Polarized Growth in the Absence of F-Actin in Saccharomyces cerevisiae Exiting Quiescence

Polarity establishment and maintenance are crucial for morphogenesis and development. In budding yeast, these two intricate processes involve the superposition of regulatory loops between polarity landmarks, RHO GTPases, actin-mediated vesicles transport and endocytosis. Deciphering the chronology and the significance of each molecular step of polarized growth is therefore very challenging.We have taken advantage of the fact that yeast quiescent cells display actin bodies, a non polarized actin structure, to evaluate the role of F-actin in bud emergence. Here we show that upon exit from quiescence, actin cables are not required for the first steps of polarized growth. We further show that polarized growth can occur in the absence of actin patch-mediated endocytosis. We finally establish, using latrunculin-A, that the first steps of polarized growth do not require any F-actin containing structures. Yet, these structures are required for the formation of a bona fide daughter cell and cell cycle completion. We propose that upon exit from quiescence in the absence of F-actin, secretory vesicles randomly reach the plasma membrane but preferentially dock and fuse where polarity cues are localized, this being sufficient to trigger polarized growth

Systematisation of spatial uncertainties for comparison between a MR and a CT-based radiotherapy workflow for prostate treatments

<p>Abstract</p> <p>Background</p> <p>In the present work we compared the spatial uncertainties associated with a MR-based workflow for external radiotherapy of prostate cancer to a standard CT-based workflow. The MR-based workflow relies on target definition and patient positioning based on MR imaging. A solution for patient transport between the MR scanner and the treatment units has been developed. For the CT-based workflow, the target is defined on a MR series but then transferred to a CT study through image registration before treatment planning, and a patient positioning using portal imaging and fiducial markers.</p> <p>Methods</p> <p>An "open bore" 1.5T MRI scanner, Siemens Espree, has been installed in the radiotherapy department in near proximity to a treatment unit to enable patient transport between the two installations, and hence use the MRI for patient positioning. The spatial uncertainty caused by the transport was added to the uncertainty originating from the target definition process, estimated through a review of the scientific literature. The uncertainty in the CT-based workflow was estimated through a literature review.</p> <p>Results</p> <p>The systematic uncertainties, affecting all treatment fractions, are reduced from 3-4 mm (1Sd) with a CT based workflow to 2-3 mm with a MR based workflow. The main contributing factor to this improvement is the exclusion of registration between MR and CT in the planning phase of the treatment.</p> <p>Conclusion</p> <p>Treatment planning directly on MR images reduce the spatial uncertainty for prostate treatments.</p

Effects of sulfate starvation on agar polysaccharides of Gracilaria species (Gracilariaceae, Rhodophyta) from Morib, Malaysia

The effects of sulfate starvation on the agar characteristics of Gracilaria species was investigated by culturing two red algae from Morib, Malaysia, Gracilaria changii and Gracilaria salicornia in sulfate-free artificial seawater for 5 days. The seaweed samples were collected in October 2012 and March 2013, periods which have significant variation in the amount of rainfall. The agar yields were shown to be independent of sulfate availability, with only 0.60–1.20 % increment in treated G. changii and 0.31–1.40 % increment in treated G. salicornia while their gel strengths did not increase significantly (approximately 5–7 %) after sulfate starvation for both species. The gelling and melting temperatures did not vary between control and treated samples from both species, except for the treated G. changii collected in March 2013. The gel syneresis index of G. salicornia collected in March 2013 increased significantly after sulfate deprivation. Sulfate starvation introduced some variations in the content of 3, 6-anhydrogalactose and total sulfate esters, but the changes did not have a pronounced effect on the physical properties of agar

Neural correlates of socio-emotional perception in 22q11.2 deletion syndrome.

BACKGROUND: Social impairments are described as a common feature of the 22q11.2 deletion syndrome (22q11DS). However, the neural correlates underlying these impairments are largely unknown in this population. In this study, we investigated neural substrates of socio-emotional perception. METHODS: We used event-related functional magnetic resonance imaging (fMRI) to explore neural activity in individuals with 22q11DS and healthy controls during the visualization of stimuli varying in social (social or non-social) or emotional (positive or negative valence) content. RESULTS: Neural hyporesponsiveness in regions of the default mode network (inferior parietal lobule, precuneus, posterior and anterior cingulate cortex and frontal regions) in response to social versus non-social images was found in the 22q11DS population compared to controls. A similar pattern of activation for positive and negative emotional processing was observed in the two groups. No correlation between neural activation and social functioning was observed in patients with the 22q11DS. Finally, no social × valence interaction impairment was found in patients. CONCLUSIONS: Our results indicate atypical neural correlates of social perception in 22q11DS that appear to be independent of valence processing. Abnormalities in the social perception network may lead to social impairments observed in 22q11DS individuals

