Lower atmospheric temperature profile measurements using a Raman lidar

A Raman lidar system was used to measure the temperature profile of the upper troposphere and lower stratosphere. The system consists of a tripled Nd-YAG laser and a 1.5 meter diameter telescope. Two photomultipliers are used at the output of the telescope to allow for measurements at both the laser wavelength and at the Raman shifted wavelength due to atmospheric nitrogen. The signal from the photomultipliers is recorded as photon counts in 1 microsec bins. The results of a number of laser shots are summed together to provide atmospheric returns which have acceptable signal to noise characteristics. Measurements of the Raman nitrogen return were acquired up to an altitude in excess of 20 km. Temperature profiles were retrieved from the attenuation corrected Raman nitrogen return assuming the atmosphere to be in hydrostatic equilibrium and using the ideal gas law. Retrieved temperature profiles are shown compared with independent temperature measurements

Convective structure of the planetary boundary layer of the ocean during gale

The structure of the Planetary Boundary Layer (PBL) was measured, using an airborne lidar, over the Atlantic Ocean during several intensive observation periods of the Genesis of Atlantic Lows Experiment (GALE). Primary emphasis is on the understanding of the convective structure within the PBL during cold air outbreaks. Cold outbreaks generally occur in between the development of coastal storms; and behind a cold front sweeping down from Canada out across the Atlantic. As the cold dry air moves over the relatively warm ocean, it is heated and moistened. The transfer of latent and sensible heat during these events accounts for most of the heat transfer between the ocean and atmosphere during winter. Moistening of the PBL during these eventsis believed to be an important factor in determining the strength of development of the storm system which follows. In general, the more PBL moisture available as latent heat the higher the probability the storm will intensify. The major mechanism for vertical mixing of heat and mositure within the PBL is cellular convection. Knowlede of the organization and structure of the convection is important for understanding the process

Lidar observations and modeling of cold air outbreaks during MASEX and GALE

As part of MASEX and GALE a number of research flights were carried out over the Marine Boundary Layer (MBL) during periods when extremely cold and dry continental air was flowing out over the warm coastal waters at the east coast of the U.S. Such periods, which are named cold air outbreaks are characterized by massive warming and moistening of the MBL resulting in rapid entrainment conditions. As the MBL deepens as a function of fetch over the ocean, clouds develop. The line of cloud formation typically follows the coast line closely as has been observed many times from satellite imagery. The backscatter data from the NASA Goddard airborne lidar, which was used to measure the depth of the MBL in great detail, is ideally suited to verify parametrized models of boundary layer growth rate. The data indicates that the deepening MBL gradually develops clouds at its top. Those clouds form an integral part of the MBL and exercise an important influence on the energy cycle within the MBL. It is suggested that the rapid entrainment observed during overcast conditions represent an increase in efficiency of conversion of available turbulence kinetic energy into entrainment energy

The role of water vapor in climate. A strategic research plan for the proposed GEWEX water vapor project (GVaP)

The proposed GEWEX Water Vapor Project (GVaP) addresses fundamental deficiencies in the present understanding of moist atmospheric processes and the role of water vapor in the global hydrologic cycle and climate. Inadequate knowledge of the distribution of atmospheric water vapor and its transport is a major impediment to progress in achieving a fuller understanding of various hydrologic processes and a capability for reliable assessment of potential climatic change on global and regional scales. GVap will promote significant improvements in knowledge of atmospheric water vapor and moist processes as well as in present capabilities to model these processes on global and regional scales. GVaP complements a number of ongoing and planned programs focused on various aspects of the hydrologic cycle. The goal of GVaP is to improve understanding of the role of water vapor in meteorological, hydrological, and climatological processes through improved knowledge of water vapor and its variability on all scales. A detailed description of the GVaP is presented

Genesis of Atlantic Lows Experiment NASA Electra Boundary Layer Flights Data Report

The objective of this research was to obtain high resolution measurements of the height of the Marine Atmospheric Boundary Layer (MABL) during cold air outbreaks using an Airborne Lidar System. The research was coordinated with other investigators participating in the Genesis of Atlantic Lows Experiment (GALE). An objective computerized scheme was developed to obtain the Boundary Layer Height from the Lidar Data. The algorithm was used on each of the four flight days producing a high resolution data set of the MABL height over the GALE experiment area. Plots of the retrieved MABL height as well as tabular data summaries are presented

Raman backscatter of laser radiation in the earth's atmosphere

Laser optical radar measurement of atmospheric Raman backscattering by nitrogen, oxygen, and water vapo

Improvements in Techniques for Aging Mammals by Dental Cementum Annuli

Several modifications of commonly used histological techniques for the preparation of dental tissues for aging by dental cementum annuli are presented. Improvements in methods of tissue collection, preservation, decalcification, sectioning, and staining permit faster preparation of tissues and produce higher-quality, easily interpreted sections. Possible application of hard-tissue microtomes to sectioning of undecalcified or partially decalcified tissues is also discussed

NEW SIGNALING PATHWAYS REGULATING SCHWANN CELLS OF THE PERIPHERAL NERVOUS SYSTEM: IMPLICATIONS IN PERIPHERAL NEUROPATHIES.

