundred and thirteen people participated in the training and evaluation. A questionnaire was administered at baseline, immediately after the training and at 6-month follow-up in order to determine if the training led to improvements in confidence when working with young people who self-harm, perceived skill, knowledge of, and attitudes towards people who self harm. RESULTS: Prior to the course, the majority of participants demonstrated relatively high levels of confidence, perceived skill and knowledge of self-harm and endorsed relatively positive attitudes towards people who engage in self-harm. Despite this, significant improvements were observed in terms of increased confidence, increased perceptions of skill along with increased knowledge of deliberate self-harm. These improvements were sustained over the follow-up period. CONCLUSION: The results demonstrated that the provision of specifically designed training can help school welfare staff to feel better equipped to support young people who are engaging in deliberate self-harm

The Real maccoyii: Identifying Tuna Sushi with DNA Barcodes – Contrasting Characteristic Attributes and Genetic Distances

BACKGROUND:The use of DNA barcodes for the identification of described species is one of the least controversial and most promising applications of barcoding. There is no consensus, however, as to what constitutes an appropriate identification standard and most barcoding efforts simply attempt to pair a query sequence with reference sequences and deem identification successful if it falls within the bounds of some pre-established cutoffs using genetic distance. Since the Renaissance, however, most biological classification schemes have relied on the use of diagnostic characters to identify and place species. METHODOLOGY/PRINCIPAL FINDINGS:Here we developed a cytochrome c oxidase subunit I character-based key for the identification of all tuna species of the genus Thunnus, and compared its performance with distance-based measures for identification of 68 samples of tuna sushi purchased from 31 restaurants in Manhattan (New York City) and Denver, Colorado. Both the character-based key and GenBank BLAST successfully identified 100% of the tuna samples, while the Barcode of Life Database (BOLD) as well as genetic distance thresholds, and neighbor-joining phylogenetic tree building performed poorly in terms of species identification. A piece of tuna sushi has the potential to be an endangered species, a fraud, or a health hazard. All three of these cases were uncovered in this study. Nineteen restaurant establishments were unable to clarify or misrepresented what species they sold. Five out of nine samples sold as a variant of "white tuna" were not albacore (T. alalunga), but escolar (Lepidocybium flavorunneum), a gempylid species banned for sale in Italy and Japan due to health concerns. Nineteen samples were northern bluefin tuna (T. thynnus) or the critically endangered southern bluefin tuna (T. maccoyii), though nine restaurants that sold these species did not state these species on their menus. CONCLUSIONS/SIGNIFICANCE:The Convention on International Trade Endangered Species (CITES) requires that listed species must be identifiable in trade. This research fulfills this requirement for tuna, and supports the nomination of northern bluefin tuna for CITES listing in 2010

Mapping of Genes Involved in Glutathione, Carbohydrate and COR14b Cold Induced Protein Accumulation during Cold Hardening in Wheat

Using some of the chromosome substitution lines developed from the crosses of the donor Cheyenne to Chinese Spring we showed that the accumulation of water soluble carbohydrates during different stages of hardening was time dependent. Moreover there was a significant correlation between the rate of carbohydrate accumulation and the frost tolerance. The expression and regulation of a wheat gene homologous to the barley cold regulated cor14b gene was compared in frost sensitive and frost tolerant wheat genotypes at different temperatures. Studies made with chromosome substitution lines showed that the threshold induction temperature polymorphism of the cor14b wheat homologous gene was controlled by loci located on chromosome 5A of wheat, while cor14b gene was mapped, in Triticum monococcum, onto the long arm of chromosome 2Am. Our study on the effect of cold hardening on glutathione (GSH) metabolism showed that chromosome 5A of wheat has an influence on the GSH accumulation and on the ratio of reduced and oxidised glutathione as part of a complex regulatory function during cold hardening. In addition, the level of increase in GSH content during hardening may indicate the degree of the frost tolerance of wheat