78 research outputs found

    Centers for Oceans and Human Health : a unified approach to the challenge of harmful algal blooms

    Get PDF
    © 2008 Author et al. This is an open access article distributed under the terms of the Creative Commons Attribution License The definitive version was published in Environmental Health 7 (2008): S2, doi:10.1186/1476-069X-7-S2-S2.Harmful algal blooms (HABs) are one focus of the national research initiatives on Oceans and Human Health (OHH) at NIEHS, NOAA and NSF. All of the OHH Centers, from the east coast to Hawaii, include one or more research projects devoted to studying HAB problems and their relationship to human health. The research shares common goals for understanding, monitoring and predicting HAB events to protect and improve human health: understanding the basic biology of the organisms; identifying how chemistry, hydrography and genetic diversity influence blooms; developing analytical methods and sensors for cells and toxins; understanding health effects of toxin exposure; and developing conceptual, empirical and numerical models of bloom dynamics. In the past several years, there has been significant progress toward all of the common goals. Several studies have elucidated the effects of environmental conditions and genetic heterogeneity on bloom dynamics. New methods have been developed or implemented for the detection of HAB cells and toxins, including genetic assays for Pseudo-nitzschia and Microcystis, and a biosensor for domoic acid. There have been advances in predictive models of blooms, most notably for the toxic dinoflagellates Alexandrium and Karenia. Other work is focused on the future, studying the ways in which climate change may affect HAB incidence, and assessing the threat from emerging HABs and toxins, such as the cyanobacterial neurotoxin β-N-methylamino-L-alanine. Along the way, many challenges have been encountered that are common to the OHH Centers and also echo those of the wider HAB community. Long-term field data and basic biological information are needed to develop accurate models. Sensor development is hindered by the lack of simple and rapid assays for algal cells and especially toxins. It is also critical to adequately understand the human health effects of HAB toxins. Currently, we understand best the effects of acute toxicity, but almost nothing is known about the effects of chronic, subacute toxin exposure. The OHH initiatives have brought scientists together to work collectively on HAB issues, within and across regions. The successes that have been achieved highlight the value of collaboration and cooperation across disciplines, if we are to continue to advance our understanding of HABs and their relationship to human health.This work was funded through grants from the NSF/NIEHS Centers for Oceans and Human Health, NIEHS P50 ES012742 and NSF OCE-043072 (DLE and DMA), NSF OCE04-32479 and NIEHS P50 ES012740 (PB and RRB), NSF OCE-0432368 and NIEHS P50 ES12736 (LEB), NIEHS P50 ES012762 and NSF OCE-0434087 (RCS, KAL, MSP, MLW, and KAH). Additional support was provided by the ECOHAB Grant program NSF Grant OCE-9808173 and NOAA Grant NA96OP0099 (DMA), NOAA OHHI NA04OAR4600206 (RRB) and Washington State Sea Grant NA16RG1044 (RCS). KAL and VLT were supported in part by the West Coast Center for Oceans and Human Health (WCCOHH) as part of the NOAA Oceans and Human Health Initiative

    $1.25 Trillion is Still Real Money: Some Facts About the Effects of the Federal Reserve’s Mortgage Market Investments

    Full text link
    This paper measures the effects on the primary U.S. mortgage market of the large-scale asset purchase (LSAP) program in which the Federal Reserve bought $1.25 trillion of mortgagebacked securities in 2009 and 2010. We use an event-study approach and measure the movements in both prices and quantities around the initial announcement of the LSAP and subsequent changes to the program. We use a new dataset to document the changes in the menu of rates and points offered to borrowers and show that there was wide dispersion in the rate changes generated by the announcement of the LSAP program, with some borrowers seeing immediate rate reductions of up to 40 basis points and other borrowers confronting rate increases. We show that the LSAP program led to a substantial boost in market activity, with discontinuous increases in searches, applications and originations for refinance mortgages, but not purchase mortgages. Finally, we show that more creditworthy borrowers were significantly more likely to benefit from the improved credit availability

