Melatonin ingestion after exhaustive late-evening exercise improves sleep quality and quantity,and short-term performances in teenage athletes

ABSTRACT

The present study aimed to explore the effects of a single 10-mg dose of melatonin (MEL) administration after exhaustive late-evening exercise on sleep quality and quantity, and short-term physical and cognitive performances in healthy teenagers. Ten male adolescent athletes (mean ± SD, age = 15.4 ± 0.3 years, body-mass = 60.68 ± 5.7 kg, height = 167.9 ± 6.9 cm and BMI = 21.21 ± 2.5) performed two test sessions separated by at least one week. During each session, participants completed the Yo-Yo intermittent-recovery-test level-1 (YYIRT-1) at ~20:00 h. Then, sleep polysomnography was recorded from 22:15 min to 07:00 h, after a double blind randomized order administration of a single 10-mg tablet of MEL (MEL-10 mg) or Placebo (PLA). The following morning, Hooper wellness index was administered and the participants performed the Choice Reaction Time (CRT) test, the Zazzo test and some short-term physical exercises (YYIRT-1, vertical and horizontal Jumps (VJ; HJ), Hand grip strength (HG), and five-jump test (5-JT)). Evening total distance covered in the YYIRT-1 did not change during the two conditions (p > 0.05). Total sleep time (Δ = 24.55 mn; p < 0.001), sleep efficiency (Δ = 4.47%; p < 0.001), stage-3 sleep (N3 sleep) (Δ = 1.73%; p < 0.05) and rapid-eye-movement sleep (Δ = 2.15%; p < 0.001) were significantly higher with MEL in comparison with PLA. Moreover, sleep-onset-latency (Δ = –8.45mn; p < 0.001), total time of nocturnal awakenings after sleep-onset (NA) (Δ = –11 mn; p < 0.001), stage-1 sleep (N1 sleep) (Δ = –1.7%; p < 0.001) and stage-2 sleep (N2 sleep) (Δ = ?1.9%; p < 0.05) durations were lower with MEL. The Hooper index showed a better subjective sleep quality, a decrease of the subjective perception of fatigue and a reduced level of muscle soreness with MEL. Moreover, MEL improved speed and performance but not inaccuracy during the Zazzo test. CRT was faster with MEL. Morning YYIRT-1 (Δ = 82 m; p < 0.001) and 5-JT (Δ = 0.08 m; p < 0.05) performances were significantly higher with MEL in comparison with PLA. In contrast, HG, VJ and HJ performances did not change during the two conditions (p > 0.05). The administration of a single dose of MEL-10 mg after strenuous late-evening exercise improved sleep quality and quantity, selective attention, subjective assessment of the general wellness state, and some short-term physical performances the following morning in healthy teenagers.     

Screening and Characterization of RAPD Markers in Viscerotropic Leishmania Parasites

Visceral leishmaniasis (VL) is mainly due to the Leishmania donovani complex. VL is endemic in many countries worldwide including East Africa and the Mediterranean region where the epidemiology is complex. Taxonomy of these pathogens is under controversy but there is a correlation between their genetic diversity and geographical origin. With steady increase in genome knowledge, RAPD is still a useful approach to identify and characterize novel DNA markers. Our aim was to identify and characterize polymorphic DNA markers in VL Leishmania parasites in diverse geographic regions using RAPD in order to constitute a pool of PCR targets having the potential to differentiate among the VL parasites. 100 different oligonucleotide decamers having arbitrary DNA sequences were screened for reproducible amplification and a selection of 28 was used to amplify DNA from 12 L. donovani, L. archibaldi and L. infantum strains having diverse origins. A total of 155 bands were amplified of which 60.65% appeared polymorphic. 7 out of 28 primers provided monomorphic patterns. Phenetic analysis allowed clustering the parasites according to their geographical origin. Differentially amplified bands were selected, among them 22 RAPD products were successfully cloned and sequenced. Bioinformatic analysis allowed mapping of the markers and sequences and priming sites analysis. This study was complemented with Southern-blot to confirm assignment of markers to the kDNA. The bioinformatic analysis identified 16 nuclear and 3 minicircle markers. Analysis of these markers highlighted polymorphisms at RAPD priming sites with mainly 5′ end transversions, and presence of inter– and intra– taxonomic complex sequence and microsatellites variations; a bias in transitions over transversions and indels between the different sequences compared is observed, which is however less marked between L. infantum and L. donovani. The study delivers a pool of well-documented polymorphic DNA markers, to develop molecular diagnostics assays to characterize and differentiate VL causing agents.     

