Effects of Warm Up Intensity on Factors Related to Subsequent Performance of Submaximal Exercise

Introduction: Athletes often warm up (WU) prior to exercise to improve performance. However, there are no clear directives regarding the intensity of the WU that is most effective in improving physiological responses related to enhanced aerobic performance. Methods: Nine college-aged men (age, ht, mass, 20.6 yr, 1.7 m, 84.8 kg, respectively) performed WU of varying intensities, 60% ventilatory threshold (VT), 100%VT, and 120%VT prior to performing 5 min of steady state exercise at 80%VT on a cycle ergometer. O2 deficit, RPE, steady state heart rate (HRss), and steady state VO2 (VO2ss) were measured during the exercise bout. Results: There was a significant decrease in O2 deficit as WU intensity increased ((2,9)= 9.15, p = .002, 2=0.53) with the deficit being lowest after WU at 120%VT. RPE were significantly lower after WU at 120%VT than both 60% and 100%VT (=(2,9)=6.88, p=.007, 2=0.46). However, WU intensity did not significantly affect either HRss (F(2,9)=0.48, p=0.63) or VO2ss (F(2,9)=1.10, p=0.36) during the exercise bout. Conclusion: The findings suggest that a higher intensity WU improves factors related to improved aerobic performance, i.e. decreased O2 deficit and RPE, without adversely affecting factors that could lead to a decline in performance, i.e. increased HRss and VO2ss

Role of 5-HT receptor mechanisms in sub-chronic PCP-induced reversal learning deficits in the rat

YesRationale: 5-HT receptor mechanisms have been suggested to mediate improvements in cognition in schizophrenia. Aim: To investigate the involvement of 5-HT receptor mechanisms in sub-chronic PCP-induced reversal learning deficits in female rats, a task of relevance to schizophrenia. Methods: Adult female hooded-Lister rats were trained to perform an operant reversal learning task and then received sub-chronic PCP (2 mg/kg) or vehicle i.p. twice daily for seven days, followed by 7-days washout. Rats then received an acute dose of the 5-HT7 receptor antagonist SB-269970A (1.0, 3.0, 10.0 mg/kg; i.p.) or vehicle. In experiment 2, PCP-treated rats received the selective 5-HT2C receptor antagonist, SB-243213A acutely (1.0, 3.0, 10.0 mg/kg; i.p.) or vehicle. In experiment 3, PCP-treated rats received the 5-HT1A receptor partial agonist, buspirone (0.15625, 0.3125, 0.625 mg/kg, i.p.) in combination with the selective 5-HT1A receptor antagonist WAY-100635 (0.3, 1.0 mg/kg). Results: In all experiments sub-chronic PCP significantly impaired reversal phase performance (P<0.01-0.001), with no effect in the initial phase. SB-269970A at 3.0 and 10.0 mg/kg significantly improved the PCP-induced deficit (P<0.05). SB-243213A also significantly attenuated the deficit at 10 mg/kg (P<0.05). In experiment 3, buspirone attenuated the deficit with significant effects at 0.3125 mg/kg and 0.625 mg/kg (P<0.05). WAY-100635 at 0.3 and 1.0 mg/kg produced a partial attenuation of buspirone’s effect as buspirone (0.3125 mg/kg) in the presence of WAY-100635 did not significantly reverse the PCP-induced deficit. Conclusions: These studies implicate the role of 5-HT7, 5-HT2C and 5-HT1A receptors in the improvement of cognitive dysfunction of relevance to schizophrenia

Dissolution of the Disparate:Co-ordinate Regulation in Antibiotic Biosynthesis

Discovering new antibiotics is vital to combat the growing threat of antimicrobial resistance. Most currently used antibiotics originate from the natural products of actinomycete bacteria, particularly Streptomyces species, that were discovered over 60 years ago. However, genome sequencing has revealed that most antibiotic-producing microorganisms encode many more natural products than previously thought. Biosynthesis of these natural products is tightly regulated by global and cluster situated regulators (CSRs), most of which respond to unknown environmental stimuli, and this likely explains why many biosynthetic gene clusters (BGCs) are not expressed under laboratory conditions. One approach towards novel natural product discovery is to awaken these cryptic BGCs by re-wiring the regulatory control mechanism(s). Most CSRs bind intergenic regions of DNA in their own BGC to control compound biosynthesis, but some CSRs can control the biosynthesis of multiple natural products by binding to several different BGCs. These cross-cluster regulators present an opportunity for natural product discovery, as the expression of multiple BGCs can be affected through the manipulation of a single regulator. This review describes examples of these different mechanisms, including specific examples of cross-cluster regulation, and assesses the impact that this knowledge may have on the discovery of novel natural products

Isolated hip and ankle fatigue are unlikely risk factors for anterior cruciate ligament injury

