Characterisation of a pucBA deletion mutant from Rhodopseudomonas palustris lacking all but the pucBAd genes

Rhodopseudomonas palustris is a species of purple photosynthetic bacteria that has a multigene family of puc genes that encode the alpha and beta apoproteins, which form the LH2 complexes. A genetic dissection strategy has been adopted in order to try and understand which spectroscopic form of LH2 these different genes produce. This paper presents a characterisation of one of the deletion mutants generated in this program, the pucBAd only mutant. This mutant produces an unusual spectroscopic form of LH2 that only has a single large NIR absorption band at 800 nm. Spectroscopic and pigment analyses on this complex suggest that it has basically a similar overall structure as that of the wild-type HL LH2 complex. The mutant has the unique phenotype where the mutant LH2 complex is only produced when cells are grown at LL. At HL the mutant only produces the LH1-RC core complex

Expressions 2000

https://openspace.dmacc.edu/expressions/1019/thumbnail.jp

Assessment of RNAlater® as a Potential Method to Preserve Bovine Muscle Proteins Compared with Dry Ice in a Proteomic Study

peer-reviewedRNAlater® is regarded as a potential preservation method for proteins, while its effect on bovine muscle proteins has rarely been evaluated. Bovine muscle protein samples (n = 12) collected from three tender (Warner–Bratzler shear force: 30.02–31.74 N) and three tough (Warner–Bratzler shear force: 54.12–66.25 N) Longissimus thoracis et lumborum (LTL) samples, preserved using two different sampling preservation methods (RNAlater® and dry ice), at two post mortem time points (day 0 and day 14), were characterized using one-dimensional electrophoresis. Fourteen bands with molecular weights ranging from 15 to 250 kDa were verified, both in the dry ice and RNAlater® storage groups, at each time point, using image analysis. A shift from high to low molecular weight fragments, between day 0 and day 14, indicated proteolysis of the muscle proteins during post mortem storage. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analyses and database searching resulted in the identification of 10 proteins in four bands. Protein profiles of muscle preserved in RNAlater® were similar to those of muscle frozen on dry ice storage, both at day 0 and day 14. The results demonstrate that RNAlater® could be a simple and efficient way to preserve bovine muscle proteins for bovine muscle proteomic studie

Color responses of the human lateral geniculate nucleus: selective amplification of S-cone signals between the lateral geniculate nucleno and primary visual cortex measured with high-field fMRI

The lateral geniculate nucleus (LGN) is the primary thalamic nucleus that relays visual information from the retina to the primary visual cortex (V1) and has been extensively studied in non-human primates. A key feature of the LGN is the segregation of retinal inputs into different cellular layers characterized by their differential responses to red-green (RG) color (L/M opponent), blue-yellow (BY) color (S-cone opponent) and achromatic (Ach) contrast. In this study we use high-field functional magnetic resonance imaging (4 tesla, 3.6 × 3.6 × 3 mm3) to record simultaneously the responses of the human LGN and V1 to chromatic and Ach contrast to investigate the LGN responses to color, and how these are modified as information transfers between LGN and cortex. We find that the LGN has a robust response to RG color contrast, equal to or greater than the Ach response, but a significantly poorer sensitivity to BY contrast. In V1 at low temporal rates (2 Hz), however, the sensitivity of the BY color pathway is selectively enhanced, rising in relation to the RG and Ach responses. We find that this effect generalizes across different stimulus contrasts and spatial stimuli (1-d and 2-d patterns), but is selective for temporal frequency, as it is not found for stimuli at 8 Hz. While the mechanism of this cortical enhancement of BY color vision and its dynamic component is unknown, its role may be to compensate for a weak BY signal originating from the sparse distribution of neurons in the retina and LGN

Badger territoriality maintained despite disturbance of major road construction

Publication history: Accepted - 19 August 2021; Published - 3 September 2021.Road ecology has traditionally focused on the impact of in-situ and functional roads on wildlife. However, road construction also poses a major, yet understudied, threat and the implications for key aspects of animal behaviour are unknown. Badgers (Meles meles) have been implicated in the transmission of tuberculosis to cattle. There are concerns that environmental disturbances, including major road construction, can disrupt badger territoriality, promoting the spread of the disease to cattle. To address these knowledge gaps the ranging behaviour of a medium-density Irish badger population was monitored using GPS-tracking collars before, during, and after a major road realignment project that bisected the study area. We estimated badgers’ home range sizes, nightly distances travelled, and the distance and frequency of extra-territorial excursions during each phase of the study and quantified any changes to these parameters. We show that road construction had a very limited effect on ranging behaviour. A small increase in nightly distance during road construction did not translate into an increase in home range size, nor an increase in the distance or frequency of extra-territorial excursions during road construction. In addition, suitable mitigation measures to prevent badger deaths appeared to ensure that normal patterns of ranging behaviour continued once the new road was in place. We recommend that continuous badger- proof fencing be placed along the entire length of new major roads, in combination with appropriately sited underpasses. Our analysis supports the view that road construction did not cause badgers to change their ranging behaviour in ways likely to increase the spread of tuberculosis.AG was supported by a PhD scholarship provided by the Department of Agriculture, Food and the Marine, Ireland. This project was conceived, carried out and funded by the Department of Agriculture, Food and the Marine, Ireland, and the National Parks and Wildlife Service, Ireland

Paper 2: Conceptualizing the transition from advanced to consultant practitioner: role clarity, self-perception, and adjustment

