An original piecewise model for computing energy expenditure from accelerometer and heart rate signals

OBJECTIVE

Activity energy expenditure (EE) plays an important role in healthcare, therefore, accurate EE measures are required. Currently available reference EE acquisition methods, such as doubly labeled water and indirect calorimetry, are complex, expensive, uncomfortable, and/or difficult to apply on real time. To overcome these drawbacks, the goal of this paper is to propose a model for computing EE in real time (minute-by-minute) from heart rate and accelerometer signals.

APPROACH

The proposed model, which consists of an original branched model, uses heart rate signals for computing EE on moderate to vigorous physical activities and a linear combination of heart rate and counts per minute for computing EE on light to moderate physical activities. Model parameters were estimated from a given data set composed of 53 subjects performing 25 different physical activities (light-, moderate- and vigorous-intensity), and validated using leave-one-subject-out. A different database (semi-controlled in-city circuit), was used in order to validate the versatility of the proposed model. Comparisons are done versus linear and nonlinear models, which are also used for computing EE from accelerometer and/or HR signals.

MAIN RESULTS

The proposed piecewise model leads to more accurate EE estimations ([Formula: see text], [Formula: see text] and [Formula: see text] J kg^-1 min^-1 and [Formula: see text], [Formula: see text], and [Formula: see text] J kg^-1 min^-1 on each validation database).

SIGNIFICANCE

This original approach, which is more conformable and less expensive than the reference methods, allows accurate EE estimations, in real time (minute-by-minute), during a large variety of physical activities. Therefore, this model may be used on applications such as computing the time that a given subject spent on light-intensity physical activities and on moderate to vigorous physical activities (binary classification accuracy of 0.8155).

Exercise training improves fat metabolism independent of total energy expenditure in sedentary overweight men, but does not restore lean metabolic phenotype

BACKGROUND

Obesity is a dietary fat storage disease. Although exercise prevents weight gain, effects of chronic training on dietary fat oxidation remains understudied in overweight adults.

OBJECTIVE

We tested whether 2 months of training at current guidelines increase dietary fat oxidation in sedentary overweight adults like in sedentary lean adults.

DESIGN

Sedentary lean (n=10) and overweight (n=9) men trained on a cycle ergometer at 50% VO_2peak, 1 h day^-1, four times per week, for 2 months while energy balance was clamped. Metabolic fate of [d₃₁]palmitate and [1-¹³C]oleate mixed in standard meals, total substrate use, total energy expenditure (TEE), activity energy expenditure (AEE) and key muscle proteins/enzymes were measured before and at the end of the intervention.

RESULTS

Conversely to lean subjects, TEE and AEE did not increase in overweight participants due to a spontaneous decrease in non-training AEE. Despite this compensatory behavior, aerobic fitness, insulin sensitivity and fat oxidation were improved by exercise training. The latter was not explained by changes in dietary fat trafficking but more likely by a coordinated response at the muscle level enhancing fat uptake, acylation and oxidation (FABPpm, CD36, FATP1, ACSL1, CPT1, mtGPAT). ACSL1 fold change positively correlated with total fasting (R²=0.59, P<0.0001) and post-prandial (R²=0.49, P=0.0006) fat oxidation whereas mtGPAT fold change negatively correlated with dietary palmitate oxidation (R²=0.40, P=0.009), suggesting modified fat trafficking between oxidation and storage within the muscle. However, for most of the measured parameters the post-training values observed in overweight adults remained lower than the pre-training values observed in the lean subjects.

CONCLUSION

Independent of energy balance and TEE, exercise training at current recommendations improved fitness and fat oxidation in overweight adults. However the improved metabolic phenotype of overweight adults was not as healthy as the one of their lean counterparts before the 2-month training, likely due to the spontaneous reduction in non-training AEE.

Optomechanical proposal for monitoring microtubule mechanical vibrations

Microtubules provide the mechanical force required for chromosome separation during mitosis. However, little is known about the dynamic (high-frequency) mechanical properties of microtubules. Here, we theoretically propose to control the vibrations of a doubly clamped microtubule by tip electrodes and to detect its motion via the optomechanical coupling between the vibrational modes of the microtubule and an optical cavity. In the presence of a red-detuned strong pump laser, this coupling leads to optomechanical-induced transparency of an optical probe field, which can be detected with state-of-the art technology. The center frequency and line width of the transparency peak give the resonance frequency and damping rate of the microtubule, respectively, while the height of the peak reveals information about the microtubule-cavity field coupling. Our method opens the new possibilities to gain information about the physical properties of microtubules, which will enhance our capability to design physical cancer treatment protocols as alternatives to chemotherapeutic drugs.

