1,583 research outputs found
Coordinated transcriptional regulation between a reactive oxygen species-responsive gene network and the circadian clock in Arabidopsis thaliana : a thesis presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Plant Biology at Massey University, Plant Biology, New Zealand
Most organisms have evolved endogenous biological clocks as internal timekeepers to
fine-tune physiological processes to the external environment. Energetic cycles such as
photosynthesis and glycolytic cycles are physiological processes that have been shown
to be under clock control. This work sought to understand the mechanism of the
synchrony between the circadian oscillator and products of energetic cycles. The fact
that plants rely on photosynthesis for survival,and that photosynthesis relies on the
sun, this would have meant that oxygen levels would have fluctuated across the day. A
common by-product of oxygen metabolism and photosynthesis is the Reactive Oxygen
Species(ROS). Evidence has proposed ROS as regulators of cellular signaling and plant
development. However, if ROS levels are left unmanaged, it may cause oxidative stress
in organisms, which could damage cellular components and disrupt normal
mechanisms of cellular signaling. Therefore, it is advantageous for plants to be able to
anticipate such periodic burst in ROS. My research investigates the role of the
circadian clock in regulating ROS homeostasis in the model plant Arabidopsis thaliana.
I found that ROS production and scavenging wax and wane in a periodic manner under
diurnal and circadian conditions. Not only that, at the transcriptional level, ROS7
responsive genes exhibited time-of-day specific phases under diurnal and circadian
conditions,suggesting the role of the circadian clock in ROS signaling. Mutations in the
core-clock regulator, CIRCADIAN3 CLOCK3 ASSOCIATED3 1 (CCA1), affect both the
transcriptional regulation of ROS genes and ROS homeostasis. Furthermore, mis-
expressions of other clock genes such as EARLY3 FLOWERING3 33 (ELF3), LUX3
ARRHYTHMO3 (LUX) and TIMING3 OF3 CAB3 EXPRESSION3 13 (TOC1) also have profound
effects on ROS signaling and homeostasis, thus suggesting a global clock effect on ROS
networks. Taken together, CCA1 is proposed as a master regulator of ROS signaling
where the response to oxidative stress is dependent on the time of CCA1 expression.
Plants exhibit the strongest response at dawn, the time when CCA1 peaks. Moreover,
CCA1 can associate to the Evening Element or CCA17Binding Site on promoters of ROS
genes in vivo to coordinate transcription. A common feature of circadian clocks is the
presence of multiple interlocked transcriptional feedback loops. It is shown here that the oscillator incorporates ROS as a component of the loop where ROS signals could
feed back to affect circadian behavior by changing CCA1 and TOC1 transcription. The
clock regulates a plethora of output pathways; particularly the transcription of an
output gene FLAVIN3BINDING3KELCH3REPEAT3FHBOX31(FKF1) is affected by ROS signals.
Temporal coordination of ROS signaling by CCA1 and the reciprocal control of circadian
behavior by ROS revealed a mechanistic link of which plants match their physiology to
the environment to confer fitness.Page v (Acknowledgements) has been removed from the published version at the author's request
Comfort Women in Japan and Korea
One of the greatest human rights abuses against women occurred during World War II when the Japanese Imperial Army a system of military brothels staffed by young women who were coerced, tricked, or abducted to work in Comfort Stations. These young women were euphemistically called Comfort Women because they were to provide comfort – that is, sexual pleasure to the Japanese soldiers. This paper will examine the genesis of the Comfort Women system, explore why the wrong has never been addressed, assess the legal grounds for holding Japan accountable in international law, and critique the legal mechanisms that have been used to obtain redress for former Comfort Women
Characterization, selection, and verification of plastic composite-supports for L(+)-lactic acid biofilm-fermentation
