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Sample records for central american agouti

  1. Central American resource studies

    SciTech Connect

    Van Eeckhout, E.; Laughlin, A.W.

    1989-01-01

    Los Alamos National Laboratory has been working with five Central American countries to assist in the development of their energy and mineral resources. Since 1985, mineral resources in Costa Rica, peat resources in Costa Rica and Panama, geothermal energy resources in Honduras and Guatemala, and geothermal field development in El Salvador and Costa Rica have been topics of study. This paper presents an overview of this work -- within these proceedings are papers that deal with specific aspects of each topic, and these will be duly noted. 15 refs., 4 figs.

  2. The 8818G allele of the agouti signaling protein (ASIP) gene is ancestral and is associated with darker skin color in African Americans.

    PubMed

    Bonilla, Carolina; Boxill, Lesley-Anne; Donald, Stacey Ann Mc; Williams, Tyisha; Sylvester, Nadeje; Parra, Esteban J; Dios, Sonia; Norton, Heather L; Shriver, Mark D; Kittles, Rick A

    2005-04-01

    Skin color, a predictor of social interactions and risk factor for several types of cancer, is due to two contrasting forms of melanin, the darker eumelanin and lighter phaeomelanin. The lighter pigment phaeomelanin is the product of the antagonistic function of the agouti signaling protein (ASIP) on the alpha-melanocyte stimulating hormone receptor (MC1R). Studies have shown that a single-nucleotide polymorphism (SNP) in the 3'UTR of the ASIP gene is associated with dark hair and eyes; however, little is known about its role in inter-individual variation in skin color. Here we examine the relationship between the ASIP g.8818A>G SNP and skin color (M index) as assessed by reflectometry in 234 African Americans. Analyses of variance (ANOVA) were performed to evaluate the effects of ASIP genotypes, age, individual ancestry, and sex on skin color variation. Significant effects on M index variation were observed for ASIP genotypes (F(2,236)=4.37, P=0.01), ancestry (F(1,243)=37.2, P<0.001), and sex (F(1,244)=4.08, P=0.05). Subsequent analyses revealed a strong effect on M index from ASIP genotypes in African American females (P<0.001). Our study suggests that the ASIP G>A polymorphism exhibits a dominant effect leading to lighter skin color and that variation in the ASIP gene may have been one of several factors contributing to reductions in pigmentation in some populations. Further study is needed to reveal how interactions between ASIP and several other genes, such as MC1R and P, predict human pigmentation.

  3. Analysis of the function of the agouti gene in obesity and diabetes

    SciTech Connect

    Mynatt, R.L.; Miltenberger, R.J.; Klebig, M.L.

    1996-09-01

    This chapter discusses the agouti gene and dominant mutations in that gene that lead to agouti-induced obesity, and recent work with transgenic mice to elucidate the role of agouti in obesity. Agouti was cloned in 1992 by the lab of Rick Woychik at Oak Ridge National Laboratory, making it the first of many recently cloned mouse obesity genes. Sequence analysis predicted that mouse agouti is a secreted protein of 131 amino acids. The mature protein has a basic central region (lys57-arg85), a proline-rich domain (pro86-pro91) and a C-terminal region (cys 92-cys 13 1) containing 10 cysteine residues which form 5 disulfide bonds. The human homologue of agouti has also been cloned by the Woychik lab and maps to human chromosome 20q 11.2. Human agouti is 132 amino acids long and is 85% similar to the mouse agouti protein and is normally expressed in adipose tissue. The researchers have been able to recapitulate obesity, hyperinsulinemia, and hyperglycemia with the ubiquitous expression of agouti. Agouti expression in either liver and adipose tissue alone does not cause obesity, and there`s a dose-dependent effect of agouti on body weight, food efficiency, body temperature, and insulin and glucose levels.

  4. Agouti regulates adipocyte transcription factors.

    PubMed

    Mynatt, R L; Stephens, J M

    2001-04-01

    Agouti is a secreted paracrine factor that regulates pigmentation in hair follicle melanocytes. Several dominant mutations cause ectopic expression of agouti, resulting in a phenotype characterized by yellow fur, adult-onset obesity and diabetes, increased linear growth and skeletal mass, and increased susceptibility to tumors. Humans also produce agouti protein, but the highest levels of agouti in humans are found in adipose tissue. To mimic the human agouti expression pattern in mice, transgenic mice (aP2-agouti) that express agouti in adipose tissue were generated. The transgenic mice develop a mild form of obesity, and they are sensitized to the action of insulin. We correlated the levels of specific regulators of insulin signaling and adipocyte differentiation with these phenotypic changes in adipose tissue. Signal transducers and activators of transcription (STAT)1, STAT3, and peroxisome proliferator-activated receptor (PPAR)-gamma protein levels were elevated in the transgenic mice. Treatment of mature 3T3-L1 adipocytes recapitulated these effects. These data demonstrate that agouti has potent effects on adipose tissue. We hypothesize that agouti increases adiposity and promotes insulin sensitivity by acting directly on adipocytes via PPAR-gamma.

  5. Central American geologic map project

    SciTech Connect

    Dengo, G.

    1986-07-01

    During the Northeast Quadrant Panel meeting of the Circum-Pacific Map Project held in Mexico City, February 1985, Central American panel members proposed and adopted plans for compiling a geologic map of Central America, probably at a scale of 1:500,000. A local group with participants from each country was organized and coordinated by Rolando Castillo, director, Central American School of Geology, University of Costa Rica, for the geologic aspects, and Fernando Rudin, director, Geographic Institute of Costa Rica, for the topographic base. In 1956, the US Geological Survey published a geologic map of the region at a scale of 1:1 million. Subsequent topographic and geologic mapping projects have provided a large amount of new data. The entire area is now covered by topographic maps at a scale of 1:50,000, and these maps have been used in several countries as a base for geologic mapping. Another regional map, the Metallogenic Map of Central America (scale = 1:2 million), was published in 1969 by the Central American Research Institute for Industry (ICAITI) with a generalized but updated geologic base map. Between 1969 and 1980, maps for each country were published by local institutions: Guatemala-Belize at 1:500,000, Honduras at 1:500,000, El Salvador at 1:100,000, Nicaragua at 1:1 million, Costa Rica at 1:200,000, and Panama at 1:1 million. This information, in addition to that of newly mapped areas, served as the base for the Central American part of the Geologic-Tectonic Map of the Caribbean Region (scale = 1:2.5 million), published by the US Geological Survey in 1980, and also fro the Northeast Quadrant Maps of the Circum-Pacific Region. The new project also involves bathymetric and geologic mapping of the Pacific and Caribbean margins of the Central American Isthmus. A substantial amount of new information of the Middle America Trench has been acquired through DSDP Legs 67 and 84.

  6. Placentation in the capybara (Hydrochaerus hydrochaeris), Agouti (Dasyprocta aguti) and paca (Agouti paca).

    PubMed

    Miglino, M A; Carter, A M; dos Santos Ferraz, R H; Fernandes Machado, M R

    2002-05-01

    Placentae of three hystricimorph rodents--capybara, agouti and paca--were examined by conventional histology, immunohistochemistry for cytokeratin and vimentin, and TUNEL staining. The placentae were divided into lobules of labyrinthine syncytium separated by interlobular and marginal trophoblast. The subplacenta comprised cytotrophoblasts, supported on lamellae of allantoic mesoderm, and syncytiotrophoblast. The central excavation was still apparent in the definitive placenta of capybara. In agouti and paca, the decidua of the junctional zone formed a mesoplacenta comprising a capsule and a pedicle. Towards term the pedicle formed a tenuous attachment between placenta and uterine wall comprising a few maternal vessels surrounded by degraded tissue. In paca placenta, it was shown by TUNEL staining that breakdown of this tissue occurred by apoptosis. The visceral yolk sac was highly villous and, in agouti, the yolk sac villi were extremely long. Lateral to its attachment to the placenta, the fetal surface was covered with non-vascular yolk sac endoderm. A layer of spongiotrophoblast cells was interposed between the endoderm and the marginal trophoblast.

  7. Centralization and Decentralization in American Education Policy

    ERIC Educational Resources Information Center

    DeBoer, Jennifer

    2012-01-01

    This article examines the trend toward centralization in American education policy over the last century through a variety of lenses. The overall picture that emerges is one of a continuous tug-of-war, with national and local policymakers stumbling together toward incrementally more standardized and centralized policies. There is a center of power…

  8. Properties of the Central American cold surge

    NASA Technical Reports Server (NTRS)

    Mcguirk, James P.; Reding, Philip J.; Zhang, Yuxia

    1993-01-01

    The Central American cold surge (CACS) is a frontal incursion from the United States into Central America and resembles the East Asian cold surge. They occur more frequently than analyzed by NMC or by published results, based on our observations between 1979 and 1990. Climatology and structure are quantified, based on surface and upper air stations throughout Central America and satellite products from GOES visible and infrared sensors and SSM/I precipitable water and rain rate sensors.

  9. Molecular characterization of the mouse agouti locus.

    PubMed

    Bultman, S J; Michaud, E J; Woychik, R P

    1992-12-24

    The agouti (a) locus acts within the microenvironment of the hair follicle to regulate coat color pigmentation in the mouse. We have characterized a gene encoding a novel 131 amino acid protein that we propose is the one gene associated with the agouti locus. This gene is normally expressed in a manner consistent with a locus function, and, more importantly, its structure and expression are affected by a number of representative alleles in the agouti dominance hierarchy. In addition, we found that the pleiotropic effects associated with the lethal yellow (Ay) mutation, which include pronounced obesity, diabetes, and the development of neoplasms, are accompanied by deregulated overexpression of the agouti gene in numerous tissues of the adult animal.

  10. A Climatology of Central American Gyres

    NASA Astrophysics Data System (ADS)

    Papin, P. P.; Griffin, K. S.; Bosart, L. F.; Torn, R. D.

    2012-12-01

    Monsoon gyres, commonly found over the western Pacific Ocean, are characterized by broad low-level cyclonic circulations that occur at a variety of spatial scales ranging from 1500-3000 km. Low-level cyclonic gyre circulations, while less frequent and occupying a smaller scale, have also been observed over Central America during the tropical cyclone (TC) season. A noteworthy gyre observed during the 2010 PREDICT field project served as a "collector" of TC Matthew and a source for TC Nicole. During October 2011, devastating flooding occurred in Guatemala and El Salvador when TD 12-E, embedded in a gyre circulation, made landfall on the Pacific coast of Central America. These gyre occurrences, their apparent links to TC activity, and their association with high-impact weather motivates this presentation. A preliminary analysis of Central American gyres suggests that their spatial scales vary between 1000-2000 km. These gyres also tend to be co-located with reservoirs of deep moisture that are characterized by high precipitable water values (>50 mm) and embedded deep convection on their southern and eastern sides. Catastrophic flooding can occur when gyre cyclonic circulations interact with the topography of Central America. A Central American gyre climatology including gyre frequency over the TC season and individual gyre duration will be presented. This climatology is then used to craft a gyre composite using previous gyre cases from 1980-2010. Particular attention will be given to the common synoptic and sub-synoptic scale features that precede and take place during gyre formation. This includes the role that intraseasonal and interannual circulations such as the Madden-Julian Oscillation (MJO) and El Nino-Southern Oscillation (ENSO) might play in gyre development. TC genesis events within gyre circulations will also be highlighted and examined further. Finally, the results of a September 2010 case study will be used to illustrate the impact that Central American

  11. Dendritic structure varies as a function of eccentricity in V1: a quantitative study of NADPH diaphorase neurons in the diurnal South American rodent agouti, Dasyprocta prymnolopha.

    PubMed

    da Rocha, E G; Freire, M A M; Bahia, C P; Pereira, A; Sosthenes, M C K; Silveira, L C L; Elston, G N; Picanço-Diniz, C W

    2012-08-02

    The cerebral cortex is often described as a composite of repeated units or columns, integrating the same basic circuit. The 'ice-cube' model of cortical organization, and 'canonical' circuit, born from insights into functional architecture, still require systematic comparative data. Here we probed the anatomy of an individual neuronal type within V1 to determine whether or not its dendritic trees are consistent with the 'ice-cube' model and theories of canonical circuits. In a previous report we studied the morphometric variability of NADPH-diaphorase (NADPH-d) neurons in the rat auditory, visual and somatosensory primary cortical areas. Our results suggested that the nitrergic cortical circuitry of primary sensory areas are differentially specialized, probably reflecting peculiarities of both habit and behavior of the species. In the present report we specifically quantified the dendritic trees of NADPH-d type I neurons as a function of eccentricity within V1. Individual neurons were reconstructed in 3D, and the size, branching and space-filling of their dendritic trees were correlated with their location within the visuotopic map. We found that NADPH-d neurons became progressively smaller and less branched with progression from the central visual representation to the intermediate and peripheral visual representation. This finding suggests that aspects of cortical circuitry may vary across the cortical mantle to a greater extent that envisaged as natural variation among columns in the 'ice-cube' model. The systematic variation in neuronal structure as a function of eccentricity warrants further investigation to probe the general applicability of columnar models of cortical organization and canonical circuits.

  12. Description of a new species of Ixodes Latreille, 1795 (Acari: Ixodidae) and redescription of I. lasallei Méndez & Ortiz, 1958, parasites of agoutis and pacas (Rodentia: Dasyproctidae, Cuniculidae) in Central and South America.

    PubMed

    Apanaskevich, Dmitry A; Bermúdez, Sergio E

    2017-05-01

    Ixodes bocatorensis n. sp. (Acari: Ixodidae), is described based on adults ex agoutis (Rodentia: Dasyproctidae), pacas (Rodentia: Cuniculidae) and "tapir and sloth" (Perissodactyla: Tapiridae and Pilosa) from Colombia, Panama and Venezuela. Adults of I. bocatorensis n. sp. are similar to those of I. lasallei Méndez & Ortiz, 1958 but can be distinguished by the scutum dimensions, punctation pattern, gnathosoma and palpi measurements and their ratios, basis capituli anterior angle and shape of the spur of palpal segment I ventrally. For comparative purposes the female of I. lasallei is redescribed and the true male of this species is described for the first time. Studied adults of I. lasallei were found on agoutis, pacas and ocelot (Carnivora: Felidae) in Colombia, Peru and Venezuela.

  13. Temporal diversification of Central American cichlids

    PubMed Central

    2010-01-01

    Background Cichlid fishes are classic examples of adaptive radiation because of their putative tendency to explosively diversify after invading novel environments. To examine whether ecological opportunity increased diversification (speciation minus extinction) early in a species-rich cichlid radiation, we determined if Heroine cichlids experienced a burst of diversification following their invasion of Central America. Results We first reconstructed the Heroine phylogeny and determined the basal node to use as the root of Central American Heroine diversification. We then examined the influence of incomplete taxon sampling on this group's diversification patterns. First, we added missing species randomly to the phylogeny and assessed deviations from a constant rate of lineage accumulation. Using a range of species numbers, we failed to recover significant deviations from a pure-birth process and found little support for an early burst of diversification. Then, we examined patterns of lineage accumulation as nodes were increasingly truncated. We assumed that as we removed more recently diverged lineages that sampling would become more complete thereby increasing the power to detect deviations from a pure-birth model. However, truncation of nodes provided even less support for an early burst of diversification. Conclusions Contrary to expectations, our analyses suggest Heroine cichlids did not undergo a burst of diversification when they invaded from South America. Throughout their history in Central America, Heroine cichlids appear to have diversified at a constant rate. PMID:20840768

  14. Transmission Reinforcements in the Central American Regional Power System

    SciTech Connect

    Elizondo, Marcelo A.; Vallem, Mallikarjuna R.; Samaan, Nader A.; Makarov, Yuri V.; Vyakaranam, Bharat; Nguyen, Tony B.; Munoz, Christian; Herrera, Ricardo; Midence, Diego; Shpitsberg, Anna

    2016-07-25

    The Central American regional interconnected power system (SER) connects the countries members of the Central American regional electricity market (MER): Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, and Panama. The SER was a result of a long term regional effort, and was initially conceived to transfer 300 MW between countries. However, the current transfer limits between countries range from 70 MW to 300 MW. Regional entities, like CRIE (Regional Commission of Electrical Interconnection), EOR (Central American Regional System Operator), and CDMER (Board of Directors of the Central American Market) are working on coordinating the national transmission expansion plans with regional transmission planning efforts. This paper presents experience in Central America region to recommend transmission reinforcements to achieve 300 MW transfer capacity between any pair of member countries of the Central American regional electricity market (MER). This paper also provides a methodology for technical analysis and for coordination among the regional and national entities. This methodology is unique for transmission systems of these characteristics.

  15. A climatology of Central American Gyres

    NASA Astrophysics Data System (ADS)

    Papin, Philippe P.

    Central American gyres (CAGs) are large, low-level, cyclonic circulations that are observed over Central America during the tropical cyclone (TC) season. CAGs often occur in conjunction with TCs, and can result in torrential rainfall over portions of Central America, the Caribbean Islands, and eastern United States. The lack of prior research on CAGs, their apparent links to TC activity, and their association with high- impact weather motivates this study. To study CAG occurrence, an algorithm was developed to identify cyclonic circulations possessing similar characteristics to monsoon depressions (MDs) and monsoon gyres (MGs) in other ocean basins. This algorithm also includes a series of tests that distinguishes CAG events from large TCs and non-closed circulations. This algorithm was run between May-November 1980-2010 using the National Centers for Environmental Prediction Climate Forecast System Reanalysis 0.5o gridded dataset to produce the CAG climatology. 42 CAGs were classified (˜1.4 per season) with a bimodal distribution of occurrence favoring the early (May-Jun) and late (Sep-Nov) TC season. Stratification of CAG occurrence by the phase of the Madden Julian Oscillation (MJO) shows that over 75% of all CAGs develop in phases 8,1, and 2. A gyre-relative, time-lagged, CAG composite analysis is performed on CAG cases spanning from three days prior to two days after CAG formation. Positive low-level geopotential height anomalies are present in the east Pacific and Atlantic basins and are associated with anomalous low-level flow before the formation of the CAG. This results in increasing cyclonic vorticity near anomalously high precipitable water over Central America, a pattern that aids the generation of deep convection and the broad closed low-level cyclonic circulation that defines the CAG. CAGs are also split into two subsets using potential vorticity (PV) on the 350K isentropic surface. Tropical CAGs possess upper-tropospheric ridging associated with low

  16. Dynamics of the Central American Pacific

    NASA Astrophysics Data System (ADS)

    Vieytez, Begonia; Marrero-Díaz, Ángeles; José Machín, Francisco; José Gavidia, Francisco; Castro, Mi

    2014-05-01

    The Central American Pacific (CAP) is the area located in front of the Central America coast, within the Eastern Tropical Pacific region (ETP). The CAP dynamic is strongly influenced by the NE and SE trade winds, also this area is characterized by the presence of coastal wind jets at Gulf of Papagayo and Gulf of Panama, which are product of wind pulses blowing through the mountain gaps of the central cordillera, generating important eddies as the cyclonic eddy of Costa Rica Dome (CRD). Nevertheless, the implications of the topography of the continental margin of Central America in the determination of the dynamic processes in the area related to the action of winds and currents are still unknown. Between November and December 2010 (dry season), onboard the R/V Miguel Oliver, oceanographic parameters were measured in the CAP area, which despite its importance, has been poorly investigated until date. Available oceanographic information was processed in order to describe the dynamic along the Pacific coast of Central America, which is notable for its particularly strong stratification in the water column and the distribution of properties, as response to the presence of areas with high temperatures (above 28° C) and other areas with salinity minimum (less than 24). In this study was possible to distinguish three hydrographic zones: PM, south, in the adjacent region to Gulf of Panama, PY, in the center, in the adjacent region to Gulf of Papagayo, and FC, to the north, in the adjacent region to Gulf of Fonseca. The surface transformations of the water bodies, from south to north, observed in these zones could be indicting the presence of Costa Rica current. The prevailing wind system is the main force of variations in the surface distribution of the temperature in the area, and they are responsible of important structures as the anticyclonic eddy in front Gulf of Fonseca, eddies derived from the wind pulses of Gulf of Papagayo, and the relatively low temperatures in

  17. Tropical Cyclone Interactions Within Central American Gyres

    NASA Astrophysics Data System (ADS)

    Papin, P. P.; Bosart, L. F.; Torn, R. D.

    2014-12-01

    Central American gyres (CAGs) are broad (~1000 km diameter) low-level cyclonic circulations that organize over Central America during the tropical cyclone (TC) season. While CAGs have rarely been studied, prior work on similar circulations has been conducted on monsoon depressions (MDs) and monsoon gyres (MGs), which possess spatial scales of 1000 - 2500 km in the west Pacific basin. A key difference between MDs and MGs is related to the organization of vorticity around the low-level circulation. MDs possess a symmetrical vorticity pattern where vorticity accumulates near the circulation center over time, occasionally developing into a large TC. In contrast, MGs possess asymmetrical vorticity, organized in mesovorticies, which rotate cyclonically along the periphery of the MG circulation. Small tropical cyclones (TCs) occasionally develop from these mesovorticies. Interaction and development of TCs within CAGs are also common, as noted by a CAG identified during the 2010 PREDICT field project, which involved the interaction of TC Matthew and the development of TC Nicole within the larger CAG. This project is motivated by the lack of prior research on CAGs, as well as the complex scale interactions that occasionally occur between TCs and CAGs. This presentation focuses on the mutual interaction of vortices embedded in the larger-scale cyclonic flow comprising the CAG circulation. Case studies will be presented using a circulation framework to illustrate the relationship between different scale vorticity elements within the CAG. Some of these case studies resemble a MD-like evolution, where a large TC develops through the accumulation of symmetrical vorticity around the CAG (e.g. TC Opal 1995, TC Frances 1998). Other instances resemble a MG-like evolution, where smaller mesovorticies rotate around a common circulation center (e.g. TC Florence 1988). The circulation analysis framework aids in the diagnosis of interaction between different scale cyclonic vortices, and

  18. Leptin responsiveness in mice that ectopically express agouti protein.

    PubMed

    Harris, Ruth B S; Mitchell, Tiffany D; Mynatt, Randall L

    Agouti protein is an endogenous antagonist of melanocortin receptors (MCR), including MCR3 and MCR4, which have been implicated as part of the hypothalamic mechanism that mediates leptin-induced hypophagia. In this experiment we examined the effects of peripheral and central leptin administration in male and female beta-actin promoter (BAPa) mice that express agouti protein ectopically and have a phenotype that includes obesity and diabetes which is exaggerated in males compared with females. Intraperitoneal infusion of 10 microg leptin/day for 13 days caused weight loss and a transient inhibition of food intake in wild-type mice, with a greater effect in males than females. Male BAPa mice were resistant to leptin infusion whereas female mice lost weight. All of the mice lost body weight following a single intracerebroventricular injection of leptin but the effect was greater in female BAPa mice than any other group. There also was a delayed suppression of food intake that was the same for wild-type and BAPa female mice, whereas food intake recovered faster in BAPa than wild-type males. The dissociation between food intake and body weight loss implies a significant effect of leptin on energy expenditure in BAPa mice. These results demonstrate that the effect of leptin on energy balance is not entirely dependent upon the melanocortin system.

  19. The gross anatomy of the male reproductive system of a neotropical rodent: the agouti (Dasyprota leporina).

    PubMed

    Mollineau, W; Adogwa, A; Jasper, N; Young, K; Garcia, G

    2006-02-01

    The literature available on the agouti (Dasyprocta leporina) is very limited. The agouti is a Neotropical rodent found in Trinidad and Tobago, Central and South America. This study focuses on one of the many unexplored areas relating to the species, the male reproductive system. The results showed that the mean testicular length, diameter and weight was 3.67 +/- 0.12 cm, 1.67 +/- 0.04 cm and 5.03 +/- 0.52 g respectively. The paired testes and epididymis were found in contact with the abdominal muscles within scrotal pouches, which are evaginations of the caudoventral abdominal wall. The caput epididymis is enclosed by a fat body. The ductus deferens has a mean length and diameter of 10.98 +/- 0.40 cm and 0.14 +/- 0.01 cm respectively. At the urethral end of the ductus deferens the diameter of each duct expends to form the ampulla. The mean diameter of each of the ampulla was 0.25 cm. The accessory sex organs of the male agouti (D. leporina) include the vesicular glands, the coagulating glands, the prostate glands and the bulbourethral glands. The penis of the agouti is U-shaped with a mean length of 9.90 +/- 0.43 cm. The glans penis contains an os penis, a pair of lateral penile cartilages and paired ventral keratinaceous styles.

  20. Mexico’s Central American Policy: Apologies, Motivations, and Principles.

    DTIC Science & Technology

    1982-03-15

    President Gustavo Diaz Ordaz (1964-70) launched in early 1966 the first goodwill tour of the Central American nations ever undertaken by a Mexican...the North" and Mexico’s policies have intensified those concerns throughout the Caribbean Basin. As early as the 1960’s, when Diaz Ordaz laid the...Liberal reformer, Benito Juarez, played politics in Guatemala and later Porfirio Diaz was a "sporadic meddler in Central American affairs." 7

  1. 1. Copy of Drawing, 'American Steel & Wire Co., Central ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Copy of Drawing, 'American Steel & Wire Co., Central Furnace Works -- Sketch of Plant Showing Tracks & Buildings, 1913, Revised 3/10/31.' Drawing courtesy United States Steel Corporation, Lorain, Ohio. Credit Berni Rich, Score Photographs, August 1979, for photos 1 through 4 and 7 through 11. - Central Furnaces, 2650 Broadway, east bank of Cuyahoga River, Cleveland, Cuyahoga County, OH

  2. 2. Copy of Drawing, 'American Steel & Wire Company, Central ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Copy of Drawing, 'American Steel & Wire Company, Central Furnaces & Docks, General Plan of Works Showing Trestle, 1-3-39.' Drawing courtesy of United States Steel Corporation, Lorain, Ohio. - Central Furnaces, 2650 Broadway, east bank of Cuyahoga River, Cleveland, Cuyahoga County, OH

  3. Peptoid mimics of agouti related protein.

    PubMed

    Thompson, Darren A; Chai, Biao-Xin; Rood, Hilary L E; Siani, Michael A; Douglas, Nicholai R; Gantz, Ira; Millhauser, Glenn L

    2003-04-17

    The Agouti Related Protein (AGRP) is an endogenous antagonist of melanocortin-3 and -4 receptors, each of which plays a key role in body weight homeostasis. We designed a peptoid trimer based on AGRP 111-113 in which a single chiral atom is used to partially restrain the backbone structure. Peptoid 5 displaced both radiolabeled Nle4-alpha-MSH (IC(50)=3.1 microM) and AGRP (86-132) (IC(50)=1.9 microM) from the human melanocortin-4 receptor and functioned as an antagonist of alpha-MSH stimulated cAMP generation, thus providing an important lead in the development of AGRP mimetics.

  4. The Central American epidemic of CKD.

    PubMed

    Weiner, Daniel E; McClean, Michael D; Kaufman, James S; Brooks, Daniel R

    2013-03-01

    Recent reports have described an apparent epidemic of CKD along the Pacific coast of Central America, such that CKD is a leading cause of death among working-age men in lower-altitude agricultural communities in this region. Given the limited availability of kidney replacement therapies in this region, CKD often is a terminal diagnosis, lending greater urgency to the identification of a modifiable cause. This article discusses the epidemiology of CKD in this region, reviews the clinical features of this CKD outbreak, discusses potential causes and the evidence supporting these hypotheses, and highlights the wider implications of this epidemic of CKD.

  5. Central scalp alopecia photographic scale in African American women.

    PubMed

    Olsen, E A; Callender, V; Sperling, L; McMichael, A; Anstrom, K J; Bergfeld, W; Durden, F; Roberts, J; Shapiro, J; Whiting, D A

    2008-01-01

    Central centrifugal cicatricial alopecia (CCCA) is a common but poorly understood cause of hair loss in African American women. A photographic scale was developed that captures the pattern and severity of the central hair loss seen with CCCA in order to help identify this problem in the general community and to potentially correlate clinical data with hair loss. The utility and reproducibility of this photographic scale was determined in a group of 150 African American women gathered for a health and beauty day who were evaluated by both four investigators experienced in the diagnosis of hair disorders and by the subjects themselves.

  6. Structural and Molecular Evolutionary Analysis of Agouti and Agouti-Related Proteins

    PubMed Central

    Jackson, Pilgrim J.; Douglas, Nick R.; Chai, Biaoxin; Binkley, Jonathan; Sidow, Arend; Barsh, Gregory S.; Millhauser, Glenn L.

    2010-01-01

    Summary Agouti (ASIP) and Agouti-related protein (AgRP) are endogenous antagonists of melanocortin receptors that play critical roles in the regulation of pigmentation and energy balance, respectively, and which arose from a common ancestral gene early in vertebrate evolution. The N-terminal domain of ASIP facilitates antagonism by binding to an accessory receptor, but here we show that the N-terminal domain of AgRP has the opposite effect and acts as a prodomain that negatively regulates antagonist function. Computational analysis reveals similar patterns of evolutionary constraint in the ASIP and AgRP C-terminal domains, but fundamental differences between the N-terminal domains. These studies shed light on the relationships between regulation of pigmentation and body weight, and they illustrate how evolutionary structure function analysis can reveal both unique and common mechanisms of action for paralogous gene products. PMID:17185225

  7. Central American Environmental Defense Program in the Mesoamerican Biological Corridor

    DTIC Science & Technology

    2002-06-01

    and its vulnera- bility to natural disasters, Mesoamerica is comprised of Mexico’s five southernmost states and the seven Central American countries...natural disasters suffered in the Mesoamerica . CSL 1 June 2002 Issues Paper 06-02 Report Documentation Page Form ApprovedOMB No. 0704-0188 Public

  8. Family Experiences of Central American Refugees Who Overestimate Intergenerational Gaps

    ERIC Educational Resources Information Center

    Merali, Noorfarah

    2004-01-01

    The present study aimed to assess the role of perception in shaping family realities after immigration. Research participants included six Central American parent-adolescent dyads who perceived each other to be further apart in their acceptance of cultural change than indicated by their self-ratings of behavioural shifts towards Western norms. The…

  9. Middle Miocene closure of the Central American Seaway.

    PubMed

    Montes, C; Cardona, A; Jaramillo, C; Pardo, A; Silva, J C; Valencia, V; Ayala, C; Pérez-Angel, L C; Rodriguez-Parra, L A; Ramirez, V; Niño, H

    2015-04-10

    Uranium-lead geochronology in detrital zircons and provenance analyses in eight boreholes and two surface stratigraphic sections in the northern Andes provide insight into the time of closure of the Central American Seaway. The timing of this closure has been correlated with Plio-Pleistocene global oceanographic, atmospheric, and biotic events. We found that a uniquely Panamanian Eocene detrital zircon fingerprint is pronounced in middle Miocene fluvial and shallow marine strata cropping out in the northern Andes but is absent in underlying lower Miocene and Oligocene strata. We contend that this fingerprint demonstrates a fluvial connection, and therefore the absence of an intervening seaway, between the Panama arc and South America in middle Miocene times; the Central American Seaway had vanished by that time. Copyright © 2015, American Association for the Advancement of Science.

  10. Predicting the Impacts of Climate Change on Central American Agriculture

    NASA Astrophysics Data System (ADS)

    Winter, J. M.; Ruane, A. C.; Rosenzweig, C.

    2011-12-01

    Agriculture is a vital component of Central America's economy. Poor crop yields and harvest reliability can produce food insecurity, malnutrition, and conflict. Regional climate models (RCMs) and agricultural models have the potential to greatly enhance the efficiency of Central American agriculture and water resources management under both current and future climates. A series of numerical experiments was conducted using Regional Climate Model Version 3 (RegCM3) and the Weather Research and Forecasting Model (WRF) to evaluate the ability of RCMs to reproduce the current climate of Central America and assess changes in temperature and precipitation under multiple future climate scenarios. Control simulations were thoroughly compared to a variety of observational datasets, including local weather station data, gridded meteorological data, and high-resolution satellite-based precipitation products. Future climate simulations were analyzed for both mean shifts in climate and changes in climate variability, including extreme events (droughts, heat waves, floods). To explore the impacts of changing climate on maize, bean, and rice yields in Central America, RCM output was used to force the Decision Support System for Agrotechnology Transfer Model (DSSAT). These results were synthesized to create climate change impacts predictions for Central American agriculture that explicitly account for evolving distributions of precipitation and temperature extremes.

  11. The energy situation in five Central American countries

    SciTech Connect

    Trocki, L.; Booth, S.R.; Umana Q, A.

    1987-06-01

    This study describes the energy resources and the changes that have taken place in energy supply and demand in five Central American countries between 1970 and 1984. Economic changes are also reviewed because they influence and are affected by changes in the energy sector. The work was performed under the auspices of the US Agency for International Development. The Central American countries of Costa Rica, El Salvador, Guatemala, Honduras, and Panama are highly dependent on fuel wood as a source of energy, particularly in the residential sector. They also rely upon imported oil products to supply a growing modern sector. Most countries have significant hydroelectric and geothermal resources, and most countries produce a large portion of their electricity from hydroelectric projects. Demand for electricity has grown rapidly. Relative shares of primary versus secondary energy in the five countries vary significantly and strongly correlate with average per capita income. Consumption of secondary energy has declined during the recent economic recession suffered by the region.

  12. The Central American Network for Disaster and Health Information

    PubMed Central

    Arnesen, Stacey J.; Cid, Victor H.; Scott, John C.; Perez, Ricardo; Zervaas, Dave

    2007-01-01

    Purpose: This paper describes an international outreach program to support rebuilding Central America's health information infrastructure after several natural disasters in the region, including Hurricane Mitch in 1998 and two major earthquakes in 2001. Setting, Participants, and Description: The National Library of Medicine joined forces with the Pan American Health Organization/World Health Organization, the United Nations International Strategy for Disaster Reduction, and the Regional Center of Disaster Information for Latin America and the Caribbean (CRID) to strengthen libraries and information centers in Central America and improve the availability of and access to health and disaster information in the region by developing the Central American Network for Disaster and Health Information (CANDHI). Through CRID, the program created ten disaster health information centers in medical libraries and disaster-related organizations in six countries. Results/Outcome: This project served as a catalyst for the modernization of several medical libraries in Central America. The resulting CANDHI provides much needed electronic access to public health “gray literature” on disasters, as well as access to numerous health information resources. CANDHI members assist their institutions and countries in a variety of disaster preparedness activities through collecting and disseminating information. PMID:17641767

  13. Comments to Middle Miocene closure of the Central American Seaway

    USGS Publications Warehouse

    Coates, A.G.; Stallard, Robert F.

    2016-01-01

    In a recent paper proposing an early (mid-Miocene) closure of the Central American Seaway (CAS), Montes et al. 2015 (1) disregard existing paleogeographic data that invalidate Panama as a source for zircons, and inappropriately ignore the evidence for trans-isthmian marine connections until 4-3 Ma. They also fail to cite previous work (2, 3), that had reconstructed the Central American arc already docked with South America by 12 Ma. Montes et al. 2015 (1) (Fig. 1) disregard the Atrato-San Juan sedimentary basin (3), a shallowing Oligocene to Pliocene, Pacific to Caribbean seaway (3, 4, 5). This deep graben (6) is filled with thousands of meters of Pre-Pliocene marine sediments (3, 5, 6) that now occupy a lowland between the Baudo uplift to the west and the Western Cordillera to the east. The Mande Batholith and numerous Eocene and younger volcanic rocks (4), the most proximal source of the zircons, are situated to the east of this seaway and would have shed zircons eastward towards the Cordillera Central. There is no evidence for any rivers crossing the seaway (3, 5), and thus no Panamanian source of zircons. Instead this seaway is evidence of a significant marine connection between the Pacific and Atlantic oceans into the Pliocene. The authors assume that the middle Miocene closure of the CAS effectively creates a continuous land bridge connecting North and South America and separating the Atlantic from the Pacific. They acknowledge, but then discount, marine connections across the Isthmus until 4-3 Ma even though these satisfactorily explain (Coates and Stallard, 2014 (6)) the oceanographic, molecular and Great American Biological Interchange events ignore unexplained by Montes et al. 2015. Only by conspicuously ignoring these events can they imply that the Isthmus was formed at 15-13 Ma. References 1. C. Montes et al., Middle Miocene closure of the Central American Seaway. Science 348, 226-229 (2015). 2. A. G. Coates, R. F. Stallard, How old is the Isthmus of

  14. July 1973 ground survey of active Central American volcanoes

    NASA Technical Reports Server (NTRS)

    Stoiber, R. E. (Principal Investigator); Rose, W. I., Jr.

    1973-01-01

    The author has identified the following significant results. Ground survey has shown that thermal anomalies of various sizes associated with volcanic activity at several Central American volcanoes should be detectable from Skylab. Anomalously hot areas of especially large size (greater than 500 m in diameter) are now found at Santiaguito and Pacaya volcanoes in Guatemala and San Cristobal in Nicaragua. Smaller anomalous areas are to be found at least seven other volcanoes. This report is completed after ground survey of eleven volcanoes and ground-based radiation thermometry mapping at these same points.

  15. MMPI performance of central American refugees and Mexican immigrants.

    PubMed

    Clark, S; Callahan, W J; Lichtszajn, J; Velasquez, R J

    1996-12-01

    This study compared the MMPI scores of Central American refugees from Guatemala and El Salvador to those of Mexican immigrants. It was expected that subjects from Guatemala and El Salvador would obtain higher scores on the F, D, Pa, and Sc scales because these subjects came from "war-torn" countries. A multivariate analysis of variance yielded no significant differences between the three groups on any of the validity and clinical scales including F, D, Pa, and Sc. Recommendations for cross-national research are noted especially in light of the new version, or MMPI-2.

  16. Role of moisture transport for Central American precipitation

    NASA Astrophysics Data System (ADS)

    María Durán-Quesada, Ana; Gimeno, Luis; Amador, Jorge

    2017-02-01

    A climatology of moisture sources linked with Central American precipitation was computed based upon Lagrangian trajectories for the analysis period 1980-2013. The response of the annual cycle of precipitation in terms of moisture supply from the sources was analysed. Regional precipitation patterns are mostly driven by moisture transport from the Caribbean Sea (CS). Moisture supply from the eastern tropical Pacific (ETPac) and northern South America (NSA) exhibits a strong seasonal pattern but weaker compared to CS. The regional distribution of rainfall is largely influenced by a local signal associated with surface fluxes during the first part of the rainy season, whereas large-scale dynamics forces rainfall during the second part of the rainy season. The Caribbean Low Level Jet (CLLJ) and the Chocó Jet (CJ) are the main conveyors of regional moisture, being key to define the seasonality of large-scale forced rainfall. Therefore, interannual variability of rainfall is highly dependent of the regional LLJs to the atmospheric variability modes. The El Niño-Southern Oscillation (ENSO) was found to be the dominant mode affecting moisture supply for Central American precipitation via the modulation of regional phenomena. Evaporative sources show opposite anomaly patterns during warm and cold ENSO phases, as a result of the strengthening and weakening, respectively, of the CLLJ during the summer months. Trends in both moisture supply and precipitation over the last three decades were computed, results suggest that precipitation trends are not homogeneous for Central America. Trends in moisture supply from the sources identified show a marked north-south seesaw, with an increasing supply from the CS Sea to northern Central America. Long-term trends in moisture supply are larger for the transition months (March and October). This might have important implications given that any changes in the conditions seen during the transition to the rainy season may induce stronger

  17. Agouti expression in human adipose tissue: functional consequences and increased expression in type 2 diabetes.

    PubMed

    Smith, Steven R; Gawronska-Kozak, Barbara; Janderová, Lenka; Nguyen, Taylor; Murrell, Angela; Stephens, Jacqueline M; Mynatt, Randall L

    2003-12-01

    It is well recognized that the agouti/melanocortin system is an important regulator of body weight homeostasis. Given that agouti is expressed in human adipose tissue and that the ectopic expression of agouti in adipose tissue results in moderately obese mice, the link between agouti expression in human adipose tissue and obesity/type 2 diabetes was investigated. Although there was no apparent relationship between agouti mRNA levels and BMI, agouti mRNA levels were significantly elevated in subjects with type 2 diabetes. The regulation of agouti in cultured human adipocytes revealed that insulin did not regulate agouti mRNA, whereas dexamethasone treatment potently increased the levels of agouti mRNA. Experiments with cultured human preadipocytes and with cells obtained from transgenic mice that overexpress agouti demonstrated that melanocortin receptor (MCR) signaling in adipose tissue can regulate both preadipocyte proliferation and differentiation. Taken together, these results reveal that agouti can regulate adipogenesis at several levels and suggest that there are functional consequences of elevated agouti levels in human adipose tissue. The influence of MCR signaling on adipogenesis combined with the well-established role of MCR signaling in the hypothalamus suggest that adipogenesis is coordinately regulated with food intake and energy expenditure.

  18. Bidirectional Influence between African American Mothers' and Children's Racial Centrality from Elementary through High School

    ERIC Educational Resources Information Center

    Hoffman, Adam J.; Kurtz-Costes, Beth; Rowley, Stephanie J.; Adams, Elizabeth A.

    2017-01-01

    For many African Americans, racial identity is an important aspect of their individual identity. We explored developmental change and stability of individual differences in the racial centrality of African American youths and their mothers as well as the relation between maternal and child racial centrality across time. African American youths (N…

  19. Hydroclimatological Processes in the Central American Dry Corridor

    NASA Astrophysics Data System (ADS)

    Hidalgo, H. G.; Duran-Quesada, A. M.; Amador, J. A.; Alfaro, E. J.; Mora, G.

    2015-12-01

    This work studies the hydroclimatological variability and the climatic precursors of drought in the Central American Dry Corridor (CADC), a subregion located in the Pacific coast of Southern Mexico and Central America. Droughts are frequent in the CADC, which is featured by a higher climatological aridity compared to the highlands and Caribbean coast of Central America. The CADC region presents large social vulnerability to hydroclimatological impacts originated from dry conditions, as there is a large part of population that depends on subsistance agriculture. The influence of large-scale climatic precursors such as ENSO, the Caribbean Low-Level Jet (CLLJ), low frequency signals from the Pacific and Caribbean and some intra-seasonal signals such as the MJO are evaluated. Previous work by the authors identified a connection between the CLLJ and CADC precipitation. This connection is more complex than a simple rain-shadow effect, and instead it was suggested that convection at the exit of the jet in the Costa-Rica and Nicaragua Caribbean coasts and consequent subsidence in the Pacific could be playing a role in this connection. During summer, when the CLLJ is stronger than normal, the Inter-Tropical Convergence Zone (located mainly in the Pacific) displaces to a more southern position, and vice-versa, suggesting a connection between these two processes that has not been fully explained yet. The role of the Western Hemisphere Warm Pool also needs more research. All this is important, as it suggest a working hypothesis that during summer, the effect of the Caribbean wind strength may be responsible for the dry climate of the CADC. Another previous analysis by the authors was based on downscaled precipitation and temperature from GCMs and the NCEP/NCAR reanalysis. The data was later used in a hydrological model. Results showed a negative trend in reanalysis' runoff for 1980-2012 in San José (Costa Rica) and Tegucigalpa (Honduras). This highly significant drying trend

  20. Subduction and Recycling of Nitrogen Along the Central American Margin

    NASA Astrophysics Data System (ADS)

    Fischer, Tobias P.; Hilton, David R.; Zimmer, Mindy M.; Shaw, Alison M.; Sharp, Zachary D.; Walker, James A.

    2002-08-01

    We report N and He isotopic and relative abundance characteristics of volatiles emitted from two segments of the Central American volcanic arc. In Guatemala, δ15N values are positive (i.e., greater than air) and N2/He ratios are high (up to 25,000). In contrast, Costa Rican N2/He ratios are low (maximum 1483) and δ15N values are negative (minimum -3.0 per mil). The results identify shallow hemipelagic sediments, subducted into the Guatemalan mantle, as the transport medium for the heavy N. Mass balance arguments indicate that the subducted N is efficiently cycled to the atmosphere by arc volcanism. Therefore, the subduction zone acts as a ``barrier'' to input of sedimentary N to the deeper mantle.

  1. Melanism in Peromyscus Is Caused by Independent Mutations in Agouti

    PubMed Central

    Kingsley, Evan P.; Manceau, Marie; Wiley, Christopher D.; Hoekstra, Hopi E.

    2009-01-01

    Identifying the molecular basis of phenotypes that have evolved independently can provide insight into the ways genetic and developmental constraints influence the maintenance of phenotypic diversity. Melanic (darkly pigmented) phenotypes in mammals provide a potent system in which to study the genetic basis of naturally occurring mutant phenotypes because melanism occurs in many mammals, and the mammalian pigmentation pathway is well understood. Spontaneous alleles of a few key pigmentation loci are known to cause melanism in domestic or laboratory populations of mammals, but in natural populations, mutations at one gene, the melanocortin-1 receptor (Mc1r), have been implicated in the vast majority of cases, possibly due to its minimal pleiotropic effects. To investigate whether mutations in this or other genes cause melanism in the wild, we investigated the genetic basis of melanism in the rodent genus Peromyscus, in which melanic mice have been reported in several populations. We focused on two genes known to cause melanism in other taxa, Mc1r and its antagonist, the agouti signaling protein (Agouti). While variation in the Mc1r coding region does not correlate with melanism in any population, in a New Hampshire population, we find that a 125-kb deletion, which includes the upstream regulatory region and exons 1 and 2 of Agouti, results in a loss of Agouti expression and is perfectly associated with melanic color. In a second population from Alaska, we find that a premature stop codon in exon 3 of Agouti is associated with a similar melanic phenotype. These results show that melanism has evolved independently in these populations through mutations in the same gene, and suggest that melanism produced by mutations in genes other than Mc1r may be more common than previously thought. PMID:19649329

  2. Understanding Seismotectonic Aspects of Central and South American Subduction Zones

    NASA Astrophysics Data System (ADS)

    Vargas-Jiménez, Carlos A.; Monsalve-Jaramillo, Hugo; Huérfano, Victor

    2004-10-01

    The Circum-Pacific, and particularly the Central and South America, subduction zones are complex structures that are subject to frequent, large-magnitude earthquakes, volcanic activity, tsunamis, and geological hazards. Among these natural hazards, earthquakes produce the most significant social and economic impacts in Latin America, and the subduction zones therefore demand constant vigilance and intensive study. The American continent has witnessed serveral earthquakes that rank among the most destrive in the world. Earthquakes such as the ones that occurred in Colombia-Ecuador [Mw = 8.9, 1906], Chile [Mw = 9.6, 1960; Mw = 8.9, 1995], Mexico [Mw = 9.6, 1985], and Peru [Mw = 8.0, 2001], as well as a number of destuctive events related to crustal fault systems and volcanic eruptions [e.g., Soufrière, El Ruiz, Galeras, ect.], have produced significant human and economic loss.The latent seismic hazards in the Caribbean, and Central and South America demand from the regional Earth sciences community accurate models to explain the mechanisms of these natural phenomena.

  3. Use and Implications of Ethnomedical Health Care Approaches among Central American Immigrants.

    ERIC Educational Resources Information Center

    Murguia, Alejandro; Peterson, Rolf A.; Zea, Maria Cecilia

    2003-01-01

    Central American health beliefs and practices are largely influenced by religious and indigenous worldviews. Study assesses the use of ethnomedical approaches and the illnesses for which these approaches are used among 76 Central Americans. Results indicate the importance of understanding and integrating cultural and spiritual influences on…

  4. Sourcebook on Central American Refugee Policy: A Bibliography with Subject and Country Index. Special Project Report.

    ERIC Educational Resources Information Center

    Gutierrez, Margo, Comp.; And Others

    This bibliography on Central American refugee policy is the outgrowth of a year-long research seminar on the topic at the Lyndon B. Johnson School of Public Affairs of the University of Texas at Austin during 1983-1984. That seminar was concerned with several aspects of Central American refugee policy, including policies of the various Central…

  5. Associations between central nervous system serotonin, fasting glucose, and hostility in African American females.

    PubMed

    Boyle, Stephen H; Georgiades, Anastasia; Brummett, Beverly H; Barefoot, John C; Siegler, Ilene C; Matson, Wayne R; Kuhn, Cynthia M; Grichnik, Katherine; Stafford-Smith, Mark; Williams, Redford B; Kaddurah-Daouk, Rima; Surwit, Richard S

    2015-02-01

    Previous research has shown an association between hostility and fasting glucose in African American women. Central nervous system serotonin activity is implicated both in metabolic processes and in hostility related traits. The purpose of this study is to determine whether central nervous system serotonin influences the association between hostility and fasting glucose in African American women. The study consisted of 119 healthy volunteers (36 African American women, 27 White women, 21 White males, and 35 African American males, mean age 34 ± 8.5 years). Serotonin related compounds were measured in cerebrospinal fluid. Hostility was measured by the Cook-Medley Hostility Scale. Hostility was associated with fasting glucose and central nervous system serotonin related compounds in African American women only. Controlling for the serotonin related compounds significantly reduced the association of hostility to glucose. The positive correlation between hostility and fasting glucose in African American women can partly be explained by central nervous system serotonin function.

  6. Associations between Central Nervous System Serotonin, Fasting Glucose and Hostility in African American Females

    PubMed Central

    Boyle, Stephen H.; Georgiades, Anastasia; Brummett, Beverly H.; Barefoot, John C.; Siegler, Ilene C.; Matson, Wayne R.; Kuhn, Cynthia M.; Grichnik, Katherine; Stafford-Smith, Mark; Williams, Redford B.; Kaddurah-Daouk, Rima; Surwit, Richard S.

    2015-01-01

    Background Previous research has shown an association between hostility and fasting glucose in African American women. Central nervous system serotonin activity is implicated both in metabolic processes and in hostility related traits. Purpose To determine whether central nervous system serotonin influences the association between hostility and fasting glucose in African American women. Methods The study consisted of 119 healthy volunteers (36 African American women, 27 white women, 21 white males, and 35 African American males, mean age 34±8.5 years). Serotonin metabolites were measured in cerebrospinal fluid. Hostility was measured by the Cook-Medley Hostility Scale. Results Hostility was associated with fasting glucose and central nervous system serotonin metabolites in African American women only. Controlling for the serotonin metabolites significantly reduced the association of hostility to glucose. Conclusions The positive correlation between hostility and fasting glucose in African American women can partly be explained by central nervous system serotonin function. PMID:24806470

  7. Influenza and other respiratory viruses in three Central American countries

    PubMed Central

    Laguna‐Torres, Victor A.; Sánchez‐Largaespada, José F.; Lorenzana, Ivette; Forshey, Brett; Aguilar, Patricia; Jimenez, Mirna; Parrales, Eduardo; Rodriguez, Francisco; García, Josefina; Jimenez, Ileana; Rivera, Maribel; Perez, Juan; Sovero, Merly; Rios, Jane; Gamero, María E.; Halsey, Eric S.; Kochel, Tadeusz J.

    2010-01-01

    Please cite this paper as: Laguna‐Torres et al. (2011) Influenza and other respiratory viruses in three Central American countries. Influenza and Other Respiratory Viruses 5(2), 123–134. Background  Despite the disease burden imposed by respiratory diseases on children in Central America, there is a paucity of data describing the etiologic agents of the disease. Aims  To analyze viral etiologic agents associated with influenza‐like illness (ILI) in participants reporting to one outpatient health center, one pediatric hospital, and three general hospitals in El Salvador, Honduras, and Nicaragua Material & Methods  Between August 2006 and April 2009, pharyngeal swabs were collected from outpatients and inpatients. Patient specimens were inoculated onto cultured cell monolayers, and viral antigens were detected by indirect and direct immunofluorescence staining. Results  A total of 1,756 patients were enrolled, of whom 1,195 (68.3%) were under the age of 5; and 183 (10.4%) required hospitalization. One or more viral agents were identified in 434 (24.7%) cases, of which 17 (3.9%) were dual infections. The most common viruses isolated were influenza A virus (130; 7.4% of cases), respiratory syncytial virus (122; 6.9%), adenoviruses (63; 3.6%), parainfluenza viruses (57; 3.2%), influenza B virus (47; 2.7% of cases), and herpes simplex virus 1 (22; 1.3%). In addition, human metapneumovirus and enteroviruses (coxsackie and echovirus) were isolated from patient specimens. Discussion  When compared to the rest of the population, viruses were isolated from a significantly higher percentage of patients age 5 or younger. The prevalence of influenza A virus or influenza B virus infections was similar between the younger and older age groups. RSV was the most commonly detected pathogen in infants age 5 and younger and was significantly associated with pneumonia (p < 0.0001) and hospitalization (p < 0.0001). Conclusion  Genetic analysis of influenza

  8. Isolation and characterization of Agouti: a diabetes/obesity related gene

    DOEpatents

    Woychik, Richard P.

    1998-01-01

    The present invention relates to the cloning and expression of the Agouti gene and analogous genes in transformed, transfected and transgenic mice. The present invention provides an animal model for the study of diabetes, obesity and tumors for the testing of potential therapeutic agents. The present invention provides oligonucleotide probes for the detection of the Agouti gene and mutations in the gene. The present invention also relates to the isolation and recombinant production of the Agouti gene product, production of antibodies to the Agouti gene product and their use as diagnostic and therapeutic agents.

  9. Isolation and characterization of Agouti: a diabetes/obesity related gene

    DOEpatents

    Woychik, Richard P.

    2000-06-27

    The present invention relates to the cloning and expression of the Agouti gene and analogous genes in transformed, transfected and transgenic mice. The present invention provides an animal model for the study of diabetes, obesity and tumors for the testing of potential therapeutic agents. The present invention provides oligonucleotide probes for the detection of the Agouti gene and mutations in the gene. The present invention also relates to the isolation and recombinant production of the Agouti gene product, production of antibodies to the Agouti gene product and their use as diagnostic and therapeutic agents.

  10. Evolution of Geochemical Variations Along the Central American Volcanic Front

    NASA Astrophysics Data System (ADS)

    Saginor, I. S.; Gazel, E.; Condie, C.; Carr, M. J.

    2014-12-01

    New geochemical analyses of volcanic rocks in El Salvador add to existing data from Nicaragua and Costa Rica to create a comprehensive set of geochemical data for Central American volcanics. These data coupled with previously published 40Ar/39Ar ages covering the past 30 Ma shows that Costa Rica and Nicaragua had similar U/Th and Ba/La values until 10 Ma when the region developed the distinctive along arc variations that made this margin famous. U/Th values increased in Nicaragua since the Miocene, while remaining unchanged along the rest of the volcanic front. This coincides temporally with the Carbonate Crash, which caused a transition in Cocos plate sediments from low-U carbonates to high-U, organic rich hemipelagic muds. Increases in uranium are not observed in Costa Rica because its lower slab dip produces a more diffuse zone of partial melting and because of the contribution from Galapagos-derived tracks dilutes this signal. Ba/La has been used as a geochemical proxy for contributions from the subducting slab, however our analyses indicate that the Ba concentrations do not vary significantly along strike either in the subducting sediment or the volcanic front. Along-arc variation is controlled by changes in La, an indicator of the degree of partial melting or source enrichment. Trace element models of five segments of the volcanic front suggest that a subducting sediment component is more important to magmas produced in El Salvador and Nicaragua than in Costa Rica, where the geochemistry is controlled by recent (<10 Ma) recycling of Galapagos tracks.

  11. Evolution of geochemical variations along the Central American volcanic front

    NASA Astrophysics Data System (ADS)

    Saginor, Ian; Gazel, Esteban; Condie, Claire; Carr, Michael J.

    2013-10-01

    New geochemical analyses of volcanic rocks in El Salvador add to existing data from Nicaragua and Costa Rica to create a comprehensive set of geochemical data for Central American volcanics. These data coupled with previously published 40Ar/39Ar ages covering the past 30 Ma show that Costa Rica and Nicaragua had similar U/Th and Ba/La values until 10 Ma when the region developed the distinctive along arc variations that made this margin famous. U/Th values increased in Nicaragua since the Miocene, while remaining unchanged along the rest of the volcanic front. This coincides temporally with the Carbonate Crash, which caused a transition in Cocos plate sediments from low-U carbonates to high-U, organic rich hemipelagic muds. Increases in uranium are not observed in Costa Rica because its lower slab dip produces a more diffuse zone of partial melting and because of the contribution from Galapagos-derived tracks dilutes this signal. Ba/La has been used as a geochemical proxy for contributions from the subducting slab; however, our analyses indicate that the Ba concentrations do not vary significantly along strike either in the subducting sediment or the volcanic front. Along-arc variation is controlled by changes in La, an indicator of the degree of partial melting or source enrichment. Trace element models of five segments of the volcanic front suggest that a subducting sediment component is more important to magmas produced in El Salvador and Nicaragua than in Costa Rica, where the geochemistry is controlled by recent (<10 Ma) recycling of Galapagos tracks.

  12. Differentiating Central Centrifugal Cicatricial Alopecia and Androgenetic Alopecia in African American Men

    PubMed Central

    Davis, Erica C.; Reid, Sophia D.; Sperling, Leonard C.

    2012-01-01

    Central centrifugal cicatricial alopecia is a scarring alopecia that is predominantly seen in African American women, but occurs less frequently in men. The authors present three cases of African American men with biopsy-proven central centrifugal cicatricial alopecia and detail the clinical presentation, histological findings, and treatment regimens. Central centrifugal cicatricial alopecia should be considered in the differential diagnosis when evaluating male patients with vertex hair loss accompanied by scalp symptoms. Physicians should maintain a high index of suspicion in African American men with the appropriate clinical picture and confirm the diagnosis by scalp biopsy. Prompt and appropriate treatment can help halt or slow disease progression. PMID:22768355

  13. Differentiating central centrifugal cicatricial alopecia and androgenetic alopecia in african american men: report of three cases.

    PubMed

    Davis, Erica C; Reid, Sophia D; Callender, Valerie D; Sperling, Leonard C

    2012-06-01

    Central centrifugal cicatricial alopecia is a scarring alopecia that is predominantly seen in African American women, but occurs less frequently in men. The authors present three cases of African American men with biopsy-proven central centrifugal cicatricial alopecia and detail the clinical presentation, histological findings, and treatment regimens. Central centrifugal cicatricial alopecia should be considered in the differential diagnosis when evaluating male patients with vertex hair loss accompanied by scalp symptoms. Physicians should maintain a high index of suspicion in African American men with the appropriate clinical picture and confirm the diagnosis by scalp biopsy. Prompt and appropriate treatment can help halt or slow disease progression.

  14. Modeling Central American basalts using the Arc Basalt Simulator

    NASA Astrophysics Data System (ADS)

    Feigenson, M.; Carr, M. J.

    2011-12-01

    We have used the Arc Basalt Simulator (ABS), developed by JI Kimura, to explore the conditions and components of melting beneath the Central American volcanic front. ABS is a comprehensive forward model that incorporates slab dehydration and melting and mantle wedge fluxing and melting using realistic P-T conditions and experimentally determined phase relations. We have applied ABS versions 3 and 4 to model representative magma types in Nicaragua, which span a broad geochemical range including proximal high- and low-Ti lavas in Nicaragua. Sr-Nd-Pb data require appropriate selection of previously identified sources, including: separate carbonate and hemipelagic sediments, DMM, an enriched mantle isotopically similar to the alkaline basalts of Yojoa, a Himu-influenced mantle derived from Galapagos material and altered oceanic crust (AOC) derived from both MORB and Galapagos seamounts. Following the dry solidus, the dominant arc basalts, exemplified by Cerro Negro lavas, can be generated at about 80-90 km where lawsonite and zoisite break down, releasing LILEs into a hydrous fluid that travels into the wedge. The fluid-triggered melting occurs just above the garnet stability field in the wedge to fit the HREEs. Below 90 Km, slab melting begins and the AOC component dominates, generating a fluid with little or no HFSE depletions, consistent with the unusual high-Ti lavas found in Nicaragua. However, the isotopic data require a much lower sediment input for the high-Ti lavas (consistent with 10Be results on the high-Ti lavas) and an enriched component for the AOC and/or mantle wedge. Following the wet solidus, fits to the Cerro Negro magma only occur in the absence of phengite in the AOC and with the presence of HFSE attracting minerals, rutile, zircon and allanite. The depth of the best fit is 135 km, consistent with current best estimates of the depth to the seismic zone beneath Cerro Negro. Below 150 km, the high-Ti lavas can be generated if the HFSE retaining

  15. Agouti signaling protein stimulates cell division in "viable yellow" (A vy/a) mouse liver

    USDA-ARS?s Scientific Manuscript database

    Enhanced linear growth, hyperplasia, and tumorigenesis are well-known characteristics of "viable yellow" agouti Avy/- mice (1); however, the functional basis for this aspect of the phenotype is unknown. In the present study, we ascertained whether agouti signaling protein (ASIP) levels in Avy/a or a...

  16. Combined effects of insulin treatment and adipose tissue-specific agouti expression on the development of obesity.

    PubMed

    Mynatt, R L; Miltenberger, R J; Klebig, M L; Zemel, M B; Wilkinson, J E; Wilkinson, W O; Woychik, R P

    1997-02-04

    The agouti gene product is a secreted protein that acts in a paracrine manner to regulate coat color in mammals. Several dominant mutations at the agouti locus in mice cause the ectopic, ubiquitous expression of agouti, resulting in a condition similar to adult-onset obesity and non-insulin-dependent diabetes mellitus. The human agouti protein is 85% homologous to mouse agouti; however, unlike the mouse agouti gene, human agouti is normally expressed in adipose tissue. To address whether expression of agouti in human adipose tissue is physiologically relevant, transgenic mice were generated that express agouti in adipose tissue. Similar to most humans, these mice do not become obese or diabetic. However, we found that daily insulin injections significantly increased weight gain in the transgenic lines expressing agouti in adipose tissue, but not in nontransgenic mice. These results suggest that insulin triggers the onset of obesity and that agouti expression in adipose tissue potentiates this effect. Accordingly, the investigation of agouti's role in obesity and non-insulin-dependent diabetes mellitus in mice holds significant promise for understanding the pathophysiology of human obesity.

  17. Molecular analysis of the mouse agouti gene and the role of dominant agouti-locus mutations in obesity and insulin resistance

    SciTech Connect

    Klebig, M.L.; Woychik, R.P.; Wilkinson, J.E.

    1994-09-01

    The lethal yellow (A{sup y/-}) and viable yellow (A{sup vy/-}) mouse agouti mutants have a predominantly yellow pelage and display a complex syndrome that includes obesity, hyperinsulinemia, and insulin resistance, hallmark features of obesity-associated noninsulin-dependent diabetes mellitus (NIDDM) in humans. A new dominant agouti allele, A{sup iapy}, has recently been identified; like the A{sup vy} allele, it is homozygous viable and confers obesity and yellow fur in heterozygotes. The agouti gene was cloned and characterized at the molecular level. The gene is expressed in the skin during hair growth and is predicted to encode a 131 amino acid protein, that is likely to be a secreted factor. In both Ay/- and A{sup iapy}/- mice, the obesity and other dominant pleiotropic effects are associated with an ectopic expression of agouti in many tissues where the gene product is normally not produced. In Ay, a 170-kb deletion has occurred that causes an upstream promoter to drive the ectopic expression of the wild-type agouti coding exons. In A{sup iapy}, the coding region of the gene is expressed from a cryptic promoter within the LTR of an intracisternal A-particle (IAP), which has integrated within the region just upstream of the first agouti coding exon. Transgenic mice ubiquitously expressing the cloned agouti gene under the influence of the beta-actin and phosphoglycerate kinase promoters display obesity, hyperinsulinemia, and yellow coat color. This demonstrates unequivocally that ectopic expression of agouti is responsible for the yellow obese syndrome.

  18. Achieving the Dream: Undocumented Central American Latinas in College

    ERIC Educational Resources Information Center

    Figueroa, Maruth

    2013-01-01

    The increase in the U.S. Latino population and its diversity has gained much local and national attention of the need to learn more about their experiences in college (Torres, 2003). And although this body of research is growing, the work is limited to a segment of the Latino population. The literature has mainly focused on the Mexican American or…

  19. Achieving the Dream: Undocumented Central American Latinas in College

    ERIC Educational Resources Information Center

    Figueroa, Maruth

    2013-01-01

    The increase in the U.S. Latino population and its diversity has gained much local and national attention of the need to learn more about their experiences in college (Torres, 2003). And although this body of research is growing, the work is limited to a segment of the Latino population. The literature has mainly focused on the Mexican American or…

  20. Constructing "Deservingness": DREAMers and Central American Unaccompanied Children in the National Immigration Debate

    ERIC Educational Resources Information Center

    Pérez Huber, Lindsay

    2015-01-01

    Utilizing a Latina/o Critical Theory framework (LatCrit), I examine the narratives that emerged within national newsprint media coverage of DREAMers and Central American unaccompanied children. Data included 268 newspaper articles published during periods of heightened national media attention about DREAMers (96 articles) and Central American…

  1. Centralization and Decentralization: An International Viewpoint on an American Dilemma. A Special CASEA Report.

    ERIC Educational Resources Information Center

    Walker, William G.

    This report outlines the history of the centralization-decentralization dilemma in the goverance of organizations, discusses two types of centralization-decentralization continua, and suggests further research. The first type of continuum discussed -- the traditional American -- refers to decisionmaking in the areas of public debate and partisan…

  2. Constructing "Deservingness": DREAMers and Central American Unaccompanied Children in the National Immigration Debate

    ERIC Educational Resources Information Center

    Pérez Huber, Lindsay

    2015-01-01

    Utilizing a Latina/o Critical Theory framework (LatCrit), I examine the narratives that emerged within national newsprint media coverage of DREAMers and Central American unaccompanied children. Data included 268 newspaper articles published during periods of heightened national media attention about DREAMers (96 articles) and Central American…

  3. The Strategic Importance of Central Asia: An American View

    DTIC Science & Technology

    2008-01-01

    mir Mukhin calls a “ reanimation ” of the Soviet defense structure. Meanwhile Uzbek Su-27 and MiG-29 aircraft will be posted there as part of a regular...situation cannot be permitted to con- tinue, and “ reanimating ” the old Soviet air defense system while excluding US forces from Central Asia are key

  4. Regulation of PPARgamma and obesity by agouti/melanocortin signaling in adipocytes.

    PubMed

    Mynatt, Randall L; Stephens, Jacquelins M

    2003-06-01

    To study the potential biological role of agouti/melanocortin signaling in human adipose tissue, we engineered transgenic mice to overexpress agouti in adipose tissue. The aP2-agouti transgenic mice become significantly heavier than littermates. The increased body weight is maintained at approximately 15% above nontransgenic mice through 20 weeks and is caused by increased fat mass. The obesity is increased by a high-fat diet. There is no change in food intake in the aP2-agouti mice suggesting changes in energy utilization. A possible mechanism is that the agouti/melanocortin signaling regulates levels of PPARgamma. PPARgamma functions as a major regulator of adipocyte differentiation and as a receptor for the antidiabetic thiazolidinediones. Agouti increases PPARgamma protein levels in differentiated 3T3-L1 adipocytes, and PPARgamma expression is elevated in the fat pads of the aP2-agouti transgenic mice. The modest weight gain observed in the transgenic mice suggests that hypothalamic pathways regulating food intake are intact and the observed adiposity is within ranges that can be achieved by a paracrine mechanism at the adipocyte level.

  5. Mahogany (mg) stimulates feeding and increases basal metabolic rate independent of its suppression of agouti.

    PubMed

    Dinulescu, D M; Fan, W; Boston, B A; McCall, K; Lamoreux, M L; Moore, K J; Montagno, J; Cone, R D

    1998-10-13

    The mahogany (mg) locus originally was identified as a recessive suppressor of agouti, a locus encoding a skin peptide that modifies coat color by antagonizing the melanocyte-stimulating hormone receptor or MC1-R. Certain dominant alleles of agouti cause an obesity syndrome when ectopic expression of the peptide aberrantly antagonizes the MC4-R, a related melanocyte-stimulating hormone receptor expressed in hypothalamic circuitry and involved in the regulation of feeding behavior and metabolism. Recent work has demonstrated that mg, when homozygous, blocks not only the ability of agouti to induce a yellow coat color when expressed in the skin of the lethal yellow mouse (AY), but also the obesity resulting from ectopic expression of agouti in the brain. Detailed analysis of mg/mg AY/a animals, presented here, demonstrates that mg/mg blocks the obesity, hyperinsulinemia, and increased linear growth induced by ectopic expression of the agouti peptide. Remarkably, however, mg/mg did not reduce hyperphagia in the AY/a mouse. Furthermore, mg/mg induced hyperphagia and an increase in basal metabolic rate in the C57BL/6J mouse in the absence of AY. Consequently, although mahogany is broadly required for agouti peptide action, it also appears to be involved in the control of metabolic rate and feeding behavior independent of its suppression of agouti.

  6. Mahogany (mg) stimulates feeding and increases basal metabolic rate independent of its suppression of agouti

    PubMed Central

    Dinulescu, Daniela M.; Fan, Wei; Boston, Bruce A.; McCall, Kathleen; Lamoreux, M. Lynn; Moore, Karen J.; Montagno, Jill; Cone, Roger D.

    1998-01-01

    The mahogany (mg) locus originally was identified as a recessive suppressor of agouti, a locus encoding a skin peptide that modifies coat color by antagonizing the melanocyte-stimulating hormone receptor or MC1-R. Certain dominant alleles of agouti cause an obesity syndrome when ectopic expression of the peptide aberrantly antagonizes the MC4-R, a related melanocyte-stimulating hormone receptor expressed in hypothalamic circuitry and involved in the regulation of feeding behavior and metabolism. Recent work has demonstrated that mg, when homozygous, blocks not only the ability of agouti to induce a yellow coat color when expressed in the skin of the lethal yellow mouse (AY), but also the obesity resulting from ectopic expression of agouti in the brain. Detailed analysis of mg/mg AY/a animals, presented here, demonstrates that mg/mg blocks the obesity, hyperinsulinemia, and increased linear growth induced by ectopic expression of the agouti peptide. Remarkably, however, mg/mg did not reduce hyperphagia in the AY/a mouse. Furthermore, mg/mg induced hyperphagia and an increase in basal metabolic rate in the C57BL/6J mouse in the absence of AY. Consequently, although mahogany is broadly required for agouti peptide action, it also appears to be involved in the control of metabolic rate and feeding behavior independent of its suppression of agouti. PMID:9770550

  7. Molecular structure and chromosomal mapping of the human homolog of the agouti gene

    SciTech Connect

    Kwon, H.Y.; Woychik, R.P.; Bultman, S.J. |; Loeffler, C.; Hansmann, I.; Chen, W.J.; Furdon, P.J.; Wilkison, W.; Powell, J.G.; Usala, A.L.

    1994-10-11

    The agouti (a) locus in mouse chromosome 2 normally regulates coat color pigmentation. The mouse agouti gene was recently cloned and shown to encode a distinctive 131-amino acid protein with a consensus signal peptide. Here the authors describe the cloning of the human homolog of the mouse agouti gene using an interspecies DNA-hybridization approach. Sequence analysis revealed that the coding region of the human agouti gene is 85% identical to the mouse gene and has the potential to encode a protein of 132 amino acids with a consensus signal peptide. Chromosomal assignment using somatic-cell-hybrid mapping panels and fluorescence in situ hybridization demonstrated that the human agouti gene maps to chromosome band 20q11.2. This result revealed that the human agouti gene is closely linked to several traits, including a locus called MODY (for maturity onset diabetes of the young) and another region that is associated with the development of myeloid leukemia. Initial expression studies with RNA from several adult human tissues showed that the human agouti gene is expressed in adipose tissue and testis.

  8. Fisheries Management of Mexican and Central American Estuaries

    SciTech Connect

    Amezcua-Martinez, Felipe; Bellgraph, Brian J.

    2014-09-14

    The contributed papers in this book provide research undertaken in estuarine systems of Mexico and Central America that aim to provide a scientific basis for proper estuarine management. The book is divided in three parts that cover topics associated with fisheries management and regulations: physicochemical studies, ecological studies and socioeconomic studies. This introduction outlines the contents of this book in relation to the management of coastal ecosystems, which have a high socioeconomic importance for a large proportion of the population in this area of the world. Rather than be a definitive suite of papers for the regulation of these habitats, the goal of this book is to outline the urgent need to continue research of threatened coastal ecosystems of Mexico and Central America.

  9. Neogene Caribbean plate rotation and associated Central American tectonic evolution

    NASA Technical Reports Server (NTRS)

    Wadge, G.; Burke, K.

    1983-01-01

    A theoretical model of the opening of the Cayman Trough is developed on the basis of geological evidence from a wide area. It is proposed that strike slip motion began about 30 Myr ago and proceeded at a rate of 37 + or - 6 mm/yr for a total of 1100 km of relative plate displacement, and that Central America Underwent an anticlockwise rotation with internal plate deformation. Maps of the reconstructed motion are provided.

  10. 1996 Central New Mexico Section [American Chemical Society] annual report

    SciTech Connect

    Cournoyer, M.E.

    1997-02-07

    The main goal of the Central New Mexico Section this year was to increase attendance at the local meetings. Throughout the course of the year attendance at the meeting more than doubled. This was brought on by several factors: having the meeting spread throughout the section (Albuquerque, Santa Fe, Las Vegas, Socorro, Los Alamos); supplementing the ACS National Tour speakers with interesting local sections speakers; and making full use of the newly formed Public Relations Committee. Activities during 1996 are summarized.

  11. American Society of Hypertension position paper: central blood pressure waveforms in health and disease.

    PubMed

    Townsend, Raymond R; Rosendorff, Clive; Nichols, Wilmer W; Edwards, David G; Chirinos, Julio A; Fernhall, Bo; Cushman, William C

    2016-01-01

    A number of devices are available which noninvasively estimate central aortic blood pressure using a variety of approaches such as tonometry or oscillometry. In this position paper, we discuss how the central pressure waveform is generated and measured, how central pressure waveforms appear in health and disease, the predictive value of central blood pressure measurements, the effects of interventions on waveforms, and areas of future need in this field of clinical and research endeavor. Copyright © 2016 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

  12. Histochemical Characterization, Distribution and Morphometric Analysis of NADPH Diaphorase Neurons in the Spinal Cord of the Agouti

    PubMed Central

    Freire, Marco Aurélio M.; Tourinho, Suzane C.; Guimarães, Joanilson S.; Oliveira, Jorge Luiz F.; Picanço-Diniz, Cristovam W.; Gomes-Leal, Walace; Pereira, Antonio

    2008-01-01

    We evaluated the neuropil distribution of the enzymes NADPH diaphorase (NADPH-d) and cytochrome oxidase (CO) in the spinal cord of the agouti, a medium-sized diurnal rodent, together with the distribution pattern and morphometrical characteristics of NADPH-d reactive neurons across different spinal segments. Neuropil labeling pattern was remarkably similar for both enzymes in coronal sections: reactivity was higher in regions involved with pain processing. We found two distinct types of NADPH-d reactive neurons in the agouti's spinal cord: type I neurons had large, heavily stained cell bodies while type II neurons displayed relatively small and poorly stained somata. We concentrated our analysis on type I neurons. These were found mainly in the dorsal horn and around the central canal of every spinal segment, with a few scattered neurons located in the ventral horn of both cervical and lumbar regions. Overall, type I neurons were more numerous in the cervical region. Type I neurons were also found in the white matter, particularly in the ventral funiculum. Morphometrical analysis revealed that type I neurons located in the cervical region have dendritic trees that are more complex than those located in both lumbar and thoracic regions. In addition, NADPH-d cells located in the ventral horn had a larger cell body, especially in lumbar segments. The resulting pattern of cell body and neuropil distribution is in accordance with proposed schemes of segregation of function in the mammalian spinal cord. PMID:18958200

  13. Crustal structure along the southern Central American volcanic front

    NASA Astrophysics Data System (ADS)

    MacKenzie, Laura; Abers, Geoffrey A.; Fischer, Karen M.; Syracuse, Ellen M.; Protti, J. Marino; Gonzalez, Victor; Strauch, Wilfried

    2008-08-01

    Subduction alters continents several ways, including accretion, magmatic addition, mantle wedge serpentinization, and crustal differentiation. These changes affect seismic velocities, so characterizing upper plate crust establishes a baseline for composition and continental growth. Teleseismic P and PP arrivals from a temporary deployment of broadband seismometers in Central America have been used to estimate crustal thickness and Vp/Vs ratio from receiver functions and to image crust across the active arc. Crustal thickness ranges from 25 to 44 km with formal errors of 1.6-9.2 km. The thinnest crust (24.6 ± 3.5 km) lies directly beneath the Nicaraguan arc, whereas the thickest crust lies in the Nicaraguan back arc (43.5 ± 2.5 km) and beneath the Costa Rican arc (37.9 ± 5.2 km). Crustal structure and Vp/Vs show sharp transitions at terrane boundaries. The Moho exhibits strong velocity contrasts throughout the study area of ˜0.5-1.0 km/s, even beneath arc and fore arc, precluding extensive serpentinization or ponded melt below the Moho. Crust is thicker beneath the Costa Rican arc, consistent with 10-23 km3/km/Ma crustal growth. The crust is thinner by 11-18 km beneath the large depression in central Nicaragua, with the thinnest crust beneath the arc. There, the relationship between thin crust, arc location, and deeper seismic velocities suggests that upper plate structure plays a critical role in focusing magma to the surface.

  14. Seroprevalence survey of American trypanosomiasis in Central Valley of Toluca.

    PubMed

    Quijano-Hernández, Israel A; Castro-Barcena, Alejandro; Barbabosa-Pliego, Alberto; Ochoa-García, Laucel; Del Ángel-Caraza, Javier; Vázquez-Chagoyán, Juan C

    2012-01-01

    American trypanosomiasis is a growing health issue in the Americas. México is an endemic country, where some locations such as in the State of México are considered highly prevalent. In the valley of Toluca city, the capital of the State of Mexico, there exists an apparent high prevalence in dogs. The absence of triatomine vectors suggests that dogs may not be infected. Therefore, we conducted a directed survey to domiciliated and nondomiciliated dogs to reassess dogs' T. cruzi seroprevalence status. HAI and ELISA serologic tests were applied to 124 and 167 serums of domiciliated and nondomiciliated dogs in the target city. Risk factors were estimated, but the results did not show any evidence to assess them. No domiciliated dogs tested positive to both tests, whereas only one non-domiciliated dog resulted positive. This animal may have acquired the infection in an endemic area and then migrated to Toluca. Research results indicate that T. cruzi infection is not actively transmitted among dogs, and it is pointed out that dogs are the main sentinel animal population to evaluate a possible expansion of the territory affected by Chagas' disease.

