Stochastic thermodynamics for Ising chain and symmetric exclusion process.

We verify the finite-time fluctuation theorem for a linear Ising chain in contact with heat reservoirs at its ends. Analytic results are derived for a chain consisting of two spins. The system can be mapped onto a model for particle transport, namely, the symmetric exclusion process in contact with thermal and particle reservoirs. We modify the symmetric exclusion process to represent a thermal engine and reproduce universal features of the efficiency at maximum power.

Comment on "Generalized exclusion processes: Transport coefficients".

In a recent paper, Arita et al. [Phys. Rev. E 90, 052108 (2014)PLEEE81539-375510.1103/PhysRevE.90.052108] consider the transport properties of a class of generalized exclusion processes. Analytical expressions for the transport-diffusion coefficient are derived by ignoring correlations. It is claimed that these expressions become exact in the hydrodynamic limit. In this Comment, we point out that (i) the influence of correlations upon the diffusion does not vanish in the hydrodynamic limit, and (ii) the expressions for the self- and transport diffusion derived by Arita et al. are special cases of results derived in Becker et al. [Phys. Rev. Lett. 111, 110601 (2013)PRLTAO0031-900710.1103/PhysRevLett.111.110601].

Prospective evaluation of the long-term effects of clinical voiding reeducation or voiding school for lower urinary tract conditions in children.

INTRODUCTION: Although the short-term effects of urotherapy as a treatment strategy for lower urinary tract (LUT) conditions have been well documented, the long-term effects remain largely unknown. A better insight into the long-term effects of urotherapy could improve the clinical guidelines for children with incontinence. OBJECTIVE: This study aimed to investigate the long-term effects (i.e., from 6 months to 2 years) from a clinical voiding reeducation program among children with LUT conditions. STUDY DESIGN: This study was a prospective continuation of the follow-up study of Hoebeke et al. (2011). Thirty-eight children (mean age 9 years) with LUT conditions completed an extensive clinical voiding reeducation program (VS). Data on medication, voiding, drinking, pelvic floor tone, uroflowmetry, and incontinence were recorded 2 years after the VS. These data were compared with the outcomes at 6 months follow-up and at intake before voiding school. RESULTS: Six months after voiding school, 22 children continued having daytime incontinence (ID) and/or enuresis (EN). Six of them became dry at 2 years. Conversely, 16 children were dry at 6 months, of which eight relapsed at 2 years. Whereas all parameters significantly improved 6 months after VS, further improvements from 6 months to 2 years could only be noticed for the proportion of children suffering from overactive bladder (92% at intake, 55% at 6-month follow-up and 18% at 2-year follow-up) (Figure). Fluid intake and pelvic floor tone improved after 6 months, but showed a significant relapse after 2 years (P = 0.013, P = 0.031, respectively). DISCUSSION: Hoebeke et al. (2011) concluded that results continued to improve after VS. No further improvements could be noticed 2 years after VS, although individual shifts were present. The results of the present study underline the value of long-term follow-up to detect those needing ongoing treatment to prevent relapse. Fluid intake and pelvic floor tone deteriorated from 6 months to 2 years. It could be hypothesized that inadequate fluid intake, possibly leading to decreased voided volumes, may be seen as an indicator for upcoming incontinence relapse. It could be stated that adequate fluid intake and pelvic floor tone may play a role in remaining continent for the long term. Study limitations should be considered. The study population was heterogeneous and rather small. Together with other missing values, this could have influenced the results. CONCLUSION: Close individual, long-term follow-up after clinical voiding reeducation in children is recommended in order to timely detect and prevent potential relapse.

Stochastic thermodynamics for linear kinetic equations.

Stochastic thermodynamics is formulated for variables that are odd under time reversal. The invariance under spatial rotation of the collision rates due to the isotropy of the heat bath is shown to be a crucial ingredient. An alternative detailed fluctuation theorem is derived, expressed solely in terms of forward statistics. It is illustrated for a linear kinetic equation with kangaroo rates.

An evaluator-blinded randomized controlled trial evaluating therapy effects and prognostic factors for a general and an individually defined physical therapy program in ambulant children with bilateral spastic cerebral palsy.

