Mitotic recombination in \u3ci\u3eSaccharomyces cerevisiae\u3c/i\u3e results from genetic instability at fragile site FS2

Common fragile sites (CFSs) are present in a number of species and are considered a normal structural feature of the eukaryotic chromosome. CFSs are regions of genetic instability prone to breaking under DNA replication stress. Cancer is a possible result of DNA breaks that lead to a loss of heterozygosity (LOR) in the cell. Mitotic homologous recombination is a method of DNA repair following a break from DNA instability. Our experiments investigated the role of mitotic recombination in the development of LOH. Replication stress was induced in Saccharomyces cerevisiae through the use of the GALl/lO promoter; this modified promoter is dependent on the galactose concentration in the media for the expression of polymerase alpha. We examined a strain with an intact fragile site (FS2 of the yeast chromosome III) as well as a control strain with FS2 interrupted by a NAT gene. We hypothesized that DNA breaks at FS2 during mitosis, under conditions of replication stress, would be repaired by homologous recombination. Higher frequencies of mitotic recombination events leading to LOH were observed for the strain with an intact FS2 region, when subjected to replication stress and compared with the control strain in conditions of unstressed growth (9.83 fold increase). Our data adds further support to LOH resulting from mitotic recombination following the formation of fragile site breaks as the experimental strain under replication stress had higher frequencies of mitotic recombination events than the control strain

RISK-RETURN ANALYSIS OF INCORPORATING ANNUAL LEGUMES AND LAMB GRAZING WITH DRYLAND CROP ROTATIONS

Profitability and risk, 1988-2001, are examined for lamb-grazed field pea as a fallow alternative with wheat, or an extended wheat-sunflower-millet rotation. Switching from conventional wheat-fallow to an extended rotation with grazed-peas increases profitability (2.3% to 7.3%), and reduces risk (below 0% target in only 2 versus 7 of 14 years).Crop Production/Industries,

Draft Genome Sequences of Four Saccharibacter sp. Strains Isolated from Native Bees.

The genus Saccharibacter is currently understudied, with only one described species, Saccharibacter floricola, isolated from a flower. In an effort to better understand the microbes that come in contact with native bee pollinators, we isolated and sequenced four additional strains of Saccharibacter from native bees in the genera Melissodes and Anthophora These genomes range in size from 2,104,494 to 2,316,791 bp (mean, 2,246,664 bp) and contain between 1,860 and 2,167 (mean, 2,060) protein-coding genes

Investigation of advanced counterrotation blade configuration concepts for high speed turboprop systems. Task 5: Unsteady counterrotation ducted propfan analysis. Computer program user's manual

The primary objective of this study was the development of a time-marching three-dimensional Euler/Navier-Stokes aerodynamic analysis to predict steady and unsteady compressible transonic flows about ducted and unducted propfan propulsion systems employing multiple blade rows. The computer codes resulting from this study are referred to as ADPAC-AOACR (Advanced Ducted Propfan Analysis Codes-Angle of Attack Coupled Row). This report is intended to serve as a computer program user's manual for the ADPAC-AOACR codes developed under Task 5 of NASA Contract NAS3-25270, Unsteady Counterrotating Ducted Propfan Analysis. The ADPAC-AOACR program is based on a flexible multiple blocked grid discretization scheme permitting coupled 2-D/3-D mesh block solutions with application to a wide variety of geometries. For convenience, several standard mesh block structures are described for turbomachinery applications. Aerodynamic calculations are based on a four-stage Runge-Kutta time-marching finite volume solution technique with added numerical dissipation. Steady flow predictions are accelerated by a multigrid procedure. Numerical calculations are compared with experimental data for several test cases to demonstrate the utility of this approach for predicting the aerodynamics of modern turbomachinery configurations employing multiple blade rows

A Qualitative Study of Workplace Stress and Coping in Secondary Teachers in Ireland

Teacher stress has received scant attention in Ireland. This study examines teachers’ perceptions of their daily stresses and how they attempt to cope with such situations. Interviews were conducted with fifteen secondary teachers from a variety of school types in eastern Ireland. The teachers showed great concern for their students, with some being prepared to ignore school guidelines in order to deal with their pupils’ needs. Several particularly stressful factors were identified, including the maintenance of boundaries (especially when dealing with students with personal problems), dealing with disruptive student behaviour, and the heavy workload. These stresses closely mirrored those described in international literature. Levels of stress and methods of dealing with stress varied widely among the sample, with primary support coming from their colleagues. One strong finding was the lack of suitable training and preparation felt by the participants, particularly in methods of dealing with sensitive and stressful situations in pupils, and in appropriate means of reaction to student misbehaviour. It is recommended that teacher-training courses include explicit training in dealing with such situations

Trials within trials? Researcher, funder and ethical perspectives on the practicality and acceptability of nesting trials of recruitment methods in existing primary care trials.