    State of the climate in 2018

    Get PDF
    In 2018, the dominant greenhouse gases released into Earth’s atmosphere—carbon dioxide, methane, and nitrous oxide—continued their increase. The annual global average carbon dioxide concentration at Earth’s surface was 407.4 ± 0.1 ppm, the highest in the modern instrumental record and in ice core records dating back 800 000 years. Combined, greenhouse gases and several halogenated gases contribute just over 3 W m−2 to radiative forcing and represent a nearly 43% increase since 1990. Carbon dioxide is responsible for about 65% of this radiative forcing. With a weak La Niña in early 2018 transitioning to a weak El Niño by the year’s end, the global surface (land and ocean) temperature was the fourth highest on record, with only 2015 through 2017 being warmer. Several European countries reported record high annual temperatures. There were also more high, and fewer low, temperature extremes than in nearly all of the 68-year extremes record. Madagascar recorded a record daily temperature of 40.5°C in Morondava in March, while South Korea set its record high of 41.0°C in August in Hongcheon. Nawabshah, Pakistan, recorded its highest temperature of 50.2°C, which may be a new daily world record for April. Globally, the annual lower troposphere temperature was third to seventh highest, depending on the dataset analyzed. The lower stratospheric temperature was approximately fifth lowest. The 2018 Arctic land surface temperature was 1.2°C above the 1981–2010 average, tying for third highest in the 118-year record, following 2016 and 2017. June’s Arctic snow cover extent was almost half of what it was 35 years ago. Across Greenland, however, regional summer temperatures were generally below or near average. Additionally, a satellite survey of 47 glaciers in Greenland indicated a net increase in area for the first time since records began in 1999. Increasing permafrost temperatures were reported at most observation sites in the Arctic, with the overall increase of 0.1°–0.2°C between 2017 and 2018 being comparable to the highest rate of warming ever observed in the region. On 17 March, Arctic sea ice extent marked the second smallest annual maximum in the 38-year record, larger than only 2017. The minimum extent in 2018 was reached on 19 September and again on 23 September, tying 2008 and 2010 for the sixth lowest extent on record. The 23 September date tied 1997 as the latest sea ice minimum date on record. First-year ice now dominates the ice cover, comprising 77% of the March 2018 ice pack compared to 55% during the 1980s. Because thinner, younger ice is more vulnerable to melting out in summer, this shift in sea ice age has contributed to the decreasing trend in minimum ice extent. Regionally, Bering Sea ice extent was at record lows for almost the entire 2017/18 ice season. For the Antarctic continent as a whole, 2018 was warmer than average. On the highest points of the Antarctic Plateau, the automatic weather station Relay (74°S) broke or tied six monthly temperature records throughout the year, with August breaking its record by nearly 8°C. However, cool conditions in the western Bellingshausen Sea and Amundsen Sea sector contributed to a low melt season overall for 2017/18. High SSTs contributed to low summer sea ice extent in the Ross and Weddell Seas in 2018, underpinning the second lowest Antarctic summer minimum sea ice extent on record. Despite conducive conditions for its formation, the ozone hole at its maximum extent in September was near the 2000–18 mean, likely due to an ongoing slow decline in stratospheric chlorine monoxide concentration. Across the oceans, globally averaged SST decreased slightly since the record El Niño year of 2016 but was still far above the climatological mean. On average, SST is increasing at a rate of 0.10° ± 0.01°C decade−1 since 1950. The warming appeared largest in the tropical Indian Ocean and smallest in the North Pacific. The deeper ocean continues to warm year after year. For the seventh consecutive year, global annual mean sea level became the highest in the 26-year record, rising to 81 mm above the 1993 average. As anticipated in a warming climate, the hydrological cycle over the ocean is accelerating: dry regions are becoming drier and wet regions rainier. Closer to the equator, 95 named tropical storms were observed during 2018, well above the 1981–2010 average of 82. Eleven tropical cyclones reached Saffir–Simpson scale Category 5 intensity. North Atlantic Major Hurricane Michael’s landfall intensity of 140 kt was the fourth strongest for any continental U.S. hurricane landfall in the 168-year record. Michael caused more than 30 fatalities and 25billion(U.S.dollars)indamages.InthewesternNorthPacific,SuperTyphoonMangkhutledto160fatalitiesand25 billion (U.S. dollars) in damages. In the western North Pacific, Super Typhoon Mangkhut led to 160 fatalities and 6 billion (U.S. dollars) in damages across the Philippines, Hong Kong, Macau, mainland China, Guam, and the Northern Mariana Islands. Tropical Storm Son-Tinh was responsible for 170 fatalities in Vietnam and Laos. Nearly all the islands of Micronesia experienced at least moderate impacts from various tropical cyclones. Across land, many areas around the globe received copious precipitation, notable at different time scales. Rodrigues and Réunion Island near southern Africa each reported their third wettest year on record. In Hawaii, 1262 mm precipitation at Waipā Gardens (Kauai) on 14–15 April set a new U.S. record for 24-h precipitation. In Brazil, the city of Belo Horizonte received nearly 75 mm of rain in just 20 minutes, nearly half its monthly average. Globally, fire activity during 2018 was the lowest since the start of the record in 1997, with a combined burned area of about 500 million hectares. This reinforced the long-term downward trend in fire emissions driven by changes in land use in frequently burning savannas. However, wildfires burned 3.5 million hectares across the United States, well above the 2000–10 average of 2.7 million hectares. Combined, U.S. wildfire damages for the 2017 and 2018 wildfire seasons exceeded $40 billion (U.S. dollars)