Lower extremity neuromuscular fatigue purportedly increases anterior cruciate ligament (ACL) injury risk through promotion of extreme landing mechanics. However, the impact of fatigue on muscle groups critical to the landing strategy remains unclear. This study examined the effects of isolated hip rotator and triceps surae fatigue on lower extremity landing biomechanics. Sixteen healthy females (18–22 years) reported for testing on two occasions, with one muscle group fatigued per session. Subjects performed three single-leg landings onto a force platform pre- and post-fatigue, defined as an 80% decrease in peak torque in the targeted muscle group. Hip rotator fatigue was induced via alternating concentric contractions and triceps surae fatigue through concentric plantar flexion contractions on an isokinetic dynamometer. Initial contact (IC) kinematics and peak stance (PS) kinetics and kinematics were analyzed pre- and post-fatigue. Hip rotator fatigue increased IC ( P =0.05) and PS ( P =0.04) hip internal rotation angles. Triceps surae fatigue decreased IC knee flexion ( P =0.01) angle. Isolated hip rotator and triceps surae fatigue each produced modifications in lower limb kinematic parameters viewed as risk factors for ACL injury. These modifications, however, do not appear of sufficient magnitude to compromise ligament integrity, suggesting injury via an integrative lower extremity fatigue mechanism is more likely.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78722/1/j.1600-0838.2009.01076.x.pd

Vascular Changes Following Mucoperiosteal Flap Surgery: A Fluorescein Angiography Study in Dogs

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141266/1/jper0205.pd

The SYZ conjecture via homological mirror symmetry

These are expository notes based on a talk given at the Superschool on derived categories and D-branes at University of Alberta in July of 2016. The goal of these notes is to give a motivated introduction to the Strominger-Yau-Zaslow (SYZ) conjecture from the point of view of homological mirror symmetry.Comment: Contribution to the proceedings of the Superschool on derived categories and D-brane

Advances in actinomycete research: an ActinoBase review of 2019

The actinomycetes are Gram-positive bacteria belonging to the order Actinomycetales within the phylum Actinobacteria. They include members with significant economic and medical importance, for example filamentous actinomycetes such as Streptomyces species, which have a propensity to produce a plethora of bioactive secondary metabolites and form symbioses with higher organisms, such as plants and insects. Studying these bacteria is challenging, but also fascinating and very rewarding. As a Microbiology Society initiative, members of the actinomycete research community have been developing a Wikipedia-style resource, called ActinoBase, the purpose of which is to aid in the study of these filamentous bacteria. This review will highlight 10 publications from 2019 that have been of special interest to the ActinoBase community, covering 4 major components of actinomycete research: (i) development and regulation; (ii) specialized metabolites; (iii) ecology and host interactions; and (iv) technology and methodology

A Compact Torus Fusion Reactor Utilizing a Continuously Generated Strings of CT's. The CT String Reactor, CTSR.

A fusion reactor is described in which a moving string of mutually repelling compact toruses (alternating helicity, unidirectional Btheta) is generated by repetitive injection using a magnetized coaxial gun driven by continuous gun current with alternating poloidal field. An injected CT relaxes to a minimum magnetic energy equilibrium, moves into a compression cone, and enters a conducting cylinder where the plasma is heated to fusion-producing temperature. The CT then passes into a blanketed region where fusion energy is produced and, on emergence from the fusion region, the CT undergoes controlled expansion in an exit cone where an alternating poloidal field opens the flux surfaces to directly recover the CT magnetic energy as current which is returned to the formation gun. The CT String Reactor (CTSTR) reactor satisfies all the necessary MHD stability requirements and is based on extrapolation of experimentally achieved formation, stability, and plasma confinement. It is supported by extensive 2D, MHD calculations. CTSTR employs minimal external fields supplied by normal conductors, and can produce high fusion power density with uniform wall loading. The geometric simplicity of CTSTR acts to minimize initial and maintenance costs, including periodic replacement of the reactor first wall

Point Mutations in HpuB Enable Gonococcal HpuA Deletion Mutants To Grow on Hemoglobin

Neisseria gonorrhoeae ordinarily requires both HpuA and HpuB to use hemoglobin (Hb) as a source of iron for growth. Deletion of HpuA resulted in reduced Hb binding and failure of growth on Hb. We identified rare Hb-utilizing colonies (Hb+) from an hpuA deletion mutant of FA1090, which fell into two phenotypic classes. One class of the Hb+ revertants required expression of both TonB and HpuB for growth on Hb, while the other class required neither TonB nor HpuB. All TonB/HpuB-dependent mutants had single amino acid alterations in HpuB, which occurred in clusters, particularly near the C terminus. The point mutations in HpuB did not restore normal Hb binding. Human serum albumin inhibited Hb-dependent growth of HpuB point mutants lacking HpuA but did not inhibit growth when expression of HpuA was restored. Thus, HpuB point mutants internalized heme in the absence of HpuA despite reduced binding of Hb. HpuA facilitated Hb binding and was important in allowing use of heme from Hb for growth

Research Data Management 'Green Shoots' Pilot Programme, Final Reports

This document contains the final reports of six Research Data Management Green Shoots projects run at Imperial College in 2014