  15. Diet-induced hypermethylation at agouti viable yellow is not inherited transgenerationally through the female

    USDA-ARS?s Scientific Manuscript database

    The effects of nonmutagenic environmental exposures can sometimes be transmitted for several generations, suggesting transgenerational inheritance of induced epigenetic variation. Methyl donor supplementation of female mice during pregnancy induces CpG hypermethylation at the agouti viable yellow (A...

  16. Central hair loss in African American women: incidence and potential risk factors.

    PubMed

    Olsen, Elise A; Callender, Valerie; McMichael, Amy; Sperling, Leonard; Anstrom, Kevin J; Shapiro, Jerry; Roberts, Janet; Durden, Faith; Whiting, David; Bergfeld, Wilma

    2011-02-01

    Although central scalp hair loss is a common problem in African American women, data on etiology or incidence are limited. We sought to determine the frequency of various patterns and degree of central scalp hair loss in African American women and to correlate this with information on hair care practices, family history of hair loss, and medical history. Five hundred twenty-nine subjects at six different workshops held at four different sites in the central and/or southeast United States participated in this study. The subjects' patterns and degree of central scalp hair loss were independently assessed by both subject and investigator using a standardized photographic scale. Subjects also completed a detailed questionnaire and had standardized photographs taken. Statistical analysis was performed evaluating answers to the questionnaire relative to pattern of central hair loss. Extensive central scalp hair loss was seen in 5.6% of subjects. There was no obvious association of extensive hair loss with relaxer or hot comb use, history of seborrheic dermatitis or reaction to a hair care product, bacterial infection, or male pattern hair loss in fathers of subjects; however, there was an association with a history of tinea capitis. There was no scalp biopsy correlation with clinical pattern of hair loss and further information on specifics of hair care practices is needed. This central scalp photographic scale and questionnaire provide a valid template by which to further explore potential etiologic factors and relationships to central scalp hair loss in African American women. Copyright © 2010 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

  17. Middle Miocene closure of the Central American Seaway

    NASA Astrophysics Data System (ADS)

    Montes, C.; Cardona, A.

    2014-12-01

    The final closure of the Panama Isthmus and permanent separation of Caribbean and Pacific waters is thought to have modified their salinity, faunistic assemblages, and ultimately, ocean circulation patterns and global climate. The Great American Biotic Interchange (GABI) is thought to have been the result of Plio-Pleistocene closure of the Isthmus that allowed land animals to massively cross the Isthmus. Similarly, the separation of Caribbean and Pacific waters by a rising Isthmus is thougth to be a prime example of vicariance. The role of Isthmus closure on global changes, however, remains controversial due in part to the difficulty of establishing a precise chronology of seaway closure. While timing of glaciation is well established, new data on the chronology of Isthmus emergence suggests that the process of closure is more complex, long, and old than previously thought. We sampled fluvial and shallow marine strata in northwesternmost South America to recover zircon grains for provenance analyses in the immediate vicinity of the docking site. Because the ages of magmatic provinces in northwestern South America and the Panama Isthmus are mutually exclusive, detrital zircon analyses provides a tool to evaluate land connections. We found that an uniquely Panamanian, 40-45 Ma (early Lutetian) detrital zircon fingerprint is abundant in middle Miocene strata, but absent in underlying lower Miocene and Oligocene strata of the northern Andes. This fingerprint represents the beginning of fluvial detrital exchange between the Panama arc and South America, and therefore marks the time of docking and the end of deep-water, and probably shallow-water connections by middle Miocene times.

  18. High Background Ozone Events in the Houston-Galveston-Brazoria Area: Effects from Central American Fires

    NASA Astrophysics Data System (ADS)

    Lei, R.; Wang, S. C.; Yang, S.; Wang, Y.; Talbot, R. W.

    2016-12-01

    The policy-relevant background (PRB) ozone is defined by the U.S. Environmental Protection Agency (EPA) as the surface ozone mixing ratio that would occur over the U.S. without North American anthropogenic emission influences. PRB ozone over the Houston-Galveston-Brazoria (HGB) area may be affected by foreign sources due to its unique geographical location and meteorology. Our monitoring data revealed several high ozone events over HGB area which might be caused by Central American fire during the years of 2013-2015. To qualify the effects from Central American fire, we estimated the US, Central American and worldwide background over HGB area during those events using the GEOS-Chem global 3-D model. Anomalies in fire emissions leading to high PRB ozone were mapped through spatiotemporal sampling of the Fire INventory from NCAR (FINN) along background trajectories of air masses affecting the HGB area prior to and during the selected high PRB ozone days. Daily HGB PRB ozone estimated by researchers at the Texas Commission on Environmental Quality (TCEQ) was used as the data source to validate model results. Results showed that contribution of emission from Central American to HGB PRB ozone could be tripled during fire events compared to non-impacted fire days. Besides fire emissions from Central American, different types of meteorological events (e.g., cold fronts and thunderstorms) and high local photochemical production (e.g., heat waves and stagnation) are also found associated with high PRB ozone in HGB area during these events. Thus we imply that synthetic contribution from foreign sources and local meteorology to HGB PRB ozone warrants further investigated.

  19. Agouti regulation of intracellular calcium: role in the insulin resistance of viable yellow mice.

    PubMed Central

    Zemel, M B; Kim, J H; Woychik, R P; Michaud, E J; Kadwell, S H; Patel, I R; Wilkison, W O

    1995-01-01

    Several dominant mutations at the agouti locus in the mouse cause a syndrome of marked obesity, hyperinsulinemia, and insulin resistance. Although it is known that the agouti gene is expressed in an ectopic manner in these mutants, the precise mechanism by which the agouti gene product mediates these effects is unclear. Since intracellular Ca2+ is believed to play a role in mediating insulin action and dysregulation of Ca2+ flux is observed in diabetic animals and humans, we examined the status of intracellular Ca2+ in mice carrying the dominant agouti allele, viable yellow (Avy). We show here that in mice carrying this mutation, the intracellular free calcium concentration ([Ca2+]i) is elevated in skeletal muscle, and the degree of elevation is closely correlated with the degree to which the mutant traits are expressed in individual animals. Moreover, we demonstrate that the agouti gene product is capable of inducing increased [Ca2+]i in cultured and freshly isolated skeletal muscle myocytes from wild-type mice. Based on these findings, we present a model in which we propose that the agouti polypeptide promotes insulin resistance in mutant animals through its ability to increase [Ca2+]i. Images Fig. 1 Fig. 3 PMID:7761392

  20. Agouti regulation of intracellular calcium: Role in the insulin resistance of viable yellow mice

    SciTech Connect

    Zemel, M.B.; Kim, J.H.; Woychik, R.P.; Michaud, E.J.; Hadwell, S.H.; Patel, I.R.; Wilkison, W.O.

    1995-05-23

    Several dominant mutations at the agouti locus in the mouse cause a syndrome of marked obesity, hyperinsulinemia, and insulin resistance. Although it is known that the agouti gene is expressed in an ectopic manner in these mutants, the precise mechanism by which the agouti gene product mediates these effects is unclear. Since intracellular Ca{sup 2+} is believed to play a role in mediating insulin action and dysregulation of Ca{sup 2+} flux is observed in diabetic animals and humans, we examined the status of intracellular Ca{sup 2+} in mice carrying the dominant agouti allele, viable yellow (A{sup vy}). We show here that in mice carrying this mutation, the intracellular free calcium concentration ([Ca{sup 2+}]{sub i}) is elevated in skeletal muscle, and the degree of elevation is closely correlated with the degree to which the mutant traits are expressed in individual animals. Moreover, we demonstrate that the agouti gene product is capable of inducing increased [Ca{sup 2+}]{sub i} in cultured and freshly isolated skeletal muscle myocytes from wild-type mice. Based on these findings, we present a model in which we propose that the agouti polypeptide promotes insulin resistance in mutant animals through its ability to increase [Ca{sup 2+}]{sub i}. 36 refs., 3 figs., 2 tabs.

  1. Inverse modeling of Central American lavas: old lithospheric and young asthenospheric heterogeneities

    NASA Astrophysics Data System (ADS)

    Feigenson, M.; Gazel, E.; Carr, M. J.

    2009-12-01

    In recent years, there have been a number of models proposed to account for the OIB-like geochemical characteristics of lavas from central Costa Rica. The source for most basalts of the Central American volcanic front (ranging from Guatemala to northern Costa Rica) is dominantly DM (depleted MORB-source mantle) fluxed by subduction-derived fluids. In contrast, central Costa Rican basalts display striking isotopic similarities to the Galapagos hotspot. How the Galapagos signature is introduced into the Central American source is at the heart of the conflicting theories. Several models incorporate asthenospheric flow of this enriched mantle, either around the Central American arc via South America, or through a slab window, which may have opened about 5 my ago beneath central Costa Rica. Alternatively, passage of the Caribbean plate over the Galapagos hotspot may have left veins of unerupted melt within the sub-Caribbean lithosphere. These veins may be preferentially tapped during later superimposed arc volcanism. Although these models yield identical isotopic systematics, it may be possible to distinguish between them by a geochemical technique that can indicate the presence of garnet in the source region. This method, developed by Hofmann and coworkers in the 1980s, is termed inverse modeling, and uses the variation of REEs in lavas to assess the relative importance of garnet vs. clinopyroxene during partial melting. We have applied this method to new REE data from back arc lavas throughout Central America, and preliminary results indicate that garnet is not present in their sources. In contrast, direct slab melts (adakites) from Central America, as well as volcanic front lavas and alkaline basalt (with minimal slab signature) from central Costa Rica and Panama, require a source with garnet. Therefore, enriched mantle in the back arc is likely stored in the shallow lithosphere rather than introduced through asthenospheric flow. Enriched material in the volcanic

  2. Un dia en la vida: The Everyday Activities of Young Children from Central American Immigrant Families

    ERIC Educational Resources Information Center

    Denmark, Nicole; Jones Harden, Brenda

    2012-01-01

    The aim of this article was to explore the everyday activities of young children from low-income Central American (CA) immigrant families. From the perspective that everyday activities propel children's development of culturally and contextually valued behaviours and skills, 48 mothers were interviewed regarding the activities that are available…

  3. Seroprevalence of Toxoplasma gondii in American Black Bears ( Ursus americanus ) of the Central Appalachians, USA.

    PubMed

    Cox, John J; Murphy, Sean M; Augustine, Ben C; Guthrie, Joseph M; Hast, John T; Maehr, Sutton C; McDermott, Joseph

    2017-07-01

    We assessed Toxoplasma gondii seroprevalence in 53 free-ranging American black bears ( Ursus americanus ) in the Central Appalachian Mountains, US. Seroprevalence was 62% with no difference between males and females or between juvenile and adult bears. Wildlife agencies should consider warnings in hunter education programs to reduce the chances for human infection from this source.

  4. 7 CFR 319.56-40 - Peppers from certain Central American countries.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 5 2011-01-01 2011-01-01 false Peppers from certain Central American countries. 319... accordance with the procedures described in § 319.56-5 of this subpart. (2) A pre-harvest inspection of the..., and tomato yellow mosaic virus, and if these pests are found to be generally infesting the...

  5. Drake passage and central american seaway controls on the distribution of the oceanic carbon reservoir

    SciTech Connect

    Fyke, Jeremy G.; D'Orgeville, Marc; Weaver, Andrew J.

    2015-05-01

    A coupled carbon/climate model is used to explore the impact of Drake Passage opening and Central American Seaway closure on the distribution of carbon in the global oceans. We find that gateway evolution likely played an important role in setting the modern day distribution of oceanic dissolved inorganic carbon (DIC), which is currently characterized by relatively low concentrations in the Atlantic ocean, and high concentrations in the Southern, Indian, and Pacific oceans. In agreement with previous studies, we find a closed Drake Passage in the presence of an open Central American Seaway results in suppressed Atlantic meridional overturning and enhanced southern hemispheric deep convection. Opening of the Drake Passage triggers Antarctic Circumpolar Current flow and a weak Atlantic meridional overturning circulation (AMOC). Subsequent Central American Seaway closure reinforces the AMOC while also stagnating equatorial Pacific subsurface waters. These gateway-derived oceanographic changes are reflected in large shifts to the global distribution of DIC. An initially closed Drake Passage results in high DIC concentrations in the Atlantic and Arctic oceans, and lower DIC concentrations in the Pacific/Indian/Southern oceans. Opening Drake Passage reverses this gradient by lowering mid-depth Atlantic and Arctic DIC concentrations and raising deep Pacific/Indian/Southern Ocean DIC concentrations. Central American Seaway closure further reinforces this trend through additional Atlantic mid-depth DIC decreases, as well as Pacific mid-depth DIC concentration increases, with the net effect being a transition to a modern distribution of oceanic DIC.

  6. Drake passage and central american seaway controls on the distribution of the oceanic carbon reservoir

    DOE PAGES

    Fyke, Jeremy G.; D'Orgeville, Marc; Weaver, Andrew J.

    2015-05-01

    A coupled carbon/climate model is used to explore the impact of Drake Passage opening and Central American Seaway closure on the distribution of carbon in the global oceans. We find that gateway evolution likely played an important role in setting the modern day distribution of oceanic dissolved inorganic carbon (DIC), which is currently characterized by relatively low concentrations in the Atlantic ocean, and high concentrations in the Southern, Indian, and Pacific oceans. In agreement with previous studies, we find a closed Drake Passage in the presence of an open Central American Seaway results in suppressed Atlantic meridional overturning and enhancedmore » southern hemispheric deep convection. Opening of the Drake Passage triggers Antarctic Circumpolar Current flow and a weak Atlantic meridional overturning circulation (AMOC). Subsequent Central American Seaway closure reinforces the AMOC while also stagnating equatorial Pacific subsurface waters. These gateway-derived oceanographic changes are reflected in large shifts to the global distribution of DIC. An initially closed Drake Passage results in high DIC concentrations in the Atlantic and Arctic oceans, and lower DIC concentrations in the Pacific/Indian/Southern oceans. Opening Drake Passage reverses this gradient by lowering mid-depth Atlantic and Arctic DIC concentrations and raising deep Pacific/Indian/Southern Ocean DIC concentrations. Central American Seaway closure further reinforces this trend through additional Atlantic mid-depth DIC decreases, as well as Pacific mid-depth DIC concentration increases, with the net effect being a transition to a modern distribution of oceanic DIC.« less

  7. Preharvest manual herbicide treatments for controlling American beech in Central West Virginia

    Treesearch

    Jeffery D. Kochenderfer; James N. Kochenderfer; David A. Warner; Gary W. Miller

    2004-01-01

    Application costs and efficacy were determined for manual preharvest herbicide treatments applied to control American beech (Fagus grandifolia Ehrh.) that was interfering with the establishment and development of black cherry (Prunus serotina Ehrh.) in central West Virginia. The treatments consisted of four levels of basal area...

  8. A comparison of two stem injection treatments applied to American beech in central West Virginia

    Treesearch

    Jeffrey D. Kochenderfer; Gary W. Miller; James N. Kochenderfer

    2012-01-01

    Efficacies for two herbicide stem injection treatments on American beech (Fagus grandifolia Ehrh.) and impacts to nontarget residual trees were evaluated in central West Virginia. The treatments consisted of hack-and-squirt injection of all beech stems ≥1.0 in. to 9.9 in. diameter at breast height (d.b.h.) with either imazapyr as Arsenal...

  9. Overweight and Perceived Health in Mexican American Children: A Pilot Study in a Central Texas Community

    ERIC Educational Resources Information Center

    Tyler, Diane O.

    2004-01-01

    This study assessed actual and perceived health status of overweight Mexican American clients at a central Texas school-based health center in a predominately Hispanic school district. It also explored the participants' interest in making lifestyle changes to promote a healthy weight. A medical records review indicated that of the Hispanic…

  10. 78 FR 57922 - American Energy Production, Inc., Best Energy Services, Inc., Community Central Bank Corporation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-20

    ... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE COMMISSION American Energy Production, Inc., Best Energy Services, Inc., Community Central Bank Corporation... accurate information concerning the securities of Best Energy Services, Inc. because it has not filed any...

  11. Legal Status and Educational Transitions for Mexican and Central American Immigrant Youth

    ERIC Educational Resources Information Center

    Greenman, Emily; Hall, Matthew

    2013-01-01

    This study uses the Survey of Income and Program Participation to infer the legal status of Mexican and Central American immigrant youth and to investigate its relationship with educational attainment. We assess differences by legal status in high school graduation and college enrollment, decompose differences in college enrollment into the…

  12. Field Wind Tunnel Testing of Two Silt Loam Soils in the North American Central High Plains

    USDA-ARS?s Scientific Manuscript database

    The change from conventional tillage to no-till cropping systems and the emergence of cropping systems with fewer and shorter fallow periods has resulted in reduced wind erosion on the North American Central High Plains. This reduction has been attributed primarily to increased surface coverage by ...

  13. Overweight and Perceived Health in Mexican American Children: A Pilot Study in a Central Texas Community

    ERIC Educational Resources Information Center

    Tyler, Diane O.

    2004-01-01

    This study assessed actual and perceived health status of overweight Mexican American clients at a central Texas school-based health center in a predominately Hispanic school district. It also explored the participants' interest in making lifestyle changes to promote a healthy weight. A medical records review indicated that of the Hispanic…

  14. Coresidence and Resistance: Strategies for Survival among Undocumented Mexicans and Central Americans in the United States.

    ERIC Educational Resources Information Center

    Chavez, Leo R.

    1990-01-01

    Examines variation in coresidence among undocumented Mexican and Central American immigrants in San Diego (California). Proposes that by creatively forming and reforming coresident groups, undocumented immigrants use social organization strategically and effectively as a resource to assist them in their struggle to live and work in the United…

  15. Low-Income Central American Immigrant Mothers' Goals and Their Children's Classroom Competencies in Preschool

    ERIC Educational Resources Information Center

    Denmark, Nicole Marie; Harden, Brenda Jones; Gonzalez, Maritza

    2014-01-01

    Research Findings: Unlike other Latino groups, there is little information about the early socialization of children from Central American (CA) immigrant families. This study examined CA immigrant mothers' short-term goals and the implications of these goals for children's behavior in preschool. A total of 47 low-income mothers described their…

  16. Un dia en la vida: The Everyday Activities of Young Children from Central American Immigrant Families

    ERIC Educational Resources Information Center

    Denmark, Nicole; Jones Harden, Brenda

    2012-01-01

    The aim of this article was to explore the everyday activities of young children from low-income Central American (CA) immigrant families. From the perspective that everyday activities propel children's development of culturally and contextually valued behaviours and skills, 48 mothers were interviewed regarding the activities that are available…

  17. Central American Refugees and U.S. High Schools. A Psychosocial Study of Motivation and Achievement.

    ERIC Educational Resources Information Center

    Suarez-Orozco, Marcelo M.

    This ethnographic study documents and interprets key school, work, and family life issues in the lives and experiences of a sampling of recent immigrants from the war-torn Central American nations; and suggests a psychocultural theory of achievement motivation. Information was gathered from observation in two urban high schools, interviews with 50…

  18. Impacts of Central American Fires on Ozone Air Quality in Texas

    NASA Astrophysics Data System (ADS)

    Wang, S. C.; Wang, Y.; Lei, R.; Talbot, R. W.

    2016-12-01

    Background ozone represents the portion of ozone level in one day that cannot be reduced by local emission controls. One of the important factors causing high background ozone events is wildfires. Satellite observations have documented frequent transport of wildfire smoke from Mexico and Central America to the southern US, particularly Texas, causing haze and exceedance of fine particle matters. However, the impact of those fires on background ozone in Texas is poorly understood. In this study, the effects of the Central America fire emissions in spring (Apr-May) from 2000 to 2013 on high background ozone events in Texas are investigated and quantified. We first examine through back trajectory analysis if any high background ozone days in cities of Texas such as Houston can be traced back to fire events in Central America. The GEOS-Chem global chemical transport model and its nested-grid version over North America are used to simulate the periods of the selected cases studies of Central American fires. Long-large transport of gaseous emissions (NOx, VOCs, and CO) from Central American fires are simulated and background ozone concentrations variations in Texas region due to those fire events are also quantified through the difference in model results with and without fire emissions in Central America. Finally, this study connects those fires and high background ozone events, and also quantifies the contribution of fire emissions from Central America on Texas ozone air quality.

  19. An Examination of the Relationship between Acculturation Level and PTSD among Central American Immigrants in the United States

    ERIC Educational Resources Information Center

    Sankey, Sarita Marie

    2010-01-01

    The purpose of this study was to examine the relationship between acculturation level and posttraumatic stress disorder (PTSD) prevalence in Central American immigrants in the United States. Central American immigrants represent a population that is a part of the Latino/Hispanic Diaspora in the United States. By the year 2050 the United States…

  20. Where American Indian Students Go to School: Enrollment in Seven Central Region States. REL 2016-113

    ERIC Educational Resources Information Center

    Apthorp, Helen S.

    2016-01-01

    This report provides descriptive information about the location and native language use of schools in the REL Central Region with high enrollment of American Indian students, whether Bureau of Indian Education schools or non-Bureau of Indian Education high-density American Indian schools (schools with 25 percent or more American Indian student…

  1. Central corneal thickness in Northwestern American Indians/Alaskan Natives and comparison with White and African-American persons.

    PubMed

    Torres, Rodrigo J; Jones, Emily; Edmunds, Beth; Becker, Thomas; Cioffi, George A; Mansberger, Steven L

    2008-11-01

    To determine the demographic factors associated with central corneal thickness (CCT) in Northwestern American Indians/Alaskan Natives (AI/ANs) and to compare these CCT measurements with those of White and African-American persons. Cross-sectional comparative, observational study. We performed ultrasonic pachymetry (DGH-500 Pachette; DGH Technologies, Exton, Pennsylvania, USA) on a random sample of AI/AN subjects from three randomly selected AI/AN tribes in the Northwest United States (n = 429). Pachymetry also was performed on a convenience sample of White (n = 46) and African-American (n = 33) persons. Our main outcome measure was the average of right and left eye CCT. Average AI/AN CCT was 554.8 +/- 33.9 microm. AI/AN CCT was found to be thicker than that of African Americans (528.5 +/- 33.2 microm) but similar to that of White persons (551.9 +/- 28.3 microm). CCT was greater in AI/AN females than in AI/AN males (557.6 +/- 33.3 microm vs 550.1 +/- 34.5 microm; P = .03). We found no difference in CCT based on percent AI/AN heritage, age, and keratometry readings. We found no significant differences in mean CCT between AI/ANs with glaucoma (556.2 microm) and those who did not have glaucoma (556.6 microm). CCT measurements for the Northwest AI/AN population are similar to those of White persons but thicker than those of African-American persons. Although glaucoma is common in AI/ANs, we did not find an association with thin CCT. We need future studies to explore the risk factors for glaucoma in AI/ANs.

  2. Central Corneal Thickness in Northwestern American Indian/Alaskan Natives and Comparison to White and African Americans

    PubMed Central

    Torres, Rodrigo J.; Jones, Emily; Edmunds, Beth; Becker, Thomas; Cioffi, George A.; Mansberger, Steven L.

    2008-01-01

    Purpose To determine the demographic factors associated with central corneal thickness (CCT) in Northwestern American Indian/Alaskan Natives (AI/AN), and compare these CCT measurements to white and African Americans. Design Cross-sectional comparative observational study. Methods We performed ultrasonic pachymetry (DGH-500 Pachette; DGH Technologies, Exton, PA.) on a random sample of AI/AN subjects from 3 randomly selected AI/AN tribes in the Northwest United States (n=429). Pachymetry was also performed on a convenience sample of white (n=46) and African Americans (n=33). Our main outcome measure was the average of right and left eye CCT. Results Average AI/AN CCT was 554.8 +/- 33.9 microns. AI/AN CCT was found to be thicker than African Americans (528.5 +/- 33.2) but similar to Whites (551.9 +/-28.3). CCT was greater in AI/AN females than males (557.6 +/- 33.3 vs. 550.1 +/- 34.5, p=0.03). We found no difference in CCT based on percent AIAN heritage, age, and keratometry readings. We found no significant differences in mean CCT between AI/AN with glaucoma (556.2 microns) and those who did not have glaucoma (556.6 microns). Conclusion CCT measurements for the Northwest AI/AN population are similar to those of Whites but thicker than those of African Americans. While glaucoma is common in AI/AN, we did not find an association with thin CCT. We need future studies to explore the risk factors for glaucoma in AI/AN. PMID:18672219

  3. [Ovarian activity of Agouti paca (Rodentia: Agoutidae) under captivity].

    PubMed

    Montes Pérez, Rubén C; Cabrera Baz, Elsy A

    2006-09-01

    The ovarian activity of Agouti paca was characterized by hormonal profiles and ovarian structures. Samples of blood were taken from eight females (seven adults and one juvenile) at the breeding grounds of the Facultad de Medicina Veterinaria y Zootecnia in Yucatśn, Mexico. Sampling lasted approximately two months and was done every three and six days. Blood was collected from anesthetized animals, and the levels of progesterone (P4) and 17 beta estradiol (E2) were analized by radioimmunoassay technique. Macroscopic and microscopic analyses were carried out in ovaries of dead animals. The estrous cycle lasted 29+/-8.4 days, levels of 1.61+/-0.65 ng/ml for P4 and 39+/-24 pg/ml for E2 were observed for a follicular phase, 6.18+/-3.70 ng/ml and 29+/-16 pg/ml for P4 and E2 respectively in the luteal phase. Statistically significant differences were found between phases for P4 but not for E2. The presence of extragonadal steroids with levels of P4 of 1.9+/-0.77 ng/ml and E2 of 22+/-17 pg/ml were observed, which are not produced by the effects of managing stress. The changes in the levels of P4 during the cycle are indicators of luteal activity, with the intersticial tissue acting probably as active steroids-producing gland. Follicular growth was observed during the entire cycle.

  4. Agouti sequence polymorphisms in coyotes, wolves and dogs suggest hybridization.

    PubMed

    Schmutz, Sheila M; Berryere, Thomas G; Barta, Jodi L; Reddick, Kimberley D; Schmutz, Josef K

    2007-01-01

    Domestic dogs have been shown to have multiple alleles of the Agouti Signal Peptide (ASIP) in exon 4 and we wished to determine the level of polymorphism in the common wild canids of Canada, wolves and coyotes, in comparison. All Canadian coyotes and most wolves have banded hairs. The ASIP coding sequence of the wolf did not vary from the domestic dog but one variant was detected in exon 4 of coyotes that did not alter the arginine at this position. Two other differences were found in the sequence flanking exon 4 of coyotes compared with the 45 dogs and 1 wolf. The coyotes also demonstrated a relatively common polymorphism in the 3' UTR sequence that could be used for population studies. One of the ASIP alleles (R96C) in domestic dogs causes a solid black coat color in homozygotes. Although some wolves are melanistic, this phenotype does not appear to be caused by this same mutation. However, one wolf, potentially a dog-wolf hybrid or descendant thereof, was heterozygous for this allele. Likewise 2 coyotes, potentially dog-coyote or wolf-coyote hybrid descendants, were heterozygous for the several polymorphisms in and flanking exon 4. We could conclude that these were coyote-dog hybrids because both were heterozygous for 2 mutations causing fawn coat color in dogs.

  5. Genetic divergence disclosing a rapid prehistorical dispersion of Native Americans in Central and South America.

    PubMed

    He, Yungang; Wang, Wei R; Li, Ran; Wang, Sijia; Jin, Li

    2012-01-01

    An accurate estimate of the divergence time between Native Americans is important for understanding the initial entry and early dispersion of human beings in the New World. Current methods for estimating the genetic divergence time of populations could seriously depart from a linear relationship with the true divergence for multiple populations of a different population size and significant population expansion. Here, to address this problem, we propose a novel measure to estimate the genetic divergence time of populations. Computer simulation revealed that the new measure maintained an excellent linear correlation with the population divergence time in complicated multi-population scenarios with population expansion. Utilizing the new measure and microsatellite data of 21 Native American populations, we investigated the genetic divergences of the Native American populations. The results indicated that genetic divergences between North American populations are greater than that between Central and South American populations. None of the divergences, however, were large enough to constitute convincing evidence supporting the two-wave or multi-wave migration model for the initial entry of human beings into America. The genetic affinity of the Native American populations was further explored using Neighbor-Net and the genetic divergences suggested that these populations could be categorized into four genetic groups living in four different ecologic zones. The divergence of the population groups suggests that the early dispersion of human beings in America was a multi-step procedure. Further, the divergences suggest the rapid dispersion of Native Americans in Central and South Americas after a long standstill period in North America.

  6. Genetic Divergence Disclosing a Rapid Prehistorical Dispersion of Native Americans in Central and South America

    PubMed Central

    He, Yungang; Wang, Wei R.; Li, Ran; Wang, Sijia; Jin, Li

    2012-01-01

    An accurate estimate of the divergence time between Native Americans is important for understanding the initial entry and early dispersion of human beings in the New World. Current methods for estimating the genetic divergence time of populations could seriously depart from a linear relationship with the true divergence for multiple populations of a different population size and significant population expansion. Here, to address this problem, we propose a novel measure to estimate the genetic divergence time of populations. Computer simulation revealed that the new measure maintained an excellent linear correlation with the population divergence time in complicated multi-population scenarios with population expansion. Utilizing the new measure and microsatellite data of 21 Native American populations, we investigated the genetic divergences of the Native American populations. The results indicated that genetic divergences between North American populations are greater than that between Central and South American populations. None of the divergences, however, were large enough to constitute convincing evidence supporting the two-wave or multi-wave migration model for the initial entry of human beings into America. The genetic affinity of the Native American populations was further explored using Neighbor-Net and the genetic divergences suggested that these populations could be categorized into four genetic groups living in four different ecologic zones. The divergence of the population groups suggests that the early dispersion of human beings in America was a multi-step procedure. Further, the divergences suggest the rapid dispersion of Native Americans in Central and South Americas after a long standstill period in North America. PMID:22970308

  7. Draft Public Health Statement on the U.S.-Central American Free Trade Agreement (CAFTA).

    PubMed

    2004-01-01

    The U.S. is rapidly negotiating a raft of new regional and bilateral trade agreements. The most recent agreement, with Central America, [was to] come before Congress for a vote as soon as late May. There is growing concern that international trade agreements threaten health care and the health of communities. . . . The Draft Public Health Statement on the U.S.-Central American Free Trade Agreement (CAFTA), developed by CPATH which planned a campaign around the issues, analyzes key provisions from the perspective of public health and suggests reframing the trade debate in terms of health.

  8. Disruption of the RIIβ subunit of PKA reverses the obesity syndrome of agouti lethal yellow mice

    PubMed Central

    Czyzyk, Traci A.; Sikorski, Maria A.; Yang, Linghai; McKnight, G. Stanley

    2008-01-01

    Agouti lethal yellow (Ay) mice express agouti ectopically because of a genetic rearrangement at the agouti locus. The agouti peptide is a potent antagonist of the melanocortin 4 receptor (MC4R) expressed in neurons, and this leads to hyperphagia, hypoactivity, and increased fat mass. The MC4R signals through Gs and is thought to stimulate the production of cAMP and activation of downstream cAMP effector molecules such as PKA. Disruption of the RIIβ regulatory subunit gene of PKA results in release of the active catalytic subunit and an increase in basal PKA activity in cells where RIIβ is highly expressed. Because RIIβ is expressed in neurons including those in the hypothalamic nuclei where MC4R is prominent we tested the possibility that the RIIβ knockout might rescue the body weight phenotypes of the Ay mice. Disruption of the RIIβ PKA regulatory subunit gene in mice leads to a 50% reduction in white adipose tissue and resistance to diet-induced obesity and hyperglycemia. The RIIβ mutation rescued the elevated body weight, hyperphagia, and obesity of Ay mice. Partial rescue of the Ay phenotypes was even observed on an RIIβ heterozygote background. These results suggest that the RIIβ gene mutation alters adiposity and locomotor activity by modifying PKA signaling pathways downstream of the agouti antagonism of MC4R in the hypothalamus. PMID:18172198

  9. Prevalence of HIV risk behaviors among undocumented Central American immigrant women in Houston, Texas.

    PubMed

    Montealegre, Jane R; Risser, Jan M; Selwyn, Beatrice J; McCurdy, Sheryl A; Sabin, Keith

    2012-08-01

    Undocumented Central American immigrants in the United States are disproportionately affected by HIV infection. However, epidemiological data on sexual behaviors among undocumented women are sparse and the extent to which behaviors vary by duration of residence in the U.S.is largely unknown. In 2010, we used respondent driven sampling to conduct an HIV behavioral survey among Central American immigrant women residing in Houston, Texas without a valid U.S. visa or residency papers. Here we describe the prevalence of sexual risk behaviors and compare recent (5 years or less in the U.S.) and established immigrants (over 5 years in the U.S.) to elucidate changes in sexual risk behaviors over time. Our data suggest that recent immigrants have less stable sexual partnerships than established immigrants, as they are more likely to have multiple and concurrent sexual partnerships, as well as partnerships of shorter duration.

  10. Development and characterization of microsatellite markers for Central American Begonia sect. Gireoudia (Begoniaceae)1

    PubMed Central

    Twyford, Alex D.; Ennos, Richard A.; Kidner, Catherine A.

    2013-01-01

    • Premise of the study: Transcriptome sequence data were used to design microsatellite primers for two widespread Central American Begonia species, B. heracleifolia and B. nelumbiifolia, to investigate population structure and hybridization. • Methods and Results: The transcriptome from vegetative meristem tissue from the related B. plebeja was mined for microsatellite loci, and 31 primer pairs amplified in the target species. Fifteen primer pairs were combined in two multiplex PCR reactions, which amplified an average of four alleles per locus. • Conclusions: The markers developed will be a valuable genetic resource for medium-throughput genotyping of Central American species of Begonia sect. Gireoudia. A subset of these markers have perfect sequence matches to Asian B. venusta, and are promising for studies in other Begonia sections. PMID:25202548

  11. Immigration Enforcement, Parent-Child Separations, and Intent to Remigrate by Central American Deportees.

    PubMed

    Amuedo-Dorantes, Catalina; Pozo, Susan; Puttitanun, Thitima

    2015-12-01

    Given the unprecedented increase in the flow of migrants from El Salvador, Guatemala, and Honduras to the United States, this article analyzes the impact of U.S. interior enforcement on parent-child separations among Central American deportees, along with its implications for deportees' intentions to remigrate to the United States. Using the EMIF sur survey data, we find that interior enforcement raises the likelihood of parent-child separations as well as the likelihood that parents forcedly separated from their young children report the intention to return to the United States, presumably without documents. By increasing parent-child separations, interior enforcement could prove counterproductive in deterring repetitive unauthorized crossings among Central American deportees.

  12. Determinants of female and male condom use among immigrant women of Central American descent.

    PubMed

    Salabarría-Peña, Yamir; Lee, Jerry W; Montgomery, Susanna B; Hopp, Helen W; Muralles, Arnulfo A

    2003-06-01

    This study was designed to determine factors that influence female and male condom use among Central American women, applying the theory of planned behavior. A cross-sectional design was employed and a sample of 175 Central American women, 18-50 years old, was recruited from a community-based clinic in Los Angeles County. Participants in this study were interviewed face-to-face. Attitude, subjective norm, and perceived behavioral control explained 41% and 45% of the variation in the intention to use male and female condoms, respectively. Respondents' friends and mothers influenced their subjective norms. Beliefs regarding sexual sensation and sexually transmitted infection/pregnancy prevention affected respondents' attitudes toward condoms. Trust issues were also a major factor affecting attitudes toward female condoms. Condom use and sex negotiation skills predicted control over condoms. Results of this study can be used to design HIV/AIDS prevention programs that help women feel control over condom use and their sexual behavior.

  13. Prenatal risk factors among foreign-born Central American women: a comparative study.

    PubMed

    Gaffney, K F

    2000-01-01

    The purpose of this study was to compare the incidence of empirically established prenatal risk factors for low birthweight (LBW) outcomes among two groups of low-income mothers: foreign-born Central American women and nonimmigrant, non-Hispanic women. Two hundred ninety-six women who were part of a larger study of maternal role sufficiency were included in the present study: 127 Central American women and 169 nonimmigrant, non-Hispanic women who identified themselves as Black (n = 59) or White (n = 110). Data were collected by public health nurses (PHNs) during home visits and by research nurses in prenatal health department clinics. Comparisons were made between the two groups in areas of demographic characteristics, prenatal health behaviors, and prenatal stressful life-events. Foreign-born Central American mothers were found to be less educated, more likely to be living with their partners, less likely to engage in prenatal health risk behaviors, and less likely to identify stressors in their lives. The initiation of prenatal PHN services by the target group was similar to the comparison group. Their rate of LBW deliveries did not reflect the protective effect often attributed to foreign-born Hispanic mothers. Findings are discussed in light of the paradox of LBW and Hispanic heritage. Recommendations for practice, clinical research, and public policy are also addressed.

  14. Modeling Central American Volcanic Front Primitive Lavas with the Arc Basalt Simulator (abs 4.0)

    NASA Astrophysics Data System (ADS)

    Feigenson, M.; Carr, M. J.; Gazel, E.

    2012-12-01

    We have used the Arc Basalt Simulator (ABS), developed by J-I Kimura, to explore the conditions and components of melting beneath the Central American volcanic front. ABS is a comprehensive forward model that incorporates slab dehydration and melting and mantle wedge fluxing and melting using realistic P-T conditions and experimentally determined phase relations and partition coefficients. We have applied ABS version 4.00, which includes melting/dehydration relations in eight distinct subducting layers, to model representative magma types along the Central American volcanic front. These magmas are first projected to primary melt compositions by the addition of olivine until they reach Fo90. Then, using a wide range of input parameters including variations in slab components, extent of peridotite depletion, depth of slab dehydration and wedge fluxing and degree of peridotite melting, successful model fits are generated (based on trace element and isotope matching). The solution space is probed using a Monte Carlo technique to cover the enormous range of parameter values. Nicaragua and Costa Rica represent geochemical and geophysical end members of the volcanic front, differing greatly in volcano volume, slab dip beneath the volcano, isotopic composition and incompatible element enrichment. Using appropriate input compositions for ABS 4.0, we find through millions of simulations that the Cerro Negro primary magma (Nicaragua) requires high degrees of source melting (22-27%) and large amounts of slab-derived water (3-5%). In contrast, the Irazu primary magma (central Costa Rica) is generated from more enriched sources with only a small amount of water (less than 0.5%) and at low degrees of partial melting (less than 5%). Other Central American lavas with intermediate geochemical characteristics are produced from conditions within the Nicaragua-Costa Rica range. By reproducing the lava geochemistry with ABS 4.0, it becomes possible to extract constraints on source input

  15. Prehistoric earthquakes on the Caribbean-South American plate boundary, central Range Fault, Trinidad

    USGS Publications Warehouse

    Prentice, Carol S.; Crosby, Christopher J.; Weber, John C.; Ragona, Daniel

    2010-01-01

    Recent geodetic studies suggest that the Central Range fault is the principal plate-boundary structure accommodating strike-slip motion between the Caribbean and South American plates. Our study shows that the fault forms a topographically prominent lineament in central Trinidad. Results from a paleoseismic investigation at a site where Holocene sediments have been deposited across the Central Range fault indicate that it ruptured the ground surface most recently between 2710 and 550 yr B.P. If the geodetic slip rate of 9–15 mm/yr is representative of Holocene slip rates, our paleoseismic data suggest that at least 4.9 m of potential slip may have accumulated on the fault and could be released during a future large earthquake (M > 7).

  16. Prehistoric earthquakes on the Caribbean-South American plate boundary, central range fault, Trinidad

    USGS Publications Warehouse

    Prentice, C.S.; Weber, J.C.; Crosby, C.J.; Ragona, D.

    2010-01-01

    Recent geodetic studies suggest that the Central Range fault is the principal plate-boundary structure accommodating strike-slip motion between the Caribbean and South American plates. Our study shows that the fault forms a topographically prominent lineament in central Trinidad. Results from a paleoseismic investigation at a site where Holocene sediments have been deposited across the Central Range fault indicate that it ruptured the ground surface most recently between 2710 and 550 yr B.P. If the geodetic slip rate of 9-15 mm/yr is representative of Holocene slip rates, our paleoseismic data suggest that at least 4.9 m of potential slip may have accumulated on the fault and could be released during a future large earthquake (M > 7). ?? 2010 Geological Society of America.

  17. Academic Race Stereotypes, Academic Self-Concept, and Racial Centrality in African American Youth.

    PubMed

    Okeke, Ndidi A; Howard, Lionel C; Kurtz-Costes, Beth; Rowley, Stephanie J

    2009-08-01

    The relation between academic race stereotype endorsement and academic self-concept was examined in two studies of seventh- and eighth-grade African Americans. Based on expectancy-value theory, the authors hypothesized that academic race stereotype endorsement would be negatively related to self-perceptions. Furthermore, it was anticipated that the relation between stereotype endorsement and self-perceptions would be moderated by racial centrality. The hypothesis was supported in two independent samples. Among students with high racial centrality, endorsement of traditional race stereotypes was linked to lower self-perceptions of academic competence. The stereotype/self-concept relation was nonsignificant among youth for whom race was less central to their identities. These results confirm the supposition of expectancy-value theory and illustrate the interweaving of group and individual identity with motivational beliefs.

  18. Ectopic expression of the agouti gene in transgenic mice causes obesity, features of type II diabetes, and yellow fur.

    PubMed

    Klebig, M L; Wilkinson, J E; Geisler, J G; Woychik, R P

    1995-05-23

    Mice that carry the lethal yellow (Ay) or viable yellow (Avy) mutation, two dominant mutations of the agouti (a) gene in mouse chromosome 2, exhibit a phenotype that includes yellow fur, marked obesity, a form of type II diabetes associated with insulin resistance, and an increased susceptibility to tumor development. Molecular analyses of these and several other dominant "obese yellow" a-locus mutations suggested that ectopic expression of the normal agouti protein gives rise to this complex pleiotropic phenotype. We have now tested this hypothesis directly by generating transgenic mice that ectopically express an agouti cDNA clone encoding the normal agouti protein in all tissues examined. Transgenic mice of both sexes have yellow fur, become obese, and develop hyperinsulinemia. In addition, male transgenic mice develop hyperglycemia by 12-20 weeks of age. These results demonstrate conclusively that the ectopic agouti expression is responsible for most, if not all, of the phenotypic traits of the dominant, obese yellow mutants.

  19. Transient ectopic overexpression of agouti-signalling protein 1 (asip1) induces pigment anomalies in flatfish.

    PubMed

    Guillot, Raúl; Ceinos, Rosa Maria; Cal, Rosa; Rotllant, Josep; Cerdá-Reverter, José Miguel

    2012-01-01

    While flatfish in the wild exhibit a pronounced countershading of the dorso-ventral pigment pattern, malpigmentation is commonly observed in reared animals. In fish, the dorso-ventral pigment polarity is achieved because a melanization inhibition factor (MIF) inhibits melanoblast differentiation and encourages iridophore proliferation in the ventrum. A previous work of our group suggested that asip1 is the uncharacterized MIF concerned. In order to further support this hypothesis, we have characterized asip1 mRNAs in both turbot and sole and used deduced peptide alignments to analyze the evolutionary history of the agouti-family of peptides. The putative asip precursors have the characteristics of a secreted protein, displaying a putative hydrophobic signal. Processing of the potential signal peptide produces mature proteins that include an N-terminal region, a basic central domain with a high proportion of lysine residues as well as a proline-rich region that immediately precedes the C-terminal poly-cysteine domain. The expression of asip1 mRNA in the ventral area was significantly higher than in the dorsal region. Similarly, the expression of asip1 within the unpigmented patches in the dorsal skin of pseudoalbino fish was higher than in the pigmented dorsal regions but similar to those levels observed in the ventral skin. In addition, the injection/electroporation of asip1 capped mRNA in both species induced long term dorsal skin paling, suggesting the inhibition of the melanogenic pathways. The data suggest that fish asip1 is involved in the dorsal-ventral pigment patterning in adult fish, where it induces the regulatory asymmetry involved in precursor differentiation into mature chromatophore. Adult dorsal pseudoalbinism seems to be the consequence of the expression of normal developmental pathways in an inaccurate position that results in unbalanced asip1 production levels. This, in turn, generates a ventral-like differentiation environment in dorsal regions.

  20. Transient Ectopic Overexpression of Agouti-Signalling Protein 1 (Asip1) Induces Pigment Anomalies in Flatfish

    PubMed Central

    Cal, Rosa; Rotllant, Josep; Cerdá-Reverter, José Miguel

    2012-01-01

    While flatfish in the wild exhibit a pronounced countershading of the dorso-ventral pigment pattern, malpigmentation is commonly observed in reared animals. In fish, the dorso-ventral pigment polarity is achieved because a melanization inhibition factor (MIF) inhibits melanoblast differentiation and encourages iridophore proliferation in the ventrum. A previous work of our group suggested that asip1 is the uncharacterized MIF concerned. In order to further support this hypothesis, we have characterized asip1 mRNAs in both turbot and sole and used deduced peptide alignments to analyze the evolutionary history of the agouti-family of peptides. The putative asip precursors have the characteristics of a secreted protein, displaying a putative hydrophobic signal. Processing of the potential signal peptide produces mature proteins that include an N-terminal region, a basic central domain with a high proportion of lysine residues as well as a proline-rich region that immediately precedes the C-terminal poly-cysteine domain. The expression of asip1 mRNA in the ventral area was significantly higher than in the dorsal region. Similarly, the expression of asip1 within the unpigmented patches in the dorsal skin of pseudoalbino fish was higher than in the pigmented dorsal regions but similar to those levels observed in the ventral skin. In addition, the injection/electroporation of asip1 capped mRNA in both species induced long term dorsal skin paling, suggesting the inhibition of the melanogenic pathways. The data suggest that fish asip1 is involved in the dorsal-ventral pigment patterning in adult fish, where it induces the regulatory asymmetry involved in precursor differentiation into mature chromatophore. Adult dorsal pseudoalbinism seems to be the consequence of the expression of normal developmental pathways in an inaccurate position that results in unbalanced asip1 production levels. This, in turn, generates a ventral-like differentiation environment in dorsal regions

  1. Oral Health and Dental Care in Older Asian Americans in Central Texas.

    PubMed

    Jang, Yuri; Yoon, Hyunwoo; Park, Nan Sook; Chiriboga, David A

    2017-07-01

    To examine factors associated with dental health insurance, self-rated oral health, and use of preventive dental care services in older Asian Americans. Cross-sectional survey. The Asian American Quality of Life Survey was conducted with 2,614 Asian Americans living in central Texas using questionnaires available in English and six Asian languages. Asian American Quality of Life Survey participants aged 60 and older (N = 533; mean age = 69.4 ± 6.9). Participants were asked whether they had insurance that covered the cost of any dental visit, how they would rate their overall oral health status, and whether they had visited a dental clinic for a routine examination in the past 12 months. Information was also collected on sociodemographic and immigration-related variables. More than 61% of the sample had no dental health insurance, 45% reported that their oral health was fair or poor, and 44% had not used preventive dental care services. A series of logistic regression analyses identified factors posing a significant risk to oral health and dental care. For example, those with limited English proficiency were 3.5 times as likely to lack dental health insurance and 3.2 times as likely to rate their oral health as fair or poor. The odds of not using preventive dental care services were 6.4 times as great in those without dental health insurance. The overall findings call attention to efforts to promote oral health and dental care in older Asian Americans. © 2017, Copyright the Authors Journal compilation © 2017, The American Geriatrics Society.

  2. Sex-related differences in habitat associations of wintering American Kestrels in California's Central Valley

    USGS Publications Warehouse

    Pandolfino, E.R.; Herzog, M.P.; Smith, Z.

    2011-01-01

    We used roadside survey data collected from 19 routes over three consecutive winters from 200708 to 200910 to compare habitat associations of male and female American Kestrels (Falco sparverius) in the Central Valley of California to determine if segregation by sex was evident across this region. As a species, American Kestrels showed positive associations with alfalfa and other forage crops like hay and winter wheat, as well as grassland, irrigated pasture, and rice. Habitat associations of females were similar, with female densities in all these habitats except rice significantly higher than average. Male American Kestrels showed a positive association only with grassland and were present at densities well below those of females in alfalfa, other forage crops, and grassland. Males were present in higher densities than females in most habitats with negative associations for the species, such as orchards, urbanized areas, and oak savannah. The ratio of females to males for each route was positively correlated with the overall density of American Kestrels on that route. Our findings that females seem to occupy higher quality habitats in winter are consistent with observations from elsewhere in North America. ?? 2011 The Raptor Research Foundation, Inc.

  3. Organogenesis and foetal haemodynamics during the normal gestation of healthy black-rumped agoutis (Dasyprocta prymnolopha, Wagler, 1831) bred in captivity.

    PubMed

    Sousa, Fca; Pessoa, G T; Moura, L S; Araújo, J R; Rodrigues, Rps; Barbosa, Maps; Diniz, A N; Souza, A B; Silva, E G; Lucena, L U; Sanches, M P; Silva-Filho, O F; Guerra, P C; Sousa, J M; Neves, W C; Alves, F R

    2017-02-01

    The objective of this study was to define the patterns of organogenesis and foetal haemodynamics during the normal gestation of healthy agoutis (Dasyprocta prymnolopha) kept in captivity. Thirty pregnant agoutis that ranged in size from small to medium and weighed between 2.5 and 3 kg underwent B-mode and Doppler ultrasonography for the biometric evaluation of the foetal organs. The foetal aortic blood flow proved to be predominantly systolic, and the measured flow velocity was 78.89 ± 2.95 cm/s, with a maximum pressure gradient of 2.12 ± 0.27 mmHg. The liver was characterized by its large volume, occupying the entire cranial aspect of the abdominal cavity, and it was associated cranially with the diaphragm and caudally with the stomach. The flow velocity in the portal vein was estimated to equal 12.17 ± 2.37 cm/s, with a resistivity index of 0.82 ± 0.05. The gallbladder was centrally located and protruded cranially towards the diaphragm. The spleen was visualized as an elongated structure with tapered cranial and caudal extremities, and the foetal kidneys were visualized bilaterally in the retroperitoneal region, with the right kidney positioned slightly more cranially than the left. The morphological characterization and hemodynamic analysis of the foetal organs of black-rumped agoutis via B-mode and Doppler ultrasonography allow determination of the vascular network and of reference values for the blood flow required for perfusing the anatomical elements essential for maintaining the viability of foetuses at different gestational ages. © 2016 Blackwell Verlag GmbH.

  4. Plastid DNA sequencing and nuclear SNP genotyping help resolve the puzzle of central American Platanus

    PubMed Central

    De Castro, Olga; Di Maio, Antonietta; Lozada García, José Armando; Piacenti, Danilo; Vázquez-Torres, Mario; De Luca, Paolo

    2013-01-01

    Background and Aims Recent research on the history of Platanus reveals that hybridization phenomena occurred in the central American species. This study has two goals: to help resolve the evolutive puzzle of central American Platanus, and to test the potential of real-time polymerase chain reaction (PCR) for detecting ancient hybridization. Methods Sequencing of a uniparental plastid DNA marker [psbA-trnH(GUG) intergenic spacer] and qualitative and quantitative single nucleotide polymorphism (SNP) genotyping of biparental nuclear ribosomal DNA (nrDNA) markers [LEAFY intron 2 (LFY-i2) and internal transcribed spacer 2 (ITS2)] were used. Key Results Based on the SNP genotyping results, several Platanus accessions show the presence of hybridization/introgression, including some accessions of P. rzedowskii and of P. mexicana var. interior and one of P. mexicana var. mexicana from Oaxaca (= P. oaxacana). Based on haplotype analyses of the psbA-trnH spacer, five haplotypes were detected. The most common of these is present in taxa belonging to P. orientalis, P. racemosa sensu lato, some accessions of P. occidentalis sensu stricto (s.s.) from Texas, P. occidentalis var. palmeri, P. mexicana s.s. and P. rzedowskii. This is highly relevant to genetic relationships with the haplotypes present in P. occidentalis s.s. and P. mexicana var. interior. Conclusions Hybridization and introgression events between lineages ancestral to modern central and eastern North American Platanus species occurred. Plastid haplotypes and qualitative and quantitative SNP genotyping provide information critical for understanding the complex history of Mexican Platanus. Compared with the usual molecular techniques of sub-cloning, sequencing and genotyping, real-time PCR assay is a quick and sensitive technique for analysing complex evolutionary patterns. PMID:23798602

  5. Early development of the south Central American margin: mechanisms and tectonic implications

    NASA Astrophysics Data System (ADS)

    Buchs, D. M.; Baumgartner, P. O.; Arculus, R.; Montes, C.; Bayona, G.; Cardona, A.

    2012-04-01

    The south Central American margin forms the SW border of the Caribbean Plate on top of the subducting Cocos and Nazca Plates between Nicaragua and Colombia. New and previous tectonostratigraphic, age and geochemical results show that the forearc basement between south Costa Rica and east Panama is composed of autochthonous and accreted sequences that provide important constraints on the development of the south Central American margin, the evolution of the Caribbean Plate and the formation of an inter-American land bridge. Autochtonous sequences in the forearc include three tectonostratigraphic units that occur at a regional scale: (1) a Late Cretaceous oceanic plateau considered to represent an extension of the Caribbean Large Igneous Province (CLIP) at the base of the arc; (2) Late Campanian to Maastrichtian protoarc sequences that cover or intrude the oceanic plateau; and (3) Maastrichtian to Eocene sequences of a more mature volcanic arc that overlies or intrude preceding units. These units clearly indicate that subduction initiation along the margin and, thus, the birth of the Caribbean Plate occurred in the Campanian. Incipient subduction was possibly triggered or facilitated by contrasted lithospheric strength across the edge of the CLIP and collision between the CLIP and South America during westward migration of South America. Accreted sequences in the forearc include mostly Late Cretaceous to Eocene seamount fragments between south Costa Rica and west Panama, with additional Eocene to Miocene olistostromal and hemipelagic sediments in south Costa Rica. The age and tectonostratigraphic relationships of accreted sequences, autochtonous sequences, and overlying forearc slope sediment suggest that subduction erosion, punctuated by local seamount or sediment accretion was the dominant process controlling the evolution of the outer margin at least until the Miocene. A major tectonic event affected the margin in the Middle Eocene, which is indicated by a

  6. Chronic kidney disease in Central American agricultural communities: challenges for epidemiology and public health.

    PubMed

    Silva, Luis Carlos; Ordúñez, Pedro

    2014-04-01

    This paper contextualizes the chronic kidney disease epidemic and related burden of disease affecting Central American farming communities. It summarizes the two main causal hypotheses (heat stress and agrochemicals), draws attention to the consequences of dichotomous reasoning concerning causality, and warns of potential conflicts of interest and their role in "manufacturing doubt." It describes some methodological errors that compromise past study findings and cautions against delaying public health actions until a conclusive understanding is reached about the epidemic's causes and underlying mechanisms. It makes the case for a comprehensive approach to the historical, social and epidemiological facts of the epidemic, for critically assessing existing studies and for enhanced rigor in new research.

  7. [Diagnostic studies in the planning process of human resources: the Central American experience].

    PubMed

    de Canales, F; Martínez Chopen, O; Tercero Talavera, I; González, G

    1987-01-01

    In this paper the authors analyze various aspects of one of the essential stages in the process of planning human resources--diagnostic studies and research which will serve as a starting point. They stress the role of diagnostic personnel studies in formulating human resources policies and planning, and describe the phases to be followed in their execution, according to the results obtained in the three Central American countries (Guatemala, Honduras, and Nicaragua) in which the studies were completed. The paper concludes with a summary of the process in the three countries.

  8. [Towards the elimination of the transmission of Trypanosoma cruzi in Honduras and Central American countries].

    PubMed

    Ponce, C

    1999-01-01

    Central America is composed of seven countries: Belice, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua and Panama. Chagas disease exists in all seven countries, but with major prevalence in El Salvador, Guatemala, Honduras and Nicaragua. The main species of triatomine vectors are: Rhodnius prolixus, Triatoma dimidiata y Rhodnius pallescens. In 1997 the Central American countries launched an Initiative for the Vectorial and Transfusion Transmission Control of Chagas disease. The objectives of the Initiative are: 1. elimination of Rhodnius prolixus, 2. control of Triatoma dimidiata and 3. serological screening for Trypanosoma cruzi of 100% of the blood donors. This Initiative is supported by the Resolution for "The Elimination of Transmission of Chagas Disease", of the World Health Assembly in 1998.

  9. Lower Miocene Stratigraphy along the Panama Canal and Its Bearing on the Central American Peninsula

    PubMed Central

    Kirby, Michael Xavier; Jones, Douglas S.; MacFadden, Bruce J.

    2008-01-01

    Before the formation of the Central American Isthmus, there was a Central American Peninsula. Here we show that southern Central America existed as a peninsula as early as 19 Ma, based on new lithostratigraphic, biostratigraphic and strontium chemostratigraphic analyses of the formations exposed along the Gaillard Cut of the Panama Canal. Land mammals found in the Miocene Cucaracha Formation have similar body sizes to conspecific taxa in North America, indicating that there existed a terrestrial connection with North America that allowed gene flow between populations during this time. How long did this peninsula last? The answer hinges on the outcome of a stratigraphic dispute: To wit, is the terrestrial Cucaracha Formation older or younger than the marine La Boca Formation? Previous stratigraphic studies of the Panama Canal Basin have suggested that the Cucaracha Formation lies stratigraphically between the shallow-marine Culebra Formation and the shallow-to-upper-bathyal La Boca Formation, the latter containing the Emperador Limestone. If the La Boca Formation is younger than the Cucaracha Formation, as many think, then the peninsula was short-lived (1–2 m.y.), having been submerged in part by the transgression represented by the overlying La Boca Formation. On the other hand, our data support the view that the La Boca Formation is older than the Cucaracha Formation. Strontium dating shows that the La Boca Formation is older (23.07 to 20.62 Ma) than both the Culebra (19.83–19.12 Ma) and Cucaracha (Hemingfordian to Barstovian North American Land Mammal Ages; 19–14 Ma) formations. The Emperador Limestone is also older (21.24–20.99 Ma) than the Culebra and Cucaracha formations. What has been called the “La Boca Formation” (with the Emperador Limestone), is re-interpreted here as being the lower part of the Culebra Formation. Our new data sets demonstrate that the main axis of the volcanic arc in southern Central America more than likely existed as a

  10. Lower Miocene stratigraphy along the Panama Canal and its bearing on the Central American Peninsula.

    PubMed

    Kirby, Michael Xavier; Jones, Douglas S; MacFadden, Bruce J

    2008-07-30

    Before the formation of the Central American Isthmus, there was a Central American Peninsula. Here we show that southern Central America existed as a peninsula as early as 19 Ma, based on new lithostratigraphic, biostratigraphic and strontium chemostratigraphic analyses of the formations exposed along the Gaillard Cut of the Panama Canal. Land mammals found in the Miocene Cucaracha Formation have similar body sizes to conspecific taxa in North America, indicating that there existed a terrestrial connection with North America that allowed gene flow between populations during this time. How long did this peninsula last? The answer hinges on the outcome of a stratigraphic dispute: To wit, is the terrestrial Cucaracha Formation older or younger than the marine La Boca Formation? Previous stratigraphic studies of the Panama Canal Basin have suggested that the Cucaracha Formation lies stratigraphically between the shallow-marine Culebra Formation and the shallow-to-upper-bathyal La Boca Formation, the latter containing the Emperador Limestone. If the La Boca Formation is younger than the Cucaracha Formation, as many think, then the peninsula was short-lived (1-2 m.y.), having been submerged in part by the transgression represented by the overlying La Boca Formation. On the other hand, our data support the view that the La Boca Formation is older than the Cucaracha Formation. Strontium dating shows that the La Boca Formation is older (23.07 to 20.62 Ma) than both the Culebra (19.83-19.12 Ma) and Cucaracha (Hemingfordian to Barstovian North American Land Mammal Ages; 19-14 Ma) formations. The Emperador Limestone is also older (21.24-20.99 Ma) than the Culebra and Cucaracha formations. What has been called the "La Boca Formation" (with the Emperador Limestone), is re-interpreted here as being the lower part of the Culebra Formation. Our new data sets demonstrate that the main axis of the volcanic arc in southern Central America more than likely existed as a peninsula

  11. Biogeography and evolution of a widespread Central American lizard species complex: Norops humilis, (Squamata: Dactyloidae).

    PubMed

    Phillips, John G; Deitloff, Jennifer; Guyer, Craig; Huetteman, Sara; Nicholson, Kirsten E

    2015-07-19

    Caribbean anole lizards (Dactyloidae) have frequently been used as models to study questions regarding biogeography and adaptive radiations, but the evolutionary history of Central American anoles (particularly those of the genus Norops) has not been well studied. Previous work has hypothesized a north-to-south dispersal pattern of Central American Norops, but no studies have examined dispersal within any Norops lineages. Here we test two major hypotheses for the dispersal of the N. humilis/quaggulus complex (defined herein, forming a subset within Savage and Guyer's N. humilis group). Specimens of the N. humilis group were collected in Central America, from eastern Mexico to the Canal Zone of Panama. Major nodes were dated for comparison to the geologic history of Central America, and ancestral ranges were estimated for the N. humilis/quaggulus complex to test hypothesized dispersal patterns. These lineages displayed a northward dispersal pattern. We also demonstrate that the N. humilis/quaggulus complex consists of a series of highly differentiated mitochondrial lineages, with more conserved nuclear evolution. The paraphyly of the N. humilis species group is confirmed. A spatial analysis of molecular variance suggests that current populations are genetically distinct from one another, with limited mitochondrial gene flow occurring among sites. The observed south-to-north colonization route within the Norops humilis/quaggulus complex represents the first evidence of a Norops lineage colonizing in a south-to-north pattern, (opposite to the previously held hypothesis for mainland Norops). One previously described taxon (N. quaggulus) was nested within N. humilis, demonstrating the paraphyly of this species; while our analyses also reject the monophyly of the Norops humilis species group (sensu Savage and Guyer), with N. tropidonotus, N. uniformis, and N. marsupialis being distantly related to/highly divergent from the N. humilis/quaggulus complex. Our work sheds

  12. A missense mutation in the agouti signaling protein gene (ASIP) is associated with the no light points coat phenotype in donkeys.

    PubMed

    Abitbol, Marie; Legrand, Romain; Tiret, Laurent

    2015-04-08

    Seven donkey breeds are recognized by the French studbook and are characterized by a black, bay or grey coat colour including light cream-to-white points (LP). Occasionally, Normand bay donkeys give birth to dark foals that lack LP and display the no light points (NLP) pattern. This pattern is more frequent and officially recognized in American miniature donkeys. The LP (or pangare) phenotype resembles that of the light bellied agouti pattern in mouse, while the NLP pattern resembles that of the mammalian recessive black phenotype; both phenotypes are associated with the agouti signaling protein gene (ASIP). We used a panel of 127 donkeys to identify a recessive missense c.349 T > C variant in ASIP that was shown to be in complete association with the NLP phenotype. This variant results in a cysteine to arginine substitution at position 117 in the ASIP protein. This cysteine is highly-conserved among vertebrate ASIP proteins and was previously shown by mutagenesis experiments to lie within a functional site. Altogether, our results strongly support that the identified mutation is causative of the NLP phenotype. Thus, we propose to name the c.[349 T > C] allele in donkeys, the a(nlp) allele, which enlarges the panel of coat colour alleles in donkeys and ASIP recessive loss-of-function alleles in animals.

  13. The Central American Seaway and the Late Neogene ocean conveyor belt

    NASA Astrophysics Data System (ADS)

    Schneider, Birgit; Krebs-Kanzow, Uta; Park, Wonsun

    2013-04-01

    'The great ocean conveyor belt' depicts the large scale exchange of water mass properties between today's oceans. Over the past million years the tectonic evolution of ocean passages altered this pan-oceanic communication. The last such tectonic transformation was the closure of the Central American Seaway (CAS) which represented a low latitude gateway between Pacific and Atlantic prior to 4 million years ago. We use a coupled general circulation model and configure the topography for the past. The Central American Seaway modifies the global ocean circulation and the ocean conveyor belt which implies drastic changes in water mass properties and inter basin heat and freshwater transports. Compared to an experiment with modern basin geometry, a 1000-meter deep passage at the location of today's Isthmus of Panama results in a fundamental change in the warm water route of the conveyor belt while the cold path remains qualitatively unchanged. A transport of 10 Sv from Pacific to Atlantic is associated with the meridional transport in the South Atlantic changing from 10Sv northward to 2 Sv southward. Both Indonesian throughflow and export of warm water from the Indian Ocean across 30S are reduced by about 7 Sv. Analysing transports in density classes we are able to propose a sketch of the late Neogene conveyor belt.

  14. Housing and neighborhood quality among undocumented Mexican and Central American immigrants

    PubMed Central

    Hall, Matthew; Greenman, Emily

    2013-01-01

    Extensive research has documented the challenges that undocumented immigrants face in navigating U.S. labor markets, but relatively little has explored the impact of legal status on residential outcomes despite their widespread repercussions for social well-being. Using data from the 1996–2008 panels of the Survey of Income and Program Participation to impute documentation status among Mexican and Central American immigrants, we examine group differences in residential outcomes, including homeownership, housing crowding, satisfaction with neighborhood and housing quality, problems with neighborhood crime/safety, governmental services, and environmental issues, and deficiencies with housing units. Results from our analysis indicate that undocumented householders are far less likely to be homeowners than documented migrants, and also live in more crowded homes, report greater structural deficiencies with their dwellings, and express greater concern about the quality of public services and environmental conditions in their neighborhoods. In comparison to native whites, undocumented migrants’ residential circumstances are lacking, but their residential outcomes tend to be superior to those of native-born blacks. Overall, our results highlight the pervasive impact of legal status on stratifying Mexicans’ and Central Americans’ prospects for successful incorporation, but also underscore the rigidity of the black/nonblack divide structuring American residential contexts. PMID:24090862

  15. Central American Gyres, Tropical Cyclones, and Heavy Eastern U.S. Rainfall

    NASA Astrophysics Data System (ADS)

    Bosart, L. F.; Griffin, K. S.; Papin, P. P.; Torn, R. D.

    2012-12-01

    Between late summer and mid-autumn, broad low-level cyclonic circulations with spatial scales of 1000-2000 km can develop over Central America on time scales of 1-2 days and persist for 3-5 days. These broad cyclonic circulation regions, which hereafter we will call gyres, can absorb westward-moving tropical cyclones (TCs) from the east (e.g., Matthew in September 2010), disgorge cyclonic circulations to the northeast that later develop into TCs (e.g., Nicole in September 2010), interact with remnant southward-moving cold fronts to encourage weak TC development (e.g., TC Nate in October 2011), or enable weak eastern Pacific tropical depressions (TDs) to make landfall in Central America (e.g., TD 12-E in October 2011). A distinguishing feature of a Central American gyre is that it can be directly associated with exceptionally heavy rainfall and damaging regional flooding, such as occurred in conjunction with the landfall of TD 12-E and TC Nate. Similarly, a deep poleward tropical moisture transport from a Central American gyre in response to amplified midlatitude flow can lead to flooding rains in midlatitudes such as occurred along the Atlantic coast in conjunction with TC Lee in September 2011. This presentation will focus on the large-scale flow contribution to the formation of a well-defined Central American gyre in late September 2010 during the PREDICT field experiment and the subsequent impact of the gyre on the midlatitude flow and weather over eastern North America. The gyre formed when a strong east-west oriented cyclonic shear zone that separated anomalous tropical westerlies in the eastern Pacific from anomalous tropical easterlies over the Caribbean and North Atlantic was disrupted by northerly flow across the Isthmus of Tehuantepec gap (Chivela Pass) into the tropical Pacific. Initially, anomalous easterly flow from the Caribbean that was deflected southward by higher terrain to the west provided the initial source of northerly flow through the gap

  16. Oro-facial injuries in Central American and Caribbean sports games: a 20-year experience.

    PubMed

    Amy, Enrique

    2005-06-01

    Dental services in sports competitions in the Games sponsored by the International Olympic Committee are mandatory. In every Central American, Pan American and Olympic Summer Games, as well as Winter Games, the Organizing Committee has to take all the necessary measures to assure dental services to all competitors. In all Olympic villages, as part of the medical services, a dental clinic is set up to treat any dental emergency that may arise during the Games. Almost every participating country in the Games has its own medical team and some may include a dentist. The major responsibilities of the team dentist as a member of the national sports delegation include: (i) education of the sports delegation about different oral and dental diseases and the illustration of possible problems that athletes or other personnel may encounter during the Games, (ii) adequate training and management of orofacial trauma during the competition, (iii) knowledge about the rules and regulations of the specific sport that the dentist is working, (iv) understanding of the anti-doping control regulations and procedures, (v) necessary skills to fabricate a custom-made and properly fitted mouth guard to all participants in contact or collision sports of the delegation. This study illustrates the dental services and occurrence of orofacial injury at the Central American and Caribbean Sports Games of the Puerto Rican Delegation for the past 20 years. A total of 2107 participants made up the six different delegations at these Games. Of these 279 or 13.2% were seen for different dental conditions. The incidence of acute or emergency orofacial conditions was 18 cases or 6% of the total participants. The most frequent injury was lip contusion with four cases and the sport that experienced more injuries was basketball with three cases.

  17. Lead isotope composition of Central American volcanoes: Influence of the Galapagos plume

    NASA Astrophysics Data System (ADS)

    Feigenson, Mark D.; Carr, Michael J.; Maharaj, Susan V.; Juliano, Scott; Bolge, Louise L.

    2004-06-01

    Lead isotopic analyses of lavas from Central America, both along and behind the volcanic arc, help to clarify source components in the mantle wedge. Analysis of previous Pb isotopic data had implied that little or no marine sediment lead was added to the Central American source region, as all samples fell within the MORB field, in contrast to other information (e.g., Ba/La, 10Be, 87Sr/86Sr) that indicated a high subduction component. The data presented here include several analyses of local marine sediment, showing it to be exceptionally unradiogenic in Pb and thus permitting high sediment contributions to the mantle source region without significant changes in Pb isotopes. Combined Pb-Nd and Pb-Sr isotopic diagrams clearly illustrate the influence of crustal contamination for samples from Guatemala and Honduras, and of subducted sediment for all lavas of the volcanic front. Samples collected behind the volcanic front are derived from mixing between enriched and depleted mantle sources, and in central Costa Rica (extending to the back arc) overlap Pb, Sr and Nd isotope values for both Cocos Island and some components of the Galapagos hot spot. The restricted geographical occurrence of the enriched mantle signature in Central America, coupled with the persistence of the signal well into the back arc region, imply that these lavas are sampling Galapagos plume-influenced mantle. The presence of this plume component beneath southern Central America and extending to the northeast beneath the Caribbean confirms a Galapagos hot spot origin for this part of Caribbean Plate.

  18. "Central American Children Speak: Our Lives and Our Dreams." Study Guide to the Video with Stories and Background Information for Educators.

    ERIC Educational Resources Information Center

    Sommers, Meredith

    The videotape "Central American Children Speak: Our Lives and Dreams" begins and ends in a U.S. classroom where students are studying Central America. The video, which was designed to help children gain a basic understanding of one another, follows seven Central American children through a typical day of school, work, and play. Their…

  19. An energy atlas of five Central American countries. Un atlas energetico de cinco paises Centroamericanos

    SciTech Connect

    Trocki, L.; Newman, C.K.; Gurule, F.; Aragon, P.C.; Peck, C.

    1988-08-01

    In a series of maps and figures, this atlas summarizes what is known about the energy resources and how these resources and oil imports supply the energy needs of five Central American countries: Guatemala, El Salvador, Honduras, Costa Rica, and Panama. The main exploited energy resources are firewood, hydroelectric energy, bagasse from sugar cane residues, and geothermal energy. Limited oil exploration in the region has uncovered modest oil resources only in Guatemala. Peat and small coal deposits are also known to exist but are not presently being exploited. After the description of energy resources, this atlas describes energy supply and demand patterns in each country. It concludes with a description of socioeconomic data that strongly affect energy demand. 4 refs.

  20. Deaths of Mexican and Central American children along the US border: the Pima County Arizona experience.

    PubMed

    Bowen, Kathryn A; Marshall, William N

    2008-02-01

    Using data obtained through the Arizona Child Fatality Review Program, we reviewed deaths of all children (birth-17 years) who were Mexican or Central American residents and who died in Pima County, Arizona during the years 1995-2004. They accounted for 5% of all pediatric deaths in the county. Causes of death were motor vehicle collision (32%), environmental exposure (17%), prematurity (11%), other trauma (11%) and other medical conditions (28%). Fifty-three percent of these children were in the US seeking medical care; 36% were undocumented migrants. Significant trends over the 10 years were toward fewer children seeking medical care and more children dying while border crossing. Border health and economic disparities affected overall child mortality in this US county, but current prevention efforts are unlikely to affect this population group.

  1. Legal status and educational transitions for mexican and central american immigrant youth.

    PubMed

    Greenman, Emily; Hall, Matthew

    2013-06-01

    This study uses the Survey of Income and Program Participation to infer the legal status of Mexican and Central American immigrant youth and to investigate its relationship with educational attainment. We assess differences by legal status in high school graduation and college enrollment, decompose differences in college enrollment into the probability of high school graduation and the probability of high school graduates' enrollment in college and estimate the contributions of personal and family background characteristics to such differences. Results show that undocumented students are less likely than documented students to both graduate from high school and enroll in college, and differences in college enrollment cannot be explained by family background characteristics. We conclude that legal status is a critical axis of stratification for Latinos.

  2. Public health surveillance during the XVII Central American and Caribbean Games--Puerto Rico, November 1993.

    PubMed

    1996-07-12

    To provide medical services at mass gatherings for scheduled special events (e.g., world fairs, music festivals, and athletic competitions such as the Olympics), organizers must have information to anticipate both routine and uncommon situations. In November 1993, approximately 9500 athletes and staff from 31 countries participated in the XVII Central American and Caribbean Games in San Juan, Puerto Rico. To monitor injury- and illness-related morbidity among participants, the schools of public health and medicine at the University of Puerto Rico and the Puerto Rico Olympic Committee established a public health surveillance system designed specifically for this event. This report summarizes selected results from the system, which underscore the usefulness of this approach in planning prevention, medical, and emergency services for similar events.

  3. HIV testing behaviors among undocumented Central American immigrant women in Houston, Texas.

    PubMed

    Montealegre, Jane R; Risser, Jan M; Selwyn, Beatrice J; Sabin, Keith; McCurdy, Sheryl A

    2012-02-01

    This paper describes HIV testing behaviors among undocumented Central American immigrant women living in Houston, Texas, USA. Respondent driven sampling was used to recruit participants for an HIV behavioral survey. HIV testing items included lifetime history of testing, date and location of the most recent test, and reason for testing. Multivariate logistic regression was used to assess the demographic, behavioral, and structural characteristics associated with testing. The lifetime prevalence of HIV testing was 67%. Half of those who tested did so within the past 2 years and almost 80% received their most recent test in a healthcare setting. The primary reason for testing was pregnancy. Lifetime testing was associated with being from Honduras, having over a sixth grade education, having a regular healthcare provider, and having knowledge of available healthcare resources. Our results suggest that expanding access to healthcare services may increase the prevalence of HIV testing in this population.

  4. Legal Status and Educational Transitions for Mexican and Central American Immigrant Youth

    PubMed Central

    Greenman, Emily; Hall, Matthew

    2013-01-01

    This study uses the Survey of Income and Program Participation to infer the legal status of Mexican and Central American immigrant youth and to investigate its relationship with educational attainment. We assess differences by legal status in high school graduation and college enrollment, decompose differences in college enrollment into the probability of high school graduation and the probability of high school graduates' enrollment in college and estimate the contributions of personal and family background characteristics to such differences. Results show that undocumented students are less likely than documented students to both graduate from high school and enroll in college, and differences in college enrollment cannot be explained by family background characteristics. We conclude that legal status is a critical axis of stratification for Latinos. PMID:24511162

  5. Source of lead in Central American and Caribbean mineralization, II. Lead isotope provinces

    NASA Astrophysics Data System (ADS)

    Cumming, George L.; Kesler, Stephen E.; Krstic, Dragan

    1981-12-01

    In an earlier study of Mesozoic and Cenozoic mineralization in Central America and the Caribbean region, we found that lead isotopic compositions of deposits in northern Central America, which is underlain by a pre-Mesozoic craton, ranged to higher 206Pb/ 204Pb and 207Pb/ 204Pb compositions than did deposits from elsewhere in the region, where the basement is Mesozoic oceanic material. Using 16 analyses for 12 new deposits, as well as new analyses for 11 of the samples studied previously, we have found that lead isotopic compositions correlate closely with crustal type but show little or no correlation with depth to the M-discontinuity. The deposits are divisible into three main groups including (in order of increasing 207Pb/ 204Pb and 208Pb/ 204Pb ratio): (1) deposits in southern Central America and all deposits in the Greater Antilles except Cuba; (2) all deposits in northern Central America; and (3) the Cuban deposits. Southern Central American and Caribbean lead is higher in 207Pb/ 204Pb and 208Pb/ 204Pb than most mid-ocean ridge basalts but could have been derived directly or indirectly from undepleted mantle. Northern Central America can be divided into the Maya block, which belongs to the Americas plate, and the Chortis block, which belongs to the Caribbean plate. Maya block deposits fall along a linear array whereas those of the Chortis block (except the Monte Cristo deposit) form a cluster. These results suggest that the Maya block is underlain by crust or mantle with a large range of U/Pb and Th/U ratios, whereas the Chortis block basement is more homogeneous. Two-stage model calculations indicate an age of about 2280±310 m.y. for the Maya block basement, although no such rocks are known in the region. Comparison of the Chortis block data to our recently published lead isotopic analyses of Mexican deposits shows considerable similarities suggesting that the Chortis block could have been derived from Mexico.

  6. The View from the Isthmus: Central American paleoclimates on millennial to multidecadal time scales

    NASA Astrophysics Data System (ADS)

    Lachniet, M.; Asmerom, Y.; Burns, S.; Polyak, V.; Roy, A.; Azouz, A.; Burt, L.

