Universal Chern number statistics in random matrix fields

We investigate the probability distribution of Chern numbers (quantum Hall effect integers) for a parametric version of the GUE random matrix ensemble, which is a model for a chaotic or disordered system. The numerically-calculated single-band Chern number statistics agree well with predictions based on an earlier study [O. Gat and M. Wilkinson, SciPost Phys., 10, 149, (2021)] of the statistics of the quantum adiabatic curvature, when the parametric correlation length is small. However, contrary to an earlier conjecture, we find that the gap Chern numbers are correlated, and that correlation is weak but slowly-decaying. Also, the statistics of weighted sums of Chern numbers for many bands differs markedly from predictions based upon the hypothesis that gap Chern numbers are uncorrelated. All our results are consistent with the universality hypothesis described in the earlier paper, including in the previously unstudied regime of large correlation length, where the Chern statistics is highly non-Gaussian.Comment: 16 pages, 6 figure

OPTIMIZING COST DISCUSSIONS BETWEEN ONCOLOGISTS AND PATIENTS TO REDUCE FINANCIAL TOXICITY: A QUALITATIVE STUDY OF ONCOLOGIST PERSPECTIVES

As the cost of cancer care continues to rise and patients shoulder increasing financial burden for their care, there is a growing sentiment within the oncology community that patients be clearly informed of their out-of-pocket (OOP) costs as part of delivering high quality cancer care. The American Society of Clinical Oncology (ASCO), in particular, has dedicated significant time and attention to raising awareness of the rising cost of cancer care, as well as emphasizing the importance of cost discussions between oncologists and their patients. Despite these efforts, cost discussions are not happening frequently, and there are no established models for how this communication should be integrated into oncology practice. This study used a qualitative methods approach to assess how doctor-patient discussions about cost can be optimized to reduce patient financial toxicity in the cancer setting. Semi- structured telephone interviews were conducted with clinical oncologists (n=24) in a variety of practice settings and disease specialties. Results showed oncologists view communicating with their patients about OOP costs as an important yet challenging aspect of care. The frequency and way in which cost conversations occur between oncologists and their patients vary significantly depending on practice setting and patient population served. The process of obtaining OOP cost information, in addition to the necessary steps required to obtain financial assistance, is a time- intensive, back-and-forth process that can increase patient anxiety and lead to delays in care. Primary barriers to OOP cost communication are lack of education, resources and a systemic process for identifying and mitigating financial toxicity. OOP cost estimator tools and payment models that incentivize OOP cost communication are facilitators for oncologists to have cost- related conversations with their patients. To effectively assist patients in understanding, minimizing and managing their OOP costs, physician and patient education, information-based solutions and a systems-based, whole care team approach are needed. Based on these findings, an overall strategy to be taken up and used by the oncology stakeholder community is proposed, as well as a set of recommendations for ASCO to implement as part of its efforts to improve cancer care.Doctor of Public Healt

Reviews of "A Prothrombotic Thrombocytopenic Disorder Resembling Heparin-Induced Thrombocytopenia Following Coronavirus-19 Vaccination"

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Universal Chern number statistics in random matrix fields

We investigate the probability distribution of Chern numbers (quantum Hall conductance integers) for a parametric version of the GUE random matrix ensemble, which is a model for a chaotic or disordered system. The numerically-calculated single-band Chern number statistics agree well with predictions based on an earlier study [O. Gat and M. Wilkinson, SciPost Phys., 10, 149, (2021)] of the statistics of the quantum adiabatic curvature, when the parametric correlation length is small. However, contrary to an earlier conjecture, we find that the gap Chern numbers are correlated, and that the correlation is weak but slowly-decaying. Also, the statistics of weighted sums of Chern numbers differs markedly from predictions based upon the hypothesis that gap Chern numbers are uncorrelated. All our results are consistent with the universality hypothesis described in the earlier paper, including in the previously unstudied regime of large correlation length, where the Chern statistics is highly non-Gaussian

Elevated atmospheric CO2 and humidity delay leaf fall in Betula pendula, but not in Alnus glutinosa or Populus tremula × tremuloides

