824 research outputs found
gDefrag: A graph-based tool to help defragmenting landscapes divided by linear infrastructures
Habitat fragmentation is a major biodiversity threat. Linear infrastructures (e.g. roads) hamper the movement of
individuals and cause non-natural mortality. Roadkill hotspots have been used to define priority areas for road
effect mitigation, but data availability and reliability is an issue, particularly on wide spatial scales. Additionally,
mitigating the whole infrastructure network is unfeasible. Expedite methods are required to address such
challenges. We present the gDefrag package, a graph-based approach that builds on habitat value and accessibility
after simplifying the landscape as a graph. Its advantages include not requiring roadkill or movement data,
and providing effective methods to deliver reliable information, allowing landscape managers to address
landscape fragmentation overall. gDefrag prioritizes roads which should be targeted first to defragment the
landscape. The software includes a user-friendly manual and currently implements four prioritization criteria:
habitat quality, maximum number of inter-habitat paths, overall landscape connectivity, and simultaneously
larger and higher-quality habitats
Kinematical and neuromuscular assessment of the rowing exercise in the upright position with barbell to improve muscle strength and muscle endurance in group fitness classes
The aim was to assess the interaction between kinematics and
neuromuscular responses of subjects performing the rowing
exercise with barbell in group fitness classes with different
external loads and cadences. Fifteen male subjects performed
nine sets of nine repetitions of the selected exercise. Sets were
composed by a pair wise combination of different external
loads (5, 10 and 20 [kg]) and cadences (1, 2 and 4 musical
beats) in a randomized order. Kinematical data was collected
with an electrogoniometer and it was assessed the: (i) absolute
duration of each exercise repetition; (ii) minimum relative
angle between the arm and forearm during the flexion action.
Neuromuscular data was collected with superficial
electromyography and it was computed the EMG amplitude
(aEMG), the EMG room mean square (RMS) and the
activation time of five muscles from the arm and trunk.
Increasing cadence decreased the absolute duration of the
exercise cycle. There was no significant interaction between
the joint angle and the external load nor the cadence. Increases
in the external load and in the cadence imposed a RMS
increase as well. It was also verified a significant interaction
among the aEMG and the external load in the four muscle
groups
Kinematical and neuromuscular assessment of the rowing exercise in the upright position with barbell to improve muscle strength and muscle endurance in group fitness classes
The aim was to assess the interaction between kinematics and
neuromuscular responses of subjects performing the rowing
exercise with barbell in group fitness classes with different
external loads and cadences. Fifteen male subjects performed
nine sets of nine repetitions of the selected exercise. Sets were
composed by a pair wise combination of different external
loads (5, 10 and 20 [kg]) and cadences (1, 2 and 4 musical
beats) in a randomized order. Kinematical data was collected
with an electrogoniometer and it was assessed the: (i) absolute
duration of each exercise repetition; (ii) minimum relative
angle between the arm and forearm during the flexion action.
Neuromuscular data was collected with superficial
electromyography and it was computed the EMG amplitude
(aEMG), the EMG room mean square (RMS) and the
activation time of five muscles from the arm and trunk.
Increasing cadence decreased the absolute duration of the
exercise cycle. There was no significant interaction between
the joint angle and the external load nor the cadence. Increases
in the external load and in the cadence imposed a RMS
increase as well. It was also verified a significant interaction
among the aEMG and the external load in the four muscle
groups
Comparação electromiográfica do passe e do remate em Futsal
Foi objectivo deste trabalho comparar a actividade neuromuscular do membro
inferior na execução do remate e do passe com o dorso do pé no Futsal. Estudaram-se 5 sujeitos
do sexo masculino e federados com idades compreendidas entre os 20 e os 26 anos. Foram
analisadas duas condições de execução: o passe e o remate. O passe foi efectuado para um
jogador colocado à sua frente e a seis metros de distância. O remate foi efectuado a uma
distância de seis metros com oposição de um guarda-redes. Os dados electromiográficos foram
recolhidos através de eléctrodos bipolares pré-amplificados colocados no Vasto interno, Vasto
externo, Gastrocnémio medial e Tibial anterior com uma frequência de aquisição de 1 kHz. O
sinal foi processado digitalmente, a fim de se obter o valor quadrático médio (RMS). A RMS foi
normalizada individualmente com base no valor máximo dentro de uma determinada condição
de exercitação. Um electrogoniómetro foi colocado entre a perna e a coxa para determinação
dos parâmetros cinemáticos. A frequência de aquisição foi de 1 kHz e os dados estavam
sincronizados com o sinal electromiográfico. Foram avaliados o ângulo relativo mínimo entre a
perna e a coxa, assim como, o valor máximo da velocidade angular entre a perna e coxa. A
velocidade foi significativamente superior e o ângulo significativamente inferior no remate do
que no passe. A actividade neuromuscular foi significativamente superior no remate do que no
passe em todos os grupos musculares estudados
Preliminary attempt to develop a path-flow analysis model for swimming performance in children
The aim of this research was to develop a path-flow analysis model from age-group swimmer’s performance
based on biomechanical and energetic parameters. Twenty two young male age-group swimmers with several competitive
levels volunteered to serve as subjects. It was assessed swim velocity, stroke length, stroke frequency, stroke index,
propulsive efficiency, critical velocity and 200 m freestyle event performance. To verify the quality of the model, root
mean square residuals (RMSR) was computed. The confirmatory model explained 54% of swimming performance.
