A method for the identification of COVID-19 biomarkers in human breath using Proton Transfer Reaction Time-of-Flight Mass Spectrometry

Background: COVID-19 has caused a worldwide pandemic, making the early detection of the virus crucial. We present an approach for the determination of COVID-19 infection based on breath analysis. Methods: A high sensitivity mass spectrometer was combined with artificial intelligence and used to develop a method for the identification of COVID-19 in human breath within seconds. A set of 1137 positive and negative subjects from different age groups, collected in two periods from two hospitals in the USA, from 26 August, 2020 until 15 September, 2020 and from 11 September, 2020 until 11 November, 2020, was used for the method development. The subjects exhaled in a Tedlar bag, and the exhaled breath samples were subsequently analyzed using a Proton Transfer Reaction Time-of-Flight Mass Spectrometer (PTR-ToF-MS). The produced mass spectra were introduced to a series of machine learning models. 70% of the data was used for these sub-models\u27 training and 30% was used for testing. Findings: A set of 340 samples, 95 positives and 245 negatives, was used for the testing. The combined models successfully predicted 77 out of the 95 samples as positives and 199 out of the 245 samples as negatives. The overall accuracy of the model was 81.2%. Since over 50% of the total positive samples belonged to the age group of over 55 years old, the performance of the model in this category was also separately evaluated on 339 subjects (170 negative and 169 positive). The model correctly identified 166 out of the 170 negatives and 164 out of the 169 positives. The model accuracy in this case was 97.3%. Interpretation: The results showed that this method for the identification of COVID-19 infection is a promising tool, which can give fast and accurate results

Long-term growth of diploid human fibroblasts in low serum media

Hayflick and Moorhead demonstrated that diploid human fibroblasts have a limited life span when grown in media containing 10% bovine calf sera. Recent experiments have suggested that antigrowth factors in serum may be a potential contributor to the limited proliferative capacity of normal diploid cells. To reduce the concentration of inhibitory serum factors 10-fold, MRC-5 diploid fibroblasts were cultured in media with only 1% serum. Long-term culture in 1% serum requires the addition of purified growth factors to sustain proliferation. Although there are dramatic changes in cell morphology, we find that the long-term division potential of MRC-5 cells cultured in media containing 1% serum and growth factors differs little from that found with cells cultured in 10% serum. In contrast, MRC-5 cells cultured in 10% serum and added growth factors have a somewhat extended life span. These results suggest that negative growth factors are not responsible for the limited proliferative capacity of in vitro cultured human fibroblasts. Moreover, the evidence that human fibroblasts can undergo major changes in cell morphology and still retain a normal life span raises questions about the validity of using morphological changes as indicators of cellular senescence.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28800/1/0000634.pd

PAID TO PUMP: How a tax credit could discourage conservation of the High Plains Aquifer

In 1965’s United States v. Shurbet case, an irrigator from Texas asserted his claim for a depletion tax deduction for groundwater pumped from the High Plains Aquifer. He argued that the unique conditions of the southern High Plains region - a plateau where the shallow aquifer is recharged only through precipitation at a slow rate - meant the groundwater resource would be depleted in time. The state argued that groundwater was not fundamentally an exhaustible natural deposit, but the Supreme Court concluded the tax deduction was appropriate given the “peculiar” conditions in the area. It was stated the decision was not meant to establish a precedent regarding cost depletion of groundwater. The findings of the Shurbet case were intended to be limited to the southern High Plains region. However, in a 1980 lawsuit against the IRS, the Gigot brothers of Kansas sought to expand the deduction to allow depletion of the aquifer beneath their 30,000 acre farm in Kansas. The case was settled in the district court with a ruling allowing the brothers’ deductions to continue, thereby extending the Shurbet decision to include all landowners extracting from the approximately 174,000 square miles of land overlying the High Plains Aquifer. Currently, the estimated value of the credit is highest in parts of northern Texas, eastern Colorado, western Kansas, and south central Nebraska

No evidence of transmission of grapevine leafroll-associated viruses by phylloxera (Daktulosphaira vitifoliae).

Grapevine leafroll disease is associated with several species of phloem-limited grapevine leafrollassociated viruses (GLRaV), some of which are transmitted by mealybugs and scale insects. The grape phylloxera, Daktulosphaira vitifoliae (Fitch) Biotype A (Hemiptera: Phylloxeridae), is a common vineyard pest that feeds on the phloem of vine roots. There is concern that these insects may transmit one or more GLRaV species, particularly GLRaV-2, a species in the genus Closterovirus. A field survey was performed in vineyards with a high incidence of grapevine leafroll disease and D. vitifoliae was assessed for acquisition of GLRaV. In greenhouse experiments, the ability of D. vitifoliae to transmit GLRaV from infected root sections or vines to co-planted virus-free recipient vines was tested. There were no GLRaV-positive D. vitifoliae in the field survey, nor did D. vitifoliae transmit GLRaV- 1, ?2, ?3, or -4LV in greenhouse transmission experiments. Some insects tested positive for GLRaV after feeding on infected source vines in the greenhouse, however there was no evidence of virus transmission to healthy plants. These findings, in combination with the sedentary behaviour of the soil biotype of D. vitifoliae, make it unlikely that D. vitifoliae is a vector of any GLRaV.DOI: 10.1007/s10658-016-1049-

Can Machines Garden? Systematically Comparing the AlphaGarden vs. Professional Horticulturalists

The AlphaGarden is an automated testbed for indoor polyculture farming which combines a first-order plant simulator, a gantry robot, a seed planting algorithm, plant phenotyping and tracking algorithms, irrigation sensors and algorithms, and custom pruning tools and algorithms. In this paper, we systematically compare the performance of the AlphaGarden to professional horticulturalists on the staff of the UC Berkeley Oxford Tract Greenhouse. The humans and the machine tend side-by-side polyculture gardens with the same seed arrangement. We compare performance in terms of canopy coverage, plant diversity, and water consumption. Results from two 60-day cycles suggest that the automated AlphaGarden performs comparably to professional horticulturalists in terms of coverage and diversity, and reduces water consumption by as much as 44%. Code, videos, and datasets are available at https://sites.google.com/berkeley.edu/systematiccomparison.Comment: International Conference on Robotics and Automation(ICRA) 2023 Ora

A Putative Leucine-Rich Repeat Receptor Kinase Involved in Brassinosteroid Signal Transduction

AbstractBrassinosteroids are a class of growth-promoting regulators that play a key role throughout plant development. Despite their importance, nothing is known of the mechanism of action of these steroid hormones. We describe the identification of 18 Arabidopsis dwarf mutants that are unable to respond to exogenously added brassinosteroid, a phenotype that might be expected for brassinosteroid signaling mutants. All 18 mutations define alleles of a single previously described gene, BRI1. We cloned BRI1 and examined its expression pattern. It encodes a ubiquitously expressed putative receptor kinase. The extracellular domain contains 25 tandem leucine-rich repeats that resemble repeats found in animal hormone receptors, plant disease resistance genes, and genes involved in unknown signaling pathways controlling plant development