Cryo-EM structure of a helicase loading intermediate containing ORC-Cdc6-Cdt1-MCM2-7 bound to DNA

In eukaryotes, the Cdt1-bound replicative helicase core MCM2-7 is loaded onto DNA by the ORC-Cdc6 ATPase to form a prereplicative complex (pre-RC) with an MCM2-7 double hexamer encircling DNA. Using purified components in the presence of ATP-γS, we have captured in vitro an intermediate in pre-RC assembly that contains a complex between the ORC-Cdc6 and Cdt1-MCM2-7 heteroheptamers called the OCCM. Cryo-EM studies of this 14-subunit complex reveal that the two separate heptameric complexes are engaged extensively, with the ORC-Cdc6 N-terminal AAA+ domains latching onto the C-terminal AAA+ motor domains of the MCM2-7 hexamer. The conformation of ORC-Cdc6 undergoes a concerted change into a right-handed spiral with helical symmetry that is identical to that of the DNA double helix. The resulting ORC-Cdc6 helicase loader shows a notable structural similarity to the replication factor C clamp loader, suggesting a conserved mechanism of action

Supporting self-management after attending a structured education programme: a qualitative longitudinal investigation of type 1 diabetes patients’ experiences and views

Background: Structured education programmes for patients with diabetes and other chronic conditions are being widely adopted. However, follow-up studies suggest that course graduates may struggle to sustain the self-care practices taught on their courses over time. This study explored the support needs of patients with type 1 diabetes after attending a structured education programme promoting an empowerment approach and training in use of flexible intensive insulin therapy, a regimen now widely advocated and used to manage this condition. The objective was to inform future support offered to course graduates. Methods: Repeat, in-depth interviews with 30 type 1 diabetes patients after attending Dose Adjustment for Normal Eating (DAFNE) courses in the UK, and six and 12 months later. Data were analysed using an inductive, thematic approach. Results: While the flexible intensive insulin treatment approach taught on DAFNE courses was seen as a logical and effective way of managing one’s diabetes, it was also considered more technically complex than other insulin regimens. To sustain effective disease self-management using flexible intensive insulin treatment over time, patients often expected, and needed, on-going input and support from health care professionals trained in the approach. This included: help determining insulin dose adjustments; reassurance; and, opportunities to trouble-shoot issues of concern. While some benefits were identified to receiving follow-up support in a group setting, most patients stated a preference or need for tailored and individualised support from appropriately-trained clinicians, accessible on an ‘as and when needed’ basis. Conclusions: Our findings highlight potential limitations to group-based forms of follow-up support for sustaining diabetes self-management. To maintain the clinical benefits of structured education for patients with type 1 diabetes over time, course graduates may benefit from and prefer ongoing, one-to-one support from health care professionals trained in the programme’s practices and principles. This support should be tailored and personalised to reflect patients’ specific and unique experiences of applying their education and training in the context of their everyday lives, and could be the subject of future research

Evolution of Novel Signal Traits in the Absence of Female Preferences in Neoconocephalus Katydids (Orthoptera, Tettigoniidae)

Background Significance: Communication signals that function to bring together the sexes are important for maintaining reproductive isolation in many taxa. Changes in male calls are often attributed to sexual selection, in which female preferences initiate signal divergence. Natural selection can also influence signal traits if calls attract predators or parasitoids, or if calling is energetically costly. Neutral evolution is often neglected in the context of acoustic communication. Methodology/Principal Findings: We describe a signal trait that appears to have evolved in the absence of either sexual or natural selection. In the katydid genus Neoconocephalus, calls with a derived pattern in which pulses are grouped into pairs have evolved five times independently. We have previously shown that in three of these species, females require the double pulse pattern for call recognition, and hence the recognition system of the females is also in a derived state. Here we describe the remaining two species and find that although males produce the derived call pattern, females use the ancestral recognition mechanism in which no pulse pattern is required. Females respond equally well to the single and double pulse calls, indicating that the derived trait is selectively neutral in the context of mate recognition. Conclusions/Significance: These results suggest that 1) neutral changes in signal traits could be important in the diversification of communication systems, and 2) males rather than females may be responsible for initiating signa

Step detection and activity recognition accuracy of seven physical activity monitors