RMSR was 0.064. As a conclusion, the model based in biomechanical and energetic variables, according to the relationships
suggested is appropriated to explain performance in age-group swimmers
Preliminary attempt to develop a path-flow analysis model for swimming performance in children
The goal of competitive swimming is to travel the event
distance as fast as possible. The identification of the parameters
that predict swimming performances is one of
the main aims of the swimming “science” community.
Indeed, it is consensual that biomechanical and energetic
variables are determinant for performance in this
sport. Several research groups dedicate their attention
to the relationships establish between biomechanical
and energetic variables on adult swimmers, with special
emphasis on elite adult swimmers
Body composition comparison between gender in institutionalized elderly
Este estudo teve como objetivo averiguar sobre a existência de diferenças entre
sexos, da composição corporal de idosos institucionalizados.The purpose of this Study was to compare the body composition differences between gender in institutionalized elderly.info:eu-repo/semantics/publishedVersio
Physical fitness in youth basketball players in pre and post season under a strength program effect
Basketball it’s an acyclic modality characterized by an intermittent effort, direction changes and a hypersolicitation of upper and lower limbs. Thus, it depends of a physical excellence to individual or collective performance improvement. The aim of this study was to evaluate the physical fitness in youth basketball players in pre-season and post-season under a strength program.info:eu-repo/semantics/publishedVersio
Do the strength levels predict the motor coordination in young basketball players?
O objetivo deste estudo foi averiguar sobre a existência de relação entre os níveis
de força e a coordenação motora em basquetebolistas pertencentes ao escalão de sub-18.The aim of this study was to analyse the relation between the strength levels and
motor coordination in young basketball players.info:eu-repo/semantics/publishedVersio
Strength training effects on pre-pubertal boys
There are some incongruent results in strength training effects on pre-pubertal boys. Vrijens (1979) shows that
prepubescent boys were incapable of increasing strength or muscle cross-sectional area of the extremities
following a program of resistance training. Various recent studies have shown that prepubescent boys are
capable of making strength gains following an appropriate training program (Ramsay, et al., 1990). However
the mechanisms underling strength gains following resistance strength training programs is not well clarified.
There is some evidence that the gains are associated with neuromuscular adaptations with no muscle
hypertrophy, but this later issue is an unresolved question. The purpose of this study is to investigate the
resistance strength training effects on pre-pubertal boys, that is, the enhancement of strength and its correlates,
namely the changes in muscular mass and neuro-muscular activity.
The sample comprises 11 boys, aged 9,52±0,55 years, divided in an experimental group (EG) (n=6) and in a
control group (CG) (n=5). All boys were in stage 1 according to Tanner’s scale of sexual maturation. The
sample was evaluated in serum testosterone level, and all boys were above the level of 50 ng*dl-1,wich is
considered to be within the normal range for pre-pubertal boys (Winter, 1978). The EG group was submitted
to a training program with callisthenic exercises three sessions a week for 10 weeks. In each session the training
comprised the following exercises: push-ups, modified pull-ups and the 2 exercises with elastics (elbows
flexion and extension and extension of the arms above the head) until exhaustion. The training volume was
being gradually adapted from 3 series between the 1st and 3rd week to 4 series between the 4th and 6th week and
to 5 series between the 7th and 10th week. The sample was evaluated in pre and in post-test in maximal isometric
voluntary force (MIVF), muscle mass, and in EMG. The MIVF was evaluated during the Shoulder Press (SP),
the Arm Curl (AC) and the Triceps Press (TP). The MIVF was measured using a dynamometer (TST 121C from
Biopac Systems Inc.). We also evaluated the maximal number of push ups (PU) and modified pull ups (MPU),
and the distance in over arm throw with roller-skate hockey ball (THW). The EMG signals were acquired
during the MIVF exercises (SP, AC, and TP). During the AC exercise, one surface electrode (TSD 150A from
Biopac Systems Inc.) was attached to each biceps. During the SP and TP, one surface electrode was attached to
the vastus medialis of each of the triceps. A ground electrode was attached to the elbow. The EMG signals
were amplified through a differential amplifier with 2MW, a gain of 1000 and a bandwidth between 15-450Hz.
The EMG signals were full-wave rectified and smoothed, allowing to determinate the integral (iEMG) and the
amplitude (aEMG) of the EMG signal. The iEMG was standardised according to the duration of the contraction.
Both aEMG and iEMG results of both arm in each exercise were summed. The muscle thickness of the biceps
and of the triceps of both arms were measured by B-mode ultrasonography, using real-time electronic scanner
with 7.5MHz scanning head (Ecocamera Aloca SSD-500). The data were analysed using the ANOVA repeated
measures (group x training program).
In THW the results indicate a significant interaction effect (F(1, 9) = 7,814; p = 0,021), with an increase of 22%
in EG and a slight decrease in CG. In PU the results indicate a significant main effect (F(1, 9) = 15,537; p =
0,003), and a significant interaction effect (F(1, 9) = 16,61; p = 0,003), with an increase of 150% in EG and no
changes in CG. In MPU the results indicate a significant main effect (F(1, ) = 8,006; p = 0,019), and a significant
interaction effect (F(1, 9) = 17,667; p = 0,002), with an increase of 120,9% in EG and a slight decrease in CG.
There were no significant changes in the three tests of MIVF and in iEMG, aEMG, or in the muscle mass.
These results indicate that pre-pubertal boys could increase the resistance strength after a training program
that include callisthenic exercises, but seems that the isometric strength could not be enhanced. The increase
in resistance strength is not accompanied by an increase in muscle mass. Although in this study we only
evaluated the neuro-muscular factors in MIVF, it seems that the factors underlying the enhanced strength
might be neuro-muscular.info:eu-repo/semantics/publishedVersio
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