26,328 research outputs found
Flexibility and development of mirroring mechanisms
The empirical support for the SCM is mixed. We review recent results from our own lab and others supporting a central claim of SCM that mirroring occurs at multiple levels of representation. By contrast, the model is silent as to why human infants are capable of showing imitative behaviours mediated by a mirror system. This limitation is a problem with formal models that address neither the neural correlates nor the behavioural evidence directly
Computer program offers new method for constructing periodic orbits in nonlinear dynamical systems
Computer program uses an iterative method to construct precisely periodic orbits which dynamically approximate solutions that converge to precise dynamical solutions in the limit of the sequence. The method used is a modification of the generalized Newton-Raphson algorithm used in analyzing two point boundary problems
Energy-dependent quenching adjusts the excitation diffusion length to regulate photosynthetic light harvesting
An important determinant of crop yields is the regulation of photosystem II
(PSII) light harvesting by energy-dependent quenching (qE). However, the
molecular details of excitation quenching have not been quantitatively
connected to the PSII yield, which only emerges on the 100 nm scale of the
grana membrane and determines flux to downstream metabolism. Here, we
incorporate excitation dissipation by qE into a pigment-scale model of
excitation transfer and trapping for a 200 nm x 200 nm patch of the grana
membrane. We demonstrate that single molecule measurements of qE are consistent
with a weak-quenching regime. Consequently, excitation transport can be
rigorously coarse-grained to a 2D random walk with an excitation diffusion
length determined by the extent of quenching. A diffusion-corrected lake model
substantially improves the PSII yield determined from variable chlorophyll
fluorescence measurements and offers an improved model of PSII for
photosynthetic metabolism.Comment: 19 pages, 4 figures, 3 supplementary figure
Method for constructing periodic orbits in nonlinear dynamic systems
Method is modification of generalized Newton-Ralphson algorithm for analyzing two-point boundary problems. It constructs sequence of solutions that converge to precise dynamic solution in the sequence limit. Program calculates periodic orbits in either circular or elliptical restricted three-body problems
Transcutaneous electrical nerve stimulation for cancer pain in adults.
Background Cancer-related pain is complex and multi-dimensional but the mainstay of cancer pain management has predominately used a biomedical approach. There is a need for non-pharmacological and innovative approaches. Transcutaneous Electric Nerve Stimulation (TENS) may have a role for a significant number of patients but the effectiveness of TENS is currently unknown. Objectives The aim of this systematic review was to determine the effectiveness of TENS for cancer-related pain in adults. Search strategy We searched The Cochrane Library, MEDLINE, EMBASE, CINAHL, PsychINFO, AMED and PEDRO databases (11/04/08). Selection criteria Only randomised controlled trials (RCTS) investigating the use of TENS for the management of cancer-related pain in adults were included. Data collection and analysis The search strategy identified 37 possible published studies which were divided between two pairs of review authors that decided on study selection. A study eligibility form was used to screen each abstract and where study eligibility could not be determined from the abstract, the full paper was obtained and assessed by one pair of review authors. A standardised data extraction sheet was used to collect information on the studies and the quality of the studies was assessed independently by two review authors using the validated five-point Oxford Quality Scale. Final scores were discussed and agreed between all four review authors. The small sample sizes and differences in patient study populations of the two included studies prevented meta-analysis. Main results Only two RCTs met the eligibility criteria (64 participants). These studies were heterogenous with respect to study population, sample size, study design, methodological quality, mode of TENS, treatment duration, method of administration and outcome measures used. In one RCT, there were no significant differences between TENS and placebo in women with chronic pain secondary to breast cancer treatment. In the other RCT, there were no significant differences between acupuncture-type TENS and sham in palliative care patients; this study was underpowered. Authors' conclusions The results of this systematic review are inconclusive due to a lack of suitable RCTs. Large multi-centre RCTs are required to assess the value of TENS in the management of cancer-related pain in adults
Psychological interventions for mental health disorders in children with chronic physical illness: a systematic review.
Children with chronic physical illness are significantly more likely to develop common psychiatric symptoms than otherwise healthy children. These children therefore warrant effective integrated healthcare yet it is not established whether the known, effective, psychological treatments for symptoms of common childhood mental health disorders work in children with chronic physical illness
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