We examined the effect of a constitutively active Raf protein (Raf-CAAX) on the differentiation and the coincident apoptosis of skeletal myoblasts. We found that a low level of Raf signaling leads to ...accelerated differentiation when compared to parental myoblasts, while a higher level of Raf signaling induces a transformed morphology and abrogates both differentiation and the coincident apoptosis. Raf signaling abrogates apoptosis without blocking the activation of caspase 3 and the subsequent cleavage of caspase 3 substrates. Eliminating the signal from Raf through MEK does not restore the ability to differentiate or to undergo apoptosis in the myoblasts with a high level of Raf signal, nor does it abrogate the accelerated differentiation observed in myoblasts with lower levels of Raf signal. Constitutive signaling through MEK is required, however, to maintain a transformed morphology. These results indicate that the effect of Raf on the differentiation and apoptosis of skeletal myoblasts is dictated by the level of Raf signaling, and that Raf signaling sufficient to abrogate the apoptosis coincident with differentiation does so downstream of caspase 3 signaling.
Bedside safety rails are used extensively throughout hospitals and residential care environments as a safety device to protect people against the risk of falling out of bed. However, several adverse ...incidents involving body entrapment have been linked to their use, which have resulted in serious injury to the bed occupants and, in more extreme cases, fatalities. Internationally agreed standards (i.e. European Committee for Standardisation (CEN) standards) for the design and testing of bed rails have recently been developed and are targeted at improved safety requirements (European Committee for Standardisation
1997
2000
). The purpose of the present study was to: 1) determine whether the CEN test procedure for assessing bed rail strength and rigidity requirements is consistent with human force exertions to which bed rails may be exposed; 2) carry out loading tests on bed rails currently in use throughout the UK to determine whether they comply with the current safety recommendations proposed by the CEN standards.
A laboratory study was conducted to determine the force exertions of 20 participants performing seven tasks (including activities of both bed occupants and care providers), which were considered representative of the forces to which bed rails could be exposed during normal use. Forces exerted by participants were measured using a force platform and distortions of the bed rails leading to potential entrapment zones were measured using linear displacement transducers. Static load tests were then conducted, in which incremental point loading was applied at the most adverse points on each of nine different bed rails (commonly used in UK nursing and residential care homes) in accordance with the test procedure detailed in the current CEN standards.
Maximum static forces exerted by participants were found to range between 250 N and 350 N, which were within the 500 N force tolerance requirements set by the standards. Dynamic tasks involving 'rolling aggressively' against the bed rail produced the highest peak force of 722 N. None of the bed rails included in this study met the requirements of the CEN test procedures, principally due to horizontal lateral displacements being in excess of 50 mm for a 500 N applied force and/or the bed rails' inability to withstand inward horizontal forces of 500 N. Bed rails used with divan beds were often unable to withstand forces greater than 300 N due to turning moments exceeding the bed rail's restraining mechanism.
Current CEN standards for assessing the strength and rigidity of bedside safety rails appear to be consistent with the human forces that might arise as a consequence of the normal movement and activities of a bed occupant or care provider. Although compliance with existing standards is not compulsory, findings from the tests carried out on the selection of bed rails in current use throughout the UK highlight the need for improvements in the design and manufacture of bed rails.
The authors replicated
O. Ostberg's (1980)
study of forestry workers using a range of personnel groups in coal mines. Findings demonstrate a high level of consensus between a range of personnel ...groups for a set of pictorially depicted behavioral risks, at the level of rank order, but significant differences in terms of relative magnitudes. Magnitudes of perceived risk were found to be greater for those closest to the point of hazard than for members of more geographically and experientially distal groups. Findings are interpreted with reference to experiential influences associated with organizational role. Revealed differences between personnel groups are explained in terms of cognitive availability, specifically effects associated with habituation and familiarity with risk, these sources of perceptual bias appearing to interact with organizational role.
