784 research outputs found
Mind over memory: cueing the aging brain
A decline in recollection is a hallmark of even healthy aging and is associated with wider impairments in mental control. Older adults have difficulty internally directing thought and action in line with their goals, and often rely more on external cues. To assess the impact this has on memory, emerging brain-imaging and behavioral approaches investigate the operation and effectiveness of goal-directed control before information is retrieved. Current data point to effects of aging at more than one stage in this process, particularly in the face of competing goals. These effects may reflect wider changes in the proactive, self-initiated regulation of thought and action. Understanding them is essential for establishing whether internal âself-cuingâ of memory can be improved, and whetherâand whenâit is best to use environmental support from external cues to maximize memory performance
Deletion of the Polycomb-Group Protein EZH2 Leads to Compromised Self-Renewal and Differentiation Defects in Human Embryonic Stem Cells
Through the histone methyltransferase EZH2, the Polycomb complex PRC2 mediates H3K27me3 and is associated with transcriptional repression. PRC2 regulates cell-fate decisions in model organisms; however, its role in regulating cell differentiation during human embryogenesis is unknown. Here, we report the characterization of -deficient human embryonic stem cells (hESCs). H3K27me3 was lost upon deletion, identifying an essential requirement for EZH2 in methylating H3K27 in hESCs, in contrast to its non-essential role in mouse ESCs. Developmental regulators were derepressed in -deficient hESCs, and single-cell analysis revealed an unexpected acquisition of lineage-restricted transcriptional programs. -deficient hESCs show strongly reduced self-renewal and proliferation, thereby identifying a more severe phenotype compared to mouse ESCs. -deficient hESCs can initiate differentiation toward developmental lineages; however, they cannot fully differentiate into mature specialized tissues. Thus, is required for stable ESC self-renewal, regulation of transcriptional programs, and for late-stage differentiation in this model of early human development.Wellcome Trust (Grant ID: WT093736), Biotechnology and Biological Sciences Research Council (Grant ID: BBS/E/B/000C0402), Medical Research Council (DTG Studentships, Grant ID: MR/J003808/1
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Cognitive tests used in chronic adult human randomised controlled trial micronutrient and phytochemical intervention studies
In recent years there has been a rapid growth of interest in exploring the relationship between nutritional therapies and the maintenance of cognitive function in adulthood. Emerging evidence reveals an increasingly complex picture with respect to the benefits of various food constituents on learning, memory and psychomotor function in adults. However, to date, there has been little consensus in human studies on the range of cognitive domains to be tested or the particular tests to be employed. To illustrate the potential difficulties that this poses, we conducted a systematic review of existing human adult randomised controlled trial (RCT) studies that have investigated the effects of 24 d to 36 months of supplementation with flavonoids and micronutrients on cognitive performance. There were thirty-nine studies employing a total of 121 different cognitive tasks that met the criteria for inclusion. Results showed that less than half of these studies reported positive effects of treatment, with some important cognitive domains either under-represented or not explored at all. Although there was some evidence of sensitivity to nutritional supplementation in a number of domains (for example, executive function, spatial working memory), interpretation is currently difficult given the prevailing 'scattergun approach' for selecting cognitive tests. Specifically, the practice means that it is often difficult to distinguish between a boundary condition for a particular nutrient and a lack of task sensitivity. We argue that for significant future progress to be made, researchers need to pay much closer attention to existing human RCT and animal data, as well as to more basic issues surrounding task sensitivity, statistical power and type I error
The convergence, divergence and changing geography of regulation in the UK's private rented sector