Context: Anthropogenic activity has increased the level of atmospheric CO2, which is driving an increase of global temperatures and associated changes in precipitation patterns. At Northern latitudes, one of the likely consequences of global warming is increased precipitation and air humidity. Aims: In this work, the effects of both elevated atmospheric CO2 and increased air humidity on trees commonly growing in northern European forests were assessed. Methods: The work was carried out under field conditions by using Free Air Carbon dioxide Enrichment (FACE) and Free Air Humidity Manipulation (FAHM) systems. Leaf litter fall was measured over 4 years (FACE) or 5 years (FAHM) to determine the effects of FACE and FAHM on leaf phenology. Results: Increasing air humidity delayed leaf litter fall in Betula pendula, but not in Populus tremula × tremuloides. Similarly, under elevated atmospheric CO2, leaf litter fall was delayed in Betula pendula, but not in Alnus glutinosa. Increased CO2 appeared to interact with periods of low precipitation in summer and high ozone levels during these periods to effect leaf fall. Conclusions: This work shows that increased CO2 and humidity delay leaf fall, but this effect is species specific

Infection Strategies Deployed by Botrytis cinerea, Fusarium acuminatum, and Rhizopus stolonifer as a Function of Tomato Fruit Ripening Stage

Worldwide, 20–25% of all harvested fruit and vegetables are lost annually in the field and throughout the postharvest supply chain due to rotting by fungal pathogens. Most postharvest pathogens exhibit necrotrophic or saprotrophic lifestyles, resulting in decomposition of the host tissues and loss of marketable commodities. Necrotrophic fungi can readily infect ripe fruit leading to the rapid establishment of disease symptoms. However, these pathogens generally fail to infect unripe fruit or remain quiescent until host conditions stimulate a successful infection. Previous research on infections of fruit has mainly been focused on the host’s genetic and physicochemical factors that inhibit or promote disease. Here, we investigated if fruit pathogens can modify their own infection strategies in response to the ripening stage of the host. To test this hypothesis, we profiled global gene expression of three fungal pathogens that display necrotrophic behavior—Botrytis cinerea, Fusarium acuminatum, and Rhizopus stolonifer—during interactions with unripe and ripe tomato fruit. We assembled and functionally annotated the transcriptomes of F. acuminatum and R. stolonifer as no genomic resources were available. Then, we conducted differential gene expression analysis to compare each pathogen during inoculations versus in vitro conditions. Through characterizing patterns of overrepresented pathogenicity and virulence functions (e.g., phytotoxin production, cell wall degradation, and proteolysis) among the differentially expressed genes, we were able to determine shared strategies among the three fungi during infections of compatible (ripe) and incompatible (unripe) fruit tissues. Though each pathogen’s strategy differed in the details, interactions with unripe fruit were commonly characterized by an emphasis on the degradation of cell wall components, particularly pectin, while colonization of ripe fruit featured more heavily redox processes, proteolysis, metabolism of simple sugars, and chitin biosynthesis. Furthermore, we determined that the three fungi were unable to infect fruit from the non-ripening (nor) tomato mutant, confirming that to cause disease, these pathogens require the host tissues to undergo specific ripening processes. By enabling a better understanding of fungal necrotrophic infection strategies, we move closer to generating accurate models of fruit diseases and the development of early detection tools and effective management strategies

The development of N,N,N,N-tetradentate Fe(II) complexes for alkene and alcohol oxidation

