COVID-19 Case Investigation and Contact Tracing in Central Washington State, June-July 2020.

OBJECTIVE: To evaluate participation in COVID-19 case investigation and contact tracing in central Washington State between June 15 and July 12, 2020. METHODS: In this retrospective observational evaluation we combined SARS-CoV-2 RT-PCR and antigen test reports from the Washington Disease Reporting System with community case investigation and contact tracing data for 3 health districts (comprising 5 counties) in central Washington State. All 3 health districts have large Hispanic communities disproportionately affected by COVID-19. RESULTS: Investigators attempted to call all referred individuals with COVID-19 (n = 4,987); 71% were interviewed. Of those asked about close contacts (n = 3,572), 68% reported having no close contacts, with similar proportions across ethnicity, sex, and age group. The 968 individuals with COVID-19 who named specific contacts (27% of those asked) reported a total of 2,293 contacts (mean of 2.4 contacts per individual with COVID-19); 85% of listed contacts participated in an interview. CONCLUSIONS: Most individuals with COVID-19 reported having no close contacts. Increasing community engagement and public messaging, as well as understanding and addressing barriers to participation, are crucial for CICT to contribute meaningfully to controlling the SARS-CoV-2 pandemic.

Agronomic Factors Associated with Bacterial Leaf Streak Development Caused by Xanthomonas vasicola pv. vasculorum in Corn.

In 2016, the bacterium Xanthomonas vasicola pv. vasculorum was reported causing bacterial leaf streak on Nebraska corn. Prior to this report, the pathogen was reported on corn only in South Africa. Hence, there was a lack of information about the effects of corn production practices on bacterial leaf streak development. A survey of growers, crop consultants, extension agents, and others in the field of agriculture was initiated during the 2016 and 2017 corn growing seasons to examine agronomic factors that may affect the disease. Survey respondents were asked to submit a symptomatic leaf sample for pathogen confirmation via polymerase chain reaction, along with a completed survey on corn production practices. Analyses of 325 survey responses via random forest analysis indicated that irrigation, planting date, and crop rotation were the three most important predictors of corn samples testing positive for X. vasicola pv. vasculorum. According to a classification and regression tree analysis, irrigation use, the V7-R2 range of crop stages, multiple years of corn in a crop rotation or a corn-sorghum rotation, and planting dates after 2 May, were most closely associated with corn samples testing positive for X. vasicola pv. vasculorum. χ2 tests of independence indicated that applications of nitrogen fertilizer and glyphosate herbicide use may also be related to bacterial leaf streak development.

1H MRS identifies symptomatic and asymptomatic subjects with partial ornithine transcarbamylase deficiency.

OBJECTIVE: To evaluate brain metabolism in subjects with partial ornithine transcarbamylase deficiency (OTCD) utilizing (1)H MRS. METHODS: Single-voxel (1)H MRS was performed on 25 medically-stable adults with partial OTCD, and 22 similarly aged controls. Metabolite concentrations from frontal and parietal white matter (FWM, PWM), frontal gray matter (FGM), posterior cingulate gray matter (PCGM), and thalamus (tha) were compared with controls and IQ, plasma ammonia, glutamine, and disease severity. RESULTS: Cases ranged from 19 to 59 years; average 34 years; controls ranged from 18 to 59 years; average 33 years. IQ scores were lower in cases (full scale 111 vs. 126; performance IQ 106 vs. 117). Decreased myoinositol (mI) in FWM (p=0.005), PWM (p<0.001), PCGM (p=0.003), and tha (p=0.004), identified subjects with OTCD, including asymptomatic heterozygotes. Glutamine (gln) was increased in FWM (p<0.001), PWM (p<0.001), FGM (p=0.002), and PCGM (p=0.001). Disease severity was inversely correlated with [mI] in PWM (r=-0.403; p=0.046) and directly correlated with [gln] in PCGM (r=0.548; p=0.005). N-Acetylaspartate (NAA) was elevated in PWM (p=0.002); choline was decreased in FWM (p=0.001) and tha (p=0.002). There was an inverse relationship between [mI] and [gln] in cases only. Total buffering capacity (measured by [mI/mI+gln] ratio, a measure of total osmolar capacity) was inversely correlated with disease severity in FWM (r=-0.479; p=0.018), PWM (r=-0.458; p=0.021), PCGM (r=-0.567; p=0.003), and tha (r=-0.345; p=0.037). CONCLUSION: Brain metabolism is impaired in partial OTCD. Depletion of mI and total buffering capacity are inversely correlated with disease severity, and serve as biomarkers.