    2006-12-01

    Paleoclimatic changes in tropical Central and South America are linked by changes in the strength and latitudinal position of the Intertropical Convergence Zone (ITCZ), which in turn is forced by ocean-atmosphere processes such as the glacial temperature depression, the El Nino/Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO), and the Atlantic Multidecadal Oscillation (AMO). This review summarizes both discreet and continuous archives of Central American paleoclimate, and offers a comparison to other regions of South America and the higher latitudes. During the last glacial period, glaciers in the Guatemalan and Costa Rican highlands have expanded to leave clear geomorphic evidence of past glacier extent. Reconstruction of low equilibrium line altitudes (ELAs, 3500-3600 m a.s.l.) during the last local glacial maximum indicate montane (3500 m) temperature depression of 6-8°C relative to modern. The discontinuous glacial record is complemented by U-series dated speleothem oxygen isotope proxy records of past rainfall, calibrated with modern spatio-temporal isotope hydrology. Results indicate Dansgaard/Oeschger-type rainfall variability in Costa Rica over Marine Isotope Stage III. At finer time scales, speleothems indicate substantial centennial- to multi-decadal scale isotope variability over the Holocene that implicate low frequency variations in ENSO, and perhaps the AMO and PDO. Of note, the Holocene rainfall variability is equal in magnitude to the D/O-type rainfall oscillations during MIS 3, suggesting that thermohaline circulation and its associated feedback of cross-isthmian freshwater moisture transport are prominent controls on isthmian rainfall variability. Further, no trend to decreasing rainfall over the Holocene is noted, suggesting a minor role for precessional-solar insolation on isthmian rainfall. Although many questions remained unanswered, continued research into Mesoamerican paleoclimates will provide valuable information for

  7. Living conditions and emotional profiles of Cambodian, Central American, and Québécois youth.

    PubMed

    Rousseau, C; Drapeau, A; Platt, R

    2000-12-01

    To compare Cambodian and Central American adolescent refugees to Quebec with their Quebec-born peers in regard to emotional and behavioural problems, feelings of competence, and risk-behaviour profiles, and to examine relations between emotional variables and living conditions in the 3 groups. The sample consisted of 76 Cambodian, 82 Central American and 67 Québécois youth living in the Montreal area. The teenagers' internalization and externalization symptoms were assessed using the Child Behaviour Checklist (CBCL) and the Youth Self-Report (YSR); the YSR also provided a measure of their feelings of competence. Risk behaviour was reported by the teenagers. The socioeconomic status of the teenagers' households was taken into account in multiple regression analyses conducted for each group. The level of emotional and behavioural problems reported by teenagers was lowest in Central Americans and highest in Québécois; the latter group also reported more risk behaviours than did either refugee group. The socioeconomic status of the Cambodian and Central American refugee households was lower than that of the Québécois. Living conditions were not a major determinant of emotional distress in young Cambodians, but low annual income was associated with internalizing symptoms among Central American youth. The most powerful predictor of externalizing symptoms among the Québécois youth was having a single-parent household. This study underscores the contrast between the living conditions of young Cambodian and Central American refugees to Quebec and those of Quebec-born youth. These refugees' precarious socioeconomic status is not accompanied by an increase in adolescents' emotional and behavioural problems.

  8. Assessment of tsunami hazards for the Central American Pacific coast from southern Mexico to northern Peru

    NASA Astrophysics Data System (ADS)

    Brizuela, B.; Armigliato, A.; Tinti, S.

    2014-07-01

    Central America (CA), from Guatemala to Panama, has been struck by at least 52 tsunamis between 1539 and 2013, and in the extended region from Mexico to northern Peru (denoted as ECA, Extended Central America in this paper) the number of recorded tsunamis in the same time span is more than 100, most of which were triggered by earthquakes located in the Middle American Trench that runs parallel to the Pacific coast. The most severe event in the catalogue is the tsunami that occurred on 2 September 1992 off Nicaragua, with run-up measured in the range of 5-10 m in several places along the Nicaraguan coast. The aim of this paper is to assess the tsunami hazard on the Pacific coast of this extended region, and to this purpose a hybrid probabilistic-deterministic analysis is performed, that is adequate for tsunamis generated by earthquakes. More specifically, the probabilistic approach is used to compute the Gutenberg-Richter coefficients of the main seismic tsunamigenic zones of the area and to estimate the annual rate of occurrence of tsunamigenic earthquakes and their corresponding return period. The output of the probabilistic part of the method is taken as input by the deterministic part, which is applied to calculate the tsunami run-up distribution along the coast.

  9. Diet, dietary selectivity and density of South American Grey Fox, Lycalopex griseus, in Central Chile.

    PubMed

    Muñoz-Pedreros, Andrés; Yáñez, José; Norambuena, Heraldo V; Zúñiga, Alfredo

    2017-03-06

    The South American Grey Fox (Lycalopex griseus) is a canid widely distributed in southern South America, however some aspects of its biology are still poorly known. We studied the diet and density of L. griseus in the Lago Peñuelas Biosphere Reserve, in Central Chile. The trophic niche breadth was B = 6.16 (Bsta = 0.47) and prey diversity was H ' = 2.46 (Hmax' = 3.17, J' = 0.78). The highest proportions of prey consumed in the diet were Oryctolagus cuniculus (52.21%) and other mammals (32.78%). We compared these results with a latitudinal gradient of diet results for this species in Chile. L. griseus eats mostly mammals (> 90% of total prey), consuming the rodent Phyllotis darwini and reptiles in the Northern zone; O. cuniculus, Octodon degus and Abrocoma bennetti in the Central zone; Abrothrix spp. and lagomorphs in the Southern zone; and Lepus capensis and Ovis aries in the Austral zone. The estimated density of L. griseus in Lago Peñuelas NR was 1.3 foxes /km(2) . This article is protected by copyright. All rights reserved.

  10. Phylogeographic Diversity of the Lower Central American Cichlid Andinoacara coeruleopunctatus (Cichlidae)

    PubMed Central

    McCafferty, S. Shawn; Martin, Andrew; Bermingham, Eldredge

    2012-01-01

    It is well appreciated that historical and ecological processes are important determinates of freshwater biogeographic assemblages. Phylogeography can potentially lend important insights into the relative contribution of historical processes in biogeography. However, the extent that phylogeography reflects historical patterns of drainage connection may depend in large part on the dispersal capability of the species. Here, we test the hypothesis that due to their relatively greater dispersal capabilities, the neotropical cichlid species Andinoacara coeruleopunctatus will display a phylogeographic pattern that differs from previously described biogeographic assemblages in this important region. Based on an analysis of 318 individuals using mtDNA ATPase 6/8 sequence and restriction fragment length polymorphism data, we found eight distinct clades that are closely associated with biogeographic patterns. The branching patterns among the clades and a Bayesian clock analysis suggest a relatively rapid colonization and diversification among drainages in the emergent Isthmus of Panama followed by the coalescing of some drainages due to historical connections. We also present evidence for extensive cross-cordillera sharing of clades in central Panama and the Canal region. Our results suggest that contemporary phylogeographic patterns and diversification in Lower Central American fishes reflect an interaction of historical drainage connections, dispersal, and demographic processes. PMID:23008800

  11. The early origin of melanocortin receptors, agouti-related peptide, agouti signalling peptide, and melanocortin receptor-accessory proteins, with emphasis on pufferfishes, elephant shark, lampreys, and amphioxus.

    PubMed

    Västermark, Ake; Schiöth, Helgi B

    2011-06-11

    There are conflicting theories about the evolution of melanocortin MC receptors while only few studies have addressed the evolution of agouti-related peptide (AgRP) and agouti signalling peptide (ASIP), which are antagonists at the melanocortin receptors (MCRs), or the melanocortin MC(2) receptor accessory proteins (MRAP1 and MRAP2). Previously we have cloned melanocortin MC receptors (MC(a) and MC(b)) genes in river lamprey and here we identify orthologues to these melanocortin MC receptor sequences in the sea lamprey. We investigate the putative presence of the melanocortin MC receptor genes in lancelet (amphioxus; Branchiostoma floridae) but we find it unlikely that such gene exists, due to a sharp drop in sequence similarity beyond sequence clusters of known receptors. We show the presence of AgRP and ASIP in elephant shark, a cartilaginous fish belonging to the subclass of Elasmobranchii. However, we do not find any of these genes in lamprey or lancelet after detailed analysis of both targeted and whole proteome regular expression scans. We found MRAP2, but not MRAP1, to be present in elephant shark and sea lamprey while Fugu (T. rubripes) has both genes. This study shows that the most ancient presence of these melanocortin-related sequences is found in elephant shark and lampreys considering the current available sequence data.

  12. Characterization of the dog agouti gene and a nonagouti mutation in german shepherd dogs

    SciTech Connect

    Kerns, Julie A.; Newton, J.; Berryere, Tom G.; Rubin, Edward M.; Cheng, Jan-Fang; Schmutz, Sheila M.; Barsh, Gregory S.

    2004-07-08

    The interaction between two genes, Agouti and Melanocortin-1 receptor (Mc1r), produces diverse pigment patterns in mammals by regulating the type, amount, and distribution pattern of the two pigment types found in mammalian hair: eumelanin (brown/black) and pheomelanin (yellow/red). In domestic dogs (Canis familiaris), there is a tremendous variation in coat color patterns between and within breeds; however, previous studies suggest that the molecular genetics of pigment-type switching in dogs may differ from that of other mammals. Here we report the identification and characterization of the Agouti gene from domestic dogs, predicted to encode a 131-amino-acid secreted protein 98 percent identical to the fox homolog, and which maps to chromosome CFA24 in a region of conserved linkage. Comparative analysis of the Doberman Pinscher Agouti cDNA, the fox cDNA, and 180 kb of Doberman Pinscher genomic DNA suggests that, as with laboratory mice, different pigment-type-switching patterns in the canine family are controlled by alternative usage of different promoters and untranslated first exons. A small survey of Labrador Retrievers, Greyhounds, Australian Shepherds, and German Shepherd Dogs did not uncover any polymorphisms, but we identified a single nucleotide variant in black German Shepherd Dogs predicted to cause an Arg-to-Cys substitution at codon 96, which is likely to account for recessive inheritance of a uniform black coat.

  13. Interactions between straw size and thawing rates on the cryopreservation of agouti (Dasyprocta aguti) epididymal sperm.

    PubMed

    Silva, M A; Peixoto, G C X; Sousa, P C; Bezerra, F S B; Bezerra, A C D S; Silva, A R

    2012-02-01

    This study verifies the interactions between straw size and thawing rates and their impact on the epididymal sperm from this species. Caudae epididymidum from 10 agoutis were subjected to retrograde washing using a coconut water extender (ACP-109c(®) ). Epididymal sperm were evaluated and extended in ACP-109c(®) plus egg yolk (20%) and glycerol (6%). The samples were packaged in 0.25- or 0.50-ml straws, frozen in liquid nitrogen and thawed at 37°C/1 min or 70°C/8 s, followed by a re-evaluation. The use of 0.25-ml straws thawed at 37°C/1 min provided a value of 26.6% for sperm motility. No interactions between straw size and thawing rates were verified on agouti sperm (p > 0.05), but when 0.5-ml straws were thawed at 70°C/8 s, sperm vigour decreased significantly (p < 0.05). It is recommended that the agouti epididymal sperm cryopreserved in ACP-109c(®) extender should be packaged in 0.25- or 0.50-ml straws and thawed at 37°C/60 s.

  14. Characterization of the dog Agouti gene and a nonagoutimutation in German Shepherd Dogs.

    PubMed

    Kerns, Julie A; Newton, J; Berryere, Tom G; Rubin, Edward M; Cheng, Jan-Fang; Schmutz, Sheila M; Barsh, Gregory S

    2004-10-01

    The interaction between two genes, Agouti and Melanocortin-1 receptor ( Mc1r), produces diverse pigment patterns in mammals by regulating the type, amount, and distribution pattern of the two pigment types found in mammalian hair: eumelanin (brown/black) and pheomelanin (yellow/red). In domestic dogs ( Canis familiaris), there is a tremendous variation in coat color patterns between and within breeds; however, previous studies suggest that the molecular genetics of pigment-type switching in dogs may differ from that of other mammals. Here we report the identification and characterization of the Agouti gene from domestic dogs, predicted to encode a 131-amino-acid secreted protein 98% identical to the fox homolog, and which maps to chromosome CFA24 in a region of conserved linkage. Comparative analysis of the Doberman Pinscher Agouti cDNA, the fox cDNA, and 180 kb of Doberman Pinscher genomic DNA suggests that, as with laboratory mice, different pigment-type-switching patterns in the canine family are controlled by alternative usage of different promoters and untranslated first exons. A small survey of Labrador Retrievers, Greyhounds, Australian Shepherds, and German Shepherd Dogs did not uncover any polymorphisms, but we identified a single nucleotide variant in black German Shepherd Dogs predicted to cause an Arg-to-Cys substitution at codon 96, which is likely to account for recessive inheritance of a uniform black coat.

  15. Plasma epinephrine predicts fasting glucose in centrally obese African-American women.

    PubMed

    Surwit, Richard S; Williams, Redford B; Lane, James D; Feinglos, Mark N; Kuhn, Cynthia M; Georgiades, Anastasia

    2010-09-01

    The high prevalence of diabetes in African-American (AA) women has been widely assumed to be related to the greater prevalence of obesity in this group. Catecholamine release acting on central adipose tissue has been proposed to be a contributing factor. The aim of this article was to examine the interaction of plasma catecholamines and central adiposity on fasting and nonfasting glucose levels in two separate samples. In both studies, the women were healthy, nondiabetic of similar age. In addition, both studies assessed plasma epinephrine (EPI) and norepinephrine (NOREPI) levels collected at three time points. In study 1, catecholamines were measured during a standardized laboratory mental stress task and in study 2, they were measured during the initial phase (10 min) of an intravenous glucose tolerance test (IVGTT). Results from both studies revealed significant effects of EPI on fasting glucose in the obese women. In study 1, mean EPI levels were significantly related to fasting glucose in AA women with high trunk fat (beta = 0.60, P < 0.001). Because high BMI was associated with high trunk fat in women, we used BMI >30 as a proxy for high trunk fat (>32%) in study 2. In study 2, EPI response to the glucose bolus was a strong predictor of fasting glucose in AA women with BMI >30 (beta = 0.75, P < 0.003). We conclude that the effect of central adiposity on fasting glucose may be moderated by plasma EPI. This suggests that adrenal medullary activity could play a role in the pathophysiology of type 2 diabetes.

  16. The Pacific-Atlantic Dipole: A Climate Index with Effects on Trade Wind Strength and Central American Precipitation

    NASA Astrophysics Data System (ADS)

    Gervais, M.; Moore, K.; Cowling, S.

    2009-05-01

    The interaction of moist easterly trade winds and high Central American topography creates tropical rainforests in the mountains of Central America. Understanding changes in precipitation in this region is important because these rain forests host a wealth of biodiversity and are sensitive to changes in precipitation. This study focuses on causes of interannual variability in Central American precipitation. Specifically, we find that the relative phases of the Atlantic Nino and Pacific El Nino Southern Oscillation are related to the strength of the trade winds and precipitation over Central America. These relative phases are quantified through the creation of the Pacific Atlantic Dipole index, which is the difference between the Atlantic Nino and the El Nino Southern Oscillation indices. An index of moisture transport over Central America is also created. We find that the Pacific- Atlantic dipole is positively correlated to both the moisture transport index and to a new Central American precipitation station data set, comprised of 43 stations and spanning the period 1961-2000. Composites of years of high and low Pacific-Atlantic dipole index reveal the spatial pattern associated with its variability. These showed that when the PAD is low (high), there is a strengthening (weakening) of the subtropical high and a decrease (increase) in pressure over the eastern equatorial Pacific. This causes an increase (decrease) in the trade wind strength and subsequently a decrease (increase) in Central American precipitation. We conclude that the PAD index represents a dipole in sea surface temperature and sea level pressure between the Atlantic and Pacific Oceans. In the future, this could be used to predict interannual changes in trade wind strength and precipitation in Central America. With current changes in climate, a further understanding of this relationship may be important for the sensitive ecology in the region.

  17. Divergent Regulation of Energy Expenditure and Hepatic Glucose Production by Insulin Receptor in Agouti-Related Protein and POMC Neurons

    PubMed Central

    Lin, Hua V.; Plum, Leona; Ono, Hiraku; Gutiérrez-Juárez, Roger; Shanabrough, Marya; Borok, Erzsebet; Horvath, Tamas L.; Rossetti, Luciano; Accili, Domenico

    2010-01-01

    OBJECTIVE The sites of insulin action in the central nervous system that regulate glucose metabolism and energy expenditure are incompletely characterized. We have shown that mice with hypothalamic deficiency (L1) of insulin receptors (InsRs) fail to regulate hepatic glucose production (HGP) in response to insulin. RESEARCH DESIGN AND METHODS To distinguish neurons that mediate insulin's effects on HGP from those that regulate energy homeostasis, we used targeted knock-ins to express InsRs in agouti-related protein (AgRP) or proopiomelanocortin (POMC) neurons of L1 mice. RESULTS Restoration of insulin action in AgRP neurons normalized insulin suppression of HGP. Surprisingly, POMC-specific InsR knock-in increased energy expenditure and locomotor activity, exacerbated insulin resistance and increased HGP, associated with decreased expression of the ATP-sensitive K+ channel (KATP channel) sulfonylurea receptor 1 subunit, and decreased inhibitory synaptic contacts on POMC neurons. CONCLUSIONS The contrasting phenotypes of InsR knock-ins in POMC and AgRP neurons suggest a branched-pathway model of hypothalamic insulin signaling in which InsR signaling in AgRP neurons decreases HGP, whereas InsR activation in POMC neurons promotes HGP and activates the melanocortinergic energy expenditure program. PMID:19933998

  18. Central American ants of the genus Megalomyrmex Forel (Hymenoptera: Formicidae): six new species and keys to workers and males.

    PubMed

    Boudinot, Brendon E; Sumnicht, Theodore P; Adams, Rachelle M M

    2013-11-04

    Megalomyrmex Forel is a distinctive lineage of Neotropical ants, some of which are specialized parasites or predators of the fungus-growing ants Attini. Here we review and key the Central American fauna. Six new species are described from both female castes: M. brandaoi sp. n., M. fungiraptor sp. n., M. longinoi sp. n., M. milenae sp. n., M. megadrifti sp. n. and M. osadrifti sp. n. A worker-based key to all Central American species is presented, and all species are illustrated. Megalomyrmex drifti Kempf is redescribed and the first descriptions of queens for M. miri Brandão and M. foreli Emery are provided. New biological information, several new geographic records, and a discussion of the species-group schema of Brandão (1990) are presented. The male sex of Megalomyrmex is diagnosed at the genus-level and keyed to species for the Central American fauna, where known. The male of each species treated in the key is diagnosed, described, or redescribed. Males are known for fourteen out of twenty total Central American Megalomyrmex species. A distinct but unassociated male is described and keyed (M. male 01). The males of M. miri Brandão and M. wettereri Brandão are described for the first time, and the distinctness of these two species is confirmed. One potential synapomorphy of Megalomyrmex present in males and workers is the presence of a carina which posteriorly delimits the basalmost region of the petiolar dorsum. 

  19. Participation in a Technological World: The Meaning of Educational Technology in the Lives of Young Adult Central American Immigrants.

    ERIC Educational Resources Information Center

    Pruitt-Mentle, Davina S.

    Many communities throughout the United States are experiencing a large influx of Central American immigrants. Langley Park, Maryland is typical of the pockets that are formed by the new arrivals. Community members of Latino background now account for 60% of the population, while in 1990 they were only 40% (US Census, 2000). As the immigrants move…

  20. The Effects of a Social-Emotional Intervention on Caregivers and Children with Disabilities in Two Central American Institutions

    ERIC Educational Resources Information Center

    Groark, Christina J.; McCall, Robert B.; McCarthy, Stephanie K.; Eichner, Joan C.; Warner, Hilary A.; Salaway, Jennifer; Palmer, Kalani; Lopez, Meghan E.

    2013-01-01

    This field study describes changes in caregiving and young children's physical and behavioral/cognitive development as a consequence of a pilot intervention using typical staff in 2 Central American orphanages for children with severe and multiple disabilities. The intervention trained staff in sensitive, responsive, child-directed,…

  1. The Work Kids Do: Mexican and Central American Immigrant Children's Contributions to Households and Schools in California.

    ERIC Educational Resources Information Center

    Orellana, Marjorie Faulstich

    2001-01-01

    Research on Mexican and Central American immigrant children illuminates their everyday work as helpers in the home, community, and school. Their participation is shaped by gender dynamics. Their work can be viewed in multiple ways as volunteerism, learning opportunities, and cultural and linguistic brokering. (Contains 57 references.) (SK)

  2. Volatile (H2O, CO2, Cl, S) budget of the Central American subduction zone

    NASA Astrophysics Data System (ADS)

    Freundt, A.; Grevemeyer, I.; Rabbel, W.; Hansteen, T. H.; Hensen, C.; Wehrmann, H.; Kutterolf, S.; Halama, R.; Frische, M.

    2014-02-01

    After more than a decade of multidisciplinary studies of the Central American subduction zone mainly in the framework of two large research programmes, the US MARGINS program and the German Collaborative Research Center SFB 574, we here review and interpret the data pertinent to quantify the cycling of mineral-bound volatiles (H2O, CO2, Cl, S) through this subduction system. For input-flux calculations, we divide the Middle America Trench into four segments differing in convergence rate and slab lithological profiles, use the latest evidence for mantle serpentinization of the Cocos slab approaching the trench, and for the first time explicitly include subduction erosion of forearc basement. Resulting input fluxes are 40-62 (53) Tg/Ma/m H2O, 7.8-11.4 (9.3) Tg/Ma/m CO2, 1.3-1.9 (1.6) Tg/Ma/m Cl, and 1.3-2.1 (1.6) Tg/Ma/m S (bracketed are mean values for entire trench length). Output by cold seeps on the forearc amounts to 0.625-1.25 Tg/Ma/m H2O partly derived from the slab sediments as determined by geochemical analyses of fluids and carbonates. The major volatile output occurs at the Central American volcanic arc that is divided into ten arc segments by dextral strike-slip tectonics. Based on volcanic edifice and widespread tephra volumes as well as calculated parental magma masses needed to form observed evolved compositions, we determine long-term (105 years) average magma and K2O fluxes for each of the ten segments as 32-242 (106) Tg/Ma/m magma and 0.28-2.91 (1.38) Tg/Ma/m K2O (bracketed are mean values for entire Central American volcanic arc length). Volatile/K2O concentration ratios derived from melt inclusion analyses and petrologic modelling then allow to calculate volatile fluxes as 1.02-14.3 (6.2) Tg/Ma/m H2O, 0.02-0.45 (0.17) Tg/Ma/m CO2, and 0.07-0.34 (0.22) Tg/Ma/m Cl. The same approach yields long-term sulfur fluxes of 0.12-1.08 (0.54) Tg/Ma/m while present-day open-vent SO2-flux monitoring yields 0.06-2.37 (0.83) Tg/Ma/m S. Input-output comparisons

  3. Biotechnology for developing countries. The case of the Central American isthmus.

    PubMed

    León, P E

    1993-12-21

    Recent developments in the fields of chemistry, molecular biology, computer science, and communications promise to transform the way that many things will be done in the near future in diverse fields of scientific R&D. Fortunately for less developed countries (LDCs) some of the technologies involved are user friendly and safe, avoiding the need for radioactive precursors, large machines, or expensive reagents. For instance, tissue culture, polymerase chain reaction (PCR), dideoxi-sequencing, and recombinant DNA techniques have already invaded clinical laboratories, agricultural field stations, and natural history museums, even in some developing nations. Somatic cell culture for plant biotechnology and immunologic techniques for diagnosis have had wide applications for over a decade in all countries in the Central American Isthmus. More recently, recombinant DNA techniques, including PCR, have been introduced for diagnostic purposes and research at the two largest universities in Costa Rica and at other public institutions and are also used in Guatemala and Panama. Honduras and Nicaragua are only now acquiring these technologies for diagnostic purposes. Biotechnological applications in industry seem to be lagging behind, and presently no good links exist between research laboratories and industry for advanced applications. The application of biotechnologies in environmental problems is slowly underway, with molecular studies of natural wildlife populations and primary forest trees. A major effort is needed to create safe and effective ways of dealing with environmental degradation, wastes, and byproducts of tropical agriculture and industry. The creation of the National Biodiversity Institute (INBio) in Costa Rica to elaborate an inventory of flora and fauna and to prospect for useful substances provides a unique opportunity for biotechnological applications. In addition, government policies to promote biotechnological development are supported by CONICIT (National

  4. Coordinated Dispersal and Pre-Isthmian Assembly of the Central American Ichthyofauna.

    PubMed

    Tagliacollo, Victor A; Duke-Sylvester, Scott M; Matamoros, Wilfredo A; Chakrabarty, Prosanta; Albert, James S

    2017-03-01

    We document patterns of coordinated dispersal over evolutionary time frames in heroine cichlids and poeciliine live-bearers, the two most species-rich clades of freshwater fishes in the Caribbean basin. Observed dispersal rate (DO) values were estimated from time-calibrated molecular phylogenies in Lagrange+, a modified version of the ML-based parametric biogeographic program Lagrange. DO is measured in units of "wallaces" (wa) as the number of biogeographic range-expansion events per million years. DO estimates were generated on a dynamic paleogeographic landscape of five areas over three time intervals from Upper Cretaceous to Recent. Expected dispersal rate (DE) values were generated from alternative paleogeographic models, with dispersal rates proportional to target area and source-river discharge volume, and inversely proportional to paleogeographic distance. Correlations between DO and DE were used to assess the relative contributions of these three biogeographic parameters. DO estimates imply a persistent dispersal corridor across the Eastern (Antillean) margin of the Caribbean plate, under the influence of prevailing and perennial riverine discharge vectors such as the Proto-Orinoco-Amazon river. Ancestral area estimation places the earliest colonizations of the Greater Antilles and Central America during the Paleocene-Eocene (ca. 58-45 Ma), potentially during the existence of an incomplete Paleogene Arc (∼59 Ma) or Lesser Antilles Arc (∼45 Ma), but predating the GAARlandia land bridge (∼34-33 Ma). Paleogeographic distance is the single best predictor of DO. The Western (Central American) plate margin did not serve as a dispersal corridor until the Late Neogene (12-0 Ma), and contributed relatively little to the formation of modern distributions. © The Author(s) 2015. Published by Oxford University Press, on behalf of the Society of Systematic Biologists.

  5. On-and offshore tephrostratigraphy and -chronology of the southern Central American Volcanic Arc (CAVA)

    NASA Astrophysics Data System (ADS)

    Schindlbeck, J. C.; Kutterolf, S.; Hemming, S. R.; Wang, K. L.

    2015-12-01

    Including the recently drilled CRISP sites (IODP Exp. 334&344) the deep sea drilling programs have produced 69 drill holes at 29 Sites during 9 Legs at the Central American convergent margin, where the Cocos plate subducts beneath the Caribbean plate. The CAVA produced numerous plinian eruptions in the past. Although abundant in the marine sediments, information and data regarding large late Cenozoic explosive eruptions from Costa Rica, Nicaragua, Honduras, El Salvador, and Guatemala remain very sparse and discontinuous on land. We have established a tephrostratigraphy from recent through Miocene times from the unique archive of ODP/IODP sites offshore Central America in which we identify tephra source regions by geochemical fingerprinting using major and trace element glass shard compositions. Here we present first order correlations of ­~500 tephra layers between multiple holes at a single site as well as between multiple sites. We identified ashes supporting Costa Rican (~130), Nicaraguan (17) and Guatemalan (27) sources as well as ~150 tephra layers from the Galápagos hotspot. Within our marine record we also identified well-known marker beds such as the Los Chocoyos tephra from Atitlán Caldera in Guatemala and the Tiribi Tuff from Costa Rica but also correlations to 15 distinct deposits from known Costa Rican and Nicaraguan eruptions within the last 4.1 Ma. These correlations, together with new radiometric age dates, provide the base for an improved tephrochronostratigraphy in this region. Finally, the new marine record of explosive volcanism offshore southern CAVA provides insights into the eruptive history of long-living volcanic complexes (e.g., Barva, Costa Rica) and into the distribution and frequency of large explosive eruptions from the Galápagos hotspot. The integrated approach of Ar/Ar age dating, correlations with on land deposits from CAVA, biostratigraphic ages and sediment accumulation rates improved the age models for the drilling sites.

  6. Combating Gangs: Federal Agencies Have Implemented a Central American Gang Strategy, but Could Strengthen Oversight and Measurement of Efforts. Report to Congressional Requesters. GAO-10-395

    ERIC Educational Resources Information Center

    Larence, Eileen R.

    2010-01-01

    Thousands of gang members in the United States belong to gangs such as MS-13 and 18th Street that are also active in Central American countries. Federal entities with responsibilities for addressing Central American gangs include the National Security Council (NSC); the Departments of Homeland Security (DHS), Justice (DOJ), and State; and the U.S.…

  7. Healthcare coverage and use among undocumented Central American immigrant women in Houston, Texas.

    PubMed

    Montealegre, Jane R; Selwyn, Beatrice J

    2014-04-01

    We investigated the prevalence and correlates of having current healthcare coverage and of having a usual formal source of care among undocumented Central American immigrant women. Participants were recruited using respondent driven sampling. Thirty-five percent of participants had healthcare coverage and 43% had a usual formal source of care. Healthcare coverage was primarily through the local indigent healthcare program and most of those with a usual formal source of care received care at a public healthcare clinic. Having healthcare coverage and having a usual formal source of care were both associated with older age; having a usual formal source of care was also marginally associated with increased time of residence in the US and increased income security. The primary barriers to healthcare use were not having money or insurance, not knowing where to go, and not having transportation. Healthcare interventions may benefit from targeting young and newly arrived immigrants and addressing the structural and belief barriers that impede undocumented immigrant women's use of healthcare services.

  8. Atlantic Deep-water Response to the Early Pliocene Shoaling of the Central American Seaway

    PubMed Central

    Bell, David B.; Jung, Simon J. A.; Kroon, Dick; Hodell, David A.; Lourens, Lucas J.; Raymo, Maureen E.

    2015-01-01

    The early Pliocene shoaling of the Central American Seaway (CAS), ~4.7–4.2 million years ago (mega annum-Ma), is thought to have strengthened Atlantic Meridional Overturning Circulation (AMOC). The associated increase in northward flux of heat and moisture may have significantly influenced the evolution of Pliocene climate. While some evidence for the predicted increase in North Atlantic Deep Water (NADW) formation exists in the Caribbean and Western Atlantic, similar evidence is missing in the wider Atlantic. Here, we present stable carbon (δ13C) and oxygen (δ18O) isotope records from the Southeast Atlantic-a key region for monitoring the southern extent of NADW. Using these data, together with other δ13C and δ18O records from the Atlantic, we assess the impact of the early Pliocene CAS shoaling phase on deep-water circulation. We find that NADW formation was vigorous prior to 4.7 Ma and showed limited subsequent change. Hence, the overall structure of the deep Atlantic was largely unaffected by the early Pliocene CAS shoaling, corroborating other evidence that indicates larger changes in NADW resulted from earlier and deeper shoaling phases. This finding implies that the early Pliocene shoaling of the CAS had no profound impact on the evolution of climate. PMID:26193070

  9. Late Cenozoic tephrostratigraphy offshore the southern Central American Volcanic Arc: 1. Tephra ages and provenance

    NASA Astrophysics Data System (ADS)

    Schindlbeck, J. C.; Kutterolf, S.; Freundt, A.; Alvarado, G. E.; Wang, K.-L.; Straub, S. M.; Hemming, S. R.; Frische, M.; Woodhead, J. D.

    2016-11-01

    We studied the tephra inventory of 18 deep-sea drill sites from six DSDP/ODP legs (Legs 84, 138, 170, 202, 205, and 206) and two IODP legs (Legs 334 and 344) offshore the southern Central American Volcanic Arc (CAVA). Eight drill sites are located on the incoming Cocos plate and 10 drill sites on the continental slope of the Caribbean plate. In total, we examined ˜840 ash-bearing horizons and identified ˜650 of these as primary ash beds of which 430 originated from the CAVA. Correlations of ash beds were established between marine cores and with terrestrial tephra deposits, using major and trace element glass compositions with respect to relative stratigraphic order. As a prerequisite for marine-terrestrial correlations, we present a new geochemical data set for significant Neogene and Quaternary Costa Rican tephras. Moreover, new Ar/Ar ages for marine tephras have been determined and marine ash beds are also dated using the pelagic sedimentation rates. The resulting correlations and provenance analyses build a tephrochronostratigraphic framework for Costa Rica and Nicaragua that covers the last <15 Myr. We define 39 correlations of marine ash beds to specific tephra formations in Costa Rica and Nicaragua; from the 4.15 Ma Lower Sandillal Ignimbrite to the 3.5 ka Rincón de la Vieja Tephra from Costa Rica, as well as another 32 widely distributed tephra layers for which their specific region of origin along Costa Rica and Nicaragua can be constrained.

  10. Venomic and antivenomic analyses of the Central American coral snake, Micrurus nigrocinctus (Elapidae).

    PubMed

    Fernández, Julián; Alape-Girón, Alberto; Angulo, Yamileth; Sanz, Libia; Gutiérrez, José María; Calvete, Juan J; Lomonte, Bruno

    2011-04-01

    The proteome of the venom of Micrurus nigrocinctus (Central American coral snake) was analyzed by a "venomics" approach. Nearly 50 venom peaks were resolved by RP-HPLC, revealing a complex protein composition. Comparative analyses of venoms from individual specimens revealed that such complexity is an intrinsic feature of this species, rather than the sum of variable individual patterns of simpler composition. Proteins related to eight distinct families were identified by MS/MS de novo peptide sequencing or N-terminal sequencing: phospholipase A(2) (PLA(2)), three-finger toxin (3FTx), l-amino acid oxidase, C-type lectin/lectin-like, metalloproteinase, serine proteinase, ohanin, and nucleotidase. PLA(2)s and 3FTxs are predominant, representing 48 and 38% of the venom proteins, respectively. Within 3FTxs, several isoforms of short-chain α-neurotoxins as well as muscarinic-like toxins and proteins with similarity to long-chain κ-2 bungarotoxin were identified. PLA(2)s are also highly diverse, and a toxicity screening showed that they mainly exert myotoxicity, although some are lethal and may contribute to the known presynaptic neurotoxicity of this venom. An antivenomic characterization of a therapeutic monospecific M. nigrocinctus equine antivenom revealed differences in immunorecognition of venom proteins that correlate with their molecular mass, with the weakest recognition observed toward 3FTxs.

  11. Wave reflection effects in the central circulation of American alligators (Alligator mississippiensis): what the heart sees.

    PubMed

    Syme, Douglas A; Gamperl, A Kurt; Braun, Marvin H; Jones, David R

    2006-10-01

    A large central compliance is thought to dominate the hemodynamics of all vertebrates except birds and mammals. Yet large crocodilians may adumbrate the avian and mammalian condition and set the stage for significant wave transmission (reflection) effects, with potentially detrimental impacts on cardiac performance. To investigate whether crocodilians exhibit wave reflection effects, pressures and flows were recorded from the right aorta, carotid artery, and femoral artery of six adult, anesthetized American alligators (Alligator mississippiensis) during control conditions and after experimentally induced vasodilation and constriction. Hallmarks of wave reflection phenomena were observed, including marked differences between the measured profiles for flow and pressure, peaking of the femoral pressure pulse, and a diastolic wave in the right aortic pressure profile. Pulse wave velocity and peripheral input impedance increased with progressive constriction, and thus changes in both the timing and magnitude of reflections accounted for the altered reflection effects. Resolution of pressure and flow waves into incident and reflected components showed substantial reflection effects within the right aorta, with reflection coefficients at the first harmonic approaching 0.3 when constricted. Material properties measured from isolated segments of blood vessels revealed a major reflection site at the periphery and, surprisingly, at the junction of the truncus and right aorta. Thus, while our results clearly show that significant wave reflection phenomena are not restricted to birds and mammals, they also suggest that rather than cope with potential negative impacts of reflections, the crocodilian heart simply avoids them because of a large impedance mismatch at the truncus.

  12. Intrabasin Variability of East Pacific Tropical Cyclones During ENSO Regulated by Central American Gap Winds.

    PubMed

    Fu, Dan; Chang, Ping; Patricola, Christina M

    2017-05-10

    Hurricane Patricia in 2015 was the strongest Pacific hurricane to make landfall in Mexico. Although Patricia fortuitously spared major cities, it reminded us of the threat tropical cyclones (TCs) pose in the eastern North Pacific (ENP) and the importance of improving our understanding and prediction of ENP TCs. Patricia's intensity and the active 2015 ENP hurricane season have been partially attributed to the strong El Niño in 2015, however there is still a lack of fundamental understanding of the relationship between El Niño-Southern Oscillation (ENSO) and ENP TCs. Here, we demonstrate that ENSO drives intrabasin variability of ENP TCs, with enhanced (reduced) TC frequency in the western portion of the ENP during El Niño (La Niña), but reduced (enhanced) TC frequency in the eastern nearshore area, where landfalling TCs preferentially form. This intrabasin difference is primarily driven by the Central American Gap Winds (CAGW), which intensify (weaken) during El Niño (La Niña), producing low-level anticyclonic (cyclonic) relative vorticity anomalies and thus an unfavorable (favorable) environment for TC genesis. These findings shed new light on the dynamics linking ENP TC activity to ENSO, and highlight the importance of improving CAGW representation in models to make skillful seasonal forecasts of ENP TCs.

  13. [Social determinants of exclusion from health services and medicines in three Central American countries].

    PubMed

    Acuña, Cecilia; Marina, Nelly; Mendoza, Adriana; Emmerick, Isabel Cristina Martins; Luiza, Vera Lucía; Azeredo, Thiago Botelho

    2014-02-01

    Examine the social determinants that affect population behavior with regard to the search for and acquisition of medicines, and their relationship to exclusion from health services based on aggregate data from three Central American countries: Guatemala, Honduras, and Nicaragua. A descriptive, observational cross-sectional study was conducted by administration of a household survey. The study sample was selected in accordance with the conglomerate method. Data was analyzed with the SPSS® V.17 program using descriptive statistics, bivariate, multivariate, and principal components analysis (PCA). Although the majority of the persons could access health care, health exclusion (odds ratio [OR] 4.10; 95% confidence interval [95% CI]) was the main determinant of lack of access to medicines. The characteristics of housing (OR 0.747, 95% CI), formal employment of head of the household (OR 0.707, 95% CI), and socioeconomic status of the household (OR 0.462, 95% CI) were also important determinants of lack of access to medicines. The phenomena of lack of access to health services and medicines are not independent from one another. It was corroborated that the health system, as an intermediate social determinant of health, is an important factor for improvement of access to medicines. Public policies that aim to achieve universal coverage should consider this relationship in order to be effective.

  14. Feasibility studies of a power interconnection system for Central American countries: SIEPAC project

    SciTech Connect

    Gomez, T.; Enamorado, J.C. . Inst. de Investigacion Tecnologica); Vela, A. )

    1994-06-01

    The electrical systems of the Central American countries are linked by 230 kV ac weak border interconnections forming two separated subsystems. The first one includes Guatemala and El Salvador, and the other one comprises the systems of Honduras, Nicaragua, Costa Rica, and Panama. As a consequence, unrestricted energy exchanges among all countries are not possible. This article describes the SIEPAC project which consists of a 1,678 km long 500 kV ac power transmission line that would link the six electrical systems of the region through seven power substations (one for each country and two in Panama), installed close to the highest demand national centers and six control centers of energy (one for each country) to allow coordinated operation of the interconnection.This project also considers a set of complementary assets (230 ac power transmission lines into some countries and the border transmission line between El Salvador and Honduras, and various other equipment). The power transmission line will greatly reinforce the actual border interconnections, which have a reduced capacity of exchange and technical problems associated with the stability of a weak longitudinal system. On the other hand, economic savings for the region would be achieved, coming from a higher coordination level in the operation and planning of their systems.

  15. Atlantic Deep-water Response to the Early Pliocene Shoaling of the Central American Seaway.

    PubMed

    Bell, David B; Jung, Simon J A; Kroon, Dick; Hodell, David A; Lourens, Lucas J; Raymo, Maureen E

    2015-07-20

    The early Pliocene shoaling of the Central American Seaway (CAS), ~4.7-4.2 million years ago (mega annum-Ma), is thought to have strengthened Atlantic Meridional Overturning Circulation (AMOC). The associated increase in northward flux of heat and moisture may have significantly influenced the evolution of Pliocene climate. While some evidence for the predicted increase in North Atlantic Deep Water (NADW) formation exists in the Caribbean and Western Atlantic, similar evidence is missing in the wider Atlantic. Here, we present stable carbon (δ(13)C) and oxygen (δ(18)O) isotope records from the Southeast Atlantic-a key region for monitoring the southern extent of NADW. Using these data, together with other δ(13)C and δ(18)O records from the Atlantic, we assess the impact of the early Pliocene CAS shoaling phase on deep-water circulation. We find that NADW formation was vigorous prior to 4.7 Ma and showed limited subsequent change. Hence, the overall structure of the deep Atlantic was largely unaffected by the early Pliocene CAS shoaling, corroborating other evidence that indicates larger changes in NADW resulted from earlier and deeper shoaling phases. This finding implies that the early Pliocene shoaling of the CAS had no profound impact on the evolution of climate.

  16. Spatial analysis of American Visceral Leishmaniasis in Mato Grosso do Sul State, Central Brazil.

    PubMed

    Correa Antonialli, Suely Aparecida; Torres, Thais Gisele; Paranhos Filho, Antonio Conceição; Tolezano, José Eduardo

    2007-05-01

    To map American Visceral Leishmaniasis (AVL) in Mato Grosso do Sul State (Central Brazil). The distribution of AVL was mapped, using the Geographic Information System. The disease was endemic to the Corumbá Region from 1913 to 1998. Spatial and temporal analysis indicated that the expansion route and dissemination through the State of the disease has been from west to east, coinciding with three different human interventions; two of them, a federal highway and a rail-road, were constructed in the early twentieth century, from east to west, from Bauru city, in São Paulo State, to Corumbá city, in Mato Grosso do Sul State. The third anthropogenic intervention was the construction of a gas pipeline that started in 1998, and attracted thousands of workers. This construction route has the same direction, west to east, and timescale as the observed expansion and dissemination of AVL. The results relate the expansion of the disease to intense human traffic along the route of spread.

  17. Mitochondrial DNA diversity and origins of South and Central American goats.

    PubMed

    Amills, M; Ramírez, O; Tomàs, A; Badaoui, B; Marmi, J; Acosta, J; Sànchez, A; Capote, J

    2009-06-01

    We have analysed the genetic diversity of South and Central American (SCA) goats by partially sequencing the mitochondrial control region of 93 individuals with a wide geographical distribution. Nucleotide and haplotype diversities reached values of 0.020 +/- 0.00081 and 0.963 +/- 0.0012 respectively. We have also observed a rather weak phylogeographic structure, with almost 69% of genetic variation included in the within-breed variance component. The topology of a median-joining network analysis including 286 European, Iberian, Atlantic and SCA mitochondrial sequences was very complex, with most of the haplotypes forming part of independent small clusters. SCA sequences showed a scattered distribution throughout the network, and clustering with Spanish and Portuguese sequences occurred only occasionally, not allowing the distinguishing of a clear Iberian signature. Conversely, we found a prominent cluster including Canarian, Chilean, Argentinian and Bolivian mitochondrial haplotypes. This result was independently confirmed by constructing a Bayesian phylogenetic tree (posterior probability of 0.97). Sharing of mitochondrial haplotypes by SCA and Canarian goats suggests that goat populations from the Atlantic archipelagos, where Spanish and Portuguese ships en route to the New World used to stow food and supplies, participated in the foundation of SCA caprine breeds.

  18. Role of Central American biomass burning smoke in increasing tornado severity in the US

    NASA Astrophysics Data System (ADS)

    Saide, P. E.; Spak, S.; Pierce, R.; Otkin, J.; Rabin, R.; Schaack, T.; Heidinger, A. K.; da Silva, A.; Kacenelenbogen, M. S.; Redemann, J.; Carmichael, G. R.

    2013-12-01

    Violent tornadoes in the Southeast and Central US during spring are often accompanied by smoke from biomass burning in Central America. We analyzed the effect of smoke on a historic severe weather outbreak that occurred 27 April 2011 using a coupled aerosol, chemistry and weather model (WRF-Chem) and a suite of satellite and ground-based observations. Smoke from Central American biomass burning was present in the boundary layer and lower free troposphere before and during the storm outbreak. Simulations show that adding smoke to the environment already conducive to severe thunderstorm development increases the likelihood of significant tornado occurrence, which is assessed by analyzing effects of smoke on meteorological conditions (tornado parameters) used by prediction centers to forecast tornado occurrence and severity. Smoke effects generate slightly lower rain rates and cloud top heights, indicating no evidence of storm invigoration for these storms and instead pointing towards convection inhibition. Further analysis shows that there are two mechanisms responsible for the parameter intensification: First, through indirect effects, stratiform clouds present during and before the outbreak became optically thicker, which reduced the amount of solar radiation reaching the ground and produced more stable conditions and higher low-level shear in the mixed layer. Second, through semi-direct effects, soot contained in the smoke heated the aerosol layer stabilizing the atmosphere and enhancing cloud cover below the aerosol layer, producing a more stable boundary layer and conditions leading to higher probability of violent tornadoes. The inclusion of aerosol-cloud-radiation interactions in weather forecasts may help improve the predictability of these extreme events, which can improve the timeliness and accuracy of severe weather alerts within future operational forecast systems. Left panel: Back trajectories from the beginning of violent tornado tracks, with circles

  19. Miocene Mammals and Central American Seaways: Fauna of the Canal Zone indicates separation of Central and South America during most of the Tertiary.

    PubMed

    Whitmore, F C; Stewart, R H

    1965-04-09

    The presence of Miocene mammals of North American affinity in the Panama Canal Zone indicates that Central America was attached to North America. That this attachment was a broad and stable land mass is shown by the close relation of the Panama Miocene herbivores to the widely distributed Miocene herbivore fauna of North America. A continuous connection existed probably throughout the Tertiary, to the west and north of the isthmian region, but the tectonically active isthmus probably was broken up into an archipelago during most of Tertiary time. Between the islands ran the Strait of Panama; from time to time parts of the isthmian area were connected to the stable land to the west, allowing eastward migration of land animals. The mammals of North American affinity in the Cucaracha Formation were found only a few kilometers from the western end of the San Blas Area, a stable land mass in eastern Panama that was separated from South America by the Bolivar Trough during most of the interval between Oligocene and Pliocene time (16). The Strait of Panama was a less stable barrier than the Bolivar Trough; this being so, it is likely that the San Blas Area was inhabited by land animals of North American rather than South American affinity. Thus, the disappearance of the Bolivar seaway in Pliocene time would have allowed, probably for the first time, mingling of the North and South American mammal faunas.

  20. Maternal epigenetics and methyl supplements affect agouti gene expression in A{sup vy}/a mice

    SciTech Connect

    Wolff, G.L.

    1998-08-01

    Viable yellow (A{sup vy}/a) mice are larger, obese, hyperinsulinemic, more susceptible to cancer, and, on average, shorter lived than their non-yellow siblings. They are epigenetic mosaics ranging from a yellow phenotype with maximum ectopic agouti overexpression, through a continuum of mottled agouti/yellow phenotypes with partial agouti overexpression, to a pseudoagouti phenotype with minimal ectopic expression. Pseudoagouti A{sup vy}/a mice are lean, healthy, and longer lived than their yellow siblings. Here the authors report that feeding pregnant black a/a dams methyl-supplemented diets alters epigenetic regulation of agouti expression in their offspring, as indicated by increased agouti/black mottling in the direction of the pseudoagouti phenotype. They also present confirmatory evidence that epigenetic phenotypes are maternally heritable. Thus A{sup vy} expression, already known to be modulated by imprinting, strain-specific modification, and maternal epigenetic inheritance, is also modulated by maternal diet. These observations suggest, at least in this special case, that maternal dietary supplementation may positively affect health and longevity of the offspring. Therefore, this experimental system should be useful for identifying maternal factors that modulate epigenetic mechanisms, especially DNA methylation, in developing embryos.

  1. Allelic Variation within the Emv-15 Locus Defines Genomic Sequences Closely Linked to the agouti Locus on Mouse Chromosome 2

    PubMed Central

    Siracusa, Linda D.; Russell, Liane B.; Jenkins, Nancy A.; Copeland, Neal G.

    1987-01-01

    Gene(s) at the agouti locus act within the microenvironment of the hair follicle to switch pigment synthesis in the melanocyte between eumelanin (black or brown pigment) and phaeomelanin (yellow pigment). Many phenotypic variants of this locus have been described. The mechanism(s) of gene action causing such variation in coat-color phenotype is not known. The close linkage of an endogenous ecotropic murine leukemia provirus, Emv-15 , to the lethal yellow mutation of the agouti locus provides a means to molecularly access genes at or near the agouti locus. We have identified and used a unique mouse sequence flanking the Emv-15 provirus to define three alleles of the Emv-15 locus. We found a correlation between the presence of specific Emv-15 alleles and the origins of specific agouti locus mutations, confirming close linkage. However, we found some exceptions which suggest that the Emv-15 locus is closely linked to, but genetically separable from, the agouti locus. PMID:2822532

  2. Ectopic expression of the agouti gene in transgenic mice causes obesity, features of type II diabetes, and yellow fur

    SciTech Connect

    Klebig, M.L.; Woychik, R.P.; Wilkinson, J.E.; Geisler, J.G. |

    1995-05-23

    Mice that carry the lethal yellow (A{sup y}) or viable yellow (A{sup vy}) mutation, two dominant mutations of the agouti (a) gene in mouse chromosome 2, exhibit a phenotype that includes yellow fur, marked obesity, a form of type II diabetes associated with insulin resistance, and an increased susceptibility to tumor development. Molecular analyses of these and several other dominant {open_quotes}obese yellow{close_quotes} a-locus mutations suggested that ectopic expression of the normal agouti protein gives rise to this complex pleiotropic phenotype. We have now tested this hypothesis directly by generating transgenic mice that ectopically express an agouti cDNA clone encoding the normal agouti protein in all tissues examined. Transgenic mice of both sexes have yellow fur, become obese, and develop hyperinsulinemia. In addition, male transgenic mice develop hyperglycemia by 12-20 weeks of age. These results demonstrate conclusively that the ectopic agouti expression is responsible for most, if not all, of the phenotypic traits of the dominant, obese yellow mutants. 42 refs., 5 figs.

  3. 'A major lobbying effort to change and unify the excise structure in six Central American countries': How British American Tobacco influenced tax and tariff rates in the Central American Common Market.

    PubMed

    Holden, Chris; Lee, Kelley

    2011-05-19

    Transnational tobacco companies (TTCs) may respond to processes of regional trade integration both by acting politically to influence policy and by reorganising their own operations. The Central American Common Market (CACM) was reinvigorated in the 1990s, reflecting processes of regional trade liberalisation in Latin America and globally. This study aimed to ascertain how British American Tobacco (BAT), which dominated the markets of the CACM, sought to influence policy towards it by member country governments and how the CACM process impacted upon BAT's operations. The study analysed internal tobacco industry documents released as a result of litigation in the US and available from the online Legacy Tobacco Documents Library at http://legacy.library.ucsf.edu/. Documents were retrieved by searching the BAT collection using key terms in an iterative process. Analysis was based on an interpretive approach involving a process of attempting to understand the meanings of individual documents and relating these to other documents in the set, identifying the central themes of documents and clusters of documents, contextualising the documentary data, and choosing representative material in order to present findings. Utilising its multinational character, BAT was able to act in a coordinated way across the member countries of the CACM to influence tariffs and taxes to its advantage. Documents demonstrate a high degree of access to governments and officials. The company conducted a coordinated, and largely successful, attempt to keep external tariff rates for cigarettes high and to reduce external tariffs for key inputs, whilst also influencing the harmonisation of excise taxes between countries. Protected by these high external tariffs, it reorganised its own operations to take advantage of regional economies of scale. In direct contradiction to arguments presented to CACM governments that affording the tobacco industry protection via high cigarette tariffs would safeguard

  4. 'A major lobbying effort to change and unify the excise structure in six Central American countries': How British American Tobacco influenced tax and tariff rates in the Central American Common Market

    PubMed Central

    2011-01-01

    Background Transnational tobacco companies (TTCs) may respond to processes of regional trade integration both by acting politically to influence policy and by reorganising their own operations. The Central American Common Market (CACM) was reinvigorated in the 1990s, reflecting processes of regional trade liberalisation in Latin America and globally. This study aimed to ascertain how British American Tobacco (BAT), which dominated the markets of the CACM, sought to influence policy towards it by member country governments and how the CACM process impacted upon BAT's operations. Methods The study analysed internal tobacco industry documents released as a result of litigation in the US and available from the online Legacy Tobacco Documents Library at http://legacy.library.ucsf.edu/. Documents were retrieved by searching the BAT collection using key terms in an iterative process. Analysis was based on an interpretive approach involving a process of attempting to understand the meanings of individual documents and relating these to other documents in the set, identifying the central themes of documents and clusters of documents, contextualising the documentary data, and choosing representative material in order to present findings. Results Utilising its multinational character, BAT was able to act in a coordinated way across the member countries of the CACM to influence tariffs and taxes to its advantage. Documents demonstrate a high degree of access to governments and officials. The company conducted a coordinated, and largely successful, attempt to keep external tariff rates for cigarettes high and to reduce external tariffs for key inputs, whilst also influencing the harmonisation of excise taxes between countries. Protected by these high external tariffs, it reorganised its own operations to take advantage of regional economies of scale. In direct contradiction to arguments presented to CACM governments that affording the tobacco industry protection via high

  5. Molecular basis of the pleiotropic phenotype of mice carrying the hypervariable yellow (A{sup hvy}) mutation at the agouti locus

    SciTech Connect

    Argeson, A.C.; Nelson, K.K.; Siracusa, L.D.

    1996-02-01

    The murine agouti locus regulates a switch in pigment synthesis between eumelanin (black/brown pigment) and phaeomelanin (yellow/red pigment) by hair bulb melanocytes. We recently described a spontaneous mutation, hypervariable yellow (A{sup hvy}) and demonstrated that A{sup hvy} is responsible for the largest range of phenotypes yet identified at the agouti locus, producing mice that are obese with yellow coats to mice that are of normal weight with black coats. Here, we show that agouti expression is altered both temporally and spatially in A{sup hvy} mutants. Agouti expression levels are positively correlated with the degree of yellow pigmentation in individual A{sup hvy} mice, consistent with results from other dominant yellow agouti mutations. Sequencing of 5{prime} RACE and genomic PCR products revealed that A{sup hvy} resulted from the integration of an intracisternal A particle (IAP) in an antisense orientation within the 5{prime} untranslated agouti exon 1C. This retrovirus-like element is responsible for deregulating agouti expression in A{sup hvy} mice; agouti expression is correlated with the methylation state of CpG residues in the IAP long terminal repeat as well as in host genomic DNA. In addition, the data suggest that the variable phenotype of A{sup hvy} offspring is influenced in part by the phenotype of their A{sup hvy} female parent. 42 refs., 7 figs., 1 tab.

  6. Structural and ultrastructural features of the agouti tongue (Dasyprocta aguti Linnaeus, 1766).

    PubMed

    Ciena, Adriano Polican; de Sousa Bolina, Cristina; de Almeida, Sonia Regina Yokomizo; Rici, Rose Eli Grassi; de Oliveira, Moacir Franco; da Silva, Marcelo Cavenaghi Pereira; Miglino, Maria Angélica; Watanabe, Ii-sei

    2013-08-01

    The agouti (Dasyprocta aguti Linnaeus, 1766) is a wild rodent belonging to the family Dasyproctidae that is found throughout Brazil and feeds on fruits and seeds. The aim of the present study was to describe the following features of the tongue of agouti: its morphological structures, the three-dimensional characteristics of the lingual papillae surface, the connective tissue cores (CTCs) and the epithelial cell ultrastructure. Four types of papillae were observed on the dorsal surface of the tongue with a triangular shape: filiform, fungiform, foliate and vallate. Filiform papillae were distributed throughout the tongue surface, and removal of the epithelial surface revealed conical CTCs and multifilaments. Fungiform papillae were observed in the rostral and middle regions, whereas foliate papillae developed in pairs on the lateral margin of the caudal region. Removal of the epithelium in these regions revealed CTCs with parallel laminar conformation. Vallate papillae were arranged in a V-shape in the caudal region, and their CTCs ranged in shape from elongate to ovoid. The ultrastructural components of the dorsal epithelium were the basal, spinous, granular and keratinised layers. A broad area with cytoplasmic projections was identified in the interface region between the lamina propria and the basal layer. Flattened cells with intermediate filaments were observed in the transitional region between spinous and granular layers. The keratinised layer was composed of superimposed epithelial cells where desmosomes and cell-surface microridges were observed. These structural features, including the three-dimensional aspects of the lingual papillae, the CTCs and the epithelial ultrastructure, indicate that when compared with other animals, particularly other rodent species, the morphological features of the tongue of agouti are relatively well developed, especially regarding foliate and vallate papillae.

  7. Structural and ultrastructural features of the agouti tongue (Dasyprocta aguti Linnaeus, 1766)

    PubMed Central

    Ciena, Adriano Polican; Bolina, Cristina de Sousa; de Almeida, Sonia Regina Yokomizo; Rici, Rose Eli Grassi; de Oliveira, Moacir Franco; da da Silva, Marcelo Cavenaghi Pereira; Miglino, Maria Angélica; Watanabe, Ii-sei

    2013-01-01

    The agouti (Dasyprocta aguti Linnaeus, 1766) is a wild rodent belonging to the family Dasyproctidae that is found throughout Brazil and feeds on fruits and seeds. The aim of the present study was to describe the following features of the tongue of agouti: its morphological structures, the three-dimensional characteristics of the lingual papillae surface, the connective tissue cores (CTCs) and the epithelial cell ultrastructure. Four types of papillae were observed on the dorsal surface of the tongue with a triangular shape: filiform, fungiform, foliate and vallate. Filiform papillae were distributed throughout the tongue surface, and removal of the epithelial surface revealed conical CTCs and multifilaments. Fungiform papillae were observed in the rostral and middle regions, whereas foliate papillae developed in pairs on the lateral margin of the caudal region. Removal of the epithelium in these regions revealed CTCs with parallel laminar conformation. Vallate papillae were arranged in a V-shape in the caudal region, and their CTCs ranged in shape from elongate to ovoid. The ultrastructural components of the dorsal epithelium were the basal, spinous, granular and keratinised layers. A broad area with cytoplasmic projections was identified in the interface region between the lamina propria and the basal layer. Flattened cells with intermediate filaments were observed in the transitional region between spinous and granular layers. The keratinised layer was composed of superimposed epithelial cells where desmosomes and cell-surface microridges were observed. These structural features, including the three-dimensional aspects of the lingual papillae, the CTCs and the epithelial ultrastructure, indicate that when compared with other animals, particularly other rodent species, the morphological features of the tongue of agouti are relatively well developed, especially regarding foliate and vallate papillae. PMID:23701183

  8. Construction of Continental Crust at the Central American and Philippines Arc Systems

    NASA Astrophysics Data System (ADS)

    Whattam, S. A.; Stern, R. J.

    2016-12-01

    Whether or not magmatic arcs evolve compositionally with time and the processes responsible remain controversial. Resolution of this question requires reconstructing arc geochemical evolution at the level of discrete arc systems, as has been done for IBM, Central America, and the Greater Antilles. Emphasis should be on arcs built on oceanic crust because interaction with continental crust complicates interpretations. The Philippines are a particularly attractive target because this may be the best example where proto-continental crust has been generated and processed in Cretaceous and younger time. Here, we show how this question could be addressed for the Philippines using the well-studied Central American Volcanic Arc System (CAVAS) as an example. For the CAVAS, we avoided the northern arc segment because these are (Guatemala) or maybe (El Salvador) sections built on continental crust. Geochemical and isotopic data were compiled for 1031 samples of lavas and intrusive rocks from the 1100 km-long segment built on thickened, initially plume-derived oceanic crust over its 75 million year lifespan (Panama, Costa Rica, Nicaragua) . The most striking observation is the overall evolution of the CAVAS to more incompatible element enriched and ultimately continental-like compositions with time. Models entailing progressive arc magmatic enrichment are generally supported by the CAVAS record. Progressive enrichment of the oceanic CAVAS with time reflects changes in mantle wedge composition and decreased melting due to arc crust thickening, which was kick-started by the involvement of enriched plume mantle. Progressive crustal thickening and associated changes in the sub-arc thermal regime resulted in decreasing degrees of partial melting over time, which allowed for progressive enrichment of the CAVAS and ultimately the production of continental-like crust in Panama and Costa Rica by 16-10 Ma. Our similar study of the Philippine Arc system is in its infancy but earlier

  9. Prenatal development of the agouti (Dasyprocta prymnolopha Wagler, 1831): External features and growth curves.

    PubMed

    Fortes, Eunice Anita de Moura; Ferraz, Maíra Soares; Bezerra, Dayseanny Oliveira; Júnior, Aírton Mendes Conde; Cabral, Rosa Maria; Sousa, Francisco das Chagas Araújo; Almeida, Hatawa Melo; Pessoa, Gerson Tavares; Menezes, Danilo José Ayres de; Guerra, Sérgio Paulo Lima; Sampaio, Ivan Barbosa Machado; Assis Neto, Antônio Chaves; Carvalho, Maria Acelina Martins de

    2013-08-01

    The gestation period in agoutis can range from 104 to 120 days. Knowledge regarding the morphological characteristics of embryos and fetuses is important as a base for studies in reproduction biotechnology, such as in vitro fertilization, embryo transfer and helps in determining congenital anomalies during the development phase. Thus, given the importance and lack of information about agouti embryology, the objective of this study was to characterize the external morphology and define the biometry of embryos and fetuses, at different days of development. Nine females were submitted to daily colpocytology to identify the estrus, confirm mating and identify day zero of the gestation. When the mating was confirmed they were weighed, underwent abdominal ultrasonography and surgery was conducted on the females at the gestational ages of 25, 30, 35, 40, 45, 50, 75 and 100 days. Sixteen embryos/fetuses were weighed and measured. Agouti embryos at 25 days after mating are "C" shaped, with primitive structures, 0.4±0.01cm crown-rump and weighed 0.06±0.01g; at 30 days after mating the crown-rump was 0.95±0.07cm and weighed 0.28±0.00g; at 35 days after mating the crown-rump was 155±0.07cm and weighed 0.38±0.01g; at 40 days after mating the crown-rump was 2.25±0.21cm and weighed 1.25±0.07g; at 45 days after mating the crown-rump was 3.45±0.35cm and weighed 2.75±0.64g; at 50 days after mating the crown-rump was 5.0±0.3cm and weighed 7.01±2.6g; at 75 days after mating, the skin was dark, the crown-rump was 10.0±0.14cm and weighed 55.2±0.07g. At 100 days after mating, the crown-rump was 13.8±0.49cm and fetuses weighed 136.7±9.40g. Based on the morphological data assessed the embryo and fetus age could be assessed and the size and average weight of agouti embryos was established. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Genetic differentiation and species cohesion in two widespread Central American Begonia species

    PubMed Central

    Twyford, A D; Kidner, C A; Ennos, R A

    2014-01-01

    Begonia is one of the ten largest plant genera, with over 1500 species. This high species richness may in part be explained by weak species cohesion, which has allowed speciation by divergence in allopatry. In this study, we investigate species cohesion in the widespread Central American Begonia heracleifolia and Begonia nelumbiifolia, by genotyping populations at microsatellite loci. We then test for post-zygotic reproductive barriers using experimental crosses, and assess whether sterility barriers are related to intraspecific changes in genome size, indicating major genome restructuring between isolated populations. Strong population substructure was found for B. heracleifolia (FST=0.364, F′ST=0.506) and B. nelumbiifolia (FST=0.277, F′ST=0.439), and Bayesian admixture analysis supports the division of most populations into discrete genetic clusters. Moderate levels of inferred selfing (B. heracleifolia s=0.40, B. nelumbiifolia s=0.62) and dispersal limitation are likely to have contributed to significant genetic differentiation (B. heracleifolia Jost's D=0.274; B. nelumbiifolia D=0.294). Interpopulation crosses involving a divergent B. heracleifolia population with a genome size ∼10% larger than the species mean had a ∼20% reduction in pollen viability compared with other outcrosses, supporting reproductive isolation being polymorphic within the species. The population genetic data suggest that Begonia populations are only weakly connected by gene flow, allowing reproductive barriers to accumulate between the most isolated populations. This supports allopatric divergence in situ being the precursor of speciation in Begonia, and may also be a common speciation mechanism in other tropical herbaceous plant groups. PMID:24220088

  11. Genetic differentiation and species cohesion in two widespread Central American Begonia species.

    PubMed

    Twyford, A D; Kidner, C A; Ennos, R A

    2014-04-01

    Begonia is one of the ten largest plant genera, with over 1500 species. This high species richness may in part be explained by weak species cohesion, which has allowed speciation by divergence in allopatry. In this study, we investigate species cohesion in the widespread Central American Begonia heracleifolia and Begonia nelumbiifolia, by genotyping populations at microsatellite loci. We then test for post-zygotic reproductive barriers using experimental crosses, and assess whether sterility barriers are related to intraspecific changes in genome size, indicating major genome restructuring between isolated populations. Strong population substructure was found for B. heracleifolia (FST=0.364, F'ST=0.506) and B. nelumbiifolia (FST=0.277, F'ST=0.439), and Bayesian admixture analysis supports the division of most populations into discrete genetic clusters. Moderate levels of inferred selfing (B. heracleifolia s=0.40, B. nelumbiifolia s=0.62) and dispersal limitation are likely to have contributed to significant genetic differentiation (B. heracleifolia Jost's D=0.274; B. nelumbiifolia D=0.294). Interpopulation crosses involving a divergent B. heracleifolia population with a genome size ∼10% larger than the species mean had a ∼20% reduction in pollen viability compared with other outcrosses, supporting reproductive isolation being polymorphic within the species. The population genetic data suggest that Begonia populations are only weakly connected by gene flow, allowing reproductive barriers to accumulate between the most isolated populations. This supports allopatric divergence in situ being the precursor of speciation in Begonia, and may also be a common speciation mechanism in other tropical herbaceous plant groups.

  12. Support for Astronaut's View of Mexican/ Central American Fires and on-Line Earth Observations Training Manual

    NASA Technical Reports Server (NTRS)

    Kaminski, Charles F., Jr.

    1999-01-01

    A small project to compile remote sensing and in-site data to review the processes leading to the May 1998 Mexican/Central American fires was undertaken. A web page based on this project was assembled. The second project initiated involved an interactive and on-line program that will replace the paper version of the Earth Observations Preflight Training Manual. Technical support was provided to Prof. Marvin Glasser as needed.

  13. Amanita viscidolutea, a new species from Brazil with a key to Central and South American species of Amanita section Amanita.

    PubMed

    Menolli, Nelson; Capelari, Marina; Baseia, Iuri Goulart

    2009-01-01

    We described and illustrated Amanita viscidolutea sp. nov. from specimens collected in the state of Rio Grande do Norte, northeastern Brazil. The main characteristics of the new species are its yellow pileus with white margin, the viscidity of the pileal surface, an exannulate stipe and inamyloid basidiospores. We also present an artificial dichotomous key to Central and South American species of Amanita (subgenus Amanita) section Amanita.

  14. Miocene latitudinal climatic and topographic variability within the central North American Cordillera

    NASA Astrophysics Data System (ADS)

    Gébelin, Aude; Mulch, Andreas; Teyssier, Christian; Heizler, Matthew

    2010-05-01

    The long-term climatic evolution and atmospheric circulation patterns of the Earth are influenced by the topography of large mountain chains whose topography is in turn controlled by links and feedbacks of surface processes and those acting within the Earth's interior. Stable isotopes in precipitation change systematically with elevation in many modern mountain ranges and have become an increasingly important tool in reconstructing the long-term topographic and climatic evolution of the world's largest mountain ranges. Here, we present stable isotope data from meteoric fluids trapped in orogen-scale deformation zones and associated fault-bounded basin sediments that record paleoelevation and also link the geodynamics of orogens with the overall long-term landscape and climate histories. To reconstruct the Cenozoic paleoelevation history of the central part of the North American Cordillera, we focus on the metamorphic core complexes of the Snake Range (Nevada) and Buckskin Mountains (Arizona). The Snake Range and Buckskin Mountains represent both classic examples of normal fault-bounded metamorphic core complexes that developed as a consequence of Oligocene Miocene extension of the Basin and Range Province. Synkinematic muscovites collected systematically over the top-300 m of section within the Snake Range detachment reveal a pattern of increasingly younger 40Ar/39Ar ages (26.9 Ma to 21.3 Ma) from the top to the bottom of the detachment. Across the same section dD muscovite values as low as -150 per mil occur at the top of the detachment zone and attain progressively higher values of up to -72 per mil towards the bottom of the section. This hydrogen stable isotope trend suggests that meteoric fluids percolated 10s to 100s of meters into the ductile segment of the detachment over the time scale of mylonitic deformation (ca. 27 to 23 Ma). In contrast, dDmuscovite values of similarly aged mylonitic quartzites from the Buckskin Mountains are much higher and range

  15. Long-Term Drop in Caribbean Marine Export Productivity with the Demise of the Central American Seaway

    NASA Astrophysics Data System (ADS)

    Norris, R. D.; Trumbo, S. K.

    2015-12-01

    The progressive closing of the Central American Seaway ~3-7 Ma substantially altered the surface ocean salinity, nutrient content, and biology of the Caribbean Sea and Eastern Equatorial Pacific Ocean. Data from fossil plankton, reef development and oceanographic models of the shoaling Central American Seaway suggest that there was a distinct change in Caribbean productivity with closure of the seaway, but there has not been a detailed comparison of export production between the two ocean basins. Here we show that export production gradually decreased in the Caribbean starting about 2.7 Ma while remaining relatively stable in the eastern equatorial Pacific. Data are derived from 0-5.3 Ma XRF records of Caribbean Site ODP 999 and Pacific Site ODP 846 at ~600-1000 year resolution. Caribbean export production falls during glacial phases in response to ventilation of the tropical thermocline by increasingly nutrient-starved Glacial North Atlantic Intermediate Water. In contrast, Caribbean production peaks during interglacials when nutrient-rich Antarctic Intermediate Water ventilates the tropical thermocline. Export production in both the eastern Pacific and Caribbean is governed mostly by high latitude nutrient sources as seen in the dominance of high latitude orbital forcing. The gradual intensification of Caribbean oligotrophy may be responsible for the well documented delay in extinction of Caribbean reef associated fauna relative to closure of the central American Seaway. The increasing nutrient starvation of the Caribbean during glacial events may also have rendered Caribbean reef corals unusually susceptible to anthropogenic nutrient loads in modern times.

  16. Comparison among different cryoprotectants for cryopreservation of epididymal sperm from agouti (Dasyprocta leporina).

    PubMed

    Castelo, T S; Silva, A M; Bezerra, L G P; Costa, C Y M; Lago, A E A; Bezerra, J A B; Campos, L B; Praxedes, E C G; Silva, A R

    2015-12-01

    We verify the effects of different cryoprotectants on the cryopreservation of agouti (Dasyprocta leporina) epididymal sperm. We used 16 pairs of testes-epididymis complexes of sexually mature animals. We immediately evaluated epididymal sperm obtained by retrograde flushing for concentration, motility, vigor, viability, osmotic response, and morphology. Samples were extended in a coconut water extender plus 20% egg yolk, containing glycerol, ethylene glycol, dimethylsulfoxide - DMSO, or dimethylformamide. Finally, samples were stored in 0.25 mL straws, frozen in liquid nitrogen, and thawed after one week, being reevaluated and assessed for membrane integrity using fluorescent probes. The higher values for postthawing sperm motility, vigor, and membrane integrity were achieved by the usage of glycerol, when compared to ethylene glycol and dimethylformamide (P < 0.05); however, no differences were found between glycerol and DMSO (P > 0.05). All cryoprotectants provided a similar effect on the preservation of sperm morphology, osmotic response, and viability (P > 0.05). Therefore, here onwards, there was testing of glycerol and DMSO at 3 and 6% concentrations using the same freezing-thawing protocol reported previously. As the main result, DMSO at 6% concentration provided a decrease in sperm parameters, as well as in the chromatin integrity and in the binding capability of sperm. In conclusion, glycerol 3 or 6% and DMSO 3% can be used as alternative cryoprotectants for agouti epididymal sperm cryopreservation.

  17. Arterial supply of the penis in agoutis (Dasyprocta prymnolpha, Wagler, 1831).

    PubMed

    de Carvalho, M A M; Machado Junior, A A N; Bezerra E Silva, R A; Menezes, D J A; Conde Júnior, A M; Righi, D A

    2008-02-01

    The arterial vascularization of agoutis' penis (Dasyprocta prymnolopha) were analysed using ten male adults from 'Núcleo de Estudos e Preservação de Animais Silvestres da Universidade Federal do Piauí' (FUFPI/IBAMA n degrees 02/99). Among the total number of specimens, six animals had natural death and were members of the research collection of the Laboratory of Anatomy, and four were killed after anaesthesia. Stained bi-centrifugated-Cis-I-4 latex was injected in arterial vessels responsible for penis vascularization throughout the abdominal portion of aorta. The samples were fixed in 10% formaldehyde solution and arteries were dissected. The penile artery is originated as a branch of internal pudendal artery. At the level of ischiatic arch, the penile artery project two branches, the penile dorsal and the deep arteries; those arteries irrigates the penile dorsal surface and the corpus cavernosum penis. The penile dorsal arteries have an independent course up to the glans penis. Based on the conditions of this work a remarkable similarity regarding the distribution of vessels destined to the agouti penis when compared to other domestic, wild and lagomorph rodents as rabbits.

  18. The Experience of a Native American English Professor in Central Pennsylvania

    ERIC Educational Resources Information Center

    Sellers, Stephanie

    2003-01-01

    The author is a part-time English faculty at a wealthy, 95 percent Anglo, liberal arts college in Pennsylvania, and she is a candidate for a PhD in Native American studies. College administrators and her colleagues know that she is a tribally enrolled Native American (Shawnee). She used her tribal enrollment card for Form I-9 identification when…

  19. Exhumation of the Panama basement complex and basins: Implications for the closure of the Central American seaway

    NASA Astrophysics Data System (ADS)

    Ramírez, Diego A.; Foster, David A.; Min, Kyoungwon; Montes, Camilo; Cardona, Agustín.; Sadove, Gephen

    2016-05-01

    The emergence of the Central American isthmus occurred episodically from Eocene to Pliocene time and was caused by a series of tectonic and volcanic processes. Results from zircon U-Pb geochronology, zircon (U-Th)/He (ZHe) and apatite (U-Th)/He (AHe) thermochronology, and zircon Lu-Hf isotopic data from sedimentary (sandstones and recent river sands) and plutonic rocks from the Azuero Peninsula and Central Panama document the exhumation and uplift history of the Panamanian basement complex. Our data support previous paleobotanical and thermochronological studies that suggest that by middle Eocene time some areas of Central Panama and Azuero Peninsula were exposed above sea level as a series of islands surrounded by shallow open marine waters. The Gatuncillo, Cobachón and Tonosí formations were deposited during this partial emergence. Transtension in the Oligocene-early Miocene produced various pull-apart basins (e.g., the Canal Basin) and local uplift that exhumed the Eocene strata (Gatuncillo and Cobachón formations). This event probably reduced circulation between the Pacific Ocean and the Caribbean Sea. The Tonosí Formation records late Miocene to Pleistocene cooling and exhumation, which may be related to uplift above the subducting Coiba Ridge. These results suggest that the emergence of the Isthmus of Panama followed a series of diachronous events that led to the final closure of the Central American seaway.

  20. A conceptual model for the link between Central American biomass burning aerosols and severe weather over the south central United States

    NASA Astrophysics Data System (ADS)

    Wang, Jun; van den Heever, Susan C.; Reid, Jeffrey S.

    2009-01-01

    Each spring, smoke particles from fires over the Yucatan Peninsula and south Mexico cross over the Gulf of Mexico into the United States (US) under the control of moist oceanic air flow from the southwestern branch of the subtropical (Bermuda) high. Smoke can be transported deep into the south central US, where dry lines and warm conveyor belts are frequently formed and cause deep convection and severe weather. Lyons et al (1998 Science 282 77-80) and Murray et al (2000 Geophys. Res. Lett. 27 2249-52) noticed a ~50% increase of lightning along the smoke transport path over the south central US during the May 1998 Central American smoke episode. Here we present a conceptual model of coherent microphysical and meteorological mechanisms through which smoke may impact convective clouds and subsequently result in more severe weather over the south central US. The conceptual model depicts a chain of processes in which smoke particles are first activated as cloud condensation nuclei when they are entrained into the warm conveyor belt, a convective zone formed over the south central US as a result of the encounter between the mid-latitude trough and the subtropical Bermuda high. As the convection continues with deepening of the mid-latitude trough, the greater concentration of water cloud condensation nuclei delays the warm rain processes, enhances the development of ice clouds, and invigorates the updrafts, all of which contribute to the formation of severe weather such as hail and lightning. The conceptual model is based on the reasoning of physical mechanisms revealed in previous studies (over the tropical biomass region), and is supported here through the analysis of satellite data, ground observations, aerosol transport model results, and idealized cloud resolving simulations of a day in May 2003 when record tornado events occurred over the south central US. Further assessment of this conceptual model is discussed for future investigations.

  1. [Musculoskeletal pain in Central American workers: results of the First Survey on Working Conditions and Health in Central America].

