1,204 research outputs found
The effect of cytokinin on the chromatin landscape of arabidopsis
Cytokinin, a N⁶ substituted adenine, is a phytohormone with pleiotropic effects, including shoot activation, root inhibition, delay of leaf senescence, and tissue regeneration. Cytokinin is perceived by a histidine kinase and ultimately results in the activation of a response regulator that controls transcription of cytokinin-dependent genes. How a single signaling molecule is involved in numerous distinct developmental processes and how it integrates with other signaling pathways remain fundamental questions in plant biology. Formaldehyde-assisted isolation of regulatory elements (FAIRE) is a technique used to isolate nucleosome-depleted regions of the genome. Nucleosome depletion is characteristic of open chromatin and such sites often contain regulatory elements that control the expression of nearby genes. In this thesis, I demonstrate that FAIRE can be used to isolate cytokinin-induced open chromatin in Arabidopsis seedlings. After sequencing and peak calling, the called peaks identified in the cytokinin treated samples were found to be enriched for the motif TAGATT, which contains the known type-B RR binding motif AGAT. These peaks were additionally enriched for binding motifs of other transcription factors, suggesting that the cytokinin response can be moderated by other signals and likely act differently in different cellular contexts. Thus, the work described in this thesis has helped refine the transcriptional model of the cytokinin response in plants and provides the foundation and tools to investigate and dissect the dynamics of the cytokinin response and how it integrates with other signaling pathways.Master of Scienc
Modelling magnetohydrodynamics to investigate variation of shielding gases on arc characteristics in the GTAW process
Gas tungsten arc welding requires a gas shield to be present in order to protect the arc area from contamination by atmospheric gases. As a result of each gas having its own unique thermophysical properties, the shielding gas selected can have a major influence on the arc stability, welding speed, weld appearance and geometry, mechanical properties and fume generation. Alternating shielding gases is a relatively new method of discreetly supplying two different shielding gases to the welding region in order to take advantage of the beneficial properties of each gas, as well as the inherent pulsing effects generated. As part of an ongoing process to fully evaluate the effects of this novel supply method, a computational fluid dynamics model has been generated to include the gas dependent thermodynamic and transport properties in order to evaluate the effects that an alternating gas supply has on the arc plasma. Experimental trials have also been conducted to validate the model arc profile predictions
Making sense of recovery after traumatic brain injury through a peer mentoring intervention:a qualitative exploration
Objective To explore the acceptability of peer mentoring for people with a traumatic brain injury (TBI) in New Zealand. Design This is a qualitative descriptive study exploring the experiences reported by mentees and mentors taking part in a feasibility study of peer mentoring. Interviews with five mentees and six mentors were carried out. Data were analysed using conventional content analysis. Setting The first mentoring session took place predischarge from the rehabilitation unit. The remaining five sessions took place in mentees' homes or community as preferred. Participants Twelve people with TBI took part: Six mentees (with moderate to severe TBI; aged 18-46) paired with six mentors (moderate to severe TBI >12 months previously; aged 21-59). Pairing occurred before mentee discharge from postacute inpatient brain injury rehabilitation. Mentors had been discharged from rehabilitation following a TBI between 1 and 5 years previously. Intervention The peer mentoring programme consisted of up to six face-to-face sessions between a mentee and a mentor over a 6-month period. The sessions focused on building rapport, exploring hopes for and supporting participation after discharge through further meetings and supported community activities. Results Data were synthesised into one overarching theme: Making sense of recovery. This occurred through the sharing of experiences and stories; was pivotal to the mentoring relationship; and appeared to benefit both mentees and mentors. Mentors were perceived as valued experts because of their personal experience of injury and recovery, and could provide support in ways that were different from that provided by clinicians or family members. Mentors required support to manage the uncertainties inherent in the role. Conclusions The insight mentors developed through their own lived experience established them as a trusted and credible source of hope and support for people re-engaging in the community post-TBI. These findings indicate the potential for mentoring to result in positive outcomes
Dietary modification for women after breast cancer treatment: a narrative review