Eukaryotic microalgae hold great promise for the bioproduction of fuels and higher value chemicals. However, compared with model genetic organisms such as Escherichia coli and Saccharomyces ...cerevisiae, characterization of the complex biology and biochemistry of algae and strain improvement has been hampered by the inefficient genetic tools. To date, many algal species are transformable only via particle bombardment, and the introduced DNA is integrated randomly into the nuclear genome. Here we describe the first nuclear episomal vector for diatoms and a plasmid delivery method via conjugation from Escherichia coli to the diatoms Phaeodactylum tricornutum and Thalassiosira pseudonana. We identify a yeast-derived sequence that enables stable episome replication in these diatoms even in the absence of antibiotic selection and show that episomes are maintained as closed circles at copy number equivalent to native chromosomes. This highly efficient genetic system facilitates high-throughput functional characterization of algal genes and accelerates molecular phytoplankton research.
Summary
Diatoms are unicellular photosynthetic algae with promise for green production of fuels and other chemicals. Recent genome‐editing techniques have greatly improved the potential of many ...eukaryotic genetic systems, including diatoms, to enable knowledge‐based studies and bioengineering. Using a new technique, transcription activator‐like effector nucleases (TALENs), the gene encoding the urease enzyme in the model diatom, Phaeodactylum tricornutum, was targeted for interruption. The knockout cassette was identified within the urease gene by PCR and Southern blot analyses of genomic DNA. The lack of urease protein was confirmed by Western blot analyses in mutant cell lines that were unable to grow on urea as the sole nitrogen source. Untargeted metabolomic analysis revealed a build‐up of urea, arginine and ornithine in the urease knockout lines. All three intermediate metabolites are upstream of the urease reaction within the urea cycle, suggesting a disruption of the cycle despite urea production. Numerous high carbon metabolites were enriched in the mutant, implying a breakdown of cellular C and N repartitioning. The presented method improves the molecular toolkit for diatoms and clarifies the role of urease in the urea cycle.
Dinitrogen (N
)-fixation by cyanobacteria in symbiosis with feathermosses is the primary pathway of biological nitrogen (N) input into boreal forests. Despite its significance, little is known about ...the cyanobacterial gene repertoire and regulatory rewiring needed for the establishment and maintenance of the symbiosis. To determine gene acquisitions and regulatory changes allowing cyanobacteria to form and maintain this symbiosis, we compared genomically closely related symbiotic-competent and -incompetent Nostoc strains using a proteogenomics approach and an experimental set up allowing for controlled chemical and physical contact between partners. Thirty-two gene families were found only in the genomes of symbiotic strains, including some never before associated with cyanobacterial symbiosis. We identified conserved orthologs that were differentially expressed in symbiotic strains, including protein families involved in chemotaxis and motility, NO regulation, sulfate/phosphate transport, and glycosyl-modifying and oxidative stress-mediating exoenzymes. The physical moss-cyanobacteria epiphytic symbiosis is distinct from other cyanobacteria-plant symbioses, with Nostoc retaining motility, and lacking modulation of N
-fixation, photosynthesis, GS-GOGAT cycle and heterocyst formation. The results expand our knowledge base of plant-cyanobacterial symbioses, provide a model of information and material exchange in this ecologically significant symbiosis, and suggest new currencies, namely nitric oxide and aliphatic sulfonates, may be involved in establishing and maintaining the cyanobacteria-feathermoss symbiosis.
Centromeres are essential for cell division and growth in all eukaryotes, and knowledge of their sequence and structure guides the development of artificial chromosomes for functional cellular ...biology studies. Centromeric proteins are conserved among eukaryotes; however, centromeric DNA sequences are highly variable. We combined forward and reverse genetic approaches with chromatin immunoprecipitation to identify centromeres of the model diatom Phaeodactylum tricornutum. We observed 25 unique centromere sequences typically occurring once per chromosome, a finding that helps to resolve nuclear genome organization and indicates monocentric regional centromeres. Diatom centromere sequences contain low-GC content regions but lack repeats or other conserved sequence features. Native and foreign sequences with similar GC content to P. tricornutum centromeres can maintain episomes and recruit the diatom centromeric histone protein CENH3, suggesting nonnative sequences can also function as diatom centromeres. Thus, simple sequence requirements may enable DNA from foreign sources to persist in the nucleus as extrachromosomal episomes, revealing a potential mechanism for organellar and foreign DNA acquisition.
