Adult stem cell maintenance and tissue regeneration around the clock: do impaired stem cell clocks drive age-associated tissue degeneration?

Human adult stem cell research is a highly prolific area in modern tissue engineering as these cells have significant potential to provide future cellular therapies for the world’s increasingly aged population. Cellular therapies require a smart biomaterial to deliver and localise the cell population; protecting and guiding the stem cells toward predetermined lineage-specific pathways. The cells, in turn, can provide protection to biomaterials and increase its longevity. The right combination of stem cells and biomaterials can significantly increase the therapeutic efficacy. Adult stem cells are utilised to target many changes that negatively impact tissue functions with age. Understanding the underlying mechanisms that lead to changes brought about by the ageing process is imperative as ageing leads to many detrimental effects on stem cell activation, maintenance and differentiation. The circadian clock is an evolutionarily conserved timing mechanism that coordinates physiology, metabolism and behavior with the 24 h solar day to provide temporal tissue homeostasis with the external environment. Circadian rhythms deteriorate with age at both the behavioural and molecular levels, leading to age-associated changes in downstream rhythmic tissue physiology in humans and rodent models. In this review, we highlight recent advances in our knowledge of the role of circadian clocks in adult stem cell maintenance, driven by both cell-autonomous and tissue-specific factors, and the mechanisms by which they co-opt various cellular signaling pathways to impose temporal control on stem cell function. Future research investigating pharmacological and lifestyle interventions by which circadian rhythms within adult stem niches can be manipulated will provide avenues for temporally guided cellular therapies and smart biomaterials to ameliorate age-related tissue deterioration and reduce the burden of chronic disease

Mechanical stretch and chronotherapeutic techniques for progenitor cell transplantation and biomaterials

In the body, mesenchymal progenitor cells are subjected to a substantial amount external force from different mechanical stresses, each potentially influences their behaviour and maintenance differentially. Tensile stress, or compression loading are just two of these forces, and here we examine the role of cyclical or dynamic mechanical loading on progenitor cell proliferation and differentiation, as well as on other cellular processes including cell morphology, apoptosis and matrix mineralisation. Moreover, we also examine how mechanical stretch can be used to optimise and ready biomaterials before their implantation, and examine the role of the circadian rhythm, the body’s innate time keeping system, on biomaterial delivery and acceptance. Finally, we also investigate the effect of mechanical stretch on the circadian rhythm of progenitor cells, as research suggests that mechanical stimulation may be sufficient in itself to synchronise the circadian rhythm of human adult progenitor cells alone, and has also been linked to progenitor cell function. If proven correct, this could offer a novel, non- intrusive method by which human adult progenitor cells may be activated or preconditioned, being readied for differentiation, so that they may be more successfully integrated within a host body, thereby improving tissue engineering techniques and the efficacy of cellular therapies

Global data for ecology and epidemiology: a novel algorithm for temporal Fourier processing MODIS data

Background. Remotely-sensed environmental data from earth-orbiting satellites are increasingly used to model the distribution and abundance of both plant and animal species, especially those of economic or conservation importance. Time series of data from the MODerate-resolution Imaging Spectroradiometer (MODIS) sensors on-board NASA's Terra and Aqua satellites offer the potential to capture environmental thermal and vegetation seasonality, through temporal Fourier analysis, more accurately than was previously possible using the NOAA Advanced Very High Resolution Radiometer (AVHRR) sensor data. MODIS data are composited over 8- or 16-day time intervals that pose unique problems for temporal Fourier analysis. Applying standard techniques to MODIS data can introduce errors of up to 30% in the estimation of the amplitudes and phases of the Fourier harmonics. Methodology/Principal Findings. We present a novel spline-based algorithm that overcomes the processing problems of composited MODIS data. The algorithm is tested on artificial data generated using randomly selected values of both amplitudes and phases, and provides an accurate estimate of the input variables under all conditions. The algorithm was then applied to produce layers that capture the seasonality in MODIS data for the period from 2001 to 2005. Conclusions/Significance. Global temporal Fourier processed images of 1 km MODIS data for Middle Infrared Reflectance, day- and night-time Land Surface Temperature (LST), Normalised Difference Vegetation Index (NDVI), and Enhanced Vegetation Index (EVI) are presented for ecological and epidemiological applications. The finer spatial and temporal resolution, combined with the greater geolocational and spectral accuracy of the MODIS instruments, compared with previous multi-temporal data sets, mean that these data may be used with greater confidence in species' distribution modelling

Comparing circadian dynamics in primary derived stem cells from different sources of human adult tissue

Optimising cell/tissue constructs so that they can be successfully accepted and integrated within a host body is essential in modern tissue engineering. To do this, adult stem cells are frequently utilised, but there are many aspects of their environment in vivo that are not completely understood. There is evidence to suggest that circadian rhythms and daily circadian temporal cues have substantial effects on stem cell activation, cell cycle, and differentiation. It was hypothesised that the circadian rhythm in human adult stem cells differs depending on the source of tissue and that different entraining signals exert differential effects depending on the anatomical source. Dexamethasone and rhythmic mechanical stretch were used to synchronise stem cells derived from the bone marrow, tooth dental pulp, and abdominal subcutaneous adipose tissue, and it was experimentally evidenced that these different stem cells differed in their circadian clock properties in response to different synchronisation mechanisms. The more primitive dental pulp-derived stem cells did not respond as well to the chemical synchronisation but showed temporal clock gene oscillations following rhythmic mechanical stretch, suggesting that incorporating temporal circadian information of different human adult stem cells will have profound implications in optimising tissue engineering approaches and stem cell therapies

