1,264 research outputs found
A comparison between elite swimmers and kayakers on upper body push and pull strength and power performance
The aim of the present study was to compare the load-power curve expressed at bench press (PR) and prone bench pull (PU) between elite swimmers and kayakers. Another aim was to calculate the strength and power PR/PU ratio in the same populations. Fifteen elite swimmers (SW: age = 23.8 ± 2.9 y; body mass = 82.8 ± 5.6 kg; body height = 184.1 ± 4.6 cm) and 13 elite kayakers (KA: age = 23.8 ± 2.9 y; body mass = 91.0 ± 3.5 kg; body height = 180.1 ± 5.4 cm) were assessed for PR 1RM and PU 1RM. They were then assessed for power produced at 40, 60 and 80% of 1RM in both PR and PU. The area under the load-power curve (AUC) and PR/PU ratios were calculated for both the SW and KA groups. The KA group showed significantly higher PR1RM (+18.2%; p = 0.002) and PU1RM (+25.7%; p < 0.001) compared to the SW group. Significant group differences were also detected for PUAUC (p < 0.001) and for the PR/PU power ratio (p < 0.001). No significant group differences were detected for PRAUC (p = 0.605) and for the PR/PU strength ratio (p = 0.065; 0.87 and 0.82 in SW and KA, respectively). The present findings indicate that elite KA were stronger and more powerful than elite SW in the upper body. Not consistently with other athletic populations, both KA and SW athletes were stronger and more powerful in upper body pull compared to push moves
Parent Interaction In Primetime Family Themed Television Portrayals: A Replication And Extension Of Dail And Way\u27s (1985) Content Analysis
This research is a replication and extension of Dail and Wayâs (1985) content analysis identifying parent interactions portrayed in family oriented prime time network television programs. Family structure, parent role, child rearing, and child responses were coded from five episodes each of eight different programs from 2014-2015 television season. The programs presented parent roles more often than child rearing, while mothers were found in child rearing more often than fathers. Traditional family structures were most prevalent with fewer single parent households and a new presence of same-sex parents. Mothers and fathers were still portrayed stereotypically, but childrenâs responses were more realistic and further reinforced traditional gender roles. Child responses reinforced traditional and rejected non-traditional parent interactions according to the parentsâ sex, partnership, and occupation
A Comparison between Non-Localized Post-Activation Performance Enhancements Following Resistance Exercise for the Upper and the Lower Body
The aim of the present investigation was to compare the acute non-localized post-activation performance enhancement (PAPE) of an exercise protocol involving either the upper or the lower body muscles. Twenty-four resistance trained men participated in the present study and were randomly assigned to an upper body (UB) or to a lower body (LB) group. Both groups tested for upper and lower body power (bench press throw (BPT) and countermovement jump power (CMJP) tests). Participants in the UB group were tested pre and post a high-intensity (HI) and a high-power (POW) bench press protocol while participants in the LB group performed a HI squat and a jump session (POW). A significant group Ă time interaction was found for CMJP in HI (p = 0.012). Post hoc tests revealed that CMJP was elevated in UB group only (+1.6%; p = 0.025). No other significant interactions were detected. Results of this study indicate that a non-localized PAPE on the lower body may be induced by a HI bench press protocol while a HI squat protocol may not increase upper body power. In particular, the squat protocol performed in the present study (5 sets of 1 rep) may be too demanding to produce a non-localized PAPE
Amine-Rich Carbon Dots as Novel Nano-Aminocatalytic Platforms in Organic Synthesis
The development of novel and effective metal-free catalytic systems, which can drive value-added organic transformations in environmentally benign solvents (for instance, water), is highly desirable. Moreover, these new catalysts need to be harmless, easy-to-prepare, and potentially recyclable. In this context, amine-rich carbon dots (CDs) have recently emerged as promising nano-catalytic platforms. These nitrogen-doped nanoparticles, which show dimensions smaller than 10 nm, generally consist of carbon cores that are surrounded by shells containing numerous amino groups. In recent years, organic chemists have used these surface amines to guide the design of several synthetic methodologies under mild operative conditions. This Concept highlights the recent advances in the synthesis of amine-rich carbon dots and their applications in organic catalysis, including forward-looking opportunities within this research field
Arm-stroke descriptor variability during 200-M front crawl swimming