In nitrogen-limited boreal forests, associations between feathermoss and diazotrophic cyanobacteria control nitrogen inputs and thus carbon cycling, but little is known about the molecular regulators ...required for initiation and maintenance of these associations. Specifically, a benefit to the cyanobacteria is not known, challenging whether the association is a nutritional mutualism. Targeted mutagenesis of the cyanobacterial alkane sulfonate monooxygenase results in an inability to colonize feathermosses by the cyanobacterium Nostoc punctiforme, suggesting a role for organic sulfur in communication or nutrition. Isotope probing paired with high-resolution imaging mass spectrometry (NanoSIMS) demonstrated bidirectional elemental transfer between partners, with carbon and sulfur both being transferred to the cyanobacteria, and nitrogen transferred to the moss. These results support the hypothesis that moss and cyanobacteria enter a mutualistic exosymbiosis with substantial bidirectional material exchange of carbon and nitrogen and potential signaling through sulfur compounds.
One-way pendulum? Weyman, Andrew K.; Roy, Deborah; Nolan, Peter
International journal of workplace health management,
02/2020, Letnik:
13, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Purpose
Staff shortage in the UK National Health Service has a long history, but is widely predicted to become acute over the next decade. Falling enrolment rates in health professional training and ...restrictions to migrant labour recruitment have brought the, traditionally neglected, issue of staff retention into sharp relief. The purpose of this paper is to represent the first large scale systematic appraisal of the relative salience of recognised headline drivers of employee exodus from the NHS.
Design/methodology/approach
The data were collected from an opportunity sample of 1,594 health professionals, managers and administrators employed by the NHS. Participants completed a paired ranking task (Case V method of paired comparisons, Thurston, 1927) to determine the relative importance of eight widely cited reasons for exit. The item set was derived from focus groups conducted as a component of the wider study.
Findings
Findings revealed almost universal consensus regarding the primacy of shortage of resources, job demands and time pressure. Pay was ranked lower than predicted. Flexible working arrangements do not presented as a key solution, and there is no support for claims of generational differences.
Research limitations/implications
Survivor population effects could constitute a source of sample bias, i.e. all participants were current NHS employees. It is possible that those who remain may be more resilient or hold different dispositions to leavers. Thus, comparisons by age and grade may not be comparing like with like. Tapping respondent beliefs about the actions of peers can embody some degree of inaccuracy and attribution bias. However, effects can be considered to operate as a source of common, rather than systematic, error across the demographics compared. The medical and dental sample was too small to give confidence in detected differences.
Practical implications
Findings challenge the claim that wider availability of flexible working hours will significantly reduce exit rates. Pay, being a source of dissatisfaction, does not constitute a key push variable in itself, rather its salience reflects the effort reward-imbalance produced by rises in job demands.
Social implications
Staff shortages in the NHS represent a threat to: public well-being – waiting lists and demand for care; the well-being of who continue to work in the NHS – job demands and resources; the employment prospects of staff who leave involuntarily, e.g. on grounds of incapacity and threats to health and well-being – extending to impacts on their dependents.
Originality/value
Issues of staff retention within the NHS are topical and under researched. The findings provide an up to date picture of the relative influence of headline drivers of early exit from the NHS. The study draws upon a more diverse and comprehensive sample of NHS employees that any other known previous studies of early exit. Findings are of potential international relevance to other State health systems. The authors believe this to be the largest (sample) known application of the method of paired comparisons.
Objectives:
To explore and portray the perspectives of National Health Service Ambulance personnel related to the latest rise in the National Health Service occupational pension age.
Methods:
Data ...gathering took the form of 35 in-depth interviews. A thematic analysis was used to characterise and articulate key concepts and meanings. The analysis applied interpretive techniques, as views expressed were from personal experiences, and allowed for an in-depth analysis of shared meanings.
Results:
The themes reported captured the desire of many Ambulance personnel to exit their employment well in advance of their retirement age, despite satisfaction gained from patient care. This early exit is being driven by increased worry that the work demands of the job are unsustainable, especially for older workers, as clinical responsibilities increase and their social support diminishes. Also, Ambulance personnel feel betrayed by their employers, because their retirement is being delayed further by another change in their pensionable age.
Conclusion:
There is an increased orientation for ‘living for today’ and indications of a willingness to sacrifice salary and pension income in order to protect their health in older age, which has implications for long-term financial and general well-being in retirement.
PDF