BACKGROUND: Trials frequently encounter difficulties in recruitment, but evidence on effective recruitment methods in primary care is sparse. A robust test of recruitment methods involves comparing alternative methods using a randomized trial, 'nested' in an ongoing 'host' trial. There are potential scientific, logistical and ethical obstacles to such studies. METHODS: Telephone interviews were undertaken with four groups of stakeholders (funders, principal investigators, trial managers and ethics committee chairs) to explore their views on the practicality and acceptability of undertaking nested trials of recruitment methods. These semi-structured interviews were transcribed and analysed thematically. RESULTS: Twenty people were interviewed. Respondents were familiar with recruitment difficulties in primary care and recognised the case for 'nested' studies to build an evidence base on effective recruitment strategies. However, enthusiasm for this global aim was tempered by the challenges of implementation. Challenges for host studies included increasing complexity and management burden; compatibility between the host and nested study; and the impact of the nested study on trial design and relationships with collaborators. For nested recruitment studies, there were concerns that host study investigators might have strong preferences, limiting the nested study investigators' control over their research, and also concerns about sample size which might limit statistical power. Nested studies needed to be compatible with the main trial and should be planned from the outset. Good communication and adequate resources were seen as important. CONCLUSIONS: Although research on recruitment was welcomed in principle, the issue of which study had control of key decisions emerged as critical. To address this concern, it appeared important to align the interests of both host and nested studies and to reduce the burden of hosting a recruitment trial. These findings should prove useful in devising a programme of research involving nested studies of recruitment interventions.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

A 3-year follow-up study of inpatients with lower limb ulcers: evidence of an obesity paradox?

Objectives: To determine whether body composition is related to long-term outcomes amongst vascular inpatients with lower limb ulcers. Design: Prospective study with 3 years follow-up. Materials and methods: Body mass index (BMI), fat, and fat-free mass were measured and associations with readmission to hospital (number, cause, length of stay) and all-cause mortality were explored. Results: Thirty patients (22 men, 8 women) participated in the study. Ten patients (33%) had a BMI ≥ 30 kg/m2. 18/20 (90%) patients with a BMI < 30 kg/m2 and 9/10 (90%) patients with a BMI ≥ 30 kg/m2 were admitted to hospital in the 3 years of follow-up. Patients with a BMI < 30 kg/m2 were admitted more frequently, earlier and for longer compared to those with BMI ≥ 30 kg/m2 but these did not reach statistical significance. The 3 year mortality rate for patients with BMI ≥ 30 kg/m2 was 20% (n = 2/10) compared to 70% (n = 14/20) with a BMI <30 kg/m2, P = 0.019. Conclusion: This preliminary study suggests that higher BMI may have a protective effect against mortality in vascular patients with lower limb ulcers. These findings contradict the universal acceptance that obesity leads to poor health outcomes. Further work is required to confirm these findings and explore some of the potential mechanisms for this effect

Polymicrobial oral biofilm models: simplifying the complex

Over the past century, numerous studies have used oral biofilm models to investigate growth kinetics, biofilm formation, structure and composition, antimicrobial susceptibility and host–pathogen interactions. In vivo animal models provide useful models of some oral diseases; however, these are expensive and carry vast ethical implications. Oral biofilms grown or maintained in vitro offer a useful platform for certain studies and have the advantages of being inexpensive to establish and easy to reproduce and manipulate. In addition, a wide range of variables can be monitored and adjusted to mimic the dynamic environmental changes at different sites in the oral cavity, such as pH, temperature, salivary and gingival crevicular fluid flow rates, or microbial composition. This review provides a detailed insight for early-career oral science researchers into how the biofilm models used in oral research have progressed and improved over the years, their advantages and disadvantages, and how such systems have contributed to our current understanding of oral disease pathogenesis and aetiology

Parks Canada’s adaptation framework and workshop approach: Lessons learned across a diverse series of adaptation workshops

In 2017, the Canadian Parks Council Climate Change Working Group, a team of federal, provincial, and territorial representatives, developed a Climate Change Adaptation Framework for Parks and Protected Areas, guiding practitioners through a simple, effective five-step adaptation process. This framework was adapted by Parks Canada into a two-day adaptation workshop approach, with 11 workshops subsequently held from September 2017 to May 2019 at Parks Canada sites in the Yukon, Quebec, Manitoba, Alberta, Nova Scotia, British Columbia, Newfoundland, and Ontario. Lessons learned from each workshop have been integrated into the approach, with the development of tools and guidance for each phase of the process, and a shareable, visual “placemat” that describes each step of the framework, acting as a map for those navigating the process