The aim of this study was to compare the seven following commercially available activity monitors in terms of step count detection accuracy: Movemonitor (Mc Roberts), Up (Jawbone), One (Fitbit), ActivPAL (PAL Technologies Ltd.), Nike+ Fuelband (Nike Inc.), Tractivity (Kineteks Corp.) and Sensewear Armband Mini (Bodymedia). Sixteen healthy adults consented to take part in the study. The experimental protocol included walking along an indoor straight walkway, descending and ascending 24 steps, free outdoor walking and free indoor walking. These tasks were repeated at three self-selected walking speeds. Angular velocity signals collected at both shanks using two wireless inertial measurement units (OPAL, ADPM Inc) were used as a reference for the step count, computed using previously validated algorithms. Step detection accuracy was assessed using the mean absolute percentage error computed for each sensor. The Movemonitor and the ActivPAL were also tested within a nine-minute activity recognition protocol, during which the participants performed a set of complex tasks. Posture classifications were obtained from the two monitors and expressed as a percentage of the total task duration. The Movemonitor, One, ActivPAL, Nike+ Fuelband and Sensewear Armband Mini underestimated the number of steps in all the observed walking speeds, whereas the Tractivity significantly overestimated step count. The Movemonitor was the best performing sensor, with an error lower than 2% at all speeds and the smallest error obtained in the outdoor walking. The activity recognition protocol showed that the Movemonitor performed best in the walking recognition, but had difficulty in discriminating between standing and sitting. Results of this study can be used to inform choice of a monitor for specific applications

Mental practice-based rehabilitation training to improve arm function and daily activity performance in stroke patients: a randomized clinical trial

<p>Abstract</p> <p>Background</p> <p>Over 50% of patients with upper limb paresis resulting from stroke face long-term impaired arm function and ensuing disability in daily life. Unfortunately, the number of effective treatments aimed at improving arm function due to stroke is still low. This study aims to evaluate a new therapy for improving arm function in sub-acute stroke patients based on mental practice theories and functional task-oriented training, and to study the predictors for a positive treatment result. It is hypothesized that a six-week, mental practice-based training program (additional to regular therapy) targeting the specific upper extremity skills important to the individual patient will significantly improve both arm function and daily activity performance, as well as being cost effective.</p> <p>Methods/design</p> <p>One hundred and sixty sub-acute stroke patients with upper limb paresis (MRC grade 1–3) will participate in a single-blinded, multi-centre RCT. The experimental group will undertake a six-week, individually tailored therapy regime focused on improving arm function using mental practice. The control group will perform bimanual upper extremity exercises in addition to regular therapy. Total contact time and training intensity will be similar for both groups. Measurements will be taken at therapy onset, after its cessation and during the follow-up period (after 6 and 12 months). Primary outcome measures will assess upper extremity functioning on the ICF level of daily life activity (Wolf Motor Function Test, Frenchay Arm Test, accelerometry), while secondary outcome measures cover the ICF impairment level (Brunnstrom-Fu-Meyer test). Level of societal participation (IPA) and quality of life (EuroQol; SS-Qol) will also be tested. Costs will be based on a cost questionnaire, and statistical analyses on MAN(C)OVA and GEE (generalized estimated equations).</p> <p>Discussion</p> <p>The results of this study will provide evidence on the effectiveness of this mental practice-based rehabilitation training, as well as the cost-effectiveness.</p> <p>Trial registration</p> <p>Current Controlled Trials [ISRCTN33487341)</p

Tissue Compartment Analysis for Biomarker Discovery by Gene Expression Profiling

BACKGROUND:Although high throughput technologies for gene profiling are reliable tools, sample/tissue heterogeneity limits their outcomes when applied to identify molecular markers. Indeed, inter-sample differences in cell composition contribute to scatter the data, preventing detection of small but relevant changes in gene expression level. To date, attempts to circumvent this difficulty were based on isolation of the different cell structures constituting biological samples. As an alternate approach, we developed a tissue compartment analysis (TCA) method to assess the cell composition of tissue samples, and applied it to standardize data and to identify biomarkers. METHODOLOGY/PRINCIPAL FINDINGS:TCA is based on the comparison of mRNA expression levels of specific markers of the different constitutive structures in pure isolated structures, on the one hand, and in the whole sample on the other. TCA method was here developed with human kidney samples, as an example of highly heterogeneous organ. It was validated by comparison of the data with those obtained by histo-morphometry. TCA demonstrated the extreme variety of composition of kidney samples, with abundance of specific structures varying from 5 to 95% of the whole sample. TCA permitted to accurately standardize gene expression level amongst >100 kidney biopsies, and to identify otherwise imperceptible molecular disease markers. CONCLUSIONS/SIGNIFICANCE:Because TCA does not require specific preparation of sample, it can be applied to all existing tissue or cDNA libraries or to published data sets, inasmuch specific operational compartments markers are available. In human, where the small size of tissue samples collected in clinical practice accounts for high structural diversity, TCA is well suited for the identification of molecular markers of diseases, and the follow up of identified markers in single patients for diagnosis/prognosis and evaluation of therapy efficiency. In laboratory animals, TCA will interestingly be applied to central nervous system where tissue heterogeneity is a limiting factor