The present study aimed to explore the variability of the arm-stroke temporal descriptors between and within laps during middle-distance swimming event using IMMUs. Eight male swimmers performed a 200-m maximum front-crawl in which the inter-lap and intra-lap variability of velocity, stroke rate, stroke-phases duration and arm-coordination index were measured through five units of IMMU. An algorithm computes the 3D coordinates of the wrist by means the IMMU orientation and the kinematic chain of upper arm biomechanical model, and it recognizes the start events of the four arm-stroke phases. Velocity and stroke rate had a mean value of 1.47 ± 0.10 m·sâ1 and 32.94 ± 4.84 cycles·minâ1, respectively, and a significant decrease along the 200-m (p < 0.001; η2 = 0.80 and 0.47). The end of each lap showed significantly lower stroke rate compared to the start and the middle segment (p < 0.05; η2 = 0.55). No other significant inter-lap and intra-lap differences were detected. The two main findings are: (i) IMMUs technology can be an effective solution to continuously monitor the temporal descriptors during the swimming trial; (ii) swimmers are able to keep stable their temporal technique descriptors in a middle-distance event, despite the decrease of velocity and stroke rate
Observation Method to Predict Meander Migration and Vertical Degradation of Rivers
Meander migration and vertical degradation of river bed are processes that have been studied for years. These two erosion controlled processes consist of the gradual change of the geometry of the river due to the flow of water eroding the soil. This erosion may cause a shift that could be a threat to existing bridges, highways, and useful lands. Different methods have been proposed to make predictions of the behavior of rivers with respect to these processes. Many of these methods are used to predict the migration rate and the final position of the bankline or centerline of a river, assuming that the erosion rate is constant for a certain time. However, most of these methods ignore one of the three general processes of meander migration and vertical degradation: geometry, flow, and soil. Therefore, there is need for a method that can accurately predict the amount of erosion that may occur in rivers.
Six different sites in Texas were selected for this project. Four of the selected rivers have meander migration problems, and two rivers have vertical degradation problems. Each river has shown erosion problems that have been a threat to the bridges, roads or farm lands. A new method, called the Observation Method, was developed to predict meander migration and vertical degradation by using geometry, water flow, and soil erodibility. Aerial photos and maps from different years were obtained to study the change of the geometry of the rivers. River hydrographs were obtained from the U.S. Geological Survey to estimate the river velocity from daily flow. Soil samples from each site were obtained for laboratory testing, using the Erosion Function Apparatus. A code was written in MATLAB and Excel to estimate the critical velocity by using a model based on the erosion function obtained from the erosion tests. It is important to know where the river was and its history to be able to predict where the river will be. The erosion of each river from the six sites was estimated using the model and predictions were made for 10 years after the last observation for each case. This method proved to be a simple and quick way to obtain results for the movement of one point of the river
Efficiency of Collisional O2 + N2 Vibrational Energy Exchange
10 pags.; 6 figs.; 5 tabs. In press.By following the scheme of the Grid Empowered Molecular
Simulator (GEMS), a new O2 + N2 intermolecular potential, built on ab initio
calculations and experimental (scattering and second virial coefficient) data, has
been coupled with an appropriate intramolecular one. On the resulting potential
energy surface detailed rate coefficients for collision induced vibrational energy
exchanges have been computed using a semiclassical method. A cross comparison
of the computed rate coefficients with the outcomes of previous semiclassical
calculations and kinetic experiments has provided a foundation for characterizing
the main features of the vibrational energy transfer processes of the title system as
well as a critical reading of the trajectory outcomes and kinetic data. On the
implemented procedures massive trajectory runs for the proper interval of initial
conditions have singled out structures of the vibrational distributions useful to
formulate scaling relationships for complex molecular simulations.The authors acknowledge financial support from the Phys4-
entry FP7/2007-2013 project (Contract 242311), ARPA
Umbria, INSTM, the EGI-Inspire project (Contract 261323),
MIUR PRIN 2008 (2008KJX4SN 003) and 2010/2011
(2010ERFKXL_002), the ESA-ESTEC contract 21790/08/
NL/HE, and the Spanish CTQ2012-37404 and FIS2013-
48275-C2-1-P projects. Computations have been supported by
the use of Grid resources and services provided by the
European Grid Infrastructure (EGI) and the Italian Grid
Infrastructure (IGI) through the COMPCHEM Virtual
Organization. Thanks are also due to the COST CMST
European Cooperative Project CHEMGRID (Action D37) EGI
Inspire.Peer reviewe
Enhanced flexibility of the O2 + N2 interaction and Its effect on collisional vibrational energy exchange
12 pĂĄgs.; 8 figs.; 1 app. This article is part of the Piergiorgio Casavecchia and Antonio Lagana Festschrift special issue.Prompted by a comparison of measured and