BACKGROUND: Cerebral palsy (CP) is characterized by a heterogeneous nature with a variety of problems. Therefore, individualized physical therapy might be more appropriate to address the needs for these children. AIM: The first aim was to compare the effectiveness of an individually-defined therapy program (IT) and a general therapy program (GT) on gait and gross motor function in children with CP. The second aim was to evaluate interaction-effects, time-effects, treatment with botulinum toxin A, age, gross Motor Function Classification Scale (GMFCS), treatment frequency and quality as factors influencing outcome. DESIGN: An evaluator-blinded, randomized controlled trial. SETTING: Outpatient rehabilitation unit. POPULATION: Forty ambulant children with spastic bilateral CP (mean age 6 years 1 month). METHODS: All children were randomly assigned to receive either IT or GT over a 10 week period. Nineteen of these children were enrolled into a second and/or third program, resulting in 60 interventions. Primary outcome was assessed with the Goal Attainment Scale (GAS) for gross motor function goals and z-scores for goals based on specific 3D gait parameters. Secondary outcome included the Gross Motor Function Measure-88 (GMFM-88) scores, time and distance gait parameters, Gait Profile Score, Movement Analysis Profiles and time needed to complete Timed-Up-and-Go and Five-Times-Sit-To-Stand tests. RESULTS: There were higher, but non-significant GAS and z-score changes following the IT program compared to the GT program (GAS: 46.2 for the IT versus 42.2 for the GT group, P=0.332, ES 0.15; z-score: 0.135 for the IT compared to 0.072 for the GT group, P=0.669, ES 0.05). Significant time-effects could be found on the GAS (P<0.001) and the GMFM-88 total score (P<0.001). Age was identified as a predictor for GAS and GMFM-88 improvement (P=0.023 and P=0.044). CONCLUSION: No significant differences could be registered between the effects of the IT and the GT. The favorable outcome after the IT program was only a trend and needs to be confirmed on larger groups and with programs of longer duration. CLINICAL REHABILITATION IMPACT: Both programs had a positive impact on the children's motor functioning. It is useful to involve older children more actively in the process of goal setting.

Echo states for detailed fluctuation theorems.

Detailed fluctuation theorems are statements about the probability distribution for the stochastic entropy production along a trajectory. It involves the consideration of a suitably transformed dynamics, such as the time reversed, the adjoint, or a combination of these. We identify specific, typically unique, initial conditions, called echo states, for which the final probability distribution of the transformed dynamics reproduces the initial distribution. In this case the detailed fluctuation theorems relate the stochastic entropy production of the direct process to that of the transformed one. We illustrate our results by an explicit analytical calculation and numerical simulations for a modulated two-state quantum dot.

Diffusion of interacting particles in discrete geometries: Equilibrium and dynamical properties.

We expand on a recent study of a lattice model of interacting particles [Phys. Rev. Lett. 111, 110601 (2013)PRLTAO0031-900710.1103/PhysRevLett.111.110601]. The adsorption isotherm and equilibrium fluctuations in particle number are discussed as a function of the interaction. Their behavior is similar to that of interacting particles in porous materials. Different expressions for the particle jump rates are derived from transition-state theory. Which expression should be used depends on the strength of the interparticle interactions. Analytical expressions for the self- and transport diffusion are derived when correlations, caused by memory effects in the environment, are neglected. The diffusive behavior is studied numerically with kinetic Monte Carlo (kMC) simulations, which reproduces the diffusion including correlations. The effect of correlations is studied by comparing the analytical expressions with the kMC simulations. It is found that the Maxwell-Stefan diffusion can exceed the self-diffusion. To our knowledge, this is the first time this is observed. The diffusive behavior in one-dimensional and higher-dimensional systems is qualitatively the same, with the effect of correlations decreasing for increasing dimension. The length dependence of both the self- and transport diffusion is studied for one-dimensional systems. For long lengths the self-diffusion shows a 1/L dependence. Finally, we discuss when agreement with experiments and simulations can be expected. The assumption that particles in different cavities do not interact is expected to hold quantitatively at low and medium particle concentrations if the particles are not strongly interacting.

Stochastic functionals and fluctuation theorem for multikangaroo processes.

We introduce multikangaroo Markov processes and provide a general procedure for evaluating a certain type of stochastic functional. We calculate analytically the large deviation properties. We apply our results to zero-crossing statistics and to stochastic thermodynamics, including the derivation of the fluctuation theorem and the large deviation properties for the stochastic entropy production in a typical solid state device.

Diffusion of interacting particles in discrete geometries.

We evaluate the self-diffusion and transport diffusion of interacting particles in a discrete geometry consisting of a linear chain of cavities, with interactions within a cavity described by a free-energy function. Exact analytical expressions are obtained in the absence of correlations, showing that the self-diffusion can exceed the transport diffusion if the free-energy function is concave. The effect of correlations is elucidated by comparison with numerical results. Quantitative agreement is obtained with recent experimental data for diffusion in a nanoporous zeolitic imidazolate framework material, ZIF-8.