The Intensive Diet and Exercise for Arthritis (IDEA) trial: design and rationale

Background: Obesity is the most modifiable risk factor, and dietary induced weight loss potentially the best nonpharmacologic intervention to prevent or to slow osteoarthritis (OA) disease progression. We are currently conducting a study to test the hypothesis that intensive weight loss will reduce inflammation and joint loads sufficiently to alter disease progression, either with or without exercise. This article describes the intervention, the empirical evidence to support it, and test-retest reliability data. Methods/Design: This is a prospective, single-blind, randomized controlled trial. The study population consists of 450 overweight and obese (BMI = 27-40.5 kg/m2) older (age greater than or equal to 55 yrs) adults with tibiofemoral osteoarthritis. Participants are randomized to one of three 18-month interventions: intensive dietary restriction-plus-exercise; exercise-only; or intensive dietary restriction-only. The primary aims are to compare the effects of these interventions on inflammatory biomarkers and knee joint loads. Secondary aims will examine the effects of these interventions on function, pain, and mobility; the dose response to weight loss on disease progression; if inflammatory biomarkers and knee joint loads are mediators of the interventions; and the association between quadriceps strength and disease progression. Results: Test-retest reliability results indicated that the ICCs for knee joint load variables were excellent, ranging from 0.86 - 0.98. Knee flexion/extension moments were most affected by BMI, with lower reliability with the highest tertile of BMI. The reliability of the semi-quantitative scoring of the knee joint using MRI exceeded previously reported results, ranging from a low of 0.66 for synovitis to a high of 0.99 for bone marrow lesion size. Discussion: The IDEA trial has the potential to enhance our understanding of the OA disease process, refine weight loss and exercise recommendations in this prevalent disease, and reduce the burden of disability. Originally published BMC Musculoskeletal Disorders, Vol. 10, No. 93, July 200

Half-Time Strategies to Enhance Second-Half Performance in Team-Sports Players: A Review and Recommendations

The competitive demands of numerous intermittent team sports require that two consecutive periods of play are separated by a half-time break. Typically, half-time allows players to: return to the changing rooms, temporarily relax from the cognitive demands of the first half of match-play, rehydrate, re-fuel, attend to injury or equipment concerns, and to receive tactical instruction and coach feedback in preparation for the second half. These passive practices have been associated with physiological changes which impair physical and cognitive performance in the initial stages of the second half. An increased risk of injury has also been observed following half-time. On the day of competition, modification of half-time practices may therefore provide Sports Scientists and Strength and Conditioning Coaches with an opportunity to optimise second half performance. An overview of strategies that may benefit team sports athletes is presented; specifically, the efficacy of: heat maintenance strategies (including passive and active methods), hormonal priming (through video feedback), post-activation potentiation, and modified hydro-nutritional practices are discussed. A theoretical model of applying these strategies in a manner that compliments current practice is also presented

Efficacy of a multifaceted podiatry intervention to improve balance and prevent falls in older people: study protocol for a randomised trial

<p>Abstract</p> <p>Background</p> <p>Falls in older people are a major public health problem, with at least one in three people aged over 65 years falling each year. There is increasing evidence that foot problems and inappropriate footwear increase the risk of falls, however no studies have been undertaken to determine whether modifying these risk factors decreases the risk of falling. This article describes the design of a randomised trial to evaluate the efficacy of a multifaceted podiatry intervention to reduce foot pain, improve balance, and reduce falls in older people.</p> <p>Methods</p> <p>Three hundred community-dwelling men and women aged 65 years and over with current foot pain and an increased risk of falling will be randomly allocated to a control or intervention group. The "usual cae" control group will receive routine podiatry (i.e. nail care and callus debridement). The intervention group will receive usual care plus a multifaceted podiatry intervention consisting of: (i) prefabricated insoles customised to accommodate plantar lesions; (ii) footwear advice and assistance with the purchase of new footwear if current footwear is inappropriate; (iii) a home-based exercise program to strengthen foot and ankle muscles; and (iv) a falls prevention education booklet. Primary outcome measures will be the number of fallers, number of multiple fallers and the falls rate recorded by a falls diary over a 12 month period. Secondary outcome measures assessed six months after baseline will include the Medical Outcomes Study Short Form 12 (SF-12), the Manchester Foot Pain and Disability Index, the Falls Efficacy Scale International, and a series of balance and functional tests. Data will be analysed using the intention to treat principle.</p> <p>Discussion</p> <p>This study is the first randomised trial to evaluate the efficacy of podiatry in improving balance and preventing falls. The trial has been pragmatically designed to ensure that the findings can be generalised to clinical practice. If found to be effective, the multifaceted podiatry intervention will be a unique addition to common falls prevention strategies already in use.</p> <p>Trial registration</p> <p>Australian New Zealand Clinical Trials Registry: ACTRN12608000065392</p