    Finishing the euchromatic sequence of the human genome

    Get PDF
    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    A Severity Scale for Diabetic Macular Edema Developed from ETDRS Data

    No full text
    PURPOSE. To develop a severity scale for diabetic macular edema (DME) and to assess relationships between severity and duration of DME and visual acuity (VA). METHODS. From the Early Treatment Diabetic Retinopathy Study (ETDRS), mean baseline VA scores were tabulated for 7422 eyes cross-classified by (1) location of retinal thickening (RT) and its area within 1 disc diameter of the macular center, and (2) degree of RT at the center. Adjacent (row, column, and off-diagonal) cells with the greatest similarity in baseline VA (mean and SD) based on a Gaussian (normal) likelihood were merged. An initial eight-step scale was chosen using the Schwarz criterion (Bayesian information criterion; BIC) and was revised based on clinical judgment to nine steps. Relationships between baseline VA and other photographic and fluorescein angiographic characteristics were examined singly and in combination with the scale. RESULTS. Modeling baseline VA as a function of the nine-step scale yielded an R 2 of 38.0%, compared with 38.4% using the full cross-classification of these variables. Addition of each of the other baseline characteristics changed the adjusted R 2 for the combination very little. Between scale levels 1A and 5B mean (SD) VA decreased from 86.8 (5.8) letters to 59.8 (13.6) letters. In a model of change in VA as a function of time spent at each DME severity level, VA loss increased progressively from 1 letter per year at level 2 to 17 letters per year at level 5B. CONCLUSIONS. The scale facilitates documentation of the relationship of severity and duration of DME with VA. (Invest Ophthalmol Vis Sci. 2008;49:5041-5047) DOI:10.1167/iovs.08-2231 I n its initial report, the Early Treatment Diabetic Retinopathy Study (ETDRS) demonstrated that focal/grid photocoagulation treatment of diabetic macular edema (DME) reduces the 3-year risk of moderate visual loss (MVL, a decrease in visual acuity [VA] score of 15 or more letters, corresponding to a doubling of the visual angle) by approximately 50%, from 24% in untreated eyes to 12% in treated eyes. 1 In previous ETDRS reports, the principal measure of the morphologic severity of DME has been the presence or absence of "clinically significant macular edema" (CSME), which may be characterized as retinal thickening (RT) or adjacent hard exudate that involves or threatens the center of the macula. 1 CSME may be expanded to a three-step scale by subdividing the CSME-present category by the absence or presence of involvement of the macular center. On this scale, in untreated eyes with DME the 3-year risks of MVL were 17%, 22%, and 33%, respectively, in eyes with non-CSME, CSME without center involvement, and CSME with center involvement. 2 The ETDRS also reported several factors associated with baseline VA, the most notable of which were area of RT, degree of RT at the macular center, and severity of fluorescein leakage within 1 disc diameter (DD) of the macular center. In a subset of 741 eyes with mild to moderate nonproliferative retinopathy and macular edema questionably or definitely involving the macular center, VA score at baseline was Ն70 letters (corresponding to 20/40 or better) in 92.5% of eyes in which the area of RT within 1 DD of center was Ͻ0.5 disc area (DA) versus 43.4% of eyes in which this area was Ն2.0 DA. Corresponding proportions for eyes in the lowest and highest categories of fluorescein leakage were 85.2% and 50.0% and for degree of RT at the macular center, they were 91.3% and 63.4%. 3 The objectives of this report are to describe the development of a more detailed scale to categorize the severity of DME and to use the scale to assess the relationship between the duration of severe DME and VA. The scale is based on associations between baseline gradings of features characteristic of DME in stereoscopic color fundus photographs and best corrected baseline VA. 4,5 METHODS Baseline VA scores (mean and SD) were tabulated for eyes crossclassified by degree of RT at the macular center and by a combination of location of RT within a 30°photographic field centered on the macula (Field 2) and area of RT within 1 DD of the center. Relationships between baseline VA and other ocular characteristics included in the baseline gradings of fundus photographs and fluorescein angiograms were also examined singly and in combination with From the Departments o

