The effects of interactions between proline and carbon nanostructures on organocatalysis in the Hajos-Parrish-Eder-Sauer-Wiechert reaction

The non-covalent interactions of S-(-)-proline with the surfaces of carbon nanostructures (fullerene, nanotubes and graphite) change the nucleophilic-electrophilic and acid-base properties of the amino acid, thus tuning its activity and selectivity in the organocatalytic Hajos-Parrish-Eder-Sauer-Wiechert (HPESW) reaction. Whilst our spectroscopy and microscopy measurements show no permanent covalent bonding between S-(-)-proline and carbon nanostructures, a systematic investigation of the catalytic activity and selectivity of the organocatalyst in the HPESW reaction demonstrates a clear correlation between the pyramidalisation angle of carbon nanostructures and the catalytic properties of S-(-)-proline. Carbon nanostructures with larger pyramidalisation angles have a stronger interaction with the nitrogen atom lone pair of electrons of the organocatalyst, thereby simultaneously decreasing the nucleophilicity and increasing the acidity of the organocatalyst. These translate into lower conversion rates but higher selectivities towards the dehydrated product of Aldol addition

High-resolution late Holocene sedimentary cores record the long history of the city of Cádiz (south-western Spain)

Today, coastal cities worldwide are facing major changes resulting from climate change and anthropogenic forcing, which requires adaptation and mitigation strategies to be established. In this context, sedimentological archives in many Mediterranean cities record a multi-millennial history of environmental dynamics and human adaptation, revealing a long-lasting resilience. Founded by the Phoenicians around 3000 years ago, Cadiz (south-western Spain) is a key example of a coastal resilient city. This urban centre is considered to be one of the first cities of western Europe and has experienced major natural hazards during its long history, such as coastal erosion, storms, and also tsunamis (like the one in 1755 CE following the destructive Lisbon earthquake). In the framework of an international, joint archaeological and geoarchaeological project, three cores have been drilled in a marine palaeochannel that ran through the ancient city of Cadiz. These cores reveal a >= 50m thick Holocene sedimentary sequence. Importantly, most of the deposits date from the 1st millennium BCE to the 1st millennium CE. This exceptional sedimentary archive will allow our scientific team to achieve its research goals, which are (1) to reconstruct the palaeogeographical evolution of this specific coastal area; (2) to trace the intensity of activities of the city of Cadiz based on archaeological data, as well as geochemical and palaeoecological indicators; and (3) to identify and date high-energy event deposits such as storms and tsunami

Effects of controlled diesel exhaust exposure on apoptosis and proliferation markers in bronchial epithelium – an in vivo bronchoscopy study on asthmatics, rhinitics and healthy subjects

BackgroundEpidemiological evidence demonstrates that exposure to traffic-derived pollution worsens respiratory symptoms in asthmatics, but controlled human exposure studies have failed to provide a mechanism for this effect. Here we investigated whether diesel exhaust (DE) would induce apoptosis or proliferation in the bronchial epithelium in vivo and thus contribute to respiratory symptoms.MethodsModerate (n?=?16) and mild (n?=?16) asthmatics, atopic non-asthmatic controls (rhinitics) (n?=?13) and healthy controls (n?=?21) were exposed to filtered air or DE (100 ?g/m 3 ) for 2 h, on two separate occasions. Bronchial biopsies were taken 18 h post-exposure and immunohistochemically analysed for pro-apoptotic and anti-apoptotic proteins (Bad, Bak, p85 PARP, Fas, Bcl-2) and a marker of proliferation (Ki67). Positive staining was assessed within the epithelium using computerized image analysis.ResultsNo evidence of epithelial apoptosis or proliferation was observed in healthy, allergic or asthmatic airways following DE challenge.ConclusionIn the present study, we investigated whether DE exposure would affect markers of proliferation and apoptosis in the bronchial epithelium of asthmatics, rhinitics and healthy controls, providing a mechanistic basis for the reported increased airway sensitivity in asthmatics to air pollutants. In this first in vivo exposure investigation, we found no evidence of diesel exhaust-induced effects on these processes in the subject groups investigated

Trends in direct normal irradiance in Oregon: Comparison of surface measurements and ISCCP derived irradiance

Long-term pyrheliometer measurements of direct normal irradiance at three sites in Oregon are compared to irradiance calculated from data of the International Satellite Cloud Climatology Project. An increase of direct normal irradiance of up to 1 W/m2 per year between 1980 and 2004 is found in the measured data. The increase seems to be partially caused by stratospheric aerosols from two major volcano eruptions. After removing data for the years most affected by volcanic aerosol, two of the three sites still show a significant increase in direct normal irradiance, indicating other atmospheric changes may contribute to the observed trends. From 1984–2004, for which satellite data are available, both data sets correlate very well and show an increase in direct normal irradiance of 0.3 W/m2 per year on average. In both data sets trends vary seasonally. A strong increase is observed during summer and fall. At two sites a significant decrease during winter, which is consistent in measured and satellite derived values, counteracts part of the summer increase

SOLAR RESOURCE GIS DATA BASE FOR THE PACIFIC NORTHWEST USING SATELLITE DATA

A five year solar radiation database derived from satellite cloud cover and auxiliary data has been created for the Pacific Northwest. The database provides hourly global, beam, and diffuse irradiance values from 1998 through 2002 from longitude -110.05{sup o} to -125.05{sup o} and north latitude 42.05{sup o} to 49.05{sup o} on a 0.1{sup o} grid. This final report describes how the database was created, the characteristics of the database, the software tool developed to facilitate the use of the database, and dissemination of the database

Testing a Model of IR Radiative Losses Preprint Testing a model of IR radiative losses

ABSTRACT Thermopile pyranometers exhibit IR radiative losses that affect global and diffuse shortwave measurements made with first class thermopile based instruments. Pyrgeometers can be used to measure the sky temperature and are used to calculate the pyranometer's IR radiative losses. Few solar monitoring sites are equipped with pyrgeometers necessary to account for the IR radiative losses associated with the pyranometers. High quality data from the Solar Radiation Research Laboratory (SRRL) at the National Renewable Energy Laboratory are used to test and further develop a model for the IR radiative losses without the use of pyrgeometer data. The various methods for obtaining IR radiative loss values are compared and contrasted using the SRRL data. A simple scaling method is proposed and tested to adjust the non-pyrgeometer based correlation models to sites with different sky temperature characteristics

Solar and infrared radiation measurements

The rather specialized field of solar and infrared radiation measurement has become more and more important in the face of growing demands by the renewable energy and climate change research communities for data that are more accurate and have increased temporal and spatial resolution. Updating decades of acquired knowledge in the field, Solar and Infrared Radiation Measurements details the strengths and weaknesses of instruments used to conduct such solar and infrared radiation measurements. Topics covered include: Radiometer design and performance Equipment calibration, installation, operat