Manganese Superoxide Dismutase (SOD2) Polymorphisms,Plasma Advanced Oxidation Protein Products (AOPP) Concentration and Risk of Kidney Complications in Subjects with Type 1 Diabetes

Aims

Oxidative stress is involved in the pathophysiology of diabetic nephropathy. Manganese superoxide dismutase (SOD2) catalyses the dismutation of superoxide, regulates the metabolism of reactive oxygen species in the mitochondria and is highly expressed in the kidney. Plasma concentration of advanced oxidation protein products (AOPP), a marker of oxidative stress, was found to be increased in patients with kidney disease. We investigated associations of SOD2 allelic variations, plasma SOD activity and AOPP concentration with diabetic nephropathy in type 1 diabetic subjects.

Methods

Eight SNPs in the SOD2 region were analysed in 1285 Caucasian subjects with type 1 diabetes from the SURGENE prospective study (n = 340; 10-year follow-up), GENESIS (n = 501) and GENEDIAB (n = 444) cross-sectional studies. Baseline plasma concentration of AOPP and SOD activity were measured in GENEDIAB participants. Hazard ratio (HR) and odds ratio (OR) were determined for incidence and prevalence of nephropathy. Analyses were adjusted or stratified by retinopathy stages.

Results

In the SURGENE cohort, the T-allele of rs4880 (V16A) was associated with the incidence of renal events (new cases, or the progression to a more severe stage of nephropathy; HR 1.99, 95% CI 1.24–3.12, p = 0.004) and with the decline in estimated glomerular filtration rate (eGFR) during follow-up. Similar associations were observed for rs2758329 and rs8031. Associations were replicated in GENESIS/GENEDIAB cohorts, in the subset of participants without proliferative retinopathy, and were confirmed by haplotype analyses. Risk allele and haplotype were also associated with higher plasma AOPP concentration and lower SOD activity.

Conclusions

SOD2 allelic variations were associated with the incidence and the progression of diabetic nephropathy, with a faster decline in eGFR and with plasma AOPP concentration and SOD activity in subjects with type 1 diabetes. These results are consistent with a role for SOD2 in the protection against oxidative stress and kidney disease in type 1 diabetes.     

Payments for Environmental Services in a Policymix: Spatial and Temporal Articulation in Mexico

Government based Payments for Ecosystem Services (PES) have been criticized for not maximizing environmental effectiveness through appropriate targeting, while instead prioritizing social side-objectives. In Mexico, existing literature on how the Payments for Ecosystem Services-Hydrological program (PSA-H) has targeted deforestation and forest degradation shows that both the process of identifying the eligible areas and the choice of the selection criteria for enrolling forest parcels have been under the influence of competing agendas. In the present paper we study the influence of the PSA-H multi-level governance on the environmental effectiveness of the program–the degree to which forest at high risk of deforestation is enrolled- building from a “policyscape” framework. In particular, we combine governance analysis with two distinct applications of the policyscape framework: First, at national level we assess the functional overlap between the PSA-H and other environmental and rural programs with regard to the risk of deforestation. Second, at regional level in the states of Chiapas and Yucatan, we describe the changing policy agenda and the role of technical intermediaries in defining the temporal spatialization of the PSA-H eligible and enrolled areas with regard to key socio-economic criteria. We find that, although at national level the PSA-H program has been described as coping with both social and environmental indicators thanks to successful adaptive management, our analysis show that PSA-H is mainly found in communities where deforestation risk is low and in combination with other environmental programs (protected areas and forest management programs). Such inertia is reinforced at regional level as a result of the eligible areas’ characteristics and the behaviour of technical intermediaries, which seek to minimise transaction costs and sources of uncertainty. Our project-specific analysis shows the importance of integrating the governance of a program in the policyscape framework as a way to better systematize complex interactions at different spatial and institutional scales between policies and landscape characteristics.     

