Effects of heavy resistance training on maximal and explosive force production, endurance and serum hormones in adolescent handball players

To determine the effects of 6-weeks of heavy-resistance training on physical fitness and serum hormone status in adolescents (range 14-16 years old) 19 male handball players were divided into two different groups: a handball training group (NST, n = 10), and a handball and heavy-resistance strength training group (ST, n = 9). A third group of 4 handball goalkeepers of similar age served as a control group (C, n = 4). After the 6-week training period, the ST group showed an improvement in maximal dynamic strength of the leg extensors (12.2%; P < 0.01) and the upper extremity muscles (23%; P < 0.01), while no changes were observed in the NST and C groups. Similar differences were observed in the maximal isometric unilateral leg extension forces. The height of the vertical jump increased in the NST group from 29.5 (SD 4) cm to 31.4 (SD 5) cm (P < 0.05) while no changes were observed in the ST and C groups. A significant increase was observed in the ST group in the velocity of the throwing test [from 71.7 (SD 7) km x h(-1) to 74.0 (SD 7) km x h(-1); P < 0.001] during the 6-week period while no changes were observed in the NST and C groups. During a submaximal endurance test running at 11 km x h(-1), a significant decrease in blood lactate concentration occurred in the NST group [from 3.3 (SD 0.9) mmol x l(-1) to 2.4 (SD 0.8) mmol x l(-1); P < 0.01] during the experiment, while no change was observed in the ST or C groups. Finally, a significant increase (P < 0.01) was noted in the testosterone:cortisol ratio in the C group, while the increase in the NST group approached statistical significance (P < 0.08) and no changes in this ratio occurred in the ST group. The present findings suggested that the addition of 6-weeks of heavy resistance training to the handball training resulted in gains in maximal strength and throwing velocity but it compromised gains in leg explosive force production and endurance running. The tendency for a compromised testosterone:cortisol ratio observed in the ST group could have been associated with a state of overreaching or overtraining.     

Exposure to road traffic noise and cognitive development in schoolchildren in Barcelona,Spain: A population-based cohort study

BackgroundRoad traffic noise is a prevalent and known health hazard. However, little is known yet about its effect on children’s cognition. We aimed to study the association between exposure to road traffic noise and the development of working memory and attention in primary school children, considering school-outdoor and school-indoor annual average noise levels and noise fluctuation characteristics, as well as home-outdoor noise exposure.Methods and findingsWe followed up a population-based sample of 2,680 children aged 7 to 10 years from 38 schools in Barcelona (Catalonia, Spain) between January 2012 to March 2013. Children underwent computerised cognitive tests 4 times (n = 10,112), for working memory (2-back task, detectability), complex working memory (3-back task, detectability), and inattentiveness (Attention Network Task, hit reaction time standard error, in milliseconds). Road traffic noise was measured indoors and outdoors at schools, at the start of the school year, using standard protocols to obtain A-weighted equivalent sound pressure levels, i.e., annual average levels scaled to human hearing, for the daytime (daytime LAeq, in dB). We also derived fluctuation indicators out of the measurements (noise intermittency ratio, %; and number of noise events) and obtained individual estimated indoor noise levels (LAeq) correcting for classroom orientation and classroom change between years. Home-outdoor noise exposure at home (Lden, i.e., EU indicator for the 24-hour annual average levels) was estimated using Barcelona’s noise map for year 2012, according to the European Noise Directive (2002). We used linear mixed models to evaluate the association between exposure to noise and cognitive development adjusting for age, sex, maternal education, socioeconomical vulnerability index at home, indoor or outdoor traffic-related air pollution (TRAP) for corresponding school models or outdoor nitrogen dioxide (NO₂) for home models. Child and school were included as nested random effects.The median age (percentile 25, percentile 75) of children in visit 1 was 8.5 (7.8; 9.3) years, 49.9% were girls, and 50% of the schools were public. School-outdoor exposure to road traffic noise was associated with a slower development in working memory (2-back and 3-back) and greater inattentiveness over 1 year in children, both for the average noise level (e.g., ‒4.83 points [95% CI: ‒7.21, ‒2.45], p-value < 0.001, in 2-back detectability per 5 dB in street levels) and noise fluctuation (e.g., ‒4.38 [‒7.08, ‒1.67], p-value = 0.002, per 50 noise events at street level). Individual exposure to the road traffic average noise level in classrooms was only associated with inattentiveness (2.49 ms [0, 4.81], p-value = 0.050, per 5 dB), whereas indoor noise fluctuation was consistently associated with all outcomes. Home-outdoor noise exposure was not associated with the outcomes. Study limitations include a potential lack of generalizability (58% of mothers with university degree in our study versus 50% in the region) and the lack of past noise exposure assessment.ConclusionsWe observed that exposure to road traffic noise at school, but not at home, was associated with slower development of working memory, complex working memory, and attention in schoolchildren over 1 year. Associations with noise fluctuation indicators were more evident than with average noise levels in classrooms.