Background Interest in the influence of emotions on behaviour, decision making, and leadership has accelerated over the last decade. Despite this, the influence of emotions on career advancement and behaviour within radiography and radiotherapy has largely been ignored. The ease of transition from one work role to another within an individual's career may be influenced by previous experience, personal characteristics, organizational environment, culture, and the nature of the role itself. Consequently, the transition from the often well-defined role of advanced or specialist practitioner to the more fluid role of consultant practitioner is associated with changing emotions as reported in the first part of this two-part series. What remains unexplored are the emotional triggers that pre-empt each stage in the transition cycle and how our understanding of these might support the successful implementation of consultant practitioner roles. Objectives To explore the emotional triggers that pre-empted each stage in the transitional journey of trainee consultant radiographers as they moved from advanced to consultant practitioner within a locally devised consultant development program. Design Longitudinal qualitative enquiry. Methods and Settings Five trainee consultant radiographers were recruited to a locally devised consultant practice development program within a single UK hospital trust. Semistructured interviews were undertaken at 1, 6, and 12 months with the trainees. Results Although all trainee consultant radiographers experienced the emotional events described in the first part of this two-part series in a predictable order (ie, elation, denial, doubt, crisis, and recovery), the timing of the events was not consistent. Importantly, four emotional triggers were identified, and the dominance of these and the reaction of individuals to them determined the emotional well-being of the individual over time. Conclusions This study provides a unique and hitherto unexplored insight into the transition journey from advanced or specialist practitioner. Importantly, the findings suggest that commonly adopted supportive change interventions may, in fact, trigger the negative emotions they are intended to alleviate and disable rather than enable role transition

Enrichment of CpG island shore region hypermethylation in epigenetic breast field cancerization

While changes in DNA methylation are known to occur early in breast carcinogenesis and the landscape of breast tumour DNA methylation is profoundly altered compared with normal tissue, there have been limited efforts to identify DNA methylation field cancerization effects in histologically normal breast tissue adjacent to tumour. Matched tumour, histologically normal tissue of the ipsilateral breast (ipsilateral-normal), and histologically normal tissue of the contralateral breast (contralateral-normal) were obtained from nine women undergoing bilateral mastectomy. Laser capture microdissection was used to select epithelial cells from normal tissue, and neoplastic cells from tumour for genome-scale measures of DNA methylation with the Illumina HumanMethylationEPIC array. We identified substantially more CpG loci that were differentially methylated between contralateral-normal and tumour (63,271 CpG loci q \u3c 0.01), than between ipsilateral-normal and tumour (38,346 CpG loci q \u3c 0.01). We identified differential methylation in ipsilateral-normal relative to contralateral-normal tissue (9,562 CpG loci p \u3c 0.01). In this comparison, hypomethylated loci were significantly enriched for breast cancer-relevant transcription factor binding sites including those for ESR1, FoxA1, and GATA3 and hypermethylated loci were significantly enriched for CpG island shore regions. In addition, progression of shore hypermethylation was observed in tumours compared to matched ipsilateral normal tissue, and these alterations tracked to several well-established tumour suppressor genes. Our results indicate an epigenetic field effect in surrounding histologically normal tissue. This work offers an opportunity to focus investigations of early DNA methylation alterations in breast carcinogenesis and potentially develop epigenetic biomarkers of disease risk

Mapping replication dynamics in Trypanosoma brucei reveals a link with telomere transcription and antigenic variation

Survival of Trypanosoma brucei depends upon switches in its protective Variant Surface Glycoprotein (VSG) coat by antigenic variation. VSG switching occurs by frequent homologous recombination, which is thought to require locus-specific initiation. Here, we show that a RecQ helicase, RECQ2, acts to repair DNA breaks, including in the telomeric site of VSG expression. Despite this, RECQ2 loss does not impair antigenic variation, but causes increased VSG switching by recombination, arguing against models for VSG switch initiation through direct generation of a DNA double strand break (DSB). Indeed, we show DSBs inefficiently direct recombination in the VSG expression site. By mapping genome replication dynamics, we reveal that the transcribed VSG expression site is the only telomeric site that is early replicating – a differential timing only seen in mammal-infective parasites. Specific association between VSG transcription and replication timing reveals a model for antigenic variation based on replication-derived DNA fragility

Paper 1: Conceptualizing the transition from advanced to consultant practitioner: career promotion or significant life event?

Background The diversification of nursing and allied health profession (AHP) roles has seen unprecedented growth as organizations have sought to optimize limited health care resources. Within the UK health care system, the nonmedical consultant is viewed as the pinnacle of the clinical career ladder. Yet, nearly 15 years after their introduction, recruitment to these positions remains slow. Criticisms of nonmedical consultant practice include a lack of role clarity, a failure to work across the four domains of consultant practice, a lack of suitable applicants, and poor preparedness of new appointments. Although there is evidence exploring the nature and effectiveness of established consultant roles, little research addresses the development phase of aspiring consultants. Objectives To explore the transitional journey experienced by trainee consultant radiographers as they move from advanced to consultant practitioner within a locally devised consultant development programme. Design Longitudinal qualitative enquiry. Methods and Settings Five trainee consultant radiographers were recruited to a locally devised consultant practice development program within a single UK hospital trust. Semistructured interviews were undertaken at 1, 6, and 12 months with the trainees. Results A challenging journey was recounted involving five key emotional stages that occurred in a consistent and predictable order (ie, elation, denial, doubt, crisis, and recovery). The identified stages had close parallels with Hopson's Life Events model, suggesting that transition to consultant practice is a significant life event rather than a straightforward job promotion. Conclusions Current emphasis on the four domains of practice, although providing a clear framework for expected external role outcomes, overlooks the importance of the internal or subjective career development on the perceived success or failure of the role. Employers, educators, and professional bodies have a responsibility to facilitate aspirational consultants to explore and enhance their internal career development, offering more time to define themselves and their role with support to guide them through the transition journey