Discs plastic composite-supports (PCS) containing 50% agricultural products and 50% polypropylene (w/w) were produced by twin-screw high-temperature extrusion. PCS properties and ingredients (oat hulls, soybean hulls, yeast extract, soybean flour, dried red blood cells, bovine albumen, and/or salts) for Lactobacillus casei subsp. rhamnosus (ATCC 11443) biofilm formation and L(+)-lactic production was evaluated by two replications of a 25-1 design;Soybean hulls, and salts decreased the hydrophobicity of PCS (P \u3c 0.0001) and enhanced cells attachment (P \u3c 0.03). Yeast extract enhanced the growth of free and attached cells in minimal medium (P \u3c 0.0001). Bovine albumen blended with soybean hulls, yeast extract, soybean flour, and salts had the highest lactic acid concentration in the first (7.6 g/L) and twentieth (1.4 g/L) simulated repeated-batch fermentation. Under all conditions, suspended cells and polypropylene discs control gave negligible lactic-acid production and cell density;PCS blended with bovine albumen, red blood cells, and soybean flour-leached nutrients gradually (20-30% initial leached nitrogen) and could still maintain 1 g/L lactic acid and cell density (absorbance at 620 nm:0.4-0.6) after the twentieth 20-mL simulated-repeated-batch fermentation. Polypropylene discs under all circumstances gave negligible lactic acid production and cell density. Lactic acid accumulation in PCS was shown to be mainly due to absorption and had no correlation with lactic acid production or biofilm formation;PCS rings and discs with 35% soybean hulls, 5% yeast extract, 5% soybean flour, 5% dried bovine albumen, and 50% polypropylene were selected for long-term biofilm repeated-batch fermentation at controlled pH (5) and temperature (37°C). The viable cells count on the PCS surface in 0.2, 0.4, and 0.8% yeast extract (YE) Lactic-Acid-Fermentation (LAF) medium (8% glucose) was 7.1x109, 8.5x109, and 2.4x1010 cfu/g PCS, respectively. PCS-bioreactors in 0.4 and 0.8% YE LAF medium shortened the lag time by 3-fold and 6-fold, respectively. PCS-bioreactors, at all YE concentration, increased LA productivity by 40-70%. PCS-bioreactors\u27 total fermentation time with 0.2, 0.4, and 0.8% YE LAF medium were 1.4, 2.1, and 2.6 times faster than that of the control (suspended cells bioreactor), respectively. PCS-bioreactors had its fastest productivity (4.26 g/L/h) at 10% starting glucose, whereas the control (2.78 g/L/h) was at 8%. PCS biofilm lactic-acid fermentation can drastically improve fermentation rate under reduced complex nutrient addition
Predicting the risk of cancer in adults using supervised machine learning: a scoping review
OBJECTIVES:
The purpose of this scoping review is to: (1) identify existing supervised machine learning (ML) approaches on the prediction of cancer in asymptomatic adults; (2) to compare the performance of ML models with each other and (3) to identify potential gaps in research.
DESIGN:
Scoping review using the population, concept and context approach.
SEARCH STRATEGY:
PubMed search engine was used from inception to 10 November 2020 to identify literature meeting following inclusion criteria: (1) a general adult (≥18 years) population, either sex, asymptomatic (population); (2) any study using ML techniques to derive predictive models for future cancer risk using clinical and/or demographic and/or basic laboratory data (concept) and (3) original research articles conducted in all settings in any region of the world (context).
RESULTS:
The search returned 627 unique articles, of which 580 articles were excluded because they did not meet the inclusion criteria, were duplicates or were related to benign neoplasm. Full-text reviews were conducted for 47 articles and a final set of 10 articles were included in this scoping review. These 10 very heterogeneous studies used ML to predict future cancer risk in asymptomatic individuals. All studies reported area under the receiver operating characteristics curve (AUC) values as metrics of model performance, but no study reported measures of model calibration.
