Publications by authors named "H G Harder"
Aircraft observations have revealed ubiquitous new particle formation in the tropical upper troposphere over the Amazon and the Atlantic and Pacific oceans. Although the vapours involved remain unknown, recent satellite observations have revealed surprisingly high night-time isoprene mixing ratios of up to 1 part per billion by volume (ppbv) in the tropical upper troposphere. Here, in experiments performed with the CERN CLOUD (Cosmics Leaving Outdoor Droplets) chamber, we report new particle formation initiated by the reaction of hydroxyl radicals with isoprene at upper-tropospheric temperatures of -30 °C and -50 °C.
View Article and Find Full Text PDFNew particle formation (NPF) in the tropical upper troposphere is a globally important source of atmospheric aerosols. It is known to occur over the Amazon basin, but the nucleation mechanism and chemical precursors have yet to be identified. Here we present comprehensive in situ aircraft measurements showing that extremely low-volatile oxidation products of isoprene, particularly certain organonitrates, drive NPF in the Amazonian upper troposphere.
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- Advances in genetic testing for breast cancer are becoming more integrated into diagnostic procedures, with new methods aimed at improving efficiency and patient experience.
- A study involving 1140 women tested the effectiveness of two methods of delivering pre-test information: digital sources and traditional genetic counseling.
- Results showed that digital information led to a higher uptake of genetic testing (90.8% vs. 84.7%) while maintaining similar levels of patient knowledge, anxiety, and satisfaction, suggesting a viable shift towards digital pathways in breast cancer care.
Article Synopsis
- Ammonia emissions in Southeast Asia significantly impact air pollution and the development of the Asian Tropopause Aerosol Layer (ATAL), particularly during summer when the South Asian monsoon is active.
- The study utilizes the EMAC chemistry-climate model to analyze how ammonia influences particle formation, revealing a tenfold increase in particle creation during the day, especially within the monsoon's upper troposphere and lower stratosphere (UTLS).
- Findings indicate that while ammonia enhances cloud condensation nuclei (CCN) concentrations and aerosol optical depth (AOD), its effect on aerosol mass in the ATAL is comparatively limited, suggesting a complex relationship between ammonia, particle growth, and aerosol composition.
Objectives: The objective was to map the experiences and needs of patients presenting with symptoms of suspected cancer in the primary care interval (from when they first present to primary care to their first appointment or referral to a secondary or tertiary level healthcare facility).
Design: This was a scoping review.
Inclusion Criteria: Studies or reports written in English which included primary data on the primary care interval experiences and/or needs of adult patients presenting with new symptoms of suspected cancer were eligible.