    PubMed

    Rojas, Marianela; Gimeno, David; Vargas-Prada, Sergio; Benavides, Fernando G

    2015-08-01

    Examine the prevalence of musculoskeletal pain (MSP) in the six Spanish-speaking countries of Central America using a single standardized instrument, the First Survey on Working Conditions and Health in Central America in workers from all manual and non-manual labor sectors, using social security coverage as an indicator of formal versus informal employment. The workers (n = 12 024) were surveyed in their homes. The age-adjusted prevalence of MSP during the previous month was calculated for pain in the back (upper, or cervical; middle, or thoracic; and lower, or lumbar) and arm joints (shoulder, elbow, and wrist). Prevalence was estimated by sex, occupation (manual or non-manual), economic sector (agriculture, industry, or services), and social security coverage. Poisson regression models were used to calculate the prevalence rates and 95% confidence intervals, with stratification by country and anatomical site. By sites, the age-adjusted prevalence of cervical-dorsal MSP was the highest, especially in El Salvador (47.8%) and Nicaragua (45.9%), and lumbar MSP was less prevalent, especially in Panama (12.8%) and Guatemala (14.8%). After additional adjustments, the prevalence of MSP was higher in women and manual workers for all the sites and in all the countries. There were no differences in MSP in terms of social security coverage or sector of economic activity. The high prevalence of MSP in Central America, regardless of sector of activity or social security coverage, indicates that the prevention of MSP should be a priority in occupational health programs in low- and middle-income countries, especially for women and manual workers.

  2. The Closure History of the Central American Seaway and its Relationship to Ocean Circulation and Climate

    NASA Astrophysics Data System (ADS)

    Waite, A. J.; Martin, E. E.; Lawrence, K. T.; Ladlow, C. G.; Newkirk, D.

    2014-12-01

    Paleoceanographic and ecologic studies suggest that gradual shoaling of the Central American Seaway (CAS) as the Isthmus of Panama rose between ~13 to 2 Ma caused a stepwise shutdown of deep, intermediate, and shallow Pacific water flow through the seaway into the Caribbean. This diminishing communication is thought to have significantly influenced surface currents, ocean circulation at depth, and ultimately regional and global climate. However, new studies of Panama's volcanic/tectonic history suggest the isthmus rose much earlier than previous estimates, calling into question many of our accepted implications for this gateway event under the 'Panama Hypothesis,' including strengthened thermohaline circulation, North Atlantic Deep Water production, increased North Atlantic temperature, and ties to Northern Hemisphere glaciation. Despite considerable research, few paleoceanographic studies have directly examined the possibility of earlier events in the closure history of the CAS and thus the precise linkages and timing are not well defined. To investigate early restricted CAS flow related to sill formation or pulsed exhumation events, we examine two sets of independent paleoceanographic reconstructions from Ocean Drilling Program sediment cores from the region. We assess the presence of Pacific waters within the Caribbean over the last 30 Ma via the Nd-isotopic composition of fish teeth from several Caribbean sites; these records point to sustained transport of Pacific waters into the Caribbean from at least 30 to 10 Ma. Further, alkenone-derived sea surface temperature (SST) reconstructions from the Eastern Equatorial Pacific (EEP) indicate the presence of consistently warm (>27 °C) waters in the EEP from ~12 to ~5 Ma, after which time SSTs at sites within the modern cold tongue begin to cool appreciably. The SST data imply that the EEP cold tongue, which some studies suggest is linked in part to the rise of the Panamanian isthmus, did not develop until after 5

  3. Helium and Carbon Relationships in Geothermal Fluids From the Central American arc in Costa Rica

    NASA Astrophysics Data System (ADS)

    Shaw, A. M.; Hilton, D. R.; Fischer, T. P.; Zimmer, M. M.; Alvarado, G.

    2001-12-01

    A fundamental aim of arc-related studies is to quantify the flux of elements from the various subduction zone reservoirs: a) the mantle wedge, b) the overlying arc crust through which the magmas erupt and c) both the oceanic basement and sedimentary veneer of the subducting slab. In the case of estimating the CO2 mass balance at convergent margins, one approach has been to couple CO2 and He measurements (isotopes and relative abundances) which allows both identification and quantitative assessment of the various contributors to the magmatic output. The Central American arc presents a unique opportunity to consider the He-C approach given prior studies which show dramatic variations in the angle of subduction, the amount and type of sediments subducted and the crustal thickness. The Costa Rica subduction zone is particularly intriguing due to the pronounced steepening of the down-going slab to the north and the occurrence of carbonate rich sediments on the down-going plate. Here, we report 3He/4He ratios, He, Ne, and CO2 abundances as well as δ 13C values for volatiles from the volcanic output along the Costa Rican segment utilising fumaroles, geothermal wells, water springs and bubbling hot springs. The results from our study show the following: 1) 3He/4He ratios of the southern volcanoes (Turrialba, Irazu and Poas) are slightly higher (6.9-8.1 RA) than those of Miravalles and Rincon de la Vieja in the north (5.1-6.8 RA), 2) water spring samples show poor preservation of magmatic gases (low 3He/4He; very high CO2/3He) relative to other sampling media, 3) CO2/3He ratios range from 9.9-27 x 109 in the south to 13-78 x 109 in the north, and 4) δ 13C values trend from isotopically heavier values in the north ( ~ -1.0 ‰ at Rincon de la Vieja) to lighter more MORB-like values in the south ( ~ -6.1 ‰ at Poas volcano). The He-CO2 relationships are consistent with a large input of marine carbonate/limestone carbon to magma sources in Costa Rica. The average ratio of

  4. Alopecia Areata on Vertex as a Potential Pitfall for Misdiagnosis of Central Centrifugal Cicatricial Alopecia in African-American Women.

    PubMed

    Johnson, Courtney M; Miteva, Mariya

    2017-01-01

    Trichoscopy is a noninvasive visualization tool used to more accurately diagnose hair and scalp disorders. Alopecia areata (AA) in the patient of African descent can mimic the early signs of central centrifugal cicatricial alopecia (CCCA), especially if the initial presentation of hair loss occurs on the central scalp. Two African-American women presented with singular round-ovoid patches of decreased hair loss on the central scalp. Given the clinical presentation, CCCA was the working diagnosis. However, using dermoscopy, the patients were found to have exclamation hairs and short broken hairs on a background of honeycomb-like pigmented network and regular pinpoint white dots consistent with AA. The diagnosis was confirmed on biopsy. We demonstrate the role of dermoscopy for diagnosing AA in the patient of African descent.

  5. Bromine release during Plinian eruptions along the Central American Volcanic Arc

    NASA Astrophysics Data System (ADS)

    Hansteen, T. H.; Kutterolf, S.; Appel, K.; Freundt, A.; Perez-Fernandez, W.; Wehrmann, H.

    2010-12-01

    Volcanoes of the Central American Volcanic Arc (CAVA) have produced at least 72 highly explosive eruptions within the last 200 ka. The eruption columns of all these “Plinian” eruptions reached well into the stratosphere such that their released volatiles may have influenced atmospheric chemistry and climate. While previous research has focussed on the sulfur and chlorine emissions during such large eruptions, we here present measurements of the heavy halogen bromine by means of synchrotron radiation induced micro-XRF microanalysis (SR-XRF) with typical detection limits at 0.3 ppm (in Fe rich standard basalt ML3B glass). Spot analyses of pre-eruptive glass inclusions trapped in minerals formed in magma reservoirs were compared with those in matrix glasses of the tephras, which represent the post-eruptive, degassed concentrations. The concentration difference between inclusions and matrix glasses, multiplied by erupted magma mass determined by extensive field mapping, yields estimates of the degassed mass of bromine. Br is probably hundreds of times more effective in destroying ozone than Cl, and can accumulate in the stratosphere over significant time scales. Melt inclusions representing deposits of 22 large eruptions along the CAVA have Br contents between 0.5 and 13 ppm. Br concentrations in matrix glasses are nearly constant at 0.4 to 1.5 ppm. However, Br concentrations and Cl/Br ratios vary along the CAVA. The highest values of Br contents (>8 ppm) and lowest Cl/Br ratios (170 to 600) in melt inclusions occur across central Nicaragua and southern El Salvador, and correlate with bulk-rock compositions of high Ba/La > 85 as well as low La/Yb <5. Thus we observe the maximum magmatic Br-concentrations in the segements of the arc. where the input of sediment and water into the subduction system is largest and the melting column is longest. The largest eruptive emissions of Br into the atmosphere, however, occurred in Guatemala due to the large magnitude of

  6. An obesity-dependent lactation defect in the viable yellow agouti mouse is associated with mammary inflammation

    USDA-ARS?s Scientific Manuscript database

    Maternal obesity is known to delay lactogenesis in breast-feeding women, as well as negatively impact lactation in other species. Obesity is also understood to be associated with inflammation. Work with the viable yellow agouti (Avy) mouse in our laboratory has documented a lactation defect in obese...

  7. Characterization, tissue distribution and regulation by fasting of the agouti family of peptides in the sea bass (Dicentrarchus labrax).

    PubMed

    Agulleiro, Maria Josep; Cortés, Raúl; Leal, Esther; Ríos, Diana; Sánchez, Elisa; Cerdá-Reverter, José Miguel

    2014-09-01

    The melanocortin system is one of the most complex hormonal systems in vertebrates. Atypically, the signaling of melanocortin receptors is regulated by the binding of endogenous antagonists, named agouti-signaling protein (ASIP) and agouti-related protein (AGRP). Teleost specific genome duplication (TSGD) rendered new gene copies in teleost fish and up to four different genes of the agouti family of peptides have been characterized. In this paper, molecular cloning was used to characterize mRNA of the agouti family of peptides in sea bass. Four different genes were identified: AGRP1, ASIP1, AGRP2 and ASIP2. The AGRP1 gene is mainly expressed in the brain whereas ASIP1 is mainly expressed in the ventral skin. Both ASIP2 and AGRP2 are expressed in the brain and the pineal gland but also in some peripheral tissues. Immunocytochemical studies demonstrated that AGRP1 is exclusively expressed within the lateral tuberal nucleus, the homologue of the mammalian arcuate nucleus in fish. Long-term fasting (8-29 days) increased the hypothalamic expression of AGRP1 but depressed AGRP2 expression (15-29 days). In contrast, the hypothalamic expression of ASIP2 was upregulated during short-term fasting suggesting that this peptide could be involved in the short term regulation of food intake in the sea bass.

  8. Central American mothers report family history of depression and alcohol abuse as a predictor of teenage health risk behaviors.

    PubMed

    Maradiegue, Ann

    2010-10-01

    The purpose of this study was to explore the relationships of family history of depression and alcohol abuse as a predictor of health risk behaviors among Central American teenagers. Demographic data were collected from a convenience sample of 101 Central American mothers with a teenage daughter ages 12-17 years who were living in Northern Virginia. The research questions assessed the family history of depression, alcohol abuse, and maternal depression. Scores were calculated to predict risk of teenage health risk behaviors. The Hispanic mothers in this study reported that their teenagers had significant health risk behaviors, including school dropout and expulsion, alcohol and substance use, pregnancy, and gang membership. Family history of depression and alcohol abuse in a first degree relative predicted teenage risk behavior 71% of the time. There is no consensus on a standard screening approach for depression in teenagers. Developing a standardized approach to gathering information from teenagers that includes genetic family traits may have significant effects on interventions for teenage health risk behavior and ways to provide the best services for vulnerable teenagers. The results of this study have implications for nurse practitioners caring for teenagers. ©2010 The Author(s) Journal compilation ©2010 American Academy of Nurse Practitioners.

  9. Prevalence of the Metabolic Syndrome in Central and South American Immigrant Residents of the Washington, DC, Area.

    PubMed

    Gill, Regina M; Khan, Saira A; Jackson, Robert T; Duane, Marguerite

    2017-01-01

    The objective of this study was to estimate the prevalence of Metabolic Syndrome (MetS) and its risk components and then compare differences in the risk components among low-income, uninsured Central and South American recent immigrants to the USA. This cross-sectional survey sampled 1,042 adult patients from a medical clinic in metropolitan Washington, DC. The overall prevalence of the MetS was 26.9% estimated using the modified harmonized definition. The most common abnormal metabolic indicator for women was an elevated BMI ≥ 30 kg/m(2) (36.1%), while, for men, it was an elevated triglyceride level (46.5%). The risk of abnormal MetS indicators increased steadily with increasing BMI. The abnormal indicator combination identifying the most subjects with the MetS included the following: high triglycerides, low HDL cholesterol, and obesity. MetS rates were highest among subjects from El Salvador and Honduras, 31.3% and 28.0%, respectively, and lowest among subjects from Bolivia (21.7%). Dyslipidemia and high BMI increased the likelihood of having the MetS, which is consistent with studies on Mexican Americans in the San Antonio Heart Study and studies within Central and South American countries. This study adds new baseline epidemiological data for largely understudied, low-income, and mostly recent immigrant groups.

  10. Regulation of Agouti-Related Protein and Pro-Opiomelanocortin Gene Expression in the Avian Arcuate Nucleus

    PubMed Central

    Boswell, Timothy; Dunn, Ian C.

    2017-01-01

    The arcuate nucleus is generally conserved across vertebrate taxa in its neuroanatomy and neuropeptide expression. Gene expression of agouti-related protein (AGRP), neuropeptide Y (NPY), pro-opiomelanocortin (POMC), and cocaine- and amphetamine-regulated transcript (CART) has been established in the arcuate nucleus of several bird species and co-localization demonstrated for AGRP and NPY. The proteins encoded by these genes exert comparable effects on food intake in birds after central administration to those seen in other vertebrates, with AGRP and NPY being orexigenic and CART and α-melanocyte-stimulating hormone anorexigenic. We have focused on the measurement of arcuate nucleus AGRP and POMC expression in several avian models in relation to the regulation of energy balance, incubation, stress, and growth. AGRP mRNA and POMC mRNA are, respectively, up- and downregulated after energy deprivation and restriction. This suggests that coordinated changes in the activity of AGRP and POMC neurons help to drive the homeostatic response to replace depleted energy stores in birds as in other vertebrates. While AGRP and POMC expression are generally positively and negatively correlated with food intake, respectively, we review here situations in some avian models in which AGRP gene expression is dissociated from the level of food intake and may have an influence on growth independent of changes in appetite. This suggests the possibility that the central melanocortin system exerts more pleiotropic functions in birds. While the neuroanatomical arrangement of AGRP and POMC neurons and the sensitivity of their activity to nutritional state appear generally conserved with other vertebrates, detailed knowledge is lacking of the key nutritional feedback signals acting on the avian arcuate nucleus and there appear to be significant differences between birds and mammals. In particular, recently identified avian leptin genes show differences between bird species in their tissue

  11. New records of benthic marine algae and Cyanobacteria for Costa Rica, and a comparison with other Central American countries

    NASA Astrophysics Data System (ADS)

    Bernecker, Andrea; Wehrtmann, Ingo S.

    2009-09-01

    We present the results of an intensive sampling program carried out from 2000 to 2007 along both coasts of Costa Rica, Central America. The presence of 44 species of benthic marine algae is reported for the first time for Costa Rica. Most of the new records are Rhodophyta (27 spp.), followed by Chlorophyta (15 spp.), and Heterokontophyta, Phaeophycea (2 spp.). Overall, the currently known marine flora of Costa Rica is comprised of 446 benthic marine algae and 24 Cyanobacteria. This species number is an under estimation, and will increase when species of benthic marine algae from taxonomic groups where only limited information is available (e.g., microfilamentous benthic marine algae, Cyanobacteria) are included. The Caribbean coast harbors considerably more benthic marine algae (318 spp.) than the Pacific coast (190 spp.); such a trend has been observed in all neighboring countries. Compared to other Central American countries, Costa Rica has the highest number of reported benthic marine algae; however, Panama may have a similarly high diversity after unpublished results from a Rhodophyta survey (Wysor, unpublished) are included. Sixty-two species have been found along both the Pacific and Caribbean coasts of Costa Rica; we discuss this result in relation to the emergence of the Central American Isthmus.

  12. Liver-specific expression of the agouti gene in transgenic mice promotes liver carcinogenesis in the absence of obesity and diabetes

    SciTech Connect

    Kuklin, Alexander; Mynatt, Randall; Klebig, Mitch; Kiefer, Laura; Wilkison, William O; Woychik, Richard P; Michaud III, Edward J

    2004-01-01

    Background: The agouti protein is a paracrine factor that is normally present in the skin of many species of mammals. Agouti regulates the switch between black and yellow hair pigmentation by signalling through the melanocortin 1 receptor (Mc1r) on melanocytes. Lethal yellow (Ay) and viable yellow (Avy) are dominant regulatory mutations in the mouse agouti gene that cause the wild- ype protein to be produced at abnormally high levels throughout the body. Mice harboring these mutations exhibit a pleiotropic syndrome characterized by yellow coat color, obesity, hyperglycemia, hyperinsulinemia, and increased susceptibility to hyperplasia and carcinogenesis in numerous tissues, including the liver. The goal of this research was to determine if ectopic expression of the agouti gene in the liver alone is sufficient to recapitulate any aspect of this syndrome. For this purpose, we generated lines of transgenic mice expressing high levels of agouti in the liver under the regulatory control of the albumin promoter. Expression levels of the agouti transgene in the liver were quantified by Northern blot analysis. Functional agouti protein in the liver of transgenic mice was assayed by its ability to inhibit binding of the -melanocyte stimulating hormone ( MSH) to the Mc1r. Body weight, plasma insulin and blood glucose levels were analyzed in control and transgenic mice. Control and transgenic male mice were given a single intraperitoneal injection (10 mg/kg) of the hepatocellular carcinogen, diethylnitrosamine (DEN), at 15 days of age. Mice were euthanized at 36 or 40 weeks after DEN injection and the number of tumors per liver and total liver weights were recorded. Results: The albumin-agouti transgene was expressed at high levels in the livers of mice and produced a functional agouti protein. Albumin-agouti transgenic mice had normal body weights and normal levels of blood glucose and plasma insulin, but responded to chemical initiation of the liver with an increased number

  13. Diet quality and its relationship with central obesity among Mexican Americans: findings from National Health and Nutrition Examination Survey (NHANES) 1999-2012.

    PubMed

    Yoshida, Yilin; Scribner, Richard; Chen, Liwei; Broyles, Stephanie; Phillippi, Stephen; Tseng, Tung-Sung

    2017-05-01

    Using the Healthy Eating Index-2010 (HEI-2010), the present study aimed to examine diet quality and the impact of overall diet quality and its components on central obesity among Mexican-American men and women. Cross-sectional data from NHANES 1999-2012 were used. The HEI-2010 data, including twelve components for a total score of 100, were collected with a 24 h recall interview. Central obesity was defined as a waist circumference of ≥88 cm for women and ≥102 cm for men. Weighted logistic regressions were performed to assess associations between HEI-2010 scores and central obesity. National Health and Nutrition Examination Survey (NHANES) 1999-2012. A total of 6847 Mexican Americans aged ≥20 years with reliable dietary recall status and non-pregnancy status. Higher HEI-2010 total score was associated with lower odds of central obesity in Mexican-American men (OR; 95 % CI=0·98; 0·98, 1·00). Among all Mexican Americans, one-unit higher score of total fruit and sodium (i.e. lower level of intake) was associated with 4 % (0·96; 0·93, 0·99) and 2 % (0·98; 0·96, 0·99) lower odds of central obesity, respectively. However, a higher total proteins score was associated with higher odds of central obesity (1·08; 1·00, 1·16). In gender-specific analyses, a higher whole fruit or sodium score was inversely associated with central obesity in men but not in women. HEI-2010 scores of total fruit and sodium were inversely associated with central obesity among all Mexican Americans. However, total proteins score and central obesity was positively associated. In Mexican-American men, HEI-2010 total and whole fruit scores were inversely associated with central obesity.

  14. Pre-experience Perceptions About Telemedicine Among African Americans and Latinos in South Central Los Angeles

    PubMed Central

    Hamilton, Alison; Baker, Richard

    2009-01-01

    Abstract This study explores perceptions about telemedicine among urban underserved African American and Latino populations. Telemedicine has been advanced as a vehicle to increase access to specialty care among the urban underserved, yet little is known about its acceptability among these populations. We conducted 10 focus groups with African American and Latino participants (n = 87) in urban Los Angeles in order to explore perceptions about this novel type of care. We found that concerns about telemedicine varied between the two racial/ethnic groups. These findings have implications for important issues such as adoption of telemedicine, patient satisfaction, and doctor–patient interaction. It will be critical to consider perceptions of this healthcare innovation in the development of strategies to market and implement telemedicine among urban, underserved African American and Latino populations. PMID:19566397

  15. Dark Agouti rat model of chemotherapy-induced mucositis: Establishment and current state of the art

    PubMed Central

    Vanhoecke, Barbara; Bateman, Emma; Mayo, Bronwen; Vanlancker, Eline; Thorpe, Daniel; Keefe, Dorothy

    2015-01-01

    Mucositis is a major oncological problem. The entire gastrointestinal and genitourinary tract and also other mucosal surfaces can be affected in recipients of radiotherapy, and/or chemotherapy. Major progress has been made in recent years in understanding the mechanisms of oral and small intestinal mucositis, which appears to be more prominent than colonic damage. This progress is largely due to the development of representative laboratory animal models of mucositis. This review focuses on the development and establishment of the Dark Agouti rat mammary adenocarcinoma model by the Mucositis Research Group of the University of Adelaide over the past 20 years to characterize the mechanisms underlying methotrexate-, 5-fluorouracil-, and irinotecan-induced mucositis. It also aims to summarize the results from studies using different animal model systems to identify new molecular and cellular markers of mucositis. PMID:25966981

  16. [Participation of Agouti related peptide in machanisms of wakefulness-sleep cycle regulation].

    PubMed

    Romanova, I V; Mikhrina, A L

    2013-01-01

    Agouti-related protein (AGRP) is expresses in hypothalamic neurons in human and animals. Immunohistochemical study in rats Wistar rats demonstrates significant changes AGRP optical density in the neurons of arcuate hypothalamic nucleus as well as in processes in the hypothalamus and nucleus accumbens after the 6 hours of sleep deprivation (increase) and after 2 hours of post-deprivative sleep (decrease). Comparison of these results with earlier obtained shows the opposite trend changes in AGRP optical density and speed limiting enzyme of dopamine synthesis-tyrosine hydroxylase in the hypothalamus and in striatonigral system. The increase of AGRP was accompanied by a decrease of tyrosine hydroxylase and the decrease of AGRP, apposite, it increases. The obtained data demonstrate the role ofAGRP as a modulator of the functional activity of the dopaminergic brain neurons. The problem of the relationship of various functions of organism (food behavior, sleep, stress) is discusses by their participation in the regulation of the same neurotransmitter systems.

  17. Dark Agouti rat model of chemotherapy-induced mucositis: establishment and current state of the art.

    PubMed

    Vanhoecke, Barbara; Bateman, Emma; Mayo, Bronwen; Vanlancker, Eline; Stringer, Andrea; Thorpe, Daniel; Keefe, Dorothy

    2015-06-01

    Mucositis is a major oncological problem. The entire gastrointestinal and genitourinary tract and also other mucosal surfaces can be affected in recipients of radiotherapy, and/or chemotherapy. Major progress has been made in recent years in understanding the mechanisms of oral and small intestinal mucositis, which appears to be more prominent than colonic damage. This progress is largely due to the development of representative laboratory animal models of mucositis. This review focuses on the development and establishment of the Dark Agouti rat mammary adenocarcinoma model by the Mucositis Research Group of the University of Adelaide over the past 20 years to characterize the mechanisms underlying methotrexate-, 5-fluorouracil-, and irinotecan-induced mucositis. It also aims to summarize the results from studies using different animal model systems to identify new molecular and cellular markers of mucositis.

  18. Making African American Culture and History Central to Early Childhood Teaching and Learning

    ERIC Educational Resources Information Center

    Boutte, Gloria Swindler; Strickland, Jennifer

    2008-01-01

    This article provides a conceptualization for including African and African American history in early childhood classrooms. An example of a kindergarten teacher's efforts to counter negative depictions and frequently omitted information in her classroom is shared. While many early childhood educators avoid discussions of history because the…

  19. Educational Equity Policies and the Centralization of American Public Education: The Case of Bilingual Education

    ERIC Educational Resources Information Center

    Mavrogordato, Madeline

    2012-01-01

    Sixty years ago, federal guidelines regarding the instruction of special populations in American public schools were nonexistent. Racial minorities, language minorities, women, the poor, and those with physical and mental disabilities had not been identified as groups that needed special protections. Much has changed since then. Federal…

  20. Academic Race Stereotypes, Academic Self-Concept, and Racial Centrality in African American Youth

    ERIC Educational Resources Information Center

    Okeke, Ndidi A.; Howard, Lionel C.; Kurtz-Costes, Beth; Rowley, Stephanie J.

    2009-01-01

    The relation between academic race stereotype endorsement and academic self-concept was examined in two studies of seventh- and eighth-grade African Americans. Based on expectancy-value theory, the authors hypothesized that academic race stereotype endorsement would be negatively related to self-perceptions. Furthermore, it was anticipated that…

  1. Political Participation and Social Capital among Mexicans and Mexican Americans in Central Illinois

    ERIC Educational Resources Information Center

    Albarracin, Julia; Valeva, Anna

    2011-01-01

    This study tested the influence of bridging and bonding social capital in political participation while controlling for sociodemographic and psychological factors among Mexicans and Mexican Americans in Illinois. Bridging social capital significantly predicted two types of participation. Participants who felt their lives were linked to those of…

  2. Making African American Culture and History Central to Early Childhood Teaching and Learning

    ERIC Educational Resources Information Center

    Boutte, Gloria Swindler; Strickland, Jennifer

    2008-01-01

    This article provides a conceptualization for including African and African American history in early childhood classrooms. An example of a kindergarten teacher's efforts to counter negative depictions and frequently omitted information in her classroom is shared. While many early childhood educators avoid discussions of history because the…

  3. Educational Equity Policies and the Centralization of American Public Education: The Case of Bilingual Education

    ERIC Educational Resources Information Center

    Mavrogordato, Madeline

    2012-01-01

    Sixty years ago, federal guidelines regarding the instruction of special populations in American public schools were nonexistent. Racial minorities, language minorities, women, the poor, and those with physical and mental disabilities had not been identified as groups that needed special protections. Much has changed since then. Federal…

  4. University of Central Florida and the American Association of State Colleges and Universities: Blended Learning Toolkit

    ERIC Educational Resources Information Center

    EDUCAUSE, 2014

    2014-01-01

    The Blended Learning Toolkit supports the course redesign approach, and interest in its openly available clearinghouse of online tools, strategies, curricula, and other materials to support the adoption of blended learning continues to grow. When the resource originally launched in July 2011, 20 AASCU [American Association of State Colleges and…

  5. Training lay volunteers to promote health in central-city African American churches.

    PubMed

    Ellis, Julie L; Morzinski, Jeffrey A

    2013-01-01

    In a nation plagued by skyrocketing healthcare costs, is there an affordable way to address health needs of older African Americans in medically underserved areas? The Milwaukee, Wisconsin's Elder Community Health Upholder (ECHU) project indicates yes, we can. The key: A partnership that guides committed volunteers focused on establishing and sustaining health initiatives in faith-based settings.

  6. University of Central Florida and the American Association of State Colleges and Universities: Blended Learning Toolkit

    ERIC Educational Resources Information Center

    EDUCAUSE, 2014

    2014-01-01

    The Blended Learning Toolkit supports the course redesign approach, and interest in its openly available clearinghouse of online tools, strategies, curricula, and other materials to support the adoption of blended learning continues to grow. When the resource originally launched in July 2011, 20 AASCU [American Association of State Colleges and…

  7. The Great American Biotic Interchange in frogs: multiple and early colonization of Central America by the South American genus Pristimantis (Anura: Craugastoridae).

    PubMed

    Pinto-Sánchez, Nelsy Rocío; Ibáñez, Roberto; Madriñán, Santiago; Sanjur, Oris I; Bermingham, Eldredge; Crawford, Andrew J

    2012-03-01

    The completion of the land bridge between North and South America approximately 3.5-3.1 million years ago (Ma) initiated a tremendous biogeographic event called the Great American Biotic Interchange (GABI), described principally from the mammalian fossil record. The history of biotic interchange between continents for taxonomic groups with poor fossil records, however, is not well understood. Molecular and fossil data suggest that a number of plant and animal lineages crossed the Isthmus of Panama well before 3.5 Ma, leading biologists to speculate about trans-oceanic dispersal mechanisms. Here we present a molecular phylogenetic analysis of the frog genus Pristimantis based on 189 individuals of 137 species, including 71 individuals of 31 species from Panama and Colombia. DNA sequence data were obtained from three mitochondrial (COI, 12S, 16S) and two nuclear (RAG-1 and Tyr) genes, for a total of 4074 base pairs. The resulting phylogenetic hypothesis showed statistically significant conflict with most recognized taxonomic groups within Pristimantis, supporting only the rubicundus Species Series, and the Pristimantis myersi and Pristimantis pardalis Species Groups as monophyletic. Inference of ancestral areas based on a likelihood model of geographic range evolution via dispersal, local extinction, and cladogenesis (DEC) suggested that the colonization of Central America by South American Pristimantis involved at least 11 independent events. Relaxed-clock analyses of divergence times suggested that at least eight of these invasions into Central America took place prior to 4 Ma, mainly in the Miocene. These findings contribute to a growing list of molecular-based biogeographic studies presenting apparent temporal conflicts with the traditional GABI model.

  8. Informal employment, unpaid care work, and health status in Spanish-speaking Central American countries: a gender-based approach.

    PubMed

    Lopez-Ruiz, María; Benavides, Fernando G; Vives, Alejandra; Artazcoz, Lucía

    2017-03-01

    To assess the relationship between paid work, family characteristics and health status in Central American workers; and to examine whether patterns of association differ by gender and informal or formal employment. Cross-sectional study of 8680 non-agricultural workers, based on the First Central American Survey of Working Conditions and Health (2011). Main explicative variables were paid working hours, marital status, caring for children, and caring for people with functional diversity or ill. Using Poisson regression models, adjusted prevalence ratios of poor self-perceived and mental health were calculated by sex and social security coverage (proxy of informal employment). A clear pattern of association was observed for women in informal employment who were previously married, had care responsibilities, long working hours, or part-time work for both self-perceived and mental health. No other patterns were found. Our results show health inequalities related to unpaid care work and paid work that depend on the interaction between gender and informal employment. To reduce these inequalities suitable policies should consider both the labor (increasing social security coverage) and domestic spheres (co-responsibility of care).

  9. Cenozoic History of Paleo-Currents through the Central American Seaway: Insights from Deep Sea Sediments and Outcrops in Panama

    NASA Astrophysics Data System (ADS)

    Waite, A. J.; Martin, E. E.

    2015-12-01

    Paleontologic, oceanographic, and ecologic studies suggest gradual shoaling of the Central American Seaway between ~15 to 2 Ma that caused a stepwise shutdown of deep, intermediate, and shallow water exchange between the Pacific Ocean and Caribbean Sea. This diminishing communication has been further associated with changes in surface and deep ocean currents, atmospheric flow, and ultimately regional and global climate. Recent studies of the Isthmus of Panama's exhumation history, palm phylogenies, and fossil/molecularly derived migration rates, however, suggest that the isthmus may have risen much earlier. An earlier rise scenario would call into question many accepted consequences of this gateway event under the 'Panama Hypothesis,' including strengthened thermohaline circulation, North Atlantic Deep Water production, the onset of Northern Hemisphere glaciation, and the Great American Biotic Interchange. Despite considerable research on the Neogene, few paleoceanographic studies have directly examined long-term changes in the adjacent oceans over the Cenozoic to evaluate the potential for earlier events in the closure history of the seaway. In this study, we extend records of bottom water circulation reconstructed from the Nd-isotopes of fish teeth from several Caribbean International Ocean Discovery Program sediment cores (ODP Sites 998, 999, 1000). These reconstructions clearly depict an increase in Pacific volcanism throughout the Cenozoic and sustained transport of Pacific waters into the Caribbean basin from ~50 to 9 Ma, although there appear to be interesting complexities within the Caribbean basin itself. We also present preliminary investigations into the potential of Nd-isotopic analyses on fossil fish teeth recovered from outcrops and exposures of marine strata across Panama to further elucidate the regional dynamics and shoaling history of the Central American Seaway.

  10. Caribbean and Central American Women's Feminist Inquiry through Theater-Based Action Research

    ERIC Educational Resources Information Center

    Sánchez Ares, Rocío

    2015-01-01

    Feminist action research interrogates gendered dynamics in the development of a collective consciousness. A group of immigrant Latina women (Latinas) from the Caribbean and Central America employed community-based theater as an instrument to mobilize diverse audiences against discriminatory practices and policies. Based on their theater work, I…

  11. Visibly Hidden: Language, Culture and Identity of Central Americans in Los Angeles

    ERIC Educational Resources Information Center

    Lavadenz, Magaly

    2008-01-01

    The history, culture and practices of Central America are inadequately addressed in teacher preparation and professional development across the United States, and especially in California based on the author's analysis of teacher preparation. Information about the histories, cultures and practices add to the linguistic and pedagogic knowledge-base…

  12. Corporate Liberalism, Finance Hegemony, and Central State Intervention in the Reconstruction of American Higher Education.

    ERIC Educational Resources Information Center

    Barrow, Clyde W.

    This paper suggests that contemporary educational historians have failed to appreciate the extent to which the institutional response to industrialism was actively induced by the financial hegemony of the new corporate elite and simultaneously advanced by the emerging authority of the central state. Further, it argues that progressive era higher…

  13. Visibly Hidden: Language, Culture and Identity of Central Americans in Los Angeles

    ERIC Educational Resources Information Center

    Lavadenz, Magaly

    2008-01-01

    The history, culture and practices of Central America are inadequately addressed in teacher preparation and professional development across the United States, and especially in California based on the author's analysis of teacher preparation. Information about the histories, cultures and practices add to the linguistic and pedagogic knowledge-base…

  14. Caribbean and Central American Women's Feminist Inquiry through Theater-Based Action Research

    ERIC Educational Resources Information Center

    Sánchez Ares, Rocío

    2015-01-01

    Feminist action research interrogates gendered dynamics in the development of a collective consciousness. A group of immigrant Latina women (Latinas) from the Caribbean and Central America employed community-based theater as an instrument to mobilize diverse audiences against discriminatory practices and policies. Based on their theater work, I…

  15. Demonstrating appropriate silviculture for sustainable forestry in central Siberia: a Russian - American partnership

    Treesearch

    J. C. Brissette; S. T. Eubanks; A. J. R. Gillespie; R. J. Lasko; A. V. Rykoff

    1997-01-01

    A joint Northeastern Forest Experiment Station - Eastern Region team is working with Russian counterparts on a Forests for the Future Initiative in the Krasnoyarsk region of central Siberia. Russian team members include scientists from the Sukachev Institute of the Russian Academy of Sciences, managers from a number of units of the Federal Forest Service of Russia, and...

  16. Mutations in BRCA1, BRCA2 and other breast and ovarian cancer susceptibility genes in Central and South American populations.

    PubMed

    Jara, Lilian; Morales, Sebastian; de Mayo, Tomas; Gonzalez-Hormazabal, Patricio; Carrasco, Valentina; Godoy, Raul

    2017-10-06

    Breast cancer (BC) is the most common malignancy among women worldwide. A major advance in the understanding of the genetic etiology of BC was the discovery of BRCA1 and BRCA2 (BRCA1/2) genes, which are considered high-penetrance BC genes. In non-carriers of BRCA1/2 mutations, disease susceptibility may be explained of a small number of mutations in BRCA1/2 and a much higher proportion of mutations in ethnicity-specific moderate- and/or low-penetrance genes. In Central and South American populations, studied have focused on analyzing the distribution and prevalence of BRCA1/2 mutations and other susceptibility genes that are scarce in Latin America as compared to North America, Europe, Australia, and Israel. Thus, the aim of this review is to present the current state of knowledge regarding pathogenic BRCA variants and other BC susceptibility genes. We conducted a comprehensive review of 47 studies from 12 countries in Central and South America published between 2002 and 2017 reporting the prevalence and/or spectrum of mutations and pathogenic variants in BRCA1/2 and other BC susceptibility genes. The studies on BRCA1/2 mutations screened a total of 5956 individuals, and studies on susceptibility genes analyzed a combined sample size of 11,578 individuals. To date, a total of 190 different BRCA1/2 pathogenic mutations in Central and South American populations have been reported in the literature. Pathogenic mutations or variants that increase BC risk have been reported in the following genes or genomic regions: ATM, BARD1, CHECK2, FGFR2, GSTM1, MAP3K1, MTHFR, PALB2, RAD51, TOX3, TP53, XRCC1, and 2q35.

  17. Cerebrospinal Fluid Levels of Leptin, Proopiomelanocortin, and Agouti-Related Protein in Human Pregnancy: Evidence for Leptin Resistance

    PubMed Central

    Page-Wilson, Gabrielle; Reitman-Ivashkov, Elena; Meece, Kana; White, Anne; Rosenbaum, Michael; Smiley, Richard M.

    2013-01-01

    Context: Leptin suppresses appetite by modulating the expression of hypothalamic neuropeptides including proopiomelanocortin (POMC) and agouti-related peptide (AgRP). Yet during pregnancy, caloric consumption increases despite elevated plasma leptin levels. Design and Participants: To investigate this paradox, we measured leptin and soluble leptin receptor in plasma and leptin, POMC, and AgRP in cerebrospinal fluid (CSF) from 21 fasting pregnant women before delivery by cesarean section at a university hospital and from 14 fasting nonpregnant women. Results: Prepregnancy body mass index was 24.6 ± 1.1 (se) vs. 31.3 ± 1.3 at term vs. 26.5 ± 1.6 kg/m2 in controls. Plasma leptin (32.9 ± 4.6 vs. 16.7 ± 3.0 ng/ml) and soluble leptin receptor (30.9 ± 2.3 vs. 22.1 ± 1.4 ng/ml) levels were significantly higher in pregnant women. However, mean CSF leptin did not differ between the two groups (283 ± 34 vs. 311 ± 32 pg/ml), consistent with a relative decrease in leptin transport into CSF during pregnancy. Accordingly, the CSF/plasma leptin percentage was 1.0 ± 0.01% in pregnant subjects vs. 2.1 ± 0.2% in controls (P < 0.0001). Mean CSF AgRP was significantly higher in pregnant subjects (32.3 ± 2.7 vs. 23.5 ± 2.5 pg/ml; P = 0.03). Mean CSF POMC was not significantly different in pregnant subjects (200 ± 13.6 vs. 229 ± 17.3 fmol/ml; P = 0.190). However, the mean AgRP/POMC ratio was significantly higher among pregnant women (P = 0.003), consistent with an overall decrease in melanocortin tone favoring increased food intake during pregnancy. Conclusions: These data demonstrate that despite peripheral hyperleptinemia, positive energy balance is achieved during pregnancy by a relative decrease in central leptin concentrations and resistance to leptin's effects on target neuropeptides that regulate energy balance. PMID:23118421

  18. The high glycemic index diet was an independent predictor to explain changes in agouti-related protein in obese adolescents.

    PubMed

    Dal Molin Netto, Bárbara; Landi Masquio, Deborah Cristina; Da Silveira Campos, Raquel Munhoz; De Lima Sanches, Priscila; Campos Corgosinho, Flavia; Tock, Lian; Missae Oyama, Lila; Túlio de Mello, Marco; Tufik, Sergio; Dâmaso, Ana Raimunda

    2014-02-01

    La Dieta de alto índice glucémico es un predictor independiente para explicar los cambios en la proteína relacionada al agouti en adolescentes obesos. Introducción y objetivos: El papel de la dieta de índice glucémico (GI) en el control de los factores orexigénicos y anorexígenos del balance de energía todavía no está claro. El presente estudio tuvo como objetivo evaluar si la dieta habitual, de acuerdo con diferentes alimentos con IG, ejerce influencia sobre la regulación de los marcadores del balance de energía y los efectos de la intervención interdisciplinaria en adolescentes obesos. Métodos: Un total de 55 adolescentes obesos, con edades de 14 a 19 años, han sido sometidos a un año de tratamiento interdisciplinario y se dividieron en dos grupos, de acuerdo al patrón de dieta predominante de la ingesta de alimentos: el grupo IG alto (H-GI; n = 29) y GI moderada/bajo grupo (M/L-GI, n = 26). Resultados: La concentración de orexigenic factor de AgRP (p < 0,01), la grasa visceral (p = 0,04) y la relación visceral/ subcutánea (p = 0,03) fueron mayores en el grupo de HGI en comparación con el grupo M/L-GI. Por otra parte, el consumo habitual de alimentos H-GI fue un predictor independiente para explicar los cambios en las concentraciones de AgRP. Después de un año de tratamiento interdisciplinario, los adolescentes presentan una reducción significativa en el peso corporal, la grasa corporal total (%), visceral y la grasa subcutánea y el HOMA-IR, así como un aumento significativo de la masa libre de grasa (%). Conclusiones: Nuestros resultados pueden sugerir que la dieta H-GI habitual podría upregulate vías orexigénicos, contribuyendo al círculo vicioso entre las dietas indeseables, desregula el equilibrio energético y predisponen a la obesidad. Uno por otro lado, un año de tratamiento interdisciplinario puede perfil metabólico mejora significativa y la obesidad central en los adolescentes.

  19. Central American biomass burning smoke can increase tornado severity in the U.S.

    NASA Astrophysics Data System (ADS)

    Saide, P. E.; Spak, S. N.; Pierce, R. B.; Otkin, J. A.; Schaack, T. K.; Heidinger, A. K.; Silva, A. M.; Kacenelenbogen, M.; Redemann, J.; Carmichael, G. R.

    2015-02-01

    Tornadoes in the Southeast and central U.S. are episodically accompanied by smoke from biomass burning in central America. Analysis of the 27 April 2011 historical tornado outbreak shows that adding smoke to an environment already conducive to severe thunderstorm development can increase the likelihood of significant tornado occurrence. Numerical experiments indicate that the presence of smoke during this event leads to optical thickening of shallow clouds while soot within the smoke enhances the capping inversion through radiation absorption. The smoke effects are consistent with measurements of clouds and radiation before and during the outbreak. These effects result in lower cloud bases and stronger low-level wind shear in the warm sector of the extratropical cyclone generating the outbreak, two indicators of higher probability of tornadogenesis and tornado intensity and longevity. These mechanisms may contribute to tornado modulation by aerosols, highlighting the need to consider aerosol feedbacks in numerical severe weather forecasting.

  20. Functional anatomy of the female genital organs of the wild black agouti (Dasyprocta fuliginosa) female in the Peruvian Amazon.

    PubMed

    Mayor, P; Bodmer, R E; Lopez-Bejar, M

    2011-02-01

    This study examined anatomical and histological characteristics of genital organs of 38 black agouti females in the wild in different reproductive stages, collected by rural hunters in the North-eastern Peruvian Amazon. Females in the follicular phase of the estrous cycle had greater antral follicle sizes than other females, the largest antral follicle measuring 2.34mm. Antral follicles in pregnant females and females in luteal phase of the estrous cycle had an average maximum diameter smaller than 1mm. In black agouti females in follicular phase, some antral follicles are selected to continue to growth, reaching a pre-ovulatory diameter of 2mm. Mean ovulation rate was 2.5 follicles and litter size was 2.1 embryos or fetuses per pregnant female, resulting in a rate of ovum mortality of 20.8%. Many follicles from which ovulation did not occur of 1-mm maximum diameter luteinize forming accessory CL. The constituent active luteal tissues of the ovary are functional and accessory CL. Although all females had accessory CL, transformation of follicles into accessory CL occurred especially in pregnant females, resulting in a contribution from 9% to 23% of the total luteal volume as pregnancy advances. The persistence of functional CL throughout pregnancy might reflect the importance for the maintenance of gestation and may be essential for the continuous hormonal production. The duplex uterus of the agouti female is composed by two completely independent uterine horns with correspondent separate cervices opening into the vagina. In pregnant females, most remarkable observed uterine adaptations were induced by the progressive enlargement caused by the normal pregnancy evolution. The wild black agouti showed different vaginal epithelium features in accordance with the reproductive state of the female. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Pregnancy in Hystricomorpha: gestational age and embryonic-fetal development of agouti (Dasyprocta prymnolopha, Wagler 1831) estimated by ultrasonography.

    PubMed

    Sousa, F C A; Alves, F R; Fortes, E A M; Ferraz, M S; Machado Júnior, A A N; de Menezes, D J A; de Carvalho, M A M

    2012-10-01

    Thirty-one pregnant agoutis, between Days 9 and 103 of gestation (Day 1 = day of detection of sperm in the vaginal smear), underwent B-mode ultrasonography; gestational sac diameter (GSD), crown-rump length (CRL), embryonic-fetal diameter (EFD), and placenta diameter (PD) were measured. There were positive correlations (P < 0.05) between GSD and CRL (r = 0.98), GSD and PD (r = 0.88), CRL and PD (r = 0.86), days of gestation (DG) and CRL (r = 0.85), and DG and PD (r = 0.73). The gestational sac was first observed on Day 14. The embryo was first seen on Day 18 in 9/31 of pregnant agoutis and on Day 22 in 20/31 of pregnant agoutis. Heartbeats were detected from the Day 25 and placentas were observed in 100% of the animals from Day 25. Early limb bud and ossification of the fetal skull were identified on Days 27 (15/31) and 45 (24/31), respectively. Fetal orientation (head and body) was evident from Day 40, the stomach, liver and lungs were identified on Day 50, the kidneys were reliably seen only on Day 55, and the aorta and vena cava were seen on Day 70. The fetal bowel and the urinary bladder were the last structures to be observed (Day 85). Ultrasonography was effective for early pregnancy diagnosis in agouti and for obtaining information on embryonic and fetal structures that could be used to predict gestational age and birth, thereby contributing to their reproductive management in captivity.

  2. Major Caribbean and Central American frog faunas originated by ancient oceanic dispersal

    PubMed Central

    Heinicke, Matthew P.; Duellman, William E.; Hedges, S. Blair

    2007-01-01

    Approximately one-half of all species of amphibians occur in the New World tropics, which includes South America, Middle America, and the West Indies. Of those, 27% (801 species) belong to a large assemblage, the eleutherodactyline frogs, which breed out of water and lay eggs that undergo direct development on land. Their wide distribution and mode of reproduction offer potential for resolving questions in evolution, ecology, and conservation. However, progress in all of these fields has been hindered by a poor understanding of their evolutionary relationships. As a result, most of the species have been placed in a single genus, Eleutherodactylus, which is the largest among vertebrates. Our DNA sequence analysis of a major fraction of eleutherodactyline diversity revealed three large radiations of species with unexpected geographic isolation: a South American Clade (393 sp.), a Caribbean Clade (171 sp.), and a Middle American Clade (111 sp.). Molecular clock analyses reject the prevailing hypothesis that these frogs arose from land connections with North and South America and their subsequent fragmentation in the Late Cretaceous (80–70 Mya). Origin by dispersal, probably over water from South America in the early Cenozoic (47–29 million years ago, Mya), is more likely. PMID:17548823

  3. Recovery and cryopreservation of epididymal sperm from agouti (Dasiprocta aguti) using powdered coconut water (ACP-109c) and Tris extenders.

    PubMed

    Silva, M A; Peixoto, G C X; Santos, E A A; Castelo, T S; Oliveira, M F; Silva, A R

    2011-10-01

    The objective was to compare the use of powdered coconut water (ACP-109c; ACP Biotecnologia, Fortaleza, CE, Brazil) and Tris extenders for recovery and cryopreservation of epididymal sperm from agouti. The caudae epididymus and proximal ductus deferens from 10 sexually mature agoutis were subjected to retrograde washing using ACP-109c (ACP Biotecnologia) or Tris. Epididymal sperm were evaluated for motility, vigor, sperm viability, membrane integrity, and morphology. Samples were centrifuged, and extended in the same diluents plus egg yolk (20%) and glycerol (6%), frozen in liquid nitrogen, and subsequently thawed at 37°C for 1 min, followed by re-evaluation of sperm characteristics. The two extenders were similarly efficient for epididymal recovery, with regard to the number and quality of sperm recovered. However, for both extenders, sperm quality decreased (P < 0.05) after centrifugation and dilution. After sperm cryopreservation and thawing, there were (mean ± SEM) 26.5 ± 2.6% motile sperm with 2.6 ± 0.2 vigor in the ACP-109c (ACP Biotecnologia) group, which was significantly better than 9.7 ± 2.6% motile sperm with 1.2 ± 0.3 vigor in Tris. In conclusion, agouti epididymal sperm were successfully recovered using either ACP-109c (ACP Biotecnologia) or Tris extenders; however, ACP-109c (ACP Biotecnologia) was a significantly better extender for processing and cryopreserving these sperm. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Deletion of eIF2beta suppresses testicular cancer incidence and causes recessive lethality in agouti-yellow mice.

    PubMed

    Heaney, Jason D; Michelson, Megan V; Youngren, Kirsten K; Lam, Man-Yee J; Nadeau, Joseph H

    2009-04-15

    The agouti-yellow (A(y)) deletion is the only genetic modifier known to suppress testicular germ cell tumor (TGCT) susceptibility in mice or humans. The A(y) mutation deletes Raly and Eif2s2, and induces the ectopic expression of agouti, all of which are potential TGCT-modifying mutations. Here we report that the reduced TGCT incidence of heterozygous A(y) males and the recessive embryonic lethality of A(y) are caused by the deletion of Eif2s2, the beta subunit of translation initiation factor eIF2. We found that the incidence of affected males was reduced 2-fold in mice that were partially deficient for Eif2s2 and that embryonic lethality occurred near the time of implantation in mice that were fully deficient for Eif2s2. In contrast, neither reduced expression of Raly in gene-trap mice nor ectopic expression of agouti in transgenic or viable-yellow (A(vy)) mutants affected TGCT incidence or embryonic viability. In addition, we provide evidence that partial deficiency of Eif2s2 attenuated germ cell proliferation and differentiation, both of which are important to TGCT formation. These results show that germ cell development and TGCT pathogenesis are sensitive to the availability of the eIF2 translation initiation complex and to changes in the rate of translation.

  5. U-series disequilibria in Guatemalan lavas, crustal contamination, and implications for magma genesis along the Central American subduction zone

    NASA Astrophysics Data System (ADS)

    Walker, James A.; Mickelson, J. Erik; Thomas, Rebecca B.; Patino, Lina C.; Cameron, Barry; Carr, Michael J.; Feigenson, Mark D.; Edwards, R. Lawrence

    2007-06-01

    New U-series results indicate that Guatemalan volcanic rocks display both 238U and 230Th excesses. 230Th excess is restricted to volcanoes in central Guatemala, both along and behind the front. 230Th excess correlates with a number of incompatible element ratios, such as Th/Nb and Ba/Th. It also shows a negative correlation with MgO. Guatemalan volcanic rocks have (230Th/232Th) ratios that overlap those of Costa Rican volcanics and are therefore considerably lower than the unusually high ratios characterizing volcanic rocks from Nicaragua. Along-arc variations in (230Th/232Th) therefore mirror those of a number of diagnostic geochemical parameters, such as Ba/La, which are symmetrical about a peak in west central Nicaragua. The one siliceous lava analyzed, from the Cerro Quemado dome complex, has a recognizable crustal imprint, distinguished, for instance, by high Th/Nb and low Ba/Th. In mafic samples, 238U excess is attributed to addition of a U-enriched fluid component from the subducting Cocos plate. Our preferred explanation for 230Th excess in Guatemalan mafic samples, on the other hand, is crustal contamination, consistent with the relatively high Th/Nb and low Ba/Th ratios in these samples. We suspect, however, that crustal contamination only exerts a sizable control over the U-series disequilibrium of mafic magmas in Guatemala, and not elsewhere along the Central American volcanic front. This agrees with previously published trace element and isotopic evidence that throughout Central America, with the exception of Guatemala, mafic magmas are largely uncontaminated by crustal material.

  6. Spatial Ecology of the American Crocodile in a Tropical Pacific Island in Central America.

    PubMed

    Balaguera-Reina, Sergio A; Venegas-Anaya, Miryam; Sánchez, Andrés; Arbelaez, Italo; Lessios, Harilaos A; Densmore, Llewellyn D

    2016-01-01

    Conservation of large predators has long been a challenge for biologists due to the limited information we have about their ecology, generally low numbers in the wild, large home ranges and the continuous expansion of human settlements. The American crocodile (Crocodylus acutus) is a typical apex predator, that has suffered from all of these characteristic problems, especially the latter one. Humans have had a major impact on the recovery of this species throughout its range, even though most of the countries it inhabits have banned hunting. The last decade has made it clear that in order to implement sound conservation and management programs, we must increase our understanding of crocodile spatial ecology. However, in only two countries where American crocodiles have telemetry studies even been published. Herein we have characterized the spatial ecology of C. acutus on Coiba Island, Panama, by radio-tracking (VHF transmitters) 24 individuals between 2010 and 2013, to determine movement patterns, home range, and habitat use. We have then compared our findings with those of previous studies to develop the most comprehensive assessment of American crocodile spatial ecology to date. Females showed a higher average movement distance (AMD) than males; similarly, adults showed a higher AMD than sub-adults and juveniles. However, males exhibited larger home ranges than females, and concomitantly sub-adults had larger home ranges than juveniles, hatchlings, and adults. There was an obvious relationship between seasonal precipitation and AMD, with increased AMD in the dry and "low-wet" seasons, and reduced AMD during the "true" wet season. We found disaggregate distributions according to age groups throughout the 9 habitat types in the study area; adults and hatchlings inhabited fewer habitat types than juveniles and sub-adults. These sex- and age-group discrepancies in movement and habitat choice are likely due to the influences of reproductive biology and Coiba

  7. Spatial Ecology of the American Crocodile in a Tropical Pacific Island in Central America

    PubMed Central

    Balaguera-Reina, Sergio A.; Venegas-Anaya, Miryam; Sánchez, Andrés; Arbelaez, Italo; Lessios, Harilaos A.; Densmore, Llewellyn D.

    2016-01-01

    Conservation of large predators has long been a challenge for biologists due to the limited information we have about their ecology, generally low numbers in the wild, large home ranges and the continuous expansion of human settlements. The American crocodile (Crocodylus acutus) is a typical apex predator, that has suffered from all of these characteristic problems, especially the latter one. Humans have had a major impact on the recovery of this species throughout its range, even though most of the countries it inhabits have banned hunting. The last decade has made it clear that in order to implement sound conservation and management programs, we must increase our understanding of crocodile spatial ecology. However, in only two countries where American crocodiles have telemetry studies even been published. Herein we have characterized the spatial ecology of C. acutus on Coiba Island, Panama, by radio-tracking (VHF transmitters) 24 individuals between 2010 and 2013, to determine movement patterns, home range, and habitat use. We have then compared our findings with those of previous studies to develop the most comprehensive assessment of American crocodile spatial ecology to date. Females showed a higher average movement distance (AMD) than males; similarly, adults showed a higher AMD than sub-adults and juveniles. However, males exhibited larger home ranges than females, and concomitantly sub-adults had larger home ranges than juveniles, hatchlings, and adults. There was an obvious relationship between seasonal precipitation and AMD, with increased AMD in the dry and “low-wet” seasons, and reduced AMD during the “true” wet season. We found disaggregate distributions according to age groups throughout the 9 habitat types in the study area; adults and hatchlings inhabited fewer habitat types than juveniles and sub-adults. These sex- and age-group discrepancies in movement and habitat choice are likely due to the influences of reproductive biology and Coiba

  8. Psychosocial Factors and Preterm Birth Among African American and White Women in Central North Carolina

    PubMed Central

    Dole, Nancy; Savitz, David A.; Siega-Riz, Anna Maria; Hertz-Picciotto, Irva; McMahon, Michael J.; Buekens, Pierre

    2004-01-01

    Objectives. We assessed associations between psychosocial factors and preterm birth, stratified by race in a prospective cohort study. Methods. We surveyed 1898 women who used university and public health prenatal clinics regarding various psychosocial factors. Results. African Americans were at higher risk of preterm birth if they used distancing from problems as a coping mechanism or reported racial discrimination. Whites were at higher risk if they had high counts of negative life events or were not living with a partner. The association of pregnancy-related anxiety with preterm birth weakened when medical comorbidities were taken into account. No association with preterm birth was found for depression, general social support, or church attendance. Conclusions. Some associations between psychosocial variables and preterm birth differed by race. PMID:15284044

  9. Mineralization potential along the trend of the Keweenawan- age Central North American Rift System in Iowa, Nebraska, and Kansas

    USGS Publications Warehouse

    Berendsen, P.

    1989-01-01

    The tectonic and sedimentary environment of the Central North American Rift System (CNARS) provides an excellent setting for major mineral deposits. Major north-northeast-trending high-angle normal or reverse faults and northwest-trending transcurrent fault systems may exercise control over ore forming processes. Gabbro and basalt are the dominant igneous rock types. Carbonatite and kimberlite occur in Nebraska and Kansas. Concentrations of Cu, Ni, Co, Ti, Au, Ag and PG minerals are known to occur in this setting. Arkosic sandstone, siltstone, shale, and minor carbonate units occur on top of the rift basalts and in flanking basins where they may reach thicknesses of 10 km (6 miles). The potential for stratiform or unconformity-related metalliferous deposits should be considered. The rift as a whole remains largely unexplored.

  10. Hematology and serum biochemistry comparison in wild and captive Central American river turtles (Dermatemys mawii) in Tabasco, Mexico.

    PubMed

    Rangel-Mendoza, Judith; Weber, Manuel; Zenteno-Ruiz, Claudia E; López-Luna, Marco A; Barba-Macías, Everardo

    2009-10-01

    Hematological and serum biochemistry analyses were determined on 51 Central American river turtles (Dermatemys mawii) during the dry and rainy seasons of 2006. Turtles came from two sites: Pantanos de Centla Biosphere Reserve and a turtle breeding farm, both located in Tabasco State, Mexico. Physical examination and body measures of animals were performed. Incidence and prevalence of hemoparasites were explored. Captive organisms were in poor physical condition while wild turtles were apparently healthy. There were differences in several hematological parameters related with the condition and the season. During the dry season captive turtles exhibited higher levels of uric acid and urea, as well as lower levels of glucose. Haemogregarina sp. was detected in 100% of the wild individuals, but not in captive individuals. Its incidence was greater during the rainy season. This is the first health assessment and hematology study of this critically endangered species.

  11. Current and future niche of North and Central American sand flies (Diptera: psychodidae) in climate change scenarios.

    PubMed

    Moo-Llanes, David; Ibarra-Cerdeña, Carlos N; Rebollar-Téllez, Eduardo A; Ibáñez-Bernal, Sergio; González, Camila; Ramsey, Janine M

    2013-01-01

    Ecological niche models are useful tools to infer potential spatial and temporal distributions in vector species and to measure epidemiological risk for infectious diseases such as the Leishmaniases. The ecological niche of 28 North and Central American sand fly species, including those with epidemiological relevance, can be used to analyze the vector's ecology and its association with transmission risk, and plan integrated regional vector surveillance and control programs. In this study, we model the environmental requirements of the principal North and Central American phlebotomine species and analyze three niche characteristics over future climate change scenarios: i) potential change in niche breadth, ii) direction and magnitude of niche centroid shifts, iii) shifts in elevation range. Niche identity between confirmed or incriminated Leishmania vector sand flies in Mexico, and human cases were analyzed. Niche models were constructed using sand fly occurrence datapoints from Canada, USA, Mexico, Guatemala and Belize. Nine non-correlated bioclimatic and four topographic data layers were used as niche components using GARP in OpenModeller. Both B2 and A2 climate change scenarios were used with two general circulation models for each scenario (CSIRO and HadCM3), for 2020, 2050 and 2080. There was an increase in niche breadth to 2080 in both scenarios for all species with the exception of Lutzomyia vexator. The principal direction of niche centroid displacement was to the northwest (64%), while the elevation range decreased greatest for tropical, and least for broad-range species. Lutzomyia cruciata is the only epidemiologically important species with high niche identity with that of Leishmania spp. in Mexico. Continued landscape modification in future climate change will provide an increased opportunity for the geographic expansion of NCA sand flys' ENM and human exposure to vectors of Leishmaniases.

  12. Current and Future Niche of North and Central American Sand Flies (Diptera: Psychodidae) in Climate Change Scenarios

    PubMed Central

    Moo-Llanes, David; Ibarra-Cerdeña, Carlos N.; Rebollar-Téllez, Eduardo A.; Ibáñez-Bernal, Sergio; González, Camila; Ramsey, Janine M.

    2013-01-01

    Ecological niche models are useful tools to infer potential spatial and temporal distributions in vector species and to measure epidemiological risk for infectious diseases such as the Leishmaniases. The ecological niche of 28 North and Central American sand fly species, including those with epidemiological relevance, can be used to analyze the vector's ecology and its association with transmission risk, and plan integrated regional vector surveillance and control programs. In this study, we model the environmental requirements of the principal North and Central American phlebotomine species and analyze three niche characteristics over future climate change scenarios: i) potential change in niche breadth, ii) direction and magnitude of niche centroid shifts, iii) shifts in elevation range. Niche identity between confirmed or incriminated Leishmania vector sand flies in Mexico, and human cases were analyzed. Niche models were constructed using sand fly occurrence datapoints from Canada, USA, Mexico, Guatemala and Belize. Nine non-correlated bioclimatic and four topographic data layers were used as niche components using GARP in OpenModeller. Both B2 and A2 climate change scenarios were used with two general circulation models for each scenario (CSIRO and HadCM3), for 2020, 2050 and 2080. There was an increase in niche breadth to 2080 in both scenarios for all species with the exception of Lutzomyia vexator. The principal direction of niche centroid displacement was to the northwest (64%), while the elevation range decreased greatest for tropical, and least for broad-range species. Lutzomyia cruciata is the only epidemiologically important species with high niche identity with that of Leishmania spp. in Mexico. Continued landscape modification in future climate change will provide an increased opportunity for the geographic expansion of NCA sand flys' ENM and human exposure to vectors of Leishmaniases. PMID:24069478

  13. First record of the genus Ctenipocoris (Heteroptera: Naucoridae) in Central America, with a preliminary key to the American species and description of a new species.

    PubMed

    Herrera, Federico

    2013-10-31

    A new naucorid species, Ctenipocoris oscari Herrera NEW SPECIES, is herein described for Costa Rica. It is the first species to be described in Central America and the sixth American species. Comparative notes are provided to differentiate this species from the others. Type material is deposited at the Zoological Museum of the University of Costa Rica (MZUCR), San José, Costa Rica. A preliminary key to the American species of the genus is provided.

  14. The Fate of Saharan Dust Across the Atlantic and Implications for a Central American Dust Barrier

    NASA Technical Reports Server (NTRS)

    Nowottnick, E.; Colarco, P.; da Silva, A.; Hlavka, D.; McGill, M.

    2011-01-01

    Saharan dust was observed over the Caribbean basin during the summer 2007 NASA Tropical Composition, Cloud, and Climate Coupling (TC4) field experiment. Airborne Cloud Physics Lidar (CPL) and satellite observations from MODIS suggest a barrier to dust transport across Central America into the eastern Pacific. We use the NASA GEOS-5 atmospheric transport model with online aerosol tracers to perform simulations of the TC4 time period in order to understand the nature of this barrier. Our simulations are driven by the Modem Era Retrospective-Analysis for Research and Applications (MERRA) meteorological analyses. We evaluate our baseline simulated dust distributions using MODIS and CALIOP satellite and ground-based AERONET sun photometer observations. GEOS-5 reproduces the observed location, magnitude, and timing of major dust events, but our baseline simulation does not develop as strong a barrier to dust transport across Central America as observations suggest. Analysis of the dust transport dynamics and lost processes suggest that while both mechanisms play a role in defining the dust transport barrier, loss processes by wet removal of dust are about twice as important as transport. Sensitivity analyses with our model showed that the dust barrier would not exist without convective scavenging over the Caribbean. The best agreement between our model and the observations was obtained when dust wet removal was parameterized to be more aggressive, treating the dust as we do hydrophilic aerosols.

  15. Screening of the topical anti-inflammatory activity of some Central American plants.

    PubMed

    Sosa, S; Balick, M J; Arvigo, R; Esposito, R G; Pizza, C; Altinier, G; Tubaro, Aurelia

    2002-07-01

    Hexane, chloroform and methanol extracts of seven herbal drugs used in the folk medicine of Central America against skin disorders (Aristolochia trilobata leaves and bark, Bursera simaruba bark, Hamelia patens leaves, Piper amalago leaves, and Syngonium podophyllum leaves and bark) were evaluated for their topical anti-inflammatory activity against the Croton oil-induced ear oedema in mice. Most of the extracts induced a dose-dependent oedema reduction. The chloroform extract of almost all the drugs exhibited interesting activities with ID(50) values ranging between 108 and 498 micro g/cm(2), comparable to that of indomethacin (93 micro g/cm(2)). Therefore, the tested plants are promising sources of principles with high anti-inflammatory activity.

  16. Molecular phylogeny of Trypanosoma cruzi from Central America (Guatemala) and a comparison with South American strains.

    PubMed

    Iwagami, M; Higo, H; Miura, S; Yanagi, T; Tada, I; Kano, S; Agatsuma, T

    2007-12-01

    Molecular phylogenetic analysis was carried out for 21 strains of Trypanosoma cruzi, nine of which were obtained from Guatemala and 12 from South America. Phylogenetic trees were constructed using the nucleotide sequences of two nuclear gene regions, dihydrofolate reductase-thymidylate synthase (DHFR-TS) and trypanothione reductase (TR), and contiguous portions of two mitochondrial genes, cytochrome oxidase subunit II (COII) and reduced nicotinamide adenine dinucleotide dehydrogenase subunit 1 (ND1). Possible genetic exchange between the rather divergent lineages of T. cruzi II from South America was suggested in the trees of the two nuclear genes. T. cruzi I strains obtained from Guatemala and Colombia were identical in all the genes examined, but other T. cruzi I isolates from South America were rather polymorphic in the DHFR-TS and mitochondrial genes. No genetic exchange was identified between T. cruzi I populations from Central and South America in the present study.

  17. Projecting the vegetation response to climatic change in the North American Central Grasslands Region

    SciTech Connect

    Lenihan, J.M.; Neilson, R.P. )

    1993-06-01

    An interdisciplinary modeling effort is underway in which high-resolution climate change projections will drive the Mapped Atmosphere-Plant-Soil System (MAPSS) to simulate vegetation change in the Central Grasslands Region. MAPSS calculates a complete site water balance and solves for the leaf area (LAI) of both woody and grass lifeforms in full competition for both light and water. Fire is a necessary constraint on simulated shrub LAI throughout much of the grasslands region, and incorporation of weather variability is critical for obtaining accurate tree/grass LAI ratios in the Prairie Peninsula. Initial estimates of the potential impact of climatic change include significant changes in both lifeform LAI and the distribution of subformation vegetation types, but the magnitude and even the direction of change varies with the climate scenario and with assumptions concerning wind speed and plant water-use efficiency.

  18. Shifts in reproductive assurance strategies and inbreeding costs associated with habitat fragmentation in Central American mahogany.

    PubMed

    Breed, Martin F; Gardner, Michael G; Ottewell, Kym M; Navarro, Carlos M; Lowe, Andrew J

    2012-05-01

    The influence of habitat fragmentation on mating patterns and progeny fitness in trees is critical for understanding the long-term impact of contemporary landscape change on the sustainability of biodiversity. We examined the relationship between mating patterns, using microsatellites, and fitness of progeny, in a common garden trial, for the insect-pollinated big-leaf mahogany, Swietenia macrophylla King, sourced from forests and isolated trees in 16 populations across Central America. As expected, isolated trees had disrupted mating patterns and reduced fitness. However, for dry provenances, fitness was negatively related to correlated paternity, while for mesic provenances, fitness was correlated positively with outcrossing rate and negatively with correlated paternity. Poorer performance of mesic provenances is likely because of reduced effective pollen donor density due to poorer environmental suitability and greater disturbance history. Our results demonstrate a differential shift in reproductive assurance and inbreeding costs in mahogany, driven by exploitation history and contemporary landscape context.

  19. Projecting the Local Impacts of Climate Change on a Central American Montane Avian Community

    NASA Technical Reports Server (NTRS)

    Gasner, Matthew R.; Jankowski, Jill E.; Ciecka, Anna L.; Kyle, Keiller O.; Rabenold, Kerry N.

    2010-01-01

    Significant changes in the climates of Central America are expected over the next century. Lowland rainforests harbor high alpha diversity on local scales (<1 km2), yet montane landscapes often support higher beta diversity on 10-100 km2 scales. Climate change will likely disrupt the altitudinal zonation of montane communities that produces such landscape diversity. Projections of biotic response to climate change have often used broad-scale modelling of geographical ranges, but understanding likely impacts on population viability is also necessary for anticipating local and global extinctions. We model species abundances and estimate range shifts for birds in the Tilaran Mountains of Costa Rica, asking whether projected changes in temperature and rainfall could be sufficient to imperil high-elevation endemics and whether these variables will likely impact communities similarly. We find that nearly half of 77 forest bird species can be expected to decline in the next century. Almost half of species projected to decline are endemic to Central America, and seven of eight species projected to become locally extinct are endemic to the highlands of Costa Rica and Panam . Logistic-regression modelling of distributions and similarity in projections produced by temperature and rainfall models suggest that changes in both variables will be important. Although these projections are probably conservative because they do not explicitly incorporate biological or climate variable interactions, they provide a starting point for incorporating more realistic biological complexity into community-change models. Prudent conservation planning for tropical mountains should focus on regions with room for altitudinal reorganization of communities comprised of ecological specialists.

  20. Projecting the Local Impacts of Climate Change on a Central American Montane Avian Community

    NASA Technical Reports Server (NTRS)

    Gasner, Matthew R.; Jankowski, Jill E.; Ciecka, Anna L.; Kyle, Keiller O.; Rabenold, Kerry N.

    2010-01-01

    Significant changes in the climates of Central America are expected over the next century. Lowland rainforests harbor high alpha diversity on local scales (<1 km2), yet montane landscapes often support higher beta diversity on 10-100 km2 scales. Climate change will likely disrupt the altitudinal zonation of montane communities that produces such landscape diversity. Projections of biotic response to climate change have often used broad-scale modelling of geographical ranges, but understanding likely impacts on population viability is also necessary for anticipating local and global extinctions. We model species abundances and estimate range shifts for birds in the Tilaran Mountains of Costa Rica, asking whether projected changes in temperature and rainfall could be sufficient to imperil high-elevation endemics and whether these variables will likely impact communities similarly. We find that nearly half of 77 forest bird species can be expected to decline in the next century. Almost half of species projected to decline are endemic to Central America, and seven of eight species projected to become locally extinct are endemic to the highlands of Costa Rica and Panam . Logistic-regression modelling of distributions and similarity in projections produced by temperature and rainfall models suggest that changes in both variables will be important. Although these projections are probably conservative because they do not explicitly incorporate biological or climate variable interactions, they provide a starting point for incorporating more realistic biological complexity into community-change models. Prudent conservation planning for tropical mountains should focus on regions with room for altitudinal reorganization of communities comprised of ecological specialists.

  1. Design, pharmacology, and NMR structure of a minimized cystine knot with agouti-related protein activity.

    PubMed

    Jackson, Pilgrim J; McNulty, Joseph C; Yang, Ying-Kui; Thompson, Darren A; Chai, Biaoxin; Gantz, Ira; Barsh, Gregory S; Millhauser, Glenn L

    2002-06-18

    The agouti-related protein (AGRP) is an endogenous antagonist of the melanocortin receptors MC3R and MC4R found in the hypothalamus and exhibits potent orexigenic activity. The cysteine-rich C-terminal domain of this protein, corresponding to AGRP(87-132), exhibits receptor binding affinity and antagonism equivalent to that of the full-length protein. The NMR structure of this active domain was recently determined and suggested that melanocortin receptor contacts were made primarily by two loops presented by a well-structured cystine knot domain within AGRP(87-132) [McNulty et al. (2001) Biochemistry 40, 15520-15527]. This hypothesis is tested here with NMR structure and activity studies of a 34-residue AGRP analogue designed to contain only the cystine knot domain. The designed miniprotein folds to a homogeneous product, retains the desired cystine knot architecture, functions as an antagonist, and maintains the melanocortin receptor pharmacological profile of AGRP(87-132). The AGRP-like activity of this molecule supports the hypothesis that indeed the cystine knot region possesses the melanocortin receptor contact points. Moreover, this potent AGRP analogue is synthetically accessible, may serve in the development of therapeutics for the treatment of diseases related to energy balance. and may also find use as a new reagent for probing melanocortin receptor structure and function.

  2. Agouti signalling protein (ASIP) gene: molecular cloning, sequence characterisation and tissue distribution in domestic goose.

    PubMed

    Zhang, J; Wang, C; Liu, Y; Liu, J; Wang, H Y; Liu, A F; He, D Q

    2016-06-01

    Agouti signalling protein (ASIP) is an endogenous antagonist of melanocortin-1 receptor (MC1R) and is involved in the regulation of pigmentation in mammals. The objective of this study was to identify and characterise the ASIP gene in domestic goose. The goose ASIP cDNA consisted of a 44-nucleotide 5'-terminal untranslated region (UTR), a 390-nucleotide open-reading frame (ORF) and a 45-nucleotide 3'-UTR. The length of goose ASIP genomic DNA was 6176 bp, including three coding exons and two introns. Bioinformatic analysis indicated that the ORF encodes a protein of 130 amino-acid residues with a molecular weight of 14.88 kDa and an isoelectric point of 9.73. Multiple sequence alignments and phylogenetic analysis showed that the amino-acid sequence of ASIP was conserved in vertebrates, especially in the avian species. RT-qPCR showed that the goose ASIP mRNA was differentially expressed in the pigment deposition tissues, including eye, foot, feather follicle, skin of the back, as well as in skin of the abdomen. The expression level of the ASIP gene in skin of the abdomen was higher than that in skin of the back. Those findings will contribute to further understanding the functions of the ASIP gene in geese plumage colouring.

  3. Molecular Mechanisms for Activation of the Agouti-Related Protein and Stimulation of Appetite

    PubMed Central

    Ilnytska, Olha; Stütz, Adrian M.; Park-York, MieJung; York, David A.; Ribnicky, David M.; Zuberi, Aamir; Cefalu, William T.; Argyropoulos, George

    2011-01-01

    OBJECTIVE The agouti-related protein (Agrp) is a powerful orexigenic peptide, but little is known about its transcriptional regulation. The objective of this study was to determine molecular mechanisms for the activation of hypothalamic Agrp and identify compounds that stimulate appetite. RESEARCH DESIGN AND METHODS We used promoter analyses methods, hypothalamic cell culture and transfection, immunohistochemistry, luciferase-expressing transgenic mice, in vivo bioluminescence, anitisense RNA, mouse feeding studies, indirect calorimetry, real-time PCR, and Western blots. RESULTS We found that the Krüppel-like factor 4 (Klf4) is a potent activator of Agrp by binding to a specific CACCC-box in its minimal promoter. We also found that an extract of tarragon, termed PMI-5011, activated hypothalamic Klf4 and Agrp. In vivo, PMI-5011 increased Agrp promoter activity in luciferase-expressing transgenic mice, increased hypothalamic Klf4 and Agrp expression, increased hypothalamic Orexin and melanin-concentrating hormone, increased food intake, reduced circulating insulin and leptin levels, attenuated energy expenditure, and enhanced body weight but only when using a high-fat diet. CONCLUSIONS These data show that Klf4 augmented hypothalamic Agrp by binding to a specific CACCC-box onto its minimal promoter. In addition, the tarragon extract PMI-5011 activated Klf4 and orexigenic neuropeptides and reduced peripheral insulin and leptin levels leading to positive energy balance. PMID:20980461

  4. Mechanisms of modulation of experimental autoimmune encephalomyelitis by chronic Trichinella spiralis infection in Dark Agouti rats.

    PubMed

    Gruden-Movsesijan, A; Ilic, N; Mostarica-Stojkovic, M; Stosic-Grujicic, S; Milic, M; Sofronic-Milosavljevic, L

    2010-06-01

    Trichinella spiralis is a helminth that provokes Th2 and anti-inflammatory type responses in an infected host. Our previous studies using Dark Agouti (DA) rats indicated that T. spiralis infection reduced experimental autoimmune encephalomyelitis (EAE) severity in rats. The aim of this study was to analyse the mechanisms underlying EAE suppression driven by T. spiralis infection. Reduced clinical and histological manifestations of the disease were accompanied by increased IL-4 and IL-10 production and decreased IFN-gamma and IL-17 production in draining lymph node cells. This indicates that T. spiralis infection successfully maintains a Th2 cytokine bias regardless of EAE induction. High IL-10 signifies parasite-induced anti-inflammatory and/or regulatory cell responses. Transfer of splenic T cell-enriched population of cells from T. spiralis-infected rats into EAE immunized rats caused amelioration of EAE and in some cases protection from disease development. This population of cells contained higher proportion of CD4(+) CD25(+) Foxp3(+) regulatory cells and produced high level of IL-10 when compared with uninfected rats.

  5. Molecular mechanisms for activation of the agouti-related protein and stimulation of appetite.

    PubMed

    Ilnytska, Olha; Stütz, Adrian M; Park-York, MieJung; York, David A; Ribnicky, David M; Zuberi, Aamir; Cefalu, William T; Argyropoulos, George

    2011-01-01

    The agouti-related protein (Agrp) is a powerful orexigenic peptide, but little is known about its transcriptional regulation. The objective of this study was to determine molecular mechanisms for the activation of hypothalamic Agrp and identify compounds that stimulate appetite. We used promoter analyses methods, hypothalamic cell culture and transfection, immunohistochemistry, luciferase-expressing transgenic mice, in vivo bioluminescence, anitisense RNA, mouse feeding studies, indirect calorimetry, real-time PCR, and Western blots. We found that the Krüppel-like factor 4 (Klf4) is a potent activator of Agrp by binding to a specific CACCC-box in its minimal promoter. We also found that an extract of tarragon, termed PMI-5011, activated hypothalamic Klf4 and Agrp. In vivo, PMI-5011 increased Agrp promoter activity in luciferase-expressing transgenic mice, increased hypothalamic Klf4 and Agrp expression, increased hypothalamic Orexin and melanin-concentrating hormone, increased food intake, reduced circulating insulin and leptin levels, attenuated energy expenditure, and enhanced body weight but only when using a high-fat diet. These data show that Klf4 augmented hypothalamic Agrp by binding to a specific CACCC-box onto its minimal promoter. In addition, the tarragon extract PMI-5011 activated Klf4 and orexigenic neuropeptides and reduced peripheral insulin and leptin levels leading to positive energy balance.