Quantification and correction of distortion in diffusion-weighted MRI at 1.5 and 3 T in a muscle-invasive bladder cancer phantom for radiotherapy planning

OBJECTIVE: Limited visibility of post-resection muscle-invasive bladder cancer (MIBC) on CT hinders radiotherapy dose escalation of the residual tumour. Diffusion-weighted MRI (DW-MRI) visualises areas of high tumour burden and is increasingly used within diagnosis and as a biomarker for cancer. DW-MRI could, therefore, facilitate dose escalation, potentially via dose-painting and/or accommodating response. However, the distortion inherent in DW-MRI could limit geometric accuracy. Therefore, this study aims to quantify DW-MRI distortion via imaging of a bladder phantom. METHODS: A phantom was designed to mimic MIBC and imaged using CT, DW-MRI and T2W-MRI. Fiducial marker locations were compared across modalities and publicly available software was assessed for correction of magnetic susceptibility-related distortion. RESULTS: Fiducial marker locations on CT and T2W-MRI agreed within 1.2 mm at 3 T and 1.8 mm at 1.5 T. The greatest discrepancy between CT and apparent diffusion coefficient (ADC) maps was 6.3 mm at 3 T, reducing to 1.8 mm when corrected for distortion. At 1.5 T, these values were 3.9 mm and 1.7 mm, respectively. CONCLUSIONS: Geometric distortion in DW-MRI of a model bladder was initially >6 mm at 3 T and >3 mm at 1.5 T; however, established correction methods reduced this to <2 mm in both cases. ADVANCES IN KNOWLEDGE: A phantom designed to mimic MIBC has been produced and used to show distortion in DW-MRI can be sufficiently mitigated for incorporation into the radiotherapy pathway. Further investigation is therefore warranted to enable individually adaptive image-guided radiotherapy of MIBC based upon DW-MRI

Understanding independent living customers at Trafford Housing Trust : an evaluation

This report provides the findings of the evaluation of TrustCare, an independent arm of Trafford Housing Trust which offers independent living services. The report offers the findings of the evaluation reporting on each stage of the process and drawing on both quantitative (descriptive statistics) and qualitative data (semi-structured interviews) collected during July and August 2017

Masculinity, racism, social support, and colorectal cancer screening uptake among African American men: A systematic review

Colorectal cancer (CRC) is highly preventable when CRC screening is utilized, yet CRC screening completion among African American men is relatively low and their mortality rates remain 50% higher juxtaposed to their White counterparts. Since a growing body of literature indicates masculinity, racism, and social support each have strong influences on CRC screening uptake, this systematic review examined the connections between these three sociocultural factors and CRC screening uptake among African American men. Potential studies were retrieved from MEDLINE, CINAHL, EMBASE, and PsycINFO. Cited reference searching for the final sample was employed to identify and assess additional studies for inclusion using Scopus. The methodological quality of the reviewed evidence was also evaluated. Nineteen studies met inclusion/exclusion criteria. Thirteen studies employed nonexperimental research designs; a quasi-experimental design was present in four, and two utilized experimental designs. Studies were published between 2000 and 2014; the majority between 2009 and 2013. Social support was most frequently addressed (84%) while masculinity and racism were equally studied with paucity (11%) for their influence on CRC screening. After evaluating conceptual and methodological characteristics of the studies, 42% fell below average in quality and rigor. The need for increased attention to the sociocultural correlates of CRC screening for African American men are highlighted in this systematic review, and important recommendations for research and practice are provided. Alongside a call for more rigorous research, further research examining the influence of masculinity and racism on CRC screening completion among African American men is warrante

Do body condition and plumage during fuelling predict northwards departure dates of Great Knots Calidris tenuirostris from north-west Australia?

It is often assumed that strong selection pressures give rise to trade-offs between body condition and time in long-distance migrating birds. Birds that are 'behind schedule' in fuel deposition or moult should delay departure, and this should result in a negative correlation between initial condition and departure date. We tested this hypothesis in the Great Knot Calidris tenuirostris migrating from north-west Australia to eastern Asia en route to Siberia. Great Knot gain mass and moult into breeding plumage before leaving northern Australia in late March and early April, and fly 5400-6000 km to eastern China and Korea. We radiotracked 27 individuals (17 males and ten females) to determine departure dates; 23 migrated and four remained in Australia. We characterized body condition at capture using body mass, predicted pectoral muscle mass (based on ultrasound estimates of the size of the pectoral muscles) and breeding plumage scores. Residual condition indices were uncorrelated, indicating that at the individual level, variation in one fuelling component was not strongly associated with variation in the other components. Birds that did not depart had lower residual body mass and breeding plumage indices than those that did migrate; these four birds may have been subadults. Neither sex, size nor the condition indices explained variation in departure date of migrants. Reasons for this are explored. Departure dates for northward migrating waders indicate that the migration window (span over which birds depart) decreases with proximity to the northern breeding grounds. We suggest that migration schedules become tighter as birds get nearer to the breeding grounds. Thus the lack of a relationship between condition and departure date in Great Knots may reflect the fact that the departure episode under study is the first one in sequence and is still 4-8 weeks before breeding