THE EFFECTS OF LOAD MASS ON THE KINEMATICS OF STIFF-LEGGED DEADLIFT

The purpose of this study was to investigate the effects of load mass on the kinematics of lower extremity joint movements during the stiff-legged deadlift (SLD) lift exercise. Five participants performed the SLD at 40%, 60%, and 80% of their estimated 1 repetition maximum. Measurements of the joint angle and angular velocity of the spine, hip, knee, and ankle were analyzed to understand the influence of various load masses in the SLD lifting technique. No statistical significant differences were found in the joint angles and angular velocities of the spine and lower extremity between different loads. Therefore, this study suggests that performing stiff-legged exercise up to 80% is safe to perform as long as the participants are experienced with this lifting technique

KINEMATIC ANALYSIS OF FRONT SQUAT IN RESPONSE TO LOADS

The purpose of this study was to examine the kinematics of lower extremity and spine in response to different mass loads in front squat exercise. Three experienced male varsity athletes were recruited to participate in this study, and each participant performed five trials of front squat exercise at three different loads (65%, 75%, and 85% of 1 repetition maximum). A standard two-dimensional kinematic analysis was conducted and the result showed that the participants had no significant difference on different loads in both lower extremity and spine. However, the knee joint demonstrated a strong sensitivity in response to load mass, so a strength training program may be prescribed focusing on the knee joint stability. Future research studies are warranted to examine the kinematic differences between a knee-braced front squat and a plain front squat

Abnormal Excitability of Oblique Dendrites Implicated in Early Alzheimer's: A Computational Study

The integrative properties of cortical pyramidal dendrites are essential to the neural basis of cognitive function, but the impact of amyloid beta protein (aβ) on these properties in early Alzheimer's is poorly understood. In animal models, electrophysiological studies of proximal dendrites have shown that aβ induces hyperexcitability by blocking A-type K+ currents (IA), disrupting signal integration. The present study uses a computational approach to analyze the hyperexcitability induced in distal dendrites beyond the experimental recording sites. The results show that back-propagating action potentials in the dendrites induce hyperexcitability and excessive calcium concentrations not only in the main apical trunk of pyramidal cell dendrites, but also in their oblique dendrites. Evidence is provided that these thin branches are particularly sensitive to local reductions in IA. The results suggest the hypothesis that the oblique branches may be most vulnerable to disruptions of IA by early exposure to aβ, and point the way to further experimental analysis of these actions as factors in the neural basis of the early decline of cognitive function in Alzheimer's

Evaluating machine learning techniques for archaeological lithic sourcing: a case study of flint in Britain

The original version of this Article contained errors in the legends of Figure 8 and 9. The legend of Figure 8: “Learning curve shows F1 score for train and test data against number of observations in training data.” now reads: “Box Plot of F1 Scores for each model, showing good equality of variances.

Global risk model for vector-borne transmission of Zika virus reveals the role of El Nino 2015

Zika, a mosquito-borne viral disease that emerged in South America in 2015, was declared a Public Health Emergency of International Concern by the WHO in February of 2016. We developed a climate-driven R(0) mathematical model for the transmission risk of Zika virus (ZIKV) that explicitly includes two key mosquito vector species: Aedes aegypti and Aedes albopictus. The model was parameterized and calibrated using the most up to date information from the available literature. It was then driven by observed gridded temperature and rainfall datasets for the period 1950–2015. We find that the transmission risk in South America in 2015 was the highest since 1950. This maximum is related to favoring temperature conditions that caused the simulated biting rates to be largest and mosquito mortality rates and extrinsic incubation periods to be smallest in 2015. This event followed the suspected introduction of ZIKV in Brazil in 2013. The ZIKV outbreak in Latin America has very likely been fueled by the 2015–2016 El Niño climate phenomenon affecting the region. The highest transmission risk globally is in South America and tropical countries where Ae. aegypti is abundant. Transmission risk is strongly seasonal in temperate regions where Ae. albopictus is present, with significant risk of ZIKV transmission in the southeastern states of the United States, in southern China, and to a lesser extent, over southern Europe during the boreal summer season