  6. Senseless Violence Against Central American Unaccompanied Minors: Historical Background and Call for Help.

    PubMed

    Sawyer, Cheryl B; Márquez, Judith

    2017-01-02

    The southwestern U.S. border has recently seen a significant increase in the number of unaccompanied children from Honduras, Guatemala, and El Salvador illegally crossing the Mexican border into the United States. Many of these children leave home to flee violence, starvation, impoverished living conditions, or other life-threatening situations. The treatment of acute stress, anxiety, and depression associated with traumatic events is crucial in helping these children address these negative psychological events they have experienced so that they can move forward with their lives. Untreated, traumatic events experienced by this population can develop into Post Traumatic Stress Disorder, a potentially life-changing and physically threatening psychological and medical issue. The United States needs to effectively address the serious matter of responding to mental health issues facing refugees from war-torn or impoverished nations so as to help them to successfully adjust to American systems. There is a need for researchers in the mental health field to focus efforts in designing, implementing, and evaluating methodologies that can help these children develop healthy strategies for living with a very difficult and complex past.

  7. Nicotine withdrawal increases body weight, neuropeptide Y and Agouti-related protein expression in the hypothalamus and decreases uncoupling protein-3 expression in the brown adipose tissue in high-fat fed mice.

    PubMed

    Fornari, Alice; Pedrazzi, Patrizia; Lippi, Giordano; Picciotto, Marina R; Zoli, Michele; Zini, Isabella

    2007-01-03

    Nicotine is known to decrease body weight in normal rodents and human smokers, whereas nicotine withdrawal or smoking cessation can increase body weight. We have found that mice fed a high fat diet do not show the anorectic effect of chronic nicotine treatment, but do increase their body weight following nicotine withdrawal. Nicotine withdrawal is accompanied by increased expression of the orexigenic peptides neuropeptide Y and Agouti-related protein in the hypothalamus, and decreased expression of the metabolic protein uncoupling protein-3 in brown adipose tissue. These data suggest that diet can influence the ability of nicotine to modulate body weight regulation and demonstrate that chronic nicotine exposure results in adaptive changes in central and peripheral molecules which regulate feeding behavior and energy metabolism.

  8. Hydatid disease of the central nervous system: a review of literature with an emphasis on Latin American countries.

    PubMed

    Nourbakhsh, Ali; Vannemreddy, Prasad; Minagar, Alireza; Toledo, Eduardo González; Palacios, Enrique; Nanda, Anil

    2010-04-01

    To provide an up to date review of the epidemiology, etiology, treatment and prevention of hydatid cyst of the central nervous system, with an emphasis in South American countries. We searched the PubMed databases for articles containing the terms 'hydatid cyst' and 'nervous system'. We found and reviewed 303 articles and their related references. We provide the available information on the pathology, life cycle and diagnostic modalities (laboratory tests and imaging) along with possible complications of the disease. Current treatment methods of hydatid cyst in the brain and spine are also being discussed. Echinococcosis is a rare parasitic disease, endemic in some parts of South America. The epidemiology of echinococcosis is influenced by agricultural, educational, economic, medical and cultural factors. Human infestation occurs through the fecal-oral route. Infection of the central nervous system is rare, and the mainstay of treatment is surgical excision of the intracranial or spinal cyst, when present. Preventive programs should break the parasite life cycle and also educate the farmers in endemic areas.

  9. Phylogeny and niche conservatism in North and Central American triatomine bugs (Hemiptera: Reduviidae: Triatominae), vectors of Chagas' disease.

    PubMed

    Ibarra-Cerdeña, Carlos N; Zaldívar-Riverón, Alejandro; Peterson, A Townsend; Sánchez-Cordero, Víctor; Ramsey, Janine M

    2014-10-01

    The niche conservatism hypothesis states that related species diverge in niche characteristics at lower rates than expected, given their lineage divergence. Here we analyze whether niche conservatism is a common pattern among vector species (Hemiptera: Reduviidae: Triatominae) of Trypanosoma cruzi that inhabit North and Central America, a highly heterogeneous landmass in terms of environmental gradients. Mitochondrial and nuclear loci were used in a multi-locus phylogenetic framework to reconstruct phylogenetic relationships among species and estimate time of divergence of selected clades to draw biogeographic inferences. Then, we estimated similarity between the ecological niche of sister species and tested the niche conservatism hypothesis using our best estimate of phylogeny. Triatoma is not monophyletic. A primary clade with all North and Central American (NCA) triatomine species from the genera Triatoma, Dipetalogaster, and Panstrongylus, was consistently recovered. Nearctic species within the NCA clade (T. p. protracta, T. r. rubida) diverged during the Pliocene, whereas the Neotropical species (T. phyllosoma, T. longipennis, T. dimidiata complex) are estimated to have diverged more recently, during the Pleistocene. The hypothesis of niche conservatism could not be rejected for any of six sister species pairs. Niche similarity between sister species best fits a retention model. While this framework is used here to infer niche evolution, it has a direct impact on spatial vector dynamics driven by human population movements, expansion of transportation networks and climate change scenarios.

  10. Phylogeny and Niche Conservatism in North and Central American Triatomine Bugs (Hemiptera: Reduviidae: Triatominae), Vectors of Chagas' Disease

    PubMed Central

    Ibarra-Cerdeña, Carlos N.; Zaldívar-Riverón, Alejandro; Peterson, A. Townsend; Sánchez-Cordero, Víctor; Ramsey, Janine M.

    2014-01-01

    The niche conservatism hypothesis states that related species diverge in niche characteristics at lower rates than expected, given their lineage divergence. Here we analyze whether niche conservatism is a common pattern among vector species (Hemiptera: Reduviidae: Triatominae) of Trypanosoma cruzi that inhabit North and Central America, a highly heterogeneous landmass in terms of environmental gradients. Mitochondrial and nuclear loci were used in a multi-locus phylogenetic framework to reconstruct phylogenetic relationships among species and estimate time of divergence of selected clades to draw biogeographic inferences. Then, we estimated similarity between the ecological niche of sister species and tested the niche conservatism hypothesis using our best estimate of phylogeny. Triatoma is not monophyletic. A primary clade with all North and Central American (NCA) triatomine species from the genera Triatoma, Dipetalogaster, and Panstrongylus, was consistently recovered. Nearctic species within the NCA clade (T. p. protracta, T. r. rubida) diverged during the Pliocene, whereas the Neotropical species (T. phyllosoma, T. longipennis, T. dimidiata complex) are estimated to have diverged more recently, during the Pleistocene. The hypothesis of niche conservatism could not be rejected for any of six sister species pairs. Niche similarity between sister species best fits a retention model. While this framework is used here to infer niche evolution, it has a direct impact on spatial vector dynamics driven by human population movements, expansion of transportation networks and climate change scenarios. PMID:25356550

  11. Late Cenozoic tephrostratigraphy offshore the southern Central American Volcanic Arc: 2. Implications for magma production rates and subduction erosion

    NASA Astrophysics Data System (ADS)

    Schindlbeck, J. C.; Kutterolf, S.; Freundt, A.; Straub, S. M.; Vannucchi, P.; Alvarado, G. E.

    2016-11-01

    Pacific drill sites offshore Central America provide the unique opportunity to study the evolution of large explosive volcanism and the geotectonic evolution of the continental margin back into the Neogene. The temporal distribution of tephra layers established by tephrochonostratigraphy in Part 1 indicates a nearly continuous highly explosive eruption record for the Costa Rican and the Nicaraguan volcanic arc within the last 8 Myr. The widely distributed marine tephra layers comprise the major fraction of the respective erupted tephra volumes and masses thus providing insights into regional and temporal variations of large-magnitude explosive eruptions along the southern Central American Volcanic Arc (CAVA). We observe three pulses of enhanced explosive volcanism between 0 and 1 Ma at the Cordillera Central, between 1 and 2 Ma at the Guanacaste and at >3 Ma at the Western Nicaragua segments. Averaged over the long-term the minimum erupted magma flux (per unit arc length) is ˜0.017 g/ms. Tephra ages, constrained by Ar-Ar dating and by correlation with dated terrestrial tephras, yield time-variable accumulation rates of the intercalated pelagic sediments with four prominent phases of peak sedimentation rates that relate to tectonic processes of subduction erosion. The peak rate at >2.3 Ma near Osa particularly relates to initial Cocos Ridge subduction which began at 2.91 ± 0.23 Ma as inferred by the 1.5 Myr delayed appearance of the OIB geochemical signal in tephras from Barva volcano at 1.42 Ma. Subsequent tectonic re-arrangements probably involved crustal extension on the Guanacaste segment that favored the 2-1 Ma period of unusually massive rhyolite production.

  12. Scale-Dependent Effects of a Heterogeneous Landscape on Genetic Differentiation in the Central American Squirrel Monkey (Saimiri oerstedii)

    PubMed Central

    Blair, Mary E.; Melnick, Don J.

    2012-01-01

    Landscape genetic studies offer a fine-scale understanding of how habitat heterogeneity influences population genetic structure. We examined population genetic structure and conducted a landscape genetic analysis for the endangered Central American Squirrel Monkey (Saimiri oerstedii) that lives in the fragmented, human-modified habitats of the Central Pacific region of Costa Rica. We analyzed non-invasively collected fecal samples from 244 individuals from 14 groups for 16 microsatellite markers. We found two geographically separate genetic clusters in the Central Pacific region with evidence of recent gene flow among them. We also found significant differentiation among groups of S. o. citrinellus using pairwise FST comparisons. These groups are in fragments of secondary forest separated by unsuitable “matrix” habitats such as cattle pasture, commercial African oil palm plantations, and human residential areas. We used an individual-based landscape genetic approach to measure spatial patterns of genetic variance while taking into account landscape heterogeneity. We found that large, commercial oil palm plantations represent moderate barriers to gene flow between populations, but cattle pastures, rivers, and residential areas do not. However, the influence of oil palm plantations on genetic variance was diminished when we restricted analyses to within population pairs, suggesting that their effect is scale-dependent and manifests during longer dispersal events among populations. We show that when landscape genetic methods are applied rigorously and at the right scale, they are sensitive enough to track population processes even in species with long, overlapping generations such as primates. Thus landscape genetic approaches are extremely valuable for the conservation management of a diverse array of endangered species in heterogeneous, human-modified habitats. Our results also stress the importance of explicitly considering the heterogeneity of matrix habitats

  13. Scale-dependent effects of a heterogeneous landscape on genetic differentiation in the Central American squirrel monkey (Saimiri oerstedii).

    PubMed

    Blair, Mary E; Melnick, Don J

    2012-01-01

    Landscape genetic studies offer a fine-scale understanding of how habitat heterogeneity influences population genetic structure. We examined population genetic structure and conducted a landscape genetic analysis for the endangered Central American Squirrel Monkey (Saimiri oerstedii) that lives in the fragmented, human-modified habitats of the Central Pacific region of Costa Rica. We analyzed non-invasively collected fecal samples from 244 individuals from 14 groups for 16 microsatellite markers. We found two geographically separate genetic clusters in the Central Pacific region with evidence of recent gene flow among them. We also found significant differentiation among groups of S. o. citrinellus using pairwise F(ST) comparisons. These groups are in fragments of secondary forest separated by unsuitable "matrix" habitats such as cattle pasture, commercial African oil palm plantations, and human residential areas. We used an individual-based landscape genetic approach to measure spatial patterns of genetic variance while taking into account landscape heterogeneity. We found that large, commercial oil palm plantations represent moderate barriers to gene flow between populations, but cattle pastures, rivers, and residential areas do not. However, the influence of oil palm plantations on genetic variance was diminished when we restricted analyses to within population pairs, suggesting that their effect is scale-dependent and manifests during longer dispersal events among populations. We show that when landscape genetic methods are applied rigorously and at the right scale, they are sensitive enough to track population processes even in species with long, overlapping generations such as primates. Thus landscape genetic approaches are extremely valuable for the conservation management of a diverse array of endangered species in heterogeneous, human-modified habitats. Our results also stress the importance of explicitly considering the heterogeneity of matrix habitats in

  14. Unprecedented 21st century drought risk in the American Southwest and Central Plains.

    PubMed

    Cook, Benjamin I; Ault, Toby R; Smerdon, Jason E

    2015-02-01

    In the Southwest and Central Plains of Western North America, climate change is expected to increase drought severity in the coming decades. These regions nevertheless experienced extended Medieval-era droughts that were more persistent than any historical event, providing crucial targets in the paleoclimate record for benchmarking the severity of future drought risks. We use an empirical drought reconstruction and three soil moisture metrics from 17 state-of-the-art general circulation models to show that these models project significantly drier conditions in the later half of the 21st century compared to the 20th century and earlier paleoclimatic intervals. This desiccation is consistent across most of the models and moisture balance variables, indicating a coherent and robust drying response to warming despite the diversity of models and metrics analyzed. Notably, future drought risk will likely exceed even the driest centuries of the Medieval Climate Anomaly (1100-1300 CE) in both moderate (RCP 4.5) and high (RCP 8.5) future emissions scenarios, leading to unprecedented drought conditions during the last millennium.

  15. [Dietary fiber content and nitrogen digestibility in Central American foods: Guatemala].

    PubMed

    Acevedo, E; Bressani, R

    1990-09-01

    The study herein reported presents information on the dietary fiber content of four food groups consumed in Central America. These are: cereals, grains and products; raw and processed beans; raw and processed vegetables, and starchy foods such as potatoes, cassava and plantain. Besides data on soluble and insoluble fiber, data on in vitro protein digestibility are included. The total dietary fiber content of the wheat flour products varied from 1.62 to 2.83% on a fresh basis, with the exception of whole-wheat bread, which showed a 7.57% content. The maize tortilla presented values ranging from 3.96 to 5.21% in respect to beans, and the values for cooked and raw beans fluctuated between 6.36 and 7.00%, independent of the color; however, fried beans reported values from 15.28 to 17.58%. Vegetables contained total dietary fiber values of 1.51 to 4.34, and the tubers, from 1.31 to 2.86%.

  16. Coeval ages of Australasian, Central American and Western Canadian tektites reveal multiple impacts 790 ka ago

    NASA Astrophysics Data System (ADS)

    Schwarz, Winfried H.; Trieloff, Mario; Bollinger, Klemens; Gantert, Niklas; Fernandes, Vera A.; Meyer, Hans-Peter; Povenmire, Hal; Jessberger, Elmar K.; Guglielmino, Massimo; Koeberl, Christian

    2016-04-01

    High resolution 40Ar-39Ar step heating dating of australites and indochinites, representing a large area of the Australasian strewn field, and more recently discovered tektite-like glasses from Central America (Belize) and Western Canada, were carried out. Precise plateau ages were obtained in all cases, yielding indistinguishable ages of 789 ± 9 ka for four australites, 783 ± 5 ka for four indochinites, 783 ± 17 ka for one Western Canadian and 769 ± 16 ka for one Belize impact glass. Concerning major elements and REEs, australites and the Western Canadian impact glass are indistinguishable. If the Western Canadian sample was transported by impact ejection and belongs to the Australasian strewn field, this implies extremely far ballistic transport of 9000 km distance, assuming a source crater in southern Asia. The distinct major element and REE composition of the Belize impact glass suggests formation in another separate impact event. We conclude that the Australasian/Western Canadian impact glasses formed 785 ± 7 ka ago in a single event and Belize impact glass in a separate event 769 ± 16 ka ago. The two impact events forming these two strewn fields occurred remarkably closely related in time, i.e., separated by <30 ka.

  17. Unprecedented 21st century drought risk in the American Southwest and Central Plains

    NASA Astrophysics Data System (ADS)

    Cook, B.; Ault, T.; Smerdon, J. E.

    2015-12-01

    In the Southwest and Central Plains of Western North America, climate change is expected to increase drought severity in the coming decades. These regions nevertheless experienced extended Medieval-era droughts that were more persistent than any historical event, providing crucial targets in the paleoclimate record for benchmarking the severity of future drought risks. We use an empirical drought reconstruction and three soil moisture metrics from 17 state-of-the-art general circulation models to show that these models project significantly drier conditions in the later half of the 21st century compared to the 20th century and earlier paleoclimatic intervals. This desiccation is consistent across most of the models and moisture balance variables, indicating a coherent and robust drying response to warming despite the diversity of models and metrics analyzed. Notably, future drought risk will likely exceed even the driest centuries of the Medieval Climate Anomaly (1100-1300 CE) in both moderate (RCP 4.5) and high (RCP 8.5) future emissions scenarios, leading to unprecedented drought conditions during the last millennium.

  18. Radar remote sensing of forest and wetland ecosystems in the Central American tropics

    SciTech Connect

    Pope, K.O.; Rey-Benayas, J.M. ); Paris, J.F. . Dept. of Biology)

    1994-05-01

    The authors analyzed airborne synthetic aperture radar (AIRSAR) imagery of forest, wetland, and agricultural ecosystems in northern Belize, Central America. The analyses are based upon four biophysical Indices derived from the fully polarimetric SAR data: the volume scattering index (VSI), canopy structure index (CSI), biomass index (BMI), calculated from the backscatter magnitude data, and the interaction type index (ITI), calculated from the backscatter phase data. The authors developed a four-level landscape hierarchy based upon clustering analyses of the 12 index parameters from two test site images. Statistical analyses were used to examine the relative importance of the 12 parameters for discriminating ecosystem characteristics at various landscape scales. The authors found that ITI was the most important index (primarily C band = CITI) for level, vegetated terrain at all levels of the hierarchy. BMI was most important for differentiating between vegetated and nonvegetated areas and between sloping and level terrain. These findings indicate that upper canopy spatial characteristics and flooding in marshlands are more important than biomass in differentiating many tropical ecosystems with radar data. The relative importance of the indices varied with vegetation type; for example, PVSI was the most important for distinguishing between upland forests and regrowth, and PCSI was the most important for differentiating swamp forest types. Finally, the authors evaluated the potential of present and future spaceborne SARs for tropical ecosystem studies based on the results. Most of these SARs are single channel system and will provide limited capability for characterizing biomass and structure of tropical vegetation. The SIR-C/X-SAR and proposed EOS SAR are future spaceborne multifrequency fully polarimetric SAR systems, and they will provide a significant contribution to tropical ecosystem studies.

  19. High-precision chronology for Central American maize diversification from El Gigante rockshelter, Honduras.

    PubMed

    Kennett, Douglas J; Thakar, Heather B; VanDerwarker, Amber M; Webster, David L; Culleton, Brendan J; Harper, Thomas K; Kistler, Logan; Scheffler, Timothy E; Hirth, Kenneth

    2017-08-22

    The first steps toward maize (Zea mays subspecies mays) domestication occurred in the Balsas region of Mexico by ∼9,000 calendar years B.P. (cal B.P.), but it remains unclear when maize was productive enough to be a staple grain in the Americas. Molecular and microbotanical data provide a partial picture of the timing and nature of morphological change, with genetic data indicating that alleles for some domestication traits were not yet fixed by 5,300 cal B.P. in the highlands of Mexico. Here, we report 88 radiocarbon dates on the botanical remains from El Gigante rockshelter (Honduras) to establish a Bayesian chronology over the past ∼11,000 y spanning the transition to maize-based food production. Botanical remains are remarkably well preserved and include over 10,000 maize macrofossils. We directly dated 37 maize cobs to establish the appearance and local change of maize at the site. Cobs are common in deposits dating between 4,340 and 4,020 cal B.P., and again between 2,350 and 980 cal B.P. The earliest cobs appear robustly domesticated, having 10-14 rows, suggesting strong selection for increased yield. The later cobs are comparable to these earliest ones, but show clear emergence of diverse traits, including increased cob width, rachis segment length, and cupule width. Our results indicate that domesticated landraces of maize productive enough to be a staple grain existed in Central America by 4,300 cal B.P.

  20. The insertion of a full-length Bos taurus LINE element is responsible for a transcriptional deregulation of the Normande Agouti gene.

    PubMed

    Girardot, Michael; Guibert, Sylvain; Laforet, Marie-Pierre; Gallard, Yves; Larroque, Hélène; Oulmouden, Ahmad

    2006-08-01

    Mammalian pigmentation is controlled by the concerted action of Tyr, Tyrp1 and Dct producing eumelanin and/or pheomelanin in melanocytes. The ratio of these two pigments is determined by the agonist alpha-melanocyte stimulating hormone and the antagonist Agouti protein acting on the Mc1r. Here we show that the Agouti gene is over-expressed in Normande breed compared with Prim'Holstein breed. The Normande cattle have a characteristic coat color phenotype with a variable presence of black (eumelanin) hair over a red/brown background. We have found a previously undescribed full-length L1-BT element inserted in the 5'-genomic sequence of the Agouti gene in Normande cattle which promotes the over-expression of alternative transcripts. The variable expression of the alternative transcript directed by the long interspersed nuclear element promoter may be the origin of the brindle coat color pattern of the Normande breed. This new bovine Agouti allele isolated in Normande breed has been named Abr. Finally, as ectopic over-expression of Agouti in Ay mice is responsible for the obesity syndrome, we discuss the possible consequences of Abr for meat and milk production in cattle.

  1. Central American Refugees: Regional Conditions and Prospects and Potential Impact on the United States. Report to the Congress of the United States.

    ERIC Educational Resources Information Center

    Comptroller General of the U.S., Washington, DC.

    Civil strife and deteriorating economic conditions in El Salvador, Nicaragua, and Guatemala have caused hundreds of thousands of refugees to seek asylum and assistance in other Central American countries, Mexico, and the United States. While international organizations and some asylum country governments provide the basic needs of refugees who…

  2. Mantle transition zone thickness in the Central South-American Subduction Zone

    NASA Astrophysics Data System (ADS)

    Braunmiller, Jochen; van der Lee, Suzan; Doermann, Lindsey

    We used receiver functions to determine lateral variations in mantle transition zone thickness and sharpness of the 410- and 660-km discontinuities in the presence of subducting lithosphere. The mantle beneath the central Andes of South America provides an ideal study site owing to its long-lived subduction history and the availability of broadband seismic data from the dense BANJO/SEDA temporary networks and the permanent station LPAZ. For LPAZ, we analyzed 26 earthquakes between 1993-2003 and stacked the depth-migrated receiver functions. For temporary stations operating for only about one year (1994-1995), station stacks were not robust. We thus stacked receiver functions for close-by stations forming five groups that span the subduction zone from west to east, each containing 12 to 25 events. We found signal significant at the 2σ level for several station groups from P to S conversions that originate near 520- and 850-900 km depth, but most prominently from the 410- and 660-km discontinuities. For the latter, the P to S converted signal is clear in stacks for western groups and LPAZ, lack of coherent signal for two eastern groups is possibly due to incoherent stacking and does not necessitate the absence of converted energy. The thickness of the mantle transition zone increases progressively from a near-normal 255 km at the Pacific coast to about 295 km beneath station LPAZ in the Eastern Cordillera. Beneath LPAZ, the 410-km discontinuity appears elevated by nearly 40 km, thus thickening the transition zone. We compared signal amplitudes from receiver function stacks calculated at different low-pass frequencies to study frequency dependence and possibly associated discontinuity sharpness of the P to S converted signals. We found that both the 410- and 660-km discontinuities exhibit amplitude increase with decreasing frequency. Synthetic receiver function calculations for discontinuity topography mimicking observed topography show that the observed steep

  3. Electromagnetic imaging the of the Pacific-North American plate boundary in central California, USA

    NASA Astrophysics Data System (ADS)

    Wheelock, B. D.; Constable, S.; Key, K. W.

    2010-12-01

    The continental margin of central California lies adjacent to a segment of the San Andreas fault (SAF) that exhibits a transition between locked behavior south of the town of Cholame, and freely slipping (creeping) behavior north of the town of Parkfield. Recent reports of non-volcanic tremor (NVT) near the town of Cholame represent the first observation of NVT in a strike-slip environment. Dense clusters of tremor episodes located at the northern limit of the locked section of the SAF were found to originate within the ductile lower crust at depths between 15 and 30~km, and have been interpreted as evidence of high pore fluid pressure. An excess of fluids in this region is likely given its history of subduction, which transports large quantities of water into the forearc crust and mantle. We present a study that uses deep electromagnetic imaging methods to estimate the abundance and distribution of pore fluids at depths associated with non-volcanic tremor. This study extends a previously collected terrestrial profile of magnetotelluric (MT) data (Becken et al. 2008, Geophysical Journal International) into the offshore environment. We deployed 21 seafloor instruments that collected controlled-source electromagnetic (CSEM) and MT data in a line extending from the coast near Morro Bay, across the continental shelf, and out onto the Pacific plate. The marine MT data results in apparent resistivity and phase estimates at periods between 1~s and 20,000~s, sufficient for probing the upper 100~km of regional conductivity. A significant coast effect, marked by asymptotic behavior in the TE mode of the MT responses, is observed at the deep water sites. This necessitates accurate bathymetry modeling when inverting. The CSEM transmitter was towed by all receivers broadcasting a compact broadband binary waveform with a 0.25~Hz fundamental frequency. The controlled-source signal is observed above the noisefloor at source-receiver offsets up to 6~km, which provides constraints

  4. Comparing central corneal thickness in a sub-Saharan cohort to African Americans and Afro-Caribbeans.

    PubMed

    Mercieca, Karl; Odogu, Victor; Fiebai, Bassey; Arowolo, Olu; Chukwuka, Favour

    2007-06-01

    To evaluate the central corneal thickness (CCT) of Africans in a glaucoma practice in a university teaching hospital in West Nigeria, Africa, and compare results with similar studies carried out in African American and Afro-Caribbean populations. CCT was measured by means of ultrasound pachymetry (pachymeter used was Micropach 200 P+ Pachymeter; Sonomed) in only African participants with either glaucomatous or healthy eyes. After instillation of topical anesthetic, 3 measurements of corneal thickness were taken, and the average thickness for each was calculated. The relationship between CCT and age was studied using correlation analyses and t tests. A total of 70 eyes were included for analysis. The mean CCT of all participants was 532.00 microm. Glaucoma suspects and patients with glaucoma had corneas thinner than those of normal participants (527.36 and 536.91 microm, respectively); however, the difference was not significant (P = 0.296). Decreasing values of CCT were significantly related to older age (P = 0.002). Men had a significantly higher CCT than women (P = 0.035). CCT values in African populations are less than those of whites. Decreasing values of CCT are significantly related to older age, and men have thicker corneas than women. There is a suggestion that CCT is lower in patients with glaucoma than in nonglaucomatous controls; however, the difference is not statistically significant. Comparing our results to other studies in literature, it seems that average CCT is similar between populations living in sub-Saharan Africa and African Americans and Afro-Caribbeans.

  5. Effect of informal employment on the relationship between psychosocial work risk factors and musculoskeletal pain in Central American workers.

    PubMed

    Gimeno Ruiz de Porras, David; Rojas Garbanzo, Marianela; Aragón, Aurora; Carmenate-Milián, Lino; Benavides, Fernando G

    2017-09-01

    The constant increase on the psychosocial demands experienced at work seems to contribute to the increase in health problems such as musculoskeletal pain (MSP). This association may be especially important in low-income and middle-income countries, where there is a large proportion of informal workers among whom there is little research. We analysed the association between psychosocial work risk factors and MSP among formal and informal workers using the First Central American Survey of Working Conditions and Health. This is a representative sample (n=12 024) of the economically active population of the six Spanish-speaking countries of Central America. Prevalence ratios (PR) and corresponding 95% CIs from Poisson regression models were used to estimate the association between psychosocial work risk factors and the MSP. Compared with formal workers, informal workers reported higher prevalence of MPS in the body regions analysed (ie, cervicodorsal, lumbosacral, upper extremities) and higher exposure to psychosocial work risk factors. However, on the whole, the associations between the exposure to psychosocial work risk factors and the prevalence of MSP were similar for both formal and informal workers. Only the association between exposure to high demands and MSP in the upper extremities was higher (p=0.012) among formal (PR=1.69, 95% CI 1.46 to 1.96) than among informal workers (PR=1.40; 95% CI 1.30 to 1.51). Exposure to adverse levels of psychosocial work risk factors is associated with higher prevalence of MPS among both formal and informal workers. However, the role of employment informality in this association is complex and requires further examination. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  6. Pre-Migration Trauma Exposure and Mental Health Functioning among Central American Migrants Arriving at the US Border.

    PubMed

    Keller, Allen; Joscelyne, Amy; Granski, Megan; Rosenfeld, Barry

    2017-01-01

    In recent years, increasing numbers of families and individuals have arrived at the U.S. border from Central America, in particular, from Honduras, El Salvador, and Guatemala. This study sought to examine pre-migration trauma exposure and current mental health functioning of migrant families arriving at the U.S. border from the Northern Triangle region, with specific attention to the reasons offered for leaving their home country and the frequency with which migrant families appear to satisfy legal criteria for asylum We interviewed 234 adults in McAllen, Texas, using a structured interview and standardized questionnaires to assess exposure to trauma prior to migration, reasons for leaving their home country and symptoms of posttraumatic stress and depression. We found that 191 participants (83%) cited violence as a reason for fleeing their country, 119 individuals (69%) did not report the events to the police out of fear of gang-related retaliation or police corruption, and 90% (n = 204) reported being afraid to return to their native country. Based on self-report symptom checklists, 32% of the sample met diagnostic criteria for PTSD (n = 51), 24% for depression (n = 36), and 17% for both disorders (n = 25). Examining these data against the criteria for asylum in the U.S., we found that 70% of the overall sample (n = 159) met criteria for asylum, including 80% of those from El Salvador, 74% from Honduras, and 41% from Guatemala. These findings suggest that the majority of Central American migrants arriving at the U.S. border have significant mental health symptoms in response to violence and persecution, and warrant careful consideration for asylum status.

  7. Pre-Migration Trauma Exposure and Mental Health Functioning among Central American Migrants Arriving at the US Border

    PubMed Central

    Keller, Allen; Joscelyne, Amy; Granski, Megan; Rosenfeld, Barry

    2017-01-01

    In recent years, increasing numbers of families and individuals have arrived at the U.S. border from Central America, in particular, from Honduras, El Salvador, and Guatemala. This study sought to examine pre-migration trauma exposure and current mental health functioning of migrant families arriving at the U.S. border from the Northern Triangle region, with specific attention to the reasons offered for leaving their home country and the frequency with which migrant families appear to satisfy legal criteria for asylum We interviewed 234 adults in McAllen, Texas, using a structured interview and standardized questionnaires to assess exposure to trauma prior to migration, reasons for leaving their home country and symptoms of posttraumatic stress and depression. We found that 191 participants (83%) cited violence as a reason for fleeing their country, 119 individuals (69%) did not report the events to the police out of fear of gang-related retaliation or police corruption, and 90% (n = 204) reported being afraid to return to their native country. Based on self-report symptom checklists, 32% of the sample met diagnostic criteria for PTSD (n = 51), 24% for depression (n = 36), and 17% for both disorders (n = 25). Examining these data against the criteria for asylum in the U.S., we found that 70% of the overall sample (n = 159) met criteria for asylum, including 80% of those from El Salvador, 74% from Honduras, and 41% from Guatemala. These findings suggest that the majority of Central American migrants arriving at the U.S. border have significant mental health symptoms in response to violence and persecution, and warrant careful consideration for asylum status. PMID:28072836

  8. Slip rate and earthquake recurrence along the central Septentrional fault, North American-Caribbean plate boundary, Dominican Republic

    USGS Publications Warehouse

    Prentice, C.S.; Mann, P.; Pena, L.R.; Burr, G.

    2003-01-01

    The Septentrional fault zone (SFZ) is the major North American-Caribbean, strike-slip, plate boundary fault at the longitude of eastern Hispaniola. The SFZ traverses the densely populated Cibao Valley of the Dominican Republic, forming a prominent scarp in alluvium. Our studies at four sites along the central SFZ are aimed at quantifying the late Quaternary behavior of this structure to better understand the seismic hazard it represents for the northeastern Caribbean. Our investigations of excavations at sites near Rio Cenovi show that the most recent ground-rupturing earthquake along this fault in the north central Dominican Republic occurred between A.D. 1040 and A.D. 1230, and involved a minimum of ???4 m of left-lateral slip and 2.3 m of normal dip slip at that site. Our studies of offset stream terraces at two locations, Rio Juan Lopez and Rio Licey, provide late Holocene slip rate estimates of 6-9 mm/yr and a maximum of 11-12 mm/yr, respectively, across the Septentrional fault. Combining these results gives a best estimate of 6-12 mm/yr for the slip rate across the SFZ. Three excavations, two near Tenares and one at the Rio Licey site, yielded evidence for the occurrence of earlier prehistoric earthquakes. Dates of strata associated with the penultimate event suggest that it occurred post-A.D. 30, giving a recurrence interval of 800-1200 years. These studies indicate that the SFZ has likely accumulated elastic strain sufficient to generate a major earthquake during the more than 800 years since it last slipped and should be considered likely to produce a destructive future earthquake.

  9. A 1400 km geochemical transect along the Central American Arc: Summary of mafic Holocene volcanism from Guatemala to Panama

    NASA Astrophysics Data System (ADS)

    Geldmacher, J.; Hoernle, K.; Gill, J. B.; Hauff, F.; Heydolph, K.

    2016-12-01

    It is generally accepted that subducted oceanic crust and sediments contribute to the composition of arc magmas. Systematic variations of input parameters (including age, subduction angle, and chemical composition of the subducting material) make the Central American Volcanic Arc (CAVA), which extends from Guatemala in the northwest through El Salvador, Honduras, Nicaragua, Costa Rica and Panama to the southeast, a prime study object. We present a comprehensive (major and trace element and Sr-Nd-Pb-Hf isotope data) and consistent (all data generated in the same labs using the same methods and data reduction procedures) compilation of published and unpublished Holocene mafic volcanic rocks sampled along the entire arc. New data include Sr and, for the first time, Hf isotope data from the entire CAVA as well as major and trace element data for 43 samples from southern Nicaragua and central Costa Rica from which only isotopic compositions were previously published. The combined elemental and isotopic data confirm the influence of distinct subduction components on the composition of CAVA magmas. Along-arc geochemical variations (especially delta 208Pb/204Pb) of volcanic front magmas in Costa Rica and Panama have been explained by the different compositions of seamounts/ridges of the isotopically zoned Galápagos hotspot track that covers the subducting Cocos Plate in this sector of the arc (Hoernle et al. 2008, Nature 451). Our new data confirm this relationship with arc lavas from Costa Rica having higher 87Sr/86Sr ratios than those from western Panama reflecting a similar spatial-compositional distinction in the subducting hotspot track beneath them. In contrast, 176Hf/177Hf shows no comparable variations in this sector of the arc, indicating that the Hf is primarily derived from the mantle wedge rather than the subducting slab. Although small degree hydrous melts are believed to fertilize the mantle wedge beneath Costa Rica, residual zircon may hold back the Hf.

  10. Agouti-related protein increases food hoarding more than food intake in Siberian hamsters.

    PubMed

    Day, Diane E; Bartness, Timothy J

    2004-01-01

    Agouti-related protein (AgRP), an endogenous melanocortin 3/4 receptor antagonist, appears to play an important role in the control of food intake and energy balance because exogenous administration in rats and overexpression in mice result in hyperphagia and body mass gain. Furthermore, arcuate nucleus AgRP mRNA is increased with fasting in laboratory rats and mice and is decreased with refeeding. In Siberian hamsters, fasting also increases arcuate nucleus AgRP mRNA, but these animals increase food hoarding, rather than food intake with refeeding. Therefore, we tested whether exogenous AgRP increased food hoarding in this species. Hamsters were trained in a hoarding/foraging apparatus to run a programmed number of wheel revolutions to earn food pellets. Four doses of AgRP-(83-132) or vehicle were injected into the third ventricle at the beginning of the dark phase, and food hoarding, food intake, and foraging were measured at various time points subsequently. Overall, food hoarding was stimulated as much as 10 times more than food intake, and both responses occurred as early as 1 h after injection. Food hoarding was increased the greatest at the lowest dose (0.1 nmol), whereas food intake was increased the greatest at the second lowest dose (1 nmol). Food intake and especially food hoarding were increased up to seven days after the AgRP injections. Foraging was increased at all AgRP doses except the highest dose (100 nmol). These results suggest that AgRP triggers the search for food in this species, and once they find it, hoarding predominates over eating.

  11. Effect of dietary carbohydrate source on the development of obesity in agouti transgenic mice.

    PubMed

    Morris, Kristin L; Zemel, Michael B

    2005-01-01

    Our objective was to evaluate the effects of a qualitative change in dietary carbohydrate source on body weight and adiposity in a rodent model of diet-induced obesity. We evaluated the effects of high-fat diets (basal) varying in carbohydrate source in aP2-agouti transgenic mice. In the ad libitum study, animals were given free access to the basal diet or one of four test diets for 6 weeks. In two of the diets, dietary carbohydrate was derived from a single source: mung bean noodles (MUNG) or rolled oats (ROLL). The remaining diets were designed to mimic commercially available instant oatmeal with added sugar (IO-S) or flavored instant oatmeal (IO-F). In the energy-restricted study, animals were given ad libitum access to the basal diet for 6 weeks. Subsequently, animals were assigned to one of six treatment groups for 6 weeks. One group was continued on the basal diet ad libitum. The remaining groups were maintained with energy restriction (70% ad libitum) on either the basal, MUNG, ROLL, IO-S, or IO-F diet. Subcutaneous fat pad mass was significantly higher (p<0.05) in the energy-restricted basal and IO-S groups compared with the energy-restricted ROLL diet. Similarly, visceral fat pad mass was significantly lower with ROLL and MUNG diets (p<0.05 for both) compared with basal and IO-S diets, and the insulin:glucose ratio was reduced (by 23% to 34%, p<0.05) in these two diets compared with all others. In ad libitum-fed animals, liver fatty acid synthase expression was 43% to 62% lower (p<0.05) with ROLL and MUNG diets compared with all others. These data suggest that a qualitative change in dietary carbohydrate source modulates body weight and adiposity.

  12. Plasma agouti-related protein levels in women with anorexia nervosa.

    PubMed

    Moriya, Junko; Takimoto, Yoshiyuki; Yoshiuchi, Kazuhiro; Shimosawa, Tatsuo; Akabayashi, Akira

    2006-10-01

    Agouti-related protein (AGRP) is the competitive antagonist of alpha-melanocyte stimulating hormone (alpha-MSH) located at melanocortin receptors 3 and 4 (MC3R and MC4R), and also acts as an MC4R inverse agonist. Hypothalamic AGRP controls food intake and body weight in rodents. It has also been found in human plasma. To study the possibility of disturbances in melanocortin receptor-related peptides in eating disorders, plasma AGRP, alpha-MSH, and leptin levels were measured in 18 female patients with anorexia nervosa (AN) (age, 23.5+/-7.1 yr; body mass index (BMI) 14.5+/-1.8 kg/m(2)) and 17 age-matched female controls (age, 25.8+/-3.9 yr; BMI 20.2+/-1.6 kg/m(2)). Blood samples were collected after overnight fasting, and plasma peptides levels were measured using ELISA. Plasma AGRP levels increased significantly in AN patients when compared with controls (P<0.01) while plasma alpha-MSH levels were not significantly different. Plasma leptin levels decreased significantly in AN patients when compared with controls (P<0.001). In addition, plasma AGRP levels were negatively correlated with leptin (r=-0.41, P<0.01) and BMI (r=-0.40, P<0.05) in all subjects. In conclusion, plasma AGRP elevation may be related to energy homeostasis disturbance in AN, and in addition to leptin, peripheral AGRP levels could be used as a nutritional marker in AN patients.

  13. The Impact of Everyday Discrimination and Racial Identity Centrality on African American Medical Student Well-Being: a Report from the Medical Student CHANGE Study.

    PubMed

    Perry, Sylvia P; Hardeman, Rachel; Burke, Sara E; Cunningham, Brooke; Burgess, Diana J; van Ryn, Michelle

    2016-09-01

    Positive psychological well-being is an important predictor of and contributor to medical student success. Previous work showed that first-year African American medical students whose self-concept was highly linked to their race (high racial identity centrality) were at greater risk for poor well-being. The current study extends this work by examining (a) whether the psychological impact of racial discrimination on well-being depends on African American medical students' racial identity centrality and (b) whether this process is explained by how accepted students feel in medical school. This study used baseline data from the Medical Student Cognitive Habits and Growth Evaluation (CHANGE) Study, a large national longitudinal cohort study of 4732 medical students at 49 medical schools in the USA (n = 243). Regression analyses were conducted to test whether medical student acceptance mediated an interactive effect of discrimination and racial identity centrality on self-esteem and well-being. Both racial identity centrality and everyday discrimination were associated with negative outcomes for first-year African American medical students. Among participants who experienced higher, but not lower, levels of everyday discrimination, racial identity centrality was associated with negative outcomes. When everyday discrimination was high, but not low, racial identity was negatively related to perceived acceptance in medical school, and this in turn was related to increased negative outcomes. Our results suggest that discrimination may be particularly harmful for African American students who perceive their race to be central to their personal identity. Additionally, our findings speak to the need for institutional change that includes commitment and action towards inclusivity and the elimination of structural racism.

  14. The Impact of Everyday Discrimination and Racial Identity Centrality on African American Medical Student Well-Being: a Report from the Medical Student CHANGE Study

    PubMed Central

    Hardeman, Rachel; Burke, Sara E.; Cunningham, Brooke; Burgess, Diana J.; van Ryn, Michelle

    2015-01-01

    Positive psychological well-being is an important predictor of and contributor to medical student success. Previous work showed that first-year African American medical students whose self-concept was highly linked to their race (high racial identity centrality) were at greater risk for poor well-being. The current study extends this work by examining (a) whether the psychological impact of racial discrimination on well-being depends on African American medical students' racial identity centrality and (b) whether this process is explained by how accepted students feel in medical school. This study used baseline data from the Medical Student Cognitive Habits and Growth Evaluation (CHANGE) Study, a large national longitudinal cohort study of 4732 medical students at 49 medical schools in the USA (n = 243). Regression analyses were conducted to test whether medical student acceptance mediated an interactive effect of discrimination and racial identity centrality on self-esteem and well-being. Both racial identity centrality and everyday discrimination were associated with negative outcomes for first-year African American medical students. Among participants who experienced higher, but not lower, levels of everyday discrimination, racial identity centrality was associated with negative outcomes. When everyday discrimination was high, but not low, racial identity was negatively related to perceived acceptance in medical school, and this in turn was related to increased negative outcomes. Our results suggest that discrimination may be particularly harmful for African American students who perceive their race to be central to their personal identity. Additionally, our findings speak to the need for institutional change that includes commitment and action towards inclusivity and the elimination of structural racism. PMID:27294743

  15. Viability of small seeds found in feces of the Central American tapir on Barro Colorado Island, Panama.

    PubMed

    Capece, Paula I; Aliaga-Rossel, Enzo; Jansen, Patrick A

    2013-03-01

    Tapirs are known as effective dispersers of large-seeded tree species, but their role in dispersing small-seeded plant species has yet to be established. Tapir feces have been reported to contain large numbers of small seeds, but whether these are viable has rarely been evaluated. We determined the abundance and viability of small seeds in feces of Central American tapir (Tapirus bairdii) on Barro Colorado Island, Panama. A total of 72 fecal samples were collected opportunistically from 4 tapir latrine sites. Seeds were manually extracted from feces and classified by size. Seed viability was estimated by opening each seed and examining for the presence of at least 1 intact firm white endosperm. In total, we obtained 8166 seeds of at least 16 plant species. Small-seeded species dominated, with 96% of all seeds found measuring <5 mm. The canopy tree Laetia procera was the most abundant species in the samples. Of all small seeds found, 69% contained an intact endosperm and appeared viable. This suggests that small seeds, like large seeds, often pass through the digestive tract of T. bairdii intact. Thus, tapirs potentially serve as effective dispersers of a wide range of small-seeded plant species.

  16. Formative Research to Design a Promotional Campaign to Increase Drinking Water among Central American Latino Youth in an Urban Area.

    PubMed

    Barrett, Nicole; Colón-Ramos, Uriyoán; Elkins, Allison; Rivera, Ivonne; Evans, W Douglas; Edberg, Mark

    2017-06-01

    Latinos consume more sugary drinks and less water than other demographic groups. Our objective was to understand beverage choice motivations and test promotional concepts that can encourage Central American Latino urban youth to drink more water. Two rounds of focus group discussions were conducted (n = 10 focus groups, 61 participants, 6-18 years old). Data were transcribed verbatim and analyzed using inductive and deductive coding approaches. Youth motivations for drinking water were shaped by level of thirst, weather, energy, and perceptions of health benefits. Youth were discouraged from drinking water due to its taste and perceptions of the safety and cleanliness of tap water. Youth beverage preference depended on what their friends were drinking. Availability of water versus other beverages at home and other settings influenced their choice. Promotional materials that included mixed language, informative messages about the benefits of drinking water, and celebrities or athletes who were active, energized, and drinking water were preferred. A promotional campaign to increase water consumption among these Latino youth should include bicultural messages to underscore the power of water to quench true thirst, highlight the health benefits of drinking water, and address the safety of tap water.

  17. [Environmental services of the forest: an essay in an European Atlantic river basin based on a Central American experience].

    PubMed

    Orrantia Albizu, Oreina; Ortega Hidalgo, M Mercedes; Quirós Madrigal, Olman; Loidi Arregui, Javier

    2008-12-01

    A Conservation Interest Index (CI) was designed to numerically assess the natural quality or value of a given terrestrial area. This CI has been applied along the Golako River Watershed (Biosphere Reserve, Basque Country, Spain). The area, although benefiting from some protection, is strongly influenced by human activities (forestry and cattle breeding). The CI is based on both available cartographic information about vegetation and fieldwork, the later needed to provide estimations for the various descriptors included in this index: in this way, a particular vegetation fragment received a final score on a scale from 0 to 1000. A set of 9 Vegetation Units has been defined to analyze the current vegetation profile and, a ten plot (500 x 500 m) uniformly distributed sampling design has been implemented. Landscape homogenization is high where main land use relies on timbering, contrasting with the more heterogeneous and fragmented profile related to rural activities. At a height of more than 150 m forest appears to be dominant while human occupation becomes patchy, whereas abruptness restraints farms to locations below 100 m. Concerning the index performance, gradual differences have been displayed by the forest, which appears as the only vegetation unit attaining values above 500 (50% in the index scale), mature forest ranking highest (860), followed closely by the riparian forest. We have developed a formula to translate environmental value into economic benefit to promote conservation work at private property level, imitating the initial work undergone in Central American countries, where environmental services are rewarded irrespective of their conservation status.

  18. Foods of American badgers in west-central Minnesota and southeastern North Dakota during the duck nesting season

    USGS Publications Warehouse

    Sovada, M.A.; Roaldson, J.M.; Sargeant, A.B.

    1999-01-01

    Although the American badger (Taxidea taxus) is common in grasslands and preys on a wide diversity of foods including birds, little is known about badger diet in areas where nesting ducks are common. Small mammals, primarily Muridae and Geomyidae, were the most common food items in the diet of badgers collected from west-central Minnesota and southeastern North Dakota during April-July 1987 through 1990, based on analysis of gastrointestinal tracts of 47 adult ( 1/4 -y-old) and 5 juvenile (<6-mo-old) badgers. Remains of mammals occurred in 98% of samples from adult badgers. Small quantities of insects were found in 40% of adult samples. Bird remains were in 32% of adult samples, most birds identified as Anatidae; ducks or ducklings occurred in 27% and duck eggs in 60% of those samples. Remains of reptiles, amphibians and mollusks were present, but were less common than other foods. Insects and bird eggs were more common during spring (April-May) than summer (June-July). Birds were more frequent in diets of adults than juvenile badgers.

  19. Preworkshop knowledge of musculoskeletal anatomy of rheumatology fellows and rheumatologists of seven North, Central, and South American countries.

    PubMed

    Navarro-Zarza, José E; Hernández-Díaz, Cristina; Saavedra, Miguel A; Alvarez-Nemegyei, José; Kalish, Robert A; Canoso, Juan J; Villaseñor-Ovies, Pablo

    2014-02-01

    To report the baseline knowledge of clinical anatomy of rheumatology fellows and rheumatologists from Argentina, Chile, Ecuador, El Salvador, Mexico, the US, and Uruguay. The invitation to attend a workshop in clinical anatomy was an open call by national rheumatology societies in 4 countries or by invitation from teaching program directors in 3 countries. Prior to the workshop, a practical test of anatomic structures commonly involved in rheumatic diseases was administered. The test consisted of the demonstration of these structures or their function in the participant's or instructor's body. At one site, a postworkshop practical test was administered immediately after the workshop. There were 170 participants (84 rheumatology fellows, 61 rheumatologists, and 25 nonrheumatologists). The overall mean ± SD number of correct answers was 46.6% ± 19.9% and ranged from 32.5-67.0% by country. Rheumatology fellows scored significantly higher than nonrheumatologists. Questions related to anatomy of the hand scored the lowest of the regions surveyed. Rheumatology fellows and rheumatologists showed a deficit in knowledge of musculoskeletal anatomy that is of central importance in rheumatologic assessment and diagnosis. This gap may hinder accurate and cost-effective rheumatologic diagnosis, particularly in the area of regional pain syndromes. Presently, widespread use of musculoskeletal ultrasound (MSUS) by rheumatologists may be premature, since a key component of expert-level MSUS is the integration of an accurate knowledge of anatomy with the views obtained with the ultrasound probe. Copyright © 2014 by the American College of Rheumatology.

  20. [Profile of health services utilization during the XVII Central American and Caribbean Sport Games: Delegation of Puerto Rico, Ponce 1993].

    PubMed

    Aguirre, G; Frontera, W R; Colón, L R; Amy, E; Micheo, W; Correa, J J; Camuñas, J F

    1994-12-01

    During the XVII Central American and Caribbean Sports Games held in Ponce in 1993 the health services offered to the Puerto Rico Delegation included medical, dental and psychological assistance, physical therapy and services on the playing field. Information about the use of these services was obtained from the encounter sheets. The Puerto Rican delegation of 750 members had 1,800 encounters with the health team; 612 (34.0%) individual consults; 896 (54.8%) physical therapy sessions; 166 (9.2%) encounters in the sports venues; and 36 (20%) group therapies. The most common diagnoses were athletic injuries (304; 58.2%) and diseases of the respiratory system (76; 14.5%). The most frequent athletic injuries were first degree strains (75; 24.7%) and tendinitis (73, 24.0%). This pattern is similar to that observed in other sports games and delegations with mild conditions prevailing. An interdisciplinary work and biopsychosocial approach will be important for the better health and performance of our athletes.

  1. Health impact of water and sanitation infrastructure reconstruction programmes in eight Central American communities affected by Hurricane Mitch.

    PubMed

    Moll, Deborah M; McElroy, Rebecca H; Sabogal, Raquel; Corrales, Lana F; Gelting, Richard J

    2007-03-01

    In response to Hurricane Mitch, which struck Central America in October-November 1998, the American Red Cross (ARC) and the Centers for Disease Control and Prevention (CDC) collaborated on a 3-year evaluation of the public health impact of ARC's water, sanitation and hygiene education activities in eight study areas in Honduras, Nicaragua, El Salvador and Guatemala. The evaluation compared: 1) access to and use of water and sanitation facilities, 2) the use of hygienic behaviours, and 3) diarrhoeal prevalence in children younger than 3 years of age before (February 2000) and after (February 2002) the interventions had been implemented. The evaluation included household and key informant interviews designed to measure these three components. Water quality of community water sources and household water was evaluated by measuring levels of indicator bacteria. During the final survey, an infrastructure evaluation provided a review of the design, construction, and current operation and maintenance of the water systems and latrines. The integrated water and sanitation infrastructure interventions and hygiene education programmes implemented following Hurricane Mitch effectively decreased diarrhoea prevalence in the target communities.

  2. Individual Pheromone Signature in Males: Prerequisite for Pheromone-Mediated Mate Assessment in the Central American Locust, Schistocerca Piceifrons.

    PubMed

    Stahr, Christiane; Seidelmann, Karsten

    2016-12-01

    Living in high-density groups of animals has advantages and disadvantages for mating. The advantage of facilitated mate finding is compromised by difficulties in protecting a suitable partner from competitors. Thus, males regularly are faced with increased competition for sperm, and females with harassment by males at high population densities. To cope with these problems, mating tactics and mate choice mechanisms have to be adjusted. An adaptation to gregarious condition observed in locusts includes the use of male-emitted pheromones. Males of the Central American locust, Schistocerca piceifrons, release sex-specific volatiles, which were identified as phenethyl alcohol (synonym: phenyl-ethyl-alcohol, 2-phenyl-1-ethanol, 2-phenylethanol, PEA), (Z)-3-nonen-1-ol (3-Nol), and (Z)-2-octen-1-ol (2-Ool). The emission of the two major compounds, PEA and 3-Nol, was restricted to crowded conditions. Furthermore, the release of both volatiles was coupled to males reaching sexual maturity, indicating a function in reproductive behavior. However, neither the single substances nor their mixtures were attractive or repellent to the locusts. Instead, females prefer the sperm of high pheromone-emitting males to fertilize their ova. In this way, the male-specific volatiles act as mate assessment pheromones utilized in a context of cryptic female choice. This function is well supported by the highly variable but individual-specific emission rates of the three compounds. Schistocerca piceifrons males release a virtually unique personal pheromone signature, a prerequisite for mate assessment pheromones.

  3. [Menarche, menstrual and sociodemographic characteristics of Puerto Rican female athletes in the XV and XVI Central American and Caribbean Games].

    PubMed

    Rivera, M A; Mendez Zamora, I; Matos, R M; Rivera, A

    1993-09-01

    This investigation described maturation, menstrual and socio-demographic characteristics of 65 Puerto Rican women athletes that were interviewed during the XVI Central American and Caribbean Games (CACG), Mexico City in 1990. The results were compared with those of Puerto Rican women athletes (n = 52) at the XV CACG, Santiago Dominican Republic, 1986. The quantitative variables (age, age at initiation of training, years of training, age at menarche, birth order, and family size) were not statistically different (t-independent, p > or = 0.05). The observed frequencies for the qualitative variables (menstrual characteristics, degree of certainty in the recall of age of menarche, use of oral contraceptives, and marital status) were very similar. the women at the XVI CAC in Mexico demonstrated similar maturational, menstrual and socio-demographic characteristics to the those athletes evaluated four years earlier in Santiago and based on their long history of training, both samples were representative of athletically mature athletes. The findings were very similar to those reported for olympic athletes and such data expands the available information on Puerto Rican women athletes.

  4. A Terrestrial Reference Frame (TRF), coordinates and velocities for South American stations: contributions to Central Andes geodynamics

    NASA Astrophysics Data System (ADS)

    Mackern, M. V.; Mateo, M. L.; Robin, A. M.; Calori, A. V.

    2009-12-01

    Satellite positioning systems allow the fixing of the location of a point on the Earth's surface with very good precision and accuracy. To do this, however, it is necessary to determine the point coordinates taking account the reference system and the movements that affect them because of tectonic plate movements. These reference systems are materialized by a significant number of continuous measurement stations in South America. In SIRGAS (Sistema de Referencia Geocéntrico para las Américas), there are four Analysis Centers that process the data collected from satellites of the Global Navigation Satellite Systems (GNSS), with the primary purpose to maintain the international terrestrial reference frame through calculation of the coordinates and velocities of the continuous GNSS stations of the SIRGAS-CON Network. In this work, we demonstrate the quality of the solutions from CIMA, one of the SIRGAS official processing centers operating in Mendoza, Argentina, in comparison with other South American processing centers. The importance of precise calculations of coordinates and velocities in a global frame is also shown. Finally, we give estimations of velocities from stations located within deformation zones in the Central Andes.

  5. Lowermost Mantle Velocity Estimations Beneath the Central North Atlantic Area from Pdif Observed at Balkan, East Mediterranean, and American Stations

    NASA Astrophysics Data System (ADS)

    Ivan, Marian; Ghica, Daniela Veronica; Gosar, Andrej; Hatzidimitriou, Panagiotis; Hofstetter, Rami; Polat, Gulten; Wang, Rongjiang

    2015-02-01

    Lowermost mantle velocity in the area 15°S-70°N latitude/60°W-5° W longitude is estimated using two groups of observations, complementary to each other. There are 894 Pdif observations at stations in the Balkan and Eastern Mediterranean areas from 15 major earthquakes in Central and South America. Another 218 Pdif observations are associated with four earthquakes in Greece/Turkey and one event in Africa, recorded by American stations. A Pdif slowness tomographic approach of the structures immediately above the core-to-mantle boundary (CMB) is used, incorporating corrections for ellipticity, station elevation and velocity perturbations along the ray path. A low-velocity zone above CMB with a large geographical extent, approximately in the area (35-65°N) × (40-20°W), appears to have the velocity perturbations exceeding the value actually assumed by some global models. Most likely, it is extended beneath western Africa. A high-velocity area is observed west of the low-velocity zone. The results suggest that both Cape Verde and Azorean islands are located near transition areas from low-to-high velocity values in the lowermost mantle.

  6. Early Miocene chondrichthyans from the Culebra Formation, Panama: A window into marine vertebrate faunas before closure the Central American Seaway

    NASA Astrophysics Data System (ADS)

    Pimiento, Catalina; Gonzalez-Barba, Gerardo; Hendy, Austin J. W.; Jaramillo, Carlos; MacFadden, Bruce J.; Montes, Camilo; Suarez, Sandra C.; Shippritt, Monica

    2013-03-01

    The newly described chondrichthyan fauna of the early Miocene Culebra Formation of Panama provides insight into the marine vertebrates occupying shallow seas adjacent to the Central American Seaway, prior to the rise of the Isthmus of Panama. This study takes advantage of a time-limited and unique opportunity to recover fossil from renewed excavations of the Panama Canal. The chondrichthyan fauna of the Culebra Formation is composed of teeth and vertebral centra representing 12 taxa. The species found possessed a cosmopolitan tropical and warm-temperate distribution during the early Neogene and are similar to other assemblages of the tropical eastern Pacific and southern Caribbean. The taxa described suggest a neritic environment, and is in contrast with other interpretations that proposed bathyal water depths for the upper member of the Culebra Formation. The wide depth range of the most common species, Carcharocles chubutensis, and the habitat preference of Pristis sp., suggests varied marine environments, from deep, to shallow waters, close to emerged areas of the evolving isthmus.

  7. Molecular characterization of a region of DNA associated with mutations at the agouti locus in the mouse.

    PubMed

    Bultman, S J; Russell, L B; Gutierrez-Espeleta, G A; Woychik, R P

    1991-09-15

    Molecular characterization of a radiation-induced agouti (a)-locus mutation has resulted in the isolation of a segment of DNA that maps at or near the a locus on chromosome 2 in the mouse. This region of DNA is deleted in several radiation- or chemical-induced homozygous-lethal a-locus mutations and is associated with specific DNA structural alterations in two viable a-locus mutations. We propose that DNA probes from this region of chromosome 2 will be useful for ultimately characterizing the individual gene or genes associated with a-locus function.

  8. Real time earthquake information and tsunami estimation system for Indonesia, Philippines and Central-South American regions

    NASA Astrophysics Data System (ADS)

    Pulido Hernandez, N. E.; Inazu, D.; Saito, T.; Senda, J.; Fukuyama, E.; Kumagai, H.

    2015-12-01

    Southeast Asia as well as Central-South American regions are within the most active seismic regions in the world. To contribute to the understanding of source process of earthquakes the National Research Institute for Earth Science and Disaster Prevention NIED maintains the international seismic Network (ISN) since 2007. Continuous seismic waveforms from 294 broadband seismic stations in Indonesia, Philippines, and Central-South America regions are received in real time at NIED, and used for automatic location of seismic events. Using these data we perform automatic and manual estimation of moment tensor of seismic events (Mw>4.5) by using the SWIFT program developed at NIED. We simulate the propagation of local tsunamis in these regions using a tsunami simulation code and visualization system developed at NIED, combined with CMT parameters estimated by SWIFT. The goals of the system are to provide a rapid and reliable earthquake and tsunami information in particular for large seismic, and produce an appropriate database of earthquake source parameters and tsunami simulations for research. The system uses the hypocenter location and magnitude of earthquakes automatically determined at NIED by the SeisComP3 system (GFZ) from the continuous seismic waveforms in the region, to perform the automated calculation of moment tensors by SWIFT, and then carry out the automatic simulation and visualization of tsunami. The system generates maps of maximum tsunami heights within the target regions and along the coasts and display them with the fault model parameters used for tsunami simulations. Tsunami calculations are performed for all events with available automatic SWIFT/CMT solutions. Tsunami calculations are re-computed using SWIFT manual solutions for events with Mw>5.5 and centroid depths shallower than 100 km. Revised maximum tsunami heights as well as animation of tsunami propagation are also calculated and displayed for the two double couple solutions by SWIFT

  9. Structure-Activity Relationship Studies on a Macrocyclic Agouti-Related Protein (AGRP) Scaffold Reveal Agouti Signaling Protein (ASP) Residue Substitutions Maintain Melanocortin-4 Receptor Antagonist Potency and Result in Inverse Agonist Pharmacology at the Melanocortin-5 Receptor.

    PubMed

    Ericson, Mark D; Freeman, Katie T; Schnell, Sathya M; Fleming, Katlyn A; Haskell-Luevano, Carrie

    2017-10-04

    The melanocortin system consists of five reported receptors, agonists from the proopiomelanocortin gene transcript, and two antagonists, agouti-signaling protein (ASP) and agouti-related protein (AGRP). For both ASP and AGRP, the hypothesized Arg-Phe-Phe pharmacophores are on exposed β-hairpin loops. In this study, the Asn and Ala positions of a reported AGRP macrocyclic scaffold (c[Pro-Arg-Phe-Phe-Asn-Ala-Phe-DPro]) were explored with 14-compound and 8-compound libraries, respectively, to generate more potent, selective melanocortin receptor antagonists. Substituting diaminopropionic acid (Dap), DDap, and His at the Asn position yielded potent MC4R ligands, while replacing Ala with Ser maintained MC4R potency. Since these substitutions correlate to ASP loop residues, an additional Phe to Ala substitution was synthesized and observed to maintain MC4R potency. Seventeen compounds also possessed inverse agonist activity at the MC5R, the first report of this pharmacology. These findings are useful in developing molecular probes to study negative energy balance conditions and unidentified functions of the MC5R.

  10. Migration and wintering areas of American Bitterns (Botaurus lentiginosus) that summer in central North America as determined by satellite and radio telemetry, 1998-2003

    USGS Publications Warehouse

    Huschle, Guy; Toepfer, John E.; Douglas, David C.

    2013-01-01

    Twenty adult male American Bitterns (Botaurus lentiginosus) were marked on summer range in central North America with satellite tracking Platform Transmitter Terminals (PTTs) to document migration routes and wintering range. Nineteen complete fall migration routes were documented for 17 individuals. Of the successful migrations, 63% (n = 12) went to southern Florida, 32% (n = 6) to southern Louisiana, and 5% (n = 1) to the Gulf coast of Texas. Spring migrations for nine birds were documented, and 78% (n = 7) showed fidelity to breeding range. Two complete migrations for two individuals were documented, and they demonstrated fidelity to winter range. The longest, fastest movement documented was 2,300 km in less than 74 hr. Extensive, post-breeding dispersal was not observed in the adult male American Bitterns in this study. Six male American Bitterns were marked with PTTs on winter range in Florida and Texas. Spring migration for these birds was documented to Nebraska, North Dakota, Saskatchewan, Manitoba and Ontario. Sixty-seven American Bitterns were marked with Very High Frequency radio transmitters on summer ranges, and 16% (n = 11) were located on wintering grounds used by the satellite-tracked birds, further documenting the importance of the Everglades and the Louisiana coast as winter habitat for American Bitterns that breed in Central North America.

  11. Continental climate gradients in North America and Western Eurasia before and after the closure of the Central American Seaway

    NASA Astrophysics Data System (ADS)

    Utescher, Torsten; Dreist, Andreas; Henrot, Alexandra-Jane; Hickler, Thomas; Liu, Yu-Sheng (Christopher); Mosbrugger, Volker; Portmann, Felix T.; Salzmann, Ulrich

    2017-08-01

    The Gulf Stream, as part of the Atlantic Meridional Overturning Circulation (AMOC), is known as a major driver of latitudinal energy transport in the North Atlantic presently causing mild winters over northwestern Eurasia. The intensity of the AMOC throughout the Neogene, prior to the final closure of the Central American Seaway (CAS) in the early Pliocene, is still poorly known, but most authors assume that the circulation was considerably weaker than present. Here we address this issue from a continental point of view. We studied the past AMOC intensity by analyzing Neogene continental climate patterns along North American and Western Eurasian transects. Based on a total of 317 palaeofloras thermal latitudinal gradients are reconstructed for three Neogene time slices, namely the middle Miocene, late Miocene, and late Pliocene using the Coexistence Approach to obtain quantitative climate data. The obtained proxy-based, continental temperature gradients are evaluated against data from a selection of published General Circulation Model (GCM) simulations for the three time slices studied. Our study suggests that shallow thermal latitudinal gradients existed in North America and Western Eurasia throughout the Miocene but became strongly steepened in the late Pliocene. In both Miocene time slices studied, the higher latitudes were by up to 30 °C warmer than present (cold month mean), also at times with presumed pre-industrial CO2 such as the late Miocene. In the late Pliocene high-latitude, the temperature difference with respect to the present had decreased by up to 10 °C (cold month mean). Both mean annual temperatures and cold month means of the lower mid and low latitudes were at the present-day level throughout all three time slices, or even slightly below. In both Miocene time slices, zonal temperature means at both continental transects were similar in the mid and higher latitudes. However, several northwest European sites reveal very mild winter condition

  12. Central American Climatology

    DTIC Science & Technology

    1985-04-01

    8 3.1 Precipitation ..................................................................... . 8 3.2 Psychrometrics...26 A-7 Mean Monthly Temperature, November ..................................................... 27A- 8 Percent Frequency of Occurrence, Ceilings...80 ’. B- 8 Days with Thunderstorms .................................. ...................... 83 B-9

  13. Effect of Aerosols on Surface Radiation and Air Quality in the Central American Region Estimated Using Satellite UV Instruments

    NASA Astrophysics Data System (ADS)

    Bhartia, P. K.; Torres, O.; Krotkov, N. A.

    2007-05-01

    Solar radiation reaching the Earth's surface is reduced by both aerosol scattering and aerosol absorption. Over many parts of the world the latter effect can be as large or larger than the former effect, and small changes in the aerosol single scattering albedo can either cancel the former effect or enhance it. In addition, absorbing aerosols embedded in clouds can greatly reduce the amount of radiation reaching the surface by multiple scattering. Though the potential climatic effects of absorbing aerosols have received considerable attention lately, their effect on surface UV, photosynthesis, and photochemistry can be equally important for our environment and may affect human health and agricultural productivity. Absorption of all aerosols commonly found in the Earth's atmosphere becomes larger in the UV and blue wavelengths and has a relatively strong wavelength dependence. This is particularly true of mineral dust and organic aerosols. However, these effects have been very difficult to estimate on a global basis since the satellite instruments that operate in the visible are primarily sensitive to aerosol scattering. A notable exception is the UV Aerosol Index (AI), first produced using NASA's Nimbus-7 TOMS data. AI provides a direct measure of the effect of aerosol absorption on the backscattered UV radiation in both clear and cloudy conditions, as well as over snow/ice. Although many types of aerosols produce a distinct color cast in the visible images, and aerosols absorption over clouds and snow/ice could, in principle be detected from their color, so far this technique has worked well only in the UV. In this talk we will discuss what we have learned from the long-term record of AI produced from TOMS and Aura/OMI about the possible role of aerosols on surface radiation and air quality in the Central American region.

  14. Evaluation of Central North American prairie management based on species diversity, life form, and individual species metrics.

    PubMed

    Brudvig, Lars A; Mabry, Catherine M; Miller, James R; Walker, Tracy A

    2007-06-01

    Reintroduction of fire and grazing, alone or in combination, has increasingly been recognized as central to the restoration of North American mixed-grass and tallgrass prairies. Although ecological studies of these systems are abundant, they have generally been observational, or if experimental, have focused on plant species diversity. Species diversity measures alone are not sufficient to inform management, which often has goals associated with life-form groups and individual species. We examined the effects of prescribed fire, light cattle grazing, and a combination of fire and grazing on three vegetation components: species diversity, groups of species categorized by life-form, and individual species. We evaluated how successful these three treatments were in achieving specific management goals for prairies in the Iowa Loess Hills (U.S.A.). The grazing treatment promoted the greatest overall species richness, whereas grazing and burning and grazing treatments resulted in the lowest cover by woody species. Burning alone best achieved the management goals of increasing the cover and diversity of native species and reducing exotic forb and (predominantly exotic) cool-season grass cover. Species-specific responses to treatments appeared idiosyncratic (i.e., within each treatment there existed a set of species attaining their highest frequency) and nearly half of uncommon species were present in only one treatment. Because all management goals were not achieved by any one treatment, we conclude that management in this region may need refining. We suggest that a mosaic of burning and grazing (alone and in combination) may provide the greatest landscape-level species richness; however, this strategy would also likely promote the persistence of exotic species. Our results support the need to consider multiple measures, including species-specific responses, when planning and evaluating management.

  15. Influence of the Central American Seaway and Drake Passage on ocean circulation and neodymium isotopes: A model study

    NASA Astrophysics Data System (ADS)

    Pfister, Patrik L.; Stocker, Thomas F.; Rempfer, Johannes; Ritz, Stefan P.

    2014-12-01

    The sensitivity of the neodymium isotopic composition (ɛNd) to tectonic rearrangements of seaways is investigated using an Earth System Model of Intermediate Complexity. The shoaling and closure of the Central American Seaway (CAS) is simulated, as well as the opening and deepening of Drake Passage (DP). Multiple series of equilibrium simulations with various intermediate depths are performed for both seaways, providing insight into ɛNd and circulation responses to progressive throughflow evolutions. Furthermore, the sensitivity of these responses to the Atlantic Meridional Overturning Circulation (AMOC) and the neodymium boundary source is examined. Modeled ɛNd changes are compared to sediment core and ferromanganese (Fe-Mn) crust data. The model results indicate that the North Atlantic ɛNd response to the CAS shoaling is highly dependent on the AMOC state, i.e., on the AMOC strength before the shoaling to shallow depths (preclosure). Three scenarios based on different AMOC forcings are discussed, of which the model-data agreement favors a shallow preclosure (Miocene) AMOC (˜6 Sv). The DP opening causes a rather complex circulation response, resulting in an initial South Atlantic ɛNd decrease preceding a larger increase. This feature may be specific to our model setup, which induces a vigorous CAS throughflow that is strongly anticorrelated to the DP throughflow. In freshwater experiments following the DP deepening, ODP Site 1090 is mainly influenced by AMOC and DP throughflow changes, while ODP Site 689 is more strongly influenced by Southern Ocean Meridional Overturning Circulation and CAS throughflow changes. The boundary source uncertainty is largest for shallow seaways and at shallow sites.

  16. North American Amphibian Monitoring Program (NAAMP) anuran detection data from the eastern and central United States (1994-2015)

    USGS Publications Warehouse

    Foreman, Tasha M.; Grant, Evan H. Campbell; Weir, Linda A.

    2017-01-01

    The North American Amphibian Monitoring Program (NAAMP) was a collaborative citizen science effort between the US Geological Survey (USGS) and 26 Partners (state agencies, universities, and nonprofits) for monitoring calling amphibian populations over much of the eastern and central United States. Initiated in 1997 in response to needs set forth by the Declining Amphibian Populations Task Force in 1994 regarding increased anecdotal observations of global amphibian declines, NAAMP was designed to provide scientifically and statistically defensible, long-term distribution and trends data for calling amphibian populations at the state and regional level in the United States. The USGS discontinued coordination of the program at the conclusion of the 2015 field season. Modeled after the USGS Breeding Bird Survey, NAAMP used a network of random and state-requested non-random roadside routes with listening stops near wetlands to collect frog and toad occupancy and environmental data in predominantly unprotected lands. Data collection and verification under a unified protocol began in 2001 and continued through 2015 with the addition of observer assessment scores in 2006. The USGS utilized verified 2001-2015 data from random routes to produce occupancy trend reports for anuran species of the Northeast, Southeast, and Midwest regions and states of the United States. This dataset includes all raw, verified NAAMP data from 1997 through 2015 and also raw, verified data from Partner States that precede the program (1994-1996). Data preceding 2001 followed variations of the unified protocol. Please refer to metadata for additional information regarding protocol and a list of the represented states and see the Species.csv file for the list of 58 represented species.

  17. Contrasting demographic history and gene flow patterns of two mangrove species on either side of the Central American Isthmus.

    PubMed

    Cerón-Souza, Ivania; Gonzalez, Elena G; Schwarzbach, Andrea E; Salas-Leiva, Dayana E; Rivera-Ocasio, Elsie; Toro-Perea, Nelson; Bermingham, Eldredge; McMillan, W Owen

    2015-08-01

    Comparative phylogeography offers a unique opportunity to understand the interplay between past environmental events and life-history traits on diversification of unrelated but co-distributed species. Here, we examined the effects of the quaternary climate fluctuations and palaeomarine currents and present-day marine currents on the extant patterns of genetic diversity in the two most conspicuous mangrove species of the Neotropics. The black (Avicennia germinans, Avicenniaceae) and the red (Rhizophora mangle, Rhizophoraceae) mangroves have similar geographic ranges but are very distantly related and show striking differences on their life-history traits. We sampled 18 Atlantic and 26 Pacific locations for A. germinans (N = 292) and R. mangle (N = 422). We performed coalescence simulations using microsatellite diversity to test for evidence of population change associated with quaternary climate fluctuations. In addition, we examined whether patterns of genetic variation were consistent with the directions of major marine (historical and present day) currents in the region. Our demographic analysis was grounded within a phylogeographic framework provided by the sequence analysis of two chloroplasts and one flanking microsatellite region in a subsample of individuals. The two mangrove species shared similar biogeographic histories including: (1) strong genetic breaks between Atlantic and Pacific ocean basins associated with the final closure of the Central American Isthmus (CAI), (2) evidence for simultaneous population declines between the mid-Pleistocene and early Holocene, (3) asymmetric historical migration with higher gene flow from the Atlantic to the Pacific oceans following the direction of the palaeomarine current, and (4) contemporary gene flow between West Africa and South America following the major Atlantic Ocean currents. Despite the remarkable differences in life-history traits of mangrove species, which should have had a strong influence on seed

  18. Contrasting demographic history and gene flow patterns of two mangrove species on either side of the Central American Isthmus

    PubMed Central

    Cerón-Souza, Ivania; Gonzalez, Elena G; Schwarzbach, Andrea E; Salas-Leiva, Dayana E; Rivera-Ocasio, Elsie; Toro-Perea, Nelson; Bermingham, Eldredge; McMillan, W Owen

    2015-01-01

    Comparative phylogeography offers a unique opportunity to understand the interplay between past environmental events and life-history traits on diversification of unrelated but co-distributed species. Here, we examined the effects of the quaternary climate fluctuations and palaeomarine currents and present-day marine currents on the extant patterns of genetic diversity in the two most conspicuous mangrove species of the Neotropics. The black (Avicennia germinans, Avicenniaceae) and the red (Rhizophora mangle, Rhizophoraceae) mangroves have similar geographic ranges but are very distantly related and show striking differences on their life-history traits. We sampled 18 Atlantic and 26 Pacific locations for A. germinans (N = 292) and R. mangle (N = 422). We performed coalescence simulations using microsatellite diversity to test for evidence of population change associated with quaternary climate fluctuations. In addition, we examined whether patterns of genetic variation were consistent with the directions of major marine (historical and present day) currents in the region. Our demographic analysis was grounded within a phylogeographic framework provided by the sequence analysis of two chloroplasts and one flanking microsatellite region in a subsample of individuals. The two mangrove species shared similar biogeographic histories including: (1) strong genetic breaks between Atlantic and Pacific ocean basins associated with the final closure of the Central American Isthmus (CAI), (2) evidence for simultaneous population declines between the mid-Pleistocene and early Holocene, (3) asymmetric historical migration with higher gene flow from the Atlantic to the Pacific oceans following the direction of the palaeomarine current, and (4) contemporary gene flow between West Africa and South America following the major Atlantic Ocean currents. Despite the remarkable differences in life-history traits of mangrove species, which should have had a strong influence on seed

  19. [Central American seminars for young psychiatrists of the region and training of leaders in community mental health. Sweden/PAHO-WHO collaboration program].

    PubMed

    Penayo, U; Kullgrèn, G; Jacobsson, L

    1994-09-01

    The Swedish Psychiatric Association, in collaboration with the Department of Psychiatry, University of Umeå, Sweden, and the Pan American Health Organization/WHO, has obtained economic support from the Swedish Agency for International Development (ASDI), to organize training seminars for young psychiatrists from Central America. The program will continue until 1995 with an option to pursue further studies leading to a master or other post-graduate degrees. The overall purpose is to strengthen the knowledge in epidemiology and community mental health, along the lines set by the "Caracas Declaration" of a cadre of young leaders in the field of psychiatry in Central America.

  20. The Humorous Oral Folktale in West Central Georgia: Implications for Its Use in the Secondary School American Literature Program.

    ERIC Educational Resources Information Center

    Colmant, Berta Boyce

    The thesis of this study is that the secondary school American literature curriculum in a particular region should include the cultural heritage of that region as reflected in its oral literature. In this study, aspects of the growth of a distinctive American humor are traced from colonial times to the present along the eastern seaboard, with…

  1. The Central Nervous System and Alcohol Use. Science of Alcohol Curriculum for American Indians. Training Unit [and] Participant Booklet.

    ERIC Educational Resources Information Center

    Jacobs, Cecelia; And Others

    The Science of Alcohol Curriculum for American Indians uses the Medicine Circle and the "new science paradigm" to study the science of alcohol through a culturally relevant holistic approach. Intended for teachers and other educational personnel involved with American Indians, this curriculum aims to present a framework for alcohol…

  2. Paleocene Turbidite Deposition in the Central American Seaway (NW Costa Rica): Geochemical Analysis and Provenance of Detrital Spinel and Clinopyroxene

    NASA Astrophysics Data System (ADS)

    Giblin, A. C.