Photonic Switching Techniques and Architecture for Next Generation Optical Networks

Currently, the growth in capacity demand is still increasing by the emergence of a large number of applications that dramatically increase bandwidth demand and generate a large number of resource requirements in the network. Since the emerging applications require increased bandwidth capacity, the vision of using optical technology in the communication channel, signal processing, and switching fabric is very promising. This article presents an overview of optical switching techniques currently under research investigations. It introduces enabling technologies that have been recently researched and then presents some newly proposed architectures. It describes the SKYLIGHT switch that has been recently developed by the author. The architecture design of the switch is based on a optical code division multiple access (OCDMA) technique. Performance evaluation of the switch fabric based on the analytical evaluation of the code and numerical simulations of the optical components used to implement the system is presented.     

Conditional visuo-motor learning in primates: a key role for the basal ganglia

Sensory guidance of behavior often involves standard visuo-motor mapping of body movements onto objects and spatial locations. For example, looking at and reaching to grasp a glass of wine requires the mapping of the eyes and hand to the location of the glass in space, as well as the formation of a hand configuration appropriate to the shape of the glass. But our brain is far more than just a standard sensorimotor mapping machine. Through evolution, the brain of advanced mammals, in particular human and non-human primates, has acquired a formidable capacity to construct non-standard, arbitrary mapping using associations between external events and behavioral responses that bear no direct relationship. For example, we have all learned to stop at a red traffic light and to go at a green one, or to wait for a specific tone before dialing a phone number and to hang up when hearing a busy signal. These arbitrary associations are acquired through experience, thereby providing primates with a rich and flexible sensorimotor repertoire. Understanding how they are learned, and how they are recalled and used when the context requires them, has been one of the challenging issues for cognitive neuroscience. Valuable insights have been gained over the last two decades through the convergence of multiple complementary approaches. Human neuropsychology and experimental lesions in monkeys have identified a network of brain structures important for conditional sensorimotor associations, whereas imaging studies in healthy human subjects and electrophysiological recordings in awake monkeys have sought to identify the different functional processes underlying the overall function. The present review focuses on the contribution of a network linking the prefrontal cortex, basal ganglia, and dorsal premotor cortex, with special emphasis on results from recording experiments in monkeys. We will first review data pointing to a specific contribution of each component of the network to the performance of well-learned arbitrary visuo-motor associations, as well as data suggesting how novel associations are formed. Then we will propose a model positing that each component of the fronto-striatal network makes a specific contribution to the formation and/or execution of sensorimotor associations. In this model, the basal ganglia are thought to play a key role in linking the sensory, motor, and reward information necessary for arbitrary mapping.     

Les ostracodes du Néogène supérieur du littoral nord-ouest marocain entre Tanger et Asilah

Ostracodes populations have been studied in 19 samples from the upper Neogene of the Atlantic coast of NW of Morocco, between Tangier and Asilah. One hundred and two species belonging to 53 genera have been indentified. Analysis of the species assemblages allowed to reconstruct the palaeoenvironmental evolution of these deposits. This begins with the transgression of the upper Tortonian which corresponds to a relatively deep circalittoral environment. The series continues by deposits showing a general regressive character, punctuated by few transgressives pulses. Shallowing starts at the end of the upper Tortonian with the deposition of calcarenites in massive banks, in an infralittoral exposed environment. This facies pass towards the top to a detrital facies, assigned to the Messinian and deposited under high energy conditions in a shallow-marine environment. The lower Pliocene transgression shows a more generalized character. The maximum deepening corresponds to the grey clay facies deposited in the external infralittoral environment, relatively protected and rich in phytal biotopes. The more recent deposits are shallower, from coastal environments, and show a more limited extension.