In a cohort study, Maria Foraster and colleagues study associations between exposure to road traffic noise at schools, and trajectories of working memory and inattentiveness among schoolchildren aged 7 to 10 years in Barcelona, Spain.     

The Cell Cycle Ontology: an application ontology for the representation and integrated analysis of the cell cycle process

The Cell Cycle Ontology ( is an application ontology that automatically captures and integrates detailed knowledge on the cell cycle process. Cell Cycle Ontology is enabled by semantic web technologies, and is accessible via the web for browsing, visualizing, advanced querying, and computational reasoning. Cell Cycle Ontology facilitates a detailed analysis of cell cycle-related molecular network components. Through querying and automated reasoning, it may provide new hypotheses to help steer a systems biology approach to biological network building.     

PIGMENT SUITES AND TAXONOMIC GROUPS IN PRASINOPHYCEAE1

Pigment analysis performed on 30 Prasinophyceae strains revealed two main groups: the prasinoxanthin‐containing and prasinoxanthin‐less Prasinophyceae. Prasinoxanthin‐containing Prasinophyceae comprised the orders Mamiellales, Pseudoscourfieldiales (Pycnococcaceae), and Prasinococcales. For this group, classification with pigment composition showed a good agreement with molecular phylogeny. Mamiellales, except Crustomastix stigmatica, accumulated uriolide, micromonal, dihydrolutein, and the pigment Unidentified M1 as characteristic pigments. Prasinococcales and Pseudoscourfieldiales (Pycnococcaceae) lacked micromonal and Unidentified M1. In addition, Pseudoscourfieldiales (Pycnococcaceae) lacked uriolide. A chl c₃‐like pigment was present in prasinoxanthin‐containing strains isolated from the deep sea. Common green algae pigments, a loroxanthin derivative, and siphonaxanthin plus derivatives were found in the prasinoxanthin‐less Prasinophyceae, which included strains from Pyramimonadales, Pseudoscourfieldiales (Nephroselmidiaceae), Chlorodendrales, and a new order. Although some associations could be observed, the correspondence between pigments and molecular taxonomy was less clear for this group.     

The effect of dynamic light regimes on Chlorella

The patterns of diurnal variations in pigmentation and optical cross-section were compared for two cyclostat cultures of Chlorella pyrenoidosa, where the dynamics of the photoperiod differed. Populations were light-limited, nutrient rich and growing on an 8:16 light-dark (LD) cycle. One light regime was an 8 h sine function of the light period (sinusoidal culture), while the second had an 1 h sine function super-imposed on the 8 hour sine function (oscillating sinusoidal culture). Hourly samples were taken throughout a 12 h period including the light period. Determinations were made of chlorophyll (Chl) a and b abundance, in vivo absorption spectra, cell number and volume and used to derive both cell-specific (cell) and optical chlorophyll specific (chl) cross sections, as well as the absorption efficiency, Q, of the cells. The results indicate that C. pyrenoidosa is capable of adapting to dynamics in light intensity within an 8 h photoperiod. The sinusoidal culture showed a constant decrease in the Chl a/b ratio of 28% while the total Chl content per cell increased slightly and chl and Q remained constant, suggesting coordinated changes in reaction centers and light harvesting complexes. Over the oscillating photoperiod, however, the second culture displayed a diurnal variation in Chl a/b ratio, a 20% increase in chl and an apparent oscillation in Q. These observations suggest that an oscillating photoperiod promoted the capability of Chl molecules to collect light and that the fractional area of all Chl molecules exposed to the photon flux is inversely related to the photon flux.     

Absolute DNA values from Feulgen microspectrophotometric measurements and quantitative electron microscopy. A comparison of two species

Quantitative electron microscopy (QEM) and microspectrophotometry were used to correlate the Feulgen stain absorption values to the calculated picograms of DNA. Measurements were made in human lymphocytes, rainbow trout lymphocytes and nuclei of trout erythrocytes. The median dry weight of the nucleus, as determined by QEM, was 35.9 pg for a human lymphocyte and 30.5 pg for a trout lymphocyte. Using Salzman's value of 20% DNA per chromosome (i.e., chromatin), a human lymphocyte nucleus thus contains 7.18 pg of DNA and a trout lymphocyte nucleus 6.1 pg of DNA. The mean Feulgen absorption value of the nucleus, given in arbitrary units (AU), was 14.5 for a human lymphocyte, 12.7 for a trout lymphocyte and 12.0 for a trout erythrocyte. From these values, it was derived that each picogram of DNA of a human lymphocyte nucleus is represented by 2.02 arbitrary Feulgen units while the values for trout nuclei were 2.08 AU and 1.97 AU. On the average, we find that each picogram of DNA is represented by two arbitrary Feulgen units in our microspectrophotometric measurements.     

