Propagation of Errors for Matrix Inversion

A formula is given for the propagation of errors during matrix inversion. An explicit calculation for a 2 by 2 matrix using both the formula and a Monte Carlo calculation are compared. A prescription is given to determine when a matrix with uncertain elements is sufficiently nonsingular for the calculation of the covariances of the inverted matrix elements to be reliable.Comment: 18 pages, 4 figures, figure 4 contains two eps file

The Effect of Tactical Tasks and Gear on Muscle Activation of SWAT Officers

Special Weapons and Tactics (SWAT) officers constitute a subgroup of specialized law enforcement officers that perform a variety of tactical operations while wearing approximately 40 kg of tactical gear. Lower back pain is a prevalent musculoskeletal injury suffered by SWAT officers. Tactical gear places significant stress on the lower back. Thus, it is important to quantify the effect that tactical gear has on muscle activation levels of torso musculature while performing occupational tasks. Electromyography was evaluated on 20 male subjects (age: 34.7±4.5 yr.; height: 1.79±.10 m; body mass: 91.53±17.32 kg; mass of gear: 13.82±1.90 kg) while performing four tactical tasks (standing, rifle walk, sitting, & shield walk) with and without gear. Electromyography was evaluated bilaterally on the erector spinae, rectus abdominis, and external oblique muscles. The dominant erector spinae (mean delta: +0.16%) and external oblique (mean delta: -0.124%) demonstrated significant changes in muscle activation with the addition of gear, which may indicate increased spinal compression. There were also trends of increased co-activation of core musculature with the addition of gear. The rifle walk and shield walk task mean muscle activations were significantly higher than the standing and sitting tasks. The shield walk produced the highest mean activations for each muscle. Physical training for SWAT officers should emphasize exercises that simulate task-specific movement patterns without gear to decrease the spinal compression associated with load carriage

Notes on the Geology of the McCall Valley Area

Describes mainly the glacial geology of this V-shaped valley, approx. 10 km long and, 800 m wide, cut by McCall Glacier (69 20 N, 144 15 W) and Jago River valley in northern Alaska. The bedrock consists of north-dippping sediments of Upper Mississippian Lisburne limestone and the Permian Sadlerochit formation which abut against a granite batholith. Characteristic deposits of five glacial advances were examined by the author during the McCall Glacier Project in 1957-58, and their sequence correlated with that of the central Brooks Range. Beginning with the earliest, they correspond to the Anaktuvuk or Sagavanirktok, Itkillik, Echooka, Alapah Mountain and Fan Mountain glaciations. Some patterned ground features are described; also an aufeis field from which water was issuing in April, far in advance of the ablation season

Gene Therapy for Very Long Chain Acyl-coA Dehydrogenase Deficiency Using Adeno-Associated Virus Vectors: A Dissertation

Very long chain acyl-coA dehydrogenase (VLCAD) is the rate-limiting step in mitochondrial fatty acid oxidation. VLCAD deficient mice and patients’ clinical symptoms stem from not only an energy deficiency but also long-chain metabolite accumulations. VLCAD deficient mice were treated systemically with 1x10 12 vector genomes of rAAV9-VLCAD. Expression was detected in the liver, heart and muscle. Also substantial expression of VLCAD was noted in the brain, where it was expressed across different sections of the brain and in different cell types with different morphologies. Biochemical correction was observed in vector-treated mice beginning two weeks post-injection, as characterized by a significant drop in long chain fatty acyl accumulates in whole blood after an overnight fast. Changes persisted through the termination point around 20 weeks post injection. Magnetic resonance spectroscopy (MRS) and tandem mass spectrometry (MS/MS) revealed normalization of intramuscular lipids in treated animals. Correction was not observed in liver tissue extracts, but cardiac muscle extracts showed significant reduction of long chain metabolites. Disease-specific phenotypes were characterized, including thermoregulation and maintenance of euglycemia after a fasting cold challenge. Internal body temperatures of untreated VLCAD-/- mice dropped below 20°C and the mice became lethargic, requiring euthanasia. In contrast all rAAV9-treated VLCAD-/- mice and the wild-type controls maintained body temperatures. rAAV9-treated VLCAD-/- mice maintained euglycemia, whereas untreated VLCAD-/- mice suffered hypoglycemia following a fasting cold challenge. These promising results suggest rAAV9 gene therapy as a potential treatment for VLCAD deficiency in humans