The origin, development and maturation of Schwann cells (SCs), the main glial cells of the peripheral nervous system (PNS), are a set of complicated and intriguing processes. These multifactorial processes take place following a precise and unique coordination between different molecules and intracellular signaling, that interact with a complex of endogenous and exogenous signals. Among these, there are integrins, neuregulins, growth factors, hormones, neurotransmitters and intracellular pathway, including protein kinase A and protein kinase C (PKA and PKC), serine/threonine kinase 1 (AKT), extracellular regulated MAPK/mitogen-activated protein kinase 1 (ERK/MAPK), Hippo, mechanistic target of rapamycin (mTOR), etc. This thesis is focused on some novel intracellular signaling pathways involved in the SCs development and maturation, from their origin to the acquisition of the myelinating or repairing phenotype. The first part of the thesis focuses on a proto-oncogene, the non-receptor tyrosine kinase SRC (SRC), and the focal adhesion kinase (FAK), which are intermediate pathways known to play a role in the control of adhesion, motility, and migration of SCs. It has been investigated whether these pathways are regulated by allopregnanolone (ALLO), a neuroactive steroid of peculiar interest for the control of SCs maturation. The second part of this thesis focuses on the study of the Hippo signaling pathway, known to be a key regulator of proliferation, apoptosis, control of organ size and crucial for cancer proliferation. Hippo pathway has been studied in SCs, where it is linked to Merlin (an oncosuppressor protein) and Yes associated protein/tafazzin (YAP/TAZ) factors. Interestingly, these mechanisms were responsive to physical and environmental challenges. Lastly, the third part of this thesis move on studying the role of the g\uf067-aminobutyric acid (GABA) system in the control of peripheral myelination. In particular, the whole expression profile was investigated in conditional knock out mice for the B1 subunit of the GABA-B receptor (GABA-B R), with a specific deletion in SCs. By the use of microarray technology, several genes resulted up- or downregulated in SCs, opening new perspectives on the possible targets downstream GABA-B R in SCs. Overall, these results highlight new aspects of the SCs biology, shedding light on unraveled mechanisms and underlying their importance in the development and maturation of these specialized cells of the PNS. This may be of pharmacological and therapeutically interest, in order to identify reliable approaches for the treatment of PNS diseases

Performance modeling of ultraviolet Raman lidar systems for daytime profiling of atmospheric water vapor

We describe preliminary results from a comprehensive computer model developed to guide optimization of a Raman lidar system for measuring daytime profiles of atmospheric water vapor, emphasizing an ultraviolet, solar-blind approach

The Sector Analysis as a Coastal Management Tool for Sustainable Tourism Development on the Mediterranean Coast of Morocco

Beaches are ecologically valuable ecosystems and sites that attract many tourists from all over the world, therefore, knowledge of their environmental conditions to establish sound management strategies is of extreme relevance. This study aims to assess and classify 50 beaches through an innovative coastal management approach called “Sector Analysis”, which integrates Litter grading, the coastal scenic quality and beach typology in order to classify sites into one of three sectors: Green (high value sites), Red (low value sites) and Yellow (sites with contradictory values). Litter Grade makes it possible to classify a site according to the quantity of litter using four grades from “A” (low) to “D” (high amount). The Coastal Scenic Evaluation System (CSES) allows to classify sites into five classes, ranging from extremely attractive natural sites (Class I) to unattractive degraded and urbanized sites (Class V). This innovative methodology for sustainable coastal area management can be easily applied to any beach in the world. The results on Litter Grade and CSES considered in this paper were obtained from previous studies and used to obtain the Sector Analysis that showed only 8 sites (16%) are in the Green sector, 18 sites (36%) in the Red sector and 24 sites (48%) in the Yellow sector. The significant percentage of sites in the Red sector (one third of the sites studied) clearly indicates the degradation that the Moroccan Mediterranean coast has undergone due to considerable anthropogenic activities and the lack of adequate coastal management programs. In this study, various management interventions were proposed to conserve and improve the aesthetic quality of beaches and reduce the impact and presence of litter in the coastal areas