The prevalence of non-indigenous species in southern California embayments and their effects on benthic macroinvertebrate communities

The prevalence of non-indigenous species (NIS) in southern California embayments was assessed from 123 Van Veen grab samples collected in nine bays and harbors during the summer of 1998. NIS occurred in all but two samples. They accounted for only 4.3% of the 633 taxa but contributed 27.5% of the abundance. There was no significant difference in the proportion of NIS abundance among ports harboring large vessels, small boat marinas, and areas where boats were not moored. Three species accounted for 92% of the NIS abundance: a spionid polychaete worm Pseudopolydora paucibranchiata, a mytilid bivalve Musculista senhousia, and a semelid bivalve Theora ubrica. The NIS did not appear to have a negative impact at the overall community level since NIS abundance was positively correlated with the abundance and richness of other species. This may be due to biogenic structures built by P. paucibranchiata and M. senhousia that enhance the abundances of other macrofauna.     

The role of tRNA as a molecular spring in decoding, accommodation, and peptidyl transfer

Translation is the process by which the genetic information contained in mRNA is used to link amino acids in a predetermined sequential order into a polypeptide chain, which then folds into a protein. Transfer RNAs (tRNAs) are the adapter molecules designed to provide the "lookup" from codons to amino acids. Cryo-EM has provided evidence that the ribosome, as a molecular machine, undergoes many structural changes during translation. Recent findings show that the tRNA structure itself undergoes large conformational changes as well, and that the decoding process must be seen as a complex dynamic interplay between tRNA and the ribosome.     

Investigating the genetic diversity and differentiation patterns in the <Emphasis Type="Italic">Penstemon scariosus</Emphasis> species complex under different sample sizes using AFLPs and SSRs

Habitat fragmentation due to anthropogenic activities is the major cause of biodiversity loss. Endemic and narrowly distributed species are the most susceptible to habitat degradation. Penstemon scariosus is one of many species whose natural habitat is vulnerable to industrialization. All varieties of P. scariosus (P. scariosus var. albifluvis, P. scariosus var. cyanomontanus, P. scariosus var. garrettii, P. scariosus var. scariosus) have small distribution ranges, but only P. scariosus var. albifluvis is being considered for listing under the Endangered Species Act. We used eight microsatellites or simple sequence repeats (SSRs) loci and two amplified fragment length polymorphism (AFLP) primer combinations to investigate the population genetic structure and diversity of P. scariosus varieties. Moreover, we compared the utility of the two marker systems in conservation genetics and estimated an appropriate sample size in population genetic studies. Genetic differentiation among populations based on F_st ranged from low to moderate (F_st?=?0.056–0.157) and from moderate to high when estimated with D_es (D_es?=?0.15–0.32). Also, AMOVA analysis shows that most of the genetic variation is within populations. Inbreeding coefficients (F_is) were high in all varieties (0.20–0.56). The Bayesian analysis, STRUCTURE, identified three clusters from SSR data and four clusters from AFLPs. Clusters were not consistent between marker systems and did not represent the current taxonomy. MEMGENE revealed that a high proportion of the genetic variation is due to geographic distance (R²?=?0.38, P?=?0.001). Comparing the genetic measurements from AFLPs and SSRs, we found that AFLP results were more accurate than SSR results across sample size when populations were larger than 25 individuals. As sample size decreases, the estimates become less stable in both AFLP and SSR datasets. Finally, this study provides insight into the population genetic structure of these varieties, which could be used in conservation efforts.     

Factors controlling seasonal variability of benthic ammonium release and oxygen uptake in Alfacs Bay (Ebro Delta,NW Mediterranean)

The seasonal variability of sediment–water ammonium flux andoxygen uptake was studied in an estuarine bay (Alfacs Bay, Ebro Delta, NWMediterranean) influenced by temporal freshwater discharges. Three stationswith different organic loading were sampled. The relationships of benthicfluxes to bottom water (temperature, dissolved oxygen, ammonium, nitrateplus nitrite) and to sediment (porosity, chlorophyll a derivative pigments,organic carbon and nitrogen) variables were examined. Oxygen uptake rangedfrom 0.3 to 2.5 mmol m^–2 h^–1 and ammoniumrelease ranged from 6 to 230 µmol m^–2 h^–1.The lowest value was recorded at the station furthest from the freshwaterinputs, and the highest was at the littoral station nearest the freshwaterdischarge channels (for oxygen uptake) and at the deep station at the saltwedge front (for ammonium flux). Water temperature and the concentration ofchlorophyll a derivative pigments on the surface sediment were revealed asthe main variables to be taken into account to explain the variabilityfound. Changes in fluxes reflecting temperature changes were found at thestation furthest from the freshwater inputs, while at the other, fluxvariability was found to be related to the cycle of functioning offreshwater discharge channels. The different patterns of variability arediscussed in relation to the dynamics of the estuary and to the mainfeatures of benthic nitrogen cycling.