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1.
Appl Opt ; 62(8): 1871-1885, 2023 Mar 10.
Article in English | MEDLINE | ID: mdl-37133069

ABSTRACT

The low-latency adaptive optical mirror system (LLAMAS) is designed to push the limits on achievable latencies and frame rates. It has 21 subapertures across its pupil. A reformulated version of the linear quadratic Gaussian (LQG) method predictive Fourier control is implemented in LLAMAS; for all modes, it takes just 30 µs to compute. In the testbed, a turbulator mixes hot and ambient air to produce wind-blown turbulence. Wind prediction clearly improves correction when compared to an integral controller. Closed-loop telemetry shows that wind-predictive LQG removes the characteristic "butterfly" and reduces temporal error power by up to a factor of three for mid-spatial frequency modes. Strehl changes seen in focal plane images are consistent with telemetry and the system error budget.

2.
Amino Acids ; 48(3): 733-750, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26507545

ABSTRACT

We compared immediate post-exercise whey protein (WP, 500 mg) versus L-leucine (LEU, 54 mg) feedings on skeletal muscle protein synthesis (MPS) mechanisms and ribosome biogenesis markers 3 h following unilateral plantarflexor resistance exercise in male, Wistar rats (~250 g). Additionally, in vitro experiments were performed on differentiated C2C12 myotubes to compare nutrient (i.e., WP, LEU) and 'exercise-like' treatments (i.e., caffeine, hydrogen peroxide, and AICAR) on ribosome biogenesis markers. LEU and WP significantly increased phosphorylated-rpS6 (Ser235/236) in the exercised (EX) leg 2.4-fold (P < 0.01) and 2.7-fold (P < 0.001) compared to the non-EX leg, respectively, whereas vehicle-fed control (CTL) did not (+65 %, P > 0.05). Compared to the non-EX leg, MPS levels increased 32 % and 52 % in the EX leg of CTL (P < 0.01) and WP rats (P < 0.001), respectively, but not in LEU rats (+15 %, P > 0.05). Several genes associated with ribosome biogenesis robustly increased in the EX versus non-EX legs of all treatments; specifically, c-Myc mRNA, Nop56 mRNA, Bop1 mRNA, Ncl mRNA, Npm1 mRNA, Fb1 mRNA, and Xpo-5 mRNA. However, only LEU significantly increased 45S pre-rRNA levels in the EX leg (63 %, P < 0.001). In vitro findings confirmed that 'exercise-like' treatments similarly altered markers of ribosome biogenesis, but only LEU increased 47S pre-rRNA levels (P < 0.01). Collectively, our data suggests that resistance exercise, as well as 'exercise-like' signals in vitro, acutely increase the expression of genes associated with ribosome biogenesis independent of nutrient provision. Moreover, while EX with or without WP appears superior for enhancing translational efficiency (i.e., increasing MPS per unit of RNA), LEU administration (or co-administration) may further enhance ribosome biogenesis over prolonged periods with resistance exercise.


Subject(s)
Leucine/metabolism , Muscle, Skeletal/metabolism , Protein Biosynthesis , Resistance Training , Ribosomes/metabolism , Whey Proteins/metabolism , Animals , Humans , Male , Nuclear Proteins/genetics , Nuclear Proteins/metabolism , Nucleophosmin , Rats , Rats, Wistar , Ribosomal Protein S6/genetics , Ribosomal Protein S6/metabolism , Ribosomes/genetics
3.
World Rev Nutr Diet ; 105: 90-96, 2013.
Article in English | MEDLINE | ID: mdl-23075590

ABSTRACT

Glutamine (GLN) has been shown to be a key pharmaconutrient in the body's response to stress and injury. It exerts its protective effects via multiple mechanisms, including direct protection of cells and tissue from injury, attenuation inflammation, and preservation of metabolic function. Data support GLN as an ideal pharmacologic intervention to prevent or treat multiple organ dysfunction syndrome after sepsis or other injuries in the intensive care unit (ICU) population. A large and growing body of clinical data shows that GLN can be a life-saving intervention in well-defined critically ill patient groups. Recent data has helped clarify that GLN shows the greatest benefit when administered at doses greater than 0.35 g/kg/day, with optimal benefit potentially occurring at 0.5 g/kg/day. Further, it appears that when possible GLN should be administered for longer than 5 days and more ideally for the entire period of ICU or hospital stay. Finally, ongoing clinical trials may prove GLN administration in the first 24-48 h following ICU admission and via both the enteral and parenteral route are key to optimizing patient outcomes with this therapy.


Subject(s)
Glutamine/administration & dosage , Glutamine/therapeutic use , Craniocerebral Trauma/drug therapy , Critical Illness/therapy , Dose-Response Relationship, Drug , Enteral Nutrition , Humans , Hyperglycemia/prevention & control , Insulin Resistance , Intensive Care Units , Parenteral Nutrition , Randomized Controlled Trials as Topic , Treatment Outcome
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