    2015-12-01

    The Central American Land Bridge is the crucial connection between North and South America, and the Miocene closure of the Panama seaway led to a change in global oceanic circulation patterns. Modern Costa Rica is part of the island arc that formed over the western Caribbean subduction zone, and the Santa Elena peninsula is on the northwest coast of Costa Rica next to the Sandino forearc basin. This study focuses on the origin and provenance of the Paleocene deep-water Rivas and Descartes turbidites that crop out on the northern part of the Santa Elena peninsula in northwestern Costa Rica. Understanding the sedimentary fill of the Sandino Basin that contributed to the closing of the seaway may lead to a better understanding of the Late Cretaceous-Paleogene arcs. Provenance studies of the Santa Elena Peninsula turbidite sandstone bodies constrain the history of the paleogeography and tectonics of the region. Petrographic analyses of rock thin sections constrain source areas; geochemical analysis of individual detrital heavy minerals from rock samples give indications of sediment sources and tectonic setting during deposition. This study is a provenance analysis based on (i) semi-quantitative energy-dispersive spectrometry analysis of heavy minerals, (ii) quantitative wavelength-dispersive spectrometry for major elements of detrital clinopyroxene and spinel grains, (iii) trace element analysis through laser ablation of single detrital clinopyroxene grains, and (iv) comparative analysis of the different potential source rocks to clearly identify the most likely sediment sources. The detrital spinel and clinopyroxene are possibly sourced from: mantle ophiolites, mid-ocean ridge gabbros, or volcanic arc tholeiitic basalts or calc-alkaline andesites. Spinel and clinopyroxne geochemistry suggests a possible peridotitic source, linked to mantle rocks that are now covered by Tertiary volcanics or have completely eroded. The character of the crustal minerals indicates

  3. Open-Vent Degassing of CO2 from Typical Andesitic Volcanoes in the Central American Volcanic Arc

    NASA Astrophysics Data System (ADS)

    Robidoux, P.; Aiuppa, A.; Rotolo, S.; Giudice, G.; Moretti, R.; Conde, V.; Galle, B.; Tamburello, G.

    2014-12-01

    The collection of H2O-CO2-SO2 volcanic gas datasets at open-vent basaltic volcanoes has increased since the introduction of electrochemical/NDIR (Multi-GAS) instruments in the field. An open problem remains to understand the degassing regime of volcanoes of intermediate compositions, which is complicated by wide range of eruption styles. We propose here to initiate the study of the degassing regime of Telica and San Cristobal (Nicaragua), two constantly monitored volcanoes in the Central American Volcanic Arc (CAVA). We calculated the CO2 flux sustained by summit plume degassing at Telica and San Cristobal as the product of the CO2/SO2 ratio of Multi-GAS technique with parallel SO2 flux measurements, made by using scanning UV-DOAS instruments in 2013. At Telica, the CO2 flux was evaluated at 166±76 t/d and at San Cristobal we measured 520±260 t/d. Degassing activity at Telica volcano consists in surface gas discharges dominated by H2O (70-98 mol%; mean of 92 mol%), and by CO2 (1-23 mol%; mean of 6 mol%) and SO2 (0.5-7.4 mol%; mean of 2.9 mol%). San Cristobal gas is dominated by H2O (85-97 mol%; mean of 92 mol%), and by CO2 (2-12 mol%; mean of 6 mol%) and SO2 (3-5 mol%; mean of 3.8 mol%). These values are typical of volcanic arc regions and the volcanoes were in a stage of quiescent degassing without excess of CO2 output relatively to the other major gases. By interpreting our recent gas measurements in tandem with preliminary melt inclusion records of pre-eruptive dissolved volatile abundances, we hope to build a conceptual degassing model taking into account the active degassing regimes during past volcanic eruptions. Finally, we hope to refine the CO2 budget estimates along the CAVA.

  4. Epizootic vacuolar myelinopathy of the central nervous system of bald eagles (Haliaeetus leucocephalus) and American coots (Fulica americana).

    PubMed

    Thomas, N J; Meteyer, C U; Sileo, L

    1998-11-01

    Unprecedented mortality occurred in bald eagles (Haliaeetus leucocephalus) at DeGray Lake, Arkansas, during the winters of 1994-1995 and 1996-1997. The first eagles were found dead during November, soon after arrival from fall migration, and deaths continued into January during both episodes. In total, 29 eagles died at or near DeGray Lake in the winter of 1994-1995 and 26 died in the winter of 1996-1997; no eagle mortality was noted during the same months of the intervening winter or in the earlier history of the lake. During the mortality events, sick eagles were observed overflying perches or colliding with rock walls. Signs of incoordination and limb paresis were also observed in American coots (Fulica americana) during the episodes of eagle mortality, but mortality in coots was minimal. No consistent abnormalities were seen on gross necropsy of either species. No microscopic findings in organs other than the central nervous system (CNS) could explain the cause of death. By light microscopy, all 26 eagles examined and 62/77 (81%) coots had striking, diffuse, spongy degeneration of the white matter of the CNS. Vacuolation occurred in all myelinated CNS tissue, including the cerebellar folia and medulla oblongata, but was most prominent in the optic tectum. In the spinal cord, vacuoles were concentrated near the gray matter, and occasional swollen axons were seen. Vacuoles were uniformly present in optic nerves but were not evident in the retina or peripheral or autonomic nerves. Cellular inflammatory response to the lesion was distinctly lacking. Vacuoles were 8-50 microns in diameter and occurred individually, in clusters, or in rows. In sections stained by luxol fast blue/periodic acid-Schiff stain, the vacuoles were delimited and transected by myelin strands. Transmission electron microscopy revealed intramyelinic vacuoles formed in the myelin sheaths by splitting of one or more myelin lamellae at the intraperiodic line. This lesion is characteristic of

  5. Late Pleistocene/Holocene paleoclimate reconstruction and eruptive history of Central American volcanoes from lake bottom sediments of Lake Nicaragua

    NASA Astrophysics Data System (ADS)

    Wulf, S.; Dull, R. A.; Mann, P.; McIntosh, K. D.; Gardner, J. E.

    2007-12-01

    A shallow coring program in Lake Nicaragua was completed in May/June 2006 by the University of Texas (UT Department of Geography and UT Institute for Geophysics). A total of 35 sediment cores with lengths ranging between 12 cm and 100 cm along with five longer cores were extracted from the lake using a gravity corer and a modified manual square rod piston corer, respectively. Analyses of lake sediments have the following objectives: 1) to correlate the geophysical results with the core data to provide a stratigraphic framework for the shallow lake sediments; 2) to constrain past climate variability in this rather poorly investigated area; and 3) to establish a time series of explosive volcanic activity based on the identification and dating of tephra layers in the cores. Initial measurements of magnetic susceptibility, dry density, loss on ignition and XRF scanning indicated a dominance of fine-grained homogeneous diatomaceous sediments cover most of the lake floor. Increasing values in magnetic susceptibility in the upper part of several short cores most likely reflect increased erosion caused by land-use changes during the Spanish colonial period (1522-1822). Results on the two longest cores from the northeastern (355 cm) and southwestern (478 cm) parts of the lake reveal complete Holocene paleoclimate records in both areas that are comparable to other terrestrial and marine records in the Central and South- American tropics (i.e. Cariaco Basin). A lithologic change from homogeneous gyttia (diatomaceous mud) to blue- grayish waxy clay at the bottom of these records marks the Late Pleistocene-Holocene transition as indicated by a radiocarbon dating on plant remains. The latter dense clay forms a distinctive stratigraphic marker in the lake basin. Tephra layers to date were detected in most gravity cores recovered west of Ometepe Island (Volcan Concepcion), and in long records in the northeastern basin (San Antonio Tephra, Masaya volcano, ca. 7,400 interpolated cal

  6. Therapies for macular edema associated with central retinal vein occlusion: a report by the American Academy of Ophthalmology.

    PubMed

    Yeh, Steven; Kim, Stephen J; Ho, Allen C; Schoenberger, Scott D; Bakri, Sophie J; Ehlers, Justis P; Thorne, Jennifer E

    2015-04-01

    To review the available evidence regarding the safety and efficacy of therapies for the treatment of macular edema (ME) associated with central retinal vein occlusion (CRVO). A literature search of the PubMed database was last conducted in March 2014 with no date restrictions but limited to articles published in English. A literature search of the Cochrane Library was also conducted in March 2014 with no date restrictions and without a language limitation. The combined searches yielded 108 citations, of which 20 were deemed clinically relevant for the Ophthalmic Technology Assessment Committee Retina/Vitreous panel to review in full text. Three additional studies were also identified for panel review. The level of evidence of these selected studies was reviewed by the panel methodologist. There were 7 citations representing 4 clinical trials that provided level I evidence supporting the use of anti-vascular endothelial growth factor (VEGF) pharmacotherapies for ME associated with CRVO, including intravitreal ranibizumab (2), aflibercept (3), and bevacizumab (2). There were 3 citations representing 2 studies with level I evidence for intravitreal corticosteroid injection with dexamethasone intravitreal implant (2 citations) or triamcinolone (1 citation), although cataract and glaucoma were observed in these studies. Level I evidence is available on the limited benefit of macular grid-pattern laser photocoagulation (1 citation). Eight other citations reviewed were rated as level II, and 4 citations were rated as level III. Long-term efficacy results (≥2 years of follow-up) are limited to intravitreal ranibizumab at this time, and few studies have evaluated combination therapy with anti-VEGF and corticosteroid versus monotherapy of either class of drug. Level I evidence indicates that intravitreal anti-VEGF pharmacotherapy is safe and effective over 2 years for ME associated with CRVO and that delay in treatment is associated with worse visual outcomes. In addition

  7. Epizootic vacuolar myelinopathy of the central nervous system of bald eagles (Haliaeetus leucocephalus) and American coots (Fulica americana)

    USGS Publications Warehouse

    Thomas, N.J.; Meteyer, C.U.; Sileo, L.

    1998-01-01

    Unprecedented mortality occurred in bald eagles (Haliaeetus leucocephalus) at DeGray Lake, Arkansas, during the winters of 1994-1995 and 1996-1997. The first eagles were found dead during November, soon after arrival from fall migration, and deaths continued into January during both episodes. In total, 29 eagles died at or near DeGray Lake in the winter of 1994-1995 and 26 died in the winter of 1996-1997; no eagle mortality was noted during the same months of the intervening winter or in the earlier history of the lake. During the mortality events, sick eagles were observed overflying perches or colliding with rock walls. Signs of incoordination and limb paresis were also observed in American coots (Fulica americana) during the episodes of eagle mortality, but mortality in coots was minimal. No consistent abnormalities were seen on gross necropsy of either species. No microscopic findings in organs other than the central nervous system (CNS) could explain the cause of death. By light microscopy, all 26 eagles examined and 62/77 (81%) coots had striking, diffuse, spongy degeneration of the white matter of the CNS. Vacuolation occurred in all myelinated CNS tissue, including the cerebellar folia and medulla oblongata, but was most prominent in the optic tectum. In the spinal cord, vacuoles were concentrated near the gray matter, and occasional swollen axons were seen. Vacuoles were uniformly present in optic nerves but were not evident in the retina or peripheral or autonomic nerves. Cellular inflammatory response to the lesion was distinctly lacking. Vacuoles were 8-50 microns in diameter and occurred individually, in clusters, or in rows. In sections stained by luxol fast blue/periodic acid-Schiff stain, the vacuoles were delimited and transected by myelin strands. Transmission electron microscopy revealed intramyelinic vacuoles formed in the myelin sheaths by splitting of one or more myelin lamellae at the intraperiodic line. This lesion is characteristic of

  8. Development of general and central obesity from childhood into early adulthood in African American and European American males and females with a family history of cardiovascular disease.

    PubMed

    Dekkers, J Caroline; Podolsky, Robert H; Treiber, Frank A; Barbeau, Paule; Gutin, Bernard; Snieder, Harold

    2004-04-01

    Obesity is associated with multiple health problems, often originating in childhood. The objective was to investigate differences in the development of adiposity from childhood to adulthood as related to race, sex, and socioeconomic status (SES). Individual growth curve modeling for waist circumference, body mass index, and sum of skinfold thicknesses (triceps, subscapular, and suprailiac) was performed in an 11-y cohort study of 622 African Americans and European Americans aged 4.2-27.5 y. We examined the development of adiposity in 2 ways: 1) differences related to race, sex, and parents' education (SES), and 2) differences between obese, overweight, and normal-weight persons at the end of their childhood (> 17 y of age). The sum of skinfold thicknesses was greater in females than in males, with a larger increase with age. Race, sex, and SES showed a complex relation with body mass index and the sum of skinfold thicknesses. The low-SES group showed the fastest increase in waist circumference with age. The obese group showed the most rapid increase in the 3 measures of adiposity. Growth curves for the obese group were distinguishable from those for the normal-weight persons at an earlier age for African Americans than for European Americans. The development rate of adiposity from childhood into early adulthood is influenced by sex and SES but not by race. However, race, sex, and SES had joint effects on adiposity levels. The development of obesity can begin to be distinguished in midchildhood, but the age at which this distinction becomes apparent depends on race.

  9. Callosal axon arbors in the limb representations of the somatosensory cortex (SI) in the agouti (Dasyprocta primnolopha).

    PubMed

    Rocha, E G; Santiago, L F; Freire, M A M; Gomes-Leal, W; Dias, I A; Lent, R; Houzel, J C; Franca, J G; Pereira, A; Picanço-Diniz, C W

    2007-01-10

    The present report compares the morphology of callosal axon arbors projecting from and to the hind- or forelimb representations in the primary somatosensory cortex (SI) of the agouti (Dasyprocta primnolopha), a large, lisencephlic Brazilian rodent that uses forelimb coordination for feeding. Callosal axons were labeled after single pressure (n = 6) or iontophoretic injections (n = 2) of the neuronal tracer biotinylated dextran amine (BDA, 10 kD), either into the hind- (n = 4) or forelimb (n = 4) representations of SI, as identified by electrophysiological recording. Sixty-nine labeled axon fragments located across all layers of contralateral SI representations of the hindlimb (n = 35) and forelimb (n = 34) were analyzed. Quantitative morphometric features such as densities of branching points and boutons, segments length, branching angles, and terminal field areas were measured. Cluster analysis of these values revealed the existence of two types of axon terminals: Type I (46.4%), less branched and more widespread, and Type II (53.6%), more branched and compact. Both axon types were asymmetrically distributed; Type I axonal fragments being more frequent in hindlimb (71.9%) vs. forelimb (28.13%) representation, while most of Type II axonal arbors were found in the forelimb representation (67.56%). We concluded that the sets of callosal axon connecting fore- and hindlimb regions in SI are morphometrically distinct from each other. As callosal projections in somatosensory and motor cortices seem to be essential for bimanual interaction, we suggest that the morphological specialization of callosal axons in SI of the agouti may be correlated with this particular function. (c) 2006 Wiley-Liss, Inc.

  10. Review of continental North and Central American Paracloeodes Day 1955 (Ephemeroptera: Baetidae), including description of a new species from Minnesota, U.S.A.

    PubMed

    Cruz, Paulo Vilela; Usher, Andrew K; Jacobus, Luke M

    2017-05-09

    Paracloeodes Day is a western hemisphere genus with 20 species, but only three of these valid species are known from continental North and Central America. Based on available literature comparisons, species-level identifications of these three species can be difficult. Considering the apparent similarity between them, the main objective of this study was to examine type and other material housed in the Purdue Entomological Research Collection and the University of Minnesota in order to evaluate species status and to elucidate additional diagnostic characters. The evaluation resulted in validation of P. fleeki McCafferty & Lenat, P. lugoi Randolph & McCafferty and P. minutus (Daggy) and the confirmation of P. abditus Day as a junior synonym of P. minutus. Furthermore, we discovered a new species from the type locality of P. minutus. Paracloedes lotor n. sp. is described based on the nymph stage and a putative male imago from the Mississippi River in Minnesota. Paracloeodes lotor n. sp. differs from the other continental North and Central American species of the genus by the apical half of the paraglossa having an abrupt decrease in width (the "subtriangular" condition) in nymphs, and by having the posterior margin of the styliger plate with a small and pointed spine in the male imago. We provide a new identification key for nymphs of the four continental North and Central American species.

  11. The Relationship Between the Signature of Subducted Sediments in Volcanic Gases and Volatile Flux along the Central American Volcanic Arc

    NASA Astrophysics Data System (ADS)

    Fischer, T. P.; Zimmer, M. M.; Hilton, D. R.; Shaw, A. M.; Cameron, B. I.; Walker, J. A.; Molina C., E.

    2002-05-01

    Volcanic arcs are locations where elements are recycled from the Earth's surface into the mantle. Fluxes of volcanic volatile emissions can vary significantly along a single arc and a fundamental aim of arc-related studies is to quantify these variations and compare them to subduction zone parameters. As part of the Central American arc study, we report N2, He and Ar abundance relationships and N-isotope ratios for 7 volcanic centers in Guatemala to complement on-going studies in Costa Rica. In Guatemala, the arc crust is thicker and older than in Costa Rica and the entire sediment sequence on the down-going plate is likely to contribute to the slab flux. Sulfur dioxide fluxes vary significantly along the arc (2001 measurements): in the Guatemala segment, Fuego and Pacaya emit a total of ~1500 t/day whereas in Costa Rica, Arenal and Poas are emitting only ~190 t/day. The Guatemalan volcanic centers of Amatitlan-Pacaya, Fuego, Moyuta, Tecuamburro, Amatitlan, Zunil and San Marcos have N2/He ratios ranging from 2200 - 8100, typical for arc-related fluids. N2/Ar ratios (40-500) and the high N2/He indicate addition of N2 from subducted sediments or arc crust to a mantle derived component (N2/He < 200). The high N2/He ratios of Guatemala are in contrast to typical mantle-derived N2/He ratios (160 - 600) measured at Poas and Turialba, Costa Rica. Nitrogen isotope ratios for the Guatemalan volcanic centers range from δ 15N = + 1.0‰ for San Marcos to + 5.8‰ for Fuego (δ 15N air = 0.0‰ ), indicating a sedimentary nitrogen component. The mantle-derived N2/He ratios for Poas (- 3.0‰ ) are consistent with a more mantle-like δ 15N. In Guatemala, the highest 3He/4He ratios (7.6 for Pacaya and 7.3 Ra for Fuego) correlate with the lowest N2/He ratios (1500 and 2100) and high δ 15N values (+3.8‰ and +5.8‰ ). Mixing relationships (3He/4He and δ 15N) suggest that at Fuego and Pacaya up to 20% of the nitrogen is of subducted sedimentary origin, contrary to Poas and

  12. An investigation of thermal anomalies in the Central American volcanic chain and evaluation of the utility of thermal anomaly monitoring in the prediction of volcanic eruptions. [Central America

    NASA Technical Reports Server (NTRS)

    Stoiber, R. E. (Principal Investigator); Rose, W. I., Jr.

    1975-01-01

    The author has identified the following significant results. Ground truth data collection proves that significant anomalies exist at 13 volcanoes within the test site of Central America. The dimensions and temperature contrast of these ten anomalies are large enough to be detected by the Skylab 192 instrument. The dimensions and intensity of thermal anomalies have changed at most of these volcanoes during the Skylab mission.

  13. Geomorphic analysis of transient landscapes in the Sierra Madre de Chiapas and Maya Mountains (northern Central America): implications for the North American-Caribbean-Cocos plate boundary

    NASA Astrophysics Data System (ADS)

    Andreani, L.; Gloaguen, R.

    2016-01-01

    We use a geomorphic approach in order to unravel the recent evolution of the diffuse triple junction between the North American, Caribbean, and Cocos plates in northern Central America. We intend to characterize and understand the complex tectonic setting that produced an intricate pattern of landscapes using tectonic geomorphology, as well as available geological and geophysical data. We classify regions with specific relief characteristics and highlight uplifted relict landscapes in northern Central America. We also analyze the drainage network from the Sierra Madre de Chiapas and Maya Mountains in order to extract information about potential vertical displacements. Our results suggest that most of the landscapes of the Sierra Madre de Chiapas and Maya Mountains are in a transient stage. Topographic profiles and morphometric maps highlight elevated relict surfaces that are characterized by a low-amplitude relief. The river longitudinal profiles display upper reaches witnessing these relict landscapes. Lower reaches adjust to new base-level conditions and are characterized by multiple knickpoints. These results backed by published GPS and seismotectonic data allow us to refine and extend existing geodynamic models of the triple junction. Relict landscapes are delimited by faults and thus result from a tectonic control. The topography of the Sierra Madre de Chiapas evolved as the result of (1) the inland migration of deformation related to the coupling between the Chiapas Massif and the Cocos forearc sliver and (2) the compression along the northern tip of the Central American volcanic arc. Although most of the shortening between the Cocos forearc sliver and the North American Plate is accommodated within the Sierra de Chiapas and Sierra de los Cuchumatanes, a small part may be still transmitted to the Maya Mountains and the Belize margin through a "rigid" Petén Basin.

  14. Who's behind that mask and cape? The Asian leopard cat's Agouti (ASIP) allele likely affects coat colour phenotype in the Bengal cat breed.

    PubMed

    Gershony, L C; Penedo, M C T; Davis, B W; Murphy, W J; Helps, C R; Lyons, L A

    2014-12-01

    Coat colours and patterns are highly variable in cats and are determined mainly by several genes with Mendelian inheritance. A 2-bp deletion in agouti signalling protein (ASIP) is associated with melanism in domestic cats. Bengal cats are hybrids between domestic cats and Asian leopard cats (Prionailurus bengalensis), and the charcoal coat colouration/pattern in Bengals presents as a possible incomplete melanism. The complete coding region of ASIP was directly sequenced in Asian leopard, domestic and Bengal cats. Twenty-seven variants were identified between domestic and leopard cats and were investigated in Bengals and Savannahs, a hybrid with servals (Leptailurus serval). The leopard cat ASIP haplotype was distinguished from domestic cat by four synonymous and four non-synonymous exonic SNPs, as well as 19 intronic variants, including a 42-bp deletion in intron 4. Fifty-six of 64 reported charcoal cats were compound heterozygotes at ASIP, with leopard cat agouti (A(P) (be) ) and domestic cat non-agouti (a) haplotypes. Twenty-four Bengals had an additional unique haplotype (A2) for exon 2 that was not identified in leopard cats, servals or jungle cats (Felis chaus). The compound heterozygote state suggests the leopard cat allele, in combination with the recessive non-agouti allele, influences Bengal markings, producing a darker, yet not completely melanistic coat. This is the first validation of a leopard cat allele segregating in the Bengal breed and likely affecting their overall pelage phenotype. Genetic testing services need to be aware of the possible segregation of wild felid alleles in all assays performed on hybrid cats. © 2014 The Authors. Animal Genetics published by John Wiley & Sons Ltd on behalf of Stichting International Foundation for Animal Genetics.

  15. The Genetic Contribution of West-African Ancestry to Protection against Central Obesity in African-American Men but Not Women: Results from the ARIC and MESA Studies

    PubMed Central

    Klimentidis, Yann C.; Arora, Amit; Zhou, Jin; Kittles, Rick; Allison, David B.

    2016-01-01

    Over 80% of African-American (AA) women are overweight or obese. A large racial disparity between AA and European-Americans (EA) in obesity rates exists among women, but curiously not among men. Although socio-economic and/or cultural factors may partly account for this race-by-sex interaction, the potential involvement of genetic factors has not yet been investigated. Among 2814 self-identified AA in the Atherosclerosis Risk in Communities study, we estimated each individual's degree of West-African genetic ancestry using 3437 ancestry informative markers. We then tested whether sex modifies the association between West-African genetic ancestry and body mass index (BMI), waist-circumference (WC), and waist-to-hip ratio (WHR), adjusting for income and education levels, and examined associations of ancestry with the phenotypes separately in males and females. We replicated our findings in the Multi-Ethnic Study of Atherosclerosis (n = 1611 AA). In both studies, we find that West-African ancestry is negatively associated with obesity, especially central obesity, among AA men, but not among AA women (pinteraction = 4.14 × 10−5 in pooled analysis of WHR). In conclusion, our results suggest that the combination of male gender and West-African genetic ancestry is associated with protection against central adiposity, and suggest that the large racial disparity that exists among women, but not men, may be at least partly attributed to genetic factors. PMID:27313598

  16. The morphology of the pineal gland of the yellow-toothed cavy (Galea Spixii Wagler, 1831) and red-rumped agouti (Dasyprocta leporina linnaeus, 1758).

    PubMed

    Câmara, Felipe Venceslau; Lopes, Igor Renno Guimarães; de Oliveira, Gleidson Benevides; Bezerra, Ferdinando Vinicius Fernandes; de Oliveira, Radan Elvis Matias; Oliveira Júnior, Carlos Magno; Silva, Alexandre Rodrigues; de Oliveira, Moacir Franco

    2015-08-01

    The pineal gland is an endocrine gland found in all mammals. This article describes the morphology of this important gland in two species of Caviideae, namely the yellow-toothed cavy and the red-rumped agouti. Ten adult animals of the two species used in current analysis were retrieved from the Center for the Multiplication of Wild Animals (CEMAS/UFERSA) and euthanized. The glands were removed and photographed in situ and ex situ. They were fixed in a paraformaldehyde solution 4% or glutaraldehyde 2.5% solution and submitted to routine histological techniques respectively for light and scanning electron microscopy. Macroscopically, the pineal gland with its elongated structure may be found between the cerebral hemispheres facing the rostral colliculi. Microscopically, pinealocytes and some glia cells were predominant. Contrastingly, to the cavy's pineal gland, a capsule covered the organ in the agouti, with the emission of incomplete septa to the interior, which divided it into two lobules. Light and scanning electron microscopes failed to show calcareous concretions in the pineal gland. Based on the topography of the cavy's and agouti's pineal gland, it may be classified as supra-callosum and ABC type.

  17. ECHOCARDIOGRAPHIC FINDINGS OF BIDIMENSIONAL MODE, M-MODE, AND DOPPLER OF CLINICALLY NORMAL BLACK-RUMPED AGOUTI (DASYPROCTA PRYMNOLOPHA, WAGLER 1831).

    PubMed

    Diniz, Anaemilia das Neves; Pessoa, Gerson Tavares; da Silva Moura, Laecio; de Sousa, André Braga; Sousa, Francisco das Chagas Araújo; de Sá Rodrigues, Renan Paraguassu; da Silva Barbosa, Maria Angélica Parente; de Almeida, Hatawa Melo; Freire, Larisse Danielle Silva; Sanches, Marina Pinto; Júnior, Antônio Augusto Nascimento Machado; Guerra, Porfírio Candanedo; Neves, Willams Costa; de Sousa, João Macedo; Bolfer, Luiz; Giglio, Robson Fortes; Alves, Flávio Ribeiro

    2017-06-01

    The black-rumped agouti ( Dasyprocta prymnolopha , Wagler 1831) is currently under intense ecologic pressure, which has resulted in its disappearance from some regions of Brazil. Echocardiography is widely used in veterinary medicine but it is not yet part of the clinical routine for wild animals. The objective of the present study was to assess the applicability of the echocardiographic exam in nonanesthetized agouti and to establish normal reference values for echocardiographic measurements in bidimensional mode (2D), M-mode, and Doppler for this species, and a lead II electrocardiogram was simultaneously recorded. Twenty agouti were used in this study. All the echocardiographic measurements were positively correlated with weight (P < 0.05), and there were no significant differences between sexes (P > 0.05). Blood flow velocities in the pulmonary and aortic artery ranged from 67.32-71.28 cm/sec and 79.22-101.84 cm/sec, respectively. The isovolumic relaxation time was assessed in all the animals and ranged from 38.5 to 56.6 ms. The maximum value for the nonfused E and A waves and the Et and At waves was 158 beats/min for both. The results obtained for the morphologic and heart hemodynamic measurements can guide future studies and help in the clinical management of these animals in captivity.

  18. Evaluation of minerals, phytochemical compounds and antioxidant activity of Mexican, Central American, and African green leafy vegetables

    USDA-ARS?s Scientific Manuscript database

    The green leafy vegetables Cnidoscolus aconitifolius and Crotalaria longirostrata are native to Mexico and Central America, while Solanum scabrum and Gynandropsis gynandra are native to Africa. They are consumed in both rural and urban areas in those places as a main food, food ingredient or traditi...

  19. When Children Are Water: Representation of Central American Migrant Children in Public Discourse and Implications for Educators

    ERIC Educational Resources Information Center

    Catalano, Theresa

    2017-01-01

    Since June, 2014 when the U.S. government began to document an increase in unaccompanied/separated children arriving in the United States from Central America, these children have become a frequent topic in media discourse. Because rhetoric about immigration issues have been shown to affect schooling of these children, the present article aims to…

  20. New evidence for geologically instantaneous emplacement of earliest Jurassic Central Atlantic magmatic province basalts on the North American margin

    NASA Astrophysics Data System (ADS)

    Hames, W. E.; Renne, P. R.; Ruppel, C.

    2000-09-01

    Dikes in the southeastern United States represent a major component of the Central Atlantic magmatic province and record kinematics of Pangean breakup near the critical, predrift junction of three major continental masses. Until now, the age of these dikes had not been determined with the same precision as those of Central Atlantic magmatic province basalts on other parts of the circum-Atlantic margin. Our new results for three dike samples from the South Carolina Piedmont yield plateau ages of 198.8 ± 2.2, 199.5 ± 1.8, and 199.7 ± 1.5 Ma. For comparison, we present new age determinations of the benchmark Watchung flows I and III of the Newark basin: 201.0 ± 2.1 and 198.8 ± 2.0 Ma, respectively. Collectively, these data suggest that basaltic volcanism responsible for the dikes, flows, and sills of eastern North America occurred within ˜1 m.y. of 200 Ma. The timing, brief duration, and extent of the Central Atlantic magmatism imply that it may have been causally related to Triassic-Jurassic mass extinctions. The distribution and timing of this magmatism and the absence of regional uplift or an identifiable hotspot track lead us to favor strong lithospheric control on the origin of the Central Atlantic magmatic province, consistent with the modern generation of plume incubation or edge-driven convection models.

  1. Characterization and efficacy determination of commercially available Central American H5N2 avian influenza vaccines for poultry

    USDA-ARS?s Scientific Manuscript database

    A poultry vaccination program was implemented in Central America beginning in January 1995 to control both H5N2 low (LPAI) and high pathogenicity avian influenza. This study was conducted to identify seed strain composition and the efficacy of nine commercially available H5 vaccines against challen...

  2. Centralization of Penile Cancer Management in the United States: A Combined Analysis of the American Board of Urology and National Cancer Data Base.

    PubMed

    Matulewicz, Richard S; Flum, Andrew S; Helenowski, Irene; Jovanovic, Borko; Palis, Bryan; Bilimoria, Karl Y; Meeks, Joshua J

    2016-04-01

    To assess the potential benefit of centralization of care in penile cancer. Centralization of care in other disease processes standardizes treatment and improves outcomes. Because penile cancer is a rare malignancy with unchanged mortality rates over the last two decades, we hypothesize that there may be a benefit to centralization. We identified surgeon, patient, and hospital characteristics captured by the National Cancer Data Base (1998-2012) and American Board of Urology case logs (2003-2013) for all penile cancer cases and procedures. Differences in patient demographics, stage of disease, referral patterns, and surgical quality indicators were assessed between academic and community hospitals. Using case logs to evaluate the distribution of penile cancer care, we found that only 4.1% of urologists performed a penile surgery and 1.5% performed a lymph node dissection (LND). Academic centers treated higher-stage cancers and saw more cases/year than community centers, suggesting informal centralization. Two guideline-based quality indicators demonstrated no difference in use of penile-sparing surgery but a higher likelihood of having an LND performed at an academic center (48.4% vs 26.6%). The total lymph node yield was significantly greater at academic centers (18.5 vs 12.5). Regression modeling demonstrated a 2.29 increased odds of having an LND at an academic center. Our data provide the first evidence for centralization of penile cancer in the US. At the time of diagnosis, equal number of patients is treated with penile-sparing surgery but there is greater use of LND and higher lymph node yield at academic centers. Ultimately, longer follow-up is necessary to determine if this improves survival of patients with penile cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. A new radiative forcing data set comprising the major volcanic eruptions from the Central American Volcanic Arc for paleo climate studies

    NASA Astrophysics Data System (ADS)

    Metzner, D.; Krüger, K.; Timmreck, C.; Kutterolf, S.; Freundt, A.

    2009-04-01

    Of all the natural causes of climate change, major volcanic eruptions are most important as they have a significant impact on Earth's global climate system, especially on the stratosphere and troposphere, the atmospheric circulation and chemical composition. The direct injection of gases, aerosols and volcanic ash into the stratosphere has a strong and long lasting radiative influence, which leads to a global cooling of surface temperatures for several years, probably decades. In this study we will investigate the climate feedbacks of large Plinian eruptions from volcanoes at the Central American Arc within the last 200ka with the help of state of the art climate models. To evaluate the radiative forcing of the climate system, we need reliable estimates of the paleo volcanic stratospheric aerosol loading. Here we use a newly derived volcanic data set for Central America based on a) new eruptive mass estimations that are based on compositional land-sea correlations of widespread tephra layers and b) incoporation of measured degassed volatile fractions (S, Cl, F, Br, I) derived from those tephras by the "petrological method" into the mass calculations (Kutterolf et al. 2008a,b). This facilitates the consideration of large eruptions of the past for climate modelling. Using information about strength and height of the volcanic sulphur injection we create a new data set of aerosol optical depth comprising the major volcanic eruptions of Central American Volcanic Arc over the last 200ka. The poster will introduce the underlying steps to derive an aerosol optical depth set from the petrologic derived sulfate aerosol loading in more detail and discuss possible uncertainties. As soon as possible climate sensitivity studies will follow, in which different SO2 scenarios will be applied, for low, medium and large size SO2 eruptions. To assess the climate impact of past CAVA eruptions on a paleo time scale an earth system climate model of intermediate complexity will be

  4. Geomorphic analysis of transient landscapes from the Sierra Madre de Chiapas and Maya Mountains (northern Central America): implications for the North American-Caribbean-Cocos plate boundary

    NASA Astrophysics Data System (ADS)

    Andreani, L.; Gloaguen, R.

    2015-09-01

    We use a geomorphic approach in order to unravel the recent evolution of the diffuse triple junction between the North American, Caribbean, and Cocos plates in northern Central America. The complex tectonic setting produced an intricate pattern of landscapes that we try to systemize using remote sensing tectonic geomorphology and available geological and geophysical data. We classify regions with specific relief characteristics and highlight uplifted relict landscapes in northern Central America. We also analyze the drainage network from the Sierra Madre de Chiapas and Maya Mountains in order to extract information about potential vertical displacements. Our results suggest that most of the landscapes of the Sierra Madre de Chiapas and Maya Mountains are in transient stage. Topographic profiles and morphometric maps highlight elevated relict surfaces that are characterized by a low amplitude relief. The river longitudinal profiles display upper reaches witnessing these relict landscapes while lower segments characterized by multiple knickpoints, that adjust to new base-level conditions. These results backed by published GPS and seismotectonic data allow us to refine and extend existing geodynamic models of the triple junction. Relict landscapes are delimited by faults and thus result from a tectonic control. The topography of the Sierra Madre de Chiapas evolved as the result of (1) the inland migration of deformation related to the coupling between the Chiapas Massif and the Cocos fore-arc sliver, and (2) the compression along the northern tip of the Central America Volcanic Arc. Although most of the shortening between the Cocos fore-arc sliver and the North American plate is accommodated within the Sierra de Chiapas and Sierra de los Cuchumatanes, a small part may be still transmitted to the Maya Mountains and the Belize margin through a "rigid" Petén basin.

  5. Coat colours in the Massese sheep breed are associated with mutations in the agouti signalling protein (ASIP) and melanocortin 1 receptor (MC1R) genes.

    PubMed

    Fontanesi, L; Dall'Olio, S; Beretti, F; Portolano, B; Russo, V

    2011-01-01

    Massese is an Italian dairy sheep breed characterized by animals with black skin and horns and black or apparent grey hairs. Owing to the presence of these two coat colour types, this breed can be considered an interesting model to evaluate the effects of coat colour gene polymorphisms on this phenotypic trait. Two main loci have been already shown to affect coat colour in sheep: Agouti and Extension coding for the agouti signalling protein (ASIP) and melanocortin 1 receptor (MC1R) genes, respectively. The Agouti locus is affected by a large duplication including the ASIP gene that may determine the Agouti white and tan allele (A(Wt)). Other disrupting or partially inactivating mutations have been identified in exon 2 (a deletion of 5 bp, D(5); and a deletion of 9 bp, D(9)) and in exon 4 (g.5172T>A, p.C126S) of the ASIP gene. Three missense mutations in the sheep MC1R gene cause the dominant black E(D) allele (p.M73K and p.D121N) and the putative recessive e allele (p.R67C). Here, we analysed these ASIP and MC1R mutations in 161 Massese sheep collected from four flocks. The presence of one duplicated copy allele including the ASIP gene was associated with grey coat colour (P = 9.4E-30). Almost all animals with a duplicated copy allele (37 out of 41) showed uniform apparent grey hair and almost all animals without a duplicated allele (117 out of 120) were completely black. Different forms of duplicated alleles were identified in Massese sheep including, in almost all cases, copies with exon 2 disrupting or partially inactivating mutations making these alleles different from the A(Wt) allele. A few exceptions were observed in the association between ASIP polymorphisms and coat colour: three grey sheep did not carry any duplicated copy allele and four black animals carried a duplicated copy allele. Of the latter four sheep, two carried the E(D) allele of the MC1R gene that may be the cause of their black coat colour. The coat colour of all other black animals may be

  6. Prevalence of Diabetes and Intermediate Hyperglycemia Among Adults From the First Multinational Study of Noncommunicable Diseases in Six Central American Countries

    PubMed Central

    Barcelo, Alberto; Gregg, Edward W.; Gerzoff, Robert B.; Wong, Roy; Perez Flores, Enrique; Ramirez-Zea, Manuel; Cafiero, Elizabeth; Altamirano, Lesbia; Ascencio Rivera, Melanie; de Cosio, Gerardo; de Maza, Martha Dinorah; del Aguila, Roberto; Emanuel, Englebert; Gil, Enrique; Gough, Ethan; Jenkins, Valerie; Orellana, Patrícia; Palma, Ruben; Palomo, Ruben; Pastora, Martha; Peña, Rodolfo; Pineda, Elia; Rodriguez, Bismark; Tacsan, Luis; Thompson, Loraine; Villagra, Lucy

    2012-01-01

    OBJECTIVE The increasing burdens of obesity and diabetes are two of the most prominent threats to the health of populations of developed and developing countries alike. The Central America Diabetes Initiative (CAMDI) is the first study to examine the prevalence of diabetes in Central America. RESEARCH DESIGN AND METHODS The CAMDI survey was a cross-sectional survey based on a probabilistic sample of the noninstitutionalized population of five Central American populations conducted between 2003 and 2006. The total sample population was 10,822, of whom 7,234 (67%) underwent anthropometry measurement and a fasting blood glucose or 2-h oral glucose tolerance test. RESULTS The total prevalence of diabetes was 8.5%, but was higher in Belize (12.9%) and lower in Honduras (5.4%). Of the screened population, 18.6% had impaired glucose tolerance/impaired fasting glucose. CONCLUSIONS As this population ages, the prevalence of diabetes is likely to continue to rise in a dramatic and devastating manner. Preventive strategies must be quickly introduced. PMID:22323417

  7. Future changes in Central American temperature and precipitation in an ensemble of CORDEX regional climate model simulations

    NASA Astrophysics Data System (ADS)

    Nikulin, Grigory; Fuentes Franco, Ramon; Kjellström, Erik; Rana, Arun

    2017-04-01

    In this study we investigate possible changes in temperature and precipitation on a regional scale over Central America from 1951 to 2100. We use data from two ensembles of climate simulations, one global and one regional, over the Central America CORDEX domain. The global ensemble includes ten coupled atmosphere ocean general circulation models (AOGCMs) from the CMIP5 project with horizontal resolution varying from about 1° to 3°, namely CanESM2, CSIRO-Mk3, CNRM-CM5, HadGEM2-ES, NorESM1-M, EC-EARTH, MIROC5, GFDL-ESM2M, MPI-ESM-LR and NorESM1-M. In the regional ensemble all 10 AOGCMs are downscaled at the Rossby Centre (SMHI) by a regional climate model - RCA4 at 0.44° resolution under the RCP8.5 forcing scenario and five of ten under the RCP26 one. The experimental setup allows us to illustrate how uncertainties in future climate change are related to forcing scenario and to forcing AOGCM at different time periods. Further, taking both global and regional ensembles and focusing on seasonal mean temperature and precipitation over Central America we i) evaluate ability of the ensembles and their individual members to simulate the observed climatology in Central America, ii) analyse similarities and contradictions in future climate projections between two ensembles and iii) assess how both ensembles capture the spread of the grand CMIP5 ensemble. We also address higher-order variability by showing results for changes in temperature extremes and for changes in intensity and frequency of extreme precipitation.

  8. Agouti Related Peptide Secreted Via Human Mesenchymal Stem Cells Upregulates Proteasome Activity in an Alzheimer’s Disease Model

    PubMed Central

    Lee, Na Kyung; Park, Sang Eon; Kwon, Soo Jin; Shim, Sangmi; Byeon, Yeji; Kim, Jong-Hwa; Na, Duk L.; Chang, Jong Wook

    2017-01-01

    The activity of the ubiquitin proteasome system (UPS) is downregulated in aggregation diseases such as Alzheimer’s disease (AD). In this study, we investigated the therapeutic potential of the Agouti-related peptide (AgRP), which is secreted by human mesenchymal stem cells (MSCs), in terms of its effect on the regulation of proteasome activity in AD. When SH-SY5Y human neuroblastoma cells were co-cultured with MSCs isolated from human Wharton’s Jelly (WJ-MSC), their proteasome activity was significantly upregulated. Further analysis of the conditioned media after co-culture allowed us to identify significant concentrations of a neuropeptide, called AgRP. The stereotactic delivery of either WJ-MSCs or AgRP into the hippocampi of C57BL6/J and 5XFAD mice induced a significant increase of proteasome activity and suppressed the accumulation of ubiquitin-conjugated proteins. Collectively, these findings suggest strong therapeutic potential for WJ-MSCs and AgRP to enhance proteasome activity, thereby potentially reducing abnormal protein aggregation and delaying the clinical progression of various neurodegenerative diseases. PMID:28051110

  9. Neuropeptide Y and agouti-related peptide mediate complementary functions of hyperphagia and reduced energy expenditure in leptin receptor deficiency.

    PubMed

    Luo, Na; Marcelin, Genevieve; Liu, Shun Mei; Schwartz, Gary; Chua, Streamson

    2011-03-01

    Neuropeptide Y (NPY) and agouti-related peptide (AGRP) can produce hyperphagia, reduce energy expenditure, and promote triglyceride deposition in adipose depots. As these two neuropeptides are coexpressed within the hypothalamic arcuate nucleus and mediate a major portion of the obesity caused by leptin signaling deficiency, we sought to determine whether the two neuropeptides mediated identical or complementary actions. Because of separate neuropeptide receptors and signal transduction mechanisms, there is a possibility of distinct encoding systems for the feeding and energy expenditure aspects of leptin-regulated metabolism. We have genetically added NPY deficiency and/or AGRP deficiency to LEPR deficiency isolated to AGRP cells. Our results indicate that the obesity of LEPR deficiency in AGRP/NPY neurons can produce obesity with either AGRP or NPY alone with AGRP producing hyperphagia while NPY promotes reduced energy expenditure. The absence of both NPY and AGRP prevents the development of obesity attributable to isolated LEPR deficiency in AGRP/NPY neurons. Operant behavioral testing indicated that there were no alterations in the reward for a food pellet from the AGRP-specific LEPR deficiency.

  10. PDK1-Foxo1 in Agouti-Related Peptide Neurons Regulates Energy Homeostasis by Modulating Food Intake and Energy Expenditure

    PubMed Central

    Cao, Yongheng; Nakata, Masanori; Okamoto, Shiki; Takano, Eisuke; Yada, Toshihiko; Minokoshi, Yasuhiko; Hirata, Yukio; Nakajima, Kazunori; Iskandar, Kristy; Hayashi, Yoshitake; Ogawa, Wataru; Barsh, Gregory S.; Hosoda, Hiroshi; Kangawa, Kenji; Itoh, Hiroshi; Noda, Tetsuo; Kasuga, Masato; Nakae, Jun

    2011-01-01

    Insulin and leptin intracellular signaling pathways converge and act synergistically on the hypothalamic phosphatidylinositol-3-OH kinase/3-phosphoinositide-dependent protein kinase 1 (PDK1). However, little is known about whether PDK1 in agouti-related peptide (AGRP) neurons contributes to energy homeostasis. We generated AGRP neuron-specific PDK1 knockout (AGRPPdk1−/−) mice and mice with selective expression of transactivation-defective Foxo1 (Δ256Foxo1AGRPPdk1−/−). The AGRPPdk1−/− mice showed reductions in food intake, body length, and body weight. The Δ256Foxo1AGRPPdk1−/− mice showed increased body weight, food intake, and reduced locomotor activity. After four weeks of calorie-restricted feeding, oxygen consumption and locomotor activity were elevated in AGRPPdk1−/− mice and reduced in Δ256Foxo1AGRPPdk1−/− mice. In vitro, ghrelin-induced changes in [Ca2+]i and inhibition of ghrelin by leptin were significantly attenuated in AGRPPdk1−/− neurons compared to control neurons. However, ghrelin-induced [Ca2+]i changes and leptin inhibition were restored in Δ256Foxo1AGRPPdk1−/− mice. These results suggested that PDK1 and Foxo1 signaling pathways play important roles in the control of energy homeostasis through AGRP-independent mechanisms. PMID:21694754

  11. Characterization, tissue distribution and regulation of agouti-related protein (AgRP) in a cyprinid fish (Schizothorax prenanti).

    PubMed

    Wei, RongBin; Yuan, DengYue; Wang, Tao; Zhou, ChaoWei; Lin, FangJun; Chen, Hu; Wu, HongWei; Yang, ShiYong; Wang, Yan; Liu, Ju; Gao, YunDi; Li, ZhiQiong

    2013-09-15

    Agouti-related protein (AgRP) is an important neuropeptide involved in the regulation of feeding in both mammals and fish. In this study, we have cloned the full-length cDNA sequence for AgRP in a cyprinid fish (Schizothorax prenanti). The AgRP gene, encoding 126-amino acids, was strongly expressed in the brain. The AgRP gene was detected in embryos at developmental stages. Further, its mRNA was detectable in unfertilized eggs. An experiment was conducted to determine the expression profile of AgRP during short-term and long-term fasting of the hypothalamus. The expression level of AgRP in unfed fish was significantly increased at 3 and 4h post-fasting than in fed fish but did not affect AgRP mRNA expression after 14 days fasting. Overall, our results suggest that AgRP is a conserved peptide that might be involved in the regulation of short-term feeding and other physiological function in Schizothorax prenanti. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. [The influence of hyperleptinemia during pregnancy on fetal weight and obesity development in progeny mice with agouti yellow mutation].

    PubMed

    Makarova, E N; Syracheva, M S; Bazhan, N M

    2014-03-01

    Maternal obesity increases the risk of obesity in the offspring, and obesity is accompanied by an increase in blood leptin levels. Leptin can influence the progeny metabolism via its influence on fetal growth and, possibly, via its action on AgRP expression in placenta. The "yellow" mutation at the mouse agouti locus (A(y)) evokes obesity and increases blood leptin levels in pregnant mice. The aim was to examine the influence of A(y) mutation in pregnant mice on fetal weight, placental expression of AgRP gene and food intake and obesity development in progeny. A(y) pregnant females as compared to control ones had increased circulating leptin levels on days 13 and 18 of pregnancy. Both fetal weight and placental expression of AgRP gene were increased on day 13 of pregnancy and decreased on day 18 of pregnancy in A(y) females as compared to control ones. Both control (a/a) and obesity prone (A(y)/a) male young born to A(y) mothers had lowered body weight and enhanced food intake between 5 and 11 weeks of age as compared to male progeny of control mothers. The enhanced leptin levels during pregnancy in mice are associated with retardation of obesity development in obesity prone male offspring and with changes in fetal weight and AgRP gene expression in placenta.

  13. Analysis of agouti signaling protein (ASIP) gene polymorphisms and association with coat color in Tibetan sheep (Ovis aries).

    PubMed

    Han, J L; Yang, M; Yue, Y J; Guo, T T; Liu, J B; Niu, C E; Yang, B H

    2015-02-06

    Tibetan sheep, an indigenous breed, have a wide variety of phenotypes and a colorful coat, which make this breed an interesting model for evaluating the effects of coat-color gene mutations on this phenotypic trait. The agouti signaling protein (ASIP) gene is a positional candidate gene, as was inferred based on previous study. In our research, ASIP gene copy numbers in genomic DNA were detected using a novel approach, and the exon 2 g.100-104 mutation and copy number variation (CNV) of ASIP were associated with coat color in 256 sheep collected from eight populations with different coat colors by high-resolution melting curve assay. We found that the relative copy numbers of ASIP ranged from one to eight in Tibetan sheep. All of the g.100-104 genotypes in the populations were in Hardy-Weinberg equilibrium, and there was no relationship between the g.100-104 genotype and coat color (P > 0.05). The single ASIP CNV allele was found to be almost entirely associated with solid-black coat color; however, not all solid-black sheep displayed the putative single ASIP CNV genotype. From our study, we speculate that the ASIP CNV is under great selective pressure and the single ASIP CNV allows selection for black coat color in Tibetan sheep, but this does not explain all black phenotypes in Tibetan sheep.

  14. Polymorphism of the goat agouti signaling protein gene and its relationship with coat color in Italian and Spanish breeds.

    PubMed

    Badaoui, B; D'Andrea, M; Pilla, F; Capote, J; Zidi, A; Jordana, J; Ferrando, A; Delgado, J V; Martínez, A; Vidal, O; Amills, M

    2011-08-01

    Agouti signaling protein (ASIP) is one of the key players in the modulation of hair pigmentation in mammals. Binding to the melanocortin 1 receptor, ASIP induces the synthesis of phaeomelanin, associated with reddish brown, red, tan, and yellow coats. We have sequenced 2.8 kb of the goat ASIP gene in 48 individuals and identified two missense (Cys126Gly and Val128Gly) and two intronic polymorphisms. In silico analysis revealed that the Cys126Gly substitution may cause a structural change by disrupting a highly conserved disulfide bond. We studied its segregation in 12 Spanish and Italian goat breeds (N = 360) with different pigmentation patterns and found striking differences in the frequency of the putative loss-of-function Gly(126) allele (Italian 0.43, Spanish Peninsular 0.08), but we did not observe a clear association with coat color. This suggests that the frequency of this putative loss-of-function allele has evolved under the influence of demographic rather than selection factors in goats from these two geographical areas.

  15. Chronic central serotonin depletion attenuates ventilation and body temperature in young but not adult Tph2 knockout rats.

    PubMed

    Kaplan, Kara; Echert, Ashley E; Massat, Ben; Puissant, Madeleine M; Palygin, Oleg; Geurts, Aron M; Hodges, Matthew R

    2016-05-01

    Genetic deletion of brain serotonin (5-HT) neurons in mice leads to ventilatory deficits and increased neonatal mortality during development. However, it is unclear if the loss of the 5-HT neurons or the loss of the neurochemical 5-HT led to the observed physiologic deficits. Herein, we generated a mutant rat model with constitutive central nervous system (CNS) 5-HT depletion by mutation of the tryptophan hydroxylase 2 (Tph2) gene in dark agouti (DA(Tph2-/-)) rats. DA(Tph2-/-) rats lacked TPH immunoreactivity and brain 5-HT but retain dopa decarboxylase-expressing raphe neurons. Mutant rats were also smaller, had relatively high mortality (∼50%), and compared with controls had reduced room air ventilation and body temperatures at specific postnatal ages. In adult rats, breathing at rest and hypoxic and hypercapnic chemoreflexes were unaltered in adult male and female DA(Tph2-/-) rats. Body temperature was also maintained in adult DA(Tph2-/-) rats exposed to 4°C, indicating unaltered ventilatory and/or thermoregulatory control mechanisms. Finally, DA(Tph2-/-) rats treated with the 5-HT precursor 5-hydroxytryptophan (5-HTP) partially restored CNS 5-HT and showed increased ventilation (P < 0.05) at a developmental age when it was otherwise attenuated in the mutants. We conclude that constitutive CNS production of 5-HT is critically important to fundamental homeostatic control systems for breathing and temperature during postnatal development in the rat. Copyright © 2016 the American Physiological Society.

  16. Molecular evolution of southern North American Cyprinidae (Actinopterygii), with the description of the new genus Tampichthys from central Mexico.

    PubMed

    Schönhuth, Susana; Doadrio, Ignacio; Dominguez-Dominguez, Omar; Hillis, David M; Mayden, Richard L

    2008-05-01

    Most of the recognized species of the genus Dionda inhabit drainages of the Gulf of Mexico from central Mexico to central Texas, USA, and have been considered a monophyletic group based on morphological, osteological, and allozyme investigations. Phylogenetic relationships of 15 species of Dionda and 34 species from closely related genera were inferred from one mitochondrial (cytb) and three nuclear gene sequences (S7, Rhodopsin, Rag1) totaling 4487 nucleotides. Separate analyses of all four genes yield congruent phylogenies; however the 15 putative species of Dionda evaluated were never recovered as a monophyletic group when species from nine related genera were included in the analyses. Among the ingroup taxa, one well-supported and highly divergent clade is consistently recognized and consists of six recognized and three undescribed northern species currently recognized in the genus Dionda. These nine species inhabit present or past tributaries of the Rio Grande basin of northern Mexico and southern USA, and were recovered as a basal clade in all analyses. Another large, also strongly supported clade, consisting of seven genera, include five southern recognized species currently in the genus Dionda, forming the sister group to the Codoma clade. These five species comprise the "Southern Dionda clade" and inhabit headwaters of the Pánuco-Tamesí drainage and some adjacent coastal rivers in the Tampico Embayment. The consistent and repeated identification of eight different clades recovered in most of the separate gene analyses strongly supports a division of the non-natural genus Dionda. A new genus, Tampichthys, is proposed for the clade of species endemic to east-central Mexico and formerly in Dionda. Tampichthys and the putative monotypic genus Codoma are more related to Mexican species of the genera Cyprinella and Notropis than to other species referred to Dionda sensu stricto.

  17. Population genetic structure of traditional populations in the Peruvian Central Andes and implications for South American population history.

    PubMed

    Cabana, Graciela S; Lewis, Cecil M; Tito, Raúl Y; Covey, R Alan; Cáceres, Angela M; Cruz, Augusto F De La; Durand, Diana; Housman, Genevieve; Hulsey, Brannon I; Iannacone, Gian Carlo; López, Paul W; Martínez, Rolando; Medina, Ángel; Dávila, Olimpio Ortega; Pinto, Karla Paloma Osorio; Santillán, Susan I Polo; Domínguez, Percy Rojas; Rubel, Meagan; Smith, Heather F; Smith, Silvia E; Massa, Verónica Rubín de Celis; Lizárraga, Beatriz; Stone, Anne C

    2014-01-01

    Molecular-based characterizations of Andean peoples are traditionally conducted in the service of elucidating continent-level evolutionary processes in South America. Consequently, genetic variation among "western" Andean populations is often represented in relation to variation among "eastern" Amazon and Orinoco River Basin populations. This west-east contrast in patterns of population genetic variation is typically attributed to large-scale phenomena, such as dual founder colonization events or differing long-term microevolutionary histories. However, alternative explanations that consider the nature and causes of population genetic diversity within the Andean region remain underexplored. Here we examine population genetic diversity in the Peruvian Central Andes using data from the mtDNA first hypervariable region and Y-chromosome short tandem repeats among 17 newly sampled populations and 15 published samples. Using this geographically comprehensive data set, we first reassessed the currently accepted pattern of western versus eastern population genetic structure, which our results ultimately reject: mtDNA population diversities were lower, rather than higher, within Andean versus eastern populations, and only highland Y-chromosomes exhibited significantly higher within-population diversities compared with eastern groups. Multiple populations, including several highland samples, exhibited low genetic diversities for both genetic systems. Second, we explored whether the implementation of Inca state and Spanish colonial policies starting at about ad 1400 could have substantially restructured population genetic variation and consequently constitute a primary explanation for the extant pattern of population diversity in the Peruvian Central Andes. Our results suggest that Peruvian Central Andean population structure cannot be parsimoniously explained as the sole outcome of combined Inca and Spanish policies on the region's population demography: highland populations

  18. Redescriptions and lectotype designations of Central American species of Phaenonotum Sharp (Coleoptera, Hydrophilidae) based on the type material from the David Sharp collection.

    PubMed

    Deler-Hernández, Albert; Fikáček, Martin

    2016-01-01

    In order to understand the identity of the Central American species of the genus Phaenonotum Sharp, 1882, the type specimens of the species described by Sharp (1882) deposited in the David Sharp collection in the Natural History Museum in London have been re-examined. The following species are redescribed: Phaenonotum apicale Sharp, 1882, Phaenonotum collare Sharp, 1882, Phaenonotum dubium Sharp, 1882 (confirmed as junior synonym of Phaenonotum exstriatum (Say, 1835)), Phaenonotum laevicolle Sharp, 1882, Phaenonotum rotundulum Sharp, 1882 and Phaenonotum tarsale Sharp, 1882. Lectotypes are designated for Phaenonotum apicale, Phaenonotum collare, Phaenonotum rotundulum and Phaenonotum tarsale. External diagnostic characters and morphology of male genitalia are illustrated. A table summarizing diagnostic characters allowing the identification of the species is provided.

  19. Olfactory Response and Host Plant Feeding of the Central American Locust Schistocerca piceifrons piceifrons Walker to Common Plants in a Gregarious Zone.

    PubMed

    Poot-Pech, M A; Ruiz-Sánchez, E; Ballina-Gómez, H S; Gamboa-Angulo, M M; Reyes-Ramírez, A

    2016-08-01

    The Central American locust (CAL) Schistocerca piceifrons piceifrons Walker is one of the most harmful plant pests in the Yucatan Peninsula, where an important gregarious zone is located. The olfactory response and host plant acceptance by the CAL have not been studied in detail thus far. In this work, the olfactory response of the CAL to odor of various plant species was evaluated using an olfactometer test system. In addition, the host plant acceptance was assessed by the consumption of leaf area. Results showed that the CAL was highly attracted to odor of Pisonia aculeata. Evaluation of host plant acceptance showed that the CAL fed on Leucaena glauca and Waltheria americana, but not on P. aculeata or Guazuma ulmifolia. Analysis of leaf thickness, and leaf content of nitrogen (N) and carbon (C) showed that the CAL was attracted to plant species with low leaf C content.

  20. Probabilities of future VEI ≥ 2 eruptions at the Central American Volcanic Arc: a statistical perspective based on the past centuries' eruption record

    NASA Astrophysics Data System (ADS)

    Dzierma, Yvonne; Wehrmann, Heidi

    2014-10-01

    A probabilistic eruption forecast is provided for seven historically active volcanoes along the Central American Volcanic Arc (CAVA), as a pivotal empirical contribution to multi-disciplinary volcanic hazards assessment. The eruption probabilities are determined with a Kaplan-Meier estimator of survival functions, and parametric time series models are applied to describe the historical eruption records. Aside from the volcanoes that are currently in a state of eruptive activity (Santa María, Fuego, and Arenal), the highest probabilities for eruptions of VEI ≥ 2 occur at Concepción and Cerro Negro in Nicaragua, which are likely to erupt to 70-85 % within the next 10 years. Poás and Irazú in Costa Rica show a medium to high eruption probability, followed by San Miguel (El Salvador), Rincón de la Vieja (Costa Rica), and Izalco (El Salvador; 24 % within the next 10 years).

  1. Aspects of reproductive ecology of Clusia valerioi Standl. and Clusia peninsulae Hammel (sp. nov.), two Central American species of Clusiaceae with resin flowers.

    PubMed

    Hochwallner, H; Vogel, S; Huber, W; Hammel, B E; Weber, A

    2012-01-01

    Clusia valerioi Standl. and C. peninsulae Hammel, sp. nov. (formally established in the Appendix), two Central American species of Clusiaceae offering resin as a floral reward, were studied in the Piedras Blancas National Park, SW Costa Rica. Basic data on phenology, flower structure, course of anthesis, flower visitors, flower visitation and pollination processes, fruit development and seed dispersal are communicated. Resin collection and pollen release are reported and documented in greater detail. The significance of stingless bees for pollination is confirmed, but honeybees were also observed to visit the flowers and to collect resin. The seeds of C. valerioi, exhibiting a clearly ornithochorous character syndrome, were observed to be eaten and dispersed by four species of the tanager family (Thraupidae) and one species of finch (Fringillidae). Ants were also observed to carry away the seeds. © 2011 German Botanical Society and The Royal Botanical Society of the Netherlands.

  2. Redescriptions and lectotype designations of Central American species of Phaenonotum Sharp (Coleoptera, Hydrophilidae) based on the type material from the David Sharp collection

    PubMed Central

    Deler-Hernández, Albert; Fikáček, Martin

    2016-01-01

    Abstract In order to understand the identity of the Central American species of the genus Phaenonotum Sharp, 1882, the type specimens of the species described by Sharp (1882) deposited in the David Sharp collection in the Natural History Museum in London have been re-examined. The following species are redescribed: Phaenonotum apicale Sharp, 1882, Phaenonotum collare Sharp, 1882, Phaenonotum dubium Sharp, 1882 (confirmed as junior synonym of Phaenonotum exstriatum (Say, 1835)), Phaenonotum laevicolle Sharp, 1882, Phaenonotum rotundulum Sharp, 1882 and Phaenonotum tarsale Sharp, 1882. Lectotypes are designated for Phaenonotum apicale, Phaenonotum collare, Phaenonotum rotundulum and Phaenonotum tarsale. External diagnostic characters and morphology of male genitalia are illustrated. A table summarizing diagnostic characters allowing the identification of the species is provided. PMID:27110202

  3. The relative contribution of income inequality and imprisonment to the variation in homicide rates among Developed (OECD), South and Central American countries.

    PubMed

    Nadanovsky, Paulo; Cunha-Cruz, Joana

    2009-11-01

    Homicide rates vary widely across and within different continents. In order to address the problem of violence in the world, it seems important to clarify the sources of this variability. Despite the fact that income inequality and imprisonment seem to be two of the most important determinants of the variation in homicide rates over space and time, the concomitant effect of income inequality and imprisonment on homicide has not been examined. The objective of this cross-sectional ecological study was to investigate the association of income inequality and imprisonment with homicide rates among Developed (OECD), South and Central American countries. A novel index was developed to indicate imprisonment: the Impunity Index (the total number of homicides in the preceding decade divided by the number of persons in prison at a single slice in time). Negative binomial models were used to estimate rate ratios of homicides for young males and for the total population in relation to Gini Index and Impunity Index, controlling for infant mortality (as a proxy for poverty levels), Gross Domestic Product per-capita, education, percentage of young males in the population and urbanization. Both low income inequality and low impunity (high imprisonment of criminals) were related to low homicide rates. In addition, we found that countries with lower income inequality, lower infant mortality (less poverty), higher average income (GDP per-capita) and higher levels of education had low impunity. Our results are compatible with the hypothesis that both low income inequality and imprisonment of criminals, independent of each other and of other social-structural circumstances, may greatly contribute to the reduction in homicide rates in South and Central American countries, and to the maintenance of low levels of homicides in OECD countries. The Impunity Index reveals that countries that show greater commitment to education and to distribution of income also show greater commitment to

  4. Little Ice Age evidence from a south-central North American ice core, U.S.A.

    USGS Publications Warehouse

    Naftz, D.L.; Klusman, R.W.; Michel, R.L.; Schuster, P.F.; Ready, M.M.; Taylor, H.E.; Yanosky, T.M.; McConnaughey, E.A.

    1996-01-01

    In the past, ice-core records from mid-latitude glaciers in alpine areas of the continental United States were considered to be poor candidates for paleoclimate records because of the influence of meltwater on isotopic stratigraphy. To evaluate the existence of reliable paleoclimatic records, a 160-m ice core, containing about 250 yr of record was obtained from Upper Fremont Glacier, at an altitude of 4000 m in the Wind River Range of south-central North America. The ??18O (SMOW) profile from the core shows a -0.95??? shift to lighter values in the interval from 101.8 to 150 m below the surface, corresponding to the latter part of the Little Ice Age (LIA). Numerous high-amplitude oscillations in the section of the core from 101.8 to 150 m cannot be explained by site-specific lateral variability and probably reflect increased seasonality or better preservation of annual signals as a result of prolonged cooler temperatures that existed in this alpine setting. An abrupt decrease in these large amplitude oscillations at the 101.8-m depth suggests a sudden termination of this period of lower temperatures which generally coincides with the termination of the LIA. Three common features in the ??18O profiles between Upper Fremont Glacier and the better dated Quelccaya Ice Cap cores indicate a global paleoclimate linkage, further supporting the first documented occurrence of the LIA in an ice-core record from a temperate glacier in south-central North America.

  5. Central ventilatory control in the South American lungfish, Lepidosiren paradoxa: contributions of pH and CO(2).

    PubMed

    Amin-Naves, J; Giusti, H; Hoffmann, A; Glass, M L

    2007-07-01

    Lungfish represent a probable sister group to the land vertebrates. Lungfish and tetrapods share features of respiratory control, including central, peripheral and intrapulmonary CO(2) receptors. We investigated whether or not central chemoreceptors in the lungfish, L. paradoxa, are stimulated by CO(2) and/or pH. Ventilation was measured by pneumotachography for diving animals. The fourth cerebral ventricle was equipped with two catheters for superfusion. Initially, two control groups were compared: (1) catheterized animals with no superfusion and (2) animals superfused with mock CSF solutions at pH = 7.45; PCO(2) = 21 mmHg. The two groups had virtually the same ventilation of about 40 ml BTPS kg(-1) h(-1) (P > 0.05). Next, PCO(2) was increased from 21 to 42 mmHg, while pH(CSF) was kept at 7.45, which increased ventilation from 40 to 75 ml BTPS kg(-1) h(-1). Conversely, a decrease of pH(CSF) from 7.45 to 7.20 (PCO(2) = 21 mmHg) increased ventilation to 111 ml BTPS kg(-1) h(-1). Further decreases of pH(CSF) had little effect on ventilation, and the combination of pH(CSF) = 7.10 and PCO(2) = 42 mmHg reduced ventilation to 63 ml BTPS kg(-1) h(-1).

  6. Population genetic structure and historical population dynamics of the South American sea lion, Otaria flavescens, in north-central Patagonia.

    PubMed

    Túnez, Juan I; Cappozzo, Humberto L; Nardelli, Maximiliano; Cassini, Marcelo H

    2010-08-01

    The north-central Patagonian coast is the sea lions most abundant area in Argentina. As occurs along the entire Atlantic coast, the distribution of breeding colonies at this smaller geographical scale is also patchy, showing at least three areas with breeding activity. We study the genetic structure and historical population dynamics of the species in five colonies in this area, analysing a 508 base-pair segment of the D-loop control region. Otaria flavescens showed 10 haplotypes with 12 polymorphic sites. The genealogical relationship between haplotypes revealed a shallow pattern of phylogeographic structure. The analysis of molecular variance showed significant differences between colonies, however, pairwise comparisons only indicate significant differences between a pair of colonies belonging to different breeding areas. The pattern of haplotype differentiation and the mismatch distribution analysis suggest a possible bottleneck that would have occurred 64,000 years ago, followed by a demographic expansion of the three southernmost colonies. Thus, the historical population dynamics of O. flavescens in north-central Patagonia appears to be closely related with the dynamics of the Late Pleistocene glaciations.

  7. A new estimate for present-day Cocos-Caribbean Plate motion: Implications for slip along the Central American Volcanic Arc

    NASA Astrophysics Data System (ADS)

    DeMets, Charles

    Velocities from 153 continuously-operating GPS sites on the Caribbean, North American, and Pacific plates are combined with 61 newly estimated Pacific-Cocos seafloor spreading rates and additional marine geophysical data to derive a new estimate of present-day Cocos-Caribbean plate motion. A comparison of the predicted Cocos-Caribbean direction to slip directions of numerous shallow-thrust subduction earthquakes from the Middle America trench between Costa Rica and Guatemala shows the slip directions to be deflected 10° clockwise from the plate convergence direction, supporting the hypothesis that frequent dextral strike-slip earthquakes along the Central American volcanic arc result from partitioning of oblique Cocos-Caribbean plate convergence. Linear velocity analysis for forearc locations in Nicaragua and Guatemala predicts 14±2 mm yr-1 of northwestward trench-parallel slip of the forearc relative to the Caribbean plate, possibly decreasing in magnitude in El Salvador and Guatemala, where extension east of the volcanic arc complicates the tectonic setting.

  8. The 10 April 2014 Nicaraguan Crustal Earthquake: Evidence of Complex Deformation of the Central American Volcanic Arc

    NASA Astrophysics Data System (ADS)

    Suárez, Gerardo; Muñoz, Angélica; Farraz, Isaac A.; Talavera, Emilio; Tenorio, Virginia; Novelo-Casanova, David A.; Sánchez, Antonio

    2016-10-01

    On 10 April 2014, an M w 6.1 earthquake struck central Nicaragua. The main event and the aftershocks were clearly recorded by the Nicaraguan national seismic network and other regional seismic stations. These crustal earthquakes were strongly felt in central Nicaragua but caused relatively little damage. This is in sharp contrast to the destructive effects of the 1972 earthquake in the capital city of Managua. The differences in damage stem from the fact that the 1972 earthquake occurred on a fault beneath the city; in contrast, the 2014 event lies offshore, under Lake Managua. The distribution of aftershocks of the 2014 event shows two clusters of seismic activity. In the northwestern part of Lake Managua, an alignment of aftershocks suggests a northwest to southeast striking fault, parallel to the volcanic arc. The source mechanism agrees with this right-lateral, strike-slip motion on a plane with the same orientation as the aftershock sequence. For an earthquake of this magnitude, seismic scaling relations between fault length and magnitude predict a sub-surface fault length of approximately 16 km. This length is in good agreement with the extent of the fault defined by the aftershock sequence. A second cluster of aftershocks beneath Apoyeque volcano occurred simultaneously, but spatially separated from the first. There is no clear alignment of the epicenters in this cluster. Nevertheless, the decay of the number of earthquakes beneath Apoyeque as a function of time shows the typical behavior of an aftershock sequence and not of a volcanic swarm. The northeast-southwest striking Tiscapa/Ciudad Jardín and Estadio faults that broke during the 1972 and 1931 Managua earthquakes are orthogonal to the fault where the 10 April earthquake occurred. These orthogonal faults in close geographic proximity show that Central Nicaragua is being deformed in a complex tectonic setting. The Nicaraguan forearc sliver, between the trench and the volcanic arc, moves to the

  9. Dimensions of child sexual abuse before age 15 in three Central American countries: Honduras, El Salvador, and Guatemala.

    PubMed

    Speizer, Ilene S; Goodwin, Mary; Whittle, Lisa; Clyde, Maureen; Rogers, Jennifer

    2008-04-01

    The prevalence of sexual abuse during childhood or adolescence varies depending on the definitions and age categories used. This study examines the first national, population-based data available on child sexual abuse that occurs before age 15 in three countries: El Salvador, Guatemala, and Honduras. This study uses comparable indicators and measures of sexual abuse for the three countries to document the prevalence of abuse, types of perpetrators, and the association of child sexual abuse with recent intimate partner violence. Child sexual abuse was defined as sexual abuse that first occurs before age 15. Nationally representative data from El Salvador, Guatemala, and Honduras were used. In El Salvador, separate questions on forced intercourse and non-penetrative sexual abuse were asked. Bivariate and multivariate analyses were performed using STATA Version 8SE. The prevalence of child sexual abuse varied from 7.8% in Honduras to 6.4% in El Salvador and 4.7% in Guatemala. In all three countries, the overwhelming majority of women who reported child sexual abuse first experienced the abuse before age 11. Perpetrators tended to be a family member, a neighbor, or an acquaintance. Bivariate and multivariate analyses indicated that women who experienced child sexual abuse in Guatemala and Honduras were about two times more likely to be in violent relationships as women who did not experience abuse. This relationship was not significant in multivariate analyses for El Salvador where the prevalence of intimate partner violence was the lowest. Child sexual abuse in Central America is clearly a problem with the prevalence between 5% and 8%. Child sexual abuse can have long-term negative health impacts including exposure to intimate partner violence in adulthood. Programs to prevent abuse and treat victims of child sexual abuse are needed in Central America.

  10. Little ice age evidence from a south-central North American ice core, U.S.A.

    SciTech Connect

    Naftz, D.L.; Klusman, R.W.; Michel, R.L.

    1996-02-01

    In the past, ice-core records from mid-latitude glaciers in alpine areas of the continental United States were considered to be poor candidates for paleoclimate records because of the influence of meltwater on isotopic stratigraphy. To evaluate the existence of reliable paleoclimatic records, a 160-m ice core, containing about 250 yr of record was obtained from Upper Fremont Glacier, at an altitude of 4000 m in the Wind River Range of south-central North America. The {gamma}{sup 18}O (SMOW) profile from the core shows a -0.95{per_thousand} shift to lighter values in the interval from 101.8 to 150 m below the surface, corresponding to the latter part of the Little Ice Age (LIA). Numerous high-amplitude oscillations in the section of the core from 101.8 to 150 m cannot be explained by site-specific lateral variability and probably reflect increased seasonality or better preservation of annual signals as a result of prolonged cooler temperatures that existed in this alpine setting. An abrupt decrease in these large amplitude oscillations at the 101.8-m depth suggests a sudden termination of this period of lower temperatures which generally coincides with the termination of the LIA. Three common features in the {gamma}{sup 18}O profiles between Upper Fremont Glacier and the better dated Quelccaya Ice Cap cores indicate a global paleoclimate linkage, further supporting the first documented occurrence of the LIA in an ice-core record from a temperate glacier in south-central North America.

  11. Partial characterization of Maize rayado fino virus isolates from Ecuador: phylogenetic analysis supports a Central American origin of the virus.

    PubMed

    Chicas, Mauricio; Caviedes, Mario; Hammond, Rosemarie; Madriz, Kenneth; Albertazzi, Federico; Villalobos, Heydi; Ramírez, Pilar

    2007-06-01

    Maize rayado fino virus (MRFV) infects maize and appears to be restricted to, yet widespread in, the Americas. MRFV was previously unreported from Ecuador. Maize plants exhibiting symptoms of MRFV infection were collected at the Santa Catalina experiment station in Quito, Ecuador. RT-PCR reactions were performed on total RNA extracted from the symptomatic leaves using primers specific for the capsid protein (CP) gene and 3' non-translated region of MRFV and first strand cDNA as a template. Nucleotide sequence comparisons to previously sequenced MRFV isolates from other geographic regions revealed 88-91% sequence identity. Phylogenetic trees constructed using Maximum Likelihood, UPGMA, Minimal Evolution, Neighbor Joining, and Maximum Parsimony methods separated the MRFV isolates into four groups. These groups may represent geographic isolation generated by the mountainous chains of the American continent. Analysis of the sequences and the genetic distances among the different isolates suggests that MRFV may have originated in Mexico and/or Guatemala and from there it dispersed to the rest of the Americas.

  12. American cutaneous leishmaniasis in horses from endemic areas in the north-central mesoregion of Paraná state, Brazil.

    PubMed

    Vedovello Filho, D; Jorge, F A; Lonardoni, M V C; Teodoro, U; Silveira, T G V

    2008-04-01

    American cutaneous leishmaniasis (ACL) is an endemic disease in the north-west of Paraná state, Brazil, where it occurs in humans and dogs. Few studies have been undertaken on the occurrence of the disease in other domestic animals and horses. In this study we investigated the infection of horses by Leishmania in ACL-endemic rural areas. Direct agglutination test (DAT) and polymerase chain reaction (PCR) were employed. Fifty-five horses from rural areas in the municipalities of Doutor Camargo, Ourizona, São Jorge do Ivaí, Ivatuba and Santa Fé (Agua do O) were analysed. DAT-detected antibody titres varied from 10 to 640, and 42 (76.3%) animals presented titres > or =20. PCR analyses led to the detection of Leishmania (Viannia) DNA in the blood samples of three (7.1%) of 42 animals. The presence of anti-L. (V.) braziliensis antibodies and Leishmania (Viannia) DNA in horses from endemic areas suggests their participation in the ACL transmission cycle.

  13. Population genetic patterns among social groups of the endangered Central American spider monkey (Ateles geoffroyi) in a human-dominated landscape.

    PubMed

    Hagell, Suzanne; Whipple, Amy V; Chambers, Carol L

    2013-05-01

    SPIDER MONKEYS (GENUS: Ateles) are a widespread Neotropical primate with a highly plastic socioecological strategy. However, the Central American species, Ateles geoffroyi, was recently re-listed as endangered due to the accelerated loss of forest across the subcontinent. There is inconsistent evidence that spider monkey populations could persist when actively protected, but their long-term viability in unprotected, human-dominated landscapes is not known. We analyzed noninvasive genetic samples from 185 individuals in 14 putative social groups on the Rivas Isthmus in southwestern Nicaragua. We found evidence of weak but significant genetic structure in the mitochondrial control region and in eight nuclear microsatellite loci plus negative spatial autocorrelation in Fst and kinship. The overall pattern suggests strong localized mating and at least historical female-biased dispersal, as is expected for this species. Heterozygosity was significantly lower than expected under random mating and lower than that found in other spider monkey populations, possibly reflecting a recent decline in genetic diversity and a threat from inbreeding. We conclude that despite a long history of human disturbance on this landscape, spider monkeys were until recently successful at maintaining gene flow. We consider the recent decline to be further indication of accelerated anthropogenic disturbance, but also of an opportunity to conserve native biodiversity. Spider monkeys are one of many wildlife species in Central America that is threatened by land cover change, and an apt example of how landscape-scale conservation planning could be used to ensure long-term persistence.

  14. Distribution of sulfakinin-like peptides in the central and sympathetic nervous system of the American cockroach, Periplaneta americana (L.) and the field cricket, Teleogryllus commodus (Walker).