    Estrogen replacement therapy and retinal vascular caliber

    No full text
    Objective: It is unclear if estrogen replacement therapy (ERT) has an effect on the retinal circulation. In the current study, we examine the association of ERT, female reproductive factors, and retinal vascular caliber. Design: Population-based cross-sectional study. Participants: Women participants aged 43 to 84 years living in Beaver Dam, Wisconsin. Methods: Retinal photographs of participants taken at the baseline examination were digitized, and the diameters of arterioles and venules were measured using a well-established technique. Estrogen replacement therapy and female reproductive factors were ascertained by interview. Main Outcome Measures: Retinal arteriolar and venular diameters. Results: Of the 2469 women participants with data for analysis, 10.5% were current users of ERT and 7.4% were past users. After adjusting for age, blood pressure (BP), body mass index, smoking, and other factors, women who were current users of ERT had narrower retinal arteriolar and venular diameters than those who were past users or never used, with mean arteriolar diameters of 167.6 µm for current users, 170.8 µm for past users, and 170.9 µm for those who never used (P = 0.009) and mean venular diameters of 239.9 µm for current users, 244.0 µm for past users, and 243.9 µm for those who never used (P = 0.02). There was a significant trend of increasing narrowing for both arterioles (P trend, 0.01) and venules (P trend, 0.007) with increasing duration of ERT. Associations were somewhat stronger in younger women and women without a history of hypertension and cigarette smoking. Female reproductive factors (e.g., age of menarche and pregnancy) were not associated with retinal vessel diameters. Conclusions: Estrogen replacement therapy is associated with narrower retinal vessel diameters, independent of BP and other vascular factors

    Prospective cohort study of retinal vessel diameters and risk of hypertension

    No full text
    Objective To examine the relation between diameters of the retinal arterioles and 10 year incidence of hypertension. Design Population based prospective cohort study. Setting Beaver Dam eye study. Participants 2451 normotensive people aged 43 to 84 years. Main outcome measures Diameters of retinal arterioles and venules measured from digitised photographs of the retina taken at baseline. Measurements summarised as the arteriole:venule ratio, with a lower ratio indicating smaller arteriolar diameters. Incident hypertension, defined as systolic blood pressure ≥140 mm Hg, diastolic blood pressure ≥90 mm Hg, or use of antihypertensive drugs during follow up. Results 721 participants developed hypertension over a 10 year period. Those with lower arteriole:venule ratio had a higher cumulative incidence of hypertension (incidences of 17.4%, 24.1%, 31.0%, and 45.1%, respectively, for decreasing quarters of distribution of arteriole:venule ratio). After adjustment for age and sex, participants with arteriole:venule ratios in the lowest quarter had a threefold higher risk of hypertension (odds ratio 2.95, 95% confidence interval 2.77 to 3.88) than those with ratios in the highest quarter. This association remained significant after further adjustment for baseline systolic and diastolic blood pressure and other risk factors (1.82, 1.39 to 2.40, for lowest versus highest ratio quarters). Conclusions Narrowed retinal arterioles are associated with long term risk of hypertension, suggesting that structural alterations of the microvasculature may be linked to the development of hypertension

    Retinal arteriolar narrowing and risk of coronary heart disease in men and women: The Atherosclerosis Risk in Communities Study

    No full text
    Context: Microvascular processes have been hypothesized to play a greater role in the development of coronary heart disease (CHD) in women than in men; however, prospective clinical data are limited. Objective: To examine the association between retinal arteriolar narrowing, a marker of microvascular damage from hypertension and inflammation, and incident CHD in healthy middle-aged women and men. Design, Setting, and Participants: The Atherosclerosis Risk in Communities Study, an ongoing prospective, population-based cohort study in 4 US communities initiated in 1987-1989. Retinal photographs were taken in 9648 women and men aged 51 to 72 years without CHD at the third examination (1993-1995). To quantify retinal arteriolar narrowing, the photographs were digitized, individual arteriolar and venular diameters were measured, and a summary arteriole-to-venule ratio (AVR) was calculated. Main Outcome Measure: Risk of CHD associated with retinal arteriolar narrowing. Results: During an average 3.5 years of follow-up, 84 women and 187 men experienced incident CHD events. In women, after controlling for mean arterial blood pressure averaged over the previous 6 years, diabetes, cigarette smoking, plasma lipid levels, and other risk factors, each SD decrease in the AVR was associated with an increased risk of any incident CHD (relative risk [RR], 1.37; 95% confidence interval [Cl], 1.08-1.72) and of acute myocardial infarction (RR, 1.50; 95% Cl, 1.10-2.04). In contrast, AVR was unrelated to any incident CHD in men (RR, 1.00; 95% Cl, 0.84-1.18) or to acute myocardial infarction (RR, 1.08; 95% Cl, 0.85-1.38). Conclusion: Retinal arteriolar narrowing is related to risk of CHD in women but not in men, supporting a more prominent microvascular role in the development of CHD in women than in men. Future work is needed to confirm these findings
    corecore