CONCLUSIONS:
Research gaps that must be addressed in order to deliver validated ML-based models to assist clinical decision-making include: (1) establishing model generalisability through validation in independent cohorts, including those from low-income and middle-income countries; (2) establishing models for all cancer types; (3) thorough comparisons of ML models with best available clinical tools to ensure transparency of their potential clinical utility; (4) reporting of model calibration performance and (5) comparisons of different methods on the same cohort to reveal important information about model generalisability and performance
Prediction of fibrosis progression in chronic viral hepatitis
Prediction of liver fibrosis progression has a key role in the management of chronic viral hepatitis, as it will be translated into the future risk of cirrhosis and its various complications including hepatocellular carcinoma. Both hepatitis B and C viruses mainly lead to fibrogenesis induced by chronic inflammation and a continuous wound healing response. At the same time direct and indirect profibrogenic responses are also elicited by the viral infection. There are a handful of well-established risk factors for fibrosis progression including older age, male gender, alcohol use, high viral load and co-infection with other viruses. Metabolic syndrome is an evolving risk factor of fibrosis progression. The new notion of regression of advanced fibrosis or even cirrhosis is now strongly supported various clinical studies. Even liver biopsy retains its important role in the assessment of fibrosis progression, various non-invasive assessments have been adopted widely because of their non-invasiveness, which facilitates serial applications in large cohorts of subjects. Transient elastography is one of the most validated tools which has both diagnostic and prognostic role. As there is no single perfect test for liver fibrosis assessment, algorithms combining the most validated noninvasive methods should be considered as initial screening tools
Profiling Minority Law Librarians: A Report on the 1992-93 Survey
The authors present a demographic and professional profile of AALL minority law librarian members based upon responses to a detailed survey that elicited information about work experience and skills, professional activities and participation, and career aspirations. The results lead the authors to suggest some recruitment strategies to increase diversity in law librarianship and the level of minority participation in AALL
Profiling Minority Law Librarians: A Report on the 1992-93 Survey
The authors present a demographic and professional profile of AALL minority law librarian members based upon responses to a detailed survey that elicited information about work experience and skills, professional activities and participation, and career aspirations. The results lead the authors to suggest some recruitment strategies to increase diversity in law librarianship and the level of minority participation in AALL
Horizontal transfer of boron by the Formosan subterranean termite (Coptotermes formosanau Shiraki) after feeding on treated wood
The goal of the present study was to determine whether Coptotermes formosanus Shiraki workers exposed to boron-treated wood were capable of transferring quantifiable amounts of boron to non-exposed nestmates. This effect is called horizontal transfer. Borates are not repellent to termites, nor do they cause rapid mortality, making them excellent candidates for the study of horizontal transfer. In the present study, C. formosanus workers were collected from field colonies maintained in Honolulu, Hawaii and dyed with Sudan Red 7B over a 7-day period. These termites then underwent a 3-day exposure period to one of two types of composite board, either an experimental formulation of zinc borate and anhydrous boric acid or an untreated composite board. Treated termites were placed with an equal number of untreated termites for either 5 or 10 days; sham-dyed donors and recipients were used to control for possible effects of the dye. Horizontal transmission of boron and toxic effects were assessed based on termite wet weight, percent survival, and boron content. Horizontal transfer of boron was noted at both 5 and 10 days over those levels reported in untreated, field-caught termites from the same colony (ca. 7 μg boron g termites). After 5 days, boron content was elevated in both dyed donor and recipient termites (ca. 92 and 38 μg boron g dyed termites, respectively), as well as in undyed donors and recipients (ca. 84 and 30 μg boron g undyed termites). The same pattern was observed after 10 days in both dyed donor and recipient termites (ca. 61 and 46 μg boron g , respectively) and undyed donor and recipient termites (59 and 24 μg boron g , respectively). Increased boron content of recipient termites after exposure to donor termites (fed on treated wood) demonstrated horizontal transfer of boron
The over-35s: early intervention in psychosis services entering uncharted territory
Aims and method: Following the introduction of new standards for early intervention in psychosis (EIP) in England, EIP services are accepting referrals for people aged 35–65. The Cambridgeshire and Peterborough EIP service (CAMEO) aimed to explore the immediate implications for the service, especially with regards to referral numbers and sources. Data were collected from April 2016 to June 2017. Results: Referrals for over-35s represented 25.7% of all new referrals. Fifty per cent of referrals for over-35s were accepted onto caseload (40.2% for under-35s). The over-35s were more likely to be referred from acute and secondary mental health services (P < 0.01) and had longer durations of untreated psychosis than the under-35s (P = 0.02). Clinical implications: CAMEO has received a significantly higher number of referrals as a result of age inclusivity, with an increased proportion of patients suffering from severe, acute psychotic presentations and existing mental health difficulties. This has implications for service planning
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