Spatial patterns of watershed impervious cover relativeto stream location

The urban stream syndrome may not be limited to streams in urbanized watersheds. We measured thespatial pattern of impervious cover in ∼82,800 small watersheds across the conterminous United Statesby comparing watershed-based and stream-based measures of imperviousness. The watershed-basedmeasure was the commonly used watershed percentage impervious cover. The stream-based measurewas the percentage of watershed stream length flowing through impervious cover. Spatial pattern ofimpervious cover was classified on a watershed basis as proximal to streams, distal to streams, and uni-form by comparing the two measures of impervious cover. We used a classification threshold of ±5%to assign watersheds to the three classes (i.e., stream-based minus watershed-based ≥5% = proximal;watershed-based minus stream-based ≥5% = distal; else = uniform). We then applied the classification totwo impervious cover thresholds, ≥5% and ≥15%. For ≥5% and ≥15% thresholds, impervious cover wasdistributed uniformly across ∼70% and ∼86% of the watersheds, respectively. For the remaining water-sheds, the proximal spatial pattern was ∼12x and ∼4x greater than the distal spatial pattern for the ≥5%and ≥15% impervious cover thresholds, respectively. The proximal spatial pattern of impervious coveroccurred predominantly in non-urbanized watersheds, resulting in a widespread occurrence of a rela-tively high percentage of streams flowing through relatively high impervious cover in watersheds wherethe total percentage impervious cover was relatively low. The spatial pattern of change in imperviouscover between ca. 2001 and ca. 2006 did not avoid streams. Impervious cover increased in the vicinitystreams in ∼55% of the watersheds with increases in impervious cover. During this period, the lengthof streams flowing through ≥5% and ≥15% impervious cover increased by ∼9800 km and ∼6900 km,respectively

Spatial patterns of watershed impervious cover relativeto stream location

The urban stream syndrome may not be limited to streams in urbanized watersheds. We measured thespatial pattern of impervious cover in ∼82,800 small watersheds across the conterminous United Statesby comparing watershed-based and stream-based measures of imperviousness. The watershed-basedmeasure was the commonly used watershed percentage impervious cover. The stream-based measurewas the percentage of watershed stream length flowing through impervious cover. Spatial pattern ofimpervious cover was classified on a watershed basis as proximal to streams, distal to streams, and uni-form by comparing the two measures of impervious cover. We used a classification threshold of ±5%to assign watersheds to the three classes (i.e., stream-based minus watershed-based ≥5% = proximal;watershed-based minus stream-based ≥5% = distal; else = uniform). We then applied the classification totwo impervious cover thresholds, ≥5% and ≥15%. For ≥5% and ≥15% thresholds, impervious cover wasdistributed uniformly across ∼70% and ∼86% of the watersheds, respectively. For the remaining water-sheds, the proximal spatial pattern was ∼12x and ∼4x greater than the distal spatial pattern for the ≥5%and ≥15% impervious cover thresholds, respectively. The proximal spatial pattern of impervious coveroccurred predominantly in non-urbanized watersheds, resulting in a widespread occurrence of a rela-tively high percentage of streams flowing through relatively high impervious cover in watersheds wherethe total percentage impervious cover was relatively low. The spatial pattern of change in imperviouscover between ca. 2001 and ca. 2006 did not avoid streams. Impervious cover increased in the vicinitystreams in ∼55% of the watersheds with increases in impervious cover. During this period, the lengthof streams flowing through ≥5% and ≥15% impervious cover increased by ∼9800 km and ∼6900 km,respectively

Exo-π-bonding to an ortho-carborane hypercarbon atom: systematic icosahedral cage distortions reflected in the structures of the fluoro-, hydroxy- and amino-carboranes, 1-X-2-Ph-1,2-C2B10H10 (X = F, OH or NH2) and related anions

The structures of derivatives of phenyl-ortho-carborane bearing on the second cage hypercarbon atom a pi-donor substituent (F, OH, O-, NH2, NH- and CH2-) were investigated by NMR, X-ray crystallography and computational studies. The molecular structures of these compounds, notably their cage C1-C2 distances and the orientations of their pi-donor substituents (OH, NH2, NH- and CH2-) show remarkable and systematic variations with the degree of exo pi-bonding, which varies as expected with the pi-donor characteristics of the substituent

Vibrio parahaemolyticus, enterotoxigenic Escherichia coli, enterohemorrhagic Escherichia coli and Vibrio cholerae