First Occurrence of \u3ci\u3eHippodamia Variegata\u3c/i\u3e (Goeze) (Coleoptera: Coccinellidae) in Ohio

(excerpt) Ladybird beetles, or coccinellids (Coleoptera: Coccinellidae), are significant arthropod predators in a variety of terrestrial ecosystems. Numerous classical biological control projects undertaken over the last 120 years in North America have involved importation of exotic ladybird beetle species for the control of invasive insect species in annual and perennial agricultural production systems

Cell and gene therapy for genetic diseases: inherited disorders affecting the lung and those mimicking sudden infant death syndrome

Some of the first human gene therapy trials targeted diseases of the lung and provided important information that will continue to help shape future trials. Here we describe both cell and gene therapies for lung diseases such as cystic fibrosis and alpha-1 antitrypsin disorder as well as fatty acid oxidation disorders that mimic sudden infant death syndrome (SIDS). Human clinical gene therapy trials for cystic fibrosis and alpha-1 antitrypsin have been performed using a variety of vectors including adenovirus, adeno-associated virus, and nonviral vectors. No human clinical gene therapy trials have been performed for disorders of fatty acid oxidation; however, important proof-of-principle studies have been completed for multiple fatty acid oxidation disorders. Important achievements have been made and have yet to come for cell and gene therapies for disorders of the lung and those mimicking SIDS

Requirement of Fc-Fc gamma receptor interaction for antibody-based protection against emerging virus infections

Identification of therapeutics against emerging and re-emerging viruses remains a continued priority that is only reinforced by the recent SARS-CoV-2 pandemic. Advances in monoclonal antibody (mAb) isolation, characterization, and production make it a viable option for rapid treatment development. While mAbs are traditionally screened and selected based on potency of neutralization in vitro, it is clear that additional factors contribute to the in vivo efficacy of a mAb beyond viral neutralization. These factors include interactions with Fc receptors (FcRs) and complement that can enhance neutralization, clearance of infected cells, opsonization of virions, and modulation of the innate and adaptive immune response. In this review, we discuss recent studies, primarily using mouse models, that identified a role for Fc-FcγR interactions for optimal antibody-based protection against emerging and re-emerging virus infections

Instruments and methods: a method for recording ice ablation using a low-cost ultrasonic rangefinder

We have adapted inexpensive ultrasonic rangefinders to measure ablation rates on the surface of a glacier.While ultrasonic rangers are commercially available for this purpose, our goal was to utilize rangefinders typically used in hobby robotics without significantly compromising performance. To correct for environmental factors that affect the speed of sound we use two ultrasonic rangefinders, one focused on a fixed target. Measurements of ablation correlate well with manual measurements with an uncertainty of about 3 cm, suggesting an accuracy comparable with other non-manual methods of recording ablation. The limitations of our rangefinder include those inherent in commercially available units as well as having less acoustical power, which results in a reduced effective range of the sensor (2m) and difficulties in detecting surfaces lying below low-density snow. Our sensor design provides a cost-effective means of increasing the spatial coverage of ice ablation measurements

Analytical Formulas for Mean Gain and Excess Noise Factor in InAs Avalanche Photodiodes

It has been known that McIntyre\u27s local multiplication theory for avalanche photodiodes (APDs) does not fully explain the experimental results for single-carrier InAs APDs, which exhibit excess noise factor values below 2. While it has been established that the inclusion of the dead-space effect in the nonlocal multiplication theory resolves this discrepancy, no closed-form formulas for the mean gain and excess noise factor have been specialized to InAs APDs in a nonlocal setting. Upon utilizing prior analytical formulation of single-carrier avalanche multiplication based on age-dependent branching theory in conjunction with nonlocal ionization coefficients and thresholds for InAs, closed-form solutions of the mean gain and the excess noise factor for InAs APDs are provided here for the first time. The formulas are validated against published experimental data from InAs APDs across a variety of multiplication region widths and are shown to be applicable for devices with multiplication widths of 500 nm and larger