290 research outputs found

    Interaction of GABA and Excitatory Amino Acids in the Basolateral Amygdala: Role in Cardiovascular Regulation

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    Activation of the amygdala in rats produces cardiovascular changes that include increases in heart rate and arterial pressure as well as behavioral changes characteristic of emotional arousal. The objective of the present study was to examine the interaction of GABA and excitatory amino acid (EAA) receptors in the basolateral amygdala (BLA) in regulating cardiovascular function. Microinjection of the GABAA receptor antagonist bicuculline methiodide (BMI) or the E A A receptor agonists NMDA or AMPA into the same region of the BLA of conscious rats produced dose-related increases in heart rate and arterial pressure. Injection of the nonselective EAA receptor antagonist kynurenic acid into the BLA prevented or reversed the cardiovascular changes caused by local injection of BMI or the noncompetitive GABA antagonist picrotoxin. Conversely, local pretreatment with the glutamate reuptake inhibitorl-trans-pyrrolidine-2,4-dicarboxylic acid enhanced the effects of intra-amygdalar injection of BMI. The cardiovascular effects of BMI were also attenuated by injection of either the NMDA antagonist 3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP) or the AMPA receptor antagonist 1,2,3,4-tetrahydro-6-nitro-2,3-dioxo-benzo[f]quinoxaline-7-sulfonamide (NBQX). When these two EAA receptor antagonists were combined, their ability to suppress BMI-induced tachycardic and pressor responses was additive. These findings indicate that the cardiovascular effects caused by blockade of GABAergic inhibition in the BLA of the rat are dependent on activation of local NMDA and AMPA receptors

    Status of vaccine research and development of vaccines for Nipah virus

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    AbstractNipah virus (NiV) is a highly pathogenic, recently emerged paramyxovirus that has been responsible for sporadic outbreaks of respiratory and encephalitic disease in Southeast Asia. High case fatality rates have also been associated with recent outbreaks in Malaysia and Bangladesh. Although over two billion people currently live in regions in which NiV is endemic or in which the Pteropus fruit bat reservoir is commonly found, there is no approved vaccine to protect against NiV disease. This report examines the feasibility and current efforts to develop a NiV vaccine including potential hurdles for technical and regulatory assessment of candidate vaccines and the likelihood for financing

    The FIRST-Optical-VLA Survey for Lensed Radio Lobes

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    We present results from a survey for gravitationally lensed radio lobes. Lensed lobes are a potentially richer source of information about galaxy mass distributions than lensed point sources, which have been the exclusive focus of other recent surveys. Our approach is to identify radio lobes in the FIRST catalog and then search optical catalogs for coincident foreground galaxies, which are candidate lensing galaxies. We then obtain higher-resolution images of these targets at both optical and radio wavelengths, and obtain optical spectra for the most promising candidates. We present maps of several radio lobes that are nearly coincident with galaxies. We have not found any new and unambiguous cases of gravitational lensing. One radio lobe in particular, FOV J0743+1553, has two hot spots that could be multiple images produced by a z=0.19 spiral galaxy, but the lensing interpretation is problematic.Comment: 38 pages, 18 figures, aastex, accepted to A