Quantum Estimation of Parameters of Classical Spacetimes.

We describe a quantum limit to measurement of classical spacetimes. Specifically, we formulate a quantum Cramér-Rao lower bound for estimating the single parameter in any one-parameter family of spacetime metrics. We employ the locally covariant formulation of quantum field theory in curved spacetime, which allows for a manifestly background-independent derivation. The result is an uncertainty relation that applies to all globally hyperbolic spacetimes. Among other examples, we apply our method to detection of gravitational waves with the electromagnetic field as a probe, as in laser-interferometric gravitational-wave detectors. Other applications are discussed, from terrestrial gravimetry to cosmology.

The efficacy of carbamazepine combinations in epilepsy.

The efficacy and bioavailability, and tolerance to carbamazepinee when administered with phenobarbital or phenytoin or with both drugs were evaluated in a prospective, double-blind study of patients whose seizures were not completely controlled by currently available antiepileptic drugs in usually therapeutic dosages as determined by serum levels. During each of four 21-day treatment periods, one fourth of the patients received daily doses of: (1) carbamazepine (1,200 mg) and phenytoin (300 mg); (2) carbamazepine (1,200 mg) and phenobarbital (300 mg); (3) phenytoin (300 mg) and phenobarbital (300 mg); or (4) carbamazepine (1,200 mg), with phenytoin (300 mg) and phenobarbital (300 mg). The treatment periods were separated by 2 wk of each patient's usual prestudy medication. Treatment with all three drugs was the most efficacious for seizure control. Serum carbamazepine concentration was significantly decreased when the drug was administered with either phenytoin or phenobarbital or both.

Attention-related modulation of activity in primary and secondary auditory cortex.

We investigated the effects of auditory attention on brain activity using functional magnetic resonance imaging. Subjects listened to three word lists, three times each, and were instructed to count the number of times they heard a target word during two of these presentations. For the third, they listened to the words without counting. All subjects showed significant areas of activation in auditory cortex during the listening conditions compared to rest. There was significantly more activation and a larger area of activation, particularly in association cortex, in the left temporal lobe during counting of targets compared to the no-target conditions, with a similar trend in the right hemisphere. These results provide evidence of an attention-related enhancement of both activation magnitude and extent in auditory cortex.

An epidemiological study of severe osteoarthritis.

A study was made of the relationship between weight, education, use of tobacco and alcohol, participation in athletics and family history of arthritis and severe osteoarthritis of the hip. Estimated relative risk of osteoarthritis was highest for those whose weight was at least 20% or more above ideal, having more than a high school education or with a familial history of arthritis. There was no association between severe osteoarthritis and participation in high school athletics or regular use of alcohol.

Diffusion tensor imaging detects areas of abnormal white matter microstructure in patients with partial ornithine transcarbamylase deficiency.

BACKGROUND AND PURPOSE: OTCD, an X-linked disorder, is the most common of the UCDs. Neonatal onset is associated with uniformly poor outcome. Males with late-onset OTCD show deficits in executive function, motor planning, and working memory. A broad phenotype is observed in heterozygous females. A specific neurobehavioral phenotype with white matter dysfunction and impaired attention and working memory has been described. The extent to which the deficits involve specific pathways in the brain is unknown. We hypothesized that DTI would disclose white matter microstructure in OTCD correlating with cognitive deficits. MATERIALS AND METHODS: Nineteen adults with partial OTCD and 18 adult control subjects ages 19-59 years participated. MR imaging was performed by using a 3T whole-body scanner. Anisotropy was calculated from the eigenvalues of the diffusion tensor by using the FA metric and was compared between the study and control groups. RESULTS: FA of the frontal white matter was significantly decreased in subjects, indicating changes in white matter microstructure. There was an inverse relationship between FA and disease severity, but not with age. CONCLUSIONS: Findings of MR imaging in OTCD are often normal in patients with late-onset disease, heterozygotes, or in those not in hyperammonemic crisis. DTI was more sensitive than FSE T2-weighted imaging for detecting abnormalities in normal-appearing white matter. The extent of abnormality correlated with cognitive deficits. The location of the deficits in the frontal white matter is important because this area connects fibers that are vital to executive function, attention, and working memory.

Surface replacement hip arthroplasty: results of the first seventy-four consecutive cases at the University of California, San Francisco.