computed rate coefficients of Vibration-to-Vibration and
Vibration-to-Translation energy transfer in O2 + N2 nonreactive
collisions, extended semiclassical calculations of the
related cross sections were performed to rationalize the role
played by attractive and repulsive components of the
interaction on two different potential energy surfaces. By
exploiting the distributed concurrent scheme of the Grid
Empowered Molecular Simulator we extended the computational
work to quasiclassical techniques, investigated in this
way more in detail the underlying microscopic mechanisms, singled out the interaction components facilitating the energy transfer, improved the formulation of the potential, and performed additional calculations that confirmed the effectiveness of the improvement introduced.The authors acknowledge financial support from the Phys4entry
FP7/2007-2013 project (Contract No. 242311), ARPA Umbria,
INSTM, the EGI-Inspire project (Contract No. 261323),
MIUR PRIN 2008 (2008KJX4SN 003) and 2010/2011
(2010ERFKXL_002), the ESA-ESTEC Contract No. 21790/
08/NL/HE and the Spanish CTQ2012-37404 and FIS2013-
48275-C2-1-P projects. Computations have been supported by
the use of Grid resources and services provided by the European
Grid Infrastructure (EGI) and the Italian Grid Infrastructure
(IGI) through the COMPCHEM Virtual Organization. Thanks
are also due to the COST CMST European Cooperative Project
CHEMGRID (Action D37) EGI Inspire.Peer reviewe
Large-scale risk analysis in the Arno river basin (Italy)
We present the methodologies adopted and the outcomes obtained in the analysis of landslide risk in the basin of the Arno River (Central Italy) in the framework of a project sponsored by the Basin Authority of the Arno River, started in the year 2002 and completed at the beginning of 2005. A new landslide inventory of the whole area was realized, using conventional (aerialphoto interpretation and field surveys) and non-conventional methods (e.g. remote sensing techniques such as DInSAR and PS-InSAR). The great majority of the mapped mass movements are rotational slides (75%), solifluctions and other shallow slow movements (17%) and flows (5%), while soil slips, and other rapid landslides, seem less frequent everywhere within the basin. The assessment of landslide hazard in terms of probability of occurrence in a given time, based for mapped landslides on direct and indirect observations of the state of activity and recurrence time, has been extended to landslide-free areas through the application of statistical methods implemented in an artificial neural network (ANN). Unique conditions units (UCU) were defined by the map overlay of landslide preparatory factors (lithology, land cover, slope gradient, slope curvature and upslope contributing area) and afterwards used to construct a series of model vectors for the training and test of the ANN. Model validation confirms that prediction results are very good, with an average percentage of correctly recognized mass movements of about 85%. The analysis also revealed the existence of a large number of unmapped mass movements, thus contributing to the completeness of the final inventory. Temporal hazard was estimated via the translation of state of activity in recurrence time and hence probability of occurrence. The definition of position, typology and characteristics of the elements at risk has been carried out with two different methodologies, partially derived from the âPlans dâExposition au Risqueâ proposed in France: i) buildings and infrastructures were directly extracted from digital terrain cartography at the 1:10,000 scale, whilst ii) nonurban land use was identified and mapped based on an updated and improved CORINE land cover map at the 1:50,000 scale. The definition of the exposure of the elements at risk relies upon contingent valuation methods and form-based interviews. Landslide intensity, usually defined as proportional to kinetic energy, was obtained considering landslide typology as a proxy for expected velocity. In the case of the Arno River Basin the definition of intensity is influenced by the fact that the large majority of mass movements are deep-seated reactivated slides evolving into flows. Two main cases were so considered: deep-seated rotational slides and shallow flows or planar slides with virtually constant depth. In the latter case, intensity as a function of volume was set proportional to the area of the mapped phenomenon. In the former case, a simple geometric model was used to compute the volume. Intersection of hazard values with vulnerability and exposure figures, obtained by reclassification of digital vector mapping at 1:10,000 scale, lead to the definition of risk values for each terrain unit for different periods of time into the future. Numerical results indicate that in absence of mitigation measures, large economic losses must be expected due to landslide activity in the few next years. The final results of the research are now undergoing a process of integration and implementation within land planning and risk prevention policies and practices at local and national level
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