Numerically-aware orderings for sparse symmetric indefinite linear systems

Sparse symmetric indefinite problems arise in a large number of important application areas; they are often solved through the use of an LDLT factorization via a sparse direct solver. Whilst for many problems, prescaling the system matrix A is sufficient to maintain stability of the factorization, for a small but important fraction of problems numerical pivoting is required. Pivoting often incurs a significant overhead and consequently a number of techniques have been proposed to try and limit the need for pivoting. In particular, numerically-aware ordering algorithms may be used, that is, orderings that depend not only on the sparsity pattern of A but also on the values of its (scaled) entries. Current approaches identify large entries of A and symmetrically permute them onto the subdiagonal where they can be used as part of a 2x2 pivot. This is numerically effective, but the fill in the factor L and hence the runtime of the factorization and subsequent triangular solves may be significantly increased over a standard ordering if no pivoting is required. We present a new algorithm that combines a matching-based approach with a numerically-aware nested dissection ordering. Numerical comparisons with current approaches for some tough symmetric indefinite problems are given

The roles of family members, health care workers, and others in decision-making processes about genetic testing among individuals at risk for Huntington disease

Purpose: To understand how individuals at risk for Huntington disease view the roles of others, e.g., family members and health care workers, in decision making about genetic testing. Methods: Twenty-one individuals (eight mutation-positive, four mutation-negative, and nine not tested) were interviewed for approximately 2 hours each. Results: Interviewees illuminated several key aspects of the roles of family members and health care workers (in genetics and other fields) in decision making about testing that have been underexplored. Family members often felt strongly about whether an individual should get tested. Health care workers provided information and assistance with decision making and mental health referrals that were often helpful. Yet health care workers varied in knowledge and sensitivity regarding testing issues, and the quality of counseling and testing experiences can range widely. At times, health care workers without specialized knowledge of Huntington disease offered opinions of whether to test. Input from families and health care workers could also conflict with each other and with an individual's own preferences. Larger institutional and geographic contexts shaped decisions as well. Conclusion: Decision-making theories applied to Huntington disease testing have frequently drawn on psychological models, yet the current data highlight the importance of social contexts and relationships in testing decisions. This report, the first to our knowledge to explore individuals' perceptions of social factors (particularly family and health care worker involvement) in Huntington disease testing decisions, has critical implications for practice, education, research, and policy

Transient band keratopathy associated with ocular inflammation and systemic hypercalcemia

Anat Galor, Henry A Leder, Jennifer E Thorne, James P DunnThe Wilmer Eye Institute, Department of Ophthalmology, the Johns Hopkins University School of MedicinePurpose: To report a case of visually significant band keratopathy associated with ocular inflammation and systemic hypercalcemia which markedly decreased in severity after treatment of these underlying factors.Methods: Retrospective case report.Results: A 53-year-old Asian female with granulomatous panuveitis in the left eye presented with diffuse band keratopathy through the central cornea. The serum calcium was elevated. The patient was treated with topical prednisolone acetate 1% and oral prednisone with marked improvement in inflammation. The band keratopathy lessened in severity with clearing of the central cornea and improvement in visual acuity.Conclusions: Early medical treatment of underlying factors may allow reversal of band keratopathy.Keywords: ocular inflammation, transient band keratopath

Bibliography of secondary sources on the history of dermatology III. Books, monographs, and chapters in English supplemented through 2005.

Providing supplements to the history of dermatology bibliographic record has been a continuous project for the past four decades. When the endeavor was initiated, the original authors decided that only contributions in English and those directly related to dermatology, excluding sexually transmitted diseases as such, would be indexed. There is the perennial question of whether such a manually created bibiliographic project has a need. The obvious answer remains yes. While Index Medicus has expanded the number of journals that are indexed, the number of dermatology publications currently included by Index Medicus is just over fifty. Granted, most of the papers of dermatologic interest are included in these journals, some contributions are to be found in non-indexed publications. In addition, many documents of an historical interest or of a biographical nature are not necessarily selected for indexing in Index Medicus. These installments are the first since 1980 for which the late John Thorne Crissey (1924-2009) has not contributed. His knowledge of the history of dermatology and his intellectual support are greatly missed

Decision‐Making About Reproductive Choices Among Individuals At‐Risk for Huntington's Disease

We explored how individuals at‐risk for HD who have or have not been tested make reproductive decisions and what factors are involved. We interviewed 21 individuals (8 with and 4 without the mutation, and 9 un‐tested) in‐depth for 2 hours each. At‐risk individuals faced a difficult series of dilemmas of whether to: get pregnant and deliver, have fetal testing, have pre‐implantation genetic diagnosis, adopt, or have no children. These individuals weighed competing desires and concerns: their own desires vs. those of spouses vs. broader moral concerns (e.g., to end the disease; and/or follow dictates against abortion) vs. perceptions of the interests of current or future offspring. Quandaries arose of how much and to whom to feel responsible. Some changed their perspectives over time (e.g., first “gambling,” then being more cautious). These data have critical implications for genetic counselors and other health care workers and future research, particularly as more genetic tests become available

Disclosures of Huntington disease risk within families: Patterns of decision‐making and implications