    PubMed

    East, P D; Hales, D F; Cooper, P D

    1997-06-01

    We describe the distribution of sulfakinin-like neuropeptides in the central and sympathetic nervous system of the American cockroach Periplaneta americana (L.) (Blattodea) and the field cricket Teleogryllus commodus (Walker) (Othoptera), using an antisulfakinin primary antibody and confocal laser scanning microscopy. We conclude that, in the cockroach, sulfakinin-like material is produced in ten pairs of anterior cells in the pars intercerebralis, as well as two pairs of medial and one major pair of lateral posterior brain cells. This contrasts with findings in other insects, including the cricket, where only the posterior cell groups express sulfakinin-immunoreactive material. Extensive arborization of dendrites containing sulfakinin-like peptides occurs within the neuropile of both species, suggesting a neurotransmitter/neuromodulator function. In the cockroach, there is clear evidence of direct distribution of sulfakinin-like peptides along axons to the foregut tissue, and a plexus of retrocerebral nerves is likely to serve as a neurohaemal release site. Neurohaemal release into the dorsal aorta is also postulated. Sulfakinin-immunoreactive axons do not innervate the hindgut in either cockroaches or crickets. Sulfakinin may function as a gut myotropin in the Blattodea, in addition to functioning as a neurotransmitter within the central nervous system. This latter function appears to be general across insect orders, while the neurohaemal distribution and myotropic activity are restricted to the Blattodea.

  15. Epistatic Interaction of the Melanocortin 1 Receptor and Agouti Signaling Protein Genes Modulates Wool Color in the Brazilian Creole Sheep.

    PubMed

    Hepp, Diego; Gonçalves, Gislene Lopes; Moreira, Gilson Rudinei Pires; de Freitas, Thales Renato Ochotorena

    2016-11-01

    Different pigmentation genes have been associated with color diversity in domestic animal species. The melanocortin 1 receptor (MC1R), agouti signaling protein (ASIP), tyrosinase-related protein 1 (TYRP1), and v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog (KIT) genes are candidate genes responsible for variation in wool color among breeds of sheep. Although the influence of these genes has been described in some breeds, in many others the effect of interactions among genes underlying wool color has not been investigated. The Brazilian Creole sheep is a local breed with a wide variety of wool color, ranging from black to white with several intermediate hues. We analyzed in this study the influence of the genes MC1R, ASIP, TYRP1, and KIT on the control of wool color in this breed. A total of 410 samples were analyzed, including 148 white and 262 colored individuals. The MC1R and ASIP polymorphisms were significantly associated with the segregation of either white or colored wool. The dominant MC1R allele (E(D) p.M73K and p.D121N) was present only in colored animals. All white individuals were homozygous for the MC1R recessive allele (E(+)) and carriers of the duplicated copy of ASIP A gene expression assay showed that only the carrier of the duplicated copy of ASIP produces increased levels in skin, not detectable in the single homozygous copy. These results demonstrate that the epistatic interaction of the genotypes in the MC1R and ASIP gene is responsible for the striking color variation in the Creole breed.

  16. Copy number variation and missense mutations of the agouti signaling protein (ASIP) gene in goat breeds with different coat colors.

    PubMed

    Fontanesi, L; Beretti, F; Riggio, V; Gómez González, E; Dall'Olio, S; Davoli, R; Russo, V; Portolano, B

    2009-01-01

    In goats, classical genetic studies reported a large number of alleles at the Agouti locus with effects on coat color and pattern distribution. From these early studies, the dominant A(Wt) (white/tan) allele was suggested to cause the white color of the Saanen breed. Here, we sequenced the coding region of the goat ASIP gene in 6 goat breeds (Girgentana, Maltese, Derivata di Siria, Murciano-Granadina, Camosciata delle Alpi, and Saanen), with different coat colors and patterns. Five single nucleotide polymorphisms (SNPs) were identified, 3 of which caused missense mutations in conserved positions of the cysteine-rich carboxy-terminal domain of the protein (p.Ala96Gly, p.Cys126Gly, and p.Val128Gly). Allele and genotype frequencies suggested that these mutations are not associated or not completely associated with coat color in the investigated goat breeds. Moreover, genotyping and sequencing results, deviation from Hardy-Weinberg equilibrium, as well as allele copy number evaluation from semiquantitative fluorescent multiplex PCR, indicated the presence of copy number variation (CNV) in all investigated breeds. To confirm the presence of CNV and evaluate its extension, we applied a bovine-goat cross-species array comparative genome hybridization (aCGH) experiment using a custom tiling array based on bovine chromosome 13. aCGH results obtained for 8 goat DNA samples confirmed the presence of CNV affecting a region of less that 100 kb including the ASIP and AHCY genes. In Girgentana and Saanen breeds, this CNV might cause the A(Wt) allele, as already suggested for a similar structural mutation in sheep affecting the ASIP and AHCY genes, providing evidence for a recurrent interspecies CNV. However, other mechanisms may also be involved in determining coat color in these 2 breeds.

  17. Agouti revisited: transcript quantification of the ASIP gene in bovine tissues related to protein expression and localization.

    PubMed

    Albrecht, Elke; Komolka, Katrin; Kuzinski, Judith; Maak, Steffen

    2012-01-01

    Beside its role in melanogenesis, the agouti signaling protein (ASIP) has been related to obesity. The potentially crucial role in adipocyte development makes it a tempting candidate for economic relevant, fat related traits in farm animals. The objective of our study was to characterize the mRNA expression of different ASIP transcripts and of putative targets in different bovine tissues, as well as to study consequences on protein abundance and localization. ASIP mRNA abundance was determined by RT-qPCR in adipose and further tissues of cattle representing different breeds and crosses. ASIP mRNA was up-regulated more than 9-fold in intramuscular fat of Japanese Black cattle compared to Holstein (p<0.001). Further analyses revealed that a transposon-derived transcript was solely responsible for the increased ASIP mRNA abundance. This transcript was observed in single individuals of different breeds indicating a wide spread occurrence of this insertion at the ASIP locus in cattle. The protein was detected in different adipose tissues, skin, lung and liver, but not in skeletal muscle by Western blot with a bovine-specific ASIP antibody. However, the protein abundance was not related to the observed ASIP mRNA over-expression. Immuno-histochemical analyses revealed a putative nuclear localization of ASIP additionally to the expected cytosolic signal in different cell types. The expression of melanocortin receptors (MCR) 1 to 5 as potential targets for ASIP was analyzed by RT-PCR in subcutaneous fat. Only MC1R and MC4R were detected indicating a similar receptor expression like in human adipose tissue. Our results provide evidence for a widespread expression of ASIP in bovine tissues at mRNA and, for the first time, at protein level. ASIP protein is detectable in adipocytes as well as in further cells of adipose tissue. We generated a basis for a more detailed investigation of ASIP function in peripheral tissues of various mammalian species.

  18. Long-Term Effects of (-)-Epigallocatechin Gallate (EGCG) on Pristane-Induced Arthritis (PIA) in Female Dark Agouti Rats.

    PubMed

    Leichsenring, Anna; Bäcker, Ingo; Furtmüller, Paul G; Obinger, Christian; Lange, Franziska; Flemmig, Jörg

    2016-01-01

    Rheumatoid arthritis (RA)--a widespread chronic inflammatory disease in industrialized countries--is characterized by a persistent and progressive joint destruction. The chronic pro-inflammatory state results from a mutual activation of the innate and the adaptive immune system, while the exact pathogenesis mechanism is still under discussion. New data suggest a role of the innate immune system and especially polymorphonuclear granulocytes (PMNs, neutrophils) not only during onset and the destructive phase of RA but also at the chronification of the disease. Thereby the enzymatic activity of myeloperoxidase (MPO), a peroxidase strongly abundant in neutrophils, may be important: While its peroxidase activity is known to contribute to cartilage destruction at later stages of RA the almost MPO-specific oxidant hypochlorous acid (HOCl) is also discussed for certain anti-inflammatory effects. In this study we used pristane-induced arthritis (PIA) in Dark Agouti rats as a model for the chronic course of RA in man. We were able to shown that a specific detection of the HOCl-producing MPO activity provides a sensitive new marker to evaluate the actual systemic inflammatory status which is only partially detectable by the evaluation of clinical symptoms (joint swelling and redness measurements). Moreover, we evaluated the long-term pharmacological effect of the well-known anti-inflammatory flavonoid epigallocatechin gallate (EGCG). Thereby only upon early and continuous oral application of this polyphenol the arthritic symptoms were considerably diminished both in the acute and in the chronic phase of the disease. The obtained results were comparable to the treatment control (application of methotrexate, MTX). As revealed by stopped-flow kinetic measurements, EGCG may regenerate the HOCl-production of MPO which is known to be impaired at chronic inflammatory diseases like RA. It can be speculated that this MPO activity-promoting effect of EGCG may contribute to the

  19. Acute and long-term effects of a single dose of MDMA on aggression in Dark Agouti rats.

    PubMed

    Kirilly, Eszter; Benko, Anita; Ferrington, Linda; Ando, Romeo D; Kelly, Paul A T; Bagdy, Gyorgy

    2006-02-01

    MDMA causes selective depletion of serotonergic terminals in experimental animals and the consequent decrease in synaptic 5-HT may, inter alia, increase impulsivity. To study the effects of MDMA upon brain function, the behaviour of male Dark Agouti rats exposed to MDMA (15 mg/kg i.p.), two 5-HT1B agonists (CGS-12066A and CP-94,253, both 5 mg/kg i.p.) or saline were investigated in the resident-intruder test. Studies were performed in drug-naive rats and also in rats exposed to MDMA (15 mg/kg i.p.) 21 d earlier. In parallel experiments the functional neuroanatomy of MDMA effects were assessed using 2-deoxyglucose imaging of local cerebral metabolic rate of glucose utilization (LCMRGlu) and neurotoxicity was assessed by measuring [3H]paroxetine binding. There was no significant difference in aggressive behaviour (biting, boxing, wrestling and their latencies) between drug-naive rats and rats previously exposed to MDMA 21 d earlier, despite reduced social behaviour, decreased LCMRGlu in several brain areas involved in aggression, and reductions in paroxetine binding by 30-60% in the forebrain. CGS-12066A, CP-94,253 and acute MDMA produced marked decreases in aggressive behaviours, especially in biting, boxing and kicking found in drug-naive rats. In animals previously exposed to the drug, acute anti-aggressive effects of MDMA were, in general, preserved as were MDMA-induced increases in LCMRGlu. Our studies provide evidence that in the resident-intruder test, where social isolation is a requirement, aggressive behaviour and acute anti-aggressive effects of MDMA and 5-HT1B receptor agonists remain intact 3 wk after a single dose of the drug despite significant damage to the serotonergic system.

  20. Proopiomelanocortin, agouti-related protein, and leptin in human cerebrospinal fluid: correlations with body weight and adiposity

    PubMed Central

    Page-Wilson, Gabrielle; Meece, Kana; White, Anne; Rosenbaum, Michael; Leibel, Rudolph L.; Smiley, Richard

    2015-01-01

    Leptin and its neuronal targets, which produce proopiomelanocortin (POMC) and agouti-related protein (AgRP), regulate energy balance. This study characterized leptin, POMC, and AgRP in the cerebrospinal fluid (CSF) of 47 healthy human subjects, 23 lean and 24 overweight/obese (OW/OB), as related to BMI, adiposity, plasma leptin, soluble leptin receptor (s-OB-R), and insulin. POMC was measured since the POMC prohormone is the predominant POMC peptide in CSF and correlates with hypothalamic POMC in rodents. Plasma AgRP was similarly characterized. CSF leptin was 83-fold lower than in plasma and correlated strongly with BMI, body fat, and insulin. The relative amount of leptin transported into CSF declined with increasing BMI, ranging from 4.5 to 0.52%, consistent with a saturable transport mechanism. CSF sOB-R was 78-fold lower than in plasma and correlated negatively with plasma and CSF leptin. CSF POMC was higher in lean vs. OW/OB subjects (P < 0.001) and correlated negatively with CSF leptin (r = −0.60, P < 0.001) and with plasma leptin, insulin, BMI, and adiposity. CSF AgRP was not different in lean vs. OW/OB; however, plasma AgRP was higher in lean subjects (P = 0.001) and correlated negatively with BMI, adiposity, leptin, insulin, and HOMA (P < 0.005). Thus, CSF measurements may provide useful biomarkers for brain leptin and POMC activity. The striking negative correlation between CSF leptin and POMC could be secondary to leptin resistance and/or neuronal changes associated with obesity but may also indicate that POMC plays a primary role in regulating body weight and adiposity. The role of plasma AgRP as a neuroendocrine biomarker deserves further study. PMID:26152765

  1. Function of neuropeptide Y and agouti-related protein at weaning: relation to corticosterone, dietary carbohydrate and body weight.

    PubMed

    Leibowitz, Sarah F; Sepiashvili, Kate; Akabayashi, Akira; Karatayev, Olga; Davydova, Zoya; Alexander, Jesline T; Wang, Jian; Chang, Guo-Qing

    2005-03-02

    Neuropeptide Y (NPY) and agouti-related protein (AgRP), potent stimulants of feeding, have been linked in adult rats to both corticosterone (CORT) and dietary carbohydrate. To understand the significance of this relationship early in life, measurements were taken of these parameters at different ages around weaning, in rats given a choice of macronutrient diets or maintained on a carbohydrate-rich diet. The results demonstrate that, in both male and female rat pups, the expression and production of NPY and AgRP in the arcuate nucleus (ARC) peak on postnatal day 21 (P21), compared to P15 before weaning and P27 after weaning. These elevated levels of peptide were associated with peak levels of CORT and glucose and also a strong, natural preference for carbohydrate at weaning, which accounted for 55-65% of the pups' total diet. In subgroups defined by their body weight at these stages, rats with as little as 4% lower body weight (compared to higher weight pups) had 30-60% greater expression of NPY and AgRP in the ARC and elevated levels of CORT, with no difference in leptin or insulin. This response was significantly more pronounced at P21 than at P15 or P27. The importance of carbohydrate during this stage was suggested by additional results showing elevated NPY expression, CORT levels, body weight and inguinal fat pad weights in P27 pups raised on a 65% carbohydrate diet vs. 45% carbohydrate. These results suggest that hypothalamic NPY and AgRP, together with CORT, have glucoregulatory as well as feeding stimulatory functions that help mediate the transition from suckling of a fat-rich diet to independent feeding of a carbohydrate-rich diet. During this critical period, the carbohydrate together with the peptides and CORT provide the important signals, including elevated glucose, that promote de novo lipogenesis and enable weanling animals to survive periods of food deprivation.

  2. Hypothalamic Agouti-Related Peptide mRNA is Elevated During Natural and Stress-Induced Anorexia.

    PubMed

    Dunn, I C; Wilson, P W; D'Eath, R B; Boswell, T

    2015-09-01

    As part of their natural lives, animals can undergo periods of voluntarily reduced food intake and body weight (i.e. animal anorexias) that are beneficial for survival or breeding, such as during territorial behaviour, hibernation, migration and incubation of eggs. For incubation, a change in the defended level of body weight or 'sliding set point' appears to be involved, although the neural mechanisms reponsible for this are unknown. We investigated how neuropeptide gene expression in the arcuate nucleus of the domestic chicken responded to a 60-70% voluntary reduction in food intake measured both after incubation and after an environmental stressor involving transfer to unfamiliar housing. We hypothesised that gene expression would not change in these circumstances because the reduced food intake and body weight represented a defended level in birds with free access to food. Unexpectedly, we observed increased gene expression of the orexigenic peptide agouti-related peptide (AgRP) in both incubating and transferred animals compared to controls. Also pro-opiomelanocortin (POMC) mRNA was higher in incubating hens and significantly increased 6 days after exposure to the stressor. Conversely expression of neuropeptide Y and cocaine- and amphetamine-regulated transcript gene was unchanged in both experimental situations. We conclude that AgRP expression remains sensitive to the level of energy stores during natural anorexias, which is of adaptive advantage, although its normal orexigenic effects are over-ridden by inhibitory signals. In the case of stress-induced anorexia, increased POMC may contribute to this inhibitory role, whereas, for incubation, reduced feeding may also be associated with increased expression in the hypothalamus of the anorexigenic peptide vasoactive intestinal peptide.

  3. The diversity of the Chagas parasite, Trypanosoma cruzi, infecting the main Central American vector, Triatoma dimidiata, from Mexico to Colombia.

    PubMed

    Dorn, Patricia L; McClure, Annie G; Gallaspy, Meghan D; Waleckx, Etienne; Woods, Adrienne S; Monroy, Maria Carlota; Stevens, Lori

    2017-09-01

    Little is known about the strains of Trypanosoma cruzi circulating in Central America and specifically in the most important vector in this region, Triatoma dimidiata. Approximately six million people are infected with T. cruzi, the causative agent of Chagas disease, which has the greatest negative economic impact and is responsible for ~12,000 deaths annually in Latin America. By international consensus, strains of T. cruzi are divided into six monophyletic clades called discrete typing units (DTUs TcI-VI) and a seventh DTU first identified in bats called TcBat. TcI shows the greatest geographic range and diversity. Identifying strains present and diversity within these strains is important as different strains and their genotypes may cause different pathologies and may circulate in different localities and transmission cycles, thus impacting control efforts, treatment and vaccine development. To determine parasite strains present in T. dimidiata across its geographic range from Mexico to Colombia, we isolated abdominal DNA from T. dimidiata and determined which specimens were infected with T. cruzi by PCR. Strains from infected insects were determined by comparing the sequence of the 18S rDNA and the spliced-leader intergenic region to typed strains in GenBank. Two DTUs were found: 94% of infected T. dimidiata contained TcI and 6% contained TcIV. TcI exhibited high genetic diversity. Geographic structure of TcI haplotypes was evident by Principal Component and Median-Joining Network analyses as well as a significant result in the Mantel test, indicating isolation by distance. There was little evidence of association with TcI haplotypes and host/vector or ecotope. This study provides new information about the strains circulating in the most important Chagas vector in Central America and reveals considerable variability within TcI as well as geographic structuring at this large geographic scale. The lack of association with particular vectors/hosts or ecotopes

  4. Snake venomics of the Central American rattlesnake Crotalus simus and the South American Crotalus durissus complex points to neurotoxicity as an adaptive paedomorphic trend along Crotalus dispersal in South America.

    PubMed

    Calvete, Juan J; Sanz, Libia; Cid, Pedro; de la Torre, Pilar; Flores-Díaz, Marietta; Dos Santos, M Cristina; Borges, Adolfo; Bremo, Adolfo; Angulo, Yamileth; Lomonte, Bruno; Alape-Girón, Alberto; Gutiérrez, José María

    2010-01-01

    We report a comparative venomic and antivenomic characterization of the venoms of newborn and adult specimens of the Central American rattlesnake, Crotalus simus, and of the subspecies cumanensis, durissus, ruruima, and terrificus of South American Crotalus durissus. Neonate and adult C. simus share about 50% of their venom proteome. The venom proteome of 6-week-old C. simus is predominantly made of the neurotoxic heterodimeric phospholipase A(2) (PLA(2) crotoxin) (55.9%) and serine proteinases (36%), whereas snake venom Zn(2+)-metalloproteinases (SVMPs), exclusively of class PIII, represent only 2% of the total venom proteins. In marked contrast, venom from adult C. simus comprises toxins from 7 protein families. A large proportion (71.7%) of these toxins are SVMPs, two-thirds of which belong to the PIII class. These toxin profiles correlate well with the overall biochemical and pharmacological features of venoms from adult (hemorrhagic) and newborn (neurotoxic) C. simus specimens. The venoms of the South American Crotalus subspecies belong to one of two distinct phenotypes. C. d. cumanensis exhibits high levels of SVMPs and low lethal potency (LD(50)), whereas C. d. subspecies terrificus, ruruima, and durissus have low SVMP activity and high neurotoxicity to mice. Their overall toxin compositions explain the outcome of envenomation by these species. Further, in all C. simus and C. durissus venoms, the concentration of neurotoxins (crotoxin and crotamine) is directly related with lethal activity, whereas lethality and metalloproteinase activity show an inverse relationship. The similar venom toxin profiles of newborn C. simus and adult C. durissus terrificus, ruruima, and durissus subspecies strongly suggests that the South American taxa have retained juvenile venom characteristics in the adult form (paedomorphism) along their North-South stepping-stone dispersal. The driving force behind paedomorphism is often competition or predation pressure. The increased

  5. Evaluation of Minerals, Phytochemical Compounds and Antioxidant Activity of Mexican, Central American, and African Green Leafy Vegetables.

    PubMed

    Jiménez-Aguilar, Dulce M; Grusak, Michael A

    2015-12-01

    The green leafy vegetables Cnidoscolus aconitifolius and Crotalaria longirostrata are native to Mexico and Central America, while Solanum scabrum and Gynandropsis gynandra are native to Africa. They are consumed in both rural and urban areas in those places as a main food, food ingredient or traditional medicine. Currently, there is limited information about their nutritional and phytochemical composition. Therefore, mineral, vitamin C, phenolic and flavonoid concentration, and antioxidant activity were evaluated in multiple accessions of these leafy vegetables, and their mineral and vitamin C contribution per serving was calculated. The concentrations of Ca, K, Mg and P in these leafy vegetables were 0.82-2.32, 1.61-7.29, 0.61-1.48 and 0.27-1.44 mg/g fresh weight (FW), respectively. The flavonoid concentration in S. scabrum accessions was up to 1413 μg catechin equivalents/g FW, while the highest antioxidant activities were obtained in C. longirostrata accessions (52-60 μmol Trolox equivalents/g FW). According to guidelines established by the US Food and Drug Administration, a serving size (30 g FW) of C. longirostrata would be considered an excellent source of Mo (20 % or more of the daily value), and a serving of any of these green leafy vegetables would be an excellent source of vitamin C. Considering the importance of the minerals, phytochemicals and antioxidants in human health and their presence in these indigenous green leafy vegetables, efforts to promote their consumption should be implemented.

  6. Pathology, physiologic parameters, tissue contaminants, and tissue thiamine in morbid and healthy central Florida adult American alligators (Alligator mississippiensis)

    USGS Publications Warehouse

    Honeyfield, D.C.; Ross, J.P.; Carbonneau, D.A.; Terrell, S.P.; Woodward, A.R.; Schoeb, T.R.; Perceval, H.F.; Hinterkopf, J.P.

    2008-01-01

    An investigation of adult alligator (Alligator mississippiensis) mortalities in Lake Griffin, central Florida, was conducted from 1998-2004. Alligator mortality was highest in the months of April and May and annual death count peaked in 2000. Bacterial pathogens, heavy metals, and pesticides were not linked with the mortalities. Blood chemistry did not point to any clinical diagnosis, although differences between impaired and normal animals were noted. Captured alligators with signs of neurologic impairment displayed unresponsive and uncoordinated behavior. Three of 21 impaired Lake Griffin alligators were found to have neural lesions characteristic of thiamine deficiency in the telencephalon, particularly the dorsal ventricular ridge. In some cases, lesions were found in the thalamus, and parts of the midbrain. Liver and muscle tissue concentrations of thiamine (vitamin B"1) were lowest in impaired Lake Griffin alligators when compared to unimpaired alligators or to alligators from Lake Woodruff. The consumption of thiaminase-positive gizzard shad (Dorosoma cepedianum) is thought to have been the cause of the low tissue thiamine and resulting mortalities. ?? Wildlife Disease Association 2008.

  7. Isolation and structure elucidation of secondary metabolites in Central and South American Calea species and their biochemical systematic implications

    SciTech Connect

    Ober, A.G.

    1984-01-01

    Fourteen species of the genus Calea (Family Compositae, Tribe Heliantheae) from Central and northern South America, including the type species for the genus, were investigated chemically to determine their secondary metabolites. The taxa studied were C. leptocephala Blake, C. megacephala Rob, and Greenm., and C. trichotoma B. Smith from Mexico, C. prunifolia Kunth (syn. C. pittieri) from Costa Rica, C. prunifolia Kunth from Panama, C. jamaicensis L. from Jamaica, and the Venezuelan species C. berteriana DC., C. divaricata Benthem, C. oliverii Rob. and Greenm., C. prunifolia Kunth, C. septuplinervia Hieron., C. solidaginea Kunth, and C. subcordata Kunth. The chemical investigation of these Calea species, undertaken as part of biochemical systematic study, has resulted in the isolation of 83 compounds, of which 38 are new natural products. The isolated compounds were represented by a dioxin derivative, 3 benzofuranes, 5 chromenes, 12 flavones, and 62 sesquiterpene lactones. The structures of the new compounds were established by chemical and spectroscopic methods. These methods included MS, IR, UV, and CD, /sup 1/H NMR, /sup 13/C NMR, and single crystal x-ray diffraction analysis.

  8. Pathology, physiologic parameters, tissue contaminants, and tissue thiamine in morbid and healthy central Florida adult American alligators (Alligator mississippiensis).

    PubMed

    Honeyfield, Dale C; Ross, J Perran; Carbonneau, Dwayne A; Terrell, Scott P; Woodward, Allan R; Schoeb, Trenton R; Perceval, H Franklin; Hinterkopf, Joy P

    2008-04-01

    An investigation of adult alligator (Alligator mississippiensis) mortalities in Lake Griffin, central Florida, was conducted from 1998-2004. Alligator mortality was highest in the months of April and May and annual death count peaked in 2000. Bacterial pathogens, heavy metals, and pesticides were not linked with the mortalities. Blood chemistry did not point to any clinical diagnosis, although differences between impaired and normal animals were noted. Captured alligators with signs of neurologic impairment displayed unresponsive and uncoordinated behavior. Three of 21 impaired Lake Griffin alligators were found to have neural lesions characteristic of thiamine deficiency in the telencephalon, particularly the dorsal ventricular ridge. In some cases, lesions were found in the thalamus, and parts of the midbrain. Liver and muscle tissue concentrations of thiamine (vitamin B(1)) were lowest in impaired Lake Griffin alligators when compared to unimpaired alligators or to alligators from Lake Woodruff. The consumption of thiaminase-positive gizzard shad (Dorosoma cepedianum) is thought to have been the cause of the low tissue thiamine and resulting mortalities.

  9. Rapid development of semistarvation-induced hyperactivity in Dark Agouti rats. Excessive wheel running and effect of 3,4-methylenedioxymethamphetamine (MDMA).

    PubMed

    Vidal, Pedro; Pérez-Padilla, Ángeles; Pellón, Ricardo

    2013-02-01

    Clinical studies have found that patients with anorexia develop high activity levels. These data suggest a possible implication of activity in the aetiology of anorexia and are in line with findings obtained in animals during experimental procedures to model interactions between activity and weight loss. Activity-based anorexia (ABA) and semistarvation-induced hyperactivity (SIH) develop when laboratory rats have food access restricted to a single period in the day and are given free access to an activity wheel. This experiment sought to show the effect on weight loss of the excessive activity normally seen in Dark Agouti rats and of hyperactivity induced by 3,4-methylenedioxymethamphetamine (MDMA). To this end, 32 female rats of the Dark Agouti strain were selected and divided into four groups in accordance with a 2 × 2 factorial design, in which one factor was treatment (saline or MDMA) and the other was access or lack of access to an activity wheel. Animals with wheel running access displayed a marked increase in running combined with accelerated weight loss. Although pharmacological treatment resulted in no observable effect on weight loss, rats treated with 12.5mg/kg MDMA generally registered more wheel running than did those treated with saline. Analysis of data on the temporal distribution of wheel running revealed an alteration in circadian activity patterns as a consequence of MDMA. These results, by showing a general high level of wheel running in Dark Agouti rats, once again emphasise the close relationship between activity and weight loss in the development of SIH and related phenomena such as ABA.

  10. Variability in Central American rainfall amount and seasonality over the past four centuries: evidence from a monthly resolved Belizean stalagmite

    NASA Astrophysics Data System (ADS)

    Ridley, H. E.; Asmerom, Y.; Baldini, J. U.; Aquino, V. V.; Breitenbach, S. F.; Polyak, V. J.; Prufer, K. M.; Kennett, D. J.; Culleton, B. J.; Marwan, N.; Lechleitner, F.; Macphearson, C. G.; Haug, G. H.; Awe, J.

    2013-12-01

    Climate variability in the tropical Atlantic is notoriously complex and has been poorly characterised beyond the instrumental record. Climate fluctuations in this region are linked to global temperatures, making understanding past variability critical in light of the scenario of unprecedented recent warming. High resolution palaeoclimate records provide essential information on climate fluctuations and development on annual to centennial scales, which will be fundamental in understanding the complex climate evolution of the region during the last 2000 years. We have generated a 453 year long, precisely-dated, monthly-resolved oxygen and carbon stable isotope dataset from stalagmite YOK-G from Yok Balum Cave, southern Belize. Annual δ13C cycles, which are clear through much of the record, provide sub-annual chronological control (i.e., year and season of deposition) and facilitate the reconstruction of palaeoseasonality. Stalagmite δ18O suggests a significant positive correlation with northern hemisphere temperature (NHT), most likely via interactions of ITCZ position and regional temperature. A close link also exists with cave records from China and the Caribbean region. The δ13C record is interpreted as directly reflecting effective rainfall, and indicates that during the pre-industrial period high NHT resulted in increased boreal summer rainfall. During the Modern Warm Period (post 1850), a significant decrease in wet and dry season rainfall and seasonality occurred, possibly due to a more southerly boreal summer ITCZ position and enhanced evapotranspiration in response to shifts in greenhouse gas (GHG) moderated pressure gradients. The YOK-G dataset suggests that both rainfall amount and seasonality in Central America are decreasing and that future scenarios of GHG induced global warming may lead further rainfall reductions in the region.

  11. Clouds, Wind and the Biogeography of Central American Cloud Forests: Remote Sensing, Atmospheric Modeling, and Walking in the Jungle

    NASA Astrophysics Data System (ADS)

    Lawton, R.; Nair, U. S.

    2011-12-01

    Cloud forests stand at the core of the complex of montane ecosystems that provide the backbone to the multinational Mesoamerican Biological Corridor, which seeks to protect a biodiversity conservation "hotspot" of global significance in an area of rapidly changing land use. Although cloud forests are generally defined by frequent and prolonged immersion in cloud, workers differ in their feelings about "frequent" and "prolonged", and quantitative assessments are rare. Here we focus on the dry season, in which the cloud and mist from orographic cloud plays a critical role in forest water relations, and discuss remote sensing of orographic clouds, and regional and atmospheric modeling at several scales to quantitatively examine the distribution of the atmospheric conditions that characterize cloud forests. Remote sensing using data from GOES reveals diurnal and longer scale patterns in the distribution of dry season orographic clouds in Central America at both regional and local scales. Data from MODIS, used to calculate the base height of orographic cloud banks, reveals not only the geographic distributon of cloud forest sites, but also striking regional variation in the frequency of montane immersion in orographic cloud. At a more local scale, wind is known to have striking effects on forest structure and species distribution in tropical montane ecosystems, both as a general mechanical stress and as the major agent of ecological disturbance. High resolution regional atmospheric modeling using CSU RAMS in the Monteverde cloud forests of Costa Rica provides quantitative information on the spatial distribution of canopy level winds, insight into the spatial structure and local dynamics of cloud forest communities. This information will be useful in not only in local conservation planning and the design of the Mesoamerican Biological Corridor, but also in assessments of the sensitivity of cloud forests to global and regional climate changes.

  12. Central Adiposity and Other Anthropometric Factors in Relation to Risk of Macrosomia in an African American population

    PubMed Central

    Li, Se; Rosenberg, Lynn; Palmer, Julie R.; Phillips, Ghasi S.; Heffner, Linda J.; Wise, Lauren A.

    2012-01-01

    Previous studies have consistently identified maternal obesity and gestational weight gain as risk factors for macrosomia, but little is known about the effects of central adiposity and body fat distribution. Using self-reported data from the Black Women's Health Study (BWHS), a large follow-up study of U.S. black women, we examined the risk of macrosomia in relation to prepregnancy waist circumference, prepregnancy waist-to-hip ratio, prepregnancy body mass index (BMI), and gestational weight gain. During 1995–2003, BWHS participants ages 21 to 44 years delivered 6,687 full-term singleton births (gestational age >37 weeks). We compared mothers of 691 infants weighing ≥4000g with mothers of 5,996 infants weighing <4000g. Generalized estimating equation models that accounted for more than one birth per mother were used to estimate multivariable odds ratios (OR) and 95% confidence intervals (CI). Independent of prepregnancy BMI, prepregnancy waist circumference was positively associated with risk of macrosomia (OR=1.58, 95% CI 1.07–2.32, for ≥35.0 vs. <27.0 inches (≥88.9 vs. <68.6 cm); P-trend= 0.04). As expected, prepregnancy BMI was also positively associated with macrosomia (OR=1.74, 95% CI 1.25–2.41 for BMI ≥35.0 vs. 18.5–24.9 kg/m2). Gestational weight gain above the amount recommended by the 2009 Institute of Medicine report was associated with an increased risk of macrosomia and the association was present in each category of prepregnancy BMI (18.5–24.9, 25.0–29.9, and ≥30.0 kg/m2; P-trend<0.001). Our data suggest that overall obesity, high gestational weight gain, and high waist circumference are independent risk factors for macrosomia among U.S. black women. PMID:23505184

  13. Central adiposity and other anthropometric factors in relation to risk of macrosomia in an African American population.

    PubMed

    Li, Se; Rosenberg, Lynn; Palmer, Julie R; Phillips, Ghasi S; Heffner, Linda J; Wise, Lauren A

    2013-01-01

    Previous studies have consistently identified maternal obesity and gestational weight gain (GWG) as risk factors for macrosomia, but little is known about the effects of central adiposity and body fat distribution. Using self-reported data from the Black Women's Health Study (BWHS), a large follow-up study of US black women, we examined the risk of macrosomia in relation to prepregnancy waist circumference, prepregnancy waist-to-hip ratio (WHR), prepregnancy BMI, and GWG. During 1995-2003, BWHS participants ages 21-44 years delivered 6,687 full-term singleton births (gestational age >37 weeks). We compared mothers of 691 infants weighing ≥ 4,000 g with mothers of 5,996 infants weighing <4,000 g. Generalized estimating equation models (GEE) that accounted for more than one birth per mother were used to estimate multivariable odds ratios (OR) and 95% confidence intervals (CI). Independent of prepregnancy BMI, prepregnancy waist circumference was positively associated with risk of macrosomia (OR = 1.58, 95% CI: 1.07-2.32, for ≥ 35.0 vs. <27.0 inches (≥ 88.9 vs. <68.6 cm); P trend = 0.04). As expected, prepregnancy BMI was also positively associated with macrosomia (OR = 1.74, 95% CI: 1.25-2.41 for BMI ≥ 35.0 vs. 18.5-24.9 kg m(-2)). GWG above the amount recommended by the 2009 Institute of Medicine report was associated with an increased risk of macrosomia and the association was present in each category of prepregnancy BMI (18.5-24.9, 25.0-29.9, and ≥ 30.0 kg m(-2); P trend <0.001). Our data suggest that overall obesity, high GWG, and high waist circumference are independent risk factors for macrosomia among US black women. Copyright © 2013 The Obesity Society.

  14. The establishment of Central American migratory corridors and the biogeographic origins of seasonally dry tropical forests in Mexico

    PubMed Central

    Willis, Charles G.; Franzone, Brian F.; Xi, Zhenxiang; Davis, Charles C.

    2014-01-01

    Biogeography and community ecology can mutually illuminate the formation of a regional species pool or biome. Here, we apply phylogenetic methods to a large and diverse plant clade, Malpighiaceae, to characterize the formation of its species pool in Mexico, and its occupancy of the seasonally dry tropical forest (SDTF) biome that occurs there. We find that the ~162 species of Mexican Malpighiaceae represent ~33 dispersals from South America beginning in the Eocene and continuing until the Pliocene (~46.4–3.8 Myr). Furthermore, dispersal rates between South America and Mexico show a significant six-fold increase during the mid-Miocene (~23.9 Myr). We hypothesize that this increase marked the availability of Central America as an important corridor for Neotropical plant migration. We additionally demonstrate that this high rate of dispersal contributed substantially more to the phylogenetic diversity of Malpighiaceae in Mexico than in situ diversification. Finally, we show that most lineages arrived in Mexico pre-adapted with regard to one key SDTF trait, total annual precipitation. In contrast, these lineages adapted to a second key trait, precipitation seasonality, in situ as mountain building in the region gave rise to the abiotic parameters of extant SDTF. The timing of this in situ adaptation to seasonal precipitation suggests that SDTF likely originated its modern characteristics by the late Oligocene, but was geographically more restricted until its expansion in the mid-Miocene. These results highlight the complex interplay of dispersal, adaptation, and in situ diversification in the formation of tropical biomes. Our results additionally demonstrate that these processes are not static, and their relevance can change markedly over evolutionary time. This has important implications for understanding the origin of SDTF in Mexico, but also for understanding the temporal and spatial origin of biomes and regional species pools more broadly. PMID:25566320

  15. Purification of peptides with differential cytolytic activities from the skin secretions of the Central American frog, Lithobates vaillanti (Ranidae).

    PubMed

    Conlon, J Michael; Raza, Haider; Coquet, Laurent; Jouenne, Thierry; Leprince, Jérôme; Vaudry, Hubert; King, Jay D

    2009-08-01

    Peptide-based defenses of ranid frogs from Mexico and Central America have been studied in much less detail than those from North America. Peptides belonging to the brevinin-1 (5 peptides), palustrin-2 (1 peptide), and ranatuerin-2 (3 peptides) families were isolated from norepinephrine-stimulated skin secretions of the Costa Rican frog, Lithobates vaillanti (Ranidae) and characterized structurally. Brevinin-1VLa (FLGAIAGVAAKFLPKVFCFITKKC) and brevinin-1VLc (FLPVIASVAAKVLPK VFCFITKKC) showed particularly high growth-inhibitory potency (MIC < or =3 microM) against a Gram-positive microorganism Staphylococcus aureus and the opportunistic yeast pathogen Candida albicans and potent cytolytic activity (LC(50)< or =8 microM) against both human erythrocytes and HepG2 hepatoma-derived cells. The peptides were also active against a Gram-negative microorganism Escherichia coli (MIC< or =50 microM). Substitutions in brevinin-1VLd (Lys(11) --> Asn) and brevinin-1VLe (Lys(11) --> Ser) that decrease cationicity result in loss of activity against E. coli. Ranatuerin-2VLb (GIMDTIKGAAKDLAGQLLDKLKCKITKC) showed relatively weak antimicrobial activity (MIC> or =75 microM) but selective cytolytic activity against HepG2 tumor cells (LC(50)=30 microM) compared with erythrocytes (LC(50)>200 microM). In addition, a dodecapeptide (RICYAMWIPYPC) were isolated from the secretions that were devoid of antimicrobial activity. This component contains an Ala-Met bond that constitutes the scissile bond in the selective elastase inhibitor, elafin but the peptide did not inhibit pancreatic elastase at concentrations up to 100 microM.

  16. Convective Distribution of Tropospheric Ozone and Tracers in the Central American ITCZ Region: Evidence from Observations During TC4

    NASA Technical Reports Server (NTRS)

    Avery, Melody; Twohy, Cynthia; MCabe, David; Joiner, Joanna; Severance, Kurt; Atlas, Eliot; Blake, Donald; Bui, T. P.; Crounse, John; Dibb, Jack; Diskin, Glenn; Lawson, Paul; McGill, Matthew; Rogers, David; Sachse, Glen; Scheuer, Eric; Thompson, Anne M.; Trepte, Charles; Wennberg, Paul; Ziemke, Jerald

    2010-01-01

    During the Tropical Composition, Clouds and Climate Coupling (TC4) experiment that occurred in July and August of 2007, extensive sampling of active convection in the ITCZ region near Central America was performed from multiple aircraft and satellite sensors. As part of a sampling strategy designed to study cloud processes, the NASA ER-2, WB-57 and DC-8 flew in stacked "racetrack patterns" in convective cells. On July 24, 2007, the ER-2 and DC-8 probed an actively developing storm and the DC-8 was hit by lightning. Case studies of this flight, and of convective outflow on August 5, 2007 reveal a significant anti-correlation between ozone and condensed cloud water content. With little variability in the boundary layer and a vertical gradient, low ozone in the upper troposphere indicates convective transport. Because of the large spatial and temporal variability in surface CO and other pollutants in this region, low ozone is a better convective indicator. Lower tropospheric tracers methyl hydrogen peroxide, total organic bromine and calcium substantiate the ozone results. OMI measurements of mean upper tropospheric ozone near convection show lower ozone in convective outflow. A mass balance estimation of the amount of convective turnover below the tropical tropopause transition layer (TTL) is 50%, with an altitude of maximum convective outflow located between 10 and 11 km, 4 km below the cirrus anvil tops. It appears that convective lofting in this region of the ITCZ is either a two-stage or a rapid mixing process, because undiluted boundary layer air is never sampled in the convective outflow.

  17. Convective Distribution of Tropospheric Ozone and Tracers in the Central American ITCZ Region: Evidence from Observations During TC4

    NASA Technical Reports Server (NTRS)

    Avery, Melody; Twohy, Cynthia; MCabe, David; Joiner, Joanna; Severance, Kurt; Atlas, Eliot; Blake, Donald; Bui, T. P.; Crounse, John; Dibb, Jack; hide

    2010-01-01

    During the Tropical Composition, Clouds and Climate Coupling (TC4) experiment that occurred in July and August of 2007, extensive sampling of active convection in the ITCZ region near Central America was performed from multiple aircraft and satellite sensors. As part of a sampling strategy designed to study cloud processes, the NASA ER-2, WB-57 and DC-8 flew in stacked "racetrack patterns" in convective cells. On July 24, 2007, the ER-2 and DC-8 probed an actively developing storm and the DC-8 was hit by lightning. Case studies of this flight, and of convective outflow on August 5, 2007 reveal a significant anti-correlation between ozone and condensed cloud water content. With little variability in the boundary layer and a vertical gradient, low ozone in the upper troposphere indicates convective transport. Because of the large spatial and temporal variability in surface CO and other pollutants in this region, low ozone is a better convective indicator. Lower tropospheric tracers methyl hydrogen peroxide, total organic bromine and calcium substantiate the ozone results. OMI measurements of mean upper tropospheric ozone near convection show lower ozone in convective outflow. A mass balance estimation of the amount of convective turnover below the tropical tropopause transition layer (TTL) is 50%, with an altitude of maximum convective outflow located between 10 and 11 km, 4 km below the cirrus anvil tops. It appears that convective lofting in this region of the ITCZ is either a two-stage or a rapid mixing process, because undiluted boundary layer air is never sampled in the convective outflow.

  18. The Proceedings of the Annual Meeting of the Central District of the American Alliance for Health, Physical Education, Recreation, and Dance (Omaha, NE, April 29-May 2, 1993). [Abstracts.

    ERIC Educational Resources Information Center

    Richardson, James A., Ed.; Hoadley, Michael, Ed.

    This publication, designed to communicate the history and research activities of the Central District of the American Alliance for Health, Physical Education, Recreation, and Dance, presents summaries of 20 papers. The papers focus on elementary physical education specialists; physical education instruction of classroom teachers; child care…

  19. The Proceedings of the Annual Meeting of the Central District of the American Alliance for Health, Physical Education, Recreation, and Dance (Des Moines, IA, April 29-May 3, 1992). [Abstracts.

    ERIC Educational Resources Information Center

    Richardson, James A., Ed.; Hoadley, Michael, Ed.

    This publication is designed to communicate the history and research activities of members of the Central District of the American Alliance for Health, Physical Education, Recreation, and Dance. It presents summaries of 30 papers and conference presentations on such topics as pioneering physical educators; cholesterol in college football players;…

  20. Increased degassing from the Southern Central American Volcanic Arc in response to crustal stress change following the 2012 Nicoya earthquake?

    NASA Astrophysics Data System (ADS)

    de Moor, M. J.; Kern, C.; Fischer, T. P.; Avard, G.; Aiuppa, A.; Protti, M.; Muller, C.; Alvarez, J.; Saballos, J. A.; Galle, B.

    2016-12-01

    The aim of this work is to provide an updated assessment of SO2 and CO2 fluxes from the Southern Central America Volcanic Arc (SCAVA) for the period 2015-2016. We present over 300 new ground-based remote sensing sulfur dioxide flux measurements (DOAS traverses) conducted at 10 volcanoes in Costa Rica and Nicaragua, representing the most comprehensive assessment of volcanic gas flux at SCAVA to date. The data were filtered to exclude measurements directly associated with eruptive activity. The SO2 flux from this 500km section of arc is thus conservatively estimated at 4622 ± 1586 tons/day (unfiltered average of the data yields 6114 ± 1956 tons/day SO2). Our best estimate is about double that of any previous estimations (data from 1972-2013). We attribute this increase in part to our more complete assessment of the arc, as previous studies considered fluxes from only 5 to 7 of the SCAVA volcanoes. Additionally,a greater number of SCAVA volcanoes have had eruptions in 2015-2016 than in any two-year period since 1980. A possible explanation for increased degassing and volcanic activity is a change in crustal stress regime following the 2012 Nicoya earthquake (Mw = 7.8). GPS data show that the SCAVA has experienced a dramatic change from compression to extension, potentially opening conduits for volatiles and magmas to rise from the mantle and lower crustal regions. The dominant contributors to volcanic degassing at SCAVA are Masaya and Turrialba volcanoes, which show average passive degassing SO2 fluxes of 1984 ± 890 T/d and 1672 ± 925 T/d respectively during 2015-2016. High-quality MultiGAS time series datasets for both of these volcanoes provide robust measurements of CO2/SO2 values associated with SO2 flux measurement at these volcanoes. Based on these data we estimate the CO2 flux from Masaya at 5487 ± 1800 T/d and from Turrialba at 4873 ± 2053 T/d. Combining our arc SO2 flux data with gas composition data for the other volcanoes as well as estimations of

  1. The relationship between the Central Pacific El Niño and forest fire occurrence in the North American West

    NASA Astrophysics Data System (ADS)

    Banholzer, S. P.; Donner, S. D.; McKendry, I.

    2011-12-01

    In recent decades, the frequency of forest fires has been increasing in western North America (NAW). Several studies have already established a connection between climate oscillations, such as ENSO, and forest fire occurrence. However, a recently discovered variant of El Niño, called El Niño Modoki or Central Pacific El Niño (CP-El Niño), has been observed more frequently in the last few decades. This may cause different extra tropical teleconnections than the canonical El Niño (Eastern Pacific El Niño or EP-El Niño). The objective of this research is to find out if the past CP-El Niño events are associated with a different fire pattern across the NAW than during past EP-El Niño events. To investigate the possibly different fire regime, historical climate and forest fire data of the NAW over the last three decades were analyzed. Past CP-El Niño events during 1980-2010 were identified with the Improved El Niño Modoki Index (IEMI) and the HadISST dataset. Nino3 index was used to identify canonical El Niño and La Niña events. Seasonal climate composites of temperature and precipitation were generated for the NAW with the NARR dataset, separately for the past EP-El Niño and CP-El Niño years. Forest fire data were compiled for the same time period for the NAW (from California up to Alaska). Forest fire data sources for western Canada are the Canadian National Fire Database and for the western United States the Monitoring Trends in Burn Severity (MTBS) as well as the National Interagency Fire Center. The seasonal climate composites reveal different climate patterns related to the two types of El Niño. Quantitative analysis of the fire data shows also a different pattern during CP years than during EP years. These differences may be related to the altered teleconnections of the two types of El Niño. The conclusions drawn from this study could be used for forest fire management regarding fire suppression and also for predicting fire severity.

  2. Clinicopathologic features of adult T-cell leukemias/lymphomas at a North American tertiary care medical center: infrequent involvement of the central nervous system.

    PubMed

    Hsi, Andy C; Kreisel, Friederike H; Frater, John L; Nguyen, TuDung T

    2014-02-01

    Human T-cell lymphotropic virus type 1 is associated with adult T-cell leukemia/lymphoma (ATLL). Published series of ATLLs seen at a United States medical institution are rare. We present the features of 4 ATLLs diagnosed at our North American tertiary care medical center from 1990 to 2012. Despite the absence of a history of origin from an endemic region, all our ATLLs demonstrated evidence of human T-cell lymphotropic virus type 1 infection. Central nervous system (CNS) involvement by ATLL was uncommon in our series, and represented only 1.6% (1/64) of all CNS B-cell or T-cell lymphomas diagnosed over a 20+ year period at our institution. Review of the medical literature reveals that the majority of CNS-involved ATLLs present with the lymphoma or acute subtype, and complete remission is difficult to achieve in these cases. CNS involvement frequently occurs with a systemic disease, which carries an aggressive clinical course with poor prognosis. In addition, CNS involvement by ATLL can be the initial presentation or seen with relapsed disease, can be the only site or be associated with other tissue sites of involvement, and may manifest with variable clinical signs/symptoms. Our retrospective study reveals that ATLLs are rare mature T-cell lymphomas in a native North American population, but the clinical and histopathologic features of ATLLs from this nonendemic region are similar to those seen from other endemic regions. Early recognition of these rare ATLLs involving uncommon sites, such as the CNS, will help optimize treatment for these infrequent mature T-cell lymphomas.

  3. Paleoseismology and tectonic geomorphology of the Pallatanga fault (Central Ecuador), a major structure of the South-American crust

    NASA Astrophysics Data System (ADS)

    Baize, Stéphane; Audin, Laurence; Winter, Thierry; Alvarado, Alexandra; Pilatasig Moreno, Luis; Taipe, Mercedes; Reyes, Pedro; Kauffmann, Paul; Yepes, Hugo

    2015-05-01

    The Pallatanga fault (PF) is a prominent NNE-SSW strike-slip fault crossing Central Ecuador. This structure is suspected to have hosted large earthquakes, including the 1797 Riobamba event which caused severe destructions to buildings and a heavy death toll (more than 12,000 people), as well as widespread secondary effects like landsliding, liquefaction and surface cracking. The scope of this study is to evaluate the seismic history of the fault through a paleoseismological approach. This work also aims at improving the seismotectonic map of this part of the Andes through a new mapping campaign and, finally, aims at improving the seismic hazard assessment. We show that the PF continues to the north of the previously mapped fault portion in the Western Cordillera (Rumipamba-Pallatanga portion) into the Inter-Andean Valley (Riobamba basin). Field evidences of faulting are numerous, ranging from a clear geomorphological signature to fault plane outcrops. Along the western side of the Riobamba basin, the strike-slip component seems predominant along several fault portions, with a typical landscape assemblage (dextral offsets of valleys, fluvial terrace risers and generation of linear pressure ridges). In the core of the inter-Andean valley, the main fault portion exhibits a vertical component along the c. 100 m-high cumulative scarp. The presence of such an active fault bounding the western suburbs of Riobamba drastically increases the seismic risk for this densely inhabited and vulnerable city. To the east (Peltetec Massif, Cordillera Real), the continuation of the Pallatanga fault is suspected, but not definitely proved yet. Based on the analysis of three trenches, we state that the Rumipamba-Pallatanga section of the PF experienced 4 (maybe 5) Holocene to Historical strong events (Mw > 7). The coseismic behavior of the fault is deduced from the occurrence of several colluvial wedges and layers associated with the fault activity and interbedded within the organic

  4. Towards a phylogenetic approach to the composition of species complexes in the North and Central American Triatoma, vectors of Chagas disease.

    PubMed

    de la Rúa, Nicholas M; Bustamante, Dulce M; Menes, Marianela; Stevens, Lori; Monroy, Carlota; Kilpatrick, C William; Rizzo, Donna; Klotz, Stephen A; Schmidt, Justin; Axen, Heather J; Dorn, Patricia L

    2014-06-01

    Phylogenetic relationships of insect vectors of parasitic diseases are important for understanding the evolution of epidemiologically relevant traits, and may be useful in vector control. The sub-family Triatominae (Hemiptera:Reduviidae) includes ∼140 extant species arranged in five tribes comprised of 15 genera. The genus Triatoma is the most species-rich and contains important vectors of Trypanosoma cruzi, the causative agent of Chagas disease. Triatoma species were grouped into complexes originally by morphology and more recently with the addition of information from molecular phylogenetics (the four-complex hypothesis); however, without a strict adherence to monophyly. To date, the validity of proposed species complexes has not been tested by statistical tests of topology. The goal of this study was to clarify the systematics of 19 Triatoma species from North and Central America. We inferred their evolutionary relatedness using two independent data sets: the complete nuclear internal transcribed spacer-2 ribosomal DNA (ITS-2 rDNA) and head morphometrics. In addition, we used the Shimodaira-Hasegawa statistical test of topology to assess the fit of the data to a set of competing systematic hypotheses (topologies). An unconstrained topology inferred from the ITS-2 data was compared to topologies constrained based on the four-complex hypothesis or one inferred from our morphometry results. The unconstrained topology represents a statistically significant better fit of the molecular data than either the four-complex or the morphometric topology. We propose an update to the composition of species complexes in the North and Central American Triatoma, based on a phylogeny inferred from ITS-2 as a first step towards updating the phylogeny of the complexes based on monophyly and statistical tests of topologies. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Towards a Phylogenetic Approach to the Composition of Species Complexes in the North and Central American Triatoma, Vectors of Chagas Disease

    PubMed Central

    de la Rúa, Nicholas M.; Bustamante, Dulce M.; Menes, Marianela; Stevens, Lori; Monroy, Carlota; Kilpatrick, William; Rizzo, Donna; Klotz, Stephen A.; Schmidt, Justin; Axen, Heather J.; Dorn, Patricia L.

    2014-01-01

    Phylogenetic relationships of insect vectors of parasitic diseases are important for understanding the evolution of epidemiologically relevant traits, and may be useful in vector control. The subfamily Triatominae (Hemiptera:Reduviidae) includes ~140 extant species arranged in five tribes comprised of 15 genera. The genus Triatoma is the most species-rich and contains important vectors of Trypanosoma cruzi, the causative agent of Chagas disease. Triatoma species were grouped into complexes originally by morphology and more recently with the addition of information from molecular phylogenetics (the four-complex hypothesis); however, without a strict adherence to monophyly. To date, the validity of proposed species complexes has not been tested by statistical tests of topology. The goal of this study was to clarify the systematics of 19 Triatoma species from North and Central America. We inferred their evolutionary relatedness using two independent data sets: the complete nuclear Internal Transcribed Spacer-2 ribosomal DNA (ITS-2 rDNA) and head morphometrics. In addition, we used the Shimodaira-Hasegawa statistical test of topology to assess the fit of the data to a set of competing systematic hypotheses (topologies). An unconstrained topology inferred from the ITS-2 data was compared to topologies constrained based on the four-complex hypothesis or one inferred from our morphometry results. The unconstrained topology represents a statistically significant better fit of the molecular data than either the four-complex or the morphometric topology. We propose an update to the composition of species complexes in the North and Central American Triatoma, based on a phylogeny inferred from ITS-2 as a first step towards updating the phylogeny of the complexes based on monophyly and statistical tests of topologies. PMID:24681261

  6. Cryptic Population Structuring and the Role of the Isthmus of Tehuantepec as a Gene Flow Barrier in the Critically Endangered Central American River Turtle

    PubMed Central

    González-Porter, Gracia P.; Maldonado, Jesús E.; Flores-Villela, Oscar; Vogt, Richard C.; Janke, Axel; Fleischer, Robert C.; Hailer, Frank

    2013-01-01

    The critically endangered Central American River Turtle (Dermatemys mawii) is the only remaining member of the Dermatemydidae family, yet little is known about its population structuring. In a previous study of mitochondrial (mt) DNA in the species, three main lineages were described. One lineage (Central) was dominant across most of the range, while two other lineages were restricted to Papaloapan (PAP; isolated by the Isthmus of Tehuantepec and the Sierra de Santa Marta) or the south-eastern part of the range (1D). Here we provide data from seven polymorphic microsatellite loci and the R35 intron to re-evaluate these findings using DNA from the nuclear genome. Based on a slightly expanded data set of a total of 253 samples from the same localities, we find that mtDNA and nuclear DNA markers yield a highly congruent picture of the evolutionary history and population structuring of D. mawii. While resolution provided by the R35 intron (sequenced for a subset of the samples) was very limited, the microsatellite data revealed pronounced population structuring. Within the Grijalva-Usumacinta drainage basin, however, many populations separated by more than 300 kilometers showed signals of high gene flow. Across the entire range, neither mitochondrial nor nuclear DNA show a significant isolation-by-distance pattern, but both genomes highlight that the D. mawii population in the Papaloapan basin is genetically distinctive. Further, both marker systems detect unique genomic signals in four individuals with mtDNA clade 1D sampled on the southeast edge of the Grijalva-Usumacinta basin. These individuals may represent a separate cryptic taxon that is likely impacted by recent admixture. PMID:24086253

  7. Electroacupuncture Improves Insulin Resistance by Reducing Neuroprotein Y/Agouti-Related Protein Levels and Inhibiting Expression of Protein Tyrosine Phosphatase 1B in Diet-induced Obese Rats.

    PubMed

    Liu, Xia; He, Jun-Feng; Qu, Ya-Ting; Liu, Zhi-Jun; Pu, Qing-Yang; Guo, Sheng-Tong; Du, Jia; Jiang, Peng-Fei

    2016-04-01

    Electroacupuncture (EA) has been shown to exert beneficial effects on obesity, but the mechanism is unclear. This study investigated the effects of EA on diet-induced obese (DIO) rats. Fifty male Sprague-Dawley rats were randomly divided into low-fat diet (LFD, 10 rats) and high-fat diet (HFD, 40 rats) groups. After the DIO models had been established, successful model rats were randomly divided into HFD, EA, and orlistat (OLST) groups. The EA group received EA at Zusanli (ST36) and Quchi (LI11) for 20 minutes once per day for 28 days. The OLST group was treated with orlistat by gavage. The body weight, homeostasis model assessment-insulin resistance index, adipocyte diameters, and neuroprotein Y/agouti-related protein and protein tyrosine phosphatase 1B levels were significantly lower in the EA group than in the HFD group. The rats of the OLST group showed watery stools and yellow hairs whereas those of the EA group had regular stools and sleek coats. The effect of EA on weight loss may be related to improved insulin resistance caused by changes in the adipocyte size and by reductions in the expressions of neuroprotein Y/agouti-related protein and protein tyrosine phosphatase 1B. This study indicates that EA may be a better method of alternative therapy for treating obesity and other metabolic diseases.

  8. Agouti Revisited: Transcript Quantification of the ASIP Gene in Bovine Tissues Related to Protein Expression and Localization

    PubMed Central

    Albrecht, Elke; Komolka, Katrin; Kuzinski, Judith; Maak, Steffen

    2012-01-01

    Beside its role in melanogenesis, the agouti signaling protein (ASIP) has been related to obesity. The potentially crucial role in adipocyte development makes it a tempting candidate for economic relevant, fat related traits in farm animals. The objective of our study was to characterize the mRNA expression of different ASIP transcripts and of putative targets in different bovine tissues, as well as to study consequences on protein abundance and localization. ASIP mRNA abundance was determined by RT-qPCR in adipose and further tissues of cattle representing different breeds and crosses. ASIP mRNA was up-regulated more than 9-fold in intramuscular fat of Japanese Black cattle compared to Holstein (p<0.001). Further analyses revealed that a transposon-derived transcript was solely responsible for the increased ASIP mRNA abundance. This transcript was observed in single individuals of different breeds indicating a wide spread occurrence of this insertion at the ASIP locus in cattle. The protein was detected in different adipose tissues, skin, lung and liver, but not in skeletal muscle by Western blot with a bovine-specific ASIP antibody. However, the protein abundance was not related to the observed ASIP mRNA over-expression. Immuno-histochemical analyses revealed a putative nuclear localization of ASIP additionally to the expected cytosolic signal in different cell types. The expression of melanocortin receptors (MCR) 1 to 5 as potential targets for ASIP was analyzed by RT-PCR in subcutaneous fat. Only MC1R and MC4R were detected indicating a similar receptor expression like in human adipose tissue. Our results provide evidence for a widespread expression of ASIP in bovine tissues at mRNA and, for the first time, at protein level. ASIP protein is detectable in adipocytes as well as in further cells of adipose tissue. We generated a basis for a more detailed investigation of ASIP function in peripheral tissues of various mammalian species. PMID:22530003

  9. Comparing the impacts of Miocene-Pliocene changes in inter-ocean gateways on climate: Central American Seaway, Bering Strait, and Indonesia

    NASA Astrophysics Data System (ADS)

    Brierley, Chris M.; Fedorov, Alexey V.

    2016-06-01

    Changes in inter-ocean gateways caused by tectonic processes have been long considered an important factor in climate evolution on geological timescales. Three major gateway changes that occurred during the Late Miocene and Pliocene epochs are the closing of the Central American Seaway (CAS) by the uplift of the Isthmus of Panama, the opening of the Bering Strait, and the closing of a deep channel between New Guinea and the Equator. This study compares the global climatic effects of these changes within the same climate model framework. We find that the closure of the CAS and the opening of the Bering Strait induce the strongest effects on the Atlantic meridional overturning circulation (AMOC). However, these effects potentially compensate, as the closure of the CAS and the opening of the Bering Strait cause similar AMOC changes of around 2 Sv (strengthening and weakening respectively). Previous simulations with an open CAS consistently simulated colder oceanic conditions in the Northern Hemisphere - contrasting with the evidence for warmer sea surface temperatures 10-3 million years ago. Here we argue that this cooling is overestimated because (a) the models typically simulated too strong an AMOC change not yet in equilibrium, (b) used a channel too deep and (c) lacked the compensating effect of the closed Bering Strait - a factor frequently ignored despite its potential influence on northern high latitudes and ice-sheet growth. Further, we discuss how these gateway changes affect various climatic variables from surface temperature and precipitation to ENSO characteristics.

  10. Causes of dust size variability in central East Antarctica (Dome B): Atmospheric transport from expanded South American sources during Marine Isotope Stage 2

    NASA Astrophysics Data System (ADS)

    Delmonte, Barbara; Paleari, Chiara Ileana; Andò, Sergio; Garzanti, Eduardo; Andersson, Per Sune; Petit, Jean Robert; Crosta, Xavier; Narcisi, Biancamaria; Baroni, Carlo; Salvatore, Maria Cristina; Baccolo, Giovanni; Maggi, Valter

    2017-07-01

    We here investigate the spatial and temporal variability of eolian dust particle sorting recorded in the Dome B (77° 05‧ S, 94° 55' E) ice core, central East Antarctica, during Marine Isotope Stage (MIS) 2. We address the question whether such changes reflect variable transport pathways from a unique source area or rather a variable apportionment from diverse Southern Hemisphere sources transported at different elevation in the troposphere. The Sr-Nd radiogenic isotope composition of glacial dust samples as well as single-particle Raman mineralogy support the hypothesis of a single dust provenance both for coarse and fine mode dust events at Dome B. The southern South American provenance of glacial dust in Antarctica deduced from these results indicate a dust composition coherent with a mixture of volcanic material and minerals derived from metamorphic and plutonic rocks. Additionally, Dome B glacial samples contain aragonite particles along with diatom valves of marine benthic/epiphytic species and freshwater species living today in the northern Antarctic Peninsula and southern South America. These data suggest contribution from the exposed Patagonian continental shelf and glacial outwash plains of southern Patagonia at the time when sea level reached its minimum. Our results confirm that dust sorting is controlled by the relative intensity of the two main patterns of tropospheric dust transport onto the inner Plateau, i.e. fast low-level advection and long-range high-altitude transport including air subsidence over Antarctica.

  11. Exploration of immunoglobulin transcriptomes from mice immunized with three-finger toxins and phospholipases A2 from the Central American coral snake, Micrurus nigrocinctus

    PubMed Central

    Engmark, Mikael; Clouser, Christopher; Timberlake, Sonia; Vigneault, Francois; Gutiérrez, José María; Lomonte, Bruno

    2017-01-01

    Snakebite envenomings represent a neglected public health issue in many parts of the rural tropical world. Animal-derived antivenoms have existed for more than a hundred years and are effective in neutralizing snake venom toxins when timely administered. However, the low immunogenicity of many small but potent snake venom toxins represents a challenge for obtaining a balanced immune response against the medically relevant components of the venom. Here, we employ high-throughput sequencing of the immunoglobulin (Ig) transcriptome of mice immunized with a three-finger toxin and a phospholipase A2 from the venom of the Central American coral snake, Micrurus nigrocinctus. Although exploratory in nature, our indicate results showed that only low frequencies of mRNA encoding IgG isotypes, the most relevant isotype for therapeutic purposes, were present in splenocytes of five mice immunized with 6 doses of the two types of toxins over 90 days. Furthermore, analysis of Ig heavy chain transcripts showed that no particular combination of variable (V) and joining (J) gene segments had been selected in the immunization process, as would be expected after a strong humoral immune response to a single antigen. Combined with the titration of toxin-specific antibodies in the sera of immunized mice, these data support the low immunogenicity of three-finger toxins and phospholipases A2found in M. nigrocinctusvenoms, and highlight the need for future studies analyzing the complexity of antibody responses to toxins at the molecular level. PMID:28149694

  12. Comparison of six commercial DNA extraction kits for detection of Brucella neotomae in Mexican and Central American-style cheese and other milk products.

    PubMed

    Lusk, Tina S; Strain, Errol; Kase, Julie A

    2013-05-01

    Raw or inadequately pasteurized milk from infected animals and cheese made with such milk are a frequent vehicle for human brucellosis infection. Also, biological terrorism is a concern with certain Brucella spp. Due to matrix-associated real-time polymerase chain reaction (qPCR) inhibitors, robust sample preparations are crucial. We compared six commercial nucleic acid extraction kits using nine Mexican and Central American-style soft cheeses or creams and three liquid milk products inoculated with Brucella neotomae, a surrogate for pathogenic Brucella spp. Kits were evaluated by purity and quantity of DNA as determined by qPCR Ct values, reproducibility across cheese and milk types, and cost. At 10(7) CFU/g in four different cheeses, Qiagen statistically outperformed all other kits. When two cheese styles were inoculated at dual levels, Qiagen and High Pure kit extracted samples at 1.5 × 10(5) CFU/g produced average Ct values of 34-39, while PrepSEQ and MagMAX kit extracted samples exhibited higher or no Ct values. High Pure and Qiagen kits excelled also with liquid milk products. Considering matrices, inoculation levels, and kits evaluated, High Pure and Qiagen products produced Brucella DNA of high quality and quantity indicated by the lowest Ct values and were the least expensive.

  13. Exploration of immunoglobulin transcriptomes from mice immunized with three-finger toxins and phospholipases A2 from the Central American coral snake, Micrurus nigrocinctus.

    PubMed

    Laustsen, Andreas H; Engmark, Mikael; Clouser, Christopher; Timberlake, Sonia; Vigneault, Francois; Gutiérrez, José María; Lomonte, Bruno

    2017-01-01

    Snakebite envenomings represent a neglected public health issue in many parts of the rural tropical world. Animal-derived antivenoms have existed for more than a hundred years and are effective in neutralizing snake venom toxins when timely administered. However, the low immunogenicity of many small but potent snake venom toxins represents a challenge for obtaining a balanced immune response against the medically relevant components of the venom. Here, we employ high-throughput sequencing of the immunoglobulin (Ig) transcriptome of mice immunized with a three-finger toxin and a phospholipase A2 from the venom of the Central American coral snake, Micrurus nigrocinctus. Although exploratory in nature, our indicate results showed that only low frequencies of mRNA encoding IgG isotypes, the most relevant isotype for therapeutic purposes, were present in splenocytes of five mice immunized with 6 doses of the two types of toxins over 90 days. Furthermore, analysis of Ig heavy chain transcripts showed that no particular combination of variable (V) and joining (J) gene segments had been selected in the immunization process, as would be expected after a strong humoral immune response to a single antigen. Combined with the titration of toxin-specific antibodies in the sera of immunized mice, these data support the low immunogenicity of three-finger toxins and phospholipases A2 found in M. nigrocinctusvenoms, and highlight the need for future studies analyzing the complexity of antibody responses to toxins at the molecular level.

  14. The Influence of a Precursor Central American Gyre and a Northerly Surge into the Gulf of Tehuantepec on the Formation of Hurricane Patricia in October 2015

    NASA Astrophysics Data System (ADS)

    Bosart, L. F.; Bentley, A. M.; Levine, A. S.; Papin, P. P.

    2016-12-01

    The National Hurricane Center (NHC) initiated advisories on Tropical Depression (TD) Patricia at 1500 UTC 20 October 2015. Patricia originated from a pre-existing area of disturbed weather over the eastern Gulf of Tehuantepec (GoT) subsequent to the formation of a Central American gyre (CAG) and a surge of northerly gap flow across the Isthmus of Tehuantepec (Chivela Pass) and into the GoT. The gap flow was driven by strong low-level height rises over the northern Gulf of Mexico behind a southeastward-moving cold front. Low-level anticyclogenesis over the Gulf of Mexico and the southeastern United States behind the cold front and CAG-related surface pressure falls over Central America contributed to the development of an anomalously strong meridional surface pressure gradient that further sustained the aforementioned gap flow. An elongated strip of cyclonic shear vorticity formed along the eastern margin of the northerly gap flow over the GoT while oceanic heat and moisture fluxes maximized in the core of the strongest flow. Subsequently, this vorticity strip broke down into a cyclonic vortex shortly by 0000 UTC 20 October which prompted the National Hurricane Center to declare that tropical depression (TD) had formed near 13.4°N and 94.0°W by 0600 UTC 20 October. This TD was named tropical storm (TS) Patricia at 0000 UTC 21 October as the developing TS moved over a region of anomalously warm SSTs and high oceanic heat content in the presence of large oceanic heat and moisture fluxes. Northerly gap flow ceased and the CAG circulation broke down as a strengthening TS Patricia in the eastern Pacific crossed the longitude (95°W) of the Chivela Pass, leading to the cessation of northerly gap flow and the onset of strengthening southerly flow. Deep tropical moisture concentrated to the north and east of the now remnant CAG circulation center was advected northwestward into the western Gulf of Mexico where it supported very heavy rainfall in southeastern Texas. This

  15. Influence of drift and admixture on population structure of American black bears (Ursus americanus) in the Central Interior Highlands, USA, 50 years after translocation

    USGS Publications Warehouse

    Puckett, Emily E.; Kristensen, Thea V.; Wilton, Clay M.; Lyda, Sara B.; Noyce, Karen V.; Holahan, Paula M.; Leslie,, David M.; Beringer, J.; Belant, Jerrold L.; White, D.; Eggert, L.S.

    2014-01-01

    Bottlenecks, founder events, and genetic drift often result in decreased genetic diversity and increased population differentiation. These events may follow abundance declines due to natural or anthropogenic perturbations, where translocations may be an effective conservation strategy to increase population size. American black bears (Ursus americanus) were nearly extirpated from the Central Interior Highlands, USA by 1920. In an effort to restore bears, 254 individuals were translocated from Minnesota, USA, and Manitoba, Canada, into the Ouachita and Ozark Mountains from 1958 to 1968. Using 15 microsatellites and mitochondrial haplotypes, we observed contemporary genetic diversity and differentiation between the source and supplemented populations. We inferred four genetic clusters: Source, Ouachitas, Ozarks, and a cluster in Missouri where no individuals were translocated. Coalescent models using approximate Bayesian computation identified an admixture model as having the highest posterior probability (0.942) over models where the translocation was unsuccessful or acted as a founder event. Nuclear genetic diversity was highest in the source (AR = 9.11) and significantly lower in the translocated populations (AR = 7.07-7.34; P = 0.004). The Missouri cluster had the lowest genetic diversity (AR = 5.48) and served as a natural experiment showing the utility of translocations to increase genetic diversity following demographic bottlenecks. Differentiation was greater between the two admixed populations than either compared to the source, suggesting that genetic drift acted strongly over the eight generations since the translocation. The Ouachitas and Missouri were previously hypothesized to be remnant lineages. We observed a pretranslocation remnant signature in Missouri but not in the Ouachitas.

  16. Influence of drift and admixture on population structure of American black bears (Ursus americanus) in the Central Interior Highlands, USA, 50 years after translocation.

    PubMed

    Puckett, Emily E; Kristensen, Thea V; Wilton, Clay M; Lyda, Sara B; Noyce, Karen V; Holahan, Paula M; Leslie, David M; Beringer, Jeff; Belant, Jerrold L; White, Don; Eggert, Lori S

    2014-05-01

    Bottlenecks, founder events, and genetic drift often result in decreased genetic diversity and increased population differentiation. These events may follow abundance declines due to natural or anthropogenic perturbations, where translocations may be an effective conservation strategy to increase population size. American black bears (Ursus americanus) were nearly extirpated from the Central Interior Highlands, USA by 1920. In an effort to restore bears, 254 individuals were translocated from Minnesota, USA, and Manitoba, Canada, into the Ouachita and Ozark Mountains from 1958 to 1968. Using 15 microsatellites and mitochondrial haplotypes, we observed contemporary genetic diversity and differentiation between the source and supplemented populations. We inferred four genetic clusters: Source, Ouachitas, Ozarks, and a cluster in Missouri where no individuals were translocated. Coalescent models using approximate Bayesian computation identified an admixture model as having the highest posterior probability (0.942) over models where the translocation was unsuccessful or acted as a founder event. Nuclear genetic diversity was highest in the source (AR = 9.11) and significantly lower in the translocated populations (AR = 7.07-7.34; P = 0.004). The Missouri cluster had the lowest genetic diversity (AR = 5.48) and served as a natural experiment showing the utility of translocations to increase genetic diversity following demographic bottlenecks. Differentiation was greater between the two admixed populations than either compared to the source, suggesting that genetic drift acted strongly over the eight generations since the translocation. The Ouachitas and Missouri were previously hypothesized to be remnant lineages. We observed a pretranslocation remnant signature in Missouri but not in the Ouachitas. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  17. Manufacturing combustible briquettes from forestry and timber industries` wastes in order to reduce the overexploitation of fuelwood in Central American forests

    SciTech Connect

    Ortiz, L.; Gonzalez, E.

    1993-12-31

    A serious degradation of Central American forest is currently taking place because of uncontrolled fuelwood overexploitation. As an example, in Guatemala over 40% of forest destruction is caused by this reason. In the meanwhile, waste biomass from the sawmills representing 30 to 50% of total wood volume processed, due to low technological level of the facilities, and having an energetic potential equivalent to their thermal and electric needs is destroyed through uncontrolled burning, thus causing important environmental and landscape impact, since the byproducts are incinerated outdoors on the spot the constant smoke together with the noise level produced by the diesel power generators makes working conditions painful for the large labor force usually operating these sawmills because of low wages in these countries. To help solve this increasing problem, it would be possible to use the waste biomass for the production of electric power, through cogeneration, for sawmill selfuse or selling to the public electric lines, or even manufacturing of fuel briquettes which would have a potential market in countries such as Republica Dominicana, Honduras Guatemala, etc. as a substitute for charcoal and fuelwood, thus permitting a considerable reduction of the environmental degradation and predation suffered by forest areas in these countries. For these reasons, we consider it of interest to study briquetting techniques and their intrinsic problems in depth. For such purpose, we have carried out a series of real scale briquetting experiences with different types of lignocelulosic wastes and mixtures of them under different conditions, aiming to optimize procedure methodology and reduce production expenses, thus making offer increase easier. Manufacturing procedure and analytics developed to carry out the experiences are described in the present document. Main results obtained are summarized, and mathematical, energetic, analytical and economic aspects are discussed as well.

  18. Spanish colonial effects on Native American mating structure and genetic variability in northern and central Florida: Evidence from Apalachee and western Timucua.

    PubMed

    Stojanowski, Christopher M

    2005-10-01

    Standard population genetic analyses are implemented for a series of precontact and contact period samples from central and northern Florida to investigate changes in genetic variability and population affinity coincident with the establishment of Spanish missions during the 17th century. Estimates of F(ST) based on odontometric data indicate limited heterogeneity for the Apalachee samples, suggestive of some degree of within-group endogamy for this ethnic group prior to contact. This corresponds well with ethnohistoric reconstructions indicating that Apalachee were populous, partially linguistically isolated from its neighbors, and involved in persistent cycles of warfare with neighboring groups. Estimates of extralocal gene flow for the Apalachee samples indicate limited initial changes in the mating structure of these populations. After 1650, however, extralocal gene flow increases, consistent with evidence for dramatic population movements throughout northern Florida and increased Spanish presence in the province, particularly at the mission of San Luis. Inclusion of non-Apalachee outgroups does not increase estimates of genetic heterogeneity, as was expected based on ethnohistoric data. The pattern of genetic distances suggests a biological division between north and south Florida population groups, consistent with archaeological and ethnohistoric data, and similarly indicates some distinction between precontact and postcontact local groups. Differential extralocal gene flow experienced by pre-1650 Apalachee and Timucua populations suggests localized mission experience. The Apalachee, with large, dense populations, experienced limited initial changes in genetic diversity or mating structure. However, after 1650 they were apparently involved in a much more expansive mating network that may have included Spaniards and immigrant Native American groups to the region. These results are in contrast to the mission experience of the Guale Indians of the Georgia coast.

  19. New Insights into Strain Accumulation and Release in the Central and Northern Walker Lane, Pacific-North American Plate Boundary, California and Nevada, USA

    NASA Astrophysics Data System (ADS)

    Bormann, Jayne M.

    The Walker Lane is a 100 km-wide distributed zone of complex transtensional faulting that flanks the eastern margin of the Sierra Nevada. Up to 25% of the total Pacific-North American relative right-lateral plate boundary deformation is accommodated east of the Sierra Nevada, primarily in the Walker Lane. The results of three studies in the Central and Northern Walker Lane offer new insights into how constantly accumulating plate boundary shear strain is released on faults in the Walker Lane and regional earthquake hazards. This research is based on the collection and analysis of new of geologic and geodetic datasets. Two studies are located in the Central Walker Lane, where plate boundary deformation is accommodated on northwest trending right-lateral faults, east-northeast trending left-lateral faults, and north trending normal faults. In this region, a prominent set of left-stepping, en-echelon, normal fault-bounded basins between Walker Lake and Lake Tahoe fill a gap in Walker Lane strike slip faults. Determining how these basins accommodate shear strain is a primary goal of this research. Paleoseismic and neotectonic observations from the Wassuk Range fault zone in the Walker Lake basin record evidence for at least 3 Holocene surface rupturing earthquakes and Holocene/late Pleistocene vertical slip rates between 0.4-0.7 mm/yr on the normal fault, but record no evidence of right-lateral slip along the rangefront fault. A complementary study presents new GPS velocity data that measures present-day deformation across the Central Walker Lane and infers fault slip and block rotation rates using an elastic block model. The model results show a clear partitioning between distinct zones of strain accommodation characterized by (1) right-lateral translation of blocks on northwest trending faults, (2) left-lateral slip and clockwise block rotations between east and northeast trending faults, and (3) right-lateral oblique normal slip with minor clockwise block rotations

  20. The quantification of testicular cells during the postnatal development in two Caviomorph rodents: the guinea pig (Cavia porcellus) and the cutia (Dasyprocta agouti).

