Acute effect of upper-body vibration on performance in master swimmers

The purpose of the study was to evaluate the effects of regular warm-up, and upper-body vibration (UBV), or UBV+ short warm-up on swimming performance in Masters Swimmers. Six women and 4 men, mean age 35 ± 9 years, active master swimmers volunteered to participate in the study. Participants were assigned to complete 1 of 3 warm-up types: regular, UBV-only, or UBV + short, rest for 3 minutes, and then completed a 50-yd (45.7 m) freestyle maximal performance time trial. The UBV treatment consisted of 5 minutes of upper-body vibration with a frequency of 22 Hz. Rating of perceived exertion (RPE) and heart rate (HR) were measured post warm-up and post 50-yd time trial. No significant mean differences (p = 0.56) were found among regular, UBV-only, or UBV + short warm-ups for 50-yd freestyle time (29.1 ± 3.36, 28.9 ± 3.39, and 29.1 ± 3.55 seconds, respectively). Individual data indicated that 40% (4/10) of the swimmers swam their fastest with UBV-only and 20% (2/10) with UBV + short warm-up compared to 40% (4/10) with regular warm-up. The RPE pre and post warm-ups did not differ significantly (p = 0.059 and p = 0.216, respectively). A significantly higher (p = 0.023) HR was observed after regular warm-up compared to UBV + short warm-up. Furthermore, HR post 50-yd after regular warm-up was significantly higher compared to UBV-only (p = 0.005) and UBV + short warm-up (p = 0.013). The findings of the present study indicate that UBV and UBV + short warm-up may be considered as addition or an alternative warm-up strategy to regular swimming warm-up, producing reduced cardio stress and perceived effort.     

Deconstructing the concept of Subneolithic farming in the southeastern Baltic

The paper presents a critical review of the zooarchaeological, macrobotanical, palynological and archaeological data from Lithuania and their previous interpretations, which formerly served as the basis for the concept of development of pre-Neolithic or Subneolithic low intensity farming and/or livestock breeding in the eastern Baltic region. Moreover, it presents the first direct AMS dates from the crop remains and domestic animal bones discovered in Lithuanian Subneolithic and Neolithic settlements. An investigation proved that most of, or possibly all, the early farming “evidence” came from the wrong identification of the plant and animal species and incorrect dating of crop remains and domestic animal bones. The errors of dating were caused by the fresh water reservoir effect being ignored when dating the bulk lacustrine sediment samples, by the failure to evaluate the impact of the palimpsest and bioturbation phenomena on the formation of an archaeological layer, and by insufficient attention to stratigraphy and spatial documentation of the finds during very extensive archaeological excavations in the second half of the 20th century. To date, no credible evidence is available in Lithuania that domestic animals had been kept and crops grown before the Neolithic Globular Amphora and Corded Ware cultures in 3200/2700 cal bc. However, this does not mean such evidence may not appear in the future, provided direct AMS dating of animal and crop residues from Subneolithic contexts continues, and systematic macrobotanical studies finally start not only in the lake settlement and fishing sites, but also in higher altitude areas.     

Considerations for Obesity,Vitamin D,and Physical Activity Amid the COVID‐19 Pandemic

As the biomedical community races to disentangle the unknowns associated with severe acute respiratory syndrome coronavirus 2, the virus responsible for causing coronavirus disease, the link between diminished immune function and individuals with obesity raises important questions about the possibility for greater viral pathogenicity in this population. Increased adiposity may undermine the pulmonary microenvironment wherein viral pathogenesis and immune cell trafficking could contribute to a maladaptive cycle of local inflammation and secondary injury. A further challenge to those with obesity during the current pandemic may involve vitamin D deficiency or insufficiency. In the interest of personal and public health, we caution decision‐ and policy makers alike not to pin all hope on a proverbial “silver bullet.” Until further breakthroughs emerge, we should remember that modifiable lifestyle factors such as diet and physical activity should not be marginalized. Decades of empirical evidence support both as key factors promoting health and wellness.     

Asymmetric Excitatory Synaptic Dynamics Underlie Interaural Time Difference Processing in the Auditory System

Low-frequency sound localization depends on the neural computation of interaural time differences (ITD) and relies on neurons in the auditory brain stem that integrate synaptic inputs delivered by the ipsi- and contralateral auditory pathways that start at the two ears. The first auditory neurons that respond selectively to ITD are found in the medial superior olivary nucleus (MSO). We identified a new mechanism for ITD coding using a brain slice preparation that preserves the binaural inputs to the MSO. There was an internal latency difference for the two excitatory pathways that would, if left uncompensated, position the ITD response function too far outside the physiological range to be useful for estimating ITD. We demonstrate, and support using a biophysically based computational model, that a bilateral asymmetry in excitatory post-synaptic potential (EPSP) slopes provides a robust compensatory delay mechanism due to differential activation of low threshold potassium conductance on these inputs and permits MSO neurons to encode physiological ITDs. We suggest, more generally, that the dependence of spike probability on rate of depolarization, as in these auditory neurons, provides a mechanism for temporal order discrimination between EPSPs.