[Lung transplantation in Reunion Island, current situation from January 2005 till May 2015]

Lung transplantation (LT) is a therapeutic option for patients with terminal respiratory failure and high risk of mortality in two years. Until now, this activity is not performed in Reunion Island. The candidate potential are thus directed to the metropolitan reference centres causing logistics and financials constraints. This work presents a current situation of the pulmonary transplantation in Reunion Island. This retrospective study includes patients from Reunion Island with respiratory insufficiency who have been transferred to metropolitan centres to apply to LT. The selection was made from January, 2005 till May, 2015. Twenty-nine patients included, aged from 14 to 64 years, were transferred to metropolitan France: 13 patients with cystic fibrosis, 13 patients with pulmonary fibrosis, 1 patients with bronchiectasis, 1 patient with chronic obstructive pulmonary disease (COPD) and 1 patient with pulmonary arterial hypertension. Fifteen patients underwent LT (4 live in Reunion Island, 5 live in metropolitan France and 6 are dead), 1 patient is alive on waiting list, 3 died on the waiting list, 7 patients were refused for transplantation and 3 patients are lost to follow-up. The number of patients transferred for LT increases over 10 years with a maximal incidence in 2013 of 7 repatriated patients including 3 transplanted patients. LT could be performed in half of our patients with possible come back and follow-up on Reunion Island. Indications follow the current trends except an under representation of COPD.

Assessment of methods of detection of water estrogenicity for their use as monitoring tools in a process of estrogenicity removal

Methods of monitoring of estrogenicity in water were gathered, compared, and tested within the context of their practical use as measurement and design tools, in the development of a process of degradation of estrogenic endocrine disruptors. In this work, the focus was put on in vitro assays, with the use of analytical techniques as additional analysis when possible. Practically, from a literature review, four methods that seemed most suitable to practical use required in a process development were tested: the Yeast Estrogen Screen assay, the Lyticase-assisted Yeast Estrogen Screen assay (LYES), the MMV-LUC assay and the HPLC-UV analytical method. Dose-response curves in response to estrogenic standard 17β-estradiol were compared. Bisphenol A estrogenicity was measured by the methods as well. The model for the calculation of estradiol equivalents as measurements units was adapted. The methods were assessed in terms of ranges of detection, time of experiment, cost, ease of the experiment, reproducibility, etc. Based on that assessment, the LYES assay was selected and successfully applied to the monitoring of estrogenicity removal from 17β-estradiol and bisphenol A. More precisely, the bioassay allowed the acquisition of kinetic curves for a laboratory-scaled process of estrogenicity removal by immobilized enzymes in a continuous packed-bed reactor. The LYES assay was found to have a real methodological potential for scale-up and design of a treatment process. The HPLC-UV method showed good complementarity with the LYES assay for the monitoring of bisphenol A concentrations in parallel with estrogenicity, reporting no significant estrogenicity from degradation byproducts, among others.

[Percutaneous embolization and ultrasound scissors for removal of a carotid body tumor]

Paragangliomas are highly vascularized usually benign neoplasms originating from the sympathoadrenal and parasympathetic paraganglia of the autonomic nervous system. When resectable, the management of these tumors consists of surgical ablation preceded by transarterial embolization. The aim of this article is to describe a novel treatment strategy combining intralesional percutaneous embolization with dissection using ultrasound scissors. The case of a 74-year-old women presenting with a Shamblin type III carotid body paraganglioma is presented. The combined approach of percutaneous embolization and ultrasound scissors permitted complete resection of the tumor with preservation of both the internal and external carotid artery, without postoperative cranial nerve deficits and with minimal blood loss. Preoperative intralesional embolization with a liquid embolic agent less than 24 h prior to surgical intervention in combination with ultrasound scissors appears to be an excellent strategy for surgical management of carotid body paragangliomas.

[New aspects in the treatment of thyroid cancer : Highlights of the ASCO Annual Meeting 2016]

The annual meeting of the American Society of Clinical Oncology (ASCO) took place at the beginning of June 2016 in Chicago. This year a total of 28 studies on the treatment of patients with thyroid cancer were presented, described in this review article according to the degree of cancer cell differentiation. The leading curative treatment modality is still surgery. In contrast, kinase inhibitors are being used increasingly within palliative concepts. The latest state of the art of thyroid cancer treatment, both surgical and medical, is summarized in this review.

Evidence of Coherent K^{+} Meson Production in Neutrino-Nucleus Scattering

Neutrino-induced charged-current coherent kaon production ν_{μ}A→μ^{-}K^{+}A is a rare, inelastic electroweak process that brings a K^{+} on shell and leaves the target nucleus intact in its ground state. This process is significantly lower in rate than the neutrino-induced charged-current coherent pion production because of Cabibbo suppression and a kinematic suppression due to the larger kaon mass. We search for such events in the scintillator tracker of MINERvA by observing the final state K^{+}, μ^{-}, and no other detector activity, and by using the kinematics of the final state particles to reconstruct the small momentum transfer to the nucleus, which is a model-independent characteristic of coherent scattering. We find the first experimental evidence for the process at 3σ significance.