Expression of Axolotl DAZL RNA, a Marker of Germ Plasm: Widespread Maternal RNA and Onset of Expression in Germ Cells Approaching the Gonad

AbstractHow germ cell specification occurs remains a fundamental question in embryogenesis. The embryos of several model organisms contain germ cell determinants (germ plasm) that segregate to germ cell precursors. In other animals, including mice, germ cells form in response to regulative mechanisms during development. To investigate germ cell determination in urodeles, where germ plasm has never been conclusively identified, we cloned a DAZ-like sequence from axolotls, Axdazl. Axdazl is homologous to Xdazl, a component of Xenopus germ plasm found in the vegetal pole of oocytes and eggs. Axdazl RNA is not localized in axolotl oocytes, and, furthermore, these oocytes do not contain the mitochondrial cloud that localizes Xdazl and other germ plasm components in Xenopus. Maternal Axdazl RNA is inherited in the animal cap and equatorial region of early embryos. At gastrula, neurula, and tailbud stages, Axdazl RNA is widely distributed. Axdazl first shows cell-specific expression in primordial germ cells (PGCs) approaching the gonad at stage 40, when nuage (germ plasm) appears in PGCs. These results suggest that, in axolotls, germ plasm components are insufficient to specify germ cells

Geometric Entropy for Lead vs Top-Rope Rock Climbing

International Journal of Exercise Science 9(2): 168-174, 2016. The complexity of movement of a rock climber’s center of mass during an ascent has been described as geometric entropy (GE). It has been proposed that lower geometric entropy could represent more fluid and economical movement during climbing. The purpose of the present study was to measure GE during rock climbing ascents under a lead condition (LD), where the climber connects a safety rope to several intermediate anchors during the ascent and under a top-rope condition (TR), where the safety rope is always anchored above the climber. Six experienced rock climbers volunteered to participate in the study. Each participant ascended a route on natural rock outdoors under three conditions. The first ascent was performed in a top-rope condition as an accommodation trial. The two remaining ascents were performed as LD and top-rope (TR2) in random order. Each LD and TR2 ascent was recorded via digital video at 30 Hz. A single point at the back center of each climber’s waist harness was manually digitized from the video images at 6 Hz and interpreted as the climber’s center of mass (CM). The displacement of CM was expressed as the line of motion (LM). Geometric Entropy (GE) was calculated as GE = ln((2∙LM)/CH)), where CH was the value of the convex hull about the LM. A within subjects, repeated measures ANOVA with Bonferroni post hoc testing was utilized to test for differences among ascent conditions with significance set at P \u3c0.05. Mean (±s.d) values for LM and GE were 81.5±11.3 m vs 77.6±7.3 m and 1.021±0.133 vs 0.924±0.062 for LD and TR2 respectively. There were no significant differences for LM and GE between ascent conditions. It was concluded that LM and GE do not vary between LD and TR ascent conditions

In-class cycling to augment college student academic performance and reduce physical inactivity: Results from an RCT

Most college students sit 14 hours per week on average, excluding sedentary study time. Researchers observing workplace and elementary school settings with active workstations to combat sedentary behavior have shown enhanced cognition without distraction. Until now, incorporating active workstations in college classroom settings remained relatively unexplored. This study’s purpose was to assess academic performance using in-class stationary cycle desks during a semester-long lecture course. Twenty-one college students (19–24 years) enrolled in a lecture course volunteered and were split into traditional sit (SIT) and stationary cycle (CYC) groups randomly, matched on a calculated factor equal to a physical activity (PA) score (0–680) multiplied by grade point average (GPA; 4.0 scale). CYC pedaled a prescribed rate of perceived exertion (RPE) of less than 2 out of 10 during a 50-min lecture, 3 × week for 12 weeks. CYC averaged 42 min, 7.9 miles, and 1.7 RPE during class throughout the semester. No significant differences (p \u3e 0.05) were observed between CYC and SIT on in-class test scores or overall course grades. Although statistically insignificant, CYC had higher mean test scores and overall course grades vs. SIT (i.e., B+ vs. B, respectively). Low intensity cycling during a college lecture course maintained student academic performance and possibly reduced weekly sedentary behavior time

Exercise with blood flow restriction to improve quadriceps function long after ACL reconstruction

Quadriceps atrophy and weakness can persist for years after anterior cruciate ligament reconstruction (ACLR). We evaluated the effectiveness of a home-based blood flow restriction (BFR) exercise program to increase quadriceps size and strength several years after ACLR. Nine adults with ACLR (5±2 yrs post-surgery, ≤90% symmetry in quadriceps size and strength) and nine uninjured controls volunteered. ACLR participants exercised at home for 25 min, 5×/wk for 4 wks (single-leg knee extension, bodyweight half-squats, walking). Blood flow in only the involved leg was restricted using a thigh cuff inflated to 50% of limb occlusion pressure. Rectus femoris and vastus lateralis thickness and knee extensor strength were measured before and after training. Baseline and post-training symmetry (involved leg/uninvolved leg) indices were compared to uninjured controls. Rectus femoris and vastus lateralis thickness and knee extensor strength in the involved leg increased by 11±5%, 10±6%, and 20±14%, respectively (all P\u3c0.01). Compared to baseline, post-training knee extensor strength symmetry increased from 88±4 to 99±5% (P\u3c0.01) and did not differ from uninjured controls (99±5%, P=0.95). Implementation of BFR exercise at home was feasible, safe and effective. Results extend upon early post-operative application of BFR exercise for ACLR recovery and demonstrate that BFR can improve quadriceps function long after ACLR