Quality of life in youngsters with cerebral palsy after single-event multilevel surgery.

UNLABELLED: A single event-multilevel surgery (SEMLS) is today a well-established modality of treatment in children with cerebral palsy (CP). It comprises muscle lengthening/transfers and correction of bony deformities in a single surgical session. Functional improvements after SEMLS have been examined thoroughly, however little is known about the impact of SEMLS on the quality of life (QOL) of children with CP. This study reports on the QOL of children/adolescents with CP after SEMLS. Forty patients underwent SEMLS and were classified according GMFCS levels II-V, age and time span between surgery and questioning. The Cerebral Palsy Quality of Life Questionnaire for Children (CP QOL-Child) and an author developed questionnaire were completed to evaluate QOL. Overall, children/adolescents reported high quality of life scores after SEMLS on the CP QOL-Child. For all the domains of the CP QOL-Child the children reported significant higher scores than their parents (p < 0.05). Significant differences (p < 0.05) were found for the functional-related domains of the CP QOL-Child between GMFCS level III and levels IV-V, but not for the socio-emotional domains. Older children at the moment of surgery (15y0m-18y11m) reported significantly less 'pain and feeling about disability' than children who were younger when operated on (10y0m-14y11m). Almost all aspects included in the author developed questionnaire improved for the majority of the children after SEMLS. CONCLUSION: After SEMLS, children with CP report high quality of life, significantly higher than their parents perceived. Function and age may influence specific aspects of QOL after SEMLS.

Cooling by heating: refrigeration powered by photons.

We propose a new mechanism for refrigeration powered by photons. We identify the strong coupling regime for which maximum efficiency is achieved. In this case, the cooling flux is proportional to T in the low temperature limit T→0.

The effect of different physiotherapy interventions in post-BTX-A treatment of children with cerebral palsy.

AIM: To distinguish the effects of different physiotherapeutic programs in a post BTX-A regime for children with Cerebral Palsy (CP). DESIGN: Retrospective, controlled intervention study. PARTICIPANTS AND INTERVENTIONS: A group of 38 children (X¯ = 7y7m, GMFCS I-III, 27 bilateral, 11 unilateral CP) receiving an individually defined Neurodevelopment Treatment (NDT) program, was matched and compared to a group of children with the same age, GMFCS and diagnosis, receiving more conventional physiotherapy treatment. All patients received selective tone-reduction by means of multilevel BTX-A injections and adequate follow-up treatment, including physiotherapy. OUTCOME MEASURES: Three-dimensional gait analyses and clinical examination was performed pre and two months post-injection. Treatment success was defined using the Goal Attainment Scale (GAS). RESULTS: Both groups' mean converted GAS scores were above 50. The average converted GAS score was higher in the group of children receiving NDT than in the group receiving conventional physiotherapy (p < 0.05). In the NDT group, overall treatment success was achieved in 76% of the goals, compared to 67% of the goals defined for the conventional physiotherapy group. Especially for the goals based on gait analyses (p < 0.05) and in the group of children with bilateral CP (p < 0.05), treatment success was higher in the NDT group. CONCLUSION: In a post-BTX-A regime, the short-term effects of an NDT approach are more pronouncedthan these from a conventional physiotherapy approach.

Prospective evaluation of clinical voiding reeducation or voiding school for lower urinary tract conditions in children.

PURPOSE: We conducted a prospective controlled study evaluating the results of a clinical voiding reeducation program (voiding school) for treatment of lower urinary tract conditions in children compared to no treatment. MATERIALS AND METHODS: A total of 38 children with nonneurogenic lower urinary tract conditions were included in the study. Controls, consisting of 15 children on the waiting list for the same program, received no treatment. The clinical voiding reeducation program consisted of instruction on voiding and drinking, individualized voiding diaries, pelvic floor biofeedback training, uroflowmetry, alarm therapy, cognitive therapy and psychological support. Data on voiding, drinking, pelvic floor control, voided volume, uroflow, incontinence and stool habits were gathered before the program, during the program and 6 months after the program. In the control group the same data were gathered. RESULTS: In the study group a positive effect of voiding school was observed in 92% of children, with 42% becoming completely dry, 24% improving from incontinence during the day and night to incontinence during the day or night only, and 26% remaining incontinent. In all patients the number and amount of incontinence episodes decreased. In the control group no differences were observed between the start of study and 6 months later. The study group did significantly better on voided volume and incontinence compared to controls. CONCLUSIONS: In this prospective controlled study a positive effect was noted on voided volume and incontinence with a clinical voiding reeducation program (voiding school).