    PubMed

    Simões, Luciana S; Sasahara, Tais H C; Favaron, Phelipe O; Marques, Ricardo; Oliveira, Moacir F DE; Machado, Márcia R F; Miglino, Maria Angelica

    2017-01-01

    The germinative, Sertoli and Leydig cells of two caviomorph rodents (Cavia porcellus and Dasyprocta agouti) were counted as well as the estimation of the total volume of the testis and the total volume of seminiferous tubules and interstitium in prepubertal, pubertal and adult animals. The number of spermatogonia, spermatocytes and spermatids cells increased during the pubertal phase in both rodents, notably the spermatid cells. The spermatocyte and spermatid slightly decreased in the adult of both rodents, but the increment in spermatogonia cells number was seen, mainly in cutias. The number of Sertoli cells increased in pubertal rodents, but in the adult the number reduced. Substantial number of Leydig cells was counted in pubertal and adult guinea pigs. In cutias, the number of Leydig cells increased in pubertal phase and decline in adults. The design-based stereological method has proven to be unbiased and reliable to be applied in reproduction studies.

  1. Agouti signalling protein is an inverse agonist to the wildtype and agonist to the melanic variant of the melanocortin-1 receptor in the grey squirrel (Sciurus carolinensis).

    PubMed

    McRobie, Helen R; King, Linda M; Fanutti, Cristina; Symmons, Martyn F; Coussons, Peter J

    2014-06-27

    The melanocortin-1 receptor (MC1R) is a key regulator of mammalian pigmentation. Melanism in the grey squirrel is associated with an eight amino acid deletion in the mutant melanocortin-1 receptor with 24 base pair deletion (MC1RΔ24) variant. We demonstrate that the MC1RΔ24 exhibits a higher basal activity than the wildtype MC1R (MC1R-wt). We demonstrate that agouti signalling protein (ASIP) is an inverse agonist to the MC1R-wt but is an agonist to the MC1RΔ24. We conclude that the deletion in the MC1RΔ24 leads to a receptor with a high basal activity which is further activated by ASIP. This is the first report of ASIP acting as an agonist to MC1R. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  2. Ethanol-Induced Increase of Agouti-Related Protein (AgRP) Immunoreactivity in the Arcuate Nucleus of the Hypothalamus of C57BL/6J, but not 129/SvJ, Inbred Mice

    PubMed Central

    Cubero, Inmaculada; Navarro, Montserrat; Carvajal, Francisca; Lerma-Cabrera, Jose Manuel; Thiele, Todd E.

    2011-01-01

    Background The melanocortin (MC) system is composed of peptides that are cleaved from the polypeptide precursor, pro-opiomelanocortin (POMC). Previous research has shown that MC receptor (MCR) agonists reduce, and MCR antagonists increase, ethanol consumption in rats and mice. Consistently, genetic deletion of the endogenous MCR antagonist, agouti-related protein (AgRP), causes reductions of ethanol-reinforced lever pressing and binge-like ethanol drinking in C57BL/6J mice. Ethanol also has direct effects on the central MC system, as chronic exposure to an ethanol-containing diet causes significant reductions of α-melanocyte stimulating hormone (α-MSH) immunoreactivity in specific brain regions of Sprague-Dawley rats. Together, these observations suggest that the central MC system modulates neurobiological responses to ethanol. To further characterize the role of the MC system in responses to ethanol, here we compared AgRP and α-MSH immunoreactivity in response to an acute injection of saline or ethanol between high ethanol drinking C57BL/6J mice and moderate ethanol drinking 129/SvJ mice. Methods Mice received an intraperitoneal (i.p.) injection of ethanol (1.5 g/kg or 3.5 g/kg; mixed in 0.9% saline) or an equivolume of 0.9% saline. Two hours after injection, animals were sacrificed and their brains were processed for AgRP and α-MSH immunoreactivity. Results Results indicated that acute ethanol administration triggered a dose-dependent increase in AgRP immunoreactivity in the arcuate (ARC) of C57BL/6J mice, an effect that was not evident in the 129/SvJ strain. Although acute administration of ethanol did not influence α-MSH immunoreactivity, C57BL/6J mice had significantly greater overall α-MSH immunoreactivity in the ARC, dorsomedial, and lateral regions of the hypothalamus relative to the 129/SvJ strain. In contrast, C57BL/6J mice displayed significantly lower α-MSH immunoreactivity in the medial amygdala. Conclusions The results show that acute ethanol

  3. Integrated “omics” profiling indicates that miRNAs are modulators of the ontogenetic venom composition shift in the Central American rattlesnake, Crotalus simus simus

    PubMed Central

    2013-01-01

    Background Understanding the processes that drive the evolution of snake venom is a topic of great research interest in molecular and evolutionary toxinology. Recent studies suggest that ontogenetic changes in venom composition are genetically controlled rather than environmentally induced. However, the molecular mechanisms underlying these changes remain elusive. Here we have explored the basis and level of regulation of the ontogenetic shift in the venom composition of the Central American rattlesnake, Crotalus s. simus using a combined proteomics and transcriptomics approach. Results Proteomic analysis showed that the ontogenetic shift in the venom composition of C. s. simus is essentially characterized by a gradual reduction in the expression of serine proteinases and PLA2 molecules, particularly crotoxin, a β-neurotoxic heterodimeric PLA2, concominantly with an increment of PI and PIII metalloproteinases at age 9–18 months. Comparison of the transcriptional activity of the venom glands of neonate and adult C. s. simus specimens indicated that their transcriptomes exhibit indistinguisable toxin family profiles, suggesting that the elusive mechanism by which shared transcriptomes generate divergent venom phenotypes may operate post-transcriptionally. Specifically, miRNAs with frequency count of 1000 or greater exhibited an uneven distribution between the newborn and adult datasets. Of note, 590 copies of a miRNA targeting crotoxin B-subunit was exclusively found in the transcriptome of the adult snake, whereas 1185 copies of a miRNA complementary to a PIII-SVMP mRNA was uniquely present in the newborn dataset. These results support the view that age-dependent changes in the concentration of miRNA modulating the transition from a crotoxin-rich to a SVMP-rich venom from birth through adulhood can potentially explain what is observed in the proteomic analysis of the ontogenetic changes in the venom composition of C. s. simus. Conclusions Existing snake venom

  4. Integrated "omics" profiling indicates that miRNAs are modulators of the ontogenetic venom composition shift in the Central American rattlesnake, Crotalus simus simus.

    PubMed

    Durban, Jordi; Pérez, Alicia; Sanz, Libia; Gómez, Aarón; Bonilla, Fabián; Rodríguez, Santos; Chacón, Danilo; Sasa, Mahmood; Angulo, Yamileth; Gutiérrez, José M; Calvete, Juan J

    2013-04-10

    Understanding the processes that drive the evolution of snake venom is a topic of great research interest in molecular and evolutionary toxinology. Recent studies suggest that ontogenetic changes in venom composition are genetically controlled rather than environmentally induced. However, the molecular mechanisms underlying these changes remain elusive. Here we have explored the basis and level of regulation of the ontogenetic shift in the venom composition of the Central American rattlesnake, Crotalus s. simus using a combined proteomics and transcriptomics approach. Proteomic analysis showed that the ontogenetic shift in the venom composition of C. s. simus is essentially characterized by a gradual reduction in the expression of serine proteinases and PLA2 molecules, particularly crotoxin, a β-neurotoxic heterodimeric PLA2, concominantly with an increment of PI and PIII metalloproteinases at age 9-18 months. Comparison of the transcriptional activity of the venom glands of neonate and adult C. s. simus specimens indicated that their transcriptomes exhibit indistinguisable toxin family profiles, suggesting that the elusive mechanism by which shared transcriptomes generate divergent venom phenotypes may operate post-transcriptionally. Specifically, miRNAs with frequency count of 1000 or greater exhibited an uneven distribution between the newborn and adult datasets. Of note, 590 copies of a miRNA targeting crotoxin B-subunit was exclusively found in the transcriptome of the adult snake, whereas 1185 copies of a miRNA complementary to a PIII-SVMP mRNA was uniquely present in the newborn dataset. These results support the view that age-dependent changes in the concentration of miRNA modulating the transition from a crotoxin-rich to a SVMP-rich venom from birth through adulthood can potentially explain what is observed in the proteomic analysis of the ontogenetic changes in the venom composition of C. s. simus. Existing snake venom toxins are the result of early

  5. Mapping South American Summer Monsoon Changes during Heinrich Event 1 and the LGM: Insights from New Paleolake Records from the Central Andes

    NASA Astrophysics Data System (ADS)

    Chen, C. Y.; McGee, D.; Quade, J.

    2015-12-01

    Cave stalagmite records show strong evidence of abrupt changes in summer monsoons during Heinrich events, but we lack rigorous constraints on the amount of wetting or drying occurring in monsoon regions. Studies on shoreline deposits of closed-basin lakes can establish quantitative bounds on water balance changes through mapping-based estimates of lake volume variations. We present new dating constraints on lake level variations in Agua Caliente I and Laguna Loyoques, two closed-basin, high-altitude paleolakes on the Altiplano-Puna plateau of the Central Andes (23.1°S, 67.4°W, 4250 masl). Because this area receives >70% of its total annual precipitation during austral summer, the region is ideally suited to capture a pure response to changes in the South American summer monsoon (SASM). The plateau is home to several small (<40 km2) lakes surrounded by well-preserved paleoshorelines that indicate past wetter conditions. Agua Caliente I is unique, having multiple shorelines encrusted with biologically-mediated calcium carbonate "tufa" deposits. Initial U-Th dating of these massive shoreline tufas reveals that these deposits are dateable to within ±50 to 300 years due to high U concentrations and low initial Th content (as indicated by high 230Th/232Th). Our U-Th dates show that Agua Caliente I was greater in lake surface area during two periods: 17.5-14.5 kyrs BP, coincident with Heinrich Event 1 (HE1), and 24-23 kyrs BP, roughly coincident with the Last Glacial Maximum (LGM). At these times, Agua Caliente I also overflowed into a neighboring lake basin (Loyoques) through an 8-km long southeast-trending stream channel. Thus, during HE1 and the LGM, the lake was ~9 times larger in surface area relative to modern. Hydrologic modeling constrained by paleotemperature estimates is used to provide bounds for these past precipitation changes. We also tentatively explore physical mechanisms linking Heinrich events and the regional hydroclimate by comparing freshwater

  6. Changes in Central Aortic Pressure, Endothelial Function and Biomarkers in Hypertensive African-Americans with the Cardiometabolic Syndrome: Comparison of Amlodipine/Olmesartan versus Hydrochlorothiazide/Losartan

    PubMed Central

    Khan, Bobby V.; Merchant, Nadya; Rahman, Syed T.; Ahmad, Mushtaq; Parrott, Janice M.; Umar, Kanwal; Johnson, Julie; Ferdinand, Keith C.

    2013-01-01

    Sixty-six self-identified African-American subjects with stage 1 and 2 hypertension and characteristics of the cardiometabolic syndrome were treated with amlodipine/olmesartan (A/O) versus losartan/hydrochlorothiazide (L/H) for 20 weeks in an open-label, active comparator fashion. Subjects not meeting a blood pressure (BP) value of <125/75 mm Hg on either regimen at week 14 were placed on additional or alternative therapy. After 20 weeks of therapy, systolic BP was reduced by 34.6 ± 4.2 mm Hg in the A/O group and by 27.0 ± 4.1 mm Hg in the L/H group (p = 0.012 A/O vs. L/H). Diastolic BP was reduced by 16.9 ± 2.0 mm Hg in the A/O group and by 12.3 ± 2.0 mm Hg in the L/H group (p = 0.022 A/O vs. L/H). There was a substantial increase in endothelial function of 44 and 103% in the L/H and A/O groups, respectively (p < 0.005 A/O vs. L/H). Central aorta augmentation pressure was significantly reduced by 42% with the A/O treatment, and a smaller, significant reduction of 28% was observed with the L/H treatment (p = 0.034 A/O vs. L/H). There was a reduction in sIL-6 levels of 20 and 33%, a reduction in serum leptin levels of 22 and 40%, and an increase in serum adiponectin of 19 and 46% in the L/H and A/O groups, respectively (p < 0.005 A/O vs. L/H for each biomarker). Treatment with A/O after 14 weeks reduced pulse wave velocity by 22% (p = 0.011 time comparison), whereas L/H treatment had no significant effect. Our findings suggest that, in addition to effective BP reduction, A/O differentially regulates markers of inflammation and obesity, thereby potentially providing greater vascular protection. PMID:24474950

  7. American Pain Society

    MedlinePlus

    ... Management Award Recipients Strong Evidence Still Lacking on Medical Marijuana for Pain Fibromyalgia Has Central Nervous System Origins ... Mayday Fund American Pain Society Offers Guidance on Medical Marijuana for Pain Study Shows Pain Often Improves in ...

  8. Solid-phase peptide head-to-side chain cyclodimerization: discovery of C(2)-symmetric cyclic lactam hybrid α-melanocyte-stimulating hormone (MSH)/agouti-signaling protein (ASIP) analogues with potent activities at the human melanocortin receptors.

    PubMed

    Mayorov, Alexander V; Cai, Minying; Palmer, Erin S; Liu, Zhihua; Cain, James P; Vagner, Josef; Trivedi, Dev; Hruby, Victor J

    2010-10-01

    A novel hybrid melanocortin pharmacophore was designed based on the pharmacophores of the agouti-signaling protein (ASIP), an endogenous melanocortin antagonist, and α-melanocyte-stimulating hormone (α-MSH), an endogenous melanocortin agonist. The designed hybrid ASIP/MSH pharmacophore was explored in monomeric cyclic, and cyclodimeric templates. The monomeric cyclic disulfide series yielded peptides with hMC3R-selective non-competitive binding affinities. The direct on-resin peptide lactam cyclodimerization yielded nanomolar range (25-120 nM) hMC1R-selective full and partial agonists in the cyclodimeric lactam series which demonstrates an improvement over the previous attempts at hybridization of MSH and agouti protein sequences. The secondary structure-oriented pharmacophore hybridization strategy will prove useful in development of unique allosteric and orthosteric melanocortin receptor modulators. This report also illustrates the utility of peptide cyclodimerization for the development of novel GPCR peptide ligands.

  9. The Perspectives of University Administrators towards International Leadership, Study Abroad Programs, and Cooperative Agreements in Central American Public and Private Universities

    ERIC Educational Resources Information Center

    Curbelo Ruiz, Aurelio

    2013-01-01

    As the world becomes globalized by the influence of science and technology, academic institutions in Central America must provide international academic and research opportunities that are conductive to multicultural learning for students, faculty, and staff. Public and private universities in Central America are attempting to increase awareness…

  10. The Perspectives of University Administrators towards International Leadership, Study Abroad Programs, and Cooperative Agreements in Central American Public and Private Universities

    ERIC Educational Resources Information Center

    Curbelo Ruiz, Aurelio

    2013-01-01

    As the world becomes globalized by the influence of science and technology, academic institutions in Central America must provide international academic and research opportunities that are conductive to multicultural learning for students, faculty, and staff. Public and private universities in Central America are attempting to increase awareness…

  11. Cytochrome P450 dependent metabolism of the new designer drug 1-(3-trifluoromethylphenyl)piperazine (TFMPP). In vivo studies in Wistar and Dark Agouti rats as well as in vitro studies in human liver microsomes.

    PubMed

    Staack, Roland F; Paul, Liane D; Springer, Dietmar; Kraemer, Thomas; Maurer, Hans H

    2004-01-15

    1-(3-Trifluoromethylphenyl)piperazine (TFMPP) is a designer drug with serotonergic properties. Previous studies with male Wistar rats (WI) had shown, that TFMPP was metabolized mainly by aromatic hydroxylation. In the current study, it was examined whether this reaction may be catalyzed by cytochrome P450 (CYP)2D6 by comparing TFMPP vs. hydroxy TFMPP ratios in urine from female Dark Agouti rats, a model of the human CYP2D6 poor metabolizer phenotype (PM), male Dark Agouti rats, an intermediate model, and WI, a model of the human CYP2D6 extensive metabolizer phenotype. Furthermore, the human hepatic CYPs involved in TFMPP hydroxylation were identified using cDNA-expressed CYPs and human liver microsomes. Finally, TFMPP plasma levels in the above mentioned rats were compared. The urine studies suggested that TFMPP hydroxylation might be catalyzed by CYP2D6 in humans. Studies using human CYPs showed that CYP1A2, CYP2D6 and CYP3A4 catalyzed TFMPP hydroxylation, with CYP2D6 being the most important enzyme accounting for about 81% of the net intrinsic clearance, calculated using the relative activity factor approach. The hydroxylation was significantly inhibited by quinidine (77%) and metabolite formation in poor metabolizer genotype human liver microsomes was significantly lower (63%) compared to pooled human liver microsomes. Analysis of the plasma samples showed that female Dark Agouti rats exhibited significantly higher TFMPP plasma levels compared to those of male Dark Agouti rats and WI. Furthermore, pretreatment of WI with the CYP2D inhibitor quinine resulted in significantly higher TFMPP plasma levels. In conclusion, the presented data give hints for possible differences in pharmacokinetics in human PM and human CYP2D6 extensive metabolizer phenotype subjects relevant for risk assessment.

  12. Nitrogen-Helium-Argon and Nitrogen Isotope Relationships in Geothermal Fluids from the Central American Volcanic Arc: Mapping Subducted and Crustal Contributions to Volatile Output

    NASA Astrophysics Data System (ADS)

    Fischer, T.; Sharp, Z.; Hilton, D. R.

    2001-12-01

    Volcanic arcs are locations where elements are recycled from the subducted slab, the mantle wedge and the overlying arc crust to the atmosphere and hydrosphere. A fundamental aim of arc-related studies and the MARGINS initiative is to quantify this flux and compare it with subduction zone parameters, such as sediment compositions and subduction rates. As part of the Central American arc study, we report N2, He, and Ar abundance relationships and N-isotope ratios for 7 volcanic centers in Guatemala to complement on-going studies in Costa Rica (see previous abstract). In Guatemala, the arc crust is thicker and older than in Costa Rica and the entire sedimentary sequence on the down-going plate is likely to contribute to the slab flux. The Guatemalan volcanic centers of Amatitlan-Pacaya, Fuego, Moyuta, Tecuamburro, Amatitlan, Zunil and San Marcos have N2/He ratios ranging from 2200 to 8100, typical for arc-related fluids. N2/Ar ratios (40 - 500) and the high N2/He indicate addition of N2 from subducted sediments or arc crust to a mantle derived component (N2/He < 200). The high N2/He ratios of Guatemala, are in contrast to the mantle-derived N2/He ratios measured at Poas, Costa Rica. Nitrogen isotope ratios for the Guatemalan volcanic centers range from δ 15N = +1.0‰ for San Marcos to +5.8‰ for Fuego (δ 15Nair = 0.0‰ ), indicating a sedimentary nitrogen signature. The mantle-derived N2/He ratio for Poas is consistent with a more mantle-like δ 15N of - 1.0‰ . In Guatemala, the highest 3He/4He ratios (7.6 for Pacaya and 7.3 RA for Fuego) correlate with the lowest N2/He ratios (1500 and 2100) and high δ 15N values (+3.8‰ and +5.8‰ ). Lower 3He/4He ratios for Zunil (4.7 RA) and San Marcos (2.2 RA) correlate with N2/He of 5000 and 6600, and lower δ 15N values of +2.3‰ and +1.0‰ , respectively. These N-He relationships suggest that the nitrogen at Pacaya and Fuego is primarily of subducted organic sedimentary origin, with only minor crustal

  13. "A 28-Day Program Ain't Helping the Crack Smoker" -- Perceptions of Effective Drug Abuse Prevention Interventions by North Central Florida African Americans Who Use Cocaine

    ERIC Educational Resources Information Center

    Brown, Emma J.; Hill, Mary Angelique; Giroux, Stacey A.

    2004-01-01

    Cocaine is a major problem in the rural South, but knowledge is limited regarding the impact on African American populations. Purpose: This study of 18-39-year-old black drug users assessed perceptions of contributing factors to drug use and possible interventions. The study design was qualitative-descriptive, utilizing 4 focus groups with 5 rural…

  14. New species of Diabrotica Chevrolat (Coleoptera: Chrysomelidae: Galerucinae) and a key to Diabrotica and related genera: results of a synopsis of North and Central American Diabrotica species

    USDA-ARS?s Scientific Manuscript database

    The following 18 new species of Diabrotica are described and illustrated as a result of the synopsis of North and Centrla American species: D. barclayi nov. sp. Guatemala, D. caveyi nov. sp. Costa Rica, D. costaricensis nov. sp. Costa Rica, D. dmitryogloblini nov. sp. Mexico, D. duckworthae nov. sp....

  15. Performance of container-grown seedlings of American chestnut backcross hybrids BC3 F3 generation in central Louisiana

    Treesearch

    Shi-Jean Susana Sung; Stacy L. Clark; Scott Schlarbaum; Daniel C. Dey; Daniel J. Leduc

    2016-01-01

    Seedlings from two families of the BC3F3 backcross generation of the American chestnut (Castanea dentata) and Chinese chestnut (C. mollissima) were cultured in 2013 in Missouri using the Root Production Method®, a container-based system used to avoid disease problems associated with...

  16. "A 28-Day Program Ain't Helping the Crack Smoker" -- Perceptions of Effective Drug Abuse Prevention Interventions by North Central Florida African Americans Who Use Cocaine

    ERIC Educational Resources Information Center

    Brown, Emma J.; Hill, Mary Angelique; Giroux, Stacey A.

    2004-01-01

    Cocaine is a major problem in the rural South, but knowledge is limited regarding the impact on African American populations. Purpose: This study of 18-39-year-old black drug users assessed perceptions of contributing factors to drug use and possible interventions. The study design was qualitative-descriptive, utilizing 4 focus groups with 5 rural…

  17. Black agouti (ACI) rats show greater drug- and cue-induced reinstatement of methamphetamine-seeking behavior than Fischer 344 and Lewis rats.

    PubMed

    Xi, Jinlei; Kruzich, Paul J

    2007-05-01

    Fischer 344 (F344) and Lewis (LEW) rats differ in methamphetamine self-administration (SA) and methamphetamine-induced reinstatement of previously extinguished behavior. We sought to determine whether genetic background also influences methamphetamine reinforcement efficacy, conditioned reinstatement, and methamphetamine-primed reinstatement of responding in F344, LEW, and Black Agouti (ACI) rats. We implanted rats with jugular catheters and trained them to self-administer methamphetamine (0.06 mg/kg/infusion) under a progressive ratio (PR) schedule of reinforcement during daily 2-h SA sessions. A compound stimulus (light+tone; LT) was paired with each infusion. Dose-dependent intake was determined for each rat. Rats then entered the extinction phase of the experiment where responding resulted in no programmed consequences. Following extinction sessions, rats underwent conditioned reinstatement testing. For conditioned reinstatement, rats received response-contingent presentations of the LT and no methamphetamine. Last, methamphetamine-primed reinstatement test sessions where conducted where subjects received experimenter delivered infusions of methamphetamine (0.06, 0.12, or 0.24 mg/kg). The strains did not differ in PR responding across the doses tested. The ACI rats demonstrated the highest behavioral output during extinction training, conditioned- and methamphetamine-primed reinstatement of previously extinguished behavior compared to the other strains. These data suggest that genetic background differentially influences extinction, conditioned reinstatement and methamphetamine-primed reinstatement in rats.

  18. A Macrocyclic Agouti-Related Protein/[Nle(4),DPhe(7)]α-Melanocyte Stimulating Hormone Chimeric Scaffold Produces Subnanomolar Melanocortin Receptor Ligands.

    PubMed

    Ericson, Mark D; Freeman, Katie T; Schnell, Sathya M; Haskell-Luevano, Carrie

    2017-01-26

    The melanocortin system consists of five receptor subtypes, endogenous agonists, and naturally occurring antagonists. These receptors and ligands have been implicated in numerous biological pathways including processes linked to obesity and food intake. Herein, a truncation structure-activity relationship study of chimeric agouti-related protein (AGRP)/[Nle4,DPhe7]α-melanocyte stimulating hormone (NDP-MSH) ligands is reported. The tetrapeptide His-DPhe-Arg-Trp or tripeptide DPhe-Arg-Trp replaced the Arg-Phe-Phe sequence in the AGRP active loop derivative c[Pro-Arg-Phe-Phe-Xxx-Ala-Phe-DPro], where Xxx was the native Asn of AGRP or a diaminopropionic (Dap) acid residue previously shown to increase antagonist potency at the mMC4R. The Phe, Ala, and Dap/Asn residues were successively removed to generate a 14-member library that was assayed for agonist activity at the mouse MC1R, MC3R, MC4R, and MC5R. Two compounds possessed nanomolar agonist potency at the mMC4R, c[Pro-His-DPhe-Arg-Trp-Asn-Ala-Phe-DPro] and c[Pro-His-DPhe-Arg-Trp-Dap-Ala-DPro], and may be further developed to generate novel melanocortin probes and ligands for understanding and treating obesity.

  19. Defining MC1R regulation in human melanocytes by its agonist α-melanocortin and antagonists agouti signaling protein and β-defensin 3.

    PubMed

    Swope, Viki B; Jameson, Joshua A; McFarland, Kevin L; Supp, Dorothy M; Miller, William E; McGraw, Dennis W; Patel, Mira A; Nix, Matthew A; Millhauser, Glenn L; Babcock, George F; Abdel-Malek, Zalfa A

    2012-09-01

    The melanocortin 1 receptor (MC1R), a G(s) protein-coupled receptor, has an important role in human pigmentation. We investigated the regulation of expression and activity of the MC1R in primary human melanocyte cultures. Human β-defensin 3 (HBD3) acted as an antagonist for MC1R, inhibiting the α-melanocortin (α-melanocyte-stimulating hormone (α-MSH))-induced increase in the activities of adenylate cyclase and tyrosinase, the rate-limiting enzyme for melanogenesis. α-Melanocortin and forskolin, which activate adenylate cyclase, and 12-O-tetradecanoylphorbol-13-acetate, which activates protein kinase C, increased, whereas exposure to UV radiation reduced, MC1R gene and membrane protein expression. Brief treatment with α-MSH resulted in MC1R desensitization, whereas continuous treatment up to 3 hours caused a steady rise in cAMP, suggesting receptor recycling. Pretreatment with agouti signaling protein or HBD3 prohibited responsiveness to α-MSH, but not forskolin, suggesting receptor desensitization by these antagonists. Melanocytes from different donors expressed different levels of the G protein-coupled receptor kinases (GRKs) 2, 3, 5, and 6, as well as β-arrestin 1. Therefore, in addition to the MC1R genotype, regulation of MC1R expression and activity is expected to affect human pigmentation and the responses to UV.

  20. Molecular and genetic characterization of a radiation-induced structural rearrangement in mouse chromosome 2 causing mutations at the limb deformity and agouti loci.

    PubMed

    Woychik, R P; Generoso, W M; Russell, L B; Cain, K T; Cacheiro, N L; Bultman, S J; Selby, P B; Dickinson, M E; Hogan, B L; Rutledge, J C

    1990-04-01

    Molecular characterization of mutations in the mouse, particularly those involving agent-induced major structural alterations, is proving to be useful for correlating the structure and expression of individual genes with their function in the whole organism. Here we present the characterization of a radiation-induced mutation that simultaneously generated distinct alleles of both the limb deformity (ld) and agouti (a) loci, two developmentally important regions of chromosome 2 normally separated by 20 centimorgans. Cytogenetic analysis revealed that an interstitial segment of chromosome 17 (17B- 17C; or, possibly, 17A2-17B) had been translocated into the distal end of chromosome 2, resulting in a smaller-than-normal chromosome 17 (designated 17del) and a larger form of chromosome 2 (designated 2(17). Additionally, a large interstitial segment of the 2(17) chromosome, immediately adjacent and proximal to the insertion site, did not match bands 2E4-2H1 at corresponding positions on a normal chromosome 2. Molecular analysis detected a DNA rearrangement in which a portion of the ld locus was joined to sequences normally tightly linked to the a locus. This result, along with the genetic and cytogenetic data, suggests that the alleles of ld and a in this radiation-induced mutation, designated ldIn2 and ajIn2, were associated with DNA breaks caused by an inversion of an interstitial segment in the 2(17) chromosome.

  1. The influence of pharmacogenetics on opioid analgesia: studies with codeine and oxycodone in the Sprague-Dawley/Dark Agouti rat model.

    PubMed

    Cleary, J; Mikus, G; Somogyi, A; Bochner, F

    1994-12-01

    In the Sprague-Dawley (SD) rat, the O-demethylation of codeine to morphine is catalyzed by cytochrome P4502D1 (CYP2D1), which is absent in the female Dark Agouti (DA) rat. Oxycodone is similar in structure to codeine but, in contrast, has an analgesic potency in humans similar to morphine. The aim of the study was to test whether the DA rat and the SD rat pretreated with the CYP2D1 inhibitor quinine showed attenuation in analgesia to codeine and oxycodone. With the use of the tail flick model, dose-response curves were constructed to codeine, morphine, oxycodone and oxymorphone (the O-demethylated metabolite of oxycodone) in both rat strains. Codeine did not induce analgesia in the DA rat and there was a 60% reduction in codeine analgesia in the SD rat pretreated with quinine in comparison to the untreated SD rat. In the DA rat, the ED50 to oxycodone was increased 10-fold but there was a significant (P = .0001) prolongation in the duration of analgesia in comparison to that in the untreated SD rat. In the quinine-pretreated SD rat, there was no reduction in oxycodone analgesia but the duration of analgesia was also prolonged. It was concluded that 1) codeine-mediated analgesia requires the formation of morphine through the functional activity of CYP2D1 and 2) oxycodone-mediated analgesia may only be partly dependent on CYP2D1.

  2. Signal transducer and activator of transcription (stat) binding sites but not stat3 are required for fasting-induced transcription of agouti-related protein messenger ribonucleic acid.

    PubMed

    Kaelin, Christopher B; Gong, Lijie; Xu, Allison Wanting; Yao, Fayi; Hockman, Kristin; Morton, Gregory J; Schwartz, Michael W; Barsh, Gregory S; MacKenzie, Robert G

    2006-10-01

    Energy homeostasis depends on the regulation of hypothalamic neurons by leptin, an adipocyte hormone whose circulating levels communicate body energy stores. Leptin activates the transcription factor signal transducer and activator of transcription 3 (Stat3) in hypothalamic neurons, including neuronal subtypes producing Agouti-related protein (Agrp), a neuropeptide that stimulates feeding. Previous studies have suggested a model in which high levels of Agrp transcription during fasting represent a default state that is actively repressed by phospho-Stat3 induced by leptin signaling in the fed state. We identify putative Stat3 binding elements in the Agrp promoter that have been highly conserved during vertebrate evolution. Using a reporter assay in transgenic mice that faithfully recapitulates normal regulation of Agrp, we show that these sites are required, but in a way opposite to that predicted by the existing model: mutation of the sites leads to a default state characterized by a low level of Agrp transcription and insensitivity to fasting. We also find that removing activatable Stat3 from Agrp neurons has no detectable effect on steady-state levels of Agrp mRNA in the fed or fasted state. These results suggest a new model for transcriptional regulation of orexigenic neuropeptides in which the default level of expression is low in the fed state, and transcriptional activation in response to fasting is mediated by factors other than Stat3.

  3. Transplanting a Western-Style Journalism Education to the Central Asian Republics of the Former Soviet Union: Experiences and Challenges at the American University of Central Asia in Kyrgyzstan

    ERIC Educational Resources Information Center

    Skochilo, Elena; Toralieva, Gulnura; Freedman, Eric; Shafer, Richard

    2013-01-01

    Western standards of journalism education, as well as western professional journalistic practices, have had difficulty taking root in the five independent countries of formerly Soviet Central Asia. This essay examines the experience of one university's Department of Journalism and Mass Communication since 1997 and the challenges it faces,…

  4. Transplanting a Western-Style Journalism Education to the Central Asian Republics of the Former Soviet Union: Experiences and Challenges at the American University of Central Asia in Kyrgyzstan

    ERIC Educational Resources Information Center

    Skochilo, Elena; Toralieva, Gulnura; Freedman, Eric; Shafer, Richard

    2013-01-01

    Western standards of journalism education, as well as western professional journalistic practices, have had difficulty taking root in the five independent countries of formerly Soviet Central Asia. This essay examines the experience of one university's Department of Journalism and Mass Communication since 1997 and the challenges it faces,…

  5. Peroxisome Proliferator-Activated Receptor γ Controls Ingestive Behavior, Agouti-Related Protein, and Neuropeptide Y mRNA in the Arcuate Hypothalamus

    PubMed Central

    Garretson, John T.; Teubner, Brett J.W.; Grove, Kevin L.; Vazdarjanova, Almira; Ryu, Vitaly

    2015-01-01

    Peroxisome proliferator-activated receptor γ (PPARγ) is clinically targeted for type II diabetes treatment; however, rosiglitazone (ROSI), a PPARγ agonist, increases food intake and body/fat mass as side-effects. Mechanisms for these effects and the role of PPARγ in feeding are not understood. Therefore, we tested this role in Siberian hamsters, a model of human energy balance, and C57BL/6 mice. We tested the following: (1) how ROSI and/or GW9662 (2-chloro-5-nitro-N-phenylbenzamide; PPARγ antagonist) injected intraperitoneally or into the third ventricle (3V) affected Siberian hamster feeding behaviors; (2) whether food deprivation (FD) co-increases agouti-related protein (AgRP) and PPARγ mRNA expression in Siberian hamsters and mice; (3) whether intraperitoneally administered ROSI increases AgRP and NPY in ad libitum-fed animals; (4) whether intraperitoneally administered PPARγ antagonism blocks FD-induced increases in AgRP and NPY; and finally, (5) whether intraperitoneally administered PPARγ modulation affects plasma ghrelin. Third ventricular and intraperitoneally administered ROSI increased food hoarding and intake for 7 d, an effect attenuated by 3V GW9662, and also prevented (intraperitoneal) FD-induced feeding. FD hamsters and mice increased AgRP within the arcuate hypothalamic nucleus with concomitant increases in PPARγ exclusively within AgRP/NPY neurons. ROSI increased AgRP and NPY similarly to FD, and GW9662 prevented FD-induced increases in AgRP and NPY in both species. Neither ROSI nor GW9662 affected plasma ghrelin. Thus, we demonstrated that PPARγ activation is sufficient to trigger food hoarding/intake, increase AgRP/NPY, and possibly is necessary for FD-induced increases in feeding and AgRP/NPY. These findings provide initial evidence that FD-induced increases in AgRP/NPY may be a direct PPARγ-dependent process that controls ingestive behaviors. PMID:25788674

  6. Calcium and dairy products inhibit weight and fat regain during ad libitum consumption following energy restriction in Ap2-agouti transgenic mice.

    PubMed

    Sun, Xiaocun; Zemel, Michael B

    2004-11-01

    We demonstrated previously that dietary calcium suppression of calcitriol reduces adipocyte Ca(2+), suppresses lipogenesis, and increases lipid utilization during energy restriction. Notably, dairy calcium sources exert markedly greater effects. To determine the effects of dietary calcium and dairy products on energy partitioning during subsequent refeeding, we induced obesity in aP2-agouti transgenic mice with a high-fat/high-sucrose diet, then restricted energy intake from a high-calcium (1.3%) diet for 6 wk to induce fat loss, and then provided free access to a low-calcium (0.4%) diet or to high-calcium (1.3%) diets that utilized either calcium-fortified foods or dairy products (milk or yogurt) for 6 wk. Refeeding the low-calcium diet caused the regain of all weight and fat, whereas all high-calcium diets reduced fat gain by 55% (P < 0.01). All high-calcium diets stimulated adipose tissue uncoupling protein (UCP)2 and skeletal muscle UCP3 expression (P < 0.001) and slightly increased core temperature (P = 0.136), but only the dairy-based diets elicited a marked (>10-fold, P < 0.001) increase in skeletal muscle peroxisome proliferator-activated receptor-alpha expression. All 3 high-calcium diets produced significant increases in lipolysis, decreases in fatty acid synthase expression and activity, and reduced fat regain (P < 0.03), but the 2 dairy-containing high-calcium diets exerted significantly greater effects on regain (P < 0.01). Thus, high-Ca diets elicit a shift in energy partitioning and reduction of weight gain during refeeding, with dairy Ca sources exerting markedly greater effects.

  7. Ghrelin receptors mediate ghrelin-induced excitation of agouti-related protein/neuropeptide Y but not pro-opiomelanocortin neurons.

    PubMed

    Chen, Shao-Rui; Chen, Hong; Zhou, Jing-Jing; Pradhan, Geetali; Sun, Yuxiang; Pan, Hui-Lin; Li, De-Pei

    2017-08-01

    Ghrelin increases food intake and body weight by stimulating orexigenic agouti-related protein (AgRP)/neuropeptide Y (NPY) neurons and inhibiting anorexic pro-opiomelanocortin (POMC) neurons in the hypothalamus. Growth hormone secretagogue receptor (Ghsr) mediates the effect of ghrelin on feeding behavior and energy homeostasis. However, the role of Ghsr in the ghrelin effect on these two populations of neurons is unclear. We hypothesized that Ghsr mediates the effect of ghrelin on AgRP and POMC neurons. In this study, we determined whether Ghsr similarly mediates the effects of ghrelin on AgRP/NPY and POMC neurons using cell type-specific Ghsr-knockout mice. Perforated whole-cell recordings were performed on green fluorescent protein-tagged AgRP/NPY and POMC neurons in the arcuate nucleus in hypothalamic slices. In Ghsr(+/+) mice, ghrelin (100 nM) significantly increased the firing activity of AgRP/NPY neurons but inhibited the firing activity of POMC neurons. In Ghsr(-/-) mice, the excitatory effect of ghrelin on AgRP/NPY neurons was abolished. Ablation of Ghsr also eliminated ghrelin-induced increases in the frequency of GABAergic inhibitory postsynaptic currents of POMC neurons. Strikingly, ablation of Ghsr converted the ghrelin effect on POMC neurons from inhibition to excitation. Des-acylated ghrelin had no such effect on POMC neurons in Ghsr(-/-) mice. In both Ghsr(+/+) and Ghsr(-/-) mice, blocking GABAA receptors with gabazine increased the basal firing activity of POMC neurons, and ghrelin further increased the firing activity of POMC neurons in the presence of gabazine. Our findings provide unequivocal evidence that Ghsr is essential for ghrelin-induced excitation of AgRP/NPY neurons. However, ghrelin excites POMC neurons through an unidentified mechanism that is distinct from conventional Ghsr. © 2017 International Society for Neurochemistry.

  8. Strain differences in cytochrome P450 mRNA and protein expression, and enzymatic activity among Sprague Dawley, Wistar, Brown Norway and Dark Agouti rats.

    PubMed

    Nishiyama, Yoshihiro; Nakayama, Shouta M M; Watanabe, Kensuke P; Kawai, Yusuke K; Ohno, Marumi; Ikenaka, Yoshinori; Ishizuka, Mayumi

    2016-05-03

    Rat cytochrome P450 (CYP) exhibits inter-strain differences, but their analysis has been scattered across studies under different conditions. To identify these strain differences in CYP more comprehensively, mRNA expression, protein expression and metabolic activity among Wistar (WI), Sprague Dawley (SD), Dark Agouti (DA) and Brown Norway (BN) rats were compared. The mRNA level and enzymatic activity of CYP1A1 were highest in SD rats. The rank order of Cyp3a2 mRNA expression mirrored its protein expression, i.e., DA>BN>SD>WI, and was similar to the CYP3A2-dependent warfarin metabolic activity, i.e., DA>SD>BN>WI. These results suggest that the strain differences in CYP3A2 enzymatic activity are caused by differences in mRNA expression. Cyp2b1 mRNA levels, which were higher in DA rats, did not correlate with its protein expression or enzymatic activity. This suggests that the strain differences in enzymatic activity are not related to Cyp2b1 mRNA expression. In conclusion, WI rats tended to have the lowest CYP1A1, 2B1 and 3A2 mRNA expression, protein expression and enzymatic activity among the strains. In addition, SD rats had the highest CYP1A1 mRNA expression and activity, while DA rats had higher CYP2B1 and CYP3A2 mRNA and protein expression. These inter-strain differences in CYP could influence pharmacokinetic considerations in preclinical toxicological studies.

  9. Maternal exposure to bisphenol A and genistein has minimal effect on Avy/a offspring coat color but favors birth of agouti over nonagouti mice

    PubMed Central

    Rosenfeld, Cheryl S.; Sieli, Paizlee T.; Warzak, Denise A.; Ellersieck, Mark R.; Pennington, Kathleen A.; Roberts, R. Michael

    2013-01-01

    Reports that maternal diet influences coat color in mouse offspring carrying the agouti Avy allele have received considerable attention because the range, from pseudoagouti (brown) to yellow, predicts adult health outcomes, especially disposition toward obesity and diabetes, in yellower mice. Bisphenol A (BPA), an endocrine-disrupting compound with estrogenic properties, fed to a/a dams harboring Avy/a conceptuses has been reported to induce a significant shift toward yellower mice, whereas consumption of either genistein (G) alone or in combination with BPA led to greater numbers of healthy, brown offspring. Groups of C57/B6 a/a females, which are nonagouti, were fed either a phytoestrogen-free control diet or one of six experimental diets: diets 1–3 contained BPA (50 mg, 5 mg, and 50 μg BPA/kg food, respectively); diet 4 contained G (250 mg/kg food); diet 5 contained G plus BPA (250 and 50 mg/kg food, respectively); and diet 6 contained 0.1 μg of ethinyl estradiol (EE)/kg food. Mice were bred to Avy/a males over multiple parities. In all, 2,824 pups from 426 litters were born. None of the diets provided any significant differences in relative numbers of brown, yellow, or intermediate coat color Avy/a offspring. However, BPA plus G (P < 0.0001) and EE diets (P = 0.005), but not the four others, decreased the percentage of black (a/a) to Avy/a offspring from the expected Mendelian ratio of 1:1. Data suggest that Avy/a conceptuses, which may possess a so-called “thrifty genotype,” are at a competitive advantage over a/a conceptuses in certain uterine environments. PMID:23267115

  10. Divergent regulation of hypothalamic neuropeptide Y and agouti-related protein by photoperiod in F344 rats with differential food intake and growth.

    PubMed

    Ross, A W; Johnson, C E; Bell, L M; Reilly, L; Duncan, J S; Barrett, P; Heideman, P D; Morgan, P J

    2009-07-01

    Hypothalamic genes involved in food intake and growth regulation were studied in F344 rats in response to photoperiod. Two sub-strains were identified: F344/NHsd (F344/N) and F344/NCrHsd (F344/NCr); sensitive and relatively insensitive to photoperiod respectively. In F344/N rats, marked, but opposite, changes in the genes for neuropeptide Y (NPY) (+97.5%) and agouti-related protein (AgRP) (-39.3%) expression in the arcuate nucleus were observed in response to short (8 : 16 h light/dark cycle, SD) relative to long (16 : 8 h light/dark cycle, LD) day photoperiods. Changes were associated with both reduced food intake and growth. Expression of the genes for cocaine and amphetamine-regulated transcript (CART) and pro-opiomelanocortin (POMC) in the arcuate nucleus was unchanged by photoperiod. POMC in the ependymal layer around the third ventricle was markedly inhibited by SD. Parallel decreases in the genes for growth hormone-releasing hormone (GHRH) and somatostatin (Somatostatin) mRNA in the arcuate nucleus and Somatostatin in the periventricular nucleus were observed in SD. Serum levels of insulin-like growth factor (IGF)-1 and insulin were lower in F344/N rats in SD, whereas neither leptin nor corticosterone levels were affected. By contrast, F344/NCr rats that show only minor food intake and growth rate changes showed minimal responses in these genes and hormones. Thus, NPY/AgRP neurones may be pivotal to the photoperiodic regulation of food intake and growth. Potentially, the SD increase in NPY expression may inhibit growth by decreasing GHRH and Somatostatin expression, whereas the decrease in AgRP expression probably leads to reduced food intake. The present study reveals an atypical and divergent regulation of NPY and AgRP, which may relate to their separate roles with respect to growth and food intake, respectively.

  11. Genetic analysis of the Yavapai Native Americans from West-Central Arizona using the Illumina MiSeq FGx™ forensic genomics system.

    PubMed

    Wendt, Frank R; Churchill, Jennifer D; Novroski, Nicole M M; King, Jonathan L; Ng, Jillian; Oldt, Robert F; McCulloh, Kelly L; Weise, Jessica A; Smith, David Glenn; Kanthaswamy, Sreetharan; Budowle, Bruce

    2016-09-01

    Forensically-relevant genetic markers were typed for sixty-two Yavapai Native Americans using the ForenSeq™ DNA Signature Prep Kit.These data are invaluable to the human identity community due to the greater genetic differentiation among Native American tribes than among other subdivisions within major populations of the United States. Autosomal, X-chromosomal, and Y-chromosomal short tandem repeat (STR) and identity-informative (iSNPs), ancestry-informative (aSNPs), and phenotype-informative (pSNPs) single nucleotide polymorphism (SNP) allele frequencies are reported. Sequence-based allelic variants were observed in 13 autosomal, 3 X, and 3 Y STRs. These observations increased observed and expected heterozygosities for autosomal STRs by 0.081±0.068 and 0.073±0.063, respectively, and decreased single-locus random match probabilities by 0.051±0.043 for 13 autosomal STRs. The autosomal random match probabilities (RMPs) were 2.37×10-26 and 2.81×10-29 for length-based and sequence-based alleles, respectively. There were 22 and 25 unique Y-STR haplotypes among 26 males, generating haplotype diversities of 0.95 and 0.96, for length-based and sequencebased alleles, respectively. Of the 26 haplotypes generated, 17 were assigned to haplogroup Q, three to haplogroup R1b, two each to haplogroups E1b1b and L, and one each to haplogroups R1a and I1. Male and female sequence-based X-STR random match probabilities were 3.28×10-7 and 1.22×10-6, respectively. The average observed and expected heterozygosities for 94 iSNPs were 0.39±0.12 and 0.39±0.13, respectively, and the combined iSNP RMP was 1.08×10-32. The combined STR and iSNP RMPs were 2.55×10-58 and 3.02×10-61 for length-based and sequence-based STR alleles, respectively. Ancestry and phenotypic SNP information, performed using the ForenSeq™ Universal Analysis Software, predicted black hair, brown eyes, and some probability of East Asian ancestry for all but one sample that clustered between European and

  12. Comparison of Metabolic Syndrome Indicators in Two Samples of Central and South Americans Living in the Washington, D.C. Area in 1993-1994 and 2008-2009: Secular Changes in Metabolic Syndrome in Hispanics.

    PubMed

    Gill, Regina; Jackson, Robert T; Duane, Marguerite; Miner, Allison; Khan, Saira A

    2017-08-05

    The Central and South American populations are growing rapidly in the US; however, there is a paucity of information about their health status. Objectives: we estimated the prevalence of metabolic syndrome (MetS) and its individual components from two cohorts of Central and South Americans. Methods: This cross-sectional, medical record extraction survey sampled 1641 adults from a Washington, D.C clinic. A questionnaire was used to collect socio-demographic, medical history, anthropometric, biochemical, and clinical data. Results: among the 1993-1994 cohort, the MetS prevalence was 19.7%. The most prevalent MetS components were low high-density lipoprotein (HDL) cholesterol (40.4% men and 51.3% women), elevated triglycerides (40.9% men and 33.1% women), and high body mass index (BMI) ≥ 25 kg/m² (27.6% men and 36.6% women). The overall prevalence of MetS in the 2008-2009 cohort was 28%. The most common abnormal metabolic indicator was an elevated BMI ≥ 25 kg/m² (75.6%). 43.2% of men and 50.7% of women had HDL levels below normal, while the prevalence of hypertriglyceridemia was 46.5% and 32.5% for men and women, respectively. Conclusion: the prevalence of MetS was significantly greater in 2008-2009 compared with 1993-1994 (p ≤ 0.05). Dyslipidemia and high BMI have increased. Although similar components were identified in both the 1993-1994 and 2008-2009 study populations, the risks of MetS have increased over time.

  13. Comparison of Metabolic Syndrome Indicators in Two Samples of Central and South Americans Living in the Washington, D.C. Area in 1993–1994 and 2008–2009: Secular Changes in Metabolic Syndrome in Hispanics

    PubMed Central

    Gill, Regina; Jackson, Robert T.; Duane, Marguerite; Miner, Allison

    2017-01-01

    The Central and South American populations are growing rapidly in the US; however, there is a paucity of information about their health status. Objectives: we estimated the prevalence of metabolic syndrome (MetS) and its individual components from two cohorts of Central and South Americans. Methods: This cross-sectional, medical record extraction survey sampled 1641 adults from a Washington, D.C clinic. A questionnaire was used to collect socio-demographic, medical history, anthropometric, biochemical, and clinical data. Results: among the 1993–1994 cohort, the MetS prevalence was 19.7%. The most prevalent MetS components were low high-density lipoprotein (HDL) cholesterol (40.4% men and 51.3% women), elevated triglycerides (40.9% men and 33.1% women), and high body mass index (BMI) ≥ 25 kg/m2 (27.6% men and 36.6% women). The overall prevalence of MetS in the 2008–2009 cohort was 28%. The most common abnormal metabolic indicator was an elevated BMI ≥ 25 kg/m2 (75.6%). 43.2% of men and 50.7% of women had HDL levels below normal, while the prevalence of hypertriglyceridemia was 46.5% and 32.5% for men and women, respectively. Conclusion: the prevalence of MetS was significantly greater in 2008–2009 compared with 1993–1994 (p ≤ 0.05). Dyslipidemia and high BMI have increased. Although similar components were identified in both the 1993–1994 and 2008–2009 study populations, the risks of MetS have increased over time. PMID:28783050

  14. Glacial-eustatic sea-level fluctuation curve for Carboniferous-Permian boundary strata based on outcrops in the North American Midcontinent and North-Central Texas

    SciTech Connect

    Boardman, D.R. . School of Geology)

    1993-02-01

    Based on lithologic and faunal analysis of uppermost Carboniferous through Lower Permian strata (Wabaunsee through lower Chase groups) exposed from southeastern Nebraska through north-central Oklahoma, a preliminary glacial-eustatic sea-level fluctuation curve is presented herein. In addition to the sea-level curve presented for the Midcontinent region, one for coeval outcropping strata (middle and upper Cisco Group) of the Eastern Shelf of the Midland Basin is also presented based on similar criteria. This sea-level curve is derived from new field studies as well as a refinement of earlier curves presented by Harrison (1973), and Boardman and Malinky (1985). The conclusion on the nature of the Carboniferous-Permian boundary strata cyclothems in the Midcontinent is mirrored by the results of that from North-Central Texas. Each of the primary biostratigraphically-based picks for the Carboniferous-Permian boundary coincide with either intermediate of major cycles in both study areas. Utilization of a glacial-eustatic maximum transgressive event for the Carboniferous-Permian boundary should result in a more correlatable level for intercontinental correlation.

  15. Estimativas de possiveis recursos de petroleo e gas na America Central e na America do Sul [Estimates of possible petroleum and gas resources in Central American and South America

    USGS Publications Warehouse

    Schenk, C.S.

    2001-01-01

    O U.S. Geological Survey recentemente completou estimativas de possíveis recursos de petróleo e gás em 130 áreas petrolíferas pré-determinadas no mundo (USGS, 2000). Vinte e três destas áreas ficam na América do Sul, na América Central, e no Caribe (fig. 1). Os resultados estão apresentados na tabela 1. Nas 23 áreas, estimamos um total de 105 BBO e um total de 487 TCFG. A região composta de América Central mais América do Sul ficou em terceiro lugar no mundo em termos de possíveis recursos de petróleo e gás. No primeiro lugar ficou o Oriente Médio e no segundo lugar ficou a antiga União Soviética (USGS, 2000). As áreas com maiores probabilidades de encontrar depósitos gigantes de petróleo e gás se localizam nas áreas do Oceano Atlântico começando com a Bacia de Santos no sul até a Bacia Guyana-Suriname no norte. As possibilidades de existirem depósitos gigantes são maiores nas áreas submersas do mar até profundidades de 3,600 m. Diversos depósitos gigantes de petróleo foram descobertos no mar na Bacia de Campos e ainda podem serem encontrados depósitos similares na Bacia de Campos e suas imediações.

  16. "It Really Is Not Just Gay, but African American Gay": The Impact of Community and Church on the Experiences of Black Lesbians Living in North Central Florida.

    PubMed

    Walsh, Clare F

    2016-09-01

    The experiences of Black lesbians highlight the unique circumstance found at the intersection of sexuality, race, and gender. However, most sexuality research tends to focus on White lesbians and White gay men, and most race research tends to focus on Black heterosexuals. Furthermore, research on the Black gay community tends to focus on those living in the Northeast or on the West Coast, neglecting experiences of those living in the more politically, socially, and religiously conservative South. This article draws on data obtained from semistructured interviews with 12 Black lesbians living in north central Florida, exploring their perspectives as they negotiate a social world of intersecting oppressions. Participants especially highlight how they contextualized their sexuality in racialized terms and negotiated it in racially defined communities.

  17. Climate Change and the Central American Mid-summer Drought - The Importance of Changing Precipitation Patterns for Food and Water Security

    NASA Astrophysics Data System (ADS)

    Maurer, E. P.; Stewart, I. T.; Sundstrom, W.; Bacon, C. M.

    2016-12-01

    In addition to periodic long-term drought, much of Central America experiences a rainy season with two peaks separated by a dry period of weeks to over a month in duration, termed the mid-summer drought (MSD). Food and water security for smallholder farmers in the region hinge on accommodating this phenomenon, anticipating its arrival and estimating its duration. Model output from 1980 through the late 21st century projects changes in precipitation amount, variability, and timing, with potential to affect regional food production. Using surveys of farmer experiences in conjunction with gridded daily precipitation for a historic period on multiple scales, and with projections through the 21st century, we characterize the MSD across much of Central America using four measures: onset date, duration, intensity, and minimum, and test for significant changes. Our findings indicate that the most significant changes are for the duration, which, by the end of the century, is projected to increase by an average of over a week, and the MSD minimum precipitation, which is projected to decline by an average of over 26%, with statistically significant changes for most of Nicaragua, Honduras, El Salvador, and Guatemala (assuming a higher emissions pathway through the 21st century). These changes toward a longer and drier MSD have important implications for food and water security for vulnerable communities through the region. We find that for the four metrics the changes in interannual variability are small compared to historical variability, and are generally statistically insignificant. New farmer survey results are compared to findings from our climate analysis for the historic period, are used to interpret what MSD characteristics are of greatest interest locally, and are used for the development of adaptation strategies.

  18. Testing for shared biogeographic history in the lower Central American freshwater fish assemblage using comparative phylogeography: concerted, independent, or multiple evolutionary responses?

    PubMed Central

    Bagley, Justin C; Johnson, Jerald B

    2014-01-01

    A central goal of comparative phylogeography is determining whether codistributed species experienced (1) concerted evolutionary responses to past geological and climatic events, indicated by congruent spatial and temporal patterns (“concerted-response hypothesis”); (2) independent responses, indicated by spatial incongruence (“independent-response hypothesis”); or (3) multiple responses (“multiple-response hypothesis”), indicated by spatial congruence but temporal incongruence (“pseudocongruence”) or spatial and temporal incongruence (“pseudoincongruence”). We tested these competing hypotheses using DNA sequence data from three livebearing fish species codistributed in the Nicaraguan depression of Central America (Alfaro cultratus, Poecilia gillii, and Xenophallus umbratilis) that we predicted might display congruent responses due to co-occurrence in identical freshwater drainages. Spatial analyses recovered different subdivisions of genetic structure for each species, despite shared finer-scale breaks in northwestern Costa Rica (also supported by phylogenetic results). Isolation-with-migration models estimated incongruent timelines of among-region divergences, with A. cultratus and Xenophallus populations diverging over Miocene–mid-Pleistocene while P. gillii populations diverged over mid-late Pleistocene. Approximate Bayesian computation also lent substantial support to multiple discrete divergences over a model of simultaneous divergence across shared spatial breaks (e.g., Bayes factor [B10] = 4.303 for Ψ [no. of divergences] > 1 vs. Ψ = 1). Thus, the data support phylogeographic pseudoincongruence consistent with the multiple-response hypothesis. Model comparisons also indicated incongruence in historical demography, for example, support for intraspecific late Pleistocene population growth was unique to P. gillii, despite evidence for finer-scale population expansions in the other taxa. Empirical tests for phylogeographic congruence

  19. Sequential development of platform to off-platform facies of the great American carbonate bank in the central Appalachians: chapter 15

    USGS Publications Warehouse

    Brezinski, David K.; Taylor, John F.; Repetski, John E.

    2012-01-01

    During deposition of the Tippecanoe megasequence, the peritidal shelf cycles were reestablished during deposition of the St. Paul Group. The vertical stacking of lithologies in the Row Park and New Market Limestones represents transgressive and regressice facies of a third-order deepening event. This submergence reached its maximum deepening within the lower Row Park Limestone and extended with the Nittany arch region with deposition of equivalent Loysburg Formation.. Shallow tidal-flat deposits were bordered to the south and east by deep-water ramp deposits of the Lincolnshire Formation. The St. Paul Group is succeeded upsection by ramp facies of the Chamersberg and the Edinburg Formations in the Great Valley, whereas shallow-shelf sedimentation continued in the Nittany-arch area with the depostion of the Hatter Limestoen and the Snyder and Linden Hall Formations. Carbonate deposition on the great American carbonate bank was brought to an end when it was buried beneath clastic flysch deposits of the Martinsberg Formation. Foundering of the bamk was diachronus, and the flysch seidments prograded from east to west.

  20. Peripherally inserted central catheter - insertion

    MedlinePlus

    ... nontunneled central venous catheters. In: Mauro MA, Murphy KPJ, Thomson KR, et al., eds. Image-Guided Interventions . ... by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is ...

  1. Influence of site differences between urban and rural American and Central European opioid-dependent pregnant women and neonatal outcome characteristics.

    PubMed

    Baewert, Andjela; Jagsch, Reinhold; Winklbaur, Bernadette; Kaiser, Gerda; Thau, Kenneth; Unger, Annemarie; Aschauer, Constantin; Weninger, Manfred; Metz, Verena

    2012-01-01

    Multi-center trials enable the recruitment of larger study samples, although results might be influenced by site-specific factors. Site differences of a multi-center prospective double-blind, double-dummy randomized controlled trial (7 centers: Central Europe (Vienna)/USA (3 urban/3 rural centers)) comparing safety and efficacy of methadone and buprenorphine in pregnant opioid-dependent women and their neonates. Urban US women had the highest rate of concomitant opioid (p = 0.050) and cocaine consumption (p = 0.003), the highest dropout rate (p = 0.001), and received the lowest voucher sums (p = 0.001). Viennese neonates had significantly higher Apgar scores 1 min (p = 0.001) and 5 min after birth (p < 0.001) and were more often born by cesarean section (p = 0.024). Rural US newborns had a significantly shorter neonatal abstinence syndrome treatment duration compared to Viennese and urban US sites (p = 0.006), in addition to other site-specific differences, suggesting a more severely affected group of women in the urban US sites. This clinical trial represents a role model for pharmacological treatment in this unique sample of pregnant women and demonstrates the clinical importance of considering site-specific factors in research and clinical practice. Copyright © 2012 S. Karger AG, Basel.

  2. Influence of Site Differences between Urban and Rural American and Central European Opioid-Dependent Pregnant Women and Neonatal Outcome Characteristics

    PubMed Central

    Baewert, Andjela; Jagsch, Reinhold; Winklbaur, Bernadette; Kaiser, Gerda; Thau, Kenneth; Unger, Annemarie; Aschauer, Constantin; Weninger, Manfred; Metz, Verena

    2012-01-01

    Background Multi-center trials enable the recruitment of larger study samples, although results might be influenced by site-specific factors. Methods Site differences of a multi-center prospective double-blind, double-dummy randomized controlled trial (7 centers: Central Europe (Vienna)/USA (3 urban/3 rural centers)) comparing safety and efficacy of methadone and buprenorphine in pregnant opioid-dependent women and their neonates. Results Urban US women had the highest rate of concomitant opioid (p = 0.050) and cocaine consumption (p = 0.003), the highest dropout rate (p = 0.001), and received the lowest voucher sums (p = 0.001). Viennese neonates had significantly higher Apgar scores 1 min (p = 0.001) and 5 min after birth (p < 0.001) and were more often born by cesarean section (p = 0.024). Rural US newborns had a significantly shorter neonatal abstinence syndrome treatment duration compared to Viennese and urban US sites (p = 0.006), in addition to other site-specific differences, suggesting a more severely affected group of women in the urban US sites. Conclusion This clinical trial represents a role model for pharmacological treatment in this unique sample of pregnant women and demonstrates the clinical importance of considering site-specific factors in research and clinical practice. PMID:22354163

  3. Peroxisome proliferator-activated receptor γ controls ingestive behavior, agouti-related protein, and neuropeptide Y mRNA in the arcuate hypothalamus.

    PubMed

    Garretson, John T; Teubner, Brett J W; Grove, Kevin L; Vazdarjanova, Almira; Ryu, Vitaly; Bartness, Timothy J

    2015-03-18

    Peroxisome proliferator-activated receptor γ (PPARγ) is clinically targeted for type II diabetes treatment; however, rosiglitazone (ROSI), a PPARγ agonist, increases food intake and body/fat mass as side-effects. Mechanisms for these effects and the role of PPARγ in feeding are not understood. Therefore, we tested this role in Siberian hamsters, a model of human energy balance, and C57BL/6 mice. We tested the following: (1) how ROSI and/or GW9662 (2-chloro-5-nitro-N-phenylbenzamide; PPARγ antagonist) injected intraperitoneally or into the third ventricle (3V) affected Siberian hamster feeding behaviors; (2) whether food deprivation (FD) co-increases agouti-related protein (AgRP) and PPARγ mRNA expression in Siberian hamsters and mice; (3) whether intraperitoneally administered ROSI increases AgRP and NPY in ad libitum-fed animals; (4) whether intraperitoneally administered PPARγ antagonism blocks FD-induced increases in AgRP and NPY; and finally, (5) whether intraperitoneally administered PPARγ modulation affects plasma ghrelin. Third ventricular and intraperitoneally administered ROSI increased food hoarding and intake for 7 d, an effect attenuated by 3V GW9662, and also prevented (intraperitoneal) FD-induced feeding. FD hamsters and mice increased AgRP within the arcuate hypothalamic nucleus with concomitant increases in PPARγ exclusively within AgRP/NPY neurons. ROSI increased AgRP and NPY similarly to FD, and GW9662 prevented FD-induced increases in AgRP and NPY in both species. Neither ROSI nor GW9662 affected plasma ghrelin. Thus, we demonstrated that PPARγ activation is sufficient to trigger food hoarding/intake, increase AgRP/NPY, and possibly is necessary for FD-induced increases in feeding and AgRP/NPY. These findings provide initial evidence that FD-induced increases in AgRP/NPY may be a direct PPARγ-dependent process that controls ingestive behaviors. Copyright © 2015 the authors 0270-6474/15/354571-11$15.00/0.

  4. Effects of hypoglycaemia on neurotransmitter and hormone receptor gene expression in laser-dissected arcuate neuropeptide Y/agouti-related peptide neurones.

    PubMed

    Briski, K P; Nedungadi, T P; Koshy Cherian, A

    2010-06-01

    Arcuate neuropeptide Y (NPY)/agouti-related pepide (AgRP) neurones regulate energy homeostasis, and express the putative glucosensor, glucokinase (GCK). The present study performed multi-transcriptional profiling of these neurones to characterise NPY, AgRP and GCK gene expression during intermediate insulin-induced hypoglycaemia, and to determine whether these transcriptional responses acclimate to repeated insulin dosing. We also examined whether these neurones express insulin, glucocorticoid and oestrogen receptor gene transcripts, and whether the levels of these receptor mRNAs are modified by insulin-induced hypoglycaemia. Individual NPY-immunoreactive neurones were laser-microdissected from the caudal arcuate nucleus after single or serial dosing with neutral protamine Hagedorn insulin (NPH), and evaluated by quantitative real-time reverse transcriptase-polymerase chain reaction for the assessment of neurotransmitter and receptor gene expression. Mean NPY and AgRP mRNA in harvested NPY neurones was unchanged or augmented, respectively, by one NPH dose, although repeated NPH administration up-regulated NPY, whereas AgRP gene transcripts were down-regulated. NPH elicited divergent modifications in the ERalpha and ERbeta mRNA content of sampled neurones. ERalpha transcripts were amplified by both acute and chronic NPH-induced hypoglycaemia, whereas ERbeta gene expression was unaltered during a single bout, but suppressed during recurring hypoglycaemia. Glucocorticoid receptor (GR) mRNA levels were increased by a single insulin dose, but unaffected by serial NPH dosing. Insulin receptor-beta chain (InsRb) gene transcripts were insensitive to acute NPH-induced hypoglycaemia, but repeated NPH inhibited this gene transcript. Neither acute nor recurring hypoglycaemia modified GCK mRNA levels in caudal hypothalamic arcuate nucleus (ARH) NPY/AgRP neurones, but baseline GCK transcription was suppressed by the latter. This evidence for the habituation of hypoglycaemic

  5. Long-Term Outcome of Half-Dose Verteporfin Photodynamic Therapy for the Treatment of Central Serous Chorioretinopathy (An American Ophthalmological Society Thesis).

    PubMed

    Lai, Timothy Y Y; Wong, Raymond L M; Chan, Wai-Man

    2015-01-01

    To evaluate whether half-dose verteporfin photodynamic therapy (PDT) is better than natural history for the treatment of central serous chorioretinopathy (CSC). Retrospective review of consecutive CSC patients treated with half-dose verteporfin PDT or untreated with observation and a minimum follow-up of 36 months. The main outcome measures included mean change in visual acuity and CSC recurrence. Survival analysis was performed to compare the CSC recurrence rates between the two groups. A total of 192 eyes of 192 patients were included; 75 eyes were treated with half-dose verteporfin PDT and 117 were untreated. The mean follow-up duration was 74.1 months. At the last follow-up, the mean logMAR visual acuity was significantly better in the half-dose verteporfin PDT group compared with the untreated control group (P=.005). The mean visual improvement of the half-dose verteporfin PDT group at the last follow-up was 1.8 lines, compared with 0.0 line in the untreated control group (P<.001). Recurrence of CSC developed in 15 eyes (20%) in the half-dose verteporfin PDT group compared with 63 eyes (53.8%) in the untreated control group (P<.001). Survival analysis demonstrated that eyes treated with half-dose verteporfin PDT were significantly less likely to develop CSC recurrence compared with untreated controls (P<.001). Regression analysis showed that half-dose verteporfin PDT was the only significant factor in reducing the risk of CSC recurrence. Half-dose verteporfin PDT for the treatment of CSC resulted in significantly better visual acuity outcomes and lower recurrence rate in the long term compared with untreated controls.

  6. Long-Term Outcome of Half-Dose Verteporfin Photodynamic Therapy for the Treatment of Central Serous Chorioretinopathy (An American Ophthalmological Society Thesis)

    PubMed Central

    Lai, Timothy Y. Y.; Wong, Raymond L. M.; Chan, Wai-Man

    2015-01-01

    Purpose: To evaluate whether half-dose verteporfin photodynamic therapy (PDT) is better than natural history for the treatment of central serous chorioretinopathy (CSC). Methods: Retrospective review of consecutive CSC patients treated with half-dose verteporfin PDT or untreated with observation and a minimum follow-up of 36 months. The main outcome measures included mean change in visual acuity and CSC recurrence. Survival analysis was performed to compare the CSC recurrence rates between the two groups. Results: A total of 192 eyes of 192 patients were included; 75 eyes were treated with half-dose verteporfin PDT and 117 were untreated. The mean follow-up duration was 74.1 months. At the last follow-up, the mean logMAR visual acuity was significantly better in the half-dose verteporfin PDT group compared with the untreated control group (P=.005). The mean visual improvement of the half-dose verteporfin PDT group at the last follow-up was 1.8 lines, compared with 0.0 line in the untreated control group (P<.001). Recurrence of CSC developed in 15 eyes (20%) in the half-dose verteporfin PDT group compared with 63 eyes (53.8%) in the untreated control group (P<.001). Survival analysis demonstrated that eyes treated with half-dose verteporfin PDT were significantly less likely to develop CSC recurrence compared with untreated controls (P<.001). Regression analysis showed that half-dose verteporfin PDT was the only significant factor in reducing the risk of CSC recurrence. Conclusions: Half-dose verteporfin PDT for the treatment of CSC resulted in significantly better visual acuity outcomes and lower recurrence rate in the long term compared with untreated controls. PMID:26755855

  7. Ocular Perfusion Pressure vs Estimated Trans-Lamina Cribrosa Pressure Difference in Glaucoma: The Central India Eye and Medical Study (An American Ophthalmological Society Thesis).

    PubMed

    Jonas, Jost B; Wang, Ningli; Nangia, Vinay

    2015-01-01

    To test the hypothesis that taking translamina pressure difference into consideration changes associations between ocular perfusion pressure and glaucomatous optic neuropathy. The population-based Central India Eye and Medical Study included 4711 subjects. Ocular perfusion pressure was calculated as follows: ⅔ [diastolic blood pressure + ⅓ × (systolic blood pressure - diastolic blood pressure)] - IOP. Cerebrospinal fluid pressure (mm Hg) was estimated as follows: 0.44 body mass index (kg/m(2)) + 0.16 diastolic blood pressure (mm Hg) - 0.18 × age (years) - 1.91. Translamina pressure difference was IOP minus cerebrospinal fluid pressure. In multivariate analysis, higher open-angle glaucoma prevalence was associaed with higher IOP (P<.001; odds ratio [OR], 1.19; 95% CI, 1.15, 1.24) or with higher translamina pressure difference (P<.001; OR, 1.15; 95% CI, 1.10, 1.19), but not with ocular perfusion pressure (P<.37). A smaller neuroretinal rim area was correlated with higher IOP (P<.001; standardized coefficient beta -0.09) or larger translamina pressure difference (P<.001; β -0.10), but not with ocular perfusion pressure (P=.26). Greater prevalence of angle-closure glaucoma was associated with higher IOP (P<.001; OR, 1.22; 95% CI, 1.15, 1.28) or higher translamina pressure difference (P<.001; OR, 1.19; 95% CI, 1.13, 1.25) or lower ocular perfusion pressure (P<.04; OR, 0.95; 95% CI, 0.90, 0.996). Correlation coefficients were highest for the association with IOP and lowest for ocular perfusion pressure. A smaller rim area was correlated with higher IOP (P<.001; beta -0.08) and higher translamina pressure difference (P<.001; beta -0.08); rim area and ocular perfusion pressure were not significantly associated (P=.25). The present study provides information on the relationship of translamina pressure difference to the development of optic nerve damage in what is presently called glaucoma. It does not provide support of the idea that ocular perfusion pressure plays a

  8. Native American Architecture.

    ERIC Educational Resources Information Center

    Nabokov, Peter; Easton, Robert

    This book presents building traditions of the major Indian tribes in nine regions of the North American continent, from the huge, plankhouse villages of the Northwest Coast, to the moundbuilder towns and temples of the Southeast, to the Navajo hogans and adobe pueblos of the Southwest. Indian buildings are a central element of Indian culture, the…

  9. Arab American Voices.

    ERIC Educational Resources Information Center

    Hall, Loretta

    Through speeches, newspaper accounts, poems, memoirs, interviews, and other materials by and about Arab Americans, this collection explores issues central to what it means to be of Arab descent in the United States today. Each of the entries is accompanied by an introduction, biographical and historical information, a glossary for the selection,…

  10. Native American Architecture.

    ERIC Educational Resources Information Center

    Nabokov, Peter; Easton, Robert

    This book presents building traditions of the major Indian tribes in nine regions of the North American continent, from the huge, plankhouse villages of the Northwest Coast, to the moundbuilder towns and temples of the Southeast, to the Navajo hogans and adobe pueblos of the Southwest. Indian buildings are a central element of Indian culture, the…

  11. Arab American Voices.

    ERIC Educational Resources Information Center

    Hall, Loretta

    Through speeches, newspaper accounts, poems, memoirs, interviews, and other materials by and about Arab Americans, this collection explores issues central to what it means to be of Arab descent in the United States today. Each of the entries is accompanied by an introduction, biographical and historical information, a glossary for the selection,…

  12. American Indian Task Force Report.

    ERIC Educational Resources Information Center

    Mackey, John E., Ed.

    Assuming that the client is central to any service program, the American Indian Task Force examined a national sample of "grass roots" social service organizations and/or individuals and schools of social work to determine the capability of providing relevant social work education to American Indians. Accordingly, the highest priorities…

  13. American Women and American Studies.

    ERIC Educational Resources Information Center

    Chmaj, Betty E.

    The American Studies Association (ASA) is an interprofessional group, representing a cross-section of persons from American literature, American history, the social sciences, philosophy, archeology, Black Studies, Urban Studies, American Studies, and others. This document by the ASA Commission on the Status of Women includes: (1) a report of the…

  14. External Review Teams Training in Central America

    ERIC Educational Resources Information Center

    Silva-Trivino, Moises; Ramirez-Gatica, Soledad

    2004-01-01

    Many Latin American countries have started actions to promote a higher education quality assurance system. Central America appears as a regional effort that includes universities from all seven countries under the initiative of Central American University Higher Council (CSUCA). After focusing in quality management and self-study processes, CSUCA…

  15. External Review Teams Training in Central America

    ERIC Educational Resources Information Center

    Silva-Trivino; Moises; Ramirez-Gatica, Soledad

    2004-01-01

    Many Latin American countries have started actions to promote a higher education quality assurance system. Central America appears as a regional effort that includes universities from all seven countries under the initiative of Central American University Higher Council (CSUCA). After focusing in quality management and self-study processes, CSUCA…

  16. Evaluation of United States Strategy In Central America

    DTIC Science & Technology

    1989-03-03

    General Treaty for Central American Integration, signed by the five coun- tries in 1960, led to the establishment of a Central American Common Market ...The Bipartisan Commission on Central America de- scribed this period as follows: The common market inspired a surge of energy and optimism throughout...regional tensions and unrest collapsing the Central American Common Market and causing capital flight; bad government policies resulting in dis- incentives

  17. Guatemala, a Troubled Central American Country.

    DTIC Science & Technology

    1986-04-01

    history. It has its beginning in an aborted military coup in November, 1960, by some army officers. The leader of the coup was Colonel Rafael Sessen...Pereira, and his closest associates were 19 year-old Second Lieutenant Luis Turcios Lima and 22 year-old Lieutenant Mareo Antonio Yon Sosa . However, in...only 4 days the coup failed, forcing leaders to flee to Honduras (1:62-65; 2:8). In 1961, Turcios Lima and Yon Sosa returned to Guatemala. They then

  18. The He-CO 2 isotope and relative abundance characteristics of geothermal fluids in El Salvador and Honduras: New constraints on volatile mass balance of the Central American Volcanic Arc

    NASA Astrophysics Data System (ADS)

    de Leeuw, G. A. M.; Hilton, D. R.; Fischer, T. P.; Walker, J. A.

    2007-06-01

    We report helium and carbon isotope and relative abundance data of fumaroles, hot springs, water springs, mud-pots and geothermal wells from El Salvador and Honduras to investigate both along and across-arc controls on the release of CO 2 from the subducted slab. El Salvador localities show typical volcanic front volcanic gas signatures, with 3He/ 4He ratios of 5.2-7.6 RA, δ13C values of - 3.6‰ to - 1.3‰ and CO 2/ 3He ratios of 8-25 × 10 9. In Honduras, we find similar values only for volatiles collected in the Sula Graben region located ˜ 200 km behind the volcanic front. All other areas in Honduras show significantly lower 3He/ 4He ratios (0.7-3.5 RA), lower δ13C values (< - 7.3‰) and more variable CO 2/ 3He ratios (6.2 × 10 7-2.0 × 10 11): characteristics consistent with degassing-induced fractionation of CO 2 and He and/or interaction with crustal rocks. The provenance of CO 2 released along the volcanic front is dominated by subducted marine carbonates (L = 76 ± 4%) and organic sediments (S = 14 ± 3%), with the mantle wedge (M) contributing 10 ± 3% to the total carbon flux. The L/S ratio of the El Salvador volatiles (average = 5.6) is comparable to volcanic front localities in Costa Rica and Nicaragua [A.M. Shaw, D.R. Hilton, T.P. Fischer, L.A. Walker, G.E. Alvarado, Contrasting He-C relationships in Nicaragua and Costa Rica: insights into C cycling through subduction zones. Earth Planet. Sci. Lett. 214 (2003) 499-513] but is approximately one-half the input value of sediments at the trench (L. Li, G.E. Bebout, Carbon and nitrogen geochemistry of sediments in the Central American convergent margin: Insights regarding subduction input fluxes, diagenesis, and paleoproductivity, J. Geophys. Res. 110 (2005), doi: 10.1029/2004JB003276). We use the L/S ratio of El Salvador geothermal fluids, together with estimates of the CO 2 output flux from the arc, to constrain the amount and composition of subducted sediments involved in the supply of CO 2 to the

  19. The prediction role of indexes of circulating adipokines for common anthropometric and nutritional characteristics of obesity in the obese Central European population.

    PubMed

    Bienertová-Vašků, Julie; Novák, Jan; Zlámal, Filip; Forejt, Martin; Havlenová, Soňa; Jackowská, Aneta; Tomandl, Josef; Tomandlová, Marie; Šplíchal, Zbyněk; Vašků, Anna

    2014-04-01

    This study was designed to investigate the relationship between 8 selected adipokines (leptin, leptin receptor, adiponectin, agouti-related peptide, omentin, visfatin, adipsin and resistin), dietary composition and anthropometric parameters found in the Central European obese population. A total of 65 unrelated obese Central European Caucasian individuals were recruited for the study. Phenotypic