Nitrogen contributions of alley cropped Trifolium pratense may sustain short rotation woody crop yields on marginal lands

Nutrient Cycling in Agroecosystems - Incorporating nitrogen-fixing cover crops into short rotation woody crop (SWRC) plantations may increase soil and tree nitrogen while sustaining, or even...     

Investigation of a heat stress-related death of a fire fighter

The National Institute for Occupational Safety and Health (NIOSH) Division of Surveillance, Hazard Evaluations and Field Studies (DSHEFS) conducts investigations of health hazards in the workplace under the NIOSH Health Hazard Evaluation (HHE) program. In September 1990, the International Association of Fire Fighters (IAFF) requested that NIOSH assess the health and safety practices used by fire personnel during a brush fire on September 6, 1990, in Sedgwick County, Kansas. A 25-year-old fire fighter died of heat stroke at the scene.The NIOSH site visit to Sedgwick County, Kansas included a tour of the fire scene, personal interviews with 25 fire fighters and support personnel, and a review of incident reports, incident command procedures and other documents. NIOSH investigators concluded that a preventable series of events preceded the fire fighter's death. Recommendations were made for incident command and safety procedures, as well as medical monitoring, rehabilitation of fire fighters at fire scenes, and rehydration schedules.     

Evaluating the effectiveness of combined-cycle power plants and heat pumps in ferrous metallurgy

Metallurgist - Results are presented from an environmental-energy analysis of the potential use of combined-cycle power plants and heat-pump units in metallurgy. The effectiveness of these...     

Controlled-Potential Differential DC Polarography. V. Subtractive Polarography

SUMMARY

Subtractive polarography is a differential polarographic technique that allows the measurement of wanted signals in the presence of unwanted signals. The technique requires two polarographic cells, with DME's operated at the same potential. The “unknown” solutionis placed in one cell and gives rise to the total current. The solution in the second cell contains those components of the “unknown” solution that give rise to the unwanted portion of the total signal. Measurement of the difference between the polarographic currents at the electrodes in the two solutions thus yields the wanted portion of the total signal. This technique has been evaluated with a controlled-potential differential dc polarograph that utilizes dropping-mercury electrodes having uncontrolled drop times, and the results are presented in this paper. The results indicate that subtractive polarography affords improved sensitivity, selectivity, and resolution over that of conventional dc polarography, and an improvement in resolution over that of derivative polarography. An additional improvement in resolution can be achieved by means of derivative subtractive polarography.     

Protein Expression of Angiotensin-Converting Enzyme 2 (ACE2) is Upregulated in Brains with Alzheimer’s Disease

Alzheimer’s disease is a chronic neurodegenerative disorder and represents the main cause of dementia globally. Currently, the world is suffering from the coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a virus that uses angiotensin-converting enzyme 2 (ACE2) as a receptor to enter the host cells. In COVID-19, neurological manifestations have been reported to occur. The present study demonstrates that the protein expression level of ACE2 is upregulated in the brain of patients with Alzheimer’s disease. The increased ACE2 expression is not age-dependent, suggesting the direct relationship between Alzheimer’s disease and ACE2 expression. Oxidative stress has been implicated in the pathogenesis of Alzheimer’s disease, and brains with the disease examined in this study also exhibited higher carbonylated proteins, as well as an increased thiol oxidation state of peroxiredoxin 6 (Prx6). A moderate positive correlation was found between the increased ACE2 protein expression and oxidative stress in brains with Alzheimer’s disease. In summary, the present study reveals the relationships between Alzheimer’s disease and ACE2, the receptor for SARS-CoV-2. These results suggest the importance of carefully monitoring patients with both Alzheimer’s disease and COVID-19 in order to identify higher viral loads in the brain and long-term adverse neurological consequences.     

POLYCYCLIC AROMATIC HYDROCARBON O-QUINONES MUTATE p53 IN HUMAN LUNG ADENOCARCINOMA (A549) CELLS

Human lung adenocarcinoma (A549) cells form reactive and redox active PAH-o-quinones via constitutively expressed aldo-keto reductases. To determine whether these metabolites mutate p53, A549 cells were treated with N-methyl-N-nitroso-N-nitroguanidine (MNNG an alkylating mutagen), anti-BPDE (diol-epoxide) and benzo[a]pyrene-7,8-dione (o-quinone). p53 cDNA was amplified from the treated cells and cotransfected with a gap-repair plasmid designed to express p53 in yeast. When mutant p53 is expressed, it fails to drive the expression of an ADE2 reporter, and the yeast strain yIG397 turns red. The following mutational frequencies were observed versus the solvent controls: 1 mM MNNG (24.2% red colonies p = .02), 1 μ M anti-BPDE (9.9% red colonies p = .02), and 10 μ M BP-7,8-dione (9.3% red colonies p = .03). MNNG gave a high frequency (49%) of the expected C > T (G > A) mutations (p = .25). While anti-BPDE and BP-7,8-dione gave A > G (T > C) transitions (p = .034 – p = .054). These mutations would result from stable N⁶-deoxyadenosine adducts, but not from oxidatively damaged bases.     

Abnormally rapid disengagement of covert attention to global and local stimulus levels may underlie the visuoperceptual impairment in Parkinson's patients.

Parkinson's disease (PD) patients were administered a divided attention task that involved the use of global-local stimuli. Across two consecutive trials, the target could appear at either the same global-local level or at the other level. When the target remained at the same level across two consecutive trials, the PD patients responded slower than normal controls to the second stimulus relative to the first. In addition, when the target changed levels across consecutive trials, the PD patients responded faster than normal controls to the second stimulus relative to the first. These results suggest that PD patients may show an abnormally rapid disengagement of attention. The PD patients' abnormal shifting of covert attention was significantly related to the number of perceptual errors they made in identifying target stimuli, suggesting that a deficiency in maintaining covert attention may underlie the visuoperceptual impairment in PD patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A multiplexed protein kinase assay

We report a novel protein kinase assay designed for high-throughput detection of one or many kinases in a complex mixture. A solution-phase phosphorylation reaction is performed on 900 different peptide substrates, each covalently linked to an oligonucleotide tag. After incubation, phosphoserine, phosphothreonine, and phosphotyrosine are chemically labeled, and the substrates are hybridized to a microarray with oligonucleotides complementary to the tags to read out the phosphorylation state of each peptide. Because protein kinases act on more than one peptide sequence, each kinase can be characterized by a unique signature of phosphorylation activity on multiple substrates. Using this method, we determined signatures for 26 purified kinases and demonstrated that enzyme mixtures can be screened for activity and selectivity of inhibition.