This review highlighted the following: (i) pathogenic mechanism of the thermostable direct hemolysin produced by Vibrio parahaemolyticus, especially on its cardiotoxicity, (ii) heat-labile and heat-stable enterotoxins produced by enterotoxigenic Escherichia coli, especially structure–activity relationship of heat-stable enterotoxin, (iii) RNA N-glycosidase activity of Vero toxins (VT1 and VT2) produced by enterohemorrhagic Escherichia coli O157:H7, (iv) discovery of Vibrio cholerae O139, (v) isolation of new variant of Vibrio cholerae O1 El Tor that carries classical ctxB, and production of high concentration of cholera toxin by these strains, and (vi) conversion of viable but nonculturable (VBNC) Vibrio cholerae to culturable state by co-culture with eukaryotic cells

Search for gravitational-wave transients associated with magnetar bursts in advanced LIGO and advanced Virgo data from the third observing run

Gravitational waves are expected to be produced from neutron star oscillations associated with magnetar giant f lares and short bursts. We present the results of a search for short-duration (milliseconds to seconds) and longduration (∼100 s) transient gravitational waves from 13 magnetar short bursts observed during Advanced LIGO, Advanced Virgo, and KAGRA’s third observation run. These 13 bursts come from two magnetars, SGR1935 +2154 and SwiftJ1818.0−1607. We also include three other electromagnetic burst events detected by FermiGBM which were identified as likely coming from one or more magnetars, but they have no association with a known magnetar. No magnetar giant flares were detected during the analysis period. We find no evidence of gravitational waves associated with any of these 16 bursts. We place upper limits on the rms of the integrated incident gravitational-wave strain that reach 3.6 × 10−²³ Hz at 100 Hz for the short-duration search and 1.1 ×10−²² Hz at 450 Hz for the long-duration search. For a ringdown signal at 1590 Hz targeted by the short-duration search the limit is set to 2.3 × 10−²² Hz. Using the estimated distance to each magnetar, we derive upper limits upper limits on the emitted gravitational-wave energy of 1.5 × 1044 erg (1.0 × 1044 erg) for SGR 1935+2154 and 9.4 × 10^43 erg (1.3 × 1044 erg) for Swift J1818.0−1607, for the short-duration (long-duration) search. Assuming isotropic emission of electromagnetic radiation of the burst fluences, we constrain the ratio of gravitational-wave energy to electromagnetic energy for bursts from SGR 1935+2154 with the available fluence information. The lowest of these ratios is 4.5 × 103

Global Retinoblastoma Presentation and Analysis by National Income Level

Importance: Early diagnosis of retinoblastoma, the most common intraocular cancer, can save both a child's life and vision. However, anecdotal evidence suggests that many children across the world are diagnosed late. To our knowledge, the clinical presentation of retinoblastoma has never been assessed on a global scale. Objectives: To report the retinoblastoma stage at diagnosis in patients across the world during a single year, to investigate associations between clinical variables and national income level, and to investigate risk factors for advanced disease at diagnosis. Design, Setting, and Participants: A total of 278 retinoblastoma treatment centers were recruited from June 2017 through December 2018 to participate in a cross-sectional analysis of treatment-naive patients with retinoblastoma who were diagnosed in 2017. Main Outcomes and Measures: Age at presentation, proportion of familial history of retinoblastoma, and tumor stage and metastasis. Results: The cohort included 4351 new patients from 153 countries; the median age at diagnosis was 30.5 (interquartile range, 18.3-45.9) months, and 1976 patients (45.4) were female. Most patients (n = 3685 84.7%) were from low-and middle-income countries (LMICs). Globally, the most common indication for referral was leukocoria (n = 2638 62.8%), followed by strabismus (n = 429 10.2%) and proptosis (n = 309 7.4%). Patients from high-income countries (HICs) were diagnosed at a median age of 14.1 months, with 656 of 666 (98.5%) patients having intraocular retinoblastoma and 2 (0.3%) having metastasis. Patients from low-income countries were diagnosed at a median age of 30.5 months, with 256 of 521 (49.1%) having extraocular retinoblastoma and 94 of 498 (18.9%) having metastasis. Lower national income level was associated with older presentation age, higher proportion of locally advanced disease and distant metastasis, and smaller proportion of familial history of retinoblastoma. Advanced disease at diagnosis was more common in LMICs even after adjusting for age (odds ratio for low-income countries vs upper-middle-income countries and HICs, 17.92 95% CI, 12.94-24.80, and for lower-middle-income countries vs upper-middle-income countries and HICs, 5.74 95% CI, 4.30-7.68). Conclusions and Relevance: This study is estimated to have included more than half of all new retinoblastoma cases worldwide in 2017. Children from LMICs, where the main global retinoblastoma burden lies, presented at an older age with more advanced disease and demonstrated a smaller proportion of familial history of retinoblastoma, likely because many do not reach a childbearing age. Given that retinoblastoma is curable, these data are concerning and mandate intervention at national and international levels. Further studies are needed to investigate factors, other than age at presentation, that may be associated with advanced disease in LMICs. © 2020 American Medical Association. All rights reserved