Variation in carbon and nitrogen concentrations among peatland categories at the global scale

Publisher Copyright: © 2022 This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.Peatlands account for 15 to 30% of the world's soil carbon (C) stock and are important controls over global nitrogen (N) cycles. However, C and N concentrations are known to vary among peatlands contributing to the uncertainty of global C inventories, but there are few global studies that relate peatland classification to peat chemistry. We analyzed 436 peat cores sampled in 24 countries across six continents and measured C, N, and organic matter (OM) content at three depths down to 70 cm. Sites were distinguished between northern (387) and tropical (49) peatlands and assigned to one of six distinct broadly recognized peatland categories that vary primarily along a pH gradient. Peat C and N concentrations, OM content, and C:N ratios differed significantly among peatland categories, but few differences in chemistry with depth were found within each category. Across all peatlands C and N concentrations in the 10-20 cm layer, were 440 ± 85.1 g kg-1 and 13.9 ± 7.4 g kg-1, with an average C:N ratio of 30.1 ± 20.8. Among peatland categories, median C concentrations were highest in bogs, poor fens and tropical swamps (446-532 g kg-1) and lowest in intermediate and extremely rich fens (375-414 g kg-1). The C:OM ratio in peat was similar across most peatland categories, except in deeper samples from ombrotrophic tropical peat swamps that were higher than other peatlands categories. Peat N concentrations and C:N ratios varied approximately two-fold among peatland categories and N concentrations tended to be higher (and C:N lower) in intermediate fens compared with other peatland types. This study reports on a unique data set and demonstrates that differences in peat C and OM concentrations among broadly classified peatland categories are predictable, which can aid future studies that use land cover assessments to refine global peatland C and N stocks.Peer reviewe

Imaging of Infertility, Part 1: Hysterosalpingograms to Magnetic Resonance Imaging

© 2019 Elsevier Inc. Infertility, or subfertility, is the inability to achieve a clinical pregnancy after a 1-year period of regular unprotected sexual intercourse in women younger than 35 and after 6 months in women older than 35. Although initial assessment involves a multitude of factors, including a detailed medical history, physical examination, semen analysis, and hormonal evaluation, diagnostic imaging of the female partner often plays an important role in establishing the etiology for infertility. This article provides an overview of the multimodality imaging assessment of female infertility and details the developmental and acquired pelvic abnormalities in which diagnostic imaging aids in evaluation

Anastomosing hemangioma of liver.

Anastomosing hemangiomas are a rare subtype of benign vascular hemangioma which most commonly arise in the genitourinary tract and retroperitoneum. In only a small number of reports has this entity been shown originating within the liver parenchyma. Despite their benign behavior, on contrast-enhanced computer tomography and magnetic resonance imaging studies anastomosing hemangiomas can demonstrate enhancement characteristics similar to primary and metastatic liver lesions. This case report highlights the imaging features of this entity and provides a brief review of the limited literature that exists on this rare hepatic lesion

PHOTO-CHEMICAL CYCLO-ADDITION OF BENZENE TO 1,3-DIOXOLES AND 1,4-DIOXENE .1. PREPARATIVE RESULTS

Mattay J, LEISMANN H, SCHARF HD. PHOTO-CHEMICAL CYCLO-ADDITION OF BENZENE TO 1,3-DIOXOLES AND 1,4-DIOXENE .1. PREPARATIVE RESULTS. Chemische Berichte. 1979;112(2):577-599