Patterns of disclosure of Huntington disease risk and genetic test results among family members are important, but have been underexplored. We interviewed 21 individuals in‐depth—eight mutation‐positive for HD, four mutation‐negative, and nine not tested—for 2 hr each. Within families, critical questions arose of what, when, and to whom to disclose, and what to do post‐disclosure. Interviewees wrestled with dilemmas of what to tell (e.g., suspicions vs. confirmed symptoms; initiation vs. completion of testing; partial vs. indirect information), how to disclose (e.g., planning in advance vs. “blurting out” information in arguments), and whether and how to tell extended family members. Questions arose of when to tell (i.e., to avoid disclosing “too early” or “too late”). Similarities and differences emerged related to types of relationships (e.g., parents telling offspring vs. offspring telling parents vs. siblings telling each other). Individuals often disclosed because of perceived duty to foster the health of their family members, enabling these others to pursue appropriate medical evaluation, if desired. Yet tensions arose because the information could burden these members, who also have rights to remain “in denial” if they wish and not discuss the topic or pursue testing. Post‐disclosure, dilemmas emerged of whether and how much to encourage family members to pursue testing. These data shed important light on critical issues that have received little, if any, attention concerning what, how, and when disclosure occurs, and have key implications for at‐risk individuals, genetic counselors, and other health care workers (HCWs), and for future research. At‐risk individuals would benefit from considering these issues in advance. HCWs need to realize that these decisions are multi‐faceted. Future research can explore whether, when, how, and how often HCWs raise these issues with individuals

Bibliography of Secondary Sources on the History of Dermatology II. Obituaries and Biographies in English before 1973

Bibliography of Secondary Sources on the History of Dermatology II. Obituaries and Biographies in English before 197

A summary of water-quality and salt marsh monitoring, Humboldt Bay, California

This report summarizes data-collection activities associated with the U.S. Geological Survey Humboldt Bay Water-Quality and Salt Marsh Monitoring Project. This work was undertaken to gain a comprehensive understanding ofwater-quality conditions, salt marsh accretion processes, marsh-edge erosion, and soil-carbon storage in Humboldt Bay, California. Multiparameter sondes recorded water temperature, specific conductance, and turbidity at a 15-minute timestep at two U.S. Geological Survey water-quality stations: Mad River Slough near Arcata, California (U.S. Geological Survey station 405219124085601) and (2) Hookton Slough near Loleta, California (U.S. Geological Survey station 404038124131801). At each station, discrete water samples were collected to develop surrogate regression models that were used to compute a continuous time seriesof suspended-sediment concentration from continuously measured turbidity. Data loggers recorded water depth at a 6-minute timestep in the primary tidal channels (Mad River Slough and Hookton Slough) in two adjacent marshes (Mad River marsh and Hookton marsh). The marsh monitoring network included five study marshes. Three marshes (Mad River, Manila, and Jacoby) are in the northern embayment of Humboldt Bay and two marshes (White and Hookton) are in the southern embayment. Surface deposition and elevation change were measured using deep rod surface elevation tables and feldspar marker horizons. Sediment characteristics and soil-carbon storage were measured using a total of 10 shallow cores, distributed across 5 study marshes, collected using an Eijkelkamp peat sampler. Rates of marsh edge erosion (2010–19) were quantified in four marshes (Mad River, Manila, Jacoby, and White) by estimating changes in the areal extent of the vegetated marsh plain using repeat aerial imagery and light detection and ranging (LiDAR)-derived elevation data. During the monitoring period (2016–19), the mean suspended-sediment concentration computed for Hookton Slough (50±20 milligrams per liter [mg/L]) was higher than Mad River Slough (18±7 mg/L). Uncertainty in mean suspended-sediment concentration values is reported using a 90-percent confidence interval. Across the five study marshes, elevation change (+1.8±0.6 millimeters per year[mm/yr]) and surface deposition (+2.5±0.5 mm/yr) were lower than published values of local sea-level rise (4.9±0.8 mm/yr), and mean carbon density was 0.029±0.005 grams of carbon per cubic centimeter. From 2010 to 2019, marsh edge erosion and soil carbon loss were greatest in low-elevation marshes with the marsh edge characterized by a gentle transition from mudflat to vegetated marsh (herein, ramped edge morphology) and larger wind-wave exposure. Jacoby Creek marsh experienced the greatest edge erosion. In total, marsh edge erosion was responsible for 62.3 metric tons of estuarine soil carbon storage loss across four study marshes. Salt marshes are an important component of coastal carbon, which is frequently referred to as “blue carbon.” The monitoring data presented in this report provide fundamental information needed to manage blue carbon stocks, assess marsh vulnerability, inform sea-level rise adaptation planning, and build coastal resiliency to climate change

New Local, National and Regional Cereal Price Indices for Improved Identification of Food Insecurity

Large price increases over a short time period can be indicative of a deteriorating food security situation. Food price indices developed by the United Nations Food and Agriculture Organization (FAO) are used to monitor food price trends at a global level, but largely reflect supply and demand conditions in export markets. However, reporting by the United States Agency for International Development (USAID)'s Famine Early Warning Systems Network (FEWS NET) indicates that staple cereal prices in many markets of the developing world, especially in surplus-producing areas, often have a delayed and variable response to international export market price trends. Here we present new price indices compiled for improved food security monitoring and assessment, and specifically for monitoring conditions of food access across diverse food insecure regions. We found that cereal price indices constructed using market prices within a food insecure region showed significant differences from the international cereals price, and had a variable price dispersion across markets within each marketshed. Using satellite-derived remote sensing information that estimates local production and the FAO Cereals Index as predictors, we were able to forecast movements of the local or national price indices in the remote, arid and semi-arid countries of the 38 countries examined. This work supports the need for improved decision-making about targeted aid and humanitarian relief, by providing earlier early warning of food security crises