Diet is thought to account for about 25% of cancers in developed countries. It is well documented that the risks associated with both the breast cancer itself and its treatments are important for women previously treated for breast cancer. Women are at risk of recurrence of the primary disease and prone to develop treatment-induced co-morbidities, some of which are thought to be modified by diet. With a view to making dietary recommendations for the breast cancer patients we encounter in our clinical nursing research, we mined the literature to scope the most current robust evidence concerning the role of the diet in protecting women against the recurrence of breast cancer and its potential to ameliorate some of the longer-term morbidities associated with the disease. We found that the evidence about the role of the diet in breast cancer recurrence is largely inconclusive. However, drawing on international guidelines enabled us to make three definitive recommendations. Women at risk of breast cancer recurrence, or who experience co-morbidities as a result of treatment, should limit their exposure to alcohol, moderate their nutritional intake so it does not contribute to postmenopausal weight gain, and should adhere to a balanced diet. Nursing education planned for breast cancer patients about dietary issues should ideally be individually tailored, based on a good understanding of the international recommendations and the evidence underpinning the
Baseline characteristics of people experiencing homelessness with a recent drug overdose in the PHOENIx pilot randomised controlled trial
Background: Drug-related deaths in Scotland are the highest in Europe. Half of all deaths in people experiencing homelessness are drug related, yet we know little about the unmet health needs of people experiencing homelessness with recent non-fatal overdose, limiting a tailored practice and policy response to a public health crisis.
Methods: People experiencing homelessness with at least one non-fatal street drug overdose in the previous 6 months were recruited from 20 venues in Glasgow, Scotland, and randomised into PHOENIx plus usual care, or usual care. PHOENIx is a collaborative assertive outreach intervention by independent prescriber NHS Pharmacists and third sector homelessness workers, offering repeated integrated, holistic physical, mental and addictions health and social care support including prescribing. We describe comprehensive baseline characteristics of randomised participants.
Results: One hundred and twenty-eight participants had a mean age of 42 years (SD 8.4); 71% male, homelessness for a median of 24 years (IQR 12–30). One hundred and eighteen (92%) lived in large, congregate city centre temporary accommodation. A quarter (25%) were not registered with a General Practitioner. Participants had overdosed a mean of 3.2 (SD 3.2) times in the preceding 6 months, using a median of 3 (IQR 2–4) non-prescription drugs concurrently: 112 (87.5%) street valium (benzodiazepine-type new psychoactive substances); 77 (60%) heroin; and 76 (59%) cocaine. Half (50%) were injecting, 50% into their groins. 90% were receiving care from Alcohol and Drug Recovery Services (ADRS), and in addition to using street drugs, 90% received opioid substitution therapy (OST), 10% diazepam for street valium use and one participant received heroin-assisted treatment. Participants had a mean of 2.2 (SD 1.3) mental health problems and 5.4 (SD 2.5) physical health problems; 50% received treatment for physical or mental health problems. Ninety-one per cent had at least one mental health problem; 66% had no specialist mental health support. Participants were frail (70%) or pre-frail (28%), with maximal levels of psychological distress, 44% received one or no daily meal, and 58% had previously attempted suicide.
Conclusions: People at high risk of drug-related death continue to overdose repeatedly despite receiving OST. High levels of frailty, multimorbidity, unsuitable accommodation and unmet mental and physical health care needs require a reorientation of services informed by evidence of effectiveness and cost-effectiveness.
Trial registration UK Clinical Trials Registry identifier: ISRCTN 10585019
A model of social influence on body mass index
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109867/1/nyas12344.pd
Measurement of the cross-section and charge asymmetry of bosons produced in proton-proton collisions at TeV with the ATLAS detector
This paper presents measurements of the and cross-sections and the associated charge asymmetry as a
function of the absolute pseudorapidity of the decay muon. The data were
collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with
the ATLAS experiment at the LHC and correspond to a total integrated luminosity
of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements
varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the
1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured
with an uncertainty between 0.002 and 0.003. The results are compared with
predictions based on next-to-next-to-leading-order calculations with various
parton distribution functions and have the sensitivity to discriminate between
them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables,
submitted to EPJC. All figures including auxiliary figures are available at
https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13
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