    FAPRI 2000 World Agricultural Outlook

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    The Food and Agricultural Policy Research Institute (FAPRI) prepares a preliminary agricultural outlook on world agricultural production, consumption, and trade every fall. This is followed by an outside review, re-evaluation of projections, and completion of the final baseline in January. The FAPRI 2000 World Agricultural Outlook presents these final projections for world agricultural markets. A companion volume, the FAPRI 2000 U.S. Agricultural Outlook, presents the U.S. component of the baseline. FAPRI projections assume average weather patterns worldwide, existing policy, and policy commitments under current trade agreements. FAPRI projections do not include conjectures on potential policy changes, such as those resulting from the likely eastward enlargement of the European Union (EU). The baseline predicts recovery of world agricultural production, consumption, and trade, but with remaining price weakness for crops. Stock-to-use ratios in world crop markets remain high despite the strong recovery of Asian and Latin American economies. Above-average yields kept world production high relative to demand in 1999. In contrast, pork and beef prices are increasing significantly above their 1999 level. The physical volume of U.S. agricultural exports is projected to reverse the downward trend of fiscal year (FY) 1999, whereas the value of agricultural exports continue to decline for one more year before recovering because of low crop prices in 2000/01. World crop trade is projected to increase by 55 million metric tons (mmt) in the coming decade, with the United States capturing 49 percent of the expanded market, but still unable to increase its market share by a large percentage. Following this expansion of the market, grain prices increase by 35 percent in the projection period, but still stay well below the peak of 1995/96. The increase in world crop trade reflects the increasing specialization occurring in world agriculture. Increased market access and land scarcity in many Asian economies induce them to import grains and oilseeds to meet their feed demand. Developing Asia remains the fastest growing market for corn in the next decade. With implementation of Agenda 2000 reforms, the EU will reduce its wheat domestic price relative to the world price and will export wheat without subsidies after 2004, constraining gains in market shares for the United States. EU barley exports will expand significantly in the coming years but are likely to be constrained by General Agreement on Tariffs and Trade (GATT) commitments on export subsidies after 2004. World meat trade will increase by 31 percent over the next decade. The United States has become a competitive producer and exporter of meat products. In the coming decade, the United States will experience the largest meat export growth rates among major exporters of beef, pork, and broilers. U.S. exporters capture more than 70 percent of the growth in trade, increasing their share of the combined meat markets from 23 percent in 1999 to 37 percent in 2009. Meat imports are recovering and expanding rapidly in Japan, South Korea, and Taiwan. In Japan, the share of imports in consumption increases from 38 percent in the 1990s to 49 percent at the end of the next decade. Taiwan meat imports will triple from 1990-1999 levels to 2000-2009 levels, driven by imports of beef, non muscle pork products, and the opening of the poultry market. Recovery of Asian food demand will prompt dairy prices to grow by about 1 percent per year over the next decade. Total milk production is projected to increase, with particularly strong growth in the United States, Mexico, Argentina, and Brazil. Most of the growth occurs through yield increases. Per capita cheese consumption is expected to grow by 1 to 2 percent a year in most countries.Crop Production/Industries, Livestock Production/Industries,

    The α1 Subunit of the GABA(A) Receptor Modulates Fear Learning and Plasticity in the Lateral Amygdala

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    Synaptic plasticity in the amygdala is essential for emotional learning. Fear conditioning, for example, depends on changes in excitatory transmission that occur following NMDA receptor activation and AMPA receptor modification in this region. The role of these and other glutamatergic mechanisms have been studied extensively in this circuit while relatively little is known about the contribution of inhibitory transmission. The current experiments addressed this issue by examining the role of the GABA(A) receptor subunit α1 in fear learning and plasticity. We first confirmed previous findings that the α1 subunit is highly expressed in the lateral nucleus of the amygdala. Consistent with this observation, genetic deletion of this subunit selectively enhanced plasticity in the lateral amygdala and increased auditory fear conditioning. Mice with selective deletion of α1 in excitatory cells did not exhibit enhanced learning. Finally, infusion of a α1 receptor antagonist into the lateral amygdala selectively impaired auditory fear learning. Together, these results suggest that inhibitory transmission mediated by α1-containing GABA(A) receptors plays a critical role in amygdala plasticity and fear learning

    The State of Coral Reef Ecosystems of Southeast Florida

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    The northern extension of the Florida reef tract and a complex of limestone ridges run parallel to the subtropical Atlantic coastline of southeast Florida. Spanning 170 km from the northern border of Biscayne National Park (BNP) in Miami-Dade County to the St. Lucie Inlet in Martin County, the reefs and hardbottom areas in this region support a rich and diverse biological community (Figure 5.1). Nearshore reef habitats in southeast Florida include hardbottom areas, patch reefs and worm reefs (Phragmatopoma spp.) exhibiting abundant octocoral, macroalgae, stony coral and sponge assemblages. Offshore, coral reef associated biotic assemblages occur on linear Holocene Acropora palmata mid-shelf and shelf margin reefs that extend from Miami Dade County to Palm Beach County (Lighty, 1977; Figure 5.2). Anastasia Formation limestone ridges and terraces colonized by reef biota characterize the reefs from Palm Beach County to Martin County (Cooke and Mossom, 1929). The coastal region of southeast Florida is highly developed, containing one third of Florida’s population of 16 million people (U.S. Census Bureau, 2006). Many southeast Florida reefs are located just 1.5 km from this urbanized shoreline. Despite their unique position as the highest latitude reefs along the western Atlantic seaboard, the reefs of southeast Florida have only recently received limited scientific and resource management attention. Andrews et al. (2005) discussed the reefs of southeast Florida and the critical need to implement actions that fill resource knowledge gaps and address conservation and threats to reef health. This report further examines and updates the list of stressors imperiling the health of southeast Florida’s reefs, and presents information gained from new research, monitoring and management efforts to determine the extent and condition of reef resources in this distinctive region
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