In-Class Cycling to Augment College Student Academic Performance and Reduce Physical Inactivity: Results from an RCT

Most college students sit 14 hours per week on average, excluding sedentary study time. Researchers observing workplace and elementary school settings with active workstations to combat sedentary behavior have shown enhanced cognition without distraction. Until now, incorporating active workstations in college classroom settings remained relatively unexplored. This study’s purpose was to assess academic performance using in-class stationary cycle desks during a semester-long lecture course. Twenty-one college students (19–24 years) enrolled in a lecture course volunteered and were split into traditional sit (SIT) and stationary cycle (CYC) groups randomly, matched on a calculated factor equal to a physical activity (PA) score (0–680) multiplied by grade point average (GPA; 4.0 scale). CYC pedaled a prescribed rate of perceived exertion (RPE) of less than 2 out of 10 during a 50-min lecture, 3 × week for 12 weeks. CYC averaged 42 min, 7.9 miles, and 1.7 RPE during class throughout the semester. No significant differences (p > 0.05) were observed between CYC and SIT on in-class test scores or overall course grades. Although statistically insignificant, CYC had higher mean test scores and overall course grades vs. SIT (i.e., B+ vs. B, respectively). Low intensity cycling during a college lecture course maintained student academic performance and possibly reduced weekly sedentary behavior time

Estimated Seroprevalence of SARS-CoV-2 Antibodies Among Adults in Orange County, California

ABSTRACT Background Clinic-based estimates of SARS-CoV-2 may considerably underestimate the total number of infections. Access to testing in the US has been heterogeneous and symptoms vary widely in infected persons. Public health surveillance efforts and metrics are therefore hampered by underreporting. We set out to provide a minimally biased estimate of SARS-CoV-2 seroprevalence among adults for a large and diverse county (Orange County, CA, population 3.2 million). Methods We implemented a surveillance study that minimizes response bias by recruiting adults to answer a survey without knowledge of later being offered a SARS-CoV-2 test. Several methodologies were used to retrieve a population-representative sample. Participants (n=2,979) visited one of 11 drive-thru test sites from July 10 th to August 16 th , 2020 (or received an in-home visit) to provide a finger pin-prick sample. We applied a robust SARS-CoV-2 Antigen Microarray technology, which has superior measurement validity relative to FDA-approved tests. Findings Participants include a broad age, gender, racial/ethnic, and income representation. Adjusted seroprevalence of SARS-CoV-2 infection was 11.5% (95% CI: 10.5% to 12.4%). Formal bias analyses produced similar results. Prevalence was elevated among Hispanics (vs. other non-Hispanic: prevalence ratio [PR]= 1.47, 95% CI: 1.22 to 1.78) and household income <50,000 (vs. >100,000: PR= 1.42, 95% CI: 1.14 to 1.79). Interpretation Results: from a diverse population using a highly specific and sensitive microarray indicate a SARS-CoV-2 seroprevalence of ∼12 percent. This population-based seroprevalence is seven-fold greater than that using official County statistics. In this region, SARS-CoV-2 also disproportionately affects Hispanic and low-income adults. Funding Orange County Healthcare Agenc

Estimated seroprevalence of SARS-CoV-2 antibodies among adults in Orange County, California.

Clinic-based estimates of SARS-CoV-2 may considerably underestimate the total number of infections. Access to testing in the US has been heterogeneous and symptoms vary widely in infected persons. Public health surveillance efforts and metrics are therefore hampered by underreporting. We set out to provide a minimally biased estimate of SARS-CoV-2 seroprevalence among adults for a large and diverse county (Orange County, CA, population 3.2 million). We implemented a surveillance study that minimizes response bias by recruiting adults to answer a survey without knowledge of later being offered SARS-CoV-2 test. Several methodologies were used to retrieve a population-representative sample. Participants (n = 2979) visited one of 11 drive-thru test sites from July 10th to August 16th, 2020 (or received an in-home visit) to provide a finger pin-prick sample. We applied a robust SARS-CoV-2 Antigen Microarray technology, which has superior measurement validity relative to FDA-approved tests. Participants include a broad age, gender, racial/ethnic, and income representation. Adjusted seroprevalence of SARS-CoV-2 infection was 11.5% (95% CI: 10.5-12.4%). Formal bias analyses produced similar results. Prevalence was elevated among Hispanics (vs. other non-Hispanic: prevalence ratio [PR] = 1.47, 95% CI 1.22-1.78) and household income < 50,000 (vs. > 100,000: PR = 1.42, 95% CI: 1.14 to 1.79). Results from a diverse population using a highly specific and sensitive microarray indicate a SARS-CoV-2 seroprevalence of ~ 12 percent. This population-based seroprevalence is seven-fold greater than that using official County statistics. In this region, SARS-CoV-2 also disproportionately affects Hispanic and low-income adults

Prioritization of Post-Myocardial Infarction Heart Failure Targets Using Large-Scale Plasma Proteomics and Genome-Wide Single-Cardiac Cell Transcriptomics

Scientific Sessions of the American-Heart-Association14