Morphologically-directed Raman spectroscopy (MDRS) is a novel yet reliable analytical technique that can be used for a variety of forensic applications, enabling scientists to gain more information from samples than they obtain using more traditional methods. In soil forensics, MDRS delivers particle size distribution and microscopic morphological characteristics for the particles present, and at the same time allows secure mineral identification. In this article, we explore the benefits of utilizing soil in forensic investigations, and demonstrate the value of applying MDRS. Two case studies illustrate the real-life potential and applications of this technology.
Phytoplankton collected bimonthly by net during 1991-2 from the Sontecomapan lagoon (12 km long and 1"5 km wide), in the Gulf of Mexico, included four species and several forms of the diatom genus Ske]etonema. The spatial and temporal distribution of Skeletonema subsalsum, S. pseudocostatum and S. costatum in the lagoon varied with the salinity. S. subsa]sum was dominant in the rainy season (JulyFebruary), when salinity was 0-6 ppt. S. costatum was abundant in the adjacent marine zone, occasionally with S. tropicum, and occurred in the lagoon during the dry season (March) at salinities of 3"2-37"0 ppt. S. pseudocostatum was present the whole year showing a preference for brackish conditions (4-25 ppt). Morphological variation in three species was observed by light microscopy and studied in detail by electron microscopy. The shape of the external tubes of the fultoportulae, considered as an important taxonomic character, varied in S. subsalsum and S. pseudocostalum. We observed long threads in S. subsalsum and S. pseudocostatum, associated with unicellular or shortchained forms, probably to confer buoyancy. S. subsalsum, previously found only north of 40 ° N, is here reported for tropical waters. This is the first record of S. subsalsum and S. pseudocostatum in Mexico.
The purpose of this review is to explore the feasibility of bioaerosol fingerprinting based on current understanding of cellular debris (with an emphasis on human-emitted particulates) in aerosols and arguments regarding sampling, sensitivity, separations and detection schemes. Target aerosol particles include cellular material and proteins emitted by humans, animals and plants and can be considered information- rich packets that carry biochemical information specific to the living organisms present in the collection settings. In this work we discuss sampling and analysis techniques that can be integrated with molecular (e.g. protein) detection protocols to properly assess the aerosolized cellular material of interest. Developing a detailed understanding of bioaerosol molecular profiles in various environments suggests exciting possibilities of bioaerosol analysis with applications ranging from military defense to medical diagnosis and wildlife identification.
Spontaneous formation of long-range (millimeters) membrane-bound nanotubules from surface-immobilized liposomes is possible by application of modest electric fields (2 -20 V/cm), providing a novel fabrication strategy for these hollow cylindrical structures. Stable tubes generally aligned with the applied electric field were created from liposomes prepared with phosphatidylcholine (PC), phosphatidic acid (PA), phosphoethanolamine (PE), and cholesterol. The minimum voltage which causes nanotubular formation (the onset voltage) and the average number of tubules per liposome of varying composition was examined with fluorescent microscopy using labeled phospholipids. Generally, the onset voltages ranged between 4 and 15 V/cm and depended on the mother vesicle composition. The results of this study suggest that increasing the charged lipid content can decrease the onset voltage. Conversely, a cholesterol content of more than 30% (by mass) was found to hinder extension of lipid tubules. Basic calculations that assume lipid migration and domain formation on the mother liposome as a nucleating site for tubule extension are assessed and suggest this is a reasonable model to describe the mechanism of tubular growth from immobilized liposomes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.