University of Maryland, Baltimore County

About: University of Maryland, Baltimore County is a education organization based out in Baltimore, Maryland, United States. It is known for research contribution in the topics: Population & Aerosol. The organization has 8749 authors who have published 20843 publications receiving 795706 citations. The organization is also known as: UMBC.

Global aerosol climatology from the MODIS satellite sensors

Abstract: [1] The recently released Collection 5 Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol products provide a consistent record of the Earth's aerosol system. Comparing with ground-based AERONET observations of aerosol optical depth (AOD) we find that Collection 5 MODIS aerosol products estimate AOD to within expected accuracy more than 60% of the time over ocean and more than 72% of the time over land. This is similar to previous results for ocean and better than the previous results for land. However, the new collection introduces a 0.015 offset between the Terra and Aqua global mean AOD over ocean, where none existed previously. Aqua conforms to previous values and expectations while Terra is higher than what had been expected. The cause of the offset is unknown, but changes to calibration are a possible explanation. Even though Terra's higher ocean AOD is unexpected and unexplained, we present climatological analyses of data from both sensors. We find that the multiannual global mean AOD at 550 nm over oceans is 0.13 for Aqua and 0.14 for Terra, and over land it is 0.19 in both Aqua and Terra. AOD in situations with 80% cloud fraction are twice the global mean values, although such situations occur only 2% of the time over ocean and less than 1% of the time over land. Aerosol particle size associated with these very cloudy situations does not show a drastic change over ocean, but does over land. Regionally, aerosol amounts vary from polluted areas such as east Asia and India, to the cleanest regions such as Australia and the northern continents. As AOD increases over maritime background conditions, fine mode aerosol dominates over dust over all oceans, except over the tropical Atlantic downwind of the Sahara and during some months over the Arabian Sea.

Mouse 4T1 Breast Tumor Model

Abstract: The 4T1 mammary carcinoma is a transplantable tumor cell line that is highly tumorigenic and invasive and, unlike most tumor models, can spontaneously metastasize from the primary tumor in the mammary gland to multiple distant sites including lymph nodes, blood, liver, lung, brain, and bone The 4T1 tumor has several characteristics that make it a suitable experimental animal model for human mammary cancer. First, tumor cells are easily transplanted into the mammary gland so that the primary tumor grows in the anatomically correct site, as described in this unit. Second, as in human breast cancer, 4T1 metastatic disease develops spontaneously from the primary tumor. Also, the progressive spread of 4T1 metastases to the draining lymph nodes and other organs is very similar to that of human mammary cancer. In this unit, a protocol describes surgical removal of the primary tumor, so that metastatic disease can be studied in an animal setting comparable to the clinical situation where the primary tumor is surgically removed, and metastatic foci remain intact. Another advantage of 4T1 is its resistance to 6-thioguanine. This property enables precise quantitation of metastatic cells, even when they are disseminated and at sub-microscopic levels in distant organs, as described here.

Online shopping acceptance model — a critical survey of consumer factors in online shopping

Abstract: Since the late 1990s, online shopping has taken off as an increasing number of consumers purchase increasingly diversified products on the Internet. Given that how to attract and retain consumers is critical to the success of online retailers, research on the antecedents of consumer acceptance of online shopping has attracted widespread attention. There has yet to be a holistic view of online shopping acceptance from the perspective of consumers. In this research, we conducted an extensive survey of extant related studies and synthesized their findings into a reference model called OSAM (Online Shopping Acceptance Model) to explain consumer acceptance of online shopping. Our literature survey reveals that a myriad of factors have been examined in the context of online shopping and mixed results on those factors have been reported. The proposed model helps reconcile conflicting findings, discover recent trends in this line of research, and shed light on future research directions.

Texturing and Modeling: A Procedural Approach

Abstract: From the Publisher: This the classic text/tutorial/reference introducing and defining the procedural approach to texturing and modeling and computer graphics in general. This Second Edition is completely revised and updated to the current computer graphics marketplace. It contains a toolbox of procedures upon which programmers can build a library of textures and objects, and includes extensive explanations of how these functions work and how to design new functions. New chapters include: Cellular Texture Generation, Volumetric Cloud Modeling with Implicit Functions, Interacting with Virtual Actors, and Rendering with Adaptive Level of Detail.