The role of the private rented sector (PRS) has grown in many parts of Europe in recent years, both as an increasing component of housing systems and as the effects of the global financial crisis become apparent. In the UK, the role of the sector has deepened and is increasingly relied upon to house growing and diverse proportions of the population for longer periods of time. This has renewed interest in the regulation of the sector in order to improve its suitability and desirability for tenants. There has been increasing convergence in regulatory approaches between some jurisdictions of the UK, such as Scotland and Wales, and divergence between others, such as England where regulation remains a residual policy concern. Using examples of tenure security, landlord regulation and affordability, this policy review seeks to highlight the emerging differences in the way the PRS is regulated within the UK. It argues that the likely consequence of these differences is that there may be increased variation in the effects and experience of renting in the PRS, in relation to eviction protections and landlord management standards. The paper shows how jurisdictions in Scotland, and to a lesser extent Wales and Northern Ireland, are moving towards models of regulation that more closely mirror those used in Western European countries, with England becoming an outlier in the way in which it regulates private renting
Recollection and familiarity in recognition memory: an event-related fMRI study
The question of whether recognition memory judgments with
and without recollection reflect dissociable patterns of brain activity is unresolved. We used event-related, functional magnetic resonance imaging (fMRI) of 12 healthy volunteers to measure hemodynamic responses associated with both studying and recognizing words. Volunteers made one of three judgments to each word during recognition: whether they recollected seeing it during study (R judgments), whether they experienced a feeling of familiarity in the absence of recollection(K judgments), or whether they did not remember seeing it during study (N judgments). Both R and K judgments for studied words were associated with enhanced responses in left prefrontal and left parietal cortices relative to N judgments for unstudied words. The opposite pattern was observed in bilateral temporoccipital regions and amygdalae. R judgments for studied words were associated with enhanced responses in anterior left prefrontal, left parietal, and posterior cingulate regions relative to K judgments. At study, a posterior left prefrontal region exhibited an enhanced response to words subsequently given R versus K judgments, but the response of this region during recognition did not differentiate R and K judgments. K judgments for studied words were associated with enhanced responses in right lateral and medial prefrontal cortex relative to both R judgments for studied words and N judgments for unstudied words, a difference we attribute to greater monitoring demands when memory judgments are less certain.
These results suggest that the responses of different brain
regions do dissociate according to the phenomenology associated with memory retrieval
How children eat may contribute to rising levels of obesity children's eating behaviours: An intergenerational study of family influences
The term âobesogenic environmentâ is rapidly becoming part of common phraseology. However, the influence of the family and the home environment on children's eating behaviours is little understood. Research that explores the impact of this micro environment and intergenerational influences affecting children's eating behaviours is long overdue. A qualitative, grounded theory approach, incorporating focus groups and semi-structured interviews, was used to investigate the family environment and specifically, the food culture of different generations within families. What emerged was a substantive theory based on âordering of eatingâ that explains differences in eating behaviours within and between families. Whereas at one time family eating was highly ordered and structured, typified by the grandparent generation, nowadays family eating behaviours are more haphazard and less ordered, evidenced by the way the current generation of children eat. Most importantly, in families with an obese child eating is less ordered compared with those families with a normal weight child. Ordering of eating' is a unique concept to emerge. It shows that an understanding of the eating process is crucial to the development and improvement of interventions targeted at addressing childhood obesity within the family context
Impaired cumulus mucification and female sterility in tumor necrosis factor-induced protein-6 deficient mice
Reflections on the 35th BCS Human-Computer Interaction Conference at Keele University
The following are short reflections from interactions gallery chairs, workshops organisers and members of the host organising committee
Characterizing solute hydrogen and hydrides in pure and alloyed titanium at the atomic scale
Ti has a high affinity for hydrogen and are typical hydride formers . Ti -hydride are brittle phases which probably cause premature failure of Ti -alloys. Here, we used atom probe tomography and electron microscopy to investigate the hydrogen di stribution in a set of specimens of commercially pure Ti , model and commercial Ti -alloys. Although likely partly introduced during specimen preparation with the focused- ion beam, we show formation of Ti-hydrides along α grain boundaries and α / ÎČ phase boundaries in commercial pure Ti and α + ÎČ binary model alloys . No hydrides are observed in the α phase in alloys with Al addition or quenched-in Mo supersaturation
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