The effect of individually defined physiotherapy in children with cerebral palsy (CP).

AIM: This prospective double blind intervention study aims to evaluate the effectiveness of an individually defined physiotherapy program on the function and gait pattern of 16 children with diplegia (age 3-12 year, GMFCS I-II). METHOD: A 6 weeks general training program was followed by a specific training program based on individual goals determined by the results of 3D gait analyses, GMFM-88 and a clinical evaluation. Goal attainment scores were used for the evaluation of the achievement of individual goals. RESULTS: After the general training program, 6.7% of the children achieved the treatment goals, 33.3% stayed at the same level and 60% worsened and this in comparison to 40, 33.3 and 26.6% of the children respectively after the individually defined training program. The improvement for walking, running and jumping of the GMFM-88 was significantly more pronounced after the individually defined (p < 0.05), compared to the general training program. Whereas ankle dorsiflexion, spasticity of the hamstrings (p < 0.01), selectivity of hip abductors, knee extensors and ankle dorsiflexors significantly improved over the complete period of study (p < 0.01), hip extension, step length, stride length, ankle power generation and all hip parameters changed specifically after the individually defined training program (p < 0.01). CONCLUSION: A quantified effect is manifest with the application of an individually defined training program over a six weeks period.

Rectifying the thermal Brownian motion of three-dimensional asymmetric objects.

We extend the analysis of a thermal Brownian motor reported by Van den Broeck [Phys. Rev. Lett. 93, 090601 (2004)] to a three-dimensional configuration. We calculate the friction coefficient, diffusion coefficient, and drift velocity as functions of shape and present estimates based on physically realistic parameter values.

Lower bounds on dissipation upon coarse graining.

By different coarse-graining procedures, we derive lower bounds on the total mean work dissipated in Brownian systems driven out of equilibrium. With several analytically solvable examples, we illustrate how, when, and where the information on the dissipation is captured.

Chiral brownian heat pump.

We present the exact analysis of a chiral Brownian motor and heat pump. Optimization of the construction predicts, for a nanoscale device, frequencies of the order of kHz and cooling rates of the order of femtojoule per second.

Fluctuation theorem for entropy production during effusion of a relativistic ideal gas.

The probability distribution of the entropy production for the effusion of a relativistic ideal gas is calculated explicitly. This result is then extended to include particle and antiparticle pair production and annihilation. In both cases, the fluctuation theorem is verified.

Prevalence, type, distribution, and severity of cerebral palsy in relation to gestational age: a meta-analytic review.

The aim of this review is to determine the relationship between gestational age (GA) and prevalence, type, distribution, and severity of cerebral palsy (CP). Epidemiological studies with cohorts expressed by GA were assessed. A comprehensive meta-analysis and meta-regression was performed on four fetal age categories. Studies of children with CP as a target population were added. Twenty-six articles met the inclusion criteria. The prevalence of CP decreases significantly with increasing GA category: 14.6% at 22 to 27 weeks' gestation, 6.2% at 28 to 31 weeks, 0.7% at 32 to 36 weeks, and 0.1% in term infants. Interestingly, a significant decrease in prevalence of CP starts only from a GA of 27 weeks onwards. In preterm infants, spastic CP is predominant. In term infants, the non-spastic form of CP is more prevalent than in preterm infants. Bilateral spastic CP is most prevalent in both preterm and term infants. However, the proportion of unilateral spastic CP in term infants is substantial. No relationship could be detected between severity of CP and GA. There is a strong need for an international, well-described, and generally accepted classification system for subtypes and severity of CP.

Continuous and discontinuous phase transitions and partial synchronization in stochastic three-state oscillators.

We investigate both continuous (second-order) and discontinuous (first-order) transitions to macroscopic synchronization within a single class of discrete, stochastic (globally) phase-coupled oscillators. We provide analytical and numerical evidence that the continuity of the transition depends on the coupling coefficients and, in some nonuniform populations, on the degree of quenched disorder. Hence, in a relatively simple setting this class of models exhibits the qualitative behaviors characteristic of a variety of considerably more complicated models. In addition, we study the microscopic basis of synchronization above threshold and detail the counterintuitive subtleties relating measurements of time-averaged frequencies and mean-field oscillations. Most notably, we observe a state of suprathreshold partial synchronization in which time-averaged frequency measurements from individual oscillators do not correspond to the frequency of macroscopic oscillations observed in the population.