Although surface replacement hip arthroplasty has been viewed by some as a conservative alternative to conventional total hip arthroplasty, the surgical technique requires substantially more acetabular bone loss. To evaluate the efficacy of this operation, a retrospective study of 74 consecutive cases of surface replacement hip arthroplasty done at the University of California, San Francisco between February 1977 and June 1980 is reported and concludes that (1) there was no noteworthy difference in end result between cases using the Indiana, THARIES, or Freeman prostheses; (2) although there were major improvements in pain, function, and range of motion, unexplained pain persisted in 51.6% of cases; (3) the failure rate of 33.8% in the first 3 years was higher than that reported for conventional total hip arthroplasty; and (4) hips with a history of trauma failed the most frequently and showed the least improvement, whereas hips with osteoarthritis showed the fewest failures and the best results. We conclude that surface replacement hip arthroplasty is not superior to conventional total hip arthroplasty, judged by the criteria of pain relief, improvement of function, and failure rate.

Radiative corrections in symmetrized classical electrodynamics

The physics of radiation reaction for a point charge is discussed within the context of classical electrodynamics. The fundamental equations of classical electrodynamics are first symmetrized to include magnetic charges: a double four-potential formalism is introduced, in terms of which the field tensor and its dual are employed to symmetrize Maxwell's equations and the Lorentz force equation in covariant form. Within this framework, the symmetrized Dirac-Lorentz equation is derived, including radiation reaction (self-force) for a particle possessing both electric and magnetic charge. The connection with electromagnetic duality is outlined, and an in-depth discussion of nonlocal four-momentum conservation for the wave-particle system is given.

A multiple-dose study of mexiletine (Kö 1173).

In preparation for a prospective controlled study of mexiletine in the treatment of epilepsy, a preliminary study of serum concentrations after multiple doses was performed with 8 institutionalized Caucasian adult males with uncontrolled seizures and similar weight, medical regimen, and seizure classification. Two patients each received daily dosages of 200, 400, 600 or 800 mg mexiletine administered in capsules four times a day for 7 days, in addition to their usual medication. Serum concentrations of mexiletine were determined by the Kupferberg-Yonekawa method. After the first day, serum concentrations of mexiletine were significantly higher for the 600 and 800-mg dosages than for the 200- and 400-mg dosages. The differences in serum concentration between the 200- and 400-mg dosages and between the 600- and 800-mg dosages were not significant. Serum concentrations for the 200-mg and 400-mg dosages were generally below 400 ng/ml, whereas at dosages of 600- and 800-mg, serum concentrations ranged from 400 to over 1,100 ng/ml, after the first day. Optimal dosage for this population appeared to be at least 800 mg/day. Half-life ranged from 3.5 to 7.8 hr.

Vacuum electron acceleration by coherent dipole radiation.

The validity of the concept of laser-driven vacuum acceleration has been questioned, based on an extrapolation of the well-known Lawson-Woodward theorem, which stipulates that plane electromagnetic waves cannot accelerate charged particles in vacuum. To formally demonstrate that electrons can indeed be accelerated in vacuum by focusing or diffracting electromagnetic waves, the interaction between a point charge and coherent dipole radiation is studied in detail. The corresponding four-potential exactly satisfies both Maxwell's equations and the Lorentz gauge condition everywhere, and is analytically tractable. It is found that in the far-field region, where the field distribution closely approximates that of a plane wave, we recover the Lawson-Woodward result, while net acceleration is obtained in the near-field region. The scaling of the energy gain with wave-front curvature and wave amplitude is studied systematically.

PET reveals occipitotemporal pathway activation during elementary form perception in humans.

To define brain regions involved in feature extraction or elementary form perception, regional cerebral blood flow (rCBF) was measured using positron emission tomography (PET) in subjects viewing two classes of achromatic textures. Textures composed of local features (e.g. extended contours and rectangular blocks) produced activation or increased rCBF along the occipitotemporal pathway relative to textures with the same mean luminance, contrast, and spatial-frequency content but lacking organized form elements or local features. Significant activation was observed in striate, extrastriate, lingual, and fusiform cortices as well as the hippocampus and brain stem. On a scan-by-scan basis, increases in rCBF shifted from the occipitotemporal visual cortices to medial temporal (hippocampus) and frontal lobes with increased exposure to only those textures containing local features. These results suggest that local feature extraction occurs throughout the occipitotemporal (ventral) pathway during extended exposure to visually salient stimuli, and may indicate the presence of similar receptive-field mechanisms in both occipital and temporal visual areas of the human brain.