MSc (Chemistry), North-West University, Potchefstroom Campus, 2018.We developed a catalyst system capable of oxidising olefinic and alcohol substrates under ambient air and at low temperatures. Our catalyst system comprises of an iron precursor in combination with a bis-heterocyclic diamine ligand set. These ligands have different steric and electronic properties, by i) varying the substituents on the pyridyl ring, and ii) varying the N-heterocycle. Firstly, we prepared a series of chiral (R,R) bis-heterocyclic secondary diamine ligands (L3.6 to L3.10; (R,R)-L3.6, heterocycle = pyridine; (R,R)-L3.7, heterocycle = 6-methyl-2-pyridine; (R,R)-L3.8, heterocycle = 6-bromo-2-pyridine; (R,R)-L3.9, heterocycle = 1-methyl-imidazole; (R,R)-L3.10, heterocycle = quinoline) and the corresponding iron(II) complexes (C3.1 to C3.5; (R,R)-C3.1, heterocycle = pyridine; (R,R)-C3.2, heterocycle = 6-methyl-2-pyridine; (R,R)-C3.3, heterocycle = 6-bromo-2-pyridine; (R,R)-C3.4, heterocycle = 1-methyl-imidazole; (R,R)-C3.5, heterocycle = quinoline). Nuclear magnetic resonance (NMR, 1H, 13C) spectroscopy, mass spectrometry (MS) and ultraviolet-visible (UV-Vis) spectroscopy were used to characterise these ligands and complexes. These complexes were investigated as catalysts in the oxidation of cis-cyclooctene. All the complexes exhibited similar catalytic activity, with turnover numbers between 9.60 and 12.70, which led us to believe that the complexes have low stability. This was confirmed with electrospray ionisation (ESI) MS, which indicated the oxidative degradation of the catalysts, which leads to lower stability and subsequently lower catalytic activity. To improve the stability, a series of chiral (R,R) and (S,S) bis-heterocyclic tertiary diamine ligands (L4.1 to L4.4; (R,R) and (S,S)-L4.1, heterocycle = pyridine; (R,R) and (S,S)-L4.2, heterocycle = 6-methyl-2-pyridine; (R,R) and (S,S)-L4.3, heterocycle = 6-bromo-2-pyridine; (R,R) and (S,S)-L4.4, heterocycle = 1-methyl-imidazole) and their Fe(II)-triflate complexes (C4.1 to C4.4; (R,R) and (S,S)-C4.1, heterocycle = pyridine; (R,R) and (S,S)-C4.2, heterocycle = 6-methyl-2-pyridine; (R,R) and (S,S)-C4.3, heterocycle = 6-bromo-2-pyridine; (R,R) and (S,S)-C4.4, heterocycle = 1-methyl-imidazole) was prepared. These complexes were characterised by a variety of spectroscopic and analytical techniques. These included NMR (1H, 13C) spectroscopy, MS, UV-Vis spectroscopy, elemental analysis and magnetic susceptibility. With the desired complexes in hand, we commenced their evaluation as catalysts in the oxidation of cis-cyclooctene and benzyl alcohol. Of the series of complexes evaluated, (R,R)-C4.1 was able to convert 96% of cis-cyclooctene to cyclooctene epoxide with 100% selectivity. The addition of substituents in the 6-position of the pyridine ring had a pronounced steric effect that resulted in the complexes favouring a high-spin configuration, which led to lower catalytic activity. Replacing the pyridine donor with an imidazole donor also displayed a steric effect, which resulted in a complex that possesses a weaker ligand field and lower catalytic activity. The addition of acetic acid to the oxidation system resulted in up to a 30% increase in the conversion. For benzyl alcohol oxidation, the highest conversion of 73% was seen when employing (S,S)-C4.1. Different parameters of the oxidation reaction were optimised, which included oxidant concentration and catalyst loading. The catalytic activity increased as the amount of H2O2 increased, but also resulted in over-oxidation to benzoic acid. Using 25 μmol of catalyst resulted in the highest catalytic activity. The limitations and functional group tolerance of this catalyst system were investigated by extending the alcohol substrate scope and this system was able to oxidise allylic, benzylic as well as aliphatic primary and secondary alcohols to the corresponding aldehyde and ketone products.National Research Foundation (NRF)Master

[Letter from Ann Swartzberg to Jack Davis and William R. McCarter, May 25, 1990]

Photocopy of a letter from Ann Swartzberg to Jack Davis and William R. McCarter about their work to gather funding to match the Getty Center's grant. Swartzberg makes mention of academic proposals that may need to be rewritten in a journalism or public relations style for better responses. A handwritten note at the top reads "Corresp. Imp. Proposal" and "File (underlined)"